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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korea Institute of Information and Communication Engineering
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Journal DOI :
The Korean Institute of Information and Commucation Engineering
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Volume & Issues
Volume 5, Issue 7 - Dec 2001
Volume 5, Issue 6 - Oct 2001
Volume 5, Issue 5 - Sep 2001
Volume 5, Issue 4 - Jul 2001
Volume 5, Issue 3 - Jun 2001
Volume 5, Issue 2 - Jun 2001
Volume 5, Issue 1 - May 2001
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Performance Analysis of the Wide-band Radio Transmission System using a Multi-carrier Adaptive Modulation Schemes
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 621~629
In this thesis a wireless data transmission system has been proposed and analysed that uses the multi-carrier technique with the adaptive modulation scheme. In general, the OFDM(Orthogonal Frequency Division Multiplexing) system is assigning a same amount of information to all sub-carriers in a wireless data transmission. In the proposed system, the different amount of information is assigned to each sub-carrier depending on the state of channel and the target probability of error of system. With the proposed scheme, the transmission rate can be maximized with the fixed power and the required power to transmit the information can be minimized with the target probability of error of system.
The Design of Decimation Filters for High Precision Digital Audio Using FIR and IIR Filters
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 630~638
This paper has been proposed a structure composed of FIRs and IIR filters as digital decimation filter to compensate the drooping inband on the high precision AU chips. The area of chip has been reduced compared with the conventional structure because the RAM and MAC is reduced. The passband ripple
, passband attenuation(at $\; 0.4535 \times fs$ and stopband attenuation
of the 6th-order
modulator and digital decimation filter had
, -0.0013[dB] and -110[dB] respectively. Also the inband group delay, which was almost same compared with the conventional digital decimation filter structure, was 30.07/fs[s] band the error of group delay was 0.1672%.
Performance Improvement of Frequence Sharing of DS-CDMA/TDMA System
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 639~644
Sequence Code Division Multiple Access) and TDMA(Time Division Multiple Access) system. In this system, the narrowband TDMA signals can cause intolerant interferences to CDMA signals. In this paper, DS-CDMA/TDMA frequency sharing system have been analyzed in AWGN(Additive white Gaussian Noise), MAI (Multi Access Interference) and NI(Narrowband Interference) environment. Also, performance improvement has been obtained by adopting an adaptive notch filtering scheme using complex filter bank and CCI canceller.
Improvement Performance of DS-CDMA/QPSK System with Convolution Coding and MRC Diversity in Millimeter Wave RF Channels
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 645~652
In this paper is adopted the One-Ray Rician channel model for AVHS's platoon to short-range IVC (Inter-Vehicle Communication System) and analyzed packet probability characteristics in 60㎓ millimeter wave with very powerful to MP(multipath-wave). Both Convolution coding and MRC diversity is adopted that Multimedia service is satisfied following user's desire increase in the next and analyzed packet probability characteristics of DS-CDMA/QPSK systems.
The Phase Noise prediction and the third PLL systems on 1/f Noise Modeling of Frequency Synthesizer
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 653~660
In this paper, we designed 2303.15MHz frequency synthesizer for the purpose of the phase noise prediction. For the modeling of phase noise generated in the designed system through introducing the noise-modeling method suggested by Lascari we analyzed a variation of phase noise as according as that of offset frequency. Especially, for the third-order system of the PLL among some kinds of phase noise generated from VCO we analyzed the aspect of 1/f-noise appearing troubles in the low frequency band. Since it is difficult to analyze mathematically 1/f-noise in the third-order system of the PLL, introducing the concept of pseudo-damping factor has made an ease of the access of the 1/f-noise variance. we showed a numerical formula of 1/f-noise variance in the third-order system of the PLL which is compared with that of 1/f-noise variance in the second-order system of the PLL. As a result, In case of txco we found the reduce rapidly along the offset frequency after passed through that phase-noise was -160dBc/Hz before passed through a loop at 10kHz offset frequency and -162.6705dBc/kHz after passed through the loop, -180dBc/Hz at 100kHz offset frequency and -560dBc/kHz after passed through the loop. We can notice that the variance of third-order system more occurs (or the variance of second-order system in connection with noise bandwidth and variance factor of second-order and third-order system.
Improvement Performance of Truncated Type-II Hybrid ARQ Scheme and MRC Diversity Techniques using an Adaptive Modulation in DS -CDMA Cellular Mobile Communication System
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 661~667
This paper proposes a Truncated Type-II Hybrid ARQ scheme using an adaptive modulation system to achieve high throughput data transmission systems for DS-CDMA cellular mobile communication systems. In this paper, the adaptive modulation system analyzed in Nakagami (m-distribution) fading channel environment. The adaptive modulation system controls the modulation level and symbol rate according to the Nakagami fading parameter( m). When the received Eb/No is high or the Nakagami fading parameter m is high, the propose system selects higher modulation level and higher symbol rate to increase throughput. On the other hand, this system selects lower modulation level and lower symbol rate to prevent throughput performance degradation when the received Eb/No is low. The modulation method have been adopted QPSK 16QAM, 64QAM, 256QAM. Therefore, adaptive modulation systems with Truncated Type II Hybrid ARQ Scheme is proper for mobile and radio data communication system that require high reliability and delay-limited applications.
A Study on a Performance Analysis of Direct-Conversion Receiver In Additive White Gaussian Noise Channel
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 668~675
Recently, the performance of the commercial PCS(Personal Communication Service) system has been improved to the uppermost limit and ultimately the next generation mobile communication is to be realized by IMT-2000 (International Mobile Communication-2000) to provide multimedia services. Therefore, the new type receiving system is researched actively and one of the most important part in a receiver is direct conversion method. The direct conversion method is suitable for low power consumption, small size, MMIC, and low price, which is to be adopted to the next generation mobile communication systems. In this case, however, several problems occur due to DC-offset. The DC-offset suppresses amplification of the required signal because of the leakage signal of frequency synthesizer in the system. In this thesis, the removing method of DC-offset was considered. There are four removing techniques of DC-offset, which are AC-coupling, large capacitor, DC-feedback loop, and DC-free coding. Among these, the AC-coupling method is the most simplest method and the DC-feedback loop method has the best performance. Then, the performance of the AC-coupling method and DC-feedback loop method are evaluated by HP's ADS simulation tool. As a result, the AC-coupling method cannot be used to the digital communication systems due to data loss. On the other hand, it was confirmed that the DC-feedback loop method is suitable for the direct conversion receiver.
A Study on Construction of Maritime Disaters Prevention for Information Communication Network
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 676~683
This thesis is what accident in sea have been produced as lost themselves life and property about 500times at every years. Therefore this was induced to experiment on a national basis that the role of communication of ship is to move from lose themselves life and property as well as it is supply the information of shipwreck on all sailing the ship throughout construct the whole an intelligence network of system on a disaster at sea.
Performance Analysis of Trellis Coded OFDM/M-ary PSK Systems in the presence of tarrier Frequency Offset
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 684~691
In this paper, the BER performance of OFDM/M-ary PSK systems is analyzed with considering carrier-frequency offset and TCM technique, which encodes and modulations simultaneously, is adopted to OFDWM-ary PSK systems for compensation of performance degradation according to carrier-frequency offset. As a result of analysis, the error performance of OFDM/M-ary PSK systems is degraded as the frequency offset is increased. And the frequency offset should be below 0.025 in order to achieve
of 10 dB. Especially, when the TCM technique is adopted to OFDM/M-ary PSK systems, the performance improvement of about 4 dB is obtained in terms of
A Study on the Integrated Communication Systems for a Remote Control of Radio Communication Equipments
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 692~698
The radio communications by SSB and VHF transceivers are still used very efficiently in coast stations and military base stations. The communication system by the conventional SSB and VHF transceivers between a coast station and a terminal is an one-to-one system. In this dissertation, however, the conventional one-to-one system is expanded to one-to-multiple systems. Then, frequencies can be used effectively for distress, urgency, safety traffic, and military communications. An ICS has been proposed and added, in this dissertation, to the conventional SSB and VHF communication systems, which can realize one-to- several terminal communications. The line switching system by the ICS is to be remote-controlled by ASK modulated PTT signals and audio signals. An ICS can change a connection between terminal and transceiver through a circuit switching system at any time. For this purpose, the author has researched and developed a ASK transmission system, ICS system, control algorithm, multiprocessor system, and moni-toring system. As a conclusion, the developed line switching control systems and equipments can be used effectively for maritime communication, military communication, fishery communication, etc.
Performance Analysis of Wide-Band DS/CDMA Cellular System Using MRC Diversity
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 699~705
It is considered DPSK modulation and the channel is modeled as multipath Nakagami fading type which has been recently taken as a general model in the communication environments in this paper. Most paper assumed that Nakagami fading index(m) of each branch of Rake receiver was fixed the same value in recent years. However, Nakagami fading index(m) of each branch of Rake receiver takes several value through communication environments. In this case, the branch ,which takes a small Nakagami fading index(m), exclude. So we can improve performance. We are considered phase error and analyzed wideband DS/CDMA cellular system. When nakagami fading index(m) takes voluntary value, we analyze BER of wideband DS/CDMA cellular system. Finally, When the branch, which takes a small Nakagami fading index(m), exclude, we analyze BER of wideband DS/CDMA cellular system.
Analysis of the TCP performance over IEEE1394 based Home Networkings
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 706~715
TCP typically offers reasonable end-to-end performance to users regardless of the bandwidth and error characteristics of particular network technology, The robustness of TCP has contributed to its success in the internet environment. The role of communications is already well established in the office environment. With the advent of cheap, affordable broadband communications and the increasing complexity of consumer goods, it seems natural to extend the network into homes. In-home networking means a high-speed communication among the digital appliances within a home. Introduction of application over high-speed home network using TCP/IP protocol is increasing. The integrated environment of internet and home network is demanding as well. We have validated TCP model over high speed home network environment, investigated the throughput behavior of TCP over IEEE 1399 home networks, and evaluated a potential solution for high performance of TCP over IEEE 139t home networks. The simulation model has produced several interesting results in the performance of TCP over IEEE 1394 home network.
Congestion Control for Best-Effort Services In Wireless Networks
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 716~722
This paper has defined the 3G and beyond wireless networks as the one that is based on IP network architecture and proposed the congestion control scheme in the access networks. Basically the proposed method is built on the ECN(Explicit Congestion Notification) and utilizing the advantages of the wireless and I networks in broadcasting packet in their access network. Consequently it provides the efficiency in controlling the congestion that can be happened by the mobility support in the future wireless networks.
Object Picking and Concurrency for Solid Modeler in Collaborative Design System
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 723~729
We are able to work on the shared virtual space in Web-based Collaborative Design System using only Internet and Web browser. The users connect to the Solid Modeler Server through m and they create 3D shape and manipulate them variously. Then the users will share 3D objects and two problems can arise. The users must be able to pick the objects effectively which they want to manipulate. When one of the users manipulates a particular object, others should not disturb with the same object. In this paper, picking is implemented not only by computing intersection of mouse pointer with the objects of the virtual world, but also by using capabilities and attributes of scene graph node, by setting bounds intersection testing instead of geometric intersection testing, by limiting the scope of the pick testing, using Java 3D. These methods can reduce the computation of picking and can pick 3D objects effectively and easily using the system of hierarchy. To have effective concurrency, we used shared lock and exclusive lock as the action in work space.
Stabilization Control of Nonlinear System Using Adaptive Neuro-Fuzzy Controller
Lee, In-Yong ; Tack, Han-Ho ; Lee, Sang-Bae ; Park, Boo-Gue ;
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 730~737
In this paper, an stabilization control method using adaptive neuro-fuzzy controller(ANFC) is proposed for modeling of nonlinear complex systems. The proposed adaptive neuro-fuzzy controller implements system structure and parameter identification using the intelligent schemes together with optimization theory, linguistic fuzzy implication rules, and neural networks from input and output data of processes. The results show that the proposed method can produce the intelligence model with higher accuracy than other works achieved previously.
A Design of Fuzzy Control System for Moving Object Tracking
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 738~745
In this paper, when the moving object move to the three-dimentional space, the tracking system track the moving object using the fuzzy reasoning. The joint angle el of the manipulator rotate from
, and the joint angle
. The fuzzy singleton is used for fuzzification and the control rule is twenty five and the fuzzy inference method is simplified Mamdani's reasoning and the defuzzification is the SCOG(Simplified Center Of Gravity) of the fuzzy controller To measure of the performance of the designed system, the fuzzy controller is compared with the CTM(Computed Torque Method) controller at the same condition. when the disturbance torque is ON, the both of CTM and fuzzy controller tracked object without error, However, the disturbance torque changed 0.4N, the CTM controller is 10 times greater than fuzzy controller at the sum of absolute error difference. The designed system is showed it's robustness against with disturbance.
A Generalized Undeland Snubber for Flying Capacitor 3-level Inverter
Kim, In-Dong ;
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 746~755
This paper proposes a snubber circuit for flying capacitor 3-level inverter and converter. The proposed snubber circuit makes use of Undeland snubber as basic snubber unit. It has such an advantage of Undeland snubber used in the two-level inverter. Compared with conventional RLD/RCD snubber for 3-level inverter and converter, the proposed snubber keeps such good features as fewer number of components, reduction of voltage stress of main switching devices due to low overvoltage, and improved efficiency of system due to low snubber loss. In this paper, the proposed snubber is applied to multilevel flying capacitor inverter and its feature is demonstrated by computer simulation and experimental result.
A Dexterous Motion Control Method of Redundant Robot Manipulators based on Neural Optimization Networks
Hyun, Woong-Keun ; Jung, Young-Kee ;
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 756~765
An effective dexterous motion control method of redundant robot manipulators based on neural optimization network is proposed to satisfy multi-criteria such as singularity avoidance, minimizing energy consumption, and avoiding physical limits of actuator, while performing a given task. The method employs a neural optimization network with parallel processing capability, where only a simple geometric analysis for resolved motion of each joint is required instead of computing of the Jacobian and its pseudo inverse matrix. For dexterous motion, a joint geometric manipulability measure(JGMM) is proposed. JGMM evaluates a contribution of each joint differential motion in enlarging the length of the shortest axis among principal axes of the manipulability ellipsoid volume approximately obtained by a geometric analysis. Redundant robot manipulators is then controlled by neural optimization networks in such a way that 1) linear combination of the resolved motion by each joint differential motion should be equal to the desired velocity, 2) physical limits of joints are not violated, and 3) weighted sum of the square of each differential joint motion is minimized where weightings are adjusted by JGMM. To show the validity of the proposed method, several numerical examples are illustrated.
The Automatic Topology Construction of The Neural Network using the Fuzzy Rule
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 766~776
In the constructing of the multi layer neural network, the network topology is often chosen arbitrarily for different applications, and the optimum topology of the network is determined by the long processing of the trial and error. In this paper, we propose the automatic topology construction using the fuzzy rule that optimizes the neurons of hidden layer, and prune the weights connecting the hidden layer and the output layer during the training process. The simulation of pattern recognition, and the experiment of the mapping of the inverted pendulum showed the effectiveness of the proposed method.
A Study on the Design of Laterally Tilted SCH-SLD with Window Region
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 777~790
Theoretical analyses have been tried to design high power and stable operating SLD at 1.55
wavelength range which is the lowest absorption wavelength in optical fiber. The materials of active layer and SCH layer were chosen as conventional In1-xGaxAsyPl-y quaternary composition systems. From the transverse mode and the lateral mode analyses of waveguide, the optical power distributions and the optical confinement factor have been studied for single-mode high power operation. According to these analyses, it was calculated the composition and the thickness of SCH layer to obtain the maximum optical confinement factor. In order to obtain low values of the reflectivity, we used the window region and the lateral tilted angle between tile active region and window region. And the reflectivity of SLD was calculated with the gaussian beam approximation and mode analysis. From these researches, it was confirmed for several results to fabricate the efficient and stable SLD. In case of using
, InGaAsP SCH layer, the layer thickness was obtained
, to get the maximum optical confinement factor. Using
, active layer thickness and
, SCH layer thickness, the window region length is about
without An coating,
in 1% AR coating to obtain about 10-4 reflectivity. When the tilted angle is about
, the reflectivity is about 10-3. From these results, if the window region length and tilted angle were controlled appropriately in given device structure, it was confirmed that it is possible to fabricate the stable SLD without AR coating analytically.
High-Speed, Large-Capacity ATM switching-chip Implemented by MCM Technology
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 791~797
In this paper, high-speed ,large-capacity ATM switching-chip is developed by MCM technology. MCM technology is suited for light-weight portable communications, mobile computing, high-frequency applications. For test of the developed MCM switching-chips, the simulating model is made by VHDL code of previously developed chip and input-output values of modeling pattern are obtained through the simulation. After the pattern values in chip-test machine are inserted , their results are compared with the simulation results. The design in this paper is simulated by synopsys design tool using SUN workstation and functions of chip is measured by TRILLIUM machine. Simulated and measured results have been compared, showing close agreement. Last, the MCM technique presented in this paper will provide useful insight into future designs.
Design of Improved EMI Filter
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 798~806
As electronic industry and radio communication technologies progress, the electrical and electronic equipments are lightened, minimized, and operated by low power. At the same time, these equipments react sensitively by electromagnetic wave noise. It is a origine these equipments to wrong-operation. In this paper, we focused on the design and preperation condition of a advanced EMI filter. This filter sowed superior attenuation effect of 10 dB~20 dB compare with typical filter in the range of frequency from 150 kHz to 30 GHz and superior character over the variation of a load.
Design of Transceiver Front-end using Circular Sector Patch Antenna
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 807~811
In this paper we proposed a dual-frequency circular sector microstrip antenna with orthogonal polarized modes and high isolation between the two feeding ports. And then we designed a transceiver operating at 5.6 GHz for transmitting and at 5.5 GHz for receiving. The good isolation provided by the proposed antenna is used as the basis for the transmit-receive filtering of transceiver. The operating frequencies and polarization characteristics of the proposed antenna is calculated by using a cavity model. The 5-parameters and radiation patterns of the antenna are measured. A power amplifier and a low noise amplifier are designed and integrated with antenna to make a transceiver, which has about 13dB transmitting gain and about 8㏈ receiving gain.
Dual-frequency circular sector patch antenna
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 812~816
In this paper we designed a dual-frequency circular sector microstrip antenna fed microstrip line with orthogonal polarization. The operating frequencies and polarization characteristics of the proposed antenna is calculated by using a cavity model. The antenna operating at about 1.87 GHz and 2.42 GHz is fabricated and its S-parameters and radiation patterns are measured.
Microstrip patch antenna using 3 dimensional microstrip transition
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 817~821
In this paper, we design a microstrip patch antenna using 3-dimensional microstrip transition with the VSWR 1.3 over the PCS band (1.75 -1.87 GHz). We study experimentally the effect of the antenna parameters on antenna input impedance. And using the proposed antenna, we fabricate a polarization diversity any antenna and discuss the possibility of antenna for PCS base station.
Design of a High Gain Microstrip Antenna with Rectangular Cavity Backed
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 822~828
In this paper, a high gain microstrip antenna with rectangular cavity backed is designed. A single microstrip patch is basically a low gain radiator As a ga in enhancement method, superstrate loading techniques are applied to the
microstrip array antenna with cavity backed. In antenna design, although the broadside gain increases as the cavity is enlarged, a cavity size of
wavelength is sufficient. The distance between the radiating elements is chosen as 1.5 free-space wavelength. The antenna radiation characteristics are calculated by IE3D software and compared with the experimental results. Experimental results show that the maximum gain is 18.6dBi at the frequency of 9.16GHz, which is good agreement with the calculations.
Image Recognition and Its Application to Radiograph
Song, Chae-Uk ; Yea, Byeong-Deok ;
Journal of the Korea Institute of Information and Communication Engineering, volume 5, issue 4, 2001, Pages 829~840
In this study, we propose a method for quantifying the degree of advance of pulmonary emphysema by using chest X-ray images. With this method, we devise two schemes for this purpose. One is for detecting blood vessels by using a deformable model with the tree-like structure and using an evaluation function specialized by knowledge about blood vessels appeared in chest X-ray images, and the other is for quantifying the degree of advance by using several features, which were extracted from blood vessels, and the equation of quantitative evaluation. In order to evaluate the performance, we applied the proposed method to 189 ROIs(Regions of Interest) of ten chest X-ray images and compared the values by the proposed method with those by a medical doctor.