• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1388-1399
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• 2012

This paper proposes a quality metric based on a No-Reference Bitstream (NR-B) having least computational complexity for the assessment of the human-perceptual quality of H.264 encoded video. The proposed NR-B method performs a modeling of encoding distortion with three bit-stream information (i.e. frame-rate, motion-vector, and quantization-parameter) that can be directly extractable from the encoded bitstream and does not require additional complex processing of final pictures. From performance evaluation using 165 compressed video sequences, the experiment results show that the proposed metric has a higher correlation with subjective quality than is achieved with other comparable methods.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.609-616
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• 2005

The component-based development methodology becomes famous as the reuse technology to improve the high productivity of software development. It is necessary component metrics for component-based systems, because the designed components should be measurable to improve the quality of the software. Therefore this paper propose a coupling metric for component design which is reflected in characteristics of component. This paper suggest a case study and comparative analysis result about conventional metrics to verify the accuracy of our coupling metric. The Uoposed coupling metric measure the quality of components accurately and satisfies necessary conditions of coupling metric suggested by Briand and others.

• Journal of KIISE
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• v.44 no.9
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• pp.992-1004
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• 2017

To assess image quality accurately, an image quality assessment (IQA) metric is required to reflect the human visual system (HVS) properly. In other words, the structure, color, and contrast ratio of the image should be evaluated in consideration of various factors. In addition, as mobile embedded devices such as smartphone become popular, a fast computing speed is important. In this paper, the proposed IQA metric combines color similarity, gradient similarity, and phase similarity synergistically to satisfy the HVS and is designed by using optimized pooling and quantization for fast computation. The proposed IQA metric is compared against existing 13 methods using 4 kinds of evaluation methods. The experimental results show that the proposed IQA metric ranks the first on 3 evaluation methods and the first on the remaining method, next to VSI which is the most remarkable IQA metric. Its computing speed is on average about 20% faster than VSI's. In addition, we find that the proposed IQA metric has a bigger amount of correlation with the HVS than existing IQA metrics.

• Journal of Korean Society for Quality Management
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• v.28 no.1
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• pp.78-94
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• 2000

The ever increasing demands for enhanced competitiveness of engineered products require a "designing-in-quality" strategy that can effectively and efficiently incorporate concepts of uncertainty, quality, and robustness into design. Engineered design optimization approaches that are typically carried out with respect to a single objective become inadequate to address these multiple set of requirements. This paper presents a design metric for a multi-attribute robust design problem with designer′s preferences on the performance accuracy and the performance precision. The use of this design metric as the robust optimal design criterion in multi-stage experimentation and modeling technique is presented. The effectiveness of the overall design procedure and the performance of the proposed design metric are tested with the aid of IC design and the results are discussed.

• International Journal of Quality Innovation
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• v.8 no.1
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• pp.1-14
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• 2007

The Six Sigma and Lean Production methodologies suggest that creating value for customers is the objective of a production process or an organisation. In the production context, "added value" dominates the discussion about the creation of value to customers. However, "added value" is often only defined conceptually or discussed at a strategic level, and the link between added value and customer value has not yet been well conceptualised. Therefore, the purpose of the paper is to develop a methodology to measure added value in order to complement the existing performance measures in Six Sigma and Lean Production by conceptualising the link between customer value and added value. The conceptual link "confirms" that quality, time, and costs are the elements of added value, which are transformed into a metric to express customer value. The implementation of the metric recommends the adoption of Lean (Six) Sigma and Lean Accounting (Activity Based Costing), which thus implies that "leanness" is an important "feature" of added value.

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.59-64
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• 2009

This paper is intended to study how well the routing protocol supplied in wireless mesh networks can evade interference path along the applied routing metric. Wireless mesh networks, unlike existing network techniques, has the characteristics that node movement is less and energy effect is limited. Therefore. this type of network requires path configuring technique to reflect such network characteristics and new routing metric to determine proper path. Routing metric proposed recently is designed to produce link quality accurately, but it configures path not considering the traffic situation of adjacent nodes. Thus. this technique has the problems of reduced transfer rate and delay between terminals occurring due to frequent traffic chaos by the interference of adjacent nodes. Therefore, this paper proposes metric that configures routing path by finding like metric that can transfer data effectively by considering the traffic situation of adjacent nodes. We confirmed through simulation that the proposed routing metric reduces the delay between terminals via the path that evades the traffic interference of adjacent node.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.5
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• pp.255-265
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• 2013

3DTV is expected to be a promising next-generation broadcasting service. On the other hand, the visual discomfort/fatigue problems caused by viewing 3D videos have become an important issue. This paper proposes a perceptual quality assessment metric for a stereoscopic video (SV-PQAM). To model the SV-PQAM, this paper presents the following features: temporal variance, disparity variation in intra-frames, disparity variation in inter-frames and disparity distribution of frame boundary areas, which affect the human perception of depth and visual discomfort for stereoscopic views. The four features were combined into the SV-PQAM, which then becomes a no-reference stereoscopic video quality perception model, as an objective quality assessment metric. The proposed SV-PQAM does not require a depth map but instead uses the disparity information by a simple estimation. The model parameters were estimated based on linear regression from the mean score opinion values obtained from the subjective perception quality assessments. The experimental results showed that the proposed SV-PQAM exhibits high consistency with subjective perception quality assessment results in terms of the Pearson correlation coefficient value of 0.808, and the prediction performance exhibited good consistency with a zero outlier ratio value.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.528-533
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• 2010

Currently the telephone service using Internet grows and the recent introduction of a smart phone is expected to accelerate the trend. In particular, considering the domestic situation that the wireless broadband (WiBro) system deployed over the nation, the telephone service over WiBro can be a solution toward its fast expansion. Unlike telephone service over a conventional telephone network or mobile network, however, internet telephone cannot guarantee it service quality, which can be severer in a wireless environment such as a WiBro network. Therefore, a more strict and systematic management for controlling the quality of internet telephone service over WiBro in a more efficient way. As the first step to establish the management system, this paper proposes a scheme to manage the quality of internet telephone service over WiBro and introduces a software developed for the purpose. The developed software is installed on a user terminal and facilitates efficient service quality management by measuring the quality of internet telephone service over WiBro in terms of VoIP metric, network metric, and wireless metric.

• Journal of Korean Society for Quality Management
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• v.29 no.1
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• pp.47-61
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• 2001

The ever increasing demands for enhanced competitiveness of engineered products require a "designing-in-quality" strategy that can effectively and efficiently incorporate multiple design objectives into design. Robust design can be viewed as a multi-characteristic design problem requiring tradeoffs between mean and variance characteristics. Firstly this paper analyzes the intrinsic preference of the traditional SN ratio on mean and variance, and secondly presents a new design metric for a robust design using concepts from utility theory to accurately capture designer′s intent and preference on mean and variance. The steps to apply the proposed design metric as the robust design criterion in an orthogonal array based engineering experimentation is presented with the aid of a demonstrative case study. The performance of the proposed design metric is tested, and the results are discussed.

• Journal of Korean Society for Quality Management
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• v.44 no.2
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• pp.373-388
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• 2016

Purpose: This paper suggests a hierarchical time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). In place of the conventional RPN(risk priority number), a more reasonable and objective risk metric is proposed under hierarchical failure cause structure considering time delay between a failure mode and its causes. Methods: The structure of failure modes and their corresponding causes are analyzed together with the time gaps between occurrences of causes and failures. Assuming the severity of a failure depends on the length of the delayed time for corrective action, a severity model is developed. Using the expected severity, a risk priority metric is defined. Results: For linear and quadratic types of severity, nice forms of expected severity are derived and a meaningful metric for risk evaluation is defined. Conclusion: The suggested REM(risk evaluation metric) provides a more reasonable and objective risk measure than the conventional RPN for FMEA.