• 국제물리치료학회지
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• 제2권2호
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• pp.308-317
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• 2011

The purpose of this study was to investigate the influence of handicraft activities on hand promptness and grasp in the elderly. Subjects were comprised of 14 senior citizens between the ages of 70-85, with 7 subjects in the experiment group and 7 in the control group. Subjects in the experiment group practiced various handicrafts twice a day, while those in the control group did not participate in any special activity. The Jebsen Taylor Hand Function Test was used to evaluate the results, while a dynamometer and pinch gauge were used to measure hand promptness and grasp. The 7 senior citizens in the experiment group were able to increase their hand promptness and grasping skills. Conclusively, handicrafts can help improve hand promptness and grasp in the elderly. Furthermore, the development and improvement of such skills can have a positive influence on the daily lives of senior citizens. Such skills are expected to improve the overall neuro-function in the elderly population.

• 대한기계학회논문집A
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• 제30권4호
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• pp.357-363
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• 2006

According to the study of grasping of the human hand, it is noted that the metacarpal link of the thumb plays the key role in power grasping. Also the face of fingertip can be discriminated into five parts depending on the grasping modalities such as pinch grasp, fingertip grasp and power grasp. In this paper, the design of the anthropomorphic robot hand which has a thumb and three fingers is proposed. A difference of SKKU hand II from the previous gripperlike robot hand is that the metacarpal bone is connected between the thumb and the palm. This thumb mechanism is specially designed to get the degree of freedom which can realize flexible motions relative to objects. Based on the analysis, the hand mechanism is developed. Since the driving circuits for the hand are embedded in the hand, only the communication lines supporting CAN protocol with DC power cable are necessary as the input. A new robot is manufactured and feasibility of the hand is validated through preliminary experiments.

• Archives of Reconstructive Microsurgery
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• 제7권2호
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• pp.95-101
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• 1998

From march 1993 to march 1998, twenty consecutive transmetacarpal replantations and revascularizations were reviewed retrospectively. Nine patients sustained severe and diffuse crush injuries, four patients had local crush injuries, and seven suffered guillotine type amputation. Six replantations and fourteen revascularizations were performed. 76 of 81 replantable digits(93%) were salvaged. 15 patients required secondary surgery, 10 patients for tendon and joint scarring and 5 for nonunions or malunions. Intrinsic muscle function and pinch and grip strengths were weak or absent. According to Chen's grading system of functional return, 2(10%) were grade I, 6(30%) were grade II, 10(50%) were grade III, and 2(10%) grade IV. The follow-up period ranged from 6months to 46 months. Only 3 patients resumed his prior occupation(one as a supervisor); 2 were permanently disabled, 4 pursued new occupations as a manual worker, 1 were still in therapy. Only two of the manual laborers were able to return to their preinjury occupation. Despite these unacceptable functional results, all patients were satisfied with the surgery.

• Structural Engineering and Mechanics
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• 제27권6호
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• pp.697-711
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• 2007

Though extensive research has been carried out for the ultimate strength of steel reinforced concrete (SRC) members under static and cyclic load, there was only limited information on the applied analysis models. Modeling of the inelastic response of SRC members can be accomplished by using a microcosmic model. However, generally used microcosmic model, which usually contains a group of parameters, is too complicated to apply in the nonlinear structural computation for large whole buildings. The intent of this paper is to develop an effective modeling approach for the reliable prediction of the inelastic response of SRC columns. Firstly, five SRC columns were tested under cyclic static load and constant axial force. Based on the experimental results, normalized trilinear skeleton curves were then put forward. Theoretical equation of normalizing point (ultimate strength point) was built up according to the load-bearing mechanism of RC columns and verified by the 5 specimens in this test and 14 SRC columns from parallel tests. Since no obvious strength deterioration and pinch effect were observed from the load-displacement curve, hysteresis rule considering only stiffness degradation was proposed through regression analysis. Compared with the experimental results, the applied analysis model is so reasonable to capture the overall cyclic response of SRC columns that it can be easily used in both static and dynamic analysis of the whole SRC structural systems.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권3호
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• pp.251-263
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• 2008

In this paper, we report an analytical modeling and 2-D Synopsys Sentaurus TCAD simulation of ion implanted silicon carbide MESFETs. The model has been developed to obtain the threshold voltage, drain-source current, intrinsic parameters such as, gate capacitance, drain-source resistance and transconductance considering different fabrication parameters such as ion dose, ion energy, ion range and annealing effect parameters. The model is useful in determining the ion implantation fabrication parameters from the optimization of the active implanted channel thickness for different ion doses resulting in the desired pinch off voltage needed for high drain current and high breakdown voltage. The drain current of approximately 10 A obtained from the analytical model agrees well with that of the Synopsys Sentaurus TCAD simulation and the breakdown voltage approximately 85 V obtained from the TCAD simulation agrees well with published experimental results. The gate-to-source capacitance and gate-to-drain capacitance, drain-source resistance and trans-conductance were studied to understand the device frequency response. Cut off and maximum frequencies of approximately 10 GHz and 29 GHz respectively were obtained from Sentaurus TCAD and verified by the Smith's chart.

• 대한인간공학회지
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• 제25권2호
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• pp.155-160
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• 2006

Motor intentional disorders have been studied by visual examination methods such as cross-response task and Luria loop. To provide more analytical, quantitative information for motor intentional disorders, the present study developed a method which evaluates force control capabilities by the index finger. The assessment method analyzes the finger force control capabilities at four stages(initiation, development, maintenance, and termination) with NK Pinch-GripTM(force resolution= 0.098 N; temporal resolution=50Hz). By applying the assessment method, a patient(age=66) with callosal legion was compared with 6 healthy males(mean age=65.5, SD=2.8), showing significant but different decreases in force control capabilities depending on hand and response location. The assessment method would be of use to better understand various aspects of motor intentional disorders such as the effects of the disorders to the neurological network of the brain and severity assessment of the disorders.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.78-82
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• 2020

In this study, MOSFETs fabricated on Si-doped, MBE-grown β-Ga₂O₃ are demonstrated. A Si-doped Ga₂O₃ epitaxial layer was grown on a Fe-doped, semi-insulating 1.5 cm × 1 cm Ga₂O₃ substrate using molecular beam epitaxy (MBE). The fabricated devices are circular type MOSFETs with a gate length of 3 ㎛, a source-drain spacing of 20 ㎛, and a gate width of 523 ㎛. The device exhibited a good pinch-off characteristic, a high on-off drain current ratio of approximately 2.7×10⁹, and a high breakdown voltage of 1,080 V, which demonstrates the potential of Ga₂O₃ for power device applications including electric vehicles, railways, and renewable energy.

• 한국전자통신학회논문지
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• 제9권8호
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• pp.853-859
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• 2014

본 연구에서는 핀치오프 된 cold-FET에서 게이트와 드레인 패드를 디임베딩하여 얻어지는 Z-파라미터와 게이트와 드레인 패드 커패시턴스를 제외한 핀치오프 된 cold-FET의 나머지 파라미터에 의해 모델링되는 Z-파라미터 사이의 잔차 오차를 최소화함으로써 HEMT의 모든 외인성 파라미터를 추출하는 기법을 제시한다. 제시된 기법을 사용하면 게이트와 드레인 모조패드의 추가적 제작 없이 게이트와 드레인 패드의 커패시턴스 값뿐 아니라 나머지 외인성 파라미터 값 모두를 성공적으로 추출할 수 있다.

• 대한기계학회논문집B
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• 제41권11호
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• pp.699-707
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• 2017

본 연구에서는 아홉 종류의 작동유체를 고려하여 저온 열원으로 구동되는 아임계 및 초월임계 유기 랭킨 사이클의 열역학적 성능 특성을 비교 해석한다. 터빈입구압력, 열원온도 및 작동유체가 열교환기 내 온도분포와 핀치포인트, 작동유체의 유량, 시스템 출력 및 열효율 등 시스템의 성능에 미치는 영향을 분석한다. 해석 결과는 작동유체의 압력이 아임계 영역에서 초임계 영역으로 높아지면 열교환기에서 열원과 작동유체 사이의 온도 불균일 정도가 감소하면서 시스템 출력이나 열효율 등은 증가하나 시스템의 단위출력당 터빈 크기는 작아짐을 보여준다.

• 한국재료학회지
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• 제17권6호
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• pp.308-312
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• 2007

Chromium oxide thin films have been deposited on silicon substrates using a tabletop 9kJ mathertyped plasma focus (PF) device. Before deposition, pinch behavior with gas pressure was observed. Strength of pinches was increased with increasing working pressure. Deposition was performed at room temperature as a function of working pressure between 50 and 1000 mTorr. Composition and surface morphology of the films were analyzed by Auger Electron Spectroscopy and Scanning Electron Microscope, respectively. Growth rates of the films were decreased with pressure. The oxide films were polycrystalline containing some impurities, Cu, Fe, C and revealed finer grain structure at lower pressure.