• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.33-45
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• 1978

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1975 following after the selection of 1974, twenty trees from each of three natural populations of the species were selected and their open-pollinated seeds were collected, and the locations and conditions of the populations ate presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our second report of this series, in which Myong-Ju and Ul-Jin populations were regarded to be superior phenotypically to suweon population. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period (1931~1960) measured from the nearest meteorological stations to each population are shown in fig.2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Suweon area, population 6, were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index, i.e., length to diameter ratio are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be highly significant in population differences and family differences within population. 3. The morphological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed-wing length, seed-wing index, seed weight, seed-length and seed index but not among the populations in the other observed traits. The values of correlation coefficient between the characters of cone and seed are given in table 10 and the positive significant correlations can be observed in the most parts of the compared traits. 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 and 1-1 seedling height of these progenies. But the differences in root collar diameter are shown only among families within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. The number of stomata row on both sides of needle and the serration density were measured in the seedlings from each of the families of the three populations. As shown in table 15, statistical differences are considered to be significant among the populations and among the families within population in serration density but not among the populations in stomata row on both sides of the needle. The results differ from those of the third report of this series. Even if one of the reason seems to be the diversity of selected populations, it could not be confirmed definitely. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.266-274
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• 2020

This paper reports a means of improving the abnormal noise of light tactical vehicles (LTVs) by applying a vehicle fitting type generator (hereinafter called generator). LTVs are classified as having generators, and there are no differences in the noise level. On the other hand, quality improvement was performed in response to unpleasant noise felt by the user (hereinafter called abnormal noise) during vehicle operation. To improve the quality, the generator mounting structure and the phenomenon of the vehicle in the problem were identified. Through this, it was confirmed that the noise caused by the generator installation was the rattle noise. Rattle noise at the engine driving system is normally caused by the transfer of irregular torque generated by the engine power stroke and the backlash by the spline-serration fitting structure between the engine coupler and rotor assembly in a generator. Therefore, this study established an improvement plan to apply a damper coupler to solve the cause of the abnormal noise. Regarding the improved establishment method, the improvement effect was confirmed from the influence of the irregular torque of the engine, noise level, dynamic characteristics analysis, and the endurance test of the parts.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.655-662
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• 2014

This study conducted tensile tests on an Alloy 690TT tube at room temperature (RT) and at $343^{\circ}C$ using tube- and ring-type specimens to investigate the stress-strain behavior and tensile properties of a steam generator (SG) tube in the axial and circumferential directions at RT and at the design temperature of a nuclear power plant (NPP). The results of the axial tensile test showed that yield point phenomena appeared at both RT and $343^{\circ}C$, and serrated flow in the stress-strain curve appeared at $343^{\circ}C$. Yield and tensile strengths for both directions were clearly lower at $343^{\circ}C$ compared to RT; however, the elongations were approximately the same at both test temperatures. Regardless of the test temperature, the strengths in the circumferential direction were lower by approximately 5~10 % than those in the axial direction. In addition, the test data revealed that the reduction in the yield and tensile strengths of the Alloy 690TT SG tube with the test temperature was more significant than that estimated by the temperature correction factor of ASME Sec.II.

• Journal of Korean Society of Forest Science
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• v.57 no.1
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• pp.39-44
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• 1982

These studies were carried out to know the variation of needle characteristics of Abies Koreana distributed in Korea. The results are summarized as follows. The differences of needle length and number of stomata row among the population were shown one percent level, but not in each individual tree. Correlations coefficients between the D.B.H. and needle length or needle width of mother trees were not correlated all populations respectively. It was found that correlation coefficient between needle length and needle width was positive in two populations. of Mt. Doukyou and Mt. Hanla, but it was not in Mt Jiri. Correlation coefficient between needle length and the number of stomata row positive correlation in Mt. Doukyou. Correlation coefficient between needle width and the number of stomata row was shown positive in all populations, but it was not that correlation coefficient between needle width and density of serrations, and between number of stomata row and density of serrations. The coefficients of variations were shown higher density of serration than needle length, needle width and stomata row.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.377-381
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• 2014

In this study, we report for the first time a hybridization between Caretta caretta and Chelonia mydas in South Korea. On 7th May 2012, a sea turtle (Jeju sea turtle 01, JST01) was found in the east coast of Jeju Island, South Korea. The morphological characteristics of JST01 were compared with those of C. caretta and C. mydas that were frequently observed in Korean Seas. Interestingly, JST01 showed similar morphological characters such as body color, appearance of carapace, shape of upper beak, serration on marginal scute, and two claws with those of C. caretta. On the other hand, JST01 showed also similar patterns in several characteristics including the numbers of marginal, inframarginal and costal scute, smooth carapace without keel, no contact between costal scute and nuchal scute with those of C. mydas. From these results, we suggest that JST01 is one of hybrid animals bred between C. caretta and C. mydas, because JST01 has species-specific characters from both species. We anticipate that our study would be useful and have significant impact onto study inter-specific hybridization in the groups of sea turtle.

• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.1-8
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• 1983

Classification on the group of Salix pseudo-lasiogyne growing in Korea, was conducted using cluster analysis, factor analysis, and principal component analysis. Thirty-six characters(Table 2) of the 5 basis species were measured. The phenograms and ordination plot showing the relationships between the species were made by applying the cluster analysis and principal component analysis. Five important factors, such as leaf blade width, number of right serration, angle of leaf apex, number of flowers in an ament, and the ratio of petiole length to width, were inferred from the rotated factor matrix, and their state values were presented in polygonal diagram. Salix pseduo-lasiogyne and S. babylonica were similarly correlated and linked in one group, S. dependens and S. matsudana for tortuosa were secondarily linked in the other group. S. koreensis appeared as an aliemated species from each of the two groups.

• Journal of Korean Society of Forest Science
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• v.31 no.1
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• pp.8-20
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• 1976

For study on the variation of natural stand, three populations of Pinus densiflora S. et Z. were selected at samsanri Yongogmyun Myongjugun Kangwondo (4), Hawonri seomyun Uljingun Kyongbuk (5), and Emogdong Suweon Kyongkido (6) successibely after the selection of three population in 1974. Twenty individual trees were chosen from each population and the morphological characteristics of trees, needle and wood properties were investigated on the trees. The results are summerized as follows; 1. Serration density, resin canal number in needle did not show significant differences, however stomata row number in the both sides of needle showed highly significant differences among 3 populations. But significant differences were calculated among individual trees in a population regarding any character of needles. 2. Ail population had high correlation on the stomata row between abaxial and adaxial side of needle. 3. The Myongjungun population showed the highest value of resin duct index, which means the population had the highest degree of hybrid character. 4. The ring segment width and summerwood percentage in the wood properties had significant differences, and yet specific gravity and tracheid length had not significant differences statistically among 3 populations. But all the values were significant statistically among the ring segments within population. 5. The ring segment width decreased rapidly with increasing tree age but summerwood percentage, specific gravity, tracheid length increased slowly to the middle age of tree and then decreased slowly after the age. But the patterns of decrease or increase were some different by population. 6. The values of Uljingun population were generally high in the coefficient of variation on all the needle characters. And the values of Suweon population were always the highest and those of Myongjugun population the lowest in the coefficient of variation on all the wood properties.

• Journal of Korean Society of Forest Science
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• v.40 no.1
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• pp.1-18
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• 1978

Three Pinus densiflora populations as shown in location map (Fig. 1) were studied in 1977. These succeed the population numbers 10, 11 and 12 after the preceeding populations. Following the previous study methods, 20 trees were chosen from each population and the morphological characteristics such as tree forms, branching habit, needle and wood properties were investigated. The results are summerized as follows; 1. The mean stand ages were ranged from 40 to 45. The growth performances of trees of population 10 and 11 was similar, but 12 seemed to be inferior more or less. 2. The ratios of clear bole length was 0.53 in population 12 as the highest but 0.43 for population 10 as the lowest. 3. The population 12 was considered to be a stand of the coarser branching habit having the crown index (The maximum crown diameter/the crown length) 1.65 though the mean branching angle indicates almost horizontal. 4. The differences were observed in the clear bole length ratios and crown-indices between populations as shown in Fig. 3 and 4. 5. No inter-population differences in serration density of needle was shown but significant inter and intra-population and individual differences (within population) in number of stomata rows and resin duct. 6. Population 12 shown 0.119 of resin duct index as the maximum. 7. The pattern of diameter growth, analyses based on the width of 10-year-ring segment unit (for example, the 1st segment denotes the width between pith center and 10th year ring and the 2nd one is from 11th to 20th year ring and so on.), was alike among populations as shown in Fig. 9. 8. No significant differences between population in mean summer wood percentages as well as in wood specific gravity was observed. The values of wood specific gravity were increased with the increase of ages in population 10 and 11 however vice versa in population 12. 9. The fiber length was increased with the increase of age but no differences between populations as shown in Fig. 12.

• Korean Journal of Pharmacognosy
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• v.7 no.3
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• pp.179-190
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• 1976

1. The Korean Acanthopanax genus includes 12 kinds consisting of 9 species and 3 forma. 2. The Korean Oga-pi which is on market sale has been used as bark for the medicinal purpose, and Oga-pi shall use Radicis Cortex. That is why it is basic rule that herbalogy shall use Radicis Cortex. 3. The origin of Oga-pi on sale is Acanthopanax sessiliflorum forma chungbunensis C.S. Yook. 4. $C_{HUNG}\;and\;N_AKAI'S}$ report on A. koreanum told us that there are brown hair on the mid-leaf junction, but in addition to it, our investigation was resulted in the fact that there are thorn along mid-rib sometimes. 5. 2 kinds of new forma are similar to A. sessiliflorum, but are different in the view-point of chemotaxonomy, compared with A. sessiliflorum. In its morphology, we can find some difference between 2 kinds of new forma and A. sessiliflorum. Our effort of examination on documents tell us that the all plants growing in the central part of our country is A. sessiliflorum forma chungbunensis C.S. Yook. The one which has thorn on both side among the plants collected in Mt. Dukyu, is called A. sessiliflorum forma nambunensis C.S. Yook. 6. A. sessiliflorum is growing in the southern part in Korea, and most Chungbu Oga-pi A. sessiliflorum forma chungbunensis in the central part of our country. For the convenience of our study, the key of Korean Acanthopanax plant is classified into, I-IV, as shown on the following items: I. No hair on both side of leaf A. Flower stalk is longer than petiole, and there are thorn under the petiole (5-7 stigma).${\cdots}A.\;sieboldianum$. B. Flower stalk is longer than petiole, or same length. The serration lie down, and the stem has short thorn (stigma is divided into 3 part).${\cdots\;\cdots}A.\;seoulense$ II. There are a lot of thorn or hair on back of leaf. A. A lot of thorn and hair on the vein of leaf back, and a number of small thorn on petiole.${\cdots}A.\;chiisanensis$. B. There are thorn on the vein of leaf back.${\cdots\;\cdots}A.\;sessiliflorum\;forma\;chungbunensis.$ III. There are hairs on both side of leaf. A. There are small hairs on the back of leaf.${\cdots\;\cdots}A.\;sessiliflorum.$ B. There are small hairs on both side of leaf.${\cdots\;\cdots}A.\;sessiliflorum\;f.\;nambunensis.$ C. There are thick hairs on junction of main vein on back of leaf.${\cdots\;\cdots}A.\;koreanum.$ D. There are brown hairs on vein of leaf back, and brown hairs on small petiole.${\cdots\;\cdots}A.\;rufinerve.$ E. There are shrunk hairs in grey-brown on back of leaf, and tense hairs on new branch (one stigma).${\cdots\;\cdots}A.\;divaricatum.$ IV. There are long thorn, just like needles, on the stem and petiole. A. Long needle grows on whole stem tensely, and long needles on petiole.${\cdots\;\cdots}A.\;senticosus.$ B. There are no needles, just like needles aid hairs on petiole, and needles grow on the stem thinly.${\cdots\;\cdots}A.\;asperatus.$ C. There are no needle on small brarch, leaf and inflorescence are larger than A. senticosus. ${\cdots\;\cdots}A.\;senticosus\;forma\;inermis.$.

• Journal of Korean Society of Forest Science
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• v.44 no.1
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• pp.1-25
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• 1979

Six natural populations of Pinus densiflora S. et Z. as shown in the location map (Flg 1) were studied during 1978. The numerial pouplation codes, 13 to 18. The results of populations 1 to 12 were reported in previous papers. Following the study methods described before, 20 trees were sampled from each population and morpological characteristics such as stem forms, branching habit needle and wood properties investigated. The results are summerized as follows; 1. The mean stand ages were ranged from 36 to 97 of years. The growth performances of trees of population 14. 15 and 18 was similar, but 13, 16, and 17 seemed to be inferior more or less. 2. The ratios of clear bole length were 0.70 in population 18 as the highest but 0.28 for population 16 as the lowest. 3. The population 17 was considered to be a stand of the coarser branching habit having the crown index (The maximum crown diameter/the crown height) 158 though the branching angles were almost horizontal. 4. The differences were observed in the clear bole length ratios and crown-indices between population as shown In Fig. 3 and 4. 5. As to the serration density, number of stomata row and resin duct; the significant differences exist between individual trees within population and also between populations. 6. Population 18 shown resin duct index 0.119 as the maximum. 7. The patterns of diameter growth, based on the width of 10-year-ring segment unit(for example, the 1st segment denotes the with between pith center and 10th year ring and the 2nd one is from 11th to 20th ring and so on.), were alike among populations as shown in Fig 9. 8. Significant differences between population in mean summer wood percentage as well as in wood specific gravity was observed. The values of wood specific gravity were increased with the increase of ages in population 14, 18 however vice versa in population 13, 15, and 17. 9. The fiber length was mereased with the increased of age but no differences between populations as shown in Fig. 12.