• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권3호
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• pp.99-104
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• 2002

lateral insulated gate bipolar transistors(LIGBTs) are extensively used in high voltage power IC application due to their low forward voltage drops. One of the main disadvantages of the LIGBT is its scow switching speed when compared to the LDMOSFET. And the LIGBT with reverse channel structure is lower current capability than the conventional LIGBT at the forward conduction mode. In this paper, the LIGBT which included p+ ring and p-channel gate is presented at the reverie channel structure. The presented LIGBT structure is proposed to suppress the latch up, efficiently and to improve the turn off time. It is shown to improve the current capability too. It is verified 2-D simulator, MEDICI. It is shown that the latch up current of new LIGBT is 10 times than that of the conventional LIGBT Additionally, it is shown that the turn off characteristics of the proposed LIGBT is i times than that of the conventional LIGBT. It is net presented the tail current of turn off characteristics at the proposed structure. And the presented LIGBT is not n+ buffer layer because it includes p channel gate and p+ ring.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1547-1549
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• 1996

The electrical and optical switching characteristics of gold-doped silicon p-i-n diodes have been investigated. The device shows a dark switching voltage of about 500 V. The switching voltage decreases rapidly when the illumination level is increased. The differential sensitivity of optical gating over linear region is $d(V_{Th}/V_{Tho})/dP_{Ph}$=0.25/uW. The turn-on delay time and the turn-on rise time decrease with increasing optical pulse power. The turn-off delay and the fall time are negligible.

• 산업기술연구
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• 제22권A호
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• pp.73-82
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• 2002

It is difficult to find the shortest paths using existing algorithms (Dijkstra, Floyd-Warshall algorithm, and etc) in high complex and large size real traffic networks The objective of this paper is to develop an evolution program to find the multiple shortest paths within reasonable time in these networks including turn-restrictions, U-turns, and etc.

• 임상간호연구
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• 제18권3호
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• pp.329-340
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• 2012

Purpose: This study was done to identify internal marketing activity, emotional labor and work-family conflict that influence turn-over in hospital nurses. Methods: Participants were 513 nurses from 2 general hospitals in Chung-nam and Gyeonggi Provinces, South Korea. Data were collected from September 1 to 30, 2011 using self-report questionnaires. Stepwise multiple regression was used to identify association between variables. Results: The mean score for internal marketing activity was $94.7{\pm}14.7$, emotional labor, $31.4{\pm}5.5$, work-family conflict, $19.6{\pm}4.1$, and turn-over, $13.7{\pm}3.4$. After adjusting for general characteristics, stepwise multiple regression showed that work-family conflict (${\beta}=.20$, p<.001), marketing activity (${\beta}=-.21$, p<.001), and emotional labor (${\beta}=.22$, p<.001) were associated with turn-over. These predictors accounted for 33% of variance in turn-over. Conclusion: The results of this study show that work-family conflict was the most influential predictor indicating a need for the development of strategies to reduce work-family conflict and emotional labor. At the same time internal marketing activity should be supported in the hospital by analyzing the needs for nurses. Also career development programs and mentor systems will be useful for effective manpower management and quality improvement of nursing services.

• Physical Therapy Rehabilitation Science
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• 제7권2호
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• pp.54-60
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• 2018

Objective: Persons with chronic stroke fall more often than healthy elderly individuals. The Timed Up and Go test (TUG) is used as a fall prediction tool, but only provides a result for the total measurement time. This study aimed to determine the optimal cut-off values for each of the 6 components of the TUG. Design: Retrospective study. Methods: Thirty persons with chronic stroke participated in the study. TUG evaluation was performed using a wearable miniaturized inertial sensor. Sensitivity, specificity, and predictive values were calculated using the Receiver Operating Characteristic (ROC) curve analysis for the measured values in each section. Optimal values for fall risk classification were determined. Logistic regression analysis was used to investigate the risk of future falls based on TUG. Results: The cut-off values of the 6 sections of the TUG were determined, as follows: sit-to-stand >2.00 seconds (p<0.05), forward gait >4.68 seconds (p<0.05), mid-turn >3.82 seconds (p<0.05), return gait >4.81 seconds (p<0.05), end-turn >2.95 seconds (p<0.05), and stand-to-sit >2.13 seconds (p<0.05). The risk of falling increased by 2.278 times when the mid-turn value was >3.82 seconds (p<0.05). Conclusions: The risk of falls increased by 2.28 times when the value of the mid-turn interval exceeded 3.82 seconds. Therefore, when interpreting TUG results, the predictive accuracy for falls will be higher when the measurement time for each section is analyzed, together with the total time for TUG.

• 전력전자학회논문지
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• 제3권4호
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• pp.418-425
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• 1998

본 논문에서는 위상각 제어에서 주어진 턴온 각에서 최대의 토크를 유지하기 위한 적절한 턴오프 각을 자기동조방식(self-tuning method)에 의해 결정하는 방식을 제안하였다. 엔코더에 의해 샘플링 시간(sampling time)동안 구해진 펄스 수는 바로 이전의 샘플링시간 동안 구해진 펄스 수와 비교하여 턴오프 각을 앞으로 또는 뒤로 이동한다. 이러한 과정을 되풀이함으로서 최대 토크를 발생하는 턴오프 각을 결정하게 된다. 실제 회로에서는 원 칩 마이크로프로세서에 의해 처리되었으며 실험을 통해 턴온 각이 변하더라도 자기동조방식에 의해 턴오프 각을 조정하면 빠른 속도가 유지됨을 보여 주었다.

• 대한교통학회지
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• 제21권6호
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• pp.89-99
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• 2003

회전제약(Turn Penalty and Prohibition)을 포함하는 방향성 그래프(Directed Graph)에서 두 지점(One-To-One)간 덩굴망(Vine)을 포함한 다수의 경로를 순차적으로 탐색하는 알고리즘(K-Shortest Path Algorithm)을 제안한다. 이를 위해 Yen이 제안한 다경로탐색알고리즘을 기반으로 교차로의 방향별 통행에서 발생되는 회전지체와 금지의 표현이 가능한 링크표지(Link-Labeled)탐색방식을 적용하는 기법을 개발한다. 사례연구를 통해 제안된 알고리즘은 교차로의 회전특성뿐만 아니라 U-Turn, P-Turn과 같은 덩굴망(Vine) 통행특성의 고려가 가능하며, 운전자의 인지비용(Perceived Cost)을 반영한 합리적인 대안경로(Reasonable Alternative Route)의 정보 제공 가능성을 입증했다.

• 산업공학
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• 제14권4호
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• pp.374-384
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• 2001

The objective of this paper is to design the dynamic route guidance system(DRGS) and develop a genetic algorithm(GA) for finding the multiple shortest paths in real traffic network. The proposed GA finds a collection of paths between source and destination considering turn-restrictions, U-turn, and P-turn that are genetically evolved until an acceptable solution is reached. This paper also shows the procedure to find the multiple shortest paths in traffic network of Seoul.

• 대한교통학회지
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• 제17권3호
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• pp.73-85
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• 1999

대도시에는 회전제한을 갖는 교차로가 다수 존재하며, 도로망에 있어서 최적경로를 계산할 때 회전제한을 고려해야 한다. 본 논문에서는 회전제한을 갖는 도로망에서 새로운 경로계획 방법을 제안하였다. 각 회전제한 노드에 대하여 U턴 혹은 P턴을 이용하여 대체경로를 미리 계산하고 이를 도로망 데이터베이스에 포함하는 도로망 모델을 제안하였다. 제안된 모델은 기존의 도로망 모델에서 회전제한을 표현하기 위하여 사용하던 가상 노드를 포함하지 않기 때문에 효율적이다. 제안된 모델을 이용하여 최적경로를 계산하기 위하여 새로운 최적경로 알고리즘을 제안하였다. 회전제한이 있는 노드에 대하여 마디를 정의하였으며, 이를 이용하여 대체경로의 비용과 타경로와의 비용을 비교할 수 있도록 하였다. 제안된 경로계획 방법은 회전제한이 존재하는 도로망에 대하여 최적경로를 고속으로 계산할 수 있는 효율적인 방법이다.

• 한국전문물리치료학회지
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• 제15권4호
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• pp.18-26
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• 2008

The present study was aimed at investigating the postural control ability of volleyball players with functional ankle instability. The subjects were 26 male volleyball players were divided into 2 groups (13 subjects with functional ankle instability and 13 subjects with ankle stability) who could evaluate Questionnaire. All the male participants were tested by a Balance Master System. This study were to measure of static balance ability, dynamic balance ability, motor function the difference between functional ankle instability group and control group. Ankle instability group and stable group in postural sway ($^{\circ}/sec$) on film surface with eye closed in modified clinical test sensory interaction on balance, and left unilateral stance with eye opened and closed were significantly different (p<.05). The ankle instability group and stable group in limit of stability were significantly different (p<.05). The ankle instability group and stable group in left/right rhythmic weight shirt were significantly different (p<.05). The ankle instability group and stable group in turn time (sec) & turn sway ($^{\circ}$) during step/quick turn and end sway ($^{\circ}/sec$) in tandem walk were significantly different (p<.05). This study showed that volleyball players with functional ankle in stability were effected postural control ability by static balance & dynamic balance ability. Further study is needed to measure various athletic with functional ankle instability for clinical application.