In my opinion, data science is finding right quesitons, anwering questions, solving problems, taking actions or making decisions based on analyzing related data. It is basically quantitivative or data-driven problem-solving discipline. That's why it is so important in our current century. 

One thing we should bear in mind is that data science not only focuses on answering a specific question as the normal analytics will do, but also focuses on finding the right question to answer. That's why we have the word "science" in this term. 

发信人: kkkuuu123 (kkk), 信区: Faculty

This is a  story talk about the funding pressure for fauculties. 

Could this country or world do something to help them?



发信人: kkkuuu123 (kkk), 信区: Faculty
标  题: 考虑离开这个圈子了
发信站: BBS 未名空间站 (Sun Apr 19 22:20:01 2015, 美东)

在一个公立大学工程学院AP了4年,越来越觉得想离开这个圈子。主要来自找钱的压力
,尽管对做研究还是有兴趣的。我们这里比较资源匮乏,老人们和州里的那些给钱的机
构已经有长期合作关系。虽然也不做什么研究,就靠着那点钱养一两个PHD也可以混日
子。倒是苦了我们这些小虾米们。我也不是不努力去找,而是过去一两年也见了不少人
,联系了所有都能联系的地方,但没有实质进展。越挫越勇之后,现在免得麻木无奈了
。在这里呆越久越郁闷,除了找钱之外也厌倦这里的工作和生活氛围。系里就关心你的
数目,连个seminar都没有。学校在一个什么都没有的小town,老婆找不到工作。虽然
短时间内在家带小孩没什么问题,但也不是长久之计。
心里其实很矛盾。一方面知道需要更加努力去找钱但提不起劲来,面临tenure的风险。
另一方面如果一旦tenure了,跳走的机会就更难了。看清楚了这些东东也好,跟自己当
初对于教授这个职业的期待大相径庭。也许是当初老板给自己创造了一个过于理想的状
态。今年试着跳槽,没成功。也许明年再试一次,不过已经开始申请业界工作做备胎。
觉得远离这个无止境的找钱-发文章-找钱循坏也许是好事。
在这个里发发牢骚,也看看有没有类似处境的朋友可以共勉

How Uber's Autonomous Cars Will Destroy 10 Million Jobs and Reshape the Economy by 2025



I have spent quite a bit of time lately thinking about autonomous cars, and I wanted to summarize my current thoughts and predictions. Most people – experts included – seem to think that the transition to driverless vehicles will come slowly over the coming few decades, and that large hurdles exist for widespread adoption. I believe that this is significant underestimation. Autonomous cars will be commonplace by 2025 and have a near monopoly by 2030, and the sweeping change they bring will eclipse every other innovation our society has experienced. They will cause unprecedented job loss and a fundamental restructuring of our economy, solve large portions of our environmental problems, prevent tens of thousands of deaths per year, save millions of hours with increased productivity, and create entire new industries that we cannot even imagine from our current vantage point.

The transition is already beginning to happen. Elon Musk, Tesla Motor’s CEO, says that their 2015 models will be able to self-drive 90 percent of the time.1 And the major automakers aren’t far behind – according to Bloomberg News, GM’s 2017 models will feature “technology that takes control of steering, acceleration and braking at highway speeds of 70 miles per hour or in stop-and-go congested traffic.”2 Both Google3 and Tesla4 predict that fully-autonomous cars – what Musk describes as “true autonomous driving where you could literally get in the car, go to sleep and wake up at your destination” – will be available to the public by 2020.

How it will unfold

Industry experts think that consumers will be slow to purchase autonomous cars – while this may be true, it is a mistake to assume that this will impede the transition. Morgan Stanley’s research shows that cars are driven just 4% of the time,5 which is an astonishing waste considering that the average cost of car ownership is nearly $9,000 per year.6 Next to a house, an automobile is the second most expensive asset that most people will ever buy – it is no surprise that ride sharing services like Uber and car sharing services like Zipcar are quickly gaining popularity as an alternative to car ownership. It is now more economical to use a ride sharing service if you live in a city and drive less than 10,000 miles per year.7 The impact on private car ownership is enormous: a UC-Berkeley study showed that vehicle ownership among car sharing users was cut in half.8 The car purchasers of the future will not be you and me – cars will be purchased and operated by ride sharing and car sharing companies.

And current research confirms that we would be eager to use autonomous cars if they were available. A full 60% of US adults surveyed stated that they would ride in an autonomous car9 , and nearly 32% said they would not continue to drive once an autonomous car was available instead.10  But no one is more excited than Uber – drivers take home at least 75% of every fare.11 It came as no surprise when CEO Travis Kalanick recently stated that Uber will eventually replace all of its drivers with self-driving cars.12

A Columbia University study suggested that with a fleet of just 9,000 autonomous cars, Uber could replace every taxi cab in New York City13 – passengers would wait an average of 36 seconds for a ride that costs about $0.50 per mile.14 Such convenience and low cost will make car ownership inconceivable, and autonomous, on-demand taxis – the ‘transportation cloud’ – will quickly become dominant form of transportation – displacing far more than just car ownership, it will take the majority of users away from public transportation as well. With their $41 billion valuation,15 replacing all 171,000 taxis16  in the United States is well within the realm of feasibility – at a cost of $25,000 per car, the rollout would cost a mere $4.3 billion.

Fallout

The effects of the autonomous car movement will be staggering. PricewaterhouseCoopers predicts that the number of vehicles on the road will be reduced by 99%, estimating that the fleet will fall from 245 million to just 2.4 million vehicles.17

Disruptive innovation does not take kindly to entrenched competitors – like Blockbuster, Barnes and Noble, Polaroid, and dozens more like them, it is unlikely that major automakers like General Motors, Ford, and Toyota will survive the leap. They are geared to produce millions of cars in dozens of different varieties to cater to individual taste and have far too much overhead to sustain such a dramatic decrease in sales. I think that most will be bankrupt by 2030, while startup automakers like Tesla will thrive on a smaller number of fleet sales to operators like Uber by offering standardized models with fewer options.

Ancillary industries such as the $198 billion automobile insurance market,18 $98 billion automotive finance market,19 $100 billion parking industry,20 and the $300 billion automotive aftermarket21 will collapse as demand for their services evaporates. We will see the obsolescence of rental car companies, public transportation systems, and, good riddance, parking and speeding tickets. But we will see the transformation of far more than just consumer transportation: self-driving semis, buses, earth movers, and delivery trucks will obviate the need for professional drivers and the support industries that surround them.

The Bureau of Labor Statistics lists that 884,000 people are employed in motor vehicles and parts manufacturing, and an additional 3.02 million in the dealer and maintenance network.22 Truck, bus, delivery, and taxi drivers account for nearly 6 million professional driving jobs. Virtually all of these 10 million jobs will be eliminated within 10-15 years, and this list is by no means exhaustive.

But despite the job loss and wholesale destruction of industries, eliminating the needs for car ownership will yield over $1 trillion in additional disposable income – and that is going to usher in an era of unprecedented efficiency, innovation, and job creation.

A view of the future

Morgan Stanley estimates that a 90% reduction in crashes would save nearly 30,000 lives and prevent 2.12 million injuries annually.23 Driverless cars do not need to park – vehicles cruising the street looking for parking spots account for an astounding 30% of city traffic,24 not to mention that eliminating curbside parking adds two extra lanes of capacity to many city streets. Traffic will become nonexistent, saving each US commuter 38 hours every year – nearly a full work week.25 As parking lots and garages, car dealerships, and bus stations become obsolete, tens of millions of square feet of available prime real estate will spur explosive metropolitan development.

The environmental impact of autonomous cars has the potential to reverse the trend of global warming and drastically reduce our dependence on fossil fuels. Passenger cars, SUVs, pickup trucks, and minivans account for 17.6% of greenhouse gas emissions26 – a 90% reduction of vehicles in operation would reduce our overall emissions by 15.9%. As most autonomous cars are likely to be electric, we would virtually eliminate the 134 billion of gasoline used each year in the US alone.27 And while recycling 242 million vehicles will certainly require substantial resources, the surplus of raw materials will decrease the need for mining.

But perhaps most exciting for me are the coming inventions, discoveries, and creation of entire new industries that we cannot yet imagine.

I dream of the transportation cloud: near-instantly available, point-to-point travel. Ambulances that arrive to the scene within seconds. A vehicle-to-grid distributed power system. A merging of city and suburb as commuting becomes fast and painless. Dramatically improved mobility for the disabled. On-demand rental of nearly anything you can imagine. The end of the DMV!

It is exciting to be alive, isn’t it?

sealeen

1楼 评论时间: 2015-04-09 22:08:43

我当时站在街角,看你吸了一口气,轻轻地叩开那扇门。一念间,鼻子很酸。赞一个近乎发二的勇敢^_^ 

-----------------------------------
该评论来自手机Qzone

一道高级data scientist的题


标  题: 一道高级data scientist的题,请教

发信站: BBS 未名空间站 (Wed Apr  8 19:39:36 2015, 美东)

重复丢骰子,直到点数之和大于等于某个数M。
Q1: M=10000,点数之和减去M的平均值是多少(也就是期望)?
Q2: M=10000,点数之和减掉M的标准差是多少?
Q3: M=10000,投掷骰子的平均次数是多少?
Q4: M=10000,投掷骰子次数的标准差是多少?
You roll a fair 6-sided dice iteratively until the sum of the dice rolls is 
greater than or equal to M.
Q1. What is the mean of the sum minus M when M=10000
Q2. What is the standard deviation of the sum minus M when M=10000
Q3.What is the mean of the number of rolls when M=10000
Q4. What is the standard deviation of the number of rolls when M=10000

股票的税率

发信人: han6 (周瑜), 信区: JobHunting
标  题: Re: 问下股票的税率
发信站: BBS 未名空间站 (Fri Apr  3 01:33:09 2015, 美东)

发股票的时候有三种选择
1.补税保留股票,也就是说你账上要准备x/3的钱,然拿到价值x股票的时候用这些钱加
税,所有股票保留;
2.卖掉部分股票交税,账上不必存钱,发股票时自动帮你卖掉价值x/3的股票,用卖股
票所得交税,剩下2x/3的股票留在账上;
3.卖完全部股票,顾名思义,相当于多发了x的工资,按照普通收入保税。

【 在 autumnworm (虫子,秋天的) 的大作中提到: 】
: 给的时候扣一定比例交税。假设价格x,你算是交了价格x的税。你卖的时候价格y。交
: 税是算y-x的gain,不是全价交。

Strategies and skills for mentoring


How do I find a mentor and establish a mentoring relationship?

1. Identify your mentoring needs.
2. Assess your viability as a mentee.
3. Do some research.
4. Narrow your choices.
5. Select your mentor.


From the student's perspective, how to make a productive 
. tell the mentor about what they are at and where they are planning to do.
. report progress and keep the mentors in the loop.
. summarize the meeting and clarify the points that the both sides expect and understand. 
. keep a positive attitude and open for communication. 


From the faculties perspective, how to make a successful mentorship.
. Introduce your students to others. This will encourage the students a lot.
. Inspire and motivate the student with a clear picture so that they know where they are going and feel excited about make the dream come true.
. Set up a regular meeting so that everyone standing on the same page.

回首麻省理工六年:從惶恐不安到從容不迫

惶恐不安的開始

回首七年前二月中的某一天,我收到了來自麻省理工的信。

還記得當時我點開信件的手顫抖著,也記得當時的我無法安下狂跳的心來讀完整封信,只能用掃描的方式尋找關鍵字。

反反覆覆在信上來回看了幾遍,終於在信的第一段的最後看到了-- "Congratulation!"。

是的,我錄取了麻省理工的電腦科學暨人工智慧實驗室(CSAIL)。

收到麻省理工的錄取信,是什麼樣的感覺呢?我相信每個人都不一樣,但當時我的心情,真的很複雜。更清楚地說,我當下開心了三分鐘,但接下來的我馬上被焦慮不安給淹沒。

我真的值得嗎?即使大學四年的每一天,我時時刻刻都為了這個目標而努力,但當錄取信握在我手中時,我仍然不斷懷疑,我夠好嗎?我有資格嗎

這是全世界最頂尖的麻省理工耶,我真的可以嗎?這樣惶恐不安的心情,一直伴隨著我到達美國。

剛到美國時,有幸認識一些同時被錄取的好朋友,也因為有當地學長姐的幫忙,所以在生活上適應的很快,但是在研究方面,我卻吃足了苦頭。

第一個接手的研究題目可發展性相當侷限,我整整花了一年多的時間與失敗相處,最後終於發現在一個特定的測試環境之下,我們採取的方式表現優於傳統方式。

但這不是一個灰姑娘的故事,我的研究生涯並沒有因為嘗盡種種失敗得到成功後而有轉折,反倒是因為接連失敗的關係,我的指導教授對我的能力完全不具信心。

也許是這樣的關係,我接下來一年所接觸到的研究專案,都是創新性、可延伸性低的專案。

我嘗試著藉由提出我個人認為有趣的研究方向來翻轉這樣的處境,但總是得到指導教授的冷回應。

在這樣的環境下工作,其實是非常痛苦的,心裡的煎熬更不在話下。

當時的我真的很困惑也很沮喪,我不斷地問我自己,為什麼在全世界第一流的學府,我要做這樣的研究?

這樣下去,當我有一天離開了這個學校,我真的能具有麻省理工的實力嗎?還是我只能打著麻省理工的招牌,沾這個招牌的光?

我反覆思索這個問題,然後我確切地告訴我自已:我不要沾光,我要值得這個名號後面隱含的意義。

➢充滿關鍵的轉折

終於,在要進入博士班第二年的暑假,來自同實驗室學長的一句話,讓我的研究生涯有了重要的轉折。那

位學長是我個人認為在我們組裡研究算是相當成功的學生,我跟他提了我的心情,原本以為研究順遂的學長只會安慰我幾句,沒想到學長竟跟我說,他也曾經歷過我的處境。

當時的他秉持著證明給教授看的心情,一步一步慢慢做、一步一步成功地說服教授。

學長的話給了我相當大的鼓勵,因為我認定研究最成功的學長,居然也經歷過和我相似的處境?如果學長能渡過這些挑戰,也許我也可以?

我抱著這樣的想法,開始一頭鑽入我所提出的研究計劃。

但完成計劃需要時間,而在實驗還沒有成果之前,我必須不斷地說服指導教授,請他相信我並給我機會。

這個過程,真的很孤獨,質疑的聲音不僅僅來自外界,也來自我的心裡,但我只能盡力忽略懷疑的聲音,不斷調整心態。

最後,前前後後將近半年的時間,我終於從無到有地把一個研究計劃做出來:靠自己發想研究方向、大量閱讀文獻,大量地和同學討論,思考如何設計實驗、執行實驗,用了整整一個月的時間撰寫了一篇教授看完只能修改兩個字的論文,並且說服指導教授讓我把論文投稿到最頂尖的會議。

這中間的過程,用文字帶過看似雲淡風輕,但其中著實充滿了酸甜苦辣。

那篇論文後來很幸運的被錄取了,根據我實驗室的同學做的小小追蹤,那篇論文是那次會議裡引用次數最多的五篇論文之一。

然而,我心中認定最大的收獲卻是得到了教授對我的信任。

在那次獨立執行研究專案以後,我的教授開始對我另眼看待,他開始給我機會到其他學校、會議做演講,當他受邀給演講時,也總是會介紹我的研究。

依然記得有一天當他在準備演講稿的時候,他跟我說:"I want to show them the most exciting thing here."。

➢從容不迫的達陣

我的教授開始給我大量的自由,因為有絕大部分的自主性,我可以選擇做我有熱忱的題目,因為有熱忱,所以即使研究陷入瓶頸,我也可以抱著正面的態度面對層層關卡,然後一一突破。

我不敢說我的研究帶來了多重大的突破與發現,但是,抱著好奇的心,我發現及探索了新的領域,現在實驗室裡有兩到三位研究生,延續著我的博士論文做著研究,我想這應該可以算是我對學術界做的一點小小的貢獻吧!

然而對於我個人而言,更重要的卻是,我可以沒有慚愧地對自己說,我在麻省理工紮實地走過了一遍。

回首看待在麻省理工的六年,那充滿轉折的半年扮演著關鍵的角色,因為那半年,讓我有了從零到一獨立創造的經驗,這對我後來職涯的選擇有著很深遠的影響(我婉拒了數間大型軟體公司的邀請,而選擇加入新創公司)。

在那半年裡我學到了幾件重要的事情,在這裡與大家分享:

1. 突破舒適圈:

在尋找研究方向的過程中,我大量地往外探索,看CSAIL其他領域的學生在做什麼樣的研究,思索他們的研究創新程度在什麼樣的水準,因為這樣的審視,讓我可以用更全觀的角度來引導我自己該走的方向。

此外,我也大量閱讀我所熟知領域以外的文獻來激發靈感,有問題就寫信給在CSAIL做相關研究的同學--在CSAIL最大的好處就是你的同學就是專家。

2. 獨立:

我徹底了解除了我自己之外,沒有人會承擔我的未來。教授的人生不會因為我寫不出博士論文而有改變,但是我的人生卻可能因此而陷入低潮好一陣子。

所以,我學到了,我必須主動為自己爭取。

不喜歡研究的題目,我就必須說服教授讓我換題目,而不是埋頭苦幹,希望有一天教授會突然發現這個題目缺乏發展性。

3.堅持:

我無法再強調堅持的重要性了。然而,這兩個字說起來雖然簡單,做起來卻相當困難。我自己也不能算是個毅力特別強的人,但是根據過去的經驗,我發現堅持其實有個小訣竅,那就是把大目標拆成中目標,中目標再分割成容易達到的

小目標。擁有可以容易達成的小目標相當重要,因為小目標達成時的成就感,可以形成驅使我們繼續向前源源不絕的原動力。

希望這篇文章能夠讓有心想到國外深造的學子們,一窺現實的研究生活是怎麼樣子,並且能夠在出發之前建立正確的態度。也

希望能夠帶給正踏在學術研究這條道路上的學生一些鼓勵:你會走過的--從惶恐不安到從容不迫的這條路。

(作者簡介:李佳盈,2008年自臺大電機系畢業後,即赴美深造。分別在2010年和2014年取得麻省理工碩士及博士學位。熱愛機器學習這個領域,喜歡用多樣的角度看世界,現在在舊金山打拼人生。)

- See more at: http://blog.cw.com.tw/blog/profile/62/article/2009#sthash.jnxAjO2w.dpuf