scholarly journals Consumption Optimization in an Office Building Considering Flexible Loads and User Comfort

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 593 ◽  
Author(s):  
Mahsa Khorram ◽  
Pedro Faria ◽  
Omid Abrishambaf ◽  
Zita Vale
Keyword(s):  
Optimization Algorithm ◽  
Electricity Consumption ◽  
Office Building ◽  
Air Conditioners ◽  
Starting Point ◽  
Flexible Loads ◽  
The Difference ◽  
Operation Cycle ◽  
Building Operation ◽  
User Comfort

This paper presents a multiperiod optimization algorithm that is implemented in a Supervisory Control and Data Acquisition system. The algorithm controls lights and air conditioners as flexible loads to reduce the consumption and controls a dishwasher as a deferrable load to implement the load shifting. Several parameters are considered to implement the algorithm for several successive periods in a real building operation. In the proposed methodology, optimization is done regarding user comfort, which is modeled in the objective function related to the indoor temperature in each room, and in the constraints in order to prevent excessive power reduction, according to users’ preferences. Additionally, the operation cycle of a dishwasher is included, and the algorithm selects the best starting point based on the appliance weights and power availability in each period. With the proposed methodology, the building energy manager can specify the moments when the optimization is run with consideration of the operational constraints. Accordingly, the main contribution of the paper is to provide and integrate a methodology to minimize the difference between the actual and the desired temperature in each room, as a measure of comfort, respecting constraints that can be easily bounded by building users and manager. The case study considers the real consumption data of an office building which contains 20 lights, 10 ACs, and one dishwasher. Three scenarios have been designed to focus on different functionalities. The outcomes of the paper include proof of the performance of the optimization algorithm and how such a system can effectively minimize electricity consumption by implementing demand response programs and using them in smart grid contexts.

scholarly journals Finite Pure Plane Strain Bending of Inhomogeneous Anisotropic Sheets

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Sergei Alexandrov ◽  
Elena Lyamina ◽  
Yeong-Maw Hwang
Keyword(s):  
Plane Strain ◽  
Yield Criterion ◽  
Large Strains ◽  
Rigid Plastic ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Starting Point ◽  
The Difference ◽  
Inside Radius ◽  
Elastic Unloading

The present paper concerns the general solution for finite plane strain pure bending of incompressible, orthotropic sheets. In contrast to available solutions, the new solution is valid for inhomogeneous distributions of plastic properties. The solution is semi-analytic. A numerical treatment is only necessary for solving transcendent equations and evaluating ordinary integrals. The solution’s starting point is a transformation between Eulerian and Lagrangian coordinates that is valid for a wide class of constitutive equations. The symmetric distribution relative to the center line of the sheet is separately treated where it is advantageous. It is shown that this type of symmetry simplifies the solution. Hill’s quadratic yield criterion is adopted. Both elastic/plastic and rigid/plastic solutions are derived. Elastic unloading is also considered, and it is shown that reverse plastic yielding occurs at a relatively large inside radius. An illustrative example uses real experimental data. The distribution of plastic properties is symmetric in this example. It is shown that the difference between the elastic/plastic and rigid/plastic solutions is negligible, except at the very beginning of the process. However, the rigid/plastic solution is much simpler and, therefore, can be recommended for practical use at large strains, including calculating the residual stresses.

scholarly journals Determination of synchronous generator nonlinear model parameters based on power rejection tests using a gradient optimization algorithm

2017 ◽  
Vol 65 (4) ◽  
pp. 479-488 ◽  
Author(s):  
A. Boboń ◽  
A. Nocoń ◽  
S. Paszek ◽  
P. Pruski
Keyword(s):  
Parameter Estimation ◽  
Objective Function ◽  
Optimization Algorithm ◽  
Least Squares Method ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Model Parameters ◽  
State Variables ◽  
Starting Point ◽  
Gradient Optimization

AbstractThe paper presents a method for determining electromagnetic parameters of different synchronous generator models based on dynamic waveforms measured at power rejection. Such a test can be performed safely under normal operating conditions of a generator working in a power plant. A generator model was investigated, expressed by reactances and time constants of steady, transient, and subtransient state in the d and q axes, as well as the circuit models (type (3,3) and (2,2)) expressed by resistances and inductances of stator, excitation, and equivalent rotor damping circuits windings. All these models approximately take into account the influence of magnetic core saturation. The least squares method was used for parameter estimation. There was minimized the objective function defined as the mean square error between the measured waveforms and the waveforms calculated based on the mathematical models. A method of determining the initial values of those state variables which also depend on the searched parameters is presented. To minimize the objective function, a gradient optimization algorithm finding local minima for a selected starting point was used. To get closer to the global minimum, calculations were repeated many times, taking into account the inequality constraints for the searched parameters. The paper presents the parameter estimation results and a comparison of the waveforms measured and calculated based on the final parameters for 200 MW and 50 MW turbogenerators.

scholarly journals In-situ Desaturation Tests by Electrolysis for Liquefaction Mitigation

2021 ◽  
Author(s):  
Runze Chen ◽  
Yumin Chen ◽  
Hanlong Liu ◽  
Kunxian Zhang ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Minimum Degree ◽  
Electricity Consumption ◽  
Potential Method ◽  
Economic Benefits ◽  
Degree Of Saturation ◽  
Test Results ◽  
Liquefaction Resistance ◽  
The Difference ◽  
Maximum And Minimum Degree

Electrolytic desaturation is a potential method for improving the liquefaction resistance of the liquefiable foundation by reducing the soil saturation. In this study, in-situ desaturation tests were performed to investigate the resistivity of soil at different depth and the water level of the foundation under different current. The test results show that at constant currents of 1 A (Ampere, unit of the direct current), 2 A and 3 A, the saturation of the treated foundation reached 87%, 83% and 80%. During the electrolysis process, the generated gas migrates vertically and horizontally under the influence of buoyancy and gas pressure. In the end of electrolysis, the gas inside the sand foundation basically migrates vertically only. The higher current intensity employed for electrolysis will affect the uniformity and stability of the gas. At constant currents of 1 A, 2 A and 3 A, the difference between the maximum and minimum degree of saturation in the treated foundation was 14%, 18% and 19%; and after electrolysis halted for 144 h, the saturation in the treated foundation was 90%, 85% and 87%. The electricity consumption analysis indicates that the desaturation method has excellent economic benefits in the treatment of saturated sand foundations.

scholarly journals Silent and a audible stereotypes: The constitution of "ethnic character" in Serbian epic poetry

2005 ◽  
pp. 105-120 ◽  
Author(s):  
Gordana Djeric
Keyword(s):  
Explanatory Power ◽  
Mental Image ◽  
Epic Poetry ◽  
National Character ◽  
The Other ◽  
Relevant Feature ◽  
Explanatory Relevance ◽  
Starting Point ◽  
The Difference ◽  
Epic Poems

The article deals with the explanatory relevance of the concept of stereotype in one of its original meanings - as a "mental image". This meaning of the term is the starting point for further differentiations, such as: between linguistic and behavioral stereotypes (in the sense of nonverbal, expected responses); universal and particular stereotypes; self representative and introspective stereotypes; permanent and contemporary stereotypes; and finally, what is most important for our purposes, the difference between silent and audible stereotypes. These distinctions, along with the functions of stereotype, are discussed in the first part of the paper. In the second part, the relations of silent and audible stereotypes are tested against the introduction of "innovative vocabularies" in popular lore. In other words, the explanatory power of this differentiation is checked through an analysis of unconventional motives in Serbian epic poems. The goal of the argument is to clarify the procedure of self creation of masculinity as a relevant feature of the "national character" through "tactic games" of silent and audible stereotypes. The examination of these "poetic strategies" serves a twofold purpose: to illustrate the process of constructing particular features of the "ethno type", on one hand, and to check hypotheses and models which are taken as frameworks in analyzing stereotypes, on the other.

scholarly journals El reconocimiento del perjuicio ecológico en derecho francés

Bioderecho.es ◽  
2019 ◽  
Author(s):  
Chahinaze Sarah Hasnaoui
Keyword(s):  
Environmental Damage ◽  
Oil Slick ◽  
The People ◽  
Starting Point ◽  
The Difference ◽  
Oil Tanker

Se analiza el reconocimiento del perjuicio ecológico en Francia como resultado de un largo proceso deconstrucción jurisprudencial y doctrinal. Para ello se toma como punto de partida el desastre del Erika, un petrolero cargado de 31 000 toneladas de fuel que se partió en las aguas bretonas, causando una marea negra que alcanzó más de 400 kilómetros de costafrancesa. Se estudian las distintas decisiones de los tribunales implicados en el juicio de esta catástrofe y las distinciones que se establecen entre perjuicios subjetivos (intereses patrimoniales y extrapatrimoniales de las personas) y objetivos (daños al ambiente natural). The recognitionof the ecologic damage in France is analysed as a result longprocessof jurisprudential and doctrinal construction. For that, the Erika disasteris taken as a starting point, an oil tanker loaded with 31,000 tons of fuel which broke offin Breton waters, causing an oil slick which affected more than 400 kilometres of French coast.The different court’sdecision involved in the trial of this catastrophe, as well as the difference established between subjective damages (patrimonial and extra patrimonialinterest of the people) and objective damage (environmental damage)have been studied.

scholarly journals Time series data measurement on electricity consumption for selected domestic appliances in typical terrace house of Malaysia

2019 ◽  
Vol 8 (3) ◽  
pp. 1144-1153
Author(s):  
Naja Aqilah ◽  
Sheikh Ahmad Zaki Shaikh Salim ◽  
Aya Hagishima ◽  
Nelidya Md Yusoff ◽  
Fitri Yakub
Keyword(s):  
Time Series Data ◽  
Electricity Consumption ◽  
Hot Water ◽  
Series Data ◽  
Small Contribution ◽  
Washing Machine ◽  
Air Conditioners ◽  
Power Characteristics ◽  
Data Measurement ◽  
Domestic Appliances

This paper describes the pattern of electricity consumption from total and selected domestic appliances at a typical terrace house in Malaysia. The measured appliances can be classified into four groups on the basis of pattern of use which are ‘standby’ (TV), ‘active’ (massage chair, charger of hand phone, laptop and power bank, washing machine, air-conditioners, iron, standing fan, shower heaters, rice cooker, toaster, microwave), ‘cold’ (refrigerator) and ‘cold and hot’ (water dispenser). The major contribution of monthly electricity consumption comes from ‘cold’ appliances that consume 118.8 kWh/month followed by ‘active’ appliances that consume 87.8 kWh/month and ‘cold and hot’ appliance with 52.5 kWh/month. ‘Standby’ appliances shown a small contribution to the total electricity with 0.9 kWh/month. The amount of energy consumed depends on time-of-use, power characteristics of particular appliances as well as occupancy period.

scholarly journals Carbon footprint estimate in the primary wood processing industry in El Salto, Durango

2020 ◽  
Vol 27 (1) ◽  
pp. 127-142
Author(s):  
Pedro Meza-López ◽  
◽  
Mayra K. Trujillo-Delgado ◽  
Alan U. Burciaga-Álvarez ◽  
Ricardo de la Cruz-Carrera ◽  
...  
Keyword(s):  
Carbon Footprint ◽  
Ghg Emissions ◽  
Electricity Consumption ◽  
Wilcoxon Test ◽  
Organizational Boundaries ◽  
Activity Data ◽  
Processing Industry ◽  
Wood Processing ◽  
The Difference ◽  
L1 And L2

Introduction: The primary wood processing industry releases greenhouse gases (GHGs); their mitigation involves measuring the carbon footprint.Objective: To estimate the carbon footprint of two forestry companies dedicated to the primary transformation of wood.Materials and methods: Companies established as organizational boundaries L1 and L2 have two (Q1 and Q2) and one (D) sawmill, respectively. The operational limits were A1 (direct emissions from fossil fuel consumption), A2 (indirect emissions from electricity consumption) and A3 (emission sources not owned by L1 and L2). GHG emissions were calculated in two annuities with the method of using documented activity data and emission factors level 1. The annuities were compared with the Student’ t-test and Wilcoxon test, and the sawmills with the Kruskal-Wallis test.Results and discussion: The estimated carbon footprint for L1 was 480.06 tCO2e·year-1, where A1, A2 and A3 represented 29.32 %, 14.59 % and 56.09 %, respectively. L2 had a footprint of 230.56 tCO2e·year-1 of which 9.39 %, 11.78 % and 78.83 % corresponded to the categories A1, A2 and A3, respectively. The cumulative uncertainty was within a fair range of accuracy (±25 %). Only the direct GHG emissions between L1 annuities were statistically different (P < 0.05). Mechanical technology made the difference in GHG emissions among sawmills (P < 0.05).Conclusions: The carbon footprint is inherent to the energy used; energy management ensures the mitigation of GHG emissions.

scholarly journals On the self-induction of electric currents in a thin anchor-ring

1912 ◽  
Vol 86 (590) ◽  
pp. 562-571 ◽  
Keyword(s):  
Cross Section ◽  
Circular Cross Section ◽  
The Self ◽  
Electric Currents ◽  
Fourth Term ◽  
Starting Point ◽  
Axis Of Symmetry ◽  
The Difference ◽  
Circular Axis ◽  
Mutual Induction

In their useful compendium of "Formulæ and Tables for the Calculation of Mutual and Self-Inductance," Rosa And Cohen remark upon a small discrepancy in the formulæ given by myself and by M. Wien for the self-induction of a coil of circular cross-section over which the current is uniformly distributed . With omission of n , representative of the number of windings, my formula was L = 4 πa [ log 8 a / ρ - 7/4 + ρ 2 /8 a 2 (log 8 a / ρ + 1/3) ], (1) where ρ is the radius of the section and a that of the circular axis. The first two terms were given long before by Kirchhoff. In place of the fourth term within the bracket, viz., +1/24 ρ 2 / a 2 , Wien found -·0083 ρ 2 / a 2 . In either case a correction would be necessary in practice to take account of the space occupied by the insulation. Without, so far as I see, giving a reason, Rosa and Cohen express a preference for Wien's number. The difference is of no great importance, but I have thought it worth while to repeat the calculation and I obtain the same result as in 1881. A confirmation after 30 years, and without reference to notes, is perhaps almost as good as if it were independent. I propose to exhibit the main steps of the calculation and to make extension to some related problems. The starting point is the expression given by Maxwell for the mutual induction M between two neighbouring co-axial circuits. For the present purpose this requires transformation, so as to express the inductance in terms of the situation of the elementary circuits relatively to the circular axis. In the figure, O is the centre of the circular axis, A the centre of a section B through the axis of symmetry, and the position of any point P of the section is given by polar co-ordinates relatively to A, viz.

Peruvian small and medium-sized enterprises and COVID-19: Time for a new start!

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Susanne Durst ◽  
Mariano Martin Genaro Palacios Acuache ◽  
Guido Bruns
Keyword(s):  
Latin America ◽  
Crisis Management ◽  
Structured Interviews ◽  
Content Type ◽  
Qualitative Research Design ◽  
The People ◽  
Starting Point ◽  
The Difference ◽  
Insight Into

Purpose Crises of any type have become an integral part of business activity and responses to them could make the difference between survival and failure. This applies in particular to small and medium-sized enterprises (SMEs). Taking the coronavirus (COVID-19) pandemic as a starting point, this study aims to investigate how Peruvian SMEs have been coping with COVID-19 so far. Based on that a conceptual framework is proposed which highlights the practice of SMEs trying to deal with a new type of crisis. Design/methodology/approach The study is based on an exploratory qualitative research design involving 25 semi-structured interviews conducted in Peruvian SMEs. Findings The findings demonstrate how the Peruvian firms studied to adapt to the new situation and initiate responses to increasing the chance of survival. Furthermore, the role of the companies’ decision-makers, as well as the role of crisis management and other related approaches in the companies are shown. Research limitations/implications The paper expands the underdeveloped body of knowledge regarding crisis management in Latin America in general and crisis management in SMEs by providing insight into how Peruvian SMEs perceive and adapt to the COVID-19 pandemic. Practical implications The findings presented in this paper have implications for both managers and managerial staff of SMEs but also for the people in charge of the curricula at universities and other teaching-focused institutes. Originality/value To the authors’ knowledge, this is the first empirical study of crisis management on the impacts of COVID-19 with a dedicated focus on SMEs from Latin America. It provides fresh insight into current reactions to the Pandemic.

A combined effective time series model based on clustering and whale optimization algorithm for forecasting smart meters electricity consumption

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Medhat Abd el Azem El Sayed Rostum ◽  
Hassan Mohamed Mahmoud Moustafa ◽  
Ibrahim El Sayed Ziedan ◽  
Amr Ahmed Zamel
Keyword(s):  
Optimization Algorithm ◽  
Prediction Accuracy ◽  
Electricity Consumption ◽  
Whale Optimization Algorithm ◽  
Computational Time ◽  
Smart Meters ◽  
Content Type ◽  
Individual Level ◽  
Consumption Values ◽  
Whale Optimization

Purpose The current challenge for forecasting smart meters electricity consumption lies in the uncertainty and volatility of load profiles. Moreover, forecasting the electricity consumption for all the meters requires an enormous amount of time. Most papers tend to avoid such complexity by forecasting the electricity consumption at an aggregated level. This paper aims to forecast the electricity consumption for all smart meters at an individual level. This paper, for the first time, takes into account the computational time for training and forecasting the electricity consumption of all the meters. Design/methodology/approach A novel hybrid autoregressive-statistical equations idea model with the help of clustering and whale optimization algorithm (ARSEI-WOA) is proposed in this paper to forecast the electricity consumption of all the meters with best performance in terms of computational time and prediction accuracy. Findings The proposed model was tested using realistic Irish smart meters energy data and its performance was compared with nine regression methods including: autoregressive integrated moving average, partial least squares regression, conditional inference tree, M5 rule-based model, k-nearest neighbor, multilayer perceptron, RandomForest, RPART and support vector regression. Results have proved that ARSEI-WOA is an efficient model that is able to achieve an accurate prediction with low computational time. Originality/value This paper presents a new hybrid ARSEI model to perform smart meters load forecasting at an individual level instead of an aggregated one. With the help of clustering technique, similar meters are grouped into a few clusters from which reduce the computational time of the training and forecasting process. In addition, WOA improves the prediction accuracy of each meter by finding an optimal factor between the average electricity consumption values of each cluster and the electricity consumption values for each one of its meters.

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