• 대한기계학회논문집A
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• 제24권7호
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• pp.1673-1680
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• 2000

The degradation of a boiler header constructed by a material, 1Cr-0.5Mo steel in a fossil power plant is observed when the header is exposed for a long period to the high temperature and pressure. The present investigations are for evaluating the effect of the degradation on the material, such as its strength changes. Reheat-treated metal is used to compare the mechanical properties of the degraded and that of reheat-treated materials. Through the investigation, following results are obtained 1) the area ratio of ferrite in the reheat-treated material is larger than that of the degraded material, 2) the hardness and tensile strength of the degraded material are lower than that of the reheat-treated material, 3) the ductile-brittle transition temperature(DBTT) increased toward high temperature region, 4) the fatigue crack growth rate(FCGR) of the degraded material is higher than that of the reheat-treated material in the region of low ΔK value while FCGR of the both materials are similar in high ΔK region.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.289-294
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• 2021

Tungsten (W) is used as a facing material for nuclear fusion reactors, and it is used in conjunction with structural materials such as copper alloy (CuCrZr), graphite, or stainless steel. On the other hand, since tungsten is a material with a high melting point, a method that can be manufactured at a lower temperature is important. Therefore, in this study, tungsten, which is a facing material, was attempted to be manufactured using a pressure sintering method. Material properties of sintered tungsten materials were analyzed for each solvent using two types of solvents, acetone and polyethylene glycol. The sintered tungsten material using acetone as a solvent exhibited a hardness value of about 255 Hv, and when polyethylene glycol was used, a hardness value of about 200 Hv was shown. The flexural strength of the sintered tungsten material was 870 MPa and 307 MPa, respectively, when acetone and polyethylene glycol were used as solvents. The sintered tungsten material using acetone as a solvent caused densification between particles, which served as a factor of increasing the strength.

• 한국실내디자인학회논문집
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• 제25권1호
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• pp.172-180
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• 2016

This study aimed to evaluate how universal design principles are embodied in the Public Service Center. It will be used for planning the basic materials of the interior environmental design for Public Service Center facilities and for developing ways to improve interior environments in order for them to be conveniently used. In studying a method, we conducted an Universal Design check list to evaluate interior environment, targeting five Public Service Center facilities located in Gwangju Metropolitan city. This study investigated the Universal Design suitability of center interior Public Service Center on the basis of the tools for Universal Design check list which was composed of supportive design, adaptable design, communicability, safety-oriented design, and accessible design. Through theoretically considering the services of Gwangju's old city hall public service center, which got divided into common space, public service space, waiting space and informative material space. Evaluation on universal design application level showed that those with best universal design application are supportiveness and safety in public service space, communication efficacy and safety in waiting space and safety and accessibility in informative material space and acceptability in waiting space had the lowest application level.

• KIEAE Journal
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• 제15권1호
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• pp.147-154
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• 2015

Environmental impact assessment techniques have been developed as a result of the worldwide efforts to reduce the environmental impact of global warming. By using the quantification method in the construction industry, it is now possible to manage the greenhouse gas is to systematically evaluate the impact on the environment over the entire construction process. In particular, the proportion of greenhouse gas emissions at the production stage of construction material occupied is high, and efforts are needed in the construction field. In this study, intended for concrete products for the construction materials, by using the LCA evaluation method, we compared the results of environmental impact assessment and carbon emissions of developing products that have been applied low-carbon technologies compared to existing products. As a result, by introducing a raw material of industrial waste, showed carbon reduction. Through a comparison of the carbon emission reduction effect of low-carbon technologies, it is intended to provide academic data for the evaluation of greenhouse gases in the construction sector and the development of low-carbon technologies of the future.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.629-633
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• 2005

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to $R^2$ value and F-value. And testing for regression model is necessary to Independence, Homoscedesticity and Normality. Also we selected optimum layout of damping material using Taguchi method. As a result of application, sound quality is improved by more quiet, powerful, expensive, smooth.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.606-607
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• 2008

Nowadays, noise and vibration phenomena of a disc brake system have been given various names that provide some definitions of sound and vibration emitted such as grind, grunt, moan, squeak, squeal, judder and wire brush. The most common and annoying noise of a disc brake system is squeal noise. It is defined as noise whose frequency content is 1 kHz and higher with excessively high and irrigating sound pressure levels. In this paper, the noise and vibration characteristics of a disc brake system have been investigated to develop the fusion-type friction material, which overcomes the low steel and non-asbestos organic friction materials. For the purpose, both experimental evaluation and complex eigenvalue analysis have been carried out.

• 한국정보과학회논문지:소프트웨어및응용
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• 제35권8호
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• pp.493-500
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• 2008

가상 대장 내시경을 위해서 환자 대장 CT 프로파일을 이용한 전자적 장세척 방법을 제안한다. 제안된 방법은 관강 영역을 cubic seeded region growing(SRG) 방법을 이용하여 추출하고, 이에 인접한 tagged material(TM)을 제거한다. TM의 경계에서 Air-TM의 partial volume(PV) 효과로 발생한 찌꺼기를 제거하고, TM-soft tissue(ST)의 PVE에 의해서 제거된 ST는 환자 CT 프로파일을 이용해서 복원한다. 제안된 방법을 16명의 가상 내시경 환자 CT 데이타에 적용해서 임상의의 주관적인 평가와 computer-aided diagnosis(CAD)의 정량적 평가에서 매우 고무적인 결과를 획득했다.

• 한국공작기계학회논문집
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• 제14권3호
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• pp.96-102
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• 2005

Acoustic Emission(AE) technique has been applied to not only material characterization evaluation but also on-line monitoring of the structural integrity. The AE source location technique is very important to identify the source, such as crack, leak detection. Since the AE waveforms obtained from sensors are very difficult to distinguish the defect signals, therefore, it is necessary to consider the signal analysis of the transient wave-form. In this study, we have divided the region of interest into a set finite elements, and calculated the arrival time differences between sensors by using the velocities at every degree from 0 to 90. A new technique for the source location of acoustic emission in fiberboard plates has been studied by introducing Wavelet Transform(WT) do-noising technique. WT is a powerful tool for processing transient signals with temporally varying spectra. If the WT de-noising was employed, we could successfully filter out the errors of source location in fiberboard plates by arrival time difference method. The accuracy of source location appeared to be significantly improved.

• 한국응용과학기술학회지
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• 제29권2호
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• pp.231-237
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• 2012

오미자 씨 오일의 화장품 소재로서 가능성을 평가하기 위해 GC와 GC/MSD를 사용하여 안정성 평가 및 성분 분석을 실시하였다. 그 결과 주요성분은 팔미틱산과 올레익산으로 나타났다. 오미자 씨 오일은 열에 의한 성분변화가 없고, 소재 자체의 안정성이 뛰어난 것으로 나타났다. 또한, DPPH(1,1-Diphenyl-2-picrylhydrazyl) 라디칼 소거능 실험을 통하여 항산화 효능을 측정한 결과 오미자 씨 오일이 마카다미아 오일과 올리브 오일에 비하여 높은 항산화 효능을 나타내었다. 콜라겐 합성능 또한 뛰어난 것으로 평가되었다. 따라서, 오미자 씨 오일은 화장품 소재용으로 유용하게 활용될 수 있는 가능성을 가진 것으로 평가되었다.

• 한국의류산업학회지
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• 제10권1호
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• pp.92-100
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• 2008

When designing protective clothing, there are something to be considered such as physiological feature of human body, acting range not to restrict physical activity, and effectiveness of material. Because the primary objective of protective clothing is to protect human body from danger and it is designed through complex designing process not likely general clothing design. However, current evaluation techniques-such as the ISO, the ASTM and the CEN, and KS-provide only the standard to evaluate the primary feature of material (testing, performance requirements, material specification, selection and application, test and care, and so on). There are no standard to evaluate influence for the human body while protective clothing put on. Especially, in Korea, there is KS to evaluate protective clothing, but it is partially translated version from ISO because of lack of core technology about this field. However, developed countries recognize it is new competitive means in the time of Global Standards and they are competing to make their own standard to global standard for the protective clothing. Therefore, it can be great opportunity for Korean clothing and textile industry to revitalize if focusing on research and development for protective clothing design based on physical activity of human body, fit evaluation technique and sizing which is currently no global standard for it and developing our standard to global standard.