• Journal of Ocean Engineering and Technology
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• v.17 no.5 s.54
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• pp.25-31
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• 2003

Numerical experiments have been conducted using the nonlinear combined refraction-diffraction model, in order to analyze the generation characteristics of stem wave, which is formed by the interaction between vertical structure and the oblique incident waves. The results of stem wave are discussed through the stem wave height distribution along/normal vertical structure, under the wide range of incident wave conditions-wave heights, periods, depths, and angles. Under the same wave height and period, the larger the incident wave angle, the higher the stem wave heights. According to the results of wave height distribution, in front of vertical structure, the maximum of stern wave heights occurs in the location bordering the vertical wall. Furthermore, the most significant result is that stem waves occur under the incident angles between $0^{\circ}\;and\;30^{\circ}$, and the stem wave height ratio has the maximum value, which is approximately 1.85 times the incident wave height when the incident wave angle becomes $23^{\circ}$.

• Journal of Life Science
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• v.8 no.4
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• pp.431-436
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• 1998

These studies were carried out to obtain useful information about the effective selection of vegetable perilla by estimating the genetic relationships between the heritabilities and the genetic correlations of quantitative traits among eight agronomic characters from 91 perilla varieties. The positive correlations were showed among characters such as between leaf weight and leaf size, leaf weight and leaf length, leaf weight and leaf width, leaf weight and plant height, leaf weight and stem diameter, leaf size and leaf length, leaf size and leaf width, leaf size and plant height, leaf size and stem diameter , leaf length and leaf width, leaf length and plant height, leaf length and stem diameter, leaf width and plant height, leaf width and stem diameter, plant height and stem diameter, plant height and the number of internodes per plant, and the number of internodes per plant and the number of leaves per plant. Heritabilities were high as from 0.7311 to 0.9112 among leaf weight, leaf size, leaf length, leaf width, plant height, stem diameter, and the number of internodes per plant.

• Journal of Forest and Environmental Science
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• v.31 no.1
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• pp.47-54
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• 2015

The study was performed to analyze the growth of the red pine (Pinus densiflora) in the Eastern Region of Korea. Stem profile data from a total of 8 dominant trees of which each tree represents its site were collected and used for the analysis. The stem volumes were calculated using Smalian's formula and much higher than the ones by Korea Forest Research Institute in larger than dbh 40 cm. The total bark volumes were more proportionally related to dbh and stem volume than to height and age. The bark thickness and volume decreased as relative height increases but increased as relative dbh increased. The average PAI of dbh and height reached the highest at 0.8 cm/yr (age 15) and at 0.45 m/yr (age 30) respectively, while the average PAI of volume steadily tended to increase up to age 80. The growth percentages of dbh, height and volume tended to decrease with age and volume growth percentage was higher than dbh and height.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.12
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• pp.1718-1723
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• 2017

Objective: The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. Methods: The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. Results: The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Conclusion: Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.6-10
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• 1997

Ninety-four collections of domestic ginger were evaluated for plant hight, leaf number, stem number, leaf length and width, rhizome yield per plant revealed good variability in stem number and rhizome yield per plant. Moderate variation was observed in plant hight, leaf number, leaf length, leaf width and stem diameter. Rhizome yield per plant was positively correlated with six characters, and leaf number, plant height and stem diameter were positive significant correlation with rhizome yield per plant. Path coefficient analysis indicated that stem number, followed by leaf number, stem diameter, had maximum direct effects on rhizome yield per plant. Maximum indirect effect was observed in case of plant height through leaf number. The indirect effects of leaf length and leaf width through leaf number, and plant height, leaf length and leaf width through stem diameter were also observed. From the selection point of view, the characters like plant height, stem number and leaf number per clump may be considered suitable in choosing a good genotype.

• Korean Journal of Plant Resources
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• v.1 no.1
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• pp.1-7
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• 1988

This experiment were carried out to study the heritability, genotypic, pheno-typic and environmental correlation in four edible oil crops. Heritabilities of flowering date, maturing date, plant height and weight of 1, 000 grains in rape were high. A highly significant positive correlation was found between flowering date and maturing date, plant hight and ear length, number of pods per ear and flowering date, maturing date and plant hight, The number of seed per pod showed also significant positive correlation with flowering or maturing date as well as with the relationship between weight of 1, 000 grains and plant height or ear length inrapeseed, respectively. Heritabilities of maturing date, length of stem with eapsule and number of seed per capsule were high, in sesame. Genotypic correlation between plant height and length of stem with capsule, length of stem with capsule and number of capsule per plant, number of capsule per plant and weight of 1, 000 grains, weight of 1, 000 grains and yield were highy positive in sesame. Heritabilities of flowering date, length of main stem, weight of 100 grains and number of shells per square meter in peanut were high, There was positive genotypic correlation between length of main stem and yield, number of shells per quare meter and matured seed ratio, number of shells per square meter and yield, 100 grains weight and yield. On the other hand, a significant negative correlation appeared between flowering date and yield. Heritabilities of days to flowering, stem length, stem diameter and weight of 1, 000 grains in perila were high. There was positive genotypic correlation between stem length and stem diameter, number of pods per plant, stem weight etc, between number of internodes and number of pods per plant, stem weight, number of valid branches and number of pods plant as well, respectively. While, a significant negative correlation was observed between number of valid branches and weight of 1, 000 grains, between number of pods per plant and weight of 1, 000 grains.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.592-599
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• 2019

This study aimed to develop an equation for estimating stem volume for Larix kaempferiin South Korea using independent variables, diameter at breast height (DBH), and height as being closely associated with stem volume. Analysis was conducted on the growth performance of 2,840 Larix kaempferi samples across South Korea after felling them and gleaning diameter data according to both stem height and stem analyses. In order to test the fitness of six different stem taper equations, empirical assessment was conducted for fitness index (FI), bias, mean, and absolute deviation (MAD), and coefficient variation (%CV). The two selectedmodels found to be optimal were the following: model one (V=a+bDBH²), established by employing DBH only; and model four (V=a+bDBH²H), established by utilizing DBH and height, respectively. The findings of non-linear regression indicated statistical significance (p < 0.05) in a and b, which were the coefficients for the intercepts and slopes of the models. The FI of the models ranged between 94% and 99%, and the bias was close to zero, while MAD ranged from 0.01 to 0.05, and %CV from 5.97 to 14.43, indicating a high level of fitness. Thus, using the suggested models, the basic information necessary for forest management was obtained, and an estimation of the stem volume was effected without delay soon after effecting DBH and height measurements.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.634-644
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• 2000

Sterba's theory that stem number maintaining maximum basal area per ha is maximum stem number of a stand, had been applied to data from 103 temporary plots in even-aged Pinus densiflora stands in Kangwon province, Korea and a maximum stem number and mortality model was prepared. DBH growth model which estimates dbh with the independent variables of stem number per ha and dominant height shows the good statistical performance, and explains well differences in dbh growth that would be caused by stem number per ha and dominant height. Basal area model derived from dbh growth model also explains well differences in basal area according to stem number per ha and dominant height. The maximum stem number curve, which is derived from stem number per ha at maximum basal area for dominant height and dbh, represents well the upper range of stem number per ha observed. And maximum stand density index derived from the maximum stem number model for dbh could be used for the index of maximum potential density of a stand. The maximum stem number model and maximum stand density index in this study were not based on stand data with maximum density but based on the temporary data from stands with various density. This maximum stem number model can be applied to the estimation of mortality and maximum potential volume.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.1-8
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• 1976

One of the most common needle leaf species used in planting in Korea is korean pine (Pinus koraiensis S. et Z.), and jack pine (Pinus banksiana Lamb.) is one of the test species for suitability. The relation of nursery bed density of 2-1 korean pine and 1-1 jack pine was studied at the Kwang Nung Nursery, Central Branch Station of Forest Research Institute, and about 40km north of Seoul. Nursery bed density of 2-1 korean pine, which ranged from 36 to 324 trees per square meters and of 1-1 jack pine, which ranged from 25 to 169 trees per square meters, had a marked effect on caliper, height, dry weight and percent and amount of plantable stock. The soil physical and chemical properties is silt plus clay, 50.55 percent; organic matter, 2.09 percent; total nitrogen, 0.13 percent; available phosphorus, 253.25 ppm; exchangeable potash, 0.46 m.e/100g; and pH, 5.58. As the density of the nursery seedling stand of 2-1 korean pine increases, the average tree height increases (Fig. 1A), but in 1-1 jack pine density do not affect to increase or decrease the average tree height. As the density of nursery bed increases, the average stem caliper (at 2cm above ground line) and dry weight decrease (Fig. 1B), but the decreasing rate is more seriously in 1-1 jack pine than 2-1 korean pine (Fig.5). As increasing the density of nursery bed, the T/R ratio of trees of the test species increase. Also the dry weight of leaf, stem and root parts are decreasing in proportion to the increase of stand density, but the drop rate of jack pine is more rapid than korean pine (table. 1) The patent facts of difference of growth characteristics between 2-1 korean pine and 1-1 jack pine were studied. These facts should be used to select the scale of stand density at the nursery bed or the plantable site. Korean pine is demanded high density, on the other hand in jack pine low density are more suitable to manage the stand density. Stands of comparatively low density had the greatest percentage of high-quality stock, and the stands of high density had less than the high quality trees of low density. An important criterion of the best density is percent and number of high-quality trees produced per square meter of bed area. Stem caliper and stem height of seedling is used in most public nurseries to sort seedling into plantable grades. The stock grade standard has set at 4.5mm caliper and 16cm height of 2-1 korean pine as the minimum desired stem caliper and height. By the result studies, the plantable stock grade standards of 2-1 korean pine used at stem height 16cm and stem caliper 4.5mm from public nurseries should be reformed to stem height 18cm and stem caliper 4.0mm by the growth characteristics and the tree distribution of stem height and caliper of relation to density. For the 2-1 korean pine, best density should be about 160 to 200 trees per square meter according to soil fertility. For the 1-1 jack pine, the suitable standard of plantable stock should be at stem height 25cm and caliper 6mm (at 2cm above ground line) and best density was about 100 to 120 trees.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.87-91
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• 2013

The major characteristics of the developed corn hybrids were compared at each different planting time; 1st time(April 28) and 2nd time(August 20), respectively. Among traits surveyed, stem height showed highly at 1st time than 2nd, while ear height, stem diameter and ear length were similar at two times. Sugar content of the used hybrids showed highly at 2nd planting time than 1st. Pericarp thickness was also high at 2nd planting time. Especially, among hybrids CNU99 was the highest in stem height and ear length, CNU11 and CNU56 were high in sugar content, and CNU51 and CNU124 were thiner than other hybrids in pericarp thickness. Accordingly, these hybrids will be planted and recognized in 2nd yield trial for superior corn hybrid selection.