• Journal of applied mathematics & informatics
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• 제42권3호
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• pp.695-708
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• 2024

In this paper we present a non-standard finite difference method for solving a fractional decay model. The proposed NSFDM is constructed by incorporating a non-standard denominator function, resulting in an explicit numerical scheme as easy as the conventional Euler method, but it provides very accurate solutions and has unconditional stability. Two examples from the literature are presented to demonstrate the performance of the proposed numerical scheme, which is compared to three methods from the literature. It is found that the method's estimated errors are extremely minimal, such as within the machine precision.

• 한국공간구조학회논문집
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• 제14권1호
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• pp.101-108
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• 2014

In order to overcome the key shortcoming of Hamilton's principle, recently, the extended framework of Hamilton's principle was developed. To investigate its potential in further applications especially for material non-linearity problems, the focus is initially on a classical single-degree-of-freedom elasto-viscoplastic model. More specifically, the extended framework is applied to the single-degree-of-freedom elasto-viscoplastic model, and a corresponding weak form is numerically implemented through a temporal finite element approach. The method provides a non-iterative algorithm along with unconditional stability with respect to the time step, while yielding whole information to investigate the further dynamics of the considered system.

• Journal of the Korean Data and Information Science Society
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• 제27권6호
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• pp.1661-1671
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• 2016

Risk analysis is a systematic study of uncertainties and risks we encounter in business, engineering, public policy, and many other areas. Value at Risk (VaR) is one of the most widely used risk measurements in risk management. In this paper, the Korean Composite Stock Price Index data has been utilized to model the VaR employing the classical ARMA (1,1)-GARCH (1,1) models with normal, t, generalized hyperbolic, and generalized pareto distributed errors. The aim of this paper is to compare the performance of each model in estimating the VaR. The performance of models were compared in terms of the number of VaR violations and Kupiec exceedance test. The GARCH-GPD likelihood ratio unconditional test statistic has been found to have the smallest value among the models.

• 한국정밀공학회지
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• 제22권12호
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• pp.117-123
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• 2005

This paper deals with the finite element model of the monitor fur the simulation of directional free drop tests such as the backward and vertex free drop as well as the associated free-drop experiment. The model was made for an unconditional stable solution fur the explicit integration algorithm. It was found through the comparison between simulation and experimental results that the general behaviors at the time of impact were observed to well correlate with each other in terms of acceleration, displacement, contact force and stress of monitor components.

• 아동학회지
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• 제27권6호
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• pp.107-121
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• 2006

Based on the 10 week filial therapy model developed by Landreth (1991) for parents in lower income families, this study used the pre- and post- test model applied to an experimental group of 9 individuals. The program was implemented in three hour sessions, once a week for eight weeks. T-tests were performed following the therapeutic program. Results were that all four subcategories of parent's acceptance capability (respect for children's emotion and emotional expression management, understanding of children's unique temperament, understanding of children's desire for autonomy, and unconditional love for children) showed statistically significant differences between the pre- and post- tests (p< .001). Differences between the pre- and post test on parents' stress approached significance.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.267-268
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• 2015

The multi-environment probability density function model has been applied to simulate the turbulent $CH_4/H_2$ flames under MILD conditions. The direct quadrature method of moments (DQMOM) has been adopted to solve the transport PDF equation due to its computational efficiency and robustness. The IEM model represents the micromixing process. The numerical results obtained in this study are precisely compared with experimental data in terms of unconditional means and conditional means for scalar field including temperature and species mass fraction.

• 사회복지연구
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• 제45권3호
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• pp.179-207
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• 2014

본 연구는 사회복지관의 성과지향적 문화가 사회복지사의 직무수행에 어떠한 영향을 미치는지 살펴보는데 연구의 목적이 있다. 이러한 연구 목적을 달성하기 위해 2013년 1월 4일부터 1월 31일까지 부산 경남 지역의 사회복지관에 근무하는 사회복지사 1,162명을 대상으로 우편설문을 실시하였다. 그리고 회수된 설문 가운데 81개 사회복지관의 755명 자료를 최종 분석하였으며, 분석을 위해서는 SPSS 21.0, AMOS 21.0, 그리고 HLM 6.02 통계 패키지를 활용하였다. 다층모형의 기초모형, 무조건기울기모형, 조건모형 분석결과, 사회복지사의 직무만족도와 조직몰입도는 직무수행에 정적(+) 영향을 미치는 것으로 나타났다. 둘째, 성과지향적 문화의 하위 요인 중 고객지향성은 직무수행에 정적(+) 영향을 미치는 것으로 나타난 반면, 실적지향성은 직무수행에 부적(-) 영향을 미치는 것으로 나타났다. 그러나 혁신지향성은 직무수행에 아무런 영향을 미치지 않는 것으로 나타났다. 이상의 결과를 바탕으로 사회복지사의 직무수행도를 높이기 위한 조직문화 관리 방안을 도출하였다.

• 한국시스템다이내믹스연구
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• 제7권1호
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• pp.147-172
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• 2006

With the purpose of long-range planning toward local/regional sustainable development, it is desired to avoid unconditional industrialization and expansion and to build an eco-oriented development strategy considering site-specific characteristics of the environment. This paper thus aims at the elaboration of a system dynamics model of a locality/region so as to understand inherent dynamics of sustainable development and to assess the effectiveness of such an eco-oriented strategy. The model thus consists of several positive and negative feedback loops that accelerate or restrict local/regional economic growth within a system boundary incorporating the environment, economy, and society. The model is moreover applied to the assessment of the effectiveness of the development plan recently established in Damyang in JeollaNamdo, Korea. It is regarded in this case to be effective for population immigration and economic prosperity to give priority to restore the bamboo ecosystem and nourish a series of eco-friendly industries based on the bamboo items developed recently. It is also to be positive to sustainable development since it enables to maintain high quality of the environment from the outset of their development steps.

• 한국산학기술학회논문지
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• 제21권6호
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• pp.275-285
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• 2020

본 연구는 시간이 지남에 따라 학교에 대한 학생인식의 변화를 추적하고, 교육복지우선지원사업 참여 여부가 그 변화를 어떻게 설명하는지, 변화의 결과가 학생들의 학습몰입, 자신감, 교우관계에 어떠한 영향을 미치는지 분석하는 것을 목적으로 한다. 교육복지정책중점연구소에서 2015년부터 2017년까지 전국 총 103개 학교(초등학교 51개, 중학교 52개)로부터 수집한 자료를 활용하였다. 1차년도의 표본 수는 총 820명, 2차년도는 911명, 3차년도는 837명이었다. 본 연구는 무조건 성장 모형(unconditional growth model)과 조건 성장 모형(conditional growth model)의 두 단계를 거치는 잠재성장모형을 적용하여 분석하였다. 분석 결과 첫째, 교육복지우선지원사업 참여 학생들의 학교에 대한 인식은 시간이 지남에 따라 성장선을 보여주었다. 둘째, 학교에 대한 학생인식의 개선은 학생들의 학습몰입, 자신감, 교우관계에 모두 정(+)적인 영향을 미치는 것으로 분석되었다. 향후, 교육복지우선지원사업의 효과성을 극대화하기 위해서는 학교에 대한 인식 개선을 목적으로 하는 프로그램을 교사 주도로 교육복지우선지원사업 대상 여부에 관계없이 모든 학생에게 제공하며, 집중지원이 필요한 학생에 대해서는 교육복지사 중심으로 맞춤형 통합지원 프로그램을 제공하는 것이 바람직하다는 제언을 제시하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.183-184
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• 2014

The multi-environment probability density function model has been applied to simulate the turbulent stratified premixed flames. The direct quadrature method of moments (DQMOM) has been adopted to solve the transport PDF equation due to its computational efficiency and robustness. Computations are made for the non-swirling turbulent stratified premixed flames including SWB1, SWB5 and SWB9. The numerical results obtained in this study are precisely compared with experimental data in terms of axial velocity, unconditional means and conditional means for scalar field including temperature and species mass fraction.