• The Journal of Advanced Prosthodontics
• /
• v.4 no.3
• /
• pp.153-157
• /
• 2012

PURPOSE. The study was conducted to compare the radiographic and clinical methods of measuring the horizontal condylar guidance (HCG) values. MATERIALS AND METHODS. The condylar guidance was measured using the radiographic (CT scan) and three clinical methods i.e. the wax protrusive records, Lucia jig record and intraoral central bearing device in 12 patients aged between 20-40 years irrespective of sex. The records were taken and transferred on the semi-adjustable articulator to record the HCG values. The CT scan was taken for 3D reconstruction of the mid facial region. Frankfort horizontal plane (FHP) and a line extending from the superior anterior most point on the glenoid fossa to the most convex point on the apex of articular eminence (AE) was marked on the CT scan. An angle between these two lines was measured on both right and left sides to obtain condylar inclination angle. Three interocclusal protrusive wax and jig records were taken and transferred to the semi adjustable articulator. Three readings were recorded on each side. Similarly the records were taken and transferred to the same articulator using the intra oral central bearing device to record the readings. RESULTS. The statistical analysis showed insignificant differences in the HCG values between the right and left sides [(P=.589 (CT), P=.928 (wax), P=.625 (jig), P=.886 (tracer)]. The clinical methods provided low Pearsons correlation values [(R = 0.423 (wax), R = 0.354 (jig), R = 0.265 (tracer)] for the right as well as the left sides when compared with the CT values. Among the clinical methods, jig and wax method showed strong level of association which is statistically significant while the intra-oral tracer showed weak association with the other two methods. CONCLUSION. The right and left HCG values were almost similar. The CT scan showed higher HCG values than the clinical methods and among the clinical methods, values obtained from all the methods were comparable.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.3 no.1
• /
• pp.27-35
• /
• 2016

Anterior knee pain is a major problem among adolescents and young adults especially those who participates in sports. The most common pathogenesis of anterior knee pain can arise from compression and shear forces in the patellofemoral joint. It is also caused by impingement of infrapatellar fat pad. Fat pad impingement can occur when the fat pad becomes swollen and inflamed due to a direct blow or chronic irritation. As a result, the bottom tip (or inferior pole) of the patella can pinch the fat pad. One of the many causes of swollen fat pad can be secondary to anterior cruciate ligament (ACL) injury. The aim of this study was to compare the infrapatellar fat pad volume in patients with acute ACL injury and a group of age-, gender-, and activity- matched controls with intact ligament. Axial magnetic resonance (MR) images have been performed on 32 patients with torn ACL and 40 control patients. The volume of the fat pad was measured digitally from MR image by using a 3d Reconstruction software, ellipsoidal approximation, and a MATLAB code. The results were compared between patients with torn ACL and control group. Patients with a torn ACL had a significantly larger fat pad than the controls (P=0.01). There was no significant difference between the methods used to measure the infrapatellar fat pad volume (P=0.83-0.87). Thus, lesions of the infrapatellar fat pad is often associated with ACL injury.

• Nuclear Engineering and Technology
• /
• v.56 no.3
• /
• pp.1066-1080
• /
• 2024

SMART100 has a containment pressure and radioactivity suppression system (CPRSS) for passive containment cooling system (PCCS). This prevents overheating and over-pressurization of a containment through direct contact condensation in an in-containment refueling water storage tank (IRWST) and wall condensation in a CPRSS heat exchanger (CHX) in an emergency cool-down tank (ECT). The Korea Atomic Energy Research Institute (KAERI) constructed scaled-down test facilities, SISTA1 and SISTA2, for the thermal-hydraulic validation of the SMART100 CPRSS. Three separate effect tests were performed using SISTA1 to confirm the heat removal characteristics of SMART100 CPRSS. When the low mass flux steam with or without non-condensable gas is released into an IRWST, the conditions for mitigation of the chugging phenomenon were identified, and the physical variables were quantified by the 3D reconstruction method. The local behavior of the non-condensable gas was measured after condensation inside heat exchanger using a traverse system. Stratification of non-condensable gas occurred in large tank of the natural circulation loop. SISTA2 was used to simulate a small break loss-of-coolant accident (SBLCOA) transient. Since the test apparatus was a metal tank, compensations of initial heat transfer to the material and effect of heat loss during long-term operation were important for simulating cooling performance of SMART100 CPRSS. The pressure of SMART100 CPRSS was maintained below the design limit for 3 days even under sufficiently conservative conditions of an SBLOCA transient.

• Journal of Chest Surgery
• /
• v.29 no.3
• /
• pp.278-284
• /
• 1996

Nine infants with transposition of great arteries have undergone arterial switch operation from May 1989 to May 1994 in the Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. Patients' age ranged from 3 days to 90 days, averaging 30$\pm$21 days. Diagnosis was made by two-dimensional echocardiography in all patients. Eight patients were diagnosed as transposition of great arteries with ventricular septal defect and one patient was a simple transposition of great arteries. Associated anomalies were patent ductus arteriosus (8), atrial septal defect (7) and coarctation of aorta(1). The anatomy of the coronary arteries were 7 (77 %) type A and 2 (23 %) type D according to the Yacoub classification. Pulmonary artery reconstruction was done according to Lecompte maneuver with tautologous pericardial patch in 8 patients. Overall operative mortality rate was 55% Left heart failure and pulmonary hypertensive crisis were the cause of death on postoperative 1~2 days in three patients, and two succumbed to death due to sepsis on postoperative 2~ 3 weeks. The mean follow-up period was mean 17 months. No patient had clinically significant postoperative aortic regurgitation and supravalvular pulmonary stenosis. The excessive use of inotropic support postoperatively was identified as a stastically significant risk factor following the arterial switch operation. But other variables such as low body weight, long cardiopulmonary bypass time, excessive hemodilution during cardiopulmonary bypass, hypothermia and volume loading were not significant risk factors.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.6
• /
• pp.614-627
• /
• 2018

Urban railway lines have been constructed adjacent to residential buildings and urban areas. The expansion of transportation networks and reconstruction of residential buildings in highly populated urban areas require deep excavations in areas adjacent to urban railways. Mobilized soil stresses and changes in the groundwater level induced by deep excavations results in track irregularities in urban railways. In this study, a three-dimensional finite difference model using the commercial program FLAC3D was adopted to estimate the horizontal displacements of earth retaining structures, settlements of backfill, the stability of track irregularity and underground box structure based on the criteria of each railway organization and its relationships. In deep excavations, a change in groundwater level induces relatively very small differences for track gauge irregularities, whereas relatively large differences for longitudinal irregularities of 72.5%, twist irregularities of 83.3%, cross level irregularities of 61.9%, and alignments of 43.3% were found to be the maximum differences when the horizontal displacement of earth retaining wall and settlement of backfill were 65.1% and 21.4%, respectively, because the groundwater level (GWL) on the ground surface-mobilized tensile strength of the underground box structure exceeds the allowable value. Therefore, three-dimensional numerical analysis was performed in this study. Overall, real-time monitoring should be carried out to prevent railway accidents in advance when a deep excavation adjacent to urban railway structures is constructed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.33 no.1
• /
• pp.31-43
• /
• 2015

This study had been aimed to conduct the camera calibration on VLBI antenna in the Space Geodetic Observation Center of Sejong City with a low-cost digital camera, which embedded in a mobile phone to determine the three-dimension position coordinates of the VLBI antenna, based on stereo images. The initial values for the camera calibration have been obtained by utilizing the Direct Linear Transformation algorithm and the commercial digital photogrammetry system, PhotoModeler $Scanner^{(R)}$ ver. 6.0, respectively. The accuracy of camera calibration results was compared with that the camera calibration results, acquired by a bundle adjustment with nonlinear collinearity condition equation. Although two methods showed significant differences in the initial value, the final calibration demonstrated the consistent results whichever methods had been performed for obtaining the initial value. Furthermore, those three-dimensional coordinates of feature points of the VLBI antenna were respectively calculated using the camera calibration by the two methods to be compared with the reference coordinates obtained from a total station. In fact, both methods have resulted out a same standard deviation of $X=0.004{\pm}0.010m$, $Y=0.001{\pm}0.015m$, $Z=0.009{\pm}0.017m$, that of showing a high degree of accuracy in centimeters. From the result, we can conclude that a mobile phone camera opens up the way for a variety of image processing studies, such as 3D reconstruction from images captured.

• Restorative Dentistry and Endodontics
• /
• v.36 no.2
• /
• pp.98-107
• /
• 2011

Caries remains prevalent throughout modern society and is the main disease in the field of dentistry. Although studies of this disease have used diverse methodology, recently, X-ray microtomography has gained popularity as a non-destructive, 3-dimensional (3D) analytical technique, and has several advantages over the conventional methods. According to X-ray source, it is classified as monochromatic or polychromatic with the latter being more widely used due to the high cost of the monochromatic source despite some advantages. The determination of mineral density profiles based on changes in X-ray attenuation is the principle of this method and calibration and image processing procedures are needed for the better image and reproducible measurements. Using this tool, 3D reconstruction is also possible and it enables to visualize the internal structures of dental caries. With the advances in the computer technology, more diverse applications are being studied, such automated caries assessment algorithms.

• Journal of the Korean Arthroscopy Society
• /
• v.7 no.2
• /
• pp.183-188
• /
• 2003

Purpose : The purpose of this study is to evaluate the results of revision surgery for failed anterior cruciate ligament (ACL) reconstruction using quadruple hamstring tendon autograft. Materials and Methods : From May 2000 to July 2002, six patients received ACL revision surgery using quadruple hamstring autograft for failed ACL reconstruction. Femoral tunnels were made 40 mm in depth and fixed with a cross pin and a bioabsorbable interference screw to fill the bone defect. In tibial tunnels, the grafts were fixed with Intrafix(Mitek, Norwood, MA). In case of tibial tunnel widening, additional screw-washer fixation was done. Follow up was at least 12 months postoperatively. Clinical assessments consisted of Lysholm knee scores, International Knee Documentation Committee(IKDC) evaluation form and manual maximal side to side difference using KT-2000 arthrometer. Results : The average Lysholm knee score improved from 77.2 preoperatively to 87.7 postoperatively. At the final IKDC evaluation, 1 case was graded as normal, 4 nearly normal, 1 abnormal. Mean side to side difference of manual maximum anterior displacement using the KT-2000 arthrometer was 1.8mm. The success rate was $83\%$. Conclusion : ACL revision surgery using quadruple hamstring autograft with double fixation is considered good procedure with successful results.

• Journal of Gastric Cancer
• /
• v.15 no.2
• /
• pp.105-112
• /
• 2015

Purpose: Intracorporeal anastomosis is the most difficult procedure during pure single-incision distal gastrectomy (SIDG) that affects its generalization. We introduced unaided delta-shaped anastomosis (uDelta), a novel anastomosis technique, for gastroduodenostomy after pure SIDG, and compared the results with those of previously reported Roux-en-Y anastomosis (RY). Materials and Methods: Between March 2014 and March 2015, SIDG with D1+ lymph node dissection was performed for early gastric cancer through a 2.5-cm transumbilical incision without any additional port. uDelta was performed by the operator alone, without any intracorporeal assistance. Results: uDelta was performed on 11 patents, and uncut RY was performed on 5-patients without open or multiport conversion. R0 resection was performed in all cases. No significant differences were observed in mean age and body mass index between patients who underwent uDelta or RY. Mean operation times were $214.5{\pm}36.2$ minutes for uDelta and $240.8{\pm}65.9$ minutes for RY, which was not significantly different. Reconstruction time for uDelta was shorter than that for RY, with marginal statistical significance ($26.1{\pm}8.3$ minutes vs. $38.0{\pm}9.1$ minutes, P=0.05). There were no intraoperative transfusions, 30-day mortality, or anastomosis-related complications in either group. Average length of hospital stay was $8.2{\pm}1.9$ days in the uDelta group and $7.2{\pm}0.8$ days in the RY group (P=0.320). Conclusions: After carefully considering indications, uDelta can be a feasible and can be a reproducible reconstruction method after SIDG in early gastric cancer.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.3
• /
• pp.23-31
• /
• 2010

The increasing demands on low-power, and low-complexity video encoder have been motivating extensive research activities on distributed video coding (DVC) in which the encoder compresses frames without utilizing inter-frame statistical correlation. In DVC encoder, contrary to the conventional video encoder, an error control code compresses the video frames by representing the frames in the form of syndrome bits. In the meantime, the DVC decoder generates side information which is modeled as a noisy version of the original video frames, and a decoder of the error-control code corrects the errors in the side information with the syndrome bits. The noisy observation, i.e., the side information can be understood as the output of a virtual channel corresponding to the orignal video frames, and the conditional probability of the virtual channel model is assumed to follow a Laplacian distribution. Thus, performance improvement of DVC systems depends on performances of the error-control code and the optimal reconstruction step in the DVC decoder. In turn, the performances of two constituent blocks are directly related to a better estimation of the parameter of the correlation channel. In this paper, we propose an algorithm to estimate the parameter of the correlation channel and also a low-complexity version of the proposed algorithm. In particular, the proposed algorithm minimizes squared-error of the Laplacian probability distribution and the empirical observations. Finally, we show that the conventional algorithm can be improved by adopting a confidential window. The proposed algorithm results in PSNR gain up to 1.8 dB and 1.1 dB on Mother and Foreman video sequences, respectively.