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UY Ursae Majoris: An A-Subtype W UMa System with a Very Large Fill-Out Factor and an Extreme Mass Ratio

  • Kim, Chun-Hwey;Song, Mi-Hwa;Park, Jang-Ho;Jeong, Min-Ji;Kim, Hye-Young;Han, Cheongho
    • Journal of Astronomy and Space Sciences
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    • v.36 no.4
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    • pp.265-281
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    • 2019
  • We present new BVRI light curves of UY UMa with no O'Connell effect and a flat bottom secondary eclipse. Light curve synthesis with the Wilson-Devinney code gives a new solution, which is quite different from the previous study: UY UMa is an A-subtype over-contact binary with a small mass ratio of q = 0.21, a high inclination of 81°.4, a small temperature difference of ΔT=18°, a large fill-out factor of f = 0.61, and a third light of approximately 10% of the total systemic light. The absolute dimensions were newly determined. Seventeen new times of minimum light have been calculated from our observations. The period study indicates that the orbital period has intricately varied in a secular period increase in which two cyclical terms with periods of 12y.0 and 46y.3 are superposed. The secular period increase was interpreted to be due to a conservative mass transfer of 2.68 × 10-8 M/yr from the less massive to the more massive star. The cyclical components are discussed in terms of double-light time contributions from two additional bound stars. The statistical relations of Yang & Qian (2015) among the physical parameters of 45 deep, low mass ratio contact binaries were revisited by using the physical parameters of UY UMa and 25 Kepler contact binaries provided by Şenavci et al. (2016).

A Study on the Design of Resilient Mounting Systems for Marine Diesel Engines (선박용 디젤엔진의 탄성지지계 설계에 관한 연구)

  • 김성춘;이돈출;김의간
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.5
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    • pp.56-67
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    • 1994
  • The installation methods of diesel engines in ships would be largely classified into two groups : one is the direct mounting system fixing engine directly into double bottom of the hull, and the other is the resilient mounting system having vibration absorbers between engine and ship body such as rubber plate to prevent shocks or vibration transmission. The direct mounting system is generally used for large-sized low speed diesel engines, because the resilient mounting system has difficulties in reducing the natural frequency of engine itself under normal speed. On the contrary, the resilient mounting system is often used for medium or high speed engines for marine propulsion and generator that have light weight and high revolution speed. Recently, it is even applied to engines having relatively low speed(300-400rpm) for fishing boats. Although many researches for the resilient mounting system have been carried out, many problems in applying these results directly to marine vessels because most of these have been used for automobiles. Up to now we have had to depend on the professional foreign company in design and the supply of parts for the resilient mounting system of marinediesel engines utterly. In preseut study, the exciting forces of engines effecting to resilient mounting were examined, and patterns of vibration and evaluation procedure for force transmission from resilient mounting to the body of hull were established. Also, these results were applied to the analysis of free and forced vibration for the rubber-type resilient mounting systems of marine diesel engines. Besides, after changing the various design parameters, such as locations, angles, dynamic characteristics and the number of resilient mountings, the influences on resilient mounting system were also examined.

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Characteristics of ustilago maydis virus of SH14 killer strain isolated in Korea

  • Hwang, Seon-Hee;Jung, Cheong-Hwan;Yie, Se-Won
    • Journal of Microbiology
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    • v.33 no.2
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    • pp.154-159
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    • 1995
  • SH-14, a novel killer strain of Ustilago maydis was isolated in Korea. It has been reported in other papers that the toxin specificity and double-stranded RNA pattern of SH-14 strain were different from other laboratory strains. In this paper, we analyzed the biochemical characteristics of U. maydis SH-14 virus. Three distinctive peaks were isolated from CsCl density gradient, designated as top (T), intermediate (I) and bottom (B) components. We found that the densities of each components, 1.285, 1.408 g/cm$\^$3/, respectively, are very similar to those of other strains. As previously reported by the analysis of dsRNA in each component, the dsRNA segments are separately encapsidated. Capsid protein of SH-14 virus consists of two proteins about 70 Kd shown by SDS-PAGE analysis. Electron microscopic examination of the virus particles revealed that UmV particles are very similar in size and morphology to all isolates as well as all lab-strains. In order to test immunological cross reactivity of UmV, werstern bolt analysis was carriedout with antiserum against A8 virus. All capsid protein had positive reaction against A8 antibody which indicated that UmV are immunologically cross-reactive with all isolates from Korea. The results presented in this paper may show that UmV isolated from SH-14 strain has very similar biochemical characteristics to those of other UmV. However, the difference in the toxin specificity and the molecular weight of toxin protein from the SH-14 strain has us to conclude that U. maydis SH-14 strain is a new killer type.

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Flexural Behaviors of Precast Prestressed Rectangular and Inverted-tee Concrete Beams for Buildings

  • Yu, Sung-Yong
    • KCI Concrete Journal
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    • v.14 no.1
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    • pp.36-42
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    • 2002
  • Flexural behaviors of the two typical precast beam sections (inverted tee and rectangular) for buildings were investigated and compared. The height of web in the inverted tee beam was generally less than half of beam depth to be adapted to that of the nib in the ends of double-tee where the total building height limited considerably. The inverted-tee beams were designed for a parking live load - 500kgf/$m^2$ and a market - 1,200kgf/$m^2$ from the currently used typical shape of a domestic building site in Korea. The area and bottom dimension of rectangular beams were the same as those of inverted tee beams. These woo beams were also reinforced with a similar strength. following results were obtained from the studies above; 1) the rectangular beam is simpler in production, transportation, and erection, and more economic than the inverted tee beam in the construction test for these two beams with a same dimension and a similar strength, 2) all of the beams considered in the tests were generally failed in values close to those of the strength requirements in ACI Provisions. The ratios of test result to calculated value are averaged to 1.04. One rectangular and one inverted tee beams failed in a value only 2-3% larger than the estimated volue of the Strength Design Methool the results of the Strain Compatibility Method wire slightly more accurate than those of the Strength Design Method, 4) the maximum deflections of all of the beams under the full service loads were less than those of the allowable limit in ACI Code Provisions. The rectangular beams experienced more deflection then inverted tee in the same loading condition and failed with more deflection, and 5) the rectangular and inverted tee beams showed good performances under the condition of service and ultimate loads. However, one inverted tee beams with fm span developed an initial flexural crackings under 88% of the full service load even though they designed to satisfy the ACI tensile stress limit provisions.

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Buckling Analysis of Corrugated Board using Finite Element Method (유한요소법에 의한 Corrugated Board의 휨 발란스 해석)

  • 박종민
    • Journal of Biosystems Engineering
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    • v.28 no.2
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    • pp.127-136
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    • 2003
  • The top-to-bottom compression strength of corrugated board box is the most important mode of loading during it's no, and it depends largely on the edgewise compression strength of the corrugated board in the cross-machine direction and to a considerable extent on the flexural stiffness in both principal directions (CD; cross-machine direction, MD; machine direction) of the corrugated board. Corrugated board is a sandwich structure with an orthotropic property. The purpose of this study was to elucidate the principal design parameters for board combination of corrugated board from the viewpoint of bending strength through the finite element analysis [FEA] fur the various corrugated board. In general, the flexural stiffness [FS] in the MD was 2-3 times larger than that in the CD, and the effect of liner for the FS of corrugated board was much bigger than that of corrugating medium. The flexural stiffness index [FSI] was high when the stiffness of liner was in the order of inner, outer, and middle liner in double-wall corrugated board [DW], and the effect of the stiffness arrangement or itself reinforcement of corrugating medium on the FSI was not high. In single-wall corrugated board [SW] with DW. the variation of FSI with itself stiffness reinforcement of liner was much bigger than that with stiffness arrangement of liner. The highest FSI was at the ratio of about 2:1:2 for basis weight distribution of outer, middle, and inner liner if the stiffness of liner and total basis weight of corrugated board were equal in DW Secondarily. basis weight was in the order of inner, outer, and middle liner. However, the variation of FSI with basis weight distribution between liner and corrugating medium was much bigger than that with itself basis weight distribution ratio of liner and corrugating medium respectively in both DW and SW. md the FSI was high as more total basis weight was divided into liner. These phenomena fur board combination of corrugated board based on the FEA were well verified by experimental investigation.

Wafer-Level MEMS Capping Process using Electrodeposition of Ni Cap and Debonding with SnBi Solder Layer (Ni 캡의 전기도금 및 SnBi 솔더 Debonding을 이용한 웨이퍼 레벨 MEMS Capping 공정)

  • Choi, J.Y.;Lee, J.H.;Moon, J.T.;Oh, T.S.
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.4
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    • pp.23-28
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    • 2009
  • We investigated the wafer-level MEMS capping process for which cavity formation in Si wafer was not required. Ni caps were formed by electrodeposition on 4" Si wafer and Ni rims of the Ni caps were bonded to the Cu rims of bottom Si wafer by using epoxy. Then, top Si wafer was debonded from the Ni cap structures by using SnBi layer of low melting temperature. As-evaporated SnBi layer was composed of double layers of Bi and Sn due to the large difference in vapor pressures of Bi and Sn. With keeping the as-evaporated SnBi layer at $150^{\circ}C$ for more than 15 sec, SnBi alloy composed of eutectic phase and Bi-rich $\beta$ phase was formed by interdiffusion of Sn and Bi. Debonding between top Si wafer and Ni cap structures was accomplished by melting of the SnBi layer at $150^{\circ}C$.

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Characteristics of TOC Distribution in Lake Hapcheon (합천호의 TOC 분포 특성)

  • Seong, Jin-Uk;Kim, Hyung-Jin;Park, Jae-Chul
    • Journal of Environmental Science International
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    • v.20 no.6
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    • pp.711-719
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    • 2011
  • This study was conducted to estimate the distribution characteristics and budget of organic matter in the Lake Hapcheon. In the dry season, the concentration ranges of organic carbons were similar, but in the rainfall season, it showed about double concentrations. Changes of vertical water quality in the lake, there were no big differences with the concentration by the depth. However, it tends to be relatively high on the surface, a little low on the mid-depth and high in the lake bottom. DOC rate at TOC, it was lower than POC rate at inflow and DOC rate was higher than POC rate in the lake and discharging water. R-DOC accounted for more 80% of DOC rate in all investigated areas, therefore we judge that this R-DOC is to increase the organic carbon pollution gradually. As the result of the calculated organic carbon budget in the Lake Hapcheon, the amount of allochthonous, autochthonous and release were 3,552, 3,288, 228 tonC/year, respectively. the amount of discharge, decomposition and sedimentation were 504, 1,344, 5,520 tonC/year, respectively. According to this investigation, the changed amount of organic matter in the Lake Hapcheon recorded -300 tonC/year with the increase of 7,068 tonC/year and the decrease of 7,368 tonC/year.

A Study on Chima and Jeogori for Women appeared in Genre Pciture of Late Chosun Dynasty (조선후기 풍속화에 나타난 치마.저고리에 관한 연구)

  • 심화진
    • Journal of the Korean Society of Costume
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    • v.50 no.2
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    • pp.125-140
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    • 2000
  • The major findings of basic women wear in genre painting were ; 1. Due to the influence of Shill-Hak (practical science) philosophy, Jeogori became shorter and a tighter fit came to be the norm. 2,. The shortening of the Jeogori influenced a longer Chima with a wider span providing comfort in movement or at work. The end of the skirt was often held by one hand to the waist adding to comfort. This was called the Go-dul-chima(Lifted Chima). 3. Because the Geo-dul-chima exposed a portion of one underwear at the bottom of the dress this influenced the "irnamentation' of underpants and underskits. 4. Collars or lapels came in the form of Dang-ko, Kal, Mok-pan and Ban-Mokpan. Among there Dang-ko style collars were the most common which allows us to conclude that this was the most popular. 5. The most commonly used colors for Jeogori were white (39.8%) and jade(18.3%) . The most commonly used colors for CHima were deep blue(34.4%) and jade(20.4%) . The lower Chima used the darkercolors to give stability to the overall costume. 6. Clothing had the function of differentiating the classes. Only the Yang-ban were allowed to wear the Samhijang Jeogori and the Gob-Chima(double layered Chima) and the knotting of the Chima to the left. But the painting show that these rules were not adhered to in the strictest manner. With the bases of these types of chima and Jeogori can look at the characteristical beauty of the ordinary women during the late Cho-sun dynasty. First is the beauty which comes from mystery of those parts of body which can not be seen. A sense of subtle and sensual beauty as well as that coming from the enlargement of reduction of the upper body, narrow waist and abundant lower body parts creating an ideal silhouette of sexual charm. An expression of emotion through clothing by those who lived during those times.

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The Subjective Well-Being of People with Disabilities : A Gender Comparison to Structural Equation Model of Life Satisfaction (장애인의 주관적 삶의 질: 삶의 만족도 구조모형의 성별 비교)

  • Lee, Ji-Su
    • Korean Journal of Social Welfare
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    • v.59 no.2
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    • pp.89-114
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    • 2007
  • The purposes of this study were : (1) to find out subjective well-being structural model of people with disabilities, (2) to compare the female's subjective well-being structural model with male's. Based on previous researches related to subjective well-being of non-disabled, I applied a integrative model of bottom-up and top-down theories to subjective well-being of people with disabilities. Data were gathered from 497 persons with disabilities(253 males and 244 females) in Korea. This research shows that the female's level of life satisfaction is not different to male's. In female group, the objective life conditions(the level of education, family income, and to have jobs or not) and self esteems are important variables in subjective well-being structural equation model. In male group, on the other side, recognition about social support level is important variable. Various theoretical and practical implications for social work practice were discussed.

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Comparison on Flexural Behaviors of Architectural Precast Prestressed Rectangular and Inverted-tee Concrete Beams (건축용 프리캐스트 프리스트레스트 역티형 보와 직사각형 보의 휨거동 비교)

  • 유승룡
    • Journal of the Korea Concrete Institute
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    • v.12 no.6
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    • pp.75-82
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    • 2000
  • Flexural behaviors of two typical architectural precast beam sections ; inverted tee and rectangular - were compared and investigated. The heights of web in inverted tee beams are generally less than half of beam depth in building structures to accomodate the nib of double-tee where the total building height limited considerably. The inverted-tee beams are designed for parking live load - 500kgf/$\m^2$ and market - 1,200kgf/$\m^2$ according to the currently used typical shape in the domestic market building site in Korea. The bottom dimension and area of rectangular beams are same to those of inverted tee beams to compare the flexural behaviors of two beams. These two beams are also reinforced for similar strength. Four flexural tests are performed on two beams. Following results are obtained from the tests; 1) The rectangular beam is simpler in production, transportation, and election, and more economic than the inverted tee beam for these two beams with same dimension and similar strength. 1) The estimations of flexural strength of two beams by Strength Design Method and Strain Compatibility Method is fully complied with the result of tests. However, Strain Compatibility Method is slightly ore accurate than Strength Design Method. 2) Overall deflections of two type beam under the service loads are less than those of the allowable limit in ACI Code provision. 3) The rectangular beam is failed in large deflection (average 12.56mm large) than those of inverted tee beams. 4) The rectangular and inverted tee beams with 6m span develop initial flexural crackings under the 88% of full service loading even though they designed to satisfy the ACI tensile stress limit provisions.