Semi-Weakly Continuity of Maps in ‎Bitopological Spaces

في هذا البحث تم دراسة خواص الدوال شبه ضعيفة الاستمرارية في الفضاءات ثنائية التبولوجي .The author study in this paper, properties of semi-weakly continuous of maps in bio topological spaces

Separation Framework: An Enabler for Cooperative and D2D Communication for Future 5G Networks

Soaring capacity and coverage demands dictate that future cellular networks need to soon migrate towards ultra-dense networks. However, network densification comes with a host of challenges that include compromised energy efficiency, complex interference management, cumbersome mobility management, burdensome signaling overheads and higher backhaul costs. Interestingly, most of the problems, that beleaguer network densification, stem from legacy networks' one common feature i.e., tight coupling between the control and data planes regardless of their degree of heterogeneity and cell density. Consequently, in wake of 5G, control and data planes separation architecture (SARC) has recently been conceived as a promising paradigm that has potential to address most of aforementioned challenges. In this article, we review various proposals that have been presented in literature so far to enable SARC. More specifically, we analyze how and to what degree various SARC proposals address the four main challenges in network densification namely: energy efficiency, system level capacity maximization, interference management and mobility management. We then focus on two salient features of future cellular networks that have not yet been adapted in legacy networks at wide scale and thus remain a hallmark of 5G, i.e., coordinated multipoint (CoMP), and device-to-device (D2D) communications. After providing necessary background on CoMP and D2D, we analyze how SARC can particularly act as a major enabler for CoMP and D2D in context of 5G. This article thus serves as both a tutorial as well as an up to date survey on SARC, CoMP and D2D. Most importantly, the article provides an extensive outlook of challenges and opportunities that lie at the crossroads of these three mutually entangled emerging technologies.Comment: 28 pages, 11 figures, IEEE Communications Surveys & Tutorials 201

Intracell interference characterization and cluster interference for D2D communication

The homogeneous spatial Poisson point process (SPPP) is widely used for spatial modeling of mobile terminals (MTs). This process is characterized by a homogeneous distribution, complete spatial independence, and constant intensity measure. However, it is intuitive to understand that the locations of MTs are neither homogeneous, due to inhomogeneous terrain, nor independent, due to homophilic relations. Moreover, the intensity is not constant due to mobility. Therefore, assuming an SPPP for spatial modeling is too simplistic, especially for modeling realistic emerging device-centric frameworks such as device-to-device (D2D) communication. In this paper, assuming inhomogeneity, positive spatial correlation, and random intensity measure, we propose a doubly stochastic Poisson process, a generalization of the homogeneous SPPP, to model D2D communication. To this end, we assume a permanental Cox process (PCP) and propose a novel Euler-Characteristic-based approach to approximate the nearest-neighbor distribution function. We also propose a threshold and spatial distances from an excursion set of a chi-square random field as interference control parameters for different cluster sizes. The spatial distance of the clusters is incorporated into a Laplace functional of a PCP to analyze the average coverage probability of a cellular user. A closed-form approximation of the spatial summary statistics is in good agreement with empirical results, and its comparison with an SPPP authenticates the correlation modeling of D2D nodes

Fracture toughness of kenaf mat reinforced polyester composite

The fracture behaviour represents the most critical issue in the automotive and aerospace engine fields. Thus, the objective of this study was to estimate and analyze the crack criteria by using the Mathematical laws that were limited in E 1820 standard and the results affirmed by applying the numerical solutions of ANSYS to estimate the fracture toughness value KIC, besides the energy release rate of biomass composite. The specimens were prepared from different percentage of kenaf mat (KM) and unsaturated polyester resin (UP) 20% KM – 80% UP and 40% KM – 60% UP, respectively, as well the other composite properties which were calculated using the stress-strain data. The fracture characterizations of this composite were carried out using the compact tension (CT) specimen that was commonly used to determine Mode-I fracture properties. The fracture toughness has been found to be independent of pre-crack length. Meanwhile, the tests were performed at room temperature. The numerical simulations of the ANSYS model results demonstrated a good agreement between the experiments computed results of the fracture toughness. The fracture toughness KIC of 20% KM – 80% UP and 40% KM – 60% UP was equivalent to 0.76 MPa√m and 2.0 MPa√m, respectively. Thus, the fracture propagation is dependent on the fibre percentage of the composite. On the other hand, there are unlimited mechanisms of crack paths derived from randomly kenaf mat packs, particularly in the frontal process zone of crack tip

Spatial and Social Paradigms for Interference and Coverage Analysis in Underlay D2D Network

The homogeneous Poisson point process (PPP) is widely used to model spatial distribution of base stations and mobile terminals. The same process can be used to model underlay device-to-device (D2D) network, however, neglecting homophilic relation for D2D pairing presents underestimated system insights. In this paper, we model both spatial and social distributions of interfering D2D nodes as proximity based independently marked homogeneous Poisson point process. The proximity considers physical distance between D2D nodes whereas social relationship is modeled as Zipf based marks. We apply these two paradigms to analyze the effect of interference on coverage probability of distance-proportional power-controlled cellular user. Effectively, we apply two type of functional mappings (physical distance, social marks) to Laplace functional of PPP. The resulting coverage probability has no closed-form expression, however for a subset of social marks, the mark summation converges to digamma and polygamma functions. This subset constitutes the upper and lower bounds on coverage probability. We present numerical evaluation of these bounds on coverage probability by varying number of different parameters. The results show that by imparting simple power control on cellular user, ultra-dense underlay D2D network can be realized without compromising the coverage probability of cellular user.Comment: 10 pages, 10 figure

Development of radiolabeled fatty acid derivatives for imaging cardiac metabolism using PET and SPECT

Cardiac diseases are the leading cause of death worldwide. To address this problem, a better understanding of biochemical reasons underlying heart pathologies is needed. Fatty acid oxidation (FAO) plays a significant role in cardiac energy production and is therefore an important biomarker for heart disease. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are useful methods to quantify and qualify cardiac metabolic changes during either establishment of disease or therapeutic intervention. The extent of fatty acid oxidation can be visualised using radiolabeled thia-fatty acids. However, the uptake of these tracers as revealed by imaging also depends on their transport into cardiac cell mitochondria and general pharmacokinetics.In this work, the synthesis of four types of 4-thia fatty acids, 4-thiacaprylic acid/caprylate derivatives (TCD1), 4-thiacapric acid/caprate derivatives (TCD2), 4- thiapalmitic acid/palmitate derivatives (TPD) and 4-thiaoleic acid/oleate derivatives (TOD) is described.Fluorine-18 radiolabeling for the caprate, palmitate and oleate derivatives was optimised. The decay corrected radiochemical yields for the radiotracers, [18F]FTC2, [18F]FTP and [18F]FTO are 16.15 ± 2.60%, 18 ± 1.20% and 17.70 ± 1.70% respectively. [18F]FTP, [18F]FTO and [18F]FTC2 were found to be stable in serum after 3h at 37°C. PET imaging experiments in rats showed significant cardiac uptake for [18F]FTP and [18F]FTO but not for [18F]FTC2.A thia-fatty acid delivery method to increase cardiac cell uptake was investigated, based on their coordination to mitochondria targeted transition metal complexes. The cross-bridged cyclam precursor compounds were produced in good yields and novel copper(II) cross-bridged cyclam complexes with a triphenylphosphonium moiety for mitochondria targeting were synthesised. Coordination of radiolabeled thiacapric acid to the complexes was attempted.Novel 99mTc radiolabeled long chain thia-fatty acids (palmitic and oleic acids) were investigated as potential new radiopharmaceuticals for use in fatty acid oxidation imaging, which would be metabolised by β-oxidation. The intermediate derivatives were synthesised in good yields and fully characterised to obtain the precursors for radiolabeling and to provide reference compounds. 99mTc radiolabeled TACN –thia palmitic and thiaoleic acid were produced

Gender Differences in the Use of Hedging Devices in the Pakistani Opinion Columns: A Corpus-Based Study

This study investigates the use of hedges in the opinion columns written by Pakistani male columnists and female columnists. For this, the present study uses Hyland (2004) model interpersonal metadiscourse to recognize hedging devices. This study also investigates how or both genders show difference and similarity in the employment of hedges. The corpus was built of 580 opinion articles. The columns totaled 290 by male and 290 by female writers. For the present study, a mixed method approach was used. As for sampling, this study uses random sampling. The finding of this research reveals that both Pakistani male and female writers did not differ in the use of hedges devices in their opinion columns and concludes that the choice and distribution of hedges depend on genre of the text rather than on the gender of the text

Collaborative Spectrum Sensing Based on Upper Bound on Joint PDF of Exreme Eigenvalues

Detection based on eigenvalues of received signal covariance matrix is currently one of the most effective solution for spectrum sensing problem in cognitive radios. However, the results of these schemes often depend on asymptotic assumptions since the distribution of ratio of extreme eigenvalues is exceptionally mathematically complex to compute in practice. In this paper, a new approach to determine the distribution of ratio of the largest and the smallest eigenvalues is introduced to calculate the decision threshold and sense the spectrum. In this context, we derive a simple and analytically tractable expression for the distribution of the ratio of the largest and the smallest eigenvalues based on upper bound on the joint probability density function (PDF) of the largest and the smallest eigenvalues of the received covariance matrix. The performance analysis of proposed approach is compared with the empirical results. The decision threshold as a function of a given probability of false alarm is calculated to illustrate the effectiveness of the proposed approach

Eigenvalue Ratio Detection Based on Exact Moments of Smallest and Largest Eigenvalues

Detection based on eigenvalues of received signal covariance matrix is currently one of the most effective solution for spectrum sensing problem in cognitive radios. However, the results of these schemes always depend on asymptotic assumptions since the close-formed expression of exact eigenvalues ratio distribution is exceptionally complex to compute in practice. In this paper, non-asymptotic spectrum sensing approach to approximate the extreme eigenvalues is introduced. In this context, the Gaussian approximation approach based on exact analytical moments of extreme eigenvalues is presented. In this approach, the extreme eigenvalues are considered as dependent Gaussian random variables such that the joint probability density function (PDF) is approximated by bivariate Gaussian distribution function for any number of cooperating secondary users and received samples. In this context, the definition of Copula is cited to analyze the extent of the dependency between the extreme eigenvalues. Later, the decision threshold based on the ratio of dependent Gaussian extreme eigenvalues is derived. The performance analysis of our newly proposed approach is compared with the already published asymptotic Tracy-Widom approximation approach