• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2001.06a
• /
• pp.231-235
• /
• 2001

This paper has been presented the dynamic effect by the journal speed. eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing the two row source position of air bearing is different from previous investigations in the side of pressure distribution of air film by the wedge effects. These optimal chooses of the two row source positions enable us to improve the performance of the film reaction force and loading force as making the high speed spindle. The results of investigated characteristics may be applied to precision devices like ultra-precision grinding machine and ultra high speed milling.

• Phonetics and Speech Sciences
• /
• v.14 no.4
• /
• pp.11-17
• /
• 2022

This study investigates closure durations of Korean stops in terms of laryngeal contrasts, places of articulation, and three positions within words. Twenty-two Korean speakers produced the nonsense words containing Korean stops found in word-initial and word-final positions and between vowels. The statistical results showed that the closure durations differed significantly by laryngeal contrast and place of articulation. In addition, the differences by position within words were marginally significant. The closure durations were in the order of lenis < aspirated < fortis stops by laryngeal contrast, velar < alveolar < bilabial stops by place of articulation, and word-final < word-initial < between vowels by positions within words. The laryngeal contrasts were neutralized in word-final position as per coda neutralization in Korean phonology. This study shows that closure durations should be considered a valuable phonetic cue to identify stops on par with voice onset time and f0.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.22 no.2
• /
• pp.315-327
• /
• 1992

The purpose of this study was to evaluate the utilization of the orthopantomograph as a diagnostic aid to observe maxillary sinus and adjacent structures. For achieving this goal. the lead plates were attached to the five walls of the maxillary sinus of a human dry skull. The dry skull was placed in fourteen different positions; standard. 20mm forward. 20mm backward. 10 degree upward. 10 degree downward. 20mm lateral. forward & upward, forward & downward. forward & lateral. backward & upward. backward & downward, backward & lateral. upward & lateral. downward & lateral position. The obtained results were as follows: 1. The image of the medial wall was observed very differently according to the head positions. 2. The image of the anterior wall was observed at medial third to half of the maxillary sinus in each head position. 3. the image of the posterior wall was always observed at lateral third of the maxillary sinus in all head positions and more obviously in the downward-lateral position. 4. The image of the superior wall was observed at the inferior third to half of the orbit in each head position. 5. The image of the inferior wall was always observed at the inferior third of maxillary sinus in all head positions and observed more obviously in the standard and downward-lateral positions. 6. The images of the zygomatic process. zygomatic arch and zygomaticotemporal suture were observed very well in the downward-lateral position.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.16 no.2
• /
• pp.18-27
• /
• 2010

Purpose: This study is to identify the muscle fatigue and pain by various cervical positions in the VDT work. Methods: Twenty two volunteers (11 males and 11 females) participated in this study. Each subject gazes monitor in front of them for thirty minutes in the three cervical positions (neutral, 30 degree flexed, and 30 degree extended positions). Visual analogue scale (VAS) for the pain and pressure pain threshold(PPT) of the trapezius and levator scapula for the muscle fatigue were measured every fifteen minutes. Results: VASs after 15 minutes were $1.23{\pm}0.43$ in neutral, $3.0{\pm}0.93$ in flexed, and $5.27{\pm}1.03$ in extended position respectively and increased to $1.5{\pm}0.67$, $4.59{\pm}1.26$, and $7.73{\pm}0.98$ after 30 minutes. The order of magnitude of VAS was extended, flexed, and neutral position(p<0.01). PPTs in both sides of upper trapezius and levator scapula muscles were decreased at the three positions after 15 and 30 minutes respectively(p<0.01). There were no statistical differences of PPTs in neutral and flexed positions after 15 and 30 minutes(p<0.01). Extended position showed lowest PPTs in both side of upper trapezius and levator scapula muscles after 15 and 30 minutes(p<0.01). There were statistical differences of PPTs in extended position and the other two positions after 15 and 30 minutes(p<0.01). Conclusion: The cervical position that has the most influence on the cervical muscle fatigue and pain in the VDT work is extended position.

• Journal of Korean Physical Therapy Science
• /
• v.25 no.2
• /
• pp.47-54
• /
• 2018

Purpose: The purpose of this study was to investigate the most effective exercise position of Latissimus dorsi's activities during Pull up, Push up and Lat pull down among few positions of hand grips(pronation, Supination and neutral grip) and grip widths(30cm, 60cm) based on EMG activities. Method: 10 healthy adults were participated in this study and the surface EMG activities of the Latissimus dorsi were measured during Pull up, Push up and Lat pull down exercise according to specific hand grip and grip width positions. The maximum and mean value of Latissimus dorsi's EMG activities at all positions were recorded and analysed by ONE-WAY REAPTED ANOVA. Results: The showed that the most Latissimus dorsi's activities is during Pull up exercise. Main results are as follows 1)maximum value: For Pull up, among all studied positions, Rt Latissumus dorsi, position of Supinated grip and 60cm grip width showed strongest muscle activation based on maximum EMG value. Statistical significance was assumed at p<.05. 2)mean value: For Pull up, among all studied positions, Both Latissimus dorsi, position of pronated grip and 60cm grip width showed strongest muscle activation based on mean EMG value. Statistical significance was assumed at p<.05. Conclusion: Therefore, taking the results of this study, Pull up exercise would be the best exercise of Latissimus dorsi's activation. It is recommended to do in pronated grip position and 60cm grip width during Pull up to make body fit.

• Journal of Technologic Dentistry
• /
• v.20 no.1
• /
• pp.61-89
• /
• 1998

Having taken as cause of dental technicians separation from their service a variety of individual idiosyncrasies, function-related factors, external environment factors, functional satisfaction, organizational commitment, and intention to remain, the present study conducted a mail questionnaire poll and interviews on those dental technicians who are mow in the service with private dental technical workshops and dental technical workshops in general hospitals and private dental clinics. The resultant findings from analysis of the repondent's general characteristics of cause of separation form service were revealed, as follows : 1) It was shown that the higher the academic career, the considerably higher cause of position commitment among causes of individual idio-syncrasies, reflecting a statistically significant result(P<0.05) 2) The less the number of working hours as viewed from the average number of working hours per day, the higher the positive emotion, reflecting a significant relation(P<0.01) 3) Causes from performing duties among function-related causes diclosed a statistically significant relation among marital status, career, monthly income, and positions(P<0.01) 4) Causes from wages showed a statistically significant relation in the average number of working hours per day(P<0.01), monthly income(P,0.05), and positions(P<0.05) 5) Causes from supervision exposed a significant relation in workplaces(P<0.01) 6) Causes from promotion represented a significant relation in positions(P<0.001) 7) Causes from opportunnities for taking a job as seen from external environment causes also disclosed a statistically significant relation in workplaces(P<0.05) 8) Reponsibility for family sustenace reflected a statistically significant relation in sex, age, marital status, career, monthly income, work fields, term of employment, positions, and experience of separation(P<0.001) 9) Functional satisfaction showed a statistically significant relation in marital status, career, monthly income, and the average number of hours a day(P<0.05) 10) Oraganizational commitment disclosed a statistically significant relation in work experience, monthly income, term of employment, positions(P<0.05) and the average number of working hours a day(P<0.001) 11) The intention to remain indicated a statistically significant relation in age, marital status, work experience, monthly income, positions(P<0.001) and term of employment. the average number of working hours a day(P<0.01), and in the performing work field(P<0.05)

• Journal of Environmental Science International
• /
• v.23 no.7
• /
• pp.1307-1320
• /
• 2014

A number of problems associated with environmental noises in urban areas have significantly been considered. Specific measurement and estimation of the environmental noise became a primary issue in local governments. Environmental noise monitoring system is required in order to estimate and verify the a city noise map. However, current monitoring positions may not perfectly represent and incorporate many different view points, such as districts of a city, different utilizations of a city by the law, populations, and classifications and traffics of roads. In addition, scientific method to provide specific noise monitoring positions my not be avaliable in current literature. For this reason, the primary objective of this paper is to propose a new method for introducing a number of monitoring positions in the entire city. First, the quality function deployment (QFD) method was utilized to simultaneously represent both districts and utilizations of a city. Second, a new algorithm to find a number of monitoring positions was proposed by compromising many different view points: populations, classifications of roads and areas, and traffics of roads. Finally, the proposed monitoring positions and a sample noise map was provided for verification purposes. Based on these results, the proposed algorithm including the QFD concept may successfully provide specific noise monitoring positions by simultaneously consider may different view points and requirements of a city.

• Physical Therapy Korea
• /
• v.8 no.2
• /
• pp.73-85
• /
• 2001

The purpose of this study was to investigate whether the standing balance could be influenced by the different foot positions. Seventeen patients with hemiplegia were tested for the static and dynamic balance under the different foot positions. In the balance test, subject stood by bearing weight on one foot, and the other foot was positioned in three different positions (symmetric, $45^{\circ}$ anterolateral, and anterior position). This study used the Kinesthetic ability trainer (KAT2000) to measure the standing balance. The results were as follows: 1) There were significant differences in the static standing balance in different foot positions with both weight-bearing on the paretic limb and on the nonparetic limb (p<.05). 2) There were also significant differences in the dynamic standing balance in different foot positions with both weight-bearing on the paretic limb and on the nonparetic limb (p<.05). 3) There was a significant difference when the paretic weight-bearing and the nonparetic weight-bearing were compared (p<.01). 4) when the paretic weight-bearing and the nonparetic weight-bearing were compared, anterior foot position showed a significant difference in the dynamic standing balance (p<.05), but $45^{\circ}$ anterolateral foot position did not show a significant difference (p>.05). In this study, the standing balance showed a significant difference according to different foot positions in hemiparetic patients, and standing balance was better when they stood by bearing weight on the nonparetic limb. These results indicate that it is a necessary to consider both weight-bearing limb and foot position not only in the rehabilitation program but also in achieving the stability in the independent life.

• Journal of Neurogastroenterology and Motility
• /
• v.24 no.4
• /
• pp.570-576
• /
• 2018

Background/Aims Swallows with viscous or solid boluses in different body positions alter esophageal manometry patterns. Limitations of previous studies include lack of standardized viscous substrates and the need for chewing prior to swallowing solid boluses. We hypothesize that high-resolution impedance manometry (HRiM) using standardized viscous and super-viscous swallows in supine and upright positions improves sensitivity for detecting esophageal motility abnormalities when compared with traditional saline swallows. To establish normative values for these novel substrates, we recruited healthy volunteers and performed HRiM. Methods Standardized viscous and super-viscous substrates were prepared using "Thick-It" food thickener and a rotational viscometer. All swallows were administered in 5-mL increments in both supine and upright positions. HRiM metrics and impedance (bolus transit) were calculated. We used a paired two-tailed t test to compare all metrics by position and substrate. Results The 5-g, 7-g, and 10-g substrates measured 5000, 36 200, and 64 $700mPa{\cdot}sec$, respectively. In 18 volunteers, we observed that the integrated relaxation pressure was lower when upright than when supine for all substrates (P < 0.01). The 10-g substrate significantly increased integrated relaxation pressure when compared to saline in the supine position (P < 0.01). Substrates and positions also affected distal contractile integral, distal latency, and impedance values. Conclusions We examined HRiM values using novel standardized viscous and super-viscous substrates in healthy subjects for both supine and upright positions. We found that viscosity and position affected HRiM Chicago metrics and have potential to increase the sensitivity of esophageal manometry.

• PNF and Movement
• /
• v.19 no.2
• /
• pp.215-223
• /
• 2021

Purpose: This study aimed to compare the contraction ratios of the abdominal muscles and the preferential activation ratios of the transversus abdominis muscle (TrA) during the abdominal drawing-in maneuver (ADIM) in the hook-lying, sitting, and standing positions. Methods: This study included 30 healthy participants. The thicknesses of the TrA, internal oblique muscle (IO), and external oblique muscle (EO) were measured at rest and during the ADIM in the hook-lying, sitting, and standing positions using B-mode ultrasound imaging. The contraction ratios of these muscles and the preferential activation ratios of the TrA were calculated for each position. Results: The contraction ratio of the TrA and preferential activation ratio of the TrA during the ADIM in the hook-lying position were significantly higher than those in the sitting and standing positions (p < 0.05). The contraction ratio of the TrA during the ADIM in the sitting position was significantly higher than that in the standing position (p < 0.05). Conclusion: The hook-lying position tended to facilitate TrA activity better than the sitting position. Furthermore, the sitting position tended to facilitate TrA activity better than the standing position. These findings suggest that the ADIM in the hook-lying position should be implemented before that in the sitting position and that the ADIM in the sitting position should be implemented before that in the standing position.