• 제목/요약/키워드: quality adaptation

검색결과 532건 처리시간 0.033초

Buffer-Based Adaptive Bitrate Algorithm for Streaming over HTTP

  • Rahman, Waqas ur;Chung, Kwangsue
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권11호
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    • pp.4585-4603
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    • 2015
  • Video streaming services make up a large proportion of Internet traffic on both fixed and mobile access throughout the world. Adaptive streaming allows for dynamical adaptation of the bitrate with varying network conditions, to guarantee the best user experience. Adaptive bitrate algorithms face a significant challenge in correctly estimating the throughput as it varies widely over time. In this paper, we first evaluate the throughput estimation techniques and show that the method that we have used offers stable response to throughput fluctuations while maintaining a stable playback buffer. Then, we propose an adaptive bitrate scheme that intelligently selects the video bitrates based on the estimated throughput and buffer occupancy. We show that the proposed scheme improves viewing experience by achieving a high video rate without taking unnecessary risks and by minimizing the frequency of changes in the video quality. Furthermore, we show that it offers a stable response to short-term fluctuations and responds swiftly to large fluctuations. We evaluate our algorithm for both constant bitrate (CBR) and variable bitrate (VBR) video content by taking into account the segment sizes and show that it significantly improves the quality of video streaming.

신규간호사의 직무 스트레스, 자아존중감, 회복탄력성이 현장적응에 미치는 영향 (The Influence of Job Stress, Self-Esteem, and Resilience on the Field Adaptation in Newly Graduated Nurses)

  • 손정은;김상희
    • 임상간호연구
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    • 제25권2호
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    • pp.151-160
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    • 2019
  • Purpose: This study aims to determine the relation among job stress, self-esteem, resilience, and field adaptation of the newly graduated nurses, through which an effective mediation strategy toward field adaptation and basic data on improving nursing quality can be established. Methods: The subjects were 110 newly graduated nurses who have worked at a tertiary hospital and a general hospital for less than 12 months. The data were collected, using self-reported questionnaires, from July 9 to July 31, 2018, and were analyzed by descriptive statistics, t-test, one-way ANOVA, $Scheff{\acute{e}}$ test, Pearson's correlation coefficient and stepwise multiple regression using an SPSS/WIN 24.0 program. Results: The study result showed that the newly graduated nurses' job stress, resilience, job satisfaction, and desired department influenced their field adaptation, explaining 60.2% of the variance in the field adaptation (F=42.14, p<.001). The nurses' job stress had the biggest influence on their field adaptation, explaining 38.7% of the variance. Conclusion: Human resource management strategy considering those influencing factors may improve the filed adaptation of newly graduated nurses and help them to retain in their work field.

모바일 환경을 위한 준-동적 디지털 비디오 어댑테이션 시스템 (Semi-Dynamic Digital Video Adaptation System for Mobile Environment)

  • 추진호;이상민;낭종호
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권10호
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    • pp.1320-1331
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    • 2004
  • 동영상 어댑테이션 시스템은 네트워크 제약, 클라이언트 제약 등을 만족하면서, 동영상의 품질이 최대가 되도록 동영상을 변환해 주는 시스템을 말한다. 본 논문에서는 정적으로 중간 동영상과 품질측정에 관한 정보를 생성해두는 준-동적 어댑테이션 시스템을 제안한다. 중간 동영상은 원본 동영상의 해상도를 반으로 줄여가며 생성되어, 서버에 저장된다. 품질 측정에 관한 정보는 프레임 율 별 부드러운 정도의 수치와, 픽셀 당 비트 량 별 선명한 정도의 수치에 대한 테이블을 정적으로 생성해 둔 것이다. 이런 중간 결과물들은 클라이언트에서의 서비스 품질을 고려하며 동적으로 동영상을 변환 할 때 가능한 빠르게 동영상 변환이 수행될 수 있도록 해준다. 실험 결과 제안된 어댑테이션 시스템은 기존의 동적 어댑테이션 시스템에 비해 약 30배정도 빠르게 어댑테이션을 수행하는 반면, 약 2%정도의 품질 저하가 있었고 중간동영상을 저장하기 위한 추가적인 서버공간이 필요하다는 것을 확인 할 수 있었다.

음성신호에 대한 트리 코우딩 (Tree Coding of Speech Signals)

  • 김경수;이상욱
    • 한국통신학회:학술대회논문집
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    • 한국통신학회 1984년도 춘계학술발표회논문집
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    • pp.18-21
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    • 1984
  • In this paper, the tree coding using the (M, L) multi-path search algorithm has teen investigated. A hybrid adaptation scheme which employs a block adaptation as well as a sequential dadptation is described for application in quantization and compression of speech signals. Simulation results with the gybrid adaptation scheme indicate that a relatively good speech quality can be obtained at rate about 8Kbps. All necessary parameters such as MlL and filter-order were found from simulation and these parameters turned out to be a good compromise between the complexity and overall performance.

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A Metadata-enabled Approach for Scalable Video Streaming in Heterogeneous Networks

  • Thang, Truong Cong;Le, Hung T.;Nguyen, Duc V.;Pham, Anh T.
    • Journal of Multimedia Information System
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    • 제2권1호
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    • pp.153-162
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    • 2015
  • In today's pervasive computing environments, multimedia content should be adapted to meet various conditions of network connections, terminals, and user characteristics. Scalable Video Coding (SVC) is a key solution for video communication over heterogeneous networks, where user terminals have different capabilities. This paper presents a standard-compliant approach that adapts an SVC bitstream to support multiple users. The adaptation problem is formulated as an optimization problem, focusing on the tradeoff between qualities of different spatial layers of an SVC video. Then the adaptation process is represented by standard metadata of MPEG-21, which can be solved by universal processing to enable interoperable and automatic operation. Our approach provides the users with optimal quality, a wide flexibility, and seamless adaptation. To the best of our knowledge, this is the first study that shows the adaptation tradeoff between spatial layers of a conforming SVC bitstream.

코로나19(COVID-19) 이후 뷰티학과 전문대 학생들의 회복탄력성과 대학생활적응의 관계에서 그릿(Grit)의 매개 효과 (Mediating Effect of Grit in the Relationship between Resilience and University Life Adaptation of College Students Majoring in Beauty after COVID-19)

  • 김민희;김나연
    • 한국의류산업학회지
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    • 제24권6호
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    • pp.789-800
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    • 2022
  • This study investigates the effect of recovery elasticity of beauty college students on university life adaptation during COVID-19. Further, the mediating effect of grit in relation to recovery elasticity and university life adaptation is analyzed. Survey data of 223 students (female: 192; male: 31) were collected for multiple and intermediate regression analyses using SPSS 24.0. The results reveal a static correlation between the lower factors of resilience, glittery, and adaptation to college life and that the resilience of junior college students in the beauty department had a static effect on grit and their adaptation to college life. Passion, a subordinate factor of grit, is mediated by the effect of grit on the relationship between resilience and adaptation to university life. However, perseverance, another subordinate factor of grit, did not have any such mediating effect. These results confirm the importance of grit, particularly passion, for resilience and adaptation to college life. It was confirmed that resilience was due to college life adaptation of beauty department students, and it was confirmed that passion, a sub-factor of grit, also had a mediating effect. Therefore, it is judged that resilience induces physical and mental adaptation, interpersonal adaptation, and academic adaptation necessary for college life, and works in many ways to improve the quality of life of beauty department junior college students. Instructors should consider developing educational programs for improving recovery elasticity and grit to help students better adapt to university life.

사별가족의 가족 탄력성, 사회적지지, 죽음인식, 죽음의 질이 사별 적응에 미치는 영향 (The Effect of Family Resilience, Social Support and Death Recognition on Quality of Death on the Adaptation of Bereavement Family)

  • 허현점;권영채
    • 디지털융복합연구
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    • 제17권12호
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    • pp.271-280
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    • 2019
  • 본 연구는 사별가족의 탄력성과 사회적지지, 죽음에 대한 인식, 죽음의 질이 사별 적응에 어떤 영향을 미치는지 살펴보고자 실시하였다. 자료수집은 2018년 4월 21일부터 5월 30일까지 B시와 K지역에서 가족사별을 경험한 대상자들에게 눈덩이 표추럽을 이용하여 236명에게 자가보고 서문지를 배포하였다. 자료분석 방법은 SPSS Win 22.0 프로그램을 이용하여 기술통계, t-test, ANOVA. 상관관계, 위계적 다중 회귀분석으로 분석하였다. 연구결과 사별적응 정도는 3.5점, 가족탄력성은 3.8점으로 하부영역으로는 신념체계가 3.9점으로 가장 높았다. 사회적 지지가 높을수록 사별적응을 잘 할 것이다는 기각되었으나 가족 탄력성에서 신념체계, 죽음인식, 죽음의 질이 사별적응에 영향을 미치는 것으로 나타났다. 본 연구 결과를 토대로 사별가족을 위한 사회적 지지망을 구축하고 죽음준비교육과 웰다잉을 위한 교육 등 죽음이 보다 아름답고 존엄한 죽음이 되기 위한 프로그램 마련 및 교육에 필요한 기초자료로 활용하고자 한다.

국내 모성적응증진 프로그램의 효과에 대한 체계적 문헌고찰 (Effect of Intervention Programs for Improving Maternal Adaptation in Korea: Systematic Review)

  • 송주은;안정아
    • 여성건강간호학회지
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    • 제19권3호
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    • pp.129-141
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    • 2013
  • Purpose: The purpose of this study was to determine the current state of nursing intervention for maternal adaptation and its' effectiveness in Korea by utilizing a systematic review. Methods: The PICO(Population-Intervention-Compar ator-Outcome) strategy was established, and 1,720 pieces of literature published during the last ten-year period from four electronic databases were reviewed. Eighteen references that met inclusion and exclusion criteria were finally selected for systematic review. The quality of references using critical appraisal checklist for experimental studies were evaluated, and then systematic review and meta-analysis were conducted. Results: All 18 references were quasi-experimental research design. Most interventions were provided at the hospital and postpartum care center. Maternal adaptation interventions appeared to be of many types, and particularly maternal role education programs were the most common. Confidence in maternal role was used as the most common variable for the maternal adaptati on. Various interventions for helping maternal adaptation in the postnatal period improved maternal confidence, moth er-infant attachment, maternal satisfaction and mother-infant interaction effectively. Conclusion: A diversity of nursin g interventions in postnatal period improved various aspects of maternal adaptation. Randomized controlled trials and longitudinal studies are needed in order to verify the effect of interventions for maternal adaptation more clearly.

제주특별자치도 상수도 기후위기 적응대책 연구 (A study on adaptation measures to climate crisis for water supply system of Jeju Special Self-Governing Province)

  • 김진근
    • 상하수도학회지
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    • 제37권6호
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    • pp.447-456
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    • 2023
  • Risk assessment on Jeju Special Self-Governing Province(JSSGP)'s water supply facilities and establishment of adaptation measures for climate crisis factors were implemented. JSSGP's vulnerability to the climate crisis was high in the order of drought, heat wave, heavy rain and strong wind. As a drought adaptation measure, policies of water saving and revenue water ratio improvement were considered. As for the heat wave adaptation measure, the introduction of an advanced water treatment process was suggested in response to the increase of algae cell number which resulting in taste and odor problem. As for heavy rain adaptation measures, the installation and operation of automatic coagulant injection devices for water purification plants that take turbid surface water were proposed. As a measure to adapt to strong winds, stabilization of power supply such as installation of dual power line was proposed in preparation for power outages. It is expected that water facilities will be able to supply high-quality tap water to customers even under extreme climate conditions without interruption through risk assessment for climate crisis factors and active implementation of adaptation measures.

Domain Adaptation 방법을 이용한 기계학습 기반의 미세먼지 농도 예측 (Machine Learning-based Estimation of the Concentration of Fine Particulate Matter Using Domain Adaptation Method)

  • 강태천;강행봉
    • 한국멀티미디어학회논문지
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    • 제20권8호
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    • pp.1208-1215
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    • 2017
  • Recently, people's attention and worries about fine particulate matter have been increasing. Due to the construction and maintenance costs, there are insufficient air quality monitoring stations. As a result, people have limited information about the concentration of fine particulate matter, depending on the location. Studies have been undertaken to estimate the fine particle concentrations in areas without a measurement station. Yet there are limitations in that the estimate cannot take account of other factors that affect the concentration of fine particle. In order to solve these problems, we propose a framework for estimating the concentration of fine particulate matter of a specific area using meteorological data and traffic data. Since there are more grids without a monitor station than grids with a monitor station, we used a domain adversarial neural network based on the domain adaptation method. The features extracted from meteorological data and traffic data are learned in the network, and the air quality index of the corresponding area is then predicted by the generated model. Experimental results demonstrate that the proposed method performs better as the number of source data increases than the method using conditional random fields.