222 research outputs found

    Study Of Inhomogeneous Dielectric Resonators For Linearly Circularly Polarized Microwave Antenna Applications

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    In the last three decades a huge amount research has been dedicated to homogeneous (single permittivity) dielectric resonators (DRs) with cylindrical, rectangular/square and hemispherical shapes being the center of attention. These DRs have been investigated theoretically, numerically, and experimentally therefore, all the major performance controlling parameters are known for the homogeneous DRs. It well known that a homogenous DR can serve only one purpose at a time i.e. strong coupling to the source and hence narrow impedance bandwidth and vice versa. To overcome these drawbacks of homogenous DRs, in this work inhomogeneous DRs are designed in such a way that the basic geometry of the resonator is maintained so that the available theoretical, numerical and experimental analysis tools can be effectively applied to the proposed inhomogeneous DRs. The inhomogeneities in the resonators are introduced systematically in the azimuth (ϕ) direction so that the electromagnetic field distribution in the resonators remains the same with different range of energy confinement. To validate these ideas three different resonators based on cylindrical dielectric resonator (CDR) and rectangular/square shape resonators are investigated. For inhomogeneous CDR two 90ᴼ pie shape sectors of relatively high permittivity were introduced in the ϕ-direction in a way that sectors with same permittivity are placed in the opposite quadrant. Similarly, another inhomogeneous DR (split-oval shape) was designed by inserting high permittivity rectangular strip in the middle of two half cylindrical DR in the ϕ direction. Lastly, the third design of this research is based on a square shape DR in which the permittivity is lowered by introducing air-gap within the resonator which appears like a nested square DR. The proposed inhomogeneous DRs are tested for linearly polarized (LP) wideband antenna applications with a common excitation technique i.e. microstrip line. While, for circularly polarized (CP) designs, it is important to excite two orthogonal modes with the same amplitude hence different feeding techniques are used. Theoretical, numerical and experimental analysis of the inhomogeneous dielectric resonator antennas (DRA) showed that by properly designing inhomogeneous resonators, impedance bandwidth response, axial ratio (AR) bandwidth, gain and efficiency of the DRA‘s can be improved. For all three inhomogeneous LP DRA‘s approximately 56% impedance bandwidth was achieved which shows 80.5% enhancement of bandwidth over homogeneous DRAs with stable radiation characteristics throughout the operating band. The AR bandwidth response of the CP inhomogeneous DRA‘s was recorded to be 200% more than that of homogeneous counterparts. For the first two inhomogeneous DRAs gain was improved up to 6.5 dBi while for the nested square DR gain remained almost the same as that of the homogeneous square DR. With reference to these findings it was found that performance of the DRA can be noticeably improved with systematic introduction of inhomogeneity in the DR

    Willingness to communicate in relation to language use among Pakistani undergraduates: A sociocultural perspective

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    This study aimed to investigate English as a second language (ESL) undergraduates’ sociocultural perspective of willingness to communicate (WTC) in English inside the classroom in relation to language use outside the classroom. The participants were 440 ESL undergraduates selected through the cluster sampling method from eight universities in Khyber Pakhtunkhwa Province in Pakistan. The data were collected through questionnaires on WTC in English inside the classroom and language use outside the classroom. The findings revealed that the participants’ level of WTC in English was high for most social interactions within the classroom, such as in groups, during activities, with the same gender, and when given preparation time in groups. The findings for language use showed that a mixture of languages, such as Pashto and Urdu, was predominantly used in the family, neighbourhood and friendship, religion, education, and transaction domains. In contrast, English was primarily used in the mass media and social media domains. Moreover, the findings revealed that WTC in English inside the classroom was positively correlated with social media, mass media, transaction and education domains but negatively correlated with the family domain

    Open Access Repositories in Asia: An Overview

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    Open access refers to the free and unrestricted access to scholarly literature published around the globe via internet. Online free access to quality literature is desired by every individual, organization or community especially in developing nations. Various studies have been conducted which show that the growth of open access in developed regions like Europe and North America is quite prevalent but in case of developing nations such is not the case. Though developing regions are making progress towards liberating the literature from chains but still there is long way to go. Open access needs to be promoted on a large scale in developing nations. One among the various factors which necessitate the promotion of open access in developing countries is the economic constraint. Many organizations or individual scholars are not able to access and use the quality literature because they are not able to bear the expenses involved in the process and because access to literature is usually subscription based thus is required to be renewed every year. The present study analyzes the development of open access repositories in Asia. Their growth, country wise contribution, software used in creation of open access repositories etc. The study will analyze how much progress is made by the developing nations in Asia in the year 2019 by comparing it to the results of earlier studies conducted

    Web 2.0 & Public Health

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    Abstract Purpose: The purpose of the study is to know the awareness, usage, and impact of web 2.0 tools on the health of general public. Design/methodology/approach: Questioners were prepared and distributed among the departments under applied sciences of the University of Kashmir. Simple random sampling technique was employed. Findings: Although people are well aware of the term Web and Web 2.0 tools but least are these tools used for health purposes like self-diagnosis, self-medication, online doctor consultation etc. The study also reveals that usage of Web 2.0 tools helps in reducing the mental stress in common public. Practical implications: Health of general public can be improved by making them aware & showing them how to use web 2.0 tools for health purposes, we can make them familiar with online doctor consultation, buying medicine online at cheap costs, sharing of health details on web assuring them confidentiality of their health details. Originality/value: The study investigates the awareness, usage & impact of web 2.0 tools on the health of general public. Such study has not been conducted before in the vicinity of University of Kashmir, India. Keywords: Web 2.0, Online doctor consultation, Facebook, Twitter, Netmeds, PatientslikeMe.com. Paper Type: Research pape

    Effective tool for exploring web: An Evaluation of Search engines

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    Evaluation of search engines is necessary to check the retrieval performance of search engines and to differentiate search engines from one another. The ability to retrieve and to rank the relevant result lists can be done by the process of evaluation and this process can take place in two ways viz; human based methods where one can evaluate search engines manually to calculate the significance of the returned results but this method is time consuming and expensive, while as the second is automatic method where one can make use of various techniques like retrieval measures can be used to assess the performance of search engines

    Finite Difference Method with Dirichlet Problems of 2D Laplace’s Equation in Elliptic Domain

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    In this study finite difference method (FDM) is used with Dirichlet boundary conditions on rectangular domain to solve the 2D Laplace equation. The chosen body is elliptical, which is discretized into square grids. The finite difference method is applied for numerical differentiation of the observed example of rectangular domain with Dirichlet boundary conditions. The obtained numerical results arecompared with analytical solution. The obtained results show the efficiency of the FDM and settled with the obtained exact solution. The study objective is to check the accuracy of FDM for the numerical solutions of elliptical bodies of 2D Laplace equations. The study contributes to find the heat (temperature) distribution inside a regular rectangular elliptical discretized body

    Broadband Dual-Segment Rectangular Dielectric Resonator Antenna For 5.8 Ghz Applications

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    Antena Penyalun Dielektrik (APD) jalur lebar adalah satu antenna yang boleh memancar dan menerima signal elektromagnetik dalam julat frekuensi yang lebar untuk telekomunikasi berkapasiti tinggi. Bahan-bahan dielektrik dengan ketelusan dan faktor kualiti yang rendah boleh menyimpan kurang tenaga elektromagnetik dan seterusnya mengalami gandingan lemah daripada sumber teruja. Sebaliknya bahan-bahan dengan ketelusan tinggi mempunyai fakfor kualiti dan medan elektrik dan magnetik tinggi boleh terhasil dalam penyalun, seterusnya boleh beroperasi dalam lebar jalur sempit dengan gandingan yang kuat. Untuk APD yang mempunyai gandingan elektromagnetik kuat dimana boleh beroperasi dalam julat frekuensi yang lebar, dua bahan ketelusan yang berbeza digunakan untuk merekabentuk antenna. Bahan dielektrik berbentuk segiempat tepat digunakan untuk kedua-dua segmen APD kerana mod kemerosotan boleh dikawal dengan memilih nisbah aspek yang sesuai dalam penyalun. Untuk segmen atas penyalun lapis dielektrik gelombang mikro Roger RT 6010 dari Roger Cooperation digunakan sebagai penyalun utama. Untuk segmen bawah yang bertindak sebagai pengubah galangan, diantara segmen atas dan talian suapan, dua bahan dielektrik yang berbeza iaitu Barium Zinc Tantalum (BZT) dan Calcium Copper Titanate (CCTO) dibina. Untuk antena unsur tunggal dan antena dua unsur teratur BZT digunakan sebagai pengubah manakala untuk empat unsur dan lapan unsur antena teratur CCTO digunakan bagi mengawal gandingan sepunya diantara penyalun terdekat

    Perception Regarding the Effects of Sense of Insecurity on Sports Events in Pakistan

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    Security is very important in all sort of life especially in sports. For the last years, so many events of hockey and cricket cancelled or postponed due to security reasons in Pakistan. The current study aims to find out the “perception regarding the effects of sense of insecurity on sports events in Pakistan”. The study sample included cricket and hockey officials, players, and sports media representatives. To achieve objective of the study, three questionnaires on five point rating scale were developed for the selected sample. The data were analyzed and the result was converted into percentage and meanscore. The study's primary results were that 80% of officials believed that a sense of fear was the cause for the cancellation of sporting events in the country. Whereas 86% players agreed that sense of insecurity is the reason for the cancellation of sports events in the country. It was also found that 68% of both the officials and players disagreed that enough funds were allocated for the provision of security during sports. It was further found that 60% media persons agreed that strict checking was often overlooked during entry in thestadium.On the basis of finding it was concluded that most of the officials and players think that relevant information regarding security is not provided to them. It is also concluded that the officials and players were agreed while media persons disagree that security personnel are fully equipped with skills. Another conclusion is that the officials and players opinion that enough safety facilities provided to them while media persons and spectators do not agree with this. Keeping in view the findings and conclusions, it is recommended that security information may be provided to officials and players before the start of the competitionand specific measures relating to strict security arrangement and skilled professional staff may be made during the sports events. It is further recommended that more safety facilities may be provided to officials, players and media persons in national games. Key words: Perception, sense of insecurity, sports event

    LOCKSS, CLOCKSS & PORTICO: A LOOK INTO DIGITAL PRESERVATION POLICIES

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    Digital preservation is the process of preserving information in the digital form. By digital form we mean a non- print form. Information is moving from print to web (non-print) and it has become easy for masses especially the scholarly population to access information on the web from anywhere 24*7. Since digital information is more prone to damage and loss than print information, therefore, it is imperative to protect access to this information not only for the benefit of present but for future generation as well. Various initiatives and policies are currently in place to ensure the long term preservation of digital information. LOCKSS, CLOCKSS, and PORTICO are the three major digital preservation initiatives aimed at protecting and preserving the digital content for its long term access and use. The current study provides an overview of how these three initiatives started and how these policies function in collaboration with publishers and libraries for long term digital content preservation

    POWER RELATED COMPONENTS OF PHYSICAL FITNESS: A COMPARATIVE STUDY OF GOVERNMENT AND PRIVATE SCHOOLS

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    The physical fitness trainings, accordingly, have been split into specificaspects in order to attain endurance, coordination, flexibility, speed andstrength. Literature review clearly reveals that there is lack of data regardingphysical fitness levels in private and government school going children fromPakistan. The present study was conducted with an aim to compare the powerrelated components (Standing broad jump, Push Ups, Sit Ups, and Hand Grip)of physical fitness of government and private schools’ children. Crosssectional study design was used, the study was conducted on male children(n=304, 152 each from private and government schools) locatedwithin/outskirts of the main city of Sargodha, Pakistan. Total ten schools (5private and 5 government) were earmarked and registered in the study.Convenience sampling technique was used. Children between the ages of 9-11years, Children in primary level of education and children which are theresidents of Sargodha were included in the study. There were statisticallysignificant differences between Standing broad jump, Push Ups, Sit Ups, HandGrip of Private and Government schools’ students. Finally, it was concludedthat the power-related components of physical fitness of government schoolchildren is better than the private schools’ children except hand grip tes
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