Self-configuring indoor localization based on low-cost ultrasonic range sensors.

In smart environments, target tracking is an essential service used by numerous applications from activity recognition to personalized infotaintment. The target tracking relies on sensors with known locations to estimate and keep track of the path taken by the target, and hence, it is crucial to have an accurate map of such sensors. However, the need for manually entering their locations after deployment and expecting them to remain fixed, significantly limits the usability of target tracking. To remedy this drawback, we present a self-configuring and device-free localization protocol based on genetic algorithms that autonomously identifies the geographic topology of a network of ultrasonic range sensors as well as automatically detects any change in the established network structure in less than a minute and generates a new map within seconds. The proposed protocol significantly reduces hardware and deployment costs thanks to the use of low-cost off-the-shelf sensors with no manual configuration. Experiments on two real testbeds of different sizes show that the proposed protocol achieves an error of 7.16~17.53 cm in topology mapping, while also tracking a mobile target with an average error of 11.71~18.43 cm and detecting displacements of 1.41~3.16 m in approximately 30 s.

Energy-efficient privacy protection for smart home environments using behavioral semantics.

Research on smart environments saturated with ubiquitous computing devices is rapidly advancing while raising serious privacy issues. According to recent studies, privacy concerns significantly hinder widespread adoption of smart home technologies. Previous work has shown that it is possible to infer the activities of daily living within environments equipped with wireless sensors by monitoring radio fingerprints and traffic patterns. Since data encryption cannot prevent privacy invasions exploiting transmission pattern analysis and statistical inference, various methods based on fake data generation for concealing traffic patterns have been studied. In this paper, we describe an energy-efficient, light-weight, low-latency algorithm for creating dummy activities that are semantically similar to the observed phenomena. By using these cloaking activities, the amount of  fake data transmissions can be flexibly controlled to support a trade-off between energy efficiency and privacy protection. According to the experiments using real data collected from a smart home environment, our proposed method can extend the lifetime of the network by more than 2× compared to the previous methods in the literature. Furthermore, the activity cloaking method supports low latency transmission of real data while also significantly reducing the accuracy of the wireless snooping attacks.

[Penetrating cardiac injuries]. / Penetran kalp yaralanmalari

BACKGROUND: The aim of this study was to evaluate our clinical findings and results of cardiac injuries. METHODS: We reviewed the records of patients who were admitted to our clinic between 1996 and 2005 and operated due to penetrating cardiac injury. RESULTS: Eighteen patients (17 male, one female; mean age 25.9; range 17-45 years) (all penetrating stab wounds) with cardiac injuries were operated. The clinical aspects were: agonal status in 5 patients (27.8%), profound shock in 7 patients (38.9%). The remaining 6 patients (33.3%) were in mild shock (hypotension 60-90 mmHg) and 3 of them (16.7%) had a diagnosis of cardiac tamponade preoperatively. Emergency room thoracotomy was made in 2 patients (11.1%). Mortality rate was %80 in agonal patients whereas overall mortality was 44.5%. CONCLUSION: Cardiac injuries have high mortality. The mortality rate of the patients, who can arrive to the hospital alive, is closely related to the vital signs and general condition. The mortality can be reduced by quick evaluation and prompt surgical intervention.

A case of solid pseudopapillary tumor of the pancreas.

We present ultrasound, computed tomography and magnetic resonance imaging findings in a case with pancreatic solid pseudopapillary tumor and their correlations with histopathology. Ultrasound revealed a hypoechogenic mass, and computed tomography revealed a hypodense mass at the pancreatic head minimally enhanced after intravenous contrast agent administration. Magnetic resonance imaging showed a hypointense mass on unenhanced T1-weighted images including a hyperintense focus representing the hemorrhage. The lesion was hyperintense on T2-weighted images. On the postcontrast images the lesion showed peripheral thin contrast enhancement in arterial phase and enhanced slightly diffusely in venous and equilibrium phases. The patient underwent elective resection of the mass and pancreatoduodenectomy with jejunostomy tube placement. A final diagnosis of solid pseudopapillary tumor was made histopathologically. Solid pseudopapillary tumor is a rare pancreatic tumor. It is important to make the diagnosis preoperatively because with an adequate surgical resection the prognosis is good. A multimodalitary approach, especially magnetic resonance imaging can suggest the diagnosis without the need for biopsy.