the correlation between each index to calculate the
weight according to a certain mathematical model.
The advantage of this method is that it fully
exploited the original data’s information. The
evaluation results have a strong theoretical basis and
are more close the reality. But this method ignored
the decision-makers’ knowledge and experience,
which will have certain deviations to the
decision-makers’ feeling. Therefore, we usually use
the comprehensive evaluation method based on the
subjective weighting method and the objective
weighting method to calculate each factor’s weight.
Wu Chun-you and Liu Yan
use the
comprehensive evaluation method based on the G1
method and the entropy method to determine the
weight of the factors that impact the interests of the
city-renewable resources (Wu Chun-you, Liu Yan,
2010). Ma Xiao-ying
uses the entropy method to
assess the readers’ satisfaction in the university
library and gets the weights of different factors that
affect the readers’ satisfaction (Ma Xiao-ying,
Zhang Guo-hai, Han Shu-fen, 2007). Song Li-min
also uses the comprehensive evaluation method
based on the AHP method and the entropy method to
get the weight of different indicators between
different readers (Song Li-min, 2009). Meng Ming
uses the same comprehensive evaluation method to
assess the power customer satisfaction and get the
weights (Meng Ming, Niu Xiao-dong, Gu Zhi-hong,
2005). Peng Jin-shuan uses the comprehensive
evaluation method based on the entropy method and
the subjective weighting method to evaluate the
passenger’s satisfaction to the urban public transport
and get each factor’s weight (Peng Jin-shuan, Hao
Yi-ming, Peng Li-fang, 2007).
Some scholars use the rough set theory to
evaluate the weight of different factors. Xiong Ping
proposed a new subjective weighting method based
on the information concept in rough set (Xiong Ping,
Cheng Hua-bin, Wu Xiao-ping, 2003). They
established a comprehensive optimization model to
determine the weight based on the optimization
theory. Hao Cheng uses the rough set theory to
research the weight of the effectiveness factors in
the urban rail transit project. Furthermore, they
obtained the combined weights of multiple factors
(Hao Cheng, Li Jing, Li Xue-Mei, Li Xue-wei,
2008).
Up to now, no one has used the rough set theory
to evaluate the railway passenger’s satisfaction.
Furthermore, no one has used a method based on the
rough method and the entropy method the get the
in-depth assessment for the railway passenger’s
satisfaction. First, this paper will use the rough set
theory to ascertain the factors’ subjective weight that
affects the passenger’s satisfaction. And then use the
entropy method to calculate the factors’ objective
weight. Finally, we use the comprehensive weight
formula
(Liu Jie, Li Chao-feng, Li Xiao-peng, Wen
Bang-chun, 2008) to calculate each factor’s weight
so that we can know the degree of different factors
that influence their travel choice.
3 THE SUBJECTIVE METHOD
BASED ON ROUGH SET
The rough theory, which was proposed by the Polish
mathematician Z. Pawlak in 1982, was a
mathematical method that research the
expression,learning and induction of the imprecise,
uncertain and incomplete data (China Research
Center of Industrial Safety in Beijing Jiaotong
University, 2009). The key points of this method to
blend classification and knowledge together and
then classify the data in the form of equivalence
because the knowledge comes from the human and
other species’ classification ability. The main idea of
this method is to deduce the decision-making and
classification rule of the problem through the
knowledge reduction on condition that the
classification ability doesn’t change. This method
was widely used in data analysis, data mining and
knowledge classification and other fields. This
theory which attracted wide attention from scholars
around the world in the 1990s in the 20th century
was successfully applied in the field of data analysis
and decision making, pattern recognition, machine
learning and knowledge discovery, etc.
3.1 Knowledge Definition
According to the rough set theory, a knowledge
representation system “S” can be expressed by
describing the attributes and the attribute values of
the research object (Chun-bao Chen, Li-ya Wang,
2006). So we define a equation:
(, ,,)SUCDVf
.
In this formula,
12
,,Uxx
means a collection
of objects.
12
,,Ccc
means the subjects of
the condition attributes set.
12
,,Ccc
means
the subjects of the decision attributes set. And the
conditions are
CDA
and
.CD
.
V
is
the collection of the attribute set.
:
UA V
is
an information function which gives each attribute
ICEIS 2011 - 13th International Conference on Enterprise Information Systems
630