• Journal of Korean Society for Atmospheric Environment
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• v.27 no.5
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• pp.580-602
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• 2011

Volatile organic compound (VOC) emissions in the 2007 CAPSS (Clean Air Protection Supporting System) emissions inventory are chemically speciated for the SAPRC99 (Statewide Air Pollution Research Center 99) mechanism, following the Source Classification Code (SCC) matching method to borrow the U.S.EPA's chemical speciation profiles. CMAQ simulations with High-order Direct Decoupled Method (HDDM) are in turn applied to evaluate uncertainty in the method by comparing the simulated model VOC species to the observations in the Seoul Metropolitan Area (SMA) for a 2007 June episode. Simulations under-predicted ALK1 to ALK4 in SAPRC99 by a factor of 2 to 5 and over-predicted ALK5 by a factor of 7.5 while ARO1, ARO2, OLE1, and ethylene (ETH) are comparable to the observations, showing relative difference by 10 to 30%. OLE2 emissions are roughly 4 times overestimated. Emission rates for individual VOC model species are revised referring to the ratio of simulated to observed concentrations. Impact of the VOC emission changes on the overall ozone prediction was insignificant for the days of which 1-hr maximum ozone are lower than 100 ppb. However, simulations showed ozone difference by 5 to 10 ppb when high ozone above 120 ppb was observed in the vicinity of Seoul. This result suggests that evaluations on individual model VOC emissions be necessary to lead ozone control plans to the right direction. Moreover, the simulated ratios of ARO1 and ARO2 to $NO_x$ are roughly 50% lower than the observed ones, which imply that adjustment in $NO_x$ and VOC emission rates may be required to mimic the real VOC/$NO_x$ condition over the area.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.123-128
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• 2018

In this paper, we propose a multi-vehicle object detection algorithm using feature point matching that tracks efficient vehicle objects. The proposed algorithm extracts the feature points of the vehicle using the FAST algorithm for efficient vehicle object tracking. And True if the feature points are included in the image segmented into the 5X5 region. If the feature point is not included, it is processed as False and the corresponding area is blacked to remove unnecessary object information excluding the vehicle object. Then, the post processed area is set as the maximum search window size of the vehicle. And A minimum search window using the outermost feature points of the vehicle is set. By using the set search window, we compensate the disadvantages of the search window size of mean-shift algorithm and track vehicle object. In order to evaluate the performance of the proposed method, SIFT and SURF algorithms are compared and tested. The result is about four times faster than the SIFT algorithm. And it has the advantage of detecting more efficiently than the process of SUFR algorithm.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.4
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• pp.418-428
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• 2002

In this paper, we propose a motion-adaptive de-interlacing method using motion compensated interpolation. In a conventional motion compensated method, a simple pre-filter such as line averaging is applied to interpolate missing lines before the motion estimation. However, this method causes interpolation error because of inaccurate motion estimation and compensation. In the proposed method, EBMF(Edge Based Median Filter) as a pre-filter is applied, and new matching method, which uses two same-parity fields and opposite-parity field as references, is proposed. For further improvement, motion correction filter is proposed to reduce the interpolation error caused by incorrect motion. Simulation results show that the proposed method provides better performance than existing methods.

• KIISE Transactions on Computing Practices
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• v.21 no.2
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• pp.138-143
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• 2015

The Boyer-Moore algorithm is a single pattern string matching algorithm that is widely used in various applications such as computer and internet security, and bioinformatics. This algorithm is computationally demanding and requires high-performance parallel processing. In this paper, we propose a parallelization and performance optimization methodology for the BM algorithm on a GPU. Our methodology adopts an algorithmic cascading technique. This results in significant reductions in the mapping overheads for the threads participating in the parallel string matching. It also results in the efficient utilization of the multithreading capability of the GPU which improves the load balancing among threads. Our experimental results show that this approach achieves a 45-times speedup at maximum, in comparison with a serial execution.

• Korean Journal of Remote Sensing
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• v.27 no.4
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• pp.411-420
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• 2011

In this study, a digital elevation model (DEM) in tidal flat of Suncheon Bay, one of the most ecological preserved area in the world, was generated from digital aerial stereo-images. The focal lengths for the aerial stereo-images were adjusted using ground control points (GCPs) in order to improve the accuracy of camera parameters. We proposed matching sizes suitable for generating DEM in tidal flat and a method for eliminating excessive position errors using intersection-distance($P_R$) threshold value. The accuracies of the DEM generated from the proposed method as well as the commercial S/W were compared with the elevation profiles measured by Total Station in the filed. As the results, the DEM generated by the proposed method showed better result (maximum deviation is a -21 centimeters) with detailed topography than DEM by the commercial S/W in the region. These results suggest that the DEM of tidal flat, which hardly obtained with the traditional methods, can be generated from digital aerial images by applying the proposed method in this study. We believe that the generated DEM in tidal flat can be an essential data for monitoring the sediment erosion and deposit of the tidal flat.

• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.408-412
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• 1998

As the radius of curvature of curved optical waveguide gets smaller, the loss increases at the junction of linear-curved waveguide by the cross sectional mode mismatch. The concept of lateral offset has been used widely to minimize it, and simple method of maximum matching has been efficient for most cases of silica waveguide with low optical confinement and large radius of curvature. Here, we analyzed that the propagation mode characteristics of the lateral offset and propagation mode characteristics of general case with effective index method and Airy function solution. As the normalized frequency varies, mode characteristics changes near the boundary of 1/V=0.7 and the simple matching of gaussian profile might give -35% of error at most. We proposed improved method with a new correction factor to improve the mode mismatch problem of conventional methods for general cases, and showed the convenience and feasibility of this method for the calculation of the lateral offset.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.630-639
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• 1998

In this paper, a T-shaped microstrip feed line is proposed for a better impedance matching to the microstrip slot antenna in a various range of slot widths. It was found that the bandwidth of this antenna is proportional to the slot width. It was also found that the radiation resistance of this feed line structure is quite constant and low regardless to the slot width. A slot antenna with T-shaped microstrip feed line is analyzed by using the FDTD method. At first, the propagation process of the reflected wave and the electric field distribution in the time domain is calculated respectively. The antenna parameters also are optimized to get maximum band width, return loss, input impedance, and radiation pattern in the frquency domain by Fourier transforming the time domain results. From the computed results, the optimum slot antenna is designed and fabricated. When the slot width is 16 mm, approximately 35% of bandwidths are obtained without a matching circuit. These computed results using FDTD method were in relatively good accordance with the measured values.

• Journal of Korea Game Society
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• v.18 no.1
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• pp.125-134
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• 2018

This paper presents a practical method to efficiently extract the rotational part of a $3{\times}3$ matrix that changes continuously in time. This is the key technique in the corotational FEM and the shape matching deformation popular in physics-based dynamic deformation. Recently, in contrast to the traditional polar decomposition methods independent of time, an iterative method was proposed that formulates the rotation extraction in a physics-based way and exploits an incremental representation of rotation. We develop an optimization method that reduces the number of iterations under the assumption that the maximum magnitude of the incremental rotation vector is limited within ${\pi}/2$. Realistic simulation of dynamic deformation employs a sufficiently small time step, and thus this assumption is not problematic in practice. We demonstrate the efficiency and practicality of our method in various experiments.

• Journal of Intelligence and Information Systems
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• v.8 no.2
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• pp.1-13
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• 2002

In this paper, we propose an object tracking system which can be convinced of moving area shaped on objects through color sequential images, decided moving directions of foot messengers or vehicles of image sequences. In static camera, we suggests a new evaluating method extracting co-occurrence matrix with feature vectors of RGB after analyzing and blocking difference images, which is accessed to field of camera view for motion. They are energy, entropy, contrast, maximum probability, inverse difference moment, and correlation of RGB color vectors. we describe how to analyze and compute corresponding relations of objects between adjacent frames. In the clustering, we apply an algorithm of FCM(fuzzy c means) to analyze matching and clustering problems of adjacent frames of the featured vectors, energy and entropy, gotten from previous phase. In the matching phase, we also propose a method to know correspondence relation that can track motion each objects by clustering with similar area, compute object centers and cluster around them in case of same objects based on membership function of motion area of adjacent frames.

• Resources Recycling
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• v.9 no.6
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• pp.31-35
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• 2000

The complex permeability, the complex permittivity and the reflection loss are investigated in the composite microwave absorbers which are mixed with the wasted Mn-Zn ferrite and the industrial cement. The cement has larger the complex permittivity than that of the rubber. The complex permittivity is decreasing with the increment of the mixing ratio of Mn-Zn ferrite to cement (F/C in weight) and the complex permeability is increasing with the increment of F/C. The maximum reflection loss is above -40 dB at all samples. The matching frequency is in the range of 1.3 GHz to 2.9 GHz and is decreasing with the increment of F/C from 1 to 3. The matching thickness is increasing with the increment of F/C. The wasted Mn-Zn ferrite and the cement is very useful material for the composite microwave absorber.