• Journal of the Korean Chemical Society
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• v.8 no.3
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• pp.98-102
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• 1964

As a practical method to produce the carbonaceous binder, the destructive distillation of coal tar has been studied. The optimum condition on binder in various temp. and cutting time were examined and the compositions of pitch were also examined in connection with ${\alpha},\;{\beta}\;and\;{\gamma}$ by solvent extraction. Coke powder was mixed with binder as treated pitch in the proportions of 77% of coke to 23% of pitch, to give a plastic mix which could then be pressed into molding. The properties of baked body after molding was tested. It was found that cutting of the coal tar at 350${\circ}C$, for 30 min., at 300${\circ}C$. for 1 hr., and at 250${\circ}C$. for 8 hrs. were good condition. Particularly, we found that the cutting of the coal tar obtained by destructive distillation at high temp. and in minimum period of time had shown the best condition for utilization of carbonaceous pitch as binder. The above mentioned cutting condition results in good quality of pitch which is available to be used as binder in carbon industry.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.1
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• pp.1-6
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• 1994

This experiment was carried out to study the effect of cutting frequencies(2, 3: one time grazed after 2 cuts, 3, 4, 6 cuts per year) and nitrogen fertilization(0 and 120 kg per ha and year) on botanical composition of permanent grassland at the "Federal Research Institute for Agriculture in Alpine Regions(Gumpenstein)," Austria The results are summarized as follows: 1. With only fertilizing phosphorus(P) and potassium(K),mean annual dry matter yields were 6.9 - 8.4 ton per ha and highest when only one time grazed after 2 cuts, but fell progressively with increase in cutting frequency and additonal fertilization of nitrogen. The average nitrogen efficiences expensed as dry matter yieldsfig) per feltilized nitrogenfig per ha) were 10.3 kg. 2. When N fertilizer was applied, the proportion of tall and medium grasses in the mixed swards increased by 30 - 50% compared with only fertilizing PK. Whereas swards with fertilizing only PK generally stimulated composition of the legumes at the expense of the grasses(30 - 50%). 3. Although the proportion of tall and medium grasses(Trisetum flavescens and Dachlis glomerara) and tall herbs(hntodon hispidus, Taraxacum oflcinale and Aegopodium podagraria) increased by infrequent cutting, frequently cutting plots helped increase the proportion of short grasses(Poa pratensis and Poa trivialis), especially where plots both had been applied with nitrogen fertilizer. 4. Nitrogen fertilization resulted in higher existence of herbs and weeds such as Taramcum oficinale. Aegopodium podagraria, Galium mllugo, Anthriscus silvestris and Lamium album. 5. Due to unusually high or low cutting frequencies such as 4 cuts or 2 cuts per year increased botanical compostion of Heracleum sphondylium.hondylium.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.35-42
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• 2001

In order to obtain basic information for pure line breeding of hemp which is effective on the pure line preservation and propagation, three varieties were investigative from 1995 to 1996 at Mokpo Experiment Station, Honam Agriculture Experiment Station, and cutting parts, cutting times, cutting length and storage duration after cutting of plant were observed. Higher rooting ratio were observed in cutting of shoot and later branch, in July 5, optimum harvesting time and 5 days after harvesting time, in shorter storage duration,0 and 2 days. Also there were the highest rooting ratio increased by from 12% to 16% in shorter cutting of 10cm than 15cm long cutting in shoot, lateral branch and stem cuttings. Hemp cv. Korea showed higher rooting ratio than the other varieties, Japan and Turkey. Therefore, it was concluded that hemp, a dioecious plant, could be effectively propagated for the pure lines by cutting method, especially in cv. Korea.

• IE interfaces
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• v.15 no.3
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• pp.308-315
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• 2002

This study presents the web based cutting parameter selection system using Group Technology (GT). The GT is basically applied to classify and code the work material and cutting process which are main factors to affect cutting parameter selection. The proposed system has been designed to electronically select proper cutting conditions based on the stored GT database. The existing approaches used in most small and medium sized companies are basically to use manufacturing engineer's experience or to find the recommended values from the manufacturing engineers handbook. These processes are often time consuming and inconsistent, especially when a new engineer is involved. Consequently, the proposed system could automatically and consistently generate the proper cutting conditions (feed, depth of cut, and cutting speed) as soon as relatively simple data input is given thanks to the classified GT database.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.63-69
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• 2003

This study proposes the construction of attractor simulator for cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, cutting force and surface roughness are measured by tool dynamometer. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics. Constructed attractor in this study can be used for cutting characteristics evaluation of non-ferrous metals

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.424-431
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• 2001

This paper is concerned with the unconstrained two-dimensional cutting problem of cutting small rectangles (products), each of which has its own profit and size, from a large rectangle (material) to maximize the profit-sum of products. Since this problem is used as a sub-problem to generate a cutting pattern in the algorithms for the two-dimensional cutting stock problem, most of researches for the two-dimensional cutting stock problem have been concentrated on solving this sub-problem more efficiently. This paper improves Hifi and Zissimopoulos's recursive algorithm, which is known as the most efficient exact algorithm, by applying newly proposed upper bound and searching strategy. The experimental results show that the proposed algorithm has been improved significantly in the computational amount of time as compared with the Hifi and Zissimopulos's algorithm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.898-901
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• 2000

It is known that Si3N4 ceramic insert has less hardness than Al2O3 ceramic insert. But Si3N4 ceramic insert has not only high toughness and strength but also low thermal expansion coefficient, which makes it has longer tool life under thermal stress condition. In this study, commercial Si3N4 ceramic insert and home-made SiC-Si3N4 ceramic insert which has different sintering time and chemical composition is tested under various cutting conditions. The experimental result is compared in terms of tool life and cutting force. Generally, As the cutting speed and the feed rate increased, the cutting force and the flank wear increased too. The performance of SiC-Si3N4 ceramic insert shows the possibility to be a new ceramic tool.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.188-191
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• 2001

Generally, main factors of tool damage are cutting speed, feed rate and depth of cut. The increase of those factors can cause tool breakage or worsen product quality such as machining accuracy deterioration. Those three factors are concerned with cutting force. Cutting force reaches at its maximum value when cutter blade cuts away the object directly, and it is the time when tool damages are at high probability. In this study, we detect the maximum cutting force affecting tool damage and control the maximum cutting force based on the measured peak force.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.1
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• pp.9-16
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• 1996

This is an experimental investigation of the temperature generated in a cutting tool during the machining of stainless steel. The temperature results from the wear of the cutting tool are considered in order to investigate the relation between cause and effect of these factors. This possibility has been tested using a thermocouple technique to record temperature vs. time curves for a variety of cutting conditions. This is done by employing a thermocouple inserted on the tool tip near the major cutting edge. Temperature distributions are calculated using finite element method and compared to the contour maps measured by an optical system. It suggests that the temperature gradients and the tool performance will be dependent on certain facotrs in tool geometry when cutting this material.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.104-107
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• 1996

This paper focuses on a automation selection of optimal cutting conditions and cycle time for multi-spindle metal cutting machines based on machining parameters and tool change schemes which are the two most common terms used in the metal cutting. In this research we used two step generative approach, step 1 is mathematical modeling for the selection fo optimal cutting conditions and the other is GMDH-Type modeling to estimate the system performance evaluation. We developed computer programs for these models and the fitting manufacturing examples are applied to this model and it was shown that the proposed approach has a good potential and offers a valuable tools to analyse the metal cutting system.