reddit 與 4chan 在新聞網路上的獨特性

在「Study finds fringe communities on Reddit and 4chan have high influence on flow of alternative news to Twitter」這邊看到的:

After analyzing millions of posts containing mainstream and alternative news shared on Twitter, Reddit and 4chan, Jeremy Blackburn, Ph.D., and collaborators found that alt-right communities within 4chan, an image-based discussion forum where users are anonymous, and Reddit, a social news aggregator where users vote up or down on posts, have a surprisingly large influence on Twitter.

依照對 reddit4chan 的描述,這兩個媒體對 Twitter 的影響,會讓我聯想到在台灣 Ptt 對各新聞媒體的影響:Ptt 是很多新聞的起點?

"Based on our findings, these smaller, fringe communities on Reddit and 4chan serve as an incubation chamber for a lot of information," said Blackburn, assistant professor of computer science in the UAB College of Arts and Sciences. "The content and talking points are refined until they finally break free and make it to larger, more mainstream communities."

真的研究應該可以看出 Ptt 的影響力?

在網頁上看 arXiv 的論文

Hacker News Daily 上看到的服務「Arxiv Vanity – Read academic papers from Arxiv as web pages」:

Arxiv Vanity renders academic papers from Arxiv as responsive web pages so you don’t have to squint at a PDF.

不過實際測試發現只有有提供 TeX 格式原始檔才有辦法轉,沒提供的就不行了...

歐盟對於盜版是否帶來傷害的研究

歐盟在 2014 年做了關於盜版與銷量的研究,結果一直被壓到最近才發表出來 (於是就大概可以猜到結論了...):「EU Piracy Report Suppression Raises Questions Over Transparency」。

“In general, the results do not show robust statistical evidence of displacement of sales by online copyright infringements,” the study notes.

甚至:

The study found that piracy had a slightly positive effect on the videogames industry, suggesting that those who play pirate games eventually become buyers of official content.

另外也描述了現有電影與 TV-series 定價策略偏高:

“Overall, the analysis indicates that for films and TV-series current prices are higher than 80 per cent of the illegal downloaders and streamers are willing to pay,” the study notes.

難怪被壓著...

關於圍棋貼目的問題...

前陣子 AlphaGo 大獲全勝後放出了五十盤自戰棋譜 (兩台 AlphaGo 自己下),其實有件事情有點出乎大家意料,而在圍棋界被一直討論。就是在這五十盤裡,黑棋與白棋的勝率比是 12:38 (中國規則,黑棋貼 7.5 目的情況),明顯白棋有強大的優勢。

這個 7.5 目指的是,由於黑棋先下 (先手優勢),所以圍的地會比較多,為了彌補白棋後下的這個缺點,一般都會設計「貼目」這個規則。

交大資工的 CGI 團隊在上個月月底發了一篇論文 (參考「CGOS Whole Period Ratings for 19x19 Board」這邊的記錄,在有參加 CGOS 的團隊裡只輸新版的 Zen),討論 value network 的新想法:「Multi-Labelled Value Networks for Computer Go」。

他們對貼目的數量做了分析:

For the training data, we label on output 𝑣𝑘 as follows. For each self-play game, first calculate territory difference 𝑛 at the end of the game. Then, based on the Chinese rule, label 1 (win) on 𝑣𝑘 for all 𝑘 < 𝑛, and -1 (lose) for all 𝑘 > 𝑛. (Note that the draw case 𝑘 = 𝑛 is ignored in this paper since the komi is not an integer normally.) For example, if black occupies 7 more points of territory than white, the 𝑘-komi game is considered a win for all 𝑘 < 7, and a loss for all 𝑘 > 7. Thus, in this case, a 7.5-komi game is a loss, and a 6.5-komi or 0.5-komi game is a win.

這個研究完全顛覆了目前職業棋手一般的理解。目前的理解是,貼 5.5 目是黑棋優勢,貼 7.5 目是白棋優勢 (所謂的大貼目時代)。

接下來應該會有更多的研究出來,圍棋界會不會反思貼目規則呢...

Google 的軟體開發

之前有不少 Google 內軟體開發的說明 (像是 2015 年的「Google Is 2 Billion Lines of Code—And It’s All in One Place」),不過這好像是第一次以 paper 的形式整理出來:「Software Engineering at Google」。

當你有一群等級超高的工程師時,軟體工程裡面一堆假設都被推翻,然後一堆工具都是客製化自己開發 (有可能是那個時間點還沒有成熟的工具,也有可能是需要大量客製化),於是就會看到各種有趣的解法... XD

拿來看看還可以,拿來抄八成會出事 XDDD

用人力就可以達到離心機的效果...

看到「This Human-Powered Paper Centrifuge Is Pure Genius」這個設計真的很巧妙... 全文刊登在 nature biomedical engineering 上:「Hand-powered ultralow-cost paper centrifuge」。

起源來自於小時候的玩具 (我也有印象,但忘記中文叫什麼了...):

Here, we report an ultralow-cost (20 cents), lightweight (2 g), human-powered paper centrifuge (which we name ‘paperfuge’) designed on the basis of a theoretical model inspired by the fundamental mechanics of an ancient whirligig (or buzzer toy; 3,300 BC).

研究後發現離心速度可以到 125000rpm:

The paperfuge achieves speeds of 125,000 r.p.m. (and equivalent centrifugal forces of 30,000 g), with theoretical limits predicting 1,000,000 r.p.m.

對於無法買昂貴醫療器材的地區,這樣就有簡單但又頗有效的離心機做檢驗...

設計資料同步問題時一定會遇到的 Conflict 解決方案

在「A Conflict-Free Replicated JSON Datatype」這邊看到有趣的東西。(arXiv 說 2016/08/18 會有一個小時的 downtime,台灣時間剛好是 2016/08/18 的 20:20 開始:「Maintenance scheduled for Aug 18 8:20 a.m. EDT」)

作者們設計這個架構是想要在 JSON 結構上找出一個演算法,在 P2P 架構上 (而不需要靠 server) 可以同步並且產生一致的結果,另外要求當 conflict 時不要掉資料:

In this paper we present an algorithm and formal semantics for a JSON data structure that automatically resolves concurrent modifications such that no updates are lost, and such that all replicas converge towards the same state.

作者提出來的想法不是很複雜,而且 merge 保留姿的方法也頗... 特別,但總是給大家一個想法,各何況很多情況下都是有 server 架構,就簡單多了...

DVD 的發行時間差異導致盜版

MPAA 資助的報告顯示 DVD 的發行時間差異導致盜版:「DVD Release Delays Boost Piracy and Hurt Sales, Study Shows」,報告在「Windows of Opportunity: The Impact of Piracy and Delayed International Availability on DVD Sales」這邊可以看到。

用真實資料計算得到:

"When we run our regressions on Spain and Italy alone, we observe a 10% drop in sales for every 10-day delay in legal availability, as compared to a 2% drop in sales for every 10-day delay in the entire sample," the paper reads.

"Our results suggest that an additional 10-day delay between the availability of digital piracy and the legitimate DVD release date in a particular country is correlated with a 2-3% reduction in DVD sales in that country," the researchers write.

時效的重要...