• Journal of information and communication convergence engineering
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• 제1권1호
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• pp.53-57
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• 2003

Chaos theory is a study researching the irregular, unpredictable behavior of deterministic and non-linear dynamical system. The interpretation using Chaos makes us evaluate characteristic existing in status space of system by tine series, so that the extraction of Chaos characteristic understanding and those characteristics enables us to do high precision interpretation. Therefore, This paper propose the new method which is adopted in extracting character features and recognizing characters using the Chaos Theory. Firstly, it gets features of mesh feature, projection feature and cross distance feature from input character images. And their feature is converted into time series data. Then using the modified Henon system suggested in this paper, it gets last features of character image after calculating Box-counting dimension, Natural Measure, information bit and information dimension which are meant fractal dimension. Finally, character recognition is performed by statistically finding out the each information bit showing the minimum difference against the normalized pattern database. An experimental result shows 99% character classification rates for 2,350 Korean characters (Hangul) using proposed method in this paper.

• 디지털융복합연구
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• 제13권1호
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• pp.525-533
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• 2015

본 연구는 여대생들 간의 메이크업에 대한 관심과 인지도 파악하고자 메이크업에 대한 의식 조사를 통하여, 인식유형별로 메이크업에 따른 심리와 선호하는 메이크업 패턴을 조사였다. 메이크업이 개인에게 정서적으로 자신감과 긍정적 사고를 하는데 도움을 주며, 타인에 대한 사회적 예의의 한 범주라고 생각하였다. 메이크업 인식 차이에 따른 대상의 그룹핑은 이미지 관조군 수용군 관망군 대응군으로 분류 할 수 있었다. 인식 차이에 따른 4가지 유형의 메이크업 관심도는 세부적으로 약간의 차이는 있었으나 메이크업 행위가 대인관계 형성 시 높은 필요도를 차지하고 있었으며, 메이크업 패턴은 피부 톤을 중요시하는 자연스러운 스타일을 선호하였다. 이처럼 현재 뷰티 트렌드의 시장의 주 고객층을 형성하고 있는 20대 여대생의 메이크업에 관한 설문조사를 한 결과 트렌드 메이크업 행위에 대한 관심도와 인지도를 파악할 수 있었으며, 본 연구의 결과를 뷰티 트렌드 개발과 마케팅에 적극 활용하면 다양하고 효과적인 미용문화를 창조할 수 있을 것으로 사료된다.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.16-22
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• 2011

This paper presents the potential of in-vehicle data recorder system for monitoring aggressive driving patterns and providing feedback to drivers on their on road behaviour. This system can detect 10 risky types of drivers' driving patterns such as aggressive lane change, sudden brakes and turns with acceleration etc. Vehicle dynamics simulation and vehicle road test have been performed in order to develop driving pattern recognition algorithms. Recorder systems are installed to 50 buses in a single company. Drivers' driving behaviour are monitored for 1 month. The drivers' risky driving data collected by the system are analyzed. Aggressive lane change in 50km/h below is a cause in overwhelming majority of risky driving pattern.

• 정보과학회지
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• 제18권8호
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• pp.78-89
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• 2000

Today's computers are built up from a minimal set of standard pattern recognition operations. Logic gates, such as NAND, are common examples. Biomolecular materials offer an alternative approach, both in terms of variety and context sensitivity. Enzymes, the basic switching elements in biological cells, are notable for their ability to discriminate specific molecules in a complex background and to do so in a manner that is sensitive to particular milieu features and indifferent to others, The enzyme, in effect, is a powerful context sensitivity pattern processor that in a rough way can be analogized to a neuron whose input-output behavior is controlled by enzymatic dynamics.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1735-1741
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• 2011

The safety of station structures among railway infrastructures should be considered as a top priority because hundreds of thousands passengers a day take a subway. The station structures, which have been being operated since the 1970s, are especially vulnerable to the earthquake and long-term vibrations such as ambient train vibrations as well. This is why the structural-health monitoring system of station structures should be required. For these reason, Korean government has made an effort to develop the structural health-monitoring system of them, which can evaluate the health-state of station structures as well as can monitor the vulnerable structural members in real-time. Then, through the monitoring system, the vulnerable structural members could be retrofitted. For the development of health-state evaluation method for station structures with the real-time sensing data measured in the fields, authors carried out the numerical simulations to develop evaluation algorithms based on statistical pattern recognition techniques. In this study, the dynamic behavior of Chungmuro station in Seoul was numerically analyzed and then critical members were chosen. Damages were artificially simulated at the selected critical members of the numerical model. And, the supervised and unsupervised learning based pattern recognition algorithms were applied to quantify and localize the structural defects.

• 한국멀티미디어학회논문지
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• 제10권12호
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• pp.1726-1732
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• 2007

The rapid proliferation of wireless networks and mobile computing applications has changed the landscape of network security. Anomaly detection is a pattern recognition task whose goal is to report the occurrence of abnormal or unknown behavior in a given system being monitored. This paper presents an efficient rough set based anomaly detection method that can effectively identify a group of especially harmful internal attackers - masqueraders in cellular mobile networks. Our scheme uses the trace data of wireless application layer by a user as feature value. Based on this, the used pattern of a mobile's user can be captured by rough sets, and the abnormal behavior of the mobile can be also detected effectively by applying a roughness membership function with the age of the user profile. The performance of the proposed scheme is evaluated by using a simulation. Simulation results demonstrate that the anomalies are well detected by the proposed scheme that considers the age of user profiles.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.315-326
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• 2007

The rapid proliferation of wireless networks and mobile computing applications has changed the landscape of network security. Anomaly detection is a pattern recognition task whose goal is to report the occurrence of abnormal or unknown behavior in a given system being monitored. This paper presents a dynamic anomaly detection scheme that can effectively identify a group of especially harmful internal masqueraders in cellular mobile networks. Our scheme uses the trace data of wireless application layer by a user as feature value. Based on the feature values, the use pattern of a mobile's user can be captured by rough sets, and the abnormal behavior of the mobile can be also detected effectively by applying a roughness membership function with both the age of the user profile and weighted feature values. The performance of our scheme is evaluated by a simulation. Simulation results demonstrate that the anomalies are well detected by the proposed dynamic scheme that considers the age of user profiles.

• Smart Structures and Systems
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• 제21권4호
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• pp.421-433
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• 2018

Carbon fiber reinforced polymer (CFRP) cable has good mechanical properties and corrosion resistance. However, the anchorage of CFRP cable is a big issue due to the anisotropic property of CFRP material. In this article, a high-efficient bonding anchorage with novel configuration is developed for CFRP cables. The acoustic emission (AE) technique is employed to evaluate the performance of anchorage in the fatigue test and post-fatigue ultimate bearing capacity test. The obtained AE signals are analyzed by using a combination of unsupervised K-means clustering and supervised K-nearest neighbor classification (K-NN) for quantifying the performance of the anchorage and damage evolutions. An AE feature vector (including both frequency and energy characteristics of AE signal) for clustering analysis is proposed and the under-sampling approaches are employed to regress the influence of the imbalanced classes distribution in AE dataset for improving clustering quality. The results indicate that four classes exist in AE dataset, which correspond to the shear deformation of potting compound, matrix cracking, fiber-matrix debonding and fiber fracture in CFRP bars. The AE intensity released by the deformation of potting compound is very slight during the whole loading process and no obvious premature damage observed in CFRP bars aroused by anchorage effect at relative low stress level, indicating the anchorage configuration in this study is reliable.

• 정보보호학회논문지
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• 제27권2호
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• pp.361-371
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• 2017

스마트폰 기기 내에 저장되는 사용자 정보가 다양화되어 개인정보에 대한 위협도 함께 증가하고 있다. 패턴 잠금, 지문 인식 등 다양한 사용자 인증 기술이 스마트폰에 적용되어 있으나 사용자 의존적, 거부감 유발 등의 한계점을 보이고 있다. 최근 주목받고 있는 행위 기반 인증은 기기 사용과 동시에 인증이 가능하여 사용자에게 높은 편의성을 제공하나 타 인증 기술에 비해 정확도가 낮아 이를 개선하기 위한 연구가 꾸준히 수행되고 있다. 본 연구에서는 이전 연구에서 고려되지 않았던 앱 사용 정보를 새로운 인증 요소로 활용하는 방법을 제안한다. 또한 실제 앱 사용 상황을 고려한 데이터 수집 및 분석을 통해 제안 기술의 성능을 상세하게 분석한다.

• 한국컴퓨터정보학회논문지
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• 제26권12호
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• pp.133-142
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• 2021

이동 패턴 인식은 사용자 궤적 질의, 사용자 행동 예측, 사용자 위치에 기초한 흥미요소 추천, 사용자 개인 정보 보호 및 지자체 교통 계획과 같은 여러 측면에서 널리 사용된다. 현재 인식 정확도는 응용 요건을 충족할 수 없기 때문에 이동 패턴 인식 연구는 궤적 데이터 연구의 초점이라 할 수 있다. GPS 내비게이션 기술과 지능형 모바일 기기의 대중화로 많은 사용자 모바일 데이터 정보를 얻을 수 있고, 이를 바탕으로 많은 의미 있는 연구가 이루어질 수 있다. 현재의 이동 패턴 연구 방법에서 궤적의 특징 추출은 궤도의 기본 속성(속도, 각도, 가속도 등)으로 제한된다. 본 논문에서 순열 엔트로피는 궤적 분류 연구에 참여하기 위한 궤적의 고유값으로 사용되었으며 시계열의 복잡성을 측정하기 위한 속성으로도 사용되었다. 속도 순열 엔트로피와 각도 순열 엔트로피가 이동 패턴 분류에 참여하기 위한 궤적의 특성으로 사용되었으며, 본 논문에서 사용된 순열 엔트로피를 기반으로 한 속성 분류의 정확도는 81.47%에 달했다.