• 한국콘텐츠학회논문지
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• 제10권4호
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• pp.10-18
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• 2010

본 논문에서는 유전자알고리즘을 이용한 시그모이드 활성화 함수 파라미터의 최적화와 이중나선기준문제(two spirals benchmark problem)의 입력공간 패턴인식 상태를 분석 한다. 실험을 위하여 캐스케이드 코릴레이션 학습 알고리즘(Cascade Correlation learning algorithm)을 이용한다. 첫 번째 실험에서는 기본적인 시그모이드 활성화 함수를 사용하여 이중나선 문제를 분석하고, 두 번째 실험에서는 시그모이드 활성화 함수(sigmoidal activation function)의 파라미터 값이 서로 다른 함수를 사용하여 8개의 풀을 구성한다. 세 번째 실험에서는 시그모이드 함수의 변위를 결정하는 세 개의 파라미터 값을 유전자 알고리즘을 이용하여 얻고 이 파라미터 값들이 적용된 시그모이드 함수들은 후보뉴런의 활성화를 위해서 사용된다. 이러한 알고리즘의 성능평가를 위하여 각 학습단계 마다 입력패턴공간에서 인식된 이중나선의 형태를 보여준다.

• Journal of Multimedia Information System
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• 제3권3호
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• pp.91-96
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• 2016

Network security is an interesting area in Information Technology. It has an important role for the manager monitor and control operating of the network. There are many techniques to help us prevent anomaly or malicious activities such as firewall configuration etc. Intrusion Detection System (IDS) is one of effective method help us reduce the cost to build. The more attacks occur, the more necessary intrusion detection needs. IDS is a software or hardware systems, even though is a combination of them. Its major role is detecting malicious activity. In recently, there are many researchers proposed techniques or algorithms to build a tool in this field. In this paper, we improve the performance of IDS. We explore and analyze the impact of activation functions applying to recurrent neural network model. We use to KDD cup dataset for our experiment. By our experimental results, we verify that our new tool of IDS is really significant in this field.

• Nuclear Engineering and Technology
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• 제41권6호
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• pp.813-820
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• 2009

A rapid pneumatic transfer system (PTS) for an instrumental neutron activation analysis (INAA) is developed as an automatic irradiation facility involving the measurement of a short half-life nuclide and a delayed neutron counting system. Three new PTS designs with improved functions were constructed at the HANARO research reactor in 2006. The new system is composed of a manual system and an automatic system for both an INAA and a delayed neutron activation analysis (DNAA). The design and basic conception of a modified PTS are described, and the functions of system operation and control, radiation protection and emissions of radioactive gas are improved. In addition, a form of capsule transportation of these systems is tested. The experimental results pertaining to the irradiation characteristics with variation of the neutron flux and the temperature of the irradiation position with the irradiation time are presented, as is an analysis of the reference material for analytical quality control and uncertainty assessments.

• Bulletin of the Korean Chemical Society
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• 제18권3호
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• pp.280-286
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• 1997

Potential energy function sets for some ion-exchanged A-type zeolites, K-A and Rb11Na1-A, were determined by introducing the X-ray crystal structures as constraints. The potential functions reproduced well the X-ray crystal structures of the monovalent ion-exchanged zeolites. The activation energies for the en- or de-capsulation of small molecules (H2, O2, N2, and CH4) and inert gases from the α-cage of model zeolites (Na-A, K-A, Rb11Na1-A, and Cs3Na9-A) were obtained by the molecular mechanical calculations. The calculated activation energies agreed well with experimental results.

• 지능정보연구
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• 제10권2호
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• pp.53-63
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• 2004

순환 케스케이드 코릴레이션(Recurrent Cascade Correlation(RCC))은 감독에 의하여 학습하는 알고리즘이고 네트워크의 크기와 형태는 자동으로 이루어진다. RCC는 새로운 은닉뉴런들이 한 충에 하나씩 순서대로 네트워크에 삽입되기 때문에 다층구조를 형성하고 2계(Second Order) RCC는 새로운 은닉뉴런들이 한 층에만 순서대로 생성되어 나열되므로 2층 구조를 형성한다. 따라서 이러한 은닉뉴런들끼리는 서로 연결하지 않는다. 이 논문에서는 RCC와 2계 RCC의 조합을 통한 RCC 네트워크의 일반화를 소개한다. 새로운 RCC 알고리즘은 은닉뉴런이 네트워크에 첨가될 때마다 네트워크가 수직성장 또는 수평성장을 해야 하는지를 스스로 결정한다. 또한 뉴런의 활성화를 위한 새로운 활성화함수를 소개하고 기존의 sigmoid, tanh 함수와 함께 사용하여 모스 벤치마크 문제에 관하여 실험하였다. 이러한 활성화 함수들을 사용한 RCC 네트워크의 일반화 실험에서 은닉뉴런의 숫자가 감소하였음을 알 수 있다.

• Journal of Radiation Protection and Research
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• 제36권1호
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• pp.44-51
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• 2011

원자력발전소, 의료용 가속기 등 고선량 지역 및 능동형 열중성자 검출기를 사용하기 힘든 환경에서는 방사화 포일 기반 보너구 스펙트로메터를 사용하여 중성자 에너지 스펙트럼 측정을 수행한다. 중성자 방사화 포일을 보너구의 열중성자 검출기로 사용하는 경우, 중성자 방사화 포일의 위치 변동에 따른 보너구 반응도의 변화 및 중성자 방사화 포일의 질량과 반응도 사이의 상관관계 등 특성연구가 선행되어야만 한다. 본 연구에서는 MCNPX 모사계산을 통하여 중성자 방사화 포일 면에 수직입사하는 경우 중성자 방사화 포일의 위치 의존성이 크다는 사실과 중성자 방사화 포일의 질량과 반응도 사이에 선형관계가 없음을 알 수 있었다. 본 연구를 통하여 중성자 방사화 포일 기반 보너구의 반응함수 계산 방법 및 중성자 방사화 포일 위치 및 질량 차이에 따른 반응도 변화를 연구함으로써 중성자 방사화 포일 기반 보너구의 반응함수 결정방법을 확립하였다. 본 연구결과를 바탕으로 보너구 반응함수를 계산하여 추후 중성자 방사화 포일 기반 보너구 스펙트로메트리에 적용할 예정이다.

• IMMUNE NETWORK
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• 제12권6호
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• pp.240-246
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• 2012

Natural killer (NK) cells play a pivotal role in early surveillance against virus infection and cellular transformation, and are also implicated in the control of inflammatory response through their effector functions of direct lysis of target cells and cytokine secretion. NK cell activation toward target cell is determined by the net balance of signals transmitted from diverse activating and inhibitory receptors. A distinct feature of NK cell activation is that stimulation of resting NK cells with single activating receptor on its own cannot mount natural cytotoxicity. Instead, specific pairs of co-activation receptors are required to unleash NK cell activation via synergy- dependent mechanism. Because each co-activation receptor uses distinct signaling modules, NK cell synergy relies on the integration of such disparate signals. This explains why the study of the mechanism underlying NK cell synergy is important and necessary. Recent studies revealed that NK cell synergy depends on the integration of complementary signals converged at a critical checkpoint element but not on simple amplification of the individual signaling to overcome intrinsic activation threshold. This review focuses on the signaling events during NK cells activation and recent advances in the study of NK cell synergy.

• Archives of Pharmacal Research
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• 제22권5호
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• pp.454-458
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• 1999

TR8 is a recently identified member of the tumor necrosis factor (TNF) receptor superfamily. TR8 seems to play important roles in bone metabolism as stimulation of this receptor with its ligand, TL8 or osteoclast differentiation factor (ODF), induced the differentiation and activation of osteoclasts. Despite its important biological functions, the biochemcial events ensuing form TR8 activation have not been revealed in detail. Most of TNF receptor family proteins provoke the activation of the NF-$textsc{k}$B transcription factor. In the present study, we examined the signaling potential of TR8 to induce NF-B activation. When overexpressed in a human embryonic kidney cell line by transient transfection, TR8 caused a strong activation of NF-$textsc{k}$B, which was further increased upon stimulation with TL8. The TR8-induced NF-B activation was abrogated by the co-expression of the TRAF6 mutnat lacking the Ring and zinc finger domains and that of the kinase-inactive mutant NIK. Taken together, our study suggests that the presence of intact TRAF6 and the kiase activity of NIK may be essential for TR8 to induce NF-$textsc{k}$B activation.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1503-1508
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• 2009

The paradigm of urban generation does not lie in physical development/maintenance such as urban redevelopment any more. The paradigm is shifting to balanced activation of administration / management functions including central commerce/business functions, broad culture/tourism functions, international functions and adequate level of residence functions. The urban regeneration project aims to restore functions of cities by physical/environmental, living/cultural and industrial/economical regeneration and is managed differently from existing projects in that it includes multiple sub-projects in it. The overall projects management should be by managing the value sought by the urban regeneration project and multiple other sub-projects. The objective of this study is to present various methods of value management in order to avoid conflicts between various objectives within the said project. It aims to provide the value management methods for decision making by understanding correlatedness between values of various projects and prioritizing them.

• 약학회지
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• 제52권1호
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• pp.48-55
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• 2008

CD29 $({\beta}1-integrins)$ is one of major adhesion molecules involved in regulating cell adhesion, migration and morphological changes. In this study, we investigated the regulatory role of CD29 in monocytic functions using monocytic cell line U937 cells. CD29 was found to be one of highly expressed membrane proteins in U937 cells, according to flow cytometric analysis. The activation of CD29 by agonistic antibody MEM101A and extracellular matrix protein (ECM) fibronectin strongly induced cell-cell and cell-fibronectin adhesions. However, blocking antibodies to CD98 and CD147 showed different inhibitory features in these two adhesion events. Furthermore, U0126, an ERK inhibitor, only blocked cell-cell adhesion but not cell-fibronectin adhesion, indicating that cell-cell or cell-fibronectin adhesion events may be regulated by different molecular mechanisms. Meanwhile, CD29 activation also enhanced ROS generation but not phagocytic ability, and similarly radical scavenger N-acetyl-L-cysteine strongly blocked CD29-mediated cell-cell adhesion, implying that ROS may play a critical role in up-regulating cell-cell adhesion. Therefore, our data suggest that the activation of CD29 may be critically involved in regulating monocytic cell-mediated cell-cell adhesion and ROS generation.