• International journal of advanced smart convergence
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• 제9권2호
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• pp.68-75
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• 2020

Non-orthogonal multiple access (NOMA) has gained the significant attention in the fifth generation (5G) mobile communication, which enables the advanced smart convergence of the artificial intelligence (AI), the internet of things (IoT), and many of the state-of-the-art technologies. Recently, correlated superposition coding (SC) has been proposed in NOMA, to achieve the near-perfect successive interference cancellation (SIC) bit-error rate (BER) performance for the stronger channel users, and to mitigate the severe BER performance degradation for the weaker channel users. In the correlated SC NOMA scheme, the stronger channel user BER performance is even better than the perfect SIC BER performance, for some range of the power allocation factor. However, such excessively good BER performance is not good for the user-fairness, i.e., the more power to the weaker channel user and the less power to the stronger channel user, because the excessively good BER performance of the stronger channel user results in the worse BER performance of the weaker channel user. Therefore, in this paper, we propose the power splitting to establish the user-fairness between both users. First, we derive a closed-form expression for the power splitting factor. Then it is shown that in terms of BER performance, the user-fairness is established between the two users. In result, the power splitting scheme could be considered in correlated SC NOMA for the user-fairness.

• Asia pacific journal of information systems
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• 제14권1호
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• pp.101-123
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• 2004

User satisfaction has been widely used by information system(IS) researchers as the most appropriate surrogate variable for the systems success since Bailey and Pearson(1983) provided their user satisfaction measurement. Because user satisfaction is a perceived performance measure by users, not a real or objective measure for systems success, however, perceived user satisfaction by users may not be exactly identical with the real systems performance. In this regard, if the user's ultimately perceived satisfaction is different from the real systems performance, we need to investigate why these two measures are different and which factors may cause the difference. From the perspective of disconfirmation of user expecations, this study examined why user satisfaction and real systems performance may not be identical each other. Expectaion-disconfirmation theory which has had a central role in marketing in explaining the effects of expectation and disconfirmation on consumer satisfaction was similarly adopted in this study to explain the role of expectation and disconfirmation in user satisfaction in the IS environment. Based on the expectation-disconfirmation theory, the current study developed a research model to examine the effects of expectation, system performance, and disconfirmation on user satisfaction in particular. Six research hypotheses derived from the research model were empirically tested using the partial least squares(PLS) method. The results of the statistical analysis indicate that the effects of system performance and disconfirmation were fairly strong on user satisfaction, while the user's expectation has shown insignificant influences on user satisfaction.

• 한국지리정보학회지
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• 제1권1호
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• pp.70-85
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• 1998

본 연구는 사용자 특성 중 조직에서 통제 가능한 요인인 사용자의 태도 및 교육훈련이 정보시스템의 실행 성과에 미치는 영향을 검증하기 위한 것이다. 이를 위해 본 연구에서는 최근 신정보시스템으로 전환한 D사의 사용자를 대상으로 설문조사를 실시하여 다음과 같은 결과를 얻었다. 첫째, 사용자 태도와 교육훈련은 각각 독립적으로 정보시스템의 실행 성과에 영향을 미치는 것으로 나타났다. 둘째, 사용자 태도와 교육훈련이 결합한 상호작용 효과는 시스템 사용도에는 유의한 효과를 미쳤지만, 사용자 만족도에는 유의한 효과를 미치지 못한 것으로 나타났다. 이러한 연구 결과에 비추어 볼 때, 조직에서 정보시스템의 실행 성과를 높이기 위해서는 사용자 태도를 호의적으로 변화시키고, 사용자에 대한 교육훈련을 많이 시켜야 하며, 특히 사용자에 대한 교육훈련은 차별화하여 실시하여야 한다는 것이다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1998년도 추계학술대회 논문집
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• pp.28-31
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• 1998

This paper describes the differences of the information system's success factors to improve the end-user's performance according to the job characteristics. A modified model of DeLone and McLean's IS success model is proposed with the two added variables of the top management concern and the IS department support. The model is validated using data collected from a field study of 3872 users on 3 Korean companies. ANOVA, correlation analysis, and stepwise regression are used to test research hypotheses. The results of the study indicate the following implications. First the top management concern and the IS department support have the significant relation with the system usage and the user satisfaction. Second, the system quality has an influence on the user satisfaction more than on the system usage. And the information quality has an influence on the system usage more than on the user satisfaction. Third, the system usage has more relations to the user's performance in the logistics function and R&D function. The user satisfaction has more relations to the user's performance in the sales and the A/S function. Therefore information system strategy to increase the user's performance must be differentiated according to job characteristics.

• 한국IT서비스학회지
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• 제8권3호
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• pp.111-134
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• 2009

We are living it what is referred to as the Digital Era; a time in which communication through the computer medium has deeply infiltrated our everyday lives and is now equivalent to face-to-face communication. In other words, e-communication is the core factor of knowledge sharing, for not only individuals but also for corporations, and its efficiency has increased gradually. At this time, studies on the factors affecting the outsourcing performance of e-communication channel services are gaining importance. Therefore, the purpose of this study is to empirically analyze the effects of the system, information, and service quality on the user satisfaction and user trust of e-communication channel outsourcing, as well as the effects of user satisfaction and user trust on the outsourcing performance of both individuals and organizations. In the results of the empirical study, the system, Information, and service quality appear to have a significant effect on both user satisfaction and user trust. In addition, user satisfaction and user trust appear to also have a significant effect on the outsourcing performance of both Individuals and organizations.

• Journal of Nutrition and Health
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• 제38권2호
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• pp.180-189
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• 2005

The purposes of this study were 1) to analyze the effect of the ERP quality (system quality, information quality, service quality) on the performance (end user satisfaction, user's performance, system utilization) of business, 2) to conduct the causal-effect analysis between outcome variables (user's satisfaction, user's performance, system utilization) of ERP in the contract foodservice management company. The questionnaires were distributed to 260 end users (dietitians, foodservice management managers) in charge of managing the institutional foodservice such as the office (government agencies, factories), schools (universities, middle and high school) and hospitals which were managed by contract foodservice management company 'C' in Seoul and Kyunggi. The surveys were performed from July 26, 2004 to July 30. 2004. Two hundred and fifty (250) questionnaires were responded (response rate: 96.2%). The statistical analysis was conducted using SPSS Win (11.5). And the descriptive analysis, factor analysis, reliability test, pearson correlation, simple and multiple regression analysis were performed. The results showed that among the 3 factors (system quality, information quality, service quality), the system quality and information quality were proved to have an effect on the user's satisfaction and user's performance significantly (p < .05). The influence of ERP quality (system quality, information quality, service quality) on system utilization were testified to be statistically significant (p < .05). The user's performance were affected significantly by system utilization (p < 0.001) and end user's satisfaction (p < 0.001). As a conclusion, to improve user satisfaction, which is the ultimate performance variable of an ERP system, high quality of an ERP system is the pre-requisite. And the user satisfaction and performance of business would be higher with the better quality ERP system. When constructing ERP system for the contract foodservice management company, we should improve system utilization and user satisfaction altogether so that user's performance could be ultimately enhanced and we should make efforts to enhance the quality level of ERP. (Korean J Nutrition 38(2): 180～189, 2005)

• 경영과학
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• 제21권2호
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• pp.111-122
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• 2004

Measuring performance of corporate information system has become one of the core issues in that development of the information system requires substantial amount of investments and the system works as a crucial leverage to enhance competitive edge. Most of the previous researches for performance of the information system have narrow and limited focus on such as the effect of user satisfaction and productivity. This paper suggests a model to measures the comprehensive performance which is classified as user scope (user involvement and satisfaction), operational scope (task productivity, task innovation, customer satisfaction, management control) and efficiency scope (financial performance), and to represent the relationship among the scopes by the path analysis model. Followings are conclusions from statistical hypothesis test of the model: (i) user involvement through user satisfaction has positive effect on all the performances in the operational scope, (ii) task innovation and customer satisfaction in the operational scope has statistically significant impact on financial performance but task productivity and management control do not. This conclusion indicates that task productivity and management control has the long term effect in nature, and evaluation of the information system has managerial implication when it Is measured in comprehensive performance which includes internal operational performances as well as financial performance.

• International journal of advanced smart convergence
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• 제11권1호
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• pp.36-41
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• 2022

Recently, to improve the performance of the strongest channel gain user in non-orthogonal multiple access (NOMA) with a non-uniform source and symmetric superposition coding (SSC), a novel bit-to-symbol (BTS) mapping have been proposed. However, only the performance of the user with the stronger channel gain was analyzed. Thus, we compare the bit-error rate (BER) of the new BTS scheme with that of uniform sources, especially for the user with weakest channel gain. First, we show that the performance of the novel BTS scheme for the user with weakest channel gain also improves, compared to that of the uniform sources. Furthermore, the signal-to-noise (SNR) gain of the new BTS scheme over the uniform sourcesis calculated. As a consequence, the novel BTS scheme would improve the performance of the user with weakest channel gain as well as that with the stronger channel gain for SSC NOMA with a non-uniform source.

• 한국정보시스템학회지:정보시스템연구
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• 제16권1호
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• pp.179-200
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• 2007

In this research, we study how task and KMS fit influences on KMS performance in large corporations during its practical use. Based on the task-technology fit theory and information system success model, we developed a research model by considering the characteristics of KMS for supporting tasks. We try to verify how individual traits, task traits, and KMS Units affect task-KMS fit and how task KMS fit influences on KMS performance. We surveyed 212 employees who were using KMS and working for the large-sized manufacturing firms. We analyzed the collected data from LISREL 8.54 for Windows, and found the following significant results. First user satisfaction is increased when KMS provides knowledge to help to perform task rather than KMS' functionality. Second, user satisfaction is increased when KMS is suitable for performing task Hence, we verified task-KMS fit is an antecedent of user satisfaction. Third, task-KMS fit and user satisfaction have significant impacts on KMS performance. And user satisfaction affected more heavily on KMS performance than task-KMS fit did. As a result, we realized an individual performance can be improved when task KMS fit is high and, consequently, user satisfaction is increased. Forth while the usefulness of task-KMS fit is demonstrated, causal factors such as individual traits, task traits, and KMS traits significantly affect task-KMS fit. Formalization and knowledge trait we significant in enhancing user satisfaction, but KMS self-efficacy, autonomy, md system trait are not. These results indicate that task-KMS fit variable is useful as a measure of KMS performance as well as that of user satisfaction. Based on these results, we conclude that when KMS supports task activity, performance can be significantly improved by coordinating the task with KMS.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제21권5호
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• pp.379-386
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• 2015

본 논문에서는 스마트폰 사용자 중심의 반응 완료 시간에 대한 동적 분석을 활용하여 사용자가 실제 인지하는 성능 중심의 새로운 최적화 프레임워크를 제안한다. 이를 위하여 먼저 스마트폰 응용프로그램에서 사용자가 실제 인지하는 성능에 대한 평가 지표로써 사용자 중심 반응 시간을 정의한다. 또한, 이러한 사용자 중심 반응 시간의 동적 탐색에 기반하여 사용자가 인지할 수 있는 성능 병목 지점을 최적화의 힌트로써 개발자에게 제공하는 사용자 중심 반응 시간 분석 도구의 설계와 개발에 대하여 소개한다. 제안한 사용자 중심 반응 시간 분석 도구를 갤럭시 넥서스 스마트폰에 구현하여 그 정확도와 계산부하를 평가한 결과, 전체 반응 시간의 1% 미만의 계산 부하로 카메라를 이용하여 측정한 결과 대비 92%의 정확도를 보였다. 제안한 도구의 효율성 평가를 위하여 소스 코드가 공개되어 있는 안드로이드 응용프로그램의 성능 개선에 제안한 도구를 활용하여 최대 16.4%의 성능 향상을 달성하였다.