XDP: A compiler intermediate language extension for the representation and optimization of data movement

The ability to represent, manipulate, and optimize data placement and movement between processors in a distributed address space machine is crucial in allowing compilers to generate efficient code. Data placement is embodied in the concept of dataownership. Data movement can include not just the transfer of data values but the transfer of ownership as well. However, most existing compilers for distributed address space machines either represent these notions in a language-or machine-dependent manner, or represent data or ownership transfer implicitly. In this paper we describe XDP, a set of intermediate language extensions for representing and manipulating data and ownership transfers explicitly in a compller. XDP is supported by a set of per-processor structures that can be used to implement ownership testing and manipulation at run-time, XDP provides a uniform framework for translating and optimizing sequential, data parallel, and message-passing programs to a distributed address space machine. We describe analysis and optimization techniques for this explicit representation. Finally, we compare the intermediate languages of some current distributed address space compilers with XDP.     

所有制结构调整中企业党建面临的难题与对策

随着所有制结构调整的不断深入,各类企业党建工作面临许多新难题,综合分析这些难题的表现和成因,提出相应的对策,对于加强和改进新时期的企业党建工作具有重要意义。     

租隙理论视角下的中国城市更新模式研究——基于深圳市的实证

从新马克思主义租隙理论出发,构建中国模式城市更新的分析框架。以深圳为例,发现土地性质和实施主体对租隙产生了差异化的影响。在城市更新过程中,正规用地和非国企主导的更新中租隙的变化规律更符合自由市场理论;在非正规用地和国企主导的更新中,政府的影响更显著。通过政府与国企之间的内部协调与外部平衡机制,国有企业可以承担在一定区位上的租隙损失,帮助政府实现所需要的城市更新目标。     

建筑物区分所有权制度对我国物业管理立法模式的影响

建筑物区分所有权作为一项基本的不动产所有权形式,由专有权、共有权和成员权三要素构成,是一种复合性的权利．区分所有建筑物的大量涌现,对其中所包含的复杂的法律制度的研究也成为必需．通过对建筑物区分所有权的分析探讨,阐明建筑物区分所有权制度与物业管理密不可分的关系,并进一步提出对我国物业管理立法模式选择的影响．     

基于用户定义安全条件的可验证重复数据删除方法

随着云存储用户数量的不断增长,重复数据删除技术得到了广泛的应用.如何在实现高效重复数据删除的同时,更好地保护用户数据隐私、实现客户端的安全多方计算,是云计算安全领域的研究热点问题.首次考虑了用户对重复数据删除过程的控制问题,引入了基于用户属性的安全条件机制,提出了基于用户定义安全条件的重复数据删除方法.基于双线性映射构造文件标识进行数据的查询,确保标识不泄露数据的任何明文信息.采用文件级和块级相结合的重复数据删除方法,提高了重复数据删除操作效率.基于安全多方计算理论和布隆过滤器技术实现数据的所有权证明,确保仅授权用户可获取数据的访问权,防范来自恶意用户的信道监听攻击.使用广播加密方法对数据加密密钥进行保护,实现了安全高效的重复数据删除.分析并证明了方案的安全性和正确性.仿真实验验证了方案的可行性和有效性.     

基于中国剩余定理的联合数字水印

将以中国剩余定理作为理论基础的asmuth-bloom秘密共享体系应用于数字水印中,提出了一种嵌入和检测联合数字水印的方法。在多个用户的应用环境中,这种方法不但加强了数字水印信息的安全性,防止某个仅有联合所有权的用户滥用权限,而且还改进了数字水印信息的冗余性。     

Drivers and barriers for the large-scale adoption of hydrogen fuel cells by Nordic shipping companies

The shipping industry needs to transition towards new fuels and technologies to reduce its environmental impact. A promising option is using hydrogen fuel cells. However, the technology is relatively new and not commercially available at a large scale. This study focuses on the Nordic shipping industry where the first commercial vessels are expected to be launched. Interviews were conducted with high-level managers to identify the factors that influence the adoption of hydrogen fuel cells. Sixteen factors are identified as motivating the decision and are categorized as internal, connecting, and external drivers. The most relevant are environmental commitments, customer expectations, and policies and regulations. Eleven factors are identified as limiting the decision and are categorized as behavioral, economic, organizational, and technological barriers. The most significant are high costs, lack of infrastructure, and operational challenges. The drivers and barriers are categorized as company-specific, industry-specific, and technology-specific.     

Modular specification of frame properties in JML

We present a modular specification technique for frame properties. The technique uses modifies clauses and abstract fields with declared dependencies. Modularity is guaranteed by a programming model that enforces data abstraction by preventing representation and argument exposure, a semantics of modifies clauses that uses a notion of ‘relevant location’, and by modularity rules for dependencies. For concreteness, we adapt this technique to the Java Modeling Language, JML. Copyright © 2003 John Wiley & Sons, Ltd.