There are 2 sports days every year. The sports days take places on the Yuen Wo Road Sports Ground. Besides the various types of sports competitions, there are competitions among the cheering teams. The swimming gala is held every year with the Pui Ying Secondary School. It takes place on the Hong Kong Island or Sha Tin District alternatively every two years.
Students in the school take parts in many external competitions in many fields such as music, sports, debates, writings, mathematics and other academic competitions. One of the most notable competitions is the Hang Lung Mathematics Award. The school’s HLMA team got an Honourable Mention in 2004 and a Special Commendation in 2006.
The Student Union was established in November 1994. Its election activity is held in November every year. It helps the school setting new school rules and improves students’ lives. It organises activities such as blood donation days and ball game competitions.
It is formed by some teachers, social worker and psychologist to teach students how to have a true value.
It helps students plan for their future by giving them information about different study opportunities and the world of work.
Some students may be naughty, so there are some prefects catching the naughty students.
The school library has over 20000 books available to students. Every year there are about 100 school librarians. The book borrowing system was changed from man power only into computer system in 2001. The location of it was moved to the new wing building of the school in 2005. It organises Reading Day every year.
It is made up of an IT technician and some teachers. They work together to provide the up-to-date information for the use of IT in teaching and learning. It trains the teachers and maintaining computer hardware and software. It also provide some advanced computers and facilities including digital video cameras and viewers.
There are 5 groups of extracurricular activities, including studying, services, entertainment, sports and Christian programme. They are divided into 40 clubs and activity groups.
It teaches the students about civic education. There are many activities for the students to join..
It is formed by a group of Christian teachers and Christ's Harvest Church to organize some special activities, Morning Assembly and Fellowship.
The school has good relationship with Guangzhou Pui Ying, Xiguan Pui Ying, Jiangmen Pui Ying, Taishan Pui Ying and Pui Ying Secondary School. In Canada, there is a Pui Ying Christian Services Society Pui Ying Alumni Associations can be found all over the world, such as in the USA, Canada, New Zealand, Australia, England, South Africa, Japan, Peru, Singapore, Thailand, Guangzhou, Taishan, Jiangmen and Taiwan.
Heuristic
A heuristic is a practical way to solve a problem. It is better than chance, but does not always work. A person develops a heuristic by using intelligence, experience, and common sense. Trial and error is the simplest heuristic, but one of the weakest. Rule of thumb and 'educated guesses' are other names for simple heuristics. Since a heuristic is not certain to get a result, there are always exceptions.
Sometimes heuristics are rather vague: 'look before you leap' is a guide to behaviour, but 'think about the consequences' is a bit clearer. Sometimes a heuristic is a whole set of stages. When doctors examines a patient, they go through a whole set of tests and observations. They may not find out what is wrong, but they give themselves the best chance of succeeding. This is called a diagnosis.
In computer science, a 'heuristic' is a kind of algorithm. Algorithms are written to get a good solution to a problem. A heuristic algorithm might usually find pretty good solutions, but there is no guarantee or proof that the solutions are correct. The time it takes to run the algorithm is another consideration.
Heuristics is the art of finding an adequate solution to a problem, using limited knowledge and little time. More formally, heuristics are based on experience; they can speed up the search for a solution using simple rules. A complete search may take too long, or may be too difficult to do.
In more precise terms, heuristics are strategies using readily accessible, though loosely applicable, information to control problem solving in human beings and machines.
Heuristics can be used in some fields of science, but not in others: For economics, a solution that is one percent off is often acceptable; a telescope that has an error of one degree is probably unusable if aimed at a far-away object. The same telescope pointed to the window across the street will probably tolerate this error; missing by one degree will not have a big impact on a short distance.
Heuristics can be used to estimate an answer which is then made more clear by performing an exact solution at a very small scale, perhaps to save time, money or labor on a project - for example a heuristic guess as to how much weight a bridge is expected to carry can be used to determine whether the bridge should be made of wood, stone or steel, and appropriate quantities of the needed material can be purchased while the exact design of the bridge is being completed.
However, the use of heuristics in certain very technical fields may be damaging computer science is one example. Programming a computer to perform more or less the desired actions may result in severe glitches. Therefore, computer tasks generally must be fairly exact. However, there are certain areas in which computers can calculate heuristic solutions safely for example Google's search technology relies heavily on heuristics, producing "near-miss" matches to a search query when an exact match cannot be found. This enables a user to correct for any mistakes the search produces. Example: Searching for the name "Peter Smith" and unable to find that exact name, the search engine heuristically matches "Pete Smith" instead, and the person using the search engine must decide whether Pete and Peter are the same person.
Here are some other commonly used heuristics, from Polya's 1945 book, "How to Solve It":
One example where heuristics are useful is a kind of packing problem. The problem consists of packing a number of items. There are rules that need to be respected. For example, each item has a value and a weight. The problem now is to get the most valuable items, with the least weight possible. Another instance is fitting a number of differently-sized items into a confined space, like the trunk of a car.
To get the perfect solution to the problem, all possibilities must be tried. This is often not a good option, as trying them takes a long time, and on average, half the possibilities must be tried until a solution is found. So what most people will do is to start with the biggest item, fit it in, and then try to arrange the other items around it. This will give a good solution, most of the time. There are cases however, where such a solution is very bad and another technique must be used.
Therefore, this is a heuristic solution.
Mersenne prime
In mathematics, a Mersenne number is a number that is one less than a "power of two".
A Mersenne prime is a "Mersenne number" that is a prime number. This however, is not sufficient. Many mathematicians prefer the definition of a Mersenne number where exponent "n" has to be a prime number.
For example, "31 = 2 − 1", and 5 is a prime number, so 31 is a Mersenne number; and 31 is also a Mersenne prime because it is a prime number. But the Mersenne number "2047 = 2 − 1" is not a prime because it is divisible by 89 and 23. And "2 − 1 = 15" can be shown to be composite because 4 is not prime.
Throughout modern times, the largest known prime number has very often been a Mersenne prime. Most sources restrict the term "Mersenne number" to where "n" is prime, as all Mersenne primes must be of this form as seen below.