Enhanced Position Verification for VANETs using Subjective Logic

The integrity of messages in vehicular ad-hoc networks has been extensively studied by the research community, resulting in the IEEE~1609.2 standard, which provides typical integrity guarantees. However, the correctness of message contents is still one of the main challenges of applying dependable and secure vehicular ad-hoc networks. One important use case is the validity of position information contained in messages: position verification mechanisms have been proposed in the literature to provide this functionality. A more general approach to validate such information is by applying misbehavior detection mechanisms. In this paper, we consider misbehavior detection by enhancing two position verification mechanisms and fusing their results in a generalized framework using subjective logic. We conduct extensive simulations using VEINS to study the impact of traffic density, as well as several types of attackers and fractions of attackers on our mechanisms. The obtained results show the proposed framework can validate position information as effectively as existing approaches in the literature, without tailoring the framework specifically for this use case.Comment: 7 pages, 18 figures, corrected version of a paper submitted to 2016 IEEE 84th Vehicular Technology Conference (VTC2016-Fall): revised the way an opinion is created with eART, and re-did the experiments (uploaded here as correction in agreement with TPC Chairs

Open issues in differentiating misbehavior and anomalies for VANETs

This position paper proposes new challenges in data-centric misbehavior detection for vehicular ad-hoc networks (VANETs). In VANETs, which aim to improve safety and efficiency of road transportation by enabling communication between vehicles, an important challenge is how vehicles can be certain that messages they receive are correct. Incorrectness of messages may be caused by malicious participants, damaged sensors, delayed messages or they may be triggered by software bugs. An essential point is that due to the wide deployment in these networks, we cannot assume that all vehicles will behave correctly. This effect is stronger due to the privacy requirements, as those requirements include multiple certificates per vehicle to hide its identity. To detect these incorrect messages, the research community has developed misbehavior data-centric detection mechanisms, which attempt to recognize the messages by semantically analyzing the content. The detection of anomalous messages can be used to detect and eventually revoke the certificate of the sender, if the message was malicious. However, this approach is made difficult by rare events –such as accidents–, which are essentially anomalous messages that may trigger the detection mechanisms. The idea we wish to explore in this paper is how attack detection may be improved by also considering the detection of specific types of anomalous events, such as accidents

High quality ultrafast transmission electron microscopy using resonant microwave cavities

Ultrashort, low-emittance electron pulses can be created at a high repetition rate by using a TM$_{110}$ deflection cavity to sweep a continuous beam across an aperture. These pulses can be used for time-resolved electron microscopy with atomic spatial and temporal resolution at relatively large average currents. In order to demonstrate this, a cavity has been inserted in a transmission electron microscope, and picosecond pulses have been created. No significant increase of either emittance or energy spread has been measured for these pulses. At a peak current of $814\pm2$ pA, the root-mean-square transverse normalized emittance of the electron pulses is $\varepsilon_{n,x}=(2.7\pm0.1)\cdot 10^{-12}$ m rad in the direction parallel to the streak of the cavity, and $\varepsilon_{n,y}=(2.5\pm0.1)\cdot 10^{-12}$ m rad in the perpendicular direction for pulses with a pulse length of 1.1-1.3 ps. Under the same conditions, the emittance of the continuous beam is $\varepsilon_{n,x}=\varepsilon_{n,y}=(2.5\pm0.1)\cdot 10^{-12}$ m rad. Furthermore, for both the pulsed and the continuous beam a full width at half maximum energy spread of $0.95\pm0.05$ eV has been measured

Leadership Adaptability Within Higher Education

Dynamism in the higher education industry (HEI) has created unprecedented complexity and uncertainty for leaders at colleges and universities across the globe. The challenges to competitive advantage and sustainability created by dynamic conditions have been exacerbated and accelerated by the COVID-19 pandemic and health crisis. HEI leaders are struggling to adapt antiquated and traditionally held methods and practices to navigate the rapid changes and survive the resulting chaos. The ability of leaders to adapt to dynamism in contemporary industry conditions is influenced by the external and internal environments; in term, these leaders’ capacity for change impacts the adaptability of the institutions they serve. This study examines how senior- and mid-level leaders at small private liberal arts colleges and universities are engaging in adaptive behaviors to help their organizations better compete despite challenges

Theory and particle tracking simulations of a resonant radiofrequency deflection cavity in TM110_{110} mode for ultrafast electron microscopy

We present a theoretical description of resonant radiofrequency (RF) deflecting cavities in TM$_{110}$ mode as dynamic optical elements for ultrafast electron microscopy. We first derive the optical transfer matrix of an ideal pillbox cavity and use a Courant-Snyder formalism to calculate the 6D phase space propagation of a Gaussian electron distribution through the cavity. We derive closed, analytic expressions for the increase in transverse emittance and energy spread of the electron distribution. We demonstrate that for the special case of a beam focused in the center of the cavity, the low emittance and low energy spread of a high quality beam can be maintained, which allows high-repetition rate, ultrafast electron microscopy with 100 fs temporal resolution combined with the atomic resolution of a high-end TEM. This is confirmed by charged particle tracking simulations using a realistic cavity geometry, including fringe fields at the cavity entrance and exit apertures

Direct magneto-optical compression of an effusive atomic beam for high-resolution focused ion beam application

An atomic rubidium beam formed in a 70 mm long two-dimensional magneto-optical trap (2D MOT), directly loaded from a collimated Knudsen source, is analyzed using laser-induced fluorescence. The longitudinal velocity distribution, the transverse temperature and the flux of the atomic beam are reported. The equivalent transverse reduced brightness of an ion beam with similar properties as the atomic beam is calculated because the beam is developed to be photoionized and applied in a focused ion beam. In a single two-dimensional magneto-optical trapping step an equivalent transverse reduced brightness of $(1.0\substack{+0.8-0.4})$ $\times 10^6$ A/(m$^2$ sr eV) was achieved with a beam flux equivalent to $(0.6\substack{+0.3-0.2})$ nA. The temperature of the beam is further reduced with an optical molasses after the 2D MOT. This increased the equivalent brightness to $(6\substack{+5-2})$$\times 10^6$ A/(m$^2$ sr eV). For currents below 10 pA, for which disorder-induced heating can be suppressed, this number is also a good estimate of the ion beam brightness that can be expected. Such an ion beam brightness would be a six times improvement over the liquid metal ion source and could improve the resolution in focused ion beam nanofabrication.Comment: 10 pages, 8 figures, 1 tabl

Soluble adhesion molecules as markers for sepsis and the potential pathophysiological discrepancy in neonates, children and adults

Sepsis is a severe and life-threatening systemic inflammatory response to infection that affects all populations and age groups. The pathophysiology of sepsis is associated with aberrant interaction between leukocytes and the vascular endothelium. As inflammation progresses, the adhesion molecules that mediate these interactions become shed from cell surfaces and accumulate in the blood as soluble isoforms that are being explored as potential prognostic disease biomarkers. We critically review the studies that have tested the predictive value of soluble adhesion molecules in sepsis pathophysiology with emphasis on age, as well as the underlying mechanisms and potential roles for inflammatory shedding. Five soluble adhesion molecules are associated with sepsis, specifically, E-selectin, L-selectin and P-selectin, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. While increased levels of these soluble adhesion molecules generally correlate well with the presence of sepsis, their degree of elevation is still poorly predictive of sepsis severity scores, outcome and mortality. Separate analyses of neonates, children and adults demonstrate significant age-dependent discrepancies in both basal and septic levels of circulating soluble adhesion molecules. Additionally, a range of both clinical and experimental studies suggests protective roles for adhesion molecule shedding that raise important questions about whether these should positively or negatively correlate with mortality. In conclusion, while predictive properties of soluble adhesion molecules have been researched intensively, their levels are still poorly predictive of sepsis outcome and mortality. We propose two novel directions for improving clinical utility of soluble adhesion molecules: the combined simultaneous analysis of levels of adhesion molecules and their sheddases; and taking age-related discrepancies into account. Further attention to these issues may provide better understanding of sepsis pathophysiology and increase the usefulness of soluble adhesion molecules as diagnostic and predictive biomarkers

Финансово-экономические составляющие инвестиционного климата России при привлечении прямых иностранных инвестиций

В статье раскрываются финансово-экономические особенности с выделением реальных как благоприятных, так и неблагоприятных причин и факторов, способствующих развитию инвестиционного климата России при привлечении прямых иностранных инвестиций. Отражены факторы, реально сдерживающие качественное продвижение в российскую экономику иностранных инвестиций. Выделены конкретные правовые нарушения, способствующие сдерживать полноценную внешнеэкономическую деятельность предприятий сырьевой и перерабатывающей сферы. Сделан вывод, в котором выделены конкретные мероприятия, способствующие стабилизации инвестиционного климата в России.У статті розкриваються фінансово-економічні особливості з виділенням реальних як сприятливих, так і несприятливих причин і факторів, що сприяють розвитку інвестиційного клімату Росії при залученні прямих іноземних інвестицій. Відбиті фактори, що реально стримують якісне просування в російську економіку іноземних інвестицій. Виділено конкретні правові порушення, що сприяють стримувати повноцінну зовнішньоекономічну діяльність підприємств сировинної й переробної сфери. Зроблено висновок, у якому виділені конкретні заходи, що сприяють стабілізації інвестиційного клімату в Росії.Financial and economic peculiarities of Russia's investment climate development while attracting foreign direct investments are revealed with the definition of real positive and negative influential reasons and factors. Factors that restrain qualitative promotion of foreign investments into Russian economy are reflected. Specific juridical violations which restrain full-fledged foreign economic activity of companies in raw-material and processing industry are defined. Conclusions where specific actions to support stabilisation of investment climate in Russia are provided