The emergence of enterprise WLAN as a key technology has posed numerous challenges to researchers. Presented is a novel, theoretically‐grounded, distributed dynamic buffering mechanism to address two ...of those challenges, namely, buffer stability and power consumption costs. The proposed mechanism optimally controls the buffer dynamics of system switches, thereby guaranteeing buffer queue stability, and minimising time‐average expected power expenditure, thereby decreasing costs.
This paper presents self-manufacturing cost estimation, cost optimization and competitiveness of different composite floor systems: composite I beams, composite trusses produced from rolled channel ...sections and composite trusses made from cold formed hollow sections.
Part 1 of this two-part series of papers presents the estimation of the self-manufacturing (direct production) costs for composite and steel structures. The self-manufacturing costs are proposed to be defined as the sum of the material, the power consumption and the labour costs. The material costs of the structural steel, concrete, reinforcement, the shear connectors, electrodes, the anti-corrosion, fire protection and top coat painting, the formwork floor-slab panels and gas consumption are presented in detail. The power consumption costs comprise costs of sawing the steel sections, edge grinding, drilling, welding, stud welding and vibrating the concrete. The labour costs (times) presented define the costs of metal cutting, edge grinding, preparation, assembling and tacking, welding, welding of shear connectors, steel surface preparation and protection, drilling, cutting, placing and connecting the reinforcement, concreting, consolidating and curing the concrete. New approximation functions are proposed for the calculation of some manufacturing times and material consumptions. As the discussed costs vary significantly around the world, the proposed cost expressions are given in the open form to be used for cost estimation in different economic conditions. A numerical example of the estimation of the self-manufacturing costs for a composite I beam floor system shows the suitability of the proposed approach.
On the basis of the defined self-manufacturing costs, introduced in Part 1, the cost optimization and the competitiveness of different composite floor systems are discussed in Part 2.
Based on the physical model of load and the control model of expressing user’s subjective use intention, refined modeling methods are proposed for three typical high-power controllable loads on ...residential side, namely, heating-ventilation and air conditioning (HVAC) system, electric water heater and charging load of electric vehicle (EV) and the refined models are carried out. First of all, a custom family example is constructed, including the user’s electricity habits, structural characteristics of the house and the load, and the simulation is carried out. The refined definition of technical parameters and the influence of typical and atypical electricity consumption process on load electricity consumption effect are analyzed in detail. Then, an optimization model of energy management strategy aiming at optimizing electricity consumption cost is established based on traditional saving families and modern comfortable families. Simulation results show that the user personalized electricity consumption habits and environment have a significant impact on the control strategy of home energy management system (HEMS).
•Propose a refined control model of HVAC and electric water heater for the adjustable range.•Introduce a quantifiable emergency coefficient of EV of charging demand.•Establish an optimization model of HEMS based on refined load models.•Propose an intelligent HEMS to meet different kinds of families.
The emerging non-orthogonal multiple access (NOMA) has been considered as a promising scheme to reach the goals of 5G cellular systems. By enabling a group of mobile users (MUs) to share a same ...frequency channel and adopting the successive interference cancellation to mitigate the co-channel interference, NOMA can improve the spectrum efficiency compared with the orthogonal multiple access (OMA). This study proposes a joint optimisation scheme of the channel bandwidth and the transmit-power allocations for the NOMA downlink transmission, which aims at minimising the overall resource consumption cost including both the spectrum consumption and the power consumption, while satisfying the MUs' traffic requirements. In spite of the non-convexity nature of the joint optimisation problem, this study characterises the connection between the channel bandwidth and the associated transmit powers for the MUs. Based on this connection, this study transforms the joint optimisation problem into an equivalent bandwidth optimisation problem, and further proposes an efficient algorithm to compute the optimal bandwidth allocation (which enables us to derive the corresponding transmit powers for the MUs). Extensive numerical results are provided to validate the proposed algorithm and the advantage of the proposed joint channel bandwidth and power allocations for the NOMA transmission.
A key concern in the design of 5G is the radio access network, which is expected to be significantly denser and more advanced, with considerably higher infrastructure and power consumption cost than ...that of conventional mobile network standards. Novel algorithms/approaches for optimal planning of the radio access network are required for tackling the additional complexity of the problem of cost-efficient radio access planning in 5G, which cannot be properly handled by conventional approaches. This study proposes a novel optimisation framework for the cost-efficient deployment and configuration of 5G base stations. The main idea of the proposed optimisation framework is to exploit heterogeneity in three key 5G technologies, heterogeneous base station architecture, cell range extension and multiple-input–multiple-output spatial multiplexing, by jointly optimising their configurations during network design. In addition, the proposed optimisation framework includes generic steps for applying meta-heuristic algorithms to the problem, which are necessary to overcome the problem's complexity, especially for large problem instances. The authors’ results show that their novel optimisation framework improves the cost efficiency of the network planning both in terms of power and infrastructural cost to operators.
This paper presents comparative results on Hierarchical Mobile IPv6 and Proxy Mobile IPv6. The two mobility support protocols have similar hierarchical mobility management architectures but there ...are, however, clearly different perceptions: Hierarchical Mobile IPv6 has specific properties of a host-based mobility support protocol, whereas Proxy Mobile IPv6 is based on a network-based mobility support protocol. Thus, it is important to reveal their mobility characteristics and performance impact factors. In this paper, a cost based evaluation model is developed that evaluates the location update cost, the packet delivery cost, and the wireless power consumption cost based on the protocol operations used. Then, the numerical results are presented in where impacts of the various system parameters are evaluated. The results demonstrate that Proxy Mobile IPv6 always outperforms Hierarchical Mobile IPv6 due to its ability to avoid the mobility signaling sent by the mobile host, and its reduced tunneling overhead during communications with other nodes.
The resistor-capacitor network (RC models) is a common approach to model thermal systems in buildings that proves advantageous in improving a building's energy efficiency. This paper presents a ...framework for energy consumption cost estimation and power efficient control in buildings-based model predictive control. The proposed framework calculates the electricity cost for dwellings based on their sizes using RC models. Additionally, it ensures consistent thermal comfort within the controlled building even during performance issues. The calculation of the cost of energy consumption takes into account the electricity tariff provided by Hydro-Quebec, Montreal, Quebec, Canada. Model Predictive Control (MPC) along with two backup controllers (ON/OFF control and Proportional-Derivative-Integral (PID) control) optimize the thermal model in a building, ensuring the desired indoor temperature efficiently with low cost. The Simulation results conducted on the Matlab/Simulink platform demonstrated that MPC control outperforms the other controllers in terms of energy consumption minimization and cost.
With the advancement of 5G technology, user demand grows, resources become scarce and differentiated services place greater requirements on performance in slice-MEC system. However, optimizing works ...in the vast majority of existing research focus only on slice selection, resource orchestration, utility improvement from the perspective of users, without considering whole system's power consumption cost. Firstly, to get over this dilemma, a two-tier architectural model for slice-MEC system is proposed, which is mainly divided into the slice instance layer and infrastructure layer. Next, we establish the optimization problem of minimizing weighted power consumption cost while guaranteeing requirements of delay and rate, taking into account both communication and computational resources. Moreover, to solve the problem above, the HPCA-based resource management and computing offloading algorithm is designed. Finally, simulation results show that the proposed algorithm in this paper outperforms than benchmark algorithms and we also analyse the performance of the system by varying different parameter conditions.
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