• 제목/요약/키워드: structural nature

검색결과 724건 처리시간 0.027초

Structural nature of chemically inequivalent borons in the nonlinear optical material β-BaB2O4 studied using 11B MAS NMR and 11B single-crystal NMR

  • Kim, Woo Young;Lim, Ae Ran
    • 한국자기공명학회논문지
    • /
    • 제17권2호
    • /
    • pp.86-91
    • /
    • 2013
  • Detailed information about the structural nature of three-coordinate borons in ${\beta}-BaB_2O_4$ is obtained through $^{11}B$ MAS NMR and $^{11}B$ single-crystal NMR. The three-coordinate $BO_3$ of the two borons B(1) and B(2) in ${\beta}-BaB_2O_4$ were distinguished. The spin-lattice relaxation time in the laboratory frame $T_1$ for B(1) and B(2) slowly decreases with increasing temperature, whereas the spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for B(1) and B(2), which differs from $T_1$, is nearly constant. The B(1) and B(2) of the two types were distinguished by $^{11}B$ MAS NMR and $^{11}B$ single-crystal NMR.

미니멀리즘이 현대패션에 미친 영향에 대한 연구 (A Study on the Influence that the Minimalism has on Modern Fashion)

  • 변지연;이순홍
    • 복식문화연구
    • /
    • 제4권3호
    • /
    • pp.427-445
    • /
    • 1996
  • According as the fashion at the latter half part of the 20th century is diversified and made into high-class gradually, it is demanding the individuality of each one. Especially, since the beginning of 1980s, fashion came to represent the restoration mood in a modern style because of the popularization of post-modernism. And with this, it came to result in the reappearance of minimalism which was one of anti-culture in 1960s. In this study, this researcher grasped the appearance background, concept and structural concept of minimalism, and tried to study the influence that he minimalism had on fashion in the flow of fashion over the first half period of the 20th century. Minimalism is the fine art trend of American characteristic which quicked by the meeting of European culture and American culture, according as the new avant-grade art of Europe moved to America after World War II Minimalism which appeared, refusing the mechanisation, industrialization and mass production of America and the falsehood of consciousness and sensitivity under existing system remained obscure by the pop art which is the commercial fine art of same period, but it came to expand the domain of work possibility of modern fine art, and it became the basis of appearance of post-modernism. Minimalism has 4 kinds of structural features which are nonside nature, repetitiousness and environment nature with 3 dimensional feature which is issue nature. Minimalism is appearing in the exfcellent and future-oriented fashon of Andre Kureju t the time of 1960 well. Then science revolution and minimalism aroused the mini-revolution, and they made the compact radio in electric home appliances and the miniskirt in fashion appear. The features of minimal fashion as Retro '60' which appeared in the decedent mood with the 21st century just before on are as follows: First, the are the pursuit of concise plastic line. Second, it is the use of high tech material Third, the miniaturization in size amy be enumerated. Minimal fashion will appear s the positive confrontation from of mankind as the optimistic viewpoint about feature in the situation hat environment was destroyed and the resources were exhausted.

  • PDF

지역분쟁의 원인 연구 (A Study on Cause of Regional Conflict)

  • 김성우
    • 융합보안논문지
    • /
    • 제19권2호
    • /
    • pp.157-162
    • /
    • 2019
  • 전쟁의 본질은 전쟁에 대한 개념뿐만 아니라 전쟁의 목적을 비롯하여 본질, 속성, 성격 등을 포함하고 있으며, 이러한 것을 이해하지 못하고서는 전쟁의 원인을 명확하게 규명할 수 없다. 인류의 역사와 더불어 시작된 전쟁은 다양한 목적을 달성하기 위해 발발하였다. 본 연구의 목적은 전쟁시 외세개입 방법과 전쟁의 근본적인 원인을 분석하고자 했다. 연구방법은 미국과 영국 등의 사회학자들의 주장과 연구 등 문서연구 방법으로 진행하였다. 연구결과, 다양한 전쟁의 목적으로 인해 전쟁에 대한 원인을 찾아내기가 단순하지는 않다. 본 연구에서는 제2차 세계대전 이후 지구상에서 발생하고 있는 지역분쟁의 원인에 대하여 주로 분석하였다. 각 지역별 소규모 분쟁과 새로운 형태의 전쟁의 원인을 규정지으려는 대부분의 논문에서 보고되는 지역적 구조적 설명들이 전적으로 믿을 만한 것은 아니지만, 국내적 요소와 외부적 요소들이 복잡하게 뒤얽혀있고 냉전이 내전을 격화시켜왔다는 주장은 명백한 사실이다. 이 연구 자료는 최근 한번도의 안보상황을 분석 및 연구하는데 기초자료로 도움을 줄 것이다.

Effect of one way reinforced concrete slab characteristics on structural response under blast loading

  • Kee, Jung Hun;Park, Jong Yil;Seong, Joo Hyun
    • Advances in concrete construction
    • /
    • 제8권4호
    • /
    • pp.277-283
    • /
    • 2019
  • In evaluating explosion-protection capacity, safety distance is broadly accepted as the distance at which detonation of a given explosive causes acceptable structural damage. Safety distance can be calculated based on structural response under blast loading and damage criteria. For the applicability of the safety distance, the minimum required stand-off distance should be given when the explosive size is assumed. However, because of the nature of structures, structural details and material characteristics differ, which requires sensitivity analysis of the safety distance. This study examines the safety-distance sensitivity from structural and material property variations. For the safety-distance calculation, a blast analysis module based on the Kingery and Bulmash formula, a structural response module based on a Single Degree of Freedom model, and damage criteria based on a support rotation angle were prepared. Sensitivity analysis was conducted for the Reinforced Concrete one-way slab with different thicknesses, reinforcement ratios, reinforcement yield strengths, and concrete compressive strengths. It was shown that slab thickness has the most significant influence on both inertial force and flexure resistance, but the compressive strength of the concrete is not relevant.

등가등분포 적재하중의 확률론적 분석 (Probabilistic Analysis of Equivalent Uniformly Distributed Live Loads)

  • 김상효;정시현;조형근
    • 전산구조공학
    • /
    • 제2권2호
    • /
    • pp.93-99
    • /
    • 1989
  • 1960년대 이후 구조공학자들이 구조해석 및 설계시의 고려대상(하중, 부재저항력 등)에 내재하는 불확실성을 구조물 안전도의 중요 영향인자로 인식하게 됨에 따라 확률이론을 도입한 구조해석 및 설계법이 급속히 발달하였고, 이 분야의 연구결과에 히입어 최근에는 기존 시방서에 이러한 설계법의 도입이 활발히 이루어지고 있다. 이러한 세계적인 경향에 맞추어, 국내에서도 확률론적 설계법을 도입하기 위해서는 설계시 고려되어야 하는 작용하중의 확률적 특성을 규명하는 연구가 선행되어야 한다. 이에 본 연구에서는 아파트에 작용하는 적재하중의 자료를 체계적으로 수집, 통계처리하여 확률적 특성을 분석하였다. 또한 이 자료를 이용하여 사용기간 동안의 극한값을 분석하여 현행 설계하중과 비교하였고, 부재별로 합리적인 설계하중안을 제시하였다.

  • PDF

A system model for reliability assessment of smart structural systems

  • Hassan, Maguid H.M.
    • Structural Engineering and Mechanics
    • /
    • 제23권5호
    • /
    • pp.455-468
    • /
    • 2006
  • Smart structural systems are defined as ones that demonstrate the ability to modify their characteristics and/or properties in order to respond favorably to unexpected severe loading conditions. The performance of such a task requires a set of additional components to be integrated within such systems. These components belong to three major categories, sensors, processors and actuators. It is wellknown that all structural systems entail some level of uncertainty, because of their extremely complex nature, lack of complete information, simplifications and modeling. Similarly, sensors, processors and actuators are expected to reflect a similar uncertain behavior. As it is imperative to be able to evaluate the impact of such components on the behavior of the system, it is as important to ensure, or at least evaluate, the reliability of such components. In this paper, a system model for reliability assessment of smart structural systems is outlined. The presented model is considered a necessary first step in the development of a reliability assessment algorithm for smart structural systems. The system model outlines the basic components of the system, in addition to, performance functions and inter-relations among individual components. A fault tree model is developed in order to aggregate the individual underlying component reliabilities into an overall system reliability measure. Identification of appropriate limit states for all underlying components are beyond the scope of this paper. However, it is the objective of this paper to set up the necessary framework for identifying such limit states. A sample model for a three-story single bay smart rigid frame, is developed in order to demonstrate the proposed framework.

Thermo-structural monitoring of RCC dam in India through instrumentation

  • Ashtankar, V.B.;Chore, H.S.
    • Structural Monitoring and Maintenance
    • /
    • 제2권2호
    • /
    • pp.95-113
    • /
    • 2015
  • The knowledge of the behavior of any roller compacted concrete (RCC) dam and its foundation is gained by studying the service action of the dam and its foundation using measurements of an external and internal nature. The information by which a continuing assurance of structural safety of the RCC dam can be gauged is of primary importance. Similarly, the fact that the information on structural and thermal behavior and the properties of concrete that may be used to give added criteria for use in the design of future RCC dams is of secondary importance. Wide spread attention is now being given to the installation of more expensive instrumentation for studying the behavior of concrete dams and reservoirs and forecasting of any adverse trends. In view of this, the paper traces installation and need of the comprehensive instrumentation scheme implemented to monitor the structural and thermal behavior of 102.4 m high RCC dam constructed near Mumbai in India. An attempt is made in the present paper to emphasize the need to undertake an instrumentation program and evaluate their performance during construction and post construction stage of RCC structures. Few typical results, regarding the thermal and structural behavior of the dam, obtained through instrumentation installed at the dam site are presented and compared with the design considerations. The fair agreement is seen in the response observed through instrumentation with that governing the design criteria.

토지이용변화에 따른 거시적 습지경관에서의 생태네트워크의 구조 및 기능적 변화 평가 (Evaluation of Structural and Functional Changes of Ecological Networks by Land Use Change in a Wetlandscape)

  • 김빈;박제량
    • Ecology and Resilient Infrastructure
    • /
    • 제7권3호
    • /
    • pp.189-198
    • /
    • 2020
  • 다양한 생태계 서비스를 제공할 수 있는 습지는 지속가능한 수질 개선 및 기후변화로 인한 영향의 완충작용 등 중요한 자연기반해법기술로 간주되어 왔다. 특히 토지이용 변화, 기후 변화 및 수문 변화에 따른 영향 저감을 위한 습지 보전의 중요성은 부각되었으나 경관규모에서의 거시적 자연기반해법기술 가능성의 검토가 미비하였다. 이에 본 연구에서는 생태 네트워크 분석을 통한 공학적 솔루션 제공 가능성을 검토하기 위해 습지경관 가상 서식종의 이동모델을 기반으로 형성된 습지 생태네트워크를 이용하여 토지이용변화에 따른 생태네트워크의 구조적, 기능적 특성 (연결성, 이동 효율성 및 집단화 계수)이 어떻게 변화하는지 분석하였다. 이를 위해 습지 밀도가 다른 네 구역의 토지이용변화를 가정하여 두 가지의 초기 면적조건에 대한 각 구역의 동시다발적 토지이용변화를 통해 생태 네트워크 특성의 변화를 분석하였다. 모든 분석결과에서 습지밀도가 높은 구역이 파괴된 경우 생태네트워크의 평균 연결성과 이동 효율성이 크게 감소하였으며, 특히 허브 (매우 높은 연결성을 지니는 노드)가 포함된 구역의 습지가 제거될 때 급격한 감소가 발생하는 것을 확인하였다. 반면, 집단화 계수는 증가하는 것으로 관찰되었다. 이를 통해 토지이용변화에 따른 생태네트워크에 대한 영향을 평가할 수 있으며 특히 향후 매개중심성 분석을 추가하여 적합한 대체습지를 조성할 수 있는 자연기반의 공학적 솔루션을 제공할 수 있을 것으로 사료된다.

인터렉티브 스토리텔링의 구조적 디자인 (Structural Design of Interactive Storytelling)

  • 이준희
    • 디자인학연구
    • /
    • 제16권4호
    • /
    • pp.375-384
    • /
    • 2003
  • Interactive storytelling is a scenario created "on the fly" with digital content through user interaction. Every time interaction occurs between the user and content, a brand new story is created. Interaction intrigues people because it provides different story from same content. Through conventional media, people shared same content and experience. However through interactive media, people encounter unique experience, over same content possibly everytime they use it. People we, by their nature, very interactive being. However, interacting with media is not an activity that people are accustomed to. Hence, designing content has been all migrating experience from existing media to an unfamiliar ground. Unique and adoptive ways of designing content for digital interactive media is being sought out from the need as the result of the evolution of integrated society and emerging information technology. People are already used to some of interactive storytelling through hyper text in CD-ROM and web sites. More complicated and different structured models were born through games that offered graphics, virtual spaces and interactivity. When drawn onto a structural graph, few attributes and similarities seem to occur. This paper will try to outline and discuss structural graphs of interactive storytelling methods and suggest some ways for better storytelling design.

  • PDF

Parametric study on equivalent damping ratio of different composite structural building systems

  • Farghaly, Ahmed Abdelraheem
    • Steel and Composite Structures
    • /
    • 제14권4호
    • /
    • pp.349-365
    • /
    • 2013
  • Structures consisting of concrete and steel parts, which are irregular in damping ratios are investigated. This investigation is a code-based seismic design of such structures. Several practical difficulties encountered, due to inherent differences in the nature of dynamic response of each part, and the different damping ratios of the two parts. These structures are irregular in damping ratios and have complex modes of vibration so that their analysis cannot be handled with the readily available commercial software. Therefore, this work aims to provide simple yet sufficiently accurate constant values of equivalent damping ratios applied to the whole structure for handling the damping irregularity of such structures. The results show that the equivalent damping ratio changes with the height of the building and the kind of the structural system, but it is constant for all accelerations values. Thus, available software SAP2000 applied for seismic analysis, design and the provisions of existing seismic codes. Finally, evaluation of different kinds of structural system used in this research to find the most energy dissipating one found by finding the best value of quality coefficient.