• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.423-436
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• 2011

Many of the theoretical studies have considered herd behavior as a source of the volatility in financial markets, but there have been few empirical studies on the dynamic herding due to the technical difficulty of detecting herd behavior with time-series data. In this context, this paper proposes a new method for measuring time-varying herd behavior based on QR-GARCH model. Using daily data of KOSPI stocks, this paper provides some empirical evidence for strong and volatile herding among traders of stocks of medium firms, and shows that time-varying herd behavior in traders of some stocks has persistent autocorrelation.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.105-111
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• 2005

Recently, global terminal operotors are struggling to attract more cargoes into their ports through enlarging facilities and trying to be more efficient operotion Many researches on container terminal efficiency have been conducted, but most of the traditional studies are focused on the partial efficiency of the container terminal using quantitative questionnaires and basic statistical data In this paper, the Stochastic Frontier Model of the interaction among the variables was employed to execute numerical analysis on the efficiency of terminal. The objective of this paper is to measure the level of efficiency in the container terminals every year and to assess the influence in container terminal's efficiency on domestic and foreign terminals by changing the terminal scales and the level of input factors.

• The Korean Journal of Applied Statistics
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• v.21 no.6
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• pp.1077-1091
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• 2008

In this study, we consider to assess the information ability of individuals related to local information. Questionnaire surveys are frequently used for studies on the measuring of information index and such specified indexes of society development. However, if questionnaire papers measured individuals' abilities and such parts of quality, the subjective judgments of respondents cannot but be intervened. Therefore a method which will enable subjective points to be comparatively objectified is needed. In this study, when an attempt is being made to measure individuals' information capacity through questionnaire surveys as the process for calculating the standards of regional information levels. Cases have been looked at for times when, by using a scorecard, individuals' subjective survey result have been be changed to be comparatively objectified scores and such process. The logit model was used in the preparation of the scorecard. In this study, we have presented a clue which enables the comparative measurement about regional information gaps by using characteristics of regional population statistics.

• Journal of Science and Technology Studies
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• v.12 no.2
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• pp.1-31
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• 2012

Rapid globalization process is applying to Science field in Korea. Until now, most researches and government's announcement used to examine the scientific level of Korea by using the number of publications in the SCI Journals. I investigate other aspects of the scientific globalization: a scientific collaboration trend, participations of foreign researchers, and the national level of collaboration networks. There are increasing patterns in collaboration and foreign researchers' participation, and the Impact Factors of the Journals were preceded by inflating trend in the participations of foreign researchers. Also, the breadth and the density are different from each science fields in the national level of collaboration networks. These findings are related to the process of globalization in the Korean science journals and the science fields.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.44-54
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• 2011

Intelligent transport services on smart roads tend to have a problem at the stage of benefit-cost analysis that can not secure economic feasibility of the new services which increase early investment cost on building its infrastructure. It is expected that the number of road accidents, 'Incident/Accident', will decline through various safety services using intelligent safety facilities, intelligent transport management and so on, and that traffic congestion will also decrease. The effect of traffic congestion reduction could be the benefit by safety improvement, however current investment-analysis process in Korea does not appropriate it as a benefit. This study estimated road blocking time with 'Incident/Accident' classification and highway accident data of past three years. It also developed a generalized model by a regression analysis with a microscopical simulation. Furthermore, it suggested necessary units on quantitative analysis in order to make the developed model applicable to investment evaluation. As a result of applying the developed model to Smart-Highway Project, it showed that total safety improvement benefit is about 139 billion dollars over 30 years when it is supposed that accident decreasing rate by smart safety facilities is 10%.

• Journal of Digital Convergence
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• v.16 no.7
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• pp.1-8
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• 2018

In Korea, water supply capacity and facility investments had been emphasized around the 1980s. The water pricing have gained focuses in water policy since the 1990s. This study analyzes a water demand and estimates the relation of water demand and other socio-economic variable, using econometric models on the city of Busan. Water price and income are two key elements to explain water demand. Modeling approach using translog function provides better results, and water demand responds positively to population and income. Energy and water prices are negative factors in deciding water demand. It is requested that water pricing needs to reflect more production costs. Alternative approaches such as water saving facilities by household and use of digital water information should be emphasized for efficient water management in a local community.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.622-628
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• 2016

The aim of this study was to clarify how the role stress of administrative workers in medical institutions affects burnout, job satisfaction, and organizational commitment. The study conducted surveys on administrative workers at ten general hospitals with more than 200 beds for one month between July 13 and August 18, 2015. The surveys then underwent factor analysis, average variation extraction, a suitability index of the research model, and a path-coefficient estimation analysis of the research model using AMOS 18.0. The main results revealed a positive (+) effect according to the role conflict and role excess on burnout, and a negative (-) effect of burnout on job satisfaction, while they displayed no significant relationship with organizational commitment. These results suggest that clear guidelines and unity in instructions are needed to reduce the role of stress in cooperative tasks between departments and that optimizing the roles of organization members by accurately measuring and weighing tasks can increase the attachment to the organization and ultimately improve the individual job performance.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.187-196
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• 1999

The increasing interest in the use of Automated Speed Enforcement (ASE) systems in Korea enables to enforce speed violation by National Police Agency. We have analyzed the mechanism of ASE systems on traffic safety throughout Korea. 1 The data collected on a 2km road-section of each 32 ASE stations during one rear period indicate significant safety improvement. The results were (a) a decrease in the total number of accidents of 28%, (b) a decrease in the number of fatalities of 60%. 2. The study also that ASE systems are effective to reduce average speed, speed variance, and short headway. 3. Based on the operational data collected at 15 locations, an aggregate safety prediction model is proposed as a multiple regressions form. The primary operational variables that appear to affect the frequencies of accident are : average speed, speed variance, and the number of vehicles exceeding 30km/h of posted speed limit.

• Journal of the Korean Regional Science Association
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• v.35 no.1
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• pp.47-57
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• 2019

Daegu Metropolitan City has been continuously carrying out core functions of Yeongnam region, and especially plays a role as export base of textile and chemical products in Korea. Also Daegu Metropolitan City has contributed greatly to the expansion of Korea's import and export trade and the growth of the national economy. The purpose of this study is to analyze the influence of major factors affecting GRDP in Daegu Metropolitan City through regression analysis. For this purpose, this study uses the Vector Error Correction Model(VECM) to estimate the long-run equilibrium function that affects the GRDP in Daegu Metropolitan City. This study is meaningful in that it uses the statistics related to Daegu provided by Province of Gyeongsangbuk-do and explains the dynamic characteristics of major factors affecting the GRDP in Daegu.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.697-710
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• 2021

Relative error prediction is preferred over ordinary prediction methods when relative/percentile errors are regarded as important, especially in econometrics, software engineering and government official statistics. The relative error prediction techniques have been developed in linear/nonlinear regression, nonparametric regression using kernel regression smoother, and stationary time series models. However, random effect models have not been used in relative error prediction. The purpose of this article is to extend relative error prediction to some of generalized linear mixed model (GLMM) with panel data, which is the random effect models based on gamma, lognormal, or inverse gaussian distribution. For better understanding, the real auto insurance data is used to predict the claim size, and the best predictor and the best relative error predictor are comparatively illustrated.