72 research outputs found

    An enhancement to the Bees Algorithm with slope angle computation and Hill Climbing Algorithm and its applications on scheduling and continuous-type optimisation problem

    Get PDF
    This paper focuses on improvements to the Bees Algorithm (BA) with slope angle computation and Hill Climbing Algorithm (SACHCA) during the local search process. First, the SAC was employed to determine the inclination of the current sites. Second, according to the slope angle, the HCA was utilised to guide the algorithm to converge to the local optima. This enabled the global optimum of the given problem to be found faster and more precisely by focusing on finding the available local optima first before turning the attention on the global optimum. The proposed enhancements to the BA have been tested on continuous-type benchmark functions and compared with other optimisation techniques. The results show that the proposed algorithm performed better than other algorithms on most of the benchmark functions. The enhanced BA performs better than the basic BA, in particular on higher dimensional and complex optimisation problems. Finally, the proposed algorithm has been used to solve the single machine scheduling problem and the results show that the proposed SAC and HCA-BA outperformed the basic BA in almost all the considered instances, in particular when the complexity of the problem increases

    Honey Bees Inspired Optimization Method: The Bees Algorithm

    Get PDF
    Optimization algorithms are search methods where the goal is to find an optimal solution to a problem, in order to satisfy one or more objective functions, possibly subject to a set of constraints. Studies of social animals and social insects have resulted in a number of computational models of swarm intelligence. Within these swarms their collective behavior is usually very complex. The collective behavior of a swarm of social organisms emerges from the behaviors of the individuals of that swarm. Researchers have developed computational optimization methods based on biology such as Genetic Algorithms, Particle Swarm Optimization, and Ant Colony. The aim of this paper is to describe an optimization algorithm called the Bees Algorithm, inspired from the natural foraging behavior of honey bees, to find the optimal solution. The algorithm performs both an exploitative neighborhood search combined with random explorative search. In this paper, after an explanation of the natural foraging behavior of honey bees, the basic Bees Algorithm and its improved versions are described and are implemented in order to optimize several benchmark functions, and the results are compared with those obtained with different optimization algorithms. The results show that the Bees Algorithm offering some advantage over other optimization methods according to the nature of the problem

    POUCHITIS: A TRIDIMENSIONAL VIEW

    Get PDF
    The preferred surgical treatment of ulcerative colitis (UC) and familial adenomatous polyposis (FAP) is represented by proctocolectomy with ileal pouch-anal anastomosis (IPAA). However, patients with UYC who have undergone IPAA are prone to develop several complications, which include surgery related/mecchanical complications; inflammatory or infectious disoreders; dysplasia or neoplasia; and systemic or metabolic disorders. Pouchitis, which is defined as the acute and/or chronic inflammation of the ileal reservoir, represent the most common long-term adverese sequela after IPAA. Gut microbiota play a pivotal role in the initiation and disease progression of pouchitis. Pouchitis can be classified according to the activity of the disease, the duration of the symptoms, the pattern of the disease or response to antibiotic therapy. Patients with IPAA for UC tend to experience a variety of symptoms that may eventually lead to pouch excision thereby necessitating the construction of a permanent ileostomy. To date, the ethiology, the diagnosis and the medical management of pouchitis represent a clinical challenge. In fact pouchitis range from a disease with an acute antibiotic-responsive presentation to a chronic antibiotic-refractory form, with subsequent different disease mechanism and clinical course. A tridimensional and multidisciplinar approach, including endoscopy, histology, and laboratory testing is widely helpful to identify the diferent phenotypes of the disease and to manage correctly its treatment

    Gonadectomia em gatas. Técnica cirúrgica

    Get PDF
    O artigo não apresenta resumo

    Catestatin, vasostatin, cortisol, temperature, heart rate, respiratory rate, scores of the short form of the Glasgow composite measure pain scale and visual analog scale for stress and pain behavior in dogs before and after ovariohysterectomy

    Get PDF
    Background: The stress reaction induced by surgery and associated pain may be detrimental for patient recovery and should be minimized. The neuropeptide chromogranin A (CGA) has shown promise as a sensitive biomarker for stress in humans. Little is known about CGA and its derived peptides, catestatin (CST) and vasostatin (VS), in dogs undergoing surgery. The objectives of this study were to investigate and compare concentrations of CGA epitopes CST and VS, cortisol, body temperature, heart rate, respiratory rate, scores of the short form of the Glasgow composite measure pain scale (CMPS-SF) and visual analog scales (VAS) for stress and pain behavior in dogs before and after ovariohysterectomy. Methods: Thirty healthy privately owned female dogs admitted for elective ovariohysterectomy were included. Physical examination, CMPS-SF, pain behavior VAS, and stress behavior VAS were recorded and saliva and blood samples were collected before surgery, 3h after extubation, and once at recall 7–15 days after surgery. Dogs were premedicated with morphine and received carprofen as analgesia for 7 days during the postoperative period. Results: At 3h after extubation, CMPS-SF and pain behavior VAS scores had increased (p<0.0001) and stress behavior VAS scores, temperature, respiratory rate (p<0.0001), plasma CST concentrations (p=0.002) had decreased significantly compared to before surgery. No significant differences were observed in the subjective and physiological parameters between before surgery and at recall, but plasma CST (p=0.04) and serum cortisol (p=0.009) were significantly lower at recall. Plasma VS, saliva CST, and heart rate did not differ significantly at any observed time. Conclusion: Study parameters for evaluating surgery-induced stress and pain changed in dogs subjected to ovariohysterectomy. To further evaluate CST and VS usefulness as pain biomarkers, studies on dogs in acute painful situations are warranted

    Gain saturation and output power of distributed feedback lasers

    No full text
    A study is made of distributed feedback lasers operating above threshold. A set of non-linear differential equations governing the field distribution is obtained. Some properties of these equations are discussed analytically. Then the results of some numerical calculations are presented. As a result, it is shown that the field distribution inside the laser deviates notably from the linear case. Some explanations of what the analysis means in physical terms and how the different operating regimes are characterized are provided
    corecore