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A Study on Development of Optimal Power Flow Calculation Algorithm Considering Voltage and Transient Stability (전압 및 과도안정도를 고려한 최적조류계산 알고리즘 개발에 관한 연구)

  • Kim, Yong-Ha;Lee, Buhm;Choi, Sang-Kyu;Cho, Sung-Rin;Jung, Hyun-Sung;Oh, Seok-Hyun
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.39-42
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    • 2005
  • This paper presents a optimal power flow calculation algorithm considering voltage and transient stability In this method, voltage stability margin and transient stability constraints is incorporated into a optimal power flow calculation formulation to guarantee adequate voltage and transient security levels in power system. The proposed method is applied to IEEE-24 Reliability Test System and the results shows the effectiveness of the method.

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A Study on the Star-forming Dusty Elliptical Galaxy, NGC 855

  • Park, Sung-Joon;Jeong, Woong-Seob;Seon, Kwang-Il;Kim, Minjin;Ko, Jongwan;Marcum, Pamela
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.64.1-64.1
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    • 2014
  • We study the dust and star-formation characteristics of a nearby dwarf elliptical galaxy, NGC 855. With various archival data from ultraviolet to far-infrared, we build up the spectral energy distribution (SED) that can give us constraints on stellar populations, dust characteristics, star-formation history, etc. From GALEX and SDSS data, slightly de-centered bluer central core is confirmed, where star formation might take place. This regions is coincident with seemingly dis-integrated cores detected by Spitzer IRAC data and with bright Ha feature observed at ground-based telescope. The PACS and SPIRE data by Herschel Space Observatory show the dominant dust features at the center. Lastly, we propose necessary follow-up observations with ground-based telescopes to investigate spectral properties of NGC 855.

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The effects on the color change of dental porcelain due to repeated firing (도재 소성 횟수가 색조변화에 미치는 영향)

  • Kim, Wook-Tae;Park, Chang-Keun
    • Journal of Technologic Dentistry
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    • v.30 no.1
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    • pp.33-39
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    • 2008
  • Recently natural characteristics and esthetics have been interested increasing in clinical dentistry. Thus the evaluation of the shade of dental porcelain has become an important part in dental research. Noritake Super Porcelain EX-3 Vita shade A2 (Noritake, Japan) Vintage HaLo Vita shade A2 (Shofu, Japan), Vita omega 900 Vitapan 3D-master shade 2M2 (Vita, Germany) were conducted for six times for repeated firing in a way to observe the change of color with respect to the number of firing. The repeated firing was implemented with the vacuum firing and air firing, and by using Shade Eye-EX Chroma meter (Shofu, U.S.A.), the changes in values of shade, value and chroma were compared. With the above results, the change of color was not noticed only in Vita when repeated firing was applied.

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A Study on the Non-representational Architecture in Comparing between Perspectiva artificialis and Digital Modelling Method (투시도법과 디지털 표현방식의 비교를 통한 비표상적 건축에 관한 연구)

  • Jung, In-Ha
    • Journal of architectural history
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    • v.12 no.2 s.34
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    • pp.21-39
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    • 2003
  • After a digital modelling method has been introduced into architectural design in 1990s, a radical change was taken place in generating architectural form and space. Many architects have a view that digital modelling method is the most Important invention in the visual presentation since the moment that architect Philippo Brunelleschi experimented initially the linear perspective. Therefore, in this study, comparing between perspectiva artificialis and digital modelling method, we clarify 1) the relationship of architectural design and presentation method, 2) the practical and philosophical background inherent in digital modelling method which played key role in developing non-representational architecture, 3) and the principles of non-representational architecture like diagram, folding, and trace.

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A Curriculum Enhancement Research for Practical Engineers (실천공학자 양성을 위한 교과과정 개선연구)

  • Jang, Yun-Sang;Oh, Chang-Heon;Ha, Jun-Hong
    • The Journal of Korean Institute for Practical Engineering Education
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    • v.3 no.1
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    • pp.32-39
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    • 2011
  • In this research, an improved learning system in engineering design and HRD curriculums, and an operation of experiment and practice are proposed. That is, we propose improvements for creativity, for filed orientation and for experimental and practice operation. Specifically, we suggest the possibility of common operation between engineering design and HRD curriculums based on learning experience.

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Xperanto: A Web-Based Integrated System for DNA Microarray Data Management and Analysis

  • Park, Ji Yeon;Park, Yu Rang;Park, Chan Hee;Kim, Ji Hoon;Kim, Ju Ha
    • Genomics & Informatics
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    • v.3 no.1
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    • pp.39-42
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    • 2005
  • DNA microarray is a high-throughput biomedical technology that monitors gene expression for thousands of genes in parallel. The abundance and complexity of the gene expression data have given rise to a requirement for their systematic management and analysis to support many laboratories performing microarray research. On these demands, we developed Xperanto for integrated data management and analysis using user-friendly web-based interface. Xperanto provides an integrated environment for management and analysis by linking the computational tools and rich sources of biological annotation. With the growing needs of data sharing, it is designed to be compliant to MGED (Microarray Gene Expression Data) standards for microarray data annotation and exchange. Xperanto enables a fast and efficient management of vast amounts of data, and serves as a communication channel among multiple researchers within an emerging interdisciplinary field.

Development of KEPCO Dynamic Equivalent Systems (한전계통의 동적 축약계통 구성에 관한 연구)

  • Jang, Gil-Soo;Yoon, Yong-Beum;Song, Seok-Ha;Choo, Jin-Boo
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1057-1059
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    • 1999
  • A procedure to develop dynamic equivalent systems of the KEPCO power system in the year 2010 was proposed, and 3 different equivalent systems in which the number of generators are 39, 30, and 19 were developed in this paper. The static and dynamic property of the reduced systems was verified by the comparison of time-domain simulation for the original system and the reduced systems.

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Development Of Small Signal Stablility Linear Analysis Program for Large Scale Power System. (대규모 전력계통의 미소신호 안정도 해석을 위한 선형해석 프로그램 개발)

  • Song, Sung-Geun;Nam, Ha-Kon;Shim, Kwan-Shik;Kim, Yong-Gu;Kim, Dong-Joon
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1054-1056
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    • 1999
  • It is the most important in small signal stability analysis of large scale Power systems to compute only the dominant eigenvalues selectively with numerical stability and efficiency. In this Paper evoluted linear analysis program, transformed state matrix using Inverse transformation with complex shift and then Hessenberg process and iterative scheme are used to accelerate Hessenberg process, can calculate dominant eigenvalues. In this Paper, The accuracy of this Program has been validated against 4-machines 11-bus system and New England 10-machines 39-bus system. Also applied to KEPCO system - about 791-bus 250-machines 2500-branches, got 2568 order state matrix, and calculated two dominant modes. This analysis result equaled to result of EPRI's SSSP program to use commonly, and calculating time is faster.

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Trichinosis Caused by Ingestion of Raw Soft-Shelled Turtle Meat in Korea

  • Lee, Sang-Rok;Yoo, Sang-Hoon;Kim, Hyun-Seon;Lee, Seung-Ha;Seo, Min
    • Parasites, Hosts and Diseases
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    • v.51 no.2
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    • pp.219-221
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    • 2013
  • Reptiles, unlike mammals, have been considered to be unsuitable hosts of Trichinella spp., though larvae have been detected in their muscles and human outbreaks related to their consumption have, in fact, occurred. Herein we report 2 Korean cases of trichinosis, possibly transmitted via consumption of reptile meat. Both patients suffered from myalgia, headache, and facial edema. Laboratory examinations revealed leukocytosis with eosinophilia (54% and 39%, respectively) and elevated creatinine phosphokinase. ELISA was performed under the suspicion of trichinosis, showing positivity at the 29th and 60th day post-infection. Since they had consumed raw soft-shelled turtle meat, turtle was strongly suggested to be an infection source of trichinosis in Korea next to the wild boar and badger.

Antitumor Components of Korean Basidiomycetes

  • Kim, Byong-Kak;Kim, Ji-Hyun;Kim, Ha-Won;Choi, Eung-Chil
    • Korean Journal of Pharmacognosy
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    • v.17 no.1
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    • pp.39-48
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    • 1986
  • To find antitumor components in the shake-cultured mycelia of Volvariella bombycina, the mycelia were extracted with hot water. After the extract was dialyzed and freeze-dried, a protein-polysaccharide fraction was obtained and examined for antitumor activity against the solid form of sarcoma 180 in ICR mice. It showed 60.3% inhibition ratio at a dose of 20mg/kg/day for 10 days. It was found to consist of a polysaccharide moiety and a protein moiety. After gel filtration on Sepharose 4B, Fraction B was obtained and showed the highest inhibition ratio of 71.1%. When the antitumor component was examined for immunopotentiating activity, it was found to increase the macrophage accumulation in the peritoneal cavity as well as the antibody production of the spleen cells of the mice.

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