992 resultados para mobile-immobile advection-dispersion equation


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This paper proposes the use of an autonomous assistant mobile robot in order to monitor the environmental conditions of a large indoor area and develop an ambient intelligence application. The mobile robot uses single high performance embedded sensors in order to collect and geo-reference environmental information such as ambient temperature, air velocity and orientation and gas concentration. The data collected with the assistant mobile robot is analyzed in order to detect unusual measurements or discrepancies and develop focused corrective ambient actions. This paper shows an example of the measurements performed in a research facility which have enabled the detection and location of an uncomfortable temperature profile inside an office of the research facility. The ambient intelligent application has been developed by performing some localized ambient measurements that have been analyzed in order to propose some ambient actuations to correct the uncomfortable temperature profile.

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A thorough critical analysis of the theoretical relationships between the bond-angle dispersion in a-Si, Δθ, and the width of the transverse optical Raman peak, Γ, is presented. It is shown that the discrepancies between them are drastically reduced when unified definitions for Δθ and Γ are used. This reduced dispersion in the predicted values of Δθ together with the broad agreement with the scarce direct determinations of Δθ is then used to analyze the strain energy in partially relaxed pure a-Si. It is concluded that defect annihilation does not contribute appreciably to the reduction of the a-Si energy during structural relaxation. In contrast, it can account for half of the crystallization energy, which can be as low as 7 kJ/mol in defect-free a-Si

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We deal with a system of prisoner’s dilemma players undergoing continuous motion in a two-dimensional plane. In contrast to previous work, we introduce altruistic punishment after the game. We find punishing only a few of the cooperator-defector interactions is enough to lead the system to a cooperative state in environments where otherwise defection would take over the population. This happens even with soft nonsocial punishment (where both cooperators and defectors punish other players, a behavior observed in many human populations). For high enough mobilities or temptations to defect, low rates of social punishment can no longer avoid the breakdown of cooperation

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Problems in the mobile services are complex where the lack of the user analysis is not the modest issue. User centered design has increasingly become as a basis for the design of mobile services. The concept of user centered design gives end-user extensive attention at each stage of the design process. Mobile service providers want to offer experiences for users and clearly the users look for services that can provide pleasant experiences. In this thesis, the elements of user experience in mobile internet were studied as well as user experience measuring methods were researched. This study was looking for user experience measuring metrics and methods to specify new factors to measure user experience. During this thesis research project an application called CEM4Mobile was designed and implemented. CEM4Mobile is an application for observing and analysing user experience based on the user activity and behaviour. As a result of this thesis, a collection of user experience elements and measuring metrics were found. The elements and metrics were designed and implemented to CEM4Mobile product, which measures user experience. It was found out that the user experience measuring methods were based on interaction between two people but CEM4Mobile makes user observation programmatic.

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The problematic use of mobile phones among adolescents has not been widely studied. There are very few instruments for assessing potential technological addiction to mobile phones, or for categorizing different types of users or uses. The most widely used scale is the Mobile Phone Problem Use Scale (MPPUS), which is used to study adult populations, and has been applied in various forms in international contexts. The aims of this study were to adapt the Spanish version of this scale (MPPUSA) to British adolescents, and then to estimate the prevalence of possible problematic users. A questionnaire was administered to a sample of 1,529 secondary school pupils aged between 11 and 18 years, with 1,026 completed questionnaires being collected. The analysis showed that the factor and construct validity and reliability were comparable to those obtained in previous studies. The prevalence of problematic users among the students was 10%, and the typical problematic user tended to be an adolescent between 11 and 14 years old, studying in a public school, who considered themselves to be an expert user of this technology, who made extensive use of his/her mobile phone, and who attributed the same problem of use among their peers. These users presented notable scores in all the symptoms covered by the scale used to assess problematic use. In conclusion, the adaptation of the MPPUSA as a screening scale for British adolescents presents good sensitivity and specificity for detecting the main addictive symptoms proposed in this validated version.

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El uso problemático del teléfono móvil es un fenómeno emergente en nuestra sociedad, que parece afectar especialmente a la población adolescente. El conocimiento acerca del uso problemático de esta tecnología resulta necesario, dado que puede desarrollarse un patrón comportamental con características adictivas. Apenas existen escalas que midan el posible uso problemático del móvil y ninguna adaptada exclusivamente a población adolescente española. La escala más utilizada internacionalmente es la Mobile Phone Problematic Use Scale (MPPUS). El objetivo de este estudio es adaptar el MPPUS a la población adolescente española. Se administró la versión española del cuestionario a una muestra de 1132 de 12 a 18 años. La fiabilidad y la validez factorial eran comparables a las obtenidas en población adulta, por lo que la medida del uso problemático del móvil en los adolescentes españoles es unidimensional. Se detectó una prevalencia del 14.8% de usuarios problemáticos.

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La comunicació mòbil és un dels temes de més actualitat en diferents fòrums, des de diferents perspectives. Espanya juga un paper important per les dinàmiques i l’evolució del seu mercat. En aquest sentit, el nostre país ofereix un interès específic per l'amplitud del seu parc de dispositius 3G (el segon d'Europa, després d'Itàlia) i per la intensitat del desenvolupament de xarxes socials mòbils, a més de per la creixent implicació d'empreses en la producció i distribució de continguts mòbils. Com va passar amb Internet, es tracta d’un procés d'innovació pel qual els formats de contingut, les pràctiques de consum i els models de negoci característics de la televisió i la xarxa, per exemple, s'adapten, primer, al nou mitjà, per a després desenvolupar formes i models específics que aprofiten les potencialitats de personalització, geolocalització i conectivitat ubiqua.

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Mobile technology plays an increasing role in interpersonal communication,representing a useful resource for different age cohorts. While the usage ofmobile communication by younger people has received a wide attention fromcommunication scholars, its usage by older people is less explored. Thegoal of our research project is to analyse the usage of mobile phones by theelderly in Italy. We conducted 51 semi-structured interviews in Rome and in amid-range town located in Umbria, between October 2013 and February 2014.Our study explores older users¿ motivations and usage practices, their perceptions of mobile phones, theiradoption and domestication of mobile phones, their usage skills. More specifically,our analysis focuses on: - personal characteristics - personal networks (personalnetwork composition, self-perceived social life, communication channels) -adoption of mobile telephone - consumption patterns of mobile devices - usedmobile services - location and mobility of mobile telephone - current mobilecharacteristics - attitude and opinions towards mobile technology Our preliminaryresults show major differences in users¿ behaviours and perceptions, that canbe related to age cohorts (younger olds vs older olds); socio-cultural levels;vital trajectories (in terms of professional and familiar status); and gender.

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The assembly of a photochemical reactor with six fluorescent lamps, used for photopolymerizations is described. This chamber presents a mobile support, allowing the placement of samples at different heights and a safety lock that interrupts the radiation, if it is opened during operation. The mirrored internal walls avoid the dispersion and non-uniform distribution of light. There is no high heating because the own character of the used lamps. All parts could be purchased in commerce with less than U$ 150,00. This reactor was successfully used for monolithic stationary phase photopolymerization.

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Saponins are natural soaplike foam-forming compounds widely used in foods, cosmetic and pharmaceutical preparations. In this work foamability and foam lifetime of foams obtained from Ilex paraguariensis unripe fruits were analyzed. Polysorbate 80 and sodium dodecyl sulfate were used as reference surfactants. Aiming a better data understanding a linearized 4-parameters Weibull function was proposed. The mate hydroethanolic extract (ME) and a mate saponin enriched fraction (MSF) afforded foamability and foam lifetime comparable to the synthetic surfactants. The linearization of the Weibull equation allowed the statistical comparison of foam decay curves, improving former mathematical approaches.

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An evaluation of the pesticides extracted from the soil matrix was conducted using a citrate-buffered solid phase dispersion sample preparation method (QuEChERS). The identification and quantitation of pesticide compounds was performed using gas chromatography-mass spectrometry. Because of the occurrence of the matrix effect in 87% of the analyzed pesticides, the quantification was performed using matrix-matched calibration. The method's quantification limits were between 0.01 and 0.5 mg kg-1. Repeatability and intermediate precision, expressed as a relative standard deviation percentage, were less than 20%. The recoveries in general ranged between 62% and 99%, with a relative standard deviation < 20%. All the responses were linear, with a correlation coefficient (r) ≥0.99.

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This work is devoted to investigation of wave processes in new hybrid ferrite/ferroelectric structures. Spin wave devices based on ferrite films have disadvanteges. And their applications are limited. Investigated structures allow to overcome disadvantages. This investigation helps to create new class of devices. Electromagnetic analysis of hybrid spin-electromagnetic waves in ferrite/ferroelectric structures were done. As a result dispersion relation was found. Numerical solution of this dispersion relation gave us follow results. These structures can be effectively tuned by external electric and magnetic field. Methods to increase tuning range were suggested. It was found that such structures have one basic disadvantage which is connected with presence of thick ferroelectric layer. To solve this problem is to use thin ferroelectric films. But this decreases tuning range. It was confirmed by experiment that this structures can be effectively tuned by electric and magnetic fields. Resonance characteristics of ferrite/ferroelectric resonator were succesfully tuned by magnetic and electric field.

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The subject being analyzed of this Master’s Thesis is a development of a service that is used to define a current location of a mobile device. The service utilized data that is obtained from own GPS receiver in some possible cases and as well data from mobile devices which can be afforded for the current environment for acquisition of more precise position of the device. The computation environment is based on context of a mobile device. The service is implemented as an application for communicator series Nokia N8XX. The Master’s Thesis presents theoretical concept of the method and its practical implementation, architecture of the application, requirements and describes a process of its functionality. Also users’ work with application is presented and recommendations for possible future improvements are made.