• 품질경영학회지
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• 제31권4호
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• pp.239-246
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• 2003

Dynamic robust design has been regarded as the most powerful design methodology for improving product quality, Dynamic SN ratio adopted in dynamic robust design combines two major quality attributes, the variability around the linear function and the slope of the linear function, into a single design metric. The principal shortcoming associated with the dynamic SN ratio is that the metric is independent of designer's preferences for the quality attributes due to priori sets of attribute tradeoff values inherent in it. Therefore, a more rigorous preference­based design metric to accurately capture designer's intent and preference is needed. A new design metric that can be used in dynamic robust design is proposed. The effectiveness of the proposed design metric is examined with the aid of a demonstrative case study and the results are discussed.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.66-73
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• 2010

Vehicles experience the impact due to harsh road conditions. Contact with a barrier on a road induces vehicles to vibrate, which brings about an impact sound. The attenuation of the impact sound is an important issue since passengers may complain about the impact noise. However, the perfect removal of impact noise is not possible as most of impact noise is caused by external conditions. It is thus necessary to make vehicles to possess more desirable sound quality characteristic of impact sound. More research is needed on objective attributes of impact sound; it is not a simple matter since impact noise is transient in nature and has a high level of sound at an instantaneous moment. A new objective attribute of impact noise is designed by using wavelet transform. Wavelet transform is appropriate for the analysis of transient signals such as impact noise. The usefulness of new objective attribute, which is a sound metric, is examined by comparison with the mean subjective rating for real impact noise of passenger cars. The new sound metric has better correlation with the mean subjective rating than already existing sound metrics

• 대한인간공학회지
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• 제31권1호
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• pp.63-76
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• 2012

Objective: The main objective of this study is to propose a user-centered assessment metric for ubiquitous services. Background: As the ubiquitous era took off, the interactions between ubiquitous services and users have come to take an important position. It is essential to conceptualize a new assessment model that considers human-system interaction capability with a user-centered design perspective. Method: The evaluation model for the interactivity of ubiquitous service was approached from the concept of usability and inter-personality of services. As a validation study, suggested assessment metric was utilized to evaluate the u-Home service. Priority weighting of each assessment metric was derived using the quantification type-I analysis. Results: To evaluate interactivity, this study suggested a quantitative metric for user testing performed after classifying the interactivity characteristics to contextualization; ubiquity; user experience; and service capability. Conclusion: This study suggest the metric for the ubiquitous service that are experienced in real life, and introduced the concept of ubiquitous service interactivity. Application: The suggested evaluation metric can be used to evaluate interactivity level of ubiquitous service and identify the potential problem and usability requirements at the early stage of service development.

• 품질경영학회지
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• 제28권1호
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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.

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.141-149
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• 2015

In this study, there is an investigation about the sound quality of automotive horn that attached to luxury sedans. In order to define a questionnaire of horn sound quality the factor analysis is conducted. Ten automotive horns are selected for this research and ten passenger cars(nine is luxury sedan and one economy class car). Luxury is used for the questionnaire as an attribute for the sound quality of car horn. The interior noises for ten test cars are recorded and used for the subjective analysis of car horn sound. In the paper, new sound metric for the car horn sound is presented. The new sound metric is used for the objective sound index for the prediction of subjective sound quality of car horn.

• 한국기계가공학회지
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• 제15권1호
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• pp.95-102
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• 2016

Wrinkle, spring-back, and fracture are major defects frequently found in the sheet metal forming process, and the reduction of such defects is difficult as they are affected by uncontrollable factors, such as variations in properties of the incoming material and process parameters. Without any countermeasures against these issues, attempts to reduce defects through optimal design methods often lead to failure. In this research, a new multi-attribute robust design methodology, based on the Mahalanobis Taguchi System (MTS), is presented for reducing the possibilities of wrinkle, spring-back, and fracture. MTS performs experimentation, based on the orthogonal array under various noise conditions, uses the SN ratio of the Mahalanobis distance as a performance metric. The proposed method is illustrated through a robust design of the sheet metal forming process of a cross member of automotive body.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2021년도 하계학술대회
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• pp.105-108
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• 2021

Generative adversarial networks (GANs) have reached a great result at creating the synthesis image, especially in the face generation task. Unlike other deep learning tasks, the input of GANs is usually the random vector sampled by a probability distribution, which leads to unstable training and unpredictable output. One way to solve those problems is to employ the label condition in both the generator and discriminator. CelebA and FFHQ are the two most famous datasets for face image generation. While CelebA contains attribute annotations for more than 200,000 images, FFHQ does not have attribute annotations. Thus, in this work, we introduce a method to learn the attributes from CelebA then predict both soft and hard labels for FFHQ. The evaluated result from our model achieves 0.7611 points of the metric is the area under the receiver operating characteristic curve.

• Journal of Computing Science and Engineering
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• 제5권4호
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• pp.294-304
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• 2011

Enhancing continuous queries over data streams with temporal functions and predicates enriches the expressive power of those queries. While traditional continuous queries retrieve only the values of attributes, temporal continuous queries retrieve the valid time intervals of those values as well. Correctly evaluating such queries requires the coalescing of adjacent timestamps for value-equivalent tuples prior to evaluating temporal functions and predicates. For many stream applications, the available computing resources may be too limited to produce exact query results. These limitations are commonly addressed through load shedding and produce approximated query results. There have been many load shedding mechanisms proposed so far, but for temporal continuous queries, the presence of coalescing makes theses existing methods unsuitable. In this paper, we propose a new accuracy metric and load shedding algorithm that are suitable for temporal query processing when memory is insufficient. The accuracy metric uses a combination of the Jaccard coefficient to measure the accuracy of attribute values and $\mathcal{PQI}$ interval orders to measure the accuracy of the valid time intervals in the approximate query result. The algorithm employs a greedy strategy combining two objectives reflecting the two accuracy metrics (i.e., value and interval). In the performance study, the proposed greedy algorithm outperforms a conventional random load shedding algorithm by up to an order of magnitude in its achieved accuracy.

• 한국기계가공학회지
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• 제13권2호
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• pp.55-63
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• 2014

Fractures and wrinkles are two major defects frequently found in the sheet metal forming process. The process has several noise factors that cannot be ignored when determining the optimal process conditions. Therefore, without any countermeasures against noise, attempts to reduce defects through optimal design methods have often led to failure. In this study, a new and robust design methodology that can reduce the possibility of formation of fractures and wrinkles is presented using decision-making theory. A two-attribute value function is presented to form the design metric for the sheet metal forming process. A modified complex method is adopted to isolate the optimal robust design variables. One of the major limitations of the traditional robust design methodology, which is based on an orthogonal array experiment, is that the values of the optimal design variables have to coincide with one of the experimental levels. As this restriction is eliminated in the complex method, a better solution can be expected. The procedure of the proposed method is illustrated through a robust design of the sheet metal forming process of a side member of an automobile body.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권4호
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• pp.342-358
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• 2007

유비쿼터스 컴퓨팅 시스템(Ubiquitous Computing System, UCS)은 언제 어디서나 장소에 구애를 받지 않고 사용자가 컴퓨터 네트워크를 이용하여 서비스를 얻을 수 있는 시스템이다. 유비쿼터스 컴퓨팅 시스템은 개인화된 시스템으로써, 다른 시스템과 상호운영이 되는 시스템이다. 이러한 유비쿼터스 컴퓨팅 시스템은 우리 생활에 생산과 소비, 정치, 경제, 사회, 문화, 전 분야에 걸쳐 많은 변화를 가져올 것이다. 따라서 본 논문에서는 이러한 유비쿼터스 컴퓨팅 시스템을 평가하기 위하여 ISO/IEC 9126을 기반으로 체계적인 품질모델을 제안한다. 그러므로, 유비쿼터스 컴퓨팅 시스템의 품질이 좋아야 사용자에게 제공하는 서비스가 좋기 때문이다. 또한 본 논문에서는 유비쿼터스 컴퓨팅 시스템의 중요한 특징들을 식별하고, 식별된 특정을 기반으로 하여 품질속성(Quality Attribute)을 도출한다. 이렇게 도출된 품질속성을 기반으로 하여 메트릭을 정의하고, 유비쿼터스 컴퓨팅 품질모델(Ubiquitous Computing Quality Model, UCQM)을 모델링 하여 유비쿼터스 컴퓨팅 시스템의 전반적인 환경과 중요한 특정을 평가한다.