The Sakai Labs Events page

The Sakai Lab          (in Japanese)  Dr. Tetsuya Sakai

Last updated: 14th March 2018

SIGIR Tokyo Seminar Series #1

15:10-16:10 March 30, 2018 at Waseda University Nishiwaseda Campus Room 63-05-06 (maps and directions: ENGLISH JAPANESE)


Professor Mark Sanderson (RMIT University)


Getting rid of the ten blue links


In this talk, I will first give a brief overview of the IR group at RMIT. Then I will describe the work we are doing at RMIT to change one of the commonest web pages we all look at: the Search Result Page (SERP). In our work we are looking to replace the SERP with a set of answer passages that address the users query. In the context of general web search, the problem of finding answer passages has not been explored extensively. Previous studies have found that many informational queries can be answered by a passage of text extracted from a retrieved document, relieving the user from having to read the actual document. While current passage retrieval methods that focus on topical relevance have been shown to be not effective at finding answers, the result shows that more knowledge is required to identify answers in the document.


We have been formulating the answer passage extraction problem as a summarization task. We initially used term distributions extracted from a Community Question Answering (CQA) service to generate more effective summaries of retrieved web pages. An experiment was conducted to see the benefit of using the CQA data in finding answer passages. We analyze the fraction of answers covering a set of queries, the quality of the corresponding result from the answering service, and their impact on the generated summaries. I will also talk about recent work where we re-rank retrieved passages according to the summary quality and incorporating document summarizability into the ranking function.



Mark Sanderson is a Professor at the School of Computer Science and Information Technology, RMIT University, Melbourne. He received B.Sc. (hons) and Ph.D. degrees in computer science from the University of Glasgow, Glasgow, U.K., in 1988 and 1997, respectively. Mark is an Associate Editor of ACM Transactions on the Web; and co-editor of Foundations and Trends in Information Retrieval.

Special Research Talk on Information Retrieval!

13:00-14:00 August 7, 2017 at Waseda University Nishiwaseda Campus Room 63-05-06 (maps and directions: ENGLISH JAPANESE)

Dr. Stephen Robertson (Professor Emeritus, City University / Visiting Professor, University College London):

Search: then and now

with particular reference to the web


Nowadays, we take web search engines for granted. For many people, their favourite search engine (Google or some other) is their primary or even sole entry-point to the web. Not only that it also, in some sense, is the web: what you find by searching is indistinguishable, or at least not distingushed, from the search engine itself. In this talk, I will attempt to chart how we have reached this point. To start with, I will go back before search engines or the web even existed indeed, before computers existed. Card catalogues in libraries, printed indexes, punched cards (some mechanically sorted, some used purely manually) have all played a role in how we see the search task. In the computer era, but before the internet or the web, we started exploring the idea of computer searching, particularly in relation to abstracts of scientific papers.


When the web came along, web search engines began to emerge, but they took a little longer to become mainstream, and then to discover a viable business model. But as both these things happened, a rather extraordinary series of feedback loops began to shape and mould the search experience. The most obvious loop is that between the search engine and the population of searchers. The way search engines work, as seen by us the users, has had a profound effect on our notion of what search is and how we might use it; and on the other hand, the search engines have responded to and learnt from their users, to an extraordinary extent. Other feedback loops can be indentified, one involving website designers and another advertisers, each interacting with (influencing and being influenced by) the search engines.


The consequence is that the modern search engine feels a thousand miles or years removed from its library science forebears. I will end with a novel way to think about what web search engines do.




Stephen Robertson has been researching in the field of information retrieval since 1968, and has been publishing since 1969.  He is currently retired from full-time work, but remains Professor Emeritus at City University of London, Visiting Professor at University College London, and a Life Fellow at Girton College Cambridge.  His previous employment includes five years at University College, twenty at City University, and fifteen at Microsoft Research Cambridge.  In 1981 he received a Fulbright Award and spent some months at the University of California Berkeley.  He won the Gerard Salton Award in 2000 and the Strix Award in 1998; he is an ACM Fellow.  His main areas of research have been the evaluation of IR systems, particularly evaluation metrics, and probabilistic models.  The latter led him in the early 1990s to invent the BM25 ranking function, which remains a benchmark for effective ranking of search results.

Career/Industry Talk: 日本で8人しかいないCMMI最高位レベル審査員資格取得者がキャリアを語る

18:15-19:15 April 14, 2017 at Waseda University Nishiwaseda Campus Room 63-05-06 (maps and directions: ENGLISH JAPANESE)

小林 浩 氏 (株式会社システム情報 CMMIコンサルティング室 室長): 「組織のケーパビリティ向上モデル「CMMI」の概要と、審査員資格取得に至るキャリア」










小林 浩 (Hiroshi Kobayashi)  PHOTO

株式会社システム情報 CMMIコンサルティング室 室長



 CMMI Institute認定 SCAMPI高成熟度リードアプレイザー

 Scrum Alliance認定スクラムマスター

 Project Management Professional



1991年 早稲田大学理工学部工業経営学科卒業。

1991 年〜2006 年 日本アイ・ビー・エム()


2006 年〜2011 年 アクセンチュア()

システムインテグレーション、AO(アプリケーションアウトソーシング)の分野で、PMO メンバー、コンサルタント、AO プロセス改善グループの日本リーダーを担当。

2011 年〜 ()システム情報

プロセス改善コンサルタントとして、社内およびお客様(日本、中国)のソフトウェア開発・保守のプロセス改善支援や、CMMI の成熟度評価を実施。

Career/Industry Talk: Acroquest Technologyとは? Elasticsearchとは?

18:00-19:00 November 25, 2016 at Waseda University Nishiwaseda Campus Room 63-05-06 (maps and directions: ENGLISH JAPANESE)

樋口 慎 氏 (Acroquest Technology): 「人気急上昇中の検索エンジン「Elasticsearch」を使ったデータ分析と、半年間ベンチャー企業で働いてみての実際」


Acroquest Technologyというベンチャー企業で半年間、データサイエンティストとして働いてきた実感を話すとともに、近年人気急上昇中の検索エンジン「Elasticsearch」について紹介します。データ分析・情報検索の分野に興味がある学生、就活を控えている学生に向けて面白い話ができればと考えています。


樋口 慎 PHOTO

2016年 早稲田大学基幹理工学部 酒井研究室卒業

Acroquest Technology株式会社 エンジニア






JJUG CCC 2016 spring Data Analytics Showcase elasticsearch勉強会 JJUG CCC 2016 fall

Career Talk: Oculus/Facebook (Pittsburgh) の白鳥貴亮氏緊急来日! 日中米を渡り歩く若手研究者のキャリアパスを直撃!

18:00-19:00 June 24, 2016 at Waseda University Nishiwaseda Campus Room 63-05-06 (maps and directions: ENGLISH JAPANESE)

白鳥貴亮 Dr. Takaaki Shiratori PHOTO



そのカーネギーメロン大学、Disney Research Pittsburghにて博士研究員、Microsoft Research Asiaにて研究員、現在FacebookOculus Research Pittsburghにて研究員。コンピュータグラフィクス、特にキャラクタアニメーションの研究に従事。

Research Talks on Information Retrieval!

16:30-18:30 June 17, 2016 at Waseda University Nishiwaseda Campus Room 63-05-06 (maps and directions: ENGLISH JAPANESE)

惇志氏(東京工業大学): 「文書構造を利用した情報検索」

近年爆発的に増加傾向にあるモバイル端末からの情報検索においては,ディスプレイサイズや通信量の観点から,従来から行われてきた文書単位の情報検索は適切とは言えません.私は過去に XML 情報検索 (部分文書検索) と呼ばれるアプローチによって,文書構造を利用しつつ,文書から要点のみを抽出する研究に従事してきました.本講演では,その概要と,NTCIR-12 MobileClick-2 への取り組みを中心にお話させて頂きます.


Cheng Luo (Tsinghua University): How Time Flies: the User Perceived Time during Web Search

Time plays an essential role in multiple areas of Information Retrieval (IR) studies such as search evaluation, user behavior analysis, freshness based result ranking and query understanding. Especially, in search evaluation studies, time is usually adopted as a measure to quantify users' efforts in search process. Psychological studies have reported that the time perception of human beings can be affected by many stimuli, such as attention and motivation, which are closely related with many cognitive factors in search scenario. Considering the fact that users' search experiences are affected by their subjective feelings of time, instead of the objective time measured by timing devices, it is necessary to look into the different factors that have impacts on search users' perception of time.  In this talk, I would like to introduce our work about the user perceived time in Web search environment, especially the impacts of temporal relevance and document relevance.


Dr. Atsushi Keyaki PHOTO

東京工業大学 情報理工学院 情報工学コース 助教

2009年 同志社大学 文化情報学部 文化情報学科 卒業

2011年 同志社大学 大学院文化情報学研究科 博士課程 (前期課程) 修了

2014年 奈良先端科学技術大学院大学 情報科学研究科 博士後期課程 修了.博士 (工学)

2014-2016年 東京工業大学 情報理工学研究科 計算工学専攻 助教

2016年 東京工業大学 情報理工学院 情報工学コース 助教 現在に至る




Mr. Cheng Luo (PHOTO) is a Ph.D student from Tsinghua University. He received a bachelor's degree from Tsinghua University in 2012. His research interests include user behavior analysis and evluation in Web search. In 2014 and 2015, he served as a research assistant at at NExT Search Centre at NUS.  Now he is a visiting research fellow at RSL, Waseda University.  

Research Talk on Natural Language Processing!

16:30-17:30 June 13, 2016 at Waseda University Nishiwaseda Campus Room 63-05-26 (maps and directions: ENGLISH JAPANESE)


Dr. Pontus Stenetorp (University College London): Natural Language Processing: History, motivations, and what the near future may hold for intelligent machines


Natural Language Processing (NLP) is a sub-field of Artificial Intelligence (AI) that focuses on the interaction between computers and human language.  Over the last few years, NLP has received an ever-increasing amount of attention from the AI research community, with several notable figures in AI stating that they believe that NLP will be the area where we can expect to see significant advances being made over the next five years.  In this talk I will outline the motivations of the field, its history, and recent move towards end-to-end (Deep Learning) models.  I will then move to speculate about future directions within the field, relating this in part to my own research on unsupervised learning from unannotated text, constructing online word association games to construct word definitions to improve NLP at a massive scale, and learning parametrised generators to allow learning with minimal human supervision and without strong model constraints.  The talk assumes no prior familiarity with NLP and I will strive to explain all mathematical concepts based on intuitions, but some familiarity with linear algebra, analysis, and vector calculus can be helpful.


Pontus Stenetorp (PHOTO) is a Research Associate at University College London (UCL), whose research mainly lies within the domain of Natural Language Processing (NLP) and Machine Learning (ML).  He is one of the creators of the widely-adopted annotation and visualisation tool brat and since 2012 he has worked on and published research regarding representation learning for NLP.  His current research focuses on end-to-end models that learns with a minimal amount of human supervision with a particular focus on allowing computers to pass real-world exams and is supported by the Paul G Allen Family Foundation.

Industry Talk: Yahoo! JAPAN研究所所長に聞く

16:30-18:00 May 28, 2015 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions: ENGLISH JAPANESE)


田島玲 氏(Yahoo! JAPAN): Yahoo! JAPANにおけるデータ利活用


Web業界では、サービスの提供とともに日々大量のデータが産みだされており、それを最先端の技術と組み合わせてサービスに活かすことが価値向上の原動力となっています。本講演では、現在約100種類のサービスを提供しているYahoo! JAPANがどのようなデータ処理基盤を持ち、どのように利活用しているのかについて技術解説や事例を交えて紹介します。


Dr. Akira Tajima PHOTO

2011-  ヤフー(株)。20127月より Yahoo! JAPAN研究所 所長

2005-2010年 日本アイ・ビー・エム(株)東京基礎研究所 数理科学チームのリード

2002-2005 A.T.カーニー(戦略系コンサルティングファーム) コンサルタント

1992-2002年 日本アイ・ビー・エム(株)東京基礎研究所 研究員

20003月 東京大学大学院理学系研究科情報科学専攻。博士(理学)


Research and Career Talks: IBM東京基礎研究所で活躍する女性研究者たち

16:00-17:40 May 14, 2015 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions: ENGLISH JAPANESE)


榎美紀 氏 (IBM Research - Tokyo)





村上明子 氏 (IBM Research - Tokyo)




Miki Enoki PHOTO


Research interests

    Data Access Technology

    Performance Innovation Lab.

        Java Performance Analysis

    Cloud Computing

    Social Media Analysis



    2005年 お茶の水女子大学理学部情報科学科 卒業

    2007年 お茶の水女子大学人間文化研究科数理・情報科学専攻 博士前期課程修了(理学)

    2013年 お茶の水女子大学人間文化創成科学研究科理学専攻 博士後期課程入学





Akiko Murakami PHOTO




2012年にIBMが公開したGTO (Global Technology Outlook)のトピックのひとつであるResilient Business and Society の提案メンバーでもあり、2012年にはResilient Engineeringグループの立ち上げにも参加しました。現在、コグニティブ・コンピューティングのナレッジインフラストラクチャーグループにて、災害やリスクに強い社会を作るためにソーシャルやオープンデータ、リンクデータをどう分析をどう分析し生かすかについて研究しています。











    2002年〜2003: 東京大学情報理工学研究科 受託研究員

    2007年〜: 東京大学大学院 学際情報学府 博士課程 (20133月単位取得満期退学)

Career Talks: マイクロソフトインターン経験者の活躍Part II (プログラミングコンテストでも活躍していたお二人が集結!)

16:30-18:30 December 17, 2014 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions: ENGLISH JAPANESE)


秋葉拓哉氏 (東京大学): プログラミングコンテスト好きを「こじらせた?」アルゴリズムの研究




相川直視氏 (Wantedly): 研究・大企業・スタートアップ.個のレベルで最もインパクトを出すための戦略実践比較





秋葉拓哉 PHOTO
2011年 東京大学理学部情報科学科 卒業
年 東京大学大学院情報理工学系研究科コンピュータ科学専攻 修士課程 修了
年 東京大学大学院情報理工学系研究科コンピュータ科学専攻 博士課程 進学
日本情報オリンピック 2006 優勝,ACM-ICPC 2012 世界大会 銅メダル,ICFP-PC 2013


相川直視 PHOTO

2009年 早稲田大学理工学部 コンピュータネットワーク工学科 卒業

2011年 早稲田大学理工学研究科 情報理工学専攻 修士課程 修了

20114月 グーグル株式会社 ソフトウェアエンジニア

20126月 ウォンテッドリー株式会社 リードエンジニア


TREC Comes to Waseda: あの評価型会議の総元締めが早稲田に!    

16:30-17:30 December 12, 2014 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions)


Dr Ian Soboroff (NIST): TREC and TAC: community-based evaluations in search and NLP


TREC, the Text Retrieval Conference, has been driving the state of the art in search technology research since 1991.  TAC has filled the same role for natural language processing since 2008.  These activities leverage the collaborative energy of a community of researchers to focus on challenge problems, define them, figure out how to measure them, build datasets for them, and provide a forum to share the resulting research.  In this talk, I will talk about the activities in TREC and TAC in 2014 and plans for 2015.


Dr. Ian Soboroff (PHOTO) is a computer scientist and leader of the Retrieval Group at the National Institute of  Standards and Technology (NIST). The Retrieval Group organizes the Text REtrieval Conference (TREC), the Text Analysis Conference (TAC), and the TREC Video Retrieval Evaluation (TRECVID).  These are all large, community-based research workshops that drive the state-of-the-art in information retrieval, video search, web search, text summarization and other areas of information access.  He has co-authored many publications in information retrieval evaluation, test collection building, text filtering, collaborative filtering, and intelligent software agents. His current research interests include building test collections for social media environments and nontraditional retrieval tasks.

Industry Talk: Noahs Ark Lab of Huawei Technologies (香港の「ノアの箱舟研究所」って? Chief Scientistに聞いてみよう! 彼は日本語ペラペラです。)

16:00-17:30 October 8, 2014 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions)


Dr Hang Li (李航): Short Text Conversation: A Small Step toward Realizing the Dream of Artificial Intelligence


Human computer conversation is regarded as one of the most difficult problems in artificial intelligence. In this talk, I will address one of its main sub-problems, referred to as short text conversation (STC), in which given a message from human, the computer returns a reasonable response to the message. It is anticipated that significant progress could be made in the research on the problem with the vast amount of STC data available on social media. One simple approach to STC, at least at the first step, is to formalize it as a search problem and employ state-of-the-art information retrieval (IR) technologies to carry out the task. At Noahs Ark Lab, we are exactly taking the approach to build an STC system using learning to rank and learning to match techniques. In this talk, I will introduce some of methods which we have developed for STC recently.


Hang Li (PHOTO) is chief scientist of the Noahs Ark Lab of Huawei Technologies. He is also adjunct professors of Peking University and Nanjing University. His research areas include information retrieval, natural language processing, statistical machine learning, and data mining. He graduated from Kyoto University in 1988 and earned his PhD from the University of Tokyo in 1998. He worked at the NEC lab in Japan during 1991 and 2001, and Microsoft Research Asia during 2001 and 2012. He joined Huawei Technologies in 2012.

Research Talks: マイクロソフトインターン経験者の活躍(Part I)

13:00-14:30 June 5, 2014 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions)


馬場雪乃氏: クラウドソーシングを用いた予測モデル構築


不特定多数の人々にインターネットを介して仕事を発注する仕組み「クラウドソーシング」の利用が様々な業種で拡大している.最近では,従来機械学習の専門家によって行われていた,過去のデータから未観測の事象を予測するモデルの構築においても,クラウドソーシングの活用が始まっている.本講演では我々が行った実験を紹介し, 予測モデル構築において群衆の力が専門家を凌駕したことを示す.


加藤誠氏: エピソードの再検索における再生と再認





Dr Yukino Baba PHOTO

国立情報学研究所 ビッグデータ数理国際研究センター
/JST, ERATO, 河原林巨大グラフプロジェクト 特任助教
年東京理科大学 工学部第一部 電気工学科 卒業.
年東京大学 大学院情報理工学系研究科 創造情報学専攻 修士課程修了.
年から2014年まで 東京大学 大学院情報理工学系研究科 数理情報学専攻 特任研究員.


Dr Makoto Kato PHOTO

京都大学大学院 情報学研究科 特定助教.

2008年京都大学京都大学 工学部 情報学科 卒業.

2009年同大学大学院 情報学研究科 修士課程修了.

2012年同大学大学院 情報学研究科 博士後期課程修了.博士(情報学).



Industry Talks: Naver Corporation, Korea (LINEのあの会社!)

15:30-17:00 January 10, 2014 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions)


Dr. Inho Kang: Introduction to Naver, and Naver Search

Naver is a popular search portal in Korea, which holds a market share of over 70%. Naver launched many services like blog, café, knowledge-in (matome in japan), N-drive, and Line to meet user needs. Identifying and satisfying user need is a key issue in developing a search service. Unlike academic research, off-line evaluations may have only limited applicability. We need different approaches to deal with constantly changing data and highly interactive environment. Often accuracy can be sacrificed for other goals. In this talk, I will introduce evaluation measures that are commercially important and share real examples that Ive encountered.


Dr. Young-In Song: Naver: What makes it different? 

Comparing to other global search engines, such as Bing or Google, Naver Search has some very unique characteristics. For example, as a search engine, Naver focuses on enabling people to search and consume information efficiently. Also, as a part of information generation and sharing platform, Naver encourages people to generate new information, which will be potentially useful for other peoples information seeking. This circulation structure on information consuming and generation has made many interesting challenges, specifically on designing algorithm or strategy for developing Naver search. In my talk, Ill introduce some examples of such historical challenges and our solutions on them, and also, the problems that we are currently facing.


Young-In Song (PHOTO), a senior applied scientist of search quality lab. at Naver, Korea. He received his Ph.D degree in computer science from Korea University, Seoul in 2009. From 2009 to 2012, he was an associate researcher at Microsoft Research Asia and had worked for research on query understanding and social question answering. He joined Naver, Korea as an applied scientist in 2012, and now leading advanced search technology research team from 2013.


Inho Kang (PHOTO) is a senior manager of search quality lab, where he oversees multiple research teams including document ranking and search result unification, information quality analysis, and advanced search technology research team. He obtained Ph.D in computer science from KAIST, Korea, and joined Samsung Advanced Institute of Technology in 2004. Then, he did post-doctoral work at Language Technologies Institute of CMU from 2006 to 2007. There, he had worked for GALE (Global Autonomous Language Exploitation) project. In 2008, he joined Naver, Korea. He and his team of researchers have developed many key technologies that have been applied to Naver Search, for example, query-centric ranking algorithm based on click-modeling technique or Libra algorithm to emphasize high-quality, original documents in a search result.

2013 Latest Updates on Computer Human Interaction/ヒューマンコンピュータインタラクション最前線2013

15:30-17:10 December 13, 2013 at Waseda University Nishiwaseda Campus Room 63-420 (maps and directions)


15:30-16:20 Dr. Hitomi Tsujita: 「未来の日用品」



16:20-17:10 Dr. Koji Yatani: Embracing Data and Noise through Interactive Systems and Applications

We are surrounded by data. As sensors are embedded in various devices, the system can collect the data about users and environment from these sensors constantly. Text data on the Web can contain useful information to the user. Although these data can be huge and are usually noisy, we can discover interesting approaches which lead to new interfaces and applications by looking at the data from different perspectives. In this talk, I present a couple of demonstrations exploiting data and noise from wearable sensors and online text data. I then discuss how they have helped me broaden my research agenda. I also briefly introduce my HCI group and internship program at MSRA.


Dr. Hitomi Tsujita PHOTO




2006年情報処理推進機構 未踏ソフトウェア創造事業採択.




Dr. Koji Yatani ( PHOTO) is an Associate Researcher in Human-Computer Interaction Group at Microsoft Research Asia. He is also a Visiting Associate Professor in Graduate School of Information Science and Technology, at The University of Tokyo. His main research interests lie in Human-Computer Interaction (HCI) and its intersections with Ubiquitous Computing and Computational Linguistics. More specifically, he is interested in designing new forms of interacting with mobile devices, and developing new hardware and sensing technologies to support user interactions in mobile/ubiquitous computing environments. He is also interested in developing interactive systems and exploring new applications using computational linguistics methods.


He received B.Eng. and M.Sci. from University of Tokyo in 2003 and 2005, respectively, and his Ph.D. in Computer Science from University of Toronto in 2011. On November 2011, he joined HCI group at Microsoft Research Asia in Beijing. On October 2013, he started to work as a Visiting Associate Professor in Graduate School of Information Science and Technology, at The University of Tokyo. He received the Best Paper Award at CHI 2011, and served as a conference or program committee on major international conferences in the field of HCI, Ubiquitous computing and Haptics, including CHI, Ubicomp, UIST, MobiSys, and WHC.

The Sakai Lab          (in Japanese)  Dr. Tetsuya Sakai