• 전기학회논문지P
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• 제58권4호
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• pp.397-403
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• 2009

In this paper, an exciter current control of a synchronous generator for ships using a compound type digital automatic voltage regulator (DVAR) in order to provide a constant output voltage of the generator is presented. The compound type DAVR is composed of a controller part to adjust output voltage and an power source unit to supply power to the exciter. The controller part, which generates the PWM switching pattern via the PI controller, drives a power MOSFET for bypass to limit the SG's exciter current. The power source unit part is parallel connected to an output terminal of the generator through a reactor and a power CT. The residual magnetic flux of SG provides exciter current to the exciter through the reactor during the initial running or no load state and load current supplies field current to the exciter through the power CT during loading state. This paper confirmed an experiment to verify the validity of compound type DAVR system for controlling output voltage of synchronous generator.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.459-462
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• 2017

In this study, we design, model, and analyze a compound generator that combines the axial flux permanent magnet (AFPM,) and radial flux permanent magnet (RFPM), which is expected to increase power generation by allowing the magnets to be placed on the upper, lower, left, and right sides of the same-sized generator. Through the design, modelling, and analysis of AFPM and RFPM compound generators, the generator load evaluation results rated output of 500.25 W and efficiency of 87.60%, respectively, at a rated speed of 600 rpm. By employing this complex generation system,these findings are expected to contribute to the activation of a small power generation system.

• Macromolecular Research
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• 제14권3호
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• pp.300-305
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• 2006

The chemical structure of a semi-aromatic polyimide-I, which was prepared by the chemical imidization of cyclopentanetetracarboxylic dianhydride and 2,2-bis(4-aminophenyl)hexafluoropropane, was characterized by $^{13}C-NMR$ spectroscopy. The chemically imidized polyimide-I was used for the preparation of a photosensitive polyimide (PSPI) through the addition of benzophenone and benzophenone oxime hexamethylene diurethane (BOHD), a photobase generator containing oxime-urethane groups. The polyimide-I film containing benzophenone and BOHD was not soluble in 2.38 wt% tetrabutylammonium hydroxide solution in $H_2O$. However, it became soluble following irradiation with 310 nm UV light. A positive tone image with a resolution of $5{\mu}m$ was obtained with this PSPI, having sensitivity($D_c$) of $1.2J/cm^2$ and contrast(${\gamma}_p$) of 1.08. Thus, a polyimide, which is not intrinsically photosensitive, can become photosensitive through the addition of a photobase generator containing oxime-urethane groups as a photosensitive compound.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1983년도 하계학술회의강연.논문초록집
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• pp.85-87
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• 1983

• 대한전기학회논문지
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• 제33권11호
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• pp.425-432
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• 1984

This paper is to propse a new self-excitation method of synchronous generator. Instead of conventional exciter of synchronous generator, the additional winding which is arranged in addition to the armature winding, is used in this generator. The output terminal of the additional winding is connected to a capacitor and to a full wave rectifier in series. In this configuration, one source double excitation which is composed of capacitor-self-excitation by lead urrent and direct current excitation by rectifier, is induced. The result is that` The excetation efficency is improved greatly and output waveform is improved also. In three-phase synchronous generator using the new method of the one source double excitation, voltage element (shunt characteristics) and current element (series characteristics)are compounded in scalar by adapting star-point-open-rectifier system. The result is as following` The effect of load power factor angle on voltage regulation is reduced greatly, compound characteristics is become manifold by controlling capacity of capacitor, and transient response is improved.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.287-292
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• 2002

This paper presents a reverse engineering method for compound surfaces using vision system. A CNC machining center is used as a measuring station, which is equipped with slit beam generator and vision probe. Since obtained data using slit beam or laser scanner may have much data loss along the edge of compound surfaces, an algorithm is presented in this study to recover missing geometric data at such region. First, b-spline interpolation is applied to extract edge information of the surface, and as a next step, b-spline approximation is applied to recover the missing geometric data. Finally, b-spline skinning method is applied to regenerate the surface information. Appropriate simulation and experimental works are preformed to very the effectiveness of the proposed methods.

• 조명전기설비학회논문지
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• 제16권6호
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• pp.119-125
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• 2002

무성방전형 오존발생장치에서 고농도의 오존을 발생시키기 위해서는 방전공간의 온도를 낮게 유지시켜주는 것이 중요하다. 이때, 방전공간에서 발생된 열을 외부로 전달하기 위한 유전체장벽과 전극간의 접착물질과 접착방법은 전기적, 열적 관점에서 볼 때 방전에 큰 영향을 미치게 된다. 따라서 접착물질과 접착방법은 오존발생에 중요한 변수가 될 수 있다. 본 연구는 접착물질과 방법이 오존발생에 미치는 영향을 조사한 실험적인 결과이다. 접착물질의 종류로는 방열재료로 사용되는 실리콘 화합물질, 전기적인 도전성을 가지는 수지를 사용하였으며 이들의 물성변화를 위해 첨가물질로 차콜(charcoal)을 사용하였다. 결과적으로 접착물질(실리콘 화합물)이 사용되었을 때가 사용하지 않았을 때보다 같은 전압에서 많은 오존발생량을 보여주었다. 또한 접착물질이 사용되었을 때는 순수한 실리콘 화합물이 사용된 경우가 도전성을 가지는 접착물질이 사용되었을 때보다 많은 오존발생량을 보여주었다.

• 한국표면공학회지
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• 제29권5호
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• pp.371-378
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• 1996

An RF inductively coupled plasma (ICP) torch has been developed as a typical thermal plasma generator and reactor. It has been applied to various materials processings such as plasma flash evaporation, thermal plasma CVD, plasma spraying, and plasma waste disposal. The RF ICP reactor has been generally operated under one atmospheric pressure. Lately the characteristics of low pressure RF ICP is attracting a great deal of attention in the field of plasma application. In our researches of RF plasma applications, low pressure RF ICP is mainly used. In many cases, the plasma generated by the ICP torch under low pressure seems to be rather capacitive, but high density ICP can be easily generated by our RF plasma torch with 3 turns coil and a suitable maching circuiit, using 13.56 MHz RF generator. Plasma surface modification (surface hardening by plasma nitriding and plasma carbo-nitriding), plasma synthesis of AIN, and plasma CVD of BN, B-C-N compound and diamond were practiced by using low pressure RF plasma, and the effects of negative and positive bias voltage impression to the substrate on surface modification and CVD were investigated in details. Only a part of the interesting results obtained is reported in this paper.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2004년도 춘계학술발표대회
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• pp.655-658
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• 2004

본 논문은 구문패턴과 의미망을 이용하여 복합명사를 생성하는 방법을 제안하고, 제안된 방법으로 설계 구현된 시스템, 복합명사 생성기(Compound Nouns Generator : CNG)를 제시한다. 복합명사에 관한 연구는 형태적, 구문적, 의미적인 관점에서의 분석과 생성에 이르기까지 폭넓게 진행되고 있다. 본 논문에서는, 사전에 등재된 표제어만을 복합명사로 인정하고, 나머지는 1차적으로 명사 연결구로 파악한다. 그리고 이것을 다시 신형 복합명사와 명사 연결구로 파악함으로써, 복합명사에 대한 명확한 기준을 제시하여 자연언어처리, 정보검색 등에서 효율성을 높이고자 하였다. 본 논문에서 제안한 시스템은 복합명사 확장을 위해 구문패턴을 자동 생성함으로써 시스템의 융통성을 향상시키고, 구문패턴과 의미망을 통해 생성된 복합명사와 명사 연결구의 말뭉치상의 빈도정보를 이용함으로써 고빈도의 명사 연결구가 복합명사로서 굳어질 수 있는 가능성을 보여주기도 한다. 또한, 구문패턴과 의미망을 통해 생성된 명사 연결구를 비교하여 생성된 신형 복합명사는 구문패턴에 의해 뜻풀이가 자동으로 생성된다.

• 대한의생명과학회지
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• 제14권1호
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• pp.39-45
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• 2008

Inflammation is the complex biological response of injured tissues to harmful stimuli. A cascade of biochemical events propagates and matures the inflammatory response, involving the local vascular system, the immune system, and various cells within the injured tissue. The immune system is often involved with inflammatory disorders, demonstrated in both allergic reactions and some myopathies, with many immune system disorders resulting in abnormal inflammation. An Arbitrary Waveform Generator (AWG) is a piece of electronic test equipment used to generate electrical waveforms for the treatment of patients. The patients with gastritis and arthritis have been known to have a relatively favorable prognosis with AWG treatment. Accordingly, we examined the effects of AWG treatment in gastritis and arthritis animal model. The compound 48/80 was used to induce animal gastritis model. The tissue malone dialdehyde (MDA) and serum histamine levels, and the activity of superoxide dismutase (SOD) in stomach tissue were measured. The tissue MDA and serum histamine levels in AWG treated groups exhibited the decreased tendency compared with control group, whereas the tissue SOD activity was slightly increased. The Freund's complete adjuvant was used to induce animal arthritis model as well. The paw edema volume and the width of ankle joint were determined. The AWG treatment significantly decreased the paw edema volume after 5th day of treatment. Although further studies should be performed to confirm the effects of AWG treatment, present study suggest that AWG treatment might be used as a complementary treatment for the gastritis or arthritis treatment.