• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.6
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• pp.333-343
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• 2018

In this paper, we study the existing results of the structure-soil-structure interaction (SSSI) effect on seismic responses of structures and summarize important parameters. The parameters considered in this study are a combination of buildings in the power block of a nuclear power plant, the characteristics of earthquake ground motions and its direction, and the characteristics embedded under the ground. Based on these parameters, the seismic analysis model of the structures in the power block of the nuclear power plant is developed and the structure-soil-structure interaction analyses are performed to analyze the influence of the parameters on the seismic response. For all analyses, the soil-structure interaction (SSI) analysis program CNU-KIESSI, which was developed to enable large-sized seismic analysis, is used. In addition, the SSI analyses is performed on individual structures and the results are compared with the SSSI analysis results. Finally, the influence of the parameters on the seismic response of the structure due to the SSSI effect is reviewed through comparison of the analysis results.

• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.287-293
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• 2017

PURPOSE. To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS. A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (${\pm}SD$). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS. Dimensional changes compared to reference values varied between -74.01 and $32.57{\mu}m$ (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION. The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.

• The Research Journal of the Costume Culture
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• v.25 no.3
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• pp.270-284
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• 2017

This study aimed to create 3D-printed insoles for flat-footed senior men using 3D systems. 3D systems are product-manufacturing systems that use 3-dimensional technologies like 3D scanning, 3D modeling, and 3D printing. This study used a 3D scanner (NexScan2), 3D CAD programs including Rapidform, AutoCAD, SolidWorks, Nauta+ compiling program, and a 3D printer. In order to create insoles for flat-footed senior men, we analyzed horizontal sections of 3D foot scans We selected 20 flat-footed and 20 normal-footed subjects. To make the 3D insole models, we sliced nine lines on the surface of the subjects' 3D foot scans, and plotted 144 points on the lines. We calculated the average of these 3D coordinates, then located this average within the 3D space of the AutoCAD program and created 3D sole models using the loft surface tools of the SolidWorks program. The sole models for flat feet differed from those of normal feet in the depth of the arch at the inner sideline and the big toe line. We placed the normal-footed sole model on a flat-footed sole model, and the combination of the two models resulted in the 3D insole for flat feet. We printed the 3D modeled insole using a 3D printer. The 3D printing material was an acrylic resin similar to rubber. This made the insole model flexible and wearable. This study utilized 3D systems to create 3D insoles for flat-footed seniors and this process can be applied to manufacture other items in the fashion industry as well.

• Journal of Veterinary Clinics
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• v.35 no.3
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• pp.114-118
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• 2018

A 3-month-old intact male Lakeland terrier was presented with recurring regurgitation after removing cervical esophageal foreign body by endoscopy. Blood and urine analysis, radiography, ultrasonography, fluoroscopic esophagography, computed tomographic angiography (CTA) were performed. In radiography and fluoroscopic esophagography, vascular ring anomaly was considered as the primary cause of megaesophagus, and CTA with gas-inflation of the esophagus was performed. Compressed esophagus, persistent right aortic arch (PRAA), aberrant left subclavian artery (LSA), and a venous structure which was confirmed in surgery to be incomplete type persistent left cranial vena cava (PLCVC) connected with the left side azygos vein were observed. Left deviation of the trachea was also revealed in CT, which implies the compression by left ligamentum arteriosum. Therefore, type 3 PRAA with left ligamentum arteriosum and aberrant LSA, was considered as a prior differential diagnosis. Surgical repair was performed and the clinical signs improved. This report describes CTA characteristics of combination of PRAA with aberrant LSA, incomplete PLCVC and Lt. azygos vein in a dog. Although not every vascular anomaly does induce clinical sign, some types can complicate the surgical procedure, and cause clinical signs. Therefore, thorough evaluation of vascular anomalies in the thorax is important, and CTA is a useful method in identifying multiple vascular anomalies in dogs.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.311-316
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• 2006

A scissors bite in the posterior teeth occurs when the upper teeth are positioned totally or unilaterally buccal to the lower teeth in centric occlusion. This malocclusion can result from either excessive width of maxilla, deficient width mandible, or combination of both. The malocclusion can lead to hindered growth of jaws or to asymmetry between the jaws, Besides, the severe lingual inclination of the mandibular posterior teeth prevents adequate mastication. Thus, the scissors bite is in need of immediate interceptive orthodontic intervention. The common treatments of the scissors bite is to expand the mandibular arch: fixed or removable appliances. In our clinic, we made a success in treatment of the scissors bite using the Schwarz appliance. We treated the scissors bite using the lower Schwarz appliance for a mean observation period of 21 months. The subjects were 2 boys, aged 4 years.

• Computers and Concrete
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• v.15 no.1
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• pp.103-126
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• 2015

Thermal effects are significant loads for assessing concrete dam behaviour during operation. A new methodology to estimate thermal loads on concrete dams taking into account processes which were previously unconsidered, such as: the evaporative cooling, the night radiating cooling or the shades, has been recently reported. The application of this novel approach in combination with a three-dimensional finite element method to solve the heat diffusion equation led to a precise characterization of the thermal field inside the dam. However, that approach may be computationally expensive. This paper proposes the use of a new one-dimensional model based on an explicit finite difference scheme which is improved by means of the reported methodology for computing the heat fluxes through the dam faces. The improved model has been applied to a case study where observations from 21 concrete thermometers and data of climatic variables were available. The results are compared with those from: (a) the original one-dimensional finite difference model, (b) the Stucky-Derron classical one-dimensional analytical solution, and (c) a three-dimensional finite element method. The results of the improved model match well with the observed temperatures, in addition they are similar to those obtained with (c) except in the vicinity of the abutments, although this later is a considerably more complex methodology. The improved model have a better performance than the models (a) and (b), whose results present larger error and bias when compared with the recorded data.

• Restorative Dentistry and Endodontics
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• v.28 no.6
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• pp.485-490
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• 2003

Complete understanding of the exterior and interior structure of the tooth would be prerequisite to the successful clinical results, especially in the restorative and endodontic treatment. Although three-dimensional reconstruction method using x-ray microtomography could not be used in clinical cases, it may be the best way to reconstruct the morphologic characteristics of the tooth structure in detail without destructing the tooth itself. This study was done to three dimensionally reconstruct every teeth in the arch in order to increase the understanding about the endodontic treatment and to promote the effective restorative treatment by upgrading the knowledge of the tooth morphology. After placing tooth between the microfocus x-ray tube and the image intensifier to obtain two-dimensional images of each level. scanning was done under the condition of 80 keV, $100{\;}\mu\textrm{m}$, 16.8 magnification with the spot size of $8{\;}\mu\textrm{m}$. Cross-section pixel size of $16.28{\;}\mu\textrm{m}$ and 48.83 cross-section to cross-section distance were also used. From the results of this study, precise three dimensional reconstructed images of every teeth could be obtained. Furthermore, it was possible to see image that showed interested area only, for example. enamel portion only, pulp and dentin area without enamel structure, pulp only, combination image of enamel and pulp, etc. It was also possible to see transparent image without some part of tooth structure. This image might be used as a guide when restoring and preparing the full and partial crown by showing the positional and morphological relationship between the pulp and the outer tooth structure. Another profit may be related with the fact that it would promote the understanding of the interior structure by making observation of the auto-rotating image of AVI file from the various direction possible.

• Journal of Chest Surgery
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• v.21 no.4
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• pp.649-655
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• 1988

One hundred and one patients with tetralogy of Fallot who were older than 16 years of age underwent a total correction of the anomaly between May, 1964 and July, 1987. This group comprised 14.9% of the 679 consecutive patients who had repair of the tetralogy at our institution during the same period. Of the 101 patients, 8 had a previous shunt procedure for palliation. The preoperative mean hemoglobin value was 16.9*1.0% and the mean systemic oxygen saturation, 84.4*0.9%. In 76 patients[75.2%], a type II ventricular septal defect was seen whereas in 14 patients[13.9%], the defect was type I. In 72 patients[71.3%], other cardiac anomalies were present which included patent foramen ovale in 37.6%, atrial septal defect in 8.99b, vegetations in 6.9%, right sided aortic arch in 5.9% and coronary artery anomaly in 5.0%. The right ventricular outflow obstruction was caused most commonly by combination of infundibular and valvular stenosis[74.3%], followed by isolated infundibular stenosis[19.8%] and valvular stenosis [5.9%] alone in order. The preoperative mean diameter of the pulmonary valve ring size was 10.2*0.5 mm in diameter. A transannular patch enlargement of the right ventricular outflow tract was performed in 28 patients and, in 12 a pericardial monocusp was utilized. Major anomalous aorto-pulmonary vessels were encountered in 5 patients which were detected before or during the operation. In 3 patients, they were ligated beforehand to control the flooding of the operative field. Postoperatively, the mean systolic pressure gradient between the right ventricle and the main pulmonary artery was 16.2*2.3 mmHg and the mean systolic pressure- ratio between the right and the left ventricle was 45.3*2.0%. Perioperative complications including bleeding in 8.9%, pleural effusion in 7.9%, dysrrhythmia in 4.9%, and residual VSD in 4.0%. Operative mortality was 8.9%. There has been no operative death in the recent 65 cases since 1981. There were 2 late deaths, 68 and 113 months after surgery. There were 2 late detachment of the VSD patch during the follow-up period. Of the 6 patients with patch detachment found during the postoperative period, 3 had subacute bacterial endocarditis before or after the operation indicating The serious nature of this complication. Two of these patients subsequently underwent a successful reoperation.

• Geomechanics and Engineering
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• v.34 no.1
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• pp.103-113
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• 2023

This study focused on understanding the relationship between the design of a tunnel boring machine disc cutter ring and its rock-breaking efficiency, as well as the applicable conditions of different cutter ring types. The discrete element method was used to establish a numerical model of the rock-breaking process using disc cutters with different ring types to reveal the development of rock damage cracks and variation in cutter penetration load. The calculation results indicate that a sharp-edged (V-shaped) disc cutter penetrates a rock mass to a given depth with the lowest load, resulting in more intermediate cracks and few lateral cracks, which leads to difficulty in crack combination. Furthermore, the poor wear resistance of a conventional V-shaped cutter can lead to an exponential increase in the penetration load after cutter ring wear. In contrast, constant-cross-section (CCS) disc cutters have the highest quantity of crack extensions after penetrating rock, but also require the highest penetration loads. An arch-edged (U-shaped) disc cutter is more moderate than the aforementioned types with sufficient intermediate and lateral crack propagation after cutting into rock under a suitable penetration load. Additionally, we found that the cutter ring wedge angle and edge width heavily influence cutter rock-breaking efficiency and that a disc cutter with a 16 to 22 mm edge width and 20° to 30° wedge angle exhibits high performance. Compared to V-shaped and U-shaped cutters, the CCS cutter is more suitable for soft or medium-strength rocks, where the penetration load is relatively small. Additionally, two typical case studies were selected to verify that replacing a CCS cutter with a U-shaped or optimized V-shaped disc cutter can increase cutting efficiency when encountering hard rocks.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.430-437
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• 2007

The probability table of Moyers and prediction equation of Tanaka and Johnston that have been the most frequently used, cannot produce accurate prediction when used in Korean because they are based on the Caucasian popularity of the Northern European race. The method of Moyers or Tanaka and Johnston predicts sizes of the unerupted canine and premolars on the basis of the sizes of mandibular incisors. However, some of the recent papers raise a question as to whether the mandibular incisors are the best combination to predict the sizes of the unerupted canine and premolars. The purpose of this study is to determine which sum or combination of sums of permanent tooth widths present the best prediction for the unerupted canine and premolars in a Korean sample, to calculate a specific linear regression equation for this population, and to evaluate the clinical significance. A new linear regression equation was calculated based on the data of 178 Korean young adults(70 women, 108 men, mean age 21.63 years) with complete permanent dentitions. Fifty three more children(28 girls, 25 boys, mean age 14.22 years) were used as a validation sample for the application of the multiple linear regression equation. The conclusions were as follows: 1. The combination of the sums of permanent upper central incisors, lower lateral incisors and upper first molars was the best predictor for the unerupted canine and premolars in this sample($r=0.65{\sim}0.80$). 2. The multiple linear regression equation was calculated including sex and arch as additional predictor variables. male, upper: $Y\;=\;0.332{\times}X_0\;+\;6.195$ male, lower: $Y\;=\;0.332{\times}X_0\;+\;5.269$ female, upper: $Y\;=\;0.332{\times}X_0\;+\;5.929$ female, lower: $Y\;=\;0.332{\times}X_0\;+\;5.003$. The determination coefficient of the equation was 64% and a standard error of the estimate was 0.71mm. 3. In about 97% of the validation sample, the estimation of the tooth width sums of unerupted canine and premolars using the new multiple linear regression equation was smaller than 1mm compaired with the actual values.