• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.217-222
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• 2005

Building energy consumption according to the ventilation has been considered to be an important subject. The purpose of this study is to investigate the cooling loads in a test space with a forced ventilating system. In the test space, on/off controlled air-conditioning and forced ventilating facility were operated between 8:30 to 21:00 during 4 days and some important data like temperatures and energy consumption were measured to obtain actual cooling loads. The simulation was carried out in a mode of temperature level control using a TRNSYS 15.3 with a precisely measured air change amount and performance data of air-conditioner. Cooling loads including sensible and latent were compared between by experiment and by simulation. Both of cooling loads associated with ventilation show a close agreement within an engineering tolerance.

• 전기학회논문지
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• 제57권8호
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• pp.1470-1477
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• 2008

In this paper, a new detection method of series arc-fault signals occurring at the wiring of home appliances is proposed. The discrete wavelet transform was used for the numerical analysis of the variation rate in peak, RMS, noise energy, shoulder of the arc-fault current wave. As a results, the arc distinction threshold value of these variation rates was about 0.1 in most cases. The arc-fault current of the loads with the active PFC circuit showed a high rate of variation in noise energy and shoulder, but arc-fault current of the loads without the active PFC circuit showed a high rate of variation in peak and RMS. The arc fault current in resistive loads showed a high rate of variation in shoulder.

• 한국태양에너지학회 논문집
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• 제29권5호
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• pp.1-7
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• 2009

Energy demands for offices in Korea are surveyed and analyzed to generate communicational models for simulations. Daily energy loads of 13 office buildings scattered in the 6 largest cities in the country are surveyed and analyzed based on energy consumption log sheets. Detailed hourly loads that are frequently required when a detailed operation simulation is performed are measured using remote data acquisition processes for 3 offices. The complete load demand models of electricity, cooling, heating and hot water are established by combining the daily and hourly patterns based on the statistical behavior of the hourly patterns.

• 설비공학논문집
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• 제21권11호
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• pp.636-642
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• 2009

Energy consumption data are surveyed and measured to develop energy demand models for hospital buildings as part of a complete package. Daily consumption profiles for electricity, heating, cooling and hot water are surveyed for 14 carefully chosen hospitals to establish energy demand patterns for a time span of a year. Then the hourly demand patterns of the 4 loads are field-measured for different seasons and statistically analyzed to provide higher resolution models. Used in conjunction with energy demand models for other types of buildings, the high resolution of 8760 hour energy demand models for a hospital for a typical year will serve as building blocks for the comprehensive model that allows the estimation of the combined loads for arbitrary mixtures of buildings.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.34-40
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• 2011

Apartment Housing has been increasing steadily, particularly our current super high-rise apartment houses that represent the culture has become a trend in Korea. These super high-rise apartment houses' curtain wall system increases heating and cooling loads, it is expected to vary by each unit's thermal properties. In this study, measured indoor environment and energy simulation results were compared to actual energy consumption. As a result, the various factors that affect heating and cooling loads, such as direction, plan type and glazing area, influence each unit's load characteristic. In particular, according to the electricity costs savings behavior, the occupant's thermal discomfort is expected to be large in summer. Therefore, to reduce heating and cooling load for each unit requires a reasonable plan.

• 전기학회논문지P
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• 제58권2호
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• pp.101-107
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• 2009

This paper deal with development of on-line type voltage sag compensation system using supercapacitor EDLC to solve the voltage sag problems which are considered to be dominant disturbances affecting the power quality. With the wide use of semiconductor devices in electrical equipment, modem-type loads are becoming increasingly sensitive to the voltage sags and the disturbances prove to be costly to industries. Supercapacitor EDLC is employed to compensate dynamically for the voltage sag of system with sensitive loads. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. Therefore, in this paper, the energy design scheme of supercapacitor and the configuration technique of on-line type voltage sag compensation systems are newly introduced. According to the results of experimental of prototype 5[kVA] system, it is verified that the developed system has effectiveness of voltage sag compensation by using a supercapacitor EDLC.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.135-138
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• 2003

Recently, sandwich structures have been widely employed in load bearing structures due to their high specific stiffness and high specific strength. Some sandwich structures are subjected to not only static loads but also impact loads which might induce failure of structures at far less load than expected. Since sandwich structures can fail in various modes, estimation of the impact energy absorption is difficult. In this work, the impact failure modes and the impact energy absorption characteristics of the sandwich beams were predicted by the FE analysis and confirmed by the impact test. From the analytic and experimental results, the impact failure mode map was constructed with respect to non-dimensional parameters.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 춘계학술대회
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• pp.219-231
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• 2004

The Charpy and Izod impact tests are the most prevalent techniques used to characterize the effects of high impulse loads on polymeric materials. An analysis method for rubber toughened PVC is suggested to evaluated critical dynamic strain energy release rates(G$_c$) from the Charpy impact tester was used to extract ancillary information concerning fracture parameters in additional to total fracture energies and maximum critical loads. The dynamic stress intensity factor KID was computed for varying amounts of rubber contents from the obtain maximum critical loads and also toughening effects were investigated as well. The fracture surfaces produced under low velocity impact for PVC/MBS composites were investigated by SEM. The results show that MBS rubber is very effective reinforcement material for toughening PVC.

• 한국항공운항학회지
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• 제16권1호
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• pp.1-6
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• 2008

Role of landing gear is to absorb energy which is generated by aircraft ground maneuvering and landing. Generally, in order to absorb the impact energy, oleo-pneumatic type shock absorber is used in aircraft landing gear. Oleo-pneumatic type shock absorber has a good energy absorption efficiency and is light in weight because structure of oleo-pneumatic type shock strut is relatively simple. In this study, dynamic load analysis for swinging arm type landing gear was performed to predict landing loads. Modeling of landing gear was conducted with MSC.ADAMS, and dynamic landing loads were analyzed based on ADS-29. Optimum landing loads were generated through adjustment of damping orifice and the analysis results were presented with various aircraft attitude.

• Structural Engineering and Mechanics
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• 제89권2호
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• pp.171-179
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• 2024

The market of the floating solar photovoltaic system is rapidly growing around the world with the rise of renewable energy that can replace fossil energy. While the floating solar photovoltaic system is operating and being installed in several countries, the system is exposed to the risk in terms of structural safety due to the absence of the proper design guideline. In this paper, design loads suitable for the floating solar photovoltaic system are presented. Utilizing the existing reliable design standards such as ASCE 7-16 (ASCE 7-16 2016) and DNV-RP-C205 (DNV-RP-C205 2010), the appropriate design loads for the floating solar photovoltaic system are presented. The proper load combinations are also presented by putting wave load based on DNV standards (DNV-OS-C101 2015 and DNV-OS-C201 2015) into the load combinations in ASCE standards (ASCE 7-16 2016). We present the load combinations for the allowable stress design and load and resistance factor design, respectively.