Software-as-a-service （SaaS）： perspectives and challenges

Software-as-a-service （SaaS） has received significant attention recently as one of three principal components of cloud computing, and it often deals with applications that run on top of a platform-as-a-service （PaaS） that in turn runs on top of infrastructure-as-a-service （IaaS）. This paper provides an overview of SaaS including its architecture and major technical issues such as customization, multi-tenancy architecture, redun- dancy and recovery mechanisms, and scalability. Specifically, a SaaS system can have architecture relating to a database-oriented approach, middleware-oriented approach, service-oriented approach, or PaaS-oriented ap- proach. Various SaaS customization strategies can be used from light customization with manual coding to heavy customization where the SaaS system and its underlying PaaS systems are customized together. Multi-tenancy architecture is an important feature of a SaaS and various trade-offs including security isolation, performance, and engineering effort need to be considered. It is important for a SaaS system to have multi-level redundancy and recovery mechanisms, and the SaaS system needs to coordinate these with the underlying PaaS system. Finally, SaaS scalability mechanisms include a multi-level architecture with load balancers, automated data migration, and software design strategies.     

Principles and experimentations of self-organizing embedded agents allowing learning from demonstration in ambient robotics

Ambient systems are populated by many heterogeneous devices to provide adequate services to their users. The adaptation of an ambient system to the specific needs of its users is a challenging task. Because human–system interaction has to be as natural as possible, we propose an approach based on Learning from Demonstration (LfD). LfD is an interesting approach to generalize what has been observed during the demonstration to similar situations. However, using LfD in ambient systems needs adaptivity of the learning technique. We present ALEX, a multi-agent system able to dynamically learn and reuse contexts from demonstrations performed by a tutor. The results of the experiments performed on both a real and a virtual robot show interesting properties of our technology for ambient applications.     

MASACAD: A multi-agent approach to information customization for the purpose of academic advising of students

The growth and advancement in the Internet and the World Wide Web has led to an explosion in the amount of available information. This staggering amount of information has made it extremely difficult for users to locate and retrieve information that is actually relevant to their task at hand. Dealing with this problem of “information overload” will need tools to customize the information space. In this paper we present MASACAD, a multi-agent system that learns to advise students by mining the Web and discuss important problems in relationship to information customization systems and smooth the way for possible solutions. The main idea is to approach information customization using a multi-agent paradigm in combination with a number of aspects from the domains of machine learning, user modeling, and Web mining.     

Synthesizing User Centered and Designer Centered IS Development Approaches Using General Systems Theory

This paper uses general systems theory to provide an expanded view of information systems in organizations. Three general viewpoints and corresponding approaches to information systems development are identified. The designer centered or American approach to information systems development is based on a functionalist perspective of information systems and a problem solving orientation. The user centered or European approach to information systems development takes an expanded view of information systems that specifically considers humans and recognizes their aspirations and goals and uses a democratic, participative approach to develop systems in an effort to produce an improved workplace and a better quality of worklife for users. A third viewpoint on information systems development, business process centering, is identified that further expands the components of the system to include the set of integrated tasks that provide value to the customer. We define a new development approach that combines the strengths of these approaches based on general systems theory, business process centering, and a measurement and control system.     

User-centered approach to adaptive interfaces

Both adaptive and adaptable user interfaces are intended to fit the needs of individual users and their tasks better. A problem with these interfaces is that users must have and use additional knowledge, either to understand the automatic, system-driven adaptations or to adapt the interface on their own. Beyond these two extreme approaches, an automatically self-adapting system and a user manually adapting the system, the approach introduced in this paper strives for a third option, in which users are able to tell the system how to adapt itself. Accordingly, methods include adaptive adaptation (i.e. modifying the adaptation strategies) and implicit adaptation (i.e. changing the underlying models). The applicability of these findings is illustrated in the context of an adaptive action prompting environment.     

基于本体的需求自动获取

以企业信息系统为研究背景 ,提出了一种基于本体的需求获取方法 ,该方法用企业本体和领域本体为基本线索 ,引导领域用户全面描述现实系统 ,并通过重用领域需求模型 ,构造应用软件需求模型 .这种方法的主要特点是 :用领域用户可以理解的语言与他们交互 ,让他们能积极地参与需求获取活动 ;需求获取在模型的制导下完成 ,利于保证需求获取的完整性和一致性 ;在多种知识的支持下 ,自动完成对现实系统的理解和目标系统需求模型的构造 .该文将以该方法的总体结构为主线 ,分企业本体和领域本体的结构以及目标系统需求模型的构造两大部分 ,阐述这种方法 .     

Adaptive systems: from intelligent tutoring to autonomous agents

Computer systems which can automatically alter aspects of their functionality or interface to suit the needs of individuals or groups of users have appeared over the years in a variety of guises. Most recently, attention has focused on intelligent interface agents, which are seen as specialised, knowledge-based systems acting on behalf of the user in some aspect of the interaction. Similar requirements for automatic adaptation have been noted in intelligent tutoring systems, natural-language systems and intelligent interfaces. The paper brings together the research which has emanated from a number of backgrounds, and provides a unifying perspective on adaptive systems in general. An architecture for adaptive systems and a methodology for their development are presented. The paper also describes software support for producing adaptive systems, and offers some experimental evidence to justify both the desirability and feasibility of exploiting an adaptive system approach to human-computer interaction     

Coevolution of variability models and related software artifacts

Variant-rich software systems offer a large degree of customization, allowing users to configure the target system according to their preferences and needs. Facing high degrees of variability, these systems often employ variability models to explicitly capture user-configurable features (e.g., systems options) and the constraints they impose. The explicit representation of features allows them to be referenced in different variation points across different artifacts, enabling the latter to vary according to specific feature selections. In such settings, the evolution of variability models interplays with the evolution of related artifacts, requiring the two to evolve together, or coevolve. Interestingly, little is known about how such coevolution occurs in real-world systems, as existing research has focused mostly on variability evolution as it happens in variability models only. Furthermore, existing techniques supporting variability evolution are usually validated with randomly-generated variability models or evolution scenarios that do not stem from practice. As the community lacks a deep understanding of how variability evolution occurs in real-world systems and how it relates to the evolution of different kinds of software artifacts, it is not surprising that industry reports existing tools and solutions ineffective, as they do not handle the complexity found in practice. Attempting to mitigate this overall lack of knowledge and to support tool builders with insights on how variability models coevolve with other artifact types, we study a large and complex real-world variant-rich software system: the Linux kernel. Specifically, we extract variability-coevolution patterns capturing changes in the variability model of the Linux kernel with subsequent changes in Makefiles and C source code. From the analysis of the patterns, we report on findings concerning evolution principles found in the kernel, and we reveal deficiencies in existing tools and theory when handling changes captured by our patterns.     

一种软件缺陷模式自定制方法

软件缺陷是导致软件不可靠的根本原因,提高软件可靠性的关键在于减少软件缺陷。基于缺陷模式的代码分析技术根据预先设定好的缺陷模式对待测代码进行缺陷分析,这种缺陷分析具有使用简单、查找速度快等优点,是近年来静态代码分析技术中发展比较迅速的新技术。但是目前基于这种分析技术的大多数工具并没有为用户提供足够易用、高效的扩展方式以扩充其缺陷检测能力。本文出了一种支持用户定制语法相关缺陷模式的测试方法及系统,该方法能够让用户根据实际情况需要对缺陷模式进行定制,目的是检测程序代码中是否包含语法相关的缺陷。     

基于极端评分行为的相似度计算

随着互联网技术的迅猛发展,互联网信息急剧增长,信息过载问题愈发凸显。面对海量的互联网信息,用户往往需要耗费大量的时间来搜索所需的信息或产品,而搜索的解往往受到制约。为解决信息过载问题,推荐系统应运而生。推荐系统根据用户的历史行为推测其需求、兴趣等,将用户感兴趣的信息、产品等推荐给用户。作为推荐领域中一类重要的推荐方法,基于记忆的协同过滤方法通常依据用户或产品的近邻信息来构造评分预测函数,其核心在于准确度量用户或产品之间的相似度。传统的相似度量,如皮尔逊、余弦及秩相关系数等,通常只考虑了用户之间的线性关系;而启发式相似度如基于3个特殊因子的PIP相似度及其改进方法,则只刻画了用户之间的非线性关系。事实上,在推荐系统中,就用户之间的相似关系而言,仅用线性或是非线性函数来度量均是不准确的。为了更为精细地刻画用户之间的相似程度,文中提出了基于非线性函数的用户极端评分行为的相似程度度量指数,通过将该指数融入传统的线性相关系数,构造了一个考虑极端评分行为的新的相似度。为验证该方法的有效性,基于Ml(100k)和Ml-latest-small两个数据集,将其与传统相似度以及启发式相似度进行比较,结果显示基于极端评分行为相似度的协同过滤方法在MAE和RMSE指标上能够获得更好的表现。     

Enhancing Workflow Management in the Manufacturing Information System of a Small-Medium Enterprise: An Agent-Based Approach

One shortcoming of manufacturing information systems is their inability to integrate and to enhance different information and related functionalities, such as those found in workflow management. Software agents, once added as a new software layer to an existing system, can overcome this problem. Of the fields applying software agent technology, manufacturing, and especially workflow management, is perhaps the most promising for the development of distributed systems. This potential is reflected in the several ongoing research projects that focus on workflow management and share the final aim of integrating and coordinating plant and business activities.The approach presented in this paper can be regarded as an agent-based architecture applied to an existing workflow management system in order to manage new functionalities, e.g., customer relationship management in electronic commerce. This approach is particularly suitable for small medium enterprises with simple manufacturing information requirements and simple or nonexistent computer based workflow management.The model and some important features of system implementation, such as the knowledge modeling graphical user interface, the communication model, and a simple practical example of the architecture's use, are described.     

Model-Driven Interactive System Design for Therapy Robots

Physiotherapy using intelligent robots is emerging as a new approach to recovery for many stroke patients. Although therapy robots have a strong potential in dealing with therapeutic and other medical applications, they have not been fully utilized in everyday therapy activities due to concerns over safety and the lack of friendly robot user/patient interaction models. From the viewpoint of software engineering, a user-centred design based on UML (Unified Modelling Language) has been known to be one of the best solutions to satisfy usability since the design process relies heavily on the analysis of users and their tasks to reach their goals. Therefore, a model-driven approach to interactive system design via UML for therapy robots is needed to make them usable in the real world. This paper proposes such approach and introduces a new graphical notation that describes user interface elements and the methods of connection with hardware/software objects. With the proposed abstract interaction models, prototyping interactive systems can be made faster and allows for their evaluation by users and system developers before implementation in order to improve usability from the perspectives of users and system developers.     

Adaptive hypertext navigation based on user goals and context

Hypertext systems allow flexible access to topics of information, but this flexibility has disadvantages. Users often become lost or overwhelmed by choices. An adaptive hypertext system can overcome these disadvantages by recommending information to users based on their specific information needs and preferences. Simple associative matrices provide an effective way of capturing these user preferences. Because the matrices are easily updated, they support the kind of dynamic learning required in an adaptive system.HYPERFLEX, a prototype of an adaptive hypertext system that learns, is described. Informal studies with HYPERFLEX clarify the circumstances under which adaptive systems are likely to be useful, and suggest that HYPERFLEX can reduce time spent searching for information by up to 40%. Moreover, these benefits can be obtained with relatively little effort on the part of hypertext authors or users.The simple models underlying HYPERFLEX's performance may offer a general and useful alternative to more sophisticated modelling techniques. Conditions under which these models, and similar adaptation techniques, might be most useful are discussed.     

面向定制的工程CAD系统模板技术

工程CAD可以通过提供定制功能以满足日益增长的个性化需求，并适应不同企业，行业的标准和惯例，文中在以往模板技术研究的基础上，借鉴面向规模定制设计的方法，设计了面向定制的模板技术实施方案，（1）参照功能需求的分解树，面向多个用户需求提炼功能模式；（2）建立工程信息的多层结构，分析应模块；（3）为特定模块设计多视图的模板，保联工程CAD的可定制，可复用以及定制对象同系统的无缝集成，最后介绍了PDSOFT系列中的模板技术应用。     

Configuration for mass customization: how to extend product configuration towards requirements and process configuration

In order to develop mass customization, many companies use configuration software to customize their products. Although many studies already exist about Product Configuration, Requirements and Process Configuration have not been studied in detail. As all these three aspects must be considered for mass customization, the aim of this paper is to show how Product Configuration, when considered as a constraint satisfaction problem, can be extended upstream towards Requirements Configuration and downstream towards Process Configuration. Product Configuration basics are first reviewed thanks to a constraint based approach, and an analysis of industrial configuration situations is done in order to clarify mass customization needs in terms of configuration. Then upstream Requirements Configuration and downstream Process Configuration are defined and generic models are proposed. It is shown that the proposed elements allow a global and consistent flow of configuration activities. A detailed example illustrates the different configuration problems and a discussion terminates the paper.     

基于多视图的特征模型定制

特征模型是捕获特定领域可复用软件需求的一种重要技术手段。对特征模型的复用通常采用定制的方式,通过定制使其适应领域内不同系统的特定需求。特征模型定制的一个难点在于定制过程往往涉及众多的利益相关者,而这些利益相关者的关注点各有不同。由于特征模型是针对整个领域的需求而组织的,特定利益相关者的关注点可能散布在整个特征模型中且可能与其他利益相关者的关注点相互交织,这为特定利益相关者的定制工作带来一定的困难。为此,文章提出一种基于多视图的特征模型定制方法,针对不同的利益相关者将其所关注的散布在整个特征模型中的信息聚类到不同的视图中,并提供一种约束一致性维护机制,方便相应的利益相关者的定制活动。     

Using intentional models for the interface design of multi-level systems

In this paper, it is argued that the design of computer interfaces for complex, multi-layered systems needs to take into account the differing intentional models that are held by different types of users of such systems, and that there is a strong correlation between the job roles of individuals and the level of abstraction of the mental models held by such users. An approach to the analysis and design of complex multi-layered systems based on the analysis of job roles to elicit such models is suggested and linked with other techniques of task analysis and object-oriented analysis and design. The methodology is illustrated with the interface analysis for an automatic environmental chemical analyser.     

Collaborative error-reflected models for cold-start recommender systems

Collaborative Filtering (CF), one of the most successful technologies among recommender systems, is a system assisting users to easily find useful information. One notable challenge in practical CF is the cold start problem, which can be divided into cold start items and cold start users. Traditional CF systems are typically unable to make good quality recommendations in the situation where users and items have few opinions. To address these issues, in this paper, we propose a unique method of building models derived from explicit ratings and we apply the models to CF recommender systems. The proposed method first predicts actual ratings and subsequently identifies prediction errors for each user. From this error information, pre-computed models, collectively called the error-reflected model, are built. We then apply the models to new predictions. Experimental results show that our approach obtains significant improvement in dealing with cold start problems, compared to existing work.     

Embryonic approach to the development of information systems

Prototyping in information systems (IS) development has recently shown increased benefits. In principle, the prototyping process provides users with more opportunities to improve their work, to verify that their needs are provided for, and that the terms used in the interface of the designed system are consistent with those in use in their work. As a result, they should be highly motivated to participate in an IS development process.However, certain drawbacks inherited from traditional prototyping in industrial production could limit the use of this approach in IS development. Some problems are identified in this paper, such as: (1) product-oriented thinking; (2) feedback delay; (3) the preoccupation of designers with respect to the experimental approach; (4) problems arising from the users' participation being indirect, and (5) negative attitudes towards contradiction. This paper proposes an organic approach, the ‘Embryonic Approach’ (EmA), in order to explore the full potentialities of prototyping in IS development. This approach is based on two fundamental elements; an adaptive and expandable kernel-structure, and a built-in communication mechanism.