• 대한인간공학회지
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• 제28권3호
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• pp.95-102
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• 2009

Ten young females were participated in this study to investigate the effects of types of shoes (sneakers, high heels, kill heels), types of tasks (standing, walking floor, step up and down), and areas of foot (fore foot, middle foot, rear foot) on foot pressures as well as subjective discomfort ratings. Results showed that kill heels had the most discomfort shoes, followed by high heels and sneakers. Generally, as the heel was higher, the discomfort of foot increased. For the analyses of task types, generally discomfort ratings were highest for the step down and up, followed by walking floor and standing. Especially discomfort ratings of high heels and kill heels were more evident in case of step up and step down than standing and walking floor. Standing task was rated as the lowest levels of discomfort on users' foot. Peak and mean foot pressures were also evaluated in this study. The findings represented that there was no significant differences between types of shoes in both peak and mean foot pressures. The peak pressure (82.14kPa) and mean pressure (40.32kPa) for standing task were significantly lower than those of other tasks [walking floor (190.55kPa, 55.46kPa), step up (191.43kPa, 53.80kPa), and step down (200.66kPa, 52.62kPa)]. Generally discomfort ratings and peak/mean pressures associated with foot showed that fore foot had higher discomfort ratings as well as peak and mean pressures than middle and rear foots. In particularly, this trend was more obvious in case of high heels and kill heels. For the high heels and kill heels, the peak pressures of fore foot were 4.5~4.8 times and 2.3~2.5 times greater than that of middle foot and rear foot, respectively, whereas the peak pressures of fore foot were 2.9 times and 1.7 times greater than that of middle and rear foots, respectively, in case of sneakers.

• 대한물리치료과학회지
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• 제11권4호
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• pp.29-37
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• 2004

Measurements of plantar pressure provide an indication of foot and ankle function during gait and other functional activities because the foot and ankle provide necessary support and flexibility for weight bearing and weight shifting while people are performing these activities. Plantar pressure is being increasingly used in both research and clinical practice to measure the effects of various footwear and physical therapy intervention. The influence of walking speed and ground inclination on plantar pressure parameters However has not been evaluated in detail. So, in this study to determine the effect of changes in walking speed and ground inclination on plantar pressure treadmills with different walking speeds and inclination were used. Plantar pressure parameters were measured with the Parotec system using the walking and running in 20 healthy participants(10 male, 10 female) aged $20{\sim}28$(mean 22.22, S.D.2.26 years) when slow walking and running. The result of this study with increased die walking speed, the peak pressure of 1st, 5th metatarsal head and total contact time and impulse total at the forefoot was affected by walking speed; however, die peak pressure, contact time and impulse total at the forefoot was not affected by ground inclination.

• Wind and Structures
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• 제2권4호
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• pp.253-266
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• 1999

This paper presents the effects of free-stream turbulence on streamwise surface pressure fluctuations on two-dimensional rectangular cylinders. Particular attention is given to possible effects of turbulence integral scale on fluctuation and peak pressures. The mean, standard deviation, peak pressure coefficients, spectra and cross-correlation of fluctuating pressures were measured to investigate the nature of the separation and reattachment phenomenon in turbulent flows over a wide range of turbulence intensity and integral scale.

• Tuberculosis and Respiratory Diseases
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• 제45권5호
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• pp.1022-1030
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• 1998

연구배경: Volume controlled ventilation(VCV)시 inspiratory pause의 사용은 흡기시간을 연장하여 평균기도압을 상승시키고 가스교환을 호전시키는 것으로 알려져 있다. 그러나 같은 흡기시간을 유지하더라도 inspiratory pause를 사용하였을 경우 평균기도압과 가스교환의 변화에 대하여는 잘 알려지지 않았다. 방 법: 저자들은 VCV으로 기계호흡을 받는 12명의 환자를 대상으로 흡기산소농도, 상시호흡량, 호흡수 및 I : E ratio(1 : 3)는 변화시키지 않고 5%의 pause를 사용한 경우와 사용하지 않은 경우의 기도압 및 가스교환의 변화를 관찰하여 비교하였다. 결 과: 동맥혈 이산화탄소분압은 pause를 사용한 경우 $38.6{\pm}7.4$ mmHg로 시용하지 않은 경우의 $41.0{\pm}7.7$ mmHg보다 유의하게 낮았다 (p<0.01). 동맥혈 산소분압은 pause를 사용한 경우 $94.4{\pm}23.2$ mmHg로 사용하지 않은 경우의 $91.8{\pm}19.7$ mmHg보다 높은 경향이 있었으나 (p=0.054), 폐포-동맥혈 산소분압차$(P(A-a)O_2)$는 pause 유무에 따른 차이가 없었다 ($185.3{\pm}86.5$ mmHg vs. $184.9{\pm}84.9$ mmHg, P=0.766). 평균기도압은 pause를 사용한 경우 $9.7{\pm}4.0\;cmH_2O$로 사용하지 않은 경우의 $8.8{\pm}4.0\;cmH_2O$보다 유의하게 높았다 (p<0.01). Pause를 사용했을 때의 pause pressure와 pause를 사용하지 않을 때의 최고흡기압의 차이는 호흡기계의 저항과 역상관관계를 보였으나 (r=-0.777, p<0.01), pause가 없을 때의 최고흡기압에서 pause를 사용했을 때의 최고흡기압으로의 증가는 호흡기계의 저항과 정상관관계를 보여 (r=0.811, p<0.01), 평균기도압의 차이는 호흡기계의 저항과 유의한 정상관관계를 보였다(r=0.681, p<0.05). 평균기도압의 변화는 $PaCO_2$의 변화와 상관관계를 보이지 않았다. 결 론: Volume control ventilation시 동일한 1:3 의 I:E ratio하에서라도 5%의 inspiratory pause를 사용하는 것이 평균기도압을 더 높게 유지할 수 있으며 폐환기를 호전시킬 수 있는 것으로 사료되었다. 또한 호흡기계의 저항이 증가되어 있을수록 평균기도압의 상승이 많았으나 평균기도압의 상승 정도는 폐환기의 변화와 상관관계를 보이지 않았다.

• Wind and Structures
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• 제8권5호
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• pp.357-372
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• 2005

Mean and extreme pressure distributions on a large cantilevered flat roof model are measured in a boundary layer wind tunnel. The largest peak suction values are observed from pressure taps beneath conical "delta-wing type" corner vortices that occur for oblique winds, then the characteristics and causes of the local peak suctions are discussed in detail. Power spectra of fluctuating wind pressures measured from some typical taps located at the roof edges under different wind directions are presented, and coherence functions of fluctuating pressures are also obtained. Based on these results, it is verified that the peak suctions are highly correlated with the conical vortices. Furthermore, according to the characteristics of wind loads on the roof, an aerodynamic solution to minimize the peak suctions by venting the leading edges and the corners of the roof is recommended. The experimental results show that the suggested strategy can effectively control the generation of the conical vortices and make a reduction of 50% in mean pressures and 25% in extreme local pressures at wind sensitive locations on the roof.

• The Journal of Korean Physical Therapy
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• 제13권3호
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• pp.537-549
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• 2001

The isometric torque of the elbow flexor and extensor muscles were measured for 6 seconds at a joint angle of 90$^{\circ}$ , in 10 normal subjects (control group) and 10 hemiplegic subjects(patient group), using the Cybex NORMTM System. The peak torque, the time to peak torque were measured for each exercise. In addition, heart rate and blood pressure were recorded simultaneously at rest and immediately following exercise completion at 1 and 3m mutes. Statistical analysis was performed using SPSS 8.0 for Windows software and mean and standard deviations were calculated. The results are as follows. 1) In the patient involved group. the isometric values for flexors and extensors were significantly lower than in the normal nondominant group(p<.05). 2) The extensor to flexor strength ratio in the isometric mode was 121.0% in the patient involved group compared with 78.7%in the normal nondominant group, a significant difference(p<.05). 3) The mean increment ratio was increased 19.0% for systolic blood pressure and 25.2% for disatolic blood pressure in the patient group. 4) The mean increment ratio was increased 36.0% heart rate in the patient group.

• 한국기계가공학회지
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• 제20권6호
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• pp.114-120
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• 2021

This study is focused on the root mean square and peak-to-valley based on the injection conditions of the f-theta lens, one of the main components of laser printers and laser scanning systems. The f-theta lens of an aspherical plastic lens requires ultra-preaction. Injection molding is typically used for the mass production of aspherical plastic lenses. In the injection-molding method, the resin in the lens shape is filled with the resin after melting the plastic pellets at a constant temperature and then cooled. It is necessary to maintain a uniform injection molding system to produce high-quality lenses. These injection-molding systems are influenced by different factors, such as pressure, speed, temperature, mold, and cooling. It is possible to obtain a lens that exhibits the optical characteristics required to achieve harmony. We investigated the root mean square and peak-to-valley caused by variations in temperature, a critical parameter in the melting and cooling of plastic resins generated inside and outside the injection mold.

• Wind and Structures
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• 제7권6호
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• pp.359-372
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• 2004

Wind tunnel model studies were carried out to determine the wind load distribution on tributary areas near the gable-end of large, low-rise buildings with high pitch planar and curved roof shapes. Background pressure fluctuations on each tributary area are described by a series of uncorrelated modes given by the eigenvectors of the force covariance matrix. Analysis of eigenvalues shows that the dominant first mode contributes around 40% to the fluctuating pressures, and the eigenvector mode-shape generally follows the mean pressure distribution. The first mode contributes significantly to the fluctuating load effect, when its influence line is similar to the mode-shape. For such cases, the effective static pressure distribution closely follows the mean pressure distribution on the tributary area, and the quasi-static method would provide a good estimate of peak load effects.

• 한국운동역학회지
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• 제20권3호
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• pp.337-344
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• 2010

This study was conducted on male college students with pronated foot to measure the foot pressure by having them wear three kinds of mid-sole wedge ($0^{\circ}$, $5^{\circ}$, $10^{\circ}$). Maximum force, foot contact area, mean pressure and peak pressure were measured using a foot pressure distribution measuring instrument. And the surface of the foot sole was divided into 10 areas. Regarding maximum force, there were statistically significant difference in the area 3 of the middle foot(p<.05). Regarding the foot contact area, it appeared broad in the outside area(1, 3, 5) of the foot according to mid-sole wedge, and there was statistically significant difference in the area 1 of the rear foot(p<.05) and the area 3 of the middle foot(p<.05). Mean pressure by foot area decreased in the inside of the foot according to mid-sole wedge, and there was statistically significant difference in the area 2 of the rear foot(p<.05) and the area 3 of the middle foot(p<.05). Regarding the peak pressure by foot area, the pressure roughly decreased in the inside area(2, 4, 7) of the foot according to mid-sole wedge, and there was statistically significant difference in the area 1(p<.05), 2(p<.05) of the rear foot and the area 3 of the middle foot(p<.05).

• 수산해양교육연구
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• 제22권4호
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• pp.508-515
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• 2010

This study was conducted on male college students with supinated foot to measure the foot pressure by having them wear three kinds of wedge insoles ($0^{\circ}$, $3.5^{\circ}$, $7^{\circ}$). Foot contact time, foot contact area, peak pressure and mean pressure were measured using a foot pressure distribution measuring instrument. And the surface of the foot sole was divided into 10 areas. Regarding foot contact time, there was no statistically significant difference by showing $0.69{\pm}0.004$ seconds at $3.5^{\circ}$ and $0.68{\pm}0.006$ seconds at $0^{\circ}$ and $7^{\circ}$. Regarding the foot contact area, it appeared broad in the inside area of the foot according to wedge insole, and there was statistically significant difference in the area 1 of the rear foot(p< .01) and the area 3 of the middle foot(p< .05). The peak pressure by foot area decreased in the outside of the foot according to wedge insole, while increasing in the inside of the foot. Among the areas, there was statistically significant in the area 2 of the rear foot (p< .01) and the area 3 of the middle foot (p< .05). Regarding the mean pressure by foot area, the pressure roughly increased in the inside area of the foot according to wedge insole, while decreasing in the outside of the foot.