The Overseas Research Trends for the On Demand Mobility and Domestic Application Plan Using PAV
임은하 Eunha Lim , 황호연 Hoyon Hwang , 차재영 Jaeyoung Cha , 김석범 Seokbeom Kim , 박병운 Byungwoon Park
21(4) 313-324, 2017
임은하 Eunha Lim , 황호연 Hoyon Hwang , 차재영 Jaeyoung Cha , 김석범 Seokbeom Kim , 박병운 Byungwoon Park
DOI: JANT Vol.21(No.4) 313-324, 2017
At present, many countries around the world, as well as Korea, have faced serious social problems due to increased traffic congestion resulting in the social loss. As a result, there is an increasing demand for new transportation which is not exist. This is why many companies around the world are trying to solve this problem with transportation innovation through On Demand Mobility(ODM) which uses Personal Air Vehicle(PAV) that is operated on demand by customer rather than scheduled transportation. This study analyzed the current research trends of the On Demand Mobility projects of National Aeronautics and Space Administration (NASA), UBER, and AIRBUS. Also, this study presents the benefit of adopting this On Demand Mobility systems into Korea. Three commuting routes were set up in the metropolitan area in Korea, and the benefit of using the On Demand Mobility method was compared with the current public transportation and private car.
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Performance analysis for Ground Position Accuracy Test of MLAT
구본수 Bon-soo Koo , 장재원 Jae-won Jang , 김우리얼 Woo-riul Kim , 김태식 Tae-sik Kim
21(4) 325-331, 2017
구본수 Bon-soo Koo , 장재원 Jae-won Jang , 김우리얼 Woo-riul Kim , 김태식 Tae-sik Kim
DOI: JANT Vol.21(No.4) 325-331, 2017
As a GPS stability problem arises, MLAT system is spotlighted as an alternative technology of ADS-B. MLAT system has a high position accuracy as much as ADS-B. Also, MLAT receives the mode A,C,S, and 1090ES(ADS-B) signals from the mounted aircraft transponder. MLAT receives signals from several receiver units and calculates aircraft positions. MLAT has ADS-B level positioning accurarcy using GPS and can calculate the position information with objects independently. According to global environment changes, Local area multiltilateration(LAM) surveillance system is under development for moving vehicles and aircraft detection in airport. These are still under testing in Tae-an Airfield. In the paper, we analyzed the performance by comparing the calculated position data from MLAT to RTK. In order to confirm the position accuracy of MLAT and the deviation of position data between fixed target and moving target on the ground during the field test in Tae-an Airfield.
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Design and Experimental Study of a Launch and Recovery System for an Underwater Tow-fish with Consideration of Sea State
강진일 Jin-il Kang , 서주노 Joo-no Sur , 정성훈 Seong-hoon Jeong , 최형식 Hyeung-sik Choi , 김준영 Joon-young Kim , 김명경 Myung-gyung Kim , 유용준 , Jung-hoon Kim
21(4) 332-338, 2017
강진일 Jin-il Kang , 서주노 Joo-no Sur , 정성훈 Seong-hoon Jeong , 최형식 Hyeung-sik Choi , 김준영 Joon-young Kim , 김명경 Myung-gyung Kim , 유용준 , Jung-hoon Kim
DOI: JANT Vol.21(No.4) 332-338, 2017
Launch and recovery system(LARS) is required to perform an USV-based underwater exploration. Through the analysis of the requirements according to the scenario of underwater exploration, the mechanism of LARS and the conceptual design of the mechanical parts of LARS are carried out. In addition, a USV motion can be induced due to environmental disturbances such as waves, so the detailed design of LARS for recovering the underwater tow-fish stably in consideration of the USV motion is performed. To verify the performance of launch and recovery operations, LARS and test bed were developed. The results show that the proposed LARS can stably launch and recovery an underwater tow-fish.
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Design of INS Simulated Equipment for Evaluation of Enhanced Jamming Resistance of INS-aided GPS Receivers
정준우 Junwoo Jung , 박성열 Sungyeol Park , 안병선 Byoung-sun Ahn , 강행익 Haeng-ik Kang , 김갑진 Kap Jin Kim , 박영범 Youngbum Park
21(4) 339-346, 2017
정준우 Junwoo Jung , 박성열 Sungyeol Park , 안병선 Byoung-sun Ahn , 강행익 Haeng-ik Kang , 김갑진 Kap Jin Kim , 박영범 Youngbum Park
DOI: JANT Vol.21(No.4) 339-346, 2017
We propose the design of an INS simulated equipment to evaluate the enhanced jamming resistance of an INS-aided GPS receiver with INS, when a jamming signal is injected into a simulated high dynamic platform. We propose the design of a relative cheap INS simulated equipment, instead of an expensive INS simulator connected to GPS simulators. Based on the design, we implement the equipment and setup high dynamic test environment using the equipment to evaluate an INS-aided GPS receiver. In the GPS L1 C/A and L2C simulations that inject jamming signals of the narrow and wide bandwidth into the GPS receiver with and without INS-aided algorithm, we obtain increased jamming resistance performance as +5 dB compared with the GPS receiver without INS-aided algorithm in all kinds of jamming bandwidth. Based on the simulations, we verified that the INS simulated equipment can be used to evaluate the enhanced jamming resistance of INS-aided GPS receivers.
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Channel Allocation Using Mobile Mobility and Neural Net Spectrum Hole Prediction in Cellular-Based Wireless Cognitive Radio Networks
이진이 Jin-yi Lee
21(4) 347-352, 2017
이진이 Jin-yi Lee
DOI: JANT Vol.21(No.4) 347-352, 2017
In this paper, we propose a method that reduces mobile user`s handover call dropping probability by using cognitive radio technology(CR) in cellular - based wireless cognitive radio networks. The proposed method predicts a cell to visit by Ziv-Lempel algorithm, and then supports mobile user with prediction of spectrum holes based on CR technology when allocated channels are short in the cell. We make neural network predict spectrum hole resources, and make handover calls use the resources before initial calls. Simulation results show CR technology has the capability to reduce mobile user handover call dropping probability in cellular mobile communication networks.
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Miniaturization of UWB Antenna Using Open Ended Stepped Slot
이기용 Ki-yong Lee , 이영순 Young-soon Lee
21(4) 353-358, 2017
이기용 Ki-yong Lee , 이영순 Young-soon Lee
DOI: JANT Vol.21(No.4) 353-358, 2017
In order to reduce the size of the previous stepped slot antenna for UWB applications(3.1 ~ 10.6 GHz) to half, an open ended stepped slot antenna is proposed. The proposed antenna consists of a stepped slot etched on the ground plane as radiation part and a microstrip feed-line with rectangular patch on the top plane for wideband impedance matching. 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 28.5×32mm2. The measured impedance bandwidth (|11S≤ -10dB) of the fabricated antenna is 7.99 GHz(3.01~11 GHz) which is sufficient to cover UWB band (3.1 ~ 10.6 GHz). In particular, it has been observed that antenna has a good omnidirectional radiation patterns and high gain over the entire frequency band of interest even though the size of the proposed antenna is reduced to half when compared with the previous antenna.
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Interference Analysis for Deployment of the Efficient Village Broadcasting Radio System
강영흥 Young-heung Kang
21(4) 359-364, 2017
강영흥 Young-heung Kang
DOI: JANT Vol.21(No.4) 359-364, 2017
Since the existing analog village broadcasting system has some technical problems in applying and degradations in performance due to its old equipments, it had been required recently to be changed to a wireless digital system and to develop the standardization. However, it is important to analyze the interference between villages in deploying the efficient digital wireless village broadcasting system. In this paper, simulations for co-channel and adjacent channel interference have been carried out considering digital private mobile radio(dPMR) and digital mobile radio(DMR) systems as a representative mobile radio. These results for frequency reuse and channel separation drawn from the separation distance between villages in co-channel interference and the frequency offset in adjacent interference can be helpful to establish a standard and the testing service in the near future.
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Deep Learning Model for Electric Power Demand Prediction Using Special Day Separation and Prediction Elements Extention
박준호 Jun-ho Park , 신동하 Dong-ha Shin , 김창복 Chang-bok Kim
21(4) 365-370, 2017
박준호 Jun-ho Park , 신동하 Dong-ha Shin , 김창복 Chang-bok Kim
DOI: JANT Vol.21(No.4) 365-370, 2017
This study analyze correlation between weekdays data and special days data of different power demand patterns, and builds a separate data set, and suggests ways to reduce power demand prediction error by using deep learning network suitable for each data set. In addition, we propose a method to improve the prediction rate by adding the environmental elements and the separating element to the meteorological element, which is a basic power demand prediction elements. The entire data predicted power demand using LSTM which is suitable for learning time series data, and the special day data predicted power demand using DNN. The experiment result show that the prediction rate is improved by adding prediction elements other than meteorological elements. The average RMSE of the entire dataset was 0.2597 for LSTM and 0.5474 for DNN, indicating that the LSTM showed a good prediction rate. The average RMSE of the special day data set was 0.2201 for DNN, indicating that the DNN had better prediction than LSTM. The MAPE of the LSTM of the whole data set was 2.74% and the MAPE of the special day was 3.07 %.
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Performance Analysis and Equivalent Circuit Extraction for Magnetic Resonance Type Wireless Power Transfer
박대길 Dae Kil Park , 김영현 Young Hyun Kim , 구경헌 Kyung Heon Koo
21(4) 371-376, 2017
박대길 Dae Kil Park , 김영현 Young Hyun Kim , 구경헌 Kyung Heon Koo
DOI: JANT Vol.21(No.4) 371-376, 2017
In this paper, we propose a magnetic resonant WPT(wireless power transfer) scenario using a large coil resonating at 6.78 MHz, and compare the characteristics through a three-dimensional electromagnetic field simulation and a magnetic resonant WPT equivalent circuit. The magnetic resonant WPT equivalent circuit proposed in this paper considers the parasitic capacitance generated between the coils in addition to the conventional equivalent circuit. Based on this analysis, we fabricated the magnetic resonant WPT coil and compared it with simulation prediction. As a result of comparison, the transfer characteristics and the resonance frequency shift can be predicted. Error proposed characteristics of equivalent circuit for the magnetic resonant WPT and the measured values are estimated to be △|S11|=1.31 dB and △|S21|=1.21 dB, respectively.
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The Concentrating Photovoltaic System using a Solar Tracker
유영태 Yeong-tae Yoo , 나승권 Seung-kwon Na
21(4) 377-385, 2017
유영태 Yeong-tae Yoo , 나승권 Seung-kwon Na
DOI: JANT Vol.21(No.4) 377-385, 2017
The solar cell need the characteristic interpreting because the solar cell changes greatly according to the isolation, temperature and load in the photovoltaic development. Moreover, to get many energy in photovoltaic development need the position tracking of the sun according to the environment change. Also, The solar cells should be operated at the maximum power point. In this paper, I used microprocessor and sensor and designed to improve the efficiency of the photovoltaic system the photovoltaic position tracker device, and compared the normal photovoltaic system of fixed form with the photovoltaic system of solar position tracked form. Moreover, compared the catalogue of solar cell module and the simulation through a mathematics modelling with the solar cell`s characteristic interpreting and composed an power conversion system with boost converter and voltage source inverter. Used the constant voltage control method for maximum power point tracking in boost converter control and, used the SPWM(Sinusoidal Pulse Width Modulation) control method in inverter control. The result was less then 5% when compared the catalogue of solar cell module and the simulation through a mathematics modelling. The boost rate of boost converter was similar to 167 % with the simulation.
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UART-to-APB Interface Circuit Design for Testing a Chip
서영호 Young-ho Seo , 김동욱 Dong-wook Kim
21(4) 386-393, 2017
서영호 Young-ho Seo , 김동욱 Dong-wook Kim
DOI: JANT Vol.21(No.4) 386-393, 2017
Field programmable gate arrays (FPGAs) are widely used for verification in chip development. In order to verify the circuit programmed to the FPGA, data must be input to the FPGA. There are many ways to communicate with a chip through a PC and an external board, but the simplest and easiest way is to use a universal asynchronous receiver/transmitter (UART). Most recently, most circuits are designed to be internally connected to the advanced microcontroller bus architecture (AMBA) bus. In other words, to verify the designed circuit easily and simply, data must be transmitted through the AMBA bus through the UART. Also the AMBA bus has been available in various versions since version 4.0 recently. Advanced peripheral bus (APB) is suitable for simple testing. In this paper, we design a circuit for UART-to-APB interface. Circuits designed using Verilog-HDL were implemented in Altera Cyclone FPGAs and were capable of operating at speeds up to 380 MHz.
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Improvement of user experience and service value enhancement using Smart Mirror
오문석 Moon-seok Oh , 한규훈 Gyu-hoon Han , 최현준 Hyun-jun Choi , 서영호 Young-ho Seo
21(4) 394-401, 2017
오문석 Moon-seok Oh , 한규훈 Gyu-hoon Han , 최현준 Hyun-jun Choi , 서영호 Young-ho Seo
DOI: JANT Vol.21(No.4) 394-401, 2017
Smart Mirror is one of the representative technologies developed as a new communication method to escape the traditional technology by applying to the existing space. In this paper, we applied Smart Mirror to the beauty space to discover the service providing value needed to provide the beauty care service and to study the user experience for the value enhancement. In-depth interviews were conducted to investigate the user experience for enhancing the value of service provision. The results of analyzing the collected data using the affinity method were derived. Finally, the service value that can increase the user `s satisfaction through the focus group interview was suggested, which suggested a way to improve the user` s experience through the smart mirror.
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QoS-aware Fast Wakeup and Connection Mechanism on Broadcasting Convergence Network
김문 Moon Kim
21(4) 402-412, 2017
김문 Moon Kim
DOI: JANT Vol.21(No.4) 402-412, 2017
The convergence of broadcasting and telecommunication technologies is a key issue of the ubiquitous networks. So this paper offers the convergence of integrated telecommunication networks and broadcasting system, Advanced Terrestrial Digital Multimedia Broadcasting (AT-DMB), and the interconnection of them via the Media Independent Information Server/Service (MIIS). Then, this paper proposes the fast wakeup and connection mechanism with concepts for improving QoS and energy efficiency simultaneously. In the proposed convergence network, our mechanism places the key on the minimization of both the incoming service delay destined to a turned-off interface by using the broadcasting network and the additional energy consumption. This paper further evaluates the performance of proposed mechanism through the numerical and experimental analysis and has confirmed the decrease of both service delay and energy consumption.
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A Design Of Compact UHF Module With Double Structure That Can Receive Basic Type Link-K
민세홍 Se-hong Min , 김복기 Bok-ki Kim , 김강산 Kang-san Kim , 이종혁 Jong-hyuk Lee , 김종성 Jong-sung Kim , 배문관 Mun-kwan Bae , 김길훈 Kil-hun Kim , 이승필 Seoung-pil Lee
21(4) 413-421, 2017
민세홍 Se-hong Min , 김복기 Bok-ki Kim , 김강산 Kang-san Kim , 이종혁 Jong-hyuk Lee , 김종성 Jong-sung Kim , 배문관 Mun-kwan Bae , 김길훈 Kil-hun Kim , 이승필 Seoung-pil Lee
DOI: JANT Vol.21(No.4) 413-421, 2017
In this paper, we designed and fabricated a compact UHF receive module for efficient operation such as tactical and operation situation, target location information confirmation, target reset using Link-K(Korean joint tactical data link system). And the effect of target reset was analyzed by simulation. The designed module consists of UHF(ultra high frequency) receiver section, control section, and power distribution section. The UHF receiver section performs frequency down conversion, filtering and automatic gain control, etc. The control section demodulates frequency down-converted signals, extracts information, and performs external interworking. The power distribution section supplies external power, generates and supplies the power required by each section. The fabricated module was dimension of 105 x 105 x 80 mm and weighed 1.10 kg and The receiving distance is more than 50 km.
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