• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.593-602
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• 2020

Recently, as research on smart farms has been actively conducted, systems for efficiently cultivating crops have been introduced and various energy systems using renewable energy such as solar, geothermal and wind power generation have been proposed to save the energy. In this paper, we propose a new and renewable energy convergence system for crops that provides energy independence and improved crop cultivation environment. First, we present LPWA-based communication node and gateway for ICT-based data collection. Then we propose an integrated monitoring server that collects energy data, crop growth data, and environmental data through a communication node and builds it as big data to perform optimal energy management that reflects the characteristics of the environment for cultivating crops. The proposed system is expected to contribute to the production of low-cost, high-quality crops through the fusion of renewable energy and smart farms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12C
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• pp.1175-1187
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• 2007

This paper proposes a novel crest factor reduction (CFR) algorithm to be deployed on WCDMA basestation. Generally speaking, it is well described that the reduction of peak-to-average ratio (PAR) yields the possibility of using low cost power amplifier such that the basesation becomes economic However, the simple reduction of PAR could degrade the signal quality measured by either peak code domain error (PCDE) or error vector measurement (EVM), and the level of channel interference constrained by adjacent channel leakage ratio (ACLR). Regarding these imperfections, this paper introduces an effective CFR algorithm in which the function of filter-dependent CFR (FDCFR) incorporated with the histogram-based waterfilling code domain compensation (HBWCDC) carries out. To verify the performance of the proposed CFR technique, substantial simulations including comparative works are conducted with obeying W-CDMA basestation verification specification. To exploit the superiority, the performance of the proposed method is tentatively compared with that associated to the simple memoryless clipping method and the memory-required filter-dependent clipping method.

• Nuclear Engineering and Technology
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• v.27 no.1
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• pp.84-95
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• 1995

Application of computer software to safety-critical systems is on the increase. To be successful, the software must be designed and constructed to meet the functional and performance requirements of the system. For safety reason, the software must be demonstrated not only to meet these requirements, but also to operate safely as a component within the system. For longer-term cost consideration, the software must be designed and structured to ease future maintenance and modifications. This paper present a software engineering process for the production of safety-critical software for a nuclear power plant The presentation is expository in nature of a viable high quality safety-critical software development. It is based on the ideas of a rational design process and on the experience of the adaptation of such process in the production of the safety-critical software for the Shutdown System Number Two of Wolsong 2, 3 & 4 nuclear power generation plants. This process is significantly different from a conventional process in terms of rigorous software development phases and software design techniques. The process covers documentation, design, verification and testing using mathematically precise notations and highly reviewable tabular format to specify software requirements and software design. These specifications allow rigorous, stepwise verification of software design against software requirements, and code against software design using static analysis. The software engineering process described in this paper applies the principle of information-hiding decomposition in software design using a modular design technique so that when a change is' required or an error is detected, the affected scope can be readily and confidently located. It also facilitates a sense of high degree of confidence in the ‘correctness’ of the software production, and provides a relatively simple and straightforward code implementation effort.

• Journal of Biosystems Engineering
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• v.9 no.2
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• pp.65-73
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• 1984

While most of researches on the performance of high temperature grain dryer have dealt mainly with improving dryer capacity and drying speed during the last twenty years, energy efficiency, in fact, has not been emphasized. Current fuel supplies and energy cost have shifted the emphasis to reducing the energy consumption for grain drying while maintaining dryer capacity and grain quality. Since the energy input for drying is relatively large, the recovery and reuse of at least part of the exhaust energy can significantly reduce the total energy consumption in existing drying systems. Unilization of exhaust heat in grain dryer either through direct recycling or by a thermal coupling in heat exchanger have been subject of a number of investigators. However, very seldom research in Korea has been done in this area. Three drying tests(non-recycling, 0.22 recycle ratio, and 0.76 recycle ratio)were performed to investigate the thermal efficiency and heat loss factors of continuous flow type dryer, and to analyze the effect of recycle ratio (weight of exhaust air recycled/total weight of input air) on the energy requriements for rough rice drying. The test results showed that when the exhaust air was not recycled, the energy lost from furnace was 15.3 percent of input fuel energy, and latent and sensible heat of exhaust air were 61.4 percent and 11.2 percent respectively. The heat which was required in raising grain temperature and stored in dryer was relatively small. As the recycle ratio of exhaust air was increased, the drying rate was suddenly decreased, and thermal efficiency of the kerosene burner was also decreased. Drying test with 0.76 recycle ratio resulted in 12.4% increase in fuel consumption, and 38.4% increase in electric power consumption as compared to the non-recycled drying test. Drying test of 0.22 recycle ratio resulted in 6.8% saving in total energy consumption, 8.0% reduction in fuel consumption, and 2.5% increase in electric power consumption as compared to the non-recycled drying test.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.101-104
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity compared to ALD and PECVD methods. It is capable of reacting to the substrate by misting an aqueous solution using ultrasonic waves under vacuum-free conditions of atmospheric pressure. In particular, Ga₂O₃ is regarded as advanced power semiconductor material because of its high quality of transmittance, and excellent electrical conductivity through N-type doping. In this study, Computational Fluid Dynamics were used to predict the uniformity of the thin film on a large-area substrate. And also the deposition pattern and uniformity were analyzed using the flow velocity and particle tracking method. The uniformity was confirmed by quantifying the deposition cross section with an FIB-SEM, and the consistency of the uniformity prediction was secured through the analysis of the CFD distribution. With the analysis and experimental results, the match rate of deposition area was 80.14% and the match rate of deposition thickness was 55.32%. As the experimental and analysis results were consistent, it was confirmed that it is possible to predict the deposition thickness uniformity of Mist-CVD.

• Archives of design research
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• v.5 no.1
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• pp.7-20
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• 1992

Since 80th, in the monetary markets due to the escalation of creditable promptness dealing of financial goods, Korea monetary business has been confronted with structual contradictions. The first like a men power reduction, inorder to meet and satisfying with cost reduction policy of the holding firms and secondly, escalation and expention of business networks or facilities inorder to meet and satis~'ing with customers continuously seeking for prompt, acurate, and helpfulness service nearly like one similar to a door to door service. Accordingly, the firms eventually poured mere sweaty money into procuring such devices for upgrading. On the contrary, however, regardless the escalation monetary expenditure may be, inorder to promote quality of the same devices are keen necessary because present days customer groups were tended to receives ample service almost like door to door service without moving too$$\mu$h apart from the immediate spot where they belongs tl or veryspot of where actually they spend instead of deep consideration of natures, quality or sttractiveness of service medias what they can received from. Under the present circumstance, the financial business firms, however, would highly suffering and recei\ulcornerves pressures from imblalance natures ofincoming and out go of the business budget due to excessive inc1ease of managerial expences. For these reasons, therefor, in order to solves, compensates, improves, and developes most effective fina\ulcornerncial service for customers can use under most pleasant environment, the establishment of adequate standardization of such service devices based on the foregoing environmental circumstances. This analytical study, therefor, mainly aimed and emphasized based on pre- estimatimation of proper de\ulcornervlopment and use of the unattended servicing devices such as Cash Dispenser and Auto Teller Machine bygeneralization, automating. and innovation of design to meet compactness and door to door like convenient service for customers which can be achieved by performing constant comparative analysis and continual study toward development of such devices those of which produced by Five (5) major domestic producers aro~nd the country.

• Archives of design research
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• v.5 no.1
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• pp.21-36
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• 1992

Since 80th, in the monetary markets due to the escalation of creditable promptness dealing of financial goods, Korea monetary business has been confronted with structual contradictions. The first like a men power reduction, inorder to meet and satisfying with cost reduction policy of the holding firms and secondly, escalation and expention of business networks or facilities inorder to meet and satis~'ing with customers continuously seeking for prompt, acurate, and helpfulness service nearly like one similar to a door to door service. Accordingly, the firms eventually poured mere sweaty money into procuring such devices for upgrading. On the contrary, however, regardless the escalation monetary expenditure may be, inorder to promote quality of the same devices are keen necessary because present days customer groups were tended to receives ample service almost like door to door service without moving too$$\mu$h apart from the immediate spot where they belongs tl or veryspot of where actually they spend instead of deep consideration of natures, quality or sttractiveness of service medias what they can received from. Under the present circumstance, the financial business firms, however, would highly suffering and receives pressures from imblalance natures ofincoming and out go of the business budget due to excessive inc1ease of managerial expences. For these reasons, therefor, in order to solves, compensates, improves, and developes most effective financial service for customers can use under most pleasant environment, the establishment of adequate standardization of such service devices based on the foregoing environmental circumstances. This analytical study, therefor, mainly aimed and emphasized based on pre- estimatimation of proper devlopment and use of the unattended servicing devices such as Cash Dispenser and Auto Teller Machine by generalization, automating. and innovation of design to meet compactness and door to door like convenient service for customers which can be achieved by performing constant comparative analysis and continual study toward development of such devices those of which produced by Five (5) major domestic producers around the country.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.389-392
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• 2010

The problem for the air pollution in the office or the indoor except a specific working area is the continuously issue since the human beings have lived in the dwelling facilities. Measures for that problem are urgently needed. It's possible to solve for the freshair of outside with enough ventilation but that is the awkward situation to be managed by person. It's feasible to supervison and control easily if you use to sensor network under the network. It works out to sense, storage, process, deliver every kind of appliances and environmental information from the stucktags and sensors. And it is possible to utilize to measure and monitor about the place of environmental pollution which is difficult for human to install. It's studied constantly since it be able to compose easily more subminiature, low-power, low-cost than previous one. And also it spotlights an important field of study, graft the green IT and IT of which the environment and IT unite stragically onto the Network. This study compose a IAQM(Indoor Air Quality Management) under the network, suggest the application of supervision and control.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.241-260
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• 2004

Trade portal site is one of the tools which makes it possible for small and medium-sized enterprises(SMEs) to manage international trade activities more efficiently by using the newest information and telecommunication technology. So Korean SMEs should utilize trade portal sites more actively to promote global competitive power. Based on the theory of service quality and an existing research related to using information technology. this research analyzed the primary factors which affect user's utilization satisfaction in using trade portal sites. According to the results of the empirical study on actual users of the representative trade portal sites by using multiple regression analysis, The primary factors, such as service quality, government policy and cost have affected user's utilization satisfaction in using trade portal site. and user's utilization satisfaction have positive effect on continuous using intention. These research results will provide many useful insights to the managers of trade portal sites, e-trade system developers and government policy makers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.467-470
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• 2010

USN(Ubiquitous Sensor Network) is the network that widely applies for life of human being. It works out to sense, storage, process, deliver every kind of appliances and environmental information from the stucktags and sensors. And it is possible to utilize to measure and monitor about the place of environmental pollution which is difficult for human to install. It's studied constantly since it be able to compose easily more subminiature, low-power, low-cost than previous one. And also it spotlights an important field of study, graft the green IT and IT of which the environment and IT unite stragically onto the Network. This study realize a IAQM(Indoor Air Quality Management) sensing mechanism composition under the network and suggest the application of Environment monitoring system outlook to measure an Environment element.