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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
LORAN-C using and Position error improvement against being unable to use the Global Positioning System(GPS)
Goo, Ja-Heon ; Kang, Gwang-Won ; An, Young-Eun ; Han, Seung-Jo ; Park, Jong-An ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 1~8
Loran-C of ground transmitting station base that can prevent confusion of country navigation system and give BACK-UP function about electric wave navigation comparing utilization incapability state about GPS(Global Positioning System) infra that user is spreading rapidly over our society whole such as sea/aviation safety, vehicles navigation, minuteness agriculture, minuteness measurement in this treatise practical use of Loran-C navigation propose. Executed ASF(Additional Secondary Phase Factor) production and an application experiment Loran-C by location error improvement way to enhance practical use value. By the result Loran-C in conclusion that can improve location error 100~400m remarkably by 10~65m reach. Also, production extent is latitude when go composition medium and bends cotton at ASF revision table utilization of land area, this smell is judged to be suitable hardness 10 minutes. And notable location error improvement and numeric of GPS BACK-UP function are judged to be possible at a ASF revision table application to Korea Peninsula whole area hereafter.
Performance Analysis of VDL Mode-2 Transceiver and Generation of the Narrow Band Digital Modulated Signals
Gim, Jong-Man ; Kim, Tae-Sik ; Kim, In-Kyu ; Kim, Hyoun-Kyoung ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 9~16
In this paper, the Bit Error Ratio (BER) performances of the D8PSK modulation schemes for VDL Mode-2 are analyzed according to the matched and unmatched cases of the channel filters. The carrier frequency and phase offset effects are analyzed with unmatched case. Generally in digital transmission techniques, the Root Raised Cosine filters which are used as channel filters are applied to both sides at transmitter and receiver in order to achieve no ISI, but in VDL Mode-2, the Raised Cosine Filter is used only in transmission section and the receiver section uses general low pass filter, therefore we could not achieve ISI reduction effects but can have better spectrum quality. From the simulation results, the error probability is increased slightly (1~2dB) with use of un-matched channel filter, we got the conclusions that carrier phase offset do not effect to bit error ratio, but the frequency offset effect is so serious. Finally, narrow band D8PSK modulation signals are generated by the use of Digital Up-Converter and then its features are compared with analog modulator.
The Design and Performance Analysis of Physical Layer for VDL Mode-2
Choi, Jun-Su ; Lee, Han-Seong ; Kim, Tae-Sik ; Kim, In-Kyu ; Kim, Hyoun-Kyoung ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 17~23
This paper, describes the VDR physical layer design in VDL Mode-2 in order to meet the requirements of International standards. VDR's frequency band is 117.975~137MHz, and CSMA(Carrier Sense Multiple Access), D8PSK(Differential Eight Phase Shift Keyed), 25KHz's channel bandwidth use. The analysis of the isolated channel from near channels, sensitivity of the receiver, dynamic range of the receiver, linear of the transmitter and energy of spurious for linear and non-linear simulation as a requirement condition of performance of VDR and teaches the course of design. The transmitting power level should be lower than 5dB from Po1dB point and the selected IF frequency is 45MHz to suppress the spurious signals. The receiver designed has 4.5dB of Noise figure, 27.52dB of Es/No, Mixer isolation up to 30dB, IIP3 power of LNA up to +10dBm to minimize the intermodulation.
Inter-working Architecture for Seamless Handover and QoS in Heterogeneous Wireless Networks
Kim, Moon ; Moon, Tae-Wook ; Cho, Sung-Joon ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 24~30
The integration of WLAN and beyond 3G mobile networks offers the possibility of achieving anytime and anywhere Internet access. Moreover the requests for seamless multimedia services and the Quality of Service (QoS) support have been one of key issues in wireless networks. Therefore the researches relative to seamless multimedia service and QoS over heterogeneous wireless networks have been progressing rapidly. In this paper, we propose inter-working architecture for supporting seamless multimedia service and QoS over WLAN and WiBro networks. Based on the proposed inter-working architecture, we also provide both the seamless handover architecture such an inter-network vertical handover and the QoS-aware wireless Medium Access Control (MAC) scheme. In addition, we evaluate and compare the performance by Network Simulator-2 (NS-2) simulations.
Performance Analysis of TCP Using ErrorModel
Kim, Yu-Doo ; Moon, Il-Young ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 31~36
TCP (Transmission Control Protocol) is one of the protocols which are widely used from the Internet environments. Through the flow control of TCP, it could be increased efficiency for the loss and a re-transmission of data and the flow control become accomplished through window technique which puts the limit of size. By the flow control, TCP divided in various versions. In this paper, it is analyzed the simulation result which applies the error model in the Newreno which is an improved model of the representative Tahoe, Reno.
Performance Improvement of OFDM Systems in Broadband Wireless Communication Channel Environments
Kang, Heau-Jo ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 37~42
In this paper, we analyzed the performance of OFDM systems with adaptive equalizer that considers the frequency offset, the frequency non-selective fading, and two-path microwave Rummer's model channels. First of all, it is analyzed that the performance degradation, which is caused by the offset and the non-selective fading channel, through simulation. As the results of the simulation, the performance of the OFDM system is greatly influenced by the offset and channels. The more the frequency offset is, the worse the performance of the OFDM system is. However, if the adaptive equalizer is adopted to the OFDM system, the performance is enhanced up to the limited rang.
Performance Analysis of OFDM/64QAM System in Rummler Model based Cable Channel
Ahn, Jung Kil ; Kwak, Jae Min ; Park, Ki Sik ; Cho, Sung Eon ; Cho, Sung Joon ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 43~49
In this paper, the performance of OFDM/64QAM systems under Rummler model based cable channel is evaluated through computer simulation, and then the degree of performance improvement is estimated when adopting adaptive LMS equalizer. From the performance evaluation results, in the Rummler two-ray channel model, it is known that the performance improvement degree by adopting equalizer is greatly increased in case of attenuation coefficient of reflected ray (b) being less than 0.15, but when attenuation coeffcient (b) is larger than 0.15, the performance improvement degree by adopting equalizer shows little changes in almost all range of Eb/No.
Mid-Span Spectral Inversion Technique with Optimal Parameters in 640 Gbps WDM Transmission System over NZ-DSF of 1,000 km
Lee, Seong-Real ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 50~58
In this paper, the optimum position of optical phase conjugator (OPC) and the optimal dispersion coefficients of fiber sections in
Gbps WDM system with non zero - dispersion shifted fiber (NZ-DSF) of 1,000 km are induced, in order to expand the availability of mid-span spectral inversion (MSSI) technique in long-haul multi-channel transmission systems. It is confirmed that the compensation degrees of overall WDM channels are more improved by applying the induced optimal parameters into WDM system than those in WDM system with the conventional MSSI. So it is expected that the proposed optimal parameters should alternate with the forming method of the symmetrical distributions of optical power and local dispersion with respect to OPC, which generate a serious problem in the applying OPC into multi-channels WDM system if it is not formed. It will be possible to realize the flexible system design by applying the methods proposed in this paper into the real WDM system with OPC.
Grid Pattern Segmentation Using High Pass Filter
Joo, Ki-See ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 59~63
In this paper, an image segmentation algorithm is described to extract both the contour line and the inner grid patterns of body in case of ambiguous environment. The binary method using a threshold is used to extract image boundary. To reduce image noise, the
hybrid high pass filter adjusted for applying 3D information extraction of complicated shape object is proposed. This hybrid high pass filter algorithm can be applied to extract complicated shape object such as 3D body shape, CAD system, and factory automation since the processing time for image denoising is shorter than the conventional methods.
Design of Circular Microstrip Patch 2×2 Array Antenna for S-band Applications
Ahn, Yong-Bok ; Choi, Byoung-Ha ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 64~71
In this paper, we have designed and fabricated microstrip antenna of S-band for the wireless LAN and the ISM. It array
circular patch antenna elements at plane instead of conventional rectangular patch antenna elements. It optimized to size calculated of single patch antenna. The radiation elements distance is array
. The fabricated circular patch antenna decreased 8% of size compared to the conventional rectangular patch antenna. In the E-plane, designed circular microstrip patch
array antenna gain is 12.7[dBi], half power beam width is
and in the H-plane, antenna gain is 12.1[dBi], half power beam width is
. Bandwidth is 250[MHz] (VSWR < 2).
Design of RFID Mobile Antenna by Using Parasitic Element
Woo, Duk-Jae ; Kim, Sung-Jin ; Kim, Sang-Su ; Kim, Yo-Sik ; Lee, Kwang-Jae ; Lee, Taek-Kyung ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 72~78
In this paper, the wide-band monopole antenna with a parasitic element on the ground plane for application in Cellular, GSM and RFID mobile terminals such as the mobile phone or Personal Digital Assistant(PDA) phone is presented. The VSWR of the designed antenna is 2:1 over the frequency range of 820 MHz to 1040 MHz(bandwidth of 23.6 %). Therefore, the designed antenna can provide wide bandwidth covering the Cellular(824 MHz~894 MHz), RFID(908.5 MHz~914 MHz) and GSM(Tx:880 MHz~915 MHz, Rx:925 MHz~960 MHz). The radiation characteristics of the fabricated antenna were also studied. According to the measured radiation patterns, the maximum gains at 859 MHz and 911.25 MHz(center frequencies of the Cellualr and RFID bands) are -0.7 dBi and 0.16 dBi, respectively. The measured maximum gains of GSM bands are -0.48 dBi(897.5 MHz, the center frequency of Tx) and 1.69 dBi(942.5 MHz, the center frequency of Rx).
A Study on Method for Network Security Measurement
Sung, Kyung ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 79~86
In recent, one of the interesting research areas is about quality of network system. Therefore many research centers including ISO are preparing the measuring and evaluating method for network quality. This study will represent an evaluating model for network security based on checklist. In addition, we propose an measuring and evaluating method for network performance. The purpose of two studies is to present the evaluating procedure and method for measuring security of network on set workwill be identified and a measuring method and procedure will be proposed.
The V/UV Decision Algorithm for a Reduction of the Transmission Bit Rate in the CELP Vocoder
Min, So-Yeon ; Kim, Hyun-Chul ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 87~92
The conventional CELP(code excited linear prediction) type vocoder has no V/UV(voiced/unvoiced) classifier. So, the unvoiced speech is processed like the voiced speech. In this paper, to reduce the bit rate, we propose a new V/UV decision algorithm minimized error rate and preprocessing computation. This V/UV classifier use the LSP(line spectrum pair) parameter which is acquired spectrum analysis process in CELP vocoders. Applying this method to the 5.3kbps ACELP(algebraic code excited linear prediction) in the G.723.1, we can get the transmission bits rate reduction of 6% approximately without degradation of speech quality.
Implementation of Key Generation Algorithm for User Authentication and Encryption
Woo, Chan-Il ; Jeon, Se-Gil ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 93~98
The importance of information security is increasing by the rapid development of the communication network. So, cryptosystems are used to solve these problems and securities of cryptosystems are dependent on keys. In this paper, we propose a key generation method which is based on cryptographically secure MD5 hash function. The basic structure of the MD5 hash function features is a repetitive structure which is processed in a block unit of 512 bits from inputs of limited length and generates a fixed output of 128 bits. The security of proposed method is based on the hash function and the proposed method can be also utilized for authentication algorithm or data encryption algorithm.
A Interactive Virtual Reality for 3D Avatar Community Representation
Won, Yong-Tae ; Lee, Malrey ; Kwa, Hoon-Sung ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 99~104
On-line avatar community service requires natural representation of communication, emotional expression, and popular dances and various kinds of services. The space should be dynamic, and the interaction between the motions of avatars and the space is required. The avatars with their national, interesting, and various motions should be implemented togetherwith interaction with virtual spaces, in order to have competition in developing 3D avatars. It is expected for 3D avatars to be broadly applied for 3D shopping malls for e-commerce, cyber model houses, 3 D simulations, and 3D virtual reality game. Therefore, for one line 3D avatar community services, we try to provide the scheme for making interactive virtual spaces, together with 3D avatar animations.
Optimal Sub-bands Decision for Robust Watermarking
Kim, Yoon-Ho ; Kim, Tae-Gon ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 105~111
This paper is concerned with fuzzy inference-based optimal sub-bands decision scheme which is to be embedded the watermark. It concentrated not only on design of fuzzy inference algorithm but also on human visual parameters (HVP), such as contrast sensitivity, texture degree. In the first, such human visual parameters as contrast sensitivity, texture degree as well as statistical characteristics are involved to select the optimal coefficients region. Secondly, fuzzy if - then rule which can be able to adapt the wide variety of environments is developed. The performance of proposed approach is evaluated with respect to the imperceptibility and correctness of watermark. According to some experimental results, contrast sensitivity function is superior in smooth image. On the other hand, statistical characteristics provide good results in rough images.
The Design of the Security Protocol for Electronic Commerce Payment System
Lee, Sang-Duck ; Han, Seung-Jo ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 112~117
The Internet leads the transformation of the all-over social life with its radical diffusion and development. Moreover, it can be more focussed on the electronic commerce using the Internet - a new type of commerce, which is diffusion and developing. In the paper, we propose an electronic payment protocol with a network-type electronic-cash based on Public Key Infrastructure(PKI). The proposed protocol overcomes the problem of NetBill which deals with only contents and can't ensure anonymity. It also prevents illegal copy and distribution and insures the greatest safety by means of giving a certification number to the digital contents offered on the on-line.
Investigation of Secure Wireless Multihop Ad hoc Network
Lee, Sang-Duck ; Park, Jong-An ; Han, Seung-Jo ; Pyun, Jae-Young ;
The Journal of Advanced Navigation Technology, volume 11, issue 1, 2007, Pages 118~126
An ad hoc network is a system of wireless mobile nodes that dynamically self-organize in arbitrary and temporary network topologies allowing people and devices to internetwork without any preexisting communication infrastructure. Although ad hoc network is attractive solution, there are still some major flaws that prevent commercial growth. Security is one of these main barriers; ad hoc networks are known to be particularly vulnerable to security attack. It is difficult to establish a centralized key distribution center and a trusted certification authority to provide cryptographic keys and digital certificates to nodes. To prevent attacks in ad hoc routing protocols, many algorithms have been used. In this paper, we have depicted a secure framework for multipath routing in wireless multihop network, which is comprehensive solution for secure data forwarding in wireless multihop networks. With the simulation results, the proposed scheme is compared with existing source routing scheme.