Design and analysis of social network systems (SNS)

In the last few years, online Social Network Systems (SNSs) thrived and changed the overall outlook of the Internet. These systems play an important role in making the Internet social, a hallmark of Web 2.0. Various such systems have been developed to serve a diverse set of needs. SNSs provide not only a space for self-representation, but also mechanisms to build and maintain one’s social network online. A lot of studies have been carried out on such systems to identify how people develop cultures of communication, sharing and participation and also to identify the network structure of such systems. In this thesis, we carry this line of research forward. Our aim is the identification of some key user characteristics and social processes which result in the emergence of a social network. These might help future platform and application developers in creating better, more efficient and more open and user-friendly SNSs. Specifically, we make the following three major contributions: a) One of the distinct features of an SNS is the public listing of friendship links - social network. Most of the personal details such as hometown and workplace information have been hidden from non-friends, but the list of friendships remains open. Being a true representation, people use their real names as their screen names. Such names alone contain detailed cultural information about their ethnicities, religion and even their geographical origins. Our first contribution is that we have made good use of such information by inferring ethnic classification of users of Facebook. We identified how clustered and segregated the overall social network is when users’ inferred ethnicity is taken into account. Different cultures have different behaviours with distinct characteristics. This rich information can be used to develop an understanding and help create diverse applications catering for specific ethnicities and geographical regions; covering both the dominant and non-dominant groups. We have identified ethnicities of a subset of Facebook users with their friends and studied how different ethnicities are connected among and within each other. A large social network dataset of four thousand Manchester Metropolitan University (MMU) students have been selected from Facebook. We have extensively analysed this dataset for its network structure and also its semantic and social structure. Our work suggests our dataset is clustered and segregated on ethnic lines. b) To develop a user liberating SNS where the control and the ownership of rich personal data is in the hands of SNS users, a clear understanding is required of how such systems on an individual and group level are developed and maintained. Never before in Social Sciences was it possible to study society on such a large scale. These systems have facilitated the study of individuals both at a local and global scale. However, at the moment very little knowledge is available to identify how people develop their friendship in reality. So for example, it is not known whether in SNSs people meet others based on their attributes and interests, or if they simply bring online their real lives’ social networks. And more specifically, what processes does one go through to develop her social network. To fill this knowledge gap in this thesis, as our second contribution, we have used a computer simulation technique known as Agent-Based simulation, to develop four simulation models based on both individuals’ affinities and environmental aspects. Specifically, we have developed models of student interaction to develop social networks. Three University’s datasets which include Caltech (Nodes 762, Edges 16651), Princeton (Nodes 6575, Edges 293307) and Georgetown (Nodes 9388, Edges 425619), have been used to check the performance and rigour of the model. Our evidence suggests that ‘friend-of-a-friend’ (FOAF) best represents social interactions in Caltech University. In the case of Princeton and Georgetown, we found a multitude of social and structural processes involved, which are: attribute based (same dormitory, major or high school etc.), social interaction, random meet ups (through parties or other social events) and current friends introducing new friends. c) We observe that in the main, SNSs are centralised, and depend solely on central entities for everything. With huge personal data on such SNSs, advertising and marketing agencies have made very sophisticated systems to gather information about people. It is a goldmine for them for personalised advertisement. Also various governmental agencies have been using SNSs as an excuse to curb potential threats both legally and illegally, to obtain information on numerous users (people). In order to deal with such issues inherent in centralised client-server architecture, as the third contribution of this thesis, we have proposed and implemented a completely decentralised SNS in a peer-to-peer fashion. Our implementation is done in an open source Peer-To-Peer (P2P) client Tribler. To handle the dynamicity of users in a P2P system – their availability, we have developed mechanisms to deal with it. This SNS has been evaluated on a deployed system with real users. This prototype establishes the feasibility of a totally distributed SNS, but its practicality when scaled to a full system would require more work

Posterior Mediastinal Chondrosarcoma- A rare entity

Introduction:Chondrosarcoma is a well defined tumor of soft tissue with calcification. Extraskeletal myxoid chondrosarcoma is an unusual sarcoma of soft tissue adding only 3% to all soft tissue tumors. Majority of mediastinal foci originates from variety of tissues, the reason being their diverse embryological and anatomical approximations. Chondrosarcomas are more common in males with 2:1 male to female ratio. The exact pathology of these tumors is unclear; however recent data ensures that these tumors have multidirectional delineation. Classical histopathological features of chondrosarcoma include S-100 positivity, EMA positivity. These features of Immunohistochemical favor extra skeletal myxoid chondrosarcoma.Case Report:Recent data signifies that the tumor is known for its rare occurrence, here we have reported a unique case of 40 years old male visited Abbasi Shaheed Hospital for pre employment checkup without any symptoms. All the tests were negative except Chest X-ray PA view which revealed dense mass on lower lobe of lung. For further evaluation, CT scan of chest with contrast was ordered and eventually the mass was resected surgically. On the basis of macro and microscopic findings, histopathological tests and immunohistochemical stains, the mass was found to be chondrosarcoma with myxoid origin. This tumor has to be distinguishing among the list of different diseases like hamartoma, hydatid cyst, and neuroendocrine tumors for the differential diagnosis of the case.Conclusion: Our paper reports an extraskeletal mesenchymal chondrosarcoma originating in the posterior mediastinum with a rare presentation.Â

An unusual combination of extra-adrenal pheochromocytoma and arteriovenous malformation of the ureter in a young adult

We present a case of a 24-year-old gentleman who presented with painless pan haematuria for 2 weeks. During the workup, he was diagnosed to have a retrocaval mass after a CT scan while cystoscopy revealed a polypoidal pulsating lesion in the left ureter. After surgical manipulation of the retrocaval mass, the blood pressure of the patient raised to 260/130 mm Hg. It was completely resected and diagnosed as extra-adrenalpheochromocytoma (paraganglioma) after histopathology. The lesion in the ureter was completely excised and fulgurated and diagnosed as anarteriovenous malformation. To the best of our knowledge, this is the first patient to be presented in the literature with this unusual combination

FREQUENCY OF HCV INFECTION AND ITS GENOTYPES AMONG PATIENTS ATTENDING A LIVER CLINIC AND VOLUNTARY BLOOD DONORS IN A RURAL AREA OF PAKISTAN

ABSTRACT Objectives: To determine the frequency of Hepatitis C virus (HCV) infection and its genotypic distribution in a rural area of Sindh, Pakistan. Methodology: Retrospective study of patients attending the Free Liver Clinic (FLC), and investigated for detectable HCV antibodies (n=1638), and those screened for HCV infection prior to voluntary blood donation (n=804) at a teaching hospital, located in rural Sindh. All patients had HCV antibodies tested by ELISA. A total of 1022 patients, who tested 'reactive' to HCV antibodies, and who could financially afford to have HCV RNA tested by PCR, had their results analysed. A total of 200 patients also had their HCV genotyped and analysed. Results: Patients at FLC had a higher chance of being reactive for HCV antibodies, compared to voluntary blood donors (20% VS 14% -p = 0.004). HCV RNA was detectable in 904/1022 (88%) patients. Among typeable genotypes, 125/166 (75%) had a single genotype, and 7 patients (4%) were infected with genotype 1, either alone (n=4) or in combination with 3a. Conclusions: One out of every five people tested in our FLC, and 14% of "healthy" voluntary blood donors were seropositive for HCV antibodies. Genotype 1 is very rare in our region

How to Retain the ‘Core- Employees’ Through HR Practices? An Empirical Study of Public & Private Sector Universities of Khyber Pakhtunkhwa (KP), Pakistan

This study investigates the influence and effectiveness of Human Resource Management Practices which will help organization to sustain the “core-employees”.  Employee retention is one of the challenges facing many business organizations today. This empirical study examined the current Human Resource Management practices in Higher education institution of Khyber Pakhtunkhwa. In particular, the study identifies those elements of HRM, which strongly influence the “Core-employees” to stay in the organization, because organizations inclination now days depend on upon knowledge base human capital and due to the emergence of new Public & Private sector universities in Khyber Pakhtunkhwa, most of the universities are facing employees turnover. In this study employee of both Public & Private sector universities of Khyber Pakhtunkhwa is targeted, in order to extract information regarding HRM practices that which factor significantly influence these core employees to stay in the organization. For this study One hundred and thirty participants were selected from thirteen Public and Private sectors universities of Khyber Pakhtunkhwa. Through stratified random sampling method. The constructs of the study were measured using five-point Likert rating scale. Keywords: Employees Retention, HRM Practices, Core employees, Reward and Recognition, Compensation

RELATIONSHIP BETWEEN METROLOGICAL PARAMETERS AND VECTOR BORNE DENGUE DISEASE USING ONCOLOGICAL FRACTAL TREATMENT

Dengue is the most vital arboviral disease in humans, which is occurring in tropical and subtropical areas around the world. Dengue fever is itemized as an urban human disease as it spreads easily to urban environmental/ morphological contexts because of the uneven increase of urban population and infectious diseases as a result of climate change. Dengue epidemic cases related to climatic parameters are helpful to monitor and prevent the transmission of dengue fever. Many studies have focused on describing the clinical aspects of dengue outbreak. We bring out the epidemiological study to investigate the dengue fever development and prediction in the Karachi city. This study described the oncological treatment by statistical analysis and fractal rescaled range (R/S) method of the dengue epidemics from January 2001 to December 2020, based on the urban morphological patterns, and climatic variables including temperature and ENSO respectively. The R/S method in oncologists has been carried in two ways, basic oncological/statistical analysis and Fractal dimension adapt to the study the nature of the subtleties of dengue epidemic data, another showing the dynamics of oncological process. Climate parameters are shown that the fractal dimension value revealed a persistency behavior i.e. time series is an increasing, Fractal analysis also confirmed the anti-persistent behavior of dengue for months of September to November and the normality tests specified the robust indication of the intricacy of data. This study will be useful for future researchers working on epidemiology and urban environmental oncological fields to improve and rectify the urban infectious diseases

Evaluation of thermodynamics, formation energetics and electronic properties of vacancy defects in CaZrO3

Using first-principles total energy calculations we have evaluated the thermodynamics and the electronic properties of intrinsic vacancy defects in orthorhombic CaZrO3. Charge density calculations and the atoms-in-molecules concept are used to elucidate the changes in electronic properties of CaZrO3 upon the introduction of vacancy defects. We explore the chemical stability and defect formation energies of charge-neutral as well as of charged intrinsic vacancies under various synthesis conditions and also present full and partial Schottky reaction energies. The calculated electronic properties indicate that hole-doped state can be achieved in charge neutral Ca vacancy containing CaZrO3 under oxidation condition, while reduction condition allows to control the electrical conductivity of CaZrO3 depending on the charge state and concentration of oxygen vacancies. The clustering of neutral oxygen vacancies in CaZrO3 is examined as well. This provides useful information for tailoring the electronic properties of this material. We show that intentional incorporation of various forms of intrinsic vacancy defects in CaZrO3 allows to considerably modify its electronic properties, making this material suitable for a wide range of applications

Design and Simulation of Cascaded Class-A Microwave Power Amplifier

Microwave power amplifiers are the most significant components in wireless communications systems. As the technology continue to progress, the designers are facing new challenges and opportunities. The purpose of this work is to push the limits of efficiency and bandwidth of power amplifiers. The objective of this research is to design and build a prototype two stage Microwave power amplifier operated at 2.4 GHz with a linear region of operation up to our desired output of 0.5 watt or 27 dBm. The transistor used in the first stage is BFP540 while the output power of the first stage is the input of the second stage in which the ATF50189 transistor is used to for amplification. All the simulations and readings are taken by using AWR Microwave Office software. By using the load line Rl and the biasing points are achieved for both stages. The applications of our proposed device include many products in the field of microwave communications. One of the important applications of a Microwave power amplifier is in the output stage of a transmitter where a signal needs amplification before it is transmitted.DOI:http://dx.doi.org/10.11591/ijece.v3i5.364

Families of Women Entrepreneurs in Pakistan Their Paramount Support or Dreadful Obstacle

Purpose: This research aims to identify some female entrepreneurs and their relationship profiles with their families, which are categorized by families having a prominent part in influencing their decisions, activities, and behavior. Methodology: The qualitative technique was used as it is well suited to examining the experiences of different people. Open-ended Interviews with Pakistani female entrepreneurs using a semi-structured questionnaire were used to obtain data. The research allowed us to focus on one of the most pressing concerns affecting female entrepreneurs: integrating life with family, work, and their goals related to their profession. Findings: Evidently, knowing and understanding the importance of the household in the entrepreneurial experiences of women is critical to deciphering the reasons why enterprises that are owned by women thrive or crash, as family relations will invariably influence their performance. Conclusion: The research revealed that female entrepreneurs and their families have a significant linkage with their entrepreneurial experiences i.e., individual decisions of women to become entrepreneurs and the features of their businesses cannot be fully comprehended unless the family dimension is also considered

An empirical study on individual performance and turnover intention among university employees: a multiple mediation model

Purpose: The purpose of this study is to investigate the behavior of individual employee's performance concerning their organizational citizenship and turnover intention in the higher education sector. This study attempts to examine the effects of two potential sequential mediators – job satisfaction and employee engagement – on employees' job embeddedness, organizational citizenship behavior, and turnover intention. Design/methodology/approach: This study is based on a survey conducted among the employees of major universities in the Republic of Korea. A total of 213 valid responses are used to analyze the hypotheses. Findings: The results suggest that the relationship between job embeddedness and organizational citizenship behavior is significantly mediated by job satisfaction. However, the mediating role of job satisfaction on the link between job embeddedness and employees' intention to leave is not significant. Relatedly, employee engagement has a significant mediating effect on job embeddedness and organizational citizenship behavior but no demonstrable mediating effect between job embeddedness and employees' turnover intentions. Practical implications: The results provide guidance that can assist organizations in increasing their employees' organizational citizenship behavior and lowering their intentions to leave, particularly in the education sector. Originality/value: This study contributes to existing knowledge regarding the roles that job satisfaction and employee engagement play as two potential sequential mediators in the relation between job embeddedness and organizational citizenship behavior