• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4320-4333
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• 2017

Energy-efficient virtual resource allocation algorithm has become a hot research topic in cloud computing. However, most of the existing allocation schemes cannot ensure each type of resource be fully utilized. To solve the problem, this paper proposes a virtual machine (VM) allocation algorithm on the basis of multi-dimensional resource, considering the diversity of user's requests. First, we analyze the usage of each dimension resource of physical machines (PMs) and build a D-dimensional resource state model. Second, we introduce an energy-resource state metric (PAR) and then propose an energy-aware multi-dimensional resource allocation algorithm called MRBEA to allocate resources according to the resource state and energy consumption of PMs. Third, we validate the effectiveness of the proposed algorithm by real-world datasets. Experimental results show that MRBEA has a better performance in terms of energy consumption, SLA violations and the number of VM migrations.

• The Korean Journal of Ecology
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• 제15권4호
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• pp.345-354
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• 1992

Allocation patterns of energy and mineral elements were investigated with phaseolus multiflorus grown in the environmental gradients. The result showed different energy allocation patterns according to relative light intensities and nutrients. The optimal switching time of energy allocation from vegetative to resproductive growth was delated as decreasing relative light intensity. The switch of the shift to reproduction was timed earlier in phosphorus treatment and delayed in nitrogen treatment. Analyzing the mineral elements to various organs, patterns of energy allocation were different from those of mineral allocation. There was no significant difference for allocation patterns in relative light intensity gradients. it was shown that n and p were distributed over the reproductive organs, k mainly in stems, ca in leaves and na in roots. mg was evenly distributed in each organs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4848-4863
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• 2016

The explosive wireless data service requirement accompanied with carbon dioxide emission and consumption of traditional energy has put pressure on both industria and academia. Wireless networks powered with the uneven and intermittent generated renewable energy have been widely researched and lead to a new research paradigm called green communication. In this paper, we comprehensively consider the total generated renewable energy, QoS requirement and channel quality, then propose a utility based renewable energy allocation policy. The utility here means the satisfaction degree of users with a certain amount allocated renewable energy. The energy allocation problem is formulated as a constraint optimization problem and a heuristic algorithm with low complexity is derived to solve the raised problem. Numerical results show that the renewable energy allocation policy is applicable not only to soft QoS, but also to hard QoS and best effort QoS. When the renewable energy is very scarce, only users with good channel quality can achieve allocated energy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권6호
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• pp.2282-2303
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• 2021

To solve the problems of heavy computing load and system transmission pressure in energy internet (EI), we establish a three-tier cloud-edge integrated EI network based on a cloud-edge collaborative computing to achieve the tradeoff between energy consumption and the system delay. A joint optimization problem for resource allocation and task offloading in the threetier cloud-edge integrated EI network is formulated to minimize the total system cost under the constraints of the task scheduling binary variables of each sensor node, the maximum uplink transmit power of each sensor node, the limited computation capability of the sensor node and the maximum computation resource of each edge server, which is a Mixed Integer Non-linear Programming (MINLP) problem. To solve the problem, we propose a joint task offloading and resource allocation algorithm (JTOARA), which is decomposed into three subproblems including the uplink transmission power allocation sub-problem, the computation resource allocation sub-problem, and the offloading scheme selection subproblem. Then, the power allocation of each sensor node is achieved by bisection search algorithm, which has a fast convergence. While the computation resource allocation is derived by line optimization method and convex optimization theory. Finally, to achieve the optimal task offloading, we propose a cloud-edge collaborative computation offloading schemes based on game theory and prove the existence of Nash Equilibrium. The simulation results demonstrate that our proposed algorithm can improve output performance as comparing with the conventional algorithms, and its performance is close to the that of the enumerative algorithm.

• ETRI Journal
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• 제36권3호
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• pp.506-509
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• 2014

This paper studies the energy efficiency power allocation for cognitive radio networks based on uplink orthogonal frequency-division multiplexing. The power allocation problem is intended to minimize the maximum energy efficiency measured by "Joule per bit" metric, under total power constraint and robust aggregate mutual interference power constraint. However, the above problem is non-convex. To make it solvable, an equivalent convex optimization problem is derived that can be solved by general fractional programming. Then, a robust energy efficiency power allocation scheme is presented. Simulation results corroborate the effectiveness of the proposed methods.

• 디지털산업정보학회논문지
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• 제16권1호
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• pp.33-39
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• 2020

A smart grid is a next-generation power grid that can improve energy efficiency by applying information and communication technology to the general power grid. The smart grid makes it possible to exchange information about electricity production and consumption between electricity providers and consumers in real-time. Advanced metering infrastructure (AMI) is the core technology of the smart grid. The AMI provides two-way communication by installing a modem in an existing digital meter and typically include smart meters, data collection units, and meter data management systems. Because the AMI requires data collection units to control multiple smart meters, it is essential to ensure network availability under heavy network loads. If the load on the work done by the data collection unit is high, it is necessary to allocation new data collection units to ensure availability and improve energy efficiency. In this paper, we discuss the allocation scheme of data collection units for the energy efficiency of the AMI.

• 에너지공학
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• 제24권4호
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• pp.1-10
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• 2015

석유생산을 증진시키기 위해 널리 사용되는 대표적인 방법 중 하나인 수공법을 성공적으로 수행하기 위해서는 적절한 물주입량을 정하는 것이 중요하다. 일반적으로 수공법의 주입유량을 할당하기 위하여 생산정과 주입정사이 관계를 정량화하는 well allocation factor(WAF)를 이용한다. 수공법 배열의 기하학적 구조에 따라 WAF를 도출하는 정적(static) WAF는 저류층 물성 및 현장 조건에 대해 고려하지 않기 때문에 부정확한 값을 도출하는 한계가 있어 이를 보완하기 위해 주입 유량, 생산정과 주입정 사이 거리, 주입정 반경 등을 고려한 modified WAF 방법이 제안되었다. 이 연구에서는 정적 WAF와 modified WAF를 적용하여 수공법의 물 주입량을 최적설계하고 결과를 비교 분석하였다. 현장 조건을 고려하지 않는 정적 WAF 보다 modified WAF 방법을 이용하여 물 주입유량을 설계한 경우 적은 양의 물이 주입되면서 생산되는 물의 양이 감소함과 동시에 추가로 생산할 수 있는 석유의 양이 증가하는 것을 확인하였다. 특히 modified WAF 방법은 주입정과 생산정 사이 거리의 변화가 클 경우 주입 유량 최적설계에 효과적임을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.5943-5962
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• 2017

A resource allocation algorithm based on simultaneous wireless information and power transfer (SWIPT) to maximize the system throughput is proposed in orthogonal frequency division multiplexing (OFDM) relay networks. The algorithm formulates the problem under the peak power constraints of the source and each subcarrier (SC), and the energy causality constraint of the relay. With the given SC allocation of the source, we give and prove the optimal propositions of the formulated problem. Then, the formulated problem could be decomposed into two separate throughput maximization sub-problems by setting the total power to transfer energy. Finally, several SC allocation schemes are proposed, which are energy priority scheme, information priority scheme, balanced allocation scheme and exhaustive scheme. The simulation results reveal that the energy priority scheme can significantly reduce computational complexity and achieve approximate performance with the exhaustive scheme.

• 한국정보통신학회논문지
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• 제20권7호
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• pp.1255-1261
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• 2016

무선신호로부터 전력을 수집하는 에너지 하베스팅 기술은 센서의 전원 부족 문제를 해결하고, 무선네트워크의 수명을 향상시킬 수 있는 방안으로 최근 큰 관심을 받고 있다. 본 논문에서는 최적화 기법을 이용하여 에너지 하베스팅이 가능한 인지 라디오 네트워크에서 제 2 사용자의 에너지 효율성을 최대화하기 위한 센싱 시간 및 파워 할당 해를 도출하고, 이를 이용하여 반복 기반의 자원 할당 알고리즘을 제안한다. 시뮬레이션을 통해 제안 방안이 최적의 에너지 효율을 달성함을 보이고, 기존방안(Max rate scheme)과의 비교를 통해 제안 방안의 우수성을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3529-3550
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• 2016

In heterogeneous networks (HetNets), energy saving is vital for a sustainable network development. Many techniques, such as spectrum allocation, network planning, etc., are used to improve the network energy efficiency (EE). In this paper, micro BSs utilizing cell range expansion (CRE) and spectrum allocation are considered in multi-channel heterogeneous networks to improve EE. Hotspot region is assumed to be covered by micro BSs which can ensure that the hotspot capacity is greater than the average demand of hotspot users. The expressions of network energy efficiency are derived under shared, orthogonal and hybrid subchannel allocation schemes, respectively. Particle swarm optimization (PSO) algorithm is used to solve the optimal ratio of subchannel allocation in orthogonal and hybrid schemes. Based on the results of the optimal analysis, we propose three service control strategies on the basis of large-scale user behaviors, i.e., adjust micro cell rang expansion (AmCRE), adjust micro BSs density (AmBD) and adjust micro BSs transmit power (AmBTP). Both theoretical and simulation results show that using shared subchannel allocation scheme in AmBD strategies can obtain maximal EE with a very small area ratio. Using orthogonal subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is larger. Using hybrid subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is large enough. No matter which service control strategy is used, orthogonal spectrum scheme can obtain the maximal hotspot user rates.