• Journal of the Korean Society of Earth Science Education
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• v.8 no.3
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• pp.355-366
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• 2015

The purpose of this study was to investigate the elementary school pre-service teachers' and in-service teachers' and STEAM leader school teachers' difficulties and requirements in the relation to STEAM Education. For this study, 49 pre-service teachers, 57 in-service teachers, 16 leader school teachers in G Area were selected. And they conducted the survey. The results of this study were as follows. First, in order to minimize elementary teachers' physical burden actually, it is necessary to distribute STEAM teaching materials including various and specific programs to the schools in the booklet. Second, for the fast and effective spreading of STEAM, it also should be permitted the pre-service teachers to access STEAM homepage, which is limited to teachers. Third, we should make circumstance to research on STEAM through collaboration with colleagues freely. Therefore, we should give intensive training and consulting opportunities to science teacher. Because they who is getting stronger in this field to do this can furnish other colleagues to teaching tips and information in the relation to STEAM education. By all this fulfillment simultaneously, STEAM will be settlement in elementary school in the short period.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.5
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• pp.353-358
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• 2018

We herein analyze the service traffic characteristics and spectrum of the 5G mobile communication and suggest the effective 5G network deployment method for 5G mobile communication services. The data rates of the 5G mobile communication are from several kbps (voice and IoT) up to 1 Gbps (hologram, among others). The 5G mobile communication services show the diverse cell coverage environments owing to the use of diverse service data rates and multiple spectrum bands. To effectively support the 5G mobile communication services, the network deployment requires the optimization of the service coverages for new service environments and multiple spectrum bands. Considering the 5G spectrum bandwidth debated at present, if the 5G services of 100 Mbps can be supported in the 200 m cell edge using the 3.5 GHz spectrum bands, the 5G services of the 1 Gbps hologram and 500-Mbps 4k UHD can be supported in the cell edges of 50 m and 100 m using the 28 GHz spectrum bands. Therefore, the 5G services can be supported effectively by the 5G network deployment using spectrum portfolio configurations to match the diverse 5G services and multiple bands.

• Korean Management Science Review
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• v.26 no.3
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• pp.169-184
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• 2009

Recently, mobile telecommunication businesses contend with each other to expand their customer base by using aggressive marketing strategies. In order to determine if there strategies are effective, customer's switching behavior needs to be studied. This study identifies and analyzes direct, indirect factors that may customer switching behavior : attractiveness of alternatives, network externality, and switching cost. Results reveals that attractiveness of alternatives, network externalities have a direct impact on customer switching behavior. These two factors also have moderating effects on customer switching behavior but the switching cost does not In short, network externalities and alternatives strategically determine the success of 3.5G service. In this regard, mobile business should improve their own attractiveness of alternatives by developing specialized service in 3.5G service.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.3
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• pp.1-5
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• 2014

We study the paper Zhernovyi and Zhernovyi [Zhernovyi, K.Y. and Y.V. Zhernovyi, "An $M^{\Theta}/G/1/m$ system with two-threshold hysteresis strategy of service intensity switching," Journal of Communications and Electronics, Vol.12, No.2(2012), pp.127-140]. In the paper, authors used the Korolyuk potential method to obtain the stationary queue length distribution. Instead, our note makes an attempt to apply the most frequently used methods : the embedded Markov chain and the supplementary variable method. We derive the queue length distribution at a customer's departure epoch and then at an arbitrary epoch.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.351-355
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• 2010

The service which is required wide bandwidth is growing in these days, so building up High Speed communication system is being required. The Task Force team of IEEE 802.3ah set the EPON as a standard; next generation subscriber access network. For offering a high quality service, 10G EPON that is changed from 1Gbps uplink downlink bandwidth to 10Gbps is come up. Although Kramer had studied 10G EPON there was a QoS limitation, when load is low, End-to-End maximum delay is increased. This paper is suggesting time synch ronization method, resource reservation method, band width allocation method. We confirmed that 10EPON was able to offer quality service by the result of the OPNET.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.4
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• pp.22-29
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• 2003

In the virtual home environment (VHE), which was proposed to offer global roaming and personal service environment portability, user's profiles and service logics are conveyed from home network to visited network to provide services at the visited network. Because user's profiles and service logics may contain confidential information, some procedures for mutual authentication among entities for offering confidence are needed. For these issues, we propose and analyze three 3-Party mutual authentication Protocols adaptable to the VHE in 3G ; password based mutual authentication protocol, mutual authentication protocol with CHAP and key exchange and mutual authentication protocol with trusted third party.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.111-119
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• 2013

Eleven mycotoxins, including aflatoxins, ochratoxin A, fumonisins, zearalenone, T-2 toxin, deoxynivalenol, and HT-2 toxin, were analyzed simultaneously in rice, barley, and maize produced in 2011 by liquid chromatography coupled with triple quadrupole mass spectrometry (LC/MS/MS). Limits of detection (LOD) are 0.2 ${\mu}g/kg$ for aflatoxin $B_1$, and $G_1$, 0.3 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.1 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 3.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Limits of quantification (LOQ) were 0.6 ${\mu}g/kg$ for aflatoxins $B_1$, and $G_1$, 0.9 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.3 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 10.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Recoveries for 11 mycotoxins ranged from 70.45 to 111.11%. Fumonisins, deoxynivalenol, and zaeralenone were detected from 0.9 to 334.0 ${\mu}g/kg$ in the polished rice, barley and raw corn cultivated in Korea. Other mycotoxins were not detected. Deoxynivalenol contamination was mainly found in barley (24 out of 43 samples) and the average value in positive samples was 113.30 ${\mu}g/kg$.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.177-179
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• 2011

A new soybean cultivar 'Daewang' was released by Agricultural Research & Extension Services, Gangwon Province in 2008. The Goals of breeding the variety was for large seed size, high yield, lodging tolerance and resistance to diseases such as soybean mosaic virus (SMV) and bacterial pustule. 'Daewang' was derived from the cross of GWS91, which has yellow seed coat, large seed size and late maturity, and 'Seokryang-putkong', which has large seed size and early maturity. The preliminary, advanced and regional yield trials for evaluation and selection were carried out from 2002 to 2007. It has a determinate growth habit with purple flower, yellow seed coat, yellow hilum and large seed weight (33.6 g per 100 seeds). The maturity date of 'Daewang' is 16 days later than the 'Taekwang'. It has a high content of total isoflavone ($1,851{\mu}g/g$). The average yield of 'Daewang' was 2.68 MT/ha in the regional yield trials (RYT) carried out in four locations in Gangwon province from 2004 to 2007 which was 4 percent higher than the check cultivar 'Taekwang'.

• Electronics and Telecommunications Trends
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• v.38 no.2
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• pp.46-55
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• 2023

Extended reality (XR) provides an immersive virtual experience by using various media. The XR virtual environment enables interactions between the real and virtual worlds in virtual, augmented, and mixed reality scenarios. XR is being used in various areas such as industry, medical care, road transportation, gaming, education, and culture. XR and multimedia enhancement are important business scenarios for fifth-generation (5G) mobile networks. As users' demand for emerging media services gradually increases, enhancements in networks should be implemented for delivering multimedia services such as XR. We describe related standardization trends and requirements of the XR service in 5G mobile networks. We also discuss technological enhancements for 5G mobile networks as specified by the 3GPP SA2 working group.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.173-182
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• 2022

Healthcare organizations are overwhelmingly embracing smart value-based care strategies, which focuses on providing superior treatment at a significantly lower cost and quality of service (QoS). For these purposes, fifth generation (5G) of mobile service provides an innumerable improvement that clearly outperforms previous generations e.g., 3G and 4G. However, as with most advancements, 5G is projected to introduce new challenges, prompting the community to think about what comes next. This research was conducted to examine the most recent smart 5G technology applications and the solutions they provide to the healthcare industry. Finally, the paper discusses how the upcoming 6G technology has the potential to transform the future of healthcare sector even beyond the current 5G systems.