• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1551-1554
• /
• 2005

The Titanium has many superior characteristics Which are specific strength, heat resistance, corrosion resistance, organism compatibility, non-magnetic and etc. and their quantity are abundant. this study performed turning operation of Ti-6Al-4V alloy using the TiAlN Coate Tool which treated PVD (Physical Vapor Deposition). Experimental works are also executed to measure cutting force, chip figuration and surface roughness for different cutting conditions. As a result of study. Tool wear was serious at over 100m/min of cutting speed and cutting condition was excellent at 1.0mm of cutting depth.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2004.11a
• /
• pp.233-236
• /
• 2004

An experimental study was conducted to evaluate characteristic variation of diluted engine oil by diesel fuel and its effects on engine components. Especially, engine oil was made to have $15\%$ fuel content. To predict existing diesel fuel content in engine oil after test was used the viscosity calibration curve. About $54\%$ percent of diesel fuel in diluted engine oil was distillated by various paths related to reciprocating motion of piston and the rest diesel fuel plays an important role for decreasing engine oil viscosity. Test results show that lowered engine ell viscosity by diesel fuel dilution become a reason of increasing engine elements wear, Therefore, this caused the quantity of blow-by gas to increase and main gallery pressure to decrease.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.95-100
• /
• 2001

Recently, coated milling cutters are widely used for improving the productivity of cutting processes through high speed cutting and longer tool life. In metal cutting, cutting force increase rate is important factor to diagnose the cutting conditions because the amount of tool wear directly influences the cutting forces. As the cutting length increases, the worn cutter increases the cutting forces. In this study, the effect of coating process of end milling cutter on the cutting performance, especially on the cutting force increase rate, is investigated. The results acquired through the cutting test measuring cutting force increase rate show that not only the injection quantity of $N_2$ and Ar but also mean temperature influence the cutting force increase rate during the end milling process.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.3 no.4
• /
• pp.81-87
• /
• 2004

The titanium has many superior characteristics such as specific strength, heat resistance, corrosion resistance, organism compatibility, non-magnetic and etc. and their quantity are abundant. This study performed turning operation of Ti-6Al-4V alloy using the TiAlN coated tool which was treated with PVD. Experimental works were also executed to measure cutting force, chip figuration and surface roughness for different cutting conditions. As a result of study, tool wear was serious at the condition over 100m/min of cutting speed. The excellent cutting condition of cutting depth was at 1.0mm.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.451-456
• /
• 2004

The Titanium has many superior characteristics Which are specific strength, heat resistance, corrosion resistance, organism compatibility, non-magnetic and etc. and their quantity are abundant this study performed turning operation of Ti-6Al-4V alloy using the TiAlN Coate Tool which treated PVD (Physical Vapor Deposition). Experimental works are also executed to measure cutting force, chip figuration and surface roughness for different cutting conditions. As a result of study. Tool wear was serious at over 100m/min of cutting speed and cutting condition was excellent at 1.0mm of cutting depth.

• The Research Journal of the Costume Culture
• /
• v.15 no.1 s.66
• /
• pp.169-178
• /
• 2007

The purpose of this study was to compare consumers' post acquisition behavior by analyzing the influence of familiarity of jeans, and pursued image. The data was collected by using survey, three stages of pre-tests, and main survey conducted in the U.S and Korea. A total of 520 participants from each country(260 males and 260 females) was used. The results of this study is as follows. Familiarity of jeans and pursued image of jeans wear were compared between Korean and American students. As a result, there was difference between the countries on familiarity that the U.S showed higher familiarity, frequence of wearing and owned quantity. Pursued image was consisted of unique factor and activity factor and Korean students showed higher score on pursuing individualistic image. The results of this study would provide marketing strategy for fashion marketers of global jean brands.

• Proceedings of the KWS Conference
• /
• 1996.10a
• /
• pp.186-190
• /
• 1996

Laser cladding is a technique for modification on surface in materials. This study describes a laser cladding equipment design and the results of laser cladding nickel on rolled steel for general structure. The laser clsdding equipment designed to consider continuous supply, a fixed quantity. The material used MC plastic. Laser cladding condition is found out by processing parameters. The experiment advanced to suppy substrate with powder. The substrate is rolled steel for general structure(KS D 3503) and powder is using the nickel powder for the corrosion resitance, wear resistance and surface hardness of materials. When the substrate travel on X-Y table, laser beam irradiates to prevent from oxidize with shielding gas on it. The obtained specimens measure the victors hardness test. For the research laser cladding results make a comparative study the microstructure.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.6
• /
• pp.111-118
• /
• 2014

Aluminum lithium alloys are new materials developed for lightweight aircraft parts. However, as compared with conventional aluminum alloys in high-speed machining, problems such as tool wear, machining distortion, and cutting ability arise. This study presents the machining distortion characteristics of an Al-Li alloy wing tip in relation to the cutting heat in high-speed machining. A machining experiment was conducted with high-speed machining equipment for an evaluation of the machining distortion characteristics, with each machining stage temperature change of the workpiece machining surface, and the inside and outside temperature changes of the equipment measured. By measuring the amount of distortion of the workpiece before and after machining, the cutting heat was analyzed with regard to its effect on machining distortion in the product.

• Korean Journal of Human Ecology
• /
• v.10 no.3
• /
• pp.275-290
• /
• 2001

The purpose of this study was to investigate the transition of clothing behavior and clothing consumption pattern of college students in Choong Nam province. 75 subjects were surveyed in 1995 and 2000. For statistical analysis, $X^2$-test were used by SPSSWIN program. The results of this study were as follows. 1. Number of clothing showed significant difference according to year and the number of coat and formal wear increased in 2000 compared with 1995. 2. Clothing consumption pattern showed significant difference according to year. College students purchased on sale more frequently and preferred more expensive clothes in the year 2000 compared with 1995. 3. Contentment for clothing behavior showed significant difference according to year and the extent of contentment decreased as years go by. 4. Number of clothing showed significant difference according to sex and female students had more clothes than male students, but the difference between male and female decreased as years go by from 1995 to 2000. 5. Clothing consumption pattern showed significant difference according to sex and female students purchased ell sale more frequently than male students, but the difference between male and female decreased as years go by. 6. Contentment for clothing behavior showed significant difference according to sex, but female students described to not adequate the quantity of feminine style wear and the interest in fashion of male students was increased as years go by.

• Geomechanics and Engineering
• /
• v.34 no.1
• /
• pp.103-113
• /
• 2023

This study focused on understanding the relationship between the design of a tunnel boring machine disc cutter ring and its rock-breaking efficiency, as well as the applicable conditions of different cutter ring types. The discrete element method was used to establish a numerical model of the rock-breaking process using disc cutters with different ring types to reveal the development of rock damage cracks and variation in cutter penetration load. The calculation results indicate that a sharp-edged (V-shaped) disc cutter penetrates a rock mass to a given depth with the lowest load, resulting in more intermediate cracks and few lateral cracks, which leads to difficulty in crack combination. Furthermore, the poor wear resistance of a conventional V-shaped cutter can lead to an exponential increase in the penetration load after cutter ring wear. In contrast, constant-cross-section (CCS) disc cutters have the highest quantity of crack extensions after penetrating rock, but also require the highest penetration loads. An arch-edged (U-shaped) disc cutter is more moderate than the aforementioned types with sufficient intermediate and lateral crack propagation after cutting into rock under a suitable penetration load. Additionally, we found that the cutter ring wedge angle and edge width heavily influence cutter rock-breaking efficiency and that a disc cutter with a 16 to 22 mm edge width and 20° to 30° wedge angle exhibits high performance. Compared to V-shaped and U-shaped cutters, the CCS cutter is more suitable for soft or medium-strength rocks, where the penetration load is relatively small. Additionally, two typical case studies were selected to verify that replacing a CCS cutter with a U-shaped or optimized V-shaped disc cutter can increase cutting efficiency when encountering hard rocks.