• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.90-96
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• 2009

Injection molding process is one of the most important methods to produce plastic parts with high efficiency and low cost. Today, injection molded parts have been increased dramatically the demand for high strength and quality applications. This report investigates that the optimum injection molding condition for minimum of shrinkage. Molding shrinkage is occurred by several reasons such as thermal shrinkage, a hardening process and compressibility. This report concentrate on shrinkage by a hardening process. As Change a holding pressure and holding time, checked deflections of X, Y, Z directions by shrinkage based on same condition. In conclusion, it was found that holding pressure is stronger and holding time is longer, the deflection by shrinkage is smaller because injection molding needs enough time for cooling and high density. The FEM Simulation CAE tool. Moldflow, is used for the analysis of injection molding process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.1
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• pp.34-44
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• 1997

This study presents the recursive constraint bounding(RCB) method to reduce the cycle time in internal cylindrical plunge grinding process. This method can cope with process noise as well as modeling bias. The main features of RCB method are its utilization of measurements at the end of each cycle and its use of monotonicity analysis for determining the extremes of bias and noise. This method is investigated in simulation and evaluated by experiment in internal cylindrical plunge grinding operation. The results from simulation and experiment show that it is effective in reducing cycle time in spite of modeling uncertainty in the forms of process noise and modeling bias.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.178-181
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• 2002

We studied the characteristics of polishing pad, which can apply W CMP process for global planarization of multilevel interconnection structure. Also we investigated the effects of different sets of polishing pad. The purpose of this experiment is the cost reduction by the increase of pad life time and decrease of cycle time and slurry usage with new pad. Especially we studied the effect of polishing pad for CMP process by this experiment of polishing pad that is consumables material during CMP process. We expecting the increase of process throughput and improvement of device manufacturing yield because we can choose optimum polishing pad through this result.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.487-493
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• 2004

This paper consider a six sigma project for improving the TIP life time in a spot welding process. The project follows a disciplined process of five phases: define, measure, analyze, improve, and control. A process map is used to identify process input and output variables. Nine key process input variables are selected by using C&E matrix and FMEA, and finally four vital few input variables are selected from analyze phase. The optimum process conditions of the four vital few input variables are jointly obtained by maximizing TIP life time using DOE.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.55-59
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• 2004

Recently, life cycle and lead-time of products have been shortened with the demand of customers. Therefore, it is important to reduce time and cost at the step of manufacturing trial molds. In order to realize three dimensional shape on CAD, the machining process has been widely used because it offers practical advantages such as precision and versatility. However, traditional machining process spends a lot of time in cutting product and the remained material causes trouble such as inconvenience for clean. In this work, a new machining process using the hot tool has been proposed to overcome those limitations. In the process, the hot tool moves the predetermined path and the heat of the tool decomposes the remained material. In order to set up the process, the hot tool to satisfy requirements is designed and the material thermal properties are obtained using the DSC and TGA machine. The relationships between process parameters and thermal radius of the tool are obtained through experiment.

• Journal of Computing Science and Engineering
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• v.9 no.2
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• pp.108-117
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• 2015

Interrupt handling is generally separated from process scheduling. This can lead to a scheduling anomaly and priority inversion. The processor can interrupt a higher priority process that is currently executing, in order to handle a network packet reception interruption on behalf of its intended lower priority receiver process. We propose a new network interrupt handling scheme that combines interrupt handling with process scheduling and the priority of the process. The proposed scheme employs techniques to identify the intended receiver process of an incoming packet at an earlier phase. We implement a prototype system of the proposed scheme on Linux 2.6, and our experiment results show that the prototype system supports the predictable real-time behavior of higher priority processes even when excessive traffic is sent to lower priority processes.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.337-339
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• 1992

This paper deals with the tuning method of PID controls for process controls. It introduces the normalized process gain and the normalized process dead-time for processes based on Ziegler-Nichols tuning methods. In the case of PID auto-tuning, the first, this method applies Ziegler-Nichols tuning method and introduces the set-point weighting for reducing overshoot in the large normalized process gain or small normalized process dead-time, the second, this method is modified and includes the set-point weighting in the small normalized process gain or large normalized process dead-time. In the case of PI auto-tuning, this method is modified for reducing overshoot. This paper obtains empirical data with Ziegler-Nichols methods for refined Ziegler-Nichols tuning methods.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.94-101
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• 2013

Injection molding process is one of the most important methods to produce plastic parts with high efficiency and low cost. The objective of this study is to implement the best plastic injection molding process for LED TV speaker frame. Moldflow analysis and simulation of plastic injection molding process were carried out in order to predict optimal modeling operation conditions and then injection molded part was produced various type of resin temperature, filling time and injection pressure variation. the result was that the best injection molding condition is set as 60bar pressure, 2sec filling time and $310^{\circ}C$ degree. The study result would be useful to variety of plastic injection molding process.

• Korean Management Science Review
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• v.26 no.1
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• pp.127-136
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• 2009

This paper purposes analyzing how task assignments influence on business process efficiency, and improving business process efficiency in Business Process Management (BPM) environments. For this purpose, task assignment is categorized into dynamic assignment and static assignment. Dynamic assignment binds a user to a task at process run-time, whereas static assignments assigns a task to a user at process build-time. So far, the influence of task assignment methods has not been studied. We, in this paper, analyze the business process efficiency using two different assigning rule, in terms of cycle time as a efficiency measure. The comparison result can provide a guideline for a company who wants to employ commercial BPM systems.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.15-20
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• 2000

The studies of swine wastewater treatment aim to development of process using soil microorganism. Removal rate of swine wastewater containing organic matter was 99 percent in case of high loading rate. Microorganism was devoted to improve the treatment efficiency of the process. According to the result obtained from biological treatment of high loading rate swine wastewater. Hydraulic retention time was 2.3 days in unit process of biological phosphorus removal. BO $D_{rm}$ / $P_{rm}$ ratio was 1122 in room temperature anaerobic process and 355.6 in mesophilic anaerobic process. And then phosphorus removal rate mesophilic anaerobic process was 3 time as much as than room temperature acaerobic process.