Event Estimation Accuracy of Social Sensing with Facebook for Social Internet of Vehicles

© 2014 IEEE. Social Internet of Vehicles (SIoV) is a new paradigm that enables social relationships among vehicles via the Internet. People in the vehicles using online social networks (OSNs) can be an integral part of SIoV that enables the collection of data for sensing a physical phenomenon, i.e., social sensing. In this paper, we study the main social sensing mechanism in Facebook, comment thread network (CTN), which is based on the interactions of users through user walls in Facebook for SIoV. After seeing their commuters' contents about an event, users either add comments or like these posts, and Facebook CTN emerges as a social sensing medium in estimation of an event through social consensus. For the first time, this paper investigates the social sensing capability of Facebook CTN, i.e., the accuracy of collective observations for SIoV. The accuracy depends on the user characteristics and the features of the OSN, since perceptions of the users and how they use Facebook may manipulate their observation signals. We analyze the reliability of Facebook CTN for varying user behaviors, user relationships, Facebook features, and network size. The results indicate that the polarized weighting of the observations and the use of less reliable post types in CTN deteriorate the accuracy of the estimate signal, i.e., social consensus. Furthermore, the selection of users is likely to be an important factor in social sensing

Complications of limb salvage surgery in childhood tumors and recommended solutions

Bone and soft tissue malignancies are associated with serious diagnostic and therapeutic problems in every level of pubertal growth in children. Current treatment modality preferred in bone and soft tissue tumors is wide resection of tumor followed by the reconstruction of consequent defect by various methods. Chemotherapy and radiotherapy are applied for systemic effects to the patient pre- and post-operatively and for local effects that facilitate the surgical procedure. Mostly, it is very difficult to control problems following wide resection and reconstruction. In this study, our aim is to discuss the problems encountered in different resection and reconstruction approaches in childhood bone and soft tissue tumors, and the recommended solutions addressed to these problems. From 1990 to 2003, a total of 68 patients (38 female, 30 male) with a mean age of 13.1 (1.5–18) were included in the study. 85.3% of patients were diagnosed as osteosarcoma and the rest was Ewing’s sarcoma. Seventy-five percent of patients had stage IIB disease. The lesions of 34 patients were detected to be in distal femur, 26 in proximal tibia and fibula, 4 in foot and ankle joint, and the remaining 4 in pelvis. As reconstructive surgery, 40 patients had modular prosthesis, vascularized fibular graft was performed in 13 patients, and 10 patients underwent arthrodesis with vascularized fibular graft. 20.6% of patients had shortened limb, infection was detected in 4 patients, laxity in 5, and restricted motion in 4 as complication of prosthesis. With sacrificed physis, 13 patients had a mean value of 4.6 cm limb shortness. Limb salvage surgery has been considered as the gold standard treatment in orthopedic oncological surgery. More understanding of the biology of sarcoma, introduction of new effective chemotherapeutic agents, development of new techniques concerning the surgical resection, advances in diagnostic methods, and improvements in reconstructive surgery all make a major contribution to limb salvage surgery. Since some problems are still encountered, we offer a therapeutic algorithm for complications in the management of childhood tumors that we have encountered so far

Clustering in Multi-Channel Cognitive Radio Ad Hoc and Sensor Networks

© 1979-2012 IEEE. CR enables dynamic spectrum access to utilize licensed spectrum when it is idle. CR technology is applied to wireless ad hoc and sensor networks to form CRAHNs and CRSNs, respectively. Clustering is an efficient topology management technique to regulate communication and allocate spectrum resources by CR capabilities of nodes in CRAHNs and CRSNs. In this article, we thoroughly investigate the benefits and functionalities of clustering such as topology, spectrum, and energy management in these networks. We also overview motivations for and challenges of clustering in CRAHNs and CRSNs. Existing clustering schemes are reviewed and compared. We conclude by revealing key considerations and possible solutions for spectrum-aware clustering in multi-channel CRAHNs and CRSNs

Internet of Hybrid Energy Harvesting Things

© 2017 IEEE. Internet of Things (IoT) is a perfect candidate to realize efficient observation and management for Smart City concept. This requires deployment of large number of wireless devices. However, replenishing batteries of thousands, maybe millions of devices may be hard or even impossible. In order to solve this problem, Internet of Energy Harvesting Things (IoEHT) is proposed. Although the first studies on IoEHT focused on energy harvesting (EH) as an auxiliary power provisioning method, now completely battery-free and self-sufficient systems are envisioned. Taking advantage of diverse sources that the concept of Smart City offers helps us to fully appreciate the capacity of EH. In this way, we address the primary shortcomings of IoEHT; availability, unreliability, and insufficiency by the Internet of Hybrid EH Things (IoHEHT). In this paper, we survey the various EH opportunities, propose an hybrid EH system, and discuss energy and data management issues for battery-free operation. We mathematically prove advantages of hybrid EH compared to single source harvesting as well. We also point out to hardware requirements and present the open research directions for different network layers specific to IoHEHT for Smart City concept

Harvesting-throughput trade-off for wireless-powered smart grid IoT applications: An experimental study

© 2018 IEEE. Sensor nodes, one of the most crucial elements of Internet of Things (IoT), sense the environment and send their observations to a remote Access Point (AP). One drawback of sensor nodes in an IoT setting is their limited battery supply. Hereby, energy harvesting (EH) stands as a promising solution to reduce or even completely eliminate lifetime constraints of sensors with exploitation of available resources. In this paper, we propose an electric-field EH (EFEH) method to enable battery-less execution of sensor-based IoT services for Smart Grid (SG) context. For this purpose, for the first time in the literature, harvestable energy through EFEH method is investigated with a transformer room experimental set-up. Our experiments reveal that 40 mJ of energy can be harvested in a period of 900 sec with the proposed EFEH method. Building on this energy profile, we define a throughput objective function θ for a «harvest-then-transmit» type system model, to shed light on the harvesting- throughput trade-off specific to IoT-assisted SG applications. Numerical results disclose non- trivial relationships between optimal harvesting period T-H, optimal transmission period T-T and critical network parameters such as node-AP hop distance, path loss exponent and minimum reporting frequency requirement

Paying attention to the evidence: a comparison of perception and decision making processes in novice and experienced scene of crime officers using eye tracking in simulated crime scene scenarios

Research on crime scene investigation has strongly focused on the technical aspects of the process, while cognitive aspects (searching, reasoning and perception) have often been overlooked. Textbooks on forensic sciences tend to focus on identifying and processing evidence, and the use of equipment while it can be argued that cognitive factors in processing such evidence and using equipment are equally important. This thesis studies the cognitive aspects of crime scene investigation by comparing eye movement patterns in experts and novices. Studies in various domains, including surgery, sports, and chess playing have shown that eye movements differ between experts and novices, providing a tool towards a more objective assessment of skill than is possible with peer assessment. In four experiments eye movements of experts and novices were examined during (1) inspection of photographs of crime scenes on a computer screen (2) a change blindness task on crime and non-crime scene images, (3) active exploration of a simulated crime scene and (4) the assessment of emotional crime and natural scenes. While some trends in eye movement differences, such as a tendency on longer fixation durations and a broader focus on the overall scene and less on the direct evidence could be found in experts compared to novices, differences between experts and novices were considerably smaller than in other domains, despite the broad range of measures extracted from the data. This lack of clear expertise effects may relate to the rather diverse range of perceptual layouts of crime scenes, reducing possible top-down effects of expertise on the deployment of attention. The results will be discussed with a view of possible directions of future research in this domain