• 콘크리트학회지
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• 제10권1호
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• pp.161-169
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• 1998

프리스트레스트 콘크리트 교량의 건설공법인 프리캐스트 세그멘탈 공법에서선형관리 기술은 핵심기술 중 하나이다. 그럼에도 불구하고 , 우리나라에서는 몇몇 교량기술자들에게 경험적으로 이해되고 있는 수준을 넘지 못하고 있다. 특히, 세그멘트의 제작에서부터 반드시 필요한 선형관리용 S/W 및 그 운용기술은 아직까지도 선진기술에 의존하고 있는 실정이다. 본 연구에서는 프리캐스트 세그멘탈 공법의 선형관리 기술에 대한 연구를 통하여 3차원적인 세그멘트 제작관리와 가설시 선형관리를 위한 제작선형을 자동적으로 계산할 수 있는 GEOCON을 개발하였다. 본 논문에서는 GEOCON의 알고리즘에 대하여 논하였으며, 특히 수치예제로서 제작오차의 발생위치에 따라 교량선형에 미치는 영향을 분석하였다.

• 대한수의학회지
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• 제55권1호
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• pp.47-52
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• 2015

The purpose of this study was to determine if contrast media would enhance visualization of the endocardium for assessment of left ventricle (LV) function. In addition, differences between pre- and post-contrast evaluation for the cardiac output measurements including the modified Simpson's method and automated contour tracking (ACT) method were examined. Ten clinically healthy adult beagle dogs (three males and seven females) between 2~3 years old and weighing 6.6~10.8 kg were used. Echocardiographic examinations were performed to compare pre- and post-contrast LV endocardium visualization using a segmental scoring method. Two different methods for measuring cardiac output were also compared. LV visualization was significantly enhanced in post-contrast echocardiography (p < 0.01). Significant differences between pre- and post-contrast measurements for the modified Simpson's method (p < 0.05) were also observed. No significant difference was found for the ACT method. Contrast echocardiography provides better LV chamber opacification and significantly improves wall segment visualization. Furthermore, contrast echocardiography for measuring cardiac output is helpful for the modified Simpson's method.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.28.1-28.6
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• 2016

Backgrounds: Insufficient intermaxillary space is caused by non-restoration following tooth extraction in the past, and this involves eruption of the opposing teeth and changes of the arch structure. Such cases are difficult just by a simple prosthetic approach, and diversified treatment plans should be established. Among these, posterior maxillary segmental osteotomy (PMSO) is an efficient treatment option than extraction of opposing teeth as it surgically repositions multiple erupted teeth and alveolar bone. PMSO can preserve the natural teeth; therefore, it is being regarded as a treatment method which can improve insufficient intermaxillary space significantly. Case presentation: In this case report, the first patient received PMSO in order to place an implant in the mandibular edentulous space after decreased vertical dimension is restored, and the second patient received PMSO along with orthodontic treatment to obtain the intermaxillary space and balance the interarch molar width. Conclusion: PMSO is the treatment of choice when occlusion is compromised in the presence of decreased vertical dimension or arch length discrepancy.

• Structural Engineering and Mechanics
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• 제65권6호
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• pp.741-750
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• 2018

The aim of this study was to investigate the mechanical responses of a high-speed railway shield tunnel subjected to impact by a derailed train, with emphasis on the protective effect of the secondary lining. To do so, the extended finite element method was used to develop two numerical models of a shield tunnel including joints and joint bolts, one with a cast-in-situ concrete secondary lining and one without such a lining. The dynamic responses of these models upon impact were analyzed, with particular focus on the distribution and propagation of cracks in the lining structures and the mechanical responses of the joint bolts. The numerical results showed that placing a secondary lining significantly constricted the development of cracking in the segmental lining upon the impact load caused by a derailed train, reduced the internal forces on the joint bolts, and enhanced the safety of the segmental lining structure. The outcomes of this study can provide a numerical reference for optimizing the design of shield tunnels under accidental impact loading conditions.

• 대한수의학회지
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• 제57권2호
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• pp.113-116
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• 2017

The aim of this study was to examine normal bronchi in dogs by using virtual bronchoscopy (VB) and to evaluate the utility of VB in clinical practice. The bronchi of six dogs without tracheobronchial disease were visualized by VB. Airways from the tracheal bifurcation to the lobar bronchi were well visualized in all dogs. Segmental and subsegmental bronchi were also well identified, but the degree and number of those varied with dog size. The mean numbers of segmental and subsegmental bronchi identified in the six dogs were 41.83 and 50.17, respectively, whereas, the mean numbers in medium- and large-sized dogs were 55.00 and 82.67, respectively, and in small-sized dogs, the means were 28.67 and 17.67, respectively. Although there were size-dependent differences in VB visualization of the bronchi, it was possible to identify peripheral airways to the subsegmental bronchi level, which can rarely be accomplished via conventional bronchoscopy. VB is the noninvasive method that can be used to examine bronchial anatomy, and our results suggest that VB can be useful for evaluating bronchi, including segmental and subsegmental ones that cannot be examined routinely by conventional bronchoscopy. Thus, VB has potential as an alternative to conventional bronchoscopy in the examination of bronchi in dogs.

• 한국지반공학회논문집
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• 제19권6호
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• pp.115-125
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• 2003

본 논문에서는 계단식 형태로 시공되는 블록식 보강토 옹벽의 설계사례에 대한 검토 내용을 다루었다. 이를 위해 6개 현장에 대한 설계관련 자료를 수집하여 현재 통용되고 있는 한계평형기법 기반의 설계기준에 부합하는지 여부를 분석하였으며 이와 아울러 계단식 옹벽에서 중요한 검토 항목인 복합파괴 .유형에 대한 사면안정성 검토를 FHWA 설계기준에 근거하여 수행하였다. 검토결과 몇몇 옹벽은 현 설계기준에서 요구하는 내적 및 외적 안정성을 만족하지 않는 것으로 나타났으며 복합파괴에 대한 안정성 또한 만족하지 않는 것으로 나타났다. 본 연구에서 얻어진 결과를 토대로 실무적용시 유의 사항을 다루었다.

• Journal of Chest Surgery
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• 제48권4호
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• pp.285-288
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• 2015

In coronary artery bypass grafting, a diffusely diseased left anterior descending coronary artery (LAD) is an obstacle to achieving complete revascularization, consequently leading to the possibility of a poor prognosis. Long segmental reconstruction with or without endarterectomy is a revascularization method for treating diffusely diseased coronary arteries. Herein, we report a successful case of long segmental reconstruction of a diffusely diseased LAD using a left internal thoracic artery onlay patch after endarterectomy.

• 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.

• Investigative Magnetic Resonance Imaging
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• 제19권4호
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• pp.205-211
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• 2015

The human heart is a complex organ in which many complicated congenital defects may happen and some of them require surgical intervention. Due to the vast complexity of varied anatomical presentations, establishing an accurate and consistent nomenclature system is utmost important to facilitate effective communication among pediatric cardiologists, cardiothoracic surgeons and radiologists. The Van Praagh segmental approach to the complex congenital heart disease (CHD) was developed in the 1960s and has been used widely as the language for describing complex anatomy of CHD over the decades. It utilizes a systematic and sequential method to describe the cardiac segments and connections which in turn allows accurate, comprehensive and unambiguous description of CHD. It can also be applied to multiple imaging modalities such as echocardiogram, cardiac CT and MRI. The Van Praagh notation demonstrates a group of three letters, with each letter representative for a key embryologic region of cardiac anatomy: the atria, ventricles and great vessels. By using a 3-steps approach, we can evaluate complex CHD precisely and have no difficulties in communicating with other medial colleague. This pictorial essay revisits the logical steps of segmental approach, followed by a pictorial illustration of its application.