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Jakarta EE Programming/Jakarta Enterprise Beans

EJB stands for Enterprise JavaBeans. Freshers should not confuse this with Java Beans of Core Java.

Introduction
This page is about Enterprise JavaBeans 2.1. It also covers EJB 2.0, which is still in widespread use. Just as the Java platform has revolutionized the way we think about software development, Enterprise JavaBeans has revolutionized the way we think about developing mission-critical enterprise software. It combines server-side components with distributed object technologies, asynchronous messaging, and web services to greatly simplify the task of application development. It automatically takes into account many of the requirements of business systems, including security, resource pooling, persistence, concurrency, and transactional integrity.

This book shows you how to use Enterprise JavaBeans to develop scalable, portable business systems. But before we can start talking about EJB itself, we'll need a brief introduction to the technologies addressed by EJB, such as component models, distributed objects, asynchronous messaging, and web services. It's particularly important to have a basic understanding of component transaction monitors, the technology that lies beneath EJB.

It is assumed that you're already familiar with Java; if you're not, read Java Programming first. This book also assumes that you're conversant in the JDBC API, or at least in SQL. If you're not familiar with JDBC, see Java JDBC using SQLite.

One of Java's most important features is platform independence. Since it was first released, Java has been marketed as "write once, run anywhere." While the hype has gotten a little heavy-handed at times, code written with Sun's Java programming language is remarkably platform-independent. Enterprise JavaBeans isn't just platform-independent—it's also implementation-independent. If you've worked with JDBC, you know a little about what this means. Not only can the JDBC API run on a Windows machine or on a Unix machine, it can also access relational databases of many different vendors (DB2, Oracle, MySQL, SQLServer, etc.) by using different JDBC drivers. You don't have to code to a particular database implementation—just change JDBC drivers, and you change databases. It's the same with EJB. Ideally, an EJB component—an enterprise bean—can run in any application server that implements the EJB specification. This means that you can develop and deploy your EJB business system in one server, such as BEA's WebLogic, and later move it to a different EJB server, such as Pramati, Sybase EAServer, IBM's WebSphere, or an open source project such as Apache Geronimo, OpenEJB, JOnAS, or JBoss. Implementation independence means that your business components are not dependent on the brand of server, which gives you many more options before, during, and after development and deployment.

In addition to supporting distributed business objects, Enterprise JavaBeans supports asynchronous messaging. EJB 2.1 also allows enterprise beans to be exposed as web services, so that their methods can be invoked by other J2EE applications as well as applications written in other programming languages on a variety of platforms. Web services in EJB 2.1 supports both RPC-style and document-style messaging. Support for web services is based on a new web service API: JAX-RPC.

Server-Side Components
Object-oriented languages such as Java, C++, and C# are used to write software that is flexible, extensible, and reusable—the three axioms of object-oriented development. In business systems, object-oriented languages are used to improve development of GUIs, to simplify access to data, and to encapsulate the business logic. The encapsulation of business logic into business objects is a fairly recent focus in the information-technology industry. Business is fluid, which means that a business's products, processes, and objectives evolve over time. If the software that models the business can be encapsulated into business objects, it becomes flexible, extensible, and reusable, and therefore evolves as the business evolves.

A server-side component model may define an architecture for developing distributed business objects that combine the accessibility of distributed object systems with the fluidity of objectified business logic. Server-side component models are used on the middle-tier application servers, which manage the components at runtime and make them available to remote clients. They provide a baseline of functionality that makes it easy to develop distributed business objects and assemble them into business solutions.

Server-side components can also be used to model other aspects of a business system, such as presentation and routing. The Java servlet, for example, is a server-side component that is used to generate HTML and XML data for the presentation layer of a three-tier architecture. EJB 2.1 message-driven beans, which are discussed later in this book, are server-side components that can be used to consume and process asynchronous messages.

Server-side components, like other components, can be bought and sold as independent pieces of executable software. They conform to a standard component model and can be executed without direct modification in a server that supports that component model. Server-side component models often support attribute-based programming, which allows the runtime behavior of the component to be modified when it is deployed, without having to change the programming code in the component. Depending on the component model, the server administrator can declare a server-side component's transactional, security, and even persistence behavior by setting these attributes to specific values.

As an organization's services, products, and operating procedures evolve, server-side components can be reassembled, modified, and extended so that the business system reflects those changes. Imagine a business system as a collection of server-side components that model concepts such as customers, products, reservations, and warehouses. Each component is like a Lego™ block that can be combined with other components to build a business solution. Products can be stored in the warehouse or delivered to a customer; a customer can make a reservation or purchase a product. You can assemble components, take them apart, use them in different combinations, and change their definitions. A business system based on server-side components is fluid because it is objectified, and it is accessible because the components can be distributed.

Enterprise JavaBeans Defined
Oracle's definition of Enterprise JavaBeans is:

 * "The Enterprise JavaBeans architecture is a component architecture for the development and deployment of component-based distributed business applications. Applications written using the Enterprise JavaBeans architecture are scalable, transactional, and multi-user secure. These applications may be written once, and then deployed on any server platform that supports the Enterprise JavaBeans specification."

That's a mouthful, but it's not atypical of how Sun defines many of its Java technologies—have you ever read the definition of the Java language itself? It's about twice as long. This book offers a shorter definition of EJB:

Enterprise JavaBeans is a standard server-side component model for distributed business applications.

What this means is the EJB offers a standard model for building server-side components that represent both business objects (customers, items in inventory, and the like) and business processes (purchasing, stocking, and so on). Once you have built a set of components that fit the requirements of your business, you can combine them to create business applications. On top of that, as “distributed” components, they don’t all have to reside on the same server: Components can reside wherever it’s most convenient: a Customer component "live" near the Customer database, a Part component can “live” near the inventory database, and a Purchase business-process component can “live” near the user interface: you can do whatever’s necessary for minimizing latency, sharing the processing load, or maximizing reliability.

Distributed Object Architectures
To understand EJB, you need to understand how distributed objects work. Distributed object systems are the foundation for modern three-tier architectures. In a three-tier architecture, as shown in Figure 1-1, the presentation logic resides on the client (first tier), the business logic resides on the middle tier (second tier), and other resources, such as the database, reside on the backend (third tier).

Figure 1-1. Three-tier architecture
All distributed object protocols are built on the same basic architecture, which is designed to make an object on one computer look like it's residing on a different computer. Distributed object architectures are based on a network communication layer that is really simple. Essentially, there are three parts to this architecture: the business object, the skeleton, and the stub.

The business object resides on the middle tier. It's an instance of an object that models the state and business logic of some real-world concept, such as a person, order, or account. Every business object class has matching stub and skeleton classes built specifically for that type of business object. For example, a distributed business object called  would have matching   and   classes. As shown in Figure 1-2, the business object and skeleton reside on the middle tier, and the stub resides on the client.

The stub and the skeleton are responsible for making the business object on the middle tier look as if it is running locally on the client machine. This is accomplished through some kind of Remote Method Invocation (RMI) protocol. An RMI protocol is used to communicate method invocations over a network. CORBA, Java RMI, and Microsoft .NET all use their own protocols. Every instance of the business object on the middle tier is wrapped by an instance of its matching skeleton class. The skeleton is set up on a port and IP address and listens for requests from the stub, which resides on the client machine and is connected via the network to the skeleton. The stub acts as the business object's surrogate on the client and is responsible for communicating requests from the client to the business object through the skeleton. Figure 1-2 illustrates the process of communicating a method invocation from the client to the server object and back. The stub and the skeleton hide the communication specifics of the RMI protocol from the client and the implementation class, respectively.

Figure 1-2. RMI loop
The business object implements a public interface that declares its business methods. The stub implements the same interface as the business object, but the stub's methods do not contain business logic. Instead, the business methods on the stub implement whatever networking operations are required to forward the request to the business object and receive the results. When a client invokes a business method on the stub, the request is communicated over the network by streaming the name of the method invoked, and the values passed in as parameters, to the skeleton. When the skeleton receives the incoming stream, it parses the stream to discover which method is requested, then invokes the corresponding business method on the business object. Any value that is returned from the method invoked on the business object is streamed back to the stub by the skeleton. The stub then returns the value to the client application as if it had processed the business logic locally.

Component Models
The term component model has many different interpretations. Enterprise JavaBeans specifies a server-side component model. Using a set of classes and interfaces from the  package, developers can create, assemble, and deploy components that conform to the EJB specification. The original JavaBeans™ is also a component model, but it's not a server-side component model like EJB. In fact, other than sharing the name "JavaBeans," these two component models are completely unrelated. In the past, a lot of the literature referred to EJB as an extension of the original JavaBeans, but it was a misrepresentation. The two APIs serve very different purposes, and EJB does not extend or use the original.

JavaBeans component model
JavaBeans is intended to be used for intra process purposes, while EJB is designed for inter process components. In other words, the original JavaBeans was not intended for distributed components. JavaBeans can be used to solve a variety of problems, but it is primarily used to build clients by assembling visual (GUI) and nonvisual widgets. It's an excellent component model, possibly the best one ever devised for intraprocess development, but it's not a server-side component model. EJB, on the other hand, is explicitly designed to address issues involved with managing distributed business objects in a three-tier architecture.

Given that JavaBeans and Enterprise JavaBeans are completely different, why are they both called component models? In this context, a component model defines a set of contracts between the component developer and the system that hosts the component. The contracts express how a component should be developed and packaged. Once a component is defined, it becomes an independent piece of software that can be distributed and used in other applications. A component is developed for a specific purpose but not a specific application. In the original JavaBeans, a component might be a push button or a spreadsheet that can be used in any GUI application according to the rules specified in the original JavaBeans component model. In EJB, there are several different types of components: components that represent entities in a database (entity beans) have a slightly different contract with their container than components that represent business processes (session beans). For example, a component might be a Customer business object, represented by an entity bean, that can be deployed in any EJB server and used to develop any business application that needs a customer business object. Another type of component might be a  object, represented by a session bean, that models what happens when a customer buys a particular product. (Although the act of making a purchase isn’t itself represented in a database, a purchase involves a complex interaction between a customer, a sales person, inventory, accounts receivable, and possibly other entities). The  object has a different contract with its container than the   object, but it too can still be deployed in any EJB server and used in any business application that needs to support purchases. A third type of EJB, the MessageDrivenBean, has a slightly different contract with its container—but it, too, can be deployed in any EJB server.

Competing Component Models: Microsoft's .NET Framework
Enterprise JavaBeans did not appear out of nowhere; it is one of a number of component transaction monitors (CTMs), which in turn have their origin in older transaction processing monitors (such as Tuxedo) and Object Request Brokers. However, the most important competition for EJB is Microsoft’s .NET framework. .NET has its origins in the Microsoft Transaction Server (MTS), which was arguably the first commercially available CTM. MTS was later renamed COM+. Microsoft's COM+ is based on the Component Object Model (COM), originally designed for use on the desktop but eventually pressed into service as a server-side component model. For distributed access, COM+ clients use the Distributed Component Object Model (DCOM).

When MTS was introduced in 1996, it was an exciting development because it provided a comprehensive environment for business objects. With MTS, application developers could write COM components without worrying about system-level concerns. Once a business object was designed to conform to the COM model, MTS (and now COM+) took care of everything else, including transaction management, concurrency, and resource management.

COM+ has become part of Microsoft's new .NET Framework. The core functionality provided by COM+ services remains essentially the same in .NET, but the way it appears to a developer has changed significantly. Rather than writing components as COM objects, .NET Framework developers build applications as managed objects. All managed objects, and in fact all code written for the .NET Framework, depends on a Common Language Runtime (CLR). For Java-oriented developers, the CLR is much like a Java virtual machine (VM), and a managed object is analogous to an instance of a Java class; i.e., to a Java object.

The .NET Framework provides first class support web services via the SOAP (Simple Object Access Protocol) protocol, which enables business components in the .NET world to communicate with applications on any other platform written in any language. This can potentially make business components in .NET universally accessible, a feature that is not easily dismissed. In fact, .NET was the impetus that motivated Sun Microsystems to extend EJB and the rest of the J2EE platform to support web services. Microsoft's .NET platform represents the greatest threat to the dominance of the Java platform since the Java programming language was introduced in 1995.

Although the .NET Framework provides many interesting features, it falls short as an open standard. The COM+ services in the .NET Framework are Microsoft's proprietary CTM, which means that using this technology binds you to the Microsoft platform. If your company plans to deploy server-side components on a non-Microsoft platform, .NET is not a viable solution. In addition, the COM+ services in the .NET Framework are focused on stateless components; there's no built-in support for persistent transactional objects. Although stateless components can offer higher performance, business systems need the kind of flexibility offered by CTMs, which include stateful and persistent components.

Benefits of a Standard Server-Side Component Model
What does it mean to be a standard server-side component model? Quite simply, it means that you can develop business objects using the Enterprise JavaBeans component model and expect them to work in any application server that supports the complete EJB specification. This is a pretty powerful statement, because it largely eliminates the biggest problem faced by potential customers of Microsoft .NET products: fear of vendor "lock-in." With a standard server-side component model, customers can commit to using an EJB-compliant application server with the knowledge that they can migrate to a better server if one becomes available. Obviously, care must be taken when using proprietary extensions developed by vendors, but this is nothing new. Even in the relational database industry—which has been using the SQL standard for a couple of decades—optional proprietary extensions abound.

Having a standard server-side component model has benefits beyond implementation independence. A standard component model provides a vehicle for growth in the third-party products. If numerous vendors support EJB, creating add-on products and component libraries is more attractive to software vendors. The IT industry has seen this type of cottage industry grow up around other standards, such as SQL; hundreds of add-on products can now be purchased to enhance business systems with data that is stored in SQL-compliant relational databases. Report-generating tools and data-warehouse products are typical examples. The GUI component industry has also seen the growth of its own third-party products. A healthy market for component libraries already exists for GUI component models such as Sun's original JavaBeans component model.

Many third-party products for Enterprise JavaBeans exist today. Add-on products for credit card processing, legacy database access, and other business services have been introduced for various EJB-compliant systems. These types of products make development of EJB systems simpler and faster than the alternatives, making the EJB component model attractive to corporate IS and server vendors alike. The market for prepackaged EJB components is growing in several domains, including sales, finance, education, web-content management, collaboration, and other areas.

Titan Cruises: An Imaginary Business
To make things a little easier, and more fun, we will discuss all the concepts in this book in the context of one imaginary business, a cruise line called Titan. A cruise line makes a particularly interesting example because it incorporates several different businesses: it has ship cabins that are similar to hotel rooms, it serves meals like a restaurant, it offers various recreational opportunities, and it needs to interact with other travel businesses.

This type of business is a good candidate for a distributed object system because many of the system's users are geographically dispersed. Commercial travel agents, for example, who need to book passage on Titan ships will need to access the reservation system. Supporting many—possibly hundreds—of travel agents requires a robust transactional system to ensure that agents have access and that reservations are completed properly. Throughout this book, we will build a fairly simple slice of Titan's EJB system that focuses on the process of making a reservation for a cruise. This exercise will give us an opportunity to develop Ship, Cabin, TravelAgent, ProcessPayment, and other enterprise beans. In the process, you will need to create relational database tables for persisting data used in the example. It is assumed that you are familiar with relational database management systems and that you can create tables according to the SQL statements provided. EJB can be used with any kind of database or legacy application, but relational databases seem to be the most commonly understood database, so I have chosen this as the persistence layer.

What's Next?
To develop business objects using EJB, you have to understand the life cycle and architecture of EJB components. This means understanding conceptually how EJB's components are managed and made available as distributed objects.


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Beekeeping/Allergies

If you are allergic to bee stings, you need to ask the advice of your doctor on measures you should take if stung.

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

title: Beekeeping/Allergies


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User talk:24.10.134.246

Opposites
Sorry, but we do not accept fiction at Wikibooks: WB:WIN. I had to remove your work. --Derbeth 15:20, 10 October 2005 (UTC)

title: User talk:24.10.134.246


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Neuroscience/Cognitive Neuroscience/Motivation

Dopamine release in the nucleus accumbens is essential for the neural circuit that controls reward-seeking in response to reward-predictive cues. Injection of dopamine receptor antagonists into the accumbens severely impairs an animal’s ability to perform operant behaviors specified by predictive cues. Furthermore, inhibitions and excitations of accumbens neurons evoked by such cues are abolished by inactivation of the ventral tegmental area, the major dopaminergic input to the accumbens. Dopamine is necessary to elicit neural activity in the accumbens that drives the behavioral response to cues. Accumbens dopamine release is causal to the rats’ reward-seeking behavioral response. Dopamine in this structure is both necessary and sufficient to promote the appropriate behavioral response to reward-predictive cues. (Nicola et al, 2005)


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Budget Watch Collecting/Unknown Swiss Made

"I've checked Google, and can't find any information on my watch--The brand is AcmeTime, marked R-Swiss-R at the bottom...."

The bad news is there were thousands of these brands with almost no information available. The way the Swiss watch industry worked was that there were a very few companies that made most of their own parts--Most bought either complete movements or Ébauches ("movement kits") from one of a few movement houses (now mostly owned by the Swatch group), and frequently bought cases from someone, and dials from someone, and... Sometimes these would be assembled by the brand, other times they were assembled by someone else.

This isn't unique to the Swiss--American watch companies worked in a similar way. When you bought an early Elgin or Waltham pocketwatch, you usually bought a movement with dial and hands, and had it cased by your local jeweler in a case of your choice, sold by an unrelated company. The difference here is that your watch would be known as an Elgin, rather than by the name of the casemaker or whoever assembled it.

The good news is that you can usually identify the movement used in these "generic Swiss" watches, and that will give at least a few clues as to quality, market and era. Most of these will have a movement number--Usually under the balance wheel, sometimes on a bridge and occasionally on the dial side of the main plate. Roland Ranfft has a great Movement Database with a search feature and great illustrations--Type whatever you think the number is, and see if it matches the picture.

Incidentally, the R-Swiss-R is a clue that the watch dial is before 1968, and likely sometime in the 1950's or older. The R stands for Radium, used to make the hands glow in early watches. In many ways it was superior to modern glow, as it would glow for years without exposure to light. Unfortunately it is also slightly dangerous. Radium was replaced by Tritium, a weaker and much, much safer radioactive compound, and later by Luminova and Lumabright, phosphor-based chemicals that will glow for many hours after brief exposure to light. Some replica watches will have Tritium markings, even though they use non-Tritium lume.


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Budget Watch Collecting/Timex movement clean and lube

Generic instructions for cleaning a Timex pinlever mechanical or a similar non-jeweled movement. This is a modification from the official 1966 Timex service manual procedure. If using these steps on a non-Timex, you need to handle the mainspring differently--Timex has a lubricating coating that isn't removed by watch cleaning solutions. Other watches will either need the mainspring to be re-lubricated (preferably) or at least removed prior to cleaning so the existing lube isn't washed away.

This is essentially a rough draft. If you have questions, please ask in the discussion section.

Most "overwound" "wound too tight" or similar mechanical watches are just dirty. Timex are particularly easy to clean, since little disassembly is needed.

Tools:

Case knife

Jeweler's screwdrivers

Cleaner

Watch oil

Oiler (or blunted insulin syringe)

I'd use household ammonia for about 5-10 minutes, followed by Ronsonol lighter fluid (Naphtha) as a rinse. I personally use L and R cleaning fluids in an L and R machine, but that's a bit extreme for normal people (I work on a couple of watches a week, and do mostly jeweled movements). Frequently naptha itself will work, but sometimes it won't remove heavy deposits. Some have had success with shampoo or dish soap and water--However I recommend rinsing in Naphtha after any water-based solution.

If the watch is not a Timex, let down the mainspring. There should be a medium sized gear near the stem meshing with a larger one at the mainspring. One of these gears will have the "click", the device that keeps the mainspring from unwinding at the stem. Wind the stem a tiny bit and hold pressure, and with a small screwdriver hold the click so it does not mesh with the gears. Slowly let the stem unwind--if you begin to lose your grip, let the click go while you get your grip back.

On most watches, remove the back, then remove the stem. In some cases the "stem hole" is between case and back, on these you will not need to remove the stem before moving the movement

Most Timex movements have a lever holding the stem, and you just back off the screw that holds the lever, don't completely remove it. Others have a lever that needs to be lifted off the stem--In this case, prying down with a screwdriver here will lift the lever off the stem.

Other movements may have a screw or button close to where the stem enters the movement--buttons get pushed, screws get backed out while trying to wiggle the stem out--stop when the stem comes out, you don't want to completely undo this screw. A few movements can only be removed through the front, with a variety of methods of dealing with the stem. In some the back will come off to release the stem, some the bezel is removed and the stem is between the bezel and main case. In a few a special wrench is needed to unscrew the crown.

Remove the second hand if it's got one. I use a hand puller, it can be done with screwdrivers or tweezers. Before you remove hands, cut a slot in a piece of paper, and slide it over the dial, with the post for the hands in the slot. Try very hard to avoid bending the second hand pivot when you pull up, especially if you are using screwdrivers--Pry evenly on both sides at the same time.

Remove the dial. On a Timex and some other pinlevers, you can leave the hour and minute hands attached, on others you must remove the minute hand. Timex dials are held on by tabs that bend over the movement plate--Bend these as little as possible, and you can usually remove the dial while only bending two tabs. (If you have to remove the dial again, try to remember to bend other tabs the next time)

Other types may have posts that go through the plate with screws either at the top of the movement or along the side. (Adapting these instructions to other watches you probably want to remove the minute hand first, most are built differently than Timex)

On a Timex, I prefer to start with a partially wound watch, if it is fully wound, that's OK.

If you are doing a Timex automatic movement, you'll need to remove the rotor. There are two holes in the rotor to access 2 screws. Once these screws are removed, slide the rotor off sideways. Lifting will damage the cam follower.

The official Timex procedure says to remove the balance, but unless you're used to working with watches I think this step is more trouble than it is worth--Timing is guaranteed to be off by a good bit if you do this. I've had success with no further disassembly during cleaning, I now back the balance screw off a little bit.

For non-Timex watches with a balance cock, I will remove that. Carefully remove the cock and the balance without over-stretching or kinking the hairspring.

A critical difference between Timex and other brands is the mainspring. Timex has a permanent coating on the mainspring that both lubricates and protects from rust. This allows Timex mainsprings to go through a cleaning machine without harm. Other brands lack this coating-if you clean without re-lubricating the mainspring it is almost certain to rust and break in a fairly short time. Because of this, you will also need to disassemble far enough to remove the mainspring on non-Timex. Sometimes this can be done with little disassembly, other times it will require a complete teardown. It is better to leave a non-Timex mainspring uncleaned than to clean it without re-lubricating it.

To remove the Timex balance you'll need to remove the little tapered brass peg where the hairspring attaches to the plate of the watch. Push the thin side with a screwdriver then remove with tweezers

don't lose it.

Put the rest of the movement (as well as the balance if you've removed it) in the cleaner, ans swish it around for 5-10 minutes. If you use ammonia, follow with a Ronsonol rinse. The watch can sit in Ronsonol for a long time, don't go too long in ammonia, it will attack brass or copper parts. If the ammonia starts to turn blue, that is a sign it is attacking, remove the movement immediately and rinse. Dry thoroughly.

If you did not remove the balance, remove the balance screw now. Fill it 3/4 full with watch oil. Fill the cup on the other side of the balance with about the same amount of oil--This will be the hardest part if you didn't remove the balance. Be really careful so you don't damage the hairspring, but you should be able to get just enough clearance to get oil into that cup. Don't get oil on the hairspring--if you do, you will need to clean the oil off somehow, and the easiest method might be to re-clean the whole movement again.

If you did remove the balance, replace it now, and get the balance screw in but not tight. The impulse peg of the balance wheel has to be on the same side as the fork--If you completely removed the balance you can rotate it around where it needs to be before you re-pin the hairspring, otherwise you just have to be careful. Tighten the balance screw so there is no play in the balance, but NO FARTHER!) If you removed the balance, re-pin the hairspring-This is easier if you use a bit of cleaning putty or similar (Handi-Tac, blue-tac or other "thumbtack replacement" putties are decent substitutes for Rodico cleaning putty) to hold the balance in place.

The watch should start here, although the balance might not swing very far without oil. (This assumes the watch was wound when you started) If it doesn't start, make sure the balance screw isn't too tight, and gently turn the balance in both directions--If you feel _any_ resistance, stop--You've probably got the fork and impulse pin on opposite sides, fix that before continuing.

Oil all the pivots on both sides, with the smallest drops of oil you can. Some watchmakers advocate not oiling the fork pivots.

Oil the impulse pin on the balance, and 3 teeth of the escape wheel. Don't oil the other movement gears, but do oil the gears on the outside of the plate and the ones the stem touches. The movement should be running well at this point, with at LEAST 1/2 turn of the balance at each cycle. I'd let it run for at least 20 minutes or so, ideally with a cover so dust doesn't fall on it.

If you did not remove the hands, set the hands to exactly midnight and replace the dial. If you did remove all the hands, make sure the hour and minute wheels are in place, as well as the dial washer. Replace the hour hand, set it to an exact hour, then set the minute hand pointing to 12. Replace the second hand. Temporarily install the stem, set the watch and make sure the hands don't drag or foul on anything. Remove the stem, re-case the movement, re-install the stem.


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Budget Watch Collecting/Modern old American brands

Most of the famous old American brands are now owned by other companies.

Hamilton is now owned by the Swatch group, still makes mechanicals.

Elgin is owned by MZ Berger, makes cheap quartz watches, mostly with Chinese manufacture.

Gruen was an American brand using mostly Swiss parts, is now owned by MZ Berger, mostly cheap quartz. Recently experimented with a Swiss Automatic, but failed.

Waltham is now two separate brands. MZ Berger owns the rights to the name in North America, Waltham International SA owns the brand in the rest of the world, concentrating on Japan. Waltham International was established by the original American Waltham.

Timex is still basically the original company, Norwegian ownership, US headquarters, worldwide production.

Bulova has had several ownership changes, but is still around, although with no US manufacturing.

Accutron--Bulova moved the Accutron name to standard quartz watches, and now makes mechanical Accutrons.


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Business Integration Engine

This is unofficial documentation of Brunswick's Business Integration Engine - BIE, and covers version 6.04. Development from the original team seems to have stopped, and a fork was started. The fork is called BIE-gpl, and a beta version of 6.05 is available for download. BIE is now sold by Redberri.

Introduction
Licensed under the Free Software Foundations' The GNU General Public License, Brunswick WDI's Business Integration Engine is free (as in freedom) software and available at no cost. BIE can help you transform messages and transport messages between applications which does not have these capabilities.

BIE uses a number of free (as in freedom) software components as its foundation. The original contributions to the free software community are the web application Dashboard and the Java client Map Builder.

Dashboard lets you create workflows using drag-and-drop and connectivity in and out of BIE. The Map Builder helps you set up translation from one XML schema to another.

GNU/Linux
tar xfvz bie-linux-6.0.4.tar.gz The result is a new subdirectory called bie-linux-6.0.4. ./install.sh to install BIE. A GUI opens up, just follow the instructions given. admin and the default password is 123qwe
 * Download BIE 6.04 for your platform from Sourceforge.net at http://sourceforge.net/project/showfiles.php?group_id=79291. Choose the zipped archive file bie-linux-6.0.4.tar.gz.
 * Unzip the archive file any way you like. Here is one way using a console window:
 * Change to superuser mode or root with su, enter root's password.
 * Change directory to the new subdirectory and type
 * The install defaults to /usr/local/BIE.
 * Check the box Start BIE
 * The default user is
 * You are done.

Files and sub directories
See /File Tree Structure/.

Setup
http://localhost:5803/
 * Open the BIE Dashboard web application by pointing your web browser to
 * Log in with your user name and password.
 * On the BIE Dashboard Welcome page, click Mail Settings under the System Settings menu, and give your SMTP server and email address, then hit the Save button. You may now test if BIE is able to send you an email by entering your email address in the text field, then hit the Test button, and check your email application for any new email from BIE.

General Settings
Disabled or Enabled from the drop down menu. Disabled is the default setting.
 * Remote Client Management may be set to either

Shut Down
Shut Down
 * Stops All Services by hitting the red button marked

System Log Settings

 * Overall Logging Level may be set to one of the following from the drop down menu
 * ALL
 * DEBUG
 * INFO
 * WARN
 * ERROR
 * FATAL
 * OFF

BufferSize:8192 Class:class org.jboss.logging.appender.DailyRollingFileAppender Filter:null Append:true ErrorHandler:org.apache.log4j.helpers.OnlyOnceErrorHandler@7e80a BufferedIO:false DatePattern:'.'yyyy-MM-dd Name:BIE_DETAILS File:/usr/local/BIE/logs/bie-details.log ImmediateFlush:true Threshold:INFO FirstFilter:null Layout:org.apache.log4j.PatternLayout@113108b Encoding:null
 * Declared Appenders. Full control of the logging behavior can be configured in the /usr/local/BIE/services/jboss/server/default/conf/log4j.xml file. Properties for appender BIE_DETAILS

Listeners
Listeners are BIE's supported methods of getting messages into BIE for processing or out to a recipient when done. Version 6.0.4 supports HTTP/HTTPS, watched directory, FTP, scheduler, POP and FTP directory watcher. You may edit most listeners by hitting the Edit button. To start a listener, hit the Enable button. To stop a listener, hit the Disable button.

Mail Settings
This lets you specify where BIE sends system notifications by email.

Mail Server

 * Mail server host name - type your SMTP server in this field
 * Maximum Notification Message Size (bytes) - the default value is 51200
 * System E-Mail Address - type your email address in this field
 * Use E-Mail Authentication - check this box if your SMTP server requires authentication credentials
 * Authentication User Name - your SMTP user name
 * Authentication Password - your SMTP password

Hit the Save button before testing.

Test Mail Configuration
Run this test to see if your mail server is accessible by BIE
 * Enter E-Mail Address - type your email address here

Hit the Run Test button.

JDBC Drivers
You can add database connections to BIE using JDBC drivers. BIE ships with a MySQL (won't work with new versions of MySql, e.g.:5.0,), and an ODBC driver. You are using something else, you must add the appropriate driver.

Oracle
Oracle driver can be added as follows. 1.	Click on the System --> JDBC Drivers menu option 2.	In the Manage JDBC Connections screen, click on “Register a Driver” link 3.	In the “Register JDBC Driver” screen enter the parameters as follows a)	Driver Name : Oracle       b)	Driver Class Name : oracle.jdbc.driver.OracleDriver c)	Driver Archive : ojdbc.jar        Click on the Register button.  4.	Add a connection to the DUMMY schema as follows, Click on the Add Connection button against the newly registered              driver.  5.	In the “Choose JDBC Driver” screen enter the values         a)	Select Driver :  Oracle (The driver that we added in the previous step) b)	Connection URL : jdbc:oracle:thin:@::DUMMY       Click on the continue button.  6.    Set the connection properties as         a)  Connection Name: DUMMY b) URL: jdbc:oracle:thin:@::DUMMY        c)  Username: username d) Password: password        Click on the “Save” button.  7.	In the “Manage JDBC Connections”, we can find the newly added connection listed.  8.    Click on the Test button next to the newly added connection.

MySQL
The MySQL JDBC driver that ships with BIE 6.04 is version 2.014, which does not appear to work with MySQL version 4.1.7 or newer. The latest stable MySQL JDBC driver is version 3.1.13, which may be downloaded from http://www.mysql.com/products/connector/j/ The latest driver solves the issue of connecting BIE to a MySQL on the same server, but you may need to add localhost.localdomain in the Host column to your User table in the MySQL database.

PostgreSQL
The PostgreSQL driver may be downloaded from http://jdbc.postgresql.org/download.html.

HSQLDB
BIE uses an internal Hypersonic database, now called HSQLDB, that contains configuration, state, and audit information. See

Other JDBC drivers
Chui's counterpoint lists a number of JDBC driver and JDBC URLs.

Some drivers like DB2 require more than one jar file. If so, just create a dummy driver for each extra jar file as a way to upload it. You may need to restart the BIE service before it notices the new jar files.

LDAP Connections
Lightweight Directory Access Protocol or LDAP is a protocol for querying directories. Here you can add your companies LDAP directory service.

Workflow
A common mistake/issue when trying to run a workflow, is not provide a start message. The default config for a newly added workflow is to receive InputMessage, with the message format as StandardXML. So, to start a worflow, you've got to provide at least a minimum xml tag, e.g.:  Changing the format to StandardRaw will solve this issue.

Message Formats
BIE only understands XML, so you must express any input or output as XML schemas before you can use BIE. If you receive a file containing Comma Separated Values - CSV for short - BIE can help you generate the necessary schema.

Map Builder - moving data between applications with XML Schemas
XML Schemas express shared vocabularies and allow machines to carry out rules made by people. They provide a means for defining the structure, content and semantics of XML documents.

Map Builder is a Java application, which lets you load an input schema and output schema, and then use drag and drop to establish links between matching fields from the input schema to the output schema. Once a link is established, you may add processing instructions to the link, e.g. mathematical, logic, string operations and so on.

The map is then saved as an XSLT transformation file, meaning it shows how input documents are converted to output documents.

Testing maps
IMPORTANT: Don't use a file with Comma Separated Values (CSV) when testing your map! A error box with the following message will appear:

Error An unexpected error occurred. Source: Content is not allowed in prolog.

Hit the OK button to close the box.

CORRECT WAY: Use an XML version of the CSV file. The Dashboard can be used to generate the correct parsed XML output for a given message format. Copy and paste this parsed output to a file, and use this file for testing your map in Map Builder. See tutorial below for details.

Tutorials
Some assumptions are made in the following tutorials:
 * You have read the entire tutorial before proceeding, and understand that you follow the instructions at your own risk.
 * You have administrator or root rights to the server where BIE is installed.
 * BIE has been started. A standard installation on GNU/Linux can be started this way

/usr/local/BIE/bin/start.sh

 * You have logged into Dashboard. A standard installation regardless of platform makes the Dashboard available from the server to your browser at

http://localhost:5803/

given the user name

admin

and the password

123qwe

 * You have started the Map Builder. A standard installation on GNU/Linux can be started this way

/usr/local/BIE/bin/map.sh

 * You have a text editor available.

Lesson 1 - from CSV to XML
MyName,MyAddress,MyPhone,MyCountry Joe Schmoe,Anywhere Street Number 1,123-456-789,Anyplace on Earth /usr/local/BIE/translation/data Lesson1 Lesson1 /usr/local/BIE/translation/data/Lesson1.CSV
 * Open your text editor
 * Enter or copy and paste the following text, making sure there is a new line character between them (hit the Enter or Return key at the end of line one)
 * Save the file as Lesson1.CSV to
 * Open the Dashboard, select Workflow from the top menu, then select the menu item Message Formats
 * Under the heading Configurations, select type Delimited from the drop-down menu, then hit the "add new" button.
 * In the Name field write
 * Set the Process Header radio button to On
 * Change the Root tag to
 * Hit the save button.
 * In the Format column under Configurations, you will now see a link named Lesson1 - hit it.
 * A new form is now available, called Format Testing / Schema Generation.
 * In the "Select a local file" field, enter or select through the browse button the address to Lesson1.CSV
 * Hit the "Run Formatter/Generator" button.
 * A new three part form is now available:
 * Generated schema. Give the name

Lesson1.xsd in the text field. DON'T HIT THE "Save to Server" button just yet.
 * Parsed Ouput - a BIE typo, should be Parsed Output. Select the parsed XML output, copy, and paste into a new file in your text editor. Save the file as

Lesson1.xml
 * NOW you can hit the "Save to Server" button. We did it this way to avoid back-button browser problems.

Lesson1.xsd as your source schema, then hit the Next button. Lesson1.xsd as your target schema. Yes, it's the same one, but for the purposes of this lesson it will do. Hit the Next button. Lesson12Lesson1.xml by hitting the Finish button. Lesson1.xml Lesson1_transformed.xml and hit the Save button. Lesson1_transformed.xml You should see that the data from the source fields have been accurately mapped to destination fields. Lesson1.xml as the source file and save the result as Lesson1_transformed_again.xml Lesson1_transformed_again.xml in your text editor. You should see that Joe Schmoe is now in the MyAddress field, and his address has become his name.
 * Open Map Builder, and hit the "Create a new map" button in the top left corner. The steps is outlined to the left, and you can you select
 * Select Lesson1 as the source schema's root element, and hit the Next button
 * Select the suggested File Name for the base path for source includes/imports by hitting the Next button
 * Select
 * Select Lesson1 as the target schema's root element, and hit the Next button.
 * Select the suggested File Name for the base path for source includes/imports by hitting the Next button.
 * Save the map file to the map folder with the file name
 * The map is loaded with the source schema's fields on the left, and the destination schema's fields on the right.
 * Click the source schema's row icon and hold down the mouse button while moving it to the destination schema's row icon before you let the mouse button go. You should now a blue link between the two schemas.
 * Repeat the linking process - MyName to MyName, MyAddress to MyAddress, MyPhone to MyPhone, MyCountry to MyCountry.
 * Hit the Compile XSLT button from the tool bar.
 * Hit the Test XSLT transformation button, and select
 * The Save result dialog opens, change the file name to
 * Open your text editor, and load the file
 * Right-click the MyName field in the source schema and select Unlink. Do the same with MyAddress.
 * Now link the source field MyName to the destination field MyAddress. Link the source field MyAddress to the destination field MyName.
 * Save the new map.
 * Compile the new map.
 * Test XSLT transformation using
 * Open

Lesson1 is now over. You should try BIE to find what works or not. Come back here and create new lessons. :-)

Lesson 2 - creating a workflow
In Lesson 1 you learned how to create a map between one XML Schema to another in Map Builder, and to test the transformation. The point of BIE is to automate these kinds of mappings, and that is what we are going to do in this lesson. This time we will be mostly working in the Dashboard, creating a workflow.

To be continued... In the interim, please look at the JonesPubPO workflow.

Lesson X - setting up EDI of encrypted documents
An idea for a future lesson:

Health professionals exchange sensitive patient information electronically using encrypted XML Schemas. Referrals and reports are transported by the thousands every single day of the year. This lesson will describe the use of GNU Privacy Guard, perhaps Idealx X.509 Certificate Authority and BIE for this purpose.

References to BIE-gpl

 * http://www.bie-gpl.org/
 * http://sourceforge.net/projects/bie-gpl/

title: Business Integration Engine


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Truth Table

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I set this up to be a simple Truth Table Template for the Digital Circuits Wikibook. --Whiteknight 18:05, 10 October 2005 (UTC)


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This is going to be a generic page header for the Digital Circuits wikibook, and possibly others. --Whiteknight 18:15, 10 October 2005 (UTC)

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Digital Circuits/Contributors

This is a page where we can list notes for other contributors, and where contributors can sign their name, and get some recognition for working on the Digital Circuits Wikibook.

Templates
Here is a current list of templates in use in this book:

 * Template:Digital Circuits Page
 * Template:Digital Circuits Truth Table
 * Template:Digital Circuits Stub

Contributors
--Whiteknight 18:20, 10 October 2005 (UTC)

--mhasskam 19:55, 27 October 2005 (UTC)

--HL-SDK 13:14, 1 October 2006 (UTC)

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''This section of the  wikibook is a stub. You can help by expanding this section. If you add something, list yourself as a Contributor.'' :This template adds page to /Stubs.

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I created this template to handle page stubs in the Digital Circuits wikibook. --Whiteknight 18:24, 10 October 2005 (UTC)

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Adventist Youth Honors Answer Book/Vocational/Computer (General Conference)

1. Write 200 words or give a three-minute oral report about the history of computers.

 * 1936: The first programmable computer is the Z1 originally created by Germany's Konrad Zuse in his parents living room in 1936 to 1938 is considered to be the first electrical binary programmable computer. The first digital computer, the ABC started being developed by Professor John Vincent Atanasoff and graduate student Cliff Berry in 1937.
 * 1943: Then followed the ENIAC, then the EDSAC as the first stored program electronic computer.
 * 1954: Toshiba introduces its first computer, the TAC digital computer.
 * 1958: NEC builds its first computer, the NEAC 1101
 * 1960: Digital Equipment Corporation released its first of many PDP computers, the PDP-1
 * 1966: Hewlett Packard released its first general computer, the HP - 2115
 * 1974: XEROX ALTO is considered to be the first workstation.
 * 1975: Ed Roberts coined the term personal computer when he introduced the Altair 8800, although the first personal computer is considered to be the Kenback-1.
 * 1981: IBM introduced the IBM PC.
 * 1983: Compaq released its first computer and the first 100% IBM compatible computer, the Compaq Portable
 * 1984: IBM PCD later released the IBM portable.
 * 1985: Dell introduced its first computer, the Turbo PC
 * 1994: IBM introduces the IBM thinkPad 775CD, the first notebook with an integrated CD-ROM. The World Wide Web Consortium (W3C) was founded.
 * 1995: Java is introduced.
 * 1998: Google is founded
 * 2001: Windows XP & Mac OS X are released. Palm, Inc. introduced the Kyocera 6035, the first smartphone in the United States.
 * 2010: iPad is released (first commercially successful tablet computer).

Hardware
Hardware is any physical portion of a computing device, such as memory, motherboard etc

//These are tangible parts of the computer system//

Software
Software is a term describing a set of instructions that control the operation of a computer. Software can be easily changed and updated. Once it has been created, it can be reproduced very cheaply. This is because software is not something that can be touched or held in a person's hand. The media on which the software is written can be touched, but the media does not generally look any different after the software is written to it. Software can be stored on many types of media, and can in fact be distributed without the use of a storage medium (other than its final storage destination on a computer's hard drive).

Floppy Disk
A floppy disk is a removable storage media for computers. It consists of a plastic disk coated with a magnetic material encased in a plastic sheath. Data can be stored on them by changing the magnetic properties of very tiny areas on the disk. The data can be read back by detecting these magnetic fields. Floppy disks are no longer in widespread use, having been replaced by writable CD ROMs, flash drives, and computer networks. In their heyday, they were used for distributing software, exchanging data between computers, data storage, and for data archival.

Mainframe
A mainframe is a large, powerful computer shared by many users. It is generally located someplace in a building separate from where its users are. The users of a mainframe connect to it through a terminal consisting of a keyboard and a monitor. A mainframe can be connected to many terminals - and therefore - many users at a time. The terminals are connected to the mainframe by a network. Some terminals are also equipped with a mouse and speakers. Full access to a mainframe is usually reserved for the system administrator who is responsible for installing software, performing maintenance, and creating user accounts. Regular mainframe users generally do not have privileges to install new software or alter files belonging to other users.

Desktop Computer
A desktop computer is a small computer system that is dedicated to a small number of users. This type of computer is often found in homes and offices and is capable of running stand-alone (that is, in the absence of another computer such as a mainframe). Desktop computers do not take up a lot of space, but they are not easy to move from one location to another (like a laptop).

Laptop Computer
A laptop computer is a small, portable computer. They are generally not as powerful as desktop computers selling for the same amount. Laptops come in a "clamshell" design, such that the video display can be folded down over the keyboard when the computer is not in use, or when it is transported. The circuitry is located beneath the keyboard. Laptops are designed to maximize battery life and minimize size and weight.

ROM
ROM is an acronym that stands for Read Only Memory. This is a form of computer memory whose contents cannot be altered except when it is manufactured. It is typically used to store a computer's boot program. The boot program is the first program to execute when a computer is turned on, and it typically loads an operating system into main (writable) memory from some other storage media (such as a harddrive, cd rom drive, or network).

Alphanumeric
The set of all letters and numbers. An alphanumeric value is any string made up of only letters and numbers. For instance, "a12bgj", "1234", and "ABCD" are all alphanumeric, whereas "aB$4" is not (it contains the '$' symbol which is neither a letter nor a number).

Circuit Board
A circuit board is a stiff sheet of material upon which various components of a circuit are soldered. It supplies the connections between the components as well as a platform on which they are mounted.

Cursor
The cursor is a visual indicator on a computer display. It shows where on the display the next keyboard entry will be made. In a graphical system, the cursor may be moved around the screen with a mouse. In a text system, the cursor may be moved around using the arrow keys on the keyboard.

Port
A port is an external connection on a computer. It provides a connection to an external device such as a mouse, keyboard, printer, external modem, camera, or other device.

Program
A program is a series of computer instructions that when executed performs a predetermined task.

DOS or OS
OS stands for "Operating System" and DOS stands for "Disk Operating System." An operating system is a program that coordinates the rest of the computer. It allows other programs to run and generally provides an easy mechanism for other programs to access various hardware devices on the computer. A Disk operating system is an operating system that is loaded from a hard drive or floppy drive.

CD Rom
A CD Rom is a type of computer storage medium. "CD ROM" stands for "Compact Disc, Read Only Memory". These devices were originally developed for storing music, but were pressed into service for storing all kinds of computer data after their initial introduction. A typical CD Rom can store approximately 650 megabytes of data. The data on a CD Rom is read from the disc by a laser beam in a CD Rom drive.

3. What are the proper handling and storage techniques for disks?
Disks should be stored away from devices that create magnetic fields such as speakers and video monitors. They should be kept free from dust and moisture, and should not be bent or folded. Care should be taken to not scratch compact discs.

System Unit or Central Processing Unit
The system unit is the part of a computer that contains the microprocessor, memory, and hardrive. It is the "main" component of a desktop computer system or a mainframe. All other devices (such as the monitor, keyboard, mouse, printer, etc.) plug into it. It is sometimes also called the "Central Processing Unit," although that term is also used to describe the microprocessor.

Printer
A computer printer is a device which records computer output to paper. Printers come in many forms as described in a later section.

Disk Drive
A disk drive is a device which stores data onto a platter (the disc) which has been coated with a magnetically sensitive material. Data on a disk drive can be stored for long periods of time even when the device is powered off. There are two types of disk drives: hard drives and floppy drives.

Letter Quality
From Wikipedia, the free encyclopedia.

A letter-quality printer was a form of computer impact printer that was able to print with the quality typically expected from a business typewriter such as an IBM Selectric.

Over time, several different technologies were used including automating ordinary typebar typewriter mechanisms (such as the Friden Flexowriter), automating IBM Selectric mechanisms (such as the IBM 2741 terminal), and, finally, the daisy wheel printer. The Selectric-based and daisy wheel printers offered the additional advantage that the typeface was readily changeable by the user to accommodate varying needs.

Because of its low cost, the daisy wheel printer became the most successful of the three types. Most letter quality printers were available either as complete computer terminals with keyboards or as print-only devices.

Nowadays, printers using non-impact printing (for example laser printers, inkjet printers, and other similar means) have replaced traditional letter-quality printers in most applications.

Dot Matrix
From Wikipedia, the free encyclopedia.

A dot matrix printer or impact matrix printer refers to a type of computer printer with a print head that runs back and forth on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like a typewriter. Unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced. Because the printing involves mechanical pressure, these printers can create carbon copies and carbonless copies.

Each dot is produced by a tiny metal rod, also called a "wire" or "pin", which uses the power of a tiny electromagnet or solenoid to drive it forward, either directly or through small levers.

In the 1970s and 1980s, dot matrix impact printers were generally considered the best combination of expense and versatility, and until the 1990s they were by far the most common form of printer used with personal computers.

Plotter
From Wikipedia, the free encyclopedia.

Plotters print their output by moving a pen across the surface of a piece of paper. This means that plotters are restricted to line art, rather than raster graphics as with other printers. They can draw complex line art, including text, but do so very slowly because of the mechanical movement of the pens. (Plotters are incapable of creating a solid region of color; but can hatch an area by drawing a number of close, regular lines.)

Plotters are used primarily in technical drawing and CAD applications, where they have the advantage of working on very large paper sizes while maintaining high resolution. Another use has been found by replacing the pen with a cutter, and in this form plotters can be found in many garment and sign shops.

Thermal
From Wikipedia, the free encyclopedia.

A thermal printer (or direct thermal printer) produces a printed image by selectively heating coated paper when the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image. Two-color direct thermal printers are capable of printing both black and an additional color (often red), by applying heat at two different temperatures.

Thermal printers are often faster and quieter than dot matrix printers. They are also more economical than other types of printers since their only consumable is the paper itself. Possible applications of thermal printers include filling station pumps, information kiosks, and cash register systems. Thermal printers are useful anywhere low cost is more important than high quality.

== 6. Show or describe how to protect a computer system from dust, dirt, static electricity, power surges and outages, or other potentially dangerous factors that could hamper or hurt a computer system. ==

Dirt and Dust
One way to protect a computer from dust and dirt is to locate it in an area where there is little dust or no dirt at all. A computer should be elevated off the floor. It can be stored on a desk, or even on top of a block of wood - getting it even an inch or two off the floor will prevent it from accumulating much dust.

Static Electricity
Computer circuitry can be damaged by static electricity. One generally doesn't have to worry about that too much as long as the cover of the computer is on. However, when installing a new card in a PC, adding an internal hard drive, or performing any maintenance that requires one to remove the cover, care must be taken to discharge static electricity. This can best be done by wearing an anti-static wrist strap while handling components. One end of the strap is worn around the wrist, and the other is connected to the same electrical ground that the computer is connected to. However, not all computer users own an anti-static strap. In those cases, other precautions can be taken to avoid static discharge into the electronic components. One way this his can be done is by touching the metal frame of the computer before touching any of the sensitive electronic components inside.

When installing new components into a computer, the component should be left in its protective packaging until it is ready to be inserted into the computer. Touch the package first, then remove the component. If not wearing a wrist strap, touch the computer's frame next, and then install the component.

Power Surges and Outages
Computers should be protected from power surges by plugging them into a surge protector. These can be purchased at computer stores, office supply stores, or even hardware stores. A surge protector will not protect a computer from a power outage though. For that, an uninterruptible power supply (or UPS) can be used. An UPS is a device that will continue to supply electrical power to the computer for a short while after the power fails. Some UPS's can supply power for hours, while others can supply power for only a few minutes - long enough to shut the computer down to prevent loss of data. A good UPS can tell the computer when it has lost its primary source of power and instruct the computer to shut itself down when backup power is nearly spent.

Other Dangers
Be careful about eating or drinking around a computer. It is easy to drop food crumbs into a computer keyboard, and more than one computer has been destroyed by a spilled drink. Don't set a drink down next to a computer, or worse yet, on a shelf or desk above the computer. It is best to keep these things away from the computer, but if that cannot be avoided, they should be placed in a position such that a spill is unlikely to reach the computer.

Computers should be protected from other forms of liquid as well - if the roof begins to leak, unplug the computer and move it to a dry area.

Do not drop a computer. Some of the components are easily damaged by the shock, especially those components with moving parts such as disk drives. A sharp jolt to a computer may also dislodge components, bend connectors, or in severe cases, break solder joints.

Operate a computer in a cool environment. Excessive heat can damage a computer or cause it to lose stability. Programs can misbehave, and memories and other devices can fail in high temperature environments.

When transporting a computer, pack it appropriately. Laptops should be carried in special bags made for that purpose. Desktop systems should be boxed in their original packaging when possible. If transporting a monitor by car, place the screen against the back of the seat. The front of the screen is the heaviest side of the monitor, so placing it against the back of the seat will make it less likely to slide around, as well as protect the screen from other objects that might fly around (such as a keyboard!) during a sudden stop.

7. Name at least four input devices for computers

 * Keyboard
 * Mouse
 * Digital Camera
 * Scanner
 * Microphone
 * Network Interface Card
 * Modem
 * Flash Drive
 * Floppy Drive
 * CD Rom Drive
 * Frame Grabber

8. What does it mean to back up a disk or a file? Why is it important?
Backing up a disk or a file means making another copy of it. Although computers are highly reliable machines, they are not perfect. Floppy discs can be lost or damaged. All hard drives will eventually fail. When this happens, it can be difficult, expensive, and even impossible to recover the data that was stored on them. For this reason, all important data should be backup up. This can be accomplished by copying it to another computer, burning the data onto a CD Rom, copying it to a floppy drive, a second hard drive, or a flash drive. In some cases, a file can be backed up by emailing it to oneself so that the data is stored on an email server, although in this case, care must be taken that the data really is stored on a different computer.

Guard Against Malicious Software
There are many things a computer user can do to keep the computer running smoothly. The most important is to prevent the computer from getting infected with a virus, a worm, or spyware. Many places on the internet will entice the user to download malicious software, so computer users should be especially careful. An infected computer system can get so bogged down with junk programs that it is virtually inoperable. Sometimes the only way to "cure" it is by performing a complete reinstall of all the programs and the operating system. Anti-virus and firewall software can be an effective means to protect a computer from malicious software.

Security Updates
Software vendors often issue security updates to the software they provide. Often, a vulnerability in a program is discovered, and the software vendor fixes the problem an issues an update. These updates should be applied as soon as possible (or better - automatically) because there are other people in the world who are watching for these updates with evil intent. As soon as the security update is announced, these individuals will attempt to develop a program to exploit the vulnerability. These programs, once they have breached a computer, usually put the computer to work looking for other vulnerable computers, and thus, the infection spreads. Do not believe that because you are an anonymous person, your computer will not be affected. These programs do not care who you are - they are only concerned that your computer is vulnerable. Sometimes these programs only attempt to spread themselves around. Other times, they can install themselves invisibly, log the user's keystrokes, and forward them to the author of the malicious program. In these cases, the program is looking for sensitive information about you: bank account numbers, social security numbers, etc. Keep your computer software secured and up to date!

Defragment the Hard Drive
Another thing a computer user can do to tune the computer's performance is to defragment the hard drive. This operation puts all the data from each file sequentially on the hard drive, so it can be accessed more quickly. A computer can store data from single file in locations physically scattered all over the drive. The data is still presented to the computer as if it were stored sequentially - it just takes it a lot longer to collect all that information.

Dust Bunnies Inside
A computer should be dusted any time it is opened. Dust can be blown out using a can of compressed air. Care should be taken when this operation is performed - the dust can easily fly back into the maintainers face and get into the eyes. Be careful that all fans are operating properly after they are cleaned. Cooling fans often fail immediately after they are cleaned. One should also check under the cooling fan to make sure the fins of the heat sink are clean. If the heatsink is plugged up with dirt and grime the processor will overheat.

10. Successfully boot, load (install), and use a prepared software program for use in a computer system. (No computer games.)
There are many programs that can be used to meet this requirement. Some programs can be purchased at a store, and others can be downloaded for free (legally!) from the Internet. Some excellent programs that can be downloaded for free include OpenOffice (an Office suite with a word processor, spread sheet, presentation program, and drawing package), Firefox (a web browser), Thunderbird (an email program), and The Gimp (a photo/image editing program). All of these programs are of excellent quality and compare very favorably to their commercial counterparts. Best of all, they are FREE.

11. Tell several ways an individual or family could use a personal computer other than for games.
Tracking finances, staying in contact with other family members, record keeping, making documents, producing web pages, connecting to the Internet, researching a school (or work) assignment, getting directions, finding lost friends, downloading pathfinder honors requirements and answers, and many, many more!

About the Author
| /Completed Honors


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Using Firefox/Developers

Extension Development
The most comprehensive site for Extension development is at the Mozillazine Knowledge Base found here. Other helpful tools include the DOM Inspector included in Firefox and the JavaScript console.

Firefox is especially developer-friendly. It allows even the most casual web developer to crib useful HTML techniques from most any website they visit, and offers a host of other features for more serious users.

Source viewing
Perhaps the most-used development feature is the ability to highlight images and text in any website, and choose to view source from a drop-down menu. When this feature is used, Firefox displays the HTML source that was used to generate the highlighted content.

For instance, highlighting the above paragraph and section heading, right clicking, and choosing "Vi e w Selection Source", will display the following in a new window:

 Source viewing Perhaps the most-used development feature is the ability to highlight images and text in any website, and choose "View selection source" from the drop-down menu. Doing this will bring up a pop-up window, with the HTML source that was used to generate the highlighted content.

Combining this technique with a good markup language reference source, such as the Wikibook HTML Programming, will allow you to learn from every new website you visit.

Firefox/Outils aux développeurs Mozilla Firefox/Sviluppatori

title: Using Firefox/Developers


text:
Radiation Oncology/CNS/Acoustic neuroma

Epidemiology
The overall incidence of symptomatic acoustic neuromas is 1/100,000 persons, however, autopsy results have shown that subclinical acoustic neuromas are present in up to 1% of people. Acoustic neuromas account for ~8% of intracranial tumors and 80-90% of CPA tumors. Most people with symptomatic acoustic neuromas will present between the ages of 30 and 50. They are almost always unilateral; bilateral acoustic neuromas are limited to patients with NF-2.

Risk Factors

 * Acoustic trauma: OR of 2.2 if 10 years exposure to extremely loud noise, OR of 13.1 if 20 or more years of exposure.
 * Parathyroid adenoma: OR of 3.4 for acoustic neuromas.
 * NF-2: Accounts for 10% of patients with acoustic neuroma, typically bilateral. Recall that NF2 gene is a tumor suppressor gene on chromosome 22 that encodes a membrane cytoskeletal protein called merlin or schwannomin that appears to be involved in actin-cytoskeleton organization.  NF2 associated with bilateral ANs, gliomas, meningiomas, cataracts, and neurofibromas.

Pathology
Acoustic neuromas arise from the Schwann cell perineural elements of the affected nerve and occur with equal frequency on the superior and inferior branches of the vestibular nerve (rarely affect the cochlear portion of CN VIII). They arise at the junction of the central myelin produced by glial cells and peripheral myelin produced by Schwann cells (Obersteiner-Redlich zone). On light microscopy one will see zones of alternately dense and sparse cellularity called Antoni A and B areas, respectively. Acoustic neuromas will also stain positive for the S100 protein.

Natural History
The natural history of acoustic neuromas is variable. The average growth rate is 1.9mm/year. 40% of tumors overall (higher for smaller tumors) will show no growth or even shrinkage on serial images. However, there is no predictive relation between growth rate and size of tumor at presentation.

Clinical Presentation
The symptoms involved with acoustic neuroma are due to cranial nerve involvement and tumor progression.
 * Acoustic nerve: Symptomatic involvement in 95% of patients, major symptoms being hearing loss and tinnitus. Hearing loss present in 95%, but only about 66% were actually aware of this deficit.  The hearing loss is usually chronic (over years).  Tinnitus is present in 63% of patients.
 * Vestibular nerve: Involved in 61% of patients and manifests as mild to moderate unsteadiness while walking. True spinning vertigo is uncommon due to the slow growing nature of these tumors.
 * Trigeminal nerve: Disturbance occurs in 17% of patients with symptoms such as facial numbness, hypesthesia, and pain. These symptoms usually occur after hearing loss is present for more than two years, and vestibular symptoms for more than one year.
 * Facial nerve: Involved in 6% of patients. Seen as facial paresis and taste disturbances.
 * Posterior fossa: Compression on the cerebellum or brainstem results in ataxia.  May also see serious complications such as brainstem compression, cerebellar tonsillar herniation, hydrocephalus, and death.

Work-up

 * Physical Exam:
 * Confirm sensorineural hearing loss with Rinne test (tuning fork on mastoid bone, AC>BC) and Weber test (vibratory sound louder on the “good” side)
 * Also check for other CN deficits (absent corneal reflex, facial twitching, hypesthesia)
 * Audiometry:
 * The best initial screening test
 * Typically shows asymmetric SHL, usually more prominent in the higher frequencies. Functional hearing typically described as <50 dB and >50% speech discrimination
 * Hearing loss does not necessarily correlate with tumor size.
 * Brainstem auditory evoked potentials: Delay in conduction time on the affected side.
 * Imaging: MRI with gadolinium can detect tumors as small as 1-2mm. Seen as an enhancing lesion “ice cream cone” in the region of internal acoustic canal or a “dumbbell” extending into the foramen magnum.

Treatment
The three treatment options for acoustic neuroma are surgery, radiation therapy, and observation.

Surgery
Typically performed by an otologist and a neurosurgeon. The learning curve is very steep, on the order of 20-60 cases. There are three surgical approaches used in the removal of acoustic neuromas. Results: Anatomic preservation of the facial nerve is achieved in 93% of patients and of the cochlear nerve in 68%. Hearing preservation rate for surgery is 47%. Complications of surgery: Death (1%), hemiparesis (1%), CN palsey (5%), hematomas (2.2%), CSF fistulas (9.2%), hydrocephalus (2.3%), bacterial meningitis (1.2%), wound revisions (1.1%). (Samii, Neurosurgery 1997 Jan;40(1):11-21)
 * Retromastoid suboccipital: An incision is made behind the ear and the mastoid bone and some inner ear structures are removed. Advantages to this approach include decreased risk of facial nerve damage and ability to attempt hearing preservation.  A disadvantage is that using this approach, if the tumor extends distally into the IAC, complete removal may not be possible.
 * Middle fossa: This approach involves an incision just anterior to the ear with removal of the underlying bone to expose the area of interest. Hearing preservation is attempted with this approach, but depending on location of the tumor complete removal may not be feasible.
 * Translabyrinthine: This approach goes directly through the inner ear and invariably sacrifices hearing.

Radiosurgery
GKS--Patient’s head is fixed in MRI compatible Leksell stereotactic frame and 1-1.5mm slice MRI is obtained. Prescribe dose of 12.5-13.0 Gy to the 50% isodose line. TV defined as macroscopic tumor seen on MRI/CT. Evaluate dose fall-off to cochlea and brain stem. Tumor control rate (97%), Normal facial function (>99%), Trigeminal function (97%), Hearing preservation (up to 77%). (Lunsford, J Neurosurg 2005 Jan;102 Suppl:195-9)

Proton Beam Radiosurgery--Now only used for pts with non-serviceable hearing and tumors <2.0cm. Use 3 fiducial markers in the outer table of the cranium, as well as placement of head in a stereotactic frame. A 3D CT based planning system is used. 160 MeV proton beam is used to administer 3 converging beams to a max dose of 13 cobalt Gray equivalents to TV. Evaluate dose fall-off to brainstem and cochlea. Excellent tumor control (95%) and preservation of CNs V (89%) and VII (91%) Hearing preservation: 33%. (Weber, Neurosurgery 2003 Sep;53(3):577-86)

Fractionated stereotactic radiotherapy--Patient’s head is immobilized in a mask and linear accelerator is used to apply the radiation. Dose: 50-55 Gy in 25-30 fractions to the 80% isodose line. The data for FSR has shown excellent tumor control, preservation of hearing/CN function, and reduced treatment related toxicity. (Combs, IJROBP 2005 Sep 1; 63 (1):75-81)

Observation
In certain cases it may be feasible to observe the patient and his/her VS with MRI scans every 6-12 months. Problems with this approach include ongoing hearing loss, and possible mass effects with large tumors.

External Beam RT

 * Thomas Jefferson; 2009 PMID 19042095 -- "Toward dose optimization for fractionated stereotactic radiotherapy for acoustic neuromas: comparison of two dose cohorts." (Andrews DW, Int J Radiat Oncol Biol Phys. 2009 Jun 1;74(2):419-26. Epub 2008 Nov 29.)
 * Retrospective. 89 patients. Two dose levels: 50.4 Gy vs 46.8 Gy. Median F/U 4.4 and 5.4 years
 * Outcome: Tumor control 100% both groups.
 * Toxicity: Raw 3-year hearing preservation 46.8 Gy 79% vs. 50.4 Gy 68% (SS). Pure tone hearing better in low-dose cohort 46.8 Gy 33db vs. 50.4 Gy 40 db (SS). Actuarial hearing preservation rate significantly longer for low-dose group 3.2 years vs. 1.5 years (SS). Predictors for hearing dose cohort and pretreatment hearing class
 * Conclusion: Lower dose of 46.8 Gy had 100% local control with better hearing preservation rate

 * Harvard; 2005 (1992-2001) PMID 15987541 -- "Stereotactic radiotherapy for vestibular schwannomas: favorable outcome with minimal toxicity." (Chan AW, Neurosurgery. 2005 Jul;57(1):60-70; discussion 60-70.)
 * Retrospective. 70 patients (new 47%, progressive after observation 31%, postop 3%, recurrent 19%), NF2 in 11 patients. Treated with linac SRT. Median dose 54/30 to 95% isodose. Median tumor volume 2.4 cm3. Median F/U 3.8 years
 * Outcome: 3-year LC 100%, 5-year LC 98%. Freedom from resection 98% and 92%. Initial tumor volume predictive of resection: 5-year FFR if <8 cm3 97% vs. >8 cm3 47%. No difference due to NF2 status
 * Toxicity: 3-year facial nerve 99%, trigeminal nerve 96%. Prior surgery predictive of TN toxicity (86% vs. 98%)
 * Conclusion: Conventionally fractionated SRT results in very favorable outcome

Comparison of radiosurgery and surgery

 * France, 2002 - PMID 12450031 — "Functional outcome after gamma knife surgery or microsurgery for vestibular schwannomas." Regis et al.,J Neurosurgery. 2002 Nov;97(5):1091-100.
 * Non-randomized prospective series using pre- and post-operative questionnaires to evaluate functional outcomes after GKS or microsurgery. The minimum follow-up was 3 years, the GKS group had 97 patients and the microsurgery group had 110 patients.  Outcomes in table below:

 * Baylor, 2002 (1993-2000) - PMID 12459364 — "Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery." Karpinos M et al. Int J Radiat Oncol Biol Phys. 2002 Dec 1;54(5):1410-21.
 * Retrospective. 75 pts with Gamma Knife, 25 with microsurgery.
 * No difference in tumor control. RS more effective in: preservation of measurable hearing (57% vs 14%). Microsurgery had higher rate of: facial neuropathy (35%/6%) and trigeminal neuropathy (22%/12%). Also no difference in: serviceable hearing, tinnitus, imbalance, dysarthria, dysphagia, and headache. Longer hospital stay and more perioperative complications (47% vs 4%) for microsurgery.

Comparison of SRS and FSRT

 * Amsterdam; 2003 PMID 12873685 -- "Single-fraction vs. fractionated linac-based stereotactic radiosurgery for vestibular schwannoma: a single-institution study." (Meijer OW, IJROBP. 2003 Aug 1;56(5):1390-6). 129 patients with ANs from 1992-1999 were prospectively selected for SRS or FSRT based on whether or not they had teeth.  All treatments were linac based.  The dentate patients received FSRT (20Gy/5fx and 25Gy/5fx) and the edentate patients received SRS (10Gy and 12.5Gy).  Mean follow-up was 33 months.  Results in table below.
 * Conclusion: Comparable rate of tumor control and preservation of hearing, CN V, and CN VII.

 * Thomas Jefferson; 2001 (1994-2000) PMID 11483338 -- "Stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of acoustic schwannomas: comparative observations of 125 patients treated at one institution." (Andrews, IJROBP. 2001 Aug 1;50(5):1265-78).
 * Retrospective. 122 patients (GKS 69, fractionated 52). GKS dose 12 Gy, fractionated dose 50/25. Mean F/U 2.3 years
 * Outcome: tumor control SRS 98% vs. FSRT 97% (NS)
 * Toxicity: CN V preservation 95% vs. 93% (NS), CN VII preservation 98% vs. 98% (NS); functional hearing 33% vs. 81% (SS)
 * Conclusions: Comparable rates of tumor control and CN preservation, improvement in serviceable hearing

Proton Therapy

 * Harvard; 2003 (1992-2000) PMID 12943574 -- "Proton beam radiosurgery for vestibular schwannoma: tumor control and cranial nerve toxicity." (Weber DC, Neurosurgery. 2003 Sep;53(3):577-86; discussion 586-8.)
 * Retrospective. 88 patients, proton SRS. Median volume 1.4 cm3. Prior surgery 17%. Facial nerve function normal 90%, good/excellent hearing 9%, serviceable hearing 15%. Median dose 12 CGE (10-18 CGE) prescribed to median 70% isodose line. Median F/U 3.2 years
 * Outcome: 5-year LC 94%, radiological reduction in 95%
 * Toxicity: In GR Grade 1-2, 33% retained servicable (GR Grade 2) hearing. 5-year normal facial nerve 91% and trigeminal nerve 89%. Facial neuropathy predicted by prescribed dose, maximum dose, and inhomogeneity
 * Conclusion: Proton beam SRS effective treatment, reduced prescribed dose associated with decrease in facial neuropathy

 * Loma Linda; 2002 (1991-1999) PMID 11844261 -- "Fractionated proton beam radiotherapy for acoustic neuroma." (Bush DA, Neurosurgery. 2002 Feb;50(2):270-3; discussion 273-5.)
 * Retrospective. 31 ANs in 30 patients. Mean tumor volume 4.3 cm3. If useful hearing, 54 CGE, if no hearing 60 CGE. Mean F/U 2.8 years
 * Outcome: 0% progression, 38% regression
 * Toxicity: 31% maintained useful hearing. No CNV or CNVII dysfunction
 * Outcome: Fractionated PT excellent LC

Toxicity

 * Please see Inner Ear NTCP for more information

Bevacizumab

 * Harvard; 2009 PMID 19587327 -- "Hearing improvement after bevacizumab in patients with neurofibromatosis type 2." (Plotkin SR, N Engl J Med. 2009 Jul 23;361(4):358-67. Epub 2009 Jul 8.)
 * Retrospective. 10 patients, NF-2 and progressive vestibular schwannoma, not candidates for surgery/RT. Treated with bevacizumab 5 mg/kg, median duration of therapy 12 months
 * Outcome: tumor shrinkage in 9/10; best volumetric reduction 26%. Hearing response 4/7, stable 2/7, progressive hearing loss 1/7
 * Conclusion: VEGF blockade improved hearing in some patients, and was associated with volume reduction

title: Radiation Oncology/CNS/Acoustic neuroma


text:
User talk:24.71.223.148

Please, don't use explicit vocabulary. --Derbeth 19:58, 10 October 2005 (UTC)

Computer Revolution history...
Hi,

Garrett hasn't been around for a couple weeks, but I'll take care of it. -- SB_Johnny | talk 09:01, 9 September 2006 (UTC)

title: User talk:24.71.223.148


text: User talk:83.172.43.78

title: User talk:83.172.43.78


text:
User talk:193.63.87.227

A-level Computing
Please stop adding nonsense to Wikibooks. It is considered vandalism. If you would like to experiment, use the sandbox. Thank you. --Derbeth

title: User talk:193.63.87.227


text:
User talk:66.194.217.222

Please stop adding nonsense to Wikibooks. It is considered vandalism. If you would like to experiment, use the sandbox. Thank you.

Please stop adding nonsense to Wikibooks. It is considered vandalism. If you would like to experiment, use the sandbox. Thank you. -- Herby talk thyme 15:46, 8 May 2007 (UTC)

title: User talk:66.194.217.222


text:
User talk:217.65.158.95

Please stop adding nonsense to Wikibooks. It is considered vandalism. If you would like to experiment, use the sandbox. Thank you.

title: User talk:217.65.158.95


text:
User:195.144.131.12

Please stop adding nonsense to Wikibooks. It is considered vandalism. If you would like to experiment, use the sandbox. Thank you.

title: User:195.144.131.12


text:
Smalltalk Programming/Preliminaries

Smalltalk is a fully object oriented language.

The most important and consistent ideas in the language are that:

 * 1) there are objects
 * 2) send messages to objects
 * 3) get back an object as the result.

So 2 + 3 is considered as "sending a message + to object 2, with argument 3 and the result of the message is another object 5"

title: Smalltalk Programming/Preliminaries


text:
Blended Learning in K-12/Why is Blended Learning Important?

Now that you know what blended learning is, you may be asking yourself, "Why do I need to know about blended learning? Why is it important?" Over the years, many groups of people have asked this same question. These groups have included classroom teachers and others in the field of education, but have also included people in the business field as well. Blended learning makes up the “fastest growing use of technologies in learning—much faster then the development of online courses.” (Alvarez, 2005) Because of the interest in blended learning, there have been many research studies done to find the potential strengths and weaknesses of blended learning as compared to just the traditional classroom or e-learning.

In Education
Educators seem to have the most interest in blended learning, for obvious reasons. Because of this, much of the research on blended learning has been based around classroom situations. All levels of education have been researched with blended learning, from the elementary school grades up to graduate school. Educators’ interests in blended learning is best summarized by Flavin in his E-Learning Advantages in a Tough Economy. He states:

Ironically, the notion of blending is nothing new. Good classroom teachers have always blended their methods—reading, writing, lecture, discussion, practice and projects, to name just a few, are all part of an effective blend. Blending is only a revelation for those who have been trying to do everything with just one tool—usually the computer—and ending up with less than ideal results. Understanding that using the right tool, in the right situation, for the right purpose should be a guiding design principle. (Flavin, 2001)

One clear advantage of blended learning in education is its connection with differentiated instruction. Differentiated instruction involves “custom-designing instruction based on student needs.” (deGula, 2004) In differentiated instruction, educators look at students’ learning styles, interests, and abilities. Once these factors have been determined, educators decide which curriculum content, learning activities, products, and learning environments will best serve those individual students’ needs. Blended learning can fit into a number of these areas. By using blended learning, educators are definitely altering the learning environment when students work collaboratively in learning communities online, for example. Teachers could also add relevant curriculum content that would be unavailable or difficult to comprehend outside of the internet. Learning activities and products can also be changed to use technologies in a classroom that uses blended learning.

So what does the research say? In a study by Dean and associates, research showed that providing several online options in addition to traditional classroom training actually increased what students learned. (2001) Another study showed that student interaction and satisfaction improved, along with students learning more, in courses that incorporated blended learning. (DeLacey and Leonard, 2002)

Another advantage of blended learning is pacing and attendance. In most blended learning classrooms, there is the ability to study whenever the student chooses to do so. If a student is absent, she/he may view some of the missed materials at the same time that the rest of the class does, even though the student cannot be physically in the classroom. This helps students stay on track and not fall behind, which is especially helpful for students with prolonged sicknesses or injuries that prevent them from attending school. These “self-study modules” also allow learners to review certain content at any time for help in understanding a concept or to work ahead for those students who learn at a faster pace. (Alvarez, 2005) Because of the ability of students to self-pace, there is a higher completion rate for students in blended learning classrooms than to those in strictly e-learning situations. (Flavin, 2001) This self-pacing allows for the engagement of every learner in the classroom at any given time. Students also see that the learning involved becomes a process, not individual learning events. This revelation allows for an increased application of the learning done in the classroom. (Flavin, 2001)

With the given research, it is clear that using blended learning in education improves the teaching and learning done in a given course. Educators want to teach in a way that best reaches all of their students. If blended learning accomplishes this, then more teachers will begin to use these methods. When teachers begin to explore blended learning and the resources that can be found through the internet and other technologies, they can structure their classroom in a way that best suits their teaching style and their students’ learning styles. Blended learning allows “[teachers] and [their] students to have the best of both worlds.” (Alvarez, 2005) The traditional classroom and e-learning both have advantages and disadvantages. As Alvarez states, “the online environment is not the ideal setting for all types of learning. Classrooms are not perfect either…. That’s why so many teachers and corporate trainers are concentrating their efforts on integrating internet-based technologies and classrooms to create blended learning environments. It just makes good sense.” (2005)

As stated above blended learning should provide students and teachers with the best of both worlds. I Agree that this should happen, but I am not convinced that this does happen. Teachers that have been teaching for numerous years may be stuck in their traditional teaching methods. These same teachers may not be technology literate which in turn limits what they can do with technology. Teachers must be trained and required to use some type of technology in the classroom if blended learning is going to successfully take place. The teachers may use a variety of teaching styles, but without technology the students are being cheated out of what they need to be successful in today's world. Proper teacher training is the only way teachers and students will "get the best of both worlds." Bret M. Helms

In Business
Blended learning is also of interest to corporate world. Through different studies, blended learning has been shown to be an effective tool in worker training and education. One of the best advantages of blended learning for the business world is its cost-effectiveness. When a business relies purely on instructor-led training, besides paying the cost of the trainer, there are also transportation, hotel, food, and other expenses. Blended learning helps reduce these expenditures by reducing the amount of time needed to face-to-face instruction. (Alvarez, 2005) “Effective blending lets an organization spend the dollars in the most beneficial, cost effective way.” (Flavin, 2001)  A business can decide what mix of face-to-face and e-learning would best fit their learning objectives.

One study which illustrates some of the benefits of blended learning in today’s business world is the Thomson Job Impact Study. (2003) This study had 128 participants from a number of corporate and academic organizations, including Lockheed-Martin, Utah State University, National Cash Register, and the University of Limerick in Limerick, Ireland. The researchers wanted to determine if blended learning increased the overall learning in a number of areas. What they found supports the use of blended learning in the corporate world. The blended learning group “significantly” out-performed the traditional and e-learning group in spreadsheet application performance and they took less time to complete the real-world tasks than did the e-learning group. Overall, the blended learning classroom achieved a performance improvement of 30 percent. (Thomson, 2003). Given these apparent benefits, it is only natural that the business world is now also incorporating blended learning techniques into their employee training and education programs. By doing a quick internet search, a business could find a number of manuals and examples of how to incorporate blended learning strategies into their own programs. There are also companies which specialize in bringing blended learning programs into the business world.

As one can see, the benefits of using blended learning have been carefully researched. Most people would agree that these benefits support the use of blended learning in the classroom and in the business realm as well. It is up to the individual educator or business how best to use the tools of blended learning to meet their own goals and those of their students/workers. really