Practical access control management for distributed collaborative editors

The project summarized in this article aims at developing techniques to support access control in Real-Time Distributed Collaborative Editors (RCE). The ever-increasing role of RCE in academic, industry and society comforts the expansion of data sharing and raises growing concerns about controlling access to this data. Indeed, RCE allow for a human–computer–human interaction in a decentralized fashion. Thus, access control for RCE requires a careful design since they need dynamic access changes and low latency access to shared document while maintaining its consistency.In this article, we propose a flexible access control model where the shared document and its authorization policy are replicated in the local memory of each user. To deal with latency and dynamic access changes, we use an optimistic access control technique in such a way that enforcement of authorizations is retroactive. Our model is generic enough to be deployed on the top of the most of existing logging-based collaborative systems. Indeed, it does not entail overheads and it does not affect the convergence of the shared document. We show that naive coordination between updates of both copies can create security holes on the shared document, by permitting illegal modifications or rejecting legal modifications and present our solutions to avoid these problems. Finally, we present a prototype for managing authorizations in collaborative editing work in a decentralized fashion. Thus our model may be deployed easily on mobile devices over P2P networks.     

Web服务技术-大数据抓取及存储的研究与实现

简述web服务的关键技术以及其发展的过程,并对一些关键技术进行阐述,web服务是有自己独特的体系,拥有自己的一套架构,并且在这套架构上,web服务拥有自己的核心技术,当单个的web服务难以满足需求的时候,这时候web服务组合就出现了,它能够很好的解决单个web所不能解决的问题,这个很好的满足了现代社会的需求,最后提出web服务技术的未来,其中重点是说明web服务的核心技术。随着网络的兴起,web服务技术被广泛应用于大数据的海洋抓取,比如代购网站中,就需要用到数据的海洋抓取和存储。     

Automatic design of fuzzy logic controllers for medium access control in wireless body area networks – An evolutionary approach

Soft computing techniques including fuzzy logic have been successfully applied to wireless body area networks (WBANs). However, most of the existing research works rely on manual design of the fuzzy logic controller (FLC). To address this issue, in this paper, we propose an evolutionary approach to automate the design of FLCs for cross layer medium access control in WBANs. With the goal of improving network reliability while keeping the communication delay at a low level, we have particularly studied the usefulness of three coding schemes with different levels of flexibility during the evolutionary design process. The influence of fitness functions that measure the effectiveness of each possible FLC design has also been examined carefully in order to achieve a good balance between reliability and performance. Moreover, we have utilised surrogate models to improve the efficiency of the design process. In consideration of practical usefulness, we have further identified two main design targets. The first target is to design effective FLCs for a specific network configuration. The second target focuses on designing FLCs to function across a wide range of network settings. In order to examine the usefulness of our design approach, we have utilised two widely used evolutionary algorithms, i.e. particle swarm optimisation (PSO) and differential evolution (DE). The FLC designed by our approach is also shown to outperform some related algorithms as well as the IEEE 802.15.4 standard.     

浅谈如何更有效的提升煤矿工会的服务管理效能

企业工会是我们党领导的基层群众组织。从煤矿企业工会的角度,对怎样切实提高其服务职工、管理职工的水平与能力进行了探讨。     

Kinematical analysis of the trunk,upper limbs and fingers during minimal access surgery when using an armrest

This study investigated whether using an armrest could reduce the movements of the trunk, upper limb and hand of surgeons during simulated minimal access surgery. Sixteen surgeons carried out two trials of simulated laparoscopic surgery, one using an armrest and the other without. Reflective markers were attached on the trunk, upper limbs, fingers, minimal access camera (MAC) and scissors, allowing a motion capture system to record the movements. The error ratios during operation, subjective opinions and operative durations were collected. The results showed that total displacements at the trunk and shoulders were reduced by at least 25% when using an armrest compared with not using one; error ratios were reduced by 7%; velocity and acceleration in the trunk, shoulder and MAC were reduced. After simulated operations, 78% of the participants preferred using the armrest. The study indicates that an armrest could improve surgical outcomes by reducing trunk movements.     

面向新产品开发的云制造服务资源组合优选模型

针对面向新产品开发的云制造服务资源组合在优选过程中的不确定性、粗粒度性、多样性、动态性等特点,提出包含T（服务时间）、Q（服务质量）、C（服务成本）、A（可用性）、Co（可组合性）、Tr（可信任性）、Ma（可维护性）和Su（可持续性）等八大目标变量的优选目标体系,建立一种面向新产品开发的云制造服务资源组合优选模型,并采用灰色关联度分析方法对该模型的求解过程进行了分析。以一个应用实例验证了该优选目标体系及优选模型的正确性和实用性。     

Innovation and the growth of service companies: the variety of firm activities and industry effects

This paper examines the relationship between innovation performance and employment growth in firms by taking a closer look at specific innovation activities and industry effects in the context of the services sector. Firm-level CIS data on Polish services firms in 2004–2009 are analysed using robust M-estimation. The results indicate that the effects of product, process and organisational innovations depend strongly on the level of technological opportunities in the industry in question. Given the widely acknowledged role of marketing innovations in services, possible synergies between innovations in the form of new products and new marketing techniques are also analysed. We demonstrate that marketing innovations are conducive to firm growth if they complement product innovations, but they are less likely to foster growth when applied in isolation.     

Towards a trust evaluation middleware for cloud service selection

With the advent of cloud computing, employing various cloud services to build highly reliable cloud applications has become increasingly popular. The trustworthiness of cloud services is a critical issue that hinders the development of cloud applications, and thus is an urgently-required research problem. Previous studies evaluate trustworthiness of services via either QoS monitoring mechanisms or user feedback ratings, while seldom they combine both of them for enhancing service trust evaluation. This paper proposes a trustworthy selection framework for cloud service selection, named TRUSS. Aiming at developing an effective trust evaluation middleware for TRUSS, we propose an integrated trust evaluation method via combining objective trust assessment and subjective trust assessment. The objective trust assessment is based on QoS monitoring, while the subjective trust assessment is based on user feedback ratings. Experiments conducted using a synthesized dataset show that our proposed method significantly outperforms the other trust and reputation methods.