• Title/Summary/Keyword: structural complexity

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PfSGA를 이용한 MLP 분류기의 구조 학습 (A Structural Learning of MLP Classifiers Using PfSGA)

  • 愼晟孝;金 商雲
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.1277-1280
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    • 1998
  • We propose a structural learning method of MLP classifiers for a given application using PfSGA (parameter-free species genetic algorithm), which is a combining of species genetic algorithm(SGA) and parameter-free genetic algorithm(PfGA). experimental results show that PfSGA can reduce the learing time of SGA and has no influence of parameter values on structural learning. And we also convince that PfSGA is more efficient than the other methods in the aspect of misclassification ratio, learning rate, and complexity of MLP structure.

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Frequency Window Method에 의한 1차-2차 구조시스템의 진동특성 (Frequency Window Method for the Vibration of Primary-Secondary Structural Systems)

  • 민경원
    • 소음진동
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    • 제1권1호
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    • pp.45-52
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    • 1991
  • The dynamic properties of primary-secondary structural systems are examined using analytical expressions for the modal properties. The analysis begins with a Lagrange multiplier formulation to develop a characteristic equation in terms of primary system mobilities and secondary system impedances. The complexity of the characteristic equation by developing new method, frequency window method. It is shown that the reduction of complexity can only be obtained by a reduction of accuracy, but by retaining the dominant effects of the dynamics problem, the loss of accuracy is not excessive. The reduced problem is examined further to develop simple expressions for the modal properties which provide insight into the resonance characteristics of the primary-secondary system problem. The results are useful as a complement to existing computational techniques for understanding and interpreting dynamic analysis results.

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Heterogeneous Habitat for Increasing Biological Diversity

  • Lee, Sang-Don
    • 환경생물
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    • 제21권4호
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    • pp.337-341
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    • 2003
  • Habitat heterogeneity can enhance biological diversity by providing variation in structural diversity. This paper reviewed heterogeneous habitat serves as a population stability and superior demographic performance (e.g., high density, survivorship, reproductive rate) can be observed compared with organisms with inferior demographic performance. The idea of habitat variation has been further developed in modelling. Furthermore the size and configuration (distribution) of a patch (of a particular habitat type) become effective for the stability of population through hiding places and food resources. Species diversity is related to habitat complexity that provides structural diversity to ground -dwelling organisms. Finally coarse woody debris can enhance habitat complexity thus stabilizing population fluctuation and increasing survivorship.

A Study on the Ultimate Strength Behaviour of Stiffened Plate according to the Stiffener Section

  • Ko Jae-Yogn;Park Joo-Shin;Park Sung-Hyeon
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2004년도 춘계학술발표회
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    • pp.113-119
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    • 2004
  • A steel plated is typically composed of plate panels. The overall failure of the structure is certainly affected and can be governed by the bulking and plastic collapse of these individual members In the ultimate limit state design. therefore. a primary task is to accurately calculate the budding and plastic collapse strength of such structural members. Structural elements making up steel palated structures do not work separately. resulting in high degree of redundancy and complexity in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy need and degree of complexity of the analysis to be used Generally the more complex the analysis the greater is the accuracy that may be obtained. The aim of this study is the investigation of the effect of the tripping behaviour including section characteristic for a plate under uniaxial compression.

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대용량 소스코드 시각화기법 연구 (Visualization Techniques for Massive Source Code)

  • 서동수
    • 컴퓨터교육학회논문지
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    • 제18권4호
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    • pp.63-70
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    • 2015
  • 프로그램 소스코드는 텍스트를 기반으로 하는 정보이며 동시에 논리 구조를 포함하고 있는 복잡한 구문의 집합체이다. 특히 소스코드의 규모가 수만 라인에 이르는 경우 구조적, 논리적인 복잡함으로 인해 기존의 빅데이터 시각화 기법이 잘 적용되기 힘들다는 문제가 발생한다. 본 논문은 소스코드가 갖는 구조적인 특징을 시각화하는데 있어 필요한 절차를 제안한다. 이를 위해 본 논문은 파싱 과정을 거쳐 생성된 추상구문트리를 대상으로 프로그램의 구조특징을 표현하기 위한 자료형의 정의, 함수간 호출관계를 표현한다. 이들 정보를 바탕으로 제어 정보를 네트워크 형태로 시각화함으로써 모듈의 구조적인 특징을 개괄적으로 살펴볼 수 있는 방법을 제시한다. 본 연구의 결과는 대규모 소프트웨어의 구조적 특징을 이해하거나 변경을 관리하는 효과적인 수단으로 활용할 수 있다.

Estimation of geometry-based manufacturing cost of complex offshore structures in early design stage

  • Nam, Jong-Ho;Sohn, Se-Hwan;Singer, David J.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제4권3호
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    • pp.291-301
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    • 2012
  • A scalar metric for the assessment of hull surface producibility was known to be useful in estimating the complexity of a hull form of ships or large offshore structures by looking at their shape. However, it could not serve as a comprehensive measuring tool due to its lack of important components of the hull form such as longitudinals, stiffeners, and web frames attached to the hull surface. To have a complete metric for cost estimation, these structural members must be included. In this paper, major inner structural members are considered by measuring the complexity of their geometric shape. The final scalar metric thus consists of the classes containing inner members with various curvature magnitudes as well as the classes containing curved plates with single and double curvature distribution. Those two distinct metrics are merged into a complete scalar metric that accounts for the total cost estimation of complex structural bodies.

Structural reliability analysis using temporal deep learning-based model and importance sampling

  • Nguyen, Truong-Thang;Dang, Viet-Hung
    • Structural Engineering and Mechanics
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    • 제84권3호
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    • pp.323-335
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    • 2022
  • The main idea of the framework is to seamlessly combine a reasonably accurate and fast surrogate model with the importance sampling strategy. Developing a surrogate model for predicting structures' dynamic responses is challenging because it involves high-dimensional inputs and outputs. For this purpose, a novel surrogate model based on cutting-edge deep learning architectures specialized for capturing temporal relationships within time-series data, namely Long-Short term memory layer and Transformer layer, is designed. After being properly trained, the surrogate model could be utilized in place of the finite element method to evaluate structures' responses without requiring any specialized software. On the other hand, the importance sampling is adopted to reduce the number of calculations required when computing the failure probability by drawing more relevant samples near critical areas. Thanks to the portability of the trained surrogate model, one can integrate the latter with the Importance sampling in a straightforward fashion, forming an efficient framework called TTIS, which represents double advantages: less number of calculations is needed, and the computational time of each calculation is significantly reduced. The proposed approach's applicability and efficiency are demonstrated through three examples with increasing complexity, involving a 1D beam, a 2D frame, and a 3D building structure. The results show that compared to the conventional Monte Carlo simulation, the proposed method can provide highly similar reliability results with a reduction of up to four orders of magnitudes in time complexity.

웹 어플리케이션의 순환복잡도 메트릭스에 관한 연구 (A Study of Cyclomatic Complexity for Web Application)

  • 안종근;유해영
    • 정보처리학회논문지D
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    • 제9D권3호
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    • pp.447-456
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    • 2002
  • 웹 어플리케이션은 기존의 어플리케이션과는 다른 구조적인 특징을 가지고 있다. 웹 서버 상에서 실행되는 프로그램 코드인 서버측 스크립트 요소, 웹 브라우저에서 수행되는 프로그램 코드인 클라이언트측 스크립트 요소, 웹 브라우저에서 사용자가 선택하는 링크 요소 그리고 사용자의 선택을 클라이언트 스크립트로 연결시켜 주는 이벤트 요소, 이렇게 네 가지 요소들이 상호 연관되어 웹 어플리케이션을 구성한다. 기존의 어플리케이션들보다 다양한 요소들로 구성된 웹 어플리케이션에서 복잡도 측정에 기존의 모듈 또는 클래스 단위로 적용되는 복잡도 측정 방법을 그대로 적용하기 힘들다. 이에 본 논문에서는 웹 어플리케이션의 구조적인 복잡함을 반영하는 웹 어플리케이션의 순환복잡도(CCWA : Cyclomatic Complexity for Web Application) 메트릭스를 제안한다. 제안된 CCWA 도구를 개발하여, 현재 기업에서 사용중인 웹 어플리케이션에 적용하여 평가하였다. 그 결과 제안된 CCWA 도구는 각 요소들에 순환복잡도를 각각 적용했을 때에는 발견할 수 없었던 복잡도가 높은 웹 어플리케이션 파일을 발견하게 해주었다.

아동기 대인관계 외상, 정신 증상의 복잡성 및 해리의 매개 효과 (The Association Between Childhood Interpersonal Trauma and Psychiatric Symptom Complexity, and the Mediating Impact of Dissociation)

  • 김예슬;김석현;김대호;김은경;김지영;최나연
    • 대한불안의학회지
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    • 제18권2호
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    • pp.72-79
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    • 2022
  • Objective : Any traumatic event can be a risk factor, for subsequent mental disorder. However, childhood trauma, especially in interpersonal nature, is associated with later development of complex symptom patterns. This study examined the role of dissociation as a mediator between childhood trauma and symptom complexity. Methods : A pooled data of 369 psychiatric outpatients at a university-affiliated hospital was analyzed for descriptive statistics, group differences, and bivariate correlation analysis to verify a structural model. The questionnaires included the Symptom Checklist-90-Revised, the Trauma History Screen, the Dissociative Experiences Scale-Taxon, the Beck Depression Inventory, the Beck Anxiety Inventory, and the Abbreviated PTSD checklist. Results : When other trauma variables were controlled, childhood interpersonal trauma had significant correlation with symptom complexity (r=0.155, p=0.003). Among the paths analyzed, that of childhood interpersonal trauma and dissociation showed the greatest impact on symptom complexity (b=9.34, t=5.75, p<0.001). Based on the significance of the indirect impact, the results suggest a complete mediation impact of dissociation on symptom complexity. Conclusion : This study validated that childhood interpersonal trauma impacts symptom complexity, through the sequential mediating impact of dissociation. Thus, clinicians should understand childhood interpersonal trauma, dissociation, and symptom patterns in a complex and interacting mode, and develop effective pertinent treatment strategies.

Damage detection technique in existing structures using vibration-based model updating

  • Devesh K. Jaiswal;Goutam Mondal;Suresh R. Dash;Mayank Mishra
    • Structural Monitoring and Maintenance
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    • 제10권1호
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    • pp.63-86
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    • 2023
  • Structural health monitoring and damage detection are essential for assessing, maintaining, and rehabilitating structures. Most of the existing damage detection approaches compare the current state structural response with the undamaged vibrational structural response, which is unsuitable for old and existing structures where undamaged vibrational responses are absent. One of the approaches for existing structures, numerical model updating/inverse modelling, available in the literature, is limited to numerical studies with high-end software. In this study, an attempt is made to study the effectiveness of the model updating technique, simplify modelling complexity, and economize its usability. The optimization-based detection problem is addressed by using programmable open-sourced code, OpenSees® and a derivative-free optimization code, NOMAD®. Modal analysis is used for damage identification of beam-like structures with several damage scenarios. The performance of the proposed methodology is validated both numerically and experimentally. The proposed method performs satisfactorily in identifying both locations and intensity of damage in structures.