• Journal of Chest Surgery
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• 제27권10호
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• pp.862-867
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• 1994

We experienced two cases of dissecting aneurysm[DeBakey type III] of the thoracic aorta treated using intraluminal sutureless graft. Controversy still exists about the exact timing of surgical intervention for dissection of the descending thoracic aorta. The surgical indication of dissecting aneurysm[DeBakey type III] is continuous flow in the false lumen, continuous chest pain, compromise of arterial supply to a specific organ or limb, or extension of the dissection while the patient is receiving satisfactory medical treatment. Surgical therapy for dissection of the aorta has had a high mortality. One contributing factor has been hemorrhage from the prosthesis and the suture lines. Recently, a new method of treatment with a intraluminal sutureless graft that requires no end-to-end anastomosis has been developed. In our cases, cardiopulmonary bypass and circulatory arrest was utilized in repairing dissecting aneurysm of descending aorta[DeBakey type III] in order to avoid the aortic cross clamping because of friable aortic intima. The basic technique consists of vertical incision of descending aorta in the area of intimal tear and inserting the whole ringed graft into the true lumen of the dissected aorta and circumferentially ligating the aorta against the groove in the rings. Postoperative course was uneventful.

• 한국염색가공학회지
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• 제28권1호
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• pp.33-39
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• 2016

The crystal structure of nylon 56 fibers post extended by drawing process was investigated by synchrotron x-ray scattering measurement. In as-cast fiber, distinct (004) and (020) diffraction peaks were observed and they were related to initial metastable alignment of nylon molecules. With increase in the drawing ratio, (110) peak intensity was increased in vertical direction with decreasing (020) peak. At the same time, (004)' peak evolved position tilted to 29 degrees from the (004) peak. This evolution is directly related to stable crystalline phase of nylon 56 originated from additional formation of hydrogen bondings between N-H and C=O by post drawing process. We also compared density variation, stress-strain curves of the fiber as a function of drawing ratio and strain. The variations of density and tanacity also supported the increase of stable structure of nylon 56.

• 복합신소재구조학회 논문집
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• 제1권1호
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• pp.9-15
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• 2010

In this paper, A reinforced concrete slab bridges is analyzed by the composite laminates theory. Both the geometry and the material of the cross section of the reinforced concrete slab bridge are considered symmetrical with respect to the mid-surface so that the bending extension coupling stiffness, Bij = 0, and D16 = D26 = 0. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This slab with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and specially orthotropic laminates theory are used for analysis. The result of specially orthotropic laminates theory analysis is modified to obtain the solution of the beam analysis. The result of this paper can be used for reinforced concrete slab analysis by the engineers with undergraduate study in near future.

• Ocean Systems Engineering
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• 제1권4호
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• pp.317-336
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• 2011

A time domain finite element based method is employed to analyze wave radiation by multiple cylinders. The nonlinear free surface and body surface boundary conditions are satisfied based on the perturbation method up to the second order. The first- and second-order velocity potential problems at each time step are solved through a finite element method (FEM). The matrix equation of the FEM is solved through an iteration and the initial solution is obtained from the result at the previous time step. The three-dimensional (3D) mesh required is generated based on a two-dimensional (2D) hybrid mesh on a horizontal plane and its extension in the vertical direction. The hybrid mesh is generated by combining an unstructured grid away from cylinders and two structured grids near the cylinder and the artificial boundary, respectively. The fluid velocity on the free surface and the cylinder surface are calculated by using a differential method. Results for various configurations including two-cylinder and four-cylinder cases are provided to show the mutual influence due to cylinders on the first and second waves and forces.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.359-365
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• 2008

As housing supply ratio has become over 100%, the strategic vision of government's policies has been changed from new construction to maintenance and regeneration of old architectural-structures. This fact has brought a light on the reconstruction and remodeling industries and a need for retrofit and rehabilitation techniques of existing foundation. Various methods of foundation for architectural-structures do exist. Among them, micropiling technologies are increasingly applied in foundation rehabilitation and seismic retrofitting projects. Micropiling techniques provide environmental-friendly methods for minimizing disturbance to adjacent structures, ground, and the environment. The installation is possible in restrictive area and general ground conditions. The fact that the installation procedures cause minimal vibration and noise and require very low ceiling height makes the micropiling methods to be commonly used for underpin existing structures. Specialized drilling equipment is often required to install the micropiles for existing basement facilities. This paper presents a case study in which micropiles were constructed to support a superstructure for vertical extension of existing elevator core and provide accessibility to underground parking lot. It is intended to become useful reference for the similar remodeling project.

• 한국어류학회지
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• 제12권1호
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• pp.20-24
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• 2000

1996년에서부터 1999년까지 일본 Kochi현의 Shirano-hana에서 채집된 청베도라치과 어류 6개채 (체장 20.6~52.0 mm)률 채집하여 동정한 결과, 지금까지 일본에서는 서식이 보고되지 않은 Istiblennius dussumieri (Valenciennes, 1836)로 확인되어, 일본산 미기록종으로 보고한다. I. dussumieri는 가슴지느러미 연조수가 14개, 척추골수가 38~42개, 안상피돌기는 가지가 나있고, 둥지느러미에는 파상형의 무늬가 있으며, 체측에는 7~10개의 어두운 횡대가 있으며, 양턱에는 견치가 없다는 점이 특징적이다. 본 종은 Kuroshio 난류에 의해 이동되어 서식하고 있는 것으로 사료되나, I. dussumieri의 지리적 분포에서 서태평양 일대의 최북단 출현 지역으로 나타나고 있어 주목되었다.

• 한국지진공학회논문집
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• 제22권5호
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• pp.299-309
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• 2018

Now that problems with force-based seismic design have been clearly identified, design is inclined toward displacement-based methods. One such widely used method is Direct-Displacement-Based Design (DDBD). Yet, one of the shortcomings of DDBD is considering higher-mode amplification of story shear, moments, and displacements using equations obtained from limited parametric studies of regular planar frames. In this paper, a different approach to account for higher-mode effects is proposed. This approach determines the lateral secant stiffness of the building frames that fulfill the allowable inter-story drift without exceeding the desired story displacements. Using the stiffness, an elastic response spectrum analysis is carried out to determine elastic higher-mode force effects. These force effects are then combined with DDBD-obtained first-mode force effects using the appropriate modal superposition method so that design can be performed. The proposed design procedure is verified using Nonlinear Time History Analysis (NTHA) of twelve planar frames in four categories accounting for mass and stiffness irregularity along the height. In general, the NTHA response outputs compared well with the allowable limits of the performance objective. Thus, it fulfills the aim of minimizing the use of NTHA for planar frame buildings, thereby saving computational resources and effort.

• The Journal of Korean Physical Therapy
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• 제26권2호
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• pp.117-122
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• 2014

Purpose: The purpose of this study was to compare the effects of force of ipsilateral versus contralateral cane usage on knee moments in healthy young adults. Methods: A convenience sample of 10 subjects volunteered for this study. Subjects walked over a force plate under three different conditions; unaided and ipsilateral cane and contralateral cane. Analysis of data on moment of the knee joint and ground reaction force was performed using the OrthoTrak program. Results: Flexion moment of the knee was decreased with the contralateral cane, but increased with the ipsilateral cane compared with normal gait. Extension moment of the knee was decreased with the contralateral cane compared with normal gait(p<0.05) and it was showed a greater decrease with the contralateral cane than with the ipsilateral cane gait(p=0.00). Valgus moment of the knee joint was increased with the ipsilateral cane but decreased with the contralateral cane. Vertical ground peak force was decreased with the ipsilateral cane compared with normal gait (p<0.05). Conclusion: The following conclusions were drawn from our data. Contralateral cane gait is more efficacious for persons with weakness of knee extensors, however, for a patient with varus deformity, the cane should be used in the ipsilateral hand.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.68-73
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• 2005

In succession of the previous works, seismo-acoustic analysis was conducted to collect ground truth events and to discriminate surface explosions from natural earthquakes in the Korean Peninsula for 2004. In this period, total 510 seismo-acoustic events corresponding to 10.8 percent of total seismic events occurred in and near the Korean Peninsula were analyzed and discriminated as artificial surface explosions. Events distribution of the seismo-acoustic events in 2004 is similar to the previous results of 1999-2003. And newly determined seismo-acoustic events were added to the surface explosions database. To extend infrasound detection capability, Korea Institute of Geoscience and Mineral Resources (KIGAM) and Southern Methodist University (SMU) installed new seismo-acoustic array (BRDAR) in Baekryoung Island last November, 2004. The array configuration and design is nearly same to previous seismo-acoustic arrays CHNAR, KSGAR, a triangular 1 km aperture. BRDAR consists of 5 short period vertical seismometers (GS-13) in seismic vaults and 13 microbarometers (Chaparral Model 2). Preliminary analysis using data collected from BRDAR shows an extension of infrasound detection capability to western part of the Korean Peninsula. Also, multiple observations of infrasound at BRDAR and other arrays gave an opportunity to localize sound source regions.

• 자원환경지질
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• 제11권4호
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• pp.143-167
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• 1978

The Sangdong tungsten (mostly scheelite) mine is located on the southern limb of a major syncline, the Hambaeg syncline, in a thick sequence of lower Paleozoic sedimentary rocks in the mideastern part of south Korea. Productive scheelite mineralization in Sangdong area is confined to one single formation, the Myobong Slate. Four major ore beds, which have an lateral extension over than 1 km and were not heavily subjected to spatial disturbance, are developed in the Myobong Formation. The original materials of the ore-comprising horizones were probably of either calcareous or silceous sediments. The four ore beds, especially in the case of Main ore bed, display both lateral and vertical zoning. Association quartz-mica-scheelite is predominant in the central, while association hornblende-quartz-diopside-scheelite, diopside-garnet and wollastonite-garnet are developed in this order towards the periphery of the ore beds. Petrologically, two phases of thermometamorphism are recognized. The first phase is represented by the association wollastonite-garnet and diopside-garnet, while the second phase by the association hornblende-quartz-diopside-scheelite and quartz-mica-scheelite. The associations of the second phase do constitute prodctive ore. The high background value of tungsten in the area surrounding the Sangdong mine reveals that the area can be considered a geochemical zone enriched in tungsten. Studies on the trace element patterns were carried out to draw useful criteria for the purpose of future geochemical exploration in the area. The increasing trend of the ratio Rb $({\times}1000)/K_2O$ of the Myobong Slate towards the known mineralization area proved to be indicative for the presence of tungsten mineralization.