23 research outputs found

    Classical solutions of sigma models in curved backgrounds by the Poisson-Lie T-plurality

    Get PDF
    Classical equations of motion for three-dimensional sigma-models in curved background are solved by a transformation that follows from the Poisson-Lie T-plurality and transform them into the equations in the flat background. Transformations of coordinates that make the metric constant are found and used for solving the flat model. The Poisson-Lie transformation is explicitly performed by solving the PDE's for auxiliary functions and finding the relevant transformation of coordinates in the Drinfel'd double. String conditions for the solutions are preserved by the Poisson-Lie transformations. Therefore we are able to specify the type of sigma-model solutions that solve also equations of motion of three dimensional relativistic strings in the curved backgrounds. Simple examples are given

    A MYOELECTRIC PROSTHETIC ARM CONTROLLED BY A SENSOR-ACTUATOR LOOP

    Get PDF
    This paper describes new methods and systems designed for application in upper extremity prostheses. An artificial upper limb with this system is a robot arm controlled by EMG signals and a set of sensors. The new multi-sensor system is based on ultrasonic sensors, infrared sensors, Hall-effect sensors, a CO2 sensor and a relative humidity sensor. The multi-sensor system is used to update a 3D map of objects in the robot’s environment, or it directly sends information about the environment to the control system of the myoelectric arm. Occupancy grid mapping is used to build a 3D map of the robot’s environment. The multi-sensor system can identify the distance of objects in 3D space, and the information from the system is used in a 3D map to identify potential collisions or a potentially dangerous environment, which could damage the prosthesis or the user. Information from the sensors and from the 3D map is evaluated using a fuzzy expert system. The control system of the myoelectric prosthetic arm can choose an adequate reaction on the basis of information from the fuzzy expert system. The systems and methods were designed and verified using MatLab/Simulink. They are aimed for use as assistive technology for disabled people

    A MYOELECTRIC PROSTHETIC ARM CONTROLLED BY A SENSOR-ACTUATOR LOOP

    Get PDF
    This paper describes new methods and systems designed for application in upper extremity prostheses. An artificial upper limb with this system is a robot arm controlled by EMG signals and a set of sensors. The new multi-sensor system is based on ultrasonic sensors, infrared sensors, Hall-effect sensors, a CO2 sensor and a relative humidity sensor. The multi-sensor system is used to update a 3D map of objects in the robot’s environment, or it directly sends information about the environment to the control system of the myoelectric arm. Occupancy grid mapping is used to build a 3D map of the robot’s environment. The multi-sensor system can identify the distance of objects in 3D space, and the information from the system is used in a 3D map to identify potential collisions or a potentially dangerous environment, which could damage the prosthesis or the user. Information from the sensors and from the 3D map is evaluated using a fuzzy expert system. The control system of the myoelectric prosthetic arm can choose an adequate reaction on the basis of information from the fuzzy expert system. The systems and methods were designed and verified using MatLab/Simulink. They are aimed for use as assistive technology for disabled people

    WEARABLE MULTI-SENSOR SYSTEM FOR TELEMEDICINE APPLICATIONS

    Get PDF
    In this paper, we describe a technical design of wearable multi-sensor systems for physiological data measurement and wide medical applications, significantly impacted in telehealth. The monitors are composed of three analog front-end (AFE) devices, which assist with interfacing digital electronics to the noise-, time-sensitive physiological sensors for measuring ECG (heart-rate monitor), RR (respiration-rate monitor), SRL (skin resistivity monitor). These three types of sensors can be used separately or together and allow to determine a number of parameters for the assessment of mental and physical condition. The system is designed based on requirements for demanding environments even outside the realm of medical applications, and in accordance with Health and Safety at Work directives (89/391/CE and Seveso-II 96/82/EC) for occupational hygiene, medical, rehabilitation, sports and fitness applications

    CONTROL AND ANALYSIS OF SIMULATOR AND BIOLOGICAL DATA FROM CAR SIMULATORS

    Get PDF
    Due to the fact that driving vehicles can be complicated or impracticable, a computer simulator is usually used for training and professional studies. The advantage of this approach is high safety, repeatability, easier feasibility and, of course, lower price. In this work we describe the extension of the car simulator developed by the Faculty of Transport CTU in Prague with specific scenarios for evaluating the cognitive abilities of probands, software for their management and evaluation of data from simulator software and other measured physiological variables such as ECG and arm movement. From the data it is then possible to evaluate the mental and physical condition of the proband and the progress of training. Preliminary results suggest the possibility of using Poincaré analysis for the purpose of assessing cognitive load during potential collision situations. It uses distance assessment from other objects involved in traffic situations

    EVALUATION AND TYPES OF ATTACKS WITH STABBING WEAPONS FOR THE DESIGN OF PROTECTIVE EQUIPMENT

    Get PDF
    Knife attacks have become a global problem in recent years, especially in countries where access to firearms is limited. However, the current situation is that the method of selection and characteristics of protective equipment about the physical attributes of stabbing attacks is not systematically determined. Attacks with stab weapons can be divided according to the weapon's grip, the angle of the attack, and its execution into six different attacks (e.g., underarm action stab, overarm action stab, etc.). Our work presents a survey of methods for capturing and then evaluating the physical parameters of point attacks in specific motion capture and analysis programs. In this work, kinematic analysis was used to analyze motion during a stabbing attack and to obtain data on the kinetic energy of the stab. The measurements were performed with the MoCap system - Vicon Nexus 2.70. The results of the study show that the average value for the straight stab and the underarm stab is almost the same (66.5–67.1 J), while the overarm stab reaches a much higher value (92.8 J). The study aims to determine the kinetic energy of types of attacks, for standards state the level of protection based on energy levels. The results could provide new insights into the current state of protective equipment and energy values ​​in national/international standards

    Financial Analysis of Bohemia Sekt, Ltd.

    Full text link
    Cílem této bakalářské práce je provést finanční analýzu společnosti Bohemia Sekt, s.r.o. v letech 2008 - 2012. Na základě této analýzy je zhodnocen vývoj finanční situace podniku v těchto letech. Práce je rozdělena do dvou částí. První část je teoretická a za pomoci literatury charakterizuje metodický aparát finanční analýzy. V části druhé, praktické, jsou aplikovány veškeré popsané metody z první části na konkrétní hodnoty. Vybrané ukazatelé jsou následně porovnány s hodnotami odvětví. Závěr obsahuje shrnutí výsledků z praktické části a zhodnocení finanční situace společnosti.The main goal of this bachelor's thesis is to elaborate financial analysis of Bohemia Sekt, Ltd. between years 2008 - 2012. Further, it will evaluate the company's financial situation in this period on the basis of this analysis. The work is divided into two major sections, the theoretical and practical section. The theoretical part describes all methods of the financial analysis which are used in the second part. In the practical part, all the methods and ratios from the theoretical part are applied. Particular financial ratios are compared to sector's values. The conclusion summarizes all the results from the practical part and evaluates the financial situation of the company
    corecore