• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.391-391
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• 2000

Manufacturing process generally exhibits major or minor variations due to deviation of raw materials, equipment degradation, controller malfunction, and so on. Extensive research based on multivariate statistical process control has been done to monitor the unstable states and indicate a corrective action. A prototype of intelligent operation support system ("ISYS-MSPC") has been developed as a tool that supports the enhanced operation to guarantee the high productivity and a uniform high quality product. This system has been applied to the industrial batch and continuous processes and its performance has been validated .

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 춘계학술대회 논문집
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• pp.24-33
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• 1995

The feasibility of generating controlled surface topographies in single-point conventional turning operations is investigated. First a mathematical model of the surface generation process was developed. Second in order to control the texture of the machined surface a micro-positioning stage and the associated command generation software were designed and built. Experimental examples have shown that surface texture can be precisely controlled and is in good agreement with the theoretical predictions.

• 드라이브 ㆍ 컨트롤
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• 제16권3호
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• pp.42-50
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• 2019

3D printing AM processes have advantages in complex shapes, customized fabrication and prototype development stage. However, due to various parameters based on both the machine and the material, the AM process can produce finished output after several trials and errors in the initial stage. As such, minimizing or optimizing negative factors for various parameters of the 3D printing AM process could be a solution to reduce the trial-and-error failures in the early stages of such an AM process. In addition, this can be largely solved through software simulation in the preprocessing process of 3D printing AM process. Therefore, the objective of this study was to investigate a simulation technology for the AM software, especially Ansys Inc. The metal 3D printing AM process, the AM process simulation software, and the AM process simulation processor were examined. Through this study, it will be helpful to understand 3D printing AM process and AM process simulation processor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.246-249
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• 2005

For agile production methods, manufacturing system requires development of a motion controller which has flexibility of general-purpose motion controller and productivity of specialized-purpose one. In this study we developed a flowchart programming development environment for motion language and process control. A controller designed on this environment can be used as a general purpose motion controller of a machine tool. Design of control programming based on a flowchart has the advantages such as reducing the programming time and improving intuitiveness of interface for users. We created the flowchart-based platform using OPC communication

• 실천공학교육논문지
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• 제16권1_spc호
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• pp.1-9
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• 2024

스마트공장의 디지털 트윈에 대한 도입은 이미 CPS(Cyber Physics System)을 통하여 제조산업에 생산성을 높이고자 제안되었던 개념으로 특정한 산업 공정의 단계에 적용되거나 시뮬레이션이 필요한 단계에서 부분적으로 도입되고 있었다. 그러나 최근 4차산업혁명기술 발전을 통해서 XR(Extended Reality) 기술과 함께 다시 주목을 받고 있다. 하지만 실효성 있는 사례가 많지 않기 때문에 본 연구에서는 제조공정을 장치와 장비 그리고 기술을 분석하여 디지털 쓰레드를 적용한 디지털 트윈을 구축하였고 신호와 정보의 동기화하며 이를 통해서 지능형 공정자동화 장비의 관제와 원격제어와 생산정보의 분석이 가능할 수 있는 플랫폼을 제안하고 이를 개발하였다. 이로써 기존에 제조업에서 활용되어지고 있는 자동화 설비공정 및 장비들에 대한 고장 발생 시 원활한 대처의 어려움과 정확한 고장 발생지점에 대한 확인의 어려움, 그리고 생산설비장비의 고장시점 관리의 어려움, 불량에 대한 원인 및 문제 분석과 대처의 어려움을 해결하는데 도움을 줄 수 있는 제안 내용을 다루었다. 향후 본 연구를 통해서 많은 사례들의 선행 연구에 도움이 되길 기대하고 향후에는 지능형 모델을 통해서 공정 및 생산의 부분별 생산성 증가에 대한 확장 연구가 필요하다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.374-378
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• 2003

From linear motor feed system model, two axis control rules have been applied. As an application process, a flexible disk grinding system process has been also introduced that utilized varying disk orientation with respect to workpiece along with the applied feed speed. A known process model methodologies has been used to fomulate processed surface profiles. Various process conditions including cutting speed, maximum feed speed and orientation angles could applied to observe process results sensitivities. Even though continuous and constant feed speed has been applied to the process, the results from the trapezoidal input velocity profiles would be observed and compared.

• 품질경영학회지
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• 제51권1호
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• pp.55-65
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• 2023

Purpose: The purpose of this study is to propose an optimization process to improve product yield in the process using process data. Recently, research for low-cost and high-efficiency production in the manufacturing process using machine learning or deep learning has continued. Therefore, this study derives major variables that affect product defects in the manufacturing process using eXplainable Artificial Intelligence(XAI) method. After that, the optimal range of the variables is presented to propose a methodology for improving product yield. Methods: This study is conducted using the injection molding machine AI dataset released on the Korea AI Manufacturing Platform(KAMP) organized by KAIST. Using the XAI-based SHAP method, major variables affecting product defects are extracted from each process data. XGBoost and LightGBM were used as learning algorithms, 5-6 variables are extracted as the main process variables for the injection process. Subsequently, the optimal control range of each process variable is presented using the ICE method. Finally, the product yield improvement methodology of this study is proposed through a validation process using Test Data. Results: The results of this study are as follows. In the injection process data, it was confirmed that XGBoost had an improvement defect rate of 0.21% and LightGBM had an improvement defect rate of 0.29%, which were improved by 0.79%p and 0.71%p, respectively, compared to the existing defect rate of 1.00%. Conclusion: This study is a case study. A research methodology was proposed in the injection process, and it was confirmed that the product yield was improved through verification.

• 한국기계가공학회지
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• 제12권4호
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• pp.16-21
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• 2013

This paper presents a DC link voltage control method to reduce the ripple current and the switching loss in the sinusoidal current drive system for the wide-speed range PMSM. The DC link voltage of the three phase inverter in the sinusoidal current drive system is designed by the back-EMF voltage at maximum speed of the PMSM. In general, the drive systems have used the constant DC link voltage without reference to the motor speed. The current ripple causes hysteresis loss and makes noise. In addition, the switching loss on the inverter increases in proportion to the rise in the DC link voltage. In this paper, we propose the variable DC link voltage control method to reduce the current ripple in the PMSM drive system. We show reduction effect of the current repple and the switching loss through simulation results.

• 한국기계가공학회지
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• 제14권4호
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• pp.34-42
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• 2015

As the industry environment is changing to automated systems, engineering education at university has changed with industrial development. Industry technology will be developed, and the industry environment will become more complicated. Therefore, the knowledge that undergraduates have to acquire in university will be extensive. Industries need a person with expertise to react quickly to rapidly changing technology. Therefore, universities need to endeavor to cultivate manpower in technical fields. This is difficult because the contents of engineering education must react quickly to rapidly changing industry technology. This paper proposes a hardware-linked simulation platform for engineering education on the well-used systems in industrial sites.

• 한국기계가공학회지
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• 제19권3호
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• pp.51-56
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• 2020

Research into natural refrigerants that use CO₂, instead of chlorofluorocarbons and hydrofluorocarbons, has increased due to the environmental problems caused by ozone depletion. CO₂ refrigerants are more environmentally friendly than conventional refrigerants because they have better latent heat of evaporation and heat transfer efficiency properties. However, they have very low critical temperatures and require high design pressures; therefore, pressure control valves, which reduce the pressure of the CO₂ refrigerant to a safe level and apply it to the refrigerant air conditioning system, are necessary to secure stability against high pressure. In the present study, we evaluated the flow characteristics and valve performance of the pressure control valve using a CO₂ refrigerant by measuring the pressure, velocity, and flow coefficient. In addition, we examined the applied forces caused by the internal pressure from the highly pressurized CO₂ refrigerant and required thrust characteristics.