• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.269-273
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• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.197-200
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• 2013

Internet phone, communication cost and easy-to-use low-cost compared to the PSTN is a mobile phone of a conventional, and use of the Internet phone is spreading. Construction as part of the broadband convergence network(BCN), Internet service provider(KT, SKT, LG) has converted to Internet phone telephone network to all government agencies. In addition, members of the public also have an Internet phone service that you are using. In this paper, we analyze the hacking attack on IP-PBX in the IETF SIP-based that are used in Internet telephony, to the study. The test bed is constructed in the same way as the Internet telephone system to perform studies carried hacking attacks on IP-PBX, analyze the results and to extract evidence forensics. When used in crime by hacking the Internet telephone, we propose a method which can be used as evidence in forensic having legal effect.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1272-1278
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• 2009

The present paper is purposeful that I compare the materialization method of the filter of UIR and SIR, then make two filters of different methods, so both are useful. The structure of the method of UIR is simple, so it is used a commercial point of view that the client gets the characteristics what he wants. However, the needs of companies when compared to the same standards, a little more cheaply in price, a little smaller in size, better performance characteristics are expected. In this regard, the method of SIR is smaller than UIR in size, but it shows the similar characteristics of UIR, so it is expected that holds a dominant position in competitive power. In this paper, based on these conditions, I compared the methods of SIR and UIR after the design and production. The standards are Insertion Loss is less than 0.8dB, Return Loss is above 20.0dB, and the Ripple is within 0.3dB. The center frequency is settled 881.5MHzband that TX Band is used by CDMA(SKT). I compared in the same conditions in Bandwidth 25.0MHz.

• Journal of Korean Society for Quality Management
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• v.49 no.4
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• pp.483-503
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• 2021

Purpose: The purpose of this study is to investigate the service quality factors in terms of customer trust, satisfaction and loyalty of the Korean telecommunication companies(SKT, KT, LG U+). Specifically, this study presents new business strategies of the each company, thereby pursuing the innovation for mature stage. Methods: To analyze the telecommunication service quality factors that contribute to customer trust, satisfaction and loyalty, this study conducted a survey targeting customers of each company. Using the data collected, the research model was built, and empirical analysis was performed through statistical processing to verify the model. Furthermore, the clarification of each hypothesis were held including the comparison analysis of each company data. Results: The results of this study are as follows; (1) When it comes to total dataset, all quality factors including trust, satisfaction and loyalty showed significant relationship, accepting every hypothesis. (2) However, for SKT and LG U+, empathy showed no significant impact on trust while the others showed significant effect. (3) Finally for KT, all service quality factors such as responsiveness, empathy, security, and customer enablement had a significant effect on trust. Conclusion: As the development of platform industry are intensified, telecommunication companies are required to manage service quality factors thoroughly, especially focusing on customer privacy and security.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.34-39
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• 2019

One of the words frequently mentioned in our society today is the smart machine. Smart machines are machines that contain smart or intelligent functions. These smart machines have recently been applied in our home environment. These are phenomena that occur as a result of smart home. In a smart home environment, smart speakers have moved away from traditional music playback functions and are now increasingly serving as interfaces to control devices, the various components of a smart home. In this study, the technology trends of domestic and foreign smart speaker market are examined, problems of current products are analyzed, and necessary core technologies are described. In the domestic smart speaker market, SKT and KT are leading the related industries, while major IT companies such as Amazon, Google and Apple are focusing on launching related products and technology development.

• Journal of Internet of Things and Convergence
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• v.8 no.3
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• pp.41-46
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• 2022

Smart home in the Internet of Things (IoT) environment aims to provide an optimal living environment for users by connecting all devices in the home. In such a smart home environment, artificial intelligence speakers are being used as a way to manage and control all devices. The existing speaker function is changing from simple music playback to the role of an interface that controls and manages all devices in the smart home space. This study dealt with the market status and usability analysis in the US and Korea, the leader in artificial intelligence speakers. The main target companies were Amazon, Google, and Apple in the US, as well as Kakao, SKT, and KT in Korea. In addition, based on the reaction results of domestic users to artificial intelligence speakers, the derivation of major problems and directions for improvement were described.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.4
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• pp.623-630
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• 2017

This paper surveys the state-of-the-art in korean commercial Internet of Things(IoT) services for deriving the core elements of a curriculum for major courses of IoT using RaspberryPi3. First, we survey the state-of-the-art of IoT researches and commercial services in three korean major telecommunication corporations such as Korean Telecommunications (KT), LGU+ Telecommunication (LGT), and SK Telecommunication(SKT). Second, we consider the components and advantages of the RaspberryPi3 which is popular as a representative educational tool. Concludingly, this paper derives the core elements of curriculum for major courses of IoT using RaspberryPi3 from above both processes. The corresponding elements consist of platforms, hardwares, softwares, and big-data network. Based on the important design elements of the IoT curriculum using Raspberry Pie 3, we taught embedded system course to junior students for one semester. It was successfully completed and more than 90% students were satisfied with its contents and amounts.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.23-30
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• 2024

In this paper, we propose a deep learning-based personalized senior care service application. The proposed application uses Speech to Text technology to convert the user's speech into text and uses it as input to Autogen, an interactive multi-agent large-scale language model developed by Microsoft, for user convenience. Autogen uses data from previous conversations between the senior and ChatBot to understand the other user's intent and respond to the response, and then uses a back-end agent to create a wish list, a shared calendar, and a greeting message with the other user's voice through a deep learning model for voice cloning. Additionally, the application can perform home IoT services with SKT's AI speaker (NUGU). The proposed application is expected to contribute to future AI-based senior care technology.

• Journal of Service Research and Studies
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• v.5 no.1
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• pp.91-103
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• 2015

We examine the information transmission between the KT Spot and the KT Futures Index, the SK Telecom Spot and the SK Telecom Futures Index, based on the returns data offered by the Korea Exchange. The data includes daily return data from 1 January 2012 to 31 December 2014. Utilizing a dynamic analytical tool-the VAR model, Granger Causality test, Impulse Response Function and Variance Decomposition have been implemented. The results of the analysis are as follows. Firstly, results of Granger Causality test suggests the existence of mutual causality the KT Futures Index and the SK Telecom Futures Index precede and have explanatory power the KT Spot and the SK Telecom Spot However the results also identified a greater causality and explanatory power of the KT Spot and the SK Telecom Spot over the KT Futures Index and the SK Telecom Futures Index. Secondly, the results of impulse response function suggest that the KT Futures Index show immediate response to the KT Spot and are influenced by till time 4. From time 2, the impact gradually disappears. Also the SKT Futures Index show immediate response to the SKT Spot and are influenced by till time 4. From time 2, the impact gradually disappears. Lastly, the variance decomposition analysis shows that the changes of return of the KT Spot and SKT Spot are dependent on those of the KT Futures Index and the SK Telecom Futures Index. This implies that returns on the KT Spot and SKT Spot have a significant influence over returns on the KT Futures Index and the SK Telecom Futures Index. It contributes to the understanding of market price formation function through analysis of detached the KT Spot and the KT Futures Index, the SK Telecom Spot and the SK Telecom Futures Index.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.95-98
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• 2009

본 연구는 주관 감성에 따른 생리 데이터의 패턴을 분류하고, 임의의 생리 데이터의 패턴을 확인하여 각성-이완, 쾌-불쾌의 감성을 추론하기 위해 베이지안 이론(Bayesian learning)을 기반으로 한 추론 모델을 제안하는 것이 목적이다. 본 연구에서 제안하는 모델은 학습데이터를 분류하여 사전확률을 도출하는 학습 단계와 사후확률로 임의의 생리 데이터의 패턴을 분류하여 감성을 추론하는 추론 단계로 이루어진다. 자율 신경계 생리변수(PPG, GSR, SKT) 각각의 패턴 분류를 위해 1~7로 정규화를 시킨 후 선형 관계를 구하여 분류된 패턴의 사전확률을 구하였다. 다음으로 임의의 사전 확률 분포에 대한 사후 확률 분포의 계산을 위해 베이지안 이론을 적용하였다. 본 연구를 통해 주관적 평가를 실시하지 않고 다중 생리변수 인식을 통해 감성을 추론 할 수 있는 모델을 제안하였다.