Implicit sensing of building occupancy count with information and communication technology data sets

Occupancy count, i.e., the number of people in a space or building, is becoming an increasingly important measurement to model, predict, and minimize operational energy consumption. Explicit, hardware-based, occupancy counters have been proposed but wide scale adoption is limited due to the cost and invasiveness of system implementation. As an alternative approach, researchers propose using data from existing information and communication technology (ICT) systems to infer occupancy counts. In the reported work, three different data streams, security access data, wireless connectivity data, and computer activity data, from ICT systems in a medium sized office building were collected and compared to the counts of a commercially available occupancy counter over 59 working days. The occupancy counts from the ICT systems are compared to the commercial counter with and without calibration to determine the ability of the data sets to measure occupancy. Various transformations were explored as calibration techniques for the ICT data sets. Training sets of 24, 48, and 120 hours were employed to determine how long an external calibration system would need to be installed. The analysis found that calibration is required to provide accurate counts. While each ICT data set provides similar magnitudes and time series behavior, incorporating all three data streams in a two layer neural network with 1 week of training data provides the most accurate estimates against 5 performance metrics. Whilst 1 week of data provides the best results, 24 hours is sufficient to develop similar levels of performance

Modelling of a real CO2 booster installation and evaluation of control strategies for heat recovery applications in supermarkets

[EN] This paper compares and quantifies the energy, environmental and economic benefits of various control strategies recovering heat from a CO2 booster system in a supermarket for space heating with the purpose of understanding its potential for displacing natural gas fuelled boilers. A theoretical steady-state model that simulates the behaviour of the CO2 system is developed and validated against field measurements obtained from an existing refrigeration system in a food-retail building located in the United Kingdom. Five heat recovery strategies are analysed by modifying the mass flow and pressure level in the condenser. The model shows that a reduction of 48% in natural-gas consumption is feasible by the installation of a de-superheater and without applying any advanced operating strategy. However, the CO2 system can fully supply the entire space-heating requirements by adopting alternative control strategies, albeit by penalising the coefficient of performance (COP) of the compressor. Results show that the best energy strategy can reduce total consumption by 32%, while the best economic strategy can reduce costs by 6%. Findings from this work suggest that heat recovery systems can bring substantial benefits to improve the overall efficiency of energy-intensive buildings; nevertheless trade-offs need to be carefully considered and analysed on a site by site basis before embarking on such initiatives.This research was supported by funds provided via the Imperial-Sainsbury's Supermarkets Ltd. partnership. This work also was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) [grant number EP/P004709/1]. Emilio J. Sarabia gratefully acknowledges financial support from Universitat Politecnica de Valencia Fellowship. Data supporting this publication can be obtained on request from [email protected] Escrivà, EJ.; Acha, S.; Le Brun, N.; Soto Francés, VM.; Pinazo Ojer, JM.; Markides, C.; Shah, N. (2019). Modelling of a real CO2 booster installation and evaluation of control strategies for heat recovery applications in supermarkets. International Journal of Refrigeration. 107:288-300. https://doi.org/10.1016/j.ijrefrig.2019.08.005S28830010

Obras en apoyo a la instrucción y adiestramiento: Diseño y desarrollo de un polígono de combate en zonas urbanizadas

El objetivo del presente trabajo es el del diseño y concepción de un polígono de combate en población para poder ubicarlo en el campo de maniobras de la Isleta (Las Palmas de Gran Canaria), abarcando todas las fases que se contemplan en un proyecto de obra. Con ello se busca alcanzar la doble finalidad que persigue este trabajo, el cual no solo consta del diseño como tal, sino también que las unidades de ingenieros se instruyan a través de la construcción del polígono para que posteriormente otras unidades puedan ser adiestradas en él.<br /

Estabilización de una clase de sistemas no lineales: aplicación a un generador síncrono.

En este trabajo se propone un algoritmo de control basado en un observador no lineal para estabilizar una clase de sistemas no lineales observables para toda entrada. la aplicación de este algoritmo se lleva a cabo sobre un modelo reducido de un generador síncrono. Resultados en simulación son presentados para mostrar la eficiencia de este algoritmo

Elementos no-lineales en circuitos eléctricos, y procesos iterativos

Este documento trata sobre la solución iterativa requerida en problemas donde se tiene elementos no-lineales en una red eléctrica

Abaroa ta Babesa : iru ataletan / Arriolatar Xalbador apaizak gaztelaniz egindako antzerkiya ; eta Beobide'tar Joane Marik euzkeratua.

Dialecto : texto en euskera central -- guipuzcoanoS. XX -- Aroa : azken euskara modernoaEuskalkia : erdialdekoa -- gipuzkeraXX. md. -- Aroa : azken euskara modernoaDigitalización Vitoria-Gasteiz Archivos y Bibliotecas Junio 1995 19-3