• Title/Summary/Keyword: rational method

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Hybrid of topological derivative-based level set method and isogeometric analysis for structural topology optimization

  • Roodsarabi, Mehdi;Khatibinia, Mohsen;Sarafrazi, Seyyed R.
    • Steel and Composite Structures
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    • v.21 no.6
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    • pp.1389-1410
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    • 2016
  • This paper proposes a hybrid of topological derivative-based level set method (LSM) and isogeometric analysis (IGA) for structural topology optimization. In topology optimization a significant drawback of the conventional LSM is that it cannot create new holes in the design domain. In this study, the topological derivative approach is used to create new holes in appropriate places of the design domain, and alleviate the strong dependency of the optimal topology on the initial design. Furthermore, the values of the gradient vector in Hamilton-Jacobi equation in the conventional LSM are replaced with a Delta function. In the topology optimization procedure IGA based on Non-Uniform Rational B-Spline (NURBS) functions is utilized to overcome the drawbacks in the conventional finite element method (FEM) based topology optimization approaches. Several numerical examples are provided to confirm the computational efficiency and robustness of the proposed method in comparison with derivative-based LSM and FEM.

PRELIMINARY PROJECT OF WATER SUPPLY FOR NDATA FARM, MALAWA

  • Min-Shun Lee;Hung-Kwai Chen;Sheng Liang;Ho-Shong Hou
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1615-1617
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    • 2009
  • The water resources project of 320 Ha second stage reclamation, in which including an University City, out of 800 Ha Ndata Farm, Malawa, had been under studied in this research. The challenge of C value of runoff coefficient was obtained as 0.8, by introducing the attenuation factors method, proposed by second author, an IDF dimensionless method customary used in Taiwan, proposed by the third author, is translated further to solve the project design rainfall; Rational Method, thus, obtains 11.5 CMS as the 5 year recurrence storage. The final job, completed by the third author's on-site performance, includs field alignments and discussions with the trustee, Malawa President H. E. Dr. Bingu Wa Mutharika, when a special concern of anti-theft. In order to provide sufficient supply up to an amount of 44,000 M3 during April to November, the sketch package includes 6 measurements: one water barrage, one sluice gate, one intake, one sediment reservoir, one water reservoir, and 3199 Km long gravity-driving hydraulic pipe.

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Research about the development of education courses for nurturing digital forensic experts (디지털 포렌식 전문인력 양성 교육과정 개선에 관한 연구)

  • Kim, Jong Min;Choi, Kyong Ho;Kim, Kuinam J.
    • Convergence Security Journal
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    • v.12 no.5
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    • pp.79-85
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    • 2012
  • This research is to improve the education courses for nurturing digital forensic exports. To do so, the education courses for nurturing digital forensic exports were proposed and surveys targeting forensic professionals are conducted. Using AHP method, the most rational and important education courses among aspects (forensic introduction, system forensic, theories and analyses by categories, tool using, and research work) were drawn from results from the above. From this research, it is to improve the education courses for nurturing digital forensic experts applying rational courses with high status.

Development of Rating System for Highway Bridges (도로교 내하급수 판정시스템 개발)

  • Cho, Hyo Nam;Chang, Dong Il;Lee, Hee Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.4
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    • pp.9-15
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    • 1991
  • This study is directed for the development of rational rating models for realistic safety assessment and the computer rating system for highway bridges. For this purpose, the conventional rating system is considerably improved in appropriate way, and a rational rating system based on the reliabilty method is proposed to estimate safety of deteriorated bridges by using only the visual inspection data or the statistical data available. In addition. the rating system which can assess the realistic allowable passing tonnage of military vehicles in case of the military operations is also presented. From this study, it is known that the presented rating system and the computer program BRS(Bridge Rating System) provide an effective tool which can handle the degree of deterioration and various uncertainities of the bridge systematically. so it can be used widely for assessment of safety and load carrying capacity of existing deteriorated or damaged bridges.

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Land Suitability Classification for Rational Land Use Planning in County(Gun) Area(II) Determination of the land Use Suitability to Integrate the Classified Values - (군단위지역 토지이용계획의 합리적 책정을 위한 토지적성구분(II) - 토지이용적성의 종합화 방안 -)

  • Hwang, Han-Cheol;Choe, Su-Myeong;Han, Gyeong-Su
    • Journal of Korean Society of Rural Planning
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    • v.2 no.1
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    • pp.31-38
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    • 1996
  • As a rational decision-making process of county-level area development, this study designed 3-step framework : function-giving(areal analysis) on unit planning area by decision matrix of land suitability, check of typical characteristics of each function area and formulation of its future development strategies. Two alternatives were suggested as the areal analysis method, of which one is equal ordering / valuing technique of checking indices for land suitability classfication and the other preferential weighting technique. And then, under the algorithm specially defined in this study, land suitability maps(Fig.2,3) of the case study area (Seungju-county area, Chonnam-province, Korea) were drawn from the areal analysis results. By use of land suitability classification results, unique characteristics of typical function areas were defined (on 7 types of alternative 1 , 8 types of II ) and their future development strategies were formulated in the case study area, According to the categorization criteria in this study, all the villages of the case area were classfied as a suitable type of function areas illustrated in this study.

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Improving Catalytic Efficiency and Changing Substrate Spectrum for Asymmetric Biocatalytic Reductive Amination

  • Jiang, Wei;Wang, Yali
    • Journal of Microbiology and Biotechnology
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    • v.30 no.1
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    • pp.146-154
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    • 2020
  • With the advantages of biocatalytic method, enzymes have been excavated for the synthesis of chiral amino acids by the reductive amination of ketones, offering a promising way of producing pharmaceutical intermediates. In this work, a robust phenylalanine dehydrogenase (PheDH) with wide substrate spectrum and high catalytic efficiency was constructed through rational design and active-site-targeted, site-specific mutagenesis by using the parent enzyme from Bacillus halodurans. Active sites with bonding substrate and amino acid residues surrounding the substrate binding pocket, 49L-50G-51G, 74M,77K, 122G-123T-124D-125M, 275N, 305L and 308V of the PheDH, were identified. Noticeably, the new mutant PheDH (E113D-N276L) showed approximately 6.06-fold increment of kcat/Km in the oxidative deamination and more than 1.58-fold in the reductive amination compared to that of the wide type. Meanwhile, the PheDHs exhibit high capacity of accepting benzylic and aliphatic ketone substrates. The broad specificity, high catalytic efficiency and selectivity, along with excellent thermal stability, render these broad-spectrum enzymes ideal targets for further development with potential diagnostic reagent and pharmaceutical compounds applications.

Efficient Digitizing in Reverse Engineering By Sensor Fusion (역공학에서 센서융합에 의한 효율적인 데이터 획득)

  • Park, Young-Kun;Ko, Tae-Jo;Kim, Hrr-Sool
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.9
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    • pp.61-70
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    • 2001
  • This paper introduces a new digitization method with sensor fusion for shape measurement in reverse engineering. Digitization can be classified into contact and non-contact type according to the measurement devices. Important thing in digitization is speed and accuracy. The former is excellent in speed and the latter is good for accuracy. Sensor fusion in digitization intends to incorporate the merits of both types so that the system can be automatized. Firstly, non-contact sensor with vision system acquires coarse 3D point data rapidly. This process is needed to identify and loco]ice the object located at unknown position on the table. Secondly, accurate 3D point data can be automatically obtained using scanning probe based on the previously measured coarse 3D point data. In the research, a great number of measuring points of equi-distance were instructed along the line acquired by the vision system. Finally, the digitized 3D point data are approximated to the rational B-spline surface equation, and the free-formed surface information can be transferred to a commercial CAD/CAM system via IGES translation in order to machine the modeled geometric shape.

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The Effects of Organizational Culture Types and Perceived Organizational Support on the Organizational Commitment of Firefighters (소방공무원의 조직문화 유형과 조직지원인식이 조직몰입에 미치는 영향)

  • Choi, Hee-Chul
    • Fire Science and Engineering
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    • v.34 no.1
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    • pp.115-120
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    • 2020
  • This study aimed to assist the improvement of organizational commitment and the preparation of an action plan regarding support from the organization by examining the effects of organizational culture types and perceived organizational support on firefighters' organizational commitment. To this end, 205 fire-fighting officers from the northern area of Gyeonggi-do were surveyed using the purposive sampling method. The results demonstrated that among organizational culture types, the perception of group culture, rational culture, and organizational support held by firefighters had a significant influence on their organizational commitment. Based on these results, this study suggested various support plans at the organizational level for stimulating group culture and rational culture among firefighters, and improving organizational commitment.

Modeling Methods for SPOT-5 HRG Stereo Pair Images (SPOT-5(HRG) 입체위성영상의 3차원 모델링 기법 연구)

  • 최선용;신대식;이용웅
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.3
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    • pp.255-260
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    • 2003
  • In this paper, we generate the 3D geometric sensor model of SPOT-5 HRG stereo images which are processed in Supermode and have 2.5m ground spatial resolution, and calculate the RPC(Rational Polynomial Coefficients) for acquisition of topographic information using the exterior orientation parameters which are determined in the 3D geometric sensor modelling process. It is shown that SPOT-5 images can be modelled with me 3.3m accuracy by the bundle adjustment method used to model the existing SPOT series. Considering the accuracy of RPC's results with rmse 0.03m accuracy, the RPC model can replace the sensor model, if we emphasize the simplification and the cost.

Practical investigation of a monopod fabrication method and the numerical investigation of its up-righting process

  • Hafez, Khaled A.;Ismael, Maged M.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.3
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    • pp.431-453
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    • 2013
  • The principal purpose of this paper is to present a novel two phases rational scenario applied in constructing an offshore monopod platform; in which the two phases are the all-ground horizontal construction phase and the post-construction phase. Concerning the all-ground construction phase, a brief investigation of its different stages, i.e., pre-fabrication, fabrication, pre-assembling, positioning, assembling, and surface finishing is introduced. The important practical aspects of such construction phase are investigated without going into the nitty-gritty of the details involved therein. Concerning the post-construction phase, a clear investigation of its sequential stages, i.e., lifting, moving and up-righting is introduced. A finite element model (FEM) of the monopod platform is created to perform the structural analysis necessary to decide the suspension points/devices and the handling scenario during the various stages of the post-construction phase on a rational wise. Such structural analysis is performed within the framework of the three dimensional quasi-static modeling and analysis aiming at simulating the realistic handling condition, and hence introducing a reliable physical interpretation of the numerical results. For the whole effort to be demonstrated efficiently, the results obtained are analyzed, the conclusions are presented, and few related recommendations are suggested.