Wireless Scheduling with Power Control

We consider the scheduling of arbitrary wireless links in the physical model of interference to minimize the time for satisfying all requests. We study here the combined problem of scheduling and power control, where we seek both an assignment of power settings and a partition of the links so that each set satisfies the signal-to-interference-plus-noise (SINR) constraints. We give an algorithm that attains an approximation ratio of $O(\log n \cdot \log\log \Delta)$, where $n$ is the number of links and $\Delta$ is the ratio between the longest and the shortest link length. Under the natural assumption that lengths are represented in binary, this gives the first approximation ratio that is polylogarithmic in the size of the input. The algorithm has the desirable property of using an oblivious power assignment, where the power assigned to a sender depends only on the length of the link. We give evidence that this dependence on $\Delta$ is unavoidable, showing that any reasonably-behaving oblivious power assignment results in a $\Omega(\log\log \Delta)$-approximation. These results hold also for the (weighted) capacity problem of finding a maximum (weighted) subset of links that can be scheduled in a single time slot. In addition, we obtain improved approximation for a bidirectional variant of the scheduling problem, give partial answers to questions about the utility of graphs for modeling physical interference, and generalize the setting from the standard 2-dimensional Euclidean plane to doubling metrics. Finally, we explore the utility of graph models in capturing wireless interference.Comment: Revised full versio

Exploring women’s perspectives of living with mental illness, stigma, and receiving community services

According to the Canadian Mental Health Association (CMHA) (2015), one in five individuals will experience mental illness personally, which means that all Canadians will be indirectly (or directly) influenced by mental illness at some point in their life. Unfortunately, due to historical trends and negative stereotypes mental illness has become heavily stigmatized (Camp, Finlay, and Lyons, 2002; Chernomas, Clarke, and Chisholm, 2000; Link, Struening, Neese-Todd, Asmussen, and Phelan, 2001; Sands, 2009; Szeto, Luong & Dobson, 2013). Although many studies have assessed the relationship between mental illness and stigma, little research has included a gender lens when exploring these topics. Therefore, the primary research objective of the current study is to explore women’s perspectives of living with mental illness, stigma, and receiving community services. In total, five women from the Kitchener, Waterloo, and Cambridge area participated in the study. Similar to the literature, results found that the women experienced feelings of loneliness and sadness due to their mental illness diagnosis and the stigma they experienced from friends, family, and service staff. Some women talked about being relieved to have a label or diagnosis for their illness, however, the majority of their narratives suggested that living with a mental illness is difficult due to the internal and external stigma they experience. Findings from this study have implications for contributing to the field of social work, improving service delivery within various healthcare facilities, and future research