Wuyishan, China
Wuyishan, China

Wuyi University is a university based in Wuyishan, Nanping county in Fujian province, China.The university was established in 1958 to offer undergraduate courses in the county. Wikipedia.

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Huang M.-W.,Wuyi University
Proceedings - 2010 3rd International Congress on Image and Signal Processing, CISP 2010 | Year: 2010

Sparse Representation-based Classification (SRC) is a newly introduced algorithm for face recognition, notable for its robust performance to occlusions and corruptions. Local Binary Patterns (LBP) is a very powerful method to describe the texture and shape of images. In this paper, we propose a novel method for facial expression recognition based on sparse representation of LBP features. Extensive experiments on Japanese Female Facial Expression (JAFFE) database are conducted. The experiment results show that the new method has a better performance than using Sparse Representation-based Classification solely on facial recognition, and is also better than those traditional algorithms such as Principal Component Analysis (PCA) and Linear discriminant analysis (LDA). ©2010 IEEE.

Metal-mirror microcavity (MMC) structure is incorporated into the low bandgap polymer solar cells (LBPSCs) by sandwiching the active layer between the semitransparent Ag electrode and top Ag electrode. Optical simulations demonstrate that significant absorption enhancement can be achieved in the red and near infrared (near-IR) wavelength range due to the large optical electric field confined by the MMC structure. By inserting optical spacers to control the spectral and spatial distribution of the electric field in the LBPSC devices, the MMC structure can improve the total absorbed photons (TAPs) at the red and near-IR spectral range (620900 nm) by 42.6% and yield an improvement of 14.0% in TAPs across the whole spectrum (400900 nm) for the device with a 100 nm-thick active layer. For devices with thinner active layer, the improving rate is significantly raised to over 100%. Additionally, it is revealed that the effects of the optical spacers on the electric field distribution vary with their positions in the MMC structure. Finally, the MMC-based devices are optimized by tailoring the electric field distribution in the devices. © 2011 Elsevier B.V. All rights reserved.

Long Y.,Wuyi University
Solar Energy Materials and Solar Cells | Year: 2010

Optical simulations based on transfer matrix method (TMM) have been performed to investigate the performance of inverted organic solar cells (IOSCs). The upper limit to photocurrent generation (Jscmax) has been calculated with the assumption that all photons absorbed by the active layer contribute to currents. The dependence of Jscmax on metal electrode reflections and thicknesses of hole transport layer (HTL), and electron transport layer (ETL) is investigated. The investigations indicate that metal electrode reflections and thicknesses of HTL and ETL strongly affect the Jscmax for IOSC devices with active layer of thickness below 60 nm, but these effects are weak for devices with active layer of thickness above 200 nm. Furthermore, the HTL inserted between the active layer and the metal electrode acts as an optical spacer and significantly improves Jscmax in thin active layers (<60 nm). In particular, the improvement of Jscmax is weaker in devices with an Ag electrode than those with an Al electrode. Finally, optimization of the power conversion efficiency is carried out by tailoring the layer thicknesses of HTL and ETL. © 2009 Elsevier B.V. All rights reserved.

Due to the movement and complexity of the carbon market, traditional monoscale forecasting approaches often fail to capture its nonstationary and nonlinear properties and accurately describe its moving tendencies. In this study, a multiscale ensemble forecasting model integrating empirical mode decomposition (EMD), genetic algorithm (GA) and artificial neural network (ANN) is proposed to forecast carbon price. Firstly, the proposed model uses EMD to decompose carbon price data into several intrinsic mode functions (IMFs) and one residue. Then, the IMFs and residue are composed into a high frequency component, a low frequency component and a trend component which have similar frequency characteristics, simple components and strong regularity using the fine-to-coarse reconstruction algorithm. Finally, those three components are predicted using an ANN trained by GA, i.e., a GAANN model, and the final forecasting results can be obtained by the sum of these three forecasting results. For verification and testing, two main carbon future prices with different maturity in the European Climate Exchange (ECX) are used to test the effectiveness of the proposed multiscale ensemble forecasting model. Empirical results obtained demonstrate that the proposed multiscale ensemble forecasting model can outperform the single random walk (RW), ARIMA, ANN and GAANN models without EMD preprocessing and the ensemble ARIMA model with EMD preprocessing. © 2012 by the authors; licensee MDPI.

Ou J.,Wuyi University
Match | Year: 2010

Three graph-transformations are introduced for maximizing the total number of matchings of a graph, by which chemical trees that have maximal energy and any prescribed maximum vertex-degree are characterized. Orderings of n-vertex chemical trees are presented according to their energy, some of which contain approximate n trees. Finally, acyclic graphs with maximal energy but without perfect matchings are also characterized.

Lu D.,Wuyi University
Guangxue Xuebao/Acta Optica Sinica | Year: 2014

The three-mode squeezed vacuum state is proposed by using of a new three-mode squeezing operator acting on a three-mode vacuum state. With two of the three modes measured, the influence of the selective measurement on squeezing effect, antibunching effect and photon statistical distribution of the third mode is discussed. The results obtained show that on the one hand, if the first and the second modes are selectively measured in a two-mode squeezed state, the state vector of the third mode collapses onto single-mode squeezing state and squeezing of the third mode is strengthened. On the other hand, nonclassical properties of photon statistical distribution is strongthened by measuring the quantum state, which has no effect on antibunching of the third mode.

Phase adjustment is employed to redistribute the optical electric field and improve the optical absorption for semitransparent organic solar cells with one-dimensional photonic-crystals. Simulations reveal that tailoring the reflection phase shift of the one-dimensional photonic-crystals can shift the active layer into the electrical maximum region where it is most beneficial for photon absorption. With appropriate adjustment of the reflection phase shift, the optical absorption within the blue and near-infrared wavelength ranges can be improved simultaneously and yield an improvement of 112.5 in the total absorbed photons for the devices. In addition, the average transmission remains 71.1 across the visible wavelength range of 470 nm-700 nm. © 2011 American Institute of Physics.

A two-mode moderate microcavity (MM) structure has been constructed to confine large optical electric field in the low band gap polymer solar cells by inserting a titanium dioxide (TiO 2) layer into the devices. Simulations demonstrate the two-mode MM can significantly improve the light absorption at two discrete wavelength ranges and yield an improvement of about 13.8% in total absorbed photons (TAPs) for the device with a 60 nm thick active layer. Combined with an optical spacer, the MM structure leads to a larger improvement of 32.8% in TAPs. The efficacy of the MM structure is revealed to be strongly dependent on the active layer thickness. © 2011 American Institute of Physics.

In this paper, we explore a diimine ligand of 2-thiazol-4-yl-1H- benzoimidazole (TB) with strong electron donors in its molecule. In addition, an excess electron-donor moiety of carbazole is incorporated through an inert alkyl chain to form another diimine ligand of 1-(4-carbazolylbutyl)-2-thiazol-4- yl-1H-benzoimidazole (CTB). Their corresponding Cu(I) complexes are synthesized as well. Experimental data confirm that both the Cu(I) complexes are high-energy-emitting ones. What is more, it is found that the emitter's photoluminescent and thermal performances can be greatly improved when active hydrogen is eliminated. Using the CTB-based Cu(I) complex as a dopant, we realize green-emitting devices with a maximum brightness of 1500 cd/m 2 peaking at 525 nm, and the device efficiency roll-off in these devices is largely depressed due to the shield provided by carbazole moiety. © 2010 Elsevier B.V.

Lu D.-M.,Wuyi University
International Journal of Theoretical Physics | Year: 2013

This paper discusses the entanglement dynamics of a coupled cavity quantum electrodynamics (CQED) setup, which comprises three two-level atoms resonantly interacting with three cavities that are coupled by two optical fibers. The influences of atom-cavity coupling constant on the entanglement between atoms and that between cavities are discussed. The results obtained from the numerical method show that the entanglement between non-adjacent atoms or that between adjacent cavities has a nonlinear relation with increasing of the atom-cavity coupling coefficient. On the other hand, the entanglement between non-adjacent cavities is strengthened and the entanglement between adjacent atoms is weakened with increasing of atom-cavity coupling constant. © 2013 Springer Science+Business Media New York.

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