Distributing Profit of Web Services Communities
Based on Shapley Value
Jiajun Wu, Xiaodong Fu
*
, Li Liu, Lijun Liu,Qingsong Huang
Faculty of Information Engineering and Automation
Kunming University of Science and Technology
Kunming, China
xiaodong_fu@hotmail.com
Abstract—Community of Web Service is a society
composed by a number of functionally identical Web Services.
The communities are regarded as a whole for users in an
opening environment and users would pay for services when
they invoke Web Service successfully. Communities should
distribute the whole profit to all of the providers of Web
Services inside after a settlement period. Due to the
cooperation among Web Services in a community we treat
these Web Services as a cooperative game. In this paper we
propose a method to distribute profit based on Shapley value
which considers the contribution of each Web Service to
community and we then implement an algorithm based on
MC-nets to suit the actual situation which we always cannot
get complete input for general algorithm of computing Shapley
value. We also show our method is efficient and practicable.
Keywords—Web Service communities; profit
distritution;cooperative game;Shapley value; MC-nets
I. INTRODUCTION
With the rapid growing number and field expanding of
Web Services, the increasing studies have focused on the
communities of Web Services. A community of Web Service
can be described, released, discovered and invoked as a Web
Service based on the standard and protocol of XML in an
opening environment such as Internet. The organization form
of community reduces greatly the operating cost for
providers of Web Service and simplifies the discovering
process for users therefor.
The Web Services in a community can be regarded as
commodities which are offered by providers of Web
Services, and the providers aim at obtaining benefit by their
commodities (i.e., the payout Web Services). However, the
Web Services have different performance such as QoS [1]
despite they have similar function and then there must be
complex coopetition among them. The reputation
classification of a community will increase and the average
waiting time of users will reduce with increasing number of
Web Service in a community, and normally, users are willing
to pay more if they invoke a Web Service in a community
with good reputation or they spend less time on waiting to
invoke. Therefore the relationships among Web Services in a
community mainly embody cooperation. For this reason, the
whole profit of a community will increase by sup-linear with
the linear increase of the number of Web Services in a
community.
The case above can be regarded as cooperative game and
then we need a fair and practicable way to distribute the
whole profit to all of providers of Web Services in a
community after a settlement period, the basis of distribution
always depends on marginal contribution [2] of each Web
Service to their community and the normal way is
computing their Shapley values.
In this paper, we treat each Web Service as a player in a
cooperative game, the profit of a community may vary with
the coalition of Web Service resided in this community and
we treat the each coalition and its corresponding profit as the
characteristic function, thereby we computing Shapley value
by set of characteristic functions.
However, we have to take note that the general algorithm
of computing Shapley value has exponential time and space
complexity, in other words, we have to get all of
characteristic functions of all coalitions for inputs and so it
does not scale well. Due to the limitation, in our paper we
compute Shapley value by using MC-nets which proposed
by Samuel Ieong et al in [3] to compact representation. Then
we design and implement a relevant algorithm to convert our
characteristic functions to satisfy the rules of MC-nets. We
also show the efficient and practicable of our method in
Section 5.
II. RELATED WORK
Great progress has been made in research on Web
Service. In [5], Zakaria Maamar et al. firstly proposed the
Web Services communities which reside numbers of Web
Services that have similar functions and are agent-based [7]
aiming to manage the rapid increasing Web Services in an
open environment such as the Internet.
Recently, the researches on Web Services community
are mainly about the framework and reputation [8] [9] [10]
[11]. However, there is no research on profit distribution. In
[5], the author referred the cooperation among Web Services
in a community. The competition comes from the desire of
each Web Service because everyone eager to participate
invoking as often as possible. On the other hand,
cooperation also exists because Web Services in a
____________________________________
978-1-4799-8353-7 /15/$31.00 ©2015 IEEE
814
资源评论
