937 resultados para weak instruments
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Understanding of the Atmospheric Boundary Layer (ABL) is imperative in the arena of the monsoon field. Here, the features of the ABL are studied employing Conserved Variable Analysis (CVA) using equivalent potential temperature and humidity. In addition, virtual potential temperature and wind are used during active and weak phases of monsoon. The analysis is carried out utilising the radiosonde observations during the monsoon months for two stations situated in the west coast of India. All these parameters show considerable variations during active and weak monsoon phases in both the stations. The core speed and core height vary with these epochs. The core speed is found to be more than 38 knots in the active monsoon phase around 1.2 km over Trivandrum and around 2 km over Mangalore. But during weak monsoon phase the core wind speed is decreased and core height is elevated over both stations. The wind direction shows an additional along shore component during weak monsoon period. The Convective Boundary Layer (CBL) height shows increase during weak monsoon phase over both stations due to less cloudiness and subsequent insolation. The CBL height during the southwest monsoon is more over Mangalore and is attributed by the orographic lifting in the windward side of the Western Ghats while the influence of the Ghats is less over Trivandrum.
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Larvae of Macrobrachium rosenbergii (De Man) are photopositive (Ling 1969a.b) and negatively rheotactic. While investigating larval diseases of M, rosenbergii it was observed that weak larvae failed to show both these responses. It was felt that this lack of response could be used to develop a device for separating the weak larvae from the apparently healthy ones. Such a device would be a valuable tool for assessing the health of a batch in terms of the percentage of 'healthy' and 'weak' larvae. What follows is a description and mode of operation of the 'photo-flow' device developed by the authors
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The motion of a viscous incompressible fluid flow in bounded domains with a smooth boundary can be described by the nonlinear Navier-Stokes equations. This description corresponds to the so-called Eulerian approach. We develop a new approximation method for the Navier-Stokes equations in both the stationary and the non-stationary case by a suitable coupling of the Eulerian and the Lagrangian representation of the flow, where the latter is defined by the trajectories of the particles of the fluid. The method leads to a sequence of uniquely determined approximate solutions with a high degree of regularity containing a convergent subsequence with limit function v such that v is a weak solution of the Navier-Stokes equations.
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In this paper we investigate the optimal choice of prices and/or exams by universities in the presence of credit constraints. We first compare the optimal behavior of a public, welfare maximizing, monopoly and a private, profit maximizing, monopoly. Then we model competition between a public and a private institution and investigate the new role of exams/prices in this environment. We find that, under certain circumstances, the public university may have an interest to raise tuition fees from minimum levels if it cares for global welfare. This will be the case provided that (i) the private institution has higher quality and uses only prices to select applicants, or (ii) the private institution has lower quality and uses also exams to select students. When this is the case, there are efficiency grounds for raising public prices
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The paper discusses maintenance challenges of organisations with a huge number of devices and proposes the use of probabilistic models to assist monitoring and maintenance planning. The proposal assumes connectivity of instruments to report relevant features for monitoring. Also, the existence of enough historical registers with diagnosed breakdowns is required to make probabilistic models reliable and useful for predictive maintenance strategies based on them. Regular Markov models based on estimated failure and repair rates are proposed to calculate the availability of the instruments and Dynamic Bayesian Networks are proposed to model cause-effect relationships to trigger predictive maintenance services based on the influence between observed features and previously documented diagnostics
Evaluation of strategic knowledge of students through authentic tasks of writingin science classroom
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The difficulties at evaluating strategic knowledge have been connected to the use of deconxetualized tests that, at the end, do not involve the use of this knowledge. For this reason, an interest in developing authentic writing tasks that offer advantages for these kinds of evaluation have arisen. Throughout this research, authentic writing tasks were developed in a natural sciences class, with the purpose of evaluating the students' strategic knowledge. Different instruments were used to collect data, e.g. Interviews, questionnaires, a self-inform, as well as three samples of writing by the students, with the objective of analyzing the changes that occurred between one and the others, as well as to determine the decisions that students made in order to complete the assigned tasks successfully. An authentic writing task gives great opportunities to evaluate strategic knowledge. These tasks lead students to arrange their knowledge about the topic in hand, organize and adapt it to fit the objectives and the audience, also, it allows them to control and adjust their decisions on the task. This last stage became the perfect opportunity to take notes on the knowledge and regulation of cognitive processes that the students brought into play, as well as to evaluating their understanding of writing and the demands given on the different discursive genres. As a result, the students showed different degrees of strategic knowledge in the task. The students who showed a better strategic knowledge trust in their structural abilities know about discursive genres and have a good performance in basic linguistic abilities. The students who showed weak strategic knowledge distrust their writing skills, seem extremely worried about organizing the content of their texts, fail when checking their writings, and overlook or are unaware of the basic requirements of the discursive genre they are asked to exemplify. It appears that the previous knowledge and experiences at writing the students have been exposed to may affect the strategic knowledge shown when writing in this subject.
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La escoliosis es una desviación lateral de la columna vertebral desde la línea media, caracterizada por una curvatura lateral y por una rotación vertebral. Generalmente, es de carácter idiopático y se presenta, principalmente, en niñas adolescentes. Existen múltiples técnicas de tratamiento conservador para la escoliosis, entre las cuales se encuentran la terapia manual, que complementa el tratamiento para dicha patología. Esta terapia utiliza menos medios físicos, más manipulación de tejidos blandos y óseos, y logra así una recuperación más eficaz, con una mejor calidad de vida. El objetivo de este estudio de caso es comparar y describir los cambios en las condiciones de una paciente de 18 años, con escoliosis idiopática juvenil en columna toracolumbar izquierda, al aplicar un tratamiento de terapia manual. Se realizaron procedimientos de valoración integral mediante terapia manual, ortopedia, postura computarizada, análisis del puesto de trabajo, tratamiento con medios físicos y movilización de las articulaciones torácicas y lumbares, en los segmentos vertebrales que presentaban disminución del deslizamiento inferior de las carillas inferiores de la vértebra superior, sobre las carillas superiores de la vértebra inferior (segmentos T5-T6, T6-T7, T7-T8, T8-T9);técnicas de energía muscular, ejercicios de reeducación postural global, estabilización cervical y lumbar, ejercicios de fortalecimiento para musculatura débil del hemicuerpo izquierdo y de estiramiento, con el fin de elongar la musculatura retraída del hemicuerpo derecho. Al iniciar el tratamiento, se verificó, mediante una radiografía, que el ángulo de Cobb era de 24º; después de las sesiones de terapia manual se logró reducir a 18º, lo que generó una disminución significativa de 6º. Se verificó la efectividad del tratamiento por la disminución del dolor, el aumento de la fuerza muscular, la realineación postural, la satisfacción del paciente y la recuperación significativa comprobada por los estudios radiológicos.
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La presión que ejerce el manguito del tubo orotraqueal (TOT) sobre la mucosa al ser insuflado debe mantenerse en un rango de seguridad que evite complicaciones por sobreinflación o por desinsuflación. En nuestro medio, los instrumentos de medición objetiva no son de uso común. Objetivo: evaluar la concordancia de la presión del manguito del TOT estimada por palpación frente al uso de un manómetro manual en pacientes adultos sometidos a anestesia general. Materiales y métodos: se realizó un estudio de corte transversal que incluyó a 40 pacientes, a quienes, una vez intubados, dos anestesiólogos enmascarados, diferentes al que los intubó, palparon el manguito del TOT categorizándolo como sobreinflado, normal o desinflado; posteriormente, uno de los investigadores registró la medida con un manómetro en fase inspiratoria y espiratoria. Se consideró como rango normal de 20 a 30 cm H2O. Resultados: la concordancia de la estimación por palpación entre los dos anestesiólogos fue débil (Kappa = 0,21, ES: 0,11). La concordancia entre la estimación por palpación y la medición con el manómetro manual fue muy débil. Entre el primer anestesiólogo y el investigador en fase inspiratoria, . 0,08 (ES: 0,09), y en espiración, . 0,08 (ES: 0,07). Entre el segundo anestesiólogo y el investigador, . 0,05 (ES: 0,07) y 0,02 (ES: 0,06), respectivamente. Conclusión: el estudio muestra que la concordancia entre los métodos subjetivo y objetivo para determinar si el manguito del TOT está adecuadamente inflado fue débil. Se sugiere el empleo de métodos más objetivos para su determinación.
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Free media may not favor political accountability when other democratic institutions are weak, and may even bring undesirable unintended consequences. We propose a simple model in which politicians running for office may engage in coercion to obtain votes. A media scandal that exposes these candidates increases their coercion effort to offset the negative popularity shock. This may result in the tainted politicians actually increasing their vote share. We provide empirical evidence from one recent episode in the political history of Colombia, the ‘parapolitics’ scandal featuring politicians colluding with illegal armed paramilitary groups to obtain votes. We show that colluding candidates not only get more votes than their clean competitors, but also concentrate them in areas where coercion is more likely (namely, areas with more paramilitary presence, less state presence, and more judicial inefficiency). Harder to reconcile with other explanations and as a direct test of the effects of media exposure, we compare tainted candidates exposed before elections to those exposed after. We find that those exposed before elections get as many votes as those exposed once elected, but their electoral support is more strongly concentrated in places where coercion is more likely. Our re