Carleton University

About: Carleton University is a education organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 15852 authors who have published 39650 publications receiving 1106610 citations.

Operating systems for wireless sensor networks: a survey.

Abstract: This paper presents a survey on the current state-of-the-art in Wireless Sensor Network (WSN) Operating Systems (OSs). In recent years, WSNs have received tremendous attention in the research community, with applications in battlefields, industrial process monitoring, home automation, and environmental monitoring, to name but a few. A WSN is a highly dynamic network because nodes die due to severe environmental conditions and battery power depletion. Furthermore, a WSN is composed of miniaturized motes equipped with scarce resources e.g., limited memory and computational abilities. WSNs invariably operate in an unattended mode and in many scenarios it is impossible to replace sensor motes after deployment, therefore a fundamental objective is to optimize the sensor motes’ life time. These characteristics of WSNs impose additional challenges on OS design for WSN, and consequently, OS design for WSN deviates from traditional OS design. The purpose of this survey is to highlight major concerns pertaining to OS design in WSNs and to point out strengths and weaknesses of contemporary OSs for WSNs, keeping in mind the requirements of emerging WSN applications. The state-of-the-art in operating systems for WSNs has been examined in terms of the OS Architecture, Programming Model, Scheduling, Memory Management and Protection, Communication Protocols, Resource Sharing, Support for Real-Time Applications, and additional features. These features are surveyed for both real-time and non-real-time WSN operating systems.

Airborne Communication Networks: A Survey

Abstract: Owing to the explosive growth of requirements of rapid emergency communication response and accurate observation services, airborne communication networks (ACNs) have received much attention from both industry and academia. ACNs are subject to heterogeneous networks that are engineered to utilize satellites, high-altitude platforms (HAPs), and low-altitude platforms (LAPs) to build communication access platforms. Compared to terrestrial wireless networks, ACNs are characterized by frequently changed network topologies and more vulnerable communication connections. Furthermore, ACNs have the demand for the seamless integration of heterogeneous networks such that the network quality-of-service (QoS) can be improved. Thus, designing mechanisms and protocols for ACNs poses many challenges. To solve these challenges, extensive research has been conducted. The objective of this special issue is to disseminate the contributions in the field of ACNs. To present this special issue with the necessary background and offer an overall view of this field, three key areas of ACNs are covered. Specifically, this paper covers LAP-based communication networks, HAP-based communication networks, and integrated ACNs. For each area, this paper addresses the particular issues and reviews major mechanisms. This paper also points out future research directions and challenges.

Gaming the Quantified Self

Abstract: By their nature, digital games facilitate surveillance. They allow for the compilation of statistics, internal states, and rules to be recorded, thus hiding many of the internal workings from the players and making the games much more complex. This digitization makes it much easier to collect player data and metrics, and then, as a process of function creep, to use this data in new and innovative ways, such as improving the user experience, or subtly shaping users' in-game desires and behaviours. Increasingly, these practices have moved from non-game spaces into social networking sites and spaces of play. The "gamification" movement is benefiting from the increasing sophistication of such metrics. Gamification combines the playful design and feedback mechanisms from games with users' social profiles (e.g. Facebook, twitter, and LinkedIn) in non-game applications explicitly geared to drive behavioural change (e.g. weight loss, workplace productivity, educational tools, and consumer loyalty). As critics point out, gamified applications rely on the points, leaderboards, and badges often seen in games, but are not games in themselves (Deterding 2010; Bogost 2011). Advocates of the gamification movement - including Al Gore in a recent Games for Change keynote - argue that this monitoring and feedback makes difficult tasks more playful and enjoyable (McGonigal 2011; Gore 2011) . However, the marketing and political discourse of using games to change behaviour in positive ways is quite different from messy actualities rooted in advertising, consumption, and intrusive user monitoring. The current potentials to ‘gamify’ life have incited debate on whether the spread of these points based systems heralds playful utopias or dystopic surveillant societies run by corporations and advertisers. This paper highlights the rise of gamification and the implications for surveillance studies. In particular, it focuses on describing the increasingly intrusive monitoring practices are propagated under the banner of fun and play.

Optical Centrifuge for Molecules

Abstract: Strong infrared fields can be used for controlled spinning of molecules to very high angular momentum states. The angular momentum acquired can be sufficient to break molecular bonds. The approach is suitable for all anisotropic molecules, and we illustrate it by dissociating a homonuclear diatomic Cl2, with optical centrifuge efficiently separating Cl 35 and Cl 37 isotopes and thus demonstrating high sensitivity to the moment of inertia. [S0031-9007(99)09026-2] PACS numbers: 33.80.Rv, 82.50.Fv Optical manipulation of atoms (trapping, cooling, acceleration) has grown into a well-developed and established field. Its successful use of resonant processes is difficult to mimic for manipulation of molecules, due to the complexity of molecular energy spectra. However, intense nonresonant fields can provide forces similar to or even stronger than the resonant weak fields used in atom optics. Nonresonant forces have been long utilized in the manipulation of microscopic particles [1,2] but were only recently demonstrated for molecules, in optical deflection [3] and trapping [4] experiments. Molecular optics has a rich potential due to additional degrees of freedom offered by molecules. A range of molecular optics devices has been proposed [5] to control the external degrees of freedom using strong fields, while the field of coherent (or, more generally, active) control has been exploring ways to control the internal degrees of freedom [6]. We propose to use a nonresonant strong field to exert large optical torques on anisotropic molecules, leading to controlled molecular rotations induced with a simple pulse. This follows the work on strong field alignment [7] and complements the application of feedback control methods [8] to optimally excite specific angular momentum states. Molecular dissociation via rotations is used to demonstrate our method. The scheme distinguishes between molecules based on their moment of inertia, and thus acts as an optical centrifuge. An anisotropic molecule placed in a linearly polarized infrared laser field experiences a time-averaged (over the laser cycle) potential 2U0 cos 2 u due to the induced dipole moment interacting with the electric field. Here u is the angle between laser polarization and molecular axis, and U0 › s1y4 ds a k 2a ’ d E 2 , with E the field amplitude and ak and a’ the polarizability components parallel and perpendicular to the molecular axis [7]. Oblong molecules have ak .a ’ and align with the electric field. For most diatomics, U0 , 30 100 meV can be achieved before ionization becomes important on the nanosecond time scale [3]. Imagine now slowly rotating the polarization of the infrared field about a fixed axis —the molecule will follow and rotate with the same angular frequency. Accelerating the rotation of the polarization will increase the molecule’s angular momentum in a controlled manner. This rotation results in large centrifugal forces which can distort or even break the molecular bonds, including those in homonuclear diatomics which do not readily absorb in the infrared. The slowly rotating potential is produced by the field $ E › E0 cosvt f ˆ x cosfLstd 1 ˆ

Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider

Abstract: Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these long-lived particles (LLPs) can decay far from the interaction vertex of the primary proton–proton collision. Such LLP signatures are distinct from those of promptly decaying particles that are targeted by the majority of searches for new physics at the LHC, often requiring customized techniques to identify, for example, significantly displaced decay vertices, tracks with atypical properties, and short track segments. Given their non-standard nature, a comprehensive overview of LLP signatures at the LHC is beneficial to ensure that possible avenues of the discovery of new physics are not overlooked. Here we report on the joint work of a community of theorists and experimentalists with the ATLAS, CMS, and LHCb experiments—as well as those working on dedicated experiments such as MoEDAL, milliQan, MATHUSLA, CODEX-b, and FASER—to survey the current state of LLP searches at the LHC, and to chart a path for the development of LLP searches into the future, both in the upcoming Run 3 and at the high-luminosity LHC. The work is organized around the current and future potential capabilities of LHC experiments to generally discover new LLPs, and takes a signature-based approach to surveying classes of models that give rise to LLPs rather than emphasizing any particular theory motivation. We develop a set of simplified models; assess the coverage of current searches; document known, often unexpected backgrounds; explore the capabilities of proposed detector upgrades; provide recommendations for the presentation of search results; and look towards the newest frontiers, namely high-multiplicity 'dark showers', highlighting opportunities for expanding the LHC reach for these signals.