• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.136.2-136.2
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• 2011

In this work, we analyzed correlations between life-cycle greenhouse gas (GHG) emissions and life-cycle cost of energy resources. Energy resources studied in this paper include coal, natural gas, nuclear power, hydropower, geothermal energy, wind power, solar thermal energy, and solar photovoltaic energy, and all of them are used to generate electricity. We calculated the mean values, ranges of maximum minus minimum values, and ranges of 90% confidence interval of life-cycle GHG emissions and life-cycle cost of each energy resource. Based on the values, we plotted them in two dimensional graphs to analyze a relationship and characteristics between GHG emissions and cost. Besides, to analyze the technical maturity, the GHG emissions and the range of minimum and maximum values were compared to each other. For the electric generation, energy resources are largely inverse proportional to the GHG emission and the corresponding cost.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.172-177
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• 2004

Fatigue life prediction is based on fracture mechanics and database which is established from experimental method. Rubber material also uses the same way for fatigue life prediction. But the absence of standardization of rubber material, various way of composition by each rubber company and uncertainty of fracture criterion makes the design of fatigue life by experimental method almost impossible. Tearing energy which has its origin in energy release rate is evaluated as fracture criterion of rubber material and the applicability of fatigue life prediction method are considered. The system of measuring tearing energy using the principal of virtual crack extension method and fatigue life prediction by the minimum number of experiments are proposed.

• Current Photovoltaic Research
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• 제8권1호
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• pp.39-43
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• 2020

In this study, we predict the generation of end-of-life photovoltaic modules when Feed in Tariff applied, in Republic of Korea. Based on the installation of photovoltaic modules, we prepared three different senarios in order to estimate the generation of end-of-life photovoltaic modules. The senarios are i) early worn-out, ii) mid worn-out and iii) late-worn out senario. We selected the mid worn-out senario to estimated the amount of end-of-life photovoltaic modules in this study. Establishment of the end-of-life module generation scenario predicted generation of end-of-life photovoltaic module, and forecasted generation amount of end-of-life module to which Feed in Tariff was applied in consideration of installed photovoltaic modules installed by Feed in Tariff support. The generation of Feed in Tariff-applied end-of-life modules increased from 2021 to 2025 compared to without Feed in Tariff, and since then, the Feed in Tariff-applied end-of-life modules were generated as waste modules during the relevant period (2021 ~ 2025).

• 대한기계학회논문집A
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• 제29권8호
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• pp.1132-1138
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• 2005

Fatigue life of metal material can be predicted by the use of fracture theory and experimental database. Although prediction of fatigue life of rubber material uses the same way as metal, there are many reasons to make it almost impossible. One of the reasons is that there is not currently used fracture criteria for rubber material beacuse of non-standardization, various way of composition process of rubber and so on. Tearing energy is one of the fracture criteria which can be applied to a rubber. Even if tearing energy relaxes the restriction of rubber composition, it is also not currently used because of complication to apply in. Research material about failure process of rubber and tearing energy was reviewed to define the process of fatigue failure and the applicability of tearing energy in estimation of fatigue life for rubber. Also, 1file element formulation of tearing energy which can be used in FE analysis was developed.

• International Journal of Automotive Technology
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• 제7권6호
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• pp.741-747
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• 2006

It has been almost impossible to predict the fatigue life in the field of rubber materials by numerical methods. One of the reasons is that there are no obvious fracture criteria and excessively various ways of mixing processes. Tearing energy is considered as a fracture criterion which can be applied to rubber compounds regardless of different types of fillers, relative to other fracture factors. Fatigue life of rubber materials can be approximately predicted based on the assumption that the latent defect caused by contaminants or voids in the matrix, imperfectly dispersed compounding ingredients, mold lubricants and surface flaws always exists. Numerical expression for the prediction of fatigue life was derived from the rate of rough cut growth region and the formulated tearing energy equation. Endurance test data for dumbbell specimens were compared with the predicted fatigue life for verification. Also, fatigue life of industrial rubber components was predicted.

• 상하수도학회지
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• 제29권1호
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• pp.11-21
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• 2015

When designing Water Distribution System (WDS), determination of life cycle for WDS needs to be preceded. And designer should conduct comprehensive design including maintenance and management strategies based on the determined life cycle. However, there are only a few studies carried out until now, and criteria to determine life cycle of WDS are insufficient. Therefore, methodology to determine life cycle of WDS is introduced in this study by using Life Cycle Energy Analysis (LCEA). LCEA adapts energy as an environmental impact criterion and calculates all required energy through the whole life cycle. The model is build up based on the LCEA methodology and model itself can simulate the aging and breakage of pipes through the target life cycle. In addition the hydraulic analysis program EPANET2.0 is linked to developed model to analyze hydraulic factors. Developed model is applied to two WDSs which are A WDS and B WDS. Model runs for 1yr to maximum 100yr target life cycle for both WDSs to check the energy tendency as well as to determine optimal life cycle. Results show that 40yr and 54yr as optimal life cycle for each WDS, and tendency shows the effective energy is keep changing according to the target life cycle. Introduced methodology is expected to use as an alternative option for determining life cycle of WDS.

• 에너지공학
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• 제22권1호
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• pp.38-43
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• 2013

생활양식의 변화나 생활행위의 변화에 관련한 가정부문 에너지소비 패턴의 분석을 위해서 용도별 에너지소비자료 작성이 절실히 요청되어 왔다. 이에 따라, 생활행위의 분류에 의한 가정부문 용도별 에너지소비 분석모형을 개발하여 에너지소비 분석을 시도하였다. 본고에서는 부위(방)별 에너지 사용기기의 에너지 소비효율에 생활행위별 기기마다 가동시간을 곱해서 가구당 에너지소비량이 산출될 수 있도록 상향식의 가정 내 모형을 구축하였다. 생활행위 분류를 감안한 용도는 조명용, 난방용, 냉방용, 오락용, 정보용, 위생용, 취사용 등으로 구분하였다.

• 동력기계공학회지
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• 제21권1호
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• pp.43-49
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• 2017

This work aims to investigate on the low cycle fatigue life assessment, which is adopted on the strain-life relationship, or better known as the Coffin-Manson relationship, and also the strain energy density-based model. The low cycle fatigue test results of Alloy 617 weldments under $900^{\circ}C$ have been statistically estimated through the Coffin-Manson relationship according to the provided strain profile. In addition, the strain energy density-based model is proposed to represent the energy dissipated per cycle as fatigue damage parameter. Based on the results, Alloy 617 weldments followed the Coffin-Manson relationship and strain energy density-based model well, and they were compatible with the experimental data. The predicted lives based on these two proposed models were examined with the experimental data to select a proper life prediction parameter.

• 대한한의학원전학회지
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• 제26권4호
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• pp.253-266
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• 2013

Objective : There was no attempt to understand Moving Energy between two kidneys(腎間動氣) and Kidney on Left & Life Gate on Right(左腎右命門) by integration progress. So I have faced to study based on two parts with concerning as clues. One is 'Life Right (左 右)' and the other is 'Between(間)'. Methods : Revealing the source of the origin, Nanjingbenyi(難經本義) is given on the basis. Take a close look at publications related to Nanjing(難經) which is about Kidney on Left & Life Gate on Right and Moving Energy between two kidneys. Take a close look at Kidney, the Life Gate and Moving Energy between two kidneys. Look see the three-dimensional uplift movement of Gi(氣). Results : In Neijing(內經) and Nanjing, the basic point of view for Kidney is the same. That is explained in line with attributes of convergence(收斂). 'Life Gate(命門)' is a term to express the divergence feature(發散機能) of kidney. Moving Energy between two kidneys is used to mean the mainspring of human body activity. The Gi in human body loses altitude turning left(左旋而下降) and gains height turning right(右旋而上升). Conclusion : Watching on functional aspect, there are two names for kidney. One is 'Kidney(腎)' which collects the losing altitude turning left and the other is 'Life Gate' which rises turning right. Moreover, the fundamental power that effectuate the uplift movement is Moving Energy between two kidneys. This kind model is a way that can be understood syntagmatically the Kidney on Left & Life Gate on Right and the Moving Energy between two kidneys without any gainsaying the original of Nanjing.

• Journal of the Korean Wood Science and Technology
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• 제44권6호
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• pp.821-827
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• 2016

This study evaluates the economic feasibility of industrializing fluidized bed dryer for wood particles. The theoretically required heat energy and energy efficiency were evaluated using a pilot scale fluidized bed dryer. When Mongolian Oak wood particles with 50% initial moisture content were dried in the fluidized bed dryer with air of $70^{\circ}C$ air circulating at 1.1-1.3 m/s for 30 minutes, the total theoretically required heat energy was 2,177 kJ. Of this, 1,763 kJ (approximately 81.0%) was used to heat the air flowing in from outside the dryer and 386 kJ (approximately 17.7%) was used to heat and remove water from the wood particles. Actual energy consumed was 7,560 kJ, giving energy efficiency of 28.8%. Thus, to industrialize a drying method such as fluidized bed drying, where the dryer volume is significantly larger than the volume of wood particles, it is necessary to minimize energy loss and maximize energy efficiency by designing the dryer size considering the amount of wood particles and choosing a suitable air circulation rate.