The Design of Efficient Internetwork Authentication for Ubiquitous Wireless Communications

A variety of wireless technologies have been standardized and commercialized, but no single solution is considered the best to satisfy all communication needs due to different coverage and bandwidth limitations. Therefore, internetworking between heterogeneous wireless networks is extremely important for ubiquitous and high performance wireless communications. The security problem is one of the major challenges in internetworking. To date, most research on internetwork authentication has focused on centralized authentication approaches, where the home network participates in each authentication process. For high latency between the home and visiting networks, such approaches tend to be inefficient. In this paper, we describe chained authentication, which requires collaboration between adjacent networks without involvement of the home network. After categorizing chained protocols, we propose a novel design of chained authentication methods under 3G-WLAN internetworking. The experiments show that proactive context transfer and ticket forwarding reduce the 3G authentication latency to 36.8% and WLAN EAP-TLS latency to 23.1% when RTT between visiting and home networks is 200 ms

Multiple Sensor Linear Multi-Target Integrated Probabilistic Data Association for Ultra-Wide Band Radar

Ultra-Wide Band (UWB) radar has a number of advantages of resolving multipath, exceptional spatial resolution, and ranging performance. However, several difficulties are confronted for multiple target tracking using UWB radars such as clutter signals which contaminate target signals, and unidentified number and behavior of the targets. Hence, this paper presents to develop a multiple moving target tracking algorithm, consisting of preprocessing and multiple target tracking steps. In the preprocessing step, static clutter reduction and constant false alarm rate (CFAR) detection extract the target candidate range measurements from each UWB radar. Then, two multiple target tracking (MTT) steps are developed: range- based MTT and position-based MTT. The range-based MTT is mainly based on existing linear multi-target integrated probabilistic data association (LM-IPDA) from each UWB radar measurement. Then the outputs of each LM-IPDA are gathered in the positioning center to estimate the position of multiple targets. On the other hands, the position-based MTT is based on multiple sensor LM-IPDA (msLM-IPDA) as an accurate target tracking method for various uncertainties by improving the probabilistic model of LM-IPDA. The tracking performance of two MTT methods is investigated with both numerical simulation and experiments

MPCS: Mobile-based Patient Compliance System for Chronic Illness Care

More than 100 million Americans are currently living with at least one chronic health condition and expenditures on chronic diseases account for more than 75 percent of the $2.3 trillion cost of our healthcare system. To improve chronic illness care, patients must be empowered and engaged in health self-management. However, only half of all patients with chronic illness comply with treatment regimen. The self-regulation model, while seemingly valuable, needs practical tools to help patients adopt this self-centered approach for long-term care. \par In this position paper, we propose Mobile-phone based Patient Compliance System (MPCS) that can reduce the time-consuming and error-prone processes of existing self-regulation practice to facilitate self-reporting, non-compliance detection, and compliance reminders. The novelty of this work is to apply social-behavior theories to engineer the MPCS to positively influence patients\u27 compliance behaviors, including mobile-delivered contextual reminders based on association theory; mobile-triggered questionnaires based on self-perception theory; and mobile-enabled social interactions based on social-construction theory. We discuss the architecture and the research challenges to realize the proposed MPCS

Location Privacy for Mobile Crowd Sensing through Population Mapping

Opportunistic sensing allows applications to “task” mobile devices to measure context in a target region. For example, one could leverage sensor-equipped vehicles to measure traffic or pollution levels on a particular street or users\u27 mobile phones to locate (Bluetooth-enabled) objects in their vicinity. In most proposed applications, context reports include the time and location of the event, putting the privacy of users at increased risk: even if identifying information has been removed from a report, the accompanying time and location can reveal sufficient information to de-anonymize the user whose device sent the report. We propose and evaluate a novel spatiotemporal blurring mechanism based on tessellation and clustering to protect users\u27 privacy against the system while reporting context. Our technique employs a notion of probabilistic k-anonymity; it allows users to perform local blurring of reports efficiently without an online anonymization server before the data are sent to the system. The proposed scheme can control the degree of certainty in location privacy and the quality of reports through a system parameter. We outline the architecture and security properties of our approach and evaluate our tessellation and clustering algorithm against real mobility traces

MPCS: Mobile-based Patient Compliance System for Chronic Illness Care

More than 100 million Americans are currently living with at least one chronic health condition and expenditures on chronic diseases account for more than 75 percent of the $2.3 trillion cost of our healthcare system. To improve chronic illness care, patients must be empowered and engaged in health self-management. However, only half of all patients with chronic illness comply with treatment regimen. The self-regulation model, while seemingly valuable, needs practical tools to help patients adopt this self-centered approach for long-term care. \par In this position paper, we propose Mobile-phone based Patient Compliance System (MPCS) that can reduce the time-consuming and error-prone processes of existing self-regulation practice to facilitate self-reporting, non-compliance detection, and compliance reminders. The novelty of this work is to apply social-behavior theories to engineer the MPCS to positively influence patients\u27 compliance behaviors, including mobile-delivered contextual reminders based on association theory; mobile-triggered questionnaires based on self-perception theory; and mobile-enabled social interactions based on social-construction theory. We discuss the architecture and the research challenges to realize the proposed MPCS

Improving the Latency of 802.11 hand-offs using Neighbor Graphs

The 802.11 IEEE Standard has enabled low cost and effective wireless LAN services (WLAN). With the sales and deployment of WLAN based networks exploding, many people believe that they will become the fourth generation cellular system (4G) or a major portion of it. However, the small cell size of WLAN networks creates frequent hand-offs for mobile users. If the latency of these hand-offs is high, as previous studies have shown, then the users of synchronous multimedia applications such as voice over IP (VoIP) will experience excessive jitter. The dominating factor in WLAN hand-offs has been shown to be the discovery of the candidate set of next access points. In this paper, we describe the use of a novel and efficient discovery method using neighbor graphs and overlap graphs. Our method reduces the total number probed channels as well as the total time spent waiting on each channel. Our implementation results show that this approach reduces the overall probe time significantly when compared to other approaches. Furthermore, simulation results show that the effectiveness of our method improves as the number of non-overlapping channels increases, such as in the 5 GHz band used by the IEEE 802.11a standard. (UMIACS-TR-2003-118

AnonySense: A System for Anonymous Opportunistic Sensing

We describe AnonySense, a privacy-aware system for realizing pervasive applications based on collaborative, opportunistic sensing by personal mobile devices. AnonySense allows applications to submit sensing \emphtasks\/ to be distributed across participating mobile devices, later receiving verified, yet anonymized, sensor data \emphreports\/ back from the field, thus providing the first secure implementation of this participatory sensing model. We describe our security goals, threat model, and the architecture and protocols of AnonySense. We also describe how AnonySense can support extended security features that can be useful for different applications. We evaluate the security and feasibility of AnonySense through security analysis and prototype implementation. We show the feasibility of our approach through two plausible applications: a Wi-Fi rogue access point detector and a lost-object finder

AnonyTL Specification

We provide a specification of AnonyTL, a domain-specific language that describes sensing tasks for mobile devices in a manner that facilitates automated reasoning about privacy

Channel Assignment for Multiple Interface Nodes in Wireless Ad

In wireless networks, due to the broadcast property of the medium, nodes close to each other cannot simultaneously transmit over the same channel. One way to overcome this limitation is to use multiple independent channels available in the system. Although we can use a single wireless interface card to access multiple channels, such schemes can raise issues of compatibility (e.g., modication of the MAC protocol) and performance degradation (e.g., due to frequent channel switching). In this paper, we assume that nodes are equipped with multiple interface cards, and focus on the channel assignment problem for minimizing the total number of interferences among wireless links. We show that the problem is NP-hard and present distributed heuristics. We also present two centralized algorithms and show that the algorithms give constant factor approximation guarantees. We perform simulation experiments for the proposed distributed heuristic. The results show that compared to one-channel scenarios, our proposed algorithm can reduce the number of interferences by up to 85% when nodes are equipped with four interface cards. Through detailed packetlevel simulation experiments, we also show that depending on the scenario, the resulting channel assignment actually achieves up to seven times throughput improvement over the single-channel case

Efficacy and safety of transcatheter arterial embolization for active arterial esophageal bleeding: a single-center experience

PURPOSEThe study aimed to evaluate the safety and clinical efficacy of transcatheter arterial embolization (TAE) for the treatment of arterial esophageal bleeding.METHODSNine patients (8 male, 1 female; mean age, 62.3±7.5 years) who underwent TAE for arterial esophageal bleeding between January 2004 and January 2020 were included. Preceding endoscopic treatment was unsuccessful in five patients and was not attempted in four patients due to the non-cooperation of the patients in endoscopic treatment. The etiologies of bleeding were esophageal cancer (n=4), Mallory-Weiss syndrome (n=3), erosive esophagitis (n=1), and esophageal ulcer (n=1). Technical and clinical success, recurrent bleeding, procedure-related complications, and clinical outcomes were retrospectively reviewed.RESULTSThe angiographic findings for bleeding were contrast media extravasation (n=8) or tumor staining without a definite bleeding focus (n=1). The bleeding focus at the distal esophagus (n=8) was the left gastric artery, whereas that at the middle esophagus (n=1) was the right bronchial artery. Technical success was achieved in all patients. The embolic agents were n-butyl cyanoacrylate (NBCA, n=5), gelatin sponge particles (n=2), microcoils (n=1), and NBCA with gelatin sponge particles (n=1). Clinical success was achieved in 77.8% of cases (7/9); two patients with recurrent bleeding one day after the first TAE showed culprit arteries different from the bleeding foci at the first TAE. One patient who underwent embolization of both the left and short gastric arteries died of gastric infract/perforation one month after TAE.CONCLUSIONTAE can be an alternative to the treatment of arterial esophageal bleeding. TAE can be attempted in the treatment of recurrent bleeding, but there is a risk of ischemia/infarct in the gastrointestinal tract involved