• 제목/요약/키워드: research structure

검색결과 23,877건 처리시간 0.046초

Shaking Table Test and Seismic Performance Evaluation of Shanghai Tower

  • Chunyu, Tian;Congzhen, Xiao;Hong, Zhang;Jinzhe, Cao
    • 국제초고층학회논문집
    • /
    • 제1권3호
    • /
    • pp.221-228
    • /
    • 2012
  • Shanghai Tower is a super high-rise building of 632 m height with 'mega frame-core- outrigger truss' structure system. Due to the complexity and irregularity of structure, shaking table test was carried out to investigate its seismic performance. A 1/40 scaled test model was designed, built and tested on shaking table under earthquake of small, moderate and large levels. The experimental results showed that the structure can meet the requirements of Chinese codes and reach scheduled performance objectives. Elastic and plastic time-history analysis on the structure were carried out and the results were compared to experimental results. Based on the research results some suggestions were proposed to contribute favorable effect on the seismic capacity of the structure.

Newly Observed Phase Coherent Electron Transport Properties in the Mesoscopic Loop Structure of Aluminum Wire

  • Lee, Seong-Jae;Park, Kyoung-Wan;Shin, Min-Cheol;Lee, El-Hang;Kim, Ju-Jin;Lee, Hu-Jong
    • ETRI Journal
    • /
    • 제16권2호
    • /
    • pp.1-13
    • /
    • 1994
  • We have identified two new features related to the coherent transport in the mesoscopic loop structure of aluminum wire, including the autocorrelation of the conductance fluctuations beyond $B_c$ and fine structure in the low-field magnetoresistance curve in the superconducting transition regime, which, to the best of our knowledge, have not been reported in the literature. Since the electrons in Al have a phase coherence length larger than $1\;{\mu}m$ at or below T = 3K, which is comparable to the dimensions of the structure, the wave nature of the electronic transport has been clearly observed: the universal conductance fluctuations, the Aharonov-Bohm oscillations, and the Altshuler-Aronov-Spivak oscillations. Due to the transition of Al to a superconducting state at T = 1.3 K, the coherent phenomena of Cooper pairs, i.e., the Little-Parks oscillations, have also been observed.

  • PDF

Corporate Capital Structure Adjustments: Evidence from Vietnam Stock Exchange Market

  • NGUYEN, Cuong Thanh;BUI, Cuong Manh;PHAM, Tuan Dinh
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제6권3호
    • /
    • pp.41-53
    • /
    • 2019
  • Building a target capital structure is one of the most important decisions in corporate financial management. The purpose of this article is to identify the determinants of capital structure and adjustment mechanism toward the target leverage. The partial adjustment model was applied on a sample of 306 non-financial companies listed on Vietnam stock exchange market during the period of 2008-2017. By the fixed effect model estimation method, the research results have discovered the factors of growth opportunities, firm size, tangible fixed assets and firm's unique characteristics have a positive effect on the target capital structure of enterprises. Besides, profitability and dividend payment have a negative effect on the target capital structure of enterprises. Accordingly, the research results show that the average adjustment speed toward target leverage of the firms is 90.03%. Research results also demonstrate firms have higher or lower debt ratio than the target debt ratio, capital surplus or capital deficit also have an impact on the adjustment rate toward the target capital structure. The research results are consistent with the Dynamic Trade-off Theory. From this result, this article has provided policy implications for non-financial companies listed on Vietnam's stock market in building a reasonable target capital structure according to operating timeline to maximize enterprise value.

Mechanism of Piezoelectricity for Langasite Based on the Framework Crystal Structure

  • Ohsato, Hitoshi;Iwataki, Tsuyoshi;Morikoshi, Hiroki
    • Transactions on Electrical and Electronic Materials
    • /
    • 제13권2호
    • /
    • pp.51-59
    • /
    • 2012
  • Piezoelectric langasite crystals have superior properties such as high temperature performance and high quality Q and can be applied in combustion pressure sensors and surface acoustic wave (SAW) filters. Crystal growth, crystal structure and properties of langasite group are reviewed, and the mechanism of piezoelectricity of langasite is presented based on the crystal structure and deformation under high pressure. Finally, for the discovery of new piezoelectric materials, this paper presents the role of the framework, and recommends the search of framework crystal structure, because the characteristic of the mechanism exists on the framework of the crystal structure.

Dependency Structure Applied to Language Modeling for Information Retrieval

  • Lee, Chang-Ki;Lee, Gary Geun-Bae;Jang, Myung-Gil
    • ETRI Journal
    • /
    • 제28권3호
    • /
    • pp.337-346
    • /
    • 2006
  • In this paper, we propose a new language model, namely, a dependency structure language model, for information retrieval to compensate for the weaknesses of unigram and bigram language models. The dependency structure language model is based on the first-order dependency model and the dependency parse tree generated by a linguistic parser. So, long-distance dependencies can be naturally captured by the dependency structure language model. We carried out extensive experiments to verify the proposed model, where the dependency structure model gives a better performance than recently proposed language models and the Okapi BM25 method, and the dependency structure is more effective than unigram and bigram in language modeling for information retrieval.

  • PDF

발전소 수중방류구조 내 수평유공판 설치에 따른 거품발생 저감효과에 관한 실험적 연구 (Experimental Investigation on the Efficiency of Reducing Air Bubble Formation by Installing Horizontal Porous Plate in the Submerged Outlet Structure of Power Plant)

  • 오상호;오영민;강금석;김지영
    • 한국해안·해양공학회논문집
    • /
    • 제20권5호
    • /
    • pp.472-481
    • /
    • 2008
  • 이 연구에서는 보령화력발전소 방수로 수중방류구조에 대한 수리모형실험을 수행하여 수중방류구조 내 흐름 특성을 고찰하고, 수평 유공판 설치에 따른 거품저감 효과를 검토하였다. 수중방류구조 내 단면평균유속은 설계시 거품의 외해 유출 방지를 위해 고려한 목표값 1 m/s 이내에 분포하였다. 또한, 수중방류구조 내 2차 낙하 위치에 수평 유공판을 설치함에 따라 거품의 수중 최대관입깊이가 30~50% 감소함을 확인하였다. 특히, 2차 낙하 위치에 구멍의 크기가 20 cm 정도인 사각구멍형 유공판을 설치하고, 중앙부는 무공 구조로 제작하여 낙하 에너지를 소산시키게 될 경우, 가장 효과적으로 수중에 관입되는 거품 발생량을 저감시킬 수 있을 것으로 기대된다.

창업 온톨로지 구축을 위한 벤처창업 연구의 지식구조 분석 (An Analysis of the Intellectual Structure of Venture-Creation Studies to build an Entrepreneurship Ontology)

  • 심재후;최명길
    • 지식경영연구
    • /
    • 제14권4호
    • /
    • pp.75-86
    • /
    • 2013
  • The deeping interests and research toward Entrepreneurship, which is considered as an potential alternative for solving the continuing economic recession in the $21^{st}$ century, have grown. The process and methodology of the research could not be systematically arranged and the results of the research lack in efforts on the application of increasing suceess ratio in starting new business. This study adopted corpus methodology, through which we try to analyzes the knowledge structure in entrepreneurship research, derive essential concepts and the consisting domains in venture research. Based on the results of analysis, this study constructs the knowledge structure of venture research in a form of knowledge ontology. The results of the study could be a ground for entrepreneurship research and utilized as implication for a creation of construction for the entrepreneurship knowledge ontology.

  • PDF

퇴적촉진 구조물 설치에 따른 중형저서동물 군집구조 및 변동 (Community Structure and Spatial Variation of Meiobenthos Associated with an Artificial Structure)

  • 민원기;김동성;이재학
    • 한국수산과학회지
    • /
    • 제39권spc1호
    • /
    • pp.223-230
    • /
    • 2006
  • We investigated the spring and summer community structure of meiobenthos in a tidal-falt near Iwon, Korea, in 2002 and 2003. In total, 12 meiofaunal groups were found in the study area among which nematodes were the most dominant. Benthic foraminiferans, harpacticoid copepods, polychaetes, and crustacean nauplli were also dominant groups at all sites. The total density of meiobenthos at each station was be 246-2,177 ind./$10cm^2$. As the depth of sediment increased, the density of meiobenthos at each station gradually decreased. Changes in the vertical distribution of meiobenthos in the study area occurred mainly near the sediment surface (0-1 cm). Generally, between spring and summer the density of nematodes increased, and the density of other dominant meiofaunal groups (benthic harpacticoids, crustacean nauplii, benthic foraminiferans) decreased near the sediment trap the control site of sediment traps compared to that at the control site. The results of cluster and multidimensional scaling plots indicate that the meiofaunal community changed following construction of a low artificial wood groin structure.