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[Keyword] NIST(134hit)

101-120hit(134hit)

  • A Fuzzy Differential Diagnosis of Headache Applying Linear Regression Method and Fuzzy Classification

    Jeong-Yong AHN  Young-Hyun KIM  Soon-Ki KIM  

     
    LETTER-Medical Engineering

      Vol:
    E86-D No:12
      Page(s):
    2790-2793

    The fuzzy set framework can be utilized in several different approaches to modeling the diagnostic process. In this paper, we introduce two main relations between symptoms and diseases where the relations are described by intuitionistic fuzzy set data. Also, we suggest four measures for medical diagnosis. We are dealing with the preliminary diagnosis from the information of interview chart. We quantify the qualitative information based on the interview chart by dual scaling. Prototype of fuzzy diagnostic sets and the linear regression methods are established with these quantified data. These methods can be used to classify new patient's tone of diseases with certain degrees of belief and its concerned symptoms.

  • Color Image Segmentation Using a Gaussian Mixture Model and a Mean Field Annealing EM Algorithm

    Jong-Hyun PARK  Wan-Hyun CHO  Soon-Young PARK  

     
    PAPER-Image Processing, Image Pattern Recognition

      Vol:
    E86-D No:10
      Page(s):
    2240-2248

    In this paper we present an unsupervised color image segmentation algorithm based on statistical models. We have adopted the Gaussian mixture model to represent the distribution of color feature vectors. A novel deterministic annealing EM and mean field theory from statistical mechanics are used to compute the posterior probability distribution of each pixel and estimate the parameters of the Gaussian Mixture Model. We describe the noncontexture segmentation algorithm that uses a deterministic annealing approach and the contexture segmentation algorithm that uses the mean field theory. The experimental results show that the deterministic annealing EM and mean field theory provide a global optimal solution for the maximum likelihood estimators and that these algorithms can efficiently segment the real image.

  • Secure Distributed Configuration Management with Randomised Scheduling of System-Administration Tasks

    Frode EIKA SANDNES  

     
    PAPER-Algorithms and Applications

      Vol:
    E86-D No:9
      Page(s):
    1601-1610

    Distributed configuration management involves maintaining a set of distributed storage and processing resources in such a way that they serve a community of users fairly, promptly, reliably and securely. Security has recently received much attention due to the general anxiety of hacking. Parallel computing systems such as clusters of workstations are no exception to this threat. This paper discusses experiments that measure the effect of employing randomisation in the scheduling of interdependent user and management tasks onto a distributed system such as clusters of workstations. Two attributes are investigated, namely performance and security. Performance is usually the prime objective in task scheduling. In this work the scheduling problem is viewed as a multi-objective optimisation problem where there is a subtle balance between efficient schedules and security. A schedule is secure if it is not vulnerable to malicious acts or inadvertent human errors. Further, the scheduling model should be hidden from unauthorised observers. The results of the study support the use of randomisation in the scheduling of tasks over an insecure network of processing nodes inhabited by malicious users.

  • On Probabilistic Scheme for Encryption Using Nonlinear Codes Mapped from 4 Linear Codes

    Chunming RONG  

     
    LETTER

      Vol:
    E86-A No:9
      Page(s):
    2248-2250

    Probabilistic encryption becomes more and more important since its ability to against chosen-ciphertext attack. Applications like online voting schemes and one-show credentials are based on probabilistic encryption. Research on good probabilistic encryptions are on going, while many good deterministic encryption schemes are already well implemented and available in many systems. To convert any deterministic encryption scheme into a probabilistic encryption scheme, a randomized media is needed to apply on the message and carry the message over as an randomized input. In this paper, nonlinear codes obtained by certain mapping from linear error-correcting codes are considered to serve as such carrying media. Binary nonlinear codes obtained by Gray mapping from 4-linear codes are discussed as example for a such scheme.

  • A Note on the Relationships among Certified Discrete Log Cryptosystems

    Eikoh CHIDA  Toshiya ITOH  Hiroki SHIZUYA  

     
    PAPER

      Vol:
    E86-A No:5
      Page(s):
    1198-1202

    The certified discrete logarithm problem modulo p prime is a discrete logarithm problem under the conditions that the complete factorization of p-1 is given and by which the base g is certified to be a primitive root mod p. For the cryptosystems based on the intractability of certified discrete logarithm problem, Sakurai-Shizuya showed that breaking the Diffie-Hellman key exchange scheme reduces to breaking the Shamir 3-pass key transmission scheme with respect to the expected polynomial-time Turing reducibility. In this paper, we show that we can remove randomness from the reduction above, and replace the reducibility with the polynomial-time many-one. Since the converse reduction is known to hold with respect to the polynomial-time many-one reducibility, our result gives a stronger evidence for that the two schemes are completely equivalent as certified discrete log cryptosystems.

  • On Robust and Nonblocking Supervisor for Nondeterministic Discrete Event Systems

    Seong-Jin PARK  Jong-Tae LIM  

     
    LETTER-Theory of Automata, Formal Language Theory

      Vol:
    E86-D No:2
      Page(s):
    330-333

    For an uncertain discrete event system (DES) modeled as a set of some possible nondeterministic automata, we address robust supervisory control problems. Based on language models, this paper presents the existence conditions of a robust nonblocking (RN) supervisor that guarantees the absence of blocked states in a closed-loop system. We show that an RN supervisor achieves both a given language specification and the nonblocking characteristics of any nondeterministic automata of the set.

  • A Note on Realtime One-Way Alternating and Deterministic Multi-Counter Automata

    Tsunehiro YOSHINAGA  Katsushi INOUE  

     
    LETTER

      Vol:
    E85-D No:2
      Page(s):
    346-349

    This paper investigates the accepting powers of one-way alternating and deterministic multi-counter automata operating in realtime. We partially solve the open problem posed in [4], and show that for each k1, there is a language accepted by a realtime one-way deterministic (k+3)-counter automaton, but not accepted by any realtime one-way alternating k-counter automaton.

  • On the Power of Non-deterministic Quantum Finite Automata

    Masaki NAKANISHI  Takao INDOH  Kiyoharu HAMAGUCHI  Toshinobu KASHIWABARA  

     
    PAPER

      Vol:
    E85-D No:2
      Page(s):
    327-332

    The class NQP was proposed as the class of problems that are solvable by non-deterministic quantum Turing machines in polynomial time. In this paper, we introduce non-deterministic quantum finite automata in which the same non-determinism as in non-deterministic quantum Turing machines is applied. We compare non-deterministic quantum finite automata with the classical counterparts, and show that (unlike the case of classical finite automata) the class of languages recognizable by non-deterministic quantum finite automata properly contains the class of all regular languages.

  • A New Approach to Deterministic Execution Testing for Concurrent Programs

    In Sang CHUNG  Byeong Man KIM  

     
    PAPER-Software Engineering

      Vol:
    E84-D No:12
      Page(s):
    1756-1766

    Deterministic execution testing has been considered a promising way for concurrent program testing because of its ability to replay a program's execution. Since, however, deterministic execution requires that a synchronization event sequence to be replayed be feasible and valid, it is not directly applicable to a situation in which synchronization sequences, being valid but infeasible, are taken into account. Resolving this problem is very important because a program may still meet its specification although the feasibility of all valid sequences is not satisfied. In this paper, we present a new approach to deterministic execution for testing concurrent systems. The proposed approach makes use of the notion of event independence and constructs an automation which accepts all the sequences semantically equivalent to a given event sequence to be replayed. Consequently, we can allow a program to be executed according to event sequences other than the given (possible infeasible) sequence if they can be accepted by the automation.

  • Long Memory Behavior for Simulated Chaotic Time Series

    Dominique GUEGAN  

     
    PAPER-Chaos & Dynamics

      Vol:
    E84-A No:9
      Page(s):
    2145-2154

    Currently the long memory behavior is associated to stochastic processes. It can be modeled by different models such like the FARIMA processes, the k-factors GARMA processes or the fractal Brownian motion. On the other side, chaotic systems characterized by sensitivity to initial conditions and existence of an attractor are generally assumed to be close in their behavior to random white noise. Here we show why we can adjust a long memory process to well known chaotic systems defined in dimension one or in higher dimension. Using this new approach permits to characterize in another way the invariant measures associated to chaotic systems and to propose a way to make long term predictions: two properties which find applications in a lot of applied fields.

  • Uniquely Parallel Parsable Unification Grammars

    Jia LEE  Kenichi MORITA  

     
    PAPER

      Vol:
    E84-D No:1
      Page(s):
    21-27

    A uniquely parsable unification grammar (UPUG) is a formal grammar with the following features: (1) parsing is performed without backtracking, and (2) each nonterminal symbol can have arguments, and derivation and parsing processes accompany unification of terms as in Prolog (or logic programming). We newly introduce a uniquely parallel parsable unification grammar (UPPUG) by extending the framework of a UPUG so that parallel parsing is also possible. We show that, in UPPUG, parsing can be done without backtracking in both cases of parallel and sequential reductions. We give examples of UPPUGs where a given input string can be parsed in sublinear number of steps of the length of the input by parallel reduction.

  • Normal Forms for Uniquely Parsable Grammar Classes Forming the Deterministic Chomsky Hierarchy

    Jia LEE  Kenichi MORITA  

     
    PAPER-Theory of Automata, Formal Language Theory

      Vol:
    E83-D No:11
      Page(s):
    1917-1923

    A uniquely parsable grammar (UPG) introduced by Morita et al. is a kind of generative grammar, in which parsing can be performed without backtracking. It is known that UPGs and their three subclasses form the "deterministic Chomsky hierarchy. " In this paper, we introduce three kinds of normal forms for UPGs, i.e., Type-0, Type-1 and Type-2 UPGs by restricting the forms of rules to very simple ones. We show that the upper three classes in the deterministic Chomsky hierarchy can be exactly characterized by the three types of UPGs.

  • Nonblocking Supervisory Control of Nondeterministic Systems Based on Multiple Deterministic Model Approach

    Seong-Jin PARK  Jong-Tae LIM  

     
    LETTER-Theory of Automata, Formal Language Theory

      Vol:
    E83-D No:5
      Page(s):
    1177-1180

    This paper presents a framework for the nonblocking supervisory control of nondeterministic discrete event systems (DESs) using multiple deterministic model. Necessary and sufficient conditions for the existence of a multiple model nonblocking supervisor are obtained for a multiple deterministic model. We show that a multiple model nonblocking supervisor guarantees the nonblockingness of an original nondeterministic system.

  • An Intelligent Multipath Propagation Prediction Model Using Circular Representation in Microcell Design

    Sangho LEE  Hanseok KO  

     
    PAPER-Antenna and Propagation

      Vol:
    E83-B No:4
      Page(s):
    827-837

    This paper focuses on introducing a highly efficient data structure that effectively captures the multipath phenomenon needed for accurate propagation modeling and fast propagation prediction. We propose a new object representation procedure called circular representation (CR) of microwave masking objects such as buildings, to improve over the conventional vector representation (VR) form in fast ray tracing. The proposed CR encapsulates a building with a circle represented by a center point and radius. In this configuration, the CR essentially functions as the basic building block for higher geometric structures, enhancing the efficiency more than when VR is used alone. Only one CR is needed to represent one building while several wall vectors are required in VR. As a result, a significant computational reduction can be achieved in ray tracing by the proposed method. Our aim is to show CR as a solution to achieving efficiency in data structuring for effective propagation prediction modeling. We show that the computational load is reduced by the proposed method. Further reduction is shown attainable using the hierarchical structure of CR in a deterministic propagation model, undergoing ray tracing. The simulation results indicate that the proposed CR scheme reduces the computational load proportionally to the number of potential scattering objects while its hierarchical structure achieves about 50% of computational load reduction in the hierarchical octree structure.

  • Polynomial Time Learnability of Simple Deterministic Languages from MAT and a Representative Sample

    Yasuhiro TAJIMA  Etsuji TOMITA  Mitsuo WAKATSUKI  

     
    PAPER-Theory of Automata, Formal Language Theory

      Vol:
    E83-D No:4
      Page(s):
    757-765

    We propose a learning algorithm for simple deterministic languages from queries and a priori knowledge. To the learner, a special finite subset of the target language, called a representative sample, is provided at the beginning and two types of queries, equivalence queries and membership queries, are available. This learning algorithm constructs nonterminals of a hypothesis grammar based on Ishizaka(1990)'s idea. In Ishizaka(1990)'s algorithm, the learner makes rules as many as possible from positive counterexamples, and diagnoses wrong rules from negative counterexamples. In contrast, our algorithm guesses a simple deterministic grammar and diagnoses them using positive and negative counterexamples based on Angluin(1987)'s algorithm.

  • Two Discrete Log Algorithms for Super-Anomalous Elliptic Curves and Their Applications

    Noboru KUNIHIRO  Kenji KOYAMA  

     
    PAPER

      Vol:
    E83-A No:1
      Page(s):
    10-16

    Super-anomalous elliptic curves over a ring Z/nZ ;(n=Πi=1k piei) are defined by extending anomalous elliptic curves over a prime filed Fp. They have n points over a ring Z/nZ and pi points over Fpi for all pi. We generalize Satoh-Araki-Smart algorithm and Ruck algorithm, which solve a discrete logarithm problem over anomalous elliptic curves. We prove that a "discrete logarithm problem over super-anomalous elliptic curves" can be solved in deterministic polynomial time without knowing prime factors of n.

  • Local Allocation of End-to-End Delay Requirement

    Yen-Ping CHU  E-Hong HWANG  Kuan-Cheng LIN  Chin-Hsing CHEN  

     
    PAPER-Communication Networks and Services

      Vol:
    E82-B No:9
      Page(s):
    1380-1387

    A typical user is concerned only with the quality of service of a network on an end-to-end basis. Therefore, how end-to-end requirements are mapped into the local switching node requirements and maximum network utilization is a function of network internal design. In this paper, we address the problem of QOS allocation. We derived an optimal QOS allocation policy and decided the maximum utilization bound in a deterministic traffic model. We adopted the worst case delay bound as the end-to-end and local QOS requirement. With (σ, ρ) traffic model, we derived a formula for delay bound and the number of connections. We found that with the delay bound as the QOS metric, there is a significant difference in the performance of allocation policies. We also developed an evaluation strategy to analyze allocation policies. The numerical results for two simple network topologies: tandem network model and uneven traffic load model, compare the equal allocation policy with the optimal allocation policy and show the correctness and efficiency of QOS allocation policy.

  • A Relationship between Two-Way Deterministic One-Counter Automata and One-Pebble Deterministic Turing Machines with Sublogarithmic Space

    Tokio OKAZAKI  Lan ZHANG  Katsushi INOUE  Akira ITO  Yue WANG  

     
    LETTER-Automata,Languages and Theory of Computing

      Vol:
    E82-D No:5
      Page(s):
    999-1004

    This paper investigates a relationship between accepting powers of two-way deterministic one-counter automata and one-pebble off-line deterministic Turing machines operating in space between loglog n and log n, and shows that they are incomparable.

  • A Note on Probabilistic Rebound Automata

    Lan ZHANG  Tokio OKAZAKI  Katsushi INOUE  Akira ITO  Yue WANG  

     
    PAPER-Automata,Languages and Theory of Computing

      Vol:
    E81-D No:10
      Page(s):
    1045-1052

    This paper introduces a probabilistic rebound automaton (pra), and investigates its accepting power and closure property. We show that (1) the class of languages recognized by pra's with error probability less than 1/2, PRA, is incomparable with the class of context-free languages, (2) there is a language accepted by a two-way nondeterministic one counter automaton, but not in PRA, and (3) there is a language accepted by a deterministic one-marker rebound automaton, but not in PRA. We also show that PRA is not closed under concatenation and Kleene + .

  • A Polynomial-Time Algorithm for Checking the Inclusion for Real-Time Deterministic Restricted One-Counter Automata Which Accept by Accept Mode

    Ken HIGUCHI  Mitsuo WAKATSUKI  Etsuji TOMITA  

     
    PAPER-Automata,Languages and Theory of Computing

      Vol:
    E81-D No:1
      Page(s):
    1-11

    A deterministic pushdown automaton (dpda) having just one stack symbol is called a deterministic restricted one-counter automaton (droca). A deterministic one-counter automaton (doca) is a dpda having only one stack symbol, with the exception of a bottom-of-stack marker. The class of languages accepted by droca's which accept by final state is a proper subclass of the class of languages accepted by doca's. Valiant has proved the decidability of the equivalence problem for doca's and the undecidability of the inclusion problem for doca's. Thus the decidability of the equivalence problem for droca's is obvious. In this paper, we evaluate the upper bound of the length of the shortest input string (shortest witness) that disproves the inclusion for a pair of real-time droca's which accept by accept mode, and present a direct branching algorithm for checking the inclusion for a pair of languages accepted by these droca's. Then we show that the worst-case time complexity of our algorithm is polynomial in the size of these droca's.

101-120hit(134hit)