• Title/Summary/Keyword: Tool Change

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A Study on the Development and Surface Roughness of Roller Cam SCM415 by 5-Axis Machining (5축 가공에 의한 SCM415 롤러 캠 개발과 표면조도 연구)

  • Kim, Jin Su;Lee, Dong Seop;Kang, Seong Ki
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.4
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    • pp.397-402
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    • 2013
  • In this study, we carried out the each lines of section, using GC (green silicon carbide) whetstone, the SCM415 material which separated by after and before heat treatments process, in 3+2 axis machining centers for integrated grinding after cutting end mill works, the spindle speed 8000 rpm and feed rate 150 mm/min. For the analysis of the centerline average roughness (Ra), we measured by 10 steps stages. Using Finite element analysis, we found the result of the load analysis effect of the assembly parts, when applied the 11 kg's load on both side of the ATC (Automatic tool change) arm. The result is as follows. For the centerline average roughness (Ra) in the non-heat treatment work pieces, are appeared the most favorable in the tenth section are $0.510{\mu}m$, that were shown in the near the straight line section which is the smallest deformation of curve. In addition, the bad surface roughness appears on the path is to long by changing angle, the more inclined depth of cut, because the chip discharging is not smoothly.

Study on the possibility of Digital Infrared Thermographic Imaging as a prognosis evaluation tool for patients with facial palsy (안면신경마비 환자의 예후 평가 도구로서의 적외선 체열 촬영(DITI - Digital Infrared Thermographic Imaging) 가능성에 대한 연구)

  • Bae, Hyo-Bin;Ko, Woo-Shin;Yoon, Hwa-Jung
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.3
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    • pp.62-75
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    • 2017
  • Objectives : The aim of this study is to evaluate possibility of DITI as prognosis evaluation tool of facial palsy. Methods : We investigate prognosis of facial palsy through EMR(Electronic Medical Record) of inpatient from December 2016 to June 2017. We evaluated the sex, age distribution, length of hospital stay, paralysis site, number of treatment after discharge, change of H-B Grade at entrance and exit, temperature difference of both sides of DITI, and Nerve Conduction Study(NCS) with reference to EMR recorded symptom change. Results : 1. Significant correlations were not found between DITI and House-Brackmann Grade change, NCS(%), the date of admission. 2. There was a negative correlation between NCS(%) and hospitalization period in patients with facial palsy. The higher the NCS, the faster the recovery rate of facial palsy. 3. In patients with facial palsy, the temperature difference between the two sides after the DITI image shows that the affected side tends to be lower than the normal side. Conclusions : In this study, only DITI temperature difference between both sides of face is not significant in determining the prognosis of facial palsy. Further research is needed to conduct DITI at the same time and to improve accuracy through a sufficient assessment of the degree of facial palsy.

Development and Application of Questionnaire for Self-Understanding and Change Capacity Related to Science Education: Focus on the Recognition of Pre-Service Elementary Teachers (과학교육 관련 자기이해와 변화역량 조사 도구 개발 및 적용 -초등예비교사의 인식을 중심으로-)

  • Jo, Kwanghee;Joung, Yong Jae;Choi, Jaehyeok;Kim, Heekyong
    • Journal of The Korean Association For Science Education
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    • v.38 no.6
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    • pp.901-917
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    • 2018
  • The purpose of this study is to develop the questionnaire on pre-service elementary teachers' recognition of self-understanding and change capacity for science education and to investigate their recognitions with it. At the beginning of the study, we made a tool to investigate the self-understanding and change capacity of pre-service elementary teachers through literature review and discussions. The former half of the questionnaire was related to self-understanding with factors such as 'self-concept clarity,' 'career identity' and 'self-efficacy:' 'self-understanding as a pre-service elementary teacher' (12 items) and 'self-understanding as a pre-service elementary science teacher' (12 items). Its latter half was about the change capacity with factors such as 'change sensitivity,' 'goal consciousness,' 'collaboration,' 'reflection,' and 'mastery.' It consisted of three parts: 'general change capacity,' 'change capacity as a pre-service elementary teacher' and 'change capacity as a pre-service elementary science teacher' with 17 items, respectively. With this tool, we surveyed 153 pre-service elementary teachers. The results are as follows: First, pre-service elementary teachers have a positive recognition about self-understanding and change capacity, but the recognition of self-understanding and change capacity as pre-service elementary science teachers were relatively less positive. Second, factors of self-understanding and change capacity as pre-service elementary science teachers have a significant correlation with each other. Especially, there was a high correlation between 'self-efficacy' of self-understanding and 'goal consciousness' and 'mastery' of change capacity. Based on these results, some implications for self-understanding and change capacity related to science education were discussed.

Comparative Analysis of Regional Integrated Assessment Models of Climate and the Economy (사회후생함수를 중심으로 한 기후경제통합-지역평가모형 비교분석)

  • Hwang, In Chang
    • Environmental and Resource Economics Review
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    • v.25 no.1
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    • pp.27-60
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    • 2016
  • An integrated assessment model of climate and the economy (IAM) has been a standard tool for the economic analysis of climate change and policy recommendations. Since policy measures to address climate change take places at a national level, a regional integrated assessment model of climate and the economy (RIAM) is gaining more importance. A RIAM is a useful tool for the assessment of regional (or national) impacts of climate change. This paper investigates the main features of the currently available RIAMs. The focus is social welfare functions and the regional aspects of climate change. The comparative analysis shows that there is a huge gap between the economics of climate change and its applications to RIAMs. As an application, this paper examines the effect of social welfare functions on optimal solutions of the RICE (Regional Integrated model of Climate and the Economy) model. It is found that optimal climate policy such as carbon tax or emissions control rate is very sensitive to the assumptions on social welfare functions of RIAMs. It is better for each country to have their own RIAM as a basic tool for national climate policy-making and for international bargaining in greenhouse-gas mitigation. This is because a country's own preferences such as efficiency, equity, and sustainable development as well as national circumstances can be reflected in RIAM. The Republic of Korea has not developed its own RIAM yet. The comparative analysis and the numerical model in this paper can be a stepping stone for the development of such a national model.

A Study on the Detection of the Abnormal Tool State in Drilling of Hot-rolled High Strength Steel (열연강판의 드릴링시 공구의 이상상태 검출에 관한 연구)

  • 신형곤;김민호;김태영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.888-891
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    • 2000
  • Drilling is one of the most important operations in machining industry and usually the most efficient and economical method of cutting a hole in metal. From automobile parts to aircraft components, almost every manufactured product requires that holes are to be drilled for the purpose of assembly, creation of fluid passages, and so on. It is therefore desirable to monitor drill wear and hole quality changes during the hole drilling process. One important aspect in controlling the drilling process is drill wear status monitoring. With the monitoring, we may decide on optimal timing for tool change. The necessity of the detection of tool wear, fracture and the abnormal tool state has been emphasized in the machining process. Accordingly, this paper deals with the cutting characteristics of the hot-rolled high strength steels using common HSS drill. The performance variables include drill wear data obtained from drilling experiments conducted on the workpiece. The results are obtained from monitoring of the cutting force and Acoustic Emission (AE) signals, and from the detection of the abnormal tool state with the computer vision system.

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Shear Process and Frictional Characteristics in Down-end Milling

  • Lee, Young-Moon;Jang, Seung-Il
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.4
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    • pp.19-24
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    • 2003
  • In end milling process, which is characterized by the use of a rotating tool, the undeformed chip thickness varies periodically with phase change of the tool. Although many efforts have concentrated on the study of end milling process, the analysis of shear and chip-tool friction behaviors has not been reported. Recently, a model has been proposed to simulate the shear and friction characteristics of an up-end milling process in terms of the equivalent oblique cutting. In the current study, the varying undeformed chip thickness and the cutting forces in a down-end milling process are replaced with the equivalent ones of oblique cutting. Then it is possible to simulate the shear and the chip-tool friction characteristics of a down-end milling process. The proposed model has been verified through two sets of cutting tests i.e., down-end milling and the equivalent oblique cutting tests. The experimental results show that the proposed model is suitable to analyze the shear and chip-tool frictional characteristics of down-end milling process. The specific cutting energy decreases with increase in equivalent undeformed chip thickness in a down-end milling process.

Guidelines for the VESTAP-based Climate Change Vulnerability Assessment (VESTAP 기반 기후변화 취약성 평가 지침)

  • Park, Doo-Sun;Park, Boyoung;Jung, Eunhwa
    • Journal of Climate Change Research
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    • v.8 no.4
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    • pp.339-346
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    • 2017
  • The Korea Adaptation Center for Climate Change (KACCC) located in Korea Environment Institute has serviced a climate change vulnerability assessment support tool (VESTAP) since 2014 in order to help local governments to establish their own adaptation plans. Owing to its easy usage, the VESTAP has been utilized by not only local governments but also academia for examination of climate change vulnerability in various fields. However, the KACCC has not suggested a standard usage how to compose indices for climate exposure, sensitivity, and adaptation capacity which are main components of vulnerability although the KACCC manages operation and application of the VESTAP. Many users had no choice but to compose indices based on their own interpretation on the components of vulnerability. This technical note suggests the standard usage of VESTAP by reevaluating some vulnerability assessments previously developed. This may help users to correctly compose indices for climate change vulnerability assessment, and may minimize possibility of inter-user inconsistency in definition of vulnerability assessments.

Effects of climate change and reduction method on water quality in Cheongmicheon watershed (기후 변화에 따른 청미천 유역의 수질 변화 및 저감 대책에 관한 연구)

  • Byun, Jisun;Son, Minwoo
    • Journal of Korea Water Resources Association
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    • v.51 no.7
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    • pp.585-597
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    • 2018
  • This study aims to investigate the variation of water quality and discharge under the condition of climate change and Best Management Practices (BMPs), which is one of the reduction methods for non-point source pollution. Soil and Water Assessment Tool (SWAT) model is applied to case in Cheongmicheon watershed. The coefficients required for SWAT model were calibrated using SWAT Calibration and Uncertainty Program. Climate change is considered by using Representative Concentration Pathway (RCP) scenarios, RCP 4.5 and RCP 8.5. It is known from simulation results that the non-point source pollutant increases under the climate change scenario assuming worse condition. It is also found in this study that an appropriate application of BMPs is able to reduce the quantity and temporal variation of non-point source pollutant effectively.

Validity and Reliability of the Korean Version of the Climate, Health, and Nursing Tool (한국어판 기후 건강관련 간호사 인지행동 측정도구의 타당도와 신뢰도)

  • Jeong, Da Woon;Kim, Gwang Suk;Park, Min Kyung
    • Journal of Korean Academy of Nursing
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    • v.52 no.2
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    • pp.173-186
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    • 2022
  • Purpose: Climate change has various negative effects on human health, which has resulted in increased burden on the health care system. Nurses contribute significantly to assessing climate-related health risks and creating a healthy environment. This study aimed to evaluate the reliability and validity of the Korean version of the Climate, Health, and Nursing Tool (K-CHANT) to measure nurses' awareness, motivation, concern, and behaviors at work and at home regarding climate change and health. Methods: The 22 items of English CHANT were translated into Korean with forward-backward translation techniques. Internal consistency reliability, test-retest reliability, and construct validity using confirmatory factor analysis were performed using SPSS WIN (25.0) and AMOS (26.0). Survey data were collected from 220 master's, doctoral, and post-doctoral nursing students. Results: The K-CHANT consists of 20 items across 5 domains. Two items of the original CHANT were excluded because of low content validity index and standardized regression weights. The internal consistency reliability of the K-CHANT, assessed by Cronbach's α was .81, with an intraclass correlation coefficient of .66~.90. The five subscales model was validated by confirmatory factor analysis (SRMR < .08, RMSEA < .08, AGFI > .70, CFI > .70). Conclusion: The K-CHANT has satisfactory construct validity and reliability to measure nurses' awareness, motivation, concern, and behaviors at work and at home regarding climate change and health. Future research should examine nurses' perceptions and behaviors related to the health effects of climate change and develop an action plan to improve it.

Requirement Analysis and Optimal Design of an Operational Change Detection Software

  • Lee, Young-Ran;Bang, Ki-In;Shin, Dong-Seok;Jeong, Soo;Kim, Kyung-Ok
    • Korean Journal of Remote Sensing
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    • v.20 no.3
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    • pp.189-196
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    • 2004
  • This paper describes what an operational change detection tool requires and the software which was designed and developed according to the requirements. The top requirement for the application of the software to operational change detection was identified: minimization of false detections, missing detections and operational cost. In order to meet such a requirement, the software was designed with the concept that the ultimate decision and isolation of changes must be performed manually by visual interpretation and all automatic algorithms and/or visualization techniques must be defined as support functions. In addition, the modular structure of the proposed software enables the addition of a new support function with the minimum development cost and minimum change of the operational environment.