A dynamic grid service discovery model： TDMSD

Frequent joining and withdrawal of resources and services in a grid make dynamic discovery of grid resource and service quite difficult. In this paper, a two-dimensional model of service discovery （TDMSD） is presented for use of dynamic service discovery. Description and proof of the model and the route algorithm of service discovery are proposed. The complexity analysis and simulation results show that the TDMSD model works well.

Resource integration optimization of convenience service platforms adopting dynamic service modes in new retail

This paper analyzes the key issues of resource integration,and proposes a method for solving the problem of achieving efficient resource integration for convenience service platforms that adopt dynamic service modes.This method considers both the service level of collaborative resources under dynamic service modes,and collaborative resources’satisfaction of service modes in the resource integration.In addition,dominant factors needing the most attention during resource integration under dynamic service modes are excavated.Moreover,a model for resource integration optimization is established,and ant colony algorithm is used to solve the problem.Finally,a case is used to verify the feasibility of the method.

A feedback control mechanism for adaptive SLO maintenance in dynamic service level management

With the increasing scale of information technology(IT)service system,traditional thresholdbased static service level management(SLM)solution appears to be inadequate to meet current increasingly management requirement of SLM.Due to the stochastic service request rate,the random inherent failure and load surge of IT devices during service operating stage of large scaled IT system,service level objective(SLO)maintenance issue has become a realistic and important issue in dynamic SLM.This paper proposes a closed-loop feedback control mechanism to adaptively maintain SLO that service provider(SP)guaranteed at service operation stage.The mechanism can automatically tune the capacity of IT infrastructure according to service performance dispersion and reduce SLO violations.Considering that the tuning operations also affect service performance,fuzzy control is applied to alleviate the negative effect caused by tuning operations.In the dynamic SLM system that is applied with this mechanism compared with the traditional threshold-based solution,it is proved that the amount of SLO violations obviously decreases,the reliability of the service system increases relatively,and the resource utilization of IT infrastructure is optimized.

MAS-based dynamic web service composition formal model

Applying dynamic web services composition is one of the important schemas for solving service-oriented architecture （SOA）and service-oriented computing（SOC）.For implementing dynamic web services composition,the multi agent system （MAS）is applied to web services composition.First, the essentials of the MAS and web services composition are analyzed and their relationship is discussed.Secondly, an MAS-based architecture is designed for dynamic web services composition,and it is named as CSMWC.A Jade tool is used to implement the major components.The architecture can primarily implement syntactic level dynamic web services composition,and it gives a basis for semantic level dynamic web services composition.For specifying the correctness of the architecture,by using pi-calculus,the architecture of the MAS is formally described,and its dynamic properties and adaptability are reasoned.Finally,it demonstrates the idea proposed by the Pi4SOA tool.

A Time-Aware Dynamic Service Quality Prediction Approach for Services

Dynamic Quality of Service(QoS)prediction for services is currently a hot topic and a challenge for research in the fields of service recommendation and composition.Our paper addresses the problem with a Time-aWare service Quality Prediction method(named TWQP),a two-phase approach with one phase based on historical time slices and one on the current time slice.In the first phase,if the user had invoked the service in a previous time slice,the QoS value for the user calling the service on the next time slice is predicted on the basis of the historical QoS data;if the user had not invoked the service in a previous time slice,then the Covering Algorithm(CA)is applied to predict the missing values.In the second phase,we predict the missing values for the current time slice according to the results of the previous phase.A large number of experiments on a real-world dataset,WS-Dream,show that,when compared with the classical QoS prediction algorithms,our proposed method greatly improves the prediction accuracy.

Runtime reconfiguration of data services for dealing with out-of-range stream fluctuation in cloud-edge environments

The integration of cloud and IoT edge devices is of significance in reducing the latency of IoT stream data processing by moving services closer to the edge-end.In this connection,a key issue is to determine when and where services should be deployed.Common service deployment strategies used to be static based on the rules defined at the design time.However,dynamically changing IoT environments bring about unexpected situations such as out-of-range stream fluctuation,where the static service deployment solutions are not efficient.In this paper,we propose a dynamic service deployment mechanism based on the prediction of upcoming stream data.To effectively predict upcoming workloads,we combine the online machine learning methods with an online optimization algorithm for service deployment.A simulation-based evaluation demonstrates that,compared with those state-of-the art approaches,the approach proposed in this paper has a lower latency of stream processing.

Service Oriented Approach State of the Art

For many years, computer systems have emerged; they now occupy an important place in our daily lives. The growing needs and ever increasing use of computer systems have made application development more and more complicated, The complexity of these applications poses problems such as reuse, installation, administration and evolution of applications. The development of applications is related to the evolution of paradigms and approaches to developing them. This paper presents different approaches and paradigms of development starting with the procedural approach, coming up for service, through the component and object-oriented approaches. Also, for each of the approaches we determine the advantages and limitations.

A Software-Defined Approach to IoT Networking

It is foreseen that the Internet of Things (IoT) will comprise billions of connected devices, and this will make the provi?sioning and operation of some IoT connectivity services more challenging. Indeed, IoT services are very different from lega?cy Internet services because of their dimensioning figures and also because IoT services differ dramatically in terms of na?ture and constraints. For example, IoT services often rely on energy and CPU?constrained sensor technologies, regardless of whether the service is for home automation, smart building, e?health, or power or water metering on a regional or national scale. Also, some IoT services, such as dynamic monitoring of biometric data, manipulation of sensitive information, and pri?vacy needs to be safeguarded whenever this information is for?warded over the underlying IoT network infrastructure. This paper discusses how software?defined networking (SDN) can facilitate the deployment and operation of some advanced IoT services regardless of their nature or scope. SDN introduces a high degree of automation in service delivery and operation-from dynamic IoT service parameter exposure and negotiation to resource allocation, service fulfillment, and assurance. This paper does not argue that all IoT services must adopt SDN. Rather, it is left to the discretion of operators to decide which IoT services can best leverage SDN capabilities. This paper only discusses managed IoT services, i.e., services that are op?erated by a service provider.

Progress in high-speed train technology around the world

This is a review of high-speed train development in the sense of technology advances all over the world. Three generations of high-speed trains are classified according to their technical characteristics and maximum operating speed. Emphasis is given to the newly developed high-speed train in China, CRH380. The theoretical foundations and future development of CRH380 are briefly discussed.

Dynamic data packing towards the optimization of QoC and QoS in networked control systems

A class of networked control systems is investigated whose communication network is shared with other applications. The design objective for such a system setting is not only the optimization of the control performance but also the efficient utilization of the communication resources. We observe that at a large time scale the data packet delay in the communication network is roughly varying piecewise constant, which is typically true for data networks like the Internet. Based on this observation, a dynamic data packing scheme is proposed within the recently developed packet-based control framework for networked control systems. As expected this proposed approach achieves a fine balance between the control performance and the communication utilization: the similar control performance can be obtained at dramatically reduced cost of the communication resources. Simulations illustrate the effectiveness of the proposed approach.

CUDA's Mapped Memory to Support I/O Functions on GPU

The API interfaces provided by CUDA help programmers to get high performance CUDA applications in GPU, but they cannot support most I/O operations in device codes. The characteristics of CUDA＇s mapped memory are used here to create a dynamic polling service model in the host which can satisfy most I/O functions such as read/write file and ＂printf＂. The technique to implement these I/O functions has some influence on the performance of the original applications. These functions quickly respond to the users＇ I/O requirements with the ＂printf＂ performance better than CUDA＇s. An easy and effective real-time method is given for users to debug their programs using the I/O functions. These functions improve productivity of converting legacy C/C＋＋ codes to CUDA and broaden CUDA＇s functions.