"Service Selection Algorithms for Web Services with end-to-end QoS constraints (is

Yu Tao
Home: http://link.ece.uci.edu/tyu/index.html
My resume: I studied at Chengdu University of electronic science and technology (1995). My master's degree is beiyou (1998). My PhD is at the University of California, Irvine (2002 ), the title of this doctoral thesis is "QoS (Quality of Service) in Web Services: Architecture, model and algorithms"

from 05 to 05 ~ In, I published a series of papers on Web Service Selection with QoS constraints:
T. yu and K. j. lin " Service Selection Algorithms for Web Services with end-to-end QoS Constraints ", Journal of Information Systems and e-Business Management, Volume 3, number 2, July 2005
T. yu and K. j. lin, " Service Selection Algorithms for composing complex services with multiple QoS Constraints ", icsoc2005
T. yu and K. j. lin, " adaptive algorithms for finding replacement services in autonomic distributed business processes . "isads2005
T. yu and K. j. lin " A broker-based framework for QoS-Aware Web service composition ", eee05
Tao Yu, Yue Zhang, Kwei-Jay Lin: efficient algorithms for web services selection with end-to-end QoS Constraint S. tweb 1 (1): (2007)

I reread "Service Selection Algorithms for Web Services with end-to-end QoS constraints (isebm2005)" today )".
This article studies how to select a web service so that the overall QoS of the composite service satisfies the constraints and maximizes the utility value.
This thesis simplifies the research:
(1) only consider sequantial composition model (this is a major simplification)
(2) only consider having one QoS Constraint (Delay)

Two methods are used to solve the problem: Combinatorial approach and graph approach.
In combinatorial approach,
The problem is modeled as mckp (Multi-choice backpack problem) and exhausive search, dynamic programming, and pisinger are used.AlgorithmTo solve.
The disadvantage of this method is that it is impossible to model transmision delay and cost. because different services in the same service class can be provided by different providers, and different providers can be in different networks, there are differences in the transmission delay/cost between services, however, in combinatorial approach, it can only be assumed that the transmission delay/cost between two services is the same.

In graph approach,
Using Dag for modeling (if there are other composition models, such as parallel, it seems difficult to use the existing modeling method in this article), after conversion, map cost/benefit and other parameters to the edge.
Create a constrained Shortest Path in graph theory.
The constrained Bellman-Ford (CBF) and constrained Shortest Path (CSP) algorithms are used to solve the problem.
The CBMs algorithm is exponential.

other notes
(1) dominate relationship (s5.2.3, mentioned in algorithm 1)
two paths A and B, if (. utility> = B. utility) & (. delay <= B. delay), it is called path a dominate path B, that is, path a is superior to path B in every aspect.
(2) topological order
definition: A numbering of the vertices of a directed acyclic graph such that every edge from a vertex numbered I to a vertex numbered J satisfies I