• International Journal of Computer Science & Network Security
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• 제21권3호
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• pp.31-36
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• 2021

RNA sequencing (RNA-Seq) is a technology that facilitates transcriptome analysis using next-generation sequencing (NSG) tools. Information on the quantity and sequences of RNA is vital to relate our genomes to functional protein expression. RNA-Seq data are characterized as being high-dimensional in that the number of variables (i.e., transcripts) far exceeds the number of observations (e.g., experiments). Given the wide range of dimensionality reduction techniques, it is not clear which is best for RNA-Seq data analysis. In this paper, we study the effect of three dimensionality reduction techniques to improve the classification of the RNA-Seq dataset. In particular, we use PCA, SVD, and SOM to obtain a reduced feature space. We built nine classification models for a cancer dataset and compared their performance. Our experimental results indicate that better classification performance is obtained with PCA and SOM. Overall, the combinations PCA+KNN, SOM+RF, and SOM+KNN produce preferred results.

• 한국건설관리학회논문집
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• 제14권4호
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• pp.55-64
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• 2013

온실가스 에너지 목표관리제가 시행됨에 따라, 해당 사업장은 2020년까지 온실가스 배출 전망치 대비 30% 이상을 의무적으로 감축해야 한다. 에너지소비의 큰 비중을 차지하는 대학교 부문 역시 온실가스 감축이 요구됨에도 불구하고, 교육기관의 특성 상 에너지 절감에 투자할 수 있는 예산은 한정적이므로 고가의 대응책 적용에는 한계가 따른다. 따라서 본 연구는 서울대학교 관악캠퍼스를 대상으로 실 레벨에서 쉽게 적용 가능한 저가의 에너지감축 방안을 도출하고, 이를 통한 최대감축잠재량을 산정하는 사례연구를 목적으로 한다. 먼저, 관악캠퍼스 내 표본이 될 11개 용도의 실을 뽑아 1월 1일부터 7월 31일까지 에너지소비량을 매일 실측하였고, 실별 전력기기 계수 조사를 통해 실용도별 표준모형을 구축하였으며, 사용자 인터뷰와 설문 및 행정조사를 통해 전력소비패턴을 분석함으로써 실용도 표준모형 기반의 기기별 소비전력량을 산출하였다. 이를 기반으로, 32개의 감축기술 및 실천프로그램을 도출하여 실용도 표준모형에 적용하고 각 프로그램별 최대감축비율을 기기별 소비전력량에 곱해 기기별 최대감축량을 유도함으로써, 실별 월별 최대감축량과 관악캠퍼스 최대감축잠재량을 산정하였다. 그 결과, 본 연구가 제안한 감축기술 및 실천프로그램의 적용 시 1월부터 7월까지 약 $5,311tCO_2$-eq 즉 동일기간 관악캠퍼스 전체 에너지 사용량의 12.66%에 해당되는 양을 감축할 수 있으며, 2016년까지 서울대학교 필요감축량의 24.48%를 감축할 수 있는 것으로 조사되었다.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.473-474
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• 2010

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2169-2171
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• 2014

• 한국정밀공학회지
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• 제30권7호
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• pp.694-701
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• 2013

The gear-reduction units of Korean high-speed trains consist of a motor reduction unit, an axle gear box reduction unit, and a tripod joint shaft. A reduction gear unit is a gearbox used to reduce the rotational speed of the input shaft to a slower rotational speed on the output shaft. This reduction in output speed helps to increase torque. Defective reduction gear units in high-speed trains are caused by damage to the gear or by gear fatigue. To diagnose potential problems, it is important to know the vibration characteristics of the reduction gear units. In this study, we analyzed the vibration characteristics of reduction gears under various conditions. The test setup included a full-scale test rig to evaluate reduction gear under both normal and extreme operating conditions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.169-174
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• 2012

Reduction unit is one of the most important components for railway vehicle because torque of motor must be transmitted to wheels of vehicle by reduction unit. However, According to advanced studies, it has been often broke down due to the damage, fatigue and wear of gear. To solve this problem, defect diagnosis methods of gear have been mainly using the vibration diagnosis technology through vibration waveform and frequency analysis. However, We should know vibration characteristics of normal state reduction unit prior to defect diagnosis. So in this paper, We had analyzed vibration characteristics of reduction unit in order to utilize monitoring system development. Comparison of targets is the vibration characteristics of normal state reduction unit about Electric Multiple Unit(EMU) and the High-speed trains(KTX, KTX II).

• Nuclear Engineering and Technology
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• 제35권1호
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• pp.25-34
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• 2003

The research on the development of the fault monitoring system for the thermal reduction reactor has been performed preliminarily in order to support the successful operation of the thermal reduction reactor. The final task of the development of the fault monitoring system is to assure the integrity of the thermal$_3$ reduction reactor by the acoustic emission (AE) method. The objectives of this paper are to identify and characterize the fault-induced signals for the discrimination of the various AE signals acquired during the reactor operation. The AE data acquisition and analysis system was constructed and applied to the fault monitoring of the small- scale reduction reactor, Through the series of experiments, the various signals such as background noise, operating signals, and fault-induced signals were measured and their characteristics were identified, which will be used in the signal discrimination for further application to full-scale thermal reduction reactor.

• Environmental Engineering Research
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• 제9권3호
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• pp.119-124
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• 2004

• 한국세라믹학회지
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• 제43권5호
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• pp.265-269
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• 2006

We have deposited NiO films by RF sputtering on $Al_2O_3/SiO_2/Si$ and 100 nm-thick Gd doped $CeO_2$ covered $Al_2O_3/SiO_2/Si$ substrates at various $Ar/O_2$ ratios. The deposited films were reduced to form porous Ni thin fllms in 4% $H_2\;at\;400^{\circ}C$. For the films deposited in pure Ar, the reduction was retarded due to the thickness and the orientation of the NiO films. On the other hand, the films deposited in oxygen mixed ambient were reduced and formed porous Ni films after 20 min of reduction. We also investigated the possibility of using the films for the single chamber operation by studying the electrical property of the films in the fuel/air mixed environment. It is shown that the resistance of the Ni film increases quickly in the mixed gas environment and thus further improvements of Ni-base anodes are required for using them in the single chamber operation.

• 한국기계가공학회지
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• 제18권10호
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• pp.54-59
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• 2019

The final reduction drive in tactical vehicles has a wear-pad that helps to maintain adequate end floating when the hub assay operates. The input axis and sun gear move repeatedly with the axis when tactical vehicle is operating. The hub assay is designed so that the wear pads won't seize during operation. Seizure of the wear pads during operation results in oil leakage. In our study, the fault mechanism was analyzed to prevent the seizure of the wear pads and an optimal design for the shape and material of the wear-pad was explored. We then observed the changes in temperature, shape, and material of several important parts.