• Journal of Korea Multimedia Society
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• v.10 no.2
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• pp.179-186
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• 2007

This paper proposes a novel method for face detection method using Zernike moments. To detect the faces in an image, local regions in multiscale sliding windows are classified into face and non-face by a neural network, and input features of the neural network consist of Zernike moments. Feature dimension is reduced as the reconstruction capability of orthogonal moment. In addition, because the magnitude of Zernike moment is invariant to rotation, a tilted human face can be detected. Even so the detection rate of the proposed method about head on face is less than experiments using intensity features, the result of our method about rotated faces is more robust. If the additional compensation and features are utilized, the proposed scheme may be best suited for the later stage of classification.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.159-164
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• 2001

Reduction cranioplasty is one of the treatment modality among many treatment options for macrocephaly with hydrocephalus. The most previous techniques of reduction cranioplasty have some disadvantages such as difficult airway maintenance, pressure sore due to modified prone position, severe venous infarct due to obstruction of venous blood flow and large amount of bleeding from the dissection of superior sagittal sinus to obtain bone fragment needed. A 28-month-old girl had extreme macrocephaly. She couldn't control head rotation and keep sitting position. The operation was performed at supine position with adequate exposure of entire calvarium and the hinge was made in occipital bone fragment that covered posterior part of superior sagittal sinus. Bleeding volume and the other complications were decreased and acceptable reduction was achieved with this method.

• Steel and Composite Structures
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• v.32 no.6
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• pp.769-778
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• 2019

The specially prefabricated steel moment connections with pyramid head is one of the significant innovations in the steel structures forms to improve the installation time and simplify the construction procedure. The beams in this structure form are supported by two top and bottom angles and web double angles. Such a configuration despite its advantages increases the welding operation and filed installation time and costs. In this paper, the effect of using beams with channel and I section in three classes of seismically compact, seismically non-compact, and slender section according to width-to-thickness ratio on the behavior of the connection was investigated under monotonic and cyclic loading. Modeling was performed by ABAQUS and verified by the results of an experimental specimen. The findings indicated that using I and channel section instead of angle section reduces the amount of welding materials as well as easing the installation procedure. However, it has no significant effect on the ultimate strength and ductility of the connection. Furthermore, if the beam section is seismically compact, this form is considered as a special moment frame that has a rotation capacity up to 0.04 radians without any reduction in connection moment resistance.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.137-146
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• 2008

The purpose of this study is to examine the causes of errors from EGR posture on the balance beam, which is bending flick-flack salto backward stretched national team players through kinematic analysis, and present training methods for them so as to provide scientifically useful information to coaches and athlete. Findings from this study are summarized below. The most important factors that affect the errors in boyd center position and speed change were the speed change of left and right body centers and the horizontal and vertical speed changes. The left and right acceleration changes were greater in failed posture than in successful posture. The horizontal and vertical accelerations in E3 and E5 were the key factors that affected the backward somersault and landing. The angular speed changes which varied between success and failure were notable in head and shoulder joints. In individual results. The section when the angular speeds of head and shoulder joint must be the greatest was E4. In this section, when the body is extending instantly in a bent posture, increasing the angular speeds of head, shoulder and hip joints can improve the duration of staying in the air and the rotation radius of a somersault.

• Fire Science and Engineering
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• v.33 no.3
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• pp.56-62
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• 2019

This study examined effects of the operating characteristics of a pump according to the rotational speed of a pump and the change in flow rate when a centrifugal pump operates under the following conditions: regulated flow rate, head, rotational speed, and specific speed of 0.7 m/min, 8 m, 1750 rpm, an 182 (m, ㎥/min, rpm), respectively. The pump in the experiment did not have a guide vane and was connected directly to the rim, so that the rotational speed of the volute pump in a spiral or volute casing increased by 100 rpm from 1350 to 1750 rpm. The result of the relationship between the H-Q, L-Q, and 𝜂-Q characteristics and the dimensionless performance characteristics, such as the head coefficient, power coefficient and efficiency were studied. The change in pump performance could be estimated depending on the increase in the number of revolutions. The maximum efficiency of the pump was 52% with 1450 rpm, 0.165 ㎥/min flux, and 4.73 m of lift. The efficiency reached 50% with a maximum of 1750 rpm, 0.183 ㎥/min of flux, and 6.72 m of lift. The efficiency curve on the performance characteristics of the lift versus flux curve became oval not a curve from a quadratic equation that passes through the starting point according to the similarity law of the pump. Finally, when the flux coefficient increased, the power coefficient increased and the lift coefficient decreased. When the flux coefficient was 0.08, the maximum efficiency was 52%. Therefore, the change in flux affects the driving characteristics.

• Physical Therapy Korea
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• v.11 no.2
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• pp.35-45
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• 2004

The purpose of this study was to investigate the correlation and characteristics between electromyographic (EMG) activities of lower leg muscles and the posturographic assessment of static balance control in normal adults. Twenty-four young, healthy adults(12 males, 12 females) participated in the study. Center of pressure (COP) parameters were obtained using force platform as total path distance, total sway area, X mean frequency and Y mean frequency for 20 seconds in the following conditions: (1) comfortable standing with eyes opened or closed, (2) uncomfortable standing (feet together) with eyes opened or closed, (3) virtual moving surround delivered using Head mount display (HMD) with four different moving patterns. The virtual moving patterns consisted of close-far, superior-inferior tilting (pitch), right-left tilting (roll), and horizontal rotation (yaw) movements. Surface electromyographic activites were recorded on the tibialis anterior, peroneus longus, medial and lateral heads of gastrocnemius muscles under each condition. Correlation between the posturographic measures and EMG activities were evaluated. Total path distance and total sway area of COP were significantly increased during uncomfortable standing. EMG activity of tibialis anterior was significantly more during uncomfortable standing and virtual moving surround stimulation than during comfortable standing. Total path distance and sway area of COP during comfortable standing with closed eyes showed significant positive correlation with the EMG activities of the lateral head of gastrocnemius muscle. Total path distances and total sway area of COP during muscle. Total path distances and total sway area of COP during presentation of virtual moving surround also had significant positive correlations with EMG activities of the lateral head of gastrocnemius muscle under close-far movement.

• Journal of the Korean Geotechnical Society
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• v.38 no.7
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• pp.5-24
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• 2022

The current performance evaluation of slope anchors qualitatively determines the physical bonding between the anchor head and ground as well as cracks or breakage of the anchor head. However, such performance evaluation does not measure these primary factors quantitatively. Therefore, the time-dependent management of the anchors is almost impossible. This study is an evaluation of the 3D numerical model by SfM which combines UAS images with terrestrial LiDAR to collect numerical data on the damage factors. It also utilizes the data for the quantitative maintenance of the anchor system once it is installed on slopes. The UAS 3D model, which often shows relatively low precision in the z-coordinate for vertical objects such as slopes, is combined with terrestrial LiDAR scan data to improve the accuracy of the z-coordinate measurement. After validating the system, a field test is conducted with ten anchors installed on a slope with arbitrarily damaged heads. The damages (such as cracks, breakages, and rotational displacements) are detected and numerically evaluated through the orthogonal projection of the measurement system. The results show that the introduced system at the resolution of 8K can detect cracks less than 0.3 mm in any aperture with an error range of 0.05 mm. Also, the system can successfully detect the volume of the damaged part, showing that the maximum damage area of the anchor head was within 3% of the original design guideline. Originally, the ground adhesion to the anchor head, where the z-coordinate is highly relevant, was almost impossible to measure with the UAS 3D numerical model alone because of its blind spots. However, by applying the combined system, elevation differences between the anchor bottom and the irregular ground surface was identified so that the average value at 20 various locations was calculated for the ground adhesion. Additionally, rotation angle and displacement of the anchor head less than 1" were detected. From the observations, the validity of the 3D numerical model can obtain quantitative data on anchor damage. Such data collection can potentially create a database that could be used as a fundamental resource for quantitative anchor damage evaluation in the future.

• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.154-158
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• 2000

Purpose : The purpose of this study is to demonstrate changes in the orientation ortho glenohumeral ligaments(GHL) in different degrees of abduction and rotation of the normal healthy individuals. Materials and Methods : Saline Magnetic Resonance(MR) arthrography of nine consecutive shoulders of normal healthy adults were checked. At that time, MR images were obtained in three different positions of abduction and external rotation($0^{\circ}C\;and\;0^{\circ},\;45^{\circ}C\;and\;25^{\circ}C,\;90^{\circ}$ and maximum, respectively). From a series of consecutive MRI, three-dimensional images were reconstructed after detecting the location of the middle glenohumeral ligament(MGHL) and the inferior glenohumeral ligament(IGHL) using workstation computer. Results : The shape of the MGHL was taken in double curved, and straight, and finally curved again in three different positions of the shoulder in sequence. On the other hand, the shape of the IGHL was obliquely positioned, and curvilinear, and finally straight and extended at lower part of the anterior surface of the humeral head. Conclusions : At $45^{\circ}$ of abduction and $25^{\circ}$ of external rotation, and at $90^{\circ}$ of abduction and maximal external rotation of the shoulder, the MGHL and the IGHL had the role of the most important static stabilizer of the glenohumeral joint repectively.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.97-105
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• 2018

Purpose : Proton Therapy using Bragg-peak, because it has distinct characteristics in providing maximum dosage for tumor and minimal dosage for normal tissue, a medical imaging system that can quantify changes in patient position or treatment area is of paramount importance to the treatment of protons. The purpose of this research is to evaluate the usefulness of the algorithm by comparing the image matching through the set-up and in-house code through the existing dips program by producing a Matlab-based in-house registration code to determine the error value between dips and DRR to evaluate the accuracy of the existing treatment. Materials and Methods : Thirteen patients with brain tumors and head and neck cancer who received proton therapy were included in this study and used the DIPS Program System (Version 2.4.3, IBA, Belgium) for image comparison and the Eclipse Proton Planning System (Version 13.7, Varian, USA) for patient treatment planning. For Validation of the Registration method, a test image was artificially rotated and moved to match the existing image, and the initial set up image of DIPS program of existing set up process was image-matched with plan DRR, and the error value was obtained, and the usefulness of the algorithm was evaluated. Results : When the test image was moved 0.5, 1, and 10 cm in the left and right directions, the average error was 0.018 cm. When the test image was rotated counterclockwise by 1 and $10^{\circ}$, the error was $0.0011^{\circ}$. When the initial images of four patients were imaged, the mean error was 0.056, 0.044, and 0.053 cm in the order of x, y, and z, and 0.190 and $0.206^{\circ}$ in the order of rotation and pitch. When the final images of 13 patients were imaged, the mean differences were 0.062, 0.085, and 0.074 cm in the order of x, y, and z, and 0.120 cm as the vector value. Rotation and pitch were 0.171 and $0.174^{\circ}$, respectively. Conclusion : The Matlab-based In-house Registration code produced through this study showed accurate Image matching based on Intensity as well as the simple image as well as anatomical structure. Also, the Set-up error through the DIPS program of the existing treatment method showed a very slight difference, confirming the accuracy of the proton therapy. Future development of additional programs and future Intensity-based Matlab In-house code research will be necessary for future clinical applications.

• Progress in Medical Physics
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• v.14 no.3
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• pp.189-195
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• 2003

The comparative analysis of a portal image and a simulation image is a very important process in radiotherapy for verifying the accuracy of an actual treatment field. In this study, we applied a chamfer-matching algorithm to compare a portal image with a simulation image and verified the accuracy of the algorithm to analyze the field matching error in the portal image. We also developed an analysis program that could analyze the two images more effectively with a chamfer-matching method and demonstrated its efficacy through a feasibility study. With virtual portal images, the accuracy of the analysis algorithm were acceptable considering the average error of shift (0.64 mm), rotation (0.32$^{\circ}$), and scale (1.61%). When the portal images of a head and neck phantom were analyzed, the accuracy and suitability of the developed analysis program was proven considering the acceptable average error of shift (1.55 mm), rotation (0.80$^{\circ}$), and scale (1.72%). We verified the applicability of a chamfer-matching algorithm to the comparative analysis of a portal image with a simulation image. The analysis program developed in this study was a practical tool to calculate the quantitative error of the treatment field in a portal image.