• Magazine of the Korea Concrete Institute
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• v.10 no.1
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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.

• Korean Journal of Veterinary Research
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• v.55 no.1
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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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• v.38
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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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• v.65 no.6
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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.

• Korean Journal of Veterinary Research
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• v.57 no.2
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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.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.115-125
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• 2003

This paper presents the results of design case study on soil-reinforced segmental retaining walls in tiered configuration. Six different field walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was additionally performed based on the method recommended by FHWA design guidelines. The results indicate that the as-built designs of some of the walls examined do not meet the minimum factors of safety for the external and Internal stabilities, and for the compound failure mode. The implications of the findings from this study are discussed.

• Journal of Chest Surgery
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• v.48 no.4
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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.

• Journal of the Korean Geosynthetics Society
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• v.1 no.1
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• pp.31-41
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• 2002

This paper presents the results of stability analyses on soil-reinforced segmental retaining walls in a tiered arrangement. Four different walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was also performed based on the method recommended by FHWA design guidelines. The results indicate that the as-built designs of some of the walls examined do not meet the minimum factors of safety for the external and internal stabilities, and for the compound failure mode. The implications of the findings from this study are discussed.

• Journal of Power Electronics
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• v.14 no.5
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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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• v.19 no.4
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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.