• Title/Summary/Keyword: Die life

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Development of tool-life prediction program to determine the optimal machining conditions in mold machining (금형 가공 시 최적 가공조건을 결정하기 위한 공구수명 예측 프로그램 개발)

  • Soon-Ok Park;Min-Hak Kim;Sun-Kyung Lee;Sung-Taek Jung
    • Design & Manufacturing
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    • v.17 no.1
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    • pp.7-12
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    • 2023
  • Recently, with the emergence of the 4th industrial revolution, the demand for smart factories and factory automation is increasing. In this study, a tool life prediction program was developed to select optimal machining conditions using CNC milling equipment, which is widely used in flexible production and automation. The equipment used in the experiment was Hwacheon Machine Tool's 5-axis machining equipment, and the tool used was a 17F2R tool. For the machining path, the down-milling cutting method was selected and long-term machining was performed. The analysis standard for side wear on the tool was set at 0.1 to 0.2 mm, and tool life data and wear data were obtained in the cutting experiment. The program was created through the data obtained from the experiment, and a prediction rate of over 90% was secured when comparing the experimental data and the predicted data.

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Ethics in the Intensive Care Unit

  • Moon, Jae Young;Kim, Ju-Ock
    • Tuberculosis and Respiratory Diseases
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    • v.78 no.3
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    • pp.175-179
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    • 2015
  • The intensive care unit (ICU) is the most common place to die. Also, ethical conflicts among stakeholders occur frequently in the ICU. Thus, ICU clinicians should be competent in all aspects for ethical decision-making. Major sources of conflicts are behavioral issues, such as verbal abuse or poor communication between physicians and nurses, and end-of-life care issues including a lack of respect for the patient's autonomy. The ethical conflicts are significantly associated with the job strain and burn-out syndrome of healthcare workers, and consequently, may threaten the quality of care. To improve the quality of care, handling ethical conflicts properly is emerging as a vital and more comprehensive area. The ICU physicians themselves need to be more sensitive to behavioral conflicts and enable shared decision making in end-of-life care. At the same time, the institutions and administrators should develop their processes to find and resolve common ethical problems in their ICUs.

Machining Technology of Free From Surface using Controlled of Cutting Speed (절삭속도 일정제어를 통한 자유곡명의 가공기술)

  • 김경균;강명창;이득우;정융호;김정석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.806-809
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    • 2000
  • The factors which can improve tool life in machining are consisted of tool geometries, tool materials, coating methods. cutting environments, cutting conditions and so on. Cutting speed in cutting conditions is one of the important factors which can directly influence on the tool life. This paper deals the machinability which is concerned about the cutting direction and the tilt angle of fret form surface in hot die steel(STD I I). The NC datum were analysrd and the effective tool diameters were calculated according to the change of tilt angle the program which can continue the cutting speed with the change of spindle revolution is developed.

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Evaluation of thermal characteristics by cutting environments in high speed ball end-milling (볼엔드밀을 이용한 고속가공에서 가공환경 변화에 따른 열특성 평가)

  • 이채문
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.04a
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    • pp.34-38
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    • 2000
  • The trend of cutting process today goes toward higher precision and higher efficiency. Many thermal/frictional troubles occur in high-speed machining of die and mold steels.In this paper, the thermal characteristics are evaluated in high sped ball end-milling of hardened steel(HRc42). Experimental work is performed on the effect of cutting environments on tool life and cutting temperature. Cutting environments involve dry, wet(20bar), compressed chilly air at -9$^{\circ}C$, compressed chilly air at -35$^{\circ}C$. The measuring technique of cutting temperature using implanted thermocouple is used. The cutting temperature is about 79$0^{\circ}C$, 35$0^{\circ}C$ and 54$0^{\circ}C$ in dry, wet and compressed chilly air at +9$^{\circ}C$, respectively. The tool life for compressed chilly air at -9$^{\circ}C$ is longer than all other cutting environments in experiment.

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Sand Casting Process Design for the Bush Parts of the Continuous Hot Zinc Plating Roll Applied to Wear-Resistant Alloy Cast Steel (내마모 합금주강 소재를 적용한 연속용융아연도금설비 Roll용 부쉬의 사형 주조공정 설계)

  • Park, Dong-Hwan;Yun, Jae-Jung;Hong, Jin-Tae;Kwon, Hyuk-Hong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.4
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    • pp.104-112
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    • 2017
  • In the sand casting process, the flow of liquid metal affects the quality of casting products and their die life. To determine the optimal bush part design process, this study performed various analyses using commercial finite element analysis S/W. The simulation focused on the molten metal behaviors during the mold filling and solidification stages of sand casting. This study aims to develop methods to reduce the cost and increase the tool life of the continuous hot zinc plating roll.

Characteristics of Tool Life according to the Cutting Direction and Cutting Speed in Machining on Inclined Plane using Ball End Mill (볼 엔드밀의 경사면 가공에서 공구경로와 절삭속도에 따른 공구수명의 특성)

  • 박윤종;김경균;강명창;김정석;이득우
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.05a
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    • pp.240-244
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    • 1999
  • This paper deals with the establishment of the cutting direction on inclined plane by using ball end mill. Ball-end milling is widely used for free form surface die and mold. In these machining, the cutting parts vary because the tool tip is hemisphere shaped. The cutting characteristics, such as cutting force, surface roughness and surface profile are varied according to the variation of cutting directions. The effective tool diameter was calculated on different tilt angles and tool-path. Tool life and cutting characteristics were estimated on variation of cutting directions in the same cutting speed. In this paper, the optimal cutting direction which can be applied 3-D sculpture surface cutting is suggested.

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The Physical Properties of Wheat Flour Extrudates with Added Phenolic Acids (페놀산 첨가 밀가루 압출성형물의 물리적 특성)

  • Koh, Bong-Kyung
    • Journal of the East Asian Society of Dietary Life
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    • v.17 no.3
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    • pp.379-383
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    • 2007
  • The effects of phenolic acids on the physical properties of wheat flour extrudate were investigated. Ferulic acid, fumaric acid, and p-coumaric acid were mixed with hard wheat flour, respectively, and extruded under a twin screw extruder. We found that by adding the phenolic acids, longitudinal expansion at the die increased, textural hardness decreased, and the water absorption capacity of the extrudate decreased. The results showed that the addition of phenolic acids produced a softer textured, more longitudinally puffed and hydrophobic extrudate compared to the control extrudate. Moreover, the addition of phenolic acids did not significantly affect the color of the extrudate: oxidative browning of the phenolic acids was not observed, due to inactivation of the browning enzymes under the hot temperature and reduced oxygen conditions of the extrusion process.

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Selection of Natural Materials for Eco-friendly Control for Blight of Wood-Cultivated Ginseng(Panax ginseng)

  • Lee, Chong-Kyu;Yu, Chan-Yeol
    • Journal of agriculture & life science
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    • v.45 no.2
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    • pp.9-13
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    • 2011
  • This study was carried out to control the disease of wood-cultivated ginseng(panax ginseng) using natural materials. Four fungi spices such as Pythium ultimum, Alternaria alternata, Fusarium oxysporum and Rhizoctonia solani which caused disease of the wood-cultivated ginseng were investigated. The infection of these fungi causes symptom on roots, stems and leaves. The leaves became dry and die. The disease caused by Pythium ultimum can be prevented by using friendly environmental materials like Chamaecyparis obtuse essential oil and Wormstop. Alternaria alternata and Fusarium oxysporum might be prevented by using wormstop extracted from Neem tree(Azadirachta indica). No substance tested effectively prevents the growth of Rhizoctonia solani.

Anomalous Origin of the Coronary Artery from the Pulmonary Artery in Children and Adults: A Pictorial Review of Cardiac Imaging Findings

  • Hyun Woo Goo
    • Korean Journal of Radiology
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    • v.22 no.9
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    • pp.1441-1450
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    • 2021
  • Anomalous origin of the coronary artery from the pulmonary artery is a rare and potentially fatal congenital heart defect. Up to 90% of infants with an anomaly involving the left coronary artery die within the first year of life if left untreated. Patients who survive beyond infancy are at risk of sudden cardiac death. Cardiac CT and MRI are increasingly being used for the accurate diagnosis of this anomaly for prompt surgical restoration of the dual coronary artery system. Moreover, life-long imaging surveillance after surgery is necessary for these patients. In this pictorial review, multimodal cardiac imaging findings of this rare and potentially fatal coronary artery anomaly are comprehensively discussed, and representative images are provided to facilitate the understanding of this anomaly.

A Study of the Meaning of the Elderly's Life in the Super-Aged Rural Community (초고령 농촌사회 노인의 삶의 의미 탐색 - 전북 임실군 금동마을 이야기 -)

  • Kim, Young-Joo
    • Korean Journal of Social Welfare
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    • v.61 no.4
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    • pp.163-190
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    • 2009
  • The purpose of this study is to understand the origin of the super-aged rural community and the meaning of the elderly's life in such a unique society by looking into the elderly's life from the past to the present to the future. For the study in-depth interviews have been done with 16 old people living in Geumdong village, Imshil-gun of Jeonbuk Province, one of the most aged communities of Korea. By analyzing their statements, 4 themes have been found from 11 meanings of statements on the past life, which is characterized by their fight against bonds of extreme poverty and misfortune. On the present life, which is characterized by their bare existence in senility and their endless sacrifice for the children as they are never free from the physical pains accompanying the ageing and the concern about their children, 5 themes have been found from 14 meanings of statements. About the future life, which is characterized by their calm acceptance of the fate of their later life and their village which they think will disappear after they die, 3 themes have been found from 7 meanings of statements.

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