• Natural Product Sciences
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• v.19 no.4
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• pp.281-285
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• 2013

This study was designed to investigate the nervous sedative effects of green tea. The sedative effect was evaluated by examination of Monoamine oxidases (MAOs) inhibitory activity in vitro in the brain and liver of rat fed on green tea cultivated and harvested from the different regions and periods. It showed that methanol extracts of green tea inhibited significantly the brain MAO-A activity. Especially late harvested green tea extracts showed potential inhibitory activity. The liver MAO-B activity was also inhibited by all of the green tea extracts with strong intensity. This study confirmed that major compounds of green tea such as catechin, epigallocatechin-3-gallate (EGCG) and L-theanine, which were well known for the main bioactive components in the tea plants, were not associated with the MAO inhibitory activities of green tea. These results suggested that a MAO inhibition activity comes from other minor tea components we have to search in the future.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.618-627
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• 2019

An increase in damage to crops and facilities caused by wildlife such as wild boar causes serious social and economic problems to the rural economy in Korea. This study aims to estimate the economic losses incurred to rural households in mountain villages near protected areas in Korea due to the damage to agricultural and forestry production by wildlife. The case of mountain villages located in Toji-myeon, Gurye-gun near the Jirisan National Park was studied as an example. Data were collected by interviewing 84 households across six mountain villages in April and June 2016. The results indicate that the economic losses due to wildlife damage in 2015 were estimated to be 1.65 million KRW per household, which is a total of 138.63 million KRW for the 84 households. Among local products, the most damaged products were chestnut, fern-brake, wild pear, peach, and potato, whereas the most damaged products per production area were sweet potato, peach, corn, and potato. The potential economic losses caused by wildlife damage to agricultural and forestry production in whole Gurye-gun area was estimated to be around 4.0 billion KRW in 2015. However, the municipal government budget for the compensation of wildlife damage was only 0.9 percent of the potential rural economic losses caused by wildlife damage in 2015. The results of our study suggest that the compensation scheme for wildlife damage is inadequate in the respect of social justice. Considering the low financial capacity of the municipalities in mountain areas, the central government should take a progressive responsibility by allocating more financial resources for compensation of economic losses of rural households due to wildlife damage. The equitable and effective governance of wildlife conservation is required for sustainable development of rural communities near protected areas.

• Economic and Environmental Geology
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• v.46 no.4
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• pp.301-312
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• 2013

Landslides are caused by complex interaction among a large number of interrelated factors such as topography, geology, forest and soils. In this study, a comparative study was carried out using fuzzy relationship method and artificial neural network to evaluate landslide susceptibility. For landslide susceptibility mapping, maps of the landslide occurrence locations, slope angle, aspect, curvature, lithology, soil drainage, soil depth, soil texture, forest type, forest age, forest diameter and forest density were constructed from the spatial data sets. In fuzzy relation analysis, the membership values for each category of thematic layers have been determined using the cosine amplitude method. Then the integration of different thematic layers to produce landslide susceptibility map was performed by Cartesian product operation. In artificial neural network analysis, the relative weight values for causative factors were determined by back propagation algorithm. Landslide susceptibility maps prepared by two approaches were validated by ROC(Receiver Operating Characteristic) curve and AUC(Area Under the Curve). Based on the validation results, both approaches show excellent performance to predict the landslide susceptibility but the performance of the artificial neural network was superior in this study area.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.59-65
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• 2004

The present study aims to optimise the process parameters of fish glue and adhesion property through room temperature in terms of curing time and opened assembly time for attaining best adhesion strength to wood (Yellow birch, B. alleghaniensis). The uncured and cured fish glue have been characterised by TGA, DSC, FT-JR. It is observed that with increasing curing time up to 48 H, tensile lap shear strength of adhesive joint of fish glue to wood increases and decreases after 48 H. At 15 min. opened assembly time, lap shear strength increases up to 4833 kgf/cm² and decreases after 15 min.

• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.176-183
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• 2001

Loblolly pine (Pinus taeda L.) is the most economically important timber producing species in the southern United States. Much attention has been given to predicting diameter distributions for the solution of multiple-product yield estimates. The three-parameter Weibull diameter distribution yield prediction systems were developed for loblolly pine plantations. A parameter recovery procedure for the Weibull distribution function based on four percentile equations was applied to develop diameter distribution yield prediction models. Four percentiles (0th, 25th, 50th, 95th) of the cumulative diameter distribution were predicted as a function of quadratic mean diameter. Individual tree height prediction equations were developed for the calculation of yields by diameter class. By using individual tree content prediction equations, expected yield by diameter class can be computed. To reduce rounding-off errors, the Weibull cumulative upper bound limit difference procedure applied in this study shows slightly better results compared with upper and lower bound procedure applied in the past studies. To evaluate this system, the predicted diameter distributions were tested against the observed diameter distributions using the Kolmogorov-Smirnov two sample test at the ${\alpha}$=0.05 level to check if any significant differences existed. Statistically, no significant differences were detected based on the data from 516 evaluation data sets. This diameter distribution yield prediction system will be useful in loblolly pine stand structure modeling, in updating forest inventories, and in evaluating investment opportunities.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.37-45
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• 1979

The purpose of the study was to define the labor change in the moutainous villages, So this study analyzed the mass dram of the population from the mountainous villages created by the unequal development between the first and second under the high economic development and the large difference in the income between city and rural area. The content of the study was (1) the foundation of the production in the survey area (2) labor change in the mountainous villages (3) the supply and the demand of the labor in this area. The date were collected from 118 household of 2 villages (one with a high level of brest product, and the other with a low level of forest products) in Cheon-nam Province through a questionarie. The results of the study were as follows. 1. The mass drain in the mountainous villages started in the middle of 1970's, and the rate of drain has been very rapid and accelerated. 2. The drain of the mountainous village with a low level of forest products is more than that of the mountainous village with a high level of forest products. 3. In the mountainous village with high level of forest products, the specialization in the farmer class has begun and the farmers with a side job are now increasing. 4. Generally the major drain consisted of the young class (16-30 age), and consequently it caused a change in the composition of labor power into old age and women. 5. The character of the forest labor market is how changing from closed to open.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.73-81
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• 2006

This study has the object of deriving schemes for not only securing safety of chestnuts, which is the most important forest product in terms of both production and exportation, to consumers with implementing persistent production of them in harmony with the environment, but also producing environmentally friendly chestnuts that can contribute to the increase of a farm household's income through price differentiation from other chestnuts, which are grown by generally accepted ways. In order to do this, I performed an analysis of the reality and outcome from the management of farm households that produce environmentally friendly chestnuts. The result of the analysis demonstrated some problems such as poor establishment of farming skills in a beginning stage, administrative problems with weeding operations and prevention of blight, difficulty in ensuring distribution channels and high production cost. Therefore, propelling productive expansion of environmentally friendly chestnuts after resolving these problems requires many supports and ideas: establishment and diffusion of farming skill system under the cooperation of civil and government organizations, construction of environmentally friendly INM (Integrated Nutrient Management) and IPM (Integrated Pest Management), creation of production areas for improving productivity, introduction of 'Institution of Income Conservation for Environmentally-Friendly Production' that can help farmers to preserve integrity of income on their switchover to production of environmentally friendly chestnuts from generally-grown chestnuts, and finally strong and persistent promotion of environmentally friendly chestnuts towards existing farmers and consumers.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.967-977
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• 2022

The occurrence and intensity of wildfires are increasing with climate change. Emissions from forest fire smoke are recognized as one of the major causes affecting air quality and the greenhouse effect. The use of satellite product and machine learning is essential for detection of forest fire smoke. Until now, research on forest fire smoke detection has had difficulties due to difficulties in cloud identification and vague standards of boundaries. The purpose of this study is to detect forest fire smoke using Level 1 and Level 2 data of Geostationary Environment Monitoring Spectrometer (GEMS), a Korean environmental satellite sensor, and machine learning. In March 2022, the forest fire in Gangwon-do was selected as a case. Smoke pixel classification modeling was performed by producing wildfire smoke label images and inputting GEMS Level 1 and Level 2 data to the random forest model. In the trained model, the importance of input variables is Aerosol Optical Depth (AOD), 380 nm and 340 nm radiance difference, Ultra-Violet Aerosol Index (UVAI), Visible Aerosol Index (VisAI), Single Scattering Albedo (SSA), formaldehyde (HCHO), nitrogen dioxide (NO₂), 380 nm radiance, and 340 nm radiance were shown in that order. In addition, in the estimation of the forest fire smoke probability (0 ≤ p ≤ 1) for 2,704 pixels, Mean Bias Error (MBE) is -0.002, Mean Absolute Error (MAE) is 0.026, Root Mean Square Error (RMSE) is 0.087, and Correlation Coefficient (CC) showed an accuracy of 0.981.

• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.176-190
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• 1997

Sixty-three isolates of Lentinus edodes obtained from Korea were used to assess the genetic similarity by isozyme polymorphisms and random amplified polymorphic DNA patterns. The activities of esterase, peroxidase and acid phosphatase displayed 10, 7 and 3 distinct isozyme patterns, respectively. By combining the isozyme patterns obtained with the 3 enzymes, every isolate showed its own distinct electrophoretic phenotypes. A distance matrix calculated between all pairs of 63 electrophoretic phenotypes based on the presence or abscence of isozyme bands were analyzed by the group-average method. Results of the cluster analysis assinged the 63 phenotypes into six major groups. In the analysis of random amplified polymorphic DNA patterns, all isolates of Lentinus edodes were devided into five RAPD groups.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.426-434
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• 2009

This study was carried out to derive the most optimal production process for the wood fuels(chip and pellet), by collecting cost data on each procedure through the life cycle assessment approach, and to compare between the profitability and efficiency, from the view points of producers and consumers, irrespectively. The costs accounted in this analysis were based on the opportunity cost. The results show that wood chips are cheaper than wood pellets in production costs. In respect to the process with the lowest production cost, while wood chips should be to crush collected residues into pieces on the spot for merchandizing, wood pellets need to be transported to manufactory for pelletizing. The study findings also include that the profits, which is estimated by subtracting expenses from gained sale revenue, were a bit higher for wood chips than wood pellets. Additionally, the price ratio of wood pellets to wood chips for getting the same caloric value appears to be 1.27. Despite of economic benefits of processing wood chips, there are several problems in practice. For producers, there is a possible increase in not only transportation cost for conveying crushers to the dispersed places, but storage cost due to the lack of the marketplaces in the immediate surroundings. For consumers, on the other hand, there are some challenging issues, such as bulky storage facility requirement, additional labor for fuel supplement, frequent ashes disposal, and decomposition in summer and freezing in winter caused by wood chips' own moisture.