• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.320-323
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• 2009

There is many considerations of the composition development of propellant, performance analysis according to temperature, ablation condition of heat-resistant material, etc. in the solid rocket motor development process. Performance analysis of the motor according to nozzle expansion ratio is one of this process and an important factor to decide the motor performance. A Study is verified through anlaysis, motor manufacture and test.

• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.395-408
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• 2003

Common Channel Signaling(CCS) networks need special controls to avoid overload of signaling networks and degradation of call process-ing rate, since they play an important role of controlling communication transfer networks. Congestion control and flow control mechanisms are well described in ITU-T recommendation on Signaling System No.7(SS7). For the practical provisions, however, we need an analysis on the relation among service objects, system requirements and implementation of congestion control algorithms. SS7 provides several options for controlling link congestion in CCS networks. In this paper we give a general queueing model of congestion control algorithm which covers both the international and national options. From the queuing model, we obtain the performance parameters such as throughput, message loss rate and mean delay for the international option. To show the performance of the algorithm, some numerical results are also given.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2612-2615
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• 2008

Diaphragm seals have great effects on the performance of large power-generation steam turbines. Hence, it is important to decrease the leakage flow through the diaphragm seals and understand the flow characteristics within the diaphragm seals. In this study, numerical analysis was carried-out with the seals of large one-body type diaphragms developed by a domestic company. CFX, which is a commercial CFD code, was used to analyze the performance and flow characteristics of the diaphragm seals for three difference clearance cases. The results of numerical analysis show variations in the performance and flow characteristics according to the changes of labyrinth seal clearance.

• Journal of the Korea Safety Management & Science
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• v.9 no.4
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• pp.71-82
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• 2007

For a sustainable development, the resources circulation system should be established and an environment-conscious activities are required at the same time. These activities should be also implemented in logistics area. Especially, green procurement activities in inbound logistics is recognized as a very important factors in the early phase of an environment-conscious activities. In this paper, we are to suggest the direction through statistical analysis of effects, and cause of influences of environmental procurement logistics activities on logistics performance by environmental logistics strategy and by the size of enterprises, and by Environmental Management System. This study was conducted with the subjects of manufacturing enterprises with concurrent reviews of literature and statistical analysis, and the meaning of this study would be the analysis of the influencers of environment-conscious procurement logistics activities on logistics performance different from existing logistics studies.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.23-24
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• 2021

Since 2011, apartment houses account for about 41% of the fires in residential facilities for the past 10 years. Fire-resistant performance of fire doors is becoming more important to prevent the spread of fire in apartment houses. This research analyzed the structure of fire door through each 10 DB based on the quality inspection report of Continuous Acquisition & Life-cycle Support(CALS) from 2016 to 2020, which passed the fire performance test based on the laws and notices of domestic fire door. Therefore, based on the results of the analysis of DB in the future, we will conduct a study on structural improvement and addition for fireproof performance improvement of fire door.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.150-153
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• 2015

The construction industry is an integral part of any nation's economy, whether measured by dollar volume or workforce size. In spite of its strong influence, there has been very little specifically aimed at evaluating the current industry performance. This research investigates the macroeconomic performance of the construction industry by accounting for crucial performance affecting factors such as labor productivity and gross margin. A clustering analysis, followed by a series of statistical analyses, yielded a notable finding that labor productivity is the most important factor that affects industry's profitability. The results of the analysis also revealed that the states with the strongest labor productivity show the highest level of profitability in terms of gross margin. This study should be of value to decision-makers when plotting a roadmap for future growth and rendering a strategic business decision.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1040-1042
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• 2002

In general, satellite electrical power system plays an important role in its mission performance. To perform the mission successfully, the satellite should be provided with the sufficient power until end of life. In this paper shows that electrical boxes' design characteristic, energy balance analysis and power performance in satellite real operation.

• Journal of the Korean Data and Information Science Society
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• v.18 no.4
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• pp.973-983
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• 2007

Korea Military Academy has been using College Scholastic Ability Test(CSAT) and High School Grades(HSG) with other measures such as an Essay-type Test(ET), Physical Test(PT) and Personal Interview(PI) as criteria for entrance. The purpose of study is to investigate the properness of the criteria in admission decisions by examining the relationship between the college GPA and criteria, and the prediction of academic performance. The study showed that CSAT and HSG are significantly correlated with the college GPA, and these two criteria are better predictors for academic performance. Regression analysis also provided an important message that HSG is a better predictor than CSAT.

• Journal of Advanced Marine Engineering and Technology
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• v.11 no.1
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• pp.53-62
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• 1987

The Performance of Pre-combustion Chamber Diesel Engine mainly depends upon the compression, combustion and Expansion Processes. The analysis of varying tendency of the work factors for crank angles during these processes, which are consisted of 5 items such as exothermic energy, flow work, work in nozzle part, kinetic energy and cooling energy, are considered important as basic elements for effective combustion and performance improvement. In this paper, varying tendencies of the theoretical factors are investigated with pressure data through experiments. By the results, the trends of work factors are presented as basic data for comparing the influencing effects on work.

• Health Policy and Management
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• v.11 no.4
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• pp.54-69
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• 2001

This study was conducted to assess factors associated with the degree of performance of qualify improvement(QI) activities. A mailed questionnaire survey was conducted between September 15 and October 30, 2000, with the staffs being charge of QI at each of the hospitals with 400 beds or greater. Of the 108 hospitals eligible for inclusion in our study, 79 participated, yielding a response rate of 73.1%. After excluding 12 hospitals that did not perform any QI activities, 117 responses from 67 hospitals were used for the analysis. Using the Malcolm Baldrige National Quality Award Criteria(MBNQAC), perceived performance of QI was measured in terms of the improvement of the quality of clinical practice, clinical supporting department, administrative procedure of receiving care, customer satisfaction, efficiency and standardization of work process. Factors evaluated for the association were the extent of QI implementation, compliance to 5 QI principles, participation of hospital CEOs, budget allocation, history of QI, and bed size. Path analysis was performed to assess the relationship between QI performance and these factors. Major findings of this study are as follows. Hospitals showing higher degree of QI implementation (path coefficient=0.5967, p<0.001)) and better compliance with the basic principes of QI(0.5736, p<0.05) tended to achieve better performance. Path analysis results showed that interest and participation of hospital CEOs(0.1954, p<0.05) and compliance with the basic principes of QI(0.4028, p<0.0001) indirectly affected the outcomes of QI by influencing the intermediate variable of the level of QI implementation. This study results suggest that having employees have a good orientation of the basic concept and principes of QI through relevant training be the most important requirement to achieve better outcomes from QI activities. In addition, to educate leaders of hospitals the need of active implementation of QI is important to encourage their participation and draw strong support for QI programs.