1,384 research outputs found

    A Weight-coded Evolutionary Algorithm for the Multidimensional Knapsack Problem

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    A revised weight-coded evolutionary algorithm (RWCEA) is proposed for solving multidimensional knapsack problems. This RWCEA uses a new decoding method and incorporates a heuristic method in initialization. Computational results show that the RWCEA performs better than a weight-coded evolutionary algorithm proposed by Raidl (1999) and to some existing benchmarks, it can yield better results than the ones reported in the OR-library.Comment: Submitted to Applied Mathematics and Computation on April 8, 201

    An Image Morphing Technique Based on Optimal Mass Preserving Mapping

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    ©2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.DOI: 10.1109/TIP.2007.896637Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The 2 mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods

    New insights into the anti-inflammatory mechanisms of glucocorticoids : an emerging role for glucocorticoid-receptor-mediated transactivation

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    Glucocorticoids are anti-inflammatory drugs that are widely used for the treatment of numerous (autoimmune) inflammatory diseases. They exert their actions by binding to the glucocorticoid receptor (GR), a member of the nuclear receptor family of transcription factors. Upon ligand binding, the GR translocates to the nucleus, where it acts either as a homodimeric transcription factor that binds glucocorticoid response elements (GREs) in promoter regions of glucocorticoid (GC)-inducible genes, or as a monomeric protein that cooperates with other transcription factors to affect transcription. For decades, it has generally been believed that the undesirable side effects of GC therapy are induced by dimer-mediated transactivation, whereas its beneficial anti-inflammatory effects are mainly due to the monomer-mediated transrepressive actions of GR. Therefore, current research is focused on the development of dissociated compounds that exert only the GR monomer-dependent actions. However, many recent reports undermine this dogma by clearly showing that GR dimer-dependent transactivation is essential in the anti-inflammatory activities of GR. Many of these studies used GR(dim/dim) mutant mice, which show reduced GR dimerization and hence cannot control inflammation in several disease models. Here, we review the importance of GR dimers in the anti-inflammatory actions of GCs/GR, and hence we question the central dogma. We summarize the contribution of various GR dimer-inducible anti-inflammatory genes and question the use of selective GR agonists as therapeutic agents

    ON THE DEVELOPMENT OF HIGH-PERFORMANCE DRILLING TOOLS BY MEANS OF CAD/CAM AND ANALYSIS OF CHIP FORMATION MECHANISM

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    Dokument pojednává o návrhu vrtacích nástrojů za pomocí CAD a CAE technologií. Nejprve jsou stručně nastíněny různé postupy tvorby 3D modelů vrtacích nástrojů, zmíněny možnosti měření jejich silového zatížení při vrtání, je uveden popis mechanismu tvorby třísky a následně je prezentován přehled nejpoužívanějších explicitních (síťových) metod konečných prvků využívaných pro simulace obrábění. Pro tuto práci byla vybrána bezsíťová metoda SPH, která i přes to, že je schopna velmi dobře zvládat velké deformace a přetvoření materiálu, není pro simulace obrábění téměř využívána a v dostupných publikacích lze nalézt pouze informace týkající se simulací ortogonálního obrábění. Demonstrována je na příkladu simulace ortogonálního obrábění hliníkové slitiny A2024-T351, která zároveň slouží jako výchozí bod pro simulace vrtání pomocí metody SPH. Následuje popis návrhu, simulací a testování prototypů nových vrtacích nástrojů - tříbřitých a dvoubřitých vrtáků s vnitřním odvodem třísky, přičemž podrobněji se dokument zaměřuje na dvoubřitou variantu s monolitní vrtací hlavicí. Pro tento typ nástroje byla provedena i SPH simulace vrtání, která odhalila některé nevýhody dané metody spojené s požadavkem na přesnější simulaci tvaru třísky, a to sice prudký nárůst počtu SPH elementů a následné, v některých případech zásadní prodloužení výpočtového času. Podklady týkající se dvoubřitých vrtacích nástrojů byly poté využity pro tvorbu přihlášky vynálezu.This document deals with the development of drilling tools by means of CAD and CAE technologies. At first, a brief overview of various design procedures of 3D drill models is presented, possibilities of measurement of force and moment loading during drilling are mentioned, a chip formation mechanism is briefly described and then a list of commonly used explicit (mesh) finite element methods used for cutting simulations is presented. A meshless SPH method have been selected for this work. Although it is able to handle the large deformations easily, it has been used for cutting simulations very rarely and only an orthogonal cutting simulations related information can be found in scientific databases. It has been demonstrated on the orthogonal cutting simulation of A2024-T351 alloy that was also the starting point for SPH simulation of drilling. The following is a decription of the design, simulation and prototyping of new drilling tools - drills with three and two cutting edges and an internal chip channel. This document is focused in detail on the variant with two cutting edges for which SPH drilling simulation has also been performed. Some drawbacks related to more precise chip simulation demands have been revealed, especially a rapid increase in number of SPH elements followed with prolongation of a computational time. Information related to the design of the drilling head with two cutting edges were then used to create the patent application.

    Kiss goodbye to the ‘kissing knees’: no association between frontal plane inward knee motion and risk of future non-contact ACL injury in elite female athletes

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    The aim of this study was to investigate if frontal plane knee and hip control in single-leg squats or vertical drop jumps with an overhead target were associated with future non-contact anterior cruciate ligament (ACL) injury in elite female athletes. Of the 429 handball and 451 football athletes (age 21.5 ± 4.0 years, height 169.6 ± 6.4 cm, body weight 67.1 ± 8.0 kg), 722 non-injured and 56 non-contact ACL injured participants were eligible for analysis. We calculated lateral pelvic tilt, frontal plane knee projection angle, medial knee position, and side-to-side asymmetry in these from 2D videos recorded at baseline, and recorded any new ACL injuries prospectively. None of the aforementioned variables in either screening task were different or could discriminate between injured and non-injured athletes (all p values \u3e .05 and Cohen’s d values \u3c .27). Two-dimensional video assessment of frontal plane knee and hip control during both a single-leg squat and vertical drop jump was unable to identify individuals at increased risk of non-contact ACL injury, thus should not be used for screening

    Numerické řešení procesu rozpojování tvrdých hornin. Část 2

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    This paper focuses on a numerical analysis of a hard rock (ore) disintegration process. A bit moves into the ore and subsequently disintegrates it. The disintegration (i.e. fracture of ore) is solved via a deterministic approach (FEM) and a probabilistic approach (FEM in combination with the SBRA - Simulation-Based Reliability Assessment method, i.e. Monte Carlo simulations, stochastic inputs). The ore is disintegrated by deactivating the finite elements satisfying fracture conditions. The results are compared with experiments. The application of the SBRA method is a new and innovative trend in this area. Finally, the probabilistic reliability assessment is mentioned.Článek se zaměřuje na numerickou analýzu procesu rozpojování tvrdých hornin (rud). Nůž se pohybuje do horniny a následně ji rozpojuje. Rozpojování (tj. lom rudy) je řešeno deterministickým přístupem (MKP) a pravděpodobnostním přístupem (MKP v kombinaci s metodou SBRA - Simulation-Based Reliability Assessment, tj. simulace Monte Carlo, stochastické vstupy). Ruda je rozpojována pomocí deaktivace konečných prvků, které splňují podmínky odlomení. Výsledky jsou porovnány s experimenty. Aplikace metody SBRA v této oblasti je novým a inovativním trendem. V závěru je uveden pravděpodobnostní posudek spolehlivosti

    Glucocorticoids synergize with IL-1β to induce TLR2 expression via MAP Kinase Phosphatase-1-dependent dual Inhibition of MAPK JNK and p38 in epithelial cells

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    BACKGROUND: Despite the importance of glucocorticoids in suppressing immune and inflammatory responses, their role in enhancing host immune and defense response against invading bacteria is poorly understood. Toll-like receptor 2 (TLR2) has recently gained importance as one of the major host defense receptors. The increased expression of TLR2 in response to bacteria-induced cytokines has been thought to be crucial for the accelerated immune response and resensitization of epithelial cells to invading pathogens. RESULTS: We show that IL-1β, a key proinflammatory cytokine, greatly up-regulates TLR2 expression in human epithelial cells via a positive IKKβ-IκBα-dependent NF-κB pathway and negative MEKK1-MKK4/7-JNK1/2 and MKK3/6-p38 α/β pathways. Glucocorticoids synergistically enhance IL-1β-induced TLR2 expression via specific up-regulation of the MAP kinase phosphatase-1 that, in turn, leads to dephosphorylation and inactivation of both MAPK JNK and p38, the negative regulators for TLR2 induction. CONCLUSION: These results indicate that glucocorticoids not only suppress immune and inflammatory response, but also enhance the expression of the host defense receptor, TLR2. Thus, our studies may bring new insights into the novel role of glucocorticoids in orchestrating and optimizing host immune and defense responses during bacterial infections and enhance our understanding of the signaling mechanisms underlying the glucocorticoid-mediated attenuation of MAPK
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