Open Access

This thesis has been designed to improve the understanding of the distribution pattern and transport mechanisms of alkylphenols and the phthalates in the coastal margins, especially the roles of the air-sea exchanges in these processes. Henry’s Law Constants (HLC) were determined for the diastereomeric mixture of NP and t- OP in artificial seawater over given temperature range using a dynamic equilibrium system. An analytical method has been developed for the simultaneous extraction and determination of trace tertiary octylphenol (t-OP), technical nonylphenol isomers (NP), nonylphenol monoethoxylate isomers (NP1EO) and the phthalates in the atmosphere and sea water using gas chromatography-mass spectrometry (GC-MS). The method was successfully applied to the determination of APs and the phthalates in the atmosphere and sea water samples collected from the North Sea. A decreasing concentration profile of NP, t-OP, NP1EO and the phthalates appeared as the distance from the coast increased to the central part of the North Sea. Air-sea exchanges of t-OP, NP, DBP, BBP, and DEHP were estimated using the two-film resistance model based upon relative air-water concentrations. The average of air-sea exchange fluxes indicates a net deposition is occurring. These results suggest that the air–sea vapour exchange is an important process that intervenes in the mass balance of alkylphenols and the phthalates in the North Sea.

General Mental Ability, the Big Five, and several context specific variables are studied in regard to their relationship with two criteria of expatriate success, namely, adjustment and job performance. Interviews and standardized tests were conducted with a sample of 66 German and Austrian expatriates in South Korea. Results show no relationship with General Mental Ability for neither of the two criteria. Hypotheses for Conscientiousness and Emotional Stability were partially confirmed; Extraversion emerged to be negatively related to other-ratings of adjustment. Several context specific variables were found to be related to the criteria. Drawing from the study’s results, recommendations for future studies in the expatriate domain are provided.

This paper presents the first nonparametric test whether German works councils go hand in hand with higher labor productivity or not. It distinguishes between establishments that are covered by collective bargaining or not. Results from a Kolmogorov-Smirnov test for first order stochastic dominance tend to indicate that pro-productive effects are found in firms with collective bargaining only. However, the significance level of the test statistic is higher than a usually applied critical level. This somewhat weak evidence casts doubts on the validity of results from recent parametric approaches using a regression framework that point to high positive effects of works councils on productivity.

This paper studies the empirical effect of risk classification in the mandatory third-party motor insurance (TPMI) of Germany. We find evidence that inefficient risk categories had been selected in this market while potentially efficient information may have been dismissed. Risk classification did generally not improve the efficiency of contracting or the composition of insureds in this market. These findings can be partly explained by the existence of compulsory fixed coverage and other institutional restraints such as unitary owner insurance in this market.

The EU electricity directive (96/92/EC) established the right of the member states to choose between Regulated and Negotiated Third Party Access (RTPA and NTPA). The interest group theory is able to explain whether the introduction of NTPA in Germany had been an interest group equilibrium under the restriction of EU-directive. Using the NTPA associations of electricity power suppliers, network monopolists and industrial consumers negotiated three agreements. The last one (AA VVII+) in December 2001 introduced a market comparison scheme with three structural features: “East-/West-Germany”, “consumption/population density”, and “cable rate”. These features are variables which are supposed to reflect cost differences between network suppliers. The theoretical analysis will derive the hypothesis that this conception allows to introduce a cost irrelevant factor and therefore to increase prices without harming firms which do not hold this factor. This hypothesis could be tested by analyzing the German low and medium voltage network suppliers in 2002 and 2003. Our estimations show that the use of structural feature “East-/West Germany” and “consumption/population density” could be explained by this hypothesis. But because we have no firm specific information about cost differences other explanations could not be excluded: Monopoly prices differ with marginal costs, and regulation could reflect real cost differences. The third structural feature “cable rate” has no influence in low voltage networks, but has an impact on access charges levied in medium voltage networks. This relationship is only given if we use the borderlines given by AA VVII+. Hence, we are not able to reject the interest group theory: The feature “cable rate” was introduced successfully to increase access charges for medium network suppliers which have high cable rates without having higher costs.

Many public goods are characterized by rivalry and/or excludability. This paper introduces both non-excludable and excludable public inputs into a simple endogenous growth model. We derive the equilibrium growth rate and design the optimal tax and user-cost structure. Our results emphasize the role of congestion in determining this optimal financing structure and the consequences this has in turn for the government’s budget. The latter consists of fee and tax revenues that are used to finance the entire public production input and that may or may not suffice to finance the entire public input, depending upon the degree of congestion. We extend the model to allow for monopoly pricing of the user fee by the government. Most of the analysis is conducted for general production functions consistent with endogenous growth, although the case of CES technology is also considered.

Siehe Inhaltsangabe der Diplomarbeit!

The aim of these lecture notes is to give a quick introduction into neural networks, its algorithms and applications. The notes are not intended as a replacement of a comprehensive textbook.

Combinatorial optimization is still one of the biggest mathematical challenges if you plan and organize the run-ning of a business. Especially if you organize potential factors or plan the scheduling and sequencing of opera-tions you will often be confronted with large-scaled combinatorial optimization problems. Furthermore it is very difficult to find global optima within legitimate time limits, because the computational effort of such problems rises exponentially with the problem size. Nowadays several approximation algorithms exist that are able to solve this kind of problems satisfactory. These algorithms belong to a special group of solution methods which are called local search algorithms. This article will introduce the topic of simulated annealing, one of the most efficient local search strategies. This article summarizes main aspects of the guest lecture Combinatorial Optimi-zation with Local Search Strategies, which was held at the University of Ioannina in Greece in June 1999.