• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.826-841
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• 2018

The military satellite communication of ROK military, ANASIS is designed for analog data such as voice and streaming data. ANASIS cannot fully support ALL-IP communications due to its long propagation delay. The next generation satellite communication system is being designed to overcome the limitation. Next generation satellite communications system considers both high-speed and low-speed networks to support various operating environment. The low-speed satellite supports both broadband and narrow-band communication. This network works as the infrastructure for of wide-area internetworking over multiple AS's in the terrestrial network. It requires minimum satellite frequency and minimum power and works without PEP and router. In this paper, we propose a network operation structure to enable the inter-operation between high and low-speed satellite networks. In addition, we propose a data link protocol for low speed satellite networks.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.1-11
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• 2012

This paper is the study on the development of a torque precision measuring system using the curve fitting algorithm. This system can be divided into the hardware part and the software part. The hardware part consists of the main base board, the DAQ(Data Aquisition) board and Calibration parts. The software part consists of the software filter module and the curve fitting algorithm module. We have tested the torque transducer including the strain gauge for 200 Nm range and have analyzed the data acquired with the curve fitting algorithm by using this system. The DAQ board converts the electric signal induced by the transducer to the digital value precisely by using the shunt calibration procedure. The main board including the curve fitting algorithm calculates the exact digital torque value by using the digital value from the DAQ board. In this study, we confirmed that the result of the appropriate high-order power-series polynomial function is more accurate than the result of the low-order power-series polynomial through the system.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.34-41
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• 2021

Recently, a lossless non-successive interference cancellation (SIC) non-orthogonal multiple access (NOMA) implementation has been proposed. Such lossless NOMA without SIC is achieved via correlated superposition coding (SC), in comparison with conventional independent SC. However, only high-correlated SC was investigated in the lossless non-SIC NOMA implementation. Thus, this paper investigates low-correlated SC, especially a lossless interval, owing to low-correlation between signals. First, for the low-correlated SC scheme, we derive the closed-form expressions for the two roots with which the lossless interval is defined. Then, simulations demonstrate that the lossless interval of low-correlated SC NOMA is enlarged, with a degraded middle interval, compared to that of high-correlated SC NOMA. Moreover, we also show that such tendency becomes stronger as the value of the correlation coefficient varies. As a result, the proposed low-correlated SC scheme could be considered as a promising correlated SC scheme, with the enlarged lossless interval in NOMA toward the future sixth-generation (6G) ultra-reliable low-latency communications (URLLC).

• Journal of Korea Technology Innovation Society
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• v.8 no.spc1
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• pp.297-322
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• 2005

The paper aims to analyze the logic and power of open source software (OSS), and to show the ways in which Korean government and companies support developing countries in the field of software development. Many developing countries are considering software industry to be a strategic industry due to the fact that software industry seems to be labor-intensive, or rather knowledge-intensive industry. In this regard, developing countries without huge financial investment can achieve certain level of economic development while leveraging software industry. Concerning software development tools, among recent trends OSS has been regarded as a viable alternative software development tool for developing countries. In developing countries, OSS is believed to resolve some difficulties caused by proprietary software such as Microsoft Windows, which is too expensive to buy for users and developers in low-income developing countries. In this sense, OSS has been considered as only solution for software developing because OSS is able to reduce the cost of software development and to enhance the technological capabilities of developing countries. In addition to the benefit of low cost, we have to shed light on the business model of OSS that is not to sell software licence, but to provide technical support and services. In order to use OSS as much as they can, developing countries have to invest for educating human resources who can develop and implement software system using OSS. These OSS-related policies can lead developing countries to developed countries.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.71-79
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• 2006

Recently, embedded systems like mobile and portable devices are quickly disseminated around the world. Since these.devices need more computation power as the applications become gradually complicated, the bettery lifetime becomes the most serious constraints. So research efforts have been focused on reducing the power consumption, resulting in producing devices with low-power H/W and S/W components. In this paper, we propose a low-power Java API set using the dynamic power management (DPM) scheme in the J2ME Java Platform on the real-time operating system UbiFOSTM and show that we could save energy up to 30% through experiments using the API set.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.69-78
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• 2007

In recent years, embedded mobile systems have been expanding their application domains from embedded portable devices which only execute a specialized application such as MP3 player or digital camcoder to digital convergence devices which execute more complicated applications converged various functionalities such as video and audio play, digital dictionary, DMB, games, phone, etc. As it requires the increasing hardware performance such as more faster CPU and more larger RAM, display, disk size, it has brought about a corresponding increase in power consumption. However, coupled with relatively small gains in battery capacity over recent years, the importance of software architecture including intelligent power management has become paramount. In this paper, we have ported UbiFOSTM with energy saving techniques on the ARM9-based MBA2440 platform. For energy savings, we adapted the dynamic power management and the device power management schemes based on monitoring workload. Experimental results with some well-known applications show that proposed low power technique could save energy up to 24 %.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.90-94
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• 2020

Artificial intelligence (AI) is software that learns large amounts of data and provides the desired results for certain patterns. In other words, learning a large amount of data is very important, and the role of memory in terms of computing systems is important. Massive data means wider bandwidth, and the design of the memory system that can provide it becomes even more important. Providing wide bandwidth in AI systems is also related to power consumption. AlphaGo, for example, consumes 170 kW of power using 1202 CPUs and 176 GPUs. Since more than 50% of the consumption of memory is usually used by system chips, a lot of investment is being made in memory technology for AI chips. MRAM, PRAM, ReRAM and Hybrid RAM are mainly studied. This study presents various memory technologies that are being studied in artificial intelligence chip design. Especially, MRAM and PRAM are commerciallized for the next generation memory. They have two significant advantages that are ultra low power consumption and nearly zero leakage power. This paper describes a comparative analysis of the four representative new memory technologies.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.800-804
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• 2005

Load flow and short circuit fault transients of a power distribution system with wind turbines as dispersed generation units is presented. Usage of renewable energies such as wind is already a small part of total installed power system in medium and low voltage networks. In this paper, a radial power distribution system with wind turbines is simulated using DIgSILENT PowerFactory software for their influence on load flow and short circuit fault transients. Short fault occurring in dispersed generation systems causes some problems for the system and costumers such as fault level increase or the problems of sudden fluctuations in the current, voltage, power and torque of the double fed induction machine utilized in the wind turbines which have been studied and investigated.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.736-744
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• 2016

Network on chip (NoC) is an emerging technology in the field of multi core interconnection architecture. The routers plays an essential components of Network on chip and responsible for packet delivery by selecting shortest path between source and destination. State-of-the-art NoC designs used routing table to find the shortest path and supports four ports for packet transfer, which consume high power consumption and degrades the system performance. In this paper, the multi port multi core router architecture is proposed to reduce the power consumption and increasing the throughput of the system. The shared buffer is employed between the multi ports of the router architecture. The performance of the proposed router is analyzed in terms of power and current consumption with conventional methods. The proposed system uses Modelsim software for simulation purposes and Xilinx Project Navigator for synthesis purposes. The proposed architecture consumes 31 mW on CPLD XC2C64A processor.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.25-29
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• 2011

This paper describes the design and analyses of vibration driven electromagnetic energy harvester with high power generation which is suitable for supplying power generator from human body motion. The proposed harvester consists of magnet, coil, and SM (Soft magnetic Material). In order to generate more induced voltage, the SM to concentrate flux lines from end of magnetic poles was arranged into insert moving magnet. Each model was designed and analyzed by using ANSYS software to simulation. The maximum power is generated when load resistance of $1303\;{\Omega}$ is equal to coil resistance. The generated maximum power of for harvesters with SM is $677.85\;{\mu}W$ and 5.46 times higher than without SM at 6 Hz vibration frequency.