Anmerkungen zur Publikation „Möglichkeiten und Probleme des Einsatzes postalischer Befragungen“ von Karl-Heinz Reuband in der Kzfss 2001, 2, S. 307–333

Reuband’s article purports to report empirical results that seem to contradict the widely held view of mail surveys. This assertion is made possible only by an unclear statement of hypotheses and a selective perception of the literature. The data analysis is based on techniques from the 1960s and 1970s; modern methods are not even mentioned. Although all the results reported in the article are based on local surveys conducted by a university institute, these are generalized to national surveys in general. The main points of this critique are methodological: careless literature review, lack of concrete hypotheses, inefficient data analysis and generalizations without empirical foundation.     

René Königs beitrag zur Soziologie in Deutschland

Ohne Zusammenfassung Rede zum 100. Geburtstag auf einer Veranstaltung der Stadt K?ln, der René-K?nig-Gesellschaft und des Westdeutschen Rundfunks K?ln am 11. Mai 2006 in K?ln     

The web proxy location problem in general tree of rings networks

The Web proxy location problem in general networks is an NP-hard problem. In this paper, we study the problem in networks showing a general tree of rings topology. We improve the results of the tree case in literature and get an exact algorithm with time complexity O(nhk), where n is the number of nodes in the tree, h is the height of the tree (the server is in the root of the tree), and k is the number of web proxies to be placed in the net. For the case of networks with a general tree of rings topology we present an exact algorithm with O(kn ²) time complexity.This research has been supported by NSF of China (No. 10371028) and the Educational Department grant of Zhejiang Province (No. 20030622).     

Exclusion and vulnerability on public transit: experiences of transit dependent riders in Portland,Oregon

In urban areas, the inequitable distribution of transit systems and services has been shown to reproduce safety and environmental risks – potentially exacerbating preexisting inequities. Thus, how vulnerable populations access and utilize public transportation is of critical concern to urban scholars. This paper utilizes focus group data to explore how transit-dependent (particularly low-income) riders engage with the public transit system in Portland, Oregon. We illustrate specific ways in which transit-dependent riders experience marginalization and exclusion. We find that certain groups, particularly mothers with young children and those with disabilities are not well served by a public infrastructure oriented toward an ‘ideal rider’ who is an economically stable, able-bodied, white, male commuter. We conclude that a public infrastructure meant to serve all riders equitably, yet which fails to consider the unique experiences of marginalized transit users risks further amplifying existing social vulnerabilities and reinforcing gender, racial, and class inequalities.     

Picking Winners? Evidence on NATO’s Enlargement Strategy

The effectiveness of NATO conditionality for institutional reforms is highly controversial. Some papers argue that any effect this conditionality might have had may be due to endogeneity effects, i.e. NATO may have picked the winners. We argue that this is not the case. First, NATO-Mazedonia relations provide a case in point. Macedonia was granted entry into the Membership Action Plan (MAP) in 1999 due to country’s strategic importance. Only after the Ohrid agreement, effective conditionality set in and marked a switch in NATO strategy from security only towards institution building. Second, this is supported by econometric evidence based on panel data. An event study reveals that entry into NATO’s accession process was mainly driven by neighbourhood and good relations with the West. We conclude that empirical evidence clearly supports a stronger role of NATO’s political agenda, i.e., low entry barriers but strict accession conditionality.     

Modellgestützte Flexibilitätsanalyse von Strategien zur Ersatzteilversorgung in der Nachserienphase

An important task in after sales service is the provision of spare parts for durables. Due to its nature and dependence on earlier sales, the demand for spare parts is inherently dynamic and uncertain requiring for high procurement flexibility. During the product life cycle, inventory management of spare parts is performed efficiently under use of flexibility provided by existing production facilities. This situation completely changes once the OEM ceases production of the parent product. A prime option of procuring spare parts for the End-of-production period is to place a final order for parts when regular production ends. Besides low unit production costs, this option does not contain any flexibility, yielding a high risk of obsolescence of stored parts, and at the same time a high risk of not being able to satisfy all demand during the service period. In order to increase flexibility further options like extra production at higher unit cost or remanufacturing of components taken from used products could be used. After introducing the problem and a basic quantitative model, we evaluate flexibility properties of strategies using different combinations of the above options. In doing so we distinguish between quantity, time, and stock related flexibility. In a comprehensive numerical study it is investigated to which extent flexibility properties of the different strategies can contribute to their economic profitability.     

Improving the use of self-generated identification codes

In panel studies on sensitive topics, respondent-generated identification codes are often used to link records across surveys. However, usually a substantial number of cases are lost due to the codes. These losses may cause biased estimates. Using more components and linking the codes by the Levenshtein string distance function will reduce the losses. In a simulation study and two field experiments, the proposed procedure outperforms the methods previously applied.     

Exploring Partial Order of European Countries

Partial Order Theory has been recently more and more employed in applied science to overcome the intrinsic disadvantage hidden in aggregation, if a multiple attribute system is available. Despite its numerous positive features, there are many practical cases where the interpretation of the partial order can be rather troublesome. In these cases the analysis of underlying dimensions could be useful to uncover particular data structures. The paper shows a way of addressing the problem with the help of an actual case study, which deals with European opinions on services of general interest. In particular, a partial order of countries is firstly provided and then a method to detect dimensions is discussed and applied. The analysis stems directly from the Partially Order Set (poset) and Lattice theory with particular references to dimension theory and Formal Concept Analysis. The study is eventually able to pinpoint role and relevance of different attributes characterizing EU countries which are used to define the partial order.