• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.46-52
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• 2003

In this study, the full scale testing method of the geogrid-reiuorced soil Segmental Retaining Walll(SRW) under the simulated train loading were proposed in order to evaluate the applicability of reinforced soil SRW in railway embankment. The train loading was simulated by the design static wheel load and the impact coefficient due to the train passing velocity. This test was focused on the static performance of reinforced soil SRW in terms of the following measuring systems ; the horizontal earth pressure displacement acting on the facing block and the tensile strain along the geogrid. The data gathered from this full scale testing was compared with numerical analysis results by FLAC.

• The Journal of Advanced Prosthodontics
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• 제2권1호
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• pp.1-3
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• 2010

BACKGROUND. Even though excellent impression materials are now available for making accurate replication for hard and soft tissue, the numerous dentists have faced lots of obstacles in making simultaneous impressions of multiple abutments. CASE DESCRIPTION. This article describes a modified method of tray fabrication using auto-polymerizing acrylic resin and impression technique for multiple prepared teeth in cases with limitations and difficulties in taking dental impressions. CLINICAL IMPLICATION. This segmental tray technique has several advantages, including higher impression quality, fewer impressions, and being more comfortable for the patient and less stressful for the clinician.

• 디지털융복합연구
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• 제20권4호
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• pp.159-168
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• 2022

본 연구는 외식동기요인을 기초로 하여 세분집단을 분류한 다음 인구통계학적 특성과 이용행태별, 이용동기가 외식점 선택행동과의 미치는 영향관계를 분석하고자 2021년 7월 15일부터 8월 14일 한달간 설문조사를 실시하였고 총 310부를 실증분석에 사용하였다. 연구결과 첫째, 외식동기에 따른 세분집단간 인구통계학적 특성에 따라서 미치는 영향관계에서 업무형은 남성이 여성보다 높게 나타났고, 군집수가 많은 변화형, 식도락형, 적합형은 여성이 높게 나타났다. 둘째, 인구통계적특성에서 모든 집단들이 공통적으로 31-40세, 41-50세의 기혼자들이 외식동기가 강한 것으로 나타났다. 셋째, 외식동기에 따른 세분집단간 이용행태적 차이에서 가장 선호하는 메뉴는 변화형을 제외한 업무형, 식도락형, 적합형은 한식이 가장 높았고, 변화형은 양식이 가장 높았다. 넷째, 세분집단간 이용행태적 차이의 주문방식에서 4개의 집단이 모두 무한리필이나 뷔페식보다는 주문식이 높게 나타났다. 본 연구의 한계점으로는 분야를 한정하여 분석이 이루어 져야 하지만 특정음식종목에 대하여 연구결과를 얻지 못하였다. 따라서 향후 연구에서는 특정 음식분야를 지정하여 구제적인 연구가 이루어지길 바란다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.186-189
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• 2003

Precast Segmental method was developed in germany 1950s. This method has been adoptted in long span girder mainly owing to easy construction effect. But, so far, The limit exists that this method is constructed in a portion of span and hard conveyance and foundation. This study was performed to analysis behavior difference of two rectanglar section girder, spliced girder that was jointed 5-sliced 0.8m segment and monolithic girder that was produced in one body 4m span

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1990년도 가을 학술발표회 논문집
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• pp.101-104
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• 1990

The program which could determine cross-sectional dimensions of the box girder bridge at tile stage of preliminary design was developed using the optimal technique in this study. It could minimize the cost and time required in the design of box girder bridges and the construction with the prestressed precast segmental method. Objective cost function consisted of four independent variables such as widths and depth of the cross-section. The Nelder-Mead method was used to solve the nonconstrained nonlinear problem like this.

• Journal of Korean Neurosurgical Society
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• 제38권4호
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• pp.255-258
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• 2005

Objective : Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. Methods : We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. Results : Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was $1.96^{\circ}$. Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. Conclusion : Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

• Archives of Reconstructive Microsurgery
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• 제16권2호
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• pp.100-107
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• 2007

Treatment of giant cell tumor of distal radius can be treated in several ways according to the aggressiveness of the tumor. But the management of giant cell tumor involving juxta-articular portion has always been a difficult problem. In some giant cell tumors with bony destruction, a wide segmental resection may be needed for preventing to recur. But a main problem is preserving of bony continuity in bony defect as well as preservation of joint function. We have attempted to overcome these problems by using a microvascular technique to transfer the fibula with peroneal vascular pedicle or anterior tibial vessel as living bone graft. From April 1984 to July 2005, we performed the reconstruction of wide bone defect after segmental resection of giant cell tumor in 14 cases, using Vascularized Fibular Graft, which occur at the distal radius. VFG with peroneal vascular pedicle was in 8 cases and anterior tibial vessel was 6 cases. Recipient artery was radial artery in all cases. Method of connection was end to end anastomosis in 11 cases, and end to side in 3 cases. An average follow-up was 6 years 6 months, average bone defect after wide segmental resection of lesion was 6.8 cm. All cases revealed good bony union in average 6.5 months, and we got the wide range of motion of wrist joint without recurrence and serious complications. Grafted bone was all alive. In functional analysis, there was good in 7 cases, fair in 4 cases and bad in 1 case. Pain was decreased in all cases but there was nearly normal joint in only 4 cases. Vascularized fibular graft around wrist joint provided good functional restoration without local recurrence.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.305-308
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• 2008

이 연구에서는 최근 연구가 활발히 진행되고 있는 조립식 프리캐스트 세그먼트 콘크리트 교각공법에서 사용되어지는 기성 콘크리트 세그먼트의 횡 방향 구속철근에 의한 구속효과에 대한 연구를 수행하였다. 일반적으로 횡방향 구속철근에 의한 콘크리트의 구속효과는 구속효과계수에 의하여 결정되며 구속효과계수는 유효 구속 콘크리트 단면적과 구속 콘크리트 단면적의 비로서 결정된다. 유효 구속 콘크리트 단면적은 횡 방향 구속철근간의 간격에서 발생하는 Arching action에 의하여 결정되어지며 구속 콘크리트 단면적은 교각의 주철근비에 의하여 결정되어진다. 그러나 프리캐스트 콘크리트 세그먼트의 경우 세그먼트 상, 하부에 존재하는 피복을 고려하여야 한다. 즉 최상단 및 최하단에 배근되는 횡방향 구속철근에서 상, 하부 콘크리트 표면의 피복까지의 구속효과를 고려하여야 한다. 이 연구에서는 이에 대한 고려 방법을 제안하였다. 제안한 프리케스트 구속효과를 고려한 콘크리트 재료 모델을 RCAHEST에 적용하여 그 타당성을 검증하였다.

• 한국지반공학회논문집
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• 제24권9호
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• pp.23-32
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• 2008

본 논문에서는 계단식 형태로 시공되는 블록식 보강토 옹벽의 전체 안정성이 고려된 설계에 관한 내용을 다루었다. 다양한 계원과 이격거리로 설계된 네 가지 설계사례에 대해 현재 통용되고 있는 FHWA 및 NCMA 설계기준에 근거하여 내 외적 안정해석을 수행하고 그 결과를 토대로 두 설계기준의 차이점을 검토하였다. 아울러 대상옹벽에 대해 한계평형해석에 근거한 사면안정해석과 연속체역학 기반의 강도감소기법 해석을 수행하여 계단식 옹벽의 설계를 지배하는 파괴 메카니즘을 고찰하였다. 그 결과 내 외적 안정성 공히 FHWA에서 채택하고 있는 설계기준이 NCMA 보다 보수적인 결과(낮은 안전율)를 주는 것으로 나타났다. 또한 계단식 옹벽의 보강재의 소요 포설 길이는 전반적으로 전체 안정성에 좌우되는 것으로 검토되었으며 상부 옹벽의 보강재의 길이는 현 설계기준 보다 현저히 증가시켜야 하는 것으로 검토되었다.

• Structural Engineering and Mechanics
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• 제20권6호
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• pp.673-693
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• 2005

A general step-by-step simulation for the time-dependent analysis of segmentally-erected prestressed concrete box-girder bridges is presented. A three dimensional finite-element model for the balanced-cantilever construction of segmental bridges, including effects of the load history, material nonlinearity, creep, shrinkage, and aging of concrete and the relaxation of prestressing steel was developed using ABAQUS software. The models included three-dimensional shell elements to model the box-girder walls and Rebar elements representing the prestressing tendons. The step-by-step procedure allows simulating the construction stages, effects of time-dependent deformations of materials and changes in the structural system of the bridges. The structural responses during construction and throughout the service life were traced. A comparison of the developed computer simulation with available experimental results was conducted and good agreement was found. Deflection of the bridge deck, changes in stresses and strains and the redistribution of internal forces were calculated for different examples of bridges, built by the balanced-cantilever method, over thirty-year duration. Significant time-dependent effects on the bridge deflections and redistribution of internal forces and stresses were observed. The ultimate load carrying capacities of the bridges and the behavior before collapse were also determined. It was observed that the ultimate load carrying capacity of such bridges decreases with time as a result of time-dependent effects.