Developing a Methodology to Detect Partial Failures for Dynamic Systems

The purpose of this research is to develop a decision support system that can assist in detecting partial failures in dynamic systems such as Fire Control System Tracking Radar (TR) onboard Naval Ships. Partial failures do not necessarily shut down the system immediately but cause degradation of operational performance. Previous work has shown that experts in the field of failure detection, test point insertion and Built-In-Test Equipment (BITE) can provide useful input in detecting partial failures. Partial failures affect operational system performance and support costs, which can be significant. Often, however, partial failure detection consists of the estimations and opinions of the experts. This has not been addressed adequately in the literature. It is postulated that the approach developed in this research could be applied to maintain and monitor partial failure. The development of such a testing aid is the thrust of this research effort. Markov chains, k-out-of-n: G: system and critical path tracing techniques, among others are employed. Appropriate survey questionnaires are used for validation of the resulting test model. Application of previous test point insertion techniques are applied as a part of system comparison and assessment

Monitoring of virgin coconut oil (VCO) adulteration with palm oil using fourier transform infrared spectroscopy.

Virgin coconut oil (VCO) may be adulterated with cheaper oils, such as palm oil (PO). Thus, the detection and quantification of VCO adulteration with PO was monitored using Fourier transform infrared (FTIR) spectroscopy, combined with chemometrics of partial least square (PLS) and discriminant analysis at frequency regions of 3,010–3,000, 1,660–1,650 and 1,120–1,105/cm. Attenuated total reflectance (ATR) measurements were made on pure VCO and that adulterated with varying concentrations of PO (0.5–50% w/w in VCO). PLS calibration exhibited a good relationship between actual and FTIR-predicted values with coefficient of determination (R2) of 0.999 and standard error of calibration of 0.533. The cross validation was performed by removing one standard at a time, and the final R2 value of 0.996 and standard error of prediction of 0.953 were obtained. The discriminant analysis using seven principal components was able to classify pure VCO and that adulterated with PO

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The signal classification performance of four types of Electronics Support Measure (ESM) Communications detection systems is compared from the standpoint of the unintended receiver (interceptor). Typical digital communication signals considered include Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), Frequency Shift Keying (FSK), and On-Off Keying (00K). The analysis emphasizes the use of available signal processing software. Detection methods compared include broadband energy detection, FFT- based narrowband energy detection, and two correlation methods which employ the Fast Fourier Transform (FFT). The correlation methods utilize modified time- frequency distributions, where one of these is based on the Wigner-Ville Distribution (WVD). Gaussian white noise is added to the signal to simulate various signal-to-noise ratios (SNRs)http://archive.org/details/analysisofdigita1094530528NANABahrain Navy author

Wind power analysis and site matching of wind turbine generators in Kingdom of Bahrain

In this paper, the hourly measured wind speed data for years 2003-2005 at 10 m, 30 m and 60 m height for Kingdom of Bahrain have been statically analyzed to determine the potential of wind power generation. Extrapolation of the 10 m data, using the Power Law, has been used to determine the wind data at heights of 30 m and 60 m. Weibull distribution parameters have been estimated and compared annually and on monthly bases using two methods; the graphical method and the another method, designated in this paper as approximated method, which depends on the standard deviation and average wind speed. The maximum power density for 10 m, 30 m and 60 m heights were found to be 164.33 W/m2, 624.17 W/m2 and 1171.18 W/m2 in February, respectively while the minimum power density were 65.33 W/m2, 244.33 W/m2 and 454.53 W/m2 in October, respectively. The average annual wind power density was found to be 114.54 W/m2 for 10 m height, 433.29 W/m2 for 30 m height and 816.70 W/m2 for 60 m height. Weibull probability function, using Weibull parameters estimated from the approximated method, has shown to provide more accurate prediction of average wind speed and average power density than the graphical method. In addition, the site matching of wind turbine generators at 30 m and 60 m heights has been investigated by estimating the capacity factors of various commercially available wind turbines generators. The monthly and annual variation of capacity factors have been studied to ensure optimum selection of wind turbine generators.Wind energy Weibull parameters Capacity factor Wind data in Kingdom of Bahrain

Comparative resistance calculations for SLICE/SWATH hulls

Comparative resistance calculations are performed for SLICE and SWATH hulls. For the purposes of this study, the primary difference between these two hull types is in the underwater pods. It is assumed that both ship types have identical surface piercing struts, speed, and displacement. The underwater pods are continuous for the SWATH design and discontinuous for the SLICE. Resistance calculations are based on I.T.T.C. skin friction, empirical regression of existing experimental data for form drag, and surface singularities distribution for wavemaking. Results are presented for two cases, length limited where the overall length between the two hull types remains constant, and diameter limited where the pod diameter remains constant. Parametric studies in terms of pod geometry, separation distance, ship speed, displacement length ratio, and draft indicate that a SLICE hull may offer decreased resistance compared to a similar SWATH, depending on the range of the above design parameters. (AN)http://archive.org/details/comparativeresis1094531513NANABahrain Navy author

Investigation on different luminophores and sensor modelling techniques for gas sensing

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