• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.149-161
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• 2019

In this study, the effect of the fluid flow characteristics on the length distribution of the fracture elements composing the fracture network is analyzed numerically using the 3D fracture crack network model. The truncated power-law distribution is applied to generate the length distribution of the fracture elements and the simulations of fluid flow are carried out with the exponent ${\beta}_l$ from 1.0 to 6.0. As a result of simulations, when the exponent ${\beta}_l$ increases, the length distribution of the fracture elements gradually decreases, and the connectivity between the fracture elements affecting the permeability of the fracture network becomes weak. When we analyzed the distributions of flow rate calculated at each fracture element with the exponent ${\beta}_l$, the mean flow rate at ${\beta}_l=1.0$ was estimated to be about 447 times larger than that at ${\beta}_l=6.0$ and for the flow calculated at the outflow boundary of the fracture network, the case of ${\beta}_l=1.0$ was estimated to be 6,440 times larger than that of ${\beta}_l=6.0$.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.1
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• pp.37-44
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• 2019

A bond-based peridynamic model has been reported dynamic fracture characteristic of brittle materials through a simple constitutive model. In the model, each bond is assumed to be a simple spring operating independently. As a result, this simple bond interaction modeling restricts the material behavior having a fixed Poisson's ratio of 1/4 and not being capable of expressing shear deformation. We consider a state-based peridynamics as a generalized peridynamic model. Constitutive models in the state-based peridynamics are corresponding to those in continuum theory. In state-based peridynamics, thus, the response of a material particle depends collectively on deformation of all bonds connected to other particles. So, a state-based peridynamic theory can represent the volume and shear changes of the material. In this paper, the perfect plasticity is considered to express plastic deformation of material by the state-based peridynamic constitutive model with perfect plastic flow rule. The elastic-plastic behavior of the material is verified through the stress-strain curves of the flat plate example. Furthermore, we simulate the high-speed impact on 3D granite model with a nonlocal contact modeling. It is observed that the damage patterns obtained by peridynamics are similar to experimental observations.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.90-98
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• 2011

This study aims to discuss the characteristics of garden architecture in Italian Renaissance Villa Lante that was constructed by the cardinal in Bagnaia at 16th century through actual survey and analysis of the garden's elements. To do this, it was studied in two ways: Analysis of the present conditions and review historical documents. The results are as follows. First, the buildings, the gardens and the surrounding landscapes are visually connected each other in relations between the topography and the surrounding landscapes. Second, the spatial composition accepted Neoplatonic law of multiple proportions and was influenced by ancient myth and "Liber ruralium commodorum" of Pietro de Crescenzi(1305). Third, the garden's elements consist of plants, buildings and items. In plants, the upper plants are fir tree, cypress and pine tree and the lower plants are english holly, box tree and sweet oleander. The buildings are casino, loggia and terrace. The items are pot, sundial, chair, viewing platform and fountain. The result of this study, the political and social, technical phenomena which constitute construction pattern affected the locational property and the spatial organization of the neighbor on Villa Lante.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.45-59
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• 2006

The successful performance of any numerical geotechnical simulation depends on the accuracy and efficiency of the numerical implementation of constitutive model used to simulate the stress-strain (constitutive) response of the soil. The corner stone of the numerical implementation of constitutive models is the numerical integration of the incremental form of soil-plasticity constitutive equations over a discrete sequence of time steps. In this paper a well known two-surface soil plasticity model is implemented using a generalized implicit return mapping algorithm to arbitrary convex yield surfaces referred to as the Closest-Point-Projection method (CPPM). The two-surface model describes the nonlinear behavior of coarse-grained materials by incorporating a bounding surface concept together with isotropic and kinematic hardening as well as fabric formulation to account for the effect of fabric formation on the unloading response. In the course of investigating the performance of the CPPM integration method, it is proven that the algorithm is an accurate, robust, and efficient integration technique useful in finite element contexts. It is also shown that the algorithm produces a consistent tangent operator $\frac{d\sigma}{d\varepsilon}$ during the iterative process with quadratic convergence rate of the global iteration process.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.05a
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• pp.35-81
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• 1998

Distinct Element Method(DEM) has a great advantage to model the discontinuous behaviour of jointed rock masses such as rotation, sliding, and separation of rock blocks. Geometrical data of joints by a field monitoring is not enough to model the jointed rock mass though the results of DE analysis for the jointed rock mass is most sensitive to the distributional properties of joints. Also, it is important to use a properly joint law in evaluating the stability of a jointed rock mass because the joint is considered as the contact between blocks in DEM. In this study, a stochastic modelling technique is developed and the dilatant rock joint is numerically modelled in order to consider th geometrical and mechanical properties of joints in DE analysis. The stochastic modelling technique provides a assemblage of rock blocks by reproducing the joint distribution from insufficient joint data. Numerical Modelling of joint dilatancy in a edge-edge contact of DEM enable to consider not only mechanical properties but also various boundary conditions of joint. Preprocess Procedure for a stochastic DE model is composed of a statistical process of raw data of joints, a joint generation, and a block boundary generation. This stochastic DE model is used to analyze the effect of deviations of geometrical joint parameters on .the behaviour of jointed rock masses. This modelling method may be one tool for the consistency of DE analysis because it keeps the objectivity of the numerical model. In the joint constitutive law with a dilatancy, the normal and shear behaviour of a joint are fully coupled due to dilatation. It is easy to quantify the input Parameters used in the joint law from laboratory tests. The boundary effect on the behaviour of a joint is verified from shear tests under CNL and CNS using the numerical model of a single joint. The numerical model developed is applied to jointed rock masses to evaluate the effect of joint dilation on tunnel stability.

• Cartoon and Animation Studies
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• s.30
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• pp.27-57
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• 2013

Animation which appeared with films in the late 19th century was a medium which came on obtaining nourishment from art historical style of modernism. However, the relation establishment between animation and modernism has been focused mainly on animation shapes, namely painted images. This sprang from explaining the relationship between animation and paintings, and for this reason, discussions of movements in animation were understood in tradition of chromophotograph of Muybridge and Jules Marey, or some characteristics owned by the live-action film. However, movements of animation were essentially different from the indexical sign of films or photogram, and objects of reproduction were different between them. Movements reproduced by animation are not ordinary movements, but expressions of or compressed movements and considerably systematic movements. As a result, these movements are far from reproduction of live-action film photogram. Rather, the logic of movements reproduced by animation comes near to controlling their motion scopes, time, distance etc. after dividing each part of the body. This is concluded in a standpoint of modern mechanism which is represented by Descartes and La Mettrie who tried to understand human body as a exchangeable machine. Design of modern mechanism ranging from modern society to industrial society and the age of modernism came to lead to analysis of physical motions of modern industrial society called composition of efficient movements understanding them as the law of nature rather than movements as nature. In the late 19th century, Taylor, F. W. and Gilbreth, Frank Bunker's studies of workers' working hours and 'motion study' were a way of constituting the frame of machine-human, which indicates that tradition of modern mechanism affected the entire modernism passing through industrial society. Further, we can see that motion studies conducted by them have almost similar characteristics to action analysis to study animation later in the name of 'timing'.

• Journal of Korean Elementary Science Education
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• v.40 no.4
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• pp.520-544
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• 2021

This study aims to develop a scientific creativity test for exploring the relationship between elementary students' creative process and product. For this, the researcher reviewed the literatures of scientific creativity and developed the items based on the constructs of creative process and product. After a review conducted by nine science education specialists, a pilot test, and additional revision and supplementation of observation test, the test, consisting of two sets-"animals" and "plants"-was finally conducted on 105 fifth-grade students. The test results were analyzed by using statistical analysis software. WinSteps, SPSS, and AMOS. The main findings from this study are as follows. First, when it comes to scientific creativity, creative process consists of science knowledge, inquiry skills, and creative thinking skills (divergent, convergent, and associative thinking skills). Creative product in science is a new and scientifically useful idea realized in a certain form. Second, observation, which was selected as a representative inquiry skill in this research, should not be related to creative thinking skills. Third, among the rest of the items, usefulness had the lowest averages, as it was, perhaps, difficult to satisfy the teachers' criteria for the scientific validity and usefulness. Fourth, the Spearman correlation coefficients between the items of "animals" and "plants" to find out the parallel-form reliability were significant, except for the item of originality. Fifth, the test was satisfactory with regard to the three aspects of construct validity-convergent, discriminant, and nomological. This study concludes by discussing the usefulness of this test, which has the possibility of exploring the relationship between creative process and product and of playing a role as an authentic evaluation tool in school.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.1
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• pp.88-95
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• 2017

In this paper, we present a saliency detection method using entropy weight and Weber contrast in the wavelet transform domain. Our method is based on the commonly exploited conventional algorithms that are composed of the local bottom-up approach and global top-down approach. First, we perform the multi-level wavelet transform for the CIE Lab color images, and obtain global saliency by adding the local Weber contrasts to the corresponding low-frequency wavelet coefficients. Next, the local saliency is obtained by applying Gaussian filter that is weighted by entropy of wavelet high-frequency subband. The final saliency map is detected by non-lineally combining the local and global saliencies. To evaluate the proposed saliency detection method, we perform computer simulations for two image databases. Simulations results show the proposed method represents superior performance to the conventional algorithms.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.102.2-102.2
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• 2015

진공 시스템의 기저상태를 지배하는 것은 대부분의 경우 용기 내면에 수십 단원자 층 정도로 흡착되어 있는 물이다. 용기 압력이 10-9 mbar 대가 될 때까지는 잔류기체의 90% 이상이 수분이고 압력을 10분의 1로 떨어뜨리려면 10배의 시간이 더 필요하다는 소위 1/t 법칙은 광범위한 흡착에너지를 가지는 물분자의 표면방출 특성으로 잘 설명되어진다. 용기가열 등 적극적인 표면처리를 하지 않고 전형적인 압력변화 양상은 그대로 유지하면서 절대적인 시간을 줄이는 가장 직접적인 방법은 물 배기속도를 가능한 한 높이는 것이지만 대부분의 고진공 펌프들에서 물배기속도만 더 증가하도록 만드는 것은 쉽지 않다. 크라이오 워터펌프(CWP: cryo-water pump)는 바로 이런 고민을 제대로 해결할 수 있는 유일한 실용적인 방안이라고 말할 수 있다. 다른 기체분자들의 배기는 일단 염두에 두지 않고 물배기만을 열심히 해서 배기시간을 단축하고 도달 진공도를 낮추는 것을 목표로 하는 장치가 CWP이다. CWP는 모든 기체에 반응하는 정통적인 크라이오 펌프에 비해 훨씬 간단하고 저렴하게 만들 수 있으면서도 진공 시스템에 큰 영향을 미칠 수 있지만 그동안은 물배기의 필요성에 대한 인식이 미흡하고, 또 부수적이고 추가적인 비용이 드는 것으로 생각되어 주목을 받지 못했지만 디스플레이와 반도체 산업을 필두로 물분압을 낮추고 생산수율을 높이는 것에 점점 더 관심이 높아지면서 CWP에 대한 수요도 높아지고 있다. CWP의 물배기는 아주 단순한 응축현상에 의존하므로 물리적으로 이해하고 성능을 예측하는 것이 직관적이지만 사용용도에 따라 물 이외의 기체분자들은 잘 통과시키면서 물배기는 최대화하는 최적설계가 요구되거나 터보분자펌프(TMP)와 같이 이질적인 고진공펌프와 조합하여 사용하는 경우 기체 온도 의존성을 고려해야 하는 등 까다로운 점이 있다. 본 보고에서는 CWP+TMP로 구성된 복합진공배기시스템을 설계하면서 CWP만의 물배기성능과 복합 시스템의 물 및 알곤 배기성능을 예측하고, 두 펌프의 상호관계에 대해 분석하며, 실제 만들어진 복합배기시스템을 사용하여 실험적으로 구한 물 및 알곤 배기속도 측정결과에 대해서도 간단하게 논의하려고 한다.

• Archives of design research
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• v.12 no.3
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• pp.43-52
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• 1999

For Bauhaus, the vaious typography experiments developed around the printing workshops, and it was only in the later Weimar Period that L. Moooly-Nagy, who came to be in charge of the rxinting workshops, approached it from the functional way of thinking and demanded print type reforms Using this as the basis, a new form of typograph called "typophoto" was developed by combining images and characters together using photography techniques and Bauhaus Unification Chaacter producyion. Harbert Bayer, striving at molds based on the ideologies of L. Moody-Nagy, prepared the framework for modern informational advertisements by producing a variety of advertisements based on several law of psychology and physiology. Bayer's successor, Joost Schmidt focused on lettering based on functionalism and typographic training and practice, while pioneering in the new area of display design wiwh efficient usage of space for exhibitions a1d dsplays. Thus, despite being carried doWl by the same leader in the sane era, the series of typographic experiments undertaken by the artists Bauhaus present guidelines to the direction modern visual communication must take through creativity and insight into the upcoming future that is not contained within the boundaries of traditions and customs.and customs.