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User:Criveros0248/enes100/Electric Cars v.2

Link to project ekart v.2 team page.

Give instructor top 3 project choice list

 * 1. Electric Cars
 * 2. R.I.O.T. Wheel
 * 3. Electric Unicycle

Write problem statement
How can I develop an efficient electrical system for the ekart?

Assign Task1
Research speed controller assembly components.

Buy any other needed parts for the ESC System.

Look for more 12V batteries to make the ekart run on 48V instead of 12V.

Compare actual work done to Task1
I finished my research on the ESC system for the ekart. I needed to get contactors (continuous switches) for the ekart's circuit; luckily I found some in the forklift that used to house the DC motor. I tested the motor on 24V using the contactors and two batteries connected in series.

Week1 Narrative
On Monday of this week, I received the electronic speed controller and throttle pedal from China. I was surprised at the fast delivery they provided; it took about 5 business days for me to receive it in the mail.

I also researched the additional components that were needed for the ESC system of the ekart. I needed two contactors (a main contactor and a reversing contactor), a female junction plug, a male junction plug, and some cables. Because I did not know the function of contactors, I did some research and found out that they work like continuous switches used for prolonged contact periods. They also allow the electronic speed controller to reverse the motion of the DC motor if needed. They are recommended for an ESC system of this magnitude (48Vx46A=2.2kW) because they are hard wearing and have great conductivity. Because I knew there had to be some contactors in the forklift that housed the motor, I decided look for the ones I needed for the ekart's ESC system. After looking at the forklift's circuitry, I figured out which one was the main contactor and which one was the reversing contactor. I took those out of the forklift and used them to perform a test run of the donated 1.6HP DC motor running on two 12V batteries connected in series (24V total). Here's a video of the test run:

DC MOTOR TEST RUN

I also ordered the plugs and some LEDs for the ESC system. They should be arriving soon for me to complete the ESC system.

Week1 Peer Review
Peer review week 1

Assign Task2
Work on ekart's circuitry. Mount 1.6HP DC motor on ekart. Connect motor using modified drivetrain.

Compare actual work done to Task2
Mounted DC motor on ekart. Modified drive-train and attached motor to axle using bike chain and sprockets. Continued work on ESC system. Mounted car batteries on ekart's battery compartments.

Week2 Narrative
During this week, I continued working on the ESC system for the ekart. I decided to make a 5"x10" mount for the ESC assembly using 3mm thick steel sheet. I placed the main and reversing contactors, the 200A Kelly controller, and the reverse switch on the mount. I decided to bolt the ESC assembly beneath the steering wheel because it was the only spot where I had extra space. I also used an old steel supermarket basket to make the surface of the battery compartments on the ekart. I welded the flat surfaces for the battery compartments to the existing side battery arms and tested their strength by placing the heavy batteries on top of them. After the battery compartments passed their test, I worked on connecting the motor to the axle. I modified the drive-train using an old bike chain and two bike sprockets. I decided to go with a 1:1 ratio to transform the torque of the motor into a higher speed for the ekart. I made a mount for the motor using 3mm steel sheet and welded it to the ekart frame. I still need to figure out a way to reduce the vibration of the motor though because it gets really loud at high speeds.

Week2 Peer Review
Peer review week 2

Assign Task3
Finish all connections. Complete ekart's ESC circuitry. Sand and paint frame. Work on braking system; add a direct brake pedal to the left of the throttle pedal.

Compare actual work done to Task3
Worked on ESC system throughout the week. Sanded the frame to get it ready for black paint. Ordered additional parts.

Week3 Narrative
During this week, I worked on finishing up the ESC system for the ekart. I took my work from past week off the ekart to test it on a bigger area. I also wanted to be able to show all of my components and connections. I dismounted the motor off the ekart to connect it to the ESC system. I decided to go with a bigger battery system, so I decided to make a 36V power source using 4 batteries connected in series: I placed everything on the ground and began completing the ESC connections to the main contactor. I connected a precharge resistor and diode to the main contactor. I also finished the other connections to the battery and the motor from the contactor. I also replaced the small green LED bulb that I initially used for an LED strip that I had at home. I got rid of the reversing contactor and reverse switch after I realized my ESC does not fully support reverse controlling (I would need to buy additional components for $50.00). I also added a kill switch for safety purposes. Here's a picture showing all connections: After I completed the circuit and all connections were finished, I performed a power up. I also tried the 3-way pot TPS to make the motor turn, but it did not work. Later, I realized that I needed a hall effect sensor that essentially uses magnets and a 0-5V signal rather than a resistor that uses a 0-5K resistance signal. I tried to program the ESC by connecting it to my laptop. To do this, I had to disconnect the motor from the circuit. After I did this, I got an LED error. After reading the manual, I realized this LED error was in the manual and it was related to an incomplete ESC circuit. Later, I tried running the Kelly Controller programming software and plugged all the necessary cables, I was unable to program the ESC because I needed the right interface:Kelly RS232 converter; it should be arriving soon though.

Week3 Peer Review
Peer review week 3

Assign Task4
Finish ekart's minor details and record test run if possible.

Compare actual work done to Task4
Finalized work on ESC circuit. Tested ESC system using hall effect TPS. Worked on final materials list and tutorial. Worked on project team page. Unfortunately, I was not able to complete a test run because the 0.5" diameter axle bent and broke.

Week4 Narrative

This week, I received the hall effect TPS and the RS232 cable (programming interface) for the ESC. I connected the hall effect sensor to my circuit, performed a power-up, but still the motor did not rotate. After checking that my circuit was indeed correctly connected, I tried again but still no results. Then, I moved on to programming the controller using the right interface this time. I disconnected the motor from the circuit, and connected the ESC to my laptop using the RS232 cable. This time, I finally saw the programming software running for the first time. It's not a software that allows you to truly program the ESC but rather it's an easy-to-use interface that allows the user to input whatever values he/she wants in order to alter the performance of the ESC.

I also realized that there was no way of making the ESC circuit work with the TPS without first programming the ESC. First, I had to turn on the kill switch I had installed; then, I had to tell the ESC that the TPS I was going to use was the hall effect sensor. Finally, the most difficult part was picking the right voltage values (signal) for my 0-5V TPS to work. I had to do some more research online and found how to do this in an EV forum. Finally, I tested my ESC and I finally received the right output: the DC motor was now rotating and responding to my new TPS. I tried to record a test run after I mounted everything on the ekart and painted it black with spray paint, but unfortunately the rear axle was too weak and broke after placing the weight of the motor and my body on the ekart. I am going to continue working on the ekart as personal project though and will put a 1" solid axle instead of the 0.5" axle that broke in half. Finally, this week I also worked on a final materials list and a tutorial presentation for future ENES100 students to look at in case they want to work on a similar project. I wish I had finished this project sooner and showcased it in HCC to get further funding for future students who might want to work on this project. Unfortunately, I was working mostly by myself and did not have enough time and resources to complete it in 4 weeks.

Week4 Peer Review
Peer review week 4


text:
Engineering Projects/Electric Cars/Howard Community College/Fall2011/550 ekart v.2 Weekly Reports

Link to project ekart v.2 team page.

Week Zero

 * Research circuitry assembly for ekart.

 * Bought more materials (cables, plugs, fuses, etc.)

Week One

 * Tested DC motor.

 * Tried to program ESC.

 * Worked on ESC circuitry.

Week Two

 * Modified ekart's drive-train.

 * Mounted motor and batteries on ekart.

Week Three

 * Worked on ESC circuit.

 * Sanded and prepared ekart for black paint.

Week Four

 * Painted ekart.

 * Completed ESC circuit and tested it.

 * Programmed controller.

 * Worked on project team page.

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


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User talk:Dhaval

 Hello Dhaval, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. All users are expected to abide by our Privacy policy, Civility policy, and the Terms of Use while at Wikiversity.

To get started, you may

 * Take a guided tour and learn to edit.
 * Visit a (kind of) random project.
 * Browse Wikiversity, or visit a portal corresponding to your educational level: pre-school, primary, secondary, tertiary, non-formal education.
 * Find out about research activities on Wikiversity.
 * Explore Wikiversity with the links to your left.

 * Read an introduction for teachers and find out how to write an educational resource for Wikiversity.
 * Give feedback about your initial observations
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You don't need to be an educator to edit. You only need to be bold to contribute and to experiment with the sandbox or your userpage. See you around Wikiversity! --Abd 18:00, 11 November 2011 (UTC)

Your post on the Colloquium
is probably too vague to leave there, and that really isn't a place for general questions. except about Wikiversity itself. I've deleted it. You are welcome, however, to ask me any questions you like on my talk page, or you may ask here, or you may ask questions on the talk pages of relevant resources.

title: User talk:Dhaval


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User:Chaagii 0817/Apps

Back to Creators team page.

Give instructor top 3 project choice list
I choose to do App because I didn't fill out that form.

Write problem statement
I am planning to work on IPhone application because I have Itouch so I can able test my application if can develop any new application. In order to do that I need to look through internet.

Assign Task1
Basically, I am going to work with apple application.

Compare actual work done to Task1
Figure out that I can do it by myself without any help. Only think I will use is Introduction.

Week1 Narrative
The tutorial how to make Iphone,Ipad or Itouch application.Introduction Apple iOS Developer Library. I would recommend don't go any other web sites because I got virus by downloading one program which was called EasyApp.

Week1 Peer Review
I went through my teammates page ;however, the week 1 was empty.

Assign Task2
Start working to build new simple application.

Compare actual work done to Task2
Rationalize differences

Week2 Narrative
Upload photos to wikimedia. Upload video to youtube. Convert all spreadsheets, documents, and presentations to wiki format and create wiki subpage of your page for each of them. Link to them here in a narrative that tells a story. High light the problems (engineering problems) you had and how you solved them.

Week2 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Compare actual work done to Task3
Rationalize differences

Week3 Narrative
Upload photos to wikimedia. Upload video to youtube. Convert all spreadsheets, documents, and presentations to wiki format and create wiki subpage of your page for each of them. Link to them here in a narrative that tells a story. High light the problems (engineering problems) you had and how you solved them.

Week3 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task4
Record what you are planning on doing for the team during the weekend between week3 and week4 of the project here.

Compare actual work done to Task4
Rationalize differences

Week4 Narrative
Upload photos to wikimedia. Upload video to youtube. Convert all spreadsheets, documents, and presentations to wiki format and create wiki subpage of your page for each of them. Link to them here in a narrative that tells a story. High light the problems (engineering problems) you had and how you solved them.

Week4 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Complete Project Page
Follow the "project done" format.

Start Next Project Week0 activities
During this week you will perform the week0 activities of the next project.

title: User:Chaagii 0817/Apps


text:
Wikiversity talk:Community Review/Global bans

About en.wp bans
I'd like to clarify some history after reading Marshallsumter's contribution: the global bans on meta are not like the crazy bans on the English Wikipedia. Most people who get involved in things on meta tend to be just as aware of the dysfunction on en.wp as most of us here are.

I guess I'm pretty much the last surviving member from the early days who is still active and interested, so I'll give a bit of history: in 2006 when this project came to be, the ugly side of the WP system had just started to become apparent. We (like most other sister projects) wanted to make it clear that falling afoul of the WP inner circle should not be a barrier to participation here. We also tried to come up with experimental alternatives (such as the mentorship system) that we hoped might prove to be good examples that en.wp might adopt. It didn't work out that way, or at least hasn't yet.

I doubt that there will be very many people "globally banned" in the future. The people who get involved on meta tend to be "AGF extremists". The en.wp crowd generally don't care about anything outside their circle, so I doubt they'll be a disproportionate influence. --SB_Johnny talk 20:09, 11 November 2011 (UTC)

 * Good to know, and I appreciate very much your words and effort here. When I was reading the discussion at meta I noticed that en.WP inner circle apparently made a 'gang'-like effort to quell an effort at meta which by shear numbers was successful. I am happy to add that the efforts here with those that came over was both encouraging and good to have happen. Ironically, their headstrong efforts have been used constructively. My serious concern with the global ban is that this may cause en.WP to simply 'take over' all the other projects to everyone's loss.
 * I noticed that we have some vandals apparently going from project to project causing disruption, and in such individual cases the 'global ban' concept is useful. But, like all such tools, it can be used to serve those who would misuse it the most. This is why I believe our own custodians and those above them such as yourself are our first and best line of defense not only with individual vandals but with possible 'gang'-like efforts where reason fails to sway. I would also like to add that I believe this presents WV with a positive opportunity as a resource of higher learning to perhaps add where possible some additional guidance should it be needed. I very much like the fact 'the people who get involved on meta tend to be "AGF extremists".' This is a good thing. Marshallsumter 20:52, 11 November 2011 (UTC)

 * This review is to provide some additional guidance where possible, in light of the global bans proposal at Meta. I think custodian consensus was guidance from the community is needed on this issue. I thought I would get the ball rolling, since there was talk of talking about it and no action yet. -- dark lama  21:04, 11 November 2011 (UTC)

 * The idea of meta consisting of "AGF extremists" is old. It used to be true. It's changed. I ran into many examples of the opposite of AGF. To give an example, in the case of Abigor, conditions were set up where an unblock of Abigor would be totally safe. The community was divided, with what was rather obviously a cabal from one of the 'pedias dominating; if votes from users affiliated with that 'pedia were deprecated, there was a majority for unblock under controlled conditions. But that was disregarded, and the close was to maintain the block, in spite of damage to legitimate work. It's become about punishment (and sometimes, maybe, something even uglier). --Abd 22:33, 11 November 2011 (UTC)

Thoughts about resolutions
There probably four separate issues here where we could come up with opposing alternatives. As I mentioned in my comments, at this point there's certainly nothing we can do to prevent someone from reporting it at meta. --SB_Johnny talk 10:11, 17 November 2011 (UTC)
 * 1. If somebody has a concern about an account that is apparently being used to circumvent a global ban, should they report it to RCA? Should they simply report it to the stewards on meta? Should they report it on another forum?
 * 2. If we're reasonably sure that an account is being used to circumvent a global ban, should we block it?
 * 3. If the "appeals" section of the meta policy is approved, where and how should we hold a discussion about whether an appeal should be made? (CR? RCA? Colloquium? Should the sitenotice be used?)
 * 4. If we make an appeal and it is declined, should we simply detach the account from the unified login, which would override the global lock?
 * 1. Meta has jurisdiction over global bans and SUL accounts, we don't. We have no control over what users do elsewhere. The practical issue is only a local sock or detached account, with the user allegedly being the globally banned user. If a local account is being disruptive, i.e., here, then the fact of a global ban may be relevant, but the legitimate cause of action is not the global ban, it is local disruption. Users may report global ban evasion here, but the result should be careful attention, not a block. Stewards may act if necessary, and they have access to checkuser information as well.
 * 2. Not on that basis. We become enforcers for an outside court, essentially, but that court has its own enforcers. Practically, these outside bans are sometimes enforced and sometimes not. History shows that local enforcement can be disruptive, in itself, if a local account has positive contributions. Wikiversity as a refuge allowing positive contributions from users banned elsewhere is extremely important, it provides a positive outlet for editors banned elsewhere, which, in fact, acts to protect other wikis. Where, in spite of a less contentious environment, users are unable to maintain policy compliance here as well, then we cannot maintain this for them, but we've shown extreme reluctance to truly ban permanently. There are only a couple of examples, and my sense is that if these users were to agree to reasonable behavioral standards, we'd allow them back. The real issue, then, is enforcing compliance; that takes custodians willing to respond, which has sometimes been missing. This can be fixed.
 * 3. This is a red herring. We should decide about our own wiki, not others and not about SULs. We should decide based on our own needs and policies. We have no "representative" to meta (we could, do we want to hold an election? How? It could be done, and, heh!, election methods are my strongest field of expertise.) What happens is that individuals who also edit here have gone to meta and commented there. Nobody at this point has the right to "represent" Wikiversity, to speak for *us,* except colloquially and informally. If one of us thinks a global ban, represented by a global lock, is inappropriate, they can go to meta and support unlocking. I've done that, and I was giving my own opinion, and unlock have been granted, or not.
 * 4. We have, deciding to allow an editor to edit, delinked the SUL account, based on this being cleaner and safer. It makes that account stand out in the SUL display as not linked. Any steward who thinks that the WMF family is being harmed may pop in and locally block, but, shall we say, they better have a good reason, because, historically, this has caused massive disruption. However, this is what Pathoschild did with all Thekohser accounts, coupled with delinking, specifically to allow local wikis to decide -- any admin could then unblock, and quite a few did. Mike.lifeguard then reinstated the global lock, defeating all those local actions, and we are not privy to what discussions were behind that, he refused to say. I think that it was decided that it was better to require a 'crat decision, but this has never been formalized. Mike.lifeguard resigned immediately when Wikibooks decided to delink. He claimed there was no connection, though.
 * Of course anyone can complain at meta. Stewards are generally trusted to make sane decisions. Most are quite aware of the hazards of stepping on local toes. They will doubtless lock an SUL account, if there is a formal global ban (that's only the case with Poetlister and one other totally noncontroversial user), they did this when it was believed -- incorrectly -- that S Larctia was Poetlister. What I don't know is if they can lock an isolated account that has not been globally linked. I'm sure that they cannot lock a detached account, i.e., there is an SUL, but the local account is detatched. They would have to descend from Olympus and locally block. We would then have the choice of overturning that local block, or not. I think our policy prohibits wheel-warring with a steward. By policy, then, we'd need to show local consensus to reverse a steward decision.
 * Our policy, even though labelled a proposed policy, exists for very good reasons, and it protects us from needing to make any decision at all based on outside considerations. I do not want to propose an absolute rule that says *never.* However, all exceptions that I can think of would also justify steward intervention, and they have the tools and power and are not subject to our local consensus and policies, though they are advised to respect them where possible. We should keep our local business simple. It's far cleaner. --Abd 15:14, 17 November 2011 (UTC)

Discussion between Thenub314 and Abd

 * [removed my comments, wrong place for them.] Thenub314 21:01, 18 November 2011 (UTC)

 * The original comments from Thenub314 may be read at, in the collapse box. My comments should be read in that context. --Abd 19:32, 26 November 2011 (UTC)
 * If possible, we should have community consensus on whether or not to enforce global bans, as a matter of policy. If we don't, what then happens is that they are enforced based on the personal opinions of the custodian, not our community consensus. Sure, we can then have a discussion, but if policy is clear, such a discussion may not be necessary. Ban discussions are typically messy except in obvious cases, i.e., there is clearly a local problem from the user. Our policy, as it's been stated for years in the "proposed policy," states clearly that users are not to be blocked based on behavior elsewhere. If this is not the case, if bans declared elsewhere are to be locally enforced, by local custodians, then the proposed policy should be changed. And if they are not to be locally enforced, this still allows a steward to enforce, with all that this implies. Our custodians, then, don't jump into the firing line, either way. Present situation: one custodian enforced the global ban, another enforced the local policy, unblocking. Neither one found clear local consensus first. That situation is a set-up for conflict, from not having a clearly established policy.
 * Personally, if global bans are to be enforced, and because I know that it is possible to obtain such bans based on participation bias at meta, I'm less likely to participate here, and to encourage others to do so, it would feel like building a house on sand. I'm fully responsible for what I do here, as are others, and what I've done elsewhere has been based on my assessment of the needs of other wikis, and my own goals there, not the purposes and goals of Wikiversity. WV has been a safe place, mostly. I see that as possibly being about to change.
 * I'll be clear about one thing: unless policy clearly sets limits, a local consensus would be required to reverse a local block by a steward. A WMF-ordered block would not be reversible even with local consensus, the WMF owns the wiki. However, it has an implied contract with us, to operate it. If the WMF withdraws from that, we may choose to continue here or not. A true local consensus would have the power to fork. So far, I've seen nothing from the WMF even remotely indicating that this would be necessary. I'm just delineating the boundaries here. --Abd 19:07, 18 November 2011 (UTC)

 * Thenub314 responded with further thoughts on the topic. I think these are important in terms of understanding his position. His claim that this was not the place for the comments may be technically correct, in a process sense, but, then, what place would be appropriate? We are discussing the ban issue. --Abd 19:32, 26 November 2011 (UTC)

Guys, I was just trying to come up with how to phrase the things we can vote on. How should we word the alternatives, etc. --SB_Johnny talk 20:38, 18 November 2011 (UTC)
 * Oops. (If I had a blushing emoticon I might user it here) Thenub314 20:48, 18 November 2011 (UTC)
 * There is no global ban policy at meta, and so deciding how we will react to an imaginary policy is premature. However, there are global bans, which have been done ad-hoc. We should really decide policy as it applies to the immediate issue, which is only, practically speaking, at this point, the global ban of Poetlister. The Poetlister situation itself should not be decided here, since this is not a CR on Poetlister. However, policy issues are involved, our current policy seems to prohibit blocking a user who isn't being disruptive here, and this has long been understood. Is there a "global ban" exception? Global bans have been declared and enforced globally through locks, and sometimes through local blocks implemented by stewards, but in no case where there was local challenge to this did the global ban stand as applying to Wikiversity. Is this now to be changed? Below, I start to examine the arguments and positions expressed in this CR, together with a brief look at the experience of those commenting, so that we may start to understand our community's position on this, before coming up with specific resolutions. The resolutions should be designed to be most likely to find consensus, otherwise we will burn out the community, which can tire of commenting and voting, over and over. --Abd 15:11, 25 November 2011 (UTC)
 * You still haven't had time to read my essay yet, have you ? -- Simone 20:19, 26 November 2011 (UTC)

Reviewing arguments

 * This section will start with attributed arguments. It will be refactored to remove attribution.

 * Thenub314. If a decision at meta was made with announcement here and participation by members of our community, we should respect the meta decision, at least at first. We should not ever require a custodian to take any specific action. A local discussion may be closed, with unblock, if appropriate.
 * SB_Johnny We cannot circumvent a global ban, but we may be able to ask for unban. Local users may report ban violations at meta.
 * Marshallsumter WV should be kept as independent as possible, decisions about users should be based on user behavior here.
 * Bilby Global bans are necessary because without them, a person may move from wiki to wiki, replicating damage. The wider community may be damaged by the actions of a user here. Supports enforcing global bans if there was a "genuine community discussion" on meta.
 * AbdGlobal bans are decided at meta re perceived overall welfare of the global community. Wikiversity custodians are only responsible for what happens on Wikiversity. Generally, local wikis may bypass "global consensus," as expressed at meta. Because global bans are decided at meta, they should be enforced through stewards elected at meta. Local decisions should be based on local policies, and enforced through locally trusted servants. Individuals may be disruptive in one context and cooperative in another.
 * Ottava Rima It is the job of our custodians to enforce global bans.
 * S Larctia Custodians should not support users who have disrupted more than one WMF project.
 * Jtneill Local decisions should not be based on activities elsewhere, users should have a clean slate here. Global ban enforcement is a steward role.
 * Thekohser "The independence of the Wikiversity community and process should come before a blind fealty to matters that happen on Meta."
 * Steven Walling Stewards enforce global bans. Local socks are a judgment call for local sysops, pursuant to community consensus and the needs of the project.
 * Gravitoweak Global bans are "impossible," leading to Whack-a-mole games.

 * KYPark "the global ban in a way is an analogy to such terrorism as scapegoating, Inquisition, excommunication, and [bullying].

 * Ebe123 No custodian should have anything to do with global bans. Socks may be reported at meta.

Reviewing contributors
In understanding arguments and positions in a CR, and how these are to be applied to make a community decision, it can be important to understand the experience of the contributors. This section is for that. Errors here should be corrected and the corrections signed. Note: all users have the right to contribute, no matter what their history.--Abd 14:56, 25 November 2011 (UTC)

Reviewing positions
The issue before Wikiversity is whether or how to enforce global bans here. This section will review the preliminary positions of contributors on this issue, as expressed in the CR. The goal is to understand what consensus may be forming, or to understand lack of consensus, to guide us in moving forward and determining if we are ready to poll on some decision, which might create or change policy. I will summarize positions here. However, I ask any contributor whose position I have incorrectly summarized to correct the error and sign the entry as corrected. After each comment I place an evaluation on the issue of default blocking of globally banned users, +1 being support for automatic respect for meta-declared bans, 0 being neutral or unclear, and -1 being opposition. --Abd 15:00, 25 November 2011 (UTC)
 * 1) Thenub314. Block any globally banned user who edits here, if Wikiversity was invited to comment in a meta ban decision and the decision was announced here. Then a local custodian, closing a discussion of the user, may unblock. +1
 * 2) SB_Johnny We cannot circumvent a global ban, but we may be able to ask for unban. Local users may report ban violations at meta. Sees reasons in favor of local blocking and against. 0
 * 3) Marshallsumter Opposes local enforcement of global bans. -1
 * 4) Bilby "block if someone is globally banned through a genuine community disccusion on Meta and it is clear that they are editing through the ban, and accept a ["strong"] community consensus to unblock if that's what later emerges." +1
 * 5) Abd Block locally only for local policy violations, leave meta ban enforcement to stewards. -1
 * 6) Ottava Rima It is the job of our custodians to enforce global bans. +1
 * 7) S Larctia Global bans should be enforced locally. +1
 * 8) Jtneill Local decisions should not be based on activities elsewhere, users should have a clean slate here. Global ban enforcement is a steward role. -1
 * 9) Thekohser "The independence of the Wikiversity community and process should come before a blind fealty to matters that happen on Meta." -1
 * 10) Steven Walling Stewards enforce global bans. Local socks are a judgment call for local sysops, pursuant to community consensus and the needs of the project. -1
 * 11) Gravitoweak Global bans are "impossible," leading to Whack-a-mole games. -1
 * 12) KYPark Considers global bans dangerous, wishes for custodians to "keep global bans from abuses and misuses." -1
 * 13) Ebe123 No custodian should have anything to do with global bans. Socks may be reported at meta. -1
 * Unsigned entries above, at this point, are my summaries. --Abd 16:10, 25 November 2011 (UTC)

Overall analysis by Abd

 * Out of 13 contributions, and without considering the "experience" factor, I see 4 supports for automatic blocking as a default, 6 opposing that, 1 neutral (SBJ). However, the position of Steven Walling might be considered ambiguous. I've classified Walling's position as negative because he is, in fact, leaving the matter up to sysops pursuing community consensus and needs, which would presumably include respecting local policy and consensus from the past. He does consider blocking of identified socks to be "wise," but is also explicit that this is up to local custodians and the local community. He is not taking the position that a "strong community consensus" must exist to allow unblocking, and considers blocking/unblocking (and, presumably, delinking to bypass a lock) a matter of local discretion. Hence my classification at this point. Walling is really ratifying the status quo, long-standing tradition. However, if I shift Walling to neutral, this would give us 4/5/2. --Abd 16:10, 25 November 2011 (UTC)

 * In discussions below, some seem to think I'm proposing a conclusion here. No, not yet. (What conclusion? There is no conclusion above, just data.)
 * The analysis above was done with respect to "automatic blocking" because the current problem is over whether or not global bans should be enforced by local sysops absent local misbehavior. I acted in the instant case based on my understanding of policy, and it was claimed that that was contrary to consensus. Is that true? That's the question I've asked myself and I have only one element in an answer above. A more complete answer will address the arguments (and for that, it doesn't matter who made the arguments) and the experience of the users (i.e., if we factor for experience, including prior participation here, does this reveal some kind of bias among those not familiar with Wikiversity?). This could be similar to deprecating SPA !votes in a Wikipedia AfD, common practice. --Abd 21:57, 25 November 2011 (UTC)

Discussion

 * This analysis seems relatively biased, and boils everything down to a vote. Thenub314 16:49, 25 November 2011 (UTC)
 * A judgment of bias may appear in the mind of someone with bias opposite to the judged bias of the one judged. "Seems," then, is correct. To move beyond this, we'd need to look at details.

 * First question: are there any errors in the individual summaries, or errors in the analysis, i.e., miscounting, whatever, where a material fact is not disclosed? I'll say this: I was careful to be as neutral as possible, without tossing aside what I can see. Given that this issue has torn Wikiversity apart previously, that a "global ban" declared and enforced here by Jimbo led to his loss of Founder tools, in a discussion that was running 2:1 at meta against a proposal to remove them, which then flipped when Jimbo similarly interfered at Commons, to 4:1 for removal, with over 500 votes, this is a topic on which hardly any knowledgeable Wikiversity user will be completely neutral. It damned near wrecked this place, heavily impacted the growth of Wikiversity, experienced users left and retired or cut way back on contributions, so ... let's be careful here, and avoid knee-jerk responses, and seek genuine consensus. Okay? --Abd 17:41, 25 November 2011 (UTC)
 * I agree with Thenub314. The quality of arguments is more important than numerical factors. Gravitoweak, KYPark, Thekohser, Abd, S Larctia, Ottava Rima and Marshallsumter are all banned on Wikipedia, and their opinions should be discounted. --Xijky 16:52, 25 November 2011 (UTC)
 * Why? They're not globally banned. --SB_Johnny talk 02:56, 26 November 2011 (UTC)

 * My analysis is my analysis, nothing more, nothing less. There is a section above for listing arguments. I do not believe that any decision should be made exclusively by vote; however, and our policies do suggest decision based on strength of arguments. If someone believes that my analysis is biased (whose isn't?), then they are completely welcome to put up their own analysis. Indeed, I'm changing the title of this subsection to "Overall analysis by Abd."
 * Above, as well, there is a section on the experience of contributors, intended to note such things as contribution counts, status here and on other projects, etc. I found the numbers of interest, that's all. They do not and should not control our next step, which would be deriving some sane possible resolutions. The information present in the CR can allow us to do that, but if anyone thinks that the result will just pop out by reading the CR itself, without any analysis, well, they will be totally vulnerable to their own bias, which will perform the "analysis" for them. I found that my understanding shifted by writing this, I have a better sense of what community consensus is likely to be when this shakes out, and I've not completed the process. What I wrote above, in this section on "positions," was really only done first because it was the easiest task.
 * Xijky's comment is opposite to Wikiversity consensus. We have a user indef blocked here who is an administrator on Wikipedia. So? However, Kijky has incorrectly identified users banned on Wikipedia. Gravitoweak and KYPark are not even blocked there. Xijky has low contributions globally, including en.wiki, compared to the users he'd dismiss. He's welcome here, to build resources. And he's welcome to give his opinion, and to have his arguments considered, but that's about it. --Abd 17:27, 25 November 2011 (UTC)

 * Look the whole analysis from word one is flawed, it tries to make it a single issue problem (block/not block) and reduces this one issue to a vote. You clearly see this as a issue in which your personally involved and that your future ability to edit rides on the outcome of this discussion.  Take a look at the last few sentences here, wouldn't it be a wise to abstain from producing the summary analysis of this particular conversation, given that your so involved in the outcome of the discussion? Thenub314 20:27, 25 November 2011 (UTC)
 * This is frustrating. That would be true if some claim were being made that a conclusion should be based on the numbers. In fact, communities intelligently make decisions based on multiple analyses from different points of view. I am not "producing the summary analysis of this particular conversation," I am producing a summary analysis. One analysis, mine. I will also produce some others, by the way, based on arguments and based on experience of those commenting. And I'm seeing it attacked based on alleged bias, without any attempt to explain how the bias actually flaws the analysis. This is ad hominem dismissal of a set of observations.
 * But I'm glad about one thing: Thenub has pointed to a problem with the idea of enforcing global bans. Sure, it's a risk to me, and I could show exactly how, documenting situations at meta, including my own, but that would require examining outside activities. We should make our decisions here based on the welfare of this wiki, which includes and covers the individual welfare of all members of the community. This is not Wikipedia, focused on product, hang the community. For us, education is our product and "educational materials" are a means, but participation here is also part of our product. Learning by doing. --Abd 20:57, 25 November 2011 (UTC)
 * You seemed to feel I did not describe the actual flaws in the analysis, but that was the intention of my first sentence. Thenub314 21:17, 26 November 2011 (UTC)

Reminder
Statements aren't votes. We aren't voting because we haven't come up with anything to vote on. We haven't come up with anything to vote on in part because the earlier attempt to come up with something was buried under walls of text. --SB_Johnny talk 21:53, 25 November 2011 (UTC)
 * We don't need that reminder, SBJ. Nobody here has claimed that there is a vote going on. I merely made one paragraph of analysis that reported numbers, in a section that reported "position" on the most urgent issue before us, as a piece of an overall analysis aimed toward seeking understanding of the positions expressed, precisely in order to make intelligent proposals about resolutions to vote on. --Abd 22:03, 25 November 2011 (UTC) original post continued into "wall of text" issue, now within collapse. --Abd 19:23, 26 November 2011 (UTC)

collapsed by Abd 19:23, 26 November 2011 (UTC) "Walls of text" is your method of dismissing careful argument and consideration of evidence, and disrespecting, in Wikipedian fashion, the work that went into writing that. I'd suggest stopping it, this is Wikiversity. Yes, there is argument that's unnecessary, such as most of that discussion following my analysis in this section. And your reminder. --Abd 22:03, 25 November 2011 (UTC) (e.g. this is one paragraph - I edited/previewed 4 times before posting, and I still feel I could improve it, but I'll hit "Save" now because I've tried to read it through from the perspective of a potential reader, and I feel it's probably pretty clear at this point...) Begoon 13:27, 26 November 2011 (UTC)
 * The phrase wall of text was not being applied to the analysis above, but to the edits by you and me on Nov 17/18th. That was why I redacted some comments, as I could see they were getting in the way of progress. Thenub314 00:49, 26 November 2011 (UTC)
 * Geez, I knew that. The "careful argument" was in specific response to SB Johnny's questions, and to your remarks as well (later removed by you, not a great thing to do, in fact, I probably should have reverted you, since I'd responded. I think I'll fix that, putting your comments and my response to you in collapse, which should accomplish what you desired without whacking my responses as to context). There were 4 questions, and each one got a paragraph of response. Not a wall of text. If you defocus, and don't care about the issues, sure. Now, with a lot of work, I could refactor that to make it more pleasing to the eye. Is it worth that work for discussion? Obviously, I don't think so. I already spent way too much time writing it. --Abd 02:17, 26 November 2011 (UTC)
 * I took my comments out again, I prefer they remained that way. Thenub314 02:33, 26 November 2011 (UTC)
 * I've restored the collapse, and have placed a reference to the original discussion so that my response there can be read in context. --Abd 19:55, 26 November 2011 (UTC)
 * I was asking if those were the questions to be considered, that's all. --SB_Johnny talk 02:57, 26 November 2011 (UTC)
 * Yes, got that. However, what is being examined is what the present discussion reveals about consensus as it stands. I'd assume that no decision would be final until there is some polling, probably. However, answers depend on questions asked, and that's why, in standard parliamentary procedure, it takes a vote to ask a question, and the question may be amended, which also takes a vote.... To avoid cumbersome process, I'm doing a preliminary analysis, which isn't complete. ---Abd
 * I realize, "Is refactoring to make discussion more pleasing to the eye worth the work", may be intended as a rhetorical question, but I think the question is worth answering anyways. Do you think understanding, acknowledgment, and consideration of your arguments are important? If the answer is yes, I think time is well spent refactoring comments because people are more likely to acknowledge and consider arguments they can understand. If the answer is no, I think time shouldn't be spent at all presenting any form of argument, because people are limited in their ability and capability to acknowledge and consider arguments not understood. -- dark lama  08:27, 26 November 2011 (UTC)
 * It's not a rhetorical question, it's a real question, and the answer depends on context. In preliminary discussion, it is often not worth the effort. It should be understood that I might spent two hours writing something here, more time than I can really afford. I already do a lot of editing as part of that two hours. I do not just post raw text, normally. I do not expect everyone to read all that I write. What I've found, in fact, is that comprehension is not necessarily improved by addiitional time spent editing, and much of the complaint about "walls of text" comes from people who will reject what is being said no matter how briefly it's expressed. Sure, I can design polemic, but preliminary discussion shouldn't be polemic. (Polemic must be brief, typically.) --Abd 19:55, 26 November 2011 (UTC)
 * That's common sense. Communication (particularly on a somewhat impersonal medium such as this) is about tailoring your contributions to your desired audience. If one wishes one's contributions to be understood and considered, then presenting them in a manner as easy to assimilate and comprehend as possible seems essential. It feels to me like the polite way to do it, too. Nothing, of course, forces one to communicate this way. But equally, nothing forces the reader to invest the effort which the writer did not. When deciding whether or not to invest the effort, it strikes me that it's best to assume the reader is as busy as you are, and surely the person making the point is best placed to fashion it into something easily digestible.

 * Welcome to Wikiversity, Begoon. Writing can have different functions. Part of the Wikiversity model is "learning by doing," and I personally learn through writing. You can't tell how much time I put into editing, nor how many times I hit "Preview" before saving the edit, just from looking at the product. Let me say that it's often a lot. Further, I often incorporate into my comments a lot of research, research which gave me the background from which my thoughts have arisen. The question is always how much to include. Because I'm actually seeking consensus, in preliminary discussion, which is what we are about here, I tend toward inclusion, i.e, more extensive comment. Later, you'll see, my comments can become almost laconic. Now, if it takes me three hours to research and write a comment here -- and that can easily be the case -- would you think that I must necessarily put in another three to six hours "boiling it down" for maximum impact? Yes, that's exactly what I do when writing polemic, but not when I'm forming my understandings as a shared process. Polemic can inhibit consensus formation. By the way, I've been a professional writer and editor, plus having way too much wiki experience. What was I thinking, I must have been drinking. (Except I don't drink.) --Abd 20:07, 26 November 2011 (UTC)
 * Nevertheless - your comment "...just from looking at the product" goes pretty much to the heart of it. All your readers can do is "look at the product", because that's all they are presented with, so, regardless of the time spent creating it, it is what it is. Just my humble opinion. :) Begoon 01:26, 27 November 2011 (UTC)
 * How they read it may depend on the interest with which they approach it. Transient discussion may be of relatively low interest. Bottom line, the question is how far to invest resources in a discussion. In order of increasing difficulty, there is simple discussion, writing a tome, and writing polemic. Some people seem to imagine that writing polemic is easier than writing a tome, because it's shorter. That disregards the process, and it only is true if a writer is intimately familiar with the topic, essentially has the tome in his or her head already. --Abd 19:50, 27 November 2011 (UTC)
 * "How they read it may depend on the interest with which they approach it." - Indeed. But, all other things being equal, making discussion clear and concise is generally more useful, and more likely to "pique" that interest. I've been known to generate the odd "wall of text" myself. Generally, though, I regret doing that when I do it, and I do try not to - for 3 reasons I can think of (off the top of my head):
 * I want my stuff to be read.
 * The thought processes involved in making my point cogent for others often help in my own understanding, too.
 * I want co-operation and transparency. I do not wish for a situation where it could possibly appear in any way that something I said was "hidden" in a "wall of text" most people did not read, and then later assumed to have been stated "without objection".  (could happen, you know...)
 * Obviously, everyone makes their own decisions, and has their own style, and, as you point out you have lots of experience - so maybe you feel the "tldr" style works well for whatever it is you try to achieve. I'm just offering an additional perspective - from my experience. Okay? Begoon 00:57, 28 November 2011 (UTC)


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User talk:Caypartis

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User:Annoyamouse

Welcome
Hi! Welcome to my user page. :-)

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User talk:Annoyamouse

Welcome
Hi! Welcome to my user talk page. :-)

title: User talk:Annoyamouse


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User:Egm6321.f11.team3/Hwk6

Given
A nonhomogeneous L2-ODE-CC :

$$\displaystyle a_2y''+a_1y'+a_0y=f(t)$$ $$ (6.1.1) $$

Find
1) Find the PDE's that govern the integrating factor h(x,y)for equation 6.1.1. Is it possible to solve these PDE's for h(x,y)?

2) Trial solution for the integrating factor $$\displaystyle h(t)=e^{\alpha t}$$ where $$\displaystyle \alpha$$ is unknown to be determined.
 * {| style="width:100%" border="0" align="left"

$$ Because of the integrating factor in exponential form, assume the LHS of equation (6.1.2)to take the form :
 * $$\displaystyle \int \, e^{\alpha t}[a_2y''+a_1y'+a_0y]dt= \int \, e^{\alpha t}f(t)dt$$
 * $$ (6.1.2)
 * $$ (6.1.2)
 * }
 * }
 * {| style="width:100%" border="0" align="left"

$$
 * $$\displaystyle \int \, e^{\alpha t}[a_2y''+a_1y'+a_0y]dt= e^{\alpha t}[\bar a_1y'+\bar a_0y]$$
 * $$(6.1.3)
 * $$(6.1.3)
 * }
 * }

2.1) Find $$ (\bar a_1,\bar a_0)$$ in terms of $$ (a_0,\ a_1,\ a_2) $$.

2.2) Find the quadratic equation for $$\displaystyle \alpha $$.

2.3) Reduced-order equation: (6.1.3) and (6.1.4) lead to
 * {| style="width:100%" border="0" align="left"

$$
 * $$\displaystyle e^{\alpha t}[\bar a_1y'+\bar a_0y]=\int e^{\alpha t}f(t)dt$$
 * $$ (6.1.4)
 * $$ (6.1.4)
 * }
 * }

 * {| style="width:100%" border="0" align="left"

$$
 * $$\displaystyle \bar a_1y'+\bar a_0y=e^{-\alpha t}\int e^{\alpha t}f(t)dt$$
 * $$ (6.1.5)
 * $$ (6.1.5)
 * }
 * }

which is easily solvable by IFM.

2.4) Use the IFM to solve equation 6.1.5.

2.5) Show that

$$\displaystyle  \alpha \beta = \frac {a_0}{a_2}$$.

$$\displaystyle  \alpha+\beta=\frac{a_1}{a_2}$$

2.6) Deduce the particular solution yP(t) for general excitation f(t)

2.7) Verify result with table of particular solutions for

$$\displaystyle f(t) = t exp(bt) $$

2.8) Solve equation 6.1.1 with $$\displaystyle f(t) = tanh t $$

For the coefficients (a0,a1,a2),consider 2 characteristic equations:

2.8.1) $$\displaystyle (r+1)(r-2) = 0$$

2.8.2) $$\displaystyle (r-4)^2 = 0 $$

2.9) For each case in questions 2.8.1 and 2.8.2, determine the fundamental period of undamped free vibration, and plot the solution for the excitation for about 5 periods, assuming zero initial conditions.

Solution
Solved the problem on our own. 1) Multiplying equation (6.1.1) by the integrating factor h(x,y),we get:

$$\displaystyle {h(x,y)a_2}y''+{h(x,y)a_1y'+h(x,y)a_0y-h(x,y)f(t)}=0 $$

The 2nd exactness condition for N2-ODEs:

$$\displaystyle f_{xx}+2pf_{xy}+p^2f_{yy}=g_{xp}+pg_{yp}-g_y$$

$$\displaystyle f_{xp}+pf_{yp}+2f_y=g_{pp} $$

To apply the 2nd exactness condition,we must calculate the following:

$$\displaystyle f_t=a_2h_t\,;\,f_{tt}=a_2h_{tt}\,;\,f_{ty}=a_2h_{ty}\,;\,f_{tp}=0$$

$$\displaystyle f_y=a_2h_y\,;\,f_{yy}=a_2h_{yy}\,;\,f_{yp}=0$$

$$\displaystyle g_t=a_1ph_t+a_0yh_t-f(t)\cdot h_t-h\cdot f'(t)$$

$$\displaystyle g_{tp}=a_1h_t$$

$$\displaystyle g_y=a_1ph_y+a_0yh_y+a_0h-f(t)h_y$$

$$\displaystyle g_{yp}=a_1h_y\,;\,g_p=a_1h\,;\,g_{pp}=0$$

Substituting these values in 2nd exactness condition:

$$\displaystyle a_2h_{tt}+2p\cdot a_2 h_{ty}+p^2\cdot a_2h_{yy}=a_1h_t-a_0yh_y-a_0h+f(t)h_y$$

$$\displaystyle 2\cdot a_2h_y=0$$

$$\displaystyle h_y=0$$

Hence,

$$\displaystyle a_2h_{tt}-a_1h_t+a_0h=0$$

Thus the PDE is reduced to a ODE which can be solved.

2.1) The trial solution is $$\displaystyle h(t)=\exp(\alpha t) $$. So, $$\displaystyle \int \exp(\alpha t)[a_2y+a_1y'+a_0y]dt=\int \exp(\alpha t) F(t)dt $$. Assume $$\displaystyle \int \exp(\alpha t)[a_2y+a_1y'+a_0y]dt=\exp(\alpha t)[\cancel{\bar a_2}y+\bar a_1y'+\bar a_0y] $$. Differentiating the RHS of the above equation, $$\displaystyle \int \exp(\alpha t)[a_2y+a_1y'+a_0y]dt=\int \exp(\alpha t)[\bar a_1y''+(\bar a_1\alpha+\bar a_0)y'+(\bar a_0\alpha)y]dt $$. Comparing the integrands, $$\displaystyle \bar a_1= a_2 $$. $$\displaystyle \bar a_0=a_1-\alpha a_2 $$. $$\displaystyle \bar a_0=\frac{a_0}{\alpha} $$.

2.2) Using the equations found in the 2.1,we can form a quadratic equation for $$\displaystyle \alpha $$

$$\displaystyle a_1-\alpha a_2=\frac{a_0}{\alpha} $$. $$\displaystyle \alpha a_1-\alpha^2 a_2=a_0 $$ $$\displaystyle a_2 \alpha^2 - a_1 \alpha + a_0 = 0 $$

2.3) The reduced order equation:

$$\displaystyle e^{\alpha t}[\bar a_1y'+\bar a_0y]=\int e^{\alpha t}f(t)dt$$ can be rewritten as

$$\displaystyle \bar a_1y'+\bar a_0y=e^{-\alpha t}\,\int e^{\alpha t}f(t)dt$$

2.4) Using IFM to solve the reduced-order equation:

The integrating factor is:

$$\displaystyle \bar h(t)=exp[\int\,\frac{\bar a_0}{\bar a_1} dt] =exp[\int\,\beta dt]$$

$$\displaystyle y(t)=\frac{1}{\bar h(t)}\int^t \bar h(s)B(s)ds $$ To obtain B(s), $$\displaystyle y'+\beta y = \frac{\exp(-\alpha t)}{\bar a_1} \int \exp(\alpha t)F(t)dt = B(s) $$ Therefore,

$$\displaystyle y(t)=\frac{1}{[\exp(\beta t)]}\int^t \frac{[\exp((\beta-\alpha) s)]}{\bar a_1} \left[ \int \exp(\alpha t)F(t)dt \right] ds$$

2.5) Substitutng $$\displaystyle \beta = \frac {\bar a_0}{\bar a_1}; a_0 = \alpha \bar a_0; \bar a_1 = a_0 $$ in $$\displaystyle \alpha,\beta $$

We get, $$\displaystyle \alpha\beta = \frac{a_0}{a_2} $$

$$\displaystyle \alpha+\beta = \frac{a_1}{a_2} $$

Given
and

Find
Show that the two expressions are equal.

Solution
(6.2.3) can be writen in follows,

According to (6.2.1) and the hint given by teacher

Differentiation rules shows that

So, we can get Therefore (6.2.5) becomes, Integration by parts for (6.2.2)

Find (6.2.9) and (6.2.10) are equivalent.

Given
1st homogeneous solution, pretend not knowing: Trial solution: $$\displaystyle y=e^{rx}$$, r=constant The characteristic equation: $$\displaystyle r_1=1$$, r = constant $$\displaystyle r_2(x)=\frac {1}{x-1}$$, r = non-constant

Find
Explain why $$\displaystyle r_2(x)$$ is not a valid root, i.e. $$\displaystyle u_2(x)=e^{xr_2(x)} $$ is not a valid solution.

Solution
We solved this problem on our own. Using the trial solution, we see that, $$\displaystyle y=e^{rx}$$ $$\displaystyle y'=re^{rx}$$ $$\displaystyle y''=r^2e^{rx}$$ This leads to a characteristic equation of $$\displaystyle ((x-1)r^2-xr+1)e^{rx}=0$$ Since the second term represents the trial solution, only equation 6.3.3 remains. $$\displaystyle(x-1)r^2-xr+1=0$$ Since $$\displaystyle {r}_{1} $$ was applied to the 1st homogeneous solution, resulting in $$\displaystyle u_1(x)=e^x$$ Then $$\displaystyle {r}_{2} $$ must be applied to the 6.3.3 as follows, $$\displaystyle(x-1)(\frac{1}{x-1})^2-x\frac{1}{x-1}+1=0$$ $$\displaystyle \frac{1}{x-1}-\frac{x}{x-1}+1=0$$ $$\displaystyle 1-x+x-1=0$$ $$\displaystyle 0=0$$ Since the left side of the equation cancels, we are not able to solve for x and this makes it a non valid root and solution.

R*6.4 Solution of Legendre equation with n=1
We solved this problem on our own.

Find
For the L2-ODE-VC in 6.3.1, select a valid homogeneous solution, and call it $$\displaystyle u_1$$. Find the 2nd homogeneous solution $$\displaystyle u_2(x)$$ by variation of parameters, and compare to $$\displaystyle e^{xr_2(x)}$$

Solution
First we select a trial solution of $$\displaystyle y=e^{rx}$$ to find $$ \displaystyle u_1(x)$$, $$\displaystyle y=e^{rx}$$ $$\displaystyle y'=re^{rx}$$ $$\displaystyle y''=r^2e^{rx}$$ From this we select $$\displaystyle u_1$$, $$\displaystyle u_1(x)=e^x$$ From King section 1.1, we have $$\displaystyle u_2(x)=u_1(x)\int{\frac{1}{u_1^2(t)}} exp \left \{ \int{a_1(s)ds} \right \} dt$$ By determining the $$\displaystyle a_1$$ term from equation 6.3.1 we have, $$\displaystyle u_2(x)=e^x\int{\frac{1}{e^{2x}}} exp \left \{ \int{\frac{x}{x-1} dx} \right \} dx$$ By using integration by parts for the $$\displaystyle a_1$$ term, we have, $$\displaystyle u_2(x)=e^x\int{e^{-2x} exp \left \{x+log(x-1) \ \right \}} dx$$ $$\displaystyle u_2(x)=e^x\int{e^{-2x} (e^x)(e^{log(x-1)})} dx$$ $$\displaystyle u_2(x)=e^x\int{e^{-x}(x-1)} dx$$ $$\displaystyle u_2(x)=e^x\int({e^{-x}x-e^{-x}}) dx$$ $$\displaystyle u_2(x)=e^x(-xe^{-x}-e^{-x}+e^{-x}) dx$$ By cancellation of terms we see, $$\displaystyle u_2(x)=-x$$

R*6.5 - Finding two homogeneous solutions by using trial solution and variation of parameters
From the lecture slide Mtg 36-3

Given
L2-ODE-VC:

 * {| style="width:100%" border="0"

$$\begin{align} \left( x+1 \right)y''-\left( 2x+3 \right)y'+2y=0 \end{align}$$ (6.5.1)
 *
 * }

Find
Find two homogeneous solutions $$\begin{align} u_1(x), u_2(x) \end{align}$$ by using trial solution $$\begin{align} y=e^{rx} \end{align}$$

Solution
Solved on our own

Differentiating the trial solution as follows:

 * {| style="width:100%" border="0"

$$ \displaystyle y(x) = e^{rx} $$     (6.5.2)
 *
 * }

 * {| style="width:100%" border="0"

$$ \displaystyle y'(x) = r e^{rx} $$     (6.5.3)
 *
 * }

 * {| style="width:100%" border="0"

$$ \displaystyle y''(x) = r^2 e^{rx} $$    (6.5.4)
 *
 * }

Substituting Equation (6.5.2), (6.5.3), and (6.5.4) into equation (6.5.1) gives

 * {| style="width:100%" border="0"

$$\begin{align} (x+1)\left(r^{2}e^{rx}\right)-(2x+3)\left(re^{rx}\right)+2\left(e^{rx}\right)=0 \end{align}$$ (6.5.5) Taking common parentheses,
 *
 * }

 * {| style="width:100%" border="0"

$$ \displaystyle e^{rx}\left[(x+1)r^2-(2x+3)r+2\right]=0 $$     (6.5.6)
 *
 * }

We obtain,
 * {| style="width:100%" border="0"

$$ \displaystyle (x+1)r^2-(2x+3)r+2=0 $$     (6.5.7) Finding the roots by using the quadratic equation formula
 *
 * }
 * {| style="width:100%" border="0"

$$\displaystyle r= \frac{\left(2x+3 \right) \pm \sqrt{{\left(2x+3 \right)}^{2}-8\left(x+1 \right)}} {2 \left( x+1\right)}= \frac{\left(2x+3 \right) \pm \left(2x+1 \right) } {2 \left( x+1\right)} $$    (6.5.8) This gives  two roots:
 *

 * }

 * {| style="width:100%" border="0"

$$\displaystyle {r}_{1} = 2 $$    (6.5.9)
 *

 * }

and

 * {| style="width:100%" border="0"

$$\begin{align} {r}_{2}= \frac{1}{ x+1}

\end{align} $$ (6.5.10)
 *

 * }

There is only one valid root because the root $$\displaystyle {r}_{2} $$ is not a constant.

Finding the first trial solution $$\displaystyle u_1(x)$$ by using $$\displaystyle y= {e}^{rx}$$ and $$\displaystyle {r}_{1} = 2$$

 * {| style="width:100%" border="0"

$$\displaystyle {u}_{1}(x) = {e}^{2x} $$    (6.5.11)
 *

 * }

Rearranging the Eq. 6.5.1,
 * {| style="width:100%" border="0"

$$ \displaystyle y''-\underbrace{\frac{2x+3}{x+1}}_{a_1}y'+\underbrace{\frac{2}{x+1}}_{a_0}y=0 $$     (6.5.12)
 *

 * }

which includes

 * {| style="width:100%" border="0"

$$\begin{align} a_1(x)=\frac{-(2x+3)}{x+1} \end{align}$$ (6.5.13)
 *

 * }

We can find 2nd homogenous solution by using the equation which is from Lecture slide (4) p. 34-5

 * {| style="width:100%" border="0"

$$\begin{align} u_2(x)=u_1(x)\int\left(\frac{1}{u_{1}^{2}(x)}e^{-\int a_1(x)dx}\right)dx \end{align}$$ (6.5.14) Substituting Eq. (6.5.11) and (6.5.13) into above Eq. (6.5.14), we obtain
 *

 * }
 * {| style="width:100%" border="0"

$$\begin{align} u_2(x)=e^{2x}\int\left(\frac{1}{e^{4x}}e^{\int {\frac {2x+3}{x+1}\,dx}}\right)\,dx \end{align}$$ (6.5.15) Taking the inner integral gives,
 *

 * }
 * {| style="width:100%" border="0"

$$\begin{align} u_2(x)=e^{2x}\int\left(\frac{1}{e^{4x}}e^{ln(x+1)+2x}\right)\,dx \end{align}$$ (6.5.16) When it is simplified,
 *

 * }

 * {| style="width:100%" border="0"

$$\begin{align} u_2(x)=e^{2x}\int\left(\frac{1}{e^{2x}}(x+1)\right)\,dx \end{align}$$ (6.5.17)
 *

 * }

Taking the integral above by using Wolfram Alpha

 * {| style="width:100%" border="0"

$$\begin{align} \int\frac{1}{e^{2x}}(x+1)\,dx =\frac{-1}{4}e^{-2x}(2x+3)\end{align}$$ (6.5.18)
 *

 * }

If we put the Eq. (6.5.18) into Eq. (6.5.17), we can find $$\displaystyle u_2(x)$$,

 * {| style="width:100%" border="0"

$$\begin{align} u_2(x)=\frac{-1}{4}(2x+3)\end{align}$$ (6.5.19)
 *

 * }

R*6.6 - Finding a homogenous L2-ODE-VC by using reverse engineering
From the lecture slide Mtg 36-10

Given
Trial solution:

 * {| style="width:100%" border="0"

$$ y=\frac{e^{rx}}{sin x}, r=\text{constant}$$ (6.6.1)
 *

 * }

Characteristic equation:

 * {| style="width:100%" border="0"

$$\displaystyle (r-r_1)[r-r_2(x)]=(r-2)\left[r-\frac {1}{x+1}\right]=r^2+r\left(-2-\frac{1}{x+1}\right)+1 \left(\frac{2}{x+1}\right)=0$$ (6.6.2) which are
 *

 * }

$$\begin{align} r_1=2 \end{align}$$

and

$$\begin{align} r_2(x)=\frac {1}{x+1} \end{align}$$

Find
Find a homogeneous L2-ODE-VC from the trial solution and characteristic equation given above by using reverse engineering

Solution
Solved on our own

Differentiating the trial solution as follows:

 * {| style="width:100%" border="0"

$$ \displaystyle y=\frac{e^{rx}}{sin x} $$ (6.6.3)
 *

 * }

For the first differentiate with Wolfram Alpha:

 * {| style="width:100%" border="0"

$$ \displaystyle y' =e^{rx}\csc x(r-\cot x) = \frac{e^{rx}}{sin x}(r-\cot x)$$ (6.6.4)
 *

 * }

For the second differentiate with Wolfram Alpha:

 * {| style="width:100%" border="0"

$$ \displaystyle y'' =e^{rx}\csc x(r^2-2r \cot x+ \cot^{2}x+ \csc^{2}x)= \frac{e^{rx}}{sin x}(r^2-2r \cot x+ \cot^{2}x+ \csc^{2}x)$$ (6.6.5)
 *

 * }

A homogenous L2-ODE-VC is equal to the product of the trail solution by characteristic equation:

 * {| style="width:100%" border="0"

$$ \displaystyle a_2 y''+{a_1}y'+{a_0}y=\frac{e^{rx}}{\sin x}(r-r_1)[r-r_2(x)] $$     (6.6.6)
 *

 * }

Substituting Equation (6.6.3), (6.6.4), and (6.6.5) into equation (6.6.6) gives

 * {| style="width:100%" border="0"

$$ \displaystyle \frac{e^{rx}}{\sin x}\left[a_2(r^2-2r\cot x+\cot^2x+\csc^2x)+a_1(r-\cot x)+a_0\right]=\frac{e^{rx}}{\sin x}(r-2)\left[r-\frac {1}{x+1}\right]$$ (6.6.7)
 *

 * }

With expanding the inside of brackets and then taking common parentheses of $$\displaystyle {{r}^{2}}$$, $$\displaystyle r$$ and 1, we obtain

 * {| style="width:100%" border="0"

$$ \displaystyle r^2(a_2)+r\left(a_1-2a_2\cot x\right)+1 \left(a_0-a_1\cot x +a_2\cot^2x+a_2\csc^2x\right)=r^2+r\left(-2-\frac{1}{x+1}\right)+1 \left(\frac{2}{x+1}\right)$$

(6.6.8)
 *

 * }

So we get 3 equations for $$ \displaystyle a_2, a_1, a_0 $$ from the equality of both sides,

Solving for $$ \displaystyle a_2 $$

 * {| style="width:100%" border="0"

$$ \displaystyle a_2=1 $$

(6.6.9)
 *

 * }

Solving for $$ \displaystyle a_1 $$

 * {| style="width:100%" border="0"

$$ \displaystyle a_1-2\cot x = -2-\frac{1}{x+1} $$

(6.6.10)
 *

 * }

so we obtain

 * {| style="width:100%" border="0"

$$ \displaystyle a_1=2\cot x -2-\frac{1}{x+1} $$

(6.6.11)
 *

 * }

Solving for $$ \displaystyle a_0 $$

 * {| style="width:100%" border="0"

$$ \displaystyle a_0-2\cot^2 x+2\cot x+\frac{\cot x}{x+1}+\cot^2x+\csc^2x=\frac{2}{x+1} $$

(6.6.12)
 *

 * }

so we obtain

 * {| style="width:100%" border="0"

$$ \displaystyle a_0=\cot^2 x-2\cot x-\frac{\cot x}{x+1}-\csc^2x+\frac{2}{x+1} $$    (6.6.13)
 *

 * }

If we substitute Eq. (6.6.9), Eq. (6.6.11) and Eq. (6.6.9) into a general form of homogenous L2-ODE-VC Eq. (6.6.6), we can have

 * {| style="width:100%" border="0"

$$y''+\left(2\cot x-2-\frac{1}{x+1}\right)y'+ \left(\cot^2 x-2\cot x-\frac{\cot x}{x+1}-\csc^2x+\frac{2}{x+1}\right)y =0$$ (6.6.14)
 *

 * }

Multipling all equation with $$\displaystyle {(x+1)}$$ gives,

 * {| style="width:100%" border="0"

$$y''+\left[2(x+1)(\cot x-1)-1\right]y'+ \left[(x+1)(\cot^2 x-2\cot x-\csc^2x)-\cot x+2\right]y =0$$ (6.6.15)
 *

 * }

Given
Legendre equation with n = 2

Find
Show:

Solution
We solved this problem on our own.

I checked from WolframAlpha that the first homogeneous solution should be Thus, I used (6.7.4) to do the following solution. Put (6.7.1) into standard form According to lecture note (4) p.34-5 According to Wolfram Alpha

Find
For equation(6.8.1) and (6.8.2), do  (a)  Find the 1st homogeneous solution by trial solution (see King 2003 p.28 Pb.1.1 ab) (b) Find the complete solution by variation of parameters with the following excitation:

Solution
We solved this problem on our own.

Part 1.a
Use trial solution Because $$\displaystyle r=\frac{1}{(x-1)}  $$ is not valid root. Thus, the 1st homogeneous solution is

Part 1.b
Use trial solution Put trial solution into equation (6.8.2). According Euler's formula Because we can change the constant for the homogeneous solution, equation(6.8.13) can be the homogeneous solution of equation(6.8.2)

Part 2.a
According to lecture note (4) p.34-5 and (1) p.34-6 The 2nd homogeneous solution: Particular solution: Put equation (6.8.1) into standard form

According to Wolfram Alpha Thus the complete solution for equation (6.8.1) is

Part 2.b
Put equation (6.8.2) into standard form. According to Wolfram Alpha Thus the complete solution of equation (6.8.2) is

Given
The 1st homogeneous solution

Find
Find the find solution y(x) by variation of parameters.

Solution
(6.9.1) can be written as:

= References =

= Contributing Members =

{| cellpadding="10" cellspacing="5" style="width: 95%; background-color: inherit; margin-left: auto; margin-right: auto"
 * style="width: 20%; background-color: wit; border: 1px solid wit; vertical-align: top; -moz-border-radius-topleft: 8px; -moz-border-radius-bottomleft: 8px; -moz-border-radius-topright: 8px; -moz-border-radius-bottomright: 8px;" rowspan="2" |

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title: User:Egm6321.f11.team3/Hwk6


text:
User talk:Chaagii 0817/Apps

Week 0
Look forward to working with you.Fab4187 01:50, 12 November 2011 (UTC)

I look forward to seeing how this project differs in the Android vs. Apple area. Ndelaney9295 08:46, 14 November 2011 (UTC)

10/10 .. week 0 grading

Week 1
It seems like you found a good starting point. I hope to see what you come up with from here. Ndelaney9295 08:46, 21 November 2011 (UTC)

10/10/10 .. looks like you found a starting point ... 1sfoerster 15:38, 21 November 2011 (UTC)

Week 2
Don't see anything. Ndelaney9295 07:06, 28 November 2011 (UTC)

0/0/0 ... nothing to grade 1sfoerster 13:42, 28 November 2011 (UTC)

Week 3
0/0/0 .. nothing to grade 1sfoerster 15:09, 5 December 2011 (UTC)

Week 4
0/0/0 ... nothing to grade 1sfoerster 15:53, 14 December 2011 (UTC)

title: User talk:Chaagii 0817/Apps


title: File:DigitalDesign.20111112.pdf


text: File:DigitalDesign (HW).20111112.pdf

title: File:DigitalDesign (HW).20111112.pdf


text:
User:Sönke Rahn

 * Alter Ego

title: User:Sönke Rahn


text:
Logview/Installation

Link to project Eagles team page.

Link to project Andyn6361 userpage.

What is Logview?
Logview is a program used to graph and document the charging of any battery through a charging station.

Materials to Download
VCP Driver

Logview Software

Disconnect the LiPo Charger before installing the VCP Driver.

Steps to downloading the VCP Driver (Must be downloaded before Logview)
1. Click on the link to download the VCP driver

2. Choose which kit is suitable for your operating system

3. Save the kit to your computer

4. After the kit has been successfully saved, the installation window pop-ups. Go through the terms of license agreement and choose where the program would be saved on the computer

5. Once the window says that the installation has been done, another window pops up, asking for the user to install the driver. Click install and the window will say it has been successfully installed.

6. After the installation is completed, restart the computer before installing Logview.

7. Connect the LiPo Charger and make sure it successfully installs at a serial port using the control panel hardware device manager.

Steps to downloading Logview
1. Click on the link to download Logview

2. Click on LogView_2.7.4.485 presented as the Most Popular File to the right.

3. Save Logview to your computer.

4. Once Logview has been saved, open it and the installation window will pop up. Agree to the terms of license agreement and go through the installation process.

5. Click done once the installation is completed.

Steps to setting up Logview
1. Go to the start button and go to all programs. Find Logview V2 and click on Logview.

2. Logview will pop-up a window in german. This is the settings configuration window. Change the language from deutsch to English by clicking on the tab.

3. Continue through the settings process. The next page will ask which port device to use. Make sure the port device you are using is the one with the usb connected to the charging station.

4. After you have choosen the port device, Logview will ask which device to use. Scroll to select a charging station. The Thunder AC6 Dual Power charger is a Bantham E-Station BC-6.

5. After the device is chosen, Logview will ask where should the Logview files be saved. Choose whatever folder to save in. If no folder is choosen, each file saved will stimulate a dialogue box.

6. Next Logview asks whether to enable the autosave function. Autosave will save every document automatically to avoid accidental loss of documentation. Choose whether or not the enable the function and continue on the settings process.

7. The last step is to wait for the donation screen to count down to 0. Click finish and Logview will open.

Using the Charger
Video of the "Thunder AC6 Dual Power Charger"

title: Logview/Installation


text: File:Dipole Diagram.JPG

title: File:Dipole Diagram.JPG


text:
User talk:Abusemerump

 Hello Abusemerump, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. All users are expected to abide by our Privacy policy, Civility policy, and the Terms of Use while at Wikiversity.

To get started, you may

 * Take a guided tour and learn to edit.
 * Visit a (kind of) random project.
 * Browse Wikiversity, or visit a portal corresponding to your educational level: pre-school, primary, secondary, tertiary, non-formal education.
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You don't need to be an educator to edit. You only need to be bold to contribute and to experiment with the sandbox or your userpage. See you around Wikiversity! --Ottava Rima (talk) 06:17, 12 November 2011 (UTC)

Thanks, but, uh, a bit of a problem with the username
. Thank you for your spelling correction. Because of the offensive username, I'm blocking you, but you are welcome to register a legitimate user name and participate on Wikiversity. We won't hold the old name against you. Uh, let's try this again, from the beginning. log out/create new account. --Abd 12:26, 12 November 2011 (UTC)

title: User talk:Abusemerump


text:
Wikipedia/Types of user accounts

In a sense, on Wikipedia all users are equal: all people contributing to the project are expected to stick to the same rules, and when it comes time to discuss how to manage issues, all contributors have an equal voice. That said, there is a difference in what different contributors can do, and that is where this lesson comes into play.

IP editors
Anyone editing without first creating an account is identified by their IP address. An IP address is a series of numbers which identify the network location of your computer. As such, IP editors lose a certain degree of privacy, as depending on the circumstances that IP address can be used to discover the country, city and potentially the location from which the contributor is accessing Wikipedia. Along with the reduction in privacy, IP addresses often change, and as a result it is difficult for someone editing without an account to build a reputation as a valued contributor.

In terms of editing, IP editors can edit any unprotected page. However, they are unable to create new pages or upload files, and their edits tend to be given special attention by those looking at recent changes.

New accounts
New users are able to make changes to unprotected resources (which is the default status for the vast majority of pages), but are not able to edit protected resources or to upload files. By having an account, they are no longer identified by their IP address, which provides a greater degree of privacy. The single account name also makes it easier for contributors to build a positive reputation and relationships with other contributors.

The unified login (SUL) process permits users with an account to have a common username across all the Wikimedia Foundation projects. Thus the same username and password could be used to log into Wikiversity, Wikipedia, Wikibooks and Wikimedia Commons, to name but four of the projects.

Autoconfirmed editors
After four days and 10 edits, most users with a user account is automatically autoconfirmed. This provides them with the ability to upload files, edit semi-protected pages and perform page moves.

Established users
There is no formal definition of an "established user", and they don't necessarily have any more rights than an autoconfirmed user. In practice, though, an established user is someone who has been around long enough, and who has done enough, to build up a bit of a reputation as a valued contributor. Established users may take on extra responsibilities, such as mentoring new editors, and they may gain extra user rights, such as rollback and auto patrolled, but the main advantage is that these are people who have been around for long enough to know how things work, understand policy, and who have demonstrated that they are able to work within Wikipedia's framework.

Administrators
Administrators are, (as their name would suggest), responsible for administrative actions, such as blocking and unblocking accounts, deleting and restoring pages and files, and protecting and unprotecting content. As these tasks are both essential and open to misuse, custodians are carefully selected by the Wikipedia community. Administrators need to be trusted contributors who have demonstrated that they understand Wikiversity's policies and are able to interpret consensus accurately and consistently. As a result, the community has big expectations of administrators, such that it is expected that contributors have at least 6 months experience and over 2000 edits before applying for the role.

It is important to note that administrators may have extra tools that they can employ, but in terms of finding consensus they are no more able to direct debate than any other contributor. The administrator role is an important one, but determining policy, selecting administrators and engaging in debate are things that all contributors are encouraged to take part in as equal members of the community.

Checkusers
CheckUsers have the ability to compare user accounts and IP addresses to determine if they are being used by the same people. Abusing accounts, in particular to get around a block or ban, or to lend the appearance of additional support in a debate, is not permitted on Wikipedia, and the CheckUsers have access to the tools required to investigate where such abuse is suspected. However, doing so requires that CheckUsers have access to potentially private information, such as the IP address from which a registered account is being used. Thus they are limited to highly trusted members of the community, who must be over 18 years of age, are required to provide identification to the Wikimedia Foundation, and who must work within the privacy policy.

Bureaucrats
Bureaucrats are primarily responsible for three jobs: they determine consensus and decide whether or not to promote someone to administrator or bureaucrat; they can rename user accounts; and they can permit bots to operate. As with custodians, bureaucrats are expected to have a deep understanding of Wikipedia's processes, and are highly trusted members of the community.

title: Wikipedia/Types of user accounts


title: File:CLTI.DiffEQ.1.A.20111112.pdf


text:
User:Qchi8375/enes100/engine

link to the team page:qjb-eng

Give instructor top 3 project choice list

 * ENGINES
 * ILLUMINATE CLOTHING
 * electric cars

Write problem statement
I will be working on a stirling engine. from the available designs,none of them could function as is expected of them. The main issue now is to seek out those issues which prevented them from working and design and construct one which is able to.Using tin can material, the cost should not be a problem.

Assign Task1
My task here will be to gather enough knowledge about how a proper stirling engine works if i am to able to begin making one. From the materials to the design i would like to make.

Compare actual work done to Task1

 * From the available workable engines i came across in storage, there actually seemed to be various common errors made at various parts.The main issue was to make a smooth running crankshaft so as to reduce the friction opposing the engines power as much as possible.This picture will show clearly the way the crankshaft is attached to the power stroke of the displacer

Week1 Narrative

 * The stirling engine happens to be one of the very best engines available, in terms of efficiency between the energy input and output. It functions as follows based on the information i was able to get.
 * In the case of the engine i an trying to make, i.e. a tin can stirling engine, the main source is heat from a fire. This heat is tasked with expanding the air inside a closed tin can. Once this air is fully expanded, the hot air tends to move upwards while the cold air sinks to be heated as well. This action alongside the upwards force of the expanding air tends to move the displacer piston . This movement has to be started with a slight push on the wheel.The displacer is usually equivalent to about half the displacer volume.
 * As the displacer moves up and down, the slight airways at the side of the displacer aloows for the air to be forced around in the opposite direction of the displacer. That is when the displacer moves down, the air is forced up. This air also helps to move the power piston hooked up to the crankshaft. This power piston is above the tin can but must remain air tight so as not to let the air inside the tin can escape. Escaping air reduces the pressure inside the can and thus reduces the engines efficiency.
 * the following [|engines video] shows how to begin construction of the stirling engine out of tin cans.*[|engines making tin stirling engines]

 * A tin can stirling engine needs to function with as little friction as possible. Between the crankshaft and all other moving parts, there must be a smooth transition for it to function.
 * Duel Assembly X-Section 4-5-11.jpg

Assign Task2
Now that all my parts are in place, i will continue by moving on to the assembly.

Compare actual work done to Task2
As far as the collection of parts was concerned, I was able to obtain a suitable tin can, some pvc pipes i found in storage made for a good power piston cylinder. The displacer rod was made out of a smoothed out hanger wire. for the displacer itself, i decided to use some styrofoam cut to fit on the insides of the tin can but the bottom area covered by some tin material. the crankshaft too is out of hanger wire.

Week2 Narrative

 * Well firstly there is the usual problem of trying to avoid as much friction as possible in the moving parts of the engine. This thereby meant that there was no way i could use a saw to cut the sides of the tin can. I thus used a pair of pliers as a saw would just go a long way to dent the sides of the tin can beneath the cut. With this dent, the friction is significantly increased. Also the hanger wire initially had some thin rubber coating around it.
 * Also the rubber wire had some thin rubber coating around it. Whenever i used it in this state inside the displacer, it tended to be quite difficult to move smoothly.I thus removed the protective coating by use of a knife. After doing this i also tried to smooth out the wire even more by scratching the knife's sharp edge along its length.
 * For the hole at the top of the engine's lid for the displacer wire to pass through, i tried to make it as small as i could be. Having a large hole at that point only means that a lot of the engine's air would be lost and this pressure loss would mean an inefficient engine. Like i wrote earlier, the displacer itself is made up of styrofoam sealed at the bottom by a flat and light tin material from a soda can. This is simply to allow mt displacer be as light as possible while still displacing the right amount of air for the engine to work. The tin at its bottom was just as a precaution should its bottom get too hot that the styrofoam could be melted. The displacer also was cut to be approximately half of the internal volume of the tin can.
 * For the power piston, i decided to use pvc pipes. this was mainly because they are very smooth on the interior and thus friction would not be an issue. Aso they are a lot easier to cut and attach. For the power pistons, which are to be at the top of the engine lid, i made them by using a simple technique. On the insides of the already cut pvc pipes, I layered it with some wax paper. I then poured epoxy so as to fill the holes to the very brim and set it out to dry. When fully dried. it was now easy to slide the epoxy block out and take off the wax paper. Now the good thing about this is that it fits perfectly into the power piston and so there is no issue trying to design a piston that fits.
 * [|engines how to prepare a stirling engine from tin cans]
 * [|engines making tin stirling engines]
 * Full Assembly Snapshot 3-29-11.jpg
 * Duel Displacer Full 4-5-11.jpg
 * Duel Assembly X-Section 4-5-11.jpg
 * Center Holes 4-5-11.jpg

Assign Task3
Record what you are planning on doing for the team during the weekend between week2 and week3 of the project here.

Compare actual work done to Task3
I began the construction of my engine after putting all the parts i had made together.

Week3 Narrative

 * Before i could start assembling my stirling engine, i had to first do the required calculations for the crankshaft. It is very tricky to make and so it took me quite a long time. First of all, u will want to have the displacer to be fully down while the power piston is at the very end of its oscillation. For this to be possible means that the rise of the crankshaft at the point of attachment of the displacer has to be about half the length of the tin can's interior. Also the power piston's rise at the crankshaft has to also be the same length. Also the rise for the power piston at the crankshaft has to be at an angle of 90 to that of the displacer. this is just to ensure that when they are working together, the displacer will be down as the power piston is up.
 * Also, I got it from Lloyd in class that not attaching the power and displacer piston to the crankshaft will go a long way to reduce the friction in the system. With this i decided to use hie idea to attach the pistons to some very thin pvc tubes which fit quite well with the size of my crankshaft wire. This tube is quite able to spin around and so this would go a long way to help make the piston spin around in its very circular way smoothly.
 * So with this part in place, i could start putting together the various parts. I began by placing the displacer in the tin can and covering the lid. I now had to make sure it covered the tin can perfectly. To the small air spaces at the sides of the lid, i added the amount of epoxy till i was able to seal it as tightly as possible. This part has to be as airtight as possible because any air being lost is the efficiency of the engine being reduced.
 * For the power piston, since it is above the lid of the tin can, i had to make sure it was well done else it would fall off. so it had a lot of time to dry up.
 * When it came for me to attach the pistons to the crankshaft, i was initially having problems joining the wire from the crankshaft to that of the displacer. So to solve this problem, i got hold of some thin rubber material which loses its volume when heated. This turned out to help a lot as all i had to do was to place the two wires inside it and warm the sides with a lighter. This holds them both tight in place.
 * The last part of the crankshaft was the flywheel. This seems as not too important but it actually happens to be quite necessary. This is because for the engine to function, it has to be given an initial push. This push has to be sustained by a massive (not too large) material. Thus the flywheel needs to be quite heavy enough for the engine to support and turn.I made my flywheel out of normal CD's i was no longer using. I just glued three of them together. since the hole at its center is normally larger than a tiny wire, i overcame this problem by adding paper around the wire till it was large enough to fit perfectly.
 * [| engines]
 * [|wood burning engines]
 * [| air compressor]
 * [|fan engine powered]

Assign Task4

 * Once the parts dry fully, I will have to check how well it works and fix any parts that may give trouble.

Compare actual work done to Task4
Rationalize differences

Week4 Narrative
Upload photos to wikimedia. Upload video to youtube. Convert all spreadsheets, documents, and presentations to wiki format and create wiki subpage of your page for each of them. Link to them here in a narrative that tells a story. High light the problems (engineering problems) you had and how you solved them.

Week4 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Complete Project Page

 * [| engines]
 * [|wood burning engines]
 * [| air compressor]
 * [|fan engine powered]

Start Next Project Week0 activities
During this week you will perform the week0 activities of the next project.

title: User:Qchi8375/enes100/engine


text:
User talk:Code07

 Hello Code07, and welcome to Wikiversity! If you need help, feel free to visit my talk page, or contact us and ask questions. After you leave a comment on a talk page, remember to sign and date; it helps everyone follow the threads of the discussion. The signature icon in the edit window makes it simple. All users are expected to abide by our Privacy policy, Civility policy, and the Terms of Use while at Wikiversity.

To get started, you may

 * Take a guided tour and learn to edit.
 * Visit a (kind of) random project.
 * Browse Wikiversity, or visit a portal corresponding to your educational level: pre-school, primary, secondary, tertiary, non-formal education.
 * Find out about research activities on Wikiversity.
 * Explore Wikiversity with the links to your left.

 * Read an introduction for teachers and find out how to write an educational resource for Wikiversity.
 * Give feedback about your initial observations
 * Discuss Wikiversity issues or ask questions at the colloquium.
 * Chat with other Wikiversitans on #wikiversity-en.
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You don't need to be an educator to edit. You only need to be bold to contribute and to experiment with the sandbox or your userpage. See you around Wikiversity! --Abd 14:54, 12 November 2011 (UTC)

Speak Math Now!
Hello Code07! I do apologize for taking so long to respond to your question. My Speak Math Now! course is open for enrollment, and I am very happy that you are interested in the course, but I would like to first ask you these questions that I hope you can respond to:

If you can answer these questions confidently, then I would love to set up an orientation session with you. Just tell me what times would be best for you. My hours are from Monday - Friday 3:00 - 10:00 PM EST and Saturday - Sunday 10:00 AM - 10:00 PM EST. I hope to be working with you very soon! --MrABlair23 02:00, 19 November 2011 (UTC)
 * What is your prior experience with math?
 * Is there a specific topic(s) that you would like to improve on?
 * Will you devote yourself to the course? (I do know that this is a very long course, which is why I have the option for all of my students to start in any particular semester that you would like, and end with any semester. However, please know: You cannot quit in the middle of a specific semester.)

Hello MrABlair23! I am really eager to join your Math Speak Now! course. I think I will start by answering the above questions first;
 * I am in grade 10. I am an average student in math but I want to do better. I want to learn the language of mathematics fluently.
 * Yes, I would like to improve on "Quadratic Equations", "Applications of Trigonometry", "Coordiante Geometry", "Circles", "Arithmetic Progressions", "Surface Areas and Volumes", "Probability and Statistics" and well... many more.
 * Yes, I will devote myself to this course as I have said before I want to learn the language of Mathematics fluently.
 * I am quite confident in my answers.

I would love to start the course as soon as possible but I do believe that we are in two different time zones and I think that might cause a problem. Anyway, my best times are Thursday 4:00 PM - 11:00 PM AST ,that is, 8:00 AM - 3:00 PM EST and Friday 10:00 AM - 11:00 PM AST, that is, 2:00 AM - 3:00 PM EST. (I know the timings are really bad and not appropriate and I am really sorry for that but I am hoping that we can work it out somehow!).
 * Have a pleasant day!! Code07 15:30, 20 November 2011 (UTC)

 * Awesome! I am really glad that you are eager and excited to go with this course. Before we begin the actual course, I would like to have an orientation session with you, so that we can discuss where exactly you would like to start and so that I can test you on where subjects you say that you have mastered. If you would like, we can have our orientation session at 12:00 PM EST this Thursday. Now, I do know that this is Thanksgiving Day, so if you are not available then, then how is Friday at 12:00 PM EST? Let me know which day would be best for you, and I will set up the class and send you the link.

I'm really looking forward to hearing from you and I can't wait to begin! --MrABlair23 23:51, 20 November 2011 (UTC)

Thursday sounds fine! I can't wait either! So, how will this orientation session take place? --Code07 15:49, 22 November 2011 (UTC)

 * Here is the link to the class:

http://www.wiziq.com/online-class/672701-speak-math-now

Simply follow the instructions in the Class Description and I'll see you there! :) --MrABlair23 21:56, 22 November 2011 (UTC)

Hello!

The class is beginning now. Just click the link and go to Launch Class. :) --MrABlair23 17:05, 24 November 2011 (UTC)

title: User talk:Code07


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User talk:Mkhan4793/enes100/Model Boat

10/10 .. week 0 grading 1sfoerster 23:20, 15 November 2011 (UTC)

do you have an old bicycle that we can get the tire tube from?Afayyaz6843 11:00, November 12 2011 (UTC)

Khan G can you try to work on the RC system of your car because we need that one to be working too? Afayyaz6843 12:24, November 19 2011 (UTC)

10/10/50 ... good job 1sfoerster 20:55, 21 November 2011 (UTC)

hey zohaib.. did you work on the mechanism of middle propeller.. i have put the fans on the boat now we just have to think of how to connect it with RC Afayyaz6843 12:37, 26 November 2011 (UTC)

10/10/80 ... good job 1sfoerster 14:51, 28 November 2011 (UTC)

Good job khan you really helped push the project forward with assembling everything over the coarse of this week... will hope to use the RC's next week Afayyaz6843 09:05, 02 December 2011 (UTC)

You have done a great job assembling the things and making them work. Hsingh8658 04:14, 5 December 2011 (UTC)

10/10/80 ... great job 1sfoerster 18:51, 5 December 2011 (UTC)

0/0/0 ... nothing to grade 1sfoerster 16:56, 14 December 2011 (UTC)

title: User talk:Mkhan4793/enes100/Model Boat


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User talk:Hsingh8658/enes100/Model Boat

10/10 .. week 0 grading 1sfoerster 23:21, 15 November 2011 (UTC)

paaa g can you research a different design for the model boat in case the one we watched at YouTube doesn't work. Afayyaz6843 11:03, November 12 2011 (UTC)

Sure, im already thinking of a design; will tell you about that in class on tuesday. Its based on the small kids boats found in water parks which have always rotating circular base.Hsingh8658 04:30, 14 November 2011 (UTC)

how was the design that i showed you guys... remember to bring the tube. Mkhan4793 05:02, 14 November 2011 (UTC)

herman do you have another RC car because you said that we needed three of them? Afayyaz6843 12:27, November 19 2011 (UTC)

No, I know we can make it to work with two! I will be bringing the other one in. Mkhan4793 21:01, 19 November 2011 (UTC)

10/10/30 ... what design did you select? 1sfoerster 20:55, 21 November 2011 (UTC)

hey Harman did you get any idea of how to connect the fans with the remote control? Afayyaz6843 12:31, 26 November 2011 (UTC)

The fans will be connected to the remote by the red coil wire that was attached to the motor and the remote will be connected to the reviever, thus it will make the boat go left and right. Harman, make sure you bring in the outline you were going to make for the connectivity. Mkhan4793 23:35, 26 November 2011 (UTC)

0/0/0 ... nothing to grade 1sfoerster 14:52, 28 November 2011 (UTC)

hey, we are almost done with our boat now. Only have to connect remote control. Come in sometime and check it out. Mkhan4793 23:16, 2 December 2011 (UTC)

Herman wassup man... where u've been last week. Khan has done a great job last week on the project. Just need to work on the controls nowAfayyaz6843 10:58, 03 December 2011 (UTC)

0/0/0 ... nothing to grade

title: User talk:Hsingh8658/enes100/Model Boat


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User:Erdemaslancan

"Bu maskenin altındaki et ve kemiklerden oluşan yüz, benim benliğime ait değil. Bu maskenin altında etten fazlası var. Bu maskenin altında bir fikir var ve fikirler kurşun geçirmez!"
 * — V For Vandetta

29 2024 Monday

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