• Title/Summary/Keyword: Voice quality

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BS-PLC(Both Side-Packet Loss Concealment) for CELP Coder (CELP 부호화기를 위한 양방향 패킷 손실 은닉 알고리즘)

  • Lee In-Sung;Hwang Jeong-Joon;Jeong Gyu-Hyeok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.12
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    • pp.127-134
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    • 2005
  • Lost packet robustness is an most important quality measure for voice over IP networks(VoIP). Recovery of the lost packet from the received information is crucial to realize this robustness. So, this paper proposes the lost packet recovery method from the received information for real-time communication for CELP coder. The proposed BS-PLC (Both Side Packet Loss Concealment) based WSOLA(Waveform Shift OverLab Add) allow the lost packet to be recovered from both the 'previous' and 'next' good packet as the LP parameter and the excitation signal are respectively recovered. The burst of packet loss is modeled by Gilbert model. The proposed scheme is applied to G.729 most used in VoIP and is evaluated through the SNR(signal to noise) and the MOS(Mean Opinion Score) test. As a simulation result, The proposed scheme provide 0.3 higher in Mean Opinion Score and 2 dB higher in terms of SNR than an error concealment procedure in the decoder of G.729 at $20\%$ average packet loss rate.

Implementation of Analysis System for H.323 Traffic (H.323 트래픽 분석 시스템의 개발)

  • Lee Sun-Hun;Chung Kwang-Sue
    • The KIPS Transactions:PartC
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    • v.13C no.4 s.107
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    • pp.471-480
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    • 2006
  • Recently, multimedia communication services, such as video conferencing and voice over IP, have been rapidly spread. H.323 is an international standard that specifies the components, protocols and procedures that provide multimedia communication services of real-time audio, video, and data communications over packet networks, including IP based networks. H.323 is applied to many commercial services because it supports various network environments and has a good performance. But communication services based on H.323 may have some problem because of current network trouble or mis-implementation of H.323. The understanding of this problem is a critical issue because it improves the quality of service and is easy to service maintenance. In this paper, we implement the analysis system for H.323 protocol wihch includes H.245, H.225.0, RTP, RTCP, and so on. Tills system is able to capture, parse, and present the H.323 protocol in real-time. Through the operation test and performance evaluation, we prove that our system is a useful to analyze and understand the problems for communication services based on H.323.

A Comparison Research on the Expected Satisfaction and Actual Satisfaction on VOC of one General Hospital (서울소재 일개 종합병원의 CRM에 대한 기대만족도와 실제만족도 비교와 VOC활용)

  • Ma, Yeon-Ji;Kim, Jeong-Ah;Park, Seung-Woo;Oh, Eun-Hwa;Moon, So-Young;Rhee, Hyun-Sill
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.3
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    • pp.1146-1152
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    • 2010
  • The Korean healthcare industry is rapidly changing along with the competition among hospitals. In the past, hospitals could make profit without designing competitive management strategies. Thus, they did not find importance in listening to customers' voices and identifying their wants. However, nowadays, the increasingly intense competition is encouraging hospitals to seriously consider competitive management strategies and Customer Relationship Management (CRM) activities to gain a competitive advantage and prosper. It tries to compare the expected satisfaction with the satisfaction of out-patient and in-patient and analysis of VOC(Voice of Customer). This survey was done from 27th, April, 2009 to 8th May and each 100 in-patients and out-patients. The paired t-test and descriptive analysis was used to analysis between before and after satisfaction. The result, the replied out-patients were the highest of I.M department, 43% and in-patients, surgery and other department are the highest each 22.0%. Nurses kindness is statistical significant in out-patients. Doctor, Nurse and staff's kindness and rounding service was statistical significant in in-patients. Totally, the satisfaction was lower than expected satisfaction, so the medical care institutions should analyst detailed the patient's satisfaction by VOC.

Theatricality of Absence: Male Identity and O'Neill's Self-reflection in Before Breakfast (부재의 연극성-『조식 전』에서 남성 정체성과 오닐의 자기반영)

  • Park, Jungman
    • Journal of English Language & Literature
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    • v.58 no.2
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    • pp.249-277
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    • 2012
  • Eugene O'Neill's one-act play Before Breakfast (1916) depicts a morning scene of a married couple who live in a slovenly flat at Greenwich Village. There is no apparent dramatic action occurring in the play. Instead, the play is full of Mrs. Rowland's incessant complaints about her husband Alfred's loafing around bars with artists friends, neglecting his role as breadwinner. An irony is that every morning she prepares breakfast for the good-for-nothing husband even in the moment of complaining. It is worth noting that Alfred is an 'unseen character' who is never directly observed by the audience but is only described by her wife. Deprived of all chances to speak and present himself on stage, he is kept in the room throughout the play. In contrast, Mrs. Rowland dominates the stage, monopolizing language and action. The audience has to listen to her, judge from her statements, and take her one-sided complaints. The accused husband, with zero chance of showing up and defending himself, has no choice but to be the sinner as the wife intends. Another irony is that the audience's feeling about the situation is quite different from what is expected. The wife's complaints are regarded to be unfair and groundless in the reason that the situation is monopolized by her. In case of the husband, in contrast, the loss of voice and presence stresses the injustice of his dead-lock situation. In other words, the 'absent' quality of Alfred works to evoke the audience's sympathy for himself and subsequently makes his presence recognized, not visually but emotionally, by the audience throughout the play. Discovered in this paradoxical moment where the spectators understand or 'see' the status of the unseen and the devoiced message is successfully conveyed to the listeners, is the theatricality of absence. Adding to the function as theatrical device, the 'unseen character' Alfred works as a device of self-reflection to mirror the author's own life. Alfred, the alter-ego of O'Neill, effectively exorcises the author's life-long feeling of guilty as the unfaithful husband and father in the unhappy first marriage, successfully evoking the audience's sympathy for himself.

Effects of Smart Home on Performance and Satisfaction of Activities of Daily Living of Wheelchair Users (스마트 홈이 휠체어를 사용하는 장애인의 일상생활활동 수행도와 만족도에 미치는 영향)

  • Woo, Ji-Hee;Kim, Jeong-Hyun;Kim, Jongbae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.242-248
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    • 2019
  • This study was conducted to examine the effects of a smart home (electronic control unit, ECU) on the performance and satisfaction of activities of daily living of wheelchair users. A total of 15 wheelchair users (10 patients with spinal cord injury and 5 patients with stroke) were investigated. Smart homes were equipped with ECU technology, which consisted of automation of furniture and products. The products and facilities were integrated and controlled by a smart device or voice. Performance and satisfaction of activities of daily living were measured by the Canadian Occupational Performance Measure (COPM) before and after residence in a smart home. All participants showed a higher COPM (performance score ${\geq}3$, satisfaction score ${\geq}4$) during residence in a smart home compared to residence in the current home. In addition, the COPM scores differed significantly before and after residence in a smart home. These results provide evidence of the applicability of smart homes based on high technology. However, additional studies of more smart home participants should be conducted to improve the quality of the results.

Evaluation of the Subjective Acoustic Performance of University Small Hall Remodeled as a Lecture Room : Based on the case of the W University (강의전용 공간으로 리모델링된 대학 소공연장의 주관적 음향성능 평가 : W대학의 사례를 바탕으로)

  • Kim, Min-Ju;Kim, Jae-Soo
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.19 no.4
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    • pp.40-49
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    • 2020
  • Recently, the form of education has changed from one-way to two-way and mutual exchange rather than the existing one-way order form, and accordingly, it is necessary to consider creating a suitable learning environment for each type of education. The basic form of education consists of the delivery of knowledge, that is, the delivery of knowledge by teachers to education consumers through voice delivery, so the sound environment is considered an essential factor in creating a pleasant learning environment. The indoor sound environment is very closely related to the mental stress of the inmate, so the quality level of education will also change greatly depending on whether or not the appropriate sound environment is created. However, the importance of the sound environment in educational facilities such as classrooms has not been highlighted due to the lack of research and related laws on the sound environment. Therefore, in this study, auditory tests were conducted using the auralization based on the physical acoustic performance data presented in the preceding study. Through this, we wanted to verify the validity of this research by analyzing the subjective acoustic performance satisfaction of the occupants due to the improvement of the physical acoustic performance. Based on these research results, it is estimated that the improvement of the sound environment of educational facilities through remodeling in the future will be possible to verify whether the sound environment suitable for educational facilities is created only after the analysis stage on the improvement of subjective sound performance as well as physical sound performance.

Blind Rhythmic Source Separation (블라인드 방식의 리듬 음원 분리)

  • Kim, Min-Je;Yoo, Ji-Ho;Kang, Kyeong-Ok;Choi, Seung-Jin
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.8
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    • pp.697-705
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    • 2009
  • An unsupervised (blind) method is proposed aiming at extracting rhythmic sources from commercial polyphonic music whose number of channels is limited to one. Commercial music signals are not usually provided with more than two channels while they often contain multiple instruments including singing voice. Therefore, instead of using conventional modeling of mixing environments or statistical characteristics, we should introduce other source-specific characteristics for separating or extracting sources in the under determined environments. In this paper, we concentrate on extracting rhythmic sources from the mixture with the other harmonic sources. An extension of nonnegative matrix factorization (NMF), which is called nonnegative matrix partial co-factorization (NMPCF), is used to analyze multiple relationships between spectral and temporal properties in the given input matrices. Moreover, temporal repeatability of the rhythmic sound sources is implicated as a common rhythmic property among segments of an input mixture signal. The proposed method shows acceptable, but not superior separation quality to referred prior knowledge-based drum source separation systems, but it has better applicability due to its blind manner in separation, for example, when there is no prior information or the target rhythmic source is irregular.

Attitude Confidence and User Resistance for Purchasing Wearable Devices on Virtual Reality: Based on Virtual Reality Headgears (가상현실 웨어러블 기기의 구매 촉진을 위한 태도 자신감과 사용자 저항 태도: 가상현실 헤드기어를 중심으로)

  • Sohn, Bong-Jin;Park, Da-Sul;Choi, Jaewon
    • Journal of Intelligence and Information Systems
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    • v.22 no.3
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    • pp.165-183
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    • 2016
  • Over the past decade, there has been a rapid diffusion of technological devices and a rising number of various devices, resulting in an escalation of virtual reality technology. Technological market has rapidly been changed from smartphone to wearable devices based on virtual reality. Virtual reality can make users feel real situation through sensing interaction, voice, motion capture and so on. Facebook.com, Google, Samsung, LG, Sony and so on have investigated developing platform of virtual reality. the pricing of virtual reality devices also had decreased into 30% from their launched period. Thus market infrastructure in virtual reality have rapidly been developed to crease marketplace. However, most consumers recognize that virtual reality is not ease to purchase or use. That could not lead consumers to positive attitude for devices and purchase the related devices in the early market. Through previous studies related to virtual reality, there are few studies focusing on why the devices for virtual reality stayed in early stage in adoption & diffusion context in the market. Almost previous studies considered the reasons of hard adoption for innovative products in the viewpoints of Typology of Innovation Resistance, MIR(Management of Innovation Resistant), UTAUT & UTAUT2. However, product-based antecedents also important to increase user intention to purchase and use products in the technological market. In this study, we focus on user acceptance and resistance for increasing purchase and usage promotions of wearable devices related to virtual reality based on headgear products like Galaxy Gear. Especially, we added a variables like attitude confidence as a dimension for user resistance. The research questions of this study are follows. First, how attitude confidence and innovativeness resistance affect user intention to use? Second, What factors related to content and brand contexts can affect user intention to use? This research collected data from the participants who have experiences using virtual rality headgears aged between 20s to 50s located in South Korea. In order to collect data, this study used a pilot test and through making face-to-face interviews on three specialists, face validity and content validity were evaluated for the questionnaire validity. Cleansing the data, we dropped some outliers and data of irrelevant papers. Totally, 156 responses were used for testing the suggested hypotheses. Through collecting data, demographics and the relationships among variables were analyzed through conducting structural equation modeling by PLS. The data showed that the sex of respondents who have experience using social commerce sites (male=86(55.1%), female=70(44.9%). The ages of respondents are mostly from 20s (74.4%) to 30s (16.7%). 126 respondents (80.8%) have used virtual reality devices. The results of our model estimation are as follows. With the exception of Hypothesis 1 and 7, which deals with the two relationships between brand awareness to attitude confidence, and quality of content to perceived enjoyment, all of our hypotheses were supported. In compliance with our hypotheses, perceived ease of use (H2) and use innovativeness (H3) were supported with its positively influence for the attitude confidence. This finding indicates that the more ease of use and innovativeness for devices increased, the more users' attitude confidence increased. Perceived price (H4), enjoyment (H5), Quantity of contents (H6) significantly increase user resistance. However, perceived price positively affect user innovativeness resistance meanwhile perceived enjoyment and quantity of contents negatively affect user innovativeness resistance. In addition, aesthetic exterior (H6) was also positively associated with perceived price (p<0.01). Also projection quality (H8) can increase perceived enjoyment (p<0.05). Finally, attitude confidence (H10) increased user intention to use virtual reality devices. however user resistance (H11) negatively affect user intention to use virtual reality devices. The findings of this study show that attitude confidence and user innovativeness resistance differently influence customer intention for using virtual reality devices. There are two distinct characteristic of attitude confidence: perceived ease of use and user innovativeness. This study identified the antecedents of different roles of perceived price (aesthetic exterior) and perceived enjoyment (quality of contents & projection quality). The findings indicated that brand awareness and quality of contents for virtual reality is not formed within virtual reality market yet. Therefore, firms should developed brand awareness for their product in the virtual market to increase market share.

Applying QFD in the Development of Sensible Brassiere for Middle Aged Women (QFD(품질 기능 전개도)를 이용한 중년 여성의 감성 Brassiere 개발)

  • Kim Jeong-hwa;Hong Kyung-hi;Scheurell Diane M.
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.12 s.138
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    • pp.1596-1604
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    • 2004
  • Quality Function Deployment(QFD) is a product development tool which ensures that the voice of the customer needs is heard and translated into products. To develop a sensible brassiere for middle-aged women QFD was adopted. In this study the applicability and usefulness of QFD was examined through the engineering design process for a sensible brassiere for middle-aged women. The customer needs for the wear comfort of brassiere was made by one-on-one survey of 100 women who aged 30-40. The customer competitive assessment was generated by wearing tests of 10 commercial brassieres. The subjective assessment was conducted in the enviornmental chamber that was controlled at $28{\pm}1^{\circ}C,\;65{\pm}3\%RH.$ As a results, we developed twenty-one customer needs and corresponding HOWs for the wear comfort of brassiere. The Customer Competitive Assessment was generated by wearing tests of commercial brassiere. The subjective measurement scale and dimension for the evaluation of sensible brassiere were extracted from factor analysis. Four factors were fitting, aesthetic property, pressure sensation, displacement of brassiere due to movement. The most critical design parameter was wire-related property and second one was stretchability of main material of brassiere. Also, wearing comfort of brassiere was affected by the interaction of initial stretchability of wing and support of strap. Engineering design process, QFD was applicable to the development of technical and aesthetic brassieres.

A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.