• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.392-399
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• 2009

The paper concerns the description of the step by step development process of the new fixed blade runner called "Mixer" suitable for the uprating of the Francis turbines units installed at the older low head hydropower plants. In the paper the details of hydraulic and mechanical design are presented. Since the rotational speed of the new runner is significantly higher then the rotational speed of the original Francis one, the direct coupling of the turbine to the generator can be applied. The maximum efficiency at prescribed operational point was reached by the geometry optimization of two most important components. In the first step the optimization of the draft tube geometry was carried out. The condition for the draft tube geometry optimization was to design the new geometry of the draft tube within the original bad draft tube shape without any extensive civil works. The runner blade geometry optimization was carried out on the runner coupled with the draft tube domain. The blade geometry of the runner was optimized using automatic direct search optimization procedure. The method used for the objective function minimum search is a kind of the Nelder-Mead simplex method. The objective function concerns efficiency, required net head and cavitation features. After successful hydraulic design the modal and stress analysis was carried out on the prototype scale runner. The static pressure distribution from flow simulation was used as a load condition. The modal analysis in air and in water was carried out and the results were compared. The final runner was manufactured in model scale and it is going to be tested in hydraulic laboratory. Since the turbine with the fixed blade runner does not allow double regulation like in case of full Kaplan turbine, it can be profitably used mainly at power plants with smaller changes of operational conditions or in case with more units installed. The advantages are simple manufacturing, installation and therefore lower expenses and short delivery time for turbine uprating.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.143-155
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• 2001

Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only cross-sections of members but also configurations(howe, warren and pratt types etc.) of single truss as the number of panel and truss height. The purpose of this study is to develope automated optimum design techniques for steel truss structures considering cross-sections of members and shape of trusses simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel truss structures. In this study, the objective function is expressed as the whole member weight of trusses, and the applied constraints are as stresses, slenderness ratio, local buckling, deflection, member cross-sectional dimensions and truss height etc. The automated optimum design algorithm of this study is divided into three-level procedures. The first level on member cross-sectional optimization is performed by the sequential unconstrained minimization technique(SUMT) using dynamic programming method. And the second level about truss height optimization is applied for obtaining the optimum truss height by three-equal interval search method. The last level of optimization is applied for obtaining the optimum panel number of truss by integer programming method. The algorithm of multi-level optimization programming technique proposed in this study is more helpful for the economical design of plane trusses as well as space trusses.

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.45-52
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• 2004

To search a new porcine pheromonal odorants, this research for biostimulation and role of pheromone was augmented by means of "control system technologies" to offer a potentially useful and practical way to improve reproductive efficiency in livestock species. Therefore the 13 physicochemical parameters such as similarity indice (S), hydrophobicity (logP) and van der Waals molecule volume (MV) etc. of 54 steroid analogues, which are analogous of substrate molecules, 5$\alpha$-androst-16-en-3-one (P1) and 5$\alpha$-androst-16-en-3-ol (P2) of lipocalin as receptor of pig pheromones were calculated and discussed. The physicochemical properties of these steroid analogues were mainly followed by steric dissimilar of A and D ring in steroid nucleus. And we found that from correlation with S values and MV constants of molecules, the more MV constants are small, the more S values tend to approach 1. Based on this results, the S-values of 4-androsten-3,17-dione (P1-1) and 5 $\alpha$ -androstan-3-one (P2-1) were 1.0, respectively. The two compounds of them were chosen because they showed the same value each other at a side of hydrophobicity, molar refractivity and molecular volume. It is expected that the new two compounds will be able to substitute for P1 and P2, porcine pheromonal odorants.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.4
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• pp.99-124
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• 2015

As the improvement of digital technologies increases the use of images from various fields, the domain of image retrieval has evolved and become a growing topic of research in the Library and Information Science field. The purpose of this study is to identify the knowledge structure of the image retrieval domain by using the author co-citation analysis and author bibliographic coupling as analytical tools in order to understand the domain's past and present. The data set for this study is 245 articles with 8,031 cited articles in the field of image retrieval from 1998 to 2013, from the Web of Science citation database. According to the results of author co-citation analysis for the past of the image retrieval domain, our findings demonstrate that the intellectual structure of image retrieval in the LIS field consists of predominantly user-oriented approaches, but also includes some areas influenced by the CBIR area. More specifically, the user-oriented approach contains six specific areas which include image needs, information seeking, image needs and search behavior, image indexing and access, indexing of image collection, and web image search. On the other hand, for CBIR approaches, it contains feature-based image indexing, shape-based indexing, and IR & CBIR. The recent trends of image retrieval based on the results from author bibliographic coupling analysis show that the domain is expanding to emerging areas of medical images, multimedia, ontology- and tag-based indexing which thus reflects a new paradigm of information environment.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.160-173
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• 2013

This research aims to understand the precise character of relics based on literature search and material analysis of the jade excavated from the first buried place of King Jung-jo, and to assess the level of damage through non-destructive diagnosis. Furthermore, scientific conservation treatment was used to restore the original shape of the excavated jade. According to literature search, the excavated jade is known to be jasper, but material analysis showed that it was as a serpentine with the mineral composition of antigorite. Infrared thermography analysis to assess deterioration showed that the internal damage is the result of the interstices developed along the boundary surface of the obtained jade. For conservation treatment of the damaged area on the surface, the jade was filled with a mixture of plaster and glue, and covered with a mixture of acrylic paint and gloss medium for protection, and color was adjusted.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.1
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• pp.122-129
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• 2007

As the availability of an image information has been significantly increasing, necessity of system that can manage an image information is increasing. Accordingly, we proposed the content-based image retrieval(CBIR) method based on an efficient combination of a color feature and an image's shape and position information. As a color feature, a HSI color histogram is chosen which is known to measure spatial of colors well. Shape and position information are obtained using Hu invariant moments in the luminance of HSI model. For efficient similarity computation, the extracted features(Color histogram, Hu invariant moments) are combined and then measured precision. As a experiment result using DB that was supported by http://www.freefoto.com, the proposed image search engine has 93% precision and can apply successfully image retrieval applications.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.61-70
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• 1997

The purpose of this study was to identify the producing process for Korean nursing knowledge as applied by Foucault's discourse analytic method. By Foucault's discourse analytic method, the problem is not what is knowledge but what sort of knowledge is made up through specific level of practice. A Korean body of nursing knowledge has been discussed since 1980. At the end of 19th century, missionaries transplanted western nursing knowledge and method to Korea. Western nursing knowledge and methods have been developed continuously with both merits and demerits to Korean society. Recently our world has be come a global community via advances in transportation and correspondence. Although each person is different in skin color and shape. there is a clear line between Oriental people and Western people. Nursing science is only one in our world. but western humanistic nursing practice based on western worldview and human life has limits. It is natural that the Koreans as Oriental people have a systemic nursing science to reveal the specific experiential and concrete body of nursing knowledge rooted in the Korean worldview and human life. Nursing science is to understand human beings, to promote health. to prevent illness. to restore health. to alleviate suffering and to search for principles needed throughout all of human life. In Korea, now is the quickening period to shape a Korean body of nursing knowledge because of a shortage of nursing language in matters of intellectual recognition, and unfamiliar practical nursing field where there is no familiarity in the system of nursing research methodology. In reviewing articles from the Journal of the Nurses' Academic Society on Korean body of nursing knowledge, it was found that there are two common features. The first, human body and mind are inseperable that is one unit in this world and health is keeping a harmonious relationship between human body and mind. The second, Korean nursing practice is based on human nature and family ties. Accordingly discourse analysis has a good future prospect to produce a Korean body of nursing knowledge for analytic research on body and mind monism and family centered care based on human nature and family ties.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.123-134
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• 2004

In this research, a multilevel decomposition technique to enhance the efficiency of the configuration optimization of truss structures was proposed. On the first level, the nonlinear programming problem was formulated considering cross-sectional areas as design variables, weight, or volume as objective function and behavior under multiloading condition as design constraint. Said nonlinear programming problem was transformed into a sequential linear programming problem. which was effective in calculation through the approximation of member forces using behavior space approach. Such approach has proven to be efficient in sensitivity analysis and different form existing shape optimization studies. The modified method of feasible direction (MMFD) was used for the optimization process. On the second level, by treating only shape design variables, the optimum problem was transformed into and unconstrained optimal design problem. A unidirectional search technique was used. As numerical examples, some truss structures were applied to illustrate the applicability. and validity of the formulated algorithm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.141-154
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• 1987

The algorithm proposed utilizes the tow-levels technique. In the first level which consists of teeatment only the applied load and design stress as the random variables whose parent distribution has the normal distribution, the cross-sectional areas of the truss members such that the their probabilities of failure have the preseribed failure probabilites are optimized by transforming the nonlinear problem into SUMT, and solving it utilizing modified Newton-Raphson method. In the second level, the geometric shape of truss structure is optimized by utilizing the unidirectional search technique of Powell method which makes it possible to minimize only the objective function. The algorithm proposed is numerically tested for the several truss structures with various shapes and loading conditions. The numerical analysis shows that the rate of decreasing the weight of truss structures is dependent on the prescribed failure probability of the each member of truss structure and the covariance of the applied load and design stress.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.2
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• pp.1-15
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• 1986

The algorithm Proposed utilizes the two-levels technique. In the first level which consists of two phases, the cross-sectional area of the truss member is optimized by transforming the nonlinear problem into SUMT, and solving SUMT utilizing the modified Newton-Rahson method. In the second level, the geometric shape is optimized utilizing the unindirectional search technique of the Powell method which make it possible to minimize only the objective function. The algorithm Proposed in this study is numerically tested for several truss structures with various shapes, loading conditions and design criteria, and compared with the results of the other algorithms to examine its applicability and stability. The numerical comparisons show that the two-Levels algorithm Proposed in this study is safely applicable to any design criteria, and the convergency rate is relathely fast and stable compared with other iteration methods for the geometric optimization of truss structures.