• 한국농촌건축학회논문집
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• 제22권4호
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• pp.71-78
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• 2020

Today, the whole world is going through a big chaos due to the COVID-19, but paradoxically, the emergence of COVID-19 has been leading to the need for sustainable development, such as Green New Deal that can improve global warming and carbon emissions, and the need for sustainable architecture is growing bigger and bigger in the architectural field as well. The level of CLT buildings in Korea is at a very rudimentary stage, while CLT buildings remedying existing wooden buildings are getting the spotlight among European countries for sustainable architecture. This study was conducted to categorize structure layer compositions of overseas CLT buildings and analyze architectural techniques and materials applied by collecting and analyzing information about CLT structure layer compositions of overseas CLT building-related institutions, companies and cases. When classifying structure layer compositions of foreign CLT buildings depending on the roles of layers. it was revealed that exterior wall structure layers were combined and organized within a sequence of external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, sloped roof structure layers were external finishing, ventilation, waterproof, board, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing, flat roof structure layers were external finishing, ventilation, waterproof, planking wood, external insulation, waterproof, external insulation, airtightness, structure, airtightness, interior insulation, interior finishing.

• Structural Engineering and Mechanics
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• 제45권5호
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• pp.595-611
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• 2013

This paper aims to compare three collocation point methods associated with the odd order stochastic response surface method (SRSM) in a systematical and quantitative way. The SRSM with the Hermite polynomial chaos is briefly introduced first. Then, three collocation point methods, namely the point method, the root method and the without origin method underlying the odd order SRSMs are highlighted. Three examples are presented to demonstrate the accuracy and efficiency of the three methods. The results indicate that the condition that the Hermite polynomial information matrix evaluated at the collocation points has a full rank should be satisfied to yield reliability results with a sufficient accuracy. The point method and the without origin method are much more efficient than the root method, especially for the reliability problems involving a large number of random variables or requiring complex finite element analysis. The without origin method can also produce sufficiently accurate reliability results in comparison with the point and root methods. Therefore, the origin often used as a collocation point is not absolutely necessary. The odd order SRSMs with the point method and the without origin method are recommended for the reliability analysis due to their computational accuracy and efficiency. The order of SRSM has a significant influence on the results associated with the three collocation point methods. For normal random variables, the SRSM with an order equaling or exceeding the order of a performance function can produce reliability results with a sufficient accuracy. The order of SRSM should significantly exceed the order of the performance function involving strongly non-normal random variables.

• 대한의용생체공학회:의공학회지
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• 제15권4호
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• pp.383-388
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• 1994

일정한 단속 주파수(triggering frequency)를 지닌 청각자극의 반송 주파수(carrier ferquency, pure tone)를 1kHz에서 3kHz까지 0.5kHz단위로 증가시키면서, 이에 반응하는 뇌전위를 디지탈 EEG측정장치를 이용하여 총 7초 동안 1kHz의 sampling frequency로 컴퓨터로 전송하였다. 먼저 신호의 pseudo-phase space분석을 통해 뇌전위의 진폭특성을 파악하였다. 이러한 해석은 생리학적으로 밝져진 소리의 반송주파수와 소리의 크기 인지사이의 상관관계와 잘 일치함이 확인되었다. 또한 이 신호외 Lyapunov exponent 분석을 통해 신호의 발산 특성을 물리적으로 파악하고, 이러한 특성을 이미 여러가지 접근법에 의해 밝혀져 있는 생리학적 실험결과와 관련지어 해석함으로써 반송 주파수에 반응하는 뇌의 mechanism을 뇌전위 측정에 의해서 검출이 가능함을 확인할 수 있었다.

• 전자공학회논문지CI
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• 제37권5호
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• pp.45-53
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• 2000

0.8㎛ 단일 폴리 CMOS 집적회로로 구현된 혼돈 뉴런의 동적 응답 특성을 분석하였다. 구현된 CMOS 혼돈 뉴런의 시그모이드 출력함수와 혼돈 발생회로 블록에 대한 일련의 수식 모델을 구하여 혼돈 뉴런의 동적 응답특성, 즉 뉴런 내부상태의 분기도 및 초기값 의존성을 보여주는 리아프노프 지수와 평균 발화율, 시간 및 주파수 응답 등 다양한 특성들을 수치해석적으로 분석하였다. 뿐만 아니라 4개의 시냅스를 지닌 2개의 혼돈 뉴런으로 이루어진 카오스 신경 회로망을 구성하여 시냅스 가중치에 따른 분기도 변화를 구하고 뉴럴 네트워크에서의 응용 가능성을 확인하였다. 한편 CMOS 집적회로로 구현된 혼돈 뉴런을 ±2.5V 전원, 10㎑의 클럭으로 구동시켜 단일 혼돈 뉴런 및 2개의 뉴런으로 이루어진 카오스 신경망에 대한 여러 동적 응답 특성을 측정하여 수치해석 결과와 비교, 분석하였다.

• 한국의학물리학회지:의학물리
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• 제8권1호
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• pp.75-82
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• 1997

인체의 생리기관의 운동은 매우 복잡하고 불규칙적인 운동을 보이고 있다. 특히 말초 혈관의 운동은 매우 민감하고 복잡한 운동특성을 보이고 있다. 그중에서도 당 (glucose)에 의한 운동은 매우 민감한 변화의 운동을 반응한다. 이런 운동을 분석하기에는 기존의 선형적인 분석방법으로 복잡한 혈류운동을 분석하고 예측하기에는 많은 문제점을 가지고 있다. 그래서 비선형적 운동계의 분석방법인 카오스이론의 시계열분석방법으로 분석하는 것이 적합하다. 이런 맥락으로 본 연구는 당의 주입에 의한 토끼의 말초혈류량의 스칼라적 데이터를 획득하여 시계열분석방법으로 다차원의 벡터로 재정의하여 말초혈관의 혈류운동이 카오스적 운동임을 재확인하고 비선형적분석방법의 적합성을 확인하고자 하였다. 그 결과 당 주입에 따른 혈당치의 변화에 따라 기존의 주파수분석 및 평균치분석에서 차이가 나타나지 않았지만 비선형적분석방법으로 분석한 결과 그 차이를 확인할수 있었고, 말초 혈류의운동이 카오스적현상을 보임을 확인하였다.

• 복식문화연구
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• 제18권6호
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• pp.1274-1290
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• 2010

This study analyzed the design elements and fashion images of women's knitwear in collections of Paris, Milan, London and New York between 2003 and 2008, and examined knitwear trends in an effort to verify whether knitwear trends are repeated in certain cycles, whether they show complicated patterns in cycles and yet occur in quasi cycles, or whether they occur non-periodically in complicated forms of chaotic cycles. Trend cycle analysis results are deemed to identify the time series attribute of knit fashions. It also sought to categorize the attribute of various factors influencing knitwear trends with a view to determining relevancy between design elements, and to present the direction of predicting knitwear fashion trends and the progression of short-term knitwear trends. This study reached the following conclusion. According to design elements or fashion images, knitwear fashion trends occur in cycles, quasi cycles, non-periodical cycles. These cyclic characteristics can be used as scientific data for planning knitwear products. The study confirmed close relevancy between fashion images and fashion elements. It identified close relevancy between designs with similar fashion elements and images through coordinates by year and season, and it is possible to make short-term prediction of trend direction through the flow of coordinates. Time series data were insufficient, thereby making it difficult to perfectly verify chaos indices and giving limitations to this study. A study with more time series data will produce a more effective method of predicting and using knitwear fashion trends.

• Journal of Information Technology Applications and Management
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• 제25권1호
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• pp.19-32
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• 2018

Fake news is defined as the news articles that are intentionally and verifiably false, and could mislead readers. Spread of fake news may provoke anxiety, chaos, fear, or irrational decisions of the public. Thus, detecting fake news and preventing its spread has become very important issue in our society. However, due to the huge amount of fake news produced every day, it is almost impossible to identify it by a human. Under this context, researchers have tried to develop automated fake news detection method using Artificial Intelligence techniques over the past years. But, unfortunately, there have been no prior studies proposed an automated fake news detection method for Korean news. In this study, we aim to detect Korean fake news using text mining and machine learning techniques. Our proposed method consists of two steps. In the first step, the news contents to be analyzed is convert to quantified values using various text mining techniques (Topic Modeling, TF-IDF, and so on). After that, in step 2, classifiers are trained using the values produced in step 1. As the classifiers, machine learning techniques such as multiple discriminant analysis, case based reasoning, artificial neural networks, and support vector machine can be applied. To validate the effectiveness of the proposed method, we collected 200 Korean news from Seoul National University's FactCheck (http://factcheck.snu.ac.kr). which provides with detailed analysis reports from about 20 media outlets and links to source documents for each case. Using this dataset, we will identify which text features are important as well as which classifiers are effective in detecting Korean fake news.

• 감성과학
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• 제1권1호
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• pp.69-78
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• 1998

Sleep deprivation may affect the brain functions such as cognition and consequently, dynamics of the BEG. We examined the effects of sleep deprivation on chaoticity of the EEG. Five volunteers were sleep-deprived over a period of 24 hours They were checked by EEG during two days. thc first day of baseline period and the second day of total sleep deprivation period. EEGs were recorded from 16 channels for nonlinear analysis. We employed a method of minimum embedding dimension to calculate the first positive Lyapunov exponent. Fer limited noisy data, this algorithm was strikingly faster and more accurate than previous ones. Our results show that the sleep deprived volunteers had lower values of the first positive Lyapunov exponent at ten channels (Fp1, F4. F8. T4, T5. C3, C4. P3. P4. O1) compared with the values of baseline periods. These results suggested that sleep deprivation leads to decrease of chaotic activity in brain and impairment of the information processing in the brain. We suggested that nonlinear analysis of the EEG before and after sleep deprivation may offer fruitful perspectives for understanding the role if sleep and the effects of sleep deprivation on the brain function.

• 전자공학회논문지SC
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• 제37권3호
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• pp.55-62
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• 2000

0.8㎛ single poly CMOS 집적회로로 구현된 이산시간 전압모드 혼돈 발생회로의 동작특성을 분석하였다. 회로내 비선형 함수 블록에 대한 선형근사식을 유도하여, 실험적으로 제작한 혼돈 발생회로의 해석이 가능하도록 하였다. 혼돈상태 판별의 주요 지표인, 입력변수에 따른 분기도를 구하였고 초기값 의존성을 보여 주는 리아프노프 지수도 계산하였다. 뿐만 아니라 상태조건, 즉 평형상태, 주기상태, 혼돈상태에 따라 나타나는 시간파형 및 상태천이관계 그리고 주파수특성을 보여주는 전력스펙트럼도 구하여 상호 연관성을 보였다. 한편 집적화 된 혼돈 발생회로를 ±2.5V 전원, 10㎑의 클럭으로 구동시켜 입력전압에 따른 분기도를 측정하였고, 상태조건에 따라 다르게 나타나는 시간파형의 측정과 이의 전력스펙트럼 분석도 실시하여 해석결과와 비교하였다.

• 산업진흥연구
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• 제1권2호
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• pp.121-128
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• 2016

Cultural heritage means a great lot to a nation's social system and its people's behavior consciousness and plays an important role in its self-development and improvement. It is essential for a nation's self-education and renewal. Improper cultural heritage will be disastrous because it may fall a nation into a loss of terrible chaos. Only the proper cultural heritage can make it always self-awaking, self-correcting and remaining vital in life. This paper, from the perspective of Choi Bu's Pyohaerok, makes a thorough analysis of the unbalance heritage of Chinese ancient culture for thousands of years. For example, many fine traditions gradually vanished in our actual life or only take half their life in heritage nowadays, such as our ancient broad and profound Confucian etiquette, ancient exquisite brocade art and architecture, ancient advanced ship-building technology and many other advanced numerous technological inventions; however, too much unwanted cultural rubbish keeps constant prevailing and takes repeated successions in the life, such as the heavy-form-and-light-content management mode, borrowing power to do evil, neglecting technological inventions long time and generally believing in ghost theory,etc.. This paper mainly focuses on the partial successions of the bad cultural heritage and its bad influence on the country, and concludes that it is just that that makes the country more and more backward. Therefore, the paper makes some pondering over these issues and proposes some related ideas of country-building to attract others participation to deal with them.