Szervezetfejlesztés gyakorlata egy hazai vállalat estében = Practice of organizational development in a domestic company

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Novel Design of a Model Reference Adaptive Controller for Soft Tissue Operations

Model Reference Adaptive Controllers (MRAC) have dual functionality: besides guaranteeing precise trajectory track- ing of the controlled system, they have to provide an “external control loop” with the illusion that it controls a physical system of prescribed dynamic properties, i.e., the “reference system”. The MRACs are designed traditionally by Lyapunov’s 2 nd method that is mathematically complicated, requiring strong skills from the designer. Adaptive controllers alternatively designed by the use of Robust Fixed Point Transformations (RFPT) operate according to Banach’s Fixed Point Theorem , and are normally simple iterative constructions that also have a standard variant for MRAC design. This controller assumes a single actuator that is driven adaptively. Master–Slave Systems form a distinct class of practical applications, in which two arms—the master and the slave—operate simultaneously. The movement of the master must be tracked precisely by the slave in spite of the quite different forces exerted by them. In the present paper, a soft tissue-cutting operation by a master–slave structure is simulated. The master arm has a simple torque–reference friction model, and is driven by the surgeon. The obtained master arm trajectory has to be precisely tracked by the electric DC motor driven slave system, which is in dynamic interaction with the actual tissue under operation. It is shown via simulations that the RFPT-based design can efficiently solve such tasks without considerable mathematical complexity

Társadalmi konfliktusokat generáló ökológiai történések a Balaton életében az utóbbi néhány évtizedben – Halpusztulások

Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Mass Fish Kills In this paper we summed up the history and causes of the mass fish kill events documented at Lake Balaton during the last 50 years. The first catastrophic fish kill (resulting in 500 t dead fish) was caused by the leaching of PCBs used on the catchment area of the lake in 1965. From the 1970s to the end of the ’90s, in parallel with the increasing eutrophication fish kills became more frequent, which impacted the whole fish fauna and spread over the lake. In the last years with the ongoing oligotrophication the mass kills terminated. Only sporadic species specific deaths were registered.Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Mass Fish Kills In this paper we summed up the history and causes of the mass fish kill events documented at Lake Balaton during the last 50 years. The first catastrophic fish kill (resulting in 500 t dead fish) was caused by the leaching of PCBs used on the catchment area of the lake in 1965. From the 1970s to the end of the ’90s, in parallel with the increasing eutrophication fish kills became more frequent, which impacted the whole fish fauna and spread over the lake. In the last years with the ongoing oligotrophication the mass kills terminated. Only sporadic species specific deaths were registered

Társadalmi konfliktusokat generáló ökológiai történések a Balaton életében az utóbbi néhány évtizedben – A halfogás csökkenése

Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Decreasing Fish Catches The fisheries sector was the chief utilizer of fish stocks living in the Lake Balaton for centuries, however with recreational use in the forefront the importance of angling has considerably increased in the last sixty years. Due to the diminishing of spawning areas of native fish species, the unadvised stocking of non native ones (silver carp, eel), and the ongoing oligotrophication during the last fifteen years the fish stock size and composition of the lake has changed significantly. Decreasing fish catches and contrasting intrests generate numerous conflicts between fishermen and recreational anglers.Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Decreasing Fish Catches The fisheries sector was the chief utilizer of fish stocks living in the Lake Balaton for centuries, however with recreational use in the forefront the importance of angling has considerably increased in the last sixty years. Due to the diminishing of spawning areas of native fish species, the unadvised stocking of non native ones (silver carp, eel), and the ongoing oligotrophication during the last fifteen years the fish stock size and composition of the lake has changed significantly. Decreasing fish catches and contrasting intrests generate numerous conflicts between fishermen and recreational anglers

Weak integrability breaking and level spacing distribution

Recently it was suggested that certain perturbations of integrable spin chains lead to a weak breaking of integrability in the sense that integrability is preserved at the first order in the coupling. Here we examine this claim using level spacing distribution. We find that the volume dependent crossover between integrable and chaotic level spacing statistics which marks the onset of quantum chaotic behaviour, is markedly different for weak vs. strong breaking of integrability. In particular, for the gapless case we find that the crossover coupling as a function of the volume $L$ scales with a $1/L^2$ law for weak breaking as opposed to the $1/L^3$ law previously found for the strong case.Comment: 15 pages, 12 figures. v2: references added. v3: text thoroughly revised, presentation clarified and improved, main results and conclusions unchange

Determining matrix elements and resonance widths from finite volume: the dangerous mu-terms

The standard numerical approach to determining matrix elements of local operators and width of resonances uses the finite volume dependence of energy levels and matrix elements. Finite size corrections that decay exponentially in the volume are usually neglected or taken into account using perturbation expansion in effective field theory. Using two-dimensional sine-Gordon field theory as "toy model" it is shown that some exponential finite size effects could be much larger than previously thought, potentially spoiling the determination of matrix elements in frameworks such as lattice QCD. The particular class of finite size corrections considered here are mu-terms arising from bound state poles in the scattering amplitudes. In sine-Gordon model, these can be explicitly evaluated and shown to explain the observed discrepancies to high precision. It is argued that the effects observed are not special to the two-dimensional setting, but rather depend on general field theoretic features that are common with models relevant for particle physics. It is important to understand these finite size corrections as they present a potentially dangerous source of systematic errors for the determination of matrix elements and resonance widths.Comment: 26 pages, 13 eps figures, LaTeX2e fil

Screening of bat faeces for arthropod-borne apicomplexan protozoa: Babesia canis and Besnoitia besnoiti-like sequences from Chiroptera

Background : 45 Microbats (Chiroptera: Microchiropte ra) are among the most eco - epidemiologically important 46 mammals, owing to their presence in human settlements and ani mal keeping facilities . 47 Roosting of bats in buildings may bring pathogens of veterinary - medical importance into the 48 environment of domestic animals and humans. In this context bats have long been studied as 49 carriers of various pathogen groups. However, despite their close association with arthropods 50 (both in their f oo d and as their ectoparasites), only a few molecular surveys have been 51 publish ed on their role as carriers of vector - borne protozoa. The aim of the present study was 52 to compensate for this scarcity of information. 53 Findings : 54 Altogether 221 (mostly individual) bat faecal samples were collected in Hungary and the 55 Netherlands. The DNA w as extracted , and analysed with PCR and sequencing for the 56 presence of arthropod - borne apicomplexan protozoa. Babesia canis canis (with 99 - 100% 57 homology) was identified in five samples, all from Hungary. Because it was excluded with an 58 Ixodidae - specific PC R that the relevant bats consumed ticks, these sequences derive either 59 from insect carriers of Ba. canis , or from the infection of bats. In one bat faecal sample from 60 the Netherlands a sequence having the highest (99%) homology to Besnoitia besnoiti was 61 am plified. 62 Conclusions : 63 The se findings suggest that some aspects of the epidemiology of canine babesiosis are 64 underestimated or unknown, i.e. the potential role of insect - borne mechanical transmission 65 and/or the susceptibility of bats to Ba. canis . In addit ion, b ats need to be added to future 66 studies in the quest for the final host of Be. besnoiti