• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.8
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• pp.722-728
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• 2005

The present paper deals with heating energy estimation in Korean-style apartments, paying special attention to the effect of room condition settings. Two types of heating modes are considered: continuous single-zone and scheduled multi-zone. In the latter, zones during unoccupied periods remain unconditioned. Also analyzed are sensitivities in heating energy with respect to the air change rate and the set temperature. The energy use is estimated with TRNSYS 15, a dynamic load calculation program. Heating energy for the actual residential condition (1.0 ACH and $24^{\circ}C$) appears to be nearly the same as that for a typical design standard (1.5 ACH and $20^{\circ}C$). The air change rate affects heating energy as sensitive]y as the set temperature. For all the simulated cases, the scheduled multi-zone heating mode is more energy-efficient than the continuous single-zone. Heating energy depends appreciably on the shading factor. It is expected that considerable heating energy for apartment houses can be saved by employing a multi-zone mode along with appropriate control devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.6
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• pp.678-680
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• 2016

Due to changes in the energy environment, it's very popular to introduce the solar energy at home. More effective energy management is achieved together with an energy storage system(ESS). The electricity generated by solar can be used effectively to achieve the peak cut and price reduction. In this paper, we developed Smart Energy Profile(SEP) to make an ESS as a component of home energy management system(HEMS) cooperating with home network. First, we defined the functions equipped on the ESS and then developed a standard-based protocol to achieve compatibility between products. Our main contribution is to establish the foundation to introduce the HEMS at home.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3833-3840
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• 2022

A method for calibrating the energy scale and detection efficiency of stilbene scintillators is presented herein. This method can be used to quantitatively analyze the Compton continuum of gamma-ray spectra obtained using such scintillators. First, channel-energy calibration was conducted by fitting a semi-empirical equation for the Compton continuum to the acquired energy spectrum and a new method to evaluate the intrinsic detection efficiency, called intrinsic Compton efficiency, of stilbene scintillators was proposed. The validity of this method was verified by changing experimental conditions such as the number of sources being measured simultaneously and the detector-source distance. According to the energy calibration, the standard error for the estimated Compton edge position was ±1.56 keV. The comparison of the intrinsic Compton efficiencies calculated from the single- and two-source spectra showed that the mean absolute difference and the mean absolute percentage difference are 0.031 %p and 0.557%, respectively, demonstrating reasonable accuracy of this method. The feasibility of the method was confirmed for an energy range of 0.5-1.5 MeV, showing that stilbene scintillators can be used to quantitatively analyze gamma rays in mixed-radiation fields.

• Physical Therapy Korea
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• v.13 no.2
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• pp.35-42
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• 2006

The walker provides stability for walking for people whose lower extremities are disabled. It is important to measure and determine the appropriate height of a walker to conserve energy and to improve function. The purposes of this study were to examine effects of walker height and gait velocity on triceps, latissimus dorsi muscle activation, and energy expenditure index (EEI) during ambulation with a walker. Fifteen healthy subjects participated in this study. Each subject was assigned a walker with one of three heights (high, standard, lower height) and of two gait velocities (comfortable gait velocity or fast gait velocity). Electromyographic data were collected from triceps and latissimus dorsi, and EEI was determined from each condition. Two-way repeated analysis of variance (ANOVA) was used to determine the statistical significance. Post hoc comparison was performed with the Bonferroni test. The results of this study were summarized as follows: 1. There was a significant difference in the %MVIC of triceps among different walker height factors. Post hoc comparison revealed that %MVIC of dominant triceps brachii was more significantly increased in patients who used the higher walker than those who used the lower walker (p<.05). 2. There were significant differences in the %MVIC of the latissimus dorsi among different walker height factors and gait velocity factors. Post hoc comparison revealed that the %MVIC of dominant latissimus dorsi was also more significantly increased in patients who used the higher walker than those who used the lower walker (p<.05) and in those who used the faster gait velocity than those who used the slower gait velocity (p<.05). 3. There were significant differences in the EEI among different walker height factors and gait velocity factors. Post hoc comparison revealed that the EEI was significantly increased among those who used higher and lower walkers compared with the standard walker. The EEI was also more significantly increased among those who used the fast gait velocity than those who used the slower gait velocity (p<.05). It has been concluded that increased muscle activation in triceps and latissimus dorsi was required when the walker height increased and that more energy was exp ended when the gait velocity increased. Therefore, from the findings of this study, it is recommended that walker height be adjusted according to the purposes of gait training and that healthy subjects conserve energy when ambulating with standard walkers in a comfortable gait velocity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1778-1785
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• 2014

In order to construct offshore structures safely, geotechnical investigation should be carried out with high accuracy. Up to now, onshore geotechnical investigation equipments installed on the barge are used for offshore geotechnical investigation. In this case, many limitations can be confronted such as deep water depth, high wave, strong current, severe wind and so on. For the safe and economic offshore geotechnical investigation with high precision, a seabed type unmanned automated site investigation equipment is developed. It can be operated remotely underwater conditions with 100m water depth and can explore the ground depth of 50m. Also, the standard penetration test (SPT), soil boring, soil sampling and rock coring can be possible using the equipment. Numerical analysis was conducted to secure the stability of the equipment against current of 4 knot. Energy efficiency of SPT apparatus which is attached to the equipment shows 78% in average.

• Journal of the Korean Solar Energy Society
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• v.24 no.1
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• pp.1-6
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• 2004

To evaluate performance of concentrating solar cookers, we have designed and constructed parabolic solar cooker. Tests are carried out to define the performance characteristic of concentrating cookers under the ambient conditions. Performance and test of solar cooker were followed the international standard procedure that was proposed at the Third World Conference on solar cooking Stagnation temperature and water heating test are carried out to determine the maximum temperature attained by cooker and evaluate the thermal performance of the cooker, respectively.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.148-157
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• 1997

A new capsule that has a unique structure in which the test environments including neutron flux and fluence, and irradiation temperature can be controlled precisely during irradiation, was conceptually designed. The capsule structure and instrumentation were successfully designed according to the JMTR's standard procedures of capsule design. Based on the target irradiation, the details of the irradiation such as neutron fluence and irradiation temperature ore calculated and the related capsule safety was evaluated. In addition, the effects of design parameters including the changes in inner-capsule configuration, heater capacity, and Helium gas pressure on the specimen temperature were analyzed with a computer program. Through these thermal and strength evaluations, this capsule was proved to be safe during the irradiation in the JMTR.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.3-7
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• 2009

The amount of incident rays over inclination according to direction has been widely utilized as important data in installing solar thermal systems. To optimize the incident solar radiation, the slope, that is the angle between the plane surface in question and the horizontal, and the solar azimuth angles are needed for these solar thermal systems. This is because the performance of the solar thermal systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized solar thermal systems will be provided for designers and employees working in the solar collector related industries.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.1
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• pp.64-70
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• 2008

This paper briefly discusses the main sources of errors and their solutions for measuring hydrogen uptake from gas phase by the Sieverts technique. Correction of volumetric errors of apparatus, density of hydrogen storage material, estimation of temperature gradient are investigated. Systematic errors and the change of density of the host material according to the pressure have been the subject of much controversy in recent years. We considered the standard ball calibration, temperature gradient distribution, pretreatment of hydrogen storage materials to minimize errors. We could lessen the miscalculations after applying those methods to Equilibrium pressure-composition isotherm data.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.12
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• pp.713-715
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• 2005

The work in this paper presents development of fuzzy logic-based energy management strategy for a fuel cell hybrid electric vehicle. In order for the fuel cell system to overcome the inherent limitation such as slow response time and low fuel economy especially at the low power region, the battery system has come to compensate for the fuel cell system. This type of hybrid configuration has many advantages, however, the energy management strategy between power sources is essentially required. For the optimal power distribution between the fuel cell system and the battery system, a fuzzy logic-based energy management strategy is proposed. In order to show the validity and the robustness of suggested strategy, some simulations are performed for the standard drive cycles.