• Title/Summary/Keyword: Special tools

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Cataloging Policy and Descriptive Cataloging Rules for Non-book Materials in Korea (비도서자료의 편목정책과 기술규칙)

  • Cho Myeung-Hee
    • Journal of the Korean Society for Library and Information Science
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    • v.30 no.4
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    • pp.61-83
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    • 1996
  • In ordo. to establish cataloging procedures for non-book materials(NBM), library has In make policy decisions which will apply to all materials. This study explores problem areas in bibliographic control and descriptive cataloging for NBM and issues to be decided in cataloging policy for NBM are presented. Recently proposed KORMARC Rules for Descriptive Cataloging, NBM is looked into and compared with AACR2R and some problems to be considered for revising are suggested. Principle and tools needed for subject analysis of NBM are discussed and special issues of subject analysis for NBM are presented.

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The Mechanism and Detection of Tool Fracture using Sensor Fusion in Cutting Force and AE Signals for Small Diameter Ball-end Milling (미세 볼엔드밀가공시 절삭력과 음향방출신호에 의한 공구 파손 검출 및 메커니즘)

  • Wang, Duck-Hyun;Kim, Won-Il;Lim, Jeong-Suk
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.3
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    • pp.24-31
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    • 2004
  • A successful on-line monitoring system for conventional machining operations has the potential to reduce cost, guarantee consistency of product quality, improve productivity and provide a safer environment for the operator. In fine-shape machining, typical signs of tool problems such as vibration, noise, chip flow characteristics and visual signs are almost unnoticeable without the use of special equipment. These characteristics increase the importance of automatic monitoring in fine-shape machining, however, sensing and interpretation of signals ar more complex. In addition, the shafts of the mini-tools break before the typical extensive cutting edge of the tool gets damaged. In this study, the existence of a relationship between the characteristics of the cutting force and tool usage was investigated, and tool breakage detection algorithm by LabVIEW was developed and the following results are obtained. It was possible to use a relative error compare which mainly used in established experiment and investigated tool breakage detection algorithm in time domain which can detect AE and cutting force signals more effective and accurate.

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5-Axis CNC Machining of Roller Gear Cam (롤러 기어 캠의 5-축 CNC 가공)

  • Cho, Hyun-Deog;Yoon, Moon-Chul;Kim, Kyung-Jin
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.6
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    • pp.739-745
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    • 2010
  • The roller gear cam can control the rotational follower periodically by attaching several roller on the circumstance of follower shaft and it is widely used in non-backlash and precise actuating mechanism such as index table or ATC of machine tools. For machining the roller gear cam, 5 axis CNC machine tool is used and the geometric principle of CAM mechanism must be adopted to generate the NC-code and to develop the special CAD/CAM software because there is not commercial CAM system to machine the roller gear cam. The maker of the specially developed software in domestic user is generally from Japan or Taiwan. However these softwares do not reflect the post processing technique for finish machining in the module. Also, there is some limitation for further new application of itself and it needs higher costs for further application. In this study, the CAD/CAM software to overcome these problem was developed. And its reliability was verified by applying it in 5-axis CNC machining. Finally, the experimental result conducted in the 5-axis machining show good consistency in the movement of follower along the flute and in its Size.

Computational Design of Bifurcation: A Case Study of Darundi Khola Hydropower Project

  • Koirala, Ravi;Chitrakar, Sailesh;Neopane, Hari Prasad;Chhetri, Balendra;Thapa, Bhola
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.1
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    • pp.1-8
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    • 2017
  • Bifurcation refers to wye division of penstock to divide the flow symmetrically or unsymmetrically into two units of turbine for maintaining economical, technical and geological substrates. Particularly, water shows irrelevant behavior when there is a sudden change in flow direction, which results into the transition of the static and dynamic behavior of the flow. Hence, special care and design considerations are required both hydraulically and structurally. The transition induced losses and extra stresses are major features to be examined. The research on design and analysis of bifurcation is one of the oldest topics related to R&D of hydro-mechanical components for hydropower plants. As far as the earlier approaches are concerned, the hydraulic designs were performed based on graphical data sheet, head loss considerations and the mechanical analysis through simplified beam approach. In this paper, the multi prospect approach for design of Bifurcation, incorporating the modern day's tools and technology is identified. The hydraulic design of bifurcation is a major function of dynamic characteristics of the flow, which is performed with CFD analysis for minimum losses and better hydraulic performances. Additionally, for the mechanical design, a simplified conventional design method as pre-estimation and Finite Element Method for a relevant result projections were used.

Development of Cold Forging Process of Hollow-type Wheel Nut Wrench for Commercial Vehicles (상용차용 중공형 휠 너트 렌치의 냉간단조 공정 개발)

  • Kim, H.S.;Youn, J.W.
    • Transactions of Materials Processing
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    • v.21 no.8
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    • pp.493-498
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    • 2012
  • A wheel nut wrench is one of the hand tools used to loosen and tighten lug nuts on automobile wheels and it has generally a solid-type geometry for commercial vehicles. However, the solid-type wheel nut wrenches manufactured by hot forging processes exhibit several drawbacks such as heavy weight and rough surface finish. Thus, many efforts have been devoted to change the part geometry and improve the manufacturing process. For this purpose, the weight of the final product can be reduced drastically using a hollow tube as the initial stock, which can be manufactured by the more economical manufacturing process of cold forging. In this study, the cold forging of a hollow-type wheel nut wrench for commercial vehicles was designed based on the results of fundamental experiments and CAE analyses using the commercial finite element code DEFORM-3D. In addition, cold forging experiments were conducted on a special-purpose forming machine for hollow wheel nut wrenches in order to validate the designed process sequence. As results, it was found that the final products with a weight reduction of 39% and better surface appearance can be manufactured without any defect with the newly designed cold forging process.

Study on the Machinability of Pinus densiflora at Chunyang District for Wood Patterns - Effect of Chip-Tool Contact Stress Distribution in Workpiece During of Wood Machining - (목형용(木型用) 춘양목(春陽木)의 절삭가공(切削加工) 특성(特性)에 관(關)한 연구(硏究)(제1보(第1報)) - 절삭중(切削中) 공구면(工具面)의 응력분포에 미치는 접촉(接觸)칩의 영향(影響) -)

  • Kim, Jeong-Du
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.4
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    • pp.54-60
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    • 1988
  • Machinabilities means inherent properties of pinus densiflora at Chunyang district to be CNC machined easily or not, and processing abilities of the tool and machine together. This explanation signifies that machinabilities have two phases of signification, depended on considering and stress either materials or tools preferentially. This paper discuss machinabilities, the following items are usually employed as the indices of stress distribution at the cutting tool rake face. The stress distributions on the chip - tool contact surface at the early stage of the chip forming and under the stage of fringe pattern in wood cutting were analyzed the photoelastic method. The tool used in the present experiment was the special cutting tool H.S.S. one made in laboratory. And isochromatic fringe pattern and isolinic line of work piece by chip-behavior during the cutting operation were photographed with the feed camera continuously. The effects on the stress, distribution on the rake face of the epoxy tool and the strain distribution in the work piece of wood plate by chip behavior are cleared in pre cent experiment.

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Study on the Machinability of Pinus densiflora at Chunyang District for Wood Patterns - Cutting Force, Surface Roughness and Suface Phenomenon by Face Milling - (목형용(木型用) 춘양목(春陽木)의 절삭가공(切削加工) 특성(特性)에 관(關)한 연구(硏究)(제2보(第2報)) - 정면(正面)밀링 절삭(切削)에 의한 절삭저항(切削抵抗), 표면조도(表面粗度) 및 가공표면상태(加工表面狀態) -)

  • Kim, Jeong-Du
    • Journal of the Korean Wood Science and Technology
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    • v.16 no.4
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    • pp.61-69
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    • 1988
  • Recently the automization of wood manufacturing and the development of CNC machine tools becomes the center of interest. Cutting mechanism, tool wear and the roughness of machined surface have been studied. In the studies about wood for special uses, concrete data of cutting is desired. While Pinus densiflora is characterized that heartwood develops as age increases, Chunyang District has the characteristic of strength, red color, relatively regular chap and high heartwood - percentage. But there is no data about cutting this wood, Chunyang District. In this study face milling by sintered carbide tool was excuted to Chunyang District. Cutting force, Surface roughness and states were investigated with regard to cutting speed. Example results were as follows; 1) Mean cutting resistance against lateral component force and longitudinal component force decreased rapidly up to cutting speed of 155 m/min, and remains constant above this speed. 2) The surface roughness of cutting surface lowered as cutting speed increased, regardless of fiber formation. Radial rougness of fiber is larger than lineal surface roughness. 3) Increase in Cutting speed made machining mark restrained. Down-milling showed larger marks than up-milling.

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Nano Scale Compositional Analysis by Atom Probe Tomography: I. Fundamental Principles and Instruments (Atom Probe Tomography를 이용한 나노 스케일의 조성분석: I. 이론과 설비)

  • Jung, Woo-Young;Bang, Chan-Woo;Gu, Gil-Ho;Park, Chan-Gyung
    • Applied Microscopy
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    • v.41 no.2
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    • pp.81-88
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    • 2011
  • Even though importance of nano-scale structure and compositional analysis have been getting increased, existing analysis tools have been reached to their limitations. Recent development of Atom Probe Tomography (APT), providing 3-dimensional elemental distribution and compositional information with sub-nm scale special resolution and tens of ppm detection limit, is one of key technique which can overcome these limitations. However, due to the fact that APT is not well known yet in the domestic research area, it has been rarely utilized so far. Therefore, in this article, the theoretical background of APT was briefly introduced with sample preparation to help understanding APT analysis.

Developed Location Based Service System for Management of Underground Facilities' DB (지하시설물 DB의 유지관리를 위한 LBS 시스템 개발)

  • 이현직;황창섭;박기석;유지호
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.325-333
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    • 2004
  • Since 1995, One of the NGIS(National Geographic Information System) projects, the underground utilities project has been finished in 2003. The 19 cities in korea for this project will use underground utilities management system using underground utilities database focusing on water and sewage system. However, special expert, technical and experience problem in computer environment has not been had in working department for water and sewage management and maintenance for each local government. The management and maintenance of underground utilities database by manual method is getting lowered a data quality of underground utilities database because of the data omitting, error in writing and securing of the lasted database. Therefore, in this study, Application test for field workers using a mobile tool and environment analysis of wireless communication in Korea and application test of GPS receiver for mobile tools had been processed and made a mobile working environment. The efficient management and maintenance method for underground utilities database has been developed an off- line method for modification and update of database about general work which has a high working frequency because of the limitation of wireless communication environment Also, the emergency working has been applied for on-line method.

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A Study on Cosmetic Purchasing Behavior according to Clothing Shopping Orientation of 20's females (20대 여성의 의복쇼핑성향에 따른 화장품구매행동)

  • 송혜인;이옥희;강영의
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.11
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    • pp.1593-1604
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    • 2002
  • The purpose of the study were to find how the trend had an effect on a buying motivation, a selecting standard, a frequency of use, a purchase place of cosmetics, makeup and the distinctive quality of social strata of regarding a clothing shopping orientation. The subjects of investigation were the women in twenties who live in Seoul and Chonnam province. This study had been done from May to July 2001, and 660 questionnaires were used for analysis. The measuring tools used were the items of matters of preceding studies and developed ones by researchers on which questionnaires were prepared. Factor and cluster analysis and Duncan's multiple range test, ANOVA, x$^2$-test, frequency, and percentage as analysis methods were used through SPSS. The results of the study were as follows. The clothing shopping orientation divided five shopping orientations such as ostentatious style, enjoyable style, economical style, and prudent style, and an attachment style for special brands and shops. On the basis of this result, the groups 20's females were classified into low groups by the cluster analysis; economical shopping group, indifferent shopping group, conspicuous shopping group, and recreational shopping group. In the case of cosmetics purchasing motives, evaluation criteria of cosmetics, stores selection criteria were found according to shopping orientation subdivision, and there was the significant difference between the groups in frequency of use, a purchase place of cosmetics.