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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Advanced Navigation Technology
Journal Basic Information
Journal DOI :
The Korea Navigation Institute
Editor in Chief :
Volume & Issues
Volume 10, Issue 4 - Dec 2006
Volume 10, Issue 3 - Sep 2006
Volume 10, Issue 2 - Jun 2006
Volume 10, Issue 1 - Mar 2006
Selecting the target year
Performance Analysis of Traffic Model and Location Estimation Algorithm with eTDOA Scheme in 2.45GHz Band RTLS
Jeong, Seung-Hee ; Lee, Hyun-Jae ; Ko, Bong-Jin ; Oh, Chang-Heon ; Lim, Choon-Sik ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 95~102
In this paper, we model a traffic of multiple tags operated in 2.45GHz band RTLS environment and analyze the multi-tag interference. Also, we propose a high precision location estimation algorithm of RTLS and then analyze its performance. From the results, the BER performance of RTLS degrades as the number of multi-tags increase in Gaussian noise and fading(m=15) environment. To meet the BER specification of RTLS,
, we have to limit the multi-tag number to below 40. We also estimate the tag's location in
searching-area with enhanced TDOA scheme. It is confirmed that the 3m radius within accuracy of RTLS specification is satisfied, if the number of sub-blink receives more than 2 when available reader is 3 to 8.
Improvement of Bit Error Rate through the Optimization of 320 Gbps WDM System with Non Zero-Dispersion Shifted Fiber
Lee, Seong-Real ; Yim, Hwang-Bin ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 103~113
The numerical methods of finding the optimal position of optical phase conjugator (OPC) and the optimal fiber dispersions are proposed, which are able to effectively compensate overall channels in
Gbps WDM system with non zero-dispersion shifted fiber (NZ-DSF) as an optical fiber. And BER characteristics in the system with two induced optimal parameters are compared with those in the system with the currently used mid-span spectral inversion (MSSI) in order to confirm the availability of the proposed methods. It is confirmed that two optimal parameters depend on each other, but less related with the searching procedure. The methods proposed in this research will be expected to alternate with the method of making a symmetrical distribution of power and local dispersion in real optical link which is a serious problem but the condition in the case of applying the OPC into multi-channels WDM system.
Vision-Based Robust Control of Robot Manipulators with Jacobian Uncertainty
Kim, Chin-Su ; Jie, Min-Seok ; Lee, Kang-Woong ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 113~120
In this paper, a vision-based robust controller for tracking the desired trajectory a robot manipulator is proposed. The trajectory is generated to move the feature point into the desired position which the robot follows to reach to the desired position. To compensate the parametric uncertainties of the robot manipulator which contain in the control input, the robust controller is proposed. In addition, if there are uncertainties in the Jacobian, to compensate it, a vision-based robust controller which has control input is proposed as well in this paper. The stability of the closed-loop system is shown by Lyapunov method. The performance of the proposed method is demonstrated by simulations and experiments on a two degree of freedom 5-link robot manipulators.
An Avoidance-Based Cache Consistency Algorithm without Unnecessary Callback
Kim, Chi-Yeon ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 120~127
Data-caching of a client is an important technology for interaction with a server where data are cached and operated at the client node. Caching reduces network latency and increases resource utilization at the client. In a Client-server environment, the absence of cache consistency algorithm, we cannot guarantee the correctness of client applications. In this paper, we propose a new asynchronous avoidance-based cache consistency algorithm. We remove the additional callback due to the lock escalation in AACC. With a comprehensive performance analysis, we show that the proposed algorithm has less message exchange than the AACC. One-copy serializability is used for proving correctness of the proposed algorithm.
Performance Analysis of Seamless Interworking Handover for Supporting MMS Continuity over WLAN and CDMA2000 Networks
Kim, Su-Yong ; Cho, Sung-Joon ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 128~137
Recently, the combination of WLAN and 3G wireless technologies will make MMS service more ubiquitous, bringing benefits to both service providers and their customers. To realize seamless MMS service over WLAN and CDMA2000 networks, we design novel seamless interworking architecture by reusing the existing standards and network elements at the same time. Based on the proposed seamless interworking architecture, we also present seamless notification architecture and seamless handover architecture that can't be possible within current MMS reference architecture. This paper will make a contribution for service providers to provide their customers with seamless MMS service over WLAN and CDMA2000 networks.
Variable Conversion Gain Mixer for Dual Mode Receiver
Park, Hyun-Woo ; Koo, Kyung-Heon ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 138~144
In this paper, dual mode FET mixer for WiBro and wireless LAN(WLAN) applications has been designed in the form of dual gate FET mixer by using the cascode structure of two single gate pHEMTs. The designed dual gate mixer has been optimized to have variable conversion gain for WiBro and WLAN applications in order to save dc power consumption. The LO to RF isolation of the designed mixer is more than 20dB from 2.3GHz to 2.5GHz band. With the LO power of 0dBm and RF power of -50dBm, the mixer shows 15dB conversion gain. When RF power increases from -50dBm to -20dBm, the conversion gain decreases to -2dB from 15dB with bias change. The variable conversion gain has several advantages. It can reduce the high dynamic range requirement of AGC burden at IF stage. Also, it can save the dc power dissipation of mixer up to 90%.
A Real-Time Obstacle Avoidance of Mobile Robot Using Nearness Diagram, Limit-Cycle and Vector Field Method
Kim, Pil-Gyeom ; Jung, Yoon-Ho ; Yoon, Jae-Ho ; Jie, Min-Seok ; Lee, Kang-Woong ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 145~151
In this paper, we propose a novel navigation method combined Nearness Diagram, Limit-Cycle method and the Vector Field Method for avoidance of unexpected obstacles in the dynamic environment. The Limit-Cycle method is used to obstacle avoidance in front of the robot and the Vector Field Method is used to obstacle avoidance in the side of robot. And the Nearness Diagram Navigation is used to obstacle avoidance in the nearness area of the robot. The performance of the proposed method is demonstrate by simulations.
Analysis of Electromagnetic Scattering by Resistive Strip Grating with Zero Resistivity at the Strip-Edges On a Grounded 2 Dielectric Layers
Yoon, Uei-Joong ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 152~158
In this paper, electromagnetic scattering problems by a resistive strip grating with zero resistivity at the strip-edges on a grounded 2 dielectric layers according as strip width and spacing, relative permittivity, thickness of dielectric layers, and incident angles of a electric wave are analyzed by applying the FGMM(Fourier-Galerkin Moment Method) known as a numerical procedure. The scattered electromagnetic fields are expanded in a series of floguet mode functions. The boundary conditions are applied to obtain the unknown field coefficients and the resistive boundary condition is used for the relationship between the tangential electric field and the electric current density on the strip. The tapered resistivity of resistive strips varies zero resistivity at strip edges. Then the induced surface current density on the resistive strip is expanded in a series of Chebyshev polynomials of the second kind. The normalized reflected power with zero resistivity in this paper show in good agreement with those of existing paper.
Compensation Characteristics of Optimized 640 Gbps WDM System Using Optical Phase Conjugator
Lee, Seong-Real ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 159~167
In this paper the numerical methods of finding the optimal position of optical phase conjugator (OPC) and the optimal fiber dispersion are proposed, which are able to effectively compensate overall channels in
Gbps WDM system. And the compensation characteristics in the system with two induced optimal parameters are compared with those in the system with the currently used mid-span spectral inversion (MSSI) in order to confirm the availability of the proposed methods. It is confirmed that the reception performances are largely improved in the system with the induced optimal parameters than in the system with MSSI through the analyzing the eye opening penalty (EOP) and bit error rate (BER) characteristics. It is also confirmed that two optimal parameters depend on each other, but are less related with the procedural problem about the first optimal value among these.
Design and Realization UHF Power Amplifier for Air Traffic Control
Kang, Suk-Youb ; Song, Byoung-Jin ; Park, Wook-Ki ; Go, Min-Ho ; Park, Hyo-Dal ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 167~172
In this paper, the 25W power amplifier for UHF band radio transceiver has been designed and realized. The power amplifier was composed of drive, power amplifier and control stages. Feedback topology and coaxial line baluns were used for wide band operation. The VDMOS, which has reliable performance for linearity and efficiency, was used for power device and designed to operate as push-pull amplification at Class AB Bias. The power amplifier designed in such a way was found to show stable AM modulation performance when voice signal was detected at the gate stage, with being designed and realized to meet output specifications of commercial air traffic control transmitter.
Airborne Pulsed Doppler Radar Development
Kwag, Young-Kil ; Choi, Min-Su ; Bae, Jae-Hoon ; Jeon, In-Pyung ; Yang, Ju-Yoel ;
The Journal of Advanced Navigation Technology, volume 10, issue 2, 2006, Pages 173~180
An airborne radar is an essential aviation electronic system of the aircraft to perform various missions in all weather environments. This paper presents the design, development, and test results of the multi-mode pulsed Doppler radar system test model for helicopter-borne flight test. This radar system consists of 4 LRU units, which include ANTU(Antenna Unit), TRU(Tx Rx Unit), RSDU(Radar Signal & Data Processing Unit) and DISU(Display Unit). The developed technologies include the TACCAR processor, planar array antenna, TWTA transmitter, coherent I/Q detector, digital pulse compression, DSP based Doppler FFT filtering, adaptive CFAR, IMU, and tracking capability. The design performance of the developed radar system is verified through various helicopter-borne field tests including MTD (Moving Target Detector) capability for the Doppler compensation due to the moving platform motion.