• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.235-241
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• 2018

This study was conducted to find out the growth pattern of Pinus koraiensis plantation over 34 years, focusing on DBH, height, basal area and allometric change. Total increment (TI), mean annual increment (MAI) and correlation coefficient were calculated and compared with stand and dominants. Total increment and mean annual increment of both DBH and height of dominants were bigger than those of stand. The difference was apparently shown bigger in DBH than height. Unlike DBH and height the total increment and mean annual increment of basal area per hectare of dominants were distinctively smaller than those of stand. Furthermore MAI of dominant was increasing until age 42, while MAI of stand increased at early ages and then gradually decreased after culmination like MAIs of DBH and height. MAIs of basal area of dead trees at each measurement tended to increase until early age (18 years in this study), while it reached a peak and gradually decrease after that (21 years in this study). Correlation coefficient between DBH and height tended to decrease as both dominant and stand age and the difference between dominant and stand was not clearly shown over the measurement period. Correlation coefficients between DBH and crown width tended to decrease as the trees age and correlation coefficients of dominant were clearly shown smaller than that of stand. Correlation coefficients of height and crown width also was found to be similar to correlation coefficients between DBH and crown. Meanwhile correlation coefficient of height and crown width dropped more radically than coefficient of DBH and crown width as the trees age.

• Journal of Forest and Environmental Science
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• v.30 no.3
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• pp.259-266
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• 2014

Stand Density Diagrams (SDD) are average stand-level models which graphically illustrate the relationship between yield, density and mortality throughout the various stages of forest development. These are useful tools for designing, displaying and evaluating alternative density regimes in even-aged forest ecosystems to achieve a desired future condition. This contribution presents an example of a SDD that has been constructed for teak forests of Karnataka in southern India. The relationship between stand density, dominant height, quadratic mean diameter, relative spacing and stand volume is represented in one graph. The relative spacing index was used to characterize the population density. Two equations were fitted simultaneously to the data collected from 27 sample plots measured annually for three years: one relates quadratic mean diameter with stand density and dominant height while the other relates total stand volume with quadratic mean diameter, stand density and dominant height.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.414-421
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• 2000

This study was carried out for the artificial forest stand of 23 years old jack pine(Pinus banksiana Lamb.) in Soheul-myun, Pochun-kun, Kyunggi province of Korea. The objectives of this study were to investigate the stand volume increment and the rate of stand volume, and were to investigate present stand volume to determine annual cutting volume for keeping stand volume to an ideal level for investigated jack pine stand. For a reasonable calculation of stand volume increment, diameter of breast height(DBH), tree height, bark width, and core length for the last 10 years for respective sampling plots were measured. By using these measurements annual diameter increment in DBH class, stand volume increment of 95% confidence interval and tree height curve equation were calculated. The tree height value was derived from the tree height curve equation. Calculation of tree volume by using the tree volume table was made by conferring the tree height value. The summarized results for investigated jack pine trees were having 7.7% annual stand volume increment with 6.1% estimated error. The total stand volume per ha was $79.58m^3$, accordingly the annual stand volume increment was $6.13m^3$ per ha, and the 95% confidence intervals range from 5.77 to $6.51m^3$.

• PNF and Movement
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• v.9 no.1
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• pp.31-38
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• 2011

Purpose : Sit-to-stand (STS) is one of the important activities of daily living (ADL) and each of its parameters is used frequently. This study aimed to examine the influence of different seat height on performance time and floor reaction force strength during an STS movement. Methods : Fifteen young-adult male subjects participated in this study. The subjects were divided into three groups based on lower leg length. Subjects performed an STS movement twice from chairs at height adjusted by the lower leg length of each subject. To examine the influence of the chair seat height, ground reaction forces during a STS performed with 3 chair heights adjusted to each subjects lower leg length were compared. Results : Vertical ground reaction force and time during an STS movement were measured to evaluate. Parameters regarding ground reaction force were selected for analyses. Significant differences were found in ground reaction force at G1 was greater than G2 and G3. Conclusion : The STS movement achievement strategy differed since chair seat height changes relatively by the difference in lower leg length. When conducting the ability to achieve STS movement rating test, chair seat height considering each subject's lower leg length may be needed.

• Journal of Plant Biology
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• v.15 no.4
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• pp.1-12
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• 1972

To study on the annual height growth of Pinus densiflora within natural pine stands in central Korea, twenty two pure closed Pinus densiflora stands were selected subjectively in the west-central region of Korea. In each stand twenty trees were chosen randomly. For each tree, abotu ten to fifteen measurements of internodal lengths were made from leader top to trunk base. A total of one hundred thirty four soil samples was collected. Each soil sample was bulked with three subsamples. The ranges of the growth measurements per stand, per tree and per observation were 14.9-35.4cm, 9.0cm-54.4cm and 2.4cm-69.0cm respectively. The total mean value was 23.5cm. The Student-Newman-Keul's tests for the multiple comparison among the mean values of the height growth per stand were very highly significant. The resutls of the analysis of variance of the height growth data for the selected fifteen stands among the twenty two stands indicate that sampling efficiency might be increased to 744% if measurement of the growth were made on fifteen trees per stand from twenty stands instead of twenty trees per stand from fifteen stands. The annual height growths of Pinus densiflora and Pinus koraiensis for the period from 1960 to 1968 were 21.74$\pm$5.29cm (10) and 20.56$\pm$5.59cm (10) respectively. The total means of easily-soluble phosphorus, total nitrogen, loss on ignition and pH for the soil samples were 2.8 ppm, 0.09%, 5.4% and 4.7 respectively. The ranges of those amounts were 18.7-1.7ppm, 0.17-0.05%, 11.6%-3.1%, 3.9-5.1 respectively. The relationship of the annual height growth of P. densiflora to soil was studied in terms of standard partial multiple regression. Among soil properties such as non-capillary pore space, capillary pore space, maximum field capacity, loss on ignition, soil reaction, total nitrogen and easily-soluble phosphoros investigated, the easily soluble phosphorus in one analysis and loss on ignition and soil reaction in the other analysis seem to have significant positive influence on the annual height growth.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.169-185
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• 2016

Recently mean stand height has been added as new attribute to forest type maps, but it is often too costly and time consuming to manually measure 9,100,000 points from countrywide stereo aerial photos. In addition, tree heights are frequently measured around tombs and forest edges, which are poor representations of the interior tree stand. This work proposes an estimation of mean stand height using an image-based point cloud, which was extracted from stereo aerial photo with FUSION S/W. Then, a digital terrain model was created by filtering the DSM point cloud and subtracting the DTM from DSM, resulting in nDSM, which represents object heights (buildings, trees, etc.). The RMSE was calculated to compare differences in tree heights between those observed and extracted from the nDSM. The resulting RMSE of average total plot height was 0.96 m. Individual tree heights of the whole study site area were extracted using the USDA Forest Service's FUSION S/W. Finally, mean stand height was produced by averaging individual tree heights in a stand polygon of the forest type map. In order to automate the mean stand height extraction using photogrammetric methods, a module was developed as an ArcGIS add-in toolbox.

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.15-19
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• 1983

To establish the stand volume table of Pinus koraiensis S. et Z. and Larix leptolepsis Gord. mean diameter at breast height (D), mean height, basal area per ha, stand from height (H.F), basal area height, number of trees per ha, volume per ha, stand age and site were investigated for 107 plots of P. koraiensis and 82 plots of L. leptolepsis throughout the country. The obtained results are as follows; 1) the relationships between stand volume (V) and H.F. were log V=1.3855+0.1168 H.F and log V+0.9929+0.1543 H.F in P. koraiensis and L. leptolepsis, respectively. 2) The relationship between D and H.F was estimated as H.F = 1.2569+0.2576D for P. koraiensis and as H.F = 4.3045+0.1443D for L. leptolepsis 3) Estimated errors calculated with the application of these stand volume tables were 18.29% and 19.22%r for P. koraiensis and L. leptolepsis respectively.

• Tribology and Lubricants
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• v.19 no.2
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• pp.102-108
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• 2003

The height of laser bumps has been considered as the limit of the minimum flying height in the contact start-stop (CSS) of hard disk drives. In this paper, tribological interactions at flying height under laser bumps are investigated in a spin stand for development of ultra-low flying head-disk interface. With the reduction of the spinning speed in a spin stand, the flying height is decreased under the height of laser bumps and, then, head-disk interactions are investigated using AE and stiction/friction signals. During seek tests and 20000 cycle-sweep tests, AE and stiction/friction signals are not significantly changed and there are no catastrophic failures of head-disk interface. Bearing analysis and AFM analysis show that there are signs of wear and plastic deformation on the disks. It is suggested that flying height could be as low as and, sometimes, lower than laser bump height.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.446-453
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• 1999

In this study, the effects of stand planting density on parameters of stand height and basal area growth models were investigated. We used the Korf equation as the base model in estimating the parameters of the growth models for cryptomeria plantation forest stands. Then, in order to investigate the effects of the change in plantation density on the parameter estimates, the "extra sums of square" principle, which provided a reasonable statistical procedure for a performance test, was used. The results of the test coincide with the understandings that stand height growth is not affected significantly by the planting density and the growth curves of stand basal area approaches a common asymptote regardless of the stand density for a given site. However, the shapes of the basal area growth curves were affected significantly by the planting density. Based on the results of the test, we developed a basal area growth model to account for the effects of initial planting density in cryptomeria plantation forest stands.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.107-112
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• 2015

PURPOSE: This study investigated the effects of lower limb and trunk muscles activation on seat angle and height during sit to stand and stand to sit. METHODS: Subjects were instructed to sit and stand on different angles and heights; $0^{\circ}$(43cm), $5^{\circ}$(48cm), $10^{\circ}$(51cm) and $15^{\circ}$(58cm). Measurements were conducted from sit to stand and stand to sit for external oblique, transversus abdominis, rectus femoris, vastus medialis, vastus lateralis, tibialis anterior and gastrocnemius muscle activation by surface EMG. The muscle activation was measured three times for five seconds in each posture, and the %RVC value was calculated after the exclusion of one second before and after this measurement. This calculation standardized the data from each participant so it could be comparatively analyzed. RESULTS: The external oblique, tibialis anterior, and erector spinae muscles showed significant difference in $10^{\circ}$(51cm), $15^{\circ}$(58cm) and $0^{\circ}$(43cm), rectus femoris, in $15^{\circ}$(58cm) and $0^{\circ}$(43cm)(p<.05) during sit to stand. The external oblique, tibialis anterior, and rectus femoris muscles showed significant difference in $0^{\circ}$(43cm) and $15^{\circ}$(58cm), erector spinae and vastus medialis muscles showed significant difference in $10^{\circ}$(51cm), $15^{\circ}$(58cm) and $0^{\circ}$(43cm)(P<.05) during stand to sit. CONCLUSION: The present study findings indicate that the toilet seat angle and height could affect muscle activities of the lower limb and trunk.