Efficient pebbling for list traversal synopses with application to program rollback

We show how to support efficient back traversal in a unidirectional list, using small memory and with essentially no slowdown in forward steps. Using O(lgn)$O(lgn)$ memory for a list of size n$n$, the i$i$’th back-step from the farthest point reached so far takes O(lgi)$O(lgi)$ time in the worst case, while the overhead per forward step is at most ?$?$ for arbitrary small constant ?>0$?>0$. An arbitrary sequence of forward and back steps is allowed. A full trade-off between memory usage and time per back-step is presented: k$k$ vs. kn^1/k$k{n}^{1/k}$ and vice versa. Our algorithms are based on a novel pebbling technique which moves pebbles on a virtual binary, or n^1/k$n^{1/k}$-ary, tree that can only be traversed in a pre-order fashion.     

ESA-based in-fiber nanocavity for hydrogen-peroxide detection

A fiber-optic sensor sensitive to hydrogen peroxide has been designed based on the electrostatic layer-by-layer self-assembly method. Prussian blue has been deposited in a polymeric structure formed by Poly(allylamine hydrochloride) and poly(acrylic acid). The concentration that can be detected range between 10/sup -6/-10/sup -3/ M, and recovery of the sensor after immersion into a reductive agent was demonstrated. The response of the sensor is independent of the pH for values that range between 4-7.4. Some rules for estimation of the refractive index of the material deposited and the thickness of the bilayers are also presented.     

Software process representation and analysis for framework instantiation

Object-oriented frameworks are currently regarded as a promising technology for reusing designs and implementations. However, developers find there is still a steep learning curve when extracting the design rationale and understanding the framework documentation during framework instantiation. Thus, instantiation is a costly process in terms of time, people, and other resources. These problems raise a number of questions including: "How can we raise the level of abstraction in which the framework instantiation is expressed, reasoned about and implemented?" "How can the same high-level design abstractions that were used to develop the framework be used during framework instantiation instead of using source code as is done currently?" "How can we define extended design abstractions that can allow framework instantiation to be explicitly represented and validated?" We present an approach to framework instantiation based on software processes that addresses these issues. Our main goal is to represent the framework design models in an explicit and declarative way, and support changes to this design based on explicit instantiation tasks based on software processes while maintaining system integrity, invariants, and general constraints. In this way, the framework instantiation can be performed in a valid and controlled way.     

Web-GIS models: accomplishing modularity with aspects

Spatial concerns of Web geographical information systems (Web-GIS) are inherently crosscutting and volatile: crosscutting because they affect multiple functionalities of Web-GIS systems, and volatile because their status may change often. If these concerns are not modularized properly, the quality of Web-GIS services, particularly with regard to adaptation and evolution, can be severely compromised. This paper uses aspect-orientation to model crosscutting and volatile spatial concerns. By modeling both types of concerns, crosscutting and volatile, as candidate aspects, one can use dynamic weaving to add or remove them from a system at runtime. The aspect-oriented approach proposed starts with the identification and specification of crosscutting concerns and follows by composing these using modeling aspects using a transformation approach, an aspect-oriented modeling technique. The conflicts that can emerge due to the composition order are also taken into consideration. Finally, this paper proposes a set of reusable GIS crosscutting concerns, documenting them in a concern catalogue.     

Physiological compliance for social gaming analysis: Cooperative versus competitive play

We report the results of an empirical study demonstrating the value of using physiological compliance as a measure of social presence during digital game playing. The physiological activity (facial EMG, electrodermal activity, cardiac activity and respiration) of 21 dyads were acquired synchronously while they were playing a digital game either cooperatively or competitively and either at home or in the laboratory. Physiological compliance was defined as the correlation between the physiological signals of the dyad members. The results of this study confirm that physiological compliance is higher in a conflicting situation than when playing cooperatively. Importantly, the results also demonstrate that physiological compliance is related to self-reported social presence. This suggests that physiological compliance is not limited to negative situations but rather increases due to rich interactions. Only minor differences in physiological compliance were observed between home play and laboratory play, suggesting the ecological validity of laboratory measures. Finally, we propose that compliance measures can be considered as objective indices of social presence in digital gaming.     

Development of a special geometry carbide tool for the optimization of vertical turning of martensitic gray cast iron piston rings

The machining process for vertical turning martensitic gray cast iron is of great importance to the automotive industry, mainly in the manufacturing process of piston rings. The aim of this paper is to demonstrate the process of development of coated carbide tools to maximize the productivity of the process, considering the maximum life of the cutting tool and the minimum machining cost per part. Using full-factorial design of experiments, we tested two different geometries: a square tool with special geometry—formed by two edges and two ends simultaneously cutting—and a hexagonal tool. Considering that the special square geometry provided maximum life, full quadratic models for responses of interest were constructed using a central composite design for feed (f) and rotation (n). Applying the generalized reduced gradient algorithm, the proposed optimization goals were achieved with feed f?=?0.37?mm/v and rotation of 264?rpm for the use of the special square tool. Confirmation experiments prove the effectiveness of this solution.     

Near-infrared spectroscopy to assist authentication and labeling of Asiago d’allevo cheese

This study investigated the possibility of using near-infrared spectroscopy (NIRS) for the authentication of Asiago d’allevo, a protected designation of origin cheese from northern Italy. Latent variable models applied on spectral data were developed and used to estimate several chemical properties and to classify the available dataset according to the location and management of the cheesemaking factory (lowland and alpine), the ripening age (6, 12, 18 and 36 months), the altitude of milk production (low, medium, medium–high and high), and the period of the year of the cheese production (May, July and September). The variable importance in projection index was used to identify the most informative spectral regions for discrimination. Results showed that NIR spectra can be used both to accurately estimate several chemical properties and to classify the samples according to the different experimental conditions under investigation with the same discrimination capacity provided by traditional chemical analysis.