• 제목/요약/키워드: local derivation

검색결과 88건 처리시간 0.023초

Enhancement of Borneo's Indegenous Design

  • Rahman, Khairul Aidil Azlin Abd
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2008년도 추계학술대회
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    • pp.42-45
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    • 2008
  • Derivation of modern products from the by gone age has contributed much for the new modern living. It has been generally recognized that the various ethnicities in Borneo with different backgrounds had made Borneo a place of cultural diversity. However as time passed, most indigenous products are no longer in used or are stored in poor condition. Most products nearly aged over a century are still in a good condition with invaluable sentiments. Indigenous product is an artifact that had been designed and used by certain community of people such as tools, clothing, crafts and goods. Each design may have its own identity to the community. Some of the indigenous products which are no longer in use at present are kept by the community as their collections. The research reveals similarities in the interests of indigenous products, concerns and realities of indigenous communities from the different regions. The study suggests that learning about indigenous materials, such as hand-made products and machine-made products is necessary for the local industry to develop a product identity that is distinctly local. Most indigenous products show evidence of connections to old traditions, yet are new to the design market.

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Vibration behaviour of axially compressed cold-formed steel members

  • Silvestre, N.;Camotim, D.
    • Steel and Composite Structures
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    • 제6권3호
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    • pp.221-236
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    • 2006
  • The objective of this work is to describe the main steps involved in the derivation of a GBT (Generalised Beam Theory) formulation to analyse the vibration behaviour of loaded cold-formed steel members and also to illustrate the application and capabilities of this formulation. In particular, the paper presents and discusses the results of a detailed investigation about the local and global free vibration behaviour of lipped channel simply supported columns. After reporting some relevant earlier GBT-based results dealing with the buckling and vibration behaviours of columns and load-free members, the paper addresses mostly issues concerning the variation of the column fundamental frequency and vibration mode nature/shape with its length and axial compression level. For validation purposes, some GBT-based results are also compared with values obtained by means of 4-node shell finite element analyses performed in the code ABAQUS.

Sliding Window Filtering for Ground Moving Targets with Cross-Correlated Sensor Noises

  • Song, Il Young;Song, Jin Mo;Jeong, Woong Ji;Gong, Myoung Sool
    • 센서학회지
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    • 제28권3호
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    • pp.146-151
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    • 2019
  • This paper reports a sliding window filtering approach for ground moving targets with cross-correlated sensor noise and uncertainty. In addition, the effect of uncertain parameters during a tracking error on the model performance is considered. A distributed fusion sliding window filter is also proposed. The distributed fusion filtering algorithm represents the optimal linear combination of local filters under the minimum mean-square error criterion. The derivation of the error cross-covariances between the local sliding window filters is the key to the proposed method. Simulation results of the motion of the ground moving target a demonstrate high accuracy and computational efficiency of the distributed fusion sliding window filter.

Distributed Fusion Moving Average Prediction for Linear Stochastic Systems

  • Song, Il Young;Song, Jin Mo;Jeong, Woong Ji;Gong, Myoung Sool
    • 센서학회지
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    • 제28권2호
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    • pp.88-93
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    • 2019
  • This paper is concerned with distributed fusion moving average prediction for continuous-time linear stochastic systems with multiple sensors. A distributed fusion with the weighted sum structure is applied to the optimal local moving average predictors. The distributed fusion prediction algorithm represents the optimal linear fusion by weighting matrices under the minimum mean square criterion. The derivation of equations for error cross-covariances between the local predictors is the key of this paper. Example demonstrates effectiveness of the distributed fusion moving average predictor.

Seismic hazard and response spectrum modelling for Malaysia and Singapore

  • Looi, Daniel T.W.;Tsang, H.H.;Hee, M.C.;Lam, Nelson T.K.
    • Earthquakes and Structures
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    • 제15권1호
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    • pp.67-79
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    • 2018
  • Malaysia and Singapore have adopted Eurocode 8 (EC8) for the seismic design of building structures. The authors studied the seismic hazard modelling of the region surrounding Malaysia and Singapore for a long time and have been key contributors to the drafting of the Malaysia National Annex (NA). The purpose of this paper is to explain the principles underlying the derivation of the elastic response spectrum model for Malaysia (Peninsular Malaysia, Sarawak and Sabah). The current EC8 NA for Singapore is primarily intended to address the distant hazards from Sumatra and is not intended to provide coverage for potential local intraplate hazards. Hence, this paper recommends a reconciled elastic response spectrum for Singapore, aiming to achieve a more robust level of safety. The topics covered include the modelling of distant interplate earthquakes generated offshore and local earthquakes in an intraplate tectonic setting, decisions on zoning, modelling of earthquake recurrences, ground motion and response spectrum. Alternative expression for response spectrum on rock, strictly based on the rigid framework of EC8 is discussed.

현지 암반의 발파특성 평가를 통한 발파 설계인자 도출에 관한 연구 (A Study on the Derivation of Powder factor for Tunnel Blast Design Based on Blastability Evaluation)

  • 임경호;김준엽;임대규;신영철
    • 화약ㆍ발파
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    • 제23권3호
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    • pp.75-82
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    • 2005
  • 여러 발파공학자들이 현지 암반의 지역적 특성을 고려한 발파를 위해 적용할 수 있는 나름대로의 방법론들을 개발하고 있는 실정이다. 그러나 대부분의 방법론들이 지역적인 암반 특성을 반영할 수 있도록 체계화되어 있지 못할 뿐만 아니라 발파자의 관찰과 경험에만 주로 의존한다는 단점이 있다. 본 연구에서는 현지암반의 고유한 공학적 특성을 고려할 수 있도록 Lilly가 제안한 발파지수(blastability index) 개념을 도입하여 발파설계 인자를 도출할 수 있도록 시도하였다. 발파지수 산정 시에는 암반 자체의 공학적 특성뿐만 아니라 절리분포 특성도 반영이 되므로 현지 여건에 부합될 수 있는 발파암 분류가 가능하고, 합리적인 발파설계를 수행하는 데에 도움이 될 것으로 기대된다.

OBSTACLE SHAPE RECONSTRUCTION BY LOCALLY SUPPORTED BASIS FUNCTIONS

  • Lee, Ju-Hyun;Kang, Sungkwon
    • 호남수학학술지
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    • 제36권4호
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    • pp.831-852
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    • 2014
  • The obstacle shape reconstruction problem has been known to be difficult to solve since it is highly nonlinear and severely ill-posed. The use of local or locally supported basis functions for the problem has been addressed for many years. However, to the authors' knowledge, any research report on the proper usage of local or locally supported basis functions for the shape reconstruction has not been appeared in the literature due to many difficulties. The aim of this paper is to introduce the general concepts and methodologies for the proper choice and their implementation of locally supported basis functions through the two-dimensional Helmholtz equation. The implementations are based on the complex nonlinear parameter estimation (CNPE) formula and its robust algorithm developed recently by the authors. The basic concepts and ideas are simple. The derivation of the necessary properties needed for the shape reconstructions are elementary. However, the capturing abilities for the local geometry of the obstacle are superior to those by conventional methods, the trial and errors, due to the proper implementation and the CNPE algorithm. Several numerical experiments are performed to show the power of the proposed method. The fundamental ideas and methodologies described in this paper can be applied to many other shape reconstruction problems.

체적 밸런스 선형변환방법에 대한 연구 (On the Volumetric Balanced Variation of Ship Forms)

  • 김현철
    • 한국해양공학회지
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    • 제27권2호
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    • pp.1-7
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    • 2013
  • This paper aims at contributing to the field of ship design by introducing new systematic variation methods for ship hull forms. Hull form design is generally carried out in two stages. The first is the global variation considering the sectional area curve. Because the geometric properties of a sectional area curve have a decisive effect on the global hydrodynamic properties of ships, the design of a sectional area curve that satisfies various global design conditions, e.g., the displacement, longitudinal center of buoyancy, etc., is important in the initial hull form design stage. The second stage involves the local design of section forms. Section forms affect the local hydrodynamic properties, e.g., the local pressure in the fore- and aftbody. This paper deals with a new method for the systematic variation of sectional area curves. The longitudinal volume distribution of a ship depends on the sectional area curve, which can geometrically be controlled using parametric variation and a variation that uses the modification function. Based on these methods, we suggest a more generalized method in connection with the derivation of the lines for a new design compared to those for similar ships. This is the so-called the volumetric balanced variation (VOB) method for ship forms using a B-spline modification function and an optimization technique. In this paper the global geometric properties of hull forms are totally controlled by the form parameters. We describe the new method and some application examples in detail.

Vibration-mode-based story damage and global damage of reinforced concrete frames

  • Guo, Xiang;He, Zheng
    • Earthquakes and Structures
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    • 제14권6호
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    • pp.589-598
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    • 2018
  • An attempt is conducted to explore the relationship between the macroscopic global damage and the local damage of shear-type RC frames. A story damage index, which can be expressed as multi-variate functions of modal parameters, is deduced based on the tridiagonal matrix of the shear-type frame. The global damage model is also originated from structural modal parameters. Due to the connection of modal damage indexes, the relationship between the macroscopic global damage and the local story damage is reasonably established. In order to validate the derivation, a case study is carried out via an 8-story shear-type frame. The sensitivities of modal damage indexes to the location and severity of local story damages are studied. The evolution of the global damage is investigated as well. Results show that the global damage is sensitive to the degree of story damage, but it's not sensitive to its location. As the number of the damaged stories increases, more and more modes will be involved. Meanwhile, the global damage evolution curve changes from the concave shape to the S-type and then finally transforms into the convex shape. Through the proposed story damage, modal damage and global damage model, a multi-level damage assessment method is established.

원의 넓이에 관련된 순환논법과 국소적 조직화 (The Vicious Circle in Calculating Circle Area and the Local Organization)

  • 최영기;홍갑주
    • 대한수학교육학회지:학교수학
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    • 제8권3호
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    • pp.291-300
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    • 2006
  • 본 논문에서는 학교수학에서 발견할 수 있는 순환논법의 예로서 고등학교 미분과 적분 교과서에서 정적분을 통해 원의 넓이를 구하는 과정에서 발견되는 순환논법을 수학적으로 분석하고, 학교수학의 수준에서 원의 넓이에 관련된 몇 가지 증명방법들의 의미를 비교 분석한다. 특히 원의 넓이에 대한 아르키메데스의 증명과정을 고찰하여 학교수학에서 국소적 조직화의 의미와 가치를 재조명한다.

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