• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.1371-1374
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• 2005

지금까지 IEEE 802.11 WLAN 에서 많이 연구되어진 주제는 노드들 간의 공평성(fairness)과 처리량(throughput)을 높이는데 중점이 맞추어진 것들이 대부분이었다. 성능을 높이기 위한 AP의 CW값에 관한 연구는 노드들 간에 관한 연구에 비하여 비교적 적은 편이다. 지금은 노드들과 AP가 충돌하게 되면 BEB(Binary Exponential backoff)방식으로 셋팅되어 사용하게 있기 때문에 1:N의 불공평한(unfairness) 상황이 발생한다. AP에서 노드들로 가는 하향링크(downlink) 전송이 많은 상황에서 AP가 다른 노드들과 똑같은 채널 접근확률을 가지는 것은 바람직하지 않기 때문에 AP에게 우선권(priority)을 주어 전체 성능을 높이는 것이 필요하다. 따라서 본 논문에서는 AP의 CW(Contention Window)값이 변화함에 따라 전체 성능에 끼치는 영향과 노드 수의 변화에 따른 AP의 적절한 백오프 CW값을 분석해 보고자 한다.

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.289-293
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• 1993

A Nd:YLF laser pumped by a CW GaAlAs laser diode(LD) at 792 nm has been designed and fabricated. The output power was investigated as a function of LD spectrum and pump power. A folded laser resonator was desinged to compensate for the astigmatism produced at the Brewster surface of Nd:YLF rod. We obtained output power of CW 1.1 Watt when the pumping power was 2.8 Watt and the output wavelength of LD was temperature tuned to the peak absorption line of Nd:YLF. The overall efficiency was 39 % and slope efficiency was 41 %.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.511-513
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• 2009

본 논문은 절전형 센서에 사용되는 24GHz대역의 CW 레이더 송수신기의 설계에 관한 것이다. K 밴드 대역의 송수신기 회로의 기본 구조와 분배기가 디자인 되었고 발진기, 주파수혼합기, 고주파 증폭기는 기존 제품을 사용하였다. 제안된 송수신기의 크기는 $35{\times}35{\times}10(mm)$이며 여러 가지 제품에 사용될 수 있도록 설계되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.310-313
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• 2005

CW laser dopant activation (CLDA) is suggested as an alternative to conventional thermal annealing. The sheet resistance of the ion doped poly-Si after CLDA is sufficiently low compared to the value measured after thermal annealing. The surface damage due to ion doping on the poly-Si can be recovered while CW laser scan for dopant activation. Therefore, the CLDA can be applied to LTPS processing.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.709-712
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• 1988

Ultrasonic Doppler Diagnostic System utilizes the Doppler effect for measurement of blood velocity. The sign of the Doppler frequency shift represents blood flow direction. CW(Continuous-Wave) Doppler System uses quadrature detection and phase rotation method to produce simultaneous independent audio and velocity signals for forward and reverse blood flow direction in the time-domain, had been fabricated. But time-domain analyzing such as audio evaluation and zero- crossing detection for instantaneous and mean frequnecy measurement do not provide both an accurate and quantitative result. Therefore, it is necessary to adopt frequency-domain technique to improve system performance. In this paper, we describe a unit which is composed of CW Doppler System and real-time spectrum analyzer (installed TMS 32010 DSP Chip). This unit shows time-dependent spectrum variation and mean velocity of Blood signal.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.26-33
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• 2006

The potential needs as well as visible needs of customer should be considered in order to research and analyze of the customer data. The methods to analyze customer data is classified into customer segmentation, clustering analysis model, forecasting customer response probability model, analysis of the customer break rate model and new customer analysis model by the purpose. In this study, we developed the CW-CLV (Correlation Weight Customer Lifetime Value)method that used AHP(Analytic Hierarchy Process)rule for enhance the reliability of customer data and quantitative analysis of the customer segmentation, based on CLV(Customer Lifetime Value). We suggest to new variables and methodology from determined CW-CLV coefficients, because all of companies respect to the diversified customers classification and complexity of consumers needs. Finally, we unfolded any company's scheduling added new methodology using simulation and leaded conclusion about the new methodology.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.4
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• pp.388-394
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• 1991

Alkaline protease producing bacteria were isolated from soil and identified as Bacillus sp. CW-1121. It was found that the production of alkaline protease reached to maximum in 5 day of fermentation at 4$0^{\circ}C$. The enzyme was purified by ammonium sulfate precipitation, gel filtration on Sephadex G-150 and DEAE-cellulose ion-exchange chromatography. The homogeneity of the purified enzyme was verified by polyacrylamide gel electrophoresis. The enzyme was purified 5.72 fold and yield of the enzyme purification was 16.71%. When the purified enzyme was applied to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight was estimated to be 55, 000.

• Korean Journal of Optics and Photonics
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• v.4 no.1
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• pp.66-72
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• 1993

Additive-pulse mode-locking (APM) was performed in a $1.053{\mu}m$ cw Nd:YLF laser by coupling a nonlinear external external cavity to the main cavity. The APM pulsewidth was 4.5 ps and the average output power was 1.5 W. This APM pulse was compressed by an optical fiber and a grating pair to be as short as 210 fs with a peak power of 17 kW.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.80-83
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• 2005

$Nd:YVO_4$ 연속발진 레이저 (CW laser)를 이용하여 다결정실리콘 (CLC poly-Si)을 제작하였다. CLC 다결정 실리콘의 결정화 영역은 결정립 크기에 따라 SLC(Sequential Lateral Crystallization) 영역, SLG(Super Lateral Grain) 영역 및 Small Grain 영역으로 구분된다. 레이저를 중첩스캔 하여 제작한 CLC 다결정실리콘의 경우, 레이저 스캔 경계에서 단결정립이 형성됨을 SEM으로 확인하고, CLC 다결정실리콘의 결정성을 XRD와 라만 스펙트럼(Raman spectrum)을 이용하여 조사하였다.

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.85-85
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• 1997

Czochralski 방법에 의해 육성된 Nd:YAG 단결정으로부터 CW mode의 1064nm laser를 발진시켰다. 육성된 단결정은 직경 50mm, 길이 120mm 이었으며, Nd 이온 농도는 O.2~0.9at% 이었다. 육성된 단결정 boule로 부터 결정학적 결함부위인 core 및 facet가 없는 양질의 단결정 부위를 Twyman-Green interferometer로 선빌하였다. 추출핀 부위는 절단, 가공, 연마공정 및 코팅 공정을 통해 직경 6.35mm, 길이 lOOmm의 laser rod를 제작하였다. 절단은 core drill, 또는 원통 연삭기를 사용하여 rod 형태로 가공하였으며, 상$\cdot$하면 polishing은 평행도 10", 직각도 5', 평활도 $\lambda$/10 수준까지 실험실에서 자체 가공하여 일반적인 laser 발진용 rod의 spec.을 만족시킬 수 있었다.