没有合适的资源?快使用搜索试试~ 我知道了~
温馨提示
The study on alternative combination rules in Dempster-Shafer theory (DST) when evidences are in conflict has emerged again recently as an interesting topic, especially in data/information fusion applications. The earlier researches have mainly focused on investigating the alternative which would be appropriate for the conflicting situation, under the assumption that a conflict is identified. However, the current research shows that not only the combination rule but also the classical conflict c
资源推荐
资源详情
资源评论
Journal of Systems Engineering and Electronics
Vol. 23, No. 1, February 2012, pp.1–9
New conflict representation model in generalized power space
You He
1
, Lifang Hu
1,2,∗
, Xin Guan
1,3
, Deqiang Han
4
, and Yong Deng
5
1. Research Institute of Information Fusion, Naval Aeronautical and Astronautical University, Yantai 264001, P. R. China;
2. Navy Armament Academy, Beijing 102249, P. R. China;
3. College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, P. R. China;
4. Institute of Integrated Automation, Xi’an Jiaotong University, Xi’an 710049, P. R. China;
5. School of Electronics and Information Technology, Shanghai Jiaotong University, Shanghai 200240, P. R. China
Abstract:
The study on alternative combination rules in Dempster-
Shafer theory (DST) when evidences are in conflict has emerged
again recently as an interesting topic, especially in data/information
fusion applications. The earlier researches have mainly focused
on investigating the alternative which would be appropriate for
the conflicting situation, under the assumption that a conflict is
identified. However, the current research shows that not only the
combination rule but also the classical conflict coefficient in DST
are not correct to determine the conflict degree between two pieces
of evidences. Most existing methods of measuring conflict do not
consider the open world situation, whose frame of discernment
is incomplete. To solve this problem, a new conflict representa-
tion model to determine the conflict degree between evidences
is proposed in the generalized power space, which contains two
parameters: the conflict distance and the conflict coefficient of
inconsistent evidences. This paper argues that only when the con-
flict measure value in the new representation model is high, it is
safe to say the evidences are in conflict. Experiments illustrate the
efficiency of the proposed conflict representation model.
Keyw ords: Dezert-Smarandache theory (DSmT), conflict evi-
dence, Dempster rule of combination, information fusion.
DOI: 10.1109/JSEE.2012.00001
1. Introduction
Dempster-Shafer theory (DST) is widely used in many
fields such as information fusion and decision-making
[1]. In the framework of DST, information fusion re-
lies on the use of combination rules allowing the belief
Manuscript received April 8, 2010.
*Corresponding author.
This work was supported by the National Natural Science Founda-
tion of China (60572161; 60874105), the Excellent Ph.D. Paper Au-
thor Foundation of China (200443), the Postdoctoral Science Foundation
of China (20070421094), the Program for New Century Excellent Ta-
lents in University (NCET-08-0345), the Shanghai Rising-Star Program
(09QA1402900), and the Ministry of Education Key Lab of Intelligent
Computing & Signal Processing (2009ICIP03).
functions to combine different propositions. A crucial role
in DST is played by the Dempster’s rule of combination
(DRC) that has several interesting mathematical proper ties
such as commutativity and associativity. However, illog-
ical results may be obtained by DRC when the collected
evidences highly conflict with each other [2].
Since then, many authors used Zadeh’s example to criti-
cize DST either as a whole, or as a motivation for con-
structing alternative combination rules, which mainly di-
ffer from the way possible conflicts are managed [3−21].
Recently, due to the increasing applications of DST in in-
telligent fusion processes, DRC and its alternatives have
been under the microscope again (e.g., [3,4,7]).
Overall, the existing studies can be divided into two ma-
jor categories.
The first is how to use DRC. There exist three kinds
of circumstances. One is how to use the close world of
DRC including the improvement of combination rules and
the modification of the primal data sources [3−14]. An-
other is to support the open world. References [15,16]
are representative in this method. The third is to sup-
port the integration of close and open worlds. So the
hyper-power set and the general power set are put forward
[17−19].
The second is how to reasonably measure the conflict
between evidences [20−22]. Reference [20] proposed an
alternative method to measure the conflict among beliefs
using a pair of values, and the mass of the combined belief
allocated to the emptyset before normalization and the d is-
tance between betting commitments. Reference [ 21] paid
more attention to the essence of conflict in their researches.
Their studies have mainly focused on investigating reasons
for conflicting situations and choosing alternative rules
which would be appropriate for the corresponding con-
flicting situation. This is also the primary idea of this
paper.
2 Journal of Systems Engineering and Electronics Vol. 23, No. 1, February 2012
2. DST and Liu’s method
2.1 DST
Let U be a frame of discernmen t. A basic probability as-
signment (BPA) m is mapping from elements of the power
set 2
U
onto [0, 1] such that
m(φ)=0,
X∈2
U
m(X)=1. (1)
In the case of imperfect data (uncertain, imprecise and
incomplete), fusion is an interesting solution to obtaining
more relevant information. DST offers appropriate ag-
gregation tools. From the BPA denoted m
i
obtained for
each information source S
i
, it is possible to use a combi-
nation rule to provide combined masses synthesizing the
knowledge of the different sources. n bodies of evidences
m
1
,...,m
n
can be combined with Dempster’s orthogonal
rule as follows:
m(C)=
⎧
⎪
⎪
⎨
⎪
⎪
⎩
A
i
∩B
j
∩···∩Z
k
=C
m
1
(A
i
)m
2
(B
j
) ···m
n
(Z
k
)
1 − K
, ∀C ⊂ U ; C = φ
0,C= φ
(2)
with
K =
A
i
∩B
j
∩···∩Z
k
=φ
m
1
(A
i
)m
2
(B
j
) ···m
n
(Z
k
) (3)
where K is a normalization con stan t, called conflict, be-
cause it measures the degree of conflict in the frame of
DST.
2.2 Liu’s method
Let m
1
and m
2
be BPAs on frame U . The distance be-
tween betting commitments of the two BPAs is defined as
difBetP
m
2
m
1
=max
A⊆U
(|BetP
m
1
(A) − BetP
m
2
(A)|)
(4)
where BetP
m
1
and BetP
m
2
are the results of two pignistic
transformations from them respectively, and BetP(A)=
θ∈A
BetP(θ).Value(|BetP
m
1
(A) − BetP
m
2
(A)|) is the
difference between betting commitments to A from the two
sources. The distance of betting commitm ents is there-
fore the maximum extent of the differences between bet-
ting commitments to all the subsets. difBetP
m
2
m
1
is sim-
plified as difBetP when there is no confusion about two
BPAs being compared.
Obviously, difBetP
m
2
m
1
=0whenever m
1
= m
2
, i.e.,
the distance between betting commitments is always 0 be-
tween any two identical BPAs (total absence of conflict).
Given two BPAs and their corresponding pignistic
transformations, it is possible that these two BPAs have
the same betting commitment to a subset A (that is,
BetP
m
1
(A)=BetP
m
2
(A)), but have rather different bet-
ting commitments to another subset B. For this reason, we
cannot use either min or mean to replace operator max in
the above definition, since we want to find out the maxi-
mum, not the minimum or the average, level of differences
between their betting commitments.
Let m
1
and m
2
be two BPAs. Let cf(m
1
,m
2
)=
K, difBetP be a two-dimensional measure. m
1
and m
2
are d efined in conflict if both difBetP > ε and K>ε
hold, where ε ∈ [0, 1] is the threshold of conflict tolerance.
3. Some definitions and theorems
According to the physical requirement, we may choose a
special model, so if we choose the DST model, Dezert-
Smarandache theory (DSmT) model and unification of f u-
sion theories (UFT) model, then we get the power set 2
U
,
hyper power-set D
U
and hyper-power set S
U
including 2
U
and D
U
, respectively. Here without loss of generality,
we denote G
U
as the generalized power set on which the
BPAs (GBPAs) (or masses) are defined, i.e., G
U
=2
U
when DST is adopted, G
U
= D
U
when DSmT [4,5,20]
is adopted, G
U
= S
U
when UFT model is adopted. For
UFT [16], its hyper-power set S
U
= {U, ∪, ∩,},thatis,
U closed under these three operations: union, intersec-
tion, and complementation of set, forms a Boolean alge-
bra, and then a general basic belief assignment (GBBA)
as a mapping m(·):S
U
→ [0, 1], associating with a
given source, saying S, of evidence with m(φ) 0 and
A∈S
U
m(A)=1,isdefined. m
S
(A) is the GBBA of
A committed by the sources. Of course, in the DST and
DSmT model, m(φ)=0. So the hyper-power set S
U
is
more general. But for engineering applications, system de-
signers often adopt the DST model and DSmT model.
Definition 1 (measure of conflict) Consider any n
GBPAs, it is to say m
1
(·),...,m
n
(·) defined over the
same space G
U
, the mapping CM(·):G
U
×···×G
U
→
[0, 1] is called a conflict measure function (CMF), if the
following three c onditions are satisfied:
(i) ∀m
1
(·),...,m
n
(·), CM(m
1
,...,m
n
)=CM
(m
n
,...,m
1
),
剩余8页未读,继续阅读
资源评论
weixin_38695293
- 粉丝: 6
- 资源: 956
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
最新资源
资源上传下载、课程学习等过程中有任何疑问或建议,欢迎提出宝贵意见哦~我们会及时处理!
点击此处反馈
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功