Bilinear Forms on Finite Abelian Groups and Group-Invariant Butson Hadamard Matrices

Let $K$ be a finite abelian group and let $\exp(K)$ denote the least common multiple of the orders of the elements of $K$. A $BH(K,h)$ matrix is a $K$-invariant $|K|\times |K|$ matrix $H$ whose entries are complex $h$th roots of unity such that $HH^*=|K|I$, where $H^*$ denotes the complex conjugate transpose of $H$, and $I$ is the identity matrix of order $|K|$. Let $\nu_p(x)$ denote the $p$-adic valuation of the integer $x$. Using bilinear forms on $K$, we show that a $BH(K,h)$ exists whenever (i) $\nu_p(h) \geq \lceil \nu_p(\exp(K))/2 \rceil$ for every prime divisor $p$ of $|K|$ and (ii) $\nu_2(h) \ge 2$ if $\nu_2(|K|)$ is odd and $K$ has a direct factor $\mathbb{Z}_2$. Employing the field descent method, we prove that these conditions are necessary for the existence of a $BH(K,h)$ matrix in the case where $K$ is cyclic of prime power order

ENVIRONMENTAL AND ECONOMIC ACCOUNTING FOR THE GERMAN AGRICULTURAL SECTOR

How can we estimate the negative externalities of agriculture at the national level, and attribute these to specific production activities and outputs? The paper presents a method that calculates the mass flow in the whole agricultural sector including inputs from other sectors, and that allows to analyse resource use and emissions, e.g. of greenhouse gases. Data inputs are the German economic accounts for agriculture, farm structural survey and market statistics, as well as environmental statistics. In the framework of the German agricultural sector model RAUMIS, material flows within the agricultural sector are described, as well as inputs from other German sectors and imports. Through a processanalytical approach, all information is integrated and matrices of resource use and emissions for all agricultural production activities are generated. A monetary allocation is used to identify the respective activities that are responsible for emissions, including indirect emissions in upstream sectors. Related to the market output, cumulative emissions per unit of output can be computed. Results for the period from 1995 to 2007 show the trend of resource uses and emissions for the national average values of important commodities such as milk and meat.SEEA, Input-Output Analysis, agriculture, resource use, trade, emissions, carbon footprint, Livestock Production/Industries, Resource /Energy Economics and Policy,

Fundamentals of Earth Observation Policy: Examples for German and European Missions

Several European countries have developed their national high resolution earth observation systems. Some of them are operated in close cooperation with industrial partners, others are dual-use missions earmarked to fulfil the needs of national security. In addition, the European Space Agency and the European Commission have initiated the Global Monitoring for Environment and Security (GMES) project. Therein, a fleet of satellites (SENTINELs) will deliver data for European wide information services, augmented by data from national and non-European earth observation systems. This new scenario needs clear guidance and regulations. Besides the principles for operations of earth observation missions – as set out in UN principles on earth observation – the operators of very high resolution missions require clear governmental acts which international users can be served and which data might be restricted in distribution. For national science and the SENTINEL-missions, a policy for free and open access is being developed to guarantee a maximum use of the data. Exemplified on the German national missions and the European GMES scenario, data policies and regulations for existing and new earth observation missions will be explained

Cyclotomic Integers of Prescribed Absolute Value and the Class Group

AbstractWe obtain a new method for the study of class groups of cyclotomic fields by investigating cyclotomic integers of prescribed absolute value. Explicit subgroups of the classgroupCmodulo the class groupC+of the maximal real subfield are exhibited and lower bounds on their orders are derived. For themth cyclotomic fieldKm, wherem=pam′, (p, m′)=1, andpis a prime, we determine the structure ofC+CP/C+CQup to a binary parameter; hereCP,CQare the subgroups ofCgenerated by the classes [Pi] respectively [Qi], wherepfactors inKmas ∏Qi,Qi=Pϕ(pa)i, and thePiare prime ideals

Optimizing Scrubbing by Netlist Analysis for FPGA Configuration Bit Classification and Floorplanning

Existing scrubbing techniques for SEU mitigation on FPGAs do not guarantee an error-free operation after SEU recovering if the affected configuration bits do belong to feedback loops of the implemented circuits. In this paper, we a) provide a netlist-based circuit analysis technique to distinguish so-called critical configuration bits from essential bits in order to identify configuration bits which will need also state-restoring actions after a recovered SEU and which not. Furthermore, b) an alternative classification approach using fault injection is developed in order to compare both classification techniques. Moreover, c) we will propose a floorplanning approach for reducing the effective number of scrubbed frames and d), experimental results will give evidence that our optimization methodology not only allows to detect errors earlier but also to minimize the Mean-Time-To-Repair (MTTR) of a circuit considerably. In particular, we show that by using our approach, the MTTR for datapath-intensive circuits can be reduced by up to 48.5% in comparison to standard approaches

Erfahrungen mit dem Einsatz von Akupunktur bei Rindern – eine Befragung von Tierärzten und Tierheilpraktikern

Aim of the study was to collect user experiences with acupuncture treatments for cattle. Twenty-six veterinarians and 17 animal healers were interviewed for this study. On average, each interviewed practitioner had treated four cattle diseases with acupuncture, mainly in dairy cows and dairy calves. Acupuncture often was used in combination with other therapeutic methods. Altogether, the interviewed practitioners of bovine acupuncture were satisfied with the results

Managing the E-Government Organization

This article examines the internal and external administrative factors conducive and inhibitive of the development of e-government. It develops a conceptual framework on the basis of existing experiences drawn from administrative reforms. Using data from a large survey of public managers in the German federal government to test guidelines and prescriptions provided in the article, this study indicates that the elements and guidelines developed in our research have had a direct or indirect influence on the development of e-government. Finally, the article indicates further research requirements, as well as consequences for practical project design