A complete impulse-based ultrawideband localization demonstrator for indoor applications is presented. The positioning method, along with the method of positioning error predicting, based on scenario geometry, is described. The hardware setup, including UWB transceiver and time measurement module, as well as the working principles is explained. The system simulation, used as a benchmark for the quality assessment of the performed measurements, is presented. Finally, the measurement results are discussed. The precise analysis of potential error sources in the system is conducted, based on both simulations and measurement. Furthermore, the methods, how to improve the average accuracy of 9 cm by including the influences of antennas and signal-detection threshold level, are made. The localization accuracy, resulting from those corrections, is 2.5 cm.
This paper discusses the operating range of frequency modulated (FM) radars in the presence of interference. For this purpose, radar- and path loss equations are used to draw the equipotential lines for a given signal-to-interference ratio as a function of the spatial distribution of targets and interferers in order to identify relevant scenario constellations. Further the factors influencing the gain of signal versus deterministic interference are discussed based on measurements and simulations. Finally, the influence of different kinds of interference on the spectrum of a frequency modulated continuous wave radar is shown.
Autoimmunity may be involved in idiopathic premature ovarian failure (POF). However, the frequency, physiopathology and potential reversibility of autoimmune oophoritis needs clarification. Using an ELISA against whole tissue homogenate as antigen, from human ovaries at different ages, positive circulating ovarian antibodies (AOA) were found in 59% of patients with primitive idiopathic POF (27/46); 20/27 were positive for IgG isotype, 9/27 for IgM and 8/27 for IgA. Specificity of AOA was examined (i) by comparison to different control groups; mean values of the three subclasses of immunoglobins were significantly higher in POF women than in normally cycling fertile young women (n = 23) and fertile young men (n = 17), in untreated Grave's disease (n = 35) or in women with positive antinuclear factor (n = 25); and (ii) by assessing possible cross-reaction; only six out of the 27 positive sera reacted with other tissues (thyroid, pancreas, adrenal), including four clinical polyendocrinopathies. Significance of AOA was explored (i) by comparison with postmenopausal women (n = 40) and older women (n = 15), who did not have enhanced ratios of AOA, thereby excluding a potential role of high FSH values; (ii) by analysing the factors time and surgery; no relation could be found either with the duration of amenorrhoea (6 months to 21 years) or with the history of an ovarian biopsy (12/47) in the absence of any associated pelvic surgery; and (iii) by screening for other immunological factors; familial or personal autoimmune disease (8/46), HLA DR3 (10/42), HLA DR4 (11/42), associated autoantibodies (thyroperoxidase, adrenal, beta islets, parathyroid, DNA, smooth muscles) (12/42). If one positive AOA isotype was present, a second immunological factor was found in 45% of cases. Spontaneous pregnancies during oestrogen therapy occurred in four cases, including three women with positive AOA. Circulating AOA detected by an ELISA may represent a practical and suitable marker for diagnosis of POF. Its use for prognosis and rational treatment needs further evaluation.
This paper provides qualitative and quantitative values for the received interference power at the antenna ports of automotive radars as well as the probability of their occurrence for actual and future, not yet measurable traffic scenarios on main roads. The influence of the environment, the road traffic behavior, and the radar penetration rate for a defined antenna configuration can be observed. The basis for the analyses are ray-tracing based simulations in order to achieve adequate predictions for the received power levels due to multipaths. The results show that for a radar penetration rate of 100%, the difference between the strongest overall incoherent received interference power level and the level that is received in 90% of the time is up to 7 dB, dependent on the antenna placement and the environment.
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