Chapter 9

Accounting system, games, and photo sharing system is in a order of decreasing their importance of correctness. If an accounting system goes wrong, it would cause serious problems, and there would be money loss - or leak. In this case, it has to be right - at least there are no obvious bugs.
A game is normally a bugged version. The players will complain about this, but it is not such a big deal. If there are not too many bugs, it would be acceptable. Of course, we should reduce that to a minimum amount, and release patches as soon as possible, if something turns out to be wrong.
A photo sharing system cannot be really bugged. It shouldn't be that complicated, and if there is a bug, it is mainly a wrong link or something. It could have some space to allow errors.

About the community partner

The never-ministries are located in the Tenderloin. They are serving people within that district -

including kids or seniors, providing courses and free lab sections. It has a computer lab with about 10 computers, which were not quite new but still in good shape. It is a local organization which is serving the local people around. As we saw, there are not many people going there. Their mission is to provide an opportunity for the local people to learn and use the computer. Our mission there is to teach the people about how to use the internet, how to use the e-mail and so on.

Digital Information WA

I haven't visit a lot of digital service websites in US. In China, there are a lot of such things, however, most of them I think are illegal - or half legal, I think.

baidu.com is the most widely used search engine in China. It is even more widely used than google, because it parses the Chinese words better. Baidu is also a large legal company. However, in the baidu search tabs, there is a tab "MP3" which links to mp3.baidu.com this is a MP3 search engine and searches specific songs very fast and promising. And all of the mp3 are able to free download directly (Most of them are Chinese songs although)，and baidu provides the file size, link speed, author etc. However, I don't think this is a legal way to provide songs - even the latest albums can be searched in this way. And the source itself, may be illegal also. But baidu says like "These are auto-searched results, baidu has nothing to do with this blablabla..". Baidu is one of the most significant Computer-related companies in China, but this direct media search is still violating some of the rules. How do they make money? Ads like Google, of course.

Lets see another example that fits better the assignment. Xunlei is an important downloading software widely used in China, and its free. By the way, this is already ironically enough - how can a downloading software be so popular? Because there are so many thing that people can download - free but illegal. There are millions of software users in China, but no more than 2% software are legal. And what about films and music? Who knows.

Xunlei also provides an movie download engine, however, it takes copies and film names and even comments for the film. But instead on "online watching" or "downloading" it provides a link saying "Online search". And this link leads to a search link, which 99% is available. Okay, so this looks like another search engine, that doesn't take any responsibility of its contents. However, as I tracked down the IP of the downloading link, it is an ftp server that is owned by... Xunlei itself. How funny it is that they are sharing there own files, but they say, no.. I am not the nice one. It is pretty much a way to get rid of trouble, and it is no way against the Chinese law. But this is another illegal example. How do they make money? There are hundreds of advertisements on a single page.

Sopcast is another free software, written by some Chinese guys. It is a p2p online tv/movie software which we can watch live sports or else. Anyone is able to release something on the platform and everyone can see it. However, at least they are providing something that is legal. Which makes some difference. The online-movie part is able for people to watch some movies from their server - quite old ones - for free and they are in the public pot. And most of the live TV they provide are free in their countries. Although those are not the ones that most of the users are intrested in. The development is still an individual team that only works on this software, and they make money through ads and donation.


Since most of softwares or music or movies are "actually" illegal, of course they take no responsibility for them. And the user is free to do anything they want. However, selling illegal CD or DVD copies is illegal to the Chinese law. Which finally protects something.

Since illegal source is so easy to get and everyone does this, it is really impossible to find something "legal" according to the CS-law in China. The illegal way is too widely used that most users don't even think it is wrong. And in this case, if some website is charging some money for online-movies or else, it is like impossible to get any members - even if they are doing the best interface or something. It just doesn't make any sense to pay for just copying something. I'm sorry that I could find any source of legal way to download something. But it simply doesn't exist in China.

The Cathedral and the Bazaar

1. According to the text, "the Bazaar" style is "Linus Torvalds's style of development—release early and often, delegate everything you can, be open to the point of promiscuity—came as a surprise" (Raymond). To the opposite, "the Cathedral" style of software development should be quiet, working until everything is done, and give out a final release.

2.To make a bazaar-style project work successfully, Raymond mentioned a lot of important issues. The programmers interest and attitude should be good. The program code should be well shared and reusable. The user and tester should be treated as valuable as possible. And the most important thing: the releases and feedbacks should be treated as fast as possible. In one word, "Do as the user needs".

3.I think Raymond specified on the user quite much. As I see, this is quite different in bazaar style programming and cathedral style programming. In the bazaar style, if there is a new user request, it is handled by the world or lets say, by the internet. And even only some users' requests might be important for many other users might have the same need. But in cathedral style programming, most programmer or programmer groups are handling one specific user, which might be a company or organization or else. They may have some requests, which turned out to me not really what they want. So they may change their idea, which is pretty frustrating sometimes. Raymond didn't mention a lot about why the user is so important for the bazaar style, but it is true.

4.Based on the bazaar style's specialty, I think some smaller, common, widely used, not-too-complicated, core-based softwares would work out better in the bazaar mode. If it is like this, it can be modified by more people and tested by more people.

5.Large, complicated, used by specific users, these might be the softwares that would like to be in the commercial development style. Which is more organized and payed for these extra-large programs

Assignment for Feb.24

LAMP, stands for:
Linux, the operating system
Apache, the web server
MySQL, the database server
PHP\Perl\Phthon the programming languages

People like the combination of these because they are all open source. And they work pretty well together for building applications especially web applications.

Assignment 2 for Feb 10.

I think there are to reasons for the citizenship for us is quite obvious. Since we are a part in the community, we are responsible to do our work for it (or is that only because I grew up in a Communism county) . After we graduate we will be a essential part or the society and we should play our roll to make it run well.

Even if this is not like a moral rule, it is still quite useful to learn about this. When we go to work, we will face a lot of similar situations as we do during Service Learning, and real experience is the most precious thing for us. College should not only teach us academics but also some real thing we can make use immediately. So I think it is meaningful to have these courses.

Assignment 1 for Feb 10.

Google does a difficult job. It is a company born for the information Age. "Meanwhile, here's Google, which is using the information it collects to build better services that we eagerly consume because they are useful to us"- Tim O'Relly, CEO of O'Reilly Media. Since it is new, if there is a conflict between providing information and keeping information private, there is no rule to follow. Moreover, it is hard to identify the information, which one is all right for some guy, which one is not.

According to the law in any country, there is no way to disallow any one to take any pictures at public places and uploading it on his/her blog or something. The only reason for people concerning about Google is because it is too popular. Too many people would see it, it if is on Google. And sometimes people don't want to be seen by the whole world, especially when they are just coming out from a "Adult Book Store" or something else; or sometimes being caught by friends saying "Hey, you are on Google". However, most of the people don't care or don't even realize fi they are on Google or not. And, for sure, most of the pictures are just regular ones.

In the fact, Google seems to think more about privacy (e.g. at the year year when the DOJ tried to get access to users’ queries, and Google was the only company out of 30+ that said “no” and went to court about it — and won).

In this case, Google also offers a "help" button on all the street-level photos to provide a link for users to request the removal of an image that is objectionable or clearly identifies a person who doesn't want to be included in the visual tapestry. However, company spokeswoman Victoria Grand said Google has fielded "very few" removal requests so far -Michael Liedtke, Associated Press.

In my opinion, it is not a big deal of those photos, it might be for some one, but they have the choice to tell Google the case.

Assignment 2

After I have finished my undergraduate degree I'm pretty sure I will work on a master degree. After that, which might be 4 years later, I think I am going to work for a couple of years, maybe in the States maybe back in China, probably as a software engineer. Then I think I will try to run my own company in China, after I have this experiences. That is my dream and I already have some friends who have this same goal. To reach this goal, I should not only focus on the technology part of software or hardware or something like that, the main issue for me to learn is how to manager a group, a team and a company as well. Which makes this course quite important for it tells me the social issue within this field. Which might be quite important.

Assignment 1

Symmetric keys are exchanged by private communications, such as through a private meeting or something similar. Once the key is distributed, it could be used multiple times,
but no one can change to another key anymore - Not until they meet another time.

Symmetric keys could only be cracked by trying all the possibilities of the keyspace, which often turns out to be very big. And even if the cracked tries out all the possible keys, it still may or may not generate multiple understandable meanings, which could confuse the cracker.

Since it is the same key used both on encryption and decryption, so the only one that can send a code which could be decrypted by the key in the receiver's hand, is the one that owns the same key(What a sentence!). In other words, only the ones that share keys can communicate.

The advantage of the symmetric key technique is that it is fast and safe. Increasing key space doesn't make many performance changes for the sender and receiver who owns the key. But it would be like impossible to crack a 256-bit keyspace. However, the key distributing may cost a lot, especially in the cases where the two objects don't need to communicate a lot of times. And communicating between strangers is also hard to fix in this method.

In the Asymmetric method, the public key can be know by everyone, it can be posted at public places, or mainpages, or everywhere possible. The private key is kept by oneself ,which doen't need to be distributed.

The security of cryptographic in this case is based on the well admitted assumption that it is hard to factor large numbers.

The only message that a public key can decrypt is the one that is encrypted by the owner of the private key. And it is same the other way, which provides the way to send messages and signature documents.

The advantage of asymmetric keys is that there is neither risk or cost by sharing public keys. And if we want, we can change our public key and private key at any time. Which is convenient for totally strangers. However, the encryption and decryption turned out to be much slower and the keys are also larger. And it is not safe enough in the "Man sit in the middle case".

New housing plans

http://www.phillyburbs.com/pb-dyn/news/112-01282008-1478336.html

"Plans call for a new 1,267-square-foot home on one of the new lots. Family Service will build a three-bedroom home for women with mental-health issues. Generally, its adult population ranges in age from 25 to 50. Each resident will have her own bedroom."

"Payanzo estimated some 40 to 50 percent of adults living with mental illness are at risk of becoming homeless and live in substandard housing, including motels, welfare housing and cars."

British people SEEMS to know how to care about people. People that have mental-health issues are hard to deal with. Most people don't want to stay together with them. However, keeping a whole group of these people together, just providing some cheaper or free housing doesn't really help. They may not help each other too. The most importing thing the social servic office should do is trying to help them with their issues, rather than just providing some creature comfort.

Welcome

Pretty easy, this thing.

I love google