• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.91-99
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• 2019

PURPOSE: This study was conducted to evaluate the activity of trunk muscles according to width of the foot and posture of the arm during sit to stand (STS). METHODS: Thirty subjects were recruited and examined for variation in muscle activity of the erector spine, gluteus maximus, gluteus medius and external oblique during different STS conditions; namely, the cross arm basic sit to stand (CBSTS), overhead basic sit to stand (OBSTS), cross arm wide sit to stand (CWSTS), and overhead wide sit to stand (OWSTS). Repeated measures ANOVA (Analysis of Variance) was used for analysis. RESULTS: Erector spinae muscle activity showed a significant increase in the OBSTS condition (p<.05) and external oblique muscle activity showed a significant increase in the OWSTS condition ((p<.05). There was no significant difference in the activity of the gluteus maximus and gluteus medius under any conditions (p>.05). CONCLUSION: During evaluation of the performance of the STS, the CWSTS condition will be useful to decrease the muscle activity of the erector spinae and the OWSTS condition will be useful to increase the muscle activity of the external oblique. The results of this study can be used as an index to find a suitable exercise method for subjects who have back pain or to strengthen the abdomen.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.591-597
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• 2022

Objective: The sitting and standing are motions that correspond to the previous stage of rehabilitation to go to walking for daily life. The purpose of this study was to measure task times, path length of the center of pressure (COP) and activity on the vastus femoris muscle using surface electromyography (EMG) when standing up and sitting down. Design: One group cross-sectional design Methods: Fifteen elderly subjects (8 male, 7 female) participated. All subjects were tested three times according to four assist levels (non-assist, lower, middle, and maximal assist) using adjusts the length of spring at sit-to-stand and stand to sit on a chair. The task duration, and COP path length were recorded for the balance function on the Nintendo Wii fit board. The activity of the rectus femoris muscle was recorded on both legs using surface EMG. Results: The results showed that the task duration of the sit-to-stand and stand-to-sit were significantly increased compared to without assist (p<.05). The activation of the rectus femoris muscle more significantly decreased compared to without assistance at standing or sitting (p<.05). Conclusions: The assistive chair showed less quadriceps muscle activation during sitting and standing compared to without assistance. We suggest that our assist-standing chair can help with activities of daily living such as standing up and sitting down movements adjusting the spring length for control assist level by safely.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.502-516
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• 1995

The objective of this study was to estimate throughfall, stemflow, interception loss and net rainfall in relation to rainfall interception, and to understand the factors affecting interception process at Pinus taeda stand and Pinus densiflora stand in the Research Forests of Seoul National University, located in Choosan, Kwangyang, Chollanamdo. 1. The gross rainfall during the period of field observation was 3,107.6mm(average 1,035.9mm/year). Most of the daily rainfall intensity was under 30mm, which was 90% in 1992, 81% in 1993 and 88% in 1994. 2. In this study the throughfall, stemflow, interception loss and net rainfall were expressed separately as a function of gross rainfall. The overall throughfall collected during the period of field observation was 2,432.5mm(78.3%) at Pinus taeda stand and 2,699.6mm at Pinus densiflora stand, out of total rainfall of 3107.6mm. The canopy storage capacity, which was determined by the prediction equation between gross rainfall and throughfall was 1.1mm at Pinus taeda stand and 1.3mm at Pinus densiflora stand. 3. The sums of stemflow from measurement of total rainfall at Pinus taeda stand and Pinus densiflora stand was 227.3mm(7.3%) and 62.7mm(2.0%), respectively. The minimum rainfall causing stemflow was estimated as 7.2mm at Pinus taeda stand and 1.9mm at Pinus densiflora stand. 4. Interception loss accounted for 447.8mm(14.4%) at Pinus taeda stand and 345.3mm(11.1%) at Pinus densiflorra stand. 5. Net rainfall was 2,659.8mm(85.6%) at Pinus taeda stand and 2,762.3mm(88.9%) at Pinus densiflora stand. 6. The rates of throughfall and stemflow increased with increasing the gross rainfall. However, the amounts of throughfall and the stemflow were constant above 30mm at Pinus taeda stand and 50mm at Pinus densiflora stand. The rates of interception loss decreased with increasing the gross rainfall. However, the amount of interception loss was constant above 50mm at Pinus taeda stand and Pinus densiflora stand.

• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.331-337
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• 1988

To investigate the effects of forest stand and stony characteristics on interception loss from canopy trees, throughfall and stemflow under the canopy of a pine stand and a hardwood stand were measured during 4-month periods July to October, 1986 at the Kwanak Arboretum near Anyang, and the data were analysed by correlation and regression methods. The man results obtained from this study are summerized as follows : 1. The overall throughfall collected during measurement period were 593.5mm(76.7%) in the pine stand and 663.1mm(81.8%) in the hardwood stand oui of total percipitation of 773.8mm. Combined regression analysis describes the relation between total precipitation(P) and throughfall(T) in the pine stand as T=-1.8675+0.8320 P. in the hardwood stand as T=-8179+0.8805P. 2. And the sum of stemflow from measurement of total precipitation in the pine stand and the hardwood stand were 37.4mm(4.8%) and 15.5mm(2%), respectively. In total precipitation less than 2.5mm, stemflow were not measured in both the pine stand and the hardwood stand. Regression equations for the pine stand and the hardwood stand are S=-0.6155+0.0698P, S=-0.0497+0.0183P. The mean slope and intercept of the individual regression of stemflow on rainfall for each fewest stand indicate the proportion of the rain diverted to the trunks and trunk water capacity, respectively. 3. Interception loss accounted for 142.9mm(18.5%) in the pine stand and 125.2mm(16.2%), in the hardwood stand. 4. By quadratic predictive model of relation between interception loss and total incident rainfall, the extent of variance in interception loss explained was about 72% and 61% in the pine stand and the hardwood stand respectively.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.160-166
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• 1996

Objective of this study was to investigate the effects of all current speed on the microclimates above and inside the plug stand under artificial light. Maximum air temperature appeared near the top of the plug stand. Difference in air temperature inside the plug stand increased with the decreasing air current speed. Difference in relative humidity(DRH) to the relative humidity at the Inlet of the main air flow conditioner Inside and above the plug stand decreased with the increasing air current speed. Relative humidity inside the plug stand was 10-15% higher than that above the plug stand. DRH inside a stand of plug at air current speed of 0.3m s$^{-1}$ was about two times as many as that at air current speed of 0.9 m s$^{-1}$ . DRH inside the plug stand was 2.8-6.5% higher at LAI of 2.6 than that at LAI of 0.5. Gradient for the vapour pressure deficit was distinctly appeared at the low air current speed. Direction of vapour pressure flux is from the medium surface upwards. Difference in vapour pressure(DVPD) to the vapour pressure deficit at the inlet of the main air flow conditioner inside and above the plug stand decreased with the increasing height above the medium surface. DVPD inside the plug stand was 0.3-0.4㎪ higher at air current speed of 0.9m s$^{-1}$ than that at air current speed of 0.3m s$^{-1}$ . Results for the effects of air current speed on the relative humidity and vapour pressure deficit indicated that the microclimates above and inside the plug stand at the rear region in plug trays were slightly unfavorable compared to those at middle region.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.186-192
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• 1988

This study was carried out to estimate the stand form factor that is necessary to estimate stand volume by STRAND method among plotless sampling methods. The data measured for this study were based on the 380 sample plots from Larix leptolepis and 358 sample plots from Pinus koraiensis which were distributed in the region of Kyeongi, Kangweon, Chungbuk, Chungnam, Chun-buk and Kyeongbuk. 1. Stand form factor was highly correlated with in the following order, stand form height, stand average height, average diameter, stand age, distance of stem, and basal area height. 2. The best fitted equation of stand form factor of above two tree species were presented in table 3. 3. Stand form factor tables using estimated equations on the table 3 were prepared and presented in table 4, 5(Larix leptolepis), 6, 7(Pinus karaiensis). 4. The relatioinships between estimated value and actual value were Y=bx, where b approached nearly 1.0, and there were not any significant differences between them. 5. The percentages of estimated error on stand form factor table were ranged from 2.39% to 4.15% in Larix leptolepis and from 1.73% to 2.50% in Pinus koraiensis. Therefore, the stand form factor could be exactly estimated by use of these tables.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.253-255
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• 1999

We measured stand-by power of electrical machinery and appliance which are used at office and house. And we estimated potential electrical energy saving through stand-by power and the expecting number of supplied apparatus. As a result, We can reduce electrical energy by minimizing a stand-by power consumption up to three billion kWh which are equal to about 1/3 of an atomic power plant's generating power of 1 year.

• Korean System Dynamics Review
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• v.1 no.1
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• pp.81-102
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• 2000

After the crisis of foreign troubles, various researchers are analyzing the causes of IMF stand-by arrangement in their own ways. But, most research have been lacking in covering the overall aspects of the causes which IMF stand-by arrangement results from. This paper extracts the reasons of IMF stand-by arrangement using Mind Mapping methods and intends to draw up cause ＆ effect map.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.127-134
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• 1999

This study was performed to obtain the basic data to present rational silvicultural tending plan. It makes these widely distributed pine-oak mixed stand and each of pure stand in middle province on object of this study and do comparative analysis of light condition about stand parameter and natural regeneration according to each slope(north, west and south) conditions of location in central part of South Korea. Sample plots for pine-oak mixed stand and pine and oak pure stand were established on each of southern, northern and western slopes based upon site and growth conditions of the slope. Sample plot was a circle of 0.05ha with a diameter of 25.24 m. A sample plot has between 30 and 40 tree in it. Total 23 sample plots were established; 9 pure pine stands, 8 pine-oak mixed stands. and 6 pure oak stands across lower, middle, upper parts of slopes. Relative light intensity within a stand was' measured by crown- photo(fish-eye lens; 180$^{\circ}$) system through fish-eye lens and by comparing each plot with the denuded through PAR-sensor. The crown closure ratio of pure pine stand (75%) shows much lower than that of mixed stand (90.9%) and pure oak stand (93%). The relative light intensity within a stand showed an opposite result. The crown closure of mixed stands tended to become gradually low as the slope moves from the north to the south, but the relative light Intensity within the stand tended to rise. By analyzing the relationship between the relative light intensity within a stand and stand parameter, light intensity within a stand tended to decrease as the diameter and N/ha increase. Number of oak seedlings and light intensity within a stand is in a straight-line regression relation. In particular, the number of oak seedlings was the highest in mixed stands on the southern slope. But no single pine seedling was found. The unfavorable conditions of l0cm thick litter layer and low relative light intensity in a stand (ranging between 4% and 8%) is considered to prevent pine seeds from germinating.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.146-155
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• 1992

The natural mixed stand in Jindong-Ri, according to a recent study, showed the possibility of selection cutting as a silvicultural system based on the stand structure such as DBH distribution and height distribution. However, volume structure per DBH class of this stand had not a mature stand of selection cutting. In this study, wherefore, the rate of increment for DBH and volume was used to predict the future stand structure including volume distribution per DBH class. The possibility of selection cutting was then discussed using the future stand structure. From the prediction of future stand structure for 30 years per every 10 years, it could be concluded that the stand will be induced to selection cutting forest because of enough number of trees in objective DBH class and above, total volume per hectare, and the volume of large DBH class which can be harvested every year. However, this stand still did not show the structure of typical selection cutting which has the rate of 1 : 2 : 7 in the number of trees per hectare and the volume rate of 5 : 3 : 2 for large, medium, and small DBH class. This problem could be improved by appropriate silvicultural treatments.