• Structural Engineering and Mechanics
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• v.65 no.2
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• pp.203-211
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• 2018

This paper introduces the development process of NCC(New Concrete Cutting) system and analyzes first verification test. Based on the first verification test results, some problems of NCC system have been newly modified. We carry out the second verification test. We tried to verify cutting performance and dust control efficiency of NCC system through the cutting test of concrete bridge piers. In particular, this verification test strives to solve the problem of concrete dust, which is the biggest problem of dry cutting method. The remaining dust problems in cutting section tried to solve through this verification test. This verification test of the NCC system shows that the dust problem of dry cutting method is closely controlled and solved. In conclusion, the proposed NCC method is superior to the dry cutting method in all aspects, including cutting performance, dust vacuum efficiency and cooling effect. The proposed NCC system is believed to be able to provide eco-friendly cutting technology to various industries, such as the removal of the SOC structures and the dismantling of nuclear plants, which have recently become a hot issue in the field of concrete cutting.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.242-250
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• 2010

For economical and environmental reasons, the aim of this research is hence to monitor the cutting conditions with the dry cutting, the wet cutting, and the mist cutting to obtain the proper cutting condition for the plain carbon steel with the ball end milling based on the consideration of the surface roughness of the machined parts, the life of the cutting tools, the use of the cutting fluids, the density of the particles of cutting fluids dispersed in the working area, and the cost of cutting. The experimentally obtained results of the relation between tool wear and surface roughness, the relation between tool wear and cutting force, and the relation between cutting force and surface roughness are correspondent with the same trend. The phenomena of surface roughness and tool wear can be explained by the in-process cutting forces. The models of the tool wear with the cutting conditions and the cutting times are proposed to estimate the tool cost for the different cooling strategies based on the experimental data using the multiple regression technique. The cutting cost is calculated from the costs of cutting tool and cutting fluid. The mist cutting gives the lowest cutting cost as compared to others. The experimentally obtained proper cutting condition is determined based on the experimental results referring to the criteria.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.77-81
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• 1989

This experiment was conducted to elucidate the changes of dry matter production in permanent pasture and its relation with relative yield of the 1st cutting, regrowth capacity, and persistance of orchardgrass sward, based on the data of preceeding The results were summarized as follows; 1. Relationship between relative yield of the 1st cutting and regrowth capacity were changed by the times of established pasture. Thus, the relative yield of the 1st cutting have negative significant correlation (P < -0.001) with regrowth capacity. 2. Regrowth capacity(RC) was positively significant correlations with the dry weight of plant (DW/pl.), number of tillers per plant (NT/pl.), plant size(PS) and distance between adjacent plants (DIS) of the 1st cutting. Also, regrowth capacity(RC) was positively correlations with the dry weight of plant (DW/pl.), number of tillers per plant (NT/pl.), stubble diameter(DIA), stubble area(SB), plant size(PS) and distance between adjacent plants(D1S) of the 2nd cutting. 3. The coefficients of regression of the 1st cutting showed a tendency to slightly decrease, on the other hand, the 2nd cutting and total yield were tended to increase by the times of established pasture. 4, Between the regrowth capacity and persistency were may deeply concerned to the changes of dry matter production in permanent pasture. 5. The process of dry matter production in permanent pasture can be shown in following diagrams.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.238-244
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• 2004

This research conducted milling tests to study effects of cutting environment conditions of ball end milts on the characteristics of high speed milling cutting process. KP4 steels and STD11 heat treated steels were used as the workpiece and WC-Co ball end mill tools with TiAIN coated were utilized in the cutting tests. Dry cutting without coolant and semidry cutting using botanical oil coolant by the MQL(Minimum Quantity Lubricant) device were conducted. Cutting forces, tool wear and surface roughness were measured in the cutting tests. Results showed that MQL spray cutting of KP4 and hardened STD11 specimens produced better surface quality and wear performance than dry cutting did.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.19-24
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• 2003

Recently, various efforts to make more speedy and precision machine tool to improve productivity and also various efforts to solve environmental problem are going on, so that dry cutting in manufacturing industry, which needs environmental conscious design and development of manufacturing technique, is becoming a very important assignment to solve. Because dry cutting does not use cutting fluid, we need other methods that can be used instead of cutting fluid, which does cooling, lubricating, chip washing, and anti-corrosion. Especially, because turning is a continuous work, the consideration of tool life and surface roughness due to continuous heat and poor lubrication is important. The purposes of this paper are the consideration of how well the compressed air can work instead of cutting fluid, and also the development of the method to select the optimum machining condition by the minimum numbers of experiments through the Taguchi method.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.737-741
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• 1996

Dry matter yield of reed canarygrass was investigated in uncultivated rice paddy in Korea, and an attempt was made to estimate the most economic and efficient cutting frequency and rates of nitrogen (N) fertilization, for increased production of reed canarygrass. Total dry matter yields of reed canarygrass per year were 7.4-15.7, 8.5-16.1, and 7.5-13.4 tons/ha in 3, 4, and 5 cutting frequencies, respectively, and over the N treatments of 0-120 kg N/ha/cut. When cut 3 or 5 times annually, the 2nd cut produced the highest proportion of total yield at 38.4 and 33.0%, respectively, when cut 4 times the 3rd cut was highest (38.3%). The ranges of economic N level, limiting N level and efficiency of dry matter production were 243.3-293.0, 387.2, and 14.6 kg DM/kg N, respectively. These indicators were particularly low for the 5 cutting frequency possibly because of the unusually high temperature in the summer season. The best cutting frequency for the dry matter production of reed canarygrass in 1994 was 3 per year because of the higher efficiency of dry matter production.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.129-132
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• 2003

Used cutting fluid from machining processes is harmful to both environment and human health. Chemical substances that provide the lubrication function in the machining process are toxtc to the environment if the cutting fluid is released to soil and water and caused serious health problems to workers who are exposed to the cutting fluid in both liquid and mist form. Recently. cost of using cutting fluid is increasing as the number and the extensiveness of environmental protection laws and regulations increase. Therefore, the use of cutting fluid in machining processes place an enormous burden on manufacturing companies to cover the additional costs associated with their use and protection of our environment. Current trends in manufacturing are focused on minimizing or eliminating the use of metalworking fluids in machining processes. And the increased costs for the disposal of waste products (swarf, coolants and lubricants), especially in industrially developed countries, has generated interest in dry machining. A variety of new techniques are testimony that new technology has rationalized further efforts to research and implement dry machining processes. This paper presents the developed equipment, the process optimization and the applications in the field of surface grinding for the new cryogenic dry machining using a compressed cooling air. The investigated new machining process method shows many advantages compared to conventional techniques with cutting fluid.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.31-36
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• 2001

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.33-42
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• 1996

In this study, the adequate cutting frequency and level of cattle slurry nitrogen application were investigated for the production of Reed canarygrass. Higher relative dry matter yields were recorded in 2nd cut in 3 cutting frequency, 3rd cut in 4 cutting frequency and 4th cut in 5 cutting frequency respectively. With no fertilization, mean dry matter yields per year were 6.4~7.5 tons/ha and the highest yield appeared in 3 cutting frequency. The increased application of cattle slurry nitrogen resulted in the increased dry matter yield. Significantly higher dry matter yields than that of no fertilization were recorded in fertilization of 180 kg cattle slurry-N per year in 3 cutting frequency, 120 kg in 4 cutting frequency and 300 kg in 5 cutting frequency respectively. Efficiency of dry matter production with cattle slurry nitrogen application (kg DM/kg N) was higher in 120 kg N, 30 kg N and 90 kg N/ha/cut in 3, 4 and 5 cutting frequency respectively. In each cutting frequency, the higher efficiency of dry matter production appeared in 1st cut in 3 cutting frequency, and 2nd cut in 4 and 5 cutting frequency respectively. Economic slurry N level (kg/ha) was 462.7~525.3 kg/ha in 3 cutting frequency, and 353.1~423.2 kg/ha and 380.1~424.4 kg/ha in 4 and 5 cutting frequency respectively.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.36-44
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• 2000

In this paper drill shape and cutting conditions for environmentally conscious dry drilling of A319 Al-alloy are studied by experimental method. The experiment is planned with Taguchi's method that is based on the orthogonal array of design factors. The result is summarized as follows (1) Drill geometry optimization can increase the number of holes in dry drilling and also large helix angle and large point angle are desirable in dry drilling. (2) It is found that cutting conditions that is cutting speed and feed rate are closely related to the drill geometry(3) For dry drilling of Al-alloys drill shape and cutting conditions are selected and tested by experimental method. But it is found that the perfect dry drilling is difficult because of the machining characteristics of Al-alloys and so new machining method such as minimal lubricant application is required.