• Title/Summary/Keyword: moment measure

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Biomechanical analysis of pullout strength of the pedicle screws in relation to change bone mineral density (반복 하중 후 골밀도 감소에 따른 척추경 나사못의 고정력(Pullout Strength)감소 형태 분석)

  • Jung, D.Y.;Lee, S.J.;Kim, D.S.;Shin, J.W.;Kim, W.J.;Suk, S.I.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.155-156
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    • 1998
  • Screw loosening and subsequent pullout can be attributed to the reduction in bone mineral density in the vertebrae manifested by osteoporosis in which the decrease in fixation strength between the cancellous bone and screw threads are accelerated by repeated loads exerted by patients own weight and activities following the surgery. In this study, the change in pullout strength of the pedicle screws was investigated before and after repeated loads were imparted. For this purpose. Diapason pedicle screws $(6.7\times40mm)$ were inserted onto fresh porcine spine specimens (T1-L5) after bone mineral density was measured using a DEXA. With an MTS, an axial load was applied at a loading rate of 0.33mm/sec until failure to measure the maximum pullout strength. Flexion moment of 7.5N-m was then imparted at 0.5Hz for 2000 cycles. It was found that the maximum pullout strength was exponentially related to BMD regardless of load types ($107.71\;\times\;\exp^{(1.43{\times}BMD)}r^2=0.93$, P<0.0001 without repeated load; ($107.71\;\times\;\exp^{(2.19{\times}BMD)}r^2=0.78$, P<0.0001 with repeated load). The results suggest that the reduction in pullout strength for pedicle screws is far more prominent in osteoporotic spine than in normal spine especially as number of repeated load was increased. More importantly, it was demonstrated that the level of bone mineral density and the activity level of the patient should be evaluated in more detail for successful implementation of pedicle screw systems in spinal surgery.

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Prediction of the Blade Flapping Angle for Korean Utility Helicopter by Applying Indirect Method (간접기법을 이용한 한국형 기동헬기 블레이드 플래핑 각도 예측)

  • Kim, Young-Jin;Lee, Sang-Gi;Lee, Seung-Jae;Chang, In-ki;Shim, Dai-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.10
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    • pp.888-895
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    • 2015
  • This paper shows an approximate equation which calculates a flapping angle of blade for verification of KUH safety area. The flapping behavior of blade must be reviewed in an aspect of safety because of a collision possibility with airframe. However, it is difficult to measure an exact flapping angle during flight. A prediction equation of a coning angle is derived from aeromechanics and that of a dynamic flapping angle is derived from analysis results in development phase, respectively. Following, the equations are verified by comparison the flapping angle through an aircraft simulation test to a calculation. Finally, the safety area, which was established in development phase, is verified by calculating a flapping angle during the flight which is required by the terms of safety based on AC29 and FAR29.

The Effect of Perceiver's Attitude on Male Impressions. (관찰자의 의복태도가 의복착용자의 인상에 미치는 영향)

  • 남미우;강혜원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.2
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    • pp.241-256
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    • 1996
  • The purposee of this study was to identify the effect of perceiver's clothing attitude on male impressions created by the clothing cues and contexts. In addition, the effect of perceiver's evaluations of clothing appropriateness on male impressions. The subjects consisted of 256 male undergraduate students and 256 middle aged men. The experimental materials developed for this study were a set of stimuli and response scales. The stimuli were 8 color Photographs of drawings of a male figure in clothing which were minipulated in two levels, each of three clothing cues including type, style and color. The experimental design was full factorial design of 2(contexts$\times$clothing types$\times$clothing style$\times$clothing color). Each of the 16 sub-samples includes 16 subjects from the two perceiver group. Questionnaires used to measure perceivers responses to the stimuli were 7-point semantic differential scales composed of 37 bipolar adjectives representing personal traits. Four aspects of clothing attitude(fashion interest, status symbols consiousness, clothing conformity, practicality & comfort)were used to classify subjects into groups of 20 five-point likers type questionnaires adapted from the previous research. Clothing appropriateness were developed 5 point likest scales for evaluation of a stimulus person in each context. The data was processed by factor analysis, ANOVA, multiple classification analysis, Duncan's multiple range test, cluster analysis, MANOVA and pearson's product moment correlations. The major findings drawn from this study were as follows: 1. Perceiver's clothing attitude influenced impression formed by the social contexts and clothing crises. In three groups classified by their clothing attitude, the status symbol-oriented group was most affected by the social contexts and clothing cues. 2. Perceiver's evaluation of clothing appropriateness was related with impressions by a stimulus person. In summary the effect of contexts and clothing cues on impression formation varied according to perceiver's clothing attitude and clothing approopiateness.

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The Analysis on Job Satisfaction of Personnel Engaged in Contract Food service Management Company (위탁급식전문업체 종사자와 직무만족도 분석)

  • 양일선;박문경;차진아;이해영
    • Korean Journal of Community Nutrition
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    • v.9 no.4
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    • pp.519-527
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    • 2004
  • This study was designed firstly to measure the job satisfaction (JS) levels of personnel engaged in contract food-service management company (CFMC), secondly to compare the job satisfaction levels by personal and company-related characteristics, and thirdly to identify the effects of JS facets on overall job satisfaction. Of 1135 respondents, there were 712 employees in the headquarters and 423 in the branch office. From an analysis on job satisfaction, overall job satisfaction level was 3.22 out of a maximum 5 and the co-worker (3.71) facet of JS was the highest job satisfaction followed by supervision (3.32), work itself (3.26), working condition (3.15), promotion (2.95) and payroll (2.74). In comparison of job satisfaction by personal characteristics, the personnel who were male (p < .01), had associate degrees (p < .01) or long-term careers in foodservice field (p < .05), or were regular employees (p < .01) perceived significantly higher than others for overall JS. In comparison of the job satisfaction by company-related characteristics, overall JS was significant by company scale (p < .01) and by work place (p < .05), but it was not significant by operating group. Finally, on the regression analysis for the effects of JS facets on overall JS, adjusted R2 was 0.534 (p < .001) and all six JS facets, especially payroll, had a positive effect on overall JS significantly (p < .001). Considering that the goal of enterprise on profit-making through customer satisfaction (CS) and the role of personnel on CS at moment of thrust (MOT), the findings confirmed the necessity for continuous internal marketing and human relation management focusing on the lower level of JS facets.

A study on measure of North Korea's nuclear terror threat; Focusing on the guarantee of 'anticipatory self-defense' (북한 핵테러 위협 대비방안 연구; '선제적 자위권' 보장을 중심으로)

  • Kim, Yeon Jun
    • Convergence Security Journal
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    • v.16 no.3_2
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    • pp.13-23
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    • 2016
  • North Korea had recently conducted the fourth nuclear test and ICBM tests, dared nuclear provocation targeting the Korea and the international community. It is determined based on experiments of nuclear and missile in progress in North Korea that the technical level of nuclear force reached the completion stage of standardization, lightweight, and variation. It is expected to become reality that North Korea executes the nuclear provocation targeting the Korea and the international community in the near future. Nuclear bomb is an absolute weapon that the logic of counterattack after allowing the first strike of the other party cannot be applied due to its tremendous destructive power. Therefore, as the opponent to North Korea that it decided to hold the nuclear, the exercise of anticipatory self-defense in order to guarantee a minimum of right to life is not a choice, but the only essential correspondence concept. At the moment that the North Korean nuclear provocation is expected in the near future, it shall be provided with competence to strike the origin region of provocation by forming a national consensus of preemptive strike enforcement. Also, in preparation for the fifth nuclear test of North Korea, which is anticipated, the national competence must be mobilize to be able to ensure the 'Nuclear Option' from the international community.

Improvement of Ammunition Box by Ergonomic Evaluation

  • Lee, Kyung-Sun;Kim, Sung-Hoon;Seo, Song-Won;Jung, Myung-Chul
    • Journal of the Ergonomics Society of Korea
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    • v.34 no.1
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    • pp.1-10
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    • 2015
  • Objective: The purpose of this paper is to evaluate old and newly designed ammunition boxes from an ergonomic point of view. Background: The ammunition boxes made of wood, which are currently used by the military, have some difficulties such as corrosion and damage of ammunition, environmental pollution, and stock management. Also, damages to the wooden ammunition boxes take place frequently, because soldiers carry them manually. Method: Sixteen participants volunteered to randomly perform lifting, carrying, and side-by-side moving tasks with 4 different old and new boxes, respectively for the ammunitions of 5.56mm, 60mm, 81mm, and 105mm in diameter. The old boxes are made of wood and are currently used in the military, while the new boxes are made of plastics. The joint moments of the elbow, shoulder, back, and knee were measured by using a motion analysis system and force platforms. In addition, an electromyographic system was used to measure the forces of hand and wrist muscles. Results: In most tasks, new boxes caused less joint moments at the elbow and shoulder than old boxes, because the new boxes were lighter and smaller than the old boxes. New boxes also derived less hand and wrist muscle forces due to the provision of fixed hard handles rather than string handles. Conclusion: The ergonomically designed new boxes could reduce the physical stresses of soldiers manually handling ammunitions and be helpful for storage and reuse. Application: This study shows an ergonomic application example for product development and evaluation.

Analysis of Hand Hygiene Practices of Health Care Personnels (의료기관 종사자의 손 위생 수행 분석)

  • Oh, Hyang Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6160-6168
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    • 2015
  • Hand hygiene(HH)of the health care personnels(HCPs) was the most effective method to prevent the transmission of healthcare associated infections. This study was conducted to measure and analysis the status of the HH compliance of HCPs. Data were collected by the direct observation methods of the World Health Organizations(WHO) using WHO's HH monitoring tool kits from 25th October to 31th December, 2010. Data were analyzed by descriptive statistics, cross analysis, multiple logistic analysis using the SPSS/PC 21 program. A total of 8,644 opportunities for HH were observed, and the overall HH compliance rate was 94.1%. HH rates of physicians was lowest(83.4%; OR: 0.209, 95%CI:0.174-0.252). HH rates were statistically different by the job titles(p<0.001), WHO's 5 moments(p<0.001). HH rates in registered nurses(p=0.003), and medical technicians(p<0.001) were statistically different by the WHO 5Moments. Jobs specific HH strategies and WHO 5Moments should be developed to increase the HH compliances of the HCPs.

A Kinetics Analysis of Forward 11/2 Somersault on the Platform Diving (플랫폼 다이빙 앞으로 서서 앞으로 11/2회전 동작의 운동역학적 분석)

  • Jeon, Kyoung-Kyu
    • Korean Journal of Applied Biomechanics
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    • v.23 no.3
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    • pp.209-218
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    • 2013
  • This study was to perform the kinetic analysis of forward $1\frac{1}{2}$ somersault on the platform diving. Six men's diving players of the Korea national reserve athletes participated in this study. The variables were analyzed response time, velocity, center of mass (COM), angle, center of pressure (COP) and ground reaction force (GRF) of motion. For measure and analysis of this study, used to synchronized to 4 camcorder and 1 force plate, used to the Kwon3D XP (Ver. 4.0, Visol, Korea) and Kwon GRF (Ver. 2.0, Visol, Korea) for analyzed of variables. The results were as follows; Time factor were observed in maximum knee flexion depending on the extent of use at phase 1 of take-off to execute the somersault. This enabled the subject to secure the highest possible body position in space at the moment of jumping to execute the somersault and prepare for the entry into the water with more ease. Regarding the displacement of COM, all subjects showed rightward movement in the lateral displacement during technical execution. Changes in forward and downward movements were observed in the horizontal and vertical displacements, respectively. In terms of angular shift, the shoulder joint angle tended to decrease on average, and the elbow joints showed gradually increasing angles. This finding can be explained by the shift of the coordinate points of body segments around the rotational axis in order to execute the half-bending movement that can be implemented by pulling the lower limb segments toward the trunk using the upper limb segments. The hip joint angles gradually decreased; this accelerated the rotational movement by narrowing the distance to the trunk. Movement-specific shifts in the COP occurred in the front of and vertical directions. Regarding the changes in GRF, which is influenced by the strong compressive load exerted by the supporting feet, efficient aerial movements were executed through a vertical jump, with no energy lost to the lateral GRF.

An Efficient Facial Expression Recognition by Measuring Histogram Distance Based on Preprocessing (전처리 기반 히스토그램 거리측정에 의한 효율적인 표정인식)

  • Cho, Yong-Hyun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.5
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    • pp.667-673
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    • 2009
  • This paper presents an efficient facial expression recognition method by measuring the histogram distance based on preprocessing. The preprocessing that uses both centroid shift and histogram equalization is applied to improve the recognition performance, The distance measurement is also applied to estimate the similarity between the facial expressions. The centroid shift based on the first moment balance technique is applied not only to obtain the robust recognition with respect to position or size variations but also to reduce the distance measurement load by excluding the background in the recognition. Histogram equalization is used for robustly recognizing the poor contrast of the images due to light intensity. The proposed method has been applied for recognizing 72 facial expression images(4 persons * 18 scenes) of 320*243 pixels. Three distances such as city-block, Euclidean, and ordinal are used as a similarity measure between histograms. The experimental results show that the proposed method has superior recognition performances compared with the method without preprocessing. The ordinal distance shows superior recognition performances over city-block and Euclidean distances, respectively.

A Study on the Relationship Between Perceived Family Support & Self Concept of Cesarean Section Mothers (가족의 지지와 제왕절개술 산모의 자아개념간의 관계연구)

  • Chang, Myung-Ja;Lee, Mi-La
    • 모자간호학회지
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    • v.1
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    • pp.23-33
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    • 1991
  • Recently, Cesarean Section has been revealed as major events in maternity nursing, because it has influence on tile formatter of the self concept of cesarean section mothers as well as later coping mechanism and mother-child relationship including the mothering role. The study is conducted to clarify the relationships between the perceired family support and the self concept of cesarean section mothers, and to find out other Influencing factors on the formation of the self concept. Measuring instrument used in this study was Lee's scale to measure the self concept and the degree of perceived family support of the cesarean section mothers, The subject were 155 cesarean section mothers who were selected conveniently. Volunteers answered self reporting questionnaires which asked about their self concept. Data was analyzed as follows using SAS. The relationship between scores of the self concept and degree of the perceived family support was analyzed by Pearson's product moment correlation. In order to identify the influencing effects of demographic variables on the formation of self concept & F test were used. Result were summarized as follows : 1. Scores of self concept of cesarean section mothers were significantly correlated with scores of the perceived family support (r=0.3438, p<0.01) These results show that the family support is closely related to the self concept of cesarean mothers and has positive effects on their coping capacity. 2. Scores of self-concept of those who have lower ducation background and are multipara were significantly higher than those who have higher education background and are primipara(M=29.90$\pm$9.37, 27.69$\pm$3.89, t=2.006, df=105.8, p=0.0480: M=27.75$\pm$3.49. 29.46$\pm$8.68, t=-1.7183, 2. p=0.08).

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