• Title/Summary/Keyword: Discovery Time

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Evaluation of a Sample-Pooling Technique in Estimating Bioavailability of a Compound for High-Throughput Lead Optimazation (혈장 시료 풀링을 통한 신약 후보물질의 흡수율 고효율 검색기법의 평가)

  • Yi, In-Kyong;Kuh, Hyo-Jeong;Chung, Suk-Jae;Lee, Min-Haw;Shim, Chang-Koo
    • Journal of Pharmaceutical Investigation
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    • v.30 no.3
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    • pp.191-199
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    • 2000
  • Genomics is providing targets faster than we can validate them and combinatorial chemistry is providing new chemical entities faster than we can screen them. Historically, the drug discovery cascade has been established as a sequential process initiated with a potency screening against a selected biological target. In this sequential process, pharmacokinetics was often regarded as a low-throughput activity. Typically, limited pharmacokinetics studies would be conducted prior to acceptance of a compound for safety evaluation and, as a result, compounds often failed to reach a clinical testing due to unfavorable pharmacokinetic characteristics. A new paradigm in drug discovery has emerged in which the entire sample collection is rapidly screened using robotized high-throughput assays at the outset of the program. Higher-throughput pharmacokinetics (HTPK) is being achieved through introduction of new techniques, including automation for sample preparation and new experimental approaches. A number of in vitro and in vivo methods are being developed for the HTPK. In vitro studies, in which many cell lines are used to screen absorption and metabolism, are generally faster than in vivo screening, and, in this sense, in vitro screening is often considered as a real HTPK. Despite the elegance of the in vitro models, however, in vivo screenings are always essential for the final confirmation. Among these in vivo methods, cassette dosing technique, is believed the methods that is applicable in the screening of pharmacokinetics of many compounds at a time. The widespread use of liquid chromatography (LC) interfaced to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) allowed the feasibility of the cassette dosing technique. Another approach to increase the throughput of in vivo screening of pharmacokinetics is to reduce the number of sample analysis. Two common approaches are used for this purpose. First, samples from identical study designs but that contain different drug candidate can be pooled to produce single set of samples, thus, reducing sample to be analyzed. Second, for a single test compound, serial plasma samples can be pooled to produce a single composite sample for analysis. In this review, we validated the issue whether the second method can be applied to practical screening of in vivo pharmacokinetics using data from seven of our previous bioequivalence studies. For a given drug, equally spaced serial plasma samples were pooled to achieve a 'Pooled Concentration' for the drug. An area under the plasma drug concentration-time curve (AUC) was then calculated theoretically using the pooled concentration and the predicted AUC value was statistically compared with the traditionally calculated AUC value. The comparison revealed that the sample pooling method generated reasonably accurate AUC values when compared with those obtained by the traditional approach. It is especially noteworthy that the accuracy was obtained by the analysis of only one sample instead of analyses of a number of samples that necessitates a significant man-power and time. Thus, we propose the sample pooling method as an alternative to in vivo pharmacokinetic approach in the selection potential lead(s) from combinatorial libraries.

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Adaptation Methods for a Probabilistic Fuzzy Rule-based Learning System (확률적 퍼지 룰 기반 학습 시스템의 적응 방법)

  • Lee, Hyeong-Uk;Byeon, Jeung-Nam
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.11a
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    • pp.223-226
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    • 2007
  • 지식 발견 (knowledge discovery)의 관점에서, 단기간 동안 취득된 데이터 패턴을 학습하고자 하는 경우 데이터에 비일관적인(inconsistent) 패턴이 포함되어 있다면 확률적 퍼지 룰(probabilistic fuzzy rule) 기반의 지식 표현 방법 및 적절한 학습 알고리즘을 이용하여 효과적으로 다룰 수 있다. 하지만 장기간 동안 지속적으로 얻어진 데이터 패턴을 다루고자 하는 경우, 데이터가 시변(time-varying) 특성을 가지고 있으면 기존에 추출된 지식을 변화된 데이터에 활용하기 어렵게 된다. 때문에 이러한 데이터를 다루는 학습 시스템에는 패턴의 변화에 맞추어 갈 수 있는 지속적인 적응력(adaptivity)이 요구된다. 본 논문에서는 이러한 적응성의 측면을 고려하여 평생 학습(life-long learning)의 관점 에 서 확률적 퍼지 룰 기반의 학습 시스템에 적용될 수 있는 두 가지 형태의 적응 방법에 대해서 설명하도록 한다.

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A Design and Implementation of IPv6 LAN (IPv6 프로토콜 LAN 설계 및 구축)

  • 김상범;김두석
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.481-484
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    • 2000
  • In this paper, we describe the design and implementation of IPv6 LAN. The legacy protocol for Internet is IPv4(IP version 4). The ability of IPv4 is not enough for modern real time multimedia communication services. So IPv6(IP version 6) protocol was suggested to resolve the problems of IPv4. We implemented IPv6 LAN using sTLA(sub Top Level Aggregation identifier) address and KOREN(KOrea Research and Experimental Network). Our IPv6 LAN is connected with 6TAP(Chicago), WIDE(Tokyo), and SingAREN(Singapore). We used a dedicated router, Windows 2000 PC host FreeBSD PC host, Solaris 7 workstation and Solaris 8 workstation for IPv6 NDP(Neighbor Discovery Protocol) protocol test. To support all data services including voice and video, IP protocol should be enhanced because the characteristics of modern network services are requiring QoS(Quality of Service) functions, auto-configuration, security, mobility and so on. So a new IP protocol, IPv6, has been developing to meet the requirements. In this paper, we introduce the implementation method and configuration information of IPv6 LAN.

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Discovery of Pachynematus itoi Okutani (Hymenoptera: Tenthredinidae) infesting Larix kaempferi(Lamb.) Carriere from Korea (낙엽송을 가해하는 한국미기록 낙엽송잎벌(신칭)(벌목, 잎벌과)의 발견)

  • Park, Ji-Doo;Shinohara, Akihiko;Park, Il-Kwon;Shin, Sang-Chul;Byun, Bong-Kyu
    • Korean journal of applied entomology
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    • v.46 no.1 s.145
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    • pp.1-4
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    • 2007
  • Pachynematus itoi Okutani, belonging to the family Tenthredinidae(Hymenoptera), which infested Larix kaempferi(Lamb.) Carriere in the middle areas of Korea, is reported for the first time from Korea. External characteristics of adults are briefly redescribed with photos. Also its damages and bionomic data are discussed.

Efficient Mining of Interesting Patterns in Large Biological Sequences

  • Rashid, Md. Mamunur;Karim, Md. Rezaul;Jeong, Byeong-Soo;Choi, Ho-Jin
    • Genomics & Informatics
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    • v.10 no.1
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    • pp.44-50
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    • 2012
  • Pattern discovery in biological sequences (e.g., DNA sequences) is one of the most challenging tasks in computational biology and bioinformatics. So far, in most approaches, the number of occurrences is a major measure of determining whether a pattern is interesting or not. In computational biology, however, a pattern that is not frequent may still be considered very informative if its actual support frequency exceeds the prior expectation by a large margin. In this paper, we propose a new interesting measure that can provide meaningful biological information. We also propose an efficient index-based method for mining such interesting patterns. Experimental results show that our approach can find interesting patterns within an acceptable computation time.

Dye-Sensitized Metal Oxide Nanostructures and Their Photoelectrochemical Properties

  • Park, Nam-Gyu
    • Journal of the Korean Electrochemical Society
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    • v.13 no.1
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    • pp.10-18
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    • 2010
  • Nanostructured metal oxides have been widely used in the research fields of photoelectrochemistry, photochemistry and opto-electronics. Dye-sensitized solar cell is a typical example because it is based on nanostructured $TiO_2$. Since the discovery of dye-sensitized solar cell in 1991, it has been considered as a promising photovoltaic solar cell because of low-cost, colorful and semitransparent characteristics. Unlike p-n junction type solar cell, dye-sensitized solar cell is photoelectrochemical type and is usually composed of the dye-adsorbed nanocrystalline metal oxide, the iodide/tri-iodide redox electrolyte and the Pt and/or carbon counter electrode. Among the studied issues to improve efficiency of dye-sensitized solar cell, nanoengineering technologies of metal oxide particle and film have been reviewed in terms of improving optical property, electron transport and electron life time.

Development of Active Data Mining Component for Web Database Applications (웹 데이터베이스 응용을 위한 액티브데이터마이닝 컴포넌트 개발)

  • Choi, Yong-Goo
    • Journal of Information Technology Applications and Management
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    • v.15 no.2
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    • pp.1-14
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    • 2008
  • The distinguished prosperity of information technologies from great progress of e-business during the last decade has unavoidably made software development for active data mining to discovery hidden predictive information regarding business trends and behavior from vary large databases. Therefore this paper develops an active mining object(ADMO) component, which provides real-time predictive information from web databases. The ADMO component is to extended ADO(ActiveX Data Object) component to active data mining component based on COM(Component Object Model) for application program interface(API). ADMO component development made use of window script component(WSC) based on XML(eXtensible Markup Language). For the purpose of investigating the application environments and the practical schemes of the ADMO component, experiments for diverse practical applications were performed in this paper. As a result, ADMO component confirmed that it could effectively extract the analytic information of classification and aggregation from vary large databases for Web services.

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Indicator Microorganisms Used as Fecal Contamination in Aquatic Environments (수계환경에서 분변성 오염의 지표로 사용되는 미생물들)

  • 이건형
    • Korean Journal of Environmental Biology
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    • v.20 no.3
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    • pp.189-196
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    • 2002
  • The direct detection of intestinal pathogens and viruses often requires costly, tedious, and time-consuming procedures. These requirements developed a test to show that the water was contaminated with sewage-borne pathogens by assessing the hygienic quality of water based on indicator microorganisms whose presence indicates that pathogenic microorganisms may also be present. Various groups of microorganisms have been suggested and used as indicator microorganisms. Proposed and commonly used microbial indicators are total coliforms, fecal coliforms, fecal streptococci, Clostridium perfringens, heterotrophic plate count, bacteriophage, and so on. Unfortunately, most, if not all, of these indicators are not ideal because of the sensitivity and resistance to environment stresses and disinfection. However, the development of gene probes and PCR technology may give hope for the discovery of rapid and simple methods toy detecting small number of fecal pathogens in various environments.

Identification of Differentially Expressed Genes by cDNA-AFLP in Magnaporthe oryzae

  • Chi, Myoung-Hwan;Park, Sook-Young
    • Research in Plant Disease
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    • v.25 no.4
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    • pp.205-212
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    • 2019
  • Analysis of differentially expressed genes has assisted discovery of gene sets involved in particular biological processes. The purpose of this study was to identify genes involved in appressorium formation in the rice blast fungus Magnaporthe oryzae via analysis of cDNA-amplified fragment length polymorphisms. Amplification of appressorial and vegetative mycelial cDNAs using 28 primer combinations generated over 200 differentially expressed transcript-derived fragments (TDFs). TDFs were excised from gels, re-amplified by PCR, cloned, and sequenced. Forty-four of 52 clones analyzed corresponded to 42 genes. Quantitative real-time PCR showed that expression of 23 genes was up-regulated during appressorium formation, one of which was the MCK1 gene that had been shown to be involved in appressorium formation. This study will be providing valuable resources for identifying the genes such as pathogenicity-related genes in M. oryzae.

Optimal Release Policy for a Software System using Number of Software Test (소프트웨어의 테스트 회수(回數)를 이용한 최적방출정책(最適放出政策))

  • Go, Hyeon-U;Hwang, Ui-Cheol
    • Journal of Korean Society for Quality Management
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    • v.17 no.2
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    • pp.27-35
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    • 1989
  • Software developers often allocate a significant amount of effort to software testing. But for most business-related software system it is natural to expect the continued discovery of defects after the software system is released into field. Such defects are usually very expensive to fix and have the potential to cause great damages to the users. It is important to stop testing the software and release it to the users at the correct time. In this paper, we propose the determination of the optimal number of software test oy minimizing a total expected software cost. A numerical example is used when the criterion is the expected profit. The result indicates that the proposed software release policy based on the number of software test can be a good alternative to the existing policy.

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