김태영 Tae Young Kim , 박배선 Bae-seon Park , 이현웅 Hywonwoong Lee , 이학태 Hak-tae Lee

DOI: JANT Vol.23(No.1) 1-7, 2019

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This study presents the development of a fast-time airport surface simulator. The simulator uses the output from a first-come first-served (FCFS) scheduler and has adopted one-dimensional dynamic model to simulate the movement of the aircraft on the surface. Higher collision risks situations in the airport surface traffic are analyzed to classify those situations into six cases. A conflict detection and resolution algorithm is implemented to maintain separation distance and to prevent deadlock. The simulator was tested with a scenario at the Incheon International Airport that contains 72 aircraft. Without the conflict detection and resolution, various conflict situations are identified. When the conflict detection and resolution algorithm is managing the traffic, it is confirmed that the conflicts are removed at the price of additional delays. In the conflict resolution algorithm, three prioritization strategies are implemented, and delayed aircraft count and average additional delays are compared. Prioritization based on remaining time or distance showed smaller total additional delay compared to choosing minimum delay priority for each situation.

이근영 Gun-young Lee , 손병욱 Byoung Wook Son , 박성식 Sung-sik Park

DOI: JANT Vol.23(No.1) 8-19, 2019

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Pilots have used checklist as a valuable tool to improve aviation safety and to reduce human error. A checklist however is too complex for a student pilot to use with less flight experience or time than a commercial pilot. It is agreed upon such complex checklist be a factor to threaten aviation safety for student pilots. This paper has focused on a checklist by dividing it into a couple of basic three flight procedures. Making exploratory case study of student pilots, researchers could analyze the correlation between checklist factors and those of human errors. First of all, it was necessary for student pilots to be educated professional knowledge regarding aircraft structures and engines to perform preflight inspection reducing human errors. Moreover it was recommended student pilots as well as maintenance crew confirm checklist together to enhance aviation safety.

백정선 Jeong-sun Beak , 이윤철 Yun-cheol Lee , 이영길 Yung-kil Lee

DOI: JANT Vol.23(No.1) 20-35, 2019

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In this article, we verified to influence on the performance through performance management system and public enterprise management evaluation implementation degree by the airport policy and leadership. Data collected from 533 employees of Incheon International Airport Corporation and Korea Airports Corporation. Sample extracted with a simple random sampling. Data analysis adopted structural equation modeling. The results of this research found that airport policy and leadership are the key variables influencing airport performance. This research verified a significant mediation effect on the public enterprise management evaluation implementation degree. Thus, this research assert that positive proposals for airport policy and insightful leadership must be taken. This paper explores new view in the public enterprise management evaluation research and offers practical help to researchers and practitioners in providing a direction for airport performance.

안진수 Jinsoo Ahn , 김백 Baik Kim , 김용호 Ronny Yongho Kim

DOI: JANT Vol.23(No.1) 30-37, 2019

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In this paper, a novel channel access scheme for the next-generation vehicle to anything (V2X) system based on IEEE 802.11p standard which is applied to recent connected car technologies is suggested and analyzed. The proposed scheme proposes a channel access method utilizing OFDMA multi-user transmission for IEEE 802.11p based system. In this paper, the authors examine geographical distance and network area performance of IEEE 802.11p system and the proposed scheme. Results of this research show that the proposed scheme is quite suitable for improving conventional V2X standards and systems. This paper also provides mathematical analysis and simulation results of the conventional IEEE 802.11p system and the proposed scheme.

차재영 Jae-young Cha , 황호연 Ho-yon Hwang

DOI: JANT Vol.23(No.1) 44-54, 2019

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In many countries, there are needs of new transportations to replace ground congestions due to growing number of cars. In addition, the increase in the number of cars held by economic growth will further increase traffic congestion in the future. To overcome this problem, many researches have been performed for personal air vehicle (PAV). In this study, the wing loading and the power-to-weight ratio that are major design parameters for the sizing of roadable PAVs were calculated for different kinds of airfoil and engine types. I.e., in the sizing process, the study was conducted to determine the design point using the graphs of wing loading, power-to-weight ratio, brake horse power, and fuel efficiency for the given mission profiles considering domestic environments and the FAR PART 23 which is the GA class aircraft certification standard. As a result of sizing, using diesel engine require high maximum take-off weight, wing area, and power compared to gasoline engine due to more engine weight.

김현국 Hyun-gook Kim , 박진태 Jin-tae Park , 최문혁 Moon-hyuk Choi , 문일영 Il-young Moon

DOI: JANT Vol.23(No.1) 55-60, 2019

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The web is one of the most intimate technologies in people's daily lives, and most of the time, people are sharing data on the web. Simple messenger, news, video, as well as various data are now spreading through the web. In addition, with the emergence of Web assembly technology, the programs that run in the existing native environment start to enter the domain of the Web, and the data shared by the Web is now getting wider and larger in terms of VR / AR contents and big data. Therefore, in this paper, we have studied how to effectively deliver web contents to users who use Web service by using service worker that can operate independently without being dependent on browser and cache API that can effectively store data in web browser.

손현중 Hyeon-joong Son , 최형식 Hyeung-sik Choi , 강진일 Jin-il Kang , 서주노 Joo-no Sur , 정성훈 Seong-hoon Jeong , 이재헌 Jaeheon Lee , 김서강 Seo-kang Kim

DOI: JANT Vol.23(No.1) 61-68, 2019

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Underwater wireless light communication system is quite necessary to retrieve recorded data from underwater devices or the black box without taking back it body. In this paper, a research on the light sensor technology in underwater wireless light communication under turbid sea was studied. A noise source under turbid sea for light communication was analysed, and a sensor system for light sensing using the reference light signal to remove the noises and to improve the output swing power was studied. Also, an underwater communication system was manufactured to validate the good performance of the development system, and using the system, the good performance of the developed system was validated through the light communication test in the tank containing the turbid sea water was presented.

여준호 Junho Yeo , 이종익 Jong-ig Lee

DOI: JANT Vol.23(No.1) 69-76, 2019

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In this paper, a design method for an enhanced-sensitivity microwave sensor based on microstrip defected ground structure was studied for the permittivity measurement of planar dielectric substrates. The proposed sensor was designed by modifying the ridge structure of an H-shaped aperture into the shape of a capacitor symbol. The sensitivity of the proposed sensor was compared with that of a conventional sensor based on a double-ring complementary split ring resonator(DR-CSRR). Two sensors were designed and fabricated on a 0.76-mm-thick RF-35 substrate so that the transmission coefficient would resonate at 1.5 GHz in the absence of the substrate under test. Five types of taconic substrates with a relative permittivity ranging from 2.17 to 10.2 were selected as the substrate under test. Experiment results show that the sensitivity of the proposed sensor, which is measured by the shift in the resonant frequency of the transmission coefficient, is 1.31 to 1.62 times higher than that of the conventional DR-CSRR-based sensor.

박성준 Sung-jun Park , 백중환 Joong-hwan Baek

DOI: JANT Vol.23(No.1) 77-83, 2019

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In this paper, we propose an object tracking algorithm based on color histogram and convolutional neural network model. In order to increase the tracking accuracy, we synthesize generic object tracking using regression network algorithm which is one of the convolutional neural network model-based tracking algorithms and a mean-shift tracking algorithm which is a color histogram-based algorithm. Both algorithms are classified through support vector machine and designed to select an algorithm with higher tracking accuracy. The mean-shift tracking algorithm tends to move the bounding box to a large range when the object tracking fails, thus we improve the accuracy by limiting the movement distance of the bounding box. Also, we improve the performance by initializing the tracking start positions of the two algorithms based on the average brightness and the histogram similarity. As a result, the overall accuracy of the proposed algorithm is 1.6% better than the existing generic object tracking using regression network algorithm.

신창교 Changkyo Shin , 권현석 Hyunseok Kwon , 박유림 Yurim Park , 김천곤 Chun-gon Kim

DOI: JANT Vol.23(No.1) 84-89, 2019

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This is a pilot study of machine learning based structural health monitoring system using flight data of composite aircraft. In this study, the most suitable machine learning algorithm for structural health monitoring was selected and dimensionality reduction method for application on the actual flight data was conducted. For these tasks, impact test on the cantilever beam with added mass, which is the simulation of damage in the aircraft wing structure was conducted and classification model for damage states (damage location and level) was trained. Through vibration test of cantilever beam with fiber bragg grating (FBG) sensor, data of normal and 12 damaged states were acquired, and the most suitable algorithm was selected through comparison between algorithms like tree, discriminant, support vector machine (SVM), kNN, ensemble. Besides, through neighborhood component analysis (NCA) feature selection, dimensionality reduction which is necessary to deal with high dimensional flight data was conducted. As a result, quadratic SVMs performed best with 98.7% for without NCA and 95.9% for with NCA. It is also shown that the application of NCA improved prediction speed, training time, and model memory.

권혁 Hyuk Kwon , 진경복 Kyoung-bog Jin , 오창헌 Chang-heon Oh

DOI: JANT Vol.23(No.1) 90-96, 2019

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LPWA is a cost-effective and time-saving technology with wide coverage. However, the LPWA is an ISM band that uses UHF radio waves, and its performance is very poor indoors because of its strong linearity. But, because of the possibility of achieving high performance compared to other communication in the room, this paper has studied the indoor communication performance by applying LoRa in LPWA technologies. After installing the data receiving module on the 4th floor, the transmission module was placed at the end of the building from the same floor to the 1st floor, and the data was collected. As a results, it installed on the 1st floor can be collected data with 98 ~ 99% probability, and the lowest RSSI is about -116dBm. Thus, considering the specification of LoRa with a maximum reception sensitivity -136dBm when the spreading factor is 12, the application of LPWA in the industrial field can be fully considered