Secondary Frequency and Voltage Control of Islanded Microgrids via Distributed Averaging

In this work we present new distributed controllers for secondary frequency and voltage control in islanded microgrids. Inspired by techniques from cooperative control, the proposed controllers use localized information and nearest-neighbor communication to collectively perform secondary control actions. The frequency controller rapidly regulates the microgrid frequency to its nominal value while maintaining active power sharing among the distributed generators. Tuning of the voltage controller provides a simple and intuitive trade-off between the conflicting goals of voltage regulation and reactive power sharing. Our designs require no knowledge of the microgrid topology, impedances or loads. The distributed architecture allows for flexibility and redundancy, and eliminates the need for a central microgrid controller. We provide a voltage stability analysis and present extensive experimental results validating our designs, verifying robust performance under communication failure and during plug-and-play operation.Comment: Accepted for publication in IEEE Transactions on Industrial Electronic

Building Institutional Support for Undocumented and DACA-eligible College Students in Michigan

In 2017, the state of Michigan operated, and continues to operate, in an unstipulated policy environment related to undocumented students. There is no higher education commission or policy coordinating body in Michigan nor has the state legislature passed any legislation related to undocumented students or students who are DACA-eligible. Under this unstipulated policy environment, postsecondary institutions have the discretion to establish their own admissions policies and practices, including tuition and financial aid guidelines for undocumented students. Some institutions have stated their public support of these students through what they identify as inclusive and supportive institutional practices via their websites. However, these polices have created a nebulous environment which has created additional barriers for undocumented and DACA-eligible students trying to access postsecondary education. The lack of clear and consistent financial aid and admission policies across the state has resulted in a convoluted environment for undocumented and DACA-eligible students in applying to institutions. In this paper, we highlight how a group of undergraduate and graduate University of Michigan student researchers, both documented and undocumented, developed an instrument to analyze institutional policies related to in-state resident tuition, admission, financial aid, as well as the availability of dedicated student support services for undocumented and DACA-eligible students in the state of Michigan during the Fall of 2017. The data for this project has been turned into a website with updated (as of 2020) and available at https://uleadnet.org/mi-undocu-map

Development of a remotely activated field sprayer and evaluation of temperature and aeration on the longevity of Steinernema riobrave entomopathogenic nematodes for treatment of cattle fever tick-infested nilgai

A remotely activated field sprayer was developed for application of the entomopathogenic nematode, Steinerne-ma riobrave (Cabanillas, Poinar, and Raulston) for eradication of the southern cattle fever tick, Rhipicephalus microplus (Canestrini) infesting free-ranging nilgai (Boselaphus tragocamelus) in South Texas. The battery pow-ered sprayer is activated by sonic sensors that detect movement of nilgai through fence crossings. An onboard computer operates the sprayer pump and aerator that oxygenates the solution of nematodes. Several types of aeria-tion, agitation, and cooling were tested to prolong the viability of the nematodes in water. Continuous aeration extended the longevity of S. riobrave to more than two weeks as compared to cooling or intermittent agitation. The potential use of nematodes pathogenic to R. microplus dispensed by the remotely activated sprayer to infested nil-gai, and potentially white-tailed deer (Odocoileus virginianus), as part of integrated cattle fever tick eradication efforts is discussed

Schulrat Dr. Scheurer zum 70. Geburtstag

OpenWS-Transaction is an open source middleware that enables Web services to participate in a distributed transaction as prescribed by the WS-Coordination and WS-Transaction set of specifications. Central to the framework are the Coordinator and Participant entities, which can be integrated into existing services by introducing minimal changes to application code. OpenWS-Transaction allows transaction members to recover their original state in case of operational failure by leveraging techniques in logical logging and recovery at the application level. Depending on transaction style, system recovery may involve restoring key application variables and replaying uncommitted database activity. Transactions are assumed to be defined in the context of a BPEL process, although other orchestration alternatives can be used

The Starshine Satellite: From Concept to Delivery in Four Months

Engineers at the Naval Research Laboratory\u27s Naval Center for Space Technology (NCST) designed, built, and tested the Starshine satellite to meet Space Shuttle Hitchhiker Payload specifications. In a period of only four months after being provided the project requirements from the Starshine project director, Starshine was ready for delivery to the NASA Goddard Space Flight Center (GSFC) for STS 96. GSFC integrated the satellite with its Hitchhiker canister and installed it in the cargo bay of Space Shuttle Orbiter Discovery at the Kennedy Space Center. On May 27, 1999, Star shine went into orbit with Orbiter Discovery. On June 5, 1999, Starshine was deployed from the Hitchhiker canister into low Earth orbit. This paper describes the features of the design, analysis, and testing of the Starshine satellite that permitted its delivery in such a short time. The paper also describes the design and production of the spacecraft\u27s 878 mirrors and the polishing of those mirrors by 25,030 students in 18 countries, as well as the post-polishing protective coating of the finished mirrors. It will also describe the deployment of the satellite and early results of the tracking observations

Maximum Likelihood Estimation for Single Particle, Passive Microrheology Data with Drift

Volume limitations and low yield thresholds of biological fluids have led to widespread use of passive microparticle rheology. The mean-squared-displacement (MSD) statistics of bead position time series (bead paths) are either applied directly to determine the creep compliance [Xu et al (1998)] or transformed to determine dynamic storage and loss moduli [Mason & Weitz (1995)]. A prevalent hurdle arises when there is a non-diffusive experimental drift in the data. Commensurate with the magnitude of drift relative to diffusive mobility, quantified by a P\'eclet number, the MSD statistics are distorted, and thus the path data must be "corrected" for drift. The standard approach is to estimate and subtract the drift from particle paths, and then calculate MSD statistics. We present an alternative, parametric approach using maximum likelihood estimation that simultaneously fits drift and diffusive model parameters from the path data; the MSD statistics (and consequently the compliance and dynamic moduli) then follow directly from the best-fit model. We illustrate and compare both methods on simulated path data over a range of P\'eclet numbers, where exact answers are known. We choose fractional Brownian motion as the numerical model because it affords tunable, sub-diffusive MSD statistics consistent with typical 30 second long, experimental observations of microbeads in several biological fluids. Finally, we apply and compare both methods on data from human bronchial epithelial cell culture mucus.Comment: 29 pages, 12 figure

Translocation and deletion breakpoints in cancer genomes are associated with potential non-B DNA-forming sequences

Gross chromosomal rearrangements (including translocations, deletions, insertions and duplications) are a hallmark of cancer genomes and often create oncogenic fusion genes. An obligate step in the generation of such gross rearrangements is the formation of DNA double-strand breaks (DSBs). Since the genomic distribution of rearrangement breakpoints is non-random, intrinsic cellular factors may predispose certain genomic regions to breakage. Notably, certain DNA sequences with the potential to fold into secondary structures [potential non-B DNA structures (PONDS); e.g. triplexes, quadruplexes, hairpin/cruciforms, Z-DNA and single-stranded looped-out structures with implications in DNA replication and transcription] can stimulate the formation of DNA DSBs. Here, we tested the postulate that these DNA sequences might be found at, or in close proximity to, rearrangement breakpoints. By analyzing the distribution of PONDS-forming sequences within ±500 bases of 19 947 translocation and 46 365 sequence-characterized deletion breakpoints in cancer genomes, we find significant association between PONDS-forming repeats and cancer breakpoints. Specifically, (AT)n, (GAA)n and (GAAA)n constitute the most frequent repeats at translocation breakpoints, whereas A-tracts occur preferentially at deletion breakpoints. Translocation breakpoints near PONDS-forming repeats also recur in different individuals and patient tumor samples. Hence, PONDS-forming sequences represent an intrinsic risk factor for genomic rearrangements in cancer genomes

Calidad del servicio y su influencia en la satisfacción de los clientes del Banco Azteca en el distrito El Porvenir - 2017

El presente estudio se ha realizado con el propósito de determinar cómo influye la calidad del servicio en la satisfacción del cliente en el banco Azteca en el distrito El Porvenir. Se utilizó el diseño causa efecto, empleando la técnica de la encuesta y el cuestionario como instrumento, la muestra se obtuvo a partir de los clientes del Banco Azteca en el distrito El Porvenir. Los resultados de la investigación nos han permitido conocer influencia de la satisfacción de los clientes en cuanto a la calidad percibida en el Banco Azteca en el Distrito El Porvenir. De este modo se ha logrado conocer la relación significativa que existe entre la calidad del servicio y la satisfacción de los clientes; asimismo la influencia que genera la misma en los clientes del Banco Azteca en el distrito El Porvenir; y se concluye que la calidad del servicio presenta una influencia directa en la satisfacción del cliente, además de que en la mayoría de los casos los clientes se encuentran satisfechos con los servicios prestados, las instalaciones físicas, los elementos materiales y el cumplimiento de promesas por parte del Banco que fue materia de estudio.The present study has been carried out with the purpose of determining how the quality of the service influences customer satisfaction in the Azteca bank in the El Porvenir district. The effect cause design was used, using the survey technique and the questionnaire as an instrument, the sample was obtained from Banco Azteca clients in the El Porvenir district. The results of the investigation have allowed us to know the influence of the satisfaction of the clients regarding the perceived quality in the Banco Azteca in the El Porvenir District. In this way it has been possible to know the significant relationship that exists between the quality of the service and the satisfaction of the clients; likewise, the influence that it generates on the clients of Banco Azteca in the El Porvenir district; and it is concluded that the quality of service has a direct influence on customer satisfaction, in addition to the fact that in most cases customers are satisfied with the services provided, the physical facilities, the material elements and the fulfillment of promises by part of the Bank that was the subject of study.Tesi