• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.141-160
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• 2006

In order to obtain and maintain competitive advantage, under rapidly changing maritime environment, liners should make efforts to reinforce their logistics service capabilities. Most of all, for this, shipping lines should accurately recognize and evaluate their logistics service attributes. In the present research, various logistics service attributes for ocean carriers were selected from previous studies and the observed data for 6 main service attributes were collected through a questionnaire survey to 31 maritime experts. Moreover, shipping lines' relative logistics service capabilities were measured by an additional survey process. The comparative gravity between core evaluation factors were measured by AHP technique and the relative capability levels of 2 Korean liners and 5 foreign shipping companies were assessed by utilizing a fuzzy model. The empirical result presents that Korean liners are superior at customer service capability but inferior at freight rate competitiveness. This research shows that Korean liners are ranked at high position for overall logistics service capabilities and focusing on the differentiation strategy but not on the cost related strategy.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.19-30
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• 2009

Recent development in wireless communication technology and mobile equipment like PDA, cellular phone and GPS makes location-based services (LBSs) popular. However, because, in the LBSs, users continuously request a query to LBS servers by using their exact locations, privacy information could be in danger. Therefore, a mechanism for users' privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, this paper propose a grid-based cloaking area creation scheme supporting continuous LBSs. The proposed scheme creates a cloaking area rapidly by using grid-based cell expansion to efficiently support the continuous LBSs. In addition, to generate a cloaking area which makes the exposure probability of a mobile user to a minimum, we compute a privacy protection degree by granting weights to mobile users. Finally, we show from a performance analysis that our cloaking scheme outperforms the existing cloaking schemes, in terms of service time, privacy protection degree.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.101-108
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• 2024

The total number of railroad stations managed in Korea is 322 (including general and wide-area railways), and a considerable number of stations are aging. In terms of the size of the existing railway station and the number of entrances, it has not been possible to secure adequate service capacity, and the demand for station improvement is increasing due to changes in surrounding conditions such as urban development. In the past, railroad stations were focused on the simple function of a connection passage in terms of maintenance or management, but in recent years, railroad stations are also changing to an atmosphere that they should be reborn as a user-centered comfortable, convenient, and safe service provision space. In this study, a case study related to the improvement of the old railway station was conducted to derive an improvement plan that meets the improvement standard of the old station, and the service level evaluation standard was developed. By introducing the concept of service level (LOS) in the development model, station congestion, station movement convenience, and station safety were selected as evaluation indicators. In addition, this development model applied an analytical stratification technique to divide various evaluation elements of each indicator into major and detailed elements and derive the relative importance of the elements by class. Priority for improvement was derived using the ratio of the number of E and F on the LOS for each facility. Based on this study, it is expected to be helpful in using it as an evaluation criterion for improving objective and equitable railway station.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.3
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• pp.129-145
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• 2016

This paper analyzed and compared the service level and satisfaction of the sidewalks in collector roads from 6 different location, which has a lot of volume of pedestrians. For the study, it performed an investigation of road geometry, flow, research about satisfaction of walking and video recording. Based on this data, this study computed the service level of the sidewalks and pedestrian satisfaction. This study made a sense of correlation between service level and satisfaction. Also it focused on factors influencing on the effectiveness of satisfaction. This study also analyzed the change of walking behavior chracteristics according to the change of the level of satisfaction. This study adopted Multi-Modal Level of Service(MMLOS) method, because it could consider more factors. This study reached the conclusion that MMLOS method cannot completely reflect the level of pedestrian satisfaction. We have to consider more factors than in the current system for use in the development of sidewalk design. The result of this study is expected to reflect the pedestrian satisfaction in future sidewalks design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.8-17
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• 2017

Infrastructures such as bridges and tunnels are crucial elements of national economic growth, and sudden collapses may lead to great catastrophes with significant social and economic losses, as well as a loss of lives. Hence, an efficient maintenance technique must be applied to guarantee safety, secure budgets to maintain a certain level of service, and prevent maintenance expenditures from being concentrated in a specific time period. Developed countries have experienced rapid increases in maintenance budgets, and maintenance costs now account for about 40% of the total maintenance budget. The level of service in asset management systems is an essential element for setting management goals and making priority decisions. Therefore, this study uses fuzzy theory to develop a new way to assess the level of service.The assessment model was applied to an actual bridge to evaluate the level of service for users.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.216-219
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• 2011

이 기종의 컴퓨팅 자원들로 구성된 데이터센터에서 사용자가 제출한 클라우드 작업의 서비스 품질을 보장하기 위해서는 효율적인 작업할당 기법이 필요하다. 본 논문에서는 작업의 처리시간을 사용자의 QoS 로 정의하고 작업처리시간을 최소화하면서 동시에 모든 사용자에게 차별 없이 동일한 수준의 서비스를 제공할 수 있는 최적 작업할당 문제를 정의한다. 협력적 게임모형인 NBS(Nah Bargaining Solution)을 이용하여 정의한 문제를 해결하였고 이를 이용하여 각 자원에 할당되는 작업부하를 효율적으로 제어함으로써 파레토 최적을 유지할 수 있는 협력적 부하분산 정책을 도출하였다. 또한, 성능 평가를 통해 제안한 기법이 작업처리시간을 최소화하면서도 모든 자원에서의 작업처리시간이 동일함을 보였다.

• Journal of Advanced Navigation Technology
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• v.20 no.2
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• pp.141-147
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• 2016

Stable and reliable air traffic service is required for users (aircraft pilot, air traffic controller, airlines and public) through enhancing capability related to airport operation and continuously improving air navigation system. ASMS (air navigation service provider (ANSP) safety maturity survey) is to determine the level of management and safety requirement such as organization, risk, policy, process, training and environment in Air traffic service field. We designed and developed the survey (26 study areas of management part and 23 study areas of safety part) considering global best practices (Eurocontrol and FAA) and customizing domestic circumstances with quantitative level assessment regarding management and safety issue of Air navigation system. The survey enables the performance of Air navigation system to enhance and prevents from occurring accident or incident. Therefore, we provides best information with users as well as high quality Air traffic service.

• Journal of Korean Society of Transportation
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• v.24 no.4 s.90
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• pp.129-148
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• 2006

The objective of this thesis is to develop a capacity analysis and to develop a methodology to evaluate Level of Service over the entire freeway sections by single MOE (Measure of Effectiveness) This study set forth from a following viewpoint. to analyze entire freeway sections as freeway facility system, it is important to identify the exact point where congestion would occur and the extent of the congestion. Therefore, in this thesis, congestion mechanism on freeways was figured out and congestion analysis methodology was developed. Thereby maximum possible throughput rate and maximum throughput rate in bottleneck sections were calculated and a congestion analysis was carried out. The difference between the new method and existing Procedures is that maximum possible throughput rate and maximum throughput rate. that can be considered as capacities of un-congested and congested flow in the bottleneck section, are variable capacities dependent on demand flow.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1028-1034
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• 2005

The purposes of this study were to: (a) identify students' patronage behaviors on university foodservice, (b) evaluate customers' perception and detect complaints on food service quality, and (c) recommend new design of food service operation by identifying relative importance of university foodservice attributes. The questionnaire was developed and distributed to 400 undergraduates. Statistical data analysis was completed using SPSS/Win 12.0 for descriptive analysis and conjoint analysis. The results of this study were summarized as follows: Students were patronizing university foodservice 3.4 times per week because of 'a short distance', 'a low price' and 'speedy meals' and evaluated overall satisfaction and value as low level. Customers were dissatisfied with eight among twelve food service attributes including handling customer's complain ASAP, According to conjoint analysis, price $(37\%)$ was considered as the most important factor and atmosphere $(30\%),\;food\;(22\%)$ and distance $(11\%)$ were the next factors. Profile 2, which had 4 attributes of a location within 6-10 min, comfortable circumstances, a meal served with 4 side-dish and dessert and a meal price of \2,000 firstly, were recommend as new food service operation model.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.159-161
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• 2000

본 논문에서는 부하제어 서비스 클래스와 같이 결정적인 수준의 보장을 지원할 수 없는 연결 구조를 이중화하여 실시간 RPC의 종료시한 만족도를 개선하는 기법을 제안하고 그 성능을 평가한다. 제안된 기법은 RPC의 여유시간에 따라 요청 혹은 응답 메시지 전송에 있어서 종료시한 만족가능성이 높은 연결을 선택하도록 함으로써 각 RPC 트랜잭션에 여유시간에 따른 우선순위를 부여할 수 있으며 분할 기준치의 효율적인 선택에 의해 성능의 향상을 기할 수 있다. 이를 위해 할당된 대역폭에 따른 최적의 분할 기준치를 통계적으로 추정하여 실험 결과와 비교하였다. SMPL을 기반으로 수행된 모의실험은 제안된 기법이 실험에서 주어진 인자값에 대해 실시간 RPC의 종료시한 만족도를 개선할 수 있으며 통계적으로 0.3% 이내에서 최적의 분할 기준치를 추정할 수 있음을 보인다.