• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4A
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• pp.343-352
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• 2010

Recently, many researchers have been carried out to estimate more controlled service life and long-term performance of carbonated concrete structures. Durability analysis and design based on probability have been induced to new concrete structures for design. This paper provides a carbonation prediction model based on the Fick's 1st law of diffusion using statistic data of carbonated concrete structures and the probabilistic analysis of the durability performance has been carried out by using a Bayes' theorem. The influence of concerned design parameters such as $CO_2$ diffusion coefficient, atmospheric $CO_2$ concentration, absorption quantity of $CO_2$ and the degree of hydration was investigated. Using a monitoring data, this model which was based on probabilistic approach was predicted a carbonation depth and a remaining service life at a variety of environmental concrete structures. Form the result, the application method using a realistic carbonation prediction model can be to estimate erosion-open-time, controlled durability and to determine a making decision for suitable repair and maintenance of carbonated concrete structures.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.523-528
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• 2004

This study proposed an anisotropic diffusion restoration fer image classification. The anisotropic diffusion restoration uses a probabilistic model based on Markov random field, which represents geographical connectedness existing in many remotely sensed images, and restores them through an iterative diffusion processing. In every iteration, the bonding-strength coefficient associated with the spatial connectedness is adaptively estimated as a function of brightness gradient. This study made experiments on the satellite images remotely sensed on the Korean peninsula. The experimental results show that the proposed approach is also very effective on image classification in remote sensing.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.477-489
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• 2021

COVID-19 has spread seriously around the world in 2020 and it is still significantly affecting our whole daily life. Currently, the whole world is still undergoing the pandemic and South Korea is no exception to it. During the pandemic, South Korea had several events that prevented or accelerated its spread. To establish the prevention policies for infectious diseases, it is very important to evaluate the intervention effect of such events. The susceptible-infected-removed (SIR) model is often used to describe the dynamic behavior of the spread of infectious diseases through ordinary differential equations. However, the SIR model is a deterministic model without considering the uncertainty of observed data. To consider the uncertainty in the SIR model, the Bayesian approach can be employed, and this approach allows us to evaluate the intervention effects by time-varying functions of the infection rate in the SIR model. In this study, we describe the time trend of the spread of COVID-19 in South Korea and investigate the intervention effects for the events using the stochastic SIR model based on the Bayesian approach.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.172-179
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• 2016

For an evaluation of service life in RC(Reinforced Concrete) structures, deterministic method and probabilistic method considering random variables of design parameters are usually adopted. In the work, surface chloride contents which vary with distance from sea shore and height are investigated from the previous research literature surveys, and they are considered for service life estimation. Through the analysis, the probabilistic method shows much lower results, which is due to variations of design parameters and very low intended durability failure. In the deterministic method, the structures within 250m and higher than 60m are evaluated to be free from chloride attack. In the probabilistic method, those higher than 60m in all the region and higher than 40m and 250m from sea shore are evaluated to satisfy the service life.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.569-572
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• 2000

본 논문에서는 DSSS(Direct Sequence Spread Spectrum)를 사용한 무선 감시용 카메라를 위한 모뎀을 제안한다 무선 환경에서 발생할 수 있는 여러 가지 간섭과 다중 경로에 의한 오류 발생 확률 등을 고려해야 하고 또한 여러 대의 카메라를 설치하고 각각의 카메라로부터의 신호를 선택적으로 모니터하기 위해 각각의 신호를 구분할 수 있는 변조 방식의 사용이 필요하다. 이를 위해 컴퓨터 모의 실험을 통한 성능 분석과 실제 FPGA설계 및 제작으로 이를 확인한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.11a
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• pp.40-47
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• 2003

GIS는 공간과 관련된 문제를 해결하는데 있어 좋은 도구가 되며 도시성장 예측과 같은 문제에 사용될 수 있다. 본 연구에서는 수도권 내에 위치한 수원지역을 대상으로 1960년대부터 1990년대까지의 도시성장에 관한 데이터베이스를 구축하고 도시의 물리적인 확산에 초점을 맞추어 모형의 핵심이 되는 공간 연관규칙을 추출하였다. 공간 연관규칙의 추출을 위해 GIS 공간 분석 기능과 데이터마이닝 기법을 이용하였으며, 규칙을 기반으로 모형을 작성하여 도시성장을 분석 및 예측하고 UGM(Urban Growth Model)과 비교하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1629-1637
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• 2003

In this paper, we analyzed the performance of a hybird DS/SFH(Direct­Sequency­Slow Frequency­Hopping) Spread Spectrum system with BFSK modulation over Nakagami­m fading channel with multitone jamming. The performance of the system was improved when a frequency bowing rate increased. In case that process gain of hybrid DS/SFH Spread Spectrum system to be fixed, the hybrid DS/SFH Spread Spectrum takes the low bit error probability than a DS Spread Spectrum system. Also, when the fading index m increases, the fading effect decrease, when the JSR(jamming to signal power ratio) increases ,the performance of a hybrid DS/SFH Spread Spectrum system improved than DS Spread Spectrum system. The result, we have been proved that performance of a hybrid DS/SFH Spread Spectrum was superior to DS Spend Spectrum system over Nakagami­m fading with tome jamming.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.233-236
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• 2012

스마트TV 관련 사업자들은 적어도 당분간은 스마트TV 보급 및 확산을 위해 스마트TV 기능의 탑재율을 높이고 콘텐츠를 마련하는 등 다각도의 노력을 지속할 것으로 보인다. 이용자들은 스마트TV 기능에 대한 기대를 가진 사람뿐만 아니라 단순히 고사양의 TV로 교체하려는 구매자까지 스마트TV를 구매할 확률이 높아지므로 스마트TV의 확산은 당분간은 지속될 것으로 보인다. 스마트TV에 대한 수용도 조사 결과, 스마트TV를 이용해보지 않은 이용자들은 스마트TV 2.0의 가치를 이해하지 못하여 수용도가 낮게 나타났으나 스마트TV 1.0을 경험해본 소비자들은 이미 고도화될때로 고도화된 스마트폰에서의 편리한 경험과 비교하여 스마트TV가 아직은 불편하고 볼꺼리도 부족한 상태라는 것을 바로 인지하게 되므로 스마트TV 2.0에 대한 수용도가 훨씬 높게 나타났다. 따라서 스마트TV 서비스와 산업의 지속적인 성장 발전을 위해서는 이용자들의 기대수준에 맞는 스마트TV로 조속히 진화 발전할 수 있도록 준비해야 할 것이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8B
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• pp.1333-1340
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• 2000

This paper shows that the Kronecker sequence, the rapid acquisition spreading code, can be used in packet wireless data communication systems. The general properties of the Kronecker sequence such as construction and correlation characteristics are described, and it is shown that the Kronecker sequence can use a partial-period correlation for a faster acquisition. Based on above Properties, it can be expected that the Kronecker sequence can be used in packet communication systems because the probability of false alarm for the Kronecker sequence is lower and flatter(that is, less sensitive to Ec/No variations) than that for the PN sequence under the assumption that both sequences have the same acquisition time.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.630-633
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• 2020

무의식적인 손-얼굴의 접촉으로 인한 감염의 문제점을 해결하기 위해, 얼굴 만지기 행동을 인식할 필요가 있다. 본 연구는 최근 각광을 받는 딥러닝 기술을 이용하여 비디오 영상에서 얼굴 만지기 행동 인식에 대한 연구이다. 우선, 비디오 영상에서 얼굴 만지기와 관련된 11 가지 행동에 대한 시, 공간적 특징을 컨볼루션 신경망을 통해 추출한다. 추출된 정보는 각 행동 레이블로 인코딩되어 비디오 영상에서 얼굴 만지기 행동을 분류한다. 또한, 3D, 2D 컨볼루션 신경망의 대표 네트워크인 I3D, MobileNet v3에 대해 비교 실험을 진행한다. 제안하는 시스템을 적용하여 인간의 행동을 분류하는 실험을 진행했을 때, 얼굴을 만지는 행동을 99%의 확률로 구분했다. 이 시스템을 이용하여 일반인이 무의식적인 얼굴 만지기 행동에 대해서 정량적으로 또는 적시적으로 인식을 하여, 안전한 위생 습관을 확립하여 감염의 확산방지에 도움을 줄수 있기를 바란다.