• 제목/요약/키워드: Material Uncertainty

검색결과 336건 처리시간 0.026초

Probabilistic behavior of semi-active isolated buildings under pulse-like earthquakes

  • Oncu-Davas, Seda;Alhan, Cenk
    • Smart Structures and Systems
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    • 제23권3호
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    • pp.227-242
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    • 2019
  • Seismic isolation systems employ structural control that protect both buildings and vibration-sensitive contents from destructive effects of earthquakes. Structural control is divided into three main groups: passive, active, and semi-active. Among them, semi-active isolation systems, which can reduce floor displacements and accelerations concurrently, has gained importance in recent years since they don't require large power or pose stability problems like active ones. However, their seismic performance may vary depending on the variations that may be observed in the mechanical properties of semi-active devices and/or seismic isolators. Uncertainties relating to isolators can arise from variations in geometry, boundary conditions, material behavior, or temperature, or aging whereas those relating to semi-active control devices can be due to thermal changes, inefficiencies in calibrations, manufacturing errors, etc. For a more realistic evaluation of the seismic behavior of semi-active isolated buildings, such uncertainties must be taken into account. Here, the probabilistic behavior of semi-active isolated buildings under historical pulse-like near-fault earthquakes is evaluated in terms of their performance in preserving structural integrity and protecting vibration-sensitive contents considering aforementioned uncertainties via Monte-Carlo simulations of 3-story and 9-story semi-active isolated benchmark buildings. The results are presented in the form of fragility curves and probability of failure profiles.

Reliability analysis of laminated composite shells by response surface method based on HSDT

  • Thakur, Sandipan N.;Chakraborty, Subrata;Ray, Chaitali
    • Structural Engineering and Mechanics
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    • 제72권2호
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    • pp.203-216
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    • 2019
  • Reliability analysis of composite structures considering random variation of involved parameters is quite important as composite materials revealed large statistical variations in their mechanical properties. The reliability analysis of such structures by the first order reliability method (FORM) and Monte Carlo Simulation (MCS) based approach involves repetitive evaluations of performance function. The response surface method (RSM) based metamodeling technique has emerged as an effective solution to such problems. In the application of metamodeling for uncertainty quantification and reliability analysis of composite structures; the finite element model is usually formulated by either classical laminate theory or first order shear deformation theory. But such theories show significant error in calculating the structural responses of composite structures. The present study attempted to apply the RSM based MCS for reliability analysis of composite shell structures where the surrogate model is constructed using higher order shear deformation theory (HSDT) of composite structures considering the uncertainties in the material properties, load, ply thickness and radius of curvature of the shell structure. The sensitivity of responses of the shell is also obtained by RSM and finite element method based direct approach to elucidate the advantages of RSM for response sensitivity analysis. The reliability results obtained by the proposed RSM based MCS and FORM are compared with the accurate reliability analysis results obtained by the direct MCS by considering two numerical examples.

"호모 이코노미쿠스"로서의 로빈슨 크루소 재고 (Reconsidering Robinson Crusoe as Homo Economicus)

  • 이석구
    • 영어영문학
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    • 제64권4호
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    • pp.629-649
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    • 2018
  • To date, one of the prevailing criticisms of Daniel Defoe's Robinson Crusoe has seen the adventure novel as a celebration of the rise of mercantile capitalism and the beginnings of colonialism. From this point of view, the Englishman has often been interpreted as an early embodiment of the concept of the sovereign economic subject. Prominent social critics who took up this interpretation have included Karl Marx, Max Weber, and Jean-Jacques Rousseau. Within literary studies proper, the work of Ian Watt offered perhaps the earliest version of this point of view of the novel. Influenced by both Weber and Rousseau, Ian Watt argued that Defoe's wandering protagonist embodies the rise of economic individualism. More recent criticism has tended to challenge this dominant interpretation by laying greater stress on such countervailing factors as Crusoe's mental uncertainty and inner conflict. Drawing inspiration from Fredric Jameson's diagnosis of the ills of late capitalism, this paper analyzes the ways in which Defoe's hero, rather than championing modern rationality, can in fact be seen as suffering from many forms of emotional psychosis. Robinson Crusoe can, after all, be better viewed as a contradictory multi-layered text that, despite its outward valorization of economic individualism, portrays its hero as a victim of negative capitalistic forces, a hero driven by his desire to possess but haunted by a fear of loss, a hero who flaunts inflated feelings of self-worth even as he reveals deflated notions of material insecurity and mental persecution.

FTA 원산지누적 분쟁사례와 개선방안 연구: 한-아세안 FTA를 중심으로 (A Study on the Dispute Cases and Improvement Related to the FTA Cumulation: A Focus on the KOREA-ASEAN FTA)

  • 고재길
    • 한국중재학회지:중재연구
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    • 제30권4호
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    • pp.95-119
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    • 2020
  • Securing a stable supply chain is becoming a significant concern among countries as the global uncertainty rises with the expansion of global protectionism and the result of what the COVID-19 pandemic has brought around the world. This study has investigated dispute cases between customs authority and trade corporations based on the KOREA-ASEAN FTA and suggested the following implications and improvements: Firstly, the extent (varieties) of the proof document on cumulation and its form should be stipulated and provided through consultation between customs from each contracting party. Secondly, it ought to be prescribed as an obligation so that producers located in the third country can cooperate in providing documents for certification of origin. The duty to provide such documentary evidence should also be specified when making EX-IM contracts. Lastly, origin verification provisions regarding cases to which cumulation is applied have to be complemented so that the verification period's extension can be applied and approved. One can expect that the abovementioned responses on cumulation will enhance the availability of KOREA-ASEAN FTA.

Cybercrime in the Economic Space: Psychological Motivation and Semantic-Terminological Specifics

  • Matveev, Vitaliy;Eduardivna, Nykytchenko Olena;Stefanova, Nataliia;Khrypko, Svitlana;Ishchuk, Alla;Ishchuk, Olena;Bondar, Tetiana
    • International Journal of Computer Science & Network Security
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    • 제21권11호
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    • pp.135-142
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    • 2021
  • The article reveals the essence of cybercrime, approaches to understanding this concept, classification of cybercrime, and other illegal acts in this area. The concept of cybercrime has multi-discourse nature and a certain legal uncertainty. Cybercrimes, their forms and types are analyzed in the economic context. The research vocabulary of the economic industry is defined. The scope and content of concepts denoted by the terms of the sphere covered by cybercrime are studied, and its types and forms are analyzed. The article studies problems, achievements, and prospects of resisting and combating cybercrime during the development of the civil information society and Ukraine's entry into the global information space. The study focuses on the economic motivation of most cybercrimes since some material benefit from the fact of cyber offenses is assumed directly or indirectly.

Seismic capacity evaluation of fire-damaged cabinet facility in a nuclear power plant

  • Nahar, Tahmina Tasnim;Rahman, Md Motiur;Kim, Dookie
    • Nuclear Engineering and Technology
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    • 제53권4호
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    • pp.1331-1344
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    • 2021
  • This study is to evaluate the seismic capacity of the fire-damaged cabinet facility in a nuclear power plant (NPP). A prototype of an electrical cabinet is modeled using OpenSees for the numerical simulation. To capture the nonlinear behavior of the cabinet, the constitutive law of the material model under the fire environment is considered. The experimental record from the impact hammer test is extracted trough the frequency-domain decomposition (FDD) method, which is used to verify the effectiveness of the numerical model through modal assurance criteria (MAC). Assuming different temperatures, the nonlinear time history analysis is conducted using a set of fifty earthquakes and the seismic outputs are investigated by the fragility analysis. To get a threshold of intensity measure, the Monte Carlo Simulation (MCS) is adopted for uncertainty reduction purposes. Finally, a capacity estimation model has been proposed through the investigation, which will be helpful for the engineer or NPP operator to evaluate the fire-damaged cabinet strength under seismic excitation. This capacity model is presented in terms of the High Confidence of Low Probability of Failure (HCLPF) point. The results are validated by the proper judgment and can be used to analyze the influences of fire on the electrical cabinet.

반도체부품 수요 및 납기 불확실성을 고려한 안전재고 설정 프레임워크 (Safety Stock Management Framework for Semiconductor Enterprises Under Demand and Lead Time Uncertainties)

  • 황호신;김수영;오진우;정세진;박인범
    • 반도체디스플레이기술학회지
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    • 제22권2호
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    • pp.104-111
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    • 2023
  • The semiconductor industry, which relies on global supply chains, has recently been facing longer lead time for material procurement due to supply chain uncertainties. Moreover, since increasing customer satisfaction and reducing inventory costs are in a trade-off relationship, it is challenging to determine the appropriate safety stock level under demand and lead time uncertainties. In this paper, we propose a framework for determining safety stock levels by utilizing the optimization method to determine the optimal safety stock level. Additionally, we employ a linear regression method to analyze customer satisfaction scores and inventory costs based on variations in lead time and demand. To verify the effectiveness of the proposed framework, we compared safety stock levels obtained by the regression equations with those of the conventional method. The numerical experiments demonstrated that the proposed method successfully reduces inventory costs while maintaining the same level of customer satisfaction when lead time increases.

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독일 신표현주의와 중국 현대 수묵의 상통성 (The commonality between German Neo-expressionism and Chinese Modern ink painting)

  • 리칭;홍순환
    • 문화기술의 융합
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    • 제9권3호
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    • pp.509-518
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    • 2023
  • 독일 신표현주의와 중국 현대 수묵은 지리적으로 멀리 떨어진 두 나라에서 시작됐으나, 등장한 시기가 유사하며 서로 공통되는 부분이 많다.창작 태도 측면에서 두 풍격의 예술가들은 모두 외래 풍격을 받아들이고 저항하며 과거로 회귀하고 전통을 초월하여 포스트모던의 불확실성을 함께 드러내고 있다. 표현 형식 측면에서 보면, 두 화풍이 그리는 대상은 모두 형상을 갖추고 있으나 사실적이지는 않으며, 매개의 재료 특성을 활용하는 것을 중요하게 여긴다. 정신적 함의 측면에서 보면, 신표현주의와 현대 수묵은 모두 사회적 관심사를 중시하고, 상통하며 유동적인 현대성을 지닌다. 독일 신표현주의와 중국 현대 수묵의 상통성은 차이점을 지우자는 것이 아니라 차이점과 공통점이 공존할 수 있도록 해야 한다는 것이다.

국제장기상거래계약에서의 재협상 및 계약변경에 관한 연구: 원계약 상 관련 조항이 포함되지 않은 계약을 중심으로 (A Study on the Renegotiation and Adaptation of International Long Term Commercial Contracts: Focusing on the Contracts without the Renegotiating Clauses)

  • 윤주영
    • 무역학회지
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    • 제45권5호
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    • pp.117-139
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    • 2020
  • In case of international long-term transactions, there are various risks of economic change of circumstances including skyrocketing price increase and shortage of raw material, as well as force majeure in a general sense. Nevertheless, pretty many of international long-term commercial contracts do not include the provisions of renegotiation and adaptation of the contract. In this case, possibility of renegotiation and adaptation depends mainly on the applicable law. Namely, it may be possible or not, according to choice of law. The reason is that national laws have nuances each other, and most of national courts are traditionally reluctant to accept hardship. and also, provisions of international uniform law (CISG) has ambiguity and inflexibility in relation to the problems of change of circumstances. Accordingly, this paper analyzes comparatively the doctrines and provisions related to renegotiation and adaptation of contracts of the most representative countries such as England, U.S.A., France, Germany as well as provisions CISG and soft law such as PICC. By doing so, the author makes clear which laws of instruments is more flexible or acceptable in allowing renegotiation and adaptation of long-term commercial contracts, and emphasizes on the importance of inclusion of express terms by using other alternative supplementing clauses, as a best solution for settling the problems of legal uncertainty of contract in relation to renegotiation and adaptation.

PRODUCTIVITY PREDICTION MODEL BASED ON PRODUCTIVION INFLUENCING FACTORS: FOCUSED ON FORMWORK OF RESIDENTIAL BUILDING

  • Byungki Kwon;Hyun-soo Lee;Moonseo Park;Hyunsoo Kim
    • 국제학술발표논문집
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    • The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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    • pp.58-65
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    • 2011
  • Construction Productivity is one of the most important elements in construction management. It is used in construction process scheduling and cost management, which are significant sector in construction management. It is important to make appropriate schedule and monitor how works are done within schedule. But construction project contains uncertainty and inexactitude, modifying construction schedule is being an issue to manage construction works well. Even though prediction and monitoring of productivity can be principal activity, it is hard to predict productivity with manager's experience and a standard of estimate. A large number of factors influencing productivity, such as drawing, construction method, weather, labor, material, equipment, etc. But current calculation of productivity depends on empirical probability, not consider difference of each influencing factor. In this research, the aim is to present a productivity predicting regression model of form work, which includes effectiveness of influences factors. 5 variables existed inside form work are selected by interview and site research based on literature review of existed various productivity influencing factors. The effectiveness and correlation of productivity influencing factors are analyzed by statistical approach, and it is used to make productivity regression model. The finding of this research will improves monitoring and controlling of project schedule in construction phase.

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