• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2005년도 공동학술대회 논문집
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• pp.203-208
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• 2005

본 연구에서는 한반도 심부 지전기 구조에 대한 연구의 일환으로 경상분지 일대에서 자기지전류탐사(MT)를 수행하고 이를 해석하였으며, 한국지질자원연구원의 광역 중력 자료를 획득, 처리하여 보조 해석 기법으로 이용하였다. 경상분지 중 의성소분지를 가로지르는 포항에서 문경까지의 측선을 따라 총 21개 측점에서 MT 탐사를 수행하였고, 이 지역의 광역적인 지질구조를 살펴보기 위하여 이 측선을 대각선으로 하는 지역의 중력분포도를 함께 해석하였으며, MT 측선을 따라 중력 값을 추출하여 2차원 중력 역산을 수행하였다. 탐사 결과는 선행 연구로부터 해석된 경상분지와 의성소분지의 지질학적 구조와 일치하는 경향을 나타내고 있으며, 의성소분지 지역의 퇴적층과 주변의 화성암 및 변성암체와의 물성 차이를 확인할 수 있었다.

• 자원환경지질
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• 제29권3호
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• pp.335-343
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• 1996

The dipole-dipol electrical resistivity survey was conducted to investigate the probable contamination of the Han river by leachate from the near-by Nanjido Landfill. The survey line of 3 km was set along the unpaved road toward the Han river. For the convenience of the field work, the survey line was divided into four segments. The complete two-dimensional resistivity section was constructed by connecting the inversion result of each segment. Gravity survey was also carried out along the profile parallel to the resistivity line. Near surface resistivity generally appeared to be of very low value in most part of the survey area and the boundary between the alluvium layer and underlying basement rocks is well discriminated on the resistivity section. These results agree well with those of the preceding Schlumberger depth sounding made at adjacent area by Lee and fun (1995). The variation of thickness of the alluvium layer delineated by gravity anomaly profile also correlates well with the result of the resistivity survey on the qualitative basis. The problem of contamination by leachate from the Nanjido Landfill, where various waste materials have been dumped without any proper treatment facilities, has been remains unsolved yet. Therefore, we present the most probable passages of leachate flow based on the survey results and have briefly discussed about measure for contamination control. Considering the thickness of alluvium and the possible existence of fractured zone, the middle point between 1st and 2nd landfill and the midst of 1st landfill are the most hazardous regions to make leachates flow into the Han river. Since large amounts of leachates are observed from the test wells located on the lines extending from the border between the 1st and 2nd landfill and the middle of the lst landfill, contamination protection barriers are strongly recommended near these regions.

• 자원환경지질
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• 제36권4호
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• pp.305-312
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• 2003

본 연구는 중력자료를 이용하여 팔공산화강암체의 분포양샹, 인근지역의 지하 지질 및 지질구조, 경상분지와 영남 육괴와의 관계규명 등을 밝히는데 그 목적이 있다. 연구지역은 북위 35$^{\circ}$45'-36$^{\circ}$21', 동경 128$^{\circ}$15'-129$^{\circ}$00'에 해당한다. 중력자료는 서울대학교, 한국지질자원연구원, 부산대학교 및 연세대학교에서 측정한 기존의 중력자료 826개와 팔공산 화강암체를 포함하는 주변지역에서 금번에 측정된 중력자료 140개에 대해 계기보정, 조석보정, 위도보정, 푸리에어보정, 부게보정, 대기보정, 지형보정을 실시하여 부게중력이상을 구하였다. 연구지역의 부게중력이상은 -12.88∼26.01 mgal의 분포를 보이며, 평균치는 11.27mgal이다. 연구지역의 서쪽에 위치한 영남육괴에서는 평균에 비해 상당히 낮은 저 이상대를 보이며, 연구지역의 서쪽에서 동쪽으로 갈수록 이상값이 높아진다. 팔공산화강암체와 영남육괴 분포지역에서 부게중력이상이 낮게 나타나는 것은 이들의 밀도가 경상분지의 퇴적암보다 낮기 때문인 것으로 해석된다. 부게중력이상으로부터 지하에 존재하는 밀도 불연속면의 평균심도를 구하기 위해 진폭스펙트럼과 공간주파수를 이용한 파워스펙트럼분석을 실시한 결과, 밀도 불연속면의 평균 심도는 4.9 km와 10.4 km이며, 이는 각각 분지기반암과 콘라드면의 평균심도로 해석된다. 연구지역의 동쪽에서 갑자기 낮아지는 저이상대는 신령단층과 노고산 환상단층의 영향으로 해석된다 2차원 모델링에 의한 팔공산화강암체의 심도는 연구지역의 중앙을 기준으로 서쪽에서 동쪽으로 갈수록 감소한다. 각 측선의 2차원 모델링에 의한 팔공산화강암체의 분포 심도가 두 지점에서 첨예하게 깊게 나타나며, 각자의 심도는 측선 AAl에서는 5.3 km, 측선 BBl에서는 팔공산화강암체의 최대심도인 약 7 km이다. 또한, 팔공산화강암체 주변의 천부지역에는 작은 화강암체들이 관입해 있음을 알 수 있다. 각 측선별 2차원 모델링에 의해 얻어진 자료의 보간을 통해 구현한 3차원 해석으로부터 팔공산화강암체의 뿌리는 지표에 나타나는 팔공산화강암체를 중심으로 남서쪽부근에 위치하며, 지하에 분포하는 팔공산화강암체의 전체 부피는 약 31.211$Km^3$으로 추정된다.

• 한국결정성장학회지
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• 제14권4호
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• pp.160-168
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• 2004

We investigate the effects of solutal convection on the crystal growth rate in a horizontal configuration for diffusive-convection conditions and purely diffusion conditions achievable in a low gravity environment for a nonlinear thermal gradient. It is concluded that the solutally-driven convection due to the disparity in the molecular weights of the component A $(Hg_2Br_2)$ and B (CO) is stronger than thermally-driven convection for both the nonlinear and the linear thermal profiles, corresponding to $Gr_t= 8.5{\times}10^3,\; Gr_s = 1.05{\times}10^5$. For both solutal and thermal convection processes, the growth rates for the linear thermal profile (conducting walls) are greater than for the nonlinear case. With the temperature humps, there are found to be observed in undersaturation for diffusive-convection processes ranging from $D_{AB}$ = 0.087 to 0.87. For the vertical configurations, the diffusion mode is so much dominated that the growth rate and interfacial distribution is nearly regardless of the gravitational accelerations. Also, the diffusion mode is predominant over the convection for the gravity levels less than 0.1 $g_0$ for the horizontally oriented configuration.

• Steel and Composite Structures
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• 제26권5호
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• pp.621-634
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• 2018

Flush end-plate (FEP) beam-to-column joints are commonly used for gravity load resisting parts in steel multi-storey buildings. However, in seismic resisting structures FEP joints should also provide rotation capacity consistent with the global structural displacements. The current version of EN1993-1-8 recommends a criterion aiming at controlling the thickness of the end-plate in order to avoid brittle failure of the connection, which has been developed for monotonic loading conditions assuming elastic-perfectly plastic behaviour of the connection's components in line with the theory of the component method. Hence, contrary to the design philosophy of the hierarchy of resistances implemented in EN1998-1, the over strength and the hardening of the plastic components are not directly accounted for. In light of these considerations, this paper describes and discusses the results obtained from parametric finite element simulations aiming at investigating the moment-rotation response of FEP joints under cyclic actions. The influence of bolt diameter, thickness of end-plate, number of bolt rows and shape of beam profile on the joint response is discussed and design requirements are proposed to enhance the ductility of the joints.

• 한국유체기계학회 논문집
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• 제15권1호
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• pp.46-51
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• 2012

This study is to confirm the deformation of blade when the location of stacking is moving. Also, it desire to determine the most stable location of stacking from the analysis. In the previous study, it is Known that moving the location of stacking is not influence to the aerodynamic performance. In this study SolidWorks premium 2010 SP4 is used for structure analysis. In reference blade and other 3 model analysis, the two mesh type is used, one is standard mesh type in SolidWorks, the other is curvature-based mesh type. The result of curvature-based mesh type is more stable than one of the standard mesh type regardless of mesh size, the number of mesh. The deformation of blade tip is the smallest, when the location of stacking is identical to the center of gravity of the blade section profile. So, if possible is design, this study recommends that the location of stacking is identical to the center of gravity the blade.

• Structural Engineering and Mechanics
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• 제84권5호
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• pp.591-604
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• 2022

A gravity wall combined with an anchoring lattice frame (a combined retaining structure) is adopted at a typical engineering site at Dali-Ruili Railway Line China. Where, the combined retaining structure supports a soil deposit covering on different inclined rock slopes. With an aim to investigate and compare the effects of inclined rock slopes on the response of combined retaining structure under seismic excitation, three groups of shaking table tests are conducted. The rock slopes are shaped as planar surfaces inclined at angles of 20°, 30°, and 40° with the horizontal, respectively. The shaking table tests are supplemented by dynamic numerical simulations. The results regarding the horizontal acceleration response, vertical acceleration response, permanent displacement mode, and axial anchor force are comparatively examined. The acceleration response is more susceptible to outer structural profile of combined retaining structure than to inclined angle of rock slope. The permanent displacement decreases when the inclined angle of the rock slope increases within a range of 20°-40°. A critical inclined angle of rock slope exists within a range of 20°-40°, and induces the largest axial anchor force in the combined retaining structure.

• 한국석유지질학회지
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• 제1권1호
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• pp.37-46
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• 1993

한국근해 제 6광구내의 탄성파탐사 단면도에 대한 이차원의 중력 및 자력모델을 연구했다. 각 단층면에 대하여 사용된 모든 지층의 기하학적 형태를 보여주는 긴 모델과 중요한 부분을 확대한 모델을 작성했다. 이 모델연구 결과는 다음과 같은 사항들을 지시한다. (1) 보다 깊은 기반암까지의 심도는 탄성파탐사 단층면에서 보여주는 깊이보다 약간 깊은 것 같고, (2) 중기 마이오세 지층(모델에서 최심부층)은 무시못할 양의 화산물질을 포함하고 있는 것 같고, (3) 최하심층(중기 마이오세)에 포함된 두터운 화산암 물질 때문에 본 연구지역내에서 기반암의 상부면까지의 깊이를 정의하거나 결정하기가 어렵고, (4) 중기 마이오세 동안의 광범위하게 있었을 화산활동 때문에 본 연구지역은 탄화수소(석유 또는 천연가스)가 생성 또는 집적됐을 유망지역이 될 수 없다고 판단된다. 본 연구지역에서 가장 깊은 기반암까지의 깊이는 해수면에서 약 $4{\cal}km$이다.

• 한국임상수의학회지
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• 제38권2호
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• pp.63-68
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• 2021

Urethral obstruction is a life-threatening feline lower urinary tract disease (FLUTD). The rate of recurring urethral obstruction was 14.8-58.1% after the first occurrence. Ultrasonographic findings associated with reobstruction had been rarely reported although ultrasonography was a valuable technique for diagnosing urinary bladder calculi and distinguishing different FLUTD causes. This retrospective study aims to describe the ultrasonographic findings, urinalysis, and serum chemistry profile in cats with FLUTD and determine the associations of reobstruction with ultrasonographic findings, urinalysis, and serum chemistry profile. The present study included 141 cats that were followed up for more than 1 year. The ultrasonographic criteria included the presence of cystolithiasis, urine echogenicity, sediment, suspended linear strand, pericystic effusion, hyperechoic pericystic fat, ureteral dilation, pyelectasia, and perirenal effusion. The urinalysis criteria included hematuria, urine-specific gravity, pH, sediment, and proteinuria. The most common ultrasonographic findings in cats with FLUTD were echogenic urine and sediment. However, this study did not find an association between reobstruction and ultrasonographic findings, urinalysis, and serum chemistry profiles. Thus, an ultrasonographic examination may be insufficient to predict the risk of reobstruction although it is a useful modality for diagnosing FLUTD and making treatment direction.

• 로봇학회논문지
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• 제11권1호
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• pp.26-32
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• 2016

A variable release torque-based compliance spring-clutch (VCSC) is presented. VCSC is a safe joint to reduce the impact of collisions between humans and robots. It is composed of four functional plates, balls, springs to make some functions in compliant movement, release mechanism, gravity compensation during its work. Also, it can estimate torque applied to a joint by using distance sensor and parameters of cam profile. The measured variable torque of prototype is 4.3~7.6 Nm and release torque is 4.3 Nm. In our future studies, a calibration for torque estimation will be conducted.