• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.498-503
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• 2010

Recently, the industrial electric customers require a digital switchgear which can improve the safety and reliability of the power supply, and the quality of electric power by on-line monitoring the electric power information based on the internet under the ubiquitous environments. Accordingly, in this paper, a industrial switch-gear prototype is designed based on the power supply method of three phase, four-line type, and then a three-phase electric management module of the digital switchgear is made for industrial electric customer system. Finally, the three-phase voltage and current measuring function of the prototype is verified from real power load test.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.1847-1853
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• 2014

The PAPR of the input signal is increased due to OFDMA signal in a mobile communication system. High efficiency of a power amplifier, which accounts for power consumption, is a very important key technology. Digital Pre-Distortion techniques were used to improve the linearity of the power amplifier. The Asymmetric Doherty scheme was used to improve the efficiency of the power amplifier. In this paper, we propose a new structure of Asymmetric Doherty. Drive power amplifier part is separated as main path and peak path, and phase shifter is employed to improve power combine characteristics of the Doherty Amplifier. Also, envelope tracking technology for drive gate bais in drive peak amplifier is used to improve efficiency.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.6
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• pp.253-265
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• 2022

This paper examines South Korea's past developmental experience and its current strategy and policy initiatives to overcome global and domestic challenges and sustain economic growth in the twenty-first century, the digital and global era, to explain how the country became a high-income economy. The findings of this research highlight the following three factors: First, the most significant factor in rapid industrialization was the adoption of an outward-looking strategy, with the help of a highly skilled workforce and the development of high-tech manufacturing and services sectors, which was supported by the government plans. Second, the high R&D intensity helped South Korea become a global leader in information and communication technologies, which has emerged from a top-down innovation system that promotes close collaboration between government, industry, and the academic community. Third, according to the recently released Global Entrepreneurship Index, South Korea tops the region in entrepreneurship environment. Among the list of criteria, South Korea dominates in the ease of starting a business and enforcing contracts. They all play a significant role in encouraging investment, production, communication, and, eventually, economic growth. Finally, this paper suggests forward-looking developments promoting transformation and diversification into high-tech manufacturing and digital and green technologies.

• Korean Journal of Optics and Photonics
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• v.11 no.6
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• pp.447-451
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• 2000

In this paper, an adaptive equalizer which has been widely used in communication channel and high-density storage system was adopted to mitigate ISI and improve BER generated during storage and retrieval process of the digital holographic memory system. Our experimental results show that the BER performance with an adaptive equalizer is improved about 19.6% on average compared to the binary-decision process by global thresholding. lding.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.401-406
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• 2013

In this paper, the optimum transmission method is proposed to save the energy and to increase the throughput of the adaptive modulation mobile radio system with frame length control. Traditionally, adaptive modulation has been used to improve the throughput using the power margin of the system design. Considering the frame length vs energy saving and adaptive modulation, the optimum transmission method is proposed for hub and mobile station each.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1055-1058
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• 2005

The present paper designed a weight measuring instrumentation system in which data conversion and a series of signal processing were totally equipped. 16 loadcell are incoming sensors and each output of the loadcell was amplified and filtered for proper analog signal processing. Several measuring instrumentation OP amps and general purposed OP amps were used. 12 bits A/D converters converted analog signals to digital bits and a PIC microprocessor controlled the 16 channels of loadcell. RF RS232 modules were used for wireless communication between the PIC microprocessor and an ethernet host for a remote sensor monitoring system development.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.658-666
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• 2003

In this paper, we analyzed standard and characteristic of portable microwave digital FPU(Field Pick Up) transmission system in AWGN channel environment as basis step of research about share way of M/W broadcasting relay frequency. And we analyzed system performance through simulator design. Domestic case, digitize progress about broadcasting relay is propeled. Therefore, we wish to utilize to basis data about interference evaluation and domestic broadcasting relay standardization for reassignment of M/W band broadcasting relay frequency.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.86-92
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• 1987

We implement an universal signaling equipment including many kinds of singling devices just as R2 MFC seder.receiver DTMF sender/receiver Tone sender sued in Digital Switching System the universal signaling equipment has two parts sender part and receiver part. The sender part is implemnted with ROM-LOOK-UP Table method and the receiver part is implemnted that the equipment satisfies the Recomandations of CCITT. Also the capability of the equipment is evaluated by the LCS(Local Call Simulatior)Test in the TDX-1A system.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.295-298
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• 1997

We developed the system that enables patients to be treated at home during their daily life through digital telemetry and public communication line. This system records and transfers ECG signals through wireless digital telemetry unhindering the patient's normal activities in long-term recording, and transmits the processed data, which enables real-time remote examination via ISDN phone line. Patient's image, voice, and transmitted signals are transferred to medical experts in remote medical center interactively.

• International Journal of Knowledge Content Development & Technology
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• v.4 no.2
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• pp.97-108
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• 2014

Institutional repositories are essential research infrastructures for research-based universities. A properly dimensioned institutional repository has the potential to increase research impact and enhance the visibility of an institution through its scholarly outputs. The aim of the study reported in this paper was to design and develop a web-based digital repository for scholarly communications using NM-AIST as a case study. The system was developed using open source software. Findings obtained from system validation tests show that the system is a viable solution to the major challenges encountered in the management and sharing of scholarly information at the institution.