• Title/Summary/Keyword: critical means

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Computational Approaches for Structural and Functional Genomics

  • Brenner, Steven-E.
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2000.11a
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    • pp.17-20
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    • 2000
  • Structural genomics aims to provide a good experimental structure or computational model of every tractable protein in a complete genome. Underlying this goal is the immense value of protein structure, especially in permitting recognition of distant evolutionary relationships for proteins whose sequence analysis has failed to find any significant homolog. A considerable fraction of the genes in all sequenced genomes have no known function, and structure determination provides a direct means of revealing homology that may be used to infer their putative molecular function. The solved structures will be similarly useful for elucidating the biochemical or biophysical role of proteins that have been previously ascribed only phenotypic functions. More generally, knowledge of an increasingly complete repertoire of protein structures will aid structure prediction methods, improve understanding of protein structure, and ultimately lend insight into molecular interactions and pathways. We use computational methods to select families whose structures cannot be predicted and which are likely to be amenable to experimental characterization. Methods to be employed included modern sequence analysis and clustering algorithms. A critical component is consultation of the presage database for structural genomics, which records the community's experimental work underway and computational predictions. The protein families are ranked according to several criteria including taxonomic diversity and known functional information. Individual proteins, often homologs from hyperthermophiles, are selected from these families as targets for structure determination. The solved structures are examined for structural similarity to other proteins of known structure. Homologous proteins in sequence databases are computationally modeled, to provide a resource of protein structure models complementing the experimentally solved protein structures.

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Determinants of Information Technology Audit Quality: Evidence from Vietnam

  • NGUYEN, Anh Huu;HA, Hanh Hong;NGUYEN, Soa La
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.4
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    • pp.41-50
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    • 2020
  • The paper aims to investigate auditors, auditing firms and other external factors that affect quality of information technology audit in Vietnam. We conducted 2 types of data collections including direct and on survey. For direct survey, we sent directly to auditors at the training classes organized by State Securities Exchanges Commission. An online survey was established and Google doc link was provided to the Big4 and non-Big4 auditors. We received 138 survey responses in that 90 auditors came from Big4 and 48 auditors from non-Big4 firms. The data are analyzed using a factor analysis and compare means approaches to illustrate the potential IT audit quality factors and identify differences between two groups of auditors. The results show that independence and accounting knowledge and audit skills are the most important factors. And since external auditors perform many assurance services, the independence is critical. The result also shows that the auditors need to have enough competent and professional skills when conducting an audit, especially within an IT environment that requires high quality. The findings suggest a similar pattern of two groups in the context of Vietnam and some factors of auditors and auditing firms appear to have a statistically significant impact on quality of IT audit.

Analysis on the Minimum Separation Distance for Spectrum Sharing between IMT and FSS systems in C Band (C 대역에서 IMT와 FSS 시스템간 주파수 공유를 위한 최소 이격거리 분석)

  • Kang, Young-Heung
    • Journal of Advanced Navigation Technology
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    • v.13 no.6
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    • pp.907-915
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    • 2009
  • Spectrum sharing between wireless systems becomes a critical issue due to emerging new technologies and spectrum shortage. Recently, IMT system has been allocated in the same frequency C band (3400-4200MHz) along with FSS services on co-primary basis, which means that harmful interference probability may be inspired. In this paper, to estimate the spectrum sharing between IMT and FSS systems, the minimum separation distances have been evaluated considering major factors such as the clutter loss in some areas and the elevation angle of FSS earth station, and using I/N=-10dB which is fundamental criterion for coexistence.

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A Study on Electrochemical Evaluation Method of Toughness Degradation for 12%Cr Steel (II) (12%Cr강 인성열화도의 전기화학적 평가법에 대한 연구(II))

  • Kim, Chang-Hui;Seo, Hyun-Uk;Yoon, Kee-Bong;Park, Ki-Sung;Kim, Seoung-Tae
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.268-273
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    • 2001
  • Fossil power plants operated in high temperature condition are composed of components such as turbine, boiler, and piping system. Among these components, turbine blades made with 12%Cr steel operate at a temperature above $500^{\circ}C$. Due to the long term service, turbine blades experience material degradation manifested by change in mechanical and microstructural properties. The need to make life assessment and to evaluate material degradation of turbine blade is strongly required but in reality, there is a lack of knowledge in defining failure mechanism and fundamental data for this component. Therefore, in making life assessment of turbine blade, evaluation of material degradation must be a priority. For this purpose, evaluation of toughness degradation is very important. The major cause of toughness degradation in 12Cr turbine blade is reported to be critical corrosion pitting induced by segregation of impurity elements(P etc.), coarsening of carbide, and corrosion, but the of materials for in-service application. In this study, the purpose of research is focused on evaluating toughness degradation with respect to operation time for 12%Cr steel turbine blade under high temperature steam environment and quantitatively detecting the degradation properties which is the cause of toughness degradation by means of non-destructive method, electrochemical polarization.

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The Improvement of MTG Process for Preparation of YBCO superconductor

  • Fan, Zhanguo;Shan, Yuqiao;Soh, Daewha
    • Proceedings of the Materials Research Society of Korea Conference
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    • 1996.11a
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    • pp.174-176
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    • 1996
  • In the YBCO matrix, 10wt.% Y$_2$BaCuO$\_$5/ (211 phase) was added, the final 211 content of YBCO made by MTG process could reach about 20wt.% which was the optimum value for the critical current density. And also 10wt.% Ag was added in the matrix of YBCO, which was nearly about the saturate solubility of silver in textured YBCO. SmBaCuO crystal was grown by the melted-condensed process. A 5${\times}$5${\times}$2㎣ single crystal of SmBaCuO was used to be the seed in the preparation of YBCO. It was proved the orientation of YBCO was the same as the orientation of the SmBaCuO seed. The oxygen absorption of bulk oriented YBCO was studied and the heat treatment of oxygen absorption would be in flowing oxygen, at 400$^{\circ}C$ for about 24 hours. the magnetic hysteresis loops were measured by Vibrating Smaple Magnetometer and the J$\_$c/ was calcuated by means of Bean's model.

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Analysis of Impedance and Stray Inductance for Pulsed Plasma Reactor (펄스 플라스마 반응기에 대한 임피던스 및 누설 인덕턴스 분석)

  • Choi, Young-Wook;Lee, Hong-Sik;Rim, Geun-Hie;Kim, Tae-Hee;Kim, Jong-Wha;Jang, Gil-Hong;Shin, Wan-Ho;Song, Young-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.4
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    • pp.253-260
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    • 1999
  • In this paper, the impedance characteristic of wire-plate pulsed plasma reactor was investigated by experiment. The experiment have carried out under the several conditions of voltage, wire length and wire-plate distance. The impedance of reactor wad decreased with increasing voltage and wire length. The nature of discharge in reactor was changed from streamer corona to spark with increasing incident energy, from which we understood the critical energy density between the two discharges. Fromthis experiment, we proposed the method for the impedance matching between pulse generator and pulsed plasma reactor. Additionally, we succeeded in the analysis ofstray inductance of 0.5MW reactor using EMTP (ElectroMagnetic Transients Program). This means that EMTP is also useful for the analysis of inevitable stray inductance of forthcoming a large scale reactor.

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NuDE 2.0: A Formal Method-based Software Development, Verification and Safety Analysis Environment for Digital I&Cs in NPPs

  • Kim, Eui-Sub;Lee, Dong-Ah;Jung, Sejin;Yoo, Junbeom;Choi, Jong-Gyun;Lee, Jang-Soo
    • Journal of Computing Science and Engineering
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    • v.11 no.1
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    • pp.9-23
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    • 2017
  • NuDE 2.0 (Nuclear Development Environment 2.0) is a formal-method-based software development, verification and safety analysis environment for safety-critical digital I&Cs implemented with programmable logic controller (PLC) and field-programmable gate array (FPGA). It simultaneously develops PLC/FPGA software implementations from one requirement/design specification and also helps most of the development, verification, and safety analysis to be performed mechanically and in sequence. The NuDE 2.0 now consists of 25 CASE tools and also includes an in-depth solution for indirect commercial off-the-shelf (COTS) software dedication of new FPGA-based digital I&Cs. We expect that the NuDE 2.0 will be widely used as a means of diversifying software design/implementation and model-based software development methodology.

Effects of Water Deficit on Leaf Growth during Vegetative Growth Period in Soybean

  • Kim, Wook-Han;Hong, Byung-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.1
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    • pp.1-5
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    • 2000
  • Leaf area is critical for crop light interception, and thereby has a substantial influence on crop yield. This experiment was conducted to characterize the development of soybean [Glycine max (L.) Merr.] leaf area. Plastochron index and leaf relative growth rate of Jackson was contrasted with the PI416937, which also has demonstrated tolerance to drought. First, plastochron ratio (PR) and plastochron index (PI) were evaluated in greenhouse to compare the leaf growth rate between two genotypes under well-watered condition. There was reasonable constancy of PR between two genotypes. The PR means of Jackson and PI416937 were 0.41 and 0.44, respectively. A fairly smooth increase of PI during vegetative stage was observed. Second, the relative growth rates were graphed against leaf area, normalized with respect to final leaf area, under well-watered and water-deficit conditions. Leaf growth was sustained longer in well-watered condition than water-deficit condition and there was a sizable proportion of leaves which was ceased earlier their growth in water-deficit condition compared to well-watered condition. The leaf relative growth rate of Jackson until leaves had completed at 45% of their growth during water deficit period was higher than that of PI416937.

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Studies on the Synthesis and Surface Activities of Naphthionic Acid Derivatives (나프티온산 유도체의 합성 및 계면활성에 관한 연구)

  • Sohn, Joo-Hwan;Park, Jeong-Hwan;Kim, Yu-Ok
    • Journal of the Korean Applied Science and Technology
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    • v.3 no.1
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    • pp.65-71
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    • 1986
  • Four amphoteric surfactants, 1-(N-alkyl-N,N-dimethyl ammonio)-4-naphthalene sulfonates, were prepared by the alkylation of 1-(N,N-dimethylamino)-4,naphthalene sulfonic acid with chloroalkanes such as 1-decylchloride, 1-tetradecyl chloride and 1-hexadecyl chloride. These quaternary ammonium compounds such as 1-(N-decyl-N, N-dimethylammonio)-4-naphthalene sulfonate, 1-(N-dodecyl-N,N-dimethylammonio)-4-naphthalene sulfonate, 1-(N-tetradecyl-N,N-dimethylammonio)-4-naphthalene sulfonate and 1-(N-hexadecyl-N,N-dimethylammonio)-4-naphthalene sulfonate could be separated by means of thin layes chromatography and column chromatography. The surface chemical properties such as surface tension, foaming power, foam stability, wetting efficiency and solubilizing effect for these four compounds were measured. Also critical micelle concentration and hydrophilic-lipophilic balance(HLB) were evaluated. These compounds showed good surface as O/W type emulsifying agent and detergent.

Effect of Fibroblast Growth Factor-2 on Migration and Proteinases Secretion of Human Umbilical Vein Endothelial Cells

  • Oh, In-Suk;Kim, Hwan-Gyu
    • Journal of Microbiology and Biotechnology
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    • v.14 no.2
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    • pp.379-384
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    • 2004
  • Fibroblast growth factor-2 (FGF-2) is known to modulate numerous cellular functions in various cell types, including cell proliferation, differentiation, survival, adhesion, migration, and motility, and also in processes such as wound healing, angiogenesis, and vasculogenesis. FGF-2 regulates the expression of several molecules thought to mediate critical steps during angiogenesis. This study examines the mechanisms underlying FGF-2-induced cell migration, using human umbilical vein endothelial cells (HUVECs). FGF-2 induced the nondirectional and directional migration of endothelial cells, which are inhibited by MMPs and plasmin inhibitors, and induced the secretion of matrix metalloproteinase-3 (MMP3) and MMP-9, but not MMP-l and MMP-2. FGF-2 also induced the secretion of the tissue inhibitor of metalloproteinase-l (TIMP-I), but not of TIMP- 2. Also, the pan-PKC inhibitor inhibited FGF-2-induced MMP-9 secretion. It is, therefore, suggested that FGF-2 induces the migration of cultured endothelial cells by means of increased MMPs and plasmin secretion. Furthermore, FGF-2 may increase MMP-9 secretion by activating the PKC pathway.