Models of Collapsing and Expanding Anisotropic Gravitating Source in f(R,T)f(R,T) Theory of Gravity

In this paper, we have formulated the exact solutions of the non-static anisotropic gravitating source in $f(R,T)$ gravity which may lead to expansion and collapse. By assuming the no thermal conduction in gravitating source, we have determine parametric solutions in $f(R,T)$ gravity with non-static spherical geometry filled with anisotropic fluid. We have examined the range of parameter for which expansion scalar become negative and positive leading to collapse and expansion, respectively. Further, using the definition of mass function the condition for the trapped surface have been explored and it has been investigated there exists a single horizon in this case. The impact of coupling parameter $\lambda$ has been discussed in detail in both cases. For the various values of coupling parameter $\lambda$, we have plotted energy density, anisotropic pressure and anisotropic parameter in case of collapse and expansion. The physical significance of the graphs has been explained in detail.Comment: 18 Pages, 8 Figures, Accepted for Publication in European Physical Journal

Taxation Reforms: a CGE-Microsimulation Analysis for Pakistan

This paper provides an ex ante assessment of taxation reforms being considered in Pakistan, in order to widen the tax base and rationalise the rate structure of different taxes. Amongst the main proposals, those focusing on sales tax and agricultural direct taxes seem relatively more attractive. The former has the highest share in indirect taxes and is also easier to collect, while the latter is intended to bring the presently exempted agricultural incomes into the tax net. As a first step, we study the general equilibrium effects of existing taxes by removing them from the system one at a time. In the second step we study the micro-macro impacts of four policy experiments: a) increasing sales tax rate by 33 percent; b) applying a 10 percent sales tax on presently zero-rated goods; c) increasing sales tax rate by 33 percent and bringing the services sectors in the sales tax net; and d) increasing sales tax rate by 33 percent, bringing the services sectors in the sales tax net, and imposing a 5 percent flat tax on agricultural incomes. In the third step we calculate the lost revenue due to evasion and avoidance. Results from experiments indicate the tough choices for policy makers in trying to improve the currently low tax to GDP ratio in Pakistan. Almost all simulations result in a decrease in investment levels, reduced consumption, and an increase in poverty. We thus recommend a gradual approach to tax reform that can make the adjustment process less painful.Taxation, Microsimulation, General Equilibrium, Poverty, Inequality, Progressivity, Redistribution

Far field imaging of a dielectric inclusion

A non-iterative topological sensitivity framework for guaranteed far field detection of a dielectric inclusion is presented. The cases of single and multiple measurements of the electric far field scattering amplitude at a fixed frequency are taken into account. The performance of the algorithm is analyzed theoretically in terms of resolution, stability, and signal-to-noise ratio.Comment: 6 pages, 5th International Workshop on New Computational Methods for Inverse Problems, ENS Cachan, Franc

Characterization of an 18F-Growth Hormone Secretagogue Probe for Positron Emission Tomography Imaging of the Growth Hormone Secretagogue Receptor

Cardiovascular disease affects 1.6 million Canadians, of whom one-third have heart failure (HF). HF is diagnosed by imaging investigations and detection of circulating biomarkers. Most of the current imaging strategies study morphologic and gross functional changes, but fall short of imaging molecular abnormalities associated with HF. Biomarkers offer molecular targets; however, clinical biomarkers circulate systemically and are not cardiac-specific. Thus, there is critical need for a biomarker that is endogenous to myocardial tissues. The growth hormone secretagogue receptor 1a (GHSR1a), which binds the hormone ghrelin, is expressed by cardiomyocytes and is elevated in HF patients. This study characterized the specificity of the novel tracer [1-Nal4, Lys5(4-[18F]-FB)]G-7039 to target GHSR1a using Positron Emission Tomography (PET). In vitro analysis of probe specificity by cellular uptake determined that binding was independent of receptor expression, which was confirmed by in vivo PET imaging in GHSR1a-wildtype (wt) and -knockout (ghsr-/-) mice. Ex vivo biodistribution comparing specificity and effects of nutritional state showed that [1-Nal4, Lys5(4-[18F]-FB)]G-7039 did not distribute to the heart and uptake was independent of circulating ghrelin levels. Although [1-Nal4, Lys5(4-[18F]-FB)]G-7039 demonstrated in vitro stability, negligible cardiac uptake and high uptake in the liver, intestines and kidneys within 1 h post-injection indicated rapid probe elimination through hepatobiliary and renal echanisms, possibly explained by a highly lipophilic tracer. Analysis of cardiac GHSR1a expression and metabolic markers by fluorescence microscopy in fasted, fed, wt and ghsr-/- mice suggests that there may be a ghrelin/GHSR1a system in the heart that is regulated independently of systemic ghrelin/GHSR1a, and that GHSR1a does not play a significant role in cardiac metabolism in healthy mice. In vitro stability and cellular uptake, ex vivo iodistribution and in vivo imaging conducted in this study present a step towards characterizing a suitable GHSR1a PET tracer that may be used to detect HF

Intelligent intrusion detection in low power IoTs

Security and privacy of data are one of the prime concerns in today’s Internet of Things (IoT). Conventional security techniques like signature-based detection of malware and regular updates of a signature database are not feasible solutions as they cannot secure such systems effectively, having limited resources. Programming languages permitting immediate memory accesses through pointers often result in applications having memory-related errors, which may lead to unpredictable failures and security vulnerabilities. Furthermore, energy efficient IoT devices running on batteries cannot afford the implementation of cryptography algorithms as such techniques have significant impact on the system power consumption. Therefore, in order to operate IoT in a secure manner, the system must be able to detect and prevent any kind of intrusions before the network (i.e., sensor nodes and base station) is destabilised by the attackers. In this article, we have presented an intrusion detection and prevention mechanism by implementing an intelligent security architecture using random neural networks (RNNs). The application’s source code is also instrumented at compile time in order to detect out-of-bound memory accesses. It is based on creating tags, to be coupled with each memory allocation and then placing additional tag checking instructions for each access made to the memory. To validate the feasibility of the proposed security solution, it is implemented for an existing IoT system and its functionality is practically demonstrated by successfully detecting the presence of any suspicious sensor node within the system operating range and anomalous activity in the base station with an accuracy of 97.23%. Overall, the proposed security solution has presented a minimal performance overhead.</jats:p

Organization of Multi-Agent Systems: An Overview

In complex, open, and heterogeneous environments, agents must be able to reorganize towards the most appropriate organizations to adapt unpredictable environment changes within Multi-Agent Systems (MAS). Types of reorganization can be seen from two different levels. The individual agents level (micro-level) in which an agent changes its behaviors and interactions with other agents to adapt its local environment. And the organizational level (macro-level) in which the whole system changes it structure by adding or removing agents. This chapter is dedicated to overview different aspects of what is called MAS Organization including its motivations, paradigms, models, and techniques adopted for statically or dynamically organizing agents in MAS.Comment: 12 page

Generic Development Concept and Costing for Marginal Field

The objectives of this study is to identify the latest approaches and technical advances associated with development of marginal offshore field and the innovations used to reduce overall field development cost. Also to develop a costing basis to evaluate quick estimation of development cost of a marginal field. Increasing oil demand pushes oil companies to find concepts, which considerably reduce the costs of marginal field developments and consequently make these developments economically feasible. The methodology adopted for this study is literature review. Review and analysis of actual marginal field development concepts, novel facilities, and criteria used for options selection and development strategies around the world. A Generic development concept of marginal offshore field development were reviewed in order to identify the suitable alternative options, project management strategies and innovative technology that can be used for conceptual development phase for marginal prospects. A definition and understanding of marginal fields was established, drilling development approach conventional and innovative methods were identified, and also conventional and novel facilities development concepts were reviewed. The development basic cost estimation method is carried out. The findings showed that factors such as the reserve, environmental and regulations conditions, market conditions, field development cost and proximity to host existing process platform determine the commercial viability of marginal prospects. The success of such prospects was found to be dependent on development strategy, applied technology and project execution. Cost, schedule and existing infrastructure were identified as the main drivers influencing the strategy selection and facilities viability. Strategies involving fast track developments, tie-back to host facilities, leasing of facilities and stand alone developments were highlighted as the preferred choices. The life –cycle cost is an important method in assessing the impact of new technology on marginal field economics. A guideline for selecting a marginal field development strategy was proposed