• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.3
• /
• pp.133-140
• /
• 2004

Recently reduction of industrial products in size and weight has been increased by application of micro-drills in gadgets of high precision and a great interest of a micro-drilling has been raised. Due to the lack of tool stiffness and the chip packing, the micro-drilling requires not only the robust tool structure which has not affected by vibration but also effective drilling methods designed to prevent tool fracture from cutting troubles. This paper presents an optimum design shape of a 0.15 mm micro-drill associated with a new manufacturing process to improve the production rate and to lengthen the tool life and suggestions on the micro-drilling characteristic properties associated with the tool life and workpiece quality.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.2
• /
• pp.112-121
• /
• 2006

To evaluate the performance of ventilation system properly, the correlations among the ventilation rate, indoor air-quality and cooling/heating load should be analysed. In this study, simulation tool to analyze the performance of ventilation system was developed. The simulation tool is based on the TRNSYS and some modules to calculate concentration of pollutants with the operation of ventilation system and to decide the signal of ventilation system were newly developed in this study. And these modules coupled with building load and heating/cooling simulation modules. To verify the validity of developed simulation tool, comparison study between simulation and field study were accomplished. As results, the simulation tool developed in this study can be used to predict the performance of ventilation system with accuracy.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.6
• /
• pp.52-59
• /
• 2002

Resently, reduction of industrial products in size and weight has increased by the application of micro-drill for gadgets of high precision and gave rise to a great interest in a micro-drilling. Due to the lack of tool stiffness and the chip packing, micro-drilling requires not only the robust tool structure which has not affected by the vibration, but also the effective drilling methods designed to prevent tool fracture from cutting troubles. Firstly, this paper presents a optimum characteristic evaluation method of 0.15mm microdrill in consideration of new manufacturing processes for improving the product rate and extend the tool life, and secondly suggest between microdrilling characteristic properties of tool md evaluation of workpiece quality through experiment.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.2
• /
• pp.188-194
• /
• 2010

In this paper, the typical Synthetic Aperture Radar (SAR) image quality parameters and analysis method are defined, and the SAR image analysis tool is presented for SAR image evaluation. The structure of the developed SAR image analysis tool consists of four key modules; point target analysis (PTA) module, distributed target analysis (DTA) module, ambiguity analysis (AMA) module, and NESZ analysis (NESZA) module. The developed tool is able to extract the various SAR system parameters from standard SAR product format files. Based on these extracted system parameters, typical SAR image quality parameters are derived from SAR image data.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.2
• /
• pp.185-198
• /
• 1995

The development of automated quality evaluation tool is desperately needed to decrease the cost of maintenance, to measure quality of source program in developing course for the purpose of developing high quality software. Main goal in this paper is to develop the automated tool for software quality evaluation related with high quality and high reliability of software. In this paper, we proposed the four software quality model to evaluate software quality; functional -size model, understandability model, complexity model and object-oriented model. Also, we made a scanner and a parser to analyze the c and C＋＋ source program and to produce the metrics and function value. The measurement value is statistically analyzed for the distribution of the measurement value. we can extracted the characteristics of measurement value and this one is assisted to make scores of software quality evaluation. Finally, we made a software quality evaluation tool to support software evaluation activities.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.10
• /
• pp.72-79
• /
• 2021

A circular saw is an effective tool for cutting glass and carbon-fiber hybrid composites. This study investigated tool wear and cut quality when reusing saw blades. The carbide saws wear four times faster than the new ones, and polycrystalline diamond (PCD) is very resistant to tool wear, except at the end of its lifespan. The cut cross-section quality is affected by the blade type, tool wear, and spindle speed. Alternate top bevel (ATB)-type blades are suitable for cutting fiber-reinforced plastics, but triple-chip grind (TCG)-type blades are unsuitable because they cause fiber-pullout defects. Tool wear and low spindle speeds increase the occurrence of arc scratches, due to the rear saw blade. A microscopic examination showed that the burr, which is a mixture of fiber chips and epoxy matrix, was bonded on top, and glass-fiber delamination occurred on the bottom glass-fiber-reinforced polymer (GFRP) surface.

• Design & Manufacturing
• /
• v.16 no.3
• /
• pp.39-43
• /
• 2022

In this study, we designed an vibration cutting tool that can achieve improvements such as low cutting force, interrupted chip evacuation and better surface quality of cutting performance to obtain high-quality surface roughness and improvement of tool wear, which is an issue in the machining of high-hardness mold steel. Among the resonance frequency modes of the vibration cutting tool, the bending mode was used to maximize the driving amplitude of the vibration tool tip, and the resonance frequency was confirmed through the finite element method. After measuring the actual resonant frequency of the designed tool using an optical fiber sensor, the cutting force and machining surface of vibration cutting and conventional cutting were compared and analyzed in the turning process of high hardness mold steel (STAVAX). As a result of the experiment, the cutting force was reduced by about 20 % compared to the conventional cutting process, and the surface roughness was also improved by about 60 %. This study suggested that the tool wear and surface quality of high-hardness steel can be improved through the vibration cutting method in the machining of high hardness mold steel.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.3
• /
• pp.8-13
• /
• 2020

Carbon fiber-reinforced plastics (CFRPs) are extremely strong and light fiber-reinforced plastics containing carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and rigidity are required, such as in the aerospace, automotive, and ship superstructure industries. In CFRP drilling, the tool performance greatly varies depending on the tool shapes, cutting conditions, and diamond coating. This study developed a new type of tungsten carbide drill with multi-blade edges to evaluate the surface quality of CFRP materials according to the coating thickness of diamond-coated drills. Experiments on tool wear, surface roughness, and burr formation were conducted. The bore exit quality of a 12 mμ -coated drill was better than that of a 6 mμ -coated drill. The superior effects of the 12 mμ -coated drill and the good surface quality of CFRP were also demonstrated.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.5
• /
• pp.59-65
• /
• 1998

In order to utilize the information of well-know grinding database or grinding machine characteristics, a database needs to be designed by considering the delicate property of the machine tools for the high precision and quality of the demanding specification. Among the machine tools for the high precision and quality of the demanding specification. Among the machine tools, machining conditions of the grinding are various and knowledge repeatance obtained form the grinding process are less credable. therefore it is desirable for database, which is used to set the grinding conditions, to utilize the maximum machine tool capability. The present paper studied on the occurance limit of chatter vibration and burn considering the characteristics of machine tool. And also basic experiments were performed to establish the optimum grinding conditions which could maximize the grinding efficiency.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.264-268
• /
• 2003

Recently reduction of industrial products in size and weight has been increased by application of micro-drills in gadgets of high precision and a great interest of a micro-drilling has been raised. Due to the lack of tool stiffness and the chip packing, the micro-drilling requires not only the robust tool structure which has not affected by vibration but also effective drilling methods designed to prevent tool fracture from cutting troubles. This paper presents an optimum design shape of a 0.15 mm micro-drill associated with a new manufacturing process to improve the production rate and to lengthen the tool life and suggestions on the micro-drilling characteristic properties associated with the tool life and workpiece quality.