• Journal of Preventive Medicine and Public Health
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• 제36권2호
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• pp.125-130
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• 2003

Objectives : This study evaluated the stress of community residents using the General Health Questionnaire, GHQ-60, as an instrument of stress measurement. Methods : The study included 2100 residents, aged 20 and over, living in three areas, a large city, a medium sized city and a rural area, between June and September 2001. A questionnaire interviewing method was used to collect data. The data were analyzed using a t-test, ANOVA, Pearson's correlation coefficients and multiple regression analysis. Results : In this study, the degree of stress, as measured by the GHQ-60, was shown to be significantly higher in the following categories: females, people over 60 years old, people engaged in the primary industries and labor work, low incomes, the divorced and the bereaved, people who received no more than an elementary education, people who suffer from chronic diseases and non-exercisers. A factor analysis suggested that there were three factors of social dysfunction factors; psychosomatic symptom, and depression and anxiety, The social dysfunction factors was statistically significant for the groups described above. The factor of psychosomatic symptoms was statistically significant in the rural residents, and in the groups describedabove. The depression and anxiety factor was statistically significant in the large city residents, people aged between 20-29 years, students, unmarried persons, university graduates and those having suffered from chronic diseases. From the multiple linear regression analyses, chronic disease, exercise, gender and income, proved to be significant stress related factors Conclusions : This study suggests that special attention should be given to the management of the chronic invalided, non-exercisers, females and snail income earners, in order to maintain and promote the psychological health of residents in a community.

• 한국임상수의학회지
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• 제34권3호
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• pp.189-192
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• 2017

Thirteen dogs were diagnosed as congenital extrahepatic single PSS by intraoperative mesenteric portovenography or computed tomographic examination, repair surgery was performed by using an ameroid constrictor. Hepatic size was measured from the right lateral view using liver length/T11 length ratio. This measurement was performed on follow-up check of PSS ligation patients. Hepatic size parameter of pre-operative PSS patients is $4.13{\pm}0.13$ (range, 3.11-4.83). After surgery, hepatic size parameter of post-operative PSS patients is $4.79{\pm}0.19$ (range, 3.78- 5.93). Although follow-up periods varied 2 and 26 weeks, all patients showed increased liver size compared to that on pre-operative radiographs (P < 0.01). The increase rate was 1.01-1.46 times than those of preoperative radiographs. But in 5 patients, post hepatic liver size was small compared to the others, which showed low increase rate of body weight, total protein, albumin, and glucose level. It was thought that small value of hepatic size parameter was due to delay of hepatic regeneration. In conclusion, radiographic hepatic size parameter of pre- and post-operative patients is considered an effective evaluation for restoring after PSS surgery.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.389-389
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• 2012

Molybdenum is one of the most important materials used as a back ohmic contact for $Cu(In,Ga)(Se,S)_2$ (CIGS) solar cells because it has good electrical properties as an inert and mechanically durable substrate during the absorber film growth. Sputter deposition is the common deposition process for Mo thin films. Molybdenum thin films were deposited on soda lime glass (SLG) substrates using direct-current planar magnetron sputtering technique. The outdiffusion of Na from the SLG through the Mo film to the CIGS based solar cell, also plays an important role in enhancing the device electrical properties and its performance. The structure, surface morphology and electrical characteristics of Mo thin films are generally dependent on deposition parameters such as DC power, pressure, distance between target and substrate, and deposition temperature. The aim of the present study is to show the resistivity of Mo layers, their crystallinity and morphologies, which are influenced by the substrate temperature. The thickness of Mo films is measured by Tencor-P1 profiler. The crystal structures are analyzed using X-ray diffraction (XRD: X'Pert MPD PRO / Philips). The resistivity of Mo thin films was measured by Hall effect measurement system (HMS-3000/0.55T). The surface morphology and grain shape of the films were examined by field emission scanning electron microscopy (FESEM: Hitachi S-4300). The chemical composition of the films was obtained by the energy dispersive X-ray spectroscopy (EDX). Finally the optimum substrate temperature as well as deposition conditions for Mo thin films will be developed.

• 한국의류학회지
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• 제9권3호
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• pp.1-7
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• 1985

연구의 목적은 의류생산에 있어서 동양(Oriental women)과 서양여자(Caucasian women: U.S.A)의 인체계측에 의한 치수의 비교를 하였다. 연구자료는 동양여자 100명과 서양여자 970명의 자료로 비교하였다. 동양여자의 인체계측치는 1981년 4월 일본에서 필자에 의해 수집되고 서양여자의 인체계측치는 1976년 11월부터 1977년 2월 미국(U.S.A by the Quartermaster Corps of the United States Army)에서 인체계측을 한 자료이다. 동양과 서양여자의 인체계측치 중에서 각각 32항목을 선출하여 비교된 것은 높이항목과 길이항목(height-related measurements; height and length), 나비항특(surface measurements; breadth and depth) , 둘레항목(measurement of circumference)이다. 32항목을 평균치의 t-test로 동양인과 서양인을 비교한 결과, 모든 항목에서 P<.001 수준에서 유의한 차를 보였다. 그 중에서 머리둘레, 목둘레, 손목둘레, 팔굼치둘레, 손바닥둘레의 항목에서는 동양인이 서양인에 비해서 큰 값을 나타냈다. 그 외에 27개 항목은 동양인이 전부 높거나, 길거나, 또는 큰 값을 나타냈다. 표준편차에서 보이는 바와 같이 서양인자가 동양여자보다 크고, 특히 높이 항목, 길이항목(height-related measurements)이 더 높거나 길다. 이러한 결과로서 동양과 서양여자의 인종적인 측면에서, 다양한 의류생산에 있어서 고려해야 할 것 같다. 이 동양과 서양여자의 인체계측비교에 중요한 요점을 두고 연구한 것은 의류생산과정에 있어서, size설정, 보다 미적인 design, 의복구성을 위한 등등에 고려되겠으나, 특히 미국과 같은 대량생산국에서 동양과의 무역(import or export)에 있어서 중요하게 고려가 될것이며, 나날이 발전하는 우리나라의 의류무역에도 고려되리라 본다. 뒤에 recommendations for future research에서 말한 바와 같이 서양과 한국여자의 입체계측비교를 하며 우리나라의 의류무역(수출)에 도움이 되었으면 한다.

• 열처리공학회지
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• 제9권1호
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• pp.69-77
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• 1996

The fatigue crack initiation behavior of plasma ion nitrided SACM645 steel was investigated through the rotary bending fatigue test and residual stress measurement by XRD. It was shown by XRD and EPMA that the plasma ion nitrided surface was composed of ${\gamma}^{\prime}(Fe_4N)$phase and ${\varepsilon}(Fe_{2-3}N)$phase, and that the nitrogen atoms existed in Fe matrix in diffusion layer. The OM, SEM and Auger spectroscopy showed that the depth of compound layer, mixed compound and diffusion layer, and diffusion layer was $8{\mu}m$, $30{\mu}m$ and $300{\mu}m$, respectively. However, the microhardness test showed that the depth of hardened layer was $500{\mu}m$. The tensile strength of the ion nitrided SACM645 was lower than that of the unnitrided SACM645, and the ion nitrided specimen was fractured without plastic deformation. The nitrided SACM645 showed much poorer low cycle fatigue properties than the unnitrided one. In rotary bending fatigue, the fatigue strength of the ion nitrided SACM645 was higher than that of the unnitrided specimen, and the fatigue crack initiation sites changed by applied fatigue stress levels. The XRD result showed that the ion nitrided SACM645 has the compressive residual stress from surface to $600{\mu}m$ deep and the tensile residual stress from $600{\mu}m$ to deeper site. It is thought that crack initiation takes place at the point where the total stress of residual stress and applied stress is maximum.

• 한국대기환경학회지
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• 제22권1호
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• pp.63-71
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• 2006

An automated carbonyl measurement system was constructed. Atmospheric carbonyl compounds were extracted onto DNPH containing collection solution while flowing through a glass coil. Each carbonyl species was separated on a HPLC column and quantified by UV absorption detector. Using this system, carbonyl compounds were continuously measured at the campus of Korea University in Seoul, Korea during June, 2005. Sampling resolution was 30 minutes and the detection limit of HCHO was 0.19 ppbv. Also, $\O_{3}$, it's precursors, and meteorological parameters were measured. The maximum, minimum, average, and median concentrations of HCHO during the whole experiment was 35.8 ppbv, 1.4 ppbv, 11.7 ppbv, and 9.3 ppbv respectively. Formaldehyde showed a distinct diurnal variation with a broad maximum around 13 $\sim$ 15, which was 1 $\sim$ 3 hours ahead of an ozone maximum. During a couple of days, however, HCHO concentrations were kept high through the night or increased concomitantly with NOx in the morning. These results imply that HCHO was mainly produced from the photochemical oxidation of VOCs, but local emission sources couldn't be ruled out. The differences between daily maximum and minimum of $O_{3}$ and HCHO were calculated for 11 days of June, when typical diurnal variations were observed for the two species. A strong positive correlation was found between $\Delta O_{3}$ and $\Delta HCHO$ and the average mole ratio of $\Delta HCHO$ to $\Delta O_{3}$ was 2.6. It indicates that formaldehyde played a key role in $\Delta O_{3}$ production as an indicator species in Metropolitan Seoul during June, 2005.

• 한국건설관리학회논문집
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• 제8권2호
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• pp.155-163
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• 2007

건설프로젝트를 수행하는 과정에 있어 계약당사자간에 다양한 계약방식에 기초하여 시설물 건설에 요구되는 업무 또는 서비스를 제공하고 있으나, 건설사업의 주요 성과지표라 할 수 있는 비용, 일정, 안전등의 측면에서 계약방식에 따라 발생할 수 있는 성과의 차이에 대한 실증적 인 비교연구는 미흡한 실정이다. 건설사업이 다수의 건설전문조직과 계약을 기반으로 운영되는 프로젝트라는 특성을 고려할 때 계약방식의 유형에 따라 사업성과에 대한 차이를 비교분석 함으로써 계약방식 선정에 대한 적정 의사결정을 지원하는데 유효한 자료를 제공할 수 있다. 이에 본 연구에서는 건설계약방식 중 실비정산방식과 총액계약방식을 대상으로 건설사업의 주요 성과에 대한 비교 분석을 시도하였다. 계약방식별 프로젝트 성과는 미국 Construction Industry Institute(CII)의 Benchmarking and Metrics(BM&M) 프로그램에서 활용하는 성과측정기준을 기초로 비용, 공정, 안전, 변경, 재작업(rework) 등 5개 분야를 대상으로 하였다. 또한 계약방식으로 인한 각종 성과지표의 차이가 통계적 의미를 지니고 있는가를 판단하기 위하여 통계적 기법인 t-test를 이용하여 데이터의 유의성을 분석하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권9호
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• pp.623-627
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• 1999

We report a new in-situ fluorine passivation method without in implantation by employing excimer laser annealing of $SiO_{x}F_{y}$/a-Si structure and its effects on p-channel poly-Si TFTs. The proposed method doesn't require any additional annealing step and is a low temperature process because fluorine passivation is simultaneous with excimer-laser-induced crystallization. A in-situ fluorine passivation by the proposed method was verified form XPS analysis and conductivity measurement. From experimental results, it has been shown that the proposed method is effective to improve the electrical characteristics, specially field-effect mobility, and the electrical stability of p-channel poly-Si TFTs. The improvement id due to fluorine passivation, which reduces the trap state density and forms the strong Si-F bonds in poly-Si channel and $SiO_2/poly-Si$ interface. From these results, the high performance poly-Si TFTs canbe obtained by employing the excimer-laser-induced fluorine passivation method.

• Macromolecular Research
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• 제8권6호
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• pp.276-284
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• 2000

A wettability chemogradient on poly(L-lactide-co-glycolide) (PLGA) films was prepared by treating the films in air with corona from a knife-type electrode whose power increases gradually along the sample length. The PLGA surfaces oxidized gradually with the increasing corona power, and the wettability chemogradient was created on the surfaces as evidenced by the measurement of water contact angles and electron spectroscopy for chemical analysis. The wettability chemogradient PLGA surfaces were used to investigate the interaction of four different types of cells such as hepatoma (Hep G2), osteoblast (MG 63), bovine aortic endothelial (CPAE), and fibroblast (NIH/3T3) cells in terms of the surface hydrophilicity/hydrophobicity of PLGA. The cells adhered and grown on the chemogradient surface along the sample length were counted and observed by scanning electron microscopy. It was observed that the cells were adhered, spread, and grown more onto the positions with moderate hydrophilicity of the wettability chemogradient PLGA surface than the more hydrophobic or hydrophillic positions, regardless of the cell types used. The maximum adhesion and growth of the cells appeared at around water contact angles of 53～55°. This result seems closely related with the serum protein adsorption on the surface; the serum proteins were also adsorbed more onto the positions with moderate hydrophilicity of the wettability chemogradient surface. It seems that the wettability plays important roles for cell adhesion, spreading and growth on the PLGA surface. The surface modification technique used in this study may be applicable tothe area of tissue engineering for the improvement of tissue compatibility of films- or scaffold-type substrates.

• Corrosion Science and Technology
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• 제17권1호
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• pp.20-29
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• 2018

Ti and its alloys show the excellent corrosion resistance to chloride environments, but they show less corrosion resistance in HCl, $H_2SO_4$, NaOH, $H_3PO_4$, and especially HF environments at high temperature and concentration. In this study, we used the commercially pure titanium and Ti-6Al-4V alloy, and evaluated the effect of the manufacturing process on the electrochemical properties. We used commercial products of rolled and forged materials, and made additive manufactured materials by DMT (Directed Metal Tooling) method. We annealed each specimen at $760^{\circ}C$ for one hour and then air cooled. We performed anodic polarization test, AC impedance measurement, and Mott-Schottky plot to evaluate the electrochemical properties. Despite of the difference of its microstructure of CP-Ti and Ti-6Al-4V alloys by the manufacturing process, the anodic polarization behavior was similar in 20% sulfuric acid. However, the addition of 0.1% hydrofluoric acid degraded the electrochemical properties. Among three kinds of the manufacturing process, the electrochemical properties of additive manufactured CP-Ti, and Ti-6Al-4V alloys were the lowest. It is noted that the test materials showed a Warburg impedance in HF acid environments.