• 제목/요약/키워드: pressure pattern

검색결과 1,539건 처리시간 0.022초

치과정밀주조에 활용되는 Air-Vent의 효과에 관한 연구 (A Study on The Effect of Air-Vent Utilized to Dental Precision Casting)

  • 김부섭
    • 대한치과기공학회지
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    • 제16권1호
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    • pp.5-11
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    • 1994
  • On purpose of relative comparison of between air-vent attached pattern and non attached one, casting tests were accomplished by castability analysis unrig wax screen mesh pattern. Experimental specimens are divided Into 4groups. 1) Air-vent attached pattern with high casting pressure(coil spring type centrifugal casting machine 2.5turn). 2) Air-vent attached pattern with low casting pressure(coil spring type centrifugal casting machine 1.5turn). 3) Air vent non attached pattern with high casting pressure(coil spring type centrifugal casting machine 2.5turn). 4) Air-vent non attached pattern with low casting pressure(coil spring type centrifrgal casting machine 1.5turn). The main results are as follows : 1) The condition of high casting pressure no.1, no.3 were showed perfect castability. 2) The condition of low-casting pressure, there is a wide difference between no.2, no.4 group. Castability of no.2 group preferable to no.4 group(p<0.001). 3) Low casting pressure and complex shape cause the low-castability. So it is recommanded that use of air-vent in case of complex shaped wax pattern with low easting pressure.

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앉은 자세에서 탄력밴드를 이용한 PNF 팔 패턴의 방산효과가 골반의 압력에 미치는 영향 (The Relationship of Pelvic Pressure and Irradiation of the PNF Upper Arm Pattern in the Sitting Position with an Elastic Band -A Randomized Control Trial-)

  • 양재만;여고은;김동욱;이정훈
    • PNF and Movement
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    • 제17권3호
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    • pp.421-429
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    • 2019
  • Purpose: This study evaluated the relationship between pelvic pressure and irradiation of the proprioceptive neuromuscular facilitation (PNF) upper arm pattern exercises with an elastic band while in a sitting position. Methods: Fourteen subjects with asymptomatic pelvic pressure participated in this study. Pelvic pressure was measured using a Gaitview® system while sitting and performing PNF bilateral upper arm patterns. Resistance strength was provided by the blue elastic band. The statistical significance of the results was evaluated using a repeated one-way ANOVA and the independent t-test. The Bonferroni method was used for the post-hoc test. Results: The results revealed a significant change in the pelvic pressure when performing the PNF arm pattern. The average resistance pressure on the pelvis, with the elastic band, significantly increased after the initial sitting position (F=3.91, 3.92; p<0.05). No significant pelvic pressure changes were noted for each PNF upper arm pattern (p>0.05). Conclusion: The results of this study showed a positive relationship between pelvic pressure and the irradiation of PNF upper arm pattern exercises with resistance in the sitting position.

신체동작과 의복여유분에 따른 의복압에 대한 탐색적 연구 -견갑골$\cdot$상지를 중심으로- (A Study on the Clothing Pressure variation according to arm movement and ease of basic pattern)

  • 조정미;김혜경
    • 한국의류학회지
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    • 제11권1호
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    • pp.11-19
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    • 1987
  • The objectives of this study were: 1. To investigate the relationship between arm movement and clothing pressure in the upper arm and shoulder blade area. 2. To find out the relationship between ease of basic pattern and clothing pressure in the upper arm and shoulder blade area. 3. To study any interaction between arm movement and ease of clothing on the clothing pressure. This study was an experimental research using the measuring devices of clothing pressure. The subjects were the unmarried college women. Arm movements were 3 types($45^{\circ}$, $90^{\circ}$, $135^{\circ}$) to the horizontal direction. The ease of basic pattern in the breast was 3 types(4 cm, 6 cm, 8cm). The statistical analyses used in this study included mean, standard deviation and one-way analysis of variance. The results obtained from this research were as follows; 1. The whole clothing pressure increased as the angle of the arm movement increased. Part of upperarm and shoulder blade above axillar gave high clothing pressure while part of upperarm and shoulder blade above upper breast, low pressure. Difference between highest clothing pressure and lowest clothing pressure increased as the arm movementdid. 2. The whole clothing pressure increased as the ease of the basic pattern in breast decreased. No matter how the ease of basic pattern in the breast area varied, the Points where generally showed high and low pressure were identical. 3. The whole arm pressure increased as the movement angle increased and the ease of pattern in breast area decreased. Difference between highest clothing pressure and lowest clothing pressure increased as the movement angle increased and the ease decreased.

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인체의 3차원 스캔 데이터를 이용한 밀착 바디 슈트 개발 (2D Pattern Development of Tight-fitting Bodysuit from 3D Body Scan Data for Comfortable Pressure Sensation)

  • 정연희
    • 한국생활과학회지
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    • 제15권3호
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    • pp.481-490
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    • 2006
  • Adjusting pressure level in the construction of athletes' tight-fitting garments by reducing the elastic knit pattern is a challenging subject, which influences the performance of the wearer directly. Therefore, in this study, relationship between the reduction rates of the basic pattern obtained from 3D human scan data and resultant clothing pressure was explored to improve the fit and pressure exerted by clothing. 3D scan data were obtained using Cyberware and they were transformed into a flat pattern using software based on Runge-Kutta method. Reduction rate was examined by subjective wear test as well as objective pressure measurement. As a result, difference in the length between the original 3D body scan data and the 2D tight-fitting pattern was 0.02$\sim$0.50cm (0.05$\sim$1.06%), which was within the range of tolerable limits in making clothes. Among the five garments, the 3T-pattern was superior in terms of subjective sensation and fit. The pressure of the 3T pattern was 2$\sim$4 gf/cm2 at five locations on the body, which is almost the same or a bit higher than that of Z-pattern. In the case of tight-fitting overall garment, the reduction rate of the pattern in the wale direction is more critical to the subjective sensation than the course direction. It is recommended that the reduction grading rules of course direction should be larger than that of Ziegert for a better fit of tight-fitting garments. In the case of wale direction, however, reduction grading rule should be kept the same as suggested earlier by Ziegert (1988).

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3D 스캔 데이터를 이용하여 개발된 사이클 팬츠 패턴의 축소율에 따른 의복압 및 주관적 착의 평가 (Subjective Wearing Assessment and Clothing Pressure depending on the Pattern Reduction Rate of Developed Cycle Pants Using the 3D Human Scan Data)

  • 정연희;홍경희
    • 한국생활과학회지
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    • 제24권2호
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    • pp.255-266
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    • 2015
  • In this study, we have developed the ergonomic pattern from the 3D human body reflecting cycling posture and extensibility of the stretch fabrics. Adjusting pressure level in the construction of athlete's tight-fitting stretch garments by reducing the original pattern is a challenging subject, which influence on the performance of the wearer directly. Therefore, in this study, relationships between the reduction rates of the 2D pattern obtained from the 3D human scan and resultant clothing pressure were explored to improve the fit and pressure exerted by reduced clothing pattern. Subjective wear sensations of the experimental garments were rated using a seven-point Likert scale on two consecutive days. While wearing the garments, subjects were asked to take five different postures including waist flexion, sitting and others. A Likert-type scale was used for the evaluation, with 7 points indicating the best fit in tight-fitting pants. Comparing 2/3T-pattern with T-pattern, the latter was superior to 2/3T-pattern in terms of adhere well to the waist and hip area in the 0.032 significance level. T-pattern was superior to 2/3T-pattern in terms of fitting and wear comfort. As results, the pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the skin while cycling posture, so that the extra ease for movement and good fit was not need to be considered. The optimized reduction rates were determined with the proposed reduction rate, the resultant pressure range was within the range of $0.5{\sim}3.0gf/cm^2$ at eight locations on the body except front waist band and thigh band.

Flow Pattern and Pressure Drop of Pure Refrigerants and Their Mixture in Horizontal Tube

  • Lim, Tae-Woo
    • Journal of Mechanical Science and Technology
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    • 제19권12호
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    • pp.2289-2295
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    • 2005
  • Two-Phase flow pattern and pressure drop data were obtained for pure refrigerants R134a and R123 and their mixtures as test fluids in a horizontal tube. The flow pattern is observed through tubular sight glasses located at inlet and outlet of the test section. The flow map of Baker developed for air-water two-phase flow at atmospheric pressure failed to predict the observed flow patterns at the higher value of the mass velocity used in the present study. The map of Kattan et al. predicted the data well over the entire region of mass velocity selected in the present study. The measured pressure drop increased with an increase in vapor quality and mass velocity. A new two-phase multiplier was developed from a dimensional analysis of the frictional pressure drop data measured in the present experiment. This new multiplier was found successfully to correlate the frictional pressure drop.

열 나노임프린트 공정에서 가압조건이 패턴전사에 미치는 영향 (Effects of Pressurization Conditions on the Pattern Transfer in the Thermal Nanoimprint Lithography)

  • 이우영;이기연;김국원
    • 반도체디스플레이기술학회지
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    • 제12권4호
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    • pp.15-20
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    • 2013
  • Nanoimprint lithography (NIL) is the next generation photolithography process in which the photoresist is dispensed onto the substrate in its liquid form and then imprinted and cured into a desired pattern instead of using traditional optical system. There have been considerable attentions on NIL due to its potential abilities that enable cost-effective and high-throughput nanofabrication to the display device and semiconductor industry. In this paper, a pressure vessel type imprinting system was used to imprint patterns with two type pressure values (25 bar, 30 bar) and two type pressure keeping times (5 min, 10 min). The height of transferred pattern and the thickness of residual layer were measured and effects of pressurization conditions - pressure and pressure keeping time - on the pattern transfer in thermal NIL were investigated.

Effect of the Gravity Forces on Flow Pattern and Frictional Pressure Drop in Two-Phase, Two-Component Flow

  • Choi, B.-H;Han, W.-H
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권2호
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    • pp.338-346
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    • 2004
  • Experimental data on the effect of the variable gravity magnitude, namely microgravity, normal gravity and hyper-gravity, on flow pattern and frictional pressure drop were obtained during co-current air-water flow in a horizontal tube, The flow patterns were found to depend strongly on the gravity magnitude and certain flow pattern were found to depend on the gas superficial velocity. The effect of the gravity magnitude had an effect on the frictional pressure drop only at low flow rates. The present data are used to evaluate some of existing flow pattern transition and pressure drop models and correlations.

양이 각각 두 개의 보청기 마이크로폰을 장착한 KEMAR 머리 모델의 양이 방향성 측정 (Binaural Directivity Pattern Measurements of the KEMAR Head Model with Two Twin Hearing Aid Microphones)

  • 장순석;권유정;이제형
    • The Journal of the Acoustical Society of Korea
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    • 제25권1E호
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    • pp.25-31
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    • 2006
  • Two twin microphones may produce particular patterns of binaural directivity by time delays between the twin microphones. The boundary element method (BEM) was used for the simulation of the sound pressure field around the KEMAR head model in order to quantify the acoustic head effect. The sound pressure onto the microphone was calculated by the BEM to an incident sound pressure. Then a planar directivity pattern was formed by four sound pressure signals from four microphones. The optimal binaural directivity pattern may be achieved by adjusting time delays at each frequency while maintaining the forward beam pattern is relatively bigger than the backward beam pattern. The simulation results were verified by the experimental measurement.

Binaural Directivity Pattern Simulation of the KEMAR Head Model with Two Twin Hearing Aid Microphones by Boundary Element Method

  • Jarng Soon Suck;Kwon You Jung;Lee Je Hyeong
    • The Journal of the Acoustical Society of Korea
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    • 제24권3E호
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    • pp.115-122
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    • 2005
  • Two twin microphones may produce particular patterns of binaural directivity by time delays between twin microphones. The boundary element method (BEM) was used for the simulation of the sound pressure field around the head model in order to quantify the acoustic head effect. The sound pressure onto the microphone was calculated by the BEM to an incident sound pressure. Then a planar directivity pattern was formed by four sound pressure signals from four microphones. The optimal binaural directivity pattern may be achieved by adjusting time delays at each frequency while maintaining the forward beam pattern is relatively bigger than the backward beam pattern.