scholarly journals Frequency-Locked Detector Threshold Setting Criteria Based on Mean-Time-To-Lose-Lock (MTLL) for GPS Receivers

Sensors ◽  
2017 ◽  
Vol 17 (12) ◽  
pp. 2808 ◽  
Author(s):  
Tian Jin ◽  
Heliang Yuan ◽  
Na Zhao ◽  
Honglei Qin ◽  
Kewen Sun ◽  
...  
Keyword(s):  
Gps Receivers ◽  
Threshold Setting ◽  
Mean Time ◽  
Detector Threshold

Reliability Performance in GPS Receivers and the Nature of Their Failures: Planning to Live with Realistic Failure Rates in Satellite Navigation System Receivers

1997 ◽  
Vol 50 (2) ◽  
pp. 172-182
Author(s):  
Sarah Sharkey ◽  
Rolf Johannessen
Keyword(s):  
Navigation System ◽  
Gps Receiver ◽  
Gps Receivers ◽  
Satellite Navigation System ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Reliability Performance ◽  
Mean Time ◽  
Operational Implication ◽  
Require Data

This paper and the following three papers were presented at the Institute's NAV-96 Conference, “Global Navigation — Where are we now?” The Conference was held in London In November 1996. Copies of the full proceedings may be obtained on application to the Director, price £35 for members and £50 for non-members.The National Air Traffic Services (NATS) in London require data on the performance likely to be achieved by the navigation system on board aircraft flying in UK airspace. To that end the performance of three different GPS receiver types (all designed for aviation use) have been examined. This paper details the result of that work. The achieved Mean Time Between Failures (referred to here as ‘Outages’) MTBO is presented along with the nature of some of the failures that have been encountered. The paper concludes with the operational implication of the findings.

Predicting Daily Maintenance Dose of Fluindione, an Oral Anticoagulant Drug

1996 ◽  
Vol 75 (05) ◽  
pp. 731-733 ◽  
Author(s):  
V Cazaux ◽  
B Gauthier ◽  
A Elias ◽  
D Lefebvre ◽  
J Tredez ◽  
...  
Keyword(s):  
Effective Dose ◽  
Maintenance Dose ◽  
Successive Approximations ◽  
Hemorrhagic Complication ◽  
Simple Method ◽  
Individual Variations ◽  
Anticoagulant Drug ◽  
The Mean ◽  
Mean Time ◽  
Daily Maintenance Dose

SummaryDue to large inter-individual variations, the dose of vitamin K antagonist required to target the desired hypocoagulability is hardly predictible for a given patient, and the time needed to reach therapeutic equilibrium may be excessively long. This work reports on a simple method for predicting the daily maintenance dose of fluindione after the third intake. In a first step, 37 patients were delivered 20 mg of fluindione once a day, at 6 p.m. for 3 consecutive days. On the morning of the 4th day an INR was performed. During the following days the dose was adjusted to target an INR between 2 and 3. There was a good correlation (r = 0.83, p<0.001) between the INR performed on the morning of day 4 and the daily maintenance dose determined later by successive approximations. This allowed us to write a decisional algorithm to predict the effective maintenance dose of fluindione from the INR performed on day 4. The usefulness and the safety of this approach was tested in a second prospective study on 46 patients receiving fluindione according to the same initial scheme. The predicted dose was compared to the effective dose soon after having reached the equilibrium, then 30 and 90 days after. To within 5 mg (one quarter of a tablet), the predicted dose was the effective dose in 98%, 86% and 81% of the patients at the 3 times respectively. The mean time needed to reach the therapeutic equilibrium was reduced from 13 days in the first study to 6 days in the second study. No hemorrhagic complication occurred. Thus the strategy formerly developed to predict the daily maintenance dose of warfarin from the prothrombin time ratio or the thrombotest performed 3 days after starting the treatment may also be applied to fluindione and the INR measurement.

Clinical and Radiological Changes after use of Alpha-1 Blocker Therapy in Patients of Posterior Urethral Valve with Bladder Neck Hypertrophy

JMS SKIMS ◽  
2009 ◽  
Vol 12 (1) ◽  
pp. 3-7
Author(s):  
Aejaz A Baba ◽  
Bajpai Minu
Keyword(s):  
Bladder Neck ◽  
Posterior Urethral Valve ◽  
Posterior Urethral Valves ◽  
Blocker Therapy ◽  
Urethral Valve ◽  
Novel Method ◽  
Radiological Changes ◽  
Group 2 ◽  
Mean Time ◽  
Group 1

Background: We evaluated the effects of alpha-1 blocker therapy on clinical and radiological abnormalities in patients of posterior urethral valve with bladder neck hypertrophy. Materials and Methods: A total of 74 patients with posterior urethral valves were seen at our department between 2003 and 2007. Out of these 24 had radiological evidence of bladder neck hypertrophy. Those patients with bladder neck hypertrophy who were seen before June 2006 and did not receive alpha-1 blocker (prazocin) therapy after valve ablation were assigned to group 1 (n=10). Group 2 consisted of 14 age matched patients with bladder neck hypertrophy and comparable prognostic factors who received alpha-1 blocker therapy after valve ablation (n=14). Micturating cystourethrography (MCU) was done periodically and a novel method used to calculate bladder neck hypertrophy. Trends in symptoms and radiological changes were evaluated throughout follow-up. Results: Mean patient age at presentation was 3.02±2.68 years in group 1 and 3.12±3.4 years in group 2. Bladder neck hypertrophy decreased from 2.3±1.0 to 2.0±0.5 in a mean time of 52.0 (34-52) weeks in group 1 where as it decreased from 2.2±0.5 to 1.6±0.3 in a mean time of 32.0 (22-52) weeks. Symptomatically patients in group 2 who received alpha-1 blocker therapy after valve ablation were better and had quick resolution of bladder neck hypertrophy. Conclusions: Use of alpha-1 blocker therapy in patients of posterior urethral valve with bladder neck hypertrophy helps in quick resolution of bladder neck hypertrophy. J Med Sci 2009;12(1):3-7.

Experimental Application of Global Positioning system To Locate Motor Vehicle Crashes: Impact on Time and Accuracy

1998 ◽  
Vol 1625 (1) ◽  
pp. 41-49 ◽  
Author(s):  
John S. Miller ◽  
Duane Karr
Keyword(s):  
Global Positioning System ◽  
Human Error ◽  
Motor Vehicle ◽  
Motor Vehicle Crash ◽  
Positioning System ◽  
Gps Receivers ◽  
Crash Data ◽  
Vehicle Crash ◽  
Global Positioning ◽  
Conventional Methods

Motor vehicle crash countermeasures often are selected after an extensive data analysis of the crash history of a roadway segment. The value of this analysis depends on the accuracy or precision with which the crash itself is located. yet this crash location only is as accurate as the estimate of the police officer. Global Positioning System (GPS) technology may have the potential to increase data accuracy and decrease the time spent to record crash locations. Over 10 months, 32 motor vehicle crash locations were determined by using both conventional methods and hand-held GPS receivers, and the timeliness and precision of the methods were compared. Local crash data analysts were asked how the improved precision affected their consideration of potential crash countermeasures with regard to five crashes selected from the sample. On average, measuring a crash location by using GPS receivers added up to 10 extra minutes, depending on the definition of the crash location, the technology employed, and how that technology was applied. The average difference between conventional methods of measuring the crash location and either GPS or a wheel ranged from 5 m (16 ft) to 39 m (130 ft), depending on how one defined the crash location. Although there are instances in which improved precision will affect the evaluation of crash countermeasures, survey respondents and the literature suggest that problems with conventional crash location methods often arise from human error, not a lack of precision inherent in the technology employed.

Measured Effects of a Narrowband Interference Suppressor on GPS Receivers

1999 ◽  
Author(s):  
P. T. Capozza ◽  
B. J. Holland ◽  
T. M. Hopkinson ◽  
C. Li ◽  
D. Moulin ◽  
...  
Keyword(s):  
Narrowband Interference ◽  
Gps Receivers

Reliability Analysis of Cold Standby Parallel System Possessing Failure And Repair Rate Under Geometric Distribution

2019 ◽  
Vol 13 ◽  
Author(s):  
Jasdev Bhatti ◽  
Mohit Kumar Kakkar
Keyword(s):  
Failure Rate ◽  
Geometric Distribution ◽  
Discrete Distribution ◽  
Maintenance Cost ◽  
Discrete Problem ◽  
New Techniques ◽  
Testing Strategies ◽  
Cold Standby ◽  
Mean Time ◽  
Iteration Technique

Background and Aim: With an increase in demands about reliability of industrial machines following continuous or discrete distribution, the important thing to be noticed is that in all previous researches where systems are having more than one failure no iteration technique has been studied to separate the failed unit on basis of its failure. Therefore, aim of our paper is to analyze the real industrial discrete problem following cold standby units arranged in parallel manner with newly concept of inspection procedure for failed units to inspect the exact failure and being communicator to the repairman for repairing exact failed part of unit for saving time and maintenance cost. Methods: The geometric distribution and regenerative techniques had been applied for calculating different reliability measures like mean time to system failure, availability of a system, inspection, repair and failed time of unit. Results: Graphical and analytical study had also been done to analyze the increasing/decreasing behavior of profit function w.r.t repair and failure rate. The system responded properly in fulfilling his basic needs. Conclusion: The calculated value of all reliability parameter is helpful for studying any other models following same concept under different environmental conditions. Thus, it concluded that, reliability increases/decreases with increase in repair/failure rate. Also, the evaluated results by this paper provides the better reliability testing strategies that helps to develop new techniques which leads to increase the effectiveness of system.

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