Measured Energy Consumption Research Articles

Fully Integrated Analog Machine Learning Classifier Using Custom Activation Function for Low Resolution Image Classification

This paper presents fully-integrated analog neural network classifier architecture for low resolution image classification that eliminates memory access. We design custom activation functions using single-stage common-source amplifiers, and apply a hardware-software co-design methodology to incorporate knowledge of the custom activation functions into the training phase to achieve high accuracy. Performing all computations entirely in the analog domain eliminates energy cost associated with memory access and data movement. We demonstrate our classifier on multinomial classification task of recognizing down-sampled handwritten digits from MNIST dataset. Fabricated in 65nm CMOS process, the measured energy consumption for down-sampled MNIST dataset is 173pJ/classification, which is $3\times $ better than state-of-the-art. The prototype IC achieves mean classification accuracy of 81.3% even after down-sampling the original MNIST images by 96% from $28\times 28$ pixels to $5\times 5$ pixels.

Software synthesis from dataflow schedule graphs

The dataflow-model of computation is widely used in design and implementation of signal processing systems. In dataflow-based design processes, scheduling—the assignment and coordination of computational modules across processing resources—is a critical task that affects practical measures of performance, including latency, throughput, energy consumption, and memory requirements. Dataflow schedule graphs (DSGs) provide a formal abstraction for representing schedules in dataflow-based design processes. The DSG abstraction allows designers to model a schedule as a separate dataflow graph, thereby providing a formal, abstract (platform- and language-independent) representation for the schedule. In this paper, we introduce a design methodology that is based on explicit specifications of application graphs and schedules as cooperating dataflow models. We also develop new techniques and tools for automatically synthesizing efficient implementations on multicore platforms from these coupled application and schedule models. We demonstrate the proposed methodology and synthesis techniques through a case study involving real-time detection of people and vehicles using acoustic and seismic sensors.

Does maintainability relate to the energy consumption of software? A case study

Energy consumption of software has been becoming increasingly significant, since it can vary according to how the software has been developed. In recent years, developers and researchers have been interested in analyzing, among other things, how energy consumption evolves when changes occur from one version to another in any given software. Thus far, the only studies available are theoretical papers that reinforce the idea that maintainability may have an influence on energy use, but this needs to be proven empirically, which is the goal of this article. This work presents an empirical study carried out to test whether there is a relationship between the energy consumption and the maintainability of several versions of Redmine. Maintainability has been assessed by means of different measures, such as the number of lines of code, or the complexity of the software, calculated using SonarCloud, and the energy consumption measurements have been captured using the EET device. The results obtained show that the number of lines of code affects both the energy consumption of the processor and the total consumption of the computer where the software is run. It is intended that the results from this work should serve as a basis for the undertaking of new empirical studies which will enable the relationship between the software maintainability and the energy efficiency of that software to be better understood.

A Survey of Energy Consumption Measurement in Embedded Systems

The low-power design of software and hardware is crucial for the efficiency and sustainability of embedded systems. Accurate energy consumption measurement plays a vital role in evaluating the energy performance of software and hardware, which also provides design insights to develop new paradigms for algorithm or code optimization in terms of energy efficiency and system cost. A few literature has surveyed this research field, but it lacks multi-faceted comparisons and comprehensive analysis. In this paper, we first show the necessity of accurate energy consumption analysis for embedded systems. Then, we study major methods in literature for measuring energy consumption of embedded systems, which can be summarized with three categories: 1) measurement-based energy profiling, 2) model-based energy estimation, and 3) simulator-based energy estimation. Some subcategories are further made based on characteristics of these approaches. The pros and cons of each category have been reviewed and evaluated through multi-faceted comparisons. Finally, for transparent energy analysis and improving the energy efficiency of embedded systems, we come up with some contributing factors that matter the energy consumption measurements and discuss the challenges and future research directions.

Investigation of the thermal behavior and energy consumption of refrigeration systems

The object of this research study is to develop a thermal simulation model that can be used to investigate the thermal parameters of the refrigerant systems (with ON/OFF and PID control) used in cooling chambers. Moreover, the model was further developed which takes into account also the types of compressors, feeder, and control units used commonly in practice for energetic investigations. Using the measured energy consumption data obtained by experimental tests during the previous phase of this research work, the validation of the developed energy simulation model by MATLAB R2016a could be also achieved with good agreement. The MATLAB software seemed to be the most appropriate tool for numerical investigations on the energy consumption of refrigeration systems used in commercial cold stores and transient behavior of the indoor air temperature of the cold store, cooling energy performance and consumed energy to the goods stored in cold store.

Design, Implementation, and Deployment of an IoT Based Smart Energy Management System

Growth of population and the inception of new devices every day comes with an incessant rise in energy consumption and has brought great challenges in terms of energy management at the consumer side. With the evolution of technology, smart meters (SMs) are not only considered merely as tools to measure energy consumption but act as a main resource of energy management systems. The application of SM spans over a wide range of advantages, including accurate billing data, information of utilization at the user end, the establishment of two-way communication and remote control of the user equipment. SM is the most essential element of a smart power grid that with the help of any smart energy management system (SEMS), assesses, measures, controls, implements and communicates power allocation, utilization, and consumption at both, single device, and network level. Data provided by the SMs is used by power supply companies to revolutionize power distribution and consumption through various techniques such as, non-intrusive load monitoring and demand-side management (DSM). For efficient data gathering and utilization, internet of things (IoT) is emerging as a key partner in the power industry leading to effective resource management. This paper provides presentation, deployment, and validation of an IoT based SEMS strategy and its related benefits to overcome challenges of energy management at consumer side. The presented SEMS incorporates various communication interfaces and protocols to integrate with any software-based smart solution. In this work, Entrack software is used for data gathering and analysis. As a proof of concept, the presented system is tested and implemented in 4 different buildings of a well-known private company in Pakistan, i.e., Stylo Pvt. Ltd. The case study analysis in this work shows the effectiveness of the presented IoT based SEMS.

Modelling of Variable Energy Consumption for CNC Machine Tools

Machining is a prevalent process in manufacturing industries and consumes a considerable amount of energy which causes adverse environmental effects. Establishing an accurate energy evaluation model is essential for a sustainable machining process. An extensive amount of research work is conducted to model energy consumption for the constant material-removal rate machining processes such as turning and milling. However, no significant attempt is made to model energy consumed during variable material-removal rate machining processes like end face turning, grooving etc., which results in a substantial amount of error for the prediction of the total energy required for machining a product. In this work, experiments are performed on a computerized numerical control machine tool to acquire the material-removal energy consumption of end face turning process. The fluke 435 power analyzer is used to measure energy consumption. An empirical model is established between cutting parameters and energy consumed during the end face turning process. The coefficient of determination is used to evaluate the fitness of the model. The results indicate that the model can predict the end face turning energy consumption data accurately. The developed model can be further used to estimate the total energy consumption for machining of a product beforehand in early design stages and to identify the most suitable sustainable machining options.

Electrical Energy Consumption Interface in Modular Skill-Based Production Systems with the Asset Administration Shell

Modular production systems provide the opportunity to react more flexibly to customer-individual requirements resulting in smaller batch sizes. The implementation of capabilities in production systems leads to a skill-based production which manifests on the modular level. Electrical energy consumption can be analyzed more in detail if the consumption can be linked to the respective skill. The aim of this paper is to show the conception of an energy consumption interface in a modular skill-based production environment with the Asset Administration Shell. The current state of the art of modular skill-based production and modular energy consumption measurement with Infrastructure Nodes and Asset Administration Shell is introduced. The role of the modular level for an energy consumption interface and conceptional approaches of this interface to access and collect consumption data is presented on this basis. Furthermore, the prototypical implementation of the energy related Asset Administration Shell submodel with the BaSyx-Middleware is presented.

Alternativa energética sustentable mediante la utilización de aislantes térmicos de diferentes materiales en edificaciones con sistemas de aire acondicionado

A methodology is proposed for calculating the cooling load and the energy consumption of air conditioning equipment in three scale models of buildings under study, using the ASHRAE CLTD / SCL / CLF method. The building in which the mentioned method is used are three scale models of buildings located in the city of Poza Rica, state of Veracruz, Mexico. This method is applied in order to obtain the cooling load as exact as possible and thus avoid oversizing in air conditioning equipment, and by using thermal insulation, achieve a decrease in energy consumption and thus contribute to the reduction of CO2 emissions, to energy saving and therefore to sustainable development. The cooling load is calculated by applying the proposed methodology to three cases: model A, B and C. The results for the three test models, object of this study, are compared. Measurements of energy consumption are made to perform the error analysis of the actual energy consumption with respect to that calculated using the method. Finally, energy savings are quantified, in the cases mentioned.

PowerDoW (Power Digital Offset Weightage): Video Content-Adaptation (VCA) Profiling in Smartphone Devices for Energy Efficiency

Nowadays, the rapid enhancement of Internet connectivity and the recent progression of smartphone technologies lead to better smartphones quality towards video streaming activity. With the massive production of smartphone devices today, motivate studies of energy consumption behaviors to extend the smartphone device battery-life. Therefore, existing designs for smartphone devices occasionally lack energy-aware thus it need profiling optimization technique that reduces energy usage. Energy profiling in smartphone devices is one of the practical criteria for saving energy in smartphone devices during video streaming session. Energy efficiency features for smartphone devices, profiling and video content adaptation approach are the most critical parts for the energy-efficient while streaming in course. However, the consideration of energy-aware profiling area has not yet been discovered widely. In this case, appointing promising approaches will be used to reduce energy consumption in the smartphone devices during video streaming session. A framework called PowerDoW will be benefited towards adding energy adaptation strategies. PowerDoW framework manage and utilize system profiling status to attain the entire streaming session activity and classify the streaming video format depending on the selective video parameter. Selection of the best quality depending on low energy usage will be determined in the profiling experimentation. The experimentations are based on the Android operating system in smartphone devices—instrumentation setup testing by using PowerTutor application to measure energy consumption in real-time. The result indicates that PowerDoW framework can reduce a huge energy consumption by selecting suitable video content adaptation during video streaming session.

Measuring energy and environmental efficiency interactions towards CO2 emissions reduction without slowing economic growth in central and western Europe

Given the economic growth and energy consumption patterns, most countries are striving to solve the problems of CO2 emissions reduction to achieve sustainable development. This paper employs an improved DEA model to measure energy and environmental efficiency for some selected countries in central and western Europe. In addition, the DEA window evaluation technique is applied to measure cross-sectional efficiency using two inputs (energy consumption, labor force), a desirable output (gross domestic product), and an undesirable output (CO2 emission) for the period from 2010 to 2014. The study finds that the UK ranks the highest position in term of energy and environmental efficiency. This shows that the UK has more effective policies regarding energy efficiency, consumption, production, import and energy intensity measures for sustainable economic growth as well as environmental protection. Ireland is the second-best country after the United Kingdom. The efficiency scores of the two countries are 0.99 and 0.89 respectively. On the empirical outcomes, this study suggests effective reforms in energy sector for countries with less energy efficiency that are still facing the problem of environmental degradation.

Area- and Energy-Efficient Sub-GHz Impulse Radio UWB Transmitter With Output Amplitude Enhancement for Biomedical Implants

This brief presents an almost fully digital edge-combining impulse radio ultra-wideband (UWB) transmitter. The proposed output amplitude enhancement technique increases the peak-to-peak amplitude of the UWB output pulse to more than two times that of the traditional UWB transmitter. The pulse width adjustment circuit is designed to ensure the robustness of the UWB circuit against process, supply voltage, and temperature variations. The output power spectrum density of this transmitter is primarily concentrated in the range of 0-960 MHz and can satisfy the mask requirement of the Federal Communication Commission for UWB communication. The proposed UWB transmitter is implemented in a 0.18- μm CMOS process and occupies an area of 97.41 × 68.6 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measurement results of 20 samples indicate that the average output amplitude is 106.02 mV at a supply voltage of 1 V. At the data transmission rate of 50 Mbps, the measured energy consumptions are 11.18 and 3.97 pJ/bit, respectively, at the supply voltages of 1 and 0.8 V.

A new clustering technique based on replication for MANET routing protocols

The cluster head nodes in most mobile ad hoc networks (MANET) clustering protocols take on an extraordinary role in managing routing information. The reliability, efficiency and scalability of the clustering in MANET will ultimately be dramatically impacted. In this work we establish a new approach to form the clusters in MANET called the square cluster-based routing protocol (SCBRP). That protocol is based on the theory of replication. The goal of the protocol is to achieve reliability, availability and scalability with in the MANET. The proposed protocol is evaluated by caring the performance analysis using the NS-3 simulator. The performance shows 50% improvementin data delivering ratio in large network size, also shows an improvement in network stability and availability which is reflected in energy consumption measurements and increase in the system lifetime to 20%.

Oral Kefir Grains Supplementation Improves Metabolism and Liver Antioxidant Enzymes Expression in Malnourished Mice

Scope: This study has a novel approach to investigate the effects of oral supplementation of kefir grains on metabolic improvement and the expression of the antioxidant enzymes Glutathione Peroxidase (GPx) and Catalase (CAT) of the liver in malnourished mice. Method and Results: Swiss mice were divided into four groups and subjected to two treatment phases: the food restriction phase of 20% in relation to the control group was maintained until animals reached a weight deficit of about 20% in relation to their original weight and the renutrition phase, the animals received diets every day for 30 days. Diets (chow powder plus kefir grains) were administered orally. Thereafter, during throughout the experiment measurements of body weight and energy consumption were obtained. After the end of treatment, fasting glucose tolerance tests were performed at night and insulin sensitivity with fed mice. Soon in then, the mice were euthanized by beheading in guillotine and the blood and liver were collected for evaluation of biochemical parameters, Histopathological assessments and Reverse transcriptase (RT-PCR). Conclusion: The present study demonstrated the kefir grains ability to modulate inflammation and hepatic oxidative-stress under malnourished-state. Keywords: Food Restriction; Malnutrition; Hepatic; Oxidative Stress; Nutrition

Analysis of the Applicability of Non-Destructive Techniques to Determine In Situ Thermal Transmittance in Passive House Façades

Within the European framework, the passive house has become an essential constructive solution in terms of building efficiency and CO2 reduction. However, the main approaches have been focused on post-occupancy surveys, measurements of actual energy consumption, life-cycle analyses in dynamic conditions, using simulation, and the estimation of the thermal comfort. Few studies have assessed the in situ performance of the building fabric of passive houses. Hence, this paper explores the applicability of non-destructive techniques—heat flux meter (HFM) and quantitative infrared thermography (QIRT)—for assessing the gap between the predicted and actual thermal transmittance of passive house façades under steady-state conditions in the Mediterranean climate. Firstly, the suitability of in situ non-destructive techniques was checked in an experimental mock-up, and, subsequently, a detached house was tested in the real built environment. The findings revealed that both Non-Destructive Testing (NDT) techniques allow for the quantification of the gap between the design and the actual façades U-value of a new passive house before its operational stage. QIRT was faster than the HFM technique, although the latter was more accurate. The results will help practitioners to choose the most appropriate method based on environmental conditions, execution of the method, and data analysis.

Economic Assessment of Solar-Powered Residential Battery Energy Storage Systems: The Case of Madeira Island, Portugal

This paper presents an economic assessment of introducing solar-powered residential battery energy storage in the Madeira Island electric grid, where only micro-production for self-consumption is currently allowed. The evaluation was conducted against six local micro-producers using one year of energy consumption and solar photovoltaic production measurements and two distinct storage control strategies. Several inverter sizes and storage capacities were considered based on the six micro-producers’ consumption and production profiles. The results were then analyzed concerning year-long simulations and a projection for the next ten years. To this end, several indicators were assessed, including self-consumption, profit per Euro invested, number of cycles and storage degradation. The results obtained show that, despite the benefits of storage to increase the self-consumption rates, considerable drops in the storage prices are still necessary to achieve profitability during these devices’ lifetime. Furthermore, our results also highlight a very interesting trade-off between self-consumption, pre-charge and profitability, in a sense that higher levels of pre-charge increase the chances of reaching profitability even though this will imply considerable drops in the levels of self-consumption.

Analysis of potential fuel savings, economic and environmental effects of improved biomass cookstoves in rural Ethiopia

Unsustainable utilization of solid biomass fuels with inefficient traditional cookstoves has long been a major challenge to ensuring energy and environmental security in Ethiopia. Against the backdrop of this problem, several models of improved biomass cookstoves (ICSs) have been developed and distributed in the country. Yet, little is known about the effect of these ICSs on household’s fuelwood consumption and the environment. The aim of this study was to examine the potential woodfuel savings, economic and environmental effects of three ICSs (Mirt, Gonziye, and Tikikil) in rural Ethiopia from a cross-sectional study of 605 sample households and direct energy consumption measurements in four rural districts. Inferential statistics and cost-benefit analysis were used to analyse the data. The results showed that compared with the traditional open fire tripod; the use of ICSs could reduce household’s fuelwood consumptions on average by 1.72–2.08 tons per household per year. These fuelwood savings translate to potential emissions reductions of 2.82–3.43 tCO2e per stove per year. The results from the cost-benefit analysis (CBA) indicated that investment in these ICSs could provide a net economic benefit of ETB 7204 to 10,381 (US$ 265 to 382) during the 2–5 years lifespan of the stoves. The benefit-cost ratios of these ICSs were calculated between 16.5:1 and 35.0:1. The implication is that promoting the use of Mirt, Gonziye and Tikikil stoves is a viable option and an essential component of the strategy for improving the energy-efficiency and well-being of rural communities while also contributing to the sustainable utilization of biomass resources, and mitigation of climate change in Ethiopia and beyond.

USE OF COMPUTER SIMULATION FOR OPTIMIZATION OF ENERGY CONSUMPTION IN THE MANUFACTURING PROCESS

This article provides information on using computer simulation to optimise energy consumption in manufacturing. Simulation of energy consumption in operation is always performed to analyse large amounts of data. Results of computer simulation offer the possibility to analyse different scenarios of production or use of machines. Each of the variants brings different scenarios to optimise energy use in order to reduce costs and improve the operation. The article also describes the sequence of steps that a user can take to create a quality simulation model. At the same time, there are graphical examples of energy consumption measurements made during simulation runs.

Optimization of energy consumption and daylight performance in residential building regarding windows design in hot and dry climate of Isfahan

The design of windows can provide the proper lighting of the interior and create comfortable conditions to increase the efficiency of the building. Furthermore, in designing building façade articulation, it is important to consider the projection and indentation, therein. This study aimed to evaluate the optimum parameters of the window by measuring energy consumption and daylight quality in residential buildings. A room with a constant window-to-wall ratio of 30% and different windows angles with horizontal and vertical rotation around the orthogonal axes to the inner and outer edges of the wall in all four cardinal directions, with the hot and dry climate of Isfahan as the case sample was selected, and daylighting and energy were simulated for all situations. Considering the criteria of daylight and annual energy consumption as output variables window angle from inner-outer and outer-middle in plane mode the most optimized design options are south and west orientation with 4.81 and 1.6% energy conserve, and inner-outer angle in cross-section for east and north orientation with 3.71 and 3.49%, respectively. Low-emissivity glass performed better with a mean of 2.78% of total energy storage in optimal window angles and the southern direction window with 21% total energy consumption has been the most prominent.

Energy consumption and efficiency measures in the Portuguese food processing industry

Simple energy surveys and audits were performed in 60 processing industries of meat, dairy, horticultural and bread and pastry products, located in the North, Center, and Alentejo regions of Portugal. The number of refrigeration chambers, building infrastructure, and energy consumptions of the equipment used in the manufacturing processes were evaluated. The energy consumption of different manufacturing processes of regional food products were compared. The study aims to present several measures and best practices for the improvement of energy efficiency of the food sector. The implementation of simple and very cost-effective transversal electricity savings measures such as awareness and/or training of operators, proper maintenance, and monitoring tasks, can benefit this sector. The tailored energy efficiency measures by sector are discussed. These energy efficient practice measures can offer savings at several levels, increasing productivity and competitiveness and improving the environmental impact, and thus the global sustainability of the Portuguese food sector. Practical applications The adoption of efficiency measures by SMEs provides them the necessary instruments to become more competitive and dynamic in the market, due to the reduction of the energy costs. This condition allows funds to be redirected to areas such as logistics, ensuring an expansion to international markets. This paper presents several measures of energy efficiency, many of which require small investments. The objective of this study is to provide a reference guide, with the purpose of qualifying SMEs for the adoption of strategies to increase their competitiveness, productivity, and efficiency.