• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.25-28
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• 2008

Korean city had been rapid developed through high industrialization and rapid economic growth after the 1970's. The city development process was guaranteed the fulfillment of city function through the city expansion based on New Towns and satellite cities rather than the reformation of existing city. This city expansion caused by degrading of city, being backward and producing many problems. To solve this problems, it was considered the rehabilitation of retarded function with rejuvenation such as a special law accelerating urban renaissance and reorganization project. Also a fire protection performance did not satisfied the required conditions of modern FPP system, such as the function deterioration of building facilities, the technological development with FPP facilities, changed fire laws and building occupancy for social needs. Insufficiency of requirements depreciated the building value and intimidated a safety of residents. To solve this problem, the improvement of FPP was essentially required and also strongly recommended an analysis and a comparative study between the required FPP of existing building and it improving effective FPP. Therefore, purpose of this study is that establish the basic data to construct a system to analyze and compare the building FPP.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1B
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• pp.176-182
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• 2010

In this paper, we propose an adaptive I/Q diversity combining scheme which reduces unnecessary computations while maintaining the required performance level. The system with the proposed scheme adaptively applies a proper combining scheme among the conventional selective scheme and combining scheme based on the comparison result between the estimated instantaneous SNR and the pre-determined threshold. As a result, the system with our proposed scheme can reduce the computational load while maintaining the required performance level. Some selected simulation results show that the system with the proposed scheme can decrease the unnecessary computations compared with the system with the conventional schemes while maintaining the required performance level.

• Journal of the Korean Solar Energy Society
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• v.29 no.1
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• pp.50-57
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• 2009

Heliostat in the tower type solar thermal power plant is a mirror system tracking the sun's movement to collect the solar energy and it is the most important subsystem determining the efficiency of solar thermal power plant. Thus a good performance of it, which is mostly the accurate sun tracking performance under the various hazardous operating condition, is required. Heliostat control system is a system to manage the heliostat sun tracking movement and other operations. It also communicates with the master controller through the heliostat filed control system to receive and send the informations required to operate the heliostat as a part of the solar thermal power plant. This study presents a heliostat control system designed and developed for the 1MW solar thermal power plant. We first define the functionality of heliostat control system. Then sun tracking controller as well as the sun tracking algorithm satisfying the required functionality have been developed. We tested the developed heliostat control system and it showed a good performance in regulation of heliostat motion and communication.

• Journal of Information Technology Services
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• v.20 no.6
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• pp.151-162
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• 2021

Since 2012, the Navy has been conducting a defense experiment project to evaluate the possibility of military application by introducing new technologies related to excellent private informatization in the defense field. There are many projects that have spread because they are suitable for military use, but some have ended as experimental projects themselves because they do not meet the military's required performance. Continuous development is required as increasing the spread rate by successfully carrying out defense experiment projects is the basis for defense reform. This study analyzed the performance of major projects carried out by the Navy and presented considerations for the development of defense experiment projects to be carried out by the Navy in the future. The main achievements were derived in various ways in terms of project performance and system operation, and the considerations can be summarized in the field of raising business requirements, securing resources for system operation, determining the size of companies for project execution, and security measures. The research results can be used as data to determine the required defense experiment project and efficiently carry out the project.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.14 no.1
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• pp.8-14
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• 2018

Printed circuit heat exchangers (PCHEs) are widely used with an increasing demand for industrial applications. PCHEs are capable of operating at high temperatures and pressure. We consider a PCHE as a candidate intermediate heat exchanger type for a high temperature gas-cooled reactor (HTGR). For conventional application using stainless steels, design and manufacturing of PCHEs are well established. For applications to HTGR, knowledge of longitudinal conduction and deformation of channel is required to estimate design margin. This paper analyzes the effects of longitudinal conduction and deformation of channel on thermal performance using a code internally developed for design and analysis of PCHEs. The code has a capability of two dimensional simulations. Longitudinal conduction is estimated using the code. In HTGR operating condition, about ten percent of design margin is required to compensate thermal performance. The cross-sectional images of PCHE channels are obtained using an optical microscope. The images are processed with computer image process technique. We quantify the deformation of channel with dimensional parameters. It is found that the deformation has negative effect on structural integrity. The deformation enhances thermal performance when the shape of channel is straight in laminar flow regime. It reduces thermal performance in cases of a zigzag channel and turbulent flow regime.

• Journal of Korea Multimedia Society
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• v.11 no.11
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• pp.1536-1546
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• 2008

RSVP-capable router supporting guaranteed services on the internet generally uses a packet scheduler based on the Weighted Fair Queuing (WFQ) algorithm to secure required qualities of traffic flows. A RSVP-capable router based on the LOFQ (Latency optimized fair queuing) algorithm had been proposed to improve the performance of the WFQ-based RSVP-router, but it required not only the RESV message to be expanded but also its performance could be evaluated only through simulation. This paper proposed a LOFQ based RSVP-capable router using the conventional RESV message and developed an algorithm to analyze the performance of the LOFQ based RSVP-capable routers. The performance evaluation using the developed algorithm showed that in terms of performance improvement the proposed router is inferior to the one using the expanded RESV message under a small packet size, but on the range of a large packet size both routers provide the same improvement.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.715-723
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• 2018

The energy storage system consists of batteries, power conditioning system and energy management system. If ESS is installed and operated in the field, SAT(Site Acceptance Test) of ESS is being essentially required for the safety and performance of ESS. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W equipments but also performance verification by S/W tool. Therefore, this paper proposes the modeling of portable test equipment in order to evaluate the performance and reliability of ESS by using the PSCAD/EMTDC S/W. And also, the prototype of 30[kW] scaled portable test equipments is implemented based on the S/W modeling. From the results of various simulations and testings such as power quality, LVRT and anti-islanding tests, it is confirmed that 30[kW] scaled portable test equipment is useful for SAT of ESS, because the simulation results of PSCAD/EMTDC are identical to them of 30[kW] test equipment at the same test conditions.

• Korean Journal of Applied Biomechanics
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• v.28 no.1
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• pp.61-67
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• 2018

Objective: The human body is often modelled as a spring-mass system. Lower extremity stiffness has been considered to be one of key factor in the performance enhancement of running, jumping, and hopping involved sports activities. There are several different classification of lower extremity stiffness consisting of vertical stiffness, leg stiffness, joint stiffness, as well as muscle and tendon stiffness. The primary purpose of this paper was to review the literature and describe different stiffness models and discuss applications of stiffness models while engaging in sports activities. In addition, this paper provided a current update of the lower extremity literature as it investigates the relationships between lower extremity stiffness and both functional performance and injury. Summary: Because various methods for measuring lower extremity stiffness are existing, measurements should always be accompanied by a detailed description including type of stiffness, testing method and calculation method. Moreover, investigator should be cautious when comparing lower extremity stiffness from different methods. Some evidence highlights that optimal degree of lower extremity stiffness is required for successful athletic performance. However, the actual magnitude of stiffness required to optimize performance is relatively unexplored. Direct relationship between lower extremity stiffness and lower extremity injuries has not clearly been established yet. Overall, high stiffness is potentially associate risk factors of lower extremity injuries although some of the evidence is controversial. Prospective injures studies are necessary to confirm this relationship. Moreover, further biomechanical and physiological investigation is needed to identify the optimal regulation of the lower limb stiffness behavior and its impact on athletic performance and lower limb injuries.

• Journal of Korean Physical Therapy Science
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• v.28 no.1
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• pp.54-61
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• 2021

Background: The present study was performed to examine the factors required for active engagement of participants in exercise therapy by surveying the frequency of participation, fidelity of performance, and supporting materials and rewards provided to encourage participation in the study. Design: Cross-sectional study. Methods: The survey was conducted in a population of 103 participants in at least one exercise treatment study. A 12-item questionnaire was designed to determine the frequency of exercise participation and fidelity of participant performance. Results: The results were subjected to frequency analysis and Pearson's correlation analysis. The subjects were less likely to exercise with the therapist and less likely to exercise at home. In addition, the provision of supplementary materials, to be considered when exercising at home, was insufficient. A strong positive correlation was found between the frequency of exercise in the presence of a therapist and the fidelity of participant performance (r=0.812, p=0.001), whereas a weak negative correlation was found between the frequency of unperformed exercises and the fidelity of participant performance (r=-0.523, p=0.023). Conclusion: The results of the present study suggested that it is necessary to increase the number of times that exercises are performed with the therapist to motivate increased frequency of exercise participation and fidelity of participant performance. In addition, appropriate rewards and periodic management are required.

• Journal of the military operations research society of Korea
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• v.33 no.1
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• pp.135-155
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• 2007

A performance specification states requirements in terms of the required results, such as performance, environment and interchangeability, but without stating the methods for achieving the required results, such as material and process. therefore the performance specification is applied to attain economic efficiency and high reliability by using the advanced commercial Technology for the weapon systems and The development of performance specification and conversion into performance specification have been activated in the advanced nations. The Ministry of National Defence of Korea has regulated the specification to make performance type in developing specification and prepared performance specification guide. but the result of the development of and conversion into performance specification is very unsatisfactory, To efficiently develop and convert into performance specification, this study gives the way of market research, the creation of the performance specification from development of weapon system and part localization, the process and method for conversion of detail specification into performance specification, the use of hybrid type of performance and detail specification.