• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.8-15
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• 2022

The new 5G radio technology (NR) can provide ultra-reliable low latency communications. The supporting 5G network infrastructure will move away from the previous point-to-point network architecture to a service-based architecture. 5G can provide three new things, i.e., wider channels, lower latency and more bandwidth. These will allow 5G to support three main types of connected services, including enhanced mobile broadband, mission-critical communications, and the massive Internet of Things (IoT). In 2015, the 5th generation (5G) mobile communication was officially approved by the International Telecommunication Union (ITU) as IMT-2020. Since then, 3GPP, the international organization responsible for 5G standards, is actively developing specifications for 5G technologies. 3GPP Release 15 provides the first full set of 5G standards, and the evolution and expansion of 5G are now being standardized in Release 16 and 17, respectively. This paper provides an overview of 3GPP 5G technologies and key services.

• 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.

• Electronics and Telecommunications Trends
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• v.32 no.3
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• pp.68-77
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• 2017

5G 이동통신은 4세대 LTE보다 전송속도는 270배 빠르고, 지연시간은 1/30에 불과 할 정도로 빠른 속도와 연결성을 제공하기 때문에 가상현실, 증강현실, 자율주행차 등의 새로운 서비스를 구현할 수 있다. 5G 이동통신이 미래 유망 서비스로 부각되자 이동통신사들은 노키아, 에릭슨, 화웨이, 삼성전자 등 글로벌 장비업체들과 제휴하여 2019~2020년 상용화를 목표로 5G 기술개발에 박차를 가하고 있다. 일본의 NTT도코모, 중국의 차이나모바일, 한국의 KT, SK텔레콤 등 동북아 3국의 통신사업자들이 정부 전략과 공조하면서 가장 앞서 나가고 있다.

• The Journal of Society for e-Business Studies
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• v.25 no.1
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• pp.135-176
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• 2020

This study is to investigate the factors affecting the usage intentions of 5G service between 5G service subscribers and non-subscribers based on the Integratively Extended Technology Acceptance Model in the initial B2C 5G service market. We designed the integratively extended technology acceptance model to find the more specific factors to affect the usage intentions by integrating the exogenous factors including the technical factors, the social factors, and the personal factors with the ETAM(Extended Technology Acceptance Model). Referring to the previous studies, we constructed the hypotheses of structural influence relationship from the exogenous factors to the dependent usage intentions factors through the mediating belief factors. We designed the 5G service usage intentions model based on these hypotheses and operational definitions of the factors. Using the analysis of SEM(Structural Equation Model), the proposed model and the hypotheses were empirically tested by the data collected from 245 subscribed respondents and 245 non-subscribed respondents. As a result, the perceived ease of use has an effect on the perceived usefulness and enjoyment, and the perceived usefulness/enjoyment and the personal innovativeness have positive effects on the usage intentions of both groups.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.25-33
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• 2008

Video telephony is a representative service in 3G mobile network. And there have been efforts to improve quality of video telephony service in different fields. In Korea, the leading mobile service provider SKTelecom and KTF service the WCDMA network as 3G mobile network. Now, more than a million people is using the network. In this paper, we study about video telephony over WCDMA network. and propose error minimizing algorithm using cross-layer adaptation between physical layer and video codec. We simulated 3G-324M protocol with MPEG-4 video codec, and simulation results show suggested algorithm improve packet transmission rate for improving quality of video telephony service.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.109-117
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• 2020

In this paper, we analyze LADN(Local Area Data Network) that provides high throughput, low latency and service localization for 5G wireless networks and propose an enhanced control protocol design for LADN in 5G wireless networks. The concept of LADN is newly introduced in 3GPP 5G communication system and the LADN is a data network to which the UE(User Equipment) can connect with a specific LADN session only when the UE is located in a certain service area. If the LADN information between the UE and core network is not identical, the LADN session cannot be properly established. The proposed approach promplty synchronizes the LADN information between the UE and core network by using the specific registration procedure and appropriately establishes the LADN session, when the establishment of the LADN session is failed. Consequently, the proposed enhanced control protocol design(ECP) can prevent unnecessary signalling overhead and communication delay for LADN in 5G wireless networks.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.669-670
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• 2020

기존 유선망 중심의 스마트시티 플랫폼과 달리 무선 통신 모듈을 가지고 있는 정보 수집 장치들과 연동할 수 있는 5G 스마트시티 융합서비스 플랫폼은 도시내 설치된 다양한 무선 정보 수집 장치들을 통하여 수집된 정보를 기반으로 분석된 각종 정보를 제공해 주는 시스템이다. 도시 정보 수집 장치들 중에는 5G 지능형 CCTV 가 있으며 이를 통해 수집되는 영상 이벤트 정보를 기반으로 도로 안전 서비스 제공을 위한 이벤트 수집/필터링/대응 기능을 통하여 도로 안전 서비스를 제공해 주는 시스템을 설계하고 개발하여 적용함으로써, 도시내 도로 안전 수준을 높이는 것으로 목적으로 하고 있다. 본 논문에서는 도로 안전 서비스 제공을 위한 기능 모듈 구성에 대해 기술하고 해당 모듈들을 통하여 제공되는 도로 안전 서비스 실증 사례를 제시하고자 한다.

• ETRI Journal
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• v.40 no.1
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• pp.26-38
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• 2018

To overcome considerable path loss in millimeter-wave propagation, high-gain directional beamforming is considered to be a key enabling technology for outdoor 5G mobile networks. Associated with beamforming, this paper investigates propagation power loss characteristics in two aspects. The first is beamwidth effects. Owing to the multipath receiving nature of mobile environments, it is expected that a narrower beamwidth antenna will capture fewer multipath signals, while increasing directivity gain. If we normalize the directivity gain, this narrow-beamwidth reception incurs an additional power loss compared to omnidirectional-antenna power reception. With measurement data collected in an urban area at 28 GHz and 38 GHz, we illustrate the amount of these additional propagation losses as a function of the half-power beamwidth. Secondly, we investigate power losses due to steering beam misalignment, as well as the measurement data. The results show that a small angle misalignment can cause a large power loss. Considering that most standard documents provide omnidirectional antenna path loss characteristics, these results are expected to contribute to mmWave mobile system designs.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.353-358
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• 2001

Sorbic acid is one of preservatives that is mostly used in general food. This study was carried out to measure the amount of the sorbic acid in cooked meat produced from meat processing plants in Gyeongbuk province. One hundred and fifty-three samples of cooked meat(42 spices added meats, 56 grinding cooked meats, 2 bacons, 5 jerked meats, 18 sausages, 30 hams) were collected from meat processing plants and analyzed for the concentration of preservative sorbic acid and its salts by using of high performance liquid chromatography(HPLC). Sorbic acid was not detected in spices added meats, grinding cooked meats, bacons, and jerked meats except on ham and sausage. But the concentration range of sorbic acid in sausage was 0.00～1.31g/kg, average 0.44g/kg, and in ham was 0.00～1.31g/kg, average 0.329/kg. There was no sample that sorbate concentration exceeded the legal permitted level 2.0g/kg in cooked meat.

• ETRI Journal
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• v.40 no.1
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• pp.7-9
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• 2018