• Geomechanics and Engineering
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• 제38권3호
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• pp.285-305
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• 2024

This study investigates the behaviour of hunchback retaining walls supporting unsaturated sandy backfill under active earth pressure conditions. Utilizing a horizontal slice method and a unified effective stress methodology, the influence of various factors on lateral earth pressure, including the position of the hunch along the wall, friction angles, and wall heights, is explored. The results suggest that relocating the hunch position from close to the wall's top to near its base leads to a significant decrease (ranging from 54% to 81%) in lateral earth pressure. However, as the hunch position transitions from near the top to mid-height, the point of application of active thrust shifts upward initially, then slightly downward as the hunch position approaches the toe. Notably, the reduction in lateral earth pressure is more pronounced for shorter wall heights and higher friction angles. Building upon these findings, an Artificial Neural Network (ANN)-based model is developed to accurately predict the lateral earth pressure coefficient and point of application, achieving R² values of 0.94 and 0.93, respectively. In addition, an analytical model based on Coulomb's earth pressure theory is presented and compared with ANN models. These models are anticipated to assist designers and practitioners in optimizing hunchback retaining walls for unsaturated backfill.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.612-617
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• 2014

It is generally known that the automotive road wheel involves the non-proportional multiaxial loading condition, therefore the measuring dynamic stress and strain in driving state is very important to predict an endurance characteristic of the automotive road wheel. In this study, the ultimate driving test using F1 circuit with respect to 2 kinds of velocity conditions have been carried out in order to measure dynamic stress, strain of the wheel and acceleration of a vehicle. Based on the measured results, the characteristics of dynamic stress generation have been analyzed, and factors which have effect on the dynamic stress generation have been studied.

• 한국안전학회지
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• 제22권4호
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• pp.57-65
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• 2007

Effects on the stiffness of the embankment and sandmat on the construction safety of road embankment was investigated in this study by the numerical experiments using FEM. Two points was mainly focused in this study especially. First the deformation characteristics by the change of the stiffness of sand mat and embankment was investigated by the analyzing the consolidation settlement at the center of the embankment and the lateral displacement at the toe of the embankment. And, the effect of the stiffness on the stress distribution characteristics was also investigated in this study. Furthermore, slope stability analysis was carried out to gain the safe factor by change the stiffness of the sandmat and the embankment. The objective of the study is supplying the result of the numerical experiments for the geotechnical engineers who use the FEM for the safety design of the soil structures. As a result, the stiffness of the superstructures greatly affects on the deformation characteristics both in consolidation settlement and lateral displacement. However, it can be aware that it is not dominants to the stress distribution in the aspect that the no changes in the residual excess pore water pressure. Therefore, the decision of the stiffness has to be carried out deliberately considering not only the consolidation the magnitude of the settlement and the lateral displacement, but the slope stability.

• 대한전자공학회논문지SD
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• 제37권4호
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• pp.31-37
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• 2000

금속 유도 측면 결정화 (Metal-Induced Lateral Crystallization; MILC)에 의해 저온다결정 실리콘 박막트랜지스터를 형성할 때 Ni박막을 게이트와 소오스/드레인간 경계로부터 거리를 달리하여 형성한 뒤 결정화시킴으로써 소오스와 드레인으로부터 결정화가 진행되어 서로 만나는 경계 면을 채널 내부 외부에 인위적으로 위치시킬 수 있었고 이들의 전기적 특성비교를 통하여 MILC경계가 트랜지스터 특성에 미치는 영향을 고찰할 수 있었다. MILC 경계를 채널 내부로부터 제거시킴으로써 On Current, Subthreshold slope 특성을 향상시킬 수 있었고 누설전류 특성도 크게 향상시킬 수 있었다. 채널 내부에 MILC 경계가 존재할 경우 전기적 스트레스를 인가함에 따라 누설전류의 양이 감소하였고, 전체 감소량은 채널 폭이 넓을수록 증가하였고 채널길이에는 무관하였다.

• 한국지반공학회지:지반
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• 제8권4호
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• pp.5-16
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• 1992

본 연구에서는 다짐 유발응력 (compaction induced stress)을 고려한 보강토 설계방법을 고안하였다. 현행 보강토 설계법은 다짐에 의해 유발되는 횡방향토압을 정량적으로 고려하지 라고 있으므로, 본 연구는 먼저 다짐 유발응력 산정방법을 검토하고 다음에 이를 보강토 설계에 통용 함으로써 새로운 설계방법을 제안하였다. 다짐 유발응력들 고려하면 벽체의 위쪽 부분에 토압이 산정되므로 이 부분에는 인장강도와 인발저항이 큰 보강재 사용이 바람직하다. 이를 위하여 새로이 개발한 보강재 GEOLOG를 소개하였다. 새로운 방법으로 보강토 옹벽을 설계하고 이를 종래의 방법과 비교 분석하여 보강토 공법에 관한 몇가지 결론을 제시하였다.

• 한국재난정보학회 논문집
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• 제7권3호
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• pp.206-219
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• 2011

포장 설계기준에서 중요한 요인은 응력과 변형률 분포도이다. 합리적인 응력과 변형률 분포도를 달성하기 위한 차량타이어의 접촉면적과 공기압은 매우중요하다. 본 연구에서는 이동하중 하에서 연성포장의 점탄성 특성에 관한 내용을 다루고 있으며 현장 측정시험을 통하여 실제 도로의 종횡변형률을 수치해석 결과와 비교분석 하였다. 포장거동에 대한 차량이동하중의 영향을 적절히 모사하기 위하여 단계하중을 이용한 3차원 유한요소 해석이 수행되었다. 점탄성 해석을 위하여 아스팔트 혼합물의 이완계수, E(t), 가 실험실에서 제작된 시료의 실험으로부터 측정되었다. 현장조사 결과에 의하면, 종횡변형률은 서로 상이한 값을 보였으며 전반적으로 변형률의 크기는 차량의 속도가 증가함에 따라 감소함을 보였다. 전반적으로 횡방향 변형률은 종방향 변형률에 비하여 작은값을 보였으며 그 차이는 횡방향에서 더욱 두드러진 경향을 보였다.

• 대한치과보철학회지
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• 제31권4호
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• pp.661-678
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• 1993

The purpose of this study was to analyze the stress distribution at supporting bone according to the types of endosseous implants. This investigation evaluated the stress patterns in rectangular photoelastic models produced by four different types of dental implants such as $Br\ddot{a}nemark$, screw type of Steri-Oss, blade type of Steri-Oss, IMZ with IMC and resin tooth using the techniques of quasi-three dimensional photoelasticity. All prostheses were casted in the same nonprecious alloy and were cemented or screwed on their respective implants and abutments. 20 kg of vertical load was applied on the central fossa of casted crown and 16 kg of inclined had was applied on the top third of distal surface of casted crown respectively. The results were as follows : 1. Under the vertical load, screw implants of Steri-Oss and $Br\ddot{a}nemark$ showed increasing stress condition between and around the screw threads along the implant lateral surface and cylindrical implant of IMZ showed the less stress condition along the lateral surface with concentration of stress mostly near the root apex. 2. Under the vertical load, the stress of Steri-Oss blade was distributed uniformly at the alveolar bone under the broad blade. 3. Under the inclined load, the stress concentration of Steri-Oss screw and $Br\ddot{a}nemark$ was developed highly around the mesiocervical bone area on the contralateral side to force application. The stress of $Br\ddot{a}nemark$ with flexible gold glod was more concentrated in the cervical bone area than that of Steri-Oss with stiff screw. 4. Under the inclined load, the stress of Steri-Oss blade broadly was distributed around the mesioceivical bone area and the lower and mesial bone area of the blade. 5. Under the Inclined load, IMZ implant showed the gap between c개wn and fixture due ta deformation of the IMC and IMZ was lower in stress concentration developed around the mesiocervical bone area than $Br\ddot{a}nemark$ and Steri-Oss screw. 6. Under the inclined load, the stress magnitude induced in the mesiocervical bone area of implants was in order of $Br\ddot{a}nemark$, Steri-Oss strew, IMZ and Stsri-Oss blade. 7. Tilting forces as compared to axial forces exerted greater magnitude of stress in the cervical bone area of the implant. 8. In respect of stress distribution, Steri-Oss blade was superior than any other implants and in respect of the stability by horizontal lone, IMB and $Br\ddot{a}nemark$ was inferior than any other implants.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.263-266
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• 1997

Three dimensional numerical model based on the finite element method(FEM) were developed to predict the mechanical behavior of hip implants. The purpose of this study is to investigate the stress distribution of two types of cementless total hip replacement femoral component -a straight stem and a curved stem, and to compare their effect on the stress shielding between two types by three dimensional finite element method. The authors analyzed von Mises stress in the cortex & stem and compared the stress between the straight and the curved stem. In comparison of stresses between two different design of femoral stem, there was 25% more decrease of stress in straight stem than curved stem in the medial cortex at proximal region. The straight stem had consistently much lower stresses than the curved stem throughout the whole medial cortex with maximum 70% reduction of stress. However, there was little change in stress between nature and 2 implanted femur throughout the lateral cortex. Stress of femoral stem was much higher in the straight stem than the curved stem up to 60%. The straight stem had more chance of stress shielding and a risk of fatigue fracture of the stem compared with the curved stem in noncement hip arthroplasty. In design of femoral stem still we have to consider to develop design to distribute more even stress on the proximal medial cortex.

• 지질공학
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• 제32권4호
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• pp.467-482
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• 2022

The Yeonghae basin is located at the northeastern part of the Yangsan fault (YSF; a potentially active fault). The study of the architecture of the Yeonghae basin is important to understand the activity of the Yangsan fault system (YSFS) as well as the basin formation mechanism and the activity of the YSFS. For this study, Digital Elevation Model (DEM) was used to highlight the marginal faults, and structural fieldwork was performed to understand the geometry of the intra-basinal structures and the nature of the bounding faults. DEM analysis reveals that the eastern margin is bounded by the northern extension of the YSF whereas the western margin is bounded by two curvilinear sub-parallel faults; Baekseokri fault (BSF) and Gakri fault (GF). The field data indicate that the YSF is striking in the N-S direction, steeply dipping to the east, and experienced both sinistral and dextral strike-slip movements. Both the BSF and GF are characterized dominantly by an oblique right-lateral strike-slip movement. The stress indicators show that the maximum horizontal compressional stress was in NNE to NE and NNW-SSE, which is consistent with right-lateral and left-lateral movements of the YSFS, respectively. The plotted structural data show that the NE-SW is the predominant direction of the structural elements. This indicates that the basin and marginal faults are mainly controlled by the right-lateral strike-slip movements of the YSFS. Based on the structural architecture of the Yeonghae basin, the study area represents a contractional zone rather than an extensional zone in the present time. We proposed two models to explain the opening and developing mechanism of the Yeonghae basin. The first model is that the basin developed as an extensional pull-apart basin during the left-lateral movement of the YSF, which has been reactivated by tectonic inversion. In the second model, the basin was developed as an extensional zone at a dilational quadrant of an old tip zone of the northern segment of the YSF during the right-lateral movement stage. Later on, the basin has undergone a shortening stage due to the closing of the East Sea. The second model is supported by the major trend of the collected structural data, indicating predominant right-lateral movement. This study enables us to classify the Yeonghae basin as an inverted strike-slip basin. Moreover, two opposite strike-slip movement senses along the eastern marginal fault indicate multiple deformation stages along the Yangsan fault system developed along the eastern margin of the Korean peninsula.

• Journal of Periodontal and Implant Science
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• 제46권2호
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• pp.96-106
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• 2016

Purpose: Stress distribution and mandible distortion during lateral movements are known to be closely linked to bruxism, dental implant placement, and temporomandibular joint disorder. The present study was performed to determine stress distribution and distortion patterns of the mandible during lateral movements in Class I, II, and III relationships. Methods: Five Korean volunteers (one normal, two Class II, and two Class III occlusion cases) were selected. Finite element (FE) modeling was performed using information from cone-beam computed tomographic (CBCT) scans of the subjects' skulls, scanned images of dental casts, and incisor movement captured by an optical motion-capture system. Results: In the Class I and II cases, maximum stress load occurred at the condyle of the balancing side, but, in the Class III cases, the maximum stress was loaded on the condyle of the working side. Maximum distortion was observed on the menton at the midline in every case, regardless of loading force. The distortion was greatest in Class III cases and smallest in Class II cases. Conclusions: The stress distribution along and accompanying distortion of a mandible seems to be affected by the anteroposterior position of the mandible. Additionally, 3-D modeling of the craniofacial skeleton using CBCT and an optical laser scanner and reproduction of mandibular movement by way of the optical motion-capture technique used in this study are reliable techniques for investigating the masticatory system.