• International journal of advanced smart convergence
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• 제10권1호
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• pp.159-165
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• 2021

Electronic devices used in the mobile environments fabricated under the plasma conditions in high vacuum system. Especially for the development of advanced electronic devices, high quality plasma as the process conditions are required. For this purpose, the variable conductance throttle valves for controllable plasma employed to the high vacuum system. In this study, we analyzed the effects of throttle valve applications on vacuum characteristics simulated to obtain the optimum design modelling for plasma conditions of high vacuum system. We used commercial simulator of vacuum system, VacSim(multi) on this study. Reliability of simulator verified by simulation of the commercially available models of high vacuum system. Simulated vacuum characteristics of the proposed modelling agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve schematized as the modelling of throttle valve for the constant process-pressure of below 10-3 torr. Simulation results plotted as pump down curve of chamber, variable valve conductance and conductance logic of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably in plasma process.

• 마이크로전자및패키징학회지
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• 제8권4호
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• pp.53-57
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• 2001

사출성형공정에서 미성형은 가장 빈번하게 발생하는 성형불량중의 하나이다. 이러한 미성형을 해결하기 위해 가상 경제적인 효율적인 방법은 공정조건을 개선하는 일이다. 그러나 대부분의 경우 사출 전문가의 오랜 기간 축적된 경험과 지식에 의존하기 때문에 여러 번의 시행착오을 겪어야 한다. 따라서 본 논문에서는 퍼지 알고리즘을 기반으로 하여 시스템에 적합한 공정조건을 찾는데 있어 시행착오를 줄이고, 또한 비전문가도 쉽게 적용학 수 있는 지능형 공정조건 생성 시스템을 제안하였다.

• 품질경영학회지
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• 제30권2호
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• pp.130-151
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• 2002

This paper investigates the relation between the Process capability index(PCI) and the quality assurance level under various conditions. The effect of the off-targetness of the process mean, deviation from the nomality, the estimation error, and tile measurement error on the quality assurance level is evaluated. Various distributions such as the Student-t, the chi-square, the gamma, the Weibull, and the log-normal distributions are considered to evaluate the deviation from the nomality. The quality levels under abnormal conditions turn out to be severely different from that under the standard condition. We provide tables and graphs of the quality assurance level on various abnormal conditions. In order for the industry users to use the PCI properly, they should refer to the tables and graphs, especially when they are not certain about the standard assumptions on which the PCI depends.

• 산업경영시스템학회지
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• 제18권34호
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• pp.35-42
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• 1995

In the plastic extrusion process, product quality is influenced by work condition for temperature of cylinders and dies. The work conditions are various, so it is difficult to standardization of the work conditions. Therefore, the work conditions are depended on the workers of experience and skill. In the plastic extrusion process, it has five control heating points on the cylinder and three control heating points on the die. In addition, there is one control point on the extrusion process. It is extrusion speed. In this case, we don't know how these affect product quality. We structure the multiple linear regression equation with the temperature of cylinders and dies as independent variables and the product weight as dependent variable. We solve this equation using statistic computer package named Juse-Qcas.

• International Journal of Korean Welding Society
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• 제1권1호
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• pp.44-50
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• 2001

A genetic algorithm was applied to the arc welding process as to determine the near-optimal settings of welding process parameters that produce the good weld quality. This method searches for optimal settings of welding parameters through the systematic experiments without the need for a model between the input and output variables. It has an advantage of being capable to find the optimal conditions with a fewer number of experiments rather than conventional full factorial designs. A genetic algorithm was applied to the optimization of the weld bead geometry. In the optimization problem, the input variables were wire feed rate, welding voltage, and welding speed. The output variables were the bead height bead width, and penetration. The number of levels for each input variable is 16, 16, and 8, respectively. Therefore, according to the conventional full factorial design, in order to find the optimal welding conditions,2048 experiments must be performed. The genetic algorithm, however, found the near optimal welding conditions in less than 40 experiments.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.97-100
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• 1997

In order to predict the moldability of a injection molded part, a simulation of filling is needed. Especially when short shot is predicted by CAE simulation in the filling stage, there are mainly three ways to solve the problem. Modification of gate and runner, replacement of plastic resin, and adjustment of process conditions are the main ways. Among them, adjustment of process conditions is the most economic way in the cost and time since the mold doesn\\`t need t be modified at all. But it is difficult to adjust the process conditions appropriately in no times since it requires an empirical knowledge of injection molding. In this paper, a fuzzy neural network(FNN) based upon injection molding process is proposed to evaluate moldability in filling stage and also to solve the problem in case of short shot. An adequate mold temperature is generated through the fuzzy neural network where fill time and melt temperature are taken into considerations because process conditions affect each other.

• 한국염색가공학회지
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• 제27권4호
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• pp.309-317
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• 2015

This study is the high contraction processing conditions set by the method of the CPB process. And the ultimate goal of this study is the high contraction of the CPB processing test method that can solve the problems of the high-contraction fabric processing method of the current jet dyeing machine. Non-coating process(CPB process) developed by the expression of a soft touch, light weight, functional and to develop excellent breathable nylon fabric. The nylon fabrics established the optimum processing conditions through the high contraction of the various test conditions, the CPB system.(The benzyl alcohol was used as the main constrictor.) At this time, the warp and weft contraction of nylon fabric was about 20%. And it established the constrictor concentration, the treatment temperature, time of a variety of tests. Also non-coating process(CPB process) can develop soft touch, lightweight, excellent air permeability. As a result, we developed a high contraction nylon fabric having a uniform surface. Manufactured fabric is used for Wind-proof and Down-proof.

• 한국기계가공학회지
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• 제18권11호
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• pp.1-8
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• 2019

In this study, we design the feed system and process conditions for a lamp garnish lens of an automobile. For this purpose, four design alternatives are presented and injection molding simulation analyses are performed. The optimal feed system is selected by considering the formability of the product and the cost of mold manufacture. The product formability is assessed by the weld line, warpage, sink mark and the maximum injection pressure, whereas the mold-making cost is estimated by the number of valve gates in the hot runner system. To improve the product formability, process conditions are optimized using an experimental design approach named one-factor-at-a-time. No weld line is generated as a result of the optimization. In addition, it is found the warpage and sink mark are reduced while the maximum injection pressure is increased, compared with those before the optimization.

• 한국주조공학회지
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• 제42권4호
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• pp.209-217
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• 2022

본 연구에서는 전통 유기 주조 시 발생하는 미충전 결함을 방지하기 위하여, 주조 공정 조건 선택 방안을 제시하고자 한다. 공정 조건에 따라 발생하는 결함 유무를 학습하여 어떠한 공정 조건이 주어질 때, 결함 발생 여부를 예측하는 인공지능 모델을 개발하고 검증하였다. 이를 응용하여 적합한 공정 조건을 결정하였고, 추가적인 시뮬레이션의 결과를 상호 비교하여 결정된 조건을 검증하였다. 이를 통해 원하는 사형 모델에서 결함을 방지할 수 있는 주조 공정 조건을 결정할 수 있다. 이와 같은 기계학습 및 전통기술 표준화를 통해 향후 전통 유기의 스마트 공방화에 기여할 수 있을 것으로 판단된다.

• Korea-Australia Rheology Journal
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• 제20권2호
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• pp.79-88
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• 2008

In this study, we focus on the improvement of the filling efficiency in injection molding by application of ultrasonic vibration. While studies about the filling efficiency of typical filling processes in the injection molding have been widely performed, there have been only few studies about the filling efficiency of an ultrasonic process. The effect of the ultrasonic vibration is an important process condition, which influences the flow characteristics of polymer melt. This new condition even affects well-known injection conditions such as cavity pressure, injection temperature and mold temperature. For this study, we carried out a numerical analysis by appropriate modeling and analysis of the ultrasonic process in the filling process. To verify this numerical analysis, we compared the numerical results with the experimental data. Also, we analyzed the filling process in a thin cavity using this numerical analysis. To understand the flow characteristics of polymer melt in the ultrasonic process, we substituted real and complex vibration conditions with simplified and classified conditions according to the position of vibrating cavity surfaces and the phase difference between two opposing cavity surfaces. We also introduced MFR (melt flow ratio) as a new index to estimate the filling efficiency in the ultrasonic process.