• Journal of Korean Society of Forest Science
• /
• v.82 no.2
• /
• pp.188-194
• /
• 1993

A natural Quercus variabilis forest and a Populus alba${\times}$P. glandulosa plantation in Mt. Mohu area were studied to investigate aboveground biomass and net production. A $20m{\times}30m$ quadrat was set up in each stand, and 10 sample trees each of Quercus variabilis and Populus alba ${\times}$ P. glandulosa were cut for dimension analysis. There was little difference in accuracy among three biomass regression models of logWt=A+BlogD, $logWt=A+BlogD^2H$, and logWt=A+BlogD+ClogH, where Wt. D, and H were dry weight, DBH, and height, respectively. Aboveground total biomass of Quercus variabilis stand was 31,275kg/ha, and that of Populus alba ${\times}$ P. glandulosa was 55,581kg/ha. In both of Quercus variabilis stand and Populus alba ${\times}$ P. glandulosa stand, the proportion of each tree component to abovegound total biomass was high in order of stem wood, branches, stem bark, and leaves. Quercus variabilis stand was higher in the proportion of stem bark, branches and leaves than Populus alba ${\times}$ P. glandulosa stand, while the former was lower in that of stem wood than the latter. Aboveground total net production of Quercus variabilis stand was 4,267kg/ha/yr., and that of Populus alba ${\times}$ P. glandulosa stand was 3,903kg/ha/yr. The proportion of each tree component to aboveground total net production of Quercus variabilis stand was high in order of leaves, stem wood, branches, and stem bark. That of Populus alba ${\times}$ P. glandulosa stand was high in order of stem wood, leaves, branches, and stem bark. Net assimilation rate and efficiency of leaf to produce stem of Quercus variabilis stand were 2.121 and 0.840, respectively. Those of Populus alba ${\times}$ P. glandulosa stand were 3.376 and 2.085, respectively. Though Populus alba${\times}$P. glandulosa stand was lower in aboveground total net production than Quercus variabilis stand, the former was higher in aboveground total biomass than the latter. The reason was that Populus alba${\times}$P. glandulosa stand was higher in net production of stem wood of accumulation organs than Quercus variablis stand.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.32 no.3
• /
• pp.1-9
• /
• 2014

This article is the results of excavation data and it aims to interpret the composition facilities of the Royal garden at the Wanggung-ri site. The base of research was prepared through excavation and study on the royal garden at the Wanggung-ri site, which was constructed in Sa-bi period of Baek-je. The elements for the royal garden at the Wanggung-ri site were divided in 3 parts. - 1) Stonework facility 2) Installation for conveyance of water : Large moat-shaped ditch and Winding waterway(1~6 and water catchment) 3) Square cornerstone building. In this article, I arrange the basic data about facilities and function of the royal garden for making recovery of original form. First of all, I reason that stonework facilities were in charge to make space for catchment and boundary. Especially the Round angel rectangular stonework facility took charge of complex roles as catchment and water conveyance, and water can be transferred to the large moat-shaped ditch through joint between them. I confirmed that the round angel rectangular stonework facility and the large moat-shaped ditch which were connected by joint are one of the facilities in the royal garden. The large moat-shaped ditch protected the eastern, the northern walls and workshop site under the inclined plane to minimize the damage. Also, the large moat-shaped ditch took several roles, especially water catchments and landscaping. The large moat-shaped ditch was continually used from the period of Baek-je to the unified Silla, as a result it was completely deposited inside. After that, the 6 winding waterway were built in the western inclined plane with similar needs with the large moat-shaped ditch, and the square cornerstone building was built in same time. I noticed that the square cornerstone building was built as a part of the royal garden in Sa-bi period of Baek-je through the remains of Baek-je tiles around the building. After that, the square cornerstone building was built in same place as reconstruction.

• Journal of Korean Society of Forest Science
• /
• v.95 no.1
• /
• pp.102-112
• /
• 2006

The change of species composition and stand structure along altitudinal gradients in different aged stands was studied in five natural stands located each at 400 m, 800 m, 1,000 m, and two at 1,300 m above sea level (asl) in the western part of Mt. Chiri in Korea. Trees larger than 2.5 cm DBH were inventoried in 3 to 8 $20m{\times}20m$ quadrats in each study site. Stand ages were estimated based on the ages of Pinus densiflora Siebold & Zucc. and Abies koreana Wilson, and used to analyze the changes in species composition and stand structure including diameter and height distributions. Species composition was changed along altitudinal gradients as P. densiflora dominated stands at 400 m asl while A. koreana dominated stands at 1,300 m asl. Major species of Quercus also changed along altitudinal gradients as Quercus variabilis Blume at 400 m asl, Quercus serrata Thunb. ex Murray at 800 m asl, and Quercus mongolica Fisch. ex Ledeb. at higher than 1,000 m asl. The diameter distribution did not show significant differences among stands of different altitudes. However, the height distributions of upper crown layers were significantly different among stands at below and above 1,000 m as) (P < 0.0001). Trees taller than 20 m rarely appeared in stands over 1,000 m asl. P. densiflora dominant stands at 400 m asl developed two clumped age groups as one in 30-40 ages and the other around 70 years old. Q. serrata dominant stands at 800 m asl, Q. mongolica dominant stands at 1,300 m asl and A. koreana dominant stands at 1,300 m asl were estimated to be around 30, 70, and over 140 years old after major disturbances, respectively. The diameter distribution with age structure indicated that P. densiflora at 1,300 m asl might be replaced by Q. mongolica, and Q. mongolica might be replaced by A. koreana and Pinus koraiensis later. A. koreana dominant stand seemed to stay its dominance quite long if the large disturbance would be absent.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.6
• /
• pp.586-593
• /
• 1985

The rose bitterling, Rhodeus ocellatus (KNER) is commonly distributed in the fresh waters of Korea and Japan. On January 15, February 15, and March 18 in 1984, mature adults of rose bitterling were caught in the watercourse of Maeri, Kimhae, South Korea. The authors fertilized the eggs employing dry method in the laboratory on May 7, 16 and 25 in 1984. Hatched larvae were reared in small aquariums at $17{\sim}25.5^{\circ}C$ (average around $21.2^{\circ}C$). Mollusks, Anodonta woodiana in the gill chamber of which, rose bitterling lay eggs were caught in order to study natural spawning of the rose bitterling in the same watercourse. The eggs of this species are not adhesive and demersal. The size of the eggs varies from 2.54 to 2.75mm in long diameter and 1.45 to 1.65mm in short diameter. The eggs are cylindrical in form when they are extruded from ovipositor, immediately after entering water, but they acquire their distinctive form of a greatly elongated pear. Hatching took place in ca. 39 hours after fertilization. The newly hatched larvae were $2.65{\sim}2.70mm$ in total length possessing yolk sac and 13-14 myotomes. Thirteen days after hatching, the prelarvae attained 6.5 mm in total length, and the first melanophores appeared on the head, and the anterior part and sides of the yolk sac. One month after hatching, the postlarvae attained 8.5mm. in total length and emerged from the gills of the mollusks. Then the yolk sac was completely resorbed. Two months after hatching, the rose bitterling attained 14.4mm in total length, and entered the fingerling period of life. All the rays already present were the D. III, 11-12, A. III, 11-12, P. 10, V. 7. and a distinguishing, feature is the presence of a black pigment spot in the lobe of the dorsal fin.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.1 no.1 s.1
• /
• pp.139-155
• /
• 2001

We investigate the vertical velocity models beneath the newly installed broadband seismic network of KMA (Korea Meteorological Administration) by using receiver function inversion technique. The seismic phases are primarily P-to-S conversions and reverberations generated at the two highest impedance interfaces like the Moho (crust-mantle boundary) and the sediment-basement contact. We obtained the teleseismic P-wave receiver functions, which were derived from teleseismic records of Seoul (SEO), Inchon (INCN), Tejeon (TEJ) , Sosan (SOS/SES), Kangnung (KAN), Ulchin (ULC/ULJ), Taegu (TAG), Pusan (PUS), and Ullung-do (ULL) stations. For Kwangju (KWA/KWJ) and Chunchon (CHU) stations, the Moho conversion Ps arrivals and waveforms of radial receiver functions are azimuthally inconsistent and unclear. From the receiver function inversion result, we found that crustal thickness is 29 km at INCN, SEO, and SOS (SES) stations, 28 km at KAN station in the Kyonggi Massif, 32 km at TEJ station in Okchon Folded Belt, 34 km at TAG, 33 km at PUS station in the Kyongsang Basin, 32 km at KWJ station (readjusted station by prior KWA station) included in the Youngdong-Kwangju Depression Zone, 28 km at ULC station in the eastern margin of the Ryongnam Massif, and 17 km at ULL station in the Ullung Island of the East Sea, respectively. The Moho configuration of INCN, SOS, KWJ, and KAN stations show a laminated smooth transition zone with a 3-5 km thick. The upper crusts(${\sim}5km$) of KAN, ULC, and PUS stations show complex structures with a high velocity. The unusually thick crusts are found at the TAG and PUS stations in the Kyongsang Basin compared to the thin (29-32 km) crust of the western part (INCN, SEO, SOS, TEJ, and KWA stations) The crustal thickness beneath Ullung Island (ULL station) shows the suboceanic crust with about 17 km thickness and complex with a high velocity layer of the upper crust, and the amplitudes of Incoming Ps waves from the western direction are relatively large compared to those from othor directions.

• Journal of the Society of Disaster Information
• /
• v.11 no.1
• /
• pp.135-147
• /
• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Korean Journal of Environmental Biology
• /
• v.30 no.2
• /
• pp.90-97
• /
• 2012

Environmental characteristics and vegetation of the natural habitats of Eranthis byunsanensis B.Y. Sun were investigated in order to provide the basic data for conservation, restoration, and utilization of this Korean endemic plant. This study was conducted in Anyang, Byeonsan, Geoje, Gyeongju, Jeju, Ulsan and Yeosu. E. byunsanensis was distributed around the altitudes of 84~585 m with a slope degree of $10{\sim}20^{\circ}$, and mostly formed discontinuous populations in north-east part of valleys. Soil analysis showed the mean organic matter of 9.6% and a slightly acidic pH (mean pH of 4.9). The mean gravimetric water content was 16.5%. Correlation coefficients between environmental factors and community characteristics suggested that there was a positive correlation between slope degree and soil water content, between slope degree and soil pH, between soil organic matter and importance value, and between species richness or evenness and species diversity. The vascular plants from 59 quadrats of 7 habitats were identified into 144 taxa. A few species were dominants and similarly distributed in Byeonsan, Jeju, Ulsan and Yeosu. The highest species diversity was found in Geoje (1.43), while Anyang showed the lowest (0.87). Species evenness of Gyeongju and Jeju was bigger than 0.8, but that of Geoje was the lowest (0.59). Dominant species of woody plants in and around the 59 plots were represented by high frequency of Acer pictum subsp. mono, Carpinus cordata, Lindera obtusiloba, and Carpinus laxiflora. The results of this study can provide useful data for conservation and restoration of natural habitats of Korean endemic Eranthis byunsanensis and for the development and growth of this species for ornamental purposes.

• Journal of the Korean Society of Radiology
• /
• v.14 no.1
• /
• pp.15-22
• /
• 2020

PET(Positron Emission Tomography) devices are used as PET/CT or PET/MRI devices fused with the devices of CT or MRI for obtaining anatomical information. Therefore, the devices are constructed in circular ring-type structure whose length of gantry(the main part of filming) becomes wider and the interior depth becomes longer in comparison to other common medical equipments. scintillator, one of the components in PET devices, is inside the gantry, and as it is consisted of crystal which is sensitive to the change of temperature and humidity, large temperature change can cause the scintillator to be damaged. Though scintillator located inside the gantry maintains temperature and humidity with a thermo-hygrostat, changes in temperature and humidity are expected due to structural reasons. The output value was measured by dividing the inside of the gantry of the PET/CT device into six zones, each of which an Adafruit BME 280 temperature and humidity sensor was placed at. A thermo-hygrostat keeps the temperature and humidity constant in the PET/CT room. As the measured value of temperature and humidity of the sensor was obtained, the measured value of temperature and humidity appeared in the thermohygrostat was taken at the same time. Comparing the average measured values of temperature and humidity measured at each six zones with the average values of the thermo-hygrostat results in a difference of 2.71℃ in temperature and 21.5% in humidity. The measured temperature and humidity of PET Gantry is out of domestic quality control range. According to the results of the study, if there is continuous change in temperature and humidity in the future, the aging of the scintillator mounted in the PET Gantry is expected to be aging, so it is necessary to find a way to properly maintain the temperature and humidity inside the Gantry structure.

• Economic and Environmental Geology
• /
• v.43 no.4
• /
• pp.305-314
• /
• 2010

The stabilization process using limestone ($CaCO_3$) and steel making slag as the immobilization amendments was investigated for As contaminated farmland soils around Chonam abandoned mine, Korea. Batch and continuous column experiments were performed to quantify As-immobilization efficiency in soil and the analyses using XRD and SEM/EDS for secondary minerals precipitated in soil were also conducted to understand the mechanism of Asimmobilization by the amendments. For the batch experiment, with 3% of limestone and steel making slag, leaching concentration of As from the contaminated soil decreased by 62% and 52% respectively, compared to that without the amendment. When the mixed amendment (2% of limestone and 1% of steel making slag) was used, As concentration in the effluent solution decreased by 72%, showing that the mixed of limestone and steel making slag has a great capability to immobilize As in the soil. For the continuous column experiments without the amendment, As concentration from the effluent of the column ranged from 50 to $80\;{\mu}g/L$. However, with 2% limestone and 1% steel making slag, more than 80% diminution of As leaching concentration occurred within 1 year and maintained mostly below $10\;{\mu}g/L$. Results from XRD and SEM/EDS analysis for the secondary minerals created from the reaction of the amendments with $As^{+3}$ (arsenite) investigated that portlandite ($Ca(OH)_2$), calcium-arsenite (Ca-As-O) and calcite ($CaCO_3$) were main secondary minerals and the distinct As peaks in the EDS spectra of the secondary minerals can be observed. These findings suggest that the co-precipitation might be the major mechanisms to immobilize As in the soil medium with limestone and steel making slag.

• Economic and Environmental Geology
• /
• v.51 no.1
• /
• pp.67-76
• /
• 2018

This study reviews three eco-friendly energy towns with hybrid thermal energy supply systems and borehole thermal energy storage (BTES) in Canada and Denmark. The district heating and cooling systems were designed by using multi-source energy for the higher efficiency and reliability as well as environment. ADEU (Alexandra District Energy Utility) located at the developing area in the city of Richmond, Canada was designed to supply district energy with the installation of 726 borehole heat exchangers (BHEs) and a backup boiler using natural gas. DLSC (Drake Landing Solar Community) located in the town of Okotoks, Canada is a district system to store solar thermal energy underground during the summer season by seasonal BTES with 144 BHEs. Brædstrup Solpark district heating system located in Denmark has been conducted energy supply from multiple energy sources of solar thermal, heat pump, boiler plants and seasonal BTES with 48 BHEs. These systems are designed based on social and economic benefits as well as nature-friendly living space according to the city based energy perspective. Each system has the energy center which distribute the stored thermal energy to each house for heating during the winter season. The BHE depth and ground thermal storage volume are designed by the heating and cooling load as well as the condition of ground water flow and thermophysical properties of the ground. These systems have been proved the reliance and economic benefits by providing consistent energy supply with competitive energy price for many years. In addition, the several expansions of the service area in ADEU and Brædstrup Solpark have been processed based on energy supply master plan. In order to implement this kind of project in our country, the regulation and policy support of government or related federal organization are required. As well as the government have to make a energy management agency associated with long-term supply energy plan.