• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.117-121
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• 2008

In ad hoc network, the scarce energy management of the mobile devices has become a critical issue in order to extend the network lifetime. Therefore, the energy consumption is important in the routing design, otherwise cluster schemes are efficient in energy conserving. For the above reasons, an Energy conserving Context aware Clustering algorithm (ECC) is proposed to establish the network clustering structure, and a routing algorithm is introduced to choose the Optimal Energy Routing Protocol (OERP) path in this paper. Because in ad hoc network, the topology, nodes residual energy and energy consuming rate are dynamic changing. The network system should react continuously and rapidly to the changing conditions, and make corresponding action according different conditions. So we use the context aware computing to actualize the cluster head node, the routing path choosing. In this paper, we consider a novel routing protocol using the cluster schemes to find the optimal energy routing path based on a special topology structure of Resilient Ontology Multicasting Routing Protocol (RODMRP). The RODMRP is one of the hierarchical ad hoc network structure which combines the advantage of the tree based and the mesh based network. This scheme divides the nodes in different level found on the node energy condition, and the clustering is established based on the levels. This protocol considered the residual energy of the nodes and the total consuming energy ratio on the routing path to get the energy efficiently routing. The proposed networks scheme could get better improve the awareness for data to achieve and performance on their clustering establishment and messages transmission. Also, by using the context aware computing, according to the condition and the rules defined, the sensor nodes could adjust their behaviors correspondingly to improve the network routing.

• 항공우주시스템공학회지
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• 제14권5호
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• pp.9-17
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• 2020

무인항공기를 비롯한 다수의 이동로봇은 제한된 연료로 임무를 수행하므로 장시간 운용시 효율을 극대화 하기위해 에너지를 고려한 경로계획이 요구된다. 본 연구에서는 3차원 환경에서 쿼드콥터 무인항공기 비행에 따른 소모 에너지를 근사화하여 기존 D^⁎ Lite 알고리즘의 비용함수에 적용하였다. 산업현장과 유사한 3차원 환경에서 시뮬레이션을 수행한 결과 에너지를 비용함수로 하고 휴리스틱 계산을 3 단순화 하였을 때 경로 생성 효율이 높았으며, 최단경로와 약 3.2% 이내의 차이를 갖는 경로를 최대 19.3배 빠르게 도출했다.

• 한국멀티미디어학회논문지
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• 제8권8호
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• pp.1108-1118
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• 2005

Ad Hoc 네트워크는 무선접속을 사용하는 이동 노드들이 중앙관리 없이 구성되는 네트워크이다. Ad Hoc 네트워크의 노드는 제한된 전원을 가지며, 따라서 효율적으로 에너지를 사용하는 라우팅 방식에 대한 연구가 필요하다. 기존의 석유 에너지 기반 라우팅은 특정 노드의 과도한 에너지 소모에 따른 노드들간의 공정성, 네트워크 전체의 과도한 에너지 소비 등의 문제점을 가지고 있다. 본 논문에서는 기존의 문제점을 개선할 수 있는 Clustering Based Energy-Aware Routing (CBEAR) 방식을 제안하였다. 성능분석 결과 제안된 방식은 노드의 생존성을 유지하면서 노드들간의 공정성과 네트워크 전체의 에너지 효율성을 개선함을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.571-573
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• 2009

이동 애드혹 네트워크(MANET)는 무선네트워크에서 노드들이 제한적인 에너지를 가지고 있기 때문에 보다 효율적인 노드의 관리가 요구 된다. 이러한 MANET에서는 정적인 네트워크에 비해 토폴로지가 자주 변하므로 이동성을 고려한 에너지 효율적인 라우팅 프로토콜이 요구된다. 기존에 제안 된 CACH(Context-aware Adaptive Clustering Hierarchy)[1]는 하이브리드 라우팅 방식을 분산 클러스터링 기반으로 구성하여 네트워크 수명을 연장하고 지연시간을 감소하였다. 하지만 노드의 밀도증가를 효율적으로 알고리즘에 적용하지 못한 문제점이 있다. 이를 보완하기 위해 본 논문에서는, CACHE(Context-aware Adaptive Clustering Hierarchy and Energy efficient)를 제안한다. CACHE는 노드 밀도 변경에 대해 적응적으로 알고리즘을 적용할 수 있도록 클러스터 구성을 수정하여, CACH가 갖는 노드 밀도 문제를 개선하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권2호
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• pp.80-84
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• 2009

Dynamic voltage and frequency scaling (DVFS) is an effective method to achieve low power design. In our work, we present an analytical DVFS method which judiciously exploits correlation information in runtime distribution while satisfying deadline constraints. The proposed method overcomes the previous distribution-aware DVFS method [2] which has pessimistic assumption on which runtime distributions are independent. Experimental results show the correlation-aware DVFS offers 13.3% energy reduction compared to existing distribution-aware DVFS [2].

• Journal of Computing Science and Engineering
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• 제7권1호
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• pp.30-43
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• 2013

Multicore and multiprocessor systems with dynamic voltage scaling architectures are being used as one of the solutions to satisfy the growing needs of high performance applications with low power constraints. An important aspect that has propelled this solution is effective task/application scheduling and mapping algorithms for multiprocessor systems. This work proposes an energy aware, offline, probability-based unified scheduling and mapping algorithm for multiprocessor systems, to minimize the number of processors used, maximize the utilization of the processors, and optimize the energy consumption of the multiprocessor system. The proposed algorithm is implemented, simulated and evaluated with synthetic task graphs, and compared with classical scheduling algorithms for the number of processors required, utilization of processors, and energy consumed by the processors for execution of the application task graphs.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.987-992
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• 2016

This study introduces an example environment where wireless devices are mobile, devices use dynamic voltage scaling, devices and tasks are heterogeneous, tasks have deadline, and the computation and communication power is dynamically changed for energy saving. For this type of environment, the efficient system-level energy management and resource management for task completion can be an essential part of the operation and design of such systems. Therefore, the resources are assigned to tasks and the tasks may be scheduled to maximize a goal which is to minimize energy usage while trying to complete as many tasks as possible by their deadlines. This paper also introduces mobility of nodes and variable transmission power for communication which complicates the resource management/task scheduling problem further.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.92-96
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• 2011

Nowadays, the researches study high rate and real-time query applications seem to be real-time query scheduling protocols and energy aware real time query protocols. Also the WSNs should provide the quality of data in real time query applications that is more and more popular for wireless sensor networks (WSNs). Thus we propose the quality of data function to merge into energy efficiency called energy join quality aware realtime query scheduling (EJQRTQ). Our work calculate the energy ratio that considers interference of queries, and then compute the expected quality of query and allocate slots to real-time preemptive query scheduler.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.35-35
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• 2004

• ETRI Journal
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• 제44권5호
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• pp.746-758
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• 2022

This paper focuses on a mobile edge-computing-enabled heterogeneous network. A battery level-aware task-scheduling framework is proposed to improve the energy efficiency and prolong the operating hours of battery-powered mobile devices. The formulated optimization problem is a typical mixed-integer nonlinear programming problem. To solve this nondeterministic polynomial (NP)-hard problem, a decomposition-based task-scheduling algorithm is proposed. Using an alternating optimization technology, the original problem is divided into three subproblems. In the outer loop, task offloading decisions are yielded using a pruning search algorithm for the task offloading subproblem. In the inner loop, closed-form solutions for computational resource allocation subproblems are derived using the Lagrangian multiplier method. Then, it is proven that the transmitted power-allocation subproblem is a unimodal problem; this subproblem is solved using a gradient-based bisection search algorithm. The simulation results demonstrate that the proposed framework achieves better energy efficiency than other frameworks. Additionally, the impact of the battery level-aware scheme on the operating hours of battery-powered mobile devices is also investigated.