• Electronics and Telecommunications Trends
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• v.18 no.2 s.80
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• pp.11-24
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• 2003

이동 Ad Hoc 네트워크는 고정적이고 계층적인 인프라스트럭처 네트워크와는 비교되는, 이동 노드만으로 구성된 자율적이고 수평적인 네트워크이다. 이동 Ad Hoc 네트워크의 이동 노드는 중재자의 도움 없이 능동적인 연결 설정이 가능하고 네트워크의 참여 또는 이탈이 자유로우며 에너지원의 공급이 제한되어 빈번하게 네트워크의 토폴로지를 변화시킨다. 이러한 망의 특성상 이동 Ad Hoc 네트워크 기술은 하위 계층의 전파 전파, 전파 간섭 및 전력 제어에서부터 링크 계층의 다중 접속 및 자원 할당, 네트워크 계층의 라우팅, 트랜스포트 계층의 연결 설정 및 유지, 그리고 보안 및 상위 계층 애플리케이션에 이르기까지 다양한 기술적 해결 요구사항을 갖는다. 본 고에서는 이러한 Ad Hoc 네트워크의 특징과 특성을 살펴보고 관련 주요 요소 기술과 과거부터 현재까지 이동 Ad Hoc 네트워크 기술 분야에서 진행되어온 연구동향을 살펴본다.

• Electronics and Telecommunications Trends
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• v.30 no.1
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• pp.102-113
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• 2015

급증하는 모바일 트래픽 용량에 대처하고 사용자의 QoS(Quality of Service)를 만족시킬 수 있는 기술 중 하나로 단위면적당 용량 증대에 기여할 수 있는 소형셀 기술이 부각되고 있다. 소형셀 기지국 기술은 3G, 4G 이동통신시스템에서는 셀의 소형화를 통한 용량 증대, 음영지역 해소를 위하여 사용되고 있으며, 5G 이동통신에서는 보다 밀집한 셀의 구성 및 셀 소형화를 통한 용량증대 기술로 UDN(Ultra Dense Network) 분야와 연계되어 연구 중이다. 본고에서는 소형셀 기지국 주요 기술분석을 통하여 상용 소형셀 기지국의 개발 접근방법을 제시하고, 소형셀 표준화 동향을 통한 소형셀 기지국 진화방향을 알아본다. 또한, 소형셀 기지국 기술 시장 동향분석으로 국내 및 글로벌 시장의 규모를 파악하여 향후 5G 이동통신에서의 소형셀 기술의 나아가야 하는 방향을 제시하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.66-69
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• 2011

Many international organizations build a global communications network called the GMDSS by close cooperation, and ITU-R, IMO and IEC apply it for the modernization of the international marine radiocommunication system, but a modernization study of the GMDSS to reflect such a technique by the rapidly development of the wireless communication technology recently progresses. Such effort was submitted for adoption with WRC-12 held in 2012. This paper analyzed standardization trends for marine radiocommunication modernization discussed around ITU-R recently and analyzed research activities for frequency allocation for new technical introduction and described it.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.798-800
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• 2003

Recently, in optical storage device technical trends, the size of optical drive is slimmer to adopt notebook computer and the power of actuator is higher to achieve the high transfer rate. However, these trends of optical disc drives tend to increase the temperature of the actuator part, it causes some problems on the performance of optical parts - the resonance frequency of the actuator is down to lower band and the objective lens, coil and magnet are easily damaged. In this study, to overcome these thermal problems, the numerical simulations of heat transfer were performed. As the result of simulations, the thermal characteristic of the hybrid actuator is better than the previous design. And, it shows the good dynamic performance in experiment.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.42-50
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• 2019

The fifth generation (5G) wireless technology is expected to be the trigger for the fourth industrial revolution. In particular, 5G ultra reliable low latency communication (URLLC) is expected to lead the wireless automation in vertical domains. In this paper, we analyze use cases, key metrics, and physical layer technologies for 5G URLLC standardized in $3^{rd}$ Generation Partnership Project Radio Access Network (3GPP RAN). Additionally, we discuss enabling RAN technologies towards beyond 5G to support high reliability and low latency.

• Electronics and Telecommunications Trends
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• v.34 no.4
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• pp.98-107
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• 2019

This article examines the technical trends of recent logistics and delivery robots. Since the commencement of the $4^{th}$ industrial revolution, logistics robots and delivery robots have gained considerable attention from the public and the market owing to advances in artificial intelligence and information and communication technology. This article reviews logistics and delivery robots from the perspectives of the market and academia. In addition, we summarize difficulties that they currently face and enumerate further work for their success in the market.

• 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.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.81-93
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• 2018

Metamaterials are artificial media that can control the properties of waves at will. Active photonic metadevice technologies cover the device and material technologies that control the visible and IR light through an external signal (mainly an electrical signal). The application areas of active photonic metadevices are tremendous for example holography, active HOE, bio imaging, IR imaging, telecommunication, and optoelectronic devices. In this paper, the technical trends and prospects of active metamaterials, active meta holography, active meta devices, nano-optical telecommunication devices, and IR imaging meta devices are reviewed.

• Electronics and Telecommunications Trends
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• v.36 no.4
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• pp.145-153
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• 2021

Data imputation is a crucial issue in data analysis because quality data are highly correlated with the performance of AI models. Particularly, it is difficult to collect quality time-series data for uncertain situations (for example, electricity blackout, delays for network conditions). Thus, it is necessary to research effective methods of time-series data imputation. Many studies on time-series data imputation can be divided into 5 parts, including statistical based, matrix-based, regression-based, deep learning (RNN and GAN) based methodologies. This study reviews and organizes these methodologies. Recently, deep learning-based imputation methods are developed and show excellent performance. However, it is associated to some computational problems that make it difficult to use in real-time system. Thus, the direction of future work is to develop low computational but high-performance imputation methods for application in the real field.

• Electronics and Telecommunications Trends
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• v.36 no.2
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• pp.65-74
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• 2021

In this paper, we discussed the necessity and importance of introducing feature stores to establish a collaborative environment between data engineering work and data science work. We examined the technology trends of feature stores by analyzing the status of some major feature stores. Moreover, by introducing a feature store, we can reduce the cost of performing artificial intelligence (AI) projects and improve the performance and reliability of AI models and the convenience of model operation. The future task is to establish technical requirements for establishing a collaborative environment between data engineering work and data science work and develop a solution for providing a collaborative environment based on this.