• Journal of the Korean association of regional geographers
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• v.7 no.1
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• pp.83-95
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• 2001

The purpose of this study is to examine that we can estimate land use by land values in 5 great cities. For this purpose, I calculated the percentage that each lot value makes up of the highest land values in the city as a indicator. I think this rate is very useful in the comparative study about many cities. At first, I set up four hypotheses based on my preceding studies. Hypothesis 1, the range of CBD can be estimated as having about 10% of the peak land values. Hypothesis 2, when the peak rate of concentric circle of land values seperated from CBD circle is about 30% of the peak land values, that is sub-CBD. Hypothesis 3, generally, a lot of having about 5% of the peak land values represents residential land commercial land use. Hypothesis 4, a lot of having about 3% of the peak land values represents only residential land use. The data on land values in five great cities were got from public notification on land values(1999) of the Ministry of Construction & Transportation. I selected highest lot values from many standard lot value in each Tong(the minimum administrative unit) in each cities. And I drew land values isopleth. Through that isopleth, I identified CBD cmd sub-CBD. Through the book of public notification on land values, I identified what land use are lots of having over 10%, about 5%, below 3% of the peak land values. As a result, we identified land use can be estimated by the percentage that each lot value makes up of the highest land values in the city. The bigger urban size becomes and the more stable land use becomes, the higher fitness of hypotheses becomes. The lowest degree of fitness about 4 hypotheses among 5 great cities showed in Inchon. Because Inchon lies adjacent to the greatest Seoul. The percentage that showed the lowest degree of fitness is 5% of the highest land values. The land use on lots of having about 5% of the peak land values is different from each other according to regional character in city.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.2
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• pp.149-160
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• 2007

KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ${\sim}2.6\;t\;C\;ha^{-1}y^{-1}$. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric $CO_2$. The catchment scale water budget indicated that $30\sim40%$ of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about $12{\mu}mol\;CO_2/mmol\;H_2O$ with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.122-129
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• 1998

It were reported that antifungal mechanism of Enterobacter cloacae is a volatile ammonia that produced by the strain in soil, and the production of ammonia is related to the bacterial urease activity. A powerful bacterium SH14 against soil-borne pathogen Fusarium solani, which cause root rot of many important crops, was selected from a ginseng pathogen suppressive soil. The strain SH14 was identified as Bacillus subtilis by cultural, biochemical, morphological method, and $API^{circledR}$ test. From several in vitro tests, the antifungal substance that is produced from B. subtilis SH14 was revealed as heat-stable and low-molecular weight antibiotic substance. In order to construct the multifunctional biocontrol agent, the urease gene of Bacillus pasteurii which can produce pathogenes-suppressive ammonia transferred into antifungal bacterium. First, a partial BamH I digestion fragment of plasmid pBU11 containing the alkalophilic B. pasteurii l1859 urease gene was inserted into the BamH I site of pEB203 and expressed in Escherichia coli JM109. The recombinant plasmid was designated as pGU366. The plasmid pGU366 containing urease gene was introduced into the B. subtilis SH14 with PEG-induced protoplast transformation (PIP) method. The urease gene was very stably expressed in the transformant of B. subtilis SH14. Also, the optimal conditions for transformation were established and the highest transformation frequency was obtained by treatment of lysozyme for 90 min, and then addition of 1.5 ${mu}g$/ml DNA and 40% PEG4000. From the in vitro antifungal test against F. solani, antifungal activity of B. subtilis SH14(pGu366) containing urease gene was much higher than that of the host strain. Genetical development of B. subtilis SH14 by transfer of urease gene can be responsible for enhanced biocontrol efficacy with its antibiotic action.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.171-178
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• 2013

In this study, the sludge that occurs in the initial operation of coagulation system developed for the treatment of CSOs were returned to the flocculation reactor. The purposes of this study were to analyze the Characteristics of flocs that are generated through the recycling sludge and settling characteristics of sludge, and to evaluate the possibility that high concentrations of particulate matter in the initial inflow of CSOs could be used as an weighted coagulant additive. As a result, the concentration of treated CSOs pollutants at the beginning of the CSOs influent with a large amount of particulate matter over 20 ${\mu}m$ was low, after gradually increasing the concentrations of them. The flocs generated from the sludge return were similar in size compared to flocs generated through injection of micro sands, and settling velocity in case of return sludge injection was decreased from 55.1 cm/min to 21.5 cm/min. SVI value of the sludge accumulated at the bottom of the sedimentation tank was 72, and settled sludge volume decreased rapidly due to the consolidation of sludge to the time it takes to 10 minutes. these mean that sludge used for recycling has good settling characteristic. A condition of returned sludge which is 0.1% return of 0.3% extraction was formed in the balance of settlement and extraction. In this case, This condition was to be adequate to maintain the proper concentration such as 100~200 mg/L of TS and 50~100 mg/L of VS in the flocculation reactor. The usage of the return sludge containing particulate matters of CSOs as an weighted coagulant additive was able to secure a stable treated water quality despite the change of influent water quality dynamically. Furthermore, it can be expected to reduce the alum dosage along with the sludge production.

• Restorative Dentistry and Endodontics
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• v.30 no.2
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• pp.128-137
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• 2005

In this study we measured the amount of light energy that was projected through the tooth material and analyzed the degree of polymerization by measuring the surface hardness of composites. For polymerization, Optilux 501 (Demetron, USA) with two types of light guide was used: a 12 mm diameter light guide with 840 nW/$cm^2$ light intensity and a 7 mm diameter turbo light guide with 1100 nW/$cm^2$. Specimens were divided into three groups according to thickness of penetrating tooth (1 mm, 2 mm, 0 mm). Each group was further divided into four subgroups according to type of light guide and curing time (20 seconds, 40 seconds). Vickers' hardness was measured by using a microhardness tester. In 0 mm and 1 mm penetrating tooth group, which were polymerized by a turbo light guide for 40 seconds, showed the highest hardness values. The specimens from 2 mm penetrating tooth group, which were polymerized for 20 seconds, demonstrated the lowest hardness regardless of the types of light guides (p < 0.05). The results of this study suggest that, when projecting tooth material over a specified thickness, the increase of polymerization will be limited even if light intensity or curing time is increased.

• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.269-277
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• 1990

In planning the disaster prevention by the erosion control facilities, it is essential to focus on the microtopography of the channel bed and the chronological process of sedimental movement in the torrential streams. For this purpose, the microtopographical change of the channel bed and the effects of the erosion control facilities in the mountain torrents were analyzed by the experimental channel and the field survey of the torrents where low-dam series had been constructed in the channel. The results of this experiment showed that the effects of construction of the low-dam series on the channel bed fixiation were the prevention of the local scouring in the experimental channel and the expansion of flow channel width and deposit space. The results are summarized as follows : 1. When the low-dam series were constructed over the whole channel bed (L'/L=1), the conning water and the sediment were seperated, simultaneously resulting in deposition of sediment and reduction of the tractive force for the running water. Therefore, the F.A. (Fluctuation area in cross-section: value was decreased to about 65% compared with that of non-work (L'/L=0). 2. The efficiencies of the low-dam series on the channel width were increased with an increment in length of working space. After the construction of low-dam series on the whole channel bed (L'/L=1), flow channel width was increased to about 1.53 times compared with that of non-work (L'/L=0). 3. It needs a deposition area to store the sediment with decrease in tractive force. The low-dam series in the experimental channel widened the deposition area about 2.10 times compared with that of non-work.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.293-298
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• 2005

The embryonic and postembryonic developments of Pierodorus hybneri Linnaeus were observed in 5 different rearing cages such as A (Cylindrical, 10 cm in diameter, height of 4 cm), B (Cylindrical, 14.5 cm in diameter, height of 2.8 cm), C (Rectangle, 6.5 by 6.5 cm in $length{\times}breadth$, height of 10 cm), D (Cylindrical, 9 cm in bottom diameter, 11.5 cm in upper diameter, height of 10.8 cm) and E (Cylindrical, 15 cm in diameter, height of 7.5 cm) containing soybean and peanut seeds as feeding food, and sponge-water container under laboratory condition of $24^{\circ}C$ and 16L:8D. Egg duration was 6 days regardless of rearing cages. Hatchability ranged from 63 to 80% with the highest in B (14.5 cm in diameter, 2.8 cm in height) rearing cage. Instar duration was longer from 5 days in 1st instar to about 11 days in 5th instar. Nymphal duration showed 35 to 36 days with'3ut significant difference in rearing cages. Percent emergence was in range from 65 to 82% with the highest in B rearing cage. Adult longevity was 35 to 83 days for male, and 32 to 79 days for female, and was the longest in B rearing cage. Total number of eggs laid by female adult was in range from 38 to 86 with significant difference in rearing cages, and was the most in B rearing cage. Accordingly, the reproductive rate of P. hybneri for 1 generation was within 17 to 56 times, and was the highest in B rearing cage. Therefore, it could be concluded that B cage is most suitable for stable rearing of P. hybneri under laboratory condition.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.357-368
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• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.4
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• pp.435-444
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• 2009

Statement of problem: The clinical use of electric and electomagnetic fields for fracture healing applications began in the early 1970s. Since then, several technologies have been developed and shown to promote healing of fractures. Developments of these devices have been aided in recent years by basic research and several well controlled clinical trials not only in the medical field but in dentistry. Purpose: The purpose of this study was to compare alveolar bone reduction following immediate implantation using implants onto which magnets were attached in fresh extracted sockets. Material and methods: Four mongrel dogs were involved. Full buccal and lingual mucoperiosteal flaps were elevated and third and fourth premolars of the mandible were removed. Implants with magnets and implants without magnets were installed in the fresh extracted sockets and after 3 months of healing the animals were sacrificed. The mandibles were dissected and each implant sites were sampled and processed for histological examination. Results: The marginal gaps that were present between the implant and walls of the sockets at the implantation stage disappeared in both groups as a result of bone fill and resorption of the bone crest. The buccal bone crests were located apical of its lingual counterparts. At the 12 week interval the mean of marginal bone resorption in the control group was significantly higher than that of the magnet group. The majority of specimens in magnet group presented early bone formation and less resorption of the buccal marginal bone compared to the control group. Conclusion: Within the limitations of this study, it could be concluded that implants with magnets attached in the early stages of implantation may provide more favorable conditions for early bone formation and reduce resorption and remodeling of marginal bone.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.43-71
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• 1999

This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.