• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.852-859
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• 2006

The novel microbial process such as Anammox(anaerobic ammonium oxidation) and Canon(completely autotrophic nitrogen removal over nitrite) processes is promising biotechnology to remove nitrogen from ammonium-rich wastewater like anaerobic sludge digester liquid. In this research, a new Canon-type nitrogen removal process adopting upflow granular sludge bed type configuration was investigated on its feasibility and process performance, using synthetic wastewater and sludge digester liquids. Air as an oxygen source was provided in an external aeration chamber with flow recirculation. In the first experiment using the synthetic wastewater(up to 110 mg $NH_4$-N $L^{-1}$), the ammonium removal was about 95%(92% for T-N) at effective hydraulic retention time(HRT) for 3.8 days. In the second experiment using the sludge digester liquids($438{\pm}26$ mg $NH_4$-N $L^{-1}$), the total nitrogen removal was $94{\pm}1.7%$ at HRT for 5.4 days and $76{\pm}1.5%$ at HRT for 3.8 days, respectively. Little nitrite and nitrate were observed in the effluent of both experiments. The process revealed quite a lower oxygen($0.29{\sim}0.59$ g $O_2$ $g^{-1}N$) and less alkalinity($3.1{\sim}3.4$ g $CaCO_3$ $g^{-1}N$) consumption as compared to other new technology in microbial nitrogen removal. The process also offers the economical compact reactor configuration with excellent biomass retention, resulting in lower cost for investment and maintenance.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.528-533
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• 2016

One of ways for effectively maintaining asbestos buildings is to select asbestos buildings to be removed firstly by manufacturing and analyzing asbestos map of various topics. Thus, in this study we manufactured asbestos map of various topics for the effective management of asbestos buildings owned by Seoul using QGIS (Quantum Geographic Information System). To select asbestos buildings likely to cause asbestos scattering problem and exposure into the air, we comprehensively took into consideration various topics such as asbestos buildings density, asbestos-area ratio, asbestos buildings distribution considering the population, first removal object, risk assessment, elapsed year. As described in this study, using the GIS may be utilized as a method for selecting asbestos buildings to be removed firstly as well as distribution of asbestos buildings. In the future, it is necessary to make assessment criteria considering diversification of property value in GIS such as the characteristics of the living environment around the asbestos buildings. This is expected to be utilized to manage the vulnerable region to asbestos exposure.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1825-1832
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• 2000

Column experiments were conducted by using soil columns, to investigate feasibility and efficiency of in-situ ozone enhanced remediation for diesel-contaminated soil. The injection of gaseous ozone into soil column revealed the enhanced decomposition of ozone due to the catalytic reaction between ozone and metal (e.g., Fe, Mn etc.) oxides as evidenced by as much as 25 times shorter half-life of ozone in a sand packed column than in a glass beads packed column. Substantial retardation in the transport of and the consumption of ozone were observed in the diesel contaminated field soil and sand packed columns. After 16 hrs ozonation, 80% of the initial mass of diesel (as diesel range organic) concentration of $800{\pm}50mg/kg$, was removed under the conditions of the flow rate of 50mL/min and $6mg-O_3/min$. Whereas, less than 30% of diesel was removed in the case of air injection. Analysis of the residual TPH(total petroleum hydrocarbon) and selected 8 aliphatics of diesel compounds in the inlet and the outlet of the column confirmed that diesel nonselectively reacted with ozone and then shifted to lower carbon numbered molecules. Water content also was found to be an important parameter in employing ozone to the hydrocarbon-contaminated soil.

• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.100-108
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• 2008

In this paper, the dual-ground, high-gain and broad-band internal antenna has been designed and fabricated for 4th-generation mobile communication applications. The optimized antenna was fabricated using photolithography method. The antenna consist of the patches, antenna and system ground, and a probe. The patch and ground plane were separated by air. In order to prevent the demage due to radiator swaying, the foams(${\varepsilon}_r{\fallingdotseq}1.03$) were used to fix the patches and ground. The conductor for the radiators was 0.05 [mm] thick. The measured input return loss showed less than -10 [dB] at the broadband from 3499 to 4743 [MHz]. It's measured bandwidth was 1244 [MHz]. The radiation patterns measured at 3400, 3600, 3800, 4000 and 4200 [MHz] showed Omni-directional characteristics. The gain in the E-plane and H-plane was 4.7 ~ 6.1 and 2.1 ~ 4.3 [dBi], respectively.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.710-714
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• 2009

In this study, we analyzed the desulfurization performance of Zn-based dry sorbents according to the reducing power, water vapor content and $H_2S$ inlet concentration of coal gas in a batch-type fluidized-bed reactor. We used three different coal gas composition with different reducing power such as KRW air-blown coal gas, Shell oxygenblown coal gas and IAE coal gas. The experiments were performed by changing the inlet concentration of water vapor and $H_2S$ in a coal gas. Water vapor content was varied from 5% to 30% and $H_2S$ inlet concentration from 0.5% to 2.0%. As both the water vapor content and $H_2S$ inlet concentration increased, desulfurization performance of Zn-based sorbents decreased regardless of the reducing power of the coal gas. The minimum desuflurization performance was, however, above 99.5% for all experimental conditions, which implied that Zn-based dry sorbents could be used to remove $H_2S$ up to 99%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.537-544
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• 2016

National Competency Standards (NCS) need to be introduced to train newly hired staff and to gradually improve employees' work performance in the information security industry. In particular, the introduction of a new NCS curriculum for new hires is important in order to retain and efficiently manage professionals in the information security field. However, the legacy NCS is not clearly designed for the information security field. So a formal curriculum has been suggested for institutions training the information security workforce. Therefore, this study establishes a competency unit based on the types of personnel, their duties, and required knowledge. To select the competency unit, this study reviewed prior research to understand the required skills and work knowledge, and reviewed recruitment-based NCS that public agencies and public and private companies have carried out, including them in the study. The selected competency unit was classified into a required competency unit and an elective competency unit based on the importance of the duties and the demands of training. Through a verification process for the new, licensed career path model in the NCS information and communications field, this study suggests updated NCS competency units and required courses to provide an appropriate NCS curriculum for newly hired employees in the information security industry.

• International Commerce and Information Review
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• v.15 no.2
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• pp.3-23
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• 2013

In 1997, 180 countries signed the Kyoto Protocol in Kyoto, Japan. The Kyoto Protocol came into force in February 2005. The agreement calls for industrialized nations to cut greenhouse gas emissions by 5 percent from 1990 levels by 2008 to 2012. One of those polices is a modal shift that change from road freight to sea, inland waterway and railroad transportation that is eco-friendly. The increase of road freight brings road congestion, accidents, logistic costs, air pollution and greenhouse gases. Railroads are superior than the other modes of transportation in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. Korean railroads were used by passengers and freight transport popularly until the middle of 20th century, however, by the sudden change of logistics environments, a shaving time efficiency being most important, railroad logistic lost its competitive power against the transportation by truck. From the research which sees consequently investigated a various policy, a system and a law about Chinese logistics industry and present condition of the Chinese goods enterprise and instance analysis of the large Chinese corporation that branch out to undeveloped markets led and a Chinese logistics industry and problem point escape hereafter the heightening of competitiveness plan which is rational under prsenting boil.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1077-1083
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• 1999

This study was aimed to evaluate the effectiveness of hydrophilic, lipophilic antioxidants and emulsifiers by HLB (hydrophilic lipophilic balance) in different oil systems. Lipophilic antioxidant (${\delta}-tocopherol$), hydrophilic antioxidant (gallic acid) and emulsifier(lecithin, tween 20, span 60) were evaluated in relation to oil stability in bulk oil system (soybean oil) and emulsified with Tween 80 at $60^{\circ}C$. In the storage test ($60^{\circ}C$), gallic acid was more effective on the stability of oil oxidation than ${\delta}-tocopherol$ in bulk and emulsion system. Lecithin as a hydrophilic emulsifier was more effective than tween 20 on the stability of oil oxidation in bulk and emulsion system. Also span 60, a lipophilic emulsifier, was more effective than tween 20, a hydrophilic emulsifier, in bulk and emulsion systems.

• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.1-12
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• 2006

This study was carried out to compile year 2001 forest resource statistics for the State of Virginia. USA. Virginia has 15.8 million acres (6.4 million ha) of forested 1and, accounting for 62% of the landcover with non-industrial private forest landowners owning 77% of the forested area. Deciduous forests make up 78% of Virginia's forests. Total tree volume is 26.5 billion cubic ft, of which average volume per acre is $1.677ft^3/ac(117m^3/ha)$. The overall annual volume of roundwood output is $543\;million\;ft^3$. Tree growth exceeds removals by $271\;million\;ft^3$ each year for all species statewide. Average net forest land loss in Virginia is 20,000 acre (8,094 ha) per year. In 1999, the forest products industry contributed over $25.4 billion to Virginia's economy while providing over 248,000 jobs. Among forest industries logging contributes to the economy at over $863 million/yr; timber accounts for the greatest amount (28%) of the total market value of Virginia's agricultural crops. Revenue received from stumpage by landowners exceeded $345 million/yr. In their entirety. Virginia's forests provide over $30.5 billion in annual return. including $3 billion for recreation and $1.9 billion for carbon sequestation and pollution control.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.83-91
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• 2006

This research was initiated to enhance the tilth of fine-textured soil for turf growth by incorporation of crumb rubber shredded from used tires. A specific objective was to determine the physical properties of soil mixes amended with different grade and amount of crumb rubber in soils. Two soils and three different grades(3.5, 6.5 and 9.5 mm) of crumb rubber were used. The soils selected were an Arenzville silt loam(coarse-silty, mixed, nonacid, mesic Typic Udifluvents) and a Hosmer silty clay loam(fine-silty, mixed, mesic Typic Fragiudalfs). The amount of crumb rubber mixed in soil ranged from 0 to 0.4 $g{\cdot}g^{-1}$(using 0.05 $g{\cdot}g^{-1}$) increments and 0 as a control. For each treatment, soil cores were constructed following the recommendation by the United States Golf Association Green Section Record. Results indicated that porosity of the mixes decreased as the amount of crumb rubber increased. Regardless of the grade of crumb rubber, mixes with less than 0.15 $g{\cdot}g^{-1}$ of crumb rubber in fine-textured soil could not enhance their macro-porosity and hydraulic conductivity. However, as the amendment increased over 0.15 $g{\cdot}g^{-1}$, the tilth of the mixes had improved significantly macro-porosity, hydraulic conductivity and air permeability, as compared with a control.