• 한국음향학회:학술대회논문집
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• 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
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• pp.123-126
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• 1992

A new class of data transformation matri is introduced for estimation of angles of arrivals by the rank reduction of multiple wideband sources. The proposed unitary focusing matri minimizes the average of the squared norm of focusing error over the angles of interest without a priori knowledge of source locations. The merit that result as a consequence is a lower resolution threshold. These matrices can be applied to the case of the multigroup sources. Simulations and the comparison of statistical performance are compared with the algorithms (especially, spatial resampling method) which does not require the pre-estimation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.261-264
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• 1999

This paper presents a circuit-level method to deal with transistor nonuniformity In this method, which is called transistor slicing, a transistor is implemented as a parallel connection of multiple smaller transistors. The paper analyzes the method and demonstrates that transistor slicing can effectively reduce the nonuniformity in TFT mobility and threshold voltage. The method is particularly useful in Implementing analog functions using poly-silicon TFTs which show a significant level of nonuniformity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.199-201
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• 2002

This paper showed that there exists a non-linear relationship between MVAR and MW, and the rage of the threshold value of MVAR is 56 to 67. Also, we tried the one-hour ahead forecasting model of MVAR using the MW as the explanary variable.

• Clinical Endoscopy
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• 제57권1호
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• pp.18-23
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• 2024

Computer-assisted polyp characterization (computer-aided diagnosis, CADx) facilitates optical diagnosis during colonoscopy. Several studies have demonstrated high sensitivity and specificity of CADx tools in identifying neoplastic changes in colorectal polyps. To implement CADx tools in colonoscopy, there is a need to confirm whether these tools satisfy the threshold levels that are required to introduce optical diagnosis strategies such as "diagnose-and-leave," "resect-and-discard" or "DISCARD-lite." In this article, we review the available data from prospective trials regarding the effect of multiple CADx tools and discuss whether they meet these thresholds.

• 한국광학회:학술대회논문집
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• 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.59-63
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• 1990

Two-stage TEA(transversely excited atmospheric pressure) CO2 laser amplifier system, Amp I and Amp II are consturcted and their amplification characteristics are investigated theoretically and experimentally. Multiple-wire corona preionization method is used for uniform discharge in laser oscillator and amplifiers. At optimumm gas ratio, CO2 : N2 : He = 1 : 1 : 3, output pulse energy of the oscillator is 0.4J and finally two-stage amplification gives 1.5J output energy which is larger than pumping threshold of para-H2 Raman laser. The rate equations of the amplifiers are solved numerically, and the results are compared with the experimental results. In conclusion, the small signal gain cocfficient of AMP I is 0.025/cm and that of AMP II is 0.02/cm.

• 한국경영과학회지
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• 제32권1호
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• pp.53-60
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• 2007

We consider the discrete-time $Geo^x/G/1$ queues under N-policy with multiple vacations (a single vacation) and setup time. In this queueing system, the server takes multiple vacations (a single vacation) whenever the system becomes empty, and he begins to serve the customers after setup time only if the queue length is at least a predetermined threshold value N. Using the heuristic approach, we derive the mean waiting time for both vacation models. We demonstrate that the heuristic approach is also useful for the discrete-time queues.

• 한국통신학회논문지
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• 제36권1C호
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• pp.22-27
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• 2011

본 논문에서는 하향링크 다중 사용자 Multiple Input Multiple Output (MIMO)채널 환경에서 셀 용량을 증가시키기 위한 Zero Forcing 기반의 효율적 사용자 선택 기법을 제안한다. 이 기법에서는 채널 전력이 미리 결정된 한계점을 초과하는 사용자들을 주요 그룹으로 구성한다. 100명의 사용자와 4개의 기지국 안테나를 가정한 컴퓨터 모의실험을 통해서 제안된 기법이 기존 기법보다 0.33 bps/Hz 만큼 젤 용량을 추가로 제공할 수 있음이 밝혀졌다.

• ETRI Journal
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• 제31권4호
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• pp.419-428
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• 2009

A question answering (QA) system can be built using multiple QA modules that can individually serve as a QA system in and of themselves. This paper proposes a learnable, strategy-driven QA model that aims at enhancing both efficiency and effectiveness. A strategy is learned using a learning-based classification algorithm that determines the sequence of QA modules to be invoked and decides when to stop invoking additional modules. The learned strategy invokes the most suitable QA module for a given question and attempts to verify the answer by consulting other modules until the level of confidence reaches a threshold. In our experiments, our strategy learning approach obtained improvement over a simple routing approach by 10.5% in effectiveness and 27.2% in efficiency.

• 전자공학회논문지A
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• 제32A권8호
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• pp.119-125
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• 1995

Strained multiple quantum well(SMQW) PBH-DFB-LDs emitting at 1.55$\mu$m wavelength has been fabricated using OMVPE and LPE crystal growth tecnique. Using the SMQW active layer, a linewidty enhancement factor of 2.65 was obtained at lasing wavelength and consequnently, packaged 42 modules showed a very low average chirp of 0.44nm at 2.5Gbps NRZ direct modulation. The 77 devices showed average threshold current of 8.72mA and average slope efficiency of 0.181 mW/mA, and single longitudinal mode operation with SMSR larger than 30dB up to 5mW. Among the 77 devices, standard deviation of lasing wavelength of 3.57nm was obtained owing to a good crystal growth uniformity.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.502-510
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• 2016

Considering video copy transform diversity, a multi-feature video copy detection algorithm based on a Speeded-Up Robust Features (SURF) local descriptor is proposed in this paper. Video copy coarse detection is done by an ordinal measure (OM) algorithm after the video is preprocessed. If the matching result is greater than the specified threshold, the video copy fine detection is done based on a SURF descriptor and a box filter is used to extract integral video. In order to improve video copy detection speed, the Hessian matrix trace of the SURF descriptor is used to pre-match, and dimension reduction is done to the traditional SURF feature vector for video matching. Our experimental results indicate that video copy detection precision and recall are greatly improved compared with traditional algorithms, and that our proposed multiple features algorithm has good robustness and discrimination accuracy, as it demonstrated that video detection speed was also improved.