• 한국의류산업학회지
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• 제7권3호
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• pp.291-300
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• 2005

The purpose of this study is to investigate, analyze the purchasing behavior of fashion goods according to life style and role model of preteen generation, and provide manager or marketing planner for the reference data so that they can understand preteen generation and make proper strategy efficiently. So called, preteen market focusing on 1014 generation (from ten to fourteen years old) is highlighted. This generation created between the year 1989 to 1993 after Seoul Olympic monopolize parent's love in abundant economic environment and rise to the core of consumption subject. Products aiming at this preteen generation continuously though consumption mind was shrunk greatly due to recession. Only 2~3 years before preteen market was regarded as grey zone which doesn't belong to not only children (between six and nine years old) but also teenagers (between fifteen to eighteen years old). But in recent day their purchasing powers have increased rapidly and age group is divided on details, so that preteen market has become a niche market. Subjects were 333 persons consisting of students in the 4th~6th grade of primary school and the 1st~2nd grade of middle school in Daegu city. Measuring instruments are as follows: 5questions to differentiate preteen generation, 22 questions to measure life style, 17questions (which have six sub-factors such as purchase motive, factor of product selection, utilization of informant, purchase time, purchase place, and purchase method) to measure the purchase behavior of fashion goods measurement, and 16 questions (which have four sub-factors such as parent, entertainer & sports stars, brothers and sisters, friends) to measure model of role. Statistical data were processed by SPSS 10.0 programs. Frequencies, Factor analysis, Cluster analysis, ANOVA, Cross analysis, Multiplex regression analysis, and Duncan's multiple range test were carried out.

• 한국초전도ㆍ저온공학회논문지
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• 제14권2호
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• pp.20-23
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• 2012

With continuous development of the 2nd generation HTS conductor, the critical current of the conductor is also increasing. However, many applications require more than 2 conductors in parallel to transport large current. Applications such as HTS power cables and some HTS current leads usually need much larger transport current than that provided by a single conductor and they require more than several tens of HTS conductors. In the case of parallel connection of multiple HTS conductors, the current distribution depends on the contact resistance of each conductor at the terminals for DC operation. The non-uniform distribution of the terminal resistances results in a non-uniform distribution of the current. The resultant current non-uniformity affects on the measurement of the I-V curve and the thermal performance of the multiple conductors. This paper describes the I-V curves obtained from multiply connected HTS conductors with different terminal contact resistances to investigate the relationship between the distorted I-V curve and heat generation.

• 대한전자공학회논문지
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• 제21권1호
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• pp.38-44
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• 1984

비선형 라만 산란현상을 이용하여 광섬유 라만 레이저를 실현함으로써 0.8-1.8μrm 파장 영역에서 200ps의 펄스 폭을 갖는 광 펄스를 생성시켰다. 이 광섬유 라만 레이저는 모드 고정과 Q-스위치가 동시에 된 Nd-YAG 레이저를 펌프로 사용한다. 본 실험과정에서 관찰된 2파동의 합 주파수 생성(two-wave sun frequency generation) 현상도 보고한다. 구현된 광섬유 라만 레이저를 이용하여 단일 모드 광섬유의 장파장 영역 색분산 특성을 측정하였으며, 측정된 광섬유의 재료분산 특성을 산정하였다.

• Journal of Welding and Joining
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• 제17권1호
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• pp.71-76
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• 1999

The real-time holographic interferometer with digital high-speed camera is applied to the experimental study of laser induced plasma/plume in pulsed Nd:YAG laser welding. A pulsed Nd:YAG laser with 1.2 kW average power is applied to generate laser induced plume. The recording speed of the high-speed camera is 3,000 f/s. The high speed photographs of weld plume without another visualization method, are compared with the visualization photographs with holographic interferometer. The radiation intensity from the laser induced plume is recorded by the high speed photographs, which fluctuated during laser radiation and disappeared after laser end. The density distribution of the plume is recorded by the holographic visualization method. The experimental results show the process of generation of the laser induced plasma/plume, and give the feasibility of quantitative measurement of laser induced plume in laser welding.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1690-1692
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• 1998

레이저가 산업 응용 전반에 걸쳐 아주 중요한 부분으로 자리잡고 있으며, 최근에 와서는 레이저 의료기기, 레이저 가공, 레이저 핵 융합 등과 같은 다수의 분야에 강력한 가시광이나 자외선 광을 필요로 하고 있다. 이에 본 실험실에서 보유한 다단메쉬 중첩 기술을 이용하여 각 중첩 메쉬에 같은 에너지를 인가했을 때의 레이저 출력과 녹색광 출력간의 상관관계와 다단메쉬에 따른 변환효율도 조사하였다.

• 한국광학회지
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• 제12권6호
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• pp.496-502
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• 2001

Scraper 출력경을 이용하는 불안전 공진기형 Nd:YAG 레이저 발진기에서 고리 두께 0.145mm인 원고리형 레이저광을 얻었으며, 초점거리에 위치한 베셀렌즈를 통과시켜 근사 무회절 광을 얻었다. 초점거리 1 m의 렌즈를 이용하여 얻은 근사 무회절 광에 대해서 렌즈로부터 거리 z의 변화에 따른 출력세기를 측정하여 이론과 비교 ·분석하였다. 또한 초점거리 5m의 렌즈를 이용한 경우, 거리 33m의 지점에서도 근사 무회절광이 지속됨을 확인하였다

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.1959-1963
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• 2007

SMES systems need cryogenic cooling systems. Conduction cooling system has more effective, compact structure than cryogen. In general, 2 stage GM cryocoolers are used for conduction cooling of HTS SMES system. 1st stages of cryocoolers are used for the cooling of current leads and radiation shields, and 2nd stages of cryocoolers for HTS coil. For the effective conduction cooling of the HTS SMES system, the temperature difference between the cryocooler and HTS coil should be minimized. In this paper, a cryogenic conduction cooling system for HTS SMES is analyzed to evaluate the performance of the cooling system. The analysis is carried out for the steady state with the heat generation of the HTS coil and effects of the thermal contact resistance. The results show the effects of the heat generation and thermal contact resistance on the temperature distribution.

• Journal of information and communication convergence engineering
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• 제6권4호
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• pp.391-395
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• 2008

Wideband terminal and base station is required to serve not only existing 1st and 2nd generation mobile communication systems but also 3rd generation systems. In this paper, we present a feasibility study on coaxial feed compact wideband antenna for UHF RFID reader application. The original antenna was designed for partial discharge detection sensor in high voltage diagnostic system. However, we modified the original prototype to achieve shifted down resonant frequency for wideband wireless communication applications. The experimental result shows good return loss characteristics and radiation patterns except for the total gain at each resonant frequency. The maximum measured gain was 2.45 dBi$\sim$3.18 dBi at 910MHz.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.341-344
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• 1988

This paper derives a condition foe constant voltage i constant frequency generation of doubly-fed induction generator. The condition is varied by the magnitude of output voltage, load current and its power factor, slip of the machine. Magnitude of output voltage is controlled by exiting voltage which is caculated by derived equation from operating condition. frequency of output voltage is controlled by injecting slip frequency to the rotor which is the difference between wanted output frequency and rotor frequency.

• 한국항해학회지
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• 제19권2호
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• pp.13-22
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• 1995

This paper presents the numerical analysis results of the viscous flow for a full ship model. The mass and momentum conservation equations are used for governing equations, and the flow field is discretized by the Finite-Volume Method for the numerical calculation. An algebraic grid and elliptic grid generation techniques are adopted for generation of the body-fitted coordinates system, which is suitable to ship's hull forms. Time-marching procedure is used to solve the three-dimensional unsteady problem, where the convection terms are approximated by the QUICK scheme and the 2nd-order central differencing scheme is used for other spatial derivatives. A Sub-Grid Scale turbulence model is used to approximate the turbulence, and the wall function is used at the body surface. Pressure and velocity fields are calculated by the simultaneous iteration method. Numerical calculations were accomplished for the Crude Oil Tanker(DWT 95,000tons, Cb=0.805) model. Calculation results are compared to the experimental results and show good agreements.