• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.271-285
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• 2022

The AERMET, the AERMOD meteorological preprocessing program, mainly used for environmental impact assessment and Integrated Environmental Permit System (IEPS) in Korea, has not considered the land covers characterasitics, and used only the past meteorological data format CD-144. In this study, two results of AERMET application considering CD-144 format and ISHD format, being used internationally, were compared. Also, the atmospheric dispersion characteristics were analyzed with consideration of land cover. In the case of considered the CD-144 format, the actual wind speed was not taken into account in the weak wind (0.6~0.9m/s) and other wind speed due to the unit conversion problem. The predicted concentration considering land cover data was up to 387% larger depending on the topographic and emission conditions than without consideration of land cover. In conclusion, when using meteorological preprocessing program in AERMOD modelling, AERMET, with ISHD format, land cover characterasitics in the area should be considered.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.185-192
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• 2021

In this study, Full-scale hollow slab Mock-up with VPS(Void Plywood Slab System) was produced. Through Mock-up, the safety of the flat plate hollow slab against short-term sagging and long-term sagging is to be evaluated. The hollow rate of the mock-up specimen to which the hollow core slab was applied was designed to be 24%. When loading through concrete blocks, the most central part of the slab was deflection 8.88mm when loading. However, it shows a safe value compared to the reference value (l_n/240=17.93mm) for short-term deflection. As a result of 3 months of measurement of the mock-up experiment, the deflection at the center of the slab increased by 6.792mm from the initial deflection. In addition, it was found that the reference value by the load used suggested by KBC2016 was satisfied.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_2
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• pp.1119-1125
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• 2022

The depletion of resources and waste disposal caused by the continuous development of industry have emphasized the need to reduce consumption and production, recycle and reuse, and the importance of remanufacturing has increased in recent years. The spindle part of the aging planner miller, which is currently being remanufactured, is one of the factors that has the greatest impact on the performance of the machine tool. When designing the spindle part of the spindle shaft, there are considerations such as the configuration size bearing performance of the main shaft, but the diameter of the main shaft, the dangerous speed bearing, and the arrangement that affect the machining accuracy should be basically considered. As such, various studies have been conducted on the design of machine tool spindle spindles, but research on the reverse engineering of existing aging machine tool spindle spindles is poor. Reverse engineering is designing in the direction of improving performance by extracting specifications from already finished products, and first scanning the reverse engineered object through a 3D scanner, 3D modeling is performed based on the collected data, and then the process of deriving improvement plans by reverberating to improve performance by identifying wear and damage conditions is followed. Therefore, in this study, the purpose of this study is to provide data on reverse engineering by deriving improvement plans through optimal design for the bearing position of the aging planar Miller spindle spindle using central composite programming.

• Journal of Korea Water Resources Association
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• v.57 no.6
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• pp.393-407
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• 2024

This study was conducted with the purpose of focusing on local water supply services, identifying equity and influencing factors, and analyzing the results. Using the Coulter model for 152 local governments across the country, equity was measured for six variables, including average unit price, rates of recovering costs from water price, revenue water ratio, water supply rate, number of employees, and customer satisfaction. Among them, the level of inequality in the average unit price was the highest. As a result of trend analysis, the degree of equity of most variables decreased. In addition, through Tobit analysis, factors influencing equity such as financial independence, local tax burden, and administrative district level were confirmed. In order to provide equitable water supply services, institutional changes such as rate increases are needed. And the government and local governments must pursue various water supply plans.

• Journal of Welding and Joining
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• v.27 no.2
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• pp.76-81
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• 2009

Tandem GMAW is one of the high performance welding process and used in many industries to increase the productivity. An evaluation is presented of the mechanical properties and microstructural characteristics of the Tandem GMAW and conventional Single GMAW welds in 30mm thickness 490MPa grade steel by comparison method. Welding sequence and bead with and hight was kept, avoiding the effect of the bead shape and welding sequence. Tension, bending, hardness and Charpy impact test results of Tandem GMAW met the requirement of specification and showed similar distribution with conventional Single GMAW. Volume fraction of ferrite phase in weld metal showed little difference between Tandem GMAW and Single GMAW

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.67-69
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• 2009

수십년 간 주요 운송 수단의 한가지로 사용되고 있는 도시철도는, 사고 발생 시 큰 경제적 손실과 사회적 손실을 야기할 수 있으나, 사고의 주 원인 중 한가지인 도시철도 전력설비 고장에 대한 감시 및 진단 시스템은 적용되고 있지 않은 실정이다. 최근 이러한 전력설비 상태 감시 및 진단에 대한 필요성이 점차 커지게 되어, 도시철도 전력설비 수명예측 시스템 설계에 관한 연구 과제가 제안되어 현재 국토해양부와 건설기술평가원, 그리고 한국철도기술연구원의 주도 하에 수행되고 있다. 본문에서는 수명예측 시스템 설계에 필요한 도시철도 전력 시스템의 특성과 고장 사례를 조사하였으며, 각 도시철도 운영기관의 사용자 요구사항 설문 결과, 그리고 수명예측 시스템의 일부인 전력설비 감시진단 시스템 기초 설계 결과를 나타내었다.

• Survey Research
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• v.12 no.3
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• pp.173-186
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• 2011

We introduced the methodologies used to construct the longitudinal weights and cross-sectional weight that are required for the analysis of Korea Youth Panel Survey. To analyze the longitudinal dynamic change of the population, we derived the longitudinal weight through nonresponse adjustment based on logistic regression and post-stratification. Cross-sectional weights that are necessary to produce an asymptotically unbiased estimator of the population parameter were constructed through simple nonresponse adjustment based on overall response rate and post-stratification.

• Journal of Ocean Engineering and Technology
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• v.24 no.2
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• pp.62-66
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• 2010

The goal of this work is to establish the reliability of FCA welded joints for high strength EH36-TMCP ultra thick plate. For this, heat conduction and thermo elasto-plastic analyses have been conducted on a multi-pass, X-groove, butt-joint model to clarify the thermal and mechanical behavior (residual stresses, magnitude of the stresses, and their production and distribution mechanisms) of the weld joint. In addition, the results of the welding residual stress obtained from thermo elasto-plastic analysis was verified and compared with results obtained by XRD analysis.

• Progress in Medical Physics
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• v.10 no.1
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• pp.9-15
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• 1999

The oxygen saturation of blood can be measured by the difference absorption in optical spectra of Hb and Hb0$_2$, as the well known previous study. In this study we developed the non-invasive oxygen measurement device for diagnosis of peripheral vascular disease in lower extremity using infrared and red LED which produce a peak spectral emission at a wavelength of 660 nm, and 940 nm. To evaluate the clinical application of the oxygen measurement device, we performed lower extremity study to measure the oxygen changes in response to physiological changes within biological tissue. The results showed that oxygen saturation of blood in biological tissue can be monitored from the separation arrangement light source and detector.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.243-253
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• 2011

This paper aims to examine the moderate effects of Client's Organizational Character on the relationships between Consulting Service Quality and Business Performance. To accomplish these purposes, The questionaries of 192 were inspected to the CEO or PM having consulting experience at the companies in Daegu and kyoung-buk. First, Consulting Service Quality presented a meaningful result(+) with the Business Performance. Second, Consulting Service Quality have differential influence on Business Performance by Client' s Organizational Character.