• 한국시뮬레이션학회논문지
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• 제8권3호
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• pp.49-66
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• 1999

Semiconductor wafer fabrication is known to be one of the most complex manufacturing processes due to process intricacy, random yields, product diversity, and rapid changing technologies. In this study we are concerned with the impact of lot release and dispatching policies on the performance of semiconductor wafer fabrication facilities. We consider several semiconductor wafer fabrication environments according to the machine failure types such as no failure, normal MTBF, bottleneck with low MTBF, high randomness, and high MTBF cases. Lot release rules to be considered are Deterministic, Poisson process, WR(Workload Regulation), SA(Starvation Avoidance), and Multi-SA. These rules are combined with several dispatching rules such as FIFO (First In First Out), SRPT (Shortest Remaining Processing Time), and NING/M(smallest Number In Next Queue per Machine). We applied the combined policies to each of semiconductor wafer fabrication environments. These policies are assessed in terms of throughput and flow time. Basically Weins fabrication setup was used to make the simulation models. The simulation parameters were obtained through the preliminary simulation experiments. The key results throughout the simulation experiments is that Multi-SA and SA are the most robust rules, which give mostly good performance for any wafer fabrication environments when used with any dispatching rules. The more important result is that for each of wafer fabrication environments there exist the best and worst choices of lot release and dispatching policies. For example, the Poisson release rule results in the least throughput and largest flow time without regard to failure types and dispatching rules.

• Journal of Plant Biotechnology
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• 제39권1호
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• pp.1-12
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• 2012

With the increasing advances in Brassicaceae genetics and genomics, considerable progress has been made in the transformation of Brassicaceae. Transformation technologies are now being exploited routinely to determine the gene function and contribute to the development of novel enhanced crops. $Agrobacterium$-mediated transformation remains the most widely used approach for the introduction of transgenes into Brassicaceae. In $Brassica$, the transformation relies mainly on $in$ $vitro$ transformation methods. Nevertheless, despite the significant progress made towards enhancing the transformation efficiencies, some genotypes remain recalcitrant to transformation. Advances in our understanding of the genetics behind various transformations have enabled researchers to identify more readily transformable genotypes for use in routine high-throughput systems. These developments have opened up exciting new avenues to exploit model $Brassica$ genotypes as resources for understanding the gene function in complex genomes. Although many other Brassicaceae have served as model species for improving plant transformation systems, this paper summarizes on the recent technologies employed in the transformation of both $Arabidopsis$ and $Brassica$. The use of transformation technologies for the introduction of desirable traits and a comparative analysis of these as well as their future prospects are also important parts of the current research that is reviewed.

• Communications for Statistical Applications and Methods
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• 제25권3호
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• pp.307-319
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• 2018

High-throughput technologies enable the simultaneous evaluation of thousands of genes that could discriminate different subclasses of complex diseases. Ranking genes according to differential expression is an important screening step for follow-up analysis. Many statistical measures have been proposed for this purpose. A good ranked list should provide a stable rank (at least for top-ranked gene), and the top ranked genes should have a high power in differentiating different disease status. However, there is a lack of emphasis in the literature on ranking genes based on these two criteria simultaneously. To achieve the above two criteria simultaneously, we proposed to apply a previously reported metric, the modified area under the receiver operating characteristic cure, to gene ranking. The proposed ranking method is found to be promising in leading to a stable ranking list and good prediction performances of top ranked genes. The findings are illustrated through studies on both synthesized data and real microarray gene expression data. The proposed method is recommended for ranking genes or other biomarkers for high-dimensional omics studies.

• 한국정밀공학회지
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• 제28권4호
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• pp.513-520
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• 2011

The NIL processes have been studied to implement low cost, high throughput and high resolution application. A RNIL(roller NIL) is an alternative approach to flat nanoimprint lithography. RNIL process is necessary to transfer patterns on flexible substrates. Compared with flat NIL, RNIL has the advantages of better uniformity, less pressing force, and the ability to repeat the patterning process continuously on a large substrate. This paper studies the design, construction and verification of a thermal RNIL system. The proposed RNIL system can easily adopt the flat shaped hot plate which is one of the most important technologies for NIL. The NIL system can be used to transfer patterns from a flexible stamp to a flexible substrate, from a flexible stamp to a Si substrate, and from a roller stamp to a flexible substrate, etc. Patterning on flexible substrates is one of the key technologies to produce bendable displays, solar cells and other applications.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8_spc호
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• pp.1321-1330
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• 2019

Recent development of novel techniques in systems biology have been used to improve and manipulate the rumen microbial ecosystem and gain a deeper understanding of its physiological and microbiological interactions and relationships. This provided a deeper insight and understanding of the relationship and interactions between the rumen microbiome and the host animal. New high-throughput techniques have revealed that the dominance of Proteobacteria in the neonatal gut might be derived from the maternal placenta through fetal swallowing of amniotic fluid in utero, which gradually decreases in the reticulum, omasum, and abomasum with increasing age after birth. Multi "omics" technologies have also enhanced rumen fermentation and production efficiency of dairy goats using dietary interventions through greater knowledge of the links between nutrition, metabolism, and the rumen microbiome and their effect in the environment. For example, supplementation of dietary lipid, such as linseed, affects rumen fermentation by favoring the accumulation of ${\alpha}$-linolenic acid biohydrogenation with a high correlation to the relative abundance of Fibrobacteriaceae. This provides greater resolution of the interlinkages among nutritional strategies, rumen microbes, and metabolism of the host animal that can set the foundation for new advancements in ruminant nutrition using multi 'omics' technologies.

• 한국환경농학회:학술대회논문집
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• 한국환경농학회 2009년도 정기총회 및 국제심포지엄
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• pp.119-126
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• 2009

In recent years, research at the Environmental Microbial and Food Safety Laboratory (EMFSL), Agricultural Research Service (ARS) has focused on the development of novel image-based sensing technologies to address agro-food safety concerns, and transformation of these novel technologies into practical instrumentation for industrial implementations. The line-scan-based hyperspectral imaging techniques have often served as a research tool to develop rapid multispectral methods based on only a few spectral bands for rapid online applications. We developed a newer line-scan hyperspectral imaging platform for high-speed inspection on high-throughput processing lines, capable of simultaneous multiple inspection algorithms for different agro-food safety problems such as poultry carcass inspection for wholesomeness and apple inspection for fecal contamination and defect detection. In addition, portable imaging devices were developed for in situ identification of contamination sites and for use by agrofood producer and processor operations for cleaning and sanitation inspection of food processing surfaces. The aim of this presentation is to illustrate recent advances in the above agro.food safety sensing technologies.

• 대한전자공학회논문지TC
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• 제46권4호
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• pp.29-39
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• 2009

제한된 전파 스펙트럼 자원은 전파 네트워크의 빠른 발전에 큰 장벽이 되고 있다. 대부분의 전파 스펙트럼은 면허 방식으로 분배되어 서비스에 이용되고 있다. 반면 비면허 방식으로 분배된 전파 스펙트럼은 전파를 이용한 서비스와 기술을 크게 향상하는데 큰 기여를 하였다. 최근에 무선인지 기술은 이러한 전파 스펙트럼 자원의 부족을 해결하기 위한 기술로써 주목받고 있다. 이 기술은 전파 스펙트럼을 효율적으로 사용 가능하도록 한다. 한편으로 멀티홉 기술이 에드홀 및 피어 투 피어 네트워크에서 집중적으로 연구되고 있으나 이동통신 네트워크에서 성능 향상을 위하여 멀티홉 기술의 연구는 최근에야 이루어지고 있다. 멀티홉 기술은 음영 지역에 고속의 데이터를 제공하고 적은 비용으로 서비스 영역을 효율적으로 확장할 수 있는 기술이다. 이동통신 시스템에서 스펙트럼 이용률을 극대화하는 무선인지 멀티홉 기술의 연구는 그 유용성에도 불구하고 아직까지 많지 않았다. 따라서 본 논문에서는 시스템 스루풋을 최대화 하는 무선인지 멀티홉 기술을 적용한 네트워크를 제안한다. 본 논문에서 제안된 시스템의 스루풋 성능을 주사용자와 부사용자의 전파 반경 및 이용률 파라메터와 같은 다양한 파라메터를 사용하여 해석적으로 모델링하고 수치해석을 통하여 제안된 시스템의 성능이 현재의 시스템에 비하여 크게 향상됨을 보였다.

• 한국통신학회논문지
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• 제39C권7호
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• pp.528-537
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• 2014

조선 산업과 IT의 융합으로 인해 선박에서의 데이터 사용량이 계속적으로 증가할 것으로 예상됨에 따라, 많은 양의 데이터를 처리하기 위한 여러 무선통신 기술들이 논의되고 있다. 특히 다중 안테나 시스템은 높은 수율을 제공할 것으로 기대되는 기술 중 하나이다. 본 논문에서는 공간 다중화 해양 통신 시스템에서 채널 특성과 기지국의 빔 전송 각도를 고려하여 기지국이 서비스 할 선박을 선택하는 알고리듬을 제안한다. 무선 채널의 클러스터링 특성을 이용하여 선박이 수신 받는 신호를 최대화하는 방식으로 시스템의 수율을 증가시켰다. 또한 빔 간섭이 큰 선박을 제외하고 선택하는 방식으로 선박 선택에 걸리는 시간을 단축시켰다. 제안하는 알고리듬의 성능 분석을 위해 모의실험 한 결과, 제안하는 알고리듬의 수율은 전수조사 알고리듬과 근사하지만 연산의 복잡성은 크게 줄어드는 것을 확인할 수 있다.

• 한국통신학회논문지
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• 제29권9A호
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• pp.1075-1082
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• 2004

무선랜은 우선으로 근거리 디바이스들을 연결하는 통신기술로 IEEE 의 802.11 이 대표적인 프로투콜로 사용되 고 있다 IEEE 802.11 에서 정의된 DCF (Distributed Coordination Fun 이 ion) 는 사용 4 가 증가하고 부하가 커질수록 전송률 ,throughput) 과 데이터 손실률 -(drop rate) 이 커지는 단점을 가지고 있다. 본 논문에서는 무선랜 환경에서 효율적인 최소 동적윈도우 (CWmin) 의 적용을 통한 성능향상방법을 제안하고 분석과 시율레이션을 통해 제안하는 방법이 기존 DCF 보다 성능이 향상됨을 입증한다. 제안하는 동적최소윈도우 방법은 우선 스테이션의 개수가 증가 할수록 , 무선네트워크에 걸리는 부하가 커질수록 성능향상정도가 더욱 커지게 된다. 따라서 향후 고밀도 무선랜 환경에서 효과적일 것이라 기대된다.

• Genomics & Informatics
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• 제17권1호
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• pp.6.1-6.9
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• 2019

Understanding the role of the microbiome in human health and how it can be modulated is becoming increasingly relevant for preventive medicine and for the medical management of chronic diseases. The development of high-throughput sequencing technologies has boosted microbiome research through the study of microbial genomes and allowing a more precise quantification of microbiome abundances and function. Microbiome data analysis is challenging because it involves high-dimensional structured multivariate sparse data and because of its compositional nature. In this review we outline some of the procedures that are most commonly used for microbiome analysis and that are implemented in R packages. We place particular emphasis on the compositional structure of microbiome data. We describe the principles of compositional data analysis and distinguish between standard methods and those that fit into compositional data analysis.