In the 1930’s, Tarski introduced his plank problem at a time when the field Discrete Geometry was about to born. It is quite remarkable that Tarski’s question and its variants continue to generate interest in the geometric and analytic aspects of coverings by planks in the present time as well. The paper is of a survey type with some new results and with a list of open research problems on the ...

In this paper we present and review a number of fundamental constraints that exist on the propagation of orbit uncertainty and phase volume flows in astrodynamics. These constraints arise due to the Hamiltonian nature of spacecraft dynamics. First we review the role of integral invariants and their connection to orbit uncertainty, and show how they can be used to formally solve the diffusion-le...

This article describes the AC Stark, Stern-Gerlach, and Quantum Zeno effects as they are manifested during continuous interferometric measurement of a two-state quantum system (qubit). A simple yet realistic model of the interferometric measurement process is presented, and solved to all orders of perturbation theory in the absence of thermal noise. The statistical properties of the interferome...

Procedures for the control of timber strength grading machines have been established, including both machine control and output control. For the machine control so called control planks have been developed which enables a dynamic control of the whole grading system, i.e. the grading machine as well as infeed and outfeed equipment. Some generic control plank designs have been developed which may...

This study aims to determine the effect of core stability exercises (Elbow Plank, High and Elbow Plank With Legs Open) on abdominal muscle strength balance. Quasi-experimental research design using nonequivalent control group design. The purposive sampling technique was used in this subjects where total obtained 32 people. instruments were sit up test (30 seconds) measure standing stork results...

The polymer translocation into nanopores is generally facilitated by external driving forces, such as electric or hydrodynamic fields, to compensate for entropic restrictions imposed by the confinement. We investigate the dynamics of translocation driven by polymer adsorption to the confining walls that is relevant to chromatographic separation of macromolecules. By using the self-consistent fi...

In previous work, we introduced the quasi-static retry traffic model, which describes the behavior of retry traffic generated by users who are impatient when waiting for a response from the system. In other words, the model describes interactions between users and the system. This interaction can be described in a simple form if it is assumed that the system offers infinitely fast (ideal) proce...

A realistic description of the variability in bacterial growth and division is critical to produce reliable predictions of safety risks along the food chain. Individual-based modeling of bacteria provides the theoretical framework to deal with this variability, but it requires information about the individual behavior of bacteria inside populations. In this work, we overcome this problem by est...

Almost all living species regularly explore environments that they experience as pleasant, aversive, arousing or frightening. We postulate that such exploratory behavior and emotional experience both are regulated based on the interdependent perception of one's body and stimuli that collectively define a spatial context such as a cliff. Here we examined this by testing if the interaction of the...