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The existence of non-line-of-sight (NLOS) errors will considerably degrade the localization accuracy. Therefore, the NLOS node localization is investigated. In this article, we propose a NLOS node localization algorithm that utilizes the firefly algorithm. The objective function is established by the probability of propagation of NLOS and LOS according to the approximate maximum likelihood method...
The non-iterative algorithm that reveals the general physical basis of measuring processes and instrumental (computer) computations is proposed and investigated. The algorithm is based on the previously proposed postulate and consists in finding the optimal, locally defined width of the averaging interval. The optimal width of the interval provides the smallest error when measuring or computing the...
A self calibration technique for a multiport vector network analyzer (VNA), based on the full error model, is presented. Hence, a characterization of the measurement instrument with the help of partially unknown calibration standards is possible. As a consequence, the dependency on absolute defined calibration standards is reduced. Therefore, the accuracy of the measurements increases and the fabrication...
The accuracy and productivity of measurement performed with the help of coordinate measuring machines depend not only on their technical characteristics but also on the strategy used to select the number, location of the points and the sequence of their circumvention on the surface. The article proposes a new strategy for the determination of the number and location of control points on surfaces based...
A system for evaluating instrument current transformer errors using a lock-in amplifier is described in the paper. The difference between the standard and the transformer under test is evaluated as the ratio error and the phase displacement. The attention is focused to measurement of errors at the range of primary currents less than 20% of the nominal value. The measurement accuracy of current and...
Participation of electromagnetic compatibility testing laboratories in proficiency tests is a recommended practice for the purpose of assuring the quality of test results. Participation to proficiency tests is mandatory for laboratories accredited to ISO/IEC 17025 [1]. However a proficiency test can be successfully organized and completed only if the measurement method in the scope of the proficiency...
The antenna tilting has not been specifically mentioned in the EMC product standards which include radiated emission test. However, CISPR 16-4-2 standard, which is the reference for the measurement uncertainty calculations of the radiated emission test in these standards, shows that directivity difference parameter changes according to using antenna tilt feature. The reproducibility of the tests gets...
Almost independent of the program, technology or functionality, the number one issue facing everyone is tackling the ever-increasing desire for tighter design margin. This has not only pushed designers and their simulation tools to the edge, it has kept test and test strategies one step behind the growing measurement needs. The result has been lower yields, greater false failures and a swelling number...
This work is devoted to determination of the relationship between two different approaches for wireless link quality assessment: 1) using continuous error rate parameter of bits flow — bit error rate (BER), and 2) quality parameters defined in the ITU-T G.826 standard (12/2002) for digital paths — errored block (EB), errored second (ES), severely errored second (SES), and respective Ratio parameters...
Power line communication characterization need complete knowledge of the network such as topology, cable parameters, connected loads, and so on. In practice, home power grids topology is not entirely acknowledged. In common cases, the blueprint showing the interconnection between power outlets is unavailable. If it exists, the lengths of the different sections are not mentioned. This work proposes...
The reproducibility of the Absorber Lined Shielded Enclosure (ALSE) radiated emission test method, defined in the standard CISPR 25, is evaluated through an interlaboratory comparison (ILC). The ILC started on September 2016 and concluded on February 2017. Nineteen data sets have been received. The investigated frequency range is from 1 MHz to 1000 MHz. The most critical (worst reproducibility) frequency...
• It has been shown that measured SVSWR is smaller than peak SVSWR. The measured SVSWR covers approximately 75% of the SVSWR • An method is shown to use a moving window to estimate the real SVSWR level. The site contribution to emissions measurement MIU can be derived based on the full knowledge of the SVSWR. • SVSWR of the back half of the QZ is not currently considered by the standard, but the levels...
According to the problem of high cost of standard apparatuses and complex operating for the traditional AC current measurement, this paper introduces a method to measure the AC current with high performance which is based on using digitizing system and the AC-DC difference calculable resistance. Compared verification tests indicate a maximum deviation of 2.3 × 10−5 between the digital sampling measurement...
Guidance on accounting for site imperfections in the uncertainty evaluation of emissions measurement result is provided by CISPR 16-4-2. Site Voltage Standing Wave Ratio (SVSWR) results from the chamber are used as the basis for estimating the uncertainty contributions due to the site. In this paper, we investigate two aspects of the uncertainty evaluation, and provide a method to estimate the uncertainties...
Based on measurement of AC impedance, this paper presents a new method for evaluating measurement uncertainty of AC impedance. The method of equal potential measurement is introduced, which can calibrate AC impedance and trace to voltage ratio standard and phase standard by adjusting the current in the circuit. What's more, the measurement data of 1 kHz, 100 Ω is given in the paper, whose measurement...
We exploit how to overcome phase damping decoherence when the phase damping parameters are uncertain. It is shown that the “relaxed” control goal may be achieved by combing simple open-loop coherent control with periodic projective measurements. Both the sufficient conditions and constructive design procedures are presented. The control design is reduced to selecting the period of projective measurements...
Because the inconsistencies always could be found in the comparison, Cox recommended Monte Carlo Method (MCM) to solve this problem and determine the key comparison reference value (KCRV). In the paper, we introduced the MCM in analyzing APMP.M.M-K1 international measurement comparisons. This method, which is based on statistics estimation method, can directly give the degrees of equivalence(DoE)...
The recent growing interest for indoor Location-Based Services (LBSs) has created a need for more accurate and low-cost indoor localization system. The existing solutions are either low-cost with low-accuracy or high-accuracy with high-cost. A positioning solution for indoor localization system with Bluetooth and UWB is proposed in this paper. The system combines both advantages of Bluetooth and UWB,...
Stemming is a technique that transforms morphologically similar terms into a unique term without doing a complete morphological analysis. Stemming is used as a preprocessing step in many Natural Language Processing (NLP) applications like Information retrieval (IR), Machine Translation, Parsing, Summarization, etc. The present work explores the application of stemming to the task of information retrieval...
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