• International Journal of Control, Automation, and Systems
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• v.3 no.4
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• pp.571-579
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• 2005

In this paper, we proposed an algorithm for arrhythmia classification, which is associated with the reduction of feature dimensions by linear discriminant analysis (LDA) and a support vector machine (SVM) based classifier. Seventeen original input features were extracted from preprocessed signals by wavelet transform, and attempts were then made to reduce these to 4 features, the linear combination of original features, by LDA. The performance of the SVM classifier with reduced features by LDA showed higher than with that by principal component analysis (PCA) and even with original features. For a cross-validation procedure, this SVM classifier was compared with Multilayer Perceptrons (MLP) and Fuzzy Inference System (FIS) classifiers. When all classifiers used the same reduced features, the overall performance of the SVM classifier was comprehensively superior to all others. Especially, the accuracy of discrimination of normal sinus rhythm (NSR), arterial premature contraction (APC), supraventricular tachycardia (SVT), premature ventricular contraction (PVC), ventricular tachycardia (VT) and ventricular fibrillation (VF) were $99.307\%,\;99.274\%,\;99.854\%,\;98.344\%,\;99.441\%\;and\;99.883\%$, respectively. And, even with smaller learning data, the SVM classifier offered better performance than the MLP classifier.

• Journal of Biomedical Engineering Research
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• v.31 no.5
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• pp.365-374
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• 2010

This paper is about the personal identification algorithm using an ECG that has been studied by a few researchers recently. Previously published algorithm can be classified as two methods. One is the method that analyzes ECG features and the other is the morphological analysis of ECG. The main characteristic of proposed algorithm uses together two methods. The algorithm consists of training and testing procedures. In training procedure, the features of all recognition objects' ECG were extracted and the PCA was performed for morphological analysis of ECG. In testing procedure, 6 candidate ECG's were chosen by morphological analysis and then the analysis of features among candidate ECG's was performed for final recognition. We choose 18 ECG files from MIT-BIH Normal Sinus Rhythm Database for estimating algorithm performance. The algorithm extracts 100 heartbeats from each ECG file, and use 40 heartbeats for training and 60 heartbeats for testing. The proposed algorithm shows clearly superior performance in all ECG data, amounting to 90.96% heartbeat recognition rate and 100% ECG recognition rate.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.4076-4092
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• 2019

Nowadays, most users access internet through mobile applications. The common way to authenticate users through websites forms is using passwords; while they are efficient procedures, they are subject to guessed or forgotten and many other problems. Additional multi modal authentication procedures are needed to improve the security. Behavioral authentication is a way to authenticate people based on their typing behavior. It is used as a second factor authentication technique beside the passwords that will strength the authentication effectively. Keystroke dynamic rhythm is one of these behavioral authentication methods. Keystroke dynamics relies on a combination of features that are extracted and processed from typing behavior of users on the touched screen and smart mobile users. This Research presents a novel analysis in the keystroke dynamic authentication field using two features categories: timing and no timing combined features. The proposed model achieved lower error rate of false acceptance rate with 0.1%, false rejection rate with 0.8%, and equal error rate with 0.45%. A comparison in the performance measures is also given for multiple datasets collected in purpose to this research.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.5 s.305
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• pp.27-34
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• 2005

Ventricular fibrillation(VF) is generally caused by chaotic behavior of electrical propagation in heart and may result in sudden cardiac death. In this study, we proposed a ventricular fibrillation detection algorithm based on support vector machine classifier, which could offer benefits to reduce the teaming costs as well as good classification performance. Before the extraction of input features, raw ECG signal was applied to preprocessing procedures, as like wavelet transform based bandpass filtering, R peak detection and segment assignment for feature extraction. We selected input features which of some are related to the rhythm information and of others are related to wavelet coefficients that could describe the morphology of ventricular fibrillation well. Parameters for SVM classifier, C and ${\alpha}$, were chosen as 10 and 1 respectively by trial and error experiments. Each average performance for normal sinus rhythm ventricular tachycardia and VF, was 98.39%, 96.92% and 99.88%. And, when the VF detection performance of SVM classifier was compared to that of multi-layer perceptron and fuzzy inference methods, it showed similar or higher values. Consequently, we could find that the proposed input features and SVM classifier would one of the most useful algorithm for VF detection.

• Journal of Chest Surgery
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• v.16 no.1
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• pp.97-101
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• 1983

The steadily increasing number of operations performed on the heart has given rise to occasional complications involving the nervous system, and this has been interested to cardiac surgeons and neurologists. This survey has been carried out on all Gases submitted to open heart surgery at Seoul National University Hospital during 1982 to determine which operative features were associated with the occurrence of neurological damage. 514 subjects were studied and neurological damage was noted in twenty-five patients [4.9%]. Eight of these 25 patients died in the postoperative period, but neurological damage contributed to the fatal outcome in six cases. Remaining seventeen patients were discharged without problems except one Cortical blindness and one hemiplegic patients who were survived without other problems . A number of features were found to be related to the development of neurological damage, which were age, duration of perfusion, nature of operation, cardiac rhythm and presence of the thrombi or calcification and hypothermic arrest. But many unknown etiological factors are remained out of our sight. A significant increase in the incidence of neurological damage was shown in older age group [13.3% in over 40 year of age], and also the duration of the bypass was associated with subsequent neurological injury especially more than 120 minutes [11.6%]. The presence of atrial fibrillation with intracardiac thrombi or calcification was also a contributing factor to developing neurological complication [16.7%]. These factors were regarded to influence the postoperative neurological complications and more effective method for prevention of these neurologic complication should be studied.

• Phonetics and Speech Sciences
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• v.3 no.3
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• pp.77-88
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• 2011

Foreign accent in second language production depends heavily on the transfer of features from the first language. This study examines acoustic variations in segments and suprasegments by native and nonnative speakers of English, searching for patterns of the transfer and plausible indexes of foreign accent in English. The acoustic variations are analyzed with recorded read speech by 20 native English speakers and 50 Korean learners of English, in terms of vowel formants, vowel duration, and syllabic variation induced by stress. The results show that the acoustic measurements of vowel formants and vowel and syllable durations display difference between native speakers and nonnative speakers. The difference is robust in the production of lax vowels, diphthongs, and stressed syllables, namely the English-specific features. L1 transfer on L2 specification is found both at the segmental levels and at the suprasegmental levels. The transfer levels measured as groups and individuals further show a continuum of divergence from the native-like target. Overall, the eldest group, students who are in the graduate schools, shows more native-like patterns, suggesting weaker foreign accent in English, whereas the high school students tend to involve larger deviation from the native speakers' patterns. Individual results show interdependence between segmental transfer and prosodic transfer, and correlation with self-reported proficiency levels. Additionally, experience factors in English such as length of English study and length of residence in English speaking countries are further discussed as factors to explain the acoustic variation.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.179-186
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• 2009

This paper presents an approach to classify normal and Ventricular Tachycardia/Ventricular Fibrillation(VT/VF) from the Creighton University Ventricular Tachyarrhythmia DataBase(CUDB) using the neural network with weighted fuzzy membership functions(NEWFM). In the first step, wavelet transform is used for producing input values which are used in the next step. In the second step, two numbers of input features are extracted by phase space reconstruction method and peak extraction method using coefficients produced by wavelet transform in the previous step. NEWFM classifies normal and VT/VF beats using two numbers of input features, and then the accuracy rate is 90.13%.

• Proceedings of the KSPS conference
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• 2004.05a
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• pp.245-249
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• 2004

The aim of this paper is to show the possibilities of the proficiency -based and integrated teaching of High School English reading and listening based on sense group and utterance restructuring. The proficiency -based and integrated listening and reading activities in stages are as follows. Step1, students fill in the blanks with strong or weak sounding words according to their abilities. Step2, speak along (track) based on restructuring and post-lexical phenomena while listening to the sentence. Step3, read and understand directly the passage, which have been marked the differentiated places where a native speaker of English would beat all likely to pause. Students need to listen to spoken English, so they recognize words in written and spoken form. They must be familiar with suprasegmental features, stress and rhythm, and post-lexical phenomena during reading activities.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.22 no.2
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• pp.111-114
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• 2011

All singers can often develop voice trouble secondary to vocal abuse and overuse, but it is well known that traditional Korean singer (pansori) develop voice disorders more frequently than western style sunger. While laryngological concern for voice disorders arising in professional singers has received some attention, empirically motivated investigations of the underlying acoustic features of the singing voice have been relatively limited. Since all singers have a good knowledge of the voice and voice training, they would hardly give consent for treatment to a doctor unless he understood their desire to maximize their voice quality. The components of this report are composed of breathing, basic ekement, and vocalization, essencial fact, for getting a perfect voice for pansori. The breathing is based on hypogastric breathing. The main functions of breathing are energy and power of utterence, tempo of rhythm and seperating paragraph and controlling feelings according to dramatic situation. Vocalization is based on general vocalization. Main uses of it are maintaining singer's tone and harmony of cosmetic dual force.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.104-108
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• 2016

African-American music heavily influences a variety of musical genres, including folk music, jazz, rhythm and blues, soul, and funk music. The music derived from traditional African music with its unique syncopated rhythm using a five-note pentatonic scale, and has developed through significant influences from gospel music. African-American music has also evolved through historical social movements, such as eliminating the racial discrimination, and has been influenced by the personalities of different cities in the United States. Modern music features fusion with elements of Western music. One of the most influential and respected artists of the 20th century was Stevie Wonder, who was known as "Father of African-American music." He was an accomplished artist, winning numerous awards despite being disabled. He has become one of the most famous and respected artists worldwide. This study of Stevie Wonder's life, music, and spiritual strength, aims to highlight his significant achievements and contributions to pop music. This is a study based on an analysis of the work of Stevie Wonder and describes how elements of African-American music influences current Korean pop music and musicians.