A Novel Connectionist System for Unconstrained Handwriting Recognition

Recognizing lines of unconstrained handwritten text is a challenging task. The difficulty of segmenting cursive or overlapping characters, combined with the need to exploit surrounding context, has led to low recognition rates for even the best current recognizers. Most recent progress in the field has been made either through improved preprocessing or through advances in language modeling. Relatively little work has been done on the basic recognition algorithms. Indeed, most systems rely on the same hidden Markov models that have been used for decades in speech and handwriting recognition, despite their well-known shortcomings. This paper proposes an alternative approach based on a novel type of recurrent neural network, specifically designed for sequence labeling tasks where the data is hard to segment and contains long-range bidirectional interdependencies. In experiments on two large unconstrained handwriting databases, our approach achieves word recognition accuracies of 79.7 percent on online data and 74.1 percent on offline data, significantly outperforming a state-of-the-art HMM-based system. In addition, we demonstrate the network's robustness to lexicon size, measure the individual influence of its hidden layers, and analyze its use of context. Last, we provide an in-depth discussion of the differences between the network and HMMs, suggesting reasons for the network's superior performance.     

Multi-model reliability-based design optimization of structures considering the intact configuration and several partial collapses

Some structures require keeping a specific safety level even if part of their elements have collapsed. The aim of this paper is to obtain the optimum design of these structures when uncertainty in some parameters that affects to the structural response is also considered. A Reliability-Based Design Optimization (RBDO) problem is formulated in order to minimize the mass of the structure fulfilling probabilistic constraints in both intact and damaged configurations. The proposed methodology combines the formulation of multi-model optimization with RBDO techniques programmed in a Matlab code. Two application examples are presented consisting of a two-dimensional truss structure with stress constraints as well as a curved stiffened panel of an aircraft fuselage subjected to buckling constraints.     

A path-relinking approach for a bi-criteria disassembly sequencing problem

The first crucial step of product recovery is disassembly. Some product disassembly is almost always needed in remanufacturing, recycling, and disposal. Since disassembly tends to be expensive, disassembly sequence planning becomes important in minimizing resources (time and money) invested in disassembly and maximizing the level of automation. A disassembly sequence plan (DSP) is a sequence of disassembly tasks, which begins with a product to be disassembled and terminates in a state where all of the parts of interest are separated. The decision version of the problem of finding the optimal DSP is an NP-complete problem and therefore complex and challenging to solve. Often one has to resort to heuristic and metaheuristic techniques for solving such problems. In this paper, we seek a DSP that addresses two criteria in order. First, we look for a sequence, the cost of which is close to our cost aspiration. Second, we look for a sequence that prioritizes some selected parts to be disassembled as early as possible. We propose a greedy randomized adaptive search procedure (GRASP) and path-relinking-based heuristic methodology specifically developed to solve such bi-criteria type of disassembly problem. An example is considered to illustrate the implementation of the methodology. Conclusions drawn include the consistent generation of near-optimal solutions, the ability to preserve precedence, the superior speed of the metaheuristic, and its practicality due to its ease of implementation.     

Guidelines for the development of e-learning systems by means of proactive questions

The current development approaches for e-learning systems fail to explain in a clear and consistent way the pedagogical principles that support them. Moreover, decisions with regard to the structuration of each component proposed by these approaches are mainly taken by the designer/developer. As a result, the ensuing e-learning systems reflect “common sense” rather than a theoretically informed and systematic design.The present paper proposes a global architecture model for any e-learning system whose blocks are extracted from the analysis of the main approaches that currently guide the development of these kinds of systems. We use Kipling’s famous questions to define and structure the blocks of the proposed model, and we base the answers to these questions on two disciplines that are closed to e-learning: presential education (i.e., its pedagogical theories) and knowledge management.     

On the design of a high-performance adaptive router for CC-NUMA multiprocessors

This work presents the design and evaluation of an adaptive packet router aimed at supporting CC-NUMA traffic. We exploit a simple and efficient packet injection mechanism to avoid deadlock, which leads to a fully, adaptive routing by employing only three virtual channels. In addition, we selectively use output buffers for implementing the most utilized virtual paths in order to reduce head-of-line blocking. The careful implementation of these features has resulted in a good trade-off between the network performance and hardware cost. The outcome of this research is a high-performance adaptive router (HPAR), which adequately balances the needs of parallel applications: minimal network latency at low loads and high throughput at heavy loads. The paper includes an evaluation process in which HPAR is compared with other adaptive routers using FIFO input bufferring, with or without additional virtual channels to reduce head-of-line blocking. This evaluation contemplates both the VLSI costs of each router and their performance under synthetic and real application workloads. To make the comparison fair, all the routers use the same efficient deadlock avoidance mechanism. In all the experiments, HPAR exhibited the best response among all the routers tested. Moreover, the observed packet latencies were comparable to those exhibited by simpler routers. Therefore, HPAR can be considered as a suitable candidate to implement packet interchange in next generations of CC-NUMA multiprocessors.     

Flexible system for simulating and tele‐operating robots through the internet

Simulation and teleoperation tools offer many advantages for the training or learning of technological subjects, such as flexibility in time‐tables and student access to expensive and limited equipment. In this paper, we present a new system for simulating and tele‐operating robot arms through the Internet, which allows many users to simulate and test positioning commands for a robot by means of a virtual environment, as well as execute the validated commands in a real remote robot of the same characteristics. The main feature of the system is its flexibility in managing different robots or including new robot models and equipment. © 2005 Wiley Periodicals, Inc.     

Combined Ligand‐ and Receptor‐Based Virtual Screening Methodology to Identify Structurally Diverse Protein Tyrosine Phosphatase 1B Inhibitors

Protein tyrosine phosphatase 1B (PTP1B) is a potential drug target for diabetes and obesity. However, the design of PTP1B inhibitors that combine potency and bioavailability is a great challenge, and new leads are needed to circumvent this problem. Virtual screening (VS) workflows can be used to find new PTP1B inhibitors with little chemical similarity to existing inhibitors. Unfortunately, previous VS workflows for the identification of PTP1B inhibitors have several limitations, such as a small number of experimentally tested compounds and the low bioactivity of those compounds. We developed a VS workflow capable of identifying 15 structurally diverse PTP1B inhibitors from 20 compounds, the bioactivity of which was tested in vitro. Moreover, we identified two PTP1B inhibitors with the highest bioactivity reported by any VS campaign (i.e., IC₅₀ values of 1.4 and 2.1 μm ), which could be used as new lead compounds.     

Dispersion and exfoliation of nanoclays in itaconic acid funcionalized LDPE by ultrasound treatment

Polyethylene–montmorillonite nanocomposites were prepared in the melt applying various ultrasonic powers (231, 347, and 462 W) and temperatures (185, 200, and 215 °C) in the presence of itaconic acid. Dispersion–exfoliation of montmorillonite and in situ low density polyethylene functionalization with itaconic acid were carried out by ultrasound assisted extrusion process. Clay dispersion and exfoliation was evaluated by X‐ray diffraction (XRD) and electronic microscopy (STEM). The degree of grafting itaconic acid into low density polyethylene (LDPE) was determined by infrared analysis (FTIR) and titration technics. Ultrasound‐treated nanocomposites showed improved clay dispersion compared with non‐treated ones. Mechanical properties, XRD, and STEM microscopy indicated that the grafting level, clay dispersion, and exfoliation was directly influenced by IA concentration, temperature, and ultrasonic energy. For instance, the itaconic acid grafted into LDPE was improved from 0.13% to 0.71% when ultrasound power was increased and when temperature was reduced. The modulus was enhanced up to 225 MPa when the ultrasound power was increased up to 462 W. The nanocomposites decomposition temperature, determined by thermogravimetric analysis, was increased nearly 20 °C when 1% w/w itaconic acid was used. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46260.     

Synthesis,structural characterization,and photocatalytic activity of Bi‐based nanoparticles

Bi‐based nanoparticles were successfully synthesized (500°C/2 h) following two intermediate‐temperature routes, Pechini and a combined method of mechanical milling/molten salts. Herein, α‐Bi₂O₃/Bi₂O₂CO₃ heterostructures were identified. These types of heterostructures have shown advantages to improve the visible light responsive activity of Bi‐based nanoparticles to facilitate the separation of photogenerated electron‐hole pairs. By fixing the experimental parameters, the synthesis route and Ag contents showed to play a very important role in the phase composition of the Ag‐containing samples; the formation of Bi/Ag‐Bi₂O₃/Bi₂O₂CO₃ and Ag/Ag‐Bi₂O₃/Bi₂O₂CO₃ complex hybrid structures were revealed. The α‐Bi₂O₃/Bi₂O₂CO₃ heterostructure prepared by combined method exhibited higher photocatalytic efficiency (66.84%) for degrading methylene blue (MB) depending on Bi₂O₂CO₃ component proportion. For the Ag‐containing hybrid structures, the performance of their catalytic activity did not show an increase with respect to α‐Bi₂O₃/Bi₂O₂CO₃. However, in these samples, the degradation efficiency was slightly enhanced with the efficient doping of Ag into the α‐Bi₂O₃ structure and the existence of Bi when the Pechini method was used. Also, a possible photocatalytic process for degrading MB is presented.     

13C nuclear magnetic resonance monitoring of free fatty acid release after fish thermal processing

¹³C Nuclear magnetic resonance spectroscopy was applied to the study of lipid hydrolysis occurring during industrial canning of tuna (Thunnus alalunga). An increase in the free fatty acid (FFA) level was observed after cooking and sterilization, and a different FFA pattern was found when storage of the frozen raw material and thermal steps (cooking and can sterilization) were compared. Lipolysis in raw muscle occurs preferentially in thesn-1 andsn-3 acyl positions of triacylglycerols, with a consequent cleavage of saturated and monounsaturated fatty acids. After thermal processing, an increase of docosahexaenoic acid (DHA) was found in the FFA fraction, as well as a relative decrease of the peak intensity of DHA in thesn-2 position of triacylglycerols. This finding indicates a different mechanism of FFA release during the frozen storage and thermal processing of raw fish.