• Title/Summary/Keyword: 인과 모형 분석

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Comparison between a 3 Dimensional Turbulent Numerical Model and Hydraulic Experiment Model for the flow phenomenon around a Lock Gate (배수갑문 주위의 흐름현상에 대한 3차원 난류 수치모형과 수리모형실험의 비교)

  • Lee, Sang-Hwa;Jang, Eun-Cheul;Ha, Jae-Yul
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.2
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    • pp.162-169
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    • 2007
  • This study is focused on the comparison of a 3 dimensional numerical and hydraulic model experiment for the flow phenomenon when a lock gate is opened. The lock gate is designed to discharge the flood flow rate at $218m^3/s$ of Solicheon at the Kun Jang national industry complex. The three dimensional ${\kappa}-{\epsilon}$ turbulent model of ANSYS CFX-10 of the computational fluid dynamics(CFD) program was used. The characteristics of CFX-10 are able to be simulated effectively for turbulent flow, especially the flow separation of the boundary layer of the two phase interface of air and water. The velocity and the flow pattern of the numerical model was showed to be similar to the results of the hydraulic model experiment.

A Study on Prediction Model for Laundry and Toilet Water-use demand (세탁기 및 화장실 용수 수요량에 대한 예측모형 연구)

  • Myoung, Sung-Min
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.4
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    • pp.327-335
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    • 2019
  • This study develops a prediction model for toilet and laundry water end-uses based on surveyed data which measured housing and household characteristics of 140 households over 5 years in Korea. Classical regression model assuming a normal distribution was not appropriate and estimated parameters were biased, because the distribution of measured water-uses was left-skewed. As an alternative to this problem, we considered the distribution of weibull and lognormal for each water-uses, and three regression models were compared using log-likelihood and scale parameter. As a result, weibull regression were chosen to be appropriate for both water-uses and also presented the factors that affect each water-use. This results expect that an insight is provided on water resources utilization and theoretical support role for effective water resource management.

Applying Rasch Analysis for Validation of School Function Assessment (학교기능평가(School Function Assessment)도구의 구성타당도 검증을 위한 라쉬분석의 적용)

  • Park, Kyoung-Young
    • The Journal of the Korea Contents Association
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    • v.14 no.3
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    • pp.269-276
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    • 2014
  • The purpose of this study is to investigate validation of the School Function Assessment(SFA) for Korean Version using Rasch analysis. The subjects were recruited 98 students with disabilities in Seoul, Kyoung-Ki, Chung-cheung. The data were analysed using Rasch analysis to investigate unidimensionality and rating scale model. The 4 items out of SFA Part II were found to be misfts. The 18 items out of physical tasks, the 14 items out of cognitive/behavioral tasks in Part III were found to be misfit. All rating scale in SFA was appropriate. Further studies are needed to investigate validity and criterion cut-off score for many students with disabilities.

A Study on the Influence of the Space Syntax and the Urban Characteristics on the Incidence of Crime Using Negative Binomial Regression (음이항 회귀모형을 이용한 공간구문론 및 도시특성요소가 범죄발생에 미치는 영향 연구)

  • Kim, Hyeong Jun;Choi, Yeol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.2
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    • pp.333-340
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    • 2016
  • The aim of this study is to specifically understand the characteristics of the crime by empirical analysis for the determining factors that affect determining the crime through the space syntax in Busan. In this study, poisson regression and negative binomial regression were used for accurate analysis. 8 variables that were significant of the total 13 variables. The summary if this study based on the results is as follow. Statistically significant variables are female ratio, over 65 population ratio, administration are and commercial area ratio in characteristics. And the more CCTVs a region has, the lower crime rate it shows. As a results of examing whether space syntax variables can predict crime occurrence places. Space with low connectivity come to be a crime causal factor because they have few other related spaces and thereby have low possibility of sudden appearance of interrupters, which results in low surveillance levels of foot passengers. It will provide the basic data that can contribute to urban planning and implementation of crime prevention aspects.

Inferring the Transit Trip Destination Zone of Smart Card User Using Trip Chain Structure (통행사슬 구조를 이용한 교통카드 이용자의 대중교통 통행종점 추정)

  • SHIN, Kangwon
    • Journal of Korean Society of Transportation
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    • v.34 no.5
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    • pp.437-448
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    • 2016
  • Some previous researches suggested a transit trip destination inference method by constructing trip chains with incomplete(missing destination) smart card dataset obtained on the entry fare control systems. To explore the feasibility of the transit trip destination inference method, the transit trip chains are constructed from the pre-paid smart card tagging data collected in Busan on October 2014 weekdays by tracing the card IDs, tagging times(boarding, alighting, transfer), and the trip linking distances between two consecutive transit trips in a daily sequences. Assuming that most trips in the transit trip chains are linked successively, the individual transit trip destination zones are inferred as the consecutive linking trip's origin zones. Applying the model to the complete trips with observed OD reveals that about 82% of the inferred trip destinations are the same as those of the observed trip destinations and the inference error defined as the difference in distance between the inferred and observed alighting stops is minimized when the trip linking distance is less than or equal to 0.5km. When applying the model to the incomplete trips with missing destinations, the overall destination missing rate decreases from 71.40% to 21.74% and approximately 77% of the destination missing trips are the single transit trips for which the destinations can not be inferable. In addition, the model remarkably reduces the destination missing rate of the multiple incomplete transit trips from 69.56% to 6.27%. Spearman's rank correlation and Chi-squared goodness-of-fit tests showed that the ranks for transit trips of each zone are not significantly affected by the inferred trips, but the transit trip distributions only using small complete trips are significantly different from those using complete and inferred trips. Therefore, it is concluded that the model should be applicable to derive a realistic transit trip patterns in cities with the incomplete smart card data.

A study on the relationship between the onshore and offshore Chinese Yuan markets (중국 역내·외 위안화 현물시장간의 상호 연계성 연구)

  • Lee, Woosik;Chun, Heuiju
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.6
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    • pp.1387-1395
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    • 2015
  • Since the financial crisis of 2008, the People's Republic of China has aggressively been pursuing the internationalization of the Chinese Yuan or Renminbi. In this regard, rapidly increasing use of the Chinese Yuan in the onshore and offshore markets are important milestones. This paper analyzes relationship between the onshore and offshore Chinese Yuan spot markets. Major findings of this paper are as follows : First, there is full feedback relationship between the Onshore and Offshore Chinese Yuan Markets. Second, the difference between the yuan's offshore exchange rate and the onshore was getting tight. Third, the offshore Yuan market affects on the onshore market based on the empirical tests.

Effects of Fisheries Technological Innovation on Growth per Capita across OECD Countries (수산부문 기술혁신이 OECD 회원국의 성장률에 미친 효과)

  • Lee, Yoonsuk;Chang, Jae Bong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.349-357
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    • 2017
  • The environmental problems affecting marine resources and slow growth in the fisheries industry is causing many countries to look for alternative inputs that can boost the fisheries sector. This study focuses on the effects of technological innovation in the fisheries industry on the gross domestic product (GDP) per capita across Organization for Economic Cooperation and Development (OECD) countries. Using a panel dataset, this study attempts to estimate the different effects of technological innovations in the fisheries industry from country to country using the differences-in-differences (DiD) method. After the DiD method, the Granger causality test is applied to determine the interactive relations between economic growth and the selected variables associated with technological innovation in the fisheries industry, such as government spending on fisheries R&D, the number of patents in fisheries, and employment. The results obtained from the DiD estimation show that government spending on fisheries R&D, fisheries technology development, and fisheries employment positively influences the GDP per capita across OECD counties. From the causality test, we found different bi-directional causal relationships between the GDP per capita and (spending) on fisheries technology development across countries.

Does Pygmalion Leadership Play a Role in the Process of Public Organization members' Self-Efficacy and Organizational Commitment to Customer Orientation? (공공조직 구성원의 자아효능감과 조직몰입이 고객지향성에 미치는 과정 중 피그말리온 리더십이 작용하는가?)

  • Na, Kyung-Soo
    • The Journal of the Korea Contents Association
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    • v.21 no.10
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    • pp.356-367
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    • 2021
  • This study is a study on how much organizational leadership influences customer orientation so that it can secure and maintain a continuous competitive advantage in the rapidly changing environment of corporate management and public organizations. it was approached through theoretical consideration of pygmalion leadership. The purpose of this study is as follows. First, a conceptual definition of the three research variables of pygmalion leadership and its constituent atmosphere, feedback, and output is given. Second, the casual relationship between the conceptually defined three research variables of pygmalion leadership and self-efficacy and organizational commitment was verified. Third, the casual relationship was verified on the extent to which pygmalion leadership influences customer orientation through self-efficacy and organizational commitment, which are parameters. Fourth, through the verification result of the casual relationship between the research variables constituting the research model of this study. It was intended to present an implication. In addition, the significance of direct causal relationships between the research variables of pygmalion leadership, mediating variables, and dependent variables, which constitute the verified research models was verified, and the results of hypothesis testing were presented, and the academic and practical implications of the results of this study were presented.

The Influence of Social Media Trust through Perceived Risk and Self-efficacy on Brand Trust (소셜미디어 신뢰가 지각된 위험과 자아효능감을 통한 브랜드 신뢰에 미치는 영향에 관한 연구)

  • Na, Kyung-Soo
    • The Journal of the Korea Contents Association
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    • v.22 no.4
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    • pp.58-69
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    • 2022
  • The purpose of this study is to find a way that companies can use social media trust effectively to increase brand trust and intelligently increase it by linking with brand authenticity. Therefore, the purpose of this study is as follows. First, a conceptual definition of the research variables of trust in social media, trust in information sources, and trust in messages is established, Second, the casual relationship between two conceptually defined independent variables and mediator variables of perceived risk and self-efficacy was verified. Third, the casual relationship was verified on whether it affects brand authenticity and brand trust through perceived risk and self-efficacy, which are mediators of social media trust. Fourth, through the verification result of the casual relationship between the research variables constituting the research model of this study, it was intended to present academic and practical implications on how social media trust can effectively enhance brand trust.

PDA Personalized Agent System (PDA용 개인화 에이전트 시스템)

  • 표석진;박영택
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2002.11a
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    • pp.345-352
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    • 2002
  • 무선 인터넷을 이용하는 사용자는 정보의 양의 따른 시간적 통신비용의 증가 문제로 개인화 에이전트가 사용자의 관심에 따라 서비스를 제공하는 기능과 맞춤화된 정보를 제공하는 기능, 지식 기반 방식으로 정보를 예측하는 기능을 가지기를 바라고 있다. 본 논문에서는 이와 같이 무선 인터넷을 사용하는 사용자를 위한 PDA 개인화 에이전트 시스템을 구축하고자 한다. PDA 개인화 에이전트 시스템 구축을 위해 프로파일 기반의 에이전트 엔진과 사용자 프로파일을 이용한 지식기반 방식을 사용한다. 사용자가 웹페이지에서 행하는 행위들을 모니터링하여 사용자가 관심 가지는 문서를 파악하고 정보 검색을 통해 얻어진 문서를 분석하여 사용자 각각의 관심 문서로 나누어 서비스하게 된다. 모니터링 되어진 문서를 효과적으로 분석하기 위해 unsupervised clustering 기계학습 방식인 Cobweb을 이용한다. unsupervised 기계 학습은 conceptual 방식을 이용하여 검색되어진 정보를 사용자의 관심 분야별로 clustering한다. 클러스터링을 통해 얻어진 결과를 다시 기계학습을 통해 사용자 관심문서에 대한 프로파일을 생성하게 된다. 이렇게 만들어진 프로파일을 룰(Rule)로 만들어 이를 기반으로 사용자에게 서비스하게 된다. 이러한 룰은 사용자의 모니터링 결과로 얻어지기 때문에 주기적으로 업데이트하게 된다. 제안하는 시스템은 인터넷신문이나 웹진 등에서 사용자들에게 뉴스를 전달하기 위한 목적으로 생성하는 뉴스문서를 특정 대상으로 선정하였고 사용자 정보를 이용한 검색을 실시하고 결과로 얻어진 정보를 정보 분류를 통해 PDA나 휴대폰을 통해 사용자에게 제공한다. 상품을 검색하기 위한 검색노력을 줄이고, 검색된 대안들로부터 구매자와 시스템이 웹상에서 서로 상호작용(interactivity) 하여 해를 찾고, 제약조건과 규칙들에 의해 적합한 해를 찾아가는 방법을 제시한다. 본 논문은 구성기반 예로서 컴퓨터 부품조립을 사용해서 Template-based reasoning 예를 보인다 본 방법론은 검색노력을 줄이고, 검색에 있어 Feasibility와 Admissibility를 보장한다.매김할 수 있는 중요한 계기가 될 것이다.재무/비재무적 지표를 고려한 인공신경망기법의 예측적중률이 높은 것으로 나타났다. 즉, 로지스틱회귀 분석의 재무적 지표모형은 훈련, 시험용이 84.45%, 85.10%인 반면, 재무/비재무적 지표모형은 84.45%, 85.08%로서 거의 동일한 예측적중률을 가졌으나 인공신경망기법 분석에서는 재무적 지표모형이 92.23%, 85.10%인 반면, 재무/비재무적 지표모형에서는 91.12%, 88.06%로서 향상된 예측적중률을 나타내었다.ting LMS according to increasing the step-size parameter $\mu$ in the experimentally computed. learning curve. Also we find that convergence speed of proposed algorithm is increased by (B+1) time proportional to B which B is the number of recycled data buffer without complexity of compu

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