• 한국신뢰성학회지:신뢰성응용연구
• /
• 제16권4호
• /
• pp.356-363
• /
• 2016

Purpose: The purpose of this study is to propose efficiency of equipment testing the luminance degradation of OLED. Methods: The degradation model of Exponential model and Stretched exponential model is analyzed by goodness of fit test using calculated R-square. The degradation model having the higher R-square is finally selected. Scale parameter and Shape parameter using the selected degradation model is estimated. The activation energy and current density n using peck model among the accelerated model is estimated. the estimated parameters are analyzed by t-test. Results: The results of t-test show that the estimated parameters on chamber and hotplate are equal statistically. we can know the similarity of the luminance degradation rate and degradation pattern on chamber and hotplate. Conclusion: The result of the degradation test on chamber and hotplate is similar. when the accelerated degradation test on the panel of the OLED TV is performed, hotplate is requiring less samples, time and cost than chamber. so the accelerated degradation test on the panel of the OLED TV using the hoplate is efficient of time and cost.

• 품질경영학회지
• /
• 제39권1호
• /
• pp.71-77
• /
• 2011

In the fields of reliability application, the most commonly used test methods for reliability qualification are zero failure tests since they require fewer test samples and less test time compared to other test methods that guarantee the same reliability with a given confidence level. An economic zero failure test plan is developed that minimizes the total cost related to perform a life test to guarantee a specified reliability of a product with a given confidence level and a numerical example is provided to illustrate the use of the proposed test method.

• 한국통신학회논문지
• /
• 제33권9B호
• /
• pp.802-812
• /
• 2008

본 논문에서는 초고속인터넷망에서 멀티미디어 서비스 제공 능력의 시험을 통하여 광대역통합망(BcN: Broadband convergence Network)에서의 서비스 제공 가능성 분석에 활용할 수 있는 초고속인터넷의 QoS 제공모델을 제시하고 품질수준을 검증하였다. 3개의 초고속인터넷 사업자가 제공 중인 $10{\sim}100Mbps$급 서비스를 대상으로 전국적으로 총 46개의 가입자를 선정하여 시험환경을 구축하고, BcN의 핵심서비스인 음성/영상전화, VoD 및 IPTV 서비스에 대한 품질시험을 수행하여 QoS 제공수준 및 품질저하 원인 등을 분석하였다. QoS 분석결과를 기초로 하여 BcN에서 활용이 가능한 고수준의 QoS 제공 모델을 제시하고, 광대역통합연구망(KOREN)에 QoS 시험망을 구축하여 QoS 적용으로 인한 서비스 품질확보 수준을 검증하였다. 연구결과는 국내외 통신 사업자들의 차세대통신망(NGN: Next Generation Network)기반 All-IP망의 구축에 중요한 자료로 활용될 것으로 기대한다.

• 한국통신학회논문지
• /
• 제23권8호
• /
• pp.1915-1925
• /
• 1998

교환 시스템이 고장과 장애를 일으키면 서비스에 치명적인 영향을 미치게 된다. 다시 말해서 시스템을 제어하는 교환 소프트웨어의 역할은 매우 중요하다. 그렇기 때문에 정량적인 소프트웨어의 품질 평가 방법은 더욱 중요하다. 본 논문에서는 기능 블록으로 구성된 교환 소프트웨어를 시험하여 얻어진 각종 고장 데이터를 수집, 분석하고 이를 이용하여 각 버전별, 개발 전과정에 대한 소프트웨어 신뢰도를 평가해보고, 기타 고려할 사항에 대해 논한다. 대표적인 2개의 신뢰도 모형(G-O model, S-Shaped model)을 선택하여 소프트웨어 신뢰도를 비교해 보고 품질 향상을 위한 제반 활동과 소프트웨어 개발 프로젝트에 맞는 소프트웨어 신뢰도 모형을 제시하였다.

• 설비공학논문집
• /
• 제13권1호
• /
• pp.9-17
• /
• 2001

In this study, flow boiling experiments were performed using R-134a on a plain tube bundle. Tests were conducted for the following range of variables; quality from 0.1 to 0.9, mass flux from $8\;kg/m^2s$ to $26\;kg/m^2s$ and heat flux from $10\;kW/m^2s$ to $40\;kW/m^2s$. The heat transfer coefficients were strongly dependent on the heat flux. However, they were almost independent on the mass flux or quality. The data are compared with the modified Chen model, which satisfactorily () predicted the data. Original Chen model, however, did not adequately predict the effect of quality. The reason may be attributed to the flow pattern of the present test, where the bubbly flow prevailed for the entire test range. The heat transfer coefficients of the tube bundle were 6~40% higher than those of the single tube pool boiling.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제17권2호
• /
• pp.83-91
• /
• 2017

Purpose: The purpose of this study is to develop a quality assurance model and to determine appropriate warranty period for a guided missile using its field data. Methods: 10 years of actual firing data is collected from the defense industry company and military. Parametric maximum likelihood estimation for a reliability function is determined with the data. Results: The reliability function estimates average lifetime of the missile. That function shows a user requirement, 80% reliability (lifetime) is come up when 8 years have passed, which is longer than the estimates in the missile's development phase. Conclusion: Quality assurance warranty for a guided missile must be established with actual test data. It is necessary to update and modify the reliability prediction and the warranty period with actual field test data.

• 유통과학연구
• /
• 제22권6호
• /
• pp.33-44
• /
• 2024

Purpose: This study aims to measure how information quality, system quality, security, usefulness, and ease of use of Augmented Reality (VR) and Virtual Reality (AR) influence user satisfaction, motivating intelligent travel technology developers to improve VR/AR quality to meet customer requirements. Research design, data and methodology: This study investigates users interested in travelling in Ho Chi Minh City and Nha Trang City, Vietnam. The research model was implemented using an online questionnaire and face-to-face from 405 valid samples. To evaluate the scale's reliability, the study used the software SPSS 20. Test research hypotheses and evaluate measurement and structural models. This research uses AMOS 20 software. The proposed model is firmly grounded in the Information System Success model (ISS) and the Technology Acceptance Model (TAM), providing a solid theoretical foundation for our research. Results: Results show that consumer perceptions of information quality, system quality, security, usefulness, and ease of use have a positive impact on the perceived quality of VR/AR, thereby influencing tourists' travel intention. Conclusions: The results of this research enrich the theoretical understanding of consumer behaviour toward intelligent technology products in tourism, providing management implications for manufacturers to improve the quality of tourism products and satisfy user requirements in experience before considering choosing a destination.

• 한국수자원학회논문집
• /
• 제31권6호
• /
• pp.709-725
• /
• 1998

도시하천의 유출 및 수질특성을 홍제천 시험유역에서의 관측자료에 의하여 분석하였다. 시험유역의 수질은 건기시차집 관로에 의한 하수의 차단으로 비교적 양호한 수질을 보이는 반면, 이로 인하여 동기의 약 3-4개월동안에는 건천화의 현상을 보였다. 한편, 우기시에는 합류식 하수계통으로부터의 급격한 비점원 오염부하량의 증대를 보였다. 도시유출 및 수질을 해석하는 모형, SWMM, ILLUDAS, STORM, HEC-1 등을 적용하고 그 결과를 비교분석하였다. 또한, 시험유역에 대한 유출·수질상관식을 도출하고 그 적용성을 검토하였다. 검토 모형들은 전반적으로 양호한 적용성을 보였으며, 유출과 수질해석의 양면에서 SWMM이 검토모형중에서 가장 우수한 것으로 판단된다. 또한, 실측자료에 근거한 유출·수질상관 모형을 도출하였으며 우기시의 오탁부하량의 근사산정에 효과적인 것으로 판단되었으나, 유량이 관측 자료의 범위를 벗어나면 그 정확도가 크게 떨어졌다. 이 모형은 대상 유역의 관측자료 확충으로 보완되어 나가야 할 것이다. 한편 현재 실무에서 널리 사용되는 HEC-1도 도시유역에서 경제적으로 활용될 수 있을 것으로 판단된다.

• 한국항만학회지
• /
• 제15권1호
• /
• pp.1-18
• /
• 2001

The purpose of this study is to explore the nature of the relationship between several factors representing perceived port service quality and the adaptability to the marketing strategy of container terminal. An empirical study was carried out to examine not only the determinants of port service quality using PZB's SERVQUAL model but also its implications to the service marketing strategy. The data investigating the determinants of port service quality were collected from 136 managers from shipping companies by the use of questionnaire method. Factor analysis and t-test were carried out to analyze the data. The results of this study were as follows ; First, Shipping companies perceive the port service quality on two the dimensions of personnel and material aspects. Second, Shipping companies put more emphasis on the reliance of port service quality even though the port authority offers good facilities and materials as parts of port shipping quality. Third, There is a significant relationship between the purchase intention and the customer satisfaction. These findings help not only to formulate service marketing strategy based on service quality but also to be a concept tool to enhance port service quality.

• 품질경영학회지
• /
• 제35권3호
• /
• pp.107-117
• /
• 2007

The fatigue has been considered the most failure mode of metal, ceramic, and composite materials. In this paper, numerical experiments to asses the usefulness of two Dixon's methods(small and large samples) and 14 S-N methods on assumptions of lognormal fatigue limit distribution under RFL(Random Fatigue Limit) model are conducted for staircase(or up-and-down) test and compared by MSE(Mean Squared Error) and bias for estimates of mean log-fatigue limit. Also, guidelines for staircase test plans to choose initial stress level and step size are recommended from numerical experiments including sensitivity analyses. In addition, the parametric bootstrap method to construct a confidence interval for the mean of log-fatigue limit by the percentile method using a transition probability matrix of Markov chain is presented and illustrated with an example.