• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.9
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• pp.896-902
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• 2012

For most applications of the vibration energy harvesting technology as in wireless sensor networks for smart buildings and plants, the evaluation of DC output performance of vibration energy harvesters is typically required. However, there is no dedicated algorithm for the evaluation. The lack of a dedicated algorithm results from difficulties in the direct incorporation of nonlinear rectifying and regulating circuitry into finite element models of piezoelectric vibration energy harvesters. In this study, we develop a dedicated algorithm and present software based on it for the evaluation of not only AC but also DC electrical quantities. Here, an equivalent electrical circuit model is employed. The COMSOL multiphysics simulation tool is adopted for extracting equivalent electrical circuit parameters of a piezoelectric vibration energy harvester and MATLAB is used to make a graphical user interface. The AC voltage and power outputs calculated by the proposed algorithm under various conditions are compared with those by a traditional finite element analysis. The DC output voltage and power through a rectifier are obtained for varying values of smoothing capacitance and external resistance.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.648-653
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• 2006

It pollute the earth environment with systematic industrialization. Also the congestion of cities that ignore ecosystem threaten habitation environment of human. For ESSD make progress to many researches internal and external. However we don't develop model for internal environment, research evaluation of ecological polis for this. The present research put in operation that make up question experts. In the event many people know necessity of ecological development. But It point out reality with many phases. One side we need to educate, publicize about environment. make good model and cultivate process.

• Journal of Radiation Protection and Research
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• v.35 no.1
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• pp.6-11
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• 2010

Embodying the safety of radioactive waste disposal requires the relevant safety criteria and the corresponding stylized methods to demonstrate its compliance with the criteria. This paper proposes a conceptual model of risk-based safety evaluation for integrating complex potential radiation exposure situations in radioactive waste disposal. For demonstrating compliance with a risk constraint, the approach deals with important exposure scenarios from the viewpoint of the receptor to estimate the resulting risk. For respective exposure situations, it considers the occurrence probabilities of the relevant exposure scenarios as their probability of giving rise to doses to estimate the total risk to a representative person by aggregating the respective risks. In this model, an exposure scenario is simply constructed with three components:radionuclide release, radionuclide migration and environment contamination, and interaction between the contaminated media and the receptor. A set of exposure scenarios and the representative person are established from reasonable combinations of the components, based on a balance of their occurrence probabilities and the consequences. In addition, the probability of an exposure scenario is estimated on the assumption that the initiating external factors influence release mechanisms and transport pathways, and its effect on the interaction between the environment and the receptor may be covered in terms of the representative person. This integrated approach enables a systematic risk assessment for complex exposure situations of radioactive waste disposal and facilitates the evaluation of compliance with risk constraints.

• Culinary science and hospitality research
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• v.4
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• pp.167-187
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• 1998

The human resources play an important role in a hotel cooking department. The object of this study is to gain basic data for searching an effective human resources management method of cooking department in the hotel. To achieve this object, I proceeded like this. In the second chapter, I exerted myself to arrange the theoretical system on the content of the human resources management through an internal and external philological research. In the third chapter, I established conceptional research model to study factual research and three hypotheses. And I made all high-grade hotel cooking employee in Taegu and Kyung-Buk answer an questionnaire, so practiced interrelation analysis and dispersion analysis according to research hypothesis. The results are as follows. First, the result of hypothesis 1 was that three was rather a high interrelation between the human resources management factor of cooking department and its overall evaluation. Second, the result of hypothesis 2 was that three was a significant difference about the overall evaluation of cooking business management according to the position demographically. Third, the result of hypothesis 3 was that there was a significant difference according to the scholastic ability, position and the district of hotel in the demographical evaluation of human resources management factor. The limits of this study were that first, I defined the subject as the cook employee of high-grade hotel in Taegu and Kyung-Buk, second, I utilized partial variance among many variances affecting human resources management. Therefore after this study, these limits much be overcomed and multiple and scientific study must be accomplish. So human resources of cooking department in the hotel must improve more.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.3
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• pp.307-322
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• 2021

This study developed an analytical methodology for the mechanical integrity of spent nuclear fuel (SNF) cladding tubes under external pinch loads during transportation, with reference to the failure mode specified in the relevant guidelines. Special consideration was given to the degraded characteristics of SNF during dry storage, including oxide and hydride contents and orientations. The developed framework reflected a composite cladding model of elastic and plastic analysis approaches and correlation equations related to the mechanical parameters. The established models were employed for modeling the finite elements by coding their physical behaviors. A mechanical integrity evaluation of 14 × 14 PWR SNF was performed using this system. To ensure that the damage criteria met the applicable legal requirements, stress-strain analysis results were separated into elastic and plastic regions with the concept of strain energy, considering both normal and hypothetical accident conditions. Probabilistic procedures using Monte Carlo simulations and reliability evaluations were included. The evaluation results showed no probability of damage under the normal conditions, whereas there were small but considerably low probabilities under accident conditions. These results indicate that the proposed approach is a reliable predictor of SNF mechanical integrity.

• Steel and Composite Structures
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• v.39 no.4
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• pp.453-469
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• 2021

The cracking at the transverse diaphragm cutout is one of the most severe fatigue failures threatening orthotropic steel decks (OSDs), whose mechanisms and crack treatment techniques have not been fully studied. In this paper, full-scale experiments were first performed to investigate the fatigue performance of polished cutouts involving the effect of an artificial geometrical defect. Following this, comparative experimental testing for defective cutouts strengthened with carbon fiber-reinforced polymer (CFRP) was carried out. Numerical finite element analysis was also performed to verify and explain the experimental observations. Results show that the combinative effect of the wheel load and thermal residual stress constitutes the external driving force for the fatigue cracking of the cutout. Initial geometrical defects are confirmed as a critical factor affecting the fatigue cracking. The principal stress 6 mm away from the free edge of the cutout can be adopted as the nominal stress of the cutout during fatigue evaluation, and the fatigue resistance of polished cutouts is higher than Grade A in AASHTO specification. The bonded CFRP system is highly effective in extending the fatigue life of the defective cutouts. The present study provides some new insights into the fatigue evaluation and repair of OSDs.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.110-118
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• 2020

This study developed a evaluation indicators on environmental facilities highly vulnerable to flood damage from quantitative and qualitative perspectives in order to reinforce the ability or preemptive disaster prevention. At first, this study classified the facilities into structural factor and non-structural factor. The structural factor consists of 11 indicators, the non-structural factor consists of 8 internal indicators and 6 external indicators. This study is expected to be prepared for flood damage by evaluating flood vulnerability of environmental facilities.

• Journal of Fashion Business
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• v.24 no.6
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• pp.120-134
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• 2020

Recently, the beauty industry has implemented personalized services based on skin big data. To increase competitiveness in the beauty industry, systematic data measurement and evaluation indicators are necessary to select data and obtain necessary knowledge. In response, this study sought to stably enhance the accuracy of skin diagnosis based on satisfaction and reliability. To this end, the research was conducted through focus group interviews (FGI), a case study of brands, and analysis of prior research results. In particular, as a result of analyzing keywords that classify skin types by brand, common survey items for skin types were oiliness and using moisturizer, cosmetic use and vascular of skin, external stimulus and blemish & freckles, facial wrinkle, outside activities, self-consciousness, and smoke. In additioin to the common questions of the preceding study and the brand survey items, the questions concerning complex skin types, seasonal change, facial color, wrinkles and elasticity were added, and the questions were presented in a total of 40 items. In particular, it suggested that skin measurement could be conducted by focusing on elasticity and pigmentation items by reflecting the results of prior research and the opinions of FGI, and based on this, a customized service with high satisfaction and high accuracy of beauty care based on this could be proposed. We hope that this study will facilitate active self-care by providing more satisfying skin stones and personalized cosmetics proposals, thus laying the foundation for the further development of the cosmetics industry.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2915-2923
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• 2022

There is an increasing interest in passive safety systems to minimize the need for operator intervention or external power sources in nuclear power plants. Because a passive system has a weak driving force, there is greater uncertainty in the performance compared with an active system. In previous studies, several methods have been suggested to evaluate passive system reliability, and many of them estimated the failure probability using thermal-hydraulic analyses and the Monte Carlo method. However, if the functional failure of a passive system is rare, it is difficult to estimate the failure probability using conventional methods owing to their high computational time. In this paper, a procedure for the application of the Chernoff bound to the evaluation of passive system reliability is proposed. A feasibility study of the procedure was conducted on a passive decay heat removal system of a micro modular reactor in its conceptual design phase, and it was demonstrated that the passive system reliability can be evaluated without performing a large number of thermal-hydraulic analyses or Monte Carlo simulations when the system has a small failure probability. Accordingly, the advantages and constraints of applying the Chernoff bound for passive system reliability evaluation are discussed in this paper.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.4
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• pp.503-516
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• 2023

A transfer cask serves as the container for transporting and handling canisters loaded with spent nuclear fuels from light water reactors. This study focuses on a cylindrical transfer cask, standing at 5,300 mm with an external diameter of 2,170 mm, featuring impact limiters on the top and bottom sides. The base of the cask body has an openable/closable lid for loading canisters with storage modules. The transfer cask houses a canister containing spent nuclear fuels from lightweight reactors, serving as the confinement boundary while the cask itself lacks the confinement structure. The objective of this study was to conduct a structural analysis evaluation of the transfer cask, currently under development in Korea, ensuring its safety. This evaluation encompasses analyses of loads under normal, off-normal, and accident conditions, adhering to NUREG-2215. Structural integrity was assessed by comparing combined results for each load against stress limits. The results confirm that the transfer cask meets stress limits across normal, off-normal, and accident conditions, establishing its structural safety.