Extreme Learning Machine-Based Receiver for MIMO LED Communications

This work concerns receiver design for light-emitting diode (LED) multiple input multiple output (MIMO) communications where the LED nonlinearity can severely degrade the performance of communications. In this paper, we propose an extreme learning machine (ELM) based receiver to jointly handle the LED nonlinearity and cross-LED interference, and a circulant input weight matrix is employed, which significantly reduces the complexity of the receiver with the fast Fourier transform (FFT). It is demonstrated that the proposed receiver can efficiently handle the LED nonlinearity and cross-LED interference

Cylindrical Lenses Based Spectral Domain Low-Coherence Interferometry for On-line Surface Inspection

This paper presents a spectral domain low-coherence interferometry (SD-LCI) method that is effective for applications in on-line surface inspection because it can obtain a surface profile in a single shot. It has an advantage over existing spectral interferometry techniques because it uses cylindrical lenses as the objective lens in a Michelson interferometric configuration to enable the measurement of long profiles. The adjustable profile length in our experimental setup, determined by the NA of the illuminating system and the aperture of cylindrical lenses, is up to 10 mm. To simulate real-time surface inspection, large-scale 3D surface measurement was carried out by translating the tested sample during the measurement procedure. Two step height surfaces were measured and the captured interferograms were analysed using a fast Fourier transform algorithm. Both 2D profile results and 3D surface maps closely align with the calibrated specifications given by the manufacturer

White Light Channeled Spectrum Interferometry for the On-line Surface Inspection

In the industries making high volume as well as large area foil products and flexible electronics, the deposition and patterning of multi-layer thin films on large area substrates is often involved in the manufacturing processes. For these types of product, the films must be uniform and largely perfect across most of the area of the foil. To achieve a high product yield, the key challenge is to inspect the foil surface at production speed as well as have the sufficient resolution to detect the defects resulting from the coating and patterning processes. After the effective inspection, further process like local repair technique can be applied to remove the defects. We present a white light channeled spectrum interferometry (WLCSI) method that is effective for applications in on-line surface inspection because it can obtain a surface profile in a single shot. It has an advantage over existing spectral interferometry techniques by using cylindrical lenses as the objective lens in a Michelson interferometric configuration to enable the measurement of long profiles. The adjustable profile length in our experimental setup, determined by the NA of the illuminating system and the aperture of cylindrical lenses, is up to 10 mm. By translating the tested sample during the measurement procedure, fast and large-scale on-line surface inspection can be achieved. The performance of the WLCSI was evaluated experimentally by measuring step heights. The measuring results closely align with the calibrated specifications given by the manufacturer as well as the measurement results by the other commercial instrument, which demonstrate that the proposed WLCSI could be applied to production line like the R2R surface inspection, where only defects on the film surface are concerned in terms of the quality control

In-Situ Surface Inspection Using White Light Channelled Spectrum Interferometer

We introduce a new environmentally robust optical interferometry system for fast surface profile measurement. The proposed white light channelled spectrum Interferometer (WLCSI) is effective for applications in on-line surface inspection because it can obtain a surface profile in a single shot. Compared to the traditional spectral interferometry techniques, cylindrical lens is used in the Michelson interferometric objective of our system to achieve the measurement of long profiles. Combined with a modern high speed CCD camera, general-purpose graphics processing unit (GPGPU) and multi-core processors computing technology, large dynamic measurement with a high signal-to-noise ratio is realized. The designed prototype of WLCSI is presented and its performance was evaluated experimentally by measuring two surface samples. The measuring results closely align with the calibrated specifications given by the manufacturer as well as the measurement results by the other commercial instrument, which shows that the proposed WLCSI could be applied to production line like the roll-to-toll (R2R) surface inspection where only defects on the film surface are concerned in terms of the quality contro

Extreme Learning Machine Based Non-Iterative and Iterative Nonlinearity Mitigation for LED Communications

This work concerns receiver design for light emitting diode (LED) communications where the LED nonlinearity can severely degrade the performance of communications. We propose extreme learning machine (ELM) based non-iterative receivers and iterative receivers to effectively handle the LED nonlinearity and memory effects. For the iterative receiver design, we also develop a data-aided receiver, where data is used as virtual training sequence in ELM training. It is shown that the ELM based receivers significantly outperform conventional polynomial based receivers; iterative receivers can achieve huge performance gain compared to non-iterative receivers; and the data-aided receiver can reduce training overhead considerably. This work can also be extended to radio frequency communications, e.g., to deal with the nonlinearity of power amplifiers

Implementation of line-scan dispersive interferometry for defect detection

Surface assurance is one of the main concerns for advanced manufacturing technologies such as Roll-to-Roll (R2R) technique. The undesired defects present on the barrier films make R2R products suffer from a low efficiency and short life span. In order to enhance the performance and the yield of the products, an inspection system enabling in-line metrology of functional surfaces in production lines is desirable to optimise the manufacturing processes. This paper reports an instantaneous line-scan dispersive interferometry which has sufficient resolutions and nano-scale measurement repeatability to detect defects on flexible PV films. Free from any mechanical scanning and obtaining a surface profile in a single shot allows this setup to minimise environmental effects and to be used on the shop floor. The captured spectral interferogram is analysed using a FFT based algorithm, and the process time can be accelerated through data parallelism using a graphics processing unit (GPU). The performance of the developed system was evaluated experimentally by measuring the polyethylene naphthalate (PEN) films provided by the Centre for Process Innovation (CPI). The experimental details and results are presented in this paper

Supporting adaptive tour with high level petri nets

One of the issues for tour planning applications is to adaptively provide personalized advices for different types of tourists and tour activities. This paper proposes a high level Petri Nets based approach to providing some level of adaptation by implementing adaptive navigation in a tour node space. The new model supports dynamic reordering or removal of tour nodes along a tour path; it supports multiple travel modes and incorporates multimodality within its tour planning logic to derive adaptive tour. Examples are given to demonstrate how to realize adaptive interfaces and personalization. Future directions are also discussed at the end of this paper

Research on the Effects of International R&D on Carbon Productivity in China: Empirical Study Based on Dynamic Panel

At present, nearly 70% of the world's new increase carbon dioxide emission comes from China. Technology is the key power to develop low-carbon economy. Because of the shortage of independent　R & D and the relative backwardness of low-carbon technology,　Chinese need developed countries’ R&D capital and advanced technology to promote low-carbon technologies. Based on the panel data from Chinese 30 provinces from 2001 to 2014 and dynamic panel model, this paper researchs on the effects of international R&D on regional carbon productivity in China. The empirical results show that, the technology spillover effect of FDI and import trade can improve carbon productivity, and imported technology contracts play a positive role on carbon productivity, but not significant. There is a significant positive correlation between independent R&D and carbon productivity. Finally, the corresponding policy is put forward according to the conclusion