• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.116-119
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• 2021

국내 이동통신은 4 세대(4G)에서 5 세대(5G)로 전환되는 과정에 있으며 행정안전부는 기존 긴급재난문자 서비스를 5G 망으로 고도화하기 위해 준비하고 있다. 재난문자 길이의 확장, 송출 지역 세분화, 외국어 문자 지원 등을 긴급재난문자 서비스에 포함하기 위해 국내외 표준화와 검증 시스템 구축이 준비되고 있다. 본 논문에서는 해외 사례 분석을 통해 국내 5G 망으로 고도화된 긴급재난문자를 서비스하기 위해 요구되는 검증 요구사항을 정의하고 있다. 이를 기반으로 긴급재난문자 서비스를 검증할 리빙랩이 구축될 예정이다.

• Electronics and Telecommunications Trends
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• v.37 no.3
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• pp.74-84
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• 2022

The Korean mobile service market has persistently grown with the number of subscribers and volume of mobile traffic. It shows the slow diffusion of 5G subscribers, and rapid growth of both the MVNO(Mobile Virtual Network Operator) market and unlocked mobile phones. Therefore, this study derives the direction of telcos' strategies and policy implications by empirically analyzing the usage and attitude of LTE and 5G subscribers. Our major findings are as follows: First, our current mobile service subscription market constitutes most long-term customers for their incumbent carriers only by device change from lock-in with bundle services. Mobile tariffs, data speed, and benefits of bundle services are important factors affecting choices and customers' satisfaction with a provider and intentions of churning to another. Second, demand and satisfaction for using 5G are less because speeds and service tariffs act as pain points for 5G services. Third, the users' high preferences for MVNOs and unlocked mobile phones are linked to their subscription to MVNOs' low-cost plans with unlocked mobile phones on online channels. These streams lead to a big change in the market competition that MNO(Mobile Network Operator)s' market shares are expected to decrease and MVNOs' shares will be increased by two times, in the near future. Therefore, MNOs need to change their distribution strategies from offline to online channels and try to resolve the stereotype, "mobile tariffs are expensive," by enhancing their service values. Finally, as consumers prefer one-stop service in the same channel regardless of the distribution channel, policies should focus on the consumers' needs for convenience rather than on the channel separation for perfectly unlocked mobile phones.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.1-7
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• 2022

This paper aims to compare the mean object size of M/G/1/PS model with that of M/BP/1 model used in the web service. The mean object size is one of important measure to control and manage web service economically. M/G/1/PS model utilizes the processor sharing in which CPU rotates in round-robin order giving time quantum to multiple tasks. M/BP/1 model uses the Bounded Pareto distribution to describe the web service according to file size. We may infer that the mean waiting latencies of M/G/1/PS and M/BP/1 model are equal to the mean waiting latency of the deterministic model using the round robin scheduling with the time quantum. Based on the inference, we can find the mean object size of M/G/1/PS model and M/BP/1 model, respectively. Numerical experiments show that when the system load is smaller than the medium, the mean object sizes of the M/G/1/PS model and the M/BP/1 model become the same. In particular, when the shaping parameter is 1.5 and the lower and upper bound of the file size is small in the M/BP/1 model, the mean object sizes of M/G/1/PS model and M/BP/1 model are the same. These results confirm that it is beneficial to use a small file size in a web service.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.79-79
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• 2018

용과(Hylocereus undatus)는 멕시코 및 과태말라가 원산지이며 아열대 및 열대지역에서 재배되고 있으며 아시아는 베트남 타이완 중국 일본 등 국가에서 재배하고 있다. 가지에 열매가 있는 모습이 용이 여의주를 물고 있는 형과 닮았다하여 붙여진 이름이다. 지구온난화로 인한 기온상승으로 전남지역 재배에 적합한 대체 열대 및 아열대과수 개발이 필요하다. 용과는 열대과수 중 비교적 낮은 온도($10^{\circ}C$이상) 조건에서 재배 가능하여 남부지역에서 시설내 가온재배하고 있다. 국내 시설재배 중 문제점은 용과는 밤에 꽃을 피기 때문에 밤에 활동하는 매개곤충이 없어서 인공수분으로 수분문제를 해결해야한다. 인공수분의 한계시간과 수분할 경우 과실비대에 미치는 영향을 알아보고자 인공수분 시간을 개화 1시간 이내, 4~5시, 11~12시 및 무 처리(방임)로 처리하였다. 개화시기는 1차 7월 13일, 2차 8월 8일, 3차 8월 26일로 3회에 걸쳐 개화가 이루어졌으며 이시기의 화분량는 4~5시가 0.68g, 11~12시 0.47g로 1시간 이내 0.16g보다 많았고 과실비대에서 1과중은 개화11~12시가 421g, 4~5시 400g, 1시간 이내가 377g으로 처리 간에 차이는 없었지만 무처리는 185g으로 처리구와 192~236g의 유의차가 있었다. 용과의 인공수분한계시간은 다음날 아침 7시(개화 11~12시)까지 인공수분 할 경우 정상적인 착과가 이루어졌으며 과실비대를 위해서 인공수분은 필수적으로 실시해야 한다.

• Electronics and Telecommunications Trends
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• v.34 no.2
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• pp.92-100
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• 2019

Vast amounts of different service-specific requirements and vertical network slicing in a 5G network increase the complexity, cost of the network management and resource operations for carriers. To solve this problem, 3GPP is working on the standardization of NWDAF to support the automation of the 5G network by utilizing artificial intelligence technologies based on Big Data to improve the efficiency of network management and resource operation. In addition, the ETSI ZSM Industry Specification Group is developing technical standards for the automation of end-to-end network management and service delivery. This document provides an overall survey of the latest standardization issues of the NWDAF in 3GPP and ETSI ZSM for 5G network automation and intelligence.

• Journal of IKEEE
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• v.26 no.4
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• pp.693-704
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• 2022

5G service uses mid-band (n78) than existing mobile communication frequencies, so it is necessary to improve 5G coverage by utilizing low-band frequencies below 2 GHz. To this end, the application of Dynamic Spectrum Sharing technology of LTE and 5G-NR system using most of the low-band frequencies is required. In this paper, signaling overhead factors for DSS application and RF issues for terminal implementation are derived, and signaling overhead ratios from the respective perspectives of 5G-NR and LTE for the 1.8GHz band (50MHz width) that can utilize wide-bandwidth among low-band frequencies are estimated. Also handset RF issues were analyzed. Based on the analysis results, if DSS technology using low band is applied, it is expected that excellent 5G service quality can be provided due to 5G coverage improvement when LTE traffic quickly migrates to 5G-NR.

• Korean Journal of Veterinary Service
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• v.26 no.4
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• pp.361-368
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• 2003

Sorbic acid and potassium sorbate are widely used food additives with high efficiancy and they are approved and recommended by FAO and WHO. Sorbic acid is one of preservatives that is mostly used in general food. Sorbic acid and potassium sorbate are used to prevent food, such as cheese, bread, beverage, and so on, from staling and molding. The world market for sorbic acid and potassium sorbate is growing and the market in Asian region is also expected to grow rapidly. This study was carried out to measure the amount of the sorbic acid in cooked meat produced from meat processing plants in Gyeongbuk province during 2000∼2003. One thousand one hundred and thirty-five samples of cooked meat(430 spices added meats, 486 grinding cooked meats, 3 bacons, 23 jerked meats, 68 sausages, 125 hams) were collected from meat processing plants and analyzed for the concentration of preservative sorbic acid by using of high performance liquid chromatography(HPLC). Sorbic acid was not detected in spices added meats, grinding cooked meats and bacons, except on jerked meats, ham and sausage. But the concentration range of sorbic acid in jerked meat was 0.00∼1.5g/kg, average 0.37g/kg, and in sausage was 0.00∼1.31g/kg, average 0.53g/kg, and in ham was 0.00∼ 1.22g/kg, average 0.56g/kg. There was no sample that sorbate concentration exceeded the legal permitted level 2.0g/kg in cooked meat.

• Journal of Environmental Impact Assessment
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• v.17 no.5
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• pp.263-270
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• 2008

The purpose of this study was to investigate the characteristics of the temple wastes and suggest the waste management guidelines for temples in natural parks. Study results revealed four important findings. First, it was found that the average quantity of the total temple wastes was 85,786g/day which was composed of general wastes(44,617g/day), food wastes(20,292g/day), recycling wastes(20.825g/day), and buddhist service wastes(60g/day). The average generation per capita of the temple wastes was 1,511g/capita day and the average bulk density was 0.102kg/l. Second, the food scrap was of small quantity(72.5g/day) because the traditional buddhist eating method, "Baru meal(鉢盂供養)" prohibits food abuse. This amount is very little compared to that produced in the general household in Korea. Third, the average quantity of the buddhist service wastes was 300-1,650g/one time. This wastes occupied 0.07% of the total temple wastes. Fourth, the average waste generated by visitors was 182.8g/person, which occupied 87.1% of the total temple wastes and costed 52,100,000 Wons to treat.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.214-221
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• 2011

Deoxynivalenol (DON) and zearalenone (ZEN) are mainly contaminated mycotoxins in feeds. The study was carried out to analyze and survey the contamination of DON and ZEN in one hundred thirteen samples of feeds. After cleaning all samples with immunoaffinity column, the mycotoxins were analysed by using high performance liquid chromatography/fluorescence with diode array detector (HPLC/FLD with DAD). The average recoveries of DON were 88.76 and 95.40% at the levels of 200 and 1,000 ${\mu}g/kg$ and 87.09 and 98.40% of ZEN were recovered at the levels of 100 and 500 ${\mu}g/kg$, respectively. The limit of detection (LOD) were 6.0 and 3.0 ${\mu}g/kg$ for DON and ZEN, respectively. The average concentrations of DON were 372.1, 324.0 and 990.9 ${\mu}g/kg$ in chicken, pig and cattle feed, respectively. Those of ZEN were 76.1, 43.7 and 196.2 ${\mu}g/kg$ for them, individually.

• Electronics and Telecommunications Trends
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• v.33 no.1
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• pp.111-122
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• 2018

In this review, several new technologies considered when providing an open service environment in a mobile communication network are described. Recently, 3GPP developed some standards related to IoT services for opening a service platform in an SCS environment based on the OSA concept in a 3GPP LTE system. Similarly, the development of a new framework is underway to allow a plurality of services to commonly use an API environment in which a service provider or client accesses a 5G mobile communication system. Extending the existing LTE SCEF concept, the standardization of the northbound API is applied in the 5G CAPIF environment. Therefore, it is possible to construct a framework that facilitates access from outside, and takes advantage of the common management of various open service environments. An open service platform environment is expected to play an important role in transforming a network with simple connectivity services into a variety of new service markets, or into a service environment that can create added value.