「華人戴明學院」是戴明哲學的學習共同體 ,致力於淵博型智識系統的研究、推廣和運用。 The purpose of this blog is to advance the ideas and ideals of W. Edwards Deming.

2020年9月23日 星期三

“A Million Random Digits”—contain mysterious errors. New Method of Producing Random Numbers. A Million Random Digits THE SEQUEL: with Perfectly Uniform Distribution. Why are countries creating public random number generators?


“Soul crushing.” An engineer discovers that numbers in a revered 65-year-old book—“A Million Random Digits”—contain mysterious errors.

2020.9.25

***

Why are countries creating public random number generators?

In Chile, politicians resent the Comptroller General, which audits government officials to prevent corruption. The audits are supposed to be random—but scrutinized officials sometimes complain about unfair targeting. "The auditors have to convince the public they're doing their work honestly," says Alejandro Hevia, a computer scientist at the University of Chile in Santiago. Along with researchers around the world, he is developing technology that could persuade critics that audits are truly random: public random number generators.
On 10 July, Hevia's team will unveil an online random number service. Later in July, the U.S. National Institute of Standards and Technology (NIST) will launch its Randomness Beacon as a permanent service, upgrading a pilot program that began in 2013. Brazil, too, is planning a beacon, by the end of 2019. All aim to improve on commercial random number generators, not only by being free, but by generating the random numbers through transparent protocols and permanently archiving them. The services could benefit everyday applications such as cryptography and lotteries—and also research. Some scientific simulation methods rely on random numbers, and clinicians could use them in drug trials to fairly assign who gets a treatment or placebo.
"We want to put randomness on the internet for people to use in whatever way they can find," says Rene Peralta, a computer scientist at NIST in Gaithersburg, Maryland, who leads the U.S. effort. "I think of it as digital infrastructure."

***2016.5.29

A Million Random Digits THE SEQUEL: with Perfectly Uniform Distribution [Paperback] David Dubowski (Author)
Finally, after 56 years the saga continues! Here is the next book of random numbers, pseudorandom actually, this time generated purely by mathematics. The familiar table form continues, but this set has perfectly uniform distribution. Using the Pi Crust Shuffler algorithm, a modern PC quietly churned out these 400 pages of delightful digits, ready for action in the real world. Any math lover would be delighted to receive this book as a gift! The algorithm's BASIC source code is included.


These Amazon Products Are No Joke, But the Online Reviews Are
Whether on Books About Random Digits Or Toilet Seats, Everybody's a Comedian
By MICHAEL M. PHILLIPS
What is it about the book "A Million Random Digits With 100,000 Normal Deviates" that brings out the wiseguy in people?

Smart-aleck customers are flexing their comedy muscles on Amazon, with snarky reviews and silly photos of products like banana slicers and fresh whole rabbit. WSJ's Michael M. Phillips reports.
Rand Corp.'s 600-page paperback, which delivers exactly what it promises, sells for $64.60 on Amazon.com AMZN -2.20% . Yet 400 people have submitted online Amazon reviews, most of them mocking the 60-year-old reference book for mathematicians, pollsters and lottery administrators.
"Almost perfect," said one reviewer. "But with so many terrific random digits, it's a shame they didn't sort them, to make it easier to find the one you're looking for."
Five stars from this commenter: "[T]he first thing I thought to myself after reading chapter one was, 'Look out, Harry Potter!' "
Several reviewers complained that while most of the numbers in the book appeared satisfactorily random, the pages themselves were in numerical order.
Amazon's online superstore has become the unlikely stage for 21st-century amateur comedy, where thousands of customers have submitted reviews for products ranging from the self-explanatory explanatory book "How to Avoid Huge Ships" to the Hutzler 571 banana slicer, a yellow plastic banana-shaped device that cuts bananas into even slices.
Rand said its long list of random numbers, first published in 1955, is one of its all-time best sellers. "It's a tool of some sort, but it's beyond my clear understanding," a Rand spokesman admitted.
One Amazon reviewer panned a real-life copycat publication called "A Million Random Digits THE SEQUEL: with Perfectly Uniform Distribution." "Let's be honest, 4735942 is just a rehashed version of 64004382, and 32563233 is really nothing more than 97132654 with an accent."
"We are always amazed by the creativity of our customers," said an Amazon spokeswoman...

 more: http://online.wsj.com/article/SB10001424127887323528404578454763919379102.html?mod=djemITPE_h


-----

New Method of Producing Random Numbers Could Improve ...

news.utexas.edu/2016/.../computer-science-breakthrough-could-improve-cybersecurit...

May 16, 2016 - Computer science professor David Zuckerman and graduate student Eshan Chattopadhyay will present research about their method in June at ...

Academics Make Theoretical Breakthrough in Random Number ...

https://threatpost.com/academics-make-theoretical-breakthrough...random.../118150/

May 17, 2016 - David Zuckerman, a computer science professor, and Eshan Chattopadhyay, a graduate student, published a paper in March that will be ...


隨機亂數生成演算法獲突破 五月 28, 2016 (photo by James Bowe)


本文來自於 sciencenews.org《New technique produces real randomness》,36氪翻譯

隨機亂數在軟體的應用非常廣泛。比如說抽獎程式就是一下能想到的應用之一。但是在一些更加重要的應用當中隨機亂數也發揮著重要的作用,比如加密敏感訊息、對地球天氣等複雜系統建模以及數據的公正採樣等都離不開隨機亂數。

不過電腦生成隨機亂數要比擲骰子困難得多,而且那些隨機亂數實際上並不是完全不可預測的,而是在隨機種子的基礎上結合演算法自動生成的「數」,這些「數」實際上是可複製的,算不上真正的隨機(偽隨機亂數)。所以隨機亂數的隨機性問題是基礎演算法面臨的一大難題。

不過最近德州大學的兩位電腦科學家 Eshan Chattopadhyay 和 David Zuckerman 開發出了一種改進的隨機抽樣器,這種算法只需要兩種隨機性不強的來源即可生成真正隨機的數字,被認為是基礎算法取得的一大突破。

一般的隨機算法為了提高隨機性會在演算法中引入環境的隨機性,比如滑鼠或鍵盤的位置等。電腦會採樣若干時間點的滑鼠位置然後轉化為一串數字。但這仍然算不上真正的隨機,比如前一刻滑鼠位置如果是在螢幕左側的話,下一刻滑鼠跑到右側的可能性是很低的。因此這樣生成的隨機亂數序列仍然具有相關性的,或者是可能會偏向特定值的。也就是說,這種隨機性還是很弱。

而隨機抽取器則是通過這些隨機性較弱的來源來發掘隨機性。用 MIT 電腦科學家 Dana Moshkovitz 的話來說,隨機性是一種資源,獲取隨機性的過程就像是挖金礦一樣—先開採礦石,然後排沙篩金。

而兩位科學家的算法是對隨機抽樣器的改進。這種隨機抽取器將兩種獨立的弱隨機亂數來源組合為一個接近隨機的集合,並且只有細微偏差。然後再利用彈性函數(一種訊息組合方法)將一串數字轉化為真正的隨機位 —1 或 0。

利用彈性函數進行訊息組合可以防止偏差的出現。比方說在大選裡面,一些蓄意的投票者有可能會把結果引向想要的方向。但彈性函數可以保護誠實的投票者。因為它不是選取簡單多數,而是先把數據分成 3 組,然後選取每組中的多數,再把選出來的數分成 3 組然後再抽取每組中的多數,以此類推直到最後。這種做法使得選舉可以容忍大量盲點的存在,而在隨機亂數生成方面,這種做法可以把偏差數過濾掉。

跟以往需要接近隨機輸入的隨機抽取器相比,這種新的辦法正是通過在隨機性非常非常弱的來源當中「淘金」來挖掘真正的隨機亂數,從而實現了隨機性的實質性改進,其結果已經接近於理想情況。對於加密、複雜系統模擬等應用來說,這是一個非常好的消息。



The technical details are described in the academics’ paper “Explicit Two-Source Extractors and Resilient Functions.” The academics’ introduction of resilient functions into their new algorithm built on numerous previous works to arrive at landmark moment in theoretical computer science. Already, one other leading designer of randomness extractors, Xin Li, has built on their work to create sequences of many more random numbers.

See more at: Academics Make Theoretical Breakthrough in Random Number Generation https://wp.me/p3AjUX-uJE

2020年9月12日 星期六

兩名負責波音737 MAX飛機研發的高管為設計流程辯護。Boeing expects 737 Max crisis to cost $18.6bn. Report Defends 'Thorough Work' In Certifying Boeing 737 Max — But Suggests Changes

--2020.9.14




---2020.1.29



Boeing has placed the total cost of the 737 Max crisis at more than double its previous estimate.

Aircraft maker logged its first annual loss in more than two decades amid fallout from grounding

FT.COM

Boeing expects 737 Max crisis to cost $18.6bn


***

Report Defends 'Thorough Work' In Certifying Boeing 737 Max — But Suggests Changes


Amid difficult questions about the steps taken by Boeing and regulators, the review commissioned by the Department of Transportation largely validated the process that put the jetliner in the air.

A pair of Boeing 737 Max 8 jetliners plummeted from the sky in 2018 and 2019, killing hundreds of passengers and eventually prompting officials to ground the aircraft model worldwide — but the process that allowed the craft in the air in the first place is generally sound, according to a review commissioned by U.S. regulators.
An independent committee established by the Department of Transportation published its findings in a 68-page report Thursday. (Skip down to read the whole report.) And broadly, the group found the certification process laid out by the Federal Aviation Administration to be effective, with some changes needed for improvement.
"What we saw was a thorough work by aviation professionals," one of the two co-chairs, former Air Line Pilots Association President Lee Moak, told journalists on a conference call explaining the findings. Together with retired Air Force Gen. Darren McDew, Moak oversaw a five-member panel with a mix of transportation industry executives and former regulators.
"However," Moak added, "we saw where you could improve the system."
Among their recommendations for the FAA:
  • Extend the requirement for Safety Management Systems, or formal, structured programs for risk management. The FAA already requires them for airlines and airports, but the committee recommended applying the mandate to "design and manufacturing organizations," too.
  • Do a better job gathering, analyzing and easing access to aviation data.
  • Improve collaboration with the FAA's counterparts in other countries.
  • Reevaluate and bolster the workforce, including "an aggressive recruitment campaign to encourage students to pursue careers at the FAA."
Article continues after sponsor message


What was not among its recommendations was any significant adjustment to the FAA's Organization Designation Authorization, a program by which the agency can delegate elements of its certification process to certain approved private individuals or companies. The program drew controversy last year when lawmakers questioned how Boeing ended up being responsible for reviewing changes to its own design on the 737 Max.
"Safety experts have long raised concerns that the [ODA] program leaves the fox in charge of the henhouse," Sen. Richard Blumenthal, D-Conn., wrote in a letter to the Department of Transportation last March, just days after the FAA grounded the Max.
"In short," he added, "the staff responsible for regulating aircraft safety are answerable to the manufacturers who profit from cutting corners, not the American people who may be put at risk."
Further concern surfaced last week with the revelation that Boeing employees had mocked the FAA in internal messages and gloated about the ease with which the plane was approved. "This airplane," read one note about the craft, which would later be involved in the deaths of 346 people, "is designed by clowns who in turn are supervised by monkeys."

The mother of a victim of the Ethiopian Airlines crash, which killed scores of passengers last year, bears a sign representing the dead passengers before a congressional hearing on the Boeing 737 Max 8 back in June.
Andrew Caballero-Reynolds/AFP via Getty Images
But in its review, the panel found no evidence that the outcome of the certification process would have been different if the FAA had not delegated some of the steps.
"The FAA's delegation system is an appropriate and effective tool for conducting aircraft certification," the committee concluded in the executive summary of its report. "It relies on effective standards, oversight and communication between stakeholders."
The review isn't the first to be compiled since the aircraft was grounded. Last October, an FAA-commissioned panel known as the Joint Authorities Technical Review lambasted both the agency and Boeing for failing to properly evaluate the new automated flight control system that directly caused the crashes.
The Justice Department and Transportation Department's Office of Inspector General also are investigating the Boeing plane's certification.
The airline manufacturing giant — now helmed by CEO David Calhoun after Dennis Muilenburg stepped down from the post last month — responded to Thursday's report with gratitude and a commitment to take its findings seriously.
"We will study these recommendations closely," a company spokesperson said in a brief statement, "as we continue to work with government and industry stakeholders to enhance the certification process."
The FAA also welcomed the report's findings.
"I was pleased to see that the committee recommended we advance the use of Safety Management Systems throughout all sectors of the aviation industry," Administrator Steve Dickson said in a statement released by the FAA.
"The agency will carefully consider the committee's work, along with the recommendations identified in various investigative reports and other analyses, as we take steps to enhance our aircraft certification processes."
Read the full report

2020年9月11日 星期五

"新經濟領域" (歐洲股市):科技、軟體、半導體、電信、媒體、零售、醫療保健與製藥

 

相較於以往而言,歐洲股市看起來與科技股權重較大的納斯達克指數更像了。但表面現象可能具有欺騙性。


投資者正密切關注是否會出現一種完形轉換(Gestalt switch)。根據美銀美林(Bank of America Merrill Lynch) 8月份對基金經理的調查,投資者當時已在質疑為數不多的科技巨頭還能帶領美國股市上漲多久,並已開始將持倉轉向海外標的,尋找下一批表現出色的個股。

歐洲斯托克600指數今年以來已累計下跌12%,而標普500指數累計上漲3%。其原因在於,歐洲市場上的銀行、汽車和能源公司等“舊經濟”板塊占比較大,在歐洲斯托克600指數中,科技、電信和醫療保健等“新經濟”板塊占比僅30%左右.。而在美國股市上,這一比例超過60%。

但摩根士丹利(Morgan Stanley)的分析師最近在給客戶的一份報告中表示:“實際情況正發生變化。”在歐洲股市上,新經濟領域股票的比重正加速上升。在涵蓋範圍較窄的歐元區斯托克50指數中,科技股現在是最大的類股。對於青睞成長型股票的投資者來說,這可能成為已超買的納斯達克以外的另一個替代選項嗎?

並非如此。首先,這種以新經濟板塊為方向的調整主要源於新冠疫情危機對傳統行業類股市值的嚴重破壞。直到今年1月份,成長型股票在歐洲MSCI明晟指數中的比重多年來一直沒有變化。

歐洲市場前景真正改善的一個信號將是,該地區新經濟類股的表現增強,而非舊經濟類股的表現變差。然而,歐洲科技股2020年以來以及過去十年間的表現都遜於美國科技股。

在疫情發生之前,歐洲兩大科技巨擘——企業軟件巨頭SAP SE和半導體設備製造商艾司摩爾公司(ASML Holding NV)——的增長前景就已遠遜於Netflix Inc. (NFLX)和亞馬遜公司(Amazon.com Inc., AMZN)。新冠疫情給網購和線上娛樂消費帶來永久性提振的可能性進一步拉大了這種差距。阿姆斯特丹或許有一些前途光明的初創企業,但美國和中國的大型科技公司還不需要有太多擔心。

相較於估值可能過高的美國巨頭而言,歐洲科技公司總體來看也不便宜:美國和歐洲新經濟公司的市盈率都已經比較高了。

當然,如果投資者繼續拋售矽谷公司股票,或者尋找新冠疫苗的進程出現加速,那麼相對於美國股市而言,歐洲股市剛開始的反彈很可能會持續下去。不過,在這種情境下,推動歐洲股市上漲的將是對舊經濟板塊最終將得以喘口氣的預期,從而在客觀上再次提升舊經濟板塊的相對權重。

從長遠來看,一個地區相對於另一個地區的繁榮程度,在很大程度上取決於該地區關鍵的特長行業的增長潛力。到目前為止,歐洲最近在這方面取得的進展還只是數字層面的海市蜃樓。如果投資者需要為短期內向該地區投入更多資金找一個理由,那就是容易被炒作的歐洲科技類股走勢相對疲軟,而不是因為歐洲科技股出現了任何新的走強勢頭。



網誌存檔