Preparation of anti-vicinal amino alcohols: asymmetric synthesis of D-erythro-Sphinganine, (+)-spisulosine and D-ribo-phytosphingosine

Two variations of the Overman rearrangement have been developed for the highly selective synthesis of anti-vicinal amino alcohol natural products. A MOM-ether directed palladium(II)-catalyzed rearrangement of an allylic trichloroacetimidate was used as the key step for the preparation of the protein kinase C inhibitor D-erythro-sphinganine and the antitumor agent (+)-spisulosine, while the Overman rearrangement of chiral allylic trichloroacetimidates generated by asymmetric reduction of an alpha,beta-unsaturated methyl ketone allowed rapid access to both D-ribo-phytosphingosine and L-arabino-phytosphingosine

The HERMES Spectrometer

The HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of Il, D, and He-3. These data give information on the spin structure of the nucleon. This paper describes the forward angle spectrometer built for this purpose. The spectrometer includes numerous tracking chambers (micro-strip gas chambers, drift and proportional chambers) in front of and behind a 1.3 T.m magnetic field, as well as an extensive set of detectors for particle identification (a lead-glass calorimeter, a pre-shower detector, a transition radiation detector, and a threshold Cherenkov detector). Two of the main features of the spectrometer are its good acceptance and identification of both positrons and hadrons, in particular pions. These characteristics, together with the purity of the targets, are allowing HERMES to make unique contributions to the understanding of how the spins of the quarks contribute to the spin of the nucleon. (C) 1998 Elsevier Science B.V. All rights reserved

SME 4.0: The Role of Small- and Medium-Sized Enterprises in the Digital Transformation

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Wskaźniki w centralizacji i decentralizacji organizacji

Continual improvement of business processes requires, apart from other efforts, to develop effective metrics, by which managers and/or process engineers will be able to manage the organization's growth. Obviously, there are plenty measures that can be taken to optimize processes. Once effective metrics are identified, the assessment team should do what works best for them. In this paper, an organizational “centralization” or “decentralization” is a matter of interest. The dichotomous term “centralization/decentralization” itself is somewhat inappropriate in the sense that an organizational centralization is not a goal, but rather a means to help us plan and to set goals. Naturally, approaches to the “centralization/ decentralization” measures depend on many factors. The paper's scope is explicitly limited to the vertical decentralization that is concerned with the delegation of decision-making power down the chain of authority. Subsequently, we are also interested to explore network centralization issues.Ciągłe doskonalenie procesów biznesowych wymaga, oprócz innych działań, opracowania skutecznych wskaźników, dzięki którym menedżerowie i / lub technolodzy będą mogli zarządzać rozwojem organizacji. Oczywiście, istnieje wiele działań, które mogą zostać podjęte w celu optymalizacji procesów. Kiedy oznaczone są skuteczne wskaźniki, zespół oceniający powinien robić to, co jest dla nich najlepsze. W niniejszym artykule przedmiotem zainteresowania jest organizacyjna "centralizacja" lub "decentralizacja". Dychotomiczne pojęcie "centralizacja / decentralizacja" samo w sobie jest nieco niestosowne w tym sensie, że centralizacja organizacyjna nie jest celem, lecz środkiem, aby pomóc nam planować i wyznaczać cele. Oczywiście podejścia do środków „centralizacji / decentralizacji" zależą od wielu czynników. Zakres artykułu jest wyraźnie ograniczony do decentralizacji pionowej, która dotyczy delegowania uprawnień decyzyjnych w dół łańcucha władzy. W późniejszym czasie, jesteśmy również zainteresowani zbadaniem kwestii centralizacji sieci

Modularity Measurement as a Crucial Design Element

Abstract This paper aims to explore the problem of measurement of assembly process modularity, and to offer a new approach to quantify the relative modularity of different assembly process models. Specifically, it seeks to resolve the problem of the relation between relative modularity measures and optimal modularity measures. This relation brings us more close to find an effective measure for determining whether the process network is optimally modular. In our approach, process modularity expresses the extent to which processes can be decomposed into modules to be executed in parallel, and/or in series. Moreover, it also considers important feature of modular systems - that the great majority of interactions occur within modules and only a few interactions occur between modules. Consequently, the effect of a change in a given module is confined to that module only. This advantage of modular design clearly corresponds with Axiomatic Design theory, especially with its first axiom.</jats:p

Structural Complexity of Assembly Supply Chains: A Theoretical Framework

AbstractIn this paper, we present a theoretical framework for modeling of assembly supply chains and propose three possible indicators to measure a structural complexity of assembly supply networks. Models of such networks are divided into classes on the basis of the numbers of initial suppliers. Subsequently, we compare proposed indicators and graphically demonstrate obtained results. Finally, pertinent finding of this research are summarized

Structural Complexity Assessment: A Design and Management Tool for Supply Chain Optimization

AbstractNowadays, competitiveness of supply chain companies is not just about optimizing supply chains within functions, but supply chains have to be optimized across functional elements as well. At this time, there are known several structural complexity indicators that have been validated for specific or/and generic supply chain models. Our intention in this paper is to test their ability to discern configuration dissimilarities between selected organizational concepts. The results of this theoretical study show that some of the indicators can be effectively used for identifying better configuration variant having feasible influence on organization performance while designing supply chain network