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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of The Korean Institute of Electrical Engineers
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The Korean Institute of Electrical Engineers
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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
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On-line Tests of on the Yang-Yang Pumped Storage Plant for the Reactive Power Limits and the OEL Dynamics
Kim, Dong-Joon ; Moon, Young-Hwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1343~1350
This paper describes the tests on the reactive power output limit and the Over-Excitation Limiter (OEL) dynamics of a generation unit. The suggested test methods on reactive limit can identify the allowable maximum/minimum reactive power at 100% rated MW in the steady-state unit operation condition. The on-line OEL test method can identify the time characteristics of OEL with the generation output at 50% of the rated MW. These methods are validated by applying to four Yang-Yang pumped storage units with 282 rated MVA each.
A Study on Power Quality Diagnosis System using Neural NetWorks
Kim, Jin-Su ; Kim, Young-Il ; Kim, Kwang-Soon ; Park, Gi-Ju ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1351~1359
In this paper, we have studied the power quality(PQ) diagnosis system with the two methods for PQ diagnosis. One to Apply a regulation value in compliance with mathematics calculation, and the other Automatic identification using Neural network algorithm. Neural network algorithm is used for an automatic diagnosis of the PQ. The regulation proposed by IEEE 1159 Working group is applied for the precision of the diagnosis. In order to divide accurate segmentation, the algorithm for a computer training used the back propagation out of several neural network algorithms. We have configured the proto-type sample by using Labview and a programmed Neural Networks Algorithm using with C. And arbitrary electric Signal generated by OMICRON Company's CMC 256-6 for an efficiency test.
A Study of Reconfiguration for Load Balancing in Distribution Power System
Seo, Gyu-Seok ; Baek, Young-Sik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1360~1366
In this paper, the load balancing which is one of the distribution power system's operation purposes was studied. Reconfiguration of Distribution power system presents that the configuration is changed by changing the switch on/off status which exists in the system according to the mentioned purpose. Through this method, the load of distribution power system is shown to be balanced. As a characteristic of complicated distribution power system, system is designed by being applied by OOP(Object Oriented Programming) method which connected more flexibly than existing Procedural Programming method, and the process of calculating the distflow and the loss of configurated system is shown. In addition, this paper suggests more efficient method compared by the results of reconfiguration on the purpose of the loss minimization and by the result of distribution power system reconfiguration on the purpose of load balancing. Moreover, it searches for the method to approach the global optimal solution more quickly.
A Study on Coherency Aggregation Method Using Relation Index of State Variables in the Power System
Lee, Byung-Ha ; Baek, Jung-Myoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1367~1372
The modem large electric power system has made power system analysis much more complex and difficult. For effective analysis of the power system, model reduction and aggregation is required. In this paper, a new relation index to identify the coherency among the generators is presented and also a new aggregation method is presented to aggregate the coherent generators in the large scale power system while matching the power flow. In order to demonstrate the effects of this aggregation method, it is applied to the IEEE 39 bus test power system and to the 2006 summer power system of Korea Electric Power Corporation, and the simulation results are compared with those of the original system.
A Windows-based Software for Education and Training of Transmission Network Charge
Kim, Hyun-Houng ; Cho, Ki-Seon ; Jeong, Yun-Won ; Park, Jong-Bae ; Shin, Joong-Rin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1373~1381
This paper presents a graphical windows-based software for the education and training of transmission network charge. The motivation for the development of the simulator is to provide students with a simple and useable tool for gaining an intuitive feel for transmission network charge. The developed simulator consists of the main module (MMI, GUI), the power flow module (PF), the power flow tracing module (PFT), and usage cost DB module (UCD). Each module has a separate graphical and interactive interfacing window. The developed simulator provides with two power system analysis methods (i.e., DC-PF and Modified DC-PF) and supports the PSS/E input data format to load input data of power system. Also, power flow tracing can be calculate using four methods such as "Felix Wu", "Modified Felix Wu", "DCLF ICRP", and "Reverse MW mile". Results of calculation for transmission usage cost are displayed and compared on the window through the table and/or chart. Therefore, the developed simulator can be utilize as a useful tool for effective education and training of transmission network charge.
An Application of a Binary PSO Algorithm to the Generator Maintenance Scheduling Problem
Park, Young-Soo ; Kim, Jin-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1382~1389
This paper presents a new approach for solving the problem of maintenance scheduling of generating units using a binary particle swarm optimization (BPSO). In this paper, we find the optimal solution of the maintenance scheduling of generating units within a specific time horizon using a binary particle swarm optimization algorithm, which is the discrete version of a conventional particle swarm optimization. It is shown that the BPSO method proposed in this paper is effective in obtaining feasible solutions in the maintenance scheduling of generating unit. IEEE reliability test systems(1996) including 32-generators are selected as a sample system for the application of the proposed algorithm. From the result, we can conclude that the BPSO can find the optimal solution of the maintenance scheduling of the generating unit with the desirable degree of accuracy and computation time, compared to other heuristic search algorithm such as genetic algorithms. It is also envisaged that BPSO can be easily implemented for similar optimizations and scheduling problems in power system problems to obtain better solutions and improve convergence performance.
Optimal Design for Starting -Torque of Line-Start Permanent Magnet Synchronous Motors
Kim, Byong-Kuk ; Moon, Ji-Woo ; Kim, Mi-Jung ; Lee, Byung-Jun ; Cho, Yun-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1390~1396
The line-start permanent magnet synchronous motor has a high efficiency and an advantage in constant speed operation regardless of the effect of load variation. However, it is difficult to predict the performance of characteristics accurately, because of the unbalanced starting torque with the initial starting position of the rotor and the generation of a break torque. In this paper the dynamic characteristics of the line-start permanent magnet synchronous motor are described and compared with those of the squirrel-cage induction motor through the simulation to find the characteristics of the permanent magnets and the rotor bars in the line-start permanent magnet synchronous motor. Finally this paper gives the comparison between the simulation results and the experimental results.
A New Method for Resistive Leakage Current Measurement
Ham, Seung-Jin ; Hahn, Song-Yop ; Koh, Chang-Seop ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1397~1404
It is important to measure the resistive component separately from the total leakage current at power distribution line. It is because electric disasters such as electric shock and fire are caused mainly by the resistive component of the total leakage current. In this paper, a new theory for measuring the resistive component separately from the total leakage current is suggested, and is embodied to an actual circuit using operational amplifiers, analog switch and R-C low pass filter. Through experiments for various cases containing both the resistive and capacitive leakage currents, the suggested algorithm is confirmed to be able to measure the resistive leakage current within 4.1% of error even when the capacitive leakage current is much bigger than the resistive one. The suggested method is expected to lower the total cost because it can be realized using simple and cheap devices, and implies the measuring time can be possibly reduced because the resistive leakage current is computed exactly from the signals during only a half period of power voltage.
A Sensorless Speed Control of an Interior Permanent Magnet Synchronous Motor Based on a Fuzzy Speed Compensator
Kang, Hyoung-Seok ; Kim, Young-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1405~1411
In this paper, a new speed sensorless control based on a fuzzy compensator are proposed for the interior permanent magnet synchronous motor (IPMSM) drives. The conventional proportional plus integrate(PI) control are very sensitive to step change of the command speed, parameter variations and load disturbance. To cope with these problems of the PI control, the estimated speeds are compensated by using the fuzzy logic controller (FLC). In the FLC used by the speed compensator of the IPMSM, the system control parameters are adjusted by the fuzzy rule based system, which is a logical model of the human behavior for process control. The effectiveness of algorithm is confirmed by the experiments.
Study on Separating Underwater Earth Field Anomaly Generated by a Ship
Lee, Kang-Jin ; Yang, Chang-Seop ; Jung, Hyun-Ju ; Kim, Dong-Hun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1412~1417
Magnetic anomaly generated around a ship is mainly due to the permanent magnetization(PM) and induced magnetization (IM) remaining on the hull. It is very difficult to predict the direction and its magnitude of the permanent magnetization distributed over the hull, that is caused by mechanical or thermal stress. In this paper, an effective method is proposed to separate two components, the one produced by PM and the other by IM, from the underwater earth field signal distorted by the ferromagnetic material of the ship. The method can easily provide the two kinds of magnetic anomaly through exploiting experimental results and 3D electromagnetic field analyses even though the PM distribution on the hull is not known. To validate the proposed method, a model ship is manufactured and tested. The results would be of much help to basis research for securing safe navigation of a ship against dangerous factors in underwater.
Optimal Design of the LLC HB Resonant Converter for Notebook Computer Adapter
Yoo, Byoung-Seon ; Kim, Chang-Sun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1418~1423
The topology of LLC half bridge resonant converter provides ZVS characteristic. The voltage stress and current stress are smaller than that of the general resonant converters. So the LLC HB resonant converter can be considered as a optimal circuit for the notebook computer adapter. In the adapter design, we should consider the weight, the size and the overheat of the adapter. Thus the higher efficiency is an essential particular. First of all, the optimal design of transformer is the most important facts. Some parameters should be considered in order to get the highest efficiency. The adapter is designed through the considering of these parameters including the PFC circuit as the pre-regulator. It converts AC line input into about DC 390V link voltage of the LLC HB converter input and the converter has 16V/90W ratings. The efficiency measured is about up to 93%.
One-Touch Type Immunosenging Lab-on-a-chip for Portable Point-of-care System
Park, Sin-Wook ; Kang, Tae-Ho ; Lee, Jun-Hwang ; Yoon, Hyun-C. ; Yang, Sang-Sik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1424~1429
This paper presents a simple and reliable one-touch type multi-immunosensing lab-on-a-chip (LOC) detecting antibodies as multi-disease markers using electrochemical method suitable for a portable point-of-care system (POCS). The multi-stacked LOC consists of a PDMS space layer for liquids loading, a PDMS valve layer with 50 im in height for the membrane, a PDMS channel layer for the fluid paths, and a glass layer for multi electrodes. For the disposable immunoassay which needs sequential flow control of sample and buffer liquids according to the designed strategies, reliable and easy-controlled on-chip operation mechanisms without any electric power are necessary. The driving forces of sequential liquids transfer are the capillary attraction force and the pneumatic pressure generated by air bladder push. These passive fluid transport mechanisms are suitable for single-use LOC module. Prior to the application of detection of the antibody as a disease marker, the model experiments were performed with anti-DNP antibody and anti-biotin antibody as target analytes. The flow test results demonstrate that we can control the fluid flow easily by using the capillary stop valve and the PDMS check valves. By the model tests, we confirmed that the proposed LOC is easily applicable to the bioanalytic immunosensors using bioelectrocatalysis.
Development of Batteryless SAW-based Integrated Microsensor and Wireless Measurement Technique
Oh, Hae-Kwan ; Kim, Tae-Hyun ; Wang, Wen ; Yang, Sang-Sik ; Lee, Kee-Keun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1430~1435
We developed a 440MHz surface acoustic wave (SAW) microsensor integrated with pressure-temperature sensors and ID tag. Two piezoelectric substrates were bonded, in which
cavity was structured. Four sides were completely sealed by JSR photoresist (PR). Pressure sensor was placed on the top substrate, whereas ill tag and temperature sensor were placed on the bottom substrate. Using network analyzer, the developed microsensor was wirelessly tested. Sharp reflection peaks with high S/N ratio, small signal attenuation, and small spurious peaks were observed. All the reflection peaks were well matched with the coupling of mode (COM) simulation results. With a 10mW RF power from the network analyzer, a
meter readout distance was observed. Eight sharp ON reflection peaks were observed for ID tag. Temperature sensor was characterized from
. A large phase shift per unit temperature change was observed. The evaluated sensitivity was
A Fabrication Method of Blade Type Tip for Probe Unit Device
Lee, Keun-Woo ; Lee, Jae-Hong ; Kim, Chang-Kyo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1436~1440
Beryllium copper has been known to be an important material for the various fields of industry because it can be used for mechanical and electrical/electronic components that are subjected to elevated temperatures (up to
for short times). Blade type tip for probing the cells of liquid crystal display(LCD) was fabricated using beryllium copper foil. The dry film resist was employed as a mask for patterning of the blade type tip. The beryllium copper foil was etched using hydrochloric acidic iron-chloride solution. The concentration, temperature, and composition ratio of hydrochloric acidic iron-chloride solution affect the etching characteristics of beryllium copper foil. Nickel with the thickness of
was electroplated on the patterned copper beryllium foil for enhancing its hardness, followed by electroplating gold for increasing its electrical conductivity. Finally, the dry film resist on the bridge was removed and half of the nickel was etched to complete the blade type tip.
Fabrication of MEMS Inkjet Head for Drop-on-Demand Ejection of Electrostatic Force Method
Son, S.U. ; Kim, Y.M. ; Choi, J.Y. ; Ko, H.S. ; Kim, Y.J. ; Byun, D.Y. ; Lee, S.H. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1441~1444
This paper presents a novel electrostatic drop-an-demand ejector with a conductive pole inside nozzle. The MEMS fabricated pole-type nozzle shows a significant improvement in the performance and reliability of forming meniscus and generating a micro dripping mode of droplet out of the meniscus. It is verified experimentally that the use of the pole-type nozzle. The liquid is used D20+SDS+SWNT (5 %wt). The gap between upper electrode and nozzle is about 600 um. Electrostatic drop-an-demand ejection is observed when a DC voltage of 1.5 kV is applied between the control electrode and ground electrode. Droplet diameter is
The Analysis of Drop-On-Demand Characteristic of Electrostatic Field Induced Inkjet Head System with Carbon Nano Tube (CNT) Ink
Choi, J.Y. ; Kim, Y.J. ; Son, S.U. ; Kim, Y.M. ; Byun, D.Y. ; Ko, H.S. ; Lee, S.H. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1445~1449
This paper presents the DOD (Drop-On-Demand) characteristic using the electrostatic field induced inkjet printing system. In order to achieve the DOD characteristic of electrostatic field induced inkjet printing, applied the bias voltage of 1.4 kV and the pulse voltage of
using high voltage pulse generator. Electrostatic field induced droplet ejection is directly observed using a high-speed camera and for investigated DOD characteristic, CNT ink used. The electrostatic field induced inkjet head system has DOD characteristic using pulse generator which can be applied pulse voltage. The bias voltage has a good condition which form meniscus and has micro dripping mode for small size micro droplet. Also, the droplet size decreases with increasing the applied pulse voltage. This paper shows DOD characteristic at electrostatic field induced inkjet head system, Therefore. electrostatic DOD inkjet head system will be applied industrial area comparing conventional electrostatic inkjet head system.
A Study on the Microfabricated Clark-type Sensor for Measuring Dissolved Oxygen
Park, Jung-Il ; Chang, Jong-Hyeon ; Choi, Myung-Ki ; Lee, Dong-Young ; Kim, Young-Mi ; Pak, Jung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1450~1454
This paper presents a microfabricated Clark-type sensor which exactly can measure dissolved oxygen in the cell containing solution. We designed, fabricated, and characterized a microfabircated Clark-type oxygen sensor for measuring dissolved oxygen. The microfabricated oxygen sensor consists of 3-electrodes on a glass substrate, a FEP (Fluorinated ethylene propylene) oxygen-permeable membrane, and PDMS (Polydimethylsiloxane) reservoir for storing sample solution. Thin-film Ag/AgCl was employed as a reference electrode and its durability was verified by obtaining a stable open circuit potential for 2 hours against a commercial Ag/AgCl electrode and a stable cyclic voltammetry curve. Selectivity, response time, and linearity of the fabricated oxygen sensor were also verified well by cyclic voltammetry and amperometry depending. The fabricated oxygen sensor showed a 90% response time of 40sec and an excellent linearity with a correlation coefficient of 0.994.
Piezoelectric Microspeakers Fabricated with High Quality AlN Thin Film
Yi, Seung-Hwan ; Jung, Kyung-Sick ; Kim, Dong-Kee ; Shin, Gwang-Jae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1455~1460
This paper reports the piezoelectric microspeakers that are audible in open air with high quality piezoelectric AlN thin film deposited onto Mo/Ti electrode. This successful achievement, compared to the previous results, is followed by manipulating two material properties: the one is to use a compressively stressed silicon nitride film as a supporting diaphragm (even tensile stressed, around +20 MPa) and the another is to use high quality AlN thin film with compressive residual stress (less than -100 MPa). With these materials, the Sound Pressure Level (SPL) of the fabricated micro speakers shows more than 60 dB from 100 Hz to 15 kHz and the highest SPL is about 100 dB at 9.3 kHz with 20 Vpeak-to-peak sinusoidal input and with 10 mm distances from the fabricated micro speakers to the reference microphone (B&K Type 2669 & 4192L).
Development of a MEMS Structure for an Infrared Focal Plane Array
Cho, Seong-M. ; Yang, Woo-Seok ; Ryu, Ho-Jun ; Cheon, Sang-Hoon ; Yu, Byoung-Gon ; Choi, Chang-Auck ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1461~1465
A micromachined sensor part for an infrared focal plane array has been designed and fabricated. Amorphous silicon was adapted as a sensing material, and silicon nitride was used as a membrane material. To get a good efficiency of infrared absorption, the sensor was made as a
cavity structure. All the processes were done in
iMEMS fab. in the Electronics and Telecommunication Research Institute (ETRI). The processed MEMS sensor structure had a small membrane deflection less than
. This excellent deflection property can be attributed to the rigorous balancing of the stresses of individual layers. The efficiency of infrared absorption was more than 75% in the wavelength range
MEMS Design Flow Based on DFM Concept
Han, Seung-Oh ; Oh, Park-Kyoun ; Silva, Mark da ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1466~1470
MEMS design flow based on DFM concept is presented and applied to gyroscope design as a test case. It is purposed to contribute to the yield improvement by considering the process-related parameters from the design phase. After defining the performance requirements, the sensitivity analysis should be done on the draft design(s) to find out the key parameters related with the device performance. By doing so, TEG can be designed for the selected process and/or material parameters. Through a set of test runs, the process capability is characterized and the material properties are extracted using the TEG. Then we can estimate the virtual yield of the current process for the designed device by running Monte Carlo analysis where the process and/or material property variations are considered. The estimated yield will make us redesign the device to be more robust or improve the current process to have the smaller variations.
FR-4 Embedded UWB Filter using Uniform Impedance Resonator
Yang, Chang-S. ; Yoon, Sang-K. ; Park, Jae-Y. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1471~1475
In this paper, a novel embedded ultra wideband (UWB) band-pass filter is presented on a FR-4 package substrate including high Dk resin coated copper (
) film. The proposed UWB filter is comprised of a parallel resonator with meander-type uniform impedance resonator (UIR) and two series resonators with high Q circular stacked spiral inductor and metal-insulator-metal (MIM) capacitor. In order to obtain excellent attenuation characteristics by generating attenuation poles in lower and upper stop bands, a single MIM capacitor is added to each resonator. The fabricated FR-4 embedded UWB filter has insertion loss of -1.0dB and return loss of -11dB, respectively. It has also extremely wide bandwidth (over 50%) and small size (
) which is compatible with LTCC devices.
The Performance Analysis of IMM-MPDA Filter in Multi-lag Out of Sequence Measurement Environment
Seo, Il-Hwan ; Song, Taek-Lyul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1476~1483
In a multi-sensor target tracking systems, the local sensors have the role of tracking the target and transferring the measurements to the fusion center. The measurements from the same target can arrive out of sequence called, the out-of-sequence measurements(OOSMs). The OOSM can arise in a form of single-lag or multi-lag throughout the transfer at the fusion center. The recursive retrodiction step was proposed to update the current state estimates with the multi-lag OOSM from the several previous papers. The real world has the possible situations that the maneuvering target informations can arrive at the fusion center with the random clutter in the possible OOSMs. In this paper, we incorporate the IMM-MPDA(Interacting Multiple Model - Most Probable Data Association) into the multi-lag OOSM update. The performance of the IMM-MPDA filter with multi-lag OOSM update is analyzed for the various clutter densities, OOSM lag numbers, and target maneuvering indexes. Simulation results show that IMM-MPDA is sufficient to be used in out of sequence environment and it is necessary to correct the current state estimates with OOSM except a very old OOSM.
A Technique of Watermark Generation and Similarity Embedding for Still Images Based on Cross Reference Points
Lee, Hang-Chan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1484~1490
The Cross Reference Point(CRP) is a robust method for finding salient points in watermarking systems because it is based on the geometrical structure of a normalized image in order to avoid pointing error caused by digital attacks. After normalization of an image, the 100 CRPs are calculated. Next, the 100 blocks centered by CRPS are formed. These 100 blocks are arranged using a secrete key. Each boundary of 50 out of 100 blocks is surrounded by 8 blocks which are selected by the ordered number of a preceding block. This number is a seed of random number generator for selecting 8 out of 50 blocks. The search area of a center block is formed by a secrete key. The pixels of a center block are quantized to 10 levels by predefined thresholds. The watermarks are generated by the 50 quantized center blocks. These watermarks are embedded directly in the remaining 50 blocks. In other words, 50 out of 100 blocks are utilized to generate watermarks and the remaining 50 blocks are used to watermark embedding. Because the watermarks are generated in the given images, we can successfully detect watermarks after several digital attacks. The reason is that the blocks for the generation and detection of watermarks are equally affected by digital attacks except for the case of local distortion such as cropping.
Robust Non-fragile Guaranteed Cost Control for Uncertain Descriptor Systems with State Delay
Kim, Jong-Hae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1491~1497
This paper considers robust and non-fragile guaranteed cost controller design method for descriptor systems with parameter uncertainties and time delay, and static state feedback controller with gain variations. The existence condition of controller, the design method of controller, the upper bound to minimize guaranteed cost function, and the measure of non-fragility in controller are proposed using linear matrix inequality (LMI) technique, which can be solved efficiently by convex optimization. Therefore, the presented robust and non-fragile guaranteed cost controller guarantees the asymptotic stability and non-fragility of the closed loop systems in spite of parameter uncertainties, time delay, and controller fragility.
Frequency/Amplitude Separation Algorithm Using the Higher Order Differential Energy Operator and Its Application
Iem, Byeong-Gwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1498~1502
There have been many different definitions of energy functions as the second statistics of a signal. In this paper, using the higher order differential energy function, we propose an algorithm separating the amplitude and frequency components in a discrete sinusoidal signal. The proposed amplitude and frequency estimation methods have less computational requirement than the existing methods. It also shows large computational advantage over the root mean square (RMS) calculation of a signal. The proposed methods can be used in the detection of abnormal events in signals on the power line. Computer simulations show that proposed frequency estimation method can detect the presence of voltage increase or decrease for a short period of time. Also, the proposed estimation methods have been compared with existing methods in terms of estimation error variance.
Development of a Detect-and-Acquisition System for Broadband Lightning Signals
Song, Seung-Hun ; Kim, Dong-Hyouc ; Lee, Sung-Ho ; Woo, Jung-Wook ; Sung, Tae-Kyung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1503~1510
To implement a high-precision lightning tracking system utilizing TDOA measurements, high-speed data acquisition and precise timing synchronization between ground sensors should be achieved. At the same time, considering the size of digitizer's memory, the data memory needs to be managed so that only the sampled data around the occurrence of stepped leader pulse is stored. This paper presents a detection-and-acquisition system for lightning signals that is the main equipment of ground sensor in lightning tracking system. GPS clock module is used to get precise timing synchronization and the 500MHz high speed digitizer is employed. In order to detect the leading edge of the lightning pulse and save the sampled data and its timing, lightning detection module is implemented and multi-record method is employed in the proposed system. Field experiment results show that the proposed system can detect and save the lightning signal efficiently.
A New Fingerprint Reference-Point Detection Method Using Cosine Component
Song, Young-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1511~1513
A new reference point location method using the cosine component is proposed, where an edge map is defined and used to find the reference point. Because all processes used in the proposed method are performed at the block level, less processing time is required. Experimental results show that the proposed method can effectively detect the reference point with higher speed and accuracy for all types of fingerprints.
Analysis of Relations Between Physiologic Parameters and Pulse Transit Time on the Ultrasound Therapy
Kim, Sung-Min ; Choi, Sang-Hyuk ; Lee, Man-Pyo ; Choi, Byeong-Cheol ; Jung, Whoi-Seong ; Park, Sung-Yoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 56, issue 8, 2007, Pages 1514~1520
Currently, the signal of the human body is measured with various methods, and a noninvasive investigation of various methods is useful diagnosis method. PTT(Pulse Transit Time) which is noninvasive investigation make use of to estimate the physiological phenomena. PTT has a latent information of cardiovascular system. So we have the experiments for analysis of the relations between PTT and physiological parameters. We examine to correlate to the physiological parameters, an age and degree of paralysis on the ultrasound therapy. The 40 patients who has a such paralysis join our experiment, and we obtain the PTT data that normal condition and states after ultrasound therapy. We study that PTT after the ultrasound therapy for patients who have a paralysis was related to an age and degree of paralysis.