• Journal of Computing Science and Engineering
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• v.10 no.2
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• pp.68-73
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• 2016

An efficient texture compression method is proposed based on a block matching process between the current block and the previously encoded blocks. Texture mapping is widely used to improve the quality of rendering results in real-time applications. For fast texture mapping, it is important to find an optimal trade-off between compression efficiency and computational complexity. Low-complexity methods (e.g., ETC1 and DXT1) have often been adopted in real-time rendering applications because conventional compression methods (e.g., JPEG) achieve a high compression ratio at the cost of high complexity. We propose a block matching-based compression method that can achieve a higher compression ratio than ETC1 and DXT1 while maintaining computational complexity lower than that of JPEG. Through a comparison between the proposed method and existing compression methods, we confirm our expectations on the performance of the proposed method.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.92-100
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• 2000

The model gas reaction tests were carried out to investigate the purification characteristics of methane on the exclusive catalyst for NGV. The experiment was conducted with the factors which affect the conversion efficiency of methane, such as Redox ratio, coexistence components of CO, MO, $H_2$O, precious metals and additives. The catalyst loaded with larger amount of pd and with additive La showed lower light-off temperature. In the presence of CO and NO, the conversion efficiency of methane was varied according to the kind of additive loaded. The conversion efficiency of methane was dropped for the catalyst loaded with La under lean air-fuel ratio, while it increased for the one loaded with Ti+Zr for the same condition. It was shown that the water vapor inhibited methane from oxidation by its poisoning on the surface of catalyst.

• International Journal of Human Ecology
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• v.5 no.1
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• pp.83-95
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• 2004

The purpose of the study was to examine the determinants of financial well-being of the baby boomers. With data on 1,789 households from the 1998 Survey of Consumer Finances, the study provided a profile of baby boomers using demands, resources, financial attitudes, and financial practices. The descriptive statistics showed that 18% of the baby boomers were financially well off showing that they met the guidelines for two financial ratios: liquidity and solvency ratio. The results of logistic analysis on the measures of financial well-being revealed that financial management practices played an important role in predicting boomer's financial well-being. This suggested a positive approach of financial education to the baby boomers to help them manage their current finance well as well as prepare for their retirement.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.3
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• pp.313-320
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• 1999

A PFC(Perfluorocarbon) heat pipe has been used recently for cooling of GTO(gate turn off) thyristors or diodes in electric commuter trains. The present study was conducted to determine heat transport limitation of a PFC heat pipe which is one of the important parameters in heat pipes design. The variables such as tube diameter, fill charge ratio, internal surface structure and operating temperature were examined by way of experiment. Experimental data showed that the heat transport limitation of PFC heat pipe was considerably low and mostly dependent on tube diameter, with the value of 440~500W for d$o$/=22.23mm and 150~200W for d$o$=15.88mm. The other parameters had negligible effects, except for the case of small charge ratio less than 30%. Some correlations proposed by previous studies were in agreement with data from this study within 10~30%.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.65-70
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• 2012

Carboxy-guns are used for rapid and precise injection of $CO_2$ gas to the target skin area using external power source. In the design of carboxy-gun, the most important thing is how to precisely control injection volume of $CO_2$ gas. This paper deals with the control scheme of injection volume of carboxy-gun using solenoid valve. First the amount of volume that passes through the solenoid valve under on-off time ratio control is estimated based on the assumption of compressible gas flow. The flow rate of gas is experimentally measured under the varying pressure of the gas reservoir. Two results showed good correlation to each other, thus demonstrating the validity of the volume control strategy.

• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.172-178
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• 2011

This paper presents an optimization procedure for high-efficiency design of a mixed-flow pump. Optimization techniques based on a weighted-average surrogate model are used to optimize a vane diffuser of a mixed-flow pump. Validation of the numerical results is performed through experimental data for head, power and efficiency. Three-level full factorial design is used to generate nine design points within the design space. Three-dimensional Reynoldsaveraged Navier-Stokes equations with the shear stress transport turbulence model are discretized by using finite volume approximation and solved on hexahedral grids to evaluate the efficiency as the objective function. In order to reduce pressure loss in the vane diffuser, two variables defining the straight vane length ratio and the diffusion area ratio are selected as design variables in the present optimization. As the results of the design optimization, the efficiency at the design flow coefficient is improved by 7.05% and the off-design efficiencies are also improved in comparison with the reference design.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2369-2374
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• 2008

In the precision hot plate for wafer processing, the temperature uniformity of upper plate surface is one of the key factors affecting the quality of wafers. Precision hot plates require temperature variations less than ${\pm}1.5%$ during heating to $120^{\circ}C$. In this study, we have manufactured the flat plate heat pipe hot chuck of circle type(300mm) and investigated the operating characteristics of flat plate heat pipe hot chuck experimentally. Various liquids(aceton, FC-40, water) were used as the working fluid and charging ratio was changed($14{\sim}36\;vol.%$). Several cases were tested to improve temperature uniformity. Major working fluid to be investigated was water. Using water, various parameters such as charging ratio, wafer operation on-off time, different working fluids. In case of water, the temperature uniformity was ${\pm}1.5%$, response time of wafer were investigated.

• Journal of Soil and Groundwater Environment
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• v.10 no.6
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• pp.68-74
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• 2005

This study was carried out to evaluate the feasibility of field-scale sequential soil washing process for remediation on Kyongsangnamdo D mine soils which was heavily contaminated by arsonic. Arsenic concentration of untreated soils was $321\pm32mg/kg$. By applying the basic operating condition which was proposed from several pilot-scale experiments, arsenic concentration of treated soils was reduced 2.04 mg/kg ($99\%$ removal efficiency). We optimized the basic operating condition (mainly on washing solution concentration, cut-off size, and mixing ratio) to improve efficiently and economically the field-scale sequential soil washing process. The resulting optimized conditions were that solution concentration is 0.2M HCl, 1.0M HCl, 1.0M NaOH, that the cut-off size is 0.15mm (seive $\sharp$100), and that the mixing ratio is 1 3. Also, the optimized pH value for soil washing effluent treatment was 6 (33 ppb), in which the precipitation disruption caused by supersaturation of the floe did not occur. Results of TCLP tests showed that arsenic concentration from the washed gravels was 1.043 mg/L, that from soils ND (not detected), and that from filter cakes 0.066 mg/L. Also, the water content as a percentage of dewatered sludges was low $(48\%)$ and so the dewatered sludges can be disposed by landfilling. Through these results, we can concluded that tile field-scale sequential soil washing process developed in this study is adopted for remediation of arsenic-contaminated soils.

• Journal of the Korea Safety Management & Science
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• v.4 no.4
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• pp.109-118
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• 2002

Such effects would be paid off in the right way only when management of the firms perform marketing activities focusing on long term effectiveness, which would drive company profits up and keep them for long. Demands of customers are being changed and varied. In this result with the advantage of mass marketing and database marketing have been drawing attentions from company. To fulfill these demands of customer, they need a concept of eCRM(Web based Customer Relationship Management), and go from selling products and services, or gathering customer requests, up to the phase of solving customer's problem by real time or previous action. With the help of internet, the frequency and speed of the problem solving has improved greatly. For these purposes, we try to determine the most important and most urgent factors in eCRM: utilization by using SN Ratio Decision making, one of the Multi-criteria decision-making methods SN Ratio Decision making is widely used for determining relative magnitude per evaluation item, i. e. priority on problems and is expected to make more systematic and objective evaluations than conventional methods do. Even in the present situation where any general criterion on eCRM dose not exist, utilization of eCRM is expected to be actively continued, which will cause many problems. In this regard, evaluating eCRM counts.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.411-414
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• 1999

Five reinforced concrete rigid frame and masonry infilled wall and cut off type masonry infilled wall were constructed and tesed during vertical and cycle loads simultaneously. Experimental programs were accomplished to evaluate the structural performance of test spcimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. Test variables are hoop reinforcement ratio and masonry infilled wall with on without. All the specimens were modelling in one-third scale size.