A Study on Principal Component Analysis over Wireless Channel

Applications in many fields such as the internet of things (IoT), stock market, image compression, food adulteration, wireless physical layer key generation, etc. are becoming progressively complex due to a large number of users and increment in their usage. Data obtained by these applications are in huge amount creating a high computational cost. Further, it is difficult to handle and analyze it. To deal with such problems, dimensionality reduction techniques are used and one of the dimensionality reduction techniques is the Principal Component Analysis (PCA). In this paper, PCA is applied over a wireless Rician channel with AWGN at different SNR. It is concluded that the information content is more in less number of principal components with samples at higher SNR. It is also observed that the different combinations of several groups and elements in the sample space provide a different cumulative percentage of information

Effects of dissipation on disordered quantum spin models

We study the effects of the coupling to an Ohmic quantum reservoir on the static and dynamical properties of a family of disordered SU(2) spin models in a transverse magnetic field using a method of direct spin summation. The tendency to form a glassy phase increases with the strength of the coupling of the system to the environment. We study the influence of the environment on the features of the phase diagram of the various models as well as the stability of the possible phases.Comment: 24 pages, 8 fig

Exchange Monte Carlo Method and Application to Spin Glass Simulations

We propose an efficient Monte Carlo algorithm for simulating a ``hardly-relaxing" system, in which many replicas with different temperatures are simultaneously simulated and a virtual process exchanging configurations of these replica is introduced. This exchange process is expected to let the system at low temperatures escape from a local minimum. By using this algorithm the three-dimensional $\pm J$ Ising spin glass model is studied. The ergodicity time in this method is found much smaller than that of the multi-canonical method. In particular the time correlation function almost follows an exponential decay whose relaxation time is comparable to the ergodicity time at low temperatures. It suggests that the system relaxes very rapidly through the exchange process even in the low temperature phase.Comment: 10 pages + uuencoded 5 Postscript figures, REVTe

Increasing of entanglement entropy from pure to random quantum critical chains

It is known that the entropy of a block of spins of size $L$ embedded in an infinite pure critical spin chain diverges as the logarithm of $L$ with a prefactor fixed by the central charge of the corresponding conformal field theory. For a class of strongly random spin chains, it has been shown that the correspondent block entropy still remains universal and diverges logarithmically with an "effective" central charge. By computing the entanglement entropy for a family of models which includes the $N$-states random Potts chain and the $Z_N$ clock model, we give some definitive answer to some recent conjectures about the behaviour of the effective central charge. In particular, we show that the ratio between the entanglement entropy in the pure and in the disordered system is model dependent and we provide a series of critical models where the entanglement entropy grows from the pure to the random case.Comment: 4 pages, 2 eps figures, added reference

Probable binary open star clusters in the galaxy

The existence of double/binary clusters in the Magellanic Clouds is fairly well established, whereas only one such pair, h + χ Persei, is known in the Galaxy. From the catalogues of open clusters of the Galaxy, we have identified 18 probable pairs of clusters (with known distances), with spatial separations less than 20pc. The tidal disruption timescales for these pairs, due to Galactic differential rotation are calculated, using cluster data where available or by assuming typical values. In some cases, these timescales are larger than the average open cluster lifetime, ≈108yr. About 8% of open clusters appear to be members of binary systems, and hence binary cluster systems may not be very uncommon in the Galaxy

Low Complexity Security Algorithm for CPS / IoT Networks

Due to its noisy nature, wireless channel plays a dominant role in deciding the performance of data communication between the smart objects in the cyberphysical systems (CPS) or the internet of things (IoT). Open and heterogeneous nature of these networks makes them susceptible to vulnerable attacks. So, to keep up the confidentiality and integrity of the transmitted data against the adversaries, it should be secured before transmission. However, issues such as power efficiency, low computational complexity need to be considered when designing security algorithms for CPS/IoT networks. Traditional encryption algorithms, such as Advanced Encryption Standard (AES), International Data Encryption Algorithm (IDEA) can be used for security purpose, but they do not satisfy power and complexity criteria as per CPS/IOT networks requirements. Moreover, they exhibit poor bit error ratio (BER) performance in a noisy wireless channel. This paper presents a modified security algorithm, AES-P, with X-OR mapping on AES to make them suitable for CPS/IoT applications. Simulation and analysis of the proposed algorithm showed that its power consumption and complexity are reduced as compared to traditional AES. It also performed better in the wireless channel, while maintaining the required security level satisfied by Avalanche effect

Cadmium induced oxidative stress-mediated pathophysiological alterations in chickens and their amelioration by polyherbal mixture enriched feed

41-53The study was conducted to evaluate sub-acute toxicity of cadmium (Cd) in broiler chickens and its amelioration by polyherbal mixture enriched feed (PHMEF). Thirty broiler chickens were divided into five groups. Chickens of group 1 were kept as control (C1). Chickens of group T1, T2, T3 and T4 were exposed to cadmium (as cadmium chloride) through drinking water (100 ppm), Vitamin C with Vitamin E (250 mg/kg each) in feed + Cd in drinking water (100 ppm), PHMEF (2%) alone, and PHMEF (2%) + cadmium in drinking water (100 ppm) for 28 days, respectively. Haematology, serum biochemical parameters, oxidative stress parameters like superoxide dismutase, catalase, reduced-glutathione and malondialdehyde, cadmium accumulation in organs like kidney, liver and thigh muscle, scanning electron microscopy (SEM) of ileum, and histopathological examination of kidney, liver and intestine were performed to evaluate toxicity of cadmium and ameliorating potential of PHMEF in broiler chickens. PHMEF modifies biochemical parameters, and oxidative stress markers. There was a significant reduction of cadmium accumulations in the PHMEF treated group. Polyherbal mixture enriched feed showed ameliorating effect against cadmium induced toxicity due to antioxidant effect as well as effect on accumulation of the cadmium in chickens

SAO 75669: A late type giant behind the molecular cloud MBM 12

Photometric and spectroscopic observations of the star SAO 75669 in the region of the high galactic latitude molecular cloud MBM 12 are presented. The optical, near-infrared and far-infrared IRAS photometric magnitudes together with the observed CCD spectrum and the large degree of polarization are consistent with the star being and M type giant behind the molecular cloud MBM 12 suffering about 1.8 magnitudes visual extinction. The wavelength dependence of polarization indicates that the dust in the cloud is normal

Structural Probe of a Glass Forming Liquid: Generalized Compressibility

We introduce a new quantity to probe the glass transition. This quantity is a linear generalized compressibility which depends solely on the positions of the particles. We have performed a molecular dynamics simulation on a glass forming liquid consisting of a two component mixture of soft spheres in three dimensions. As the temperature is lowered (or as the density is increased), the generalized compressibility drops sharply at the glass transition, with the drop becoming more and more abrupt as the measurement time increases. At our longest measurement times, the drop occurs approximately at the mode coupling temperature $T_C$. The drop in the linear generalized compressibility occurs at the same temperature as the peak in the specific heat. By examining the inherent structure energy as a function of temperature, we find that our results are consistent with the kinetic view of the glass transition in which the system falls out of equilibrium. We find no size dependence and no evidence for a second order phase transition though this does not exclude the possibility of a phase transition below the observed glass transition temperature. We discuss the relation between the linear generalized compressibility and the ordinary isothermal compressibility as well as the static structure factor.Comment: 18 pages, Latex, 26 encapsulated postscript figures, revised paper is shorter, to appear in Phys. Rev.