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Professor |
Assistant Professor |
Assistant Professor |
- Formal language and automata;
- Term rewrite systems;
- Declarative languages;
- Formal semantics of languages;
- Computation mechanisms and modeling; and
- Discrete mathematics.
The research in this laboratory is divided into two parts:
The first part consists of the work that follows the research in the above areas. One of the most important goal of it is to provide the foundations for the education of language processing systems, programming languages, and formal language theory.
The second part is the creative study in some specific areas related to language processing systems. The research activities of this part are based on the voluntary work of each faculty member. Currently, we are working on
- Characterizations of language classes;
- Foundation and implementation of declarative programming languages, such as functional, logic and functional-logic programming;
- Operational semantics of declarative languages;
- Parallel/Distributed computation systems, such as compiler design for vector/matrix parallel computer architecture;
- Others related to language processing systems;
- Visualization techniques for abstract models; and
- Applications of random walk model.
Functional languages based on reduction have several properties such as deterministicand lazy evaluation and higher order definitions, butthey lack other useful properties such as partial data structure and logical variables. On contrary logic languages based on unification allow partial data structure and logical variables but lack deterministic and lazy evaluation aswell as higher order definitions. From this point of view it seems natural to unify both languages into one paradigm in order to obtain a language, called a functional logic language, withmore expressive power than both functional and logic languages. The members of this laboratory engage to develop an efficient operational semantics for such unified model.
It is recognized that narrowing is one of the most important mechanisms of computation, especially in functional-logic programming languages. The members of this laboratory study theoretical aspects of narrowing, extension of the notion of narrowing to higher-order narrowing, and others.
The recent parallel/distributed computation environment requires the development of a new language model and its processing model/system for such environment. To design new languages and language processing systems is the key work for the next development of the computer society and it is considered to be one of the most important subjects for this laboratory to study for establishing such models and implementing as real systems for evaluation.
Random walk model has many useful applications such as modeling the transport of molecules in physics, the locomotion of organisms in biology, and the ants behavior in its foraging. Furthermore, study of visual simulation of such systems is also conducted by the member of this laboratory.
The education on the subjects related to languages and language processing systems is also the important mission of this laboratory. The courses for undergraduate students given by the members of this laboratory include Computer Literacy II, Advanced Algorithm, Automata and Languages, Language Processing Systems, and Logics. Those for graduate students include Automata and Languages and Compilers, AdvancedAutomata and Languages, ComputationModels, Term Rewriting Systems, and Declarative Processing.
| The research and education activities in this laboratory focus on the theoretical and practical aspects related to language processing and language processing systems. In particular, our work covers the following areas. |
Refereed Journal Papers
| [okawa-01:2004] |
Takafumi Hayashi and Satoshi Okawa. Binary Array Set having a Cross-Shaped Zero-Correlation Zone. IEEE Signal Processing Letters, vol.11(4):423-426, 2004. |
| This letter introduces a new approach to the construction of a set of binary array having a zero-correlation zone(ZCZ). The proposed array set has a crossshaped ZCZ and, thus, is 1.5 times wider than that of existing ZCZ arrays. The proposed array set can be constructed from an arbirary Hadamard matrix. The proposed array can be used in applications such as arrays of sound sourses, position detection arrays, phaseed-array antennas, time-frequency coding, and spatial correlation. |
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| [okawa-02:2004] |
Takafumi Hayashi and Satoshi Okawa. A Class of Ternary Sequence Sets with a Zero-Correlation Zone. IEICE Trans. Fundamentals, E87-A(6):1591-1598, 2004. |
| A new class of ternary sequence having a zero-correlation zone(zcz), based on Hadamard matrices, is presented. The proposed sequence construction can simultaneouly generate a finite-length ternary zcz sequence set and a periodic ternary zcz sequence set. The generated finite-length ternary zcz sequence set has a zero-correlation zone for an aperiodic function. The generated periodic ternary zcz sequenceset has a zero-correlation zone for even and odd correlation functions. |
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| [okawa-03:2004] |
Satosh Okawa, Sadaki Hirose, and Pal Domosi. A Note on the Homomorphic Characterization of k-Poly-Slender Context-Free Languages. Publicationes Mathematicae (Debrecen), No. 65, supplement:591-602, 2004. |
| [okawa-04:2004] |
Takafumi Hayashi, Takao Maeda, and Satoshi Okawa. Upper Bounds of the Correlation Functions of a Class of Binary Zero-Correlation-Zone Sequences. IEICE Trans. Fundamentals, E88-A(3):791-794, 2005. |
| The present letter describes the estimation of the upper bounds of the correlation functions of a class of zero-correlation-zone sequences constructed from an arbitrary Hadamard matrix. |
Referred Proceeding Papers
| [hamada-01:2004] |
M. Hamada and K. Shiina. Performance Evaluation of Automata Simulators. In 6th ACM ITiCSE International Conference. ACM, University of Leeds, UK, 2004. |
| In this paper we focus onperformance evaluation of finite automata simulators. We developed our own simulator. We also tested two other existing simulators to find whether simulators are useful as a teaching tool in automata classes. Moreover we try to point out which simulator is more useful. |
[hamada-02:2004] |
R.Ben-Mat and M.Hamada. Letter Images Classification based on Naive Euclidean Method. In Humans and Computers 2004. University of Aizu, 2004. |
| We propose an algorithm relies on using a random field model for the example labeling. It implies a dynamic change of the label estimates during the sampling process. In addition, the proposed algorithm was evaluated empirically on artificial and real data sets. |
[okawa-05:2004] |
Satoru Watanabe and Satoshi Okawa. Extended Star Graphs are Hamiltonian Graphs. In Proceedings of the 2004 International Technical Conference on Circuits/Systems, Computers and Communications, 2004. |
| In this paper, we prove the extended star graphs are hamiltonian by giving an algorithm to construct a hamiltonian cycle of an extended star graph. The algorithm is based on the fact that they have hypercube structure and on the construction methods of hamiltonian cycles of a stargraph and a hypercube. |
Unreferred Papers
| [taro-01:2004] |
Taro Suzuki and Satoshi Okui. Transformation of XML Documents with incomplete regular expression type. InProceedings of the Third PSD workshop, pages 120-127, January 2005. |
| This paper proposes a new transformation framework of XML documents based on regular expression pattern matching. It is modeled as a version of higher-order rewrite systems, which is combined with type system with incomplete regular expression type, a restricted second-order extension of regular expression (RE) type. We demonstrate that the introduction of incomplete regular expression type allows programmers much ??exibility. We also discuss pattern matching of incomplete regular expressions. |
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| [taro-02:2004] |
Taro Suzuki and Satoshi Okui. A Rewrite System with Incomplete Regular Expression Type for Transformation of XML Documents. In The 5th workshop on Programming SIG, IPSJ, pages 1-9, March 2005. |
| This paper proposes a new framework for transformation of XML documents based on an extension of regular expression type, called incomplete regular expression type, a restricted second-order extension of regular expression type. We discuss the type theoretic issues of our framework and give some properties concerning for incomplete types. |
Grants
| [hamada-03:2004] |
M Hamada. Fukushima Prefecture Foundation for the Advancement of Science and Education, 2004-2005. |
| [taro-03:2004] |
Taro Suzuki. Grant-in-Aid for Scientific Research (C)(2), 2003-2005. |
Academic Activities
| [hamada-04:2004] |
M Hamada, 2004. Member, IEEE |
| [hamada-05:2004] |
M Hamada, 2004. Member, ACM |
| [okawa-06:2004] |
S. Okawa, 2004. serve as a reviewer of IEICE Transactions |
| [okawa-07:2004] |
S. Okawa, 2004. serve as a reviewer of the Proceedings of MCU'2004 |
| [okawa-08:2004] |
S. Okawa, 2005. serve as a reviewer of the Proceedings of DLT05 |
| [taro-04:2004] |
Taro Suzuki, 2004. reviewer of IEICE Transactions |
| [taro-05:2004] |
Taro Suzuki, 2004. Reviewer of Comupter Software |
| [taro-06:2004] |
Taro Suzuki, 2004. Member, ACM |
| [taro-07:2004] |
Taro Suzuki, 2004. Member, JSSST |
| [taro-08:2004] |
Taro Suzuki, 2004. Member, IPSJ |
Ph.D. and Other Theses
| [hamada-06:2004] |
Masashi Okuyama. Graduation Thesis: Visual Samples of Automata Generator, University of Aizu, 2005. Thesis Advisor: Hamada, M |
| [hamada-07:2004] |
Tomohiro Moriguchi. Graduation Thesis: Communication Model Simulator : Huffman and Shannon Coding, University of Aizu, 2005. Thesis Advisor: Hamada, M |
| [hamada-08:2004] |
Taku Sugai. Graduation Thesis: Communication Model Simulator : Hamming and Fano Coding, University of Aizu, 2005. Thesis Advisor: Hamada, M |
| [hamada-09:2004] |
Hayato Fukuda. Graduation Thesis: Communication Model Simulator : Arithmetic Coding, University of Aizu, 2005. Thesis Advisor: Hamada, M |
| [hamada-10:2004] |
Ben Mat. Master Thesis: Lookahead Algorithm for Selective Sampling in Active Learning for Objects based on Euclidean Distance, University of Aizu, 2005. Thesis Advisor: Hamada, M |
| [okawa-09:2004] |
Masashi Furuya. Graduation Thesis: New Results on WatsonCrick Finite Automata and Context-Free Language, University of Aizu, 2005. Thesis Advisor: S. Okawa |
| [okawa-10:2004] |
Yuji Mizuno. Graduation Thesis: A New Solution of the Firing Squad Synchronization Problem for Two Dimensional Rectangle Arrays, University of Aizu, 2005. Thesis Advisor: S. Okawa |
| [okawa-11:2004] |
Kazuto Higasi. Graduation Thesis:A Proposal of New Interconnection Network and Its Properties, University of Aizu, 2005. Thesis Advisor: S. Okawa |
| [taro-09:2004] |
Yusuke Unemoto. Master Thesis: An Optimization of JAVA Class Files based on Direct Binding, University of Aizu, 2005. Thesis Advisor: Taro Suzuki |
| [taro-10:2004] |
Masaaki Inose. Graduation Thesis: Implementation of XSLT System with Second-Order Pattern Matching, University of Aizu, 2004. Thesis Advisor: Taro Suzuki |
| [taro-11:2004] |
Daisuke Niida. Graduation Thesis: Implementation of Board Game Programs in Haskell, University of Aizu, 2005. Thesis Advisor: Taro Suzuki |
| [taro-12:2004] |
Takashi Wakamatsu. Graduation Thesis: Implementation of CORBA clients in Gofer, University of Aizu, 2005. Thesis Advisor: Taro Suzuki |
| [taro-13:2004] |
Shintaro Inagaki. Graduation Thesis: Location information service for the mobile phone using transformation of G-XML by XSLT, University of Aizu, 2005. Thesis Advisor: Taro Suzuki |
| [taro-14:2004] |
Tomoyuki Kitamura. Graduation Thesis: AnAlgorithm for Second-Order Pattern Matching Problems without Lambda-Abstraction, University of Aizu, 2005. Thesis Advisor: Taro Suzuki |
Others
| [hamada-11:2004] |
M Hamada. Reviewer for the ACM SIGCSE Bulletin and SIGCSE conferences |
| [hamada-12:2004] |
M Hamada. Reviewer for the ACM ITiCSE |
| [hamada-13:2004] |
M Hamada. Reviewer for the ICNC'05 and FSKD'05 International conferences |
