• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.2
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• pp.94-102
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• 2004

The digital electronic switching system has some problems, when this system processes OAM(Operation, Administration And Maintenance) messages about the fault, the traffic, the account, and the performance, etc., at the present. One of these problems is that each the module processing these messages in the digital electronic switching system can not process OAM messages out of another digital electronic switching system. Each the module processing these OAM messages, that is, has been programmed in order to process only the OAM message out of the digital electronic switching system mounting itself, not to process the message out of the digital electronic switching system based on another platform. Therefore, we studied on methods that could process OAM messages out of all digital electronic switching systems and, first of all, developed the MGS(Message Gathering System) to be able to accept and process the fault message of OAM messages out of all digital electronic switching systems in real time.

• The Journal of Information Systems
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• v.31 no.3
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• pp.89-108
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• 2022

Purpose The purpose of this study is to clarify the conceptualizations of mandatory and reward that have come into focus in the definition of digital shadow work. And explore how users in a shared services environment view cost and coercion from the perspective of digital shadow work. Design/methodology/approach We conducted one-on-one interviews with 4 participants, with each interview being an average of 25 minutes. Based on literature review, stakeholder observation, and interviews on digital shadow work so far, very objective results can be derived through triangulation based on the basis of multiple sources. Findings According to the results of the preliminary study, there are some rewards for each type of digital shadow work, but time saving and service convenience are considered more than financial rewards. Unfair demands in determining whether to implement them in consideration of the difficulty and expected benefits of the demanding digital work can cause dissatisfaction with the service. Academic implications and future research directions are also discussed.

• Information Systems Review
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• v.16 no.3
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• pp.49-68
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• 2014

These days, consumers have increasingly preferred to digital real-time streamlining and downloading to listen to music because this is convenient and affordable for the consumers. Accordingly, sales of music in compact disk formats have steadily declined. In this regards, online digital music has become a new communication channel to listen musics, where digital files can be delivered over various online networks to people's computing devices. The majority of online digital music distributors has Music Recommender Systems for sales of digital music on their websites. Music Recommender Systems are parts of information filtering systems that provide the ratings or preferences that users give to music. Korean online digital music distributors have Music Recommender Systems. But those online music distributors didn't provide any rules or clear procedures that recommend music. Therefore, we raise important questions as follows: "Is Music Recommender Systems Fair?", "What is the impact of Music Recommender Systems on online music rankings and sales?" While previous studies have focused on usefulness of Music Recommender Systems, this study investigates not only fairness of Current Music Recommender Systems but also Relationship between Music Recommender Systems and online Music Charts. This study examines these issues based on Bandwagon effect, ranking effect, Slot effect theories. For our empirical analysis, we selected the most famous five online digital music distributors in terms of market shares. We found that all recommended music is exposed to the top of 'daily music charts' in online digital music distributors' websites. We collected music ranking data and recommended music data from 'daily music chart' during a one month. The result shows that online music recommender systems are not fair, since they mainly recommend particular music that supported by a specific music production company. In addition, the recommended music are always exposed to the top of music ranking charts. We also find that recommended music usually appear at the top 20 ranking charts within one or two days. Also, the most music in the top 50 or 100 ranks are the recommended music. Moreover, recommended music usually remain the ranking charts more than one month while non-recommended music often disappear at the ranking charts within two week. Our study provides an important implication to online music industry. Because music recommender systems and music ranking charts are closely related, music distributors may improperly use their recommender systems to boost the sales of music that related to their own companies. Therefore, online digital music distributor must clearly announce the rules and procedures about music recommender systems for the better music industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.336-342
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• 2017

Recently, there has been an increasing need for underwater communication systems to monitor ocean environments and prevent marine disasters, as well as to secure ocean resources. Most underwater communication systems adopted acoustic communication with a consideration of attenuation, absorption, and scattering in conductive sea water, and developed fully digital modems based on processors. In this study, a digital up converter (DUC) and a digital down converter (DDC) was developed for an underwater basestation based on underwater acoustic communication systems. Because one of the most important issues in underwater acoustic communication systems is low power consumption due to environmental problems, this study developed a specific hardware module for DUC and DDC. It supported four links of underwater acoustic communication systems and converted the sampling rate and frequency. The systemwas designed and verified using Verilog-HDL in ModelSim environment with the test data generated from baseband layer parts for an underwater base station.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.371-383
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• 2004

In this paper we consider technological requirements to broadcast digital television signals using single frequency networks (SFN) in the Advanced Television Systems Committee (ATSC) transmission systems and propose equalization digital on-channel repeater (EDOCR) that overcomes the limitations of conventional digital on-channel repeaters (DOCRs). Since there are no forward error correction (FEC) decoder and encoder, the EDOCR does not have an ambiguity problem. In addition, since an adaptive equalizer in the EDOCR removes multi-path signals, additive white Gaussian noise (A WGN), and feedback signal due to low antenna isolation, the EDOCR may have good output signal quality with high power.

• The Journal of Information Systems
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• v.32 no.4
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• pp.211-227
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• 2023

Purpose In the contemporary landscape, marked by the enduring impact of COVID-19 and the recent disruptions stemming from the conflict in Ukraine, the purpose of this study is to navigate the era characterized by pervasive risk and uncertainty. Specifically, the study aims to dissect the impact of the COVID-19 outbreak on digital transformation, exploring the factors influencing this process and considering the multifaceted dynamics at play. The focus extends to the post-COVID-19 landscape, scrutinizing the implications and meanings of digital transformation both before and after the pandemic. Additionally, the study delves into future digital trends, with particular attention to climate and environmental issues, emphasizing corporate responsibilities in averting crises similar to COVID-19. The overarching goal is to provide a holistic perspective, shedding light on both positive and negative facets of digital transformation, and advocating for regulatory enhancements and legal frameworks conducive to a balanced and resilient digital future. Design/methodology/approach This study employs a comprehensive approach to analyze the impact of the COVID-19 outbreak on digital transformation. It considers various facets, such as smart devices reshaping daily routines, transformative changes in corporate ecosystems, and the adaptation of government institutions to the digital era within the broader context of the Fourth Industrial Revolution. The analysis extends to the post-COVID-19 landscape, examining the implications and meanings of digital transformation. Future digital trends, especially those related to climate and environmental issues, are prognosticated. The methodology involves a proactive exploration of challenges associated with digital transformation, aiming to advocate for regulatory enhancements and legal frameworks that contribute to a balanced and resilient digital future. Findings The findings of this study reveal that the digital economy has gained momentum, accelerated by the proliferation of non-face-to-face industries in response to social distancing imperatives during the COVID-19 pandemic. Digital transformation, both preceding and succeeding the onset of the pandemic, has precipitated noteworthy shifts in various aspects of daily life. However, challenges persist, and the study highlights factors that either bolster or hinder the transformative process. In the post-COVID-19 era, corporate responsibilities in averting crises, particularly those resembling the pandemic, take center stage. The study emphasizes the need for a holistic perspective, acknowledging both positive and negative facets of digital transformation. Additionally, it calls for proactive measures, including regulatory enhancements and legal frameworks, to ensure a balanced and resilient digital future.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.6
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• pp.547-553
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• 2006

This paper studies digital control of biodynamic model of HIV-1 via intelligent digital redesign (IDR). The purpose of the IDR is to develop an equivalent digital fuzzy controller maintaining the satisfactory performance of an existing continuous-time fuzzy controller in the sense of the state-matching. Some conditions for the stability as well as the global state-matching are provided.. They are given by the form of the linear matrix inequalities (LMIs) and thereby easily tractable by the convex optimization techniques. The main features of the proposed method are that 1) the generalized control scheme is provided for the multirate as well as the single-rate digital controllers; 2) a new compensated block-pulse function method is applied to closely match the states of the continuous-time and the sampled-data fuzzy systems in the discrete-time domain; 3) the two-step procedure of IDR is presented to prevent the performance degradation caused by the additional stability conditions. The applicability of the proposed approach is shown through the biodynamic model of HIV-1.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.1
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• pp.33-41
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• 2019

We propose an embedded solution to design a high-speed and high-accuracy 16bit analog-digital signal processing interface for the control systems using various external analog signals. Choosing TMS320F28377D micro controller unit (MCU) featuring high-performance processing in the 32-bit floating point operation, low power consumption, and various I/O device supports, we design and build the proposed system that supports both 16-bit analog-digital converter (ADC) interface and high precision digital-analog converter (DAC) interface. The ADC receives voltage-level differential signals from fully differential amplifiers, and the DAC communicates with MCU through 50 MHz bandwidth high-fast serial peripheral interface (SPI). We port the boot loader and device drivers to the implemented board, and construct the firmware development environment for the application programming. The performance of the entire implemented system is demonstrated by analog-digital signal processing tests, and is verified by comparing the test results with those of existing similar systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4331-4354
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• 2020

Nepal is a sensitive and disaster-prone country where safety and security risk are of high concern for travelers. Digital technologies can play a vital role in addressing safety and security issues in the country. This research work proposes a Digital tourism security system design for addressing the safety and security issues in tourism industry of Nepal. The study uses Design science research methodology to identify artifacts, interactions, information flow and dependencies between them which are then mapped with existing prevalent technology to provide design solutions. Data is obtained from interview of tourist and experts as a primary source and technical documents/draft, software documentations, surveys as secondary source. Generalized information model, Use cases model, Network architecture model, Layered taxonomy model and Digital tourism technology reference model are the outcomes of the study. The work is very important as it talks specifically about implementation and integration of digital technologies in tourism security governance at federal, provincial, municipal and rural level. The research supplements as a knowledge document for design and implementation of digital tourism security system in practice. As there is very less work on digital systems in tourism security of Nepal, this work is a pioneer and first of its kind.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.3
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• pp.227-232
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• 2006

In this paper, we propose a systematic method for intelligent digital redesign of a fuzzy-model-based controller for continuous-time nonlinear system which may also contain system uncertainties. The continuous-time uncertain TS fuzzy model is first contructed to represent the uncertain nonlinear system. A parallel distributed compensation(PDC) technique is then used to design a fuzzy-model-based controller for both stabilization. The designed continuous-time controller is then converted to an equivalent discrete-time controller by using a globally intelligent digital redesign method. This new technique is designed by a global matching of state variables between analog control system and digital control system. This new design technique provides a systematic and effective framework for integration of the fuzzy-model-based control theory and the advanced digital redesign technique for nonlinear systems with uncertainties. Finally, Chaotic Lorenz system is used as an illustrative example to show the effectiveness and the feasibility of the developed design method.