• Title/Summary/Keyword: Calculation model

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Applying the Schema Matching Method to XML Semantic Model of Steelbox-bridge's Structural Calculation Reports (강박스교 구조계산서 XML 시맨틱 모델의 스키마 매칭 기법 적용)

  • Yang Yeong-Ae;Kim Bong-Geun;Lee Sang-Ho
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.680-687
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    • 2005
  • This study presents a schema matching technique which can be applied to XML semantic model of structural calculation reports of steel-box bridges. The semantic model of structural calculation documents was developed by extracting the optimized common elements from the analyses of various existing structural calculation documents, and the standardized semantic model was schematized by using XML Schema. In addition, the similarity measure technique and the relaxation labeling technique were employed to develop the schema matching algorithm. The former takes into account the element categories and their features, and the latter considers the structural constraints in the semantic model. The standardized XML semantic model of steel-box bridge's structural calculation documents called target schema was compared with existing nonstandardized structural calculation documents called primitive schema by the developed schema matching algorithm Some application examples show the importance of the development of standardized target schema for structural calculation documents and the effectiveness and efficiency of schema matching technique in the examination of the degree of document standardization in structural calculation reports.

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Fire design of concrete encased columns: Validation of an advanced calculation model

  • Zaharia, R.;Dubina, D.
    • Steel and Composite Structures
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    • v.17 no.6
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    • pp.835-850
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    • 2014
  • The fire resistance of composite steel and concrete structures may be determined by using the simplified methods provided in EN 1994-1-2. For the particular situations not covered by the standard, an advanced calculation model might be applied, using special purpose programs for the analysis of structures in fire. The validation of these programs has always been an important issue for software developers, but also for designers and authorities. Clause 4.4.4 from EN 1994-1-2 refers to the validation of the advanced calculation models and states that these models must be validated through relevant test results. The paper presents the calculation of fire resistance of the composite columns in a high-rise building built in Romania, and focusses on the validation of the calculation model (computer program SAFIR), for this particular case. This validation, asked by the Romanian authorities, considers the available experimental results of a fire test, performed on a similar composite steel-concrete column.

Numerical calculation method for response of friction pendulum system when XY shear keys are sheared asynchronously

  • Wei, Biao;Fu, Yunji;Jiang, Lizhong;Li, Shanshan
    • Structural Engineering and Mechanics
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    • v.81 no.5
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    • pp.591-606
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    • 2022
  • When the friction pendulum system and shear keys work together to resist the ground motion, which inclined inputs (non 45°) to the bridge structure, the shear keys in XY direction will be sheared asynchronously, endowed the friction pendulum system with a violent curvilinear motion on the sliding surface during earthquakes. In view of this situation, firstly, this paper abandons the equivalent linearization model of friction and constructs a Spring-Coulomb friction plane isolation system with XY shear keys, and then makes a detailed mechanical analysis of the movement process of friction pendulum system, next, this paper establishes the mathematical model of structural time history response calculation by using the step-by-step integration method, finally, it compiles the corresponding computer program to realize the numerical calculation. The results show that the calculation method in this paper takes advantage of the characteristic that the friction force is always µmg, and creatively uses the "circle making method" to express the change process of the friction force and resultant force of the friction pendulum system in any calculation time step, which can effectively solve the temporal nonlinear action of the plane friction; Compared with the response obtained by the calculation method in this paper, the peak values of acceleration response and displacement response calculated by the unidirectional calculation model, which used in the traditional research of the friction pendulum system, are smaller, so the unidirectional calculation model is not safe.

Intermittent Heating and Cooling Load Calculation Method -Comparing with ISO 13790

  • Lee, Sang-Hoon
    • Architectural research
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    • v.14 no.1
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    • pp.11-18
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    • 2012
  • College of Architecture, Georgia Institute of Technology, Atlanta, GA, US Abstract The intermittent heating and cooling energy need calculation of the ISO 13790 monthly method was examined. The current ISO 13790 method applies a reduction factor to the continuous heating and cooling need calculation result to derive the intermittent heating and cooling for each month. This paper proposes a method for the intermittent energy need calculation based on the internal mean temperature calculation. The internal temperature calculation procedure was introduced considering the heat-balance taking into account of heat gain, heat loss, and thermal inertia for reduced heating and cooling period. Then, the calculated internal mean temperature was used for the intermittent heating and cooling energy need calculation. The calculation results from the proposed method were compared to the current ISO 13790 method and validated with a dynamic simulation using EnergyPlus. The study indicates that the intermittent heating and cooling energy need calculation method using the proposed model improves transparency of the current ISO 13790 method and draws more rational outcomes in the monthly heating and cooling energy need calculation.

Investigation of the Dynamic Properties of Railway Tracks using a Model for Calculation of Generation of Wheel/Rail Noise

  • Koh, Hyo-In;Nordborg, Anders
    • International Journal of Railway
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    • v.7 no.4
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    • pp.109-116
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    • 2014
  • For optimization of a low-noise track system, rail vibration and noise radiation needs to be investigated. The main influencing parameters for the noise radiation and the quantitative results of every track system can be obtained using a calculation model of generation and radiation of railway noise. This kind of model includes contact modeling and the calculation model of the dynamic properties of the wheel and the rail. This study used a nonlinear wheel/rail interaction model in the time domain to investigate the excitation of the rolling noise. Wheel/rail response is determined by time integrating Green's function of the rail together with force impulses from the wheel/rail contact. This model and the results of the study can be used for supporting calculation with the conventional model by an addition of the contributions due to nonlinearities to the roughness spectrum.

Space Radiation Shielding Calculation by Approximate Model for LEO Satellites

  • Shin Myung-Won;Kim Myung-Hyun
    • Nuclear Engineering and Technology
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    • v.36 no.1
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    • pp.1-11
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    • 2004
  • Two approximate methods for a cosmic radiation shielding calculation in low earth orbits were developed and assessed. Those are a sectoring method and a chord-length distribution method. In order to simulate a change in cosmic radiation environments along the satellite mission trajectory, IGRF model and AP(E)-8 model were used. When the approximate methods were applied, the geometrical model of satellite structure was approximated as one-dimensional slabs, and a pre-calculated dose-depth conversion function was introduced to simplify the dose calculation process. Verification was performed with mission data of KITSAT-1 and the calculated results were also compared with detailed 3-dimensional calculation results using Monte Carlo calculation. Dose results from the approximate methods were conservatively higher than Monte Carlo results, but were lower than experimental data in total dose rate. Differences between calculation and experimental data seem to come from the AP-8 model, for which it is reported that fluxes of proton are underestimated. We confirmed that the developed approximate method can be applied to commercial satellite shielding calculations. It is also found that commercial products of semi-conductors can be damaged due to total ionizing dose under LEO radiation environment. An intensive shielding analysis should be taken into account when commercial devices are used.

Decision-Making Model Research for the Calculation of the National Disaster Management System's Standard Disaster Prevention Workforce Quota : Based on Local Authorities

  • Lee, Sung-Su;Lee, Young-Jai
    • Journal of Information Technology Applications and Management
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    • v.17 no.3
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    • pp.163-189
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    • 2010
  • The purpose of this research is to develop a decision-making model for the calculation of the National Disaster Management System's standard prevention workforce quota. The final purpose of such model is to support in arranging a rationally sized prevention workforce for local authorities by providing information about its calculation in order to support an effective and efficient disaster management administration. In other words, it is to establish and develop a model that calculates the standard disaster prevention workforce quota for basic local governments in order to arrange realistically required prevention workforce. In calculating Korea's prevention workforce, it was found that the prevention investment expenses, number of prevention facilities, frequency of flood damage, number of disaster victims, prevention density, and national disaster recovery costs have positive influence on the dependent variable when the standard prevention workforce was set as the dependent variable. The model based on the regression analysis-which consists of dependent and independent variables-was classified into inland mountainous region, East coast region, Southwest coastal plain region to reflect regional characteristics for the calculation of the prevention workforce. We anticipate that the decision-making model for the standard prevention workforce quota will aid in arranging an objective and essential prevention workforce for Korea's basic local authorities.

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Calculation of fuel temperature profile for heavy water moderated natural uranium oxide fuel using two gas mixture conductance model for noble gas Helium and Xenon

  • Jha, Alok;Gupta, Anurag;Das, Rajarshi;Paraswar, Shantanu D.
    • Nuclear Engineering and Technology
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    • v.52 no.12
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    • pp.2760-2770
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    • 2020
  • A model for calculation of fuel temperature profile using binary gas mixture of Helium and Xenon for gap gas conductance is proposed here. In this model, the temperature profile of a fuel pencil from fuel centreline to fuel surface has been calculated by taking into account the dilution of Helium gas filled during fuel manufacturing due to accumulation of fission gas Xenon. In this model an explicit calculation of gap gas conductance of binary gas mixture of Helium and Xenon has been carried out. A computer code Fuel Characteristics Calculator (FCCAL) is developed for the model. The phenomena modelled by FCCAL takes into account heat conduction through the fuel pellet, heat transfer from pellet surface to the cladding through the gap gas and heat transfer from cladding to coolant. The binary noble gas mixture model used in FCCAL is an improvement over the parametric model of Lassmann and Pazdera. The results obtained from the code FCCAL is used for fuel temperature calculation in 3-D neutron diffusion solver for the coolant outlet temperature of the core at steady operation at full power. It is found that there is an improvement in calculation time without compromising accuracy with FCCAL.

Hardware Implementation on the Weight Calculation of Iterative Algorithm for CT Image Reconstruction

  • Cao, Xixin;Ma, Kaisheng;Lian, Renchun;Zhang, Qihui
    • ETRI Journal
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    • v.35 no.5
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    • pp.931-934
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    • 2013
  • The weight calculation in an iterative algorithm is the most computationally costly task in computed tomography image reconstruction. In this letter, a fast algorithm to speed up the weight calculation is proposed. The classic square pixel rotation approximate calculation method for computing the weights in the iterative algorithm is first analyzed and then improved by replacing the square pixel model with a circular pixel model and the square rotation approximation with a segmentation method of a circular area. Software simulation and hardware implementation results show that our proposed scheme can not only improve the definition of the reconstructed image but also accelerate the reconstruction.

A Delay Estimation Method using Reduced Model of RLC Interconnects (RLC 연결선의 축소모형을 이용한 지연시간 계산방법)

  • Jung Mun-Sung;Kim Ki-Young;Kim Seok-Yoon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.8
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    • pp.350-354
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    • 2005
  • This paper proposes a new method for delay time calculation in RLC interconnects. This method is simple, but precise. The proposed method can calculate delay time of RLC interconnects by simple numerical formula calculation without complex moment calculation using reduced model in RLC interconnects. The results using the proposed method for RLC circuits show that average relative error is within $10\%$ in comparison with HSPICE simulation results.