194 research outputs found

    Machine learning stochastic design models.

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    Due to the fluid nature of the early stages of the design process, it is difficult to obtain deterministic product design evaluations. This is primarily due to the flexibility of the design at this stage, namely that there can be multiple interpretations of a single design concept. However, it is important for designers to understand how these design concepts are likely to fulfil the original specification, thus enabling the designer to select or bias towards solutions with favourable outcomes. One approach is to create a stochastic model of the design domain. This paper tackles the issues of using a product database to induce a Bayesian model that represents the relationships between the design parameters and characteristics. A greedy learning algorithm is presented and illustrated using a simple case study

    Development of a simple information pump.

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    The Information Pump (IP) is a methodology that aims to counter the problems arising from traditional subjective product data collection. The IP is a game theory based process that aims to maximise information extracted from a panel of subjects, while maintaining their interest in the process through a continuous panelist scoring method. The challenge with implementing this arises from the difficulty in executing the 'game'. In its original format, there is an assumption that the game is played with each player using their own PC to interact with the process. While this in theory allows information and scores to flow in a controlled manner between the players, it actually provides a major barrier to the wider adoption of the IP method. This barrier is two-fold: it is costly and complex, and it is not a natural manner for exchanging information. The core objective is to develop a low cost version of the IP method. This will use the game theory approach to maintain interest among participants and maximise information extraction, but remove the need for each participant to have their own PC interface to the game. This will require replacing both the inter-player communication method and the score keeping/reporting

    Physicochemical properties and fatty acid composition of star fruit (Averrohoa carambola) seed oil

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    To meet the increasing demands for oil, improvements are being made to produce unique and desirable oils, therefore increasing interest in newer sources of edible oils from natural sources. The physicochemical properties and fatty acid composition of Averrohoa carambola seed oil were determined. Physicochemical properties were determined using standard techniques and the fatty acid profile was obtained using Gas Chromatography Mass Spectroscopy (GC-MS). Soxhlet extraction (using petroleum ether) of the oil from sundried and crushed seeds of Averrohoa carambola gave light yellow oil with a yield of 28.45% oil per 100 g of the seeds. Other physicochemical properties of the oil determined were as follows; moisture content (7.2%), specific gravity (0.705), refractive index (1.421), acid value (0.68), free fatty acid (0.84), iodine value (140.50 g I2 100 g-1), saponification value (190.0 mg KOH g-1) and peroxide value (16.0 mEq kg-1). The fatty acid profiles were revealed using Gas Chromatography Mass Spectroscopy (GC-MS). Linoleic (36.01%) and oleic (34.05%) were detected as the major fatty acid while palmitic (6.75%) and stearic acid (3.09%) were the saturated acid found in the oil. The compositions of the saturated fatty acids (SAFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were found to be 10.43, 34.44 and 51.98% respectively. Hence, the oil has a relatively high percentage of unsaturated fatty acid (86.42%). The outcome of this study showed that Averrohoa carambola seed oil may find wider industrial application and could be a nutriceutical resource or functional foods ingredient. Hence, the oil may be edible subject to toxicological test.© 2016 International Formulae Group. All rights reserved.Keywords: Characterization, levels, saturated, monounsaturated, polyunsaturated, standard technique

    Design And Implementation of Android Based Voip System for Noise Pollution Control

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    Noise pollution happens to be a menace that the world is currently fighting hence, a way of controlling such pollution is needed so that in the event of passing information to a particular individual or group such information will land on the table of the recipient without constituting a menace to those around. The application of Information and Communication Technology ICT is therefore envisaged in solving this problem especially in environment where ICT is the order of the day. This paper, therefore, proposes a technological approach to solving this problem; the design and implementation of a Voice over Inter-Protocol VoIP as a means of sending voice messages from one android application to another, over a wireless network to individual, groups etc. The android platform was chosen because of its merit in portability and been able to connect to the internet easily. The VoIP has been designed, implemented and tested within the halls of residence of Covenant University, Nigeria and the result was satisfactory hence, acceptability of this work will show a great reduction in noise pollution in tertiary institutions, places of worships, and every other open spaces, events where messages need to be sent but to the specific recipient

    How to determine the parameters of polymer crystallization for modeling the injection-molding process?

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    International audienceTo understand the relationship between 'polymers-processing conditions-structures-properties', crystallization is one of the major concerned phenomena. A general crystallization model derived from Avrami's work has been developed at CEMEF and implemented into a 3D finite element code for injection-molding named Rem3D®. It gives a precise description of the crystallization event, allows the determination of morphological features, but it requires a reliable determination of the crystallization parameters. The experimental procedures adopted to capture relevant experimental parameters are presented. The determination of overall kinetics, density of potential nuclei with activation frequency of nuclei into crystalline entities, and growth rate is carried out with polarized optical microscopy (POM) and is supplemented by small angle light scattering (SALS). The treatment of data is performed by a classical method or using an inverse genetic algorithm method to extract the parameters necessary to our model. The 2D simulation of the crystallization, illustrated with Rem3D®, reproduces the experimental reality quite accurately, in the case of an isothermal and static crystallization. This is applied to two polymers, an isotactic homopolymer polypropylene iPP and a polyether-block amide PEBAX®

    Universal finite size corrections and the central charge in non solvable Ising models

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    We investigate a non solvable two-dimensional ferromagnetic Ising model with nearest neighbor plus weak finite range interactions of strength \lambda. We rigorously establish one of the predictions of Conformal Field Theory (CFT), namely the fact that at the critical temperature the finite size corrections to the free energy are universal, in the sense that they are exactly independent of the interaction. The corresponding central charge, defined in terms of the coefficient of the first subleading term to the free energy, as proposed by Affleck and Blote-Cardy-Nightingale, is constant and equal to 1/2 for all 0<\lambda<\lambda_0 and \lambda_0 a small but finite convergence radius. This is one of the very few cases where the predictions of CFT can be rigorously verified starting from a microscopic non solvable statistical model. The proof uses a combination of rigorous renormalization group methods with a novel partition function inequality, valid for ferromagnetic interactions.Comment: 43 pages, 1 figur

    Aligning integrated assessment modelling with socio-technical transition insights: an application to low-carbon energy scenario analysis in Europe

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    In this study, we present and apply an interdisciplinary approach that systematically draws qualitative insights from socio-technical transition studies to develop new quantitative scenarios for integrated assessment modelling. We identify the transition narrative as an analytical bridge between socio-technical transition studies and integrated assessment modelling. Conceptual interaction is realised through the development of two contrasting transition narratives on the role of actors in meeting the European Unions' 80% greenhouse gas emission reduction objective for 2050. The first transition narrative outlines how large-scale innovation trajectories are driven by incumbent actors, whereas the second transition narrative assumes more ‘alternative’ strategies by new entrants with strong opposition to large-scale technologies. We use the multi-level perspective to draw out plausible storylines on actor positioning and momentum of change for several technological and social niche-innovations in both transition narratives. These storylines are then translated into quantitative scenarios for integrated assessment modelling. Although both developed transition pathways align with the European Union's low-carbon objective for 2050, we find that each pathway depicts a substantial departure from systems that are known to date. Future research could focus on further systematic (joint) development of operational links between the two analytical approaches, as well as work on improved representation of demand-oriented solutions in techno-economic modelling

    Racial differences in user experiences and perceived value of electronic symptom monitoring in a cohort of black and white bladder and prostate cancer patients

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    Purpose: Electronic patient-reported outcomes (ePROs) are increasingly being used for symptom monitoring during routine cancer care, but have rarely been evaluated in diverse patient populations. We assessed ePRO user experiences and perceived value among Black and White cancer patients. Methods: We recruited 30 Black and 49 White bladder and prostate cancer patients from a single institution. Participants reported symptoms using either a web-based or automated telephone interface over 3 months and completed satisfaction surveys and qualitative interviews focused on user experiences and value. Using a narrative mixed methods approach, we evaluated overall and race-specific differences in ePRO user experiences and perceived value. Results: Most participants selected the web-based system, but Blacks were more likely to use the automated telephone-based system than Whites. In satisfaction surveys, Whites more commonly reported ease in understanding and reporting symptoms compared with Blacks. Blacks more often reported that the ePRO system was helpful in facilitating symptom-related discussions with clinicians. During interviews, Blacks described how the ePRO helped them recognize symptoms, while Whites found value in better understanding and tracking symptoms longitudinally. Blacks also expressed preferences for paper-based ePRO options due to perceived ease in better understanding of symptom items. Conclusion: Electronic patient-reported outcomes are perceived as valuable for variable reasons by Black and White cancer populations, with greater perceived value for communicating with clinicians reported among Blacks. To optimize equitable uptake of ePROs, oncology practices should offer several ePRO options (e.g., web-based, phone-based), as well as paper-based options, and consider the e-health literacy needs of patients during implementation

    The center effect in liver transplantation in the Eurotransplant region : a retrospective database analysis

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    Apart from donor and recipient risk factors, the effect of center-related factors has significant impact on graft survival after liver transplantation (LT). To investigate this effect in Eurotransplant, a retrospective database analysis was performed, including all LT's in adult recipients (18years) in the Eurotransplant region from 1.1.2007 until 31.12.2013. Additionally, a survey was sent out to all transplant centers requesting information on surgeons' experience and exposure. In total, 10265 LT's were included (median follow-up 3.3years), performed in 39 transplant centers. Funnel plots showed significant differences in graft survival between the transplant centers. After correction for donor and recipient risk, with the Eurotransplant donor risk index (ET-DRI) and the simplified recipient risk index (sRRI) and random effects, these differences diminished. Mean historical volume (in the preceding 5years) was a significant (P<0.001), nonlinear marker for graft survival in the multivariate analysis. This study demonstrates that funnel plots can be used for benchmarking purposes in LT. Case-mix correction can be performed with the use of the ET-DRI and sRRI. The center effect encompasses the entire complex process of preoperative workup, operation to follow-up

    Charge Fluctuations and Counterion Condensation

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    We predict a condensation phenomenon in an overall neutral system, consisting of a single charged plate and its oppositely charged counterions. Based on the ``two-fluid'' model, in which the counterions are divided into a ``free'' and a ``condensed'' fraction, we argue that for high surface charge, fluctuations can lead to a phase transition in which a large fraction of counterions is condensed. Furthermore, we show that depending on the valence, the condensation is either a first-order or a smooth transition.Comment: 16 pages, 1 figure, accepted to be published in PR
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