• Journal of Information Processing Systems
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• 제2권1호
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• pp.28-33
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• 2006

The initial research of Task Computing in the ubiquitous computing (UbiComp) environment revealed the need for access control of services. Context-awareness of service requests in ubiquitous computing necessitates a well-designed model to enable effective and adaptive invocation. However, nowadays little work is being undertaken on service access control under the UbiComp environment, which makes the exposed service suffer from the problem of ill-use. One of the research focuses is how to handle the access to the resources over the network. Policy-Based Access Control is an access control method. It adopts a security policy to evaluate requests for resources but has a light-weight combination of the resources. Motivated by the problem above, we propose a universal model and an algorithm to enhance service access control in UbiComp. We detail the architecture of the model and present the access control implementation.

• 한국전자거래학회지
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• 제16권1호
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• pp.71-100
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• 2011

IT 기술의 발전으로 시간적, 물리적 제약을 넘은 미래 인터넷 기술에 대한 사용자들의 기대가 커지고 있다. 이러한 요구를 충족시키기 위해 최근 새로운 개념으로 주목 받고 있는 것이 클라우드 컴퓨팅이다. 그러나 이러한 긍정적인 전망에도 불구하고 클라우드 컴퓨팅의 도입은 활발히 이루어지고 있지 않고 있는 실정이다. 따라서 본 연구에서는 클라우드 컴퓨팅 환경의 특성이 프로젝트 수행성과에 어떠한 영향을 미치는가에 대하여 살펴보았다. 본 연구는 기술적 도구로써 클라우드 컴퓨팅을 과업과 기술의 적합성 모형에 적용하여 클라우드 컴퓨팅 환경에서 개인이 프로젝트를 수행할 시에 나타나는 성과에 대하여 실증적인 연구를 하였다. 대학교 및 대학원에서 팀 단위의 프로젝트를 수행할 때, 클라우드 컴퓨팅의 가장 널리 보급된 형태인 GoogleDocs 및 웹하드에 대한 사용경험이 있는 응답자를 대상으로 설문을 수행하였다. 본 연구에서는 클라우드 컴퓨팅 환경에서 프로젝트를 수행한다는 행위에 중점을 두어, 접근성과 신뢰성을 적합성을 파악하기 위한 1차 요인으로 정의하여 프로젝트의 상호의존성과 개인의 특성이 적합성 및 활용을 통하여 성과에 어떤 영향을 미치는지를 분석하였다. 연구결과, 클라우드 컴퓨팅 환경은 팀 단위의 프로젝트 수행에 있어 적합한 도구라는 사실을 규명하였다. 본 연구는 초기단계의 클라우드 컴퓨팅에 있어 개인이 지각하는 적합성 및 성과를 규명함으로써, 협업에서의 클라우드 컴퓨팅의 긍정적인 영향에 대한 근거를 제시한다.

• 한국IT서비스학회지
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• 제14권2호
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• pp.253-273
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• 2015

Cloud computing is provided on demand service via the internet, allowing users to pay for the service they actually use. Categorized as one kind of cloud computing, SaaS is computing resource and software sharing model with can be accessed via the internet. Based on virtualization technology, SaaS is expected to improve the efficiency and quality of the IT service level and performance in company. Therefore this research limited cloud services to SaaS especially focused on collaborative application service, and attempts to identify the factors which impact the performance of collaboration and intention to use. This study adopts technological factors of cloud SaaS services and factors of task characteristics to explore the determinants of collaborative performance and intention to use. An experimental study using student subjects with Google Apps provided empirical validation for our proposed model. Based on 337 data collected from respondents, the major findings are following. First, the characteristics of cloud computing services such as collaboration support, service reliability, and ease of use have positive effects on perceived usefulness of collaborative application while accessability, service reliability, and ease to use have positive effects on intention to use. Second, task interdependence has a positive effects on collaborative performance while task ambiguity factor has not. Third, perceived usefulness of collaborative application have positive effects on intention to use.

• ETRI Journal
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• 제45권4호
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• pp.627-635
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• 2023

In vehicular edge computing (VEC) networks, the rapid expansion of intelligent transportation and the corresponding enormous numbers of tasks bring stringent requirements on timely task offloading. However, many tasks typically appear within a short period rather than arriving simultaneously, which makes it difficult to realize effective and efficient resource scheduling. In addition, some key information about tasks could be learned due to the regular data collection and uploading processes of sensors, which may contribute to developing effective offloading strategies. Thus, in this paper, we propose a model that considers the deterministic demand of multiple tasks. It is possible to generate effective resource reservations or early preparation decisions in offloading strategies if some feature information of the deterministic demand can be obtained in advance. We formulate our scenario as a 0-1 programming problem to minimize the average delay of tasks and transform it into a convex form. Finally, we proposed an efficient optimal offloading algorithm that uses the interior point method. Simulation results demonstrate that the proposed algorithm has great advantages in optimizing offloading utility.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권2호
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• pp.327-347
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• 2024

Edge computing is frequently employed in the Internet of Vehicles, although the computation and communication capabilities of roadside units with edge servers are limited. As a result, to perform distributed machine learning on resource-limited MEC systems, resources have to be allocated sensibly. This paper presents an Improved MADDPG algorithm to overcome the current IoV concerns of high delay and limited offloading utility. Firstly, we employ the MADDPG algorithm for task offloading. Secondly, the edge server aggregates the updated model and modifies the aggregation model parameters to achieve optimal policy learning. Finally, the new approach is contrasted with current reinforcement learning techniques. The simulation results show that compared with MADDPG and MAA2C algorithms, our algorithm improves offloading utility by 2% and 9%, and reduces delay by 29.6%.

• 한국멀티미디어학회논문지
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• 제7권5호
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• pp.755-765
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• 2004

최근에 많은 유휴 상태의 호스트 자원들을 이용한 인터넷 기반 분산/병렬 컴퓨팅은 대용량 작업처리와 여러 중요 논제들에 대해 그 유용성이 증명되고 있다. 대용량 작업이 수행되는 동안, 작업에 참여하는 호스트의 성능과 상태 변화에 대처하기 위한 실시간 모니터링 기능이 요구된다. 본 연구에서는 글로벌 컴퓨팅 (global computing) 인트라스트럭처(infrastructure)로 구축된 인터넷 기반 분산/병렬 처리 프레임워크인 PDP(Parallel Distributed Processing)상의 실시간 모니터링 및 시각화에 대한 내용을 소개한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.383-403
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• 2021

With the development of mobile edge computing (MEC), some late-model application technologies, such as self-driving, augmented reality (AR) and traffic perception, emerge as the times require. Nevertheless, the high-latency and low-reliability of the traditional cloud computing solutions are difficult to meet the requirement of growing smart cars (SCs) with computing-intensive applications. Hence, this paper studies an efficient offloading decision and resource allocation scheme in collaborative vehicular edge computing networks with multiple SCs and multiple MEC servers to reduce latency. To solve this problem with effect, we propose a context-aware offloading strategy based on differential evolution algorithm (DE) by considering vehicle mobility, roadside units (RSUs) coverage, vehicle priority. On this basis, an autoregressive integrated moving average (ARIMA) model is employed to predict idle computing resources according to the base station traffic in different periods. Simulation results demonstrate that the practical performance of the context-aware vehicular task offloading (CAVTO) optimization scheme could reduce the system delay significantly.

• Journal of Information Processing Systems
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• 제17권3호
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• pp.615-629
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• 2021

With the development of mobile edge computing, how to utilize the computing power of edge computing to effectively and efficiently offload data and to compute offloading is of great research value. This paper studies the computation offloading problem of multi-user and multi-server in mobile edge computing. Firstly, in order to minimize system energy consumption, the problem is modeled by considering the joint optimization of the offloading strategy and the wireless and computing resource allocation in a multi-user and multi-server scenario. Additionally, this paper explores the computation offloading scheme to optimize the overall cost. As the centralized optimization method is an NP problem, the game method is used to achieve effective computation offloading in a distributed manner. The decision problem of distributed computation offloading between the mobile equipment is modeled as a multi-user computation offloading game. There is a Nash equilibrium in this game, and it can be achieved by a limited number of iterations. Then, we propose a distributed computation offloading algorithm, which first calculates offloading weights, and then distributedly iterates by the time slot to update the computation offloading decision. Finally, the algorithm is verified by simulation experiments. Simulation results show that our proposed algorithm can achieve the balance by a limited number of iterations. At the same time, the algorithm outperforms several other advanced computation offloading algorithms in terms of the number of users and overall overheads for beneficial decision-making.

• International Journal of Computer Science & Network Security
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• 제23권1호
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• pp.140-146
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• 2023

Resource allocation is one of the top challenges in Internet of Things (IoT) networks. This is due to the scarcity of computing, energy and communication resources in IoT devices. As a result, IoT devices that are not using efficient algorithms for resource allocation may cause applications to fail and devices to get shut down. Owing to this challenge, this paper proposes a novel algorithm for managing computing resources in IoT network. The fog computing devices are placed near the network edge and IoT devices send their large tasks to them for computing. The goal of the algorithm is to conserve energy of both IoT nodes and the fog nodes such that all tasks are computed within a deadline. A bi-partite graph-based algorithm is proposed for stable matching of tasks and fog node computing units. The output of the algorithm is a stable mapping between the IoT tasks and fog computing units. Simulation results are conducted to evaluate the performance of the proposed algorithm which proves the improvement in terms of energy efficiency and task delay.

• 전자공학회논문지
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• 제54권5호
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• pp.48-61
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• 2017

클라우드 컴퓨팅의 IaaS 서비스는 유지비용 없이 원하는 만큼의 고성능 가상 머신을 사용할 수 있다는 장점 덕분에 대용량 병렬 프로그램을 실행하기 위한 고성능 컴퓨팅 환경으로 주목받고 있다. 이러한 고성능 컴퓨팅 환경에서 병렬 프로그램의 실행에 소요되는 시간은 태스크 스케줄링 알고리즘에 좌우된다. 클라우드 컴퓨팅 환경을 기반으로 하는 태스크 스케줄링 알고리즘에 관한 연구는 사용자 부담 비용을 최소화하는 알고리즘이 주류를 이루었으며, 병렬 프로그램의 실행을 최대한 빨리 끝내기 위한 알고리즘에 관한 연구는 거의 이루어지지 않았다. 본 논문에서는 사용자 부담 비용 등의 제약 없이 병렬 프로그램을 최대한 빨리 끝내기 위한 알고리즘인 HAGD 알고리즘과, HAGD 알고리즘이 사용하는 새로운 성능 향상 기법인 묶음 태스크 복제 기법을 제안한다. 묶음 태스크 복제 기법은 기존 태스크 복제 기법을 단순화하였으며, HAGD 알고리즘은 고성능 컴퓨팅 환경과 병렬 프로그램의 특성에 맞추어 태스크 삽입 기법 혹은 묶음 태스크 복제 기법을 사용한다. 성능 평가 결과, 제안하는 알고리즘이 환경 특성과 관계없이 우수한 표준화한 전체 실행 시간을 제공하는 것을 확인하였다.