• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1133-1140
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• 2012

Ribonucleic acid interference (RNAi) inhibits the expression of target genes in a sequence-specific manner, and shows potential for gene knockdown in filamentous fungi, in which the locus-specific gene knockout occurs in low frequency. In this study, the function of the repressor of cellulase expression I (ACEI) was verified in Trichoderma koningii (T. koningii) YC01 through RNAi, and ace1-silenced strains with improved cellulase productivity were obtained. An expression cassette that transcribed the interfering double-stranded RNA (dsRNA) of ace1 was constructed and transformed into T. koningii, and the transformants, in which the expression of ace1 was successfully silenced, were selected. As a result of the ace1 gene silencing, the expression levels of the main cellulase and xylanase genes were elevated, and the enhanced production of total proteins, cellulase, and xylanase was observed in the cultivation. In addition, the down-regulation of ace1 resulted in an increasing expression of xyr1, but no clear variation in the expression of cre1, which suggested that ACEI acted as a repressor of the xyr1 transcription, but was not involved in the regulation of the cre1 expression. The results of this work indicate that ace1 is a valid target gene for enhancing enzyme production in T. koningii, and RNAi is an appropriate tool for improving the properties of industrial fungi.

• 한국콘텐츠학회논문지
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• 제10권4호
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• pp.19-27
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• 2010

최근에 고속 genome-wide RNA 간섭 스크리닝 기술은 복잡한 세포 기능을 이해하는 생명공학 연구의 핵심적인 도구로 자리 잡고 있다. 그러나 관련 연구에서 발생되는 수많은 영상을 수작업을 통해 분석하는 것은 많은 시간과 노력이 요구된다. 따라서 세포영상의 자동분석 기술은 매우 시급히 확보되어야 하는 기술이며, 그 중 영상 분할은 자동분석을 위한 첫 단계로서 가장 중요한 과정이라 할 수 있다. 세포영상의 자동분할에서는 영역의 겹침 현상과 영역별 모양의 다양성 및 영상 특성의 불균일성 등이 정확한 세포 분할을 어렵게 만드는 주원인으로 작용한다. 본 논문에서는 이러한 문제점을 극복하기 위해 영상 특징들의 국부적인 연속성과 특징 벡터 기반의 워터쉐드 알고리즘을 적용한 새로운 자동 세포 분할 알고리즘을 제안한다. 영상 특징들의 연속성을 국부적인 영역으로 제한함으로써 영역별 모양의 다양성 및 영상 특성의 불균일성에 따른 문제점을 극복할 수 있으며, 특징벡터의 사용을 통해 하나의 영상특징만을 고려한 경우 발생되는 겹침 영역에서의 분할 성능 저하를 개선할 수 있다. 세포영상 분석을 위한 소프트웨어 패키지인 Cellprofiler와의 비교/분석 실험을 통해 제안 알고리즘의 효율성을 입증하였다.

• Mass Spectrometry Letters
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• 제7권2호
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• pp.41-44
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• 2016

Secondary ion mass spectrometry (SIMS) is a promising tool to measure isotope ratios of individual uranium particles in environmental samples for nuclear safeguards. However, the analysis requires prior identification of a small number of uranium particles that coexist with a large number of other particles without uranium. In the present study, this identification was performed by scanning electron microscopy - energy dispersive X-ray analysis with automated particle search mode. The analytical results for an environmental sample taken at a nuclear facility indicated that the observation of backscattered electron images with × 1000 magnification was appropriate to efficiently identify uranium particles. Lower magnification (less than × 500) made it difficult to detect smaller particles of approximately 1 μm diameter. After identification, each particle was manipulated and transferred for subsequent isotope ratio analysis by SIMS. Consequently, the isotope ratios of individual uranium particles were successfully determined without any molecular ion interference. It was demonstrated that the proposed technique provides a powerful tool to measure individual particles not only for nuclear safeguards but also for environmental sciences.

• Design & Manufacturing
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• 제7권1호
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• pp.11-18
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• 2013

This paper presents the plastic inhomogeneous deformation behavior of bimetal composite rods during the axisymmetric and steady-state extrusion process through a conical die. The rigid-plastic FE model considering frictional contact problem was used to analyze the co-extrusion process with material combinations of Cu/Al. Different cases of initial geometry shape for composite material were simulated under different conditions of co-extrusion process, which includes the interference and frictional conditions. The main design parameters influencing on deformation pattern are diameter ratio of the composite components and semi-die angle. Efforts are focused on the deformation patterns, velocity gradient, predicted forming load and the end distance through the various simulations. Simulation results indicate that there is an obvious difference of forming pattern with various diameter ratio and semi-die angle. The analysis in this paper is concentrated on the evaluation of the design parameters on the deformation pattern of composite rod.

• Journal of Advanced Marine Engineering and Technology
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• 제21권4호
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• pp.381-386
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• 1997

The offsetting method using geometric properties of B-spline control polygon is more faster than using of general normal vector in offset processing. But this method itself does not solve the prob¬lems of loop removal in normal offsetting. Generally the distance between neighborhood spans of B-spline control polygon is greater than the offset distance, the loops are occurred in offsetting. For generating of the more precision tool-path in NC machining, the loops of offset must be removed. In this paper, two methods for loop removal are introduced in offsetting of B-spline curve. One is using the intersection of B-spline control span which being occurred of the loop. The other is using two B-spline curve divisions divided from original B-spline curve or its offset curve. After the inter¬section point of loop was searched, the loop being removed to cusp. Also the method for filleting of cusp is inspected to more precision cutting. It is shown that the offsetting using B-spline control polygon is more effective in the sculptured surface machining.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (A)
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• pp.43-45
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• 2006

Unlike RNA interference, whose usage is limited to eukaryotic cells, Peptide Nucleic Acid (PNA) technique is applicable to both eukaryotic and prokaryotic cells. PNA has been proven to be an effective agent for blocking gene expressions and has several advantages over other antisense techniques. Here we developed a parallel computing software that provides the ideal sequences to design PNA oligos to prevent any off-target effects. We applied a new approach in our location-finding algorithm that finds a target gene from the whole genome sequence. Message Passing Interface (MPI) was used to perform parallel computing in order to reduce the calculation time. The software will help biologists design more accurate and effective antisense PNA by minimizing the chance of off-target effects.

• 한국기계가공학회지
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• 제16권5호
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• pp.47-54
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• 2017

This study examines the implementation of a kinematic machining tool to evaluate the interference and collision phenomenon of 5-axis machining of wing ribs from airplanes, particularly for a large-size model airplane. We develop a machine simulation model of a parallel kinematic machining tool that can operate in a virtual space, which is equivalent to the authentic conditions in the field. The investigation of the simulation function elements indicates the necessity to generate the 6-axis machining, which attaches an angle head to the main axis of the machine. Using an NC program for the wing ribs, we attempt to verify the correspondence and conformity between the machine simulation model and the actual equipment.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.502-507
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• 2003

The HANARO, multi-purpose research reactor, 30 MWth open-tank-in-pool type, is under normal operation since it reached the initial critical in February 1995. The HANARO is used for fuel performance tests, radio isotope productions, reactor material performance tests, silicone semiconductor productions and etc. Specially, the HANARO is planning to produce a fission moly-99 of radio isotopes, a mother nuclide of Tc-99m, a medical isotope and is under developing a target handling tool for loading and unloading those at a flow tube (OR-5). The target should be sufficiently cooled in the flow tube without an interference with the cooling of the others and an induction of extremely vibration. This topic is described an analectic analysis for the cooling characteristics of the fission moly-99 target to find the minimum cooling water. It was confirmed through the analysis results that the minimum cooling water, about 2.717 kg/s flew through the flow tube under the worst case that the guide tube got no perforating holes for cooling water to pass through the holes and that the target was safely cooled under about seventy percent (70%) of the maximum allowable temperature of the target.

• Journal of Communications and Networks
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• 제11권2호
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• pp.187-195
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• 2009

The application of mathematical analysis to the study of wireless ad hoc networks has met with limited success due to the complexity of mobility, traffic models and the dynamic topology. A scenario based universal mobile telecommunications system (UMTS) time division duplex (TDD) opportunistic cellular system with an ad hoc behaviour that operates over UMTS frequency division duplex (FDD) licensed cellular network is considered. In this paper, we present a new routing metric which overall improves system performance in terms of interference and routing which operate in an ad hoc network in an opportunistic manner. Therefore we develop a simulation tool that addresses the goal of analysis and assessment of UMTS TDD opportunistic radio system with ad hoc behavior in coexistence with a UMTS FDD primary cellular networks.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.666-669
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• 2002

In this Research, we would like to perform optimal design by using theoretical equation and experimental equation for development of transmission and P.T.O on work vehicle with multi-function that is suited fruit cultures in my country. For the purpose of reducing development period about product and minimizing risk about design error, detail design and interference check are accomplished by FEM analysis and CAD software.