Non-Markovian incoherent quantum dynamics of a two-state system

We present a detailed study of the non-Markovian two-state system dynamics for the regime of incoherent quantum tunneling. Using perturbation theory in the system tunneling amplitude $\Delta$, and in the limit of strong system-bath coupling, we determine the short time evolution of the reduced density matrix and thereby find a general equation of motion for the non-Markovian evolution at longer times. We relate the nonlocality in time due to the non-Markovian effects with the environment characteristic response time. In addition, we study the incoherent evolution of a system with a double-well potential, where each well consists several quantized energy levels. We determine the crossover temperature to a regime where many energy levels in the wells participate in the tunneling process, and observe that the required temperature can be much smaller than the one associated with the system plasma frequency. We also discuss experimental implications of our theoretical analysis.Comment: 10 pages, published versio

Development of optical data processing techniques applicable to detection and study of meteor trails

Development of coherent optical data processing techniques applicable to detection of meteor trails and examination of propertie

Corotation Resonance and Diskoseismology Modes of Black Hole Accretion Disks

We demonstrate that the corotation resonance affects only some non-axisymmetric g-mode oscillations of thin accretion disks, since it is located within their capture zones. Using a more general (weaker radial WKB approximation) formulation of the governing equations, such g-modes, treated as perfect fluid perturbations, are shown to formally diverge at the position of the corotation resonance. A small amount of viscosity adds a small imaginary part to the eigenfrequency which has been shown to induce a secular instability (mode growth) if it acts hydrodynamically. The g-mode corotation resonance divergence disappears, but the mode magnitude can remain largest at the place of the corotation resonance. For the known g-modes with moderate values of the radial mode number and axial mode number (and any vertical mode number), the corotation resonance lies well outside their trapping region (and inside the innermost stable circular orbit), so the observationally relevant modes are unaffected by the resonance. The axisymmetric g-mode has been seen by Reynolds & Miller in a recent inviscid hydrodynamic accretion disk global numerical simulation. We also point out that the g-mode eigenfrequencies are approximately proportional to m for axial mode numbers |m|>0.Comment: 16 pages, no figures. Submitted to The Astrophysical Journa

Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

Local community on trial

While plenty has been written about the reinvention of the social by the Third Way as a new governmentality of control, consensus, and social integration, less has been said about its subtle elision of social and the local, and the implications of this elision for urban and regional regeneration. This is the theme taken up by this paper, beginning with a critical appraisal of the recent turn by New Labour to community cohesion and social capital as a means of overcoming local poverty and disadvantage. It shows how the social has come to be redefined as community, localized, and thrown back at hard-pressed areas as both cause and solution in the area of social, political, and economic regeneration. The second half of the paper develops an alternative designation of the local-social that is less instrumentalist, decidedly a-moral (though equally ethical), agonistically political, and geographically unconstrained. It argues for a return to ideas of agonistic democracy and the society of commitments and connections so thoroughly repudiated by new versions of market social democracy

Thermally assisted adiabatic quantum computation

We study the effect of a thermal environment on adiabatic quantum computation using the Bloch-Redfield formalism. We show that in certain cases the environment can enhance the performance in two different ways: (i) by introducing a time scale for thermal mixing near the anticrossing that is smaller than the adiabatic time scale, and (ii) by relaxation after the anticrossing. The former can enhance the scaling of computation when the environment is superohmic, while the latter can only provide a prefactor enhancement. We apply our method to the case of adiabatic Grover search and show that performance better than classical is possible with a superohmic environment, with no a priori knowledge of the energy spectrum.Comment: 4 pages, 2 figures, Final version to appear in PR

Systematic Topology Analysis and Generation Using Degree Correlations

We present a new, systematic approach for analyzing network topologies. We first introduce the dK-series of probability distributions specifying all degree correlations within d-sized subgraphs of a given graph G. Increasing values of d capture progressively more properties of G at the cost of more complex representation of the probability distribution. Using this series, we can quantitatively measure the distance between two graphs and construct random graphs that accurately reproduce virtually all metrics proposed in the literature. The nature of the dK-series implies that it will also capture any future metrics that may be proposed. Using our approach, we construct graphs for d=0,1,2,3 and demonstrate that these graphs reproduce, with increasing accuracy, important properties of measured and modeled Internet topologies. We find that the d=2 case is sufficient for most practical purposes, while d=3 essentially reconstructs the Internet AS- and router-level topologies exactly. We hope that a systematic method to analyze and synthesize topologies offers a significant improvement to the set of tools available to network topology and protocol researchers.Comment: Final versio

Eicosapentaenoic Acid (EPA) from Fish Oil and Margarine as Bioactive Compound for Anti-inflammation in Occupational Dermatitis

Occupational dermatitis (OCD) is a skin inflammatory disease caused by allergens and irritant agents in the workplace. The disease is related to hypersensitivity reaction, which is correlated with an immunological mechanism (allergic contact dermatitis) and a nonimmunological mechanism (irritant contact dermatitis). Patients with atopic history (rhinitis allergy, asthma, and atopic dermatitis) have a higher risk of contracting OCD. Atopic individuals suffer from barrier skin damage that increases the risk of allergen and irritant penetration. Inflammatory reaction involves T-helper 1 (Th1), which produces cytokine tumor necrosis factor alpha (TNF-α) and interferon-γ (INF-γ), while T-helper 2 (Th2) produces interleukin (IL-4, IL-6, IL-8, IL-10). Eicosapentaenoic acid (EPA) is an omega-3 substance from polyunsaturated free fatty acids (PUFAs)that has been shown to have an anti-inflammatory effect and the ability to decrease macrophage accumulation. In the inflammatory process, EPA inhibits IL-6, IL-8, and TNF-α, which are mediated by the free fatty acid-binding proteins (FABPs). The aim of this study was to determine the bioactivity compound of EPA for anti-inflammatory agents and its target, based on in silico screening. The bioinformatic tools based on reverse docking used in this study were the PubChem compound database, the protein target prediction database, PharmMapper, SwissTargetPrediction, molecular docking software PyRx 0.8, ligand docking, and binding site analysis using PyMOL software. Docking and binding site analysis showed that EPA was able to interact withFABPs, with the binding affinity of EPA with FABP 4 higher (–4.2 kcal/mol) than that of hydrocortisone with FABP 4 (–7.4 kcal/mol). EPA has the same binding site and relative bonding power as the FABPs; thus, it has potential as an alternative anti-inflammatory medicine in OCD. Keywords: occupational dermatitis, eicosapentaenoic acid (EPA), free fatty acid binding proteins (FABPs), reverse dockin