• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.491-495
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• 2009

This study was conducted to investigate the propagation characteristics of Cephalotaxus koreana by cutting, whose plant has been known to new anticancer treatments. The treatments of plant growth regulators, cutting media temperature and growing media were investigated to know the rooting ability of cuttings. For rooting formation affected by plant growth regulators and its concentration, The application of IBA 100 mg/L was most effective in all of the characteristics including rooting rate of 88.5%. The optimum media temperature by cutting was $24^{\circ}C$ (treatment IBA 100 mg/L, rooting rate 84.6%), predicting that greenwood cutting from June to July is most effective. VPPL (vermiculite+peatmoss+perlite 1:1:1(v/v/v)) showed the highest value in all of the characteristics including rooting rate of 68.5% for the effect of growing media on rooting formation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.1
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• pp.73-79
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• 2011

In this study, coring with diamond core drill on the sintered $Al_2O_3$ ceramic plate were carried out with different coring conditions such as various cutting speed and feed rate to evaluate their effectiveness on the wearing behavior of diamond tool and coring quality. The wearing rate of diamond core drill were getting better with increasing cutting speed and feed rate but the quality of cored hole were getting worse as increasing cutting speed and feed rate.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.1
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• pp.69-76
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• 1997

This paper deals with the machinability based on turning and drilling tests. The main conclusions obtained were as follows. (1) Turning : The roughness of Machined surface decreases with the increase of the rake angle of tools, and the tool wear becomes smaller with the decrease of the rake angle. When the feed rate becomes larger, the fracture of work material in the vicinity of the cutting edge occurs on a larger scale, eventually decreasing tool wear. (2) Drilling : Considering both tool life and productivity, it is reasonable to cut with the high cutting speed and feed rate. The tool wear increases with the increase of feed rate, and the tendency of feed rate on tool wear becomes stronger at the cutting speed $\geq$30m/min.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.202-208
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• 2003

This study carried out a cutting experiment on Duralumin A16061-76, which is light but strong and highly anticorrosive, so recently popular as a lightweight material, by changing cutting conditions and alternating 4 insert tips, and examined the effect of each insert tip on cutting force at certain cutting conditions, the measurements of the coarseness of processed surfaces roughness, and the chip workability. The 1311owing conclusions were drawn from the results. Cutting force for cutting tool is when insert tips were alternated at each cutting condition, the cutting force of cutting tools was highest then CBN tools were use(1 next by Ceramic tools, Cermet tools, and WC tools. Therefore, WC tools are considered most suitable for cutting Duralumin A16061-T6. Surface roughness as for the coarseness of surfaces according to insert tips applied to Duralumin A16061-T6 under the cutting condition of depth of cut below 1mm, feed rate below 0.24mm/rev and cutting speed over 100m/min the coarseness of material surface roghness appeared to be finest when WC tools were used, next by Ceramic tools, Cermet tools, and CBN tools.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.53-61
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• 1996

A clear understanding of the surface formation mechanism due to cutting is very important to help produce a good quality surface. Much of the roughness along the length of a bar being cut in a lathe can be explained in terms of macroscopic tool shape and feed rate. However, the roughness along the direction of cutting requires a different explanation. The formation of surface roughness is a problem in flow and fracture of materials in the vicinity of the tool edge. On a microscopic scale the cutting edge is rounded because it is impossible to grind a perfectly sharp cutting edge. Even if a perfectly sharp cutting edge were obtained it would soon become dull as a result of rapid breakdown and wear of the cutting edge. A research project is proposed in which in the main object is to model the surface formation mechanism due to cutting. The tool was assumed to be dull, that is, its edge has a finite radius. In order to study the effect of the radius of cutting edge on the surface formation, tools having different cutting edges were used. For orthogonal cutting experiment, cast iron and glass were chosen as brittle materials. Plowing forces acting in the cutting edge were estimated and its effect on the surface roughness was studied by observing the machined surface using optical microscope.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.20-26
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• 2013

This study focused on how it affects the surface roughness of work piece in cutting SCM415 steel, widely used steel in industry, by TiCN and TiN tools. Following conclusion was drawn from several experiments. The surface roughness of heat treated workpiece was better than that of non heat-treated materials. Moreover, the roughness of surface roughness(Ra 0.25) on feeding rate of 0.05 was better when it was in wet process, rather than dry process. As the feeding rate increases, TiCN coating tool shows better roughness of surface than TiN tool. Also, in heated treatment, TiCN coating tool shows the least straightness dimension deviation at feeding rate of 0.05, 0.15mm/rev, and concave-like R shape appears by the feeding rate orders of 0.05, 0.15, 0.1, 0.125 and 0.075mm/rev.

• Journal of Welding and Joining
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• v.28 no.6
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• pp.35-39
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• 2010

Generally, ceramic material is very difficult to machine due to high strength and hardness. However, ceramic material can be machined at high temperature by plastic flow as metallic material due to the deterioration of the grain boundary glassy phase. Recently, a new method was developed to execute cutting process with CBN cutting tool by local heating of surface with laser. There are various parameters in LAM because it is a complex process with laser treatment and machining. During laser assisted machining, high power results in reducing of cutting force and increasing tool life, but excessive power brings oxidation of the surface. The effect of laser power, feed rate, cutting depth and etc. were investigated on the life of cutting tool. Chips were observed to find out suitable machining conditions. Chips of SSN had more flow-types than HIPSN. It means SSN is easier to machining. The life of cutting tool was increased with increasing laser power and decreasing feed rate and cutting depth.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.807-813
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• 1986

The orthogonal cutting method of the nodular graphite cast iron in the lathe turning, whose matrix were formulated under two kinds of annealing conditions, has been experimentally studied and the results investigated. The various characteristics of machinabilities of the nodular cast iron, depending upon its matrix, have been obtained from the results as follows. (1) As depth of cut increases, the cutting ratio and the shear angles tend to slightly increase, and as the containing quantity of ferrite matrix increases, they slightly decrease. (2) As depth of cut increases, the cutting force increases in an approximate straight line, and as the containing quantity of ferrite matrix increases, they decreases and the decreasing rate is about 20-30%. (3) As the containing quantity of ferrite matrix increases, the friction force acting on the tool face decreases and the decreasing rate is about 34-40% in case of the lower depth of cut, but in case of the higher depth of cut the decreasing rate is very small. (4) Both shearing force and vertical force show a lineal increases, and according as ferrite matrix increases there is a decrease by 25% in shearing force and a 12-25% decrease in vertical force. (5) Shearing speed and chip flow speed keep almost a constant value irrespective of matrix.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.75-82
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• 2019

Few studies have been conducted regarding theoretical turning force modelling while considering cutting constant. In this paper, a new cutting force modelling technique was suggested which considers the specific cutting force coefficients for turning. The specific cutting force is the multiplication of the cutting force coefficient and uncut chip thickness. This parameter was used for experimental modelling and prediction of theoretical cutting force. These coefficients, which can be obtained by fitting measured average forces in several conditions, were used for the formulation of three theoretical cutting forces for turning. The cutting force mechanism was verified in this research and its results were compared with each of the experimental and theoretical forces. The deviation of force was incurred by a small amount in this model and the predicted force considering feed rate, nose radius, and radial depth shows a physical behavior in main force, normal force, and feeding force, respectively. Therefore, this modelling technique can be used to effectively predict three turning forces with different tool geometries considering cutting force coefficients.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.90-96
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• 1991

This experiment was carried out in order to estimate the recovery days of root and stubble to the days after cutting, and contribution of specific stubble weight on the regrowth was examined using the relationships between the dry weight of shoot and yield components, and regrowth parameters by the days after cutting. The varieties examined were Maprima, Manhattan, Tove, Peramo, Caliente, Tempo and P-2 grown under individual plant basis. The results are may be summarized as follows: 1. Dry weight of root and stubble were recovered up to 13.5 and 11 days after cutting, respectively. 2. Dry weight of shoot(regrowth parts+stubble) was affected significantly by the varieties, stages of regrowth and variety x stage of regrowth. 3. The variety with tiller weight type showed higher average productivity of shoot than those of the variety with tiller number type. 4. Absolute growth rate(AGR) of shoot was correlated significantly with regrowth parts, stubble, root and weight of a tiller at the early stage of regrowth(up to 12 days after cutting), and correlated with regrowth parts, stubble, weight of tiller and stubble area at the late stage of regrowth(up to 20 days after cutting). 5. Contribution of specific stubble weight to absolute growth rate of shoot was different between the stages of regrowth. Thus, regrowth parts per specific stubble weight(RP1SSbW) and weight of tiller per specific stubble weight(WT1SSbW) contributed to absolute growth rate of shoot at the early stage of regrowth, and efficiency of specific stubble weight(ESSbW), regrowth parts per specific stubble weight (RPISSbW) and weight of a tiller per specific stubble weight(WT1SSbW) contributed to absolute growth rate of shoot at the late stage of regrowth. 6. Regrowth utilization rate(RUR) was one of the useful regrowth parameter to indicate the regrowth potential of grasses.