• Journal of Periodontal and Implant Science
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• v.41 no.1
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• pp.44-50
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• 2011

Purpose: Pathologic tooth migration (PTM) is a tooth displacement which is derived from imbalance of tooth retention force and is dominantly found out in maxillary anterior area. PTM in maxillary anterior area was tried to corrected with periodontal treatment and a clear aligner in this study and the result was evaluated clinically and radiographically. Methods: For the treatment of a patient with chronic periodontal disease accompanied by maxillary anterior pathologic tooth migration, clear aligner was applied to move teeth after a series of case-related periodontal therapy. Clinically, probing depth, gingival recession, clinical attachment level and mobility were measured pre- and post-treatment, and radiographic examination was performed as well. Results: Clinically, we found the decrease of the probing depth, gingival recession, clinical attachment level and mobility. And we could also acknowledge the reduction of vertical and horizontal dimension on infrabony defect radiographically. However, it is still controversial if there was an actual bone filling. Conclusions: Clear aligner is an effective appliance to move teeth since it costs little in terms of expense and time. In addition, it wraps whole crowns, providing advantages to deal with crowding, spacing, and size of arch. In short, clear aligner could be a useful treatment option for PTM patient, since it provides decreased probing depth, gingival recession, clinical attachment level, mobility and esthetical restoration.

• Journal of Chest Surgery
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• v.24 no.2
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• pp.153-160
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• 1991

Tetralogy of Fallot was repaired by a transatrial-transpulmonary approach in 91 of 250 patients treated surgically [including redo operations] between April 1986 and December 1989. Their age ranged from 6 months to 14 years [mean 39.7 months]. Associated cardiovascular anomalies were right aortic arch [n=22], ASD [n=12], PDA [n=5], persistent left SVC [n=5], and others [n=6]. PA index was measured pre-operatively since 1987 to estimate pulmonary artery size and safe total correction[mean 289$\pm$110mm2/BSA]. Eight patients received previous shunt take down procedure concomitantly. Pulmonary arteriotomy was extended through small pulmonary annulus to a minimal distance upon the right ventricular infundibulum and transannular patch was applied in 38 patients [41.3%], in 31 of them monocuspid patch was utilized. pRV/LV was measured at operation room in 77 patients [mean 0.58$\pm$0.36]. Operative mortality was 6.6% [6/91]. The causes of death were low cardiac output [n=5], arrhythmia[n=1] and respiratory failure [n=1]. At follow-up between 12 months and 57 months [mean 30.8 months] most patients were in New York Heart Association class I without cardiac medication. There was no late death, but reoperations were required in 3 patients to relieve residual right ventricular outflow obstruction. Thus successful repair of tetralogy of Fallot can be accomplished in most patients including infants by transatrial-transpulmonary approach and the better result can be anticipated with respect to postoperative right ventricular function and arrhythmia than the conventional transventricular approach.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.491-495
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• 1994

The ectopic eruption is defined rise to be abnormal eruption, which gives to displacement of the teeth and abnormal root resorption of adjacent teeth. The ectopic eruption of first permanent molar is approximately 2-4% of the population, most of them are in the maxilla, rarely in the mandible. In the case of the second permanent molars, most of them are found in the mandible for the reason of the arch length discrepancies and large size of the teeth. The ectopic erupted molars should be treated early in order to coordinate normal growth pattern and to obtain good occlusal support. So, this should be early diagnosed and treated. But, ectopically erupting molars are often self-corrected, hence periodic follow-up is required. The methods of the treatment are largely classified into surgical, surgical-orthodontic, and orthodontic method. Especially in orthodontic method, they are divided as follows; appliances that is positioned at the contact point for unlocking and the distal movement, fixed and removable appliance that is connected to more than one tooth, and occlusion guiding method after disking or extraction of the second deciduous molar. The report presents the good results in treating patients, whose chief complaint was ectopic eruption of mandibular permanent molars.

• Structural Engineering and Mechanics
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• v.31 no.6
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• pp.679-696
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• 2009

The paper aims at analyzing the stress distribution around an underground opening that is subjected to non-symmetrical surface loading with emphasis on opening shapes with sharp corners and the stress concentrations developed at these locations. The analysis is performed utilizing the BIE method coupled with the Neumann's series. In order to implement this approach, the special recurrent relations for half plane were proven and the modified Shanks transform was incorporated to accelerate the series convergence. To demonstrate the capability of the developed approach, a horseshoe shape opening with sharp corners was investigated and the location and magnitude of the maximum hoop stress was calculated. The dependence of the maximum hoop stress location on the parameters of the surface loading (degree of asymmetry, size of loaded area) and of the opening (the opening height) was studied. It was found that the absolute magnitude of the maximum hoop stress (for all possible surface loading locations) is developed at the roof points when the opening height/width ratio is relatively large or when the pressure loading area is relatively narrow (compared to the roof arch radius), and contrarily, when the opening height/width ratio is relatively small or when the surface pressure is applied to a relatively wide area, the absolute magnitude of the maximum hoop stress is developed at the bottom sharp corner points.

• Structural Engineering and Mechanics
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• v.24 no.1
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• pp.107-136
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• 2006

The present paper proposes a semi-empirical analytical expression that is capable of determining the shear strength of reinforced concrete beams with longitudinal bars, in the presence of reinforcing fibers and transverse stirrups. The expression is based on an evaluation of the strength contribution of beam and arch actions and it makes it possible to take their interaction with the fibers into account. For the strength contribution of stirrups, the effective stress reached at beam failure was considered by introducing an effectiveness function. This function shows the share of beam action strength contribution on the global strength of the beam calculated including the effect of fibers. The expression is calibrated on the basis of experimental data available in literature referring to fibrous reinforced concrete beams with steel fibers and recently obtained by the authors. It can also include the following variables in the strength previsions: - geometrical ratio of longitudinal bars in tension; - shear span to depth ratio; - strength of materials and fiber characteristics; - size effects. Finally, some of the more recent analytical expressions that are capable of predicting the shear strength of fibrous concrete beams, also in the presence of stirrups, are mentioned and a comparison is made with experimental data and with the results obtained by the authors.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.739-742
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• 2003

We have compared 2-D and 3-D fluid simulation results of alternating current plasma display panel (AC-PDP) cell with experimentally measured two kinds of excited Xe species $Xe^{\ast}(^{3}P_{1})$ and $Xe^{\ast}(^{3}P_{2})$ characteristics. Although direct experimental access and diagnostics of the discharge in a PDP cell is problematic due to the small cell size, some of experimental technologies have made it possible to diagnose the behavior of excited Xe species [1, 2]. The simulation shows the similar characteristics to the experimental results in the excited Xe species density distribution and the number of excited Xe atoms in anode and cathode region. In certain cases, we obtained the arch-shaped discharge path between two sustain electrodes due to the additional pulse applied to address electrode analogous to experiment. This long path discharge induced higher luminous and discharge efficiency compared to the standard case.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.129-137
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• 2000

This paper presents groundwater flow characteristics in discontinuous rock mass using fracture network program(NAPSAC) by statistical approach. Equivalent permeability coefficients are estimated from borehole data around Mabuk test tunnel site and fracture map on the arch of the tunnel. The reliability of fracture network model is obtained from determination of input data for statistical fracture network analysis from the real data(data of fracture network, data of hydraulic tests). The variation of permeability and mean anisotropic permeability coefficients are calculated from the realized model by increasing the size. As a result of analysis, a strong anisotropy of permeability is observed according to the direction of the fracture sets around the test tunnel.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.378-386
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• 2000

This paper presents groundwater flow characteristics in discontinuous rock mass using fracture network program(NAPSAC) by statistical approach. Equivalent permeability coefficients are estimated from borehole data around Mabuk test tunnel site and fracture map on the arch of the tunnel. The reliability of fracture network model is obtained from determination of input data for statistical fracture network analysis from the real data(data of fracture network, data of hydraulic tests). The variation of permeability and mean anisotropic permeability coefficients are calculated from the realized model by increasing the size. As a result of analysis, a strong anisotropy of permeability is observed according to the direction of the fracture sets around the test tunnel.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.40-49
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• 2010

The Purpose of this paper is to weld a rapid palatal expander using a continuous wave Nd:YAG laser. The rapid palatal expander has become a useful treatment method for severe maxillary transverse deficiencies and posterior crossbites. Rapid maxillary expansion is a well-established method to correct transverse maxillary deficiency and arch length discrepancy. The major process parameters studied in the present laser welding experiment were the positions of focus, laser power and travel speed of laser beam. We measured the fusion zone size and its shape using an optical microscope for the observation of cross-sectional area and tension stress of a rapid palatal expander welded. Through the experimental investigation, the optimum speeds and power of laser without deficiencies of weld cross-sectional area were obtained.

• Journal of Chest Surgery
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• v.15 no.4
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• pp.447-450
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• 1982

A 45 year old male officer was admitted due to upper substernal pain for 1 month, which was aggravated by swallowing. On past and family history, there was no specific history except heavy drinking. Simple chest x-ray revealed no specific abnormal findings. Preoperative esophagofiberscopy and Barium study showed midesophageal diverticulum, pulsion type, at about 2 cm below the left main bronchus. The opening of the diverticulum was located at the left posterolateral aspect of esophagus. Midesophageal false diverticulum, measuring 2 x 2 x 1 .S cm in size, was noted at about 5 cm under the aortic arch protruding through a slit-like muscular defect. After inversion of diverticular sac, interrupted sutures with 3-0 silks were done on muscular defect site, and mediastinal pleura was reinforced on the lesion with interrupted sutures. On 4th postoperative day, esophagography revealed no diverticulum or stenosis. Also esophagofiberscopy showed smooth mucosal tag without disturbance of passage. On 14th postoperative day, the patient was discharged uneventfully, and follow-up for 3 months after discharge revealed nothing abnormal symptoms. The authors report one case of midesophageal, pulsion type, false diverticulum.