Elementary symmetric polynomials in Shamir's scheme

The concept of k-admissible tracks in Shamir's secret sharing scheme over a finite field was introduced by Schinzel et al. (2009) [10]. Using some estimates for the elementary symmetric polynomials, we show that the track (1,…,n) over Fp is practically always k-admissible; i.e., the scheme allows to place the secret as an arbitrary coefficient of its generic polynomial even for relatively small p. Here k is the threshold and n the number of shareholders.     

On the Bullwhip Avoidance Phase: The Synchronised Supply Chain

The aim of this paper is to analyse the operational response of a Synchronised Supply Chain (SSC). To do so, first a new mathematical model of a SSC is presented. An exhaustive Latin Square design of experiments is adopted in order to perform a boundary variation analysis of the main three parameters of the periodic review smoothing (S, R) order-up-to policy: i.e., lead time, demand smoothing forecasting factor, and proportional controller of the replenishment rule. The model is then evaluated under a variety of performance measures based on internal process benefits and customer benefits. The main results of the analysis are: (I) SSC responds to violent changes in demand by resolving bullwhip effect and by creating stability in inventories under different parameter settings and (II) in a SSC, long production–distribution lead times could significantly affect customer service level. Both results have important consequences for the design and operation of supply chains.     

Meromorphic functions on compact Riemann surfaces and value sharing

Let X be a smooth and connected Riemann surface of genus g 0 and f: X P1, h: X P1 non-constant meromorphic functions on X. Fix an integer n 4 and assume the existence of n distinct points a1, , an P1 such that [image omitted] (set-theoretically) for every i. Here we prove that either f = h or [image omitted].     

高管薪酬监督博弈与独立董事有效性研究

研究聚焦董事会内部沟通网络,基于独立董事信息共享机制探讨对高管薪酬的监督效果。研究发现,独立董事相互之间通过共享信息来增强对高管自利行为的抑制能力,有效降低了高管薪酬。同时,管理者权力对独立董事信息共享机制的监督效力起到调节作用,具体表现为随着管理者权力的增强,独立董事信息共享对于高管薪酬的约束作用被弱化,这一结果说明独立董事信息共享机制的监督有效性受到管理者权力的限制。研究构建了独立董事信息共享指标,并基于董事会监督博弈过程分析信息共享对高管自利行为的约束过程,最后运用A股上市公司数据加以验证。研究拓展了对独立董事监督机制的认识,为打开董事会“黑箱”、提升董事会绩效提供新视角,促进公司治理机制由静态结构研究向动态过程研究转化。     

Three-Party Quantum State Sharing of an Arbitrary Unknown Two-Qubit State Based on Entanglement Swapping and Bell-State Measurements

We propose a scheme for sharing an arbitrary unknown two-qubit state among three parties by using a four-qubit cluster-class state and a Bell state as a quantum channel. With a quantum controlled phase gate (QCPG) operation and a local unitaryoperation, any one of the two agents has the access to reconstruct the original state if he/she collaborates with the other one, whilst individual agent obtains no information. As all quantum resource can be used to carry the useful information, the intrinsic efficiency of qubits approaches the maximal value. Moreover, the present scheme is more feasible with present-day technique.     

不同补贴对象下闭环供应链信息共享价值研究

在一个制造商和一个零售商组成的二级闭环供应链中,为研究政府补贴下供应链需求信息共享对决策的影响及共享价值,针对两种补贴对象,构建并求解无信息共享和信息共享博弈模型,并进行仿真验证.研究表明:1)两种补贴对象下,制造商均能从信息共享中获益,零售商仅在绿色成本和回收成本较低时才会从信息共享中获益;绿色成本和回收成本稍高时,...     

基于需求和生产成本偏差的Cournot竞争供应链协调

分析一个供应商和两个Cournot竞争零售商组成的供应链系统的协调问题.首先证明收益共享合约在稳定条件下能实现该供应链协调;当突发事件导致零售商面临的需求规模和供应商的生产成本同时与其预测值发生偏差时,为使供应链收益最大,提出了调整生产计划和零售价格的协调策略,进一步证明了改进的收益共享合约可协调需求和成本偏差的分权供应链;最后进行了数值实验.     

以权分担三个值的亚纯函数

该文处理了以权分担三个值的亚纯函数唯一性问题, 获得的结果改进了文献[1]的全部结果.     

Parameter estimation of continuous variable quantum key distribution system via artificial neural networks

Continuous-variable quantum key distribution(CVQKD)allows legitimate parties to extract and exchange secret keys.However,the tradeoff between the secret key rate and the accuracy of parameter estimation still around the present CVQKD system.In this paper,we suggest an approach for parameter estimation of the CVQKD system via artificial neural networks(ANN),which can be merged in post-processing with less additional devices.The ANN-based training scheme,enables key prediction without exposing any raw key.Experimental results show that the error between the predicted values and the true ones is in a reasonable range.The CVQKD system can be improved in terms of the secret key rate and the parameter estimation,which involves less additional devices than the traditional CVQKD system.     

Three-party quantum secret sharing of secure direct communication based on x-type entangled states

Based on x-type entangled states and the two-step protocol [Deng F G, Long G L and Liu X S 2003 Phys. Rev. A 68 042317], a quantum secret sharing protocol of secure direct communication based on x-type entangled states ｜X00〉3214 is proposed. Using some interesting entanglement properties of this state, the agent entirety can directly obtain the secret message from the message sender only if they collaborate together. The security of the scheme is also discussed.