A language-independent approach to the extraction of dependencies between source code entities

ContextSoftware networks are directed graphs of static dependencies between source code entities (functions, classes, modules, etc.). These structures can be used to investigate the complexity and evolution of large-scale software systems and to compute metrics associated with software design. The extraction of software networks is also the first step in reverse engineering activities.ObjectiveThe aim of this paper is to present SNEIPL, a novel approach to the extraction of software networks that is based on a language-independent, enriched concrete syntax tree representation of the source code.MethodThe applicability of the approach is demonstrated by the extraction of software networks representing real-world, medium to large software systems written in different languages which belong to different programming paradigms. To investigate the completeness and correctness of the approach, class collaboration networks (CCNs) extracted from real-world Java software systems are compared to CCNs obtained by other tools. Namely, we used Dependency Finder which extracts entity-level dependencies from Java bytecode, and Doxygen which realizes language-independent fuzzy parsing approach to dependency extraction. We also compared SNEIPL to fact extractors present in language-independent reverse engineering tools.ResultsOur approach to dependency extraction is validated on six real-world medium to large-scale software systems written in Java, Modula-2, and Delphi. The results of the comparative analysis involving ten Java software systems show that the networks formed by SNEIPL are highly similar to those formed by Dependency Finder and more precise than the comparable networks formed with the help of Doxygen. Regarding the comparison with language-independent reverse engineering tools, SNEIPL provides both language-independent extraction and representation of fact bases.ConclusionSNEIPL is a language-independent extractor of software networks and consequently enables language-independent network-based analysis of software systems, computation of design software metrics, and extraction of fact bases for reverse engineering activities.     

Hybrid systems in seawater desalination—practical design aspects, present status and development perspectives

Ever since seawater desalination has been applied on an industrial scale, and particular in the countries of the Arabian Gulf, the application of desalination processes in dual-purpose facilities—water and power—as a hybrid configuration has been discussed in many feasibility investigations and also planning concepts. It is above all the combination of reverse osmosis with thermal processes that has found increasing interest with the aim of ensuring, as economically as possible, uniform water supplies under the specific, greatly varying load conditions in the Gulf countries. Such design concepts for hybrid configurations encompass straightforward structures with a low degree of coupling between membrane and thermal desalination processes, but range up to very complex configurations with strong interconnections on both the water side and thermally, as well as with several desalination processes connected in series or in parallel. Classical hybrid concepts in which the permeate from an RO desalination component is mixed with distillate from thermal desalination have already been implemented in Saudi Arabian dual-purpose plants, like Jeddah and Yanbu-Medina. Although hybrid systems of greater complexity have been addressed in many design studies and publications, up to now none has been brought to fruition. Coming into consideration asthe design basis for determining the capacity shares of the various desalination processes operated in a hybrid configuration are: arrangement of thermal cycle of the power plant component; water/power ratio of the dual-purpose seawater desalination and power plant; provision of undiminished water production of the desalination plant as electricity generation varies; provision of a specified drinking water quality with regard to composition and salt content; combination of all these aspects. Also gaining in importance are concerns of environmental pollution and sustainable development when selecting seawater desalination and power plant configurations, as well as their optimization when considering desalination and electricity generation as a whole. In the practical design of hybrid membrane and thermal systems, aspects come to light, though, that restrict linking of the two systems and joint utilization of facilities, as conceived in studies and conceptual design investigations. This applies both for common utilization of intakes and the use of heated up cooling water from thermal processes as a feed stream for the RO part of the desalination process. Additionally, requirements of drinking water composition, particularly chloride content, TDS and compliance with a specific residual content of boron, influence specifically the design of the membrane process part and its share in the total desalination capacity. Such practical aspects have greatly influenced the design and configuration of the Fujairah hybrid plant for which, from a total desalination capacity of 100 MIGD (454,600 m³/d), the share of 37.5 MIGD (170,500 m³/d) makes its seawater RO plant the biggest currently being constructed anywhere in the world. From the findings of the engineering of this plant and the idea that, by increasing interconnection between the two processes on the water side, it is possible to advance a hybrid configuration of this type with regard to cost optimization in the membrane installation, but also by joint utilization of the intake equipment, perspectives result for applied research efforts over the near and long terms, for example: long-term behavior of membranes at elevated temperatures; tendency for biofouling in membrane process with common utilization of cooling water and brine; influences of such interconnections on the overall availability of the facility. But also for the operation and maintenance organization of such large facilities, consequences can be foreseen for the future development of hybrid plants, particularly for operation management and organisation of the interplay of the different power plant and desalination systems, monitoring of SWRO membrane replacement and cleaning, as well as controlling water quality.     

Novel image fusion scheme based on dependency measure for robust multispectral palmprint recognition

Multispectral palmprint is considered as an effective biometric modality to accurately recognize a subject with high confidence. This paper presents a novel multispectral palmprint recognition system consisting of three functional blocks namely: (1) novel technique to extract Region of Interest (ROI) from the hand images acquired using a contact less sensor (2) novel image fusion scheme based on dependency measure (3) new scheme for feature extraction and classification. The proposed ROI extraction scheme is based on locating the valley regions between fingers irrespective of the hand pose. We then propose a novel image fusion scheme that combines information from different spectral bands using a Wavelet transform from various sub-bands. We then perform the statistical dependency analysis between these sub-bands to perform fusion either by selection or by weighted fusion. To effectively process the information from the fused image, we perform feature extraction using Log-Gabor transform whose feature dimension is reduced using Kernel Discriminant Analysis (KDA) before performing the classification by employing a Sparse Representation Classifier (SRC). Extensive experiments are carried out on a CASIA multispectral palmprint database that shows the strong superiority of our proposed fusion scheme when benchmarked with contemporary state-of-the-art image fusion schemes.     

支持依赖修复的热部署技术

热部署机制是主流应用服务器的典型功能之一。但是目前的应用服务器仅仅支持独立应用的热部署,并不能满足具有依赖注入的复杂企业级应用在线更新的需求。如果在线更新部分模块,会出现程序调用失效的问题,并会导致整个应用平台的失效。为了解决这个问题,介绍一种支持依赖修复的热部署技术。在首次部署应用的各模块时,用该技术建立模块之间的依赖关系。而在其更新时,通过查找依赖关系,找出受到更新影响的模块,修复依赖并进行局部的热部署,避免重启应用服务器的代价。最后通过实验表明,该热部署技术可以保证依赖注入下的应用正确性;在实际工程应用的场景下,该技术也能够大幅度提升应用服务器的性能和运行效率。     

Impact analysis and change propagation in service-oriented enterprises: A systematic review

ContextThe adoption of Service-oriented Architecture (SOA) and Business Process Management (BPM) is fairly recent. The major concern is now shifting towards the maintenance and evolution of service-based business information systems. Moreover, these systems are highly dynamic and frequent changes are anticipated across multiple levels of abstraction. Impact analysis and change propagation are identified as potential research areas in this regard.ObjectiveThe aim of this study is to systematically review extant research on impact analysis and propagation in the BPM and SOA domains. Identifying, categorizing and synthesizing relevant solutions are the main study objectives.MethodThrough careful review and screening, we identified 60 studies relevant to 4 research questions. Two classification schemes served to comprehend and analyze the anatomy of existing solutions. BPM is considered at the business level for business operations and processes, while SOA is considered at the service level as deployment architecture. We focused on both horizontal and vertical impacts of changes across multiple abstraction layers.ResultsImpact analysis solutions were mainly divided into dependency analysis, traceability analysis and history mining. Dependency analysis is the most frequently adopted technique followed by traceability analysis. Further categorization of dependency analysis indicates that graph-based techniques are extensively used, followed by formal dependency modeling. While considering hierarchical coverage, inter-process and inter-service change analyses have received considerable attention from the research community, whereas bottom-up analysis has been the most neglected research area. The majority of change propagation solutions are top-down and semi-automated.ConclusionsThis study concludes with new insight suggestions for future research. Although, the evolution of service-based systems is becoming of grave concern, existing solutions in this field are less mature. Studies on hierarchical change impact are scarce. Complex relationships of services with business processes and semantic dependencies are poorly understood and require more attention from the research community.     

Dependency mining-based causal message logging

In fault-tolerant computing, the approach of causal message logging provides on-demand stable logging and enables the independent recovery of nodes. It imposes the requirement that the dependency between non-deterministic events needs to be known for nodes. The dependency information is disseminated through messages. A central problem in traditional causal message logging is that if the message logging progress of nodes cannot be effectively tracked, some redundant dependency information will be piggybacked on the messages. In this paper, a dependency mining based approach is proposed. It tries to detect the message logging progress of nodes only from the dependency between non-deterministic events, without needing to piggyback an additional dependency vector or dependency matrix on each message.     

Modular analysis and modelling of risk scenarios with dependencies

The risk analysis of critical infrastructures such as the electric power supply or telecommunications is complicated by the fact that such infrastructures are mutually dependent. We propose a modular approach to the modelling and analysis of risk scenarios with dependencies. Our approach may be used to deduce the risk level of an overall system from previous risk analyses of its constituent systems. A custom made assumption-guarantee style is put forward as a means to describe risk scenarios with external dependencies. We also define a set of deduction rules facilitating various kinds of reasoning, including the analysis of mutual dependencies between risk scenarios expressed in the assumption-guarantee style.     

基于词间依存的汉语基本块依存关系识别

基本块的分析是句法分析中的重要技术,根据依存理论,提出了一种分析基本块之间的依存关系的方法。首先使用BIO标记来识别基本块,然后根据词之间的依存关系判别基本块之间的依存关系。实验表明,基本块识别的正确率和召回率分别为82.3%和78%,基本块之间依存关系识别的正确率和召回率分别为89%和90.5%。     

基于最大熵模型的汉语依存分析

采用最大熵模型实现中文依存语法的分析。用自底而上的方式构建语句的依存关系树，构建过程每一步在向左连接、向右连接以及不连接3种动作选取其一。用最大熵原理判断每个动作的概率，得到依存树中各边的概率，然后找出具有最大概率的依存关系树。实验结果表明，该模型具有较好的分析精度。目前，该模型已被应用于基于自然语言的信息检索项目中。