• Korean Journal of Materials Research
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• v.9 no.3
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• pp.229-233
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• 1999

DC마그네트론 스퍼터링 방식으로 $Ti/SiO_2$/Si 구조 위에 Pt(200) 박막을 배향 성장시키기 위해 증착조건(스퍼터링 가스의 종류와 압력, 기판의 온도)과 후속열처리(RTA, Furnace annealing)에 따른 Pt 박막의 전기, 결정학적 특성을 조사하였다. 실험결과, 20mTorr의 Ar+O$_2$(20%)의 혼합가스 분위기에서 기판온도를 $500^{\circ}C$로 유지하여 Pt박막을 증착하고$ 600^{\circ}C$에서 30초간 급속 열처리를 실시한 경우, 90% 이상의 결정 배항도를 갖는 Pt(200) 박막을 제작할 수 있었다. 제작된 Pt(200) 박막은 $30~40\mu$Ω.cm의 낮은 전기저항율과 우수한 열적 안정성을 나타내었으며$ 600^{\circ}C$의 고온에서 장시간 열처리를 실시하여도 전기저항율이나 우선 배향성의 변화, 박막내 미세 결함 및 열적응집현상 등이 발생되지 않았다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.243-252
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• 1987

The propagation and closure behavior of surface crack initiated at a sharply notched specimens were investigated in 5083-H113 aluminium alloy under constant amplitude of tension load by the unloading elastic compliance method. The crack shape (aspect ratio) was found to be approximately semicircular during the crack was being small and to be changed to semi-elliptical during it was being long. The propagation rate of a surface crack initiated from notch root decelerated with increasing crack length when the crack was small and then accelerated when it was large. The effect of stress ratio was large in lower .DELTA.K range, but the effective stress intensity factor range .DELTA.K$_{eff}$ was found to diminish the difference of the crack propagation rate. By considering the increase in crack closure stress with crack length and examining the microphotographs, plasticity-induced and roughness-induced crack closure mechanisms were predominant in the range of this study.y.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4543-4552
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• 2010

A leader is a special process who roles as the coordinator within multiple processes of a group. In a distributed system, leader election is the procedure of electing a coordinator. This is a very important issue for building fault-tolerant distributed systems. When two normal mobile ad hoc networks are merged, there are two leaders. This violates the safety property, so a mechanism to detect and handle are required. In mobile ad hoc distributed computing system, we propose a leader competition protocol and to prove the temporal logic to it. This solution is based on the group membership detection algorithm.

• The Korean Nurse
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• v.23 no.3 s.126
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• pp.68-76
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• 1984

본 환자를 간호하면서 절단으로 인해 신체적 고통을 받고 있는 존재로서, 생각과 정서, 욕구를 지닌 존재로서의 환자를 돕고자 시도해 보았다. 신체적인 적응을 돕기 위해서 근력강화와 관절가동역증진, 통증조절, 보조기 착용을 위한 단단의 관리, 잔여관절의 변형예방에 중점을 두었다. 심리적인 적응을 돕기 위해서 환자가 절단 수술과 수술 후 변화된 신체외모를 수용하는 과정을 증시했다. 끝으로 사회적인 면에서는 의미있는 사람들의 집단속에서 존재하는 인간으로서의 환자에게 관심을 두었다. 환자의 우측 슬관절 가동역은 완전히 회복된 상태는 아니지만 목발을 이용하여 걷거나 기타 일상생활을 하는데 불편함은 없으며 앞으로 계속적인 노력을 통해 회복될 수 있을 것이다. 그의 좌측 고관절 가동역은 정상유지되고 있으며 절단부위는 보조기 착용에 적합하게 형성되어 가고 있다. 비슷한 처지에 있는 이씨환자의 도움과 환자의 독립적인 생활태도는 환자가 자신의 불구에 적응하고 일상생활에 적응하는데 많은 도움이 되었다. 협조적이고 동정적인 환자들과 의료진의 도움으로 환자는 보호된 병원환경내에서 신체적 제한점을 주목하고 자신의 불구에 적응하면서 타인들과 원만한 관계를 유지해 왔다. 그는 앞으로 사회에 돌아가서 생활하게 될 것이다. 우리 사회는 아직도 그들에 대해 편견을 가지고 있으며 직업적 교육적 의료치료적 배려가 부족한 상태이다. 사회속에서의 적응은 병원에서의 적응보다 훨씬 더 어려울 것이며 때로는 그를 좌절하게 할 것이다. 그의 신체적 결함이 자기 자신만의 책임은 아니며 어느 누구나 사고에 희생될 가능성은 있다. 사회인들이 그들에게 관심있고 수용적인 태도를 지니고 그들의 정상 요구와 인간으로서 동등하게 살아갈 권리를 인정하고 받아들인다며 좀더 쉽게 자신의 슬픔을 극복할 수 있을 것이다.

• Annual Conference of KIPS
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• 2013.11a
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• pp.933-935
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• 2013

국내 시스템 구축(System Integration) 및 유지보수(System Maintenance) 사업은 긴 사업 기간과 함께 하나의 사업을 다양한 업체와 함께 협력하여 개발을 하며 운영되고 있다. 이 중 대형 IT서비스업체는 컨설팅 및 제안을 통해 고객의 업무와 요구사항을 파악하며, 프로젝트를 이끌기 위해 방법론을 적용하여 사업 체계 관리 및 운영을 주로 담당한다. 그런데 이와 같은 관리 위주의 사업을 진행함으로써 임직원들의 개발 역량 부족 문제가 발견되고, 이것은 시스템에 대한 이해도 부족으로 다양한 업체와 협력하는데 있어 커뮤니케이션 문제로 직결되어 시스템의 품질 및 결함에 영향을 주기 때문에 이에 대한 대책 및 예방활동이 필요하다. 또한, 작은 국내 시장에서는 이미 경쟁이 심화 되어 포화 되었으며, 대부분의 IT서비스기업은 SI사업에서 솔루션사업으로 변모하기 위해 노력 중이고 국내 시장에서 해외 시장으로 눈을 돌리고 있으므로 직원들에 대한 기술 역량이 시급한 실정이다. 이와 같은 상황에 기업은 준비가 미흡할 뿐만 아니라 해당 활동을 수행하기 위한 필요한 지식 및 방법을 익히는데 어려움이 있는 상황이다. 본 논문에서는 이러한 상황을 극복하기 위해 대형 IT서비스업체에서 진행된 개발역량강화 학습조직 적용 사례에 대해 소개를 하고, 이에 대한 효과 검증을 해보고자 한다.

• Composites Research
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• v.22 no.3
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• pp.9-17
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• 2009

Nanoindentation behaviours on the films of softer Ag film/harder Cu substrate structure were studied by the molecular dynamics method. As a result, it was shown that the stiffness and hardness of films were strongly dependent on the thickness of films. The stiffness and hardness increased with the thickness of film within a critical range as an inverse Hall-Petch relation. The stiffness and hardness of Cu substrate with Ag film less than 5 nm were observed to be lower than those of bulk silver. In particular, the flower-like dislocation loop was created on the interface by the interaction between dislocation pile-up and misfit dislocation during the indentation of Ag film/Cu substrate with film thickness less than 4 nm, which seemed to be associated with the drop of load in the indentation load versus displacement curve.

• Corrosion Science and Technology
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• v.23 no.3
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• pp.235-245
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• 2024

DLC coatings have been widely applied in industrial fields that require high corrosion resistance due to their excellent mechanical characteristics and chemical stability. In this research, effects of DLC coating thickness and defects on corrosion resistance were investigated for application of metallic bipolar plates in polymer membrane electrolyte fuel cells (PEMFCs). Results revealed that a DLC coating thickness of 0.7 ㎛ could lead to a defect size reduction of about 75.9% compared to that of 0.3 ㎛.As a result of potentiodynamic polarization experiments, the current density under a potential of 0.6 V was measured to be less than 1 ㎂/cm²,which was an excellent value. Inparticular, the delamination ratio and the decrease rate of maximum pitting depth were up to 84.8% and 63.3%, respectively, with an increase in the DLC coating thickness. These results demonstrate that DLC coating thickness and defects are factors that can affect corrosion resistance of DLC coating and its substrate.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.67-73
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• 2005

Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.

• Korean Journal of Materials Research
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• v.4 no.8
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• pp.895-905
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• 1994

The solid phase crystallization behavior of undoped amorphous $Si_{1-x}Ge_{x}$ (X=O to 0.53) alloyfilms was studied by X-ray diffractometry(XRD) and transmission electron microscopy(TEM). Thefilms were deposited on thermally oxidized 5" (100) Si wafer by MBE(Mo1ecular Beam Epitaxy) at 300'C and annealed in the temperature range of $500^{\circ}C$ ~ $625^{\circ}C$. From XRD results, it was found that the thermal budget for full crystallization of the film is significantly reduced as the Ge concentration in thefilm is increased. In addition, the results also shows that pure amorphous Si film crystallizes with astrong (111) texture while the $Si_{1-x}Ge_{x}$ alloy film crystallzes with a (311) texture suggesting that the solidphase crystallization mechanism is changed by the incorporation of Ge. TEM analysis of the crystallized filmshow that the grain morphology of the pure Si is an elliptical and/or a dendrite shape with high density ofcrystalline defects in the grains while that of the $Si_{0.47}Ge_{0.53}$ alloy is more or less equiaxed shape with muchlower density of defects. From these results, we conclude that the crystallization mechanism changes fromtwin-assisted growth mode to random growth mode as the Ge cocentration is increased.ocentration is increased.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.7 no.1
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• pp.14-22
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• 1996

This study aims to look at main problems of visiting the clinic, diagnoses and other related factors of outpatients in a private psychiatric clinic f3r children and adolescents located in Seoul. The analyses were based on the reports of 2,785 patients who were 18 years old and less, and visited the clinic during last 4 years. The results showed that the ratio of boys to girls was 2.7 to 1, and about 64% of the whole sample were 6 years old and less. Especially the percentage of patients aged 3 and less was the highest and that of schoolage and more was gradually reduced. The average number of siblings was 195 and the percentage of the first child in a family was the highest. Particularly, there were more boys in rase of one child families and more girls in case of families with 3 children and more. The chief problems were mainly language-deficit, hyperactivity, autistic behaviour, tic, aggressive behavior and academic problem. The higher frequency of diagnoses was in the order of parent-child problem, mental retardation, developmental language disorder, reactive attachment disorder, other emotional disorder, and pervasive developmental disorder. The more frequently used method fir treatments was in the sequence of psychotherapy, play therapy, parental counseling, occupational therapy and speech therapy. The results from this study were compared with those from other studies and discussed.