Aviation, Space and Ocean : Allocation of Design Assurance Level for KASS Based on International Standards
배동환 Dong Hwan Bae
20(1) 1-7, 2016
배동환 Dong Hwan Bae
DOI: JANT Vol.20(No.1) 1-7, 2016
Since 2014, MOLIT (Ministry of Land, Infrastructure, and Transport) is carrying out a KASS project to develop and construct Korean SBAS. KASS can cause damage of human & properties if it has some problem during operation. Therefore, system safety assessment for KASS development is very important. Principal point of system safety assessment is the allocation of DAL(design assurance level) based on the hazard identification and classification. In this parer, the author conducts the allocation of DAL for KASS & its sub-systems based on the international standard(SAE ARP4761), which suggests a best practice of aviation system safety assessment. The result of this paper are the first step of system safety assessment, and can be used for further system safety assessment of KASS project.
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Aviation, Space and Ocean : Conceptual Design Analysis of Satellite Communication System for KASS
신천식 Cheon Sig Sin , 유문희 Moonhee You , 형창희 Chang Hee Hyoung , 이상욱 Sangguk Lee
20(1) 8-14, 2016
신천식 Cheon Sig Sin , 유문희 Moonhee You , 형창희 Chang Hee Hyoung , 이상욱 Sangguk Lee
DOI: JANT Vol.20(No.1) 8-14, 2016
High-level conceptual design analysis results of satellite communication system for Korea augmentation satellite system (KASS) satellite communication system, which is a part of KASS and consisted of KASS uplink Stations and two leased GEO is presented in this paper. We present major functions such as receiving correction and integrity message from central processing system, taking forward error correction for the message, modulating and up converting signal and conceptual design analysis for concepts for design process, GEO precise orbit determination for GEO ranging that is additional function, and clock steering for synchronization of clocks between GEO and GPS satellites. In addition to these, KASS requires 2.2 MHz for SBAS Augmentation service and 18.5 MHz for Geo-ranging service as minimum bandwidths as a results of service performance analysis of GEO ranging with respect to navigation payload(transponder) RF bandwidth is presented. These analysis results will be fed into KASS communication system design by carrying out final analysis after determining two GEOs and sites of KASS uplink stations.
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Aviation, Space and Ocean : An Analysis on the Technical Regulation for A-SMGCS in Korea
최승훈 Seung Hoon Choi , 최연철 Youn Chul Choi , 홍슴범 Seung Boem Hong
20(1) 15-22, 2016
최승훈 Seung Hoon Choi , 최연철 Youn Chul Choi , 홍슴범 Seung Boem Hong
DOI: JANT Vol.20(No.1) 15-22, 2016
The A-SMGCS is a modular system defined in the ICAO manual on advanced surface movement guidance and control systems. Such systems aim to maintain the declared surface movement rate under all weather conditions while maintaining the required level of safety. In this paper, we find out the details and 14 modules``specific features that developing Level IV A-SMGCS in Korea. Also we figure out relation domestic regulations as SMGCS manual & visual aids manual in Korea and research foreign cases such as defined ICAO 9830 manual, EUROCONTROL``s project ``EMMA2`` document, and FAA advisory circular-150 manual. It will be used as analysis data that can be applied to the undefined A-SMGCS in Korea technical regulation.
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Navogation : Accuracy Verification of the SBAS Tropospheric Delay Correction Model for the Korean Region
김동욱 Dong Uk Kim , 한덕화 Deok Hwa Han , 기창돈 Chang Don Kee , 이철수 Chul Soo Lee , 이충희 Choong Hee Lee
20(1) 23-28, 2016
김동욱 Dong Uk Kim , 한덕화 Deok Hwa Han , 기창돈 Chang Don Kee , 이철수 Chul Soo Lee , 이충희 Choong Hee Lee
DOI: JANT Vol.20(No.1) 23-28, 2016
In this paper, we verified accuracy of the satellite based augmentation system (SBAS) tropospheric delay correction model for the Korean region. We employed the precise data of the tropospheric zenith path delay (ZPD) which is provided by the international GNSS service (IGS). In addition, we compared the verification results with that of the Saastamoinen model and the Hopfield model. Consequently, the bias residual error of the SBAS tropospheric delay correction model is about 50 mm, whereas the Saastamoinen model and the Hopfield model are more accurate. This residual error by the tropospheric delay model can affect the SBAS user position accuracy, but there is no problem in SBAS accuracy requirement. If we modified the meteorological parameters for SBAS tropospheric model to appropriate in Korean weather environment, we can provide better SBAS service to the Korean user.
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Navogation : Improving GPS Vertical Error Using Barometric Altimeter
김라우 La Woo Kim , 최광호 Kwang Ho Choi , 임준후 Joon Hoo Lim , 유원재 Won Jae Yoo , 이형근 Hyung Keun Lee
20(1) 29-36, 2016
김라우 La Woo Kim , 최광호 Kwang Ho Choi , 임준후 Joon Hoo Lim , 유원재 Won Jae Yoo , 이형근 Hyung Keun Lee
DOI: JANT Vol.20(No.1) 29-36, 2016
Accuracy of GPS (global positioning system) deteriorates dramatically or positioning is impossible in urban area occasionally since high-rise buildings and elevated roads make the reception of navigation signal very difficult so that number of visible satellites decreases. In these cases, vertical error usually becomes much larger than the horizontal error due to the intrinsic geometry of GPS satellites. To obtain more accurate and reliable height information, this paper proposes a hybrid method that combines GPS and a low-cost barometric altimeter. In the proposed method, the sea-level pressure and the sea-surface temperature are applied to the output of the altimeter. Next, the difference between the ellipsoid and the geoid is compensated. Finally, a simple Kalman filter combines the compensated barometric altitude and the GPS height. By static and car experiments, performance of the proposed method is evaluated. By the experiment results, it can be seen that the proposed method improves the altitude accuracy considerably.
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Navogation : Alternative Positioning, Navigation, and Timing Applicable to Domestic PBN Implementation
김무근 Mu Geun Kim , 강자영 Ja Young Kang , 장재호 Jae Ho Chang
20(1) 37-44, 2016
김무근 Mu Geun Kim , 강자영 Ja Young Kang , 장재호 Jae Ho Chang
DOI: JANT Vol.20(No.1) 37-44, 2016
Republic of Korea has established its performance-based navigation (PBN) implementation plan in 2010 for ensuring a smooth transition to PBN operations and relevant new flight procedures are being developed in accordance with the roadmap. Various Navigation aids (NAVAIDs) like global navigation satellite systems (GNSS), distance measuring equipment (DME), VHF omnidirectional range (VOR), inertial navigation system (INS) are used to support PBN procedures. Among them, GNSS would play a central role in PBN implementation. However, vulnerability of satellite navigation signals to artificial and natural interferences has been discovered and various alternative positioning, navigation and timing (APNT) technologies are under development in many countries. In this paper, we study whether continuous PBN operations can be achievable without GNSS signals. As a result, it shows that some of the domestic airports require the construction of APNT in the approach area.
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Aviation Communication Technique : Methodology of Interference Analysis Between TACAN/DME Beacons and Ground-based Link-16 Terminals
서경환 Kyoung Whoan Suh
20(1) 45-52, 2016
서경환 Kyoung Whoan Suh
DOI: JANT Vol.20(No.1) 45-52, 2016
In this paper, the method of interference analysis and its simulation have been suggested for the frequency sharing between aeronautical radio navigation systems and Link-16 platforms. In order to get the criteria for interoperability, the algorithm of interference analysis and protection ratio are derived to assure frequency sharing. Also the receiving power of wireless system has been illustrated with the help of radio propagation model of ITU-R Rec. P.1546 in VHF-UHF band. Finally the required receiving power or separation distance between DME/TACAN beacons and Link-16 ground station terminals has been considered based on system link budget in terms of evaluating interoperability as well as actual applications. As a result, if the suggested interference analysis and test set-up are applied to the field trial, it will lead to easy means to make a decision on interoperability over the existing incumbent systems.
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Aviation Communication Technique : Quadratic Kalman Filter Object Tracking with Moving Pictures
박선배 Sun Bae Park , 유도식 Do Sik Yoo
20(1) 53-58, 2016
박선배 Sun Bae Park , 유도식 Do Sik Yoo
DOI: JANT Vol.20(No.1) 53-58, 2016
In this paper, we propose a novel quadratic Kalman filter based object tracking algorithm using moving pictures. Quadratic Kalman filter, which is introduced recently, has not yet been applied to the problem of 3-dimensional (3-D) object tracking. Since the mapping of a position in 2-D moving pictures into a 3-D world involves non-linear transformation, appropriate algorithm must be chosen for object tracking. In this situation, the quadratic Kalman filter can achieve better accuracy than extended Kalman filter. Under the same conditions, we compare extended Kalman filter, unscented Kalman filter and sequential importance resampling particle filter together with the proposed scheme. In conculsion, the proposed scheme decreases the divergence rate by half compared with the scheme based on extended Kalman filter and improves the accuracy by about 1% in comparison with the one based on unscented Kalman filter.
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Basic Technique for Navigation and Aviation : Unequal Dualband Wilkinson Divider Using CPW and Shunt Connected Open Stub Transmission Lines
권상근 Sang Keun Kwon , 김영 Young Kim , 윤영철 Young Chul Yoon
20(1) 59-64, 2016
권상근 Sang Keun Kwon , 김영 Young Kim , 윤영철 Young Chul Yoon
DOI: JANT Vol.20(No.1) 59-64, 2016
This paper presents a high dividing ratio unequal dualband divider using coplanar waveguide (CPW) and shunt connected open stub transmission lines. In order to implement transmission lines for a dualband divider using design equations, the low impedance lines of divider can be realized a shunt connected open stub transmission line. Also, the high impedance lines are realized by CPW transmission lines. To certify the validity of an unequal dualband divider using CPW and shunt connected open stub transmission lines, the 10:1 unequal dualband divider is implemented at operating frequency of 1 and 2 GHz. Good experimental performance at each frequency are obtained, which are in good agreement with the simulated results.
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Basic Technique for Navigation and Aviation : Design of Extendable BCD-EXCESS 3 Code Convertor Using Quantum-Dot Cellular Automata
유영원 Young Won You , 전준철 Jun Cheol Jeon
20(1) 65-71, 2016
유영원 Young Won You , 전준철 Jun Cheol Jeon
DOI: JANT Vol.20(No.1) 65-71, 2016
Quantum-dot cellular automata (QCA) consists of nano-scale cells and demands very low power consumption so that it is one of the alternative technologies that can overcome the limits of scaling CMOS technologies. Typical BCD-EXCESS 3 code converters using QCA have not considered the scalability so that the architectures are not suitable for a large scale circuit design. Thus, we design a BCD-EXCESS 3 code converter with scalability using QCADesigner and verify the effectiveness by simulation. Our structure have reduced 32 gates and 7% of garbage space rate compare with typical URG BCD-EXCESS 3 code converter. Also, 1 clock is only needed for circuit expansion of our structure though typical QCA BCD-EXCESS 3 code converter demands 7 clocks.
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Basic Technique for Navigation and Aviation : Analysis of the Hashing and Encryption Algorithms Applied to the Linux
배유미 Yu Mi Bae , 정성재 Sung Jae Jung , 소우영 Woo Young Soh
20(1) 72-78, 2016
배유미 Yu Mi Bae , 정성재 Sung Jae Jung , 소우영 Woo Young Soh
DOI: JANT Vol.20(No.1) 72-78, 2016
MD-5 has been the hash algorithm to encrypt the user``s password on Linux from the beginning. Recently the more reliable password management was demanded and SHA-512 algorithm became the hash algorithm on the recent Enterprise Linux which is more reliable than MD-5. This paper researching the characteristics of the hashing and encryption algorithms and find out about Linux User information management. Based on this analysis, and analysis of the security of the hashing algorithm is applied to the user password. In addition, analyzes the cases used hash algorithm applied to the validation of Open Source Software file, such as Apache, PHP, MySQL. Finally, by analyzing the security tool John The Ripper this paper suggests the enhanced security with the administrative management of passwords.
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Basic Technique for Navigation and Aviation : General Web Cache Implementation Using NIO
이철희 Chul Hui Lee , 신용현 Yong Hyeon Shin
20(1) 79-85, 2016
이철희 Chul Hui Lee , 신용현 Yong Hyeon Shin
DOI: JANT Vol.20(No.1) 79-85, 2016
Network traffic is increased rapidly, due to mobile and social network, such as smartphones and facebook, in recent web environment. In this paper, we improved web response time of existing system using direct buffer of NIO and DMA. This solved the disadvantage of JAVA, such as CPU performance reduction due to the blocking of I/O, garbage collection of buffer. Key values circulated many data due to priority change put on a hash map operated easily and apply a priority modification algorithm. Large response data is separated and stored at a fast direct buffer and improved performance. This paper showed that the proposed method using NIO was much improved performance, in many test situations of cache hit and cache miss.
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Aviation Communication Technique : Developed of Smart Phone Charge System and Data Analysis for Efficient Solar Module Arrangement
장원창 Won Chang Jang , 전민호 Min Ho Jeon , 이명의 Myung Eui Lee
20(1) 86-92, 2016
장원창 Won Chang Jang , 전민호 Min Ho Jeon , 이명의 Myung Eui Lee
DOI: JANT Vol.20(No.1) 86-92, 2016
Recently, solar module is installed in crowded areas to offers services so that people can charge their smartphones or tablets. However, the burden in terms of cost is high to install in areas where utilization ratio is low and installation is difficult in limited spaces. In this paper, a system for collecting and providing the optical power is proposed from the analysis about the person that receives service in each area using the real-time data provided by the state and collected from the actual environment as well as considering the waiting time and the solar charging time in different environments. As a result, This study shows that charge was not delayed since collecting power exceeds charging power. Smartphone was fully charged in ninety-five minutes. we confirmed that with one smartphone, it can be charged a approximately fifty percent of the battery in between ten to twenty minutes, with multiple units they can be charged a approximately twenty percent of the battery in between ten to twenty minutes.
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Aviation Communication Technique : Patch Antenna for MOB Attached on Safety Helmet
김재원 Jae Won Kim , 양규식 Gyusik Yang
20(1) 93-98, 2016
김재원 Jae Won Kim , 양규식 Gyusik Yang
DOI: JANT Vol.20(No.1) 93-98, 2016
The purpose of this study is to design for MOB antenna attached on safety helmet using microstrip patch antenna. The patch antenna is fabricated in 0.2 mm FR-4 substrate with 64×64 mm size. The proposed antenna is based on a slot-ring design which cover Inmarsat (1.52 ~ 1.65 GHz) and GPS (1.575 GHz) frequency band. To obtain the optimized parameters, HFSS simulator is used, and antenna is designed by optimized parameters. After antenna was etched, SMA connector was attached to the microstrip feeding line and the result between antenna simulation and measurement was analyzed. Proposed antenna is satisfied the -10 dB bandwidth requirement while simultaneously covering the 1.53 ~ 1.65 GHz.
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Aviation Communication Technique : Design of Wearable LED Display Control System Using BLE
황홍택 Hong Taek Hwang
20(1) 99-106, 2016
황홍택 Hong Taek Hwang
DOI: JANT Vol.20(No.1) 99-106, 2016
Wearable display market is a consistently growing field to handle a smart device with ease. Wearable display is an efficient device that can show the information to the user. In this paper, propose the scheme of a wearable display using LED and implement it including controlling remotely with BLE. Traditional outdoor LED display requires the dedicated controller and its software. Therefore, to control those LED display, it should implement a driver and its own way of communication. The proposed method is to ensure the independence and extensibility by separating driver module and communication module for controlling LED display. In addition, by adopting a short-range communication with Bluetooth 4.0 and a LED driver with low-power technology, it can be showed to control system configuration and display with a smart device.
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