• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.42-44
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• 2003

The paper presents the method and apparatus for conformal photoresist spray coating on the 3D structured substrate. The system consists of a high-temperature-rotational chuck, ultrasonic spray nozzle module, angle control module and nozzle moving module. The coating uniformity is acquired by controlling the moving speed of the ultrasonic spray nozzle across the substrate which is rotated constantly. To coat the photoresist conformally the spray angle of the nozzle and the temperature of the substrate are controlled during spray coating. The rotational chuck can be heated up by hot air or $N_2$. The photoresist (AZ1512) has been coated on the 3D structured wafer by spray coating system and the characteristics have been evaluated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1251-1253
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• 2001

This paper presents on capacity design of DC-fed-traction system. The system is introduced including a characteristics of train, feeding network configuration, and design method of substation arrangements. Optimal design procedures is described, and program for capacity computation of the system is presented using the nodal equation, K.C.L, K.V.L, Ohm's law and superposition theory. For the proof of the proposed algorithm, we accomplished the simulation of DC traction system for HA-Nam LRT. By considering whole component in DC traction system the conclusion will be much precise.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.219-220
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• 2006

In this study, m order to develop multilayer ceramics vibrator for ultrasonic nozzle, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3-Na_2CO_3$ as sintering aids and their piezoelectric and dielectric characteristics were investigated according to the aomunt of PbO. With increasing PbO contents. secondary phases were increased and phase structure were changed from tetragonal structure to rhombohedral structure and also electromechanical coupling factor were linearly decreased. At the composition ceramics with the sintering temperature of $870^{\circ}C$ and 1 mol% excess PbO, density, electromechanical coupling factor, dielectric constant, piezoelectric d constant and mechanical quality factor showed the optimum value of $7.879g/cm^2$, 0.55, 1149, 328pC/N, 1224, respectively for multilayer ceramics vibrator application for ultrasonic nozzle.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.225-227
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• 2006

Multilayer step down piezoelectric transformers were manufactured using PZN-PMN-PZT and PMN-PNN-PZT ceramics respectively. Sintering temperature of the ceramics was $940^{\circ}C$. And then. their electrical properties were investigated according to the variations of frequency and load resistance. The voltage step-up ratio of multilayer piezoelectric transformer showed the maximum values in the vicinity of 69 and 71kHz, respectively. At the load resistance of $100{\Omega}$, the piezoelectric transformers showed the temperature rises of about 21 and $18^{\circ}C$ at the output power of 15W and 18W, respectively. At the transformer with high effective electromechanical coupling factor($k_{eff}$), lower temperature increase was appeared.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1398-1401
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• 2004

In case the problem came into the headlight composed of a bulb, lens and reflecting mirror, it has a sealed-beam type which must exchange all and semi-sealed beam type which can exchange only bulb. The headlight of train must be used at the time of going into tunnel and atmospheric phenomena such as heavy snow, rain and foggy as a rule, also it can be used with whistle blow when the dangerous article appears. In this study, general technical specification to improve headlight of the KTX and G7 high speed train is described throughout investigation technique of the industrialized country and headlight specification of train which is on commercial service.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.583-588
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• 2004

Opening commercial service of KTX at the time of demanding more flexible train set for HONAM line and JEONLA line, it's necessary for the Korean High speed train, performing the stabilization; to modify the design in aspect of passenger and maintenance. In order to ensure the optimized interior design in Korean High speed train, it is necessary to review the major items such as disabled passenger facility, toilet, seat arrangement, compartment partition and door, access door, electrical cabinet, color and paint through the European standard and compare with other high speed train.

• 대한화학회지
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• 제39권5호
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• pp.408-413
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• 1995

A few t-amine substituted anilines and amides were synthesized and cyclized to pyrrolo[1,2-a]benzimidazole by heating in various solvents having different polarity. Subsequent nitration of cyclized compound followed by reduction and oxidation of resulting amine afforded quinone such as 7 in 14% yield. The formation of imidazole moiety by thermal cyclization was independent on the solvent polarity. The regiochemistry for the nitration of 4 was unambiguously determined by chemical transformation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.40-43
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• 1989

In recent years, Levitated transportation systems have been studied in many countries, Most vehicles used for these systems are driven by linear motors and are levitated magnetically. The magnetic train HDMAG-01 is a proto-type vehicle for low-speed in the range of 100cm/S. This paper presents an outline of the drawing, the testing and its results, describes theoretical models used and compares between computer simulation and test result.

• 한국전기전자재료학회논문지
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• 제19권1호
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• pp.52-57
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• 2006

Precision thin film resistors using evanohm R alloy were fabricated by do magnetron sputtering method. The physical and electrical properties of the resistors were studied after treatment of thermal annealing. The crystallization of the film was increased as the annealing temperature increase. Diffusion and oxidation of Cr and Al elements were occurred into the film surface. The minimum TCR values of 10.46 ppm/$^{\circ}C$ and 10.65 ppm/$^{\circ}C$ were measured at the annealing temperatures of $200^{\circ}C$ and $300^{\circ}C$, respectively. We are conducting additional studies to improve characteristics of our resistors for practical device application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1394-1396
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• 1999

It is important the protective relay should have high selectivity and sensitivity performance and it is achieved by correct setting of the relay parametes. The verification of accurate setting for the protective relay is very difficult before a actual fault occurs. This paper reports a diagnosis expert system to verify the correctness of the relay setting by using the operation results in the power system fault simulation.