Lecture Review Week 9

Database --- This week's lecture was rather difficult to understand. What in the world is relational algebra.. Weren't algebra supposed to be some letter that represent numbers?

Anyhow, there are eight operations in relational algebra. Selection, projection, union, intersection, difference, cartesian product, natural join and renaming operator.

Projection is equivalent to the selection clause in SQL. As there could be duplicate tuples, the rows with duplicate are removed - Distinct. Projection is represented by PI (R)

Selection correspond to the Where clause. Since it always selects the whole tuple, all the tuples are distinct, thus there won't be a need for distinct keyword. Selection is represented by SIGMA(R).

Union is the combined of the different relations, removing duplicate tuple. Intersection is the duplicate tuples in the relations being considered. Set difference is the tuples that appear in the first relation but not in the second relation.

Cartesian product gives all the possible combination of the tuples between the first and the second relation. No duplicate is possible. Theta-join does a cartesian product of the two relations on some conditions given.

Natural join joins two relations with relations of the same name and projects only one of the attribute. Renaming allows attributes to be renamed, similar to the keyword -As in SQL.


Business Law --- The first lecture on Company Law. First off, the 3 types of business was introduced - Sole-proprietorship, partnership (up to 19 partners), and company (more than 19).

A company is a legal person but do not have the senses like a natural person. The two primary organs of a company are the board of directors and shareholders. The directors are people who run the company in accordance to the Companies Act. The qualification of a director is just that you have to be above 21 years old and is a natural person.


Business Correspondence --- The second Oral Presentation lecture focuses on making the talk a memorable one for the audience. Visual aids must be attractive, and must not be filled with lines and lines of words. Everything should be written in point form.

Contents must be audience centred, difficult to understand terms and abbreviations must be explained.

Use catchy phrases with memory devices and word painting techniques. Give your points in words that give the same sound - alliteration. Repeats your catchy phrase to make an impression. Make comparison using simile, metaphor. Other techniques include allusion, counterpoint, hypothesis and rhetorical question


Artificial Intelligence --- The lecture continues on Logics. To infer from first order logic, there are three ways, forward chaining, backward chaining, and resolution. Basically, I still don't understand forward and backward chaining. For resolution, it is trying to form a proof by refutation / contradiction. By adding the negation of the statement to be proven to the knowledge base, you try to derive that the statement is unsatisfiable. This will therefore prove that the statement is true.


Software Engineering --- This week's lecture basically converts state diagrams into codes and see what should be done to enforce that the states are not violated. Converting from designs to codes are usually quite intuitive and nothing much can be said about this lecture. Anyway, the test is done after the mid-term test, and I really can't concentrate well thereafter. Just hope the test is not too badly done like the other two modules.

Lecture Review Week 8

Database --- This week's lecture continued from the lecture in week 6 - domain calculus. It's quite like tuple calculus, but this deals with the columns. It takes the form of

{ <> | 3y relation(x,y)}

All variables in <> are free variables. All others are not, and they need to be quantified by an existential or universal quantifier.


Business Law --- This week is on Product Liability. It's sort of an extension of tort of negligence and and sales of goods. You will have to proof the 4 essences of negligence. There are two ways for the remedies for this. First is under negligence, the second is under a breach of contract.


Business Correspondence --- This was a fun lecture, the first for oral presentation. There are five steps in the oral presentation process. This lecture concentrated on the first three.

First, is to analyze the audience and prepare the presentation in accordance to the audience you have. Try to give the presentation in a way that will benefit the audience and things that they will be interested in. The venue and time of the presentation is also important to take into account.

Second, apply ABC. Analyze the topic, Brainstorm content ideas, Choose your information. While brainstorming, don't judge the ideas that come up, jot everything down.

Third, draft your speech. The introduction must be captivating and motivating. Get the audience attention right from the start. Use transitional phrases to order the points, have mini-summaries to stress the main points, and double mini-summaries to do transitions between speakers. Conclusion is to summarize the whole presentation. Use the same phrasing as it was used in the blueprint during introduction. Any pamphlet you wish to hand out should be done at the end of the conclusion so as not to distract the audience by letting them read the pamphlet during your presentation.


Artificial Intelligence --- One hour test which I mostly couldn't do, just as I expected. After which a short lecture to wrap up first-order logics.


Software Engineering --- It's the first lecture by the second lecturer. This week focus was on defensive programming, which simply means maintaining the constraints that you have set up during the design phase. Things like 1-1, 1-*, 0..1-*, should be enforced during the coding. It's quite intuitive to know which part of the program to start working from.

Lecture Review Week 7

Database --- Two tests in 2 hours, it's been fun.

Business Law --- It's a new topic on tort of negligence, and the tutorial question that my group will have to present is on this topic. Don't really understand the lecture much, but after reading up on the topic, this is what I think the topic is about.

To prove that someone was negligent to you, you have to show that the person owes you a duty of care. For example, when you walk on the street, you have to be careful not to walk into them, causing them injuries. While the standard of care may differs in different cases, the reasonable man test still applies for all of them, just that the man will be specialist of that particular profession that is undergoing the trial.

Apart from the duty of care, the negligence must have caused damage to the other party. This cause will also be accessed based on whether the damage is foreseeable and not too remote or far-fetched.

For defenses against negligent, there are two ways mentioned. First is that the injured party had volunteered to the risk or that he had consented the risk he is undertaking. This is a complete defense. Another is that the injured party was partly to blame for his own injury, therefore the injured party can only claimed part of the damages that the defendant is responsible for.


Business Correspondence --- The lecture was quite interesting and is on inter-cultural communication. This lecture wasn't to be tested in the exam but was still good to have.

As the topic has suggested, it's about understanding how the different cultures are like and that things that we do, other cultures will do it differently. When talking to my superior, I'll try to keep eye contact but some other culture may not as this is a sign of respect. There are just too many examples, so I shan't go into details.


Artificial Intelligence --- This lecture is on first-order logic, and it was mostly covered before in previous semesters. The AND, OR, NOT, =>, <=> and so on. But there's one part that I don't really understand is the sign '|=' which represents entail. When it's said that a knowledge base entails a statement says P i.e.

K.B. |= P,

it means that the K.B. is actually a subset of the statement P. At first, I thought that it was the other way round, but now, i think it does makes sense. The entails is saying that the statement P is implied from the knowledge base through some logics, so it's quite intuitive that P should be a bigger set or the set K.B.


Software Engineering --- This lecture is the last lecture by the first lecturer, and it concludes the design part of the module. How do we draw a state-chart? Actually, you just have to imagine in your mind how the software will work, and what the different states will be will automatically come to you. Then from this states, you go through the different ways that the state may change and draw the arrow out. Then there you have it, the state-chart.