• Title, Summary, Keyword: 해석수준이론

Search Result 192, Processing Time 0.036 seconds

Analysis of EMS NETWORK Topology Algorithm (EMS NETWORK Topology 알고리즘에 대한 연구)

  • Yu, Hyun-Jung;Choi, Young-Min;Kim, Min-Bae;Kim, Kwang-Ho;Park, Yong-Jo;Kim, Sung-Hak
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.69-71
    • /
    • 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.

  • PDF

The Effect of Hallmark of the Environment Friendly Agricultural Products on the Consumer Value and Purchase Intention - Centering around the Moderating Effect of Regulatory Focus and Construal Level (친환경농산물의 인증마크가 소비자가치와 구매의도에 미치는 영향 - 조절초점과 해석수준의 조절효과를 중심으로)

  • Lee, Seung-Hee;Han, Sang-Bak;Do, Hyeon-Ok;Seo, Kyeong-Do
    • Journal of Digital Convergence
    • /
    • v.9 no.4
    • /
    • pp.143-156
    • /
    • 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.

The Effect of Temporal Distance on Risk Perception and Behavioral Intention : Based on Email Phishing (시간적 거리가 위험지각 및 행동의도에 미치는 영향 : 이메일 피싱을 중심으로)

  • Jung, Koeun;Min, Yoonki
    • Journal of the Korean Data Analysis Society
    • /
    • v.20 no.5
    • /
    • pp.2605-2618
    • /
    • 2018
  • The purpose of this study is to investigate the effect of psychological distance on risk perception and intention to behavior that directly cause risk. In each study, participants were informed about email phishing at each temporal frame. After that assessed their perceived risk (study 1), or indicated their intention to behaviour to protect personal information (study 2). As results, when the temporal distance is close, the risk of email-phishing is perceived as a high level despite the same information except for the temporal frame where the information was presented. Further, it was confirmed that social distance as another dimension of psychological distance interacts with temporal distance. In addition, when an e-mail requests personal information, the intention to behavior is lower than when it is not, and this difference is greater in the 'day' frame in which the temporal distance is close. These results support the construal level theory, suggesting that perception of the risk and the intentions of the behavior causing the risk may be different depending on temporal distance.

On the Modification of a Classical Higher-order Shear Deformation Theory to Improve the Stress Prediction of Laminated Composite Plates (적층평판의 응력해석 향상을 위한 고전적 고차전단변형이론의 개선)

  • Kim, Jun-Sik;Han, Jang-Woo;Cho, Maeng-Hyo
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.24 no.3
    • /
    • pp.249-257
    • /
    • 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.

Improvement of Euler-Bernoulli Beam Theory for Free Vibration and Buckling Analyses via Saint-Venant's Principle (생브낭 원리를 이용한 고전 보 이론의 고유진동수 및 좌굴하중 예측 개선)

  • Jeong, Yong-Min;Kim, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.40 no.4
    • /
    • pp.381-387
    • /
    • 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.

A Study on the Effect of Technology Collaboration on Innovation Performance of SMEs: From the Views of Resource-based Theory (중소기업의 기술협력이 혁신성과에 미치는 영향에 관한 연구: 자원기반이론 관점에서)

  • Bong, Kang Ho;Park, Jaemin;Kim, Jae Young
    • Journal of Technology Innovation
    • /
    • v.26 no.3
    • /
    • pp.98-128
    • /
    • 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.

Investigating the Effect of Value-Oriented Promotion for Media Contents: The Moderating Role of Self Construal (미디어 콘텐츠에 대한 가치 지향적 프로모션의 효과 분석 : 자기해석수준의 차이 를 중심으로)

  • Cho, Hyong-Oh;Nam, Chul-Woo
    • Journal of Digital Contents Society
    • /
    • v.18 no.3
    • /
    • pp.475-483
    • /
    • 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.

Fracture Mechanics in Polymers (고분자 재료에서의 파괴역학)

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

  • PDF

An Investigation of a Country-Level Diagnostic Assessment Model for the TIMSS (국제 수학·과학 성취도 추이 연구 분석을 위한 국가 수준 진단평가 모형 탐색)

  • Park, Chanho
    • Korean Journal of Comparative Education
    • /
    • v.28 no.5
    • /
    • pp.1-19
    • /
    • 2018
  • The purpose of educational assessments such as the Trends in International Mathematics and Science Study (TIMSS) is to compare groups such as countries. When the unit of measurement is above the student level, group-level diagnostic assessment based on multilevel item response theory (ML-IRT) can be considered just as cognitive diagnosis models are developed from item response theory. This study suggests an ML-IRT-based group-level diagnostic assessment model by modifying an item feature model by Park and bolt (2008). The model is illustrated on the recently released TIMSS 2015 Grade 8 mathematics assessment. The results provide skill profiles for the studied countries and the nine cognitive attributes; that is, the attribute effects can be compared across the countries and also across the attributes. By controlling unexplained variance, the suggested model may provide more reliable and more informative group-level comparisons. The results are interpreted using an example. Limitations and directions for future research are also discussed.

Inter-country Analysis on the Financial Determinants of Corporate Cash Holdings for the Large Firms With Headquarters in the U.S. and Korea (한국과 미국 대기업들의 현금유동성 보유수준에 대한 재무적 결정요인 분석)

  • Kim, Hanjoon
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.6
    • /
    • pp.504-513
    • /
    • 2017
  • This study investigated one of the controversial issues on debate or even controversial between policy makers at the government and corporate levels: To examine any financial determinants on the cash holdings of the firms in the advanced and emerging capital markets. Futhermore, it focused on the large representative firms headquartered in the U.S. and the Republic of Korea, taking into account scarcity of the previous literature concentrated on the comparative studies on this particular subject. Several legitimate, but robust econometric estimations such as static and dynamic panel data models and Tobit regression, were applied to investigate possible financial factors ono the cash liquidity. Given the continued debates or arguments on the excess cash reserves between interest partied at the government and corporate levels in the advanced and/or emerging capital markets, and more accelerated capital transfers among associated nations by engaging in the arrangements of the FTAs, the results of the study may provide a vision to search for the optimal level of corporate cash holdings for firms in the two nations.