With the advent of portable and high density microelectronic devices, the minimization of power consumption in CMOS VLSI circuits is becoming a critical concern. An embedded system is a combination of electronic hardw...
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ISBN:
(纸本)9781479917808
With the advent of portable and high density microelectronic devices, the minimization of power consumption in CMOS VLSI circuits is becoming a critical concern. An embedded system is a combination of electronic hardware and software and sometimes additional parts designed to perform a dedicated function. In many cases system (microprocessor) must monitor the amount of power it uses and take appropriate steps to save the battery life. There are several methods to save power consumption of microprocessor unit including: clock control, power-sensitive processors, low-voltage and circuit shutdown. The effect of reducing power consumption can be achieved either by hardware or software optimization. This paper presents the software level power consumption analysis of MCU, focusing mainly on instruction and data realization.
Summary.. Shell Western E and P Inc. has installed pumpoff control on more than 2,500 sucker-rod pumping wells in the Permian Basin during the last 12 years. These systems fall into three basic categories: stand-alone...
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Summary.. Shell Western E and P Inc. has installed pumpoff control on more than 2,500 sucker-rod pumping wells in the Permian Basin during the last 12 years. These systems fall into three basic categories: stand-alone analog devices, stand-alone microprocessor units with optional communication capabilities to a central computer, and a centralized system where well data are communicated to a central computer for pumpoff decisions. Evaluation has shown that production can be maintained or slightly increased while energy consumption and maintenance expense are substantially reduced. The pumpoff controllers also provide well data that are beneficial in maintaining good ***. Sucker-rod pumping is by far the predominant artificial lift method used in the U.S. for producing oil wells. Published data indicate that more than 85% of the artificially lifted wells in the U.S. use sucker-rod pumping. Of new installations of artificial lift made in 1983 through 1986, more than 92% were sucker-rod pumping. Rod pumping is popular because of its simplicity, ruggedness, and ability pumping is popular because of its simplicity, ruggedness, and ability to cover a wide range of producing conditions. Rod pumping is usually the artificial lift method selected, except where the volumes to be lifted exceed its capability or where surface conditions preclude its *** problem in design is to select a pumping installation that will obtain all the production economically available from the well while minimizing the capital expenditure required for lift equipment. If the pump capacity is less than the well's ability to produce, the well will not be produced at its maximum rate of production. On the other hand, if more pump capacity is provided than well capacity, the well will be overpumped and a pumped-off or fluid-pound condition will occur. When the liquid production from the well is inadequate to fill the pump barrel completely on each suction stroke, the barrel will
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