강인숙 In-suk Kang , 주인웅 In-ung Ju , 김정연 Jeong-yeon Kim , 최조천 Jo-cheon Choi

DOI: JANT Vol.25(No.6) 433-440, 2021

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The problem of maritime accidents due to the carelessness of fishing vessels, which is affected by the aging of fishing vessel operators. And there is navigation, communication and fish finder that is installed inside the narrow bridge of a fishing vessel. Therefore these system are monitors as many as of each terminal, which is bad influence on obscuring view of front sea from a fishing vessel bridge. In addition a large problem, it is occurs to reduce of the information recognition ability due to the confusion, which is can not check the display information each of screen equipments. Therefore, there has been demand to simply integrated the equipment, and it has wanted the integrated support system of these equipment. The display must be provided on a fishing vessels such as electronic charts, communications equipments and fish detection into one case. In this paper, the integrated system will be installed the GPS plotter, AIS, VHF-DSC, V-pass, fish finder and power supply in the narrow wheelhouse on a fishing vessel, which is configured in one case and operated by multi function display (MFD). The MFD is integrated to simplify for several multi terminals and provided necessary information on a single screen. This integration fishery support system will has improved in sea safety operation and fishery environment of fishing vessels by this implementation.

양장훈 Janghoon Yang

DOI: JANT Vol.25(No.6) 441-449, 2021

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With advances in autonomous vehicles, there is a growing demand for more accurate position estimation. Especially, this is a case for a moving robot for the indoor operation which necessitates the higher accuracy in position estimation when the robot is required to execute the task at a predestined location. Thus, a method for improving the position estimation which is applicable to both the fixed and the moving object is proposed. The proposed method exploits the initial position estimation from Bluetooth beacon signals as observation signals. Then, it estimates the gravitational acceleration applied to each axis in an inertial frame coordinate through computing roll and pitch angles and combining them with magnetometer measurements to compute yaw angle. Finally, it refines the control inputs for an object with motion dynamics by computing acceleration on each axis, which is used for improving the performance of Kalman filter. The experimental assessment of the proposed algorithm shows that it improves the position estimation accuracy in comparison to a conventional Kalman filter in terms of average error distance at both the fixed and moving states.

정한균 Han-gyun Jung , 진성근 Seong-keun Jin , 곽재민 Jae-min Kwak

DOI: JANT Vol.25(No.6) 450-455, 2021

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In this paper, we introduce the contents of research on the establishment of an evaluation environment for autonomous cooperative driving platform for commercial vehicles based on V2X communication. For the evaluation of the autonomous cooperative driving platform based on V2X communication, various standards, standards, and guidelines for test evaluation should be developed and provided to the test subject, along with the establishment of test beds such as roads and V2X infrastructure that can apply various driving scenarios. do. In addition, based on this, various reference equipment and test equipment for actual test and evaluation should be developed. In this paper, various technologies, standards, equipment, and construction infrastructure developed to construct the evaluation environment for autonomous cooperative driving platform for commercial vehicles based on V2X communication are introduced.

김준환 Jun-hwan Kim , 백현진 Hyun-jin Paek , 이종원 Jong-won Lee , 안주현 Joo-hyun Ahn

DOI: JANT Vol.25(No.6) 456-465, 2021

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For predictive aviation safety management, the establishment of safety performance indicators to measure and manage the safety performance of service providers must be preceded. In particular, leading indicators are significant in that they play an important role in identifying and managing the causes of accident/incident in advance. However, the current safety performance indicators of the domestic aviation industry have limitations in that they focus on lagging indicators based on events that have already occurred. Therefore, the purpose of this study is to construct Korean leading indicators for preventive safety management. In addition, we verify the validity and importance of the indicators based on review of the experts and AHP analysis. This study is meaningful in that it can support the proactive safety management of the domestic aviation industry through the development of leading safety indicators, which have been relatively lacking in research.

전종진 Jong-jin Jeon , 이현승 Hyun-seung Lee

DOI: JANT Vol.25(No.6) 466-475, 2021

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Airport-related laws restrict the installation of lights that obstruct the identification of airport lights or cause glare to pilots and controllers around the airport. However, with regard to the glare that lights give to the pilot or controller, it is only judged whether there is a limit based on a qualitative judgment, and a quantitative review has not been made. Therefore, in this study, visual disturbances that may occur to pilots and controllers due to large lighting facilities around airports during nighttime flight operation were quantitatively calculated and confirmed through disability glare, object recognition, and identification obstruction. And based on this study, it was suggested to supplement the related system to prevent the visual impairment of pilots and controllers caused by lighting facilities.

류재영 Jae-young Ryu , 이현웅 Hyeonwoong Lee , 박배선 Bae-seon Park , 이학태 Hak-tae Lee

DOI: JANT Vol.25(No.6) 476-483, 2021

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In order to maintain the safety of the airspace with ever increasing traffic volume, it is necessary to thoroughly analyze the collision risk with the current data. In this study, collision risk analysis was conducted using Detect and Avoid (DAA) Well-Clear (DWC) metrics, risk induces developed for the DAA systems of unmanned aerial vehicles. All flights in year 2019 that flew within the Incheon Flight Information Region (FIR) boundary were analyzed using the recorded Automatic Dependent Surveillance-Broadcast(ADS-B) data. High risk regions as well as trends by airports and seasons were identified. The results indicate that the risk is higher around the congested area near Incheon International Airport and Gimpo International Airport. Seasonally, the risk was highest in August that coincides with the Summer vacation period. The result will be useful for the baseline data for various aviation safety enhancement activities such as revision of routes and procedures and training of the field specialists.

이성봉 Seongbong Lee , 박천만 Cheonman Park , 김혜지 Hyeji Kim , 이동진 Dongjin Lee

DOI: JANT Vol.25(No.6) 485-492, 2021

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Vision-based autonomous precision landing technology for UAVs requires precise position estimation and landing guidance technology. Also, for safe landing, it must be designed to determine the safety of the landing point against ground obstacles and to guide the landing only when the safety is ensured. In this paper, we proposes vision-based navigation, and algorithms for determining the safety of landing point to perform autonomous precision landings. To perform vision-based navigation, CNN technology is used to detect landing pad and the detection information is used to derive an integrated navigation solution. In addition, design and apply Kalman filters to improve position estimation performance. In order to determine the safety of the landing point, we perform the obstacle detection and position estimation in the same manner, and estimate the speed of the obstacle using LSM. The collision or not with the obstacle is determined based on the CPA calculated by using the estimated state of the obstacle. Finally, we perform flight test to verify the proposed algorithm.

임상훈 Sang-hoon Lim , 허백용 Baek-yong Heo , 황호원 Ho-won Hwang

DOI: JANT Vol.25(No.6) 492-497, 2021

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Smart Security is the global initiative of Airports Council International in collaboration with airports, airlines and governmental agencies. Its main objective is to create a step change in passenger and cabin baggage screening, escalating security costs and constantly evolving threats. Incheon International Airport should adopt and deploy smart security systems not only to strengthen aviation security but also increase passenger’s experiences and operational efficiency by way of seamless security screening that it will lead to establish the best security environment to prevent terrorism and acts of unlawful interference.

박정우 Jeongwoo Park , 김휘양 Huiyang Kim , 구성관 Sungkwan Ku

DOI: JANT Vol.25(No.6) 498-509, 2021

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The wake turbulence at the wingtip of preceding aircraft may affect the normal operation of following aircraft. Aircraft are classified into four categories according to their maximum take-off weight, and horizontal separation is applied with this category matrix. The FAA and EUROCONTROL revealed that the magnitude and effect of preceding aircraft wake turbulence were smaller than the current distance separation minima suggest. This new information presents the opportunity for revising wake turbulence minima into seven categories (RECAT). This paper confirms the feasibility of implementing RECAT at major airports in South Korea using the draft of ICAO Doc. 10122. The paper also calculates the ultimate runway capacity of Incheon International Airport in South Korea using the Harris Model and comparatively analyzes the amount of runway capacity. As a result of the analysis, it was confirmed that the implementation of RECAT could increase the ultimate runway capacity of Incheon International Airport. This paper's calculation methods and results can be used as primary data for implementing RECAT in other airports.

구성관 Sungkwan Ku , 안효정 Hyojung Ahn , 주요한 Yo-han Ju , 홍석민 Seokmin Hong

DOI: JANT Vol.25(No.6) 510-516, 2021

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Recently, the range of utilization and demand for unmanned aerial vehicle (UAV) has been continuously increasing, and research on the construction of a separate operating system for low-altitude UAV is underway through the development of a management system separate from manned aircraft. Since low-altitude UAVs also fly in the airspace, it is essential to establish technical standards and certification systems necessary for the operation of the aircraft, and research on this is also in progress. If the operating standards and certification requirements of the aircraft are presented, a test method to confirm this should also be presented. In particular, the accuracy of small UAV’s navigation required during flight is required to be more precise than that of a manned aircraft or a large UAV. It was necessary to calculate a separate navigation error. In this study, we presented a test method for deriving navigation errors that can be applied to UAVs that have difficulty in acquiring long-term operational data, which is different from existing manned aircraft, and conducted verification tests.

이성렬 Seong-real Lee

DOI: JANT Vol.25(No.6) 517-522, 2021

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Optical dispersion-managed link combined with optical phase conjugation for compensating of the distorted optical signals due to chromatic dispersion and nonlinear effects, which is required to implement long-haul wavelength division multiplexed system, is proposed and assessed in viewpoint of network topology flexibility. Optical phase conjugator capable to compensate for the distorted optical signal due to nonlinear effects is placed non-midway of total transmission distance. And, in dispersion-managed link, residual dispersion per span (RDPS) of each fiber spans in former half section and latter half section with respect to optical phase conjugator are different to each other. Simulation results show when the RDPS of each fiber sections in one half section makes it’s own net residual dispersion slight different from another half section’s net residual dispersion, the compensation effect in the proposed link configuration is more increased.

이성렬 Seong-real Lee

DOI: JANT Vol.25(No.6) 523-529, 2021

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This paper shows the design and fabrication of antenna embedded in marine buoy for marine IoT service, especially automatic identification system of fishing gears. Frequency band of proposed antenna has dual band of 433 MHz and 920 MHz considering marine IoT extension. Dual pattern monopole type for 920 MHz and meander type for 433 MHz are adopted in the proposed antenna. Voltage standing wave ratio is obtained 1.548 at 433 MHz and obtained 1.5 of mean value at 920 MHz band by measuring the fabricated antenna. The maximum antenna gain of 3.83 dBi is measured at 902 MHz among 920 MHz band, while antenna gain of 433 MHz is obtained 1.18 dBi. Although antenna gain of 433 MHz is low than 920 MHz band, this gain is larger than desired value of -5 dBi. And, it is confirmed that other measured values meet the performance criteria for archiving communication distance of 10 km between marine buoy and fishing ship in automatic identification system of fishing gears.

여준호 Junho Yeo , 이종익 Jong-ig Lee

DOI: JANT Vol.25(No.6) 530-535, 2021

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In this paper, the design method for a chipless RFID tag using ELC resonators is proposed. A four-bit chipless RFID tag is designed in a two by two array configuration using three ELC resonators with different resonant peak frequencies and one compact IDC resonator. The resonant peak frequency of the bistatic RCS for the IDC resonator is 3.125 GHz, whereas those of the three ELC resonators are adjusted to be at 4.225 GHz, 4.825 GHz, and 5.240 GHz, respectively, by using the gap between the capacitor-shaped strips in the ELC resonator. The spacing between the resonators is 1 mm. Proposed four-bit tag is fabricated on an RF-301 substrate with dimensions of 50 mm×20 mm and a thickness of 0.8 mm. It is observed from experiment results that the resonant peak frequencies of the fabricated four-bit chipless RFID tag are 3.290 GHz, 4.295 GHz, 4.835 GHz, and 5.230 GHz, respectively, which is similar to the simulation results with errors in the range between -2.3% and 0.2%.

김민우 Min-woo Kim , 신동기 Dong-gi Shin , 류오림 Oh-rim Ryu , 이영순 Young-soon Lee

DOI: JANT Vol.25(No.6) 536-542, 2021

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In this paper, we proposed a triple band printed monopole antenna with a bent branch strips for WiFi / 5G. An antenna structure in which bent strips for generating multiple resonance are attached in the form of branches was newly proposed based on a typical monopole strip vertically erected as a triple band antenna structure. The proposed antenna is designed on a FR-4 substrate with dielectric constant 4.3, thickness of 1.6 mm, and size of 28×40 ㎟. The measured impedance bandwidth is 430 MHz (2.22~2.65 GHz) in the 2.4 GHz WLAN, 450 MHz (3.38~3.83 GHz) in the 3.5 GHz and 2390 MHz (4.95~ 7.34 GHz), In particular, it has been observed that antenna has a stable omnidirectional radiation patterns as well as gain of 1.537 dBi, 1.878 dBi and 2.337 dBi in the entire frequency band of interest.

최성혜 Sung-hye Choe , 박기영 Ki-young Park , 김형민 Hyoung-min Kim , 양철관 Cheol-kwan Yang

DOI: JANT Vol.25(No.6) 543-549, 2021

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In this paper, a robust transfer alignment method is proposed for a strapdown inertial navigation system(SDINS) with norm-bounded parametric uncertainties. The uncertainties are described by the energy bound constraint, i.e., sum quadratic constraint(SQC). It is shown that the SQC can be coverted into an indefinite quadratic cost function in the Krein space. Krein space Kalman filter is designed by modifying the measurement matrix and the variance of measurement noises in the conventional Kalman filter. Since the proposed Krein space Kalman filter has the same recursive structure as a conventional Kalman filter, the proposed filter can easily be designed. The simulation results show that the proposed filter achieves robustness against measurement time delay and high dynamic environment of the vehicle.

한형석 Hyung-seok Han

DOI: JANT Vol.25(No.6) 551-556, 2021

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In this paper, we deal with the stability condition of linear interval discrete systems with time-varying delays and unstructured uncertainty. For the interval discrete system which has interval matrix as its system matrices, time-varying delay time within some interval value and unstructured uncertainty which can include non-linearity and be expressed by only its magnitude, the stability condition is proposed. Compared with the previous result derived by using a upper bound solution of the Lyapunov equation, the new results are derived by the form of simple inequality based on Lyapunov stability condition and have the advantage of being more effective in stability application. Furthermore, the proposed stable conditions are very comprehensive and powerful, including the previously published stable conditions of various linear discrete systems. The superiority of the new condition is proven in the derivation process, and the utility and superiority of the proposed condition are examined through numerical example.

용성중 Sung-jung Young , 박효경 Hyo-gyeong Park , 유연휘 Yeon-hwi You , 문일영 Il-young Moon

DOI: JANT Vol.25(No.6) 557-561, 2021

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A meatadata has become an essential element in order to recommend video content to users. However, it is passively generated by video content providers. In the paper, a method for automatically generating metadata was studied in the existing manual metadata input method. In addition to the method of extracting emotion tags in the previous study, a study was conducted on a method for automatically generating metadata for genre and country of production through movie audio. The genre was extracted from the audio spectrogram using the ResNet34 artificial neural network model, a transfer learning model, and the language of the speaker in the movie was detected through speech recognition. Through this, it was possible to confirm the possibility of automatically generating metadata through artificial intelligence.

최홍현 Hong-hyeon Choi , 이승훈 Seung-hoon Lee , 이정두 Jeong-du Lee , 유진 Jin Yu , 정성훈 Seong-hoon Jeong , 심준환 Joon-hwan Shim

DOI: JANT Vol.25(No.6) 562-568, 2021

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Seat reservations and civil complaints in the library reading room have been done face-to-face by managers, and efficient management has been difficult. In addition, there is a problem that it is difficult to take action in the event of a civil complaint due to user inconvenience, such as a noise problem between users in the reading room. In this study, an online reservation system was developed for efficient management of seats in the library reading room so that it could be serviced non-face-to-face. In addition, when using the library reading room, it is possible to apply for non-face-to-face civil complaints when complaints occur due to noise problems between users, loss of belongings, and snoring during the user's sleep. Managers can smoothly manage library reading rooms through non-face-to-face inconvenience reports. It is possible to increase the satisfaction of using the library by resolving the inconvenience of users. The developed service app allows seat reservations and anonymous inconvenience reports. The administrator can check the received inconvenience report and warn the user of the seat with an IoT sensor-based LED. When corrective action is completed, the result of the action may be fed back to the reporter.

김재정 Jae-jung Kim , 유용훈 Yong-hun You , 김창복 Chang-bok Kim

DOI: JANT Vol.25(No.6) 569-575, 2021

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Deep learning shows differences in prediction performance depending on data quality and model. This study uses various input data and multiple deep learning models to build an optimal deep learning model for predicting solar radiation, which has the most influence on power generation prediction. did. As the input data, the weather data of the Korea Meteorological Administration and the clairvoyant meteorological image were used by segmenting the image of the Korea Meteorological Agency. , comparative evaluation, and predicting solar radiation by constructing multiple deep learning models connecting the models with the best error rate in each model. As an experimental result, the RMSE of model A, which is a multiple deep learning model, was 0.0637, the RMSE of model B was 0.07062, and the RMSE of model C was 0.06052, so the error rate of model A and model C was better than that of a single model. In this study, the model that connected two or more models through experiments showed improved prediction rates and stable learning results.

조경우 Kyoung-woo Cho , 정용진 Yong-jin Jung , 오창헌 Chang-heon Oh

DOI: JANT Vol.25(No.6) 576-581, 2021

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Compared to a low concentration, a high concentration clearly entails limitations in terms of predictive performance owing to differences in its frequency and environment of occurrence. To resolve this problem, in this study, an artificial intelligence neural network algorithm was used to classify low and high concentrations; furthermore, two prediction models trained using the characteristics of the classified concentration types were used for prediction. To this end, we constructed training datasets using weather and air pollutant data collected over a decade in the Cheonan region. We designed a DNN-based classification model to classify low and high concentrations; further, we designed low- and high-concentration prediction models to reflect characteristics by concentration type based on the low and high concentrations classified through the classification model. According to the results of the performance assessment of the prediction model by concentration type, the low- and high-concentration prediction accuracies were 90.38% and 96.37%, respectively.