Past and future of software architectural decisions – A systematic mapping study

ContextThe software architecture of a system is the result of a set of architectural decisions. The topic of architectural decisions in software engineering has received significant attention in recent years. However, no systematic overview exists on the state of research on architectural decisions.ObjectiveThe goal of this study is to provide a systematic overview of the state of research on architectural decisions. Such an overview helps researchers reflect on previous research and plan future research. Furthermore, such an overview helps practitioners understand the state of research, and how research results can help practitioners in their architectural decision-making.MethodWe conducted a systematic mapping study, covering studies published between January 2002 and January 2012. We defined six research questions. We queried six reference databases and obtained an initial result set of 28,895 papers. We followed a search and filtering process that resulted in 144 relevant papers.ResultsAfter classifying the 144 relevant papers for each research question, we found that current research focuses on documenting architectural decisions. We found that only several studies describe architectural decisions from the industry. We identified potential future research topics: domain-specific architectural decisions (such as mobile), achieving specific quality attributes (such as reliability or scalability), uncertainty in decision-making, and group architectural decisions. Regarding empirical evaluations of the papers, around half of the papers use systematic empirical evaluation approaches (such as surveys, or case studies). Still, few papers on architectural decisions use experiments.ConclusionOur study confirms the increasing interest in the topic of architectural decisions. This study helps the community reflect on the past ten years of research on architectural decisions. Researchers are offered a number of promising future research directions, while practitioners learn what existing papers offer.     

VARI工艺在建筑物加固修复上的应用

本文叙述了VAR I工艺特点及其用于建筑物加固修复的重要性、优越性和应用前景。自制了一套简易实验装置,归纳并阐述了建筑物加固修复用VAR I技术的主要内容。针对国内的情况,提出了该领域亟待开展的研究工作。     

Computational Problem Solving in Spatial Substrates -- A Cognitive Systems Engineering Approach

The ability to perform spatial tasks is crucial for everyday life and of great importance to cognitive agents such as humans, animals, and autonomous robots. A common artificial intelligence approach to accomplish spatial tasks is to represent spatial configurations and tasks in form of detailed knowledge about various aspects of space and time. Suitable algorithms then use the representations to compute solutions to spatial problems. In comparison, natural embodied and situated agents often solve spatial tasks without detailed knowledge about geometric, topological, or mechanical laws; they directly relate actions to effects that are due to spatio-temporal affordances in their bodies and environments. Accordingly, we propose a paradigm that makes the spatio-temporal substrate an integral part of the engine that drives spatial problem solving. We argue that spatial and temporal structures in body and environment can substantially support (and even replace) reasoning effort in computational processes: physical manipulation and perception in spatial environments substitute formal computation. While the approach is well known – for example, we employ diagrams as spatial substrate for geometric problem solving and maps for wayfinding – the underlying principle has not been systematically investigated or formally analyzed as a paradigm of cognitive processing. Topology, distance, and orientation constraints are all integrated and interdependent in truly 2- or 3-dimensional space. Exploiting this fact may not only help overcome the need for acquiring detailed knowledge about the interrelationships between different aspects of space; it also can point to a way of avoiding exploding computational complexity that occurs when we deal with these aspects of space in complex real-world scenarios. Our approach employs affordance-based object-level problem solving to complement knowledge-level formal approaches. We will assess strengths and weaknesses of the new cognitive systems paradigm.     

智能化结构分析建模方法

建立正确的模型是进行机械结构分析的关键技术之一。提出了一种基于知识的结构分析建模方法,给出了基于知识结构分析建模方法的总体结构,讨论了知识的获取、分类与表达,提出了推理机制以及智能求解策略,提高了结构有限元分析建模方法的实用性和有效性。最后用实例说明了应用效果。     

Customizable hardware design of fuzzy controllers applied to autonomous car driving

Nowadays, final products often encompass a certain intelligence therein to deal with variation or lack of precision in the sensing input data. This intelligence is usually acquired via the utilization of existing soft techniques, such as artificial neural networks, genetic algorithms and fuzzy control, among others. Thus, it is profitable to have on-the-shelf shell scalable and adaptive hardware designs that implement these soft techniques. This availability allows for an immediate embedding of any of those designs onto final products. This usually entails a reduced time-to-market of the product. Process control is one of the many applications that took advantage of the fuzzy paradigm. In general, controllers are embedded into the controlled device. This paper presents a novel design of a reconfigurable efficient parallel architecture to implement fuzzy controllers on hardware with almost no design effort for final users. The proposed architecture is herein proven suitable for embedding. It is customizable, so it allows the setup and configuration of the controller parameters, and hence its use for any problem application. Two fuzzy controllers that model autonomous car driving are implemented and their cost and performance evaluated.     

主流视频编解码软件的硬件性能分析与设计

网络视频会议以及高清视频点播等应用的广泛流行,对视频编解码的编码质量以及编码速度提出了更高的要求。为帮助硬件设计人员设计更强大的专用处理器去适应视频编解码应用的发展趋势,并评估处理器设计的合理性和正确性,对视频编解码进行分析和测试,提出一套基准测试程序。采用自顶向下的分析方法,以流行性、编解码效率、压缩质量和开源性为标准,选取主流的视频编解码软件,进行热点函数分析。抽取变换、量化以及滤波过程中的热点函数,使之成为视频编解码测试程序,为其构造典型输入集。通过分析真实硬件平台上这些测试程序的计算和访存特性,给出处理器设计的建议。结果证明,该基准测试程序使用10%的代码量即可反映视频编解码过程的主要特征,对处理器设计具有指导意义。     

Prevention from Soft Errors via Architecture Elasticity

Due to the decreasing threshold voltages, shrinking feature size, as well as the exponential growth of on-chip transistors, modern processors are increasingly vulnerable to soft errors. However, traditional mechanisms of soft error mitigation take actions to deal with soft errors only after they have been detected. Instead of the passive responses, this paper proposes a novel mechanism which proactively prevents from the occurrence of soft errors via architecture elasticity. In the light of a predictive model, we adapt the processor architectures h01istically and dynamically. The predictive model provides the ability to quickly and accurately predict the simulation target across different program execution phases on any architecture configurations by leveraging an artificial neural network model. Experimental results on SPEC CPU 2000 benchmarks show that our method inherently reduces the soft error rate by 33.2% and improves the energy efficiency by 18.3% as compared with the static configuration processor.     

一种新型指纹锁电路设计

市场上主流的电子锁是基于密码设计的。密码锁的最大的缺陷是密码容易被他人窃取、猜测及遗忘。随着生物技术的发展,越来越多的活体技术应用到识别系统中,如指纹、掌纹、人脸、虹膜等。相对于其它的活体识别技术,指纹识别系统以其可实现性强,成本相对低廉,同时又具备较高的安全性,被越来越多的应用到各种场合。文章给出了一种新型的指纹锁架构,并详细论述了系统的各个组成部分以及指纹识别算法的实现流程。文章对降低系统功耗和增加保密性都提出了独特的方法。     

气象传感器网络系统架构与体系结构研究

传感器网络将在气象观测领域发挥越来越重要的作用。针对地面气象观测的现实需求,提出了气象传感器网络的概念,构建了气象传感器网络的应用场景,完成了其需求分析与系统架构设计,深入分析了气象传感器网络可采用的通信手段。在陆上传感器网络体系结构的基础上,结合气象传感器网络的特点,设计了气象传感器网络的体系结构,将其结构划分为物理层、数据链路层和网络层。对该体系结构各层的功能进行了深入分析,最后对气象传感器网络的应用前景进行了展望。     

An exploratory study on ontology engineering for software architecture documentation

The usefulness of Software Architecture (SA) documentation depends on how well its Architectural Knowledge (AK) can be retrieved by the stakeholders in a software project. Recent findings show that the use of ontology-based SA documentation is promising. However, different roles in software development have different needs for AK, and building an ontology to suit these needs is challenging. In this paper we describe an approach to build an ontology for SA documentation. This approach involves the use of typical questions for eliciting and constructing an ontology. We outline eight contextual factors, which influence the successful construction of an ontology, especially in complex software projects with diverse AK users. We tested our ‘typical question’ approach in a case study and report how it can be used for acquiring and modeling AK needs.