• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.4
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• pp.22-34
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• 2007

The purpose of this study is to evaluate landscape characteristics of watersheds in the Nakdong River Basin for identifying the groups of watershed with similar landcover patterns by using Geographic Information System and statistical technique. According to the results based on the cluster analysis using cluster analysis tool in the ArcGIS 8.3 program, 22 sub-watersheds were classified into three types; "Forest watershed", "Agriculture watershed", and "Urban watershed". In the forest watershed that has the least potential of ecological disturbances by human, a forest management approach based on geographic conditions and coverage types, etc., should be developed to sustain the ecological and environmental functions of forest. For the agriculture watershed, environmental-friendly agricultural techniques should be performed in the particular enhancement of riparian buffer zone to the prevent direct inflow of soils, fertilizers, and other chemicals into the stream network. Finally, in the urban watershed, an environmental-friendly plan that may increase the ratio of pervious surface and amount of green-space to should be reserved.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.153-156
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• 2003

In this paper, we studied advanced audio/ voice information processing techniques, and trying to introduce more human friendly audio/voice. It is just in the beginning stage. Firstly, we approached in well-known time-domain methods such as moving average, differentiation, interpolation, and decimation. Moreover, some variation of them and envelope contour modification are utilized. We also suggested the MOS test to evaluate subjective listening factors. In the long term viewpoint, user's preference, mood, and environmental conditions will be considered and according to them, we hope our future technique can adapt speech and audio signals automatically.

• Journal of Positioning, Navigation, and Timing
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• v.6 no.4
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• pp.211-221
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• 2017

Ellipsodially referenced survey (ERS) is considered as one of the challenging issues in the hydrographic surveys due to the fact that the bathymetric data collected by this technique can be readily transformed either to the geodetic or the chart datum by application of some geoscientific models. Global Navigation Satellite Systems (GNSS) is a preferred technique to determine the ellipsoidal height of a vessel reference point (RP) because it provides cost-effective and unprecedentedly accurate positioning solutions. Especially, the GNSS-derived heights include heave and dynamic draft of a vessel, so as for the reduced bathymetric solutions to be potentially free from these corrections. Although over the last few decades, differential GNSS (DGNSS) has been widely adopted in the bathymetric surveys, it only provides limited accuracy of the vertical component. This technical barrier can be effectively overcome by adopting the so-called GNSS carrier phase (CPH) based techniques, enhancing accuracy of the height solution up to few centimeters. From the positioning algorithm standpoint, the CPH-based techniques are categorized under absolute and relative positioning in post-processing mode; the former is precise point positioning (PPP) correcting errors by the global or regional models, the latter is post-processed kinematic positioning (PPK) that uses the differencing technique to common error sources between two receivers. This study has focused on assessment of achievable accuracy of the ellipsoidal heights obtained from these CPH-based techniques with a view to their applications to hydrographic surveys where project area is, especially, few tens to hundreds kilometers away from the shore. Some field trials have been designed and performed so as to collect GNSS observables on static and kinematic mode. In this paper, details of these tests and processed results are presented and discussed.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.115-119
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• 2010

Zinc (Zn) is an essential element required for growth and development of plants. However, Zn can be toxic to plants when it presents excessive amount. Phytoextraction is an economic and environment-friendly technique using plants to clean-up metal-contaminated soils. However, the technique cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. Therefore, this research focuses on identifying chelating agents which are biodegradable and applicable to highly metalcontaminated areas. Zn as a target metal and cysteine (Cys), histidine (His), malate, citrate oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Plants were grown on agar media containing various chelating agents with Zn to analyze the effect on plant growth. Malate and His slightly increased the inhibitory effect of Zn on root growth of plants, whereas Cys, citrate, oxalate, and succinate did not show significant effects. However, EDA strongly diminished the inhibitory effect of Zn on root growth. The effect of EDA is correlated with decreased Zn uptake into the plants. In conclusion, as biodegradable chelating agents, EDA is a good candidate for growth of plants in highly Zn-contaminated areas.

• Parasites, Hosts and Diseases
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• v.59 no.2
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• pp.113-119
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• 2021

The computer vision diagnostic approach currently generates several malaria diagnostic tools. It enhances the accessible and straightforward diagnostics that necessary for clinics and health centers in malaria-endemic areas. A new computer malaria diagnostics tool called the malaria scanner was used to investigate living malaria parasites with easy sample preparation, fast and user-friendly. The cultured Plasmodium parasites were used to confirm the sensitivity of this technique then compared to fluorescence-activated cell sorting (FACS) analysis and light microscopic examination. The measured percentage of parasitemia by the malaria scanner revealed higher precision than microscopy and was similar to FACS. The coefficients of variation of this technique were 1.2-6.7% for Plasmodium knowlesi and 0.3-4.8% for P. falciparum. It allowed determining parasitemia levels of 0.1% or higher, with coefficient of variation smaller than 10%. In terms of the precision range of parasitemia, both high and low ranges showed similar precision results. Pearson's correlation test was used to evaluate the correlation data coming from all methods. A strong correlation of measured parasitemia (r²=0.99, P<0.05) was observed between each method. The parasitemia analysis using this new diagnostic tool needs technical improvement, particularly in the differentiation of malaria species.

• Journal of Magnetics
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• v.16 no.2
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• pp.120-124
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• 2011

The design of an air compressor-driving quadratic linear actuator in a fuel cell BOP system is studied using orthogonal techniques. The approach utilizes an orthogonal array for design of 'experiments', i.e. the scheme for numerical simulations using a finite element method. Eco-friendly energy is increasingly important due to the depletion of fossil fuels and environmental pollution. Among the new energy sources, fuel cell is spotlighted as renewable energy because it produces few dusts. The air compressor performance is directly related to the efficiency of the fuel cell BOP system has high power consumption. In this paper, an optimized technique using an orthogonal matrix is applied to the design problem to improve the performance of quadratic linear actuator.

• Steel and Composite Structures
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• v.51 no.2
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• pp.127-138
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• 2024

In this paper, structural behavior under fire conditions is comprehensively examined, and a novel software interface for testing interfaces efficiently is developed and validated. In order to accurately assess the response of structures to fire scenarios, advanced simulation techniques and modeling approaches are incorporated into the study. This interface enables accurate heat transfer analysis and thermo-mechanical simulations by integrating software tools such as CSI ETABS, CSI SAP2000, and OpenSees. Heat transfer models can be automatically generated, simulation outputs processed, and structural responses interpreted under a variety of fire scenarios using the proposed technique. As a result of rigorous testing and validation against established methods, including Cardington tests on scales and hybrid simulation approaches, the software interface has been proven to be effective and accurate. The analysis process is streamlined by this interface, providing engineers and researchers with a robust tool for assessing structural performance under fire conditions.

• Environmental Engineering Research
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• v.17 no.3
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• pp.125-132
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• 2012

The removal of Cd(II) and Cu(II) from aqueous solution by an agricultural solid waste biomass prepared from Moringa oleifera bark (MOB) was investigated. The biosorbent was characterized by Fourier transform infrared spectroscopy and elemental analysis. Furthermore, the effect of initial pH, contact time, biosorbent dosage, initial metal ion concentration and temperature on the biosorption of Cd(II) and Cu(II) were studied using the batch sorption technique. Kinetic studies indicated that the biosorption process of the metal ions followed the pseudo-second order model. The biosorption data was analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Based on the Langmuir isotherm, the maximum biosorption capacities for Cd(II) and Cu(II) onto MOB were 39.41 and 36.59 mg/g at 323 K, respectively. The thermodynamic parameters, Gibbs free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$), and entropy (${\Delta}S^o$) changes, were also calculated, and the values indicated that the biosorption process was endothermic, spontaneous and feasible in the temperature range of 303-323 K. It was concluded that MOB powder can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Cd(II) and Cu(II) ions from aqueous solution.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.365-370
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• 2009

LCA is a tool to support for making decisions by offering information of environmental aspects of products or services. It can be used to make decisions to consumers and NGOs as well as government and enterprises. LCA evaluates the environmental aspects throughout the entire life cycle of a product. Therefore it can quantify and assess environmental impacts from raw material acquisition, manufacturing, distribution, use and disposal to end of life and recycling. The demands of the recycling rate increase and the use of suitable materials for RoHS, REACH, WEEE, ELV which are linked trade with environmental regulation have increased the worldwide. Global warming is the critical challenge of the world facing. And under post-Kyoto protocol each country has to prepare for target reduction, so it became essential to save energy and resources. In addition that, the carbon mark has been run as the way of showing example of CO2 reduction in domestic and it will be extended gradually. And also through the introduction of Eco-label, environmentally-friendly product will be promoted. When those systems are operated, global warming gases (i.e. CO2) can be calculated throughout the entire life of the products by LCA. And the environmental impacts such as harmful material emission in the process of manufacturing, energy consumption, distribution and so on, can also be assessed. Therefore, The basic concepts of LCA technique and various cases and the practical application in the future will be review in this study.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.173-183
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• 2010

Numerical analysis using a three dimensional finite element program(ABAQUS) is a powerful method which can evaluate the soil-pile-structure interaction under the dynamic loading and reduce the computation time significantly, but has not be widely used because modeling a soil-pile system and setting the parameter for the entire model are difficult and a three dimensional finite element program is not user friendly. However, a three dimensional finite element program is expected to be widely used because of advance in research of modeling technique and development of the modeling and visualization. In this study, ABAQUS is used to simulate the 1g shaking table model pile test, and the numerical results are compared with the 1g shaking table test results. The application about the soil stiffness and boundary condition change is estimated and then parametric study for various input acceleration amplitudes, various input frequencies, and various surcharge is carried out.