Energy-efficient hybrid coded modulations enabling terabit optical ethernet

In addition to capacity, the future high-speed optical transport networks will also be constrained by energy consumption. In order to solve the capacity and energy constraints simultaneously, in this paper we propose the use of energy-efficient hybrid D-dimensional signaling (D>4) by employing all available degrees of freedom for conveyance of the information over a single carrier including amplitude, phase, polarization and orbital angular momentum (OAM). Given the fact that the OAM eigenstates, associated with the azimuthal phase dependence of the complex electric field, are orthogonal, they can be used as basis functions for multidimensional signaling. Since the information capacity is a linear function of number of dimensions, through D-dimensional signal constellations we can significantly improve the overall optical channel capacity. The energy-efficiency problem is solved, in this paper, by properly designing the D-dimensional signal constellation such that the mutual information is maximized, while taking the energy constraint into account. We demonstrate high-potential of proposed energy-efficient hybrid D-dimensional coded-modulation scheme by Monte Carlo simulations.

The article is devoted to consideration of issues related to assessing the energy efficiency of a coal mining enterprise. Coal mining enterprises are characterized by a large volume of energy intensive ore mining operations. The article presents possible ways of energy saving in the mining industry. During the research, a system of energy efficiency indicators for coal mining enterprises is presented. Materials and methods. The article proposes a system of indicators for coal enterprises based on existing methods and approaches to assessing energy efficiency. Energy consumption dependence graphs, benchmarking, and pinch analysis are considered as a starting point. Results. The study presents a system of energy efficiency indicators for coal mining enterprises. The proposed system has several levels. The existing methods and approaches for assessing this important indicator for industrial enterprises in the coal industry as a whole are considered. The author’s approach to formalizing the system of energy efficiency indicators for coal mining enterprises is proposed. The significance of energy audit as a key assessment measure is indicated and its stages are highlighted. The influencing factors determining energy costs and their reduction for a coal mining enterprise are systematized, barriers preventing the practical implementation of energy saving measures are analyzed. Discussion. The proposed metrics system provides a comprehensive framework for assessing the energy efficiency of coal mining enterprises at various levels. Its flexibility allows it to be applied to the analysis of individual equipment units, production processes, and overall enterprise performance. Its multi-level approach provides a detailed understanding of energy consumption, which allows for informed decision-making to optimize operations. At the equipment level, the metrics system evaluates the energy consumption and efficiency of individual machines and devices. At the production process level, the metrics system analyzes the energy consumption and efficiency of various stages of coal mining. At the enterprise level, the metrics system provides a comprehensive assessment of overall energy efficiency. It takes into account energy consumption at all levels and allows enterprises to compare their performance with each other and with industry benchmarks. Conclusion. Energy efficiency assessment of a coal mining enterprise allows to understand how and where energy is used, where its use can be improved, and how to reduce its costs. To conduct an energy efficiency assessment, the article proposes a system of indicators, highlighting the features of an energy audit. The main advantage of the proposed system of indicators is that it covers a wide range of energy consumption indicators, which are carefully selected and located at different levels of detail. In general, a balanced approach to the level of detail and generalization in the system of indicators provides flexibility in adapting indicators to specific research questions and helps to interpret the results in the context of structural differences between energy systems. Resume. Overall, the proposed metrics system offers a comprehensive approach to analyzing the energy efficiency of coal mining enterprises, covering all levels of operations. Its use allows enterprises to improve energy efficiency, reduce operating costs, and contribute to a more sustainable coal mining industry. Suggestions for practical applications and directions for future research. The use and implementation of the developed system at a coal mining company allows it to improve energy efficiency, reduce operating costs and contribute to a more sustainable coal mining industry.

Long-Term Energy Solutions: The Truth Behind the Silent Lie

Recently, researchers have paid much attention to Wireless Power Transfer-based Device-to-Device (D2D) Communication underlaying Cellular Network (WPT-DCCN), which has reliable and controllable energy resource, high energy and spectral efficiency. However, the Energy Efficiency (EE) of the whole WPT-DCCN which combines the time allocation and the power control of all users (including base station, cellular and D2D user), is rarely studied. Consequently, this article establishes an EE optimization model of the whole WPT-DCCN. To effectively get an optimal solution, the EE problem is equivalently converted to an Energy Consumption (EC) minimization problem and is addressed by a proposed Two-Step Iteration Algorithm (TSIA). Simulation shows that the proposed TSIA can give a tight lower-bounded solution of the optimal one. Furthermore, the results also show that whether the WPT from base station to support D2D communication is always energy-efficient, which can give us a clear reference about the deployment of future WPT-DCCN.

Purpose – This paper aims to describe the creation of innovative and intelligent systems to optimise energy efficiency in manufacturing. The systems monitor energy consumption using ambient intelligence (AmI) and knowledge management (KM) technologies. Together they create a decision support system as an innovative add-on to currently used energy management systems. Design/methodology/approach – Energy consumption data (ECD) are processed within a service-oriented architecture-based platform. The platform provides condition-based energy consumption warning, online diagnostics of energy-related problems, support to manufacturing process lines installation and ramp-up phase and continuous improvement/optimisation of energy efficiency. The systems monitor energy consumption using AmI and KM technologies. Together they create a decision support system as an innovative add-on to currently used energy management systems. Findings – The systems produce an improvement in energy efficiency in manufacturing small- and medium-sized enterprises (SMEs). The systems provide more comprehensive information about energy use and some knowledge-based support. Research limitations/implications – Prototype systems were trialled in a manufacturing company that produces mooring chains for the offshore oil and gas industry, an energy intensive manufacturing operation. The paper describes a case study involving energy-intensive processes that addressed different manufacturing concepts and involved the manufacture of mooring chains for offshore platforms. The system was developed to support online detection of energy efficiency problems. Practical implications – Energy efficiency can be optimised in assembly and manufacturing processes. The systems produce an improvement in energy efficiency in manufacturing SMEs. The systems provide more comprehensive information about energy use and some knowledge-based support. Social implications – This research addresses two of the most critical problems in energy management in industrial production technologies: how to efficiently and promptly acquire and provide information online for optimising energy consumption and how to effectively use such knowledge to support decision making. Originality/value – This research was inspired by the need for industry to have effective tools for energy efficiency, and that opportunities for industry to take up energy efficiency measures are mostly not carried out. The research combined AmI and KM technologies and involved new uses of sensors, including wireless intelligent sensor networks, to measure environment parameters and conditions as well as to process performance and behaviour aspects, such as material flow using smart tags in highly flexible manufacturing or temperature distribution over machines. The information obtained could be correlated with standard ECD to monitor energy efficiency and identify problems. The new approach can provide effective ways to collect more information to give a new insight into energy consumption within a manufacturing system.

PurposeHow do energy consumption, efficiency and economic performance vary between small enterprises belonging to two different product clusters whose production process and technologies differ?Design/methodology/approachThe objectives are analyzed based on empirical data gathered from a field survey of small enterprises with reference to auto ancillaries in Shimoga and brick‐making enterprises in Malur of Karnataka State in India. Simple averages, correlation and multiple‐regression techniques are used for the analysis.FindingsThe study brought out that higher energy intensity results in higher share of energy cost in total variable cost. Energy intensity had a negative relationship with value of output. Energy makes a statistically significant contribution to returns to scale. The classification of small enterprises into two groups based on above average energy intensity and below average energy intensity, and the subsequent regression analysis brought out that energy intensity had a positive influence on returns to scale in auto ancillaries whereas a negative influence on returns to scale in bricks enterprises.Research limitations/implicationsThe sample‐size formulation could not be done on a scientific basis due to the absence of comprehensive data on all small enterprises operating in the respective clusters and therefore, the findings may not be generalized.Practical implicationsIndustry specific characteristics must be taken into account while introducing “energy efficiency improvement” programmes as a means of enhancing competitiveness in “energy intensive” small enterprises.Originality/valueThe paper illustrates the scope for energy conservation and efficiency improvement in Indian small enterprises.

Research on the building energy efficiency design strategy of Chinese universities based on green performance analysis

While MIMO technologies are rapidly adopted in 802.11, mobile devices increasingly have different numbers of antennas. Several multiuser MIMO (MU-MIMO) MAC protocols have recently been proposed to allow concurrent transmissions across different links. Though those protocols better utilize the available degrees of freedom, they however do not provide each data stream any receive diversity. This paper introduces multiplexing-diversity medium access (MDMA), a distributed MU-MIMO MAC protocol that achieves both the multiplexing and receive diversity gains at the same time. Instead of letting a node pair use its full degrees of freedom, MDMA allows as many contending node pairs as possible to transmit concurrently and share all the available degrees of freedom. By doing this, MDMA exploits more antennas equipped at different receiving nodes to provide concurrent streams more receive diversity, without sacrificing the multiplexing gain. We show via testbed experiments and simulations that MDMA achieves a similar multiplexing gain, but extracts more diversity gains as the number of antennas at any nodes increases. It hence improves the throughput by up to 48.8 percent as compared to the protocol enabling only spatial multiplexing.

It is noted that, in some cases, it is desirable to synthesize pattern nulls by perturbing the phases of small sub-areas of the aperture or a small number of array elements or subarray blocks of elements. This approach would be required, for example, to provide a null in the sidelobe region of a shaped-beam pattern adaptively; attempting this using all the available degrees of freedom (i.e. with full phase control) would present the difficulty of ensuring that in addition to minimizing the pattern gain at the nulling angle, a high-gain beam of the desired shape is maintained. An additional benefit of nulling using only a small subset of the available degrees of freedom would be that such a system would in practice be simpler and cheaper, and should allow more rapid convergence. It is concluded that, compared to synthesizing the null with full phase control, using phase control on pairs of elements produces slightly inferior but generally quite usable patterns, provided the elements in the pair are chosen appropriately.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Current status and the future of the energy intensity and efficiency of various energy sources are considered and analyzed. Considerations of the Rosenfeld effect, the "energy cliff" and EROI are included. The energy efficiency ratio (EER), the coefficient of performance (COP) as the equivalent measure using SI units, and the 'equivalent COP' are also considered. Energy use per unit of PPT GDP (or general economic intensity of GDP) of selected countries in 2018 is shown, with GDP of the UK and Italy being (according to the Word Bank; expressed in kg of oil equivalent per US$), nowadays, the most energy intensive. The author uses methods of comparative and systematic analyses, which are implemented for assessing the energy intensity and efficiency globally, in the USA, UK, and Germany. Also, investments in the global and German energy sectors are considered. The paper mainly concludes that the global energy intensity tends to decrease in real terms since the beginning of the 70s while energy efficiency also decreases as non-conventional fuels are more actively developed.

Highlights on energy efficiency improvements: a case of a small brewery

Recently, Palestine has been willing to improve its energy efficiency action plan and policies. As the Electrical demand for energy is increasing in Palestine, improving energy efficiency can be considered as an efficient way to achieve reductions in energy consumptions. In this respect, energy efficiency action plan and its strategies must be designed to overcome existing market barriers against using energy efficient appliances in residential and commercial sectors in Palestine. This study provides background on the benefits of stakeholders and steps needed to support energy efficiency standards and labeling in Palestine. Furthermore, this study attempts to predict the techno-economic impact of implementing high efficient electrical appliances in Palestine. Survey-based analyses from 300 households were conducted in 2019 to estimate residential sector electrical appliances usage, behavior and their knowledge in electrical appliances labels and standards, the study aims also to estimate the perception and willingness of Palestinian householders to shift towards more energy efficient choices. The study will focus on 8 electrical appliances that constitute a major share of the electricity used within households and commercial sectors in Palestinian market.

With growing concern about environmental issues and an emerging green communications paradigm, cognitive radio (CR) networks (CRNs) have to be considered from the energy efficiency perspective. In this paper, we focus on scheduling in CRNs, in which a cognitive base station (CBS) makes frequency allocations to the CRs at the beginning of each frame. A cognitive scheduler must consider the diversity among CRs' queues and channel capacities in terms of number of bits and the channel switching cost from one frequency to another. Taking all these into account, we formulate the scheduling problem as an energy efficiency maximization problem, which is a nonlinear integer programming (NLP) problem and is thereby hard to solve. We seek alternate computationally easier solutions. To this aim, we propose a polynomial-time heuristic algorithm, i.e., the energy-efficient heuristic scheduler (EEHS), which allocates each idle frequency to the CR that attains the highest energy efficiency at this frequency. Next, we reformulate the original problem first as a throughput maximization problem subject to energy consumption restrictions and then as an energy consumption minimization problem subject to minimum throughput guarantees. These two schedulers also have the power to provide fairness in resource allocation. We analyze the energy efficiency and successful transmission probability of the proposed schedulers under both contiguous and fragmented spectrum scenarios. Performance studies show that, compared with a pure opportunistic scheduler with a throughput maximization objective, proposed schedulers can attain almost the same throughput performance with better energy efficiency.

In this keynote invited paper, to address key challenges for beyond 5G wireless technologies in a simultaneous manner, we propose an orbital angular momentum (OAM) based, energy-efficient multidimensional coded modulation. The key idea is to employ all available degrees of freedom (DOFs) to convey the information over the wireless links including amplitude, phase, polarization state, and spatial-domain DOFs. In particular, the OAM is associated with azimuthal phase dependence of the wavefront, and represents an underutilized DOF. Given that OAM eigenstates are orthogonal, an arbitrary number of bits per symbol can be transmitted. To implement OAM multiplexer and demultiplexer in the RF domain, we propose to use a properly designed antenna arrays. Monte Carlo simulations demonstrate high tolerance to fading effects of LDPC-coded multidimensional signaling schemes compared to conventional LDPC-coded QAM.

The realization of sustainable development depends on the efficient use of energy resources. Energy consumption productivity and efficiency are among important indices that play a critical role in explaining the behavior of energy consumption structure of different economic sectors, which in turn, plays a key role in policy making. From among economic sectors, the agriculture sector, as an important sector, depends on the consumption of energy as a factor underpinning agricultural production to a great extent. Thus, the present study tries to firstly calculate energy efficiency and productivity of agricultural sector, and then, investigate the relationship between production and energy consumption of New Zealand’s agricultural sector using simultaneous equations system and two-stage least squares method. The annual data of New Zealand agricultural economics are used for the period of 1990-2017. The results showed that agricultural sector’s energy consumption efficiency in New Zealand was mostly optimum according to energy efficiency index. In addition, estimation of energy equation revealed that the added value of agricultural sector had a positive influence on energy consumption growth. Among the other positively affecting variables, agricultural sector’s labour and energy consumption in the prior period could be mentioned. The negative sign of capital stock in the equation reflects the fact that the higher the investment in agricultural sector, the lower the energy consumption.