Systematic delay-driven power optimisation and power-driven delay optimisation of combinational circuits

With the proliferation of mobile wireless communication and embedded systems, the energy efficiency becomes a major design constraint. The dissipated energy is often referred as the product of power dissipation and the input-output delay. Most of electronic design automation techniques focus on optimising only one of these parameters either power or delay. Industry standard design flows integrate systematic methods of optimising either area or timing while for power consumption optimisation one often employs heuristics which are characteristic to a specific design. In this work we answer three questions in our quest to provide a systematic approach to joint power and delay Optimisation. The first question of our research is: How to build a design flow which incorporates academic and industry standard design flows for power optimisation? To address this question, we use a reference design flow provided by Synopsys and integrate in this flow academic tools and methodologies. The proposed design flow is used as a platform for analysing some novel algorithms and methodologies for optimisation in the context of digital circuits. The second question we answer is: Is possible to apply a systematic approach for power optimisation in the context of combinational digital circuits? The starting point is a selection of a suitable data structure which can easily incorporate information about delay, power, area and which then allows optimisation algorithms to be applied. In particular we address the implications of a systematic power optimisation methodologies and the potential degradation of other (often conflicting) parameters such as area or the delay of implementation. Finally, the third question which this thesis attempts to answer is: Is there a systematic approach for multi-objective optimisation of delay and power? A delay-driven power and power-driven delay optimisation is proposed in order to have balanced delay and power values. This implies that each power optimisation step is not only constrained by the decrease in power but also the increase in delay. Similarly, each delay optimisation step is not only governed with the decrease in delay but also the increase in power. The goal is to obtain multi-objective optimisation of digital circuits where the two conflicting objectives are power and delay. The logic synthesis and optimisation methodology is based on AND-Inverter Graphs (AIGs) which represent the functionality of the circuit. The switching activities and arrival times of circuit nodes are annotated onto an AND-Inverter Graph under the zero and a non-zero-delay model. We introduce then several reordering rules which are applied on the AIG nodes to minimise switching power or longest path delay of the circuit at the pre-technology mapping level. The academic Electronic Design Automation (EDA) tool ABC is used for the manipulation of AND-Inverter Graphs. We have implemented various combinatorial optimisation algorithms often used in Electronic Design Automation such as Simulated Annealing and Uniform Cost Search Algorithm. Simulated Annealing (SMA) is a probabilistic meta heuristic for the global optimization problem of locating a good approximation to the global optimum of a given function in a large search space. We used SMA to probabilistically decide between moving from one optimised solution to another such that the dynamic power is optimised under given delay constraints and the delay is optimised under given power constraints. A good approximation to the global optimum solution of energy constraint is obtained. Uniform Cost Search (UCS) is a tree search algorithm used for traversing or searching a weighted tree, tree structure, or graph. We have used Uniform Cost Search Algorithm to search within the AIG network, a specific AIG node order for the reordering rules application. After the reordering rules application, the AIG network is mapped to an AIG netlist using specific library cells. Our approach combines network re-structuring, AIG nodes reordering, dynamic power and longest path delay estimation and optimisation and finally technology mapping to an AIG netlist. A set of MCNC Benchmark circuits and large combinational circuits up to 100,000 gates have been used to validate our methodology. Comparisons for power and delay optimisation are made with the best synthesis scripts used in ABC. Reduction of 23% in power and 15% in delay with minimal overhead is achieved, compared to the best known ABC results. Also, our approach is also implemented on a number of processors with combinational and sequential components and significant savings are achieved

Unassisted selective solar hydrogen peroxide production by an oxidised buckypaper-integrated perovskite photocathode

Hydrogen peroxide (H2O2) is an eco-friendly oxidant and a promising energy source possessing comparable energy density to that of compressed H-2. The current H2O2 production strategies mostly depend on the anthraquinone oxidation process, which requires significant energy and numerous organic chemicals. Photocatalyst-based solar H2O2 production comprises single-step O-2 reduction to H2O2, which is a simple and eco-friendly method. However, the solar-to-H2O2 conversion efficiency is limited by the low performance of the inorganic semiconductor-based photoelectrodes and low selectivity and stability of the H2O2 production electrocatalyst. Herein, we demonstrate unassisted solar H2O2 production using an oxidised buckypaper as the H2O2 electrocatalyst combined with a high-performance inorganic-organic hybrid (perovskite) photocathode, without the need for additional bias or sacrificial agents. This integrated photoelectrode system shows 100% selectivity toward H2O2 and a solar-to-chemical conversion efficiency of similar to 1.463%

Bias-free solar hydrogen production at 19.8???mA???cm???2 using perovskite photocathode and lignocellulosic biomass

Solar hydrogen production is one of the ultimate technologies needed to realize a carbon-neutral, sustainable society. However, an energy-intensive water oxidation half-reaction together with the poor performance of conventional inorganic photocatalysts have been big hurdles for practical solar hydrogen production. Here we present a photoelectrochemical cell with a record high photocurrent density of 19.8???mA???cm???2 for hydrogen production by utilizing a high-performance organic???inorganic halide perovskite as a panchromatic absorber and lignocellulosic biomass as an alternative source of electrons working at lower potentials. In addition, value-added chemicals such as vanillin and acetovanillone are produced via the selective depolymerization of lignin in lignocellulosic biomass while cellulose remains close to intact for further utilization. This study paves the way to improve solar hydrogen productivity and simultaneously realize the effective use of lignocellulosic biomass

Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017 : A systematic analysis for the global burden of disease study

Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-Adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care. © 2019 American Medical Association. All rights reserved.Peer reviewe

Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study

18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016

Single-pion photoproduction in a model of higher baryon couplings

Pion photoproduction off nucleons via s-channel resonances up to a total c.m. energy of &#732; 2 GeV, and also the electromagnetic decay widths of such resonances, are investigated in a recently proposed unified model of B&#x0305; B<SUB>L</SUB>P and B&#x0305; B<SUB>L</SUB>V couplings. In this phenomenological model, which uses the "quark" language only formally, the couplings BB<SUB>L</SUB>P of baryon resonance (B<SUB>L</SUB>) with pseudoscalar (P) mesons in broken SU(6)&#215;O(3) are extended to incorporate electromagnetic interactions through "partial symmetry" for BB<SUB>L</SUB>V couplings, together with the principle of vector-meson dominance. These supermultiplet L<SUP>P</SUP>&#8594;0<SUP>+</SUP> transitions are characterized by an empirical but relativistically invariant multiplying form factor, for which two different forms are considered. The calculated electromagnetic decay widths for the baryon resonances Y<SUP>*</SUP>(1520) and &#916;(1238) are in extremely good agreement with experiment. For the other resonances no direct experimental data are available, and comparison has been made with other contemporary analyses. The results for the reactions &#947;p&#8594;&#960;<SUP>0</SUP>p, &#947;p&#8594;&#960;<SUP>+</SUP>n, and &#947;n&#8594;&#960;<SUP>-</SUP>p are also presented with reference to the following types of data: (i) total cross sections, (ii) the angular distribution of the differential cross sections, (iii) the energy dependence of the cross sections at fixed angles (especially &#960;=0, &#960;), and (iv) recoilproton polarization. The agreement with the experimental data in all these respects is extremely good, thus suggesting that the direct s channel makes a large and dominant contribution to the amplitude in the intermediate-energy region. The only discrepancy lies in the forward direction for charge-exchange processes, where the t-channel pion pole is known to be important, yet a partial simulation of duality seems to be indicated by our results. Also, the qualitative features of pionic photoproduction are reasonably well reproduced by our model. The Moorhouse selection rule for spin quartet states and a "charge" selection rule proposed recently by Copley et al. are satisfied in the limit of m<SUB>&#961;</SUB>=m<SUB>&#969;</SUB> in our model. The most prominent resonances turn out to be P<SUB>11</SUB>, P<SUB>33</SUB>, D<SUB>13</SUB>, F<SUB>15</SUB>, and F<SUB>37</SUB>

"Recoil effects" in a model of higher baryon couplings. I. Photoproduction

A recently proposed model (MM) of higher baryon couplings for P and V mesons is reformulated by reviewing the fuller possibilities of the "recoil term" in the primitive quark-meson interaction. While this introduces no basic change in the P-meson coupling structures, it yields an entirely new (L-1)-wave coupling of V mesons to J = L+12 baryons, which is capable of generating helicity-flip amplitudes. The advantage of this new coupling structure over the earlier one is demonstrated through the excellent reproduction of (i) the E1 angular distribution in Y*&#8594;&#923;&#947; decay and (ii) the appreciable magnitudes as well as energy variations of the asymmetry parameter &#8721;(&#952;) in pion photoproduction. In addition to a comparison of the two coupling structures (old and new), the present paper is also designed to study the role of still another parametric structure for the form factor - one which exhibits better convergence properties at higher energies than those discussed in MM. The additional processes studied in this connection are (i) &#951; and X0 photoproduction at intermediate energies (&#62; 2 GeV), (ii) polarization of the recoil proton in &#951; and &#960; photoproduction, and (iii) &#960;0 photoproduction at high energies (∼ 6 GeV), in accordance with our earlier scheme of s-channel resonances. In connection with &#951; photoproduction the roles of some pertinent I =12 resonances such as S11, P11, and G17 are discussed, especially in relation to supermultiplet assignments

Immunohistochemical localization and correlation of p53 and PCNA expression in breast carcinoma

225-230The object of the present study is to detect the ·p53 tumour suppressor gene and proliferation cell nuclear antigen (PCNA) expression in breast carcinoma by immunohistochemistry and correlate them with the prognostic parameters. Total 35 cases of primary breast carcinoma were studied and classified histologically. Paraffin sections were stained by using monoclonal antibody D07 for p53 protein and PC-10 for PCNA. Out of 35 cases, 16 (45.7%) were p53 positive and 25 (71.4%) were PCNA positive. The mean PCNA labelling index (PCNA LI ± SD) was 58.97 ± 22.72 in tumors positive for both p53+ and PCNA+ while cases negative for p53- and positive for PCNA+ has higher PCNA LI ± SD (59.24 ± 18.97). The difference in the two groups was not significant. Most cases were positive for both p53+ and PCNA+ in the age group &lt;30 with higher mean PCNA LI±SD (62.20±27.13) than in the group&gt; 30 (57.88±18.47). In the pre-menopausal group 57.1 % cases were positive for p53+ with higher PCNA LI ± SD (59.94±24.22). Maximum p53 and PCNA positivity was observed in grade III tumors (63.2% and 84.2%). The mean PCNA LI ± SD was also highest in grade III carcinomas (66.83±13.97). No significant correlation was found between p53 and PCNA status with morphological type and tumour size except that logistic regression showed a positive correlation with tumour grade. Therefore the present study suggests that both p53 expression and PCNA are markers of poor differentiation in breast cancer