• Title/Summary/Keyword: Data quality assessment

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A Study on Measuring the Similarity Among Sampling Sites in Lake Yongdam with Water Quality Data Using Multivariate Techniques (다변량기법을 활용한 용담호 수질측정지점 유사성 연구)

  • Lee, Yosang;Kwon, Sehyug
    • Journal of Environmental Impact Assessment
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    • v.18 no.6
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    • pp.401-409
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    • 2009
  • Multivariate statistical approaches to classify sampling sites with measuring their similarity by water quality data and understand the characteristics of classified clusters have been discussed for the optimal water quality monitering network. For empirical study, data of two years (2005, 2006) at the 9 sampling sites with the combination of 2 depth levels and 7 important variables related to water quality is collected in Yongdam reservoir. The similarity among sampling sites is measured with Euclidean distances of water quality related variables and they are classified by hierarchical clustering method. The clustered sites are discussed with principal component variables in the view of the geographical characteristics of them and reducing the number of measuring sites. Nine sampling sites are clustered as follows; One cluster of 5, 6, and 7 sampling sites shows the characteristic of low water depth and main stream of water. The sites of 2 and 4 are clustered into the same group by characteristics of hydraulics which come from that of main stream. But their changing pattern of water quality looks like different since the site of 2 is near to dam. The sampling sites of 3, 8, and 9 are individually positioned due to the different tributary.

Realtime No-Reference Quality-Assessment Over Packet Video Networks (패킷 비디오 네트워크상의 실시간 무기준법 동영상 화질 평가방법)

  • Sung, Duk-Gu;Kim, Yo-Han;Hana, Jung-Hyun;Shin, Ji-Tae
    • Journal of Broadcast Engineering
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    • v.14 no.4
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    • pp.387-396
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    • 2009
  • No-Reference video-quality assessments are divided into two kinds of metrics based on decoding pixel domain or the bitstream one. Traditional full-/reduced- reference methods have difficulty to be deployed as realtime video transmission because it has problems of additional data, complexity, and assessment accuracy. This paper presents simple and highly accurate no-reference video-quality assessment in realtime video transmission. Our proposed method uses quantization parameter, motion vector, and information of transmission error. To evaluate performance of the proposed algorithm, we perform subjective test of video quality with the ITU-T P.910 Absolute Category Rating(ACR) method and compare our proposed algorithm with the subjective quality assessment method. Experimental results show the proposed quality metric has a high correlation (85%) in terms of subjective quality assessment.

A Note on the Use of Peer Assessment to Improve Pupil's Performance

  • Lee, Kyung-Koo;Mun, Gil-Seong;Ahn, Jeong-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.2
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    • pp.443-450
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    • 2008
  • Peer assessment is the process of assessment of students by other students and one form of innovative assessment. It actively involves students in the assessment process and is generally agreed that such involvement enhances the quality and effectiveness of the learning process, since assessing something and benchmarking process is a powerful aid to mastering it themselves. It is more effective on the hard courses for them to understand. In this article we present a peer assessment technique which was applied to students enrolled in a mathematical statistics course and a historical course. In order to measure the effectiveness of the technique, students had to evaluate their colleagues based on predefined criteria and a comparison is presented between the instructor assessments and the peer assessment.

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Stochastic Estimation of Voltage Sags Based on Voltage Monitoring (전압 모니터링에 기반한 순간전압강하 확률적 추계 방법)

  • Son, Jeongdae;Park, Chang-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.10
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    • pp.1271-1277
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    • 2018
  • This paper deals with a voltage sag assessment based on a voltage monitoring program. The voltage sag performance at a specific site can be evaluated by analyzing voltage monitoring data recorded for a long time period. Although an assessment based on voltage monitoring is an effective way to understand voltage sag performance at a measurement site, the statistical confidence of voltage sag frequency estimation heavily depends on the length of monitoring period and the number of recorded events. Short monitoring period and insufficient recorded data can not provide a reliable assessment result. This paper proposes a compensation assessment method by combining a computer simulation approach for in case that monitoring period and data are not enough for a valid assessment.

Report from a National Cancer Institute (USA) workshop on quality of life assessment in cancer clinical trials

  • Nayfield S.G.;Ganz P.A.;Moinpour C.M.;Cella D.F.;Hailey B.J.
    • 대한예방의학회:학술대회논문집
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    • 1994.02b
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    • pp.324-331
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    • 1994
  • To promote the inclusion of quality of life (QOL) end-points In clinical research on cancer, the National Cancer Institute (USA) sponsored a workshop on QOL assessment In cancer clinical trials In July, 1990. Experts In clinical trials and QOL research formed four working groups to Identify current areas of cancer treatment In which QOL end-points are most Important; to discuss methodologic problems In QOL assessment; to address common problems In Implementing clinical studies with QOL end-points; and to consider statistical Issues In design, Implementation, and data analysis. Recommendations made by the working groups are summarized in this paper.

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No-Reference Image Quality Assessment based on Quality Awareness Feature and Multi-task Training

  • Lai, Lijing;Chu, Jun;Leng, Lu
    • Journal of Multimedia Information System
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    • v.9 no.2
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    • pp.75-86
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    • 2022
  • The existing image quality assessment (IQA) datasets have a small number of samples. Some methods based on transfer learning or data augmentation cannot make good use of image quality-related features. A No Reference (NR)-IQA method based on multi-task training and quality awareness is proposed. First, single or multiple distortion types and levels are imposed on the original image, and different strategies are used to augment different types of distortion datasets. With the idea of weak supervision, we use the Full Reference (FR)-IQA methods to obtain the pseudo-score label of the generated image. Then, we combine the classification information of the distortion type, level, and the information of the image quality score. The ResNet50 network is trained in the pre-train stage on the augmented dataset to obtain more quality-aware pre-training weights. Finally, the fine-tuning stage training is performed on the target IQA dataset using the quality-aware weights to predicate the final prediction score. Various experiments designed on the synthetic distortions and authentic distortions datasets (LIVE, CSIQ, TID2013, LIVEC, KonIQ-10K) prove that the proposed method can utilize the image quality-related features better than the method using only single-task training. The extracted quality-aware features improve the accuracy of the model.

Environmental Impact Assessment and Environmental Monitoring: Monitoring Factors and Organization (환경영향평가와 측정 : 환경처 업무 중심으로)

  • Kang, In-Goo;Chang, Chun-Ki;Han, Eui-Jung;Kim, Myung-Jin
    • Journal of Environmental Impact Assessment
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    • v.3 no.2
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    • pp.69-75
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    • 1994
  • Environmental Impact Assessment is composed of screening, scoping, inventory survey, prediction, assessment, alternative assessment, mitigation measure, and post management. Environmental monitoring data is applied to EIA process such as prediction and post management. It must he collected and managed systematically for effective applying in EIA process. This article explains factors such as air quality, water quality, soil, ocean, odor, noise & vibration, ecosystem, etc. and organizations of environmental monitoring managed by Ministry of Environment.

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A Wavelet-based Yarn Quality Assessment for Fabric Visual Qualities (직물외관을 위한 웨이블릿 기반의 방적사 평가시스템)

  • Kim, Jooyong
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2002.05a
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    • pp.16-19
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    • 2002
  • Random and/or periodic defects occur in all spun yarns. These irregularities can often lead to defects in finished fabric. Yarn evenness tests are used to obtain statistical data about yarn properties, such as CV%, which is useful in comparing several sets of similar data that differ in mean value but may have some commonality in relative variation. Although this statistical data is helpful in determining relative yarn Quality, accurate predictions of how the yarn will appear in fabric form are still difficult to obtain. As an promising alterative, wavelet analysis has been employed to localize yam defect so as to predict the visual qualifies of the fabrics.

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A Wavelet-based Yarn Quality Assessment for Fabric Visual Qualities

  • Kim, Joo-Yong
    • Science of Emotion and Sensibility
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    • v.5 no.3
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    • pp.35-38
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    • 2002
  • Random and/or periodic defects occur in all spun yarns. These irregularities can often lead to defects in finished fabric. Yarn evenness tests are used to obtain statistical data about yarn properties, such as CV%, which is useful in comparing several sets of similar data that differ in mean value but may have some commonality in relative variation. Although this statistical data is helpful in determining relative yam quality, accurate predictions of how the yarn will appear in fabric form are still difficult to obtain. As an promising alterative, wavelet analysis has been employed to localize yarn defect so as to predict the visual qualities of the fabrics.

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Assessment and Validation of the Reliability of Quality Measurement System for Wireless Data Services (무선데이터 서비스 품질 측정 시스템의 신뢰성 검증 및 평가)

  • Choi, Dong-Hwan;Park, Seok-Cheon
    • Journal of Information Technology Services
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    • v.11 no.1
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    • pp.239-246
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    • 2012
  • The user increases around the WiBro and in which the mobile broad band service is the wireless internet base technology HSDPA, that is the cellular phone foundation technique, and moreover the issue about the user effective quality guarantee emerges but the quality control of the wireless network is the incomplete actual condition. Therefore, the reliability verification according to the development of the system for the performance measure for the continued wireless data service and it and evaluation are needed for the quality control. In this paper, the wireless data service quality measurement system was implemented with the design. The same test environment as the existing network performance measurement program was built for the reliability verification of the embodied device for measuring quality and evaluation and the cost performance was performed. It could confirm that design and embodied wireless data service quality measurement system operated accurately in this paper through the quality measure result value analysis.