• Journal of Korea Multimedia Society
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• v.15 no.11
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• pp.1341-1348
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• 2012

In this paper, an efficient scheme for correcting rotated objects in medical images using the Mojette transform is presented. The Mojette transform is a kind of discrete Radon transform, where the transform domain is represented by a set of projections. The Mojette transform currently studied in the image compression area is modified for detecting the rotation angle of objects in medical images. First, in order to find accurate rotation angle, the projection value in the Mojette transform is determined by using pixels on the projection line and in addition the linear interpolation of pixels adjacent to the line. Second, at each projection angle, only one projection is implemented for reducing the amount of the calculation in the process of the Mojette transform. Finally, the projection in the Mojette transform is carried out at the predetermined ROI(Region Of Interest) at which the objects are not cropped or added by rotating the image. The simulation results show that the proposed method has good performance for correcting the rotation angle in medical images.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.642-648
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• 2009

Purpose: Hexadactyly without thumb is a rare congenital anomaly of the hand where six triphalangeal digits are symmetrically distributed without thumb. Contrary to mirror hands, triphalangeal six digits are symmetrically distributed on each side at the midline with well - differentiated carpal bones, extensor tendons, one ulnar and one radius. The authors developed a new surgical technique based on a three - dimensional concept to correct the hexadactyly and applied to 2 cases of hexadactyly with good functional and aesthetic results. Here we document the surgical technique and its result. Methods: A 16 month old male patient visited our clinic with chief complaints of bilateral hexadactyly deformity. On physical examination most radial first and second digits showed no opposition and adduction motion on both side hands. Radiography showed 6 triphalangeal digits with normal development of carpal, radial and ulnar bone. Right side abnormality was corrected by removal of most radial side extra - digit, rotation and migration of 2nd ray to thumb position and creation of 1st web by transposing a mid - palm based rectangular palmar flap as in Snow & Littler procedure which has been being applied for correction of 1st web syndactyly in cleft hand deformity. Seven months later, left side abnormality was also corrected with the same procedure. Results: Postoperative appearances of the both hands were satisfactory. Flexion, extension, opposition and grasping were possible with the pollicized 2nd ray. Pinching power was 3.0 kg 15 months after surgery and 2.5 kg 22 months after in right hand respectively. Conclusion: In correction of hexadactyly deformity, satisfactory aesthetic and relevant functional results can be expected with authors' newly developed technique: removal of most radial digit, rotation and migration of 2nd digit to thumb position as well as creation of the 1st web space by transposition of mid - palm based rectangular flap.

• The korean journal of orthodontics
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• v.54 no.5
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• pp.316-324
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• 2024

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young's modulus and Poisson's coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions: DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

• Current Optics and Photonics
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• v.4 no.6
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• pp.500-508
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• 2020

The rifling angle of artillery is an important parameter, and its determination plays a key role in the stability, hit rate, accuracy and service life of artillery. In this study, we propose an optical measurement method for the rifling angle based on angle error correction. The method is based on the principle of geometrical optics imaging, where the rifling on the inner wall of the artillery barrel is imaged on a CCD camera target surface by an optical system. When the measurement system moves in the barrel, the rifling image rotates accordingly. According to the relationship between the rotation angle of the rifling image and the travel distance of the measurement system, different types of rifling equations are established. Solving equations of the rifling angle are deduced according to the definition of the rifling angle. Furthermore, we added an angle error correction function to the method that is based on the theory of dynamic optics. This function can measure and correct the angle error caused by the posture change of the measurement system. Thus, the rifling angle measurement accuracy is effectively improved. Finally, we simulated and analyzed the influence of parameter changes of the measurement system on rifling angle measurement accuracy. The simulation results show that the rifling angle measurement method has high measurement accuracy, and the method can be applied to different types of rifling angle measurements. The method provides the theoretical basis for the development of a high-precision rifling measurement system in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2367-2372
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• 2015

One of various low-density parity-check(LDPC) codes that has been adopted in many communication standards due to its error correction ability is a quasi-cyclic LDPC(QC-LDPC) code, which leads to comparable decoder complexity. One of the main blocks in the QC-LCDC code decoder is a multi-size circular shifter(MSCS) that can perform various size rotation. The MSCS can be implemented with many structures, one of which is based on Banes network. The Benes network structure can perform the normal MSCS operation efficiently, but it cannot use the properties coming from specifications like rotation sizes. This paper proposesd a scheme where the Benes network structure can use the rotation size property with the modification of the control signal generation. The proposed scheme is applied to the MSCS of IEEE 802.16e WiMAX QC-LDPC decoder to reduce the number of MUXes and the critical path delay.

• The Journal of Korean Society for Radiation Therapy
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• v.28 no.2
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• pp.109-121
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• 2016

To verify the accuracy of the image guided radiotherapy using ExacTrac 6D couch, the error values in six directions are randomly assigned and corrected and then the corrected values were compared with CBCT image to check the accurateness of ExacTrac. The therapy coordination values in the Rando head Phantom were moved in the directions of X, Y and Z as the translation group and they were moved in the directions of pitch, roll and yaw as the rotation group. The corrected values were moved in 6 directions with the combined and mutual reactions. The Z corrected value ranges from 1mm to 23mm. In the analysis of errors between CBCT image of the phantom which is corrected with therapy coordinate and 3D/3D matching error value, the rotation group showed higher error value than the translation group. In the distribution of dose for the error value of the therapy coordinate corrected with CBCT, the restricted value of dosage for the normal organs in two groups meet the prescription dose. In terms of PHI and PCI values which are the dose homogeneity of the cancerous tissue, the rotation group showed a little higher in the low dose distribution range. This study is designed to verify the accuracy of ExacTrac 6D couch using CBCT. It showed that in terms of the error value in the simple movement, it showed the comparatively accurate correction capability but in the movement when the angle is put in the couch, it showed the inaccurate correction values. So, if the body of the patient is likely to have a lot of changes in the direction of rotation or there is a lot of errors in the pitch, roll and yaw in ExacTrac correction, it is better to conduct the CBCT guided image to correct the therapy coordinate in order to minimize any side effects.

• Radiation Oncology Journal
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• v.21 no.2
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• pp.174-181
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• 2003

Purpose: The target volume for the three field technique in breast cancer include the breast tangential and supraclavicular areas. The techniques rotating the gantry and couch angles, to match these two areas, will geometrically produce mismatching of the posterior edge between the medial and lateral tangential beams. This mismatch was confirmed by film dosimetry and three-dimensional computer planning. The correction methods of this mismatching were studied in this article. Materials and Methods: After the supraclavicular field was simulated using a half beam block and the medial and lateral tangential fields, by the rotation of the couch and gantry, we compared the following two methods to correct the mismatch. The first method was the rotation of coillmator until a line drawn on the posterior edge of tangential beams before the rotation of couch aligned the line drawn on the posterior edge after the rotation. The second method was the rotation of collimator according to the formula developed by the author as follows; Co=$2sin^{-1}${$sin\{theta}\{cdot}sin(C/2)$} (Co: collimator angle, $\theta$: angle between tangential beam and table, C: couch angle) Results: The film dosimetry showed the mismatching of posterior edges of the medial and lateral tangential fields prior to the rotation of collimator, while the posterior edges matched well after the rotation of collimator according to the formula. The three-dimensional computer plan also showed that the posterior edges matched well after the rotation of collimator accordingly. The DVH of the ipsilateral lung with the proper rotation of collimator angle was better than that without the rotation of collimator angle. Conclusion: The mismatching of the posterior edges of the medial and lateral tangential fields can be recognized on the three fileld technique in breast irradiation when the gantry and couch are simultaneously rotated and can be corrected with the proper rotation of the collimator angle. The radiation dose to the ipsilateral lung could be lowered with this technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5C
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• pp.364-370
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• 2005

The first step of face recognition is to align an input face picture with database images. We propose a new algorithm of removing registration error in eigenspace. Our algorithm can correct for translation, rotation and scale changes. Linear matrix modeling of registration error enables us to compensate for subpixel errors in eigenspace. After calculating derivative of a weighting vector in eigenspace we can obtain the amount of translation or rotation without time consuming search. We verify that the correction enhances the recognition rate dramatically.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.192-200
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• 2018

In this study, improvements for error correction, speed, position, and rotation calculation algorithms have been proposed to be used in resolver to digital conversion (RDC) systems. The proposed open-loop system drives the resolver and uses the output signals of the resolver signal to estimate the real time position, the instant speed, and the rotation count with high resolution and accuracy even at high speeds and noise. The proposed solution implements strong features of both closed and open loop based systems while eliminating their weak points. The improvements proposed is resistant to noise owing to digital FIR filter and data averaging techniques. The implementation used for proof of concept is implemented on a hardware using an FPGA and configurable to be used by any resolver.

• Journal of Gastric Cancer
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• v.20 no.4
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• pp.454-460
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• 2020

Tracheo-gastric conduit fistula is an extremely rare but severe complication that is difficult to manage. Conservative care, esophageal or tracheal stent placement, or cutaneomuscular flaps have been suggested; however, no definite treatment has been proven. We report a case of tracheo-gastric conduit fistula that occurred after a minimally invasive radical three-field esophagectomy. Following the primary surgery, the diagnosis was made while evaluating the patient's frequent aspiration and coughing. Conservative management failed, and a surgical correction was undertaken to identify the multifocal mucosal defect and exposed tracheal ring. A sternocleidomastoid muscle rotation flap and subsequent Histoacryl injection into the remaining fistula were performed, and the fistula was successfully managed.