• Fashion & Textile Research Journal
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• v.17 no.6
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• pp.996-1003
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• 2015

This study aims to examine the effects of the cutting amount at the waistline on the jacket appearance evaluation and movement functionality, and to suggest a proper waistline cutting amount when designing the men's casual jacket for those in their 30's. The researchers prepared 4 kinds of experimental jackets varying the waistline cutting amount: 0.0cm, 0.5cm, 1.0cm, and 1.5cm. The results of the study are as follows: Regarding the front view appearance, the jacket with the 0.5cm cutting amount achieved the highest score (6 out of 9). On the side view and the back view, there was no meaningful difference. However, the jacket with 0.5cm cutting amount achieved the highest score (4 out of 5). On the other hand, on the movement functionality, there was small statistical difference; the 1.5cm experimental jacket received the highest score in the most areas. This is resulted because if the cutting amount was increased, equally with the V-zone area which gives room for movements. This result showed the difference from the previous research of men in their 20’s,where 0.0cm achieved the highest test score for both appearance and movement functionality. Therefore, this study suggests using the 0.5cm and 1.5cm for the waistline cutting amount; for the jacket appearance 0.5cm is the best while the 1.5cm is better for the movement.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.591-602
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• 2020

Several alternative rock-cutting concepts, which are modified from the conventional ones, have been developed lately. Of the concepts, undercutting is one of the latest technologies. In this study, as a fundamental study on the undercutting technique, the rock-cutting mechanism and important parameters of the undercutting were introduced. This study built up cutting test system for evaluating the cutting performance of an actuated undercutting disc cutter (ADC), and carried out a series of cutting tests under different cutting parameters of ADC. The characteristics of cutter forces obtained from ADC rock-cutting tests were analyzed. The both average and peak values of the three directional cutter forces were linearly increased with the increases of linear velocity, penetration depth in vertical direction and eccentricity of ADC.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.424-429
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• 2004

The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation for HMC is not sufficiently performed and the efficient cutting conditions can't be selected, a peat loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented by the analysis of acceleration in idling. The Machinability for the TiA1N coated flat end mill and STD11 (H$\sub$R/C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions . The resonance spindle speed is identified through the tool wear and natural frequency test.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.94-99
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• 2002

KS and ISO have proposed several evaluation methods of conventional machine tools. Even though the accuracy of the tools can be evaluated with these methods, there are still no proper evaluation methods of high speed machining. Because it is hard to evaluate characteristics of high speed machining such as decrease of cutting temperature, cutting force, and reduced machining time. Therefore, new evaluation method for high speed machine should be developed. In this paper, several shapes of model have been proposed to evaluate cutting accuracy of high speed machine.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.14-20
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• 1998

Cutting fluid is a factor which has big effects on both machinability and environment in machining process. The loss of cutting fluids may be reduced by the optimization of machining parameters in process planning. In this study, the environmental impact of fluid loss is analyzed. The fluid loss models in milling process are constructed with the machining parameters. The models are utilized to obtain the optimal machining parameters to minimize the fluid loss. The factors with significant effects on the fluid loss are analyzed by ANOVA test. Finally, optimal parameters are suggested considering both machining economics and environmental impact. This study is expected to be used as a part of a framework for the environmental impact assessment of machining process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.2
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• pp.3-9
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• 2006

HSM(High-speed Machining) is widely used in rapid manufacturing of precision products and molds of various materials. Improvement in cutting efficiency is one of the important subjects in the HSM process. To analyse the dynamic behavior during a very short cutting time, the computational analysis code, LS-DYNA3D, was employed for the simulation of the mechanism of HSM for aluminium 7075. This cutting mechanism includes some difficult points in simulation, for example, material and geometrical non-linearity, high-speed dynamic impact, contact with friction, etc. In this paper, a finite element model considering the strain rate effect is proposed to predict the cutting phenomena such as chip deformation, strain and stress distributions, which will help us to design the HSM process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.6
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• pp.36-43
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• 2003

In machining of ceramic materials, they are very difficult-to cut materials because of there high strength and hardness. Machining of ceramics are characterized by cracking and brittle fracture. Generally, ceramics are machined using conventional method such as finding and polishing. However these processes are generally costly and have low MRR(material removal rate). This paper focuses on determining the optimal levels of process parameters for products with CNC machining center. For this purpose, the optimization of cutting parameters is performed based on experimental design method. A design and analysis of experiments is conducted to study the effects of these parameters on the surface roughness by using the S/N ratio, analysis of ANOVA and F-test. Cutting parameters, namely, cutting speed, feed and depth of cut are optimized with consideration of the surface roughness.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.1
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• pp.53-62
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• 1990

High speed and heavy cutting performed for improving the surface quality and productivity, are often prevented due to chatter phenomena. Chatter is a violent relative vibration between workpiece and tool in machining of metals, and is an important limiting factor of production rate and surface quality, and reduces the tool life and the dynamic performance of machine tool itself. In this study, in order to suppress the chatter, a modified tool-post combined with the spring and damper was designed and used in the actual cutting test. The results of this study are summerized as follows; The spring and damper adopted in the modified tool-post have the suppressing effects of chatter, and there exists an optimum combination between spring constant and damping ratio.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.926-931
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• 2012

Rotary bar was cutting tool being in use for deburring scale after welding metal and for eliminating sharp edges. It was necessary to develop exclusive 6-axis machine being possible to process machining continuously for making an cutting edge of rotary bar and to revise easily machining program. This study aimed at the structural analysis of strength according to the configuration of new made 6-axis machine and at the machining accuracy and durability of rotary bar. As a result of test, the runout of new rotary bar manufactured out of 6-axis machine was decreased from 0.385 mm to 0.027mm extensively than old one. And good cutting ability and durability was obtained equal quality compared with imported products.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.6
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• pp.630-635
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• 2014

This study aims to develop a PZT-driven depth adjustment device with a flexure hinge and to investigate its static/dynamic characteristics. This device will be applied to rapidly and accurately trace a flat surface with slight waviness of up to several hundreds of micrometers in magnitude. One typical example is to cut a film coated on a steel plate. A depth control system composed of PMAC, PZT/PZT amplifier, flexure hinge/knife, and laser displacement sensor is implemented on a desktop three-axis machine and an actual cutting test is conducted on a steel workpiece with a sinusoidal-wavy surface. It is verified that the dynamic characteristics of the device limit the maximum cutting speed and depth precision.