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Abstract: The pulp and paper industry both uses and produces large amounts of energy and rising fuel prices bring along significant challenges to the sector. Several strategies can be applied in order to remain competitive e.g. an increase in energy efficiency, a switch in fuel and/or a novel energy conversion technology. In this study, we investigate if improved energy conversion strategies can reduce energy costs, primary energy use and CO2 emissions of paper mills within different European countries (The Netherlands, Poland and Sweden). Our results show that differences in history and availability of resources has led to different conversion strategies in the three countries. We found that a natural gas combined cycle, which is largely implemented in The Netherlands due to long term domestic availability of natural gas, has the lowest primary energy demand. Due to a long history of low electricity prices, CHP has not been common in Sweden. Many Swedish mills use biomass as an energy source and due to low CO2 emissions of the national grid the CO2 emission profile of the Swedish paper industry is very low. Our results imply that future conversion routes for the Swedish paper and board industry are again wood based; in case of increasing electricity prices these would be biomass gasification based CHP solutions. With a reduction of 800kg CO2/ton paper on average, a switch from coal to biomass would reduce CO2 emissions in the Polish pulp and paper industry with approximately 0.6Mton/year. A carbon price of 20–25€/ton would, according to our results, be enough to provoke this switch. Due to the high share of natural gas, the CO2 emission reduction potential of the Dutch paper industry (1.5Mton/year) is even larger than in Poland. Due to high biomass prices and relative low CO2 emission profile of natural gas, a carbon prices of more than 60€/ton CO2 would be needed to provoke a switch in The Netherlands. Provided with few alternatives, the most effective strategy in The Netherlands would be an increase in energy efficiency. [Copyright &y& Elsevier]

Abstract: This paper studies allocation of fuel costs and CO2-emissions to heat and power in a CHP plant producing heat to an integrated pulp and paper mill and electricity to the liberalized electricity markets (or to the mill by the market price). The CHP plant and the mill are considered to be two separate economical units and both the mill and the CHP plant perspectives are discussed. Fuel costs and CO2-emissions are allocated using the energy, exergy and market based methods. The CHP plant purchases black liquor and bark from the mill. It also purchases oil from the markets to cover the whole fuel demand of the plant. The results indicate that the marked based method can be recommended as a “neutral” cost allocation method, because with that, the energy producer is not collecting extra margins from selling steam. This means that heat pricing is cost based. The results also indicate that depending on the emission factor and efficiency of alternative energy production form, the marked based method or the exergy method allocate the lowest CO2-emissions to heat. Therefore, the use of market based method for allocating costs and CO2 emissions can be recommended in order to use one single approach in both. [Copyright &y& Elsevier]

Optimizing the energy consumption of an MEC (Multi-Access Edge Computing) system is a crucial challenge for operation cost reduction and environmental conservation. In this paper, we address an MECS (MEC Server) sleep control problem that aims to reduce the energy consumption of the system while providing users with a reasonable service delay by adjusting the number of active MECSs according to the load imposed on the system. To tackle the problem, we identify two crucial issues that influence the design of an effective sleep control technique and propose methods to address each of these issues. The first issue is accurately predicting the system load. Changes in system load are spatio-temporally correlated among MECSs. By leveraging such correlation information with STGCN (Spatio-Temporal Graph Convolutional Network), we enhance the prediction accuracy of task arrival rates for each MECS. The second issue is rapidly selecting MECSs to sleep when the load distribution over an MEC system is given. The problem of choosing sleep MECS is a combinatorial optimization problem with high time complexity. To address the issue, we employ a genetic algorithm and quickly determine the optimal sleep MECS with the predicted load information for each MECS. Through simulation studies, we verify that compared to the LSTM (Long Short-Term Memory)-based method, our method increases the energy efficiency of an MEC system while providing a compatible service delay. [ABSTRACT FROM AUTHOR]

• The 2024 Wheelchair Compendium of Physical Activities presents the energy expenditure values for 124 PAs in 6 Major Headings (Exercise, Household Activities, Inactivity, Miscellaneous, Sports/Recreation, and Transportation). • The 2024 Wheelchair Compendium is the first update to the Wheelchair Compendium of Physical Activities published in 2011. • The 2024 Wheelchair Compendium of Physical Activities contains PA energy costs from 47 articles obtained using a systematic review of the published literature. • The metabolic equivalent of task for manual wheelchair users (MET WC) identifies the PA energy expenditure computed as the activity kcal/kg/h divided by the resting kcal/kg/h. • The 2024 Wheelchair Compendium of Physical Activities can be accessed at https://pacompendium.com. This paper presents an update of the 2011 Wheelchair Compendium of Physical Activities designed for wheelchair users and is referred to as the 2024 Wheelchair Compendium. The Wheelchair Compendium aims to curate existing knowledge of the energy expenditure for wheelchair physical activities (PAs). A systematic review of the published energy expenditure of PA for wheelchair users was completed between 2011 and May 2023. We added these data to the 2011 Wheelchair Compendium data that was compiled previously in a systematic review through 2011. A total of 47 studies were included, and 124 different wheelchair PA reported energy expenditure values ranging from 0.8 metabolic equivalents for wheelchair users (filing papers, light effort) to 11.8 metabolic equivalents for wheelchair users (Nordic sit skiing). In introducing the updated 2024 Wheelchair Compendium, we hope to bridge the resource gap and challenge the prevailing narratives that inadvertently exclude wheelchair users from physical fitness and health PAs. [Display omitted] [ABSTRACT FROM AUTHOR]

Efforts such as the Glasgow United Nations Climate Change Conference of the Parties 26, the Paris Agreement (Paris agreement, United Nations, Paris, 2015) and the United Nations Sustainable Development Goals are supporting the drive to protect the planet from global warming by ensuring sustainable development. The oil and gas industry, as key contributor to greenhouse gas emissions, must transition to more sustainable energy solutions and play their part in reducing these emissions. Currently, oil and gas companies are implementing technical solutions to achieve net zero carbon emissions. The energy transition from fossil fuel reliance has also happened by exploiting alternative renewable energy sources to meet global energy demand such as wind, solar, biogas and bioderived feedstocks. This net zero energy transition will require a fair and just transition for all in society, and to implement this, it is crucial for those working in the oil and gas industry to understand the technologies needed, the importance of carbon policies and their roles. This research presents a modified Delphi study of employees in Malaysia's national oil and gas company to understand their perceptions towards a net-zero carbon future. The paper briefly reviews Malaysia's low-carbon policy plans, its current carbon dioxide accounting balance, and identifies potential technologies for decarbonisation to set the scene for the modified Delphi study. The results indicated that the national oil and gas company has both the capabilities and the financial resources to significantly contribute towards Malaysia transitioning to a carbon neutral nation. This can be achieved by implementing advanced technologies complementing with nature-based solutions to realise net zero carbon emissions. This study also portrays the confidence that the portfolio of solutions should be executed through a coordinated effort to maximise the outcome and minimise the financial impact in terms of economical sustainability. Implementation of activities towards this energy transition will require significant social commitment, and hence, gauging their perception towards this journey is key objective of this paper. [ABSTRACT FROM AUTHOR]

Despite improving various technical indices such as operation and voltage profile, the integration of synchronous distributed generations (SDGs) may lead to the loss of protection coordination in the distribution network (DN). To tackle the problem, this paper presents a multi‐objective siting and sizing of SDGs on DN considering operation, economic and protection coordination indices simultaneously. The proposed scheme is structured in the framework of a four‐objective optimization problem, which aims to minimize the energy losses, the worst voltage security index (VSI), planning cost of SDGs and the protection index (PI) (the deviation of coordination time interval). Therefore, it is constrained to power flow equations, VSI, and protection coordination of overcurrent relays (OCRs). Then, the Pareto optimization based on the method of the weighted functions summation obtains an integrated single‐objective problem for the proposed scheme. Next, a hybrid evolutionary algorithm formed by merging particle swarm optimization (PSO) and crow search algorithm (CSA) is incorporated to achieve the optimal solution with unique response approximate conditions. Eventually, the suggested scheme is applied on distribution portion of IEEE 30‐bus ring and IEEE 69‐bus radial DN and numerical results confirm the efficient performance of SDG planning in terms of technical indicators and protective devices coordination. [ABSTRACT FROM AUTHOR]

Heart rate is one of the important indices to calculate and evaluate the intensity and quality of motion. It can scientifically and objectively reflect the intensity level of momentum and exercise in the process of exercise. It is an important index of athletic strength and physical fitness of athletes in college sports training. This paper analyzes the basic metabolic model of the human body and energy supply and demand model and constructs a scientific energy consumption test model for special sports activity. An algorithm for heart rate detection and energy consumption based on acceleration data acquisition is proposed. Therefore, it is proposed to calculate motion acceleration using bone point data obtained from a portable telephone camera sensor for special sports activity and to calculate kinetic energy consumption through detection data. A model for evaluating the proposed algorithm is also established. [ABSTRACT FROM AUTHOR]

This paper analyses a part of the results regarding environmental education (EE) and education for sustainable development (ESD) in Romania, obtained by administering a survey in 2017, willingly and anonymously filled out by 335 teachers (preschool teachers, primary school teachers, Geography teachers). It examines: respondents' interest, importance, knowledge and involvement in EE and sustainable development (SD); activity impact on teacher knowledge, attitude and behaviour towards SD and environment in Romania; importance of aims and levels in EE and ESD; EE and SD activities involving preschoolers and pupils as well as their frequency; the efficiency of some activities in preschoolers' and pupils' EE and ESD; problems that may occur due to a subpar EE. In its conclusions, the paper highlights several measures for an increase in EE and ESD levels. [ABSTRACT FROM AUTHOR]

The article offers comments and discussion on the report "The Economics of Place-Making Policies" by Joshua Gottlieb and Edward L. Glaeser. The author discusses how nations such as the U.S. are reacting to higher energy prices, and how U.S. policy discourages population density despite the economic advantages that Internet service and increased public transportation offer. The author discusses urban economics, and how the U.S. is affected by ready automobile access to most destinations, and how this affects the use of public transportation. The author considers whether the U.S. government should use policy, taxation and subsidies to the poor according to geographical location.

Purpose In order-picking activities, the performance of the system can be influenced by different variables such as the order to be fulfilled, the distance to be covered or the experience of operators. Usually, this kind of activity is performed by operators rather than machines to assure flexibility. Consequently, their fatigue accumulation can decrease the performance of the overall system. The purpose of this paper is to define the kind of device to be used in an order-picking context, to obtain data which can be utilized for the evaluation of the level of fatigue and to improve the performance of the picking system.Design/methodology/approach The paper presents a comparison between existing fatigue methods which can be applied in a picking context. In addition, an analysis of the physiological literature for the evaluation of a new device for the monitoring of fatigue level is carried on and its practical use is shown.Findings The proposed research identifies in the heart rate monitor the device that, thanks to its advantages, can be the best one to be used in an industrial context for monitoring the physical fatigue of operators.Originality/value This study considers the importance of human factors in picking activities such as physical fatigue of operators and the need to have validated tools to monitor and to define the level of fatigue accumulation in each activity of different rate and duration. [ABSTRACT FROM AUTHOR]

Simple Summary: Obesity and diabetes have detrimental impacts on skeletal health that result in an increased fracture risk and impaired fracture healing, conditions associated with significant morbidity and mortality and that are costly to treat. Managing obesity-induced bone loss is complicated by the fact that anti-diabetic drugs have negative or unknown impacts on bone health, which limits their effectiveness. Inositol hexakisphosphate kinase 1 (IP6K1) functions as a prominent regulator of energy expenditure based on data showing its inhibition protects mice from diet-induced obesity. In this paper, we show that the pharmacological inhibition of IP6K1 after the onset of a high-fat diet feeding protects mice against weight gain and its associated metabolic derangements even under thermo-neutral conditions, and that kinase inhibition also preserves bone mass, bone micro-architecture, and the pool of skeletal stem/progenitors in bone marrow. Obesity also has negative impacts on male fertility, but prolonged IP6K1 inhibition had no adverse impacts on male reproductive parameters. These findings identify IP6K1 as a preferred target for glycemic control due to the bone sparing effects of IP6K1 inhibition. Obesity and type II diabetes mellitus (T2DM) are prominent risk factors for secondary osteoporosis due to the negative impacts of hyperglycemia and excessive body fat on bone metabolism. While the armamentarium of anti-diabetic drugs is expanding, their negative or unknown impacts on bone metabolism limits effectiveness. The inactivation of inositol hexakisphosphate kinase 1 (IP6K1) protects mice from high-fat-diet (HFD)-induced obesity (DIO) and insulin resistance by enhancing thermogenic energy expenditure, but the role of this kinase and the consequences of its inhibition on bone metabolism are unknown. To determine if IP6K1 inhibition in obese mice affords protection against obesity-induced metabolic derangements and bone loss, we maintained 2-month-old mice on a normal chow control diet or HFD under thermal neutral conditions for 100 d. Beginning on day 40, HFD-fed mice were divided into two groups and administered daily injections of vehicle or the pan-IP6K inhibitor TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl) purine]. HFD-fed mice developed obesity, hyperglycemia, hyperlipidemia, and secondary osteoporosis, while TNP administration protected mice against HFD-induced metabolic and lipid derangements and preserved bone mass, mineral density, and trabecular microarchitecture, which correlated with reduced serum leptin levels, reduced marrow adiposity, and preservation of marrow resident skeletal stem/progenitor cells (SSPCs). TNP also exhibited hypotensive activity, an unrealized benefit of the drug, and its prolonged administration had no adverse impacts on spermatogenesis. Together, these data indicate that the inhibition of IP6K1 using selective inhibitors, such as TNP, may provide an effective strategy to manage obesity and T2DM due to its bone sparing effects. [ABSTRACT FROM AUTHOR]

Efforts towards educating people about the importance of sleep and regular sleep timing could be a first strategy to help improve health. They showed in a group of ~5000 adults (19-64 years) that short sleep and irregular sleep timing were associated with higher intakes of non-milk extrinsic sugars, and that irregular sleep timing was associated with lower fibre intake in those with adequate sleep duration(1). In the most recent issue of Public Health Nutrition 2022, Al Khatib I et al i . published an interesting paper on the associations and interactions between sleep duration and social jetlag with nutrient intake and cardio-metabolic risk factors in a nationally representative UK population. The majority of the paper focuses on the duration of sleep, but the authors also showed irregular sleep timing to be associated with poorer nutrient intake. [Extracted from the article]

Since pedestrians are impacted by solar radiation differently, urban designers must evaluate solar radiation exposure of pedestrian paths adopting an inclusive approach. This paper proposes a maximum threshold of direct solar radiation exposure for pedestrians based on activity, user profile and environmental conditions, defined as the difference between the energy consumption before feeling exhausted and the energy cost of walking. Two users of diverse walking abilities, a young adult and an elderly person with mobility impairment, were characterised by metabolic activity, walking speed and maximum energy capacity. Based on the theoretical framework, the energy budget of young adults to cope with thermal stress was set as three times higher than for the elderly. This framework was used to quantify the contribution of direct solar radiation to energy balance and then classify walkability during clear-sky summer hours; the term 'walkable' referred to environmental conditions allowing users to walk without feeling exhausted. The methodology was tested on an open area and an urban canyon in Milan; applicability by urban designers was key in developing a simplified way to evaluate shading needs. This approach could be applied to evaluate solar radiation exposure of pedestrian paths adopting diverse user experiences as an evaluation criterion. [ABSTRACT FROM AUTHOR]

In this paper, we consider the classification problem of functional data including the sleeping energy expenditure (SEE) data, focusing on functional classification. Many existing classification rules are not effective in distinguishing the two classes of SEE data, because the trajectories of each observation have very different patterns for each class. It is often observed that some aspect of data such as the variability of paths is helpful in classification of functional data. To reflect this issue, we introduce a variable measuring the length of path in functional data and then propose a logistic model with fused lasso that considers the behavior of fluctuation of path as well as local correlations within each path. Our proposed model shows a significant improvement over some models used in the existing literature on the classification accuracy rate of functional data such as SEE data. We carry out simulation studies to show the finite sample performance and the gain that it makes in comparison with fused lasso without considering path length. With two more real datasets studied in some existing literature, we demonstrate that the new model achieves better or similar accuracy rate than the best accuracy rates reported in those studies. [ABSTRACT FROM AUTHOR]

In the second half of the 19th and early 20th century, sheep shepherds have built dry-stone shelters all over the Slovene Kras (or Karst) region. Despite being made out of stones that are interlocked without the use of any binding material, many of these vernacular constructions survived – even though sometimes only partially – the ravages of time. The fact that over one hundred fifty shepherd shelters are currently known is mainly due to the craftsmanship of their builders and thanks to (and even despite) their present location. A majority of these stone constructions can be found in areas that are nowadays forested, thus shielding them from weather-related or anthropogenic damage (because they are difficult to spot). This paper reports on the geometric documentation of those shelters using a photogrammetric computer vision pipeline, thereby mainly focussing on the difficulties that were encountered during this process. However, such image-based modelling approaches merely yield digital three-dimensional (3D) approximations of the shelters' surface geometry (along with some sub-optimal colour data). Although these 3D surface models might be suitable to digitally preserve vulnerable vernacular buildings to some extent, they do not magically advance our understanding of them. The second part of this article focuses, therefore, on the extraction of archaeological information from these digital 3D constructions. More specifically, the total amount of stones, the total building time and the building cost regarding caloric energy expenditure are estimated for each of the digitised shelters. Although this assessment of architectural energetics provided useful insight into the building efforts and nutrient uptake of the shepherds, it also revealed many assumptions and shortcomings that often characterise archaeological information extraction from digital 3D models of buildings. [ABSTRACT FROM AUTHOR]

Energy cost is the main constraint in modern wireless communication system. A powerful scheme due to optimal energy cost is provided for a single node server in this paper. In wireless communications, the total energy for transmitting packets can be reduced by proper regulating the service rate due to different packet sizes. In our study, a generic method applying the Lagrange Multiplier methods for optimizations is proposed. We show the energy cost is a convex function and it is easy to achieve the optimization. Our contribution focused on minimizing the total energy cost induced by the transmission energy in a single server with multi-queues. The methodology presented in this paper can effectively save the energy cost due to energy consumption in wireless communication systems. [ABSTRACT FROM AUTHOR]

In this paper, a two-stage stochastic unit commitment (UC) model considering flexible scheduling of demand response (DR) is proposed. In the proposed UC model, the DR resources can be scheduled: (1) in the first stage, as resources on a day-ahead basis to integrate the predicted wind fluctuation with lower uncertainty; (2) in the second stage, as resources on an intra-day basis to compensate for the deviation among multiple wind power scenarios considering the coupling relationship of DR on available time and capacity. Simulation results on the Pennsylvania-New Jersey-Maryland (PJM) 5-bus system and IEEE 118-bus system indicate that the proposed model can maximize the DR value with lower cost. Moreover, different types of DR resources may vary in the contract costs (capacity costs), the responsive costs (energy costs), the time of advance notice, and the minimum on-site hours. The responsive cost is considered as the most important factor affecting DR scheduling. In addition, the first-stage DR is dispatched more frequently when transmission constraints congestion occurs. [ABSTRACT FROM AUTHOR]

Metabolic chambers are powerful tools for assessing human energy expenditure, providing flexibility and comfort for the subjects in a near free-living environment. However, the flexibility offered by the large living room size creates challenges in the assessment of dynamic human metabolic signals—such as those generated during high-intensity interval training and short-term involuntary physical activities—with sufficient temporal accuracy. Therefore, this paper presents methods to improve the temporal accuracy of metabolic chambers. The proposed methods include 1) adopting a shortest possible step size, here one minute, to compute the finite derivative terms for the metabolic rate calculation, and 2) applying a robust noise reduction method—total variation denoising—to minimize the large noise generated by the short derivative term whilst preserving the transient edges of the dynamic metabolic signals. Validated against 24-hour gas infusion tests, the proposed method reconstructs dynamic metabolic signals with the best temporal accuracy among state-of-the-art approaches, achieving a root mean square error of 0.27 kcal/min (18.8 J/s), while maintaining a low cumulative error in 24-hour total energy expenditure of less than 45 kcal/day (188280 J/day). When applied to a human exercise session, the proposed methods also show the best performance in terms of recovering the dynamics of exercise energy expenditure. Overall, the proposed methods improve the temporal resolution of the chamber system, enabling metabolic studies involving dynamic signals such as short interval exercises to carry out the metabolic chambers. [ABSTRACT FROM AUTHOR]

This paper introduces an adaptive multiresolution framework for electric vehicle (EV) energy consumption estimation with real-time capability. Three key parameters, namely powertrain efficiency, wind speed, and rolling resistance, are adaptively estimated using a two-step nonlinear iterative algorithm. Based on this algorithm, a multichannel framework for high-resolution powertrain efficiency estimation is introduced. Employing the “connected vehicles” concept, more reliable trip level energy estimates are achieved by sharing sensed environmental information. In addition, state-of-charge aware energy cost prediction methods of different accuracy and complexity are introduced to combat range anxiety and reduce computational complexity during times of high energy reserves. A variety of detailed simulations illustrate the introduced concept and its benefits for future EV systems. [ABSTRACT FROM PUBLISHER]

Recently, the need for assembly systems of better following the market demand has led to the spread of alternative solutions with respect to the traditional fixed worker strategy. Walking worker systems, where operators move across the line to produce the finished product, are gaining always more interest. In this paper, a comparison between the fixed worker (FW) and the walking worker (WW) assembly strategies is provided, by taking into account their differences both in terms of performed activities during assembly and of material exposure at the assembly workstations. The evaluation is carried out through the proposal of a mathematical model, to understand the impact on assembly time and on operators' energy expenditure. The behavior of the model is investigated both with a parametric analysis and a real case study. The results show that the FW is the best one when the system is working at its maximum throughput, while the WW strategy turns out to be preferable for the lower values of market demand, both from a time and an energy expenditure perspective. [ABSTRACT FROM AUTHOR]

Recently, athletes have become more interested in low carbohydrate (CHO) diets (LCD, LCHF), whether for performance or health reasons. This short review paper summarises the current dietary recommendations for sports, introduces LCDs, highlights some of the important historical developments, introduces the concept of „fuel for the work required" and presents selected reports, case studies, and studies. It provides a brief overview of some of the key risks and disadvantages of LCDs in athletes without and with diabetes. [ABSTRACT FROM AUTHOR]

This study presents a detailed feasibility analysis of technical and financial assessment for grid-connected Hybrid Renewable Energy System (HRES) configurations by including grid-only, HRES-only and grid-HRES at four different provinces in the Kingdom of Saudi Arabia (KSA), namely; (Al Baha University, University of Jeddah, Prince Sattam Bin Abdulaziz University, and Tabuk University). The objective of this paper is to search the possibility of supplying the load demand with the optimum system that has the lowest net present cost (NPC) and greenhouse emission CO2. The simulation results show that NPC of a proposed grid/PV system, at the current grid's tariff, is more sufficient than other configurations with a result in a renewable fraction of more than 50%, a payback time of 17 years, and 54.3% reduction in CO2. The results also show that the integration of 62 kW PV array with the main grid is the best configuration that leads to the minimum cost of energy (COE) of 0.0688 $/kWh and the sell back energy of 9.16% of total energy consumption at Al Baha University. Besides, optimization modeling addresses that HRES-only system can supply the full load demand without power shortage (<0.1%) with a major contribution from solar PV by 78.5%, wind energy shares 11.3% of load demand, and 10.2% from battery banks. The developed analysis concludes that the objective function is feasible for the selected locations. The study has three novelties. Firstly, the required load at different locations of the university's buildings at KSA is supplied by minimizing COE. The objective function is achieved by considering a combination of HRES. Then, it applies the sensitivity analysis for several cases such as payback time, gird's tariff variation, and load demand change. Finally, the current analyses are applicable to any university at KSA and around the world. [ABSTRACT FROM AUTHOR]

PDEs restrict the positive inotropic effects of β-adrenoceptor stimulation by degrading cAMP. Hence, PDE inhibitors sensitize the heart to catecholamines and are therefore used as positive inotropes. On the downside, this is accompanied by exaggerated energy expenditure, cell death and arrhythmias. For many years, PDE3 was considered to be the major isoform responsible for the control of cardiac force and rhythm. However, recent work in gene-targeted mice and rodent cells has indicated that PDE4 is also involved. Furthermore, selective PDE4 inhibitors augment catecholamine-stimulated cAMP levels and induce arrhythmias in human atrial preparations, which suggests that PDE4 has a more prominent role in the human heart than anticipated, and that PDE4 inhibitors such as roflumilast may carry an arrhythmogenic risk. In this issue of the journal, a team of researchers from three laboratories report on the effect of PDE3 and PDE4 inhibitors on ventricular trabeculae from explanted human hearts. The key result is that the PDE4 inhibitor rolipram does not affect the positive inotropic effects of β1- or β2-adrenoceptor stimulation. Given that the ventricle rather than the atria is the critical region in terms of arrhythmogenic consequences, this is an important and reassuring finding. Linked Article This article is a commentary on the research paper by Molenaar et al., pp. 528-538 of this issue. To view this paper visit http://dx.doi.org/10.1111/bph.12167 [ABSTRACT FROM AUTHOR]

This paper presents an innovative concept of a closed-loop machining cell for turbine blade finishing that integrates a robotic surface finishing device with an electro-optical, non-contact precision measuring system. We propose that a synergistic combination of these leading edge technologies allows us to close the loop between finishing and inspection. Instead of part measurement being a mere off-line verification operation, it can direct the robot to do the necessary work and provide feedback to achieve higher finishing precision. In this paper, we describe the challenges in closing the loop seamlessly and our approach to resolve them. We present the overall architecture in which the part is measured using a multiple cooperative sensor system, and the robot is directed until the desired finish is obtained. We present details on the use of multi-sensor inspection and corresponding integration of the various components (hardware and software). We validate by application to turbine blades that are used commercially. Utilizing the suggested concept, turbine blade manufacturers will benefit by realizing greatly increased product throughput and reduced cost. The potential for generating scrap is reduced, and two separate, time-consuming operations will be consolidated into a single setup. It will also reduce hardware, footprint, maintenance, and energy costs by their sharing of common components. This concept can be extended to similar closed-loop manufacturing cells with minor modifications. [ABSTRACT FROM AUTHOR]

Purpose. Currently, few studies have presented comprehensive reports on exercise intensity in virtual reality among healthy subjects. The aim of the paper was to evaluate the energy expenditure of young individuals during an active game in virtual reality. Methods. A total of 32 healthy adults, 12 males and 20 females, were examined. Their mean age was 20.6 (± 1.4) years. The average BMI equalled 23.29 (± 2.3) kg/m2. The subjects participated in 15-minute training sessions, with the frequency of 4 sessions weekly, for 2 weeks. Xbox 360® and Kinect® Adventures software were used for the virtual reality training. Energy expenditure expressed in kcal, metabolic equivalent of task (MET), and the number of steps were the primary outcomes. The SenseWear Armband was used to assess energy expenditure. The study applied the Xbox 360 console along with a Kinect motion sensor. Results. During one day of training, the average energy value was 3.7 MET and 46 kcal. During one session, 318 steps were noted. The analysis of all predictors between trainings of each single day did not show any statistically significant difference. Conclusions. Training in virtual reality with the application of the Kinect system provides health benefits and can be an alternative to traditional physical activity. However, 15 minutes of daily training cannot be the only basis for physical activity. [ABSTRACT FROM AUTHOR]

Background: The tracking devices could help measuring the heart rate and energy expenditure and recognizing the user's activity. The calorie measurement is a significant achievement for the fitness tracking and the continuous health monitoring. Methods: In this paper, a combination of an accelerometer and a photoplethysmography (PPG) sensor is implemented to calculate the calories consumed. These sensors were mounted next to each other and then were placed on the ankle and finger by flat cable. The sensed data are transferred via Bluetooth to a smartphone in a serial and real-time manner. An Android App is designed to display the user's health data. The average amount of consumed energy is obtained from the combination of the accelerometer sensor based on the laws of motion and the PPG sensor based on the heart rate data. Results: The designed system is tested on 10 nonathlete males and 10 nonathlete females randomly. By applying thevelet, the value of the acceleration signal variance was reduced from 3.2 to 0.8. The correlation between PPG and pulse oximeter was 0.9. Moreover, the correlation of the accelerometer and treadmill was 0.9. The root mean square error (RMSE) and the P value of the calorie output from PPG and pulse oximeter are 0.53 and 0.008, respectively. The RMSE and the P value of the calories output from the accelerometer and the treadmill are 0.42 and 0.007, respectively. Conclusion: Our device validity and reliability were good by comparing it with a typical smart band, smart watch, and smartphone available in the market. The combined PPG and the accelerometer sensors were compared with the gold standard, the pulse oximeter, and the treadmill. According to the results, there is no significant difference in the values obtained. Therefore, a mobile system is augmented with the wireless accelerometer and PPG that are connected to a smartphone. The system could be carried out with the user at any time and any place. [ABSTRACT FROM AUTHOR]

In recent years, many new ensemble-based time series classification (TSC) algorithms have been proposed. Each of them is significantly more accurate than their predecessors. The Hierarchical Vote Collective of Transformation-based Ensembles (HIVE-COTE) is currently the most accurate TSC algorithm when assessed on the UCR repository. It is a meta-ensemble of 5 state-of-the-art ensemble-based classifiers. The time complexity of HIVE-COTE—particularly for training—is prohibitive for most datasets. There is thus a critical need to speed up the classifiers that compose HIVE-COTE. This paper focuses on speeding up one of its components: Ensembles of Elastic Distances (EE), which is the classifier that leverages on the decades of research into the development of time-dedicated measures. Training EE can be prohibitive for many datasets. For example, it takes a month on the ElectricDevices dataset with 9000 instances. This is because EE needs to cross-validate the hyper-parameters used for the 11 similarity measures it encompasses. In this work, Fast Ensembles of Elastic Distances is proposed to train EE faster. There are two versions to it. The exact version makes it possible to train EE 10 times faster. The approximate version is 40 times faster than EE without significantly impacting the classification accuracy. This translates to being able to train EE on ElectricDevices in 13 h. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach based on Weibull distribution to determine the capacity of wind turbine generators (WTGs) using capacity factor (CF), normalized average power (PN), and the product of CF and PN under different values of tower height and rated wind speed. Five locations for installation of WTG in Taiwan are practically examined. The proposed Weibull distribution is employed to represent probability distribution of wind speed variation, while the important relationships among mean wind speed (MWS), standard deviation of wind speed, and both scale and shape parameters of the Weibull distribution are also derived. The cost of energy (COE) and capital costs of WTG under different tower heights and various locations are also determined. It can be concluded from the simulation results of five installation locations of WTG in Taiwan that suitable values for both shape parameter and scale parameters of Weibull distribution as well as wind turbine capacity are identically important for selecting locations of installing WTG. The scale parameter of Weibull distribution also significantly affects COE, and it is important to determine whether a wind farm is good or not. [ABSTRACT FROM AUTHOR]

Numerous studies have been performed to examine the existence of a relationship between a weak thermogenic potential and the risk of developing obesity. These studies used a large variety of methodological approaches that have frequently revealed a potential physiological vulnerability in obesity-prone individuals. However, from a quantitative standpoint, they have not allowed the demonstration of differences or experimental effects that could explain large variations in energy balance. As discussed in this paper, a definition of adaptive thermogenesis as being a greater than predicted change in energy expenditure in response to changes in energy balance leads to clinically meaningful observations. This is particularly the case in the context of a weight-reducing program in which adaptive changes in thermogenesis can be sufficient to compensate for a prescribed decrease in daily energy intake. This paper also presents evidence suggesting that these thermogenic adaptations might indirectly contribute to the protection of body homeostasis by attenuating the decrease in the dilution space of some lipid-soluble pollutants. [ABSTRACT FROM AUTHOR]

A novel two-phase approach to manage the daily operation of proton exchange membrane (PEM) fuel cells for residential applications is presented in this paper. Conventionally, the performance optimization is carried out offline since it is a time-consuming process and needs high computational capabilities. To simplify the management process and to enable online parameter updating, the paper suggests a new technique using artificial neural networks (ANNs). First, a database is extracted by performing offline optimization processes at different load demands and natural gas and electricity tariffs using a genetic algorithm (GA). Then, the obtained results are used for the offline training and testing of the ANN, which can be used onsite to define the settings of the fuel cell. The tariffs and load demands as inputs of the ANN can be easily updated online to enable the ANN to estimate new optimal or quasioptimal set points after each variation in operating points. The agreement between ANN decisions and optimal values as well as the achieved reduction in operating costs encourage the implementation of the proposed technique to achieve both fast online adaptation of settings and near optimal operating cost. This technique is applicable for different distributed generating units (DGUs), which are expected to spread within the power systems in the near future. [ABSTRACT FROM PUBLISHER]

The author discusses the energetics and biomechanics of terrestrial locomotion in the series of four papers published by C. Richard Taylor. He describes locomotion energetics data and energy cost per stride of locomotion with body size that was published in first and second paper. He also reflects on changes in centre of mass and body size and metabolic data on walking and running gaits in the third and fourth series of paper.

Featured Application: Gravity compensation mechanism can be applied to general surgery for which the human fatigue due to long operation time should be minimized. Stackable mechanism architecture has demonstrated effective gravity-balancing over entire workspaces. Adjustable balancing is required when balancing is broken due to changing the payload at the distal end of a mechanism. In this paper, adjustable balancing of the stackable mechanism for a variable payload is investigated. For this, balancing conditions for three adjustable balancing methods are suggested, and a new balancing method combining a spring and counterweight is considered as an effective means of adjustable balancing for variable payloads. The excellent performance of the system is proven through experiments. Electromyography (EMG) sensors are employed to measure the amount of energy expenditure during the drilling task. It was verified through several tests that an operator holding a drill mounted at the distal end of a stackable arm felt less energy compared to an operator holding the drill directly in free space. The developed balancing arm was successfully applied during a mastoidectomy. A 3-step warning algorithm along with a braking function was found to be effective for safe surgery. [ABSTRACT FROM AUTHOR]

Background: Predicting the energy costs of human travel over snow can be of significant value to the military and other agencies planning work efforts when snow is present. The ability to quantify, and predict, those costs can help planners determine if snow will be a factor in the execution of dismounted tasks and operations. To adjust predictive models for the effect of terrain, and more specifically for surface conditions, on energy costs, terrain coefficients (ƞ) have been developed. The physiological demands of foot travel over snow have been studied previously, and there are well established methods of predicting metabolic costs of locomotion. By applying knowledge gained from prior studies of the effects of terrain and snow, and by leveraging those existing dismounted locomotion models, this paper seeks to outline the steps in developing an improved terrain coefficient (ƞ) for snow to be used in predictive modeling.Methods: Using published data, methods, and a well-informed understanding of the physical elements of terrain, e.g., characterization of snow sinkage (z), this study made adjustments to ƞ-values specific to snow.Results: This review of published metabolic cost methods suggest that an improved ƞ-value could be developed for use with the Pandolf equation, where z = depth (h)*(1 - (snow density (ρ0)/1.186)) and ƞ = 0.0005z3 + 0.0001z2 + 0.1072z + 1.2604.Conclusion: While the complexity of variables related to characteristics of snow, speed of movement, and individuals confound efforts to develop a simple, predictive model, this paper provides data-driven improvements to models that are used to predict the energy costs of dismounted movements over snow. [ABSTRACT FROM AUTHOR]

As an advanced interaction mode, the gesture has been widely used for the human-computer interaction (HCI). The paper proposes a comfort evaluation model based on the mechanical energy expenditure (MEE) and the mechanical efficiency (ME) to predict the comfort of gestures. The proposed comfort evaluation model takes nineteen muscles and seven degrees of freedom into consideration based on the data of muscles and joints and is capable of simulating the MEE and the ME of both static and dynamic gestures. The comfort scores (CSs) can be therefore calculated by normalizing and assigning different decision weights to the MEE and the ME. Compared with the traditional comfort prediction methods based on measurement, on the one hand, the proposed comfort evaluation model makes it possible for providing a quantitative value for the comfort of gestures without using electromyography (EMG) or other measuring devices; on the other hand, from the ergonomic perspective, the results provide an intuitive indicator to predict which act has the higher risk of fatigue or injury for joints and muscles. Experiments are conducted to validate the effectiveness of the proposed model. According to the comparison result among the proposed comfort evaluation model, the model based on the range of motion (ROM) and the model based on the method for movement and gesture assessment (MMGA), a slight difference can be found due to the ignorance of dynamic gestures and the relative kinematic characteristics during the movements of dynamic gestures. Therefore, considering the feedback of perceived effects and gesture recognition rate in HCI, designers can achieve a better optimization for the gesture design by making use of the proposed comfort evaluation model. [ABSTRACT FROM AUTHOR]

Anorexia nervosa (AN) is uncommon as a syndrome, despite widespread dieting or voluntary food restriction, especially among female adolescents. This suggests that restriction of caloric intake might not be the only component driving weight loss in AN. Historical observations and experimental evidence from energy expenditure studies and recordings from movement sensors reviewed in this paper reveal that AN is associated with motor activity levels and with an energy output not significantly different from that in normal-weight healthy age-matched controls. By contrast, other conditions of prolonged caloric under-nutrition are typically associated with loss of energy, slowing of movements and a decrease in self-initiated activity and well-being. Several hypotheses can be inferred from the findings: (a) that long term severe caloric restriction fails in downregulating movements and energy expenditure in AN. (b) Clinically and subjectively observable as mental and physical restlessness and continued motor activity, this restless energy, differing in intensity, seems to serve as the permissive factor for and possibly to drive exercise and hyperactivity in AN. (c) Such restless energy and increased arousal, generated sometime in the course of the weight loss process, appear to enhance the person's self-perception and wellbeing, to heighten proprioception, to intensify body awareness and to improve self-esteem. (d) Restlessness and continued motor activity may constitute a phenotype of AN. The therapeutic value of the concept of an abnormality in the energy regulatory system, likely the result of a host of genetic and epigenetic changes in AN, lies primarily in its heuristic and explanatory power and its potential for disease prevention. Restless energy as a permissive and important component for the development and in the maintenance of AN, does not fundamentally alter treatment, since prolonged food deprivation is the principal causal factor for the development of AN. Re-nutrition within a structured treatment plan, to include individual and family therapy and, if indicated, heat application, remains the most effective symptomatic treatment for AN. Corroboration of the concept of restless activation will require the patient's cooperation and input to identify and capture more precisely the experiences, sensations, and changes that allow the emaciated patient to remain mobile and active. [ABSTRACT FROM AUTHOR]

In this paper, we present a new perspective to design an unpowered exoskeleton for metabolic rate reduction in running. According to our studies on human biomechanics, it was observed that having a torsional spring that applies torque as a linear function of the difference between two hips angles (${d}$ -angle), compared with a local spring which applies torque as a function of hip angle (${h}$ -angle), provides a better condition for hip moment compensation and, consequently, metabolic rate reduction. Accordingly, a new type of unpowered exoskeleton device for realization of this idea was designed, and a prototype of this exoskeleton was constructed. This exoskeleton was tested on 10 healthy active subjects for running at 2.5 m s−1. In this experiment, 8.0 ± 1.5% (mean ± s.e.m.) metabolic rate reduction (compared with the no-exoskeleton case) was achieved. [ABSTRACT FROM AUTHOR]

The metatarsophalangeal (MTP) joints play critical roles in human locomotion. Functional restriction or loss of MTP joints will lead to lower walking speed, poorer walking balance, and more consumed metabolic energy cost compared with normal walking. However, existing foot orthoses are focused on maintaining the movement of the ankle joint, without assisting the MTP joints. In this paper, in order to improve the walking performance of people with lower limb impairments, a wearable powered foot orthosis (WPFO) which has actuated MTP joint is designed and constructed. Preliminary experiments on three nondisabled subjects demonstrated functionality and capabilities of the WPFO to provide correctly timed dorsiflexion and plantar flexion assistance at the MTP joint during walking. These results also suggest that the WPFO could offer promise in certain rehabilitation applications and clinical treatment. [ABSTRACT FROM AUTHOR]

Background: The widely accepted definition of sedentary behaviour [SB] refers to any waking behaviour characterized by an energy expenditure ≤1.5 metabolic equivalents [METs] while in a sitting or reclining posture. At present, there is no single field-based device which objectively measures sleep, posture and activity intensity simultaneously. The aim of this study was to develop a novel integrative procedure [INT] to combine information from two validated activity monitors on sleep, activity intensity and posture, the three key dimensions of SB.Methods: Participants in this analysis were initially recruited from a series of three studies conducted between December 2014 and June 2016 at the University of Leeds. Sixty-three female participants aged 37.1 (13.6) years with a body mass index of 29.6 (4.7) kg/m2 were continuously monitored for 5-7 days with the SenseWear Armband [SWA] (sleep and activity intensity) and the activPAL [AP] (posture). Data from both activity monitors were analysed separately and integrated resulting in three measures of sedentary time. Differences in Sedentary time between the three measurement methods were assessed as well as how well the three measures correlated.Results: The three measures of sedentary time were positively correlated, with the weakest relationship between SEDSWA (awake and <1.5 METs) and SEDAP (awake and sitting/lying posture) [r(61) = .37,p = .003], followed by SEDSWA and SEDINT (awake, <1.5 METs and sitting/lying posture) [r(61) = .58,p < .001], and the strongest relationship was between SEDAP and SEDINT [r(61) = .91,p < .001]. There was a significant difference between the three measures of sedentary time [F(1.18,73.15) = 104.70,p < .001]. Post-hoc tests revealed all three methods differed significantly from each other [p < .001]. SEDSWA resulted in the most sedentary time 11.74 (1.60) hours/day, followed by SEDAP 10.16 (1.75) hours/day, and SEDINT 9.10 (1.67) hours/day. Weekday and weekend day sedentary time did not differ for any of the measurement methods [p = .04-.25].Conclusion: Information from two validated activity monitors was combined to obtain an objective measure of free-living SB based on posture and activity intensity during waking hours. The amount of sedentary time accumulated varied according to the definition of SB and its measurement. The novel data integration and processing procedures presented in this paper represents an opportunity to investigate whether different components of SB are differentially related to health end points. [ABSTRACT FROM AUTHOR]

Introduction: Lifestyle management, including appropriate modifications of nutrition, exercise, and medication behaviors, is essential for optimal glycemic control. The absence of appropriate monitoring methods to validate the lifestyle change may hinder the modification and continuation of behaviors. In this study, we evaluated whether once-weekly glycated albumin (GA) measurement received via a smartphone application could improve glycemia management in patients with type 2 diabetes mellitus by supporting self-review and modification of lifestyle behaviors. Methods: This open-label, randomized controlled, single-center study in Japan with an 8-week intervention period was conducted in individuals with type 2 diabetes mellitus and HbA1c levels between 7.0 and 9.0% (53‒75 mmol/mol). The intervention was once-weekly home monitoring of GA with a daily self-review of lifestyle behaviors using a smartphone application, in addition to conventional treatment. Results: A total of 98 participants (72.0% males; age 63.2 ± 11.4 years; HbA1c 7.39 ± 0.39% [57.3 ± 4.3 mmol/mol]) were randomly assigned to the intervention or control group. Significant decreases of the GA and HbA1c levels from the baseline to the last observation day were observed in the intervention group (− 1.71 ± 1.37% [− 39.1 ± 31.3 mmol/mol] and − 0.32 ± 0.32% [− 3.5 ± 3.5 mmol/mol], respectively). Significant decreases of the body weight, waist circumference, and caloric expenditure (p < 0.0001 and p = 0.0003, p = 0.0346, respectively), but not of the caloric intake (p = 0.678), were also observed in the intervention group as compared with the control group. Conclusions: Self-review of lifestyle behaviors in combination with once-weekly GA home testing received via a smartphone application might potentially benefit glycemic management in people with type 2 diabetes mellitus. Trial Registration: jRCTs042220048. [ABSTRACT FROM AUTHOR]

Metabolic cost plays a critical role in gait biomechanics, particularly in rehabilitation. Several factors influence metabolic cost during walking. Therefore, this study aimed to examine the relationship between metabolic cost and muscle activity, focusing on the frequency of EMG signals during walking. We recruited nine participants (five male and four female, age range 20–48 years) who walked for four minutes at six different speeds (ranging from 1.8 to 5.9 mph). EMG data were collected from the dominant lower leg muscles, specifically the lateral gastrocnemius (GAS-L) and the anterior tibialis (AT). Oxygen respiration was measured using open-circuit spirometry. Energy expenditure was estimated as the cost of transport (COT). The EMG data were analyzed using frequency domain features, such as the area under the curve of power spectral density (PSD-AUC) and the maximal distance between two points before and after the peak of the power spectral density curve (MDPSD). The results indicated that PSD-AUC is a better measure than MDPSD for understanding the relationship between activation frequency and COT. PSD-AUC demonstrated an increasing curvilinear trend (R2 = 0.93 and 0.77, second order polynomial fit), but the AT displayed higher variability. MDPSD exhibited more nonlinearity (R2 = 0.17–28, second order polynomial fit), but MDPSD demonstrated statistically significant differences (p < 0.05, t-test independent) in frequency between the GAS-L (64–237 Hz) and AT (114–287 Hz) during slow walking. Additionally, the relationship between COT and PSD-AUC revealed a U-shaped curve, suggesting that high COT is a function of both active and passive dynamics during walking. These findings will be valuable in rehabilitating individuals who suffer from gait-related disorders, especially those related to muscle inefficiency. [ABSTRACT FROM AUTHOR]

The need to improve power management in Grids is becoming essential for environmental-ecological and economical reasons. Applications need more computational power and power costs are increasing. This paper studies the benefits in power consumption that come from the use of power-saving modern processors that can adjust their operating frequency depending on the workload, in a real-time 2-level grid system. We propose resource scheduling policies based on energy consumption criteria. A simulation model is used to evaluate performance of these policies at the grid level and at the local level. Our experimental results show around 30% savings in processors' power consumption while maintaining performance at satisfactory levels. [ABSTRACT FROM AUTHOR]

This paper explores further the ''behavioral homeostasis theory'' (BHT) regarding the evolutionary significance for organism survival of the two simple non-associative rapidly learned behaviors of habituation and sensitization. The BHT postulates that the evolutionary function of habituation and sensitization throughout phylogeny is to rapidly maximize an organism's overall readiness to cope with new stimuli and to minimize unnecessary energy expenditure. These behaviors have survived with remarkable similarity throughout phylogeny from aneural protozoa to humans. The concept of ''behavioral homeostasis'' emphasizes that the homeostatic process is more than just maintaining internal equilibrium in the face of changing internal and external conditions. It emphasizes the rapid internal and external effector system changes that occur to optimize organism readiness to cope with any new external stimulus situation. Truly life-threatening stimuli elicit instinctive behavior such as fight, flee, or hide. If the stimulus is not life-threatening, the organism rapidly learns to adjust to an appropriate level of overall responsiveness over stimulus repetitions. The rapid asymptotic level approached by those who decrease their overall responsiveness to the second stimulus (habituaters) and those who increase their overall responsiveness to an identical second stimulus (sensitizers) not only optimizes readiness to cope with any new stimulus situation but also reduces unnecessary energy expenditure. This paper is based on a retrospective analysis of data from 4 effector system responses to eight repetitive tone stimuli in adult human males. The effector systems include the galvanic skin response, finger pulse volume, muscle frontalis and heart rate. The new information provides the basis for further exploration of the BHT including new predictions and proposed relatively simple experiments to test them. [ABSTRACT FROM AUTHOR]

Background: This paper examines the cost and benefits, both financial and environmental, of two leading forms of solar power generation, grid-tied photovoltaic cells and Dish Stirling Systems, using conventional carbon-based fuel as a benchmark. Methods: First we define how these solar technologies will be implemented and why. Then we delineate a model city and its characteristics, which will be used to test the two methods of solar-powered electric distribution. Then we set the constraining assumptions for each technology, which serve as parameters for our calculations. Finally, we calculate the present value of the total cost of conventional energy needed to power our model city and use this as a benchmark when analyzing both solar models' benefits and costs. Results: The preeminent form of distributed electricity generation, grid-tied photovoltaic cells under net-metering, allow individual homeowners a degree of electric self-sufficiency while often turning a profit. However, substantial subsidies are required to make the investment sensible. Meanwhile, large dish Stirling engine installations have a significantly higher potential rate of return, but face a number of pragmatic limitations. Conclusions: This paper concludes that both technologies are a sensible investment for consumers, but given that the dish Stirling consumer receives 6.37 dollars per watt while the home photovoltaic system consumer receives between 0.9 and 1.70 dollars per watt, the former appears to be a superior option. Despite the large investment, this paper deduces that it is far more feasible to get few strong investors to develop a solar farm of this magnitude, than to get 150,000 households to install photovoltaic arrays in their roofs. Potential implications of the solar farm construction include an environmental impact given the size of land require for this endeavour. However, the positive aspects, which include a large CO2 emission reduction aggregated over the lifespan of the farm, outweigh any minor concerns or potential externalities. [ABSTRACT FROM AUTHOR]

This paper addresses a transmission energy problem for distributed (or decentralized) estimation in multihop wireless sensor networks (WSN). A primary advantage of distributed estimation is its energy efficiency when compared to centralized estimation. Two distributed estimation schemes are considered in this paper: progressive estimation and consensus estimation. We develop a generalized energy planning algorithm for a progressive estimation method which exploits routing tree and channel state information. We also analyze the energy cost for a consensus estimation method used in broadcast multihop WSN. We demonstrate by analysis and simulation that, subject to an equivalent performance, the total energy cost for consensus estimation is typically much higher than that for progressive estimation, but the peak energy for the former can be less than that for the latter. [ABSTRACT FROM PUBLISHER]

The feasibility study of a power system is aimed at determining whether the system can adequately satisfy the load. The study will usually include other purposes, such as estimating the life-cycle cost of the system. This paper summarizes the main capabilities of current software packages for feasibility analysis of distributed energy resources. The document presents a short description of models, dispatch strategies, and economic indicators implemented in some packages. The test cases included in this paper will illustrate the scope of a feasibility study considering off-grid and grid-connected distributed resources. [ABSTRACT FROM AUTHOR]

The energy consumption in the world is increasing greatly owing to the growing population, and to increasing energy consumption per capita. This high energy consumption is associated with a high life quality. Due to this fact, and to the energy price and availability and to the potential threat of global climate changes, there is a great motivation to use energy from renewable sources such as solar energy. Jordan is a developing non-oil production country and its energy needs are imported from abroad as oil and petroleum products. On the other hand, Jordan has an abundance amount of solar radiation 300 days a year. Photovoltaic modules provides safe, reliable, maintenance-free, without noise, and environmentally friendly source of power. This paper evaluates the performance of different solar modules in semi arid climate as in Jordanian. An experiment to investigate the performance of two photovoltaic modules is conducted at different times of the year. The measured parameters in this paper are: output open circuit voltage and short circuit current from the PV modules, ambient temperature and solar intensity. The relationship between the performance and the efficiency of monos crystalline PV and multi crystalline PV is measured in this experiment. The performance value of the PV solar module is identified and compared with the output values supplied by the producer of the PV modules and with other PV models. [ABSTRACT FROM AUTHOR]

Keen interest in the development and utilization of wind-based distributed generations (DGs) has been currently observed worldwide for several reasons. Among those is controlling the emission of environmentally harmful substances, limiting the growth in energy costs associated with the use of conventional energy sources and encouraging the independent power producers for participation in the electricity market system. One of the most important issues is to quantitatively assess the impact of such type of DGs on the distribution system reliability. This paper presents a probabilistic technique to evaluate the distribution system reliability utilizing segmentation concept and a novel constrained Grey predictor technique for wind speed profile estimation. [ABSTRACT FROM AUTHOR]

Large fluctuations in energy prices have been a distinguishing characteristic of the U.S. economy since the 1970s. Turmoil in the Middle East, rising energy prices in the United States, and evidence of global warming recently have reignited interest in the link between energy prices and economic performance. This paper addresses a number of the key issues in this debate: What are energy price shocks and where do they come from? How responsive is energy demand to changes in energy prices? How do consumer's expenditure patterns evolve in response to energy price shocks? How do energy price shocks affect U.S. real output, inflation, and stock prices? Why do energy price increases seem to cause recessions but energy price decreases do not seem to cause expansions? Why has there been a surge in the price of oil in recent years? Why has this new energy price shock not caused a recession so far? Have the effects of energy price shocks waned since the 1980s and, if so, why? As the paper demonstrates, it is critical to account for the endogeneity of energy prices and to differentiate between the effects of demand and supply shocks in energy markets when answering these questions. [ABSTRACT FROM AUTHOR]

By the introduction of competitive supply, modern electric utilities are forced to operate their systems closer to their security limits. Under such fragile conditions, any disturbance could endanger system security and lead to system collapse. There is, therefore, a need to develop new methods which could evaluate optimal scheduling of operating reserve and forewarn the system operators to take necessary preventive actions in case need arises. An effective method is proposed in this paper to optimally allocate spinning reserve based on a well-being model. The method used in conventional well-being framework for classifying power system comfort zone into healthy and marginal states is initially revised. The optimal value of health index and system spinning reserve requirements are then evaluated on the basis of a trade off between the total cost of spinning reserve and the expected cost of energy not served. The effectiveness of the proposed method is examined using the IEEE-RTS. [ABSTRACT FROM AUTHOR]