Optimal channel coordination in use-based product-service system contracts

Nowadays, service economy efficiencies are key to keep competitiveness and increase market advantages. The development of Product-Service Systems (PSS) can be an interesting strategy as they seek to improve the business performance of all the participants in the value chain. This paper proposes a novel reliability-based reward scheme for use-oriented PSS contracts. In a PSS instead of paying for the product, the client pays a fee for its performance. The contribution of this work to the existing literature is to provide a quantitative tool for the development of a use-oriented PSS contract based on non-repairable component reliability and risk sharing. It can be extended to other performance metrics such as availability and reliability. A well designed PSS achieves a mutual growth agreement for the client and the supplier if it aligns their interests through channel coordination. This is achieved by balancing the improvement in the expected cost and profit for the client and the supplier, respectively. The improvement is measured with respect to a baseline scenario where no PSS contract exists. The methodology is tested using a case study that analyses mining haul truck tires. The results show a significant overall improvement in the main key performance indicators and environmental impact of the value chain.     

Designing to Facilitate Browsing: A Look Back at the Hyperties Workstation Browser

Since browsing hypertext can present a formidable cognitive challenge, user interface design plays a major role in determining acceptability. In the Unix workstation version of Hyperties, a research-oriented prototype, we focussed on design features that facilitate browsing. We first give a general overview of Hyperties and its markup language. Customizable documents can be generated by the conditional text feature that enables dynamic and selective display of text and graphics. In addition we present: — an innovative solution to link identification: pop-out graphical buttons of arbitrary shape.

— application of pie menus to permit low cognitive load actions that reduce the distraction of common actions, such as page turning or window selection.

— multiple window selection strategies that reduce clutter and housekeeping effort. We preferred piles-of-tiles, in which standard-sized windows were arranged in a consistent pattern on the display and actions could be done rapidly, allowing users to concentrate on the contents.

     

Onset of virus systemic infection in plants is determined by speed of cell-to-cell movement and number of primary infection foci

The cornerstone of today''s plant virology consists of deciphering the molecular and mechanistic basis of host–pathogen interactions. Among these interactions, the onset of systemic infection is a fundamental variable in studying both within- and between-host infection dynamics, with implications in epidemiology. Here, we developed a mechanistic model using probabilistic and spatio-temporal concepts to explain dynamic signatures of virus systemic infection. The model dealt with the inherent characteristic of plant viruses to use two different and sequential stages for their within-host propagation: cell-to-cell movement from the initial infected cell and systemic spread by reaching the vascular system. We identified the speed of cell-to-cell movement and the number of primary infection foci in the inoculated leaf as the key factors governing this dynamic process. Our results allowed us to quantitatively understand the timing of the onset of systemic infection, describing this global process as a consequence of local spread of viral populations. Finally, we considered the significance of our predictions for the evolution of plant RNA viruses.     

Plant oil bioconversion into increase biological activity through lipases derived from wastes

The aim of this study was to show that abundant and inexpensive plant oils can be biotransformed to increase biological activity (antioxidant, antimicrobial and cytotoxicity) through hydrolysis reaction catalysed by lipases. We tested homemade and commercial lipases through the biotransformation of nine different plant oils in forty different combinations. First, the chemical composition of the samples was investigated. Thereafter, biological tests were conducted to assess the antioxidant and antimicrobial activity of the sampled biotransformation products, as well as analyzed their influence on the viability of healthy and cancer cells. Summarising, sunflower, corn and olive oils modified by orange waste-obtained lipases presented the most promising results, reaching up to 90% of antioxidant activity increase and significant growth inhibition of bacteria colonies belonging to genera Escherichia, Listeria, Staphylococcus, Pseudomonas and Salmonella. In addition, those compounds affected human oral squamous carcinoma cells. The bioconversion of plant oils through lipases improves their biological properties and might be an option for biotechnological application.     

Construction of baselines for VoIP traffic management on open MANs

In the last century, owing to the constant evolution of technologies telecommunication networks have become increasingly robust, being able to support multiple services. These services are part of the heterogeneous network traffic that can be carried through the Internet. Many of these services, including VoIP, are latency sensitive. In other words, this means that their quality depends directly on the network quality of service. Since users tend to become more sensitive with the instability and unavailability of the network, it is important to improve traffic management. A particular type of data that could be used to improve VoIP traffic management is the Internet Protocol Detail Record (IPDR). IPDRs are tickets created by all VoIP call attempts which contain a group of information related to the call history. Because of its full range of information, IPDRs can be used to create VoIP traffic baselines. This paper presents the development of baselines based on IPDRs to support VoIP traffic management in open‐access Metropolitan Area Networks (MAN). Copyright © 2013 John Wiley & Sons, Ltd.     

Algorithm transformation methods to reduce the overhead of software-based fault tolerance techniques

This paper introduces a framework that tackles the costs in area and energy consumed by methodologies like spatial or temporal redundancy with a different approach: given an algorithm, we find a transformation in which part of the computation involved is transformed into memory accesses. The precomputed data stored in memory can be protected then by applying traditional and well established ECC algorithms to provide fault tolerant hardware designs. At the same time, the transformation increases the performance of the system by reducing its execution time, which is then used by customized software-based fault tolerant techniques to protect the system without any degradation when compared to its original form. Application of this technique to key algorithms in a MP3 player, combined with a fault injection campaign, show that this approach increases fault tolerance up to 92%, without any performance degradation.     

Experimental analyses of the poly(vinyl chloride) foams' mechanical anisotropic behavior

Assessing a full set of mechanical properties is a rather complicate task in the case of foams, especially if material models must be calibrated with these results. Many issues, for example anisotropy and heterogeneity, influence the mechanical behavior. This article shows through experimental analyses how the microstructure affects different experimental setups and it also quantifies the degree of anisotropy of a poly(vinyl chloride) foam. Monotonic and cyclic experimental tests were carried out using standard compression specimens and non‐standard tensile specimens. Results are complemented and compared with the aid of a digital image correlation technique and scanning electron microscopy analyses. Mechanical properties (e.g., elastic and plastic Poisson's ratios) are evaluated for compression and tensile tests, for two different material directions (normal and in‐plane). The material is found to be transversely isotropic. Differences in the results of the mechanical properties can be as high as 100%, or even more depending on the technique used and the loading direction. Also, the experimental analyses show how the material's microstructure behavior, like the evolution of the herein identified “yield fronts” and a “spring back” phenomenon, can influence the phenomenological response and the failure mechanisms as well as the hardening curves. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

An Analysis of Public Clouds Elasticity in the Execution of Scientific Applications: a Survey

Elasticity can be seen as the ability of a system to increase or decrease the computing resources allocated in a dynamic and on demand way. It is an important feature provided by cloud computing, that has been widely used in web applications and is also gaining attention in the scientific community. Considering the possibilities of using elasticity in this context, a question arises: “Are the available public cloud solutions suitable to provide elasticity to scientific applications?” To answer the question, in a first moment we present a survey on the use of cloud computing in scientific scenarios, providing an overview of the subject. Next, we describe the elasticity mechanisms offered by major public cloud providers and analyzes the limitations of the solutions in providing elasticity for scientific applications. As the main contribution of the article, we also present an analysis over some initiatives that are being developed to overcome the current challenges. In our opinion, current computational clouds are developing rapidly but have not yet reached the necessary maturity level to meet all scientific applications elasticity requirements. We expect that in the coming years the efforts being taken by numerous researchers in this area identify and address these challenges and lead to better and more mature technologies that will improve cloud computing practices.     

On the use of ancillary data by applying the concepts of the theory of evidence to remote sensing digital image classification

In this study we investigate a new approach to implement concepts developed by the ‘theory of evidence’ to remote sensing digital image classification. In the proposed approach, auxiliary variables are structured as layers in a Geographical Information System (GIS)-like format to produce layers of belief and plausibility. Thresholds are applied to the layers of belief and plausibility to detect errors of commission and omission, respectively on the thematic image. The thresholds are estimated as functions of the user's and producer's accuracy. Preliminary tests were performed over an area covered by natural forest with Araucaria, showing some promising results.     

In vitro digestibility of phenolic compounds from edible fruits: could it be explained by chemometrics?

The health benefits of phenolic compounds depend on the ingested amount, molecular diversity and gastrointestinal digestibility. The phenolic profile of eight fruits (blackberry, blueberry, strawberry, raspberry, mulberry, pomegranate, green and red globe grapes) was chemometrically associated with their in vitro digestibility (oral, gastric, intestinal). Extractable phenols, flavonoids and anthocyanins strongly correlated with each other (r ≥ 0.84), proanthocyanidins with anthocyanins (r = 0.62) and hydrolysable phenols with both extractable phenols (r = 0.45) and proanthocyanidins (r = ?0.54). Two principal components explained 93% of the variance [61% (free‐phenols), 32% (bounded‐phenols)], and four clusters were confirmed by hierarchical analysis, based in their phenolic richness (CLT 1‐4: low to high) and molecular diversity. In vitro digestibility of extractable phenols and flavonoids was blackberry (CLT‐4)> raspberry (CLT‐2)> red grape (CLT‐1) related to their phenolic richness (r ≥ 0.96; P < 0.001), but anthocyanins’ digestibility was pH‐dependent. Chemometrics is useful to predict the in vitro digestibility of phenolic compounds in the assayed fruits.