• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.378-381
• /
• 2003

Efficient development of method on a performance evaluation for machine tools has been regarded as the most important work for accuracy and quality enhancement to every user and manufacturer. A evaluation method of accuracy for machine tools has been studied recently according to the rapid increase of interest in precision machine tools. To this point of view, the circular interpolation test of machine tools is recognized as the most useful method to distinguish a dynamic accuracy of NC machine tools by ISO and ANSI/ASME, etc. In this paper, we have studied and developed the form measurement system with grid encoder to analyse the final accuracy of NC machine tools. we have analyzed the servo system error and geometric error of NC machine tools through measuring a dynamic error signal by this system. and then we verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematic ball-bar system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.03a
• /
• pp.148-153
• /
• 1998

In order to control thermal deformation of machine origin of machine tools due to internal and external heat sources, the real-time compensation system has been developed. First, GMDH models were constructed to estimate thermal deformation of machine origin for a vertical machining center through the measurement of deformation data and temperature data of specific points on the machine tool. Thermocouples and gap sensors are used respectively for measurement. These models are nonlinear equations with high-order polynomials and implemented in a multilayered perceptron type network structure. Secondly, work origin shift method were developed by implementing digital I/O interface board between CNC controller and IBM-PC. The work origin shift method is to shift the work origin by the compensation amounts which is calculated by pre-established GMDH model. From the experimental result, thermal deformation of machine origin was reduced to below $\pm$5${\mu}{\textrm}{m}$.

• Journal of Advanced Navigation Technology
• /
• v.18 no.1
• /
• pp.74-77
• /
• 2014

This paper suggested an error control for multi-channel running on machine to machine environment. This system is suitable for recovering software fault for multimedia CSCW(Computer Supported Cooperative Works) based on machine to machine environment. It is necessary for the system to be protected by reactivity of media service instance instead of breaking process of session. This paper explains a performance analysis of an error recovery system of M2M based computing collaboration environment using rule-based DEVS modeling and simulation techniques.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1852-1857
• /
• 2003

This study is concerned about the development of three-dimensional bending machine for heat exchanger. Recently, three-dimensional bending is required for various heat exchanger. The purpose of this study is design of three-dimensional bending machine by analysis of bending process and structural analysis simulation. The analysis is carried out by FEM simulation using DEFORM and CATIA V5 software. The copper-tube is modeled by shell elements and the machine is modeled by placing proper shell and solid finite elements and fictitious mass properties to represent the real one. The final results of analysis are applied to the design of three-dimensional bending machine and the machine is successfully developed.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.2
• /
• pp.208-214
• /
• 2008

This paper presents a structural modification for the performance improvement of a grain sorting machine. The grain sorting machine is used to sort abnormal grains from normal grains such as rice or wheat. Vibration is one of main causes to deteriorate the sorting performance of the machine. Based on the finite element analysis and the experimental modal testing, the vibration characteristics were investigated for the sorting machine. Furthermore, in order to improve the sorting performance of the machine, the frame, chute and base plate of the sorting machine were modified by using the results of the vibration analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.778-783
• /
• 1994

In operating automated manufacturing system, the long term stability and reliability of NC machine tools become most critical issues. Especially the machining accuracy is dominated by the thermal deformation of machine tools which remains still unsolved and causes troubles in manufacturing operations. Although researches have been carried out on the thermal behavior of a machine tools to minimize or control the thermal deformation of machine tools, the computer models for an analysis of the thermal behacior in machine tools has yet to appear in the open literature. The object of the paper is to present a method of modeling the thermal behavior of a machine tool. The method will make use of finite elements ad be capable of modeling whole machine structures as well as of heat generation processes in the kinematic system components. And temperature distributions and thermal deformations of a CNC lathe are analyzed using the finite element method and are compared with those measured in practice.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.20-25
• /
• 2000

In this paper, a methodology of geometrical error identification and compensation for NC machine tool position. We have proposed a reference artifact with which, in measuring the coordinate system of NC machine, the robust coordinate systems are given. The coordinate system of the NC machine could be compensated successfully with the information obtained by measuring the reference artifact and our compensation algorithm. Monte Carlo simulation is used to evaluate coordinate referencing ability and, the uncertainties of the machine tool position is estimated and observed through the compensation process by simulation.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.5
• /
• pp.59-65
• /
• 1998

In order to utilize the information of well-know grinding database or grinding machine characteristics, a database needs to be designed by considering the delicate property of the machine tools for the high precision and quality of the demanding specification. Among the machine tools for the high precision and quality of the demanding specification. Among the machine tools, machining conditions of the grinding are various and knowledge repeatance obtained form the grinding process are less credable. therefore it is desirable for database, which is used to set the grinding conditions, to utilize the maximum machine tool capability. The present paper studied on the occurance limit of chatter vibration and burn considering the characteristics of machine tool. And also basic experiments were performed to establish the optimum grinding conditions which could maximize the grinding efficiency.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.10
• /
• pp.101-107
• /
• 2017

In this paper, we study the problem of parallel machine scheduling considering the moving time of multiple servers. The parallel machine scheduling is to assign jobs to parallel machines so that the total completion time(makespan) is minimized. Each job has a setup phase, a processing phase and a removal phase. A processing phase is performed by a parallel machine alone while a setup phase and a removal phase are performed by both a server and a parallel machine simultaneously. A server is needed to move to a parallel machine for a setup phase and a removal phase. But previous researches have been done under the assumption that the server moving time is zero. In this study we have proposed an efficient algorithm for the problem of parallel machine scheduling considering multiple server moving time. We also have investigated experimentally how the number of servers and the server moving time affect the total completion time.

• The Research Journal of the Costume Culture
• /
• v.13 no.2 s.55
• /
• pp.189-199
• /
• 2005

The purposes of this study are to see a manufacturing process on knit by comparison, and to present whole garment knitting machine different from the traditional method of the production by using the whole garment system. The characteristics of each stage were examined through SDS-one, Shimaseiki Design CAD System and the whole garment knitting machine. The whole garment knitting machine as a method of composing a suit of knitting product is a way of making creative knitting fashion, which also can be used as a basic material for the further study on the whole garment knitting machine. Eventually, it is expected that this machine can satisfy the knit wearers' various needs by showing more useful method to knit designers.