Ozone biomonitoring at mountainous and lowland areas in Hungary

Our experiment started in June, 2007. For test-plant we applied the ozone bioindicator clover (Trifolium repens NC-S and NC-R) clones. For cultivation of plants and for assessing the injuries the protocol of the ICP Vegetation (International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops) was used. The clover pots were located in three experimental sites. Gödöllô is in downs with moderate climate, Bugacpuszta is a lowland site with hot and dry climate while Mátraháza is a mountainous site. Besides injuries and total dry weight, the number of flowers and the leaf area index were also measured. Our results showed that the typical symptoms of ozone injury were appeared on sensitive clones on every site. The degree of injury increased gradually from June to September reaching the maximum in the middle of September. There were definite differences between the numbers of flowers: in Gödöllô and Bugac (where the ozone pollution was substantially lower) the plants developed much more flowers than in Mátraháza. Therefore the number of flowers could also be a useful indicator of tropospheric ozone in addition to the extent of ozone injuries

Globally linked pairs and cheapest globally rigid supergraphs

Given a graph $G$, a cost function on the non-edges of $G$, and an integer $d$, the problem of finding a cheapest globally rigid supergraph of $G$ in $\mathbb{R}^d$ is NP-hard for $d\geq 1$. For this problem, which is a common generalization of several well-studied graph augmentation problems, no approximation algorithm has previously been known for $d\geq 2$. Our main algorithmic result is a 5-approximation algorithm in the $d=2$ case. We achieve this by proving numerous new structural results on rigid graphs and globally linked vertex pairs. In particular, we show that every rigid graph in $\mathbb{R}^2$ has a tree-like structure, which conveys all the information regarding its globally rigid augmentations. Our results also yield a new, simple solution to the minimum cardinality version (where the cost function is uniform) for rigid input graphs, a problem which is known to be solvable in polynomial time.Comment: 27 pages, 5 figure

Der Springer Compact-Deal – Ein erster Einblick in die Evaluierung einer Offsetting-Vereinbarung

On January the 1st, 2016 a new agreement between 32 Austrian scientific libraries and the publisher Springer took its effect: this deal covers accessing the licensed content on the one hand, and publishing open access on the other hand. More than 1000 papers by Austrian authors were published open access at Springer in the first year alone. The working group "Springer Compact Evaluierung" made the data for these articles available via the platform OpenAPC and would like to use this opportunity to give a short account of what this publishing agreement actually entails and the working group intends to do

Globally linked pairs of vertices in generic frameworks

A $d$-dimensional framework is a pair $(G,p)$, where $G=(V,E)$ is a graph and $p$ is a map from $V$ to $\mathbb{R}^d$. The length of an edge $xy\in E$ in $(G,p)$ is the distance between $p(x)$ and $p(y)$. A vertex pair $\{u,v\}$ of $G$ is said to be globally linked in $(G,p)$ if the distance between $p(u)$ and $p(v)$ is equal to the distance between $q(u)$ and $q(v)$ for every $d$-dimensional framework $(G,q)$ in which the corresponding edge lengths are the same as in $(G,p)$. We call $(G,p)$ globally rigid in $\mathbb{R}^d$ when each vertex pair of $G$ is globally linked in $(G,p)$. A pair $\{u,v\}$ of vertices of $G$ is said to be weakly globally linked in $G$ in $\mathbb{R}^d$ if there exists a generic framework $(G,p)$ in which $\{u,v\}$ is globally linked. In this paper we first give a sufficient condition for the weak global linkedness of a vertex pair of a $(d+1)$-connected graph $G$ in $\mathbb{R}^d$ and then show that for $d=2$ it is also necessary. We use this result to obtain a complete characterization of weakly globally linked pairs in graphs in $\mathbb{R}^2$, which gives rise to an algorithm for testing weak global linkedness in the plane in $O(|V|^2)$ time. Our methods lead to a new short proof for the characterization of globally rigid graphs in $\mathbb{R}^2$, and further results on weakly globally linked pairs and globally rigid graphs in the plane and in higher dimensions.Comment: 22 pages, 5 figure

Die Option bei den Pariser Friedensverträgen in Bezug auf die Tschechoslowakei und Ungarn

In dieser Diplomarbeit wurden die Entstehung und Auswirkungen der völkerrechtlichen Optionsbestimmungen für die Fälle der Tschechoslowakei und Ungarn beleuchtet. Unter dem Begriff der Option versteht man ein seit mehreren Jahrhunderten praktiziertes Verfahren, Personen, die aufgrund von territorialen Veränderungen von Staaten zu Minderheiten geworden sind, über ihre Staatszugehörigkeit frei entscheiden zu lassen. Der spezielle Fokus richtete sich in der Diplomarbeit auf die Tschechoslowakei und Ungarn nach dem Ersten Weltkrieg. In diesem Rahmen stellen sich die Forschungsfragen über die Motive für die Schaffung der Optionsbestimmungen bei den Pariser Friedensverträgen in den Jahren 1919 und 1920, wobei dies mit einer erhofften Minderung von national motivierten Spannungen im osteuropäischen Raum beantwortet werden kann. In einem weiteren Schritt wurde die Entstehung von der Idee bis zur Implementierung in Staatsrecht und Durchführung nachgeforscht. Dabei wurde ersichtlich, dass die betroffenen Staaten die international festgelegten Optionsbestimmungen zwar akzeptierten, aber teils nur widerwillig durchführten. Anhand von Fallbeispielen wurde diese Erkenntnis untermauert. Durch die Nachforschung von einzelnen konkreten Optionsfällen wurde außerdem ein Einblick in die Schicksale der betroffen Personen gewährt