• 신재생에너지
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• 제3권2호
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• pp.11-16
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• 2007

This paper analyses the environmental effect of 100kw PV system installed in Tibet using Life Cycle Assessment(LCA). Then, energy payback time(EPT) and life-cycle CO2 emission rate are estimated based on life-cycle of the PV system. As a result of the estimation, 6 year of EPT and 20 g-C/kWh of CO2 emission rate are obtained. In China, average CO2 emission rate of fossil fuel power generation plant is 260 g-C/kWh. This shows that PV system would be very promising for global environmental issues. For advanced LCA, we need to collect detailed and various data about raw material of PV system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.277-281
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• 2008

This paper presents the development of a high efficiency transport refrigeration system for sliced-raw fish transportation. The refrigeration system is equipped with heat storage for reverse cycle-hot gas defrost (the stored heat is used during defrost cycle of the system). System performance and container operating conditions are analyzed during experimental investigation on a $3,225{\times}1,740{\times}1,640\;mm$ full-scale refrigerated container under cooling and defrosting conditions. The prototype system indicates better performance in terms of shorter cooling-down time, shorter defrost time and smaller fluctuations of refrigerated container's temperature.

• 한국기계연구소 소보
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• 통권19호
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• pp.117-123
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• 1989

This study is to develop interactive program for work-cell layout of SACARA type robot by using PC. To make this program interactively, we made use of the software which has the function of menu, dialog box, and graphic. By using the mouse, we can progress this program quickly and easily. It has 2Y2 dimension and provides that one can layout elements (robot, peripheral device, and etc.), create work path, and calculate cycle time of working robot. By comparing with cycle times of any number of work-cell layout for same work, we can evaluate work-cell layout. Finally, we can select one work-cell layout to be considered optimal one which has the least cycle time.

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.39-43
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• 2008

Productivity is one of the performance indices of the semiconductor equipment in manufacturing viewpoint. Among many ways tried and adopted for improvement of the productivity of the FAB equipment, variation of equipment configuration was considered and its effect on the throughput was analyzed. Parallel machine cycle charts that were generated based on the equipment log were used in the analysis. Efficiency of the equipment due to change of the structure and the probability of the usage in the manufacturing process were examined. The results showed that the modification of the control algorithm in the equipment and the redistribution of the process time for each process and transfer module along to the change in the structure enhance the throughput of the equipment.

• Journal of Electrochemical Science and Technology
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• 제15권3호
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• pp.414-420
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• 2024

Lithium-ion batteries are widely used in many applications due to their high energy density, high efficiency, and excellent cycle ability. Once an unknown Li-ion battery is reusable, it is important to measure its lifetime and state of health. The most favorable measurement method is the cycle test, which is accurate but time- and capacity-consuming. In this study, instead of a cycle test, we present an empirical model based on the C-rate test to understand the state of health of the battery in a short time. As a result, we show that the partially accelerated charge/discharge condition of the Li-ion battery is highly effective for the degradation of battery capacity, even when half of the charge/discharge conditions are the same. This observation provides a measurable method for predicting battery reuse and future capacity degradation.

• 한국항행학회논문지
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• 제10권2호
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• pp.145-151
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• 2006

본 논문에서는 동적인 환경에서 돌발 장애물을 회피하는 방법으로 Nearness Diagram, Limit-Cycle 및 벡터장법을 혼합한 새로운 항법을 제안한다. Limit-Cycle 항법은 정면장애물을 회피 하는데 사용되고, 벡터장법은 측면장애물을 회피 하는데 이용된다. 그리고 Nearness Diagram 항법은 로봇의 근접지역장애물을 회피하는데 사용된다. 제안된 항법은 시뮬레이션을 통해 그 성능을 증명하였다.

• 대한한의학회지
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• 제34권1호
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• pp.136-145
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• 2013

Objectives: Recently, Korean medicine has been explored by employing mathematical methods, which is an effort to raise Korean medicine to a higher level of scientific research. In that vein, we propose a mathematical model, analyzing the effects of seasonal cycle as an external factor in addition to the internal interactions of five-states, the engendering and the restraining. Methods: Some modified differential equations with 5-state variables were given to describe the interactions of the engendering and the restraining, and effect of seasonal cycle, and are numerically analyzed by Runge-Kutta method. We then simulated it along with time and dynamically analyzed it by Moran's I, a spatial autocorrelation. Results: We showed the effects of seasonal cycle on yin-yang five-states and applied it to the human life cycle. Conclusions: Our result is comparable to previous results in the respect that we consider the seasonal cycle and its effect on five-states, unlike others' mainly focusing on internal interaction. Furthermore, we suggest some follow-up study taking into consideration the complexity and diversity of external factors.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.23-30
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• 2011

International cooperation to reduce greenhouse gas emissions is expected to provide a big crisis and a great opportunity at the same time for our industry that heavily consumes energy. To cope actively with the international environmental regulation, such as the Framework Convention on Climate Change, quantitative measurement of the volume of greenhouse gases emitted by various industries and quantitative prediction of the greenhouse gas emissions of the future are becoming more important than anything else at the national level. This study aims to propose the calculation process of carbon dioxide($CO_2$) emission for building in life cycle. This paper describes and compares 9 different tool for environmental load estimation with LCA. This study proposed the calculation process for quantitatively predicting and assessing $CO_2$ emissions during the life cycle of buildings based on the life cycle assessment(LCA). The life cycle steps of buildings were divided into the design/supervision, new construction, repair, renovation, use of operating energy in buildings, maintenance, and reconstruction stage in the life cycle inventory analysis and the method of assessing the environmental load in each stage was proposed.

• 천문학논총
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• 제14권2호
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• pp.91-102
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• 1999

We have made intensive calculations on the maximum relative sunspot number and the date of solar maximum of 23rd solar cycle, by using the statistical and precursor methods to predict solar activity cycle. According to our results of solar data processing by statistical method, solar maximum comes at between February and July of 2000 year and at that time, the smoothed sunspot number will reach to $114.3\~122.8$. while precursor method gives rather dispersed value of $118\~17$ maximum sunspot number. It is found that prediction by statistical method using smoothed relative sunspot number is more accurate than by any method to use any data of 10.7cm radio fluxes and geomagnetic aa, Ap indexes, from the full analysis of solar cycle pattern of these data. In fact, current ascending pattern of 23rd solar cycle supports positively our predicted values. Predicted results by precursor method for $Ap_{avg},\;aa_{31-36}$ indexes show similar values to those by statistical method. Therefore, these indexes can be used as new precursors for the prediction of 23rd or next solar cycle.

• 한국건축시공학회지
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• 제9권6호
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• pp.105-111
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• 2009

건설기계는 건설사업의 성공적인 수행의 중요한 요인이며, 건설기계에 소요되는 비용이 건설공사비에서 차지하는 비중은 점차 증가하고 있다. 우리나라는 표준품셈에 제시된 건설기계 시공능력 산정식을 이용하여 건설기계의 시간당 작업량을 계산하고 있다. 건설기계 성능은 개선되고 있으나 시공능력 산정식에서 활용되고 있는 요소들은 이를 반영하지 못하고 있는 실정이며 극히 부분적으로만 재 개정되었다. 본 연구에서는 건설기계 시공능력 산정식 요소 중 사이클타임에 대해서 조사하였다. 이를 위해 먼저 관련 선행연구를 분석하였고, 건설공사에 주로 사용되는 건설기계인 굴삭기와 로우더의 사이클타임을 실사하였다. 수집된 자료와 현행 표준품셈의 시공능력 산정식에 적용되는 수치를 바탕으로 시뮬레이션 프로그램인 크리스탈볼을 활용하여 건설기계의 시공능력을 산정하였다.