Towards reliable geographic broadcasting in vehicular networks

In Vehicular ad hoc Networks (VANETs), safety-related messages are broadcasted amongst cars, helping to improve drivers' awareness of the road situation. VANETs’ reliability are highly affected by channel contention. This thesis first addresses the issue of channel use efficiency in geographical broadcasts (geocasts). Constant connectivity changes inside a VANET make the existing routing algorithms unsuitable. This thesis presents a geocast algorithm that uses a metric to estimate the ratio of useful to useless packet received. Simulations showed that this algorithm is more channel-efficient than the farthest-first strategy. It also exposes a parameter, allowing it to adapt to channel load. Second, this thesis presents a method of estimating channel load for providing feedback to moderate the offered load. A theoretical model showing the relationship between channel load and the idle time between transmissions is presented and used to estimate channel contention. Unsaturated stations on the network were shown to have small but observable effects on this relationship. In simulations, channel estimators based on this model show higher accuracy and faster convergence time than by observing packet collisions. These estimators are also less affected by unsaturated stations than by observing packet collisions. Third, this thesis couples the channel estimator to the geocast algorithm, producing a closed-loop load-reactive system that allows geocasts to adapt to instantaneous channel conditions. Simulations showed that this system is not only shown to be more efficient in channel use and be able to adapt to channel contention, but is also able to self-correct suboptimal retransmission decisions. Finally, this thesis demonstrates that all tested network simulators exhibit unexpected behaviours when simulating broadcasts. This thesis describes in depth the error in ns-3, leading to a set of workarounds that allows results from most versions of ns-3 to be interpreted correctly

Should dyslexic children stop copying? Exploring the relationship between word reading, copying and dictation?

Interactive Poste

The next generation for the forensic extraction of electronic evidence from mobile telephones

Electronic evidence extracted from a mobile telephone provide a wealth of information about the user. Before a court allows the trier of fact to consider the electronic evidence, the court must ensure that the subject matter, testimony of which is to be given, is scientific. Therefore, regard must, at the investigation stage, be given to fulfill the requirements of science and law, including international standards. Such compliance also moves the extraction of electronic evidence from mobile telephones into the next generation, a more rigorous position as a forensic science, by being able to give in court well- reasoned and concrete claims about the accuracy and validity of conclusions.published_or_final_versio

Gap junction inhibition by heptanol increases ventricular arrhythmogenicity by reducing conduction velocity without affecting repolarization properties or myocardial refractoriness in Langendorff-perfused mouse hearts.

This is the final version of the article. It first appeared from Spandidos via https://doi.org/ 10.3892/mmr.2016.5738In the current study, arrhythmogenic effects of the gap junction inhibitor heptanol (0.05 mM) were examined in Langendorff-perfused mouse hearts. Monophasic action potential recordings were obtained from the left ventricular epicardium during right ventricular pacing. Regular activity was observed both prior and subsequent to application of heptanol in all of the 12 hearts studied during 8 Hz pacing. By contrast, induced ventricular tachycardia (VT) was observed after heptanol treatment in 6/12 hearts using a S1S2 protocol (Fisher's exact test; P0.05). Consequently, excitation wavelengths (λ; CV x ERP) were reduced from 9.1±0.6 to 6.5±0.6 mm (P0.05). Together, these observations demonstrate for the first time, to the best of our knowledge, that inhibition of gap junctions alone using a low heptanol concentration (0.05 mM) was able to reduce CV, which alone was sufficient to permit the induction of VT using premature stimulation by reducing λ, which therefore appears central in the determination of arrhythmic tendency.GT was awarded a BBSRC Doctoral Training Award at the University of Cambridge

The mind contemplating “light and refraction” and “light and shade”: Blending art and science in education

Art and science often seem or are presented as being dichotomous. Accordingly, art is subjective whereas science is objective. Thus, too, art is about irrational feelings whilst science concerns itself solely with rational information. In fact, rather than see them as polar opposites, we should see them as different manifestations and incarnations stemming from the self-same source of human creativity. From what we know of the early days of human existence, as revealed by anthropology and the social, human and natural sciences in general, humans have always been involved in art-making and experimentation. From cave paintings and the mastery of fire-making through to pottery, both domains, i.e., science and art have evolved together as human culture has progressed. With the Industrial Revolution, we began to teach specialisation in one domain or the other and, entrenched within these now-divorced knowledge domains, to specialise even further into ever more specific fields. Thus, the specificity and inner gravity, so to speak, of highly specialised knowledge further widened the gap between the domains of art and science. As a result of this phenomenon of specialisation, art and science drifted apart in academia, finally crystallizing into separate subjects taught, in turn, by specialised individuals. This phenomenon of specialization and exclusionary knowledge practices ultimately steered me in the direction of art, thus leading me further away from the domain of science. Fortuitously, glass making opened a path for me to get to know science better as well as ignited my scientific curiosity. The artist and the scientist's creative life are made up moments of epiphany: moments which have led me to a more nuanced and deeper level of personal achievement and satisfaction. Specifically, my epiphanic moment has allowed me to embrace various science projects, producing glass and analyzing their properties, and engage with science to solve the technical problems arising during the process of art-making. Nowadays, I see science and art as related manifestations and both as the culmination of experiment and creativity. Both are, in their purest forms, deeply creative endeavours which bring us closer together as living, thinking beings and help us to transcend our limited, i.e., specialised perspectives. It is our belief that the merging of art and science in education will allow us to surpass the barriers of even the most deeply entrenched and dichotomous thought patterns. Based on my experience of travelling between these two avatars of human creativity, the thesis reflects upon the value of, and need for, the reconciliation and reintegration of art and science in education. By engaging in transdisciplinary research, I have rediscovered myself and, consequently, discovered my ability to blend art and science. This thesis, in addition to my artwork, shows the results of my forays into art and science, i.e., the pursuit of mature creative, conceptual and pedagogical expression by way of distinct yet related modes of knowing and communicating, experimenting and creating

Studies in the coordination chemistry of phospholes

The chemical, physicochemical, theoretical and metal coordination studies of phospholes which have so far appeared in the literature are reviewed briefly with particular reference to the electronic structure of the system. The coordinating properties of the simple phospholes 1-phenylphosphole (PP), 3-methyl-1-phenylphosphole (mPP), 3,4- dimethyl-l-phenylphosphole (dPP) and 3,4-dimethyl-1-rwbutylphosphole (dBP) with the metal ions Re(III), Ru(III), Ru(II), Co{II), Rh(III), Ir(III), Ni(II), Pd(II), Pt(II), Cu(I) and Hg(II) and also with carbonyl complexes of Ru(II) and Rh(I) have been studied. ... Differences in the behavior of the various phospholes studied here, and also other phospholes, in complex formation are attributed to variations in the substitution pattern with the type of substitution at the phosphorus atom being apparently of particular importance. The results are discussed in terms of orbital perturbation of a pyramidal phosphole in which the HOMO may not be the lone-pair orbital and also in terms of a pyramidal but aromatic phosphole system

Analyzing storage media of digital camera

Digital photography has become popular in recent years. Photographs have become common tools for people to record every tiny parts of their daily life. By analyzing the storage media of a digital camera, crime investigators may extract a lot of useful information to reconstruct the events. In this work, we will discuss a few approaches in analyzing these kinds of storage media of digital cameras. A hypothetical crime case will be used as case study for demonstration of concepts. © 2009 IEEE.published_or_final_versionThe 2009 International Workshop on Forensics for Future Generation Communication Environments (F2GC-09) in conjunction with CSA 2009, Jeju Island, Korea, 10-12 December 2009. In Proceedings of CSA, 2009, p. 1-

Memory acquisition: A 2-Take approach

When more and more people recognize the value of volatile data, live forensics gains more weight in digital forensics. It is often used in parallel with traditional pull-the-plug forensics to provide a more reliable result in forensic examination. One of the core components in live forensics is the collection and analysis of memory volatile data, during which the memory content is acquired for searching of relevant evidential data or investigating various computer processes to unveil the activities being performed by a user. However, this conventional method may have weaknesses because of the volatile nature of memory data and the absence of original data for validation. This may cause implication to the admissibility of memory data at the court of law which requires strict authenticity and reliability of evidence. In this paper, we discuss the impact of various memory acquisition methods and suggest a 2-Take approach which aims to enhance the confidence level of the acquired memory data for legal proceedings. © 2009 IEEE.published_or_final_versionThe 2009 International Workshop on Forensics for Future Generation Communication Environments (F2GC-09) in conjunction with CSA 2009, Jeju Island, Korea, 10-12 December 2009. In Proceedings of CSA, 2009, p. 1-

Isolated heart models for studying cardiac electrophysiology: a historical perspective and recent advances

Experimental models used in cardiovascular research range from cellular to whole heart preparations. Isolated whole hearts show higher levels of structural and functional integration than lower level models such as tissues or cellular fragments. Cardiovascular diseases are multi-factorial problems that are dependent on highly organized structures rather than on molecular or cellular components alone. This article first provides a general introduction on the animal models of cardiovascular diseases. It is followed by a detailed overview and a historical perspective of the different isolated heart systems with a particular focus on the Langendorff perfusion method for the study of cardiac arrhythmias. The choice of species, perfusion method, and perfusate composition are discussed in further detail with particular considerations of the theoretical and practical aspects of experimental settings

Cerebral involvement in neuromyelitis optica spectrum disorders among Hong Kong Chinese

published_or_final_versionThe 16th Medical Resarch Conference (MRC), The University of Hong Kong, Hong Kong, China, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17, suppl. 1, p. 55, abstract no. 8