• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.117-125
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• 1998

In this paper, in order to develop the three phase GTO CSI of high efficiency 1M drive with low loss commutation and snubber energy, we studied the energy recovery circuit to recover stored energy in clamping capacitor and DC link inductor(VCC-l and VCC-2), and snubber capacitor(VCC-3). By using an induction motor as the load of inverter, experimental results show that dissipated DC power is decreased and capacitor voltage Vc is effectively suppressed by VCC-2 and VCC-3 system, and the validity of VCC-3 system with low loss commutation and snubber energy is proofed.roofed.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.378-380
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• 1996

This paper presents the novel control and analysis of GTO-CSC. The control method is based on the linearization of an optimal modulation strategy so that the turn-on-periods of the GTO switches can be computed in real-time for any specified modulation index. These PWM patterns allow to produce minimal ac line current low order harmonics of ac line current and low switchings. Finally, the computer simulation results are presented to verify the theoretical analysis.

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.270-271
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• 1984

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.4
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• pp.323-330
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• 2017

Knee sleeve has been used for prevention of sport injuries as well as rehabilitation. To investigate prevention of sport injuries of knee sleeve, it is important to evaluate balance associated with proprioception. The aim of this study was to evaluate the effects of a knee sleeve with a pad that stimulate to golgi tendon organ (GTO_PAD) on proprioception and balance ability. Five healthy males were participated for the study. They were asked to reenact target angle with Biodex and perform one leg standing with knee sleeve and knee sleeve with GTO_PAD. There was no significant difference in %Target angle, but the value of %Target angle was higher in subjects wearing knee sleeve with GTO_PAD than only knee sleeve, except for one subject. During one leg standing, time duration was increased in subjects wearing knee sleeve with GTO_PAD. The length of center of pressure in x-axis (COPx) and COP in y-axis (COPy) were decreased when wearing knee sleeve with GTO_PAD (COPx : $162.06{\pm}58.99mm$ in knee sleeve vs. $149.03{\pm}45.30mm$ in knee sleeve with GTO_PAD, COPy : $310.79{\pm}115.89mm$ in knee sleeve, $291.57{\pm}76.53mm$ in knee sleeve with GTO_PAD). There was significant differences in INI_transition, steady, and LAT_transition phase (all, p < 0.05). These findings support that wearing knee sleeve with GTO_PAD might enhance proprioception and balance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.153-155
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• 2016

국내 컨테이너 터미널을 대상으로 DEA-Malmquist 분석을 이용하여 운영사의 특성별 효율성을 비교하여 분석한다. 운영사는 GTO, Carrier, Domestic으로 구분하여 각 운영적 특성에 따라 시사점 및 결론을 도출한다.

• Journal of Korea Port Economic Association
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• v.28 no.1
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• pp.159-178
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• 2012

Recently, Global network expansion strategy of GTOs(Global Terminal Operator) coupled with each country's port policy, plays huge role for the evolution of modern container port. The Chinese ports can be regarded as the major markets to the GTOs. However, there are scant of researches for finding the key success factors of GTOs' strategies when they consider to invest in overseas. In this respect, the aims of this study were to draw out the evaluation variables for successful investment strategies of GTOs, and to calculate the selected target ports. The 14 variables are selected including the variable named 'development potentiality of a port' through literature reviews. Using the Factor Analysis (FA) based on selected variables, four principal factors were extracted such as 'ability for port operating and cargo generating', 'the trade route and volume', 'the calling potentiality for large vessels' and 'the possibility of utilization of existing infrastructure'. In addition, the weights of factors and variables are evaluated through Fuzzy AHP method. As a result, 'ability for port operating and cargo generating' is chosen as the most important factor among principal factors as scored 0.343, and 'the development potentiality of a port' (0.107) is represented as the most important variable among 14 detailed variables. In overall, from the Global Terminal Operator's point of view, Shanghai is ranked as most suitable port for operating new terminal among the top 5 Chinese ports.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.35.3-36
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• 2020

The Time Domain Field is one of the future GTO program fields of JWST(JWST/GTO TDS), surveying about 14' diameter field at the North Eliptical Pole(NEP) with NIRCam/NIRISS. As a part of the multi-wavelength study of the field, we have obtained SCUBA-2 850㎛ mapping which reaches a depth of σrms = 0.9mJy/beam and detect 93 sources at S/N > 3.5 ― which are expected to be highly star-forming (SFR>400M◉/yr) galaxies at z ≳ 1.5-4 and pinpoint the location at <0. " 1 accuracy of 68 sub-mm sources by identifying VLA 3GHz radio counterparts. In this talk, we will introduce the SCUBA-2 JWST/GTO TDS project and the newly discovered sub-mm sources in this field.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.291-294
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• 1990

Fuel cell system needs DC-AC conversion inverter system because its output is DC. And the inverter system can be operated not only in stand-alone load but also in interactive mode in interactive mode, it is necessary to control active-reactive power of inverter and to synchronize inverter output voltage to power line voltage. In this paper, a 12 phase multiple VSI type GTO inverter system for fuel cell is described. Synchronization between power line voltage phase and inverter output voltage phase, and reduction of harmonics in the output voltage phase are the purpose of this inverter system. This control algorithm for the system is realized by the software method utilizing 8031AH 8bit Microprocessor.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2043-2046
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• 1997

GTO 소자의 최소 턴온 시간(minimum turn-on time, Tmin)때문에 발생된 지령전압 오차를 보상하는 기법을 제안한다. 공간백터전압$(V_1)$의 턴온시간이 Tmin보다 작을 경우에는 전압오차를 PI 제어기로 보상한다. 또한, 지령전압벡터의 크기가 특정한 값(Vmin)보다 작은 경우, 영벡터(zero vector)가 PWM 추기에서 중간에 매치가 되도록 스위칭 순서를 바꿔준다. 시뮬레이션을 통해 이러한 지령전압 오차의 보상으로 펄스 누락(pulse dropping) 영역에서 출력전압의 대칭성이 향상되고 고조파 함유량이 감소한다는 사실을 보인다.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.406-408
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• 1994

A static VAR compensator using 100kVA three-level GTO voltage source inverter is presented for high voltage/high power applications. The phase angle of the invertor is controlled so as to compensate the reactive power of some load. The paper deals with the following topics; system description, circuit DQ modelling, main controller, power circuit.