• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.22-28
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• 1998

It is required to automate a manufacturing industry of a glasses frame, because of the inaccuracy in assembly and shortage of labor. So, in this paper, rim-lock electric welding system has been developed in order to automate a electric welding process and to increase welding quality. Rim-lock electric welding system consists of circular and linear feeder, holder for welding rim and lock, and the equipment for silver-lead provision and so forth. Main controller is a V55 microprocessor which is easy to be expanded into other function. Control program is programed using 'C' language which is easier than other language in coding, modification and adding function. At the practical welding that Rim-Lock electric welding system from this study is used, we can get such advantages as uniform quality of electric welding, continuous operation and improved productivity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.87-95
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• 2005

The object of this study is to investigate the effect of joinability by using acoustic emission(AE) signals and doing a pattern recognition for weld heat affected zone(HAZ) in tensile testing. This study was carried out an SWS 490A high tension steel for electric shielded metal arc welding(SMAW), $CO_2$ gas arc welding and TIG welding. And correspondingly, the root openings are 3, 4 and 2.8mm. The results of the tensile test of weld HAZ come out electric shield arc welding $>\;CO_2$ gas arc welding > TIG welding in case of single welding. It is believed that this is a phenomenon where difference of its root opening or base metal thickness. Also, the technique of AE is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.

• Transactions of Materials Processing
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• v.27 no.2
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• pp.107-114
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• 2018

Although the application of high strength steel is increasing to cope with the various updated regulations of automobiles, high strength steel sheets are difficult to formulate due to the high tensile strength and low elongation of those materials. In this study, the slide motion was controlled using a servo press in order to improve the formability of the process of manufacturing ultra-high strength steel of above 1.2GPa. Also, the friction characteristics of the slid motion were investigated through a high speed friction test. The slide motion was optimized by adjusting the number of steps, the rising start position and the rise height of the slide. At the same time, it is noted that the optimal slide motion increased the forming depth by about 40%. From the results of the high speed friction test, the application of the slide motion reduces friction resistance, thereby improving friction characteristics and improving formability.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1107-1111
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• 2005

This paper presents a design of Programmable logic Controllers which are well known for a long time that can be applied to be a controller for an automatic machine in industries. However, most of them have been imported from oversea country. This research focuses on the development of PLC by KMITL staff. This PLC system is consists of CPU unit, Digital I/O RTU unit, ANALOG RTU unit. The implementation of the CPU scan time and I/O refresh are principle to PLC. In this article, there are many benefits to industries especially in order to support SME that can use local technology. Therefore, we can apply this research to the manufacturing process in Thailand for the future.

• The Research Journal of the Costume Culture
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• v.17 no.1
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• pp.177-188
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• 2009

SCM as the important marketing strategy enhance the firm's efficiency and compatibility in global market environment such as global outsourcing. Firms adopted SCM realized the need to evaluate precisely the performance of SCM. In spite of importance of SCM, there was not much intention and research to measure SCM performance in textile fashion industry. Therefore, the purpose of this case study was to measure performance of supply chain management in textile fashion business using BSC(Balanced Score Card) to measure not only financial perspective but also non-financial perspectives such as customer perspective, internal business perspectives, financial perspective, and innovation & learning perspective. The questionnaire developed by the reviews of the literature was adopted for this study. The results of this study showed that SCM performance was enhanced from the point of customer perspective(cost, quality, time, service), financial perspective(cash cycle time, inventory turn over, inventory obsolescence, return on asset, return on investment, capacity utilization), and innovation & learning perspective(cost for human resource management, service for human resources). But there was same performance level regarding internal business perspective(lead time, cost for manufacturing process, product quality control, productive flexibility for time, quantity, and variety). Therefore, we should keep close relationship and two way communication among supply chain members to promote better SCM performance.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.2
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• pp.8-14
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• 2008

Solid Rocket Motor(SRM) has advantages such as - high specific impulse, operational safety and simplicity in design and manufacturing process but thrust magnitude can't be controlled. For studying of pintle nozzle that can control the thrust magnitude of SRM, cold flow test and numerical analysis about needle type pintle shape were performed and results were presented in this paper. As the results of this study, pintle tip's shape and nozzle contour were important design parameters because thrust performance and variable thrust range of pintle nozzle depend on them. Especially, the thrust of needle typed pintle nozzle adopted in this test was predicted 13% higher than normal nozzle without pintle.

• Structural Engineering and Mechanics
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• v.6 no.6
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• pp.659-671
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• 1998

Exercise of complete control on all aspects of any manufacturing / fabrication process is very difficult, leading to uncertainties in the material properties and geometric dimensions of structural components. This is especially true for laminated composites because of the large number of parameters associated with its fabrication. When the basic parameters like elastic modulus, density and Poisson's ratio are random, the derived response characteristics such as deflections, natural frequencies, buckling loads, stresses and strains are also random, being functions of the basic random system parameters. In this study the basic elastic properties of a composite lamina are assumed to be independent random variables. Perturbation formulation is used to model the random parameters assuming the dispersions small compared to the mean values. The system equations are analyzed to obtain the mean and the variance of the plate natural frequencies. Several application problems of free vibration analysis of composite plates, employing the proposed method are discussed. The analysis indicates that, at times it may be important to include the effect of randomness in material properties of composite laminates.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.2
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• pp.33-38
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• 2013

In this study, both a finite element analysis and an experimental analysis are executed to investigate the mechanical characteristics of dielectric material effects on warpage. Also, viscoelastic material properties are measured by DMA and are considered in warpage simulation. A finite element analysis is done by using both thermal elastic analysis and a thermo-viscoelastic analysis to predict the nonlinear effects. For experimental study, specimens warpage of non-symmetric structure with body size of $22.5{\times}22.5$ mm, $37.5{\times}37.5$ mm and $42.5{\times}42.5$ mm are measured under the reflow temperature condition. From the analysis results, experimental warpage is not similar to FEA results using thermal elastic analysis but similar to FEA results using thermo-viscoelastic analysis. Also, its effect on substrate warpage is increased as core thickness is decreased and body size is getting larger. These FEA and the experimental results show that the nonlinear characteristics of dielectric material play an important role on substrate warpage. Therefore, it is strongly recommended that non-linear behavior characteristics of a dielectric material should be considered to control warpage of FCBGA substrate under conditions of geometry, structure and manufacturing process and so on.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.132-146
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• 2007

Constructing an effective production control policy is the most important issue in wafer fabrication factories. Most of researches focus on the input regulations of wafer fabrication. Although many of these policies have been proven to be effective for wafer fabrication manufacturing, in practical, there is a need to help operators decide which lots should be pulled in the right time and to develop a systematic way to alleviate the long queues at the bottleneck workstation. The purpose of this study is to construct a photolithography workstation dispatching rule (PADR). This dispatching rule considers several characteristics of wafer fabrication and influential factors. Then utilize the weights and threshold values to design a hierarchical priority rule. A simulation model is also constructed to demonstrate the effect of the PADR dispatching rule. The PADR performs better in throughput, yield rate, and mean cycle time than FIFO (First-In-First-Out) and SPT (Shortest Process Time).

• The Journal of Korean Institute for Practical Engineering Education
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• v.5 no.1
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• pp.20-27
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• 2013

The counter balancing is a technique to control a load which is acting to actuator when the load changes from a resistance state to over running state according to the structural change of the load for the case of lifting or carrying a heavy load in industrial site. Even though this technique is frequently used in industrial site, there is no widely known design procedure and educational equipment in home and abroad. Therefore, in this study a new idea was presented to develop an counter balancing educational equipment. The idea was realized through the process of system modeling and simulation, drawing out of design parameters, manufacturing of a prototype. Finally the usefulness of this developed educational equipment was demonstrated by experiments. It is expected that by using this equipment a big help would be given to students who should understand the counter balancing equipment which is frequently encountered in industrial site.