• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.316-320
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• 2009

In this paper, a reference-free perceptual quality metric is proposed for image assessment. It measures the amount of overall blockiness and blurring in the image. And edge-oriented artifacts, such as ringing, mosaic and staircase noise are also considered. In order to give a single quality score, the individual artifact scores are adaptively combined according to the difference between the edge-oriented artifacts and other artifacts. The quality score obtained by the proposed algorithm shows strong correlation with the MOS values by VQEG.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.5_6
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• pp.288-296
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• 2004

This paper proposes a new mesh simplification algorithm using differential error metric. Many simplification algorithms make use of a distance error metric, but it is hard to measure an accurate geometric error for the high-curvature region even though it has a small distance error measured in distance error metric. This paper proposes a new differential error metric that results in unifying a distance metric and its first and second order differentials, which become tangent vector and curvature metric. Since discrete surfaces may be considered as piecewise linear approximation of unknown smooth surfaces, theses differentials can be estimated and we can construct new concept of differential error metric for discrete surfaces with them. For our simplification algorithm based on iterative edge collapses, this differential error metric can assign the new vertex position maintaining the geometry of an original appearance. In this paper, we clearly show that our simplified results have better quality and smaller geometry error than others.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.219-227
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• 2017

Network access control should be able to effectively block security threats to the IT infrastructure, such as unauthorized access of unauthorized users and terminals, and illegal access of employees to internal servers. From this perspective, it is necessary to build metrics based on relevant standards to ensure that security is being met. Therefore, it is necessary to organize the method for security evaluation of NAC according to the related standards. Therefore, this study builds a model that combines the security evaluation part of ISO / IEC 15408 (CC: Common Criteria) and ISO 25000 series to develop security metric of network access control system. For this purpose, we analyzed the quality requirements of the network access control system and developed the convergence evaluation metric for security of the two international standards. It can be applied to standardization of evaluation method for network access control system in the future by constructing evaluation model of security quality level of network access control system.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.303-311
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• 2017

As new information technology emerges, companies are introducing an Enterprise Security Management system to cope with new security threats, reducing redundant investments and waste of resources and counteracting security threats. Therefore, it is necessary to construct a security evaluation metric based on related standards to demonstrate that the Enterprise Security Management(ESM) System meets security. Therefore, in order to construct a metric for evaluating the security of the ESM, this study analyzed the security quality related requirements of the ESM and constructed a metric for measuring the degree of satisfaction. This metric provides synergies through the unification of security assessments that comply with ISO/IEC 15408 and ISO/IEC 25000 standards. It is expected that the evaluation model of the security quality level of ESM will be established and the evaluation method of ESM will be standardized in the future.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.179-187
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• 2008

In this paper, we proposed the qualify metric based on SVC and the subjective quality. The proposed quality metric is for a general purpose. It means we can use it for any video sequences regardless of its temporal and spatial characteristics. The Quality of Service(QoS) is one of the important issues in heterogeneous environment which has diverse restrictions such as limited network bandwidth and limited display resolution. Scalable Video Coding(SVC) is the efficient video coding skill in heterogeneous environment. Because SVC can be adapted to various quality bitstreams using three scalabilities(spatial, temporal, and SNR) from one bitstream which has full scalability. To maximize the QoS in this environment, we should consider the subjective quality which is the viewer response. And also we should consider temporal and spatial characteristics of video sequence because the subjective quality is affected by temporal and spatial characteristics of video sequence. To verify the efficiency of the proposed method, we perform subjective assessments. The experimental results show that the proposed method has high correlation with subjective quality. The proposed method can be a decision tool of SVC birstream extraction.

• Journal of Internet Computing and Services
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• v.22 no.2
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• pp.51-58
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• 2021

Three degrees of freedom plus(3DoF+) and six degrees of freedom(6DoF) system, which supports a user's movements in graphical and natural scene-based virtual reality, requires multiple high-quality and high-resolution videos to provide immersive media. Previous video quality assessment methods are not appropriate for the 3DoF+ and 6DoF system assessment because different types of artifacts occur in these systems which are not shown in the traditional video compression. This paper provides the performance assessments of several quality assessment methods in 3DoF+ system. Furthermore, this paper presents a super metric, which combines multiple quality assessment methods, thereby it showed a higher correlation coefficient with the subjective quality assessment than the previous methods. Experimental results on 3DoF+ immersive video showed 0.4513 gain on correlation coefficient with subjective quality assessment compared to that of peak signal-to-noise ratio(PSNR).

• KIISE Transactions on Computing Practices
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• v.24 no.1
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• pp.46-52
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• 2018

Software metrics as a way to evaluate software play a significant role in reducing software development costs and improving quality. However, the emergence of various software metrics creates the problem that the user must select the correct metric. Various strategies have been studied to solve this problem. However, existing studies still have difficulties in selecting metrics by requiring high user interventions. Therefore, in this paper, we propose a method that helps to select the right metric and the metric tools by using their various characteristics as selection criteria, instead of using weighted expressions to minimize user intervention.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.134-143
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• 2010

This paper proposes a framework for classifying metric-based software quality prediction models, especially case of software criticality, into four types. Models are classified along two vectors: input metric forms and the necessity of past project data. Each type has its own characteristics and its strength and weakness are compared with those of other types using newly defined criteria. Through this qualitative evaluation each organization can choose a proper model to suit its environment. My earlier studies of criticality prediction model implemented specific models in each type and evaluated their prediction performances. In this paper I analyze the experimental results and show that the characteristics of a model type is the another key of successful model selection.

• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.543-562
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• 2014

Purpose: The purpose of this study is to suggest a modified approach that compensates some shortcomings of RPN with relevant strength of ASIL for Safety System and suggests systematic and logical approach for FMEA. Methods: By comparing the objectives, determination procedures, and key conceptual differences of RPN and ASIL, a refined method of risk evaluation and a new risk metric are devised. Results: While the traditional FMEA provides only rough evaluation of relative risk for each failure, the proposed method compensates its shortcomings with relevant strength of ASIL and provides a more logical and practical procedure of risk evaluation. Conclusion: The new metric RPM provides not only a comparative priority rank but also the degree of physical seriousness. Besides, it may have even more benefits for various applications if the severity can be expressed as mone tary amount of losses.

• The Transactions of the Korea Information Processing Society
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• v.2 no.2
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• pp.176-184
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• 1995

The software reuse is a prospective way to improve software productivity and quality but not applied very well in practice, because there is no quantitative metric for software quality. In this paper we proposed the quantification of the reuse of software that we can measure the possibility of the reuse by applying the reuse assessment metric to the module after the extraction of a module from existing software. For measuring the module that can be reused, we divided the factors of quality by the generality, simplicity, maintainability and modularity, and identified and measured the module by the factors and finally decided the possibility of the software reuse. The advantage of the proposed metric is that we can find the inappropriate reuse of module exactly at the beginning by measuring quantitatively the module to be reused.