Effects of distribution planning systems on the cost of delivery in unique make-to-order manufacturing

This thesis investigates the effects of simulation through the use of a distribution planning system (DPS) on distribution costs in the setting of unique make-to-order manufacturers (UMTO). In doing so, the German kitchen furniture industry (GKFI) serves as an example and supplier of primary data. On the basis of a detailed market analysis this thesis will demonstrate that this industry, which mostly works with its own vehicles for transport, is in urgent need of innovative logistics strategies. Within the scope of an investigation into the current practical and theoretical use of DPS, it will become apparent that most known DPS are based on the application of given or set delivery tour constraints. Those constraints are often not questioned in practice and in theory nor even attempted to be omitted, but are accepted in day-to-day operation. This paper applies a different approach. In the context of this research, a practically applied DPS is used supportively for the removal of time window constraints (TWC) in UMTO delivery. The same DPS is used in ceteris paribus condition for the re-routing of deliveries and hereby supports the findings regarding the costliness of TWC. From this experiment emerges an overall cost saving of 50.9% and a 43.5% reduction of kilometres travelled. The applied experimental research methodology and the significance of the resulting savings deliver the opportunity to analyse the removal of delivery time window restrictions as one of many constraints in distribution logistics. The economic results of this thesis may become the basis of discussion for further research based on the applied methodology. From a practical point of view, the contributions to new knowledge are the cost savings versus the change of demand for the setting of TWC between the receiver of goods and the UMTO supplier. On the side of theoretical knowledge, this thesis contributes to filling the gap on the production – distribution problem from a UMTO perspective. Further contributions to knowledge are delivered through the experimental methodology with the application of a DPS for research in logistics simulation

Measuring overeducation with earnings frontiers and multiply imputed censored income data

"In this paper, we remove one serious drawback of the IAB employment sample impeding its applicability to the estimation of earnings frontiers: the censoring of the income data, by multiple imputation. Then, we estimate individual potential income with stochastic earnings frontiers, and we measure overeducation as the ratio between actual income and potential income. It is shown that the measurement of overeducation by this income ratio is a valuable addition to the overeducation literature because the well-established objective or subjective overeducation measures focus on some ordinal matching aspects and ignore the metric income and efficiency aspects of overeducation." (Author's abstract, IAB-Doku) ((en))Überqualifikation - Messung, Einkommen, Einkommenshöhe, IAB-Beschäftigtenstichprobe, Stichprobenfehler, Datenaufbereitung, Datenanalyse, Schätzung, Imputationsverfahren

Expensive and low-price places to live : regional price levels and the agglomeration wage differential in Western Germany

"Recently, there has been a renewed interest in the agglomeration wage differential. One of the open research question is whether wage differences between large cities and the rural country are due to unobserved differences in regional price levels. In this paper information on regional price levels for western German regions is used to assess this wage differential. Since for many regions price information is not available. Multiple Imputation is used to generate completed data sets. It can be shown that this strategy is more reliable than simply using predictions of regression analysis. The results obtained show that the agglomeration wage differential in Germany is smaller than in the US, and that only a minor part of it can be explained by differences in prices." (Author's abstract, IAB-Doku) ((en))Lohnunterschied, regionale Disparität, Preisniveau, Westdeutschland, Bundesrepublik Deutschland

Measuring overeducation with earnings frontiers and multiply imputed censored income data

"In this paper, we remove one serious drawback of the IAB employment sample impeding its applicability to the estimation of earnings frontiers: the censoring of the income data, by multiple imputation. Then, we estimate individual potential income with stochastic earnings frontiers, and we measure overeducation as the ratio between actual income and potential income. It is shown that the measurement of overeducation by this income ratio is a valuable addition to the overeducation literature because the well-established objective or subjective overeducation measures focus on some ordinal matching aspects and ignore the metric income and efficiency aspects of overeducation." (author's abstract)In dem Papier wird ein ernstzunehmender Nachteil der IAB-Beschäftigtenstichprobe beseitigt, der die Nutzung dieser Stichprobe zur Schätzung von Einkommensgrenzen verhinderte: zensierte Einkommensdaten werden durch multiple Imputation ergänzt. Anschließend werden die individuellen Einkommenspotentiale mittels stochastischer Einkommens-Grenzfunktion geschätzt, und die Überqualifikation wird als Verhältnis von aktuellem und potenziellem Einkommen bestimmt. Es wird gezeigt, das dieser Ansatz einen nützlichen Beitrag zur Literatur über Überqualifikation darstellt, weil dabei im Unterschied zu üblichen Messungen, die sich auf ordinale Matching-Aspekte konzentrieren, die Einkommens- und Effizienz-Effekte von Überqualifikation berücksichtigt werden. (IAB

“\u3ci\u3eAgrionemys kazachstanica terbishi\u3c/i\u3e” or the Two-Faced Mongolian Steppe Tortoise

Although no extant native turtle and tortoise species is known to occur in Mongolia, a new subspecies of the Central Asian tortoise was described by Chkhikvadze under the name Agrionemys kazachstanica terbishi in 2009. The description was based on a mummified tortoise kept in a museum collection. Since then the Mongolian steppe tortoise has been considered as an endemic taxon Testudo horsfieldii terbishi (Chkhikvadze, 2009) for Mongolia. However, there is no evidence for the occurrence of any wild tortoise species in Mongolia, even in the putative area of origin of the type specimen. The closest confirmed occurrence of Central Asian steppe tortoises is about 500 km away from Mongolia. Moreover, since 2010 the type specimen disappeared from the museum collection. Yet, there are several clues that the specimen in question was brought from Kazakhstan about 10 years ago to live as a pet in a yurt of a Mongolian nomadic family. Therefore, the recently described subspecies should be regarded as a “nomen dubium” and T. horsfieldii should be deleted from the faunal list of Mongolia

Indexed and Fibred Structures for Hoare Logic

Indexed and fibred categorical concepts are widely used in computer science as models of logical systems and type theories. Here we focus on Hoare logic and show that a comprehensive categorical analysis of its axiomatic semantics needs the languages of indexed category and fibred category theory. The structural features of the language are presented in an indexed setting, while the logical features of deduction are modeled in the fibred one. Especially, Hoare triples arise naturally as special arrows in a fibred category over a syntactic category of programs, while deduction in the Hoare calculus can be characterized categorically by the heuristic deduction = generation of cartesian arrows + composition of arrows.publishedVersio

“\u3ci\u3eAgrionemys kazachstanica terbishi\u3c/i\u3e” or the Two-Faced Mongolian Steppe Tortoise

Although no extant native turtle and tortoise species is known to occur in Mongolia, a new subspecies of the Central Asian tortoise was described by Chkhikvadze under the name Agrionemys kazachstanica terbishi in 2009. The description was based on a mummified tortoise kept in a museum collection. Since then the Mongolian steppe tortoise has been considered as an endemic taxon Testudo horsfieldii terbishi (Chkhikvadze, 2009) for Mongolia. However, there is no evidence for the occurrence of any wild tortoise species in Mongolia, even in the putative area of origin of the type specimen. The closest confirmed occurrence of Central Asian steppe tortoises is about 500 km away from Mongolia. Moreover, since 2010 the type specimen disappeared from the museum collection. Yet, there are several clues that the specimen in question was brought from Kazakhstan about 10 years ago to live as a pet in a yurt of a Mongolian nomadic family. Therefore, the recently described subspecies should be regarded as a “nomen dubium” and T. horsfieldii should be deleted from the faunal list of Mongolia