Detecting the wheel pattern of a vehicle using stereo images

This paper presents a method for detecting the wheels of a vehicle in stereo image pairs. The method consists of two steps: (i) geometrical transformation; and (ii) circle extraction. The geometrical transformation uses the disparity values obtained from a stereo image pair to calculate the parameters of the plane containing wheels of the vehicle. By using these parameters, we transform any elliptical wheels contained in the plane to circular ones which can be extracted by the circle extraction algorithm. The circle extraction algorithm consists of (1) template matching and (2) Hough transform. In order to save computation and improve the results in the Hough transform, we employ two constraints (a) the neighbor-region edge connectivity and (b) the gradient direction of each edge point, to eliminate non-circular edge points. Experimental results show that these two constraints do eliminate non-circular edge points and preserve any circle embedded in edges. From the final results, we can observe that our method can detect and locate the wheels of a vehicle successfully.     

An integrated translation of design data of a nuclear power plant from a specification-driven plant design system to neutral model data

How to efficiently integrate and manage lifecycle data of a nuclear power plant has gradually become an important object of study. Because plants usually have a very long period of operation and maintenance, the plant design data need to be presented in a computer-interpretable form and to be independent of any commercial systems. The conversion of plant design data from various design systems into neutral model data is therefore an important technology for the effective operation and maintenance of plants. In this study, a neutral model for the efficient integration of plant design data is chosen from among the currently available options and extended in order to cover the information model requirements of nuclear power plants in Korea. After the mapping of the neutral model and the data model of a specification-driven plant design system, a plant data translator is also implemented in accordance with the schema mapping results.     

Simple synthesis of ZnS nanoparticles in alkaline medium

ZnS nanoparticles were successfully synthesized by reflux under an alkaline medium. The nanoparticles were characterized by using X-Ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical properties of ZnS nanoparticles were examined by photoluminescence (PL) spectrum. The result shows that the as-synthesized ZnS nanoparticles had a cubic phase. SEM image shows that ZnS nanoparticles are basically in spherical shape and are homogeneous. The particle size was found to be in the range of 18 nm.     

Mesh-offset-based method to generate a delta volume to support the maintenance of partially damaged parts through 3D printing

Journal of Mechanical Science and Technology - Three-dimensional (3D) printing technology is an excellent tool for implementing multi item, small scale production or for manufacturing objects of...     

High-peak-power 2nd-harmonic l.s.a. sources

Results are presented which indicate that the upper frequency range of l.s.a. oscillators can be extended by extracting power at the 2nd-harmonic frequency. By selectively loading the 2nd-harmonic frequency of an X-band l.s.a. oscillator, up to 170 W peak power with 4.8% efficiency at 17.5 GHz has been obtained.     

Extrusion coating performances of iPP/LDPE blends

The performance of iPP/LDPE blends in an extrusion coating process was investigated in the terms of coating width and draw‐down ability. It is well known that iPP alone is not proper because of lower draw‐down ability with severe draw resonance in elongational flow. To obtain higher draw‐down ability, iPP was blended with LDPE. Additionally, iPPs having different molecular weight distribution (MWD) were used in this study to find out the effect of MWD of iPP on neck‐in and draw‐down ability. It was observed that iPP/LDPE blend with narrower MWD exhibits narrower coating width and higher draw‐down ability. Neck‐in and draw‐down ability were correlated with shear and elongational properties obtained by several rheological measurements. From this study, the major rheological parameters affecting extrusion performance in iPP/LDPE blends could be assessed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Characterization and Wideband Modeling of Miniaturized LTCC Helical Inductors

We report fabrication of miniaturized low temperature co-fired ceramic helical (3-D) inductors with more than seven layers of helices and the conductor linewidth of 100mum. We achieve the Q_maxLeff/A product ranging from 200 to 370. Such high values are possible thanks to the drastic reduction of the active area and still acceptably large Q_max and self-resonant frequency. High frequency characterization of the inductors is performed up to 12GHz, and a new equivalent circuit model considering vertical electromagnetic coupling between conductors is shown to reproduce all the measured characteristics     

1/f noise of GaAs resistors on semi-insulating substrates

A new theory is used to analyze the 1/f noise of GaAs resistors on semi-insulating substrates. It is demonstrated that this model can explain previously published results at moderately high frequencies for, in this example, resistive filaments on semi-insulating GaAs substrates. The model is based on a distributed equivalent circuit representation of the substrate, and shows that 1/f noise is a bulk phenomenon associated with the high resistivity substrates. The 1/f noise is not associated with number or mobility fluctuations in the channel, nor surface effects. One consequence of the theory is that in this particular instance Hooge's parameter is in reality no parameter, but is given by a simple formula which has a simple physical interpretation as the ratio of two charges: the thermal charge developed across the substrate capacitance and the charge associated with ionized donors in the resistor channel