• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3171-3181
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• 2000

With a remarkable growth and expansionof Internet, the security issues emerged from intrusions and attacks such as computer viruses, dental of servives and backings to destroy intormation have been considered as serious threats for Internet and the provate networks. To protect networks from those attacks, many nendors have developed various security systems such as firewalls, intrusion detection systems, and access control systems. However managing those systems individually requres too much work and high cost. Thus, integrated security managemanet and eatabliashment of consistent security policy for various security products has become more important. In this paper, we propose integrated security manabement system called WISMSF(Web based Integrated Security Management System for Fireswalls) to monitor and contro various kinds of firewalls WISMSF consists of three components-clients, integrated engine, and agents. It supports the transparent management functions of security products, easy ways of defining security policies, and simple expansion of managed ranges.

• Journal of Power Electronics
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• v.11 no.5
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• pp.759-766
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• 2011

This paper focuses on monitoring and predicting the short circuit faults of the rotor windings of large turbo-generator systems. For the purpose of increasing efficiency and decreasing maintenance cost, a method that combines the HHT (Hilbert Huang Transform) with a wavelet has been studied. This method is based on analyzing a classical Albright detecting coil. Due to the Empirical Mode Decomposition (EMD) and the Intrinsic Mode Functions (IMF) of the HHT the exact location of a short circuit of rotor windings may be given. However, a part of the useful information is eliminated by the unreasonable decomposing scale of the wavelet. Based on the thermodynamics modeling method, this study was illustrated with a 50MW turbo-generator system that is installed in Northern China. The analysis results, which have very good agreement with those of a previous study, show that the method of combining the HHT with a wavelet is an effective way to analyze and predict the short circuit faults of the rotor windings of large generators, such as supercritical turbo-generator systems and wind turbo-generator systems. This work can offer a useful reference for analyzing smart grids by improving the power quality of a distribution network that is supplied by a turbo-generator system.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.109-123
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• 2002

The purpose of this study construct water-facility Database and to develop its management system using GSIS. We used route system and event table that are data model in GSIS for the construction of water valves on water facility pipe. A water-facility management system using GSIS was developed and was actually applied for the city of Yosu and compared with conventional water-facility management systems in terms of workability, information searching cost, and database management efficiency. The system has also been compared with those of two other local governments in terms of functions, process time, and conveniences. The generalization of the work model for water-facility system was also attempted based on the data collected from three local governments and it was revised by the work model of the wide area water-facility system. The generalized work model in this study was compared with other two local governments' work models. The generalized work model will enable local governments to develop more efficient and economical water-facility management system by GSIS in future.

• International Journal of Automotive Technology
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• v.6 no.2
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• pp.107-117
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• 2005

A distributed hardware-in-the-loop simulation (HILS) platform is developed for designing an automotive engine control system. The HILS equipment consists of a widely used PC and commercial-off-the-shelf (COTS) I/O boards instead of a powerful computing system and custom-made I/O boards. The distributed structure of the HILS system supplements the lack of computing power. These features make the HILS equipment more cost-effective and flexible. The HILS uses an automatic code generation extension, REAL-TIME WORKSHOP$^{ (RTW$^{) of MATLAB$^{ tool-chain and RT-LAB$^{, which enables distributed simulation as well as the detection and generation of digital event between simulation time steps. The mean value engine model, which is used in control design phase, is imported into this HILS. The engine model is supplemented with some I/O subsystems and I/O boards to interface actual input and output signals in real-time. The I/O subsystems are designed to imitate real sensor signals with high fidelity as well as to convert the raw data of the I/O boards to the appropriate forms for proper interfaces. A lot of attention is paid to the generation of a precise crank/ earn signal which has the problem of quantization in a conventional fixed time step simulation. The detection of injection! command signal which occurs between simulation time steps are also successfully compensated. In order to prove the feasibility of the proposed environment, a simple PI controller for an air-to-fuel ratio (AFR) control is used. The proposed HILS environment and I/O systems are shown to be an efficient tool to develop various control functions and to validate the software and hardware of the engine control system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.257-263
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• 2013

In case of image observation equipments, CCTV for short distance visual field is usually installed and operated mostly as the means of crime-prevention. However, the extensive demand for monitoring problems in case of the increase in intelligent crimes and disasters has led to the necessity of the development of long-distance observation equipments embedded with Night View functions. In case of the Night View equipments, the relevant market is set up to be focused mostly on Thermal Observation Device(hereinafter, TOD), but some shortcomings such as the limitation of image visibility and excessive maintenance cost, etc. have actually caused the necessity of new long distance Night View equipment. Moreover there might follow lots of difficulties in long-distance visualization in the event that irregular reflection is generated by minute particles in the atmosphere such as fog, smog, and dust, etc. These factors are motivate the work presented in this study. Our study is aimed at the realization of Pulsed Laser Illuminator and newly proposed Range-Gated image acquisition technology. And also the implementation of Tracker for continuous trace of the objects of interest from the obtained sequence images.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1069-1078
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• 2018

Demand response (DR) programs give opportunity to consumers to manage their electricity bills. Besides, distribution system operator (DSO) is interested in using DR programs to obtain technical and economic benefits for distribution network. Since small consumers have difficulties to individually take part in the electricity market, an entity named demand response provider (DRP) has been recently defined to aggregate the DR of small consumers. However, implementing DR programs face challenges to fairly allocate benefits and payments between DRP and DSO. This paper presents a procedure for modeling the interaction between DRP and DSO based on a bilevel programming model. Both DSO and DRP behave from their own viewpoint with different objective functions. On the one hand, DRP bids the potential of DR programs, which are load shifting and load curtailment, to maximize its expected profit and on the other hand, DSO purchases electric power from either the electricity market or DRP to supply its consumers by minimizing its overall cost. In the proposed bilevel programming approach, the upper level problem represents the DRP decisions, while the lower level problem represents the DSO behavior. The obtained bilevel programming problem (BPP) is converted into a single level optimizing problem using its Karush-Kuhn-Tucker (KKT) optimality conditions. Furthermore, point estimate method (PEM) is employed to model the uncertainties of the power demands and the electricity market prices. The efficiency of the presented model is verified through the case studies and analysis of the obtained results.

• KIISE Transactions on Computing Practices
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• v.21 no.10
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• pp.645-650
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• 2015

Tester Interface Software (TIS) provides all software functions that are necessary for a testing device to perform the test process on a memory semiconductor package from the time the device is put into the test equipment until the device is discharged from the equipment. TIS should perform the same work over all types of equipment regardless of their tester models. However, TIS has been developed and managed independently of the tester models because there are various equipment and computer models that are used in the test process. Therefore, more maintenance, time and cost are required for development, which adversely affects the quality of the software, and the problem becomes more serious when the new tester model is introduced. In this paper, we propose the Cross-platform Tester Interface Software (CTIS) framework, which can be integrated and operated on heterogeneous equipment and OSs.

• The KIPS Transactions:PartA
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• v.14A no.3 s.107
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• pp.167-172
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• 2007

VM(Virtual Machine) can be considered as a software processor which interprets the machine code. Also, it is considered as a conceptional computer that consists of logical system configuration. But, the execution speed of VM system is much slower than that of a real processor system. So, it is very important to optimize the code for virtual machine to enhance the execution time. Especially the optimizer for a virtual machine code on embedded devices requires the highly efficient performance to the ordinary optimizer in the respect to the optimized ratio about cost. Fundamentally, functions and basic blocks which influence the execution time of virtual machine is found, and then an optimization for them nay get the high efficiency. In this paper, we designed and implemented the optimizer for the virtual(or abstract) machine code(VMC) using profiling. Firstly, we defined the profiling information which is necessary to the optimization of VMC. The information can be obtained from dynamically executing the machine code. And we implemented VMC optimizer using the profiling information. In our implementation, the VMC is SIL(Standard Intermediate Language) that is an intermediate code of EVM(Embedded Virtual Machine). Also, we tried a benchmark test for the VMC optimizer and obtained reasonable results.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.125-135
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• 1998

This study presents a design method for three-span continuous preflex composite girder bridges (3S-PCB) which imposes prestresses in the negative moment region by lifting or lowering interior supports and the design method is automated by a computer program which incorporates optimal design procedure. The objective function for the design of 3S-PCB minimizes the cost of construction materials and the constraint functions represent the limited dimensions of the design section and the allowable stress for each structural member as given in the specifications. Optimal design procedure used in this study is a modification of existing sequential unconstrained minimization technique (SUMT), a numerical analyses procedure for two-span continuous preflex composite bridges. The optimized design sections determined for each span length are compared with those of simple preflex composite beams (SPCB) and the optimal girder depth is determined by defining the relationship between girder depth and construction material costs.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.69-76
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• 2002

In conducting studies related to the national base networks, it is very important to construct a simulation network. This research provides an algorithm to construct the simulation network from the digital transportation map which is constructed based on the National Geographic Information System(NGIS). The algorithm consists of three functions(extraction of networks from transportation digital map, transform of the derived network into one suitable to transportation simulation model, and inspection of errors in the network). The direct derivation of a simulation network from GIS enables to enhance the reliability of an analysis related to a transportation facility investment as well as to reduce cost and time. In this research, Emme/2 which is generally accepted transportation planning fields is adapted for the target system. However, this algorithm will be extended to other simulation models such as Satong-Paldal which is the only transportation simulation model developed in Korea, and Tranplan in the near future.