Dispersive shock waves in the Kadomtsev-Petviashvili and Two Dimensional Benjamin-Ono equations

Dispersive shock waves (DSWs) in the Kadomtsev-Petviashvili (KP) equation and two dimensional Benjamin-Ono (2DBO) equation are considered using parabolic front initial data. Employing a front tracking type ansatz exactly reduces the study of DSWs in two space one time (2+1) dimensions to finding DSW solutions of (1+1) dimensional equations. With this ansatz, the KP and 2DBO equations can be exactly reduced to cylindrical Korteweg-de Vries (cKdV) and cylindrical Benjamin-Ono (cBO) equations, respectively. Whitham modulation equations which describe DSW evolution in the cKdV and cBO equations are derived in general and Riemann type variables are introduced. DSWs obtained from the numerical solutions of the corresponding Whitham systems and direct numerical simulations of the cKdV and cBO equations are compared with excellent agreement obtained. In turn, DSWs obtained from direct numerical simulations of the KP and 2DBO equations are compared with the cKdV and cBO equations, again with remarkable agreement. It is concluded that the (2+1) DSW behavior along parabolic fronts can be effectively described by the DSW solutions of the reduced (1+1) dimensional equations.Comment: 25 Pages, 16 Figures. The movies showing dispersive shock wave propagation in Kadomtsev-Petviashvili II and Two Dimensional Benjamin-Ono equations are available at https://youtu.be/AExAQHRS_vE and https://youtu.be/aXUNYKFlke

S-wave charmed mesons in lattice NRQCD

Heavy-light mesons can be studied using the 1/M expansion of NRQCD, provided the heavy quark mass is sufficiently large. Calculations of the S-wave charmed meson masses from a classically and tadpole-improved action are presented. A comparison of O(1/M), O(1/M^2) and O(1/M^3) results allows convergence of the expansion to be discussed. It is shown that the form of discretized heavy quark propagation must be chosen carefully.Comment: LATTICE98(heavyqk), 3 pages including 3 figure

Experimental investigation of the energy performance of a novel Micro-encapsulated Phase Change Material (MPCM) slurry based PV/T system

© 2015 Elsevier Ltd. As a follow-on work of the authors' theoretical study, the paper presented an experimental investigation into the energy performance of a novel PV/T thermal and power system employing the Micro-encapsulated Phase Change Material (MPCM) slurry as the working fluid. A prototype PV/T module of 800mm×1600mm×50mm was designed and constructed based on the previous modelling recommendation. The performance of the PV/T module and associated thermal and power system were tested under various solar radiations, slurry Reynolds numbers and MPCM concentrations. It was found that (1) increasing solar radiation led to the increased PV/T module temperature, decreased solar thermal and electrical efficiencies and reduced slurry pressure drop; (2) increasing the slurry Reynolds number led to the increased solar thermal and electrical efficiencies, decreased module temperature, and increased pressure drop; and (3) increasing the MPCM concentration led to the reduced module temperature and increased pressure drop. The experimental results were used to examine the accuracy of the established computer model, giving a derivation scale ranging from 1.1% to 6.1% which is an acceptable error level for general engineering simulation. The recommended operational conditions of the PV/T system were (1) MPCM slurry weight concentration of 10%, (2) slurry Reynolds number of 3000, and (3) solar radiation of 500-700W/m 2 ; at which the system could achieve the net overall solar efficiencies of 80.8-83.9%. To summarise, the MPCM slurry based PV/T thermal and power system is superior to conventional air-sourced heat pump systems (ASHP) and solar assisted heat pump systems (ISAHP), and has the potential to help reduce fossil fuel consumption and carbon emission to the environment

Investigation of electrical properties for cantilever-based piezoelectric energy harvester

In the present era, the renewable sources of energy, e.g., piezoelectric materials are in great demand. They play a vital role in the field of micro-electromechanical systems, e.g., sensors and actuators. The cantilever-based piezoelectric energy harvesters are very popular because of their high performance and utilization. In this research-work, an energy harvester model based on a cantilever beam with bimorph PZT-5A, having a substrate layer of structural steel, was presented. The proposed energy scavenging system, designed in COMSOL Multiphysics, was applied to analyze the electrical output as a function of excitation frequencies, load resistances and accelerations. Analytical modeling was employed to measure the output voltage and power under pre-defined conditions of acceleration and load resistance. Experimentation was also performed to determine the relationship between independent and output parameters. Energy harvester is capable of producing the maximum power of 1.16 mW at a resonant frequency of 71 Hz under 1g acceleration, having load resistance of 12 k Omega. It was observed that acceleration and output power are directly proportional to each other. Moreover, the investigation conveys that the experimental results are in good agreement with the numerical results. The maximum error obtained between the experimental and numerical investigation was found to equal 4.3%

A Nonparametric Framework for Online Stochastic Matching with Correlated Arrivals

The design of online algorithms for matching markets and revenue management settings is usually bound by the stochastic prior that the demand process is formed by a fixed-length sequence of queries with unknown types, each drawn independently. This assumption of {\em serial independence} implies that the demand of each type, i.e., the number of queries of a given type, has low variance and is approximately Poisson-distributed. This paper explores more general stochastic models for online edge-weighted matching that depart from the serial independence assumption. We propose two new models, \Indep and \Correl, that capture different forms of serial correlations by combining a nonparametric distribution for the demand with standard assumptions on the arrival patterns -- adversarial or random order. The \Indep model has arbitrary marginal distributions for the demands but assumes cross-sectional independence for the customer types, whereas the \Correl model captures common shocks across customer types. We demonstrate that fluid relaxations, which rely solely on expected demand information, have arbitrarily bad performance guarantees. In contrast, we develop new algorithms that essentially achieve optimal constant-factor performance guarantees in each model. Our mathematical analysis includes tighter linear programming relaxations that leverage distribution knowledge, and a new lossless randomized rounding scheme in the case of \Indep. In numerical simulations of the \Indep model, we find that tighter relaxations are beneficial under high-variance demand and that our demand-aware rounding scheme can outperform stockout-aware rounding

THE MODERATING ROLE OF CORPORATE IMAGE BETWEEN USER EXPERIENCE TOWARDS CUSTOMER LOYALTY: A STUDY ON INDIHOME BY TELKOM INDONESIA

The research titled “ (2013). This study aims to Tarus and Rabach ABSTRACT The Moderating Role of Corporate Image Between Influencing Factor of User Experience into Customer Loyalty: A Study on Indihome By Telkom Indonesia” has two variables and a moderator. The Independent variable; User Experience (X) that consists of Service Value, Service Quality, Customer Satisfaction, and Social Pressure. The Dependent Variable; Customer Loyalty (Y) that is customer loyalty. This research has a moderating role of corporate image (M). All of those variables are adapted from examine the influence of user experience towards customers loyalty as well as examines the moderating role of corporate image towards user experience towards customers loyalty of PT. Telekomunikasi Indonesia. The population used in this study are the customers of Indihome by PT. Non-Probability Sampling that gathers data from 400 respondents. This study conducted within August 2017 until April 2018. The research reveals that Service Value, Customer Satisfaction and Social Pressure are predictors of customer loyalty of Indihome. Furthermore, Social Pressure is the most powerful predictor compared to other predictors. The role of corporate image is proven to have a positive effect of moderator in between; Service Value towards Customer Loyalty, Customer Satisfaction towards Customer Loyalty, and Social Pressure towards Customer Loyalty. Keywords: Service Value, Service Quality, Customer Satisfaction, Social Pressure, Corporate Image, Customer loyalty

The Place and Importance of Associations in Strengthening Trade Unions

Developments in the globalization process play an important role in the power loss of trade unions. This situation reveals the problems of unionization in the current industrial relations system. At this point, associations with aspects similar to the trade unions and important non-governmental organizations (NGOs), have an important place in terms of understanding the position, the importance, and the functions of today's industrial relations system where different ways of solutions are sought for unionism. In this context, this investigation focuses on the role, importance and functions of associations in the protection and reinforcement of the existing forces of the trade unions.The investigation aims to evaluate the position, importance and the potential functions of the associations in development of new strategies for strengthening the trade unions, and to suggest new ideas on this direction. The topic (in the direction of the determined purpose) was evaluated under the titles of ‘change and transformation in trade unionism’, ‘new strategies discussed and developed in the process of strengthening the trade unions’, and ‘the associations in development of new strategies’. According to basic findings, in the process of the re-empowerment of trade unions, associations are emerging as important NGOs in the realization of positive scenarios and taking precautions against negative scenarios. In conclusion; besides unionization, importance should be attached to association in every matter. In this process, associations should function in the independent status, in the dependent status, and in the core status

Urban Form and Structure Explain Variability in Spatial Inequality of Property Flood Risk among US Counties

Understanding the relationship between urban form and structure and spatial variation of property flood risk has been a longstanding challenge in urban planning and city flood risk management. Yet limited data-driven insights exist regarding the extent to which variation in spatial inequality of property flood risk in cities can be explained by heterogenous features of urban form and structure. In this study, we explore eight key features (i.e., population density, point of interest density, road density, minority segregation, income segregation, urban centrality index, gross domestic product, and human mobility index) related to urban form and structure to explain variability in spatial inequality of property flood risk among 2567 US counties. Using rich datasets related to property flood risk, we quantify spatial inequality in property flood risk and delineate features of urban form and structure using high-resolution human mobility and facility distribution data. We identify significant variation in spatial inequality of property flood risk among US counties with coastline and metropolitan counties having the greatest spatial inequality of property flood risk. The results also reveal variations in spatial inequality of property flood risk can be effectively explained based on principal components of development density, economic activity, and centrality and segregation. Using a classification and regression tree model, we demonstrate how these principal components interact and form pathways that explain levels of spatial inequality in property flood risk in US counties. The findings offer important insights for the understanding of the complex interplay between urban form and structure and spatial inequality of property flood risk and have important implications for integrated urban design strategies to address property flood risk as cities continue to expand and develop

solveME: fast and reliable solution of nonlinear ME models.

BackgroundGenome-scale models of metabolism and macromolecular expression (ME) significantly expand the scope and predictive capabilities of constraint-based modeling. ME models present considerable computational challenges: they are much (>30 times) larger than corresponding metabolic reconstructions (M models), are multiscale, and growth maximization is a nonlinear programming (NLP) problem, mainly due to macromolecule dilution constraints.ResultsHere, we address these computational challenges. We develop a fast and numerically reliable solution method for growth maximization in ME models using a quad-precision NLP solver (Quad MINOS). Our method was up to 45 % faster than binary search for six significant digits in growth rate. We also develop a fast, quad-precision flux variability analysis that is accelerated (up to 60× speedup) via solver warm-starts. Finally, we employ the tools developed to investigate growth-coupled succinate overproduction, accounting for proteome constraints.ConclusionsJust as genome-scale metabolic reconstructions have become an invaluable tool for computational and systems biologists, we anticipate that these fast and numerically reliable ME solution methods will accelerate the wide-spread adoption of ME models for researchers in these fields

Robust Path Construction for Reliable Data Transmissions in Node Disjoint Multipath Routing

Wireless Sensor Networks (WSNs) are prone to node breakdowns due to energy constraints, which contribute to frequent topology changes. Moreover, since sensor nodes have restricted transmission range, multiple hops are needed by the node in order to forward the packets from one node to the other and this raises very challenging issues when designing routing protocols. Most of the proposed single path routing schemes use a periodic low-rate flooding of data in order to recover from path failures, which causes higher consumption in sensor node resources. So multipath routing is an optimal approach to enhance the network lifetime. In this paper, a robust path construction for a reliable data transmission in node-disjoint multipath routing (RNDMR) is proposed for WSNs. The proposed RNDMR has the ability to provide a low overhead path construction as well as provide data transmission reliability by using XOR-based coding algorithm, which entails low utilization of resources, such as low storage space and lesser computing power. In the proposed RNDMR, the procedure involves the splitting up of all transmitted messages into many different segments of equal size, before adding the XOR-based error correction codes and distributing it among multiple paths simultaneously in order to boost reliable data transmission and to be assured that the essential fragment of the packet arrives at the sink node without any additional consumption of energy and undue delay. By using simulations, the performance of RNDMR was assessed and compares it with ReInForm routing. The results illustrate that RNDMR attains low energy consumption, records low average delay and routing overhead, as well as increased packet delivery ratio when compared with ReInForm Routing