911 research outputs found

    Energy-Efficient Considerations on a Variable-Bitrate PCI-Express Device

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    Dynamic power management has been adopted in many systems to reduce the power/energy consumption by changing the system state dynamically. This paper explores energy efficiency for systems equipped with PCI-Express devices, which are designed for low power consumption and high performance, compared to corresponding PCI devices. We propose dynamic power management mechanism and a management policy for energy-efficient considerations. A case study for a variable-bit-rate local-area-network device under the PCI-Express specification is exploited to provide supports for dynamic packet transmission. Simulation results show that the proposed mechanism and policy would reduce the system energy consumption substantiall

    THE DESIGN MODEL OF MICRO END-MILLS MADE BY USING THE FINITE ELEMENT METHOD

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    The green processing technology has been brought to the focus of attention around the world. The development and application of green cutting depend on the machine and cutting tool technology progress, in so far as the development of cutting tool technology has quite a big influence. The study was focused on the simulation analysis model for micro milling SKD61 tool steel developed by the finite element method. First, because the impact of the effective rake angle on the oblique cutting model is equivalent to that of the rake angle on the orthogonal cut model, the complex tool geometry of an end-mill will be simplified to the orthogonal cutting model. Using the Taguchi method, the FEM simulation of orthogonal cutting operation was performed under different cutting speeds, cutting depths, effective rake angles and relief angles were modified. The cutting force, tool maximum temperature, tool maximum temperature and tip distance, and the contact length of tool and chip are the major performance indexes of micro milling process. Finally, the multiple cutting performance characteristic resulting from the grey relational analysis reveals that the influencing priority ranks for micro end-mills made of SKD61 tool steel are cutting speed, effective rake angle, relief angle, and cutting depth. The FEM model is suitable for simulating the cutting performance of micro cutting process, and can also be used as a design base for micro endmills

    Evaluating the Operational Efficiency of Life Insurance Companies in Taiwan– An Application of the Dynamic Network SBM Model

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    Using a Dynamic Network Slack-based Measurement model (Tone & Tsutsui, 2014), this study evaluated the operational efficiency of life insurance firms in Taiwan from 2006 to 2013. In contrast to previous research, we incorporated assets and liabilities management into the model and compared them against optimal efficiency values in order to determine whether firms are earning maximizing profit while ensuring long-term solvency. The life insurance industry in Taiwan has matured. We found that market competitiveness depends on firms size and business model. Financial holdings companies and large corporations are performing strongly, while small local firms and foreign-owned firms scored poorly in technical efficiency. Economies of scale contribute to the business performance of life insurance firms. Life insurance companies that had merged with or been acquired by financial holdings firms showed notable improvement in efficiency. However, change in term efficiency is a warning signal in long-term business performance of life insurance firms. Lastly, most companies achieved optimal carry-over efficiency, indicating that they place considerable emphasis on managing assets and liabilities in order to ensure future solvency

    Absorption Cross Sections of NH_3, NH_2D, NHD_2, and ND_3 in the Spectral Range 140-220 nm and Implications for Planetary Isotopic Fractionation

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    Cross sections for photoabsorption of NH_3, NH_2D, NHD_2, and ND_3 in the spectral region 140-220 nm were determined at ~298 K using synchrotron radiation. Absorption spectra of NH_2D and NHD_2 were deduced from spectra of mixtures of NH_3 and ND_3, of which the equilibrium concentrations for all four isotopologues obey statistical distributions. Cross sections of NH_2D, NHD_2, and ND_3 are new. Oscillator strengths, an integration of absorption cross sections over the spectral lines, for both A ← X and B ← X systems of NH_3 agree satisfactorily with previous reports; values for NH_2D, NHD_2, and ND_3 agree with quantum chemical predictions. The photolysis of NH_3 provides a major source of reactive hydrogen in the lower stratosphere and upper troposphere of giant planets such as Jupiter. Incorporating the measured photoabsorption cross sections of NH_3 and NH_2D into the Caltech/JPL photochemical diffusive model for the atmosphere of Jupiter, we find that the photolysis efficiency of NH_2D is lower than that of NH_3 by as much as 30%. The D/H ratio in NH_2D/NH_3 for tracing the microphysics in the troposphere of Jupiter is also discussed
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