• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.4061-4076
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• 2017

With the development of high-speed railway technologies, train velocities can now reach speeds up to 350 km/h, and higher in the future. In high-speed railway systems (HSRs), loss of communication can result in serious accidents, especially when the train is controlled through wireless communications. For to this reason, operators of Long Term Evolution for Railway (LTE-R) communication systems install eNodeBs (eNBs) with high density to achieve highly reliable communications. However, densely located eNBs can result in unnecessary frequent handovers (HOs) resulting in instability because, during every HO process, there is a period of time in which the communication link is disconnected. To solve this problem, in this paper, an HO scheme based on the maximum cell residence time (CRT) and adaptive time to trigger (aTTT), which are collectively called CaT, is proposed to reduce unnecessary HOs (using CRT estimations) and decrease HO failures by improving the handover command transmission point (HCTP) in LTE-R HSR communications.

• Information and Communications Magazine
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• v.27 no.5
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• pp.30-35
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• 2010

인터넷의 발전 과정에서 데이터 중심의 시맨틱 웹 기술과 서비스 중심의 웹 서비스 기술은 시맨틱 웹 서비스라는 융합기술로 발전하고 있다. 본 고에서는 시맨틱 웹 서비스의 핵심 기술인 어노테이션, 발견, 조합, 실행, 중재 기술에 대해 소개하고, 산업계와 학계의 연구 동향을 분석한다. 더불어 시맨틱 웹 서비스 기술이 융복한 서비스 발전에 미치는 영향을 간략히 고찰하고자 한다.

• ETRI Journal
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• v.29 no.4
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• pp.477-488
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• 2007

In recent years, numerous studies have identified and explored issues related to web-service-oriented business process specifications, such as business process execution language (BPEL). In particular, business rules are an important cross-cutting concern that should be distinguished from business process instances. In this paper, we present a rule-based aspect oriented programming (AOP) framework where business rule aspects contained in business processes can be effectively separated and executed. This is achieved by using a mechanism of the business rule itself at the business rule engine instead of using existing programming language-based AOP technologies. Through some illustrative examples, this work also introduces a method by which business rule aspects, separated through an external rule engine, can be represented and evaluated. We also demonstrate how they can be dynamically woven and executed by providing an implementation example which uses two open-source-based products, the Mandarax rules engine and Bexee BPEL engine.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5299-5320
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• 2019

Interest in self-driving vehicle research has been rapidly increasing, and related research has been continuously conducted. In such a fast-paced self-driving vehicle research area, the development of advanced technology for better convenience safety, and efficiency in road and transportation systems is expected. Here, we investigate research in self-driving vehicles and analyze the main technologies of driverless car software, including: technical aspects of autonomous vehicles, traffic infrastructure and its communications, research techniques with vision recognition, deep leaning algorithms, localization methods, existing problems, and future development directions. First, we introduce intelligent self-driving car and road infrastructure algorithms such as machine learning, image processing methods, and localizations. Second, we examine the intelligent technologies used in self-driving car projects, autonomous vehicles equipped with multiple sensors, and interactions with transport infrastructure. Finally, we highlight the future direction and challenges of self-driving vehicle transportation systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.10
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• pp.1355-1360
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• 2018

The healthcare industry is expected to the range of services will be expanded and management will be done throughout the life cycle by combining Big Data, Information and Communications Technologies (ICT), and IT equipment. This paper describes a metacarpophalangeal joint flexion and interphalangeal joint flexion of the thumb as one area of healthcare. Metacarpophalangeal joint flexion refers to bending the thumb metacarpophalangeal joint, and interphalangeal joint flexion refers to bending the thumb interphalangeal joint. When bending the joints, if the angle is below a certain angle, or if you feel pain, you have an abnormality. In addition, prevention and therapy of the thumb joint were also suggested. Experiments were performed on metacarpophalangeal joint flexion and interphalangeal joint flexion in the thumb joint in the case of 50 people in their 50s. The system is limited to a portion of the body, but if it is partially expanded, it will be the basis for building a Big Data healthcare system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1933-1941
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• 2016

This paper compares the performance of wireless communication technologies to replace the wired networks by wireless networks on avionics intra-communication. Due to the drawbacks of wired network, such as complexity, weight, maintenance cost and scalability, it leads to the high data rate and network traffic demands of avionics systems. Therefore, in WAIC(Wireless Avionics Intra-Communications) system suggested by ITU(International Telecommunication Union), based on environment of avionics system and requirements of a wired network, wireless network structures are defined to solve the problems of wired networks. In this paper, we consider features, advantages and disadvantages of wireless communication technologies which can be used for wireless avionics network, and we propose suitable wireless communication technology candidates for wireless avionics networks in WAIC environments.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.35 no.7
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• pp.9-25
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• 2017

In this paper, we surveyed state-of-the-art health and wellness platforms. The motivation of this paper is to review the state-of-the-art health and wellness platforms and their maturity with respect to adoption of latest enabling technologies. The is review is classified into four categories: healthcare systems, AI-assisted healthcare, wellness platforms, and open source health and wellness initiatives. From this comprehensive review, it can be stated that the contemporary healthcare systems are well-adopting wellness due to the concentration shift towards prevention. Thus, the gap between health and wellness is slowly yet carefully entering gray area. Where both the domains can freely invoke each other's services, and supporting enabling technologies. Furthermore, the biomedical researchers and physicians are no longer carrying the myopic views of trusting their knowledge for diagnosis. AI-assisted technologies based on machine learning and big data are influencing today's prognosis with trust and confidence.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8B
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• pp.615-623
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• 2008

Wireless LAN (WLAN) has greatly benefited from the introduction of various technologies, such as MAC protocol and scheduling algorithm. The majority of these technologies focus on fairness or service differentiation. However, it is difficult to use these technologies to provide many benefits to WLAN simultaneously because the current WLAN system only focuses on the provision of a single aspect of QoS. Unfortunately, multimedia applications require both service differentiation and fairness. Therefore, this paper combines Distributed Fair Scheduling (DFS) and Enhanced Distributed Coordinate Function (EDCF), to provide both fairness and service differentiation simultaneously. Furthermore, we show numerical analysis using Markov process. The simulation results demonstrate that F-EDCF outperforms the EDCF, in terms of throughput, fairness, and delay viewpoints.

• ETRI Journal
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• v.30 no.1
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• pp.164-166
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• 2008

This paper proposes a priority-based duplicate burst transmission mechanism in an optical burst switching network to enhance the probability of successful reception of bursts. The performance of the proposed mechanism is evaluated by NS2 simulations. Our results show that the burst loss rate is improved especially under light traffic loads.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2806-2818
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• 1997

It is generallyaccepted that broadband access technologies will play an important role in the National Information Infrastructure. However, the provision of direct fibers to residential and small business customers has always been considered a challenge. To accelerage the provision of Broadband Access Facilities, alternatibe paths could be identified and actaivated in parallel. In this paepr, we present an overview of the alternative access technologies focusing on xDSL, FTTx, HFC, HFR, and suggest the modeling of the access netetwork systems which is using of the technologies. Also to investigate the economics of each access systems, we derve the numerical equations which is summed up the al parameter including the labor cost of the model system. The proposed equation has a variable which is the cell size (or subsciber clusters) and calculate the real cost values which is normalized by the copper cable unit cost. From the numerical resutls, we conclude that the economic access method to provide these broadband capabilities is depended on the subscriber penetration, the patterns of subscriber distribution density and existing communication infrastructures. It can be expected that our analytical model and equations provides an elegant solution to choose the optimal broadband access technologies to residential and small business customers.