A structural optimization approach in process synthesis—I : Utility systems

A mixed-integer linear programming approach is presented for performing structural and parameter optimization in the synthesis of processing systems. This approach is applied to the synthesis of utility systems that have to provide fixed demands of electricity, power for drivers and steam at various pressure levels. A superstructure that has embedded many potential configurations of utility systems is proposed, as well as its corresponding mixed-integer programming model. The application of the model is illustrated with a large example problem.     

Recursive and Residual Algorithms for the Efficient Numerical Integration of Multi-Body Systems

In this paper a family of methods for multi-body dynamic simulation is introduced. Equations of motion are obtained using a set of Cartesian coordinates and projected onto a set of independent relative coordinates using the concept of velocity transformation. Open-chain systems are solved directly following either a fully recursive or a semi-recursive procedure. Closed-chain systems are solved in two steps; kinematic loops are opened by removing either some kinematic joints or a rigid body, and the resulting open-chain system is solved; closure-of-the-loop conditions are imposed by means of a second velocity transformation. The dynamic formalisms have been developed so as to handle both non-stiff and stiff systems. Non-stiff systems are solved by means of an Adams–Bashforth–Moulton numerical integration scheme, which requires the computation of the function derivatives. Stiff problems are integrated by using either BDF or NDF methods, which require the computation of the residual of the equations of motion and, optionally, the evaluation of the Jacobian matrix. The proposed algorithms have been implemented using an Object-Oriented Programming approach that makes it possible to re-use the source code, keeping programs smaller, cleaner and easier to maintain. Practical examples that illustrate the performance of these implementations are included. These examples have also been solved using a commercial multi-body simulation package and comparative results are included. In most cases, the algorithms here presented outperform those implemented in the commercial package, leading to important savings in terms of total computation times.     

Labyrinth, an abstract model for hypermedia applications. Description of its static components

In information technology, models are abstract devices to represent the components and functions of software applications. When a model is general and consistent, it represents a useful design tool to unambiguously describe the application. Traditional models are not suitable for the design of hypermedia systems and, therefore, specific design models and methodologies are needed. In the present article, the requirements for such models are analysed, an overview of the characteristics of the existing models for hypermedia applications is made and an abstract model fulfilling the analysed requirements is presented. The model, called Labyrinth, allows 1) the design of platform-independent hypermedia applications; 2) the categorisation, generalisation and abstraction of sparse unstructured heterogeneous information in multiple and interconnected levels; 3) the creation of personalisations (personal views) in multiuser hyperdocuments for both groups and individual users and 4) the design of advanced security mechanisms for hypermedia applications.     

A conceptual framework for combining artificial intelligence and optimization in engineering design

Research in artificial intelligence and optimization (OR) has had significant impact on the formulation and solution of computational methods in engineering design. This paper presents a conceptual framework for understanding a more powerful technology that is evolving from a combination of these approaches. The paper first proposes generalized representations of engineering design models that involve quantitative and qualitative aspects. Second, it presents a general classification of AI and OR models in terms of model attributes, in order to establish mappings with generic solution techniques. Third, the requirements of solution methods are discussed, as well as several schemes for the integration of AI and optimization to identify future research directions. Several specific approaches are included to illustrate various ways in which AI and optimization can be combined for tackling computational design models.     

Common interventions in two single cases of cognitive and psychoanalytic psychotherapies.

The aim of this study was to examine the interventions used in two nonmanualized psychotherapeutic treatments—one cognitive and one psychoanalytically oriented—; assessing the theoretical framework's pervasiveness in terms of the specificity of the interventions implemented by the psychotherapists. Our purpose was to observe which proportion of the therapists' interventions were directly associated with their theoretical background, and which proportion of them represented common, nonspecific or specific interventions. For this research, 29 sessions from a psychoanalytic psychotherapeutic treatment and 15 sessions from a cognitive psychotherapeutic treatment (both audio-recorded and transcribed), were analyzed. The classifications of psychotherapeutic interventions developed by Roussos, Etchebarne, and Waizmann (2005; Roussos, Waizmann, and Etchebarne, 2003) were used in order to characterize the interventions. Results show that both treatments were highly impregnated by nonspecific interventions. Only an average of 17% of the interventions in the psychoanalytic treatment and a 16% in the cognitive treatment, were specific of the theoretical frameworks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design and performance evaluation of a PMIPv6 solution for geonetworking-based VANETs

Vehicular Ad hoc NETworks (VANETs) are considered as the most suitable technology to provide vehicles with communication capabilities as a mean to improve road safety. Additionally, VANETs also open the market to non-safety applications where Internet connectivity is the main focus. Internet access from VANETs can be provided with the support of gateways located at the side of the roads, such that vehicles change their point of attachment to the Internet maintaining ongoing communications while they move. In this paper we tackle the problem of providing Internet access from VANETs combining the Proxy Mobile IPv6 (PMIPv6) with the ETSI TC ITS GeoNetworking (GN) protocols. We study how to adapt PMIPv6 to the multi-hop ETSI TC ITS architecture. A key contribution of this work is the design and analysis of different mechanisms that can be applied to the solution to improve the overall performance. A detailed performance evaluation of the solution and the different mechanisms assessing their influence is conducted by means of simulation under real traffic traces of an important orbital highway of Madrid.     

Effect of hydrostatic high-pressure treatment on proteins, lipids and nucleotides in chilled farmed salmon (Oncorhynchus kisutch) muscle

The effect of a previous hydrostatic high-pressure (HHP) treatment on hydrolysis, breakdown and aggregation events in chemical constituents of chilled farmed coho salmon (Oncorhynchus kisutch) was studied. Three different HHP conditions were applied (135 MPa-30 s; 170 MPa-30 s; 200 MPa-30 s; treatments T-1, T-2 and T-3, respectively) and compared to untreated fish for a 20-day chilled storage. Nucleotide degradation was important during the chilled storage in all kinds of samples; however, the K value did not afford differences related to previous pressure applied. HHP treatment led to an increased free fatty acid (FFA) formation (day 0 values); on the contrary, an inhibitory effect on FFA formation could be observed at the end of the storage (15–20 days) in T-3-treated fish as a result of microbial activity inhibition. A marked decrease in sarcoplasmic protein content was evident in samples corresponding to T-2 and T-3 treatments; the SDS–PAGE analysis of such protein fraction showed a partial loss of a band corresponding to 29 kDa. This band was excised, digested with trypsin, analysed by tandem mass spectrometry and identified as phosphoglycerate mutase.     

Technicalities of endoscopic biopsy

Despite the wealth of biopsy forceps currently available, it is obvious that there are sufficient drawbacks and shortcomings to reconsider the overall design of the endoscopic biopsy depth, the short lifespan of reusable forceps, damage to the working channel, excessive time consumption, cleaning and disinfection difficulties, etc. Improvements should be possible that approach the same degree of sophistication as is currently available in endoscopic equipment. Fully-automated, repetitive, quickly targeted biopsy sampling should be possible, but it will require the utmost technical ingenuity and expertise to achieve.