• Geotechnical Engineering
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• v.7 no.4
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• pp.89-98
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• 1991

This paper presents the three-dimensional stability analysis of the homogeneous, isotropic soil Slopes. Rotational slides are assumed with a cylindroid central part terminated with log-spiral curved ends. The ratio of threeiimensional minimum factor of safety to two 4imensional case is examined and factor of safety changes are showed for the ratio of cylinder length to slope height. On touch babes the following conclusions may be made 1. Factors of safety computed for 3-D geometry differ considerablely from ordir,arty 2-D factor of. safety. Sinoe Fn 1 Fa2 exceeds unity, threeiimensional effects tend to increase the factor of safety. 2. A,B LIU increase, the value of Fb3/ Fs2 decreases. 3. The ratio of Fr/Fs2 appears to be very sensitive to c and values.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.7
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• pp.16-25
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• 2002

This paper presents a methodology and application for extracting parasitic inductances in a multi-level interconnect semiconductor structure by a numerical technique. In order to calculate the parasitic inductances, the distrubution of electric potential and current density in the metal lines are calculated by finite element method (FEM). Thereafter, the magneto-static energy caused by the current density in metal lines was calculated. The result of simulation is compared with the result of Grover equation about analytic simple structures, and 4 bit ROM array with a dimension of $13{\times}10.25{\times}8.25{\mu}m^3$ was simulated to extract the parasitic inductnaces. In this calculation, 6,358 nodes with 31,941 tetrahedra were used in ULTRA 10 workstation. The total CPU time for the simulation was about 150 seconds, while the memory size of 20 MB was required.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.60-67
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• 2009

This paper describes a development of system that enables the user to simulate the rockfall and landslide from slopes using physical engine. Until now, it will not be able to accomplish the virtual experiment of three-dimensional interpretation about slope informations, stability evaluation, the rockfall and landslide simulation, etc., because of absence of three-dimensional simulation systems which relates with slopes. With like that reason, this paper developed a simulator which is identical or similar the rockfall and the landslide where the possibility which will occur or occurred from actuality is high very actual condition from virtual experiment. For a simulator development, this paper uses the physical engine which is mainly used from computer game and animation development etc., And it will be show the process where the rockfall and landslide occurs with simulator. This simulator which sees the process where the rockfall and the landslide occur from three-dimension computer graphics theory and the physical engine, is a system which is the possibility of showing actual feeling. Therefore, the result of this paper is applied in vehicle travelling guidance system and intelligence traffic systematic etc., because of creates visual service and three-dimensional application of the slope information database which is developed in existing, and will be able to forecast the upgrade of user benefit planning and a service.

• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.97-107
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• 2007

Accurate evaluation of the slope stability by assuming failure block as the entire slope is considered to be apposite for the small scale slope, whereas it is not the case for the large scale slope. Hence, appropriate estimation of a failure block size is required since the safety factor and the joint strength parameters are the function of the failure block size. In this paper, the size of failure block was investigated by generating 3-dimensional rock joint system based on statistical data of joints obtained from research slope, such as joint orientation, spacing and 3-dimensional joint intensity. The result indicates that 33 potential failure blocks exist in research slope, as large as 1.4 meters at least and 38.7 meters at most, and average block height is 15.2 meters. In addition, the data obtained from 3 dimensional joint system were directly applicable to the probability analysis and 2 and 3 dimensional discontinuity analysis.

• Journal of the Korean Professional Engineers Association
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• v.18 no.3
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• pp.21-27
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• 1985

Earthen mass located beneth a sloping group surface, whether natural or manmade, have a tendency to move downward and outward under the influence of gravity. Unless this tendency is suitably counteracted by the Shearing resistances within the mass, a landslide occurs. Avoiding such instabilities is a major concern of the geotechnical engineer. The shearing behavior of a soil is determined empirically, i.e., by field tests or laboratory tests. This results are applied to the slope stability analysis. The factor of safety for slope stability analysis is much more sensitive to the choice of strength parameters as interpreted from soil tests than to the choice of the computational method of analysis. This paper was investigated the influence of the change in the factor of safety due to a change in one of the parameters, relative to the total change in the factor of safety due to change in all parameters. A conclusion may be reached with respect to the required precision definition of the different variables to limit uncertainties in the factor of safety to tolerable levels.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.751-756
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• 1991

In this paper, three dimensional magnetostatic fields are analysed using tetrahedral edge elements, magnetic vector potential and modified formulation of weighted residual method. If we define unknown variables in mesh edges, some conditions, such as Coulomb gauge condition in magnetic vector potential are naturally satisfied. So with less memory space, we can obtain more accurate solutions than the method where unknown variables are defined at nodes. Reliability and utility of this method are verified in two examples.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.343-344
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• 2017

우리나라는 산악지형 특성상 붕적층이 발달한 지역이 많아 도로나 건축물이 계획될 경우 일반적으로 이러한 지역을 배제하는 계획을 수립하게 된다. 그러나 현장 여건상 불가피하게 붕적층 구간을 포함한 건설 계획이 수립될 경우 지반 굴착, 사면 절취로 인해 지반 거동특성이 불안정할 수 있으므로 상세한 사전 조사와 적절한 토공 및 굴착 계획과 시공 중 Feed Back 등이 면밀히 이루어져야 한다. 붕적층 지반은 소량의 토사에 자갈, 호박돌, 전석 등이 혼재되어 있는 상태로 주로 테일러스에 의해 생성되며, 암괴의 함량이 매우 높으며 소량의 풍화된 잔류토사가 혼재된 양상을 보인다. 본 연구에서는 붕적층이 깊게 분포하는 지역, 특히 배면에 지장물(상수도관 등)문제로 인해 발생한 가시설 붕괴지역을 사례로 역해석을 통한 붕적층의 지반정수 재평가를 실시하였다.

• Geophysics and Geophysical Exploration
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• v.17 no.4
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• pp.216-230
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• 2014

Based on the interpretation of 3D seismic profiles acquired in the northwestern area of the Ulleung Basin, East Sea, the shallow sediments consist of five seismic units separated by regional reflectors. An anticline is present in the study area that documents activity of many faults. Bottom simulating reflectors are characterized by high RMS amplitude. Acoustic blanking with low RMS amplitude is distinctively recognized in the gas hydrate stability zone. Seismic attribute analysis shows that if gas hydrates are underlain by free gas, the high reflection strength and the low instantaneous frequency are displayed below the boundary between them. Whereas, if not, the reflection strength is low and instantaneous frequency is high continuously below the gas hydrate zone. Based on the spectral decomposition of the bottom simulating reflector, the high envelope at the specific high frequency range indicates the generation of the tuning effect due to the lower free gas content. Four models for the occurrence of the gas hydrate are suggested considering the slope of sedimentary layers as well as the presence of gas hydrate or free gas.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.4
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• pp.10-18
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• 2002

This paper reports a methodology for calculating distribution of the director in an In-plane switching liquid crystal cell by a numerical technique. To calculate distribution of the director, we developed a three dimensional finite element method (FEM) and calculated the distribution of electric potential and electric field in the liquid crystal cell. We have considered the free-energy density composed of electric potential and strain energy in the bulk of liquid crystal cell and calculated the switching property of liquid crystal cell by the Ericksen-Leslie equation and the Laplace equation We generated 1,859 nodes and 8,640 elements for IPS mode cell with 24${\mu}{\textrm}{m}$$\times$12${\mu}{\textrm}{m}$$\times$4.5${\mu}{\textrm}{m}$ and performed transient analysis until 16ms. As a result, horizontal electric field occurred at cell region except liquid crystal region above electrodes and the disclination occured on electrodes.

• Tunnel and Underground Space
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• v.29 no.5
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• pp.332-345
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• 2019

Maximum dip vector of individual joint plane, which can be uniquely defined on the hemispherical projection plane, has been established by considering its dip and dip direction. A new stereographic projection method for the rock slope analysis which employs the maximum dip vector can intuitively predict the failure modes of rock slope. Since the maximum dip vector is uniquely projected on the maximum dip point of the great circle, the sliding direction of discontinuity plane can be recognized directly. By utilizing the maximum dip vector of discontinuity both the plane sliding and toppling directions of corresponding blocks can be discerned intuitively. Especially, by allocating the area of high dip maximum dip vector which can form the flanks of sliding block the potentiality for the formation of virtual sliding block has been estimated. Also, the potentiality of forming the triangular-sectioned sliding block has been determined by considering the dip angle of joint plane the dip direction of which is nearly opposite to that of the slope face. Safety factors of the different-shaped blocks of triangular section has been estimated and compared to the safety factor of the most hazardous block of rectangular section. For the wedge analysis the direction of crossline of two intersecting joint planes, which has same attribute of the maximum dip vector, is used so that wedge failures zone can be superimposed on the stereographic projection surface in which plane and toppling failure areas are already lineated. In addition the maximum dip vector zone of wedge top face has been delineated to extract the wedge top face-forming joint planes the orientation of which provides the vital information for the analysis of mechanical behavior of wedge block.