• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.127-136
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• 2007

An abrupt scene-change frame is one that is hardly correlated with the previous frames. In that case, because an intra-coded frame has less distortion than an inter-coded one, almost all macroblocks are encoded in intra mode. This breaks up the rate control flow and increases the number of bits used. Since the reference software for H.264 takes no special action for a scene-change frame, several studies have been conducted to solve the problem using the quadratic R-D model. However, since this model is more suitable for inter frames, the existing schemes are unsuitable for computing the QP of the scene-change intra frame. In this paper, an improved rate control scheme accounting for the characteristics of intra coding is proposed for scene-change frames. The proposed scheme was validated using 16 test sequences. The results showed that the proposed scheme performed better than the existing H.264 rate control schemes. The PSNR was improved by an average of 0.4-0.6 dB and a maximum of 1.1-1.6 dB. The PSNR fluctuation was also in proved by an average of 18.6 %.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.159-165
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• 2012

This paper deals with the performance comparison of adaptive equalization algorithm, MMA and SCA, that is used for the minimization of the distortion and noise effect in the communication channel.. The transmitting signal will be distorted and received due to the nonlinearties of magnitude and phase transfer characteristics of communication channel, the compensation of it by using the self adaptive equalizer. The constant modulus has important metric in the self adaptive equalizer, the MMA uses the 2nd and 4th high order statistics of transmitting signal, the SCA uses the 2nd order statistics of transmitting signal only in order to the calculation of it. We compared to the compensation performance of the MMA and SCA by the computer simulation that are possible to the compensation of the two kinds of transfer characteristics at same times by the relatively simple arithmatic operation. We used to the recovered constellation, residual isi and MSE, SER that are the essential index for the comparison of the adaptive equalizer. The result of performance comparison of algorithms, the MMA which uses the high order statistics of transmitting signal has good performance in the MSE and SER compared to the SCA which is using the low order statistics. But in the recovered costellation and residual isi, the SCA has a good than the MMA.

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.149-160
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• 2015

This paper suggests the MMAS(Map Matching using Additional Surveying) method to improve the cadastral discrepancy search algorithm that currently does not include corrections of mis-represented parcel data. The MMAS is a method to search for cadastral discrepancy after correcting mis-represented parcel data using nearby anchor points confirmed by surveys. The MMAS first transforms the coordinate system of the digital cadastral map by overlaying anchor points obtained in the field surveying process over the corresponding edges of buildings and facility points on the digital topographic map. Then, it searches for cadastral discrepancy by checking if the area differences exceed the tolerance limit. This method improves the current method for searching for cadastral discrepancy by performing the process after correcting extortion of the digital cadastral map. This helps to identify cadastral discrepancies that are not detectable within the distorted digital cadastral map. With our experiment, this method identified more discrepancies compared to the method without the correcting the distortion of the digital cadastral map. We believe this method will be able to help the national cadastral re-survey by identifying potential cadastral discrepancy more accurately.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.438-448
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• 2016

This study was conducted to identify factors influencing the weight control behavior of college students. The subjects included college students in the C area, and data were collected through a self reported structured questionnaire from Dec 01 to 20 of 2015. Overall, 289 subjects were analyzed. Analyses consisted of descriptive statistics, t-tests, ANOVA, Pearson's correlation analysis, and stepwise multiple regression analysis. The findings showed a prominent distortion of college students' perceptions of their bodies based on evaluation by others and obesity stress, which had special impacts on their weight control behavior. Weight control behavior, body self-awareness (r=.31, p<0.001), assessment of body by others (r=.30, p<0.001), and obesity stress (r=.43, p<0.001) were closely related to their weight control behavior. Stepwise multiple regression revealed that their weight control behavior was closely influenced by obesity stress (${\beta}=.37$, p<0.001) and assessment of body by others (${\beta}=.15$, p=0.009). These variables accounted for 20% of the weight control behavior (F=37.30, p<0.001). Overall, assessment of body by others and obesity stress were found to be predictors of their weight control behavior. These findings indicate that it is necessary to develop and implement information programs and design appropriate prevention programs that can induce healthy weight control behaviors. Such programs should include health education, as well as intervention programs to identify such predictors and help college students judge and perceive their body shapes objectively so that they control their weight in a proper manner.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.453-464
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• 2019

Recently, as the demand for 3D geospatial information increases, the importance of rapid and accurate data construction has increased. Although many studies have been conducted to register UAV (Unmanned Aerial Vehicle) imagery based on LiDAR (Light Detection and Ranging) data, which is capable of precise 3D data construction, studies using LiDAR data embedded in MMS (Mobile Mapping System) are insufficient. Therefore, this study compared and analyzed 9 matching algorithms based on feature points for registering reflectance image converted from LiDAR point cloud intensity data acquired from MMS with image data from UAV. Our results indicated that when the SIFT (Scale Invariant Feature Transform) algorithm was applied, it was able to stable secure a high matching accuracy, and it was confirmed that sufficient conjugate points were extracted even in various road environments. For the registration accuracy analysis, the SIFT algorithm was able to secure the accuracy at about 10 pixels except the case when the overlapping area is low and the same pattern is repeated. This is a reasonable result considering that the distortion of the UAV altitude is included at the time of UAV image capturing. Therefore, the results of this study are expected to be used as a basic research for 3D registration of LiDAR point cloud intensity data and UAV imagery.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.455-461
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• 2013

Kompsat-3 is an optical high-resolution earth observation satellite launched in May 2012. The AEISS sensor of the Korean satellite provides 0.7m panchromatic and 2.8m multi-spectral images with 16.8km swath width from the sun-synchronous near-circular orbit of 685km altitude. Kompsat-3 is more advanced than Kompsat-2 and the improvements include better agility such as in-track stereo acquisition capability. This study investigated the characteristic of the epipolar curves of in-track Kompsat-3 stereo images. To this end we used the RPCs(Rational Polynomial Coefficients) to derive the epipolar curves over the entire image area and found out that the third order polynomial equation is required to model the curves. In addition, we could observe two different groups of curve patterns due to the dual CCDs of AEISS sensor. From the experiment we concluded that the third order polynomial-based RPCs update is required to minimize the sample direction image distortion. Finally we carried out the experiment on the epipolar resampling and the result showed the third order polynomial image transformation produced less than 0.7 pixels level of y-parallax.

• Journal of Korea Multimedia Society
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• v.7 no.2
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• pp.173-186
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• 2004

This paper proposed the content-based retrieval system as a method for performing image retrieval through the effective feature extraction of the object of significant meaning based on the characteristics of man's visual system. To allow the object region of interest to be primarily detected, the region, being comparatively large size, greatly different from the background color and located in the middle of the image, was judged as the major object with a meaning. To get the original features of the image, the cumulative sum of tile declination difference vector the segment of the object contour had and the signature of the bipartite object were extracted and used in the form of being applied to the rotation of the object and the change of the size after partition of the total length of the object contour of the image into the normalized segment. Starting with this form feature, it was possible to make a retrieval robust to any change in translation, rotation and scaling by combining information on the texture sample, color and eccentricity and measuring the degree of similarity. It responded less sensitively to the phenomenon of distortion of the object feature due to the partial change or damage of the region. Also, the method of imposing a different weight of similarity on the image feature based on the relationship of complexity between measured objects using the fractal dimension by the Boxing-Counting Dimension minimized the wrong retrieval and showed more efficient retrieval rate.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.33-42
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• 1988

The abdominal tumors in children are different from those of adult. These tumors are the third most common one, preceded by leukemia and brain tumors, in children under 15 years. X-ray examination is the most important method among diagnostic approaches. The role of diagnostic imaging is to identify the precise anatomic location and extent of pathologic process with the minimal number of imaging procedures. 23 cases of abdominal tumors were reviewed in respect of age incidence, site of origin, radiologic findings. The results are briefly summarized as follows : 1. Neuroblastoma was the most common(6 cases) and wi1m's tumor(5 cases), choledocal cyst(4 cases), ovarian mass(3 cases), hydronephrosis(2 cases), were descending order in frequency. 2. The most common site was retroperitoneum(60%). Kidney was the single most common site of origin. 3. Radiologic findings. The most common findings of plain radiography was ill defined soft tissue mass and this method was helpful in the presence of calcification especially in neuroblastoma. Ultrasonographic pattern was anechoic(cystic), echoic or mixed pattern, but this method provide less precise anatomical details, nevertheless ultrasonography wes paticullary useful imaging modality for the pediatric abdominal tumors. IVP findings were renal displacement, caliceopelvic system distortion or nonvisualization of kidney, these information was helpful in determining the location of tumors. CT scan showed homogenous or inhomogenous, cystic or solid, mass with their anatomic location. 4. Ultrasonography was the most widely used specific diagnostic method, but had limited value in detecting the anatomic location of tumors. CT scan was superior to ultrasound for determining the extent of tumors.

• Journal of Biosystems Engineering
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• v.41 no.2
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• pp.126-137
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• 2016

Purpose: The overall objective of this study was to evaluate the vegetation fraction of soybeans, grown under different cropping conditions using an unmanned aerial vehicle (UAV) equipped with a red, green, and blue (RGB) camera. Methods: Test plots were prepared based on different cropping treatments, i.e., soybean single-cropping, with and without herbicide application and soybean and barley-cover cropping, with and without herbicide application. The UAV flights were manually controlled using a remote flight controller on the ground, with 2.4 GHz radio frequency communication. For image pre-processing, the acquired images were pre-treated and georeferenced using a fisheye distortion removal function, and ground control points were collected using Google Maps. Tarpaulin panels of different colors were used to calibrate the multi-temporal images by converting the RGB digital number values into the RGB reflectance spectrum, utilizing a linear regression method. Excess Green (ExG) vegetation indices for each of the test plots were compared with the M-statistic method in order to quantitatively evaluate the greenness of soybean fields under different cropping systems. Results: The reflectance calibration methods used in the study showed high coefficients of determination, ranging from 0.8 to 0.9, indicating the feasibility of a linear regression fitting method for monitoring multi-temporal RGB images of soybean fields. As expected, the ExG vegetation indices changed according to different soybean growth stages, showing clear differences among the test plots with different cropping treatments in the early season of < 60 days after sowing (DAS). With the M-statistic method, the test plots under different treatments could be discriminated in the early seasons of <41 DAS, showing a value of M > 1. Conclusion: Therefore, multi-temporal images obtained with an UAV and a RGB camera could be applied for quantifying overall vegetation fractions and crop growth status, and this information could contribute to determine proper treatments for the vegetation fraction.

• Environmental and Resource Economics Review
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• v.13 no.2
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• pp.271-300
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• 2004

We investigate the two recent simulations of the proto-type domestic carbon emission trading system in Korea and draw some policy implications. The first simulation includes the 5 electric power companies based on baseline and credit. But the second one is with the 7 energy-intensive companies based on cap and trade. The voluntary approaches in this paper revealed the instability of market equilibrium, i.e., price volatility or distortion, excess supply or demand. These phenomena stems from excess incentives to the players, asymmetric information, players' irresponsible strategic behaviors, and non acquaintance of trading system. This paper suggests the basic design for domestic carbon trading system in future and a stepwise introduction strategy for it including the incentive auction scheme, the total quantity of incentive needed, and how to finance it. Meantime, the further simulations on the various sectors based on voluntary participation must be essential for learning experiences and better policy design.