• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.32-33
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• 2010

This paper describes a droop control method for the autonomous operation of DC distribution system using distributed generations and energy storage. The method suppress the circulating current, and each unit could be controlled autonomously without communication system. Detailed model of wind power generation, photo-voltaic generation, fuel-cell generation and battery was implemented with the user-defined model of PSCAD/EMTDC software that is coded with C-language. The simulation and experimental results confirms that the proposed DC distribution system make it feasible to provide power to the load stably and verify effectiveness of the proposed method.

• The KIPS Transactions:PartA
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• v.15A no.1
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• pp.35-44
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• 2008

It is important to manage access control for secure ubiquitous applications. In this paper, we present an access-control system for executing policy file which includes access control rules. We implemented Context-aware Access Control Manager(CACM) based on Java Context-Awareness Framework(JCAF) which provides infrastructure and API for creating context-aware applications. CACM controls accesses to method call based on the access control rules in the policy file. We also implemented a support tool to help programmers modify incorrect access control rules using static analysis information, and a simulator for simulating ubiquitous applications. We describe simulation results for several ubiquitous applications.

• The Journal of the Acoustical Society of Korea
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• v.6 no.1
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• pp.15-22
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• 1987

Fast Walsh-Hadamard Transform algorithm is discussed for secreting digital signals in ISDN. 16 characters are used for the password to control the coefficients of FWHT. And it gives above $3\times10^{38}$ codes. The FWHT module in presented in machine language. So it is applicable to compact cipher system or firmware system. Computer simulation showed secreting characteristics in printed data for N=128.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.48-56
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• 2012

This paper deals with power electronic converter education program using LabVIEW. LabVIEW is a graphic based programming language with easy debugging, which is suitable for education program that can be used to study and figure out the operation of power electronic converters. When LabVIEW is employed as a simulation program of the operation of power electronic converters, the resulting program has the advantage such that the effects of the change of control variables and circuit parameters on the various variables such as the output voltage and the inductor current etc can be directly displayed without any separate compiling procedure. This paper shows the design procedure and the characteristics of the power electronics education program implemented by LabVIEW focusing on DC-DC converter among power electronic converters.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.9
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• pp.671-683
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• 1989

A controller of interconnected power systems is investigated using an optimal multidimensional variable structure control. The switching hyperplane of the variable structure stabilizer is obtained by minimizing a quadratic performance index in continuous-time. A special feature of the optimal multidimensional variable structure stabilizer is that, when it is operated in the so-called sliding mode, the system response becomes insensitive to changes in the plant parameters. A digital simulation is performed by a digital computer using the Advanced Continuous Simulation Language (ACSL) package, which shows that the dynamic performance of the power system in response to mechanical torque changes is improved when optimal multidimensional variable sturcture stabilizers are employed.

• The KIPS Transactions:PartA
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• v.19A no.1
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• pp.23-34
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• 2012

This paper suggests that implementation of the Simulink execution module controls Simulink simulation and shows simulation results by applying Automata theory. This module is composed of three independent systems that the main program to accept user commands, the thread to control a simulation of Simulink model and the Simulink model to execute simulation. This paper designs each module and entire system by applying Automata theory, and implements it with C# and MATLAB language. And the Simulink execution module implemented will be verified through the experiment.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.719-728
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• 2022

The prediction of short-term traffic flow is the theoretical basis of intelligent transportation as well as the key technology in traffic flow induction systems. The research on short-term traffic flow prediction has showed the considerable social value. At present, the support vector regression (SVR) intelligent prediction model that is suitable for small samples has been applied in this domain. Aiming at parameter selection difficulty and prediction accuracy improvement, the artificial bee colony (ABC) is adopted in optimizing SVR parameters, which is referred to as the ABC-SVR algorithm in the paper. The simulation experiments are carried out by comparing the ABC-SVR algorithm with SVR algorithm, and the feasibility of the proposed ABC-SVR algorithm is verified by result analysis. Continuously, the simulation experiments are carried out by comparing the ABC-SVR algorithm with particle swarm optimization SVR (PSO-SVR) algorithm and genetic optimization SVR (GA-SVR) algorithm, and a better optimization effect has been attained by simulation experiments and verified by statistical test. Simultaneously, the simulation experiments are carried out by comparing the ABC-SVR algorithm and wavelet neural network time series (WNN-TS) algorithm, and the prediction accuracy of the proposed ABC-SVR algorithm is improved and satisfactory prediction effects have been obtained.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.2
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• pp.31-39
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• 1998

In this paper, we have presented a quantitative performance effect of CCP(Call Control Processor) when SAAL(Signalling ATM Adaptation Layer) function is distributed from CCP to SIMs(Subscriber Interface Modules) in an ATM switching system with distributed architecutre. For the performance analysis, SLAM II simulation language is used and subscriber signalling messageand inter-processor communication messages according to Q.2931 based local call processing procedure are taken into consideration in the proposed queuing network model. The results of simulation are compared with in case of processing SAAL function on CCP. It is observed that the processing utilization of CCP reach 24,000 BHCA and 25,700 BHCAwhen SAAL function load amounts to 10% and 20% of the processing time of the total message, respectively. These values shows that the processing utilization of CCP is alleviated about 7% in comparison with 2,000 BHCA in case that SAAL function is carried out on CCP. Consquently, it is shown that we have to consider seriously how to distribute the functions concerning call processing in a large cale ATM switching system architecture accomodating a number of SIMs.

• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.23-28
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• 1997

We discuss development of a simulator for automated manufacturing systems (AMSs) which have sophisticated automated material handling equipments and complicated work flows. The simulator is designed to satisfy the following requirements. A user should be able to easily configure or specify an AMS through a graphical user interface (GUI) and minimal data input. The user should be able to model diverse and complied control logic for automated material handling systems like automated guided vehicle (AGV) systems, robot workcell systems and conveyor systems as well as complicated job flow program. Real time animation is desired. Finally, the simulator should be easily maintained and extended. To satisfy the requirements, we use an object-oriented paradigm for modeling, designing, and programming of the simulator. We use an object-oriented modeling framework to design the modeling elements library, and take the process interaction approach for scheduling processes and events. To model a user-defined diverse control logic, we also develop a script language and its interpreter. We explain design and implementation strategies. We implement the simulator using Visual C++ 4.2 and Open GL on Windows NT and the Windows95. Some modeling examples will be demonstrated.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.474-477
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• 2005

The Industrial development and the Increase in population have brought out a rapid increase of wastewater discharge. To deal with this matter, much estimate has been spend on construction and management of a large scale sewage treatment plant. Although every effort has been carried out, river water quality has no significantly improved. Especially. the aggravation of the water quality in dry season is brought out a serious social problem. The purpose of this study Is the development of an optimal water quality management technique considering the efficient control of the multiple pollutant load associated with the total pollutant load control. A GUI(Graphical User Interface) system named 'QL2-XP' model is developed by object-oriencted language for the user convenience and practical usage. Suggested GUI system consist of hydraulic analysis. water quality analysis, optimized model calibration processes, and postprocessing the simulation results.