Development Trends of Small Satellites and Military Applications
이상현 Sanghyun Lee , 오재요 Jaeyo Oh , 권기범 Kyebeom Kwon , 이길영 Gil-young Lee , 조태환 Taehwan Cho
21(3) 213-219, 2017
이상현 Sanghyun Lee , 오재요 Jaeyo Oh , 권기범 Kyebeom Kwon , 이길영 Gil-young Lee , 조태환 Taehwan Cho
DOI: JANT Vol.21(No.3) 213-219, 2017
Large satellite development programs might take decades to build, launch and operate in space environments at costs in excess of a billion dollars. However, small satellites can reduce the costs not only by using commercial software and sensors, but also by shortening the development period to two years or less. In this paper, we discuss the development status of small satellites, and propose some military applications of small satellites. First, we describe the industrial trends of small satellites in advanced countries such as the United States and Japan. Also, we describe the development status of small satellites in Korea. Military applications are largely classified into education, research, and operational purposes. Small satellites are developing rapidly in commercial markets and they will play an important role in military sector. Therefore, the military should consider small satellites as important strategic assets in future conflicts and provide means to develop them.
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Dimming Control of the LED Luminaire Emergency Exit Sign Operation using a Hybrid Super Capacitor of DC-DC Convertor
황락훈 Lark-hoon Hwang , 김진선 Jin- Sun Kim , 나용주 Yong- Ju Na
21(3) 220-229, 2017
황락훈 Lark-hoon Hwang , 김진선 Jin- Sun Kim , 나용주 Yong- Ju Na
DOI: JANT Vol.21(No.3) 220-229, 2017
In this paper, To take advantage a variety of DC power as the boost DC-DC converter design specifications through the inductor L and capacitor C through PSPICE to calculate the best estimate of the value. Boost DC-DC converter with a switch device using IRF840 and reverse recovery time Schottky diodes with excellent with constant current controller using D10SC6M and resistance can be configured to considering the Power LED Module was driven by the production. Converter`s switching frequency is 50 kHz, the first Duty Rate was made to increase gradually depending on the value of the detection were, 10 % in the output voltage. As a result, the simulated Boost Power LED driver characteristics is in comparison with the design specifications, 5% or less as the error was approximated. Finally, when input 15 V were offered, a stable output 24 V were obtained. and Dimming Control through the adjustment of brightness and current consumption were possible.
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Historical Review for the Government Contractor Defense
신성환 Sung-hwan Shin
21(3) 230-242, 2017
신성환 Sung-hwan Shin
DOI: JANT Vol.21(No.3) 230-242, 2017
A significant rise in product-liability cost is expected due to the newly passed product liability amendment Bill approved during the assembly plenary session on March 30, 2017. Korean government legal service(KGLS) filed a damage suit against Korea aerospace industries, Ltd.(KAI) and Hanwha Techwin Co., Ltd., the manufactures of the KUH-1 Surion helicopter crashed . KGLS alleged claims under the product liability Act, the warrant liability Act and the non-performance of contract act. The accountability limits of military aircraft manufacturers was a highly divisive issue among related scholars and legal practitioners. The bottom line was that military aircraft manufacturers had no product-liability insurance available. The United States courts have, therefore, developed the government contractor defense(GCD) and it was recognized by the U.S. Supreme Court in Boyle v. United Technologies corporation(1988). product liability insurances for military aircraft manufacturers are excessively expensive and it cannot be added onto the military procurement cost accounting. However, having an aircraft accident without one can be ruinously expensive. Therefore, the manufacturers should promptly set up appropriate risk management measures. This thesis will first review the advance GCD theory, and then find a way to either reform government contract related regulations.
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The Spectral Domain K-median Threshold Filtering Method for the Dynamic GPS Interference Excision
김준오 Jun O Kim , 이상정 Sang Jeong Lee
21(3) 243-250, 2017
김준오 Jun O Kim , 이상정 Sang Jeong Lee
DOI: JANT Vol.21(No.3) 243-250, 2017
GPS(Global Positioning System) signal structure uses spread spectrum and the received power is relatively lower than the receiver noise figure. Therefore, it is vulnerable to the RF interferences and it could restrict on the safety navigation. The objective of this paper is to research on the spectral domain GPS interference rejection algorithm using proposed K-median filtering threshold setting method. In the performance test, the proposed algorithm has a relatively higher ISR(interference to signal ratio) compared with the conventional temporal domain technique in case of time variant interference signals.
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A Time Synchronization Scheme for Vision/IMU/OBD by GPS
임준후 Joonhoo Lim , 최광호 Kwang Ho Choi , 유원재 Won Jae Yoo , 김라우 La Woo Kim , 이유담 Yu Dam Lee , 이형근 Hyung Keun Lee
21(3) 251-257, 2017
임준후 Joonhoo Lim , 최광호 Kwang Ho Choi , 유원재 Won Jae Yoo , 김라우 La Woo Kim , 이유담 Yu Dam Lee , 이형근 Hyung Keun Lee
DOI: JANT Vol.21(No.3) 251-257, 2017
Recently, hybrid positioning system combining GPS, vision sensor, and inertial sensor has drawn many attentions to estimate accurate vehicle positions. Since accurate multi-sensor fusion requires efficient time synchronization, this paper proposes an efficient method to obtain time synchronized measurements of vision sensor, inertial sensor, and OBD device based on GPS time information. In the proposed method, the time and position information is obtained by the GPS receiver, the attitude information is obtained by the inertial sensor, and the speed information is obtained by the OBD device. The obtained time, position, speed, and attitude information is converted to the color information. The color information is inserted to several corner pixels of the corresponding image frame. An experiment was performed with real measurements to evaluate the feasibility of the proposed method.
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Effect of Regional Navigation Signals upon an Interference Cancellation Capable GNSS Receiver Performance
이장용 Jang-yong Lee , 장재규 Jae-gyu Jang , 안우근 Woo-guen Ahn , 서승우 Seung-woo Seo , 이상정 Sang-jeong Lee
21(3) 258-263, 2017
이장용 Jang-yong Lee , 장재규 Jae-gyu Jang , 안우근 Woo-guen Ahn , 서승우 Seung-woo Seo , 이상정 Sang-jeong Lee
DOI: JANT Vol.21(No.3) 258-263, 2017
This paper analyzed GNSS signal acquisition performance of a regional navigation receiver when an interference cancellation capability is applied. Intereference between the regional navigation and GNSS signal can be mitigated by the interference cancellation technique such as the successive interference cancellation (SIC) algorithm. However signal acquisition performance will be degraded when jamming-to-signal ratio (J/S) is large due to a cross-correlation properties of residual signals. In this paper we analyzed signal acquisition performance degradation due to the interference between the Kasami and GNSS Gold code signal. Monte Carlo simulation is used for the analysis and compared results with those of GNSS Gold code only condition.
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Aircraft 4D Trajectory Model for Air Traffic Control Simulator
정현태 Hyuntae Jung , 이금진 Keumjin Lee
21(3) 264-271, 2017
정현태 Hyuntae Jung , 이금진 Keumjin Lee
DOI: JANT Vol.21(No.3) 264-271, 2017
This paper presents air traffic control simulation model for generating 4D trajectory, and aircraft dynamic model based on 4D trajectory information. With aircraft parameters from BADA and Total Energy Model, the trajectory is defined through modified Bezier curve and the simulation supports two aircraft control methods based on controlled time of arrival (CTA) or airspeed. The simulation results shown that flight time and path were almost identical to the defined trajectory, and derived the differences of each control methods according to wind conditions. Based on the simulation model developed in this study, it is expected to be applied to various air traffic management researches. Future studies will focus on applying optimization techniques in order to minimize the difference between generated trajectories and actual flight routes. This work will increase utilization of developed simulation futhermore.
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Suggestion on the SBAS Augmentation Message Providing System for the the Low-cost GPS Receiver of Drone Operation
석효정 Hyo-jeong Seok , 윤동환 Dong-hwan Yoon , 임철순 Cheol-soon Lim , 박병운 Byung-woon Park
21(3) 272-278, 2017
석효정 Hyo-jeong Seok , 윤동환 Dong-hwan Yoon , 임철순 Cheol-soon Lim , 박병운 Byung-woon Park
DOI: JANT Vol.21(No.3) 272-278, 2017
In order to meet performance requirements specified by the ICAO in drone operation, a system that provides augmentation information such as SBAS is needed. However, the operating range of the drone is limited in situation where the drone can not received the SBAS message continuously. In this paper, we propose a system to transmit SBAS augmentation message using a separate communication channel assuming the SBAS satellite signal to the drone has been shielded. We implemented the proposed system and verified its performance in the static environment. The DGPS positioning results showed that the accuracy difference is about 10cm, which means the accuracy performance was very similar. In addition, the protection level calculated by the system also shows the difference within 2m from the value calculated by the airborne receiver.
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Comparative Analysis of Performance for DGPS and SBAS in Korea Region
임철순 Cheol-soon Lim , 박병운 Byung-woon Park
21(3) 279-286, 2017
임철순 Cheol-soon Lim , 박병운 Byung-woon Park
DOI: JANT Vol.21(No.3) 279-286, 2017
The international maritime organization(IMO) has defined performance requirements for future maritime navigation through IMO resolution A.915(22) in 2001. Many DGPS systems currently providing DGPS services do not meet the performance requirements specified in IMO resolution A.915(22). The use of SBAS is considered as one of the DGPS replacement and supplementary system for coping with the increase in demand performance and providing safe positioning service. In particular, since a large amount of budget is required to rearrange the existing DGPS reference stations, a method which transmits differential corrections generated by using SBAS message has been proposed. In this paper, we compare and analyze the performance of NDGPS which is operated by the National Maritime PNT Office of the ministry of oceans and fisheries(MOF) in Korea and MSAS in Japan. Also, we verify that SBAS, as alternative and complementary system, meets the performance requirement specified in IMO resolution A.915(22).
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Unequal Bagley Divider based on Uniform Characteristic Impedance Transmission Lines with Adjustment Electrical Lengths
윤영철 Young-chul Yoon , 홍성욱 Soung-wook Hong , 김영 Young Kim
21(3) 287-293, 2017
윤영철 Young-chul Yoon , 홍성욱 Soung-wook Hong , 김영 Young Kim
DOI: JANT Vol.21(No.3) 287-293, 2017
This paper describes an unequal Bagley divider using uniform transmission lines with adjustment electrical lengths between output ports. To obtain an arbitrary dividing ratio of Bagley divider, we have only adjusted the electrical lengths of the transmission line between output ports. All the transmission lines have the same characteristic impedance value. This design method does not require an impedance transformer for port matching. For verification, we simulated and fabricated a 3-way, 1:2:1 and 5-way, 2:3:4:3:2 ratio Bagley divider with an operating frequency of 2 GHz. The experimental results are in agreement with the simulated results.
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Implementation of Intelligent Home Network System using Wireless Sensor
주재한 Jae-han Ju , 나승권 Seung-kwon Na
21(3) 294-299, 2017
주재한 Jae-han Ju , 나승권 Seung-kwon Na
DOI: JANT Vol.21(No.3) 294-299, 2017
Home network service is evolving into a service that can receive contents such as remote education, home automation, remote meter reading and various entertainment anytime and anywhere by connecting all household appliances in home with wired and wireless network. In this paper, an intelligent home gateway installed at home is connected to the mobile communication terminal from the outside to solve the problems of the existing home network and configure and maintain a more efficient and comfortable home network environment for the user, In the window, the login page is activated to confirm the user access authority, and the user proceeds the authentication procedure through own login information. When the normal authentication procedure is performed, the intelligent home gateway maintains only the network connection with the user, and the user presents the intelligent home network system using the RFID which is accessed by the intelligent home network system.
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Implementation of Self Diagnostics Low-power Embedded Linux System using Telematics
주재한 Jae-han Ju
21(3) 300-305, 2017
주재한 Jae-han Ju
DOI: JANT Vol.21(No.3) 300-305, 2017
It is necessary to establish a system suitable for the driving vehicle so that it can effectively search for and modify various data anywhere and anytime by effectively linking communication with the computer system in the running vehicle and to control the equipment properly for smooth operation on a limited platform do. Also, vehicle CAN communication is used to extract system engine information, and data is transmitted using ZigBee for this information transmission. Therefore, OBD-II protocol, which is provided by the vehicle itself, is used for vehicle CAN to obtain vehicle status information and exhaust gas using various sensor information of the vehicle and O2 sensor value, and transmits it to the ZigBee main control system.
In this study, we implemented a system that can reduce the battery load damage to the maximum by reducing the power consumption to the maximum, and to monitor the internal state of the vehicle through ZigBee communication with the embedded system for low power vehicles.
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The Method of Data Integration based on Maritime Sensors using USN
홍성화 Sung-hwa Hong , 고재필 Jae-pil Ko , 곽재민 Jae-min Kwak
21(3) 306-311, 2017
홍성화 Sung-hwa Hong , 고재필 Jae-pil Ko , 곽재민 Jae-min Kwak
DOI: JANT Vol.21(No.3) 306-311, 2017
In the future ubiquitous network, information will collect data from various sensors in the field. Since the sensor nodes are equipped with small, often irreplaceable, batteries with limited power capacity, it is essential that the network be energy-efficient in order to maximize its lifetime. In this paper, we propose an effective network routing method that can operate with low power as well as the transmission of data and information obtained from sensor networks, and identified the number of sensors with the best connectivity to help with the proper placement of the sensor. These purposes of this research are the development of the sensor middle-ware to integrate the maritime information and the proposal of the routing algorithm for gathering the maritime information of various sensors. In addition, for more secure ship navigation, we proposed a method to construct a sensor network using various electronic equipments that are difficult to access in a ship, and then construct a communication system using NMEA(the national marine electronics association), a ship communication standard, in the future.
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