1,367 research outputs found
Modeling And Optimization Of Non-Profit Hospital Call Centers With Service Blending
This dissertation focuses on the operations problems in non-profit hospital call centers with inbound and outbound calls service blending.
First, the routing policy for inbound and outbound calls is considered. The objective is to improve the system utilization under constraints of service quality and operators\u27 quantity. A collection of practical staffing assignment methods, separating and mixing staffing policy are evaluated. Erlang C queuing model is used to decide the minimum number of operators required by inbound calls. Theoretical analysis and numerical experiments illustrate that through dynamically assigning the inbound and outbound calls to operators under optimal threshold policy, mixing staffing policy is efficient to balance the system utilization and service quality. Numerical experiments based on real-life data demonstrate how this method can be applied in practice.
Second, we study the staffing shift planning problem based on the inbound and outbound calls routing policies. A mathematical programming model is developed, based on a hospital call center with one kind of inbound calls and multiple kinds of outbound calls. The objective is to minimize the staffing numbers, by deciding the shift setting and workload allocation. The inbound calls service level and staffing utilization are taken into consideration in the constraints. Numerical experiments based on actual operational data are included. Results show that the model is effective to optimize the shift planning and hence reduce the call centers\u27 cost.
Third, we model the staffing shift planning problem for a hospital call center with two kinds of service lines. Each kind of service is delivered through both inbound calls and outbound calls. The inbound calls can be transferred between these two service lines. A mathematical programming model is developed. The objective is to minimize the staffing cost, by deciding the shift setting and workload allocation. The inbound calls service level and staffing utilization are taken into consideration in the constraints. Numerical experiments are carried out based on actual operational data. Results show that the model is effective to reduce the call centers\u27 labor cost
Electrical Transport Properties of Multilayered Single-Walled Carbon Nanotube Films
An improved layer-by-layer vacuum filtration method was adopted for the fabrication of single-walled carbon nanotube (SWCNT) films aiming at a series of SWCNT films with controllable thickness and density. The electrical transport properties of the multilayered SWCNT films have been investigated. With the constant film density, the decrease of the layer number of the SWCNT film results in an increase of the temperature coefficient of resistance (TCR). SWCNT film with 95% metallic nanotubes has shown a lower TCR than that of the SWCNT films with a low percentage of metallic nanotubes. The effect of thermal annealing and subsequent acid (HNO3) treatment on the electrical properties of the SWCNT films has also been investigated
Investigation of nedaplatin and CpG oligodeoxynucleotide combination therapy in a mouse model of lung cancer
Purpose: To investigate the anti-tumor effects of nedaplatin (NDP) and CpG oligodeoxynucleotide (CpG-ODN) combination therapy in a mouse-modeled lung cancer.Methods: To evaluate the anti-tumor effects of NDP and CpG-ODN combination therapy, a lung cancer xenograft mouse model was established by subcutaneous injection of LA-795 cells. BALB/c mice were divided into four groups as follows: NDP, CpG-, NDP + CpG-ODN and untreated control group. The sections of lung cancer tissue were stained with hematoxylin and eosin (H&E) and morphologically examined. Spleen, body weight, and spleen index were measured. Flow cytometry was used to determine the proportions of CD3+, CD8+, CD4+ and CD4+/CD8+ in mice blood cells. Serum levels of interferon-γ (IFN-γ) and interleukin-12 (IL-12) were measured by enzyme-linked immunosorbent assay (ELISA).Results: NDP + CpG-ODN therapy significantly reduced tumor volume and prolonged the survival time of tumor-bearing mice. NDP + CpG-ODN induced a change in cancer cell morphology, including large areas of necrosis which correlated with a reduction in tumor size. NDP + CpG-ODN significantly increased spleen weight/index and dramatically enhanced immune cell activation. This was evident in the increase serum levels of IFN-γ and IL-12.Conclusion: NDP and CpG-ODN combination therapy inhibits the growth of lung cancer and prolongs the survival time of tumor-bearing mice. This may result from the activation of immune cells and increased expression of IFN-γ and IL-12.Keywords: CpG ODN, NDP, Lung cancer, Combination therap
Integration on acceleration signals by adjusting with envelopes
Direct integration of acceleration often causes unrealistic drifts in velocity and displacement. A method of integration on acceleration data to acquire realistic velocity and displacement is proposed. In this approach, drifts are estimated by using the mean of the upper and lower envelopes of signals after integration from acceleration into velocity and displacement. The experimental results obtained by using simulated data and real world signals are presented to demonstrate the effectiveness of the method
Fractional Order Stochastic Differential Equation with Application in European Option Pricing
Memory effect is an important phenomenon in financial systems, and a number of research works have been carried out to study the long memory in the financial markets. In recent years, fractional order ordinary differential equation is used as an effective instrument for describing the memory effect in complex systems. In this paper, we establish a fractional order stochastic differential equation (FSDE) model to describe the effect of trend memory in financial pricing. We, then, derive a European option pricing formula based on the FSDE model and prove the existence of the trend memory (i.e., the mean value function) in the option pricing formula when the Hurst index is between 0.5 and 1. In addition, we make a comparison analysis between our proposed model, the classic Black-Scholes model, and the stochastic model with fractional Brownian motion. Numerical results suggest that our model leads to more accurate and lower standard deviation in the empirical study
Quantum Hydrodynamic Model by Moment Closure of Wigner Equation
In this paper, we derive the quantum hydrodynamics models based on the moment
closure of the Wigner equation. The moment expansion adopted is of the Grad
type firstly proposed in \cite{Grad}. The Grad's moment method was originally
developed for the Boltzmann equation. In \cite{Fan_new}, a regularization
method for the Grad's moment system of the Boltzmann equation was proposed to
achieve the globally hyperbolicity so that the local well-posedness of the
moment system is attained. With the moment expansion of the Wigner function,
the drift term in the Wigner equation has exactly the same moment
representation as in the Boltzmann equation, thus the regularization in
\cite{Fan_new} applies. The moment expansion of the nonlocal Wigner potential
term in the Wigner equation is turned to be a linear source term, which can
only induce very mild growth of the solution. As the result, the local
well-posedness of the regularized moment system for the Wigner equation remains
as for the Boltzmann equation
Semisynthetic Macrocyclic Lipo-lanthipeptides Display Antimicrobial Activity Against Bacterial Pathogens
[Image: see text] A large number of antimicrobial peptides depend on intramolecular disulfide bonds for their biological activity. However, the relative instability of disulfide bonds has limited the potential of some of these peptides to be developed into therapeutics. Conversely, peptides containing intramolecular (methyl)lanthionine-based bonds, lanthipeptides, are highly stable under a broader range of biological and physical conditions. Here, the class-II lanthipeptide synthetase CinM, from the cinnamycin gene cluster, was employed to create methyllanthionine stabilized analogues of disulfide-bond-containing antimicrobial peptides. The resulting analogues were subsequently modified in vitro by adding lipid tails of variable lengths through chemical addition. Finally, the created compounds were characterized by MIC tests against several relevant pathogens, killing assays, membrane permeability assays, and hemolysis assays. It was found that CinM could successfully install methyllanthionine bonds at the intended positions of the analogues and that the lipidated macrocyclic core peptides have bactericidal activity against tested Gram-positive and Gram-negative pathogenic bacteria. Additionally, fluorescence microscopy assays revealed that the lipidated compounds disrupt the bacterial membrane and lyse bacterial cells, hinting toward a potential mode of action. Notably, the semisynthesized macrocyclic lipo-lanthipeptides show low hemolytic activity. These results show that the methods developed here extend the toolbox for novel antimicrobial development and might enable the further development of novel compounds with killing activity against relevant pathogenic bacteria
A Meta-Analysis of Choroidal Thickness Changes in Unilateral Amblyopia
Purpose. To date, the topic of amblyopic changes remains controversial. Therefore, a systematic review and meta-analysis were carried out to evaluate choroidal changes in unilateral amblyopia. Methods. Major literature databases were searched for amblyopia-relevant studies. Using enhanced depth imaging optical coherence tomography (EDI-OCT), the primary outcome parameters examined were subfoveal choroidal thickness (SFCT) and different choroidal thickness (CT) positions. Efficacy estimates were evaluated by weighted mean difference (WMD) and 95% confidence interval (CI) for choroidal-associated changes. We performed subgroup analysis and metaregression analysis to examine potential sources of heterogeneity. Results. Eleven cross-sectional studies that included a total of 768 participants were identified. The amblyopic eye SFCT was thicker than that of the fellow and control (normal) eyes (WMDamblyopia versus fellow=49.24, 95% CI of 30.22 to 68.27, p<0.001; WMDamblyopia versus control=54.51, 95% CI of 32.17 to 76.85, p<0.001). There were no differences between the fellow and control eyes (WMD=13.81, 95% CI of 1.16 to 28.77, p=0.071). Subgroup and metaregression analyses indicated that the OCT type was the main source of heterogeneity. Conclusions. The CT in the amblyopic eyes was thicker than that in the fellow and control eyes
Mixed Quantum/Classical Method for Nonadiabatic Quantum Dynamics in Explicit Solvent Models: The ππ∗/nπ∗ Decay of Thymine in Water as a Test Case
We present a novel mixed quantum classical dynamical method to include solvent effects on internal conversion (IC) processes. All the solute degrees of freedom are represented by a wavepacket moving according to nonadiabatic quantum dynamics, while the motion of an explicit solvent model is described by an ensemble of classical trajectories. The mutual coupling of the solute and solvent dynamics is included within a mean-field framework and the quantum and classical equations of motions are solved simultaneously. As a test case we apply our method to the ultrafast ππ∗ → nπ∗ decay of thymine in water. Solvent dynamical response modifies IC yield already on the 50 fs time scale. This effect is due to water librational motions that stabilize the most populated state. Pure static disorder, that is, the existence of different solvent configurations when photoexcitation takes place, also has a remarkable impact on the dynamicsThe support of MIUR (PRIN 2010-2011 prot. 2010ERFKXL) is acknowledged. J.C. acknowledges the Fundacioń Ramoń Areces for funding his Postdoctoral position in Pisa and the fellowship provided by “Fundacioń Seńeca − Agencia de Ciencia y Tecnología de la Regioń de Murcia” through the “Saavedra-Fajardo” program (20028/SF/16). R.I. thanks the Université Paris-Saclay (Chaire d’Alembert No. 2016-10751). Y. L. acknowledges the financial support from the China Scholarship Council (CSC, No. 201506220064) and Y.L. and N. L. a generous grant of computer time from the Norwegian Programme for Supercomputing. N. L. also acknowledges the National Nature Science Foundation of China (Grant No. 21573129). The authors gratefully acknowledge G. Worth for making available the Quantics code and for useful discussion
Single Nucleotide Polymorphisms of MicroRNA Processing Machinery Genes and Outcome of Hepatocellular Carcinoma
MicroRNA (miRNA)-related single nucleotide polymorphisms (miR-SNPs) can affect cancer development, treatment efficacy and patients prognosis. We examined 6 miR-SNPs in miRNA processing machinery genes including exportin 5 (XPO5) (rs11077), Ran-GTPase (RAN) (rs14035), Dicer (rs3742330), Trinucleotide Repeat Containing 6B (TNRC6B) (rs9623117), GEMIN3 (rs197412), GEMIN4 (rs2740348) in 108 surgically resected HCC patients and evaluated the impact of these miR-SNPs on HCC outcome. Among the 6 SNPs, only the A/A genotype of rs11077 located in XPO5 3′UTR was identified to associated independently with worse survival in HCC patients by multivariate analysis with relative risk, 0.395; 95% CI, 0.167–0.933; p = 0.034. This is the first study reporting that polymorphisms related to miRSNPs have prognostic value in hepatocellular carcinoma and identify the A/A genotype of rs11077 SNP site located in XPO5 3′UTR can help to predict worse prognosis in patients
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