Search results for "Robot"

Bot recognition in a Web store: An approach based on unsupervised learning

2020

Abstract Web traffic on e-business sites is increasingly dominated by artificial agents (Web bots) which pose a threat to the website security, privacy, and performance. To develop efficient bot detection methods and discover reliable e-customer behavioural patterns, the accurate separation of traffic generated by legitimate users and Web bots is necessary. This paper proposes a machine learning solution to the problem of bot and human session classification, with a specific application to e-commerce. The approach studied in this work explores the use of unsupervised learning (k-means and Graded Possibilistic c-Means), followed by supervised labelling of clusters, a generative learning stra…

Idiopathic Retroperitoneal Fibrosis: What Is the Optimal Clinical Approach for Long-Term Preservation of Renal Function?

2022

<b><i>Background:</i></b> The aim of this study was to investigate the long-term effects of ureteral stenting and the exact timing of stent removal in favor of surgery in patients with idiopathic retroperitoneal fibrosis (IRF). <b><i>Summary:</i></b> Medline research terms of “idiopathic retroperitoneal fibrosis” AND “ medical therapy” OR “ureteral stenting” OR “surgical treatment” were done. Systematic reviews and observational and clinical studies were analyzed to obtain indication regarding the objective of the study for a narrative review. Ninety-two papers were analyzed. The treatment of IRF includes the monitoring of retroperitoneal fibr…

Robotic versus laparoscopic radical hysterectomy in early cervical cancer: A case matched control study

2018

Abstract Background This study aims at evaluating the feasibility, surgical outcome and oncological results observed after robotic radical hysterectomy (RH) compared to laparoscopy for patients with early stage cervical cancer (ECC) patients. Methods Between January 2010 and October 2016, 210 patients underwent RH for treatment of ECC: 70 underwent robotic approach (Cases), and 140 underwent laparoscopic approach (Controls). Results There was no statistically significant difference between the two approaches with regard to clinical patient characteristics and in terms of extent of RH and rate of pelvic and aortic lymphadenectomy. Operative time was significantly longer in the robotic versus…

LQG Control Design for Balancing an Inverted Pendulum Mobile Robot

2011

Author's version of an article published in the journal: Intelligent Control and Automation. Also available from the publisher at: http://dx.doi.org/10.4236/ica.2011.22019 The objective of this paper is to design linear quadratic controllers for a system with an inverted pendulum on a mobile robot. To this goal, it has to be determined which control strategy delivers better performance with respect to pendulum’s angle and the robot’s position. The inverted pendulum represents a challenging control problem, since it continually moves toward an uncontrolled state. Simulation study has been done in MATLAB Simulink environment shows that both LQR and LQG are capable to control this system succe…

Application of Wavelet Networks to Adaptive Control of Robotic Manipulators

2011

Published version of a chapter in the book: Intelligent Robotics and Applications. Also available from the publisher at; http://dx.doi.org/10.1007/978-3-642-25489-5_39 In this paper, a wavelet-based adaptive control is proposed for a class of robotic manipulators, which consist of nonlinearities for friction effects and uncertain terms as disturbances. The controller is calculated by using a mixed of feedback linearization technique, supervisory control and H∞ control. In addition, the parameter adaptive laws of the wavelet network are developed using a Lyapunov-based design. It is also shown that both system tracking stability and convergence of the error estimation can be guaranteed in th…

Forward Kinematic Modelling with Radial Basis Function Neural Network Tuned with a Novel Meta-Heuristic Algorithm for Robotic Manipulators

2022

The complexity of forward kinematic modelling increases with the increase in the degrees of freedom for a manipulator. To reduce the computational weight and time lag for desired output transformation, this paper proposes a forward kinematic model mapped with the help of the Radial Basis Function Neural Network (RBFNN) architecture tuned by a novel meta-heuristic algorithm, namely, the Cooperative Search Optimisation Algorithm (CSOA). The architecture presented is able to automatically learn the kinematic properties of the manipulator. Learning is accomplished iteratively based only on the observation of the input–output relationship. Related simulations are carried out on a 3-Degrees…

Positive Turn in Elder-Care Workers' Views Toward Telecare Robots.

2022

AbstractRobots have been slowly but steadily introduced to welfare sectors. Our previous observations based on a large-scale survey study on Finnish elder-care workers in 2016 showed that while robots were perceived to be useful in certain telecare tasks, using robots may also prove to be incompatible with the care workers’ personal values. The current study presents the second wave of the survey data from 2020, with the same respondents (N = 190), and shows how these views have changed for the positive, including higher expectations of telecare robotization and decreased concerns over care robots’ compatibility with personal values. In a longitudinal analysis (Phase 1), the positive change…

Fatigue fracture plane under Multiaxial Random Loadings - prediction by variance of equivalent stress based on the maximum shear and normal stresses

1992

It is assumed that the plane in which the maximum variance of the equivalent stress appears is critical for a material and the fatigue fracture should be expected in this plane. The equivalent stress is calculated according to the fatigue criterion of maximum shear and normal stresses in the fracture plane. It was demonstrated that for each stationary random stress state there is one or more critical planes where the fatigue fracture plane can be expected. The variance method together with the discussed fatigue criterion give good results for three analysed types of carbon steels under multiaxial cyclic loadings.

Vauraus, luotto, luottamus : talonpoikien lainasuhteet Pohjanlahden molemmin puolin 1796-1830

2014

Asymptotic observer of the link states of flexible joint robots with motor-side sensing

2015

This paper proposes an approach for observing the link states, i.e. angular position and velocity, of the robotic joints with elasticities, when only the motor-side sensing is available. By separating the state-dependent nonlinearities of the rigid manipulator dynamics a linear sub-model of the elastic joint robot is obtained in an observable state-space form. The standard asymptotic Luenberger state observer is then designed for the given motor position signal which is measured by encoder and rectified from the nonlinear contribution. The configurable poles of observer allow shaping the estimated states dynamics to be fast enough in relation to the actual resonant joint behavior. Therefore…