• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.159-162
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• 2008

This paper presents a modified mean curvature diffusion filter to smooth speckle noise in images. Mean curvature diffusion filter has already shown good results in reducing noise in images while preserving fine details. In the mean curvature diffusion, the rate of smoothing is controlled by the local value of the diffusion coefficient chosen to be a function of the local image gradient magnitude. In this paper, the diffusion coefficient is modified to be controlled adaptively by local image surface slope and heterogeneity. The local surface slope contributes to preserving details (e.g.edges) in image and the local surface heterogeneity helps the smoothing filter consider the amount of noise in both edge and non-edge area. The proposed filter's performance is demonstrated by quantitative experiments using speckle noised aerial image and TerraSAR-X satellite image.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.521-526
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• 2009

In this paper, a complex-valued recursive least squares escalator filter algorithm with reduced computational complexity for complex-valued signal processing applications is presented. The local tap weight of RLS-ESC algorithm is updated by incrementing its old value by an amount equal to the local estimation error times the local gain scalar, and for the gain scalar, the local input autocorrelation is calculated at the previous time. By deriving a new gain scalar that can be calculated by using the current local input autocorrelation, reduced computational complexity is accomplished. Compared with the computational complexity of the complex-valued version of RLS-ESC algorithm, the computational complexity of the proposed method can be reduced by 50% without performance degradation. The reduced computational complexity of the proposed algorithm is even less than that of the LMS-ESC. Simulation results for complex channel equalization in 64QAM modulation schemes demonstrate that the proposed algorithm has superior convergence and constellation performance.

• Journal of information and communication convergence engineering
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• v.21 no.1
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• pp.62-67
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• 2023

This paper proposes an imputation method using a bidirectional k-nearest components search based local linear regression method. The bidirectional k-nearest-components search method selects components in the dynamic range from the missing points. Unlike the existing methods, which use a fixed-size window, the proposed method can flexibly select adjacent components in an imputation problem. The weight values assigned to the components around the missing points are calculated using local linear regression. The local linear regression method is free from the rank problem in a matrix of dependent variables. In addition, it can calculate the weight values that reflect the data flow in a specific environment, such as a blackout. The original missing values were estimated from a linear combination of the components and their weights. Finally, the estimated value imputes the missing values. In the experimental results, the proposed method outperformed the existing methods when the error between the original data and imputation data was measured using MAE and RMSE.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.373-379
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• 2012

This paper presents a fault location algorithm based on the adaptively estimated value of the local sequence source impedance for faults on a parallel transmission line. This algorithm uses only the local voltage and current signals of a faulted circuit. The remote current signals and the zero-sequence current of the healthy adjacent circuit are calculated by using the current distribution factors together with the local terminal currents of the faulted circuit. The current distribution factors consist of local equivalent source impedance and the others such as fault distance, line impedance and remote equivalent source impedance. It means that the values of the current distribution factors can change according to the operation condition of a power system. Consequently, the accuracy of the fault location algorithm is affected by the two values of equivalent source impedances, one is local source impedance and the other is remote source impedance. Nevertheless, only the local equivalent impedance can be estimated in this paper. A series of test results using EMTP simulation data show the effectiveness of the proposed algorithm. The proposed algorithm is valid for a double-circuit transmission line system where the equivalent source impedance changes continuously.

• Journal of the Korean Regional Science Association
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• v.13 no.2
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• pp.143-155
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• 1997

This study aims at drawing implications for Korea's urban growth management policies from U.S.A's experience on this issue. This study analyzes two types of contradictions in planning and implementing urban growth management policies: 1) value conflicts in goal setting and 2) contradictions among different level of governments (local, province, nation). As mentioned by Campbell (1996), there are three types of conflicts in objective values (efficiency, equity, and environment protection): property contradiction between economic growth and equity, resource conflict between efficiency and environment protection, and development conflict between equity and environment protection in urban growth management policies. In implementing urban growth management three types of conflicts in goal values should been taken into consideration. Contradictions among local governments, province, and central government are also found in implementing growth management policies. The lessons from the United State are as follow: 1) growth management plans are initiated by the local government and during the planning process adjacent local governments review a local government's growth management plans and give inputs for the plan, 2) local government and State work together for growth management planning and specially, the State provides technical and financial assistance to local government, and 3) the State plays leading roles in local government's planning and implementing of growth management policies with carrot and stick policy.

• Journal of Fashion Business
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• v.14 no.5
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• pp.158-175
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• 2010

Culture means a lifestyle realizing a definite object or ideal. Each local special culture is enormous in value as a local culture inheritance. If it is developed a local culture products representing local culture, it can perform an important role on one of the strategies for revitalizing local economy. One of the typical cultures in Kyung-Nam is the Gaya culture. The most characteristic of the Gaya culture is powerful iron culture and lots of cultural properties have been founding as relics. Judging from a lot of iron relics, we can figure out a high level of iron manufacturing technology. I studied focussing on the plasticity of Gaya relics and collected base materials for developing local cultural goods, using the motif of Gaya culture with excellent aesthetic consciousness. I classfied Gaya relics into a crown style, jewelry, harnessry, weapons, armor, earthenware, and considered its characteristic of the plastic arts, based on the preceding studies and document data. There exists natural, moderate, polished, indigenous, simple, rhythmical, delicate, florid, technical, symbolical, strong, diverse, naive beauty in the plastic characteristic of Gaya relics. Gaya culture with the special excellence of aesthetic resources, is worthy enough to be recreated as local cultural goods. Variable and special cultural fashion-products with the distinctive feature of Gaya culture need to be developed without delay.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.10-20
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• 2022

Objectives: The aim of this study is to evaluate exposure levels of the extremely low frequency magnetic fields(ELF-MF) radiated from various electric facilities in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the exposure levels of personal and local ELF-MF for the electronic facilities installed in two LCD manufacturing companies. Samplers were installed around workers' waist during working hours to identify personal exposure levels, and direct reading equipment were located at 3 cm, 10 cm, and 30 cm away from the surface of the electronic facilities to measure local exposure levels. Average and maximum(ceiling) values were calculated for personal and local exposure levels. Results: Average and maximum of personal exposure levels for each worker were 0.56(mean) ± 0.02(SE) µT and 6.31 ± 0.75 µT, respectively. Statistical analyses of the study found that maximum of the personal exposure levels for engineers was significantly higher than that for operators since engineers spend more time near the electronic facilities for repairing. The range of maximum personal exposure levels was 0.50 ~ 43.50 µT and its highest level was equivalent to 4.35 % of ACGIH(American Conference of Governmental Industrial Hygienists) exposure limit value(1 mT). Maximum of local exposure levels was 8.18 ± 0.52 µT and the electronic facilities with higher exposure levels were roof rail and electric panel, which were not related to direct manufacturing. The range of maximum local exposure levels was 0.60 ~ 287.20 µT and its highest level was equivalent to 28.7 % of the ACGIH exposure limit value. Lastly, the local exposure levels significantly decreased as the measurement distance from the electronic facilities increased. Conclusions: Maximum of personal and local exposure levels did not exceed the exposure limit value of ACGIH. However, it is recommended to keep the workers as far as possible from the sources of ELF-MF.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.11
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• pp.928-937
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• 2013

This paper presents a novel contrast enhancement method based on singular value decomposition and image pyramid. The proposed method consists mainly of four steps. The proposed algorithm firstly decomposes image into band-pass images, including basis image and detail images, to improve both the global contrast and the local detail. In the global contrast process, singular value decomposition is used for contrast enhancement; the local detail scheme uses weighting factors. In the final image composition process, the proposed algorithm combines color and luminance components in order to preserve the color consistency. Experimental results show that the proposed algorithm improves contrast performance and enhances detail compared to conventional methods.

• Radiation Oncology Journal
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• v.37 no.1
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• pp.30-36
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• 2019

Purpose: This study aimed to identify the feasibility of the maximum standardized uptake value (SUVmax) on baseline 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) as a predictive factor for prognosis in early stage primary lung cancer treated with stereotactic body radiotherapy (SBRT). Materials and Methods: Twenty-seven T1-3N0M0 primary lung cancer patients treated with curative SBRT between 2010 and 2018 were retrospectively evaluated. Four patients (14.8%) treated with SBRT to address residual tumor after wedge resection and one patient (3.7%) with local recurrence after resection were included. The SUVmax at baseline PET/CT was assessed to determine its relationship with prognosis after SBRT. Patients were divided into two groups based on maximum SUVmax on pre-treatment FDG PET/CT, estimated by receiver operating characteristic curve. Results: The median follow-up period was 17.7 months (range, 2.3 to 60.0 months). The actuarial 2-year local control, progression-free survival (PFS), and overall survival were 80.4%, 66.0%, and 78.2%, respectively. With regard to failure patterns, 5 patients exhibited local failure (in-field failure, 18.5%), 1 (3.7%) experienced regional nodal relapse, and other 2 (7.4%) developed distant failure. SUVmax was significantly correlated with progression (p = 0.08, optimal cut-off point SUVmax > 5.1). PFS was significantly influenced by pretreatment SUVmax (SUVmax > 5.1 vs. SUVmax ≤ 5.1; p = 0.012) and T stage (T1 vs. T2-3; p = 0.012). Conclusion: SUVmax at pre-treatment FDG PET/CT demonstrated a predictive value for PFS after SBRT for lung cancer.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.39-51
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• 2023

This study uses the hedonic price approach to estimate the economic value of a parking lot in an apartment building. In this study, a logarithmic function was applied to estimate the price elasticity of parking spaces. Variables were composed of an independent variable (apartment house characteristics) and a dummy variable (external characteristics). Detailed variables include exclusive area, number of floors, waterproofing, number of bathrooms, and number of parking spaces per household. Based on the results of the analysis for the entire year, the increase in the number of parking spaces affects a price increase of approximately 25.97 million won to 59.68 million won, which can be interpreted as the economic value of the parking space. However, since Hanam City was specified in this study, there is a limit to generalizing the current results and using them for project evaluation.