• 음성과학
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• 제6권
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• pp.163-179
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• 1999

For the set up, management and repair of a mobile communication system, continuous estimation of speech quality is required. Speech quality measurement can be conducted by listener's judgement in a subjective test such as MOS (Mean Opinion Score) test. However, this method is laborious, expensive and time-consuming, it is advisable to predict subjective speech quality via objective measures. This paper presents a robust objective speech quality measure, PLP-CMS (Perceptual Linear Predictive-Cepstral Mean Subtraction), which can predict subjective speech quality in mobile communication systems. PLP-CMS has a high correlation with subjective quality owing to PLP (Perceptual Linear Predictive) analysis and shows a robust performance not being influenced by PSTN (Public Switched Telephone Network) channel effects due to CMS (Cepstral Mean Subtraction). To prove the performance of our proposed algorithm, we carried out subjective and objective quality estimation on speech samples which are variously distorted in a real mobile communication system. As a result, we demonstrated that PLP-CMS has a higher correlation with subjective quality than PSQM (Perceptual Speech Quality Measure) and PLP-CD (Perceptual Linear Predictive-Cepstral Distance).

• 한국정보시스템학회지:정보시스템연구
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• 제23권3호
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• pp.47-71
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• 2014

The purpose of the present study is to verify the structural relationship among system quality, information quality, service quality, perceived ease of use, perceived usefulness, satisfaction, intention on continuous use of mobile learning in cyber university. For this study, W cyber university in Korea was chosen to conduct web survey. The subjects were 283 students who participated in W's cyber university courses. A hypothetical model was composed of system quality, information quality, service quality, perceived ease of use and perceived usefulness as exogenous variables, satisfaction and intention on continuous use of mobile learning as endogenous variables. The result of this study through structural equation modeling analysis is as follows: First, information quality only affect satisfaction, Second, perceived ease of use, perceived usefulness and satisfaction significantly affect intention on continuous use of mobile learning. These results imply that information quality should be considered for the design and development of mobile learning contents. Also, perceived ease of use, perceived usefulness and satisfaction is important to enhance intention on continuous use of mobile learning. This study proposes strategies for successful mobile learning in cyber university.

• 디지털융복합연구
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• 제10권11호
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• pp.11-27
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• 2012

본 연구의 목적은 외부 IT감리의 핵심 성공 요인을 제시하는 것이다. 이를 위해, 정보시스템 성공 모형과 서비스 품질 개념을 기반으로 통합 모델을 제시하였다. 연구모형은 외부 감리를 수행한 경험이 있는 국내 공공기관을 표본으로 총 254개의 데이터를 수집하여 분석하였다. 분석결과 서비스 품질 특성 중 응답성, 신뢰성, 유형성은 정보시스템의 구현 프로세스 품질에 유의한 영향을 미치는 것으로 나타났다. 또한 프로세스 품질은 정보시스템 구현 성공(시스템 품질)에 유의한 영향을 미치는 것으로 나타났다.

• 한국IT서비스학회지
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• 제23권2호
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• pp.99-116
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• 2024

Recently, interest in ChatGPT has been increasing. This study investigated the factors influencing the satisfaction of users using ChatGPT service, a chatbot system based on artificial intelligence technology. This paper empirically analyzed causality between the four major factors of service quality, system quality, information quality, and security as independent variables and user satisfaction of ChatGPT as dependent variable. In addition, the mediating effect of reliability between the independent variables and user's satisfaction was analyzed. As a result of this research, except for information quality, among the quality factors, security and reliability had a positive causality with use satisfaction. Reliability played a mediating role between quality factors, security, and user satisfaction. However, among quality factors, the mediating effect of reliability between service quality and user's satisfaction was not significant. In conclusion, in order to increase user satisfaction with new technology-based services, it is important to create trust among users. The research results sought to emphasize the importance of user trust in establishing development and operation strategies for artificial intelligence systems, including ChatGPT.

• 품질경영학회지
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• 제40권3호
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• pp.278-285
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• 2012

Purpose: Weapon systems have the long life cycle unlike the consumer product. Thus, the reliability of weapon system is improved during the life cycle through the steady technical change. In this paper, we deal with the method of evaluating the reliability of weapon system with the field failure data. Methods: Especially, we present how to gather the field failure data and evaluate the reliability through the case of K-series weapon system. To evaluate reliability, the reliability growth model is used and the result is discussed. Results: It is steadily improved the reliability of K-series weapon system deployed from 2000 to 2004. The frequency of the failures that affect the mission is largely reduced and MTBMF(mean time between mission failure) is also improved. Conclusion: We can guess the trend of the reliability of weapon system with the field data through this study. Furthermore, it can be used to improve the reliability and make maintenance policy.

• 품질경영학회지
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• 제43권3호
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• pp.421-438
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• 2015

Purpose: The purpose of this study was to grasp the level of effects innovative features and quality of the appliance system on organizational performance and ultimately analyze the willingness of the IT staff to adopt an appliance system. Methods: The survey was conducted on 350 vendors' clients and partners who currently use an appliance system from March to May 2014. A total of 331 effective questionnaires were collected and analyzed using PASW18 and SmartPLS. Results: The results show that relative advantage, facilitating condition and trialability and quality factors all had an effect on organizational performance expectations. Further, when an appliance system is adopted, it was shown that cost and reliability emphasized by a vendor did not produce any significant effects on organizational performance expectations. Conclusion: This study is significant as it is the first to combine such models as Innovation Diffusion Theory, Information Systems Success Model, and Unified Theory of Acceptance and Use of Technology with a new external variable. In addition, it illustrated how variables affect the adoption of an appliance system such as a new innovation system.

• 한국농공학회지
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• 제42권4호
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• pp.87-95
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• 2000

A vegetation purification system was applied to improve water quality of Masan Reservoir in Korea, which was composed of constructed wetlands in series. Five different kinds of macrophytes were planted in each wetland. The system was operated with the condition of low concentrations and high hydraulic loadings. Removal efficiencies(%) of chemical oxygen demand(COD) , total nitrogen(T-N) and total phosphorus(T-P) in this system were 9.0, 12.8, 20.1% , respectively. and removal rates(g/$m^2$/d) were 1.9(COD), 0.34(T-N) and 0.05(T-P) . Comparing this system with other wetlands operated at low hydraulic loadings, average removal efficiencies were low but removal rates were relatively high. Accordingly, this system could be applied to imporve reservoir water quality, because removal rates are more important than removal efficiencies in case of reservoir water quality improvement . However, the removal efficiencies and rates of this system are less than those of the hydroponic biofilter method which is a kind of a constructed wetland and utilize root zones of emergent macrophytes for trapping pollutants. Therefore, it is recommended that this system should be modified to utilize root zones of emergent macrophytes enough to improve reservoir water quality more efficiently.

• 한국산업보건학회지
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• 제20권4호
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• pp.241-247
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• 2010

Recently, indoor air quality (IAQ) has been one of the major concerns of people. Indoor parking lots are subject to be exposed to high concentrations of air pollutants emitted from vehicles. This study was performed to investigate indoor air quality (IAQ) at indoor parking lots. Sampling sites were selected 5 indoor parking lots. Target indoor air quality parameters include a number of criteria pollutants such PM$_{10}$, CO, CO$_2$, and HCHO. In addition, a variation of IAQ according to ventilation system operating was measured at C site (underground parking lot). In general, all pollutants were maintained below indoor air quality maintenance standards. The indoor air quality at indoor parking lots was affected by the availability of the ventilation facility and their operation frequency. At the underground parking lot (C site) with ventilation system, TVOC concentration according to ventilation system operating were found to be lower operating (488.2 ${\mu}g/m^3$) than non-operating (1,401.2 ${\mu}g/m^3$).

• 품질경영학회지
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• 제35권4호
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• pp.16-25
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• 2007

The purpose of this study is to research and analyze the influence of ISO 9001 QMS(Quality Management System) certification on the employer's financial goal and the employee' satisfaction. In this study, we could find that ISO 9001 QMS certification influenced eight factors which contribute to employee's satisfaction, and the purpose and background of ISO 9001 QMS certification was analyzed to have a good influence on the employee's satisfaction. In the future, the implementation strategy of ISO 9001 QMS needs to be studied to make the employees satisfied more with their duties and to pursue the employer's financial goals at the same time.

• 산업경영시스템학회지
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• 제23권57호
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• pp.63-76
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• 2000

In today's competitive, market-driven world, a company's survival rests in its ability to provide quality performance products accompanied by total customer satisfaction. To satisfy the needs of customers, companies strive for defect free performances. This requires companies establish an integrated quality management system based on ISO 9000, ISO 14000, QS-9000, AS-9000, TL-9000, 100 PPM, and six sigma. This paper suggests that how to integrate implementation of quality certification systems and six sigma is an important approach in the continuous quality improvement, and six sigma efforts have become one of the key success approach. Through the various survey of total quality management system approach, it is intended to provide a chance to benchmark or give a cue on how to conduct the quality management innovation.