• Korean Journal of Environment and Ecology
• /
• v.2 no.1
• /
• pp.1-8
• /
• 1988

To investigate the forest structure of Guryongsa-Birobong area in Mt. Chiak, four districts were selected and forty-five plots were set up at the districts. The leading dominant species of District I, the valley forest in which users' density was very high. was Pinus densiflora. That of District II, the valley forest in which users' density was high. and Districs III, the valley forest in which entering was restricted recently. was Comus controversa. That of District III, the ridge forest in which users' density high, was Quercus mongolica. Species diversities of District I, II, III, and IV were 1.3252, 1.3736, 14421, and 1.2546, respectively. DCA ordination were showed that successional trends of tree species seem to be from Pinus densiflora through Quercus spp. to Carpinus laxtflora in ridge and midslope forest and from Pinus densiflora through Quercus spp. to Comtus controversa and Carpinus cordata.

• Journal of Korean Society of Transportation
• /
• v.28 no.4
• /
• pp.85-93
• /
• 2010

Unlike the existing subway service evaluation system, service evaluation indices by travel section in 26 subway stations were developed and appraised. Travel sections were classified into (1) subway station approach, (2) from entrance to platform, (3) platform, and (4) passageway for transfer, after which weights by travel section and by service evaluation index were estimated using analytic hierarchy process (AHP) by transportation experts. Subway service satisfaction data was gathered from 2000 passengers at the 26 subway stations. The results showed that the weights of (1) subway station approach and (4) passageway for transfer were highest and the weights by travel sections were different if kinds of services were the same. Comfort on the platform, crowdedness in the passageway for transfer, and transfer information from entrance to platform were highest in order in terms of satisfaction. Meanwhile, the results of the IPA showed that services in the passageway for transfer were high in terms of weights but were relatively low in terms of satisfaction. Therefore the services in passages for transfer needed to be reformed preferentially.

• The Korean Journal of Applied Statistics
• /
• v.21 no.3
• /
• pp.429-439
• /
• 2008

Canonical correlation biplot is 2-dimensional plot for investigating the relationship between two sets of variables and the relationship between observations and variables in canonical correlation analysis graphically. In general, biplot is useful for giving a graphical description of the data. However, this general biplot and also canonical correlation biplot do not give some concise interpretations between variables and observations when the number of observations are large. Recently, for overcoming this problem, Choi and Kim (2008) suggested a method to interpret the biplot analysis by applying the K-means clustering analysis. Therefore, in this study, we will apply their method for investigating the relationship between skill and competition score factors of KLPGA players using canonical correlation biplot and cluster analysis.

• Journal of Wetlands Research
• /
• v.8 no.1
• /
• pp.83-96
• /
• 2006

In this study, hydraulic flood routing is performed by 1-Di. unsteady flow model, FLDWAV on the downstream of Nakdong river. For input information, KOWACO Rainfall-Runoff Model is used and resonable boundary condition is constructed. As the result of the application about the past flood event, good agreement of comparison with observed and calculated values are show in the interesting sites, Jindong and Samrangjin. Additionally, estuary barrage's WSL evaluation procedure is enhanced to accurate calculation, and it is defined by downstream boundary condition in Nakdiong river. The new regressive equation to calculate the predicted tide value is developed by considering the astronomical tide and past observed tide value at Nakdong estuary barrage. The guideline's construction of the new application and flood forecasing system of other river basins is possible by using this studied results.

• Journal of Digital Convergence
• /
• v.14 no.3
• /
• pp.345-359
• /
• 2016

This study aims at providing information on golf industry by survey about effects on purchase decision factors of golf goods and strategies on brand attitude and purchase behavior. As a result of this study, there are sixth reasonable factors of effects as follows. First, age, education and average golf score were meaningful factors on purchase decision. Second, sex and age were significant factors on brand attitude. Third, age was the only meaningful factor on purchase behavior. Fourth, purchase decision factors of golf goods showed significant (+) effects on brand attitude. Fifth, purchase decision factors of golf goods showed significant (+) effect on purchase behavior. Sixth, brand attitude showed significant (+) effect on purchase behavior.

• Korean Journal of Ecology and Environment
• /
• v.53 no.4
• /
• pp.331-335
• /
• 2020

The red swamp crawfish (Procambarus clarkii) is native to northeastern Mexico and south-central United States. But the species has been introduced to other parts of the world, and cause ecological problems including habitat destruction and competition with indigenous species. In this study, we identified the distribution of P. clarkii in the freshwater system in Korea. P. clarkii were collected in the field sampling and it is assumed that they have settled in major domestic water systems of Korea including six points in the Yeongsangang River, five points in the Mangyeonggang River, two points in the Seomjingang River, and one point in the Geumgang River. In particular, more than 20 individuals were found in Seobongri, Wanjugun and Mosanri, Hampyeonggun, which are believed to form a relatively large population. Considering high mobility and environmental adaptability of the species, the possibility of their dispersal to other water systems is very high. Therefore, continuous monitoring and assessment of their distribution and potential spread are required and effective management to remove them policy is needed to prevent damage in the Korean ecosystem.

• Korean Journal of Environmental Biology
• /
• v.36 no.1
• /
• pp.73-81
• /
• 2018

This study was conducted to understand the current status of the translocated species using a precede study and a model to evaluate the potential invasiveness that could adversely affect the aquatic ecosystem in the Gangneungnamdae Stream. A total of 12 translocated species were investigated and identified from 9 sites in a precede study, and steadily increased since 1982. For the study, which utilized research based on the total FISK (Fish Invasivenss Screening Kit) scores, all of the non-native fishes in Gangneungnamdae Stream were classified into two groups: namely as a high and a medium risk of becoming invasive. It was determined that there were two species (Zacco platypus and Pseudorasbora parva) that were determined to have posed the highest risk. The study determined that the mean scores were shown to have ranged from $3.06({\pm}0.16)-3.42({\pm}0.13)$. Consequently, the habitat analysis showed that the determined QHEI (Qualitative Habitat Evaluation Index) values in the stream averaged 146 (88-171), indicating that an optimal habitat condition did exist in that locale. It can be inferred that compared to land use in the surrounding watersheds, the QHEI values and frequency of translocated species showed the lower the altitude of stream, the QHEI values were decreased and in case of land use pattern, a noted decreased forest and grassland area, and gradually increased urbanized area was seen to exist in the region. The correlation between the fish assemblage, QHEI, land use pattern of surrounding watershed and number of translocated species was identified and analyzed when the stream altitude decreased, and the number of species was increased (r= - 0.782, p=0.0127), the number of species was decreased (r= - 0.737, p=0.0234), and finally when the QHEI values were decreased, it was noted that the urbanized area was increased (r=0.292, p=0.446). In the case of the number of translocated species, when the number of translocated species was increased, the associated urbanized area was increased.

• Journal of the Korean Wood Science and Technology
• /
• v.2 no.2
• /
• pp.8-12
• /
• 1974

1. If one unity is given to the prongs whose ends touch each other for estimating the internal stresses occuring in it, the internal stresses which are developed in the open prongs can be evaluated by the ratio to the unity. In accordance with the above statement, an equation was derived as follows. For employing this equation, the prongs should be made as shown in Fig. I, and be measured A and B' as indicated in Fig. l. A more precise value will result as the angle (J becomes smaller. $CH=\frac{(A-B') (4W+A) (4W-A)}{2A[(2W+(A-B')][2W-(A-B')]}{\times}100%$ where A is thickness of the prong, B' is the distance between the two prongs shown in Fig. 1 and CH is the value of internal stress expressed by percentage. It precision is not required, the equation can be simplified as follows. $CH=\frac{A-B'}{A}{\times}200%$ 2. Under scheduled drying condition III the kiln, when the weight of a sample board is constant, the moisture content of the shell of a sample board in the case of a normal casehardening is lower than that of the equilibrium moisture content which is indicated by the Forest Products Laboratory, U. S. Department of Agriculture. This result is usually true, especially in a thin sample board. A thick unseasoned or reverse casehardened sample does not follow in the above statement. 3. The results in the comparison of drying rate with five different kinds of wood given in Table 1 show that the these drying rates, i.e., the quantity of water evaporated from the surface area of I centimeter square per hour, are graded by the order of their magnitude as follows. (1) Ginkgo biloba Linne (2) Diospyros Kaki Thumberg. (3) Pinus densiflora Sieb. et Zucc. (4) Larix kaempheri Sargent (5) Castanea crenata Sieb. et Zucc. It is shown, for example, that at the moisture content of 20 percent the highest value revealed by the Ginkgo biloba is in the order of 3.8 times as great as that for Castanea crenata Sieb. & Zucc. which has the lowest value. Especially below the moisture content of 26 percent, the drying rate, i.e., the function of moisture content in percentage, is represented by the linear equation. All of these linear equations are highly significant in testing the confficient of X i. e., moisture content in percentage. In the Table 2, the symbols are expressed as follows; Y is the quantity of water evaporated from the surface area of 1 centimeter square per hour, and X is the moisture content of the percentage. The drying rate is plotted against the moisture content of the percentage as in Fig. 2. 4. One hundred times the ratio(P%) of the number of samples occuring in the CH 4 class (from 76 to 100% of CH ratio) within the total number of saplmes tested to those of the total which underlie the given SR ratio is measured in Table 3. (The 9% indicated above is assumed as the danger probability in percentage). In summarizing above results, the conclusion is in Table 4. NOTE: In Table 4, the column numbers such as 1. 2 and 3 imply as follows, respectively. 1) The minimum SR ratio which does not reveal the CH 4, class is indicated as in the column 1. 2) The extent of SR ratio which is confined in the safety allowance of 30 percent is shown in the column 2. 3) The lowest limitation of SR ratio which gives the most danger probability of 100 percent is shown in column 3. In analyzing above results, it is clear that chestnut and larch easly form internal stress in comparison with persimmon and pine. However, in considering the fact that the revers, casehardening occured in fir and ginkgo, under the same drying condition with the others, it is deduced that fir and ginkgo form normal casehardening with difficulty in comparison with the other species tested. 5. All kinds of drying defects except casehardening are developed when the internal stresses are in excess of the ultimate strength of material in the case of long-lime loading. Under the drying condition at temperature of $170^{\circ}F$ and the lower humidity. the drying defects are not so severe. However, under the same conditions at $200^{\circ}F$, the lower humidity and not end coated, all sample boards develop severe drying defects. Especially the chestnut was very prone to form the drying defects such as casehardening and splitting.

• Korean Journal of Environment and Ecology
• /
• v.16 no.1
• /
• pp.87-93
• /
• 2002

The tree of heaven naturalized plant grows in the various habitats of the city. The principal reason is that it is reproduced not only through sexual reproduction but through asexual reproduction. By the spreading of sucker and a bud appearance of the seed it forms a group easily inside the city habitat. The distribution of seed and spreading of the seedlings of the tree of heaven were investigated like the followings. As the result of the sexual reproduction by the seed and hangs in cluster farm, 350 individuals are germinated at the Namsan the best environment, and 50 individuals at Toegyewon Rotary These seeds are dispersed by the effect of wind and geographical factor. Because the northwest wind is blowing mainly from late autumn to early spring, it is dispersed in the south. In Toegyewon Rotary, a slant site, is dispersed mainly by down the site. Compared with width of crown, the seedling of a seed germination are distributed outside more than inside the crown and the seed is spreaded until the maximum 7.5 times of crown width at the investigated area. 1 year seedlings appeared as a group at the place of 2-4 times of the crown (in 20m from the crown, 75% distribution). Considering the distribution by the seed scattering of the tree of heaven, there is a possibility of sudden individual increase even in the deteriorated city environment. So this possibility shows that we need to consider the protection of the city soil, and the species variety decrease resulted from the successful competition to the other species.

• Journal of Korean Society of Forest Science
• /
• v.68 no.1
• /
• pp.52-59
• /
• 1985

This study was carried out to compare the diameter increment of Pinus densiflora for.erecta, Pinus koraiensis, Larix leptolepis, Abies holophylla and Abies koreana growing in middle area of Korea. The results obtained were summarized as follows; 1) The difference in annual diameter increment among five species according to D.B.H classes showed to be the strongest in Pinus koraiensis the second rank Larix leptolepis, the third rank Pinus densiflora erecta, the fourth rank Abies holophylla and the weakest in Abies koreana. 2) It was inferred that when the D.B.H of Pinus densiflora for.erecta comes to 95cm, Pinus koraiensis 80cm, Larix leptolepis 80cm, Abies holophylla 140cm and Abies koreana 85cm respectively, their diameter do not increase. 3) Total D.B.H increment among five species according to tree age classes were ranked as follows; Larix leptolepis, Pinus koraiensis, Pinus derasiflora for.erecta, Abies holophylla and Abies koreana. 4) It was inferred that when the age of Pinus densiflora for.erecta comes to 200yrs, Pinus koraiensis 120yrs, Larix leptolepis 120yrs, Abies holophylla 260yrs and Abies koreana 300yrs respectively, their diameter do not increase. 5) Abies koreana showed the lowest diameter increment in comparison with other four species, while diameter increment in Abies holophylla and Abies koreana decreased in later age than other species.