A benchmark for OCL engine accuracy, determinateness, and efficiency

Since several years, the Object Constraint Language (OCL) is a central component in modeling and transformation languages like the Unified Modeling Language, the Meta Object Facility, and Query View Transformation. Consequently, approaches MDE (Model-Driven Engineering) depend on this language. OCL is present not only in areas influenced by the OMG but also in the Eclipse Modeling Framework (EMF). Thus the quality of OCL and its realization in tools seems to be crucial for the success of model-driven development. Surprisingly, up to now a benchmark for OCL to measure quality properties has not been proposed. This paper puts forward in the first part the concepts of a comprehensive OCL benchmark. Our benchmark covers (1) OCL engine accuracy (e.g., for the handling of the undefined value, the use of variables and the implementation of OCL standard operations), (2) OCL engine determinateness properties (e.g., for the collection operations ??any?? and ??flatten??), and (3) OCL engine efficiency (for data type and user-defined operations). In the second part, this paper empirically evaluates the proposed benchmark concepts by examining several OCL tools. The paper clarifies a number of differences in handling particular language features and under specifications in the OCL standard.     

Fibre optic probe measurements in landrace pigs of different halothane phenotypes

Fibre Optic Probe (FOP) measurements were made in the longissimus dorsi muscle of 70 halothane-positive (HP) and 70 halothane negative (HN) pigs of a synthetic Landrace strain at 45 min (FOP(1)), 3 h (FOP(3)) and 17h (FOP(17)) post mortem. Measurements of pH, rigor and temperature were also made in the slaughterline. Carcasses were sampled (longissimus dorsi, 2-4 lumbar vertebrae) at 18h post mortem and meat quality objectively assessed. The incidence of slight PSE (visual score) was 49% in HP and 10% in HN pigs, while the incidence of serious PSE was 20% and 4%, respectively. Yet, the percentage drip loss during 48 h storage in HN/PSE pigs was higher than in HP/PSE pigs (10·2 vs 7·5%), which was associated with a lower ultimate pH (5·25 vs 5·44). Therefore, it is suggested that the remaining PSE problem in HN Landrace pigs, although less in frequency, might be more serious. In the whole population, of all FOP measurements taken correlations with colour (Hunter L(?)-value) and percentage drip loss were highest for the FOP(17) measurements (r = 0·82 and 0·69, respectively). FOP(1) was better related than pH(1) to colour, while the relationships with drip loss were of a similar magnitude. Differences in FOP values between HP and HN pigs were larger for FOP(1) (148 vs 108) than for FOP(3) (148 vs 125) or FOP(17) (153 vs 130). The relationship between FOP1 and ultimate meat colour (L(?)-value) appeared to be higher in HP (0·60) than in HN (0·48) pigs, while for the relationship between FOP(1) and percentage drip loss the reverse was true (0·48 and 0·60, respectively). The effect of halothane phenotype on the relationships found, may partially explain the different results of reflectance measurements reported in the literature as to their predictive value for ultimate meat quality. The results suggest that the measurement of reflectance in the slaughterline offers opportunities for identifying (potential) PSE carcasses. The large genetic influence of halothane phenotype on this parameter, may eventually justify its use as a base for payment for meat quality to the producer.     

Analysing and evaluating multi-actor multi-goal systems in use: social contexts and participation in three Vocational Guidance Systems (VGS)

The contexts of real use of information technology (IT) tools may be highly specific. Their distinctive features, especially normative and informational influences related to the social roles involved, can affect deeply both design and actual use of the artefact. Analysis and evaluation of the ongoing human-artefact interaction, particularly in systems addressed to multi-actor multi-goal environments like Vocational Guidance Systems (VGS), should thus be viewed as basically context-dependent. Studying three types of VGS (currently developed and running in public and private vocational agencies in Northern Italy), we constructed a taxonomy connecting types of systems and types of social environments, in order to explain differences between systems in design, communication and outcome. To assess the characteristics of the different types of VGS as dialogue tools, we considered their Social Design Structure (SDS) and Operating Social Structure (OSS), connecting steps and distance in each user-artefact interaction to the flow of the communication processes between designers, VG officers, and final users.     

The preparation of porous perovskite membranes using BaTiO3 nanopowders

The aim of this study was to develop a simple and reliable procedure in order to prepare composite membranes through the deposition of thin porous layers of perovskite-like oxides onto ceramic porous supports. BaTiO₃ nanopowders with controlled properties were obtained by Low Temperature Aqueous Synthesis (LTAS) and used as starting materials for the thin film deposition. Process parameters were determined in order to obtain a stable suspension of the nanopowder. The nanopowder was then effectively used to realize the layers with controlled properties. The results of characterisation tests indicated that the porosity of the deposited layers was of a mesoporous type and that the starting nanopowder did not undergo structural changes after the deposition process.     

A multi-matcher for ear authentication

In this work we propose a local approach of 2D ear authentication. A multi-matcher system is proposed where each matcher is trained using features extracted from a single sub-window of the whole 2D image. The features are extracted by the convolution of each sub-window with a bank of Gabor Filters, then their dimensionality is reduced by Laplacian EigenMaps. The best matchers, corresponding to the most discriminative sub-windows, are selected by running the Sequential Forward Floating Selection (SFFS). Our experiments, carried out on a database of 114 people, show that combining only few (ten) sub-windows in the fusion step it is possible to achieve a very low Equal Error Rate.     

Real-time volume rendering of MRCP: clinical applications

MR-cholangiopancreatography (Signa Contour 0.5T; GE/Medical Systems, Milwaukee, WI) data sets of 156 patients, obtained with a 2D T2-weighted FSE sequence, in the coronal plane, were volume rendered (Advantage Windows 3.1; GEMS) independently by two radiologists, that were asked to define the range of signal intensitics in which the signal of the pancreaticobiliary system was included and to rank the quality of native images and volume renderings. Patients had biliary stones (n=47), inflammatory ampullary stenoses (n=18), pancreaic tumors (n=12), surgical bilio-enteric anastomoses (n=19), ampullary carcinomas (n=2), pancreatic duct stone (n=1), cholangiocarcinoma (n=3) and normal pancreaticobiliary tree (n=54). Good quality volume renderings of the bile ducts were obtained for at least a maximum diameter of 1.5 mm. The quality rank agreement between volume rendering and native images was excellent (k=0.94). The correlation between the observers for the setting the signal intensity range was excellent and statistically significant (p<0.001). The correlation between the observers for the time of volume rendering was not statistically significant. Bilary stones could be displayed in 32/47 (68%) cases. The pancreatic duct stones was displayed as well. Inflammatory ampullary stenoses were detected in all cases (100%). In case of pancreatic tumors, cholangiocarcinomas and ampullary carcinomas volume rendering allowed to identify the site of stenosis. In surgical bilio-enteric anastomoses volume rendering was helpful to display the residual bilary tract, the site of anastomosis and the enteric tract. Volume rendering could be a reliable and efficient tool for the study of the anatomy and pathological changes of the pancreaticobiliary tract. Note: keywords have been selected from the Index to imaging literature (January 1999), of the RSNA (Supplement to Radiology).     

Patient-oriented interventions to improve communication in a medical office visit.

Examined an intervention to improve the patient's contribution to communication in a medical office visit. In Study 1, 53 women awaiting a medical appointment were assigned either to a group that was asked to list 3 questions to ask their physician or to a control group. Ss who listed questions asked more questions in the visit and reported being less anxious. In Study 2, with 49 women, a 3rd group received a message from their physician encouraging question asking. Both experimental groups asked more of the questions they had wished to, had greater feelings of control, and were more satisfied with the visit and with the information they received. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flexural Fatigue Behavior of Reinforced Concrete Beams Strengthened with FRP Fabric and Precured Laminate Systems

Rehabilitation of existing structures with carbon fiber reinforced polymers (CFRP) has been growing in popularity because they offer resistance to corrosion and a high stiffness-to-weight ratio. This paper presents the flexural strengthening of seven reinforced concrete (RC) beams with two FRP systems. Two beams were maintained as unstrengthened control samples. Three of the RC beams were strengthened with CFRP fabrics, whereas the remaining two were strengthened using FRP precured laminates. Glass fiber anchor spikes were applied in one of the CFRP fabric strengthened beams. One of the FRP precured laminate strengthened beams was bonded with epoxy adhesive and the other one was attached by using mechanical fasteners. Five of the beams were tested under fatigue loading for two million cycles. All of the beams survived fatigue testing. The results showed that use of anchor spikes in fabric strengthening increase ultimate strength, and mechanical fasteners can be an alternative to epoxy bonded precured laminate systems.     

Time-focused clustering of trajectories of moving objects

Spatio-temporal, geo-referenced datasets are growing rapidly, and will be more in the near future, due to both technological and social/commercial reasons. From the data mining viewpoint, spatio-temporal trajectory data introduce new dimensions and, correspondingly, novel issues in performing the analysis tasks. In this paper, we consider the clustering problem applied to the trajectory data domain. In particular, we propose an adaptation of a density-based clustering algorithm to trajectory data based on a simple notion of distance between trajectories. Then, a set of experiments on synthesized data is performed in order to test the algorithm and to compare it with other standard clustering approaches. Finally, a new approach to the trajectory clustering problem, called temporal focussing, is sketched, having the aim of exploiting the intrinsic semantics of the temporal dimension to improve the quality of trajectory clustering. The authors are members of the Pisa KDD Laboratory, a joint research initiative of ISTI-CNR and the University of Pisa: .