• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.3
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• pp.65-71
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• 1997

With the emergence of neural network, there is a revived interest in identification of nonlinear systems. So in this paper, to identify unknown nonlinear systems dynamically we propose DPNN(Dynamic Polynomial Neural Network) using GMDH (Group Method of Data Handling) algorithm. The dynamic system identification using GMDH consists of applying a set of inputloutput data to train the network by dynamically computing the necessary coeffici1:nt sets. Then, MRAC(Mode1 Reference Adaptive Control) is designed to control nonlinear systems using DPNN. In the result, we can see that the modelling and control using DPNN work well by computer simulation.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.289-293
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• 2009

본 논문은 공학교육과정에 기술사업화 교육이 본격적으로 도입되고 있는 최근 추세 하에 국내 공학교육 환경을 고려한 효과적인 기술사업화 교육시스템 모델을 제시하는데 그 목적이 있다. 이를 위해 첫째, 본 논문은 문헌연구를 통해 국내 공학교육 과정에서 전개되고 있는 기술사업화 교육의 주요 이슈들에 대해 진단하고 효과적인 기술사업화 교육시스템의 구축 방향을 분석하였다. 둘째, 본 논문은 문헌연구와 해외사례연구를 통해 공학교육과정에서 도입해야 하는 효과적인 기술사업화 교육시스템 모델을 정의하였다. 셋째, 본 논문은 국내 공학과정에 이미 도입된 기술사업화 교육시스템과 효과적인 기술사업화 교육 시스템 모델간의 비교연구를 통해 현재 국내 공학교육에서 이루어지고 있는 국내 기술사업화 교육시스템의 문제점을 진단하고 합리적인 개선방안을 제시하였다.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.177-183
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• 2012

Obtaining and applying information is considered as a critical task in the modern informationized society. Finding the one's necessary information and processing it into a detailed knowledge are becoming more priortized in the enormous amount of information. Data modelling is the process that does not only reflect the demands of the user but the one that also facilitates the user's comprehension of the model itself. Ultimately, data modelling fully supports the processes that are requisite for the implementation of a data base and minimizes the alternations of the model during the development of applications.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.6
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• pp.534-539
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• 2015

The DC overhead line voltage of an electric railway substation swings depending on the accelerating and regenerative-braking energy of trains, and it deteriorates the energy quality of the electric facility in the DC railway substation and restricts the powering and braking performance of subway trains. Recently, an energy storage system or a regenerative inverter has been introduced into railway traction substations to diminish both the variance of the overhead line voltage and the peak power consumption. In this study, the variance of the overhead line voltage in a DC railway substation is modelled by RC parallel circuits in each feeder, and the RC parameters are estimated using the recursive least mean square (RLMS) scheme. The forgetting factor values for the RLMS are selected using simulated annealing optimization, and the modelling scheme of the overhead line voltage variation is evaluated through raw data measured in a downtown railway substation.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1205-1207
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• 1996

The computed-torque method (CTM) shows good trajectory tracking performance in controlling robot manipulator if there is no disturbance or modelling errors. But with the increase of a payload or the disturbance of a manipulator, the tracking errors become large. So there have been many researchs to reduce the tracking error. In this paper, we propose a new control algorithm based on the CTM that decreases a tracking error by generating new reference trajectory to the controller. In this algorithm we used a fuzzy system based on the rule bases. For the numerical simulation, we used a 2-link robot manipulator. To simulate the disturbance due to a modelling uncertainty, we added errors to each elements of the inertia matrix and the nonlinear terms and assumed a payload to the end-effector. In the simulations of several cases, our method showed better trajectory tracking performance compared with the CTM.

• Nuclear Engineering and Technology
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• v.43 no.6
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• pp.489-498
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• 2011

UK National Nuclear Laboratory's (NNL's) version of the ENIGMA fuel performance code is described, including details of the development history, the system modelled, the key assumptions, the thermo-mechanical solution scheme, and the various incorporated models. The recent development of ENIGMA in the areas of whole core analysis and dry storage applications is then discussed. With respect to the former, the NEXUS code has been developed by NNL to automate whole core fuel performance modelling for an LWR core, using ENIGMA as the underlying fuel performance engine. NEXUS runs on NNL's GEMSTONE high performance computing cluster and utilises 3-D core power distribution data obtained from the output of Studsvik Scandpower's SIMULATE code. With respect to the latter, ENIGMA has been developed such that it can model the thermo-mechanical behaviour of a given LWR fuel rod during irradiation, pond cooling, drying, and dry storage - this involved: (a) incorporating an out-of-pile clad creep model for irradiated Zircaloy-4; (b) including the ability to simulate annealing out of the clad irradiation damage; (c) writing of additional post-irradiation output; (d) several other minor modifications to allow modelling of post-irradiation conditions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.123-134
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• 1995

After the introduction of ATM as a proper technology for B-ISDN, there have been many research efforts to realize ATM networks. But a computationally tractable modelling technique which reflects diverse characteristics of the ATM traffic accurately is not available yet. In this study, we try to establish an accurate but still convenient ATM traffic model. We first introduce the modelling technique for the voice traffic based on the fluid flow approximation. Then we present a traffic model for the mixed traffic from multiple video sources and voice sources. The video source model is based on the 3 state continuous time Markov chain. The accuracy of the model is demonstrated by some comparison results with respect to simulation.

• Geomechanics and Engineering
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• v.19 no.3
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• pp.229-240
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• 2019

The physical models are useful to understand the soil behaviour. Hence, these tools allow validating analytical theories and numerical data. This paper addresses the design, construction and implementation of a physical model able to simulate the soil liquefaction under different cyclic actions. The model was instrumented with a piezoelectric actuator and a set of transducers to measure the porewater pressures, displacements and accelerations of the system. The soil liquefaction was assessed in three different grain size particles of a natural sand by applying a sinusoidal signal, which incorporated three amplitudes and the fundamental frequencies of three different earthquakes occurred in Colombia. In addition, such frequencies were scaled in a micro shaking table device for 1, 50 and 80 g. Tests allowed identifying the liquefaction susceptibility at various frequency and displacement amplitude combinations. Experimental evidence validated that the liquefaction susceptibility is higher in the fine-grained sands than coarse-grained sands, and showed that the acceleration of the actuator controls the phenomena trigging in the model instead of the displacement amplitude.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.21-34
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• 2023

In order to analyze the effect of the cyclic lateral loading on the response of a pile-soil system, a full-scale single steel pile was subjected to one-way cyclic loading. The test pile was driven into a bi-layered soil consisting of a normally consolidated saturated clay overlying a silty sandy layer, the site being submerged by water up to one meter above the mudline in order to reproduce the conditions of an offshore pile foundation. The aim of this paper is to present the main results of interpretation of the cyclic lateral tests in terms of pile deflections, bending moment, and cyclic P-Y curves. From these latter an absolute secant reaction modulus E_AS,N was derived and a simple calculation model of the test single pile is proposed based on this modulus. Two applications of the proposed model are carried out, one with a 2D finite element modelling, and the second with a load transfer curves-based method.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.241-244
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• 2015

Within the building industry, building information modelling has been widely applied among different organizations, disciplines and project phases. In order to achieve coordination and synergy collaborative effort, it demands organized information flow and communication for effective implementation of project management through the construction process. Although many BIM researches provides solutions for project management, few efforts have involved the whole life-cycle process of project. In this article, BIM-based project management relying on a series of applications of BIM technology was introduced by coupling management requirement of a project with BIM. Through adopting BIM to the life-cycle management of the project and incorporating BIM applications to project management practice, we have developed a BIM-based project management approach that specialize in integrated BIM chain and interface-supporting system. At the end, the developing process of BIM-based project management approach is concluded.