• International Journal of Highway Engineering
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• v.14 no.5
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• pp.67-74
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• 2012

PURPOSES: In this study the influence factors related to abrasion resistance of interlocking concrete block have been evaluated, and comparisons between various domestic and foreign abrasion test methods was also accomplished. METHODS: The modified rotational cutting method suggested in ASTM C 944 was applied. Surface materials with different types of fine aggregate such as crushed sand, sea sand, and mixture of crushed and sea sand were tested to compare the aggregate effect for abrasion resistance. RESULTS: The different surface mixtures with various W/C ratios, mortar and fly ash ratios have been investigated for functional and economical considerations. CONCLUSIONS: This study had obtained reliable results by changing diamond blade of rotating cutter. Therefore, in order to improve the abrasion resistance of interlocking concrete block for road, a new mix design was proposed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.1
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• pp.67-72
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• 1995

To select the highest yield soiling type forage, the yield performance of selected sorghum-sudangrass hybrids imported in 1992 have been evaluated at Chonnam region. The soiling type hybrids used in this experiment were TE-haygrazer, FP-5 Sudan, Sweet sioux V, and X -78050. Three different cuttings were done on July 6, August 6 and September 16 in 1992. This trial was arranged as a randomized complete block design with three replications under taken over a period 5 months from May to September in 1992. The results of this experiment were summarized as follows: The hybrids tested were not significantly different by plant height, leaf blade length, leaf blade width and stem diameter. In the first cutting, dry matter yield of FP-5 Sudan was the highest. In the second and third cutting, dry matter yield of Sweet sioux V was the highest among hybrids. The contents of crude protein, hemicellulose, relative feeding value(RFV), and amino acid were the highest by the first cutting, but NDF and ADF were shown the lowest.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.89-92
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• 1997

The aim of the research was to investigate the herbage yield and some characteristics of three triticale cultivars (Beaguelita, Eronga and Juanillo) harvested at the boot and milky-waxy ripeness stages in 1993-94 and 1994-95. A randomized complete block design with three replications was used. Although there were no significant differences between the years and the cultivars, significant differences were found between the harvest stages and for most of the parameters studied superiority was observed for the late cutting (at milky-waxy ripeness). The highest crude protein (11.9%) and crude ash (9.4%) contents were obtained h m the boot stage, whereas the highest yields for green matter, dry matter, crude protein and crude ash were obtained h m the milky-waxy ripeness stage (34.94; 11.65; O.% and 0.92t/ha, respectively). Also, the dry matter content was higher at the late cutting (33.4%).

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.69-77
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• 2001

This paper describes a method of calculating the feedrate for the constant cutting speed at a CL-point in 5-axis machining. Unlike 3-axis machining, 5-axis machining has the flexibility of the tool motions due to two rotation axes. But the feedrate at joint space differs from the feedrate at a tool tip(the CL-point) of the 3D Euclidean space for the tool motions. The proposed algorithm adjusts the feedrate based on 5-axis NC data, the kinematics of a machine, and the tool length. The following calculations is processed for each NC block to generate the new feedrate; 1) calculating the moving distance at the CL-point, 2) calculating the moving time by the given feedrate, 3) calculating the feedrate of each axis, 4) getting the new feedrate. The proposed algorithm was applied to a 5-axis machine which had a tilting spindle and a rotary table. Totally, the result of the algorithm reduced the machining time and smoothed the cutting-load by the constant cutting speed at the CL-point.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.434-437
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• 2004

This paper presents the development of a new climbing mechanism for inter-block welding in Shipbuilding. The climbing mechanism is that it is career type of robot that can pass over block interval for welding of interblock in shipbuilding. The point part of mechanism is that move ballscrew. The Ballscrew`s capacity account and dynamic analysis of leg part are achieved through this paper. Force and torque analysis were achieved by simulation. This can have strong point in side of cost-cutting and welding amount of work than existent method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1301-1307
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• 2001

Video retrieval system must offer representation frame list to do to do play from point that user wants. Representation frame list can get though cut detection point exactly. This paper dismembers frame to fixed block to cut detection point, and compare same block histogram cost of next time frame. If result that compare does not exceed thresold, detect next frame to cutting.

• Journal of Welding and Joining
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• v.21 no.5
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• pp.518-524
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• 2003

The block assembly of ship consists of a series of heat processes such as cutting, bending, welding, residual stress relaxation and fairing. With the fast development of computers, the thermal elasto-plastic analysis method has become a versatile tool for practical applications in the ship production. If numerical analysis is proved to be an advantageous tool to predict the residual deformation due to various heat processes, the optimum methods which can remove the welding distortion can be presented at each assembly stage, which will result in great progress in improving the accuracy of block assembly. In order to minimize the weld-induced angular distortion in thick weldments, this paper proposes the optimum groove design for various plate thickness as the distortion control method. The validity of this method has been substantiated by a number of numerical simulations and experiments.

• Journal of Ocean Engineering and Technology
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• v.22 no.6
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• pp.100-105
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• 2008

The block assembly of ship consists of a series of heat processes such as cutting, bending, welding residual stress relaxation and fairing With the fast development of computers, the thermal elasto-plastic analysis method has become a versatile tool for practical applications in the ship production. If numerical analysis is proved to be an advantageous tool to predict the residual deformation due to various heat processes, the optimum methods which can remove the welding distortion can be presented at each assembly stage, which will result in great progress in improving the accuracy of block assembly. In order to minimize the weld-induced angular distortion in thick weldments, this paper proposes the optimum groove design for various plate thickness as the distortion control method. The validity of this method has been substantiated by a number of numerical simulations and experiments.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.6
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• pp.225-229
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• 2011

Most of the silicon cutting methods using the multi-wire with the slurry injection have been used for wafers of the crystalline solar cell. But the productivity of slurry injection cutting type falls due to low cutting speeds. Also, the direct contact with the metal wire and silicon block increases the concentration of metallic impurities in the wafer's surface. In addition, the abrasive silicon carbide (SiC) generates pollutants. And production costs are rising because it does not re-use the worn wire. On the other hand, the productivity of the cutting method using the diamond coated wire is about 2 times faster than the slurry injection cutting type. Also, the continuous cutting using the used wire of low wear is possible. And this is a big advantage for reduced production costs. Therefore, the cutting method of the diamond coated wire is more efficient than the slurry injection cutting technique. In this study, each cutting type is analyzed using the surface characteristics of the solar wafer and will describe the effects of the manufacturing process of the solar cell. Finally, we will suggest improvement methods of the solar cell process for using the diamond cutting type wafer.

• Geomechanics and Engineering
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• v.8 no.4
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• pp.495-510
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• 2015

The applications of water jet cutting (WJC) in coal mine have progressed slowly. In this paper, we analyzed the possibility and reasonableness of WJC application to pressure relief in hard coal seam, simulated the distributive characteristics of stress and energy fields suffered by hard coal roadway wallrock and the internal relationships of the fields to the instability due to WJC (including horizontal radial slot and vertical annular slot) on roadway wallrock. The results showed that: (1) WJC can unload hard coal seam effectively by inducing stress release and energy dissipation in coal mass near its slots; its annular slots also can block or weaken stress and energy transfer in coal mass; (2) the two slots may cause "the beam structure" and "the small pillar skeleton", and "the layered energy reservoir structure", respectively, which lead to the increase in stress concentration and energy accumulation in coal element mass near the slots; (3) the reasonable design and optimization of slots' positions and their combination not only can significantly reduce the scope of stress concentration and energy accumulation, but also destroy coal mass structure on a larger scale to force stress to transfer deeper coal mass.