• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.231-240
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• 1999

A major concern in Concurrent Engineering is the control and management of workload in a period of process. As a general rule, leveling the peak of workload in certain period is difficult because concurrent processing is comprised of various processes, including overlapping, paralleling looping and so on. Therefore, the workload management with resource constraints is so beneficial that effective methods to analyze design process are momentous. This study presents the Timed Petri Nets approach of precedence logic networks, and provides an alternative for users to analyze constraint processes to resolve conflicts of resources. Another approach to Continuous Time Markov Chain using Stochastic Petri Nets is also proposed. These approaches are expected to facilitate resolving resource constrained scheduling problems more systematically in Concurrent Engineering environment.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.06a
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• pp.55-66
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• 1997

A brief introduction to NRC's research activities will be given with special emphasis on membrane processes. NIRC's membrane research group has been involved in many membrane research projects with industrial clients in various sectors of the industry. These projects generally were focused on using membranes for treating industrial wastewater streams for recycling process water, recovering of valuable components and meeting the environmental regulations. The group looked in to various aspects of process development dealing with membrane performance evaluation, optimization of operational parameters, determination of fouling propensities of membranes and simple cost analyses in some cases. Case studies dealing with process development for effluent treatment for the pulp & paper, mining & mineral processing and poultry processing industries will be discussed briefly.

• Journal of Industrial Technology
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• v.25 no.A
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• pp.105-113
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• 2005

A business process flow model for an intermediary type shopping mall consisting of multiple sellers has been presented in this study. Specifically, we defined 11 essential business processes of a front office customer's view point and set up detailed process flow models using IDEF3 (Integrated DEFinition). The characteristic of this study lies in providing a dynamic model rather than static models. The results may form a conceptual framework not only for shopping mall processes but for analysis and improvement toward extended electronic business systems.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.995-998
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• 1995

As the modern industrial processes become more complex, it is getting more difficult to model and control the processes. Naturally, an advanced type of DCS(Distributed Control System) with higher level functions is being sought Advanced DCS is a DCS with advanced functions such as fault diagnosis, GPC(Generalized Predictive Control), NN(Neural Network), and Fuzzy Control. In this thesis, we have studied a fuzzy control algorithm for realizing an advanced DCS. Its algorithm is implemented in a form of function code which is a process control language, being used by the industrial engineers. To verify the realized function code of the fuzzy control, the function code is applied to a continuous casting process of the Pohang Iron & Steel Works in Kwangyang. The rules of the fuzzy control were collected via interviews of the field operators and their operation documents. Finally, usability of the function code of the fuzzy control is shown via simulation for the continuous casting process model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.67
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• pp.27-36
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• 2001

A standard assumption when using a control chart to monitor a process is that the observations from the process output are statistically independent. However, for many processes the observations are autocorrelated and this autocorrelation can have a significant effect on the performance of the control chart. In this paper, we consider combined control chart of monitoring the mean of a process in which the observations can be modeled as a first-order autoregressive process. The Shewhart control chart of residuals-EWMA control chart of the observations is considered and the method of combination is recommended. The performance of the proposed control chart is compared with the performance of other control charts using a simulation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.277-285
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• 1997

In this paper, the definition to flexibility is examined through the literature and re-classified to set up an evaluation model. Flexibility is classified into three categories to find the flexibility types for evaluation. The flexibility type called as manufacturing flexibility is defined and a model is developed to make the performance evaluation possible, The manufacturing flexibility has a heavy relationship to the machine flexibility; and 5 flexibility types out of 8 have relationship to the machine flexibility. This indicates that it is possible to have a pretty good evaluation measure if the machine flexibility related types could be evaluated using a model. There are four different inter-arrival times in the model. A big time saving is observed if the processing time is set equal to 72 second. This indicates that a flexibility affects the system a lot if the inter-arrival time is close to the processing time. The model used in this paper includes multi-processes in a production line with machine failure. However, development of realistic models with buffer between processes and some of the flexibility types not included in this model are remained for further research.

• IE interfaces
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• v.16 no.1
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• pp.44-53
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• 2003

Ready-Mixed Concrete transportation business has been managed by the manual operation and intuitive decision making. This study is on the process improvement on ordering process, and allocation/transportation of trucks commuting between the batching plant and construction sites. Processes of order collection, job dispatch and allocation, and on-time-delivery are analysed and improved. The logistics control system, with GPS system, was developed and implemented based on the reconstructed processes. Performances are evaluated after improved business process and logistics system was applied, and it is shown that waiting time loss is decreased by 55%, and that efficiency is increased by 15%.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.115-122
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• 2016

Price quotations for SOR / RFQ from OEM clients is a very important process in the automotive parts industry. However, OEM clients are demanding a price quote on short duration but it takes long delivery time due to sales, research and development, purchasing, production and cost management departments role and jobs focused on detail and responsibility. And to provide a reasonable alternative with eliminating the waste of non-value processes is to achieve OEM clients satisfaction through standardized and parallel processing, IT system based on the systems and processes of global benchmark companies.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.7
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• pp.66-75
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• 1994

In this paper, we present a new GPC algorithm for plants with known disturbances. Also, based on the above algorithm unidirectional and bidirectional predictive controllers have been proposed concerning plants with input couplings between subprocesses. These predictive control algorithms can be applied to many industrial processes as a multiloop controllers. Simulation results show that the proposed algorithm has improved performance and computing time compared to conventional GPC algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1077-1080
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• 1991

It has been recognized as important subject by users that PID-Controllers widely used in industrial processes must be well-tuned, In this paper, We present an automatic tuning method for PID-Controllers which is based on discrete parameter estimation and application of conventional tuning-rules. The method is easy to implement on microprocessor because critical values are obtained by the mathematical computation. Also, it permits quick on-line tuning. Simulation results show that most processes are well tuned by the suggested tuning method in this paper.