A feature-based reverse engineering system using artificial neural networks

Reverse Engineering (RE) is the process of reconstructing CAD models from scanned data of a physical part acquired using 3D scanners. RE has attracted a great deal of research interest over the last decade. However, a review of the literature reveals that most research work have focused on creation of free form surfaces from point cloud data. Representing geometry in terms of surface patches is adequate to represent positional information, but can not capture any of the higher level structure of the part. Reconstructing solid models is of importance since the resulting solid models can be directly imported into commercial solid modellers for various manufacturing activities such as process planning, integral property computation, assembly analysis, and other applications. This research discusses the novel methodology of extracting geometric features directly from a data set of 3D scanned points, which utilises the concepts of artificial neural networks (ANNs). In order to design and develop a generic feature-based RE system for prismatic parts, the following five main tasks were investigated. (1) point data processing algorithms; (2) edge detection strategies; (3) a feature recogniser using ANNs; (4) a feature extraction module; (5) a CAD model exchanger into other CAD/CAM systems via IGES. A key feature of this research is the incorporation of ANN in feature recognition. The use of ANN approach has enabled the development of a flexible feature-based RE methodology that can be trained to deal with new features. ANNs require parallel input patterns. In this research, four geometric attributes extracted from a point set are input to the ANN module for feature recognition: chain codes, convex/concave, circular/rectangular and open/closed attribute. Recognising each feature requires the determination of these attributes. New and robust algorithms are developed for determining these attributes for each of the features. This feature-based approach currently focuses on solving the feature recognition problem based on 2.5D shapes such as block pocket, step, slot, hole, and boss, which are common and crucial in mechanical engineering products. This approach is validated using a set of industrial components. The test results show that the strategy for recognising features is reliable

Arginyltransferase, Its Specificity, Putative Substrates, Bidirectional Promoter, and Splicing-derived Isoforms

Substrates of the N-end rule pathway include proteins with destabilizing N-terminal residues. Three of them, Asp, Glu, and (oxidized) Cys, function through their conjugation to Arg, one of destabilizing N-terminal residues that are recognized directly by the pathway's ubiquitin ligases. The conjugation of Arg is mediated by arginyltransferase, encoded by ATE1. Through its regulated degradation of specific proteins, the arginylation branch of the N-end rule pathway mediates, in particular, the cardiovascular development, the fidelity of chromosome segregation, and the control of signaling by nitric oxide. We show that mouse ATE1 specifies at least six mRNA isoforms, which are produced through alternative splicing, encode enzymatically active arginyltransferases, and are expressed at varying levels in mouse tissues. We also show that the ATE1 promoter is bidirectional, mediating the expression of both ATE1 and an oppositely oriented, previously uncharacterized gene. In addition, we identified GRP78 (glucose-regulated protein 78) and protein-disulfide isomerase as putative physiological substrates of arginyltransferase. Purified isoforms of arginyltransferase that contain the alternative first exons differentially arginylate these proteins in extract from ATE1-/- embryos, suggesting that specific isoforms may have distinct functions. Although the N-end rule pathway is apparently confined to the cytosol and the nucleus, and although GRP78 and protein-disulfide isomerase are located largely in the endoplasmic reticulum, recent evidence suggests that these proteins are also present in the cytosol and other compartments in vivo, where they may become N-end rule substrates

Active site phosphoryl groups in the biphosphorylated phosphotransferase complex reveal dynamics in a millisecond time scale

AbstractThe N-terminal domain of Enzyme I (EIN) and phosphocarrier HPr can form a biphosphorylated complex when they are both phosphorylated by excess cellular phosphoenolpyruvate. Here we show that the electrostatic repulsion between the phosphoryl groups in the biphosphorylated complex results in characteristic dynamics at the active site in a millisecond time scale. The dynamics is localized to phospho-His15 and the stabilizing backbone amide groups of HPr, and does not impact on the phospho-His189 of EIN. The dynamics occurs with the kex of ∼500s−1 which compares to the phosphoryl transfer rate of ∼850s−1 between EIN and HPr. The conformational dynamics in HPr may be important for its phosphotransfer reactions with multiple partner proteins.Structured summary of protein interactionsEIN and HPr bind by nuclear magnetic resonance (View Interaction)

Acupuncture for the treatment of tinnitus: a systematic review of randomized clinical trials

BACKGROUND: Complementary and alternative medicine (CAM) has frequently been used to treat tinnitus, and acupuncture is a particularly popular option. The objective of this review was to assess the evidence concerning the effectiveness of acupuncture as a treatment for tinnitus. METHODS: Fourteen databases were searched from the dates of their creation to July 4th, 2012. Randomized clinical trials (RCTs) were included if acupuncture was used as the sole treatment. The Cochrane risk of bias tool was used to assess the risk of bias. RESULTS: A total of 9 RCTs met all the inclusion criteria. Their methodological quality was mostly poor. Five RCTs compared the effectiveness of acupuncture or electroacupuncture with sham acupuncture for treating tinnitus. The results failed to show statistically significant improvements. Two RCTs compared a short one-time scalp acupuncture treatment with the use of penetrating sham acupuncture at non-acupoints in achieving subjective symptom relief on a visual analog scale; these RCTs demonstrated significant positive effects with scalp acupuncture. Two RCTs compared acupuncture with conventional drug treatments. One of these RCTs demonstrated that acupuncture had statistically significant effects on the response rate in patients with nervous tinnitus, but the other RCT did not demonstrate significant effects in patients with senile tinnitus. CONCLUSIONS: The number, size and quality of the RCTs on the effectiveness of acupuncture for the treatment of tinnitus are not sufficient for drawing definitive conclusions. Further rigorous RCTs that overcome the many limitations of the current evidence are warranted

Tempcore Process Simulator to Analyze Microstructural Evolution of Quenched and Tempered Rebar

Featured Application Proposed process simulator can be widely applied to parameter design of industrial Tempcore process with reduced cost and time. Abstract Tempcore process simulator (TPS) has been developed in this study to analyze the microstructural evolution of quenched and tempered rebar. There has been an increasing need to relate the complex microstructures to the resulting properties of quenched and tempered rebar. However, information on such relationships typically requires precise thermal histories imposed on the workpiece. Therefore, TPS, capable of simulating the Tempcore process, has been developed to produce high-fidelity data. TPS mainly consists of a vacuum induction furnace, pilot rolling mill, box furnace, and cooling unit to simulate shop floor operations. A series of experimental tests were successfully carried out with various parameters, such as reheating temperature, water flow, water pressure, and cooling time. The effects of chemical compositions and cooling time on the microstructural evolution and mechanical properties of quenched and tempered rebar have been analyzed to validate the performance of TPS. The results show that TPS can simulate the Tempcore process with a high degree of fidelity and reliability.11Ysciescopu

Dysfunction in Configural Face Processing in Patients With Schizophrenia

Background: Face recognition has important implications for patients with schizophrenia, who exhibit poor interpersonal and social skills. Previous reports have suggested that patients with schizophrenia have deficits in their ability to recognize faces, and because face recognition relies heavily on information about the configuration of faces, we hypothesized that patients with schizophrenia would have specific problems in processing configural information. Methods: We measured the performance of 20 patients with schizophrenia and 20 normal subjects in a face-discrimination task, using upright and inverted pairs of face photographs that differed in featural or configural information. Results: The patients with schizophrenia showed disproportionately poorer performance in discriminating configural compared with featural face sets. Conclusion: The result suggests that the face-recognition deficit in schizophrenic patients is due to specific impairments in configural processing of faces

EFFECTS OF LIQUID SWIRLING ON GAS-TO-LIQUID MASS TRANSFER IN THREE-PHASE FLUIDIZED BEDS

The swirling flow mode of liquid phase was adopted to promote the gas-to-liquid mass transfer in three-phase(gas-liquid-solid) fluidized beds. Effects of gas(0.01-0.09m/s) and liquid(0.035-0.172m/s) velocities, particle size(1.7-6.0mm) and swirling ratio of liquid phase(0-0.5) on the volumetric gas-to-liquid mass transfer coefficient in the bed were examined. The mass transfer coefficient increased up to 70% by adjusting the swirling flow of liquid phase, especially when the gas velocity is relatively low range. The value of gas-to-liquid mass transfer coefficient was well correlated in terms of dimensionless groups which were derived from the dimensional analysis on the mass transfer system