"Third places" and social interaction in deprived neighbourhoods in Great Britain

This paper explores social interaction in local ‘public’ social spaces such as local shops, pubs, cafés, and community centres in deprived neighbourhoods. More specifically, it examines the importance, role and function of these places, which have been described by Oldenberg and Brissett (Qual Sociol 5(4):265–284, 1982), Oldenburg (Urban design reader. Architectural Place, Oxford, 2007) as being “third places” of social interaction after the home (first) and workplace (second). It does so by drawing on data gleaned from in-depth interviews with 180 residents in six deprived areas neighbourhoods across Great Britain, conducted as part of a study of the links between poverty and place funded by the Joseph Rowntree Foundation. The paper notes that local third places are an important medium for social interaction in these areas, although their importance appears to vary by population group. It notes that shops appear to be a particularly important social space. It also identifies some of the barriers to social interaction within third places and concludes by highlighting some of the key implications for policy to emerge from the research

Linearized Asymptotic Stability for Fractional Differential Equations

We prove the theorem of linearized asymptotic stability for fractional differential equations. More precisely, we show that an equilibrium of a nonlinear Caputo fractional differential equation is asymptotically stable if its linearization at the equilibrium is asymptotically stable. As a consequence we extend Lyapunov's first method to fractional differential equations by proving that if the spectrum of the linearization is contained in the sector \{\lambda \in \C : |\arg \lambda| > \frac{\alpha \pi}{2}\} where $\alpha > 0$ denotes the order of the fractional differential equation, then the equilibrium of the nonlinear fractional differential equation is asymptotically stable

The ARGUS Vertex Trigger

A fast second level trigger has been developed for the ARGUS experiment which recognizes tracks originating from the interaction region. The processor compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks stored in random access memories. The masks which are fully defined in three dimensions are able to reject tracks originating in the wall of the narrow beampipe of 10.5\,mm radius.Comment: gzipped Postscript, 27 page

Estimating the Yield Strength of Thin Metal Films through Elastic-Plastic Buckling-Induced Debonding

In this paper, we propose a procedure to estimate the yield strength of thin films by debonding films from their substrate by elastic-plastic buckling under thermally-induced compressive loading. The out-of-plane displacement of the metal lines under conditions of elastic-plastic buckling is dependent on the yield strength of the film. Thus, an inverse estimate of the yield strength is made from measurements of the out-of-plane displacements of the buckled metal lines. The procedure is demonstrated to estimate the yield strength of aluminum lines consistent with measurements by other techniques

An Efficient Network Model for Determining the Effective Thermal Conductivity of Particulate Thermal Interface Materials

Particulate composites are commonly used in Microelectronics applications. One example of such materials is Thermal Interface Materials (TIMs) that are used to reduce the contact resistance between the chip and the heat sink. The existing analytical descriptions of thermal transport in particulate systems do not accurately account for the effect of inter-particle interactions, especially in the intermediate volume fractions of 30-80%. Another crucial drawback in the existing analytical as well as the network models is the inability to model size distributions (typically bimodal) of the filler material particles that are obtained as a result of the material manufacturing process. While full-field simulations (using, for instance, the finite element method) are possible for such systems, they are computationally expensive. In the present paper, we develop an efficient network model that captures the physics of inter-particle interactions and allows for random size distributions. Twenty random microstructural arrangements each of Alumina as well as Silver particles in Silicone and Epoxy matrices were generated using an algorithm implemented using a java language code. The microstructures were evaluated through both full-field simulations as well as the network model. The full-field simulations were carried out using a novel meshless analysis technique developed in the author’s (GS) research [26]. In all cases, it is shown that the random network models are accurate to within 5% of the full field simulations. The random network model simulations were efficient since they required two orders of magnitude smaller computation time to complete in comparison to the full field simulation

Adaptive Mechanical Properties of Topologically Interlocking Material Systems

Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms

Optimal sequential fingerprinting: Wald vs. Tardos

We study sequential collusion-resistant fingerprinting, where the fingerprinting code is generated in advance but accusations may be made between rounds, and show that in this setting both the dynamic Tardos scheme and schemes building upon Wald's sequential probability ratio test (SPRT) are asymptotically optimal. We further compare these two approaches to sequential fingerprinting, highlighting differences between the two schemes. Based on these differences, we argue that Wald's scheme should in general be preferred over the dynamic Tardos scheme, even though both schemes have their merits. As a side result, we derive an optimal sequential group testing method for the classical model, which can easily be generalized to different group testing models.Comment: 12 pages, 10 figure

Balance task and head orientation dependency of vestibular reflexes in neck muscles

Human upright posture of both the head and body is facilitated by the CNS’s ability to integrate multiple sensory feedback signals, as well as its discernibility of the motor commands that maintain this stabilization. The vestibular organ in particular detects motion of the head-in-space, which is transformed according to on-going head and body orientation into appropriate motor responses. However, when motor commands do not contribute to the control of standing posture, and are incongruent with their expected sensory consequences, vestibulomuscular responses in the lower limb undergo unconscious suppression. In this study, we investigated whether vestibular response suppression occurs in neck muscles under conditions where the muscles are active but not engaged in a task to balance the head. In addition, we examined the effects of head orientation to identify spatial transformation of vestibular reflex responses. Eight subjects were exposed to stochastic vestibular stimulation (0-75 Hz) in a seated condition while their head was either free or fixed, and rotated at either 0 or 60°. In head-free conditions, subjects were asked to rotate their head 60° to the left in order to activate agonist neck muscle pairs (sternocleidomastoid - SCM and splenius capitis - SPL). In head-fixed conditions, subjects performed isometric neck muscle contractions in yaw at orientations of 0° and 60°, as well as flexion, extension and co-contraction at an orientation of 0°. Intramuscular EMG was collected bilaterally in SCM and SPL muscles. Muscle responses correlated to the input stimuli were significant (P < 0.05) for all conditions provided the muscle was used in contraction. Neither muscle underwent the expected vestibulomuscular suppression when not engaged in the balance task (i.e. head-fixed). Nevertheless, the magnitude of the SPL responses decreased by 22% when the head was fixed whereas SCM responses were unaffected. The effect of head fixation only in SPL suggests differences in neural pathways across muscles, possibly via alternative pathways known to exist in the SPL from the well-established monosynaptic vestibulospinal inputs in SCM and SPL. For both muscles, the effect of orientation and force direction had no effect on muscles responses. Since the stimulation is fixed relative to the head, the same muscles are activated to respond to the input stimulus at both orientations and all force directions. These results indicate that the vestibular pathways connecting neck muscles are less susceptible to suppression than lower limb muscles, most likely because the monosynaptic inputs innervating them are subject to less central control

Asymptotic properties of discrete linear fractional equations

In this paper we study the dynamical behavior of linear discrete-time fractional systems. The first main result is that the norm of the difference of two different solutions of a time-varying discrete-time Caputo equation tends to zero not faster than polynomially. The second main result is a complete description of the decay to zero of the trajectories of one-dimensional time-invariant stable Caputo and Riemann-Liouville equations. Moreover, we present Volterra convolution equations, that are equivalent to Caputo equations