Preparing knowledge on urban simulation computation is necessary to help participants build consensus, reduce expertise gaps, and guide participatory sustainable urban planning. Knowledge co-creation is an effective way to prepare the needed knowledge related to urban simulation computation. However, the procedural and operational information that can help instruct the implementation of urban simulation is extensively hidden in the implementation processes of urban simulation in various forms (e.g., dialog records, configuration parameters, and model operations). Difficulties remain in extracting this implicit information and synthesizing the related knowledge. Therefore, a strategy is proposed to support the co-creation of knowledge during the urban simulation computation. In this strategy, the structural knowledge expression methods are first designed to support information extraction and knowledge synthesis. Based on interaction tracking and natural language understanding techniques, the related information can be obtained from simulation computation processes. Using this information, four main types of knowledge can be generated, optimized and visualized to assist collaborative urban simulation practices. This strategy was implemented in an online collaboration prototype system and verified with two sustainable urban case studies involving the simulation of urban noise environments and solar radiation assessment of photovoltaic noise barriers in cities. The results show that the knowledge co-creation can be effectively implemented by using the information extracted from simulation computation processes, which can benefit broader collaboration in urban simulation and sustainable urban planning.

: Modelling is an effective method to simulate geographic phenomena and processes and solve geographic problems. To date, many experts and scholars have constructed massive geographic simulation models to meet the requirement for simulation of different geographical scenarios. Meanwhile, collaborative modelling and integration are becoming more important for complex geographic problem solving. In order to make existing models better serve various geographic studies, model sharing and reuse have become hot topics nowadays. Due to their heterogeneous nature, diverse models have varying methods of description, different structures and access arrangements. It’s hard to locate, share and reuse models in a common way. To alleviate these difficulties, research has been undertaken to improve model sharing and reuse for different levels and kinds of requirements, such as model knowledge acquiring, model building and model use. For example, Maxwell and Costanza designed a modular modeling language (MML) (Maxwell and Costanza, 1997) to describe the cognitive problems of models. The CSDMS platform uses standardized names to describe the input and output of the model (Overeem et al., 2013). For the sharing of models, Gehlot et al. (2006) proposed the sharing of a geographical processing chain based on the network. HydroShare platform is based on Open Archive Initiative's Object Reuse and Exchange (ORI-ORE) standards to share model resources (Lagoze et al., 2007; Horsburgh et al., 2016). This paper summarizes the knowledge from the model construction and using processes and divides them into four knowledge entries: model item, conceptual model, logical model and computable model. These items can serve various users' needs for model recognizing, model constructing, and model invoking by providing a structural description of the fundamental data, mechanisms, structures, and operating processes of models. Finally, we provide a web system that demonstrates how various levels of model knowledge entry

Integrated geographic modelling and simulation is a computational means to improve understanding of the environment. With the development of Service Oriented Architecture (SOA) and web technologies, it is possible to conduct open, extensible integrated geographic modelling across a network in which resources can be accessed and integrated, and further distributed geographic simulations can be performed. This open web-distributed modelling and simulation approach is likely to enhance the use of existing resources and can attract diverse participants. With this approach, participants from different physical locations or domains of expertise can perform comprehensive modelling and simulation tasks collaboratively. This paper reviews past integrated modelling and simulation systems, highlighting the associated development challenges when moving to an open web-distributed system. A conceptual framework is proposed to introduce a roadmap from a system design perspective, with potential use cases provided. The four components of this conceptual framework - a set of standards, a resource sharing environment, a collaborative integrated modelling environment, and a distributed simulation environment - are also discussed in detail with the goal of advancing this emerging field.

Representational state transfer service(RESTful service has gained widespread acceptance as a simpler alternative to SOAP/WS-* Web services.Acknowledging the hypermedia nature of RESTful service,the response of the RESTful usually contains links that can be used as the engine to fire new resource request.The complex internal state transitions in the service request/response process can lead to bigger privacy risks.How to accurately depict privacy actions in this dynamic interactive context driven by the hypermedia is one fundamental issue in RESTful service privacy protection research.In this paper we present a RESTful application state privacy model based on single-event finite automaton and discuss the automatical transformation method from RESTful service description to that formal model.We establish the privacy action meta-model to depict the atomic privacy action with accurate semantics and formally define some kernel elements of RESTful service and the relationship among them.We then discuss how to transform the RESTful service resources to the corresponding privacy actions.In addition,we propose a new data structure called resource link mapping tree to represent the relationship between the RESTful service resources and links.A transformation method based on the resource link mapping tree is introduced to generate the corresponding privacy actions from the RESTful service definition and further generate the formal single-event automata with the algorithm considering both protocol links and hypermedia links.We finally use a case-study of e-Bay "add to watch list" service and the experiments based on our prototype tools to show the feasibility of our approach.

With the increasing demands for cloud resources, the task to keep it balanced with supply at all times becomes especially challenging. However, most of existing mechanisms focus on auction-based allocation of cloud resources rather than balancing the demands for cloud resources. In order to deal with this problem, this paper presents the problem of cloud resources consumption shifting between two different time intervals in a formularized manner, and then puts forward a cloud resources consumption shifting scheme with three-tier architecture. Users participating in the scheme, however, are motivated to get extra rewards by shifting certain consumption quantity from high to low demand time intervals. So, taking into account the fact that value ranges of individual shifting costs vary with different geographic areas, this scheme first allocates rewards to agencies in different geographic areas in the way of equilibrium, and then applies a strictly proper rule to reward users according to their contributions. In addition, the paper theoretically proves that the scheme is equipped with economic properties such as equilibrium, individual rationality, budget balance, and truthfulness. Finally, extensive simulation results show that the proposed scheme owns the resources shifting efficiency and computational traceability, and it can generate higher and more stable social rewards than the common scheme with two-tier architecture.

Group-buying has emerged as a new trading paradigm and became more attractive. Through it, both sides of the transaction will benefit from the group-buying: buyers enjoy a lower price and sellers receive more demanding orders. In this paper, we investigate an auction mechanism for cloud resource allocation with time discounting values via group-buying, called TDVG. TDVG consists of two steps: winning seller and buyer selection and pricing. In first step, we choose winning seller and buyer in a greedy manner according to some criterion, and calculate the payment for each winning seller and buyer in second step. Rigorous proof demonstrates that TDVG satisfies the properties of truthfulness, budget balance and individual rationality. Our experiment results show that TDVG achieves better total utility, matching rate and commodities utilisation than the existing works.

To solve the problem that atomicity and consistency cannot be guaranteed to satisfy at the same time when ACID properties are relaxed in Web services composition transaction .A Deterministic Finite State Automata (DFA) based ap-proach is presented to check the conceptual consistency in services composition .Different from most previous works which keep application consistency by runtime monitoring and coordination ,this approach uses DFA to model interaction behavior and exception handling process of services composition at design stage .The DFA based approach analyzes the key conditions and properties to satisfy the conceptual consistency ;and further ,it proofs the theorem to determine the conceptual consistency in service composition .Finally ,by analyzing the deployment framework of services composition consistency detec-tion ,the feasibility of our approach has been illustrated .

云计算中应用分层、服务外包以及数据的分布存储等特性引发了隐私保护的新挑战.如何刻画不同服务提供者的隐私需求,并保证不同参与方隐私需求在全局应用上一致无冲突是云计算隐私保护的一个核心问题.在对隐私需求的分类和建模目标系统分析后,提出了一种综合考虑了数据、角色和目的的层次结构,并支持时序约束表达的声明式隐私需求描述语言DPPL.为验证不同隐私需求间的一致性,给出了该语言的形式化语义及对应的形式化建模算法.考虑到传统形式化验证由于空间爆炸而带来的实用性限制,进一步结合隐私活动的特征提出了隐私需求模型的约简方法.最后,通过实例分析和原型工具检验了所提出方法的可行性,并对于该方法目前尚存在的限制和未来工作进行了讨论.

Market mechanism constitutes an efficient scheme for the allocation of cloud-based computing resources with the view of virtual machines. The volume discount model is a new kind of dynamic pricing economic model on the Internet, which makes the users can form a group through Internet to get the volume discount, i.e., the more units that are bought together, the lower the price of the resource being provided becomes. In this paper, we consider the virtual machine allocation problem in clouds with group buying pricing scheme and propose TVDA, a Truthful Volume Discount Auction to allocate cloud virtual machine instances by taking advantage of the volume discount. TVDA possesses good properties such as truthfulness, individual rationality, ex-post budget balance, system efficiency, and computational tractability. Numerical results are presented to demonstrate the effectiveness of the proposed scheme.

Cloud computing, the architecture which shares dynamic heterogeneous characteristics in the cross-layer service composition, has affected traditional security, trust and privacy mechanisms which are mainly based on data encryption and access control. Approaches that can support accurate privacy requirement description and verifiable compliance between the privacy requirement and system practice need to be developed to fit this new paradigm. To tackle the issues of privacy requirement modeling and verification in cloud computing, a framework that supports model checking consistency, entailment and compliance with the formal definition of privacy requirements and privacy model of cloud application is proposed. This paper provides an overview of the scientific research problem, approaches to solve the problem and ways to evaluate the solution found by the research related PhD thesis. Keywords—Cloud computing, privacy requirement, model checking, formal model

SummaryWe study the cloud resource auction problem where users can bid for resource bundle containing heterogeneous types of virtual machines, and providers allocate virtual machines to their users through group price model. Compared with fixed price model, which is not always the best approach for trading resources as its economically inefficient and inflexible nature, the group price model possess the better flexibility and monetary benefits for auction participants (e.g., cloud providers and users). The proposed auction mechanism strategy‐proof group buying‐based auction mechanism, which formulates the problem of virtual machine allocation in clouds as a combinatorial auction problem, and holds some important property such as individual rationality, ex‐post budget balance, and truthfulness, meanwhile guaranteeing efficiency in both the provider's revenue and system efficiency. Extensive simulation results show that the proposed mechanism yields the allocation efficiency and computational tractability compared with the mechanism with fixed price model. Copyright © 2015 John Wiley & Sons, Ltd.

This paper introduces function modules and algorithm of crew recovery system. Then discusses the application of Del?phi, Visual C++,MATLAB union programming techniques and methods in crew recovery system. We analyze the unique advan?tage of union programming technology in system development. At last the application of union programming technology is given.

为了解决由于缺乏谓词约束表达式的建模和分析带来的业务流程执行语言（business process execution language,BPEL）中路径分析不准确问题,提出了一种针对BPEL中XPath表达式的谓词约束分析和建模方法,并在此基础上提出了BPEL可行路径的分析算法.与以往BPEL建模中大多仅考虑结构化行为不同,该方法系统分析了数据封装对执行路径的影响.该方法综合考虑BPEL中表达式的语法结构以及结构化活动对BPEL中变量的影响,采用扩展行为影响的变量结构树对BPEL中原子数据表达式进行建模,并进一步考虑了复合谓词表达式的建模和基于此模型的BPEL可行路径分析方法.最后,结合案例分析了该方法的可行性.

针对已有服务适配方法大多只考虑两个服务交互的简单场景且不支持BPEL代码的自动生成的问题,提出了一种面向多个服务交互的适配器自动生成方法.在通过对有限自动机进行扩展以建模服务的签名和行为信息的基础上,给出了分析多个服务之间相容性的方法.对于不相容的情况,定义了适配器模型的语法和操作语义,给出了适配器模型的自动生成算法,并对得到的适配器模型进行约简以支持适配器BPEL代码的自动生成.通过一个实例分析说明本文所提方法的可行性.

Market mechanism constitutes an efficient scheme for the allocation of cloud-based computing resources with the view of virtual machines. However, most of the existing mechanisms commonly use fixed price model and ignore flexible price model for the cloud providers. In this paper, we formulate the problem of virtual machine allocation in clouds as a combinatorial auction problem and propose a mechanism with group price to solve it, in which the cloud provider can express the discount price for each kind of traded virtual machine instances. We investigate the theoretical properties of the proposed mechanism including individual rationality, ex-post budget balance, and truthfulness. Extensive simulation results show that the proposed mechanism yields the allocation efficiency and computational tractability while generating higher revenue for the cloud providers than the mechanism with fixed price.

RESTful Web service has become a primary method to publish services in cloud computing, due to its lightweight and specific semantics. However, because RESTful Web service only support synchronous interaction, it is difficult of using synchronous composition to meet the requirement of the complex business process. Therefore, the paper proposed a callback based asynchronous interaction approach under REST style. The approach enables the composition of both synchronous and asynchronous RESTful Web services by extending the BPEL meta model. The architecture of the execution engine for the extended BPEL was designed and implemented as well.

In order to improve the performance of Chinese text categorization,a Chinese text categorization method was proposed based on evolutionary hypernetwork.A Chinese Lexical Analysis System(ICTCLAS) was employed to take the words with parts of verb,noun and adjective as candidate features.The χ2-test method was used to realize feature selection,and the feature weight was calculated by Boolean weighting.The preprocessed data sets were divided into training set and testing set.A hyperedge replacement strategy was used to train hypernetwork classification model for classifying testing sets.The classification performances of the hypernetwork models with different orders were analyzed and compared with traditional KNN and SVM.The experimental results show that the proposed scheme can achieve 87.2% and 72.5% of macro precision,86.9% and 70.5% of macro recall,87.0% and 71.5% of macro F1 for Fudan University corpus and Sohu corpus,respectively.As an efficient tool for Chinese text classification,the proposed scheme is close to or better than KNN and SVM classification methods.

Verifying whether Web services composition satisfies with privacy requirement is a hot spot for privacy protection currently. However,little research focuses on behavioral privacy requirement. This paper proposes an approach to describing behavior-oriented privacy requirement that limits temporal relationship betwween private data access and service invocation in order to lay the foundation for formal verification of the requirement. Firstly,this paper introduces the behavior-oriented privacy policy model taking into account features like purpose and obligations,which is expressed with six- tuple. Then,it presents the definition with extensible markup language(XML)schema,corresponding with the model,and achieves the transformation of privacy policies from the natural language to XML document. Finally,the effectiveness of the proposed method is illustrated through a case.

To detect conflict of feature model resulted from evolution of feature model,this paper proposed a method of ontology-based evolving feature model consistency verification.At first,it analyzed evolving feature model and built ontology-based feature model meta-model by adopting ontology.Secondly,according to the feature meta-model,it built domain model for domain of online shopping and it cut into a product feature model with specific application needs.Thirdly,it verified the consistency of the product feature model with Jena inference engine loading the rules and the product feature model.Detecting conflicts,it used evolution strategy to eliminate the conflicts.At last,the result of a case in the paper illustrates the effectiveness of the proposed method.

As software trustworthiness has become an important aspect in software engineering research,more and more researchers have focused on Web service trustworthiness evaluation while Web service has been the main form in software resource.Current research about Web service trustworthiness has concentrated on QoS attributes evaluation of single service rather than on Web service composition trustworthiness evaluation.This paper presented a general model of atomic service trustworthiness evaluation and an approach for composite service trustworthiness evaluation based on the weight of atomic services executed in composite service and the structure of composite service.Finally,we described the experiment of the approach by using a detailed case in a real online shopping.