Daily Scribble

Workload before vacation

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It always seems work is extra busy right before you are about to take a long vacation.  I will be away 3 weeks for my wedding and honey moon.  There is only 1 week of work time left before I take off.  Although I have planned the vacation many months ago and schedule all my tasks around my vacation, according to Murphy’s Law things usually won’t line up nicely as expected.  In a team work, you depends on other people’s work and other people depend on your work.  I planned my deliverable to other team members around my vacation so I won’t be the bottle neck when I am away.  Somehow everything I depends comes in late, my time ended up squeezed significantly.  If I am not going away, I could just finish my work a bit later.  However when I am going away for 3 weeks, delay is not an option.  Other people are depending on my work, if I don’t deliver, they will be sitting idle.  Luckily I take a week off before my wedding to recover form the pre-vacation work stress.

I am reading an article on business week about the ethics of taking vacations.  In the article it says some people will feel guilty for taking vacation.  They think they are stealing from the company and should work non-stop everyday.  Are they nuts?  Vacation is part of the compensation of your hard work.  Why would you feel guilty for exercising their hard earned vacation.  In a modern cooperation, any employee is replaceable.  If the work load is structured right, absents form work a few weeks should not have much impact to the company.  If you are so important that you can’t leave work for a few weeks, it implies the company will be in deep trouble without you, then why don’t you get the hefty pay raise you asked for?  Taking vacation is not only good to your mental health, it also good for you career.  The company will not know how important you are and appreciate your work until you disappear form the office.  The ideal scenario is that company can feel the pain and inconvenient of your absence, but not bad enough it things start falling apart.

生活隨筆

賭博必勝術

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今天在占占字起的blog看見了篇文章﹐談論賭博必勝術﹐已經是同一系列文章的第三篇。我初看以為是開玩笑的遊戲文章﹐賭博不可能贏受制於數學定律。想不到既然有人一本正經討論文章的必勝術是否可行﹐還正反相方洋洋數千字陳述賭海心法﹐看起來就像討論阿媽唔係女人一樣咁荒謬。

文章中所謂的必勝法很簡單﹐假定賠率是50%﹐輸了錢就雙倍加注﹐ 贏了錢就立即走人。理論上不可能也押不中﹐只要押中一舖就可以翻本。文章還事有剎介地﹐例出一些數字去支持其論點。假若你有賭本$3200﹐你第一舖買$100﹐要連輸五次才會輸清袋。連輸五次的機會率是1/32大約3%﹐即是你用$3200本金有97%機會贏$100。文章認為97%差不多等於一定贏﹐所以稱之為賭博必勝術。問題是文章忘記了計算那3%會輸的可能性﹐計算輸贏預期值的數式應該是﹕$100 * 97% – $3200 * 3% = 0。所以如果賠率是50%﹐在數學上賭博不會輸不會贏。若果有$3200本金﹐不論是用輸了加倍玩法﹐還是一舖過全部押上﹐從數學上來說是沒有分別的。現實中賭場因為有圍骰或雙紅通吃的規例﹐任何賭博的賭率也低於50%﹐所以在數學上不論如何下注法﹐賭客在沒有可能會贏錢。

在文章的回應有人說﹐認為賭錢講運氣﹐贏錢時有好運應該加注﹐輸錢時交惡運應該走人。理論上這也是不正確﹐每局下注的數目﹐是不應該受輸贏影響。賭錢不過是機會率的遊戲﹐在賭桌上根本沒有運氣這回事。每一局也是獨立事件﹐每一局輸贏的機會相同﹐與前局或後局沒有任何關連﹐那麼每局下注多少是沒有關係。若果有個賭仔輸了錢﹐認為今天運氣不好﹐明天再來翻身。其實他今天死戰到底﹐還是明天再來發財﹐在數學上是沒有分別的﹐反正每局的機會率是故定﹐並不會因為賭仔主觀的運你而改變。長賭必輸﹐不論是今天賭﹐還是明天繼續賭﹐只要再賭也就是長賭﹐分別只是輸得快還是輸得慢。

機會率中學有教會考要考﹐懂得計算機會率 ﹐就應該明白賭錢必輸的數學定理。為何還這麼多人誤信賭錢有可能贏﹖賭錢必輸應該與地球是圓一樣是明顯不過的真理。賭錢想贏只有一個方法﹐就是開賭場﹗ 當然若果不是賭純機率性的遊戲﹐而是玩講技術與對手鬥心理戰的撲克牌﹐只要技術高超要長勝也不是沒有可能。從數學上來說﹐廿一點是賭客唯一可以必勝的遊戲。不過當賭客苦練數牌的絕技贏了一大筆後﹐就會被賭場例入黑名單不許進內﹐賭場才不會笨到明知會輸也要賭。為什麼一般賭客﹐明知會輸還要賭呢﹖

Daily Scribble

Interviews

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I have been doing lots of interviews recently.  My project is half way and it is very behind in the schedule.  How do we get into this mess in the first place?  As usual it is bad management decision.  Somehow we underestimate the complexity of the chip and largely overestimate the productivity of Indian contractors.  The only way to stop the project from slipping further is adding more resource.  When we first move our operation to Indian, one of the promised advantage is we will be able to get as many engineers as we need.  Never believe any sales pitch, especially the sales pitch of Indian contracting firms.  Wipro basically runs out of qualified engineers that meets our requirement.  Indian contractors is the casue of the mess, it would be repeating the same mistake to hire more of them.  This time we are hiring N. America contractors.

The project is in pretty bad shape, so we are approved to hire 10 engineers.  To fill those positions, we have to do lots of interviews.  I guess my boss is too busy to interview all of them, so I am helping him to interview the candidates.  I did mostly phone interviews since most of the candidates are from the East Coast.  I even have an interview with someone from Israel.  I kinda act like the first line of defense, screening the qualification of the interviewees before pasting them to my boss for 2nd round interview.  My role is to preform technical interview, trying to determine whether the guy knows enough to be productive.  Since I am doing phone interview, I can’t ask very detail technical question because it may require some writing and drawing.  I found asking what challenges the candidate had in his previous project is very effectively in judging his level of expertise.  The more experience the person has, the challenge is usually more complicate.  Sitting in the other side of the table gives me new insights.  The questions asked by the Interviewer always have a certain purpose.  A successful interviewee should look beyond the factual question and try to give answer in a way that satisfies what the interviewer is looking for.

Daily Scribble

Bangalore bombing

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Last Friday, 9 bombs set off in Bangalore, killed two people and wounded over twenty people.  I never feel so close to terrorist attack.  I worked in Bangalore for two months.  My colleagues took over my tasks are still working in Bangalore.  According to the news, one of the bomb went off just outside the Forum Mall, which is right next to where I live.  When you have been to places so close to bombing, it seems quite scary.  Everyone I know in Bangalore is safe.  The unlucky souls drafted to serve the Bangalore tour of duty is now getting cold feet.  I guess they have every right to concern about their own safety.

According to the news, the bombing is carried out by a Islamic terrorist group called Indian Mujahideen.  It is a small outfit of the worldwide Muslim jihad terrorist.  It seems no one knows the political agenda of this little known terrorist group.  They are not making any request according to the news.  I don’t see any reason Indian Mujahideen to fight.  India has freedom of religion, Muslim are allow to practice their faith freely.  The Indian government is not oppressing Muslim in any mean.  On the other hand the Muslim are oppressing those who live next to their Mosque by their 5a.m. morning prayer with loudspeaker.

When Indian independent from the British Empire, the Muslim had their own country in Pakistan.  If the Indian Muslim don’t like living among the Hindu majority, they can simply move to Pakistan.  They have no right to ask for more than they deserved by threatening others who don’t share their religion.  If the Indian Muslims think they are oppressed because they are poor.  They are fighting for the wrong cause.  Believing in Muslim is probably why they are poor in the first place.  Think about how much productivity is lost in time wasted for daily prayers.  If they want to leave poverty behind, maybe they should stop reading Koran and start learning marketable skills.

Daily Scribble

Biofuel

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Fossil fuel will eventually runs out, one of the solutions to the environment problem is switch to biofuel.  Biofuel is produced by convernting plants into ethonal.  Plants is 100% renewable energy.  As long as there is land, water and sunlight, plants will grow every year.  Although biofuel is a clean energy, there are controversials about biofuel will disrupt food production.  I believed in this myth in the past and have doubt about the use of biofuel.  It turns out that is only true for 1st generation biofuel made from grains or corns.  The 2nd generation biofuel made from cellulor plants like grass or algae will have a 100 fold increase in efficiency.  We can produce enough biofuel to fill up all our gas tanks without affecting food production.  According to a news report, the effect of biofuel on food production is less than 1%.  Developed countries already waste more than 1% of food, so making biofuel should have virtually no impact on the food price.

I quoted the news in an online discussion about renewal energy and environmental problem. My view point is the Earth have more than enough energy for our consumption, only that we don’t have the technology to harvest the energy.  It contradicts with the view point of most environment people that we should simply use less energy.  I think the best way to solve the energy problem is through technology.  You can never solve the problem by conservation, it can only buy you some more time until the technology is ready.  Some people challenge the 1% number and accuse me posting misleading information.  I don’t know how the number is arrived, so I decide to work out the math myself to prove I am right.  After some research, here is the math:

US has 938 million acres of farmland (from US Dept of Agriculture website)
US use 138 billion gallon gas per year (from US Energy Statistic)
The highest efficiency of biofuel production is 15000 gallon per acre (from Wiki entry on Biofuel )
938m * 1 % * 15000 = 140.7B > 138B

Therefore, if we can produce biofuel with the most efficiency future technology, we will only need 1% of US farmland to produce enough gas for all the cars in US.  With the best technology today, we can only produce 1000 gallon per acre.  (BTW, grains, corn or soybean’s efficient is less than 200 gallon per acre.)  Biofuel is a pretty new technology, there are lots of room for improvement.  If it can follow the pattern of the Moore’s Law, 15 fold increase in a few decades is totaly feasible, at least according to the theory.