• Structural Engineering and Mechanics
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• 제57권4호
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• pp.717-731
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• 2016

In orthopedic surgery and more especially in total arthroplastie of hip, the fixing of the implants generally takes place essentially by means of constituted surgical polymer cement. The damage of this materiel led to the fatal rupture and thus loosening of the prosthesis in total hip, the effect of over loading as the case of tripping of the patient during walking is one of the parameters that led to the damage of this binder. From this phenomenon we supposed that a remain of bone is included in the cement implantation. The object of this work is to study the effect of this bony inclusion in the zones where the outside conditions (loads and geometric shapes) can provoke the fracture of the cement and therefore the aseptic lousing of the prosthesis. In this study it was assumed the presence of two bones -type inclusions in this material, one after we analyzed the effect of interaction between these two inclusions damage of damage to this material. One have modeled the damage in the cement around this bone inclusion and estimate the crack length from the damaged cement zone in the acetabulum using the finite element method, for every position of the implant under the extreme effort undergone by the prosthesis. We noted that the most intense stress position is around the sharp corner of the bone fragment and the higher level of damage leads directly the fracture of the total prosthesis of the hip.

• 대한토목학회논문집
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• 제33권3호
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• pp.1007-1015
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• 2013

하중 발생과정에 따른 누적피해의 선형뿐만 아니라 비선형 거동을 해석할 수 있는 추계학적 확률모형이 수립되었다. 여러 종류의 피해강도함수를 도입하여 내용년수의 파괴확률과 비선형 누적피해의 거동이 자세히 해석되었다. 특히 본 연구에서는 저항한계를 임의의 분포함수를 갖는 확률변수로 취급하여 한계상태의 불확실성을 고려하였다. 또한 피복재에 대한 피해수준을 이용하여 처음으로 추계학적 확률모형을 경사제에 적용하였다. 실험 자료와의 비교를 통해 추정된 경사제 피복재에 대해 피해강도함수를 이용하여 내용년수에 따른 파괴확률과 비선형 누적피해의 거동을 해석하였다. 마지막으로 해석 결과를 이용하여 경사제 피복재의 보수 보강 시점과 최소한의 보수 보강규모를 정량적으로 산정할 수 있는 예방적 유지관리 방법을 제시하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권6호
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• pp.278-284
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• 2014

Objectives: This study used cone-beam computed tomography (CBCT) images to categorize the relationships between the mandibular canal and the roots and investigated the prevalence of nerve damage. Materials and Methods: Through CBCT images, contact and three-dimensional positional relationships between the roots of the mandibular third molar and the mandibular canal were investigated. With this data, prevalence of nerve damage according to the presence of contact and three-dimensional positional relationships was studied. Other factors that affected the prevalence of nerve damage were also investigated. Results: When the mandibular third molar and the mandibular canal were shown to have direct contact in CBCT images, the prevalence of nerve damage was higher than in other cases. Also, in cases where the mandibular canal was horizontally lingual to the mandibular third molar and the mandibular canal was vertically at the cervical level of the mandibular third molar, the prevalence of nerve damage was higher than in opposite cases. The percentage of mandibular canal contact with the roots of the mandibular third molar was higher when the mandibular canal was horizontally lingual to the mandibular third molar. Finally, the prevalence of nerve damage was higher when the diameter of the mandibular canal lumen suddenly decreased at the contact area between the mandibular canal and the roots, as shown in CBCT images. Conclusion: The three-dimensional relationship of the mandibular third molar and the mandibular canal can help predict nerve damage and can guide patient expectations of the possibility and extent of nerve damage.

• 대한원격탐사학회지
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• 제34권6_1호
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• pp.1033-1039
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• 2018

우리나라는 매년 여름철마다 태풍과 집중호우가 함께 발생하는 홍수로 인해 인명 및 재산피해가 발생한다. 특히 임진강 유역은 급경사와 좁은 하도인 상류부와, 낮은 평지인 하류부로 되어 있어 홍수에 취약한 지형을 가지고 있다. 게다가 북한 지역의 임진강 상류에 위치한 대형 댐인 황강댐에서 여름철 마다 무단방류로 인하여 피해가 발생하였다. 이런 홍수 피해를 방지하기 위해 우리나라에서는 2010년 군남홍수조절지를 건설하여 홍수피해를 방지하고 있다. 하지만 홍수조절지의 건설 이후에도 홍수조절능력이 황강댐의 최대 저수량의 20%밖에 미치지 못한다. 이에 이 연구에서는 경기북부지역의 집중호우시 발생할 수 있는 홍수 피해 위험지역을 산정하기 위하여 LAHARZ_py 프로그램을 이용하여 피해예상지역을 산출하였다. 그 결과 군남홍수조절지의 홍수조절능력을 넘는 황강댐의 방류가 발생할 시에 경기도 연천군과 파주시에 피해가 예상되었다. 추후 이 연구는 홍수 피해를 대비하기 위한 자료로 유용할 것으로 판단된다.

• 생태와환경
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• 제41권4호
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• pp.466-471
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• 2008

Little is known about DNA-level and physiological levels for health assessments of stream or river environments. Recently, comet assay, so called Single Cell Gel Electrophoresis (SCGE) is introduced for assessments of DNA damage in the medical science, food science and mammal toxicology. The comet assay is known as a biomarker which is one of the best barometers in assessing the DNA damage by oxidative stress. In this study, we conducted the comet assay using sentinel species, Zacco platypus, as one of the pre-warning alarm systems for the aquatic ecosystem health assessments and also applied it to Gap Stream as a model system. Tail extent moments in the S1 and S2 were 5.20 and 9.90 respectively and the moment was 19.89 in the S3. Statistical ANOVA in the tail moments showed a significant difference (n=75, p<0.05) between S1 and S3. Also, the proportions of DNA in the tail were 14.47, 23.64, and $30.04{\mu}m$ in the upstream (control site), midstream, downstream sites, respectively. Our results in the downstream were accord with previous studies of individual-level, population-level, and community-level in Gap Stream. Our results suggest that the comet assay may be used as an important tool for diagnosing ecological health of aquatic ecosystems in the level of DNA.

• 한국영양학회:학술대회논문집
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• 한국영양학회 2001년도 추계학술대회 초록
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• pp.49-49
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• 2001

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 추계학술발표회초록집
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• pp.63-63
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• 2003

• Earthquakes and Structures
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• 제23권5호
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• pp.445-462
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• 2022

To investigate and evaluate the seismic damage behaviors of steel reinforced recycled concrete (SRRC) filled circular steel tube composite columns, in this study, the cyclic loading tests of 11 composite columns was carried out by using the load-displacement joint control method. The seismic damage process, hysteretic curves and performance indexes of composite columns were observed and obtained. The effects of replacement rates of recycled coarse aggregate (RCA), diameter thickness ratio, axial compression ratio, profile steel ratio and section form of profile steel on the seismic damage behaviors of composite columns were also analyzed in detail. The results show that the failure model of columns is a typical bending failure under the combined action of horizontal loads and vertical loads, and the columns have good energy dissipation capacity and ductility. In addition, the replacement rates of RCA have a certain adverse effect on the seismic bearing capacity, energy consumption and ductility of columns. The seismic damage characteristics of composite columns are revealed according to the failure modes and hysteretic curves. A modified Park-Ang seismic damage model based on the maximum displacement and cumulative energy consumption was proposed, which can consider the adverse effect of RAC on the seismic damage of columns. On this basis, the performance levels of composite columns are divided into five categories, The interlayer displacement angle and damage index are used as the damage quantitative indicators of composite columns, and the displacement angle limits of composite columns at different performance levels under 80% assurance rate are calculated as 1/105, 1/85, 1/65, 1/28, and 1/25 respectively. On this basis, the damage index limits corresponding to each performance level are calculated as 0.045, 0.1, 0.48, 0.8, and 1.0 respectively. Finally, the corresponding relations among the performance levels, damage degrees, interlayer displacement angles and damage indexes of composite columns are established. The conclusions can provide reference for the seismic design of SRRC filled circular steel tube composite columns, it fills the vacancy in the research on seismic damage of steel reinforced recycled concrete (SRRC) filled circular steel tube composite columns.

• 한국강구조학회 논문집
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• 제21권5호
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• pp.493-503
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• 2009

교량의 여유도는 주부재의 손상시 하중을 지탱할 수 있는 능력으로서 거더 개수, 지간, 형고, 내부지점, 부부재 등의 다양한 인자가 영향을 미치게 된다. 그러나, AASHTO 및 국내 도로교설계기준과 같은 현행 규정에서는 교량의 여유도를 단지 주거더의 개수로만 정의하고 있고, 그 평가 방법 및 요구 수준은 아직 제시되지 않고 있다. 이에 본 연구에서는 플레이트거더교를 대상으로 심각한 피로손상이 발생한 경우 주요 인자들을 고려하고 신뢰도 기법에 기반하여 교량의 여유도 평가 기법을 제안하였다. 또한, LRFD법 기반의 기준 교량에 대해 손상 시 내하력 해석과 신뢰성 해석을 수행하여 여유도의 요구 수준을 목표 시스템 신뢰도 지수 형태로 제안하였다. 마지막으로 현행 ASD법으로 설계된 단순 및 연속 플레이트거더교의 거더 수에 따른 여유도 수준을 평가 제시하였다.

• Archives of Plastic Surgery
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• 제44권4호
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• pp.261-265
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• 2017

Periauricular paresthesia may afflict patients for a significant amount of time after facelift surgery. When performing face and neck lift surgery, temple and posterior auricular flap dissection is undertaken directly over the auriculotemporal, great auricular, and lesser occipital nerve territory, leading to potential damage to the nerve. The auriculotemporal nerve remains under the thin outer superficial fascia just below the subfollicular level in the prehelical area. To prevent damage to the auriculotemporal nerve and to protect the temporal hair follicle, the dissection plane should be kept just above the thin fascia covering the auriculotemporal nerve. Around the McKinney point, the adipose tissue covering the deep fascia is apt to be elevated from the deep fascia due to its denser fascial relationship with the skin, which leaves the great auricular nerve open to exposure. In order to prevent damage to the posterior branches of the great auricular nerve, the skin flap at the posterior auricular sulcus should be elevated above the auricularis posterior muscle. Fixating the superficial muscular aponeurotic system flap deeper and higher to the tympano-parotid fascia is recommended in order to avoid compromising the lobular branch of the great auricular nerve. The lesser occipital nerve (C2, C3) travels superficially at a proximal and variable level that makes it vulnerable to compromise in the mastoid dissection. Leaving the adipose tissue at the level of the deep fascia puts the branches of the great auricular nerve and lesser occipital nerve at less risk, and has been confirmed not to compromise either tissue perfusion or hair follicles.