Estimating a retailer's base stock level: an optimal distribution center order forecast policy

Errors in order forecasts are a salient source of inefficiencies in retail supply chains. Many operational decisions made by suppliers hinge on order forecasts, which typically are based solely on either order or point-of-sale (POS) history. Using a discrete-time formulation, this research demonstrates that if a supplier knows that a retailer is using a base stock policy, it should use that knowledge to forecast the retailer's orders, even if the supplier does not know the base stock level and/or have access to POS data.     

Zur quantitativen Bestimmung von Blaus?ure in pflanzlichen und tierischen Geweben

Ohne Zusammenfassung     

Investigating inclusion complexes using quantum chemical methods

Quantum chemistry has firmly established itself as a reliable method for investigating present-day problems in biological and materials chemistry. Understanding inclusion complexes represents one of the cutting edges of simulation sciences. In this tutorial review, we focus on the role and composition of non-covalent interactions, which are essential when studying inclusion complexes. A selected set of recently developed pragmatic methods used to study inclusion complexes are then surveyed including e.g. dispersion corrected DFT, double-hybrid functionals and spin-component scaled MP2. Finally, three case studies are outlined: (a) endohedral fullerene complexes, (b) buckyball catcher and (c) resorcinarene capsule. These case studies were carefully chosen to help illustrate how one may accurately investigate inclusion complexes, at a modest computational cost, using state-of-the-art quantum chemical methods (67 references).     

Predicting retailer orders with POS and order data: The inventory balance effect

Despite advances in retail point-of-sale (POS) data sharing, retailers’ suppliers struggle to effectively use POS data to improve their fulfillment planning processes. The challenge lies in predicting retailer orders. We present evidence that retail echelon inventory processes translate into a long-run balance or equilibrium between orders and POS, which we refer to as the inventory balance effect, allowing for more accurate order forecasting. Based on the inventory balance effect, this research prescribes a forecasting approach which simultaneously uses both sources of information (retailer order history and POS data) to predict retailer orders to suppliers. Using data from a consumable product category, this approach is shown to outperform approaches based singularly on order or POS data, by up to 125%. The strength of this novel approach – significantly improved forecast accuracy with minimal additional analysis – make it a candidate for widespread adoption in retail supply chain collaborative planning and forecasting initiatives with corresponding impact on fulfillment performance and related operating costs.     

The development of a thermal neutron activation (TNA) system as a confirmatory non-metallic land mine detector

In order to detect and locate buried landmines for peacekeeping, the Canadian Department of National Defence (DND), under the Improved Landmine Detection Project, is developing a vehicle-mounted, two-phase mine detection system. The first phase constitutes a suite of detectors used to indicate the possibility of a mine at a particular location (to ±30 cm in accuracy). In the second phase a Thermal Neutron Activation (TNA) system is used to confirm the presence of explosives via detection of the 10.83 MeV gamma-ray associated with nitrogen decay. The TNA system developed for this uses a 100 μg²⁵²Cf neutron source surrounded by four 3″×3″ NaI(Tl) detectors. Combining the use of state-of-the art radiation transport codes for design, judicious choice of specialized shielding materials and development of high-rate, fast-pulse processing electronics, has led to a system which can; (i) confirm the presence of all surface- or lightly-buried anti-tank mines in a few seconds to a minute (depending on mass of explosive), (ii) confirm the presence of anti-tank mines down to 20 cm depth in less than 5 minutes, (iii) confirm the presence of large (>100 g nitrogen) anti-personnel mines in less than five minutes, (iv) operate in adverse climatic conditions. These results have been verified in field trials and the system is due to be fielded in 1999.     

Recent advances in molecular diversity

Molecular Diversity -     

A small molecule that induces assembly of a four way DNA junction at low temperature

Small molecules that induce the formation of higher order DNA structures have potential therapeutic and nanotechnology applications. Screening of a click library has identified the first compound to induce the formation of a Holliday junction structure at room temperature without the need for a high temperature annealing step.     

Structures of trimetallic molybdenum and tungsten suboxide cluster anions

Anion photoelectron spectra of Mo(3)O(y)(-) and W(3)O(y)(-) (y = 3-6) are reported and analyzed using density functional theory results in an attempt to determine whether electronic and structural trends in the less oxidized clusters (y = 3, 4) could elucidate the disparate chemical properties of the M(3)O(y)(-) (M = Mo, W, y = 5, 6) species. In general, cyclic structures are calculated to be more stable by at least 1 eV than extended structures, and the lowest energy structures calculated for the most reduced species favor M = O terminal bonds. While the numerous low-energy structures found for Mo(3)O(y)(-)/Mo(3)O(y) and W(3)O(y)(-)/W(3)O(y) were, in general, similar, various structures of W(3)O(y)(-)/W(3)O(y) were found to be energetically closer lying than analogous structures of Mo(3)O(y)(-)/Mo(3)O(y). Additionally, the Mo-O-Mo bridge bond was found to be a more stabilizing structural motif than the W-O-W bridge bond, with the oxygen center in the former having the highest negative charge. Based on this, the observation of trapped intermediates in reactions between Mo(3)O(y)(-) and water or CO(2) that are not observed in analogous W(3)O(y)(-) reactivity studies may be partially attributed to the role of bridge bond fluxionality.     

Modelling of Technical Systems: Application to Hydrodynamic Torque Converters and Couplings

First a short survey of modelling of technical systems is presented. The different methods of modelling are applied to hydrodynamic torque converters and couplings. The results of linear modelling around an operating point, of nonlinear modelling for larger operating areas and of hybrid modelling using simplified physical laws are illustrated. Simulations for large excitations show the validity of the models. The advantages and disadvantages of the different methods are discussed.     

Investigation of internal radionuclide contamination from the analysis of nasal swabs and facial swipes

Nasal swabs and facial swipes have been used to screen potential internal radioactive contamination for decades. However, the ratio between the lung intake and the activity on a swab or a swipe varies according to the nature of the contaminant involved and the exposure conditions such as particle sizes of the contaminant and the humidity in the air. This paper reports the experimental results using stable La₂O₃ as an analog for actinide oxides, focusing on the most important parameters such as humidity, plume velocity, and facial condition at a fixed room temperature of 23 ± 2 °C. The results showed that the effects of humidity, plume velocity, and facial condition vary more on orofacial swipe/lung deposition ratios compared to nasal swab/lung deposition ratios. The amounts on nasal swabs tended to show smaller change with respect to parameters such as plume velocity, humidity, and skin moisture. The amounts on orofacial swipes varied by a factor of 10–15 among the samples collected across all parameters. Such variability would be expected to be even greater in a real-world scenario with a larger range of physiological and environmental conditions.