• Title/Summary/Keyword: circular features

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Flow and Combustion Characteristic in an Array of Multiple Pre-Mixed Methane/Air Flame Jets (메탄/공기 다중 제트 예혼합 화염에서의 유동과 연소특성)

  • Kim, Young-Su;Lee, Dae-Rae;Ha, Man-Yeong;Chang, Young-June;Jeon, Chung-Hwan;Cho, Seung-Wan;Kang, Kil-Young;Yu, Jae-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.6 s.261
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    • pp.547-557
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    • 2007
  • This study was conducted to investigate the flow and combustion characteristic of the experimental burner which was manufactured for the reflection of the oven and broil burner features. As slot shape, spacing between slots, and slot arrangement of the exit area which emits the mixing gas are different in case of oven burners and broil turners, the purpose of this study is to know the affection of the flame interaction and combustion characteristic according to the change of shape factors such as slot shape, slot arrangement, and slot-to-slot spacing. With no relation of the slot shape, as the spacing between slots became narrow, the occurrence of a lift-flame was delayed. So the combustion was possible in the leaner region, but the appearance of yellow-tip became a little fast. Slit slot port had the broadest operating range among the other slot shapes. Specially, from the side of lift-flame, as the jet that spreads downstream in the longitudinal slot was nearly circular just a few slot lengths away from the orifice, slot-to-slot spacing of the Slit port was closer than the other ports. These results could be expected through the computer numerical method and had a good agreement. As the spacing between slots increased, in case of Slit and Mix port, NOx emission rate was constant or decreased, but the NOx emission of Hole port was increased. CO emission rate of Slit and Hole port was increased as the slot-to-slot spacing was broadened.

Vortex induced vibration of circular pipes; the experiment in a water tank (원형 세장 실린더의 와 유기 진동;수조 실험 결과)

  • Kim, Yang-Hann;Park, Joo-Bae;Hong, Sup;Choi, Yoon-Rak
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.478-483
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    • 2001
  • We experimentally attempted to understand the vibration characteristics of a flexible pipe excited by vortex shedding. This has been extensively studied in the past decades (For example, see [2-9]). However, there are still areas that need more study. One of them is to study the relation between spatial characteristics of a flow induced vibrating pipe, such as its length, the distribution of wave number, and frequency responses. A non-linear mechanism between the responses of in-line and cross-flow directions is also an area of interests, if the pipe is relatively long so that structural modal density is reasonably high. In order to investigate such areas, two kinds of instrumented pipe were designed. The instrumented pipes, of which the lengths are equally 6m, are wound with rubber and silicon tape in different ways, having different vortex shedding conditions. One has uniform cross-section of diameter of 26. 7mm, and the other has equally spaced by 4 sub-sections, which are composed of different diameters of 75.9, 61.1, 45.6 and 26.7mm. Both pipes are towed in a water tank (200m ${\times}$ 16m ${\times}$ 7m) so that they experienced different vortex shedding excitations. The towing pipe experiments exhibit several valuable features. One of them is that the natural frequencies and their corresponding strain mode shapes dominate the strain response of the uniform pipe. However, for those of non-uniform pipe, the responses are more likely local and many modes participate in it.

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Stereoscopic Contents Production Workflow Based on Nonlinear Editing (비선형 편집기반의 입체영상 제작 흐름에 관한 연구)

  • Kim, Chul-Hyun;Paik, Joon-Ki
    • Journal of Broadcast Engineering
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    • v.15 no.3
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    • pp.391-406
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    • 2010
  • Digital cinema based on digital master distribution increases with stereoscopic film as the center. DCI specification V1.0 announced at 2004, it considerates stereoscopic film screening. And now, the Society of Motion Picture and Television Engineers is establishing a task force to define the standards of a stereoscopic contents viewed in the home. Today, most Hollywood commercial stereoscopic film features animation using computer graphic. However, considering film making characteristic, stereoscopic digital cinema is required shooting in real world and editing, screening. This paper presents possibility of stereoscopic examination at NLE in the stereoscopic workflow. And we will propose new stereoscopic digital cinema workflow to apply the stereoscopic examination. Based on experimental results, the 3D ready television using 120Hz has some obstacles for contents editing, but most domestic stereoscopic monitor using circular polarization is possible for successful editing.

Genomic Approaches for Understanding the Characteristics of Salmonella enterica subsp. enterica Serovar Typhimurium ST1120, Isolated from Swine Feces in Korea

  • Kim, Seongok;Kim, Eunsuk;Park, Soyeon;Hahn, Tae-Wook;Yoon, Hyunjin
    • Journal of Microbiology and Biotechnology
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    • v.27 no.11
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    • pp.1983-1993
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    • 2017
  • Salmonella enterica subsp. enterica serovar Typhimurium, one of the most common foodborne pathogens, is transmitted mainly through contaminated food derived from infected animals. In this study, S. Typhimurium ST1120, an isolate from pig feces in Korea, was subjected to whole-genome analysis to understand its genomic features associated with virulence. The genome of ST1120 was found to have a circular chromosome of 4,855,001 bp (GC content 52.2%) and a plasmid of 6,863 bp (GC content 46.0%). This chromosome was predicted to have 4,558 open reading frames (ORFs), 17 pseudogenes, 22 rRNA genes, and 86 tRNA genes. Its plasmid was predicted to have three ORFs. Comparative genome analysis revealed that ST1120 was phylogenetically close to S. Typhimurium U288, a critical isolate in piggery farms and food chains in Europe. In silico functional analysis predicted that the ST1120 genome harbored multiple genes associated with virulence and stress resistance, including Salmonella pathogenicity islands (SPIs containing SPI-1 to SPI-5, SPI-13, and SPI-14), C63PI locus, ST104 prophage locus, and various antibiotic resistance genes. In accordance with these analysis results, ST1120 showed competence in invasion and survival abilities when it was added to host cells. It also exhibited robust resistance against antibiotics in comparison with other S. Typhimurium strains. This is the first report of the complete genome sequence of S. Typhimurium isolated from swine in Korea. Comparative genome analysis between ST1120 and other Salmonella strains would provide fruitful information toward understanding Salmonella host specificity and developing control measures against S. Typhimurium infection.

Expansion of the Darcy-Weisbach Relation for Porous Flow Analysis (다공질 유동해석을 위한 Darcy-Weisbach 관계식의 확장)

  • Shin, Chang Hoon;Park, Warn Gyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.4
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    • pp.229-238
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    • 2017
  • This study started to deduce a permeability relationship that can consider the geometric features of various porous media under different flow regimes. With reference to the previous works of Kozeny and Carman, the conventional Darcy-Weisbach relation (Darcy's friction flow equation) was reviewed and expanded for porous flow analysis. Based on the capillary model, this relation was transformed to the friction equivalent permeability (FEP) definition. The validity of the FEP definition was confirmed by means of comparison with the Kozeny-Carman equation. Hereby, it was shown that the FEP definition is the generalized form of the Kozeny-Carman equation, which is confined to laminar flow through a circular capillary. In conclusion, the FEP definition as a new permeability estimation method was successfully developed by expanding the Darcy-Weisbach relation for porous flow analyses.

An Evaluation on the Cultural Sustainability of the Korean Traditional Village -The Case of Sonwon-ri Village in Youngchon- (전통마을의 문화지속성 평가 -경북 영천 선원리를 대상으로-)

  • 고석철;장병관
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.6
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    • pp.1-10
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    • 2002
  • The purpose of this study is to establish a model of cultural sustainability in the traditional village. Cultural sustainability is being advanced by promoting the viability of traditional arts and the unique regional features of traditional culture, such as folklore, traditional landscapes, buildings and other environments of outstanding historical value. These cultural resources were also created or occurred at specific geographic locations at certain points in time by different individuals. The content of this study was to develop a model using indicators for cultural sustainability, and to apply and evaluate the model. In older to evaluate the model, Sonwon-ri village in Yongchon, located in Kyungsangbuk-do, was selected as the case study area. The major findings are as follows: 1) Sonwon-ri village has maintained the vernacular landscape except at the entrance of village. Also, the village people have pride and have adapted to the natural environment. 2) Sonwon-ri village has a self-sustaining system and circular network within its environmental capacity. Sonwon-ri village has many historical sites and buildings such as important folk resources, cultural assets, traditional houses and pavilions. 3) The people how the theory of fens-shui which interprets the location of village in relationship to a crane mountain with the village situated as a crane head. These symbolic and cultural elements have an important role in establishing the boundary of the village. From the research it can be seen that Sonwon-ri village kept many cultural sustainability indicators in terms of active factors, physical factors and psychological factors. By analysing the participation of different scientific disciplines and identifying disciplinary categories, this study provides a basis for understanding how cultural sustainability is subjected to research in the field of landscape planning and design.

An Architectural Feature Study on the Restoration of Tongbanga-House at Samcheok (삼척 대이리 통방앗간 복원에 관한 건축적 특성 연구)

  • Choi, Jang-Soon;Kim, Jin-Won
    • Journal of the Korean Institute of Rural Architecture
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    • v.10 no.1
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    • pp.101-109
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    • 2008
  • It is very hard to find out Tongbanga-millhouse installed nearby a streamlet to use water with Tongbanga(a kind of water-mill) to polish cereals by pounding like a visage of its old days. It plays an important part in folkloric, architectural and educational aspects. The purpose of this study is to analyse the architectural features of Tongbanga and millhouse itself so that to find the way how to build and fabricate the materials and frame members. Therefore this study has been focused on the composition principle and fabrication method of Tongbanga-millhouse on the side of architecture. The fabrication methods of its house in accordance with regular sequences are as follows. ${\cdot}$ Firstly the decision of location of Tongbanga-millhouse and Hwak(a big mortar made of stone). ${\cdot}$ Slantly three rafter installation at an angle of $50^{\circ}$ to err on the safe side and then slantly fifteen rafter installation making a circular cone shape. ${\cdot}$ Installation of twigs to be circles from bottom to top. ${\cdot}$ Manifoldly covering of trunks peeling the barks from flax plants. ${\cdot}$ Threefoldly thatching with upside barks of oak trees. ${\cdot}$ Placing woods alike rafter on the bark thatches as a weight not to fly away by wind. ${\cdot}$ Binding woods alike rafter with vines of arrowroots to maintain the proper place. The decayed Tongbanga-millhouse by means of upper ways was restored out of all recognition.

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A Study on High Strength Concrete of Concrete Filled Steel Tube Column (CFT 기둥용 초고강도 충전콘크리트에 관한 연구)

  • Jung, Keun-Ho;Lim, Nam-Gi;Lee, Young-Do
    • Journal of the Korea Institute of Building Construction
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    • v.4 no.1
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    • pp.127-132
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    • 2004
  • CFT(Concrete Filled Steel Tube) is a structure of circular or squared of steel column filled with concrete. The steel tube holds the concrete inside and that makes this structure to perform superior features on stiffness, proof stress, transformation, fire resistance and construction itself. In this study, by over the 800kgf/$\textrm{cm}^2$ of high strength concrete for CFT column, research has been done on the basic property of matter such as fluidity, resistance on segregation, compressive strength, setting icons of the concrete filled in the steel tube under conditions of standard weather. Physical properties of concrete for CFT that Concrete with silica fume, fly ash of air entraining and high-range water reducing agent, that used to CFT column research purpose to find the most ideal composition, which is achieved by the investigation in the concrete's property of matter like ability of Slump, Slump Flow, Air content, Bleeding, and Settlement. For this study, experiments which are bused on obtained the result through physical test are practiced, with all of the experiment, specimens only for control are produced in each method of curing and analyzed to relations with core strength in mock-up test. In mock-up test, the research is studied compactability of concrete filled in tube and degree of hydration hysteresis, as a basic reference for applying to field of CFT column which is used over 800kgf/$\textrm{cm}^2$ high strength concrete.

Comparative Genome Analysis of Rathayibacter tritici NCPPB 1953 with Rathayibacter toxicus Strains Can Facilitate Studies on Mechanisms of Nematode Association and Host Infection

  • Park, Jungwook;Lee, Pyeong An;Lee, Hyun-Hee;Choi, Kihyuck;Lee, Seon-Woo;Seo, Young-Su
    • The Plant Pathology Journal
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    • v.33 no.4
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    • pp.370-381
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    • 2017
  • Rathayibacter tritici, which is a Gram positive, plant pathogenic, non-motile, and rod-shaped bacterium, causes spike blight in wheat and barley. For successful pathogenesis, R. tritici is associated with Anguina tritici, a nematode, which produces seed galls (ear cockles) in certain plant varieties and facilitates spread of infection. Despite significant efforts, little research is available on the mechanism of disease or bacteria-nematode association of this bacterium due to lack of genomic information. Here, we report the first complete genome sequence of R. tritici NCPPB 1953 with diverse features of this strain. The whole genome consists of one circular chromosome of 3,354,681 bp with a GC content of 69.48%. A total of 2,979 genes were predicted, comprising 2,866 protein coding genes and 49 RNA genes. The comparative genomic analyses between R. tritici NCPPB 1953 and R. toxicus strains identified 1,052 specific genes in R. tritici NCPPB 1953. Using the BlastKOALA database, we revealed that the flexible genome of R. tritici NCPPB 1953 is highly enriched in 'Environmental Information Processing' system and metabolic processes for diverse substrates. Furthermore, many specific genes of R. tritici NCPPB 1953 are distributed in substrate-binding proteins for extracellular signals including saccharides, lipids, phosphates, amino acids and metallic cations. These data provides clues on rapid and stable colonization of R. tritici for disease mechanism and nematode association.

A study on the development of pattern design for the modernization of the plant pattern in the Joseon dynasty (조선시대 식물문양의 현대화를 위한 패턴디자인 개발 연구)

  • Rhee, Myung Soog;Cho, Woo Hyun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.21 no.1
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    • pp.163-180
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    • 2019
  • A pattern is a symbolic mark of the psychological expression and ornamental desire of the human interior. In particular, plant patterns, from ancient times to modern times, express beauty across both the east and the west. The Joseon dynasty had a strong national will, and it was a time when the symbolism of Korea was established. Plant patterns were decorative and symbolic, filled with meaning in both the textile and craft sectors. This study looked at the frequency and figurative characteristics of the types of plant patterns in textiles, ceramics, woodworking, and metal craftsmanship of the Joseon dynasty. In addition, pattern designs were developed by extracting unit patterns to maintain the original shape, and by adding, magnifying, reducing, and superimposing flat steps and employing the four-fold sequence. The data collected was 826 examples in textiles and crafts, and 34 species of plants were analyzed as follows. In general, the flower patterns preferred soft flowers, flowers, apricot, and peony patterns, and fruit patterns emerged as decorative designs for pottery and woodwork from the 17th century, featuring pomegranates, grapes, fluorines, peaches, and walnut floss. Textiles and woodwork were arranged with many circular designs, while pottery and metal crafts were filled in many ways. Expressive types appeared to be the same as stylistic types for textiles and ceramics, and the construction types were the same in pottery and metal crafts. As such, it was found that even in the different areas of the sculpture, the same aesthetic values were reflected in the common figurative features today. Therefore, in this study, we developed a unique and competitive pattern design that accommodates the modern times and the Joseon dynasty. This development is expected to contribute not only to the development of cultural and tourism products in the future, but also to the tourism industry induced by the Korean wave.