• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.53-63
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• 2012

The objectives of this study were to develop a linked watershed-waterbody modeling system and to assess the impacts of indirect wastewater reuse on irrigation water quality. The Osan stream watershed within Gyeonggi-do of South Korea was selected for this study. The linked modeling system was composed of the SWAT (Soil and water assessment tool) and QUALKO2 models. The SWAT model was calibrated and validated using the stream discharge and water quality data from 2010 to 2011. Runoff and non-point source pollutants from each subbasin and stream discharge from 1980 to 2009 were simulated by the SWAT model and applied to the QUALKO2 model. The QUALKO2 model was calibrated and validated under the conditions of low water and normal discharges, respectively. Finally, The 10-day irrigation water quality from April to September was simulated. The statistical measures of coefficient of determination ($R^2$), reliability index (RI), and efficiency index (EI) were used to evaluate the system performance. The $R^2$, RI and EI values ranged from 0.5 to 1.0, 1.03 to 1.92, and -35.03 to 0.95, respectively. The 10-day irrigation water quality showed the concentrations of BOD and coliform exceeded the water quality guidelines for wastewater reuse. The linked modeling system can be a useful tool to estimate non-point source pollutant loads in watershed and to control the water quality of effluent from a wastewater treatment plant and irrigation water in the downstream waterbody.

• Journal of Korean Society for Atmospheric Environment
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• v.1 no.1
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• pp.53-70
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• 1985

This study was performed to develop and to evaluate an air quality model for determining long-term average concentration of sulfur-dioxide for the Seoul area. CDMQC, TCM-2, and ISCLT were applied and tested in this comparison studies with same point source, area source emission data, and meteorological data to calculate seasonal concentration. Mean emission height of area sources was assumed 6m. Six different values of initial sigma Z for eah stability class were used for area sources. And decay half life was not considered in the model calculations. The results are highly correlated with measurements, the correlation coefficients of calculated and measured for CDMQC, TCM-2, and ISCLT are 0.85, 0.93, and 0.96, respectively.

• Journal of The Korean Digital Architecture Interior Association
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• v.6 no.2
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• pp.31-38
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• 2006

An architect for Cultural Technology have the most obligation to improve the cultural inheritance into an industrial resources. From an esthetical point of view, it is possible to put digital contents to a multiplicity of practical usage in the moment of its' digital conversion. These are practical resources out of an only duplication from the original. Developing cultural archetype into the most suitable model for one-source multi-use that is the core of the project. If you want to change an archetype, a Korean traditional architecture, into a creative source, you should develope a reappearance and a practical model harmonized with the image set. In addition, development process of cultural archetype digital contents based on ultimate idea and imagnation in our architectural culture, referred from cultural archetype and digital contents technology was offered by the study.

• Journal of Power Electronics
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• v.10 no.2
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• pp.165-170
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• 2010

This paper presents a comparative study of P and PI controllers for a current source inverter (CSI) fed induction motor drive system. A dq model has been used which incorporates the induction motor and the inverter power supply with current feedback. The model is used first to generate the steady state curves to determine the operating point through computer simulations using the software package MATLAB. Then a transient analysis has been carried out for different values of the speed and current controller parameters. The controller value is adjusted by the Ziegler-Nichols method. It has been observed that the transient time to reach the steady state value is larger with the PI controller than with the P controller.

• Progress in Medical Physics
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• v.12 no.1
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• pp.19-29
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• 2001

In dose modeling, the shape of actual source and sealed capsule are important parameter to determine the physical dose computation. The author investigated the effect of filter of source self-absorption and sealed capsule to designed the high dose rate Ir-192 source for Ralstron(Japan) unit. The size of source designed to 1.5 mm $\Phi$ x 1.5mm length of actual source sealed with stainless steel which is 3.0mm $\Phi$ x 12.0mm length connected to driving cable. The dose attenuation was derived 66.3 % from 2655 segmented source at reference point of 10mm lateral distance of source. The output dose rate factor in tissue for designed source showed 0.0013511 cGy/mCi-sec in reference point at 1cm lateral distance of source center. The dose distribution at inferior of source showed the 52% of that of source tip region, however, the filtering effect was small as 4% at 45degrees of source axis. The dose attenuation within 20 degrees of source axis at near source-cable connector showed large filtering effect as 40% over, but the small effect was revealed isotropic dose distribution at large angle.

• Journal of Environmental Health Sciences
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• v.16 no.2
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• pp.1-10
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• 1990

This study was performed to evaluate a applicability of TCM(Texas Climatological Model) model to a industrial area sush as CUNSAN and a possibility to provide necessary informaitons for air quality management. The air pollutants were measured at 6 sampling sites of GUNSAN industrial area from june to july in 1989. The model was checked by comparing the observed data with estimated data. The meteorological data for wind direction and wind speed were obtained from the observatory station in GUNSAN. The results are summarized as follows. 1. Average concentrations of air pollutants at all sampling sites were SO$_{2}$ 0.011-0.019 ppm. NO$_{2}$ 0.012-0.017 ppm. CO 0.6-1.0 ppm. TSP 45.8-64.2 $\mu$g/m$^{3}$. 2. The emission amounts show that point source are in general higher than area source. 3. As a results of correlation analysis, relationship between SO$_{2}$ concentration in the observed value and estimated value showed positive significance.(r = 0.766) 4. The sulfer content of the 1.6% at present to 0.8%, which means a 53.3% reduction. By controlling stack height could be lowered 14.5%, but the effective way of emission control is use of the lower sulfer fuels than controlling stack height. 5. The ratio between SO$_{2}$ contration in the observed value and estimated value showed 1.05. There-fore, the TCM model was quite effective in predicting air quality in GUNSAN industrial area.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.878-881
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• 2003

To acquire an appointed speaker's clear voice signal from inspect-camera, picture-conference or hands free microphone eliminating interference noises needs to be preceded speaker's position automatically. Presumption of sound source position's basic algorithm is about measuring TDOA(Time Difference Of Arrival) from reaching same signals between two microphones. This main project uses ADF(Adaptive Delay Filter) [4] and CPS(Cross Power Spectrum) [5] which are one of the most important analysis of TDOA. From these analysis this project proposes presumption of real time sound source position and improved model NI-ADF which makes possible to presume both directions of sound source position. NI-ADF noticed that if auditory sense of humankind reaches above to some specified level in specified frequency, it will accept sound through activated nerve. NI-ADF also proposes practicable algorithm, the presumption of real time sound source position including both directions, that when microphone loads to some specified system, it will use sounds level difference from external system related to sounds of diffraction phenomenon. In accordance with the project, when existing both direction adaptation filter's algorithm measures sound source, it increases more than twice number by measuring one way. Preserving this weak point, this project proposes improved algorithm to presume real time in both directions.

• Journal of Korean Society of Rural Planning
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• v.24 no.4
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• pp.99-119
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• 2018

Unit load factor, which is used for the quantification of non-point pollution in watersheds, has the limitation that it does not reflect spatial characteristics of soil, topography and temporal change due to the interannual or seasonal variability of precipitation. Therefore, we developed the method to estimate a watershed-scale non-point pollutant load using seasonal forecast data that forecast changes of precipitation up to 6 months from present time for watershed-scale water quality management. To establish a preemptive countermeasure against non-point pollution sources, it is possible to consider the unstructured management plan which is possible over several months timescale. Notably, it is possible to apply various management methods such as control of sowing and irrigation timing, control of irrigation through water management, and control of fertilizer through fertilization management. In this study, APEX-Paddy model, which can consider the farming method in field scale, was applied to evaluate the applicability of seasonal forecast data. It was confirmed that the rainfall amount during the growing season is an essential factor in the non-point pollution pollutant load. The APEX-Paddy model for quantifying non-point pollution according to various farming methods in paddy fields simulated similarly the annual variation tendency of TN and TP pollutant loads in rice paddies but showed a tendency to underestimate load quantitatively.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1691-1698
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• 2001

In recent years, significant progress has been made in modeling turbulence behavior in plasma and its effect on transport. It has also been made in diagnostics for turbulence measurement; however, there is still a large gap between theoretical model and experimental measurements. Visualization of turbulence can improve the connection to theory and validation of the theoretical model. One method to visualize the flow structures in plasma is a laser Schlieren imaging technique. We have recently applied this technique and investigated the characteristics of a highly underexpanded pulsed plasma jet originating from an electrothermal capillary source. Measurements include temporally resolved laser Schlieren imaging of a precursor blast wave. Analysis on the trajectory of the precursor blast wave shows that it does not follow the scaling expected for a strong shock resulting from the instantaneous deposition of energy at a point. However, the shock velocity does scale as the square root of the deposited energy, in accordance with the point deposition approximation.

• Journal of Communications and Networks
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• v.13 no.5
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• pp.511-517
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• 2011

The capacity of wireless ad-hoc networks is analyzed for all kinds of information dissemination based on single and multiple packet reception schemes under the physical model. To represent the general information dissemination scheme, we use (n, m, k)-cast model [1] where n, m, and k (k ${\leq}$ m) are the number of nodes, destinations and closest destinations that actually receive packets from the source in each (n, m, k)-cast group, respectively. We first consider point-to-point communication, which implies single packet reception between transmitter-receiver pairs and compute the (n, m, k)-cast communications. Next, the achievable throughput capacity is computed when receiver nodes are endowed with multipacket reception (MPR) capability. We adopt maximum likelihood decoding (MLD) and successive interference cancellation as optimal and suboptimal decoding schemes for MPR. We also demonstrate that physical and protocol models for MPR render the same capacity when we utilize MLD for decoding.