3,046 research outputs found
Double corrugated waveguide for Ka-Band traveling wave tube
The double corrugated waveguide (DCW), incorpo- rating a row of metallic pillars on each side of the electron beam, is demonstrated as a promising slow-wave structure for millimeter wave, Ka-band, traveling wave tubes (TWTs). Different configurations, including novel bent couplers with tapered pillars, have been designed, realized, and validated by S-parameter measurements. The design and simulation of a DCW TWT demonstrated very good performance in the frequency band 32–37 GHz. The ease of fabrication and assembly make the DCW a suitable basis for a new generation of millimeter wave TWTs
Actrices de l'ombre: la réappropriation identitaire des femmes latino-américaines sans-papiers
Real-time Emergency Response through Performant IoT Architectures
International audienceThis paper describes the design of an Internet of Things (IoT) system for building evacuation. There are two main design decisions for such systems: i) specifying the platform on which the IoT intelligent components should be located; and ii) establishing the level of collaboration among the components. For safety-critical systems, such as evacuation, real-time performance and evacuation time are critical. The approach aims to minimize computational and evacuation delays and uses Queuing Network (QN) models. The approach was tested, by computer simulation, on a real exhibition venue in Alan Turing Building, Italy, that has 34 sets of IoT sensors and actuators. Experiments were performed that tested the effect of segmenting the physical space into different sized virtual cubes. Experiments were also conducted concerning the distribution of the software architecture. The results show that using centralized architectural pattern with a segmentation of the space into large cubes is the only practical solution
An Application of Item Response Theory to Psychological Test Development
Item response theory (IRT) has become a popular methodological framework for modeling response data from assessments in education and health; however, its use is not widespread among psychologists. This paper aims to provide a didactic application of IRT and to highlight some of these advantages for psychological test development. IRT was applied to two scales (a positive and a negative affect scale) of a self-report test. Respondents were 853 university students (57 % women) between the ages of 17 and 35 and who answered the scales. IRT analyses revealed that the positive affect scale has items with moderate discrimination and are measuring respondents below the average score more effectively. The negative affect scale also presented items with moderate discrimination and are evaluating respondents across the trait continuum; however, with much less precision. Some features of IRT are used to show how such results can improve the measurement of the scales. The authors illustrate and emphasize how knowledge of the features of IRT may allow test makers to refine and increase the validity and reliability of other psychological measures
Aplicación del ciclo de Deming para aumentar la productividad del área de chancado en una minera que extrae oro, Perú - 2016
Esta tesis fue realizada con el fin de analizar la ―Aplicación del ciclo de Deming para aumentar la productividad del área de chancado en minera que extrae oro, Perú - 2016‖ y cuyo objetivo general es Determinar cómo el Ciclo de Deming aumentará la productividad del área de chancado. Para lo cual usaremos el concepto de José Moyano quien fundamenta la filosofía del Ciclo de Deming (PHVA) que busca la mejora continua de los procesos y como interactúa con la Productividad del área de Chancado afectando su Eficiencia y Eficacia, términos definidos por García Cantú en sus escritos.
El trabajo que se presenta es de diseño pre experimental pues manipulamos deliberadamente una variable para estudiar los efectos sucedidos en otra variable por medio de fichas de observación validados mediante el juicio de expertos y recabando datos en planta concentradora, el muestreo es nulo pues la población es en cantidad 12 datos, tonelajes de los 12 meses del año 2016, tomados de dos (02) Chancadoras cónicas MP- 800
Síndrome de Takotsubo: complicación cardiovascular del accidente cerebrovascular
An 82-year-old woman, Katz A, with a history of type 2 diabetes mellitus and high blood pressure, was admitted for ischemic stroke complicated by Takotsubo ́s syndrome with subsequent readmission for atrial fibrillation after discharge. These three clinical events have criteria to be integrated as a Brain Heart Syndrome, which is a high-risk condition for mortality.Mujer adulta mayor, 82 años, Katz A, con antecedente de diabetes mellitus tipo 2 e hipertensión arterial; ingresa por accidente cerebrovascular isquémico que se complica con síndrome de Takotsubo con posterior reingreso por fibrilación auricular tras el alta médica. Estos tres eventos clínicos tienen criterios para integrarse como un síndrome cerebro-corazón, el cual es una condición de alto riesgo para mortalidad
Cooperative WebLab in chemical engineering between France and Brazil: Validation of the methodology
A WebLab is an experiment operated remotely via Internet. Besides the strictly technical aspects of such an experiment, which may contribute to the learning of Chemical Engineering fundamentals, there is also important feedback when teams of students of two different countries are working together: the WebLab becomes an intercultural experience, enhancing the communication skills of the students. A WebLab between Universidade Federal de São Carlos (DEQ/UFSCar) and the Ecole Nationale Supérieure d’Ingénieurs en Arts Chimiques et Technologiques (ENSIACET) is presented in this work. A mass transfer experiment in a bench scale reactor (stirred and aerated) had to be studied by mixed teams, thus emulating challenges that will be common in future working environments. In order to perform the experiment, students in Brazil and in France were put into groups. The students had to make decisions about the procedure for executing the experiments. All the students were able to control the equipment, no matter where they were physically. Students communicated using video conference software. The students' and teachers' opinions of this experience were very positive. This methodology is an important contribution to the education of engineers in a world integrated by modern communication technologies
Participatory Budgeting in the Municipality of Santo André, Brazil: The challenges in linking short-term action and long-term strategic planning
This report is addressed to professionals and urban practitioners who are interested in
participatory planning processes and in the establishment of organised priority setting
mechanisms and decision-making involving government and communities on the allocation
of public investments. Those who work in the public sector or with public policies at the
local government level will benefit from the findings of the research particularly if their
interest lies on the establishment of government-community management of public funds.
The findings of the research will be instrumental for NGO’s and CBO’s that are engaged in
partnerships with local governments.
The primary objective of the research is to analyse and describe the experience of the
municipality of Santo André with participatory budgeting hereinafter called OP ( Orçamento
Participativo) depicted from interviews and observations of key actors and stakeholders
directly involved in the OP, and from the analysis of internal documents of the municipality.
The research also makes a first attempt to unveil issues underlying the integration of the
participatory budgeting (OP) as a short-term planning activity and the recently started
strategic planning process hereinafter called CF (Cidade Futuro) as a long-term
development planning process. The research makes use of participants’ observations and
qualitative methods and intends not only to analyse and describe in detail the OP and CF in
Santo André but also questions to what extent this peculiar participatory process can be
replicated in other municipalities seeking direct citizen involvement in municipal affairs.
The authors attempt to look at the lessons learned from these experiences in order to depict
issues, processes and methodologies that can be replicated in Bolivian municipalities and
particularly in Santa Cruz de la Sierra. The authors look at this possibility against the
enactment of legislation (Law of Popular Participation, Law on Municipalities, Sustainable
Municipal Development Plan-SMDP) that seems to have created a conducive environment
for genuine civil participation in urban management in Bolivian local governments. The
Spanish report pays a particular attention to this dimension
Electrodynamic tether at Jupiter 2. Tour missions after capture
Three separate scenarios of an electrodynamic tether mission at Jupiter following capture of a spacecraft (SC) into an equatorial, highly elliptical orbit around the planet, with perijove at about 1.5 times the Jovian radius,
are discussed. Repeated application of Lorentz drag on the spinning tether, at the perijove vicinity, can progressively lower the apojove. One mission involves the tethered-SC rapidly and frequently visiting Galilean moons;
elliptical orbits with apojove down at the Ganymede, Europa, and Io orbits are in 2:5, 4:9, and 1:2 resonances with the respective moons. About 20 slow flybys of Io would take place before the accumulated radiation dose exceeds 3 Mrad (Si) at 10 mm Al shield thickness, with a total duration of 5 months after capture (4 months for lowering the apojove to Io and one month for the flybys). The respective number of flybys for Ganymede would be 10 with a total duration of about 9 months. An alternative mission would have the SC acquire a low circular orbit around Jupiter, below the radiation belts, and manoeuvre to get an optimal altitude, with no major radiation effects, in less than 5 months after capture. In a third mission, repeated thrusting at the apojove vicinity, once down at the Io
torus, would raise the perijove itself to the torus to acquire a low circular orbit around Io in about 4 months, for a total of 8 months after capture; this corresponds, however, to over 100 apojove passes with an accumulated
dose, of about 8.5 Mrad (Si), that poses a critical issue
Electrodynamic tether at Jupiter II:Fast moon tour after capture
An electrodynamic bare-tether mission to Jupiter,following the capture of a spacecraft (SC) into an equatorial
highly elliptical orbit with perijove at about 1.3 times the Jovian radius, is discussed. Repeated applications of the propellantless Lorentz drag on a spinning tether, at the perijove vicinity, can progressively lower the apojove at constant perijove, for a tour of Galilean moons. Electrical energy is generated and stored as the SC moves from an orbit at 1 : 1 resonance with a moon, down
to resonance with the next moon; switching tether current off, stored power is then used as the SC makes a number of flybys of each moon. Radiation dose is calculated throughout the mission,during capture, flybys and moves between moons. The tour mission is limited by both power needs and accumulated dose. The three-stage apojove lowering down to Ganymede, Io, and Europa resonances would total less than 14 weeks, while 4 Ganymede, 20 Europa, and 16 Io flybys would add up to 18 weeks, with the entire mission taking just over seven months and the accumulated
radiation dose keeping under 3 Mrad (Si) at 10-mm Al shield
thickness
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