Power system harmonics estimation using different signal processing techniques

Harmonics have been available for quite a while and its presence shapes the execution of a power system. Consequently, harmonics estimation is of principal vitality while analyzing the power system. Emulating the beginning of harmonics, different filters have been formulated to attain an ideal control methodology for constant rejection. This thesis acquaints different algorithms to dissect harmonics in the power system. The target is to estimate the voltage magnitude and phase plot of the power system in the proximity of noise by using various estimation approaches. This thesis has centered the consideration towards the investigation of Kalman filter (KF), Recursive Least squares (RLS), least mean square (LMS) and Variable leaky least mean square (VLLMS) based filter for estimation of harmonics. For a test signal KF, RLS, LMS and VLLMS based calculations have been examined and the results have been looked at. The several algorithms are compared for various signals to noise ratio. The SNR used here are 40 dB, 30dB and 20dB. The proposed estimation methodologies are implemented on a typical power system signal acquired from mechanical burden embodying power electronic converters and arc furnaces

Passenger transmission and productiveness of transit lines with high loads

Deterministic transit capacity analysis applies to planning, design and operational management of urban transit systems. The Transit Capacity and Quality of Service Manual (1) and Vuchic (2, 3) enable transit performance to be quantified and assessed using transit capacity and productive capacity. This paper further defines important productive performance measures of an individual transit service and transit line. Transit work (p-km) captures the transit task performed over distance. Passenger transmission (p-km/h) captures the passenger task delivered by service at speed. Transit productiveness (p-km/h) captures transit work performed over time. These measures are useful to operators in understanding their services’ or systems’ capabilities and passenger quality of service. This paper accounts for variability in utilized demand by passengers along a line and high passenger load conditions where passenger pass-up delay occurs. A hypothetical case study of an individual bus service’s operation demonstrates the usefulness of passenger transmission in comparing existing and growth scenarios. A hypothetical case study of a bus line’s operation during a peak hour window demonstrates the theory’s usefulness in examining the contribution of individual services to line productive performance. Scenarios may be assessed using this theory to benchmark or compare lines and segments, conditions, or consider improvements

Impact of Channel Correlation on Different Performance Metrics of OSSK-Based FSO System

In this paper, we study the impact of correlation on the bit error rate (BER) and the channel capacity of a free-space optical (FSO) multiple-input-multiple-output (MIMO) system employing optical space shift keying (OSSK) over a fading channel. In order to study a practical correlated channel, we consider the effect of channel correlation due to both small-and large-scale eddies and show that the use of OSSK over correlated FSO channel can lead to an improved system performance with increasing correlation level of upto 0.9. In this work, we first develop an analytical framework for different performance metrics of the OSSK multiple-input single-output system with correlation and then extend our investigation by proposing an asymptotically accurate mathematical framework for MIMO. We also validate all the analytical results using MATLAB simulations. Finally, we develop an experimental setup of FSO with two correlated links to study the throughput and latency of the links at different turbulence levels

Analysis and Performance Evaluation of IEEE 802.11 WLAN

With fast deployment of wireless local area networks VoIP over IEEE 802.11 wireless local area network (WLAN) is growing very fast and is providing a cost effective alternative for voice communications. WLANs were initially set up to handle bursty nonreal time type of data traffic. Therefore, the wireless access protocols initially defined are not suitable for voice traffic. Subsequently, updates in the standard have been made to provision for QoS requirements of data, especially the real time traffic of the type voice and video. Despite these updates, however, transmitting voice traffic over WLAN does not utilize the available bandwidth (BW) efficiently, and the number of simultaneous calls supported in practice is significantly lower than what the BW figures would suggest. Several modifications have been proposed to improve the call capacity, and recently isochronous coordination function (ICF) was introduced to mitigate the problem of low call capacity. The proposed modified ICF which further improves the performance in terms of the call capacity. The proposed scheme uses multiplexing and multicasting in the downlink to substantially increase the call capacity

A tight lower bound instance for k-means++ in constant dimension

The k-means++ seeding algorithm is one of the most popular algorithms that is used for finding the initial $k$ centers when using the k-means heuristic. The algorithm is a simple sampling procedure and can be described as follows: Pick the first center randomly from the given points. For $i > 1$, pick a point to be the $i^{th}$ center with probability proportional to the square of the Euclidean distance of this point to the closest previously $(i-1)$ chosen centers. The k-means++ seeding algorithm is not only simple and fast but also gives an $O(\log{k})$ approximation in expectation as shown by Arthur and Vassilvitskii. There are datasets on which this seeding algorithm gives an approximation factor of $\Omega(\log{k})$ in expectation. However, it is not clear from these results if the algorithm achieves good approximation factor with reasonably high probability (say $1/poly(k)$). Brunsch and R\"{o}glin gave a dataset where the k-means++ seeding algorithm achieves an $O(\log{k})$ approximation ratio with probability that is exponentially small in $k$. However, this and all other known lower-bound examples are high dimensional. So, an open problem was to understand the behavior of the algorithm on low dimensional datasets. In this work, we give a simple two dimensional dataset on which the seeding algorithm achieves an $O(\log{k})$ approximation ratio with probability exponentially small in $k$. This solves open problems posed by Mahajan et al. and by Brunsch and R\"{o}glin.Comment: To appear in TAMC 2014. arXiv admin note: text overlap with arXiv:1306.420

Selenium in storage proteins of wheat cultivated on selenium impacted soils of Punjab, India

Wheat, an important staple cereal crop cultivated in seleniferous region of India, noted to accumulated significantly high concentrations of Se, was examined for the distribution of selenium in various protein fractions of the grains. Amongst the protein fractions, Se was dominantly (33–37%) present in the albumin fraction in Se rich grains followed by other fractions viz., globulin (20–25%), glutelin (20–25%), and prolamin (17–20%). The observations are important in context of exploring the use of this material as functional foods in formulating Se-enriched diets for Se-deficient population

EFFECT OFCO-ADMINISTRATION OF EMBLICA OFFICINALIS AND AEGLE MARMELOS EXTRACTS FOR ANTIOXIDANT AND ANTIDIABETIC ACTIVITY

Objective: The objective of the present study was to develop an HPLC analytical method and to perform in vivo study of Emblica officinalis and Aegle marmelos extracts for antioxidant and antidiabetic activity. Methods: The phytochemical analyses, total phenolic content (TPC), TLC, DPPH assay were performed for freeze-dried Emblica officinalis fruits aqueous extract (EOFAE) and Aegle marmelos leaves ethyl acetate extract (AMLEAE). The active constituents present in both extracts were estimated by using HPLC system having Hibar® C18 column [250 x4.6 mm, 5 µm] and UV detector (264 nm). A gradient mobile phase (acetonitrile and water with 0.1% trifluoroacetic acid) was used at a flow rate of 0.8 ml/min. In vivo antioxidant, antidiabetic activity of both extracts was conducted on male albino Wistar rats for 21 d in streptozotocin-induced diabetic rats (42 rats; n=6). The antidiabetic activity was measured by blood glucose level and biochemical parameters i.e. total cholesterol, triglycerides and total protein. Oxidative stress was measured by antioxidant biomarkers i.e. SOD, GSH, lipid peroxidation by thiobarbituric acid reactive substances method on the liver of the experimental rat. Results: Tannins, saponins, carbohydrate, glycosides are found in EOFAE; coumarins and flavonoids are found in AMLEAE and quinones, phenols are present in both extracts. The values of TPC present in standard gallic acid, EOFAE and AMLEAE were found to be 485.7, 315.6, 300.7 mgGAE/g, respectively. Rf values obtained by TLC of EOFAE and AMLEAE were found to be 0.41 and 0.50, respectively. The values of % inhibition shown by EOFAE and AMLEAE in DPPH assay were found to be 97.8%±2 and 95.2%±2, respectively. The values of retention time of EOFAE and AMLEAE by HPLC analysis were found to be 4.59 and 5.28 min, respectively. Histopathological examination of the liver was revealed that low dose EOAM (containing of EOFAE 250+AMLEAE 250 mg/kg body weight) administered once a daily for 21 d showed significant activity (P˂0.001) with biochemical parameters and antioxidant biomarkers. Conclusion: The present study showed that the EOFAE and AMLEAE treated group III with (EOAM) low dose of 500 mg/kg body weight has potent antioxidant and antidiabetic activity