Study on Vibration Attenuation Element Using Damping Polyurethane Gel Material

2012 ◽  
Author(s):  
Osamu Furuya ◽  
Kengo Goda ◽  
Kenta Ishihana
Keyword(s):  
Large Scale ◽  
Development Stage ◽  
Control Device ◽  
Scale Structure ◽  
Response Control ◽  
Seismic Safety ◽  
Spring Element ◽  
Structural Rigidity ◽  
Detached House ◽  
Small Structure

The seismic safety should be constantly considered for mechanical, architectural and civil structures in Japan where is one of severe quake-prone countries in the world. The aseismic construction, seismically isolated structure and response control structure have been applied to the several structures for upgrading of seismic safety, and then the design technique for large scale structure in the current situation is close to standard range in recent years. However, the quake-proof technique for the smaller scale structure such as a detached house, server rack and art and craft has not yet been in the development stage until now, and especially there is a problem in the damping element in the practical use stage because the downsizing of damping element is often difficult to be adapted to design specification such as a performance, a cost, a mechanism and so on for comparatively small structure. In this study, the urethane material has been developed to use as a damping element in the response control device. The newly urethane gel material is compounded to become the characteristic that a spring element in the material to minimize the effect against the structural rigidity. This paper describes the efficiency of newly developed urethane gel material as a damping element is considered from several material characteristic evaluations and basic mechanical characteristic investigations.

Study on Simple Vibration Attenuation System for Light Weight Structure

2007 ◽  
Author(s):  
Osamu Furuya ◽  
Hiroshi Kurabayashi
Keyword(s):  
Large Scale ◽  
Base Isolation ◽  
Scale Structure ◽  
Small Scale ◽  
Response Analysis ◽  
Light Weight ◽  
Seismic Safety ◽  
Small Scale Structure ◽  
Vibration Attenuation ◽  
Weight Structure

Various vibration attenuation methods such as a base isolation and vibration control are suggested as seismic safety technique for large scale architectural and civil structure, and these methods have been practical used now. In recent years, these vibration reduction technology begins to be applied to a small scale structure. In case that the technology is applied to a small scale structure, specifications and a cost of the device must be examined well. In this study, a vibration attenuation system for light weight structure with low cost and simple mechanizm. This paper describes the effectiveness of the proposed vibration attenuation system which was evaluated from preliminary seismic response analysis.

Zeitstrukturen im Jazz

2014 ◽  
Vol 59 (1) ◽  
pp. 79-92
Author(s):  
Alexander Becker
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Time Frame ◽  
Scale Structure ◽  
Classical Form ◽  
Jazz Music ◽  
The Moment

Wie erlebt der Hörer Jazz? Bei dieser Frage geht es unter anderem um die Art und Weise, wie Jazz die Zeit des Hörens gestaltet. Ein an klassischer Musik geschultes Ohr erwartet von musikalischer Zeitgestaltung, den zeitlichen Rahmen, der durch Anfang und Ende gesetzt ist, von innen heraus zu strukturieren und neu zu konstituieren. Doch das ist keine Erwartung, die dem Jazz gerecht wird. Im Jazz wird der Moment nicht im Hinblick auf ein Ziel gestaltet, das von einer übergeordneten Struktur bereitgestellt wird, sondern so, dass er den Bewegungsimpuls zum nächsten Moment weiterträgt. Wie wirkt sich dieses Prinzip der Zeitgestaltung auf die musikalische Form im Großen aus? Der Aufsatz untersucht diese Frage anhand von Beispielen, an denen sich der Weg der Transformation von einer klassischen zu einer dem Jazz angemessenen Form gut nachverfolgen lässt.<br><br>How do listeners experience Jazz? This is a question also about how Jazz music organizes the listening time. A classically educated listener expects a piece of music to structure, unify and thereby re-constitute the externally given time frame. Such an expectation is foreign to Jazz music which doesn’t relate the moment to a goal provided by a large scale structure. Rather, one moment is carried on to the next, preserving the stimulus potentially ad infinitum. How does such an organization of time affect the large scale form? The paper tries to answer this question by analyzing two examples which permit to trace the transformation of a classical form into a form germane to Jazz music.

scholarly journals Mapping large-scale-structure evolution over cosmic times

2021 ◽  
Author(s):  
Marta B. Silva ◽  
Ely D. Kovetz ◽  
Garrett K. Keating ◽  
Azadeh Moradinezhad Dizgah ◽  
Matthieu Bethermin ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Large Scale ◽  
High Redshift ◽  
Formation Rate ◽  
Far Infrared ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Structure Evolution ◽  
Intensity Mapping ◽  
Wide Range

AbstractThis paper outlines the science case for line-intensity mapping with a space-borne instrument targeting the sub-millimeter (microwaves) to the far-infrared (FIR) wavelength range. Our goal is to observe and characterize the large-scale structure in the Universe from present times to the high redshift Epoch of Reionization. This is essential to constrain the cosmology of our Universe and form a better understanding of various mechanisms that drive galaxy formation and evolution. The proposed frequency range would make it possible to probe important metal cooling lines such as [CII] up to very high redshift as well as a large number of rotational lines of the CO molecule. These can be used to trace molecular gas and dust evolution and constrain the buildup in both the cosmic star formation rate density and the cosmic infrared background (CIB). Moreover, surveys at the highest frequencies will detect FIR lines which are used as diagnostics of galaxies and AGN. Tomography of these lines over a wide redshift range will enable invaluable measurements of the cosmic expansion history at epochs inaccessible to other methods, competitive constraints on the parameters of the standard model of cosmology, and numerous tests of dark matter, dark energy, modified gravity and inflation. To reach these goals, large-scale structure must be mapped over a wide range in frequency to trace its time evolution and the surveyed area needs to be very large to beat cosmic variance. Only a space-borne mission can properly meet these requirements.

scholarly journals Higher order Hamiltonian Monte Carlo sampling for cosmological large-scale structure analysis

2021 ◽  
Vol 502 (3) ◽  
pp. 3976-3992
Author(s):  
Mónica Hernández-Sánchez ◽  
Francisco-Shu Kitaura ◽  
Metin Ata ◽  
Claudio Dalla Vecchia
Keyword(s):  
Fourth Order ◽  
Large Scale ◽  
Equations Of Motion ◽  
Large Scale Structure ◽  
Real Space ◽  
Higher Order ◽  
Second Order ◽  
Scale Structure ◽  
Integration Schemes ◽  
Reconstruction Methods

ABSTRACT We investigate higher order symplectic integration strategies within Bayesian cosmic density field reconstruction methods. In particular, we study the fourth-order discretization of Hamiltonian equations of motion (EoM). This is achieved by recursively applying the basic second-order leap-frog scheme (considering the single evaluation of the EoM) in a combination of even numbers of forward time integration steps with a single intermediate backward step. This largely reduces the number of evaluations and random gradient computations, as required in the usual second-order case for high-dimensional cases. We restrict this study to the lognormal-Poisson model, applied to a full volume halo catalogue in real space on a cubical mesh of 1250 h−1 Mpc side and 2563 cells. Hence, we neglect selection effects, redshift space distortions, and displacements. We note that those observational and cosmic evolution effects can be accounted for in subsequent Gibbs-sampling steps within the COSMIC BIRTH algorithm. We find that going from the usual second to fourth order in the leap-frog scheme shortens the burn-in phase by a factor of at least ∼30. This implies that 75–90 independent samples are obtained while the fastest second-order method converges. After convergence, the correlation lengths indicate an improvement factor of about 3.0 fewer gradient computations for meshes of 2563 cells. In the considered cosmological scenario, the traditional leap-frog scheme turns out to outperform higher order integration schemes only when considering lower dimensional problems, e.g. meshes with 643 cells. This gain in computational efficiency can help to go towards a full Bayesian analysis of the cosmological large-scale structure for upcoming galaxy surveys.

scholarly journals Abell Clusters as Tracers of Large-Scale Structure: Alignments and Substructure

1988 ◽  
Vol 130 ◽  
pp. 536-536
Author(s):  
G. Rhee ◽  
P. Katgert
Keyword(s):  
Structure Data ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Abell Clusters

Binggeli (A & A, 107, 338, 1982) showed that neighbouring Abell clusters with pair distances less than 30 to 40 h50−1 Mpc show directional correlation. Binggeli's result is based on structure data of 44 Abell clusters (all with zspectr < 0.1). Binggelli's result was questioned by Struble and Peebles (A.J., 90, 582, 1985). They produce a visual estimate of the direction of cluster elongation for 237 clusters. They did not observe reduced probability for small D large Θ pairs.

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