• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.77-80
• /
• 2010

The demand for human security significantly promotes the development of surveillance applications using a multi-sensor integrated UAV system. For more sophisticated operations, the system should provide a sequence of images rectified in a ground coordinate system in realtime. This rectification requires accurate position and attitude of the camera at the time of exposure of each image, which can be estimated through an Aerial Triangulation process using the GPS/INS data and tie points between adjacent images. In this work, the KLT tracker is utilized to obtain the tie points. To satisfy the realtime requirements, we present an approach to speed up the tracker by supplying the initial guessed positions of tie points based on the exterior orientation. The experimental results show that, when the guessed positions are supplied, the KLT tracker consumed less computational time than the ordinary KLT which is more suitable to be incorporated into the realtime image georeferencing process.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.8 no.3 s.22
• /
• pp.5-10
• /
• 2005

This paper presents the new in-flight alignment method using the flight distance of vehicle in order to improve the performance of the heading error estimation. In the proposed method, the Kalman filter having the difference between GPS and SDINS position as measurements is used for levelling of SDINS and heading error is estimated utilizing the flight distance information. It is shown in the simulation results that the in-flight method proposed in this paper has the high accuracy in heading error estimation and the heading error can be very quickly estimated at the high speed vehicle, compared with the existing method using the Kalman filter.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.05a
• /
• pp.501-503
• /
• 2013

This project presents a concept of mobile robots using prototypes, computing proposal oriented to embedded systems implementation. We implement our system using GPS module, Ultrasonic sensor(range sensors), H-bridge dual stepper control, DTMF(Dual-tone Multi-Frequency ) and LCD module. In this paper we construct a mechanical simple mobile robot model, which can measure the distance from obstacle with the aid of sensor and should able to control the speed of motor accordingly. Modules were interfaced with FPGA(Field Programmable Gate Array) controller for hardware implementation.

• Nuclear Engineering and Technology
• /
• v.54 no.4
• /
• pp.1355-1362
• /
• 2022

Nuclear fuel, including its fresh state, must be handled safely due to its critical and hazardous nature. Under normal transport conditions, several interactions take place among different components, such as transport cask used for loading the nuclear fuel and tie-down structure to attach with the vehicle. To ensure structural integrity of the nuclear fuel, vibrations and impacts transmitted from the vehicle must be sufficiently reduced. Therefore, in this study, we conducted two transportation tests from Daejeon to Kijang in Korea to verify the vehicle-induced vibrational characteristics of the KJRR-F fresh nuclear fuel when transported under normal transport conditions. The speed and location of the vehicle were obtained via GPS, and the accelerations between the vehicle and the KJRR-F fresh nuclear fuel were measured. Additionally, using the acceleration results, a structural analysis was conducted to confirm the structural integrity of the nuclear fuel under the most severe conditions during normal transport.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.11
• /
• pp.2697-2702
• /
• 2015

In the existing studies providing a method which do exercise according to music speed, the method was used which a user changes playing musics. However, if the method which a user changes directly playing musics is used, flow of exercise can be discontinued during searching musics when anyone want to play a fast music. In this paper, we designed the module which measures the number of steps from a user of wearable smart shoes based on the Arduino, and implemented the module so that the number of steps can be measured correctly by sending data to smart phone based on Android. And it is possible to measure moving distance and pace speed by utilizing a GPS in order to get the more accurate momentum. Also, we can measure more accurate calorie consumption than existing products by measuring the mean value of the calorie consumption for moving distance and the calorie consumption for the number of steps, give motivation of exercise by applying an algorithm of changing music genre according to pace speed, and increase the exercise effect at the same time.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.1
• /
• pp.54-60
• /
• 2013

This paper presents a ground altitude determination algorithm using a laser altimeter and GPS for automatic take-off and landing of UAV. The characteristics of the laser altimeter was analyzed in ground tests and a low-pass filter was designed to reduce the effect of signal interruption due to reflectivity problem. The paper shows that a single sensor cannot measure ground altitude appropriately in terms of reliability and accuracy. To complement shortcomings of the laser altimeter, the linear Kalman filter was designed using DGPS vertical speed. Designed filter was validated and tuned through the steps of simulation, ground test and flight test. It was confirmed that the accuracy for automatic landing is achievable.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.11
• /
• pp.1549-1556
• /
• 2016

By increased moving speed of aircraft, estimating location of itself becomes more important than ever. This requirement is satisfied by appearance of GPS, however it is useless when signal reception from satellite is not good enough by interruption, for example, traffic jamming. Applying link for communication to additional positioning system is capable of providing relative position of aircraft. Estimating location with link for communication is done without additional equipment but with signal processing based on correlation of received signal. ESPRIT is one of the representative algorithm among them. Estimating correlation matrix is possible to have error since it includes average operation needs enough number of samples not impractical. Therefore we propose algorithm that defines, estimates and removes error matrix of correlation. Proposing algorithm shows better performance than previous one when transmitters are close.

• KIISE Transactions on Computing Practices
• /
• v.24 no.2
• /
• pp.59-66
• /
• 2018

In this paper, we propose a system to detect various damage automatically inflicted on road pavement by collecting and analyzing data from acceleration and camera sensors in real time. The proposed system sends the collected images, acceleration signals, and GPS coordinates to the road manager and the database in the remote server, shortly after detecting the damage to the road pavement. Our study makes three key contributions. The proposed system 1) enables road managers to maintain road conditions quickly, accurately, and conveniently; 2) allows road mangers to take care of various kinds of damage to the road pavement at the initial stage; and finally 3) even makes it possible to track the damage, which suggests that the integration of a high-level decision support function becomes affordable. We tested the sensitivity and precision of the proposed system against real-time data obtained from the vehicles driving on the highway at an average speed of 100 km/h. With ten iterations, the proposed system achieved an average sensitivity of 74% and an average precision of 84% in road pavement damage detection, which is comparable with the best competing schemes.

• Journal of Korea Spatial Information System Society
• /
• v.5 no.1 s.9
• /
• pp.65-74
• /
• 2003

Location-based service is an important spatiotemporal database application area that provides the location-aware information of wireless terminals via positioning devices such as GPS. With the rapid advances of wireless communication systems, the requirement of mobile application areas including traffic, mobile commerce and supply chaining management became the center of attention for various research issues in spatiotemporal databases. In this paper we present the A-Quadtree, an efficient indexing method for answering location-based queries where the movement vector information (e.g., speed and velocity) is not presented. We implement the A-Quadtree with an index structure for object identifiers as a.Net component to apply the component to multiplatforms. We present our approach and describe the performance evaluation through various experiments. In our experiments, we compare the performance with previous approaches and show the enhanced efficiency of our method.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.1
• /
• pp.18-24
• /
• 2015

Train positioning detection information is fundamental for high-speed railroad inspection, making it possible to simultaneously determine the status and evaluate the integrity of railroad equipment. This paper presents the results of measurements and an analysis of an inertial measurement unit (IMU) used as a positioning detection sensors. Acceleration and angular rate measurements from the IMU were analyzed in the amplitude and frequency domains, with a discussion on vibration and train motions. Using these results and GPS information, the positioning detection of a Korean tilting train express was performed from Naju station to Illo station on the Honam-line. The results of a synchronized analysis of sensor measurements and train motion can help in the design of a train location detection system and improve the positioning detection performance.