• Title/Summary/Keyword: Double-integration

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Development of Realtime Simulator for Multibody Dynamics Analysis of Wheeled Vehicle on Soft Soil (연약지반을 고려한 차량 실시간 시뮬레이터 개발)

  • Hong, Sup;Kim, Hyung-Woo;Cho, Yun-Sung;Cho, Hui-Je;Jung, Ji-Hyun;Bae, Dae-Sung
    • Journal of Ocean Engineering and Technology
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    • v.25 no.6
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    • pp.116-122
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    • 2011
  • A realtime simulator using an explicit integration method is introduced to improve the solving performance for the dynamic analysis of a wheeled vehicle. Because a full vehicle system has many parts, the development of a numerical technique for multiple d.o.f. and ground contacts has been required to achieve a realtime dynamics analysis. This study proposes an efficient realtime solving technique that considers the wheeled vehicle dynamics behavior with full degrees of freedom and wheel contact with soft ground such as sand or undersea ground. A combat vehicle was developed to verify this method, and its dynamics results are compared with commercial programs using implicit integration methods. The combat vehicle consists of a chassis, double wishbone type front and rear suspension, and drive train. Some cases of vehicle dynamics analysis are carried out to verify the realtime ratio.

Research on the Effects of Knowledge Management Capabilities and Knowledge Sharing Mechanisms on New Product Development Performance in Taiwan's High-tech Industries

  • Liu, Pang-Lo;Tsai, Chih-Hung
    • International Journal of Quality Innovation
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    • v.8 no.2
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    • pp.69-87
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    • 2007
  • High-tech industries in Taiwan exist in an environment with diverse product requirements and intense cost reduction and information integration stress. They must develop new operational directions to increase industry competitiveness. Therefore, Taiwan's high-tech industries must continue R&D and creativity, establish knowledge sharing mechanisms and improve new product development (NPD) performance. This research analyzed and explored the influences of knowledge management (KM) and knowledge sharing mechanisms introduced by Taiwan's high-tech industries on new product development performance. The relationship between knowledge management capabilities and NPD performance is studied. This research considers the intervening industry and corporate position variables. Taiwan's high-tech industries have gradually entered the era of IT region integration and application with competitive advantage creation based upon core techniques. The in-depth study of knowledge management and knowledge sharing introduced by the high-tech industry revealed double meanings in academic and practical applications. The research results showed the following: (1) the stronger the knowledge management capabilities of Taiwan's high-tech industries, the more significant the NPD performance. (2) The better the knowledge sharing mechanism in Taiwan's high-tech industries, the more significant the NPD performance. (3) Corporate scale is not necessarily the critical factor in NPD success and the influence of corporate scale on NPD performance did not show significant differences. (4) The stronger the degree of leading corporate techniques, the more significant the NPD performance.

A Study on The Architectural Plan Access Method for The Integrated Design of The Environmentally Friendly Architecture (친환경 건축의 통합설계를 위한 건축 계획적 접근방법에 관한 연구)

  • Cho, Sung-Hyun;Kim, Chul-Kyu
    • Journal of The Korean Digital Architecture Interior Association
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    • v.10 no.3
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    • pp.79-86
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    • 2010
  • From the research which sees the building which uses a natural control method with ecological architecture, continuity tried to divide the building which uses a physical control method with sustainable architecture. Ecological architecture analyzes the microclimate of the area and applies mining and natural ventilation leads and that the interior environment controls, the condition of the site actively and there is a possibility of seeing. Also sustainable architecture which is possible to lead and recycling and reuse of the resources and energy cyclic process of the construction resources to lead and the interior environment to control. Therefore the case where the facility system and structural system become integrated design organically in natural circulating method is many. Specially the sunshade system and double skin system are combined and structural system of the building and there is a possibility of having the envelope which form is feature. Today the buildings lead and the system integration process where the integral parts are systematic is demanded the interior environment which and an external form and that, they make they are there is a possibility of seeing. the environmental building which hits joins in with natural control method and the structure and facility system are integrated and has the tendency which is developed and there is a possibility of saying that a meaning with the alternative construction will be able to reduce the resources and an energy.

Time-domain hybrid method for simulating large amplitude motions of ships advancing in waves

  • Liu, Shukui;Papanikolaou, Apostolos D.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.3 no.1
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    • pp.72-79
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    • 2011
  • Typical results obtained by a newly developed, nonlinear time domain hybrid method for simulating large amplitude motions of ships advancing with constant forward speed in waves are presented. The method is hybrid in the way of combining a time-domain transient Green function method and a Rankine source method. The present approach employs a simple double integration algorithm with respect to time to simulate the free-surface boundary condition. During the simulation, the diffraction and radiation forces are computed by pressure integration over the mean wetted surface, whereas the incident wave and hydrostatic restoring forces/moments are calculated on the instantaneously wetted surface of the hull. Typical numerical results of application of the method to the seakeeping performance of a standard containership, namely the ITTC S175, are herein presented. Comparisons have been made between the results from the present method, the frequency domain 3D panel method (NEWDRIFT) of NTUA-SDL and available experimental data and good agreement has been observed for all studied cases between the results of the present method and comparable other data.

A Comparative Analysis of the Functional Values for Wastewater Treatment and Atmospheric Regulation in Coastal Wetland and Rice Paddy Ecosystems (갯벌과 간척농지의 수질 및 대기조절가치의 비교분석)

  • Pyo, Hee-Dong
    • Environmental and Resource Economics Review
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    • v.10 no.1
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    • pp.95-126
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    • 2001
  • Functional values for wastewater treatment and atmospheric regulation in coastal wetland and rice paddy ecosystems are quantified, and an illustration is given on how to integrate biophysical parameters into a valuation framework. This is one of most controversial issues in economic analysis for wetland preservation versus wetland conversion to agricultural use. This paper includes theoretical considerations for estimating functional values of environmental ecosystems, and the integration of biophysical data and replacement cost method employed. Specific physical and geographical characteristics and data on ecosystem functions and services in coastal wetlands and rice paddies are addressed for evaluating their values in economic terms. In particular this paper indicates double counting problems and overestimation in the previous studies, and demonstrates how to avoid them and to maintain the consistency of valuation process involving a least-cost method, thus enables an accurate integration of the coastal wetland ecology and wetland economics. As a result which is far away from the previous studies, the total economic present value of wastewater assimilation by coastal wetland is estimated at 7,484,640 won/ha, and the net present value of positive effect for atmospheric regulation, negative effects for air pollution and water pollution by rice paddy is estimated at -37,934 won/ha, assuming that resources are infinitely long-lived and the annual value and the rate of discount (10%) is constant every year. In conclusion, for further reliability and validity of functional values for natural resources it is very noteworthy that a general equilibrium framework that could directly incorporate the interdependence between ecosystem functions and services would be preferred to the partial equilibrium framework.

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New GPU computing algorithm for wind load uncertainty analysis on high-rise systems

  • Wei, Cui;Luca, Caracoglia
    • Wind and Structures
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    • v.21 no.5
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    • pp.461-487
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    • 2015
  • In recent years, the Graphics Processing Unit (GPU) has become a competitive computing technology in comparison with the standard Central Processing Unit (CPU) technology due to reduced unit cost, energy and computing time. This paper describes the derivation and implementation of GPU-based algorithms for the analysis of wind loading uncertainty on high-rise systems, in line with the research field of probability-based wind engineering. The study begins by presenting an application of the GPU technology to basic linear algebra problems to demonstrate advantages and limitations. Subsequently, Monte-Carlo integration and synthetic generation of wind turbulence are examined. Finally, the GPU architecture is used for the dynamic analysis of three high-rise structural systems under uncertain wind loads. In the first example the fragility analysis of a single degree-of-freedom structure is illustrated. Since fragility analysis employs sampling-based Monte Carlo simulation, it is feasible to distribute the evaluation of different random parameters among different GPU threads and to compute the results in parallel. In the second case the fragility analysis is carried out on a continuum structure, i.e., a tall building, in which double integration is required to evaluate the generalized turbulent wind load and the dynamic response in the frequency domain. The third example examines the computation of the generalized coupled wind load and response on a tall building in both along-wind and cross-wind directions. It is concluded that the GPU can perform computational tasks on average 10 times faster than the CPU.

Response of double hinged articulated tower platforms to wind forces

  • Islam, Nazrul;Zaheer, Mohd Moonis;Ahmed, Suhail
    • Wind and Structures
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    • v.12 no.2
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    • pp.103-120
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    • 2009
  • Articulated tower platforms due to its compliant nature are more susceptible to the dynamic effects of wind than conventional fixed platforms. Dynamic response analysis of a double hinged articulated tower excited by low frequency wind forces with random waves is presented in this paper. The exposed super structure of the platform, housing the drilling and production facilities is subjected to mean and fluctuating wind loads, while the submerged portion is acted upon by wind driven waves. The fluctuating component of the wind velocity is modeled by Emil Simiu's spectrum, while the sea state is characterized by Pierson-Moskowitz spectrum. Nonlinearities in the system due to drag force, added mass, variable submergence and instantaneous tower orientation are considered in the analysis. To account for these nonlinearities, an implicit time integration scheme (Newmark's-${\beta}$) has been employed which solves the equation of motion in an iterative fashion and response time histories are obtained. The power spectra obtained from random response time histories show the significance of low frequency responses.

Study of the dynamic behavior of porous functionally graded suspension structural systems using finite elements method

  • Ayman E., Nabawy;Ayman M.M., Abdelhaleem;Soliman. S., Alieldin;Alaa A., Abdelrahman
    • Steel and Composite Structures
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    • v.45 no.5
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    • pp.697-713
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    • 2022
  • In the context of the finite elements method, the dynamic behavior of porous functionally graded double wishbone vehicle suspension structural system incorporating joints flexibility constraints under road bump excitation is studied and analyzed. The functionally graded material properties distribution through the thickness direction is simulated by the power law including the porosity effect. To explore the porosity effects, both classical and adopted porosity models are considered based on even porosity distribution pattern. The dynamic equations of motion are derived based on the Hamiltonian principle. Closed forms of the inertia and material stiffness components are derived. Based on the plane frame isoparametric Timoshenko beam element, the dynamic finite elements equations are developed incorporating joint flexibilities constraints. The Newmark's implicit direct integration methodology is utilized to obtain the transient vibration time response under road bump excitation. The presented procedure is validated by comparing the computational model results with the available numerical solutions and an excellent agreement is observed. Obtained results show that the decrease of porosity percentage and material graduation tends to decrease the deflection as well as the resulting stresses of the control arms thus improving the dynamic performance and increasing the service lifetime of the control arms.

Capacitance Enhancement and Evaluation of Gold-Deposited Carbon Nanotube Film Ion-Selective Electrode (금 입자 증착된 탄소나노튜브의 커패시턴스 증가 및 박막형 이온 선택성 전극으로서의 특성 평가)

  • Do Youn Kim;Hanbyeol Son;Hyo-Ryoung Lim
    • Journal of Powder Materials
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    • v.30 no.4
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    • pp.310-317
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    • 2023
  • Small-film-type ion sensors are garnering considerable interest in the fields of wearable healthcare and home-based monitoring systems. The performance of these sensors primarily relies on electrode capacitance, often employing nanocomposite materials composed of nano- and sub-micrometer particles. Traditional techniques for enhancing capacitance involve the creation of nanoparticles on film electrodes, which require cost-intensive and complex chemical synthesis processes, followed by additional coating optimization. In this study, we introduce a simple one-step electrochemical method for fabricating gold nanoparticles on a carbon nanotube (Au NP-CNT) electrode surface through cyclic voltammetry deposition. Furthermore, we assess the improvement in capacitance by distinguishing between the electrical double-layer capacitance and diffusion-controlled capacitance, thereby clarifying the principles underpinning the material design. The Au NP-CNT electrode maintains its stability and sensitivity for up to 50 d, signifying its potential for advanced ion sensing. Additionally, integration with a mobile wireless data system highlights the versatility of the sensor for health applications.

A Novel Integrative Expression Vector for Sulfolobus Species

  • Choi, Kyoung-Hwa;Hwang, Sungmin;Yoon, Naeun;Cha, Jaeho
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1503-1509
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    • 2014
  • With the purpose of facilitating the process of stable strain generation, a shuttle vector for integration of genes via a double recombination event into two ectopic sites on the Sulfolobus acidocaldarius chromosome was constructed. The novel chromosomal integration and expression vector pINEX contains a pyrE gene from S. solfataricus P2 ($pyrE_{sso}$) as an auxotrophic selection marker, a multiple cloning site with histidine tag, the internal sequences of malE and malG for homologous recombination, and the entire region of pGEM-T vector, except for the multiple cloning region, for propagation in E. coli. For stable expression of the target gene, an ${\alpha}$-glucosidase-producing strain of S. acidocaldarius was generated employing this vector. The malA gene (saci_1160) encoding an ${\alpha}$-glucosidase from S. acidocaldarius fused with the glutamate dehydrogenase ($gdhA_{saci}$) promoter and leader sequence was ligated to pINEX to generate pINEX_malA. Using the "pop-in" and "pop-out" method, the malA gene was inserted into the genome of MR31 and correct insertion was verified by colony PCR and sequencing. This strain was grown in YT medium without uracil and purified by His-tag affinity chromatography. The ${\alpha}$-glucosidase activity was confirmed by the hydrolysis of $pNP{\alpha}G$. The pINEX vector should be applicable in delineating gene functions in this organism.