• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.298-303
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• 2013

Magnetic abrasive polishing is one of the most promising finishing methods applicable to complex surfaces. Nevertheless this process has a low efficiency when applied to very hardened materials. For this reason, EP-MAP hybrid process was developed. EP-MAP process is expected to machine complex and hardened materials. In this research, deburring process using EP-MAP hybrid process was proposed. EP-MAP deburring process is applied to micro channel, thereby it can obtain both deburring process and polishing process. EP-MAP deburring process on the micro channel was performed. Through design of experiment method, error of height in this process according to process parameter is analyzed. When the level 1 parameter A(magnetic flux density) and level 2 parameter B(electric potential), C(working gap) and level 3 parameter D(feed rate) are applied in the deburring process using EP-MAP hybrid process, it provides optimum result of EP-MAP hybrid deburring process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.445-449
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• 1997

In order to provide a manufacturing system with efficiency and flexibility to cope with the changes in shop floor status, the integration of process planning and operations scheduling is required. In this paper,an integrated system of process planning and operations scheduling based on the concept of process net model is presented. The process net model includes the alternative process plans. The integrated system is applied for prismatic parts.

• Knowledge Management Research
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• v.20 no.3
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• pp.39-47
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• 2019

Response surface methodology (RSM) is a group of statistical modeling and optimization methods to improve the quality of design systematically in the quality engineering field. Its final goal is to identify the optimal setting of input variables optimizing a response. RSM is a kind of knowledge management tool since it studies a manufacturing or service process and extracts an important knowledge about it. In a real problem of RSM, it is a quite frequent situation that considers multiple responses simultaneously. To date, many approaches are proposed for solving (i.e., optimizing) a multi-response problem: process capability function approach, desirability function approach, loss function approach, and so on. The process capability function approach first estimates the mean and standard deviation models of each response. Then, it derives an individual process capability function for each response. The overall process capability function is obtained by aggregating the individual process capability function. The optimal setting is given by maximizing the overall process capability function. The existing process capability function methods usually use the arithmetic mean or geometric mean as an aggregation operator. However, these operators do not guarantee the Pareto optimality of their solution. Moreover, they may bring out an unacceptable result in terms of individual process capability function values. In this paper, we propose a maximin-based process capability function method which uses a maximin criterion as an aggregation operator. The proposed method is illustrated through a well-known multiresponse problem.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.509-516
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• 2009

This paper is the study on improving the coefficient of utilization of material in deep drawing process. Cylindrical cup drawing process is widely used in sheet metal forming process. The blank shape is one of the important things in sheet metal forming process. It is produced for the bridge of blank in a blanking process. The coefficient of utilization of material is much effected by this bridge of blank. This study offered a new process method to reduce the loss of material. The new blank shape offered and manufactured by new process method is investigated by a finite element method and the experiment. Then the wrinkling, the punch load, the thickness distribution is observed. This result is different from the result of circular blank process. And it is got that the Max strain, the wrinkle and the height of the wrinkle are effected by the holding force and the punch load. As a result, if the processing optimum condition is found, the loss of material will be reduced. It is necessary to research systematically about determining the optimum value of process variables.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.4
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• pp.179-186
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• 2002

This paper is the study on improving the coefficient of utilization of material in deep drawing process. Cylindrical cup drawing process is widely used in sheet metal forming process. The blank shape is one of the important things in sheet metal forming process. It is produced for the bridge of blank in a blanking process. The coefficient of utilization of material is much effected by this bridge of blank. This study offered a new process method to reduce the loss of material. The new blank shape offered and manufactured by new process method is investigated by a finite element method and the experiment. Then the wrinkling, the punch load, the thickness distribution is observed. This result is different from the result of circular blank process. And it is got that the Max strain, the wrinkle and the height of the wrinkle are effected by the holding farce and the punch load. As a result. if the processing optimum condition is found, the loss of material will be reduced. It is necessary to research systematically about determining the optimum vague of process variables.

• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.435-446
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• 2000

Statistical process control(SPC) and engineering process control(EPC) are two strategies for quality improvement that have been developed independently. EPC seeks to minimize variability by adjusting compensatory variables in order to make the process level close to the target, while SPC seeks to reduce variability by monitoring and eliminating causes of variation. One purpose of this paper is to propose the IMA(0,1,1) model as the in-control process model. For the out-of-control process model we consider two cases; one is the case with a step shift in the level, and the other is the case with a change in the nonstationarity. Another purpose is to suggest the use of an integrated process control procedure with adjustment and monitoring, which can consider the proposed process model effectively. An integrated control procedure will improve the process control activity significantly for cases of the proposed model, when compared to the procedure of using either EPC or SPC, since EPC will keep the process close to the target and SPC will eliminate special causes.

• IE interfaces
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• v.15 no.1
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• pp.64-72
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• 2002

Broaching machine is widely used for machining inner shaped slots in the work-pieces, and provides vertical motion (usually hydraulically powered) between tool and work-piece. In this study, we modelled the tool life process and investigated economic tool life of broaching machine. Tool life process is divided into wear-process and succeeding failure process. Wear process is defined as machining wear and failure process as 'chipping' occurred by random shock. We modelled wear process as linear regression function for products amounts and assumed failure process as Poisson process. Economic tool life is defined as the number of lots which minimizes average tool related cost per lot and analyzed by using age replacement policy technique. As tool-related cost factors, we consider tool replacement cost, tool maintenance cost and quality costs of products. The results of this study can be applied to analyze life process of general machining tools.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.233-240
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• 1998

Recently, Hong-Jun Kim et al. introduced an improved process incapability index $C^*_{psk}$ by the transformation of the $C_{psk}{\;}C^*_{psk}$. A simple transformation of $C_{psk}$, can be regard as a process incapability index, provides an uncontaminated separation between information concerning the process accuracy and precision while this kind of information separation is not available with the $C_{psk}$. By an identical conception, in this article a new process incapability index $C^*_{psk}$ for Non-Normal process can be proposed by the transformation of the process capability index $C^*_{psk}$. The motivation behind introduction of $C^*_{psk}$ is that process capability index $C^*_{psk}$ cannot give information of the process accuracy and precision. A significant result of this research that $C^*_{psk}$ for the case where the target value T is equal to the midpoint of the specification limits or not Is evaluated without respect to T. Accordingly, $C^*_({psk})$ will be propose a reasonable process incapability measure for Non-Normal process

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.181-196
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• 1998

The aim of this research is the development of a CAPP system which can use the old experience of process planning to generate a process plan for a new part and learn from its own experience using the concept of stratified case-based reasoning(CBR). A process plan is determined through the hierarchical process planning procedure that is based on the hierarchical feature structure of a part. Each part and case have their own multiple abstractions that are determined by the feature structure of the part. Retrieving the case in stratified case-based process planning is accomplished by retrieving the abstraction that is most similar to the input part abstraction in each abstraction level of the case-base. A new process plan is made by the adaptation that translates the old case's process plan into the process plan of a new part. Operations, machines and tools, setups and operation sequence in each setup are determined in the adaptation of abstraction using some algorithms and the reasoning based on knowledge-base. By saving a new part and its process plan as a case, the system can use this new case in the future to generate a process plan of a similar part. That is, the system can learn its own experience of process planning. A new case is stored by adding the new abstractions that are required to save as the new abstraction to the existing abstractions in the case-base.

• Korean Institute of Interior Design Journal
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• v.15 no.3 s.56
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• pp.193-200
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• 2006

Any design process is interwoven with numerous intermediate design representations and information. On the other hand, designers proceed the design through various activities. It has always been a difficult task to model the design process, yet there are many significant research outputs that explain the design process through the cognitive approaches. This research started from the necessity of an interactive system which externalize the elements of design process in a visual or tangible manner. In order to do so, a design model, specifically a design process representation model was necessary to capture and represent design process. Several concepts such as design issue, design concept, and design form were defined through the empirical studies of design practices. The assumption is that the design process can be effectively captured by the presented system and it can help both designers and tutors review and analyze the design process. It should also help novice designers learn from expert designer's design process patterns. The system represents design process pattern in a interactive graphic environment. It also provides various useful features to enhance the analysis of design process. This paper presents theoretical groundwork and development process of the design process visualizer. The representation model is presented, and the application of the system is reviewed. Discussions on the further development directions include critical evaluation of the system.