• Title/Summary/Keyword: T-T(tool to tool) time

검색결과 375건 처리시간 0.029초

초산모를 위한 산후간호 교육의 효과 (Effects of Education on Primiparas' Postpartial care)

  • 신혜숙;김숭희;권숙희
    • 여성건강간호학회지
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    • 제6권1호
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    • pp.34-45
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    • 2000
  • The study was to find whether the educational program contributed to increase of knowledge and self-efficacy of the postpartal primiparas. This study aimed at improvement of the educational effect for postpartal primiparas. The Subjects were 34 primiparas who were admitted to the obstetric ward in a University hospital from November 15th to December 9th, 1999. The Subjects were those who had no labor pain at the admission time, had no complications during labor and delivery and, gave birth to a healthy baby. They were tested on knowledge and self-efficacy two times, one at the admission time and prior to discharge. After the first test nurses in a maternity ward taught them on postpartal care. Two tools were developed by authors based on literature review. The test tool fr knowledge of postpartal car consisted of 23 items. The test tool for self-efficacy of postpartal care consisted of 16 items. Analysis of demographic data were analyzed with calculation of percentage. Score differences between the first test and the second test were analyzed with paired t-test. The Spss (Win 8.0) program was used for data analysis. The results are as follows. 1. There were not significant influencing general characteristics of primiparous to pre-educational knowledge. There were significant influencing general characteristics of primiparous to post-educational knowledge : occupation(t=13.04, p=0.00), postpartal education(t=5.51, p=0.02). 2. There were not significant influencing general characteristics of primiparous to pre-educational self-efficacy. There were significant influencing general characteristics of primiparous to post-educational self-efficacy : antenatal education(t=5.53, p=0.02) 3. Primiparas' knowledge of postpartal care increased significantly after education(t=13.04, p=0.00). 4. Primiparas' self-efficacy of postpartal care increased significantly after education(t=5.51, p=0.02). 5. Correlation between knowledge and self-efficacy was r=.360(p=0.03). We suggest follow-up studies to find whether primiparas' self-efficacy will last after discharge or not.

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고속 머시닝센터의 진동특성 및 가공성 평가 (Evaluation of Vibration Characteristics and Machinability of High Speed Machining Center)

  • 강익수;강명창;김정석;김기태
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.424-429
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    • 2004
  • The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation for HMC is not sufficiently performed and the efficient cutting conditions can't be selected, a peat loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented by the analysis of acceleration in idling. The Machinability for the TiA1N coated flat end mill and STD11 (H$\sub$R/C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions . The resonance spindle speed is identified through the tool wear and natural frequency test.

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HIGH-SPEED MILLING FOR DIE AND MOLD MAKING

  • Na, T.kagawa
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 Handout for 2000 Inter. Machine Tool Technical Seminar
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    • pp.51-60
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    • 2000
  • High-speed milling machine is being sold mainly in the market of die and mold industries, because it reduces machining time greatly as proportion to the spindle speed of machine tool. From the experimental milling tests, it has been cleared that the ball end mill is quite suitable for high speed milling and also tool wear reduces in higher speed milling condition. And a new milling concept with ultra high speed over 100, 000 rpm is proposed for solving the various problems such as NC cutter path generation and NC feed conformity etc.

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T2 Relaxographic Mapping using 8-echo CPMG MRI Pulse Sequence

  • E-K. Jeong;Lee, S-H.;J-S. Suh;Y-Y wak;S-A. Shin;Y-K. Kwon;Y. Huh
    • 한국자기공명학회논문지
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    • 제1권1호
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    • pp.7-20
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    • 1997
  • The mapping of the spin-spin relaxation time T2 in pixed-by-pixel was suggested as a quantitative diagnostic tool in medicine. Although the CPMG pulse sequence has been known to be the best pulse sequence for T2 measurement in physics NMR, the supplied pulse sequence by the manufacture of MRI system was able to obtain the maximum of 4 CPMG images. Eight or more images with different echo time TEs are required to construct a reliable T2 map, so that two or more acquisitions were required, which easily took more than 10 minutes. 4-echo CPMG imaging pulse sequence was modified to generate the maximum of 8 MR images with evenly spaced echo time TEs. In human MR imaging, since patients tend to move at least several pixels between the different acquisitions, 8-echo CPMG imaging sequence reduces the acquisition time and may remove any misregistration of each pixel's signal for the fitting T2. The resultant T2 maps using the theoretically simulated images and using the MR images of the human brain suggested that 8 echo CPMG sequence with short echo spacing such as 17∼20 msec can give the reliable T2 map.

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척추질환자의 요통사정을 위한 통증행위 관찰법의 신뢰도 및 타당도 검정 (Reliability and Validity of the Behavioral Observation Method for Assessing Low Back Pain in Patients with Spinal Diseases)

  • 윤호순;이은옥
    • 근관절건강학회지
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    • 제1권1호
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    • pp.97-115
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    • 1994
  • The purpose of this study was to examine the reliability and validity of the observed behaviors of subjects who suffered from low back pain with spinal diseases, Thirty two low back pain patients admitted on the neurosurgical unit in an army hospital were compared with 30 normal controls belonged to an army unit, by means of matching the age, hight and weight. Observed pain behaviors were developed by the researcher on the bases of literature and patient observation. This tool consists of 18 behaviors seperated into two major groups : mutually exclusive and concomittent behaviors. The mutually exclusive behaviors included coding cathegories for 6. body motions assumed by the subjects during the observation session. These 6 standardized motions consisted of sitting from standing first, and serially tying down, reclining, sitting again, and then standing, 6 steps walking. Concomittent behaviors consisted of 12 observable patterns that can be observed systematically from the face, grimacing, bracing, rubbing, walking with arms fixed, support with hands on sitting or standing, guarded movement, limping, unbalaced weightbearing, stopped movement from tying position to sitting, sighing and graoning. Subjects were videotrecorded as they performed a 6-standardized sequence of motions, simultanously researcher measured the time spent performing each motion and step length. Patients were asked torate their subjective pain score on the 10 mm graphic rating scale ranging from 'no pain' to 'sever pain'. For scoring of the pain behaviors, two trained nursing officiers independently and simutanously viewwd each videorecording and checked subject 'pain behaviors at the observational item checklist. The result of the study are summarized as follows : 1. Reability of the observational tool was a=.845. 2. Spearman's rho and percentage agreement were p=.97 and 81.7 persent respectively, that indicate adequate interrater reability of this tool. 3. The sensitivity rate of the tool was .875 while specificity rate .866 for differentiating patient from the normal. 4. When difference in the objective pain indices between patient group and control were compared, there was significant difference of all indices, such as pain behavior(t=7.71, p=.0001). spent time performing motion(t=14.2, p=.0001), step length (t=-10.72, p=.0001). 5. There were differences in the objective indices the subjective pain subgroups (low, medium, high). Differences in the mean score of objective pain behavior (F=6.376. p=.005) and spent time for moyion(F=4.631, p=.018). But there were no significant differences in the step length among the subgroups(F=.667, p=.521). 6. Highly correlated pain behavior items wiyh subjective pain score were 'stopped movement from lying position to sitting', 'limping', 'support with hands on sitting or standing', 'bracing', 'guarding' and 'walking with arms fixed'. In summary, although some of rho behavior items such as sighing and groaning in this study could not be observed because of videotaped datd, the reliability and validity of the over all observation method were satifactory. Thus, the results of the present study demonstrate rye potetional utility of the tool in assessing objective pain complementing self-reported pain in low back pain patients.

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Worm 절삭 가공 시 Side Milling Cutter 와 Whirling Tool 의 절삭력에 관한 연구 (A Study on the Cutting Force of Side Milling Cutter and Whirling Tool in Worm Screw Machining)

  • 권태웅;김창현;강동배;이민환;안중환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1879-1882
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    • 2005
  • Due to increase of demands on safety and convenience for automotive vehicle, the use of DC motor, such as power window, seat adjusting, pedal adjusting, sunroof, electric shift motor and so on, is increasing rapidly in the whole world. Worm gear is an important part to transmit torque to another gear in gear mechanism of automotive DC motor. But with current forming process, it has some problems in manufacturing and the quality. Also, the characteristics of automotive parts such as price and mass-production limit the quality improvement. Recently several methods are used in order to reduce a worm screw machining time and to maintain precision. In this paper, we introduce whirling tool machining and side milling cutter machining as effective manufacturing method of worm screw and study on the cutting force of side milling cutter and whirling tool in worm screw machining.

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알루미늄 홀 가공 하중 분석을 통한 펀치 마모수준 예측에 관한 연구 (A study on the prediction of punch wear level through analysis of piercing load of aluminum)

  • 전용준
    • Design & Manufacturing
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    • 제16권4호
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    • pp.46-51
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    • 2022
  • The piercing process of creating holes in sheet metals for mechanical fastening generates high shear force. Real-time monitoring technology could predict tool damage and product defects due to this severe condition, but there are few applications for piercing high-strength aluminum. In this study, we analyzed the load signal to predict the punch's wear level during the process with a piezoelectric sensor installed piercing tool. Experiments were conducted on Al6061 T6 with a thickness of 3.0 mm using piercing punches whose edge angle was controlled by reflecting the wear level. The piercing load increases proportionally with the level of tool wear. For example, the maximum piercing load of the wear-shaped punch with the tip angle controlled at 6 degrees increased by 14% compared to the normal-shaped punch under the typical clearance of 6.7% of the aluminum piercing tool. In addition, the tool wear level increased compression during the down-stroke, which is caused by lateral force due to the decrease in the diameter of pierced holes. Our study showed the predictability of the wear level of punches through the recognition of changes in characteristic elements of the load signal during the piercing process.

웹 기반의 시각적 스트레스 증후군 선별에 관한 연구 (A Study of Web based Screening for Visual Stress Syndrome)

  • 장영건
    • 대한인간공학회지
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    • 제28권4호
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    • pp.91-99
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    • 2009
  • A visual stress may provoke migraine, cephalalgia, intervene a long term reading and learning capability and reduce the productivity of a laborer who uses computer for a good while. In this study, a web based screening tool for visual stress was developed, it applied to 72 visually normal young persons in parallel with traditional questionnaire about symptoms of visual stress. To estimate visual stress, It is proposed to measure difference of visual search time of Han Gul characters as targets between visual stressful pattern and non-visual stressful pattern as global background of characters. As a result of test, 5 subjects were screened whose mean visual search time in the stressful pattern with 6 CPD spatial frequency increase significantly more than in none stressful pattern(t-test, one-tailed, p=$1.0407\times10^{-11}$). 2 of them were diagnosed as mild visual stress syndrome in the clinic. None had visual distortion and 50% of subjects had visual discomfort in results of the questionnaire. Correlation between visual search time increase rate and normalized number of visual discomfort may be slight(C. coefficient=0.1355). This study may contribute as a basic research for screening person with migraine, visual reading disabilities and VDT syndrome. It is required to apply the test to visual reading disabilities, migraine with visual distortion and/or visual discomfort as well as normal person for higher reliability of the screening tool.

전기자동차 충전기의 누전차단기 감도 전류 Trip 방지를 위한 Joule Heating 시뮬레이션 방안연구 (A Study on Joule Heating Simulation Method to Prevent Sensitivity Current Trip of Electric Vehicle Charger)

  • 이병국;어익수
    • 한국산학기술학회논문지
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    • 제22권4호
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    • pp.150-159
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    • 2021
  • 본 논문에서는 충전 시 발생하는 누전차단기 Trip으로 충전 중단에 의한 전기자동차 사용자의 불편함을 방지하기 위한 것이다. 현장 사례연구로 충전기 고장(failure) 유형, 차종별 누설전류 측정실험, 누전차단기 동작 실험 시 여름철 충전기 내부 온도가 60 ℃이상까지 상승하여 누전차단기가 정격 감도 전류의 80%에서 Trip으로 충전 중단됨을 확인하였다. Joule Heating 모델링을 통하여 32A 전류를 초기 시간 t=0 (s)의 기준온도 30℃에서 통전하여 t=3000 (s)경과 후에는 누전차단기 충전부 주위에서 발열이 32.4℃까지 증가함을 시뮬레이션으로 확인하였으며, 통계 검증 tool을 활용하여 온도 및 시간(s) 요인이 발생 열량에 상관관계 0.97로 검증되었다. 본 논문의 연구 실험 결과는 충전기 기구 물 개발 시 충전케이스의 재질, 내부 배선의 배치, 유전 매질에 따른 Joule Heating 시뮬레이션 수행으로 여름철 충전기 내부 온도 상승에 의한 누전차단기 감도 전류 Trip을 방지할 수 있음을 알 수 있었다.

Internet of Things-Based Command Center to Improve Emergency Response in Underground Mines

  • Jha, Ankit;Verburg, Alex;Tukkaraja, Purushotham
    • Safety and Health at Work
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    • 제13권1호
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    • pp.40-50
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    • 2022
  • Background: Underground mines have several hazards that could lead to serious consequences if they come into effect. Acquiring, evaluating, and using the real-time data from the atmospheric monitoring system and miner's positional information is crucial in deciding the best course of action. Methods: A graphical user interface-based software is developed that uses an AutoCAD-based mine map, real-time atmospheric monitoring system, and miners' positional information to guide on the shortest route to mine exit and other locations within the mine, including the refuge chamber. Several algorithms are implemented to enhance the visualization of the program and guide the miners through the shortest routes. The information relayed by the sensors and communicated by other personnel are collected, evaluated, and used by the program in proposing the best course of action. Results: The program was evaluated using two case studies involving rescue relating to elevated carbon monoxide levels and increased temperature simulating fire scenarios. The program proposed the shortest path from the miner's current location to the exit of the mine, nearest refuge chamber, and the phone location. The real-time sensor information relayed by all the sensors was collected in a comma-separated value file. Conclusion: This program presents an important tool that aggregates information relayed by sensors to propose the best rescue strategy. The visualization capability of the program allows the operator to observe all the information on a screen and monitor the rescue in real time. This program permits the incorporation of additional sensors and algorithms to further customize the tool.