• Geomechanics and Engineering
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• 제23권4호
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• pp.351-364
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• 2020

This paper numerically investigates the effects of a dip-slip fault (a normal or a reverse fault) movement on a segmental tunnel which transversely crosses either of this kind of faults. After calibration of the numerical model with results from literature of centrifuge physical tests, a parametric study is conducted to evaluate the effects of various parameters such as the granular soil properties, the fault dip angle, the segments thickness, and their connections stiffnesses on the tunnel performance. The results are presented and discussed in terms of the ground surface and tunnel displacements along the longitudinal axis for each case of faulting. The gradient of displacements and deformations of the tunnel cross section are also analyzed. It is shown that when the fault dip angle becomes greater, the tunnel and ground surface displacements are smaller, in the case of reverse faulting. For this type of fault offset, increasing the tunnel buried depth causes tunnel displacements as well as ground surface settlements to enhance which should be considered in the design.

• Clinical and Experimental Pediatrics
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• 제59권5호
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• pp.242-245
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• 2016

Thromboembolic complications (TECs) are clinically important sequelae of nephrotic syndrome (NS). The incidence of TECs in children is approximately 2%-5%. The veins are the most commonly affected sites, particularly the deep veins in the legs, the inferior vena cava, the superior vena cava, and the renal veins. Arterial thrombosis, which is less common, typically occurs in the cerebral, pulmonary, and femoral arteries, and is associated with the use of steroids and diuretics. Popliteal artery thrombosis in children has been described in cases of traumatic dissection, osteochondroma, Mycoplasma pneumoniae infection, and fibromuscular dysplasia. We report of a 33-month-old girl with bilateral iliac and popliteal arterial thrombosis associated with steroid-resistant NS due to focal segmental glomerulosclerosis. Her treatment involved thrombectomy and intravenous heparinization, followed by oral warfarin for 8 months. Herein, we report a rare case of spontaneous iliac and popliteal arterial thrombosis in a young child with NS.

• 대한치과교정학회지
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• 제50권4호
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• pp.278-289
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• 2020

Orthodontic treatment of posterior bite collapse due to early loss of molars and the consequent drift of adjacent teeth is complicated. When the posterior bite collapse occurs in patients with facial asymmetry, both transverse and vertical compensation are necessary for camouflage orthodontic treatment. In such cases, posterior maxillary segmental osteotomy (PMSO) can be an effective alternative procedure that simplifies the orthodontic treatment and shows long-term stability through dental compensation within the alveolar bone housing. This case report aimed to describe the orthodontic treatment of maxillary occlusal plane canting caused by severely extruded maxillary teeth in a patient with skeletal facial asymmetry that was corrected with PMSO along with protraction of the lower second molar to replace the space of the extracted first molar. The treatment duration was 18 months, and stable results were obtained after 2 years of retention.

• Archives of Plastic Surgery
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• 제41권5호
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• pp.584-587
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• 2014

In the present study, a fibular osteotomy guide based on a computer simulation was applied to a patient who had undergone mandibular segmental ostectomy due to oncological complications. This patient was a 68-year-old woman who presented to our department with a biopsy-proven squamous cell carcinoma on her left gingival area. This lesion had destroyed the cortical bony structure, and the patient showed attenuation of her soft tissue along the inferior alveolar nerve, indicating perineural spread of the tumor. Prior to surgery, a three-dimensional computed tomography scan of the facial and fibular bones was performed. We then created a virtual computer simulation of the mandibular segmental defect through which we segmented the fibular to reconstruct the proper angulation in the original mandible. Approximately 2-cm segments were created on the basis of this simulation and applied to the virtually simulated mandibular segmental defect. Thus, we obtained a virtual model of the ideal mandibular reconstruction for this patient with a fibular free flap. We could then use this computer simulation for the subsequent surgery and minimize the bony gaps between the multiple fibular bony segments.

• Archives of Reconstructive Microsurgery
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• 제25권2호
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• pp.69-71
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• 2016

Reconstruction of the lower extremities is difficult due to a lack of skin laxity and muscular tissues. Here, we present a case of lower extremity reconstruction via the anterior tibial artery perforator based segmental muscle island flap. Our patient was a 75-year-old male with a chronic ulcerative wound on the right lower leg from an old car accident. A $5.0{\times}0.5cm$ size ulcerative wound with tibial bone exposure was noted. We planned to reconstruct the lower extremity defect with a free flap, but the vessel status was severely compromised intraoperatively. Thus, we found the anterior tibial artery perforator using Doppler ultrasound, elevated the tibialis anterior muscle segment flap, and transposed it to cover the defect successfully. The flap presented with a nice contour and the skin graft covering the flap survived completely. There were no complications of the surgical site at three months follow-up and no gait morbidity. This is a meaningful case applying the concept of segmental muscle flap based on a perforator that had advantages including proper bulkiness, vascularization, and preservation of function, which were well applied, leading to great success.

• 한국지반신소재학회논문집
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• 제4권1호
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• pp.17-25
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• 2005

본 논문에서는 옹벽 시공 완료 후 여름철 집중강우로 인해 붕괴된 보강토 옹벽 사고사례에 대한 원인 분석을 실시하였다. 사고 원인의 명확한 규명을 위해 붕괴된 옹벽의 현장조사 및 실내시험, 현 설계법에 근거한 안정성평가, 강우의 침투해석 및 suction을 고려한 사면안정해석을 실시하였고, 그 결과 현장조건을 제대로 반영하지 못한 부적합한 설계와 불량한 뒤채움 흙의 사용, 단기간의 집중호우로 인한 suction의 감소 및 전단강도의 감소가 붕괴의 주원인인 것으로 나타났다.

• 한국지반신소재학회논문집
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• 제2권1호
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• pp.15-25
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• 2003

계단식 보강토 옹벽의 거동 특성을 파악하기 위하여 계단식 보강토 옹벽을 시험 시공하였으며, 수평변위와 보강재에 발생한 변형률을 중심으로 계측을 실시하였다. 특히 수평변위와 보강재 유발 변형률을 장기간 계측함으로써 계절변화에 따른 영향을 평가하였으며, 강우가 보강토 옹벽에 미치는 영향, 연약지반에서의 거동특성 등등에 초점을 맞춰 계측하여 분석을 실시하였다. 본 논문에서는 계단식 보강토 옹벽 시공 중에 발생하는 수평변위 및 보강재 유발변형률을 중심으로 분석하였고, 그 결과 상단옹벽 시공으로 인한 하단옹벽의 수평변위 및 보강재 유발 변형률은 상당히 많은 영향을 받고 있는 것으로 조사되었다.

• 한국지반신소재학회논문집
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• 제1권1호
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• pp.31-41
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• 2002

보강토 옹벽이 장대화 됨에 따라 보다 다단식 옹벽의 시공사례가 늘어가고 있다. 현재 NCMA 혹은 FHWA 설계기준에서 제시하고 있는 다단식 옹벽의 설계기준에서는 옹벽의 내 외적 안정성 검토에 주안점을 두고 상 하단 옹벽의 포설 조건을 설정하도록 제안하고 있으나 우리나라의 설계사례를 검토할 경우 설계기준에 부합되지 않는 경우가 많은 것으로 보고되고 있다. 본 논문에서는 우리나라 보강토 옹벽의 설계에서 그 이해가 부족한 부분이라고 할 수 있는 다단식 보강토 옹벽의 설계개념을 알아보았으며 NCMA 및 FHWA 설계기준에 근거하여 네 개의 현장옹벽에 대한 내 외적 안정성 및 복합파괴에 대한 안정성을 검토하였다. 아울러서 그 결과를 토대로 현재 우리나라에서 적용되고 있는 다단식 보강토 옹벽 설계의 문제점 및 이에 대한 대책 등을 언급하였다.

• Journal of Power Electronics
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• 제14권5호
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• pp.866-873
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• 2014

In this paper, a novel 12/8 segmental rotor type switched reluctance motor (SRM) is proposed for cooling fan applications. Unlike conventional structures, the rotor of the proposed structure is constructed from a series of discrete segments, and the stator is constructed from two types of stator poles: exciting and auxiliary poles. Moreover, in this structure, short flux paths are taken and no flux reversion exists in the stator. While the auxiliary poles are not wound by the windings, which only provide the flux return path. When compared with the conventional SRM, the proposed structure increases the electrical utilization of the machine and decreases the core losses, which may lead to a higher efficiency. To verify the proposed structure, the finite element method (FEM) and Matlab-Simulink are employed to get the static and dynamic characteristics of the proposed SRM. Finally, a prototype of the proposed motor was tested for characteristic comparisons.

• Geomechanics and Engineering
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• 제6권3호
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• pp.263-275
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• 2014

The development of transportation in large cities requires the construction of twin tunnels located at shallow depth. As far as twin tunnels excavated in parallel are concerned, most of the cases reported in literature focused on considering the effect of the ground condition, tunnel size, depth, surface loads, the relative position between two tunnels, and construction process on the structural lining forces. However, the effect of the segment joints was not taken into account. Numerical investigation performed in this study using the $FLAC^{3D}$ finite difference element program made it possible to include considerable influences of the segment joints and tunnel distance on the structural lining forces induced in twin tunnels. The structural lining forces induced in the first tunnel through various phases are considerably affected by the second tunnel construction process. Their values induced in a segmental lining are always lower than those obtained in a continuous lining. However, the influence of joint distribution in the second tunnel on the structural forces induced in the first tunnel is insignificant. The critical influence distance between two tunnels is about two tunnel diameters.