415 research outputs found
Dynamic microphones M-87/AIC and M-101/AIC and earphone H-143/AIC
The electrical characteristics of the M-87/AIC and M-101/AIC dynamic microphone and H-143 earphones were tested for the purpose of establishing the relative performance levels of units supplied by four vendors. The microphones and earphones were tested for frequency response, sensitivity, linearity, impedance and noise cancellation. Test results are presented and discussed
A multi-objective optimized service level agreement approach applied on a cloud computing ecosystem
The cloud ecosystem provides transformative advantages that allow elastically offering ondemand services. However, it is not always possible to provide adequate services to all customers and thus to fulfill service level agreements (SLA). To enable compliance with these agreements, service providers leave the customer responsible for determining the service settings and expect that the client knows what to do. Some studies address SLA compliance, but the existing works do not adequately address the problem of resource allocation according to clients’ needs since they consider a limited set of objectives to be analyzed
and fulfilled. In previous work, we have already addressed the problem considering a single-objective approach. In that work, we identified that the problem has a multi-objective characteristic since several attributes simultaneously influence the SLA agreement, which can lead to conflicts. This paper proposes a multi-objective combinatorial optimization approach for computational resources provisioning, seeking to optimize the efficient use of the infrastructure and provide the client with greater flexibility in contract closure.Toledo, Azevedo and Estrella had supported in part by CNPq, CAPES, and FAPESP (processes IDs: 15/11623-4 and 16/14219-2) and use of the computational resources of the Center for Mathematical Sciences Applied to Industry (CeMEAI) funded by FAPESP (grant 2013/07375-0
MeV magnetosheath ions energized at the bow shock
A causal relationship between midlatitude magnetosheath energetic ions and bow shock magnetic geometry was previously established for ion energy up to 200 keV e−1 for the May 4, 1998, storm event. This study demonstrates that magnetosheath ions with energies above 200 keV up to 1 MeV simply extend the ion spectrum to form a power law tail. Results of cross-correlation analysis suggest that these ions also come directly from the quasi-parallel bow shock, not the magnetosphere. This is confirmed by a comparison of energetic ion fluxes simultaneously measured in the magnetosheath and at the quasi-parallel bow shock when both regions are likely connected by the magnetic field lines. We suggest that ions are accelerated at the quasi-parallel bow shock to energies as high as 1 MeV and subsequently transported into the magnetosheath during this event
Part Variation Modeling to Avoid Scrap Parts in Multi-stage Production Systems
Manufacturing systems for today's products are complex systems requiring a variety of different processes in order to be able to manufacture all necessary part features. This also applies to the production of rotating components, which have experienced increasing demand at the latest due to the growth in mobility. As in almost every manufacturing process, quality-reducing defects can occur due to deviations for example tool wear, which cannot always be avoided. Those, that have accumulated from previous process steps can cause the occurrence of superimposed defects. This leads to complex relationships between quality defects in the end product and the numerous parameters of the manufacturing processes. To remain competitive, production must be optimized in order to identify defects as early as possible, as well as their dependencies and variation patterns. The paper presents an approach to identify and model part variations within multi-stage production systems. Subsequently, based on a detected deviation, a downstream compensation strategy can be proposed at an early stage of the manufacturing process, which uses the capability of the overall system to fundamentally eliminate rejects
A structured approach to VO reconfigurations through Policies
One of the strength of Virtual Organisations is their ability to dynamically
and rapidly adapt in response to changing environmental conditions. Dynamic
adaptability has been studied in other system areas as well and system
management through policies has crystallized itself as a very prominent
solution in system and network administration. However, these areas are often
concerned with very low-level technical aspects. Previous work on the APPEL
policy language has been aimed at dynamically adapting system behaviour to
satisfy end-user demands and - as part of STPOWLA - APPEL was used to adapt
workflow instances at runtime. In this paper we explore how the ideas of APPEL
and STPOWLA can be extended from workflows to the wider scope of Virtual
Organisations. We will use a Travel Booking VO as example.Comment: In Proceedings FAVO 2011, arXiv:1204.579
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