591 research outputs found
On the geometry of full points of abstract unitals
The concept of full points of abstract unitals has been introduced by
Korchm\'aros, Siciliano and Sz\H{o}nyi as a tool for the study of projective
embeddings of abstract unitals. In this paper we give a more detailed
description of the combinatorial and geometric structure of the sets of full
points in abstract unitals of finite order
Some neuroprotective approaches in focal and global ischaemia on in vivo and in vitro rat models
Active suspension control design for unmanned ground vehicles
This paper presents the design of an active suspension control system for an unmanned ground vehicle (UGV). The purpose is to design an active suspension control for a low-speed (less than 1 m/s) off-road UGV in order to be able to move through rugged terrain with the least pitch and roll motion. Classical active suspension design methods cannot be used for minimizing pitch and roll angles, therefore a new approach is applied. The control design is based on the LQG method. The control system uses only pitch and roll angular rate signals, which ensures a simple and cheap control system, but any bias error on the gyro signals cause some problems in reconstructing angles. The control algorithm consists of an optimal state-feedback fed by an augmented observer for estimating the states and the bias error of the gyro sensors. The appropriate tuning of the observer is introduced, which eliminates the bias error problem and ensures the fast reconstruction of the states for the optimal state-feedback. In simulations, the active suspension control system shows high performance at minimizing pitch and roll angles
Distribution of millipedes (Myriapoda, Diplopoda) along a forest interior - forest edge - grassland habitat complex
Edge effects on ground-dwelling beetles (Carabidae and Staphylinidae) in oak forest-forest edge-grassland habitats in Hungary
New Steiner 2-designs from old ones by paramodifications
Techniques of producing new combinatorial structures from old ones are commonly called trades. The switching principle applies for a broad class of designs: it is a local transformation that modifies two columns of the incidence matrix. In this paper, we present a construction, which is a generalization of the switching transform for the class of Steiner 2-designs. We call this construction paramodification of Steiner 2-designs, since it modifies the parallelism of a subsystem. We study in more detail the paramodifications of affine planes, Steiner triple systems, and abstract unitals. Computational results show that paramodification can construct many new unitals
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