9,672 research outputs found

    Selecting R&D Projects at BMW: A Case Study of Adopting Mathematical Programming Models

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    Research and development (R&D) project selection is a critical interface between the product development strategy of an organization and the process of managing projects day-to-day. This article describes the project selection problem faced by an R&D group of BMW (Munich, Germany). The problem was structured as minimizing the gap between target performance of the technology to be developed and actual performance of the current technology along chosen criteria. A mathematical programming model helped this organization to increase the transparency of their selection process, which previously had been based on experience coupled with evaluation of individual projects in isolation Implementation was a success in that the predevelopment group continues to use the model to make better decisions. However, the organization did not use the model for its intended purpose: constrained optimization. The traditional explanation for this partial implementation is that the analytical model did not capture all considerations relevant to optimization (e.g., uncertainty or strategic fit), and that further model refinements are required to achieve further implementation. We offer an alternative explanation, one based on the technology transfer literature. The diffusion of the analytical model from academia to industry faced the same problems as any technology transfer: Significant tacit knowledge had to be transferred along with the codified knowledge of the analytical model. This required iterated problem solving, which required the limited time and resources of the diffusing agents (academia) as well as the adopting agents (industry). Thus, the organization adopted only those elements of the modeling method that could be transferred within the resource constraints, focusing on those elements offering the highest benefit per effort invested

    Pulsed Quantum Frequency Combs from an Actively Mode-locked Intra-cavity Generation Scheme

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    We introduce an intra-cavity actively mode-locked excitation scheme for nonlinear microring resonators that removes the need for external laser excitation in the generation of pulsed two-photon frequency combs. We found a heralded anti-bunching dip of 0.245 and maximum coincidence-to-accidental ratio of 110 for the generated photon pairs

    Banning Commercial Foresting: What are the Costs?

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    The Philippines' forest cover has suffered from massive denudation through the years due to uncontrolled and indiscriminate commercial logging. Because of this, calls for a total logging ban had been raised in various fora, including in the legislature where bills that consider the possibility of a ban are being studied. However, the possible economic costs of such ban as espoused in some studies has delayed the passage of these bills. This Policy Notes provides some economic costing based on computations that may help in firming up decisions regarding the proposed ban.forestry sector, environmental issues, environmental management

    A Passively Mode-locked Nanosecond Laser with an Ultra-narrow Spectral Width

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    Many different mode-locking techniques have been realized in the past [1, 2], but mainly focused on increasing the spectral bandwidth to achieve ultra-short coherent light pulses with well below picosecond duration. In contrast, no mode-locked laser scheme has managed to generate Fourier-limited nanosecond long pulses, which feature narrow spectral bandwidths (~MHz regime) instrumental to applications in spectroscopy, efficient excitation of molecules, sensing, and quantum optics. The related limitations are mainly caused by the adverse operation timescales of saturable absorbers, as well as by the low strength of the nonlinear effects typically reachable through nanosecond pulses with manageable energies

    Weight Loss and Decrease of Body Mass Index during Allogeneic Stem Cell Transplantation Are Common Events with Limited Clinical Impact

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    Purpose Weight loss in cancer patients has been attributed with significant morbidity and mortality. During allogeneic stem cell transplantation (SCT),oral nutrition is often hampered and hence total parenteral nutrition (TPN) is necessary. We therefore investigated the course of weight during stem cell transplantation and the clinical consequences of weight change. Methods 180 consecutive patients who received allogeneic SCT between January 2010 and December 2011 at our center were analyzed for weight loss, laboratory and clinical parameters. Results During SCT, a median decrease of 6.6% of body mass index (BMI) was observed for the whole population (from 25.3 at admission to 23.6 at discharge),and a 1.6fold increase of malnutrition despite use of TPN (28.3% to 45.0%). 55.6% of patients experienced a significant weight loss of >= 5% with a median decrease of 9.2% in BMI. Serum levels of albumin, total protein and cholesterol rapidly decreased during conditioning therapy. After a median of 2.4 years, the median BMI was still only 23.4 (not different from discharge). However, we did not observe a meaningful difference in side effects and survival between patients that did or did not lose weight. Conclusion Weight loss is commonly observed during allogeneic SCT despite TPN, but the clinical consequences thereof seem limited: we observed no significant impact on patients with a decrease >= 5% in BMI on transplant outcome, side effects or survival
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