Most Differential Global Positioning System (DGPS) correction formats are based on range information, and thus typical DGPS systems can be implemented only on correction message-readable or raw observable-providing devices. There is no other way to improve an already-calculated position than a 'block shift technique', which has a very limited applicability. This paper suggests an algorithm to project measurement correction directly to position domain data without requiring raw pseudorange data. By post-processing methodology, we evaluated the performance of our new algorithm compared to conventional DGPS, which requires raw pseudorange data; the observed difference between them was only 0·1 mm . The proposed correction projection algorithm can be used with commercial off-theshelf receivers that provide National Marine Electronics Association (NMEA) format data. Our testing with a U-blox LEA-5H receiver resulted in a drastic reduction of horizontal Root Mean Square (RMS) error from 4·75 m to 1·09 m. K E Y
This paper presents a means of carrier phase cycle slip detection for an inertial-aided global positioning system (GPS), which is based on consideration of the satellite geometry. An integrated navigation solution incorporating a tightly coupled time differenced carrier phase (TDCP) and inertial navigation system (INS) is used to detect cycle slips. Cycle-slips are detected by comparing the satellite-difference (SD) and time-difference (TD) carrier phase measurements obtained from the GPS satellites with the range estimated by the integrated navigation solution. Additionally the satellite geometry information effectively improves the range estimation performance without a hardware upgrade. And the covariance obtained from the TDCP/INS filter is used to compute the threshold for determining cycle slip occurrence. A simulation and the results of a vehicle-based experiment verify the cycle slip detection performance of the proposed algorithm.
Purpose:The purpose of this mixed method study was to examine effects of the self-transcendence enhancement program among patients with drug addiction, and to explore their experiences through the program. Methods: For the quantitative study, a non-equivalent control group quasi-experimental design was used. The sample was 49 hospitalized patients with drug addiction. The self-transcendence enhancement program was provided twice a week for 6 weeks. Quantitative data were analyzed using x 2 test, t-test and ANCOVA. For the qualitative study, 12 patients in the experimental group participated in a focus group interview, and data were analyzed using the content analysis technique. Results: After the intervention, there were significant improvements for the experimental group in self-transcendence and declines in depression compared to the control group. From the qualitative findings three themes were identified as the change process after the intervention: 'looking back at myself', 'gaining confidence through small changes', and 'finding meaning in life'. Conclusion: Results suggest that the self-transcendence enhancement program can be utilized as a nursing intervention program for patients with drug addiction.
Cycle-slip detection is mandatory prior to estimating positions based on carrier-phase observations. Recently, inertial sensors are integrated to detect cycle-slips regardless of sizes and combinations of cycle-slips in different frequencies. However, since inertial sensors contain errors such as random noise and bias, performance of the cycle-slip detection depends on the sensor performance. In general, there is a trade-off relationship between cost and performance of sensors, and we need to select appropriate sensors to achieve required cycle-slip detection performance. Therefore, we need a standard to select appropriate sensors. This paper introduces a procedure to predict allowable sensor error limit for gyroscope and odometer aided cycle-slip detection using theoretical formulation. By using error models of sensors, an error equation is set to predict error contributions from the sensors contained in the monitoring value that is used for cycle-slip detection. Simulation data is used to evaluate derived error equation and predict the error limit of sensors achieving objective performance. As a result, allowable sensor error region is predicted to detect 1 cycle-slip as a minimum detectable cycle-slip. This approach can be extended to accelerometers, and then it can be applied not only to vehicles on land, but also to those in aerospace.
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