• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.415-418
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• 2002

상태 불변식은 도달 가능한 모든 상태에서 항상 만족되는 식이다. 이는 복잡한 시스템의 이해와 분석에 활용될 뿐만 아니라 시스템의 안전성, 일관성, 완전성 검사에 사용된다. 이와 같은 이유로, 상태 불변식의 추론은 폭 넓게 연구되었다. 기존의 연구에서는 시스템의 가능한 모든 상태를 고려하여 상태 불변식을 생성했다. 이러한 방법으로 생성된 상태 불변식은 매우 복잡하며 사용자가 이를 이해하고 활용하기가 어렵다. 본 연구에서는 두 가지 투영 방법을 통해 단순화된 상태 불변식을 생성한다. 첫째, 지정 범위를 통한 투영으로 고려해야 할 상태들을 줄인다. 둘째, 해당 범위에서 사용된 명제들로 상태 불변식을 투영하여 최소 부정 불변식을 찾고 이를 제거한다. 그 결과 사용자의 관심을 특정 범위와 명제에 집중시킬 수 있었으며 단순화된 상태 불변식을 통해 사용자의 이해와 활용도를 높일 수 있었다.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.207-211
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• 2012

Using Carnahan-Starling equation for hard spheres and a lattice model with an attractive potential, a new twoparameter equation of state for pure gases is derived. Using this equation, compressibility factors are calculated and compared with Nelson-Obert generalized compressibility factor charts. The results show that the agreement of this equation with the experimental Nelson-Obert charts is similar to that of Redlich-Kwong equation in the average. But parameters and terms of the new equation have physical meanings which are more definite than those of Redlich-Kwong equation.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.212-218
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• 2003

State invariant is a property that holds in every reachable state. It can be used not only in understanding and analyzing complex software systems, but it can also be used for system verifications such as checking safety, liveness, and consistency. For these reasons, there are many vital researches for deriving state invariant from finite state machine models. In previous works every reachable state is to be considered to generate state invariant. Thus it is likely to be too complex for the user to understand. This paper seeks to answer the question `how to simplify state invariant\ulcorner`. Since the complexity of state invariant is strongly dependent upon the size of states to be considered, so the smaller the set of states to be considered is, the shorter the length of state invariant is. For doing so, we let the user focus on some interested scopes rather than a whole state space in a model. Computation Tree Logic(CTL) is used to specify scopes in which he/she is interested. Given a scope in CTL, mixed reachability analysis is used to find out a set of states inside it. Obviously, a set of states calculated in this way is a subset of every reachable state. Therefore, we give a weaker, but comprehensible, state invariant.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.3
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• pp.395-404
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• 2013

A pattern matching algorithm plays an important role in traffic identification and classification based on predefined patterns for intrusion detection and prevention. As attacks become prevalent and complex, current patterns are written using regular expressions, called regexes, which are expressed into the deterministic finite automata(DFA) due to the guaranteed worst-case performance in pattern matching process. Currently, because of the increased complexity of regex patterns and their large number, memory-efficient DFA from states reduction have become the mainstay of pattern matching process. However, most of the previous works have focused on reducing only the number of states on a single automaton, and thus there still exists a state blowup problem under the large number of patterns. To solve the above problem, we propose a new state compression algorithm that merges states on multiple automata. We show that by merging states with the same input character on multiple automata, the proposed algorithm can lead to a significant reduction of the number of states in the original DFA by as much as 40.0% on average.

• Journal of the Korean Society of Food Culture
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• v.10 no.5
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• pp.435-442
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• 1995

This study is to investigate the eating habits of 420 businessmen living in urban areas (Taegu, Gumi, Youngchon and Changwon) in Kyungbuk and Kyungnam provinces. This survey was carried out by questionnaires. The results are summarized as the following in the association of demographic variables and eating habits, occupation (p<0.001), age (p<0.01), spouse's occupation, dwelling state, and monthly income (p<0.05) had statistically significant relationships. Middle aged adults placed more attention on eating habits than young adults. High-class professionals, managers and salesmen had a high frequency of 'good' eating habits, while office-workers had a high frequency of 'bad' eating habits. In the association of eating behavior, health status variables and eating habits, the frequency of meals, exercise, sleep, degree of fatigue, life styles, digestibility, and health status (p<0.001) had significant relationships. It seems that eating behavior and health conditions have direct effects on eating habits.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.3
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• pp.183-189
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• 2013

In this paper, uncertainties and failure criteria of structure are mathematically expressed by random variables and a limit state equation. A limit state equation is approximated by Fleishman's 3rd order polynomials and the theoretical moments of an approximated limit state equation are calculated. Fleishman introduced a 3rd order polynomial in terms of only standard normal distiribution random variables. But, in this paper, Fleishman's polynomial is extended to various random variables including beta, gamma, uniform distributions. Cumulants and a normalized limit state equation are used to calculate a theoretical moments of a limit state equation. A cumulative distribution function of a normalized limit state equation is approximated by a Pearson system.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.7
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• pp.356-371
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• 2001

본 논문에서는 비동기식 상위수준합성기 제작의 일환으로 효율적인 비동기식 제어부의 자동생성에 관한 방법을 제안한다. 제안된 방법은 목적시스템의 사양으로써 주어진 제어데이터흐름그래프로부터 일련의 체계적인 변환과정을 통하여, 제어부를 구성할 제어회로들에 대응하는 계층적으로 분할된 비동기식 유한상태기들의 집합을 유도한다. 유도된 비동기식 유한상태기들은 현존하는 비동기식 제어회로 합성기를 통하여 해저드 없는 비동기식 제어회로들로 합성되며, 이들은 상호간에 4단계 핸드셰이킹에 기반한 신호교환을 통하여 동작하면서 전체 시스템을 제어하는 계층적으로 분할된 비동기식 제어부를 구성한다. 획득한 제어부는 계층.분산적이며, 면적, 성능 및 합성시간의 측면에서 기존방식을 통하여 생성한 제어부에 비해 우월하다.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.140-142
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• 2008

본 논문에서는 새로운 공유결합 인덕터를 이용한 비대칭 입력전압형 하프브릿지 컨버터를 제안하고 그 정상상태 해석결과를 보고한 것이다. 제안된 컨버터는 반도체 스위치와 주요 소자를 이상적으로 가정하여 내부손실을 무시한 등가회로를 유도하였고 등가회로로부터 스위치의 상태에 따른 상태별 등가회로로부터 주요 소자에 대한 특성식을 나타내었고 최종적으로는 컨버터의 정상상태 특성식을 유도하였으며 특성식의 타당성을 확인하기 위해서 시험회로를 구성하였고 그 결과 제안 회로방식의 정상상태 해석결과를 검증할 수 있었다.

• Journal of Digital Convergence
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• v.13 no.6
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• pp.287-296
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• 2015

This study was purposed to figure out current situation of part of 273 middle-school girls' dietary behavior and problems, then provide baseline data which helps to develop desirable eating behavior and life style. It appeared that suitable amount of eating(F=6.378, p=.002), degree of unbalanced diet(F=3.542, p=.030), Nutrients intake(F=6.780, p=.001), and life style(F=4.291, p=.015) differs between groups depending on student's subjective physical health status. It turned up that perceived physical health status is related to moderate amount of eating, degree of unbalanced diet, and Nutrients intake(p<0.05). As a results, in the period of adolescent which is a rapid growth period, there should be a systematic and endurable practice of right eating behavior, foods for formation of lifestyle, and convergence education in health area.

• KOREAN POULTRY JOURNAL
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• v.34 no.11 s.397
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• pp.101-106
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• 2002

1980년대 산란 농가의 케이지는 대부분 A형이 주를 이루었으며, 1990년대에는 정부의 시설자금 지원이 본격화되면서 자동화$\cdot$대형화의 조류를 타고 외국산 직립식 케이지가 국내에 보급되기 시작하였다. 초기 직립식 케이지 설치로 평당 사육수수 증가가 가능했지만 자동화에 대한 지식 부족으로 질병과 생산성이 떨어지는 역효과도 있었다. 10년 이상 직립식 케이지에 적응하다 보니 노하우가 축적되어 대형 농장 위주로 직립식 케이지 설치가 증가하였고, 관리면에서도 안정을 보여주고 있다. 그러나 IMF이후 외국산 케이지를 설치하는 농가도 줄어들었고, 설상가상으로 정부의 시설자금 지원도 중단된 상태여서 외국산 케이지 보급이 소강상태를 보이다 최근에 와서 다시 설치가 증가하고 있다. 이와 관련하여 국내에 보급된 케이지 관리실태와 A/S현황을 알아보았다.