• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.3 s.246
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• pp.231-240
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• 2006

Immersive virtual reality (VR) for the manufacturing planning helps to shorten the planning times as well as to improve the quality of planning results. However, VR equipment is expensive, both in terms of development efforts and device. Engineers also spend time to manually repair erroneous 3-D shape because of imperfect translation between 3-D engineering CAD model and VR system format. In this paper a method is proposed to link 3-D engineering CAD model to a multichannel visualization system with PC clusters. The multichannel visualization module enables distributed computing for PC clusters, which can reduce the cost of VR experience while offering high performance. Each PC in a cluster renders a particular viewpoint of a scene. Scenes are synchronized by reading parameters from the master scene control module and passing them to client scenes.

• Journal of the military operations research society of Korea
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• v.22 no.2
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• pp.126-138
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• 1996

The statistical control chart has been proven to be the effective tool most widely used in the manufacturing industry for monitoring and controlling the manufacturing processes. However, the Shewhart chart sometimes gives us false information when the distribution of quality characteristics is skewed. Therefore, it cannot serve as the universal quality control chart if there exist odd events in the manufacturing process. The objective of this study is thus to develop the new technique for constructing the limits of quality control chart based on a sample median and range when the distribution of the underlying population is skewed. This new control chart can effectively solve and manage the processes which have the non-normally distributed quality characteristics frequently occurring in the practical situation.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.4
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• pp.36-43
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• 1992

This paper presents a hierarchical real-time operation control and monitoring scheme of the FMS/CIM center which has been implemented at the Automation and Systems Research Institute of Seoul National University. The hierarchical structure of the whole scheme consists of three lavers. The upper layer is in charge of on-line scheduling, computer network control, shop-floor monitoring and command generation for AGV dispatching, machining, assembly, inspection, set-up, etc. The middle layer has six modules, which are installed in the FMS host computer with the upper layer and run on the multi-tasking basis. Each module is connected to one of six cell controllers distributed in the FMS model plant and transfers operation command down to each cell controller through the Ethernet/TCP-IP local area network. The lower layer is comprised of six cell control software modules for machining cell, assembly cell, inspection cell, set-up stations. AS/RS and AGV. Each cell controller reports the status of the manufacturing facilites to the middle layer as well as ecxecuting the appropriate sequence control of the manufacturing processes.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.108-118
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• 1997

The heterarchical structure provides a more attractive solution to the conventional hierarchical structure as the density and level of distrubution of computing resources in manufacturing system expands. Tracing the evolution of control structures for automated manufacturing systems, this paper discusses the design principles for heterarchical system to reduce complexity, increase extendability, flexible configurability and suggests a good example of real-time adaptation using the concept of intelligent agent of manufac- turing entities and fault diagmosis system.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.124-125
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• 2023

Defect detection during liquid crystal display (LCD) manufacturing has always been a critical challenge. This study aims to address this issue by proposing a data augmentation method based on generative adversarial networks (GAN) to improve defect identification accuracy in LCD production. By leveraging synthetically generated image data from GAN, we effectively augment the original dataset to make it more representative and diverse. This data augmentation strategy enhances the model's generalization capability and robustness on real-world data. Compared to traditional data augmentation techniques, the synthetic data from GAN are more realistic, diverse and broadly distributed. Experimental results demonstrate that training models with GAN-generated data combined with the original dataset significantly improves the detection accuracy of critical defects in LCD manufacturing, compared to using the original dataset alone. This study provides an effective data augmentation approach for intelligent quality control in LCD production.

• Journal of Korean Society for Quality Management
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• v.38 no.4
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• pp.540-548
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• 2010

We consider the problem of selecting the most profitable initial process mean and length of production cycle for manufacturing processes subject to a constant linear trend during the same cycle that varies after resetting the processes. Assuming that the quality characteristic of interest is normally distributed, the optimum initial process mean and the length of production cycle are jointly obtained by minimizing the expected loss per unit time. We assume that the quality loss function due to the deviation from the target value is quadratic and resetting loss is constant. We consider both cases of symmetric and asymmetric quality loss function. An illustrative example is given and sensitivity analysis performed.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.1
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• pp.119-130
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• 2004

The objective of this study was to develop a school uniform sizing system with high coverage rate for middle school boys, who are in the stage of rapid growth, by identifying problems in existing school uniform sizing systems through surveys of students and uniform manufacturing companies, and analyzing juveniles' physical sizes. For this purpose. the study conducted a survey about how middle school boys choose their uniform sizes, and what complaints they have on the size of the uniforms. In addition, it was investigated what is the current state of uniform manufacturing and sizing systems through a survey of uniform companies, and the study identified problems in the size of school uniforms by comparing physical sizes of juveniles' aged 14 to 16 with the sizing systems of the companies and KS standards in 1997. Juveniles' physical data was a part of the material of the national anthropometric data in 1997. Using the two-way distribution of juveniles' height-bust girth and height-waist girth, this study established the sizing system by increasing the number of sizes for the short interval where juveniles' physical sizes are densely distributed whereas limiting the number of sizes for the long interval where juveniles' physical sizes are rarely distributed, considering the difference between companies' standard and KS' standard.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.11
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• pp.78-86
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• 2020

A stress analysis was performed to verify the stability of the digging part of a garlic harvester. A finite element analysis was performed to examine the distribution and concentrated loads on the digging part of the blade and contact plate. Moreover, the stability and maximum deformation of the digging part were determined. Under a distributed load, the maximum principal stress, total deformation, and minimum safety factor ranged from 64-128 MPa, 0.35-0.70 mm, and 2.9-5.7, respectively. The analysis results for the distribution load indicated that the maximum stress occurred at the center of the blade. In contrast, under the concentrated load, the maximum principal stress, total deformation, and minimum safety factor ranged from 66-247 MPa, 0.35-0.79 mm, 1.48-5.53, respectively. The analysis results for the concentrated load indicated that stress and deformation were larger toward the edge and center, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.3
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• pp.83-91
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• 2021

A crawler crane, which consists of a lattice boom, a driving system, and a movable vehicle, is widely used on construction sites. The crawler crane often traverses rough terrain at these sites; as a result, an overload limiter needs to be installed on the crane to prevent it from overturning and breaking. In this paper, we studied the distributed load change in relation to boom length and the angle of rotation of the roller that comes in direct contact with the grounded track shoe. First, we developed a 3D model of a crawler crane and meshed it for finite elements. Then, we performed finite element analysis to derive the load on the roller. Finally, we graphed and examined the roller distributed load data of the case according to boom length and rotation angle. By detecting the load on the roller of the crawler crane, we can predict the potential for the crane to overturn before it happens.

• Journal of the Korea Safety Management & Science
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• v.24 no.2
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• pp.127-134
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• 2022

Production management in the automobile parts industry is carried out according to the production plan of the customer, so it is important to prevent shortages in product supply. As the product composition became increasingly complex, the MES System was built for the purpose of efficient production plan management and inventory management, but its utilization is low. This study analyzed the problems of the MES system and sought to improve it. Through previous studies, it was confirmed that the inventory management of the pull approach that actually occurred in the warehouse is more suitable than the push approach based on the forecast of the warehouse for the volatility, complexity, and uncertainty of orders in the auto parts industry. To realize this, we tried distributed MRP by using the ADO function of VBA to link the standard information of the MES system with Excel and change the structure of the BOM table. Through this, it can help increase the accuracy of production planning and realize efficient inventory management, thereby increasing the utilization of the MES system in the auto parts industry and enhancing the competitiveness of the company.