• Magazine of the Korean Society of Agricultural Engineers
• /
• v.36 no.4
• /
• pp.73-86
• /
• 1994

Ths paper was aimed to investigate the effect of reinforcement for the deformation characteristics of clayey foundation. Among numerous improvement method of foundation, only geotextil-reinforced foundation and foundation with both geotextile and sand mat which were 2-dimensional model clayey foundations were selected for load test in order to obtain fundamental results in analizing the behavior of the foundation with geotextile. To scrutinize the behavior characteristics and effect of reinforcement, the model foundations were constructed with various conditions on the location of layout of geotextile, the number of layouts and the depth of sand mat As for the technique of the numerical analysis elasto-plastic constitutive model for clayey soil, beam element for geotextile and elastic model for sand were respectively employed. Interface element was introduced for the block between materials with different rigidity. Observed values and numerical results were compared with satisfactory correspondence, which proved that the numercial technique developed in this paper was available.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.11
• /
• pp.1925-1932
• /
• 2003

Topology optimization is widely accepted as a conceptual design tool for the product design. Since the resulted layout of the topology optimization is a kind of digital images represented by the density distribution, the seamless process is required to transform digital images to the CAD model for the practical use. In this paper, the general process to construct a CAD model is developed to apply for topology images based on elements. The node density and the morphology technique are adopted to extract boundary contour of the shape and remove the noise of images through erosion and dilation operation. The proposed method automatically generates point data sets of the geometric model. The process is integrated with Pro/Engineer, so that the engineer in practice can directly handle with curves or surfaces form digital images.

• Structural Engineering and Mechanics
• /
• v.14 no.2
• /
• pp.223-236
• /
• 2002

The main objective of the present paper is to address a formal procedure for orthotropic steel plates design. The theme of the proposed approach is to recast the design procedure into a mathematical programming model. The objective function to be optimized is the total weight of the structure. The total weight is function of its layout parameters and structural element design variables. Mean while the proposed approach takes into consideration the strength and rigidity criteria in addition to other dimensional constraints. A nonlinear programming model is developed which consists of a nonlinear objective function and a set of implicit/explicit nonlinear constraints. A transformation method is adopted for minimization strategy, where the primal model constrained problem is transformed into a sequence of unconstrained minimization models. The search strategy is based on the well-known Fletcher/Powell algorithm. The finite element technique is adopted for discretization and analysis strategies. Mindlin theory is selected to simulate the finite element model and a selective reduced integration scheme is exploited to avoid a shear lock problem.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.5_6
• /
• pp.202-213
• /
• 2007

A network is an important model widely used in natural and social science as well as engineering. To analyze these networks easily it is necessary that we should layout the features of networks visually. These Graph-Layout researches have been performed recently according to the development of the computer technology. Among them, the Scale-free Network that stands out in these days is widely used in analyzing and understanding the complicated situations in various fields. The Scale-free Network is featured in two points. The first, the number of link(Degree) shows the Power-function distribution. The second, the network has the hub that has multiple links. Consequently, it is important for us to represent the hub visually in Scale-free Network but the existing Graph-layout algorithms only represent clusters for the present. Therefor in this thesis we suggest Graph-layout algorithm that effectively presents the Scale-free network. The Hubity(hub+ity) repulsive force between hubs in suggested algorithm in this thesis is in inverse proportion to the distance, and if the degree of hubs increases in a times the Hubity repulsive force between hubs is ${\alpha}^{\gamma}$ times (${\gamma}$??is a connection line index). Also, if the algorithm has the counter that controls the force in proportion to the total node number and the total link number, The Hubity repulsive force is independent of the scale of a network. The proposed algorithm is compared with Graph-layout algorithm through an experiment. The experimental process is as follows: First of all, make out the hub that exists in the network or not. Check out the connection line index to recognize the existence of hub, and then if the value of connection line index is between 2 and 3, then conclude the Scale-free network that has a hub. And then use the suggested algorithm. In result, We validated that the proposed Graph-layout algorithm showed the Scale-free network more effectively than the existing cluster-centered algorithms[Noack, etc.].

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.3
• /
• pp.309-314
• /
• 2014

The structural layout of mechanical and civil structures is commonly obtained using conventional methods. For example, the shape of structures such as electric transmission towers and offshore substructures can be generated systematically. However, with rapid advancements in computer graphic technology, advanced structural analyses and optimum design technologies have been implemented. In this study, the structural shape of a jacket substructure for an offshore wind turbine is investigated using a topology optimization technique. The structure is subjected to multiple loads that are intended to simulate the loading conditions during actual operation. The optimization objective function is defined as one that ensures compliance of the structure under the given boundary conditions. Optimization is carried out with constraints on the natural frequency in addition to the volume constraint. The result of a first step model provides quick insights into the optimum layout for the second step structure. Subsequently, a 3D model in the form of the frustum of a quadrilateral pyramid is developed through topology optimization.

• Geomechanics and Engineering
• /
• v.29 no.2
• /
• pp.145-154
• /
• 2022

Complex geological conditions have a great influence on the mining of coalbed methane (CBM), which affects the extraction efficiency of CBM. This investigation analyzed the complicated geological conditions in the Liujia CBM block of Fuxin. A geological model of heterogeneities CBM reservoirs was established to study the influence of strike direction of igneous rocks and fault structures on horizontal well layout. Subsequently, the dual-porosity and dual-permeability mathematical model was established, which considers the dynamic changes of porosity and permeability caused by gas adsorption, desorption, pressure change. The results show that the production curve is in good agreement with the actual by considering gas seepage in matrix pores in the model. Complicated geological structures affect the pressure expansion of horizontal wells, especially, the closer to the fault structure, the more significant the effect, the slower the pressure drop, and the smaller the desorption area. When the wellbore extends to the fault, the pressure expansion is blocked by the fault and the productivity is reduced. In the study area, the optimal distance to the fault is 70 m. When the horizontal wellbore is perpendicular to the direction of coal seam igneous rock, the productivity is higher than that of parallel igneous rock, and the horizontal well bore should be perpendicular to the cleat direction. However, the well length is limited due to the dense distribution of igneous rocks in the Liujia CBM block. Therefore, the horizontal well pumping in the study area should be arranged along the direction of igneous rock and parallel plane cleats. It is found that the larger the area surrounded by igneous rock, the more favorable the productivity. In summary, the reasonable layout of horizontal wells should make full use of the advantages of igneous rock, faults and other complex geological conditions to achieve the goal of high and stable production.

• Journal of The Korean Association of Information Education
• /
• v.16 no.4
• /
• pp.409-418
• /
• 2012

In recent years many people are changing their mobile phones from feature phones to smart phones because huge number of useful smart phone applications are released onto the market everyday. Development of smart phone applications could be very helpful educational contents for technologically gifted children who has lots of curiosity and creativity. For this reason this paper deals with development of smart phone application UI(User Interface) layout education programs for the technologically gifted children. These education programs which can operating under Android-based smartphone, have been developed by using JAVA and Eclipse. Survey from the technologically gifted children education experts has been analyzed by Delphi method to figure out effectiveness of the developed education programs.

• Science of Emotion and Sensibility
• /
• v.16 no.4
• /
• pp.545-556
• /
• 2013

This study has established the GUI design elements of mobile phones as color, text, layout, graphic icon, and video, under the purpose of exploring the relevance between such elements and brand preference among senior citizens. To accomplish the objective, a model and hypotheses were established, which were tested through a multiple regression analysis. The findings are as follows. First, when the statistical significance was examined by GUI design element of mobile phones, the following results were obtained: Color, text, layout, graphic icon, and video were statistically significant at the significance level given, indicating that such elements all affect brand preference. Second, the relative influence of GUI design elements of mobile phones on brand preference was revealed in the following order: text, color, video, graphic icon, layout. It indicates that boosting the brand preference of senior citizens for mobile phones requires considering 'text' and 'color' first before any other element. In addition, as the influence of 'text' and 'color' becomes greater, the brand preference also becomes higher.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.8
• /
• pp.621-629
• /
• 2020

LRU layout is a complex problem that requires consideration of various criteria such as airworthiness, performance, maintainability and environmental requirements. As aircraft functions become more complex, the necessary equipment is increasing, and unmanned aerial vehicles are equipped with more equipment as a substitute for pilots. Due to the complexity of the problem, the increase in the number of equipment, and the limited development period, the placement of equipment is largely dependent on the engineer's insight and experience. For optimization, quantitative criteria are required for evaluation, but criteria such as safety, performance, and maintainability are difficult to quantitatively compare or have limitations. In this study, we consider the installation and maintenance of the equipment, simplify the deployment model to the traveling salesman problem, Optimization was performed using a genetic algorithm to minimize the weight of the connecting cable between the equipment. When the optimization results were compared with the global calculations, the same results were obtained with less time required, and the improvement was compared with the heuristic.

• Journal of Biosystems Engineering
• /
• v.8 no.2
• /
• pp.86-98
• /
• 1983

본 연구는 미국의 사료공장 중 주종을 이루고 있는 형식을 분석하여 일반적인 Model로 개발하였고 이 Model을 설계할 수 있는 Computer Program을 개발하였다. Model에 적용된 규모는 10ton/hr로부터 50ton/hr이었고 종류는 돼지 및 닭 사료공장과 완전히 pellet화된 소 사료공장이었다. 개발된 Computer Program은 1개의 Main Program과 3개의 Subprogram으로 구성되어 있고 29개의 Input data을 사용하게 되어 있다. 이 Computer Program의 output은 다음과 같다. 1. 공장의 Dimension 2. 곡물저장 및 원료 bin의 수량 및 규모 3. 각 기계의 규모 및 성능 4. 총 작업시간 및 전기 소요량 위와같은 사료공장의 일반화 된 Model 및 이를 설계하기 위한 Computer Program은 사료 생산의 소요동력, 노동력 및 투자자본까지 추정할 수 있게 하였으며 이 분야에서 학문적으로 처음 시도하여 본 것이다.