• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.95-98
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• 2003

Computer aided simulation is becoming an essential part in planning, design, and operation of railway systems. To determine the adequate performance and specification of railway system, it is necessary to calculate rolling stock's performance such as distance, speed, power etc when train's running. This paper presents result of train performance simulation using the program that developed in advance for Korea high speed train. To verify result of simulation, we have developed measurement system and compared simulation result with experiment data.

• Journal of Information Technology Applications and Management
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• 제9권3호
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• pp.47-56
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• 2002

A variety of enterprises have Implemented ERP system on the promises of feasible strategic benefits. The objectives of this study are (1) to classily and analyze the motives and critical success factors o the enterprises'ERP system adoptions, and (2) to measure their impacts on the business performance. The data for this research were collected from 43 cases in Korea that have operated ERP system for more than 6 months after the implementation. This study results reveals that the Information strategic planning and business strategy establishment prior to ERP adoption and the demands of field people activate as critical triggers In the larger firms Among the six critical success factors, training was statistically significant for all of four performance measures control, cost reduction, quality and service, and work efficiency. And other findings are furnished. Also the larger company group In the sales volume has shown the higher performance except work efficiency.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.932-935
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• 2007

According to Urban Railroad Act, trains can be operated only after they take The Urban Transit Performance Test. There has been Performance Tests for the trains which has been manufactured since 2000, but it is nearly impossible to utilize the Performance Test results other than the original purpose due to the fact that they are not organized in detail, In addition, test steps have difficulty using the former test results. Thus, test results must be computerized and made into database to make the best use of them and to carry out efficient and dependable tests. For this purpose, this paper analyzes the task and the procedure of the performance test on trains. On the basis of the analysis results, this paper checks the availability of the computerized information and the possibility of improving the task concerned

• 보건의료산업학회지
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• 제14권2호
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• pp.15-27
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• 2020

Objectives: The purpose of this study is to compare analysis of financial performance in university hospitals. Methods: Data from 2005 to 2017 were collected from income statement, balance sheet, and annual reports in 23 university hospitals. The dependent variables are used financial performance, namely, medical profit to total assets, medical profit to medical revenue, and net profit to medical revenue. The independent variables are establishment type, hospital province, bed, open liquidity, stability, and activity. Results: From 2005 to 2007, university hospitals steadily increased medical revenues, nonmedical revenues, medical profit, net profit, and reserve fund for essential business by investing fixed assets using financial leverage. From 2015 to 2017, the debt ratio was minimized based on existing management performance. Results showed that university hospitals maintained high profitability by actively investing in medical equipment, medical environment, and facilities using reserve fund for essential business. Conclusions: Results suggest that this will be the basic data for efficient management of university hospitals.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 추계학술발표대회
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• pp.917-918
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• 2009

This study evaluated the level of performance improvement in the form of a simulated experiment by adding fixed node in the middle of the network as a way to improve mobile ad.hoc network performance. The result showed that the performance level was much higher when fixed node was used together than when mobile node was used only, and the comparison of the mobile speed of mobile node also showed that use of fixed node together had higher performance. Moreover, the evaluation in accordance with the number of fixed node showed that more number of fixed node had shorter time delay. Further study following this on how many fixed node should be added on the ad.hoc network will ensure establishment of more reliable ad.hoc network.

• Journal of information and communication convergence engineering
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• 제14권1호
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• pp.21-25
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• 2016

N-screen is a promising technology to improve support for multimedia multicasting, content sharing, content mobility, media scalability, and seamless mobility. In this paper, the WiMedia distributed-MAC (D-MAC) protocol is adopted for development of a seamless N-screen wireless service. Furthermore, to provide a multi-hop, one source multi-use N-screen service through point to point streaming in a seamless D-MAC protocol, a dynamic multi-frame transmission technology is proposed. In this technology, a dynamic time slot allocation scheme and a multi-hop resource reservation scheme are combined. In the proposed dynamic time slot allocation scheme, two thresholds, a hard threshold and a soft threshold, are included to satisfy the power consumption and delay requirements. A multi-frame DRP reservation scheme is proposed to minimize end-to-end delay during the multi-hop transmissions between N-screen devices. The proposed dynamic multi-frame transmission scheme enhances N-screen performance in terms of the multi-hop link establishment success rate and link establishment time compared to the conventional WiMedia D-MAC system.

• Journal of Communications and Networks
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• 제14권4호
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• pp.418-428
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• 2012

With the requirement for providing multiple levels of access control for group members, many group key management schemes designed for hierarchical access control have been put forward. However, most of these schemes focus on the efficiency of group key establishment and rekeying in centralized environments. This paper proposes an integrated group key agreement (IGK) scheme for contributory environments. The IGK scheme employs the integrated key graph to remove key redundancies existing in single key trees, and reduces key establishment and rekeying time while providing hierarchical access control. Performance analyses and simulations conducted with respect to computation and communication overheads indicate that our proposed IGK scheme is more efficient than the independent group key agreement scheme.

• 대한의생명과학회지
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• 제10권4호
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• pp.523-528
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• 2004

The core factor of the study is integrated environment based PC-Cluster system and high speed access rate up to 155 Mbps, continuous collection system for bioinformatics information at home and abroad. The results of the study are establishment and stabilization of information and communication infrastructure, establishment and stabilization of high performance computer network up to 155 Mbps, development of PC-Cluster system with 32 nodes, a parallelized BLAST on Cluster system, which can provides scalable speedup in terms of response time, and development of collection and search system for bioinformatics information.

• Journal of Ginseng Research
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• 제32권4호
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• pp.337-340
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• 2008

Seedlings of North American ginseng (Panax quinquefolius L.) were grown to full canopy establishment and then leaflet or leaf removal at different times applied to determine the effects on plant growth and performance. Leaf removal at 47, 57, 69 and 78 days after seeding resulted in 82.1, 59.8, 41.3 and 29.8% reduction, respectively, in root dry matter (economic yield) ; this indicates that leaf removal during the early root growth period causes greatest reduction in root yield. Removal of 1, 2, and 3 leaflets at 42, 52, 62 and 70 days from seeding reduced root weight at harvest (80 days from seeding) linearly, particularly at earlier removal dates. The perennating bud formed on all roots and was not influenced by treatment. This would suggest that if leaf loss occurs after canopy establishment the plant will re-grow the next year after the obligatory dormancy period.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1425-1428
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• 2004

Internal traffic system becomes fast with high-speed railway. Therefore, skill development for speed elevation is consisting in general railroad. New skill that is car report lake system is examined in railroad signal field. Therefore, examined establishment way and problem of car report lake system equipment. Examine equipment performance and studied method of most suitable that use.