Arbeitszufriedenheit und Energie

Focussing on energy as a highly activated affective state offers new opportunities to promote well-being at work and job performance. In this paper, I will describe current research on recovery, affective work events and characteristics of work tasks linked to energy. The practical implications for promoting energy at work are discussed.     

Lust an der Macht – Frauen in Organisationen

Storyline and analysis of the film “The Devil Wears Prada” provide vivid scenes to derive reflections on organisational culture in globalised companies and women in chief positions. Women come into conflict with leading the company successfully, the dependence on efficient – female – staff and the image as a woman. The article illustrates, how influences of the company’s products fashion und fashion market have a normative effect, especially on female staff members. Theories of organisational culture, careers of women and findings of gender research are shown in connection with complex strategies of women in their determination to succeed, to self-realization and the pressure to adapt oneself. This involves reflected perspectives to leave clichés of gender and to reinforce organisational and personal potentials.     

Determinants and effects of formal target agreements: an empirical investigation of German firms

We investigate organizational determinants and performance effects of formal target agreements for employees based on the IAB establishment panel, a representative panel of German establishments. The results show that establishments with a high employee turnover rate, a large proportion of temporary workers, and a highly qualified workforce are significantly more likely to implement target agreements. Also, establishments with works councils installed are more likely to do so, controlling, among others, for firm size. Concerning organizational performance, we apply a first-difference and a fixed effects approach and find that establishments that implement target agreements achieve around 5 % higher total sales compared to firms that did not introduce this practice. Hence, organizations seem to benefit from the implementation of formal target agreements for employees.     

Coaching von Schlaganfallpatienten Ein integratives Beratungs- und Trainingskonzept

Coaching of patients after apoplexy — an integrative model of counselling and trainingIn contrast to common assessments of medical professionals, improvements in rehabilitation of patients after an apoplexy are possible even after a greater time interval. The progresses are small, but they improve gradually the quality of life of the patients. The author presents an integrative model of counselling and training for this clientele, in order to accompany the way of the patients to a successful professional rehabilitation and to a new conduct of life.     

Sicherheitsäquivalente zur risikoadjustierten Bewertung: Unternehmensexterne Bewertungssicht vs. unternehmensinterne Steuerungssicht Replik zu den Anmerkungen „Zum Verhältnis von Wertadditivität bei Sicherheitsäquivalenten und Risikoanalyse“ von <Emphasis Type=Italic>Reichling et al.</Emphasis> (2008)

Die Forderung nach schwacher Wertadditivit?t von Sicherheits?quivalenten ist in Abh?ngigkeit des jeweiligen Bewertungszwecks zu diskutieren. W?hrend in der unternehmensexternen Bewertungssicht, z.B. bei der Unternehmensbewertung, die Forderung nach schwacher Wertadditivit?t gut begründbar ist, stellt sie im Bereich der unternehmensinternen Steuerungssicht eine „Nice to have“-Anforderung dar. Darüber hinaus werden in der bisherigen Literatur zur Anwendbarkeit von Sicherheits?quivalenten die Kernherausforderungen der unternehmensinternen Steuerung vernachl?ssigt. Insbesondere die ad?quate Berücksichtigung stochastischer Abh?ngigkeiten im Portfolioverbund bei der Bewertung von Einzelgesch?ften mittels Sicherheits?quivalenten stellt eine Forschungslücke dar.     

On the odd girth and the circular chromatic number of generalized Petersen graphs

A class \(\mathcal{G}\) of simple graphs is said to be girth-closed (odd-girth-closed) if for any positive integer g there exists a graph \(\mathrm {G} \in \mathcal{G}\) such that the girth (odd-girth) of \(\mathrm {G}\) is \(\ge g\). A girth-closed (odd-girth-closed) class \(\mathcal{G}\) of graphs is said to be pentagonal (odd-pentagonal) if there exists a positive integer \(g^*\) depending on \(\mathcal{G}\) such that any graph \(\mathrm {G} \in \mathcal{G}\) whose girth (odd-girth) is greater than \(g^*\) admits a homomorphism to the five cycle (i.e. is \(\mathrm {C}_{_{5}}\)-colourable). Although, the question “Is the class of simple 3-regular graphs pentagonal?” proposed by Ne?et?il (Taiwan J Math 3:381–423, 1999) is still a central open problem, Gebleh (Theorems and computations in circular colourings of graphs, 2007) has shown that there exists an odd-girth-closed subclass of simple 3-regular graphs which is not odd-pentagonal. In this article, motivated by the conjecture that the class of generalized Petersen graphs is odd-pentagonal, we show that finding the odd girth of generalized Petersen graphs can be transformed to an integer programming problem, and using the combinatorial and number theoretic properties of this problem, we explicitly compute the odd girth of such graphs, showing that the class is odd-girth-closed. Also, we obtain upper and lower bounds for the circular chromatic number of these graphs, and as a consequence, we show that the subclass containing generalized Petersen graphs \(\mathrm {Pet}(n,k)\) for which either k is even, n is odd and \(n\mathop {\equiv }\limits ^{k-1}\pm 2\) or both n and k are odd and \(n\ge 5k\) is odd-pentagonal. This in particular shows the existence of nontrivial odd-pentagonal subclasses of 3-regular simple graphs.     

The no-wait job shop with regular objective: a method based on optimal job insertion

The no-wait job shop problem (NWJS-R) considered here is a version of the job shop scheduling problem where, for any two operations of a job, a fixed time lag between their starting times is prescribed. Also, sequence-dependent set-up times between consecutive operations on a machine can be present. The problem consists in finding a schedule that minimizes a general regular objective function. We study the so-called optimal job insertion problem in the NWJS-R and prove that this problem is solvable in polynomial time by a very efficient algorithm, generalizing a result we obtained in the case of a makespan objective. We then propose a large neighborhood local search method for the NWJS-R based on the optimal job insertion algorithm and present extensive numerical results that compare favorably with current benchmarks when available.     

A lower bound for the adaptive two-echelon capacitated vehicle routing problem

Adaptive two-echelon capacitated vehicle routing problem (A2E-CVRP) proposed in this paper is a variant of the classical 2E-CVRP. Comparing to 2E-CVRP, A2E-CVRP has multiple depots and allows the vehicles to serve customers directly from the depots. Hence, it has more efficient solution and adapt to real-world environment. This paper gives a mathematical formulation for A2E-CVRP and derives a lower bound for it. The lower bound is used for deriving an upper bound subsequently, which is also an approximate solution of A2E-CVRP. Computational results on benchmark instances show that the A2E-CVRP outperforms the classical 2E-CVRP in the costs of routes.     

Optimal RSUs deployment with delay bound along highways in VANET

In order to broadcast an alert message from the accident site to the control center as soon as possible, the roadside units (RSUs) act as the critical component in vehicular ad hoc networks (VANETs). It is not possible to make a pervasive RSU deployment due to the huge cost and market requirement. Hence, how to deploy a minimum number of RSUs in a given region becomes a challenge problem. In this paper, we present an analysis for the total delay of broadcasting alert messages in VANETs along highways. Based on the analysis, the relationship between optimal number of RSUs with the highway distance is given. Moreover, the experiment results verifies the delay analysis and the optimization of RSUs deployment.     

Minimizing the number of tardy jobs in two-machine settings with common due date

We consider two-machine scheduling problems with job selection. We analyze first the two-machine open shop problem and provide a best possible linear time algorithm. Then, a best possible linear time algorithm is derived for the job selection problem on two unrelated parallel machines. We also show that an exact approach can be derived for both problems with complexity \(O(p(n) \times \sqrt{2}^n)\), p being a polynomial function of n.