• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.1-8
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• 2020

In recent years, due to the exponential increase in internet data, many fields such as deep learning have developed, but side effects generated as commercial advertisements, such as viral marketing, have been discovered. This not only damages the essence of the internet for sharing high-quality information, but also causes problems that increase users' search times to acquire high-quality information. In this study, we define advertisement as "a text that obscures the essence of information transmission" and we propose a model for filtering information according to that definition. The proposed model consists of advertisement filtering and advertisement filtering performance improvement and is designed to continuously improve performance. We collected data for filtering advertisements and learned document classification using KorBERT. Experiments were conducted to verify the performance of this model. For data combining five topics, accuracy and precision were 89.2% and 84.3%, respectively. High performance was confirmed, even if atypical characteristics of advertisements are considered. This approach is expected to reduce wasted time and fatigue in searching for information, because our model effectively delivers high-quality information to users through a process of determining and filtering advertisement paragraphs.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.19-26
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• 2005

After various video coding standards such as H.263, MPEG-4, and H.264 have been introduced, there has bun strong need to support the multiple standards with limited resources efficiently. In terms of deblocking Inter which plays an important role in improving visual quality, K264 deblocking filter implementation has different aspects as compared with traditional $8\times8$ block-based post-filter implementation. Analyzing the differences, this paper proposes a H.264 deblocking filter implementation method that supports $8\times8$ block-based post-filtering for the traditional video coding systems. In the proposed implementation method the block boundaries to he filtered are adaptively chosen for $8\times8$ and $4\times4$ block boundary filtering. Since the filtered result is selectively used for motion compensation or not, both loop-filtering and post-filtering can be achieved. A quantization parameter conversion unit that converts H.263 quantization parameters to H.264 quantization parameters is utilized by examining the $8\times8$ block boundary errors based on human visual system. Since the original nature of the H.264 deblocking filter is well expanded to the $8\times8$ block-based post-filter with minor modifications, the proposed implementation method is suitable to implement the deblocking function of the multiple video standards such as H.263, MPEG-4, and K264, efficiently.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.7
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• pp.345-350
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• 2016

This research suggests the keyword filtering about disaster and the method of detecting area in real-time event detecting system by analyzing contents of twitter. The diffusion of smart-mobile has lead to a fast spread of SNS and nowadays, various researches based on studying SNS are being processed. Among SNS, the twitter has a characteristic of fast diffusion since it is written in 140 words of short paragraph. Therefore, the tweets that are written by twitter users are able to perform a role of sensor. By using these features the research has been constructed which detects the events that have been occurred. However, people became reluctant to open their information of location because it is reported that private information leakage are increasing. Also, problems associated with accuracy are occurred in process of analyzing the tweet contents that do not follow the spelling rule. Therefore, additional designing keyword filtering and the method of area detection on detecting real-time event process were required in order to develop the accuracy. This research suggests the method of keyword filtering about disaster and two methods of detecting area. One is the method of removing area noise which removes the noise that occurred in the local name words. And the other one is the method of determinating the area which confirms local name words by using landmarks. By applying the method of keyword filtering about disaster and two methods of detecting area, the accuracy has improved. It has improved 49% to 78% by using the method of removing area noise and the other accuracy has improved 49% to 89% by using the method of determinating the area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12B
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• pp.2141-2153
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• 2000

본 논문에서는 DMT 기반의 xDSL 시스템의 수신단에서 발생하는 샘플링 위상 옵셋과 샘플링 주파수 옵셋에 의한 타이밍 오류를 분석한 후, 디지털 수신기에서 이를 보상하기 위한 비동기식 샘플링(full digital PLL) 방식을 제안한다. 기존의 논문에서는 DMT 방식의 xDSL 시스템에서 샘플링 위상 옵셋을 delay-rotor 특성을 이용한 주파수영역 위상 회전기로 보상하는 비동기식 샘플링 방식을 제안한 바 있다. 그러나 수신단에서 샘플링 시 존재하는 타이밍 오류로 인해 저역통과 필터링된 수신신호는 더 이상 delay-rotor 특성이 성립하지 않아 성능이 크게 저하된다. 본 논문에서는 샘플링 위상 옵셋을 완벽하게 보상할 수 있는 데이터 구간의 환형 컨벌루션화(circular convolution) 방식을 제안한다. 또한 샘플링 위상 옵셋과 샘플링 주파수 옵셋이 동시에 존재하는 경우 이를 보상할 수 있는 개선된 시간/주파수 혼성영역 보상방식을 제안한다. 또한 추가의 오버헤드를 사용하지 않고 샘플링 위상 옵셋과 샘플링 주파수 옵셋을 보상할 수 있는 시간영역 보상방식을 제안한다. 마지막으로 DMT 방식의 ADSL 시스템에 본 논문에서 제안된 비동기식 샘플링 방식들을 적용하여 모의실험을 통해 성능을 분석하고 기존의 방식과 비교하여 성능의 우수성을 확인한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.3
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• pp.25-31
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• 2003

In this paper, we proposed a novel compact microstrip lowpass filter with an ultra-wide stopband and a sharp cutoff frequency response. To improve the cutoff response of the conventional filter, the coupling effect between two open stubs is used. The slot on the ground with conventional shunt open stubs plays an important role of increasing the stopband at a high frequency. The combination of these structures gives the filter the characteristics of an ultra-wide stopband with a prominent cutoff sharpness. The fabricated microstrip lowpass filter with the size of 19.2 mm $\times$ 14.9 mm has -3 dB cutoff frequency at 1.1 GHz and -20 dB stopband from 1.5 GHz to over 30 GHz. The insertion loss is less than -0.15 dB in the passband.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.91-94
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• 2011

The LBSNS(Location-Based Social Networking Service) service has been well-received by researchers and end-users, such as Twitter. Location-Based service of Twitter is now structured that users could not subscribe the information of their interesting local area. Those who being following from someone tweet message included information of local area to them just for their own interesting. However, follower may receive that kind of tweet. In order to handle the problem, we propose filtering technique using spatial join. The first work for filtering technique is to add a location information to tweets and users. In this paper, location information is represented by MBR(Minimum Bounding Rectangle). Location information is divided into dynamic property and static property. Suppose that users are continuously moving, that means one of the dynamic property's example. At this time, a massive continous query could cause the problem in server. In this paper, we create Virtual Grid on Google Map for reducing frequency of query, and conclude that it is useful for server.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.93-100
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• 2022

In the era of information overload on the Internet, the recommendation system, which is an indispensable function, is a service that recommends products that a user may prefer, and has been successfully provided in various commercial sites. Recently, studies to reflect the rating time of items to improve the performance of collaborative filtering, a representative recommendation technique, are active. The core idea of these studies is to generate the recommendation list by giving an exponentially lower weight to the items rated in the past. However, this has a disadvantage in that a time function is uniformly applied to all items without considering changes in users' preferences according to the characteristics of the items. In this study, we propose a time-aware collaborative filtering technique from a completely different point of view by developing a new similarity measure that integrates the change in similarity values between items over time into a weighted sum. As a result of the experiment, the prediction performance and recommendation performance of the proposed method were significantly superior to the existing representative time aware methods and traditional methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.110-116
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• 2017

This paper presents an effective demosaicking algorithm for color filter array (CFA) images acquired from single-sensor devices based on directional interpolation and nonlocal properties of the image. We interpolate the G channel considering diagonal directions as well as horizontal and vertical directions, using a small number of pixels to reflect local properties of the image. Then, we overcome image degradations, such as zipper effects near edges and false colors, by applying nonlocal means (NLM) filtering to the interpolated pixels. R and B channels are reproduced by using directional interpolation with information of the reconstructed G channel and NLM filtering. Experimental results for various McMaster images with high saturation and color changes show that the proposed algorithm accomplishes high PSNR compared with conventional methods. Moreover, the proposed method demonstrates better subjective quality compared with existing methods in terms of reduction of quality degradation, like false colors, and preservation of the image structures, such as edges and textures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.443-446
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• 2005

As modern society needs to process of acquisition, storage and transmission of much information, the importance of signal processing is increasing and various digital filters are used in the two-dimensional signal such as image. And kinds of these digital filters are IIR(infinite impulse response) filter and FIR(finite impulse response) filter. And FIR filter which has the phase linearity, the easiness of creation and stability is applied to many fields. In design of this FIR filter, flatness property is a important factor in pass-band and stop-band. In this paper, we designed a 2-D Circular FIR filter using the Bernstein polynomial, it is presented flatness property in pass-band and stop-band. And we simulated the designed filter with noisy test image and compared the results with existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1687-1693
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• 2013

This paper addresses an adaptive postprocessing technique to remove blocking effects of the highly compressed images. The proposed technique removes blocking effects selectively by applying filters with different strength according to block analysis based on the directional activity. One-dimensional filters which are used to remove grid noises accomplish the adaptive filtering to the signal itself as well as to the directionality of the block. Moreover, we propose a detection method of the staircase noises and corner outliers and a two-dimensional directional filter to remove them. Experimental results for various images and bitrates show that the proposed method outperforms the conventional methods in PSNR for the objective performance and GBIM for the subjective quality evaluation.