Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Journal of Advanced Navigation Technology
Journal Basic Information
Journal DOI :
The Korea Navigation Institute
Editor in Chief :
Volume & Issues
Volume 11, Issue 4 - Dec 2007
Volume 11, Issue 3 - Sep 2007
Volume 11, Issue 2 - Jun 2007
Volume 11, Issue 1 - Mar 2007
Selecting the target year
Unmanned Ground Vehicle Control and Modeling for Lane Tracking and Obstacle Avoidance
Yu, Hwan-Shin ; Kim, Sang-Gyum ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 359~370
Lane tracking and obstacle avoidance are considered two of the key technologies on an unmanned ground vehicle system. In this paper, we propose a method of lane tracking and obstacle avoidance, which can be expressed as vehicle control, modeling, and sensor experiments. First, obstacle avoidance consists of two parts: a longitudinal control system for acceleration and deceleration and a lateral control system for steering control. Each system is used for unmanned ground vehicle control, which notes the vehicle's location, recognizes obstacles surrounding it, and makes a decision how fast to proceed according to circumstances. During the operation, the control strategy of the vehicle can detect obstacle and perform obstacle avoidance on the road, which involves vehicle velocity. Second, we explain a method of lane tracking by means of a vision system, which consists of two parts: First, vehicle control is included in the road model through lateral and longitudinal control. Second, the image processing method deals with the lane tracking method, the image processing algorithm, and the filtering method. Finally, in this paper, we propose a method for vehicle control, modeling, lane tracking, and obstacle avoidance, which are confirmed through vehicles tests.
Ionospheric Modeling using Wavelet for WADGPS
Sohn, Kyoung-Ho ; Kee, Chang-Don ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 371~377
Ionospheric time delay is one of the main error source for single-frequency DGPS applications, including time transfer and Wide Area Differential GPS (WADGPS). Grid-based algorithm was already developed for WADGPS but that algorithm is not applicable to geomagnetic storm condition in accuracy and management. In geomagnetic storm condition, the spatial distribution of vertical ionospheric delay is noisy and therefore the accuracy of modeling become low in grid-based algorithm. For better accuracy, function based algorithm can be used but the continuity of correction message is not guranteed. In this paper, we propose the ionospheric model using wavelet based algorithm. This algorithm shows better accuracy with the same number of correction message than the existing spherical harmonics algorithm and guarantees the continuity of correction messages when the number of message is expanded for geomagnetic storm condition.
Autonomous Navigation Algorithm Development with Extended Kalman Filter and Sliding Mode Control
Yun, Duk-Sun ; Yu, Hwan-Shin ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 378~387
In this paper, Authors develop and verify the algorithm for enhancing the performance of Unmanned vehicle's Autonomous navigation, and also propose the method of establishing much more precise Navigation locus. Unmanned vehicle has a destination, however orientation is not notified, which make it find the future orientation itself. Extended Kalman Filter make it access to the desirable direction, which coupled with INS and GPS is proposed in this paper. Sliding mode control could overcome the side slip and lateral minor movement of the vehicle. The test result would shows the effectiveness of Extended kalman filter and Slide mode control for the navigation.
The Most and Least Greedy Algorithms for Integer Bit Allocation
Lim, Jong-Tae ; Yoo, Do-Sik ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 388~393
In designing transform coders bit allocation is one of the important issues. In this paper we propose two optimal algorithms for integer bit allocation in transform coding. Based on high-resolution formulas for bit allocation, the most and least greedy algorithms are developed to optimally adjust non-integer bit rates of coefficient quantizers to integer values. In particular, a duality property is observed between the two greedy algorithms.
Effective Compensation of Distorted WDM Signals Related with Frequency Chirp
Lee, Seong-Real ; Yim, Hwang-Bin ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 394~400
We induced the optimal values of optical phase conjugator (OPC) position and dispersion coefficients of fiber sections depending on frequency chirp, which is substantially generated in optical signal by optical modulator and affects the transmission performances. In order to investigate the relation of optimal parameters with various frequency chirp, in this paper, positive(down) chirp, chirp-free and positive(up) chirp are assumed in 40 Gbps
16 channels WDM transmission system of NRZ format with extinction ratio of 10 dB, which are the worst system parameters in the factor affecting system performance. It is confirmed that the OPC position offset and dispersion offsets between both fiber sections are more increased as frequency chirp become larger. It is also confirmed that the effect of the induced values on the compensation of WDM channels with negative frequency chirp is better than WDM channels with positive frequency chirp.
Circular Ethernet-based In-Vehicle Network Protocol
Park, Pu-Sik ; Cho, Jong-Chan ; Yoon, Jong-Ho ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 401~407
This paper proposes the ethernet-based in-vehicle networking method for "body" and "multimedia" domains. The ethernet-based in-vehicle networking method should modify the topology and the layer 2 for traffic shaping. In this paper, we simulate the two ring networking systems, the Media Oriented Systems Transport (MOST) and the proposed system with the shaping by the network simulator 2 and evaluate each performance. In addition, we demonstrate the proposed networking system to exchange two kinds of traffic, i.e., QoS data and best-effort data, on the ring network constituting of three nodes. Finally this paper expects to substitute the ethernet-based in-vehicle network for the MOST in advance.
Performance Analysis of Coded FSK System for Multi-hop Wireless Sensor Networks
Oh, Kyu-Tae ; Roh, Jae-Sung ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 408~414
Research advances in the areas of micro-sensor device and wireless network technology, has made it possible to develop energy efficient and low cost wireless sensor nodes. In this paper, the forward error control (FEC) scheme for lower power consumption and excellent BER(Bit Error Rate) performance during transmission propose in multi-hop wireless sensor network based on FSK modem. The FEC technique uses extra processing power related to encoding and decoding, it is need complex functions to be built into the sensor node. The probability of receiving a correct bit and codeword for relaying a frame over h nodes to the sink node is calculated as a function of channel parameter, number of hops, number of bits transmitted and the distance between the different nodes.
Dynamic Channel Allocation Algorithm for TD-SCDMA Smart Antenna System with Inter-cell Interference
Jang, Min-Seok ; Hong, Een-Kee ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 415~422
In this paper, we proposed a new dynamic channel allocation algorithm for TD-SCDMA with cross time slots. In order to reduce the interference in cross time slot, the mobile stations (MSs) are divided into two groups: the Near Group consisting of MSs near by the base station(BS) and the Far Group including the MSs far from the BS. The reverse link for MSs in the Near Group and forward link for MSs in the Far Group are allocated to the cross time slot. In cellular systems, a BS has multiple neighbor BSs. Some of neighbor BSs can operate in the same direction link while the others have cross time slot. Thus, it is required to determine which BS has the most significant impact in terms of interference. We divide each cell into 6 areas based on the direction of arrival of smart antenna and the most significant neighbor sector is determined with this division. The proposed allocation method and area division method can avoid the severe interference in cross time slots and increase the system capacity about 2%~9% compared to FCA, and 0.5%~1.3% compared to RCA.
Energy Efficiency for Building Security Application of Adaptive Error Control and Adaptive Modulation
Long, Bora ; Kang, Heau-Jo ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 423~429
Since the wireless smart card has played a main role in the identification security application for the building access; this research has its purpose to improve the performance of the smart card system and aims to offer more convenient to user. The contactless cards do not require insertion into a card reader and can work up to centimeters away from the reading device. To be able to cope with this performance the controlling of power consumption through the adaptive modulation and error control is needed. This paper addresses a forward error control (FEC) scheme with the adaptive Reed-Solomon code rate and an M-ary frequency shift keying (M-FSK) modulation scheme with the varying symbol size M over the link. The result of comparing energy efficiencies of adaptive error correction and adaptive modulation to other various static schemes shows to save over 50% of the energy consumption.
A Low Complexity Scheduling of Uplink Multiuser MIMO/FDD System
Cho, Sung-Yoon ; Kim, Yohan ; Kim, Dong-Ku ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 430~436
In this paper, we assume the uplink multiuser MIMO system based on FDD. Considering the implementation of practical system, Antenna selection and Transmit Beamforming scheme are suggested. System model of both two schemes are introduced and the scheduling algorithm which approaches the optimal performance with affordable computational complexity is proposed for each transmission scheme. Simulation results show that the sum-rate of the proposed low complexity scheduler approaches the performance of brute-force scheduler which is believed to be the optimal scheme.
Influence of Extinction Ratio on Optimal Parameters of OPC for Improving BER of WDM Signals
Lee, Seong-Real ; Kweon, Soon-Nyu ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 437~446
In this paper, we numerically induced the optimal values of optical phase conjugator (OPC) position and dispersion coefficients of fiber sections, which can improve the bit error rate (BER) and design the adaptive WDM transmission system, as a function of the extinction ratio (ER) of 10 dB and 20 dB in
Gb/s WDM transmission system. It is confirmed that these optimal parameter values for effectively compensating overall WDM channels are dependence on the extinction ratio of signals as well as modulation format, transmitted channel numbers, which were investigated in previous researches. It is also confirmed that ER of 20 dB has the advantage of designing flexible WDM systems using optimal parameters than ER of 10 dB.
Derivations of Gallager Random Coding Bound by Simple Manipulations of Algebraic Inequalities
Yoo, Do-Sik ; Lim, Jong-Tae ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 447~453
In this letter, we derive the Gallager random coding bound for discrete memoryless channels purely by simple manipulations of algebraic inequalities rather than invoking conceptually difficult random coding arguments. Gallager random coding bound is a very useful tool in information and coding theory due to its applicability to situations in which it is difficult to determine the decision regions and due to the fact that it can be used to derive the channel coding theorem. The readers will find it relatively easy to apply to many practical problems of interest the step-by-step algebraic derivations of the Gallager random coding bound with appropriate modifications.
Implementation and Evaluation of 2D Ray-Tracing Technique for Indoor Propagation Characteristics Modeling
Jeong, Seung-Heui ; Kang, Chul-Gyu ; Oh, Chang-Heon ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 454~460
In this paper, we implemented a ray-tracing simulator with a ray-launching technique and generated the propagation path of each ray in an multiple-wall indoor environment. In this simulator, we adopted two dimension ray-tracing techniques considering the reflection and penetration were dominant propagation factor in the indoor channel. From the result, we verified that this ray-tracing simulator shows the similar pattern and delay distribution with the experiment results of the previous research.
AODV Protocol with Load Distribution for Ubiquitous Sensor Networks
Jo, Young-Jun ; Kim, Seong-Chul ; Cho, Yong-Bum ; Cho, Sung-Joon ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 461~472
In Ubiquitous Sensor Network (USN), the sensor nodes are required to consume their energy evenly to prolong the lifetime of the entire sensor network because of the limited energy of the sensor node. AODV which is applied to USN as routing protocol selects route according to only the shortest distance of the minimum hop count but regardless of the remaining battery power for each node. Thus it comes to ill-balanced power consumption seriously. In this paper, a scheme that controls packet relay quantity of each sensor node adaptively to prevent traffic overhead at a certain node and to increase the entire network lifetime is proposed. As it is analyzed by simulations, the proposed scheme enhances USN lifetime by balancing each sensor node's packet relay quantity.
Design and Implementation of Serial Key Certification System Using Smartcard
Kim, Yu-Doo ; Moon, Il-Young ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 473~478
Current certification system use serial key for protect copyright of software and digital contents. But It is not efficient system, because It is not protect copyright through create virtual key or use public key. So we research on various cryptology for prevent illegal copy of serial key, but It is not enough protection of copyright that use software technology only. In this paper, we propose certification system using smart card for protect copyright of software and digital contents.
A Fault-Recovery Agent for Distance Education on Home Network Environment
Ko, Eung-Nam ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 479~484
This paper explains the design and implementation of the FRA(Fault Recovery Agent). FRA is a system that is suitable for recovering software error for multimedia distance education based on home network environment. In terms of distributed multimedia systems, the most important catagories for quality of service are a timeless, volume, and reliability. In this paper, we discuss a method for increasing reliability through fault tolerance. This paper explains a performance analysis of an error recovery system running on distributed multimedia environment using rule-based DEVS modeling and simulation techniques. In DEVS, a system has a time base, inputs, states, outputs, and functions. The proposed method is more efficient than the other method in comparison with error ration and processing time.
An Image Concealment Algorithm Using Fuzzy Inference
Kim, Ha-Sik ; Kim, Yoon-Ho ;
The Journal of Advanced Navigation Technology, volume 11, issue 4, 2007, Pages 485~492
In this paper, we propose the receiver block error detection of the video codec and the image concealment algorithm using fuzzy inference. The proposed error detection and concealment algorithm gets SSD(Summation of Squared Difference) and BMC(Boundary Matching Coefficient) using the temporal and spatial similarity between corresponded blocks in the two successive frames. Proportional constant,
, for threshold value, TH1 and TH2, is decided after fuzzy data is generated by each parameter. To examine the propriety of the proposed algorithm, random errors are inserted into the QCIF Susie standard image, then the error detection and concealment performance is simulated. To evaluate the efficiency of the algorithm, image quality is evaluated by PSNR for the error detection and concealed image by the existing VLC table and by the proposed method. In the experimental results, the error detection algorithm could detect all of the inserted error, the image quality is improved over 15dB after the error concealment compare to existing error detection algorithm.