• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.1
• /
• pp.9-14
• /
• 2006

This paper presents methods of robot localization using recent radio frequency identification technology. If the absolute position and orientation of a tag are given in an indoor environment where RFID tags are installed, a robot can estimate its location using the relationship of the identified tag and the robot in a relative coordinate. To derive this relationship, we propose three estimation techniques using a model of a RFID reader, the direction of identification and the detection range. In this algorithm, a suitable estimation method is selected out of the three proposed techniques depending on the situations and trajectory of robot in the detection range. Simulation and experimental results show that the proposed methods can provide good performance for localization.

• 유체기계공업학회:학술대회논문집
• /
• 1999.12a
• /
• pp.163-169
• /
• 1999

The numerical procedure has been developed for simulating incompressible viscous flow around a turbine stage with rotor-stator interaction. This study solves 2-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system. The Marker-and-Cell concept is applied to efficiently solve continuity equation. To impose an accurate boundary condition, O-H multiblocked grid system is generated. O-type grid and H-type grid is generated near and outer rotor-stator The cubic-spline interpolation is applied to handle a relative motion of a rotor to the stator. Turbulent flows have been modeled by the Baldwin- Lomax turbulent model. To validate present procedure, the time averaged pressure coefficients around the rotor and stator are compared with experiment and a good agreement obtained.

• The KSFM Journal of Fluid Machinery
• /
• v.18 no.1
• /
• pp.44-50
• /
• 2015

Labyrinth seals are commonly used in various kinds of turbomachinery to reduce leakage flow. In the present 3D CFD analysis of see-through-type labyrinth air seal, the methodology of determining leakage and rotordynamic coefficients is suggested with the relative coordinate system for steady-state simulation. The leakage flow and rotordynamic forces predicted by using different solvers and turbulent models of FLUENT are compared with the results of the existing bulk-flow analysis code LABYSEAL.FOR and experiment. The present CFD result of direct stiffness(K) shows only improvement in prediction. The results of leakage and rotordynamic coefficients as well as computing time are sensitive against the used solver and turbulent model.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.7 no.3
• /
• pp.216-220
• /
• 2007

Camera calibration in machine vision is the process of determining the intrinsic camera parameters and the three-dimensional (3D) position and orientation of the camera frame relative to a certain world coordinate system. On the other hand, Takagi-Sugeno-Kang (TSK) fuzzy system is a very popular fuzzy system and approximates any nonlinear function to arbitrary accuracy with only a small number of fuzzy rules. It demonstrates not only nonlinear behavior but also transparent structure. In this paper, we present a novel and simple technique for camera calibration for machine vision using TSK fuzzy model. The proposed method divides the world into some regions according to camera view and uses the clustered 3D geometric knowledge. TSK fuzzy system is employed to estimate the camera parameters by combining partial information into complete 3D information. The experiments are performed to verify the proposed camera calibration.

• Bulletin of the Korean Chemical Society
• /
• v.7 no.5
• /
• pp.391-395
• /
• 1986

MNDO calculations were carried out to determine reactant complexes and transition states of the $S_N2$ reactions of $CH_3X\;+\;Y^-\;{\to}\;CH_3Y\;+\;X^-$ where X = F, Cl, CN and Y = CN, OH, F, Cl. The leaving group ability was found to vary inversely with the activation barrier, which in turn was mainly ascribable to the deformation energies accompanied with bond stretching of C-X bond and inversion of $CH_3$ group. The nucleophilicity was shown to be in the order $Cl^->F^->OH^->CN^-$ but the effect on the activation barrier was relatively small compared with that of the leaving group. The bond breaking and bond formation indices and energy decomposition analysis showed that the TS for the reaction of $CH_3$Cl occurs in the early stage of the reaction coordinate relative to that of $CH_3$F. It has been shown that the potential energy surface (PES) diagrams approach can only accommodate thermodynamic effects but fails to correlate intrinsic kinetic effects on the TS structure.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.6
• /
• pp.19-26
• /
• 2021

The lattice structure is attracting attention from industry because of its excellent strength and stiffness, ultra-lightweight, and energy absorption capability. Despite these advantages, widespread commercialization is limited by the difficult manufacturing processes for complex shapes. Additive manufacturing is attracting attention as an optimal technology for manufacturing lattice structures as a technology capable of fabricating complex geometric shapes. In this study, a unit cell was formed using a three-dimensional coordinate method. The relative density relational equation according to the boundary box size and strut radius of the unit cell was derived. Simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) with a controlled relative density were designed using modeling software. The accuracy of the equations for calculating the relative density proposed in this study secured 98.3%, 98.6%, and 96.2% reliability in SC, BCC, and FCC, respectively. A simulation of the lattice structure revealed an increase in compressive yield load with increasing relative density under the same cell arrangement condition. The compressive yield load decreased in the order of SC, BCC, and FCC under the same arrangement conditions. Finally, structural optimization for the compressive load of a 20 mm × 20 mm × 20 mm structure was possible by configuring the SC unit cells in a 3 × 3 × 3 array.

• The Journal of Engineering Geology
• /
• v.33 no.1
• /
• pp.189-200
• /
• 2023

As urbanization and industrialization increase development in downtown areas, damage due to ground settlement continues to occur. Building collapse in urban has a high risk of leading to large-scale damage to life and property. However, there has rarely been studied on measurement data analysis methods when uneven loads are applied to the excavated ground and no prior knowledge of the ground. Accordingly, it was attempted to analyze the relative settlement behavior and correlation by processing the time-series surface settlement of construction sites in the urban. In this paper, the average index of difference in settlement and average of relative difference in settlement are defined and calculated, then plotted in the coordinate system to analyze the relative settlement behavior over time. In addition, since there was no prior knowledge of the ground, a standard to classify the clusters was needed, and the observation points were classified into using k-means clustering and Dunn Index. As a result of the analysis, it was confirmed that all the clusters moved to the stable region as the settlement amount converges. The clusters were segmented. Based on the analysis results, it was possible to distinguish between the independent displacement area and same behavior area by analyzing the correlation between measurement points. If possible to analyze the relative settlement behavior between the stations and classify the behavior areas, it can be helpful in settlement and stability management, such as uplift of the surrounding area, prediction of ground failure area, and prevention of activity failure.

• Journal of Internet Computing and Services
• /
• v.15 no.3
• /
• pp.11-19
• /
• 2014

The natural user interface/experience (NUI/NUX) is used for the natural motion interface without using device or tool such as mice, keyboards, pens and markers. Up to now, typical motion recognition methods used markers to receive coordinate input values of each marker as relative data and to store each coordinate value into the database. But, to recognize accurate motion, more markers are needed and much time is taken in attaching makers and processing the data. Also, as NUI/NUX framework being developed except for the most important intuition, problems for use arise and are forced for users to learn many NUI/NUX framework usages. To compensate for this problem in this paper, we didn't use markers and implemented for anyone to handle it. Also, we designed multi-modal NUI/NUX framework controlling voice, body motion, and facial expression simultaneously, and proposed a new algorithm of mouse operation by recognizing intuitive hand gesture and mapping it on the monitor. We implement it for user to handle the "hand mouse" operation easily and intuitively.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.808-812
• /
• 2003

We need a lot of manpower and we can cut down a labor cost by applying industrial robots the footwear bonding automation process. In this study, we suggest how to program off-line robot path along a shoe's outsole shape in the footwear bonding process by 5-axis microscribe system like robot arms. This microscribe system development consists 5-axis microscribe mechanics, signal processing circuit, and PC with software. It is the system for making database of a shoe's outsole through the movement of a microscribe with many joints. To do this, first read 5-encoders' pulse values while a robot arm points a shoe's outsole shape from the initial status. Then, calculate a relative shoe's outsole by Denavit-Hatenberg's (D-H) direct Kinematics of known length of links and coordinate values. Next, calculate the encoders' pulse values of the robot arm's rotation and transmitting the angle pulse values to the PC through a circuit. Finally, it is able to display a shoe's outsole at real-time by computing the Denvavit-Hantenberg's (D-H) direct kinematics in the PC. With the coordinate values calculated above, we can draw a bonding gauge-line on the upper. Also, we can make off-line robot path programming compute a shoe's bonding area on the upper. These results will be effectively applied for programming a robot path on off-line and automatically.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.3
• /
• pp.358-374
• /
• 1999

This study measured the relative displacements of the five-unit fixed partial dentures as cast with the same fixed partial dentures sectioned and assembled by investment-soldering, solder-ing stand-soldering, and cast-joining techniques A total of fifteen specimens using a type IV gold alloy were one-piece cast as control and then sectioned and assembled five test specimens for each method were prepared. A computerized three dimensional coordinate measuring machine and specially designed cylinder for this study were used. Displacement was defined by six displacement variables for the each of cylinders incorporated in each casting: three component displacements(${\Delta}Lx,\;{\Delta}Ly,\;and\;{\Delta}Lz$) and rotational displacements(${\Delta}{\theta}x,\;{\Delta}{\theta}y,\;{\Delta}{\theta}z$). The global displacement was computed using the mathematical formula ${\Delta}R$ = Global displacement =$\sqrt{{(x'-x)}^2+{(y'-y)}^2+{(z'-z)}^2}$ Under the conditions of this study, the following conclusions were drawn: 1. The investment-soldering group showed the largest mean value of final global displacements, followed by stand-soldering group, cast-joining group and one-piece cast group. However, between the mean values of final global displacement for the cast-joining group and one-piece cast group, there was no significant difference. 2. For investment-soldering and stand-soldering groups, the greater global displacements were recorded in soldering phase than in indexing or investing phase. 3. For one-piece cast group, the displacements occured mostly in the casting phase. And for cast-joining group, there was no significant difference in global displacements among the fabricating procedures. 4. Intercentroidal distance decreased in framework-patterning, solder-indexing, solder-standing, and soldering phases, but increased in investment block-investing and casting phases. 5 Specially designed cylinder for touch-trigger type coordinate measuring machine was validated.