• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.554-559
• /
• 1999

The purpose of this study is the machining of texture shapes by the contour fitting data. The hardware of the system comprises PC and scanning system, CO2 laser machine. There are four steps, (1) text image loading using scanning shapes or 2D image files, (2) generation of contour fitting data by the line and arc, cubic Bezier curve, (3) generation of NC code from the contouring fitting data, (4) machining by the DNC system. It is developed a software package, with which can conduct a micro CAM system of CNC laser machine in the PC without economical burden.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.4
• /
• pp.158-164
• /
• 2003

The suspension system of cars is composed of dampers and springs, which usually have nonlinear characteristics. The nonlinear characteristics make the differences in the results of analytical models and experiments. In this study, the nonlinear system identification method which does not assume a special form for nonlinear dynamic systems and minimize the error by calculating the error reduction ratio is devised to estimate the nonlinear parameters of the suspension system of an EF-SONATA car from the field running test data. The results show that the spring has a cubic nonlinear term and the damper has a coupled nonlinear term. Also, the numerical results with the estimated nonlinear parameters agree well with the field test data for the different running speeds.

• Journal of the Korean Ceramic Society
• /
• v.30 no.9
• /
• pp.723-730
• /
• 1993

The mechanism of formation of perovskite phase and the dielectric properties of PZMN[Pb(Zn, Mg)1/3Nb2/3O3] ceramics were examined using two different types of the columbite precursors, (Mg, Zn)Nb2O6 (MZN) and MgNb2O6＋ZnNb2O6 (MN＋ZN). The formatin of perovskite phase in PbO＋MN＋ZN system is characterized by an initial rapid formation of Mg-rich perovskite phase, followed by a sluggish formation of Zn-rich perovskite phase. On the other hand, thepyrochlore/perovskite transformation in the PbO＋MZN system proceeded uniformly with a spatial homogeneity. The degree of diffuseness of the rhombohedral/cubic phase transitionis higher in the PbO＋MN＋ZN system than in the PbO＋MZN specimen, indicating a broadened compositional distributjion of the B-site catons (Nb+5, Zn+2, Mg+2) in the PbO＋MN＋ZN system.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.170.5-170
• /
• 2001

As close competitions are being fought out among enterprises, they should accomplish their objectives such as reduction of cost, improvement of quality and condensation of due date, etc. For this objects, it becomes very important to manage the workflow harmoniously and to share the information efficiently between geographically dispersed users. We developed the collaborative design system, which manages various design process and enables to share design information. In this paper, Internal-based collaboration system for press die design process in the automobile manufacturer is developed with CORBA, Java and relational database system. After modeling real press die design process with UML language, workflow routing path is created by modeling data. Cost and time for ...

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.25-29
• /
• 1997

In this thesis, we construct the microrobot succor system and navigate the real-time path planning and visual tracking of each robot. The system consists robots, vision system and a host computer. Because the robots are free-ranging mobile robot, it is needed to make and gallow the path. The path is planned and controlled by a host computer, ie. Supervisory control system. In path planning, we suggest a cost function which consists of three terms. One is the smoothness of the path, another is the total distance or time, and the last one is to avoid obstacles. To minimize the cost function, we choose the parametric cubic spline and update the coefficients in real time. We perform the simulation for the path planing and obstacle avoidance and real experiment for visual tracking

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.3
• /
• pp.303-311
• /
• 1998

We developed a pattern drafting computer program using a popular CAD program for the purpose of the automatic manufacturing and education based on the concept of the easy -order-system which can easily reflect body characteristics and design favors of individuals to the ready-made clothing. The programs were written in Auto LISP which can utilise most of frictions of the Auto CAD, and the result of the design for an full-pleated skirt was shown. Also, we devised an easy way to set the location of reference points by inputting of tangential angle only for the use of the cubic spline curve which can represent body shape very well. Finally, by marking down all of symbols needed in manufacturing process, we completed the automatic pattern drafting program to make it useful as an industrial pattern without any amendment or correction in cutting and sewing operation.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.74-77
• /
• 2007

In this paper, we propose a system which can display panoramic-stereopic image for tele-operating excavator. the system was implemented by using center-viewpoint corresponding algorithm and image mosaic process. We could obtain remarkable result from the survey among the ex-pert of excavator. We also design a control station with RF transfer module, H.264 codec module and suggested algorithm. Especially, our system shows a superb performance on cubic effect and presence sense of a field of excavating work.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.76-78
• /
• 1993

This paper describes an efficient method of computing any desired number of the most unstable eigenvalues and eigenvectors of a large scale multi-machine power system. Approximate eigenvalues obtained by Hessenberg process are refined using Rayleigh quotient iteration with cubic convergence property. If further eigenvalues and eigenvectors are needed, the procedure described above are repeated with deflation. The proposed algorithm can cover all the model types of synchronous machines, exciters, speed governing system and PSS defined in AESOPS. The proposed algorithm applied to New England test system with 10 machines and 39 buses produced the results same with AESOPS in faster computation time. Also eigenvectors computed in Rayleigh quotient iteration makes it possible to make eigen-analysis for improving unstable modes.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.617-620
• /
• 1997

We have built a robot soccer system to participate in MIROSOT97. This paper represents hardware specification of our system and our strategy. We select a centralized on-line system for a soccer game. The paper explains hardware specifications of our system for later development. Also, the paper explains our strategy from two viewpoints. From the viewpoint of cooperation, some heuristic ideas are implemented. From the viewpoint of path plan, Cubic spline is used with cost function which minimized time, radius of curvature for smoothness, and obstacle potential field. Direct comparison will be realized in MIROSOT97.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.3
• /
• pp.669-678
• /
• 1994

The BOD removal characteristics of submerged biofilters filled with three kinds of filter media respectively were experimentally examined with constant temperature, pH value and variable BOD loading and recirculation ratio. Obtained results are as follows; 1. The BOD removal ratio decreases with the increasing $BOD_5$ volumetric loading rate, and the loading rate for the BOD removal over 90% is lower thean $1.6kg{\cdot}BOD_5/m^3{\cdot}d$ for the plastic media of Netring and cubic wire meshes. This is a much large value than $0.3{\sim}0.8kg{\cdot}BOD_5/m^3{\cdot}d$ for conventional activated sludge process. The required submerged biofilter volume is found to be much samller than that of conventional activated sludge process. 2. The decreasing order of BOD removal is Netring (random plastic media), cubic wire meshes (plastic module), and then gravel (stone media). This is mainly due to the media characteristics such as void ratio, specific surface area and media shapes. 3. The $BOD_5$ removal rate increases with the recircuration ration, but the rate of increases becomes samaller as the recirculation ratio increases over 20. When $BOD_5$ loading is $1.8kg{\cdot}BOD_5/m^3{\cdot}d$, the required recirculation rationto obtain 90% $BOD_5$ removal is about 20 for Netring and it was about 30 for cubic wire meshes. 4. Reynold's Number increases with recirculation ratio, and the Reynold's Numbers corresponding to the recircuration ratio of 10~50 are less than 52, showing laminar up flows in the filter. The settled and effluent sludges increase with increase of Reynol's Number, and there are the definite Reynold's Numbers at which the settling sludge concentrations become nearly constant respectively in each filters. 5. In this submerged biofilter system, small volume of sludge hopper can be substituted for a separated settling tank.