• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.118-123
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• 2017

It is well known that water jetting is now widely used in the advanced cutting processes of polymers, metals, glass, ceramics, and composite materials because of some advantages, such as heatless and non-contacting cutting different from the laser beam machining. In this paper, we proposed the simulation model of waterjet by lengths and the inner spiral structure of the nozzle. The simulation results show that the outlet velocity of the nozzle is faster than the inlet. Furthermore, we found rapid velocity reduction after passing through the outlet. The nozzle of diameter ${\phi}500$ and length 70mm, shows the optimal fluid width and velocity distribution. Also, the nozzle with inner spiral structure shows a Gaussian distribution of velocity and this model is almost twice as fast as the model without spiral structure, within the effective standoff distance (2.5 mm). In the future, when inserting abrasive material into the waterjet, we plan to analyze the fluid flow and the particle behavior through a simulation model.

• Proceedings of the Korea Association of Information Systems Conference
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• 1996.11a
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• pp.145-155
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• 1996

This paper is to describe the development of nesting software for the materials cutting plan of footwear manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus, the pattern nesting by worker's experience for materials cutting is different from the real cutting results and also different from the error size of yield in degree of worker's skill. Recently, a few of domestic shoes' makers make use of oversee's nesting software. But the nesting software unfits for the domestic actual circumstances, and is complex to use, and is expensive, and is not to be interfaced with the auto cutting machine. Therefore, we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances, which can syncronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility. The architecture of system, the functions of each module, and the information processing procedures of each function are discussed.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.217-226
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• 2006

To maintain competitiveness in the modern automotive market, it is important to carry out process planning concurrently with new car development processes. Process planners need to make decisions concurrently and collaboratively in order to reduce manufacturing preparation time for developing a new car. Automated generation of a simulation model by using the integrated process plan database can reduce time consumed for carrying out a simulation and allow a consistent model to be used throughout. In this research, we developed a web-based system for concurrent and collaborative process planning and flow analysis for an automotive general assembly using web, database, and simulation technology. A single integrated database is designed to automatically generate simulation models from process plans without having to rework the data. This system enables process planners to evaluate their decisions quickly, considering various factors, and easily share their opinions with others. By using this collaborative system, time and cost put into the assembly process planning can be reduced and the reliability of the process plan would be improved.

• Journal of Korea Society of Industrial Information Systems
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• v.1 no.1
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• pp.203-217
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• 1996

This paper is to describe the development of nesting software for the materials cutting plan of footwear manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus, thepattern nesting by worker's experience for materials cutting is different form the real cutting results and also different form the error size of yield in degree of worker's skill. Recently, a few of domestic shoes' makers make use of oversee's nesting software.But the nesting software unfits for the domestic actual circumstances , and is complex to use , and is expensive , and is not to be interfaced with the auto cutting machine. Therefore , we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances, which can synchronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility. The architecture of system, the function of each module, and the information processing proceduresof each function are discussed.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1996.10a
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• pp.145-155
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• 1996

This paper is to describe the development of nesting software for, the materials cutting plan of footware manufacturing processes. In shoes cutting process, almost of the materials cutting plan is dependent upon worker's experience. Thus the pattern nesting by worker's experience for materials cutting is different form the real cutting results and also different from the error size of yield in degree of worker's skill. Recently, a few of domestic shoes makers use of oversee's nesting software. But the nesting software unfits for the domestic actual circumstances, and is complex to use, and is expensive, and is not to be interfaced with the auto cutting machine. Therefore, we have developed the economic nesting systems that are easier for novice to use and fit for the domestic circumstances , which can syncronize with the development of the auto cutting machine. The system comprises interrelated modules for materials information, nesting simulation, utility . The architecture of system, the functions of each module and the information processing procedures of each function are discussed.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.65-65
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• 1998

Manufacturing systems like a motor production process are analyzed using simulations than numerical analyses and/or heuristic methods due to their stochastic properties. The SME(small and medium enterprise) producing automotive motors that develop CIM systems to improve production performance is focused as an application site. We analyze and understand the system exactly using layout based simulation, and then we will suggest the initial feashible production-plan dependent on the layout to overcome weak-points of the current system(i.e., high WIPs, bottle-neck processes, due-date delays and etc.). And, solutions are suggested to increase performances of SMEs producing automotive motors in this paper. The simulation model built in this study is moedlled and analyzed with fully object-oriented methodology using SiMPLE++TM according to properties of production processes of the automotive motor. And, we will introduce ways to verify the model with developed templates for reusability when new needs will be occurred such as designing a new ship, extension or rearrangement of the system, change of production-plans, receiving urgent orders, and so on.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.194.2-194.2
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• 2012

Korea Aerospace Research Institute has developed an earth observation satellite and it was launched into its orbit in 2012 by using a foreign commercial launch vehicle. The launch site authority has imposed safety requirements to the spacecraft developer to ensure the safety of the personnel and to protect launch vehicle, spacecraft and facilities from accidents associated with the satellite operation at the launch site. This paper describes the range safety activities implemented for the satellite and supporting equipments during the whole phase of their design, manufacturing/test and operation at the launch site. To ensure the integrated requirements for safety management and design, system safety program plan has been developed. And based upon the plan, spacecraft developer conducted hazard analysis to identify and establish safety requirements to reflect in designs, procedures, operations. The result of the hazard analysis has been complied into safety data packages and it was reviewed by launch site review board at the safety reviews and finally it was approved to launch.

• Journal of Biomedical Engineering Research
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• v.39 no.6
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• pp.256-267
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• 2018

The number of items and the market size of the senior-friendly medical devices are rapidly increasing, and it is necessary to come up with a safety management plan for senior-friendly medical devices. We searched and analyzed the definition and policy of senior-friendly medical device, and classified medical device items of the Ministry of Food and Drug Safety, calculated market sizes and manufacturing export import results by classification, and investigated the current state of senior-friendly industry and the fields of its culture. In order to prepare a safety management plan, we reduce the number of items that need to be managed intensively by extracting 69 items for administration, that are substantially harmful to the elderly. As specific safety management plans of items for administration, we propose plans for introductions of readability-enhanced labeling, QR codes for cautions and manuals, universal design mandatory, UDI code system with considering a balanced viewpoint of the industry development.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.229-234
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• 2024

A smart factory is defined as a cutting-edge, intelligent factory that integrates all production processes from product planning to sales with information and communication technology. Through these factories, each company produces customized products with minimal cost and time. The smart factory promotion project in Korea has produced positive results even in difficult environments such as the COVID-19 situation. Through the transition to a smart manufacturing production system, the competitiveness of small and medium-sized businesses has been greatly strengthened, including increased productivity and reduced costs. This study was based on surveyed data conducted by organizations related to smart factory promotion in 2020. Significant contents and major characteristics that emerged from the surveyed data were inferred and described. Since the meaningful contents reflect the reality of the company, more efficient promotion of smart factories will be possible in the future.

• The Journal of Information Systems
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• v.30 no.1
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• pp.151-177
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• 2021

Purpose This paper aims to improve management performance by effectively responding to production needs and reducing inventory through synchronizing production planning and procurement in the aviation industry. In this study, the differences in production planning and execution were first analyzed in terms of demand, supply, inventory, and process using the big data collected from a domestic aircraft manufacturers. This paper analyzed the problems in procurement and inventory management using legacy big data from ERP system in the company. Based on the analysis, we performed a simulation to derive an efficient procurement and inventory management plan. Through analysis and simulation of operational data, we were able to discover procurement and inventory policies to effectively respond to production needs. Design/methodology/approach This is an empirical study to analyze the cause of decrease in inventory turnover and increase in inventory cost due to dis-synchronize between production requirements and procurement. The actual operation data, a total of 21,306,611 transaction data which are 18 months data from January 2019 to June 2020, were extracted from the ERP system. All them are such as basic information on materials, material consumption and movement history, inventory/receipt/shipment status, and production orders. To perform data analysis, it went through three steps. At first, we identified the current states and problems of production process to grasp the situation of what happened, and secondly, analyzed the data to identify expected problems through cross-link analysis between transactions, and finally, defined what to do. Many analysis techniques such as correlation analysis, moving average analysis, and linear regression analysis were applied to predict the status of inventory. A simulation was performed to analyze the appropriate inventory level according to the control of fluctuations in the production planing. In the simulation, we tested four alternatives how to coordinate the synchronization between the procurement plan and the production plan. All the alternatives give us more plausible results than actual operation in the past. Findings Based on the big data extracted from the ERP system, the relationship between the level of delivery and the distribution of fluctuations was analyzed in terms of demand, supply, inventory, and process. As a result of analyzing the inventory turnover rate, the root cause of the inventory increase were identified. In addition, based on the data on delivery and receipt performance, it was possible to accurately analyze how much gap occurs between supply and demand, and to figure out how much this affects the inventory level. Moreover, we were able to obtain the more predictable and insightful results through simulation that organizational performance such as inventory cost and lead time can be improved by synchronizing the production planning and purchase procurement with supply and demand information. The results of big data analysis and simulation gave us more insights in production planning, procurement, and inventory management for smart manufacturing and performance improvement.