2010 Vol. 19, No. 1

Display Method:
E±cient Architecture for 2-Dimensional DiscreteWavelet Transform with Novel Lifting Algorithm
WANG Chao, CAO Peng
2010, 19(1): 1-6.
Abstract(1104) PDF(1641)
Abstract:
In commonly-used line-based implementa-
tion for Two-dimensional Discrete wavelet transform (2D
DWT), data bu®er is required between the row DWT
processor and the column DWT processor to reorder the
data °ow into consistent sequence, which increases the on-
chip memory size, output latency and control complex-
ity. Based on the proposed Decomposed lifting algorithm
(DLA), image data is processed in raster scan manner both
in row processor and column processor. Theoretical anal-
ysis indicates that the precision of DLA outperforms other
lifting-based algorithms in terms of round-o® noise and in-
ternal word-length. An e±cient line-based architecture is
designed to perform 2D DWT based on DLA with high per-
formance and low memory by eliminating the implementa-
tion of data bu®er. For an N £ N image, only 4N internal
memory is required for 9/7 ¯lter with output latency of
2N clock cycles. Compared with related 2D DWT archi-
tectures, the size of on-chip memory and output latency
are reduced signi¯cantly under the same arithmetic cost,
memory bandwidth and timing constraint. This design
was implemented in SMIC 0.18¹m CMOS logic fabrication
with 32K bits dual-port RAM and 20K equivalent 2-input
NAND gates in a 1.2mm£1.1mm die, which can perform
5-level Mallat decomposition at 36.17frames/s with image
resolution up to 1920 £ 1080 pixels in YUV422 full color format under 100MHz.
Some Constant-Round Zero-KnowledgeProtocols
LIU Hanwu, LIN Dongdai
2010, 19(1): 7-12.
Abstract(966) PDF(1224)
Abstract:
The concept of zero-knowledge has been
extensively used in the design of cryptographic protocols
since being introduced. The round complexity of zero-
knowledge protocols is a very important e±ciency con-
sideration, and in general it is desirable to have zero-
knowledge protocols with constant numbers of rounds. In
this paper, we suggest a novel method to use the program
of the veri¯er and use the method to construct some con-
stant round honest-veri¯er zero-knowledge protocols. The
notion of honest-veri¯er zero-knowledge protocols is highly
non-trivial and fascinating itself. It also has many other uses.
A Highly-effcient Approach of Parallel Access toRouting Table on TBGP
GAO Lei, LAI Mingche, GONG Zhenghu
2010, 19(1): 13-17.
Abstract(1004) PDF(1316)
Abstract:
The urgent requirement for the high-
e±ciency of routing protocol on Internet will be satis¯ed by
exploiting the Threaded border gateway protocol (TBGP)
on multicores. Since TBGP performance is restricted by
a mass of contentions when accessing routing table, an
e±cient parallel access approach is proposed to achieve
the ultra-high route processing. This paper presents a
novel routing table structure including two-level tries, and
a heuristic-based divide-and-recombine algorithm is de-
vised to balance the accesses and release the contentions
by multi-threading. Experimental results on Intel Xeon
server show that the parallel access contentions under dif-
ferent thread con¯gurations decrease by 98.7% averagely.
Meanwhile, the maximal update time per thread is obvi-
ously reduced and the throughput of update message is
improved by 153%, delivering signi¯cant performance improvement of BGP.
Multi-Interest Self-Organizing LearningCommunity Model and Construction Algorithms
ZHANG Tongzhen, SHEN Ruimin
2010, 19(1): 18-22.
Abstract(928) PDF(1241)
Abstract:
Building learning communities is an e®ec-
tive solution to conquer feelings of loneliness and to share
experiences and resources with one another quickly and
e±ciently for learners in an e-learning environment. Ex-
isting community models focus only on each learner's sin-
gle or primary interest and ignore other interests a learner
may hold simultaneously. This paper proposes a multi-
interest self-organizing learning community model based
on multi-agent technology. Learners with similar interests
are automatically grouped into the same community; and,
each learner associates with several communities because
of his or her multiple interests. This paper also proposes
a novel community construction algorithm by calculating
knowledge semantic similarity and clustering learner in-
terests; and introduces a dynamic community adjustment
algorithm by monitoring the learning activities performed
by learners. Experiment results in a real e-learning envi-
ronment have shown the e®ectiveness and e±ciency of the
model and corresponding algorithms.
Similarity Degree-based Mobile Pattern AwareRouting in DTNs
YIN Lei, LU Huimei, CAO Yuanda
2010, 19(1): 23-28.
Abstract(922) PDF(1111)
Abstract:
Taking mobile pattern into consideration
can bene¯t routing performance in Delay tolerant networks
(DTN). Based on common sense, the more similar the mo-
bile patterns of nodes are, the more stable their relative
positions are resulting in a connection with a longer du-
ration. In this paper, a scheme named Similarity degree
based Mobile pattern aware routing (SD-MPAR) is pro-
posed. A comprehensive metric called similarity degree is
applied to scale the degree of similarity between the mobile
pattern of nodes which includes deviation of the sender's
speed direction from that of the destination, and distance
from the sender to the destination. Similarity degree is
also a key factor to decide the next hop. A message is
forwarded to the next hop node with the largest similarity
degree. Through theoretical analysis and simulation, SD-
MPAR shows the advantages deliver ratio, overhead, de-
liver latency and average number of hops over other rout-
ing schemes including epidemic and distance-based rout-
ing.
A Simulation System and Algorithm Evaluationfor Clustered Streaming Media Server
CHAI Yunpeng, DU Zhihui, SUN Lifeng
2010, 19(1): 29-34.
Abstract(938) PDF(937)
Abstract:
This paper designs and implements
CSMSSim, which is a hierarchical simulation system for
Clustered streaming media server (CSMS). CSMSSim is
e±cient and accurate, because it is based on an accurate
and simpli¯ed simulation model of CSMS, and the nec-
essary hardware resources' parameters in CSMSSim are
obtained through the stress testing based on a practical
CSMS testbed with 6 nodes. In addition, CSMSSim is
highly con¯gurable, because it has a hierarchical architec-
ture with independent algorithm layer, logical layer and
hardware layer. Therefore CSMSSim can adapt to various
streaming media applications, and the rapid increasing of
the streaming media service systems' scale in nowadays
and the future. Finally, the simulation experiments on the
CSMS algorithm evaluation based on CSMSSim show the
powerful function of CSMSSim, and give guidance about
improving the performance of CSMS by choosing appro-
priate memory cache replacement algorithms and disk data
allocation algorithms.
Micro System Design Based on Digital ADC andFPGA for Super-Slow Spectrum Analysis
LI Wenshi
2010, 19(1): 35-38.
Abstract(976) PDF(1777)
Abstract:
The super-slow spectrum (3S, 0mHz »
40mHz) be the important feature of neurotransmitters in
slow synaptic transmissions for brain cognition function.
3S analysis focuses on the near infrared (940nm) otopoints
(mapping prefrontal cortex and temporal lobe) data in high
validity for such as lie detection. The goal is to design 3S
analysis micro system based on digital ADC and FPGA.
My ideas are in voltage-controlled oscillator (not gate chain
or Schmitt trigger) for digital ADC and in state machine
and embedded RAM with Cyclone EP1C6 FPGA. The db4
order-10 low frequency wavelet algorithm was hardened
into this FPGA. The validity results touched 87% for lie
test and 80% for smile test. This work may lay a prelimi-
nary foundation for neurotransmitter measurement SoC.
Chinese POS Tagging Using Restricted MaximumEntropy Model
ZHANG Hong, REN Fuji
2010, 19(1): 39-42.
Abstract(963) PDF(1125)
Abstract:
This paper presents Chinese Part-of-speech
(POS) tagging using maximum entropy technique, in which
we introduce a novel gain-driven method for feature selec-
tion, then we describe the restricted training method for
model learning. We test our approach on the simpli¯ed
Chinese corpus of Peking University China and achieve an
accuracy of 97.80% and 98.60% over ¯ne and coarse grained
tag set - a signi¯cant improvement over the existing Chi-
nese POS tagger.
Crosstalk Noise Voltage of Coupling RCInterconnects with Temperature Distribution
WANG Zeng, DONG Gang, YANG Yintang, LI Jianwei
2010, 19(1): 43-47.
Abstract(907) PDF(1269)
Abstract:
Based on MT (Masao takahashi) crosstalk
noise model and the analysis of interconnect tempera-
ture e®ect, A temperature-dependent model of intercon-
nect crosstalk noise voltage in time domain for genetic RC
trees is proposed in this paper. The proposed model ana-
lyzes multilevel crosstalk noise voltage in 45nm technology
node and takes the temperature distribution into account
to gain the accurate estimation of interconnect crosstalk
noise voltage. Compared with the previous models, the
proposed method has a precise advantage in three noise
metrics which are peak noise amplitude, noise pulse width
and peak noise occurring time. The proposed method
transforms generic RC interconnects with branches into
the 2-Q model with the maximum errors being 4.4%, 3.1%
and 2.9%, respectively.
Research of E±cient Utilization RoutingAlgorithm for Current FPGA
XIE Ding, LAI Jinmei, TONG Jiarong
2010, 19(1): 48-52.
Abstract(1034) PDF(2091)
Abstract:
Current FPGAs contain routing resources
of di®erent lengths and connectivity, and the connection re-
lation of which are described by hierarchical General rout-
ing matrix (GRM). In this paper, we present a practical
routing algorithm which can represent the complex driv-
ing relationships contained in GRMs and utilize routing
resources more e±cient for GRM based FPGAs. First, we
build Routing resource graph (RRG) by a bottom-up way,
then employ A* directed search algorithm while dynam-
ically updating the base cost of routing resource nodes,
so that the utilization rate of routing resources can be en-
hanced, and this routing algorithm has high-adaptability to
latest FPGA architectures. The experiment result shows
that the utilization rate of hex lines and long lines has been
raised by 6% and 8% respectively.
A Low Power Column-level High SpeedAuto-zeroed Comparator for CMOS Active PixelSensor Based Vertex Detector
LI Yan, Yavuz Degerli, JI Zhen
2010, 19(1): 53-56.
Abstract(1041) PDF(1392)
Abstract:
CMOS active pixel sensors have become
strong candidates for pixel detectors used in high energy
physical experiments. Using standard CMOS fabrication
process, full data processing circuits can be integrated on
the same substrate with sensors and on-chip data process-
ing is achievable. For this purpose, a column level high
speed low power auto-zeroed comparator is developed.
Tested at 100MHz, a resolution better than 0.5mV was
obtained and its output residual o®set is only 0.15mVrms.
The dimension of the comparator is 25¹m£300¹m and its
power dissipation is about 220¹W.
VLSI Design of FC-1 and FC-2 in Fiber Channel
JIN Jie, YU Dunshan
2010, 19(1): 57-60.
Abstract(972) PDF(1274)
Abstract:
Fiber channel (FC) has become a major
technology in Storage area network (SAN), especially in
enterprise datacenters. In this paper, we propose a con¯g-
urable and all-around architecture to implement the FC-1
and FC-2 layers in VLSI. The speed negotiation algorithm
is also implemented in hardware to automatically switch
speed among 4 di®erent speeds. In order to achieve the
on-the-°y processing speed, we utilize the hardware to ac-
celerate the processing of FC-1 and part of FC-2. The
prototype chip is fabricated in a 0.18um CMOS technol-
ogy and the core occupies an area of 7:1£8mm2. The chip
has been validated to be fully functional and can achieve
173MBps processing performance.
Availability Evaluation Method andImplementation Framework of MultilevelSecuerity Systems with CredibilityCharacteristics
TAN Zhiyong, LIU Duo, DAI Yiqi
2010, 19(1): 61-65.
Abstract(952) PDF(952)
Abstract:
| To evaluate and choose proper credibil-
ity evaluation functions and credibility threshold parame-
ters in the Multilevel security (MLS) system based on the
CBLP model which was proposed in the authors' previous
paper, we devised a sampling statistics method to evalu-
ate the availability of the MLS system, by obtaining the
change curve of the subjects' credibility and the rejection
ratio of access operations. The validity of this method was
evaluated according to the strong law of large numbers
and the central limit theorem. The analysis of speci¯c
scenarios showed that the result of the sampling statistics
method is highly consistent with that of the formal analy-
sis methods. Then an implementation framework based on
the availability evaluation method is proposed. Since it is
hard to evaluate the availability of the system completely
by formalization analysis, the sampling statistics analysis
method can provide an important reference for the e®ec-
tive implementation of the CBLP system.
An Analysis of the Working/Sleeping Decision inTopology Control of Wireless Sensor Networks
XIONG Yan, JIN Xin, MIAO Fuyou
2010, 19(1): 66-68.
Abstract(943) PDF(1037)
Abstract:
Most Topology control (TC) researches in
wireless sensor networks focus on speci¯c algorithms. This
paper proposes the problem that which criterion should
be adopted for the selection of Connectivity type TC and
Coverage type TC. By de¯ning \density of events" as the
decision criterion, the corresponding threshold values are
computed. Simulations indicate that the criteria analyzed
are directive and reasonable.
Layered Fuzzy Facial Expression Generation ofVirtual Agent
XUE Yuli, MAO Xia, CALEANU Catalin-Daniel, LV Shanwei
2010, 19(1): 69-74.
Abstract(827) PDF(1379)
Abstract:
To realize intelligent and comprehensive fa-
cial expression generation of virtual agent, a novel model
of layered fuzzy facial expression generation is proposed.
In this model, social, emotional and physiological lay-
ers contribute to the fuzzy facial expression generation.
Then, a layered fuzzy facial expression generation system
is founded, where in°uences of the three layers and ex-
pression personality are considered for intelligent decision
of facial expression generation based on fuzzy theory. A
novel layered fuzzy facial expression generation language
is also developed for conveniently controlling facial expres-
sion generation of virtual agent. The system is evaluated
by subjects and compared with other systems, showing
that it is e±cient for intelligent facial expression gener-
ation of virtual agent.
Layered Fuzzy Facial Expression Generation ofVirtual Agent
XUE Yuli, MAO Xia, CALEANU Catalin-Daniel, LV Shanwei
2010, 19(1): 75-80.
Abstract(941) PDF(1761)
Abstract:
To realize intelligent and comprehensive fa-
cial expression generation of virtual agent, a novel model
of layered fuzzy facial expression generation is proposed.
In this model, social, emotional and physiological lay-
ers contribute to the fuzzy facial expression generation.
Then, a layered fuzzy facial expression generation system
is founded, where in°uences of the three layers and ex-
pression personality are considered for intelligent decision
of facial expression generation based on fuzzy theory. A
novel layered fuzzy facial expression generation language
is also developed for conveniently controlling facial expres-
sion generation of virtual agent. The system is evaluated
by subjects and compared with other systems, showing
that it is e±cient for intelligent facial expression gener-
ation of virtual agent.
Vector Angle Minimum Criteria for Classi¯erSelection in Speaker Veri¯cation Technology
HOU Tao and LIU Jia
2010, 19(1): 81-85.
Abstract(889) PDF(1082)
Abstract:
Decision level fusion between classi¯ers
plays an increasingly important role in present speaker ver-
i¯cation technology, while on the other hand, it is not the
more classi¯ers involved in the fusion, the better the sys-
tem performs. This paper proposes the Vector angle min-
imum (VAM) criteria for the classi¯er selection in score
fusion of speaker veri¯cation system. The main idea is to
study the directions of the score-vectors in score space, ¯nd
the score-vectors which can form a minimum angle with
the standard-vector by linear combination, and take the
corresponding classi¯ers into the fusion. The experimen-
tal results show that the VAM-based selection can reduce
the needed number of classi¯ers obviously and enhance the
system performance. When compared to the n-best crite-
ria selection, the Equal error rate (EER) of the fused sys-
tem is relatively 7.2% lower when the number of selected
classi¯ers is 16.
Comparing the Performance of BiomimeticPattern Recognition with W8 and SVM onPrediction of Horizontal Gene Transfers inBacteria Genomes
CHEN Yang, WANG Shoujue
2010, 19(1): 86-90.
Abstract(1001) PDF(1106)
Abstract:
With the accomplishment of sequencing
genomes, lots of homologous genes had been found in dif-
ferent species. These homologous genes are called horizon-
tal transfer genes, in which genetic material is transferred
from the genome of one organism to another. Prediction of
the Horizontal gene transfers (HGT) has important mean-
ing for understanding the genome evolution and estimating
the hereditary material between species. A novel approach
based on Biomimetic pattern recognition (BPR) was pro-
posed to predict the horizontal gene transfers in bacte-
rial genomes. The basis of BPR points to the Principle
of homology-continuity (PHC) that the di®erence between
two samples of the same class must be gradually changed.
The aim of BPR is to ¯nd an optimal covering in the fea-
ture space, which rather than \division" in traditional pat-
tern recognition, emphasizing the \similarity" among ho-
mologous group members. Two neuron models called Hy-
per sausage neuron (HSN) and Ã3-neuron as covering units
in BPR were used to construct the multi-weighted neural
network. The performance of the approach was superior
to that of gene scoring method of 8-nucleotide composition
(W8) and one-class Support vector machine (SVM).
Genetic Algorithm Based Mapping and RoutingApproach for Network on Chip Architectures
GE Fen, WU Ning
2010, 19(1): 91-96.
Abstract(1039) PDF(2364)
Abstract:
A genetic algorithm based mapping and
routing approach called GAMR is proposed for low energy
design of 2D mesh based Network on chip (NoC) under
communication bandwidth constraint. The aim is to min-
imize total communication energy consumption and max-
imum link bandwidth of the NoC architecture. GAMR
automatically maps IP cores of given application onto
NoC architecture and generates a deterministic deadlock-
free minimal routing path for each communication trace.
The evaluation performed on various multimedia bench-
mark applications con¯rms the e±ciency of the proposed
approach. Experimental results show that GAMR saves
about 20% of energy consumption and 30% of link band-
width requirement on average compared to the existing
algorithms.
Low Complexity Semi-blind Bayesian IterativeReceiver for MIMO-OFDM Systems overTime-varying Multi-path Channels
XIONG Chunlin, WANG Degang, WEI Jibo
2010, 19(1): 97-102.
Abstract(972) PDF(1119)
Abstract:
Based on the Variational Bayes
expectation-maximization (VBEM) algorithm, a low com-
plexity semi-blind Bayesian iterative receiver with joint
signal detection and channel tracking is proposed for
MIMO-OFDM systems over time-varying multi-path chan-
nels. Since the VBEM algorithm provides the distribution
estimation of all parameters, the proposed signal detec-
tion algorithm is di®erent from the conventional ones in
that the evaluation of extrinsic information is improved by
considering channel estimation error in signal detection.
In addition, with the aid of the soft information provided
by the signal detector, the Recursive VBEM (RVBEM)
algorithm is derived to track the time-varying channels.
Due to the high complexity of the RVBEM algorithm, a
Time-frequency combined low complexity recursive VBEM
(TF-LCRVBEM) algorithm is further proposed to reduce
complexity. The analysis results demonstrate that the
TF-LCRVBEM algorithm totally avoids computation of
matrix inversion and obtains linear complexity. Moreover,
the simulation results show that the proposed receiver
outperforms the conventional receiver, and su®er small
performance loss at relatively high Signal-to-noise-ratios
(SNRs), compared with the optimal receiver with perfect
Channel state information (CSI).
Particle Swarm Optimization for Parallel MachineScheduling Problem with Machine EligibilityConstraints
HAO Jinghua, LIU Min, WU Cheng
2010, 19(1): 103-106.
Abstract(957) PDF(1435)
Abstract:
Particle swarm optimization is a popular
global optimization technology in continuous and discrete
optimization ¯elds in recent years. This paper presents
a particle swarm optimization-based scheduling algorithm
for large-scale parallel machine scheduling problem with
machine eligibility constraints and the objective of min-
imizing the total weighted tardiness. In the proposed
method, we ¯rst design a Machine assignment heuristic
(MAH) which is used to assign a processing machine of
each job based on the dynamic load-balancing mechanism,
and then we propose a particle swarm optimization algo-
rithm to optimize the sequence of all jobs in which MAH
is used in the decoding process of each particle, also, the
mechanisms of particle-moving and velocity-updating are
devised based on the problem characteristics. Numerical
computational results show that the proposed algorithm is
e®ective for large-scale parallel machine scheduling prob-
lems with machine eligibility constraints.
Slice Analysis Based Bayesian Power Model forSequential Circuits
CHEN Jie, TONG Dong, LI Xianfeng, XIE Jingsong, WANG Keyi, CHENG Xu
2010, 19(1): 107-112.
Abstract(891) PDF(857)
Abstract:
Bayesian modeling method and slice anal-
ysis techniques show good e®ect in cycle-accurate power
analysis of combinational circuit. In this paper, we use vir-
tual signal logical depth assignment to resolve the problem
that signal loop can not be sliced in sequential circuits.
With this method, we build cycle-accurate power model
based on Bayesian inference and slice analysis techniques.
The experiments on ISCAS89 benchmark show that the
power-per-cycle estimation error is 6.7%. By analyzing the
relation between error trend under di®erent slices and cir-
cuit's size, we also build a thumb rule about how to choose
best slice number: when the accumulative gate number
is about 73% of total gate number, the model error with
slice-based parameters usually arrives minimum value.
Congestion Control of Di®erentiated ServiceNetwork
XIAO Yang, KIM Kiseon
2010, 19(1): 113-118.
Abstract(995) PDF(1142)
Abstract:
The real application of Di®erentiated ser-
vices (Di®Serv) network requires the Di®Serv routers
to support di®erent data rates and time delays for the
subscribers with di®erent priorities. However, classical
routers and AQM algorithms for the routers can not meet
the requirements. To solve the problems, this paper de-
velops the schemes of Di®Serv edge router (DER) and
Di®Serv core router (DCR) with multiqueues, classi¯er
and scheduler and a Di®Serv AQM algorithm. The pro-
posed Di®Serv AQM algorithm based on DER can process
the heterogeneous and classi¯ed tra±c °ows. The Di®-
Serv AQM algorithm is derived from two theorems about
the congestion conditions of Di®Serv network in di®erent
links, it can prevent the possible congestion and ensure the
data rates and time delays for the subscribers with higher
priorities. The system simulations validate the proposed
Di®Serv routers and Di®Serv AQM algorithm.
An Improved File Delivery Protocol in SpaceNetworks
JIANG Xiaotian, LI Hongyan
2010, 19(1): 119-123.
Abstract(948) PDF(1235)
Abstract:
| The Consultative committee for space data
systems (CCSDS) File delivery protocol (CFDP) is a pro-
tocol speci¯cally designed to meet the comprehensive re-
quirements of space networks. However, CFDP's retrans-
mission mechanics in deferred mode reduce its link utiliza-
tion in space networks where long propagation delay and
high bit error rate exists. In this paper, we proposed an
improved ¯le delivery protocol called Relayed ¯le delivery
protocol (RFDP). RFDP adopts a relay transmission me-
chanics which raises the link utilization and reduces the
total ¯le delivery time. In the next place, we analyzed and
deduced the performance expressions of both protocols.
Finally, we made simulations to both CFDP and RFDP.
The results show that RFDP have performance superior-
ity over CFDP in space networks.
Discriminative Score Fusion for LanguageIdenti¯cation
ZHANG Weiqiang, HOU Tao, LIU Jia
2010, 19(1): 124-128.
Abstract(1058) PDF(1237)
Abstract:
Language identi¯cation (LID) has received
increasing interests in the speech signal processing com-
munity. With the rapid development of LID technologies,
how to fuse the score of multi-systems is growing to be a
researching focus. In this paper, we proposed a discrimina-
tive framework for LID score fusion. The Heteroscedastic
linear discriminate analysis (HLDA) technology is used for
dimension reduction and de-correlation, and the Gaussian
mixture model (GMM) trained with Maximum mutual in-
formation (MMI) criteria is used as classi¯er. Experiments
show that the proposed method can improve the perfor-
mance signi¯cantly. By score fusion of ¯ve systems, we
achieve average cost of 2.10% for 30s trials on the 2007
NIST language recognition evaluation databases.
Image Quality Evaluation Method Based onHuman Visual System
ZHAO Baojun, DENG Chenwei
2010, 19(1): 129-132.
Abstract(906) PDF(1752)
Abstract:
MSE, PSNR, SSIM and other traditional
objective image assessment metrics simply calculate sta-
tistical average results between original images and recon-
structed ones, which is incompatible with human visual
system. To address this issue, a joint subjective and ob-
jective image quality evaluation method is proposed. It has
the following features: ¯rstly, the subjective feelings of re-
constructed image are measured quantitatively in wavelet
domain; secondly, only noticeable visual distortion is uti-
lized in this model; lastly, based on di®erent character-
istics of spatio-temporal frequency response, eye-sensitive
wavelet coe±cients are enhanced, while those non-sensitive
ones are inhibited. Experimental results show that the pro-
posed model has simple structure and is easy-to-operate;
furthermore, it can re°ect the visual e®ects accurately and
objectively.
Improved Signi¯cant Vector Learning forParsimonious Regression
ZHAO Yongping and SUN Jianguo
2010, 19(1): 133-137.
Abstract(903) PDF(995)
Abstract:
Although the Signi¯cant vector (SV) re-
gression algorithm was proposed for constructing parsimo-
nious regression model, yet it can only ¯nd a suboptimal
solution. Hence, in this paper, an improved scheme is pro-
posed to boost the performance of the SV algorithm. The
Improved signi¯cant vector (ISV) algorithm without the
complicated regularization technique achieves as excellent
results as the Regularized SV algorithm (RSV), meantime
with less number of regressors. In addition, compared
with other algorithms, i.e., local regularization assisted or-
thogonal least squares (LROLS), Relevance vector machine
(RVM), and the Modi¯ed Gram-Schmidt (MGS), the ISV
algorithm is also favorable in the parsimoniousness. Fi-
nally, simulation examples validate the e®ectiveness and
feasibility of the ISV algorithm.
A Virtual Hypercube Routing Algorithm forWireless Healthcare Networks
HUO Hongwei, SHEN Wei, XU Youzhi, ZHANG Hongke
2010, 19(1): 138-144.
Abstract(1049) PDF(1370)
Abstract:
The application scenarios of wireless sensor
networks for health care systems are very complex, which
require a new communication schemes that can dynami-
cally ful¯ll these requirements and achieve e±cient data
transmission. It brings a big challenge to routing, access
control, data transmission, storage and processing. This
paper presents a novel routing scheme named Virtual hy-
percube routing (VHR), in which the routing selection and
maintenance rules are de¯ned based on a logical hypercube
structure. It can highlight good performance in data trans-
fer rate and query e±ciency. Based on this structure, the
routing for health care can be implemented e±ciently. We
evaluate the performance of VHR using simulation under
home and public area care scenarios. The results show that
this scheme performs high data transfer rate, low latency
and low overhead for communication under both static and
dynamic scenarios.
Study on Dynamic Spectrum Management Modelfor Interactive Cognitive Radio
MA Zhonggui, ZHOU Xianwei, WANG Hongbo, TU Xuyan
2010, 19(1): 145-149.
Abstract(957) PDF(1218)
Abstract:
In Interactive cognitive radio networks
(ICRN), secondary usage of spectrum is of competition and
con°ict, and radio frequency environment is time-varying.
In order to realize real-time secondary spectrum usage, we
propose architecture based on SoftMan for the ICRN. In
this architecture, the ICRN are divided into many coali-
tions according to geographical locations, utilization de-
gree of spectrum, frequency range and transmission power
level. In one coalition, a dynamic spectrum management
model based on di®erential games is proposed, and feed-
back Nash equilibrium solution to the non-cooperative dif-
ferential games is given and analyzed. Di®erential games
study a class of decision problems, under which the evolu-
tion of the state is described by a di®erential equation and
the players act throughout a time interval. So the model
can ensure real-time secondary spectrum usage. The simu-
lation results show that the model can improve e±ciency of
spectrum utilization, and re°ect realistically time-varying
radio frequency environment. It also constitutes the theo-
retical foundation for the spectrum management in a dy-
namic environment.
Performance Evaluation of a Single Carrier UWBSystem with MSE Channel Estimation
LI Yuhong, GE Ning, LU Jianhua
2010, 19(1): 150-154.
Abstract(932) PDF(1343)
Abstract:
This paper introduces a Single car-
rier Ultra-wideband (SC-UWB) transmission scheme with
Mean square error (MSE) channel estimation. Speci¯cally,
the scheme employs Direct sequence Binary phase shift
keying (DS-BPSK) to support high to moderate data rate
applications which di®erentiates from Multi-band Orthog-
onal frequency division multiplexing (MB-OFDM) and Im-
pulse radio (IR) UWB systems. Simulation results show
that, with baseband time-frequency signal processing al-
gorithms, the Bit error rate (BER) performance of the
SC-UWB system over the IEEE 802.15.3a UWB Chan-
nel model III (CM3) is about 10¡5 at Eb=N0 of 10.5dB.
Moreover, the SC-UWB system exhibits a low power con-
sumption and low implementation complexity due to its
low Peak-to-average ratio (PAR) and modulation charac-
teristics. It is evident that the scheme will be a good can-
didate for short range communications, especially for low
power and low cost applications such as mobile terminals.
Transmitter Identi¯cation in DVB-H System withSteganography Signal
HU Lingna, JIANG Lingge, HE Chen, YANG Feng
2010, 19(1): 155-158.
Abstract(926) PDF(1091)
Abstract:
Transmitter identi¯cation (TxID) tech-
nique is used to diagnose the operating status of radio
transmitters in DTV distributed transmission network. In
this paper, a new kind of TxID method for DVB-H system
is proposed. A steganography signal (e:g. watermark) is
embedded in the DVB-H signal to form the composite sig-
nal. By watermarking theory, we demonstrate the required
signal level for watermarking signal to achieve a given bit
error probability in di®erent circumstances. By selecting
the reference pattern to generate the watermarking signal,
Peak-to-average power ratio (PAPR) of the transmitted
signal can be improved. Simulation results show that dis-
tortion to the host signal can be ignored, and the receiver
can distinguish the watermarking signal with low embed-
ding strength even in wireless situation.
The Unique Distribution of Zeros in CompressingSequences Derived from Primitive Sequencesover Z=(pe)
ZHENG Qunxiong, QI Wenfeng
2010, 19(1): 159-164.
Abstract(925) PDF(993)
Abstract:
Let Z=(pe) be the integer residue ring with
odd prime p and integer e ¸ 3. Any sequence a over Z=(pe)
has a unique p-adic expansion a = a0+a1 ¢p+¢ ¢ ¢+ae¡1 ¢pe¡1,
where ai can be regarded as a sequence over Z=(p) for
0 · i · e ¡ 1. Let f(x) be a strongly primitive polynomial
over Z=(pe) and let a; b be two primitive sequences gener-
ated by f(x) over Z=(pe). Assume '(x0; ¢ ¢ ¢ ; xe¡1) = xe¡1 +
´(x0; ¢ ¢ ¢ ; xe¡2), where the degree of xe¡2 in ´(x0; ¢ ¢ ¢ ; xe¡2)
is less than p¡1. It is shown that if '(a0(t); ¢ ¢ ¢ ; ae¡1(t)) = 0
if and only if '(b0(t); ¢ ¢ ¢ ; be¡1(t)) = 0 for all nonnegative
integer t with ®(t) 6= 0, where ®, is an m-sequence de-
termined by f(x) and a0, then a = b. In particular, when
´(x0; ¢ ¢ ¢ ; xe¡2) = 0, it is just the former result on the unique
distribution of zeros in the highest level sequences.
Three-Step Carrier Frequency O®set EstimationAlgorithm for Burst-Mode Communications
LUO Wu, LIU An, LIANG Qinglin
2010, 19(1): 165-169.
Abstract(925) PDF(1608)
Abstract:
A data-aided frequency o®set estimation
algorithm suited for burst-mode communications is de-
scribed and analyzed. The proposed algorithm is based on
a Pilot symbol assisted modulation (PSAM) frame struc-
ture, which consists of regularly spaced pilot symbols and
a group of consecutive pilot symbols embedded in. Firstly,
an initial estimate based on consecutive pilot symbols is
generated for reducing the phase ambiguity. Secondly,
based on both spaced and consecutive pilot symbols, ¯ne
preliminary estimates are generated to improve estima-
tion accuracy. Lastly, the ¯nal estimate is obtained by
combining the ¯ne preliminary estimates with the initial.
This three-step algorithm is shown to provide high estima-
tion accuracy close to those of FFT-based algorithm at low
Signal-to-noise ratio (SNR). In addition, it is suitable for
high carrier frequency o®set cases.
Periodicity Impacts on the Accuracy in GreyModel Based Internet Tra±c Prediction
CUI Yidong, SUN Hanlin
2010, 19(1): 170-174.
Abstract(954) PDF(1066)
Abstract:
The Grey model (GM) is used to predict
Internet tra±c. The Mean relative error (MRE) of pre-
diction varies regularly when one of the parameters for
GM(1,1), the Modeling length, increases. Moreover, the
prediction error becomes unacceptable in some scenarios.
The reason lies in such facts: (1) The Internet backbone
tra±c exhibits multi-scale properties in temporal domain,
which results in periodical variation of the tra±c sequence;
(2) GM (1, 1) requires that the accumulated generating
sequence of the data should be the form of exponential
function. However, the periodicity of the tra±c sequence
violates the condition. In order to keep MRE acceptable,
the Modeling length should be far shorter than the Pe-
riod length. What's more, the accuracy of four models,
ARIMA, ENN, GM (1, 1) and Residual GM (1, 1), was
compared and we found that the Residual GM (1, 1) con-
tributes little to the prediction accuracy while it doubles
the computational complexity.
Data Aggregation-based Adaptive DataReproductive Delivery Scheme for Delay TolerantMobile Sensor Networks
ZHANG Ke, LIU Ming, ZHU Jinqi, SONG Jipeng, ZENG Jiazhi
2010, 19(1): 175-180.
Abstract(898) PDF(1440)
Abstract:
In Delay tolerant mobile sensor networks
(DTMSN), which is used for pervasive data gathering in in-
termittent connectivity network environment, traditional
data gathering methods can not be applied usefully. In
this paper, we propose a new data gathering method to re-
solve this problem. Simulation results shows that our pro-
posed data reproductive delivery scheme achieves higher
message delivery ratio with lower transmission overhead
and shorter data delivery delay compared with other data
delivering approaches for DTMSN.
Inter-carrier Interference Analysis and Mitigationfor OFDM System over Fast Fading Channels
PENG Yuexing, ZHAO Hui, WANG Wenbo
2010, 19(1): 181-186.
Abstract(954) PDF(1415)
Abstract:
Inter-carrier interference (ICI) due to
Doppler spread is analyzed for OFDM system in highly
mobile applications, and then an iterative ICI mitigation
method is developed. With the Jakes' model for the
Doppler power spectrum and linear model in one OFDM
symbol interval for time-varying channel, the analytical
closed-form expression of Signal-to-interference ratio (SIR)
and Signal-to-interference-plus-noise ratio (SINR) are de-
veloped with neither assumption on the statistical charac-
teristic of ICI nor constraint on the statistical model for
the fading channels. Then, a joint detection algorithm is
proposed to iteratively mitigate ICI and estimate channel
and detect symbols, where the ICI from a few neighbor-
ing interfering subcarriers which contribute the majority
of ICI power is regenerates and partially subtracted from
the received signal in order to mitigate decision error accu-
mulation. The number of concerned interfering subcarriers
and the optimal partial ICI cancellation factor are inves-
tigated for the tradeo® of complexity reduction and Mean
square error (MSE) minimization. Simulation results ver-
ify the proposed method can mitigate ICI e®ectively.
Analysis of Collision Probability in IEEE 802.11Based VANETs
WU Zhuang, YANG Yang, GUO Xun, AN Jianwei
2010, 19(1): 187-190.
Abstract(1046) PDF(1599)
Abstract:
Vehicular ad hoc network (VANET) is a
new type of ad hoc network with the characteristics of
highly dynamic topology, variable vehicle velocity and den-
sity. In the performance evaluation of VANETs, tradi-
tional collision probability model is not suitable because
it poorly re°ects these characteristics. This paper focuses
on the analysis of collision probability, which is a vital in-
gredient for any performance evaluation in IEEE 802.11
system. On the basis of collision probability in WLANs, a
new model is proposed to estimate collision probability in
VANETs, which integrates the characteristics of VANETs.
The model shows that the collision probability in VANETs
is no longer a constant value as in traditional model, but
a function of the factors re°ecting the characteristics of
VANETs. Simulation results using Network Simulator
2 (ns-2) show the validity and accuracy of the proposed
model.
Privacy Preserving Hop-distance Computation inWireless Sensor Networks
XIAO Mingjun, HUANG Liusheng, XU Hongli, WANG Yang, PEI Zegen
2010, 19(1): 191-194.
Abstract(928) PDF(1114)
Abstract:
How to protect the location privacy is an
important security issue in wireless sensor network. Pre-
vious works mainly focus on the routing-level location pri-
vacy problems. This paper however introduces a data-level
location privacy problem, i:e., the Privacy preserving hop-
distance computation (PPHC) problem, and proposes a
PPHC protocol to solve this problem. In this protocol, the
data disguise techniques in the secure multi-party compu-
tation ¯eld is successfully applied to protect the location
privacy of each participant. The most advantage of this
protocol is that it does not require any trusted third-party
or encryption operations, and thus has a much better per-
formance than the traditional solution generally based on
a trusted third-party and encryption operations. The per-
formance analysis shows that the computational overhead
of this protocol is only O(1), and the communication over-
head is dominated by two rounds of message delivery.