• Title/Summary/Keyword: passive construction

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Corrosion Performance of Al and Zn Coatings Deposited by Arc Thermal Spray Process in 3.5 wt.% NaCl-Contaminated Concrete Pore Solution (3.5wt.% NaCl로 오염된 콘크리트 기공 용액에서 아크 용사 공정에 의해 부착된 Al 및 Zn 코팅의 부식 성능)

  • Singh, Jitendra Kumar;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.59-60
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    • 2023
  • The corrosion of steel rebar embedded in the coastal areas is corroding once the chloride ions ingress through the pores of the concrete. Therefore, in the present study, a 100 ㎛ thick Al and Zn coating was deposited by an arc thermal spray process onto the steel. The corrosion studies of these deposited coatings were assessed in 3.5 wt.% NaCl contaminated concrete pore (CP) solution with immersion periods. The results show that the Al coating is more corrosion resistance compared to the Zn coating attributed to the formation of gibbsite (γ-Al(OH)3) whereas Zn coating exhibits Zn(OH)2 onto the coating surface as passive layer. The Zn(OH)2 is readily soluble in an alkaline solution. Alternatively, γ-Al(OH)3 on the Al coating surface is less solubility in the alkaline pH, which further provides barrier protection against corrosion.

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Inverse analysis of erection process for prismatic tensegrity structures with redundant cables

  • Pei Zhang;Huiting Xiong;Jingjing Yang;Jiayan Liu
    • Steel and Composite Structures
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    • v.49 no.2
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    • pp.125-141
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    • 2023
  • Firstly, a new kind of prismatic tensegrity structures with redundant cables is defined, the topology, geometry and forming conditions of which are introduced further. The development of its mechanical properties including self-stress states and structural stiffness with the increment of the twist angle is also investigated carefully. Combined with the topology of this kind of structures, a reasonable erection scheme is proposed, in which some temporary lifting points need to be set and two groups of vertical cables are tensioned in batches. Then, a simplified dynamic relaxation method is employed to track the erection process inversely, which aims to predict each intermediate equilibrium state during the construction, and give the key structural parameters that can effectively guide the construction. The removal of the active cables, the relaxation or tension of the passive cables are simulated by controlling their axial stiffness, so that the structural composition as well as the serial numbers of the elements always keep invariant regardless of the withdrawal of the slack cables. The whole analysis process is clear in concept, simple to implement and easy to popularize. Finally, several examples are given to verify the practicability and effectiveness of the proposed method further.

DEVELOPMENT OF NUMERICAL MODEL FOR THE VISCO-PLASTIC BEHAVIOUR OF THE JOINTED ROCK MASS REINFORCED BY ROCKBOLTS (록볼트로 보강한 절리암반의 점소성거동에 관한 수치해석 모델 개발)

  • Lee, Yeon-Gyu;Lee, Jeong-In;Jo, Tae-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 1994.09a
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    • pp.149-157
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    • 1994
  • In this study two dimensional visco-plastic finite element model capable of handling the multi-step excavation was developed for investigating the effect of excavation support sequences on the behavior of underground openings in the jointed rock mass. First, the finite element model which is capable of handling the multi-step excavation is developed and verified. And then the model is combined with visco-plastic joint model. Ubiquitous joint pattern was considered in the model and joint properties in cach set were assumed to be indentical. Passive, full-grouted rockbolts were cosidered in the numerical model. The visco-plastic deformations of joints and rockbolts were assumed to be governed by Mohr-Conlomb and von Mises yield criteria, respectively. With the ability of removing elements, the model can simulate the multi-step excavation-suppport sequences. The reliability and applicability of the model to the stability analysis for the underground excavation in pratice was checked by simulating the behavior of underground crude oil storage caverns under construction.

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MCS/IEI and Personal Exposures of VOCs in Office Worker (사무직 종사자가 일상생활에서 노출되는 VOCs 농도와 화학물질과민증 자각증상에 관한 연구)

  • Choi, Yoo-Rim;Sung, Ki-Chul;Chun, Chung-Yoon;Park, Jun-Seok
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.322-327
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    • 2006
  • In our previous research, office workers are relatively frequent in self-reported symptoms suggestive of MCS/IEI compare to construction worker who highly exposed to VOCs compounds. However in that research, the subjects were too small to say it clearly. Based on that research results, self reported symptom surveys to 110 office workers and personal exposure concentration measurement were conducted to 13 of people. VOCs exposure levels were measured within office, house and other places during a week by Passive Sampling Method. In this study, it was found that the number of office workers who met the operational criteria of MCS/IEI was 23.6% similar to 24.5% of previous result, and average of TVOC concentration was appeared high state by order of office, house, and personal exposure.

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Current Situation of Domestic Architectural Practice in order to construct Sustainable Architecture (친환경 건축물 실현을 위한 국내 설계사무소의 현황)

  • Yim, Su-Hyun
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.1
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    • pp.91-98
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    • 2011
  • This study is to concern about the effort of architectural practice to realize the sustainable architecture. It is necessary to know about the integrated design method which combines the passive design method with the active design method from the initial design phase. One case study is followed to explain the method. Integrated design starts from defining the project and goal setting, site evaluation, design concept, design optimization, documents and specifications, bidding and construction and post occupancy evaluation followed respectively. In order to construct the sustainable design, sophisticated understanding about nature and its' principle is important and adaptable application of nature and climate depending on location is followed. In conclusion, architects and specialists of sustainable design should make an effort more study.

Synthesis of an Ungrounded Inductance using Operational Amplificers (연산증폭기를 이용한 비접지 inductance의 구성방식)

  • 이태원
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.11 no.4
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    • pp.19-24
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    • 1974
  • An ungrounded inductance, necessary for construction of general type networks, is synthesized using two operational amplifiers and several passive elements. Through indefinite admittance matrix procedure. it is proved that the synthesized network is equivalent to an ungrounded pure inductance with a positive and a negative resistance in the parallel arms. A practical low-pass filter is made according to this synthesis method, and the resultant characteristic has been verified by means of IBM's simulation program ECAP (Electronic Circuit Analysis Program).

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The Pattern of the Passive Construction in Korean and its Semantics (한국어 피동문의 구조와 기능의 의미)

  • Mok, Jung-Soo;Cho, Soo-Kyung;Han, Seon-Hye;Kim, Yoon-Shin;Lee, Chung-Min
    • Annual Conference on Human and Language Technology
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    • 2003.10d
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    • pp.121-126
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    • 2003
  • 한국어 피동구문에서 출현하는 '가형 성분'에 대해 어떤 통사적 기능을 부여할 것인가에 대한 논의는 조사 자체에 대한 인식과 밀접한 관련을 맺을 뿐만 아니라 한국어 구문 분석에 있어서도 매우 중요한 위를 차지한다. 본 고에서는 논리명제적 차원에 머무는 분석보다는 언어의 발화행위 차원을 고려하여 문장의 형식을 고려할 필요성을 제기하고, 문장을 조사와 어미를 중심으로 하여 인칭과 서법 요소들을 통해서 볼 때, 문장 성분에 대한 인식이 달라질 수 있음을 '피동동사'를 중심으로 제시했다.

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VALUATION FUNCTIONALS AND STATIC NO ARBITRAGE OPTION PRICING FORMULAS

  • Jeon, In-Tae;Park, Cheol-Ung
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.14 no.4
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    • pp.249-273
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    • 2010
  • Often in practice, the implied volatility of an option is calculated to find the option price tomorrow or the prices of, nearby' options. To show that one does not need to adhere to the Black- Scholes formula in this scheme, Figlewski has provided a new pricing formula and has shown that his, alternating passive model' performs as well as the Black-Scholes formula [8]. The Figlewski model was modified by Henderson et al. so that the formula would have no static arbitrage [10]. In this paper, we show how to construct a huge class of such static no arbitrage pricing functions, making use of distortions, coherent risk measures and the pricing theory in incomplete markets by Carr et al. [4]. Through this construction, we provide a more elaborate static no arbitrage pricing formula than Black-Sholes in the above scheme. Moreover, using our pricing formula, we find a volatility curve which fits with striking accuracy the synthetic data used by Henderson et al. [10].

Lifetime Seismic Risk of Offshore Structures with a Built-in Vibration Control Device (제진장치 설치 해양구조물의 생애주기 지진위험도)

  • Kim, Dong-Hyawn
    • Journal of Ocean Engineering and Technology
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    • v.24 no.5
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    • pp.48-54
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    • 2010
  • The analysis of the seismic risk of an offshore structure with a control device is presented. First, a probability density function was developed to represent seismic hazard, and seismic fragility under artificial earthquake conditions was determined. Fragility curves for an offshore structure with both passive and active control devices were determined. Displacement criteria were set to evaluate the performance of the structure. Based on numerical analysis, the seismic risk to the structure was considerably reduced when the structure had a seismic control device. The seismic risk to the actively controlled structure was decreased by 80% compared to the uncontrolled case. Reasonable performance evaluations of offshore structure with control devices can be conducted through risk analysis.

A Study on Life Style Types and Clothing Evaluative Criteria (생활양식유형과 의복평가기준에 관한 연구)

  • Kim Mi Young;Lee Eun Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.16 no.1 s.41
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    • pp.3-21
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    • 1992
  • The main objective of this study was to find out the relationship between life style types and clothing evaluatie criteriria. Social wear was selected according to the defined time, place, and occasion's. The questionnaire was administered to 640 housewives during the fall of 1988. The research problems were as follows: 1. To segment the target according to their life styles, and to profile the characteristics of the categorized life style types. 2. To determine the differences in the clothing evaluatie criteria among the various life style types. The result were as follows: 1. Five life style types were defined. They were the Achievement oriented type, the Active- leisure type, the Material oriented type, Conservative-frugal type, and the Passive-stagnant type. 2. The differences in consumer preferences at the element level evaluative criteria including color, fiber content, fabric construction, fabric design, and classes of clothes among the five life style types were also analyzed revealing partial significance.

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