Comparative analysis of methods for determining the metabolic rate in order to provide a balance between man and the environment

The incorrect determination of metabolic rate can be linked to discrepancies between the model of the PMV (Predicted Mean Vote) and real thermal sensation collected in field studies. Aiming to improve the correlation of the PMV model and the real thermal sensation, this work established new values for the metabolic rate: one way being called “calculated” using Newton's Method and the other called "measured" using a metabolic analyzer. Welder's activities were evaluated, through the measurements of environmental and personal variables. New values of metabolic rate were determined for this activity. The values found for the calculated form and the measured one were, respectively, 178.63 and 145.46 W/m², different from the range provided by the table of ISO 8996 (2004) for this activity (75–125 W/m²). In order to verify which of the values of the metabolic rate was closer to the real thermal sensation of PMV, a linear regression was made between the PMV and the real thermal sensation in three ways: S × PMV_tabulated (R² = 0.1749), S × PMV_calculated (R ² = 0.7481) and S × PMV_measured (R² = 0.7854). It was found that the values measured by the instrument gave a higher coefficient of determination which was chosen for the correction of the table. The correction of the table provides a value of M_predicted, that is a value of metabolic rate that corrects the values provided by the tables of ISO 8996 (2004), by means of a correction coefficient. For the welder's activities in a metal-mechanics industry, tabulated values can be multiplied by the correction coefficient 1.4648 in order to minimize inaccuracies. The PMV_predicted, obtained through the M_predicted, when related to the actual thermal sensation, provides a coefficient of determination of 0.7511, thereby improving the model of the PMV.     

A computational model for developing semantic web-based educational systems

Recently, some initiatives to start the so-called semantic web-based educational systems (SWBES) have emerged in the field of artificial intelligence in education (AIED). The main idea is to incorporate semantic web resources to the design of AIED systems aiming to update their architectures to provide more adaptability, robustness and richer learning environments. However, the construction of such systems is highly complex and faces several challenges in terms of software engineering and artificial intelligence aspects. This paper presents a computational model for developing SWBES focusing on the problem of how to make the development easier and more useful for both developers and authors. In order to illustrate the features of the proposed model, a case study is presented. Furthermore, a discussion about the results regarding the computational model construction is available.     

Improvement of processing and mechanical properties of polyetherimide by antiplasticization with resorcinol bis(diphenyl phosphate)

This article describes the antiplasticization of a commercial polyetherimide ULTEM® series 1000 [poly(bisphenol A‐co‐4‐nitrophthalic anhydride‐co‐1,3‐phenylenediamine) by resorcinol bis(diphenyl phosphate)] (RDP) and its implications on the thermomechanical processing, namely extrusion and injection molding, as well as on the thermal and mechanical properties of the formulations. This antiplasticization effect allows the processing of polyetherimide formulations at lower temperatures in comparison with neat polymer due to the progressive decrease of the glass transition temperature with increased RDP concentration, as observed by differential scanning calorimetry and dynamic mechanical analysis. The decrease of T_g occurs concomitantly with the overlap of the glass transition and β relaxation and with the shift of the γ relaxation to higher temperatures. These changes in the relaxation spectrum of polyetherimide formulations are possibly responsible for the increase of the tensile strength and Young's modulus and changes in the fracture mechanism, as observed by stress–strain tests and by scanning electron microscopy, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40619.     

Structured context-analysis techniques in biologically inspired ambient-intelligence systems

In this paper, techniques and related issues for the definition of a contextual knowledge in ambient-intelligence systems are explored. A logical structure for this kind of system, inspired by a neurobiological brain model, is proposed. Through these considerations, the role and the importance of context awareness in the definition of an artificial organism showing adaptability, pervasiveness, and scalability features are described. Techniques for the definition of a multilayer context representation are explained and practically demonstrated with a test-bed. In the proposed system, a complex event classification is obtained through the fusion of heterogeneous data coming from a set of sensors thanks to the design of a self-organizing map (SOM). The SOM represents the core of the system and testing proofs show good results in the classification of the events taking place in the monitored environment.     

Managing copyright in open networks

The need for an electronic copyright management system (ECMS) that protects intellectual property rights (IPR) in open network environments continues to grow. Network security issues are classically handled through cryptography; however, cryptography ensures confidentiality, authenticity, and integrity only when a message is transmitted through a public channel, such as an open network. It does not protect against unauthorized copying after the message has been successfully transmitted. Digital watermarking is an effective way to protect copyright of multimedia data even after its transmission. A watermark, embedded in the data, can uniquely identify the document's owner or authorized user. The main problem with using watermark technology, for IPR protection, however, is its reversibility. Anyone who can read or detect the watermark can also remove it by inverting the watermark process. Our open network ECMS combines watermarking with cryptography to achieve reliable copyright protection while satisfying two contrasting requirements: actors in ECMS transactions must be able to verify that the watermark granting their rights is truly embedded in the multimedia document; and actors (other than the author) must not be able to remove the watermark     

Fracture behaviour by two cracks around an elliptic rigid inclusion

An analysis is presented for the in-plane biaxial loading of an elastic system consisting of a partially bonded rigid elliptic inclusion embedded in an infinite matrix where the bond imperfections are two symmetric cracks. The boundary value problem is formulated through the complex variable technique in the case of linearly elastic matrix under general biaxial loading at infinity. The elastic solution is obtained for a simplified model by assuming incompressibility and plane strain conditions for the matrix. In particular, stress and displacement fields are represented and discussed.

Moreover, a stress criterion, which permits to take into account, either the crack extension at the interface or its deviation into the matrix, is considered to study the fracture response of the elastic system.     

Enhancing the experience of 3D virtual worlds with a cartographic generalization approach

In this work we propose a new approach for fast visualization and exploration of virtual worlds based on the use of cartographic concepts and techniques. Versions of cartographic maps with different levels of details can be created by using a set of operations named cartographic generalization. Cartographic generalization employs twelve operators and domain-specific knowledge, being the contribution of this work their transposition to 3D virtual worlds. The architecture of a system for 3D generalization is proposed and the system is implemented. Differently from traditional cartographic processes, we use artificial intelligence for both selecting the key objects and applying the operators. As a case study, we present the simplification of the historical quarter of Recife (Brazil).     

Capacity of full frame DCT image watermarks

The evaluation of the number of bits that can be hidden within an image through digital watermarking is a crucial topic, which has been addressed only for additive watermarks. The evaluation of watermark capacity is very important because it allows to put a theoretical upper bound on the amount of information that can be hidden into an image by a given watermarking procedure, regardless of the watermark extraction technique. It is the purpose of this work to suggest a methodology for the evaluation of the watermark capacity in a nonadditive, non-Gaussian framework, and to discuss the results we obtained by applying it to a set of standard images.     

Benzodioxoles as alternative coinitiators for radical polymerization in a model‐dental adhesive resin

This study evaluated the effectiveness of benzodioxole derivatives as coinitiators of radical polymerization in a model‐dental adhesive resin. To compose the adhesive resin, a monomer mixture based on 50 wt % of Bis‐GMA, 25 wt % of TEGDMA, and 25 wt % of HEMA was used. Camphorquinone (CQ) 1 mol % was used as a photoinitiator to initiate polymerization. 1,3‐Benzodioxole (BDO) and piperonyl alcohol (PA) were used as coinitiators at 0.25, 0.5, 1, 2, 4, 8, and 16 mol % level. In addition, tertiary amine, ethyl 4‐dimethylamino benzoate (EDAB) was used as coinitiator in the control group. Some physical, chemical, and mechanical properties of the polymer formed in the experimental adhesives were evaluated using the kinetics of polymerization, sorption and solubility, flexural strength, and elastic modulus tests. The results indicated that BDO and PA were effective coinitiators in the photoinitiator system based on CQ. Comparisons between the benzodioxoles derivative coinitiators and EDAB showed similar performance in the kinetics of polymerization and flexural strength. For water sorption and solubility evaluation, BDO and PA demonstrated significantly more sorption of water and less solubility than the EDAB control group. The findings suggest that BDO and PA were feasible alternatives to conventional amine as coinitiator. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Experimental and numerical investigation of the steady periodic solid-liquid phase-change heat transfer

A numerical and experimental investigation is presented of a periodic phase-change process dominated by heat conduction. In the experimental arrangement a plane slab of PCM is periodically heated from above. A one-dimensional control volume computer code has been developed for the solution of the corresponding mathematical model. The comparison between numerical predictions and experimental data shows good agreement, even though appreciable effects are produced by free convection and heat transfer to the environment, neglected in the model but unavoidable in the experiment. Finally, in order to study the energy stored in the process, parameters like amplitude and mean value of the oscillations are discussed as functions of the significant dimensionless numbers of the problem.