• Title/Summary/Keyword: Audio quality evaluation

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Optimal Design of Acoustical Characteristics of Passenger Compartment (차실 음향 최적 설계에 관한 연구)

  • 김정수;강연준
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.183-188
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    • 2003
  • This study is to make the fundamentals of sound quality evaluation in regard of acoustical characteristics of passenger compartment. The deviation of frequency response function level within audible frequency is evaluated at receiving point in the research of room acoustics. In this study, frequency response function is the one between speaker and driver's ear positions. The positions of driver and audio speakers are optimized by analysis of acoustic mode of acoustic cavity. The main reflection planes are determined by analysis sound ray path diffused at optimized speaker positions. Finally, designer selects acoustical material by analysis of absorption effect of acoustical materials on the main reflection planes in order to avoid to distortion and fluctuation of frequency response function..

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Design of the TCX module transform coefficients quantizer in AMR-WB+ codec using PVQ (PVQ 방식을 이용한 AMR-WB+ 코덱의 TCX 모듈 변환계수 양자화기 설계)

  • Park, Sang-Kuk;Park, Jung-Eun;Kang, Sang-Won
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.345-346
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    • 2007
  • In this paper, we propose a Pyramid VQ(PVQ) to quantize the transform coefficients of TCX module for the music improvement of AMR-WB+ codec. The proposed PVQ is compared to the $RE_8$ Lattice VQ used in the AHR-WB+ standard codec, demonstrating improvement 4% and 5.7%, respectively, in Mean Squared Error(MSE) and 3.3% and 4.7%, respectively, in Perceptual Evaluation of Audio Quality(PEAQ) by 8-dimensional and 16-dimensional Pyramid VQ.

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A digital Audio Watermarking Algorithm using 2D Barcode (2차원 바코드를 이용한 오디오 워터마킹 알고리즘)

  • Bae, Kyoung-Yul
    • Journal of Intelligence and Information Systems
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    • v.17 no.2
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    • pp.97-107
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    • 2011
  • Nowadays there are a lot of issues about copyright infringement in the Internet world because the digital content on the network can be copied and delivered easily. Indeed the copied version has same quality with the original one. So, copyright owners and content provider want a powerful solution to protect their content. The popular one of the solutions was DRM (digital rights management) that is based on encryption technology and rights control. However, DRM-free service was launched after Steve Jobs who is CEO of Apple proposed a new music service paradigm without DRM, and the DRM is disappeared at the online music market. Even though the online music service decided to not equip the DRM solution, copyright owners and content providers are still searching a solution to protect their content. A solution to replace the DRM technology is digital audio watermarking technology which can embed copyright information into the music. In this paper, the author proposed a new audio watermarking algorithm with two approaches. First, the watermark information is generated by two dimensional barcode which has error correction code. So, the information can be recovered by itself if the errors fall into the range of the error tolerance. The other one is to use chirp sequence of CDMA (code division multiple access). These make the algorithm robust to the several malicious attacks. There are many 2D barcodes. Especially, QR code which is one of the matrix barcodes can express the information and the expression is freer than that of the other matrix barcodes. QR code has the square patterns with double at the three corners and these indicate the boundary of the symbol. This feature of the QR code is proper to express the watermark information. That is, because the QR code is 2D barcodes, nonlinear code and matrix code, it can be modulated to the spread spectrum and can be used for the watermarking algorithm. The proposed algorithm assigns the different spread spectrum sequences to the individual users respectively. In the case that the assigned code sequences are orthogonal, we can identify the watermark information of the individual user from an audio content. The algorithm used the Walsh code as an orthogonal code. The watermark information is rearranged to the 1D sequence from 2D barcode and modulated by the Walsh code. The modulated watermark information is embedded into the DCT (discrete cosine transform) domain of the original audio content. For the performance evaluation, I used 3 audio samples, "Amazing Grace", "Oh! Carol" and "Take me home country roads", The attacks for the robustness test were MP3 compression, echo attack, and sub woofer boost. The MP3 compression was performed by a tool of Cool Edit Pro 2.0. The specification of MP3 was CBR(Constant Bit Rate) 128kbps, 44,100Hz, and stereo. The echo attack had the echo with initial volume 70%, decay 75%, and delay 100msec. The sub woofer boost attack was a modification attack of low frequency part in the Fourier coefficients. The test results showed the proposed algorithm is robust to the attacks. In the MP3 attack, the strength of the watermark information is not affected, and then the watermark can be detected from all of the sample audios. In the sub woofer boost attack, the watermark was detected when the strength is 0.3. Also, in the case of echo attack, the watermark can be identified if the strength is greater and equal than 0.5.

Phase-matched Harmonic Generation and Variable Slope Exponential Weighting for Virtual Bass System (위상 일치와 가변 지수 감쇠 가중치 부여 방법이 적용된 가상 저음 시스템)

  • Moon, Hyeongi;Park, Young-cheol;Whang, Young-soo
    • Journal of Broadcast Engineering
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    • v.21 no.6
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    • pp.889-898
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    • 2016
  • Virtual Bass System (VBS) is widely used to extend the lower frequency limit of small loudspeakers, which generates harmonics of a fundamental frequency. The perceptual quality of the VBS is highly dependent on the harmonic weighting strategy. There have been several weighting methods, including exponential attenuation and timbre matching. However, it is essential to match phases between harmonics in the original signal and generate harmonics to precisely convey the weighting strategy. This paper shows the limitations of the previous harmonic weighting schemes and proposes a new harmonic weighting scheme. The proposed weighting scheme proposes phase matching between the original and generated harmonics and varies the slope of the attenuation weighting dynamically according to the missing fundamental frequency. Objective and subjective tests show that the proposed harmonic weighting scheme provides more natural and effective bass perception in a limited situation than the conventional schemes, which implies that the phase matching is essential for the high quality bass enhancement.

Speaker-Dependent Emotion Recognition For Audio Document Indexing

  • Hung LE Xuan;QUENOT Georges;CASTELLI Eric
    • 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.

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A Study on Evaluation of Environmental Characteristics of Maternity Room (산후관리시설의 산모실 환경특성평가에 관한 연구)

  • Hwang, Yeon-Sook;Son, Yeo-Rym
    • Korean Institute of Interior Design Journal
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    • v.16 no.6
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    • pp.47-55
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    • 2007
  • The purpose of this study is to evaluate environmental characteristics of maternity rooms. The method of this study is a field survey on 8 samples of postpartum care centers in Seoul. The plan, colors, materials, furniture and environmental characteristics of maternity rooms are analyzed. The characteristics of maternity rooms environment were categorized into four items; comfort, privacy, communication and dwelling. The results are as follows: Western-style and rooming-separation system of maternity rooms are used. Maternity rooms are generally good for dwelling quality but insufficient for communication. There are a lack of supply to control a temperature Individually in maternity rooms. It demands to make the type of one-sided public space between maternity room and living room for privacy. All of the maternity rooms surveyed are furnished with TV, radio, and telephone but, to improve communication with visitors, it is recommended that more convenient supplies such as audio and video system, chairs, and table be equipped. There are needs for sky-light windows in maternity rooms. It is necessary to research more about the space of living room, nursing room and service area, and we need more study about baby, nurser and owner' spaces.

An Analysis of User Experience of Metaverse Fashion Shows Based on Grounded Theory - Focusing on Schmitt's Experiential Marketing - (메타버스 패션쇼 이용자 경험 평가에 관한 근거 이론 연구 - 번 슈미트의 체험 마케팅을 중심으로 -)

  • Min-Ji Lee;Jung-Min Lee;Eunjung Shin
    • Fashion & Textile Research Journal
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    • v.25 no.5
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    • pp.578-592
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    • 2023
  • This study identified and evaluated by deriving and categorizing concepts related to the user experience of metaverse fashion shows using grounded theory, which is a qualitative research method. Based on experiential marketing theory, in-depth interviews were conducted for 14 days with 14 males and females in their 20s and 30s. The research results and contents are as follows: The causal condition was the purpose of using metaverse fashion shows, and the action/interaction strategy caused by such a case was found to be establishing a system for metaverse fashion shows and promoting a positive brand image. The results included content evaluation of satisfaction, normal, or dissatisfaction. The contextual condition was a change in the form of consumption that emphasized experience, while the interventional condition was psychological distance. Based on this, the core category was defined as "consumption patterns that emphasized the purpose of use and experience affects the metaverse fashion shows and psychological distance appeared as a user experience evaluation through the establishment of a system of metaverse fashion shows and the promotion of a positive brand image". User types were classified as active or passive. Active users have the autonomy to select content according to their individual preferences, and accordingly, their experience preference tends to change. In contrast, passive users' preference for the technical quality of content is relatively low, but they have a high concentration of content diversity and audio-visual interest elements.

Performance Evaluation of WiBro System based on AMC and H-ARQ by Simulation (AMC와 H-ARQ 에 따른 시뮬레이션 기반의 WiBro 시스템 성능 평가)

  • Seo, Won-Kyeong;Choi, Jae-In;Cho, You-Ze
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.1A
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    • pp.19-27
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    • 2011
  • WiBro is a wireless mobile communication system which supports a high data rate and high mobility in anywhere and anytime. Although WiBro system provides multimedia service including data, audio and video services, customers require better service quality in WiBro system. But, many researches have theoretically evaluated the performance of WiBro system without systematic studies by simulation. Therefore, in this paper, we evaluate a performance of WiBro system using OPNET simulator. We analyze system performance according to various modulation and coding schemes, and propose Adaptive Modulation and Coding (AMC) profile to support quality of services for user requirements. Also we evaluate the performance of WiBro system using AMC and Hybrid-Automatic Repeat Request (H-ARQ) technologies, and confirm that the proposed AMC profile can be applied to WiBro system with high performance.

Implementation of QoS-awared MAC Protocol for Home Networks (홈 네트워크를 위한 QOS 보장형 매체접속제어 프로토콜의 구현)

  • 황원주
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.2
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    • pp.228-238
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    • 2003
  • We believe that existing wire solutions such as HomePNA2.0 using phone lines and HomePlug using power line and wireless solution such as HomeRF are the most promising solutions, because of its cost-effectiveness. However, MAC protocols of these solutions provide only Class of Service(CoS) using priority mechanism like HomePNA and HomePlug or consider only voice among real-time traffics like HomeRF. For these reasons, we perceive the needs of the new MAC protocol which is no new wire solution and provides guaranteed Quality of Service (QoS) for not only voice but also video and audio. In light of this, we present the design and software implementation of a new MAC protocol for Home Networks. Our evaluation results of software implementation verify that proposed MAC protocol can provide low delay, low loss, and low jitter to real-time traffic by reserving bandwidth.

A Case Study on the Accessibility of Online Learning Content in Korea (국내 원격 교육 콘텐츠의 접근성 분석 사례)

  • 신승식
    • Proceedings of the Korea Contents Association Conference
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    • 2003.05a
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    • pp.92-101
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    • 2003
  • The accessibility evaluation of ten web-based loaming content in Korea was performed with the following procedure : (1) A primitive metric of the compliance of those contents to the WCAG (Web Content Accessibility Guidelines) 1.0 was obtained using Bobby, a widely used accessibility checker. (2) SGML validation test was carried out. (3) The contents were rendered with various browsers including a text-mode browser. (4) They were manually checked as to whether they satisfy the accessibility criteria proposed by W3C. Most of the tested contents scored low marks in all the test categories partly because they were apparently developed with little attention paid to web standard conformance, browser compatibility, and device-independence. They also put heavy emphasis on audio-visual effects catering only to the best-equipped users and offering no alternate access route for those in restricted environment. As more information and learning materials are delivered through the Internet, these low accessible contents would lead to a deeper information divide. The accessibility needs to be regarded as an important factor in evaluating the quality of loaming content.

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