92 research outputs found

    Every Cloud Has a Push Data Lining: Incorporating Cloud Services in a Context-Aware Application

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    We investigated context-awareness by utilising multiple sources of context in a mobile device setting. In our experiment we developed a system consisting of a mobile client, running on the Android platform, integrated with a cloud-based service. These components were integrated using pushmessaging technology.One of the key featureswas the automatic adaptation of smartphones in accordance with implicit user needs. The novelty of our approach consists in the use of multiple sources of context input to the system, which included the use of calendar data and web based user configuration tool, as well as that of an external, cloud-based, configuration file storing user interface preferences which, pushed at log-on time irrespective of access device, frees the user from having to manually configure its interface.The systemwas evaluated via two rounds of user evaluations (n = 50 users), the feedback of which was generally positive and demonstrated the viability of using cloud-based services to provide an enhanced context-aware user experience

    Towards cloud to device push messaging on android: Technologies, possibilities and challenges

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    In this paper we look at different push messaging alternatives available for Android. Push messaging provides an im-portant aspect of server to device communication, and we specifically focus on the integration of cloud computing with mo-bile devices through the use of push-based technologies. By conducting a benchmarking test, we investigate the performance of four relevant push technologies for the Android platform, namely C2DM, XMPP, Xtify and Urban Airship. The compari-son focuses on three aspects of the libraries: 1) The stability; 2) Response times; and 3) Energy consumption. The test is con-ducted on both WLAN and 3G, and includes several mobile device types. Additionally, we also integrate with the Google App Engine to provide the cloud integration server that is responsible for sending push messages to the mobile devices

    A round-robin study of cellulose pyrolysis kinetics by thermogravimetry

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    Eight European laboratories with access to five different thermogravimetric analyzers participated in this round-robin study of Avicel PH-105 cellulose pyrolysis at 5 and 40 °C/min. Agreement between the laboratories on the temperature (Tpeak) associated with the maximum rate of weight loss at 5 °C/min was good. Less agreement was obtained on the residual char yield. At 40 °C/min, the scatter associated with measurements of Tpeak and the char yield increased. Good fits to each weight loss curve were obtained by use of a kinetic model based on an irreversible, first order reaction with a high (ca. 244 kJ/mol) apparent activation energy (E). Variations in values of E and the pre-exponential constant (A) are attributed to variations in thermal lag between the various instruments, and at different heating rates. Kinetic parameters are presented which offer a good fit to the 5 °C/min round-robin data, and which prescribe an envelope that contains the data. We recommend that future studies of biomass pyrolysis by thermogravimetry include an analysis of Avicel PH 105 cellulose at 5 °C/min, and a comparison of the resulting weight loss curve with the curves presented herein

    Context-aware and automatic configuration of mobile devices in cloud-enabled ubiquitous computing

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s00779-013-0698-3. Copyright @ Springer-Verlag London 2013.Context-sensitive (or aware) applications have, in recent years, moved from the realm of possibilities to that of ubiquity. One exciting research area that is still very much in the realm of possibilities is that of cloud computing, and in this paper, we present our work, which explores the overlap of these two research areas. Accordingly, this paper explores the notion of cross-source integration of cloud-based, context-aware information in ubiquitous computing through a developed prototypical solution. Moreover, the described solution incorporates remote and automatic configuration of Android smartphones and advances the research area of context-aware information by harvesting information from several sources to build a rich foundation on which algorithms for context-aware computation can be based. Evaluation results show the viability of integrating and tailoring contextual information to provide users with timely, relevant and adapted application behaviour and content

    Combustion Characteristics of Biomass Charcoals Produced at Different Carbonization Conditions: A Kinetic Study

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    The combustion properties of spruce chars and spruce forest residue chars were studied in the kinetic regime by a series of thermogravimetric analysis (TGA) experiments. The work aimed at establishing how the pressure of the char preparation affects the reactivity with oxygen. Parts of the chars were prepared from a thin layer of biomass in inert gas flow at atmospheric pressure and 0.8 MPa. Other chars were formed in a pressurized reactor by a flash carbonization method [Antal, M. J., Jr.; Mochidzuki, K.; Paredes, L. S. Flash carbonization of biomass. Ind. Eng. Chem. Res. 2003, 42 (16), 3690-3699, DOI: 10.1021/ie0301839]. Despite the differences in the preparation, remarkable similarities were observed in the combustion behavior of the samples. The kinetics of the char burnoff was described by assuming three partial reactions. A total of 18 experiments at three different temperature programs were evaluated by the method of least squares to obtain dependable kinetic model variants. A common activation energy of 150 kJ/mol gave a reasonable description for the three partial reactions in all experiments

    Thermogravimetric and reaction kinetic analysis of biomass samples from an energy plantation

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    The products of a Hungarian experimental plantation for energy crops were investigated. Young shoots of poplar clones (Populus x euramericana and Populus x interamericana), black locust (Robinia pseudoacacia), willow (Salix alba), and an herbaceous plant (Miscanthus sinensis) revealed unexpectedly similar thermal behavior in inert and oxidative atmospheres, as well. An 8-fold difference in the level of grinding did not result in substantial differences in the thermal decomposition. The effect of oxygen in the ambient gas was studied at low sample masses (0.2-0.4 mg) that excluded the overheating due to the high reaction heat of the combustion process. The presence of oxygen affects the decomposition from ca. 220 degreesC. Nevertheless, the extrapolated onset temperature of the hemicellulose decomposition is practically the same at 0, 5, and 21 V/V% oxygen. A group of 12 experiments, representing two grinding levels, three plant genera and four different heating programs were evaluated simultaneously by the method of least squares employing the model of independent pseudocomponents. All evaluated experiments were well described by the same set of kinetic parameters; only the parameters describing the peak area of the partial processes differed. A technique was recommended for the appropriate handling of the nonrandom errors in the simultaneous evaluation of experiment series

    PainDroid: An android-based virtual reality application for pain assessment

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    Earlier studies in the field of pain research suggest that little efficient intervention currently exists in response to the exponential increase in the prevalence of pain. In this paper, we present an Android application (PainDroid) with multimodal functionality that could be enhanced with Virtual Reality (VR) technology, which has been designed for the purpose of improving the assessment of this notoriously difficult medical concern. Pain- Droid has been evaluated for its usability and acceptability with a pilot group of potential users and clinicians, with initial results suggesting that it can be an effective and usable tool for improving the assessment of pain. Participant experiences indicated that the application was easy to use and the potential of the application was similarly appreciated by the clinicians involved in the evaluation. Our findings may be of considerable interest to healthcare providers, policy makers, and other parties that might be actively involved in the area of pain and VR research

    Mathematical modeling of sleep state dynamics in a rodent model of shift work

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    Millions of people worldwide are required to work when their physiology is tuned for sleep. By forcing wakefulness out of the body’s normal schedule, shift workers face numerous adverse health consequences, including gastrointestinal problems, sleep problems, and higher rates of some diseases, including cancers. Recent studies have developed protocols to simulate shift work in rodents with the intention of assessing the effects of night-shift work on subsequent sleep (Grønli et al., 2017). These studies have already provided important contributions to the understanding of the metabolic consequences of shift work (Arble et al., 2015; Marti et al., 2016; Opperhuizen et al., 2015) and sleep-wake-specific impacts of night-shift work (Grønli et al., 2017). However, our understanding of the causal mechanisms underlying night-shift-related sleep disturbances is limited. In order to advance toward a mechanistic understanding of sleep disruption in shift work, we model these data with two different approaches. First we apply a simple homeostatic model to quantify differences in the rates at which sleep need, as measured by slow wave activity during slow wave sleep (SWS) rises and falls. Second, we develop a simple and novel mathematical model of rodent sleep and use it to investigate the timing of sleep in a simulated shift work protocol (Grønli et al., 2017). This mathematical framework includes the circadian and homeostatic processes of the two-process model, but additionally incorporates a stochastic process to model the polyphasic nature of rodent sleep. By changing only the time at which the rodents are forced to be awake, the model reproduces some key experimental results from the previous study, including correct proportions of time spent in each stage of sleep as a function of circadian time and the differences in total wake time and SWS bout durations in the rodents representing night-shift workers and those representing day-shift workers. Importantly, the model allows for deeper insight into circadian and homeostatic influences on sleep timing, as it demonstrates that the differences in SWS bout duration between rodents in the two shifts is largely a circadian effect. Our study shows the importance of mathematical modeling in uncovering mechanisms behind shift work sleep disturbances and it begins to lay a foundation for future mathematical modeling of sleep in rodents

    REST4Mobile: A framework for enhanced usability of REST services on smartphones

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    Considering end-user research and proliferation of smartphones and REpresentational State Transfer (REST) interfaces, we envisage that smartphone owners can innovate to compose applications on the small screen. This paper presents the design and evaluation of a REST service development framework (viz, REST4Mobile) with the aim to enhance the usability when consuming on smartphones. Our design process uses the usability factors identified in our previous work as primary constraints for modeling the framework and a corresponding composition tool. Thus, sample REST services are developed with and then without the framework, and usability of composing the services on smartphones is evaluated. Evaluation was conducted by deploying the component REST services, the composition tool, and the resulting composite apps on a local machine. As the task of service composition is conducted directly on the smartphone's screen, the evaluation process is designed to be repeatable on remote servers and on the cloud. Results showed that constraints can be added into the REST architectural style on the basis of the influences of domain specific terms and human cognitive capabilities on the naming and size of the Uniform Resource Identifiers (URIs). In addition, the principles embodying the framework are found to be influential factors in enhancing the usability of REST services on smartphones
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