• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.228-232
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• 1992

The integrated management system IMMC system) is developed for machining, measuring and checking by using IBM-PC under Borland C $\^$++/ environment. MMC system consists of following systems : DNC system, MascMC system (for measuring and checking) and MascCAM system : DNC system, MascNC system (for measuring and checking) and MascCAM system (for CAM). And some other modules support MMC system for practical usages. A vertical machining center equipped with FANUC 0MC is used for experiments. Feasibility of the system is confirmed by a large amount of experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.194-201
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• 1991

일반적으로 금형공업은 전형적인 중소기업형 공업으로 계획생산보다는 주문 생산방식으로 운영되고 있으며 부가 가치가 높은 산업이다. 또한 업태가 다양하고 산업구조의 선진화에 비례하여 기업체 수가 증가하는 추세이며 고정밀도, 고숙련도를 요하는 고도의 기술 집약적 산업이다. 정밀도의 향상, 인력절감, 자동화와 함께 금형 공장내의 제한된 자원을 효율적으로 이용하고 공장자동화를 촉진하기 위한 각 부문별 자동화 시스템, 컴퓨터 시스템을 정보 Network 로 접속해 공장내 제반관련자료를 유효하게 활용할 수 있는 Total System으로서의 공장운영 시스템의 도입ㆍ필요성이 대두되고 있다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.307-311
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• 1992

종래의 DNC(Direct Numerical Control)에서 가공 Cell의 효율을 높이기 위한 분산 제어 DNC(Distributed Numerical Control)시스템 운용을 위해서는, 운용에 필요한 소프트웨어 외에 공작기계 및 주변기계에 대한 실시간 감시/제어 기능을 가져야 한다. 이를 위해 당 연구실에서는 경제성 및 확장성을 고려 범용 PLC (Programable Logic Controller)와 각 공작기계 및 주변기기를 연결하고, PC(Personal Computer)와 다자간 및 고속 통신이 가능한 전용 통신회선을 이용한 경제성 있는 실시간 가공 Cell 감시/제어시스템 RT-COMOS(Real Time Machine Cell Control and Monitoring System)를 개발했다. 본 논문에서는 이에 대한 연구결과를 소개한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2286-2293
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• 1993

The study presents the development of a cost-effective CAD/CAM system for metal moulds by use of personal computer. In the personal CAD/CAM system named DKSYS, metal moulds are defined by the operations of basic elements such as prism, pyramid and sphere, plane, rotational body, and surface elements including curved surface. The internal expression of shape elements in the computer is based on the wire model, which is a set of cross-sectional curves of the shape elements. With the addition of OMS system to CAD/CAM system the optimum cutting condition can be selected automatically. After programming NC information with the form definition and the optimum cutting condition, the metallic mould can be formed by transferring cutting information to CNC machine through DNC system. Using a computer for the above process, it is possible to increase the productivity and reduce the cost.

• Korean Journal of Computational Design and Engineering
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• v.1 no.2
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• pp.150-157
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• 1996

The hob is considered as an effective gear cutting tool for achieving the various gears such as spur gear, helical gear, worm gear and so on. To enhance the productivity and precision of hobs and the competitive ability of domestic CNC hob relieving lathes, a CAM system for CNC hob relieving lathe needs to be realized. In this study, the CAM system is developed based on the personal computer and C language. Besides the automatic generation of CNC data, the developed CAM system has the various capabilities related to the generation of tool path, the cutting simulation for verifying the generated CNC data and forecasting the cutting time, the DNC operation for communicating the CNC data with CNC controller by RS232C port, and the estimation of undercut length for verifying the hob cutting conditions.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.12
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• pp.19-29
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• 1995

The basic technology for a production system represented by design, machining, assembly, and inspection, is machining technology such as CNC machine tools. etc. Direct Numerical Control, that effeciently manages NC programs is developing into Distributed Numerical Control that increases the utilization of the machining cell. It has the ability of monitoring and control, in real time, for CNC and periperial equipment. In this study, we develop a Distributed Numerical Control system that has real time and multitasking operation capability for the machining cell with various CNC's. With the consideration of economy, generalization and extension, the system is interfaced with CNC machine tools and periperial device using RS-485 network and RS-232C communication methods.

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.312-318
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• 2000

In this study, an exclusive CAD/CAM system is developed for enhancing the effectiveness and productivity of CNC universal cylindrical grinding machines on which the external/facing/internal grinding cycles and the wheel dressing cycles are integratively carried out. The CAD/CAM system can manage the various processes such as geometry design, NC code generation, NC code verification, DNC operation, and so on. Especially, the feature-based modeling concept is introduced to improve the geometry design efficiency. And the NC code verification is realized by virtual manufacturing technique based on the real-time analysis of NC codes and the boolean operation between workpiece and wheel.

• Journal of the Korea Safety Management & Science
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• v.20 no.3
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• pp.11-19
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• 2018

This study suggests a model of production information system that can reduce manufacturing lead time and uniformize quality by using DNC S/W as a part of constructing production information management system in the industrial field of the existing marine engine block manufacturing companies. Under the effect of development of this system, the NC machine interface device can be installed in the control computer to obtain the quality information of the workpiece in real time so that the time to inspect the process quality and verify the product defect information can be reduced by more than 70%. In addition, the reliability of quality information has been improved and the external credibility has been improved. It took 30 minutes for operator to obtain, analyze and manage the quality information when the existing USB memory is used, but the communication between the NC controller computer and the NC controller in real time was completed to analyze the workpiece within 10 seconds.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5862-5887
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• 2019

In this paper, we propose a two-way relaying scheme using non-orthogonal multiple access (NOMA) technology. In this scheme, two sources transmit packets with each other under the assistance of the decode-and-forward (DF) relays, called as a TWDFNOMA protocol. The cooperative relays exploit successive interference cancellation (SIC) technique to decode sequentially the data packets from received summation signals, and then use the digital network coding (DNC) technique to encrypt received data from two sources. A max-min criterion of end-to-end signal-to-interference-plus-noise ratios (SINRs) is used to select a best relay in the proposed TWDFNOMA protocol. Outage probabilities are analyzed to achieve exact closed-form expressions and then, the system performance of the proposed TWDFNOMA protocol is evaluated by these probabilities. Simulation and analysis results discover that the system performance of the proposed TWDFNOMA protocol is improved when compared with a conventional three-timeslot two-way relaying scheme using DNC (denoted as a TWDNC protocol), a four-timeslot two-way relaying scheme without using DNC (denoted as a TWNDNC protocol) and a two-timeslot two-way relaying scheme with amplify-and-forward operations (denoted as a TWANC protocol). Particularly, the proposed TWDFNOMA protocol achieves best performances at two optimal locations of the best relay whereas the midpoint one is the optimal location of the TWDNC and TWNDNC protocols. Finally, the probability analyses are justified by executing Monte Carlo simulations.

• Korean Journal of Computational Design and Engineering
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• v.4 no.4
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• pp.339-349
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• 1999

The punose of this paper is to introduce the comprehensive CAM system (called PosCAM) supporting various function requested from shop floor operators. PosCAM is comported of two subsystems (PosCAM I and PosCAM II) which are designed to make up for the contemporary CAD/CAM systems. PosCAM I is mainly for : a) verifying the part programs written in both custom macros and standard G-codes, b) enhancing machining productivity and quality with built-in cutting conditions and feedrate optimization algorithm. PosCAM II is for : a) efficiently managing the numerous part programs and tool data stored in CNC memory, and b) integratively controlling and monitoring various CNCs from the control center through RS-422 with DNC 2 protocol. The developed systems have been tested via various experiments, and can be Applied for the industrial CNC machine shop as a means for enhancing productivity. The PosCAM system has been implemented and successfully used in the Machine Shop Department of PosCAM since march 1998.