2,028 research outputs found
Tree-oriented interactive processing with an application to theorem-proving, appendix E
The concept of unstructured structure editing and ted, an editor for unstructured trees, is described. Ted is used to manipulate hierarchies of information in an unrestricted manner. The tool was implemented and applied to the problem of organizing formal proofs. As a proof management tool, it maintains the validity of a proof and its constituent lemmas independently from the methods used to validate the proof. It includes an adaptable interface which may be used to invoke theorem provers and other aids to proof construction. Using ted, a user may construct, maintain, and verify formal proofs using a variety of theorem provers, proof checkers, and formatters
Melt blown polypropylene nanofiber template for homogenous pore channels monoliths
Monoliths are an important technology for filtration, liquid chromatography, and protein purification. A template commonly uses to produce porous monolith. However, it is a challenge to produce a monolith with a homogenous porous structure due to the arrangements of pores within the monolith are often uneven and sometimes closed, causing pressure to accumulate and increase within the monolith which reduce the efficiency of the monoliths. Therefore, an appropriate template is needed to produce a monolith with homogenous porous structure. Nanofiber is a potential alternative as a template due to its high porosity and interconnectivity. Therefore, this research aimed to investigate the potential of polypropylene melt blown nanofiber fabricated at various operating condition to fabricate monolith by assessing the monolith morphology. Nanofibers templates were produced using a melt blowing technique at various motor speeds, air pressures, and die-to-collector distance (DCD) between
30 and 50 Hz, 0.30 and 0.50 Mpa, and 20 and 50 cm respectively, design by Response Surface Methodology. The nanofibers were characterized for its morphology and melting point using scanning electron microscope (SEM) and molten point analysis instrument respectively. The findings show that the polypropylene nanofiber diameter was in the range of 3.58 to 11.00 x 103 nm. Meanwhile, melting point obtained were in the range of 121.0 to 128.8 °C. Subsequently macropores monoliths were successfully fabricated at 0.45 Mpa air pressure, 40 Hz motor speed and 60.23 cm die-to-collector distance. It can be concluded that, melt blown polypropylene
nanofiber can be potentially applied as a template for monolith fabrication
Renormalizing Partial Differential Equations
In this review paper, we explain how to apply Renormalization Group ideas to
the analysis of the long-time asymptotics of solutions of partial differential
equations. We illustrate the method on several examples of nonlinear parabolic
equations. We discuss many applications, including the stability of profiles
and fronts in the Ginzburg-Landau equation, anomalous scaling laws in
reaction-diffusion equations, and the shape of a solution near a blow-up point.Comment: 34 pages, Latex; [email protected]; [email protected]
Use of melt blown polypropylene nanofiber templates to obtain homogenous pore channels in glycidyl methacrylate/ethyl dimethacrylate-based monoliths
An important characteristic of a monolith is its porous structure. However, it is difficult to obtain a homogenous porous structure in a monolith due to dead-end and uneven distributions of pores, but nanofibers can act as templates to induce a porous structure. Hence, the aim of this research was to study melt-blown polypropylene nanofibers produced under process conditions designed by response surface methodology (RSM), i.e., air pressures between 0.30 and 0.50 MPa, motor speeds between 30 and 50 Hz, and die-to-collector distances between 20 and 50 cm. The air pressure was found to be an important factor in determining the diameters of the fibers from the RSM analysis, and we found the diameters to be between 3.58 and 11.00 × 103 nm. Macropore monoliths were fabricated successfully with conditions of 0.45 MPa, 40 Hz, and 60.23 cm. Thus, it was concluded that polypropylene nanofibers can be used as a template to produce a monolith
A Bio-Logical Theory of Animal Learning
This article provides the foundation for a new predictive theory of animal learning that is based upon a simple logical model. The knowledge of experimental subjects at a given time is described using logical equations. These logical equations are then used to predict a subject’s response when presented with a known or a previously unknown situation. This new theory suc- cessfully anticipates phenomena that existing theories predict, as well as phenomena that they cannot. It provides a theoretical account for phenomena that are beyond the domain of existing models, such as extinction and the detection of novelty, from which “external inhibition” can be explained. Examples of the methods applied to make predictions are given using previously published results. The present theory proposes a new way to envision the minimal functions of the nervous system, and provides possible new insights into the way that brains ultimately create and use knowledge about the world
Do rats learn conditional independence?
If acquired associations are to accurately represent real relevance relations, there is motivation for the hypothesis that learning will, in some circumstances, be more appropriately modelled, not as direct dependence, but as conditional independence. In a serial compound conditioning experiment, two groups of rats were presented with a conditioned stimulus (CS1) that imperfectly (50%) predicted food, and was itself imperfectly predicted by a CS2. Groups differed in the proportion of CS2 presentations that were ultimately followed by food (25% versus 75%). Thus, the information presented regarding the relevance of CS2 to food was ambiguous between direct dependence and conditional independence (given CS1). If rats learnt that food was conditionally independent of CS2, given CS1, subjects of both groups should thereafter respond similarly to CS2 alone. Contrary to the conditionality hypothesis, subjects attended to the direct food predictability of CS2, suggesting that rats treat even distal stimuli in a CS sequence as immediately relevant to food, not conditional on an intermediate stimulus. These results urge caution in representing indirect associations as conditional associations, accentuate the theoretical weight of the Markov condition in graphical models, and challenge theories to articulate the conditions under which animals are expected to learn conditional associations, if ever.All funding for the project was internal, from Indiana University
Can the internet reduce the loneliness of 50+ living alone?
Published online: 12 May 2020Living alone has been indicated as a key variable to explain loneliness in older adults. In contemporary society, where technology has become one of the main means of communication and personal interaction, has the internet influenced the relationship between living alone and loneliness? This paper aims to answer this research question by using a sample of 64,297 individuals who were surveyed in SHARE project wave 6 – in European countries with different welfare regimes (Portugal, Greece, Italy and Spain, Denmark, Sweden, Austria, Belgium, France, Germany, Switzerland, Luxemburg, Poland, Czech Republic; Slovenia, Estonia, and Croatia). The results of the regression analysis evidence the moderating
role of the internet on the relationship between living alone and feelings of loneliness in individuals aged 50 and over, so that the impact of living alone on loneliness is diminished for internet users as compared to their peers who do not use the internet. The results therefore reinforce the importance of policies aimed at fostering e-inclusion as a way of reducing the loneliness of older adultsThis work was supported by European Commission; Fundação para a Ciência e a Tecnologia; U.S National Institute on Aging; Fundação Calouste Gulbenkian; German Ministry of Education and Researc
Potential of a cyclone prototype spacer to improve in vitro dry powder delivery
Copyright The Author(s) 2013. This article is published with open access at Springerlink.com. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPurpose: Low inspiratory force in patients with lung disease is associated with poor deagglomeration and high throat deposition when using dry powder inhalers (DPIs). The potential of two reverse flow cyclone prototypes as spacers for commercial carrierbased DPIs was investigated. Methods: Cyclohaler®, Accuhaler® and Easyhaler® were tested with and without the spacers between 30-60 Lmin-1. Deposition of particles in the next generation impactor and within the devices was determined by high performance liquid chromatography. Results: Reduced induction port deposition of the emitted particles from the cyclones was observed due to the high retention of the drug within the spacers (e.g. salbutamol sulphate (SS): 67.89 ± 6.51 % at 30 Lmin-1 in Cheng 1). Fine particle fractions of aerosol as emitted from the cyclones were substantially higher than the DPIs alone. Moreover, the aerodynamic diameters of particles emitted from the cyclones were halved compared to the DPIs alone (e.g. SS from the Cyclohaler® at 4 kPa: 1.08 ± 0.05 μm vs. 3.00 ± 0.12 μm, with and without Cheng 2, respectively) and unaltered with increased flow rates. Conclusion: This work has shown the potential of employing a cyclone spacer for commercial carrier-based DPIs to improve inhaled drug delivery.Peer reviewe
Online Optimization of Complex Transportation Systems
This paper discusses online optimization of real-world transportation systems. We concentrate on transportation problems arising in production and manufacturing processes, in particular in company internal logistics. We describe basic techniques to design online optimization algorithms for such systems, but our main focus is decision support for the planner: which online algorithm is the most appropriate one in a particular setting? We show by means of several examples that traditional methods for the evaluation of online algorithms often do not suffice to judge the strengths and weaknesses of online algorithms. We present modifications of well-known evaluation techniques and some new methods, and we argue that the selection of an online algorithm to be employed in practice should be based on a sound combination of several theoretical and practical evaluation criteria, including simulation
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