• 대한안전경영과학회지
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• 제17권2호
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• pp.147-152
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• 2015

Through the inspector's real name to improve the quality of inspection is to show the design Radiological examination pursuant to the Ordinance of the Ministry of Health and Welfare for patient safety in the Image. However, the use of existing and in EMR, equipment within the handwriting input, the individual initial use has a problem. In this study, increasing the stability of the patient and the precise inspection, In order to increase the efficiency and convenience than the real-name system for quality control inspectors of medical equipment, Using the EMR and PACS developed and applied to evaluate the usefulness of automatic enrollment. Enter your information in the EMR, which was developed markers that inspectors use to compare the before and after images PACS satisfaction. Convenience than using traditional, consistency, the entry of the missing were higher as a statistically significant difference. A test strip automatic enrollment programs are developed in this study. You can increase the stability of the patient by checking the image to show the real tester, we expect the quality of care would be improved.

• 설비공학논문집
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• 제17권10호
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• pp.883-890
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• 2005

In this study, 2 pure hydrocarbon refrigerants of R1270 (Propylene) and R290 (Propane) and 3 binary mixtures composed of R1270, R29O and R152a were tested in a refrigerating bench tester with a scroll compressor in an attempt to substitute R502 used in most of the low temperature applications. The test bench provided 3\sim3.5$ kW capacity and water and water/glycol mixture were employed as the secondary heat transfer fluids. All tests were conducted under the same external conditions resulting in the average saturation temperatures of -28 and $45^{\circ}C$ in the evaporator and condenser, respectively. Test results showed that all refrigerants tested had $9.6\sim18.7\%$ higher capacity and $17.1\sim27.3\%$ higher COP than R502. The compressor discharge temperature of R1270 was similar to that of R502 while those of all other refrigerants were $23.7\sim27.9\%$ lower than that of R502. For all alternative refrigerants, the amount of charge was reduced up to $60\%$ as compared to R502. Overall, these alternative refrigerants offer better system performance and reliability than R502 and can be used as long term substitutes for R502 due to their excellent environmental properties.

• 폴리머
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• 제27권1호
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• pp.52-60
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• 2003

본 연구에서는 탄소섬유 강화 에폭시 수지 복합재료의 충격 특성 향상을 위해 탄소섬유표면에 전해 및 무전해 니켈도금처리를 하였으며, 이때 각각의 니켈도금법에 따른 충격 특성을 비교 고찰하였다. 도금된 탄소섬유의 표면 특성은 XRD, SEM, 그리고 접촉각 측정을 통해 관찰하였고, 탄소섬유 강화 복합재료의 충격 특성은 Izod형의 충격시험기를 이용하여 분석하였다. 실험결과, 무전해 니켈도금층에는 전해도금층과는 달리 Ni-P 합금이 포함된 것이 XRD를 통하여 확인되었으며, 전해 니켈도금된 탄소섬유가 무전해 니켈도금된 것보다 표면자유에너지가 큰 것이 접촉각 측정을 통해 관찰되었다. 한편, 무전해 니켈도금된 탄소섬유 강화 에폭시 수지 복합재료는 충격강도가 크게 증가하였으나, 전해 니켈도금된 복합재료의 경우는 충격강도가 증가하지 않았다. 이러한 결과는 각각의 도금법에 따른 젖음성의 차이가 탄소섬유 강화 복합재료의 연성을 변화시켜 충격강도 증가에 주요하게 작용되었기 때문으로 사료된다.

• 한국태양에너지학회 논문집
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• 제40권5호
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• pp.35-45
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• 2020

Photovoltaic (PV) power system prices have been steadily dropping in recent years due to their mass production and advances in relevant technology. Crystalline silicon (c-Si wafers) account for the largest share of the price of solar cells; reducing the thickness of these wafers is an essential part of increasing the price competitiveness of PV power systems. However, reducing the thickness of c-Si wafers is challenging; typically, phenomena such as bowing and cracking are encountered. While several approaches to address the bowing phenomenon of the c-Si solar cells exist, the only method to study the crack phenomenon (related to the strength of the c-Si solar cells) is the bending test method. Moreover, studies on determining the strength properties of the solar cells have focused largely on c-Si wafers, while those on the strength properties of front and rear-side electrodes and SiNx, the other components of c-Si solar cells, are scarce. In this study, we analyzed the strength characteristics of each layer of c-Si solar cells. The strength characteristics of the sawing mark direction produced during the production of c-Si wafers were also tested. Experiments were conducted using a 4bending tester for a specially manufactured c-Si solar cell. The results indicate that the back side electrode is the main component that experienced bowing, while the front electrode was the primary component regulating the strength of the c-Si solar cell.

• 한국가스학회지
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• 제8권1호
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• pp.1-6
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• 2004

선박용 열교환기의 냉각수로 사용되고 있는 해수의 입구온도는 스팀터빈콘덴서의 경우 약 $25^{\circ}C$이고 출구온도는 약 $60^{\circ}C$이며, 오일쿨러의 경우 출구온도는 약 $40^{\circ}C$이다. 이러한 해수의 온도 변화는 열교환기 세관재의 부식특성에 크게 영향을 미친다. 그러므로 부식손상을 최소화하면서 열교환 효율을 최대로 유지할 수 있는 냉각용액의 온도설정은 매우 중요하다. 따라서 본 연구에서는 $3.5\%$ NaCl + $0.1\%\;NH_4OH$ 수용액의 유동하에서 선박용 열교환기 세관재로 사용되고 있는 Al-황동의 분극 및 응력부식균열 실험을 실시하여 분극특성, 응력부식균열거동 및 탈아연특성에 미치는 용액의 온도의 영향에 대하여 고찰하였다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.29-30
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• 2001

This paper presents some results of plasma nitriding on hard chromium deposit. The substrates were C45 steel and $30~50{\;}\mu\textrm{m}$ of chromium deposit by electroplating was formed. Plasma nitriding was carried out in a plasma nitriding system with $95NH_3{\;}+{\;}SCH_4$ atmosphere at the pressure about 600 Pa and different temperature from $450^{\circ}C{\;}to{\;}720^{\circ}C$ for various time. Optical microscopy and X-ray diffraction were used to evaluate the characteristics of surface nitride layer formed by nitrogen diffusion from plasma atmosphere inward iCr coating and interface carbide layer formed by carbon diffusion from substrate outward Cr coating. The microhardness was measured using microhareness tester at the load of 100 gf. Corrosion resistance was evaluated using the potentiodynamic measurement in 3.5% NaG solution. A saturated calomel electrode (SiCE) was used as the reference electrode. Fig.1 shows the typical microstructures of top surface and cross-section for nitrided and unnitrided samples. Aaer plasma nitriding a sandwich structure was formed consisting of surface nitride layer, center chromium layer and interface carbide layer. The thickness of nitride and carbide layers was increased with the increase of processing temperature and time. Hardness reached about 1000Hv after nitriding while 900Hv for unnitrided hard chromium deposit. X-ray diffraction indicated that surface nitrided layer was a mixture of $Cr_2N$ and CrN at low temperature and erN at high temperature (Fig.2). Anodic polarization curves showed that plasma nitriding can greatly improve the corrosion resistance of chromium e1ectrodeposit. After plasma nitriding, the corrosion potential moved to noble direction and passive current density was lower by 1 to 4 orders of magnitude compared with chromium deposit(Fig.3).

• 한국정보처리학회논문지
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• 제6권5호
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• pp.1280-1290
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• 1999

기존의 수정 영향 분석은 단일 환경을 기반으로 하기 때문에 분산 환경에 직접 적용하기 어렵다. 본 논문에서는 분산 환경에서 객체지향 소프트웨어의 수정 영향을 분석한다 객체지향 소프트례어의 수정을, 자료, 매소드, 클래스의 집합으로 구분 하여 수정 영향을 분석하였으며, 분석 결과를 DPDG(Oistributed Program Dependency Graph)에 표현하였다. DPDG는 분산 환경에서의 객체지향 소프트웨어들의 관계를 메소드, 자료요소, 클래스, 설계 문서, 서버 등을 사용하여 그래프에 표시한다 DPG는 소프트웨어에 수정 발생 시, 재시험하여야하는 소프트웨어 요소를 찾기 위한 그래프이다 따라서, DPDG를 통해 재 시험에 드는 노력을 절약할 수 있다 본 논문에서는,OPDG를 통해 발견된 절약된 재시험 요소를 방화벽 테이블로 나타내었 으며, 이를 구현하여 본 논문에서 설계한 시험 지원도구 VIST(Visua! Infonnation Structure Tester)에서 사용하였다. VIST 는 절약된 방화벽을 사용하여, 분산 객체지향 소프트웨어 시험에 드는 노력과 비용을 절약하는 도구이다.

• 한국진공학회지
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• 제4권S2호
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• pp.40-48
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• 1995

$TiB_2$-TiN double-layer coating have been prepared by ion beam enhanced deposition. AES, XRD, TEM and HRTEM were employed to characterize the $TiB_2$ layer. The microhardness of the coatings was evaluated by an ultra low-load microhardness indenter system, and the tribological behavior was examined by a ball-on-disc tribology wear tester. It was found that in a single titanium diboride layer, the composition is uniform along the depth of the film, and it is mainly composed of nanocrystalline $TiB_2$ with hexagonal structure, which resulted from the ion bombardment during the film growth. The hardness of the $TiB_2$ films increases with increasing ion energy, and approaches a maximum value of the $TiB_2$ films increases with increasing ion energy, and approaches a maximum value of 39 Gpa at ion energy of 85 keV. The tribological property of the TiB2 films is also improved by higher energy of 85keV. The tribological property of the $TiB_2$ films is also improved by higher energy ion beam bombardment. There is no major disparity in the mechanical properties of double-layer $TiB_2$/TiN coatings and TiN/$TiB_2$ coatings. Both show an improved wear resistance compared with single-layer $TiB_2$ films. The adhesion of double-layer coatings is also superior to that of single-layer films.

• 한국기계가공학회지
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• 제18권4호
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• pp.93-99
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• 2019

A cross drilling/milling Unit is an important mechanical part which is widely used in many kinds of machining tool, and various gear trains with good accuracy and reliability features are widely used in power transmission systems. A study on a novel power transmission optimization method for driving gear trains in cross drilling/milling units is presented in this paper. A commercial program for gear system simulation, Romax Designer, was used in this research to intuitively observe the gear meshing and the load distribution conditions on the gear teeth. We obtained the optimal modification value through comparing the results of repeated experiments. For validation, optimized gears were fabricated and then measured with a precision tester.

• 지질공학
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• 제31권4호
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• pp.541-547
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• 2021

비탈면의 유실, 붕락사고 등 비탈면에 대한 안정성을 파악하기 위해서 지층의 구성상태, 역학적 특성 등의 지반정보 파악이 필요하다. 이러한 지반정보를 파악하기 위해서 일반적으로 표준관입시험(SPT) 및 콘 관입시험 등이 널리 이용되고 있다. 대부분이 급경사로 이루어지고 진입로가 없는 비탈면에 대한 접근성 문제로 표준관입시험이 널리 활용되지 못하고 있다. 이러한 단점을 보완할 수 있는 있는 휴대용 장비인 Drop Cone Penetrometer(DCP)를 이용한 조사도 여러 가지 문제로 제한적으로 사용되고 있다. 따라서 본 연구에서는 비탈면 현장접근이 용이한 휴대용 시추기와 동적콘관입시험 모듈을 개발하고, 개발된 동적콘관입시험기를 이용한 결과와 동일 현장에서 수행한 표준관입시험값과 상관성을 분석하였다. 에너지전단율로 보정된 동적콘관입시험과 표준관입시험간의 상관식은 N_d' = 3.13 N'으로 나타났다.