• 한국산업정보학회논문지
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• 제10권4호
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• pp.90-96
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• 2005

본 논문에서는 학교, 병원, 관공서와 같은 공공기관에서 사용할 수 있는 멀티 캐스팅 방송 시스템을 개발하였다. 개발된 멀티 캐스팅 방송 시스템은 다양한 멀티미디어 교육매체를 활용할 수 있도록 하였으며, 네트워크를 이용한 원격 제어가 가능하도록 고려하였다. 또한 개발된 방송 시스템은 선택적 개별 방송과 그룹 방송이 가능한 스피커 제어 모듈과 다양한 교육매체의 효율적인 활용을 위한 AV 콘텐츠 제어 모듈 및 조명 제어 모듈을 포함하고 있다. 그리고 통신과정에서는 외란에 강인한 RS-485C 통신을 이용하였으며, 사용자 중심의 GUI 기반 통합 제어 시스템을 개발하여 운영의 효율성 향상을 모색하였다.

• 산업경영시스템학회지
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• 제32권3호
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• pp.40-48
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• 2009

In this article, scheduling of a casting sequence is studied in a casting foundry which must deliver products according to the Just-in-time(JIT) production policy of a customer. When a foundry manufactures a variety of casts with an identical alloy simultaneously, it frequently faces the task of production scheduling. An optimal casting schedule should be emphasized in order to maximize the production rate and raw material efficiency under the constraints of limited resources; melting furnaces and operation time for a casting machine. To solve this practical problem-fulfilling the objectives of casting the assigned mixed orders for the highest raw material efficiency in a way specified by the customer's JIT schedule, we implement simple integer programming. A simulation to solve a real production problem in a typical casting plant proves that the proposed method provides a feasible solution with a high accuracy for a complex, multi-variable and multi-constraint optimization problem. Employing this simple methodology, a casting foundry having an automated casting machine can produce a mixed order of casts with a maximum furnace utilization within the due date, and provide them according to their customer's JIT inventory policy.

• Korea-Australia Rheology Journal
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• 제19권1호
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• pp.27-33
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• 2007

The co-extrusion of multi-layer films has been studied with the focus on its process stability. As in the single-layer film casting process, the productivity of the industrially important multi-layer film casting and the quality of thus produced films have often been hampered by various instabilities occurring in the process including draw resonance, a supercritical Hopfbifurcation instability, frequently encountered when the draw ratio is raised beyond a certain critical value. In this study, this draw resonance instability along with the neck-in of the film width has been investigated for a three-layer film casting using a varying width non-isothermal 1-D model of the system with Phan-Thien and Tanner (PTT) constitutive equation known for its robustness in portraying extensional deformation processes. The effects of various process conditions, e.g., the aspect ratio, the thickness ratio of the individual film layers, and cooling of the process, on the stability have been examined through the nonlinear stability analysis.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.337-351
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• 2019

We Proposed a new technology to develop vertical type multi-joint robot system enable to adapt in high temperature environment. The main contents is a new approach to design a vertical type articulated robot with prismatic joint and analysis of thermal for process automation of casting and forging. The proposed robot is suitable to use handling working parts of casting and forging. for the manufacturing process of forging and casting. The reliability is illustrated that the proposed technique is more stable and robust than the conventional system. This study is concerned with an analytical methodology of kinematic computation for 7 DOF manipulators for optimization of forging manufacturing process.

• 산업경영시스템학회지
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• 제31권3호
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• pp.17-23
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• 2008

In this research article, scheduling a casting sequence in a job-shop type foundry involving a variety of casts made of an identical alloy but with different shapes and II weights, has been investigated. The objective is to produce the assigned mixed orders satisfying due dates and obtaining the highest ingot efficiency simultaneously. Implementing simple integer programming instead of complicated genetic algorithms accompanying rigorous calculations proves that it can provide a feasible solution with a high accuracy for a complex, multi-variable and multi-constraint optimization problem. Enhancing the ingot efficiency under the constraint of discrete ingot sizes is accomplished by using a simple and intelligible algorithm in a standard integer programming. Employing this simple methodology, a job-shop type foundry is able to maximize the furnace utilization and minimize ingot waste.

• 융합보안논문지
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• 제5권4호
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• pp.49-58
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• 2005

환자의 이동성과 경제적인 의료서비스를 제공하는 미래의 원격의료시스템으로서 유비쿼터스 센서 네트워크(USN) 구조를 제시한다. 본 USN 구조는 계층적 라우팅과 평면 라우팅을 접합하여 개선한 것으로서 멀티캐스팅 통신을 지원하는 셀 기반의 안전한 4계층 구조이다. 본 구조에서는 환자의 개인정보 보호 및 안전한 의료정보를 위하여 경량의 PKI 기반 보안 통신 프로토콜을 채택하고 있으며 이에 따른 핵심 통신 과정을 함께 제시하였다.

• 대한임베디드공학회논문지
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• 제2권4호
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• pp.221-226
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• 2007

This paper propose a control network system based on IEEE1394 for a multi body robot control. The IEEE1394 has the characteristic of high speed(400Mbps), real-time, stability and plug&play. And IEEE1394 also supports freeform daisy chaining, branching and hot plugging, which reduce cabling complexity and make a system simple. Especially, multi host and broad casting support network data sharing method which is suitable for control network for multi body robot. Through experiment, we show that the proposed control network can interface 48 joints (BLDC motors, gears, and encoders) and four 6-axis force/torque sensors with 4Khz communication bandwidth, which is adequate for a multi body robot.

• 전기학회논문지
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• 제58권9호
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• pp.1681-1688
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• 2009

This paper proposes a new fault restoration method which adopts the recloser as top agent to release the problems of the data concentration and fault processing delay of the existing DAS(distribution Automation System) under the ubiquitous distribution system. In proposed method, top agent collects the data based on the multi-casting communication with the tie switches of the interconnection point, and then selects a closed switch(tie switch) to transfer the sound outage load to other feeders based on the heuristic search strategy step by step until the load transfer work is finished. Here, a new heuristic rule is developed which can guarantee the relational load balancing and line loss from the collected voltage data. Finally, the several faults are simulated for typical multi-section and multi-interconnection distribution system to prove the effectiveness of the proposed strategy, in particular, for each simulation cases, the load balancing index and line loss index of the obtained solution from the proposed method is compared with those of all of feasible solutions.

• 시스템엔지니어링학술지
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• 제10권2호
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• pp.21-31
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• 2014

Recently, global market competition of iron and steel products is ever increasing due to over-supply from increased number of industries in rapidly growing countries, such as China, Brazil, and Indonesia. To occupy the big market, major industries are trying to develop high quality, high performance steel products via developing a new iron and steel making process. In other words, development of a new and innovative steel plant is a key to cope with the tough situation. Design and development for the life cycle of iron and steel making plant is very much complex and multi-disciplinary. In this paper, Plant Systems Engineering (PSE), a tailored SE process for industrial plant based on ISO/IEC 15288 is used for the design of Continuous Casting Process (CCP) Plant system. The CCP is a crucial process in steel making plant, whose design technology is occupied by the advanced foreign companies. For the sake of increasing engineering capability for the design of CCP, we applied PSE Process for the renovation of the existing CCP Process. Through the study, we were convinced that the applied method can be used for other plant systems, and SE is really the way of thinking, design, and development of modern complex and multi-disciplinary systems where high risk factors are present throughout the whole life cycle.

• 한국정밀공학회지
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• 제33권1호
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• pp.77-83
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• 2016

Intricate deflection requires many conventional actuators (motors, pistons etc.), which can be financially and spatially wasteful. Novel smart soft composite (SSC) actuators have been suggested, but fabrication complexity restricts their widespread use as general-purpose actuators. In this study, a hybrid manufacturing process comprising 3-D printing and casting was developed for automated fabrication of SSC actuators with $200{\mu}m$ precision, using a 3-D printer (3DISON, ROKIT), a simple polymer mixer, and a compressor controller. A method to improve precision is suggested, and the design compensates for deposition and backlash errors (maximum, $170{\mu}m$). A suitable flow rate and tool path are suggested for the polymer casting process. The equipment and process costs proposed here are lower than those of existing 3D printers for a multi-material deposition system and the technique has $200{\mu}m$ precision, which is suitable for fabrication of SSC actuators.