• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.150-161
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• 2013

This paper presents a new system which produces high resolution 3D contents by capturing multiview images of an object using multiple cameras, and estimating geometric and texture information of the object from the captured images. Even though a variety of multiview image-based 3D reconstruction systems have been proposed, it was difficult to generate high resolution 3D contents because multiview image-based 3D reconstruction requires a large amount of memory and computation. In order to reduce computational complexity and memory size for 3D reconstruction, the proposed system predetermines the regions in input images where an object can exist to extract object boundaries fast. And for fast computation of a visual hull, the system represents silhouettes and 3D-2D projection/back-projection relations by chain codes and 1D homographies, respectively. The geometric data of the reconstructed object is compactly represented by a 3D segment-based data format which is called DoCube, and the 3D object is finally reconstructed after 3D mesh generation and texture mapping are performed. Experimental results show that the proposed system produces 3D object contents of $800{\times}800{\times}800$ resolution with a rate of 2.2 seconds per frame.

• Geomechanics and Engineering
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• v.4 no.3
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• pp.219-227
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• 2012

Pavement management systems require systematic monitoring of pavement surfaces to determine preventive and corrective maintenance. The process involves the accumulation of large amounts of visual data, typically obtained from site visitation. The pavement surface condition is then correlated to a pavement distress index that is based on a scoring system previously established by state or federal agencies. The scoring system determines if the pavement section requires maintenance, overlay or reconstruction. One of the surface distresses forming part of the overall pavement distress index is the Alligator Crack Index (AC Index). The AC Index involves the visual evaluation of the crack severity of a section of a pavement as being low, medium, or high. This evaluation is then integrated into a formula in order to obtain the AC Index. In this study a quantification of the visual evaluation of the severity of alligator cracking is carried out using photographs and the fractal dimension concept from fractal theory. Pavements with low levels of cracking were found to have a fractal dimension equal to 1.051. Pavements with moderate levels of cracking had a fractal dimension equal to 1.1754. Pavements with high degrees of cracking had a fractal dimension that varied between 1.5037 (high) and 1.7111 (very high). Pavements with a level of cracking equal to 1.8976 represented pavements that disintegrated and developed potholes. Thus, the visual evaluation of the state of cracking of a pavement (the AC Index) could be enhanced with the use of the fractal dimension concept from fractal theory.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.129-135
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• 2022

Real human digital models appear more and more frequently in VR/AR application scenarios, in which real-time markerless face capture animation of personalized virtual human faces is an important research topic. The traditional way to achieve personalized real human facial animation requires multiple mature animation staff, and in practice, the complex process and difficult technology may bring obstacles to inexperienced users. This paper proposes a new process to solve this kind of work, which has the advantages of low cost and less time than the traditional production method. For the personalized real human face model obtained by 3D reconstruction technology, first, use R3ds Wrap to topology the model, then use Avatary to make 52 Blend-Shape model files suitable for AR-Kit, and finally realize real-time markerless face capture 3D real human on the UE4 platform facial motion capture, this study makes rational use of the advantages of software and proposes a more efficient workflow for real-time markerless facial motion capture of personalized 3D real human models, The process ideas proposed in this paper can be helpful for other scholars who study this kind of work.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.218-227
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• 2020

Objective : To evaluate and compare the clinical and radiographic features of 25 patients with infectious spondylitis treated with anterior debridement and reconstruction using autogenous bone grafts vs. a metal cage with allogenic bone grafts. Methods : The study analyzed 25 patients diagnosed with infectious thoracolumbar spondylitis who underwent anterior radical debridement and reconstruction. Autogenous bone grafts were used in 13 patients (group 1), and a metal cage with allogenic bone grafts was used in 12 patients (group 2). Clinical outcomes were assessed by the visual analogue scale (VAS) scores and neurological status. Additionally, the serological results and the radiographic results using the sagittal Cobb angle were compared. Fusion was evaluated by computed tomography (CT) imaging at 24 months postoperatively. Results : Both groups showed a significant decrease in the postoperative mean VAS scores; however, only, group 1 patients showed a significantly higher VAS score than group 2 patients, 1 month postoperatively (p=0.002). The postoperative neurological status significantly improved. Elevated C-reactive protein levels and erythrocyte sedimentation rate values returned to normal limits at the 2-year follow-up without recurrent infection. No significant intergroup difference was observed in Cobb angle. Bony fusion was confirmed in all patients at CT 24 months postoperatively. Conclusion : Although the use of a metal cage with allogenic bone grafts for anterior column reconstruction remains controversial, our results suggest that it can be considered as an effective treatment of option for anterior column reconstruction in patients with infectious spondylitis.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.382-387
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• 2019

Background: Defects of the nasal ala and tip have a complex three-dimensional structure that makes them challenging to reconstruct. Many reconstructive options have been described for nasal ala and tip defects, ranging from primary closure to local flaps and skin grafts. However, it is difficult to determine which method will yield the best cosmetic results in each individual case. Thus, the purpose of this study was to determine which surgical procedures for reconstructing defects of the nasal ala and tip have better cosmetic results. Methods: From 2008 to 2018, 111 patients underwent surgery to reconstruct skin defects after resection of skin cancer in the nasal ala or tip. Their charts were reviewed to obtain data on age, sex, surgical location, size of the defect, surgical method, and cosmetic results using a visual analog scale (VAS). Results: For nasal ala reconstruction, the most commonly used surgical technique was the nasolabial flap (n= 42). This method also had the highest VAS score (7/10). The most commonly selected surgical method for nasal tip reconstruction was the bilobed flap (n= 13), and bilobed flaps and primary closure had the highest VAS score (7/10). Conclusion: Nasolabial flaps showed excellent cosmetic results for the reconstruction of nasal ala defects, while primary closure and bilobed flaps yielded excellent cosmetic results for the reconstruction of nasal tip defects.

• Journal of Acupuncture Research
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• v.34 no.1
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• pp.67-79
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• 2017

Objectives : The aim of this study was to report the effect of Korean medical therapy on pain and dysfunction after anterior cruciate ligament (ACL) reconstruction. Methods : A 25-year-old man experienced severe pain after right ACL reconstruction surgery. He received Korean medical treatments such as acupuncture, herbal medicine, and physiotherapy from July 10, 2014 to August 2, 2014. Results : After the treatments, his visual analogue scale scores generally decreased and the range of motion of the right knee improved from $0^{\circ}$ to $90^{\circ}$. Furthermore, the Knee Infury and Osteoarthritis Outcome Score increased from 99 to 142. Conclusion : The findings suggest that Korean medical treatments might be effectively used to treat pain and dysfunction after soft-tissue surgeries such as ACL reconstruction. Nevertheless, further research is warranted because of the limited sample size of this study.

• Journal of KIISE:Software and Applications
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• v.34 no.5
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• pp.476-486
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• 2007

This paper proposes a resolution enhancement method which can reconstruct high-resolution facial images from single-frame, low-resolution facial images. The proposed method is derived from example-based reconstruction methods and the morphable face model. In order to improve the performance of the example-based reconstruction, we propose the region-based reconstruction method which can maintain the characteristics of local facial regions. Also, in order to use the capability of the morphable face model to face resolution enhancement problems, we define the extended morphable face model in which an extended face is composed of a low-resolution face, its interpolated high-resolution face, and the high-resolution equivalent, and then an extended face is separated by an extended shape vector and an extended texture vector. The encouraging results show that the proposed methods can be used to improve the performance of face recognition systems, particularly to enhance the resolution of facial images captured from visual surveillance systems.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.47-52
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• 2010

Purpose: We report the clinical and radiographic result of ligament reconstruction using plantaris and total ankle replacement in end-stage ankle arthritis with ankle instability. Materials and Methods: The study is based on the 9 cases among total 48 patients of end-stage ankle arthritis that were treated with total ankle prosthesis and ligament reconstruction from 2007 to 2009 at least 12 months follow-up. We evaluated the VAS (Visual analogue scale) pain score, AOFAS (American orthopedic foot and ankle society) score and radiographic measurements. Results: Average age was 59.4 years (53~67 years) old. VAS pain score improved from preoperative average $8.2{\pm}0.9$ (range, 7~10) to $2.7{\pm}1.7$ (range, 0~6) and the AOFAS score improved from $46.4{\pm}14.6$ points (range, 23~69) to $80.1{\pm}9.3$ points (range, 65~95) at final follow-up. Anterior draw test improved $15.2{\pm}3.4$ mm (range, 12~23 mm) to $8.8{\pm}2.6$ mm (range, 6~13mm), varus stress test improved from $13.9{\pm}4.6^{\circ}$ (range, $10-18^{\circ}$) to $6.2{\pm}4.7^{\circ}$ (range, $2-18^{\circ}$) at final follow up. Conclusion: Plantaris ligament reconstruction is good option as part of the management of ankle instability with end-stage ankle arthritis. We achieved good clinical and radiographic results.

• Journal of Broadcast Engineering
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• v.8 no.1
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• pp.19-29
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• 2003

The demand for high-resolution images is gradually increasing, whereas many imaging systems yield aliased and undersampled images during image acquisition. In this paper, we propose a high-resolution image reconstruction algorithm considering inaccurate subpixel registration. A regularized Iterative reconstruction algorithm is adopted to overcome the ill-posedness problem resulting from inaccurate subpixel registration. In particular, we use multichannel image reconstruction algorithms suitable for application with multiframe environments. Since the registration error in each low-resolution has a different pattern, the regularization parameters are determined adaptively for each channel. We propose a methods for estimating the regularization parameter automatically. The preposed algorithm are robust against the registration error noise. and they do not require any prior information about the original image or the registration error process. Experimental results indicate that the proposed algorithms outperform conventional approaches in terms of both objective measurements and visual evaluation.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1393-1398
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• 2018

In conventional single-photon emission computed tomography (SPECT), only the photoelectric events in the detectors are used for image reconstruction. However, if the $^{131}I$ isotope, which emits high-energy radiations (364, 637, and 723 keV), is used in nuclear medicine, both photoelectric and Compton scattering events can be used for image reconstruction. The purpose of our work is to perform simulations for Compton SPECT by using the Geant4 application for tomographic emission (GATE). The performance of Compton SPECT is evaluated and compared with that of conventional SPECT. The Compton SPECT unit has an area of $12cm{\times}12cm$ with four gantry heads. Each head is composed of a 2-cm tungsten collimator and a $40{\times}40$ array of CdZnTe (CZT) crystals with a $3{\times}3mm^2$ area and a 6-mm thickness. Compton SPECT can use not only the photoelectric effect but also the Compton scattering effect for image reconstruction. The correct sequential order of the interactions used for image reconstruction is determined using the angular resolution measurement (ARM) method and the energies deposited in each detector. In all the results of simulations using spherical volume sources of various diameters, the reconstructed images of Compton SPECT show higher signal-to-noise ratios (SNRs) without degradation of the image resolution when compared to those of conventional SPECT because the effective count for image reconstruction is higher. For a Derenzo-like phantom, the reconstructed images for different modalities are compared by visual inspection and by using their projected histograms in the X-direction of the reconstructed images.