• Structural Engineering and Mechanics
• /
• v.44 no.5
• /
• pp.681-704
• /
• 2012

The dynamic response of Euler-Bernoulli beams to resonant harmonic moving loads is analysed. The non-dimensional form of the motion equation of a beam crossed by a moving harmonic load is solved through a perturbation technique based on a two-scale temporal expansion, which permits a straightforward interpretation of the analytical solution. The dynamic response is expressed through a harmonic function slowly modulated in time, and the maximum dynamic response is identified with the maximum of the slow-varying amplitude. In case of ideal Euler-Bernoulli beams with elastic rotational springs at the support points, starting from analytical expressions for eigenfunctions, closed form solutions for the time-history of the dynamic response and for its maximum value are provided. Two dynamic factors are discussed: the Dynamic Amplification Factor, function of the non-dimensional speed parameter and of the structural damping ratio, and the Transition Deamplification Factor, function of the sole ratio between the two non-dimensional parameters. The influence of the involved parameters on the dynamic amplification is discussed within a general framework. The proposed procedure appears effective also in assessing the maximum response of real bridges characterized by numerically-estimated mode shapes, without requiring burdensome step-by-step dynamic analyses.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.31 no.4
• /
• pp.58-71
• /
• 1989

This study aims to develop a computerized program for analysis of the ground-supported cylindrical shell structure with step varied section and to find out its mechanical characteri- stics through application of the developed program to the analysis of a ensiled farm silo as a model structure. The thickness of wall and bottom-plate of farm silo is assumed to be step-varied and its detailed structural dimensions are presented in Tab. 1 and 2. Several numerical case studies show that sectional stresses of the sample structures are largely reduced by adopting "varied section" design technique. And, other major results ob- tained from this study are summarize4 as follows ; 1. The variation of wall-thickness has a great influence on bending stresses of wall. Ho- wever, the larger the relative thickness of bottom-plate is, the smaller the influence is. 2. The magnitude of thickness of projecting toe of bottom-plate has negligible effect on sectional stresses 3. The conventional design methodology, which assumes the bottom edge of wall as clam- ped on ground, is proved to be discarded through the numerical analysis. 4. It is found that the "varied section" design technique should get similar effects as in the case of thick bott6m-plate having uniform thickness. 5. The variation of wall-thickness has a considerable effect on the bending stresses of bo- ttom-plate. Especially, this phenomenon is very remarkable in its projecting toe. In some cases. the negative bending moment may be acted on.

• Wind and Structures
• /
• v.15 no.3
• /
• pp.189-208
• /
• 2012

Lock-in and drag amplification phenomena are studied for a flexible cantilever using a simplified fluid-structure interaction approach. Instead of solving the 3D domain, a simplified setup is devised, in which 2D flow problems are solved on a number of planes parallel to the wind direction and transversal to the structure. On such planes, the incompressible Navier-Stokes equations are solved to estimate the fluid action at different positions of the line-like structure. The fluid flow on each plane is coupled with the structural deformation at the corresponding position, affecting the dynamic behaviour of the system. An Arbitrary Lagrangian-Eulerian (ALE) approach is used to take in account the deformation of the domain, and a fractional-step scheme is used to solve the fluid field. The stabilization of incompressibility and convection is achieved through orthogonal quasi-static subscales, an approach that is believed to provide a first step towards turbulence modelling. In order to model the structural problem, a special one-dimensional element for thin walled cross-section beam is implemented. The standard second-order Bossak method is used for the time integration of the structural problem.

• Convergence Security Journal
• /
• v.15 no.3_1
• /
• pp.23-30
• /
• 2015

Integrated Logistics Support can effectively respond to future wars and through the smooth logistics support activities bring a win in wars. Future warfare is very complex compare to Modern Warfare and required high level of strategies and tactics. Also, it is expected that the future war will be high-intensity war using high-tech weapon systems. Therefore, in this study, I look forward to the effective logistic support through the development of ammunition integrated logistics support which is a part of integrated logistics support(ILS). In addition, by studying a step-by-step system and supporting element of ammunition integrated logistics support, we can find the errors related to ammunition integrated logistics support system and suggest the direction to improve the system.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.33 no.2 s.109
• /
• pp.111-121
• /
• 2005

The Seoul Housing Corporation pronounced an alternative design competition and a bidding for Eunpyeong New Town in December of 2004. At first many construction companies were interested in the first New Town Project. But at last a few companies had proposed the alternative design and construction cost. This project needed a conjunction of design ideas and technology know-hows. And the client wanted the brand power of construction company. Ultimately the Corporation hoped that the first New Town Project will end up with high quality successfully. This competition had started with the original construction drawings. Then it needed some alternative ideas and the lowest cost. There were two drawings of non changeable part and changeable part. Non changeable parts are structure like housing unit plan, underground parking lots. Changeable parts are outdoor layout, interior design and building facade. So we tried all ideas of landscape technology and design principles within limited guidelines. The author applied new technology like tilted rooftop greening and sustained container greening on high-rise apartment house. This green technology will be the first trial in Seoul and in the world as well. Daewoo Corporation have accumulated greening technology through the researches by national funding since 2002. Through this New Town Project the green technology will go forward step by step.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.998-1007
• /
• 2006

In former times, It is obvious that the earth retaining cantilever wall using stabilizing piles is definitely superior to the other methods due to economical efficiency and the efficiency of construction through model tests using a soil tank and practical application(Kim, 2006). However, this method was not proved in theoretical basis from the viewpoint of geotechnical engineering. Accordingly, a variety of model experiments in order to analyze the behavior of the earth retaining cantilever wall and stabilizing piles according to excavation step and earth pressure and stress acting on stabilizing piles according to excavation step were performed. On the basis of analyzing the result of model tests using a soil tank, this study suggests failure mechanism of clods and a method calculating virtual supported point. In addition, this study contributes to developing the analyzing method of retaining piles, stabilizing piles and beams connecting two piles and, this study helps this method to be established as a new design method through analyzing the results of model tests using a soil tank.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.137-138
• /
• 2011

Mainly in construction liens to four contractors do not receive your order is caused by construction. This construction does not receive construction compunction to protect the contractor, I guess. On the other hand, the medium and small construction companies and contractors that could threaten the order four can be a problem. In this study, small construction companies to the lien of the lien claim on the issue of case studies have looked for the study. Small construction companies, in your case through the litigation between the lien of the lien litigation perspective, the cause of four orders after the analysis step by step construction was listed in chronological order. Identifying problem was the result of a lien. This study to previous studies regarding the lien on the issue through case studies of one kind of lien was derived for the problem. A follow-up studies and more case studies and interviews are considered necessary in the study.

• Journal of the Korean Data and Information Science Society
• /
• v.24 no.3
• /
• pp.593-601
• /
• 2013

We often need to include categorial variables as explanatory variables in regression models. The categorial variables in regression models can be quantified through dummy variables. In this study, we provide an education tool using Excel VBA for displaying regression lines along with test results for regression models with a continuous explanatory variable and one or two categorical explanatory variables. The regression lines with test results are provided step by step for the model(s) with interaction(s), the model(s) without interaction(s) but with dummy variables, and the model without dummy variable(s). With this tool, we can easily understand the meaning of dummy variables and interaction effect through graphics and further decide which model is more suited to the data on hand.

• Proceedings of the Korea Contents Association Conference
• /
• 2005.11a
• /
• pp.470-474
• /
• 2005

This paper uses the morphing of an implicit primitives to Deformation of a 3D Character, Unlike existing a 3D Deformation method, We try to propose the method to express efficiently a deformation step of the character through to modify a parameter value of an implicit primitives. The corresponding point of an each character can produce automatically uses the 3D coordinate about a center point of the primitive which organizes the character. A character coordinate among frames can produce medium through the between. A character deformation method to be proposed can be utilized efficiently for a growth step simulation of plants and animals.

• Journal of Korea Multimedia Society
• /
• v.8 no.5
• /
• pp.715-720
• /
• 2005

In a software development process, it is necessary to have a method which verifies and satisfies users' requirements in their point of view. This allows the system developer to design a high qualify software system and have it developed and used in an effective way since users' requirements have well been shown through it. In this paper, we propose the RV-UI model system that can verify users' requirements a step ahead of system implementation step. This RV-UI model system has standardized user interface which is in practical use into functional model for each process and it is designed to satisfy users' requirements and manage configuration of them through the interface which has the Kano model.