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Volume 14 No. 6
20 June 2009

2009, 14(6): 677-684.   doi:10.1016/S1007-0214(09)70134-8
Abstract ( 176 )  ( 55 )   Save
The benefit of a two-layer hybrid IP/MPLS (multi-protocol label switching) over a wavelength division multiplexing network has been analyzed considering both the cost and different grooming policies. A detailed cost and performance analysis of hybrid networks is done for three different grooming policies. The hybrid network cost is compared with that of an opaque network for equal traffic demand and equal blocking probability of dynamic requests of label switched paths. An algorithm is given to ...

2009, 14(6): 685-690.   doi:10.1016/S1007-0214(09)70135-X
Abstract ( 132 )  ( 47 )   Save
In recent years, face recognition has often been proposed for personal identification. However, there are many difficulties with face recognition systems. For example, an imposter could login the face recognition system by stealing the facial photograph of a person registered on the facial recognition system. The security of the face recognition system requires a live detection system to prevent system login using photographs of a human face. This paper describes an effective, efficient face liv...

2009, 14(6): 691-697.   doi:10.1016/S1007-0214(09)70136-1
Abstract ( 183 )  ( 59 )   Save
Packet losses usually result in frame losses in low bit rate video streaming over error prone networks. The whole frame error concealment (EC) algorithm is then necessary for the decoder to improve the video quality. A refined bidirectional motion vector extrapolation was developed to improve the motion vector estimation precision by alleviating the effect of overlapped and hole regions with an adaptive overlapped block motion compensation to reduce block artifacts. A prescription-based framewor...

2009, 14(6): 698-702.   doi:10.1016/S1007-0214(09)70137-3
Abstract ( 177 )  ( 44 )   Save
A complementary metal oxide semiconductor (CMOS) transconductor based on a high performance unity-gain buffer driving the degeneration resistor was used to obtain a highly linear voltage-to-current conversion with considerable reduction of the supply voltage. Simulations show that the transconductor using an 0.18-μm standard CMOS process with a 1.2-V supply voltage has less than −80 dB total harmonic distortion (THD) for a 1-MHz 0.4-Vp-p differential input signal. The third-orde...

2009, 14(6): 703-709.   doi:10.1016/S1007-0214(09)70138-5
Abstract ( 238 )  ( 68 )   Save
Objective evaluations of fused images are important in comparing the performance of different image fusion algorithms. This paper describes a structural similarity metric that does not use a reference image for image fusion evaluations. The metric is based on the universal image quality index and addresses not only the similarities between the input images and the fused image, but also the similarities among the input images. The evaluation process distinguishes between complementary information...

2009, 14(6): 710-717.   doi:10.1016/S1007-0214(09)70139-7
Abstract ( 130 )  ( 47 )   Save
Wireless communication and broadcasting convergence networks provide a potential solution to greater traffic throughput in the future. In this paper, the throughput of a convergence network is analyzed based on the standardization project for specific requirements for local and metropolitan area networks in China, referred to as broadband wireless multimedia systems. The convergence network is modeled as a combination of a broadcasting channel and a multi-access channel with interference. The th...

2009, 14(6): 718-724.   doi:10.1016/S1007-0214(09)70140-3
Abstract ( 165 )  ( 75 )   Save
A genetic clustering algorithm was developed based on dynamic niching with data attraction. The algorithm uses the concept of Coulomb attraction to model the attraction between data points. Then, the niches with data attraction are dynamically identified in each generation to automatically evolve the optimal number of clusters as well as the cluster centers of the data set without using cluster validity functions or a variance-covariance matrix. Therefore, this clustering scheme does not need to...

2009, 14(6): 725-731.   doi:10.1016/S1007-0214(09)70141-5
Abstract ( 194 )  ( 70 )   Save
In multi-user multiple-input single-output orthogonal frequency-division multiplexing (MISO-OFDM) downlinks with limited feedback, both linear precoders (LP) and Tomlinson-Harashima precoders (THP) experience performance degradation due to inaccurate channel state information at the transmitter (CSIT). This analysis treats the downlink channels as random quantities and exploits their second order statistics in robust precoding schemes to correct the errors introduced in the feedback procedure. T...

2009, 14(6): 732-734.   doi:10.1016/S1007-0214(09)70142-7
Abstract ( 262 )  ( 53 )   Save
The four-parameter lag-lead compensator design has received much attention in the last two decades. However, most approaches have been either trial-and-error or only for special cases. This paper presents a non-trial-and-error design method for four-parameter lag-lead compensators. Here, the compensator design problem is formulated into a polynomial function optimization problem and solved by using the recently developed sum-of-squares (SOS) techniques. This result not only provides a useful des...

2009, 14(6): 735-738.   doi:10.1016/S1007-0214(09)70143-9
Abstract ( 215 )  ( 31 )   Save
In most probabilistic teleportation schemes, if the teleportation fails, the unknown quantum state will be completely ruined. In addition, the frequently proposed high-dimensional unitary operations are very difficult to realize experimentally. To maintain the integrity of the unknown quantum state to be teleported, this analysis does not focus attention on the original multi-particle state but seeks to construct a faithful channel with an ancillary particle and a unified high-dimensional unitar...

2009, 14(6): 739-745.   doi:10.1016/S1007-0214(09)70144-0
Abstract ( 149 )  ( 80 )   Save
An important aim in pattern recognition is to cluster the given shapes. This paper presents a shape recognition and retrieval algorithm. The algorithm first extracts the skeletal features using the medial axis transform. Then, the features are transformed into a string of symbols with the similarity among those symbols computed based on the edit distance. Finally, the shapes are identified using dynamic programming. Two public datasets are analyzed to demonstrate that the present approach is bet...

2009, 14(6): 746-755.   doi:10.1016/S1007-0214(09)70145-2
Abstract ( 144 )  ( 50 )   Save
High-rise reinforced concrete buildings are in great demand in developing countries with rapid urbanization. Construction engineers are facing more and more safety control challenges. One major issue is the understanding of the load distributions, especially the maximum slab load, of structures under construction, which is time dependent. Previous methods were mainly targeted to specific examples, providing specific solutions without addressing the fundamental issues of finding general solutions...

2009, 14(6): 756-764.   doi:10.1016/S1007-0214(09)70146-4
Abstract ( 117 )  ( 63 )   Save
Site measurements have shown that slab loads re-distribute, between the slabs during the concrete curing, while the external loadings and structural geometry remain the same. Some have assumed that this is caused by concrete shrinkage and creep, but there have been no studies on how these factors exactly influence the load distributions and to what degree these influences exist. This paper analyzes the influences of concrete shrinkage, creep, and temperature on the load re-distributions among sl...

2009, 14(6): 765-775.   doi:10.1016/S1007-0214(09)70147-6
Abstract ( 182 )  ( 59 )   Save
A set of constrained Newton methods were developed for static traffic assignment problems. The Newton formula uses the gradient of the objective function to determine an improved feasible direction scaled by the second-order derivatives of the objective function. The column generation produces the active paths necessary for each origin-destination pair. These methods then select an optimal step size or make an orthogonal projection to achieve fast, accurate convergence. These Newton methods base...

2009, 14(6): 776-781.   doi:10.1016/S1007-0214(09)70148-8
Abstract ( 179 )  ( 58 )   Save
Off-ramp area congestion and off-ramp queue spill over are wide-spread reasons for expressway traffic jams in China. A control strategy was developed to reduce the number of collisions between expressway and surface street vehicles and to reduce spill over by controlling the surface street vehicles to improve the traffic conditions near expressway off-ramps. This control algorithm monitors the traffic conditions at the off-ramp using occupancy rates and a performance index for the surface street...

2009, 14(6): 782-794.   doi:10.1016/S1007-0214(09)70149-X
Abstract ( 131 )  ( 55 )   Save
Urban growth analysis and simulation have been recently conducted by cellular automata (CA) models based on self-organizing theory which differs from system dynamics models. This paper describes the Beijing urban development model (BUDEM) which adopts the CA approach to support urban planning and policy evaluation. BUDEM, as a spatio-temporal dynamic model for simulating urban growth in the Beijing metropolitan area, is based on the urban growth theory and integrates logistic regression and Mono...