• 한국경영과학회지
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• 제26권4호
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• pp.133-141
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• 2001

Rapid development in computer and network technology these days has created in environment in which decisions for manufacturing companies can be made in a much broader perspective. Especially, better decisions on production and distribution planning(PDP) problems can be made laking advantage of real time information from all the parties concerned. However, since the PDP problem-a core part of the supply chain management- is known to be the so-called NP-hard problem, so heuristic methods are dominantly used to find out solutions in a reasonable time. As one of those heuristic techniques, many previous studios considered genetic a1gorithms. A standard genetic a1gorithm applies rules of reproduction, gene crossover, and mutation to the pseudo-organisms so the organisms can pass along beneficial and survival-enhancing trails to a new generation. When it comes to representing a chromosome on the problem, it is hard to guarantee an evolution of solutions through classic a1gorithm operations alone, for there exists a strong epitasis among genes. To resolve this problem, we propose a hybrid genetic a1gorithm based on Silver-Meal heuristic. Using IMS-TB(Intelligent Manufacturing System Test-bed) problem sets. the good performance of the proposed a1gorithm is demonstrated.

• 한국산학기술학회논문지
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• 제1권2호
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• pp.69-74
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• 2000

중소기업의 정보화 영역은 생산정보화, 경영관리자동화, 네트워크화의 3가지 요소로 구분된다. 본 논문은 경영정보시스템을 이용하는 경영관리자동화를 주로 다룬다. 기능적으로 보면 생산, 판매, 인사, 회계 등 4개의 분야로 크게 나누어지나 대부분의 중소기업은 생산과 판매에 더 많은 주안점을 둔다. 따라서 이 두 개의 핵심 기능을 중심으로 객체지향방법론에 기반하여 통합된 정보시스템이 구축된다. 본 논문이 제안하는 단계별모델의 중요한 하나의 단계인 이 통합시스템은 단순화와 집중화의 원리를 수용했을 뿐만 아니라 객체지향패러다임을 이용하여 모듈화 및 친숙화를 구현하였다.

• 산업경영시스템학회지
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• 제31권3호
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• pp.117-124
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• 2008

Ultra-high voltage transformer industry has characteristic of small quantity batch production system by other order processing unlike general mass production systems. In this industry, observance of time deadline is very important in market competitive power security and company continued existence. The transformer winding is a process that rolls a coil is coated with an electric insulation material in order to generate the required voltage using the voltage fluctuation. The winding process is very important production process in the extra-high voltage transformer manufacturing industry because winding process is core process that occupy weight about half of whole process and is process that decide current ratio of transformer. This paper proposes a statistical calculation and control method of planned leadtime on the basis of real data and informations for the A company in transformer winding process. Moreover, we develop unit process scheduling system.

• Journal of Welding and Joining
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• 제33권3호
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• pp.12-18
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• 2015

The ultimate goal of developing body is revealed the "lightweight" at latest EuroCarBody conference 2012 and the most core technology is joining process to make lightweight car body design. Accordingly, in this study, the car body assembly line for the assembly process applies to any introduction, particularly in the assembly of aluminum alloy and composite materials applied by the process for the introductory approached. Process were largely classified by welding (laser, arc, resistance, and friction stir welding), bonding (epoxy bonding) and mechanical fastening (FDS, SPR, Bolting and clinching). Applications for each process issues in the case and the applicable award was presented, based on the absolute strength of the test specimens and joining characteristics for comparative analysis were summarized. Finally, through this paper, we would tried to establish the characteristics of the joint for lightweight structure.

• 한국융합학회논문지
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• 제8권10호
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• pp.185-191
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• 2017

최근, LNG는 저렴한 가격과 친환경적 연료 등의 이유로 선박용 대체연료로 각광을 받고 있으며, 그 수요량도 급성장이 예상된다. 그러나, 선박의 LNG 연료공급을 위한 극저온펌프(Cryogenic Pump) 제작과 관련한 국내 기술력은 매우 미흡한 실정으로 핵심 부품의 설계와 제작 기술이 절실한 시점이다. 따라서, 본 연구는 선박용 LNG 공급 시스템용 극저온 잠액식 원심펌프(Cryogenic Submerged Centrifugal Pump)의 단계별 개발절차에 대하여 기술하였다. 그리하여, 각 단계별 특성 및 주요 개발항목을 공학적이고 관리적인 측면에서 접근함으로써 실질적이고 구체적인 개발방법을 제시하는데 연구 목적을 두었다.

• 한국기계가공학회지
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• 제14권4호
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• pp.160-166
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• 2015

Ultrasonic machining (USM) has been considered a new, cutting-edge technology that presents no heating or electrochemical effects, with low surface damage and small residual stresses on brittle workpieces. However, nowadays, many researchers are paying careful attention to the disadvantages of USM, such as low productivity and tool wear. On the other hand, in this study, a high-performance rotary ultrasonic drilling (RUD) spindle is designed and assembled. In this system, the core technology is the design of an ultrasonic vibration horn for the spindle using finite element analysis (FEA). The maximum spindle speed of RUM is 9,600 rpm, and the highest harmonic displacement is $5.4{\mu}m$ noted at the frequency of 40 kHz. Through various drilling experiments on glass workpieces using a CVD diamond-coated drill, the cutting force and cracking of the hole entrance and exit side in the glass have been greatly reduced by this system.

• 한국기계가공학회지
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• 제11권3호
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• pp.174-181
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• 2012

The spindle unit is a core part in high precision machine tool. Rotation accuracy of spindle unit is needed for high dignity cutting and improving the performance of machine tool. However, there are many factors to effect to rotational error motion(rotation accuracy). This study studied how rotational error motion is variation when unbalance amount is variation. Rotation accuracy of initial spindle unit is decided depending on parts and assembly such as bearing. When it is rotation, vibration and noise is appeared depending on volume of unbalance amount, so it works to decrease unbalance amount. The purpose of the study tests that unbalance amount how much effects to initial rotation condition. The result of the study shows that accuracy of parts and assembly is highly necessary to reach high rotation accuracy and unbalance amount hardly effects to initial rotation accuracy. However, it shorten spindle's life because vibration and noise is increasing by increasing unbalance amount and we can expect situation that rotation accuracy is falling by long time operation.

• 한국기계가공학회지
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• 제19권8호
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• pp.43-49
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• 2020

The growth of the AR/VR market due to the advent of the 4th Industrial Revolution begins with the development of the display industry. The development of OLED and flexible displays is further accelerated by the development of R2R technology. Micro-processing technology using a fast tool servo (FTS), the core technology in R2R processes, is making technological progress in increasingly diverse ways. This paper proposes a method to develop an FTS for horizontal driving and presents this method through experiments and analyses. To develop a swing-type FTS based on a seesaw motion, a rotational moment hinge structure was designed for each type, and research was conducted to determine an effective design method. A cantilever-based swing-type FTS was developed in two variations: one with single-side hinges and another with dual-side hinges. The parameters in the design of the swing-type FTS are rotational moment, natural frequency, and material selection. In conclusion, an FTS with a single-side hinge demonstrates the high performance required for micro processing.

• 한국주조공학회지
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• 제40권1호
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• pp.1-6
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• 2020

Many studies involving a thermal stress analysis using computational methods have been conducted, though there have been relatively few experimental attempts to investigate thermal stress phenomena. Casting products undergo thermal stress variations during the casting process as the temperature drops from the melting temperature to room temperature, with gradient cooling also occurring from the surface to the core. It is difficult to examine thermal stress states continuously during the casting process. Therefore, only the final states of thermal stress and deformations can be detemined. In this study, specimens sensitive to thermal stress, were made by a casting process. After which the residual stress levels in the specimens were measured by a hole drilling method with Electron Speckle-Interferometry technique. Subsequently, we examined the thermal stresses in terms of deformation during the casting process by means of a numerical analysis. Finally, we compared the experimental and numerical analysis results. It was found that the numerical thermal stress analysis is an effective means of understanding the stress generation mechanism in casting products during the casting process.

• International Journal of Precision Engineering and Manufacturing
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• 제6권3호
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• pp.45-50
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• 2005

This paper proposed an efficient manufacturing system using the OMM (on-machine measurement) system. The OMM system is software-based 3D modeler for inspection on machine, and it is interfaced with machine tools via RS232C. The software is composed of two inspection modules; one is touch probe operating module, and the other is laser displacement sensor operating module. The module for touch probe needs the inspection feature extracted from CAD data. The touch probe moves to workpiece by three operating modes as follows: manual, general and automatic mode. The operating module of the laser displacement sensor is used to inspect profiles and very small holes. An advantage of this inspection method is the ability to execute on-line inspection during machining or afterward. The efficiency of proposed system which can predict and define the machining errors of each process was verified, so the developed system was applied to inspect a mold-base (cavity, core).