• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.1036-1043
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• 2005

In this paper, we propose a sequential motion vector recovery algorithm for H.264 video coding standard. Motion vectors of H.264 video coding standard cover relatively smaller areas than other standard, since motion estimation of H.264 takes place in the fashion of variable block size. Therefore, the correlation of motion vectors between neighboring blocks increases as the block size of motion estimation is lowered. Under the framework of sequential recovery, we introduce a motion vector recovery using $\alpha$-trimed mean filter. Experimental results show that proposed algorithm is useful in real time video delivery .with nearly comparable or better visual quality than previous approaches such as macro block boundary matching and Lagrage interpolation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1015-1022
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• 2007

In this paper, we proposed a wideband design of planar inverted-F antenna(PIFA) using two-layer, patches and modified ground structure. The antenna consists of two layer patches with common feed and modified ground plane to control resonance frequency and antenna input impedance. The measured bandwidth is 1,492 MHz(BW: 67.7 %, 1,457${\sim}2,949$ MHz) for VSWR<2, and 1,170 MHz(BW: 21 %, 4,970${\sim}$6,140 MHz) for VSWR<2.5. It covers service bands of DCS1800, DCS1900, UMTS(WCDMA), WiBro, WLAN(IEEE 802.11b), satellite DMB. WLAN(IEEE 802.11a) in Korea and radiation patterns shows constant figure with frequency change.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.29-36
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• 2012

In this paper, we suggest a new method of detecting human skin-color regions from three-dimensional static or dynamic stereoscopic images by effectively integrating depth and color features. The suggested method first extracts depth information that represents the distance between a camera and an object from input left and right stereoscopic images through a stereo matching technique. It then performs labeling for pixels with similar depth features and determines the labeled regions having human skin color as actual skin color regions. Our experimental results show that the suggested skin region extraction method outperforms existing skin detection methods in terms of skin-color region extraction accuracy.

• Journal of the Korean Data and Information Science Society
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• v.23 no.3
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• pp.419-446
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• 2012

National statistical system in Korea has developed along with national economic agenda such as a government oriented high economic growth and has formed to a typical diversified statistical system. While the national statistics have been produced whenever they are needed, they are facing the critics that production of basic statistics were lack of balance. Grasping the statistical demand properly, enhancing the statistical concurrence with international organization, preventing the production of overlapped and similar statistics, and improving the professionalism of manpower in statistical industry are the structural problems that Korean statistical system has to get over. It is important to strengthen the coordination mechanism and the governance structure of the national statistical system to level up the integrity and credibility of statistical program. The length of Chief Statistician's tenure need to be assured.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.65-73
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• 2013

As the advent of the digital age, documents are often scanned to be archived or to be transmitted over the network. The largest proportion of documents is texts and the next is seal images indicating the author of the documents. While a lot of research has been conducted to recognize texts in scanned documents and commercialized text recognizing products are developed as highlighted the importance of the scanned document, information about seal images is discarded. In this paper, we study how to extract the seal image area from the color or black and white document containing the seal image and how to save the seal image. We propose a preprocessing step to remove other components except for the candidate outlines of the seal imprint from scanned documents and a method to select the final region of interest from these candidates by using the feature of seal images. Also in case of a seal imprint overlapped with texts, the most similar image among those stored in the database is selected through the template matching process. We verify the implemented system for a various type of documents produced in schools and analyze the results.

• Smart Media Journal
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• v.10 no.3
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• pp.23-30
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• 2021

Although the manufacturing time series data clustering technique is an important grouping solution in the field of detecting and improving manufacturing large data-based equipment and process defects, it has a disadvantage of low accuracy when applying the existing static data target clustering technique to time series data. In this paper, an evolutionary computation-based time series cluster analysis approach is presented to improve the coherence of existing clustering techniques. To this end, first, the image shape resulting from the manufacturing process is converted into one-dimensional time series data using linear scanning, and the optimal sub-clusters for hierarchical cluster analysis and split cluster analysis are derived based on the Pearson distance metric as the target of the transformation data. Finally, by using a genetic algorithm, an optimal cluster combination with minimal similarity is derived for the two cluster analysis results. And the performance superiority of the proposed clustering is verified by comparing the performance with the existing clustering technique for the actual manufacturing process image.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.2
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• pp.29-40
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• 2007

The purpose of this research is to propose a method for scoring the quality of a fingerprint image using the local information derived from the fingerprint image. In previous works for the quality measuring, most of the quality scores are related to the performance of a matching algorithm, and this makes the quality result more subjective. The quality score of a fingerprint image proposed in this work is sensor-independent, source-independent and matcher-independent one, and this concept of fingerprint sample quality results in effective improvement of the system performance. In this research, a new definition of fingerprint image quality and a new method for measuring the quality are proposed. For the experiments, several sub-databases from FVCs are used and the proposed method showed reasonable results for the test database. The proposed method can be used in various systems for the numerous purposes since the quality scores generated by the proposed method are based on the idea that the quality of fingerprint should be sensor-independent, source-independent and matcher-independent.

• The Journal of the Acoustical Society of Korea
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• v.41 no.2
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• pp.242-253
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• 2022

When the source waveform is unknown, the Green's function can be estimated by Ray-based Blind Deconvolution (RBD) based on the simple array signal processing. In previous papers, RBD was successfully demonstrated using simulation and experiments in shallow water environment. In this paper, we investigate the applicability of RBD for a long-range communication (e.g., 30 km, 60 km, and 90 km) in a deep water environment (1,000 m ~), using experimental data conducted in the east of Pohang, South Korea, in October 2018. Data results are presented to demonstrate Green's function estimation of a communication signal (2.2 kHz ~ 2.9 kHz) using a 16-element, 42-m long vertical array. The results show that the Green's function estimated from RBD is comparable to that of matched filter result. Additional communication performance at a maximum range of 90 km will be also presented.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.379-389
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• 2024

Purpose and Method: Crowed Events can lead to sudden accidents caused by unpredictable variables. Therefore, focusing on the '10.29 Itaewon accident' among the representative cases, we examined the accident as the process of occurrence. In addition, improvement measures were suggested through analysis of related legal systems. Result: In the Itaewon accident, a "colony wave phenomenon" occurred due to "ultra-high-density cluster stay". In addition, cluster destruction occurred from a weak location in the cluster due to clusters and pressures in different directions to avoid this. Looking at the laws related to the safety management of Crowed Events, the laws and regulations differ depending on the location and type. Due to the complementary nature of the approach to the legal blind spot, the legal system that uses similar terms of the same concept and is not systematic is causing uncertainty in the application and interpretation of the law. Conclusion: Crowd control and on-site management should be carried out for events when the cluster density is expected to reach 8 people/m² or reached. Consistency should be maintained through the unified application of legislation to related legislation.

• KDI Journal of Economic Policy
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• v.34 no.2
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• pp.55-93
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• 2012

In Korea, energy policies are actualized through various energy-related plans. Recently, however, as high-ranking plans, which are very vision-oriented, continually set higher sector-by-sector goals, subordinate action plans, which require consistency, encounter distortions in their establishment process. Also, each subordinate action plan reveals limitations in terms of securing flexibility of the plan in responding to uncertainties of the future. These problems pose potential risks such as causing huge social costs. In this regard, with an aim to provide empirical evidence for discussions on improving the procedure for developing and executing Korea's energy plans, this study mainly analyzes the Basic Plan on Electricity Demand and Supply-one of the most important subordinate action plans-in order to explain the problems of the Basic Plan in a logical manner, and potential problems that could occur in the process of sustaining consistency between the Basic Plan and its higher-ranking plans. Further, this paper estimates the scale of social costs caused by those problems assuming realistic conditions. According to the result, in the case of where maximum electric power is estimated to be 7% (15%) less than the actual amount in the Basic Plan on Electricity Demand and Supply, the annual generation cost will rise by 286 billion won and (1.2 trillion won) in 2020. Such social costs are found to occur even when establishing and executing the Basic plan according to the target goal set by its higher-ranking plan, the National Energy Master Plan. In addition, when another higher-ranking GHG reduction master plan requires the electricity sector to reduce emissions by additional 5% in the GHG emissions from the right mix in electricity generation with 'zero' cost of carbon emission, the annual generation cost will rise by approximately 915 billion won in 2020. On the other hand, the analysis finds that since economic feasibility of electric powers in Korea varies significantly depending on their type, Korea is expected to face very small potential social costs caused by uncertainties over the future price of carbon dioxide in the process of establishing the Basic Plan.