• Journal of Korean Society on Water Environment
• /
• v.32 no.2
• /
• pp.135-141
• /
• 2016

This study investigated changes of hydrology, soil characteristics, riparian vegetation communities, and geomorphology in sandbars before and after sand-mining to determine the effect of sand-mining at upstream of Guemgang and Bochungcheon streams in Korea. Sand-mining events affected the mining area. They supplied organic matters and nutrients during flood. Sediment deposition caused soil texture change and expansion of vegetation area. However, riverbeds were stabilized after the disturbance. According to the analyses of aerial photographs, the vegetation area was significantly expanded in both dam-regulated streams and dam-unregulated streams after sand-mining. Willow shrubs advanced in disturbed area at an average of 10 years after sand-mining. It took willows trees 10.6 years to become dominant communities. Therefore, it took a total of 20.6 years for new riparian forest to form in sandbar after sand-mining. Our results confirmed that stream flow condition were dependent on vegetation recruitment in dam-regulated streams and dam-unregulated streams. For willow recruitment in unregulated streams, calculation of water level below dimensionless bed shear stress is important because low water level variation is a limiting factor of vegetation recruitment.

• Journal of agriculture & life science
• /
• v.45 no.3
• /
• pp.19-23
• /
• 2011

In this study three types of domatia; Tuft (T), Pocket-Tuft (PT) and Pocket (P) were observed on some species of the genus Cornus. Cornus officinalis Sieb & Zuee and C. florida Linnaeus possess T type, C. controversa Hemsl and C. walteri Wangerin possess PT type while C. alba Linnaeus possess P type. A total of 120 leaves were investigated for foliar mite's population. T type domatia was the habitat of 329 mites (48.89%), followed by PT type where 198 mites (29.41%) were found, and the least favored was the P type domatia that accommodated 146 mites (21.70%) out of 673 mites in total. The mean number of mites per domatia was $8({\pm}0.22)$, $4({\pm}0.95)$ and $3({\pm}0.70)$ for T, PT and P type, respectively. The alternative hypothesis that foliar mites prefer T type domatia as a habitat than PT and P type domatia was accepted based on these findings at a probability of P<0.05. Thus, it was concluded that foliar mites prefer T type domatia than the other two types. This could be due to the nature and efficiency of T type domatia in ensuring mites protection from predators and unfriendly environmental conditions. Therefore, the presence of denser tufts lowers the risks of predation and unfriendly environmental conditions and results in a higher number of mites.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.153-153
• /
• 2019

Evapotranspiration (ET) is an important component of hydrological processes. Accurate estimates of ET variation are of vital importance for natural hazard adaptation and water resource management. This study first developed a soil water index (SWI)-based Priestley-Taylor algorithm (SWI-PT) based on the enhanced vegetation index (EVI), SWI, net radiation, and temperature. The algorithm was then compared with a modified satellite-based Priestley-Taylor ET model (MS-PT). After examining the performance of the two models at 10 flux tower sites in different land cover types over East Asia and Australia, the daily estimates from the SWI-PT model were closer to observations than those of the MS-PT model in each land cover type. The average correlation coefficient of the SWI-PT model was 0.81, compared with 0.66 in the original MS-PT model. The average value of the root mean square error decreased from $36.46W/m^2$ to $23.37W/m^2$ in the SWI-PT model, which used different variables of soil moisture and vegetation indices to capture soil evaporation and vegetative transpiration, respectively. By using the EVI and SWI, uncertainties involved in optimizing vegetation and water constraints were reduced. The estimated ET from the MS-PT model was most sensitive (to the normalized difference vegetation index (NDVI) in forests) to net radiation ($R_n$) in grassland and cropland. The estimated ET from the SWI-PT model was most sensitive to $R_n$, followed by SWI, air temperature ($T_a$), and the EVI in each land cover type. Overall, the results showed that the MS-PT model estimates of ET in forest and cropland were weak. By replacing the fraction of soil moisture ($f_{sm}$) with the SWI and the NDVI with the EVI, the newly developed SWI-PT model captured soil evaporation and vegetation transpiration more accurately than the MS-PT model.

• Proceedings of the Ginseng society Conference
• /
• 2002.10a
• /
• pp.456-466
• /
• 2002

Wild ginseng production is increasing due to forest recovery for last 30 years. Total number of Symmani (traditional mountain ginseng digger) was 558 in 2001. Provincial distribution of Symmani in 2001 was highest in Kangwon $(32\%),$ next in Choongbook $(21\%)$ and least in Jeonnam $(0.7\%)$ and Kyoungnam $(0.9\%).$ Age distribution of Symmani was $33\%\;for\;fourties,\;32\%$ for fifties and $20\%$ for sixties. There were 8 persons in eighties. Symmanies are still keeping traditional ritual for mountain god serving clothes of colored ribbons and foods. Increased production induced open market system from underground dealing of mountain ginseng. Korea Mountain Ginseng Association established mountain ginseng assessment committee with professional Symmanies in 2001. From September to November in 2001, 987 roots were requested for quality assessment to the committee and 476 roots $(48\%)$ were passed and graded and others were rejected. Highest frequency of rejection was foreign origin. Pass rate was highest $(74\%)$ in Choongnam suggesting best place for quality. Number of collected roots in each province was positively correlated (p=0.05) with number of Symmanies. There are 3 quality groups of mountain ginseng, Heaven (pure natural), Earth (from seeding of wild ginseng) and Man (from seeding or seedling of wild ginseng with slight environmental modification). The relationship between price and age was polynomial in high quality root, Heaven, Earth and seed long head of Man group, and linear in low quality group, seedling long head of Man. The best one in 2001 was 26 g, 124 years old and sold with 109 million won. Quality criteria are age, shape, weight, color and healthy outlook. Fine roots are criteria for health status of roots and taproot is criteria for efficacy and called as medicine barrel. The implication is that ginsenosides have rarely been experienced for efficacy. The quality criteria of cultivated ginseng were originated from those of mountain ginseng. It is unique for mountain ginseng that only fresh one can be on market. Since quality criteria of mountain ginseng must be based on the efficacy experience it is well expected that present criteria might almost be established at the age of Shinnong Materia Medica.

• Korean Journal of Plant Taxonomy
• /
• v.46 no.4
• /
• pp.392-404
• /
• 2016

The anatomical characters of the 19 taxa of Korean Juncus were reviewed in order to examine their significance in taxonomy. Cross-section analyses were conducted on the stem, leaf, and capsule. Descriptions, line drawings, tables, and a species key of Korean Juncus are provided for species identification based on anatomical characters. The results of this study showed that the arrangements of the vascular bundle, fiber, and air-space structure in the stems as well as the arrangements of the vascular bundle and parenchyma in the leaves and the development of placenta in capsules are the key characters to be used when classifying each species of Juncus. It was revealed that the studied anatomical features were more useful for identification at the subgenera and section levels than at the species level. Therefore, these anatomical characters used in conjunction with external morphological features will make a valuable contribution to establishing a natural classification system for Juncus.

• Korean Journal of Plant Taxonomy
• /
• v.46 no.4
• /
• pp.348-355
• /
• 2016

We report previously unrecognized flowering plants of Lao PDR found during a botanical survey of Lao PDR in 2015-2016. We found Phyllagathis tuberosa (C. Hansen) Cellinese & S. S. Renner (Melastomataceae) and Tolypanthus pustulatus Barlow (Loranthaceae) in the Phou Khao Khouay National Biodiversity Conservation Area (PKKNBCA), previously only known from type localities in Thailand. This is the first report of Phyllagathis tuberosa and the genus Tolypanthus in the Lao PDR. We also found Lonicera bournei Hemsl. (Caprifoliaceae) in the proposed Phosabous National Protected Area (PNPA) of Xiangkhoang, neglected with regard to the flora of Laos since its initial report in early 20th century. The current report will augment our understanding of the floristic relationships among SE Asian countries and will help elucidate the biodiversity of Lao PDR.

• Korean Journal of Plant Resources
• /
• v.28 no.2
• /
• pp.217-234
• /
• 2015

The ethnobotanical study was conducted to record and conserve the traditional knowledge of botanical taxa in Jeju island, Korea from March to November, 2011. According to the survey results, derived from 1,774 sheets of 177 residents at 78 places, the ethnobotanical plants in Jeju island consisted of a total 356 taxa; 103 families, 260 genera, 312 species, 2 subspecies, 37 varieties and 5 form. The analysis of usage for 365 taxa showed that the medicinal use was the highest with 284 taxa, followed by edible with 145 taxa, ritual with 36 taxa, craft with 31 taxa and timber with 31 taxa respectively. The leaf of plant was the most useful part, followed by stem and whole plant. The most frequently mentioned taxon was Plantago asiatica (34 citations), followed by Artemisia princeps (32 citations) and Lonicera japonica (30 citations).

• Korean Journal of Pharmacognosy
• /
• v.50 no.2
• /
• pp.141-147
• /
• 2019

The aim of this study was to investigate the potential of Acanthopanax sieboldianum (Makino) Koidz (ACS) as a potent antioxidant and antidiabetic agent. The antioxidative and alpha-glucosidase inhibitory activities were examined using the methanol extracts and solvent fractions from ACS-leaf and ACS-stem. Antioxidative activities were measured by in vitro methods such as DPPH and ABTS radical scavenging activity and superoxide dismutase (SOD) activity. When the chloroform and ethyl acetate fractions of ACS-leaf and ethyl acetate fractions of ACS-stem were compared with the control, the SOD-like activity was impaired even at the low treatment concentrations. In addition, the ethyl acetate fractions of ACS-leaf and ACS-stem showed alpha-glucosidase inhibition activities at low treatment concentrations. Analysis of the major components in the fractions of ACS-leaf and ACS-stem was also performed using HPLC. Finally, astragalin, isoqurecetin, chlorogenic acid and caffeic acid contents were measured. Based on this work, we propose that ACS-leaf and ACS-stem have great potential as natural antioxidant and antidiabetic materials related to health benefits.

• Journal of Platform Technology
• /
• v.6 no.4
• /
• pp.78-86
• /
• 2018

In this paper, a VR-based cyber hiking system was designed to provide virtual reality for famous mountains that can offer the real senses and feelings of hiking in supporting environmental factors of actual mountains such as the temperature, air, sound, echoes, etc., of the mountain the user wants to climb. The VR-based cyber hiking system that reflects real-time site conditions is largely consisted of the data collection module that collects data from the live site, multiple drive modules that enables the user to feel real senses using data from the sites, and sensor module to detect the stimuli provided by the drive modules and the user's physical body transition. Unlike existing VR-based hiking systems, the proposed cyber hiking system not only provides simple virtual reality for the wanted mountain, but can also provide the natural conditions of real mountains and implement the uphill and downhill of hiking routes. In particular, it has the effect of providing fun and game elements to users by excluding unnecessary conditions and risks that may arise in actual hiking and instead supporting augmented realities such as squirrels on actual hiking paths. In addition, in providing users with the changes in their body before and after hiking, it is expected to be effective in providing diverse feedback such as the height, gradient, and speed of mountain hiking.

• Journal of the Korean Data Analysis Society
• /
• v.20 no.6
• /
• pp.2953-2966
• /
• 2018

Housing prices are closely related to various variables that indicate macroeconomic conditions. In this paper, empirical analysis based on data is performed referring to previous studies. Focusing on the policy interest rate among the factors affecting the housing price, the non-linear impulse responses of other variables to the interest rate shock are analyzed. Using the random forest algorithm, the variable importance scores of the macroeconomic variables presented in the previous studies are calculated. After selecting the variables through this process, the impulse responses are calculated using a model that can capture non-linearity. According to the model, the responses of housing prices to the policy rate is only significant when the rate is raised. Especially, the impulse response is amplified when the shock increases due to the non-linear characteristics that can not be captured by the traditional VAR methodology. The analysis results suggest that the interest rate as a policy instrument should be approached from a more cautious perspective.