Development and Validation of an Improved 5-DOF Aircraft Dynamic Model for Air Traffic Control Simulation
강지수 Jisoo Kang , 오혜주 Hyeju Oh , 최기영 Keeyoung Choi , 이학태 Hak-tae Lee
20(5) 387-393, 2016
강지수 Jisoo Kang , 오혜주 Hyeju Oh , 최기영 Keeyoung Choi , 이학태 Hak-tae Lee
DOI: JANT Vol.20(No.5) 387-393, 2016
To perform realistic air traffic control (ATC) simulation in various air traffic situations, an aircraft dynamic model that is accurate and efficient is required. In this research, an improved five degree of freedom (5-DOF) dynamic model with feedback control and guidance law is developed, which utilizes selected performance data and operational specifications from the base of aircraft data (BADA) and estimations using aircraft design techniques to improve the simulation fidelity. In addition, takeoff weight is estimated based on the aircraft type and flight plan to improve simulation accuracy. The dynamic model is validated by comparing the simulation results with recorded flight trajectories. An ATC simulation system using this 5-DOF model can be used for various ATC related research.
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Simulation of GNSS Spoofing Detection Method Using Encrypted Ranging Signal
소형민 Hyoungmin So
20(5) 394-400, 2016
소형민 Hyoungmin So
DOI: JANT Vol.20(No.5) 394-400, 2016
It is well known that the encrypted ranging signal, such as GPS P(Y) code, is immune to spoofing attack. However, in order for users to use the signal, there needs permission from the operator. And also there are many restrictions for use because of security issues. In this paper, a ground reference station equipped with high-gain directional antenna and a user receiver were simulated. In the reference station, the encrypted code can be demodulated from the high-gain signal. And then the code can be used to detect spoofing attack in the user receiver. This paper proposes the spoofing detection method using the encrypted signal and deals with simulation results.
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3-Dimensional Path Planning and Guidance for High Altitude Long Endurance UAV Including a Solar Power Model
오수헌 Su-hun Oh , 김갑동 Kap-dong Kim , 박준현 Jun-hyun Park
20(5) 401-407, 2016
오수헌 Su-hun Oh , 김갑동 Kap-dong Kim , 박준현 Jun-hyun Park
DOI: JANT Vol.20(No.5) 401-407, 2016
This paper introduces 3-dimensional path planning and guidance including power model for high altitude long endurance (HALE) UAV using solar energy. Dubins curve used in this paper has advantage of being directly available to apply path planning. However, most of the path planning problems using Dubins curve are defined in a two-dimensional plan. So, we used 3-dimensional Dubins path generation algorithm which was studied by Randal W. Beard. The aircraft model which used in this paper does not have an aileron. So we designed lateral controller by using a rudder. And then, we were conducted path tracking simulations by using a nonlinear path tracking algorithm. We generate examples according to altitude conditions. From the path tracking simulation results, we confirm that the path tracking is well on the flight path. Finally, we were modeling the power system of HALE UAVs and conducting path tracking simulation during 48hours. Modeling the amount of power generated by the solar cell through the calculation of the solar energy yield. And, we show the 48hours path tracking simulation results.
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Design and Implementation of Ship Energy Efficiency Monitoring System
김용대 Yong-dae Kim , 윤현규 Hyeon-kyu Yoon , 강남선 Nam-seon Kang
20(5) 408-416, 2016
김용대 Yong-dae Kim , 윤현규 Hyeon-kyu Yoon , 강남선 Nam-seon Kang
DOI: JANT Vol.20(No.5) 408-416, 2016
This study designed a ship energy efficiency monitoring system based on a ship application system that provides maritime services by utilizing data collected onboard, and a ship-land integration system for integrated management and exchange of maritime data. The ship energy efficiency monitoring system was developed as a Windows application program and designed to use file based EDI communications. Its main functions include route planning to minimize fuel consumption, monitoring of energy consumption and gas emissions, analysis of ship energy efficiency and other data analysis. The system has been successfully implemented in actual ships.
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Prediction on the Effect of Multi-Constellation SBAS by the Application of SDCM in Korea and Its Performance Evaluation
임철순 Cheol-soon Lim , 석효정 Hyo-jeong Seok , 황호연 Ho-yon Hwang , 박병운 Byungwoon Park
20(5) 417-424, 2016
임철순 Cheol-soon Lim , 석효정 Hyo-jeong Seok , 황호연 Ho-yon Hwang , 박병운 Byungwoon Park
DOI: JANT Vol.20(No.5) 417-424, 2016
Russia recently began broadcasting the SDCM signal in order to provide SBAS service for the civil aviation in the Russian territory using its own geostationary satellites. The service coverage of the SDCM geostationary satellite, LUCH-5A and LUCH-5B, includes Korea peninsula, where the test signal from the pseudo random number (PRN) 140 is received. This paper shows that the position accuracy at the Chulwon GNSS site is improved to 0.8749 m (horizontal) and 0.9589 mm (vertical) by applying the received SDCM message to the RINEX data. Considering that the SDCM augments both GPS and GLONASS, the performance of multi-constellation SBAS was compared to that of GPS-only SBAS, and APV-I availability was improved by decreasing the protection level about 30 %. From the results, we can expect that the mult-constellation SBAS can contribute to the performance enhancement of the future KASS.
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An Accuracy Analysis on the Broadcast Ephemeris and IGS RTS
김민규 Mingyu Kim , 김정래 Jeongrae Kim
20(5) 425-432, 2016
김민규 Mingyu Kim , 김정래 Jeongrae Kim
DOI: JANT Vol.20(No.5) 425-432, 2016
When user estimates user`s position, GPS positions can be obtained from the navigation message transmitted from the GPS. However, the broadcast ephemeris cannot be used in the applications required high-level accuracies because it can cause errors of several meters. To correct satellite positions and clocks, user can use RTS corrections provided by IGS. In this paper, the accuracy of broadcast and RTS corrections are analyzed by comparing with the IGS final for 3-months. The RTS errors are analyzed for each user`s locations and satellite blocks. The correlations between errors and shadow condition, and solar and geomagnetic activities are analyzed. The latency is applied to the RTS corrections, and these are extrapolated by polynomial. Then, the extrapolated RTS are compared with true RTS. The single-day performances of the PPP by broadcast ephemeris and RTS corrected ephemeris are analyzed. As a result, RTS 3D orbit and clock errors are 1/20 and 1/3 less than broadcast ephemeris errors. 3D positioning error of the RTS is 1/5 less than that of broadcast ephemeris.
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DGNSS-CP Performance Comparison of Each Observation Matrix Calculation Method
신동현 Dong-hyun Shin , 임철순 Cheol-soon Lim , 석효정 Hyo-jeong Seok , 윤동환 Dong-hwan Yoon , 박병운 Byungwoon Park
20(5) 433-439, 2016
신동현 Dong-hyun Shin , 임철순 Cheol-soon Lim , 석효정 Hyo-jeong Seok , 윤동환 Dong-hwan Yoon , 박병운 Byungwoon Park
DOI: JANT Vol.20(No.5) 433-439, 2016
Several low-cost global navigation satellite system (GNSS) receivers do not support general range-domain correction, and DGNSS-CP (differential GNSS) method had been suggested to solve this problem. It improves its position accuracy by projecting range-domain corrections to the position-domain and then differentiating the stand-alone position by the projected correction. To project the range-domain correction, line-of-sight vectors from the receiver to each satellite should be calculated. The line-of-sight vectors can be obtained from GNSS broadcast ephemeris data or satellite direction information, and this paper shows positioning performance for the two methods. Stand-alone positioning result provided from Septentrio PolaRx4 Pro receiver was used to show the difference. The satellite direction information can reduce the computing load for the DGNSS-CP by 1/15, even though its root mean square(RMS) of position error is bigger than that of ephemeris data by 0.1m.
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Adaptive Call Admission Control Based on Spectrum Holes Prediction in Cognitive Radio Networks
이진이 Jin-yi Lee
20(5) 440-445, 2016
이진이 Jin-yi Lee
DOI: JANT Vol.20(No.5) 440-445, 2016
There is a scheme where secondary users (SU) use predicted spectrum holes for primary users (PU) not to utilize for efficient utilization of the limited spectrum resources in cognitive radio networks. In this paper, we propose an adaptive call admission control framework that minimizes spectrum hopping call dropped probability (SHDP) for satisfying SU quality of service (QoS). The scheme is based on a call admission control (CAC), bandwidth prediction and adaptive bandwidth assignment. The prediction model predicts not only the number of spectrum holes, but requested bandwidth of SU spectrum hopping call, and then the CAC minimizes SHDP via an adaptive bandwidth assignment in resources not being enough for reservation. We bring Wiener prediction model to predict the resources. Simulations are conducted to compare the performance of proposed scheme with an existing, and show its ability of minimizing the SHDP.
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Flight Safety Assurance Technology for Rotary Aircraft through Optimization of HUMS Vibration Thresholds
전병규 Byung-kyu Jun , 정상규 Sang-gyu Jeong , 김영목 Young-mok Kim , 장인기 In-ki Chang
20(5) 446-452, 2016
전병규 Byung-kyu Jun , 정상규 Sang-gyu Jeong , 김영목 Young-mok Kim , 장인기 In-ki Chang
DOI: JANT Vol.20(No.5) 446-452, 2016
The aircraft has to be considered for safety very importantly because of peculiarity of flight in the air, so it should be retained through proper inspection and maintenance not only in production phase but also in operating phase. Recently, it is using the latest technology as engineering approach not depending on human factor to determine on maintenance needs, and domestic production rotary aircraft also has the health & usage monitoring system to measure and to monitor major components. However, continued vibration exceedance phenomenon occurred in production and operation phase because of inappropriate thresholds, and it confirmed as false alarm which is not necessary to repair. In this paper, it is described that operational concept of HUMS, and especially it contains a study result for efficiency of aircraft operation and ultimately the improvement of flight safety by optimizing HUMS thresholds to determine efficiently necessity of maintenance under limited conditions and by establishing inspection/maintenance procedures when the re-designated thresholds exceedance occurred.
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Design and Implementation of Time Synchronizer for Advanced ZigBee Systems
황현수 Hyunsu Hwang , 정용철 Yongcheol Jung , 정윤호 Yunho Jung
20(5) 453-461, 2016
황현수 Hyunsu Hwang , 정용철 Yongcheol Jung , 정윤호 Yunho Jung
DOI: JANT Vol.20(No.5) 453-461, 2016
Recently, with the growth of various sensor applications, the need of wireless communication systems which can support variable data rate is increasing. Therefore, advanced ZigBee (AZB) systems that support the various data rate under 250 kbps are proposed. However, the preamble structure for AZB systems causes the complexity increase of time synchronization circuits. In this paper, we propose preamble structure and time synchronization algorithm which can solve the problem of the complexity increase of time synchronization circuits. Implementation results show that the proposed time synchronizer for AZB systems include the logic slices of 6.92 k and, which are reduced at the rate of 62.3% compared with existing architecture.
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Dispersion-managed Optical Links with the Ascending or Descending of SMF Lengths and RDPS as the Fiber Span is Increased
이성렬 Seong-real Lee
20(5) 462-467, 2016
이성렬 Seong-real Lee
DOI: JANT Vol.20(No.5) 462-467, 2016
Dispersion management (DM) combining with mid-spans spectral inversion (MSSI) is one of the various techniques compensating for the distorted optical signals. For the flexible implementation of this configured link, the compensation characteristics in the optical link with artificial distribution of the gradually ascending and descending of single mode fiber (SMF)`s lengths and residual dispersion per span (RDPS) as the number of fiber spans are assessed as a function of the control positions of net residual dispersion (NRD). It is confirmed that the best compensation is obtained by distributing gradually ascending or descending of SMF`s lengths and RDPS capable to place NRD control position at fiber span, in which optical pulse width is most narrow.
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Process Improvement through Earphones Function Test Device Development
김완태 Wan-tae Kim , 이상구 Sang-gu Lee , 김현식 Hyun-sik Kim
20(5) 468-474, 2016
김완태 Wan-tae Kim , 이상구 Sang-gu Lee , 김현식 Hyun-sik Kim
DOI: JANT Vol.20(No.5) 468-474, 2016
Recently with smartphones and tablets, personal earphones have been using to utilize a wide range of multimedia services. Especially smartphones sold domestically provide earphones as necessaries. As a life style listening to music through smartphones and tablets has been spread widely, there has been in increasing demand of earphones necessary for enjoying music anytime and anywhere. This paper has simplified the complex performance test processes to inspect defective products when producing a large amount of earphonesand has improved the existing performance test processes to reduce the costs and time for the performance test of earphones. In this paper, the improved performance test processes through developing the performance test equipment of earphones can reduce the performance test inspectors, cut down the performance test time, and increase the daily amount of the performance test.
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Stability Condition for Discrete Interval Time-varying System with Time-varying Delay Time
한형석 Hyung-seok Han
20(5) 475-481, 2016
한형석 Hyung-seok Han
DOI: JANT Vol.20(No.5) 475-481, 2016
In this paper, the new stability condition of linear discrete interval time-varying systems with time-varying delay time is proposed. The considered system has interval time-varying system matrices for both non-delayed and delayed states with time-varying delay time within given interval values. The proposed condition is derived by using Lyapunov stability theory and expressed by very simple inequality. The restricted stability issue on the interval time-invariant system is expanded to interval time-varying system and a powerful stability condition which is more comprehensive than the previous is proposed. As a results, it is possible to avoid the introduction of complex linear matrix inequality (LMI) or upper solution bound of Lyapunov equation in the derivation of sufficient condition. Also, it is shown that the proposed result can include the many existing stability conditions in the previous literatures. A numerical example in the pe revious works is modified to more general interval system and shows the expandability and effectiveness of the new stability condition.
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Development and Performance Estimation of Wide-ranged Fine Current Module for NPP Instrumentation
김종호 Jong-ho Kim , 장홍기 Hong-ki Chang , 최규식 Gyu-shik Che
20(5) 482-489, 2016
김종호 Jong-ho Kim , 장홍기 Hong-ki Chang , 최규식 Gyu-shik Che
DOI: JANT Vol.20(No.5) 482-489, 2016
Detection of gamma ray can be available using optical fiber scintillator under radiation environment. It monitors the transfer energies of these ions by photodiodes and then convertes into currents. The module which converts those currents into voltages and processes signals is named fine current module TIA, and it is essentially important to convert currents into voltages with high linearity. We have studied and developed the TIA, improving converting linearity and minimizing noises and off-set voltages. Also, we have made efforts to develop precise and accurate current module in compliance with concerned requirements. First of all, we established developing theory, developed related circuits, and then made the current module. And, we confirmed its stability and linearity to be more excellent than any other equipment proposed by other references. We tested the developed fine current modules in the real radiation environment under authorized supervising, confirmed them to meet related requirements.
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Design of Microstrip-fed Dual Band Monopole Antenna for WLAN
남주열 Ju-yeol Nam , 이영순 Young-soon Lee
20(5) 490-495, 2016
남주열 Ju-yeol Nam , 이영순 Young-soon Lee
DOI: JANT Vol.20(No.5) 490-495, 2016
In the present study, a microstrip-fed monopole antenna is proposed for wireless local area network (WLAN) operations which cover dual band of 2.4 GHz (2.4 ~ 2.484 GHz) and 5 GHz (5.15 ~ 5.825 GHz). In order to obtain its compact structure and good omnidirectional radiation patterns, a modified inverted L-shaped slot separated from ground for impedance matching in 5 GHz band is etched on 2.4 GHz printed monopole antenna. The proposed antenna is designed and fabricated on a FR4 substrate with dielectric constant 4.3, thickness of 1.6 ㎜, and size of 30 × 45 ㎟. The measured impedance bandwidths (|S11| ≤ -10 dB) of fabricated antenna are 270 MHz (2.22 ~ 2.48 GHz) in 2.4 GHz band and 890 MHz (5.08 ~ 5.97 GHz) in 5 GHz band respectively. In particular, high gain of more than about 4 dBi and good omnidirectional radiation patterns have been observed over the entire frequency band of interest.
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A GUI-based the Recognition System for Measured Values of Digital Instrument in the Industrial Site
전민식 Min-sik Jeon , 고봉진 Bong-jin Ko
20(5) 496-502, 2016
전민식 Min-sik Jeon , 고봉진 Bong-jin Ko
DOI: JANT Vol.20(No.5) 496-502, 2016
In this paper, we proposed and implemented a GUI-based system to recognize and record measured values of digital instruments in the industrial site through image processing. Unlike the existing vehicle license plate recognition system, the measured values of the measuring instrument are displayed on the LCD screen as digital numbers. So, the proposed system considers the decimal point, a negative sign, light reflected by LCD protective glass, and various disturbance factors. We used blob-labeling technique to recognize the numbers displayed on the LCD screen, the recognized number images were determined as certain numbers through the template matching, and recognized values were recorded in the storage device with measurement time. Therefore, the proposed system in this paper would reduce the burden of writing when recording the measured values of the inside/outside diameter or height of the product in the industrial site, so effective and errorless process management in production process is possible by preventing errors in recording measurements when written by hand.
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