• 전력전자학회논문지
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• 제21권4호
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• pp.290-295
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• 2016

Socket-outlets and plugs are essential devices that supply electric power into user appliances. During plug-out operation of an engaged plug from the socket-outlet, the consistent arc between the plug and the socket-outlet could develop into heavy fires in DC systems but only a small spark in AC systems. This paper proposes a pre-/post-electrode method to prevent plugs and socket-outlets from melting by sustaining arc energy. To implement the proposed pre-/post-electrodes, an experimental plug is manufactured with two electrodes, in which a post resistance Rs is connected in between. This paper investigates the function of the post resistance Rs, in which the best value of the post resistance Rs is obtained through simulation and experiment.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.7-15
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• 2008

Currently existing high-accuracy and high-speed die sets used in reciprocal press create scratches at the surface of guide posts, steel balls, and bushes due to vertical movement of balls with point-contacts between inner surface of bushes and guide posts. Consequently, accuracy of the die set and the life span of the metal mold are reduced. However, those scratches could reduce the pre-load of the steel ball. This research designed and developed a groove-type die set which improves life span of the die set by eliminating point-contacts of steel balls with guide posts. The guide post consisted of a steel-ball retainer, a steel-ball retainer stopper, a guide bush, a guide pin, a snap ring, and a spring. The steel-ball retainer has 72 holes with 8 columns of 9 holes in each column. The inner surface of the guide bush was grinded(surface roughness: $Ra\;\\;0.2{\mu}m$, accuracy: $0\;{\sim}\;-0.002mm$) after NC turning and heat treatment. Also, a line of small intermediate pocket was processed inside of the guide bush for lubrication and elimination of foreign materials. Guide grooves of steel balls were processed using a wire EDM(Electrical Discharge Machining) after heat treatment. With such a design of the guide post stated above, loads against steel balls could be dispersed greatly by the line contacts through the guide groove between the guide post and the guide bush, and the life span of the guide post could be expanded semi-permanently.

• 전자공학회논문지A
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• 제31A권10호
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• pp.87-93
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• 1994

Ohmic contacts between Au and p-HgHg_{0.7}Cd_{0.3}Te$ with low specific contact resistance have been obtained. The contact region of the wafer is first pre-heated for 5 seconds in a rapid thermal processing equipment. The temperature reaches a maximum value of about 200$^{\circ}C$ at the end of the 5 seconds. Next, a thin Au film is formed on the contact region by immersing the sample in AuCl$_{3}$ solution. the sample is then post-annealed in the same condition as the pre-heating after Pb/In pad metals are deposited on the electroless Au contacts. The specific contact resistance measured by transmission line model is 5${\times}10^{-3}{\Omega}cm^{2}$ at 80K. RBS and differential Hall measurement data suggest that the above low resistance ohmic contact is ascribed to surface traps and increased gold diffusion rate.

• Journal of Oral Medicine and Pain
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• 제40권1호
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• pp.28-34
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• 2015

Purpose: The aim of this study is to assess the relationship between possible occlusal change after stabilization splint therapy and the research diagnostic criteria for temporomandibular disorders (RDC/TMD) Axis I diagnoses and lateral cephalometric variables. Methods: Clinical and radiographic records of 47 TMD patients wearing stablization splint were reviewed. The number of occluding teeth was recorded and lateral cephalogram was taken at pre-treatment and 6-month post-treatment. They were divided into two groups. The control group consists of patients with the unchanged number of occluding teeth throughout 6-month splint therapy (19 females and 4 males), and occlusal-loss group with the number of occluding teeth decreased (19 females and 5 males). The difference of RDC/TMD diagnoses and cephalometric variables were compared between two groups. Results: In the control group, RDC group I, muscle disorders, was 39.1% (9/23), group II, disc displacements, was 17.4% (4/23), group III OA, osteoarthritis/osteoarthrosis, was 73.9% (17/23), and group III pain, arthralgia, was 82.6% (19/23). In the occlusal-loss group, group I was 41.7% (10/24), group II was 41.7% (10/24), group III OA was 70.8% (17/24), and group III pain was 83.3% (20/24). The frequency of RDC groups was not different between two groups, analyzed by binomial logistic regression. Pre-treatment cephalometric variables were not different between two groups. However, articular angle, AB to mandibular plane and ODI decreased and gonial angle increased significantly in the occlusal-loss group, implying clockwise rotation of the mandible, between pre-treatment and 6-month post-treatment, while none of cephalometric variables showed any statistical difference in the control group. Conclusions: Change in the number of occluding teeth was not related to the RDC/TMD diagnoses. Cephalometric values changed only in the occlusal-loss group as a result of mandibular clockwise rotation. None of cephalometric variables before the stabilization splint therapy was statistically different between the control and occlusal loss group.

• 대한간호학회지
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• 제37권3호
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• pp.343-352
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• 2007

Purpose: The purpose of this study was to examine the effects of an inpatient pulmonary rehabilitation program on dyspnea, exercise capacity, and health related quality of life in inpatients with chronic lung disease. Method: This quasi experimental study was designed with a nonequivalent control group pre-post test time series. Twenty three patients were assigned to the experimental group and nineteen to the control group. The inpatient pulmonary rehabilitation program was composed of upper and lower extremity exercise, breathing retraining, inspiratory muscle training, education, relaxation and telephone contacts. This program consisted of 4 sessions with inpatients and 4 weeks at home after discharge. The control group was given a home based pulmonary rehabilitation program at the time of discharge. The outcomes were measured by the Borg score, 6MWD and the Chronic Respiratory Disease Questionnaire(CRQ). Results: There was a statistically significant difference in dyspnea between the experimental group and control group, but not among time sequence, or interaction between groups and time sequence. Also significant improvements in exercise capacity and health related quality of life were found only in the experimental group. Conclusions: An Inpatient pulmonary rehabilitation program may be a useful intervention to reduce dyspnea, and increase exercise capacity and health related quality of life for chronic lung disease patients.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.75-76
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• 2015

콘센트-플러그는 사용자부하에 전기를 공급하기 위하여 필수적으로 사용하는 전기부품이다. 활선상태인 콘센트-플러그를 임의로 차단할 경우, 교류환경에서는 반주기 마다 전류의 영점이 존재하므로 차단접점에서 발생하는 아크가 자연적으로 소호될 수 있으나 직류환경에서는 개방직전 전류가 영점을 포함하지 않고 일정하기 때문에 그에 따라 발생하는 아크는 교류에 비해 지속적이고 상대적으로 매우 큰 에너지를 방출한다. 교류에서 사용되는 플러그와 콘센트를 그대로 직류에서 사용 할 경우, 접속이 끊어 질 때 매우 큰 아크전류가 발생하여 플러그와 콘센트의 전극이 녹아서 붙는 융착 사고가 빈번히 발생한다. 본 논문은 콘센트-플러그의 융착 사고를 예방하기 위해 전극의 초기-후기접점 기법을 제안한다. 이를 구현하기 위한 기초적인 연구로서 초기-후기접점 저항을 2단계로 구분하여 접속 및 차단 시 중간단계의 접촉저항을 통하여 부하전류가 단계적으로 바뀔 수 있도록 함으로써 최종 차단 아크전류를 감소시키는 방법을 제안하고 실험을 통하여 성능을 분석하고 설계방법을 제시한다.

• 대한치과보철학회지
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• 제51권3호
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• pp.221-225
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• 2013

임시 보철물의 적절한 관리는 보철의 성공에 있어서 중요한 요소이다. 상악 전치 결손부 임시 보철물은 장경간의 결손부가 존재하거나, 타원형의 악궁을 가진 환자에서 자주 탈락하게 된다. 이는 상악 전치부가 구치부에 비해서 수평적인 힘에 더 많이 노출되며, 부가적으로 전방 캔틸레버 효과가 임시 보철물의 유지를 저해하고, 상악 전치부 임시 보철물은 하악의 기능 운동시 적절한 전방 유도를 제공하여야 하기 때문이다. 또한 임시 보철물의 최대 감합위에서 교합접촉은 지점선의 반대편에 위치하게 되어 그 자체로 임시 보철물의 탈락을 야기한다. 본 증례에서는 임시 임플란트를 이용하여 상악 전치부 보철물에 대한 전술한 유해 작용을 피할 수 있었고, 발치 후 치유기간 동안 환자에게 편안함과 만족감을 부여하였으므로 이를 보고하는 바이다.