Unsupervised neural models for country and political risk analysis

This interdisciplinary research project focuses on relevant applications of Knowledge Discovery and Artificial Neural Networks in order to identify and analyze levels of country, business and political risk. Its main goal is to help business decision-makers understand the dynamics within the emerging market countries in which they operate. Most of the neural models applied in this study are defined within the framework of unsupervised learning. They are based on Exploratory Projection Pursuit, Topology Preserving Maps and Curvilinear Component Analysis. Two interesting real data sets are analyzed to empirically probe the robustness of these models. The first case study describes information from a significant sample of Spanish multinational enterprises (MNEs). It analyses data pertaining to such aspects as decisions over the location of subsidiary enterprises in various regions across the world, the importance accorded to such decisions and the driving forces behind them. Through a projection-based analysis, this study reveals a range of different reasons underlying the internationalization strategies of Spanish MNEs and the different goals they pursue. It may be concluded that projection connectionist techniques are of immense assistance in the process of identifying the internationalization strategies of Spanish MNEs, their underlying motives and the goals they pursue. The second case study covers several risk categories that include task policy, security, and political stability among others, and it tracks the scores of different countries all over the world. Interesting conclusions are drawn from the application of several business intelligence solutions based on neural projection models, which support data analysis in the context of country and political risk analysis.     

Shear properties and load–deflection response of cross–ply glass–epoxy composite short–beams subjected to three‐point‐bending tests,and the effect of moisture absorption

The extensive use of composites in aerospace, chemical, marine, and structural applications leads to exposure to humidity and water immersion. Hence, there is a need to study the effect of moisture absorption on the mechanical properties of composite materials, especially the matrix dominated properties, such as the interlaminar shear strength (ILSS). The horizontal shear test with a short‐beam specimen in three‐point‐bending is used as a general method of evaluation for the shear properties in fiber‐reinforced composites because of its simplicity. In this work, the ILSS of cross‐ply glass‐epoxy resin composites is determined in seven different fiber directions with short‐beam three‐point‐bending tests, before and after moisture conditioning. It is found that moisture absorption reduces ILSS and stiffness of the examined composites whereas it leads to larger failure deflections. It is also found that the direction of fibers strongly affects the load–deflection response and the ILSS of the dry and conditioned specimens. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Novel Esterification of Glycerol Catalysed by Tin Chloride (II): A Recyclable and Less Corrosive Process for Production of Bio-Additives

Abstract  

In this work, a novel process based on use of a SnCl₂·2H₂O catalyst which is less corrosive, inexpensive, and a water tolerant Lewis acid was employed for synthesis of fuel bio-additives from glycerol. High yields and selectivities were achieved for glycerol esterification with acetic acid under mild reaction conditions. The SnCl₂ catalyst showed to be as active as p-toluene sulfonic and sulfuric acid, catalysts commonly used in acid-catalysed esterification reactions. However, its use has significant advantages in comparison to these Br?nsted acid catalysts, including lower reactor corrosion and unnecessary neutralization at the end reaction. The SnCl₂ catalyst can also be recovered and reused without loss of catalytic activity. Additionally, effects of reaction temperature, HOAc:glycerol molar ratio and catalyst concentration on both selectivity and yield of glycerol acetates were also investigated. The lower corrosiveness, facilitated handling, as well as potential for reuse without activity loss after simple recycle protocols are positive aspects of SnCl₂ catalysts.     

Isotropic Image Analysis for Improving CBR Forecasting

A novel hybrid forecasting Case-Based Reasoning (CBR) system is presented in this interdisciplinary study in which an isotropic buffer operator is applied for case-based creation. Commonly used as an image analysis technique by commercial Geographic Information Systems (GIS), the buffer operator in this particular system calculates the area of an oil slick for prediction and visualization tasks. The use of the buffer operator improves the quality of the data used by the system and in consequence the quality of the results obtained. The system generates predictions by using historical data on oil-slick formation following a spill.     

Enzymatic production of human milk fat substitutes containing palmitic and docosahexaenoic acids at sn-2 position and oleic acid at sn-1,3 positions

This paper studies the synthesis of structured triacylglycerols (STAGs) rich in palmitic and docosahexaenoic acids (PA and DHA) at sn-2 position and oleic acid (OA) at sn-1,3 positions by a four step process. First, triacylglycerols (TAGs) were obtained with 63–66 mol PA/100 mol total fatty acids and 10 mol DHA/100 mol by acidolysis of tuna oil and commercial PA, catalyzed by the non-positionally specific lipase Novozym 435. Then these TAGs were purified neutralizing the free fatty acids (FFAs) by KOH hydroethanolic solutions and extracting TAGs with hexane; these TAGs were completely recovered as pure TAGs (without FFAs). The third step involved the displacement of fatty acids located at sn-1,3 positions by acidolysis of PA and DHA enriched TAGs with OA rich FFAs, catalyzed by the sn-1,3 specific lipase DF from Rhizopus oryzae, immobilized on Accurel MP-1000; TAGs with 67 mol OA/100 mol at sn-1,3 positions and 52.1 and 15.4 mol PA and DHA, respectively, per 100 mol at sn-2 position were obtained. Both acidolysis reactions were carried out in stirred tank reactors (STRs) with lipase both dispersed in the reaction medium and contained in a cartridge filter attached to the stirrer rod. Finally STAGs were purified and obtained with yields of over 80 mol STAGs/100 mol STAGs in the reaction product (no FFAs were detected).     

Provably-Secure Time-Bound Hierarchical Key Assignment Schemes

A time-bound hierarchical key assignment scheme is a method to assign time-dependent encryption keys to a set of classes in a partially ordered hierarchy, in such a way that each class can compute the keys of all classes lower down in the hierarchy, according to temporal constraints.     

Analysis of in situ monitored thermal cycling benefits for wireless packaging early reliability evaluation

With the increasing complexity of the power amplifier (PA) module architecture, the probability of a thermally induced stress related failure mechanism increases. To help evaluate the increase in module complexity, a more sophisticated in situ monitored thermal cycle reliability test is available. The module is monitored in real time using a resistance daisy chain methodology designed to provide coverage using resistance feedback throughout the entire hierarchy of the module and carrier board interface. Monitored temperature cycling allows for real time failure feedback and enhanced failure signature information. Further, the testing technique has proven to be a valuable method for capturing the early stages of a module mechanical failure at the temperature extremes. Moreover, statistical evaluation of the failure data (Weibull analysis) is improved and better accuracy of the failures in time (FIT) rate can be determined.     

Ranking of departments and researchers within a university using two different databases: Web of Science versus Scopus

In this work, we compare the difference in the number of citations compiled with Scopus as opposed to the Web of Science (WoS) with the aim of analysing the agreement among the citation rankings generated by these databases. For this, we analysed the area of Health Sciences of the University of Navarra (Spain), composed of a total of 50 departments and 864 researchers. The total number of published works reflected in the WoS during the period 1999–2005 was 2299. For each work, the number of citations in both databases was recorded. The results indicate that the works received 14.7% more citations in Scopus than in WoS. In the departments, the difference was greater in the clinical ones than in the basic ones. In the case of the rankings of citations, it was found that both databases generate similar results. The Spearman and Kendall-Tau coefficients were higher than 0.9. It was concluded that the difference in the number of citations found did not correspond to the difference of coverage of WoS and Scopus.     

Brain fMRI reactivity to smoking-related images before and during extended smoking abstinence.

[Correction Notice: An erratum for this article was reported in Vol 18(3) of Experimental and Clinical Psychopharmacology (see record 2010-11933-011). In the article the authors find it necessary to redefine the thresholding procedure used for data analyses, due to problems in the Brain Voyager software. This does not affect the main findings of the paper.] Reactivity to smoking-related cues may play a role in the maintenance of smoking behavior and may change depending on smoking status. Whether smoking cue-related functional MRI (fMRI) reactivity differs between active smoking and extended smoking abstinence states currently is unknown. We used fMRI to measure brain reactivity in response to smoking-related versus neutral images in 13 tobacco-dependent subjects before a smoking cessation attempt and again during extended smoking abstinence (52 ± 11 days) aided by nicotine replacement therapy. Prequit smoking cue induced fMRI activity patterns paralleled those reported in prior smoking cue reactivity fMRI studies. Greater fMRI activity was detected during extended smoking abstinence than during the prequit assessment subcortically in the caudate nucleus and cortically in prefrontal (BA 6, 9, 44, 46), primary somatosensory (BA 1, 2, 3), temporal (BA 22, 41, 42), parietal (BA 7, 40) anterior cingulate (BA 24, 32), and posterior cingulate (BA 31) cortex. These data suggest that during extended smoking abstinence, fMRI reactivity to smoking versus neutral stimuli persists in brain areas involved in attention, somatosensory processing, motor planning, and conditioned cue responding. In some brain regions, fMRI smoking cue reactivity is increased during extended smoking abstinence in comparison to the prequit state, which may contribute to persisting relapse vulnerability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)