• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.353-354
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• 2014

An active vibration control technique of a time-varying cantilever beam is proposed in this study. A simple in-house coil sensor instead of expensive commercial sensors was used to measure the vibrational displacement of the beam. Active band pass filters and artificial neutral net works detect the frequencies, amplitudes, and phases of the main vibration mode. The time constants of the low pass filter representing the positive position feedback controller are updated in real-time, which generates the control voltage input to actuate the piezoelectric actuator and suppress the vibration. An experiment was successfully performed to verify the algorithm for a cantilever beam, which fundamental natural frequency arbitrarily varies between 9 Hz ~ 18 Hz. The present active vibration suppression technique can be applied to variety of structures which undergoes large variation of dynamic characteristics while operating.

• 대한교통학회지
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• 제19권6호
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• pp.7-17
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• 2001

본 연구는 교통관리 시스템의 유고검지 체계를 검토하여 기존 체계의 문제점과 한계점을 극복할 수 있는 새로운 검지체계를 구축하고 새로 구축된 검지 체계에 맞는 알고리즘을 개발하는데 연구 목적이 있다. 새로운 검지체계는 검지기 1개소의 설치로 다차로를 검지할 수 있으며 특히 1개 차로 내에서도 검지영역을 여러 개 검지할 수 있는 다 검지체계의 장점을 최대한 살린 시스템이므로 기존 체계의 한계성인 단일 검지영역 문제를 해소할 수 있으며 경제적으로 교통관리 시스템을 구축할 수 있는 장점을 가지고 있다. 이 시스템으로 고속도로와 국도상에서 유고 검지율을 기존의 APID와 DES를 비교하여 현장 시험 평가한 결과 이 시스템이 제일 높은 유고 검지율을 나타내어 기존 시스템보다 우수한 것으로 판명되었다.

• International Journal of Computer Science & Network Security
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• 제21권3호
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• pp.206-211
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• 2021

Internet users are increasingly invited to express their opinions on various subjects in social networks, e-commerce sites, news sites, forums, etc. Much of this information, which describes feelings, becomes the subject of study in several areas of research such as: "Sensing opinions and analyzing feelings". It is the process of identifying the polarity of the feelings held in the opinions found in the interactions of Internet users on the web and classifying them as positive, negative, or neutral. In this article, we suggest the implementation of a sentiment analysis tool that has the role of detecting the polarity of opinions from people about COVID-19 extracted from social media (tweeter) in the Arabic language and to know the impact of the pre-processing phase on the opinions classification. The results show gaps in this area of research, first of all, the lack of resources when collecting data. Second, Arabic language is more complexes in pre-processing step, especially the dialects in the pre-treatment phase. But ultimately the results obtained are promising.

• International Journal of Computer Science & Network Security
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• 제21권5호
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• pp.84-89
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• 2021

Medical tests are very important part of the health monitoring process. It is performed for various reasons like diagnosing diseases, determining medications effectiveness, etc. Due to that, patients should be able to read and understand the available online tests and results in order to take proper decisions regarding their health condition. In fact, people are varying in their educational level and health backgrounds that make providing such information in an easily readable format by the majority of people considered as a challenge in the health domain since ever. This paper describes the MTReadable corpus which constructed for evaluating the readability of online medical tests. It covered 32 basic periodic check-up tests with over 36k words. These tests information are annotated and labelled based on three readability levels which are easy, neutral and difficult by three non-specialists native Arabic speakers. This paper contributes to enriching the Arabic health research community with an investigation of the level of readability of online medical tests and to be a baseline for further complex health online reports and information.

• Journal of Contemporary Eastern Asia
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• 제19권2호
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• pp.234-263
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• 2020

This study aims to assess the quality of the EU's public diplomacy efforts through social media. Specifically, this research explores the headquarters of European public diplomacy (European External Action Service, EEAS) and its subordinate agent (EU Delegation to South Korea, EUDK). The main research question is "how coherently and effectively does the EU execute public diplomacy strategies in the third countries?'' This study employs both quantitative and qualitative approaches―the former for the results presentation and the latter for the results interpretation. The results are summarized in two points. First, both the EEAS and the EUDK maintained an objective position by posting only neutral perspectives on their social media. Second, the narratives of the main actors were the same, but the main themes were different according to their contexts. The analysis discusses the effectiveness of the EU's strategic narratives by focusing on measuring message reception. Its limited findings were that social media postings could not induce the audiences' active discussion of the EU's diplomatic performances. The conclusion suggests that the EU should identify the expectations from its global counterparts and use these to forge the Union's strategic narratives.

• International Journal of Computer Science & Network Security
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• 제21권11호
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• pp.1-10
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• 2021

Cyberbullying has become a severe issue and brought a powerful impact on the cyber world. Due to the low cost and fast spreading of news, social media has become a tool that helps spread insult, offensive, and hate messages or opinions in a community. Detecting cyberbullying from social media is an intriguing research topic because it is vital for law enforcement agencies to witness how social media broadcast hate messages. Twitter is one of the famous social media and a platform for users to tell stories, give views, express feelings, and even spread news, whether true or false. Hence, it becomes an excellent resource for sentiment analysis. This paper aims to detect cyberbully threats based on Naïve Bayes, support vector machine (SVM), and k-nearest neighbour (k-NN) classifier model. Sentiment analysis will be applied based on people's opinions on social media and distribute polarity to them as positive, neutral, or negative. The accuracy for each classifier will be evaluated.

• International Journal of Computer Science & Network Security
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• 제24권5호
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• pp.217-223
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• 2024

The current study aimed to evaluate the effectiveness of using Support Vector Machine (SVM) for political affiliation classification. The system was designed to analyze the political tweets collected from Twitter and classify them as positive, negative, and neutral. The performance analysis of the SVM classifier was based on the calculation of metrics such as accuracy, precision, recall, and f1-score. The results showed that the classifier had high accuracy and f1-score, indicating its effectiveness in classifying the political tweets. The implementation of SVM in this study is based on the principle of Structural Risk Minimization (SRM), which endeavors to identify the maximum margin hyperplane between two classes of data. The results indicate that SVM can be a reliable classification approach for the analysis of political affiliations, possessing the capability to accurately categorize both linear and non-linear information using linear, polynomial or radial basis kernels. This paper provides a comprehensive overview of using SVM for political affiliation analysis and highlights the importance of using accurate classification methods in the field of political analysis.

• 지능정보연구
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• 제28권2호
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• pp.237-262
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• 2022

본 연구는 개인투자자들의 투자의사결정에 도움을 주고자, 증권신고서의 TF-IDF 텍스트 분석과 기계학습을 이용해 공모주의 상장 5거래일 이후 주식 가격 등락을 예측하는 모델을 제시한다. 연구 표본은 2009년 6월부터 2020년 12월 사이에 신규 상장된 691개의 국내 IPO 종목이다. 기업, 공모, 시장과 관련된 다양한 재무적 및 비재무적 IPO 관련 변수와 증권신고서의 어조를 분석하여 예측했고, 증권신고서의 어조 분석을 위해서 TF-IDF (Term Frequency - Inverse Document Frequency)에 기반한 텍스트 분석을 이용해 신고서의 투자위험요소란의 텍스트를 긍정적 어조, 중립적 어조, 부정적 어조로 분류하였다. 가격 등락 예측에는 로지스틱 회귀분석(Logistic Regression), 랜덤 포레스트(Random Forest), 서포트벡터머신(Support Vector Machine), 인공신경망(Artificial Neural Network) 기법을 사용하였고, 예측 결과 IPO 관련 변수와 증권신고서 어조 변수를 함께 사용한 모델이 IPO 관련 변수만을 사용한 모델보다 높은 예측 정확도를 보였다. 랜덤 포레스트 모형은 1.45%p 높아진 예측 정확도를 보였으며, 인공신공망 모형과 서포트벡터머신 모형은 각각 4.34%p, 5.07%p 향상을 보였다. 추가적으로 모형간 차이를 맥니마 검정을 통해 통계적으로 검증한 결과, 어조 변수의 유무에 따른 예측 모형의 성과 차이가 유의확률 1% 수준에서 유의했다. 이를 통해, 증권신고서에 표현된 어조가 공모주의 가격 등락 예측에 영향을 미치는 요인이라는 것을 확인할 수 있었다.

• 한국지능시스템학회:학술대회논문집
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• 한국지능시스템학회 2007년도 추계학술대회 학술발표 논문집
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• pp.411-414
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• 2007

본 논문은 뉴트럴 타입 시간 지연을 갖는 네트워크 시스템의 안정도 분석 및 퍼지 제어기 설계에 대해서 논의한다. 먼저 대상이 되는 네트워크 시스템은 TS (Takagi-Sugeno: T-S) 퍼지 모델로 표현 되어진다. 리아프노프-크라조브스키의 안정도 이론을 이용하여 뉴트럴 형태의 시간 지연을 갖는 퍼지 시스템의 안정도를 판별한다. 퍼지 시스템의 안정도 조건을 시간 지연에 종속적인 충분조건으로 제시하고 선형 행렬 부등식의 형태로 표현한다. 선형 행렬 부동식의 해를 구하고 이를 바탕으로 퍼지 제어기의 이득값을 설계한다. 제안된 방법의 효율성과 가능성을 보여주기 위해 한 예제를 포함한다.

• 가정과삶의질연구
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• 제27권3호
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• pp.45-60
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• 2009

This study reviewed the influence of consumer innovativeness and consumer knowledge on external information search behavior for the purchase of high-tech products. The strategies for offering information effectively for high-tech products may be proposed as follows based on the results of this study. First, the advertisements of high-tech products which are generally encountered need to offer sufficient information about the products in addition to fulfilling the function of persuading consumers. Second, it is necessary to implement an information network so that neutral offerings of information about high-tech products may be made promptly by reliable institutions. Third, information about high-tech products should be offered with easier explanations so that there should be no information-underprivileged class in utilizing the function of high-tech products.