1,481 research outputs found

    Integrating PPC and Flat Fee Pricing Schemes to Optimize the Internal Search Engine Revenue in the Electronic Market

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    Currently, the predominant pricing plan for the search engine (SE) advertising services in a proprietary electronic market is a flat fee (FF) pricing. These services have faced the challenge of customer attrition recently since FF pricing results in the inequality of service surplus among subscribers. A more sustainable and profitable pricing model would be to distinguish advertising resources by providing an additional usage-based pricing for certain user groups to transfer the service surplus among subscribers. We conceive a hybrid model integrating Pay-Per-Click (PPC) pricing into FF pricing. This proposed scheme can offer an incentive-compatible mechanism to attract more subscribers by relieving the inequity of service surplus, and eventually result in the increasing revenue of service providers

    Zeroth-Order Alternating Gradient Descent Ascent Algorithms for a Class of Nonconvex-Nonconcave Minimax Problems

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    In this paper, we consider a class of nonconvex-nonconcave minimax problems, i.e., NC-PL minimax problems, whose objective functions satisfy the Polyak-\Lojasiewicz (PL) condition with respect to the inner variable. We propose a zeroth-order alternating gradient descent ascent (ZO-AGDA) algorithm and a zeroth-order variance reduced alternating gradient descent ascent (ZO-VRAGDA) algorithm for solving NC-PL minimax problem under the deterministic and the stochastic setting, respectively. The number of iterations to obtain an ϵ\epsilon-stationary point of ZO-AGDA and ZO-VRAGDA algorithm for solving NC-PL minimax problem is upper bounded by O(ε2)\mathcal{O}(\varepsilon^{-2}) and O(ε3)\mathcal{O}(\varepsilon^{-3}), respectively. To the best of our knowledge, they are the first two zeroth-order algorithms with the iteration complexity gurantee for solving NC-PL minimax problems

    Involvement of Indoleamine 2,3-Dioxygenase in Impairing Tumor-Infiltrating CD8+ T-Cell Functions in Esophageal Squamous Cell Carcinoma

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    The indoleamine 2,3-dioxygenase-(IDO-) mediated microenvironment plays an important role in tumor immune escape. However, the inhibitory effects of IDO on the CD8+ tumour-infiltrating lymphocytes (CD8+ TILs) in esophageal squamous cell carcinoma (ESCC) have not been clarified yet. Here, we found that the level of IDO expression in ESCC tumor specimens correlated with a reduction in the number of CD8+ TILs. Patients with high IDO expression and a low number of CD8+ TILs had significantly impaired overall survival time. IDO expression and functional enzyme activity in ESCC cell lines could be induced by IFNγ. When exposed to the milieu generated by IDO-expressing Eca109 cells, the CD8+ TILs were suppressed in proliferation, and their cytolytic functions against target tumor cells were lost. These results suggested that impairing CD8+ TIL functions by IDO expressed in ESCC possibly contributed to the finding that patients with higher IDO expression have more aggressive disease progression and shorter overall survival time

    Electrochemically primed functional redox mediator generator from the decomposition of solid state electrolyte.

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    Recent works into sulfide-type solid electrolyte materials have attracted much attention among the battery community. Specifically, the oxidative decomposition of phosphorus and sulfur based solid state electrolyte has been considered one of the main hurdles towards practical application. Here we demonstrate that this phenomenon can be leveraged when lithium thiophosphate is applied as an electrochemically "switched-on" functional redox mediator-generator for the activation of commercial bulk lithium sulfide at up to 70 wt.% lithium sulfide electrode content. X-ray adsorption near-edge spectroscopy coupled with electrochemical impedance spectroscopy and Raman indicate a catalytic effect of generated redox mediators on the first charge of lithium sulfide. In contrast to pre-solvated redox mediator species, this design decouples the lithium sulfide activation process from the constraints of low electrolyte content cell operation stemming from pre-solvated redox mediators. Reasonable performance is demonstrated at strict testing conditions
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