INVESTIGATION OF THE CHANGES OF THE MASS MOMENTS OF INERTIA DURING A DOUBLE STEP OF RUNNING

INTRODUCTION: A new method for the investigation of athletes' motion takes into consideration the changes of the principal moments of inertia and their directions during the interval of the motion, because these characterize both the changes and the loss of energy. This paper investigates the motion of a runner. The applied model is a refined Hanavan model [1], representing the human body with 16 simple geometric solids determined by the spatial co-ordinates of 20 key points. METHODS AND PROCEDURES: The records were made by The Biomechanics Department of the Hungarian University of Physical Education with several video cameras. For the digitalization of the frames the APAS (Ariel Performance Analysis System) was used. The data of the digitized key points were analyzed by the system (MAS = Motion Analyzing System), developed for PC at the Department of Applied Mechanics of the Technical University of Budapest. Fig. 1 shows 11 different phases of the motion in the same picture. The time interval between the first and last phase is 0.9 sec. During the analysis 46 frames were digitized with a time-interval of 0.02 sec. This paper investigates the changes of the eigensystem for the mass moments of inertia of the whole human body with respect to the center of mass during the interval of the motion

Honvédelem és természetvédelem. A honvédelmi ágazat részvétele a LIFE-projektekben = Defence and Nature Protection – Participation of the Hungarian Defence Sector in the LIFE Projects

A hadsereg mint a működési környezetét tevőlegesen alakító társadalmi alrendszer, egyre intenzívebb és összetettebb kölcsönhatásban van a természeti és a társadalmi környezettel. A honvédelmi szervezetek szabályozott és intézményesített keretek között, mindennapi tevékenyégeik tervezése, szervezése és végrehajtása során tevékenyen törekszenek a környezet- és természetvédelmi tárgyú szabályzókban rögzített kötelezettségek teljesítésére, valamint aktívan részt vesznek a keletkezett károk hatásainak csökkentésében, a károk következményeinek felszámolásában. Ez a tanulmány a hazai honvédelmi ágazat LIFE-projektekben való részvételét elemzi

The debug slicing of logic programs

This paper extends the scope and optimality of previous algorithmic debugging techniques of Prolog programs using slicing techniques. We provide a dynamic slicing algorithm (called Debug slice) which augments the data flow analysis with control-flow dependences in order to identify the source of a bug included in a program. We developed a tool for debugging Prolog programs which also handles the specific programming techniques (cut, if-then, OR). This approach combines the Debug slice with Shapiro's algorithmic debugging technique

State feedback design considering overexcitation

The state equation describing the relationship between the input signal u(t), the state variable x(t) and the output signal y(t) of a linear, time invariant nth order SISO process is:\textit dx/dt=Ax+Bu, y=Cx+Du. The transfer function between the output signal and the input signal of the process is: \textity(s)/u(s)=Wp(s) and the time constants characterizing the delays of signals due to energy storage elements result from the eigenvalues of the state matrix A. In the classical feedback control system, the controller computes the control signal according to the expression u(s)= Wc(s)[ua(s)-y(s)]. The reduction of signal delay in the process is implemented by the PID algorithm described by the transfer function Wc(s) that accelerates the feedback system by \textitoverexciting the control signal to a specified extent. The reduction of signal delay in the process can also be implemented by negative feedback of the state variables x. If the process is state controllable and the control signal is computed according to the algorithm u=kcua-Fx, the time constants of the feedback system can be freely specified by appropriate selection of F and kc. The design of the feedback gain F can be performed using the \textitAckermann formula; the system is accelerated by means of \textitoverexcitation of the control signal to an appropriate extent even in this case. The paper presents the fact that the gain can be chosen according to kc=[C(A-BF-1B]-1CA-1B, and the overexcitation ratio of the control signal can be calculated using the relationship u(0)/u(∞ )=[1+F(A-BF)-1B]-1. This overexcitation ratio is in connection with the rate of pole transfers that can be expressed analytically. It occurs frequently that the state variables x of the process cannot play any part in the computation of the control signal since the state variables cannot be measured. In such cases, the state feedback can be implemented from the state variables x*(t) of a state observer according to the expression u=kcuaFx*. The paper presents the fact that the state feedback implemented based on the state observer - as opposed to the common concept - can also be interpreted as a state feedback of the process model, with the task of computing the control signa l that fulfils the requirements of acceleration. This signal is applied at the input of both the process model and the real process

Records of Ephemeroptera, Odonata and Plecoptera from Lithuania, with notes on aquatic arthropods

This paper provides data on 47 Ephemeroptera, 19 Odonata and 11 Plecoptera species from Lithuania. Data of some other aquatic arthropods are also given. Limnius intermedius Fairmaire, 1881 and Potamophilus acuminatus (Fabricius, 1792) (Coleoptera) are new to Lithuania