• 산업기술연구
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• 제31권B호
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• pp.99-105
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• 2011

Recently, smartphones have been widely used in wireless communications which caused severe data overload in cellular networks. Cellular companies consider increasing wireless data capacity in overloaded areas. Determining overloaded areas is mainly made from user reports which are currently collected by calling or simple apps by some active users experiencing overloads. Since the current reporting method is inconvenient and does not contain detail information about the overload conditions, and therefore is used by only some active users, the overloaded areas determined from the reports are not likely to be accurate. Therefore, we need a new reporting method which is convenient enough for even inactive users to willingly report the overload condition and which delivers detail information about the overloads. In this paper, we design and implement a measurement function of smartphone's WCDMA communication quality including overload condition and management system of mobile wireless communication networks about smartphones' communication quality.

• 항공우주시스템공학회지
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• 제3권1호
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• pp.6-11
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• 2009

It is anticipated that quality assurance for the Ka band Communication Payload System(COPS) development program of the communication, Ocean & Meteorological Satellite(COMS) may be a core technical factor to be concerned in order to avoid any failure, and to assure its final performance during the mission lifetime in space. Those can be managed and verified and assessed by performing the Quality Assurance (QA) and risk management which helps to prevent and to reduce the critical fails. This paper introduces the Product Assurance (PA) system and procedures for controlling and monitoring sub-contractors which were participated in Ka band Communication Payload System (COPS) development. Also this paper shows Quality Assurance (QA) procedures and detailed their processes for assured the product performed by local companies from site survey for selecting companies to delivery of their equipment.

• International journal of advanced smart convergence
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• 제10권3호
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• pp.89-96
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• 2021

In various areas of the 4th industry, a big issue is software quality enhancement for stability and reliability of the smart software systems. After revising software promotion law at 2020, we must clearly define requirements and separate design parts and implementation parts of an all public software development contracts. In this study, we need to validate whether the final implementation of software is followed by the original design or not. To do this, we consider the design restoration through software visualization based on reverse engineering. Therefore we propose an UML design extraction and visualization method based on reverse engineering. Based on this, we may validate whether it is implemented according to the original design, and how much visualizes and includes the code the internal complexity for improvement of software quality.

• Journal of information and communication convergence engineering
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• 제19권4호
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• pp.284-289
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• 2021

This study attempted to identify the service satisfaction with the 119 emergency service and the factors that affect it based on the responses of subjects who used the service. Data collection was conducted from February 11 to March 11, 2021, using convenience sampling. A total of 1842 subjects who used emergency medical services using 119 ambulance in 2020 participated. For the collected data, frequency, percentage, mean, and standard deviation were calculated, and t-test, analysis of variance, and multiple regression analysis were performed using SPSS 23.0. Based on these results, to further enhance the satisfaction of users of the 119 emergency service and the quality of emergency medical services, it is important to improve the quality of paramedics through education and systems. In addition, to increase user satisfaction, efficient and systematic communication education is required. The quality of emergency medical services will increase only when communication skills required for explanations and promoting understanding are improved.

• 방송공학회논문지
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• 제14권4호
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• pp.387-396
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• 2009

기존의 무기준 동영상 화질 평가는 디코딩 픽셀 단에서 평가와 전송 에러를 고려한 비트스트림단에서 화질 평가 방법으로 나눌 수 있다. 기존의 방법은 추가 데이터 필요하고 복잡도와 평가 정확도등의 문제가 있어 실제적인 실시간 화질평가에 적용하기에 문제가 많다. 본 연구에서는 실시간 비디오 전송 환경에서 이용될 수 있는 간단하면서도 정확도가 높은 무기준법 화질 평가 방법을 제안한다. 본 논문에서 제안된 무기준법 화질평가 방법은 양자화 파라미터, 전송에러정보, 움직임 벡터정보를 이용한다. 제안된 방법을 검증하기 위해서, ITU-T P.910 ACR(Absolute Category Rating)을 사용하여, 기존의 전체 기준법과 주관적 화질 평가 대비의 상관도를 비교하였는데 제안방법이 85%이상의 상관도를 보여 주었다.

• 한국전자통신학회논문지
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• 제11권3호
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• pp.309-316
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• 2016

최근 이동통신 환경에서 음성 서비스는 VoIP 기술을 이용한 패킷 기반 서비스로 이루어지고 지는 추세에 있다. VoIP 패킷을 전송하기 위해서 필요한 전송 속도를 고려했을 때 현재 LTE 이동통신 시스템이 제공하는 전송 속도는 매우 충분하지만 무선 채널의 특성 상 단말 주변의 전송 환경의 변화나 이동성 등으로 인한 일시적인 서비스 품질의 저하가 발생할 수 있다. 본 논문에서는 이와 같은 실험 환경을 구축하고 주요 전송 관련 파라미터를 변화시키면서 그에 따른 VoIP 서비스의 품질의 변화를 측정하였다. 이를 토대로 향후 VoIP 서비스 제공을 위한 네트워크 요구 사항을 수립하는 것이 가능하다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
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• pp.73-78
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• 1998

Our platform introduced in this paper is based on DAVIC specifications which define high quality multimedia services with some extensions to provide user friendly and uniform interface to its users. We designed and implemented an integrated service platform for high quality interactive multimedia services, swithed digital broadcasting, and Internet services. The integration in terms of a service provider system, a delivery system, and a service user system is taken into account. Our research results in the development of integrated high quality interactive and digital broadcasting multimedia services with web-based common user interface and its experience will be feedback to the field trial service which will be launched from next year.

• 디지털융복합연구
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• 제8권3호
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• pp.155-168
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• 2010

This paper focuses on the construct of relationship quality and the influence of relationship quality on relationship persistence, willingness to recommend. In this paper, we first conceptualize relationship quality from buyer-based perspective. Second, we introduce relationship persistence and willingness to recommend as consequences of relationship quality. A research model is examined with data collected from 267 firms in Gumi. The results indicate that relationship quality can be defined as a construct of trust, satisfaction, coadaptation, communication, and relationship quality has a significant positive impact on relationship persistence, willingness to recommend.

• 품질경영학회지
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• 제30권3호
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• pp.150-167
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• 2002

Normative theory suggests that control systems should be designed to complement management's objectives and strategies. However, few empirical studies have focused on how control systems have been modified to complement new manufacturing techniques, such as zero-defect strategy. The major purpose of this study is to examine the effects of the attributes of quality strategy and control system on performance. The previous studies have subdivided quality strategy into the ECL(economic conformance level) and ZD(zero-defect) strategy. To accomplish the purpose, this study empirically analysed the data based on the questionnaires from manufacturing department personnel of 67 Korean companies. The major results are as follows. The companies that had implemented the ZD strategy and its control system outperformed the companies that had implemented ECL strategy. Also, the ZD strategy differs from ECL strategy in control system, the criteria of performance evaluation and feedback frequence variable. There is no difference in quality performance monitoring and communication variable. From this results, although many companies have strived for continuous improvement of quality, it was restricted in improvement activities that dont's required much investment cost, quality performance monitoring and communication.

• 전기학회논문지P
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• 제56권1호
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• pp.13-18
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• 2007

In this paper, authors deal with an application of power quality monitoring using the Sampled Value which is described in the IEC61850 International Standard for substation communication. Firstly, while Merging Unit is designed as a process level device transmitting sensor data, the practical problems such as time delay compensation and optical fiber communication are issued. Secondly, the Sampled Value message which is proper to a power quality monitoring system is presented. Because the power quality monitoring system requests non time critical service comparing to protection and control applications, the Sampled Value service message structure is introduced to improve efficiency. At last, the power quality monitoring server having various power quality analysis functions is suggested to verify the performance of Merging Unit. With the diverse experiments, it is proved that the process bus distributed solution is flexible and economic for the power quality monitoring.