• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.292-298
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• 2007

In order to thoroughly understand change patterns and to set up an appropriate approach the direction of future treatment towards children in Chonbuk area, we carried out this research. we could draw below conclusions from the studies based on researches of distribution of new patients visited Dept. of Pediatric Dentistry, Chonbuk Nat' university from 1998 to 2005 and current changes in dental treatment. 1. There was an increase in the number of patients until 2004 but it decreased in 2005. Boys took higher portion. 2. Number of patients increased during school holidays. 3. 97.7% of patients were urbanites. 4. An age group from 31 months to 6 years showing 48.2% was the highest, each percentage of $7{\sim}13$ years, $13{\sim}30$ months showed 31.3%, 17.2%. 5. 33.8% of patients were referred from local dental clinics and among them, an age group from 31 months to 6 years showing 49.5% was the highest, each percentage of $7{\sim}13$ years, $13{\sim}30$ months showed 35.2%, 12.9%. 6, 5.5% of patients who had systemic diseases, among them, each percentage of cardiovascular disease, mental retardation, respiratory disease showed 21.8%, 13.6%, and 11.0%. 7. According to the distribution of chief complaints, dental caries showing 42.9% was the highest. 8. Root canal treatment, restoration, prosthesis showing 42.6% were the highest of all treatments.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.239-246
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• 1995

This research aimed at the contribution to obtaining the scientifical data which were required for planning she environmentally sound and sustainable management, particularly in the field of the logging road construction. Main natural environmental variables including natural vegetation, rainfall, soil runoff were measured in the logging road on-sites and analysed. This project was carried out at the (mt.)Paekunsan Research sorest of Seoul National University, located in Gwangyang, Chollanam-do in southern part of Korea, from 1993 to 1994. 1. The explanatory variables for erosion and sedimentation on logging road surface were accumulated rainfall, erosion distance, cross-sectional gradient, and soil hardness. The erosion and sedimentation on logging road was increasing positively in proportion to the accumulated rainfall, soil distance from starting point of the logging road, and cross-sectional gradient. 2. On cut-slope of logging road, cut-slope shape, part of the slope, plant coverage, soil hardness, sand content, accumulated rainfall, clay content, and silt content were effective factors. Cut-slope erosion and sedimentation on logging roam increased as with the lower plant coverage, the lower accumulated rainfall, the high sand content in the soil. 3. On fill-slope of logging road, there were three significant variables such as total rainfall and number of rainfall-storm. Fill-slope erosion and sedimentation had a positive correlation with the amount of rainfall, the number of rainfall, the soil hardness. 4. The total erosion and sedimentation on logging road were $5.04{\times}10^{-2}m^2/m^2$ in logging road construction year, $7.37{\times}10^{-2}m^2/m^2$ in next year. The erosion and sedimentation on logging road surface were 32.7% of total erosion and sedimentation on Logging road in construction year, and 57.1% in next year, respectively. The erosion and sedimentation on cut-slopes were 30.4% on logging road in construction year, fill-slopes of total erosion and sedimentation and 21.0% in next year, respectively. The erosion and sedimentation on fill-slopes were 36.9% on logging road in construction year, 21.9 in next year. To decrease the erosion and sedimentation at the logging road from the beginning stage of construction, the effective revegetation works should be implemented on the cut-slope and fill slopes, and erosion control measures such as optima. road design must be constructed on read surface.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.308-316
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• 2015

This study was conducted to investigate the situation of ICT apply to plastic greenhouse, and the results be apply to design of new one. A CFD analysis were conducted to monitering the ventilation and energy saving of the single span greenhouse newly designed. The causes of delay to apply ICT to plastic greenhouse are the high cost for installation(24%), insufficiency of after services(19%), often disorder(16%), unskillful management of soft ware(15%), insufficient ICT efficiency(13%) and unsatisfying of income increase(12%). The parts of problem occurred in ICT plastic greenhouse are the structure, actuator, environmental control system and sensor(approximate 14%, respectively), remote control technique(13%), plant management technique(12%), energy saving technique(10%) and utilization of software(8%). In the condition of lateral window closed, the average wind speed changed to slow, but it was faster in the condition of leeward side window opened than in the condition of lee and winward side window opened. The air movement in the condition of lateral window closed occur by air moving fan not by out air. It is not affect the room temperature but effective the uniformity of room temperature. The average temperature of low height greenhouse was uniform than high height one. The average temperature in condition of 3rd curtain opened become same with outside temperature after 2 hours, but take more 5 hours in condition of 3rd curtain closed.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.116-123
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• 2008

This study was carried out to investigate into the effect of light-emitting diode (LED) for the light quality as a light source on the broccoli seed germination and the physiological activity of vegetable sprouts. We have also germinated seeds of the broccoli and applied LED as a light quality such as blue, green, red, white, yellow and red + blue color lights to their sprouts for 14 hours and kept dark for 10 hours at the temperature of $25^{\circ}C$ (day)/$18^{\circ}C$ (night). Broccoli sprouts were extracted by methanol and their physiological activities were examined. All broccoli seeds were germinated at 3 days after seeding regardless of the light color. Total sprout fresh weight were mostly became highest by 0.389g (10 plants) at 8 days after seeding when their sprouts were grown under blue color light. Total phenol compound contents in broccoli sprouts were extremely increased by $83.0\;mg{\cdot}L^{-1}$ under the white light, and total flavonoid contents were most much more by $72.6\;mg{\cdot}L^{-1}$ under the blue light. DPPH radical scavenging activity at $2,000\;mg{\cdot}L^{-1}$ were most highest by 93.5% in broccoli sprouts grown under the white light. Nitrite radical scavenging activity at the concentration of $500\;mg{\cdot}L^{-1}$ in sprout extracts were the most increased by 66.9% under the yellow light, and tyrosinase inhibition activity at $2,000\;mg{\cdot}L^{-1}$ in sprout extracts were by 14.5% under red light.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.361-367
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• 2017

Production cost as well as environmental contamination can be reduced by reuse of drained nutrient solution in hydroponic. This research was conducted to obtain the information in changes in inorganic elements concentration of supplied and drained nutrient solution as well as of plant leaves. To achieve the objective, the samples of supplied and drained solution and cherry tomato leaf tissues were periodically collected and analyzed during the hydroponic cultivation. The electrical conductivity (EC) of supplied and drained nutrient solution in early growth stage of cherry tomato were measured as around $2.0dS{\cdot}m^{-1}$, but those values move up with the passage of time reaching to $2.0dS{\cdot}m^{-1}$ at flowering stage of 9th fruiting node. The pHs of drained solution in early growth stage were 6.4 to 6.7, however those showed a tendency to get lowered to 5.9 to 6.1 as time passed during the crop cultivation. The concentration differences of $NO_3-N$, P, K, Ca, and Mg between supplied and drained solution were not distinctive until flowering stages of 4th fruiting nodes, while those in drained solution moved up after the stage. The tissue N contents of leaves decrease gradually and those of K and Ca increased as crops grew. However, Tissue P and Mg contents were maintained similarly from transplant to end-crop. The above results would be used in correction of drained nutrient solution when element compositions are varied compared to supplied solution in hydroponic cultivation of tomatoes.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.358-372
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• 1987

This study was performed to obtain data which can be applied to use of water-proof mortars. The data was based on the properties of water-proof mortars depending upon various mixing ratios to compare those of cement mortar. The water-proof agents used were retard and accelerate type which are being used as mortar structures. The water-proof agents, mixing ratios of cement to fine aggregate were 1:1, 1:2, 1:3 and 1:4. The results obtained were summarised as follows; 1. The results of flow test, water-cement ratio was increased with the increasing of mixing ratio. 2. The permeability were increased in poorer mixing ratio and higher water pressure. 3. The bulk density was decreased with the increasing of mixing ratio, and compressive and tensile strength were increased with increasing of the bulk density. 4. At 1:1 mixing ratio, the highest strengths were showed and strengths were decreased with the increasing of mixing ratio. 5. The absorption rates were increased in- poorer mixing ratio 6. The correlation between W/C, permeability, bulk density, compressive strength and absorption rate were highly significant as a straight line, respectively.

• Korean Journal of Agricultural Science
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• v.31 no.1
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• pp.15-25
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• 2004

In order to determine the effect of fermentation by the mycelia of fungal species, Formitella fraxinea and Sarcodon aspratus, on the in vitro dry matter digestibility and pH of mixtures with sawdust plus 20% wheat bran w/w, on dry matter basis to use as a feedstuff or an additive including fungal mycelium into a feedstuff. The mixtures were unfermented (UF) and fermented by Formitella fraxinea(FF) and Sarcodon aspratus(SA) for two weeks at $29^{\circ}C$ in a incubator. Fungal fermentation products were added to the basal diet to the level of 0, 1, 3 and 5%, w/w of diets each. The in vitro dry matter digestibilities, soluble sugar contents and pH of fermentation fluids were measured at 24, 48 and 72hr after fermentation begin. Neutral detergent fiber(NDF) contents in mixtures were lower for SA and UF(80.4 and 82.2%) than for FF(88.3%) (P<0.05). In vitro DM digestibility for 48h was higer for SA(21.2%) than for UF and FF(17.9 and 12.2%). The in vitro dry matter digestibility for 24hr was higher for diets added with FF 1% as 49.18%, and lower for diet added with FF 5%(43.07%) than basal diet(44.98%)(P<0.05), and tended to be higher for the diets added with fungal products. The pH of in vitro fermentation fluids for 24 and 48 hrs fermentation were lower for diets added with all FF and SA than for UF(P<0.05). However, those for 72 hrs fermentation were higher for SA 1%(6.74) than other diets(P<0.05). The soluble sugar concentration of in vitro fermentation fluid was not different between diets for 24 hr fermentation. However, those were higher for all additive diets than basal diet for 48 and 72 hrs fermentation(P<0.05). It could be concluded that dairy cow's diets added with fungal fermentation products have positive effects, and expected it will be more beneficial if more fungal mycelium was contained.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.762-770
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• 2016

This study intended to investigate environmental factors including soil and vegetation in order to understand the environmental and ecological characteristics of the Korean endemic species, Syringa fauriei. Syringa fauriei is mainly distributed along the valley and riverside of the Gangwondo and its population is located at an elevation of 121~520m. Consequent to a vegetation survey within natural populations, a total of 320 taxa were identified from 20 quadrates in 4 natural populations. The Syringa fauriei population was classified into Securinega suffruticosa dominant population, Acer pseudosieboldianum dominant population, Amorpha fruticosa dominant population and Sorbaria sorbifolia var. stellipila dominant population. According to the physical and chemical soil analysis, Syringa fauriei habitats contained 1.98~2.81% of organic matter and 0.13~0.20 mg/kg of total nitrogen. The concentrations of cation exchange capacities $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were $0.10{\sim}0.33cmol^+/kg$, $3.44{\sim}20.53cmol^+/kg$, and $0.34{\sim}0.95cmol^+/kg$, respectively. Positive ion substitution capacity was $8.08{\sim}13.68cmol^+/kg$. The pH was 6.28~7.74. The importance value of Deutzia glabrata, Fraxinus rhynchophylla, Alangium platanifolium var. trilobum, Syringa fauriei, Juglans mandshurica, and Salix koreensis in the Syringa fauriei population were 86.99%, 43.97%, 23.01%,18.52, 18.40%, and 11.56%, respectively. Correlation analysis between the vegetation of Syringa fauriei populations and its environmental factors using DCCA revealed that the altitude above sea level and $Mg^{2+}$ were the most influential factors, while dominant populations of Securinega suffruticosa and Acer pseudosieboldianum were spread across areas with high percentages of pH, CEC, and $Mg^{2+}$. Acer pseudosieboldianum population was dispersed in areas with higher $K^+$ compared to Securinega suffruticosa population. The dominant population of Amorpha fruticosa was found to live in places with high altitudes above sea level and with high rates of available phosphate, $K^+$, and rock-exposure.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.273-282
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• 2012

This study has estimated Gyeongju National Park's natural environment and cultural relic value in the same way and then been performed to compare the size of the value. Representative method to measure environmental property is contingent valuation methods, CVM. The variables and estimated models adopted for the calculation were same and the respondents were asked by distinguishing between the amount which they would pay to preserve the natural environment and that which they were willing to pay to preserve the cultural relics. As the result, WTP(Willing to pay), the amount that they were willing to pay to preserve the natural environment of Gyeongju National Park was 17,838 won per person and that to preserve the cultural relics appeared to be 316,248 won per person. Based on this, it was estimated that the value of the natural environment with which Gyeongju National Park provided annual visitors was 47 billion won and that the annual value of the cultural relics was 845.7 billion. If the natural environment and the cultural relics value elements are united, it can be estimated that the natural environment and cultural relic value got at the time of people's first visit to Gyeongju National Park is 334,086 won and that the annual value is 893.4 billion won. In this study, the value of the cultural relics has been estimated 18 times higher than that of the natural environment. This reason was that visitors judged that a total of 66 cultural properties including 11 national treasures, 23 treasures, 13 historic places, one historic sites and scenic spot and 18 local cultural properties, etc. which were distributed in Gyeongju National Park were worth far more than the natural environment. Based on the result of this study, the operating management plan of Gyeongju National Park should include a differentiated operation strategy through consultation with relevant experts by taking into account characteristics of the physical components.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.718-732
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• 2013

The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Geumdangsil Pine Forest of Yecheon designated as Natural Monument No. 469. Furthermore, this paper suggest efficient sustainable forest preservation and using. In order to achieve the sustainable forest preservation, this study was to analyse topography, land use, tree growth, soil environment, forest usage and forest management, etc. According to analysis the results, the site area is located in the flatlands where is from 130 to 140 m above sea level. The around forest was transformed into agricultural land. The 565 individuals of Pinus densiflora grows in the forest, whereas, 25 trees was cut down or died. There are signs of 25 stumps. The most of 565 trees' diameter at breast height(DBH) was centerized between 30 cm and 50 cm, moreover, the average life expectancy of trees were 85.4 years. The oldest age of tree was estimated to be 200 years. The Sample trees of rate of branch growth is from 4.3 cm to 5.1 cm per year. The middle branch which is more vigorous growth grow 24.2 cm for 3 years. Moreover, the result of soil physico-chemical properties analysis of 7 plots, 4 categories which is soil organic matter, total nitrogen, available phosphoric acid, specific electrical conductance was generally good, however, the 2 categories which is soil pH, exchangeable cation needed improvement. Currently, the site was not pressured by facilities and usage, however, there might be threaten by agriculture such as encroaching on forest. Therefore, there should establish comprehensive ecosystem management such as facility management, visitors management and operation management In this paper considered 4 fields that is ecosystem management, facility management, visitors management and operation management for sustainable management.