scholarly journals Trusted QoS Assurance Approach for Composite Service

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Meng Cai ◽  
Ying Cui ◽  
Yang Yu ◽  
Ying Xue ◽  
Han Luo
Keyword(s):  
Search Algorithm ◽  
Loose Coupling ◽  
Computing Systems ◽  
Composite Service ◽  
Service Computing ◽  
Composite Services ◽  
Levels Of Service ◽  
Constituent Atom ◽  
Qos Requirement

The characteristics of service computing environment, such as service loose coupling, resource heterogeneity, and protocol independence, propose higher demand for the trustworthiness of service computing systems. Trust provisioning for composite services has become a hot research spot worldwide. In this paper, quality of service (QoS) planning techniques are introduced into service composition-oriented QoS provisioning architecture. By QoS planning, the overall QoS requirement of the composite service is decomposed into separate QoS requirement for every constituent atom service, the QoS level of which can subsequently be satisfied through well-designed service entity selection policies. For any single service entity, its QoS level is variable when the deployment environment or the load of service node changes. To mitigate the uncertainty, we put forward QoS preprocessing algorithms to estimate the future QoS levels of service entities with their history execution data. Then, based on the modeling of composite service and QoS planning, we design three algorithms, which include the time preference algorithm, cost/availability (C/A) preference algorithm, and Euclidean distance preference algorithm, to select suitable atomic services meeting the user’s requirements. Finally, by combining genetic algorithm and local-search algorithm, we propose memetic algorithm to meet the QoS requirements of composite service. The effectiveness of the proposed methods by which the QoS requirements can be satisfied up to 90% is verified through experiments.

Quantifying the Resilience of Cloud-Based Manufacturing Composite Services

2018 ◽  
Vol 8 (4) ◽  
pp. 88-117 ◽  
Author(s):  
Mohammad Reza Namjoo ◽  
Abbas Keramati ◽  
S. Ali Torabi ◽  
Fariborz Jolai
Keyword(s):  
Recovery Time ◽  
Supply And Demand ◽  
Step Method ◽  
Composite Service ◽  
Quality Of Recovery ◽  
Essential Components ◽  
Composite Services ◽  
System Resilience ◽  
Generic System

Composite services are regarded as essential components of a cloud-based manufacturing (CM) system. Different classes of disruptive events which are rooted in the uncertainties of the supply and demand sides of CM threaten the resilience and continuity of the composite services over time. The present article proposes a resilience measure based on a generic system resilience metric along with a two-step method based on MCDM and SIS-Monte-Carlo to quantify the resilience of CM composite services by considering recovery time objective (RTO). To present the applicability of the proposed method, a numerical example was designed and simulated. The results showed that the resilience of composite service is sensitive to geographical distance, RTO, and quality of recovery.

Composite Service Reselection Method in Correlation Context

2015 ◽  
Vol 12 (2) ◽  
pp. 73-97 ◽  
Author(s):  
Yuesong Zhang ◽  
Bin Zhang ◽  
Changsheng Zhang
Keyword(s):  
Service Providers ◽  
Service Selection ◽  
Quality Of Services ◽  
Mining Method ◽  
Composite Service ◽  
Research Issues ◽  
Service Computing ◽  
The Core ◽  
Execution Environment

Reselection of composite service is one of the core research issues in service computing field. In practical scenarios, because of business relations between service providers or the restrictions of service physical deployment environment, there may be correlation among services. Its existence affects the quality of services used together, makes corresponding abstract services potentially correlating with each other. This leads the QoS used to determine the bindings between abstract and concrete services to be inaccurate, and the selected services would not be the optimal one in actual execution environment. In this paper, the QoS-Correlation services are extracted from the execution log through Apriori data mining method. Then, the authors capture the correlated abstract services to present such correlations in a higher level of abstraction regardless of actual services. In the final, the correlated abstract services will be regarded as a task unit, and the corresponding correlation services of each task unit as its candidate services set. They also propose a correlation-aware service selection method in the paper. The method includes runtime reselection whenever the actual QoS largely deviates from the estimates.

scholarly journals On Establishing QoS for Composite Services

2016 ◽  
Author(s):  
Nguyen Van Son ◽  
Vo Dinh Hieu
Keyword(s):  
Quality Of Service ◽  
Service Composition ◽  
Simple Approach ◽  
Complex Task ◽  
Composite Service ◽  
Composite Services ◽  
Better Than

Service  composition  is  a  process  of combining existing atomic services to perform a complex task. To choose atomic services for a composite service, usually  both  functionality  and  quality  of  service  (QoS) are  considered.  The  QoS  of  the  composite  service obviously  depends  on  QoS  of  atomic  services.  In  this research,  we  propose  a  simple  approach  for  the composite  service  and  atomic  services  to  establishing suitable  QoS  values.  Experiment  shows  that  our approach  is  feasible  and  significantly  better  than  the exhaustive approach in performance aspect.

scholarly journals Young clients’ attitudes to service quality at retail banks in a developing country

2017 ◽  
Vol 12 (1) ◽  
pp. 44-53
Author(s):  
Nkululeko Praise God Zungu ◽  
Roger B. Mason
Keyword(s):  
Service Quality ◽  
Developing Country ◽  
Jel Classification ◽  
Retail Banking ◽  
Statistical Techniques ◽  
University Campuses ◽  
Quota Sampling ◽  
Levels Of Service ◽  
Retail Banks

The aim of this paper is to investigate service quality as perceived by younger customers of retail banks in a developing country. The objectives include identifying customers’ levels of satisfaction and loyalty to their banks and to identify the levels of service quality associated with such satisfaction and loyalty. The instrument used to collect data via a survey of retail bank customers was an adaptation of the SERVQUAL questionnaire. A total of 448 students were surveyed, using a mix of systematic and quota sampling, with data being collected on university campuses. Data were analyzed using descriptive statistical techniques. The main conclusions were that most young customers are reasonably satisfied with, and loyal to, their banks. There was little difference, on all the service quality constructs, between the different banks, and between expectations and perceptions of service quality. However, there was no evidence of any bank providing a service that delighted their customers or exceeded their expectations and so all banks are at risk from a competitor who adopts strategies to meet these goals. The study has contributed to knowledge by focusing on attitudes to service quality of young bank customers in a developing country, an aspect that has been under-researched. Keywords: service quality, retail banking, expectations, perceptions, customer satisfaction, loyalty, SERVQUAL, South Africa. JEL Classification: G21, L84, M31

scholarly journals Service Level Agreement (SLA) in Utility Computing Systems

2012 ◽  
pp. 1-25 ◽  
Author(s):  
Linlin Wu ◽  
Rajkumar Buyya
Keyword(s):  
Service Level Agreement ◽  
Service Level ◽  
Future Research ◽  
Fundamental Issue ◽  
Utility Computing ◽  
Computing Systems ◽  
Comprehensive Survey ◽  
Autonomy Management ◽  
State Of Art

In recent years, extensive research has been conducted in the area of Service Level Agreement (SLA) for utility computing systems. An SLA is a formal contract used to guarantee that consumers’ service quality expectation can be achieved. In utility computing systems, the level of customer satisfaction is crucial, making SLAs significantly important in these environments. Fundamental issue is the management of SLAs, including SLA autonomy management or trade off among multiple Quality of Service (QoS) parameters. Many SLA languages and frameworks have been developed as solutions; however, there is no overall classification for these extensive works. Therefore, the aim of this chapter is to present a comprehensive survey of how SLAs are created, managed and used in utility computing environment. We discuss existing use cases from Grid and Cloud computing systems to identify the level of SLA realization in state-of-art systems and emerging challenges for future research.

A Fuzzy Set Approach in the Quantification of Technical Support Service Quality

1998 ◽  
Vol 42 (6) ◽  
pp. 564-568 ◽  
Author(s):  
Sridevi S. Rao ◽  
Ray Eberts ◽  
M.U. Thomas ◽  
Robert Plante
Keyword(s):  
Service Quality ◽  
Fuzzy Set ◽  
Individual Variation ◽  
Behavioral Intentions ◽  
Support Service ◽  
Technical Support ◽  
Quality Dimension ◽  
Study Results ◽  
Levels Of Service

Consumers' perceptions of service quality are highly qualitative as well as subjective. Individual variation exists in the meaning of “low,” “medium,” or “high” levels of service quality. A framework for quantifying the service quality dimension levels for technical support service is presented in the current study. Results are combined with the utility values of the dimension levels obtained through conjoint analysis. Customers' behavioral intentions subsequent to the quality of the technical support they experience are also found empirically. The methodology presented in this research can be used in improving the comprehensibility and quantification of service quality.

Restoration of Motion Blurred Image Based on PSO Combine Wiener Filter in Ship Imaging System

2014 ◽  
Vol 1006-1007 ◽  
pp. 739-742
Author(s):  
Hui Xuan Fu ◽  
Yu Chao Wang ◽  
Xun Su
Keyword(s):  
Imaging System ◽  
Search Algorithm ◽  
Wiener Filter ◽  
Optimal Solution ◽  
Parameter Selection ◽  
Improve Image Quality ◽  
Blurred Image ◽  
Blurred Images ◽  
Ringing Effect

Ship internal equipment vibration will cause the imaging system platform vibration, resulting in blurred images. Wiener Filter is often used to restore the motion blurred image. The principle of the method expects to minimize the mean square error between the restore image and original image. However, this method has some constrains, if parameter selection improper, it generates ringing effect easily. Usually, most users select parameter by rule of thumb, so they frequently fail to generate the optimal solution. In order to get high quality restore image, eliminate the ringing effect, a new approach based on particle swarm optimization (PSO) Wiener Filter was proposed, which automatically adjusts the parameter for Wiener Filter, this method seek the optimal solution by transferring information between individuals and information sharing, which is a highly efficient parallel search algorithm, insuring the accuracy of parameter selection, effectively reducing the ringing effect after image restoration, improve image quality of restoration.

Achieving Dependable Composite Services through Two-Level Redundancy

2012 ◽  
pp. 295-316
Author(s):  
Hailong Sun ◽  
Jin Zeng ◽  
Huipeng Guo ◽  
Xudong Liu ◽  
Jinpeng Huai
Keyword(s):  
Business Process ◽  
Service Composition ◽  
Service Performance ◽  
Structural Redundancy ◽  
Composite Service ◽  
Service Oriented ◽  
Composite Services ◽  
Insightful Analysis ◽  
Process Level

Service composition is a widely accepted method to build service-oriented applications. However, due to the uncertainty of infrastructure environments, service performance and user requests, service composition faces a great challenge to guarantee the dependability of the corresponding composite services. In this chapter, we provide an insightful analysis of the dependability issue of composite services. And we present a solution based on two-level redundancy: component service redundancy and structural redundancy. With component service redundancy, we study how to determine the number of backup services and how to guarantee consistent dependability of a composite service. In addition, structural redundancy aims at further improving dependability at business process level through setting up backup execution paths.

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