• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.104-114
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• 1996

For the improvement of productivity, the reduction of cost and time for manufacturing is mandatory, especially in the field of electromic industry. The study is concerned with a practical means of systematic assistance to formability estimation and selection of reliable design specification for electronic sheet metal parts. The objective of this research work is to develop a simulation system which hops to analyze the target processes with the finite element method and to acquire available design data quickly and exactly. The simulation system developed in the study consists of design verification, selection of optimal combination of parameters, knowledge acquisition and graphical user interface(GUI). Design verification is automatically carried out by using the finite element method. A data base management system and nomograms are utilized for knowledge acquisition. The developed system has been applied to some major sheet metal forming operations such as flanging, embossing, bending and blanking. According to the simulated results, the validation of the target processes has been confirmend. Analysis data, estimation rules of formability and graphical representation of the analysis have been employed for the designer's understanding and evaluation, thus providing a practical means of robust design and evaluation of forma- bility for producing electronic sheet metal parts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.918-923
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• 1994

For the improvement of productivity, the reduction of cost and time for manufacturing is mandatory, especially in the field of electronic industry. The study is concemed with a practical means of systematic assistance to formability estimation and selection of reliable design specification for electronic sheet metal parts. The objective of this research work is to develop a simulation system which helps to analyze the target processes with the finite element method and to acquire available design data quickly and exactly and exactly. The simulation system developed in the study consists of design verification, selection of optimal combination of parameters, knowledge acquisition and graphical user interface(GUI). Design verification is automatically carried out by using the finite element method. A data base management system and nomograms are utilized for knowledge acquistion. The developed system has been applied to some major sheet metal forming operations such as flanging, embossing, bending and blanking. According to the simulated results, the validation of the target processes has been confirmed. Analysis data, estimation rules of formability and graphical representation of the analysis have been employed for the designer's understanfing and evaluation, thus providing a practical means of robot design and evaluation of formability for production electronic sheet metal parts.

• Herbal Formula Science
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• v.24 no.3
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• pp.233-242
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• 2016

Objective : Chronic renal failure(CRF) is defined as a permanent reduction in glomerular filtration rate(GFR), resulting in Structural and functional abnormalities. The purpose of this thesis is to report the improvement of a CRF stage4 on stroke patient through integrative medicine therapy.Methods : We treated the patient with herbal medication(Sibjeondaebo-tang gagambang), acupuncture and moxibustion as well as Western medication. We measured the Creatinine, BUN, eGFR in the serum and observed clinical symptoms During 4monthsResult : After treatment, the level of BUN and Creatinine was decreased and eGFR was increased. And the symptoms of CRF(edema, anorexia, general weakness) were improved.Conclusion : This study suggests that Integrative Medicine Therapy is effective in the treatment of CRF symptoms. In the future, for the effective management of CRF, It is considered necessary to build a systematic integrative medicine therapy.

• KIEAE Journal
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• v.12 no.6
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• pp.39-47
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• 2012

Recently, the green building and energy connection system are establishing. But, National certification system for environment-Friendly Buildings is indicated hangup about energy efficiency of building. Commissioning, energy conservation, renewable energy, carbon dioxide emissions, it is determined that the energy associated with LEED and GBCC four items of the comparative analysis showed the following results. First, on the practical performance of the system after the completion of commissioning of the energy associated with the system completed until after the final performance for secure operation from the planning stage to verify and document systematically how to perform, but the domestic review and verification is incomplete. Second, the use of energy-saving and renewable energy is directly related to the energy consumption of the building, but GBCC the strengthening of standards on how to evaluate it is deemed necessary. Finally, the evaluation of the reduction of carbon dioxide emissions, LEED Unlike GBCC the life-cycle of the system without considering the global warming index only because a substantial step in the operating efficiency can not be assessed. Based on this study GBCC energy savings through efficiency to actively carry out research through a systematic analysis of the basic guidelines to proceed.

• Journal of the Korea Safety Management & Science
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• v.5 no.3
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• pp.21-30
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• 2003

This study was intended to help workplaces set up an occupational health & safety management system by investigating the certification of the system and by conducting a questionnaire to survey the necessity, purpose, effect and promotion of the system. The occupational health & safety management systems generally adopted in Korea are OHSAS 18001 and K-OHSMS 18001, which are the PDCA model, such like the quality and environment management system. Because these standards have a compatibility with other management systems, individual or integral certification is available. A telephone questionnaire was conducted with 30 workplaces in Kyeonggi Province and Incheon Metropolitan City, which have been certified for the occupational health & safety management systems (OHSAS 18001, KOSHA 2000, and/or K -OHSMS 18001). About 92 percent of them were large-sized workplaces with over 500 employees. For the question on the necessity of the system, most of the respondent answered very necessary. The purposes of the certification were to control the risks in safety and health, to have a systematic approach for accident prevention and sustainable improvement, and to comply with a range of regulations voluntarily, in that order. Most of the answers to the question on the effect of the system were prevention of accident. For the question on the promotion of the system, the most prominent answer was reduction in the workers compensation rate.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.737-744
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• 2016

The investigation of effects on fouling propensity with various viscosity of feed solutions would be better understanding for forward osmosis (FO) performance since the fouling propensity was directly influenced with solution viscosity. Therefore, this study was focused on the FO fouling with model foultants (humic acid, alginate) by altering solution viscosity with change of ionic strength (I.S) and $Ca^{2+}$ concentrations. In the comparison between humic acid and alginate, as expected, the alginate generally caused more severe fouling (almost 35.8 % of flux reduction) based on the solution characteristics (high viscosity) and fouling patterns (coil and gel layer). However, interesting point to note is that the fouling propensity of alginate was more severe even though it was applied with low viscosity of feed conditions (I.S = 20 mM, $Ca^{2+}=1mM$). This might be due to that crossed linked gel layer of alginate on the FO membrane surface could be best formed in the condition of $Ca^{2+}$ presence and higher I.S, and that is more dominant to fouling propensity than the low viscosity of feed solutions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.236-240
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• 2013

Due to difficulty of considering dynamic load in side of a computer resource and computing time, it is common that external load is assumed as ideal static load. However, structural analysis under static load cannot guarantee the safety of structural design. Recently, the systematic method to construct equivalent static load from the given dynamic load has been proposed. Previous study has calculated equivalent static load through the optimization procedure under displacement constraints. And previously reported works to distribute equivalent static load were based on ad hoc methods. However, it is appropriate to take into account the stress constraint for the safety design. Moreover, the improper selection of loading position may results in unreliable structural design. The present study proposes the methodology to optimize an equivalent static which distributed on the primary DOFs, DOFs of the constraint elements, DOF of an external load as positions. In conclusion, the reliability of proposed method is demonstrated through a global optimization.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.2
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• pp.14-24
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• 2021

This study aims to examine probable human errors when landing an airplane by the use of SHERPA(systematic human error reduction and prediction approach) and propose methods for preventing the predictive human errors. It has been reported that human errors are concerned with a lot of accidents or incidents of an airplane. It is significant to predict presumable human errors, particularly in the operation mode of human-automation interaction, and attempt to reduce the likelihood of predicted human error. By referring to task procedures and interviewing domain experts, we analyzed airplane landing task by using HTA(hierarchical task analysis) method. In total, 6 sub-tasks and 19 operations were identified from the task analysis. SHERPA method was used for predicting probable human error types for each task. As a result, we identified 31 human errors and predicted their occurrence probability and criticality. Based on them, we suggested a set of methods for minimizing the probability of the predicted human errors. From this study, it can be said that SHERPA can be effectively used for predicting probable human error types in the context of human-automation interaction needed for navigating an airplane.

• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.519-528
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• 2021

One of the most efficient designs of solar trackers for photovoltaic panels is the single-axis tracker, which holds the panels along a torque tube that is driven by a motor at the central section. These trackers have evolved to become extremely slender structures due to mechanical optimization against static load and the need of cost reduction in a very competitive market. Owing to the corresponding decrease in mechanical resistance, some of these trackers have suffered aeroelastic instability even at moderate wind speeds, leading to catastrophic failures. In the present work, an analytical and experimental approach has been developed to study that phenomenon. The analytical study has led to identify the dimensionless parameters that govern the motion of the panel-tracker structure. Also, systematic wind tunnel experiments have been carried out on a 3D aeroelastic scale model. The tests have been successful in reproducing the aeroelastic phenomena arising in real-scale cases and have allowed the identification and a close characterization of the phenomenon. The main results have been the determination of the critical velocity for torsional galloping as a function of tilt angle and a calculation methodology for the optimal sizing of solar tracker shafts.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.4
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• pp.342-350
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• 2021

Although Korea operates various systems and policies for the management of fisheries resources, it is judged that a more systematic resource management policy is needed due to the continuous decrease in the production of coastal and offshore fisheries. In this study, the catch capacity was analyzed using the DEA technique for coastal and offshore fisheries. As a result, despite the decrease in the amount of fisheries resources and the number of fishing vessels, there was a trend of increasing fishing capacity. As of 2019, the total maximum catch of offshore fishery was estimated at 820,007 tons. The actual catch was 548,159 tons and the CU was measured to be about 66.8%, which was analyzed to be an excess of about 33.2% of the catch. The total maximum catch of coastal fisheries was estimated at 187,887 tons. The actual catch was also the same value and the CU was measured to be about 100.0%. Thus, it was analyzed that there was no excess in catch. For the management of fisheries resources, it is necessary to manage the fishing capacity. To this end, policies such as scientific TAC should be promoted as well as expanding the reduction of fishing vessels.