• Title/Summary/Keyword: Cross-sectional drawing

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The Effect of Drawing and Heat Treatment on Fatigue Life and Machinability in Free Machining Steel (쾌삭강의 피로수명 및 절삭성에 미치는 인발-열처리의 영향)

  • Suh, C.H.;Kim, D.B.;Oh, S.K.;Jung, Y.C.;Park, M.K.;Kim, Y.S.
    • Transactions of Materials Processing
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    • v.19 no.2
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    • pp.95-100
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    • 2010
  • Drawing and normalizing are efficient means for controlling strength, fatigue and machinability of free machining steel. Normally strength and machinability are conflicting properties which need to be optimized. In this study, the effects of normalizing temperature and reduction of area on strength, fatigue and machinability were investigated. Fine grains were generated at lower normalizing temperature and fatigue life was increased with decreasing grain size. Matrix was work hardened and elongated with increasing reduction of area. Inclusions also were elongated and cross-sectional area of inclusions along drawing axis was decreased. The effects of work hardening and grain size on fatigue life were significant, but only work hardening affected machinability. Shape and distribution of inclusions after drawing had little effect on fatigue life and machinability.

Dieless Wire Drawing by Enforced Necking Method (강제 네킹에 의한 금속 와이어 인발)

  • Huh, You;Kim, Seung-Hoon;Kim, Ihn-Seok;Paik, Young-Nam
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.7 s.196
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    • pp.98-105
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    • 2007
  • In modern industries, materials are required that possess multi-functional properties and at the same time flexibility in their shapes with structural stability. The major technology realizing this requirement consists of thinning metal wires and laying them with stable contact nodes. This research has dealt with a new method to manufacture thin wires by drawing without applying dies, but with introducing enforced necking, which enables to process multi-ends. Based on the new method, the process dynamics was modelled and its steady-state characteristics were analyzed. Results showed that the profiles of the material velocity in the drawing zone increased with a downward convex shape, while the cross-sectional area decreased with the shape of upward convex. The microwave heating turned out to be effective in wire drawing, but dependent on the input feeding direction. The variation in the diameters of the drawn wires was negatively affected by increasing the drawing ratio.

유한요소법을 이용한 전방압출공정의 내부결함에 관한 연구

  • 김태형;김병민;강범수;최재한
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.04a
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    • pp.79-83
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    • 1992
  • According to the variation of hydrostatic pressure on the central axis of deformable material, the V-shaped central bursting defect may be created on extrusion or drawing processes. The process factors whichaffect the generation of defects are die semi-angle, reduction ratio of cross-sectional area, friction factor, material properties and so on. The combination of these factors can determine the prossibility of defect creation and the shape of various round holes which have been created inside already. By the rigid plastic finite element method, this paper describes the observations of change in shape of a round hole with process conditions suchas die semi-angle, reduction ratio of cross-sectional area and friction factorat the unsteady state of axi-symmetrical extrusion process when the round hole is alreadyexisted inside the original billet, and also, the effects of process factors are investigated to prevent the possible defects.

A Study on Central Bursting Defects in Forward Extrusion by the Finite Element Method (유한요소법을 이용한 전방압출공정의 내부결함에 관한 연구)

  • Kim, T.H.;Lee, J.H.;Kwon, H.H.;Kim, B.M.;Kang, B.S.;Choi, J.C.
    • Transactions of Materials Processing
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    • v.1 no.1
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    • pp.66-74
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    • 1992
  • According to the variation of hydrostatic pressure on the central axis of deformable material, the V-shaped central bursting defect may be created in extrusion or drawing processes. The process factors which affect the generation of defects are semi-angle of die, reduction ratio of cross-sectional area, friction factor, material properties and so on. The combination of these factors can determine the possibility of defect creation and the shape of various round holes which have been created inside already. By the rigid plastic finite element method, this paper describes the observations of change in shape of round holes with process conditions such as semi-angle of die, reduction ratio of cross-sectional area and friction factor at the non-steady state of axisymmetrical extrusion process when the round hole is already existed inside the original billet. Also, the effects of process factors are investigated to prevent the possible defects.

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A Study on the Possibility of 2D Design Drawing Implementation by Revit Architecture (Revit Architecture를 이용한 2D 설계도면 구현 가능성에 관한 연구)

  • Cho, Yong-Sang;Lee, Heewon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.5243-5250
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    • 2013
  • BIM(Building Information Modeling) enables 3D model-base management for all information produced by construction project during its life cycle. Also as a national policy, BIM has been institutionalized as design criteria. But, on the matter of 2D drawing using BIM software (Revit Architecture), it has been recognized as difficult to realize the same quality drawing drawn by CAD. The purpose of this study is verifying the possibility of printable design drawing implemented by BIM software at the same quality of 2D shop drawing drawn by 2D CAD. Through the analysis of basic design elements of 3D BIM software and 2D CAD software, with the case of partial cross sectional drawing which is most faithful representation of the basic design elements, this study find out that the 3D BIM software can produce the same quality 2D printable drawing utilizing its implicit function.

The Effect of Abdominal Drawing-in Maneuver with Pressure Biofeedback Unit in Various Postures on Abdominal Muscle Contraction

  • Lee, Seunghoon;Lee, Sangyeol
    • Physical Therapy Rehabilitation Science
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    • v.11 no.2
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    • pp.136-144
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    • 2022
  • Objective: This study was to identify the effect of pressure biofeedback applied in various postures that allow the application of abdominal drawing-in. Design: A cross sectional study. Methods: The study intended to compare changes in the thickness of abdominal muscles between different postures when abdominal drawing-in was performed using a pressure biofeedback unit in five postures and to compare differences in terms of measures such as the transverse abdominis's preferential activation ratio(PAR). Data measured from 30 healthy individuals were used for data analysis. A paired t-test and repeated measures analysis of variance was performed to compare the thickness of each abdominal muscle. Results: The transverse abdominis's and internal oblique's thickness showed statistically significant differences in all postures when abdominal drawing-in (p<0.05). In the comparison between the postures, statistically significant differences were observed between the positions of hook-lying and wall support standing and between supine and wall support standing and between hook-lying and sitting (p<0.05). In terms of the transverse abdominis's PAR in each posture, statistically significant differences were observed between hook-lying and quadruped, hook-lying and sitting, hook-lying and wall support standing, quadruped and supine, sitting and supine, as well as wall support standing and supine (p<0.05). Conclusions: When abdominal drawing-in using pressure biofeedback unit is performed for stabilization exercises, selecting and applying specific postures according to targeted muscles and the subject's functional ability will help provide a more efficient and accurate intervention.

Automated design of optimum longitudinal reinforcement for flexural and axial loading

  • Tomas, Antonio;Alarcon, Antonio
    • Computers and Concrete
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    • v.10 no.2
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    • pp.149-171
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    • 2012
  • The problem of a concrete cross section under flexural and axial loading is indeterminate due to the existence of more unknowns than equations. Among the infinite solutions, it is possible to find the optimum, which is that of minimum reinforcement that satisfies certain design constraints (section ductility, minimum reinforcement area, etc.). This article proposes the automation of the optimum reinforcement calculation under any combination of flexural and axial loading. The procedure has been implemented in a program code that is attached in the Appendix. Conventional-strength or high-strength concrete may be chosen, minimum reinforcement area may be considered (it being possible to choose between the standards ACI 318 or Eurocode 2), and the neutral axis depth may be constrained in order to guarantee a certain sectional ductility. Some numerical examples are presented, drawing comparisons between the results obtained by ACI 318, EC 2 and the conventional method.

The analysis of Utilization of LiDAR data in road design (도로설계를 위한 LiDAR 데이터의 활용성 분석)

  • Lee, Hyun-Jik;Park, Eun-Gwan;Park, Won-Il
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.363-366
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    • 2007
  • Road Design is being reached to the working design to produce drawings, calculate construction quantity and cost, through the basic design that contained feasibility study and all impact assessment. In general, to plan the route we use topographic map. The vertical positional accuracy is 30cm and horizontal positional accuracy is 35cm in 1:1,000 scale topographic map. In LiDAR, vertical positional accuracy is 15cm and horizontal positional accuracy is 30cm. So if we use LiDAR on road design, more accurate earth-volumn will be calculated when we plan the route. In this paper we try to find the method to use the LiDAR data on road design by drawing the profile and cross sectional view and comparing the earth-volumn to the road that working design is in process adopting the topographic map and LiDAR data.

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The role of positive affect in virtual collaboration: a transactive memory system perspective

  • Chae, Seong Wook
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.5
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    • pp.99-109
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    • 2016
  • Creative performance has been regarded as the key to the success of an organization in recent years, and is considered essential for the survival of an organization. Organizations must find and develop creative solutions to deal with a variety of business issues. How can organizations become more creative? To develop creativity, organizations must make it easier to connect the knowledge and perspectives of its various members, who may be scattered around the world, by developing a virtual team. Drawing from the transactive memory systems (TMS), which include expertise location, credibility, and coordination, this study investigates how the positive affect of team members influences the development of creative performance during virtual collaboration where face-to-face team activities are limited. The proposed structured model was empirically tested with cross-sectional data from 322 individuals. Results indicated that the positive affect of team members was found to moderate the relationship between TMS and creativity. Through this study, we expect to provide an understanding of the mechanisms involved in developing creativity among team members in a virtual work environment.

Effect of Collective Efficacy on Self-Disclosure in Social Network Services (소셜네트워크서비스에서 집합적 효능감이 이용자들의 자기노출에 미치는 영향)

  • Chae, Seong Wook
    • Knowledge Management Research
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    • v.19 no.1
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    • pp.19-39
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    • 2018
  • With the development of information technology, social network services (SNS) such as Facebook and Twitter became popular and many users disclose their personal and sensitive information like private story, photographs and location information through posting and sharing. Despite the privacy concerns in SNSs, individuals continue to disclose their identity online. This phenomenon is called 'privacy paradox'. The purpose of this study is to examine the role of collective efficacy on self-disclosure in SNS context and to explain privacy paradox phenomenon. Drawing upon the communication privacy management theory, research model was developed and empirically tested with cross-sectional data from 306 individuals. Results revealed that collective efficacy has a direct positive effect on self-disclosure while privacy risk is negatively related to self-disclosure. However, privacy concern is not directly related to self-disclosure. The relationship between privacy concern and self-disclosure was moderated by collective efficacy.