Optoelectronic implementation of mathematical morphology

An optoelectronic implementation based on optical neighborhood operations and electronic nonlinear feedback is proposed to perform morphological image processing such as erosion, dilation, opening, closing and edge detection. Results of a numerical simulation are given and experimentally verified.

Polarization analysis and experimental implementation of PLZT electro-optical switch using fiber Sagnac interferometers

The polarization characteristics of electro-optical (EO) switches using fiber Sagnac interferometer (FSI) structures are theoretically investigated. Analytical solutions of output fields are presented when the twists and birefringence in a Sagnac loop are considered. Numerical calculations show that the twists of fiber, the orientation of the inserted phase retarder, and the splitting ratio of the coupler will influence both the output intensity and the output polarization properties of the proposed switch. A polarization-independent EO switch based on a Sagnac interferometer and a PUT bar was experimentally implemented, which showed good coincidence with the analytical results. The experiment showed a switch with 22 dB extinction ratio and less than 31.1 ns switching time. (c) 2006 Optical Society of America.

Full-range parallel Fourier-domain optical coherence tomography using sinusoidal phase-modulating interferometry

We demonstrate a full-range parallel Fourier-domain optical coherence tomography (FD-OCT) in which a tomogram free of mirror images as well as DC and autocorrelation terms is obtained in parallel. The phase and amplitude of two-dimensional spectral interferograms are accurately detected by using sinusoidal phase-modulating interferometry and a two-dimensional CCD camera, which allows for the reconstruction of two-dimensional complex spectral interferograms. By line-by-line inverse Fourier transformation of the two-dimensional complex spectral interferogram, a full-range parallel FD-OCT is realized. Tomographic images of two separated glass coverslips obtained with our method are presented as a proof-of-principle experiment.

Dynamic full-range Fourier-domain optical coherence tomography using sinusoidal phase-modulating interferometry

We propose a technique for dynamic full-range Fourier-domain optical coherence tomography by using sinusoidal phase-modulating interferometry, where both the full-range structural information and depth-resolved dynamic information are obtained. A novel frequency-domain filtering algorithm is proposed to reconstruct a time-dependent complex spectral interferogram from the sinusoidally phase-modulated interferogram detected with a high-rate CCD camera. By taking the amplitude and phase of the inverse Fourier transform of the complex spectral interferogram, a time-dependent full-range cross-sectional image and depth-resolved displacement are obtained. Displacement of a sinusoidally vibrating glass cover slip behind a fixed glass cover slip is measured with subwavelength sensitivity to demonstrate the depth-resolved dynamic imaging capability of our system. (c) 2007 Society of Photo-Optical Instrumentation Engineers.

The Chinese rare minnow (Gobiocypris rarus) as an in vivo model for endocrine disruption in freshwater teleosts: a full life-cycle test with diethylstilbestrol

Chinese rare minnow (Gobiocypris rarus), a freshwater teleost,. was exposed to diethylstilbestrol (DES) at 0.05, 0.5, 1 and 5 mug/L from fertilized eggs for up to mature period under flow-through condition. Several endpoints that related to development, reproductive fitness and transgenerational effects were evaluated. It was found that body length and body weight were significantly reduced and vitellogenin (Via) levels were significantly increased for fish exposed to DES. Histological examination showed that the sex ratios of F-0 fish skewed to female and about 2% of the fish exposed to 0.05 mug/L DES developed testes-ova. The reproductive success, as determined from data on egg production, was reduced in female fish exposed to 0.05, 0.5, 1 and 5 mug/L DES. The lowest-observed-effect concentrations (LOEC) for chances of sex ratios, reproductive success and histology alteration of F-0 are 0.05 mug/L. In the offspring, transgenerational effects on egg hatching rate. egg fertilization and Vtg levels of juvenile individuals were not observed. However. survival of F, generation fry significantly declined. The analysis of sex steroid levels revealed a significant decrease of testosterone (T) in the whole body homogenates (WBH) of male progeny and somewhat elevation of estradiol (E-T) in the WBH of female offspring. These findings indicate that exposure to DES causes a variety of developmental, reproductive and transgenerational effects. (C) 2004 Elsevier B.V. All rights reserved.

A full spd tight-binding treatment for electronic bands of graphitic tubes

A tight-binding (TB) treatment with the inclusion of d orbitals is applied to the electronic structures of graphitic tubes. The results show that the high angular moment bases in TB scheme are necessary to account the severe curvature effect in ultra-thin single wall carbon nanotubes, especially for properly reproducing the band edge overlap behavior in (5, 0) tube, predicted by the existing ab initio calculations. In the large diameter limit, the participation of two synnmetry-allowed d bases provides a natural replication to the recent measured electronic dispersions of valence band of graphene when the strong anisotropy due to the two-dimensional planar hexagonal sheet structure is dealt with properly. In addition, the detailed relation between the two sets of quantum numbers of screw symmetry and that of zone folding is formulated in appendix. (C) 2008 Elsevier Ltd. All rights reserved.

Full-color emission from In2S3 and ln(2)S(3): Eu3+ nanoparticles

New observations on the luminescence Of In2S3 and europium-doped In2S3 nanoparticles show a green (5 10 nm) emission from In2S3 and In1.8Eu0.2S3 nanoparticles while a blue (425 nm) emission is observed from ln(1.6)Eu(0.4)S(3) nanoparticles. Both the blue and green emissions have large Stokes shifts of 62 and 110 nm, respectively. Excitation with longer-wavelength photons causes the blue emission to shift to a longer wavelength while the green emission wavelength remains unchanged. The lifetimes of both the green and blue emissions are similar to reported values for excitonic recombination. When doped with Eu3+, in addition to the broad blue and green emissions, a red emission near 615 nm attributed to Eu3+ is observed. Temperature dependences on nanoparticle thin films indicate that with increasing temperature, the green emission wavelength remains constant, however, the blue emission shifts toward longer wavelengths. Based on these observations, the blue emission is attributed to exciton recombination and the green emission to Indium interstitial defects. These nanoparticles show full-color emission with high efficiency, fast lifetime decays, and good stability; they are also relatively simple to prepare, thus making them a new type of phosphor with potential applications in lighting, flat-panel displays, and communications.

An improved TM method for full two-port calibration of the asymmetric test fixtures

Three known standards, including at least one transmission standard, are normally required for the full two-port calibration of test fixtures. Based on the triple-through method, a new general-purpose calibration procedure using only one known reflection standard is proposed in this paper. The experimental results show that our method call provide a simple and accurate approach to fall two-port calibration of the asymmetric test fixtures. (c) 2005 Wiley Periodicals, Inc.

Full counting statistics of transport through two-channel Coulomb blockade systems

A mesoscopic Coulomb blockade system with two transport channels is studied in terms of full counting statistics. It is found that the shot noise and skewness are crucially affected by the quantum mechanical interference. In particular, the super-Poisson behavior can be induced as a consequence of constructive interference, and can be understood by the formation of effective fast-and-slow transport channels. Dephasing and finite temperature effects are carried out together with physical interpretations.

A Novel Architecture of Vision Chip for Fast Traffic Lane Detection and FPGA Implementation

This paper presents a novel architecture of vision chip for fast traffic lane detection (FTLD). The architecture consists of a 32*32 SIMD processing element (PE) array processor and a dual-core RISC processor. The PE array processor performs low-level pixel-parallel image processing at high speed and outputs image features for high-level image processing without I/O bottleneck. The dual-core processor carries out high-level image processing. A parallel fast lane detection algorithm for this architecture is developed. The FPGA system with a CMOS image sensor is used to implement the architecture. Experiment results show that the system can perform the fast traffic lane detection at 50fps rate. It is much faster than previous works and has good robustness that can operate in various intensity of light. The novel architecture of vision chip is able to meet the demand of real-time lane departure warning system.

function definition language fdl and its implementation

A Function Definition Language (FDL) is presented. Though designed for describing specifications, FDL is also a general-purpose functional programming language. It uses context-free language as data type, supports pattern matching definition of functions, offers several function definition forms, and is executable. It is shown that FDL has strong expressiveness, is easy to use and describes algorithms concisely and naturally. An interpreter of FDL is introduced. Experiments and discussion are included.