基于二元对称多项式的公平秘密共享方案

基于二元对称多项式,提出一种新的公平[(t,n)]门限秘密共享方案,能够确保：所有参与者都合法且诚实时,均能恢复正确的秘密;存在欺骗者时,所有参与者都无法恢复正确的秘密。该方案利用二元对称多项式不仅为任意两个参与者提供会话密钥;结合离散对数,在确保每个share持有者拥有较少share的情况下,使得Dealer可以选取足够长的秘密序列,从而确保方案的公平性。此外,方案在异步环境下也能实现公平秘密恢复。与Harn方案相比,该方案更加公平和灵活。     

动态分等级量子比特共享协议

量子秘密共享是量子密码研究的一个重要分支,针对多方共享量子比特情况进行研究,提出一个新的动态量子比特共享协议。此协议中,参与共享的成员是分等级的,量子信息的管理者在无需建立新的量子信道的情况下可对秘密重构系统中的参与者进行裁员。裁员后,管理者通过量子操作可以对量子信息进行更新,而剩余的有效参与者无需对自己手中的粒子执行额外操作就可完成新信息重构。此外,还讨论了协议的正确性、安全性及共享成员的等级性。     

Information sharing in capacity constrained supply chains under lost sales

We present a modelling approach for quantifying the value of information in supply chains using Markov decision processes (MDP). The case where information sharing occurs is modelled using a completely observable MDP. A restricted observation MDP is used to model the case where no information sharing occurs. We illustrate the use of this framework on a two-stage capacity-constrained supply chain consisting of a supplier and a retailer. We quantify the value of information sharing in this setting and construct several performance measures to identify the benefits to both the retailer and supplier as a result of the information sharing partnership.     

SWMRD: a Semantic Web-based manufacturing resource discovery system for cross-enterprise collaboration

As supply chains are becoming ever more global and agile in the modern manufacturing era, enterprises are increasingly dependent upon the efficient and effective discovery of shared manufacturing resources provided by their partners, wherever they are. Enterprises are thus faced with increasing challenges caused by the technical difficulties and ontological issues in manufacturing interoperability and integration over heterogeneous computing platforms. This paper presents a prototype intelligent system SWMRD (Semantic Web-based manufacturing resource discovery) for distributed manufacturing collaboration across ubiquitous virtual enterprises. Ontology-based annotation to the distributed manufacturing resources via a new, multidisciplinary manufacturing ontology is proposed on the semantic web to convert resources into machine understandable knowledge, which is a prelude to the meaningful resource discovery for cross-enterprise multidisciplinary collaboration. An ontology-based multi-level knowledge retrieval model is devised to extend the traditional information retrieval approaches based on keyword search, with integrated capabilities of graph search, semantic search, fuzzy search and automated reasoning to realise the intelligent discovery of manufacturing resources, e.g. to facilitate more flexible, meaningful, accurate and automated resource discovery. A case study for intelligent discovery of manufacturing resources is used to demonstrate the practicality of the developed system.     

On the Bullwhip Avoidance Phase: supply chain collaboration and order smoothing

This paper provides an assessment of the impact of collaboration and smoothing replenishment rules on supply chain operational performance and customer service level. Three supply chain configurations (i.e. Traditional, Information Exchange and Synchronised) in which orders are generated by smoothing (S, R) inventory control policies are studied for different proportional controllers. A supply chain stress test is performed through a sudden and intense change in demand. A structured and extended supply chain assessment framework is adopted. The main conclusions of this paper are the following. (i) The impact of Supply Chain Collaboration on overall supply chain performance is greater than that of order smoothing. Order smoothing mitigates the bullwhip effect, but it may have a negative impact on customer service. Supply Chain Collaboration mitigates the bullwhip effect, provides inventory stability, limits lumpy orders and enhances customer service level. (ii) The negative effect on customer service level of order smoothing is almost eliminated in synchronised supply chains.     

A semantic e-Kanban system for network-centric manufacturing: technology,scale-free convergence,value and cost-sharing considerations

It is critical to facilitate business partners to be seamlessly interoperable with each other as the network-centric manufacturing (NCM) paradigm becomes a major trend in today's manufacturing environment. In this work, we propose a semantic e-Kanban inventory system where a semantic gateway is acting as a mapping hub to enable heterogeneous messages to be seamlessly exchanged between business partners on demand. The semantic gateway uses reasoning rules to map business partners’ proprietary data schemas and provides interoperability required for NCM. To observe the network dynamics of our proposed system, a discrete time dynamic model is built and shows its growth to a scale-free network with a convergence rate depending on the initial connectivity of the semantic gateway and preferential attachment parameters. To analyse the proposed system from an economic perspective, analytical and numerical studies are conducted showing that it has enough potential to reduce supply chain costs in comparison to those of the traditional approach. Finally, this study attempts to address the cost-sharing issue encountered when multiple partners are direct beneficiaries of the efficiency gain through a joint network-centric capability, but it is questionable who should pay for the capability implementation. The cost-sharing issue must be investigated because most network-centric capabilities would not be economically or technically feasible for an individual company to achieve.     

Evaluating strategic issues in supply chain scheduling using game theory

This paper deals with the problem of scheduling and batch delivery of orders in a supply chain (SC) including a supplier, a manufacturer and a final customer. First, the individual decisions of partners in the SC and their behaviours are analysed through mathematical models. Second, the best policy is obtained assuming that the SC is vertically integrated and the partners fully cooperate (this is called SC scheduling in the relevant literature). Since this strategy is usually against a partner, it might not be implemented in practice as the authors have observed this condition in real world. Hence, a fair sharing mechanism based on game theory concepts is also introduced which can motivate the partners to cooperate and adopt the best policy of the SC. The numerical examples show the superiority of integrated decisions over independent actions and also the importance of the sharing mechanism.     

Trust-embedded coordination in supply chain information sharing

This paper studies supply chain coordination with trust-embedded cost-sharing contract. In a two-tier supply chain, a retailer (she) and a supplier (he) make their private demand forecasting individually. The retailer places soft-orders, which are costless, non-verifiable and cancellable before shipping, to the supplier. After that, the supplier relies on the retailer’s ordering information to update his demand evaluation and prepare his capacity. How much the supplier relies on the retailer’s ordering information is specified by trust, which is a kind of psychological feeling and affected by multiple factors. When the supplier does not fully trust the retailer, he tends to prepare a conservative capacity to avoid over-production. To coordinate the supply chain, a two-stage coordination process is proposed. At the first stage, the supplier and retailer negotiate a cost-sharing rule to bind soft-orders. At the second stage, the retailer places a soft-order and decides whether or not to bind it referring to the cost-sharing rule. After that, the supplier determines his optimal production capacity. We show that the retailer and supplier value trust differently in the experimental studies. We also find that there is a threshold of negotiation power for the supply chain partners which means the supplier’s/retailer’s expected profit drops down if his/her negotiation power exceeds certain thresholds. The experimental studies also show that the proposed the two-stage coordination is effective.     

Pixel expansion-free grey-scale image sharing method

Abstract

In recent years, many visual secret sharing technologies have been proposed to protect the security of secret images (black and white, grey scale or colour images). In 2005, Lukac and Plataniotis used the concept of the Naor–Shamir method to propose a visual secret sharing technology for sharing secret grey-scale images based on bit-plane decomposition. Although their method can avoid pixel-value cutting problem, it still suffers from the pixel expansion problem. In this paper, we propose a new secret grey-scale image sharing method to improve this situation. In the proposed sharing image creation phase, two sharing images (one is grey-scale and the other is binary) are created and later shared by two protectors. The original secret image can be easily reconstructed if both sharing images are obtained. However, one cannot obtain the original secret image from each of the sharing images. Experimental results also show that the proposed method can effectively solve the pixel expansion problem.     

TRICON ITCC系统在管道压缩机上的负荷分配控制应用

文章摘要：详细介绍了三台并列运行压缩机的控制策略。一套完善的控制方案能够有效地保护压缩机组的安全和节能降耗。尤其是在多机组串、并联应用时,采用一套完善的、合理的、自控程度高的控制方案时,只要对整个控制目标（主变参数）进行设定,就完全可以达到控制要求,同时减轻工艺操作人员工作强度。