• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.228-233
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• 2009

In order to cut the round bale easily, a roughage cut-feeder for the round bale was developed in this study. This study consists of two parts. One is development of a cutting mechanism and a performance test reported in the previous paper. This is the second part of the study. For the study, recent trend of traditional cutting system was analyzed. Also, cost of the prototype cut-feeder was analyzed and determine the break-even point of farm size was determined by comparing with traditional method using a traditional cutter. A prototype cut-feeder was investigated with the fact that working performance, fiber length and shape of roughage and feeding quality was good. Operating cost of the prototype cut-feeder decreased rapidly with an increase of farm size. Break-even point in terms of farm size was 36 heads for beef and 28 heads for dairy. Also, costs estimated were 118,000 won/head year and 148,000 won/head year, respectively.

• Journal of Ocean Engineering and Technology
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• v.8 no.1
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• pp.131-143
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• 1994

The BTA(boring and trepanning association) deep hole machining has an increasing demands because of its wide applications and its good productivity. The main feature of the BTA tools is that the tool cutting edges are unsymmetrically located on the boring head. This provides a stabilizing cutting force resultant necessary for self guidance of the boring head. The BTA tools are capable of machining for having a large length to diameter ratio in single pass. A study of the accuracy and surface finish of holes produced would reveal quite useful information regarding the process. This study deals with the experimental results obtained during BTA machining on SM55C, SM45C steel under differnt machining conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1007-1010
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• 2002

The accuracy of high speed feeding type laser cutting M/C is the major factor directly concerned with the accuracy of the processed work, and the feed errors of feed system make the machining errors of work directly on processing. In this point, this study focused on the generative elements in feed errors of laser cutting M/C when operating its laser head. In order to improve the accuracy of this machining center, feed errors are measured by a laser interferometer.

• Journal of Welding and Joining
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• v.30 no.1
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• pp.51-58
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• 2012

To assess hydraulic connections between sub-components of the International Thermonuclear Experimental Reactor (ITER) diagnostic port plug, the laser welding and ablation cutting process were investigated in order to be applied the remote handling maintenance. In this study, laser ablation cutting, which vaporizes a small amount of solid material directly into gas by focusing a laser beam of high density energy, is adopted in order to overcome the limitation of the normal laser cutting technology that the head should be placed as close to the work piece as possible to blow out melt metal at a distance. Complete cutting of a work piece is obtained by repetitive multi-passes of the laser beam. The welding and cutting process were tested on the sample work pieces and finally on a prototype of a hydraulic connection module for remote handling. The results showed that this process can be a promising candidate for hydraulic connections by remote handling.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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• pp.81-86
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• 2004

Generally, automotive cylinder head is manufactured by FCD45 material that is hard to cutting materials, and it needs the accurate machining tool fir higher output of engine. This paper is concerned with a study on TiN coated 6 edges reamer for improving machining accuracy of cylinder head guide pin. The reamer shape is changed from 4 edges to 6 edges for the improvement of machining accuracy. Also, TiN coating is applied to the improvement of surface roughness of cylinder head guide pin and tool life of 6 edges reamer. It is noted that 6 edges reamer are effective in controlling the dimensional accuracy and surface roughness as well as increasing tool life.

• Journal of the Semiconductor & Display Technology
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• v.13 no.1
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• pp.13-17
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• 2014

Since the semiconductor manufacturing requires the silicon wafers with extraordinary degree of surface flatness, the surface polishing of wafers from ingot cutting is an important process for deciding surface quality of wafers. The present study introduces the development of wafer polishing equipment and, especially, the wafer polishing head that employs the forced self-driving of installed silicon wafer as well as the wax wafer mounting technique. A series of wafer polishing tests have been carried out to investigate the effects of self-driving function in wafer polishing head. The test results for wafer planarization showed that the LLS counts and SBIR of polished wafer surfaces were generally improved by adopting the self-driven polishing head in wafer polishing stations.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.327-332
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• 2021

Materials used for education include SM20C, Al6061, and acrylic. SM20C materials are used a lot in certification tests and functional competitions as carbon steel, but they are also used in industrial sites. Al6061 is said to be a material that produces a lot of tools because it has lower hardness than carbon steel and is highly flexible. When practical guidance is given to students using acrylic materials, it is a material that causes vibration and tool damage due to excessive cutting. In this process, we examine how impact on the 5-axis equipment 2NC head can affect precision control. The weakest part of a five-axis equipment is the head that controls the AC axis. In the event of precision and cumulative tolerances in this area, the precision of all products is reduced. Thus, a key part of the 2NC head, the spindle housing was carried out using Al7075 T6 (U.S. Alcoasa) material and the entire body using FCD450 (spherical graphite cast iron). In the vibration and cutting process acting on these two materials, the analysis was carried out to determine the value of applying the force as a finite element analysis under extreme conditions. We hope that using these analytical data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

• Journal of Practical Engineering Education
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• v.14 no.1
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• pp.119-125
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• 2022

Materials used for education are materials such as SM20C, Al6061, and acrylic. SM20C materials are carbon steel and are often used in certification tests and functional competitions, but are also widely used in industrial sites. The Al6061 material is said to be a material that has lower hardness and stronger flexibility than carbon steel, so it is a material that generates a lot of compositional selection of tools. If students are taught practical training using acrylic materials, vibration occurs due to excessive cutting in some parts and damage to the tool occurs. In this process, we examine to what extent the impact on the 2NC head, which is a five-axis equipment, can affect precision control. The weakest part of the five-axis equipment can be said to be the weakest part of the head that controls the AC axis. When the accuracy and cumulative tolerance of this part occur, the accuracy of all products decreases. Therefore, the core part of the 2NC head, the spindle housing, was carried out using an Al7075 T6 (Alcoa, USA) material. In the process of vibration and cutting applied to this material, the analysis was conducted to find out the value applied to the finite element analysis under extreme conditions. It is hoped that this analysis data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.142-151
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• 2005

Several advanced countries have been continually developed PHC pile cutting automation machines for improving productivity, safety and quality of the conventional PHC pile cutting work. However, the target work of the previously developed PHC pile cutting automation machines is only crushing the head of PHC pile. Dangerous grinding work is still performed by workers with seven inch hand grinder. In domestic construction industry, the PHC pile cutting work is usually performed by a crusher and three to four skilled workers. Recent analysis results of the PHC pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose the end-effector which can effectively break PHC pile without any longitudinal cracks and to develop an automated pile cutting machine having unified grinder and crusher parts through a wide variety of laboratory and field tests. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1493-1495
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• 1997

Cropping of head and tail ends of rod in wire Rolling Process is required to aviod roll damage, and prevent cobbles. In order to reduce the crop loss, the new crop control system for rotary shear of Wire rolling Process has been developed. Performance shows the developed system cut precisely within setting length. As a result, it is expected to increase the yield ratio of products about 0.2 percent and stabilize the operantional condition.