• 산업경영시스템학회지
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• 제47권2호
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• pp.57-64
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• 2024

The use of big data needs to be emphasized in policy formulation by public officials in order to improve the transparency of government policies and increase efficiency and reliability of government policies. 'Hye-Ahn', a government-wide big data platform was built with this goal, and the subscribers of 'Hye-Ahn' has grown significantly from 2,000 at the end of 2016 to 100,000 at August 2018. Additionally, the central and local governments are expanding their big data related budgets. In this study, we derived the costs and benefits of 'Hye-Ahn' and used them to conduct an economic feasibility analysis. As a result, even if only some quantitative benefits are considered without qualitative benefits, the net present value, the benefit/cost, and internal rate of return turned out to be 22,662 million won, 2.3213, and 41.8%, respectively. Since this is larger than the respective comparison criteria of 0 won, 1.0, and 5.0%, it can be seen that 'Hye-Ahn' has had economic feasibility. As noticed earlier, the number of analysis using 'Hye-Ahn' is increasing, so it is expected that the benefits will increase as time passes. Finally, the socioeconomic value gained when the results of analysis using 'Hye-Ahn' are used in policy is expected to be significant.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.1932-1950
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• 2018

The paper proposes a code-clone detection method that gives the highest possible precision and recall, without giving much attention to efficiency and scalability. The goal is to automatically create a reliable reference corpus that can be used as a basis for evaluating the precision and recall of clone detection tools. The algorithm takes an abstract-syntax-tree representation of source code and thoroughly examines every possible pair of all duplicate tree patterns in the tree, while avoiding unnecessary and duplicated comparisons wherever possible. The largest possible duplicate patterns are then collected in the set of pattern clusters that are used to identify code clones. The method is implemented and evaluated for a standard set of open-source Java applications. The experimental result shows very high precision and recall. False-negative clones missed by our method are all non-contiguous clones. Finally, the concept of neighbor patterns, which can be used to improve recall by detecting non-contiguous clones and intertwined clones, is proposed.

• 전기전자학회논문지
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• 제23권2호
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• pp.524-528
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• 2019

다양한 종류의 방전 셀이 존재하고 있지만, 공통적으로 모든 방전 셀은 보다 낮은 구동 전압에서 보다 높은 효율 특성을 가지는 것을 우선적인 목표로 한다. 이러한 특성 개선을 위해 방전셀 내부의 방전 경로를 길게 하거나 구동 가스의 성분을 변화시키는 연구가 많이 이루어진다. 본 논문에서는 2차원 유체 시뮬레이션을 이용하여 방전전극 사이의 간격에 따른 방전전압 (개시전압 및 유지전압) 및 휘도와 효율의 변화를 계산하였다. 또한, 다양한 하전입자와 여기입자 및 파장별 진공자외선의 변화를 살펴보고 휘도와 효율의 원인을 연구해 보았다.

• 가정과삶의질연구
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• 제31권1호
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• pp.85-98
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• 2013

The goal of this study is to evaluate the effectiveness of a program which can improve the marital satisfaction of newlywed couples. The program was practiced once a week for 4 weeks at K healthy family center and each session lasted for 100 minutes. The participants of the program were 5 newlywed couples who desired to increase their relationship and marital satisfaction. In order to investigate the effectiveness of the program, we used the Wilcoxen signed rank test. The results of the analyses, showed that there were significant differences of increases in the areas of the newlywed couples' marital satisfaction, communication efficiency, conflict coping strategies, and self-esteem. In conclusion, the effectiveness and utilization of the program were confirmed. Also, it was verified that the program can be an important tool for strengthening healthy family functioning through a study on newlywed couples in the field of community-based family work practice.

• Tribology and Lubricants
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• 제25권4호
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• pp.243-249
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• 2009

A magnetic clutch consists of pulley and disk. It delivers and isolates the power needed for the operation of the compressor used in automotive air conditioning system. To improve the performance, efficiency and durability of automotive air conditioning system, appropriate design of pulley, disk and system working parameters(the magnitude of magnetic force, and so on) is necessary. For that goal, it is required to understand the friction characteristics of magnetic clutch for the initial operating time. In this study, friction tests were carried out in order to investigate the effect of sliding velocity on the friction characteristics of magnetic clutch using pin-on-disk type friction and wear tester. For experiments, pulley and disk used in real automotive air conditioning system were considered. Friction experiments were conducted under various sliding velocities, and coefficients of kinetic friction were obtained. Under the experimental conditions considered in this study, the coefficients of kinetic friction increased with the increase of test number(sliding distance) and decreased with the increase of sliding velocity.

• 대한지역사회영양학회지
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• 제9권2호
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• pp.225-232
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• 2004

The objective of this study is to investigate how patients satisfaction are affected by satisfaction with the patient menu and differentiated service resulting from QI activities and to evaluate the efficiency of QI activities. In order to improve satisfaction with menus through QI activities, this study strengthened meal round, examined the quantity of food waste produced by patients, diversified one-dish menus and used seasonal food as much as possible to reflect patients ′tastes to the maximum. With regard to cooking, additionally, it strengthened sampling and standardized recipes to maintain the constancy of taste and cooking/seasoning. From July 2003, dining time was changed from 08 : 00 to 07 : 30 for breakfast and from 17 : 30 to 18 : 00 for dinner. Statistical data analyses were completed using the SPSS 11.0 program. The results can be summarized as follows: The goal of QI was to improve food service by raising the score of "Satisfaction with Offered Menus" from 3.49 before QI to 3.55 after QI and differentiating nutrition service at the VIP ward. The score of "Satisfaction with offered menus" after QI was 3.56, and services related to the VIP ward were 7 dishes per meal, meal round once per day and the use of a napkin for a spoon in setting the table. In addition a variety of dishes were used in order to heighten the visual effect. Among the 10 items included on the patient satisfaction questionnaire, 8 items showed higher scores before QI. "Taste of meals" (p ＜ 0.05), "Satisfaction with offered menus" (p ＜ 0.05), "Kindness of meal serving assistants" (p ＜ 0.05) and "Cleanliness of clothes ＆ features" (p ＜0.05) of VIP ward were significantly higher than those of a general ward.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.845-855
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• 2022

In response to climate change, the world is continuing efforts to reduce fossil fuels, expand renewable energy, and improve energy efficiency with the goal of achieving carbon neutrality. In particular, R&D is being made on the value chain covering the entire cycle of hydrogen production, storage, transportation, and utilization in order to shift the energy supply system to focus on hydrogen energy. Hydrogen-based energy sources can produce heat and electricity at the same time, so it is possible to utilize heat energy, which can increase overall efficiency. In this study, calculation of the optimal scale for hydrogen-based cogeneration and the composition of heat sources were reviewed. It refers to a method of the optimal heat source size according to the external heat supply and heat storage to be considered. The results of this study can be used as basic data for establishing a hydrogen-based energy supply model in the future.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.301-301
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• 2009

The General program evaluation guide is intended for use by managers of both deployment and R&D programs within the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), although most of the examples of evaluations pertain to deployment programs(EERE,2006). It could help managers determine what kinds of timely adjustments may be needed in program design or implementation to improve the rate or quality of achievement relative to the committed resources. To consider the adaptation of the method in Korea, we have studied the evaluation case for solar america initiative using cost-benefit evaluation. The President's Solar America Initiative (SAI) was launched in January 2006 as part of the administration's Advanced Energy Initiative. The SAI has a goal of installing 5-10 GW of photovoltaic (PV) systems in the U.S. by 2015 and 70-100 GW of PV systems in the U.S. by 2030. The evaluation report presents estimates of the potential benefits should the SAI PV installation goals be achieved. For this analysis, the areas researched include energy, economic, and environmental benefits. As a result, research suggests that 500 MW of PV may have been enough to avoid lackout. The ability of PV to prevent specific blackouts will depend on very specific information on where the PV installations are installed and their ability to relieve pressure on the high stress points on the grid. While this level of detail is outside the scope of this study, it appears that there will be some potential benefit for blackout prevention should the SAI PV goals be achieved.

• Membrane and Water Treatment
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• 제6권3호
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• pp.173-187
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• 2015

The goal of present work is the preparation of a novel positively charged nanofiltration (NF) membrane and its development for the cation removal of aqueous solutions. This NF membrane was fabricated by the surface modification of polysulfone (PSf) ultrafiltration support. The active top-layer was formed by interfacial cross-linking polymerization of poly(ethyleneimine) (PEI) with p-xylylene dichloride (XDC) and then quaternized with methyl iodide to form a perpetually positively charged layer. In order to improve the efficiency of nanofiltration membrane, the concentration of PEI, XDC and methyl iodide solutions, PEI coating and cross-linking time have been optimized. As a result, a high water flux and high $CaCl_2$ rejection (1,000 ppm) was obtained for the composite membrane with values of $18.29L/m^2.h$ and 93.62% at 4 bar and $25^{\circ}C$, respectively. The rejections of NF membrane for different salt solutions followed the order of $Na_2SO_4$ < $MgSO_4$ < NaCl < $CaCl_2$. Molecular weight of cut off (MWCO) was calculated via retaining of PEG solutions with different molecular weights that finally, it revealed the Stokes and hydrodynamic radius of 1.457 and 2.507 nm on the membrane selective layer, respectively. The most efficient positively charged nanofiltration membrane exhibited a $Ni^{2+}$ rejection of 96.26% for industrial wastewater from Shamse Hadaf Co. (Kashan, Iran).

• 한국정보과학회논문지:정보통신
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• 제35권6호
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• pp.549-556
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• 2008

멀티미디어 통신에서 융통성 있는 비주얼 콘텐츠를 제공하기 위해 ISO/IEC MPEG & ITU-T VCEG의 JVT는 H.264/AVC 표준에 기반을 둔 확장 형식으로 SVC를 표준화하였다. JVT는 H.264/AVC SVC의 압축 효율을 높이기 위해 기존 H.264/AVC에서 제공하는 인터 예측(inter prediction) 과 인트라 예측(intra prediction) 뿐만 아니라 계층 간의 중복요소을 제거하는 계층 간 예측을 추가로 수행한다. 계층 간 예측 방법은 기본계층에서 코딩된 데이타를 재사용하여 향상계층의 비트율-왜곡(rate-distortion) 효율을 향상시킨다. 그러나 계층 간 예측을 추가로 수행함으로써 계산 복잡도가 높아지는 문제점이 있다. 본 논문에서는 이러한 계산 복잡도를 감소시키기 위해 계층 간 예측 중 기본계층의 잔여 신호값을 이용하는 예측 과정에서 효율적인 잔여신호 업 샘플링의 기법을 제안한다. 실험 결과 코딩 효율을 유지하면서 예측과정의 계산복잡도를 약 30% 줄일 수 있었다.