Search

Quantity discount is a frequently adopted scheme that has not been explicitly investigated in logistics service procurement auctions. This paper focuses on a revised winner determination problem under quantity discounts and demand uncertainty for a fourth-party logistics (4PL) provider in a combinatorial reverse auction. To characterize our research problem, a two-stage stochastic nonlinear programming model is constructed. Inspired by the idea of sample average approximation (SAA), the nonlinear model is reformulated as a deterministic mixed integer linear programming model by using a linearization technique with superior expressions. Since the reformulation has a large number of decision variables and constraints, we integrate SAA with a dual decomposition Lagrangian relaxation technique (DDLR) to develop a solution method called SAA-DDLR. Numerical experiments are conducted to illustrate the effectiveness and applicability of our model and method. Sensitivity analysis reveals that both the 4PL and 3PLs can benefit from the quantity discount scheme. Managerial insights are drawn for the 4PL to run a cost-effective logistics system in the presence of quantity discounts. [ABSTRACT FROM AUTHOR]

The competitive preference of a retailer is an important factor for closed-loop supply chains (CLSCs), which have not been explicitly investigated by existing studies. This paper specifically considers the retailer's competitive preference and examines decisions with regard to three CLSC channel structures—the manufacturer recycling channel (M-channel), the retailer recycling channel (R-channel), and the third-party recycling channel (T-channel). To mitigate the negative impact of the retailer's competitive preference, revenue-cost sharing (RCS) contracts can be developed. An interesting result is that the manufacturer will choose the T-channel when the degree of the retailer's competitive preference is higher than a specified threshold. [ABSTRACT FROM AUTHOR]

In recent years, Content‐Centric Networking (CCN) has been considered as a novel promising paradigm for the future Internet, shifting from provider‐driven end‐to‐end communication mode to interest‐driven content retrieval communication one, which greatly depends on routing technology. In spite of this, CCN routing always faces two significant issues, ie, scalability and large‐scale deployment, which restrict the increasing development of CCN but can be addressed by introducing the ideas of Software‐Defined Networking (SDN) and community (domain) division. However, the current routing proposals on the integrating with SDN, community division or their combination, still have some limitations to be improved. Therefore, in this paper, we propose a novel and intelligent CCN Routing mechanism based on SDN and Community Division (CRSCD). At first, a community division scheme based on eigenvetor centrality and label propagation is proposed to help content retrieval. Then, for each divided community, we deploy an SDN controller which consists of two tables, ie, content index and community topology to help manage the global network view. Finally, a comprehensive routing mechanism including intracommunity routing based on Ant Colony Optimization (ACO) and intercommunity routing based on interaction frequency is devised. The proposed CRSCD is implemented over Cogent topology, and the experimental results demonstrate that the introduction of SDN and community division can accelerate content retrieval greatly and has better performance than the previous work. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether the Institute of Medicine (IOM) recommended gestational weight gain (GWG) range is optimal among Chinese singleton pregnant women.Methods: For the purpose of a retrospective observational study, data on 8209 mature singleton deliveries in Shanghai from January 2014 to December 2016 were extracted from medical records in terms of clinical performance. All cases were categorized as undergainers, appropriate-gainers, and above-gainers according to IOM recommended gestational weight gain range after stratification of maternal BMI and proportions of three categories were calculated. Comparisons of maternal and neonatal outcome were conducted among three categories and the associations of those outcome including risks of low birth weight (LBW) and macrosomia (MAC) with GWG were estimated by logistic regression analysis. To examine the applicability of IOM recommendation for Chinese pregnant women, the accumulated risk of LBW and MAC was displayed by stacked column chart and comparison was made among GWG category. The joint predicted risk (JPR) curve of both LBW and MAC in relation to GWG (continuous measurement) was plotted to demonstrate the relation of lowest JPR corresponding GWG with IOM range.Results: The IOM recommended weight gain was achieved only by 3502 (42.7%) pregnant women and 41.6% gained excessive weight during pregnancy, especially for the overweight and obese women, the proportions of above-gainers mounting to 65.7 and 75.9%, respectively. By multivariate analysis GWG significantly influenced the risk of MAC and caesarean section. Although the association between the risk of LBW and GWG was not significant, p value reached .051. The risk of delivering macrosomia and caesarean section doubled when GWG exceeded the IOM rang. Appropriate gainers did not always gain the lowest joint risk of low birth weight and macrosomia from stacked column chart and it is obvious that the GWG point according to the lowest JPR was always located left to the IOM recommended range for each BMI category from the JPR curve chart in relation to GWG.Conclusions: The IOM recommended GWG range is possibly too much for Chinese singleton pregnant population for each BMI category. It is necessary to build different gestational weight gain standards for specific ethnic population. [ABSTRACT FROM AUTHOR]

Project procurement has two important attributes: cost uncertainty and failure risk. Due to the incomplete feature of such attributes, a novel mechanism incorporating contingent payments and cost sharing contracts is proposed for the buyer. Constructing models of bid decisions for risk averse and risk neutral suppliers, respectively, closed-form solutions of optimal bid prices are derived. By investigating the properties of bid prices in a first-score sealed-bid reverse auction, we find that when the degree of risk aversion or the variance of unpredictable cost is sufficiently small, bid prices of risk averse suppliers could be lower than those of risk neutral suppliers. Yet risk averse suppliers always bid higher than risk neutral suppliers in a second-score sealed-bid reverse auction. An interesting result verified by numerical experiments is that the classical revenue equivalence theorem no longer holds for the proposed mechanism if suppliers involve risk averse behavior. In this case, the buyer's best choice is to adopt a first-score sealed-bid reverse auction. We also provide decision support for the buyer to achieve optimal expected profit. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tongji Medical University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite promising performance at ambient temperature, the development of aqueous zinc batteries is jeopardized by the freeze of aqueous electrolytes and deteriorative electrode‐electrolyte interphase at low temperatures. Herein, inspired by the cryoprotective mechanism of extracellular polysaccharides in biological organisms, a quaternized galactomannan polysaccharide (q‐GPA) is proposed as a cryoprotective additive for improving low‐temperature performance of aqueous zinc batteries. Mechanistic studies revealed that a multi‐hydroxyl galactomannan backbone can substantially attenuate the activity of water molecules through the reconfiguration of the hydrogen bond network, which inhibits ice crystal formation at subzero temperatures and thus depress the freezing point of the electrolyte. Meanwhile, the quaternary ammonium groups tethered on the q‐GPA skeleton are intended to neutralize the interfacial electric field through electrostatic repulsion, thereby accelerating Zn2+ deposition kinetics and prohibiting zinc dendrite growth. Impressively, the q‐GPA–modified electrolyte enables an extended lifespan of over 1700 h in Zn||Zn symmetric battery at a high current density of 3 mA cm−2 and an ultralong cycle life of 5000 cycles with a capacity retention of 99.2% in the Zn||Na2V6O16·1.5H2O (NVO) full battery at −30 °C. This work provides unprecedented possibilities for optimizing the electrolyte formulation of low‐temperature aqueous batteries. [ABSTRACT FROM AUTHOR]