• 제목/요약/키워드: straight-shaped

검색결과 177건 처리시간 0.023초

Ka-대역 원형 편파기와 직선구조 모드 변환기를 포함한 광대역 혼 안테나 (Wideband horn antenna including circular-polarizer and straight-type mode-converter for Ka-band)

  • 정영배
    • 전기전자학회논문지
    • /
    • 제15권4호
    • /
    • pp.299-304
    • /
    • 2011
  • 본 논문에서는 Ka-대역에서 원형편파기, 임피던스 변환기, 직선 구조 모드변환기가 결합된 원형편파 도관관안테나를 설계 및 제작하였다. 원형 편파기는 유전체를 $45^{\circ}$ 형태로 삽입하는 형태와 타원형상의 단면을 갖는 도파관구조의 두가지 모델을 설계하여 전기적인 주요특성을 비교하였다. 또한, 직선구조 모드변환기는 계단구조의 임피던스 변환구조(stepped impedance transition)를 가지며 도파관을 진행하는 TE 모드의 전력신호를 동축선의 TEM 모드로 변환시키며, 직선모드 변환기의 입력부에 위치한 Feed-through를 통하여, 안테나를 능동모듈에 직접 연결할 수 있도록 설계하였다. 제작된 안테나는 측정결과 30.085~30.885GHz의 주파수대역에서 VSWR < 1.5, Axial ratio < 1.0dB 이하의 광대역특성을 가지며, 동일한 주파수 대역 내에서 6.7 ~ 7.0 dBi의 안테나 이득을 갖는다.

현대 사회에서 갖는 훈데르트바써(Hundertwasser) 건축의 의미 (A Study on the meaning Hundertwasser's architecture in the modern Society)

  • 유연숙
    • 한국실내디자인학회논문집
    • /
    • 제8호
    • /
    • pp.3-15
    • /
    • 1996
  • Friedensreich Hundertwasser , born in Vienna 1928, is a painter, an architect and an environmentalist. His architecture is radically different from the traditional , straight -lined, functional architecture practised, for example, by the Bauhaus Masters. From the very beginning , he has tried by various means to show that radical change in thinking are necessary , possible and realized. Hundertwasser's goal in this architecture is to make and give human dwelling in harmony with nature. his architecture is characterized by avoidance of straight lines, " Window Right", irregular arrangement of windows, onion dom, a wealth of colours and such environmentally -friendly consideration as planting of roofs and realizing of "tree-tenants". hundertwasser sees houses as evolving creations which are to be shaped by their inhabitants. He hates Uniformity. The irregularity is always the guiding principle in his architecture. The Hundertwasser's architeucture express his fundamental belief that we may not simply rob nature of her resources, but that we must also return territory to nature which we habe stolen from her. Roofs, terraces and courtyards planted with vegetation and " tree-tenants" build bridges between man and nature. They influse the architecture with vitality and romanticism and are a statement of a quality rather than a standard of living. It is quite possible to value the architecture of Hundertwasser as an important inspiration, as a sort of turning point in the thoughts and actions of city planners. It's success could be healing shock for the international architectural community, which is hypnotized by technology and abused by the shortsighted interests of ren.tability . Under this pressure, today's architects trend to reduce people to a mere part of the " Dwelling machine", without acknowledging that in the long run such machines eat away at people's souls.uch machines eat away at people's souls.

  • PDF

프랭크 로이드 라이트의 유소니언 주택 평면의 공간 개념 분석에 관한 연구 (A Study on the Analysis the Space Concept of Usonian House Floor Plans of Frank Lloyd Wright)

  • 황용운
    • 한국실내디자인학회논문집
    • /
    • 제23권2호
    • /
    • pp.12-20
    • /
    • 2014
  • The purpose of this study is to analyze the general patterns of the floor plans and space of Usonian house which designed by Frank Lloyd Wright. this thesis can be summarized as follows : 1) F.L.Wright's houses mostly used simple geometric shapes as the basis for most of his architectural designs. In his early works, his typical floor plans were square or rectangular shapes, which gradually were transformed into various kinds of shape to make the adjustment of location of the site and shape. 2) The general patterns of floor plans of his U-houses were L-shaped or straight shaped using a $4{\times}4$ grid system. Most of U-houses consisted of 3 space: living room, workspace(Kitchen) & dining, and bedroom. Among them, a workspace worked as core role in each house. 3) Even though solid wall is the opposite concept of the transparent glass but most U-houses were designed to have solid walls on one side to provide a gallery space(to secure habitability of resident) and transparent glass walls used on the other side to connect between interior space and natural space of exterior. 4) The cantilever have not been used before Usonian house but F.L.Wright used it which take charge of functions as transfer space between inside space and outside space. 5) F.L.Wright saw the nature as a truth, so he thought the interior space would be natural and all houses must be able to adjust to the natural environment.

Comparison of the Genetic Relationships and Osteological Aspects in Six Branchiostegid Fish Species (Perciformes)

  • Ryu, Jung-Hwa;Kim, Jin-Koo;Park, Jung-Youn
    • Animal cells and systems
    • /
    • 제13권3호
    • /
    • pp.323-329
    • /
    • 2009
  • We analyzed partial sequences of cytochrome b (cyt-b), a mitochondrial DNA (mtDNA) gene, to determine the genetic relationships between six horsehead fish species: Branchiostegus japonicus, Branchiostegus albus, Branchiostegus auratus, Branchiostegus argentatus, Branchiostegus wardi, and an unidentified Branchiostegus species. The specimens were collected in Korea, China, Japan, and Vietnam. We compared their molecular phylogenetic relationships inferred from mtDNA cyt-b sequences with an osteological analysis. The unidentified species, B. sp., was similar to B. albus in terms of the lack of triangular silver-white dot at the posterior region of eyes (vs. large one present in B. japonicus), but was also similar to B. japonicus in terms of the presence of a straight-shaped first hemal spine (vs. a curve-shaped hemal spine in B. albus). Analysis of the mtDNA cyt-b sequences indicated that the smallest estimated sequence divergence was between the B. japonicus and B. sp. (0.70-0.94%), whereas the largest difference was between B. auratus and B. argentatus (23.06-23.36%). Both the maximum parsimony and maximum likelihood trees showed that the B. sp. was closely clustered with B. japonicus, and that B. auratus was most distant from the other species. When comparing the osteological characters, UPGMA tree showed that the B. japonicus and B. sp. were the most closely clustered species, and B. auratus was the most distantly clustered fish relative to the other species. The shape of the nasal, otolith and first hemal spine was informative for distinguishing B. auratus from the other species. These osteological differences were consistent with the differences in mtDNA.

회향종자의 발아촉진에 관여하는 요인 (Factors Involved in Promoting Seed Germination of Foeniculum vulgare)

  • 이은일;최주호;이종기;김석현
    • 한국작물학회지
    • /
    • 제42권4호
    • /
    • pp.435-445
    • /
    • 1997
  • 최근 생활수준의 향상과 보건에 대한 관심의 증가로 약용식물 재배와 한약에 대한 연구가 증가되고 있다. 그러나 대량번식을 위한 종자번식에 있어서 많은 문제점을 안고 있다. 특히 산형과 약용식물에 있어서 시호(Bupleurum falcatum)나 회향(Foeniculum vulgare)은 발아율을 증가시키는데 있어서 만족할만한 발아율을 얻지 못하고 있기 때문에 본 연구를 수행하였다. 회향은 60%의 발아율은 나타내며 15, 20, 25, 15~2$0^{\circ}C$의 발아온도 처리간의 별다른 차이가 없었다. 호르몬 처리나 물리화학적 처리에서도 발아를 증진시킬 수 없었다. 이러한 발아불량의 원인은 시호에서와 같이 결국 무배종자가 많은 것으로 추정된다. 해부현미경과 주사현미경으로 종자의 배와 주공을 관찰한 결과 배가 있는 것과 없는 것의 비율이 1/1이며 주공자체내에는 문제가 없었다. Y자형과 일자(一字)형의 배를 가진 종자가 동시에 관찰되었다

  • PDF

국내 아파트 단지 외부공간의 디자인 특성 분석 - 최근 10년간 굿 디자인(Good Design) 수상 아파트 단지를 대상으로 - (A Study on the Design Characteristic of Outdoor Spaces in the Apartment Complex - Focused on the Good Design Awarded Apartment Complex in the Past Decade -)

  • 정현원;오정아
    • 한국실내디자인학회논문집
    • /
    • 제24권1호
    • /
    • pp.160-168
    • /
    • 2015
  • The subject of this research is to analyze the design characteristics of outdoor spaces in Good Design awarded apartment complexes in the past decade. The results are as follows. First, the overall outdoor space design theme, one of the conceptual elements, is focused on both 'nature' and 'story of various subject' that are similar to each other. Second, the case study object with the visual openness, which is secured between apartment blocks, is shown frequently in case box-shaped apartment blocks are arranged in a row. However, in case of Y-shaped block arrangement, the visual openness secured within an apartment complex is considered more important. Third, according to the result of circulation/ inner path element, the most frequently appeared inner path form is a grid pattern with straight path emphasis. While apartment complexes with the parking lot on the ground are only 3 out of 18 cases, it with circulation path for vehicle on the ground level are over 61%. Fourthly, the design characteristic of social space of physical outdoor design appears to be 'central link facility type'. In this case, the central community facilities are more likely to be combined with various functions, such as green, water, and social connection. Fifthly, in case of natural space, most of the apartment cases are shown over 45% green area ratio with wide green and water space provision. Especially, the differentiation is to provide the space where can stimulate a resident's participation.

고압터빈 노즐 압력면에서의 확장 형상 막냉각 홀 배열 최적설계 (Design Optimization of Fan-shaped Film Cooling Hole Array on Pressure Side Surface of High Pressure Turbine Nozzle)

  • 이상아;이동호;강영석;김진욱;서도영;이관중
    • 한국유체기계학회 논문집
    • /
    • 제17권6호
    • /
    • pp.52-58
    • /
    • 2014
  • In the present work, design optimization of film-cooling hole array on the pressure side of high pressure turbine nozzle was conducted. There are four rows of fan-shaped film cooling holes on the nozzle pressure side surface and each row has a straight array of holes in the spanwise direction for baseline model. For design optimization, hole distributions in streamwise and spanwise directions for three rows of holes except first row are parameterized as a 2nd-order shape function. Three-dimensional compressible RANS equations are used for flow and thermal analysis around the nozzle surface and optimization technique using Design of Experiment, Kriging surrogate model and Genetic Algorithm is used. The results shows that averaged adiabatic wall temperature at the whole nozzle surface decreases about 2.7% and averaged film cooling effectiveness at the pressure side of nozzle increased about 8.2%.

조선전기 출토 여성복식의 유형과 특징에 관한 연구 (A Study on the Types and Characteristics of Women's Costume Excavated in the Early Joseon Dynasty)

  • 정주란;김용문
    • 복식
    • /
    • 제67권1호
    • /
    • pp.147-168
    • /
    • 2017
  • This study examines the types and characteristics of women's garments excavated in the early Joseon Dynasty before 1592. The study sorts out headgear, jacket, skirt and trousers, and coats from the historical texts in the early Joseon Dynasty and excavated women's wears in the fifteenth and sixteenth centuries, and analyzes their textiles and patterns. The Joseon women's garments convey several features. They are wide across the chest and square shaped collar with virtually straight sleeves. While their breast-ties are extremely little for the size of clothes, they do not have any inner-tie. They have broad and short dongjeongs which seem to be hard to be adjusted. There are a variety of headgear. Jang-Jeogori slit down in both sides. The Jeogori after the seventeenth century transformed a more practical form of a fitting dress to an individual body in comparison with the sixteenth jeogori. It is identified that the fabrics in the early Joseon period were woven more diversely and colorfully than the late Joseon period. Most of the excavated fabrics in the sixteenth century were in silk. Materials for adornments before 1592 were not much diverse and their designs mostly contained patterns of lotus flowers, patterns of cloud and treasures with oblique lines. The colors are mainly brown, navy and green. The Joseon women's clothes were comprised of skirts with folded hem, coat with round collars, wide leg pants, Jangot, long-sleeved coat with folding collars, and quadrangular pieces of cloth in various sizes, or mu and so forth. Joseon women's clothes, like men's wears, partake of active functions in their headgears, wide leg pants, styles in short front and long back, and coat with round collars.

실내시험에 의한 새로운 격자지보재의 하중지지력 평가 (Load Bearing Capacity Evaluation of New Lattice Girder by Laboratory Test)

  • 최영남;장연수;김동규;배규진
    • 토지주택연구
    • /
    • 제2권2호
    • /
    • pp.183-188
    • /
    • 2011
  • 최근 건설되는 터널의 심도가 깊어져 난공사 구간이 증가되며, 초장대 터널의 증가로 터널 기술 개발이 필요해지고 있다. 터널의 기술개발의 하나로 터널 강지보재로 사용되는 높이 95mm 격자지보재에 사용되는 스파이더를 최적화하여 U자형과 보강재스파이더를 개발하였다. 개발된 격자지보재의 하중지지력을 평가하기 위하여 국내에서 사용되는 4절점 휨강도 실험을 실시하였으며 실내 실험을 위해 기존 격자지보재와 개발된 격자지보재의 시편을 직선으로 제작하여 실시하였다. 실험 결과 새로운 격자지보재는 기존의 격자지보재에 비하여 하중지지력이 높게 나타났다. 지지력 평가에 의한 시편의 응력-변형 거동을 분석한 결과 기존 격자지보재는 탄소성 거동이 나타났고, 새 격자지보재는 응력연화의 거동이 나타났다. 새 격자지보재는 하중이 가해지는 지점의 위치에 따라 지지력 거동이 달라짐을 알 수 있었다.

FLUID-STRUCTURE INTERACTION IN A U-TUBE WITH SURFACE ROUGHNESS AND PRESSURE DROP

  • Gim, Gyun-Ho;Chang, Se-Myoung;Lee, Sinyoung;Jang, Gangwon
    • Nuclear Engineering and Technology
    • /
    • 제46권5호
    • /
    • pp.633-640
    • /
    • 2014
  • In this research, the surface roughness affecting the pressure drop in a pipe used as the steam generator of a PWR was studied. Based on the CFD (Computational Fluid Dynamics) technique using a commercial code named ANSYS-FLUENT, a straight pipe was modeled to obtain the Darcy frictional coefficient, changed with a range of various surface roughness ratios as well as Reynolds numbers. The result is validated by the comparison with a Moody chart to set the appropriate size of grids at the wall for the correct consideration of surface roughness. The pressure drop in a full-scale U-shaped pipe is measured with the same code, correlated with the surface roughness ratio. In the next stage, we studied a reduced scale model of a U-shaped heat pipe with experiment and analysis of the investigation into fluid-structure interaction (FSI). The material of the pipe was cut from the real heat pipe of a material named Inconel 690 alloy, now used in steam generators. The accelerations at the fixed stations on the outer surface of the pipe model are measured in the series of time history, and Fourier transformed to the frequency domain. The natural frequency of three leading modes were traced from the FFT data, and compared with the result of a numerical analysis for unsteady, incompressible flow. The corresponding mode shapes and maximum displacement are obtained numerically from the FSI simulation with the coupling of the commercial codes, ANSYS-FLUENT and TRANSIENT_STRUCTURAL. The primary frequencies for the model system consist of three parts: structural vibration, BPF(blade pass frequency) of pump, and fluid-structure interaction.