A quadratic time exact algorithm for continuous connected 2-facility location problem in trees

This paper studies the continuous connected 2-facility location problem (CC2FLP) in trees. Let \(T = (V, E, c, d, \ell , \mu )\) be an undirected rooted tree, where each node \(v \in V\) has a weight \(d(v) \ge 0\) denoting the demand amount of v as well as a weight \(\ell (v) \ge 0\) denoting the cost of opening a facility at v, and each edge \(e \in E\) has a weight \(c(e) \ge 0\) denoting the cost on e and is associated with a function \(\mu (e,t) \ge 0\) denoting the cost of opening a facility at a point x(e, t) on e where t is a continuous variable on e. Given a subset \(\mathcal {D} \subseteq V\) of clients, and a subset \(\mathcal {F} \subseteq \mathcal {P}(T)\) of continuum points admitting facilities where \(\mathcal {P}(T)\) is the set of all the points on edges of T, when two facilities are installed at a pair of continuum points \(x_1\) and \(x_2\) in \(\mathcal {F}\), the total cost involved in CC2FLP includes three parts: the cost of opening two facilities at \(x_1\) and \(x_2\), K times the cost of connecting \(x_1\) and \(x_2\), and the cost of all the clients in \(\mathcal {D}\) connecting to some facility. The objective is to open two facilities at a pair of continuum points in \(\mathcal {F}\) to minimize the total cost, for a given input parameter \(K \ge 1\). This paper focuses on the case of \(\mathcal {D} = V\) and \(\mathcal {F} = \mathcal {P}(T)\). We first study the discrete version of CC2FLP, named the discrete connected 2-facility location problem (DC2FLP), where two facilities are restricted to the nodes of T, and devise a quadratic time edge-splitting algorithm for DC2FLP. Furthermore, we prove that CC2FLP is almost equivalent to DC2FLP in trees, and develop a quadratic time exact algorithm based on the edge-splitting algorithm. Finally, we adapt our algorithms to the general case of \(\mathcal {D} \subseteq V\) and \(\mathcal {F} \subseteq \mathcal {P}(T)\).     

Performance management change in archaeological sites: The case of Herculaneum Conservation Project

This study focuses on the issues relating to the implementation of management accounting systems in complex settings such as archeological sites. The aim is to understand the conditions under which the implementation of performance management systems (PMS) may enable cultural organizations to fulfil their multiple objectives and the factors which play a crucial role in such dynamics. Focusing on the Herculaneum Conservation Project (HCP) the study explains how PMS came to be implemented having been made acceptable to all parties involved. The Middle Range Theory as developed by Broadbent and Laughlin (Accounting control and controlling accounting: interdisciplinary and critical perspectives, Bingley, Emerald, 2013) was utilized to explore how the PMS change took place in the HCP, and focus on the factors influencing this process. The findings reveal that the change in the PMS benefited from the involvement of a multidisciplinary Specialist Work Group. This involvement reduced the natural tendency to resist the forces of change and increased the commitment of the various groups of stakeholders to the new culture. The findings reveal how PMS were developed in the context of a multifaceted approach to change, allowing us to draw both theoretical and practical lessons that may be brought to bear in other complex contexts.     

On computing a minimum secure dominating set in block graphs

In a graph \(G=(V,E)\), a set \(D \subseteq V\) is said to be a dominating set of G if for every vertex \(u\in V{\setminus }D\), there exists a vertex \(v\in D\) such that \(uv\in E\). A secure dominating set of the graph G is a dominating set D of G such that for every \(u\in V{\setminus }D\), there exists a vertex \(v\in D\) such that \(uv\in E\) and \((D{\setminus }\{v\})\cup \{u\}\) is a dominating set of G. Given a graph G and a positive integer k, the secure domination problem is to decide whether G has a secure dominating set of cardinality at most k. The secure domination problem has been shown to be NP-complete for chordal graphs via split graphs and for bipartite graphs. In Liu et al. (in: Proceedings of 27th workshop on combinatorial mathematics and computation theory, 2010), it is asked to find a polynomial time algorithm for computing a minimum secure dominating set in a block graph. In this paper, we answer this by presenting a linear time algorithm to compute a minimum secure dominating set in block graphs. We then strengthen the known NP-completeness of the secure domination problem by showing that the secure domination problem is NP-complete for undirected path graphs and chordal bipartite graphs.     

The role of weighting in corporate governance ratings

This methodological paper highlights the differences and the resulting implications from the application of the three most commonly applied weighting index methods to measuring corporate governance quality at an aggregate level: the Dichotomous; the partial compliance (PC) unweighted; and the Experts’ methods. In particular, first, we demonstrate how each method is applied and provide the details needed for readers to replicate each method. Second, we employ these methods on a sample of companies and compare the corresponding scores by testing their differences statistically. Third, as an indicative example of the potential implications arising from the use of these measures, we test whether the relation between market value and corporate governance levels differs, depending on the method applied. We find that the three methods produce significantly different overall and relative (i.e., ranking order) scores and, consequently, the relation between market value and corporate governance levels differs, depending on the method applied. Thus, we contribute to the corporate governance literature by showing that weighting in corporate governance indices matters and we recommend simultaneous application of at least two methods (i.e., the PC unweighted and the Experts’ methods) for deriving robust findings.     

Subset sum problems with digraph constraints

We introduce and study optimization problems which are related to the well-known Subset Sum problem. In each new problem, a node-weighted digraph is given and one has to select a subset of vertices whose total weight does not exceed a given budget. Some additional constraints called digraph constraints and maximality need to be satisfied. The digraph constraint imposes that a node must belong to the solution if at least one of its predecessors is in the solution. An alternative of this constraint says that a node must belong to the solution if all its predecessors are in the solution. The maximality constraint ensures that no superset of a feasible solution is also feasible. The combination of these constraints provides four problems. We study their complexity and present some approximation results according to the type of input digraph, such as directed acyclic graphs and oriented trees.     

Testing Herzberg’s Two-Factor Theory of Motivation in the Public Sector: Is it Applicable to Public Managers?

Given the limitations in providing monetary rewards as an incentive in the public sector, Herzberg’s Two-Factor Theory of Motivation can be promising if it is applicable to public employees. This study identifies the effects of motivators and hygiene factors on public managers’ job satisfaction, and finds out if there is difference, compared to how private-sector employees are motivated. According to the findings, a majority of identified motivators in the previous research showed positive effects on job satisfaction among public managers, and public managers’ job satisfaction was not affected by hygiene factor as predicted in Herzberg’s study. Managerial implications are discussed.     

The Use of the Partnering Concept for Public–Private Collaboration: How Well Does it Really Work?

This paper critically scrutinizes the key success factors and tools described in the partnering literature by exploring how they are implemented in a public–private partnering collaboration. In addition to this the paper investigates to what extent these tools facilitate the relationship between the parties in a partnering process. The empirical data consist of two longitudinal case studies. Both cases are large and complex urban development projects in the Swedish water and sewage industry. The results from the cases were ambiguous and positive; as well, some negative outcomes were present. Further, the processes were in both cases far from easy and it required a lot of effort from the parties in the collaboration to make the collaboration work and establish a culture based on trust, especially higher up in the organization. As could be expected, the reality is thus far more complex and cumbersome than previous studies indicate.     

Can Private Donations Help Public Universities Build Bridges Over Troubled Waters?: Practical Lessons for Administrators and Donors

With decreasing appropriations, some public organizations seek donations, often from large donors who may want to generate a return on investment by transforming the institution. As such, an interesting question emerges about institutions’ ability to meet donors’ expectations. Long fundraising histories, combined with a political and decentralized nature, make state universities an interesting venue to study the use of donations to create institutional change. Based on two single-state case studies, this research argues that real and perceived organizational barriers must be overcome. It concludes with implications for both administrator and donors.     

Interkulturelles Coaching – eine komplexe,systemische Herausforderung

Intercultural coaching takes place in the highly complex reality of a globalized world. The coachee is an individual acting in the situational context of his assignment and his corporate culture. He has been socialized in his own culture, but is communicating and interacting with people who have been socialized in different cultures. In order to identify and solve problems, all three aspects (person, situation, culture) have to be considered. Some aspects may have more influence than others may, but they combine in a closely interwoven system. The authors outline the theoretical background of intercultural coaching and illustrate the process with case studies.     

Bollwerk Zivilgesellschaft? Der Drang zum Extremen und Fanatismus in diesen unsicheren Zeiten

International studies show that the globalization and liberalization of modern societies often are experienced as a profound self-confusion. As an answer to these fundamental attacks on their self-esteem, many people develop extreme belief systems, which help them to regain self-confidence and self-assurance. Based on two examples of radicalization – xenophobia and veganism- some underlying psychological processes are discussed. As some consequences of radicalization for societies can be expected, e.?g. a strong hostile social polarization, a growing incompetence to adjust to a world of permanent change, or the total refusal to engage in dialogue. However, some hope offers the civil society in their resolute concountering radicalism to defend the virtues of democracy.