• Journal of Institute of Control, Robotics and Systems
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• v.6 no.11
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• pp.1039-1044
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• 2000

In this paper, the error caused by the measurement delay in INS/GPS integrated systems with Kalman filtering is defined and analyzed through the analytical method and the simulation. It is proved that the error of measurement delay causes not only the position error but also the estimate error of the x-axis accelerometer bias when a vehicle turns. And the estimation method of the delay time and the compensation method using an extrapolation method are presented. The performance of the compensation method is shown by the analytic method and the simulation.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.1
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• pp.37-48
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• 2004

The purpose of this study was to evaluate adaptability of external carbon source using GPS-X program in pilot plant composed with 2-stage denitrification process. The result from analysis of pilot plant operation and GPS-X simulation showed that effluent concentration could be simulated similarly by modifying operation conditions, such as DO concentration, C/N ratio and other calibrated parameter. In order to satisfy the standard of the effluent water quality on T-N of 20mg/L, it required approximately 3.1 of C/N ratio and 50% of nitrogen removal efficiency when influent T-N is 36.9mg/L. To maintain the stable water quality of the receiving water, the effluent T-N concentration should be less than 10-15mg/L and the appropriate C/N ratio to remove nitrogen was 4.27-6.82. The analysis of sensitivity to kinetic coefficient and reaction constant showed that $Y_H$ and ${\mu}_{mAUT}$ were most sensitive to nitrate and ammonia nitrogen, relatively and sensitivity coefficient of their were 1.32, 1.98. It was concluded that as $Y_H$ decreased and ${\mu}_{mAUT}$ increased, the reaction rates of denitrification and nitrification increased and the removal efficiencies of $NO_3{^-}-N$ and $NH_4{^+}-N$ improved.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.367-370
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• 2007

Numerous sets of simulation were conducted in order to find out the optimum operational conditions of the existing BNR process using GPS-X program. The model of ASM3 and modified Bio-P module were applied for simulations. From the result of this study, effluent quality was closely related with the step feeding rate and influent C/N ratio. The effluent TN concentration seemed to be significantly affected by step feeding rate at the low C/N condition. But at the high C/N condition, the effluent concentration of TP rather than that of TN was affected by the control of step feeding rate.

• Journal of Korean Society of Disaster and Security
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• v.13 no.2
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• pp.65-75
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• 2020

The efficiency of sewage treatment was ananlyzed selecting a sewage treatment plant in Gyeonggi-do where A₂O process was applied. Statistical techniques based on the operation data of the sewage treatment were used. The main factors directly affecting the efficiency of the treatment process were analyzed using a GPS-X model. The correlation analysis and one-way ANOVA were performed. The T-N and NH₄⁺-N values of the effluent did not generate statistically significant level (p-value:>0.05) when compared with C/N ration values. Removel of nitrogen components form sewage treatment plants were affected by temperature, HRT, SRT and DO. In the case of BOD, all operating factors were affected, while COD was affecte by factors of HRT, STR and DO. In simulations using GPS-X, the parameters that greatly influence was included the maximum sedimentation rate, the dependent nutrient microbial yield (anoxic), the phosphorus saturation coefficient, the dependent nutrient microbial killing rate, the dependent nutrient microbial maximum growth rate, and the independent trophic microorganisms. The maximum growth rate and the maximum setting rate were identified.

• Journal of Wetlands Research
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• v.21 no.3
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• pp.244-250
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• 2019

Due to the industrial development and population growth, it has recently been shown that there are many problems caused by the rinked treatment water in local goverments and sewage treatment plants. The rinked treatment water has a characteristic of low flow rate and high concentration unlike general sewage. These characteristics increase sewage treatment difficulty and sewage treatment fee of sewage treatment facilities. Among the many influencing factors that increase sewage treatment unit cost, 'linked treatment load/design inflow load (%)' was derived as the most correlated factor. Through the selection and modeling of sewage treatment plants, the excess scope of design discharge water quality was investigated under the conditions of temperature and the conditions of 'linked treatment load/design inflow load (%)' taking into account the effects of the four seasons. The study found that for TN, 'linked treatment load/design inflow load (%)' was 19.7%, 22.6%, 25.1%and 27.7%, respectively, under conditions of $5^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$ and $25^{\circ}C$. In case of TP, 'rinked treatment load/design inflow load (%)' was 10.7%, 12.2%, 15.6% and 17.5% at $5^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$, respectively, under conditions of $5^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$ and $25^{\circ}C$.

• Spatial Information Research
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• v.15 no.4
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• pp.363-370
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• 2007

This study has been carried for the development of the basic algorithm of helicopter navigation system based on TRN (Terrain Referenced Navigation) with information input from the GPS. The helicopter determines flight path due to Origination-Destination analysis on the Cartesian coordinate system of 3-D DTM. This system shows 3-D mesh map and the O-D flight path profile for the pilot's acknowledgement of the terrain, at first. The system builds TCF (terrain clearance floor) far the buffer zone upon the surface of ground relief to avid the ground collision. If the helicopter enters to the buffer zone during navigation, the real-time warning message which commands to raise the body pops up using Matlab menu. While departing or landing, control of the height of the body is possible. At present, the information (x, y, z coordinates) from the GPS is assumed to be input into the system every 92.8 m of horizontal distance while navigating along flight path. DTM of 3" interval has been adopted from that which was provided by ChumSungDae Co., Ltd..

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.186-195
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• 2017

Recently, autonomous vehicles have been studied actively. There are various technologies such as ITS, Connected Car, V2X and ADAS in order to realize such autonomous driving. Among these technologies, it is particularly important to recognize where the vehicle is on the road in order to change the lane and drive to the destination. Generally, it is done through GPS and camera image processing. However, there are limitations on the reliability of the positioning due to shaded areas such as tunnels in the case of GPS, and there are limitations in recognition and positioning according to the state of the road lane and the surrounding environment when performing the camera image processing. In this paper, we propose that LED lights should be installed for autonomous vehicles in tunnels which are shaded area of the GPS. In this paper, we show that it is possible to measure the position of the current lane of the autonomous vehicle by analyzing the color temperature after constructing the tunnel LED lighting simulation environment which illuminates light of different color temperature by lane. Based on the above, this paper proposes a lane positioning technique using tunnel LED lights.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.800-808
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• 2008

This paper presents a localization algorithm of the outdoor wheeled mobile robot using the sensor fusion method based on indirect Kalman filter(IKF). The wheeled mobile robot considered with in this paper is approximated to the two wheeled mobile robot. The mobile robot has the IMU and encoder sensor for inertia positioning system and GPS. Because the IMU and encoder sensor have bias errors, divergence of the estimated position from the measured data can occur when the mobile robot moves for a long time. Because of many natural and artificial conditions (i.e. atmosphere or GPS body itself), GPS has the maximum error about $10{\sim}20m$ when the mobile robot moves for a short time. Thus, the fusion algorithm of IMU, encoder sensor and GPS is needed. For the sensor fusion algorithm, we use IKF that estimates the errors of the position of the mobile robot. IKF proposed in this paper can be used other autonomous agents (i.e. UAV, UGV) because IKF in this paper use the position errors of the mobile robot. We can show the stability of the proposed sensor fusion method, using the fact that the covariance of error state of the IKF is bounded. To evaluate the performance of proposed algorithm, simulation and experimental results of IKF for the position(x-axis position, y-axis position, and yaw angle) of the outdoor wheeled mobile robot are presented.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.19-25
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• 2007

Process analysis with ASM3 (Activated Sludge Model3) was performed to offer basic data for the optimization of aerated biofilter (ABF) process design and operation. This study was focused on the simulation of the nitrification reaction in ABF which was a part of the advanced nutrient treatment process using bio-adsorption. The ABF process has been developed for the removal of suspended solids and nitrification reaction in sewage. A GPS-X (General Purpose Simualtor-X) was used for the sensitivity analysis and operation assessment. Sensitivity of ASM3 parameters on ABF was analysed and 4 major parameters ($Y_A$, $k_{sto}$, ${\mu}_A$, $K_{A,HN}$) were determined by dynamic simulation using 70 days data from pilot plant operation. The optimized values were 0.14 for $Y_A$, 3.5/d for $k_{sto}$, 2.7/d for ${\mu}_A$ and 1.1 mg/L for $K_{A,HN}$, respectively. Simulation with optimized parameter values were conducted and TN, $NH_4{^+}-N$ and $NO_3{^-}-N$ concentrations were estimated and compared with measured data at the range of 10 min to 4 hrs of hydraulic retention time (HRT). The simulated results showed that optimized parameter values could represent the characteristics of ABF process. Especially, the ABF showed relatively high nitrification rate (60%) under very short HRT of 10 min. As a consequence, the ABF was thought to be successfully used in the site which having high variation of influent loading rate.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.309-313
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• 2007

In Activated Sludge Model, COD fraction of primary settled municipal wastewater was a very important parameter. In this study, the COD fraction was determined using the oxygen utilization rate experiments. Readily biodegradable COD ($S_S$) fraction was observed about 29.7% of influent TCOD. $S_I$, $X_I$, and $X_S$ were analyzed to be 7.6%, 7.3%, and 55.4% of TCOD, respectively. The model used in this study was developed based on ASM3 and modified Bio-P module in order to simulate the existing BNR process. Parameter estimation results showed that $Y_{STO,O2}$, $Y_{STO,NO}$, $Y_{H,O2}$, $Y_{H,NO}$, $Y_{PO4}$, ${\mu}_H$, $b_H$, ${\mu}_A$, $q_{PHA}$, $q_{PP}$ and ${\mu}_{PAO}$ were 0.7, 0.64, 0.61, 0.48, 0.31, 3.9, 0.1, 1.35, 4.98, 1.8 and 0.59, respectively. Using the presented model and the estimated parameters, the simulation of the existing BNR process was successfully conducted.