• Title/Summary/Keyword: Tool life

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Characteristics of tool wear in cutting of glass fiber reinforced plastics (유리섬유 강화 플라스틱 절삭시의 공구마멸 특성)

  • 강명순;이원평
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.1055-1062
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    • 1988
  • The characteristics of tool wear and the machinability in cutting of GFRP have been studied. The wear behavior of carbide insert tools(P20, M10, K10) and Cermet in TiC grade was studied by turning of changing the cutting condition. Machinability could be estimated as the following empirical formula, CT$^{n}$ =W The main results obtained are as follows: (1) Dependence of rate of tool wear on cutting speed; with increases of cutting speed, the rate of tool wear initially increases gradually(1st range), then it increases proportionally to cutting speed(2nd range), and finally the rate is constant(3rd range). (2) When the contact length has a main, effect on tool wear, the cutting speed does nit affect the tool wear. On the contrary, the cutting speed has a main effect on tool wear, the contact length does not affect the tool wear. (3) The order of machinability is K10, M10, P20 and Cermet in TiC grade.

Cutting Force Characteristics and Tool Deflection When Machining Rectangular Shapes with a Ball End Mill (볼엔드밀 공구에 의한 사각형상 가공시 공구 휨에 따른 절삭력 특성)

  • Kim, In Soo;Kim, Sang Hyun;Lee, Dong Sup;Wang, Duck Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.6
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    • pp.26-32
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    • 2019
  • Ball end mills used for high-speed and high-precision machining require longer machining time than flat end mills or face cutters, since the tool diameter is limited and the rigidity is reduced by the characteristics of the tool's cutting edge: at the top end of the tool, the cutting speed approaches zero and hardly removes any material. Because there is little material removal at the top end of the ball end mill, the outer cutting edge performs the majority of the work; this irregular cutting force deforms the tool and shortens its life. In this study, we attached an eddy-current sensor to a tool to measure the deformation from the cutting force and we used a tool dynamometer to measure the cutting force. We found that the change in cutting force is dependent on the change in feed rate during square-shaped processing and, as the feed rate is accelerated, the cutting force also increases. Higher cutting forces increase tool deformation.

The Relationship of Symptoms of Side Effects, Fatigue and Quality of Life in Stomach Cancer Patients receiving Chemotherapy (수술후 화학요법받는 위암환자의 부작용 증상, 피로 및 삶의 질과의 관계)

  • Yang, Young-Hee
    • Korean Journal of Adult Nursing
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    • v.14 no.2
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    • pp.205-212
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    • 2002
  • Purpose: The purpose of this study was to investigate the level of nausea, vomiting, anorexia, fatigue and quality of life as well as to determine the relationship between those variables and identify the influencing factors on fatigue and quality of life in stomach cancer patients receiving adjuvant chemotherapy. Method: Subjects were 94 stomach cancer patients undergoing postoperational chemotherapy in a general hospital in Seoul. Nausea and vomiting were measured with Rhodes et al(1984) and anorexia with one 5-point item. Fatigue was measured using Lee's tool(1999) except open questions. The tool for quality of life was modified based on the Quality of Life Index by Padilla et al(1983). Result: Subjects reported low level of fatigue(mean=3.86, range=0-10) compared with the results of previous researches and moderate quality of life(mean=2.64, range=1-4). Fatigue was positively correlated with nausea, vomiting and anorexia(r=.21 ~ .55, p<.05). Quality of life was negatively correlated with nausea, vomiting, anorexia(r= -.24 ~ -.45, p<.05) and fatigue (r=-.61, p<.01). Multiple regression analysis revealed that activity level, vomiting before admission, anorexia during chemotherapy and age explained 52.8% of the variance in fatigue. Fatigue, anorexia before admission, age and sex explained 50.5% of the variance in quality of life. Fatigue and quality of life were not influenced by the stage of disease, nor weight change. Conclusion: These results may contribute to a better understanding of how much the side effects of anticancer drugs can affect fatigue and quality of life in cancer patients undergoing chemotherapy. Also it is the remarkable fact that symptoms remaining after discharge such as vomiting or anorexia continued until re-admission, contributing to patients fatigue and lowered their quality of life.

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The Effect of Yoga and Health Calisthenics Program in the Middle Aged Women on Physiological Index and Life Satisfaction (요가와 건강체조 프로그램이 중년여성의 생리적 지수와 생활만족도에 미치는 효과)

  • Min, Soon;Jang, Sook-Hee;Kim, Hye-Sook;Ha, Yun-Ju;Chung, Kyoung-A;Jung, Sun-Ju
    • Journal of Korean Biological Nursing Science
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    • v.12 no.2
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    • pp.97-105
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    • 2010
  • Purpose: The purpose of this study was to examine the effect of yoga and health calisthenics program in the middle aged women on physiological index and life satisfaction. Methods: This research was an one group pretest-posttest design. A pre and post measurement tool of the program was applied to measure body weight, obesity, rate of body fat, vital capacity, inhalation rate of oxygen, sit-up, grasping power, total physical response, body anteversion, body mass index (BMI), total physical strength, physical strength, health age, life satisfaction. Data collected from this tool was analyzed by SPSS in paired t-test. Results: The results were summarized as follows: yoga program group, the body weight, obesity, BMI, %body fat of the decreased. The results of pulmonary yoga group, vital capacity and inhalation rate of oxygen, total physical strength examination results showed a significant difference. Conclusion: In this study, the yoga program was effective in positive on body composition and physical strength, life satisfaction in middle aged women.

A Preliminary Study on the Korean Version of Quality of Life-Alzheimer's Disease (QOL-AD) Scale in Community-dwelling Elderly with Dementia (지역사회 거주 치매환자에서 한국판 삶의 질 -알쯔하이머병 척도 개발을 위한 예비연구)

  • Shin, Hee-Young
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.3
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    • pp.243-248
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    • 2006
  • Objectives: The Quality of Life-Alzheimer's Disease (QOL-AD) scale is a reliable and valid tool for assessing the quality of life (QOL) in the elderly with dementia. This study aimed to develop the Korean version of Quality of Life-Alzheimer's Disease (KQOL-AD) scale for the demented elderly living in the community. Methods: KQOL-AD was administered to two groups: 24 demented elderly and 72 cognitively impaired elderly with no dementia (CIND) who were living in the community Each elderly person and their caregiver rated the elderly QOL. The Korean version of mini-mental state examination (MMSE-K), the clinical dementia rating (CDR), the activities of daily living (ADL), and the neuropsychiatric inventory (NPI) were also assessed. The reliability and validity of the KQOL-AD were examined. Results: In the dementia group, the internal consistency (Cronbach's $\alpha$), the split half and the test-retest reliabilities of the KQOL-AD were excellent. Scores on the KQOL-AD were significantly correlated with the scores of the NPI, but they were not significantly correlated with scores of the MMSE-K, CDR and ADL. In addition, the CIND group showed similar results to the dementia group. Conclusions: KQOL-AD might be a reliable and valid instrument for assessing QOL in the elderly with dementia It could be used as an important outcome measure for research on the demented elderly.

Reliability and Validity of an Instrument for Adolescents Meaning in Life Scale(AMIL) (청소년 대상 생의 의미 측정도구의 신뢰도 및 타당도 검증)

  • Kang, Kyung-Ah;Kim, Shin-Jeong;Song, Mi-Kyung;Sim, Song-Yong
    • Journal of Korean Academy of Nursing
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    • v.37 no.5
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    • pp.625-634
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    • 2007
  • Purpose: The purpose of this study was to test the reliability and validity of an MIL instrument for adolescents. Method: The research design was a three-phase, methodological study. 1) The original 46 items of the Meaning in Life (MIL) Scale were reviewed and corrected partially by 20 adolescents. 2) The content was validated by an expert panel (n=15) and adolescents (n=5). 3) The instrument was validated by survey (n=468). Finally, 33 items were chosen for the adolescents meaning in life(AMIL) scale. Results: Cronbach's alpha coefficient of the 33 items was .92, confirming the high internal consistency of the instrument. 2) Eight factors were extracted through factor analysis: 'experience of love', 'making efforts for goal', 'awareness of essential being', 'awareness of self limitation', 'feeling of satisfaction', 'relation experience', 'positive thinking', and 'hope'. These factors explained 58.26% of the total variance. Conclusion: AMIL Scale was identified as a tool with a high degree of reliability and validity. The tool can therefore be effectively utilized to assess the degree of meaning of life in caring areas for adolescents. Studies on AMIL of different adolescent subjects are needed for further verification.

Development of a Nutritional Assessment Tool for Home Care Centers (가정간호대상자 영양상태 평가도구 개발)

  • Kim Kyoung-Rye
    • Journal of Korean Academy of Nursing
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    • v.34 no.6
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    • pp.1014-1024
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    • 2004
  • Purpose: The purpose of this study was to develop a tool for nutritional assessment, so that home care nurses can make early assessment of patients' nutritional status. Method: The study was done in two parts first a tool was developed to assess nutrition, and second the content validity and clinical validity of the categories and indices were verified. Result: The results of this study are summarized in two ways. First, the nutritional assessment tool was classified into 3 areas, physical measurement, nutritional survey and clinical survey, and into 11 categories with 22 indices. Second, when 5 of the 11 categories were positive, nutritional status was considered to be poor. Conclusion: By developing a clinically useful nutritional assessment tool for patients receiving home care, which was developed in this study, the quality of life for these patients will improve and contribution to the development of a more effective clinical home nursing practice will occur.

Performance Characteristics of CVD Diamond Cutting Tools

  • Oles, E.J.;Cackowski, V.J.
    • The Korean Journal of Ceramics
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    • v.2 no.4
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    • pp.203-211
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    • 1996
  • CVD diamond tools are becoming more widely used in industry as an economic alternative to polycrystalline diamond (PCD) for machining non-ferrous and non-metallic materials. Although CVD diamond-sheet tools have been on the market for several years, diamond-coated carbide inserts have become available only recently, with the successful resolution of long-standing adhesion problems. Diamond coating morphology on the rake surface of the tool affects chip formation favorably, whereas a microscopically rough, faceted morphology on the flank surface of the tool produces a rough workpiece finish. Workpiece finish can be improved by using a coated tool with a larger nose radius. The tool life provided by diamond-coated tools(~30 $\mu\textrm{m}$ thick) can meet or exceed that of PCD tools, depending on the characteristics of the workpiece material. When using diamond-coated carbide tools in milling, a sharp-edged PCD tool should be used in the wiper position of the cutter to minimize workpiece roughness and burr formation.

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A Study on Characteristics of Surface Roughness by Cutting Condition Variation in Face Milling (정면밀링가공시 절삭조건 변화에 표면거칠기 특성에 관한 연구)

  • 김성일
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.10a
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    • pp.248-253
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    • 1997
  • The ideal surface roughness is obtained by tool geometry and feed rate in face milling. however actual surface roughness is affected by various factors such as cutting conditions. vibration and used tool. To improve the quality and productivity of the machining parts, lots of research on the evaluation of tool life and control of surface roughness has been required. Therefore, the width of flank wear, cutting force, and surface roughness are monitored to analyse the characteristics of surface roughness. This experimental investigation is mainly focused on the characteristics of surface roughness in multi-insert milling using TiN coated tool.

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Performance Evaluation of Ti-Al-N coated Endmill by Arc ton Plating (아크이온플레이팅에 의한 Ti-Al-N코팅 엔드밀의 성능평가)

  • 이상용;강명창;김정석;김광호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.251-254
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    • 2002
  • The technique of high speed machining is widely studied in machining field. In this study, TiAIN single-layered and TiAIN/TiN double-layered coatings were applied to end-mill by an arc ion plating technique. Their performances were comparatively studied about cutting force, tool wear, tool life and surface roughness of workpiece under high speed cutting conditions. The TiAIN single-layer coated tool showed higher wear-resistance due to its higher hardness, while the TiAIN/TiN double-layer coated tool showed better performance for high metal removal, i.e., high fled per tooth condition due to its higher toughness. The surface roughness of the workpiece was not influenced by the wear amount of coated tools.

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