scholarly journals Managing contamination delay to improve Timing Speculation architectures

Author(s):  
Naga Durga Prasad Avirneni ◽  
Prem Kumar Ramesh ◽  
Arun K Somani

Timing Speculation (TS) is a widely known method for realizing better-than-worst-case systems. Aggressive clocking, realizable by TS, enable systems to operate beyond specified safe frequency limits to effectively exploit the data dependent circuit delay. However, the range of aggressive clocking for performance enhancement under TS is restricted by short paths. In this paper, we show that increasing the lengths of short paths of the circuit increases the effectiveness of TS, leading to performance improvement. Also, we propose an algorithm to efficiently add delay buffers to selected short paths while keeping down the area penalty. We present our algorithm results for ISCAS-85 suite and show that it is possible to increase the circuit contamination delay by up to 30% without affecting the propagation delay. We also explore the possibility of increasing short path delays further by relaxing the constraint on propagation delay and analyze the performance impact.

2016 ◽  
Vol 2 ◽  
pp. e79 ◽  
Author(s):  
Naga Durga Prasad Avirneni ◽  
Prem Kumar Ramesh ◽  
Arun K. Somani

Timing Speculation (TS) is a widely known method for realizing better-than-worst-case systems. Aggressive clocking, realizable by TS, enable systems to operate beyond specified safe frequency limits to effectively exploit the data dependent circuit delay. However, the range of aggressive clocking for performance enhancement under TS is restricted by short paths. In this paper, we show that increasing the lengths of short paths of the circuit increases the effectiveness of TS, leading to performance improvement. Also, we propose an algorithm to efficiently add delay buffers to selected short paths while keeping down the area penalty. We present our algorithm results for ISCAS-85 suite and show that it is possible to increase the circuit contamination delay by up to 30% without affecting the propagation delay. We also explore the possibility of increasing short path delays further by relaxing the constraint on propagation delay and analyze the performance impact.


2016 ◽  
Author(s):  
Naga Durga Prasad Avirneni ◽  
Prem Kumar Ramesh ◽  
Arun K Somani

Timing Speculation (TS) is a widely known method for realizing better-than-worst-case systems. Aggressive clocking, realizable by TS, enable systems to operate beyond specified safe frequency limits to effectively exploit the data dependent circuit delay. However, the range of aggressive clocking for performance enhancement under TS is restricted by short paths. In this paper, we show that increasing the lengths of short paths of the circuit increases the effectiveness of TS, leading to performance improvement. Also, we propose an algorithm to efficiently add delay buffers to selected short paths while keeping down the area penalty. We present our algorithm results for ISCAS-85 suite and show that it is possible to increase the circuit contamination delay by up to 30% without affecting the propagation delay. We also explore the possibility of increasing short path delays further by relaxing the constraint on propagation delay and analyze the performance impact.


2015 ◽  
Author(s):  
Naga Durga Prasad Avirneni ◽  
Prem Kumar Ramesh ◽  
Arun K Somani

Timing Speculation (TS) is a widely known method for realizing better-than-worst-case systems. Aggressive clocking, realizable by TS, enable systems to operate beyond specified safe frequency limits to effectively exploit the data dependent circuit delay. However, the range of aggressive clocking for performance enhancement under TS is restricted by short paths. In this paper, we show that increasing the lengths of short paths of the circuit increases the effectiveness of TS, leading to performance improvement. Also, we propose an algorithm to efficiently add delay buffers to selected short paths while keeping down the area penalty. We present our algorithm results for ISCAS-85 suite and show that it is possible to increase the circuit contamination delay by up to 30% without affecting the propagation delay. We also explore the possibility of increasing short path delays further by relaxing the constraint on propagation delay and analyze the performance impact.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rajat Kumar Giri

Abstract In this paper, a hybrid-subcarrier-intensity-modulation (hybrid-SIM) technique for the performance improvement of free-space-optical (FSO) communication system has been proposed. Subsequently, for further error performance improvement, avalanche photodiode (APD) based receiver is used in the proposed system. The system performance is analyzed at various atmospheric turbulence levels over weak and strong turbulence channels. The bit error rate (BER) is theoretically derived using Gauss–Hermite approximation and Meijer-G function and it is simulated in the MATLAB environment. The simulation result shows that the BER performance of hybrid-SIM is better than BPSK-SIM technique irrespective of the channel types and also the significant BER performance improvement is observed by APD receiver.


Wireless sensor network incorporates an innovative aspect called as data handling technologies for big data organization. In today’s research the data aggregation occupies an important position and its emerging rapidly. Data aggregation incudes, process of accumulating the data at node, then either store or transfer further to reach out the destination. This survey depicts about the previous work on data aggregation in WSN and also its impact on the different services. There are number of data aggregation techniques available for reducing the data, processing the data and storing the data. Some of them are discussed here as a review. The data aggregation performed using certain techniques can also be aimed in having energy efficiency, time efficient, security could be in the form of confidentiality, unimpaired, authenticate, freshness, quality, data availability, access control, nonrepudiation, secrecy, secrecy. These are the relevant performance metrics to maintain the better Qos in WSNs applications. The goal of this paper is to display an overview of existing techniques for performance improvement in homogenous/ heterogenous networks.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Ramz L. Fraiha Lopes ◽  
Simone G. C. Fraiha ◽  
Vinicius D. Lima ◽  
Herminio S. Gomes ◽  
Gervásio P. S. Cavalcante

This study explores the use of a hybrid Autoregressive Integrated Moving Average (ARIMA) and Neural Network modelling for estimates of the electric field along vertical paths (buildings) close to Digital Television (DTV) transmitters. The work was carried out in Belém city, one of the most urbanized cities in the Brazilian Amazon and includes a case study of the application of this modelling within the subscenarios found in Belém. Its results were compared with the ITU recommendations P. 1546-5 and proved to be better in every subscenario analysed. In the worst case, the estimate of the model was approximately 65% better than that of the ITU. We also compared this modelling with a classic modelling technique: the Least Squares (LS) method. In most situations, the hybrid model achieved better results than the LS.


2017 ◽  
Vol 898 ◽  
pp. 334-344
Author(s):  
Ting Biao Guo ◽  
Feng Zhang ◽  
Qi Li ◽  
Chen Wang ◽  
Wan Wu Ding

As an important strengthening method, micro alloying has been widely used to improve the comprehensive properties of aluminum alloy. The research on microstructures and properties of Al-Cu-Mn alloy with Y, Zr and (Y, Zr) was conducted through OM, SEM and EDS methods. Three addition methods were comprehensively compared and the important significance of elements and relevant precipitates distribution to performance improvement was explored. The results show that adding different contents of Y, Zr and (Y, Zr) has great influence on microstructure and properties of Al-Cu-Mn alloy. Fluidity of the (Y+Zr)-containing alloy was significantly higher than that of the Zr or Y-containing one. The hardness and elongation of the Zr-containing alloy were also better than the other two groups, while with the increase of addition amounts from 0 to 0.2 %, it showed a decreasing trend. When the content was 0.3%, the grains of the Y and (Y+Zr)-containing alloys were well refined and the tensile strength and hardness increased as well, and Y-containing alloy presented the best tensile strength. After T6 heat treatment, the mechanical properties of the Y and (Zr+Y)-containing alloys were enhanced due to the dispersed θ phase and completely refined grains. And both ductile fracture ratios increased. When the content was more than 0.3%, the reticular θ phase formed that was extremely unfavorable to properties of the studied alloy. It appears that the addition of Y and Zr has an important influence on improving the properties of the Al-Cu-Mn alloy. And Y, Zr and (Y+Zr) dosages should be adjusted reasonably in the range of 0.1-0.3% to optimize and improve the alloy performance.


2012 ◽  
Vol 512-515 ◽  
pp. 1923-1926
Author(s):  
Zhuang Li ◽  
Di Wu ◽  
Wei Lv

Environmental protection is a growing concern for many industries today. This paper shows manufacturing environmental performance improvement for free cutting steel products. Inclusions have the characteristics of sulfur and bismuth in free cutting austenitic stainless steels without lead addition. Machinable additives lead to improved chip breakage, and thus reduced tool wear. The machinability of free cutting austenitic stainless steels without lead addition is much better than that of conventional austenitic stainless steel. Bismuth can replace lead because lead is a harmful factor for environment and machine operators' health. The reduction of environmentally harmful substances such as lead was performed. A feasible combination of free-cutting additives should yield a stainless steel product with acceptable machining and mechanical properties.


2010 ◽  
Vol 53 (2) ◽  
pp. 49-76 ◽  
Author(s):  
Hazel McFerson

Abstract:Twenty years ago, most African countries seemed permanently mired in malgovernance and repression. The end of the Cold War triggered two contrasting developments: governance improvement associated with the end of superpower competition, and deterioration caused by the resurgence of suppressed ethnic conflicts. Based on a variety of evidence, three subperiods can be identified: fragile governance progress from 1989 to 1995; backsliding associated largely with civil conflict between 1996 and 2002; and resumption of progress in recent years. These broad trends mask major intercountry differences—with Ghana the best-known case of improvement and Zimbabwe the worst case of reversal. Overall, African governance is now somewhat better than it was two decades ago. However, the progress is fragile, and improvements in administrative and economic governance have lagged behind those on the political front. Consolidating democracy will thus require institutional capacity building through a combination of appropriate civil society efforts and constructive external pressure to strengthen accountability.


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