Uplink Secure Communication via Intelligent Reflecting Surface and Energy-Harvesting Jammer

In this paper, we investigate the uplink secure communication by combining intelligent reflecting surface (IRS) and energy-harvesting (EH) jammer. Specifically, we propose an IRS-aided secure scheme for the uplink transmission via an EH jammer, to fight against the malicious eavesdropper. An energy transfer (ET) phase and an information transmission (IT) phase are proposed in this scheme. In the ET phase, we optimize the phase-shift matrix of IRS to maximize the harvested energy of jammer. In the IT phase, the phase-shift matrix of IRS and time switching factor are jointly optimized to maximize the secrecy rate. To tackle the non-convex problem, we first decompose it into two subproblems to solve by capitalizing on semi-definite relaxation (SDR) and Lagrange duality. Then, the solutions to the original problem can be obtained by alternately optimizing the two subproblems. Simulation results show that the proposed Jammer-IRS assisted secure transmission scheme can significantly enhance the uplink security

A simulation study of the passenger check-in system at the Ottawa international airport

This work presents a simulation study of the check-in system at the Ottawa International Airport. Various data were collected and used to define the inputs to a simulation model. These include the current agents' working schedules, the passengers' arrival pattern distributions, the passengers' service time distributions, the historical flight load factor, the distributions of the types of passengers, and the flight schedule. The scenarios evaluated include changing the queue structure and considering alternate agents' working schedules. The performance measurement retained are the average waiting time in queues, the maximum waiting time in queues, the average queue length, the maximum queue length, and the distribution of passengers waiting times in queues. A linear programming (LP) model was developed to provide alternate agent working schedules that minimizes the total agent person hours and meets the passenger loads that vary throughout the day. A heuristic was used to incorporate breaks and lunches. The critical factor that impacts the check-in service performance proved to be the agents' working schedule. Sensitivity analysis on changes of passenger loads and service rates were performed and the findings are discussed

An occupational therapy approach to the support of a young immigrant female's mental health: A story of bicultural personal growth

Young immigrants who suffer from psychosis perceive their illness from the outlook of at least two cultures, which is often a source of confusion and misunderstanding for clients, their families, and clinicians. This article presents a case study with a narrative approach, aiming to illustrate how an occupational therapy intervention can highlight the role of culture and address bicultural identification in a young adult immigrant woman with mental health problems. The results show how a culturally adapted intervention model can be used to help the client go through a transition from an interdependent to a more independent self. During the course of occupational therapy, the client gained greater insight into her problems and could view herself as integrating numerous facets related to two different social and cultural contexts. Moreover, the client achieved better skills in dealing with discrepancies and cultural contradictions and became capable of relying on either or both of the cultures in different situations