• Architectural research
• /
• v.14 no.3
• /
• pp.109-116
• /
• 2012

In order to shorten construction duration in high-rise project, construction company tried to make various system method toward simplifying construction method and shortening construction duration. Though high-rise tower-type residential project are growing, there are few case study. Then, the data for preliminary schedule planning in high-rise tower-type residential project are rare. This purpose of research shows construction method in structural work in high-rise tower-type residential project, suggests schedule planning in structural work through case studies. The structural work in high-rise tower-type residential project was divided 1) completion of form in lower part and 2) the typical floor under penthouse. The statistical analysis were done in two parts, the data from analysis were used in simulation. Finally, researcher confirmed the difference between real construction duration and the figure from simulation. The results shows that the more construction duration is long, the less ACS's cost is low. It means the effectiveness is increasing in ACS, if the floor number is high.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.1
• /
• pp.12-18
• /
• 1999

A deformable non-Uniform Rational B-Spline (NURBS) based volume is programed for the force reflecting exoskeleton haptic device. In this work, a direct free form deformation (DFFD) technique is applied for the realistic manipulation. In order to implement the real-time deformation, a nodal mapping technique is used to connect points on the virtual object with the NURBS volume. This geometric modeling technique is ideally incorporated with the force reflecting haptic device as a virtual interface. The results in this work introduce details for the complete set-up for the realistic virtual clay modeling task with force feedback. The force reflecting exoskeleton haptic manipulator, coupled with a supporting PUMA 560 manipulator and the virtual clay model are integrated with the graphics display, and results show that the force feedback from the realistic physically based virtual environment can greately enhance the sense of immersion.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.2
• /
• pp.9-16
• /
• 2004

Because a generated heat during grinding operation makes a serious deformation on a ground surface as a convex form, a real depth of cut in deformed zone has larger than an ideal depth of cut. Consequently, the ground surface has a geometric error as a concave form after cooling the workpiece. In this study, the force and the geometric error of surface grinding were examined. From evaluating magnitude and mode of the geometric error according to grinding conditions, an optimal grinding condition was proposed to minimize the geometric error. In addiction the relationship between the geometric error and the grinding force was found out. Due to least square regression it was able to predict the geometric error by using the grinding force.

• Journal of Korea Society of Industrial Information Systems
• /
• v.1 no.1
• /
• pp.203-217
• /
• 1996

This paper is to describe the development of nesting software for the materials cutting plan of footwear manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus, thepattern nesting by worker's experience for materials cutting is different form the real cutting results and also different form the error size of yield in degree of worker's skill. Recently, a few of domestic shoes' makers make use of oversee's nesting software.But the nesting software unfits for the domestic actual circumstances , and is complex to use , and is expensive , and is not to be interfaced with the auto cutting machine. Therefore , we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances, which can synchronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility. The architecture of system, the function of each module, and the information processing proceduresof each function are discussed.

• Smart Structures and Systems
• /
• v.15 no.5
• /
• pp.1203-1214
• /
• 2015

This paper deals with the experimental validation of the use of PVDF Patches for the assessment of spatial derivatives of displacement field. It focuses more exactly on the shear Force Identification by using Specific forms of PVDF patcHes (FISH) on beams. An overview of the theoretical approach is exposed. The principle is based on the use of the weak form of the equation of motion of the beam which allows the shear forces to be extracted at one edge of the sensor when this last has a specific form. The experimental validation is carried out with a cantilever steel beam, excited by a shaker at its free boundary. The validation consists in comparing the shear force measured by the designed sensor glued at the free edge and the directly measured force applied by the shaker. The sensor is made of two patches, called the "stiffness" patch and the "mass" patch. The use of both patches allows one to identify correctly the shear force on a large frequency domain. The use of only the stiffness patch is valid in the low frequency domain and has the advantage to have a frequency-independent gain that allows its use in real time.

• Journal of the Chungcheong Mathematical Society
• /
• v.25 no.1
• /
• pp.19-25
• /
• 2012

The purpose of this paper is to derive powers $A^{n}$ using a system of recursive sequences for a given $2{\times}2$ matrix A. Introducing a recursive sequence we have a quadratic equation. Solutions to this quadratic equation are related with eigenvalues of A. By solving this quadratic equation we can easily obtain an explicit form of $A^{n}$. Our method holds when A is defined not only on the real field but also on the complex field.

• Journal of Information Processing Systems
• /
• v.8 no.4
• /
• pp.713-720
• /
• 2012

Unlike FEM (Finite Element Method), which provides an accurate deformation of soft objects, FFD (Free Form Deformation) based methods have been widely used for a quick and responsive representation of deformable objects in real-time applications such as computer games, animations, or simulations. The FFD-AABB (Free Form Deformation Axis Aligned Bounding Box) algorithm was also suggested to address the collision handling problems between deformable objects at an interactive rate. This paper proposes an enhanced FFD-AABB algorithm to improve the frame rate of simulation by adding the bounding sphere based collision test between 3D deformable objects. We provide a comparative analysis with previous methods and the result of proposed method shows about an 85% performance improvement.

• The Korean Journal of Applied Statistics
• /
• v.25 no.6
• /
• pp.925-932
• /
• 2012

The article introduces a method to estimate a cointegrated vector autoregressive model, using mixed-frequency data, in terms of a state-space representation of the vector error correction(VECM) of the model. The method directly estimates the parameters of the model, in a state-space form of its VECM representation, using the available data in its mixed-frequency form. Then it allows one to compute in-sample smoothed estimates and out-of-sample forecasts at their high-frequency intervals using the estimated model. The method is applied to a mixed-frequency data set that consists of the quarterly real gross domestic product and three monthly coincident indicators. The result shows that the method produces accurate smoothed and forecasted estimates in comparison to a method based on single-frequency data.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.11
• /
• pp.180-188
• /
• 1998

Z-map is a special form of discrete nonparametric representation in which the height values at grid points on the xy-plane are stored as a 2D array z[i.j]. While z-map is the simplest form of representing sculptured surfaces and it is the most versatile scheme for modeling nonparametric objects, its practical application in industry (eg, tool-path generation) aroused much controversy over its weaknesses ; accuracy, singularity (eg, vertical wall), and some excessive storage needs. Although z-map has such limitations, much research on the application of z-map can be found in various articles. However, research on the systematic analysis of sculptured surface shape representation via z-map model is rather rare. Presented in this paper are the following: shape modeling power of the simple z-map model, exact (within tolerance) B-map representation of sculptured surfaces which have some feature-shapes such as vertical-walls and real sharp-edges by adopting some complementary B-map models, and some application examples.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.781-785
• /
• 2005

Cutting forces and tool deflection in end milling are represented as the closed form of tool rotational angle and cutting conditions. The discrete cutting forces caused by tool entry and exit are continued using the Fourier series expansion. Tool deflection is predicted by direct integration of the distributed loads on cutting edges. Cutting conditions, tool geometry, run-outs and the stiffness of tool clamping pan are considered for cutting forces and tool deflection estimation. Compared to numerical methods, the presented method has advantages in short prediction time and the effects of feeding and run-outs on cutting forces and tool deflection can be analyzed quantitatively. This research can be effectively used in real time machining error estimation and cutting condition selection for error minimization since the ferm accuracy is easily predicted by tool deflect ion curve.