Cloud computing has emerged as one of the most highly discussed topics both in the academic community and in the computing industry. While most of the work that has been conducted to explore this field focuses either on establishing the basis for cloud computing or almost exclusively on the issues surrounding security and data privacy, this paper takes the first exploratory step into exploring the actual internal working of cloud computing and demonstrates its viability for organizations, more specifically educational establishments . The paper starts by introducing the most important key clouds computing concepts, including virtualization technologies, Web services and Service Oriented Architectures (SOA), and distributed computing. Light will be then shed on the impact and potential benefits of cloud computing on teaching and learning in educational institutions. The paper closes by describing building a private cloud inside educational institution and highlights its offerings for students, staff and lecturers. 相似文献
This paper introduces a Transimpedance Amplifier (TIA) design capable of producing an incremental input resistance in the ohmic range, for input signals in the microampere range, such as are encountered in the design of instrumentation for electrochemical ampero-metric sensors, optical-sensing and current-mode circuits. This low input-resistance is achieved using an input stage incorporating negative feedback. In a Cadence simulation of an exemplary design using a 180 nm CMOS process and operating with?±?1.8 V supply rails, the input resistance is 1.05 ohms and the power dissipation is 93.6 µW. The bandwidth, for a gain of 100 dBohm, exceeded 9 MHz. For a 1µA, 1 MHz sinusoidal input signal the Total Harmonic Distortion, with this gain, is less than 1%. The input referred noise current with zero photodiode capacitance is 2.09 pA/√Hz and with a photodiode capacitance of 2pF is 8.52 pA/√Hz. Graphical data is presented to show the effect of a photodiode capacitance varying from 0.5 to 2 pF, when the TIA is used in optical sensing. In summary, the required very low input resistance, at a low input current level (µA) is achieved and furthermore a Table is included comparing the characteristics and a widely used Figure of Merit (FOM) for the proposed TIA and similar published low-power TIAs. It is apparent from the Table that the FOM of the proposed TIA is better than the FOMs of the other TIAs mentioned.
Ralstonia eutropha was able to degrade p-nitrophenol (PNP) at concentrations ranging from 5 to 15mg l?1 in the presence of phenol which was kept at the constant concentration of 200 mg l?1. More than 90% of phenol was degraded within 30 h and in the absence of PNP. While in this time period and in the presence of 15 mg l?1 less than 30% of phenol was degraded and PNP removal ability of the test bacterium was about 20%. Kissiris as a natural source of silicon dioxide having a very rigid structure with many micropores irregularly distributed throughout its surface was used to evaluate effectiveness of the cell immobilization using a Kissiris-immobilized cell bioreactor [ICB]. By applying phenol-feeding regime in the ICB operated in a batch recycling mode, simultaneous degradation of phenol in total amount of 1,000 mg l?1 with 15 mg l?1 PNP was achieved within 40 h. 相似文献
Witnessing a substantial growth rate in its scientific production, Iran is considered as one of the recently rising stars in scientific contribution scene. However, its impact in science progress is widely unknown, especially at global level. Studying Iran’s scholarly publications and recognition in SCI, the present communication tries to clarify the country’s science system performance using regression analyses and then to compare its performance to that of the world, using Relative Citation Rate (RCR) and Relative Subfield Citedness (RW). The results of the regression analyses reveal that although Iran displays considerable weaknesses in its performance, it is increasingly recognized as its outputs grow. According to the RCR values, Iran performed at/above the global level in 21 subfields. However, the RW values show that the country’s performance is above the global level in only two subfields. Although Iran is very far from an ideal situation; these evidences can be considered as heralds of a successful movement towards a wealthy scientific future. 相似文献
In this paper, we present a self-tuning multi-objective framework for geometric programming that provides a fine trade-off between the competing objectives. The significance of this framework is that the designer does not need to perform any tuning of weights of objectives. The proposed framework is applied to gate sizing and clock network buffer sizing problems. In gate sizing application, power consumption is reduced on average by 86% while delay sees only an increase of 34 ns. In clock network butter sizing application, our framework results in a significant reduction in power, 57%, and an improvement of 31 ps in skew. 相似文献
Summary Based on the functional thermoviscoelastic model developed by the authors in the preceding paper of this issue, energy balances are drawn up (dissipation vs internal work production) for a material under thermomechanical loading. By classifying the thermomechanical processes involved, we show how delayed phenomena can appear on the energy balance for processes ending with an equilibrium state. Under cyclic loading, the characteristics of the energy phenomena are found to differ between the transient period and the established periodic mode. Lastly in the case of a null trace strain, methods of modelling the relaxation kernels are proposed with which it is possible to draw up energy balances of the kind using mechanical data. 相似文献