• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1807-1810
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• 2003

The formed tool is used to machine the unique shape of rubber seal for geometrical shaping and reduction of cutting time. The bearing rubber seal produced by hot press forming has complex geometry for the complex geometrical shape to prevent leakage of lubricant oil and influx of the dust effectively. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining mold of the seal. In this paper, It is performed for selection of the formed tool to investigate cutting edge wear, cutting force, and surface quality. Also, an efficient high precision machining is proposed on the experiment data.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.73-81
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• 1996

This paper presents a general procedure for the selection of the machining parameters for a given machine which provides the maximum material removal rate using a Genetic Algorithms(GAs). Some constraints were given in order to achieve desired surface integrity and cutting tool life conditions as wel as to protect machine tool. Such a constrained problem can be transformaed to unconstrained problem by associating a penalty with all constraint violations and the penalties are included in the function evaluation. Genetic Algorithms can be used for finding global optimum cutting conditions with respect to the above cost function transformed by pennalty function method. From the demonstration of the numerical results, it was found that the near optimal conditions could be obtained regardless of complex solution space such as cutting environment.

• Journal of Korean Institute of Industrial Engineers
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• v.15 no.2
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• pp.45-55
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• 1989

This paper deals with development of a computer-aided process selection and sequencing technique and its software for metal cutting processes of rotational parts. The process selection procedure consists of selection for proper machining operations and machine tools suitable for the selected operations. Machining operations are selected based on machining surface features and machine tools are selected by employing a conversion table which converts machining operations into machine tools. The process sequence is determined by the proper manipulation of the precedence relation matrix. A computer program for the proposed technique is developed by using Turbo-Pascal on IBM PC/AT compatible system. The proposed technique works well to real problems.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.3
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• pp.213-220
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• 1993

This experiments were carries out to estimate the optimum final cutting date in autumn and the selection of highly adaptable varieties in mountainous pastures of Taekwalyong area. The evaluations were based on the data of varietal differences of dry weight of lant(DW) and yield components of the 1st cutting as affected by various final cutting dates of last autumn. Nine varieties of fall fescue Barvetia, Fuego, Demeter, Safe Barcel Forager, Johnstone, Enforcer and Stef, were used and 4 final cutting date of autumn were $C_1$, cut on 30 Sept. $C_2$, on 14 Oct. $C_3$, on 28 Oct. and $C_4$ on 11 Nov.. respectively. The results obtained were as follows; 1. Between the dry weight of plant(DM) and yield components of 1st cutting were different by various final cutting dates of autumn. The dry weight of plant(DW) was significantly positive correlated with heading characteristics of the 1st cutting in earlier cuttings$(C_1-C_3)$ of autumn, but there was not significant correlated with heading characteristics of the 1st cutting in the latest cutting$(C_4)$ of autumn. 2. The variety of Forager with heavier weight of heading tiller(HTW) and dry weight of tiller(WT) showed the highest dry weight plant(DW) of the 1st cutting in earlier cuttings$(C_1-C_3)$ of autumn, whereas the variety of Barcel with high number of tillers per plant(NT) showed a high dry weight of plant(DW) of the 1st cutting in the latest cutting$(C_4)$ of autumn. 3. Optimum final cutting date and critical period of mountainous pastures in Taekwalyong area were estimated in late September$(C_1)$ and middle October$(C_2)$, sespectirety. 4. The dry weight of plant(DW) of the 1st cutting was significantly negative correlated with final cutting dates in growth period of autumn.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.63-69
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• 2013

Many researchers are trying to reduce the use of lubrication fluids in metal cutting to obtain safety, environmental and economical benefits. The aim of this study is to determine the optimization lubrication conditions in minimum quantity lubrication(MQL) turning of workpieces with taper angle. This study has been considered about various conditions of MQL. The objective functions are cutting force and surface roughness. Design factors are nozzle diameter, nozzle angle, MQL supply pressure, distance between tool and nozzle and length of supply line. The cutting force and surface roughness were statistically analyzed by the use of the Box-Behnken method. As a results, optimum lubrication conditions were suggested and verification experiment has been performed. The results of this study are expected to help the selection of lubrication conditions in MQL turning.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1649-1654
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• 2009

Induction motors widely use in industry because structure is simple and hard and cost is generally cheap and they are easy to control. In recently, because of saving steel, ventilation and benefit of frame fixing, rectangular core type induction motors use in industry more and more. This paper presents current characteristic according to stator core cutting degree in three-phase induction motor (IM) with rectangular stator core. According to stator cutting degree, magnetic saturation and paths of flux are changed. Because of these situations, phase currents are unbalance and are produced harmonic components and they cause decrease of efficiency. We analyze each $10^{\circ}$ from $0^{\circ}$ to $30^{\circ}$ using 2-D finite element analysis (FEA). Optimal stator cutting core degree selection supplies stable currents and efficiency improvement. In this paper, loss separation test was executed by IEEE Std. 112-98 Method B and we compare with the result of loss separation by Simulation using FEM and by Experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.573-574
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• 2012

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.4
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• pp.67-74
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• 2008

This study was carried out to select proper species for early stage replantation in cutting-slope area of the Baekdu Range roadside. In the cutting-slope area and upper forest area of the cutting-slope area, sample plots of 104 were selected and their vegetations and environmental factors were investigated. We found total 151 species in the 104 plots. The species of high frequency of Baekdu Range roadside were found in the order of Lespedeza bicolor, Festuca arundinacea, Eragrostis curvula, Pinus densiflora, Salix hulteni, Lespedeza cuneata, Erigeron annuus, Rubus crataegifolius, Spodiopogon sibiricus, etc. The dominancy of Festuca arundinacea, Eragrostis curvula, Lespedeza bicolor, Pinus densiflora, Salix hulteni, Spodiopogon sibiricus, Miscanthus sinensis, Lespedeza maximowiczii, Acer ginnala were 12.74%, 10.43%, 7.48%, 4.42%, 4.09%, 3.13%, 2.49%, 2.45%, 2.40% in the roadside cutting-slope, respectively. The importance value of Quercus mongolica, Lindera obtusiloba, Rhododendron mucronulatum, Lespedeza maximowiczii, Rhododendron schlippenbachii, Lespedeza bicolor, Quercus serrata, Rhus trichocarpa were 17.32%, 13.82%, 11.60%, 11.31%, 8.76%, 8.04%, 7.65%, 7.10% in shrub layer of the upper forest area, respectively. The species of Carex lanceolata, Spodiopogon sibiricus, Carex siderosticta, Miscanthus sinensis, Artemisia sp., Potentilla fragarioides var. major, Astilbe chinensis var. davidii, Chrysanthemum zawadskii var. latilobum, Aster scaber, Lysimachia clethroides, Patrinia villosa, Lindera obtusiloba, Rhododendron mucronulatum, Rhododendron schlippenbachii, Rhus trichocarpa, Stephanandra incisa, Zanthoxylum schinifolium, Lespedeza sp., Lespedeza cuneata, Amorpha fruticosa, Ligustrum obtusifolium, and Weigela subsessilis, may be more helpful in stabilizing of the cutting-slope area and making harmony with the surrounding forest area.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.221-243
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• 2023

The use of roadheaders has been increasing to mitigate the problems of noise and vibration during tunneling operations in urban area. Since lack of experience of roadheader for hard rock, the selection of appropriate machines and the evaluation of cutting rates have been challenging. Currently, empirical models developed overseas are commonly used to evaluate cutting rates, but their effectiveness has not been verified for domestic rocks. In this paper, a comprehensive literature review was conducted to assess the rock cutting force, cutterhead capacity, and cutting rate to select the appropriate machine and evaluate its performance. The cutterhead capacity was reviewed based on the literature results for the site. Furthermore, a new empirical model and simplified method for predicting cutting rates were proposed through data analysis in relation to operation time and rock strength, and compared with those of the conventional model from the manufacturer. The results show good agreement for high strength range upper 80 MPa of uniaxial compressive strength.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.09a
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• pp.59-79
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• 2006

The successful execution of shield tunnelling depends on the cutting ability of cutter. So the selection of shape, size and material of cutter according to geology condition is important work. Since shield tunnelling method was first invented in 1881, the cutting tool for rock has been developed owing to various experiments and researches, the study for soil, however, is insufficient. This paper introduces the shield tunnelling that will be carried out on weathered rock section (920m) of Seoul Subway Line 7 Extension C703. The shape and the material of cutter are discussed required for execution without replacement of cutter tool as well as for advance of excavation efficiency. In addition the estimation method of cutter abrasion in case of excavation on weathered soil is proposed and verified. Specially, the coefficient of abrasion for different soil and cutter is proposed by means of investigation into construction example of foreign country.