• 한국정보통신학회논문지
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• 제13권12호
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• pp.2525-2532
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• 2009

본 논문에서는 uncoded V-BLAST(Vertical Bell Laboratories Layered Space Time) 시스템에서 PSK 신호들을 joint-detection하기 위한 fast sphere decoder를 제안한다. 이른바 PSD라 불리는 제안된 디코더는 예비처리단계와 검색단계로 구성된다. PSD의 검색단계에서는 depth-first branch and bound 알고리즘을 통해 검출 후보가 되는 신호원들의 최상우선순위(best-first order)를 정하고 이 순위에 따라 신호를 검출하게 된다. 이 때 제안된 디코더는 최상우선순위(best-first order)를 정하는데 있어 계산복잡성을 줄이는 새로운 방법을 제안한다. 시뮬레이션 결과는 PSD에 의해 시스템의 복잡성은 줄이면서 시스템 성능은 ML과 동일하게 유지할 수 있음을 보여준다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2522-2525
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• 1999

Buck converter is considered to be one of the most widely used DC-DC converters due to its simple structure and high reliable performance. However, when it be combined with thin-film inductor, its own low inductance requires higher switching frequency in order to maintain optimum output ripple voltage and thus gives rise to extra switching losses. In view to overcoming such a technical in-convenience, soft switching fashion is suggested such as zero-voltage-switching of which an well known example is a Zero-Voltage-Switching clamp voltage(ZVS-CV) converter for which low inductance is imperatively required for ZVS operation. In order to support our suggestion, a 1W of ZVS-CV buck converter( Vo=3.3V, Iomax=0.3A, fs= 1.2MHz) is built by use of thin-film inductor, and then tested for comparing the measured efficiency between ours and conventional one. As the our results. the efficiency is improved about 2% at full load by the application of our concept.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2519-2525
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• 2016

There are several existing reports of microarray chip use for assessment of altered gene expression in different diseases. In fact, there have been over 1.5 million assays of this kind performed over the last twenty years, which have influenced clinical and translational research studies. The most commonly used DNA microarray platforms are Affymetrix GeneChip and Quality Control Software along with their GeneChip Probe Arrays. These chips are created using several quality controls to confirm the success of each assay, but their actual impact on gene expression profiles had not been previously analyzed until the appearance of several bioinformatics tools for this purpose. We here performed a data mining analysis, in this case specifically focused on ovarian cancer, as well as healthy ovarian tissue and ovarian cell lines, in order to confirm quality control results and associated variation in gene expression profiles. The microarray data used in our research were downloaded from ArrayExpress and Gene Expression Omnibus (GEO) and analyzed with Expression Console Software using RMA, MAS5 and Plier algorithms. The gene expression profiles were obtained using Partek Genomics Suite v6.6 and data were visualized using principal component analysis, heat map, and Venn diagrams. Microarray quality control analysis showed that roughly 40% of the microarray files were false negative, demonstrating over- and under-estimation of expressed genes. Additionally, we confirmed the results performing second analysis using independent samples. About 70% of the significant expressed genes were correlated in both analyses. These results demonstrate the importance of appropriate microarray processing to obtain a reliable gene expression profile.