• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1012-1015
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• 2003

Recently technologies have created new principle and theory but the PID control system remains its popularity as the PID controller contains simple structure, including maintenance and parameter adjustment being so simple. The adjust parameter of PID to achieve best response of process which be using time and may be error if user are not expert. Nowadays this problem was solved by develop PID controller which can analysis and auto tune parameter are appropriate with process which used principle of Ziegler ? Nichols but it are expensive and designed for each task. Thus, this paper proposes auto tune PID based on FPGA by use principle of Dahlin which maximum overshoot not over 5 percentages and do not fine tuning again. It have performance in control process are neighboring controller in industrial and simple to use. Especially, It can use various process and low price. The auto tune digital PID processor embedded on chip FPGA XC2S50-5tq-144. The digital PID processor was designed by fundamental PID equation which architectures including multiplier, adder, subtracter and some other logic gate. It was verified by control model of temperature control system.

• Journal of Korean Society for Quality Management
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• v.13 no.2
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• pp.2-7
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• 1985

This paper introduces two approaches of the cost-oriented QC and the process-oriented QC, and compares them on several aspects. The cost-oriented QC tries to assure the specified quality level by sampling inspection within minimum quality cost, while the process-oriented QC aims at realization of target value of quality specification through process adjustment when a product deviates from the target. But the final purpose of both approaches is on quality assurance for markets and consumers. After all, desirability is a question of quality cost. This paper suggests two of cost functions for decision making criterion.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.6
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• pp.96-103
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• 2002

The objective of this study is to adjust the roll gap fur the dimension accuracy of bar in hot bar rolling process considering roll wear. In this study hot bar rolling processes fur round and oval passes have been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental from and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the effects of thermal softening of DCI (Ductile Cast Iron) roll material according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering curve. The new technique developed in this study for adjusting roll gap can give more systematically and economically feasible means to improve the dimension accuracy of bar with full usefulness and generality.

• Human Ecology Research
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• v.53 no.2
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• pp.179-193
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• 2015

This study examined the retirement adaptation process for middle-aged and elderly couples. Twelve couples who had experienced retirement were recruited by theoretical sampling. Data were collected through in-depth interviews and analyzed through the grounded theory approach of Strauss and Corbin (1998). This study showed the results of 124 concepts, 41 sub-categories and 17 categories indicated through an open coding process. As a paradigm in axial coding, the causal conditions in the adjustment procedures of elderly couples whose spouses are retired were 'retirement preparation,' 'retirement acceptance,' and 'marital satisfaction.' A central phenomenon was 'crisis and conflicts of twilight couples.' The contextual conditions that correspond to this phenomenon were 'psychological separation from adult children,' 'division of household labor,' and 'economic status.' The action/interaction strategies to control the phenomenon were 'recognition of marital relationships,' 'conflicts coping,' 'resolution methods,' and 'self-reflection.' The intervening conditions that facilitate action/interaction strategies were 'attitudes of husbands,' 'mutual awareness of couple,' 'health status,' and 'support systems.' The consequences were 'readaptation of marital relationships,' and 'unresolved conflicts,' and 'trying alone.' This research classified middle-aged and elderly couples' adaptation into three types such as mutual effort, separation & resignation, and conflicts vestige. The findings provide basic information to develop a retirement adaptation program for the middle-aged and elderly.

• Journal of the Korean Home Economics Association
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• v.39 no.7
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• pp.125-144
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• 2001

The purpose of this study is to make a preliminary investigation about the diagnostic process for marital preparation against future divorce which will be necessary for developing tools for the process. Delphi tests have been twice held among 23 professionals regarding the concept of marital diagnosis and the areas of marital preparation to be estimated including definitions of the marital preparation for marriage and the status in which marriage has been prepared, and the categorization of the preparation The result of the study is as follows : Firstly, the concept of marital preparation is comprehensive, for it does include various kinds of preparation necessary for adjustment to marital life except the preparation for wedding ceremony. Secondly, the status in which marriage has been prepared can be divided into individual preparation, a couple's relational preparation, and preparation for marital life. Thirdly, premarital preparation education or counselling will be provided for young persons who are not in status of marital preparation. The areas of marital preparation to be estimated are maturity, independence from parents, and good health in terms of individual preparation, and the depth of love, understanding each other, similarity, harmonization, supplementation, capacity of communication, self-control, and all that sort of thing in terms of relational preparation, sex, views about marriage, information about marital life, role division, giving birth to child and rearing, financial management, and understanding both families of husband and wife.

• Journal of the Semiconductor & Display Technology
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• v.2 no.1
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• pp.7-9
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• 2003

In order to predict the moldability of an injection molded part, a simulation of filling is needed. Short shot is one of the most frequent troubles encountered during injection molding process. The adjustment of process conditions is the most economic way to troubleshoot the problematic short shot in cost and time since the mold doesn't need to 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, the intelligent CAE system synergistically combines fuzzy-neural network(FNN) for heuristic knowledge with CAE programs for analytical knowledge. To evaluate the intelligent algorithms, a cellular phone flip has been chosen as a finite element model and filling analyses have been performed with a commercial CAE software. As the results, the intelligent CAE system drastically reduces the troubleshooting time of short shot in comparison with the expert's conventional way which is similar to the golden section search algorithm.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.127-129
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• 2002

In order to predict the moldability of an injection molded part, a simulation of filling is needed. Short shot is one of the most frequent troubles encountered during injection molding process. The adjustment of process conditions is the most economic way to troubleshoot the problematic short shot in cost and time since the mold doesn't need to 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, the intelligent CAE system synergistically combines fuzzy-neural network(FNN) for heuristic knowledge with CAE programs for analytical knowledge. To evaluate the intelligent algorithms, a cellular phone flip has been chosen as a finite element model and filling analyses have been performed with a commercial CAE software. As the results, the intelligent CAE system drastically reduces the troubleshooting time of short shot in comparison with the expert's conventional way which is similar to the golden section search algorithm.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.87-93
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• 2022

The demand for metal-polymer joining technology have been increasing, especially in the industrial fields of automotive and aerospace, which require the manufacturing of various lightweight parts. Conventional joining processes have technical hurdles on aspects such as thermal degradation, need for chemical surface treatment, or complicated process settings. These issues can be alleviated by employing interlocking structures for the metal-polymer joined interface. In this study, we joined 3D-printed metal and polymer parts, which were featured with 3D-printed interlocking structures at their interface. By using high frequency induction heating, the joined region could be locally heated to reduce the thermal degradation and distortion of polymer parts. In addition, through the adjustment of interface morphologies and compression conditions, the polymer flow could be optimized to completely fill the interlocking grooves on metal parts, thereby achieving high joining strength. This suggests feasible guidelines for manufacturing metal-polymer joined structures involving 3D-printed architectures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.1
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• pp.45-50
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• 2021

Machines and facilities are physically or chemically degenerated by continuous usage. The representative type of the degeneration is the wearing of tools, which results in the process mean shift. According to the increasing wear level, non-conforming products cost and quality loss cost are increasing simultaneously. Therefore, a preventive maintenance is necessary at some point. The problem of determining the maintenance period (or wear limit) which minimizes the total cost is called the 'process mean shift problem'. The total cost includes three items: maintenance cost (or adjustment cost), non-conforming cost due to the non-conforming products, and quality loss cost due to the difference between the process target value and the product characteristic value among the conforming products. In this study, we set the production volume as a decreasing function rather than a constant. Also we treat the process variance as a function to the increasing wear rather than a constant. To the quality loss function, we adopted the Cpm+, which is the left and right asymmetric process capability index based on the process target value. These can more reflect the production site. In this study, we presented a more extensive maintenance model compared to previous studies, by integrating the items mentioned above. The objective equation of this model is the total cost per unit wear. The determining variables are the wear limit and the initial process setting position that minimize the objective equation.

• Journal of Korean Society for Quality Management
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• v.45 no.2
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• pp.191-207
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• 2017

Purpose: To develop an interactive version of the conventional process capability-based approach, called 'Interactive Process Capability-Based Approach (IPCA)' in multi-response surface optimization to obtain a satisfactory compromise which incorporates a decision maker(DM)'s preference information precisely. Methods: The proposed IPCA consists of 4 steps. Step 1 is to obtain the estimated process capability indices and initialize the parameters. Step 2 is to maximize the overall process capability index. Step 3 is to evaluate the optimization results. If all the responses are satisfactory, the procedure stops with the most preferred compromise solution. Otherwise, it moves to Step 4. Step 4 is to adjust the preference parameters. The adjustment can be made in two modes: relaxation and tightening. The relaxation is to make the importance of one of the satisfactory responses lower, which is implemented by decreasing its weight. The tightening is to make the importance of one of the unsatisfactory responses higher, which is implemented by increasing its weight. Then, the procedure goes back to Step 2. If there is no response to be adjusted, it stops with the unsatisfactory compromise solution. Results: The proposed IPCA was illustrated through a multi-response surface problem, colloidal gas aphrons problem. The illustration shows that it can generate a satisfactory compromise through an interactive procedure which enables the DM to provide his or her preference information conveniently. Conclusion: The proposed IPCA has two major advantages. One is to obtain a satisfactory compromise which is faithful to the DM preference structure. The other is to make the DM's participation in the interactive procedure easier by using the process capability index in judging satisfaction/unsatisfaction. The process capability index is very familiar with quality practitioners as well as indicates the process performance levels numerically.