• 제목/요약/키워드: Coefficient Selection

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Development of Dynamic Balancing Techniques of a Rotor System Using Genetic Algorithm (유전자 알고리즘을 적용한 로터 시스템의 동적 밸런싱 기법 개발)

  • Kwon, Hyuck-Ju;Yu, Young-Hyun;Jung, Sung-Nam;Yun, Chul-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.12
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    • pp.1162-1169
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    • 2010
  • The dynamic balancing of a rotor system is needed to alleviate the imbalances originating from various sources encountered during blade manufacturing processes and environmental factors. This work aims at developing a comprehensive analysis system which consists of cumulative module of test D/B and selection of optimal control parameters. This system can be used for the dynamic balancing of helicopter rotors based on tracking results from the whirl tower test. For simplicity of the analysis, a linear relation is assumed between the balancing input parameters and the blade track responses leading to influence coefficients and thereby the rotor system identification is made. In addition, the balancing parameters of the individual blades are sought using the genetic algorithm and the effectiveness of the proposed method is demonstrated in comparison with the test results.

Effects of Soil Environment on the Growth of Pinus Thunbergii and Zelkova Serrata at the Reclaimed Seaside (임해매립지의 토양환경이 곰솔과 느티나무의 생육에 미치는 영향)

  • 김도균;장병문;김용식
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.4
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    • pp.9-20
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    • 2000
  • The purpose of thus paper is to provide the knowledge on preparing for the planting soil and planting method, and maintenance at the reclaimed seaside. Based on the collected data from the field work, the soil environment, the growth of height, inter-node, tree ring and roots of the two species had been analyzed. The determinant of soil factors, affecting the growth of trees, turned out to be six elements such as soil hardness, soil acidity, potassium, calcium, magnesium and total nitrogen. Because the variances of both growth of tree height and tree ring are greater than that of root, the growth characteristics of ground parts of the species by the individual tree species is more dynamical than those of underground parts. From the mean difference test the growth of height, root between Pinus thunbergii and Zelkova serrata, have been turned out to be statistically significant at 5 percent level. Pinus thunbergii is a sapling, so it grows faster than Zelkova serrata while Pinus thunbergii has better roots system than Zelkova serrata. From the correlation analysis, it showed the very strong correlation between tree height growth and potassim, while the lowest correlation coefficient was between soil hardness and potassim as 0.744. From the multiple regression analysis, both soil hardness and magnesium affect to the tree growth, soil hardness and potassium to the tree growth, potassium and calcium to the rot growth, respectively. Using this research results, we can be use the planting plan including revegetation, construction and maintenance of the reclaimed seaside. In the future, the planting method including the ground preparation and tree species selection for the reclaimed seaside should be accompanied in advanced through the soil survey and relevant analysis.

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A Study of Relationship between Clothing Behavior and Needs for Exhibition and Autonomy among High School Girls (여고생의 의복행동과 과시 및 자율욕구와의 상관연구 -의복의 과시성, 유행, 교복자율화를 중심으로-)

  • Shim So Yeon;Kahang He Won
    • Journal of the Korean Society of Clothing and Textiles
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    • v.7 no.2
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    • pp.53-59
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    • 1983
  • The purpose of this study was to investigate the relationship between five aspects of clothing behavior and needs for exhibition and autonomy among high schoolgirls. Five aspects of clothing behavior were studied: fashion interest, clothing exhibition, attitudes toward the abolition of the school uniform and control of school dress. A questionnaire of 20 items prepared by Kahng, Lee, and Creekmore was used to assess fashion interest and clothing exhibition. Assessment of attitudes toward the abolition of school uniform and control of school dress was made with questions devised for this study and included several modified items from Kim's questionnaire. Preferences for fashion style were determined by line drawings representing current fashion and outdated fashion. The questionnaires were administered to 341 second year senior high school girls from three types of schools. Statistical analysis was performed using the correlation coefficient, chi-square test, ANOVA, The results were: 1) The need for exhibition was positively related to clothing exhibition and fashion interest, that is, students who had a higher need for exhibition were more interested in clothing exhibition and fashion. 2) The need for autonomy was positively related to attitudes toward the abolition of school uniform and control of school dress that is, students who had a higher need for autonomy wanted the abolition of school uniform and less control of school dress. 3) Fashion interest was positively related to preference for fashion style, that is, students who a higher fashion interest prefered fashinable styles in the selection of new clothes. 4) Scores of clothing exhibition and attitudes toward loosening of control of school dress were significantly different among three types of school. The orders from highest to lowest are following: single-sex preparatory, coeducational preparatory, vocational high school.

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Fractal Image Coding for Improve the Quality of Medical Images (의료영상의 화질개선을 위한 프랙탈 영상 부호화)

  • Park, Jaehong;Park, Cheolwoo;Yang, Wonseok
    • Journal of the Korean Society of Radiology
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    • v.8 no.1
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    • pp.19-26
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    • 2014
  • This paper suggests techniques to enhance coding time which is a problem in traditional fractal compression and to improve fidelity of reconstructed images by determining fractal coefficient through adaptive selection of block approximation formula. First, to reduce coding time, we construct a linear list of domain blocks of which characteristics is given by their luminance and variance and then we control block searching time according to the first permissible threshold value. Next, when employing three-level block partition, if a range block of minimum partition level cannot find a domain block which has a satisfying approximation error, we choose new approximation coefficients using a non-linear approximation of luminance term. This boosts the fidelity. Our experiment employing the above methods shows enhancement in the coding time more than two times over traditional coding methods and shows improvement in PSNR value by about 1-3dB at the same compression rate.

Relationships among the Self-Efficacy, Major Satisfaction and Adjustment to College Life of Nursing Students (간호대학생의 자기효능감, 전공만족도, 대학생활 적응과의 관계)

  • Jeong, Gyeongsun;Park, Euijeung
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.4
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    • pp.253-263
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    • 2019
  • Purpose : The purpose of this study was to identify the self-efficacy, major satisfaction, and degree of adjustment to college life of nursing students and the relationships among the foregoing. Methods : This study was conducted with 319 nursing students in B city from May to June 2019. The collected data were analyzed with frequency, percentage, mean and standard deviation, t-test, ANOVA, Scheffe's test, and Pearson Correlation Coefficient using the SPSS /WIN 22.0 program. Results : The self-efficacy score of nursing college students was shown to be 2.95±0.32 points, major satisfaction score was shown to be 3.83±0.55 points, and college adjustment score was shown to be 3.52±0.55 points. The degrees of adjustment to college life were significantly different according to general characteristics of nursing students as follows; grade (F=6.614, p=.000), health condition (F=13.384, p=.000), club activities (t=4.557, p=.000), happiness index (F=32.094, p=.000), part-time job (t=2.781, p=.006), and motive of major selection (F=7.300, p=.000). The adjustment to college life of nursing students showed a weak negative correlation with self-efficacy (r=-.196, p<.001) and a strong positive correlation with major satisfaction (r=.782, p<.001). Major satisfaction and self-efficacy showed a weak negative correlation (r=-.185, p<.001). Conclusion : Through the results of this study, it can be seen that repetitive studies are necessary in relation to the self-efficacy, major satisfaction, and college adjustment of nursing students, and that interest in effort for the development of programs that can improve nursing students' major satisfaction and college adjustment are necessary.

Favorability's Difference of Beard Type According to Perceiver's Characteristic

  • Kang, Daeyoung;An, Jongsuk
    • Journal of Fashion Business
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    • v.17 no.6
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    • pp.44-59
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    • 2013
  • The modern people do express their personalities by appearance and actively use the appearance as the social tools, and the attractive appearance largely does influence the human relationship. As the appearance's importance is being magnified, the attractive appearance and favourable impression is an important standard for job performance and social position, and used as the way to reach the social goal. This study does investigate the design's kind and character of the beard which belongs to the male exclusive property and compare the differences of the impression's formation according to the beard design. The empirical results confirmed that the male beard design formated the various impressions according to the designs and their mutual relationship existed. Therefore, the beard is a symbol of maleness and an expression for the social position and personal character, whereas it possesses the very important meaning as the influencing factor on the impression's change. First, the pre stimuli were finished through the pre survey for composition of questionnaire in order to evaluate the impression after selection of experimental models and beard types for measuring instruments. Second, sixty three university students were surveyed by pre stimuli and questionnaire as pre experiment, and afterwards the measuring instruments and experimental design were revised. Third, the stimuli completed (nine beard designs) were intentionally well distributed as questionnaire by sex and ages in Seoul metropolitan and her environment. and the factorial analysis and the coefficient of Cronbach's ${\alpha}$ for reliability test were completed for questionnaire's validity using SPSS/PC+ Window Ver. 12.0.

Numerical Analysis of Unsteady Heat Transfer for the Location Selection of Anti-freeze for the Fire Protection Piping with Electrical Heat Trace (소방 배관 동파방지용 열선의 위치 선정을 위한 비정상 열전달 수치해석)

  • Choi, Myoung-Young;Lee, Dong-Wook;Choi, Hyoung-Gwon
    • Fire Science and Engineering
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    • v.28 no.1
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    • pp.52-57
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    • 2014
  • In this paper, the unsteady incompressible Navier-Stokes equations coupled with energy equation were solved to find out the optimal location of electrical heat trace for anti-freeze of water inside the pipe for fire protection. Since the conduction equation of pipe was coupled with the natural convection of water, the analysis of conjugate heat transfer was conducted. A commercial code (ANSYS-FLUENT) based on SIMPLE-type algorithm was used for investigating the unsteady flows and temperature distributions in water region. From the numerical experiments, the isotherms and the vector fields in water region were obtained. Furthermore, it was found that the lowest part of the pipe cross-section was an optimal position of electrical heat trace assuming the constant thermal expansion coefficient of water since the minimum temperature of the water with the position is higher than those with the other positions.

The YIQ Model of Computed Tomography Color Image Variable Block with Fractal Image Coding (전산화단층촬영 칼라영상의 YIQ모델을 가변블록 이용한 프랙탈 영상 부호화)

  • Park, Jae-Hong;Park, Cheol-Woo
    • Journal of the Korean Society of Radiology
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    • v.10 no.4
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    • pp.263-270
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    • 2016
  • This paper suggests techniques to enhance coding time which is a problem in traditional fractal compression and to improve fidelity of reconstructed images by determining fractal coefficient through adaptive selection of block approximation formula. First, to reduce coding time, we construct a linear list of domain blocks of which characteristics is given by their luminance and variance and then we control block searching time according to the first permissible threshold value. Next, when employing three-level block partition, if a range block of minimum partition level cannot find a domain block which has a satisfying approximation error, There applied to 24-bpp color image compression and image techniques. The result did not occur a loss in the image quality of the image when using the encoding method, such as almost to the color in the YIQ image compression rate and image quality, such as RGB images and showed good.

Genetic polymorphism analysis of somatic embryo-derived plantlets of Cymbopogon flexuosus through RAPD assay

  • Bhattacharya, S.;Dey, T.;Bandopadhyay, T.K.;Ghosh, P.D.
    • Plant Biotechnology Reports
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    • v.2 no.4
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    • pp.245-252
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    • 2008
  • The genetic status of somatic embryo-derived plantlets of Cymbopogon flexuosus was examined by randomly amplified polymorphic DNA (RAPD) analysis. Auxins such as 2, 4-dichlorophenoxyacetic acid (2, 4-D) (1-4 mg/l) were used in Murashige and Skoog (MS) medium for induction of calli from rhizomatous explants of Cymbopogon flexuosus. Optimum calli were induced on MS medium supplemented with 2, 4-dichlorophenoxyacetic acid (2, 4-D) (3.5 mg/l) alone or in combination with $N^6-benzyladenine$ (2 mg/l). Somatic embryogenesis was achieved from long term calli when cultured on MS medium containing 2, 4-dichlorophenoxyacetic acid (2, 4-D) (2 mg/l) along with $N^6-benzyladenine$ (BA) (1-2 mg/l). Regeneration was achieved when freshly induced embryogenic calli were sub-cultured on MS medium supplemented with $N^6-benzyladenine$ (3 mg/l) alone. Long-term cultured embryos showed profuse minute rooting on regeneration medium supplemented with N6 -benzyladenine (3 mg/l). Microshoots were rooted in the presence of indole-butyric acid (IBA) (2 mg/l). DNA samples from the mother plant and 18 randomly selected regenerated plants from a single callus were subjected to RAPD analysis with 6 arbitrary decamer primers for the selection of putative somaclones. A total of 64 band positions were scored, out of which 19 RAPD bands were polymorphic. From genetic similarity coefficient based on RAPD band data sharing, it was found that the majority of the clones were almost identical or more than 92% similar to the mother plant, except CL2 and CL9 (66%) which showed highest degree of genetic change with CL2 and CL9 showing presence of two non-parental bands each.

Genotype $\times$ Environment Interaction for Yield in Sesame (Sesamum indicum L.)

  • Shim, Kang-Bo;Kang, Churl-Whan;Hwang, Chung-Dong;Pae, Suk-Bok;Choi, Kyung-Jin;Byun, Jae-Cheon;Park, Keum-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.53 no.3
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    • pp.297-302
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    • 2008
  • Application of genotype by environment ($G\;{\times}\;E$) interaction would be used for identifying optimum test condition of the varietal adaptation in the establishment of breeding purpose. Yield and yield components were used to perform additive main effect and multiplicative interaction (AMMI) analysis. Significant difference for $G\;{\times}\;E$ interaction were observed for all variable examined. For yield, 0.18 of total sum of squares corresponded to $G\;{\times}\;E$ interaction. Correlation analysis was carried out between genotypic scores of the first interaction principal component axis (IPCA 1) for agronomic characters. Significant correlations were observed between IPCA 1 for yield and capsule bearing stem length (CBSL), number of capsule per plant (NOC). The biplot of grain yield means for IPCA1 which accounted for 34% of the variation in total treatment sums of squares showed different reaction according to $G\;{\times}\;E$ interaction, genotypes and environments. Taegu showed relatively lower positive IPCA1 scores, and it also showed smaller coefficient variation of yield mean where it is recommendable as a optimal site for the sesame cultivar adaptation and evaluation trial. In case of variables, Yangbaek and M1 showed relatively lower IPCA1 scores, but the score direction showed opposite each other on the graph. Ansan, Miryang1, Miryang4, and Miryang6 seemed to be similar group in view of yield response against IPCA1 scores. These results will be helpful to select experimental site for sesame in Korea to minimize $G\;{\times}\;E$ interaction for the selection of promising genotype with higher stability.