• 제목/요약/키워드: practical problem-based program

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개선된 유전자 알고리즘을 이용한 평면 철골트러스의 형상계획 및 단면 이산화 최적설계 (Shape Scheme and Size Discrete Optimum Design of Plane Steel Trusses Using Improved Genetic Algorithm)

  • 김수원;여백유;박춘욱;강문명
    • 한국공간구조학회논문집
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    • 제4권2호
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    • pp.89-97
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    • 2004
  • 최적설계기법을 사용한 경제적인 설계의 필요성은 오래 전부터 요구되어 왔으나, 종전의 설계가 설계자의 경험에 의한 시행착오적인 반복설계를 통하여 이루어져 왔기 때문에 구조물의 형상이 복잡한 경우에는 계산상의 어려움과 반복계산을 되풀이해야 하는 번거로움으로 진정한 최적설계는 기대하기 어려웠다. 최적설계법이 구조물의 설계에 매우 유용하다는 사실이 증명되고 있긴 하지만, 아직도 최적설계의 의미를 제대로 이해하지 못하고 있는 실정이며, 더구나 설계실무자는 어디까지나 사용자이기 때문에 수리적 계획수법에 친숙할 필요까지는 없지만 최소한 이런 기법의 가능성과 중요성을 이해할 필요는 있는데 대부분 그러하지 못하고 있는 실정이다. 일반적으로 트러스 구조물 설계 시 주어진 부재의 응력에 따라 단면적을 산출하여 그 단면적에 역학적으로 가장 합리적인 단면을 선정하여 경제적인 설계단면을 구한다. 그러나 트러스의 형상, 트러스 높이에 따른 경제성의 문제는 보통 설계자의 경험과 직관에 의하여 결정되고, 특별한 검토가 이루어지지 않고 설계가 수행되는데, 실제 트러스 구조물에서 트러스의 형상과 높이가 전체 건설공사비에 크게 영향을 미친다. 그러므로, 트러스 구조물의 최적설계에서 트러스 형상, 라이즈 비(rise ratio : 높이/스팬) 및 격간 수(number of panel)를 고려하는 것이 필요하다. 트러스 형상과 스팬에 따른 최적형상과 최적높이 및 격간 수에 대해 설계자의 초기 구조계획 시 주관적 선택의 어려움을 해결하고, 실제의 지붕형 트러스 구조에 설계하중을 작용시켜 응력해석에서부터 부재 단면설계까지의 자동화된 최적설계 알고리즘을 개발할 필요가 있다. 따라서 본 연구는 플랫 트러스의 형상, 격간 수, 격간의 간격 및 부재단면 등에 대하여 이산적인 변수의 처리와 넓은 설계 공간의 탐색능력과 더불어 문제의 비선형성과 관계없이 전체 최적해를 찾아낼 수 있는 유전자 알고리즘을 이용한다. 또한, 강 구조 한계상태설계기준(대한건축학회, 1998)을 기준으로 하여 자동으로 플랫 트러스의 구조계획과 단면이산화 최적설계를 동시에 수행할 수 있는 최적화 알고리즘을 제시하는 것을 목적으로 한다.

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비대칭 오류비용을 고려한 분류기준값 최적화와 SVM에 기반한 지능형 침입탐지모형 (An Intelligent Intrusion Detection Model Based on Support Vector Machines and the Classification Threshold Optimization for Considering the Asymmetric Error Cost)

  • 이현욱;안현철
    • 지능정보연구
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    • 제17권4호
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    • pp.157-173
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    • 2011
  • 최근 인터넷 사용의 증가에 따라 네트워크에 연결된 시스템에 대한 악의적인 해킹과 침입이 빈번하게 발생하고 있으며, 각종 시스템을 운영하는 정부기관, 관공서, 기업 등에서는 이러한 해킹 및 침입에 의해 치명적인 타격을 입을 수 있는 상황에 놓여 있다. 이에 따라 인가되지 않았거나 비정상적인 활동들을 탐지, 식별하여 적절하게 대응하는 침입탐지 시스템에 대한 관심과 수요가 높아지고 있으며, 침입탐지 시스템의 예측성능을 개선하려는 연구 또한 활발하게 이루어지고 있다. 본 연구 역시 침입탐지 시스템의 예측성능을 개선하기 위한 새로운 지능형 침입탐지모형을 제안한다. 본 연구의 제안모형은 비교적 높은 예측력을 나타내면서 동시에 일반화 능력이 우수한 것으로 알려진 Support Vector Machine(SVM)을 기반으로, 비대칭 오류비용을 고려한 분류기준값 최적화를 함께 반영하여 침입을 효과적으로 차단할 수 있도록 설계되었다. 제안모형의 우수성을 확인하기 위해, 기존 기법인 로지스틱 회귀분석, 의사결정나무, 인공신경망과의 결과를 비교하였으며 그 결과 제안하는 SVM 모형이 다른 기법에 비해 상대적으로 우수한 성과를 보임을 확인할 수 있었다.

방화범죄의 실태와 그 대책 - 관심도와 동기의 다양화에 대한 대응 - (The Reserch on Actual Condition of Crime of Arson Which Occurs in Korea and Its Countermeasures)

  • 최종태
    • 시큐리티연구
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    • 제1호
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    • pp.371-408
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    • 1997
  • This article is the reserch on actual condition of crime of arson which occurs in Korea and its countermeasures. The the presented problem in this article are that (1) we have generally very low rate concern about the crime of arson contrary to realistic problems of rapid increase of crime of arson (2) as such criminal motives became so diverse as to the economic or criminal purpose unlike characteristic and mental deficiency of old days, and to countermeasure these problems effectively it presentation the necessity of systemantic research. Based on analysis of reality of arson, the tendency of this arson in Korea in the ratio of increase is said to be higher than those in violence crime or general fire rate. and further its rate is far more greater than those of the U.S.A. and Japan. Arson is considered to be a method of using fire as crime and in case of presently residence to be the abject, it is a public offense crime which aqccompany fatality in human life. This is the well It now fact to all of us. And further in order to presentation to the crime of arson, strictness of criminal law (criminal law No, 164 and 169, and fire protection law No. 110 and 111) and classification of arsonist as felony are institutionary reinforced to punish with certainty of possibility, Therefore, as tendency of arson has been increased compared to other nations, it is necessary to supplement strategical policy to bring out overall concerns of the seriousness of risk and damage of arson, which have been resulted from the lack of understanding. In characteristics analysis of crime of arson, (1) It is now reveald that, in the past such crime rate appeared far more within the boundary of town or city areas in the past, presently increased rate of arsons in rural areas are far more than in the town or small city areas, thereby showing characteristics of crime of arson extending nation wide. (2) general timetable of arson shows that night more than day time rate, and reveald that is trait behavior in secrecy.(3) arsonists are usually arrested at site or by victim or report of third person(82,9%).Investigation activities or self surrenders rate only 11.2%. The time span of arrest is normally the same day of arson and at times it takes more than one year to arrest. This reveals its necessity to prepare for long period of time for arrest, (4) age rate of arson is in their thirties mostly as compared to homicide, robbery and adultery, and considerable numbers of arsons are in old age of over fifties. It reveals age rate is increased (5) Over half of the arsonists are below the junior high school (6) the rate of convicts by thier records is based on first offenders primarily and secondly more than 4 time convicts. This apparently shows necessity of effective correctional education policy for their social assimilation together with re-investigation of human education at the primary and secondary education system in thier life. The examples of motivation for arosnits, such as personal animosity, fury, monetary swindle, luscious purpose and other aims of destroying of proof, and other social resistance, violence including ways of threatening, beside the motives of individual defects, are diverse and arsonic suicide and specifically suicidal accompany together keenly manifested. When we take this fact with the criminal theory, it really reveals arsons of crime are increasing and its casualities are serious and a point as a way of suicide is the anomie theory of Durkheim and comensurate with the theory of that of Merton, Specifically in the arson of industrial complex, it is revealed that one with revolutionary motive or revolting motive would do the arsonic act. For the policy of prevention of arsons, professional research work in organizational cooperation for preventive activities is conducted in municipal or city wise functions in the name of Parson Taskforces and beside a variety of research institutes in federal government have been operating effectively to countermeasure in many fields of research. Franch and Sweden beside the U.S. set up a overall operation of fire prevention research funtions and have obtained very successful result. Japan also put their research likewise for countermeasure. In this research as a way of preventive fire policy, first, it is necessary to accomodate the legal preventitive activities for fire prevention in judicial side and as an administrative side, (1) precise statistic management of crime of arson (2) establishment of professional research functions or a corporate (3) improvement of system for cooperative structural team for investigation of fires and menpower organization of professional members. Secondly, social mentality in individual prospect, recognition of fires by arson and youth education of such effect, educational program for development and practical promotion. Thirdly, in view of environmental side, the ways of actual performance by programming with the establishment of cooperative advancement in local social function elements with administrative office, habitants, school facilities and newspapers measures (2) establishment of personal protection where weak menpowers are displayed in special fire prevention measures. These measures are presented for prevention of crime of arson. The control of crime and prevention shall be prepared as a means of self defence by the principle of self responsibility Specifically arsonists usually aims at the comparatively weak control of fire prevention is prevalent and it is therefore necessary to prepare individual facilities with their spontaneous management of fire prevention instead of public municipal funtures of local geverment. As Clifford L. Karchmer asserted instead of concerns about who would commit arson, what portion of area would be the target of the arson. It is effective to minister spontaveously the fire prevention measure in his facility with the consideration of characteristics of arson. On the other hand, it is necessary for the concerned personnel of local goverment and groups to distribute to the local society in timely manner for new information about the fire prevention, thus contribute to effective result of fire prevention result. In consideration of these factors, it is inevitable to never let coincide with the phemonemon of arsons in similar or mimic features as recognized that these could prevail just an epedemic as a strong imitational attitude. In processing of policy to encounter these problems, it is necessary to place priority of city policy to enhancement of overall concerns toward the definitive essense of crime of arson.

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