694 research outputs found
Sensitivity Function Trade-offs for Networks with a String Topology
We present two sensitivity function trade-offs that apply to a class of
networks with a string topology. In particular we show that a lower bound on
the H-infinity norm and a Bode sensitivity relation hold for an entire family
of sensitivity functions associated with growing the network. The trade-offs we
identify are a direct consequence of growing the network, and can be used to
explain why poorly regulated low frequency behaviours emerge in long vehicle
platoons even when using dynamic feedback
Robust Scale-Free Synthesis for Frequency Control in Power Systems
The AC frequency in electrical power systems is conventionally regulated by
synchronous machines. The gradual replacement of these machines by asynchronous
renewable-based generation, which provides little or no frequency control,
increases system uncertainty and the risk of instability. This imposes hard
limits on the proportion of renewables that can be integrated into the system.
In this paper we address this issue by developing a framework for performing
frequency control in power systems with arbitrary mixes of conventional and
renewable generation. Our approach is based on a robust stability criterion
that can be used to guarantee the stability of a full power system model on the
basis of a set of decentralised tests, one for each component in the system. It
can be applied even when using detailed heterogeneous component models, and can
be verified using several standard frequency response, state-space, and circuit
theoretic analysis tools. Furthermore the stability guarantees hold
independently of the operating point, and remain valid even as components are
added to and removed from the grid. By designing decentralised controllers for
individual components to meet these decentralised tests, every component can
contribute to the regulation of the system frequency in a simple and provable
manner. Notably, our framework certifies the stability of several existing
(non-passive) power system control schemes and models, and allows for the study
of robustness with respect to delays.Comment: 10 pages, submitte
Performance tradeoffs of dynamically controlled grid-connected inverters in low inertia power systems
Implementing frequency response using grid-connected inverters is one of the
popular proposed alternatives to mitigate the dynamic degradation experienced
in low inertia power systems. However, such solution faces several challenges
as inverters do not intrinsically possess the natural response to power
fluctuations that synchronous generators have. Thus, to synthetically generate
this response, inverters need to take frequency measurements, which are usually
noisy, and subsequently make changes in the output power, which are therefore
delayed. This paper explores the system-wide performance tradeoffs that arise
when measurement noise, power disturbances, and delayed actions are considered
in the design of dynamic controllers for grid-connected inverters. Using a
recently proposed dynamic droop (iDroop) control for grid-connected inverters,
which is inspired by classical first order lead-lag compensation, we show that
the sets of parameters that result in highest noise attenuation, power
disturbance mitigation, and delay robustness do not necessarily have a common
intersection. In particular, lead compensation is desired in systems where
power disturbances are the predominant source of degradation, while lag
compensation is a better alternative when the system is dominated by delays or
frequency noise. Our analysis further shows that iDroop can outperform the
standard droop alternative in both joint noise and disturbance mitigation, and
delay robustness
The effects of hypnosis on flow states and three-point shooting performance in basketball players.
This study examined the effects of hypnosis on flow states and three-point shooting performance in 5 collegiate basketball players. The investigation uti- lized an ideographic single-subject multiple baselines across subjects design combined with a procedure that monitors the internal experience of the par- ticipants (Wollman, 1986). The method of intervention utilized in this study involved relaxation, imagery, hypnotic induction, hypnotic regression, and trigger control procedures. The results indicated that all five participants in- creased both their mean basketball three-point shooting performance and their mean flow scores from baseline to intervention. There were no overlapping data points between the baseline and intervention for either performance or flow state. Additionally, each participant indicated that they had felt the inter- vention was useful in keeping them confident, relaxed, and calm. These re- sults support the hypothesis that a hypnosis intervention can improve three- point shooting performance in basketball players and increase feelings and cognitions that are associated with flow
Utilizing the CDC T-dap Educational Material to Increase Parental Consent of T-dap Vaccination Rates Among Children 11-14 Years
Background:The T-dap vaccine is vital to combating vaccine-preventable diseases. T-dap vaccine can prevent tetanus, diphtheria, and pertussis (Centers for Disease Control and Prevention [CDC], 2021). Therefore, providers must identify and educate parents whose child is unvaccinated with the T-dap vaccine. If an increase in unvaccinated children continues to rise, there is risk for a resurgence of vaccine-preventable diseases and potential increase in deaths related to these infectious diseases (Bowling, 2018, p. 128).
Purpose: The purpose of this DNP project was to implement an educational session targeting parents of children aged 11-14 in a pediatric clinic in an urban area utilizing the CDC educational material to increase parental consent to the T-dap vaccination.
Methods: This quality improvement (QA) project utilized the CDC T-dap material to conduct an educational session for parents of children aged 11-14 years. The Parent Attitudes about Childhood Vaccines (PACV) survey measured the project\u27s primary outcome, which includes improving knowledge on the importance of T-dap. The pre-survey was given before the educational session, and a post-survey via telephone within one week.
Results: The results were clinically significant in identifying vaccine-hesitant parents, analysis showed a slight improvement in patient pre-post responses.
Conclusion: The results showed the need for educational program in the pediatric clinic to increase knowledge to improve parental consen
“I miss you, I forget you, I love you again”: The construction of love in Argentinian young adult literature
Recociendo que para analizar objetos literarios es necesario desbordar los límites del texto, este artículo apunta a indagar en las mediaciones existentes entre la literatura y el entramado social, es decir, los rasgos específicos del texto literario y la red de relaciones de la que es parte. En particular, se centrará en la literatura juvenil romántica argentina para preguntarse cómo está configurado este campo, qué matrices discursivas en torno del amor se construyen y cómo es leída y apropiada por parte del público lector juvenil. Para ello se analizarán los libros S.O.S. Tengo mi primera cita (Dritsos, 2014) y Diario de una ruptura (Dritsos, 2016).En primera instancia, se contextualizarán los libros seleccionados dentro del mercado editorial argentino y se recuperará la trayectoria de su autora para dar cuenta de sus condiciones sociales de producción. En segundo lugar, se desglosará el análisis de ambos libros en torno a los modos en que se construye el amor a partir de dos matrices discursivas: el amor romántico y el amor contingente. Finalmente, se reconstruirán los espacios por donde han circulado estos libros, así como también los modos en que han sido leídos y apropiados en Argentina.When we analyze literary objects, it is necessary to go beyond the limits of the text. This article aims to look at the mediations between the literary and social frameworks; that is to say, the specific features of the literary text and the relationship network to which it belongs. We shall focus specifically on Argentinian romantic young adult literature to reflect on how the literary field is built, what discursive matrices on love are constructed, and how it is read by young readers. To do so, Georgina Dritsos’ books S.O.S. Tengo mi primera cita (2014) and Diario de una ruptura (2016) shall be analyzed. First of all, these two books shall be set within to the Argentinian editorial market as well as the author’s literary career will be mentioned. Secondly, the ways in which love is constructed in both books will be analyzed following two discursive matrices: romantic love and contingent love. Finally, the places where the books have circulated and the ways they have been read in Argentina it shall be summarized.Fil: Pates, Giuliana Antonela. Universidad Nacional de La Plata. Facultad de Periodismo y Comunicación Social. Centro de Investigación en Problemáticas Socio-simbólicas Latinoamericanas "Aníbal Ford"; Argentin
What Kinds of Research Information Do Communications Practitioners Need?
Listen to a communicator attending any conference related to their work and one could conclude that the mission of the average communications office has become: Do more, do it better, do it with LESS!! Not only on less money...but less time! Now, if that isn\u27t the perfect recipe for frustration, it would be hard to find one. Unfortunately, it seems to be a feeling shared by many
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