Advanced Estimation Model of Runway Visual Range using Deep Neural Network
구성관 Sungkwan Ku , 박창환 Changhwan Park , 홍석민 Seokmin Hong
22(6) 491-499, 2018
구성관 Sungkwan Ku , 박창환 Changhwan Park , 홍석민 Seokmin Hong
DOI: JANT Vol.22(No.6) 491-499, 2018
Runway visual range (RVR), one of the important indicators of aircraft takeoff and landing, is affected by meteorological conditions such as temperature, humidity, etc. It is important to estimate the RVR at the time of arrival in advance. This study estimated the RVR of the local airport after 1 hour by upgrading the RVR estimation model using the proposed deep learning network. To this end, the advancement of the estimation model was carried out by changing the time interval of the meteorological data (temperature, humidity, wind speed, RVR) as input value and the linear conversion of the results. The proposed method generates estimation model based on the past measured meteorological data and estimates the RVR after 1 hour and confirms its validity by comparing with measured RVR after 1 hour. The proposed estimation model could be used for the RVR after 1hour as reference in small airports in regions which do not forecast the RVR.
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A Calculation Method for the Tilt Angle of Missile Round using Roll Rotation
박동현 Dong-hyun Park
22(6) 500-506, 2018
박동현 Dong-hyun Park
DOI: JANT Vol.22(No.6) 500-506, 2018
In this paper, we considered the one-shot alignment using master inertial navigation system (MINS) and slave inertial navigation system (SINS) in the missile to find the exact posture of a missile. In order to perform one-shot alignment, the tilt angle between MINS and SINS must be obtained, which can be compensated by obtaining the tilt angle between missile round and SINS. The tilt angle was calculated by using the roll rotation of missile round, jig for rotating the missile round and interface structure to measure the horizontal state by using a horizontal angle meter were constructed. As a result of the tilt angle save (TAS) inspection, the tilt angle α, β, γ is normal range and it is possible to perform one-shot alignment by compensating this value.
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Analysis and Design of Common Platform Core Technology for Maritime Autonomous Surface Ships
정성훈 Seong-hoon Jeong , 심준환 Joon-hwan Shim , 최관선 Kwan-seon Choi , 손영창 Young-chang Son
22(6) 507-513, 2018
정성훈 Seong-hoon Jeong , 심준환 Joon-hwan Shim , 최관선 Kwan-seon Choi , 손영창 Young-chang Son
DOI: JANT Vol.22(No.6) 507-513, 2018
The maritime autonomous surface ship is automatically collects and manages various information necessary for the operation to minimize human intervention and safely perform the mission assigned to the ship. And the ship may autonomously operate the partial or entire route to the destination determined by the ship himself. This ship navigation technology allows partially remote control the ship to be operated if necessary. The maritime autonomous surface ship (MASS) should collect and manage signals of various navigation communication equipments and engines mounted on the ship for safe operation. This requires a common platform technology. In this paper, we propose a common platform that is the core of smart ship implementation. Territorial authorities and ships are connected by satellite or terrestrial communication. In such a communication environment, information is exchanged smoothly in real time. This allows the onshore authorities to monitor ships and provide remote control to enable safe vessel navigation at sea.
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Analysis of COSPAS-SARSAT 406 MHz Personal Locator Beacon Specification
정기룡 Gi-ryong Jeong , 정성훈 Seong-hoon Jeong , 임종근 Jong-gun Lim
22(6) 514-521, 2018
정기룡 Gi-ryong Jeong , 정성훈 Seong-hoon Jeong , 임종근 Jong-gun Lim
DOI: JANT Vol.22(No.6) 514-521, 2018
COSPAS-SARSAT 406 ㎒ emergency beacons include ELTs for aviation, EPIRBs for maritime, and PLBs for individuals in distress. They are used to sending messages encoded on 406 ㎒ distress frequency and sending alerts for search and rescue in distress. C/S T.001 and T.018 are COSPAS-SARSAT technical documents. They include basic technical information needed for developing beacons, how messages are constructed, and test methods for type approval. COSPAS-SARSAT systems that use existing low earth orbit (LEO) and geostationary earth orbit (GEO) satellites do not have a return link service (RLS). So, the survivors could not confirm whether the distress signal was sending or not. However, a new medium earth orbit (MEO) satellite system has been added to this system, allowing confirmation through the RLS function. This paper analyzed C/S T.001 and T.018 needed to develop navigation structures that incorporated improved PLB of 406 ㎒, a homing signal generator of 121.5 ㎒, and a VHF AM transmitter for aviation of 243 ㎒.
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Experiment on Automatic Detection of Airport Debris (FOD) using EO/IR Cameras and Radar
홍재범 Jae-beom Hong , 강민수 Min-soo Kang , 김윤섭 Yun-seob Kim , 김민수 Min-soo Kim , 홍교영 Gyo-young Hong
22(6) 522-529, 2018
홍재범 Jae-beom Hong , 강민수 Min-soo Kang , 김윤섭 Yun-seob Kim , 김민수 Min-soo Kim , 홍교영 Gyo-young Hong
DOI: JANT Vol.22(No.6) 522-529, 2018
FOD refers to various metals and non-metallic foreign substances that pose a risk to aircraft. FODs occur in all areas and time zones, including runways, taxiways, and maintenance facilities, and pose a fatal hazard to aircraft safety during aircraft movements and take-off and landing. Rapid and effective detection and removal of FODs in the runway is required. As part of recent developments in aviation safety technologies, automatic detection of debris in runways in airports is under way. In this paper, we conducted an automated detection test using the EO/IR camera and radar at the Taean campus of Hansu University to confirm normal detection during the day and night.
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Feasibility Study on the Methodology of Test and Evaluation for UAV Positioning
주요한 Yo-han Ju , 문경환 Kyung-kwan Moon , 강봉석 Bong-seok Kang , 정재원 Jae-won Jeong , 손한기 Han-gi Son , 조정현 Jeong-hyun Cho
22(6) 530-536, 2018
주요한 Yo-han Ju , 문경환 Kyung-kwan Moon , 강봉석 Bong-seok Kang , 정재원 Jae-won Jeong , 손한기 Han-gi Son , 조정현 Jeong-hyun Cho
DOI: JANT Vol.22(No.6) 530-536, 2018
Recently, many studies for interoperability of UAV in the NAS has been performed since the application range and demand of UAV are continuously increased. For the interoperation of UAV in the NAS, technical standards and certification system for UAV which is equivalent to the commercial aircraft are required and test and evaluation methodology must be presented by standards. In this paper, qualification test and evaluation methodology aboutfor the UAV navigation system is proposed. For the research, the mission profile and operation environment of UAV were analyzed. Thereafter the test criteria were derived and the test methodology were established. Finally, the simulation and demonstration using test-bed UAV were performed. As a result of the test, it was confirmed that the navigation system of test UAV has a position accuracy about 1.4 meters at 95% confidence level in the entire flight stage.
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Flight Test Safety Risk Assessment and Mitigation
김무근 Mu-geun Kim , 유병선 Beong-seon Yoo , 한정호 Jeongho Han , 강자영 Ja-young Kang
22(6) 537-544, 2018
김무근 Mu-geun Kim , 유병선 Beong-seon Yoo , 한정호 Jeongho Han , 강자영 Ja-young Kang
DOI: JANT Vol.22(No.6) 537-544, 2018
A national comprehensive aviation test center is being constructed for the purpose of flight tests for development and modification of aircraft or flight inspections for the development of navaids. Flight testing is a high-risk task, so strict risk management processes are required prior to operation. In addition, since the flight test center is subject to the airdrome regulations under the current law, the introduction of the safety management system will enhance safety as usual in ordinary airports. The establishment of a safety management system based on ICAO criteria is an optimal means of ensuring safe and effective operation of the test center and may mitigate the risks that may arise during flight testing. This paper focuses on risk assessment and mitigation required for safety management at the flight test center. We conducted risk assessments on the flight hazards identified in the previous study. Then the high risk group of hazards were selected and risk mitigation techniques such as avoidance, reduction, acceptance, and control were applied.
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Power Save of Marine Tracker Buoy System Based on NB-IoT for Identification of Fishing Gear
남성일 Sung-il Nam , 김민훈 Min-hoon Kim
22(6) 545-550, 2018
남성일 Sung-il Nam , 김민훈 Min-hoon Kim
DOI: JANT Vol.22(No.6) 545-550, 2018
Ministry of Oceans and Fisheries declared action plan for the electric fishing gear using real name in order to prevent overusing the fishing gear and to reduce discarded fishing gear. It is needed for a technique that can efficiently transmit the information including the type and location of the fishing gear and the user's real name to the fishing boat and the control center using IoT-based communication. The marine tracker buoy system, which is placed on the water for a long time, transmit the position data and the state data of the buoys to the control center in the ground by using NB-IoT channels. In this paper, we propose the algorithm for the low-power operation of the marine tracker buoy system is proposed and test results of current consumption in the marine tracker buoy system with the proposed algorithm is investigated.
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Flow Analysis and Flight Experiment for Optimum Height of Weather Data Sensor
김영인 Young-in Kim , 구성관 Sungkwan Ku , 박창환 Changhwan Park
22(6) 551-556, 2018
김영인 Young-in Kim , 구성관 Sungkwan Ku , 박창환 Changhwan Park
DOI: JANT Vol.22(No.6) 551-556, 2018
In recent years, drones have been used to measure aircraft flights data and weather information. Related applications include the measure for low-altitude atmospheric data, the measure for atmospheric fine dust, and the measure for air pollution. However, the mounting position of the atmospheric measurement sensor should be mounted by considering the effects of propeller flow, the EMI effects, and the changes in the weight of the drone. Among these, the upper flow of the propeller affects the wind speed and direction, so the optimal position should be selected. This study deals with the proper height of the atmospheric data measurement sensor. Through the flow analysis, we study the flow characteristics of around a drone and suggest the proper sensor mounting height.
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A Novel Short Delay Multipath Mitigation Algorithm for a GNSS based Land Vehicle in Urban Environment
임덕원 Deok Won Lim , 천세범 Sebum Chun , 허문범 Moon Beom Heo
22(6) 557-565, 2018
임덕원 Deok Won Lim , 천세범 Sebum Chun , 허문범 Moon Beom Heo
DOI: JANT Vol.22(No.6) 557-565, 2018
For GNSS navigation in urban environment, a novel short delay multipath mitigation algorithm is proposed in this paper. This algorithm detects which satellite's signal is the multipath signal by using the constraint that GNSS receiver is equipped in a ground vehicle, then estimate new position after separating the measurement of that satellite. A criterion for detecting and validating the multipath signal depends on the performance grade of the GNSS receiver and the dynamics of the vehicle. In order to evaluate the proposed algorithm, the real data had been collected at the multipath environment of 4 scenarios. By post-processing the real data with both of the multipath mitigation algorithm in the receiver and the proposed algorithm, it can be checked that the position errors were less than 5 meters except the case that the number of visible satellite is lower than 5.
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Test and Evaluation for GNSS based Lane Level Precise Positioning User Syste
이정훈 Jung-hoon Lee , 이상우 Sangwoo Lee , 안종선 Jongsun Ahn , 임성혁 Sunghyuck Im , 최윤성 Yunseong Choi , 장영수 Youngsu Jang , 이동철 Dongchul Lee , 허문범 Moon-beom Heo
22(6) 566-576, 2018
이정훈 Jung-hoon Lee , 이상우 Sangwoo Lee , 안종선 Jongsun Ahn , 임성혁 Sunghyuck Im , 최윤성 Yunseong Choi , 장영수 Youngsu Jang , 이동철 Dongchul Lee , 허문범 Moon-beom Heo
DOI: JANT Vol.22(No.6) 566-576, 2018
The C-ITS requires the lane level positioning of the vehicle in the land transportation environment, and it is most effective to utilize the GNSS. In the precision positioning system based on satellite navigation, the evaluation of dynamic environment of lane level positioning performance should be accompanied and the evaluation system configuration should be preceded. In this paper, we selected performance indicators, assessment equipment, and reliability of reference equipment for evaluation of precision positioning user systems based on the GNSS. The performance evaluation system described above is applied to a real system, and the performance evaluation tool developed for the evaluation system is described. The numerical performance evaluation was carried out based on the data collected by carrying out the actual testbed driving. The performance evaluation by the actual driving trajectory and driving image comparison was performed to derive and analyse the evaluation results of the vehicle lane level positioning user system.
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National-Wide NETPPI-LT Cluster Design using CORS
신미리 Miri Shin , 안종선 Jongsun Ahn , 손은성 Eunseong Son , 허문범 Moon-beom Heo
22(6) 577-584, 2018
신미리 Miri Shin , 안종선 Jongsun Ahn , 손은성 Eunseong Son , 허문범 Moon-beom Heo
DOI: JANT Vol.22(No.6) 577-584, 2018
GNSS based transport infrastructure cluster is to broadcast satellite navigation correction information and integrity information capable of precise positioning for land transport users. This makes it possible to do lane-level positioning reliably. However, in order to provide the lane-level positioning and correction information service nationwide, new station sites selection and to build GNSS stations have a heavy cost and a burden for a considerable period of time. In this paper, we propose the cluster design criteria and national-wide network-based precise positioning for land transportation (NETPPI-LT) cluster design for a cluster-based precise positioning. Furthermore, it is analyzed the precise positioning pre-performance of this cluster design based on the spatial error and verified its suitability as the precise positioning pre-performance of the cluster design.
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Solar Radiation Pressure Model Comparison for GPS Satellites
유선경 Sunkyoung Yu , 김강호 Ghangho Kim , 기창돈 Changdon Kee , 허문범 Moon-beom Heo
22(6) 585-590, 2018
유선경 Sunkyoung Yu , 김강호 Ghangho Kim , 기창돈 Changdon Kee , 허문범 Moon-beom Heo
DOI: JANT Vol.22(No.6) 585-590, 2018
GPS satellite orbits could be estimated precisely using GPS dynamics as well as GPS observations. Most of the perturbations are available to be generated using satellite position, velocity, well known model equations and coefficients. However, who wants to calculate solar radiation pressure (SRP) should choose a SRP model and estimate the coefficients of a SRP model. The accuracy of SRP model depends on the model characteristics. Therefore this paper has estimated coefficients of SRP models using CODE precise orbit product and compared the accuracy of orbit propagator depending on SRP model. The results show that the extended CODE orbit model (ECOM) and the reduced ECOM achieved cm level fitting orbit for the CODE 1-day orbit. Also orbit propagation model without SRP model consideration could get tens of meter orbits compared to CODE orbits.
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An Integrated Operation/Evaluation System Development for Lane-Level Positioning Based on GNSS Networks
이상우 Sangwoo Lee , 임성혁 Sunghyuk Im , 안종선 Jongsun Ahn , 손은성 Eunseong Son , 신미리 Miri Shin , 이정훈 Jung-hoon Lee , 허문범 Moon-beom Heo
22(6) 591-601, 2018
이상우 Sangwoo Lee , 임성혁 Sunghyuk Im , 안종선 Jongsun Ahn , 손은성 Eunseong Son , 신미리 Miri Shin , 이정훈 Jung-hoon Lee , 허문범 Moon-beom Heo
DOI: JANT Vol.22(No.6) 591-601, 2018
This paper discusses methods to effectively operates and evaluates an infrastructure system for lane-level positioning based on satellite navigation. The lane-level positioning infrastructure provides correction information on range measurements with integrity information on the correction to a user with a single frequency (cheap) satellite navigation receiver in order to perform lane-level positioning and integrity monitoring on the position estimate. The architecture and configuration of the lane-level positioning system are described from the systematic level in order to provide a comprehensive insight of the system. The operation/evaluation system for the integrated infrastructure is then presented. The evaluation results of the real implemented system are provided. Based on the results, we discuss requirements to increase the system stability from the operation perspective.
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Predict DGPS Algorithm using Machine Learning
김홍표 Hongpyo Kim , 장진혁 Jinhyeok Jang , 구상훈 Sanghoon Koo , 안종선 Jongsun Ahn , 허문범 Moon-beom Heo , 성상경 Sangkyung Sung , 이영재 Young Jae Lee
22(6) 602-609, 2018
김홍표 Hongpyo Kim , 장진혁 Jinhyeok Jang , 구상훈 Sanghoon Koo , 안종선 Jongsun Ahn , 허문범 Moon-beom Heo , 성상경 Sangkyung Sung , 이영재 Young Jae Lee
DOI: JANT Vol.22(No.6) 602-609, 2018
Differential GPS (DGPS) is known as a positioning method using pseudo range correction (PRC) which is communicating between a refence receiver and moving receivers. In real world, a moving receiver loses communication with the reference receiver, resulting in loss of PRC real-time communication. In this paper, we assume that the transmission of the pseudo range correction is interrupted in the middle of real-time positioning situations, in which calibration information is received in the DGPS method. Under the disconnected communication, we propose ‘predict DGPS’ that real-time virtual PRC model which is modeled by a machine learning algorithm with previously acquired PRC data from a reference receiver. To verify predict DGPS method, we compared and analyzed positioning solutions acquired from real PRC and the virtual PRC. In addition, we show that positioning using the DGPS prediction method on a real road can provide an improved positioning solution assuming a scenario in which PRC communication was cut off.
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Analysis of Satellite Visibility and High Elevation Satellite using GPS and Beidou in Korea
장진혁 Jinhyeok Jang , 김홍표 Hongpyo Kim , 안종선 Jongsun Ahn , 허문범 Moon-beom Heo , 성상경 Sangkyung Sung , 이영재 Young Jae Lee
22(6) 610-615, 2018
장진혁 Jinhyeok Jang , 김홍표 Hongpyo Kim , 안종선 Jongsun Ahn , 허문범 Moon-beom Heo , 성상경 Sangkyung Sung , 이영재 Young Jae Lee
DOI: JANT Vol.22(No.6) 610-615, 2018
Globally, global navigation satellite system (GNSS) is being developed and operated in advanced countries. China's Beidou is developing rapidly, starting with global positioning system (GPS), which is the most representative system. In this paper, we analyze the visibility of Beidou satellite in Korea at present time to utilize rapidly changing Beidou. In this analysis, it is compared with GPS which is stable service. The results of the visibility analysis are based on the results of the mask angle (the low elevation satellite exclusion angle) and the result of the skyplot (a visual representation of the position of the satellite at the user location). Visibility analysis shows that the high elevation angle of Beidou satellite is higher than that of GPS satellite in Korea. In addition, GPS and Beidou's availability and positioning accuracy analysis are performed to confirm the effect of increasing elevation angle satellites. According to the results, Beidou is more effective than GPS in using high elevation satellites in Korea.
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Analysis of Frequency of Seismogenic Ionospheric Disturbance by using GNSS Signal
김부겸 Bu-gyeom Kim , 강선호 Seon-ho Kang , 한덕화 Deok-hwa Han , 송준솔 June-sol Song , 기창돈 Chang-don Kee
22(6) 616-622, 2018
김부겸 Bu-gyeom Kim , 강선호 Seon-ho Kang , 한덕화 Deok-hwa Han , 송준솔 June-sol Song , 기창돈 Chang-don Kee
DOI: JANT Vol.22(No.6) 616-622, 2018
Energy which is released by a huge earthquake can reach the ionosphere and induce disturbances. Those disturbances can detected by analyzing the global navigation satellite system (GNSS) satellite’s signal. For detecting those disturbances, band-pass filter is generally used. Therefore, it is important to select proper pass band that can contain disturbance’s frequency. In this paper, we analyzed a frequency of the ionospheric disturbances which are induced by earthquake by using GNSS signal. For analyzing seismogenic ionospheric disturbances, we calculated a geometry free combination of carrier phase to obtain a ionospheric delay. After that, the fast Fourier transform was applied to the 1 mHz high-passed ionospheric delay. As a result of analyzing disturbances, the frequency band of earlier disturbances was 4.5 mHz~11mHz and the representative frequency was 5.7 mHz. The frequency band of subsequent disturbances was 6 mHz~10 mHz and the representative frequency was 7.3 mHz.
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Real-time Obstacle Detection and Avoidance Path Generation Algorithm for UAV
고하윤 Ha-yoon Ko , 백중환 Joong-hwan Baek , 최형식 Hyung-sik Choi
22(6) 623-629, 2018
고하윤 Ha-yoon Ko , 백중환 Joong-hwan Baek , 최형식 Hyung-sik Choi
DOI: JANT Vol.22(No.6) 623-629, 2018
In this paper, we propose a real-time obstacle detection and avoidance path generation algorithm for UAV. 2-D Lidar is used to detect obstacles, and the detected obstacle data is used to generate real-time histogram for local avoidance path and a 2-D SLAM map used for global avoidance path generation to the target point. The VFH algorithm for local avoidance path generation generates a real-time histogram of how much the obstacles are distributed in the vector direction and distance, and this histogram is used to generate the local avoidance path when detecting near fixed or dynamic obstacles. We propose an algorithm, called modified RRT*-Smart, to overcome existing limitations. That generates global avoidance path to the target point by creating lower costs because nodes are checked whether or not straight path to a target point, and given arbitrary lengths and directionality to the target points when nodes are created. In this paper, we prove the efficient avoidance maneuvering through various simulation experiment environment by creating efficient avoidance paths.
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Stability Condition of Discrete System with Time-varying Delay and Unstructured Uncertainty
한형석 Hyung-seok Han
22(6) 630-635, 2018
한형석 Hyung-seok Han
DOI: JANT Vol.22(No.6) 630-635, 2018
In this paper, we consider the stability condition for the linear discrete systems with time-varying delay and unstructured uncertainty. The considered system has time invariant system matrices for non-delayed and delayed state variables, but its delay time is time-varying within certain interval and it is subjected to nonlinear unstructured uncertainty which only gives information on uncertainty magnitude. In the many previous literatures, the time-varying delay and unstructured uncertainty can not be dealt in simultaneously but separately. In the paper, new stability conditions are derived for the case to which two factors are subjected together and compared with the existing results considering only one factor. The new stability conditions improving many previous results are proposed as very effective inequality equations without complex numerical algorithms such as LMI(Linear Matrix Inequality) or Lyapunov equation. By numerical examples, it is shown that the proposed conditions are able to include the many existing results and have better performances in the aspects of expandability and effectiveness.
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Design of Wireless Data Transmission and Web Logging System
노재성 Jae-sung Roh
22(6) 636-641, 2018
노재성 Jae-sung Roh
DOI: JANT Vol.22(No.6) 636-641, 2018
In recent years, the Internet of things has grown rapidly and is being used in many fields. The function of an Internet device is to collect information in various environments and to provide useful information to users. Due to recent developments in technology, the kinds of Internet devices are increasing and the prices are getting cheaper. In addition, many open source platforms that are easy to use have been developed and are providing convenience to users. In this paper, wireless data transmission and cloud server system based on ESP-12E NodeMCU module was designed and sensor information collected from Internet devices was transmitted to cloud server through WiFi wireless communication. The collected sensor data was saved by creating channel and field in the cloud server and the data of each field was visualized as a graph.
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Unequal Power Divider based on Adjustment Electrical Length of Uniform Transmission Line
권상근 Sang-keun Kwon , 김영 Young Kim
22(6) 642-647, 2018
권상근 Sang-keun Kwon , 김영 Young Kim
DOI: JANT Vol.22(No.6) 642-647, 2018
In this paper, an unequal power divider based on adjusting electrical length of uniform transmission line is presented. This divider consists of three uniform transmission lines and one isolation resistor and have the different port impedances of input and output. The feature of proposed divider can changed the power dividing ratio to adjust only electrical length of uniform transmission lines. To verify the feasibility of proposed power divider, two divider circuits are designed, one is 1:2 power dividing ratio divider with 60 Ω uniform transmission line and 40 Ω input port impedances and 45 Ω output port impedances, the performance data were measured the insertion losses of 1.7 dB/ 5.0 dB, return losses of more than -30 dB and isolation of more than -35 dB. The other is 1:4 power dividing ratio divider with 40 Ω uniform transmission line and 50 Ω input port impedances and 75 Ω output port impedances, the performance data were measured the insertion losses of 1.3 dB/ 6.8 dB, return losses of more than -12 dB and isolation of more than -19 dB. The measured performance data agreed well with the simulated results.
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Pair Correlation Analysis of Reaction-Diffusion Halftoning
조청운 Chueng-woon Jho
22(6) 648-653, 2018
조청운 Chueng-woon Jho
DOI: JANT Vol.22(No.6) 648-653, 2018
Analysis of a specific wavelength band of a video signal is an old research field. However, studies on the analysis of signals having the characteristics of a specific wavelength band or the generation of samples have been conducted actively in recent years. In this paper, we analyze the signal of digital halftoned image. The interpretation of halftoning in terms of signals was first made by Ulichney. We have come to the view that the signal characteristics between pixels used for half toning are good for blue noise. Lau has developed a halftoning method that uses green-noise characteristics by using output-dependent feedback as an error diffusion method. Jho has developed a method for producing halftoned images using a reaction diffusion model. In this paper, we analyze reaction diffusion halftoning in terms of signal to show green noise and compare it with existing green noise half tone.
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Characteristic PCS of Inverter by Boost Converter of PV Generation
황락훈 Lark-hoon Hwang , 나승권 Seung-kwon Na , 오상학 Sang-hak Oh
22(6) 654-664, 2018
황락훈 Lark-hoon Hwang , 나승권 Seung-kwon Na , 오상학 Sang-hak Oh
DOI: JANT Vol.22(No.6) 654-664, 2018
In this paper, this system is operated by PCS that is driven by being synchronized voltage fed inverter and AC source, and in the steady state of power source charge battery connected to DC side with solar cell using a photovoltaic (PV) that it was so called constant voltage charge. it can cause the effect of energy saving of electric power, from 10 to 20%. and through a normal operation of electric energy storage system (EESS). In addition, better output waveform was generated because of pulse width modulation (PWM) method, and it was Proved to test by experiment maintained constant output voltage regardless of AC source disconnection, load variation, and voltage variation of AC power source.
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Dual-Band Antenna Design for LTE/Wi-Fi for Maritime Broadband Communication
오말근 Mal-geun Oh
22(6) 665-669, 2018
오말근 Mal-geun Oh
DOI: JANT Vol.22(No.6) 665-669, 2018
In this paper, we design an antenna for LTE / Wi-Fi communication that operates in 2.65 GHz and 5 GHz band for small-sized broadband communication antenna that can be used in the sea. Microstrip patch antennas were chosen to improve the bandwidth. The slot width, length, and transmission line width were calculated using the theoretical formula for each step. In addition, we designed a microstrip antenna using CST Microwave Studio 2014 program that can design 3D. Simulation results show that the reflection loss is -12.712 dB at 2.65 GHz and -16.583 dB at 5 GHz. The gain was 1.738 dBi at 2.65 GHz and 3.284 dBi at 5 GHz. In this paper, we propose a dual-band antenna for LTE / Wi-Fi, which can be used in maritime environments, which is worse than terrestrial communication, because of differences in communication speed and communication stability compared with those used on land.
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Cultural Region-based Clustering of SNS Big Data and Users Preferences Analysis
노승민 Seungmin Rho
22(6) 670-674, 2018
노승민 Seungmin Rho
DOI: JANT Vol.22(No.6) 670-674, 2018
Social network service (SNS) related data including comments/text, images, videos, blogs, and user experiences contain a wealth of information which can be used to build recommendation systems for various clients’ and provide insightful data/results to business analysts. Multimedia data, especially visual data like image and videos are the richest source of SNS data which can reflect particular region, and cultures values/interests, form a gigantic portion of the overall data. Mining such huge amounts of data for extracting actionable intelligence require efficient and smart data analysis methods. The purpose of this paper is to focus on this particular modality for devising ways to model, index, and retrieve data as and when desired.
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Design and Implementation of Hand Gesture Recognizer Based on Artificial Neural Network
김민우 Minwoo Kim , 정우재 Woojae Jeong , 조재찬 Jaechan Cho , 정윤호 Yunho Jung
22(6) 675-680, 2018
김민우 Minwoo Kim , 정우재 Woojae Jeong , 조재찬 Jaechan Cho , 정윤호 Yunho Jung
DOI: JANT Vol.22(No.6) 675-680, 2018
In this paper, we propose a hand gesture recognizer using restricted coulomb energy (RCE) neural network, and present hardware implementation results for real-time learning and recognition. Since RCE-NN has a flexible network architecture and real-time learning process with low complexity, it is suitable for hand recognition applications. The 3D number dataset was created using an FPGA-based test platform and the designed hand gesture recognizer showed 98.8% recognition accuracy for the 3D number dataset. The proposed hand gesture recognizer is implemented in Intel-Altera cyclone IV FPGA and confirmed that it can be implemented with 26,702 logic elements and 258Kbit memory. In addition, real-time learning and recognition verification were performed at an operating frequency of 70MHz.
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