• Kyungpook Mathematical Journal
• /
• v.55 no.3
• /
• pp.741-752
• /
• 2015

We introduce the warping crossing polynomial of an oriented knot diagram by using the warping degrees of crossing points of the diagram. Given a closed transversely intersected plane curve, we consider oriented knot diagrams obtained from the plane curve as states to take the sum of the warping crossing polynomials for all the states for the plane curve. As an application, we show that every closed transversely intersected plane curve with even crossing points has two independent canonical orientations and every based closed transversely intersected plane curve with odd crossing points has two independent canonical orientations.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.85.2-86
• /
• 2015

The YORP effect is non-gravitational force that changes the spin-status of asteroid. So far this effect has been directly detected only from the Near-Earth asteroids (Taylor et al. 2007; Lowry et al. 2007, 2014; Breiter et al. 2011; Durech et al. 2008, 2012). Pravec at el. 2008 found the evidences for changing spin rate of small asteroids (3 - 15 km) by the YORP effect in the Main-Belt and Mars-crossing asteroids. The Mars-crossing asteroids (1.3 < q < 1.66 AU) are objects that cross orbit of the Mars. The Mars-crossing asteroids are regarded as one of the main sources for the Near-Earth asteroids. We expect that rotation of Mars-crossing asteroids would be influenced by the YORP effect. We try to search observational evidence of the YORP effect for the Mars-crossing asteroid. Our target 2078 Nanking is a population of the Mars-crossing asteroid. First light-curve of 2078 Nanking was obtained from Mohamed et al. 1994, and Warner et al. 2015 recently published new observational data. We observed this asteroid on 26th Nov. 2014 and 17th Jan. 2015 using SOAO (Sobaeksan Optical Astronomy Observatory) 0.61 m telescope with 4K CCD. Using light-curve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we try to determine the pole orientation and shape model of this asteroid based on the combination of our light-curve and literature photometric data. Knowing spin parameters, such as rotational period and spin axis, are essential for studying the YORP effect. In this presentation, we provide some preliminary results of our recent study: light-curve and processing of shape modeling of 2078 Nanking. We plan to find observational clue for the YORP effect on the Mars-crossing asteroids.

• International Journal of Highway Engineering
• /
• v.16 no.1
• /
• pp.91-98
• /
• 2014

PURPOSES : Recently, there are increasing bicycle accidents along with increasing bicycles users. Bicycle accidents occurred frequently by perpendicular collision form at intersection inner. In order to improve safety of bicycle, drivers need to be aware of bicycles on the road and intersection geometric designs need to be designed to reduce risk associated with collisions between bicycles and car. This study aims to review the location of bicycle crossing in the viewpoint of bicycle safety. METHODS : Four types of bicycle crossing by curve radius and driver's check around the behavior are set to simulate the risk of collisions between bicycles and car turning right. Simulation using fortran programming are conducted on total 60 cases. RESULTS : Bicycle crossing located behind of crosswalk is lower the risk of collisions with car in all cases. In addition to the larger curve radius of pavement edge at intersection and the more pay attention to the rear by the turn head to the right is too low the risk of collisions with car. CONCLUSIONS : It is show that the location of bicycle crossing is safer behind than in front of crosswalk in the viewpoint of bicycle safety.

• The Korean Journal of Applied Statistics
• /
• v.33 no.5
• /
• pp.541-553
• /
• 2020

The receiver operating characteristic (ROC) curve is expressed as both sensitivity and specificity; in addition, some optimal thresholds using the ROC curve are also represented with both sensitivity and specificity. In addition to the sensitivity and specificity, the expected usefulness function is considered as disease prevalence and usefulness. In particular, partial the area under the ROC curve (AUC) on a certain range should be compared when the AUCs of the crossing ROC curves have similar values. In this study, partial AUCs representing high sensitivity and specificity are proposed by using sensitivity and specificity lines, respectively. Assume various distribution functions with ROC curves that are crossing and AUCs that have the same value. We propose a method to improve the discriminant power of the classification models while comparing the partial AUCs obtained using sensitivity and specificity lines.

• Geomechanics and Engineering
• /
• v.32 no.2
• /
• pp.179-191
• /
• 2023

To study the influences of tunneling on the earth pressure and ground settlement when the tunnel passes through the adjacent underground retaining structure, 30 two-dimensional model tests were carried out taking into account the ratios of tunnel excavation depth (H) to lateral width (w), excavation width (B), and excavation distance using a custom-made test device and an analogical soil. Tunnel crossing adjacent existing retaining structure (TCE) and tunnel crossing adjacent newly-built retaining structure (TCN) were simulated and the earth pressure variations and ground settlement distribution during excavation were analyzed. For TCE condition, the earth pressure increments, maximum ground settlement and the curvature of the ground settlement curve are negatively related to H/B, but positively related to H/s and H/w. For TCN condition, most trends are consistent with TCE except that the earth pressure increments and the curvature of ground settlement curve are negatively related to H/w. The maximum ground settlement is larger than that observed in tunnel crossing the existing underground structure. This study provides an assessment basis for the design and construction under confined space conditions.

• Journal of Multimedia Information System
• /
• v.9 no.3
• /
• pp.233-244
• /
• 2022

A MATLAB program was developed to calculate the half-wavelength of a sine-curve baseband signal with white noise by using an autocorrelation function, a SG filter, and zero-crossing detection. The frequency of the input signal can be estimated from 1) the first zero-crossing (corresponding to ¼λ) and 2) the R value (the Y axis of the correlogram) at the center of the segment. Thereby, the frequency information of the preceding segment can be obtained. If the segment size were optimized, and a portion with a large zero-crossing dynamic range were obtained, the frequency discrimination ability would improve. Furthermore, if the values of the correlogram for each frequency prepared on the CPU side were prepared in a table, the volume of calculations can be reduced by 98%. As background, period detection by autocorrelation coefficients requires an integer multiple of 1/2λ (when using a sine wave as the object of the autocorrelation function), otherwise the correlogram drawn by R value will not exhibit orthogonality. Therefore, it has not been used in bio-telemetry where the frequencies move around.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.2
• /
• pp.637-643
• /
• 2014

Recently there have been an increasing amount of bicycle accidents along with the increased usage of bicycles. Bicycle accidents occur frequently by perpendicular collision at the inner intersection. Bicycle traffic is especially concentrated in residential areas and around schools which results in the vulnerability of cyclists. This paper is to inform the potential risks of collisions between bicycles and cars turning right at the intersections using simulation analysis which focuses on the pavement edge of intersection geometric designs factor and checks on the drivers behavior. The result of the analysis shows that as the curve radius of pavement edge at the intersection becomes larger and the more attention drivers are paying to the rear by turning their heads to the right, the potential risk of collisions between bicycles and cars turning right will decrease.

• The Journal of the Korea Contents Association
• /
• v.5 no.6
• /
• pp.138-145
• /
• 2005

This paper describes a technique for detecting the boundary of the optic disk in digital image of the retina using inward and outward curve evolution. This paper offers medical information about glaucoma progresses. For accurate boundary detection, image inpainting based on texture synthesis removes blood vessels crossing the optic disk. For removing noises and preserving boundary of optic disk in image inpainting process, the anisotropic diffusion filtering is necessary. After pre-processing, the optic disk boundary is determined using inward and outward curve evolution. The experimental results show that the algorithm is effective for detection of optic disk boundary.

• Journal of information and communication convergence engineering
• /
• v.7 no.4
• /
• pp.545-550
• /
• 2009

A method fully utilizing multiscale line filter responses is presented to estimate the point spread function(PSF) of a CT scanner and diameters of small tubular structures based on the PSF. The estimation problem is formulated as a least square fitting of a sequence of multiscale responses obtained at each medical axis point to the precomputed multiscale response curve for the ideal line model. The method was validated through phantom experiments and demonstrated through phantom experiments and demonstrated to accurately measure small-diameter structures which are significantly overestimated by conventional methods based on the full width half maximum(FWHM) and zero-crossing edge detection.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.835-836
• /
• 2006

For non-contact structure vibration displacement measurement system, an algorithm for image processing using high speed CCD camera is introduced. The system sets the target to the structure, take picture using camera and image processing is performed to display the vibration data. The algorithm flow is basic preprocessing, projection data generation and curve fitting to find three crossing points for calibration or one center point in limited area.