21,833 research outputs found
Cuntz-Pimsner C*-algebras associated with subshifts
By using C*-correspondences and Cuntz-Pimsner algebras, we associate to every
subshift (also called a shift space) a C*-algebra , which is a
generalization of the Cuntz-Krieger algebras. We show that is the
universal C*-algebra generated by partial isometries satisfying relations given
by . We also show that is a one-sided conjugacy invariant of .Comment: 28 pages. This is a slightly updated version of a preprint from 2004.
Submitted for publication. In version 2 the Introduction has been changed,
two remarks (Remark 7.6 and 7.7) have been added and the list of references
has been update
Modeling with structure of resins in electonic compornents
In recent years, interfacial fracture becomes one of the most important
problems in the assessment of reliability of electronics packaging. Especially,
underfill resin is used with solder joints in flip chip packaging for
preventing the thermal fatigue fracture in solder joints. In general, the
interfacial strength has been evaluated on the basis of interfacial fracture
mechanics concept. However, as the size of devices decrease, it is difficult to
evaluate the interfacial strength quantitatively. Most of researches in the
interfacial fracture were conducted on the basis of the assumption of the
perfectly bonding condition though the interface has the micro-scale structure
and the bonding is often imperfect. In this study, the mechanical model of the
interfacial structure of resin in electronic components was proposed.
Bimaterial model with the imperfect bonding condition was examined by using a
finite element analysis (FEA). Stress field in the vicinity of interface
depends on the interfacial structure with the imperfect bonding. In the front
of interfacial crack tip, the behavior of process zone is affected by
interfacial structure. However, the instability of fracture for macroscopic
crack which means the fracture toughness is governed by the stress intensity
factor based on the fracture mechanics concept.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Description of Four-Body Breakup Reaction with the Method of Continuum-Discretized Coupled-Channels
We present a method for smoothing discrete breakup -matrix elements
calculated by the method of continuum-discretized coupled-channels (CDCC). This
smoothing method makes it possible to apply CDCC to four-body breakup
reactions. The reliability of the smoothing method is confirmed for two cases,
Ni(, ) at 80 MeV and the transition of He. We apply
CDCC with the smoothing method to He breakup reaction at 22.5 MeV.
Multi-step breakup processes are found to be important.Comment: 19 pages, 7 figures, published in Progress of Theoretical Physic
Evaluation of scanning earth sensor mechanism on engineering test satellite 4
The results of the analysis and the evaluation of flight data obtained from the horizon sensor test project are described. The rotary mechanism of the scanning earth sensor composed of direct drive motor and bearings using solid lubricant is operated satisfactorily. The transmitted flight data from Engineering Test Satellite IV was evaluated in comparison with the design value
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