• Publications of The Korean Astronomical Society
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• v.1 no.1
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• pp.13-20
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• 1984

New empirical relations between stellar CaII emission and rotation or age are derived by analyzing Wilson's CaII flux measurements (1968, 1978) of lower main sequence stars, and then we correlate them with their age and rotation rate. It is found that stellar chromospheric emission decays smoothly with age as a star slows down rotationally, establishing that both the emission level and rotation rate decrease with the square root of age.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.97-108
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• 1991

The purpose of this article is to know the standard figures of joint range of motion, in conjuction with age and sen, for normal adults. The results of assessment and analysis io shoulder and hip joint range of motion are as follows : 1) The average shoulder joint range of motion in normal adults are $160.5^{\circ}$ in flexion, $53.5^{\circ}$ in extension, $159.3^{\circ}$ in adduction, $62.3^{\circ}$ in internal rotation, $83.9^{\circ}$ in external rotation, The average hip joint range of motions are $116.8^{\circ}$ in flexion, $16.1^{\circ}$ in extension, $41.1^{\circ}$ in abduction, $33.8^{\circ}$ in abduction, $40.0^{\circ}$ in interne rotation, $41.2^{\circ}$ in external rotation. 2) There is no significant difference in shoulder and hip joint range of motion between male and female (p>0.05). 3) As to the inter-relation in age and range of motion, the left flexion and extension, internal rotation and right extension in shoulder joint is decreased gradually with increasing age, and left flexion (knee flexion, knee extension) and right flexion (knee extension) in hip joint is decreased with increasing age (p<0.01). 4) Relating to age and sex, the twenties male shows highest range of motion in shoulder and hip joint, with .the fifties female shows, lowest range of motion.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.951-957
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• 2010

The purpose of this study is to identify the types and features of job rotation being operated in a motor company. The types of job rotation have been classified according to the range of rotation and its cycle. Also, the features of the favorable rotation types were examined by the worker's age and their types of tasks. The results show that workers prefer broader ranges and slower cycles of rotations as they age. Moreover, older workers tend to show an increase in the preference of participating in job rotations. The result of this study is expected to be applied as fundamental data to job design.

• The Journal of Internal Korean Medicine
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• v.21 no.1
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• pp.135-145
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• 2000

Objective : This study has been made to analysis of clinical type of vertigo prodromic Cerebral Vascular Disease in stroke patients who admitted to sangji oriental hospital department of circulatoty internal medicine in the period from July. 1999 to October 1999. Methods : A Questionaire was done after explanationin details to patients and agreement of patients. The inquire was done as follows. Sex and age, risk factor of stroke, type of stroke, existence of vertigo last three years before stroke attack, the beginning age of vertigo and period of prevalence, frequency, continuance time of vertigo, predilection season and time, factor of causing vertigo, accompanying symptoms of vertigo, severity of vertigo. Result and Conclusion : The existence of Rotation sense(Rotation group and non-Rotation group) and the type of Stroke is no difference significantly but the Rotation vertigo group and non-Rotation vertigo group is difference significantly in distribution. The sixties in age of vertigo attack, previous vertigo before 3 year Stroke attack, irregular in predilection season of vertigo, have a high frequency significantly in distribution and previous period of vertigo has no significantly difference in distribution. One or two per a month in frequency of vertigo, below 5 minute in continuance time of vertigo, irregular in predilection time of vertigo, stand up and sit down in causing vertigo position have a high frequency significantly in distribution.

• Journal of Forest and Environmental Science
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• v.24 no.3
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• pp.143-149
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• 2008

We conduct economic analysis of the snow damage on sugi (Cryptomeria japonica) forest stands in Toyama Prefecture, Japan. We utilize a single tree and distant independent growth simulator called "Silv-Forest." With this growth simulator, we developed an optimization model by dynamic programming, called DP-Silv (Dynamic Programming Silv-Forest). The MS-PATH (multiple stage projection alternative technique) algorithm was embedded as a searching algorithm of dynamic programming. The height / DBH ratio was used to constrain the thinning regime for snow damage protection. The optimal rotation age turned out to be 65 years for the non-restricted case, while it was 50 years for the restricted case. The difference in NPV of these two cases as the induced costs ranged from 179,867 to 1,910,713yen/ha over the rotation age of 20 to 75 years. Under the optimal rotation of 65 years, the cost became 914,226 yen/ha. The estimated annual payment based on the difference in NPV, was from 9,869 yen/ha/yr to 85,900 yen/ha/yr. All in all, 10,000 yen/ha/yr to 20,000 yen/ha/yr seems to cover the payment from the rotation age of 35 to 75 years.

• Human Ecology Research
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• v.55 no.2
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• pp.125-140
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• 2017

This study composed spatial cognition tasks within the system of geometric area to study children's spatial cognition development systematically. It surveyed children's execution of direction, rotation, symmetry, conjugation, and part/whole cognition tasks. A spatial geometry cognition task set (consisting of total 27 sub-tasks) was presented to 60 children (20 each in groups of 3-, 4-, and 5-year-old) in order to confirm how children's execution of spatial geometry cognition changed depending on children's age and sex as well as if the execution of the spatial geometry cognition showed a difference after each task area. As a result, the execution of the whole direction task and the part/whole task gradually increased between age 3 and age 5. The execution of the whole rotation task, whole symmetry task, and whole conjugation task rapidly increased between age 3 and age 4. Significant sexual difference did not appear in the execution of spatial geometry cognition tasks. The execution of the conjugation and part/whole task was high in each task area, and the execution of the direction, rotation, and symmetry task was relatively low. In addition, the difference of task execution appeared in the sub-tasks of direction, symmetry, and conjugation areas. This result suggests the theoretical discussion possibility of children's spatial geometry cognition development. In addition, the empirical results of this study can be applied to child education plans and activity compositions appropriate for child development.

• The Journal of Korean Physical Therapy
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• v.7 no.1
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• pp.21-31
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• 1995

This study was described the movement patterns when rising from supine to erect stance. Two hundred eighty seven subjects, ranging in age from 6 year to 28 were filmed while rising from a supine position. Movement Patterns were classified using categorical descriptions of the action of three body regions-the upper and lower extremity, head-trunk region. This study was designed to determine whether within the rising task the movement patterns of different regions of the body vary with age level and sex. The incidence of each movement pattern was calculated and graphed with respect to age level and sex. The most common form of rising for subject in the 6, 7 year mate group usually involved push and reach pattern with upper extremity, half kneel pattern with lower extremity, partial rotation pattern with head-trunk. In the 6, 7 year female group usually involved symmetrical push pattern with upper extremity, symmetrical squat with balance step pattern with lower extremity, symmetrical interrupted by rotation pattern with head - trunk. In the teenage and twenties both sex group usually involved symmetrical push pattern with upper extremity, symmetrical squat pattern with lower extremity, partial rotation pattern with head-trunk.

• Journal of Korean Academy of Nursing Administration
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• v.10 no.4
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• pp.459-472
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• 2004

This study was designed to investigate perception of job rotation and an organizational commitment of staff nurses working at K hospital and find the way of increasing an organizational commitment for the groundwork for efficient changes in the nursing staff. Data were collected from Aug. 20 to Aug. 28, 2004 through self reporting questionnaires taken by 318 nurses working at a hospital. The three structured instruments were used for collecting the data; Questionnaires for measuring the perception of job rotation, Questionnaires for measuring the utility and the problem of job rotation, and Mowday's Organizational Commitment Questionnaires. The Results were as follows : 1. 66.0% of 318 staff nurses approved of regular job rotation; 34.0% of them disapproved 34.3% of them wanted to get transferred to another department; 65.7% of them didn't. 2. Of general characteristics, age(F=17.469, P=.000), marital status(F=-2.781, P=.006), religion(F=5.688, P=.001), education level(F=8.816, P=.000), position(F=15.591, P=.000), a total clinical career(F=11.606 p=.000) and field in practice(F=4.206, P=.000) were significantly related to an organizational commitment. 3. There is relatively positive correlation between the perception of job rotation and an organizational commitment. In conclusion, the utility of on the job rotation and organizational commitment showed the positive correlation.

• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.166-174
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• 2014

Background: Our study was to determine the effect on shoulder isokinetic muscle strength and muscle endurance in isolated full-thickness supraspinatus tendon tear and combined other rotator cuff tear. Methods: Total of 81 male patients (mean age $57.8{\pm}7.4$ years) who were diagnosed as a full-thickness supraspinatus tendon tear were included. They were classified into isolated or combined tear. The isokinetic muscle strength and muscle endurance were measured using the Biodex multi-joint system $PRO^{(R)}$ (Biodex Medical Systems, Shirley, NY, USA) in following movements: shoulder abduction, adduction, flexion, extension, external rotation, and internal rotation. Then, the difference in muscle function according to the type of tears were assessed. Fifty-seven patients had isolated supraspinatus tendon (mean age $56.9{\pm}7.3$ years). They were classified into either anteroposterior tear or modified mediolateral tear. The size were measured using T2-weighted magnetic resonance imaging scans in sagittal plane. Results: Between subjects categorized into the type of tear, we found significant inter-categorical differences in isokinetic muscle strength during abduction, adduction, flexion, extension, and internal rotation, and in muscle endurance during flexion, extension, and internal rotation. Anteroposterior diameter tear, we did not show significant differences in either isokinetic muscle strength or muscle endurance during any movements. However, with modified mediolateral diameter, we found significant differences with isokinetic muscle strength during adduction, and in muscle endurance the external rotation and internal rotation. Conclusions: We found that a supraspinatus tendon tear associated with more numbers of rotator cuff tears has lower isokinetic muscle strength and muscle endurance than a tear found alone.

• The Journal of Korean Physical Therapy
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• v.22 no.1
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• pp.27-32
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• 2010

Purpose: This study was designed to examine the effects of a Halliwick rotation program on improving balance. Methods: Nine healthy females were randomly assigned to a Halliwick rotation program training as an aquatic group (n=9, age=$22.5{\pm}1.3$ years) or to a control group. The aquatic group trained using a Halliwick rotation program (3 times/week, 30 min/day) for 6 weeks. Balance was measured according to stance position: Hard Plate Open Eyes (HOE), Hard Plate Close Eyes (HCE), Soft Plate Open Eyes (SOE) and Soft Plate Close Eyes (SCE). This was done before the training and 3 and 6 weeks after the training. The data were analyzed with the SPSS Win 12.0 program using repeated measure ANOVA. Results: There were significant training-induced differences in SOE and POE (p<0.05), and in SCE and PCE (p<0.05) by Toe pad. There were significant training-induced differences in SOE and POE (p<0.05) by Heel pad after the aquatic rotation exercise program. Conclusion: The Halliwick rotation program can improve balance.