• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1424-1429
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• 2004

To seek the fan operating point on a cooling system with fans, it is very important to determine the system impedance and it has been usually examined with the fan tester(wind tunnel) based on ASHRAE standard and AMCA standard. This leads to a large investment in time and cost, because it could not be executed until the system is made actually. Therefore it is necessary to predict the system impedance curve through numerical analysis so that we could reduce the measurement effort. This paper presents how the system impedance curve (pressure drop curve) is computed by CFD in substitute for experiment. In reverse order to the experimental principle of the fan tester, pressure difference was adopted first as inlet and outlet boundary conditions of the system and then flow rate was calculated.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.440_441
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• 2009

The standard for the frequency protection of distributed generation in Korea Electric Power Corporation (KEPCO)'s standard doesn't include the setting of frequency protection. Therefore, this paper analyzes the correlation between the frequency protection requirements and the stability of grid-connected PV system for the adjustable operating setting of frequency protection. The distribution system interconnected with 3 MW PV system is modeled by Matlab/Simulink. The various value of frequency is simulated. For studied cases, the stability of PV system is analyzed. It is concluded that the operating setting of frequency protection can be determined by the stability of PV system.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.8 no.1
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• pp.25-32
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• 2012

Korea Hydro & Nuclear Power Co. (KHNP) has developed and implemented the maintenance effectiveness monitoring (MR) programs for the operating nuclear power plants. The MR program is developed by reflecting design characteristics of the operating nuclear power plants to monitor the plant performance for improving the safety and reliability. Recently, KHNP has built a new nuclear power plant, and developed the MR program to establish the advanced maintenance system by reflecting unique design characteristics based on the OPR1000 standard model. So, the MR program developed in this study has another characteristics in comparison with the OPR1000 standard model, and we will verify the suitability of the MR program through evaluating initial performance of the plant. The safety and reliability of the new plant will be improved by developing and implementing the MR program.

• Journal of architectural history
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• v.6 no.2 s.12
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• pp.65-77
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• 1997

The Hwasong City Wall was built for three years(1794-1796), but the real construction term was taken only 28 months. The wall and the buildings on the wall were built simultaneously, and the esttimated construction cost was highly restricted. These conditions were main factors for considering the high efficiency of construction productivity. This study examines these factors that are reflected in the operating system of the architectural standard scale of length, the architectural composition system in the Hwasong City Wall to reduce the construction cost. Through the study, following factors are found. 1.The rule of multiple proportion is found in the relationship between the partition distance, that is, span and the height of the girder which is related to the productivity of ready-made building members. 2.The ruling grade system of scale in the component members is found in the chang-bang(창방, penetration members)

• Journal of IKEEE
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• v.23 no.1
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• pp.214-223
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• 2019

This paper presents methodologies and strategies for developing standard operating procedures (SOPs) that are essential for practical use of disaster communication systems. Therefore, the various factors related to the SOP of the public safety network(SafeNet) are identified and analyzed, and the processes and strategies for the effective development of the SOP are developed and presented based on the analysis. In addition, the proposed SOP is reflected in LTE, which is public safety network implementation technology, and suggests how priority and QoS that are the basis of radio resource allocation should be operated.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.13 no.1
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• pp.48-63
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• 1984

Standard Building Operation Conditions(SBOC) is to describe typical conditions under which a building would operate during the coulee of a day In order to develop SBOC profiles for office building, we surveyed the operating conditions of randomly selected 20 existing office buildings in Seoul by means of enquetes, and made SBOC profiles. SBOC profiles consist of human occupancy profile, light ins usage profile, system schedule and domestic hot water profile etc. SBOC profiles will be used as input data of DOE-2 computer program to estimate DER(Design Energy Requirements) and to develop EBL (Energy Budget Level), SBOC profiles are not meant to be exact description of how a building will actually be used by its respective users. Rather they are intended to be reasonable typical project ions of how buildings might be used.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.35-40
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• 2009

Electrically operated hospital bed and operating table are useful devices to care patients and to keep postures of them in medical treatment. However they have the risk of physical injury due to various functions and mechanisms consisting of them. In this paper we propose particular requirements for the safety and test methods of electrically operated hospital beds and operating table classified into medical devices. Each items are developed based on international standards. The results of this study can be used for developing internationally harmonized standards for the approval of Korea Food and Drug Administration (KFDA).

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.668-671
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• 2001

For the saving of energy consumption, it is necessary that the high efficient energy transfer machine. We found the optimum operating condition of screw water chiller during this performance test. The specifications of compressor for this performance test are as follows. Built-in volume ratio; Vi=2.4, using refrigerant; HCFC-22, nominal motor output; 60kW(80Hp). We found the test results on water cooled chiller standard test condition that the evaporating capacity is increased 8% maximum and 5.6% under same operating condition. and COP is increased 11 % max. and 8% under same operating condition with change of the evaporating inlet/outlet condition. For the results of these test, we can estimate the optimum operating condition of water cooled type screw chiller.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.3
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• pp.117-121
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• 2021

The Multi-crew Pilot License (MPL) is a new pilot qualification introduced by ICAO to train co-pilots for transport aircraft based on efficient and stable competency to respond to changes in the operating environment and technology. ICAO and the European Union Aviation Safety Agency (EASA) require a minimum flight of 240 hours for MPL qualification training, and allow the use of flight simulation training devices (FSTDs) for most of the training, specifying the performance requirements for FSTDs. As South Korea is also preparing for the operation of the MPL training program, it is essential to establish the operating standards for FSTDs required for MPL training. This study aims to identify the international standards for FSTDs related to MPL training, and to compare them with the current operating standards for FSTDs in South Korea for presenting a standard (draft) that can be used when introducing domestic MPL training programs in the future.

• ETRI Journal
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• v.37 no.6
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• pp.1120-1128
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• 2015

We propose a pseudo optical N-level pulse-amplitude modulation (PO PAM-N) signal using a few externally-modulated lasers (EMLs) operating at different wavelengths, which is suitable for upgrading the transmission speed over an optical link of < 10 km single-mode fiber with low-cost components. To compare a PO PAM-N signal with that of a standard optical PAM-N signal, we perform experiments for evaluating the performance of a 51.56-Gb/s PO PAM-4 signal and standard 51.56-Gb/s optical PAM-4 signal. The receiver sensitivity (at $BER=10^{-5}$) of the PO PAM-4 signal is 1.5 dB better than the receiver sensitivity of a standard optical PAM-4 signal. We also investigate the feasibility of PO PAM-N (N = 4, 8, and 16) signals operating at 103.12 Gb/s, considering relative intensity noise, timing jitter, extinction ratio (ER) of EMLs, and dispersion. From the results, a PO PAM-8 signal performs better than PO PAM-4 and PO PAM-16 signals at 103.12 Gb/s. Finally, we suggest a timing control method to suppress the effect of dispersion in a PO PAM-N signal. We show that the tolerance to dispersion of a 103.12-Gb/s PO PAM-8 signal can be improved to ${\pm}40ps/nm$ by applying a proposed scheme.