Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

Analysis of shared heritability in common disorders of the brain

Paroxysmal Cerebral Disorder

Age and Growth of the Scalloped Hammerhead, Sphyrna lewini, in Northeastern Taiwan Waters

Age and growth of the scalloped hammerhead, Sphyrna lewini, caught mostly by longline and harpoon in northeastern Taiwan waters from December 1984 to November 1985, were determined from annulus counts from 325 individuals. Translucent and opaque zones on vertebral centra were formed twice a year, in June and December. The von Bertalanffy growth curve parameters obtained using a nonlinear regression based on age and observed length were as follows: asymptotic length (Loo) = 319.72 cm total length (TL), growth coefficient (K) = 0.249, age at zero length (to) = - 0.413 yr for females; and Loo = 320.59 cm TL, K = 0.222, to = - 0.746 yr for males. Growth was apparently fast and varied among individuals. Growth rate s for females were estimated to be 63cm for the first year, 23-50 cm/yr for years 2-5, and 3-19 cm/yr for years 6-13. Growth rates for males was 54 cm for the first year, 22-42 cm/yr for years 2-5, and 11-18 cm/yr for years 6-8. Holden's method was applied to estimate growth parameters for purposes of comparison. Estimated age at maturity was 4.lyr (210cmTL) for females and-3:8yr (198cm-TL) for males, based on the von Bertalanffy growth equation from back-calculated data. The largest female (331 cm TL) whose age was determined in this study was 14.0 yr old; the largest male (301 cm TL) was 10.6 yr old

Gastrointestinal nematode infection affects overall activity in young sheep monitored with tri-axial accelerometers

Animals suffering from parasitism typically display altered grazing behaviour and a voluntary reduction in feed intake. These changes are potentially important as indicators of disease. Recent advances in sensor technologies provide the opportunity to objectively measure animal activity while on pasture. Tri-axial accelerometers measure body movement in terms of acceleration, which can then be used to estimate physical activity over time. This study investigated if tri-axial measures of overall activity can be used to assess the impact of gastrointestinal nematode (GIN) infection in young sheep. To address this, the overall activity, faecal nematode egg count (FEC) and body weight of two treatment groups of Romney X Suffolk ram lambs were compared. Animals were monitored for four days using tri-axial accelerometer sensors mounted on a ram mating harness after 42-days grazing on contaminated pasture. On Day 0, all lambs were given anthelmintics. Subsequently, a Suppressive Treatment Group (n = 12) was treated with anthelmintics every two weeks. An Untreated Group (n = 12) did not receive further anthelmintics. Overall activity levels were monitored from Day 42 – 46. Activity level was calculated as vectorial dynamic body acceleration (VeDBA). Anthelmintic treatment had a significant effect on FEC but there was no evidence found for a treatment effect on body weight growth over the 42-day period. An effect of treatment and lamb starting weight on overall activity was found (beta = –0.74, 95 % CI –1.17 to –0.30, p =  0.002), identifying a negative impact of parasitism on activity in heavier animals. These results highlight the usefulness of this approach in assessing the effect of GIN parasitism on sheep monitored remotely. If a threshold value of activity could be determined, it could provide a useful tool for farmers and managers that serves as an early indicator of parasitism in sheep.Seer J.Ikurior, William E.Pomroy, Ian Scott, Rene Corner-Thomas, Nelly Marquetoux, Stephan T.Le

What are sheep doing? Tri‐axial accelerometer sensor data identify the diel activity pattern of ewe lambs on pasture

Monitoring activity patterns of animals offers the opportunity to assess individual health and welfare in support of precision livestock farming. The purpose of this study was to use a triaxial accelerometer sensor to determine the diel activity of sheep on pasture. Six Perendale ewe lambs, each fitted with a neck collar mounting a triaxial accelerometer, were filmed during targeted periods of sheep activities: grazing, lying, walking, and standing. The corresponding acceleration data were fitted using a Random Forest algorithm to classify activity (=classifier). This classifier was then applied to accelerometer data from an additional 10 ewe lambs to determine their activity budgets. Each of these was fitted with a neck collar mounting an accelerometer as well as two additional accelerometers placed on a head halter and a body harness over the shoulders of the animal. These were monitored continuously for three days. A classification accuracy of 89.6% was achieved for the grazing, walking and resting activities (i.e., a new class combining lying and standing activity). Triaxial accelerometer data showed that sheep spent 64% (95% CI 55% to 74%) of daylight time grazing, with grazing at night reduced to 14% (95% CI 8% to 20%). Similar activity budgets were achieved from the halter mounted sensors, but not those on a body harness. These results are consistent with previous studies directly observing daily activity of pasture-based sheep and can be applied in a variety of contexts to investigate animal health and welfare metrics e.g., to better understand the impact that young sheep can suffer when carrying even modest burdens of parasitic nematodes.Seer J. Ikurior, Nelly Marquetoux, Stephan T. Leu, Rene A. Corner-Thomas, Ian Scott and William E. Pomro

A Real-Time Intrusion Detection and Protection System at System Call Level under the Assistance of a Grid

Part 2: The 2014 Asian Conference on Availability, Reliability and Security, AsiaARES 2014International audienceIn this paper, we propose a security system, named the Intrusion Detection and Protection System (IDPS for short) at system call level, which creates personal profiles for users to keep track of their usage habits as the forensic features, and determines whether a legally login users is the owner of the account or not by comparing his/her current computer usage behaviors with the user’s computer usage habits collected in the account holder’s personal profile. The IDPS uses a local computational grid to detect malicious behaviors in a real-time manner. Our experimental results show that the IDPS’s user identification accuracy is 93%, the accuracy on detecting its internal malicious attempts is up to 99% and the response time is less than 0.45 sec., implying that it can prevent a protected system from internal attacks effectively and efficiently

Design of optimal step–stress accelerated life tests under progressive type I censoring with random removals

Progressive type I censoring with random removal (PCRR), Step–stress, Accelerated life testing, Asymptotic variance, Variance (V)-optimality, Determinant (D)-optimality,