• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.205-206
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• 2012

A novel torrefaction process is suggested to improve energy efficiency and to produce high quality biomass fuel. Major developments for novel torrefaction process are as follows. To maximize the energy efficiency in heat transfer, flue gas is directly used for heat source in the torrefier. To accomplish the oxygen free environment in the torrefaction reactor, a burner is developed and it can be runned with fuel rich state. To use the calorific gases produced from torrefier, another burner is developed to combust them. In the test, the novel torrefaction process leads low energy consumption and the quality of torrefied fuel becomes better.

• Journal of Korean Society for Quality Management
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• v.23 no.3
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• pp.33-44
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• 1995

This paper presents an automated visual inspection system for the electronic parts manufacturing process. In this system, a statistical process control (SPC) method is integrated into the automated inspection method on a real time base. It shows how the collected data can be analyzed with the SPC to provide process information. Also presented are studies of subpixel image processing technology to improve the accuracy of parts measurements, and the cumulative-sum (CUSUM) control chart for fraction defectives. An application of the developed system to connector manufacturing process as a part of computer integrated manufacturing (CIM) is presented.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.305-310
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• 2004

The Hot Embossing Lithography(HEL) as a method for the fabrication of nanostructure with polymer is becoming increasingly important because of its simple process, low cost, high replication fidelity and relatively high throughput. In this study, we investigated the characteristics of hot embossing lithography as a nanoreplication technique. To grasp characteristics of nano patterning rheology by process parameters(embossing temperature, pressure and time), we have carried out various experiments by using the DVD(400nm pattern width) and Blu-ray nickel stamps(150nm pattern width). During the hot embossing process, we have observed the characteristics of the size effect. The quality of products made by hot embossing is affected by its cooling shrinkage. The demolding process at the glass transition temperature results in low quality because of the shrinkage of the polymer. Therefore, the quantification of the temperature condition is essential for the replication of high quality.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.354-359
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• 1994

On-line process control equipment for CO $_{2}$ laser cutting is unavailable for industrial application. The major part of the industrial cutting machines are regulated off-line by highly educated engineers. The quality inspection of the sample is visual and referred to different quality scales. Due to lack of automation potential laser users hesitate to implement the cutting method. The first step toward an automation of the process is development of a process monitoring system and the research is concentrated on the area of on-line quality detection during CO $_{2}$ laser cutting. The method bases on the detection of the emitted light from the cut front by photo diode. the signal from photo diode has been undertaken from Fourier analysis and statistical analysis. As a result, it is possible to estimate striation pattern according to beam travel speed.

• Proceedings of the KWS Conference
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• 1995.04a
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• pp.118-122
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• 1995

The hydraulic or pneumatic valve spools become essential as the important components on the production of automatic hydraulic or pneumatic machinaries as mechanical industry is developed rapidly. The machining precision is asked for manufacturing the valve spools. They could be unstable in the quality by the conventional arc welding and they have a lot of technical problems in manufacturing because their shapes are generally small. By the Precision casting process such as lost wax process, the production cost will be increased. But by the friction welding technique, they will be able to be made without such problems. Furthermore, there is a few study on friction welding of such hydraulic valve spool steels and in-process real-time weld quality evaluation technique by acoustic emission. So that, the final purpose of this study is 1) the development of design and manufacturing technique of hydraulic or pneumatic valve spool by optimizing of friction welding, and 2) the development of in-process real-time weld quality evaluation technique by acoustic emission.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.147-155
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• 2006

Recently, because of the rapid remarkable development of the digital media, contemporary society is continuously extending and changing over the limitation of the human recognition. But in the field of architectural form creation, a diagram used in the design process of the past is not enough to reflect a complication, contingent and multiple quality of these contemporary society. So, to reveal the rhizomorphous and non-hierarchial qualify of the contemporary digital network society, architecture became necessary to use the diagram with digital media which have various possibilities to present architect's abstract images that the diagram of the past couldn't do. Therefore, this study proposes that the process for creating architectural form with the digital diagram be a alternative to conquest the limits of contemporary architecture, so it present the complicate and contingent quality of contemporary society. Furthermore, it examines the quality and possibility of the diagram by understanding the creation and transformation of the digital diagram, and how to apply to the actual architecture process of the creating form.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.16-21
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• 2011

In machining operation, the quality of surface finish is an important factor for many turned products. In this paper, surface quality in turning machining considering angle variation has been investigated. To reach this goal, surface quality turning experiments are carried out according to cutting conditions with angle variation. The variable cutting conditions are cutting speed, feed rate and taper angle of workpiece. The surface roughness was measured and the effects of cutting conditions were analyzed by the method of analysis of variance (ANOVA). From the experimental results and ANOVA, it is found that a better surface roughness can be obtained as decreasing feed rate, increasing cutting speed. Taper angle variation has been more influenced by feed rate and cutting speed.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.37-46
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• 2003

This paper is to predict quality deterioration resulting from a caulking process of yoke which is a part of automotive steering system. The caluking is a plastic deformation process involving such as impact of high speed tool, contacts between part and fixtures and strain rate sensitivity of the part material. Elaborate application of finite element method is neccesary to calculate changes of part dimensions because they fall into a level of tolerances. Simple work hardening and strain rate sensitive model is proposed fur the material and applied for the simulation by using Abaqus which is able to cater for elastoplastic rate sensitive material and contacts. Numerical results of test models that represent tensile bar and tensile plate are compared with material data inputs. Dimensional changes for the yoke are calculated from simulations and compared to the mesurements and they show good agreement. The method presented here with the material model proved to be valuable to assess quality deterioration for similar metal forming processes.

• Journal of Korean Society for Quality Management
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• v.24 no.2
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• pp.44-53
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• 1996

This paper deals with the problem of selecting optimal wear limit and initial process mean in a wear-out process. Consider a material removal processing machinery where 1)there are deffective items by linear shift in the mean of the diameter of to be processed with varing process variance and 2)there can be any failure in the machine tools or to be processed. In the previous studies, the one is analyzed by 'Model of Producing Goods' in quality control area and the other, any failure, is analyzed by 'Model of Producing Services' in reliability area. We propose a new integrated maintenance model, considering the percent defective and the failure rate. A numerical example for the model is given.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.149-155
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• 2020

In the software industry of Korean Small and Medium-sized Enterprise(SME)s, the development process is often not mature. This may lead to failures in quality control and output management. As a result, the quality of the software can be degraded. To solve the problem, the software visualization technique, which is from the National IT Industry Promotion Agency Software Engineering Center can be applied. We have experienced with mentoring not only the visualization of software development process, but also various visualization process of SMEs. However, the existing software visualization method was difficult to install environment and its time cost was high. This paper proposes a software visualization environment through a cloud service along with a case of building a software visualization environment. We expect that this method will make it easier to build a visualization environment and improve the quality of SME software.