scholarly journals Cerebral cortical communication overshadows computational energy-use, but these combine to predict synapse number

2021 ◽  
Author(s):  
William B Levy ◽  
Victoria G. Calvert
Keyword(s):  
Energy Consumption ◽  
Human Brain ◽  
Energy Efficient ◽  
Neural Computation ◽  
The Other ◽  
Darwinian Evolution ◽  
Energy Audit ◽  
Long Distance ◽  
Communication Costs ◽  
Other Hand

Darwinian evolution tends to produce energy-efficient outcomes. On the other hand, energy limits computation, be it neural and probabilistic or digital and logical. Taking a particular energy-efficient viewpoint, we define neural computation and make use of an energy-constrained, computational function. This function can be optimized over a variable that is proportional to the number of synapses per neuron. This function also implies a specific distinction between ATP-consuming processes, especially computation per se vs the communication processes including action potentials and transmitter release. Thus to apply this mathematical function requires an energy audit with a partitioning of energy consumption that differs from earlier work. The audit points out that, rather than the oft-quoted 20 watts of glucose available to the brain (1, 2), the fraction partitioned to cortical computation is only 0.1 watts of ATP. On the other hand at 3.5 watts, long-distance communication costs are 35-fold greater. Other novel quantifications include (i) a finding that the biological vs ideal values of neural computational efficiency differ by a factor of 108 and (ii) two predictions of N, the number of synaptic transmissions needed to fire a neuron (2500 vs 2000).Significance StatementEngineers hold up the human brain as a low energy form of computation. However from the simplest physical viewpoint, a neuron’s computation cost is remarkably larger than the best possible bits/J – off by a factor of 108. Here we explicate, in the context of energy consumption, a definition of neural computation that is optimal given explicit constraints. The plausibility of this definition as Nature’s perspective is supported by an energy-audit of the human brain. The audit itself requires certain novel perspectives and calculations revealing that communication costs are 35-fold computational costs.

scholarly journals Computation in the human cerebral cortex uses less than 0.2 watts yet this great expense is optimal when considering communication costs

2020 ◽  
Author(s):  
William B Levy ◽  
Victoria G. Calvert
Keyword(s):  
Human Brain ◽  
Energy Efficient ◽  
Darwinian Evolution ◽  
Energy Audit ◽  
Long Distance ◽  
Communication Costs ◽  
Computational Optimization ◽  
Distance Communication ◽  
Definition Of ◽  
The Brain

Darwinian evolution tends to produce energy-efficient outcomes. On the other hand, energy limits computation, be it neural and probabilistic or digital and logical. After establishing an energy-efficient viewpoint, we define computation and construct an energy-constrained, computational function that can be optimized. This function implies a specific distinction between ATP-consuming processes, especially computation per se vs action potentials and other costs of communication. As a result, the partitioning of ATP-consumption here differs from earlier work. A bits/J optimization of computation requires an energy audit of the human brain. Instead of using the oft-quoted 20 watts of glucose available to the brain (1, 2), the partitioning and audit reveals that cortical computation consumes 0.2 watts of ATP while long-distance communication costs are over 20-fold greater. The bits/joule computational optimization implies a transient information rate of more than 7 bits/sec/neuron.Significance StatementEngineers hold up the human brain as a low energy form of computation. However from the simplest physical viewpoint, a neuron’s computation cost is remarkably larger than the best possible bits/joule – off by a factor of 108. Here we explicate, in the context of energy consumption, a definition of neural computation that is optimal given explicit constraints. The plausibility of this definition as Nature’s perspective is supported by an energy-audit of the human brain. The audit itself requires certain novel perspectives and calculations revealing that communication costs are 20-fold computational costs.

scholarly journals Communication consumes 35 times more energy than computation in the human cortex, but both costs are needed to predict synapse number

2021 ◽  
Vol 118 (18) ◽  
pp. e2008173118
Author(s):  
William B Levy ◽  
Victoria G. Calvert
Keyword(s):  
Energy Efficient ◽  
The Other ◽  
Darwinian Evolution ◽  
Mathematical Function ◽  
Energy Audit ◽  
Long Distance ◽  
Human Cortex ◽  
Other Hand ◽  
Communication Processes ◽  
Distance Communication

Darwinian evolution tends to produce energy-efficient outcomes. On the other hand, energy limits computation, be it neural and probabilistic or digital and logical. Taking a particular energy-efficient viewpoint, we define neural computation and make use of an energy-constrained computational function. This function can be optimized over a variable that is proportional to the number of synapses per neuron. This function also implies a specific distinction between adenosine triphosphate (ATP)-consuming processes, especially computation per se vs. the communication processes of action potentials and transmitter release. Thus, to apply this mathematical function requires an energy audit with a particular partitioning of energy consumption that differs from earlier work. The audit points out that, rather than the oft-quoted 20 W of glucose available to the human brain, the fraction partitioned to cortical computation is only 0.1 W of ATP [L. Sokoloff, Handb. Physiol. Sect. I Neurophysiol. 3, 1843–1864 (1960)] and [J. Sawada, D. S. Modha, “Synapse: Scalable energy-efficient neurosynaptic computing” in Application of Concurrency to System Design (ACSD) (2013), pp. 14–15]. On the other hand, long-distance communication costs are 35-fold greater, 3.5 W. Other findings include 1) a 108-fold discrepancy between biological and lowest possible values of a neuron’s computational efficiency and 2) two predictions of N, the number of synaptic transmissions needed to fire a neuron (2,500 vs. 2,000).

scholarly journals Spin Wave Based Approximate 4:2 Compressor

2021 ◽  
Author(s):  
Abdulqader Mahmoud ◽  
Frederic Vanderveken ◽  
Florin Ciubotaru ◽  
Christoph Adelmann ◽  
Said Hamdioui ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Error Rate ◽  
Energy Efficient ◽  
Directional Coupler ◽  
State Of The Art ◽  
The Other ◽  
Average Error ◽  
Majority Gate ◽  
Micromagnetic Simulations ◽  
Average Error Rate

In this paper, we propose an energy efficient SW based approximate 4:2 compressor comprising a 3-input and a 5-input Majority gate. We validate our proposal by means of micromagnetic simulations, and assess and compare its performance with one of the state-of-the-art SW, 45nm CMOS, and Spin-CMOS counterparts. The evaluation results indicate that the proposed compressor consumes 31.5\% less energy in comparison with its accurate SW design version. Furthermore, it has the same energy consumption and error rate as the approximate compressor with Directional Coupler (DC), but it exhibits 3x lower delay. In addition, it consumes 14% less energy, while having 17% lower average error rate than the approximate 45nm CMOS counterpart. When compared with the other emerging technologies, the proposed compressor outperforms approximate Spin-CMOS based compressor by 3 orders of magnitude in term of energy consumption while providing the same error rate. Finally, the proposed compressor requires the smallest chip real-estate measured in terms of devices.

Energy Reduction and Optimisation in Membrane Bioreactor Systems

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
Guihe Tao ◽  
Kiran Kekre ◽  
Maung Htun Oo ◽  
Bala Viswanath ◽  
Aliman MD Yusof ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Energy Efficient ◽  
Specific Energy Consumption ◽  
Pilot Scale ◽  
Energy Reduction ◽  
Energy Audit ◽  
Membrane Flux ◽  
Demonstration Plant ◽  
Set Up

One of the major components of MBR operating expenditure is energy consumption. This paper presents our six-year journey of energy reduction and optimization in MBR systems through various pilot and demonstration studies. Through comprehensive and systematic MBR optimisation studies, the specific energy consumption was reduced from 1.3 kWh m−3 to less than 0.8 kWh m−3 by increasing membrane flux and reducing aeration at 300 m3 per day pilot scale plants. Through energy audit, the key energy consumption components including process aeration, membrane scouring rate, SRT, MLSS level, MLSS recirculation, and energy efficient equipment selection were identified, and these were optimised one by one at 23,000 m3 per day municipal scale MBR demonstration plant after the baseline had been set up. The specific energy consumption was further reduced to 0.37 kWh m−3.

scholarly journals RESEARCH ON SHEAR PERFORMANCE OF COMPONENTS CONNECTED BY BEECH AND SELF-TAPPING SCREW COMPOSITE DOWELS

Wood Research ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 955-968
Author(s):  
XUDONG ZHU ◽  
YINGYING XUE ◽  
XUEWEN ZHANG ◽  
PENGFEI QI ◽  
JIE SHEN ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Linear Equation ◽  
Failure Modes ◽  
Maximum Load ◽  
The Other ◽  
Test Results ◽  
Other Hand ◽  
Shear Performance ◽  
Group B ◽  
Better Than

This study examined the properties of components connected by beech and self-tapping screw composite dowels (group C). As a contrast, the components connected by beech dowels and self-tapping screws individually were tested. The test results indicated that the properties of the components connected by beech dowels (group B) were better than those connected by self-tapping screws (group S), except the ductility coefficient, final displacement, and energy consumption. On the other hand, the main failure modes of groups B and S were the broken beech dowel and the bent self-tapping screw, respectively. For group C, two peak values could be found which were larger than the maximum load of groups B and S, respectively. The properties of group C were better than those of groups B and S, except that the final displacement and energy consumption were located between those of groups B and S. Meanwhile, the linear equation in two unknowns have be found between groups B, S and C.

The Economics of Air Line Operation

1936 ◽  
Vol 40 (312) ◽  
pp. 839-860
Author(s):  
L. T. H. Greig
Keyword(s):  
The Other ◽  
Air Transport ◽  
The Political ◽  
Long Distance ◽  
Other Hand ◽  
The Times ◽  
Considerable Detail

In speaking to you to-night on the Economics of Air Line Operation, I propose to speak primarily from the viewpoint of the operator of an internal air line. I do not mean, by that, that I shall confine my remarks strictly to the various problems encountered by my own particular company, nor do I mean that any opinions which I may express will, of necessity, be of interest only to operators of internal services. On the other hand, I do not intend to venture into the realms of very long distance air routes, such as Empire routes, many of the problems connected with which have already been dealt with in considerable detail by Mr. Woods Humphrey in his interesting series of articles in The Times in May of this year. Such small experience as I have had so far with international flying has convinced me that the political difficulties, which are undoubtedly encountered by many of the national air transport companies, must force upon them policies other than those dictated by strictly economic requirements, and in consequence, must render a true comparison between their operation and purely European flying almost impossible.

Energy Efficient Cluster-based Routing using Hybrid Approach of Fuzzy and Ida-Star for Wireless Sensor Networks

2021 ◽  
Author(s):  
Mohaideen Pitchai K
Keyword(s):  
Fuzzy Logic ◽  
Energy Consumption ◽  
Energy Efficient ◽  
Clustering Algorithm ◽  
Cluster Formation ◽  
Hybrid Approach ◽  
Cluster Head ◽  
Residual Energy ◽  
The Other ◽  
Cluster Head Selection

Abstract Appropriate cluster head selection can significantly reduce energy consumption and enhance the lifetime of the WSN. The choice of cluster heads, which is a pivotal step in the cluster-based algorithm, can seriously influence the performance of the clustering algorithm. Under normal circumstances, whether a node can be a cluster head or not depends not only on its energy level but also on the other factors such as energy consumption, channel lost, neighbor density, etc. In this sense, the selection of the cluster head can be regarded as a multiple criteria decision-making issue. This paper presents an Energy efficient Cluster Head selection using Fuzzy Logic (ECHFL) protocol, which combines the approaches of the fuzzy and IDA-star algorithm. This protocol selects the appropriate cluster head by using fuzzy inference rules. It uses three parametric descriptors such as residual energy, expected residual energy, and node centrality for the cluster formation and cluster head selection processes. These parameters contribute mainly for avoiding over-dissipation of energy in the network by selecting the suitable cluster head for the network. This protocol shows how fuzzy logic can be used in the cluster formation process to distribute the tasks and energy consumption over all the nodes. As a summary, the proposed protocol gives good performance results in comparison with the other protocols.

CORTISOLWIRKUNGEN AUF DEN PROTEINUND ENERGIESTOFFWECHSEL IN DER PERIPHERIE

1968 ◽  
Vol 59 (2) ◽  
pp. 193-202
Author(s):  
H. Kröner ◽  
W. Staib
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Energy Consumption ◽  
Connective Tissue ◽  
Oxidative Metabolism ◽  
The Other ◽  
Other Hand ◽  
Inhibition Of Protein Synthesis ◽  
Short Time ◽  
Rna And Dna

ABSTRACT By measuring protein, RNA and DNA in skeletal muscle and spleen we were unable to demonstrate an enhanced catabolism due to cortisol. On the other hand we could demonstrate a reduced anabolism by diminished incorporation of 14C labelled leucin in protein of muscle, spleen and skin. Simultaneously an increase of ATP and an equivalent decrease of ADP were found in connective tissue, which were regarded as a consequence of reduced energy consumption. In skeletal muscle a decrease of energy consumption due to cortisol was only indirect demonstrable by reduced glycolysis when oxidative metabolism was eliminated for a short time. It seems obvious, that inhibition of protein synthesis causes the diminished energy consumption.

scholarly journals Analyze the Development Status and Optimization Strategies of Food Cold Chain Logistics

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Yujie Li ◽  
Khor Kok Keat
Keyword(s):  
Living Standards ◽  
The Other ◽  
Cold Chain ◽  
Long Distance ◽  
Logistics Industry ◽  
Development Status ◽  
Other Hand ◽  
Comprehensive Level ◽  
Good For

<p>Researchers pointed out that in recent years, with the improvement and optimization of living standards, the food cold chain logistics industry has developed vigorously. In general, based on the promotion of food cold chain logistics, researchers can further realize the reasonable exploration of cold chain logistics, so as to effectively realize the overall development and construction of cold chain logistics, which is good for the reasonable satisfaction of the people’s dietary needs. The promotion of meaning and value. On the other hand, the development of the cold chain logistics industry has further realized the reasonable satisfaction of the requirements of the cold chain transportation of food materials, has a good guiding role in the realization of long-distance transportation of food materials, and is conducive to the diversified development of the people’s diet structure. However, at present, in the process of food cold chain logistics work, my country still has certain shortcomings to be improved. This article analyzes the development status of food cold chain logistics, and proposes corresponding optimization strategies at the same time, aiming to effectively realize the improvement and optimization of the comprehensive level of my country’s food cold chain logistics industry.</p>

scholarly journals A Cross-Sectoral Investigation of the Energy–Environment–Economy Causal Nexus in Pakistan: Policy Suggestions for Improved Energy Management

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5495
Author(s):  
Rizwan Fazal ◽  
Syed Aziz Ur Rehman ◽  
Muhammad Ishaq Bhatti ◽  
Atiq Ur Rehman ◽  
Fariha Arooj ◽  
...  
Keyword(s):  
Economic Growth ◽  
Energy Consumption ◽  
Co2 Emissions ◽  
The Other ◽  
Economic Output ◽  
Industrial Sectors ◽  
Other Hand ◽  
Energy Environment ◽  
Pc Algorithm ◽  
Causal Nexus

This paper explored the energy–environment–economy (EEE) causal nexus of Pakistan, thereby reporting the causal determinants of the EEE nexus by employing the newly developed modified Peter and Clark (PC) algorithm. The modified PC algorithm was employed to investigate the causal ordering of energy consumption, CO2 emissions and economic growth across Pakistan’s domestic, industrial, transportation and agricultural sectors. An empirical comparison, i.e., following Monte Carlo simulation experiments demonstrates that the proposed modified PC algorithm is superior to the original PC proposition and can differentiate between true and spurious nexus causalities. Our results show that significant causality is running from energy consumption in industrial and agricultural sectors towards economic growth. There is no causal association between energy consumption and economic growth in the domestic and transportation sectors. On the other hand, causality runs from energy consumption in the transportation, domestic and industrial sectors towards CO2 emissions. It is concluded that energy consumption in industrial and agricultural sectors leads to economic growth alongside the associated CO2 emissions. On the other hand, the contribution of domestic and transportation sectors in economic growth is trivial with significant CO2 emissions. This paper provides novel empirical evidence of impacts of energy mismanagement at sectoral levels, economic output and environmental consequences; alongside policy recommendations for sustainable energy-based development on the national scale.

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