• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.42-59
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• 2017

To investigate rooting and community forming ability, sod strips of Gramineae such as Miscanthus sacchariflorus (Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg., and Arundinella hirta(Thunb.) Tanaka were planted horizontally at a width of 10~15cm in October 2010 on the bank slope of Kwangju Stream in Korea. Seeds of each species were sown in April 2010 in plastic seedbeds(60cm length ${\times}$ 30cm width ${\times}$ 5cm depth) filled with 4cm of garden soil and grew until October 2010 to form rectangular sod, which then was cut into multiple strips(20cm length ${\times}$ 6cm width ${\times}$ 4cm root depth). Weeds growing on the experiment sites were removed twice a year until those four species had formed a community by 2013. Weeds were not eradicated during 2014 and 2015 to observe whether the community formation can be maintained without weed removal. t-tests on stem numbers and heights in May, July, and September were conducted between 2013 and 2014, and between 2014 and 2015. Stem numbers and heights of the four species in 2014 were significantly decreased(p<0.001) compared with those in 2013 due to weed damage to their growth in 2014. Stem numbers and heights of Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. in 2015 were similar to those in 2014(p>0.05). Stem numbers and heights of Arundinella hirta(Thunb.) Tanaka in 2015, however, were significantly reduced compared with those in 2014(p<0.001) due to weed impact on its growth. After three years of weed removal, a community of each species was formed. Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. were able to establish communities without any further weed removal. Arundinella hirta(Thunb.) Tanaka, however, was not able to maintain its community due to considerable damage to its growth caused by weeds even after three years of weed removal. Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. are more suitable to sod strip plantings on stream bank slopes in terms of the maintenance of community formation without weed eradication. t-test on stem numbers and heights each September during the five year experiment period between sod strip planting and potted plants of the four species were conducted. Stem numbers of strip sod plantings were significantly higher(p<0.001) than those of potted one. Heights of strip sod plantings, however, were significantly lower(p<0.05) than those of the potted samples. Therefore, strip sod planting is more advantageous regarding bank slope erosion protection due to the higher number of stems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.697-704
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• 2013

The inhibitory effect of ethanol extracts from Curdrania tricuspidata leaves (CTL) on osteoarthritis was investigated in primary cultured rat cartilage cells and a monosodium-iodoacetate (MIA)-induced arthritis rat model. To identify the effects of CTL 80% ethanol extracts (CTL80) and CTL 10% ethanol extracts (CTL10) against $H_2O_2$ treatment in vitro, cell survival was measured by the MTT assay. Cell survival after $H_2O_2$ treatment increased with CTL80 and CTL10 close to normal up to $300{\mu}g/mL\;H_2O_2$. The mRNA expression of matrix metalloproteinases (MMPs) was determined MMP-7 and MMP-13 (known catabolic factors), were significantly inhibited by CTL 80 and CTL10; a $200{\mu}g/mL$ dose of CTL80 especially decreased MMP-13 expression. In vivo, osteoarthritis was induced by an intra-articular injection of MIA into the knee joints of rats, then CTL80 and CTL10 orally administered daily for 35 days. After the animals were sacrificed, histological evaluations of their knee joints revealed a reduction in polymorphonuclear cell infiltration and smooth synovial lining in the CTL80-500 group. Micro-CT analysis of hind paws from CTL80-500 and CTL10 showed a protection against osteophyte formation, soft tissue swelling, and bone resorption. In conclusion, CTL ethanol extracts are effective in ameliorating joint destruction and cartilage erosion in MIA-induced rats. CTL decreases and normalizes articular cartilage through preventing extracellular matrix degradation and chondrocyte injury, and could potentially serve as a therapeutic treatment for humans.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.12-24
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• 2020

The purpose of this study is to analyze the influence of the water system on the location, spatial structure, and construction method of Hongju-eupseong, centering on Hongjumok-eupchi. During the Joseon Dynasty, the water system in Hongjumok-eupchi is composed of artificially constructed Seong-an Runnel and ponds based on a branch-shaped natural waterways flowing from south to north and west to east. Compiling the results of various literature records, excavations and analysis of map data, it can be seen that the water system has an important influence on the construction of Hongju-seong. Firstly, Hongju-seong from the Goryeo Dynasty to the late Joseon Dynasty is located using a circular shape of topographical structure and a small erosion basin formed on the inner side of the Hongseongcheon and Wolgyecheon streams without significant change in location. In particular, Wolgyecheon and Hongseongcheon are natural moats, which are harmonized with Sohyangcheon and riverside topographical structures, affecting the location and construction method of Hongju-seong, water related facilities, and the spatial structure of eupseong. It is understood that location characteristic of Hongju-seong reflects the urban location structure harmonized with waterways in ancient China and Korea. Secondly in harmony with the water system and topographic structure of Hongju-seong, it is an important factor in deciding the land use of the town, the arrangement of the town hall facilities and inducing various non-subsidiary measures such as the establishment of embankment forest with a secret function and the closure of the south gate. In addition, artificial drainage facilities such as Seongan runnel and ponds are being actively introduced from early on to protect the walls or towns from flooding of Wolgyecheon. Especially there were typical methods for protecting the walls from water damage such as the Joseon Dynasty stone castle structure that was integrated with saturn(soil wall) in the Goryeo Dynasty, retreating wall in the northern gate area in the late Joseon Dynasty, and the method of constructing wall using korean tile and stone floors between reinforced soil layers in the western and northern wall.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.11-25
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• 1979

There was much mass movement at many different mountain side of Peong Chang area in Kwangwon province by the influence of heavy rainfall through August/4 5, 1979. This study have done with the fact observed through the field survey and the information of the former researchers. The results are as follows; 1. Heavy rainfall area with more than 200mm per day and more than 60mm per hour as maximum rainfall during past 6 years, are distributed in the western side of the connecting line through Hoeng Seong, Weonju, Yeongdong, Muju, Namweon and Suncheon, and of the southern sea side of KeongsangNam-do. The heavy rain fan reason in the above area seems to be influenced by the mouktam range and moving direction of depression. 2. Peak point of heavy rainfall distribution always happen during the night time and seems to cause directly mass movement and serious damage. 3. Soil mass movement in Peongchang break out from the course sandy loam soil of granite group and the clay soil of lime stone and shale. Earth have moved along the surface of both bedrock or also the hardpan in case of the lime stone area. 4. Infiltration seems to be rapid on the both bedrock soil, the former is by the soil texture and the latter is by the crumb structure, high humus content and dense root system in surface soil. 5. Topographic pattern of mass movement spot is mostly the concave slope at the valley head or at the upper part of middle slope which run-off can easily come together from the surrounding slope. Soil profile of mass movement spot has wet soil in the lime stone area and loose or deep soil in the granite area. 6. Dominant slope degree of the soil mass movement site has steep slope, mostly, more than 25 degree and slope position that start mass movement is mostly in the range of the middle slope line to ridge line. 7. Vegetation status of soil mass movement area are mostly fire field agriculture area, it's abandoned grass land, young plantation made on the fire field poor forest of the erosion control site and non forest land composed mainly grass and shrubs. Very rare earth sliding can be found in the big tree stands but mostly from the thin soil site on the un-weatherd bed rock. 8. Dangerous condition of soil mass movement and land sliding seems to be estimated by the several environmental factors, namely, vegetation cover, slope degree, slope shape and position, bed rock and soil profile characteristics etc. 9. House break down are mostly happen on the following site, namely, colluvial cone and fan, talus, foot area of concave slope and small terrace or colluvial soil between valley and at the small river side Dangerous house from mass movement could be interpreted by the aerial photo with reference of the surrounding site condition of house and village in the mountain area 10. As a counter plan for the prevention of mass movement damage the technics of it's risk diagnosis and the field survey should be done, and the mass movement control of prevention should be started with the goverment support as soon as possible. The precautionary measures of house and village protection from mass movement damage should be made and executed and considered the protecting forest making around the house and village. 11. Dangerous or safety of house and village from mass movement and flood damage will be indentified and informed to the village people of mountain area through the forest extension work. 12. Clear cutting activity on the steep granite site, fire field making on the steep slope, house or village construction on the dangerous site and fuel collection in the eroded forest or the steep forest land should be surely prohibited When making the management plan the mass movement, soil erosion and flood problem will be concidered and also included the prevention method of disaster.

• Journal of Korean Society of Forest Science
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• v.20 no.1
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• pp.1-44
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• 1973

Needless to say, the management of national forest in all countries is very important in view of the national mission and management purposes. Korean national forest is also in particular significant in promoting national economy for the continuous increasing of the demand for wood, conservation of the land and social welfare. But there's no denying the fact that the leading aim of the Korean forest policy has been based upon the conservation of forest resources and recovery of land conservation function instead of improvement of the forest productive capacity. Therefore, the management of national forest should be aimed as an industry in the chain of the Korean national economy. And the increment of the forest productive capacity based on rationalized forest management is also urgently needed. Not only the increment of the timber production but also the establishment of the good forest in quality and quantity are to bring naturally many functions of conservation and other public benefits. In 1908 Korean national forest was historically established for the first time as a result of the notification for ownership, and was divided into two kinds in 1911-1924, such as indisposable national forest for land conservation, forest management, scientific research and public welfare, and the other national forest to be disposed. Indisposable forest is mostly under the jurisdiction of national forest stations (Chungbu, Tongbu, Nambu), and the tother national forests are under custody of respective cities and provinces, and under custody of the other government authorities. As of the end of 1971, national forest land is 19.5% (1,297,708 ha) of the total forest land area, but growing stock is 50.1% ($35,406,079m^3$) of the total forest growing stock, and timber production of national forest is 23.6% ($205,959m^3$) of the year production of total timber in Korea. Accordingly, it is the important fact that national forest occupies the major part of Korean forestry. The author positively affirms that success or failure of the management of national forest controls rise or fall of forestry in Korea. All functions of forest are very important, but among others the function of timber production is most important especially in Korea, that unavoidably imports a large quantity of foreign wood every year (in 1971 import of foreign wood-$3,756,000m^3$, 160,995,000 dollars). So, Korea urgently needs the improvement of forest productive capacity in national forest. But it is difficult that wood production meets the rapid increase of demand for wood to the development of economy, because production term of forestry is long, so national forest management should be rationalized by the effective investment and development of forestry techniques in the long view. Although Korean national forest business has many difficulties in the budget, techniques and the lack of labour due to outflow of rural village labour by development of national economy, and the increase of labour wages and administrative expenses etc. the development of national forest depends on adoption of the suitable forest techniques and management adapted for social and economical development. In this view point the writer has investigated and analyzed the status of the management of national forest in Korea to examine the irrational problems and suggest an improvement plan. The national forestry statistics cited in this study is based on the basic statistics and the statistics of the forest business as of the end of 1971 published by Office of Forestry, Republic of Korea, and the other depended on the data presented by the national forest stations. The writer wants to propose as follows (seemed to be helpful in improvement of Korean national forest management). 1) In the organization of national forest management, more national forest stations should be established to manage intensively, and the staff of working plan officials should be strengthened because of the importance of working plan. 2) By increasing the staff of protection officials, forest area assigned for each protection official should be decreased to 1,000-2,000 ha. 3) The frequent personnel changes of supervisor of national forest station(the responsible person on-the-spot) obstructs to accomplish the consistent management plan. 4) In the working plan drafting for national forest, basic investigations should be carefully practiced with sufficient expenditure and staff not to draft unreal working plan. 5) The area of working-unit should be decreased to less than 2,000 ha on the average for intensive management and the principle of a working-unit in a forest station should be realized as soon as possible. 6) Reforestation on open land should be completed in a short time with a debt of the special fund(a long term loan), and the land on which growing hardwood stands should be changed with conifers to increase productivity per unit area, and at the same time techical utilization method of hardwood should be developed. 7) Expenses of reforestation should be saved by mechanization and use of chemicals for reforestation and tree nursery operation providing against the lack of labour in future. 8) In forest protection, forest fire damage is enormous in comparison with foreign countries, accordingly prevention system and equipment should be improved, and also the minimum necessary budget should be counted up for establishment and manintenance of fire-lines. 9) Manufacture production should be enlarged to systematize protection, processing and circulation of forest business, and, by doing this, mich benefit is naturally given for rural people. 10) Establishment and arrangement of forest road networks and erosion control work are indispensable for the future development of national forest itself and local development. Therefore, these works should be promoted by the responsibility of general accounting instead of special accounting. 11) Mechanization of forest works should be realized for exploiting hinterlands to meet the demand for timber increased and for solving lack of labour, consequently it should promote import of forest machines, home production, training for operaters and careful adminitration. 12) Situation of labour in future will grow worse. Therefore, the countermeasure to maintain forest labourers and pay attention to public welfare facilities and works should be considered. 13) Although the condition of income and expenditure grows worse because of economical change, the regular expenditure should be fixed. So part of the surplus fund, as of the end of 1971, should be established for the fund, and used for enlarging reforestation and forest road networks(preceding investment in national forest).

• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.166-184
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• 1979

In order to prevent the water loss in the irrigation canal constructed on the sandy gravel layer or on the other highly permeable ground layer, lining has been practiced. Many studies have been done so far on the lining method to prevent the water loss in the irrigation canal and recently studies on the lining with plastic film or polyethylene film were also reported. However, the plastic film or polyethylene film has low strength and is liable to break, and water loss from pin hole caused by contacting with sand or gravel is highly predicted. This study was then conducted to find proper lining and buring method in canal construction of polypropylene mat after coated with vinyl, as one way to overcome the shortcoming frequently observed when plastic or usual polyehtylene film were used. Eventhough rather longer periods of experiments are needed to attain reliable and accurate results on the variation of durability, the durability of asphalt coated area, or on the damage due to freeze after burial or exposure of polypropylene mat, the experiemental results obtained during one year of period are summarized as follows: 1. The curvature at the area between canal bottom and side slope had increased stability and saved consruction cost. The relationship among the variation of curvature, the reduction of polypropylene mat and the reduced amount of soil cutting at each side slope was presented in Fig. 7 through 9. 2. The depth of covering material to protect polypropylene mat was desired to be over 30cm, considering the water depth, side slope, canal cleaning practices, traffic, or back pressure of irrigation period. 3. In order to increase the canal stability and to prevent slope erosion, sandy soil was required, to be placed under ground, and coarse gravel should cover the surface area of canal. 4. The studies on the stability of side slope in the canal should consider the passive area on the bottom and the slope should be about 1 to 2, considering the slope stability, allowable velocity and tractive force. 5. When compared with earth lining, the lining with polypropylene mat coated with vinyl was responsible to save 28% and 37% of canal lining cost, when the soil carrying distances were 500 and 700m. respectively. 6. The water interception was almost completely attained when the polypropylene mat coated with vinyl was used for lining. But further studies were assumed to be necessary for the use of asphalt since the strength of polypropylene mat connected with asphalt will vary with duration.