CrowdLoc

Determining the location of a mobile user is central to several crowd-sensing applications. Using a Global Positioning System is not only power-hungry, but also unavailable in many locations. While there has been work on cellular-based localization, we consider an unexplored opportunity to improve location accuracy by combining cellular information across multiple mobile devices located near each other. For instance, this opportunity may arise in the context of public transport units having multiple travelers. Based on theoretical analysis and an extensive experimental study on several public transportation routes in two cities, we show that combining cellular information across nearby phones considerably improves location accuracy. Combining information across phones is especially useful when a phone has to use another phone’s fingerprint database, in a fingerprinting-based localization scheme. Both the median and 90 percentile errors reduce significantly. The location accuracy also improves irrespective of whether we combine information across phones connected to the same or different cellular operators. Sharing information across phones can raise privacy concerns. To address this, we have developed an id-free broadcast mechanism, using audio as a medium, to share information among mobile phones. We show that such communication can work effectively on smartphones, even in real-life, noisy-road conditions

A retrospective analysis of complications of laparoscopic left donor nephrectomy using the Kocak's modification of Clavien-Dindo system

Introduction: Kocak described a modification of Clavien-Dindo classification system (CDCS) for reporting procedure-related complications in laparoscopic donor nephrectomy (LDN). We used the Kocak modification in grading and reporting the severity of complications in patients who underwent LDN and in evaluating various parameters that predict them. Methods: In all, 1430 patients who underwent left LDN from 2000 to 2016 were included in this study. All data was retrospectively collected and analyzed for complications occurring in the postoperative period. All complications were classified according to the four grades of Kocak-modified CDCS. Results: 124 patients (8.6%) suffered a total of 235 postoperative complications. Most of the complications were Grade I and Grade II (Grade I: 79.5% [n = 187] and Grade II 16.2% [n = 38]), 2.5% of the complications were Grade III (n = 6) and Kocak Grade IVa complications occurred in three patients. There was one death (Grade IVb: 0.4%, overall mortality rate: 0.06%). The incidence of complications was significantly greater for male patients, those with body mass index ≥25 kg/m2, and if the operating surgeon had ≤ 1 year of experience in performing LDN surgery. Conclusion: LDN is a safe procedure with low morbidity. The rate of complications is 8.6% and most of these complications are of low grade. The use of a standardized system for reporting the complications of LDN allows appropriate comparison between reported data