Socio-Economic Mechanisms to Coordinate the Internet of Services: The Simulation Environment SimIS

Visions of 21st century information systems show highly specialized digital services and resources, which interact continuously and with a global reach. Especially with the emergence of technologies, such as the semantic web or software agents, intelligent services within these settings can be implemented, automatically communicating and negotiating over the Internet about digital resources without human intervention. Such environments will eventually realize the vision of an open and global Internet of Services (IoS). In this paper we present an agent-based simulation model and toolkit for the IoS: 'SimIS - Simulating an Internet of Services'. Employing SimIS, distributed management mechanisms and protocols can be investigated in a simulated IoS environment before their actual deployment.Multi-Agent Simulation, Internet, Simulation Tools

High temperature susceptibility in electron doped Ca1-xYxMnO3: Double Exchange vs Superexchange

We present a study of the magnetic properties of the electron doped manganites Ca1-xYxMnO3 (for 0<=x<=0.25) in the paramagnetic regime. For the less doped samples (x<=0.1) the magnetic susceptibility, c(T), follows a Curie-Weiss (CW) law only for T > 450 K and, below this temperature, c^-1(T) shows a ferrimagnetic-like curvature. We approached the discussion of these results in terms of a simple mean-field model where double exchange, approximated by a ferromagnetic Heisenberg-like interaction between Mn3+ and Mn4+ ions, competes with classical superexchange. For higher levels of doping (x>=0.15), the CW behaviour is observed down to the magnetic ordering temperature (Tmo) and a better description of c(T) was obtained by assuming full delocalization of the eg electrons. In order to explore the degree of delocalization as a function of T and x, we analyzed the problem through Montecarlo simulations. Within this picture we found that at high T the electrons doped are completely delocalized but, when Tmo is approached, they form magnetic polarons of large spin that cause the observed curvature in c^-1(T) for x<=0.1.Comment: 15 pages, 10 figures, Submitted to J. Physics: Condensed Matter (06/28/02

How weather-proof is the construction sector? : empirical evidence from Germany

With the purpose to reduce winter unemployment and to promote all-season employment in the constructions sector, Germany maintains an extensive bad weather allowance system. Since the mid 1990s, these regulations have been subject to several reforms that resemble the range of approaches for employment promotion which can be found in other European countries. We analyse the effect of these reforms on individual unemployment risks using large individual administrative data merged with information about local weather conditions and the business cycle. We find a weaker direct link between seasonal layoffs and actual weather than broadly assumed, since most of the layoffs take place at fixed dates. The reforms under consideration have economically plausible effects; Regulations that limit an employer's financial burden reduce transitions to unemployment and render it less weather-dependent

The DNA-recognition mode shared by archaeal feast/famine-regulatory proteins revealed by the DNA-binding specificities of TvFL3, FL10, FL11 and Ss-LrpB

The DNA-binding mode of archaeal feast/famine-regulatory proteins (FFRPs), i.e. paralogs of the Esherichia coli leucine-responsive regulatory protein (Lrp), was studied. Using the method of systematic evolution of ligands by exponential enrichment (SELEX), optimal DNA duplexes for interacting with TvFL3, FL10, FL11 and Ss-LrpB were identified as TACGA[AAT/ATT]TCGTA, GTTCGA[AAT/ATT]TCGAAC, CCGAAA[AAT/ATT]TTTCGG and TTGCAA[AAT/ATT]TTGCAA, respectively, all fitting into the form abcdeWWWedcba. Here W is A or T, and e.g. a and a are bases complementary to each other. Apparent equilibrium binding constants of the FFRPs and various DNA duplexes were determined, thereby confirming the DNA-binding specificities of the FFRPs. It is likely that these FFRPs recognize DNA in essentially the same way, since their DNA-binding specificities were all explained by the same pattern of relationship between amino-acid positions and base positions to form chemical interactions. As predicted from this relationship, when Gly36 of TvFL3 was replaced by Thr, the b base in the optimal DNA duplex changed from A to T, and, when Thr36 of FL10 was replaced by Ser, the b base changed from T to G/A. DNA-binding characteristics of other archaeal FFRPs, Ptr1, Ptr2, Ss-Lrp and LysM, are also consistent with the relationship

The Effect of Minimum Wages on Labour Market Flows Evidence from Germany

Using a linked employer-employee data set on the German construction industry, we analyse the effects of the introduction of minimum wages in this sector on labour market dynamics at the establishment level, i.e. turnover and churning flows, as well as accessions and separations and their underlying worker flows. The fact that minimum wages in Germany are sector-specific enables us to apply a between approach using other industries as control groups in a difference-in-differences framework. Furthermore, we use a within approach with high-wage workers as control group. While the within approach shows that the minimum wage reduced worker flows in East Germany, the between approach yields positive effect on labour market dynamics in West Germany. Our results can be explained by differences between East and West Germany with respect to the bite of the minimum wage, as well as the much higher prevalence of posted workers in West Germany. Furthermore, spillover effects to highwage workers are likely to have played a role in East Germany.In dem Papier werden die Auswirkungen der Mindestlohneinführung im deutschen Bauhauptgewerbe auf Arbeitsmarktdynamiken untersucht, wobei die Analyse von Einstellungen und Trennungen sowie der damit zusammenhängenden Arbeitsmarktübergänge auf Betriebsebene erfolgt. Dabei kommt ein einzigartiger Linked Employer-Employee Datensatz zum Einsatz. Da der Mindestlohn zunächst nur im Bauhauptgewerbe eingeführt wurde, können Betriebe einer anderen Branche als Kontrollgruppe in einem Differenz-von-Differenzen-Ansatz genutzt werden (between-Ansatz). Zusätzlich wird ein within-Ansatz verwendet, bei dem Arbeitnehmer mit relativ hohem Lohn innerhalb des Bauhauptgewerbes als Kontrollgruppe dienen. Während der within-Ansatz zeigt, dass der Mindestlohn Arbeiterflüsse in Ostdeutschland reduzierte, bringt der between-Ansatz positive Effekte auf Arbeitsmarktdynamiken in Westdeutschland zutage. Diese Ergebnisse können auf Ost-West-Unterschiede hinsichtlich der Eingriffsintensität des Mindestlohns sowie die deutlich höhere Anzahl entsendeter Arbeitnehmer in Westdeutschland zurückgeführt werden. Zudem sind spillover-Effekte auf Arbeitnehmer mit relativ hohen Löhnen in Ostdeutschland wahrscheinlich

Quality of life in Type 1 (insulin-dependent) diabetic patients prior to and after pancreas and kidney transplantation in relation to organ function

Improvement of the quality of life in Type 1 (insulin-dependent) diabetic patients with severe late complications is one of the main goals of pancreas and/or kidney grafting. To assess the influences of these treatment modalities on the different aspects of the quality of life a cross-sectional study in 157 patients was conducted. They were categorized into patients pre-transplant without dialysis (n=29; Group A), pre-transplant under dialysis (n=44; Group B), post-transplant with pancreas and kidney functioning (n=31; Group C), post-transplant with functioning kidney, but insulin therapy (n=29; Group D), post-transplant under dialysis and insulin therapy again (n=15; Group E) and patients after single pancreas transplantation and rejection, with good renal function, but insulin therapy (n=9; Group F). All patients answered a mailed, self-administered questionnaire (217 questions) consisting of a broad spectrum of rehabilitation criteria. The results indicate a better quality of life in Groups C and D as compared to the other groups. In general the scores are highest in C, but without any significant difference to D. Impressive significant differences between C or D and the other groups were found especially in their satisfaction with physical capacity, leisure-time activities or the overall quality of life. The satisfaction with the latter is highest in C (mean±SEM: 4.0±0.2 on a 1 to 5-rating scale; significantly different from A: 3.1±0.1, B: 2.7±0.2 and E: 2.6±0.3; p<0.01), followed by D (3.8±0.2; significantly different from B and E; p<0.01). Group F shows a mean of 3.1±0.4, which is not significantly different from C. The percentages of patients in each group, who are not working: A: 38 %, B: 64 %, C: 74 %, D: 66 %, E: 87 % and F: 78 % indicate that there is no marked improvement in the vocational situation after successful grafting

Sailing into a dilemma : an economic and legal analysis of an EU trading scheme for maritime emissions

On the basis of a joint economic and legal analysis, we evaluate the effects of a “regional” (European) emission trading scheme aiming at reducing emissions of international shipping. The focus lies on the question which share of emissions from maritime transport activities to and from the EU can and should be included in such a system. Our findings suggest that the attempt to implement an EU maritime ETS runs into a dilemma. It is not possible to design a system that achieves emission reductions in a cost efficient manner and is compatible with international law

How Robust are Simulated Employment Effects of a Legal Minimum Wage in Germany?: A Comparison of Different Data Sources and Assumptions

Several empirical minimum wage studies have recently been published that simulate employment effects of a federal minimum wage in Germany. We disentangle various factors that explain the variation in previous simulation results. Based on data from the German Socio-Economic Panel and the newly available Verdienststrukturerhebung 2006 we conduct robustness analyses that systematically test the range in the outcomes of different labor demand simulations. We find that labor demand effects are sensitive to measurement errors in wages, the representativeness of the sample with respect to several types of labor inputs as well as estimated and assumed labor demand and output price elasticities. Interactions of those determinants may lead to substantial differences in simulation outcomes