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101.
Sylvain Durand Anne-Marie Alt Nicolas Marchand 《International journal of systems science》2013,44(8):1432-1446
Embedded devices using highly integrated chips must cope with conflicting constraints, while executing computationally demanding applications under limited energy storage. Automatic control and feedback loops appear to be an effective solution to simultaneously accommodate for performance uncertainties due to the tiny scale gates variability, varying and poorly predictable computing demands and limited energy storage constraints. This paper presents the example of an embedded video decoder controlled by several feedback loops to carry out the trade-off between decoding quality and energy consumption, exploiting the frequency and voltage scaling capabilities of the chip. The inner loop controls the dynamic voltage and frequency scaling through a fast predictive control strategy. The outer loop computes the scheduling set-points needed by the inner loop to process frames decoding. The feedback loops have been implemented on a stock PC and experimental results are provided. 相似文献
102.
103.
A two-port memory contains two duplicated sets of address decoders, which operate independently. Testing such memories requires the use of single-port tests as well as special two-port tests; the test strategy determines which tests have to be used. Many two-port memories have ports which are read-only or write-only; this impacts the possible tests for single-port and two-port memories, as well as the test strategy. In this paper the effects of interference and shorts between the address decoders of the two ports on the fault modeling are investigated. Fault models and their tests are introduced. In addition, the consequences of the port restrictions (read-only or write-only ports) on the fault models and tests are discussed, together with the test strategy. 相似文献
104.
105.
The protection of financial information has always been critical to success in banking. Security has become much more visible now that the automation and interconnection of banking processes is becoming widespread. Most financial institution are moving towards international systems interworkng, eventually using products based on the Open Systems Interconnection model. Thus, it is essential that basic security services be incorporated into the OSI architecture. This paper reviews security needs for banking communications, surveys on-going standardization work in TC68 (Banking) and TC97/SC21, and concludes that the planned security services in OSI should satisfy banking requirements if completed quickly. 相似文献
106.
Extraction of a metal ion from its oxide using ligand assisted supercritical carbon dioxide (SC CO2) comprises namely ionisation of metal oxide, in-situ chelation of metal cation with the ligand to form metal chelate/adduct and subsequently its extraction. Understanding of the mass transfer of chelate/adduct is very important in deciding the overall performance of the in-situ supercritical fluid extraction (ISCFE) process. For the present study neodymium (Nd) is selected as a model metal ion for its extraction from oxide using a mixed ligand system containing thenoyl tri-fluoroacetone (TTA) and tri-butylphosphate (TBP). Extraction studies have been performed at 35 MPa and 60°C for the prepared Nd-TTA-TBP adduct as well as for neodymium oxide (Nd2O3). The rate of dissolution starting from oxide and TTA-TBP adduct of Nd have been calculated and compared with the equilibrium values based on dissolution studies at the same conditions of temperature and pressure. During the extraction starting from oxide, the ligands TTA and TBP are also co-extracted with the adduct as these are highly soluble in SC CO2. Mass transfer coefficient has also been estimated for the steady state during the dynamic extraction. It is observed that the rate of extraction and mass transfer coefficient increase with flow rate of SC CO2. 相似文献
107.
This article proposes a multistage soft decision equalization (SDE) technique for block transmission over frequency selective multi-input multi-output (MIMO) channels. Using the Toeplitz structure, the general signal model can be converted into a series of small-sized sub-signal models. For each sub-signal model, soft interference cancellation (SIC) is used firstly to remove partial effects of interfering symbols, then max-log-map sphere decoder is performed to get the desired a posteriori information. Simulation shows that with lower complexity the proposed method outperforms the probability data association SDE and the Schnorr-Euchner sphere decoder. 相似文献
108.
Jasmin A. Mahal T. Charles Clancy 《Wireless Communications and Mobile Computing》2016,16(15):2315-2328
In this paper, the authors derived the analytical bit error rate expressions for orthogonal frequency division multiple access and single‐carrier frequency‐division multiple access (SC‐FDMA) in Rayleigh slow‐fading channel for binary phase‐shift keying/quadrature phase‐shift keying/16‐quadrature amplitude modulations under pilot jamming and pilot symbol‐assisted channel estimation. Beginning with the bit error rate analysis from the general case of pilot symbol‐assisted channel estimation technique in Rayleigh slow‐fading channel, the expressions are first modified for different modulations and then further customized to account for the Zero‐Forcing equalization in frequency or time direction with application respectively to orthogonal frequency division multiple access or SC‐FDMA without and with pilot jamming. Piecewise‐linear interpolation is used for its simplicity. The simulation results match perfectly with the theoretical predictions except for some discrepancies with SC‐FDMA, which imply that the generalized equations developed here have to be further modified to account for system‐specific features like discrete Fourier transform precoding for SC‐FDMA. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
109.
Amnart Boonkajay Fumiyuki Adachi 《Wireless Communications and Mobile Computing》2016,16(16):2509-2522
Single‐carrier transmission with frequency‐domain equalization (SC‐FDE) is widely known as a promising transmission technique providing low error probability with low peak‐to‐average power ratio (PAPR) of transmit signal. However, the low‐PAPR property of SC‐FDE cannot be maintained if multi‐level data modulation is introduced. The low‐PAPR property of SC‐FDE can be maintained by applying transmit filtering with roll‐off factor at the expense of spectrum efficiency. In this paper, we propose two types of selected mapping (SLM) to reduce the PAPR of SC‐FDE transmit signal. The first SLM technique is conducted in the frequency domain, where the phase rotation is applied to subcarriers similar to the SLM technique for orthogonal frequency division multiplexing transmission. The second SLM technique is conducted in the time domain, where the phase rotation is applied directly to data‐modulated symbol sequence. Computer simulation confirms that both SLM techniques are able to reduce the PAPR of SC‐FDE signal without significant degradation of bit‐error rate performance and spectrum efficiency. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
110.
温室盆栽法测定除草活性试验结果表明,380g/L噁草酮悬浮剂及其不同桶混助剂配伍对水稻稗草有较好的除草活性,特别是加入桶混助剂GY—Hba S2#的380g/L噁草酮悬浮剂在试验中产生较显著的增效作用。 相似文献