DynaFlow: a dynamic inter-organisational workflow management system

The expansion of web service provider's number over the web has motivated the research community to invest in web service discovery area. However, in order to efficiently identify appropriate services, web services requesters should express their requests in rich, standard and machine-readable manner. In this context, we propose the use of a Service Request Template based on SAWSDL and WS-Policy standards. We use SAWSDL language which constitutes an extension of WSDL to express both functional and semantic needs, while we use WS-Policy framework to specify both non-functional requirements and user's preferences. We think that the proposed template would make it possible to overcome problems due to the heterogeneity between web services requests and published web services when executing discovery process. To perform efficient service discovery, we develop a structure-based matching algorithm that offers three mechanisms: semantic, data types and policy matching.

This paper describes a system for supporting the user in the discovery of semantic Web services, taking into account personal requirements. Goal is to model an ad-hoc service request by filtering semantic specifications rather than the exploitation of strict syntax formats. Adaptive agent-based techniques help the user to compose his Web service request, exploiting the semantic annotation of the browsed Web resources. This annotation reflects concepts or ontological terms that are relevant for the user services request formulation. Once the request is formulated, the system returns the list of semantic Web services that match the query input and output concepts.

A semantic web service environment for B2B and B2C auction applications within extended and virtual enterprises

Virtual enterprise is a temporary network of independent companies or enterprises that can quickly bring together to fulfill a value-added task. With the development of Web service technologies, the enterprise business systems can be encapsulated as Web services. Establishing a virtual enterprise is actually a process of Web services composition. As more and more Web services are available, many Web services with different quality of service (QoS) can be found for tasks of the composite Web service. Thus, a significant research problem in Web service composition is how to select the correct Web services for tasks such that the composite Web service gives the best overall quality. In this paper, we propose an approach to achieve Web services selection efficiently with excellent comprehensive quality. Firstly, a comprehensive evaluation model based on generic QoS (GQoS) and domain QoS (DQoS) of composite Web service is established. Secondly, a novel optimization algorithm named culture max–min ant system (C-MMAS) is constructed to solve the problem of Web service selection based on DGQoS. Simulations show that when used in Web service selection, C-MMAS is better than ant colony optimization algorithm and MMAS in efficiency.

While Web service models become increasingly popular and many service providers start to offer all kinds of Web services, the quality of service (QoS) for Web services has become an important factor for service requesters to consider during the selection process of appropriate Web services. In this paper, we present an evaluation and selection framework (CosmosQoS) for QoS-required Web services. A novel architecture and reputation appraisal model to monitor, store and evaluate the physical usage and post-condition of requested Web services in a requester-located network is proposed to better support service requesters such that they can select suitable Web services based on their QoS requirements, trustworthiness of Web services, and effect of network connection and configuration between service requesters and providers.

Web service selection based on quality of service (QoS) has been a research focus in an environment where many similar web services exist. Current methods of service selection usually focus on a single service request at a time and the selection of a service with the best QoS at the user's own discretion. The selection does not consider multiple requests for the same functional web services. Usually, there are multiple service requests for the same functional web service in practice. In such situations, conflicts occur when too many requesters select the same best web service. This paper aims at solving these conflicts and developing a global optimal service selection method for multiple related service requesters, thereby optimizing service resources and improving performance of the system. It uses Euclidean distance with weights to measure degree of matching of services based on QoS. A 0-1 integral programming model for maximizing the sum of matching degree is created and consequently, a global optimal service selection algorithm is developed. The model, together with a universal and feasible optimal service selection algorithm, is implemented for global optimal service selection for multiple requesters (GOSSMR). Furthermore, to enhance its efficiency, Skyline GOSSMR is proposed. Time complexity of the algorithms is analyzed. We evaluate performance of the algorithms and the system through simulations. The simulation results demonstrate that they are more effective than existing ones.

Firstly aiming at pure agent couldn’t construct virtual enterprise process in real-time, the paper puts forward using multi-intelligent-agent virtual enterprise architecture to implement DAE. Secondly with the help of complex data type in BPDL, STR and SOR, the system implements the business process specification and management. And then multi-intelligent-agent such as PUA, DRA, RPA, and so on interoperate with each other commonly establishes the dynamic VE WFMS. Finally the paper sums up the merits and faults of this system.

Automatic container scaling in Kubernetes plays an important role in handling incoming requests from web application users. This article analyzes the stages of container scaling, their initialization and subsequent software launch. In order to achieve low latency of user requests in the case of dynamic load, the analysis of the process of automatic scaling of containers and the factors that will affect the scaling process was carried out. Having a full understanding of the processes and mechanisms by which scaling takes place, it became possible to develop a method and strategy for cleaning obstacles that slow down the autoscaling process itself and at the same time preserve the necessary properties of the existing scaling. Acceleration of scaling of containers, which will directly affect the speed of web services, becomes possible precisely because of the elimination of the delay in automatic scaling of containers. The work considered scaling optimization using not only container pre-creation networks, but also the use of container images, which enable the sharing of linked libraries in memory and the extension of Kubernetes’ declarative configuration management approach for parallel creation of multiple container instances. Based on the obtained research results, a method for optimizing the automatic scaling of containerized applications by eliminating the delay during a cold start has been developed. This latency manifests itself in the case of microservice autoscaling, where Kubernetes is expected to scale containers horizontally by creating additional replicas to the required number to handle the required traffic from the outside. The delay caused by the autoscaler affects the processing time of the user’s web service requests.

The article presents a problem solution of plant cultivation automation using the Internet of Things concept. Using an intelligent system to control a hydroponics installation allows you to increase the energy efficiency of growing plants by introduction of intelligent technologies. The application of the Internet of Things concept allows a more qualitative approach to the search and application of methods of rational modern production. This concept allows the collected data to be Wi-Fi transferred from the microcontroller to a computer via a server, which is very effective in environments with large number of sensors. In this case, both time and material costs per share of production are significantly reduced. The work identified the requirements for a recording and control device in an intelligent system that connects to the Internet for further data processing, configuration and execution of the operating mechanism, and stages of operation of the growing system. Part of the control system for a plant cultivation complex using microcontroller devices available on the market, such as ESP, is considered. A constructive functional design of the device was developed. In addition, it was determined that the intelligent system contains the following modules: thing (the physical controller itself - device, peripherals), network (a network of devices and communication channels that ensure the transfer of information according to network protocols), cloud (includes a server that processes client, storage and web service requests). A description of the first module is given, which includes the main controller board with an esp12e microcontroller. The second module contains printed circuit boards for the power supply and controller, which were designed and laid out using the EasyEDA web service. For the third module, three-dimensional models of the power supply and main board were obtained in the EasyEDA web service environment.

chapter 3 - Web Services

Web services are increasingly utilized in people’s daily lives to achieve various functionalities. Trustworthiness has become a critical factor for service provision and governance. The lack of effective trust establishment mechanisms impedes the deployment of diverse trust models for web services. One important issue is that collaborating organizations need mechanisms to bridge extant relationships among cooperating parties. Meanwhile, a trust establishment mechanism for web services must ensure privacy and owner control at all times due to the subjectivity of trust relationships. As an alternative and complementary approach to direct trust establishment, we describe an indirect trust establishment mechanism to bridge and build new trust relationships from extant trust relationships with privacy protection. Another issue is the lack of mechanisms that can directly establish trust relationships with privacy-preserving capabilities for web services. Current web service technologies encourage a service requester to reveal all its private attributes in a pre-packaged digital credential to the service provider to fulfill the requirements for verification. This may lead to privacy leakage. We propose a mechanism whereby the service requester discovers the service provider’s requirements from a web service policy document, then formulates a trust primitive by associating a set of attributes in a pre-packaged credential with a semantic name, signed with the requester’s digital signature, to negotiate a trust relationship. Thus the service requester’s privacy is preserved because only those attributes required to build a trust relationship are revealed.

The development process of Web services needs to focus on the modeling of business processes rather than on low-level implementation details of Web services, and yet it also needs to incorporate the support for frequent business changes. This chapter presents the UML-based Rule Language (URML) and REWERSE Rule Markup Language (R2ML), which use reaction rules (also known as Event-Condition- Action rules) for modeling Web services in terms of message exchange patterns. Web services that are being modeled in this way can easily be integrated in the wider context of modeling orchestration and choreography. In order to achieve proposed solution, we have developed a plug-in for the Fujaba UML tool (so called Strelka) and a number of model transformations for round-trip engineering between Web services and reaction rules. Also, the paper presents mappings of models of Web services with reaction rules into the Drools rule language, thus enabling the run time execution semantics for our rule-based models.

Nowadays, large number of cloud-based techniques have been used in industrial control systems (ICS), which also brings many security threats. The emergence of security-aware industrial control has paved the way of security-aware scheduling in cloud-based industrial applications. Actually, most cloud-based industrial applications are time sensitive, which need real-time processing. Edge cloud computing paradigm extends the computing ability of traditional cloud model with low-latency local resources. Thus, heterogeneous clouds that consist of both centralized resources and edge resources may be a promising resource model to provide both scalable and low-latency resources for cloud-based industrial applications. In view of these challenges, in this article, we propose a security-aware dynamic scheduling method for real-time resource allocation in ICS. First, a three-level security model is designed for both tasks and cloud resources in ICS, and a two-tier heterogeneous cloud architecture is introduced. Accordingly, a security-aware scheduling method based on distributed particle swarm optimization is presented for resource allocation with security concerns. To deal with the dynamics of edge resources and the mobility of mobile industrial applications, a dynamic scheduling mechanism based on dynamic workflow model is proposed for real-time optimization. Experimental results validate that the scheduling control policy proposed in this article can achieve a good balance between scheduling performance and security performance.

Web services provide a standard means of interoperating between different software applications, running on a variety of platforms and/or frameworks. While the concepts of Web services are aimed at providing a standard means to support interoperable machine-to-machine interaction over a network, they do not solve the problem of between service requesters and providers. A trusted component is defined as a reusable software element possessing specified and guaranteed property qualities. The highly reusable nature of a Web service emphasizes the need for a trust ensuring mechanism between the requester and the provider of the service. The focus of this paper is to suggest a fortified Web services architecture introducing the concept of contracts to increase the level of between the requester and the provider of the requested service. In order to achieve this goal a new language is introduced into the fortified Web services architecture: WS-Contract. WS-Contract is a machine-processable specification of the Web service semantics, formally supporting the different levels of contract information. It defines the pre-and post conditions of the Web services interface, the synchronization policy of the service and the QoS parameters that should be maintained between the requester agent and the provider agent. WS-Contract relies, wherever possible, on existing Web services standards to build the necessary trust ensuring mechanism for Web services

Workflow technology has emerged as one of those technologies designed to support modeling, designing and executing business processes. One of the major limitations of current workflow management systems is the lack of flexibility to support dynamic management of workflows. In this paper, we propose a dynamic workflow management model based on web services. We integrate web services and ontology technologies to support dynamic specifying, monitoring, analyzing, designing, configuring and executing workflows. We explain the need and functionality of the main modules and interfaces of the model, and introduce its application in a case study. An important feature of this model is to support for planning and adaptive workflow management.