• 방송공학회논문지
• /
• 제20권2호
• /
• pp.204-214
• /
• 2015

업샘플링 깊이맵은 깊이 카메라로부터 획득된 깊이맵의 공간 해상도를 증가시키는 방법이다. 깊이맵의 성능은 입체영상, 멀티뷰의 3D 입체감과 밀접한 관계가 있다. PSNR 등의 객관적 메트릭으로 깊이맵의 업샘플링 성능을 평가하고, 생성된 입체영상은 주관적 평가를 통해서 입체감 및 시각적 피로도를 조사한다. 후자의 주관적 평가는 인적 물적 자원을 필요로 하는 반면에, 전자의 객관적 메트릭은 수학적 표현으로 정량적 수치값을 알려준다. 따라서 주관적 평가와 높은 상관관계를 가지는 객관적 메트릭이 주관적 평가를 대체할 수 있다면 많이 시간을 필요로 하는 주관적 평가가 불필요하다. 이를 위해 본 논문에서는 다양한 객관적 메트릭과 3D 주관적 평가 사이의 관계를 조사한 후에, 이용한 메트릭에 기반한 주관평가와 상관관계가 높은 객관적 메트릭을 제안한다. 업샘플링된 깊이맵의 성능을 측정하기 위해 다양한 참조영상 및 무참조영상 평가 메트릭들을 이용하였다. 주관적 평가는 DSCQS 입체영상 테스트로 수행되었다. 세 종류의 상관관계의 활용 및 분석을 통해서, SSIM과 Edge-PSNR이 주관적 평가를 대체할 수 있는 적합한 객관적 메트릭임을 실험을 통해서 검증하였다.

• 품질경영학회지
• /
• 제47권2호
• /
• pp.271-281
• /
• 2019

Purpose: The purpose of this study is to suggest a more efficient distance measure taking into account the relationship between categorical variables for categorical data cluster analysis. Methods: In this study, the association-based dissimilarity was employed to calculate the distance between two categorical data observations and the distance obtained from the association-based dissimilarity was applied to the PAM cluster algorithms to verify its effectiveness. The strength of association between two different categorical variables can be calculated using a mixture of dissimilarities between the conditional probability distributions of other categorical variables, given these two categorical values. In particular, this method is suitable for datasets whose categorical variables are highly correlated. Results: The simulation results using several real life data showed that the proposed distance which considered relationships among the categorical variables generally yielded better clustering performance than the Hamming distance. In addition, as the number of correlated variables was increasing, the difference in the performance of the two clustering methods based on different distance measures became statistically more significant. Conclusion: This study revealed that the adoption of the relationship between categorical variables using our proposed method positively affected the results of cluster analysis.

• 방송공학회논문지
• /
• 제13권4호
• /
• pp.440-451
• /
• 2008

최근 IP 기반의 멀티미디어 서비스가 증가하면서 IPTV에 대한 수요가 급증할 것으로 예상되고 있다. IPTV는 케이블을 이용하는 기존의 TV와 달리 IP 네트워크 기반의 다양한 서비스 제공이 가능하다. 그러나 IPTV 서비스 품질은 패킷 손실, 지터와 같은 네트워크 열화에 크게 영향을 받기 때문에 언제나 안정된 서비스를 보장하기가 힘들다. 본 논문에서는 다양한 영상 열화에 대하여 주관적 평가를 반영한 IPTV 서비스 품질측정 방안을 도출한다. 이를 위하여 시청자에게 인지적으로 영향을 줄 수 있는 열화 항목을 선정하였으며 선정된 각 열화 항목에 대하여 측정 메트릭을 제안하였다. 각 열화 항목에 대하여 MOS(Mean Opinion Score) 기반의 주관적 평가를 수행하였으며 제안한 메트릭의 측정 결과를 주관적 평가에 사상시켜 주관적 인지 상태를 고려하는 항목별 객관적 품질측정 기준을 도출한다. 다양한 영상에 대한 실험을 통해 개발된 품질측정 메트릭이 주관적 측면을 잘 반영하고 있음을 확인할 수 있다.

• 융합보안논문지
• /
• 제3권1호
• /
• pp.85-94
• /
• 2003

소프트웨어 형상관리 공정은 형상항목의 정확성과 완전성을 보장하고 형상을 관리하는 공정으로 본 논문에서는 형상관리 공정에 대한 구체적인 활동들에 대하여 ISO/IEC 12207과 ISO/IEC 15846을 비교한다. 또한 최근 소프트웨어 프로세스 심사모델로서 널리 알려진 ISO/IEC 15504와 CMM 및 CMMI에서의 형상관리 공정에 대한 활동 비교 및 분석을 통하여 성숙수준을 예측할 수 있는 절차와 메트릭스를 제시하여 정량적인 측정이 가능하도록 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권8호
• /
• pp.1913-1925
• /
• 2012

In order to efficiently utilize limited radio resources, resource allocation schemes in OFDMA-based wireless networks have gained intensive attention recently. Instead of improving the throughput performance, the utility is adopted as the metric for resource allocation, which provides reasonable methods to build up the relationship between user experience and various quality-of-service (QoS) metrics. After formulating the optimization problem by using a weighted bipartite graph, a modified bipartite matching method is proposed to find a suboptimal solution for the resource allocation problem in OFDMA-based wireless systems with feasible computational complexity. Finally, simulation results are presented to validate the effectiveness of the proposed method.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 추계학술대회논문집
• /
• pp.636-640
• /
• 2006

In this study, metrics for evaluation of heavy-weight impact noise were investigated. Heavy-weight impact noises generated by impact ball were recorded in real apartments using binaural microphone. Those sounds were classified into three groups according to frequency characteristics in order to control aspects which affect subjective responses to heavy-weight impact noise. Sound sources for auditory experiment were selected based on the classification result. Then auditory experiments were conducted to investigate the relationship between level indices and subjective responses. The results showed that $L_{Aeq},\;L_{Amax}$ and $LL_z$ as well as $L_{iFmax,AW}$ were highly correlated with subjective response. Therefore, $L_{Aeq}$ and $L_{Amax}$ can be used as metrics for evaluation of heavy-weight impact noise. In further studies, it is needed to verify classification of heavy-weight impact noise generated by bang machine and impact ball.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 추계학술대회논문집
• /
• pp.273-278
• /
• 2002

Booming sound is one of the most important interior sound of a passenger car. The conventional booming noise research was focused on the reduction of the A-weighted sound pressure level. However A-weighted sound pressure level can not give the whole story about the booming sound of a passenger car. In this paper, we employed sound metric which is the subjective parameter used in psycoacoustics. According to recent research results, the relation between sound metrics and subjective evaluation is very complex and has nonlinear characteristics. In order to estimate this nonlinear relationship, artificial neural network theory has been applied to derivation of sound quality index for booming sound of a passenger car.

• 소성∙가공
• /
• 제10권6호
• /
• pp.493-499
• /
• 2001

An optimal robust design methodology has been developed to minimize warpage in injection-molded pats. The response surface methodology was applied to obtain a functional relationship between design variables and warpage value, and the modified complex method was used as an optimization tool to search for an optimal design solution over prescribed design region. To attain robustness against process variations, Taguchi's SN ratio was introduced as the design metric. The proposed optimal design procedure was applied to an actual part, the Guide-ASF model of a fax machine, and the usefulness of the methodology was shown through the CAE simulation using a commercial injection molding software package.

• 산업경영시스템학회지
• /
• 제32권1호
• /
• pp.20-25
• /
• 2009

Mahalanobis Taguchi System (MTS) is a pattern information technology, which has been used in different diagnostic applications to make quantitative decisions by constructing a multivariate measurement scale using data analytic methods without any assumption regarding statistical distribution. The MTS performs Taguchi's fractional factorial design based on the Mahahlanobis Distance (MS) as a performance metric. In this work, MTS is used for analyzing Wisconsin Breast Cancer data which has ten attributes. Ten different tests are conducted for the data to determine if the patient has cancer or not. Also, MTS is used for reducing the number of test to define the relationship between each attribute and diagnosis result. The accuracy of diagnosis is compare with two different previous research.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 1996년도 10월 학술대회지
• /
• pp.206-206
• /
• 1996

Previous studies of American English(e.g. Sussman 1991, 1993, 1994) CVC coarticulation with initial consonants representing the labial, alveolar, and velar showed a linear relationship that fits to data points formed by plotting onsets of F2 transition along the y-axis and their corresponding midvowel points along the x-axis. The present study extends the locus equation metric to include the following places of articulation:uvular, pharyngeal, laryngeal, and emphatics. The question of interest is to determine if locus equation could serve as phonetic descriptor for the place of articulation in Arabic. Five male native speakers of Colloquial Egyptian Arabic(CEA) read a list of 204 CVC and CVCC words, containing eight different places of articulation and eight vowels. Average of formant patterns(Fl,F2,F3) onsets, midpoints, and offsets were calculated, using wide band spectrograms obtained by means of the kay spectrograph model(7029), and plotted as locus equations. A summary of the acoustic properties of the place of articulation of CEA will be presented in the frames of bVC and CVb. Strong linear regression relationships were found for every place of articulation.