• 제목/요약/키워드: Structure Stability

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인천공항 제2터미널 에너지코어 단층 스페이스 프레임 구조물의 안정에 관한 연구 (A Study on Stability of Single-layer Space Frame Structure for Energy Core of Incheon Airport Second Terminal)

  • 정환목
    • 한국공간구조학회논문집
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    • 제15권4호
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    • pp.49-56
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    • 2015
  • The roof grid of single-layer space frame structure, for Energy Core of Incheon Airport Second Terminal, is very simple and aesthetic, but it is apt to buckle under external force because of mild curvature and complex shape. The object of this study is to estimate the stability of single-layer space frame structures for Energy Core of Incheon Airport Second Terminal with the analytical conditions of structural design. The results show that the buckling load of model(pin-pin, uniform load, rigid joint), that is, the most similar model to the analytical conditions of structural design. was $10.7kN/m^2$.

Comparison of Coverage-Dependent Adsorption Structures of Alanine and Leucine on Ge(100): Bonding Configuration and Adsorption Stability

  • 박영찬;양세나;김정원;이한길
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.215-215
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    • 2011
  • The bonding configuration and adsorption stability of alanine and leucine adsorbed on Ge(100)-2${\times}$1 surface were investigated and compared using core-level photoemission spectroscopy (CLPES) and density functional theory (DFT) calculations. The bonding configuration, stability, and adsorption energies were evaluated for two different coverage levels. In both cases, the C 1s, N 1s, and O 1s core-level spectra at a low coverage (0.30 ML) indicated that the carboxyl and amine groups participated in bonding with the Ge(100) surface in an "O-H dissociated-N dative bonded structure". At high coverage levels (0.60 ML), both this structure and an "O-H dissociation bonded structure" were present. As a result, we found that alanine adsorbs more easily (lower adsorption energy) than leucine on Ge(100) surfaces due to less steric hindrance of side chain.

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반도체 전용기용 컨트롤러의 구조 안정화 설계 (Design of a Controller for the Semiconductor Fabricator with Improved Stability)

  • 노승훈;손재율;임요한;이재열
    • 한국산업융합학회 논문집
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    • 제12권1호
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    • pp.43-50
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    • 2009
  • The manufacturing process of the semiconductor is guided by the controller, which is supposed to sense the unexpected shocks and/or vibrations to shutdown the hard disk and the whole system in order to prevent the malfunction. This feature of controller would shutdown the system due to the instability of the controller itself as well as the instability of the manufacturing system. And consequently will cause significant losses. In this study the structure of a controller has been investigated to find ways to suppress the vibrations from the structure. The frequency response test and the computer simulation has been implemented to find the structure with improved stability. The result of the study shows that the relatively simple design alterations can eliminate most of the vibrations.

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DVR 모니터의 동특성 향상을 위한 구조 개선에 관한 연구 (Design Alteration of a Security DVR Monitor Structure for the Improved Dynamic Stabilty)

  • 김건형;이원규;이태훈;노승훈;정평수
    • 한국산업융합학회 논문집
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    • 제13권2호
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    • pp.63-68
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    • 2010
  • Structural vibrations are among the biggest concerns in developing high resolution DVR(Digital Video Recorder) monitors. The vibrations in DVR monitors are mostly originated from the excitation sources such as the HDD and the cooling fan. In this study, the vibrations generated from the excitation sources were investigated in order to analyze the individual effect on the structural vibrations of the monitors and further to establish the design alteration to suppress the vibrations for the stability of the structure and for the better quality of the screen. The result shows that relatively simple design alterations can improve the stability of the structure substantially.

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스텔스 전투기 캐노피를 위한 투명 전자파 흡수구조 설계 (Design of Transparent Electromagnetic Absorbing Structure for Stealth Aircraft Canopy)

  • 홍익표
    • 한국군사과학기술학회지
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    • 제18권4호
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    • pp.369-375
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    • 2015
  • In this paper, transparent circuit analog radar absorbing structure with angular stability for stealth aircraft canopy was proposed and designed. To obtain wideband electromagnetic absorption, optical transparency and smaller thickness, we proposed the novel FSS(Frequency Selective Surface) for X-band and implemented the resistive FSS and PEC(Perfect Electric Conductor) plane using ITO(Indium Thin Oxide) coating with optical transmissivity of 90 %. Reflection loss characteristics for different incident angles of both TE(Transverse Electric) and TM(Transverse Magnetic) polarizations are presented through simulations. We then fabricated the proposed structure to verify the simulation results. The comparisons between the simulation and measured results show good agreements. The results also show that the proposed radar absorbing structure can provide better frequency stability for different incidence angles and polarizations as well as optical transparency. We can apply this proposed structure to the canopy of stealth aircraft and other stealth applications for visible transparency.

구조계획 측면에서 본 일본 목구조 교육시설의 구성특성 분석 (A Study on the Composition Features of Educational Facilities for Timber Structure in Japan with respect to Structural Planning)

  • 이주나;신은미
    • 교육시설 논문지
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    • 제25권6호
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    • pp.11-20
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    • 2018
  • In order to figure out the usability of various timber structures in the educational facility, the recent timber structure examples published in the Japanese architectural magazine, 'ShinKenchiku' over the past five years were surveyed. As the results, timber structures were presented in many cases of nursery schools and kindergartens overwhelmingly, and they also used in various school buildings, university facilities, and the roof structure of the school's gymnasium, with intention of having the differentiated design and space features. The examples show that span 6 to 10m is generally used with flexure structure system and flexure+compression structure system added the strut as compression members. In addition concerning stability, it was founded that the struts have an stability effect in the flexure+compression structure system, and flexure structure system examples using semi-rigid joints have open spaces liberally in two-way direction for about 9m span. For large spaces structures with span of 15~20m or more, the various structural system such as suspension structure, truss, flexure+compression, etc. was designed to overcome the material limitations of timbers and to make an design effect in structure system.

Nano-CMOS에서 NiSi의 Dopant 의존성 및 열 안정성 개선 (Analysis of Dopant Dependency and Improvement of Thermal stability for Nano CMOS Technology)

  • 배미숙;오순영;지희환;윤장근;황빈봉;박영호;박성형;이희덕
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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    • pp.667-670
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    • 2003
  • Ni-silicide has low thermal stabiliy. This point is obstacle to apply NiSi to devices. So In this paper, we have studied for obtain thermal stability and analysis of dopant dependency of NiSi. And then we applied Ni-silicide to devices. To improvement of thermal stability, we deposit Ni70/Co10/Ni30/TiN100 to sample. Co midlayer is enhanced thermal stability of NiSi. Co/Ni/TiN, this structure show very difference between n-poly and p-poly in sheet resistance. But Ni/Co/Ni/TiN, structure show less difference. Also junction leakage is good.

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Characteristics of Stability and Intensity of Vertical Transfer in the Western Channel of the Korea Strait

  • Chung, Jong Yul
    • 한국해양학회지
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    • 제10권2호
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    • pp.57-66
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    • 1975
  • Structure of thermocline, characteristics of stability and intensity of vertical transfer have been studied with hourly oceanographic data in each layers on Line 207 from 1968 to 1969. It is found that a typical thermocline is formed at depths of 10 to 50 meters in summer and early autumn and its core is located near depths of 25 meters. The maximum diffusion coefficient of vertical turbulent is found to be 140$\textrm{cm}^2$/sec at the surface layer(i.e., 0-10 meters), while the minimum is 5$\textrm{cm}^2$/sec at depths of 25 meters, consistent with characteristics of stability and structure of thermocline layers. Our computed diffusion coefficient and stability indicate that the mixing hardly takes place below depths of 80 meters during summer and early autumn, but for the rest of the season mixing could move up to the depth of 50 meters. It appears that the Western Channel of the Korea Strait consist of three different water masses during summer and autumn, and for the rest of the season, two kinds are present.

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길이진동을 이용하는 PZT계 세라믹 공진자의 온도안정성에 관한 연구 (A Study on Temperature Stability of PZT Piezoelectric Ceramic Resonators using Length Extensional Vibration)

  • 한성훈;임대관;이개명
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.885-887
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    • 1999
  • The piezoelectric ceramic resonator using length extensional vibration rather than contour extensional vibration in terms of the size is suitable for personal portable communication. In this paper, $Pb(Zr_{x}Ti_{l-x})O_{3}$ + r[wt%]$Cr_{2}O_{3}$ ceramics, x=0.56, 0.53, 0.50 (ie, Zr/Ti ratios = 56 /44, 53/47, 50/50) r=0, 0.3[wt %], were fabricated. Temperature stability of length extensional vibration mode of those specimens was investigated. Both crystal structure with rhombohedral phase in the case of no addition of $Cr_{2}O_{3}$ and crystal structure with morphotrophic phase boundary in case of additions of 0.3[wt %]$Cr_{2}O_{3}$ had the vest temperature stability and improved temperature stability through thermal aging.

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새로운 구조의 L-K함수를 이용한 시간 지연 선형시스템의 시간 종속 안정성 (Delay Dependent Stability of Time-delayed Linear Systems using New Structure of L-K Funciton)

  • 김진훈
    • 전기학회논문지
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    • 제62권2호
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    • pp.246-251
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    • 2013
  • In this paper, we consider the stability of linear systems without delay decomposition. A less conservative result obtained without delay decomposition is strongly required since it is a basis to get an improved result by applying simple delay decomposition. Unlike the most popular Lyapunov-Krasovski(L-K) function, we consider the cross terms between variables. Based on this new structure of L-K function, we derive a delay-dependent stability criterion in the form of linear matrix inequality(LMI). Finally, we show, by well-known two examples, that our result is less conservative than the recent results.