• 제목/요약/키워드: forward modeling

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Deformation prediction by a feed forward artificial neural network during mouse embryo micromanipulation

  • Abbasi, Ali A.;Vossoughi, G.R.;Ahmadian, M.T.
    • Animal cells and systems
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    • v.16 no.2
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    • pp.121-126
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    • 2012
  • In this study, a neural network (NN) modeling approach has been used to predict the mechanical and geometrical behaviors of mouse embryo cells. Two NN models have been implemented. In the first NN model dimple depth (w), dimple radius (a) and radius of the semi-circular curved surface of the cell (R) were used as inputs of the model while indentation force (f) was considered as output. In the second NN model, indentation force (f), dimple radius (a) and radius of the semi-circular curved surface of the cell (R) were considered as inputs of the model and dimple depth was predicted as the output of the model. In addition, sensitivity analysis has been carried out to investigate the influence of the significance of input parameters on the mechanical behavior of mouse embryos. Experimental data deduced by Fl$\ddot{u}$ckiger (2004) were collected to obtain training and test data for the NN. The results of these investigations show that the correlation values of the test and training data sets are between 0.9988 and 1.0000, and are in good agreement with the experimental observations.

Challenges Facing Internationalization of SMEs in Emerging Economies: A Study on OECD Model

  • SANYAL, Shouvik;HISAM, Mohammed Wamique;BAAWAIN, Ali Mohsin Salim
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.2
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    • pp.281-289
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    • 2020
  • This research analyses the challenges facing SMEs in Oman in their quest for internationalization. The study is based on the OECD Model of Internationalization put forward in the report titled "How to Foster the Internationalization of SMEs through the Pacific Alliance Integration Process" which focuses on four factors namely finance, business environment, firm capabilities and market access, which are appropriate for an emerging economy like Oman. This study used a descriptive and quantitative research design in attempting to analyze the challenges being faced by Omani SMEs in their endeavors to internationalize. The research investigates causal relationship between variables using positivist and deductive approach. Data collected from 102 respondents was analysed by Structural Equation Modeling(SEM) using AMOS. It was found that finance availability was the most significant predictor of internationalization challenges followed by market access and business environment, while firm capabilities had no impact. Thus SMEs need easier access to credit and have to develop their international business networks and their marketing capabilities in order to grow internationally. Keeping in mind the contribution made by SMEs the government has to intervene by opening up easy lines of credit to SME exporters and allowing them relaxations in customs and other duties.

Vector Network Analysis Using a One-Path, Frequency-Multiplied Photonic Link

  • Lee, Dong-Joon;Kwon, Jae-Yong;Kang, Jin-Seob;Whitaker, John F.
    • Journal of electromagnetic engineering and science
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    • v.10 no.4
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    • pp.282-289
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    • 2010
  • A simplified, practical vector network analyzer (VNA) that uses mature radio-over-fiber technology has been designed and demonstrated. The measurement concept allows the full S-parameters of a microwave device (or antenna) to be obtained while minimizing the detrimental effects of electrical cables, which are replaced with a photonic link. A variety of high-frequency light modulation schemes with frequency sweeping capabilities are presented to realize a one-path (single, forward), frequency-multiplied optical link for VNA applications. Using the photonic one-path link, full two-port S-parameters have been extracted based on five-term error modeling, which has half the error terms compared with the standard duplex configuration. The S-parameters of a microwave filter and antenna measured using frequency-multiplied optical links are found to be in good agreement with those obtained using a conventional VNA.

Influence of Adjacent Structures on Surface-Wave Dispersion Characteristics and 2-D Resistivity Structure (표면파 분산특성과 전기비저항 분포특성에 대한 인접구조물의 영향)

  • Joh, Sung-Ho;Kim, Bong-Chan;Cho, Mi-Ra;Kim, Suhk-Chol;Youn, Dae-Hee;Hong, Jae-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1318-1327
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    • 2008
  • Geotechnical sites in urban areas may have embedded structures such as utility lines and underground concrete structures, which cause difficulties in site investigation. This study is a preliminary research to establish knowledge base for developing an optimal technique for site investigation in urban areas. Surface-wave method and resistivity survey, which are frequently adopted for non-destructive site-investigation for geotechnical sites, were investigated to characterize effects of adjacent structures. In case of surface wave method, patterns of wave propagation were investigated for typical sets of multi-layered geotechnical profiles by numerical simulation based on forward modeling theory and field experiments for small-size model tests and real-scale tests in the field. In case of resistivity survey, 3-D finite element analyses and field tests were performed to investigate effects of adjacent concrete structures. These theoretical and experimental researches for surface-wave method and resistivity survey resulted in establishing physical criteria to cause interference of adjacent structures in site investigation at urban areas.

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Source Identification in 2-Dimensional Scattering Field Based on Inverse Problem (역문제를 이용한 2차원 산란장에서의 소스 추정)

  • Kim, Tae Yong;Lee, Hoon-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1262-1268
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    • 2014
  • Inverse problem is very interest in the sciences and engineering, in particular for modeling and monitoring applications. By applying inverse problem, it can be widely used to exploration of mineral resources, identification of underground cables and buried pipelines, and diagnostic imaging in medical area. In this paper, we firstly consider 2-dimensional EM scattering problem and present the FDTD method to estimate unknown source. In this case, non-linear CGM technique is used to investigate unknown sources corresponding to measured data obtained from forward problem in near field. The proposed technique for solving the inverse source problem presents a reasonable agreement and can be applied to investigate an internal source signal of embedded security module.

Nonlinear time-varying analysis algorithms for modeling the behavior of complex rigid long-span steel structures during construction processes

  • Tian, Li-Min;Hao, Ji-Ping
    • Steel and Composite Structures
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    • v.18 no.5
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    • pp.1197-1214
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    • 2015
  • There is a great difference in mechanical behavior between design model one-time loading and step-by-step construction process. This paper presents practical computational methods for simulating the structural behavior of long-span rigid steel structures during construction processes. It introduces the positioning principle of node rectification for installation which is especially suitable for rigid long-span steel structures. Novel improved nonlinear analytical methods, known as element birth and death of node rectification, are introduced based on several calculating methods, as well as a forward iteration of node rectification method. These methods proposed in this paper can solve the problem of element's 'floating' and can be easily incorporated in commercial finite element software. These proposed methods were eventually implemented in the computer simulation and analysis of the main stadium for the Universiade Sports Center during the construction process. The optimum construction scheme of the structure is determined by the improved algorithm and the computational results matched well with the measured values in the project, thus indicating that the novel nonlinear time-varying analysis approach is effective construction simulation of complex rigid long-span steel structures and provides useful reference for future design and construction.

Modeling the Properties of the PECVD Silicon Dioxide Films Using Polynomial Neural Networks

  • Han, Seung-Soo;Song, Kyung-Bin
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.195-200
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    • 1998
  • Since the neural network was introduced, significant progress has been made on data handling and learning algorithms. Currently, the most popular learning algorithm in neural network training is feed forward error back-propagation (FFEBP) algorithm. Aside from the success of the FFEBP algorithm, polynomial neural networks (PNN) learning has been proposed as a new learning method. The PNN learning is a self-organizing process designed to determine an appropriate set of Ivakhnenko polynomials that allow the activation of many neurons to achieve a desired state of activation that mimics a given set of sampled patterns. These neurons are interconnected in such a way that the knowledge is stored in Ivakhnenko coefficients. In this paper, the PNN model has been developed using the plasma enhanced chemical vapor deposition (PECVD) experimental data. To characterize the PECVD process using PNN, SiO$_2$films deposited under varying conditions were analyzed using fractional factorial experimental design with three center points. Parameters varied in these experiments included substrate temperature, pressure, RF power, silane flow rate and nitrous oxide flow rate. Approximately five microns of SiO$_2$were deposited on (100) silicon wafers in a Plasma-Therm 700 series PECVD system at 13.56 MHz.

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A Robust Adaptive Control of Dual Arm Robot with Eight-Joints Based on DSPs (DSPs 기반 8축 듀얼암 로봇의 견실적응제어)

  • Han, Sung-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.12
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    • pp.1220-1230
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    • 2006
  • In this paper, we propose a flew technique to the design and real-time control of an adaptive controller for robotic manipulator based on digital signal processors. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved Lyapunov second method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot manipulator with eight joints. joint space and cartesian space.

Complex Vector Modeling and Series Decoupling Current Control Strategy of High-Power L/LCL Type Grid-Connected Converter Under Low Switching Frequency

  • Wang, Yingjie;Jiao, Lanyi;Yang, Bo;Wang, Wenchao;Liu, Haiyuan
    • Journal of Power Electronics
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    • v.18 no.6
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    • pp.1879-1888
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    • 2018
  • With power level of grid-connected converters rising, the switching frequency of the switching devices is commonly greatly reduced to improve its power capacity. However, this results in serious couplings of the dq current components, which leads to degradation of the static and dynamic performances of grid-connected converters and fluctuations of the reactive power in dynamic processes. In this paper, complex vector models under low switching frequency are established for an L/LCL grid-connected converter, and the relationship between the switching frequency and the coupling degree is analyzed. In addition, a series decoupling current control strategy is put forward. It is shown that the proposed control strategy can eliminate the couplings, improve the performances and have good robustness to parameter variations through static and dynamic characteristics analyses and a sensitivity analysis. Experimental and simulation results also verify the correctness of the theoretical analyses and the superiority of the proposed control strategy.

BIM Platform Resource Management for BaaS(BIM as a Service) in Distributed Cloud Computing (BaaS(BIM as a Service)를 위한 분산 클라우드 기반의 BIM 플랫폼 리소스 관리 방법 연구)

  • Son, A-Young;Shin, Jae-Young;Moon, Hyoun-Seok
    • Journal of KIBIM
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    • v.10 no.3
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    • pp.43-53
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    • 2020
  • BIM-based Cloud platform gained popularity coupled with the convergence of Fourth Industrial Revolution technology. However, most of the previous work has not guaranteed sufficient efficiency to meet user requirements according to BIM service. Furthermore, the Cloud environment is only used as a server and it does not consider cloud characteristics. For the processing of High Capacity Data like BIM and using seamless BIM service, Resource management technology is required in the cloud environment. In this paper, to solve the problems, we propose a BIM platform for BaaS and an efficient resource allocation scheme. We also proved the efficiency of resource for the proposed scheme by using existing schemes. By doing this, the proposed scheme looks forward to accelerating the growth of the BaaS through improving the user experience and resource efficiency.