scholarly journals An evolutionary scheduling approach for trading-off accuracy vs. verifiable energy in multicore processors

2017 ◽  
Vol 25 (6) ◽  
pp. 1006-1019
Author(s):  
U Liqat ◽  
Z Banković ◽  
P Lopez-Garcia ◽  
M V Hermenegildo
Keyword(s):  
Energy Consumption ◽  
Energy Budget ◽  
Energy Efficient ◽  
Energy Savings ◽  
Multicore Processors ◽  
Work Load ◽  
Control Flow ◽  
Upper And Lower Bounds ◽  
Energy Bound ◽  
Energy Efficient Scheduling

Abstract This work addresses the problem of energy-efficient scheduling and allocation of tasks in multicore environments, where the tasks can allow a certain loss in accuracy in the output, while still providing proper functionality and meeting an energy budget. This margin for accuracy loss is exploited by using computing techniques that reduce the work load, and thus can also result in significant energy savings. To this end, we use the technique of loop perforation, that transforms loops to execute only a subset of their original iterations, and integrate this technique into our existing optimization tool for energy-efficient scheduling. To verify that a schedule meets an energy budget, both safe upper and lower bounds on the energy consumption of the tasks involved are needed. For this reason, we use a parametric approach to estimate safe (and tight) energy bounds that are practical for energy verification (and optimization applications). This approach consists in dividing a program into basic (‘branchless’) blocks, establishing the maximal (resp. minimal) energy consumption for each block using an evolutionary algorithm, and combining the obtained values according to the program control flow, by using static analysis to produce energy bound functions on input data sizes. The scheduling tool uses evolutionary algorithms coupled with the energy bound functions for estimating the energy consumption of different schedules. The experiments with our prototype implementation were performed on multicore XMOS chips, but our approach can be adapted to any multicore environment with minor changes. The experimental results show that our new scheduler enhanced with loop perforation improves on the previous one, achieving significant energy savings (31% on average for the test programs) for acceptable levels of accuracy loss.

scholarly journals Analysis of Energy Efficient Scheduling of the Manufacturing Line with Finite Buffer Capacity and Machine Setup and Shutdown Times

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7446
Author(s):  
Adrian Kampa ◽  
Iwona Paprocka
Keyword(s):  
Energy Consumption ◽  
Production System ◽  
Energy Efficient ◽  
Parallel Flow ◽  
Finite Buffer ◽  
Series Production ◽  
Delivery Cost ◽  
Multi Objective ◽  
Parallel Flows ◽  
Energy Efficient Scheduling

The aim of this paper is to present a model of energy efficient scheduling for series production systems during operation, including setup and shutdown activities. The flow shop system together with setup, shutdown times and energy consumption are considered. Production tasks enter the system with exponentially distributed interarrival times and are carried out according to the times assumed as predefined. Tasks arriving from one waiting queue are handled in the order set by the Multi Objective Immune Algorithm. Tasks are stored in a finite-capacity buffer if machines are busy, or setup activities are being performed. Whenever a production system is idle, machines are stopped according to shutdown times in order to save energy. A machine requires setup time before executing the first batch of jobs after the idle time. Scientists agree that turning off an idle machine is a common measure that is appropriate for all types of workshops, but usually requires more steps, such as setup and shutdown. Literature analysis shows that there is a research gap regarding multi-objective algorithms, as minimizing energy consumption is not the only factor affecting the total manufacturing cost—there are other factors, such as late delivery cost or early delivery cost with additional storage cost, which make the optimization of the total cost of the production process more complicated. Another goal is to develop previous scheduling algorithms and research framework for energy efficient scheduling. The impact of the input data on the production system performance and energy consumption for series production is investigated in serial, parallel or serial–parallel flows. Parallel flow of upcoming tasks achieves minimum values of makespan criterion. Serial and serial–parallel flows of arriving tasks ensure minimum cost of energy consumption. Parallel flow of arriving tasks ensures minimum values of the costs of tardiness or premature execution. Parallel flow or serial–parallel flow of incoming tasks allows one to implement schedules with tasks that are not delayed.

scholarly journals Energy Efficient Lighting Design Criteria: Cost-Effective Solutions in an Industrial Environment

2007 ◽  
Author(s):  
Frank J. Agraz ◽  
John Maneri
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Return On Investment ◽  
Energy Savings ◽  
Cost Effective ◽  
Lighting Design ◽  
Design Criteria ◽  
Lighting System ◽  
Light Levels

The continual rising cost of energy, existing outdated lighting technology, and inefficient lighting designs have given property owners the opportunity to improve their facilities by retrofitting their existing luminaires with an energy efficient lighting system. A lighting retrofit uses the existing electrical infrastructure to replace, relocate, or convert existing luminaires with the latest generation of cost-effective components. New lighting technology has emerged within the last 6 years that generates energy savings of 40% to 50% while maintaining existing light levels. These upgraded and field-tested solutions lower energy consumption, generate a healthy financial return on investment, and can improve both the quality and quantity of light in the task area. As with any other solution, a cost-effective lighting system must be designed and engineered carefully to accommodate the needs of each work space. Simply installing a new lamp into an existing luminaire will not necessarily guarantee substantial energy savings or an improved lighting environment. In any space that uses electric lighting, the lighting designer must evaluate potential solutions for energy consumption, maintenance concerns, delivered light levels, hostile environments, and the overall economic impact of installing and long-term operation of the new system. In this paper, the author will discuss energy efficient lighting design criteria and how a lighting designer properly engineers a retrofit project to deliver energy savings without sacrificing light levels. The discussion includes a summary of both traditional and emerging technologies, and the long-term impact on energy consumption, maintenance, return on investment, lighting quality, and delivered light levels. Paper published with permission.

Energy Efficient Schemes for Base Station Management in 4G Broadband Systems

2014 ◽  
pp. 100-120 ◽  
Author(s):  
Alexandra Bousia ◽  
Elli Kartsakli ◽  
Angelos Antonopoulos ◽  
Luis Alonso ◽  
Christos Verikoukis
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Savings ◽  
Base Station ◽  
Base Stations ◽  
Traffic Load ◽  
Network Resources ◽  
Load Variations ◽  
Mobile Cellular ◽  
Main Component

Reducing the energy consumption in wireless networks has become a significant challenge, not only because of its great impact on the global energy crisis, but also because it represents a noteworthy cost for telecommunication operators. The Base Stations (BSs), constituting the main component of wireless infrastructure and the major contributor to the energy consumption of mobile cellular networks, are usually designed and planned to serve their customers during peak times. Therefore, they are more than sufficient when the traffic load is low. In this chapter, the authors propose a number of BSs switching off algorithms as an energy efficient solution to the problem of redundancy of network resources. They demonstrate via analysis and by means of simulations that one can achieve reduction in energy consumption when one switches off the unnecessary BSs. In particular, the authors evaluate the energy that can be saved by progressively turning off BSs during the periods when traffic decreases depending on the traffic load variations and the distance between the BS and their associated User Equipments (UEs). In addition, the authors show how to optimize the energy savings of the network by calculating the most energy-efficient combination of switched off and active BSs.

Energy Efficient Scheduling for Multiple Workflows in Cloud Environment

2018 ◽  
Vol 13 (3) ◽  
pp. 14-34
Author(s):  
Ritu Garg ◽  
Neha Shukla
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Cloud Environment ◽  
Cloud Data ◽  
Available Energy ◽  
Cloud Data Centers ◽  
Reduce Energy Consumption ◽  
Scheduling Heuristic ◽  
Communication Stage ◽  
Energy Efficient Scheduling

Cloud computing makes utility computing possible with pay as you go model. It virtualizes the systems by polling and sharing the resources, thus we need to handle more than one workflow at the same time. Workflow is the standard to represent compute intensive applications in scientific and engineering domain. Hence, in this article, the authors presented the scheduling heuristic for multiple workflows running parallel in the cloud environment with the aim to reduce the energy consumption as it is one of the major concerns of cloud data centers along with the execution performance. In the proposed approach, first clustering is performed to minimize the energy consumption and execution time during communication corresponding to precedence constraint tasks. Then cluster are scheduled is on the best available energy efficient resources. Finally, DVFS is applied in order to reduce energy consumption further when the nodes are in the idle and communication stage. The simulation has been performed on CloudSim and the results show the reduction in energy consumption by up to 42%.

scholarly journals Powertrain Optimization for Electric Buses under Optimal Energy-Efficient Driving

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6451
Author(s):  
Alexander Koch ◽  
Olaf Teichert ◽  
Svenja Kalt ◽  
Aybike Ongel ◽  
Markus Lienkamp
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Savings ◽  
Ride Comfort ◽  
Programming Approach ◽  
Automated Driving ◽  
Dynamic Programming Approach ◽  
Optimal Energy ◽  
Driving Cycles ◽  
Powertrain Configuration

State of the art powertrain optimization compares the energy consumption of different powertrain configurations based on simulations with fixed driving cycles. However, this approach might not be applicable to future vehicles, since speed advisory systems and automated driving functions offer the potential to adapt the speed profile to minimize energy consumption. This study aims to investigate the potential of powertrain optimization with respect to energy consumption under optimal energy-efficient driving for electric buses. The optimal powertrain configurations of the buses under energy-efficient driving and their respective energy consumptions are obtained using powertrain-specific optimized driving cycles and compared with those of human-driven unconnected buses and buses with non-powertrain-specific optimal speed profiles. Based on the results, new trends in the powertrain design of vehicles under energy-efficient driving are derived. The optimized driving cycles are calculated using a dynamic programming approach. The evaluations were based on the fact that the buses under energy-efficient driving operate in dedicated lanes with vehicle-to-infrastructure (V2I) communication while the unconnected buses operate in mixed traffic. The results indicate that deviating from the optimal powertrain configuration does not have a significant effect on energy consumption for optimized speed profiles; however, the energy savings from an optimized powertrain configuration can be significant when ride comfort is considered. The connected buses under energy-efficient driving operating in dedicated lanes may reduce energy consumption by up to 27% compared to human-driven unconnected buses.

scholarly journals A Simulation Approach for Optimising Energy-Efficient Driving Speed Profiles in Metro Lines

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6038
Author(s):  
Mariano Gallo ◽  
Marilisa Botte ◽  
Antonio Ruggiero ◽  
Luca D’Acierno
Keyword(s):  
Energy Consumption ◽  
Simulation Model ◽  
Travel Time ◽  
Energy Efficient ◽  
Energy Savings ◽  
Simulation Software ◽  
Gradient Algorithm ◽  
Simulation Approach ◽  
Driving Speed ◽  
Optimisation Model

We propose a model for optimising driving speed profiles on metro lines to reduce traction energy consumption. The model optimises the cruising speed to be maintained on each section between two stations; the functions that link the cruising speed to the travel time on the section and the corresponding energy consumption are built using microscopic railway simulation software. In addition to formulating an optimisation model and its resolution through a gradient algorithm, the problem is also solved by using a simulation model and the corresponding optimisation module, with which stochastic factors may be included in the problem. The results are promising and show that traction energy savings of over 25% compared to non-optimised operations may be achieved.

scholarly journals Energy-Efficient Clusters for Object Tracking Networks

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2015 ◽  
Author(s):  
Yang-Hsin Fan
Keyword(s):  
Energy Consumption ◽  
Object Tracking ◽  
Energy Efficient ◽  
Energy Savings ◽  
Smart Cities ◽  
Tracking System ◽  
Cluster Structure ◽  
Equivalent Model ◽  
Save Energy ◽  
Tracking Devices

Smart cities have hundreds of thousands of devices for tracking data on crime, the environment, and traffic (such as data collected at crossroads and on streets). This results in higher energy usage, as they are recording information persistently and simultaneously. Moreover, a single object tracking device, on a corner at an intersection for example has a limited scope of view, so more object tracking devices are added to broaden the view. As an increasing number of object tracking devices are constructed on streets, their efficient energy consumption becomes a significant issue. This work is concerned with decreasing the energy required to power these systems, and proposes energy-efficient clusters (EECs) of object tracking systems to achieve energy savings. First, we analyze a current object tracking system to establish an equivalent model. Second, we arrange the object tracking system in a cluster structure, which facilitates the evaluation of energy costs. Third, the energy consumption is assessed as either dynamic or static, which is a more accurate system for determining energy consumption. Fourth, we analyze all possible scenarios of the object’s location and the resulting energy consumption, and derive a number of formulas for the fast computation of energy consumption. Finally, the simulation results are reported. These results show the proposed EEC is an effective way to save energy, compared with the energy consumption benchmarks of current technology.

scholarly journals EVALUATION OF ENERGY-EFFICIENT RETROFIT POTENTIAL FOR GOVERNMENT OFFICES IN INDIA

2021 ◽  
Vol 6 (2) ◽  
pp. 03-17
Author(s):  
Gazal Dandia ◽  
◽  
Pratheek Sudhakaran ◽  
Chaitali Basu ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Efficient ◽  
Energy Demand ◽  
Energy Savings ◽  
High Energy ◽  
Payback Period ◽  
Total Energy Consumption ◽  
The Cost

Introduction: High energy consumption by buildings is a great threat to the environment and one of the major causes of climate change. With a population of 1.4 billion people and one of the fastest-growing economies in the world, India is extremely vital for the future of global energy markets. The energy demand for construction activities continues to rise and it is responsible for over one-third of global final energy consumption. Currently, buildings in India account for 35% of total energy consumption and the value is growing by 8% annually. Around 11% of total energy consumption are attributed to the commercial sector. Energy-efficient retrofitting of the built environments created in recent decades is a pressing urban challenge. Presently, most energy-efficient retrofit projects focus mainly on the engineering aspects. In this paper, we evaluate various retrofitting options, such as passive architectural interventions, active technological interventions, or a combination of both, to create the optimum result for the selected building. Methods: Based on a literature study and case examples, we identified various energy-efficient retrofit measures, and then examined and evaluated those as applied to the case study of Awas Bhawan (Rajasthan Housing Board Headquarters), Jaipur, India. For the evaluation, we developed a simulation model using EQuest for each energy measure and calculated the resultant energy savings. Then, based on the cost of implementation and the cost of energy saved, we calculated the payback period. Finally, an optimum retrofit solution was formulated with account for the payback period and ease of installation. Results and discussion: The detailed analysis of various energy-efficient retrofit measures as applied to the case study indicates that the most feasible options for retrofit resulting in optimum energy savings with short payback periods include passive architecture measures and equipment upgrades.

scholarly journals THE ADVANTAGE OF GENETIC ALGORITHM IN ENERGY-EFFICIENT SCHEDULING FOR HETEROGENEOUS CLOUD COMPUTING

2016 ◽  
Vol 4 (7) ◽  
pp. 1-9
Author(s):  
Hang Zhou ◽  
Samina Kausar ◽  
Ningning Dong
Keyword(s):  
Genetic Algorithm ◽  
Cloud Computing ◽  
Energy Consumption ◽  
Energy Efficient ◽  
Scheduling Problem ◽  
New Energy ◽  
Heavy Burden ◽  
Heterogeneous Cloud ◽  
Energy Efficient Scheduling ◽  
Computing Infrastructure

Nowadays Energy Consumption has been a heavy burden on the enterprise cloud computing infrastructure. This paper focuses on the hardware factors in energy consumption. Inspired by DVFS, it proposes a new energy-efficient (EE) model. This paper formulates the scheduling problem and genetic algorithm is applied to obtain higher efficiency value. Simulations are implemented to verify the advantage of genetic algorithm. In addition, the robustness of our strategy is validated by modifying the relevant parameters of the experiment.

scholarly journals A Design Strategy for Energy-Efficient Rural Houses in Severe Cold Regions

2020 ◽  
Vol 17 (18) ◽  
pp. 6481
Author(s):  
Wente Pan ◽  
Hongyuan Mei
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Efficient ◽  
Urban Areas ◽  
Energy Savings ◽  
Rapid Development ◽  
Low Energy ◽  
Cold Regions ◽  
Rural Buildings ◽  
Savings Rate

In the past decade, Chinese urban areas have seen rapid development, and rural areas are becoming the next construction hotspot. The development of rural buildings in China has lagged behind urban development, and there is a lack of energy-efficient rural buildings. Rural houses in severe cold regions have the characteristics of large energy exchange, a long heating cycle, and low construction costs. Energy consumption is a crucial issue for rural houses in severe cold regions. How to balance the energy efficiency and building cost become a crucial problem. To solve this problem, we investigate the energy consumption of rural housing in cold regions, using Longquan Village in Heilongjiang Province, northeast China, as a case study. A low-energy design framework is established that considers the spatial layout, building type, enclosure system, and heating system. With the support of project funds, a demonstration house is constructed, and the energy savings performance of the building is investigated during the heating period. The results indicate that the energy savings rate of the demonstration house is 66%. The demonstration building enables local residents to learn construction methods for low-energy houses and promotes energy efficiency.

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