• 한국포장학회지
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• 제15권1호
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• pp.7-16
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• 2009

The purpose of this study was to evaluate current packaging modules and design the most acceptable packaging module for domestic and international distribution systems. An optimum packaging module can reduce package costs as well as total distribution costs such as transport, materials handling and warehouse costs. Three different sizes of packaging modules, namely U-type($600{\times}500\;mm$), K -ype($550{\times}366\;mm$) and I-type($600{\times}400\;mm$), were evaluated in terms of the area efficiency and MOEs(measures of effectiveness) for the T-11($1100{\times}1100mm$) and T-12($1,200{\times}1,000\;mm$) pallets. The results showed that the U-type module could fit very well for both pallets and the area efficiency of each module was more than 99 percents. Area efficiency of K-and I-type modules was greatly affected by the pallet footprint dimensions. U-type module also performed better result from MOEs evaluation. Twenty sub-multiple sizes derived from the U-type module were suggested for the future development of the Korean and ISO standards on dimension of transport packages.

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권3호
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• pp.266-269
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• 2012

High-efficiency built-in redundancy analysis (BIRA) is presented. The proposed BIRA uses three techniques to achieve a high repair rate using spare mapping registers with adjustable fault tags to reduce area overhead. Simulation results show that the proposed BIRA is a reasonable solution for embedded memories.

• 동력기계공학회지
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• 제10권1호
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• pp.12-18
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• 2006

A three-degree of freedom model of intake system was contrived and investigated in various ways for the purpose of the amelioration of the volumetric efficiency in a low and transient engine speed for a multi cylinder diesel engine. The basic concept beyond this model started from the theory that each degree of freedom model has volumetric efficiency peak as many as its number of the degree of freedom. The volumetric efficiency affects significantly to the engine performance; torque characteristics, fuel economy and emission level. For commercial vehicles and stationary engines, the engine is designed so as to produce their best performance near the normal engine speeds, thus the low engine speed area has a tendency of poor volumetric efficiency. The aim of this study was highlighted on the amelioration of volumetric efficiency of low engine speed area in a multi cylinder diesel engine matched with an additional Helmholtz resonator. By the use of VIS(variable induction system) volumetric efficiency at low engine speed range was significantly improved. The availability of control by combination of VIS and CIS(conventional induction system) will be proposed as a variable induction system that would be an appropriate model for amelioration of the volumetric efficiency at low engine speed.

• 한국환경과학회지
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• 제11권1호
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• pp.69-74
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• 2002

This study was performed to evaluate an applicability of the SMMCMAS system for reuse of the sewage from spa area and was operated to HLR(Hydraulic loading rate) of 211.3 to 126.8 $\ell$/㎥/d. The operating HRT(Hydraulic retention time) ranges were 2.5 to 1.5 hours. Conclusions are as follows; At the optimum HLR of 158.5 $\ell/\m^2$/d (HRT of 2.0 hours), the maximum BOD removal efficiency was 94% and the effluent BOD concentration was 1.1mg/$\ell$ in result. As the HLR was increased to 211.3 $\ell/\m^2$/d, BOD removal efficiency was decreased to 75% and BOD removal efficiency was also reduced to 74% at lower HLR of 126.8 $\ell/\m^2$/d. It shows that the maximum BOD removal efficiency occurs at an optimum HLR value and that the removal efficiency decreases when the HLR is either higher or lower than the optimum value. Sludge production rates were ranged 0.01 to 0.24gVSS/gBODrem/d and accomplished to 0.01gVSS/gBODrem/d at the optimum HLR of 158.5 $\ell/\m^2$/d.

• 한국컴퓨터정보학회논문지
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• 제18권9호
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• pp.1-10
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• 2013

본 논문에서는 대표적인 특징점 추출 알고리즘인 SIFT(Scale-Invariant Feature Transform)를 매니코어 프로세서를 이용하여 병렬 구현하고, 이를 실행 시간, 시스템 이용률, 에너지 효율 및 시스템 면적 효율 측면에서 분석하였다. 또한 기존의 고성능 CPU와 GPU(Graphics Processing Unit)와의 성능 비교를 통해 제안하는 매니코어의 잠재가능성을 입증하였다. 모의실험 결과, 매니코어를 이용한 SIFT 알고리즘 구현 결과는 기존의 OpenCV 구현 결과와 정확도면에서 동일하였고, 매니코어 구현은 고성능 CPU 및 GPU 구현보다 실행시간 측면에서 우수하였다. 또한 본 논문에서는 SIFT알고리즘의 옥타브 크기에 따른 에너지 효율 및 시스템 면적 효율을 분석하여 최적의 모델을 제시하였다.

• 대한인간공학회지
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• 제35권6호
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• pp.569-580
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• 2016

Objective: This study aims to identify the most effective keyboard layout in the area of performance for securing usability in a smart watch-using environment and to verify the usability of touch keyboard calibrated by hand. Background: It is necessary to understand the environmental characteristics in using the smart watch and to secure the usability of touch keyboard based on this understanding in order to take account of the users who use the touch screen in the extreme input conditions caused by the small screen of a smart watch. Method: 30 participants in this study were required to input characters using the QWERTY keyboard and 3x4 keypad (Naratgul, Chunjiin), which were familiar with them, in order to grasp the keyboard layout suitable in the smart watch- using environment; the performance (error rate, performance time) of this case was measured. In addition, 30 participants in this study were required to input the characters setting the QWERTY keyboard with calibrated touch area and the one with uncalibrated touch area, based on the characteristics of touch behavior, by finger typing the keyboard, with the performance (error rate and performance time) of this case measured. Results: QWERTY keyboard (93.3sec) is found to be 31.2% faster than Naratgul keyboard, a kind of 3x4 keypad, and 43.6% faster than Chunjiin keyboard, in the area of efficiency, in the results of the usability evaluation regarding the keyboard layout. QWERTY keyboard with calibrated touch area (7.5%) is found to be 23.5% improved compared to the QWERTY keyboard with uncalibrated touch area (9.8%) in the area of accuracy (error rate). The results of the usability evaluation regarding the QWERTY keyboard with touch area calibrated by finger typing the keyboard and QWERTY keyboard with calibrated touch area (80.7sec) is found to be 5.7% improved compared to QWERTY keyboard with uncalibrated touch area (85.6sec) in the area of efficiency (performance time). Conclusion: QWERTY keyboard is found to have an effective layout in the area of efficiency in the smart watch-using environment, and its improved usability is verified in the areas of accuracy and efficiency in the QWERTY keyboard with a touch area calibrated by finger typing the keyboard. Application: The results of this study may be used to set up the basic touch keyboard of the smart watch. The input usability is expected to secure the smart watch-using environment, which is an extreme input condition by applying QWERTY keyboard with touch area calibrated by finger typing the keyboard.

• ETRI Journal
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• 제39권6호
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• pp.859-865
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• 2017

This paper presents a method for determining the optimum active-area width (OAW) of solar cells in a module architecture. The current density-voltage curve of a reference cell with a narrow active-area width is used to reproduce the current density profile in the test cell whose active area width is to be optimized. We obtained self-consistent current density and electric potential profiles from iterative calculations of both properties, considering the distributed resistance of the contact layers. Further, we determined the OAW that yields the maximum efficiency by calculating efficiency as a function of the active-area width. The proposed method can be applied to the design of the active area of a dye-sensitized solar cell in Z-type series connection modules for indoor and building-integrated photovoltaic systems. Our calculations predicted that OAW increases as the sheet resistances of the contact layers and the intensity of light decrease.

• 복식문화연구
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• 제6권4호
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• pp.229-237
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• 1998

The ventilation efficiency of clothing was investigated by a trace gas method using a manikin wearing an impermeable overall under an isothermal condition, where the ventilation occurred only through the openings by diffusion. The ventilation patterns were different for each part of the body. The ventilation efficiency in the clothing microenvironment of the arm and the leg greatly depended on the distance from each opening when the wrist- or the ankle-opening was opened. When both side of wrist- or ankle-openings were opened to provide the opening area double respectively, the ventilation efficiency did not correspondingly increase twice, as compared one side opened. Even though it as certainly affected by the opening area, the ventilation efficiency was more significantly influenced by the position of openings.

• 한국수산과학회지
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• 제28권6호
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• pp.720-727
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• 1995

A Monte Carlo computer simulation study was conducted to determine the most efficient sampling design for the blue crab dredge capture efficiency experiment performed in Chesapeake Bay, Maryland, U. S. A. The input values were the number of dredge tracks in each experimental area, the number of tows per experiment, the number of experiments, the mean density of crabs per unit area, the negative binomial coefficient, the gear capture efficiency, and the tow error. As a result of the study, a four-track experiment with twenty to twenty-eight tows was estimated to be the best in terms of precision and accuracy of the gear capture efficiency.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.53-60
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• 2005

The purpose of this study is to improve energy efficiency of windows in office buildings through the evaluation of their heating, cooling and illumination load. Energy efficiency is influenced by window size which is determined at the early stage of building design. The process of this study is as follows. First, energy performance is analysed according to the various rates of windows through computer simulation (ECOTECT). Then, the annual heating, cooling and illuminating loads according to the different window sizes are compared one another. Results indicated that the optimal window size considering energy efficiency is 50% of the surface area. When the window size is 50% of the surface area, annual maintenance expense is also smallest. Since the cost of cooling is larger than that of heating, too low indoor air temperature in summer is unfavorable based on the reasonable annual maintenance expenses.