• Title/Summary/Keyword: Picture Quality

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The relation between phonetic differences of Korean learners' production of English vowels, pronunciation intelligibility and speaking proficiency test scores (한국인 학습자 영어 모음 발화의 음성학적 차이와 발음 이해도, 말하기 점수와의 관계)

  • Kim, Ji-Eun
    • Phonetics and Speech Sciences
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    • v.9 no.2
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    • pp.1-7
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    • 2017
  • The purpose of this study is to investigate the relations between phonetic differences among Korean learners' production of English front vowels, pronunciation intelligibility and speaking proficiency test score. To do so, thirty Korean university students were asked (1) to read English text book paragraphs and (2) describe a picture. Two English native raters and one Korean rater evaluated Korean subjects' English pronunciation intelligibility and speaking. In addition, subjects' English vowel productions were acoustically analyzed(F0, F1, F2, vowel duration, intensity). The results of the study show that the vowel quality and pitch of the unstressed vowels and lax vowel are related to the pronunciation intelligibility. In addition, the scores of pronunciation intelligibility and speaking are highly related.

Image Coding Using DCT and Block Hierarchical Segmentation Finite-State Vector Quantization (DCT와 블록 계층 분할 유한상태 벡터 양자화를 이용한 영상 부호화)

  • Jo, Seong-Hwan;Kim, Eung-Seong
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.3
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    • pp.1013-1020
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    • 2000
  • In this paper, we propose an algorithm which segments hierarchically blocks of image using discrete cosine transform(DCT) and execute finite-state vector quantization (FSVQ) for each block. Using DCT coefficient feature, image is segmented hierarchically to large smooth block and small edge block, then the block hierarchy informations are transmitted. The codebooks are respectively constructed for each hierarchical blocks, the encoder transmits codeword index using FSVQ for reducing encoded bit with hierarchical segmentation. Compared with side match VQ(SMVQ) and hierarchical FSVQ(HFSVQ) algorithm, about Zelda and Boat image, the new algorithm shows better picture quality with 1.97dB and 2.85 dB difference as to SMVQ, 1.78dB and 1.85dB diffences as to HFSVQ respectively.

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Video Rate Control Using An Adaptive Quantization Based on Spatio-temporal Activity Measure (시공간 활성도를 이용한 적응적 양자화 기반 비디오율 제어)

  • 이시웅;김차종
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.454-458
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    • 2004
  • A new algorithm for the rate control of videos considering the sensitivity of the human visual system is presented. The method adopts the three-step structure of MPEG2 TM5 rate control, and a new measure of macroblock activity based on spatio-temporal sensitivity is introduced for the adaptive quantization. Experimental results show that the spatio-temporal activity measure outperforms the spatial activity of TM5 in picture quality.

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A study on the Digital Video control system for train simulator (철도차량 시뮬레이션의 디지털 영상제어 시스템 연구)

  • Kim, Bong-Taek;Choi, Sung
    • Proceedings of the KSR Conference
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    • 1999.11a
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    • pp.259-266
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    • 1999
  • A study on the static type train simulator will include the training of new drives requires that the environment of the cab, controls placement, etc. must highly realistic so that driver can readily transfer his training experience to the real world. The simulator computer sends video disc speed command to a Video PC processor. A video switcher select the output of the on-line player. This selection is done with loss of vertical synchronization, meaning the picture will not noticeable roll or jump as the simulation mover from disc to disc. The video image quality remain contestant through the simulated speed range from zero to 100km/h. Flicker is avoided in the scene by the use of a TBC(Time Base Corrector) which causes the display of one video field at a time. Thus, no interfield jitter is present when the scene is stopped.

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Projection format and quality metrics of 360 video (360 VR 영상의 프로젝션 포맷 및 성능 평가 방식)

  • Park, Seong-Hwan;Kim, Kyu-Heon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2019.06a
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    • pp.182-184
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    • 2019
  • 최근 사용자에게 더욱 몰입감 있는 콘텐츠를 제공하기 위한 기술에 대한 관심이 증가하고 있으며 그 중 가장 대표적인 것이 360 VR 영상이라고 할 수 있다. 미디어 표준화 단체인 MPEG(Moving Picture Experts Group)에서는 MPEG-I(Immersive) 차세대 프로젝트 그룹을 이용하여 이러한 움직임에 대응하고 있다. MPEG-I는 2021년 말 6DoF VR 영상을 목표로 8개의 파트가 표준화를 진행중이다. 360 VR 영상의 경우 획득시 영상의 픽셀들이 3D 공간 상에 존재하게 되는데, 이를 처리 및 출력 하귀 위해서는 2D 영상으로 전환이 필요하며 이 때 사용되는 것이 Projection format이다. 현재 JVET(Joint Video Exploration Team)에서는 3D에서 2D로 전환이 이루어 질 때 손실을 최소화 하기 위한 Projection format들에 대한 연구가 이루어 지고 있다. 본 논문에서는 현재까지 제안된 다양한 Projection format들에 대하여 소개하고 이에 대한 성능 측정 방식에 대하여 소개한다.

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An Exploration of Learning Environmental Factors Affecting Student Cognitive Engagement: Implications for Instructional Design Research

  • LEE, Sunghye
    • Educational Technology International
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    • v.15 no.2
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    • pp.143-170
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    • 2014
  • As it was argued that students' cognitive engagement can be, at least in part, modified by individual or learning environmental factors, prior studies have attempted to identify the factors explaining the variability of students' cognitive engagement. This literature review has shown that students' cognitive engagement can be altered by various elements in the learning environment design such as factors related students' perceptions of teaching quality, characteristics of tasks and learning activities, teachers' behaviors during instruction, classroom goal structures, the integration of student oriented learning, action learning, problem-based learning, and constructivist learning, and academic disciplines. Based on the review, this study suggests that more studies are required to focus on understandings how the integration of instructional design principles into courses and the levels of student cognitive engagement in these courses are related. Also, an investigation of direct and indirect effect of learning environments taking into account students' personal factors would provide a more accurate picture of the relationship between learning environmental factors and students' cognitive engagement.

Quality of Life in Malay and Chinese Women Newly Diagnosed with Breast Cancer in Kelantan, Malaysia

  • Yusuf, Azlina;Hadi, Imi Sairi Ab.;Mahamood, Zainal;Ahmad, Zulkifli;Keng, Soon Lean
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.435-440
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    • 2013
  • Background: Breast cancer is the leading cause of cancer-related death among women in Malaysia. A diagnosis is very stressful for women, affecting all aspects of their being and quality of life. As such, there is little information on quality of life of women with breast cancer across the different ethnic groups in Malaysia. The purpose of this study was to examine the quality of life in Malay and Chinese women newly diagnosed with breast cancer in Kelantan. Materials and Methods: A descriptive study involved 58 Malays and 15 Chinese women newly diagnosed with breast cancer prior to treatment. Quality of life was measured using the Malay version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its breast-specific module (QLQ-BR23). Socio-demographic and clinical data were also collected. All the data were analyzed using SPSS version 20.0. Results: Most of the women were married with at least a secondary education and were in late stages of breast cancer. The Malay women had lower incomes (p=0.046) and more children (p=0.001) when compared to the Chinese women. Generally, both the Malay and Chinese women had good functioning quality-of-life scores [mean score range: 60.3-84.8 (Malays); 65.0-91.1 (Chinese)] and global quality of life [mean score 60.3, SD 22.2 (Malays); mean score 65.0, SD 26.6 (Chinese)]. The Malay women experienced more symptoms such as nausea and vomiting (p=0.002), dyspnoea (p=0.004), constipation (p<0.001) and breast-specific symptoms (p=0.041) when compared to the Chinese. Conclusions: Quality of life was satisfactory in both Malays and Chinese women newly diagnosed with breast cancer in Kelantan. However, Malay women had a lower quality of life due to high general as well as breast-specific symptoms. This study finding underlined the importance of measuring quality of life in the newly diagnosed breast cancer patient, as it will provide a broader picture on how a cancer diagnosis impacts multi-ethnic patients. Once health care professionals understand this, they might then be able to determine how to best support and improve the quality of life of these women during the difficult times of their disease and on-going cancer treatments.

The depth quality enhancement algorithm for Autostereoscopic 3D Monitor (무안경 3D 모니터를 위한 Depth 화질 향상 Algorithm)

  • Song, Sung-Ho;Lee, Kyoung-Il;Lee, Dong-Ha;Park, Jong-Cheol;Lee, Jea-Jun;Kim, Young-Kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.133-136
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    • 2012
  • In this paper, we found the many effective ways and apply for improve the 3D quality of Autostereoscopic 3D display products. Autostereoscopic products compared to traditional 3D glasses, the disadvantage is the poor depth of 3D picture quality and it only can see the fixed distance and position. So, for the compensate this disadvantage, we use the Head tracking technology and video placement algorithms and several techniques. In this paper, the will report on how to improve the Parallax Barrier Autostereoscopic 3D quality through the Head tracking of the user identification, video replacement algorithms and crosstalk improving method.

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Measurement of Flickering Artifact for H.264 with Periodic I-Frame Structure (주기적 I-프레임 구조의 H.264 부호화 동영상을 위한 플리커링 측정 알고리즘)

  • Lim, Jong-Min;Kang, Dong-Wook;Jung, Kyeong-Hoon
    • Journal of Broadcast Engineering
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    • v.15 no.3
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    • pp.321-331
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    • 2010
  • Most of multimedia video coding algorithms are lossy schemes and several kinds of spatial and temporal artifacts are inevitable. Flickering, which is the most typical coding artifact in time domain, is mainly due to fact that the quality of coded sequence fluctuates as the quantization parameter is adjusted for rate control. In this paper, we analyzed the effect of quality variation according to the characteristics of video sequence when the I-frames are periodically inserted. And we proposed the FR(Full Reference)-based assessment algorithm to measure the amount of flickering artifacts in the coded video. It is discovered that the flickering becomes critical when the level of quality is intermediate and is affected by the amount of detail or movement, the size of object, and camera parameters. The proposed measurement algorithm shows is well consistent with HVS(Human Visual System).

Mid-Term Performance of Clinical LINAC in Volumetric Modulated Arc Therapy

  • Rahman, Mohammad Mahfujur;Kim, Chan Hyeong;Kim, Seonghoon
    • Journal of Radiation Protection and Research
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    • v.44 no.1
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    • pp.43-52
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    • 2019
  • Background: The mid-term performance of clinical linear accelerator (LINAC) during volumetric modulated arc therapy (VMAT) treatment period is not performed in clinical practice and usually replaced with one-time plan quality assurance (QA). In this research we aim to monitor daily reproducibility of VMAT delivery from tracking individual leaf movement error and dosimetric error to evaluate the mid-term quality of the machine used. Materials and Methods: First, multileaf collimator (MLC) information was imported into MATLAB program to determine which of the MLC leaves in the leaf bank had the maximum RMS position error (maxRMS). We estimated where the maximum positional errors (maxPE) of the chosen leaf occur along its path length and tracked its daily variations over the entire treatment period. Secondly, picture information of dosimetric error from portal dosimetry was imported into MATLAB where representative high gamma index region (HGR) was determined as HGR with length of > 1 cm and their centers were daily tracked. Results and Discussion: The maxPEs in the brain and tongue cases were distributed broader than in other cases, but all data were found located within ${\pm}0.5mm$. From first day to last day all of five cases show the similar visual pattern of HGRs and Centers of the longest HGRs remained within ${\pm}1mm$ of that in first day. These findings prove excellent mid-term performance of the LINAC used in VMAT treatments over a full course of treatment. Conclusion: Tracking the daily location changes of leaf movement and dosimetric error can be a good indicator of predicting the daily quality like stability and reproducibility of beam delivering in VMAT treatment.