• Title/Summary/Keyword: Bottlenecks

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Bottlenecks of conventional approaches and complemental expectations of molecular biology in variental improvement of vegetable crops (채소 품종 개량에 있어서 전통기술의 한계 극복을 위한 분자유전학의 역할 기대)

  • 윤진영;오대근
    • Proceedings of the Botanical Society of Korea Conference
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    • 1995.07a
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    • pp.109-130
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    • 1995
  • 지난 반세기간에 우리나라에 채소 육종은 주요 채소의 주년공급을 가능하게 하였으며, 토지 생산성의 향상, 상품화율의 증대, 품질의 향상 등의 면에서도 괄목할 만한 성과를 거두었고 인공교잡은 물론이고 웅성불임성과 자가불화합성의 활용에 의한 1대잡종 품종의 일반화로 채소 산업의 발전에 크게 기여하였다. 앞으로는 기왕의 업적을 심화시키는 한편, 생산비를 절감하기 위한 생력화, 기계화 재배용 품종 및 내제초제성 품종의 개발 환경보호 및 식품안정성의 확보를 위한 내병층성 품종 개발, 수출시장과 다양화하는 국내의 시장기호에 대응하고 가공 식품의 표준화된 품질관리를 지원할 수 있도록 품질 면에서의 개량과 신작물 또는 신생태형 품종의 개발에도 더욱 노력이 필요하다. 이러한 육종목표를 달성하기 위한 유전자원의 확보는 더욱 어려워질 것이며 유전 양식이 복잡하고, 환경요인의 작용이 상대적으로 크기 때문에 전통적인 육종 방법만으로는 목표달성에 필요한 인적, 물적, 시간적 소요가 훨씬 증가될 전망이다. 유전변이의 창성 및 확대, 유용 대립인자의 도입, 동정 및 선발, 그리고 종자생산을 위한 자가 불화합성 및 웅성불임성과 개화·수정 관련 유전인자의 발현 조절에 분자유전학의 보완적 역할이 기대되며 이렇게 되면 전통육종과 분자유전학간의 잡종강세로 품종 개량의 효율은 크게 높아질 것이다.

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Yeast as a Touchstone in Post-genomic Research: Strategies for Integrative Analysis in Functional Genomics

  • Castrillo, Juan I.;Oliver, Stephen G.
    • BMB Reports
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    • v.37 no.1
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    • pp.93-106
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    • 2004
  • The new complexity arising from the genome sequencing projects requires new comprehensive post-genomic strategies: advanced studies in regulatory mechanisms, application of new high-throughput technologies at a genome-wide scale, at the different levels of cellular complexity (genome, transcriptome, proteome and metabolome), efficient analysis of the results, and application of new bioinformatic methods in an integrative or systems biology perspective. This can be accomplished in studies with model organisms under controlled conditions. In this review a perspective of the favourable characteristics of yeast as a touchstone model in post-genomic research is presented. The state-of-the art, latest advances in the field and bottlenecks, new strategies, new regulatory mechanisms, applications (patents) and high-throughput technologies, most of them being developed and validated in yeast, are presented. The optimal characteristics of yeast as a well-defined system for comprehensive studies under controlled conditions makes it a perfect model to be used in integrative, 'systems biology' studies to get new insights into the mechanisms of regulation (regulatory networks) responsible of specific phenotypes under particular environmental conditions, to be applied to more complex organisms (e.g. plants, human).

Parallel processing in structural reliability

  • Pellissetti, M.F.
    • Structural Engineering and Mechanics
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    • v.32 no.1
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    • pp.95-126
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    • 2009
  • The present contribution addresses the parallelization of advanced simulation methods for structural reliability analysis, which have recently been developed for large-scale structures with a high number of uncertain parameters. In particular, the Line Sampling method and the Subset Simulation method are considered. The proposed parallel algorithms exploit the parallelism associated with the possibility to simultaneously perform independent FE analyses. For the Line Sampling method a parallelization scheme is proposed both for the actual sampling process, and for the statistical gradient estimation method used to identify the so-called important direction of the Line Sampling scheme. Two parallelization strategies are investigated for the Subset Simulation method: the first one consists in the embarrassingly parallel advancement of distinct Markov chains; in this case the speedup is bounded by the number of chains advanced simultaneously. The second parallel Subset Simulation algorithm utilizes the concept of speculative computing. Speedup measurements in context with the FE model of a multistory building (24,000 DOFs) show the reduction of the wall-clock time to a very viable amount (<10 minutes for Line Sampling and ${\approx}$ 1 hour for Subset Simulation). The measurements, conducted on clusters of multi-core nodes, also indicate a strong sensitivity of the parallel performance to the load level of the nodes, in terms of the number of simultaneously used cores. This performance degradation is related to memory bottlenecks during the modal analysis required during each FE analysis.

Logistical Simulation for On-site Concrete Waste Management in Decommissioning

  • Lee, Eui-Taek;Kessel, David S.;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.4
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    • pp.389-403
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    • 2019
  • Large amounts of concrete waste are likely to arise from the decommissioning of a Kori-1 nuclear power plant. Several studies have been conducted on decommissioning concrete waste in recent decades, however, they have been limited to contaminated concrete issues or were small pilot-scale experiments. This study constructed two industrial-scale models of on-site concrete waste management for clean as well as contaminated concrete. To evaluate the performance of both the models, simulations were conducted using the Flexsim software. The concrete particle size distribution of Kori-1 and concrete processor properties based on widely used construction equipment were used as sources of input data for the simulations. It was observed that it may take over two years to complete the on-site concrete management processes owing to the performance of existing processors. In addition, it was demonstrated that it is essential to identify bottlenecks in the system and enhance the performance of the relevant processors to avoid delays of the decommissioning schedule. Our results suggest that this novel approach can contribute to developing schedules or expediting delayed activities in the Kori-1 decommissioning project.

A Study on Probabilistic Reliability Evaluation by Using PRA (PRA를 이용한 확률론적 신뢰도 평가에 관한 연구)

  • Kwon, J.J.;Taan, T.T.;Jeong, S.H.;Bo, Shi;Choi, J.S.;Cha, J.M.;Yoon, Y.T.;Choi, H.S.;Jeon, D.H.
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.27-29
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    • 2006
  • This paper deals with the application of the concept of POM to analysis of power system behavior and describes a practical method of PRA for KEPCO system. This paper presents not only marginal power flow evaluation of KEPCO system in view point of physical and operation mode by using Physical and Operational Margins (POM Ver. 2.2), which is developed by V&R Energy System Research, but also by using Probabilistic Reliability Assessment (PRA Ver.3.1), which is developed by EPRI. The ability of the method to provide insights on root causes, weak points and regional causes and effects was shown. The approach offers fast and accurate determination of bottlenecks in the transmission network and optimal mitigation measures to alleviate the identified violations.

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Toward A Reusable Knowledge Based System

  • Yoo, Young-Dong
    • The Journal of Information Systems
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    • v.3
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    • pp.71-82
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    • 1994
  • Knowledge acquisition, maintenance of knowledge base, and validation and verification of knowledge are the addressed bottlenecks of building successful knowledge based systems. Along with the increment of interesting in the knowledge based systems, the organization needs to develop a new one although it has a similar one. This causes several serious problems including knowledge redundancy and maintenance of knowledge base. This paper present three models of the reusable knowledge base which might be the solution to the above problem. Three models are : 1) multiple knowledge bases for a single AI application, 2) multiple knowledge bases for multiple AI applications, 3) a single knowledge base for multiple AI applications. A new approach to build such a reusable knowledge base in a homogeneous environment is presented. Our model combines the essential object-oriented techniques with rules in a consistent manner. Important aspects of applying object-oriented techniques to AI are discussed (inheritance, encapsulation, message passing), and some potential problems in building an AI application (decomposition technique of knowledge, search time, and heterogeneous environment) are pointed out. The models of a reusable knowledge base provide several amenities : 1) reduce the knowledge redundancy, 2) reduce the effort of maintenance of the knowledge base, 3) reuse the resource of the multiple domain knowledge bases, 4) reduce the development time.

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A Study on the NAS Storage-based Data Distributed Processing System Algorithm (NAS 스토리지 기반의 데이터 분산처리 시스템 알고리즘에 관한 연구)

  • Jang, Jae-Myung;Kang, Hee-beom;Jeong, Nahk-ju;Jung, Hoe-kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.643-645
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    • 2015
  • Real life has been actively utilizing storage from anywhere automobiles and Aviation field etc to the development of storage. Recent Big Data is stored as a number of data storage and data distribution processing emerged in research has been actively conducted to process the data. But many bottlenecks or processing speed slows down when you request the data at the same time a problem arises. In this paper consider should be used in the field of big data storing and processing large amounts of data, the process data more efficiently when the number of data request and data suggest that the weight-effective, manageable data processing system algorithm.

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The Structure Determination of La2/3-xLi3x1/3-2xTiO3 by the Powder Neutron and X-ray Diffraction

  • Kang, Eun-Tae;Kwon, Young-Jean
    • Journal of the Korean Ceramic Society
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    • v.40 no.6
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    • pp.513-518
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    • 2003
  • La/sub 2/3-x/Li/sub 3x/□/sub 1/3-2x/TiO₃ compounds with x=0.13 and 0.12 were prepared by slow cooling (x=0.13) and rapid quenching (x=0.12) into the liquid nitrogen after sintering at 1350℃ for 6 h. Their crystal structure has been determined by Rietveld refinement of both the powder neutron and X-ray diffraction data. From neutron diffraction data, we found that the main phase was not tetragonal (P4/mmm), but trigonal (R3cH). The refinement of neutron diffraction for the slow cooled samples were in a good agreement with a new model; a mixture of trigonal (R3cH, 45.7 wt%), tetragonal (p4/mmm, 37.0 wt%), and Li/sub 0.57/Ti/sub 0.86/O₂(pbnm, 17.2 wt%), but the quenched sample was found not to contain tetragonal (p4/mmm). X-ray diffraction data couldn't be well fitted because of the Poor scattering factor of lithium ions and the similar reflection patterns among trigonal (R3cH), tetragonal (p4/mmm), and cubic (Pm3m). We also knew that one transport bottlenecks is destroyed by one La vacancy in the case of trigonal (R3cH).

Analysis of I/O Response Time Throughout NVMe Driver Implementation Architectures (NVMe 드라이버 구현 방식에 따른 I/O 응답시간 분석)

  • Kang, Ingu;Joo, Yongsoo;Lim, Sung-Soo
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.3
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    • pp.139-147
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    • 2017
  • In recent years, non-volatile memory express (NVMe), a new host controller interface standard, has been adapted to overcome performance bottlenecks caused by the acceleration of solid state drives (SSD). Recently, performance breakthrough cases over AHCI based SATA SSDs by adapting NVMe based PCI Express (PCIe) SSD to servers and PCs have been reported. Furthermore, replacing legacy eMMC-flash storage with NVMe based storage is also considered for next generation of mobile devices such as smartphones. The Linux kernel includes drivers for NVMe support, and as the kernel version increases, the implementation of the NVMe driver code has changed. However, mobile devices are often equipped with older versions of Android operating systems (OSes), where the newest features of NVMe drivers are not available. Therefore, different features of different NVMe driver implementations are not well evaluated on Android OSes. In this paper, we analyze the response time of the NVMe driver for various Linux kernel version.

TCP-ROME: A Transport-Layer Parallel Streaming Protocol for Real-Time Online Multimedia Environments

  • Park, Ju-Won;Karrer, Roger P.;Kim, Jong-Won
    • Journal of Communications and Networks
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    • v.13 no.3
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    • pp.277-285
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    • 2011
  • Real-time multimedia streaming over the Internet is rapidly increasing with the popularity of user-created contents, Web 2.0 trends, and P2P (peer-to-peer) delivery support. While many homes today are broadband-enabled, the quality of experience (QoE) of a user is still limited due to frequent interruption of media playout. The vulnerability of TCP (transmission control protocol), the popular transport-layer protocol for streaming in practice, to the packet losses, retransmissions, and timeouts makes it hard to deliver a timely and persistent flow of packets for online multimedia contents. This paper presents TCP-real-time online multimedia environment (ROME), a novel transport-layer framework that allows the establishment and coordination of multiple many-to-one TCP connections. Between one client with multiple home addresses and multiple co-located or distributed servers, TCP-ROME increases the total throughput by aggregating the resources of multiple TCP connections. It also overcomes the bandwidth fluctuations of network bottlenecks by dynamically coordinating the streams of contents from multiple servers and by adapting the streaming rate of all connections to match the bandwidth requirement of the target video.