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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 6, Issue 8 - Dec 2002
Volume 6, Issue 7 - Nov 2002
Volume 6, Issue 6 - Oct 2002
Volume 6, Issue 5 - Aug 2002
Volume 6, Issue 4 - Jun 2002
Volume 6, Issue 3 - May 2002
Volume 6, Issue 2 - Apr 2002
Volume 6, Issue 1 - Feb 2002
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Performance Analysis of FH/CPFSK System in the Partial-band Jamming Noise
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 499~504
In this paper, we analyzed the performance of FH/CPFSK system with differential detection in thermal noise, partial-band jamming noise and adjacent interference of all eight bit pattern. The parameters to analize performances of FH/CPFSK system have been used the bit rate, modulation index and performances of FH/CPFSK system with the differential detector have been presented with the optimum correlation function. And, we were compared with performance of FH/CPFSK and FH/BFSK system. In result, we could know that bit error probability of the approximation equation and exact equation nearly accorded in the high signal-to-noise ratio. And, we have been proved that FH/CPFSK system with differential detection according to jamming fraction
was worst to 3dB than FH/CPFSK system with limiter-discriminator. but was superior to 2dB than FH/BFSK.
The Monitoring System for Informing the Change of Contents on the Web Sites
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 505~512
Fast spreading of web made we get easily the vast amount of information all over the world, but quantity of great information on the Internet space is giving much troubles to recognize change of information that users are interested soon justly. That is, users must connect and examine one by one to relevant site to detect change of web documents that changes from time to time. Therefore, the development of Robot which accomplish Information change monitoring function that sense automatically changed contents and inform to user is required. In this paper, we designed and implemented Web site contents change monitoring system, which notify-automatically the change of Web documents to users through alarm or E-mail if user defines target URL to do monitoring, monitoring condition, monitoring period etc. And we presented the method that structure and classify Web Documents to semantic units using HTML Tag. Also, we introduced the concept of virtual key to manage position of word to watch some change efficiently.
A Study on Denoising Method using Wavelet in Impulse Noise Environment
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 513~518
This paper presents the new method for removing impulse noise using wavelet. Time and frequency-localization capabilities in denoising can provide excellent specialties comparing with the existing methods, because of including detail information of signal. The method in this paper, using denoising by threshold and slope of signal by wavelet, has superior denoising effect and can recognize edge of original signal. For objective judgement, the test signals are used HeaviSine and DTMF and this paper simulated by test signals which have added to impulse noise of different site individually.
A Study on the design of the Microstrip Patch Array Antenna for Doppler Radar
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 519~526
In this paper, a microstrip patch array antenna for a Doppler radar at 10.525GHz is desinged and fabricated. To be used for mobile radar system, the antenna is fabricated on a single layer laminate to resist a fire impact and is covered with the Teflon foam. To obtain the desired characteristics, the array antenna is designed 4
8 array using a corporate 3-dB amplitude taper. Also, using square patch elements, the antenna can be converted to a circular polarized antenna later. The designed and fabricated array antenna has the reflection coefficient
-53.498dB, the horizontal beam width of
, the vertical beam width of
, the gain of 21dBi, the bandwidth of 220MHz for VSWR<1.5 and a side lobe level of less than -17.5dB.
The Acquisition of the PN Code in the DS/CDMA System Considering Phase Error and Rake Receiver
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 527~534
In this paper, efficiency in the acquisition of the PN code of the DS/CDMA system was analyzed by using the Nakagami-m probability density function that can model diverse fading channels. The system considers the fading environment that inevitably exists in the mobile communications channel environment. To analyze the efficiency of the system, the equations related to detection probability PD and false alarm probability PFA required for the acquisition of the PN code were induced by using the Nakagami-m probability density function. They were verified through simulation. For the DS/CDMA system an adaptive serial search technique was applied to acquire the PN code. To correct phase error, the equations related to detection probability PD and false alarm probability PFA that influence the time to acquire codes were induced after adding the PLL to each branch of the Rake Receiver. By using an induced equation, detection probability PD and false alarm probability PFA were verified through simulation.
/8 shift 8PSK-OFDM with Sliding Multiple Symbol Detection
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 535~543
In this paper, we propose
/8 shift 8PSK and trellis-coded
/8 shift 8PSK-OFDM techniques by applying
/4 shift QPSK to trellis-coded modulation (TCM), and performing signal set expansion and set partition correspondingly based on phase difference. In our Viterbi decoding algorithm, up to L phase differences from successively received symbols are employed in the new branch metrics. Such sliding multiple symbol detection (SMSD) method provides improved bit-error-rate (BER) performance in the differential detection of the trellis-coded
/8 shift 8PSK-OFDM signals. The performance improvements are achieved for different communication channels without sacrificing bandwidth and power efficiency. It thus makes the proposed modulation and sliding detection scheme more attractive for power and band-limited systems.
Performance Analysis of Reed-Solomon Coded DS/CDMA System in Mixed Fading Channel
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 544~551
In this paper, BER performance of DS/CDMA-BPSK system is analyzed in mixed lading channel that is consist of Rayleigh fadins Rician fading, and shadowed Rician fading. From the results, we know that proposed mixed fading model is very suitable to describe the different channel situations. and, the occupancy probability and the shadowing depth are very dependent to the system performance. Finally, we know that the Reed-Solomon coded DS/ CDMA-BPSK system is very robust to simultaneous user interference and mixed lading channel.
A Study on a Queue Management Scheme for Alleviating the Impact of Packet Size on the Throughput
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 552~558
Differentiated services (DiffServ) architecture defines a new framework for the support of quality of service (QoS) in IP-based networks. RIO has received the most attention among all the active queue management mechanisms proposed for assured service in DiffServ environment. The paper proposed the enhanced RIO which could alleviate the impact of flow's packet sire on the realized throughput. The simulation results indicate that this mechanism, when combined with TSW as traffic conditioner, provide better throughput assurance and fair distribution of excess bandwidth independent of packet size of flows in case of well-provisioned network environment.
A Design and Implementation of Web-based Instruction for Individual-paced learning using Push and Pull Technologies
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 559~566
n this paper, we propose a WBI(Web Based Instruction) for individualized learning using push and pull technologies with WWW(World Wide Web). As well as push End pull technologies, the proposing system is implemented with JSP(Java Server Page) and JDBC(Java Database Connectivity) of java technologies based on the client/server envirionments for the purpose of providing practical lectures to students.
An Efficient symbol Synchronization Scheme with an Interpolator for Receiving in OFDM
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 567~573
In this paper, we propose a new symbol time synchronization scheme suitable for the OFDM system with an interpolator. The proposed scheme performs the following three steps. In the first step, the coarse symbol time synchronization is achieved by continuously measuring the average power of the received envelope signal. Based on this average power, the detection possibility for the symbol time synchronization is determined. It the signal is sufficient for synchronization, we next perform a relatively accurate symbol time synchronization by measuring the correlation between a short training signal and the received envelope signal. Finally, an additional frequency synchronization is performed with a long training signal to correct symbol synchronization errors caused by the phase rotation. From the simulation results, one can see that the proposed synchronization scheme provides a good synchronization performance over frequency selective channels.
A Study on the optimization design of ATM network Using Internet Traffic Characteristics
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 574~581
Traditional queueing analyses are very useful for designing a network's capacity and predicting their performances, however most of the predicted results from the queueing analyses are quite different from the realistic measured performance. And recent empirical studies on LAN, WAN, and VBR traffic characteristic have indicated that the models used in the traditional Poisson assumption cannot properly predict the real traffic properties due to underestimation of the long-range dependence of network traffics and self-similar properties. In this paper, It is also shown that the self-similar traffic reflects real Ethernet traffic characteristics by comparing Pareto-like ON/OFF source model which is exactly self-similar model to the traditional Poisson model. It is also performed optimization design and performance analysis of ATM network using Internet traffic characteristics.
An Improvement of Sensorless Driving Performance for Brushless DC Motor with Trapezoidal Back EMF
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 582~588
This paper presents a efficient sensorless driving strategy for brushless dc motor(BLDCM). By varying PWM switching frequency(4KHz, 6KHz, 8KHz) properly according to the rotating speed, the improvement of the efficiency and the operating characteristics through the wide speed are obtained.. The experimental results show that the proposed method can efficiently improve the sensorless driving performance for BLDCM with trapezoidal back emf.
The Study of a Hairpin Line Resonator Filter Design by Using a J Inverter
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 589~594
The filter of hairpin type can be designed small but has a demerit which a design method is complex. This paper suggests the method that a hairpin line filter is designed with applying a transmission line method and J inverter circuit, accurately calculated the J value and the b parameter. It is considered about the line have no the mutual coupling element with next line to each other. is calculated a length of electric coupling line about coupling element in each inverter stage from the J value and the b parameter. In order to show the validity of the proposed design method, band pass filter of small hairpin line is designed at center frequency 2.6 GHz, with Serenade 8.0 software tool and the simulation characteristics are compared with design results.
A Study On the ASP Module in Conversational Automatic Speech Recognition Flight Information System
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 595~603
In this research, it has been shown that how the computer can recognize and understand spoken natural language and its symbolization using VoiceXML and Grammar Specific Language in developing telephone based conversational automatic speech recognition flight information system. In order for user to hear correct information, ASP Module has been revised and its effectivities has been experimented on the Voice portal airplane information system platform.
A Study on the Microstrip-Slotline Transition
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 604~609
Microstrip - slot line transitions are analyzed in the spectral domain. Some kinds of transitions which depend on the orientation angle between two lines and the stub types are designed and fabricated at 5GHz. It is shown that experiment results of the transition are in good agreement with those obtained from spectral domain analysis.
A Special Character Parameter Detection of mac Wave for a long-Distance Transmission
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 610~615
Being a medium to help understand the status of the whole body including the Five Vital Organs and the Six Viscera such as the heart, the mac is considered to represent the elasticity of the blood vessel and the condition of the bloodstream in the Oriental medicine. A doctor makes a subjective judgment on a patient's conditions based on the information derived from the diagnosis and the medical examination of the mac wave. Thus he or she needs objective records and make a decision based on them in order to prevent misdiagnosis. This paper set out to suggest the ways to detect the particular parameters of the mac wave with the methods to visualize the mac wave interpretation to detect basic documents(causes) of health status judgment in three-dimension and with the simulation.
Design and Implementation of a Fifthly Expanded Triangular Fractal Antenna
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 616~623
The fractal expanded antenna with the configuration of a triangular microstrip patch antenna is presented and analyzed. In the fundamental and higher mode of TFA(Triangular Fractal Antenna), resonant frequencies are controlled by changing the scaling factor. It is observed that increasing scaling factor makes the resonant frequency be spread, and decreasing scaling factor makes it be concentrated. The scaling factor is varied as the expansion and concentration of resonant frequencies. The resonant frequency in each fractal patch element is observed log -periodically. The TFA can be applied to the multiband system.
Binary Image Watermarking for Preserving Feature Regions
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 624~631
In this paper, an effective digital watermarking method for copyright protection of binary image data is proposed. First a binary image is grouped into feature regions which has geometrical features and general one. The watermark for authentication is embedded in general regions in order to preserve geometrical features regions. We have used run-length code and special runs for grouping feature regions and general one. For invisibility of watermark, we have embedded the watermark considering transition sensitivity of each pixel in general regions. The proposed method is applied some binary image such as character, signature, seal, and fingerprint image to evaluate performance. By the experimental results, the proposed method preserve feature regions of original image and have higher invisibility of watermarks.
A Study on the 3D Object Representation based WebSD Using X3D
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 632~638
Extensible 3D(X3D) is a software standard for defining interactive web and broadcast-based 3D content integrated with multimedia. The data size of Web3D representation based on polygon meshes is so large that transferring practical data fast is a hard problem. This paper proposes 3D object structure, a new framework for compact 3D representation with high quality surface shape. By utilizing a free form surface technique, qualified surface are transferred with limited amount of data size and rendered. 3D graphic structure can be regarded ad both polygon meshes and free form surfaces. Therefore, it can be easily integrated to existing Web3D data formats, for example VRML ＆ XML. 3D object structure also enables modeling free form surface shapes intuitively with polygon modeling like operations.
Data Department Linear Combination of Weighted Order Statistics(DD-LWOS) Filtering Based on Local Statistics
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 639~644
Nonlinear filters which are utilized rank-order information and temporal-order information, have many proposed, in order to restore nonstationary signals which are corrupted by additive noise. In this paper, we propose a data-dependent LWOS filter whose coefficients change based on local statistics. LWOS(Linear Combination of Weighted Order Statistics) filters［1］which also utilized two informations, and have properties of efficient impulsive and nonimpulsive noise attenuation and sufficiently details and edges preservation. DD-LWOS filters can remove non-impulsive oises while preserving signal details. DD-LWOS2 filter gets more better performance than DD-LWOS filter when input image corrupted by additive noise which includes Impulsive noise components.
A Study On Holistic Synthesis Human Face Images
Journal of the Korea Institute of Information and Communication Engineering, volume 6, issue 4, 2002, Pages 645~651
This paper presents a method to automatically synthesized human fare images from holistic descriptions. We compactly represent the face set by a small set of prototypes, which can be used in simple ways generated controlled morphings. This becomes possible because separation of 2D-shape and texture provides a faithful, closed and convex representation of images, and smooths the mapping between images and their properties. With this approach, the user watches an images being continuously morphed according to his indications, and the synthesized images always obey the natural physiognomic constraints.