Translatory shock absorber for attitude sensors

A translatory shock absorber is provided for mounting an attitude sensor thereon for isolating a sensor from translatory vibrations. The translatory shock absorber includes a hollow block structure formed as one piece to form a parallelogram. The absorber block structure includes a movable top plate for supporting the attitude sensor and a fixed base plate with opposed side plates interposed between. At the junctions of the side plates, and the base and top plates, there are provided grooves which act as flexible hinges for attenuating translatory vibrations. A damping material is supported on a pedestal which is carried on the base plate between the side plates thereof. The top of the damping material rests against the bottom surface of the top plate for eliminating the resonant peaks of vibration

Bio-linguistic transition and Baldwin effect in an evolutionary naming-game model

We examine an evolutionary naming-game model where communicating agents are equipped with an evolutionarily selected learning ability. Such a coupling of biological and linguistic ingredients results in an abrupt transition: upon a small change of a model control parameter a poorly communicating group of linguistically unskilled agents transforms into almost perfectly communicating group with large learning abilities. When learning ability is kept fixed, the transition appears to be continuous. Genetic imprinting of the learning abilities proceeds via Baldwin effect: initially unskilled communicating agents learn a language and that creates a niche in which there is an evolutionary pressure for the increase of learning ability.Our model suggests that when linguistic (or cultural) processes became intensive enough, a transition took place where both linguistic performance and biological endowment of our species experienced an abrupt change that perhaps triggered the rapid expansion of human civilization.Comment: 7 pages, minor changes, accepted in Int.J.Mod.Phys.C, proceedings of Max Born Symp. Wroclaw (Poland), Sept. 2007. Java applet is available at http://spin.amu.edu.pl/~lipowski/biolin.html or http://www.amu.edu.pl/~lipowski/biolin.htm

Failure assessment of lightly reinforced floor slabs. I: Experimental investigation

This paper is concerned with the ultimate behavior of lightly reinforced concrete floor slabs under extreme loading conditions. Particular emphasis is given to examining the failure conditions of idealized composite slabs which become lightly reinforced in a fire situation as a result of the early loss of the steel deck. An experimental study is described which focuses on the response of two-way spanning floor slabs with various materials and geometric configurations. The tests enable direct assessment of the influence of a number of key parameters such as the reinforcement type, properties, and ratio on the ultimate response. The results also permit the development of simplified expressions that capture the influence of salient factors such as bond characteristics and reinforcement properties for predicting the ductility of lightly reinforced floor slabs. The companion paper complements the experimental observations with detailed numerical assessments of the ultimate response and proposes analytical models that predict failure of slab members by either reinforcement fracture or compressive crushing of concrete. © 2011 American Society of Civil Engineers

Topological Optimization of the Evaluation of Finite Element Matrices

We present a topological framework for finding low-flop algorithms for evaluating element stiffness matrices associated with multilinear forms for finite element methods posed over straight-sided affine domains. This framework relies on phrasing the computation on each element as the contraction of each collection of reference element tensors with an element-specific geometric tensor. We then present a new concept of complexity-reducing relations that serve as distance relations between these reference element tensors. This notion sets up a graph-theoretic context in which we may find an optimized algorithm by computing a minimum spanning tree. We present experimental results for some common multilinear forms showing significant reductions in operation count and also discuss some efficient algorithms for building the graph we use for the optimization

Field Applications of Entomopathogenic Fungi \u3ci\u3eBeauveria bassiana\u3c/i\u3e and \u3ci\u3eMetarhizium anisopliae\u3c/i\u3e F52 (Hypocreales: Clavicipitaceae) for the Control of \u3ci\u3eIxodes scapularis\u3c/i\u3e (Acari: Ixodidae)

Two commercial formulations of Beauveria bassiana (Balsamo-Crivelli) Vuillemin were applied to residential sites in Old Lyme, CT, for the control of nymphs of the blacklegged tick, Ixodes scapularis, in 1999 and 2000. The pyrethroid bifenthrin was applied to other premises for comparison with B. bassiana. A wood chip barrier was installed and maintained at six of the treated properties. In 1999, control of I. scapularis nymphs ranged from 74.5 to 83.0% on lawns without wood chips and from 88.9 to 90% on lawns with wood chip barriers. As a control check, no ticks (n= 23) collected at pretreatment or control sites died from B. bassiana, although 15 of 18 nymphs from treated lawns developed mycoses. Control of I. scapularis on the lawns in 2000 with the two B. bassiana products was lower, as follows: 38.0 and 58.7% without the barrier and 56.9 and 55.1% with the wood chip barrier. Posttreatment differences in nymphal numbers between treatments and control were signiÞcant (P=0.005 and P=0.039, 1999 and 2000, respectively). The bifenthrin provided 86 and 87% control each year, respectively. The application of Metarhizium anisopliae (Metschnikoff) Sorokin strain F52 to 9 residential sites in Westport and Weston, CT, in 2002 provided significant (P = 0.034; P = 0.039) reductions in nymphal tick abundance with 55.6 and 84.6% fewer ticks on lawn and woodland plots, respectively. These results suggest the application of entomopathogenic fungi could provide another approach for the control of I. scapularis nymphs in residential or similar landscapes

Coupling Between Thermal Oscillations in the Surface of a Micro-Cylinder and Vortex Shedding

his article studies the coupling between prescribed thermal oscillations in the surface of a micro-cylinder and vortex shedding. We deal with the unsteady, laminar, compressible flow regime where the aerodynamics forces have a periodic behavior. It is shown that appropriate spatial and time-dependent temperature oscillations on the surface of the micro-cylinder create a resonance that controls the amplitude and frequency of both lift and drag coefficients. In practice, what we study is a mechanism to modulate the amplitude and frequency of mechanical loads of aerodynamics origin in a micro-structure by using surface temperature fluctuations as the control parameter

Attracted Diffusion-Limited Aggregation

In this paper, we present results of extensive Monte Carlo simulations of diffusion-limited aggregation (DLA) with a seed placed on an attractive plane as a simple model in connection with the electrical double layers. We compute the fractal dimension of the aggregated patterns as a function of the attraction strength \alpha. For the patterns grown in both two and three dimensions, the fractal dimension shows a significant dependence on the attraction strength for small values of \alpha, and approaches to that of the ordinary two-dimensional (2D) DLA in the limit of large \alpha. For non-attracting case with \alpha=1, our results in three dimensions reproduce the patterns of 3D ordinary DLA, while in two dimensions our model leads to formation of a compact cluster with dimension two. For intermediate \alpha, the 3D clusters have quasi-2D structure with a fractal dimension very close to that of the ordinary 2D-DLA. This allows one to control morphology of a growing cluster by tuning a single external parameter \alpha.Comment: 6 pages, 6 figures, to appear in Phys. Rev. E (2012