• Title/Summary/Keyword: rotation period

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Seismic deformation demands on rectangular structural walls in frame-wall systems

  • Kazaz, Ilker
    • Earthquakes and Structures
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    • v.10 no.2
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    • pp.329-350
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    • 2016
  • A parametric study was conducted to investigate the seismic deformation demands in terms of drift ratio, plastic base rotation and compression strain on rectangular wall members in frame-wall systems. The wall index defined as ratio of total wall area to the floor plan area was kept as variable in frame-wall models and its relation with the seismic demand at the base of the wall was investigated. The wall indexes of analyzed models are in the range of 0.2-2%. 4, 8 and 12-story frame-wall models were created. The seismic behavior of frame-wall models were calculated using nonlinear time-history analysis and design spectrum matched ground motion set. Analyses results revealed that the increased wall index led to significant reduction in the top and inter-story displacement demands especially for 4-story models. The calculated average inter-story drift decreased from 1.5% to 0.5% for 4-story models. The average drift ratio in 8- and 12-story models has changed from approximately 1.5% to 0.75%. As the wall index increases, the dispersion in the calculated drifts due to ground motion variability decreased considerably. This is mainly due to increase in the lateral stiffness of models that leads their fundamental period of vibration to fall into zone of the response spectra that has smaller dispersion for scaled ground motion data set. When walls were assessed according to plastic rotation limits defined in ASCE/SEI 41, it was seen that the walls in frame-wall systems with low wall index in the range of 0.2-0.6% could seldom survive the design earthquake without major damage. Concrete compressive strains calculated in all frame-wall structures were much higher than the limit allowed for design, ${\varepsilon}_c$=0.0035, so confinement is required at the boundaries. For rectangular walls above the wall index value of 1.0% nearly all walls assure at least life safety (LS) performance criteria. It is proposed that in the design of dual systems where frames and walls are connected by link and transverse beams, the minimum value of wall index should be greater than 0.6%, in order to prevent excessive damage to wall members.

Management of Unilateral Facet Dislocation of the Cervical Spine

  • Baek, Geum-Seong;Lee, Woo-Jong;Koh, Eun-Jeong;Choi, Ha-Young;Eun, Jong-Pil
    • Journal of Korean Neurosurgical Society
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    • v.41 no.5
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    • pp.295-300
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    • 2007
  • Objective : Unilateral facet dislocation of the cervical spine occurs by flexion and rotation injuries and cannot be easily reduced by axial traction. We analyzed 14 consecutive patients with unilateral facet dislocation of the cervical spine to increase knowledge about anatomical reduction of locked facet and factors for successful reduction. Methods : Fourteen patients [10 men and 4 women] with unilateral facet dislocation of the cervical spine were retrospectively analyzed. Plain X-ray, computerized tomography scan, and magnetic resonance imaging were performed. All patients underwent manual reduction and surgery with anterior interbody fusion and plate fixation. The manual reduction was performed by neck flexion and rotation to the opposite side of dislocation, followed by rotation and flexion of the head toward the side of dislocation and extension with relaxation of traction. Mean follow-up period was 17 months. The level of spine, amount of subluxation, combined facet fracture, and time from injury to initial reduction were analyzed using the data obtained from medical records. Results : Thirteen [93%] patients were reduced successfully. Immediate reduction was achieved in 7 patients but failed in 7 patients. Seven patients underwent delayed closed reduction under general anesthesia, and successful reduction was achieved in 6 patients. Only one patient with bone chips between articular facets failed to achieve anatomical reduction. Conclusion : In order to reduce the locked facet more easily and safely, we recommend manipulative traction with anterior interbody fusion and plate fixation under general anesthesia after being aware of spinal cord injury with magnetic resonance imaging.

Site suitability for conifer plantation and a new challenge to utilize deciduous trees

  • NAGASHIMA, Keiko
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.24-24
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    • 2018
  • Degraded plantation forests are increasing because of unfavorable forestry conditions prevailing in Japan, including falling timber prices, increasing operational costs, and aging and declining forestry workforce. To remedy this situation, appropriate management strategy is required. This study introduces the challenges of Odai Town, Mie Prefecture that employed a new management strategy by evaluating site suitability for conifer forests and that proposes a new forest management regime of planting deciduous trees in unsuitable sites. The site suitability for conifer forests was evaluated from two aspects: the natural site conditions and the relationship among site conditions, growth, and damage by Anaglyptus subfasciatus Pic. in Cryptomeria japonica D. Don and Chamaecyparis obtusa Sieb. Et Zucc. forests. By analyzing the relationship among site conditions, growth, and insect damage based on field data obtained in plantation forests, growth evaluation and insect damage evaluation maps were developed. Based on the natural forest investigation, natural site condition maps for C. japonica and C. obtusa were established. Furthermore, by integrating these evaluation maps with the forest road maps showing the accessibility to the forest, the forest management regime for the whole plantation area of Odai Town was established. The forest management regime map indicates the sites suitable for forestry: suitable for long-rotation, short-rotation, and potential sites for short-rotation. The sites unsuitable for forestry were considered to be more suitable for broadleaved forests. Clear-cutting was conducted in a small area and different seral stage saplings (approximately 20 deciduous tree species) suitable to the site conditions were planted in an area of $80-120m^2$ protected by deer-fences. This might establish a forest composed of many species with a multilayer vertical forest structure in a short period. The planted saplings were distributed neither randomly nor uniformly to reflect the natural distribution of trees in the forest. A challenge to develop new products using the deciduous trees has started, such as wood chips for preparing smoked food, essential oil, and deodorizer. As these challenges have just begun, their effects on enhancing sustainable resource management are still being monitored. Even with the challenges, this regime can be of high value as a management strategy to remedy the situation of expansion of degraded forests in Japan.

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Problems of Working Hours and Shift Work Systems, and Propsed Methods for Their Improvement (근로시간 및 교대근무편성의 문제점과 개선방향)

  • Seo, Yu-Jin;;Park, Yeong-Man;Mun, Se-Geun
    • Journal of the Ergonomics Society of Korea
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    • v.22 no.3
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    • pp.13-26
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    • 2003
  • The purpose of this study is to investigate the present conditions of the night work and shift work systems in the heavy chemical industrial complexes found in Changwon, Masan, and Chinhae. Korea. We will attempt to define and classify their problems; and to discover further ways to improve their systems. Fifty production factories were carefully selected as the subjects for this study. The shift systems were classified into five categories. The consecutive night shifts were long in almost all cases with 6 days (36 factories) and 7 days (13 factories). It was found that the night work of about] 2 hours continues for a long period in the weekly rotation full-day shift systems and the night-including non-full-day shift systems, and there was no holiday during a shift cycle in the continuous full-day shift systems. The work time in most shift systems was longer than the 44-hours/week permitted by Korean law. Considering the characteristics of these various types of shift systems, the most essential thing to reduce the shift workers' work load may be to shorten their working hours and improve the schedule of shift systems. It is highly recommended as a fundamental solution. to reduce the portal-to-portal hours from 12 to 8 in the night-including non-full-day shift systems and the weekly rotation full-day shift systems, and at least to employ a 4-team 3-shift system in the continuous full-day shift systems. In addition to this, it should from now on be taken as a goal to restructure the types of shift systems by taking such measures as avoiding continuous night work if possible, providing sufficient off-duty intervals both before and after night shift, providing increased opportunities for workers to nap during night work. and increasing the number of holidays.

Effects of Active Release Technique and Lumbar Stabilization Exercise on Pelvic Asymmetry, Muscle Activation and Pain in Chronic Low Back Pain Patients (능동이완기법과 허리안정화 운동이 만성허리통증 환자의 골반비대칭, 근활성도 및 통증에 미치는 영향)

  • Nam, Seungmin
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.1
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    • pp.147-157
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    • 2020
  • Purpose : The purpose of this study was to investigate the effects of active release technique and lumbar stabilization exercise on pelvic asymmetry, muscle activation and pain in chronic low back pain patients. Methods : The subjects were 37 outpatients diagnosed with chronic low back pain. The patients were randomly divided into an active release technique therapy group (ART; n=18), and lumbar stabilization exercise group (LSE; n=19). These groups performed their respective therapy for a 30-minute session occurring two times a week over six-weeks period. To assess the patients' pelvic asymmetry, their pelvic tilt, and pelvic rotation was measured using X-ray imaging. EMG was used to evaluate the muscle activity of the lumbar muscle. The visual analogue scale (VAS) were used to measure the subjects' pain. Results : Both ART group, and LSE group exhibited statistically significant differences in their subjects' VAS and muscle activation of lumbar muscle after the therapy (p<.05). In ART group exhibited statistically significant decreases in their subjects' pelvic tilt and pelvic rotation after therapy (p<.05). There was a significant difference between the ART group, and LSE group (p<.05). Conclusion : The results of this study suggest that active release technique and lumbar stabilization exercise are effective in decrease pain and increase muscle activation in chronic low back pain patient. In addition active release technique is considered to be more effective in improving pelvic tilt and pelvic rotation than lumbar stabilization exercise.

The Effects of Green Tea Supplementation on Behavioral Changes, Striatal Dopamine Level, and Hepatic Antioxidant Parameters of Parkinson's Disease Model Rats

  • Kang, Min-Jeong;Lee, Sang-Sun
    • Nutritional Sciences
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    • v.9 no.2
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    • pp.61-67
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    • 2006
  • Green tea has attracted attention with respect to its potential for preventing and treating neurodegenerative disease. The neurotoxin, 6-hydroxydopamine (6-OHDA), was used to produce experimental Parkinson's disease (PD) model. The purpose of this study was to investigate the effects of green tea diet on behavioral changes, striatal dopamine content, and hepatic antioxidant parameters of PD model rats. In this study, we used male Sprague-Dawley rats weighing $200\sim220g$ and injected 6-OHDA into the right substantia nigra and medial forebrain bundle of the brain. The supply of green tea diet was started at 2 weeks before 6-OHDA lesion and continually supplied during 0, 2, and 4 weeks after 6-OHDA lesion (GT-0, GT-2, GT-4). Behavioral disturbance was measured by the stepping and d-amphetamine drug-induced rotation tests. Then, we assayed the striatal dopamine content and the hepatic malondialdehyde (MDA), hydrogen peroxide $(H_2O_2)$, and superoxide dismutase (SOD) activity. The percentage of lesioned forepaw to non-lesioned forepaw step scores was the highest in GT-4 group among all groups at both 3 and 4 weeks after 6-OHDA lesion. At 4 weeks after 6-OHDA lesion, the rotation score was the lowest in GT-2 group (p<0.05). However, increasing rate of the rotation score from 2 to 4 weeks after 6-OHDA lesion was the lowest in GT-4 group. The striatal dopamine content was not significantly different among four groups by green tea diet. The hepatic MDA level was the lowest in GT-4 group among four groups. The hepatic SOD activity was increased with the prolongation of green tea diet period These results suggest that green tea diet affects behavioral changes in rats of PD model. It seems that continuous green tea supplementation has an influence on the reduction of behavioral disturbance and the hepatic MDA level. Accordingly, continuous green tea supplementation was recommended for the prevention and treatment of PD. However, further studies are needed to investigate the mechanisms and efficacy of green tea in PD.

Torque Disturbance Analysis of Missile Hatch System by Spline Backlash (스플라인 백래시에 의한 유도탄 해치시스템의 토크 외란 분석)

  • Byun, Young Chul;Kang, E Sok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.1
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    • pp.89-99
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    • 2014
  • This paper presents the experimental torque disturbance analysis of a missile hatch system by spline backlash. The missile hatch system uses a spline and gear train for vertical elevation of the heavy hatch. The spline used for the rotation shaft of the hatch is generally used for automotive driving parts that transmit high amounts of power. It has an angular backlash, which results in jerks. Backlash of the hatch spline influences hatch swinging. The spline backlash and hatch swing are experimentally analyzed by measuring the hatch's rotation angle and acceleration. Hatch swing is visually observable for a short period, and it is measured by measuring the rotation angle variation and hatch acceleration. The shape of fluctuation and duration time of hatch angle variation are similar to those of torque. This shows that the hatch swing due to spline backlash generates torque disturbances.

Spin and 3D shape model of Mars-crossing asteroid (2078) Nanking

  • Kim, Dong-Heun;Choi, Jung-Yong;Kim, Myung-Jin;Lee, Hee-Jae;Moon, Hong-Kyu;Choi, Yong-Jun;Kim, Yonggi
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.80.1-80.1
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    • 2019
  • Photometric investigations of asteroids allow us to determine their rotation states and shape models (Apostolovska et al. 2014). Our main target, asteroid (2078) Nanking's perihelion distance (q) is 1.480 AU, which belongs to the Mars-crossing asteroid (1.3 < q < 1.66 AU). Mars-crossing asteroids are objects that cross the orbit of Mars and regarded as one of the primary sources of near-Earth asteroids due to the unstable nature of their orbits. We present the analysis of the spin parameters and 3D shape model of (2078) Nanking. We conducted Cousins_R-band time-series photometry of this asteroid from November 26, 2014 to January 17, 2015 at the Sobaeksan Optical Astronomy Observatory (SOAO) and for 25 nights from March to April 2016 using the Korea Microlensing Telescope Network (KMTNet) to reconstruct its physical model with our dense photometric datasets. Using the lightcurve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we determine the pole orientation and shape model of this object based on our lightcurves along with the archival data obtained from the literatures. We derived rotational period of 6.461 h, the preliminary ecliptic longitude (${\lambda}_p$) and latitude (${\beta}_p$) of its pole as ${\lambda}_p{\sim}8^{\circ}$ and ${\beta}_p{\sim}-52^{\circ}$ which indicates a retrograde rotation of the body. From the apparent W UMa-shaped lightcurve and its location in the rotation frequency-amplitude plot of Sheppard and Jewitt (2004), we suspect the contact binary nature of the body (Choi 2016).

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Glenohumeral versus subacromial steroid injections for impingement syndrome with mild stiffness: a randomized controlled trial

  • Yong-Tae Kim;Tae-Yeong Kim;Jun-Beom Lee;Jung-Taek Hwang
    • Clinics in Shoulder and Elbow
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    • v.26 no.4
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    • pp.390-396
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    • 2023
  • Background: The subacromial (SA) space is a commonly used injection site for treatment of impingement syndrome. For shoulder stiffness, glenohumeral (GH) injections are commonly performed. However, in cases of impingement syndrome with mild shoulder stiffness, the optimal site of steroid injection has yet to be identified. Methods: This prospective, randomized study compared the short-term outcomes of ultrasound-guided GH and SA steroid injections in patients who were diagnosed with impingement syndrome and mild stiffness. Each group comprised 24 patients who received either a GH or SA injection of 40 mg of triamcinolone. Range of motion and clinical scores were assessed before and 3, 7, and 13 weeks after the injection. Results: GH and SA injections significantly improved the range of motion and clinical scores after 13 weeks of follow-up. Notably, targeting the GH joint resulted in an earlier gain of forward elevation, external rotation, and internal rotation in 3 weeks (P<0.001, P=0.012, and P=0.002, respectively) and of internal rotation and a Constant-Murley score in 7 weeks (P<0.001 and P=0.046). Subsequent measurements were similar between the groups and showed a steady improvement in all ranges of motion and clinical scores. Conclusions: GH injections may be more favorable than SA injections for treatment of impingement syndrome with mild stiffness, especially in improving the range of motion in the early period. However, the procedures showed similar outcomes after 3 months. Level of evidence: I.

A study on the Factors of the patient satisfaction for nursing care in general hospital (종합병원 간호단위에서의 간호만족 영향요인 분석)

  • Kim, Kyeong-Sook
    • Journal of Korean Academy of Nursing Administration
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    • v.7 no.1
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    • pp.53-64
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    • 2001
  • The study was done to evaluate patient satisfaction with nursing care. The study subjects were patients admitted in a general hospital in Gangwon province. The instrument used in the study was developed by Lamonica. The reliability alpha of this tool 0.8596. The survey method was applied to collect data period of data collection was total 21days from September 4rd to September 24th in 2000. The data was analysed by statistical method of %, mean, ANOVA, Pearson's Correlation Coefficients though SPSS program. The follows are the summaries of results of the study. 1. The highest scores of satisfaction was shown in the area of technical professional nursing and the lowest scores was shown in area of nursing education. 2. The crossed analysis of patient general characteristics and satisfaction of nursing care showed a significance by marriaged status(p<0.05) but no significance by factors of sex, ages, education, religency. 3. Job satisfaction of nurses showed 2.79 in average on the basic of 5 marks. 4. The significant Correlation were found between job satisfaction degree and bed rotation rates , number of patients by one nurse, experience of nurse(p<0.05). 5. The significant Correlation were found between nursing satisfaction degree and ages, job satisfaction, bed rotation rates, number of patients by one nurse(p<0.05), experience of nurse(p<0.01). On basis of the above findings the following recommendations are made : to suggest to improve environment of nursing unit. And to suggest to improve job satisfaction for improvement of nursing satisfaction in practice.

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