• 제목/요약/키워드: Time shift

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박막트랜지스터의 병렬형 가역과 비가역 문턱전압 이동에 대한 모델링 (Modeling of Reversible and Irreversible Threshold Voltage Shift in Thin-film Transistors)

  • 정태호
    • 한국전기전자재료학회논문지
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    • 제29권7호
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    • pp.387-393
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    • 2016
  • Threshold voltage shift has been observed from many thin-film transistors (TFTs) and the time evolution of the shift can be modeled as the stretched-exponential and -hyperbola function. These analytic models are derived from the kinetic equation for defect-creation or charge-trapping and the equation consists of only reversible reactions. In reality TFT's a shift is permanent due to an irreversible reaction and, as a result, it is reasonable to consider that both reversible and irreversible reactions exist in a TFT. In this paper the case when both reactions exist in parallel and make a combined threshold voltage shift is modeled and simulated. The results show that a combined threshold voltage shift observed from a TFT may agrees with the analytic models and, thus, the analytic models don't guarantee whether the cause of the shift is defection-creation or charge-trapping.

자동변속장치의 간접식 과도토오크 제어기 설계에 관한 연구 (A Study on the Design of an Indirect Shift Transient Torque Controller for an Automatic Power Transmission System)

  • 정헌술;이교일
    • 한국자동차공학회논문집
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    • 제2권5호
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    • pp.110-120
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    • 1994
  • Due to the increasing demands in comfortable drivability, most motor companies are developing their own unique shift controller to suppress the shift shock induced by gear change. For a typical automatic transmission system, the dynamic constraints of friction clutch was clarified for efficient program development and major factors effecting the shift transient was confirmed by simulation study. The MIMO LQG/LTR controller was designed to control the turbine and corresponding gear speed. By establishing the control strategy recalling transient response during shift the speed controller mentioned above was used as an indirect torque controller. Consequently a new concept for a systematic design method of shift controller applicable to wide-varying systems was suggested which is time efficient and cost efficient saving a lot of experimental study.

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근로시간 및 교대근무편성의 문제점과 개선방향 (Problems of Working Hours and Shift Work Systems, and Propsed Methods for Their Improvement)

  • 서유진;;박영만;문세근
    • 대한인간공학회지
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    • 제22권3호
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    • pp.13-26
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    • 2003
  • The purpose of this study is to investigate the present conditions of the night work and shift work systems in the heavy chemical industrial complexes found in Changwon, Masan, and Chinhae. Korea. We will attempt to define and classify their problems; and to discover further ways to improve their systems. Fifty production factories were carefully selected as the subjects for this study. The shift systems were classified into five categories. The consecutive night shifts were long in almost all cases with 6 days (36 factories) and 7 days (13 factories). It was found that the night work of about] 2 hours continues for a long period in the weekly rotation full-day shift systems and the night-including non-full-day shift systems, and there was no holiday during a shift cycle in the continuous full-day shift systems. The work time in most shift systems was longer than the 44-hours/week permitted by Korean law. Considering the characteristics of these various types of shift systems, the most essential thing to reduce the shift workers' work load may be to shorten their working hours and improve the schedule of shift systems. It is highly recommended as a fundamental solution. to reduce the portal-to-portal hours from 12 to 8 in the night-including non-full-day shift systems and the weekly rotation full-day shift systems, and at least to employ a 4-team 3-shift system in the continuous full-day shift systems. In addition to this, it should from now on be taken as a goal to restructure the types of shift systems by taking such measures as avoiding continuous night work if possible, providing sufficient off-duty intervals both before and after night shift, providing increased opportunities for workers to nap during night work. and increasing the number of holidays.

조셉 콘라드의 『로드 짐』에서의 시간 전도 기법 (Time-Shift technique in Joseph Conrad's Lord Jim)

  • 박선화
    • 영미문화
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    • 제9권1호
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    • pp.221-237
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    • 2009
  • This paper analyzes the time-shift technique in Joseph Conrad's Lord Jim. Conrad's manipulation of time in this novel is based on his aspiration for how 'to make you see,' which he believes is completed through the harmony form and substance in his works. So Conrad applies this technique which was used earlier by some writers such as Laurence Sterne to his Lord Jim to show its theme more effectively. In Lord Jim, the story consists of two parts; first, Jim jumps from a ship called the Patna and is deprived of his navigation certificate. Secondly, he wins the people's respect in Patusan in which his past related to the Patna remains hidden, but he faces his death by taking responsibility for the death of the chief's son in the island. These events in Lord Jim are not described in chronological order; that is, some events are depicted with the time-shift technique using flashback, association, or fragmentary memory to accelerate the speed of stories as well as to offer the actuality of the events. With this structure, the themes of Jim's story have something to do with his heroic actions and failures. Jim wants to be a hero and after failures he struggles to redeem himself only to fail. In particular, Jim's jump from the Patna is emphasized through the time-shift and it shows there is something incomprehensible in his action. Therefore, Conrad reveals in Lord Jim that Jim is one of us who not only are imperfect but also have the weaknesses inside that can unexpectedly emerge in an instant.

교대근무 경찰의 1일 보행수, 활동량 및 활동계수의 평가 (Assessment of Daily Steps, Physical Activities and Activity Coefficient of Policemen who Do Shift-Work)

  • 이선희;박지선;김은경
    • Journal of Nutrition and Health
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    • 제40권6호
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    • pp.576-583
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    • 2007
  • The purpose of this study was to assess the daily steps, physical activities and activity coefficient of policemen (average age: 31.5 ${\pm}$ 5.1 years) who do shift work. Body weight, height and daily steps were measured and one-day activity diary was collected by interviewing with policemen. Average height, body weight, BMI, body fat (%) and muscles (%) of subjects were 173.1 ${\pm}$ 5.2 cm, 73.7 ${\pm}$ 9.7 kg, 24,6 $kg/m^{2}$, 15.5 ${\pm}$ 1.9% and 37.3 ${\pm}$ 5.8%, respectively. The average daily numbers of steps were found to be 9,812 steps/day on day shift duty and 10,888 steps/day on night shift duty and 6,551 steps/day on holiday duty. Hourly step rates on day shift, night shift and holiday came to 1946 steps/hr, 2,130 steps/hr and 1,318 steps/hr, respectively. Activity coefficient (1.75) in night shift of the subjects was the highest and activity coefficient (1.52) in day shift was significantly higher than that (1.31) in holiday (p < 0.05). The rate of expending time for very light activity in holiday (91.5%) was significantly higher than that (70.0%) in night shift. The muscle mass (kg, %) had significantly positive relationship with daily steps in day shift (r = 0.592, r = 0.632) and night shift (r = 0.550, r = 0.503). Triceps skinfold thickness was negatively correlated with daily steps in day shift (r = -0.366, p < 0.05). There were remarkable differences in physical activities and sleeping hours depending on shift works of policemen. In the case of night shift work, sleeping hours was the lowest and activity coefficient was the highest among day shift, night shift and holiday. These results suggest that energy requirements of policemen should be differentiated according to shift work duty.

가려짐에 강인한 실시간 얼굴추적 방 법 (Real-time Face Tracking Method Robust to Occlusion)

  • 이준환;정현조;유지상
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2016년도 하계학술대회
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    • pp.25-28
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    • 2016
  • 본 논문에서는 실시간 얼굴 추적을 위하여 기존의 CamShift 알고리즘의 단점을 보완한 새로운 CamShift 알고리즘을 제안한다. 배경 내 추적 객체와 색상이 유사한 객체가 존재할 경우 기존 CamShift 알고리즘은 불안정한 추적을 보여준다. 이러한 문제점을 화소 단위로 거리정보를 획득할 수 있는 Kinect 의 깊이 정보와 HSV 색공간 기반의 피부색 후보영역을 추출하는 Skin Detection 알고리즘을 이용하여 색상분포만 이용하는 기존의 CamShift 의 단점을 보완한다. 또한 추적하던 객체가 사라지거나 가려짐이 발생할 경우에도 다시 추적할 수 있는 특징점 기반의 매칭 알고리즘을 통하여 차폐영역에 강인한 특성을 가지게 한다. 이러한 향상된 CamShift 알고리즘을 사람의 얼굴 추적에 적용함으로써 다양한 분야에 활용 가능한 강인한 얼굴추적 알고리즘을 제안하고자 한다. 실험결과 제안하는 알고리즘은 기존의 추적 알고리즘인 TLD 보다 월등히 빠른 처리속도와 더 우수한 추적성능을 보여주었고, CamShift 보다 조금 느리지만 기존의 CamShift 가 가지고 있는 문제점들을 해결하였다.

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유기박막 트랜지스터에서 문턱전압 이동의 모델링 및 시뮬레이션 (Modeling and Simulation of Threshold Voltage Shift in Organic Thin-film Transistors)

  • 정태호
    • 한국전기전자재료학회논문지
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    • 제26권2호
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    • pp.92-97
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    • 2013
  • In this paper the author proposes a method of implementing a numerical model for threshold voltage ($V_{th}$) shift in organic thin-film transistors (OTFTs) into SPICE tools. $V_{th}$ shift is first numerically modeled by dividing the shift into sequentially ordered groups. The model is then used to derive a simulations model which takes into simulation parameters and calculation complexity. Finally, the numerical and simulation models are implemented in AIM-SPICE. The SPICE simulation results agree well with the $V_{th}$ shift obtained from an OTFT fabricated without any optimization. The proposed method is also used to implement the stretched-exponential time dependent $V_{th}$ shift in AIM-SPICE and the results show the proposed method is applicable to various types of $V_{th}$ shifts.

액티그래프를 이용한 항공관제사의 수면/각성행동 (Sleep-wake Behavior of Air Traffic Controllers using Wrist Actigraph)

  • 서유진
    • 대한인간공학회지
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    • 제29권3호
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    • pp.337-345
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    • 2010
  • The purpose of this study was to investigate the effects of sleep/wake behavior for shiftwork in air traffic controllers (ATCs) using wrist actigraph for ten workers on a continuous full-day three-team three-shift system of forward rotation including on-duty and off-duty periods. The wrist actigraph data were recorded for three days (one shift cycle) for each subject. The mean activity counts during an on-duty period progressively increased from the night, the swing, to the morning shifts. The doze length during on-duty periods showed decreases in the morning and swing shifts as compared to the night shift. Total sleep time (TST) and sleep efficiency (SE) during off-duty periods increased in the morning-1 and swing-night shift compared to the morning-2 shift. Finally, I discussed the role of doze-taking during the burden on night shift ATCs.

DEVELOPMENT OF DCT VEHICLE PERFORMANCE SIMULATOR TO EVALUATE SHIFT FORCE AND TORQUE INTERRUPTION

  • Park, S.J.;Ryu, W.S.;Song, J.G.;Kim, H.S.;Hwang, S.H.
    • International Journal of Automotive Technology
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    • 제7권2호
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    • pp.161-166
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    • 2006
  • This paper presents shift characteristics of a dual clutch transmission(DCT). To obtain the shift force, dynamic models of the DCT are constructed by using MATLAB/Simulink and considering the rotational inertia of every component and the target pre-select time. Dynamic models of the shift and clutch actuators are derived based on the experimental results of the dynamic characteristics test. Based on the dynamic model of the DCT synchronizer, control actuator and vehicle model, a DCT vehicle performance simulator is developed. Using the simulator, the shift force and speed of the relevant shafts are obtained. In addition, the torque and acceleration of actuators are calculated during the shift process by considering the engaging and disengaging dynamics of the two clutches. It is observed from the performance simulator that uninterrupted torque can be transmitted by proper control of the two clutches.

순환천이변조 주파수도약대역확산/시분할다중접속 시스템의 성능 개선에 관한 연구 (Study on Performance Enhancement for a Cyclic Code Shift Keying Frequency Hopping Spread Spectrum/Time Division Multiple Access System)

  • 김은철;김승춘;이형근
    • 전기전자학회논문지
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    • 제16권1호
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    • pp.51-55
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    • 2012
  • 본 논문에서는 순환천이변조 (CCSK: cyclic code shift keying) 시퀀스로 삼진 시퀀스를 적용하는 것을 제안하였다. 그리고 순환천이변조를 적용한 주파수도약대역확산/시분할다중접속 (FHSS/TDMA: frequency hopping spread spectrum/time division multiple access) 시스템에서 성능을 모의실험 하였다. 실험에서 무선 채널은 레일레이(Rayleigh) 페이딩 채널로 모델링하였다. 모의 실험 결과로부터 순환천이변조 시퀀스로 무작위 시퀀스를 사용한 시스템보다 삼진 시퀀스를 적용한 시스템이 더 높은 성능을 보이는 것이 증명되었다.