• ETRI Journal
• /
• v.38 no.3
• /
• pp.579-588
• /
• 2016

To improve the ability to determine a vehicle's movement information even in a challenging environment, a hybrid approach called non-Gaussian square rootunscented particle filtering (nGSR-UPF) is presented. This approach combines a square root-unscented Kalman filter (SR-UKF) and a particle filter (PF) to determinate the vehicle state where measurement noises are taken as a finite Gaussian kernel mixture and are approximated using a sparse Gaussian kernel density estimation method. During an outage-free GPS period, the updated mean and covariance, computed using SR-UKF, are estimated based on a GPS observation update. During a complete GPS outage, nGSR-UPF operates in prediction mode. Indeed, because the inertial sensors used suffer from a large drift in this case, SR-UKF-based importance density is then responsible for shifting the weighted particles toward the high-likelihood regions to improve the accuracy of the vehicle state. The proposed method is compared with some existing estimation methods and the experiment results prove that nGSR-UPF is the most accurate during both outage-free and complete-outage GPS periods.

• Journal of Navigation and Port Research
• /
• v.33 no.9
• /
• pp.603-608
• /
• 2009

In this paper, a 3m-class free running model ship will be introduced with its manoeuvring performance experiments. The results of turning circle test and zig-zag test will be explained. The developed system are equipped with GPS, main control computer, wireless LAN, IMU (Inertial Measurement Unit), self-propulsion propeller and driving rudder. Its motion can be controlled by RC (Radio Control) and wireless LAN from land based center. Automatic navigation is also available by pre-programmed algorithm. The trajectory of navigation can be acquired by GPS and it provides us with important data for ship's motion control experiments. The results of manoeuvring performance experiment have shown that the developed free running model ship can be used to verify the test of turning circle and zig-zag. For next step, other experimental researches such as ship collision avoidance system and automatic berthing can be considered in the future.

• Journal of information and communication convergence engineering
• /
• v.6 no.1
• /
• pp.6-9
• /
• 2008

In future domestic context aware applications the location of mobile devices is often required. Ultrasonic technology enables high resolution indoor position measurements. A disadvantage of state-of-art ultrasonic systems is that several base stations are required to estimate 3D position. This study aims to evaluate the efficiency and effectiveness of using UPS as a 3D free-hand writing or drawing tool. The processes include the design and testing of UPS as an efficient 3D free-hand writing or drawing tool in the air. The paper will further explain the system architecture of the UPS and how to use GPS as 3D free-hand writing or drawing tool. The efficiency and effectiveness of the system was confirmed by a computer software simulation. The software will further display the result of drawing or writing from the user by graphics. As a result, it is possible to implement UPS as a 3D free-hand writing or drawing tool in the air.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.10
• /
• pp.4677-4680
• /
• 2016

Background: The Glasgow Prognostic Score (GPS) is calculated from measured CRP and albumin levels. We here evaluated the significance of the GPS in patients with resected pulmonary adenocarcinoma. Materials and Methods: The present study included 156 patients with lung adenocarcinoma who underwent lobectomy at Kanazawa Medical University between 2002 and 2012. Classification was into three groups: those with normal albumin (>=3.5 g/dl) and C-reactive protein (CRP) (<=1.0 mg/dl) levels were classified as GPS 0 (n =136), those with low albumin (<3.5 g/dl) or elevated CRP (>1.0 mg/dl) levels as GPS 1 (n = 16), and those with low albumin (<3.5 g/dl) and elevated CRP (>1.0 mg/dl) levels as GPS 2 (n = 4). We retrospectively investigated relationships between the patient characteristics including the GPS, and disease-free survival and cancer-specific survival. Results: The pathological stages of the patients were as follows: IA (n=78, 50%), IB (n=31, 19.9%), IIA (n=20.0, 12.8%), IIB (n=9.0, 5.7%), and IIIA (n=18.0, 11.5%). Lobectomy was performed in all cases. The average GPS was 0.15 (0-2) and showed significant relationships with stage and tumor size. The 2-year survival rates in patients with GPS0, 1 and 2 were 81.4%, 38.4%, and 25.0%, respectively. Clear correlations were noted with both cancer-specific survival and disease-free survival. Furthermore, multivariate analysis revealed that GPS was a significant prognostic factor. Conclusions: The GPS could be a prognostic factor for patients with resected pulmonary adenocarcinoma.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2003.04a
• /
• pp.425-428
• /
• 2003

Real time monitoring of object position is very important in Customs Free Zone like Incheon Airport and Incheon Harbor because all logistics must be controled spatially for effective management. Real time positioning system using GPS(Global Positioning System) is apt for the monitoring of logistics. In this study, we aims to develope real time monitoring system for logistics using GPS.

• Journal of Astronomy and Space Sciences
• /
• v.14 no.2
• /
• pp.347-354
• /
• 1997

We developed a GPS phase data processing S/W system which calculates baseline vectors and distances between two points located in the surface of the Earth. For this development a Double-Difference mothod and L1 carrier phase data from GPS(Global positioning System) were used. This S/W system consists of four main parts: satellite position calculation, Single-Difference equation, Double-Difference equation, and correlation. To verify our S/W, we fixed KAO($N36^{circ}.37,E127^{circ}.37,H77.61m$), one of the International GPS Services for Geodynamics, which is located at Tae-Jon, and we measured baseline vectors and relative distances with data from observations at approximate baseline distances of 2.7, 42.1, 81.1, 146.6km. Then we compared the vectors and distances with the data which we obtained from the GPSurvey S/W system, with the L1/L2 ION-Free method and broadcast ephemeris. From the comparison of the vectors and distances with the data from the GPSurvey S/W system, we found baseline vectors X, Y, Z and baseline distances matched well within the extent of 50cm and 10cm, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.451-454
• /
• 2006

Ultrasonic Positioning System (UPS) is an absolute positioning system using ultrasonic waves and has better performance in low price than the other absolute positioning systems. UPS can be further used as pseudo-satellites in the place where GPS is not available. This study aims to evaluate the efficiency and effectiveness of using UPS as a 3D free-hand writing or drawing tool. The process includes the design and testing of VPS as an efficient 3D free-hand writing or drawing tool in the air. The paper will further explain the system architecture of the UPS and how to use GPS as 3D free-hand writing or drawing tool. The efficiency and effectiveness of the system was confirmed by a computer software simulation. The software will further display the result of drawing or writing from the user by graphics. As a result, it is possible to implement UPS as a 3D free-hand writing or drawing tool in the air.

• Journal of Advanced Navigation Technology
• /
• v.15 no.4
• /
• pp.502-509
• /
• 2011

It is necessary to resolve integer ambiguity in GPS carrier based precise positioning. If there is no signal blockage or cycle slip, the integer ambiguity does not changed. however, signal blockage and cycle slip occur frequently under real operational environment. under this situation, integer ambiguity maintenance is indispensable for continuity of navigation information. In this paper, a cycle slip free technique is proposed for simplifying integer ambiguity maintenance procedure. this technique tested with simulated carrier phase signal with cycle slip aided intentionally. As a result, the proposed technique can give navigation information continuously even if cycle slip is occured.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.288-288
• /
• 2006

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.2
• /
• pp.211-217
• /
• 2014

This paper addresses an algorithm of path planning for autonomous driving of a ground vehicle in waypoint navigation. The proposed algorithm is flexible in utilization under a large GPS positioning error and generates collision-free multiple paths while pursuing minimum traveling time. An optimal path reduces inefficient steering by minimizing lateral changes in generated waypoints along a path. Simulation results compare the proposed algorithm with the A* algorithm by manipulation of the steering wheel and traveling time, and show that the proposed algorithm realizes real-time obstacle avoidance by quick processing of path generation, and minimum time traveling by producing paths with small lateral changes while overcoming the very irregular positioning error from the GPS.