A constructive heuristic algorithm for concurrently selecting and sequencing jobs in an FMS environment

This paper deals with the concurrent solution of the loading and scheduling problems in a flexible manufacturing system ( FMS) environment. It is assumed that the FMS environment has production planned periodically and each job in the system has a number of operations to be processed on flexible machines. A heuristic approach using a constructive scheduling method is developed to solve the FMS loading and scheduling problems concurrently. The computational results are compared to an existing procedure that considers a hierarchical approach with a similar problem environment. The comparison study shows a significant improvement over the existing hierarchical procedure. This experiment indicates that a concurrent solution approach can solve the FMS loading and scheduling problems very effectively.     

Continuous mobile robot localization by using structured light and a geometric map

A mobile robot needs to know its position and orientation with accuracy in order to decide the control actions that permit it to finish the entrusted tasks successfully. To obtain this information, dead-reckoning-based systems have been used, and more recently inertial navigation systems. However, these systems have some errors that grow bigger as time goes by, therefore a moment comes when the information provided is useless. Because of this, there should be a periodic process that updates the robot position and orientation of the vehicle. The process to determine the robot position and orientation by using information originated from the external sensors is defined as the mobile robot relocalization. It is obvious that the greater the frequency of this process, the better the knowledge of its position the robot will have, and therefore its movements will be better directed to the point it must reach. The algorithm to achieve this can be classified in two large groups: relocalization through an a priori map of the environment and relocalization through the detection of landmarks present in that environment. The algorithm presented in the paper belongs to the first case. The sensor used is a combination of a laser diode and a CCD camera. The sensorial information is modelled as straight lines that will be matched with an a priori map of the environment. With this, the position of the mobile robot is estimated. The matching process is accomplished within an extended Kalman filter. The algorithm is able to work in real time, and it actualizes the position of the robot in a continuous way.     

Technical note Seafloor characterization through side scan sonar image processing

This paper presents the most suitable image processing techniques being used at present for recognising features either lying on the seafloor or floating in the water column. The preprocessing methodology is already incorporated in the sonar system, and as we cannot access the raw data, it is not included in this paper. The studied images correspond to the Cabrera Archipelago, in the Mediterranean Sea.     

Probiotic buttermilk-like fermented milk product development in a semiindustrial scale: Physicochemical, microbiological and sensory acceptability

Probiotic buttermilk-like fermented milk in different flavors in versions with sucrose and sucralose were processed in a pilot plant. The Mesophilic Aromatic Culture CHN-22 and Bifidobacterium animalis Bb12 were the cultures employed for fermentation. Physicochemical composition, apparent viscosity, diacetyl content, viability of cultures during storage, and acceptance of product via sensorial analysis were assessment factors. The high viability of the probiotic culture was observed (average 8.08 log cfu/ml) during refrigerated storage (28 days) of buttermilk and good acceptance of the product via sensory test. However, the probiotic culture might have been responsible for the loss of diacetyl, a volatile compound that is a characteristic feature of the product.     

Osmotic Dehydration and Vacuum Impregnation on Physicochemical Properties of Chilean Papaya (Carica candamarcensis)

ABSTRACT: The effect of osmotic dehydration (OD) at atmospheric pressure and vacuum impregnation (VI) treatments on some physiochemical parameters of papaya (aw, pH, color, firmness, and microstructure) was analyzed. Osmotic treatments were carried out on papaya with 55°Brix and 65°Brix sucrose solutions at 30 °C. VI with 65°Brix osmotic solution was the most effective in reducing aw due to the highest sucrose gain during osmotic treatment. Color differences were associated to loss of clarity in line with transparency gain. Scanning electron microscopy observations show that osmotic dehydration caused shape changes and size reduction of papaya cells; also differences in microstructural features were observed between OD-treated and VI-treated samples. Moreover, the largest firmness observed in VI samples compared with OD treatments was associated with the thickness of the middle lamella between cells, which was greater in VI than OD treatments. Improvement in texture and palatability of papaya was obtained with VI rather than OD treatment compared with fresh papaya.     

Influence of manufacturing conditions and discrimination of Northern Spanish cheeses using multi‐element analysis

Thirty‐three samples of cheeses belonging to different Protected Designation of Origin (PDOs) located in Northern Spain were analysed with the aim of studying the influence of processing conditions on the minerals and trace elements content in cheeses. The use of sheep milk, animal rennet, salting by immersion in a brine bath and ripening in cheeses reported, in general, the highest levels of trace elements. Moreover, pattern recognition analysis of multi‐elemental data, based on mineral and trace element content, was used to determine geographical traceability and to detect possible imitations with a correct classification in 98.5% of cases.     

On the verification of polynomial system solvers

We discuss the verification of mathematical software solving polynomial systems symbolically by way of triangular decomposition. Standard verification techniques are highly resource consuming and apply only to polynomial systems which are easy to solve. We exhibit a new approach which manipulates constructible sets represented by regular systems. We provide comparative benchmarks of different verification procedures applied to four solvers on a large set of well-known polynomial systems. Our experimental results illustrate the high efficiency of our new approach. In particular, we are able to verify triangular decompositions of polynomial systems which are not easy to solve.