• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.240-243
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• 1999

본 논문에서는 칼만 필터 방법을 이용하여 견인 어레이의 3차원 형상을 추정하고, 어레이 합성 기법인 ETAM방법이 추정된 3차원 형상에서도 적용 가능함을 입증한다. 기존의 합성 기법들은 모두 견인 어레이가 직선 형태를 유지하고 있다는 가정을 필요로 하지만, ETAM 방법은 3차원 형상추정이 가능한 경우에 그러한 가정이 필요 없게 된다. 단, 3차원 어레이 형상에서 어레이를 확장하기 위해서는 절대 좌표를 추정할 수 있으며, 어레이가 동일한 견인 경로를 따라간다는 가정이 필요하다. 컴퓨터 모의 실험 결과 신호원의 입사각을 추정하였을 때, 주엽폭과 부엽레벨이 감소하는 등 합성이 가능함을 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1230-1233
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• 2007

DDoS 공격은 인터넷 환경에서 네트워크나 개인 호스트를 위협하는 대표적인 공격 트래픽이다. DDoS 공격은 간단한 Tool 로 공격이 가능하면서 네트워크 기반 구조에 큰 피해를 입힐 수 있기 때문에 그 심각성이 크다. DDoS 공격의 효과적인 방어와 대응을 위해서는 DDoS 공격 트래픽에 대한 정확한 분석과 탐지가 선행되어야 한다. 본 논문에서는 DDoS 공격 징후를 신속하게 탐지해 낼 수 있는 효율적인 트래픽 비율 분석법(ETAM)을 제안하고, ETAM 기법을 통해 공격을 빠르고 신속하게 탐지할 수 있음을 보인다.

• IE interfaces
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• v.19 no.3
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• pp.255-269
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• 2006

Digital manufacturing(DM) is the ability to describe every aspect of the design-to-manufacture process digitally-using tools that include digital design, CAD, office documents, PLM(Product Life-cycle Management) systems, analysis software, simulation, CAM software and so on. The major automotive companies are already deeply invested in DM with almost every process being digital rather than paper-based. But it has taken a long time for the digital process to mature into something usable and there have been some major barriers that have prevented from the DM becoming a reality. Thus many companies hesitate to make a decision of implementing the DM. This paper deals with a study investigating which factors are important for implementing the DM to industries successfully. The extended technology acceptance model (ETAM) is used as the relation model of cause and effect. The quality of hardware, the quality of software, the range of collaboration among companies and the preference of the user are defined as the external factors. Interview method is used for gathering input data, and the results are analyzed with SPSS. The results indicate that four external factors are effective on the successful implementation of DM, and the perceived usefulness is most important.

• Journal of The Korean Association of Information Education
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• v.18 no.4
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• pp.509-520
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• 2014

This study investigated the structural relationships among factors on intention to use mobile learning and suggests practical strategies to enhance learners' behavior intention in secondary school. In this study, we hypothesized that mobile computing self-efficacy, personal innovativeness, and social influence had positive effects on perceived usefulness and perceived ease of use, which ultimately had positive effects on intention to use mobile learning. In order to examine structural relationship among variables, we surveyed 289 high school students in spring semester of 2014. After collecting data, we examined causal relationship among variables using Structural Equation Modeling. The results of this study are as follows: First, mobile computing self-efficacy and personal innovativeness significantly affected perceived ease of use. Second, mobile computing self-efficacy, social influence, and perceived ease of use significantly affected perceived usefulness. Lastly, perceived usefulness and perceived ease of use significantly affected intention to use mobile learning of high school students.

• Journal of Internet Computing and Services
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• v.11 no.3
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• pp.105-119
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• 2010

The purpose of this study is to examine diverse factors influencing the adoption of IPTV services and relationships among them. To achieve the purpose, this study modified and applied the established theory of the Extended Technology Acceptance Model(ETAM) incorporating socio-cultural factor, flow experience and perceived behavioral control as related constructs. The suggested model was empirically tested through the structural equation modeling approach. The results are as follows: First, the socio-cultural factor and the perceived behavioral control have significant direct influences on the adoption of IPTV services. Second, the flow experience does not have a significant indirect influence mediated by the attitude toward IPTV services. Third, the socio-cultural factor has the significant relationships with the perceived usefulness and the perceived ease of use. Finally, the flow experience was influenced by the perceived usefulness and the perceived ease of use.

• Korean Journal of Health Education and Promotion
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• v.31 no.4
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• pp.25-36
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• 2014

Objectives: The self-management of chronic diseases is currently receiving much attention. This study applied an extended technology acceptance model (ETAM) to analyze the factors influencing acceptance of a healthcare smartphone application. Methods: Three hundred people living in Seoul and Gyeonggi who used smartphones were quota sampled. A telephone survey was conducted using a structured questionnaire based on ETAM. A path analysis was carried out using the AMOS 17.0 program, and the model was verified. Results: The analysis revealed significant factors of perceived usefulness (.374, p < .001), enjoyment (.210, p < .001), subjective norms (.168, p < .001), perceived costs (.146, p < .001), and innovativeness (.138, p < .001). Cost directly influenced intention to use health applications; self-efficacy and perceived ease of use indirectly affected intention through innovation and perceived usefulness. Conclusions: This study helped to identify the main factors that influence usage intention of smartphone applications. These findings could contribute to promoting the self-management of chronic disease through future health applications using smartphones.

• The Journal of the Acoustical Society of Korea
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• v.25 no.4
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• pp.172-177
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• 2006

Various research and development on Synthetic Aperture Sonar technique is under way to enhance bearing resolution of a SONAR system. In this paper, we estimated perturbed array shapes, and compensated distortion by using estimated away shapes and synthesized arrays in aperture domain such as an ETAM technique. As experimental data, we used the one obtained from towed array in neighboring waters of the Korean peninsula. Through simulation on data where tow-ship speed is maintained at a constant level, we confirmed that synthesis effect of increasing SNR and narrowed beam width of main lobe was consistently demonstrated for about 1 minute when coherence of target signal was maintained. Also, we showed that the synthesis effect with respect to time was constantly maintained.

• Journal of Service Research and Studies
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• v.7 no.3
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• pp.37-55
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• 2017

Recently, many business organizations have been increasingly expanding the utilization of the intelligent chatbot services for effective customer relation management. The purpose of this study is to empirically investigate the factors which affect the use of the intelligent chatbot services. Above all, the research model and the hypotheses were derived through reviewing the major relevant theories such as UX(user experience) theory(Honeycomb model), TRA(theory of reasoned action), TAM(technology acceptance model) and ETAM(extended TAM). And then, structural equation analyses using SmartPLS 3.0 for 233 valid questionnaires replies collected through the field survey was performed to test the hypotheses. Theoretically, this study can contribute to providing the conceptual framework with regard to enhancing the use of intelligent chatbot services. And practically, this study sheds new light on suggesting the guidelines to designing the UX(user experience) of the intelligent chatbot services.

• The Journal of the Acoustical Society of Korea
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• v.18 no.2
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• pp.25-31
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• 1999

An array aperture synthesis technique is proposed. The proposed method does not require the condition that the overlapped hydrophones have the identical position in space to estimate the phase correction factors. while the existing ETAM algorithm does. Therefore the proposed method increases the available data applied to extend the effective aperture length of the towed array. From the numerical experiments, the proposed method can reduce the mean square error in estimating the direction of a target signal.

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.409-418
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• 2005

This paper proposes perceived ease of use and perceived usefulness mediate this relationship. The results can be summarized as follows. First, the greater the property management system's information quality, the greater the perceived ease of use. Second, the greater the perceived ease of use, tile greater the perceived usefulness. Third, the greater the perceived ease of use, the greater the using intention of system. Forth, the greater the perceived usefulness, the greater the using intention of system. Finally, the greater the using intention of system, the greater the usage of system.