Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Transactions of The Korean Institute of Electrical Engineers
Journal Basic Information
Journal DOI :
The Korean Institute of Electrical Engineers
Editor in Chief :
Volume & Issues
Volume 56, Issue 12 - Dec 2007
Volume 56, Issue 11 - Nov 2007
Volume 56, Issue 10 - Oct 2007
Volume 56, Issue 9 - Sep 2007
Volume 56, Issue 8 - Aug 2007
Volume 56, Issue 7 - Jul 2007
Volume 56, Issue 6 - Jun 2007
Volume 56, Issue 5 - May 2007
Volume 56, Issue 4 - Apr 2007
Volume 56, Issue 3 - Mar 2007
Volume 56, Issue 2 - Feb 2007
Volume 56, Issue 1 - Jan 2007
Selecting the target year
Application of Parallel PSO Algorithm based on PC Cluster System for Solving Optimal Power Flow Problem
Kim, Jong-Yul ; Moon, Kyoung-Jun ; Lee, Haw-Seok ; Park, June-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1699~1708
The optimal power flow(OPF) problem was introduced by Carpentier in 1962 as a network constrained economic dispatch problem. Since then, the OPF problem has been intensively studied and widely used in power system operation and planning. In these days, OPF is becoming more and more important in the deregulation environment of power pool and there is an urgent need of faster solution technique for on-line application. To solve OPF problem, many heuristic optimization methods have been developed, such as Genetic Algorithm(GA), Evolutionary Programming(EP), Evolution Strategies(ES), and Particle Swarm Optimization(PSO). Especially, PSO algorithm is a newly proposed population based heuristic optimization algorithm which was inspired by the social behaviors of animals. However, population based heuristic optimization methods require higher computing time to find optimal point. This shortcoming is overcome by a straightforward parallel processing of PSO algorithm. The developed parallel PSO algorithm is implemented on a PC cluster system with 6 Intel Pentium IV 2GHz processors. The proposed approach has been tested on the IEEE 30-bus system. The results showed that computing time of parallelized PSO algorithm can be reduced by parallel processing without losing the quality of solution.
Compensating Algorithm for the Secondary Current of a Measurement CT Considering the Hysteresis Characteristics of the Core
Kang, Yong-Cheol ; Zheng, Tai-Ying ; Jang, Sung-Il ; Kim, Yong-Gyun ; So, Soon-Hong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1709~1714
This paper proposes a compensating algorithm for the secondary current of the measurement current transformer (CT) that removes the effects of the hysteresis characteristics of the iron-core. The exciting current resulting from the hysteresis characteristics of the core causes an error between the primary current and the secondary current of the measurement CT. The exciting current can be decomposed into the magnetizing current and the core loss current. The core loss current is obtained from the measured secondary current and the core loss resistance. The core flux linkage is calculated by integrating the measured secondary current, and then inserted into the flux-magnetizing current curve to obtain the magnetizing current. The exciting current at every sampling interval is obtained by summing the core-loss and magnetizing currents and then added to the measured current to obtain the correct current. The performance of the proposed algorithm is validated under various conditions using EMTP generated data. The results indicate that the proposed algorithm can improve the accuracy of the measurement CT significantly, and thus reduce the size and the cost of the measurement CT.
The Affections of System Stability on Replacing the Synchronous Condenser in Jeju Island
Chang, Byung-Hoon ; Yoon, Jong-Su ; Han, Jeong-Yeol ; Shim, Jeong-Woon ; Kang, Sang-Gyun ; Lee, Byong-Joon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1715~1720
The CSC-based HVDC system links the Jeju system to the mainland system. Because CSC-based HVDC is installed in Jeju, the reactive power is needed to transfer active power through the HVDC. In order to supply reactive power, switched capacitors and synchronous condensers are installed in Jeju system. The deterioration of established synchronous condensers, however, causes a reactive power supply capability decline and high maintenance cost. It brings about the instability of Jeju system and the incremental of maintenance and repair costs. In the future the installation of wind generators and additional HVDC system would aggravate the stability of Jeju system. Therefore, it needs to consider a countermeasure against above problems. In this paper, Analysis of several contingencies of Jeju system was peformed, and some contingencies caused voltage-reactive power problem was known. CPF method was introduced in order to make countermeasures to replace the synchronous condensers and to solve the voltage-reactive power problem. The location and capacity of reactive power sources were also decided. It could guarantee medium and long term stability of Jeju system.
A New Dispatch Scheduling Algorithm Applicable to Interconnected Regional Systems with Distributed Inter-temporal Optimal Power Flow
Chung, Koo-Hyung ; Kang, Dong-Joo ; Kim, Bal-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1721~1730
SThis paper proposes a new dispatch scheduling algorithm in interconnected regional system operations. The dispatch scheduling formulated as mixed integer non-linear programming (MINLP) problem can efficiently be computed by generalized Benders decomposition (GBD) algorithm. GBD guarantees adequate computation speed and solution convergency since it decomposes a primal problem into a master problem and subproblems for simplicity. In addition, the inter-temporal optimal power flow (OPF) subproblem of the dispatch scheduling problem is comprised of various variables and constraints considering time-continuity and it makes the inter-temporal OPF complex due to increased dimensions of the optimization problem. In this paper, regional decomposition technique based on auxiliary problem principle (APP) algorithm is introduced to obtain efficient inter-temporal OPF solution through the parallel implementation. In addition, it can find the most economic dispatch schedule incorporating power transaction without private information open. Therefore, it can be expanded as an efficient dispatch scheduling model for interconnected system operation.
Generation Investment Model Development and Behavior Analysis using System Dynamics Approach
Kim, Hyun-Shil ; Yoon, Yong-Beum ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1731~1737
The Korea electricity wholesale market is operated under the cost-based-pool system and the government regulation to the new generation capacities in order to insure the resource adequacy. The goal of government's regulation is the electricity market stability by attracting proper generation investment while keeping the reliability of system. Generation companies must mandatory observe that government plan by now. But if the restructuring is to be complete, generation companies should not bear any obligation to invest unless their profitability is guaranteed. Namely the investors' behavior will be affected by the market prices. In this paper, the system dynamics model for Korea wholesale electricity market to examine whether competitive market can help to stabilize is developed and analyzes the investors behavior. The simulation results show that market controlled by government will be operated stable without resulting in price spike but there is no lower price because of maintaining the reasonable reserve margin. However, if the competition is introduced and the new investment is determined by the investor's decision without government intervention, the benefits from lower wholesale price are expected. Nevertheless, the volatility in the wholesale market increases, which increases the investment risks.
A Study on the Strategic Competition Model of Pumped Storage Plant
Lee, Kwang-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1738~1743
This paper addresses the bidding strategies of a pumped-storage hydro plant in an electricity market. Competitive bidding of pumping and generating of a pumped-storage plant is formulated in a game theoretic problem in accordance with the three different ownership of scheduling; Market Operator(MO), generating company(Genco), and combined type of MO and Genco. Optimal conditions for Nash Equilibrium are derived in the form of market prices during the scheduling periods. Simulation results show the different ownership models produce different schedules of pumping and generating, which correspond to the objective of the scheduling owner of a pumped-storage hydro plant.
Performance Test of an Integrated Electronic Protection Device Based Photovoltaic Inverter
Kim, Eung-Sang ; Kim, Seul-Ki ; Jeon, Jin-Hong ; Ahn, Jong-Bo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1744~1750
This paper addresses grid interconnection tests of a 3kW transformer-less photovoltaic (PV) inverter to verify the effectiveness of the PV inverter and promote its wide use. The 3kW transformer-less PV inverter, which was equipped with intelligent protection and control system, was manufactured. A hardware test bed was constructed for performance tests of the PV inverter. Control performance and grid protection tests were carried out using the test bed. Test results verify the performance of the power control and grid protection functions of the developed transformer-less PV inverter.
A High Performance Pressure Control of SR Type Hydraulic Pump System using Direct Instantaneous Torque Control Method
Ahn, Jin-Woo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1751~1756
This paper presents a high performance pressure control scheme for SR(Switched Reluctance) type hydraulic oil pump using DITC(Direct Instantaneous Torque Control). SR drive has a good feature for pump applications due to a high efficiency, high speed and high torque characteristics. But, SR drive has high torque ripple in commutation region. So, the pump pressure variation is high in the region. In order to reduce the pressure variation, DITC combined with pressure control scheme is presented in this paper. A simple PI controller with flow and pressure limit, generates a reference torque to keep the constant actual pump pressure. The direct torque controller of SR drive generates inverter switching signals according to a control rule and a torque estimator. Computer simulation and experiemtal results show the validation of the proposed control scheme.
Optimal Design of Power Loss for 3 Phase Voltage Source Inverter by using Thermal Management
Cho, S.E. ; Park, S.J. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1757~1762
Recently, the demand for the low cost power conversion equipment is rapidly increased. To develop this three phase voltage source inverter, optimum power conversion equipment to system is designed. The optimum operation method to minimize the power loss also satisfy the life time of the power electronics that is request in the present industry. In this paper, the efficient operating method to change of the acceleration, jerk, and switching frequency in the interval of acceleration is selected to optimize the power loss and life time of the power electronics by using the elevator model. So, we proposed the method that 50[A] rating power electronics is adopted in 9[kW] load.
A Study on Performance Improvement of Hybrid Energy Storage System for Mild HEV
Lee, Back-Haeng ; Shin, Dong-Hyun ; Kim, Hee-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1763~1769
To improve the cycle-life and efficiency of an energy storage system for HEV, a dynamic control system consisted of a switch between a battery and an ultracapacitor module is proposed, which is appropriate for mild hybrid vehicle with 42V power net. The switch can be controlled based on the status of the battery and the ultracapacitor module, and a control algorithm that could largely decrease the number of high charging current peak is also implemented. Therefore the cycle life of the battery can be improved such that it is suitable for a mild hybrid vehicle with frequent engine start-stop and regenerative-braking. Also, by maximizing the use of the ultracapacitor, the system efficiency during high current charging and discharging operation is improved. Finally, this system has the effects that improves the efficiency of energy storage system and reduces the fuel consumption of a vehicle. To verify the validity of the proposed system, this paper presented cycles test results of different energy storage systems: a simple VRLA battery, hybrid energy Pack (HEP, a VRLA battery in Parallel with Ultracapacitor) and a HEP with a switch that controlled by energy management system (EMS). From the experimental result, it was proved the effectiveness of the algorithm.
An Experimental Evaluation of the Vehicle Control Algorithm in Personal Rapid Transit System
Lee, Jun-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1770~1774
In this paper we deal with a design of the evaluation system to assess the vehicle operational control algorithm for Personal Rapid Transit(PRT) system. PRT system is different from the conventional rail traffic system in such that the station is off-line so as to guarantee a very short headway. In this study we propose an evaluation system to assess the performance of the proposed vehicle control algorithm. The evaluation system is composed of virtual vehicles, central control system, virtual wayside facilities, monitoring equipments. The virtual vehicles are made up by the laptop computers and the central control system employs Power PC process of Motorola Inc. The wayside facilities are implemented by employing the PXI module of the National Instruments Corporation. In order to test the proposed evaluation system a test algorithm is used, which has been simulated in the combined simulation system between Labview Simulation Interface Toolkit and Matlab/Simulink.
Rotational loss assessment of flywheel energy storage system by Motor/Generator core
Lee, Jeong-Phil ; Han, Young-Hee ; Jung, Se-Yong ; Han, Sang-Chul ; Jeong, Nyeon-Ho ; Sung, Tae-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1775~1781
In this paper, the rotational loss of the superconductor flywheel energy storage system (SFES) by motor/generator stator core was assessed. To do this, the vertical axial type SFES with journal type superconductor bearing was manufactured. To quantitatively assess the rotational loss by the stator core, the rotational losses by superconductor bearing and the degree of a vacuum were measured. In case of variation of the inner radius and outer radius of the stator core, the rotational losses were measured. From the experimental results, It is confirmed that the rotational loss can be reduced by means of the optimal stator core design.
The Effect of Different Substrate Temperature on the Electrical Properties of Al-doped ZnO Thin Films
Kim, Bong-Seok ; Kim, Eung-Kwon ; Lee, Kyu-Il ; Oh, Su-Young ; Song, Joon-Tae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1782~1785
In this paper, the effect of substrate temperature on structural, electrical and optical properties of aluminium-doped zinc oxide (AZO) films were investigated. AZO thin films were prepared on glass substrate by pulsed DC magnetron sputtering technique. The properties of AZO were measured by using XRD, AFM, UV spectrophotometer, and hall effect measurement system. The resistivity of AZO films was improved under the condition of high substrate temperature. The resistivity decreased from
as a result of high substrate temperature and the average transmittances in visible range were above 80%.
Electrical Properties of Pt/SCT/Pt Thin Film Structure
Kim, Jin-Sa ; Shin, Cheol-Gi ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1786~1790
thin films are deposited on Pt-coated electrode (
) using RF sputtering method at various deposition temperature. The dielectric constant of SCT thin films were increased with the increase of deposition temperature, and changed almost linearly in temperature ranges of
. Also, SCT thin films was observed the phenomena of dielectric relaxation with the increase of frequency, and the relaxation frequency was observed above 200[kHz]. V-I characteristics of SCT thin films show the increasing leakage current with the increases of deposition temperature. The conduction mechanism of the SCT thin films observed in the temperature range of
can be divided into three characteristic regions with different mechanism by the increasing current. The region 1 below 0.8[MV/cm] shows the ohmic conduction. The region 2 can be explained by the Child's law, and the region 3 is dominated by the tunneling effect.
Corona Cage Simulation on Environmental Characteristics Caused by the Ion flow of Candidated Conductor Bundles for HVDC Overhead Transmission
Ju, Mun-No ; Yang, Kwang-Ho ; Lee, Dong-Il ; Shin, Koo-Yong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1791~1795
Small ions generated at conductor corona sources remain in the atmosphere until they recombine with ions of opposite polarity, attach to aerosols, or make contact with an object. Ion current density is major factor to design conductor configuration of DC overhead transmission line. Several techniques have been used to measure the ion current of HVDC overhead transmission line. In this study, the ion current density was measured by a plate electrode made of a metal flat board at DC corona cage. The sensitivity of the plate electrode is
. To obtain an useful database on corona discharge, it is necessary to do corona test on several kinds of conductor bundles. Therefore, a number of experiments were conducted on several kinds of conductor bundles. To reliably analyze ion effects, corona cage test data were obtained over a long period of time under various weather conditions and expressed as a statistical distribution. Ion current density distribution in foul weather shows a significant increase in levels over the corresponding fair weather. Based on this results, we evaluated the environmental characteristic caused by ion flow of three candidated conductor bundles.
Analyses of Earth Surface Potentials Depending on Soil Structures
Lee, Bok-Hee ; Baek, Young-Hwan ; Jung, Hyun-Wook ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1796~1801
This paper presents electric potential rise on the surface of the earth due to ground currents. It is the aim of this paper to propose fundamental data relevant to the earth surface potentials depending on the soil structures. The earth potential rise, touch and step voltages in the immediate vicinity of the ground rod of a distribution pole were measured and analyzed. The results described in this paper are based on laboratory measurements which were intended to simulate conditions existing in actual installations. As a result, the earth surface potential rise, touch and step voltages strongly depend on the soil structure. The highest earth surface potential occurred in the vicinity of the top of ground rod. When the ground rod was installed in the distance range of
from distribution pole, the highest touch voltages appeared near the place of 1 m on the straight line connecting the distribution pole to ground rod.
The Development of Non-thermal Micro Plasma Source Under Atmospheric Pressure by Means of Submicrosecond Pulse Voltage Waveforms
Choi, Joon-Young ; Lee, Ho-Jun ; Kim, Dong-Hyun ; Lee, Hae-June ; Park, Chung-Hoo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1802~1806
Nowadays, many configurations and applications of small atmospheric plasma source have been investigated with growing interest, as it provides the bacteria inactivation, the surface modification and removal of unwanted small regions, and so on. In this paper, the non-thermal micro plasma source under atmospheric pressure by means of submicrosecond pulse voltage waveforms is suggested. Plasma operates in helium is appears as a small (sub-mm) glow at the tip of a plasma gun. Electrical measurements show that the plasma source operates at low voltage (about 500V) and the power consumption is about 1W at 25kHz. Moreover, the emission spectrum shows the relatively higher emission intensity of oxygen particles than those of helium and nitrogen.
Fabrication of the Capacitance Controlled Active Integrated Phased Array Antenna and It's Scanning Characteristics
Choi, Young-Kyu ; Nam, Beong-Geun ; Shin, Sang-Yeol ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1807~1813
This paper deals with extending the variable natural oscillation frequency range of an active integrated FET oscillator. In this paper, we conform experimentally that the variable range of the natural oscillation frequency is expanded about three times in the oscillator controlled by the varactor diode. When the frequency difference is given to the oscillators in the two element antenna system, phase difference appeared between the oscillators. The 2-, 3-, 4-, 5-element patch antenna arrays are composed for the beam scanning experiments. All the above patch antennas show good phased array characteristics. The range of the scanning angle is about
, and the radiation power is gradually increased from
. The radiation patterns we sharpened as the number of elements is increased.
Design of a Microwave Active Resonator Using Defected Ground Structure with Islands (DGSI)
Hwang, Mun-Su ; Oh, Seong-Min ; Ahn, Dal ; Lim, Jong-Sik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1814~1819
A new active resonator using defected ground structure with islands (DGSI) is proposed. The proposed resonator is composed of the conventional microstrip line with DGSI and negative resistance of active devices. The negative resistance part is realized by field effect transistor (FET) series feedback circuits. The characteristic of the proposed resonator with DGSI is improved by combining the negative resistance part with the parallel microstrip line structure with islands, where the electric field is formed the most strongly. The measured improvement of the proposed active resonator with DGSI are 4.55dB and 0.32dB in S21 and S22, respectively, at the resonant frequency whorl it is compared to the existing passive resonator having DGSI only.
Polarization-controlled Interleaved Signal Gating Fiber Device
Lee, Yong-Wook ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1820~1822
In this paper we fabricated a fiber device composed of cascaded long-period fiber gratings between which a birefringent erbium-doped fiber was inserted and proposed its application as a polarization-controlled interleaved signal gating fiber device. Because the core and cladding modes of the fabricated fiber device have polarization-dependent phase difference due to the birefringence of the erbium-doped fiber, its interference spectrum can be modulated by varying the input polarization.
Fiber-optic Ccurrent Sensor Using a Long-period Fiber Grating Inscribed on a High Birefringent Fiber
Lee, Yong-Wook ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1823~1825
Based on Faraday effect, the variation of current flowing through the conductor can be encoded as that of azimuth angle of light polarization propagating through the fiber coil wound onto the conductor. The amount of current can be obtained by measuring the variation of the light intensity transformed from that of the azimuth angle through a polarization analyzer. In this paper we propose a fiber-optic current sensor system that employs a fiber polarization analyzer as a sensor interrogation device. The fiber polarization analyzer was prepared by inscribing a long-period fiber grating on a high birefringent fiber. At the fixed wavelength of 1522.5 nm, the fabricated fiber device has the polarization extinction ratio of more than 25 dB. The measurement of large current up to 600 Arms was accomplished based on a simple fiber interrogation device and the measurement output of the sensor system showed a good linearity.
A Study of Automatic Multi-Target Detection and Tracking Algorithm using Highest Probability Data Association in a Cluttered Environment
Kim, Da-Soul ; Song, Taek-Lyul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1826~1835
In this paper, we present a new approach for automatic detection and tracking for multiple targets. We combine a highest probability data association(HPDA) algorithm for target detection with a particle filter for multiple target tracking. The proposed approach evaluates the probabilities of one-to-one assignments of measurement-to-track and the measurement with the highest probability is selected to be target- originated, and the measurement is used for probabilistic weight update of particle filtering. The performance of the proposed algorithm for target tracking in clutter is compared with the existing clustering algorithm and the sequential monte carlo method for probability hypothesis density(SMC PHD) algorithm for multi-target detection and tracking. Computer simulation studies demonstrate that the HPDA algorithm is robust in performing automatic detection and tracking for multiple targets even though the environment is hostile in terms of high clutter density and low target detection probability.
NvBAT Treatment for AIDS Patients: The Superiority of PI Over RTI
Jo, Nam-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1836~1843
In this paper, we study the NvBAT treatment for AIDS patients that is combined with PI rather than RTI, while the Previous results have been focused on the NvBAT in conjuction with RTI. To this end, we obtain a bifurcation diagram which shows a change in the equilibrium points, and in their stability properties as the PI drug effect is varied. Based on the bifurcation diagram, we show that the NvBAT can be combined with drug PI for the treatment of AIDS patients. Various computer simulation results are included, which show the superiority of the NvBAT with PI over that with RTI. Accordition to simulation result, the NvBAT combined with PI is able to keep virus load level lower than that combined with RTI, which is crucial to avoid the emergence of drug-resistant mutants. Moreover, it is shown that, for some AIDS patients, NvBAT with RTI cannot make patients into long term non-progressor, while NvBAT with PI can.
Compensation of Unknown Time-Varying Sinusoidal Disturbances in Nonlinear Systems using Disturbance Accommodation Technique
Chwa, Dong-Kyoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1844~1851
This paper presents methods for the compensation of sinusoidal disturbances with unknown amplitude, phase, and time-varying frequency in nonlinear systems. In the previous disturbance accommodation methods, the sinusoidal disturbance with unknown time-invariant frequency was considered. In the proposed method, the disturbance with unknown time-varying frequency is compensated. As for the control structure, two control inputs are designed separately in such a way that one of them is designed for the nonlinear system control without considering the disturbance, and the other one uses the disturbance estimate obtained from the disturbance accommodating observer. The stability analysis is done considering the disturbance estimation error and the numerical simulation demonstrates the proposed approach.
Development of Reliability Evaluation System for I&C System Upgrade
Chung, Hak-Young ; Kang, Hyeon-Tae ; Sung, Chan-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1852~1858
To Increase availability and to enhance the safety, the modernization of Instrumentation & Control (I&C) systems is considered. The extended use of the digital technology lets nuclear power plants(NPPs) to replace their old analog systems with some proven digital systems. To adapt digital equipment to plants effectively and systematically, however, there must be an essential prerequisite, which is to evaluate current I&C equipment. This paper shows a practical methodology to evaluate the current status and reliability of I&C systems of NPPs using Reliability Evaluation System(RES) before performing upgrades or replacements for systems. The proposed method was applied to KORI Unit 2. The proposed method shows the current status of operating I&C systems effectively for upgrading I&C systems.
Robust Restoration of Barcode Signals
Lee, Han-A ; Lee, Jeong-Tae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1859~1864
Existing barcode signal restoration algorithms are not robust to unmodeled outliers that may exist in scanned barcode images due to scratches, dirts, etc. In this paper, we describe a robust barcode signal restoration algorithm that uses the hybrid
norm as a similarity measure. To optimze the similarity measure, we propose a modified iterative reweighted least squares algorithm based on the one step minimization of a quadratic surrogate function. In the simulations and experiments with barcode images, the proposed method showed better robustness than the conventional MSE based method. In addition, the proposed method converged quickly during optimization process.
Detection of Junctions via Accumulation of Connectivity-based Weight in Image Space : Applications for Locating 2D Barcode
Kim, Jeong-Tae ; Song, Jin-Young ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1865~1867
We propse a novel corner detection algorithm for locating 2D Data Matrix barcode in an image. The proposed method accumulates weight for each cross point defined by every combination of edge points in the image, and detects the corner point of the barcode L-pattern by determining the location of the highest accumulated weight. By designing the weight considering the connectivity of two lines around the cross point, we were able to detect the corner of L-pattern even for the cases that the lines of L-patterns are short. In the experiments, the proposed method showed improved performance compared with the conventional Hough transform based method in terms of detectability and computation time.
Optimal Mode Prediction-based Fast Mode Decision Algorithm for H.264-based Mobile Devices
Cho, Yong-Su ; Kim, Yong-Goo ; Choi, Yung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 10, 2007, Pages 1868~1871
This paper proposes a novel scheme to significantly reduce mode decision time by predicting optimal mode candidates. Unlike previous fast mode decision algorithms computing RDcost in a pre-defined mode order, the proposed scheme predicts optimal mode candidates and calculates their RDcosts first, increasing the possibility to satisfy early-exit conditions sooner, resulting in fast mode decision. This H.264 mode decision time reduction enables small computing power mobile devices to handle H.264 encoding effectively. Extensive simulations show that, when compared with JM10.2, AMD and LCIMS, the proposed scheme boosts H.264 encoding speed by up to 575% with a reasonable image quality degradation.