筑波大学では、不定期に「筑波大学組合せ論・情報理論セミナー」を開催しています。
アクセス：
つくばセンターから「筑波大学中央」または「筑波大学循環バス (右回り)」 行きに乗り、「第三エリア前」下車 。
https://www.sk.tsukuba.ac.jp/PPS/access/
https://www.sk.tsukuba.ac.jp/PPS/access/
佐野 良夫
サノ ヨシオ (Yoshio SANO)
更新日: 2022/10/19
筑波大学組合せ論・情報理論セミナー
2019/08/22
日時: 2019年8月22日 (木) 16:00-17:00
講演者: 澤 正憲（神戸大学）
講演者: 澤 正憲（神戸大学）
題目: 古典直交多項式の零点の有理性とDelsarte-
概要: ヤコビ多項式を頂点とする古典直交多項式の零点の有理性
開催場所: 筑波大学 システム情報工学研究科 社会工学専攻 C棟 3C209室
*詳細はHPからご覧いただけます。https://www.
2019/01/25
------------------------------
日時: 2019年1月25日 (金) 15:00-16:00
講演者: Prof. Xiande Zhang（University of Science and Technology of China, China）
日時: 2019年1月25日 (金) 15:00-16:00
講演者: Prof. Xiande Zhang（University of Science and Technology of China, China）
題目: Nonexistence of k-uniform states
概要: K-multipartite maximally entangled pure states or k-uniform for short, have numerous applications such as in quantum teleportation, quantum key distribution, threshold quantum secret sharing schemes, and quantum error correcting codes. Different constructions for such states have been put forward, based on graph states, MDS codes, and combinatorial designs. However, for many cases it is still unknown whether or not a k-uniform state exists. In this talk, we present our recent work on the nonexistence of k-uniform state.
Personal Information: Please see http://staff.ustc.edu.cn/~
------------------------------
日時: 2019年1月25日 (金) 16:00-17:00
講演者: Prof. Rencheng Song（Hefei University of Technology, China)
講演者: Prof. Rencheng Song（Hefei University of Technology, China)
題目: Some recent progresses of biomedical signal processing and imaging with deep neural network
概要: Deep learning (DL) techniques have had a profound impact on computer vision, image analysis and natural language processing applications. DL provides a powerful tool to build a universal mapping between the user-designed input and output with neural networks. In recent years, researchers have paid great efforts to study the DL methods from various perspectives. In this talk, we will review some recent progresses of applying DL methods to biomedical signal processing and imaging problems. Particularly, we will talk about the remote photoplethysmography (rPPG) technique, a contactless video-based heart rate monitoring method and the real-time inverse scattering technique, which detects the hidden target using electromagnetic waves. We will show how the DL methods renovate these two research areas. Some future research topics will also be discussed.
Personal Information: Prof. Rencheng Song received his B.S. degrees in Mathematics from Jilin University, Changchun, China, in 2005, and the Ph.D. degree from Zhejiang University, Hangzhou, China in 2010. He is currently an associate professor with the Department of Biomedical Engineering at Hefei University of Technology. His research interests include mainly biomedical signal processing and electromagnetic inverse problems. In particular, he is interested in remote photoplethysmography, inverse scattering and deep learning for biomedical applications.
------------------------------
2018/08/23
日時: 2018年8月23日 (木) 15:00-16:00
開催場所: 筑波大学 システム情報工学研究科 社会工学専攻 E棟 3E210室
講演者: Prof. Hung-Lin Fu（National Chiao Tung University, Taiwan）
開催場所: 筑波大学 システム情報工学研究科 社会工学専攻 E棟 3E210室
講演者: Prof. Hung-Lin Fu（National Chiao Tung University, Taiwan）
題目:
Adaptive Algorithms in Group Testing
Adaptive Algorithms in Group Testing
概要:
The notion of group search was proposed sometime in World War II. Robert Dorfman published a paper to describe such a novel idea. The purpose of the project is to weed out all syphilitic men called up for induction to the war. Testing an individual for syphilis involves drawing a blood sample and analysing the sample to determine the presence or absence of syphilis. However, testing every soldier individually would have been very costly. "Group Testing" idea was then proposed by a coworker of R. Dorfman, D. Rosenblatt.
The notion of group search was proposed sometime in World War II. Robert Dorfman published a paper to describe such a novel idea. The purpose of the project is to weed out all syphilitic men called up for induction to the war. Testing an individual for syphilis involves drawing a blood sample and analysing the sample to determine the presence or absence of syphilis. However, testing every soldier individually would have been very costly. "Group Testing" idea was then proposed by a coworker of R. Dorfman, D. Rosenblatt.
Basically there are two types of searching algorithms: Adaptive and non-adaptive. If the knowledge about the tests (positive or negative) can be adapted to decide which set of items is to be tested in next step, then the algorithm is called an adaptive algorithm. On the other hand, if all tests are designed and running simultaneously, the algorithm is non-adaptive.
In this talk, I shall introduce some of the known adaptive algorithms and then present a couple of new results we obtain recently. One of them is for the classical model, called “Quaternary splitting algorithm” and the other one deals with complex model, it is known as a “learning hidden graphs” problem.
----------------------------
----------------------------
日時: 2018年8月23日 (木) 16:00-17:00
開催場所: 筑波大学 システム情報工学研究科 社会工学専攻 E棟 3E210室
講演者: Prof. Yuan-Hsun Lo（Xiamen University, China）
開催場所: 筑波大学 システム情報工学研究科 社会工学専攻 E棟 3E210室
講演者: Prof. Yuan-Hsun Lo（Xiamen University, China）
題目:
Shift-invariant Channel Hopping Sequences for Cognitive Radio Networks
Shift-invariant Channel Hopping Sequences for Cognitive Radio Networks
概要:
In cognitive radio networks, establishing a communication link between a pair of secondary users (SUs) requires them to rendezvous on a common channel which is not occupied by primary users (PUs). Asynchronous channel hopping (CH) sequences with full degree-of-rendezvous (DoR) enable a pair of SUs to meet on every channel without requiring clock synchronization, and hence minimize rendezvous failures due to the appearance of PU signals. In this talk, we revisit the shift-invariant (SI) sequences, which is used to achieve throughput-invariant and zero-packet-loss throughput 1 for a collision channel without feedback, and generalize them to CH sequences. It shows the SI property of the new CH sequences will enjoy the smallest rendezvous-success-rate (RSR) variance in the cognitive radio networks in various collision-avoidance scenarios.
In cognitive radio networks, establishing a communication link between a pair of secondary users (SUs) requires them to rendezvous on a common channel which is not occupied by primary users (PUs). Asynchronous channel hopping (CH) sequences with full degree-of-rendezvous (DoR) enable a pair of SUs to meet on every channel without requiring clock synchronization, and hence minimize rendezvous failures due to the appearance of PU signals. In this talk, we revisit the shift-invariant (SI) sequences, which is used to achieve throughput-invariant and zero-packet-loss throughput 1 for a collision channel without feedback, and generalize them to CH sequences. It shows the SI property of the new CH sequences will enjoy the smallest rendezvous-success-rate (RSR) variance in the cognitive radio networks in various collision-avoidance scenarios.
2017/05/15
日時：2017年5月15日（月）14:00~16:20
場所：筑波大学システム情報系3E棟210号室
14:00~15:00, Richard M. Wilson, Professor Emeritus, Caltech,
Decompositions of Edge-Colored Directed Complete Graphs
Decompositions of Edge-Colored Directed Complete Graphs
15:10~15:40, Jinping Fan, PhD Student, Univ of Tsukuba,
Non-Adaptive Combinatorial Group Testing
15:50~16:20, Han Cai, Visiting PhD Student, Univ of Tsukuba,
On Constructions of Partial MDS Codes
2017/02/08
日時：2017年2月8日（水）15:30〜17:00
場所：筑波大学システム情報系3C棟209号室
講演者：城本 啓介 氏（熊本大学大学院先端科学研究部）
講演題目：
符号理論的マトロイド理論へのいざない
符号理論的マトロイド理論へのいざない
概要：
マトロイドとは、
マトロイドとは、
2016/06/07
日時：2016年6月7日15:00?16:30
場所：筑波大学システム情報系3E棟210号室
講演者：Richard M. Wilson, Professor of Mathematics, Emeritus, CalTech, USA
( http://pma.divisions.caltech.edu/people/richard-m-wilson )
( http://pma.divisions.caltech.edu/people/richard-m-wilson )
2015/12/17
日時：2015年12月17日（木）14：00～15：00
場所：筑波大学システム情報系3F棟1115号室
講演者：Professor Xun Yi, RMIT University, Australia (http://www.rmit.edu.au/contact/staff%2Dcontacts/academic%2Dstaff/y/yi%2Dprofessor%2Dxun/)
講演題目：
Practical Threshold Password Authenticated Secret Sharing (TPASS) Protocol
Practical Threshold Password Authenticated Secret Sharing (TPASS) Protocol
アブストラクト：
Threshold password-authenticated secret sharing (TPASS) protocols allow a client to secret-share a secret s among n servers and protect it with a password pw, so that the client can later recover s from any subset of t of the servers using the password pw, but so that no coalition smaller than t learns anything about s or can mount an offline dictionary attack on the password pw. Some TPASS protocols have appeared in the literature recently. The protocol by Bagherzandi et al. (CCS 2011) leaks the password if a client mistakenly executes the protocol with malicious servers. The first t-out-of-n TPASS protocol for any n > t that does not suffer from this shortcoming was given by Camenisch et al. (CRYPTO 2014). This protocol, proved to be secure in the UC framework, requires the client to involve in many communication rounds so that it becomes impractical for the client. In this paper, we present a practical TPASS protocol which is in particular efficient for the client, who only needs to send a request and receive a response. In addition, we have provided a rigorous proof of security for our protocol in the standard model.
Threshold password-authenticated secret sharing (TPASS) protocols allow a client to secret-share a secret s among n servers and protect it with a password pw, so that the client can later recover s from any subset of t of the servers using the password pw, but so that no coalition smaller than t learns anything about s or can mount an offline dictionary attack on the password pw. Some TPASS protocols have appeared in the literature recently. The protocol by Bagherzandi et al. (CCS 2011) leaks the password if a client mistakenly executes the protocol with malicious servers. The first t-out-of-n TPASS protocol for any n > t that does not suffer from this shortcoming was given by Camenisch et al. (CRYPTO 2014). This protocol, proved to be secure in the UC framework, requires the client to involve in many communication rounds so that it becomes impractical for the client. In this paper, we present a practical TPASS protocol which is in particular efficient for the client, who only needs to send a request and receive a response. In addition, we have provided a rigorous proof of security for our protocol in the standard model.
2015/07/16-17
日程：2015年7月16日（木）、17日（金）
場所：筑波大学システム情報系3C棟209号室
プログラム
7月16日（木）
10:30-12:00: 澤正憲（神戸大学） Cubature公式論入門（I）
14:00-15:00: 佐竹翔平（名古屋大学） 有向グラフに対するErdos-Renyi理論
15:30-17:00: 澤正憲（神戸大学） Cubature公式論入門（II）
18:00- （懇親会）
7月17日（金）
10:30-12:00: 澤正憲（神戸大学） Cubature公式論入門（III）
14:00-15:00: 松原和樹（中央学院大学） 組加法性を持つ組合せデザイン
15:30-17:00: 澤正憲（神戸大学） Cubature公式論入門（IV）
講演アブストラクト
「Cubature公式論入門」：
「有向グラフに対するErdos-Renyi理論」：
TBA
TBA
「組加法性を持つ組合せデザイン」：
BIBデザインの集合におい
BIBデザインの集合におい
2015/06/01
日時：2015年6月1日14：00～15：00
場所：筑波大学システム情報系3E棟210号室
講演者：Professor Jianxing Yin, Soochow University, China (E-mail: jxyin@suda.edu.cn)
講演題目：Codes of Symbol-equity and Related Discrete Structures
アブストラクト：
Power line communication (PLC) is a technology which enables the transmission of data on high voltage electric power lines. Recently, there has been a renewed interest in high-speed narrowband PLC. The code is then required to be of ``symbol-equity" in order to overcome permanent narrowband disturbance. This motivates the study of symbol-equity codes. In this talk, we discuss symbol-equity codes and their related discrete structures, including some recent research progress. The combinatorial feature of constant-composition codes of symbol-equity is also mentioned.
アブストラクト：
Power line communication (PLC) is a technology which enables the transmission of data on high voltage electric power lines. Recently, there has been a renewed interest in high-speed narrowband PLC. The code is then required to be of ``symbol-equity" in order to overcome permanent narrowband disturbance. This motivates the study of symbol-equity codes. In this talk, we discuss symbol-equity codes and their related discrete structures, including some recent research progress. The combinatorial feature of constant-composition codes of symbol-equity is also mentioned.
2013/09/03
日時：２０１３年９月３日（火）１４：００～１５：３０
場所：筑波大学システム情報系３F棟１２２２号室
講演者：Professor Huilan Chang (台湾国立高雄大学応用数学科)
講演題目：Threshold group testing with consecutive positives
アブストラクト：
ThresholdConsecutive.pdf
ThresholdConsecutive.pdf
2013/07/04
日時：２０１３年７月４日１６：３０～１８：００
場所：筑波大学システム情報系３E棟２１０号室
講演者：Professor Alexander Barg (http://www.ece.umd.edu/~abarg/、アメリカ メリーランド大学)
講演題目：
Fingerprinting problem: Basic results and some variations
Fingerprinting problem: Basic results and some variations
Abstract:
Digital fingerprinting is a technique of protecting copyrighted data against unauthorized distribution by equipping copies of the data with unique ``fingerprints'' that enable the data distributor to locate the source of pirated copies. The fingerprint design problem is difficult because users of the system may form coalitions in order to create a pirated copy of the data that obfuscates their identities.
Digital fingerprinting is a technique of protecting copyrighted data against unauthorized distribution by equipping copies of the data with unique ``fingerprints'' that enable the data distributor to locate the source of pirated copies. The fingerprint design problem is difficult because users of the system may form coalitions in order to create a pirated copy of the data that obfuscates their identities.
In the first part of the talk we give a formal definition of the problem and overview the known results related to the maximum possible number of system's users under the condition of reliable recovery of at least one of the pirates.We then focus on two versions of the main problem. The first of them relates to hierarchical fingerprinting where the system is designed to provide different levels of protection against attacking coalitions of different size. Taking inspiration from the information-theoretic problem of ``unequal error protection,'' we give lower bounds on the number of users of the system (joint work with N.P. Anthapadmanabhan, ISIT 2010).
In the second part we consider a more stringent version of the problem called codes with the identifiable parent property (IPP codes). Such codes are known to be related to various constructions of separating hash arrays, and we develop this connection to prove some exact results in the problem of IPP codes with errors or erased symbols in the fingerprint (joint work with G. Kabatiansky, IEEE Trans. Inform. Theory, February 2013).
2009/10/15
日 時 ： 2009年10月15日（木） 10:00－11:15
日 時 ： 2009年10月8日（木） 15:15－16:30
日 時 ： 2009年10月8日（木） 15:15－16:30
場 所 ： 筑波大学第三学群E棟 3E210
場 所 ： 筑波大学第三学群F棟 3F1115
講演者 ： Professor Clement Lam
[Department of Computer Science & Software Engineering, Concordia University, Canada]
演 題 ： Strongly Regular Graphs with Non-Trivial Automorphisms
アブストラクト：
Lam.pdf
2009/07/22
日 時 ： 2009年7月22日（水）
場 所 ： 筑波大学第三学群F棟 3F1122
場 所 ： 筑波大学第三学群F棟 3F1122
講演者 ： Gennian Ge [中国浙江大学理学部数学科 ]
演 題 ： Perfect Difference Families, Perfect Difference Matrices, and Related Combinatorial Structures
演 題 ： Perfect Difference Families, Perfect Difference Matrices, and Related Combinatorial Structures
時間帯 ： 10:45－12:00
講演者 ： 萩原 学 [独立行政法人産業技術総合研究所情報セキュリティセンター ]
演 題 ： ランダム符号と最小距離復号の組で作られる結託体制符号の解析
時間帯 ： 14:15－15:30
講演者 ： 原田 昌晃 [山形大学理学部数理科学科 ]
演 題 ： Extremal Type II Z_{2k}-codes
時間帯 ： 15:45－18:00