• The Journal of Korean Association of Computer Education
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• v.16 no.5
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• pp.39-47
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• 2013

In the case of a weak self-control youth, young students easily tend to fall into addiction by using the Internet as a sensation seeking and an alternative to escape the reality. Until now, internet addiction self-diagnosis techniques such as Internet addiction scale have been developed and used to solve this kind of internet addiction issue. However, traditional methods do not assess the correlation of addiction and the effects of the environment systematically because they are simply composed of redundant addiction scale criteria and questionnaire forms of the diagnostic methods. Thus, in this paper, we propose a new internet addiction self-diagnosis technique based on Formal Concept Analysis (FCA) and implement a self-diagnosis system in order to make a systematic internet addiction self-diagnosis system. In addition, we analyze the correlation of the measured data based on different perspectives such as home environment, family relationships, peer relationships, school life, and so on.

• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.199-204
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• 2002

Since motion estimation and motion compensation methods remove the redundant data to employ the temporal redundancy in images, it plays an important role in digital video compression. Because of its high computational complexity, however, it is difficult to apply to high-resolution applications in real time environments. If we have information about the motion of an image block before the motion estimation, the location of a better starting point for the search of an exact motion vector can be determined to expedite the searching process. In this paper, we present an adaptive motion estimation approach bated on temporal correlations of consecutive image frames that defines the search pattern and determines the location of the initial search point adaptively. Through experiments, compared with DS(Diamond Search) algorithm, the proposed algorithm is about 0.1∼0.5(dB) better than DS in terms of PSNR(Peak Signal to Noise Ratio) and improves as high as 50% compared with DS in terms of average number of search point per motion vector estimation.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.595-602
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• 2009

Fuzzy rules, which represent the behavior of their system, are sensitive to fuzzy clustering techniques. If the classification abilities of such clustering techniques are improved, their systems can work for the purpose more accurately because the capabilities of the fuzzy rules and parameters are enhanced by the clustering techniques. Thus, this paper proposes a new hierarchically structured clustering algorithm that can enhance the classification abilities. The proposed clustering technique consists of two clusters based on correlationship and statistical characteristics between data, which can perform classification more accurately. In addition, this paper uses difference data sets to reflect the patterns and regularities of the original data clearly, and constructs multiple fuzzy systems to consider various characteristics of the differences suitably. To verify effectiveness of the proposed techniques, this paper applies the constructed fuzzy systems to the field of time series prediction, and performs prediction for nonlinear time series examples.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.45-45
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• 2022

산업화에 따른 화학물질 사용량의 증가는 담수로의 유해화학물질 유출사고의 위험을 증가시키며, 이러한 사고는 하천수 수질과 수환경 생태계에 심각한 위해와 손상을 야기한다. 이러한 수질사고 발생시 신속 대응을 위해, 하천에 유입된 물질의 거동을 신속하게 예측하는 것이 필요하며 이 경우 1차원 추적모형이 주로 사용된다. 1차원 물질혼합 모형은 하천을 하나의 유선으로 보며, 복잡한 하천흐름의 시스템을 현상학적으로 해석하고, 오염물질의 이송 및 혼합 메카니즘을 모델 매개변수에 반영하여 모형화한다. 이러한 매개변수들은 직접적으로 측정하기 어려우며, 이론에 기반한 매개변수 산정 기법이 구축되지 않은 실정이다. 따라서 대부분의 연구에서는 추적자 실험을 실시하여 유한한 하천구간에서 추적자의 시간-농도곡선(Breakthrough curve, BTC)을 취득하고, 이를 통하여 대상 구간의 매개변수를 역산하는 최적화 기법에 의존하고 있다. 하지만, 모든 하천구간에 대하여 추적자 실험을 수행하여 데이터를 확보하는 것이 어렵기 때문에 최적화 기법의 적용성에 한계가 있다. 본 연구는 흐름정보가 제공되지 않은 미계측 하천구간에서 BTC를 신속하게 예측할 수 있는 회귀모형을 구축하는 것을 목표로 한다. 국내 하천에서 수행한 4회의 추적자 실험으로부터 취득한 28개 구간 케이스의 데이터에 대하여 농도곡선 전처리를 수행하고 14개의 통계적 특징을 추출하였으며, 계측된 흐름특성과의 상관관계를 분석하였다. 분석 결과, 대상 구간에서의 BTC의 변화가 추적자의 유하거리에 매우 높은 상관관계를 보였으며, 이를 이용하여 회귀모형을 제시하였다. 제안된 회귀모형을 적용하여 하류의 지점에서의 BTC를 예측하였으며, 1차원 이송-분산 방정식과 하천저장대모형을 활용한 예측결과와 비교하여 검증하였다. 그 결과, BTC의 변화특성을 활용한 회귀적 예측이 하천 지형 및 흐름의 변동성이 작은 구간에서 1차원 혼합모형들을 이용한 예측보다 더 높은 정확도를 보였으며, 이러한 장점은 장거리 예측에서 더 분명하게 나타났다.

• Spatial Information Research
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• v.11 no.3
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• pp.251-260
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• 2003

Distribution pattern of seawater intrusion was analyzed from the spatial distribution map of chloride using the geostatistics and CIS analyses. The chloride distribution map made by kriging(ordinary kriging and co-kriging) after exploratory spatial data analysis. Kriging provides an advanced methodology which facilitates quantification of spatial features and enables spatial interpolation. TDS, Na$^{＋}$, Br$^{[-10]}$ were selected as second parameters of co-kriging which is higher value of correlation coefficients between chloride and others groundwater properties. Chloride concentration is highest in yeminchon and coastal area. And result in co-kriging was accurate than ordinary kriging.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.852-861
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• 2009

We propose a complexity reduced Lattice Reduction(LR) scheme for MIMO detection under time varying fading environments. It is found that for successive MIMO transmission instances, the integer matrix P after LR decomposition remains the same or only a few elements of the matrix P are slightly changed. Based on this feature, we perform LR reduction by setting the initial values for P matrix for the decomposition to be the one obtained in the previous instance not starting from the identity matrix. Simulation results reveal that the proposed scheme drastically reduces overall complexity of LR reduction compared to the conventional scheme for various system parameters under time varying channels. We also show that the proposed scheme can be applied to Seysen LR as well as LLL(Lenstra, Lenstra, and Lavasaz)-LR.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12C
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• pp.1606-1616
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• 2004

This paper introduces a technique for generating an appropriate template signal via modeling of minimum-phase stable ARMA (Auto-Regressive Moving Average) system for coherent impulse communication systems. It has been well known that the transmitted impulse signal becomes deformed because of dispersive and resonant characteristics. Accordingly, in spite of using ideal template signal at the correlator, these impairments degrade overall performance attributed to low level of coherence. To increase the degree of coherence, our proposed scheme realizes A3U system derived by Gaussian pulse signal, which simulates the overall characteristic of transfer function in between transmit and receive wideband antennas so as to generate an appropriate template signal in a form of output. The performance of proposed scheme will be shown in results from computer simulations to verify its affirmative impact on impulse communication system with regarding several distinctively shaped antennas.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.494-503
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• 2008

Real-time PCR 기법을 이용하여 구강내 치태에서 특정 세균의 존재여부를 알 수 있을 뿐 아니라 정량적 분석이 가능하게 되었다. 이 연구는 real-time PCR 기법을 이용하여 8-18세의 청소년에서 치주질환 원인균의 조성을 알아보고자 전신질환이 없는 어린이 및 청소년 65명을 대상으로 치은연하의 치태를 채취하여 5종의 치주질환 원인균의 출현율과 그 양을 측정하고, 또한 함께 측정한 치태지수 및 치은지수와의 상관관계를 조사하여 다음과 같은 결론을 얻었다. 1. 치태지수의 평균은 1.33이었으며, 치은지수의 평균은 0.97이었다. 치태지수는 나이가 증가할수록 낮아졌다(p<0.05). 2. 치주질환 원인균의 출현율은 P. gingivalis 61.5%, T. forsythia 53.8%, T. denticola 29.2%, A. actinomycetemcomitans 15.4%, F. nucleatum은 100%였다. P. gingivalis, T. denticola는 10세 이후 출현율이 증가하였고 A. actinomycetemcomitans는 8-10세 군에서 출현율이 높았다(p<0.05). 3. 정량적 분석에서 치태지수와 치은지수는 F. nucleatum의 양과 유의한 상관성이 있었으며, 치태지수는 치은지수와 유의한 상관성이 있었다. T. forsythia는 A. actinomycetemcomitans, T. denticola양과 강한 상관성을 보였으며, T. denticola양과 A. actinomycetemcomitans도 강한 상관관계를 가지고 있었다.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.263-267
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• 2009

With the increase of weight and influence of TV drama, Many researchers began to publish papers on TV drama. However, Those papers were mainly about social meaning of TV drama and viewing motives and attitudes of TV audience. However, only a few limited papers were about television image production techniques. The purpose of this thesis is to analyse the relationship between TV genre and image production technique with the data of top 100 of TNS Media Korea from the year 2004 to 2008. This paper found out that history drama uses more closeup, longshot, tracking and less waist shot than other genres, with shorter shot duration and longer scene duration.

• Journal of Korea Water Resources Association
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• v.39 no.8 s.169
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• pp.669-676
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• 2006

Hydrological factors, especially the spatial distribution of interpretation on precipitation is often topic of interest in studying of water resource. The popular methods such as Thiessen method, inverse distance method, and isohyetal method are limited in calculating the spatial continuity and geographical characteristics. This study was intended to overcome those limitations with improved method that will yield higher accuracy. The monthly and yearly precipitation data were produced and compared with the observed daily precipitation to find correlation between them. They were then used as secondary variables in Co-kriging method, and the result was compared with the outcome of existing methods like inverse distance method and kriging method. The comparison of the data showed that the daily precipitation had high correlation with corresponding year's average monthly amounts of precipitation and the observed average monthly amounts of precipitation. Then the result from the application of these data for a Co-kriging method confirmed increased accuracy in the modeling of spatial distribution of precipitation, thus indirectly reducing inconsistency of the spatial distribution of hydrological factors other than precipitation.