Software Design and Verification Method of Flight Data Recorder for Unmanned Aerial Vehicle
양서희 Seo-hee Yang
24(3) 163-172, 2020
양서희 Seo-hee Yang
DOI: JANT Vol.24(No.3) 163-172, 2020
Flight data recorder (FDR) for accident investigation is required to comply with EUROCAE(ED-112) standard so that flight data can be restored when exposed to extreme conditions due to aircraft crash. Since the ED-112 standard defines the general requirements for all aircraft, it is essential to analyze detailed requirements for FDR software to apply appropriate requirements selectively according to the configuration and operation concept of a specific aircraft. In this paper, the software requirements applicable to unmanned aircraft will be analyzed and the FDR software design will be proposed. Also, a software verification method for each requirement will be presented to verify that the implemented software is designed to satisfy all requirements.
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A Research of Passengers’ Perception on Benefit to Repurchase Intention through Price Reliability: Focusing on Comparing National Carrier and Foreign Carrier between Incheon-Dubai Air Route
이근영 Gun-young Lee , 김수정 Soo-jung Kim , 장지승 Ji-seung Jang
24(3) 173-183, 2020
이근영 Gun-young Lee , 김수정 Soo-jung Kim , 장지승 Ji-seung Jang
DOI: JANT Vol.24(No.3) 173-183, 2020
This research focused on such a passenger sample that used to fly between Incheon int’l airport(ICN) and Dubai int’l airport(DXB) using either a national carrier or gulf carriers because the route between ICN and DXB is one of the international air routes with the toughest competition under the global pressure of open air transport market. Based on the results from the empirical research, this paper proposed a competitive advantage which a national carrier must have to cope with global competition under the open sky policies and implications for sustainable strategies of them. National carrier passengers perceived product benefits had a significant positive effect on price reliability in spite of lower price competitiveness. Following the empirical analysis results, it was proven a national carrier should try to improve product benefit sought by passengers to maintain sustainable competitive advantage in the market against foreign airlines.
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Event-Driven Modeling and Simulation Method Applicable to Avionics System Integration Laboratory
신주철 Ju-chul Shin , 서민기 Min-gi Seo , 조연제 Yeon-je Cho , 백경훈 Gyong-hoon Baek , 김성우 Seong-woo Kim
24(3) 184-191, 2020
신주철 Ju-chul Shin , 서민기 Min-gi Seo , 조연제 Yeon-je Cho , 백경훈 Gyong-hoon Baek , 김성우 Seong-woo Kim
DOI: JANT Vol.24(No.3) 184-191, 2020
Avionics System Integration Laboratory is the integrated test environment for integration and verification of avionics systems. When real equipment can not be used in the laboratory for various reasons, software models should be needed. Because there hasn’t been any standardized method for the models so that it is difficult to reuse the developed models, the need for a framework to develop the avionics software models was emerged. We adopted DEVS(discrete event system specification) formalism as the standardized modeling method for the avionics software models. Due to DEVS formalism is based on event-driven algorithm, it doesn't accord a legacy system which has sequential and periodic algorithms. In this paper, we propose real-time event-driven modeling and simulation method for SIL to overcome these restrictions and to maximize reusability of avionics models through the analysis of the characteristics and the limitations of avionics models.
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Algorithm on Detection and Measurement for Proximity Object based on the LiDAR Sensor
정종택 Jong-teak Jeong , 최조천 Jo-cheon Choi
24(3) 192-197, 2020
정종택 Jong-teak Jeong , 최조천 Jo-cheon Choi
DOI: JANT Vol.24(No.3) 192-197, 2020
Recently, the technologies related to autonomous drive has studying the goal for safe operation and prevent accidents of vehicles. There is radar and camera technologies has used to detect obstacles in these autonomous vehicle research. Now a day, the method for using LiDAR sensor has considering to detect nearby objects and accurately measure the separation distance in the autonomous navigation. It is calculates the distance by recognizing the time differences between the reflected beams and it allows precise distance measurements. But it also has the disadvantage that the recognition rate of object in the atmospheric environment can be reduced. In this paper, point cloud data by triangular functions and Line Regression model are used to implement measurement algorithm, that has improved detecting objects in real time and reduce the error of measuring separation distances based on improved reliability of raw data from LiDAR sensor. It has verified that the range of object detection errors can be improved by using the Python imaging library.
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A EM-Log Aided Navigation Filter Design for Maritime Environment
조민수 Minsu Jo
24(3) 198-204, 2020
조민수 Minsu Jo
DOI: JANT Vol.24(No.3) 198-204, 2020
This paper designs a electromagnetic-log (EM-Log) aided navigation filter for maritime environment without global navigation satellite system (GNSS). When navigation is performed for a long time, Inertial navigation system (INS)’s error gradually diverges. Therefore, an integrated navigation method is used to solve this problem. EM-Log sensor measures the velocity of the vehicle. However, since the measured velocity from EM-Log contains the speed of the sea current, the aided navigation filter is required to estimate the sea current. This paper proposes a single model filter and interacting multiple (IMM) model filter methods to estimate the sea current and analyzes the influence of the sea current model on the filter. The performance of the designed aided navigation filter is verified using a simulation and the improvement rate of the filter compared to the pure navigation is analyzed. The performance of single model filter is improved when the sea current model is correct. However, when the sea current model is incorrect, the performance decreases. On the other hands, IMM model filter methods show the stable performance compared to the single model.
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Validation on Usability of Time Domain Reflectometer for Identifying Defected Aircraft Wiring
김수웅 Su-woong Kim , 이장룡 Jang-ryong Lee
24(3) 205-211, 2020
김수웅 Su-woong Kim , 이장룡 Jang-ryong Lee
DOI: JANT Vol.24(No.3) 205-211, 2020
Wiring defect is a major concern for safe aircraft operations. However, troubleshooting process of a wiring defect is very difficult due to extensive and complex wiring system and installed location. Recently, time domain reflectometer (TDR) equipment that enables effective defected wiring troubleshooting has been introduced. Unfortunately, TDRs have not practically adopted by most of airlines’ maintenance departments because the effectiveness and usefulness of TDRs have not been verified. This study was conducted to verify if TDRs can identify the location and type of defected aircraft wiring, and whether they can be applied for troubleshooting purposes. Experimental plan was established by using various wires and connections applied to actual aircraft and the observed results were compared with the TDR operation guide. The usability of the TDR in actual aircraft wiring defect detection may be acceptable as the experimental results showed similar results to the TDR operation guide.
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Coverage Test of WAVE-LTE Hybrid V2X Communication System
윤상훈 Sang-hun Yoon , 임기택 Ki-taeg Lim , 곽재민 Jae-min Kwak
24(3) 212-217, 2020
윤상훈 Sang-hun Yoon , 임기택 Ki-taeg Lim , 곽재민 Jae-min Kwak
DOI: JANT Vol.24(No.3) 212-217, 2020
Recently, with the interest in the 4th industrial revolution, the demand for autonomous driving technology is increasing. V2X communication technology is a core technology for autonomous vehicles that exchanges information with objects such as vehicles, infrastructure, networks, and pedestrians through wired and wireless networks. In this paper, we present the results of the hybrid V2X communication system, which is a hybrid design of WAVE and LTE, and the coverage test to confirm the performance of the system. Through coverage measurement, we show that the hybrid V2X communication performance is superior to the existing LTE or WAVE single communication system in communication coverage, so it can be effectively applied to autonomous driving services.
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A Proposal of Simultaneous Acquisition Performance Test Method for Telemetry System
박유광 Yu-kwang Park , 이운문 Woon-moon Lee , 김복기 Bok-ki Kim
24(3) 218-223, 2020
박유광 Yu-kwang Park , 이운문 Woon-moon Lee , 김복기 Bok-ki Kim
DOI: JANT Vol.24(No.3) 218-223, 2020
There are communication methods that guarantees real-time and method of performing the simultaneous acquisition through the synchronized multi-channels to improve the reliability of the telemetry system. Such synchronized systems need to be verified to confirm the simultaneous measurement performance of channels. In this paper, we propose a method to measure the time difference between synchronized channels in a telemetry system through simultaneous acquisition performance test. The simulation signal is applied for measurement and the difference between the sampling period and the simulation signal period is defined as the concept of time resolution. The principle of checking the measurement time difference between channels through time resolution was explained. In addition, the proposed principle was verified through simulation in the situation when measurement time difference may occur. And a procedure for identifying a measurement time difference in an actual telemetry system is described.
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Design of Small Optical Tracker for Use in the Proving Ground
박상현 Sanghyun Park
24(3) 224-231, 2020
박상현 Sanghyun Park
DOI: JANT Vol.24(No.3) 224-231, 2020
An optical tracking plays an important role for measurement operation, as it is responsible for low altitude measurements that are difficult to obtain with radar systems. Since the existing optical tracking systems have not been developed in the proving ground itself so far, it is difficult to modify them to fit the environment of the proving ground. Also, they are designed as a vehicle-mounted type, so there is a limitation in selecting an optimal site. The in-house developed small optical tracking system is designed with a simple configuration to overcome these shortcomings and makes it possible for operators to operate the system at any place in the proving ground. In addition, there has been a need of developing small optical trackers by ourselves to be prepared for future research so that artificial intelligence (AI) can be applied to the optical tracking systems. In this paper, we described the design concept of the small optical tracker, the configuration of the components to implement the basic tracking function, and showed the results of the simulation to set the configuration of the equipment according to the characteristics of the flight targets.
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Compact Dual-Band Planar Antenna with GPS Band
조규필 Gyu-pil Cho , 신동기 Dong-gi Shin , 이영순 Young-soon Lee
24(3) 232-237, 2020
조규필 Gyu-pil Cho , 신동기 Dong-gi Shin , 이영순 Young-soon Lee
DOI: JANT Vol.24(No.3) 232-237, 2020
In this paper, a compact microstrip-fed dual-band planar antenna for global positioning system (GPS) and mobile handset applications is presented. Dual operating frequency bands are achieved by an open end L-shaped slot and a bent rectangular slot. The proposed antenna is designed and fabricated on the FR4 substrate with dielectric constant of 4.3, thickness of 1.6 mm and size of 57 × 57 mm2. The measured impedance bandwidth (|S11|≤-10dB) of the fabricated antenna is 60 MHz(1550 ~ 1610 MHz) in the GPS band and 670 MHz (1690 ~ 2360 MHz) in the DCS / IMT-2000 band, covering the required bandwidths for GPS(1570 ~ 1580 MHz) and DCS / IMT-2000 (1710 ~ 2200 MHz) bands. In particular, it has been observed that antenna has a good omnidirectional radiation patterns as well as high gain of 2.36 dBi and its efficiency is more than 90 % over the entire frequency band of interest.
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How to Search and Evaluate Video Content for Online Learning
용성중 Sung-jung Yong , 문일영 Il-young Moon
24(3) 238-244, 2020
용성중 Sung-jung Yong , 문일영 Il-young Moon
DOI: JANT Vol.24(No.3) 238-244, 2020
The development and distribution rate of smartphones have progressed so rapidly that it is safe for the entire nation to use them in the smart age, and the use of smartphones has become an essential medium for the use of domestic media content, and many people are using various contents regardless of gender, age, or region. Recently, various media outlets have been consuming video content for online learning, indicating that learners utilize video content online for learning. In the previous research, satisfaction studies were conducted according to the type of content, and the improvement plan was necessary because no research was conducted on how to evaluate the learning content itself and provide it to learners. In this paper, we would like to propose a system through evaluation and review of learning content itself as a way to improve the way of providing video content for learning and quality learning content.
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