• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.104-111
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• 1992

In this study, the heat transfer characteristics of the evaporative transpiration cooled system is analytically investigated considering the occurrence of the two-phase evaporation zone. Under the condition of the external heat input, analytical solutions of the three regions (i.e., vapor, liquid and two-phase evaporation zone) are respectively obtained using the matching conditions for the steady-state problem where properties are constant. As results, the length of the evaporation zone increases with increasing heat input and with decreasing mass flow rate. It also increases with increasing particle size, system porosity, thermal conductivity of material, inlet temperature and latent heat of coolant. The position of the lower interface of the evaporation zone have a lot of efforts on the evaporation zone length, the position of the upper interface penetrates deeper into the porous layer with lower thermal conductivity of porous material, higher system porosity and larger particle size.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1065-1069
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• 1998

This study was investigated to improve peformance of carbon negative electrode for lithium ion secondary battery. The carbon electrode was prepared by mixing with graphitic carbon material, natural graphite, and nongraphitic carbon material, petroleum cokes, which was heat-treated at $700^{\circ}C$ for l hour. Its electrochemical and charge-discharge characteristics were tested according to mixing ratio of different two types of carbon material. The carbon electrode prepared with various mixing ratio showed both charateristcs of two different types of carbon materials and the best characteristics as carbon electrode was demonstrated at mixing ratio of 1:1.

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.244-249
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• 1987

Liquid-solid extraction technique was applied to enrich volatile free acids (VFAs) from aqueous matrices. Chromosorb P was found to be an efficient solid sorbent. The unionized VFAs could be quantitatively recovered from the Chromosorb P column with ether while interfering watermiscible components were retained in the adsorbed water on the surface of Chromosorb P. The method of simple and efficient isolation-enrichment of VFAs, followed by the quantitative analysis employing stainless steel capillary column coated with Carbowax 20M containing phosphoric acid has been applied to the determination of VFAs in several aqueous samples.

• Journal of Korean Association for Spatial Structures
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• v.7 no.4
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• pp.79-87
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• 2007

The object of this study is to understand of the effectiveness characteristic in the field work which is controlled by the quality in the high-rise residential-commercial complex building. From the previous study, the quality improvement factors are investigated. Through the structured questionnaire, the opinions of the field engineers(University, Design firms, Construction company) are gathered in the improvement factors of construction phase. Comparing the results of questionnaire with the conception of field engineers, this study helps in revising and improving the quality control system including tangible factors and intangible factors in the frame work of the high-rise residential-commercial complex building project.

• KSBB Journal
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• v.7 no.3
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• pp.172-178
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• 1992

A simple and effective method has been developed for the immobilization of lipase producing Rhizopus chinensis on polyurethane foam. In this method, the fungal cells with 1, 3 specific lipase in there inside are immobilized within the foam matrix. Four types of commercially available polyurethane foam were tested. The ultimate purpose of the process is to produce low-cost biocatalysts for lipase-catalyzed reactions, which are being increasingly used for industrial applications. Effects of several parameters were studied on the cell loading and the hydrolytic activity of intracellular lipase after acetone drying. These parameters were the type, size, and amount of polyurethane foam. In all the cases, the intracellular lipase activity obtained with the foam was approximately twice greater than that obtained in the absence of the foam.

• Korean Journal of Construction Engineering and Management
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• v.11 no.4
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• pp.80-88
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• 2010

Korean government has implemented various construction technology policies to attain competitiveness. However, there have not been interested in appropriate objectives and performance evaluation of the policy implementation. Previous evaluation included only inputs during implementation process not outputs or outcomes. Therefore, this paper performs performance evaluations on 3rd general plans for construction technology that had been implemented from 2003 to 2007 by government. This analyzes both quantitative and qualitative results. The results tell us that clear and appropriate objectives and evaluation methodology should be established for effective performance evaluation. This paper will provide the basis for establishing future construction policies or plans.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.12
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• pp.571-576
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• 2015

Image dehazing has been extensively studied, but the performance evaluation method for dehazing techniques has not attracted significant interest. This paper surveys many existing performance evaluation methods of image dehazing. In order to analyze the reliability of the evaluation methods, synthetic hazy images are first reconstructed using the ground-truth color and depth image pairs, and the dehazed images are then compared with the original haze-free images. Meanwhile we also evaluate dehazing algorithms not by the dehazed images' quality but by the performance of computer vision algorithms before/after applying image dehazing. All the aforementioned evaluation methods are analyzed and compared, and research direction for improving the existing methods is discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.206-214
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• 2020

This study examined the correlation between the respiratory pattern change (RPC) and abdominal mobility (AM) according to the positive result of the subjective lumbar instability factor (SLIF) in people with chronic low back pain (CLBP). Thirty-six adults with CLBP participated in this study. Twenty-eight items of the SLIFs were examined, and the subjects were divided into three groups according to the positive response numbers (PRN). After the change lists were scored, three RPC scores [costo-diaphragmatic RPC (CDRPC), breath hold change (BHC), and total RPC (TRPC)] were obtained. The abdominal mobility (AM) was measured between the maximal inspiration and exhalation at the xiphoid (AM1) and the 10^th rib (AM2) level of the trunk. The results showed that the RPC score and AM were compared according to the positive response number of SLIF, and the relationship between them was analyzed. A positive correlation was observed between the SLIF positive response number and CDRPC score, BHC score, and total RPC score, and a negative correlation was observed between the SLIFs positive response number and AM1 and AM2. Based on the results of this study, the combination of SLIF positive responses can be a predictor of non-physiological respiratory pattern changes in people with CLBP. Clinically, this prediction is expected to help save time for screening and improve the efficiency of therapy.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1039-1052
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• 2009

Radar measurement with high temporal and spatial resolutions can be a valuable source of data, especially in the areas where rain gauge installment is not practical. However, this kind of data brings with it many errors. The objective of this paper is to propose a method to evaluate statistically the quantitative and qualitative accuracy at different radar ranges, temporal intervals and raingage densities and use a bias adjustment technique to improve the quality of radar rainfall for the purpose of hydrological application. The method is tested with the data of 2 storm events collected at Jindo (S band) and Kwanak (C band) radar stations. The obtained results show that the accuracy of radar rainfall estimation increases when time interval rises. Radar data at the shorter range seems to be more accurate than the further one, especially for C-band radar. Using the Monte Carlo simulation experiment, we find out that the sampling error of the bias between radar and gauge rainfall reduces nonlinearly with increasing raingage density. The accuracy can be improved considerably if the real-time bias adjustment is applied, making adjusted radar rainfall to be adequately good to apply for hydrological application.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.529-538
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• 1996

We investigated the occurrence of color vision loss in 70 organic solvent mixtures exposed workers and in 47 controls. Color Vision was assessed with a color arrangement test designed to identify the defective color sense, the Han Double 15-Hue Test. The results of the test were no significant difference between exposed workers and controls in the proportion of subjects who committed one or two errors. Quantitative analysis, using color confusion index(CCI), showed no signicant difference between exposed workers and controls. A significant linear correlation was present between age and CCI in both exposed workers (CCI=0.0056age + 0.94; r=0.23; p<0.05) and controls(CCI=0.0066age + 0.86; r=0.33; p<0.05). Qualitative analysis of the patterns on the hue circle showed that the prevalence of acquired dyschromatopsia was 21% in both and no significant difference. Multiple regression analyses showed that age was significantly related to color vision loss. These results did not provide evidence of a relationship between organic solvents exposure and incidence of color vision loss. In field studies for monitor the people at risk of the acquired color vision loss involving low-dose organic solvents exposed workers, both quantitative and qualitative information should be considered.