• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.156-161
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• 2014

With the proliferation of digital music, public's interest in music and desire to sing well are increasing. This paper presents the implementation of a tone correction system through a visualization of comparison between music and humming data. For this we extract MIDI note from music and humming data and then design a matching engine using DTW algorithm which is for robust matching results against local timing variation and inaccurate tempo. This system is expected to correct the user's wrong tone by visualization and feedback from the result.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.401-404
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• 2010

In multibit Sigma-Delta Modulator, DWA(Data Weighted Averaging) among the DEM(Dynamic Element Matching) techniques was widely used to get rid of non-linearity that caused by mismatching of unit capacitor in feedback DAC path. this paper proposed the improved DWA architecture by adjusting clock timing of the existing DWA architecture. 2n Register block used for output was replaced with 2n S-R latch block. As a result of this, MOS Tr. can be reduced and extra clock can also be removed. Moreover, two n-bit Register block used to delay n-bit data code is decreased to one n-bit Register. In order to confirm characteristics, DWA for the 3-bit output with the proposed DWA architecture was designed on 0.18um process under 1.8V supply. Compared with the existing architecture. It was able to reduce the number of 222 MOS Tr.

• Journal of Korean Clinical Nursing Research
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• v.24 no.3
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• pp.363-370
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• 2018

Purpose: The study was conducted to investigate correlations between self-management and physiological measurements of patients on hemodialysis according to their age. Methods: The subjects were 120 patients on hemodialysis at three hospitals in S and G cities. Data were collected using a structured questionnaire and medical records. The collected data were analyzed using descriptive statistics including t-test, ANOVA, and Pearson's correlation analysis with the SPSS 23.0 program. Results: The levels of compliance with self-management were highest in the middle-aged group. There was no significant difference in physiological measurements between the different age groups. Conclusion: The results suggest that nurses should consider characteristics of different age groups to improve the levels of self-management and physiological measurements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.853-854
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• 2014

서비스 산업에 있어 효율적인 경영을 위해서는 시시각각으로 변하는 고객의 니즈를 파악하기 위해 그 어느 때 보다도 고객피드백이 필요한 시대이다. 기존의 설문조사를 이용한 방법은 자발적이고 즉각적인 고객의 의견을 수집하는데 한계가 있어 최근에는 서비스의 즉각적이고 사실적인 피드백을 얻기 위해서 조사에 대한 인지 없이 능동적이고 자발적으로 작성한 소셜미디어 상의 게시글을 수집하고 분석하는 방법을 이용하여 고객의 피드백을 파악하고 있다. 본 연구에서는 이러한 소셜 미디어상의 빅데이터 정보를 분석하는 기술의 적합성을 평가하는 방법을 제안한다. 수집 적합성 평가는 사전 설정된 수집규칙에 의해 수집된 수집데이터에 대한 검증방안을 수립하고 샘플링 조사를 수행하여 목표 수준의 정확도가 이루어지지 않을 경우 수집엔진에 대한 기능 보완 및 수집 주기 재설정 등 수집 규칙을 재설정하고 샘플조사 범위를 확대하여 평가하는 일련의 과정 반복을 통해 수집 정확도를 향상시킨다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.176-179
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• 2022

In this paper, we consider a sectorized wireless powered sensor network (WPSN), wherein sensor nodes are clustered based on sectors and transmit data to the cluster head (CH) using energy harvested from a hybrid access point. We construct a system model for this sectorized WPSN and find optimal coordinates of CH that maximize the achievable transmission rate of sensing data. To obtain the optimal CH with low overhead, we perform an asymptotic geometric analysis (GA). Simulation results show that the proposed GA-based CH selection method is close to the optimal performance exhibited by exhaustive search with a low feedback overhead.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.32-33
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• 2022

팬데믹이후 온라인 커뮤니케이션이 가속화되면서 개인화의 현상이 두드러지고 있는 가운데 도시의 정보시스템의 많은 부분들이 디지털 트윈으로 가고 있다. 때문에 오프라인의 사이니지 등은 이미 개인화에 익숙한 사용자에게 만족도나 낮고 이를 반영하여 다양화시키기에는 많은 예산이 소요되며 물리적 한계가 있다. 본 연구는 사용자 중심 프로세스의 기술 융합 연구를 통해 이러한 오프라인 정보 표기와 전달 등의 문제점을 해결하고자 하였다. 본 논문은 이러한 목적을 가지고 개인화 기반 도시 인포메이션 시스템의 물리적 사이니지와의 정보 데이터 간의 상호운용을 실현화하는 연구를 진행하였다. QR 코드 등 비쥬얼 코드-기반 기존의 인터랙션 기술들의 장점을 활용하고 AI 기반의 필터 시스템을 도입하여 도시 복합정보데이터와 개인데이터와의 연동 및 변별 시스템을 설계하여 AR서비스 환경을 디자인 하였다. 개인화 서비스를 위하여 'Personal Data'와 타사용자의 'Feedback Data를 기존의 클라우드 정보와 AI-Analytic-Process에 개입시켜서 개인화 기반의 서비스 시스템 모델로 개발하였다.

• Asia pacific journal of information systems
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• v.30 no.1
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• pp.94-119
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• 2020

Digital platforms characterized by network effects enable provisioning of various types of services and provide a mechanism for linking producers and consumers. Identifying the key Quality of Service attributes of such platforms is vital for their continued success and growth. In this paper, a set of quality attributes for platforms is first extracted from different extant quality models. Then actual user feedback data from three platform providers are analysed and mapped against the set of quality attributes to determine the key attributes that are relevant. These findings are corroborated with qualitative data from interviews of different stakeholders. The results show that service quality characteristics are important to the success of platforms. Functional characteristics of platforms assume importance where the digital contributions of the platform is higher. Apart from these, 'fitness for use' as a major determinant of quality is also important in digital platforms.

• Journal of Information Technology Applications and Management
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• v.31 no.1
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• pp.163-175
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• 2024

This study conducts topic modeling analysis on four electric scooter sharing platforms: Alpaca, SingSing, Kickgoing, and Beam. Using user review data, the study aims to identify key topics and issues associated with each platform, as well as uncover common themes across platforms. The analysis reveals that users primarily express concerns and preferences related to application usability, service mobility, and parking/accessibility. Additionally, each platform exhibits unique characteristics and challenges. Alpaca users generally appreciate convenience and enjoyment but express concerns about safety and service areas. SingSing faces issues with application functionality, while Kickgoing users encounter connectivity problems and device usability issues. Beam receives overall positive feedback, but users express dissatisfaction with application usability and parking. Based on these findings, scooter sharing service providers should focus on enhancing application features, stability, and expanding service coverage to meet user expectations and improve customer satisfaction. Furthermore, highlighting platform-specific strengths and providing tailored services can enhance competitiveness and foster continuous service growth and development.

• ETRI Journal
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• v.46 no.1
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• pp.48-58
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• 2024

This paper presents the development of language tutoring systems for nonnative speakers by leveraging advanced end-to-end automatic speech recognition (ASR) and proficiency evaluation. Given the frequent errors in non-native speech, high-performance spontaneous speech recognition must be applied. Our systems accurately evaluate pronunciation and speaking fluency and provide feedback on errors by relying on precise transcriptions. End-to-end ASR is implemented and enhanced by using diverse non-native speaker speech data for model training. For performance enhancement, we combine semisupervised and transfer learning techniques using labeled and unlabeled speech data. Automatic proficiency evaluation is performed by a model trained to maximize the statistical correlation between the fluency score manually determined by a human expert and a calculated fluency score. We developed an English tutoring system for Korean elementary students called EBS AI Peng-Talk and a Korean tutoring system for foreigners called KSI Korean AI Tutor. Both systems were deployed by South Korean government agencies.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.44-51
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• 2002

This paper describes the performance evaluation and analysis of an Orthogonal Frequency-Division Multiplexing (OFDM) system having the least Inter Symbol Interference (ISI) in a multi-path fading channel environment. Wireless Local Area Network (W-LAN) in accordance with IEEE 802.11a and IEEE 802.11b provides high-speed transmission to universities, businesses and other various places. In addition, service providers can offer a public W-LAN service on restricted areas such as a subway. The proliferation of W-LAN has led to greater W-LAN service demands, but problems are also on the rise in offering a good W-LAN service. In particular, urban areas with high radio wave interference and many buildings are vulnerable to deteriorated QoS including disconnected data and errors. For example, when high-speed data is transmitted in such areas, the relatively high frequency generates ISI between Access Points (AP) and Mobile Terminals (such as a notebook computer), leading to a frequency selective fading channel environment. Consequently, it is difficult to expect a goodW-LAN service. The simulation proves that the OFDM system enables W-LAN to implement QoS in high-speed data transmission in a multi-path fading channel environment. The enhanced OFDM performance with 52 sub-carriers is verified via data modulation methods such as BPSK, QPSK and 16QAM based on IEEE 802.11a and punched convolutional codes with code rate of 1/2 and 3/4 and constraint length of 7. Especially, the simulation finds that the OFDM system has better performance and there is no data disconnection even in a mobile environment by applying a single tap equalizer and a decision feedback equalizer to a mobile channel environment with heavy fading influence. Given the above result, the OFDM system is an ideal solution to guarantee QoS of the W-LAN service in a high-speed mobile environment.