Yoshiaki SEKI Toshihiko YAMAKAMI Akihiro SHIMIZU
The use of computers with private networks has accelerated the electronic storage of business information in office systems. With the rapid progress in processing capability and small sizing of the computer world, private networks are going to be more intelligent. The utilization of shared information is a key issue in modern organizations, in order to increase the productivity of white-collar workers. In the CSCW research field, it is said that informal and unstructured information is important in group work contexts but difficult to locate in a large organization. Many researchers are paying particular attention to the importance of support systems for such information. These kinds of information are called Organizational memory or Group Memory. Our research focuses on knowledge propagation with private networks in the organization. This means emphasis on the process; with which organized information or the ability to use information is circulated throughout the organization. Knowledge propagation has three issues: knowledge transmission, destination locating and source locating. To cope with these issues we developed FISH, which stands for Flexible Information Sharing and Handling system. FISH was designed to provide cooperative information sharing in a group work context and to explore knowledge propagation. FISH stores fragmental information as cards with multiple keywords and content. This paper discusses a three-layered model that describes computer supported knowledge transmission. Based on this model, three issues are discussed regarding knowledge propagation. FISH and its two-year experiment are described and knowledge propagation is explored based on the results of this experiment.
In this paper, we study the knowledge tightness of zero-knowledge proofs. To this end, we present a new measure for the knowledge tightness of zero-knowledge proofs and show that if a language L has a bounded round zero-knowledge proof with knowledge tightness t(|x|) 2 - |x|-c for some c 0, then L BPP and that any language L AM has a bounded round zero-knowledge proof with knowledge tightness t(|x|) 2-2-O(|x|) under the assumption that collision intractable hash functions exist. This implies that in the case of a bounded round zero-knowledge proof for a language L BPP, the optimal knowledge tightness is "2" unless AM = BPP. In addition, we show that any language L IP has an unbounded round zero-knowledge proof with knowledge tightness t(|x|) 1.5 under the assumption that nonuniformly secure probabilistic encryptions exist.
Toshiya ITOH Tatsuhiko KAKIMOTO
In this paper, we investigate the knowledge complexity of interactive proof systems and show that (1) under the blackbox simulation, if a language L has a bounded move public coin interactive proof system with polynomially bounded knowledge complexity in the hint sense, then the language L itself has a one move interactive proof system; and (2) under the blackbox simulation, if a language L has a three move private coin interactive proof system with polynomially bounded knowledge complexity in the hint sense, then the language L itself has a one move interactive proof system. These results imply that as long as the blackbox simulation is concerned, any language L AM\MA is not allowed to have a bounded move public coin (or three move private coin) interactive proof system with polynomially bounded knowledge complexity in the hint sense unless AM = AM. In addition, we present a definite distinction between knowledge complexity in the hint sense and in the strict oracle sense, i.e., any language in AM (resp. IP) has a two (resp. unbounded) move public coin interactive proof system with polynomially bounded knowledge complexity in the strict oracle sense.
This paper describes the concepts and methodologies of the INTELLITUTOR system which is an integrated intelligent programming environment for learning programming. INTELLITUTOR attempts to work as a human programming tutor to guide a user, i.e., a student, in writing a computer program, to detect logical errors within it, and to make advices not only for fixing them but also for letting him notice his misunderstandings. The system consists of three major modules, i.e., GUIDE, ALPUS and TUTOR. GUIDE is a guided editor for easy coding, ALPUS is an algorithm-based program understander, and TUTOR is an embedded-intelligent tutoring system for programming education. The ALPUS system can infer user's intentions from buggy codes in addition to detecting logical errors by means of knowledge-based reasoning. ALPUS uses four kinds of programming knowledge: 1) knowledge on algorithms, 2) Knowledge on programming techniques, 3) Knowledge on a programming language, and 4) Knowledge on logical errors. These knowledge are organized in a hierarchical procedure graph (HPG) as a multi-use knowledge base. The knowledge on logical errors was obtained by means of cognitive experiments. The student model is built by means of the results of ALPUS and interactions between a student and the system. Teaching is done based on the student model. Because the ITS subsystem, i.e., TUTOR, is embedded within the intelligent programming environment interactions for creating the student model could be minimized. Although the current system deals with the PASCAL language, most of the knowledge is applicable to those of procedure-oriented programming languages. The INTELLITUTOR system was implemented in the frame-based knowledge engineering environment ZERO and working on a UNIX workstation for system evaluation.
Hiroki SHIZUYA Kenji KOYAMA Toshiya ITOH
This paper presents a zero-knowledge interactive protocol that demonstrates two factors a and b of a composite number n (=ab) are really known by the prover, without revealing the factors themselves. Here the factors a and b need not be primes. The security of the protocol is based on the difficulty of computing discrete logarithms modulo a large prime.
This paper gives a model to explain one phenomenon found in the process of creative concept formation, i.e. the phenomenon that people often get trapped in some state where the mental world remains nebulous and sometimes suddenly make a jump to a new concept. This phenomenon has been qualitatively explained mainly by the philosophers but there have not been models for explaining it quantitatively. Such model is necessary in a new research field to study the systems for aiding human creative activities. So far, the work on creation aid has not had theoretical background and the systems have been built based only on trial and error. The model given in this paper explains some aspects of the phenomena found in creative activities and give some suggestions for the future systems for aiding creative concept formation.
Okihiro SUGIHARA Yasuhiko HIRANO Naomichi OKAMOTO Yutaka TAKETANI
Poled polymer films doped with novel nonlinear organic materials, α-cyano unsaturated carboxylic acid (α-CUCA) derivatives, are prepared. Linear and second-order nonlinear optical properties are investigated. It is found that as the value of hyperpolarizability of the derivatives increases, the second-order nonlinear susceptibility of the film increases. Cerenkov-type second harmonic generation (SHG) of Nd: YAG laser is realized in a poled polymer waveguide doped with the α-CUCA material with a slight absorption at doubled wavelength.
Yoshinao MIZUGAKI Koji NAKAJIMA Tsutomu YAMASHITA
The threshold characteristics of mutually coupled SQUIDs (Superconducting Quantum Interference Devices) have been analytically and numerically investigated. The mutually coupled SQUIDs investigated is composed of an rf-SQUID and a dc-SQUID. Here, the rf-SQUID is a flux quantum generator and the dc-SQUID is a flux detector. The linearization method substituting sin-1x by (π/2)x (1x1) is found valid when it is applied to the mutually coupled SQUIDs, because it is possible to obtain the superconducting regions analytically. By computer implementation of linearization method, we found this method is very effective and very quick compared to the ordinary methods. We report the internal flux on an rf-SQUID, the threshold of a dc-SQUID, and that of mutually coupled SQUIDs obtained by Lagrange multiplier formulation and linearization. The features of the threshold characteristics of the mutually coupled SQUIDs with various parameters are also reported. The discontinuous behavior of threshold of the mutually coupled SQUIDs are attractive for digital applications. We suggest three applications of the mutually coupled SQUIDs, that is, a logic gate for high-Tc superconductors (HTSs), a neuron device, and an A/D converter.
Alberto PALACIOS PAWLOVSKY Makoto HANAWA
This paper describes a new method for the concurrent detection of faults in instruction level parallel (ILP) processors. This method uses the No OPeration (NOP) instruction slots that under branches, resource conflicts and some kind of data dependencies fill some of the pipelines (stages) in an ILP processor. NOPs are replaced by the copy of an effective instruction running in another pipeline. This allows the checking of the pipelines running the original instruction and its copy (ies), by the comparison of the outputs of their stages during the execution of the replicated instruction. We show some figures obtained for the application of this method to a two-pipeline superscalar processor.
Kotaro MATSUSAKA Akira KUMAMOTO
This system called COKIS automatically extracts knowledge about C functions from the UNIX on-line manual by using its description paragraph and the user can interactively inquire to the system in order to know about UNIX C functions. The idea is motivated on the one side to free users from being involved in an exhaustive knowledge acquisition in the past, and to examine problems in understanding knowledge itself on the other. We propose Memory Processor which is implemented to realize extracting knowledges from corpus and processing dialogues in the inquiry system at the same modules.
Takehisa ISHIDA Osamu MORITA Makoto NODA Satoru SEKO Shoji TANAKA Hideaki ISHIOKA
Embossed disks with discrete magnetic tracks and servo marks are proposed and evaluated. The tracks and the servo marks are made by etching the glass substrate. The guard band depth was decided to be 0.2 µm. Using the disks, the head positioning accuracy of 0.09µm (rms) and the recording density of 192 tracks per millimeter were demonstrated.
In this paper, we show that without any unproven assumption, there exists a "four" move blackbox simulation perfect zero-knowledge interactive proof system of computational ability for any random self-reducible relation R whose domain is in BPP, and that without any unproven assumption, there exists a "four" move blackbox simulation perfect zero-knowledge interactive proof system of knowledge on the prime factorization. These results are optimal in the light of the round complexity, because it is shown that if a relation R has a three move blackbox simulation (perfect) zero-knowledge interactive proof system of computational ability (or of knowledge), then there exists a probabilistic polynomial time algorithm that on input x ∈ {0, 1}*, outputs y such that (x, y)∈R with overwhelming probability if x ∈dom R, and outputs "⊥" with probability 1 if x
Hiroaki YADA Takamichi YAMAKOSHI Noriyuki YAMAMOTO Murat ERKOCEVIC Nobuhiro HAYASHI
A novel external clocking magnetic disk recording channel is proposed and examined. Timing not only for data recovery but for recording is given by a bit clock which is synchronized with dedicated clock marks on patterned discrete track media. Jitter of the bit clock is 2.5 ns (rms), which is good enough for data rates up to about 20 Mbit/s. Using an MR/Inductive head and PRML (Partial Response Maximum Likelihood) signal processing, an error rate of 110-6 is obtained at linear density 3146 bit/mm.
Based on distributed artificial intelligence technology, the paper proposes a distributed expert system for distribution system planning. The developed expert system is made up of a set of problem-solving agents that autonomously process local tasks and cooperatively interoperate with each other by a shared database in order to reach a proper distribution plan. In addition, a two-level control mechanism composed of local-control and meta-control is also proposed to achieve a high degree of goodness in distribution system planning. To demonstrate its effect, the distributed expert system is implemented on basis of NASA's CLIPS and SUN's RPC and applied to the planning of distribution system in Taiwan. Test results indicate that the distributed expert system assists system planners in making an appropriate plan.
In this paper, we propose a fuzzy Petri net model for a rule-based decision making system which contains uncertain conditions and vague rules. Using the transformation method introduced in the paper, one can obtain the fuzzy Petri net of the rule-based system. Since the fuzzy Petri net can be represented by some matrices, the algebraic form of a state equation of the fuzzy Petri net is systematically derived. Both forward and backward reasoning are performed by using the state equations. Since the proposed reasoning methods require only simple arithmetic operations under a parallel rule firing scheme, it is possible to perform real-time decision making with applications to control systems and diagnostic systems. The methodology presented is also applicable to classical (nonfuzzy) knowledge base systems if the nonfuzzy system is considered as a special case of a fuzzy system with truth values being equal to the extreme values only. Finally, an illustrative example of a rule-based decision making system is given for automobile engine diagnosis.
The purpose of this paper is to offer a modal logic which enables us symbolic reasoning about data, especially, fuzzy relations. For such a purpose, the present author provided some systems of modal fuzzy logic. As a continuous one of those previous works, a logic based on the graded modalities is proposed. After showing some properties of this logic, the decision procedure for this logic is given in the rectangle method.
Atsushi IMIYA Kiyoshi WADA Toshihiro NAKAMURA
Mathematical morphology clarified geometrical properties of shape analysis algorithms for binary pictures. Results of labelling, distance transform, and adjacent numbering are, however, coded pictures. For full descriptions of shape analysis algorithms in the framework of mathematical morphology, it is necessary to extend morphological operations to code-labelled pictorial data. Nevertheless, extensions of morphology to code-labelled pictures have never discussed though the theory of gray morphology is well studied by several authors. Hence, this paper proposes a theory of the coded morphology which is based on the binary scaling of labels of pixels. The method uses n-layered binary sub-pictures for the processing of a picture with 2n labels. By introducing morphological operations for the coded point sets, we express some coding functions in the manner of the mathematical morphology. We also derive multidimensional array registers and gates which store and process coded pictures and morphological operations to them by proposing basic gates which compute parallelly logical operations for elements of Boolean layered arrays. These gates and registers are suitable for the implementation of the shape analysis processors on the three-dimensional VLSI and ULSI.
In this paper, we consider a class of the languages that have (constant round) perfect zero-knowledge interactive proofs without assuming any complexity assumptions. Especially, we investigate the interactive protocol with the restricted prover who runs in probabilistic polynomial time and knows the complete factorization as a trapdoor information of the integer associated with the input. We give a condition of the existence of constant round perfect zero-knowledge interactive proofs without assuming any complexity assumptions. The bit commitment based on the quadratic residuosity has an important role in our protocol and the simulation is based on the technique developed by Bellare, Micali, and Ostrovsky in Ref. (9), so call double running process. However, the proof of perfect zero-knowledgeness needs a more powerful simulation technique. Our simulation extracts more knowledge, the complete factorization of the integer associated with the input, from a (cheating) verifier than Bellare-Micali-Ostrovsky's simulation does. Furthermore, our main result implies that Blum integer has a five move perfect zero-knowledge interactive proof without assuming any complexity assumptions. (All previous known zero-knowledge protocols for Blum integer required either unproven cryptographic assumptions or unbounded number of rounds of message exchange.)
Hee-Jin LEE Takashi OMAE Shozo KOMAKI Norihiko MORINAGA
This paper analyzes the performance of the capacity controlled radio system under a frequency selective fading environment. This system controls the number of modulation levels according to the number of active subscribers. In the analysis, we consider the capacity controlled system either with or without adaptive equalizer. As the results of analysis, it is clarified that the system is superior to the conventional fixed capacity system, and can be considered as a good countermeasure for multi-path fading. And it is found that there exists a synergistic effect due to capacity controlling and adaptive equalizing.
Chang Hoon LEE Moon Hae KIM Jung Wan CHO
In general, the work on developing an expert system has relied on domain experts to provide all domain-specific knowledge. The method for acquiring knowledge directly from experts is inadequate in oriental medicine because it is hard to find an appropriate expert and the development cost becomes too high. Therefore, we have developed two effective methods for acquiring knowledge indirectly from sample cases. One is to refine a constructed knowledge base by using sample cases. The other is to train a neural network by using sample cases. To demonstrate the effectiveness of our methods, we have implemented two prototype systems; the Oriental Medicine Expert System (OMES) and the Oriental Medicine Neural Network (OMNN). These systems have been compared with the system with the knowledge base built directly by domain experts (OLDS). Among these systems, OMES are considered to be superior to other systems in terms of performances, development costs, and practicalness. In this paper, we present our methods, and describe our experimental and comparison results.