Abstract: To monitor the wear and degradation on a pipe by corrosion during a plant operation, the
vibration signals were measured by an accelerometer and analyzed by several analysis techniques.
From the conventional methods, it was difficult to identify the wear and degradation on the pipe. And
hence, the time-frequency distribution (TFD) and the adaptive cone-kernel distribution (ACKD)
devised for reducing the interfering cross-terms are applied to the acquired data. They can provide the
distinguishing peak patterns between the normal and corrosion signals.
Abstract: H.264/AVC is adopted as a next generation moving picture compression standard.
Context-based Adaptive Binary Arithmetic Coding (CABAC) is the major entropy coding algorithm
employed in H.264/AVC. Although the performance gain of H.264/AVC is mostly resulted from
CABAC, it is difficult to implement a high-throughput decoder due to its decoding complexity.
Although CABAC excludes a multiplication, the algorithm is basically sequential and needs large
computations to compute some important variables, which are range, offset and context variables.
Therefore, it is difficult to achieve fast decoding performance. In this paper, a prediction scheme is
proposed to decode maximally two bits at a time and thus to reduce overall decoding time. A CABAC
decoder based on the proposed prediction scheme reduces total cycles by 24% compared to
Abstract: A key requirement in most ultrasonic weld inspection systems is the ability for rapid
automated analysis to identify the type of flaw. Incorporation of spatial correlation information from
adjacent A-scans can improve performance of the analysis system. This paper describes two neural
network based classification techniques that use correlation of adjacent A-scans. The first method
relies on differences in individual A-scans to classify signals using a trained neural network, with a
post-processing mechanism to incorporate spatial correlation information. The second technique
transforms a group of spatially localized signals using a 2-dimensional transform, and principal
component analysis is applied to the transform coefficients to generate a reduced dimensional feature
vectors for classification. Results of applying the proposed techniques to data obtained from weld
inspection are presented, and the performances of the two approaches are compared.
Abstract: This paper proves that the energy centre of symmetric window function is the coordinate
origin in discrete spectrum analysis. The correction formula of frequency, amplitude and phase can be
obtained using this character. Simulation demonstrates that this method can correct averaged power
spectrum directly with simple algorithm and fast processing speed, and the interference of negative or
narrow interval frequencies has little influence on correction precision. This method is suitable for all
kinds of symmetric window. But it is not suited with dense frequencies signal or continuous spectrum.
Abstract: A technique to localize an impact source for an elastic spherical shell is proposed. The
conventional source localization techniques when the source is located on a dispersive medium, require
both the time-of-arrival differences (TOADs) between the transducer signals and the group velocities. In
practice, the material properties or the geometry of the medium are not fully informed, therefore the
group velocity is not available. Furthermore, they are only applicable if we have a high signal-to-noise
ratio (SNR). In this paper, we propose a method that can be applicable in practice, which does not need
to know the group velocity, when we have a relatively small SNR. The scanning procedure over the
structure to acquire a minimum variance point of the estimated group velocities is suggested. To reduce
the noise effect, an exponential function is asymmetrically weighted in smoothed Wigner-Ville
distributions (WVDs). Experiments have been conducted to confirm the validity of this method. As a
result, the proposed technique is found to be effective for an impact source localization for a spherical
shell without prior information on the group velocity, even in a noisy environment.
Abstract: The behavior of liquid in containers subjected to impact loads due to free fall was
investigated using a visualization technique. Two types of containers were used. One consisted of a
case made of transparent plastic plates and a liquid-packing bag made of transparent plastic films. The
bag contained about 1,000 ml of liquid. The other was a case made only of transparent plastic plates.
The case contained about 1,000 ml of water. The liquid consisted of water and ethanol. Polyethylene
particles of about 3 mm in diameter were included in the liquid to visualize the movement of liquid in
the containers. The containers were subjected to impact due to free fall, and photographs of the
containers were taken using a high-speed camera. Results indicated that the behavior of liquid in the
container with a liquid-packing bag is different from that of the container without a liquid-packing
Abstract: A three-step phase shifting approach for automatic determination of the isoclinic
parameter in photoelasticity is presented. Unreliable isoclinic values affected by the isochromatic
parameter are solved using the white light. The method uses three fringe images digitally captured
by a digital camera for three different configurations of the dark-field plane polariscope. For a
circular disk under compression, results show the method permits the isoclinic parameter in the
range -π/2 to π/2 with almost free of the isochromatic parameter and comparable with theory.
Abstract: Many visual automatic inspection methods are used in the assembly line of vehicles for
improving quality and reducing a production cost. In order to resolve uneasy inspection problems,
new useful methods and devices have been developed. A real factory environment has very poor
optical conditions. Illuminations are affected by the sun lights passing through the windows of the
factories. The floor is continuously vibrating, which could affect the posture of installed cameras and
illumination devices. This paper describes how to overcome these problems and suggests the
automatic inspection system applicable to the automobile assembly line. It introduces two feature
extraction methods and algorithms to detect the opened car in the automobile assembly line. The
methods for extracting these features are discussed in this paper with the experimental results.
Abstract: Ultrasonic C-scan inspections have been used in various industrial fields. Usually,
conventional ultrasonic C-scan systems have several mechanical manipulating axis controlled by a
computer or an electronic device. These systems are suitable for the high resolution and inspection
quality. But they are too heavy and bulky to carry in general, and many industrial fields do not require
higher resolution than a hundred micron order. To take care of such a need, in this study we developed
an ultrasonic C-scan system that does not have any mechanical manipulator to transport ultrasonic
transducers. This system, named "M-Scanner", adopts an electro-magnetic position tracking sensor
instead of mechanical manipulating axes in order to trace the transducer position. Furthermore, this
new system is portable and has a reasonable construction cost along with practical inspection
resolution required in many industrial field inspections.
Abstract: A color space used to create color on a computer monitor or a television screen is RGB
color space. However, RGB color space is strongly related to each other, therefore RGB color space is
inadequate for adjustment of brightness or contrast. Moreover RGB color space is not suitable for
pattern recognition. For this reason, it is needed that color space conversion from RGB to YIQ, YUV
or YCrCb. The color space conversion matrix consists of 3 by 3 matrix element that is represented by
floating point numbers. However RGB or YUV color space is in integer domain. Therefore these
transform lead to lose the least significant bit (LSB) of color space. We propose the simple and fast
reversible transform matrix. No lose the least significant bit (LSB) and not required multiplication but
shift and addition that provides for real time conversion of huge image.