• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.69-71
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• 2007

최근 들어 전력 계통은 점차 복잡해지고 계통의 규모 역시 빠른 속도로 성장하고 있다. 한국전력거래소는 전력계통의 안정적, 경제적 운영을 담당하고 있는 기관으로 '01년 현재의 에너지관리시스템(EMS)를 도입하여 실시간 전력계통에 대한 정확한 판단을 기반으로 전력계통의 안정성과 경제성 확보에 주력하고 있다. EMS의 대표적인 기능은 계통데이터의 수집(SCADA), 자동발전제어(AGC), 계통해석(NA) 등으로 대별되며, 이중 계통해석 기능은 프로그램 규모면에서 가장 큰 부분을 차지하고 있다. 계통해석 기능은 또다시 상태추정(SE), 상정사고분석(CA), 안전도해석(SENH), 고장해석(SCT) 등의 프로그램으로 구성되어 다양한 실시간 계통해석을 수행하게 된다. 전력계통 해석은 먼저 대상계통을 수학적 모델로 정식화하기 전에 계통망의 기하학적 구조를 기술하는 단계가 필요한데 이를 토폴로지 처리라고 하며, 보통 그래프이론인 노트(Node)와 마디(Branch)를 사용하여 전력계통망을 구성하는 요소들의 연결관계를 정의하게 된다. 본고는 이론적 수준을 넘어 EMS의 계통해석 기능에서 실계통을 해석하기 위해 쓰이고 있는 토폴로지 처리의 기본 알고리즘을 분석하여 국내 전력산업 기술 선진화에 기여하고자 한다.

• Journal of Digital Convergence
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• v.9 no.4
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• pp.143-156
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• 2011

To accomplish these purposes, First, this research divided hallmark of the environment friendly agricultural products into organic products and pesticide-free products and participants are classified as having promotion or prevention regulatory focus. In addition, consumer value type is categorized into value of social psychology and functional value. Second, construal level divided into high and low on the relationships between the consumer value and purchase intention. The main factors of the consumer value such as value of social psychology and functional value were found from the previous studies. This study is meaningful that the fit of regulatory focus between hallmark of organic products and pesticide-free products in environment friendly agricultural products. The regulatory relevance could moderate the level of persuasion knowledge activation. Also, This research is meaningful that the fit of construal level theory between Consumer value and purchase intention by person's psychological personality. The construal level relevance could moderate the level of marketing activation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.249-257
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• 2011

In this paper, an systematic approach is presented, in which the mixed variational theorem is employed to incorporate independent transverse shear stresses into a classical higher-order shear deformation theory(HSDT). The HSDT displacement field is taken to amplify the benefits of using a classical shear deformation theory such as simple and straightforward calculation and numerical efficiency. Those independent transverse shear stresses are taken from the fifth-order polynomial-based zig-zag theory where the fourth-order transverse shear strains can be obtained. The classical displacement field and independent transverse shear stresses are systematically blended via the mixed variational theorem. Resulting strain energy expressions are named as an enhanced higher-order shear deformation theory via mixed variational theorem(EHSDTM). The EHSDTM possess the same computational advantage as the classical HSDT while allowing for improved through-the-thickness stress and displacement variations via the post-processing procedure. Displacement and stress distributions obtained herein are compared to those of the classical HSDT, three-dimensional elasticity, and available data in literature.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.678-686
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• 2021

A smiling face usually has a positive effect on interpersonal relationships by delivering a warm impression. However, the stereotype content model and compensation effect between warmth and competence suggested that warmth perceptions caused by a smiling face could influence competence perceptions negatively. This study examined the negative impact of the advertising endorser's smile on purchase intention in an expensive product category by adopting the self-construal level. The study results showed that consumers with independent-self construal (vs. interdependent self-construal) showed a lower purchase intention when exposed to an ad containing an endorser's smile. In comparison, consumers with interdependent-self construal (vs. independent self-construal) showed a lower purchase intention when exposed to an ad without an endorser's smile. Thus, this study demonstrated a moderating role of self-construal in the relationship between advertising endorser's smile and purchase intention. These findings provide valuable theoretical and practical implications for effective advertising strategies in the expensive product category.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.381-387
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• 2016

In this paper, the methodology applied to the improvement of stress analyses is extended to free vibration and buckling analyses. The essence of the methodology is the Saint-Venant's principle that is applicable to beam and plate models. The principle allows one to dimensionally reduce three-dimensional elasticity problems. Thus the methodology can be employed to vibration and buckling as well as stress analysis. First, the principle is briefly revisited, and then the formations of classical beam theories are presented. To improve the predictions, the perturbed terms (unknowns) are introduced together with the warping functions that are calculated by stress equilibrium equations. The unknowns are then calculated by applying the equivalence of stress resultants (i.e., Saint-Venant's principle). As numerical examples, cantilever and simply supported beams are analytically solved. The results obtained are compared with those of the classical beam theories. It is shown that the methodology can be used to improve the predictions without introducing shear correction factors.

• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.161-167
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• 2001

It is difficult to obtain accurate fracture toughness values using three point bending test(TPB) proposed by RILEM committees because the shape of load-deflection curve is irregular and final crack propagation occurs after some slow stable cracking. However, fracture toughness is easily obtained from crack initiation load in the disk test. In this paper, the fracture properties of high strength concrete disks with center-crack was investigated. For this purpose, the experimental results were compared with the results by finite element analysis(FEA). And the experimental fracture locus was compared with theoretical fracture locus. Also, the results of fracture properties for the degree of concrete strength are presented. It is concluded from this study that results from FEA with maximum stress theory were compared well with the results from experiment. And the degree of concrete strength was contributed to the crack initiation load and fracture toughness, but was not contributed to the failure angle. Also, The discrepancy of fracture locus between the maximum stress theory and the experiment for concrete is considered to depend upon a large energy requirement for inducing the mixed-mode and sliding mode fractures.

• Journal of Technology Innovation
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• v.26 no.3
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• pp.98-128
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• 2018

This study aimed to investigate the performance on technology collaboration of small and medium enterprises in Korea from the views of resource-based theory. Considering that supplementing the technical resources is stressed in a motivation of technology collaboration from the corresponding theoretical perspective, a group of corporations to be analyzed was classified into three categories such as high, medium and low technologies depending on the technology level. Moreover, technology collaboration partners were also classified into large corporation, small and medium enterprises, university and institution based on that both tangible and intangible assets that belong to a corporation semi-permanently, and the revolutionary performance was analyzed by each relationship of collaboration between parties. The study results revealed that an influence on the performance of technology collaboration varies by technology level of the small and medium enterprises in Korea and their collaboration partners. In particular, the small and medium enterprises of high-tech industry in Korea were confirmed to accomplish relatively less benefits obtaining through technology collaboration compared to the corporations with low technical skills.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.29 no.10
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• pp.44-46
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• 2000

자연환기를 건물에 적용하는 주된 목적은 "실내 환경수준을 충족시키기 위해 필요한 초기투자 및 유지비용을 절감하기 위해서" 이다. 따라서, 합리적인 환경계획을 수립하기 위해서는 "자연환기를 적용하는 것이 유효한가\ulcorner 유효하다면 어떤 전략을 채용할 것인가\ulcorner" 하는 것이 계획단계에서 반드시 검토되어져야 한다. 설계자는 합리적인 판단을 위해서 다양한 정보를 필요로 하게되며 이 과정에서 다양한 해석도구가 이용될 수 있다. 본보에서는 자연환기 설계단계에서 요구되는 각종정보와 그 해석도구의 특성에 대하여 고찰해 보고자 한다.

• Journal of the KSME
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• v.34 no.5
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• pp.384-391
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• 1994

지금까지 고분자 재료에서의 일반적인 파괴역학 연구실태를 집약해보았다. 이 분야의 연구결과 들은 금속의 파괴역학 문제와는 다른 새로운 문제점을 지니고 있었다. 우리는 여기서 잘 짜여진 문제의 해를 구했다기 보다는 문제를 정의하는 수준에 있음을 느낄수 있었다. 더욱이 고려되고 있는 문제들조차 서로 독립적으로 연관성을 보이고 있지 못하다. 접근방법이 너무 이론적이어서 실제상황에 적합하지 않거나 실험적인 검증이 요구되고, 경우에 따라서는 경험적이어서 해석 적인 정량화가 필요한 경우가 많다. 의심할바 없이 이것이 고분자재료 파괴역학의 현실이며 앞 으로 좀더 많은 해석적, 실험적 연구가 이루어져 상황이 개선될 것으로 믿는다.

• Journal of Digital Contents Society
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• v.18 no.3
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• pp.475-483
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• 2017

This study attempted to investigate how the effectiveness of value-oriented promotion for media contents depends on self-construal and incorporated Schwartz' value system theory(1992) and Gutman's means-end chain theory(1982) into the development of hypotheses. It was expected that media content promotion emphasizing "openness to change" value would be more appealing to those with independent self-construal, whereas media content promotion emphasizing "conservation" value would be more appealing to those with interdependent self-construal. These hypotheses were generally supported in a series of experiments. Also, the dynamic relationship among the four primary value dimensions proposed by Schwartz (i.e., openness to change, conservation, self-enhancement, self-transcendence) was clearly validated in this study.