Myunggyu Kim

Chiral corrections to the axial charges of the octet baryons from quenched QCD

Using quenched chiral perturbation theory, we calculate one-loop corrections to the axial charges of the octet baryons in the quenched approximation to quantum chromodynamics. The results are used to compare chiral corrections to the axial charges in full QCD chiral perturbation theory with those in quenched QCD. We find that the quenched chiral perturbation theory result

Automatic high-speed flying ball detection from multi-exposure images under varying light conditions

{c}_{0}^{Q}{+(c}_{l0}^{Q}{+c}_{l2}^{Q}{m}_{\ensuremath{\pi}}^{2})\mathrm{ln}{m}_{\ensuremath{\pi}}^{2}{+c}_{2}^{Q}{m}_{\ensuremath{\pi}}^{2}+\ensuremath{\cdot}\ensuremath{\cdot}\ensuremath{\cdot}

Smart vision system for soccer training

is singular in the chiral limit unlike the regular behavior of the full QCD chiral perturbation theory result

Efficient architecture for circle detection using Hough transform

{c}_{0}{+c}_{l2}{m}_{\ensuremath{\pi}}^{2}\mathrm{ln}{m}_{\ensuremath{\pi}}^{2}+\ensuremath{\cdot}\ensuremath{\cdot}\ensuremath{\cdot}.

A low cost high-speed infrared scanning system for flying ball detection

In this paper, we propose an automatic technique for high-speed flying ball detection from multi-exposure images under varying light conditions. The proposed technique is a two-step process. First, a new automatic image thresholding process is employed to obtain a preliminary ball region from a multi-exposure image, where a background subtraction method based on our spatial background model is combined to eliminate the effect of varying light conditions. Next, a bottom-up image labeling process is applied for obtaining an accurate segmentation of the final ball region. In addition, an efficient multi-grid scheme is introduced to accelerate the processing speed. The effectiveness and efficiency of the proposed technique was tested against previous methods with real experiments under various light conditions. Experimental results show that the proposed technique is capable of automatic and high-speed detection.

Soccer kick detection using a wearable sensor

This paper proposes a new smart vision system for soccer training. The proposed system adopts multi-exposure cameras to capture high-speed motion images of soccer ball instead of using high-tech or high-cost equipment. Then, new ball detection and motion analysis processes are adopted to detect the regions of soccer ball and analyze all motion parameters of soccer ball from those multi-exposed images of soccer ball in real time. The effectiveness of the proposed system is experimentally verified by comparing with a commercial ball motion sensor in terms of ball speed and spin rate. The usefulness and robustness of the proposed system is demonstrated by applying to an indoor soccer training platform in practice.

Articulated human motion tracking using a SOG-PF algorithm

This paper presents an efficient architecture for circle detection using Hough transform. The architecture adopts the scanline-based ball detection algorithm for the edge detection stage and edge-flag algorithm for the voting process. To bolster the performance of the voting process, when drawing a circle, we divide it into 16 sub-parts and compute the parts in parallel. The proposed design employs an internal memory block for the edge list. Our simulation results show that the benchmark images in the VGA size of 640 × 480 are processed within 10ms, which indicates that the proposed architecture can satisfy the speed requirements of most real world applications.

Motion capture with high-speed RGB-D cameras

This paper proposes a new ball tracking system for virtual sports. In the proposed system, multi-exposure cameras are used to capture high-speed motion images of ball. Then, a new iterative circle-fitting algorithm based on the circular Hough transform, the OFF-cell filter, and the Hausdorff distance is adopted to track balls with unknown patterns from images. The effectiveness of the proposed ball tracking system is verified through experiments using real balls with various patterns. The usefulness of the proposed system is demonstrated by applying to a virtual sports platform in practice.

A high-speed multi-exposure camera for virtual sports games

This paper presents a low cost high-speed infrared (IR) scanning system for detecting a flying ball. The system adopts a multi-scanline method using IR light-emitting diodes (LEDs) and photo-transistors (photo-TRs) arranged in straight lines on a rectangular frame. In order to avoid IR light interference, we put screens on receiver modules and drilled holes on photo-TRs to improve the feature of the light straight. Our test results for velocities in three dimensions show that the error rate is less than 10% compared to the velocities calculated by other available ball detection systems, which demonstrates that the proposed system is able to satisfy the requirements of most screen ball game simulators.