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Algorithms/Hill Climbing

Hill climbing is a technique for certain classes of optimization problems. The idea is to start with a sub-optimal solution to a problem (i.e., start at the base of a hill) and then repeatedly improve the solution (walk up the hill) until some condition is maximized (the top of the hill is reached).

One of the most popular hill-climbing problems is the network flow problem. Although network flow may sound somewhat specific it is important because it has high expressive power: for example, many algorithmic problems encountered in practice can actually be considered special cases of network flow. After covering a simple example of the hill-climbing approach for a numerical problem we cover network flow and then present examples of applications of network flow.

Newton's Root Finding Method
Newton's Root Finding Method is a three-centuries-old algorithm for finding numerical approximations to roots of a function (that is a point $$x$$ where the function $$f(x)$$ becomes zero), starting from an initial guess. You need to know the function $$f(x)\,$$ and its first derivative $$f'(x)\,$$ for this algorithm. The idea is the following: In the vicinity of the initial guess $$x_0$$ we can form the Taylor expansion of the function

 * $$f(x)=f(x_0+\epsilon)\,$$$$\approx f(x_0)+\epsilon f'(x_0)$$$$+\frac{\epsilon^2}{2} f''(x_0)+...$$

which gives a good approximation to the function near $$x_0$$. Taking only the first two terms on the right hand side, setting them equal to zero, and solving for $$\epsilon$$, we obtain

 * $$\epsilon=-\frac{f(x_0)}{f'(x_0)}$$

which we can use to construct a better solution

 * $$x_1=x_0+\epsilon=x_0-\frac{f(x_0)}{f'(x_0)}.$$

This new solution can be the starting point for applying the same procedure again. Thus, in general a better approximation can be constructed by repeatedly applying

 * $$x_{n+1}=x_n-\frac{f(x_n)}{f'(x_n)}.$$

As shown in the illustration, this is nothing else but the construction of the zero from the tangent at the initial guessing point. In general, Newton's root finding method converges quadratically, except when the first derivative of the solution $$f'(x)=0\,$$ vanishes at the root.

Coming back to the "Hill climbing" analogy, we could apply Newton's root finding method not to the function $$f(x)\,$$, but to its first derivative $$f'(x)\,$$, that is look for $$x$$ such that $$f'(x)=0\,$$. This would give the extremal positions of the function, its maxima and minima. Starting Newton's method close enough to a maximum this way, we climb the hill.

Example application of Newton's method
The net present value function is a function of time, an interest rate, and a series of cash flows. A related function is Internal Rate of Return. The formula for each period is (CFi x (1+ i/100) t, and this will give a polynomial function which is the total cash flow, and equals zero when the interest rate equals the IRR. In using Newton's method, x is the interest rate, and y is the total cash flow, and the method will use the derivative function of the polynomial to find the slope of the graph at a given interest rate (x-value), which will give the xn+1 , or a better interest rate to try in the next iteration to find the target x where y ( the total returns) is zero.

Instead of regarding continuous functions, the hill-climbing method can also be applied to discrete networks.

Network Flow
Suppose you have a directed graph (possibly with cycles) with one vertex labeled as the source and another vertex labeled as the destination or the "sink". The source vertex only has edges coming out of it, with no edges going into it. Similarly, the destination vertex only has edges going into it, with no edges coming out of it. We can assume that the graph is fully connected with no dead-ends; i.e., for every vertex (except the source and the sink), there is at least one edge going into the vertex and one edge going out of it.

We assign a "capacity" to each edge, and initially we'll consider only integral-valued capacities. The following graph meets our requirements, where "s" is the source and "t" is the destination:

We'd like now to imagine that we have some series of inputs arriving at the source that we want to carry on the edges over to the sink. The number of units we can send on an edge at a time must be less than or equal to the edge's capacity. You can think of the vertices as cities and the edges as roads between the cities and we want to send as many cars from the source city to the destination city as possible. The constraint is that we cannot send more cars down a road than its capacity can handle.

The goal of network flow is to send as much traffic from $$s$$ to $$t$$ as each street can bear.

To organize the traffic routes, we can build a list of different paths from city $$s$$ to city $$t$$. Each path has a carrying capacity equal to the smallest capacity value for any edge on the path; for example, consider the following path $$p$$:

Even though the final edge of $$p$$ has a capacity of 8, that edge only has one car traveling on it because the edge before it only has a capacity of 1 (thus, that edge is at full capacity). After using this path, we can compute the residual graph by subtracting 1 from the capacity of each edge:

(We subtracted 1 from the capacity of each edge in $$p$$ because 1 was the carrying capacity of $$p$$.) We can say that path $$p$$ has a flow of 1. Formally, a flow is an assignment $$f(e)$$ of values to the set of edges in the graph $$G = (V, E)$$ such that:
 * 1. $$\forall e\in E: f(e)\in\R$$
 * 2. $$\forall (u,v)\in E: f((u,v)) = -f((v,u))$$
 * 3. $$\forall u\in V, u\ne s,t: \sum_{v\in V}f(u,v) = 0$$
 * 4. $$\forall e\in E: f(e)\le c(e)$$

Where $$s$$ is the source node and $$t$$ is the sink node, and $$c(e)\ge 0$$ is the capacity of edge $$e$$. We define the value of a flow $$f$$ to be:
 * $$\textrm{Value}(f) = \sum_{v\in V} f((s, v))$$

The goal of network flow is to find an $$f$$ such that $$\textrm{Value}(f)$$ is maximal. To be maximal means that there is no other flow assignment that obeys the constraints 1-4 that would have a higher value. The traffic example can describe what the four flow constraints mean:

 * 1) $$\forall e\in E: f(e)\in\R$$. This rule simply defines a flow to be a function from edges in the graph to real numbers. The function is defined for every edge in the graph. You could also consider the "function" to simply be a mapping: Every edge can be an index into an array and the value of the array at an edge is the value of the flow function at that edge.
 * 2) $$\forall (u,v)\in E: f((u,v)) = -f((v,u))$$. This rule says that if there is some traffic flowing from node u to node v then there should be considered negative that amount flowing from v to u. For example, if two cars are flowing from city u to city v, then negative two cars are going in the other direction. Similarly, if three cars are going from city u to city v and two cars are going city v to city u then the net effect is the same as if one car was going from city u to city v and no cars are going from city v to city u.
 * 3) $$\forall u\in V, u\ne s,t: \sum_{v\in V}f(u,v) = 0$$. This rule says that the net flow (except for the source and the destination) should be neutral. That is, you won't ever have more cars going into a city than you would have coming out of the city. New cars can only come from the source, and cars can only be stored in the destination. Similarly, whatever flows out of s must eventually flow into t. Note that if a city has three cars coming into it, it could send two cars to one city and the remaining car to a different city. Also, a city might have cars coming into it from multiple sources (although all are ultimately from city s).
 * 4) $$\forall e\in E: f(e)\le c(e)$$.

The Ford-Fulkerson Algorithm
The following algorithm computes the maximal flow for a given graph with non-negative capacities. What the algorithm does can be easy to understand, but it's non-trivial to show that it terminates and provides an optimal solution.

function net-flow(graph (V, E), node s, node t, cost c): flow initialize f(e) := 0 for all e in E loop while not done for all e in E:                        // compute residual capacities let cf(e) := c(e) - f(e) repeat let Gf := (V, {e : e in E and cf(e) > 0}) find a path p from s to t in Gf        // e.g., use depth first search if no path p exists: signal done let path-capacities := map(p, cf)      // a path is a set of edges let m := min-val-of(path-capacities)   // smallest residual capacity of p for all (u, v) in p:                   // maintain flow constraints f((u, v)) := f((u, v)) + m f((v, u)) := f((v, u)) - m repeat repeat end

The Ford-Fulkerson algorithm uses repeated calls to Breadth-First Search ( use a queue to schedule the children of a node to become the current node). Breadth-First Search increments the length of each path +1 so that the first path to get to the destination, the shortest path, will be the first off the queue. This is in contrast with using a Stack, which is Depth-First Search, and will come up with *any* path to the target, with the "descendants" of current node examined, but not necessarily the shortest.
 * In one search, a path from source to target is found. All nodes are made unmarked at the beginning of a new search. Seen nodes are "marked", and not searched again if encountered again. Eventually, all reachable nodes will have been scheduled on the queue , and no more unmarked nodes can be reached off the last the node on the queue.
 * During the search, nodes scheduled have the finding "edge" (consisting of the current node, the found node, a current flow, and a total capacity in the direction first to second node), recorded.
 * This allows finding a reverse path from the target node once reached, to the start node. Once a path is found, the edges are examined to find the edge with the minimum remaining capacity, and this becomes the flow that will result along this path, and this quantity is removed from the remaining capacity of each edge along the path. At the "bottleneck" edge with the minimum remaining capacity, no more flow will be possible, in the forward direction, but still possible in the backward direction.
 * This process of BFS for a path to the target node, filling up the path to the bottleneck edge's residual capacity, is repeated, until BFS cannot find a path to the target node ( the node is not reached because all sequences of edges leading to the target have had their bottleneck edges filled). Hence memory of the side effects of previous paths found, is recorded in the flows of the edges, and affect the results of future searches.
 * An important property of maximal flow is that flow can occur in the backward direction of an edge, and the residual capacity in the backward direction is the current flow in the foward direction. Normally, the residual capacity in the forward direction of an edge is the initial capacity less forward flow. Intuitively, this allows more options for maximizing flow as earlier augmenting paths block off shorter paths.
 * On termination, the algorithm will retain the marked and unmarked states of the results of the last BFS.
 * the minimum cut state is the two sets of marked and unmarked nodes formed from the last unsuccessful BFS starting from the start node, and not marking the target the node. The start node belongs to one side of the cut, and the target node belongs to the other. Arbitrarily, being "in Cut" means being on the start side, or being a marked node. Recall how are a node comes to be marked, given an edge with a flow and a residual capacity.

Example application of Ford-Fulkerson maximum flow/ minimum cut
An example of application of Ford-Fulkerson is in baseball season elimination. The question is whether the team can possibly win the whole season by exceeding some combination of wins of the other teams.

The idea is that a flow graph is set up with teams not being able to exceed the number of total wins which a target team can maximally win for the entire season. There are game nodes whose edges represent the number of remaining matches between two teams, and each game node outflows to two team nodes, via edges that will not limit forward flow; team nodes receive edges from all games they participate. Then outflow edges with win limiting capacity flow to the virtual target node. In a maximal flow state where the target node's total wins will exceed some combination of wins of the other teams, the penultimate depth-first search will cutoff the start node from the rest of the graph, because no flow will be possible to any of the game nodes, as a result of the penultimate depth-first search (recall what happens to the flow, in the second part of the algorithm after finding the path). This is because in seeking the maximal flow of each path, the game edges' capacities will be maximally drained by the win-limit edges further along the path, and any residual game capacity means there are more games to be played that will make at least one team overtake the target teams' maximal wins. If a team node is in the minimum cut, then there is an edge with residual capacity leading to the team, which means what, given the previous statements? What do the set of teams found in a minimum cut represent ( hint: consider the game node edge) ?

Example Maximum bipartite matching ( intern matching )
This matching problem doesn't include preference weightings. A set of companies offers jobs which are made into one big set, and interns apply to companies for specific jobs. The applications are edges with a weight of 1. To convert the bipartite matching problem to a maximum flow problem, virtual vertexes s and t are created, which have weighted 1 edges from s to all interns, and from all jobs to t. Then the Ford-Fulkerson algorithm is used to sequentially saturate 1 capacity edges from the graph, by augmenting found paths. It may happen that a intermediate state is reached where left over interns and jobs are unmatched, but backtracking along reverse edges which have residual capacity = forward flow = 1, along longer paths that occur later during breadth-first search, will negate previous suboptimal augmenting paths, and provide further search options for matching, and will terminate only when maximal flow or maximum matching is reached.

title: Algorithms/Hill Climbing


text: Algorithms/Ada Implementation

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Algorithms/Ada Implementation


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Template:Algorithms/TOC

Top, Chapters: 1, 2, 3, 4, 5, 6, 7, 8, 9, A

title: Template:Algorithms/TOC


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Talk:Physics Study Guide/Thermodynamics

Thermodynamic/s-is the study of heat and other forms of energy. Consist of three Laws namely: [First Law of Thermodynamics][Second Law of Thermodynamics][Third Law or Zeroth Law].

The study of thermodynamic is pioneered by James Prescott Joule in which he stated in mathematical equation the relationship between Work and Heat:

A question...
I, at least, call the ice point 'freezing point', and the steam point 'boiling point'. Is this significant? Is you definition more precise/accurate terminology, or is it a language difference? Ta, --81.156.221.98 21:49, 8 Jan 2005 (UTC)

title: Talk:Physics Study Guide/Thermodynamics


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Soil Science

Soil Science
Soil Science encompasses many aspects of soils study such as the disciplines of soil physics, soil chemistry, soil classification, soil microbiology, etc. One of these studies is pedology. Pedology is the study of soils in a three dimensional context in their natural setting across the landscape in terms of origins, morphology (forms), classifications, characteristics or attributes, profile or cross-section, surface and internal water relations, geology, plant ecology, etc. and interpretations for use and management.

Most soils develop from weathered mineral geologic materials and usually include some organic materials in their upper part. This is called the O horizon, and it is composed of organic material, generally not considered topsoil, but leaf litter and muck. The rock that the mineral part of the soil originates from is called the parent material. Through the further influence of the soil-forming processes of additions, removals, transfers and transformations the nature of the parent materials are altered to the extent that they become soils. The soil-forming processes are controlled by the soil forming factors of parent material, climate, living organisms, relief, and time. Thus the similarity or contrast of soils from place to place reflects the similarity or contrasts of the soil-forming processes and factors.

The primary convention for naming soils is to select a named geographic feature in the vicinity where the soil was first recognized and identified as a new soil, e.g: the Dunkirk soil series for the village of Dunkirk near Lake Erie, NY. All soils found to have closely similar attributes are classified as Dunkirk wherever they are found. That distribution can be more localized or it can be somewhat more extensive.

The description of the soil usually identifies attributes such as pH (degree of alkalinity or acidity), maturity (stage of pedogenic development), texture, consistence, color, gravel content and type, drainage class, and other soil features.

The United States and other nations have soil maps that show the soils in relation to one another as they occur across the landscape. On these maps each soil is characteristically related to a unique landscape position. Thus, the pattern of distribution and the location and extent of the soil type can be comprehended. Soil maps are a prime requisite for many users who need site information to make informed decisions on many aspects of use and management. Comparison of soil resources and their respective suitabilities and/or limitations can also be used to evaluate alternate sites for intended uses.

In the United States the Cooperative Soil Survey has more than a hundred year history. The various surveys were published with text and maps as soft covered books. Now they are published through the internet Web Soil Survey at: http://websoilsurvey.nrcs.usda.gov/app/

Soil Equations
The Bulk Density of a soil is its dry mass divided by the total original volume of the soil. The porosity of a soil is the volume of its pores divided by the total volume of the soil. The particle density of a soil is the mass of its solids divided by the volume of its solids.

Soil Water
Field Capacity When a soil has drained freely for several days after rain or irrigation, the water content is the field capacity of the soil.

The field capacity is a measure of the soils ability to store water. A sandy soil freely drains and the field capacity is low. A clayey soil holds water and has a high field capacity. A clayey soil can store more water than a sandy soil.

Soil structure effects the field capacity. A structureless clay with no large pores has a very high field capacity. A well structured clay with large pores will drain freely and has a lower field capacity.

Organic matter can absorb water and increases field capacity.

The field capacity of a soil is mainly determined by the pore size distribution. Small pores hold water by capillary forces. Large pores freely drain and do not hold water at field capacity.

Wilting Point When a soil is dry and plants suffer from permanent wilting because they are unable to absorb water, the moisture content is the wilting point of the soil.

When the moisture content is above the wilting point, plants can absorb water from the soil. Below the wilting point, water is tightly adsorbed to clay particles and is unavailable to plants.

Sandy soils have very low wilting points while clays have high wilting points. A clay contains a significant amount of water unavailable to plants.

Available Water The amount of water stored by a soil that can be absorbed by a plant is the available water and is equal to the water held at the field capacity minus the wilting point.

The available water is the water stored by a soil and is useful to plants. Texture, structure and organic matter have an effect on the available water. Clayey soils generally have a higher available water than sandy soils. A well developed structure can increase the available water. Organic matter absorbs water and increases the available water.

The available water stored in a soil is often measured as mm of water. Farmers prefer to sow a crop when there is sufficient water stored in the soil to ensure good plant growth. If the amount of stored water is low, the farmer needs to pray for rain. The amount of water available to plants also depends on the depth of the plant roots.

Soluble salts in soils reduces the availability of water to plants. Salt increases the osmotic pressure of water. High salt content in soils will kill plants.

Soil Water Infiltration
It is well known that urban development increases flooding. In urban areas the coefficient of runoff increases, and the time of concentration decreases. The coefficient of runoff in undisturbed areas can be as low as 0.1, while in inner city suburbs, coefficient of runoff can be as high as 0.9.

During rainfall a high value of coefficient of runoff occurs when most rainfall flows over the land and little water is absorbed by soils. When all the rain flows over the surface and no rain infiltrates into the soil the coefficient of runoff equals 1. If a high volume of water enters the soil the coefficient of runoff is small and approaches 0.

The main source of fresh water is rainfall runoff, which is widely used to meet human needs. Runoff is a vital part of long term water supply and renews water resources be they rivers, lakes or reservoirs. Plants need water to grow and evapotranspiration by plants returns water from the soil into the atmosphere.

Rate of water infiltration The rate at which water enters the soil during rain or irrigation is the infiltration rate.

When rain first enters a dry soil, infiltration is rapid, then decreases as it continues to rain. During the early stages of rainfall, water fills up the dry pores. When the pores are filled with water and the soil is saturated, infiltration slows down until it reaches a constant value.

When it has stopped raining, the surface soil will be saturated with water. Free water in a saturated soil will drain under gravity. After about 2 3 days, free water will have percolated downwards and the soil moisture will reach an equilibrium. When the free water has drained downwards, the moisture is at 'field capacity'.

At field capacity, soil water is held in the soil by several forces. The major part of the water is held by capillary forces. Some water is adsorbed onto the surfaces of soil particles, especially clay particles and organic matter.

Capillary water is the main supply of water to plants. Capillary water may be removed by transpiration by plants and evaporation. If the top soil is dry and the underlying soil is wet, water can move upwards by capillary action.

Above the water table there is a capillary fringe. Water moves upwards from the water table by Capillary forces. In some. soils, especially clays which contain many fine pores, the capillary fringe can be up to one metre above the water table.

During rain the infiltration rate slows down as the soil becomes wet.

Infiltration rates vary greatly between different soils, and typical values are, 100mm/hour during the first hour of rain, decreasing to 10mm/hr after six hours of rain.

Peds are small aggregates (1 2mrn ) found in many soils. Pedal soils have a good structure and water flows easily through these soils. Apedal soils have a poor structure and apedal clayey soils have poor water infiltration. Sandy soils generally have high water infiltration and clayey soils have low infiltration rates.

If the intensity of rainfall is constant, and infiltration decreases at a typical rate, there is no runoff during the early stages of the rain event. When the infiltration rate is slower than the rainfall intensity, runoff is expected to occur.

Infiltration rate is controlled by the soil layer which has the lowest hydraulic conductivity. Often the top soil is a loam and has a high hydraulic conductivity. A clayey subsoil with a low hydraulic conductivity will act as a throttle, slowing down the final infiltration rate.

In the field, infiltration can be directly measured using a ring infiltrometer. A circular tube is forced into the soil, which is ponded with water. At specific time intervals, rate of water flow into the soil is recorded. To reduce variability, the rings need to be fairly large, generally rings should be bigger than 112 meter in diameter. Often a double ring infiltrometer is used to reduce errors from lateral water movement. Variability in these experiments is often high, so it is advisable to carry out a number of replicates.

It is common in many soils for the infiltration rate to decrease by a factor of ten, after six hours of rain. A steady state equilibrium is usually reached before six hours. Infiltration rates vary greatly between different soils, and typical values are, 10Omm/hour during the first hour of rain, decreasing to 1 mm/hr after six hours of rain.

title: Soil Science


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Wi-Fi/Cantenna

About Cantennas
A cantenna is a directional waveguide antenna for long-range WiFi (cf. Hi-fi) which can be used to increase the range (or snoop) on a wireless network. Originally employing a Pringle's® Potato Chip can, a cantenna can be constructed quickly, easily, and inexpensively out of readily obtained materials. It requires four nuts, a short length of medium gauge wire, a tin can roughly 9 cm (3.66 inches) in diameter, the longer the better, and an N-Female chassis mount collector, which can be purchased at any electronic supply store. The original design employed a Pringle's can, but an optimal design will use a longer tin can. Instructions for constructing and connecting a cantenna can be found at Turnpoint.net.

While cantennas are useful for extending a local-area network (LAN), the tiny design makes them ideal for mobile applications, such as wardriving. Its design is so simple and ubiquitous that it is often the first antenna that WiFi experimenters learn to build. Even the Secret Service has taken an interest in the can antenna.

How to make a Cantenna
You'll need
 * An N-male chassis mount connector
 * One side is N-female for connecting the cable from your wireless equipment, and the other side has a small brass stub for soldering on wire. These can be found at electronics stores internet suppliers (see the list below under "Connect your antenna..." If you shop around, you should be able to find these for $3-$5.

 * Four small nuts and bolts

 * A bit of thick wire
 * A can
 * The diameter of the can should be around 8.3 cm. The cappuccino cans available at Lidl supermarkets are very close to the ideal diameter..
 * Reading this guide the better size of the can it's about 92.796mm

title: Wi-Fi/Cantenna


text:
User:IBB~enwikibooks

 * [mailto:stdnms@gmail.com Email me!]
 * My contributions in the PHP book:
 * The "functions" section
 * The "Commenting and style" section
 * "count" + "Other Keys" in the arrays section
 * Initial "PHP with mySQL" section(needs a lot of work).
 * To anyone who had to clear my spelling mistakes after me, I apologize, I'm not a native English speaker.

title: User:IBB~enwikibooks


text:
User:Anul

My Home Page

title: User:Anul


text:
User:Dupuy

@alex

title: User:Dupuy


text: Template:Non-free screenshot

title: Template:Non-free screenshot


text: Template:Prognav

title: Template:Prognav


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Chinese (Mandarin)/Nations of the World

Here's a list of some nations and regions, with their names in Chinese. Note that the country's name can also be used as an adjective. For example, 日本货 (rìběn huò) means "Japanese goods," and is derived from 日本 (rìběn; Japan) and 货 (huò; goods). As an aside, China imports a good number of products from Japan. Between 2001 and 2007, it was the greatest exporter to China, beating the European Union, South Korea, and Taiwan. You could also say 日本椅子 (rìběn yǐzi; Japanese chair), 日本食品 (rìběn shípǐn; Japanese food products), and 日本动画片 (rìběn dònghuà piàn; Japanese cartoons). Terms like these can be shortened, for example, 日货 means the same thing. You can see 日 is an adjective which means "pertaining to Japan," i.e., "Japanese." Another way to describe its function is that it acts like a "root," much like in English. Headlines are often abbreviated this way. For example, 中俄合作 (zhōng é hézuò) can mean "China and Russia cooperate" or "Sino-Russian cooperation." In common conversation, however, excessive abbreviation is undesirable, because it often leads to ambiguity.

 * References

title: Chinese (Mandarin)/Nations of the World


text:
User:Ragnarokker

Half-web master of the Internet Monolith known as Bill and Lars Online

title: User:Ragnarokker


text:
Talk:Engineering Thermodynamics/First Law

I don't understand this!

This is amazing, i just can't beleive it!


text:
User:EuropracBHIT~enwikibooks

Hello, everyone! Just a clear-up here. No, I'm not Polish, as you might see from my history page. This below is an answer to a query I had about Polish food and cuisine in celebrations last year (2004) as you will see.

1. Boże Narodzenie (God's Birth) 2. On Xmas Eve, we don't eat any meat, so traditional dishes might be:fish soup, beetroot soup with ravioli (pierogi) fried fish, fish (carp in jelly) sourkraut with mashrooms (served hot) herrings in sour cream later cakes, like ginger cakes, cheese cakes, poppyseed cake But each region in Poland has different dihes 3.On other holidays no special dishes are served

title: User:EuropracBHIT~enwikibooks


text:
Statistics/Testing Data/Purpose

Purpose of Statistical test
In general, the purpose of statistical tests is to determine whether some hypothesis is extremely unlikely given observed data.

There are two common philosophical approaches to such tests, significance testing (due to Fisher) and hypothesis testing (due to Neyman and Pearson).

Significance testing aims to quantify evidence against a particular hypothesis being true. We can think of it as testing to guide research. We believe a certain statement may be true and want to work out whether it is worth investing time investigating it. Therefore, we look at the opposite of this statement. If it is quite likely then the further study would seem to not make sense. However, if it is extremely unlikely then further study would make sense.

A concrete example of this might be in drug testing. We have a number of drugs that we want to test and only limited time, so we look at the hypothesis that an individual drug has no positive effect whatsoever and only look further if this is unlikely.

Hypothesis testing rather looks at the evidence for a particular hypothesis being true. We can think of this as a guide to making a decision. We need to make a decision soon and suspect that a given statement is true. Thus we see how unlikely we are to be wrong, and if we are sufficiently unlikely to be wrong we can assume that this statement is true. Often this decision is final and cannot be changed.

Statisticians often overlook these differences and incorrectly treat the terms "significance test" and "hypothesis test" as though they are interchangeable.

A data analyst frequently wants to know whether there is a difference between two sets of data, and whether that difference is likely to occur due to random fluctuations, or is instead unusual enough that random fluctuations rarely cause such differences.

In particular, frequently we wish to know something about the average (or mean), or about the variability (as measured by variance or standard deviation).

Statistical tests are carried out by first making some assumption, called the Null Hypothesis, and then determining whether the data observed is unlikely to occur given that assumption. If the probability of seeing the observed data is small enough under the assumed the Null Hypothesis, then the Null Hypothesis is rejected.

A simple example might help. We wish to determine if men and women are the same height on average. We select and measure 20 women and 20 men. We assume the Null Hypothesis that there is no difference between the average value of heights for men vs. women. We can then test using the t-test to determine whether our sample of 40 heights would be unlikely to occur given this assumption. The basic idea is to assume heights are normally distributed and to assume that the means and standard deviations are the same for women and for men. Then we calculate the average of our 20 men, and of our 20 women, we also calculate the sample standard deviation for each. Then using the t-test of two means with 40-2 = 38 degrees of freedom we can determine whether the difference in heights between the sample of men and the sample of women is sufficiently large to make it unlikely that they both came from the same normal population.

title: Statistics/Testing Data/Purpose


text:
SNFO Flight Planning/Philosophy of this project

Purpose of this Wikibook
Every year, a group of instructors gathers to incorporate errata, changes, and revisions to each and every Flight Training Instruction (FTI). This process typically involves many hours of painful meetings where every change—from major procedural modification to typographical correction—undergoes intense scrutiny. Without fail, as soon as the updated version arrives from the printer, people begin to notice mistakes.

Why does this occur? Despite the best intentions and vast collective experience of those charged with revising the FTI, they are but a small subset of its users, and can't possibly keep track of and correct every error to everyone's satisfaction. Even if every instructor or student who thought of a correction or suggestion while reading the FTI sent that input in to the committee, there would still be items overlooked or, at the very best, phrased ineffectually.

By locating this document in a venue where anyone has the power to edit, revise, clarify, and make corrections to it, we hope to capitalize on the collective knowledge and intelligence not only of every instructor involved in the program, but also that of the students, as well as military aviators serving in other training and operational commands, and even civilians who may bring fresh insight to what has been, until now, a largely closed instructional guide.

What this document is not
First and foremost, it should be emphasized that this version of the Flight Planning FTI is not the official source for anything! Since it may be modified, in any way, by any person, and at any time, it should always be regarded as gouge. It is, of course, the goal of this project to facilitate a continuously evolving improvement to every printed version, and in that sense, it should usually be a better reference. However, in any conflict between this Wikibook and the printed version, the published FTI and its official errata shall be considered authoritative.

In addition, it's important for those not directly associated with this training curriculum to remember that this document is not necessarily, nor is it intended to be, applicable to flight operations in general. In particular, although military aviation is subject to many of the same regulations as civil aviation, there are also many instances where service or local directives take precedence and may diverge from FAR Part 91.

Similarly, while we also train U.S. Air Force Student Navigators, as well as officers from several allied nations, all of the flight operations conducted in this program fall under U.S. Navy flight regulations. Please try to remember that the ultimate audience of this text is Primary Student NFOs/Navigators, and avoid cluttering it with material that, although it may apply to certain subsets of them in the future, is not applicable to the environment at hand. When in doubt, check to make sure any additional material directly supports the terminal and enabling objectives of the course.

Finally, there may be instances when this publication is more restrictive than any governing regulation. Again, because we instruct students in a relatively early stage of flight training, it is often necessary to provide more direction than is actually required by the rules under which Fleet aviators operate. Changes modifying these procedures on the grounds that they are not specified by governing directives should be made cautiously.

How to contribute
Everyone who reads these pages is now part of the group of people described above, charged with making corrections and improvements to this FTI. The difference is, you don't have to sit through hours of painful meetings or have a grand plan for overhauling the course. That's the advantage of the Wiki philosophy. It doesn't matter if you're a student in the Flight Planning class right now—you can still provide valuable input. We're eager to have your assistance, but before you get started, please browse through the help pages to get a feel for what a Wikibook is all about and how to contribute.

There are several ways in which you can help make this coursebook better:
 * Fixing typos or inconsistent formatting – even without any particular knowledge of the subject matter, just about everyone is capable of identifying and addressing this
 * Copyediting for clarity – this can range from rephrasing paragraphs for grammar to rewriting entire sections in order to explain topics more effectively (often, students are the best source for this, as more seasoned aviators may take certain things for granted that really do warrant a more thorough explanation)
 * Making modifications to content – more rarely, you may find that changes to governing instructions have rendered material factually inaccurate or you might have suggestions for substantively changing what we teach

When editing, don't be shy—be bold instead. If you're pretty certain that something needs to be changed, it probably does. Don't worry too much about making a mistake. Every version of each topic is retained in that page's History, and it's simple to revert back to a previous version if something is changed in error. That having been said, if you're at all unsure, do your research. Talk to your peers, call the course manager, or, better yet, try to verify your changes using official sources. (The ../References/ page is a good place to begin looking.) This will help make sure that your edits benefit the project instead of leading others astray, and it will also have the added advantage of increasing your professional knowledge.

If you think that something needs to be modified but you don't know how to phrase it, can't figure out if it's factually accurate, or if your change is potentially controversial, consider beginning a discourse on that module's Discussion page instead. Others will chime in to help come to a consensus, at which point you, or someone else, can modify the module accordingly.

Other concerns
At this point, I'm sure you can readily see the advantages provided by, and incredible potential of, collaborating as a group on this project. However, you may also be asking yourself a few nervous questions:
 * What keeps someone from editing an article and accidentally including incorrect information?
 * What keeps someone from editing an article and intentionally including incorrect information?
 * What stops someone with malicious intent from vandalizing the entire work?
 * Who's in control of this whole Wikibook thing?

The answer to all four questions, of course, is you! An active community of benevolent readers and contributors is much more powerful than a single bad apple. Any errors that are introduced—accidentally or intentionally—can be easily reverted with a couple of clicks from a page's History. For an incredible example of how the Wiki concept can succeed in creating an accurate reference while remaining completely open and free, take a look at Wikipedia.


text:
SNFO Flight Planning

This document is a Wikibook version of the Flight Training Instruction (FTI) utilized for the Flight Planning course, during the Instrument Navigation (INAV) stage, in the Primary phase of Multi-Service Naval Flight Officer / Air Force Weapon System Officer training, conducted by Training Air Wing SIX, aboard Naval Air Station Pensacola, Florida.

Table of contents

 * Foreword
 * Course Objective
 * Specific Instructional Objective
 * Instructional Procedures
 * Course Calendar
 * Instructors
 * Safety

 * 1) Jet Log
 * 2) Objectives
 * 3) Introduction
 * 4) Departure Section
 * 5) Clearance Section
 * 6) Enroute Navigation Section
 * 7) Alternate Section
 * 8) Fuel Plan Section
 * 9) Emergency “BINGO” To Alternate Section
 * 10) Checklist/Destination/Alternate Section
 * 11) Emergency Fields Section
 * 12) Summary
 * 13) Section Review
 * 14) DD-175 Flight Plan
 * 15) Objectives
 * 16) Introduction
 * 17) DD-175 Flight Plan
 * 18) Service Codes
 * 19) Aircraft Designation and TD Code
 * 20) Route of Flight
 * 21) To/ETE Blocks
 * 22) Terminal Area Delays
 * 23) Summary
 * 24) Section Review
 * 25) Situational Awareness - Making Use of DR Principles and Other Skills
 * 26) Objectives
 * 27) Introduction
 * 28) Wind Triangle
 * 29) Determining Wind
 * 30) Application
 * 31) Summary
 * 32) Section Review
 * 33) Answer Sheet
 * 34) Two-Minute Prior, Mark-on-Top and Wings Level Calls
 * 35) Terminal Objective
 * 36) Enabling Objectives
 * 37) Introduction
 * 38) Two-Minute Prior Call
 * 39) Mark-on-Top Call
 * 40) Wings Level Call
 * 41) Summary
 * 42) Section Review
 * 43) Answer Sheet
 * 44) IN-FLIGHT FUEL AND TIME ANALYSIS
 * 45) Terminal Objective
 * 46) Enabling Objective
 * 47) Introduction
 * 48) DME/GSP RESTRICTIONS
 * 49) Revising ETA
 * 50) REVISING EFR
 * 51) SUMMARY
 * 52) SECTION REVIEW
 * 53) ANSWER SHEET
 * 54) MISSION COMPLETION FEASIBILITY
 * 55) Terminal Objective
 * 56) Enabling Objectives
 * 57) Introduction
 * 58) figuring Fuel Minimums
 * 59) In-Flight Analysis
 * 60) SUMMARY
 * 61) SECTION REVIEW
 * 62) ANSWER SHEET
 * 63) IN-FLIGHT WEATHER ANALYSIS
 * 64) TERMINAL OBJECTIVE
 * 65) ENABLING OBJECTIVE
 * 66) introduction
 * 67) preflight analysis
 * 68) Weather briefings
 * 69) In-Flight Weather Information
 * 70) Weather Avoidance Services
 * 71) Weather Criteria for Filing
 * 72) Summary
 * 73) Section Review
 * 74) Answer Sheet
 * 75) course review
 * 76) purpose
 * 77) description
 * 78) Requirements
 * 79) debrief
 * 80) END-OF-COURSE EXAMINATION/REVIEW
 * 81) DESCRIPTION OF EXAMINATION
 * 82) Time Allocation
 * 83) Materials required
 * 84) Testing procedures
 * 85) Review Procedures
 * 86) Grading queries
 * 87) Grade posting
 * 88) Re-examinations
 * 89) Test grading criteria
 * APPENDIX A - VOICE COMM PROBLEMS
 * PRACTICE PROBLEM #1 (NPA-PAM)
 * PRACTICE PROBLEM #2 (PAM-VAD)
 * PRACTICE PROBLEM #3 (NPA-MEI)
 * ANSWERS TO PRACTICE PROBLEMS 1-3
 * APPENDIX B - T-6 PLANNING DATA
 * APPENDIX C - T-6 2B47 PROFILE DATA
 * APPENDIX D - T-34 PLANNING DATA
 * APPENDIX E - T-34 2B47 PROFILE DATA
 * APPENDIX F - 2B47 GRADING CRITERIA
 * GLOSSARY
 * References

title: SNFO Flight Planning


text:
User talk:Cjrs 79~enwikibooks

Feel free to correct or edit my work as you see fit. Davodd 05:01, 1 Oct 2004 (UTC)

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title: User talk:Cjrs 79~enwikibooks


text: Template:SNFO Flight Planning/NavBar

title: Template:SNFO Flight Planning/NavBar


text:
Sanskrit/Everyday Phrases

Phrases:

Don't forget, please do come - अवश्यं आगन्तव्य, न विस्मर्तव्यम्

Hello/Good Day - नमस्ते Namaste (lit. Greetings to You)

Good morning - शुभ प्रभातम् Shubha Prabhatam

Good afternoon/evening - नमस्ते Namaste

Good night - शुभ रात्रि Shubha Raatri

What is Your Name? - किं तव नाम - Kim tava naama?

I am Richard - अहम् रिचर्ड: Aham Richardah

I am Richard - रिचर्ड अस्मि Richard asmi I am Richard - रिचर्ड अस्मयाहम Richard asm'yaaham

My name is Julia - जूलिया अहम्/ जूलिया अस्मि Julia aham (Juliaaham)/ Julia asmi

My name is Julia - जूलिया इति नाम अदेइम नम Julia iti naama adeiam nama

Words:

Numbers: 1 - अदिम/प्रथम/एकम् Adim/Pratham/Ekam

Ekah Eka Ekam

Dvau Dve Dve

Trayah Tisrah Treeni

Chatvari Chatasrah Chatvaree

The above is a table of usage. The first column is Male gender, the second of female gender, and the third of neuter.

2 - द्व Dva

3 - त्रि Tri

4 - चतुर Chatur

5 - पन्चः Panchaha

6 - षष्ठ Shashta

7 - सप्त Sapta

8 - अष्ट AshTa

9 - नव Nav

10 - दश Dash

100 - शत Shata

1000 - सहस्र Sahasra

Greeting: नमस्ते Namaste - Used for every elder and equal in age

आत्मा Aatma - Soul

पंकज Pankaja - Lotus

पद Pada - Foot

कर Kara - Hands

बाहु Bahu - Arm

 * /Day to Day Conversation in Sanskrit/
 * /Common Phrases/
 * Patatha Samskritam

title: Sanskrit/Everyday Phrases


text:
Introduction to Paleoanthropology/Hominids Early

Overview of Human Evolutionary Origin
The fossil record provides little information about the evolution of the human lineage during the Late Miocene, from 10 million to 5 million years ago. Around 10 million years ago, several species of large-bodied hominids that bore some resemblance to modern orangutans lived in Africa and Asia. About this time, the world began to cool; grassland and savanna habitats spread; and forests began to shrink in much of the tropics.

The creatures that occupied tropical forests declined in variety and abundance, while those that lived in the open grasslands thrived. We know that at least one ape species survived the environmental changes that occurred during the Late Miocene, because molecular genetics tells us that humans, gorillas, bonobos and chimpanzees are all descended from a common ancestor that lived sometime between 7 million and 5 million years ago. Unfortunately, the fossil record for the Late Miocene tells us little about the creature that linked the forest apes to modern hominids.

Beginning about 5 million years ago, hominids begin to appear in the fossil record. These early hominids were different from any of the Miocene apes in one important way: they walked upright (as we do). Otherwise, the earliest hominids were probably not much different from modern apes in their behavior or appearance.

Between 4 million and 2 million years ago, the hominid lineage diversified, creating a community of several hominid species that ranged through eastern and southern Africa. Among the members of this community, two distinct patterns of adaptation emerged:
 * One group of creatures (Australopithecus, Ardipithecus, Paranthropus) evolved large molars that enhanced their ability to process coarse plant foods;
 * The second group, constituted of members of our own genus Homo (as well as Australopithecus garhi) evolved larger brains, manufactured and used stone tools, and relied more on meat than the Australopithecines did.

Sahelanthropus tchadensis ("Toumai")

 * Named in July 2002 from fossils discovered in Chad.
 * Oldest known hominid or near-hominid species (6-7 million years ago).
 * Discovery of nearly complete cranium and number of fragmentary lower jaws and teeth:
 * Skull has very small brain size (ca. 350 cc), considered as primitive apelike feature;
 * Yet, other features are characteristic of later hominids: short and relatively flat face; canines are smaller and shorter; tooth enamel is slightly thicker (suggesting a diet with less fruit).
 * This mixture of features, along with fact that it comes from around the time when hominids are thought to have diverged from chimpanzees, suggests it is close to the common ancestor of humans and chimpanzees.
 * Foramen magnum is oval (not rounded as in chimps) suggesting upright walking position.

Orrorin tugenensis

 * Named in July 2001; fossils discovered in western Kenya.
 * Deposits dated to about 6 million years ago.
 * Fossils include fragmentary arm and thigh bones, lower jaws, and teeth:
 * Limb bones are about 1.5 times larger than those of Lucy, and suggest that it was about the size of a female chimpanzee.
 * Its finders claimed that Orrorin was a human ancestor adapted to both bipedality and tree climbing, and that the australopithecines are an extinct offshoot.

Ardipithecus ramidus

 * Recent discovery announced in Sept. 1994.
 * Dated 4.4 million years ago.
 * Most remains are skull fragments.
 * Indirect evidence suggests that it was possibly bipedal, and that some individuals were about 122 cm (4'0") tall;
 * Teeth are intermediate between those of earlier apes and Austalopithecus afarensis.

Australopithecus anamensis

 * Named in August 1995 from fossils from Kanapoi and Allia Bay in Kenya.
 * Dated between 4.2 and 3.9 million years ago.
 * Fossils show mixture of primitive features in the skull, and advanced features in the body:
 * Teeth and jaws are very similar to those of older fossil apes;
 * Partial tibia (inner calf bone) is strong evidence of bipedality, and lower humerus (the upper arm bone) is extremely humanlike.

Australopithecus afarensis

 * Existed between 3.9 and 3.0 million years ago.
 * A. afarensis had an apelike face with a low forehead, a bony ridge over the eyes, a flat nose, and no chin. They had protruding jaws with large back teeth.
 * Cranial capacity: 375 to 550 cc. Skull is similar to chimpanzee, except for more human-like teeth. Canine teeth are much smaller than modern apes, but larger and more pointed than humans, and shape of the jaw is between rectangular shape of apes and parabolic shape of humans.
 * Pelvis and leg bones far more closely resemble those of modern humans, and leave no doubt that they were bipedal.
 * Bones show that they were physically very strong.
 * Females were substantially smaller than males, a condition known as sexual dimorphism. Height varied between about 107 cm (3'6") and 152 cm (5'0").
 * Finger and toe bones are curved and proportionally longer than in humans, but hands are similar to humans in most other details.

Kenyanthropus platyops ("flat-faced man of Kenya")

 * Named in 2001 from partial skull found in Kenya.
 * Dated to about 3.5 million years ago.
 * Fossils show unusual mixture of features: size of skull is similar to A. afarensis and A. africanus, and has a large, flat face and small teeth.

Australopithecus garhi

 * A. garhi existed around 2.5 Myrs.
 * It has an apelike face in the lower part, with a protruding jaw resembling that of A. afarensis. The large size of the palate and teeth suggests that it is a male, with a small braincase of about 450 cc.
 * It is like no other hominid species and is clearly not a robust form. In a few dental traits, such as the shape of the premolar and the size ratio of the canine teeth to the molars, A. garhi resembles specimens of early Homo. But its molars are huge, even larger than the A. robustus average.
 * Among skeletal finds recovered, femur (upper leg bone) is relatively long, like that of modern humans. But forearm is long too, a condition found in apes and other australopithecines but not in humans.

Australopithecus africanus

 * First identified in 1924 by Raymond Dart, an Australian anatomist living in South Africa.
 * A. africanus existed between 3 and 2 million years ago.
 * Similar to A. afarensis, and was also bipedal, but body size was slightly greater.
 * Brain size may also have been slightly larger, ranging between 420 and 500 cc. This is a little larger than chimp brains (despite a similar body size).
 * Back teeth were a little bigger than in A. afarensis. Although the teeth and jaws of A. africanus are much larger than those of humans, they are far more similar to human teeth than to those of apes. The shape of the jaw is now fully parabolic, like that of humans, and the size of the canine teeth is further reduced compared to A. afarensis.

NOTE: Australopithecus afarensis and A. africanus are known as gracile australopithecines, because of their relatively lighter build, especially in the skull and teeth. (Gracile means "slender", and in paleoanthropology is used as an antonym to "robust"). Despite the use of the word "gracile", these creatures were still more far more robust than modern humans.

Australopithecus aethiopicus

 * A. aethiopicus existed between 2.6 and 2.3 million years ago.
 * Species known mainly from one major specimen: the Black Skull (KNM-WT 17000) discovered at Lake Turkana.
 * It may be ancestor of P. robustus and P. boisei, but it has a baffling mixture of primitive and advanced traits:
 * Brain size is very small (410 cc) and parts of the skull (particularly the hind portions) are very primitive, most resembling A. afarensis;
 * Other characteristics, like massiveness of face, jaws and largest sagittal crest in any known hominid, are more reminiscent of P. boisei.

Paranthropus boisei

 * P. boisei existed between 2.2 and 1.3 million years ago.
 * Similar to P. robustus, but face and cheek teeth were even more massive, some molars being up to 2 cm across. Brain size is very similar to P. robustus, about 530 cc.
 * A few experts consider P. boisei and P. robustus to be variants of the same species.

Paranthropus robustus

 * P. robustus had a body similar to that of A. africanus, but a larger and more robust skull and teeth.
 * It existed between 2 and 1.5 million years ago.
 * The massive face is flat, with large brow ridges and no forehead. It has relatively small front teeth, but massive grinding teeth in a large lower jaw. Most specimens have sagittal crests.
 * Its diet would have been mostly coarse, tough food that needed a lot of chewing.
 * The average brain size is about 530 cc. Bones excavated with P. robustus skeletons indicate that they may have been used as digging tools.

Australopithecus aethiopicus, Paranthropus robustus and P. boisei are known as robust australopithecines, because their skulls in particular are more heavily built.

Homo habilis

 * H. habilis ("handy man")
 * H. habilis existed between 2.4 and 1.5 million years ago.
 * It is very similar to australopithecines in many ways. The face is still primitive, but it projects less than in A. africanus. The back teeth are smaller, but still considerably larger than in modern humans.
 * The average brain size, at 650 cc, larger than in australopithecines. Brain size varies between 500 and 800 cc, overlapping the australopithecines at the low end and H. erectus at the high end. The brain shape is also more humanlike.
 * H. habilis is thought to have been about 127 cm (5'0") tall, and about 45 kg (100 lb) in weight, although females may have been smaller.
 * Because of important morphological variation among the fossils, H. habilis has been a controversial species. Some scientists have not accepted it, believing that all H. habilis specimens should be assigned to either the australopithecines or Homo erectus. Many now believe that H. habilis combines specimens from at least two different Homo species: small-brained less-robust individuals (H. habilis) and large-brained, more robust ones (H. rudolfensis). Presently, not enough is known about these creatures to resolve this debate.


text:
Introduction to Paleoanthropology/Hominids Early Chronology

Between 8 million and 4 million years ago
Fossils of Sahelanthropus tchadensis (6-7 million years) and Orrorin tugenensis (6 million years), discovered in 2001 and 2000 respectively, are still a matter of debate.

The discoverers of Orrorin tugenensis claim the fossils represent the real ancestor of modern humans and that the other early hominids (e.g., Australopithecus and Paranthropus) are side branches. They base their claim on their assessment that this hominid was bipedal (2 million years earlier than previously thought) and exhibited expressions of certain traits that were more modern than those of other early hominids. Other authorities disagree with this analysis and some question whether this form is even a hominid. At this point, there is too little information to do more than mention these two new finds of hominids. As new data come in, however, a major part of our story could change.

Fossils of Ardipithecus ramidus (4.4 million years ago) were different enough from any found previously to warrant creating a new hominid genus. Although the evidence from the foramen magnum indicates that they were bipedal, conclusive evidence from legs, pelvis and feet remain somewhat enigmatic. There might be some consensus that A. ramidus represent a side branch of the hominid family.

Between 4 million and 2 million years ago
Australopithecus anamensis (4.2-3.8 million years ago) exhibit mixture of primitive (large canine teeth, parallel tooth rows) and derived (vertical root of canine, thicker tooth enamel) features, with evidence of bipedalism. There appears to be some consensus that this may represent the ancestor of all later hominids.

The next species is well established and its nature is generally agreed upon: Australopithecus afarensis (4-3 million years ago). There is no doubt that A. afarensis were bipeds. This form seems to still remain our best candidate for the species that gave rise to subsequent hominids.

At the same time lived a second species of hominid in Chad: Australopithecus bahrelghazali (3.5-3 million years ago). It suggests that early hominids were more widely spread on the African continent than previously thought. Yet full acceptance of this classification and the implications of the fossil await further study.

Another fossil species contemporaneous with A. afarensis existed in East Africa: Kenyanthropus platyops (3.5 million years ago). The fossils show a combination of features unlike that of any other forms: brain size, dentition, details of nasal region resemble genus Australopithecus; flat face, cheek area, brow ridges resemble later hominids. This set of traits led its discoverers to give it not only a new species name but a new genus name as well. Some authorities have suggested that this new form may be a better common ancestor for Homo than A. afarensis. More evidence and more examples with the same set of features, however, are needed to even establish that these fossils do represent a whole new taxonomy.

Little changed from A. afarensis to the next species: A. africanus: same body size and shape, and same brain size. There are a few differences, however: canine teeth are smaller, no gap in tooth row, tooth row more rounded (more human-like).

We may consider A. africanus as a continuation of A. afarensis, more widely distributed in southern and possibly eastern Africa and showing some evolutionary changes. It should be noted that this interpretation is not agreed upon by all investigators and remains hypothetical.

Fossils found at Bouri in Ethiopia led investigators to designate a new species: A. garhi (2.5 million years ago). Intriguing mixture of features: several features of teeth resemble early Homo; whereas molars are unusually larger, even larger than the southern African robust australopithecines.

The evolutionary relationship of A. garhi to other hominids is still a matter of debate. Its discoverers feel it is descended from A. afarensis and is a direct ancestor to Homo. Other disagree. Clearly, more evidence is needed to interpret these specimens more precisely, but they do show the extent of variation among hominids during this period.

Two distinctly different types of hominid appear between 2 and 3 million years ago: robust australopithecines (Paranthropus) and early Homo (Homo habilis).

The first type retains the chimpanzee-sized brains and small bodies of Australopithecus, but has evolved a notable robusticity in the areas of the skull involved with chewing: this is the group of robust australopithecines (A. boisei, A. robustus, A. aethiopicus).
 * The Australopithecines diet seems to have consisted for the most part of plant foods, although A. afarensis, A. africanus and A. garhi may have consumed limited amounts of animal protein as well;
 * Later Australopithecines (A. boisei and robustus) evolved into more specialized "grinding machines" as their jaws became markedly larger, while their brain size did not.

The second new hominid genus that appeared about 2.5 million years ago is the one to which modern humans belong, Homo.
 * A Consideration of brain size relative to body size clearly indicates that Homo habilis had undergone enlargement of the brain far in excess of values predicted on the basis of body size alone. This means that there was a marked advance in information-processing capacity over that of Australopithecines;
 * Although H. habilis had teeth that are large by modern standard, they are smaller in relation to the size of the skull than those of Australopithecines. Major brain-size increase and tooth-size reduction are important trends in the evolution of the genus Homo, but not of Australopithecines;
 * From the standpoint of anatomy alone, it has long been recognized that either A. afarensis or A. africanus constitute a good ancestor for the genus Homo, and it now seems clear that the body of Homo habilis had changed little from that of either species. Precisely which of the two species gave rise to H. habilis is vigorously debated. Whether H. habilis is descended from A. afarensis, A. africanus, both of them, or neither of them, is still a matter of debate. It is also possible that none of the known australopithecines is our ancestor. The discoveries of Sahelanthropus tchadensis, Orrorin tugenensis, and A. anamensis are so recent that it is hard to say what effect they will have on current theories.

What might have caused the branching that founded the new forms of robust australopithecines (Paranthropus) and Homo? What caused the extinction, around the same time (between 2-3 million years ago) of genus Australopithecus? Finally, what might have caused the extinction of Paranthropus about 1 million years ago?

No certainty in answering these questions. But the environmental conditions at the time might hold some clues. Increased environmental variability, starting about 6 million years ago and continuing through time and resulting in a series of newly emerging and diverse habitats, may have initially promoted different adaptations among hominid populations, as seen in the branching that gave rise to the robust hominids and to Homo.

And if the degree of the environmental fluctuations continued to increase, this may have put such pressure on the hominid adaptive responses that those groups less able to cope eventually became extinct. Unable to survive well enough to perpetuate themselves in the face of decreasing resources (e.g., Paranthropus, who were specialized vegetarians) these now-extinct hominids were possibly out-competed for space and resources by the better adapted hominids, a phenomenon known as competitive exclusion.

In this case, only the adaptive response that included an increase in brain size, with its concomitant increase in ability to understand and manipulate the environment, proved successful in the long run.

Hominoid, Hominid, Human
The traditional view has been to recognize three families of hominoid: the Hylobatidae (Asian lesser apes: gibbons and siamangs), the Pongidae, and the Hominidae.
 * The Pongidae include the African great apes, including gorillas, chimpanzees and the Asian orangutans;
 * The Hominidae include living humans and typically fossil apes that possess a suite of characteristics such as bipedalism, reduced canine size, and increasing brain size (e.g., australopithecines).

The emergence of hominoids
Hominoids are Late Miocene (15-5 million years ago) primates that share a small number of postcranial features with living apes and humans:
 * no tail;
 * pelvis lacks bony expansion;
 * elbow similar to that of modern apes;
 * somewhat larger brains in relationship to body size than similarly sized monkeys.

When is a hominoid also a hominid?
When we say that Sahelanthropus tchadensis is the earliest hominid, we mean that it is the oldest fossil that is classified with humans in the family Hominidae. The rationale for including Sahelanthropus tchadensis in the Hominidae is based on similarities in shared derived characters that distinguish humans from other living primates.

There are three categories of traits that separate hominids from contemporary apes:
 * bipedalism;
 * much larger brain in relation to body size;
 * dentition and musculature.

To be classified as a hominid, a Late Miocene primate (hominoid) must display at least some of these characteristics. Sahelanthropus tchadensis is bipedal, and shares many dental features with modern humans. However, the brain of Sahelanthropus tchadensis was no bigger than that of contemporary chimpanzees. As a consequence, this fossil is included in the same family (Hominidae) as modern humans, but not in the same genus.

Traits defining early Homo
Early Homo (e.g., Homo habilis) is distinctly different from any of the earliest hominids, including the australopithecines, and similar to us in the following ways:
 * brain size is substantially bigger than that of any of the earliest hominids, including the australopithecines;
 * teeth are smaller, enamel thinner, and the dental arcade is more parabolic than is found in the earliest hominids, including the australopithecines;
 * skulls are more rounded; the face is smaller and protrudes less, and the jaw muscles are reduced compared with earliest hominids, including the australopithecines.


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Introduction to Paleoanthropology/Hominids Early Behavior

One of the most important and intriguing questions in human evolution is about the diet of our earliest ancestors. The presence of primitive stone tools in the fossil record tells us that 2.5 million years ago, early hominids (A. garhi) were using stone implements to cut the flesh off the bones of large animals that they had either hunted or whose carcasses they had scavenged.

Earlier than 2.5 million years ago, however, we know very little about the foods that the early hominids ate, and the role that meat played in their diet. This is due to lack of direct evidence. Nevertheless, paleoanthropologists and archaeologists have tried to answer these questions indirectly using a number of techniques.
 * Primatology (studies on chimpanzee behavior)
 * Anatomical Features (tooth morphology and wear-patterns)
 * Isotopic Studies (analysis of chemical signatures in teeth and bones)

Meat consuming strategy
Earliest ancestors and chimpanzees share a common ancestor (around 5-7 million years ago). Therefore, understanding chimpanzee hunting behavior and ecology may tell us a great deal about the behavior and ecology of those earliest hominids.

In the early 1960s, when Jane Goodall began her research on chimpanzees in Gombe National Park (Tanzania), it was thought that chimpanzees were herbivores. In fact, when Goodall first reported meat hunting by chimpanzees, many people were extremely sceptical.

Today, hunting by chimpanzees at Gombe and other locations in Africa has been well documented.

We now know that each year chimpanzees may kill and eat more than 150 small and medium-sized animals, such as monkeys (red colobus monkey, their favorite prey), but also wild pigs and small antelopes.

Did early hominids hunt and eat small and medium-sized animals? It is quite possible that they did. We know that colobus-like monkeys inhabited the woodlands and riverside gallery forest in which early hominids lived 3-5 Myrs ago. There were also small animals and the young of larger animals to catch opportunistically on the ground.

Many researchers now believe that the carcasses of dead animals were an important source of meat for early hominids once they had stone tools to use (after 2.5 million years ago) for removing the flesh from the carcass. Wild chimpanzees show little interest in dead animals as a food source, so scavenging may have evolved as an important mode of getting food when hominids began to make and use tools for getting at meat.

Before this time, it seems likely that earlier hominids were hunting small mammals as chimpanzees do today and that the role that hunting played in the early hominids' social lives was probably as complex and political as it is in the social lives of chimpanzees.

When we ask when meat became an important part of the human diet, we therefore must look well before the evolutionary split between apes and humans in our own family tree.

Nut cracking
Nut cracking behavior is another chimpanzee activity that can partially reflect early hominin behavior. From Jan. 2006 to May 2006, Susana Carvalho and her colleagues conducted a series of observation on several chimpanzee groups in Bossou and Diecké in Guinea, western Africa. Both direct and indirect observation approach was applied to outdoor laboratory and wild environment scenarios.

The results of this research show three resource-exploitation strategies that chimpanzees apply to utilize lithic material as hammers and anvils to crack nut: 1) Maximum optimization of time and energy (choose the closest spot to process nut). 2) Transport of nuts to a different site or transport of the raw materials for tools to the food. 3) Social strategy such as the behavior of transport of tools and food to a more distant spot. This behavior might relate to sharing of space and resources when various individuals occupy the same area.

The results demonstrate that chimpanzees have similar food exploitation strategies with early hominins which indicate the potential application of primate archaeology to the understanding of early hominin behavior.

What do tooth wear patterns suggest about early hominid behavior?
Bones and teeth in the living person are very plastic and respond to mechanical stimuli over the course of an individual's lifetime. We know, for example, that food consistency (hard vs. soft) has a strong impact on the masticatory (chewing) system (muscles and teeth). Bones and teeth in the living person are therefore tissues that are remarkably sensitive to the environment.

As such, human remains from archaeological sites offer us a retrospective biological picture of the past that is rarely available from other lines of evidence.

Also, new technological advances developed in the past ten years or so now make it possible to reconstruct and interpret in amazing detail the physical activities and adaptations of hominids in diverse environmental settings.

Some types of foods are more difficult to process than others, and primates tend to specialize in different kinds of diets. Most living primates show three basic dietary adaptations: Many primates, such as humans, show a combination of these patterns and are called omnivores, which in a few primates includes eating meat.
 * insectivores (insect eaters);
 * frugivores (fruit eaters);
 * folivores (leaf eaters).

The ingestion both of leaves and of insects requires that the leaves and the insect skeletons be broken up and chopped into small pieces. The molars of folivores and insectivores are characterized by the development of shearing crests on the molars that function to cut food into small pieces. Insectivores' molars are further characterized by high, pointed cusps that are capable of puncturing the outside skeleton of insects. Frugivores, on the other hand, have molar teeth with low, rounded cusps; their molars have few crests and are characterized by broad, flat basins for crushing the food.

In the 1950s, John Robinson developed what came to be known as the dietary hypothesis. According to this theory there were fundamentally two kinds of hominids in the Plio-Pleistocene. One was the "robust" australopithecine (called Paranthropus) that was specialized for herbivory, and the other was the "gracile" australopithecine that was an omnivore/carnivore. By this theory the former became extinct while the latter evolved into Homo.

Like most generalizations about human evolution, Robinson's dietary hypothesis was controversial, but it stood as a useful model for decades.

Detailed analyses of the tooth surface under microscope appeared to confirm that the diet of A. robustus consisted primarily of plants, particularly small and hard objects like seeds, nuts and tubers. The relative sizes and shapes of the teeth of both A. afarensis and A. africanus indicated as well a mostly mixed vegetable diet of fruits and leaves. By contrast, early Homo was more omnivorous.

But as new fossil hominid species were discovered in East Africa and new analyses were done on the old fossils, the usefulness of the model diminished.

For instance, there is a new understanding that the two South African species (A. africanus and A. robustus) are very similar when compared to other early hominid species. They share a suite of traits that are absent in earlier species of Australopithecus, including expanded cheek teeth and faces remodeled to withstand forces generated from heavy chewing.

What do isotopic studies suggest about early hominid behavior?
Omnivory can be suggested by studies of the stable carbon isotopes and strontium(Sr)-calcium(Ca) ratios in early hominid teeth and bones.

For instance, a recent study of carbon isotope (13C) in the tooth enamel of a sample of A. africanus indicated that members of this species ate either tropical grasses or the flesh of animals that ate tropical grasses or both. But because the dentition analyzed by these researchers lacked the tooth wear patterns indicative of grass-eating, the carbon may have come from grass-eating animals. This is therefore a possible evidence that the australopithecines either hunted small animals or scavenged the carcasses of larger ones.

There is new evidence also that A. robustus might not be a herbivore. Isotopic studies reveal chemical signals associated with animals whose diet is omnivorous and not specialized herbivory. The results from 13C analysis indicate that A. robustus either ate grass and grass seeds or ate animals that ate grasses. Since the Sr/Ca ratios suggest that A. robustus did not eat grasses, these data indicate that A. robustus was at least partially carnivorous.

Summary
Much of the evidence for the earliest hominids (Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus ramidus) is not yet available.

Australopithecus anamensis shows the first indications of thicker molar enamel in a hominid. This suggests that A. anamensis might have been the first hominid to be able to effectively withstand the functional demands of hard and perhaps abrasive objects in its diet, whether or not such items were frequently eaten or were only an important occasional food source.

Australopithecus afarensis was similar to A. anamensis in relative tooth sizes and probable enamel thickness, yet it did show a large increase in mandibular robusticity. Hard and perhaps abrasive foods may have become then even more important components of the diet of A. afarensis.

Australopithecus africanus shows yet another increase in postcanine tooth size, which in itself would suggest an increase in the sizes and abrasiveness of foods. However, its molar microwear does not show the degree of pitting one might expect from a classic hard-object feeder. Thus, even A. africanus has evidently not begun to specialize in hard objects, but rather has emphasized dietary breadth (omnivore), as evidenced by isotopic studies.

Subsequent "robust" australopithecines do show hard-object microwear and craniodental specializations, suggesting a substantial departude in feeding adaptive strategies early in the Pleistocene. Yet, recent chemical and anatomical studies on A. robustus suggest that this species may have consumed some animal protein. In fact, they might have specialized on tough plant material during the dry season but had a more diverse diet during the rest of the year.


text:
SNFO Flight Planning/Foreword

Course Objective
To provide the SNFO/SNAV with a level of instrument navigation flight planning knowledge prerequisite to his/her learning, understanding, and performance in flight.

Specific Instructional Objective
Upon completion of this course, the student will demonstrate his/her knowledge of the instrument navigation flight planning by completing the end-of-course examination with a minimum of 80% accuracy and successful completion of all 2B47 training events.

Instructional Procedures

 * 1) Each lesson topic contains the Terminal Objective, Enabling Objectives, description of the subject area and sample questions as well as required amplifying illustrations.
 * 2) The INAV Flight Planning text is designed to reinforce instructors' lectures and demonstrations.
 * 3) Read sections and complete questions at end of sections before class.

title: SNFO Flight Planning/Foreword


text:
JLPT Guide/About JLPT

The Japanese Language Proficiency Test (JLPT) (日本語能力試験 nihongo nōryoku shiken) was created in 1984 in response to the increasing demand of students of the Japanese language to certify their proficiency. There are five levels: N5 (easiest) to N1 (hardest).

Application
The JLPT tests are held twice a year. In December all five levels can be taken but in July only the most difficult levels, levels 1 and 2, can be taken. The test date for winter is in December and the application period is usually September-October.

If you are interested in applying for the JLPT test, you can find your nearest test center online. Also ask about the application period and application fee as they differ in each country. The JLPT is offered in approximately 85 countries.

In Japan, the test is administered by the Japan Educational Exchanges and Services (JEES) (財団法人 日本国際教育支援協会 zaidan hōjin nihon kokusai kyōiku shien kyōkai), while the Japan Foundation (独立行政法人 国際交流基金 dokuritsu gyōsei hōjin kokusai kōryū kikin) administers overseas tests.

Criteria
Important note to students wishing to study in Japanese universities:

The JLPT certification was a requirement for entry into Japanese universities until 2003. The Examination for Japanese University Admission for International Students (EJU) replaces JLPT as the requirement for university entry in Japan. More on this will be written on a separate page.

Test sections
To pass the test, the test taker must be over the minimum overall score and also over the minimum score in each section. N1, N2 and N3 have three scoring sections, while N4 and N5 have two scoring sections. Above tables from Japanese Language Proficiency Test.

Estimated Study Time
Study hour comparison data published by the Japanese Language Education Center:

Old test levels
In 2010, the test changed from four levels to five. Additionally, the criteria for passing the JLPT was changed, requiring a passing mark in all sections of the test, not just an overall passing mark. Some websites have not been updated to reflect this change, but the material on them for N5, N4, and N1 can be considered fairly reliable, since those tests are much the same as before.

title: JLPT Guide/About JLPT


text:
Introduction to Paleoanthropology/Oldowan

The Olduvai Gorge
2 million years ago, Olduvai Gorge (Tanzania) was a lake. Its shores were inhabited not only by numerous wild animals but also by groups of hominids, including Paranthropus boisei and Homo habilis, as well as the later Homo erectus.

The gorge, therefore, is a great source of Palaeolithic remains as well as a key site providing evidence of human evolutionary development. This is one of the main reasons that drew Louis and Mary Leakey back year after year at Olduvai Gorge.

Certain details of the lives of the creatures who lived at Olduvai have been reconstructed from the hundreds of thousands of bits of material that they left behind: various stones and bones. No one of these things, alone, would mean much, but when all are analyzed and fitted together, patterns begin to emerge.

Among the finds are assemblages of stone tools dated to between 2.2 Myrs and 620,000 years ago. These were found little disturbed from when they were left, together with the bones of now-extinct animals that provided food.

Mary Leakey found that there were two stoneworking traditions at Olduvai. One, the Acheulean industry, appears first in Bed II and lasts until Bed IV. The other, the Oldowan, is older and more primitive, and occurs throughout Bed I, as well as at other African sites in Ethiopia, Kenya and Tanzania.

Meat-eating
Until about 2.5 million years ago, early hominids lived on foods that could be picked or gathered: plants, fruits, invertebrate animals such as ants and termites, and even occasional pieces of meat (perhaps hunted in the same manner as chimpanzees do today).

After 2.5 million years ago, meat seems to become more important in early hominids' diet. Evolving hominids' new interest in meat is of major importance in paleoanthropology.

Out on the savanna, it is hard for a primate with a digestive system like that of humans to satisfy its amino-acid requirements from available plant resources. Moreover, failure to do so has serious consequences: growth depression, malnutrition, and ultimately death. The most readily accessible plant resources would have been the proteins accessible in leaves and legumes, but these are hard for primates like us to digest unless they are cooked. In contrast, animal foods (ants, termites, eggs) not only are easily digestible, but they provide high-quantity proteins that contain all the essential amino acids. All things considered, we should not be surprised if our own ancestors solved their "protein problem" in somewhat the same way that chimps on the savanna do today.

Increased meat consumption on the part of early hominids did more than merely ensure an adequate intake of essential amino acids. Animals that live on plant foods must eat large quantities of vegetation, and obtaining such foods consumes much of their time. Meat eaters, by contrast, have no need to eat so much or so often. Consequently, meat-eating hominids may have had more leisure time available to explore and manipulate their environment, and to lie around and play. Such activities probably were a stimulus to hominid brain development.

The importance of meat eating for early hominid brain development is suggested by the size of their brains:
 * cranial capacity of largely plant-eating   Australopithecus ranged from 310 to 530 cc;
 * cranial capacity of primitive known meat eater, Homo habilis: 580 to 752 cc;
 * Homo erectus possessed a cranial capacity of 775 to 1,225 cc.

Hunters or scavengers?
The archaeological evidence indicates that Oldowan hominids ate meat. They processed the carcasses of large animals, and we assume that they ate the meat they cut from the bones. Meat-eating animals can acquire meat in several different ways:
 * stealing kills made by other animals;
 * by opportunistically exploiting the carcasses	of animals that die naturally;
 * by hunting or capturing prey themselves.

There has been considerable dispute among anthropologists about how early hominids acquired meat. Some have argued that hunting, division of labor, use of home bases and food sharing emerged very early in hominid history. Others think the Oldowan hominids would have been unable to capture large mammals because they were too small and too poorly armed.

Recent zooarchaeological evidence suggests that early hominids (after 2.5 million years ago) may have acquired meat mainly by scavenging, and maybe occasionally by hunting.

If hominids obtained most of their meat from scavenging, we would expect to find cut marks mainly on bones left at kill sites by predators (lions, hyenas). If hominids obtained most of their meat from their own kills, we would expect to find cut marks mainly on large bones, like limb bones. However, at Olduvai Gorge, cut marks appear on both kinds of bones: those usually left by scavengers and those normally monopolized by hunters. The evidence from tool marks on bones indicates that humans sometimes acquired meaty bones before, and sometimes after, other predators had gnawed on them.

Settlement patterns
During decades of work at Olduvai Gorge, Mary and Louis Leakey and their team laid bare numerous ancient hominid sites. Sometimes the sites were simply spots where the bones of one or more hominid species were discovered. Often, however, hominid remains were found in association with concentrations of animal bones, stone tools, and debris.

At one spot, in Bed I, the bones of an elephant lay in close association with more than 200 stone tools. Apparently, the animal was butchered here; there are no indications of any other activity.

At another spot (DK-I Site), on an occupation surface 1.8 million years old, basalt stones were found grouped in small heaps forming a circle. The interior of the circle was practically empty, while numerous tools and food debris littered the ground outside, right up to the edge of the circle.

Principles
Use of specially made stone tools appears to have arisen as result of need for implements to butcher and prepare meat, because hominid teeth were inadequate for the task. Transformation of lump of stone into a "chopper", "knife" or "scraper" is a far cry from what a chimpanzee does when it transforms a stick into a termite probe. The stone tool is quite unlike the lump of stone. Thus, the toolmaker must have in mind an abstract idea of the tool to be made, as well as a specific set of steps that will accomplish the transformation from raw material to finished product. Furthermore, only certain kinds of stone have the flaking properties that will allow the transformation to take place, and the toolmaker must know about these.

Therefore, two main components to remember:
 * Raw material properties
 * Flaking properties

Evidence
The oldest Lower Palaeolithic tools (2.0-1.5 million years ago) found at Olduvai Gorge (Homo habilis) are in the Oldowan tool tradition. Nevertheless, older materials (2.6-2.5 million year ago) have recently been recorded from sites located in Ethiopia (Hadar, Omo, Gona, Bouri - Australopithecus garhi) and Kenya (Lokalalei).

Because of a lack of remarkable differences in the techniques and styles of artifact manufacture for over 1 million years (2.6-1.5 million years ago), a technological stasis was suggested for the Oldowan Industry.

The makers of the earliest stone artifacts travelled some distances to acquire their raw materials, implying greater mobility, long-term planning and foresight not recognized earlier.

Oldowan stone tools consist of all-purpose generalized chopping tools and flakes. Although these artifacts are very crude, it is clear that they have been deliberately modified. The technique of manufacture used was the percussion.

The main intent of Oldowan tool makers was the production of cores and flakes with sharp-edges. These simple but effective Oldowan choppers and flakes made possible the addition of meat to the diet on a regular basis, because people could now butcher meat, skin any animal, and split bones for marrow.

Overall, the hominids responsible for making these stone tools understood the flaking properties of the raw materials available; they selected appropriate cobbles for making artifacts; and they were as competent as later hominids in their knapping abilities.

Finally, the manufacture of stone tools must have played a major role in the evolution of the human brain, first by putting a premium on manual dexterity and fine manipulation over mere power in the use of the hands. This in turn put a premium in the use of the hands.

Early hominid behavior
During the 1970s and 1980s many workers, including Mary Leakey and Glynn Isaac, used an analogy from modern hunter-gatherer cultures to interpret early hominid behavior of the Oldowan period (e.g., the Bed I sites at Olduvai Gorge). They concluded that many of the sites were probably camps, often called "home bases", where group members gathered at the end of the day to prepare and share food, to socialize, to make tools, and to sleep.

The circular concentration of stones at the DK-I site was interpreted as the remains of a shelter or windbreak similar to those still made by some African foraging cultures. Other concentrations of bones and stones were thought to be the remains of living sites originally ringed by thorn hedges for defense against predators. Later, other humanlike elements were added to the mix, and early Homo was described as showing a sexual division of labor [females gathering plant foods and males hunting for meat] and some of the Olduvai occupation levels were interpreted as butchering sites.

Views on the lifestyle of early Homo began to change in the late 1980s, as many scholars became convinced that these hominids had been overly humanized.

Researchers began to show that early Homo shared the Olduvai sites with a variety of large carnivores, thus weakening the idea that these were the safe, social home bases originally envisioned.

Studies of bone accumulations suggested that H. habilis was mainly a scavenger and not a full-fledged hunter. The bed I sites were interpreted as no more than "scavenging stations" where early Homo brought portions of large animal carcasses for consumption.

Another recent suggestion is that the Olduvai Bed I sites mainly represent places where rocks were cached for the handy processing of animal foods obtained nearby. Oldowan toolmakers brought stones from sources several kilometers away and cached them at a number of locations within the group's territory. Stone tools could have been made at the cache sites for use elsewhere, but more frequently portions of carcasses were transported to the toolmaking site for processing.

Summary
Current interpretations of the subsistence, settlement, and tool-use patterns of early hominids of the Oldowan period are more conservative than they have been in the past. Based upon these revised interpretations, the Oldowan toolmakers have recently been dehumanized.

Although much more advanced than advanced apes, they still were probably quite different from modern people with regard to their living arrangements, methods and sexual division of food procurement and the sharing of food.

The label human has to await the appearance of the next representative of the hominid family: Homo erectus.


text:
Introduction to Paleoanthropology/Acheulean

In 1866, German biologist Ernst Haeckel had proposed the generic name "Pithecanthropus" for a hypothetical missing link between apes and humans.

In late 19th century, Dutch anatomist Eugene Dubois was on the Indonesian island of Java, searching for human fossils. In the fall of 1891, he encountered the now famous Trinil skull cap. The following year his crew uncovered a femur, a left thigh bone, very similar to that of modern humans. He was convinced he had discovered an erect, apelike transitional form between apes and humans. In 1894, he decided to call his fossil species Pithecanthropus erectus. Dubois found no additional human fossils and he returned to the Netherlands in 1895.

Others explored the same deposits on the island of Java, but new human remains appeared only between 1931 and 1933.

Dubois's claim for a primitive human species was further reinforced by nearly simultaneous discoveries from near Beijing, China (at the site of Zhoukoudian). Between 1921 and 1937, various scholars undertook fieldwork in one collapsed cave (Locality 1) recovered many fragments of mandibles and skulls. One of them, Davidson Black, a Canadian anatomist, created a new genus and species for these fossils: Sinanthropus pekinensis ("Peking Chinese man").

In 1939, after comparison of the fossils in China and Java, some scholars concluded that they were extremely similar. They even proposed that Pithecanthropus and Sinanthropus were only subspecies of a single species, Homo erectus, though they continued to use the original generic names as labels.

From 1950 to 1964, various influential authorities in paleoanthropology agreed that Pithecanthropus and Sinanthropus were too similar to be placed in two different genera; and, by the late 1960s, the concept of Homo erectus was widely accepted.

To the East Asian inventory of H. erectus, many authorities would add European and especially African specimens that resembled the Asian fossil forms. In 1976, a team led by Richard Leakey discovered around Lake Turkana (Kenya) an amazingly well-preserved and complete skeleton of a H. erectus boy, called the Turkana Boy (WT-15000).

In 1980s and 1990s:
 * new discoveries in Asia (Longgupo, Dmanisi, etc.); in Europe (Atapuerca, Orce, Ceprano);
 * precision in chronology and evolution of H. erectus;
 * understanding and definition of variability of this species and relationship with other contemporary species.

Africa
Unlike Australopithecines and even Homo habilis, Homo ergaster/erectus was distributed throughout Africa:
 * about 1.5 million years ago, shortly after the emergence of H. ergaster, people more intensively occupied the Eastern Rift Valley;
 * by 1 million years ago, they had extended their range to the far northern and southern margins of Africa.

Traditionally, Homo erectus has been credited as being the prehistoric pioneer, a species that left Africa about 1 million years ago and began to disperse throughout Eurasia. But several important discoveries in the 1990s have reopened the question of when our ancestors first journeyed from Africa to other parts of the globe. Recent evidence now indicates that emigrant erectus made a much earlier departure from Africa.

Israel
Ubeidiyeh
 * Deposits accumulated between 1.4-1.0 million years ago;
 * Stone tools of both an early chopper-core (or Developed Oldowan) industry and crude Acheulean-like handaxes. The artifacts closely resemble contemporaneous pieces from Upper Bed II at Olduvai Gorge;
 * Rare hominid remains attributed to Homo erectus;
 * Ubeidiya might reflect a slight ecological enlargement of Africa more than a true human dispersal.

Gesher Benot Yaaqov
 * 800,000 years ago;
 * No hominid remains;
 * Stone tools are of Acheulean tradition and strongly resemble East African industries.

Republic of Georgia
In 1991, archaeologists excavating a grain-storage pit in the medieval town of Dmanisi uncovered the lower jaw of an adult erectus, along with animal bones and Oldowan stone tools.

Different dating techniques (paleomagnetism, potassium-argon) gave a date of 1.8 million years ago, that clearly antedate that of Ubeidiya. Also the evidence from Dmanisi suggests now a true migration from Africa.

China
Longgupo Cave
 * Dated to 1.8 million years ago
 * Fragments of a lower jaw belonging either to Homo erectus or an unspecified early Homo.
 * Fossils recovered with Oldowan tools.

Zhoukoudian
 * Dated between 500,000 and 250,000 years ago.
 * Remarkable site for providing large numbers of fossils, tools and other artifacts.
 * Fossils of Homo erectus discovered in 1920s and 1930s.

Java
In 1994, report of new dates from sites of Modjokerto and Sangiran where H. erectus had been found in 1891.

Geological age for these hominid remains had been estimated at about 1 million years old. Recent redating of these materials gave dates of 1.8 million years ago for the Modjokerto site and 1.6 million years ago for the Sangiran site.

These dates remained striking due to the absence of any other firm evidence for early humans in East Asia prior to 1 Myrs ago. Yet the individuals from Modjokerto and Sangiran would have certainly traveled through this part of Asia to reach Java.

Europe
Did Homo ergaster/erectus only head east into Asia, altogether bypassing Europe?

Many paleoanthropologists believed until recently that no early humans entered Europe until 500,000 years ago. But the discovery of new fossils from Spain (Atapuerca, Orce) and Italy (Ceprano) secured a more ancient arrival for early humans in Europe.

At Atapuerca, hundreds of flaked stones and roughly eighty human bone fragments were collected from sediments that antedate 780,000 years ago, and an age of about 800,000 years ago is the current best estimate. The artifacts comprise crudely flaked pebbles and simple flakes. The hominid fossils - teeth, jaws, skull fragments - come from several individuals of a new species named Homo antecessor. These craniofacial fragments are striking for derived features that differentiate them from Homo ergaster/erectus, but do not ally them specially with either H. neanderthalensis or H. sapiens.


text: Template:LPI Linux Certification/LPIC

title: Template:LPI Linux Certification/LPIC


text: Template:SNFO Flight Planning/PD-USGov

title: Template:SNFO Flight Planning/PD-USGov


text:
Financial Derivatives

This wikibook is devoted to detailing the methods for trading and evaluating financial derivatives, such as futures and options. This wikibook assumes a strong grasp of differential equations and some understanding of statistics. The ideas introduced will not make you into a good trader. They will merely provide you with some of the tools that derivatives traders use.

Detailed contents list

 * Chapter 1 ~ Introduction

 * Chapter 2 ~ Basic Derivatives Contracts
 * Forwards
 * Futures
 * Swaps
 * Options
 * Advanced Structures

 * Chapter 3 ~ Pricing of Derivatives

 * Chapter 4 ~ Derivatives in Risk Management

 * Chapter 5 ~ Real Options

 * References ~ References

 * Appendix I ~ Notions of Probability Theory

 * Appendix II ~ Notions of Stochastic Calculus

= References = Fischer Black, "The pricing of commodity contracts", The Journal of Financial Economics, 3 (1976), pp. 167–179.

Stephen A. Ross, "Neoclassical Finance (Princeton Lectures in Finance)", Princeton University Press, 2004.

title: Financial Derivatives