• Journal of the Korean Ceramic Society
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• v.41 no.7
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• pp.560-566
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• 2004

To fabricate the continuously porous alumina bodies by multi-extrusion process, carbon powder and ethylene vinyl acetate were used as a pore forming agent and a binder, respectively. As the change of extrusion pass number, reduction ratio as well as the volume fraction of core and tube, the porous alumina bodies having various kind of pore size and porosity could be obtained. The porous bodies showed continuous pore shape, high specific surface as well as high bending strength, which were compared with those of commercial alumina bodies. In-vitro study was carried out using MG-63 osteoblast cells to investigate of their biocompatibility. As a result, the cells grew well on top and bottom as well as inside surface of pore. From the result of in-vivo study of 3-dimensional porous alumina bodies using rats, it was confirmed that any inflammatory response was not found in the subcutaneous tissue around porous body. Also the porous bodies removed from the rats were fully covered with well-developed fibrous tissues and showed the formation of new capillary blood vessels.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.117-125
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• 2002

This study experimented a possibility of advanced treatment through microorganism that converts $NH_3-N$ to organic nitrogen in wastewater contaminated by ammoniac nitrogen unlike conventional nitrogen removal process. After distributing three kinds of special bacteria that use $NH_3-N$ as a substrate, when those bacteria were cultured in no salt condition and salt condition (3% NaCl), M11 showed better growth in salt condition and M12 showed better growth in no salt condition. However M7l grew well in both no salt condition and salt condition. In the test of glucose effect, maximum growth and removal rate were observed in glucose concentration of 5g/L but in high concentration (1000mg/L as $NH_3-N$) of $NH_3-N$ growth and removal rate were low. Removal rate was the highest in 100mg/L $NH_3-N$ and the fact that concentration of $NO_2-N$ and $NO_3-N$ didn't increase assumed $NH_3-N$ was converted to organic nitrogen. Optimum concentration of $K_2HPO_4$ for phosphorous supply and buffer was 5g/L. Special bacteria distributed could use $NO_2-N$ and $NO_3-N$ as well as $NH_3-N$ as substrates. This study showed that when growth rate of bacteria was high removal rate also was high. It is possible to apply as a method to treat wastewater polluted by $NH_3-N$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.247-259
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• 2007

In this study, we examined the flux of carbon and water using an eco-hydrological model, Regional Hydro-Ecologic Simulation System (RHESSys). Our purposes were to develop a set of parameters optimized for a well-designed experimental watershed (Gwangneung Research Watershed, GN) and then, to test suitability of the parameters for predicting carbon and water fluxes of other watershed with different regimes of climate, topography, and vegetation structure (i.e Gangseonry Watershed in Mt. Jumbong, GS). Field datasets of stream flow, soil water content (SWC), and wood biomass product (WBP) were utilized for model parameterization and validation. After laborious parameterization processes, RHESSys was validated with the field observations from the GN watershed. The parameter set identified at the GN watershed was then applied to the GS watershed in Mt. Jumbong, which resulted in good agreement for SWC but poor predictability for WBP. Our study showed that RHESSys simulated reliable SWC at the GS by adjusting site-specific porosity only. In contrast, vegetation productivity would require more rigorous site-specific parameterization and hence, further study is necessary to identify primary field ecophysiological variables for enhancing model parameterization and application to multiple watersheds.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.521-530
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• 2018

This paper proposes "The Agriculture Decision-making System(ADS) based on Deep Learning for improving crop productivity" that collects weather information based on location supporting precision agriculture, predicts current crop condition by using the collected information and real time crop data, and notifies a farmer of the result. The system works as follows. The ICM(Information Collection Module) collects weather information based on location supporting precision agriculture. The DRCM(Deep learning based Risk Calculation Module) predicts whether the C, H, N and moisture content of soil are appropriate to grow specific crops according to current weather. The RNM(Risk Notification Module) notifies a farmer of the prediction result based on the DRCM. The proposed system improves the stability because it reduces the accuracy reduction rate as the amount of data increases and is apply the unsupervised learning to the analysis stage compared to the existing system. As a result, the simulation result shows that the ADS improved the success rate of data analysis by about 6%. And the ADS predicts the current crop growth condition accurately, prevents in advance the crop diseases in various environments, and provides the optimized condition for growing crops.

• Fire Science and Engineering
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• v.33 no.1
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• pp.69-75
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• 2019

In this study, the combustibility of five types of plastic plates, fiber reinforced plastic (FRP), polystyrene (PS), polycarbonate (PC), polypropylene (PP), and polyvinyl chloride (PVC), were tested using a cone calorimeter (ISO 5660). The PVC plate showed a $44.65kW/m^2$ lower peak heat release rate (HRR) and a $30.97kW/m^2$ lower maximum average rate of heat emission than the other four types of plastics, whereas the PS plate showed a $773.44kW/m^2$ higher peak HRR and $399.14kW/m^2$ higher maximum average rate of heat emission. The PC plate and PS plate showed the highest HRR by a maximum of 3.88 times in $CO_{mean}$ yields, while the PS pate and PP plate showed the highest HRR by a maximum 4.88 times in $CO_{2mean}$ yields. In addition, the smoke performance index (SPI) of the PS plate decreased by 74.81%~95.99%; the smoke growth index (SGI) increased to 76%~300%; the smoke intensity (SI) also increased to 917.73% ~ 9607.57%, and the danger of smoke increased. The PS plate was found to have the highest risk of life damage due to smoke on the thermal and smoke sides.

• Resources Recycling
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• v.32 no.6
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• pp.25-33
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• 2023

With the growth of the battery industry, a rapid increase in the production and usage of lithium-ion batteries is expected, and in line with this, much interest and effort is being paid to recycle waste batteries, including production scrap. Although much effort has been made to recycle cathode material, much attention has begun to recycle anode material to secure the supply chain of critical minerals and improve recycling rates. The proximate analysis that measures the content of coal can be used to analyze graphite in anode material, but it cannot accurately analyze due to the interaction between the components of the black mass. Therefore, in this study, thermogravimetric analysis of each component of black mass was measured as the temperature increased up to 950℃ in an oxygen atmosphere. As a result, in the case of cathode material, no change in mass was measured other than a mass reduction of about 5% due to oxidation of the binder and conductive material. In the case of anode material, except for a mass reduction of about 2% due to the binder, all mass reduction were due to the graphite(fixed carbon). In addition, metal conductors (Al, Cu) were oxidized and their mass increased as the temperature increased. Thermal analysis results of mixed samples of cathode/anode show similar results to the predictive values that can be calculated through each cathode and anode analysis results.

• The KIPS Transactions:PartD
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• v.13D no.7 s.110
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• pp.985-996
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• 2006

As the internet technologies develop, the geographic information system environment is changing to the web-based service. Since geospatial information of the existing Web-GIS services were developed independently, there is no interoperability to support diverse map formats. In spite of the same geospatial information object it can be used for various proposes that is duplicated in GIS separately. It needs intelligent strategies for optimal replica selection, which is identification of replication geospatial information objects. And for management of replication objects, OMG, GLOBE and GRID computing suggested related frameworks. But these researches are not thorough going enough in case of geospatial information object. This paper presents a model of location service, which is supported for optimal selection among replication and management of replication objects. It is consist of tree main services. The first is binding service which can save names and properties of object defined by users according to service offers and enable clients to search them on the service of offers. The second is location service which can manage location information with contact records. And obtains performance information by the Load Sharing Facility on system independently with contact address. The third is intelligent selection service which can obtain basic/performance information from the binding service/location service and provide both faster access and better performance characteristics by rules as intelligent model based on rough sets. For the validity of location service model, this research presents the processes of location service execution with Graphic User Interface.

• Journal of Environmental Policy
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• v.13 no.4
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• pp.3-49
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• 2014

Growing interest of stakeholders on corporate responsibilities for environment and tightening environmental regulations are highlighting the importance of environmental management more than ever. However, companies' awareness of the importance of environment is still falling behind, and related academic works have not shown consistent conclusions on the relationship between environmental performance and economic performance. One of the reasons is different ways of measuring these two performances. The evaluation scope of economic performance is relatively narrow and the performance can be measured by a unified unit such as price, while the scope of environmental performance is diverse and a wide range of units are used for measuring environmental performances instead of using a single unified unit. Therefore, the results of works can be different depending on the performance indicators selected. In order to resolve this problem, generalized and standardized performance indicators should be developed. In particular, the performance indicators should be able to cover the concepts of both environmental and economic performances because the recent idea of environmental management has expanded to encompass the concept of sustainability. Another reason is that most of the current researches tend to focus on the motive of environmental investments and environmental performance, and do not offer a guideline for an effective implementation strategy for environmental management. For example, a process improvement strategy or a market discrimination strategy can be deployed through comparing the environment competitiveness among the companies in the same or similar industries, so that a virtuous cyclical relationship between environmental and economic performances can be secured. A novel method for measuring eco-efficiency by utilizing Data Envelopment Analysis (DEA), which is able to combine multiple environmental and economic performances, is proposed in this report. Based on the eco-efficiencies, the environmental competitiveness is analyzed and the optimal combination of inputs and outputs are recommended for improving the eco-efficiencies of inefficient firms. Furthermore, the panel analysis is applied to the causal relationship between eco-efficiency and economic performance, and the pooled regression model is used to investigate the relationship between eco-efficiency and economic performance. The four-year eco-efficiencies between 2010 and 2013 of 23 companies are obtained from the DEA analysis; a comparison of efficiencies among 23 companies is carried out in terms of technical efficiency(TE), pure technical efficiency(PTE) and scale efficiency(SE), and then a set of recommendations for optimal combination of inputs and outputs are suggested for the inefficient companies. Furthermore, the experimental results with the panel analysis have demonstrated the causality from eco-efficiency to economic performance. The results of the pooled regression have shown that eco-efficiency positively affect financial perform ances(ROA and ROS) of the companies, as well as firm values(Tobin Q, stock price, and stock returns). This report proposes a novel approach for generating standardized performance indicators obtained from multiple environmental and economic performances, so that it is able to enhance the generality of relevant researches and provide a deep insight into the sustainability of environmental management. Furthermore, using efficiency indicators obtained from the DEA model, the cause of change in eco-efficiency can be investigated and an effective strategy for environmental management can be suggested. Finally, this report can be a motive for environmental management by providing empirical evidence that environmental investments can improve economic performance.