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Articles 1 - 18 of 18
Full-Text Articles in Social and Behavioral Sciences
Tunable Particle Focusing In A Straight Channel With Symmetric Semicircle Obstacle Arrays Using Electrophoresis-Modified Inertial Effects, Dan Yuan, Chao Pan, Jun Zhang, Sheng Yan, Qianbin Zhao, Gursel Alici, Weihua Li
Tunable Particle Focusing In A Straight Channel With Symmetric Semicircle Obstacle Arrays Using Electrophoresis-Modified Inertial Effects, Dan Yuan, Chao Pan, Jun Zhang, Sheng Yan, Qianbin Zhao, Gursel Alici, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
In this work, a novel microfluidic platform for tunable particle focusing in a straight channel with symmetric semicircle obstacle arrays using electrophoresis (EP)-modified inertial effects was presented. By exerting an EP force on the charged microparticles, a relative velocity gap between microspheres and fluid in a straight channel with symmetric semicircle obstacle arrays was implemented. The relative velocity and fluid shear will induce shear-slip lift force (Saffman lift force) perpendicular to the mainstream direction. Therefore, the focusing pattern can be altered using the electrophoresis-induced Saffman force. The effects of electric field direction, flow rate, electric field magnitude, and particle size …
Dean-Flow-Coupled Elasto-Inertial Three-Dimensional Particle Focusing Under Viscoelastic Flow In A Straight Channel With Asymmetrical Expansion-Contraction Cavity Arrays, Dan Yuan, Jie Zhang, Sheng Yan, Chao Pan, Gursel Alici, Nam-Trung Nguyen, Weihua Li
Dean-Flow-Coupled Elasto-Inertial Three-Dimensional Particle Focusing Under Viscoelastic Flow In A Straight Channel With Asymmetrical Expansion-Contraction Cavity Arrays, Dan Yuan, Jie Zhang, Sheng Yan, Chao Pan, Gursel Alici, Nam-Trung Nguyen, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, 3D particle focusing in a straight channel with asymmetrical expansion-contraction cavity arrays (ECCA channel) is achieved by exploiting the dean-flow-coupled elasto-inertial effects. First, the mechanism of particle focusing in both Newtonian and non-Newtonian fluids was introduced. Then particle focusing was demonstrated experimentally in this channel with Newtonian and non- Newtonian fluids using three different sized particles (3.2 lm, 4.8 lm, and 13 lm), respectively. Also, the effects of dean flow (or secondary flow) induced by expansion- contraction cavity arrays were highlighted by comparing the particle distributions in a single straight rectangular channel with that in the ECCA …
Clustered Multi-Channel Dereverberation For Ad Hoc Microphone Arrays, Shahab Pasha, Christian H. Ritz
Clustered Multi-Channel Dereverberation For Ad Hoc Microphone Arrays, Shahab Pasha, Christian H. Ritz
Faculty of Engineering and Information Sciences - Papers: Part A
A novel unsupervised multi-channel dereverberation approach in ad-hoc microphone arrays context based on removing microphones with relatively higher level of reverberation from the array and applying the dereverberation method on a subset of microphones with lower level of reverberation is proposed in this paper. This approach does not require any prior information about the number of microphones and their relative locations, however based on kurtosis of Linear Prediction (LP) residual signals, microphones located close to the active source are detected and utilized for the dereverberation process. The proposed method is a clustered enhancement method which can be applied with any …
Inertial Particle Separation By Differential Equilibrium Positions In A Symmetrical Serpentine Micro-Channel, Jun Zhang, Sheng Yan, Ronald Sluyter, Weihua Li, Gursel Alici, Nam-Trung Nguyen
Inertial Particle Separation By Differential Equilibrium Positions In A Symmetrical Serpentine Micro-Channel, Jun Zhang, Sheng Yan, Ronald Sluyter, Weihua Li, Gursel Alici, Nam-Trung Nguyen
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents an inertial microfluidic device with a simple serpentine micro-channel to continuously separate particles with high performance. Separation of micro/nano-particles has a variety of potential applications in biomedicine and industry. Among the existing separation technologies, a label-free technique without the use of antibody affinity, filter or centrifugation is highly desired to ensure minimal damage and alteration to the cells. Inertial microfluidics utilising hydrodynamic forces to separate particles is one of the most suitable label-free technologies with a high throughput. Our separation concept relies on size-based differential equilibrium positions of the particles perpendicular to the flow. Highly efficient separation …
Practical Fabrication And Analysis Of An Optimized Compact Eight-Channel Silicon Arrayed-Waveguide Grating, Hongqiang Li, Yaoting Bai, Xiaye Dong, Enbang Li, Yang Li, Wenqian Zhou, Yu Liu
Practical Fabrication And Analysis Of An Optimized Compact Eight-Channel Silicon Arrayed-Waveguide Grating, Hongqiang Li, Yaoting Bai, Xiaye Dong, Enbang Li, Yang Li, Wenqian Zhou, Yu Liu
Faculty of Engineering and Information Sciences - Papers: Part A
We have designed, fabricated, and characterized a 1 x 8 ultrasmall compact arrayed-waveguide grating (AWG) on silicon-on-insulator (SOI) in a fiber grating demodulation integration microsystem. The miniature AWG, consisting of Si photonic wire waveguides, was designed using the complete modeling simulation in the beam propagation method. The device was fabricated on an SOI substrate and evaluated in the wavelength range around 1.55 μm, with an effective area of 230 x 160 μm. Clear demultiplexing characteristics were observed with a channel spacing of 1.91 nm. The influence of the waveguide widths on crosstalk defined by adjacent channel crosstalk and phase error …
Net Section Tension Capacity Of Cold-Reduced Sheet Steel Channel Braces Bolted At The Web, Lip H. Teh, Benoit P. Gilbert
Net Section Tension Capacity Of Cold-Reduced Sheet Steel Channel Braces Bolted At The Web, Lip H. Teh, Benoit P. Gilbert
Faculty of Engineering and Information Sciences - Papers: Part A
This paper examines the accuracy of equations specified by the North American and Australasian steel structures codes for determining the net section tension capacity of a channel brace. It points out that there are three distinct factors affecting the net section efficiency of a cold-formed steel channel brace bolted at the web. These factors are the in-plane shear lag associated with stress concentration around a bolt hole that is also present in flat sheets, the out-of-plane shear lag that is also present in an I-section bolted at the flanges only, and the bending moment arising from the connection eccentricity with …
A General Compression Approach To Multi-Channel Three-Dimensional Audio, Bin Cheng, Christian Ritz, Ian Burnett, Xiguang Zheng
A General Compression Approach To Multi-Channel Three-Dimensional Audio, Bin Cheng, Christian Ritz, Ian Burnett, Xiguang Zheng
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a technique for low bit rate compression of three-dimensional (3D) audio produced by multiple loudspeaker channels. The approach is based on the time-frequency analysis of the localization of spatial sound sources within the 3D space as rendered by a multi-channel audio signal (in this case 16 channels). This analysis results in the derivation of a stereo downmix signal representing the original 16 channels. Alternatively, a mono-downmix signal with side information representing the location of sound sources within the 3D spatial scene can also be derived. The resulting downmix signals are then compressed with a traditional audio coder, …
Inertial Focusing In A Straight Channel With Asymmetrical Expansion-Contraction Cavity Arrays Using Two Secondary Flows, Jun Zhang, M Li, Weihua Li, Gursel Alici
Inertial Focusing In A Straight Channel With Asymmetrical Expansion-Contraction Cavity Arrays Using Two Secondary Flows, Jun Zhang, M Li, Weihua Li, Gursel Alici
Faculty of Engineering and Information Sciences - Papers: Part A
The focusing of particles has a variety of applications in industry and biomedicine, including wastewater purification, fermentation filtration, and pathogen detection in flow cytometry, etc. In this paper a novel inertial microfluidic device using two secondary flows to focus particles is presented. The geometry of the proposed microfluidic channel is a simple straight channel with asymmetrically patterned triangular expansion–contraction cavity arrays. Three different focusing patterns were observed under different flow conditions: (1) a single focusing streak on the cavity side; (2) double focusing streaks on both sides; (3) half of the particles were focused on the opposite side of the …
Does The Critical Shields Stress For Sediment Transport Depend On Channel-Bed Slope?, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar
Does The Critical Shields Stress For Sediment Transport Depend On Channel-Bed Slope?, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar
Faculty of Engineering and Information Sciences - Papers: Part A
This paper investigates why the observed critical Shields stress for incipient sediment motion deviates from the Shields curve. This deviation is often described in the literature as due to measurement errors and non-uniformity of channel-bed slope or flows. On the contrary, this paper hypothesises the deviation as due to the presence of vertical velocity in open channel flows. We found that the existence of vertical velocity in non-uniform flows can lead to the deviation of critical shear stress from the standard Shield's diagram that is valid only in uniform flows, and the channel bed slope could not contribute to the …
Discussion Of "Depth-Averaged Shear Stress And Velocity In Open-Channel Flows" By Shu-Qing Yang, M Sterling, Xiannan Tang
Discussion Of "Depth-Averaged Shear Stress And Velocity In Open-Channel Flows" By Shu-Qing Yang, M Sterling, Xiannan Tang
Faculty of Engineering and Information Sciences - Papers: Part A
The discussers thank the author for writing an informative and thought-provoking paper. Predicting the lateral distribution of boundary shear stress in open-channel flows is an intractable issue, and any theoretical work in this area is to be welcomed. The purpose of this discussion is twofold: first, to compare the analysis developed by the author to experimental data; and second, to seek clarification on several areas of potential confusion, which may be due to typographical errors.
Gmp‐Based Channel Estimation For Single‐Carrier Transmissions Over Doubly Selective Channels, Qinghua Guo, Defeng (David) Huang
Gmp‐Based Channel Estimation For Single‐Carrier Transmissions Over Doubly Selective Channels, Qinghua Guo, Defeng (David) Huang
Faculty of Engineering and Information Sciences - Papers: Part A
We present a graph-based channel estimation approach for SC-IFDE (single-carrier transmissions with iterative frequency domain equalization) without CP (cyclic prefix) over doubly selective channels using the recently developed Gaussian message passing (GMP) technique. A direct application of the GMP updating rules in the FFG (Forney-style factor graph) of the SC-IFDE system model incurs high complexity. Approximate updating rules are therefore developed to overcome this problem. The proposed GMP-based channel estimation approach has similar complexity as the low-complexity Kalman-filtering based frequency domain channel estimation approach in the literature, but significantly outperforms the latter due to its enhanced capability in capturing the …
A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping, Defeng (David) Huang
A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping, Defeng (David) Huang
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, we propose a low-complexity iterative joint channel estimation, detection and decoding technique for doubly selective channels. The key to the proposed technique is a segment-by-segment processing strategy under the assumption that the channel is approximately static within a short segment of a data block. Through a virtual zero-padding technique, the proposed segment-by-segment equalization approach inherits the low-complexity advantage of the conventional frequency domain equalization (FDE), but does not need the assistance of guard interval (for cyclic-prefixing or zero-padding), thereby avoiding the spectral and power overheads. Furthermore, we develop a low-complexity bidirectional channel estimator, where the Gaussian message …
A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping
A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, we propose a low-complexity iterative joint channel estimation, detection and decoding technique for doubly selective channels. The key is a segment-by-segment frequency domain equalization (FDE) strategy under the assumption that channel is approximately static within a short segment. Guard gaps (for cyclic prefixing or zero padding) are not required between adjacent segments, which avoids the power and spectral overheads due to the use of cyclic prefix (CP) in the conventional FDE technique. A low-complexity bi-directional channel estimation algorithm is also developed to exploit correlation information of time-varying channels. Simulation results are provided to demonstrate the efficiency of …
Reply To Comment By M. Bayani Cardenas And John L. Wilson On "Flow Resistance And Bed Form Geometry In A Wide Alluvial Channel", Shu-Qing Yang, Soon-Keat Tan, Siow-Yong Lim
Reply To Comment By M. Bayani Cardenas And John L. Wilson On "Flow Resistance And Bed Form Geometry In A Wide Alluvial Channel", Shu-Qing Yang, Soon-Keat Tan, Siow-Yong Lim
Faculty of Engineering and Information Sciences - Papers: Part A
The authors would like to thank Cardenas and Wilson [2006] for their valuable comments and interesting discussions.
Mimo-Ofdm Channel Estimation In The Presence Of Carrier Frequency Offset, Jun Y. Li, Guisheng Liao, Qinghua Guo
Mimo-Ofdm Channel Estimation In The Presence Of Carrier Frequency Offset, Jun Y. Li, Guisheng Liao, Qinghua Guo
Faculty of Engineering and Information Sciences - Papers: Part A
A multiple-input multiple-output (MIMO) wireless communication system with orthogonal frequency division multiplexing (OFDM) is expected to be a promising scheme. However, the estimation of the carrier frequency offset (CFO) and the channel parameters is a great challenging task. In this paper, a maximum-likelihood- (ML-) based algorithm is proposed to jointly estimate the frequency-selective channels and the CFO in MIMO-OFDM by using a block-type pilot. The proposed algorithm is capable of dealing with the CFO range nearly ±1/2 useful OFDM signal bandwidth. Furthermore, the cases with timing error and unknown channel order are discussed. The Cramér-Rao bound (CRB) for the problem …
Dynamic Channel Allocation For Mobile Cellular Systems Using A Control Theoretical Approach, Yaya Wei, Chuang Lin, Raad Raad, Fengyuan Ren
Dynamic Channel Allocation For Mobile Cellular Systems Using A Control Theoretical Approach, Yaya Wei, Chuang Lin, Raad Raad, Fengyuan Ren
Faculty of Engineering and Information Sciences - Papers: Part A
The guard channel scheme in wireless mobile networks has attracted and is still drawing research interest owing to easy implementation and flexible control. Dynamic guard channel schemes have already been proposed in the literature to adapt to varying traffic load. This paper presents a novel control-theoretic approach to dynamically reserve guard channels called PI-Guard Channel (PI-GC) controller that maintains the handoff blocking probability (HBP) to a predefined value; while it still improves the channel resource utilization.
An Adaptive Channel Tracking Method For Mimo- Ofdm Systems, Jun Tong, Yaohuan Gong, Shengxian Sun
An Adaptive Channel Tracking Method For Mimo- Ofdm Systems, Jun Tong, Yaohuan Gong, Shengxian Sun
Faculty of Engineering and Information Sciences - Papers: Part A
The tracking of the time-varying channel is crucial for MIMO-OFDM wireless communication systems. Aiming at doubly-selective fading MIMO channels, we present a novel pilot pattern and the corresponding adaptive channel tracking algorithm. Compared with the traditional pilot patterns, the new pattern has higher frequency efficiency and is more suitable for large transmit arrays. The computational complexity, frequency efficiency and BER performance of the system assisted by the proposed channel tracking scheme are analyzed. Simulation results demonstrate that the proposed scheme can track the timevarying channel effectively
The Dual Reciprocity Boundary Element Method For Magnetohydrodynamic Channel Flows, Song-Ping Zhu, Huan-Wen Liu
The Dual Reciprocity Boundary Element Method For Magnetohydrodynamic Channel Flows, Song-Ping Zhu, Huan-Wen Liu
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, we consider the problem of the steady-state fully developed magnetohydrodynamic (MHD) flow of a conducting fluid through a channel with arbitrary wall conductivity in the presence of a transverse external magnetic field with various inclined angles. The coupled governing equations for both axial velocity and induced magnetic field are firstly transformed into decoupled Poisson-type equations with coupled boundary conditions. Then the dual reciprocity boundary element method (DRBEM) [20] is used to solve the Poisson-type equations. As testing examples, flows in channels of three different cross-sections, rectangular, circular and triangular, are calculated. It is shown that solutions obtained …