InterPhases Solar (United States)

We consider a classical problem of decoupling the output of a linear time-invariant system from the disturbances. It is well known that if certain decoupling conditions are met, there exists a linear state-feedback control that decouples the output from the disturbance. However, the control law obtained for disturbance decoupling in continuous time is usually implemented digitally leading to ineffective decoupling. Typically, one redesigns the decoupling control considering a discrete-time linear system obtained by using a sample and hold mechanism for control with uniform sampling. In contrast, here, we develop a self-triggered control strategy that ensures that the norm of the output of the system under the disturbance input remains bounded within a specified tolerance for all time. Furthermore, a heuristic procedure is provided to increase the time between successive triggers, thus reducing the number of triggers.

Accurate short-term forecasts of daily reference evapotranspiration (ET0) are essential for real-time irrigation scheduling. Many models rely on current and historical temperature data to estimate daily ET0. However, easily accessible temperature forecasts are relatively less reported in short-term ET0 forecasting. Furthermore, the accuracy of ET0 forecasting from different models varies locally and also across regions. We used five temperature-dependent models to forecast daily ET0 for a 7-day horizon in the North China Plain (NCP): the McCloud (MC), Hargreaves-Samani (HS), Blaney-Criddle (BC), Thornthwaite (TH), and reduced-set Penman–Monteith (RPM) models. Daily meteorological data collected between 1 January 2000 and 31 December 2014 at 17 weather stations in NCP to calibrate and validate the five ET0 models against the ASCE Penman–Monteith (ASCE-PM). Forecast temperatures for up to 7 d ahead for 1 January 2015–19 June 2021 were input to the five calibrated models to forecast ET0. The performance of the five models improved for forecasts at all stations after calibration. The calibrated RPM is the preferred choice for forecasting ET0 in NCP. In descending order of preference, the remaining models were ranked as HS, TH, BC, and MC. Sensitivity analysis showed that a change in maximum temperature influenced the accuracy of ET0 forecasting by the five models, especially RPM, HS, and TH, more than other variables. Meanwhile, the calibrated RPM and HS equations were better than the other models, and thus, these two equations were recommended for short-term ET0 forecasting in NCP.

El presente artículo es parte de la investigación doctoral titulada Cinema Planeta, Festiverd y Patagonia Eco Film Fest: Festivales de cine ambiental y su gestión. Una aproximación desde sus directores realizada por Peña (2021). Se busca comprender desde las voces de los directores de Cinema Planeta, Festiverd y Eco Film Fest, los significados atribuidos a la gestión en los festivales de cine ambiental desde la categoría emergente: Prácticas ambientales en los festivales de cine ambiental. La investigación se desarrolla dentro del Paradigma Cualitativo bajo el Enfoque Fenomenológico Interpretativo. Las prácticas ambientales de los festivales de cine no emergen simultáneamente. Todo lo contrario, aparecen según las necesidades de los festivales de cine ambiental. Se sustentan en una serie de subcategorías: huella de carbono, formato digital, paneles solares, estatuillas, 3R, entre otras. Se resalta una gestión ambiental antropocéntrica centrada en el hombre y la satisfacción de sus necesidades, más que en la propia naturaleza. Al mismo tiempo, destaca como una aplicación de principios ambientales basados en la preocupación y prevención. Apunta a la implementación de tecnologías más amigables con el ambiente. En el proceso se resalta el rol del director en la toma de decisiones gerenciales sustentables. Cada acción cuenta e involucra directamente al festival de cine ambiental. Se pone a prueba la proactividad en la dirección y gestión de un evento. Países como Argentina y México no desperdician la oportunidad de ser parte de este proceso que implica transformación desde la legislación.

Direction of arrival (DOA) estimation for multi-channel speech enhancement is a challenging problem. In this context, this paper proposes a new method for joint DOA estimation using a low complexity convolutional neural network (CNN) architecture. The spherical harmonic (SH) coefficients of the received speech signal are obtained from the spherical harmonics decomposition (SHD). The magnitude and phase features are extracted from these SH coefficients and combined as a single feature for training the CNN. A single CNN model is trained using these combined features in contrast to two CNN models used in earlier work. Both azimuth and elevation are then obtained for estimation of DOA from this single CNN. Extensive simulations are also conducted for the performance evaluation of the proposed low complexity CNN model. It is observed that the proposed CNN model provides robust DOA estimates at the various signal to noise ratios (SNR) and reverberation times with reduced computational complexity. Performance evaluated in terms of the gross error (GE) and run-time complexity also provides interesting results motivating the use of the proposed model in practical applications.

In this paper we introduce the Embedded Vision Engine (EVE), a novel vision accelerator designed to complement digital signal processors on low- and mid-level vision algorithms. We illustrate EVE's performance on three important mid-level vision functions, the Hough transform for circles, integral image and calculating the Rotation invariant Binary Robust Independent Elementary Feature (RBRIEF) descriptor. EVE can execute these functions 4 times faster than the state-of-the-art digital signal processor. With other vision functions accelerated 3–12X, the acceleration of these popular vision functions contribute to the application level speed up of 5x on common automotive vision applications. This demonstrates that EVE, while working at powers comparable to the power of a DSP core, can deliver significant boost in performance.

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Electrochemical growth of copper-indium-selenide (CIS) compounds is investigated, aimed at providing a non-vacuum large-area deposition method. CIS film formation is identified with cyclic voltammetry. Its growth, monitored with XRF, shows excellent composition and thickness uniformity. The results agree with SIMS profiles and XRD data, indicating conversion of initially formed binary phases to homogenous ternary compounds. They demonstrate that one can avail of thermodynamic reaction control to produce surprisingly stoichiometric CIS compositions over a wide range of process parameters. This outcome enables extending the benefits of industrial scale roll-to-roll electrodeposition to obtain widegap CIS PV absorbers on flexible foil.