• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.188-210
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• 2022

As a promising technique to support tremendous numbers of Internet of Things devices and a variety of applications efficiently, mobile edge computing (MEC) has attracted extensive studies recently. In this paper, we consider a MEC-assisted peer-to-peer (P2P) mobile communication system where MEC servers are deployed at access points to accelerate the communication process between mobile terminals. To capture the tradeoff between the time delay and the energy consumption of the system, a cost function is introduced to facilitate the optimization of the computation and communication resources. The formulated optimization problem is non-convex and is tackled by an iterative block coordinate descent algorithm that decouples the original optimization problem into two subproblems and alternately optimizes the computation and communication resources. Moreover, the MEC-assisted P2P communication system is compared with the conventional P2P communication system, then a condition is provided in closed-form expression when the MEC-assisted P2P communication system performs better. Simulation results show that the advantage of this system is enhanced when the computing capability of the receiver increases whereas it is reduced when the computing capability of the transmitter increases. In addition, the performance of this system is significantly improved when the signal-to-noise ratio of hop-1 exceeds that of hop-2.

• 사물인터넷융복합논문지
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• 제9권1호
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• pp.125-129
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• 2023

최근 Internet of Things (IoT) 기반 Wireless Networked Control System (WNCS)에서 Sensor의 Status Update 및 Actuator로의 Actuation Update 분석을 위해 정보의 신선도를 측정하는 지표인 Age of Information (AoI)가 고려되고 있다. 또한 WNCS에 Edge Computing (EC)이 도입되면서 기존의 Cloud Computing 기반 아키텍처보다 낮은 AoI를 보장할 수 있다. 하지만 Controller가 관리하는 Sensor의 수가 증가하면서 Controller에 부하가 증가하여 AoI 요구사항을 만족시키지 못하는 문제점이 발생하게 되었다. 본 연구에서는 이러한 문제를 해결하기 위해 Actuator의 컴퓨팅 능력을 활용하여 Sensor의 Status Update를 해당 지역의 Actuator가 가용할 때 직접적으로 전송하여 Actuator가 직접 Actuation Update를 수행함으로써 AoI 요구사항을 만족시키고자 한다. 이를 위해 본 연구에서는 AoI 분석을 위한 분석 모델을 제시하였고 시뮬레이션을 통해 제안하는 방법이 기존 방법 대비 AoI를 줄일 수 있음을 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권4호
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• pp.1147-1161
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• 2023

The Internet of Things (IoT) requires a new processing model that will allow scalability in cloud computing while reducing time delay caused by data transmission within a network. Such a model can be achieved by using resources that are closer to the user, i.e., by relying on edge computing (EC). The amount of IoT data also grows with an increase in the number of IoT devices. However, building such a flexible model within a heterogeneous environment is difficult in terms of resources. Moreover, the increasing demand for IoT services necessitates shortening time delay and response time by achieving effective load balancing. IoT devices are expected to generate huge amounts of data within a short amount of time. They will be dynamically deployed, and IoT services will be provided to EC devices or cloud servers to minimize resource costs while meeting the latency and quality of service (QoS) constraints of IoT applications when IoT devices are at the endpoint. EC is an emerging solution to the data processing problem in IoT. In this study, we improve the load balancing process and distribute resources fairly to tasks, which, in turn, will improve QoS in cloud and reduce processing time, and consequently, response time.

• 한국멀티미디어학회논문지
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• 제17권3호
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• pp.353-363
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• 2014

Cloud computing is an internet-based technology, providing services to the virtualized IT environment, and allowing users to add or remove resources of hardware or software at their discretion. Since Cloud computing can construct virtually integrated environments out of multiple local computing environments, various information services can be provided by it. In addition, state organizations also strive to build the cloud computing environments due to the benefits of reduced costs to introduce the system and of reduced time to build and provide the IT services. This study suggests a web-based cloud computing system for the computing environments, to be applied for the Korean National Health and Nutrition Examination Survey (KNHANES) by the Ministry of Health and Welfare, Republic of Korea.

• 디지털콘텐츠학회 논문지
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• 제12권3호
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• pp.319-327
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• 2011

클라우드 컴퓨팅은 인터넷상에 기업이나 소비자들에게 IT서비스를 제공하기 위한 유연하고 비용 효과적인 검증된 전송 플랫폼으로, 계산이나 데이터가 데스크탑이나 포터블 PC로부터 대규모 데이터센터로 이동하는 계기가 되었다. 이와 같은 클라우드 컴퓨팅 서비스의 활성화를 위해서는 현재 제공되거나 향후 제공될 서비스가 현재와 미래의 고객을 만족시키기 위해 개선되어야 할 서비스 품질요건에 대한 분석이 필수적이다. 본 연구는 클라우드 서비스 환경에서 서비스품질 규명을 위한 연구의 일환으로서, 탐색적 방법을 사용하여 기존 다양한 문헌을 분석하였으며, 이로부터 7가지의 클라우드 컴퓨팅의 서비스 특성과 세부속성들을 정의하였다.

• 한국멀티미디어학회논문지
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• 제24권1호
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• pp.51-57
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• 2021

In this paper, we propose a task distribution scheme in fog computing environment considering opportunistic fog computing nodes. As latency is one of the important performance metric for IoT(Internet of Things) applications, there have been lots of researches on the fog computing system. However, since the load can be concentrated to the specific fog computing nodes due to the spatial and temporal IoT characteristics, the load distribution should be considered to prevent the performance degradation. Therefore, this paper proposes a task distribution scheme which considers the static as well as opportunistic fog computing nodes according to their mobility feature. Especially, based on the task requirements, the proposed scheme supports the delay sensitive task processing at the static fog node and delay in-sensitive tasks by means of the opportunistic fog nodes for the task distribution. Based on the performance evaluation, the proposed scheme shows low service response time compared to the conventional schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2761-2781
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• 2018

With the continuous growth of data size and the use of compression technology, data reduction has great research value and practical significance. Aiming at the shortcomings of the existing semantic compression algorithm, this paper is based on the analysis of ItCompress algorithm, and designs a method of bidirectional order selection based on interval partitioning, which named An Optimized Iterative Semantic Compression Algorithm (Optimized ItCompress Algorithm). In order to further improve the speed of the algorithm, we propose a parallel optimization iterative semantic compression algorithm using GPU (POICAG) and an optimized iterative semantic compression algorithm using Spark (DOICAS). A lot of valid experiments are carried out on four kinds of datasets, which fully verified the efficiency of the proposed algorithm.

• 인터넷정보학회논문지
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• 제17권4호
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• pp.173-180
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• 2016

SOA has been adopted by enormous number of organizations world-wide. This study has investigated significant factors which affect SOA adoption in positive and negative manner. Unlike the previous similar studies, where they focused on qualitative analysis for SOA adoption, this study conducted a quantitative analysis to investigate the relationship between the adoption of SOA and the performance of IT organizations. In order to conduct the research, an online questionnaire was created and distributed among SOA experts through the social networking platform of professionals, LinkedIn. Total one hundred and four (104) respondents from thirty (30) different countries participated in this study. The results of this study indicate that there are both positive and negative influences upon SOA adoption. The positive influences includes: governance, strategy, culture and communication, business and IT alignment and ROI; whereas complexity, security concerns, and costs have negatively affected SOA adoption.

• 인터넷정보학회논문지
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• 제8권5호
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• pp.109-116
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• 2007

요즈음, 웹 서비스의 확산으로 인하여, 등록된 웹 서비스를 합성함으로써 복잡한 응용프로그램을 구축하는 것이 가능하다. 이러한 추세는 오늘날 서비스 지향의 컴퓨팅 환경에 있어서 합성된 웹 서비스의 서비스 품질 보장을 중요한 문제로 대두시키고 있다. 하지만 주어진 서비스 품질 보장을 만족하는 전역적 최적화된 웹 서비스의 합성은 NP-hard한 문제로 분류된다. 본 논문에서는 이러한 문제를 해결하기 위하여, K-way Super node 접근법을 제시하고 실험 결과를 통하여 이의 효과를 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권7호
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• pp.1569-1584
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• 2013

Ubiquitous interaction in a pervasive environment is the main attribute of smart spaces. Pervasive systems are weaving themselves in our daily life, making it possible to collect user information invisibly, in an unobtrusive manner by known and even unknown parties. Huge number of interactions between users and pervasive devices necessitate a comprehensive trust model which unifies different trust factors like context, recommendation, and history to calculate the trust level of each party precisely. Trusted computing enables effective solutions to verify the trustworthiness of computing platforms. In this paper, we elaborate Unified Trust Model (UTM) which calculates entity's trustworthiness based on history, recommendation, context and platform integrity measurement, and formally use these factors in trustworthiness calculation. We evaluate UTM behaviour by simulating in different scenario experiments using a Trust and Reputation Models Simulator for Wireless Sensor Networks. We show that UTM offers responsive behaviour and can be used effectively in the low interaction environments.