Ryerson University

About: Ryerson University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Poison control. The organization has 7671 authors who have published 20164 publications receiving 394976 citations. The organization is also known as: Ryerson Polytechnical Institute & Ryerson Institute of Technology.

Towards safer interprofessional communication: constructing a model of "utility" from preoperative team briefings.

Abstract: “Improved team communication” is broadly advocated in the discourse on safety but rarely supported by a precise understanding of the relationship between specific communication practices and concrete improvements in collaborative work processes. We sought to improve such understanding by analyzing the discourse arising from structured preoperative team briefings among surgeons, nurses, and anesthesiologists prior to general surgery procedures. Analysis of observers' fieldnotes from 302 briefings yielded a two-part model of communicative “utility”, defined as the visible impact of communication on team awareness and behavior. “Informational utility” occurred when team awareness or knowledge was improved by provision of new information, explicit confirmation, reminders, or education. “Functional utility” represented direct communication – work connections: many briefings identified problems, prompting decision-making and follow-up actions. The crux of the model is an elaboration of the causal pathway betwee...

Short-Term Electric Load Forecasting Using Echo State Networks and PCA Decomposition

Abstract: In this paper, we approach the problem of forecasting a time series (TS) of an electrical load measured on the Azienda Comunale Energia e Ambiente (ACEA) power grid, the company managing the electricity distribution in Rome, Italy, with an echo state network (ESN) considering two different leading times of 10 min and 1 day. We use a standard approach for predicting the load in the next 10 min, while, for a forecast horizon of one day, we represent the data with a high-dimensional multi-variate TS, where the number of variables is equivalent to the quantity of measurements registered in a day. Through the orthogonal transformation returned by PCA decomposition, we reduce the dimensionality of the TS to a lower number $k$ of distinct variables; this allows us to cast the original prediction problem in $k$ different one-step ahead predictions. The overall forecast can be effectively managed by $k$ distinct prediction models, whose outputs are combined together to obtain the final result. We employ a genetic algorithm for tuning the parameters of the ESN and compare its prediction accuracy with a standard autoregressive integrated moving average model.

Electric Vehicle Charging Station With an Energy Storage Stage for Split-DC Bus Voltage Balancing

Abstract: This paper proposes a novel balancing approach for an electric vehicle bipolar dc charging station at the megawatt level, enabled by a grid-tied neutral-point-clamped converter. The study uses the presence of an energy storage stage with access to both of the dc buses to perform the complementary balance. It proposes a generic balancing structure that can achieve balance regardless the kind of energy storage system (ESS) employed. This is aiming to reduce the hardware requirements of the system and maximize the usage of the ESS, whose main function is to perform the energy management related tasks. To meet this purpose, a three-level dc–dc interface is employed, allowing to compensate the dc currents with a single ESS. Furthermore, in order to prevent the appearance of even-order harmonics in the input current during asymmetrical operation, an alternative switching sequence for the central converter is proposed. Results indicate that, without altering dramatically the charging process of the ESS, it is possible to cover the whole load scenario without the need of a balancing circuit. This allows the use of off-the-shelf products both for the rectifier and the fast chargers. In this paper, simulation and experimental results are presented to validate the proposed balancing strategy.