• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.57-66
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• 2003

Because the Logit model easily calculates probabilities for choice alternatives and estimates parameters for explanatory variables, it is widely used as a traffic mode choice model. However, this model includes an assumption which is independently and identically distributed to the error component distribution of the mode choice utility function. This paper is a study on the estimation of the Heteroscedastic Logit Model. which mitigates this assumption. The purpose of this paper is to estimate a Logit model that more accurately reflects the mode choice behavior of passengers by resolving the homoscedasticity of the model choice utility error component. In order to do this, we introduced a scale factor that is directly related to the error component distribution of the model. This scale factor was defined so as to take into account the heteroscedasticity in the difference in travel time between using public transport and driving a car, and was used to estimate the travel time parameter. The results of the Logit Model estimation developed in this study show that Heteroscedastic Logit Models can realistically reflect the mode choice behavior of passengers, even if the difference in travel time between public and private transport remains the same as passenger travel time increases, by identifying the difference in mode choice probability of passengers for public transportation.

• Environmental and Resource Economics Review
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• v.13 no.4
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• pp.685-715
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• 2004

This study applies two-choice model to identify the major determinants of NIMBY attitudes when a large-scale composting facility is built around a residential area. Using a survey data of residents in Jeju City, Korea, logit estimation is implemented. The empirical results are consistent with the implication of the specified model: a representative resident's NIMBY attitude is positively (negatively) affected by "Negative Neighborhood Characteristic Variables" ("Positive Wealth Attribute variables"). Socio-demographic variables may be summarized as mostly statistically insignificant, which implies that policy makers may have to take into consideration their region-specific socio-demographic factors instead of simply emulating the policies which have been successful elsewhere.

• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.69-78
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• 1999

This paper defines the reliable based route choice Principle and formulates the reliability based equilibrium traffic assignment using the Principle. The reliability is defined as the difference of travel demand and capacity using the interference theory of the system engineering. An efficient solution a1gorithm based on Frank-Wo1fe algolithm is Presented to calculate and compare the reliability based traffic assignment with conventional travel time based assignment using small and large scaled road networks. The results show that reliability based traffic assignment converges to equilibrium solution in a reasonable computing time. The equilibrium link flows between reliability and travel time based traffic assignment differ each other in the sense that reliability based assignment is assigned based on the maximum difference of travel demand and link capacity whilst travel time based is assigned on the shortest travel time.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.11-17
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• 2009

Purpose: The purpose of this study is to provide an empirical overview of the import patterns of the Eyeglasses and Contactlens industry. Methods: This study used an Engle-Granger cointegration technique and Johansen's multivariate cointegraion methodology test to check the stationarity of the model. This paper also applies Rolling regression to our model, indicating that Eyeglasses and Contact Lens import is endogenous to the economic variable. Results: The empirical results show how the import in Eyeglasses and Contact Lens is related to the economic variables. Conclusions: This paper shows how the import of Eyeglasses and Contactlens is influenced by economic variables, such as exchange rate and industrial product, and seasonal factors.

• Journal of Korean Society of Transportation
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• v.34 no.2
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• pp.135-145
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• 2016

This study assumes a vehicle choice model based on the multinomial model and analyzes the vehicle choice behaviors of consumer. An SP survey targeting drivers was implemented and data was collected for model estimates, with the possible choice options of the survey takers limited to gasoline, HEV, PHEV, and EV vehicles. The explanatory variable mostly displayed a significance level of under 5%, and excluding variables for price and fuel the remaining variables were all consistent with the logical direction with the plus (+) sign and the results were determined to be rational. Consumers selecting mid-size & full-size vehicles are able to afford more than consumers that selected other vehicle types, so there was relatively little consideration given to low fuel costs when compared to vehicle price. For this reason, it was determined that for the full-size vehicle model the fuel variable could be disregarded. Socio-economic variables that were statistically significant were the age and infor variables for the sub-compact & compact, the age, infor and inc3 variables for the mid-sized & full-size vehicles.

• Journal of the Korean Society for Library and Information Science
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• v.36 no.2
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• pp.89-117
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• 2002

The purpose of this study is to construct a model for measuring and assessing service quality in public libraries based on the theory of service quality in marketing area. Firstly the degree of importance of service factors is measured and ranked according to the value of each factor. This importance ranking indicates the order of service improvement. Secondly the correlation model between service factors and customer's satisfaction and behaviour is established and verified in statistical method. The result shows that the order of service quality factors which have influence on the customer's satisfaction and behaviour is the order of service quality factors required preferential improvement.

• Journal of agricultural medicine and community health
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• v.28 no.1
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• pp.1-13
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• 2003

Objectives: The purpose of this study is to summarize results from 11 domestic studies about sick role behavior applied health belief model and to assess the effectiveness of components on behavior change by using meta-analysis. Methods: We collected the existing literatures by using major web search of 'pulmonary tuberculosis patients', 'health belief model', and 'sick role behavior' as key words and by reviewing content of journals. Quantitative meta-analysis was performed by SAS program. Results: Among 66 articles, 11 studies were selected for quantitative meta-analysis. The knowledge level about pulmonary tuberculosis had more effect for only sick role behavior as general characterisitcs(d=0.7870). All the components of health belief model produced significant effects on sick role behavior with the magnitude of effect size from 0.31 to 0.73. The largest effects were benefits on actions of sick role behavior. Conclusions: Overall, these investigation provide very substantial empirical evidence supporting health belief model dimensions as important contributors to the explanation and prediction of sick role behavior among the type of health related behavior in pulmonary tuberculosis patients. Strategic intervention including health education, etc. based on health belief model showed clear advantage in improvement of behavioral change.

• Journal of Korean Society of Transportation
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• v.21 no.5
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• pp.97-110
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• 2003

The sight distance at unsignalized intersections is the one of the fundamental geometric design elements, and can ensure safety and efficient operations. Despite its importance, little research attention has been directed in Korea compared to developed countries such as European countries, the United States, and Japan. AASHTO ISD policies have been applied to the intersection design in Korea without any revise, which can produce unrealistic and unadoptable design values. Those values are emerged from several reasons because the AASHTO ISD has been calibrated based on the local data. Therefore the ISD hardly takes into account the local characteristics of Korea such as driving behavior. vehicular movement and roadway conditions. The objective of this study is to calculate the appropriate ISD values for unsignalized intersections in the urban area in Korea. In this study, we employed the ISD model of AASHTO(2001), which is based on gap acceptance theory and can account for and take the driving and roadway conditions in Korea into consideration. The approach can also consider the complex driving maneuvers at the intersections in a proper and simple manner. The results in this study show that the ISD design criteria currently used in Korea are more conservative(safer) than those of the USA. In other words, the ISD using field data collected in this study has generally smaller values than those in USA.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.65-79
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• 2006

The ATIS(Advance Traveler Information System), as one part of ITS, is a system aiming to disperse traffic volume on transportation networks by providing traffic information to transportation users on pre-trip and en-route trips. One of tools in ATIS is usage of VMS(Variable Message Signs). It provides to the drivers with direct information about state of processing direction. which is considered as the most effective method in ATIS. The purposes of providing VMS information are classified two categories. One is to provide simple information to drivers for their convenience. The other is to manage traffic demand to improve transportation network performance. However, for more effective and reliable VMS information, several strategies should be taken into account. The main VMS management strategy is "Traffic Diversion Strategy for minimum delay" when traffic congestion or incident are occurred. For effective operation. firstly. reasonable diversion traffic volume is determined by network traffic condition Secondly, it is necessary to make providing information strategy which reflects driver response behavior for controling diversion traffic volume. This paper focuses on the providing real-time route guidance information by VMS when congestion is occurred by the incidents. This sturdy estimates time-dependent system optimal diversion rate that inflects travel time and queue lengths using traffic flow simulation model on base Cellular Automata. In addition, route choice behavior models are developed using binary logit model for traffic information variable by traffic system controller. Finally, this study provides time-dependent VMS massage contents and degree of providing information in order to optimize the traffic flow.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.26-36
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• 2008

Currently, the pedestrian signal timing model has no consideration on the characteristics of different land use patterns and pedestrian behaviors during pedestrian signal timing calculation. This study intended to propose pedestrian signal timing models that could reflect the inherent characteristics of pedestrian and land use patterns. For this study, three major variables affecting the length of signal timing were identified: walking speed, perception-reaction time, and density-delay time. Then, the representative values of each variable were estimated through the field studies. By combining this information, several pedestrian signal timing models were developed. The data in this paper can be used for future references, and the walking environments for pedestrians could be improved by applying the models suggested in this paper.