• Title/Summary/Keyword: X형

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The Effect of Slits and Swirl Vanes on the Development of Turbulent Flow Fields in Gun-Type Gas Burner (Gun식 가스버너의 난류유동장 발달에 미치는 슬릿과 스월베인의 영향)

  • Kim, Jang-Kweon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.9
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    • pp.1299-1308
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    • 2003
  • This paper is studied to investigate the effect of slits and swirl vanes on the development of turbulent flow fields in gun-type gas burner with a cone type baffle plate because this gas burner is generally composed of eight slits and swirl vanes. All of turbulent characteristics including mean velocities were measured in the horizontal plane and cross section by using X-type hot-wire probe from hot-wire anemometer system. This experiment is carried out at flow rate 450 l/min in the test section of subsonic wind tunnel. Slits cause the fast jets, and then they have the characteristic that the flow is not adequately spread to radial direction and has long flow length and very small flow velocity distribution in the central part. On the contrary, swirl vanes does not have long enough for adequate flow length to downstream because the rotational flow diffuses remarkably to radial direction. However, the suitable arrangement between slits and swirl vanes causes effective flow width and flow length, and then it promotes fast flow mixing over the entire region including central part to increase turbulence more largely and effectively. Therefore, it is thought as a very desirable design method in gun-type gas burner to locate slits on the outside of swirl vanes.

The Comparison of the Color Perception between the Korean and the Japanese undergraduates (한일 대학생의 색지각에 대한 비교연구)

  • ;;都築和代
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.3
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    • pp.1-6
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    • 1998
  • The purpose of this study was to investigate the scope of color perception for Japan standard color. In addition to, we compared the difference in the color perception between the Korean and the Japanese undergraduates. 140 male and 119 female Japanese undergraduates were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Metre CR 300 was used for physical measurement of the color. The results were as follows, 1) Japanese students' perceived color perception was classified into four large groups: simple group includes Red, Yellow, Blue, White, Gray and Black, X(-axis)group includes Green, Red Purple, Y(-axis)group includes Green, complex group includes Blue Green, Purple, Purple Blue, Red Purple. 2) There is difference between Korean color perception and Japanese; for Yellow Red, Blue, Blue Green, Red Purple. 3) There is little difference between the values of standard color and mean percept color for Yellow while big difference for Blue. And as for as country was concerned, Korean is more accurate than Japanese in color perception.

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Characteristic Analysis of Displacement Behavior of Hollow Rollers with Cross Sectional Area Profiles (중공롤러의 절단면 형상변화에 따른 변형거동 특성해석)

  • Chung, Joon Ki;Kim, Chung Kyun
    • Journal of the Korean Institute of Gas
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    • v.19 no.4
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    • pp.55-61
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    • 2015
  • In this paper, the displacement behavior characteristic of hollow rollers with various cross sectional area profiles and circular plate for load supporting capacity increment has been presented using a finite element method. The FEM results present that the hollow roller with X-shaped or Y-shaped columns between outer tube, middle tube and inner tube reduces a maximum displacement at the middle length of hollow rollers. And the circular plate, which is inserted at the middle of the hollow roller, is very useful to reduce the maximum displacement of hollow rollers with the plate thickness of 30~40mm. This paper presents the weight vs the maximum displacement ratio in which is represented for the optimized design as a function of a hollow roller total weight. The FEM analyzed results recommend the design model 4, 5 and 6 of hollow rollers for decreasing the ratio of maximum displacement and total weight of hollow rollers.

An experimental study on the evaluation of discharge capacity for vertical plastic drain board (연직배수재의 통수능력평가를 위한 실험적 연구)

  • Kim, Joonseok;Lee, Kangil
    • Journal of the Society of Disaster Information
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    • v.13 no.4
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    • pp.483-490
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    • 2017
  • Recently, the demand for industrial and residental land are increasing with economic growth, but it is difficult to obtain the area for development with good ground condition. Various kinds of vertical drain technologies such as sand drain, sand compaction pile, packed drain, PVD are commercially available to improve the soft ground. Discharge capacity is the important factor of vertical drains. However, under field conditions, discharge capacity is changed with various reasons, such as soil condition, overburden pressure, and so on. In this paper, the experimental study was carried out to estimate the discharge capacity of four different types of PBD, PBD for double core PBD, deep type PBD, X type PBD, general type PBD. Characteristics of the discharge capacity for the surcharge load and hydraulic gradient were analysed. The double core PBD was excellent for discharge capacity in this study.

A Study on the Color Perception of University Students (대학생의 선지각에 관한 연구)

  • 안옥희;박숙현;이정옥
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.7 no.4
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    • pp.19-25
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    • 1993
  • The purpose of this study was to investigate the scope of color perception for Korean standard color. 99 male and 126 female university students were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Meter CR 300 was used for physical measurement of the color. The results were as follows, 1) Color perception was classified into four large groups: simple group includes Red, Yellow Red, Pale Red Yellow, Yellow, X( -axis)group includes Pale Yellow Red, Pale Green Yellow, Green Yellow, Purple, Pale Red Purple, Y( -axis)group includes Pale Blue Green, Blue Green, Pale Green Blue, Blue, Pale Ptuple Blue, complex group includes Pale Yellow Green, Green, Purple Blue, Pale Blue Purple, Red Purple, Pale Purple Red. 2) There is little difference between the values of standard color and mean percept color for Blue, Yellow, Pale Green Yellow, Green Yellow, Pale Yellow Green, Green, Pale Blue Green, Blue Green, Purple, while big difference for Blue, Pale Green Blue, Pale Red Purple, Pale Purple Red. 3) As for as sex was concerned, female is more accurate than male in color perception.

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A Behavioral Analysis of Curved Steel Box Bridge Associated with Diaphragm's Shape and Spacing (다이아프램 형상 및 간격에 따른 곡선 강박스거더의 거동해석)

  • Kim, Yun-Tae;Kim, Sang-Chel
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.1
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    • pp.205-215
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    • 2006
  • In this study 3-D shell FEM model was applied to analyze the behavior of curved steel box girders stiffened by diaphragms. The reliability of the analytical method has been proved by comparing with the existing results. It was also found from this analysis that main factors affecting a distortional stress are length of a girder, curvature of the girder, and spacing of diaphragms. A modelled bridge with 30m of span length and 40m of radius was analyzed to find an optimum spacing of diaphragm, and as a result of applying different spacings, 5m was found to be most appropriate to control the stress ratio regulated by specifications. In the effect of diaphragm shape, the rhamen-typed diaphragm is found to be more effective than the fully filled-up one in the range of opening ratio of 0.4 to 0.6. But, the fully filled-up diaphragm had more efficiency in terms of reducing the distortional stress than X-truss typed diaphragm.

Associated-Genes and Virulence Factors of Staphylococcus aureus Isolated from Nasal Cavity of Neonates (신생아 비강에서 분리된 황색포도구균의 병원성 인자와 관련 유전자)

  • Kim, Yung Bu;Moon, Ji Young;Park, Jae Hong
    • Clinical and Experimental Pediatrics
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    • v.46 no.1
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    • pp.24-32
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    • 2003
  • Purpose : Nosocomial infection with Staphylococcus aureus, especially methicillin resistant S. aureus, has become a serious concern in the neonatal intensive care unit. The aim of this study is to investigate the virulence factors, and the relationship between the antibiotic resistance and the associated genes of Staphylococcus aureus isolated from nasal cavity of neonates. Methods : Fifty one isolates of S. aureus were obtained from nasal swab taken in 28 neonates in the NICU and nursery of Pusan National University Hospital between February and May, 2001. They were tested in regard to antibiotic susceptibility, coagulase test and typing, plasmid DNA profile, as well as reactivity to enterotoxin A-E(sea, seb, sec, sed, see) genes and toxic shock syndrome toxin-1(tst) gene by polymerase chain reaction(PCR). Associated genes such as mecA, mecR1, mecI, and femA were also determined by PCR. The origin of MRSA strains was assessed using DNA fingerprinting by arbitrarily-primed polymerase chain reaction(AP-PCR). Results : Twenty three(45.1%) and six(11.8%) isolates were resistant to oxacillin and vancomycin respectively. Multidrug resistance to three or more of the antibiotics tested was observed in 51.0% of the isolates. Forty two isolates were coagulase positive and twenty two isolates had mecA gene. Sixteen isolates had both mecA and femA genes and had type I-III plasmids. 64.7% of isolates carried sec gene, and 80.4% carried tst gene. DNA fingerprinting by AP-PCR for 12 MRSA strains showed 10 distinct patterns, suggesting different origins. Conclusion : We confirmed that the prevalence of nasal carriage of S. aureus and the incidence of antimicrobial-resistant S. aureus, especially vancomycin resistance, is very high in neonates who were admitted in NICU and nursery. It is possible that these pathogens are responsible for serious nosocomial infections in neonates. The need for improved surveillance and continuous control of pathogens is emphasized.

The Melodic Structure of Sangnyeongsan in Gwanak-yeongsanhoesang - Focused on the Relationship between Piri Melody and Daegeum yeoneum - (관악영산회상 중 상령산의 선율 구조 - 피리 선율과 대금 연음의 관계를 중심으로 -)

  • Yim, Hyun-Taek
    • (The) Research of the performance art and culture
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    • no.39
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    • pp.701-748
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    • 2019
  • Gwanak-yeongsanhoesang, called as Samhyeon-yeongsanhoesang or Pyojeongmanbangjigok, is played by the musical instrumental organization, Samhyeonyukgak or by a large scale wind ensemble added Sogeum and Ajaeng. This study aims to analyze the structure and form of Piri melody which plays major melody of Sangnyeongsan in Gwanak-yeongsanhoesang, and to examine the relationship between Piri melody and Daegeum yeoneum grasping the structure and function of yeoneum. In Sangnyeongsan of Gwanak-yeongsanhoesang, the criterion for grouping the phrases of Piri melody is yeoneum. Especially, Daegeum yeoneum carries out the function of finishing the phrase of Piri playing the major melody by ornamenting or extending it, and presenting the motives or motive elements of the next phrase while Piri rests. The types of a, b, g, and i in the various shapes of the minimum melodic fragment of Piri are important motive elements that constitute a phrase of Piri melody. Especially, main motive a-type (仲→無) contrasts with b type (林→潢) which forms a strong tension by transposing 2 degrees upward. In addition, a-type gradually descends towards the end of music by changing to g-type (仲→林) or to i-type (太→林) which is 3 degrees below, which is related to the gradual descent cadence of Korean traditional music. A phrase of Piri melody of Sangnyeongsan in Gwanak-yeongsanhoesang consists of a combination of the types a, b, g, i, and cadence (x-type), and each phrase is structured in the repeating tension-relaxation. Looking at the structure of Piri phrases by similar types, each phrase has a logical variation structure through the methods such as omission and addition of notes, and crossing of melodies. The shape of the minimum melodic fragment of Daegeum yeoneum can be divided into a back-yeoneum of a~b types and a front-yeoneum of x1~x3. The x-types ornament Jungnyeo (仲), the cadence tone of Piri melody or are simply used as the extending back-yeoneum, and types a and b have the function of a front-yeoneum that prepares the beginning of the next phrase of Piri melody. The combination types of the minimum melodic fragment of Daegeum yeoneum appear mostly as the shape of back-yeoneum + front-yeoneum. In addition, the front-yeoneum of the type a and b appears independently without back-yeoneum, and the x3 type has a shape of the back-yeoneum without the front-yeoneum. Looking at the structure of Daegeum yeoneum by similar types, it can be seen that Daegeum yeoneum is also composed of a variation structure of omission and addition of notes like Piri melody.

Separation Behavior of Cs and Sr on the Various Zeolites (각종 제올라이트계에서의 Cs 및 Sr 분리특성)

  • Lee, Eil-Hee;Lee, Won-Kyung;Yoo, Jae-Hyung;Park, Hyun-Soo
    • Applied Chemistry for Engineering
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    • v.4 no.4
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    • pp.731-738
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    • 1993
  • This study showed the adsorption behavior of Cs and Sr into the inorganic ion-exchanger zeolites such as 4A, 13X, AW300, AW500 and natural. It was found that the best type of zeolite is AW500 for Cs and 13X for Sr in terms of ion-exchange capacity. The temperature effect was also examined for the following systems : AW500-Cs, AW300-Cs, natural zeolite-Cs, 4A-Sr and 13X-Sr. Experiments showed that the effect of temperature on the ion-exchange capacity is negligible in all cases except for the systems of 4A-Sr and natural zeolite-Cs. The enhancement in the ion-exchange capacity for 4A-Sr would be caused by the Sr ion movement and the multilayer adsorption due to the heterogeneous characteristics of ion-exchange site. The distribution coefficient was increased with pH of the solution which is in equilibrium with zeolite particles. The values of $K_d$ in the systems of AW500-Cs and 4A-Sr were found to be about $10^3cm^3/g$ and $10^3{\sim}10^4cm^3/g$ respectively.

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The Wheelchair Design for Persons with Disabilities (지체장애인용 수동식 휠체어 디자인)

  • 신학수;김성남
    • Archives of design research
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    • v.11
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    • pp.48-58
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    • 1995
  • In 1981. KOREA applied YEAR OF WORLD DISABLED DESIGNNATED BY UN as starting point to begin noticing disabled and gradually improve and understand the problems of the disabled.This study considering the income level and welfare level selected basic most widely used wheelchair as subject of study. Design Application of this study's main analysis are as follolVs 1. MAN-MACHINE INTERFACE STUDY ANALYSIS!Basic concept of wheelchair is for persons uncapable of move by sitting down. so main focus of study was considered on equipment which on chair. 2. WHEELCHAm MOVEMENT STUDY ANALYSISlThrough movement and test measurement which can be considered as basic study of Ergonomics, observe movement changes accordingly. 3. BACK(MAIN) WHEEL AND HANDRIM MOVEMENT ANALYSIS / Seat and wheel as the most important component of a wheelchair, study the relation of handrim and hand movement and test the most effective and comfortable handrim. Direction of the study was concerntrated on three areas, with results and information collected, would like to suggest design change of X type collapsible chair in areas of size of SEAT(air pocket type), HANDRIM(anti-slip hump), ARMHEST(transfer movement, rubber padding. accent), and HANDLE(adjustable, round type). The content started this study is only one small position of understanding the disabled. Also, the importance of one of many business of assisting disabled rehabilitation. (IJISABLED, REHABILITATION. APPROACH)

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