• Korean Journal of Poultry Science
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• v.8 no.1
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• pp.25-30
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• 1981

This study was conducted to find the method that the least-cost formula can be determined thus allowing a better keeping of raw material supplies under the constraints having to be used some raw materials that are either in limited supply or for other reason in restricted use. In this study, it was considered that three kinds of feed were produced under limited supply of six kinds of raw materials, and data for the analysis were collected from a feed mill in southern part of Korea. According to the result of this study, it was proved better to determine the least-cost formula as the multi-mix problem than as the simple least-cost problem when more than two kinds of feed were produced wilt limited supply of raw materials.

• Journal of the Korean Society for Precision Engineering
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• v.6 no.3
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• pp.24-31
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• 1989

By use of the machining center, step-feed drilling was operated under the variety of conditions as to materials, tools and cutting conditions. Based on this study the following conclusions can be drawn : 1) The cutting force can be diminished by utilizing the step-feed working; specially the most effective was it for the brass among the carbon steel, the brass, and the cast iron. 2) Tool life can be enlarged more than double when three-step-feed working is used. 3) For the constant cutting-depth(30mm), the most optimal number of stepping is 3.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.3
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• pp.43-50
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• 1998

In the use of CNC machine tool, the unmanned production system has been growing in the manufacturing field. Thus, it is necessary to monitor adequate tool fracture during the cutting process efficiently. This experimental study is intended to investigate the development of flank wear in sysnchronous turning of differential materials(Aℓ/GC) which is used in industrial application and it is acknowledged as a machine to difficult material. In cutting process change of velocity, change of feed, and change of depth of cut were investigated on the effect of flank wear, and slenderness ratio is also investigated. The conclusions of this paper are summarized as follows; 1.Under the high cutting speed condition, the flank wear is affected by the feed and depth of cut. but the influence of feed on the flank wear is larger than the depth of cut and that is reduced when the velocity is low. 2.Under the high cutting speed, as the smaller slenderness ratio is, the shorter tool life is under the lower cutting speed, the effect of slenderness ratio on the flank wear is low. 3.Using the characteristics of cutting force, the flank wear of a tool can be detected 4. Investigating the development of flank wear, there are almost no differences between the characteristics of cutting force and feed force. Finally, these data from the differntial materials cutting process will be used in the basic field of precision and economic cutting process.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.133-147
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• 2005

In order to investigate applicability for 2,2,2-trifluoroethyl methacrylate (TFEMA) produced by esterification of 2,2,2-trifluoroethanol(TFEA) and methacrylic acid(MA) using pervaporation membrane, poly(vinyl alcohol) (PVA) composite membranes were prepared with glutaraldehyde(GA) onto porous polyethersulfone(PES) support. The degree of crosslinking and thickness of PVA coating layer were analyzed by swelling test and SEM(scanning electron microscopy), respectively. Pervaporation test was done with two feed mixures; TFEA/water, MA/water. The pervaporation data were obtained as a function of content of crosslinking agent, feed composition, and operating temperature, respectively. In case of TFEA-water(90/10 wt%) feed mixture at $80^{\circ}C$, the optimized membrane showed the high permeation flux of 1.5 $kg/m^2hr$ and separation factor of 320. In case of MA-water(90/10 wt%) feed mixture, the membranealso showed high permeation flux of 2.3 $kg/m^2hr$ and separation factor of 740 in same conditions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.192-197
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• 2002

In this study, examined the cutting characteristics of alumuminum alloy AC8A-T6 that is used to present car piston materials. And in been holding materials machining empirically escape as result that experiment comparison changing the cutting speed and feed on various condition to choose efficient machining condition. The following results can be summarized from this research. 1. As the cutting speed decreased, principal cutting force and thrust cutting force is increased, and reason that cutting force interacts greatly in the low cutting speed is thought by result by BUE's stabilization. 2. The feed speed and cutting speed increase, friction factor is decrescent and the cause appeared the thrust cutting force is fallen than cutting force relatively because chip flow according to increase of the feed rate is constraint. 3. Though specific cutting resistance grows cutting area and the feed rate are few, the cause was expose that shear angle decreases by rake face of tool gets into negative angle remarkably as wear of a cutting tool or defect part of workpiece is cut. 4. Cutting speed do greatly depth of cut is slow, surface roughness examined closely through an experiment that becomes bad, and know that it can get good surface that process cutting speed because do feed rate by 0.1mm/rev low more than 250m/min to get good surface roughness can.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.768-778
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• 1993

The system is designed for the production and processing of feed, fertilizer, sugar , and grain. It can be used to weigh and transport automatically their pellet, power or nonstickness materials. In this system, we use discontinuous totalising automatic weighing instruments to weigh materials. It is a closed-cycle control system controlled by industrial controlling computer STD bus. The system used for processing grain and feed can improve the quality of products , carry out scientific management, increase productivity and decrease the intensity of labour

• Transactions of Materials Processing
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• v.8 no.5
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• pp.465-470
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• 1999

Many researchers have, nowadays, studied on spinning which can produce highly qualified products by CNC spinning machine equipped with hydraulic devices. The products have continuous metal flow which improves fatigue life, yield point, tensile strength and hardness. This study is to investigate the influence of various working conditions on the spinnability of cylindrical cups such as feed rate(ν), feed pitch(p), angle of roller holder(α), and the inclination angle of first roller path. Through experiments the feed rate of (0.4∼0.7) mm/rev was shown to give the drawing ratio of 2.5 when the angle of roller holder was 5°, However, by increasing the angle of roller holder from 5°to 20°, the range of feed rate which can produce deeper cups became wider and the spinnability was also improved. The optimum working conditions, for the maximum formability of aluminum sheet metal as well as dimensional accuracy of spun cups, are presented and discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.940-946
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• 2015

The turning clearance angle changes the machining characteristics. In this study, three workpiece materials, machine structural carbon steel, chrome-molybdenum steel and stainless steel, were examined. The experiments revealed how the features of selected materials changed when they were processed with machining operation. To find the surface roughness of workpiece materials, the workpiece materials, which have a higher tensile strength, showed a much better surface roughness in the surface roughness tester. Moreover, the process feed rate was compared between 0.07 mm/rev and 0.10 mm/rev. When the process feed rate was 0.07 mm/rev, the surface roughness has superior results without reference to the quality of the materials. According to this research on the turning clearance angle, the best roughness value was observed when the quality of the materials were $0.9^{\circ}$, whereas the worst roughness was observed when quality of the materials was $0.3^{\circ}$.

• Corrosion Science and Technology
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• v.18 no.1
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• pp.1-7
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• 2019

To find proper lathe machining parameters for SA182 Grade 304 stainless steel (SS), six kinds of samples with different machining surface states were prepared using a lathe. Surface morphologies and microstructures of near surface deformed layers on different samples were analysed. Surface morphologies and chemical composition of oxide films formed on different samples in simulated primary water with $100{\mu}g/L\;O_2$ at $310^{\circ}C$ were characterized. Results showed that surface roughness was mainly affected by lathe feed. Surface machining caused grain refinement at the top layer. A severely deformed layer with different thicknesses formed on all samples. In addition to high defect density caused by surface deformation, phase transformation, residual stress, and strain also affected the oxidation behaviour of SA182 Grade 304 SS in the test solution. Machining parameters used for # 4 (feed, 0.15 mm/r; back engagement, 2 mm; cutting speed, 114.86 m/min) and # 6 (feed,0.20 mm/r; back engagement, 1 mm; cutting speed, 73.01 m/min) samples were found to be proper for lathe machining of SA182 Grade 304 SS.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.171-176
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• 1997

In this paper, We have analyzed dynamic characteristics of cutting force. Test materials are used martensitic heat resisting steel, STS420J2. The obtained results are as follows: 1. Cutting force is smaller make small feed when feed speed make a change. 2. Principal cutting force is smaller make small cutting speed when feed speed make a change.