On Modeling Heterogeneous Wireless Networks Using Non-Poisson Point Processes

Future wireless networks are required to support 1000 times higher data rate, than the current LTE standard. In order to meet the ever increasing demand, it is inevitable that, future wireless networks will have to develop seamless interconnection between multiple technologies. A manifestation of this idea is the collaboration among different types of network tiers such as macro and small cells, leading to the so-called heterogeneous networks (HetNets). Researchers have used stochastic geometry to analyze such networks and understand their real potential. Unsurprisingly, it has been revealed that interference has a detrimental effect on performance, especially if not modeled properly. Interference can be correlated in space and/or time, which has been overlooked in the past. For instance, it is normally assumed that the nodes are located completely independent of each other and follow a homogeneous Poisson point process (PPP), which is not necessarily true in real networks since the node locations are spatially dependent. In addition, the interference correlation created by correlated stochastic processes has mostly been ignored. To this end, we take a different approach in modeling the interference where we use non-PPP, as well as we study the impact of spatial and temporal correlation on the performance of HetNets. To illustrate the impact of correlation on performance, we consider three case studies from real-life scenarios. Specifically, we use massive multiple-input multiple-output (MIMO) to understand the impact of spatial correlation; we use the random medium access protocol to examine the temporal correlation; and we use cooperative relay networks to illustrate the spatial-temporal correlation. We present several numerical examples through which we demonstrate the impact of various correlation types on the performance of HetNets.Comment: Submitted to IEEE Communications Magazin

A Stochastic Geometric Analysis of Device-to-Device Communications Operating over Generalized Fading Channels

Device-to-device (D2D) communications are now considered as an integral part of future 5G networks which will enable direct communication between user equipment (UE) without unnecessary routing via the network infrastructure. This architecture will result in higher throughputs than conventional cellular networks, but with the increased potential for co-channel interference induced by randomly located cellular and D2D UEs. The physical channels which constitute D2D communications can be expected to be complex in nature, experiencing both line-of-sight (LOS) and non-LOS (NLOS) conditions across closely located D2D pairs. As well as this, given the diverse range of operating environments, they may also be subject to clustering of the scattered multipath contribution, i.e., propagation characteristics which are quite dissimilar to conventional Rayeligh fading environments. To address these challenges, we consider two recently proposed generalized fading models, namely $\kappa-\mu$ and $\eta-\mu$, to characterize the fading behavior in D2D communications. Together, these models encompass many of the most widely encountered and utilized fading models in the literature such as Rayleigh, Rice (Nakagami-$n$), Nakagami-$m$, Hoyt (Nakagami-$q$) and One-Sided Gaussian. Using stochastic geometry we evaluate the rate and bit error probability of D2D networks under generalized fading conditions. Based on the analytical results, we present new insights into the trade-offs between the reliability, rate, and mode selection under realistic operating conditions. Our results suggest that D2D mode achieves higher rates over cellular link at the expense of a higher bit error probability. Through numerical evaluations, we also investigate the performance gains of D2D networks and demonstrate their superiority over traditional cellular networks.Comment: Submitted to IEEE Transactions on Wireless Communication

Workplace Violence Against Staff Working in the Emergency Department in West Bank, Palestine

Workplace violence against staff in emergency departments (EDs) has reached catastrophic proportions, and has become an endemic problem affecting nurses in all settings. The aims of this study were to investigate the prevalence of violence experienced by Palestinian staff in EDs, the types of violence, its sources, and factors affecting violence experiences, and reporting the incidence. This descriptive cross-sectional study was conducted between Jan and May 2016 in the emergency department of four hospitals in West Bank, Palestine. Data were collected from 91 staff working in various emergency settings. The instrument was a 42-item questionnaire on types of violence, its sources, feelings, and ways to cope with violent behaviors. Descriptive statistics and chisquare tests were used for data analysis. The results showed 74.7% of participants had been exposed to at least one kind of violence: 26.4% to physical assault, 60.4% to verbal abuse, and 13.2% to both (physical and verbal). Patients’ family (79.4%) was identified as the primary perpetrators of violence. The most common coping method among participants (61.2%) for violence was to report to a manager. Based on results of the study, Workplace violence against nurses is a significant problem in Palestine. The impatience that accompanies waiting times may have a cultural element. Lessening waiting times and providing more information to patients and families could reduce the rate of violence, Policy and decision-makers are urged to use study findings for policy and practice interventions to create safe work environments conducive to nurses’ productivity and retention.The author thanks all the nurses who provided the information necessary for completion of the study. He also acknowledges the fourth year nursing students for data collection and data entry

Consanguineous Marriage and Its Effect on Offspring Congenital Malformation: A Study among Palestinian Rural Community

Objective: Consanguineous marriage is a long-standing socially accepted practice among Palestinian population. It is proposed that consanguineous marriages increase the risk of congenital malformations and genetic disorders. This study aimed to determine the health consequences of consanguinity on congenital malformations in Yata rural population, Hebron, Palestine. Methods: A cross-sectional household-survey study was conducted on 500 married women. All the women were interviewed personally using a structured questionnaire. A family pedigree was constructed to study the type of consanguineous marriages. Results: The prevalence rate of consanguineous marriages in the present study was 61%, where first-cousin marriages representing 34.8% of all marriages. The genitourinary system was the most common malformation, where was reported by 17.4% of the 305 consanguineous married parents, and 15.2% of the 105 non-consanguineous married parents. The gastrointestinal system defects was the second most affected anatomical system in frequency in 6.2% of the 305 consanguineous married parents, and 13.3% of the 105 non-consanguineous married parents. Conclusion: The study revealed that consanguinity has adverse health consequences on offspring of consanguineous couples. There is a need for genetic counseling to increase the awareness of the health consequences of consanguineous marriages.The authors of this paper would like to thank the School of Public Health, Al Quds University in Palestine. As well as, the authors would like to thank both the all participants of this study, the field workers, the Municipality of Yatta, and the higher education ethical committee of Al Quds University

Bi-Objective Optimization for a Single Batch Processing Machine

This research proposes a methodology for solving the problem of scheduling jobs with unequal ready times, unequal processing times, and unequal sizes on a single batch processing machine, with the objectives of minimizing makespan and maximum tardiness. Jobs must be placed into batches and scheduled on the machine such that both objectives are minimized, and machine capacity is not violated. The problem under study can be denoted as 1|p-batch, sj, rj| Cmax,Tmax. Based on a review of relevant literature, this problem has not been considered before. The problem under study is NP-hard. Consequently, meta-heuristics such as Simulated Annealing (SA) and a Greedy Randomized Adaptive Search Procedure (GRASP) are proposed. A mathematical formulation for the problem is also proposed. Since the problem is NP-hard, the commercial solver used to solve the mathematical model is not effective to solve larger problem instances. An experimental study is conducted to evaluate SA and GRASP in terms of the quality of solution and run time required to solve randomly generated problem instances. The experimental study compares the meta-heuristics to the commercial solver used to solve the mathematical formulation. A set of 225 instances is generated by varying values of job sizes, processing times, ready times, and due dates. The problem is formulated as a minimization of the weighted sum of the objectives (αCmax + βTmax), where α = [0, 0.25, 0.5, 0.75, 1] and β = 1 – α. SA and GRASP are developed in Matlab R2015a, and all instances are solved for all values of α. Additionally, the mathematical formulation is solved using IBM ILOG CPLEX software for values of α. To determine the quality of the meta-heuristics, the solutions obtained from SA and GRASP are compared to those obtained from CPLEX. Additionally, the Mean Ideal Distance (MID), Diversity Matrix (DM), Spread of Non-Dominance Solutions (SNS) and the number of non-dominated solutions are calculated for each meta-heuristic, and used to compare them. Based on the results, both GRASP and SA outperform CPLEX for 150 job instances, with SA outperforming CPLEX for 100 job instances as well. GRASP provides a larger number of non-dominated solutions, but SA provides higher quality solutions. Overall, SA provides a larger proportion of solutions that are the same as or better than CPLEX. Both SA and GRASP have significantly shorter computational times than CPLEX. The findings of this research directly benefit schedulers working for contract electronics manufacturers, who are faced with the ardent task of scheduling hundreds of jobs each day on their batch processing machine. The meta-heuristics proposed in the research give alternative solution approaches for practitioners and academics to explore further to solve the problem under study and extensions of it

Knowledge of Palestinian University Women Employees About Heart Disease: Across-Sectional Study

Heart disease is the first leading cause of death and disability for women worldwide, yet the condition is largely preventable and few women perceive themselves at risk. Evidence in the literature supports diminished awareness of heart disease among women and limited data as to provider knowledge of the current guidelines for the prevention of heart disease in women. The purpose of this study was to examine the current knowledge levels, personal risk factors related to heart disease among selected university female employees, and to identify variables that best predict health-promoting behaviors among university female employees. A descriptive crosssectional research design was utilized. A stratified sample of 320 Palestinian university females aged 20-58 years completed a questionnaire developed by the researcher to assess their knowledge of heart disease and to assess the heart disease risk factors. Descriptive and inferential statistics were used for data analysis. Results: The sample had an average knowledge score of 45.9% out of a maximum correct score of 100%. Results from data analysis revealed general knowledge of heart disease was relatively low. The risk factors prevalent among them included: hypertension (14.6%), diabetes (11.8%), dyslipidemia (11.1%), overweight (21.8%), smoking (19.6%), and physically inactive (55.4%). Conclusion: Heart disease is the leading cause of death among Palestinians. In this study, Palestinian university women had poor knowledge of heart disease, and many reported having risk factors. Evaluation of baseline knowledge of heart disease and specific risk factors is helpful and can guide tailoring of health prevention strategies to be more effective. Early screening targeting the younger generation is also important to help detect the risk factors in their earliest stages. The screening results may also induce individuals to take action.The authors of this paper would like to thank the Faculty of Health Professions and the Department of Nursing, Al Quds University. As well as, the author is grateful to the study participants

EVS Throughput Improvement

This paper covers the background, methods, and results of the Environmental Services (EVS) Throughput Improvement project at Northwestern Medicine’s Kishwaukee Hospital. Patient throughput at hospitals is closely related to the experience of its patients. At Kishwaukee hospital, increased demand for inpatient services resulted in high occupancy rates and thereby undesirable patient throughput patterns. The project addresses patient throughput related problems at the hospital by seeking to improve the EVS bed turnaround process. This process is defined as the time from when the EVS system is notified that a bed is ready for turnaround, to the time that the room is prepared for the next patient. The primary objective of the project is to reduce the cycle time of the process. The project considers improvements to the scheduling, communication, and standardization of this process by delivering data supported process improvements, industry best practices, and tools for improved communication and feedback. The project succeeds in sustainably reducing the cycle time for the bed turnaround process. Additionally, the project analyzes the effects of factors related to patient throughput using an ARENA discrete event simulation model. The factors analyzed are the bed turnaround time, the patient discharge time, and the number of hospital beds