1,743 research outputs found
Optimal Structural Results for Assemble-to-Order Generalized M-Systmes
Cataloged from PDF version of article.We consider an assemble-to-order generalized M-system with multiple components and multiple products,
batch ordering of components, random lead times, and lost sales. We model the system as an in nite-horizon
Markov decision process and seek an optimal control policy, which speci es when a batch of components
should be produced and whether an arriving demand for each product should be satis ed. To facilitate
our analysis, we introduce new functional characterizations for convexity and submodularity with respect to
certain non-unitary directions. These help us characterize optimal inventory replenishment and allocation
policies under a mild condition on component batch sizes via a new type of policy: lattice-dependent base-stock
and lattice-dependent rationing
Intrinsic Metastabilities in the Charge Configuration of a Double Quantum Dot
We report a thermally activated metastability in a GaAs double quantum dot
exhibiting real-time charge switching in diamond shaped regions of the charge
stability diagram. Accidental charge traps and sensor back action are excluded
as the origin of the switching. We present an extension of the canonical double
dot theory based on an intrinsic, thermal electron exchange process through the
reservoirs, giving excellent agreement with the experiment. The electron spin
is randomized by the exchange process, thus facilitating fast, gate-controlled
spin initialization. At the same time, this process sets an intrinsic upper
limit to the spin relaxation time.Comment: 4 pages, 5 figures (color
Validation of a novel image-weighed technique for monitoring food intake and estimation of portion size in hospital settings:a pilot study
AbstractObjectiveOptimal nutrition for hospital patients is crucial and routine monitoring of patients’ nutrient intake is imperative. However, personalised monitoring and customised intervention using traditional methods is challenging and labour-intensive, consequently it is often neglected in hospital settings. The present pilot study aimed to examine the reliability and validity of the Dietary Intake Monitoring System (DIMS) against the weighed food method (WFM).DesignThe DIMS 2.0 is composed of an integrated digital camera, weighing scale, radio-frequency identification sensor and WIFI connection for real-time image and weight dietary data acquisition and analysis. The DIMS equipment was used to collect data for a paired set of meals both before and after meal consumption at lunchtime.SettingOdense University Hospital, Denmark.SubjectsPhotos and weights of seventeen patient meals were captured.ResultsThe results showed a significant correlation between DIMS and WFM for energy (r=0·99, P&lt;0·01) and protein intake (r=0·98, P&lt;0·01). Intraclass correlation coefficients (ICC) revealed a high degree of agreement among the four non-trained assessors for estimates of portion size of each food item before (0·88, P&lt;0·01) and after consumption (0·99, P&lt;0·01). The ICC for energy and protein intake were 0·99 (P&lt;0·01) and 0·99 (P&lt;0·01), respectively. Bland–Altman plots revealed no systematic bias.ConclusionsConsidering the huge benefits associated with routine monitoring, technological advances have made it possible to develop a novel, easy-to-use DIMS that, according to the findings, is a valid alternative for use in hospital settings.</jats:sec
GaAs Quantum Dot Thermometry Using Direct Transport and Charge Sensing
We present measurements of the electron temperature using gate defined
quantum dots formed in a GaAs 2D electron gas in both direct transport and
charge sensing mode. Decent agreement with the refrigerator temperature was
observed over a broad range of temperatures down to 10 mK. Upon cooling nuclear
demagnetization stages integrated into the sample wires below 1 mK, the device
electron temperature saturates, remaining close to 10 mK. The extreme
sensitivity of the thermometer to its environment as well as electronic noise
complicates temperature measurements but could potentially provide further
insight into the device characteristics. We discuss thermal coupling
mechanisms, address possible reasons for the temperature saturation and
delineate the prospects of further reducing the device electron temperature.Comment: 8 pages, 3 (color) figure
Transcriptional alterations under continuous or pulsatile dopaminergic treatment in dyskinetic rats
Continuous dopaminergic treatment is considered to prevent or delay the occurrence of dyskinesia in patients with Parkinson's disease (PD). Rotigotine is a non-ergolinic D3>D2>D1 dopamine-receptor agonist for the treatment of PD using a transdermal delivery system providing stable plasma levels. We aimed to investigate the differential influence on gene expression of pulsatile l-DOPA or rotigotine versus a continuous rotigotine treatment. The gene expression profile within the nigro-striatal system of unilateral 6-hydroxydopamine-lesioned rats was assessed in order to differentiate potential changes in gene expression following the various treatment using Affymetrix microarrays and quantitative RT-PCR. The expression of 15 genes in the substantia nigra and of 11 genes in the striatum was altered under pulsatile treatments inducing dyskinetic motor response, but was unchanged under continuous rotigotine treatment that did not cause dyskinetic motor response. The route of administration of a dopaminergic drug is important for the induction or prevention of motor abnormalities and adaptive gene expressions. The decline of neurotrophin-3 expression under pulsatile administration was considered of particular importanc
The Trofobiose Theory and organic agriculture: the active mobilization of nutrients and the use of rock powder as a tool for sustainability
Gigahertz pulse source by compression of mode-locked VECSEL pulses coherently broadened in the normal dispersion regime
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