3,308 research outputs found

    Analysis of Clipping Effect in Color Images Captured by CCD Cameras

    Get PDF
    Camera sensors (CCD) have a limited dynamic range that constrains the brightness of the incident light that can be quantified. In other words, if the ray of incident light is too intense, the sensor saturates and the value quantified is inadequately represented. This color clipping effect is a common problem in computer vision and it can become specially difficult when dealing with specular objects against a low-intensity background. In this paper, we present a method for analyzing such clipping effects of CCD cameras appearing in color images. Using an averaging technique to estimate the color of the illuminant, we define two types of axes in the RGB color cube: the Illumination Axis and the Clipping Axis. Our study concludes the followings: 1) the clipped pixels from a dielectric object form one or two lines, depending on the number of color channels on which the clipping effect takes place; and 2) these lines are parallel to the Clipping Axes. These two properties allow for a framework for a color-based segmentation that works even in the presence of saturated (specular) regions in the image. Moreover, the captured images can now be obtained under a wider variation of illumination conditions

    GAIT ANALYSIS OF THE NORMAL AND ACL DEFICIENT PATIENTS AFTER LIGAMENT RECONSTRUCTION SURGERY

    Get PDF
    Anterior cruciate ligament (ACL) injury of the knee is common in sports. A serious ACL injury leads to ligament reconstruction surgery. In order to evaluate result of surgery or optimize the rehabilitation process, a knee condition must be objectively identified. The purpose of this study is, therefore, to numerically indicate and classify knee condition of patients via the chaos analysis. Lyapunov exponents (LyEs) were used for the comparison of the normal and the patients

    Application of Recycled Zero-Valent Iron Nanoparticle to the Treatment of Wastewater Containing Nitrobenzene

    Get PDF
    Zero-valent iron (ZVI) was synthesized using iron oxide, a byproduct of pickling line at a steel work. ZVI with a mean particle size of 500 nm was synthesized. The reaction activity of the synthesized ZVI was much higher than commercial ZVI. When applied to the decomposition of nitrobenzene (NB), the ZVI particles underwent corrosion and passivation oxide film formation, resulting in particle size decrease. The NB decomposition rate increased with increasing ZVI dosage level and with decreasing pH. The solution pH increased monotonously with increasing reaction duration, whereas the aniline concentration showed a maximum at 50 min. Based on the GC/MS analysis, NB is presumed to be reduced into aniline via reductive intermediates such as azobenzene and azoxybenzene. When combined with a subsequent biological process, the synthesized ZVI will be able to decompose NB in wastewater effectively

    Voiding Dysfunction after Total Mesorectal Excision in Rectal Cancer

    Get PDF
    Purpose The aim of this study was to assess the voiding dysfunction after rectal cancer surgery with total mesorectal excision (TME). Methods This was part of a prospective study done in the rectal cancer patients who underwent surgery with TME between November 2006 and June 2008. Consecutive uroflowmetry, post-voided residual volume, and a voiding questionnaire were performed at preoperatively and postoperatively. Results A total of 50 patients were recruited in this study, including 28 male and 22 female. In the comparison of the preoperative data with the postoperative 3-month data, a significant decrease in mean maximal flow rate, voided volume, and post-voided residual volume were found. In the comparison with the postoperative 6-month data, however only the maximal flow rate was decreased with statistical significance (P=0.02). In the comparison between surgical methods, abdominoperineal resection patients showed delayed recovery of maximal flow rate, voided volume, and post-voided residual volume. There was no significant difference in uroflowmetry parameters with advances in rectal cancer stage. Conclusions Voiding dysfunction is common after rectal cancer surgery but can be recovered in 6 months after surgery or earlier. Abdominoperineal resection was shown to be an unfavorable factor for postoperative voiding. Larger prospective study is needed to determine the long-term effect of rectal cancer surgery in relation to male and female baseline voiding condition

    Effect of heavy metals on phenylpropanoid biosynthesis in Euonymus alatus

    Get PDF
    The productivity of the phenylpropanoid biosynthesis pathway in plants varies depending on the type of stress. In this work, we looked into how different phenylpropanoid chemicals accumulated in Euonymus alatus following exposure to different concentrations of CuCl2 (0.1, 0.5, and 1 mM), HgCl2 (0.1, 0.5, and 1 mM), and NiSO4 (10, 50, and 100 mM). We analyzed some of the individual phenolic chemicals by high-performance liquid chromatography (HPLC). In nearly all cases, rutin showed the largest concentration among the phenylpropanoid chemicals, followed by epicatechin, sinapic acid, p-coumaric acid, trans-cinnamic acid, ferulic acid, and caffeic acid. However, due to the change in the concentration of the heavy metals, the amount of phenylpropanoid changed. The highest accumulation of phenylpropanoid was documented in 0.1 mM CuCl2, whereas it was reduced in 1 mM HgCl2 exposed plants. These findings unequivocally demonstrate that the phenylpropanoid metabolic pathway took part in the heavy metal tolerance process, which shielded E. alatus from the oxidative damage brought on by heavy metals. Thus, under a variety of environmental stress situations, this species with a high tolerance to heavy metals may survive
    • …
    corecore