이경순 Kyung-soon Lee , 조용운 Yong-un Cho , 김민정 Min-jung Kim

DOI: JANT Vol.28(No.5) 582-587, 2024

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The azimuth generator and acquirer for UAV navigation is a system that helps UAVs to precisely determine their own azimuth while they are flying, similar to the DVOR of existing civil aircraft. This system consists of a ground base station that generates an azimuth signal by the Doppler effect and a signal acquisition terminal that receives the azimuth signal and derives the azimuth of the UAV. This study focuses on the implementation of C-band radio navigation in the 5.03 ~ 5.15 GHz terrestrial band to cooperate with GNSS navigation mainly used in existing UAMs. This is one of the navigation technologies that can fully satisfy the requirements of Title 14 of CFR-135.165. According to the FAA, the use of two or more independent navigation sources for aircraft is proposed for aircraft. In this study, the design and implementation of the core technologies of the system, such as azimuth signal generation, sine/cosine signal generation required for azimuth derivation, phase detection comparator of AM/FM signals, and blending signal generator for antenna switching for the Doppler effect, were performed using FPGA. The results of azimuth derivation for 1000 samplings were confirmed to satisfy the ICAO standard of ±3° with a maximum deviation of ±1.1°.

정환호 Hwanho Jeong , 박건환 Geonhwan Park , 박소라 So-ra Park , 손민혁 Minhyuk Son

DOI: JANT Vol.28(No.5) 588-593, 2024

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Korea augmentation satellite system (KASS), KASS training and test platform (KTTP) was developed for KASS operator and maintainer training and KASS system verification, and it is an independently operated system. KTTP has one each of KASS reference station (KRS), KASS processing station (KPS), KASS uplink station (KUS), network bench, geostationary earth orbit (GEO) simulator and added the one central monitoring & control simulator (CMS) to switch the master operation mode to backup. Hardware and software of KTTP are identical to the KASS system. Therefore, the area where KTTP is installed must be verified through site infrastructure acceptance review (SIAR) in the same way as the KASS system. KTTP Verification is based on the KASS system integration, verification, qualification (IVQ) procedure, and verification was completed with a focus on the functionality rather than performance.

조현수 Hyunsoo Cho , 김은정 Eunjung Kim , 김성엽 Sung-yeob Kim , 이명식 Myeongsik Lee

DOI: JANT Vol.28(No.5) 594-600, 2024

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With the operation of the Korean satellite-based augmentation System (KASS), it has become possible to develop and implement localizer performance with vertical guidance (LPV) instrument approach procedures. In this study, we developed an LPV procedure for Runway 18 at Ulsan Airport, where the installation of an instrument landing system (ILS) is unable due to obstacles, and examined the potential reduction in flight cancellations. The study results suggest that, when developing an LPV instrument approach procedure, the decision altitude would be 380 feet, and the visibility minimum would be 1,200 meters. Consequently, it is expected that flight cancellations for Runway 18, based on 2023 cancellation data, could be reduced by 92% under the given visibility and ceiling conditions if LPV instrument approach procedure is developed. Therefore, the development and operation of the LPV instrument approach procedure for Runway 18 at Ulsan Airport is deemed essential.

김홍석 Hong-suk Kim , 반규리 Gyu-ri Ban , 서지훈 Ji-hun Seo , 정윤호 Yunho Jung

DOI: JANT Vol.28(No.5) 601-609, 2024

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In this paper, we present the design and implementation results of a system that classifies drones from other objects using an FMCW (frequency-modulated continuous wave) radar sensor. The proposed system detects various objects through a four-stage signal processing procedure, consisting of FFT, CFAR, clustering, and tracking, using signals received from the radar sensor. Subsequently, a deep learning process is conducted to classify the detected objects as either drones or other objects. To mitigate the high computational demands and extensive memory requirements of deep learning, a BNN (binary neural network) structure was applied, binarizing the CNN (convolutional neural network) operations. The performance evaluation and verification results demonstrated a drone classification accuracy of 89.33%, with a total execution time of 4 ms, confirming the feasibility of real-time operation.

최지헌 Jihun Choi

DOI: JANT Vol.28(No.5) 610-615, 2024

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Based on the K-UAM roadmap, this study evaluated the safety for the initial UAM demonstration project and operation. Research in each field is underway for early settlement of UAM, but the progress of research is showing limitations without clear regulations and lack of operational experience. This study aims to find a way for UAM to operate in reality, and for this purpose, the defense system for evaluating the safety of civil aviation was applied as SMS. In addition, the technical elements of the maneuvering of UAM aircraft were reviewed from a flight perspective. As a result, a unexpected problem was derived in the take-off and landing stage of the current airspace, flight corridor, and operation stage. Based on this, alternatives were derived and suggested to successfully complete the UAM demonstration project by FOSA which is Risk assessment Tool. Therefore, if the direction of UAM research is set by citing the results of this study, it is expected to contribute to the safe operation of UAM.

조인철 In-cheol Cho , 조성훈 Sung-hoon Cho , 안지훈 Ji-hoon An , 문현욱 Hyun-wook Moon , 손성환 Sung-hwan Sohn , 정태희 Taehee Jeong , 임상호 Sangho Lim

DOI: JANT Vol.28(No.5) 616-622, 2024

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Recently, each country is competitively investing huge amounts of money in space development, and space risks such as tens of thousands of satellites, spy satellites, and space debris are increasing. Although there are several assets for monitoring space, interest is growing in the detection of space objects using radar, which is useful for constant alert and wide-area surveillance. While the existing radar system was operated to detect aircraft, ships, and missiles within hundreds of kilometers, radar to detect space objects must be expanded to thousands of kilometers. In this case, the size of data that impairs signal processing increases, which can lead to a decrease in radar detection performance. In this paper, we present a method of speeding up signal processing using GPU when detecting space objects, which are long-distance targets, and the results of comparing performance compared to existing CPUs.

김하은 Ha-eun Kim , 김상일 Sang-il Kim , 이성섭 Soung-sub Lee

DOI: JANT Vol.28(No.5) 623-631, 2024

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Currently, the Korean military is promoting a small satellite system project to establish a command and control system that can quickly respond to various threats from all directions, not only from North Korea. In this paper, we present a nonlinear control law to acquire the geometry of a small cluster satellite deployment using a low-thrust electric propulsion system, the Hall thruster. The control law is obtained by applying the general Lyapunov’s control theory and analytical solution for the on-off control of the electric thruster, and it is a technique that can effectively deploy the orbital configuration of the satellite constellation by controlling only the semi-major axis of the six elements of the orbit. In this study, the stability of the developed control law is verified and the results are analyzed for application to a very small satellite system.

정성재 Seong-jae Jeong , 정다나 Da-na Jung , 조성희 Sung-hee Cho , 김민선 Min-seon Kim , 남덕우 Deok-woo Nam

DOI: JANT Vol.28(No.5) 632-639, 2024

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In this paper, the analysis method and results of audio data through LVDS interface and data Acquisition of the intercom. Intercom uses LVDS interface to transmit/receive digital audio data between audio interface unit and intercom control panel and to data acquisition of audio signals. Data acquisition using LVDS interface is essential for downloading various audio signals interfaced to the intercom to a PC and performing data analysis on noise, audio qualitys, etc. To achieve this, hardware for audio data acquisition was configured in the intercom test equipment. As a result, individual analysis of intercom input/output audio signals before and after logic processing was possible, which was effective in deriving the cause of noise signals. In addition, by data acquisition on actual voice communication and audio signals in ac system integrated laboratory and an environment/ electromagnetic test, audio signal level measurements and frequency analysis were performed to debug noise signal removal and verify the audio quality of the intercom.

유태훈 Tae-hoon Yoo , 방현태 Hyeon-tae Bang , 윤원근 Won-keun Youn

DOI: JANT Vol.28(No.5) 640-649, 2024

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In this study, we introduce an interactive multi-model-probabilistic data association filter (IMM-PDAF), a multi-target tracking algorithm that integrates multiple dynamic models for accurate real-time maritime target tracking. Multi-target tracking in the maritime environment requires high accuracy due to the complex dynamic environment and various movement patterns. The existing CV-PDAF (constant velocity model) and CT-PDAF (circling model) each assume a constant movement pattern, but it is difficult to handle all the complex movements occurring in various maritime environments with these single models. To solve this problem, this study proposes an interactive multi-model-probabilistic data association filter (IMM-PDAF), and the results of this paper applied to maritime RADAR data show that the proposed IMM-PDAF has relatively lower RMSE values than CV-PDAF and CT-PDAF, and has strong positioning performance even in complex dynamic environments. Therefore, this study results highlight the potential of the proposed IMM-PDAF to improve the reliability and efficiency of maritime surveillance systems and provide a multi-target tracking solution for complex tracking environments.

정상규 Sang Gyu Jeong , 권나은 Na Eun Kwon , 김형우 Hyung Woo Kim

DOI: JANT Vol.28(No.5) 650-656, 2024

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This study proposes an AI-based image restoration technique to reduce image distortion caused by lighting and noise in nighttime environments and improve the performance of infrared detection systems. A synthetic image dataset was constructed using visible light images under various lighting conditions and ISO settings, and deep learning models (AutoEncoder and U-Net) were trained to assess image restoration performance. Experimental results show that the Multi-ISO model (9-channel) outperforms the Single-ISO model (3-channel), especially when utilizing input data with multiple ISO values. This study demonstrates that AI models can be effectively trained using synthetic data, even when real data collection is challenging, and can be applied to image restoration tasks. These findings are expected to contribute to enhancing the performance of optical detection systems through AI-based technology.

윤희석 Hi-seok Yoon

DOI: JANT Vol.28(No.5) 657-663, 2024

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Among the components of the international standard navigation system (CNS/ATM), the role and importance of aviation surveillance are increasingly critical for enhancing the efficiency and safety of air traffic operations. Among these, the automatic dependent surveillance-broadcast (ADS-B) system has expanded its usage due to advancements in satellite navigation systems and digital data communication technologies, providing both safety and economic benefits. However, its use domestically remains limited due to infrastructure deficiencies and difficulties in system integration. This paper will examine the usage and advantages of ADS-B in advanced aviation nations, assess the necessity for effective ADS-B system implementation domestically, explore the potential joint use of ADS-B with AAM and General Aviation, and analyze expert opinions to propose a priority list for building the required national ADS-B infrastructure and operational systems.

김효중 Hyo-joung Kim , 김지민 Ji-min Kim , 박찬영 Chan-young Park , 권병기 Byung-gi Kwon

DOI: JANT Vol.28(No.5) 664-669, 2024

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Recently, the development of a Korean fighter jet is underway in Korea. As a result, various armament/equipment that can perform various missions will be installed and linked. In order for the aircraft and armament/equipment to be successfully installed and linked, they must be designed and developed based on linkage standards and must operate according to the operating procedures. In addition, safety and reliability must be verified through many repeated tests. In this paper, in order to optimize the resources (time, cost, manpower) consumed by performing repeated tests, an inspection system was developed according to the MIL-STD-1760, an airborne standard interface, and software that can perform aircraft linkage procedures in real time was installed to secure an integrated inspection system that can verify the linkage of armament/equipment in advance.

김민지 Minji Kim , 김경택 Kyung-taek Kim

DOI: JANT Vol.28(No.5) 670-677, 2024

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In this study, the flight test measurement data and flight test items for metal-based brake pads for transport aircraft were derived through the analysis of Korea and the U.S. aviation-related regulations, technical standards and airworthiness standards. During the flight test, the measurement items should be measured at all times, such as aircraft altitude, speed, aircraft condition, wind direction, wind speed, and air-temperature. The flight test items of the brake pad should be quantitatively evaluated for stopping performance during landing, fuse plug integrity, stopping performance at reject take-off situations, anti-skid compatibility during landing and parking brake capability. Additionally, qualitative evaluation of the flight test pilot's aircraft steering characteristics under each test condition is required. The identification of risk factors for each test item and measures to mitigate risk factors must be approved in advance before the flight test, and the risk factors must be reevaluated to maintain suitability for the flight test during the flight test, and the results must be documented.

최홍락 Hong-rak Choi , 최준성 Junsung Choi

DOI: JANT Vol.28(No.5) 678-685, 2024

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The manual direction-finding method detects a target that emits radio waves using a base station or vehicle, utilizing various techniques. However, base stations and vehicles have many limitations in mobility and are heavily affected by environmental factors, and the techniques traditionally used could only detect the target’s location in two dimensions. Therefore, this study presents a technique for detecting the target’s location in three dimensions using an unmanned aerial vehicle(UAV), which is widely used for civilian and commercial purposes and combines mobility with a higher vantage point. We propose the method that estimates the target's location by generating a virtual 3D sphere using only the received power, and we conducted a simulation to analyze the results. The simulation was compared and analyzed with ground vehicle measurement data to evaluate the performance of 3D direction-finding when positioning the UAV at the same location.

오성탁 Sungtak Oh , 신정훈 Jeonghun Shin , 이진우 Jinwoo Lee , 이동진 Dongjin Lee

DOI: JANT Vol.28(No.5) 686-697, 2024

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To ensure stable urban flight of electric vertical take-off and landing(eVTOL) aircraft, securing handling qualities and stability is essential. However, clear handling qualities standards for eVTOL aircraft, which have different characteristics from conventional manned aircraft, have not yet been established. Therefore, this paper identifies handling qualities evaluation criteria suitable for eVTOL aircraft based on the handling qualities standards for manned aircraft and designs a control system that meets the predicted handling qualities criteria through evaluation. simplified vehicle operation(SVO) control laws and stability and control augmentation system(SCAS)-based control laws were applied to the lift-cruise configuration eVTOL aircraft. Using control designer's unified interface(CONDUIT), it was confirmed that the level 1 standard was met, and to validate the system, assigned handling qualities evaluation was performed using handling qualities task elements(HQTE) in an X-Plane based simulation environment, resulting in the design of a control system that ensures handling qualities.

신재권 Jae-kwon Shin , 최지환 Ji-hwan Choi , 최낙민 Nak-min Choi , 김정열 Jeong-yeol Kim , 김준형 Jun-hyoung Kim

DOI: JANT Vol.28(No.5) 698-705, 2024

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In recent years, the aircraft interior industry has been rapidly evolving, incorporating advanced information technology (IT) elements as competition in the aviation industry intensifies. In Korea, a display system for aircraft, called cabin display system (CDS), is being developed in collaboration with Boeing. This paper discusses the design and implementation of cabin display system remote control software (CDS RCS), a remote control software for the CDS. CDS RCS was developed by applying the aircraft data load process developed in-house using the ARINC-615A standard, and the communication protocol between devices applies the MQTT protocol. Unlike existing CDS control software, CDS RCS is designed as an MQTT client and can operate independently of other MQTT clients. It is also developed for android-based devices, which can be easily installed on personal terminals, and is expected to greatly enhance the convenience of flight attendants.

김우곤 Woogon Kim , 서예준 Yejune Seo , 강승택 Sungtek Kahng

DOI: JANT Vol.28(No.5) 706-712, 2024

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For wirelessly connecting the RF sensing of the radar with a long distant object, the system must have antennas of a high gain. Conventionally, they adopt arrays and curved lenses, but have problems of conductor and dielectric loss in the feed and ending up with a large volume. This paper proposes an FR-4-substrate flat metasurface lens to intensify the RF signal, which undergoes design, fabrication and test. To verify the design method, the antenna sized 64×64mm2 is prototyped by inexpensive FR-4 PCB etching process and its S11 and radiated wave are measured. Gain increase of around 10 dB and high directivity are observed at the K-band.

황태영 Tae-young Hwang , 정하늘 Ha-neul Jung , 김장훈 Jang-hoon Kim , 박병호 Byung-ho Park , 최원 Won Choi

DOI: JANT Vol.28(No.5) 713-719, 2024

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This paper simulates through simulation by modeling the transmitter and receiver equivalently to enable wireless power transfer (WPT) within a metal-shielded space, and verifies the results through experiments. Through this, various influencing factors on the power transfer efficiency (PTE) of the wireless power transmission system in a metal-shielded space have been closely analyzed, and a concrete and effective method for improving the power transfer efficiency of the wireless power transmission system is suggested based on the analyzed factors. In addition, the experiment of receiving Manchester code information by enabling data transmission through wireless power transmission through the receiving coil within the metal shielding space has been verified. Through this, we would like to present the possibility of an efficient wireless power transmission system within the metal shielding space.

이원준 Won Jun Lee

DOI: JANT Vol.28(No.5) 720-725, 2024

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In this paper, we propose a microstrip patch antenna with polarization-switching characteristics using parasitic elements and PIN diodes placed at the sides of the microstrip patch. The proposed antenna is designed by arranging four linear parasitic elements along the sides of a square-shaped microstrip patch, with each parasitic element connected to a PIN diode. By utilizing the open and short circuit characteristics of the PIN diodes based on the applied bias, the electrical length of the parasitic element slots is altered, enabling polarization switching between right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP). The proposed antenna resonates at 4.21 GHz, with a return loss of 17.5 dB and a bandwidth of 135 MHz when operating in RHCP mode, and a return loss of 18.4 dB and a bandwidth of 144 MHz when operating in LHCP mode. Additionally, the axial ratios for RHCP and LHCP are 2.53 dB and 2.52 dB, respectively, and the gains are 6.62 dBic and 6.32 dBic, respectively.

조한석 Han Seok Cho , 김종규 Jong Kyoo Kim , 박병호 Byung Ho Park , 최원 Won Choi

DOI: JANT Vol.28(No.5) 726-731, 2024

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This paper proposes a charge-discharge control circuit using capacitors and verifies the performance of the circuit for charge, emission, and discharge operations. The proposed control circuit performs multiple emission operations without inter-circuit influence because it uses capacitors independently for each emission circuit. Even with the instability of the input power, the output energy during emission stably supplies more than 1.6 mV of energy, which is the energy required for output, through the charging function of the capacitor. After release, the remaining energy of the capacitor is safely discharged by more than 99% of the 3.125 V remaining in the capacitor through the discharge function of the capacitor, confirming that approximately 25 mV remained. The proposed control circuit confirmed the stability and reliability of the emission device through simulation and measurement results.

이성렬 Seong-real Lee

DOI: JANT Vol.28(No.5) 732-737, 2024

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We systematically studied the chromatic dispersion and nonlinear distortion compensation characteristics of 24-channel × 40 Gb/s wavelength division multiplexed (WDM) signal in a mid-span spectral inversion (MSSI) system with dispersion-managed link. WDM signals are transmitted over dispersion-managed link consisting of an 80 km × 48 fiber span including erbium-doped fiber amplifier (EDFA). The dispersion map applied to this dispersion-managed link has trapezoidal shape with various structures. The trapezoid-shaped dispersion map examined in this paper are designed with configuration in which the cumulative dispersion profile has positive or negative value in each section before and after the optical phase conjugator. Through simulation, it was confirmed that the proposed trapezoid-shaped dispersion map is effective in compensating for distorted WDM channel signals when the dispersion map is configured with the small RDPS (residual dispersion per span).

윤인식 In-sik Yun , 문일영 Il-young Moon

DOI: JANT Vol.28(No.5) 738-744, 2024

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The goal of this system is to effectively summarize and visualize important DICOM image data in the medical field. Using React and Node.js, the system collects and parses DICOM images, extracting critical medical information in the process. It then employs a large language model (LLM) to generate automatic summary reports, providing users with personalized medical information. This approach enhances accessibility to medical data and leverages web technologies to process large-scale data quickly and reliably. The system also aims to improve communication between patients and doctors, enhancing the quality of care and enabling medical staff to make faster, more accurate decisions. Additionally, it seeks to improve patients' medical experiences and overall satisfaction. Ultimately, the system aims to improve the quality of healthcare services.

손봉기 Bong-ki Son

DOI: JANT Vol.28(No.5) 745-753, 2024

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In this paper, we propose a system that extracts customer data from self-photos taken through a photo booth and automatically generates an operation report consisting of analysis results for each data and marketing strategy suggestions. The customer data to be extracted was selected based on attributes that could be used to analyze event operation results or to plan next year's event and establish promotional strategies. We utilize ChatGPT4o in image analysis, customer data analysis, and next marketing strategy proposal. As a result of analyzing self-photos taken at a local festival through the proposed system, customer data such as the number of people photographed, gender, age, relationship, and hairstyle were analyzed with high accuracy. In addition, the proposed system was shown to automatically generate operational reports based on customer data and marketing strategies extracted and analyzed by ChatGPT4o.

함승태 Seung-tae Ham , 홍성화 Sung-hwa Hong

DOI: JANT Vol.28(No.5) 754-759, 2024

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In this paper, we implemented a detection and surveillance system using webcam and thermal camera modules as a method to counter various crimes that are increasing in modern society. For human detection using a webcam, we applied a detection method called Haar-like features, which utilizes the characteristics of dark and bright areas in different parts of the face. We also integrated two approaches, one is a contactless method that detects the infrared radiation emitted from the subject and displays information, and the other is a method that detects infrared radiation emitted from the human body and displays thermal images using an interpolation technique. To accomplish this, we equipped Raspberry Pi with these two modules and built the system. It is expected that by using this interpolation technique, the efficiency of recognition information will be enhanced when integrating with various information sensors in the future.

정용진 Yong-jin Jung , 오창헌 Chang-heon Oh

DOI: JANT Vol.28(No.5) 760-766, 2024

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Machine learning and deep learning are being researched in various fields and applied in real life. Designing reliable models is crucial, and understanding the results of these models is necessary. This paper analyzes the impact of variables on prediction values using SHAP. Prediction models for PM_2.5 were designed using DNN and LSTM algorithms. The training and test data were composed by selecting weather data and air pollutant data through correlation analysis. The RMSE and accuracy for AQI categories were checked for both prediction models, with the LSTM algorithm showing slightly better performance. The contribution of variables to the prediction values of both models was confirmed using SHAP. It was found that air pollutant data had a high contribution in predicting PM_2.5, and temperature among weather data had a high contribution in the prediction process of both models. Both models showed that high values of temperature, wind speed, and sea level pressure decreased prediction values, while low values increased them. For NO₂, PM₁₀, and SO₂, the LSTM model showed a bidirectional impact on prediction values, unlike the DNN model.