• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10c
• /
• pp.72-74
• /
• 1998

정보검색 시스템에서 시소러스는 정보항목에 대한 용어들간의 관계를 계층적 구조로 나타낸다. 따라서 정보검색 시스템에서 시소러스의 사용은 이용자의 질의에 있는 탐색어와 관련된 정보항목들을 검색할 수 있기 때문에 정보검색 시스템의 검색효율을 크게 증가시킬 수 있다. 그러나 기존의 시소러스 모델들은 용어들간의 관련 정도를 무시하거나 정량적인 수치값으로 부여하기 때문에 인간의 주관성과 부정확성을 다루는데 적합하지 않다. 용어들간 의미의 밀접한 정도(Degree of Closeness)는 모호하고 부정확한 판단에 근거하는 인간의 정성적인 측정 단위이다. 그러므로 관련정도를 정량적으로 표현하는 것은 정성적 개념을 정확한 숫자 값으로 변환하는 것이기 때문에 인간의 정성적 측정 단위를 정확하고 용이하게 정량적으로 측도하여 반영한다는 것은 어렵다. 따라서 본 논문에서는 용어들간의 관련도를 정성적으로 부여한 시소러스 모델을 제안한다. 이 시소러스 모델에서는 색인어간의 관련도를 정성적으로 표현하기 위해 퍼지 집합 이론에 근거한 언어적 설명자들을 정의한다. 언어적 설명자들은 존재론적 문제가 고려되고 다분히 인식론적인 표현에 근거한다.

• Korean Journal of English Language and Linguistics
• /
• v.2 no.1
• /
• pp.123-147
• /
• 2002

As far as the recent ELT research concerned, it seems to have been no hot ‘theoretical’ issues, but ‘practical’ ones in general: e.g., learners and learning, components of proficiency, correlates of L2 learning, etc. This paper focuses on the theme given above, with a special reference to the sub-title: specifically, 1) World English, world Englishes and world's lingua franca; 2) ENL, ESL and EFL; 3) Grammars, style manuals, dictionaries and media; 4) Pronunciation models: RP, BBC model and General American, Network Standard; 5) Lexical, grammatical variations and discourse grammars; 6) Beliefs and subjective theories in foreign language research; 7) Dilemma among radical, canonical and eclectic views. In conclusion, the author offers a modest proposal: we need to appeal to our own experience, intention, feeling and purpose, that is, our identity to express “our own selves” in our contexts toward the world anywhere, if not sounding authentic enough, but producing it plausibly well. It is time for us (with our ethno-cultural autonomy) to need to be complementary to and parallel with its native speakers' linguistic-cultural authenticity in terms of the broadest mutual understanding.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.13 no.21
• /
• pp.29-41
• /
• 1990

An assessment of risk in industrial and urban environments is essential in the prevention of accident and in the analysis of situations which are hazardous to public health and safety. The risk imposed by a particular hazard increases with the likelihood of occurence of the event, the exposure and the possible consequence of that event. In a traditional approach, the calculation of a quantitative value of risk is usually based on an assignment of numerical values of each of the risk factors. Then the product of the values of likelihood, exposure and consequences called risk score is derived. However vagueness and imprecision in mathematical quantification of risk are equated with fuzziness rather than randomness. In this paper, a fuzzy set theoretic approach to risk analysis is proposed as an alternative to the techniques currently used in the area of systems safety. Then the concept of risk evaluation using linguistic representation of the likelihood, exposure and consequences is introduced. A risk assessment model using approximate reasoning technique based on fuzzy logic is presented to drive fuzzy values of risk and numerical example for risk analysis is also presented to illustrate the results.

• Speech Sciences
• /
• v.8 no.4
• /
• pp.157-168
• /
• 2001

The limited capacity model has been used to explain linguistic interactions and trade-offs that occur in children's speech. The purpose of the present investigation is to explore the interrelationship of MLU (as an index of syntactic development) and fluency in the spontaneous speech of normal children. Twenty normal children's (ten girls and ten boys, aged 36-48 months) spontaneous speech samples were obtained during free-play interactions with their mothers or other adults. The results indicated that the MLU of disfluent utterances were significantly longer than that of fluent utterances. Also, disfluencies occurred more frequently in longer utterances than in shorter utterances. In addition, the utterances where disfluencies occurred more than 2 times were longer than those where disfluencies occurred once. These results imply that the increase of MLU appear to affect not only the occurrence of disfluent utterances, but also the number of disfluencies within the utterances. In other' words, these findings show that there are trade-off effects between MLU and fluency. This is discussed within a limited capacity framework.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.992-994
• /
• 1995

FLC has a good performance for complication system or unknown model by using human linguistic method but many part control design are based on expert knowledge or trial-error method and it is difficult to prove stability and robustness of controller. In this paper we improve this problem by setting fuzzy rules by dividing phase plane of error and rate of error change by switching surface. We can guarantee the stability in nonlinear system, and also in fuzzy PID type controller the complexity of controller design is increased by increasing the number of input variables and defining more range of operation if we want performance of more specific rules, thus we need to fine the method to decrease the number of control rules used in FLC design. In this paper the algorithm is validated by simulation using conventional FLC and proposed method.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.54 no.2
• /
• pp.67-72
• /
• 2005

This paper presents a method to select contingency ranking considering voltage security problems in power systems. Direct method which needs not the detailed knowledge of the post contingency voltage at each bus is used. Based on system operator's experience and knowledge, the membership functions for the MVAR mismatch and allowable voltage violation are justified describing linguistic representation with heuristic rules. Rule base is used for the computation of severity index for each contingency by fuzzy inference. Contingency ranking harmful to the system is formed by the index for security evaluation. Compared with 1P-1Q iteration, this algorithm using direct method and fuzzy inference shows higher computation speed and almost the same accuracy. The proposed method is applied to model system and KEPCO pratical system which consists of 311 buses and 609 lines to show its effectiveness.

• Genomics & Informatics
• /
• v.9 no.1
• /
• pp.5-11
• /
• 2011

Treating genomes just as languages raises the possibility of producing concise generalizations about information in biological sequences. Grammars used in this way would constitute a model of underlying biological processes or structures, and that grammars may, in fact, serve as an appropriate tool for theory formation. The increasing number of biological sequences that have been yielded further highlights a growing need for developing grammatical systems in bioinformatics. The intent of this review is therefore to list some bibliographic references regarding the recent progresses in the field of grammatical modeling of biological sequences. This review will also contain some sections to briefly introduce basic knowledge about formal language theory, such as the Chomsky hierarchy, for non-experts in computational linguistics, and to provide some helpful pointers to start a deeper investigation into this field.

• Nuclear Engineering and Technology
• /
• v.25 no.3
• /
• pp.371-380
• /
• 1993

A model free controller utilizing a set of linguistic fuzzy logic of the human operator's experience is developed to control the steam generator water level in a pressurized water reactor. Only 9 rules for control action are generated from the inputs of water level error and mass flow error implicitly representing the time variation of the collapsed water level. The bell type membership functions of the premise side and the result side are tuned by the sensitivity study. This compact fuzzy logic controller shows a robust control during transient and no offset error and oscillation during steady state operation. For a multi-ramp power increase from start-up to full power, the proposed controller shows good performance for the entire range.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.5 no.1
• /
• pp.25-32
• /
• 1995

In this paper, the FLVSC (Fuzzy Logic Variable Structure controller), of which control rules are extracted from the concepts of the VSC(Variable Structure control) is proposed and diesgned for drum motor(BLDC motor) in home VCR. The FLC (Fuzzy Logic Controller) based on linguistic rules has the advantages of not needing of some exact mathermatical model for plant to be controlled. The proposed method has the characteristics which are viewed in conventional VSC, e.g. insensitivity to a class of distrubances, parameter variations and uncertainites in a sliding mode. In addition, the method has the properties of the FLC-noise rejection capability etc. The computer simulation and experiment using DSP(TMS320C30) have been carried out for the servo control of VCR drum motor to show the usefulness of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.43 no.5
• /
• pp.809-818
• /
• 1994

In this paper , the author proposed FLVSC (Fuzzy Logic Variable Structure Controller),of which control rules are extracted from the concepts of VSC(Variable Structure Control). FLC(Fuzzy Logic Controller) based on linguistic rules has the advantages of not needing of some exact mathematical model for plant to be controlled. The proposed method has the characteristics which are viewed in conventional VSC, e.g. insensitivity to a class of disturbances, parameter variations and uncertainties in sliding mode. In addition, the method has the properties of FLC-noise rejection capability etc. The computer simulations have been carried out for position control of DC servo motor to show the usefulness of the proposed method and the effects of disturbances and parameter variations are considered.