• Journal of The Korean Institute of Defense Technology
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• v.5 no.2
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• pp.10-16
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• 2023

This study establishes the operation concept of the 4th industrial revolution defense technology and communication facility-based 5G MUM-T system, and diagnoses our current situation, focusing on the case of US government technology policy, which is a leading country in 5G MUM-T system and operation. And to advance the operation of the 5G MUM-T system, reflect combat robots and drones in the detailed classification of weapon systems, early introduction of low-orbit 5G satellite communication, expansion of the use of 5G specialized networks and wholesale provision for demonstration and verification, establishment of a defense AI governance system, Suggests the necessity of a 3-class method for radiological weapon systems. For future research, it is important to respond to the technological evolution of 6G MUM-T and 6G NTN and compare and analyze each country's policy cases, such as China, Germany, the United Kingdom, and Japan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.369-390
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• 2023

Technologies for disaster management are highly sought areas for research and commercial deployment. Landslides, Flood, cyclones, earthquakes, forest fires and road/train accidents are some causes of disasters. Capturing video and accessing data in real time from the disaster site can help first responders make split second decisions which may save human lives and valuable resource destructions. In this context the communication technologies performing the task should have high bandwidth and low latency which only 5G can deliver. But unfortunately in India, deployment of the 5G mobile communication systems is yet to give a shape and again in remote areas unavailability of 4G signals is still severe. In this situation the authors have proposed, simulated and experimented a 4G-5G communication scheme where from the disaster site the signals will be transmitted by a 5G terminal to a nearby 4G-5G gateway installed in a mobile vehicle. The received 5G signal will be further relayed by the 4G-5G gateway to the fixed 4G base station for onward transmission towards the disaster management station for decision making, deployment and relief monitoring. The 4G-5G gateway acts as a relay and converter of 5G signal to 4G signal and vice versa. This relayed system can be further mounted on a vehicle mounted relay (VMR) as proposed by 3GPP in Release 18. The scheme is also in the same line of context with Verizon's, "Tactical Humanitarian Operations Response" (THOR) vehicle concept. The performance of the link is studied in different channel conditions, the throughput achieved is superb. The authors have implemented the above mentioned system towards smart campus networking and monitoring landslides activities which are common in their regions.

• Smart Media Journal
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• v.9 no.2
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• pp.16-21
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• 2020

Recently, mobile traffic is increasing exponentially as major traffic is transferred to IoT and visual media data in the dissemination of mobile communication terminals and contents use. In order to overcome the limitations of the existing LTE system, 5G mobile communication technology (5G) is a technology that meets 1000 times data traffic capacity, 4G LTE system acceptance, low latency, high energy efficiency, and high cost compared to 4G LTE system. The path loss due to the use of the frequency domain is very high, so it may be difficult to provide a service compared to the existing 4G LTE system. To overcome these shortcomings, various techniques are under study. In this paper, small cell technology is introduced to improve the system performance of 5G mobile communication systems. The performance is analyzed by comparing the results of small cell technology application, macro communication and small cell communication, and the results of the proposed algorithm application for power control. The analysis results show that the use of small cell technology in the 5th generation mobile communication system can significantly reduce the shadow area and reduce the millimeter wave path loss problem.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.7A
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• pp.730-737
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• 2007

The new wireless multimedia environment is coming because of the variety of an user requirement and a traffic increase which we can not accept in the IMT-2000 present systems. To offer the wireless multimedia service the world wireless communication company which included the ITU-R is developing the standard and technique of 4G systems. We analyzed the technique criteria of the 4G wireless communication system in this paper which is based on that of WiBro System. We referred to the technique criteria of the WiBro system and deduced an occupied frequency bandwidth which is the common element of the uplink and downlink system among main wireless communication technique criteria. And we verified this through the simulation. So we proposed the occupied frequency bandwidth for 4G wireless communication in this paper.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.487-490
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• 1991

In this study continuous alcohol fermentation of molasses by the recirculation system has investigated. After cultivation of yeast cells in the YPD medium with increasing the medium concentration from 10 to 183.5 g/l stepwisely, the fermentation medium was replaced by molasses. The maximum cell mass was 25 g/l, and the mean cell mass during the operation was 23.5g/1, which was 3.4 times higher compared with a conventional batch system. The optimum fermentation conditions with feeding molasses of 180 g/l were obtained when the fermentation was carried out at 500 rpm and at the dilution rate of 0.037 $h^{-1}$. Under these conditions we could safely operate the fermentor for 645 h without any trouble. The maximum alcohol productivity was 4.9 g$l\cdot h$ with an alcohol concentration of 53.9 g/l at the dilution rate of 0.091$h^{-1}$.

• Informatization Policy
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• v.27 no.4
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• pp.67-84
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• 2020

This study proposes a smart city service revitalization policy based on communication facility infrastructure in 5G CPS - the core of the 4th industrial revolution, R&D, and related legislations. The 5G CPS is a converged form of ICT technologies, communications facilities, and physical systems. In this study, we propose methods of creating new services for the smart city domain based on communication facilities and the cloud platform in 5G CPS - first, by improving the communication methods classification system based on the facility scale; second, by establishing the national telecommunication facility infrastructure and making long-term investment; third, by reorganizing the Smart City Act aimed at activating new services; and lastly, by expanding the national data analytics R&D and policy support.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.447-451
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• 2004

This study was conducted to establish the proper techniques of the recirculating wick hydroponics for safe seed tuber proliferation of potatoes (Solanum tuberosum L. CV. Dejima). To achieve these, several intact tubers (5, 10 and 20 g) and cut seed-pieces (two or four) were treated in wick hydroponic system beds. A polystyrene box (31cm in width, 20cm in height, 51cm in length, and $0.031m^3$ in volume) was placed on a styrofoam hox. Eight wicks $(width\;1.5cm\;{\times}\;length\;40cm) $ were put into each polystyrene hox and the boxes were filled with perlite + peatmoss (1 : 2, v/v) medium. Top fresh weight per plant increased with increasing the tuber size from 10 to 30g/tuber. As the tuber size increases from 10 to 30 g/tuher in case of uncut tuber, the marketable tuber (>5g) production per plant increased from 83.8 to 141.8 g/plant and the marketable tuber (>5g) production per plant of cut tuber was slightly higher than that of uncut treatment. Total tuber yield ranged from 4.16 to $6.56kg/m^2$ and the percentage of seed tubers was greater than $97\%$ for all treatments. These results indicate that seed tuber should be cut to produce large tuber $(\geq10g)$ in the recirculating wick hydroponic system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.8
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• pp.16-21
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• 2009

OFDM is a key technology for 4G cellular systems in the future. But when OFDM is used in cellular system environment, it has severe inter-cell interference problems. In this paper, we propose an ICIC scheme that can reduce inter-cell interference for OFDM-based 4G cellular systems. and we analyze the efficiency of the proposed scheme. Simulation is carried out according to the simplified 3GPP LTE system level simulation parameters. We have confirmed the improvement of Geometry efficiency about 4dB at the results.

• Smart Structures and Systems
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• v.14 no.4
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• pp.559-567
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• 2014

The model of unit dynamic reliability of repairable k/n (G) system with unit strength degradation under repeated random shocks has been developed according to the stress-strength interference theory. The unit failure number is obtained based on the unit failure probability which can be computed from the unit dynamic reliability. Then, the transfer probability function of the repairable k/n (G) system is given by its Markov property. Once the transfer probability function has been obtained, the probability density matrix and the steady-state probabilities of the system can be retrieved. Finally, the dynamic reliability of the repairable k/n (G) system is obtained by solving the differential equations. It is illustrated that the proposed method is practicable, feasible and gives reasonable prediction which conforms to the engineering practice.

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.129-136
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• 1998

This experiment was carried out to investigate the effect of feeding system on performance in Korean Native Commercial Chicken. A total 864 birds produced from (Cornish ♂ X (Korean Native Chicken ♂ XRhode Island Red♀)♀ ] crossbreeds in National Livestock Research Institute, for 16 weeks. Feeding system of T1 and T$_2$ were same types from hatch to 8 weeks, starter diets(O~4 weeks, mash, ME 3,100kcal, CP 22.94%), grower diets(4~8 weeks, crumble, ME 3,100kcal, CP 19.31%). Nutrient content of finisher diets of T$_1$(pellet, ME 3,200kcal, CP 20.44%) was higher than T$_2$(mash, ME 3,100kcal, CP 14.88%) in order to improve meat quality for 8~16 weeks. Fertility and hatchability of Korean Native Commercial Chicken was 83.9% and 69.7%, respectively. Viabilities of T$_1$ and T$_2$ at 0, 4, 8, 12 and 16 weeks were 98.8%, 97.9%, 96.5% and 99.1%, 95. 8%, 92.8%, 90.3%, respectively. The viability of 0 to 8 weeks was not significantly in feed treatments, but 12 and 16 weeks was significantly T$_1$ higher than T$_2$(P<0.05). Body weights of T$_1$and T$_2$ at 4, 8, 12 and 16 weeks were 551g, 1,379g, 2,441g, 3,056g and 554g, 1,360g, 2,254g, 2,956g, respectively. The body weight of 0 to 8 weeks was not significantly feed treatments but 12 and 16 weeks was significantly T1 higher than T$_2$(P<0.05). Feed conversion of T$_1$ and T$_2$ to 4, 8,12 and 16 weeks were 1.91, 2.28, 3.34, 4.23 and 1.90, 2.28, 3.53, 4.46, respectively. The feed conversion of 0 to 8 weeks was not significantly feed treatments but 12 and 16 weeks was significantly T$_1$ lower than T$_2$(P<0.05). The ME intake 1 bird per 1 day of T$_1$ and T$_2$were 3S9kcal, 357kca1, respectively, not significantly feed treatments but CP intake were 24.8g, 20.3g, respectively. T$_2$ was lower than T$_1$(P$_1$ and T$_2$were 13,426kca1, 13,819Ykcal, respectively, not significantly feed treatments but CP requirement per kg body weight gain were 928g, 763g, respectively, T$_2$ was lower than T$_1$(P<0.05).