• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권1호
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• pp.42-46
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• 2012

With the development of industry, more large-scale non-linear loads are added to existing power systems and they cause the serious power quality (PQ) problems to the nearby sensitive installations more and more. To protect the important loads and mitigate the impact of PQ disturbances on them, various compensating devices are installed. One of the most important control skills used in the compensating equipment at the load side is how fast they can recognize or detect the discontinuous abnormal PQ events from the normal voltage signal. This paper deals with two estimation methods for the fast detection and tracking of general PQ disturbances: Teager Energy Operator (TEO), which is a non-linear operator and used for a short time energy calculation, and Kalman Filter (KF), which is one of the most universally used estimation techniques. And it is also shown how to apply the TEO and the KF to detect the PQ disturbances such as voltage sag, swell, interruption, harmonics and voltage fluctuation.

• 방사선산업학회지
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• 제6권1호
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• pp.17-21
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• 2012

The effects of gamma ray or electron beam irradiation on herbaceous medicinal plants were investigated in terms of the composition of volatile constituents using the aerial parts or leaves of Artemisia princeps Pamp. cv. Ganghwayakssuk and Artemisia argyi cvs. Namhaeyakssuk and Hwanghaessuk. The composition of volatile constituents in leaves was clearly distinguishable among the three Artemisia cultivars. However, the relative proportions of the major volatile constituents such as 1,8-cineole, ${\alpha}$-pinene, camphene, santolina triene, and artemesia triene, were similarly changed in two or three cultivars by gamma ray or electron beam irradiation. In particular, the proportion of 1,8-cineole was increased up to 1.29- to 1.71-fold in the three cultivars after irradiation with gamma ray. These results suggest that gamma ray or electron beam irradiation can be applied to modulate the composition of volatile constituents in the leaves of Artemisia plants.

• 생명과학회지
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• 제29권8호
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• pp.922-940
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• 2019

비만은 에너지 섭취와 소비의 불균형으로 인해 유발되는 비정상적인 지방 축적으로, 근래에 다양한 만성질환을 초래하는 주요 국제 보건 문제로 부상하였다. 이러한 이유로, 비만 문제에 대한 여러 해결책들이 제시되고 있다. 에너지를 저장하며 내분비 작용을 하는 백색 지방과 달리 열을 생성하여 에너지를 발산하는 두 종류의 지방조직인 갈색 지방과 베이지색 지방이 성인에 존재하며 외부 자극에 의해 유도될 수 있다는 것이 밝혀진 이래로, 이들은 비만 치료의 유망한 표적으로서 각광받고 있다. 이러한 외부 자극 중, 인간 장관계에서 인간과 공존하는 장내 미생물총은 다양한 대사 작용에 참여하며, 이를 조절하는 것이 여러 대사 질환의 치료에 유력한 작용을 할 것으로 보인다. 따라서, 다양한 연구에서 항비만 치료가 장내 미생물 환경 전환이나 갈색 지방 조직 활성화에 미치는 영향에 초점을 맞추고 있다. 본 총설에서는 비만과 체중 증가, 대사 질환을 해소하는 것으로 알려진 자극과, 장내 미생물총의 변화나 갈색지방의 활성화를 야기하는 자극과, 이 자극들과 장내 미생물총의 조작, 지방조직의 갈색화 사이에서 알려져 있거나 있을 수 있는 상관관계를 중점적으로 다루고자 한다.

• 대한방사성의약품학회지
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• 제5권2호
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• pp.79-82
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• 2019

⁶¹Cu is a promising PET radiometal having favorable nuclear decay characteristics with appropriate half-life of 3.3 h. Owing its promising capabilities in radiopharmaceutical chemistry and its chemical similarities with its isotopes ⁶⁴Cu and ⁶⁷Cu, in this work we have tried to optimize the production and separation conditions of ⁶¹Cu. ⁶¹Cu was produced via (p, x) reaction with natural nickel which was electroplated on the high purity silver coated copper backing target holder. The optimization of target electrodeposition, beam energy and current modulation, target dissolution and separation were optimized in this study. Preliminary studies show that ⁶¹Cu was successfully produced and separated which can be further extended for the production of ⁶⁴Cu and ⁶⁷Cu.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.189-199
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• 2016

Fast neutrons with a broad energy spectrum, with which it is possible to evaluate nuclear data for various research fields such as medical applications and the development of fusion reactors, can be generated by irradiating proton beams on target materials such as beryllium. To generate short-pulse proton beam, we adopted a deflector and slit system. In a simple deflector with slit system, most of the proton beam is blocked by the slit, especially when the beam pulse width is short. Therefore, the available beam current is very low, which results in low neutron flux. In this study, we proposed beam modulation using a buncher cavity to increase the available beam current. The ideal field pattern for the buncher cavity is sawtooth. To make the field pattern similar to a sawtooth waveform, a multiharmonic buncher was adopted. The design process for the multiharmonic buncher includes a beam dynamics calculation and three-dimensional electromagnetic simulation. In addition to the system design for pulsed proton generation, a test bench with a microwave ion source is under preparation to test the performance of the system. The design study results concerning the pulsed proton beam generation and the test bench preparation with some preliminary test results are presented in this paper.

• 한국전기전자재료학회논문지
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• 제36권1호
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• pp.1-9
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• 2023

According to the recent global warming, it is necessary to use energy efficiently together with eco-friendly energy. The development of alternative technologies is requisite for managing the current energy and climate crises. In this regard, "smart windows," which can control solar radiation, can be used to mitigate energy demands. Electrochromic devices (ECDs) effectively control the amount of solar energy reaching commercial and other living areas and maintain climate conditions via color modulation in response to small external stimuli, such as temperature and light irradiation. However, the performance and the stability of ECDs depend on the state of the electrolyte and sealing of the device. To resolve the aforementioned issues, an ECD was manufactured by using a poly (methyl methacrylate) (PMMA)-based gel polymer electrolyte (GPE), and a laminating method was used to adequately seal the ECD. The concentrations of PMMA, acetonitrile (ACN), and ferrocene (Fc) were controlled to optimize the composition of the GPE to achieve an enhanced electrochromic performance. The fabricated GPE-based ECD afforded high optical contrast (~81.92%), with high electrochromic stability up to 10,000 cycles. Moreover, the lamination method employing the GPE could be used to fabricate large-area ECDs.

• Journal of Astronomy and Space Sciences
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• 제11권1호
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• pp.1-12
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• 1994

The structure of the magnetic funnel element in the intermediate polar is considered in terms of an important site for the X-ray absorption and the reemission of the X-ray as the optical light. In this paper the column density and the optical depth vary with the filling factor, which is introduced to characterize the structure of matter in the magnetic funnel element. The results of the energy dependence of the X-ray spectrum and the modulation depth of the X-ray light curve are discussed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.622-625
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• 1999

This paper introduces a novel zero-voltage switching (ZVS)) pulse width modulation (PWM) active clamping dc-to-dc boost converter. This technique presents ZVS commutation without additional voltage stress and a significant increase in the circulating reactive energy throughout the converter. Therefore, all of the losses for the switches are minimized, and high power density system can be realized. The characteristics are verified through simulation and experimental results.

• Journal of the Optical Society of Korea
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• 제1권1호
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• pp.44-47
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• 1997

The integration of a GaAs/AlGaAs multi-quantum well electroabsorption modulator and a tapered waveguide vertical direction optical interconnect has been performed without the complicated regrowth process. Zn impurity-induced layer disordering of MQW layer is used to achieve the energy transfer between SQW and MQW regions. Light coupled into a SQW region was transferred to an MQW region and an intensity modulation of 10 dB extinction ratio was demonstrated.

• 한국광학회지
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• 제2권1호
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• pp.13-19
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• 1991

광섬유에서의 자기위상변조 효과와 회절격자의 지연선 특성을 이용하여 Nd:YAG 레이저에서 얻은 1.319$\mu\textrm{m}$ 파장의 모드록킹된 반치폭 약 80 ps의 고출력 2.1ps까지 압축하였다.