基于移动边缘计算的V2X任务卸载方案

移动边缘计算(MEC)通过在移动网络边缘提供IT服务环境和云计算能力带来高带宽、低时延优势,从而在下一代移动网络的研究中引起了广泛的关注。该文研究车载网络中车辆卸载请求任务时搜寻服务节点为其服务的匹配问题,构建一个基于MEC的卸载框架,任务既可以卸载到MEC服务器以车辆到基础设施(V2I)形式通信,也可以卸载到邻近车辆进行车辆到车辆(V2V)通信。考虑到资源有限性、异构性,任务多样性,建模该框架为组合拍卖模式,提出一种多轮顺序组合拍卖机制,由层次分析法(AHP)排序、任务投标、获胜者决策3个阶段组成。仿真结果表明,所提机制可以在时延和容量约束下,使请求车辆效益提高的同时最大化服务节点的效益。     

用JMS技术实现网上拍卖系统实时信息发布功能

网络实时拍卖系统是一个模拟拍卖现场完成拍卖活动的网络交易系统,本文提出实现此系统的总体方案和系统架构,以及如何使用JMS技术实现实时信息发布功能,并且给出了实现此功能的部分程序。     

一种结合拍卖的D2D协作通信中继选择算法

D2D协作通信技术可以满足提高蜂窝通信系统容量、扩大网络覆盖范围的通信需求。针对一些边缘用户受到信道衰落影响较大,从而影响用户的服务质量问题,提出了一种将拍卖原则引入D2D协作通信的中继选择算法。该算法首先在满足D2D通信要求和信噪比限制条件下得到中继备选集合;然后以优化链路吞吐量为目标选择最优中继节点;最后当两个或多个用户同时选中一个最优中继节点时,采用拍卖原则为D2D发射端分配最终中继。仿真结果表明,所提算法不仅有效地提高了吞吐量,同时保证了系统的中断概率。     

Resource trading in cloud environments for utility maximisation using game theoretic modelling approach

We develop a novel auction-based scheme for trading free processors in cloud computing environment. Our scheme allows clients to fairly compete for the offered processors. Second-price auction is used where each client bids for the processors. The client that makes the higher bid wins the auction and starts using the processors for executing its jobs. The winner pays the second highest bid. Maximising profit is the key objective for the cloud provider (CP). The optimisation problem of renting processors on the cloud market is a complex and challenging task. The proposed mechanism takes into account the market demand and the economic concerns for the CP and clients. Within this context, we show the existence of a Nash equilibrium which leads to a unique allocation under certain processors distribution. Numerical analysis stresses the ability of our approach to maximise the client's utility under varying cloud environment conditions.     

基于单频段多赢家拍卖的动态频谱分配

针对传统拍卖方法在认知无线网络动态频谱分配中的低效问题,提出了一种基于单频段多赢家拍卖的动态频谱分配算法。该算法在原始贪婪算法的基础上增加了多重贪婪策略,以较低的计算复杂度获得了较优的解;改进了VCG(vickery-clarke-groves)机制,在保留占优策略激励兼容特性的基础上,提高了卖家的收益,有效抑制共谋的发生。仿真结果表明,该算法的频谱分配效率接近最优分配效率,同时提高了拍卖的经济收益。     

基于拍卖机制的网格在线信誉系统模型

在现有的网格经济模型和在线信誉系统的基础上,提出了基于拍卖机制的网格在线信誉系统模型.该模型侧重于保护资源提供者,为资源提供者提供了贡献与共享资源的动机,吸引更多更好的资源加入网格,实现资源优化分配.保证交易双方均获取最大利益,有利于网格资源的市场管理及供需均衡.并以市场为平台,构建一种新的网格信任模型,由交易事件和衰减函数共同驱动信任度的在线更新,并引入激励机制,尽可能增强信任模型的合理性和可操作性.     

The role of beliefs in purchasing process of functional foods

This study utilizes food values in conjunction with willingness to pay (WTP) measures to identify consumers’ subjective beliefs about functional foods. We conducted a non-hypothetical, second price experimental auction (i.e., a Vickrey auction) to estimate WTP for a new functional snack made with white lupine and citrus fiber. A sample of 156 consumers was surveyed in Catania, Sicily (Italy) in July 2015. The findings of the economic experiment reveal a WTP premium for the new functional snack, a premium which depends on functional components but also on other characteristics that go beyond intrinsic healthy properties. Consumers’ WTP for functional foods significantly varies with food values related to origin, safety, naturalness, price, etc., which implies consumers have different subjective beliefs about functional and non-functional foods. These findings have implications for the food sector attempting to design and promote consumption of functional foods, and suggest health is not the only factor motivating functional food purchases.     

Combining experimental auctions with a modified home-use test to assess rural consumers’ acceptance of quality protein maize,a biofortified crop

Biofortification, or breeding food crops for improved nutritional content, is a cost effective way to improve nutritional status. The process can, however, alter the sensory characteristics of the crop, and consumer acceptance is essential for their adoption. The oldest biofortified crop is quality protein maize (QPM), biofortified with essential amino acids, a trait now incorporated in many recently-released varieties in East Africa. To estimate rural consumers’ acceptance and willingness to pay (WTP) for QPM in the dispersed population of Northern Tanzania, a novel method, combining a modified home-use test with a Becker–DeGroot–Marschak experiment, was developed. The results showed that rural consumers in Tanzania could distinguish stiff porridge made from QPM and from conventional maize (CM). They generally preferred the former, as expressed by higher scores during affective tests for texture, taste, and overall qualities. Further, rural consumers who were not provided with information about the nutritional benefits of QPM were willing to pay a premium of 16% over CM, and those who were given information, 39%. The scores on the affective test and the information on QPM’s nutritional benefits were the main factors determining WTP in the experiment, while no personal characteristics of the participants were found to be significant. We conclude that QPM is, at least, as well accepted as conventional maize, and preferred for its sensory characteristics. Information on nutritional benefits increases rural consumers’ willingness to pay for it, so information campaigns may be effective in increasing demand for QPM varieties. However, these varieties need to be competitive for other characteristics that rural households value, in particular, field and storage qualities.     

Analysis of fraudulent behavior strategies in online auctions for detecting latent fraudsters

Online auction fraudsters constantly monitor the contextual situations of the auction and change their behavior strategies accordingly to distract the attention of their targets. This flipping of behavior makes it difficult to identify fraudsters. Thus, legitimate traders need appropriate countermeasures to avoid becoming victimized. To help online auction users detect fraudsters as early as possible, this study develops a systematic method to discover the fraudulent strategies from proven cases of online auction fraud. First, according to the results of cluster analysis on the proven fraudsters, four typical types of fraud are identified, which are Aggressive, Classical, Luxury and Low-profiled. To provide better insight, a strategy is further represented by a series of status transitions. Hidden statuses of latent fraudsters are discovered by applying X-means clustering to the phased profiles of their transaction histories. As a result, various strategies can be extracted by such a systematic method and interesting characteristics are found in these strategies. For example, about 80% fraudsters in the Yahoo!Taiwan auction site flip their behavior no more than two times, which is not as complicated as expected originally. Based on these discovered fraudulent statuses, a high-resolution fraud detection method is performed to classify suspects into legitimate users or fraudsters in different statuses, potentially improving overall detection accuracy. A two-way monitoring procedure is then proposed to successively examine the statuses of a suspicious account. Analysis shows that the two-way monitoring method is promising for better detection of well-camouflaged fraudsters.     

基于群签名的公平电子拍卖方案

本文基于一个群签名方案及可验证秘密共享,设计了一个新的密封投标的电子拍卖系统,利用群签名的性质,系统具有可保护投标人的投标价和防止中标人抵赖的特点;由于我们利用了高效的群签名方案使得协议具有步骤简略,计算量小等特点,使得本协议具有很高的效率。