• Steel and Composite Structures
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• 제27권6호
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• pp.727-745
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• 2018

The design criteria and the corresponding performance levels characterize the response of extended stiffened end-plate beam-to-column joints. In order to guarantee a ductile behavior, hierarchy criteria should be adopted to enforce the plastic deformations in the ductile components of the joint. However, the effectiveness of thesecriteria can be impaired if the actual resistance of the end-plate material largely differs from the design value due to the potential activation of brittle failure modes of the bolt rows (e.g., occurrence of failure mode 3 in the place of mode 1 per bolt row). Also the number and the position of bolt rows directly affect the joint response. The presence of a bolt row in the center of the connection does not improve the strength of the joint under both gravity, wind and seismic loading, but it can modify the damage pattern of ductile connections, reducing the gap opening between the end-plate and the column face. On the other hand, the presence of a central bolt row can influence the capacity of the joint to resist the catenary actions developing under a column loss scenario, thus improving the joint robustness. Aiming at investigating the influence of these features on both the cyclic behavior and the response under column loss, a wide range of finite element analyses (FEAs) were performed and the main results are described and discussed in this paper.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.373-376
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• 2006

In general, there are three kinds of methods in analyzing dynamic robust design experiment: loss model approach, response function approach, and response model approach. In this talk, we review the three modeling approaches in terms of several criteria in comparison. This talk also generalizes the response model approach based on a generalized linear model. We develop a generalized two-step optimization procedure to substantially reduce the process variance by dampening the effect of both explicit and hidden noise variables. The proposed method provides more reliable results through iterative modeling of the residuals from the fitted response model. The method is compared with three existing approaches in practical examples.

• Journal of the Korean Data and Information Science Society
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• 제24권1호
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• pp.41-51
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• 2013

정보화시대에 인터넷 중독의 심각성은 정보화 사회의 큰 이슈로 부각되고 있다. 인터넷사용이 급증함에 따라 정보화의 역기능도 증가하고 있어 인터넷 중독은 사회적문제로 대두되고 있다. 초고속 무선인터넷 서비스 보급 및 넷북, 스마트 폰 등의 인터넷 접속기기가 더욱 다양화됨에 따라 인터넷 중독 자가진단 검사 척도인 K-척도의 진단기준도 시대변화에 따라 변화가 요구되었으며 2012년 3월에 K-척도의 진단기준이 변경되었다. 본 논문에서는 2012년 변경된 K-척도의 기준으로 경북지역 대학생들의 인터넷 중독 실태와 K-척도 특징들을 살펴보고자 한다. K-척도에서 중독 진단을 위한 조사방식은 응답자가 직접 자신의 중독증상을 주관적 판단에 의해 응답하는 설문방식이므로 응답자의 고의적인 사실 숨김으로 인해 응답오차가 발생할 수 있다. 본 논문에서는 응답오차를 줄이기 위해 변경된 K-척도에 응답자에게 설문 응답에 대한 신뢰할 수 있는 신뢰도 값을 추가적으로 입력하여 분석의 신뢰도를 높이고자 한다.

• 대한기계학회논문집A
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• 제31권12호
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• pp.1165-1172
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• 2007

The spacer grid set is a part of a nuclear fuel assembly. The set has a spring and the spring supports the fuel rods safely. Although material nonlinearity is involved in the deformation of the spring, nonlinearity has not been considered in design of the spring. Recently a nonlinear response structural optimization method has been developed using equivalent loads. It is called nonlinear response optimization equivalent loads (NROEL). In NROEL, the external loads are transformed to the equivalent loads (EL) for linear static analysis and linear response optimization is carried out based on the EL in a cyclic manner until the convergence criteria are satisfied. EL is the load set which generates the same response field of linear analysis as that of nonlinear analysis. Shape optimization of the spring is carried out based on EL. The objective function is defined by minimizing the maximum stress in the spring while mass is limited and the support force of the spring is larger than a certain value. The results are verified by nonlinear response analysis. ABAQUS is used for nonlinear response analysis and GENESIS is employed for linear response optimization.

• 한국임상보건과학회지
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• 제7권2호
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• pp.1345-1354
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• 2019

Purpose: This study aimed to determine the mediating effects of aggressive stress response on the association between clinical practice stress and clinical practice satisfaction in ophthalmic optics majors and provide basic data that could help form opticians' professionalism and make clinical practice more effective. Methods: This study was conducted in 236 sophomores and juniors in Daegu and North Gyeongsang Province who had finished clinical practice. Hierarchical regression analysis and mediating effect testing were performed to determine the associations among clinical practice stress, clinical practice satisfaction, and aggressive stress response and determine the mediating effects of aggressive stress response on the association between clinical practice stress and clinical practice satisfaction. Results: Clinical practice stress was significantly negatively correlated with clinical practice satisfaction and aggressive stress response (p<0.01), and aggressive stress response was significantly positively correlated with clinical practice satisfaction (p<0.01). The association between clinical practice stress and clinical practice satisfaction was more likely to be explained by the addition of clinical practice stress than by being aggressive stress response controlled, which statistically significantly met the criteria for mediating effects (p<0.001). Conclusions: It is necessary to pay more attention to program development and teaching methods within the department of ophthalmic optics so that ophthalmic optics majors can utilize aggressive stress response to overcome clinical practice stress effectively and improve clinical practice satisfaction.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1071-1075
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• 2009

This article describes a robust control method by using peak control of a sensitivity function in the state-feedback control systems. This method apparently reduces the peak, and as a result makes closed loop systems more stable. The designed closed loop systems also make the response to an external step disturbance more fast with a lower undershoot. At the conclusion, it is verified that the proposed method enhances robust stability and robust performance to parametric uncertainties through $\mu$-plot.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.551-558
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• 2007

This paper presents a review guideline for evaluating SERPs(standard emergency response procedure) in rail accidents. In order to develope it, design elements of the SERPs, that impact the performance of emergency responding personnel, were identified. Then several review guidelines and standards, being used in other industries including nuclear domain, were surveyed. Finally, the review guides and criteria corresponding to those elements were derived from the survey.

• Journal of the Korean Statistical Society
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• 제8권1호
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• pp.37-64
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• 1979

Criteria and designs are developed for estimating derivatives of P-variable second order polynomial response surfaces. The basic criterion used is mean square error of the estimated derivative, averaged over all directions and then averaged over a region of interest. A new design concept called slope-rotatability is introduced. A simplex optimization program is used to find minimum mena square error designs for the two variable case for $6 \leq N \leq 12$.

• Communications for Statistical Applications and Methods
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• 제19권6호
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• pp.761-770
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• 2012

We frequently encounter outcomes of count that have extra variation. This paper considers several alternative models for overdispersed count responses such as a quasi-Poisson model, zero-inflated Poisson model and a negative binomial model with a special focus on a generalized linear mixed model. We also explain various goodness-of-fit criteria by discussing their appropriateness of applicability and cautions on misuses according to the patterns of response categories. The overdispersion models for counts data have been explained through two examples with different response patterns.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.694-699
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• 2007

The spacer grid set is a part of a nuclear fuel assembly. The set has a spring and the spring supports the fuel rods safely. Although material nonlinearity is involved in the deformation of the spring,nonlinearity has not been considered in design of the spring. Recently a nonlinear response structural optimization method has been developed using equivalent loads. It is called nonlinear response optimization equivalent loads (NROEL). In NROEL, the external loads are teansformed to the equivalent loads (EL) for linear static analysis and linear response optimization is carried out based on the EL in a cyclic manner until the convergence criteria are satisfied. EL is the load set which generates the same response no EL. The objective function is defined by minimizing the maximum stress in the spring while is limited and the support force of the spring is larger than a certain value. The results are verified by nonlinear. ABAQUS is used for nonlinear response analysis and GENESIS is employed for linear response optimization.