• Title/Summary/Keyword: Modification

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Germline Modification and Engineering in Avian Species

  • Lee, Hong Jo;Lee, Hyung Chul;Han, Jae Yong
    • Molecules and Cells
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    • v.38 no.9
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    • pp.743-749
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    • 2015
  • Production of genome-edited animals using germline-competent cells and genetic modification tools has provided opportunities for investigation of biological mechanisms in various organisms. The recently reported programmed genome editing technology that can induce gene modification at a target locus in an efficient and precise manner facilitates establishment of animal models. In this regard, the demand for genome-edited avian species, which are some of the most suitable model animals due to their unique embryonic development, has also increased. Furthermore, germline chimera production through longterm culture of chicken primordial germ cells (PGCs) has facilitated research on production of genome-edited chickens. Thus, use of avian germline modification is promising for development of novel avian models for research of disease control and various biological mechanisms. Here, we discuss recent progress in genome modification technology in avian species and its applications and future strategies.

Mechanisms involved in modification of film structure and properties in ICP assisted dc and pulsed dc sputtering

  • Kusano, Eiji
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.59.2-59.2
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    • 2015
  • Modification of film structure and properties in inductively-coupled plasma (ICP) assisted dc and pulsed dc sputtering has been reported by Oya and Kusano [1] and by Sakamoto, Kusano, and Matsuda [2], showing drastic changes in films structure and properties by the ICP assistance in particular to the pulsed dc discharge. Although mechanisms involved in the modification has been reported to be the increase in energy transferred to the substrate, details of effects of low-energy ion bombardment on the modification and origin of an anomalous increase in the ion quantity by the ICP assistance to the pulsed dc discharge have not been discussed. In this presentation, mechanisms involved in film structure and property modification in ICP assisted dc and pulsed dc sputtering, in which a number of low-energy ions are formed, will be discussed based on ion energy distribution as well as effectiveness of energy transfer to the substrate by low energy particles [3]. The results discussed in this presentation will emphasize the fact that the energetic particles playing an important role in the film structure modification are those to be deposited, but not those of inert gas, when their energies range in less than 100 eV in the pressure range of magnetron sputtering.

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Improvement of Rolling Force Estimation by Modificaiton Function for Hot Steel Strip Rolling Process (보정함수를 이용한 강판의 열간 압연하중 예측 정도향상)

  • 문영훈;이경종;이필종;이준정
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1193-1201
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    • 1993
  • A new deformation resistance model for hot steel strip rolling process was formulated to improve the accuracy of roll force estimation. To improve the existing deformation resistance model more precisely, a modification function was introduced in this study. For the modification function, several factors considering material and operational conditions have been investigated and the optimal modification function was determined under the principle of minimum variability. The newly formulated modification function was applied to the deformation resistance model for ultra-low carbon steel and showed improved accuracy with about 30% decrease in terms of standard deviation of predicted roll force values against measured ones.

Chemical Modification of the Biodegradative Threonine Dehydratase from Serratia marcescens with Arginine and Lysine Modification Reagents

  • Choi, Byung-Bum;Kim, Soung-Soo
    • BMB Reports
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    • v.28 no.2
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    • pp.124-128
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    • 1995
  • Biodegradative threonine dehydratase purified from Serratia marcescens ATCC 25419 was inactivated by the arginine specific modification reagent, phenylglyoxal (PGO) and the lysine modification reagent, pyridoxal 5'-phosphate (PLP). The inactivation by PGO was protected by L-threonine and L-serine. The second order rate constant for the inactivation of the enzyme by PGO was calculated to be 136 $M^{-1}min^{-1}$. The reaction order with respect to PGO was 0.83. The inactivation of the enzyme by PGO was reversed upon addition of excess hydroxylamine. The inactivation of the enzyme by PLP was protected by L-threonine, L-serine, and a-aminobutyrate. The second order rate constant for the inactivation of the enzyme by PLP was 157 $M^{-1}min^{-1}$ and the order of reaction with respect to PLP was 1.0. The inactivation of the enzyme by PLP was reversed upon addition of excess acetic anhydride. Other chemical modification reagents such as N-ethylmaleimide, 5,5'-dithiobis (2-nitrobenzoate), iodoacetamide, sodium azide, phenylmethyl sulfonylfluoride and diethylpyrocarbonate had no effect on the enzyme activity. These results suggest that essential arginine and lysine residues may be located at or near the active site.

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School Uniform Modification and Fashion Accessory Wearing Behavior of High School Students (고등학생의 교복변형과 패션 액세서리 착용행동)

  • Kim, Yong-Sook;Jeon, Chae-Ryeong
    • Korean Journal of Human Ecology
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    • v.16 no.3
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    • pp.587-599
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    • 2007
  • There are many students who modify their uniforms and wear fashion accessories to pursue their individualities. The objectives of this research were to identify school uniform modification and fashion accessory wearing behavior of high school students. The results were as follows; 1. High school students considered that the uniform was desirable because the uniform showed identity best, but many students complained that the uniform was uncomfortable in activity. The most accessory used for the uniform was the cellular phone handle. 2. The uniform modification behavior was highly distinguishable at the coeducational school, the vocational school, and the art or physical school. They modified their uniform to pursuit slim and individuality. The uniform modification was for the beauty aspect more rather than practical aspect of uniform, and was proportional to the degree of the appearance, and in case of pants, the length and width of the pants showed increasing trend compared to the past. They considered accessory wearing as a compensational expression of the most of students who were not actively behaving on the uniform modification.

Tooth modification of helical gears for minimization of vibration and noise

  • Chong, Tae-Hyong;Myong, Jae-Hyong;Kim, Ki-Tae
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.4
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    • pp.5-11
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    • 2001
  • Vibration and noise of gears is doc to the transmission error and the vibration exciting force caused by the periodically alternating tooth stiffness. Transmission error is the rotation delay between driving and driven gear caused by manufacturing error, alignment error in assembly and so on. Tooth stiffness changes with the proceeding mesh of teeth. The purpose of this study is to develop how to calculate simultaneously the optimum amounts of tooth profile modification. end relief and crowning by minimizing the vibration exciting force of helical gears. We estimate the vibration exciting force by the meshing analysis of gears. Formulated constraints of this problem consist of contact ratio and strengths of gear teeth such as tooth bending strength, surface durability, and scoring. ADS(Automated Design Synthesis) is used as an optimization tool. We also investigate the relation between the aspect ratio and the optimum values of tooth modification. The proposed method can calculate the optimum amount of tooth modification automatically and is expected to be practically useful to resolve the problem of vibration of helical gears.

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Effect of NH3 plasma on thin-film composite membrane: Relationship of membrane and plasma properties

  • Kim, Eun-Sik;Deng, Baolin
    • Membrane and Water Treatment
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    • v.4 no.2
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    • pp.109-126
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    • 2013
  • Surface modification by low-pressure ammonia ($NH_3$) plasma on commercial thin-film composite (TFC) membranes was investigated in this study. Surface hydrophilicity, total surface free energy, ion exchange capacity (IEC) and zeta (${\zeta}$)-potentials were determined for the TFC membranes. Qualitative and quantitative analyses of the membrane surface chemistry were conducted by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy. Results showed that the $NH_3$ plasma treatment increased the surface hydrophilicity, in particular at a plasma treatment time longer than 5 min at 50 W of plasma power. Total surface free energy was influenced by the basic polar components introduced by the $NH_3$ plasma, and isoelectric point (IEP) was shifted to higher pH region after the modification. A ten (10) min $NH_3$ plasma treatment at 90 W was found to be adequate for the TFC membrane modification, resulting in a membrane with better characteristics than the TFC membranes without the modification for water treatment. The thin-film chemistry (i.e., fully-aromatic and semi-aromatic nature in the interfacial polymerization) influenced the initial stage of plasma modification.

A Study on the estimation of an equivalent system of a local vibration system of a huge structure and the Optimum Structural Modification Method (거대 구조물의 국부진동계의 등가계 산출과 이를 이용한 최적구조변경법)

  • 박석주;황문주;오창근;김성우
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.04a
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    • pp.120-127
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    • 1998
  • It is very difficult to execute the vibration analysis of a huge strucutre, which takes up much time and expense. In this paper we intend to make the equivalent system of a local vibration system of a huge structure with a view to improving the dynamic characteristics and reducing time and expense. First of all, upper deck structure model is maded. And we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the upper deck structure model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. To make the equivalent system, we give boundary condition to sub-structure that want to be modified and execute the Sensitivity Analysis Method and the Optimum Structural Modification Method. And we execute the structural modification of the equivalent system.. The following can be found from this study. 1. The analytical results are generally coincident with each other. 2. The equivalent system of the superstructure model can be easily obtained using the sensitivity analysis metho and the optimum structural modification method. 3. The structural modification using the equivalent system can be obtained good results above 90% of object value.

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Attitudes toward Appearance and Body Satisfaction according to Uniform Modification Behavior of Middle and High School Girls (여중·고생들의 교복변형행동에 따른 외모에 대한 태도와 신체만족)

  • Park, Eunhee;Cho, Hyonju
    • Journal of Fashion Business
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    • v.19 no.4
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    • pp.168-182
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    • 2015
  • The purpose of this study is to classify students' attitudes towards uniform modification and analyze their subjective experience regarding appearance, and body satisfaction. Questionnaires were administered to 369 middle and high school girls living in Deagu Metropolitan City. Frequency, factor analysis, reliability analysis, correlation analysis, ${\chi}^2$-test, and t-test are all used for data analysis. Our findings are as follows. Two hundred thirty students (62.3%) agreed to modify their school uniforms to express their personalities and follow fashion trends. Motives for uniform modification had to do with social life, physical attractiveness, and practicality. Attitudes toward appearance are found to be shaped by appearance internalization, active management of appearance, appearance needs, social recognition, and conformity. The motives for uniform modification reveal a significant correlation with attitudes toward appearance. Uniform modification satisfaction differed depending on sub-variables of attitude toward appearance(active management of appearance, personalized appearance needs, social recognition, and body satisfaction, such as satisfaction with height and BMI). There was a significant difference in expression of intention for future plastic surgery depending on body image.

Modification of Solid Models Independent of Design Features (디자인 피쳐에 의존하지 않는 솔리드 모델의 수정)

  • Woo, Yoon-Hwan
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.2
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    • pp.131-138
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    • 2008
  • With the advancements of the Internet and CAD data translation techniques, more CAD models are transferred from a CAD system to another through the network and interoperability is getting a common word in the CAD industry. However, when a CAD model is translated for an incompatible system into a neutral format such as STEP or IGES, its precious feature information is lost. When this feature information is lost, the advantage of feature based modeling is not valid any longer, and modification for the model is purely dependent on geometric and topological manipulations. However, the capabilities of the existing methods to modify these feature-independent models are limited as the modification involves a topological change in the model. To address this issue, we present a volumetric method to modify the solid models in neutral format. First, this method selectively decomposes the solid model to separate the portion of interest called feature volume. Next, the designer modifies the feature volume without concerning a topological change. Finally, the feature volume is united with the original solid model to complete the modification process. The results of test cases are presented to attest the usefulness of the proposed method.