• Journal of Korea Society of Industrial Information Systems
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• v.8 no.2
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• pp.14-20
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• 2003

This paper presents a text extraction method of camera based document image. It is more difficult to recognize camera based document image in comparison with scanner based image because of segmentation problem due to variable lighting condition and versatile fonts. Both document binarization and character extraction are important processes to recognize camera based document image. After converting color image into grey level image, gray level normalization is used to extract character region independent of lighting condition and background image. Local adaptive binarization method is then used to extract character from the background after the removal of noise. In this character extraction step, the information of the horizontal and vertical projection and the connected components is used to extract character line, word region and character region. To evaluate the proposed method, we have experimented with documents mixed Hangul, English, symbols and digits of the ETRI database. An encouraging binarization and character extraction results have been obtained.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.59-67
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• 2009

본고를 통해 초고주파 이론과 공학 분야는 물론 물리학, 재료공학의 기초 학문 분야에서도 지대한 관심을 모으고 있는 Metamaterial(MTM) 구조에 대해 조명하고자 한다. 먼저 MTM의 핵심이라고 할 수 있는 Left-Handedness(LH) 왼손 전파 법칙과 LH 발생 재질인 Double Negative(DNG) 재질에서의 전파 특성을 상대 유전율과 상대 투자율 평면에서 확인하고, 일반 매질인 Double Positive(DPS)형인 오른손 전파 법칙 Right-Handedness(=RH) 매질과의 결합(Composite Right-and Left-Hnaded=CRLH)에서 얻어지는 특징들을 살펴본다. 특히 DPS와 DNC의 결합에서 얻을 수 있는 음의 공진과 0차 공진(Zero-Order Resonance)을 언급하고 ZOR을 응용한 RF 부품의 소형화와 특성 개선사례를 소개한다. 또한, 안테나와 전자파 산란 특성에 MTM의 특수한 성질을 이용하여, 크기를 줄이거나 표면파를 억제하거나 혹은 방사 개구를 확대 또는 렌즈 특성을 얻어낸 사례도 언급된다 그리고 LH 특성은 아니지만 MTM 계열인 ENG(Epsilon Negative), MNG(Mu Negative), ENZ(Epsilon Near Zero)를 응용한 예들을 보이고, MTM 관점에서 FSS(Frequency Selective Surface )의 특성을 논의하고, 그간에 발표된 대표적 MTM 연구 결과에 대한 소개를 마치고자 한다.

• Journal of the Speleological Society of Korea
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• v.46 no.47
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• pp.35-47
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• 1996

동굴의 환경파괴는 환경의 변화에서 오는 경우와 동굴 개발에 따른 인위적인 파괴 등에 의한 것이라고 하겠다. 동굴이 개발되면 그 당시부터 동굴의 파괴, 오손 및 오염은 시작된다. 물론 동굴이 개발되어 관광객의 출입이 많은 동굴에서는 개발 이전의 동굴환경이 그대로 보존되고 있을 리 만무하다. 그러나 이런 피해를 최소한으로 하고, 좋은 환경을 지속적으로 보완하기 위해서는 많은 노력이 필요하다. 화암동굴에 대한 환경보전을 위해 지질구조, 통로시설, 일반시설, 전기 및 조명, 생태환경, 운영관리 분야 둥에서 안전진단을 한 결과 여러 분야에서 동굴 개발 이후 미흡한 점이 지적되어 이에 대한 보완이 시급하다고 지적되었다. 동굴의 환경은 그 원칙이 암흑세계여야 한다. 더구나 항상 어둡고 동굴내의 온도와 습도가 크게 변하지 않는 원래의 동굴환경이 있어야 특수한 지하생물, 즉 동굴생물도 서식하게 되고 동굴 내의 이차생성물도 정상적으로 성장할 수 있는 것이다. 따라서 동굴의 환경보전은 가능하면 동굴 속의 이차생성물을 계속적으로 성장시켜 이른바 지하궁전 또는 지하복마전의 화려하고 무시무시한 동굴환경을 이루게 되는 것이다. 이와 같은 원리로 화암동굴 벽면의 종유벽(유석, 황금종유벽)과 대석주, 대석순, 그리고 벽면과 바닥의 석순 등이 이루어졌으므로 동굴환경의 유지는 절대적으로 필요한 것이다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.138-143
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• 2006

This research emphasis the commercialize and experiment in the quality of water treatment by making water treatment reactor. The hybrid water plasma torch used this research is excellent in tans of economical efficiency because of using existent neon transformer. Further more, It has excellent energy efficiency because it is manufactured by low electric power. Especially hybrid water plasma torch used this research has two filed of water plasma and inputs each strong point into the water. Following The data such as dissolved ozone(2.8[ppm]), hydrogen peroxide(100[ppm]), 2[PH], are very affordable data and immensely useful in sterilization. Those data have excellent result: perfect eradication of a colon bacillus within maximum 10 minute applying to sterilization processing of a colon bacillus.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.2
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• pp.16-22
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• 2004

The paper presents the effects of output-coupling power and small signal gain of selenium vapour multiline laser by discharge of either to $^4$He or $^3$He. The purity of the He gas was improved with a special He-fille.. The result shows that compared with those of $^4$He, the output-coupling power and small-signal gain of $^3$He increase in the most of the lines. Especially, the small-signal gain of $^3$He for the strong lines (497.6 nm, 499.3 nm, 506.9 nm, 517.6 nm, 522.8 nm, 530.5 nm) lies about 30% higher than that of $^4$He, and the output-coupling power from doubles to triples.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.8
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• pp.48-56
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• 2009

This paper presents the power conversion system for TIG-welder using the fuel cell stack Generally, power supply for TIG-welder uses the front-ended diode bridge rectifier by common AC power source. In this case, power supply of TIG-welder increases in volume because of using bulky capacitor and diode-rectifier. Also, input current includes ripple and harmonics. Moreover, TIG-welder will be demand the power supply with lightweight and easy movement in the areas like as the islands and mountainous areas or the special environment are not use common AC power source. Thus, input power of the power conversion system for TIG-welder is used PEMFC(Polymer Electrolyte Membrane Fuel Cell), and the power conversion system is comprised of full-bridge converter with function of boost converter and inverter welding source, in this paper. The proposed power conversion system which is power supply for TIG-welder was verified by computer simulations and experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.33-41
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• 2006

In the modem power distribution systems, there are lots of zero-phase current harmonics in the neutral power line due to much usages of the controlled switching devices, various semiconductor power converting systems, OA(Office Automation) equipments, PC etc. In order to minimize the current harmonics a zero-phase neutral line current eliminating reactor (NHER) is designed and analyzed its performance using the finite element program. For the design of NHER a program is developed using C++ program. To verify the program a case model(380/220[V], 200[A]) is designed and analyzed by the developed program. As the results of the optimal design, the core loss is reduced by 26[%] with eliminating of the current harmonics. Especially the ninth harmonics is much reduced as compared with the others. When the design of NHER is adapted to the load of the power system, the eliminating effect and efficiency of the device will be much better

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.3
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• pp.103-114
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• 2004

This paper deals with a system that is capable of recognizing hand-signals in 3-dimensional space. The system uses 2 color cameras as input devices. Vision-based gesture recognition system is known to be user-friendly because of its contact-free characteristic. But as with other applications using a camera as an input device, there are difficulties under complex background and varying illumination. In order to detect hand region robustly from a input image under various conditions without any special gloves or markers, the paper uses previous position information and adaptive hand color model. The paper defines a hand-signal as a combination of two basic elements such as 'hand pose' and 'hand trajectory'. As an extensive classification method for hand pose, the paper proposes 2-stage classification method by using 'small group concept'. Also, the paper suggests a complementary feature selection method from images from two color cameras. We verified our method with a hand-signal application to our driving simulator.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.32-37
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• 1999

The superposing effect of SPCP(Surfoce Induced Plasma Chemical Process) and corona discharge has been studied for rerroval of NOx from industrial flue gases. NOx rermval rates by SPCP, corona discharge and superposing discharge were monitored and compared. Parameters were the concentration and the flow rate of gas, frequency and the type of discharge. Experirrental results showed that NOx removal rate by sUIffPOSing discharge was 10-15[%] higher than that by the other two modes. The higher NOx. rermval rate was observed with the lower frequency of upper electrode in the combined reactor and with the higher frequency of lower electrode. 'The maximum obtainable NOx. rerroval rate by SPCP (18 [W]) and corona discharge (8.5 [W]) was 80[%] and 10[%], respectively. With the combination of the two modes, however, 90[%] of NOx removal rate was observed with the discharge power of 14 [W].14 [W].

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.87-94
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• 2002

As a section insulator dividing the electric railroad catenaries with different phases, the AC/DC section insulator which divides AC and DC railroad catenary have the complex structure, and suffer irregular abrasion on the surface or insulator rods when it is installed at the underground railroad. This paper intended as an investigation of the irregular abrasion of section insulators, provides the field measurements of abrasion level along insulator length and the abrasion patterns. The height variation of insulator parts and the balding length of insulators against pantograph's contact force are analysed experimentally, and the irregular abrasion mechanism is clarified with the help of theoretical analysis on the interaction between pantographs and section insulators. On the basis of experimental and theoretical analysis, the countermeasures to reduce the irregular abrasion are provided too.