• Proceedings of the Korea Water Resources Association Conference
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• 2004.02a
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• pp.247-279
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• 2004

정부에서 지속적으로 추진중인 남북교류사업은 정부의 적극적인 지원으로 본격적으로 추진되고 있으며 교류의 폭도 점점 확대되고 있는 추세이다. 농업분야 또한 비료, 농약, 종자 등 간헐적으로 이루어지던 남북한 교류는 근본적이고 실질적인 지원 정책으로 전개될 것으로 예상된다. 따라서 본 연구에서는 남북한 농업분야 교류사업의 본격적인 추진에 대비하여 북한의 동해안지역에 대한 수자원 및 농업용수체계의 정확한 현황을 파악하고 문제점을 제시하여 이에 대한 개선방안을 모색하고자 한다. (중략)

• Journal of Scientific & Technological Knowledge Infrastructure
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• s.9
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• pp.102-111
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• 2002

과학기술 중시의 정책기조는 앞으로도 계속될 것이고, 과학기술을 통한 남북의 협력은 비정치적, 비사상적인 이유로 인해 어느 분야보다도 북한이 적극 나설 수 있으므로 그 가능성은 대단히 높다고 할 수 있다. 현재 남북경협은 단순 교역 방식의 위탁가공이 주류를 이루고 있으나 기술이전 등 기술협력 방식으로 발전이 요구되고 있다. IT를 중심으로 활발히 진행되어온 남북 교류는 과학기술 전반으로 기술 이전 및 협력 등 교류의 폭을 넓혀 나갈 것으로 기대된다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.421-422
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• 2011

본 논문에서는 직렬전압보상을 기반으로 한 직렬 전압 보상을 기반으로 한 자동 전압 조절기(AVR)가 제안된다. 제안된 AVR은 펄스 폭 변조 방식(PWM)의 교류 쵸퍼와 직렬 전압 보상을 위한 변압기로 구성된다. 제안된 AVR에 사용된 교류 쵸퍼는 commutation 문제가 해결되고 직접적인 교류전력변환이 이루어지기 때문에 따로 에너지를 저장할 소자가 필요없다. 따라서 크기와 가격이 줄어드는 장점이 있다. 직렬보상을 위한 변압기 때문에 교류 쵸퍼는 단지 보상을 위해 필요한 전압만 보상하면 되며, 따라서 스위치의 정격이 줄어든다. 제안된 AVR은 보상전압을 입력전압의 동상 또는 역상으로 만들어 줄 수 있기 때문에 입력전압의 증가 시 또는 감소시를 모두 보상할 수 있다. 실험을 통해 제안된 AVR이 입력전압의 증가 혹은 감소 조건에 대해 빠르게 보상해줌을 검증하였다.

• 전기의세계
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• v.25 no.4
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• pp.38-41
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• 1976

최근 전력용 반도체소자를 이용하여 전력의 변환과 제어를 하는 Power electronics가 많은 발전을 하고 있는데 이것을 가장 많이 이용하는 분야는 전동기의 가변속 구동이다. 이중에서 교류전동기의 구동을 위한 가변 주파수 제어장치의 구성을 보면 전압형 Inverter, 전류형 Inverter 및 Cycloconverter등에 의한 것으로 대별된다. 교류전동기의 가변주파수 제어는 농형유도전동기의 경우가 가장 많고 동기전동기는 약간 있는 정도이다. 여기서는 이러한 제어에 쓴이는 전압형 Inverter의 대표적인 회로와 최근에 개발된 펄스폭 제어 Inverter의 동작 원리 및 특징등에 대하여 소개하고저 한다.

• Cartoon and Animation Studies
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• s.36
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• pp.619-641
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• 2014

Animation is an important tool to establish the identity of mutually related countries, as cultural contents with the economic value. That is, it is necessary that the Korean animation should extend the previous boundary of exchange, for the status of representative cultural industry in the 21st century global market. Especially, to overcome the regionally prejudiced and unbalanced cultural exchange, the possibility of extension with Czech animation, which has not had an active exchange with Korea, will be considered and the efficient method will be proposed. The Czech Republic is geopolitically located in the center of Europe and its infrastructure like industrial construction, investment environment, human resources is outstanding among Visegrad Group. The Czech Republic has a remarkable cultural border-crossing phenomenon, and as a complex country of cultural and religious characteristics of eastern and western European, it is a powerful nation leading Central Europe. Therefore, the animation exchange of Czech and Korea is valuable in culture and economy of both nations. Through such an animation exchange of both nations, not only Korean animation secures the diversity of exchange but also insignificant cultural exchange after formal establishment of diplomatic relations in 1990, will be revitalized and international firm relationship of both nations will be established. Therefore, as an activation plan or cultural exchange of Korea and the Czech Republic, concrete plan like Stop Motion Animation Workshop is proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.5
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• pp.505-518
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• 1987

In this paper, the 2-level and 3-level types of PWM technique have been analyzed, and a multiprocessor has been designed as controller for these two types of PWM inverters. Designed multiprocessor employing a hierarchical structure of a SUPERVISORY PROCESSOR which interconnects three LOCAL PROCESSOR through a common memory technique has showed as elaborate digital control characteristic. Using this multiprocessor configuration the system could gain a great degree of freedom in change of software. Also software was simpler than a single processor configuration.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.5
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• pp.462-473
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• 1999

This paper addresses the current measurement issue of all digital field oriented control of ac motors. The p paper focuses on the effect of low-pass filter and also on the sampling of the fundamental component of the m motor current. The low-pass filter, which suppresses the switching noise of the motor current, introduces v variable phase delay according to the current ripple frequency. It is shown that the current sampling error c consists of the fundamental component and high frL'quency ripple components. In this paper, the dependency of t this current sampling e$\pi$or on the reference voltage vector is investigated analytically and a sampling technique i is proposed to minimize the error. The work is based on the three phase symmetry pulse width modulation l inverter driving an induction machine. With this technique, the bandwidth of current regulator can be extended t to the limit given by the switching frequency of the inverter and more precise torque regulation is possible.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.3
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• pp.292-298
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• 2003

Most of the three phase inverters for adjustable speed drive of AC machines are equipped with two or three current sensors for measurement of three phase current. One method to reduce the number of current sensors is that single current sensor measures the DC link current, then three phase current is reconstructed using the measured value and the switching status. To improve the measurement accuracy, switching state should be maintained for more than minimum switching time. Many papers have been published, which focused on the readjustment of pulse width and compensation of voltage distortion. Those methods are suitable for space vector modulation. But there are some difficulties in applying these methods to carrier-based PWM which is widely used in industry. In this paper, new current measurement method and voltage compensation method are proposed which are suitable for carrier-based PWM, then, the validity of proposed method is confirmed through experiment.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.71-79
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• 2012

In Japan, the number of late night animations has increased from the 2000s. In 2010, it exceeded the number of other Japanese animations playing between 6:00 to 23:00 (pre-late night). People watching these late night animations were mostly adolescents or older. Late night animations involve various niche themes, however, the ranges of the main characters' actions of these stories were narrower and more limited compared to the pre-late night animations. The causes for these differences in the scales of the settings were found by comparing the late night and pre-late night animations. The most popular animations from these two time slots were used in the analysis. Firstly, the main characters' ways of approaching their goals were analyzed. Secondly, the settings and directions that the main characters used were analyzed. Lastly, the main characters' degree of interactions with other people was analyzed. As a result of the analysis, the main characters' goals from the late night animations were often found to be commonplace and they tended to achieve their goals by very realistic means. In addition to that, the stories of these main characters revolved around small and familiar communities. Thus, their connections with people were comparatively smaller than those of pre-late night animations and were based upon shared interests. In other words, the differences in the scales of the settings between the two types of animations resulted from the stories of the late night animations revolving mainly around reality, communities, and relationships within the communities.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1478-1479
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• 2007

본 연구는 교류전압 인가시 제조공기(I-Air)의 온도(T)의 변화($+10[^{\circ}C{\sim}-30[^{\circ}C]$)에 따른 절연특성을 구명하였다. 절연특성은 GIS모의 챔버 주입 압력(P)과 비례하는 특성을 보였으나 T가 저하되면서 그 절연특성이 감소하는 경향을 보이지 않고 오히려 증가하는 구간이 일부 존재 하였다. 그리고 챔버내 P의 크기가 클수록 T저하에 따른 P감소율이 더 커졌으며, 절연파괴전압($V_B$)감소폭은 8[atm]에서 가장 큰 변화를 보였으며 4, 6, 2기압 순으로 변화를 보였다.