• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.229-234
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• 2002

OFDM(Orthogonal Frequency Division Multiplexing) 전송방식은 SCM(Single Carrier Modulation)에 비해 우수한 여러 가지 장점들을 가지며, 방송시스템들 중 Eureka 147 DAB(Digital Audio Broadcasting) 시스템에 가장 먼저 채택되었다. 그러나 OFDM 신호의 높은 PAPR(Peak-to-Average Power Ratio) 특성은 D/A, A/D 변환기의 복잡도를 높이고, 고출력 증폭기의 효율성을 감소시키는 원인이 된다. 이를 개선하기 위한 방법 중에, SDT(Signal Distortion Technique)는 전송시스템의 규격 및 수신기의 변경 없이도 적용 가능하다는 장점을 갖는다. 본 논문에서는 SDT에 속하는 companding 기법을 Eureka 147 DAB 시스템에 적용하여 PAPR 개선정도에 따른 시스템의 요구 $E_2/N_0$ 및 out-of-band의 PSD 열화 정도를 분석하였으며, 이를 clipping 기법의 성능과 비교하였다. 모의실험 결과, $\mu$값이 2인 경우, companding 기법이 PAPR, $E_2/N_0$, out-of-band의 PSD 특성 모두에서 clipping 기법에 비해 우수한 성능을 나타냈다. 또한 $\mu$ 값을 고정시킨 경우, 정규화 값이 증가할수록 신호왜곡 정도가 줄어들어 $E_2/N_0$, out-of-band의 PSD 성능개선 정도는 증가하지만, 이와는 반대로 PAPR 값은 개선 정도가 줄어들었다.

• The Journal of the Korea Contents Association
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• v.10 no.12
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• pp.43-50
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• 2010

In this thesis, Traffic information which is provided to the VMS used a FM frequency and provides real-time traffic information about the mobile production unit system which designed and produced and a quality evaluated. Result of the research, we will be able to confirm converted audio and text information from traffic information is linked with VMS information, FM broadcast traffic information to motorists passing through it were found to be and as a result of this study, which sees raises the effectiveness of VMS users and using VMS to build low-cos transport infrastructure will be an opportunity.

• Proceedings of the IEEK Conference
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• summer
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• pp.92-96
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• 2004

The researches of the emotions are currently great interest in speech processing as well as in human-machine interaction domain. In the recent years, more and more of researches relating to emotion synthesis or emotion recognition are developed for the different purposes. Each approach uses its methods and its various parameters measured on the speech signal. In this paper, we proposed using a short-time parameter: MFCC coefficients (Mel­Frequency Cepstrum Coefficients) and a simple but efficient classifying method: Vector Quantification (VQ) for speaker-dependent emotion recognition. Many other features: energy, pitch, zero crossing, phonetic rate, LPC... and their derivatives are also tested and combined with MFCC coefficients in order to find the best combination. The other models: GMM and HMM (Discrete and Continuous Hidden Markov Model) are studied as well in the hope that the usage of continuous distribution and the temporal behaviour of this set of features will improve the quality of emotion recognition. The maximum accuracy recognizing five different emotions exceeds $88\%$ by using only MFCC coefficients with VQ model. This is a simple but efficient approach, the result is even much better than those obtained with the same database in human evaluation by listening and judging without returning permission nor comparison between sentences [8]; And this result is positively comparable with the other approaches.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.335-338
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• 2002

본 연구에서는 주파수 영역에서의 확산 스펙트럼 방식을 이용한 오디오 워터마킹 기법을 사용하고 있다. 워터마크 삽입은 오디오 신호를 MCLT(Modulated Complex Lapped Transform)로 분석한 후, 특정 주파수 영역의 진폭에 삽입되며 추출은 상관도를 이용하여 추출하게 된다. 워터마크 삽입은 44.1 kHz의 음악에 80 bits의 정보가 4초 단위로 반복적으로 삽입되며, 추출에서는 무작위로 추출된 8초 분량의 오디오 신호로부터 80 bits 비트 열과의 상관도를 계산하여 선정된 문턱 값을 초과하게 되면 워터마크가 존재하는 것으로 판단하게 된다 피치 스케일에 대응하기 위하여 120개 정도의 탐색을 수행하며, 시간 스케일에 대응하기 위하여 상관도의 지역 최대 점을 추출하고, 이러한 지역 최대 점들로부터 추출된 비트 열과 실제 비트 열과의 상관도를 계산하게 된다. 그러나 추출된 비트 열은 삽입 에러와 삭제 에러를 가질 수 있기 때문에 이러한 비트 열과의 최대 상관도를 구하기 위하여 본 연구에서는 동적계획법에 의한 최대 상관도 추출 알고리즘을 제시한다. 제안된 방법은 피치 및 시간 스케일링 변환 뿐만 아니라, 오디오 압축에도 견고함을 보인다.

• The Research Journal of the Costume Culture
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• v.4 no.2
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• pp.173-185
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• 1996

The purpose of this study was to identify the relationship of clothing involvement and clothing buying behavior of women. A questionnaire was developed to measure clothing involvement, clothing purchasing motives, clothing purchasing criteria, fashion information sources, store selection criteria, and demographic characteristics. The questionnaire was administered to 430 female adults in Taegu. The data were analyzed using percentage, frequency, factor analysis, and t-test. The results of the study were s follows: 1. Subjects were divided into low clothing involved and high clothing involved groups. 2. Three dimensions of clothing purchasing motives were derived by factor analysis such as Aesthetic dependant, Impulsive, and Practical motive. Clothing purchasing criteria were factor analysed as Aesthetic, Qualitative, External, and Economical criterion. Fashion information sources were factor analysed as Printed & audio-visual oriented media, Marketer intensive search, Store search, Observation & Interpersonal search, and Experience. Store selection criteria were factor analyzed as Merchandise & Store atmosphere, Store convenience, and Brand & fashion. 3. There were significant differences between high involved and low involved consumers in clothing purchasing behavior. The high involved consumers showed more importance than low involved consumers about purchasing criteria expecially in aesthetic dependant. The high involved consumers put more importance to aesthetic, qualitative, and external criterion as clothing purchasing criteria. The high involved information sources. The high involved consumers were more concerned about merchandise & store atmosphere, and brand & fashion than low involved consumers in store selection criteria.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1285-1288
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• 2002

Bluetooth wireless technology is a publicly available specification proposed for Radio Frequency (RF) communication for short-range and point-to- multipoint voice and data transfer. It operates in the 2.4GHz ISM(Industrial, Scientific and Medical) band and offers the potential for low-cost, broadband wireless access for various mobile and portable devices at range of about 10 meters. In this paper, we describe the structure and the test results of the bluetooth baseband module we have developed. This module was developed based on IP reuse. So Interface of each module such as link controller UART, and audio CODEC is designed based on ARM7 comfortable processor. We also considered various interfaces of related external chips. The fully synthesizable baseband module was fabricated in a $0.25{\mu}m$ CMOS technology occupying $2.79{\times}2.8mm^2$ area including the ARM TDMI processor. And a FPGA implementation of this module is tested for file and bit-stream transfers between PCs.

• Asia Pacific Journal of Corpus Research
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• v.2 no.1
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• pp.13-22
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• 2021

The present study employed an analytical framework that is characterised by a synthesis of quantitative and qualitative analyses with a specially designed computer software SpeechActConc to examine speech acts in business communication. The naturally occurring data from the audio recordings and the prosodic transcriptions of the business sub-corpora of the HKCSE (prosodic) are manually annotated with a speech act taxonomy for finding out the frequency of fillers, the co-occurring patterns of fillers with other speech acts, and the linguistic realisations of fillers. The discoursal function of fillers to sustain the discourse or to hold the floor has diverse linguistic realisations, ranging from a sound (e.g. 'uhuh') and a word (e.g. 'well') to sounds (e.g. 'um er') and words, namely phrase ('sort of') and clause (e.g. 'you know'). Some are even combinations of sound(s) and word(s) (e.g. 'and um', 'yes er um', 'sort of erm'). Among the top five frequent linguistic realisations of fillers, 'er' and 'um' are the most common ones found in all the six genres with relatively higher percentages of occurrence. The remaining more frequent realisations consist of clause ('you know'), word ('yeah') and sound ('erm'). These common forms are syntactically simpler than the less frequent realisations found in the genres. The co-occurring patterns of fillers and other speech acts are diverse. The more common co-occurring speech acts with fillers include informing and answering. The findings show that fillers are not only frequently used by speakers in spontaneous conversation but also mostly represented in sounds or non-linguistic realisations.

• International Journal of Computer Science & Network Security
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• v.23 no.8
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• pp.9-16
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• 2023

Speech can actively elicit feelings and attitudes by using words. It is important for researchers to identify the emotional content contained in speech signals as well as the sort of emotion that resulted from the speech that was made. In this study, we studied the emotion recognition system using a database in Arabic, especially in the Saudi dialect, the database is from a YouTube channel called Telfaz11, The four emotions that were examined were anger, happiness, sadness, and neutral. In our experiments, we extracted features from audio signals, such as Mel Frequency Cepstral Coefficient (MFCC) and Zero-Crossing Rate (ZCR), then we classified emotions using many classification algorithms such as machine learning algorithms (Support Vector Machine (SVM) and K-Nearest Neighbor (KNN)) and deep learning algorithms such as (Convolution Neural Network (CNN) and Long Short-Term Memory (LSTM)). Our Experiments showed that the MFCC feature extraction method and CNN model obtained the best accuracy result with 95%, proving the effectiveness of this classification system in recognizing Arabic spoken emotions.

• The Journal of the Acoustical Society of Korea
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• v.29 no.4
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• pp.265-269
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• 2010

This paper proposes a novel spectral audio feature, spectral contrast MFCC (SCMFCC), and studies its performance on the musical genre classification. For a successful musical genre classifier, extracting features that allow direct access to the relevant genre-specific information is crucial. In this regard, the features based on the spectral contrast, which represents the relative distribution of the harmonic and non-harmonic components, have received increased attention. The proposed SCMFCC feature utilizes the spectral contrst on the mel-frequency cepstrum and thus conforms the conventional MFCC in a way more relevant for musical genre classification. By performing classification test on the widely used music DB, we compare the performance of the proposed feature with that of the previous ones.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.557-559
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• 2012

The fire distress detection and rescue user terminal, which rescue the survivor by using the direction finding of distress place and sensing techniques, was design and implemented. The user terminal provides the rescue function in the place of evil surroundings that can not be available the communication facilities. The rescue user terminal provides the portable configuration, which consists of a RF board with radio frequency of 2.45 GHz and inner antenna, and a control board. The inner antenna with $60^{\circ}$ or $120^{\circ}$ directivity, which use the triangulation, detects the rescue signal from survivor. The rescue was managed by allotment of user ID and can use the bidirectional audio channel using radio frequency of 5.8 GHz.