• 시스템엔지니어링학술지
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• 제11권2호
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• pp.1-11
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• 2015

During the industrial plant system life cycle, required technologies are developed and assessed to analyze their performance, risks and costs. The assessment is called technology readiness assessment (TRA) and the measure of readiness is called technology readiness level (TRL). The TRL consists of 9 levels and through the TRL assessment, the technology to be developed and its components are assigned to their appropriate TRL. TRL assessment should be performed in each life cycle stages to monitor the technology readiness and analyze the potential risks and costs. However, even though the concept of TRL has been largely adopted by numerous organizations and industry, direct and clear assignment of target TRL for each life cycle stage has been overlooked. Direct mapping/assignment of target TRL for each life cycle has benefits as follow: (1) the technical risks condition of each life cycle stage can be better understood, (2) cost incurred if the technology development is failed can be analyzed in each life cycle stage, and (3) more effective decision making because the technology readiness achievement for each life cycle stages is agreed beforehand. In this paper, we propose a steel-making plant system life cycle and TRL assignment to each of the system life cycle stage. By directly assigning target TRL for each life cycle stages, we look forward to a more coordinated (in terms of exit criteria) and highly effective (in terms of technical risks identification and eventually prevent project failure) technology development and assessment processes.

• 한국물환경학회지
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• 제23권4호
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• pp.474-481
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• 2007

With population growth, industrialization, and urbanization within the watershed, the hydrologic response changed dramatically, resulting in increases in peak flow with lesser time to peak and total runoff with shortened time of concentration. Infiltration is directly affected by initial soil moisture condition, which is a key element to determine runoff. Influence of the initial soil moisture condition on hydrograph analysis should be evaluated to assess land use change impacts on runoff and non-point source pollution characteristics. The Long-Term Hydrologic Impact Assessment (L-THIA) model has been widely used for the estimation of the direct runoff worldwide. The L-THIA model was applied to the Little Eagle Creek (LEC) watershed and Its estimated direct runoff values were compared with the BFLOW filtered direct runoff values by other researchers. The $R^2$ value Was 0.68 and the Nash-Sutcliffe coefficient value was 0.64. Also, the L-THIA estimates were compared with those separated using optimized $BFI_{max}$ value for the Eckhardt filter. The $R^2$ value and the Nash-Sutcliffe coefficient value were 0.66 and 0.63, respectively. Although these higher statistics could indicate that the L-THIA model is good in estimating the direct runoff reasonably well, the Antecedent Moisture Condition (AMC) was not adjusted in that study, which might be responsible for mismatches in peak flow between the L-THIA estimated and the measured peak values. In this study, the L-THIA model was run with AMC adjustment for direct runoff estimation. The $R^2$ value was 0.80 and the Nash-Sutcliffe coefficient value was 0.78 for the comparison of L-THIA simulated direct runoff with the filtered direct runoff. However there was 42.44% differences in the L-THIA estimated direct runoff and filtered direct runoff. This can be explained in that about 80% of the simulation period is classified as 'AMC I' condition, which caused lower CN values and lower direct runoff estimation. Thus, the coefficients of the equation to adjust CN II to CN I and CN III depending on AMC condition were modified to minimize adjustments impacts on runoff estimation. The $R^2$ and the Nash-Sutcliffe coefficient values increase, 0.80 and 0.80 respectively. The difference in the estimated and filtered direct runoff decreased from 42.44% to 7.99%. The results obtained in this study indicate the AMC needs to be considered for accurate direct runoff estimation using the L-THIA model. Also, more researches are needed for realistic adjustment of the AMC in the L-THIA model.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2464-2476
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• 2021

Direct-contact heat transfer of a single saturated droplet upon colliding with a heated wall in the regime of film boiling was experimentally investigated using high-resolution infrared thermometry technique. This technique provides transient local wall heat flux distributions during the entire collision period. In addition, various physical parameters relevant to the mechanistic modelling of these phenomena can be measured. The obtained results show that when single droplets dynamically collide with a heated surface during film boiling above the Leidenfrost point temperature, typically determined by droplet collision dynamics without considering thermal interactions, small spots of high heat flux due to localized wetting during the collision appear as increasing We_n. A systematic comparison revealed that existing theoretical models do not consider these observed physical phenomena and have lacks in accurately predicting the amount of direct-contact heat transfer. The necessity of developing an improved model to account for the effects of local wetting during the direct-contact heat transfer process is emphasized.

• Geomechanics and Engineering
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• 제10권2호
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• pp.125-135
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• 2016

Adhesion in geotechnical engineering is the interaction between cohesive soil and a solid surface which can cause clogging in mechanized tunnelling through clayey formations. Normal piston pull out and modified direct shear tests were performed on clayey soil samples to determine which type of adhesion stress, normal or tangential, could be most effectively measured. Measured values for normal adhesion ranged from 0.9 to 18 kPa. The range of tangential adhesion was 2.4 to 10 kPa. The results indicate normal adhesion results were more accurate than those for the modified direct shear test that measure tangential adhesion. Direct shear test on identical samples did not show any correlation between measured cohesion and normal adhesion values. Normal adhesion values have shown significantly meaningful variation with consistency index and so are compatible with the base of field clogging assessment criteria. But tangential adhesion and cohesion were not compatible with these assessment criteria.

• 한국유기농업학회지
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• 제12권1호
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• pp.23-44
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• 2004

TCA(Total Cost Assessment) can be defined by a tool to evaluate actual profit about investment. Also, It can be used by method to make more reasonable decision-making in business. Enforcement of 'direct payment system' for environment friendship farmhouse of government is spreading recent times. But, it is true that it is no definite standard about appropriation of disbursement amount of money. TCA method can be utilized usefully for solution of these problem. Also, It will help to decide price grasping invisible cost and environment cost. Therefore, We tried that may can apply TCA theory in farmhouse class, and attempted economic performance estimation which use this. This study introduces TCA theory and developed applicable expense list in agriculture field. Also, We applied TCA theory to farmhouse. This theories referenced domestic and th6 foreign countries, connection literature. But, It handled part about invisible cost and social cost etc..

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.141-143
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• 2004

This paper presents the results of an investigation of the direct short term impacts of electric service interruption incurred by agriculture customers. The study used a direct visit survey to determine the customer assessment of electric service interruption and characteristic. The variation in interruption cost with the characteristics of interruptions such as duration, time of day, frequency, and day of interruption was also investigated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.144-146
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• 2004

This paper presents the results of an investigation of the direct short term impacts of electric service interruption incurred by fisheries customers. The study used a direct visit survey to determine the customer assessment of electric service interruption and characteristic. The variation in interruption cost with the characteristics of interruptions such as duration, time of day, frequency, and day of interruption was also investigated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.613-616
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• 2008

Assessment of geothermal resources like other earth resources is a starting point for decision makers or stakeholders to set up basic plan on its development and R&D policies. In this context, there have been various works on world geothermal assessment, to report different estimates from each other. In this paper, we first introduce the definition of geothermal potential mainly adopted from the article by Muffler and Cataldi (1978) and then summarize the estimates made so far referring the work by Bertani (2003). An updated estimates by Stefansson (2005) are also reviewed in terms of identified resources separately for high-temperature resources for power generation and low-temperature ones for direct-use. Recent estimate of US geothermal resources by MIT (2006) using a volumetric method with extensively accumulated data base is discussed. Finally, we introduce the first geothermal assessment in Korea recently made and discuss its importance.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.25-29
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• 2008

Economic assessment of solar thermal power generation systems was carried out by calculating the levelized electricity cost. Four different commercial (or near commercial) solar thermal power systems (parabolic trough system, power tower system with saturated steam, power tower system with molten salts, and dish-stilting system) were considered for assessment. The assessment also included sensitivity analysis covering the effects of system capacity, direct normal insolation, and the system efficiency.

• 한국안전학회지
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• 제16권4호
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• pp.134-139
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• 2001

The Risk assessment regulation(RAR) is one of the essential articles of the Occupational safety and health law for the construction industry along with safety and health management expense and safety organization regulation. However, arguments regarding the working time of the safety assessment documents, the person in charge of documentation, weakness in legislative enforcement etc. are ongoing. Thus this study aims to analyze the effectiveness of RAR for the guidance of enhancing the effectiveness of RAR. The findings are; 1) the effectiveness of RAR is recognized, however the indirect effectiveness ie, enforcement of safety activities, previewing of drawings etc. are bigger than the direct effectiveness of accident prevention, 2) to enhance the effectiveness of RAR site inspection procedure has to be utilized, 3) further research for identifying and getting rid of negative factors in RAR is recommended.