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The aim of the present work is to investigate the effects of Renewable Distributed Generators (RDGs) on the competitive electricity markets. First, the optimal size of RDG units working at unity power factor is obtained using Particle Swarm Optimization (PSO). The optimal sizing is obtained based on the investment costs of the RDGs and conventional generators. Secondly, the wheeling costs are evaluated before and after the integration of RDGs in the power system network. Different approaches in MW-Mile method are utilized in obtaining the wheeling charges in the present work. The suggested method of obtaining optimal sizing of RDGs is explored on IEEE 30 bus test system for the appropriate feasibility check. Simulation results are evaluated to show the applicability of the proposed methodology in terms of wheeling charges for the transaction of 50 MW. The results reveal that intimated method can aid the ISO in evaluating the wheeling costs for a transaction of 50 MW. Wheeling charges evaluated are compared among without DG case, with 60 MW DG case and optimum capacity DG case.

In general, the optimal power transaction is expressed using a total operating cost for the joined generating units while the power delivery is dispatched using a power schedule commitment. These financial aspect and power participation are used to measure all technical processes during providing and selling energy to customers. Moreover, the power delivery to the energy user is also constrained by transmission capabilities associated with transmission charges at all operators. To cover this penetration, Artificial Salmon Tracking Algorithm is used to find out the optimal power wheeling composition. Results show that the total minimum cost depends on technical factor schemes. Various combined power portions also give numerical implications on the economic operation, power production, and power transaction. In particular, generated powers lead to the total cost and the total pollutant discharge for each generating unit. Power delivery on the system conducts to the delivery fee as the transmission use of system charges.

Industrial estates in Thailand, which are usually connected to distribution systems, allow power producers to directly negotiate with their own customers. Therefore, distribution utilities have to calculate wheeling charges with fairness and transparency. This paper proposes a concept of wheeling charge calculation based on “power flow based MW-Mile method” with the consideration of differentiation of line flow magnitude before and after the power transaction. The results show that the proposed concept computes the different wheeling charge against existing power flow based MW-Mile method and can reflect an increase or decrease of line flow due to power transaction.

On December 18th 2017, an all-time high level of power delivery of 5.2GW was achieved in Nigeria, providing a new data-point on the proven physical wheeling capability of the system and prompting discussion on how to exceed the record. This paper presents statistical analysis based on the first-ever investigation of hourly, spatially disaggregated load and generation data from Nigeria over a full year, and load flow analysis based on the record performance day. The paper also explains relevant features of the local power sector. The analysis quantifies how performance has improved in 2017, but also how differing operational choices of the parties involved, and physical distribution system technical limitations tend to limit the increase of delivered energy. Physical transmission system limits suggest a regional voltage limit would be reached at 5.45GW, but that by changing distributed power, the total load could be extended to 5.7GW before thermal limits are reached on some infrastructure.

The paper includes examples of application of a handheld TDR meter in terramechanical studies. The examples include monitoring of soil moisture during off-road vehicle mobility tests, determination of snow density before and after wheeling of a snow grooming machine and snow stress measurements as well as monitoring of turf moisture on a grassy airfield toward analysis and prediction of safe and efficient flight operation (takeoff and landing).

In the demand response(DR) paradigm, dynamic pricing or real-time pricing (RTP) have been proposed as one of the widely accepted approaches to efficiently adjust and shift customers' consumption of energy away from peak periods, thus increasing system efficiency and stability. An appropriate price signal can provide an efficient economic incentive for electricity customers to consume their energy rationally. Various dynamic pricing schemes which aim to deliver proper price signal to electricity users have been widely investigated in the past decades. However, most of the analysis and results in existing literature related to dynamic pricing only valid when energy price is a linear function of the generation plant or extracted from the existed day ahead wholesale market. In practice, transmission and wheeling prices are also vital components of the electricity price since the wheeling utilities are accepted to receive appropriate revenue to cover the cost of transmission facilities and associated maintenance cost. In this paper, an innovative dynamic pricing framework is proposed for exploring the optimum price signal with the global consideration of wholesale market, benefits of power suppliers and customers' behaviours. The proposed framework is tested on IEEE 6 bus test system with a network operator and an electricity supplier serving multiple customers.

This paper is an enquiry into the role of State policies in influencing wind installed capacity. The paper studies the impact of policies on deployment of wind potential across the States of India over two decades. Aggregate indices are computed for each of the seven wind resourceful States of India indicating attractiveness for installed capacity of wind energy. For computing the indices, four policies, Feed-in-Tariff, Renewable Purchase Obligation, Banking facility, and Wheeling charges are considered. Panel data techniques are then employed to investigate the impact of the policy differences on wind potential deployment over the 19 year period (1993–2012) after controlling for three State-specific factors. The controlling factors include per-capita income of the State, power deficit, and ratio of installed capacity of wind to geographic potential indicating unmet capacity. The results show that that policy index positively impacts wind deployment whether control variables are included or not. Moreover, the control factors like the per-capita income of the State and unmet capacity have positive influence over the investment in wind energy.

Restructured electric market environment allows the power wheeling transactions between the power producers and customers to meet the growing load demand. This will lead to the possible of congestion in the transmission lines. The possible contingencies of power components further worsen the scenario. This paper describes the methodology for the identification of critical transmission line by computing the real power and reactive power performance indices. It also demonstrates the importance of fuzzy logic technique used to rank the transmission lines according to the severity and demonstrated on IEEE-30 bus system.

In a deregulated environment of the power market, in order to lower their energy price and guarantee the stability of the power network, appropriate transmission lines have to be considered for electricity generators to sell their energy to the end users. This paper proposes a game-theoretic power transmission scheduling for multiple generators to lower their wheeling cost. Based on the embedded cost method, a wheeling cost model consisting of congestion cost, cost of losses and cost of transmission capacity is presented. By assuming each generator behaves in a selfish and rational way, the competition among the multiple generators is formulated as a non-cooperative game, where the players are the generators and the strategies are their daily schedules of power transmission. We will prove that there exists at least one pure-strategy Nash equilibrium of the formulated power transmission game. Moreover, a distributed algorithm will be provided to realize the optimization in terms of minimizing the wheeling cost. Finally, simulations were performed and discussed to verify the feasibility and effectiveness of the proposed non-cooperative game approach for the generators in a deregulated environment.

Reports of various committees set up to review the 2003 North American major power outages pointed out that a major exacerbating factor has been lack of situational awareness by power system operators. To improve reactive power compensation and contribute to the mitigation of power outages associated with the present near-limit operated commercialized grid, a bus voltage stability (BVS) index based reactive power compensation scheme has been developed. BVS index is a hybrid voltage stability computation model involving the two machine modeled L-index and a complex power Π -transmission line structure modeled Ls-index developed by the authors. The current regional wheeling of power across transmission distance far beyond the two machine model has necessitated the development of a novel Ls-index model suitable for long lines. The composite scheme was then incorporated into Newton–Raphson’s (N–R) power flow which encompasses multiple shunt devices (multi-shunt). This arrangement provided a knowledge based system for power system monitoring. Results obtained from applying the developed models and schemes in the IEEE 300 bus system with zoning and under varying operating conditions showed the system’s capability to provide improved system monitoring and optimal compensation based on availability.

Crop residues may partially dissipate applied loads and reduce soil compaction. We evaluated the effect of corn residue on energy-applied dissipation during wheeling. The experiment consisted of a preliminary laboratory test and a confirmatory field test on a Paleaudalf soil. In the laboratory, an adapted Proctor test was performed with three energy levels, with and without corn residue. Field treatments consisted of three 5.1 Mg tractor wheeling intensities (0, 2, and 6), with and without 12 Mg ha(-1) corn residue on the soil surface. Corn residue on the soil surface reduced soil bulk density in the adapted Proctor test. By applying energy of 52.6 kN m m(-3) , soil dissipated 2.98% of applied energy, whereas with 175.4 kN m m(-3) a dissipation of 8.60% was obtained. This result confirms the hypothesis that surface mulch absorbs part of the compaction effort. Residue effects on soil compaction observed in the adapted Proctor test was not replicated under subsoiled soil field conditions, because of differences in applied pressure and soil conditions (structure, moisture and volume confinement). Nevertheless, this negative result does not mean that straw has no effect in the field. Such effects should be measured via stress transmission and compared to soil load-bearing capacity, rather than on bulk deformations. Wheeling by heavy tractor on subsoiled soil increased compaction, independently of surface residue. Two wheelings produced a significantly increase, but six wheelings did not further increase compaction. Reduced traffic intensity on recently tilled soil is necessary to minimize soil compaction, since traffic intensity show a greater effect than surface mulch on soil protection from excessive compaction. © 2015 Society of Chemical Industry.

Cross-sectional.To determine the relationships between (1) wheeling parameters using the SmartWheel Clinical Protocol (SCP) and wheelchair skills (wheelchair skills test 4.1 (WST)) and (2) push effectiveness (m per push) and the WST, among individuals with spinal cord injury.Biomechanics Laboratory, Canada.Sixteen adults and eight children participated in this study. Multiple regression analyses were used to determine significant SCP predictors (that is, weight-normalised peak force, speed, push frequency and mechanical effectiveness) of WST score. To determine relationships between push effectiveness and WST scores, Pearson's correlations were calculated.SCP-TILE: speed and mechanical effectiveness explained 36% of the variance in the WST score. SCP-RAMP and SCP-CARPET: speed explained 58% and 37% of the variance in the WST score, respectively. Push effectiveness was significantly correlated with the WST score on all three surfaces (tile, ramp and carpet).Wheeling speed was a significant predictor of the WST score for all surfaces tested. Regression analyses demonstrated that SCP-RAMP had the strongest relationship with WST score. Therefore, when time is restricted, the SCP-RAMP may be the most predictive test and speed may be the most useful variable to evaluate. However, the authors do not believe that one single variable should ever replace a full assessment of skills.

PV systems, as one type of distributed generation, have been popularly applied to residential and commercial power supply systems for compensating grid electricity consumption. Schemes for sharing PV power within LV distribution networks have also begun to develop, with the aim to more widely spread the benefits of utilizing localized renewable-generated electricity. Consequently, to utilize the local LV distribution network, there is an argument that customers (both small scale generators and consumers) should pay a ‘wheeling charge’ to utilities for grid services related to the transport of energy, similar to their transmission counterparts. This paper presents some of the existing issues related to implementing a ‘wheeling charge’ for network services raised in the process of sharing locally generated PV power in a LV distribution system. Two methodologies: ‘generation matrix’, based on proportional sharing principle; and ‘MW-Mile’, based on network losses, have been combined to cover the economic operation and tracing of energy supplied by a PV generator and transported through the local LV distribution network. An evaluation of the potential costs of using the LV distribution network including daily PV output and building load demand is provided, utilising a case study.

Direct power purchase by large consumers is a good attempt to adjust the power price by market means, which is in favor of exploring a reasonable price formation mechanism and promotes the establishment of an open electricity market. To make the wheeling price and power loss minimum as the target, the paper presents a method based on the flow tracing, tracing the source of large power users, establishing the power grid optimization scheduling model considering the direct power purchase by large consumers. This paper simulates and analyzes the power grid optimization scheduling strategy under different numbers of large consumers in IEEE 30-bus system, the results demonstrate that the model presented can achieve comprehensive optimization of power loss and wheeling price satisfying the requirements of large consumers.

In general, manual wheelchairs are designed with a fixed frame, which is not optimal for every situation. Adjustable on the fly seating allow users to rapidly adapt their wheelchair configuration to suit different tasks. These changes move the center of gravity (CoG) of the system, altering the wheelchair stability and maneuverability. To assess these changes, a computer simulation of a manual wheelchair was created with adjustable seat, backrest, rear axle position and user position, and validated with experimental testing. The stability of the wheelchair was most affected by the position of the rear axle, but adjustments to the backrest and seat angles also result in stability improvements that could be used when wheeling in the community. These findings describe the most influential parameters for wheelchair stability and maneuverability, as well as provide quantitative guidelines for the use of manual wheelchairs with on the fly adjustable seats.

Mobile animal groups provide some of the most compelling examples of self-organization in the natural world. While field observations of songbird flocks wheeling in the sky or anchovy schools fleeing from predators have inspired considerable interest in the mechanics of collective motion, the challenge of simultaneously monitoring multiple animals in the field has historically limited our capacity to study collective behaviour of wild animal groups with precision. However, recent technological advancements now present exciting opportunities to overcome many of these limitations. Here we review existing methods used to collect data on the movements and interactions of multiple animals in a natural setting. We then survey emerging technologies that are poised to revolutionize the study of collective animal behaviour by extending the spatial and temporal scales of inquiry, increasing data volume and quality, and expediting the post-processing of raw data. This article is part of the theme issue ‘Collective movement ecology’.

The method of estimating transmission costs can be divided into two groups i.e. methods that do not require the calculation of power flow or Network-Based Methods and methods based on the calculation of power flow. The first methods include Postage Stamp Method and Contract Path Method. And the second are MW-Mile Method, MVA-Mile Method, Current Base Method etc in this paper three methods (MW-Mile Method, MVA-Mile Method, Current Base Method) are applied for calculating the allocation cost of transmission in Java Bali interconnection system.

This article formulates the new unified interpretation of the analysis of electromagnetic processes in the autonomous (usually resonant) inverters with power circuits having a serial RLC configuration either with or without free wheeling diodes. On this basis, generalized models of resonant inverters with and without reverse diodes are proposed. On this basis the novel compendious relationships between the most important internal inverter parameters are given. With these models, various inverter operating modes were investigated to search for optimal parameters with a defined target function. The whole processed information helps for good understanding and for organizing intelligent design, measurement and control of the inverters for technological applications (induction heating).

With the increasing penetration of renewable energy in power systems, fluctuation of renewable energy power plants has great influence on stability of the system, and renewable power curtailment is also becoming more and more serious due to the insufficient consumptive ability of local power grid. In order to maximize the utilization of renewable energy, this paper focuses on the generation scheduling optimization for a wind-solar-thermal hybrid system considering that the produced energy will be transmitted over a long distance to satisfy the demands of the receiving end system through ultra-high voltage (UHV) transmission lines. Accordingly, a bilevel optimization based on a non-cooperative game method is proposed to maximize the profit of power plants in the hybrid system. Users in the receiving end system are at the lower level of the bilevel programming, and power plants in the transmitting end system are at the upper level. Competitive behavior among power plants is formulated as a non-cooperative game and the profit of power plant is scheduled by adjusting generation and bidding strategies in both day-ahead markets and intraday markets. In addition, generation cost, wheeling cost, and carbon emissions are all considered in the non-cooperative game model. Moreover, a distributed algorithm is presented to obtain the generalized Nash equilibrium solution, which realizes the optimization in terms of maximizing profit. Finally, several simulations are implemented and analyzed to verify the effectiveness of the proposed optimization method.

In this paper, we present the design, modeling, and experimentation of a miniature jumping robot that utilizes Nitinol (NiTi) wires to store potential energy for the jump. NiTi wires were selected as a superior option to other energy storage medium (e.g., springs, carbon fiber) as they provide large deformations without breaking. Utilizing this option allows for the ultimate goal of designing a hybrid wheeling and jumping robot to be reached. The modeling of NiTi wires to predict the jumping performance is not trivial, owing to NiTi's nonlinear properties. Therefore, we develop mathematical models by considering the nonlinearity as well as asymmetric loading responses to capture the force, geometry, and energy during the energy-charge process. With the designed robot, the predicted jumping performance is close to the experimental results, verifying the proposed modeling methods. The robot has a wide range of applications from search and rescue, environment monitoring, to surveillance. Moreover, other systems that leverage the NiTi's super elasticity to store energy can use the developed mathematical model for NiTi wires.

With rapid development of renewable energy, especially wind and solar energy, long distance transmission will be the fundamental way for new energy consumption because of the insufficient consumptive ability of local grid. This paper proposed a wind-solar-thermal hybrid system long distance consumption by ultra-high voltage (UHV) transmission lines, which not only make full use of the complementary nature of wind and solar energy in time and region, but also take advantage of good stability of thermal power plant to improve system reliability. A bilevel optimization based on non-cooperative game method was utilized to maximize profit of power plants by changing bidding strategies, where power plants in the transmitting end system are at the upper level and receiving end system are at the lower level. Besides, cost model considering with wheeling cost, carbon emissions cost and government subsidies was presented. Finally, several simulations were implemented and used to verify the feasibility of the non-cooperative game based bilevel optimization method.

In nature, a variety of limbless locomotion patterns flourish, from the small or basic life forms (Escherichia coli, amoebae, etc.) to the large or intelligent creatures (e.g., slugs, starfishes, earthworms, octopuses, jellyfishes, and snakes). Many bioinspired soft robots based on locomotion have been developed in the past few decades. In this work, based on the kinematics and dynamics of two representative locomotion modes (i.e., worm-like crawling and snake-like slithering), we propose a broad set of innovative designs for soft mobile robots through simple mechanical principles. Inspired by and going beyond the existing biological systems, these designs include 1-D (dimensional), 2-D, and 3-D robotic locomotion patterns enabled by the simple actuation of continuous beams. We report herein over 20 locomotion modes achieving various locomotion functions, including crawling, rising, running, creeping, squirming, slithering, swimming, jumping, turning, turning over, helix rolling, wheeling, etc. Some are able to reach high speed, high efficiency, and overcome obstacles. All these locomotion strategies and functions can be integrated into a simple beam model. The proposed simple and robust models are adaptive for severe and complex environments. These elegant designs for diverse robotic locomotion patterns are expected to underpin future deployments of soft robots and to inspire a series of advanced designs.

East Africa Power Pool (EAPP) is a proposed regional interconnection for centralizing energy resources and facilitating power wheeling between the Eastern Africa geographical areas. Synchronous tie lines have been used in the established interconnections so far. However, asynchronous interconnection is preferred since there high Renewable Energy (RE) penetration in the EAPP. HVDC technology, particularly multi terminal DC (MTDC) is a good example of such links as it provides loose coupling between the interconnected power systems. This has several economic, environmental and security-stability merits as compared to the traditional HVAC tie lines. The Kenya-Ethiopia HVDC Bipolar is supposed to provide a loose coupling between the two countries. The same technology can be reproduced in the EAPP so as to achieve a dynamic regional interconnection. Thus, a 10-Area system with 18 MTDC tie lines is considered where each area represents a Transmission System Operator (TSO) for each country. In this paper, a multi area multi objective economic dispatch (MAMODED) with RE and Emissions is formulated where MTDC constraints have been included for the first time in the EAPP. Review of EAPP and MAMODED with RE, merits of MTDC interconnection, RE penetration in EAPP, and MTDC tie line power flows are also presented.

Solar energy is a key component of cities’ climate mitigation and energy security plans, due to its ease of installation & operation and drastic decline in costs.In Bengaluru, residential, commercial and industrial (C & I) consumers contributed to around 85% of the electricity consumption and resultant emissions during 2014 and 2015. What are the options for these consumers within the ambit of current policies to procure solar power? Are changes required in these policies to scale up the adoption of solar power?WRI India has explored two possible options – off-site and on-site procurement of solar energy.On-site procurementIn 2013, net-metering which allows export of excess power to the grid was not available in Bengaluru. This, in addition to expensive electricity storage options meant that the complete potential of an on-site solar plant could not be realized.WRII has found that net-metering regulations for rooftop solar projects in Karnataka, introduced in November 2014, were met with moderate success among C & I consumers. The adoption among residential consumers was slow due to information gaps about financial parameters, net-metering procedures and credible installers.On May 2, 2016 gross metering scheme is introduced for both categories of consumers. WRII intends to look into the effectiveness of the new scheme.Off-site solar procurementGrid-connected solar power projects in Karnataka, commissioned before 31 March 2018, were exempted from payment of wheeling, banking charges and cross subsidy surcharge for the first 10 years for sale to 3rd party customers.Since the typical payback period for a utility scale solar project is around 7 years, this order provided long term clarity for investors, solar project developers and consumers. For certain categories of consumers (commercial), the exemption meant that solar energy became more viable. However, challenges in procuring land and bottlenecks in power evacuation, may delay the large scale deployment of solar projects to the latter half of 2016.

Nonvolatile latches are increasingly popular with the advent of IoT design. We study the yield energy tradeoff of the backup mechanism of an STT-MTJ based nonvolatile latch. For the yield analysis, we rely on Hicks and Wheeling methodology for multi-cone radial sampling for the purpose of rare fail estimation. Yield is shown to be delimited by the Parallel-to-AntiParallel magnetic angle transitions. To accommodate for the slower cells, we note an increase in the average energy requirements for the backup mechanism. Simulations indicate an increase of 10%–40% for the average energy requirements to achieve an ideal yield requirement close to 99% for different number of components.

No-till has many environmental advantages, but concerns are growing about vehicle-induced topsoil compaction limiting crop growth. We performed a wheeling experiment in a long-term no-till field on an Oxisol with sandy loam texture. The objectives were to measure changes in soil bulk density and corresponding impacts on the least limiting water range (LLWR) due to passage of a maize harvester, and to compare bulk density and LLWR measurements with values simulated using the SoilFlex-LLWR soil compaction model. Soil cores were sampled before and after wheeling, for bulk density measurements and to determine LLWR. Simulated increase in bulk density due to vehicle wheeling agreed well with measurements. However, simulated LLWR and its decrease with compaction were inaccurate. This was ascribed to the pedo-transfer function used in SoilFlex-LLWR to estimate LLWR parameters, which was developed based on data from conventionally tilled sugarcane fields, whereas our site was a long-term no-till soil under a wheat/soybean–maize/black oats rotation. Our measurements showed that LLWR was strongly restricted by soil penetration resistance, which was not captured by the pedo-transfer function incorporated in SoilFlex-LLWR. For better prediction of LLWR, we recommend development of specific pedo-transfer functions or of mechanistic models that can be incorporated in SoilFlex-LLWR.

This paper defines flow control algorithms for loop flow cancellation based on the allocation and tracing of bilateral transactions and loop flows. In Part I of this paper, we have shown that the main difference between transportation and electrical networks is caused by the existence of loop flows. We have introduced a distributed framework for the modeling and tracing of bilateral transactions and the corresponding loop flows. Its zooming-out capability provides a valuable mechanism for representing external (inter-area) loop flows based on simplified topologies of individual areas. The tracing information accurately allocates bilateral transactions with associated contract paths to line flows and loop flows. Furthermore, this information can be used for determining the set points of control equipment so that loop flows are minimized. In this framework, phase angle regulators (PARs), commonly used for line flow control, are represented through their effects on loop flows. We define sufficient conditions for achieving complete loop flow cancellation. A new distributed algorithm for determining PAR set points in a coordinated way without revealing operating conditions of individual areas is introduced in this part. Finally, complete loop flow cancellation and the distributed algorithm for finding PAR set points are demonstrated in the Reliability Test System (RTS) 96-bus system with wheeling loop flows.

As the policy discussions of historic preservation have become complicated in recent years, the advocacy for the use of heritage is now even more important, and the number of coalitions for promoting the economic value of heritage has been on the rise. This research provides a historical view of the development of advocacy coalition networks that actively pursue the benefits of heritage resources. Through this context, the article then examines a case study of the Wheeling National Heritage Area. The case exemplifies the framework of how coalition networks can provide the structure necessary to push preservation policy in government.

Cross-sectional study.To measure the reproducibility and responsiveness of heart rate indexes in measuring energy expenditure during wheelchair locomotion of adults with spinal cord injury (SCI).SARAH Rehabilitation Hospital Network-Brasilia, Brazil.The study consecutively enrolled 35 individuals with SCI. Volunteers propelled their wheelchairs at a self-selected and comfortable velocity around a circular track. The first assessment day was a responsiveness study, in which three tests were performed, with the wheelchair weight increased randomly during the last two tests. On the second assessment day, the test was conducted without extra weight (that is, baseline conditions) for reproducibility analyses.All indexes demonstrated reproducibility on all statistical analyses. The Propulsion Cardiac Cost Index (PCCI) had a lower variation coefficient than the Physiological Cost Index (PCI; 8.5%, 95% confidence interval (CI) 5.8-11.2 vs 24.2%, 95% CI 16.0-32.4) and lower effect size than the Total Heart Beat Index (THBI; 0.16 vs 0.26). The PCCI also had the best responsiveness results on all statistical tests. The PCCI correlation was the largest (r=0.63, P0.01, 95% CI 0.43-0.83, followed by PCI (r=0.53, P0.01, 95% CI 0.34-0.72) and then the THBI (r=0.50, P0.01, 95% CI 0.29-0.71).All three indexes were reproducible and responsive. However, the PCCI gave better statistical results. This index may be useful in functional diagnosis and follow-up of rehabilitation.

To examine the relationship between hand rim propulsion power and energy expenditure (EE) during wheelchair wheeling and to investigate whether adding other variables to the model could improve on the prediction of EE.Individuals who use manual wheelchairs (n=14) performed five different wheeling activities in a wheelchair with a PowerTap power meter hub built into the right rear wheel. Activities included wheeling on a smooth, level surface at three different speeds (4.5, 5.5 and 6.5 km/h), wheeling on a rubberised track at one speed (5.5 km/h) and wheeling on a sidewalk course that included uphill and downhill segments at a self-selected speed. EE was measured using a portable indirect calorimetry system. Stepwise linear regression was performed to predict EE from power output variables. A repeated-measures analysis of variance was used to compare the measured EE to the estimates from the power models. Bland-Altman plots were used to assess the agreement between the criterion values and the predicted values.EE and power were significantly correlated (r=0.694, p0.001). Regression analysis yielded three significant prediction models utilising measured power; measured power and speed; and measured power, speed and heart rate. No significant differences were found between measured EE and any of the prediction models.EE can be accurately and precisely estimated based on hand rim propulsion power. These results indicate that power could be used as a method to assess EE in individuals who use wheelchairs.

AC-DC conversion with power factor correction using full-bridge single-stage (FBSS) converters may introduce various complex operating limits and control problems that are not usually described in literature. This is mainly due to the fact that they devaluate and restrict the number of applications of those topologies. These problems are identified as primary transformer saturation and output voltage perturbations. The operation at light loads and with wide load variation is also a complex issue that leads to uncontrollable input current and dc bus voltage. This paper clarifies such technical problems referring their impact in the FBSS topologies operation, and presents design criteria and control solutions to minimize their effects. A low cost free wheeling circuit (FWC) that allows null input current to solve the light load operation problem is also presented.

The objective of this work was to evaluate the effect of tractor wheeling with a light tractor on the root growth and soil properties of smooth brome in South Estonia. Field experiment was conducted on sandy loam Haplic Luvisol in 2007. Data were collected during September 2008 in both an uncompacted and compacted area. Because of the compaction, the precompression stress increased in the upper soil layer (0−10 cm) by 12.6% and 15.2% at a depth of 10−20 cm. Compaction had only a minor effect on the bulk density, values increased 4.7% in the upper soil layer and 1.8% in the deeper layer. Differences in the saturated hydraulic conductivity (k s ) were not significant; however, the decrease in the k s was 26.6% in the upper level and 12.5% in the deeper (10−20 cm) layer. At a depth of 0 to 30 cm compaction decreased the root length by 44.7% and the root mass by 60.5% compared with the uncompacted soil. Altogether, this study confirms the unfavourable effect of wheeling on grasslands even when the wheeling is performed with a light tractor on dry soil.

Transmission pricing is an important issue for transmission cost allocation. Because of the importance of this issue in the restructured power systems, several methods have been presented in recent years. Also, fairness of methods is a vital issue from the viewpoint of market designers and policy makers. This paper proposes a novel fair method to specify transmission tariffs, especially for wheeling contracts during peak and off-peak periods. In comparison to other recent studies, this approach has the advantage of considering congestion and security cost, when the wheeling contract leads to deviation from the optimum operation of wheeler network. Moreover, the security cost which is usually ignored in the transmission pricing will be allocated to market participants fairly. This method is applicable to implement in combined pool and bilateral electricity markets. In order to make a fair competition among market users, the congestion cost is allocated to all users in proportion to their contribution in network congestion. Compared with the current methods, the proposed approach take into consideration the congestion and security cost to strike the right balance between profit and cost related with fair market-based mechanisms. At the end, numerical examples on nine-bus test power system are utilized to demonstrate the effectiveness of the proposed approach.

With power system restructuring going on the world over, there are increased power transactions due to wheeling, unscheduled flows, higher contractual needs etc. This results in heavy flows in transmission lines causing higher losses with possibility of loss of stability and security. This results in congestion on transmission lines. FACTS device can provide a solution to mitigate the effect of congestion in heavily loaded lines. This paper investigates the effect of SVC, TCSC and UPFC devices on power flows and bus voltages with increased line loadings. The effectiveness of these FACTS devices are demonstrated on two test systems viz. IEEE-14 bus system and WSCC 9 bus system.

In Mexico most of the electrical power systems in the petrochemical industry accommodate generating units. The power systems of these industrial plants were initially designed to operate isolated from the utility grid and the amount of the generation capacity used to be twice the value of the maximum expected demand. Due to changes in the Mexican legislation allowing the use the transmission grid for wheeling the surplus of power generated to another industrial facility of the same owner many of these isolated power systems are being interconnected with the utility grid. As a result of this, the operators of those industrial systems are facing some problems never experienced before. The purpose of this paper is to assess the dynamical behavior of an industrial power system with co-generation units following to the loss of a portion of on-site generation and the sudden loss of the interconnection with the utility grid.

Previous research has reported that training and experience influence H-reflex amplitude during rhythmic activity; however, little research has yet examined the influence of training on cutaneous reflexes. Manual wheelchair users (MWUs) depend on their arms for locomotion. We postulated that the daily dependence and high amount of use of the arms for mobility in MWUs would show differences in cutaneous reflex modulation during upper limb cyclic movements compared with able-bodied control subjects. We hypothesized that MWUs would demonstrate increased reflex response amplitudes for both manual wheeling and symmetrical arm cycling tasks. The superficial radial nerve was stimulated randomly at different points of the movement cycle of manual wheeling and symmetrical arm cycling in MWUs and able-bodied subjects naive to wheeling. Our results showed that there were no differences in amplitude modulation of early- or middle-latency cutaneous reflexes between the able-bodied group and the MWU group. However, there were several differences in amplitude modulation of cutaneous reflexes between tasks (manual wheeling and symmetrical arm cycling). Specifically, differences were observed in early-latency responses in the anterior and posterior deltoid muscles and biceps and triceps brachii as well as in middle-latency responses in the anterior and posterior deltoid. These data suggest that manual wheeling experience does not modify the pattern of cutaneous reflex amplitude modulation during manual wheeling. The differences in amplitude modulation of cutaneous reflexes between tasks may be a result of mechanical differences (i.e., hand contact) between tasks.

For robots, a flexible approach is very important. Even when the robot is a humanoid, it does not have to perfectly mimic human motion. If necessary, the humanoid robot can adapt to other technologies even when these technologies make it different from humans. In a real environment or a disaster environment, humanoid robots are a good solution to assist humans. However, the stability problem of biped locomotion remains. In this paper, we introduce a new strategy of attaching a wheel to our humanoid robot in order to achieve mobility efficiency with a bipedal walking and wheel driven mode. Additionally, this strategy can enhance the stability. Through the proposed method, the humanoid robot can traverse uneven terrain and climb stairs with a walking motion, and can move safely with wheels on the ground. In addition, a method will be presented that can enhance the performance of wheel movement by using redundant joints and sensors on the humanoid robot. Various experiments and the DARPA Robotics Challenge results validate the efficiency and the feasibility of the proposed strategy.

The idea of smart community which is expected to achieve effective utilization of energy at customer side, and contribute to stable operation of power system, for example peak shaving, et. is introduced recently. Since the smart community would optimize the local operation of the community that might affect the stable operation of distribution power system and whole power system, the development of cooperative operation method between community and power system is important. In order to develop the operation method of the community considering cooperation with power system, development of smart community model that is economically feasible is necessary. This report develops the economical evaluation model of smart community for arbitrary condition such as electricity price, purchasing price of generated power of PV, wheeling charge, et. and evaluate the economic efficiency of smart community. According to the evaluation results, a community operator can get benefit by operating community under the condition such as the lower penetration rate of PV, and higher rate of residential area that includes low voltage customers, in which the community operator can sell much electricity with expensive price to low voltage customers. By introducing co-generation system and utilizing exhaust heat for industrial area, the economic efficiency would increase and the community operator can get benefit from dealing with electricity transaction and selling exhaust heat to industrial customer. This paper also considers the Business Continuity Plan (BCP) and evaluates the maximum storage capacity under the condition that the community operator can get benefit, where the battery would be used for back-up power supply when the disaster occurred.

Due to world wide restructuring of electric supply industry, assessment and allocation of wheeling prices among transmission users has become a crucial task. Wheeling prices are supposed to be distributed over transmission users. Allocation of wheeling prices means determination of distribution of wheeling prices among transmission users and this depends upon the contribution of each user in total transmission investment cost. The contribution of transmission user in total transmission cost is decided either by transmission owner or by Regulatory body. In real world scenario, the contribution of producers and customers in cost, may be variable because it depends upon the demand supply relation. This paper presents a new approach of wheeling price allocation among transmission users by applying different level of contribution of each transmission user in total transmission investment. This enables the allocation of wheeling prices for any amount of contribution of generator and load in transmission investment. The proposed approach has been illustrated on Garver's 6-bus test system and IEEE RTS 24-bus system. This has been observed that the perspective presented in this paper is capable of recovering fixed transmission cost for varying amount of contribution of transmission users.

Worldwide most of the energy is provided through conventional energy sources such as thermal, hydro, and nuclear. Industries suffer from serious energy crisis nearly decade; therefore, it is essential to integrate them with other renewable energy resources. This paper presents a cost effective solution, Wheeling 36 MW Grid-connected Hybrid Energy System for Gadoon industrial load in Pakistan. The system has been implemented in HOMER (Hybrid Optimization Model for Electric Renewables) considering five cases for analysis, in which Grid-Hydro-PV-Wind based system, Grid-Hydro based system and Grid based system are discussed, in detail. Since hydro power is already installed, it reduces 26.89% cost of energy and grid purchase to 63.32%. Moreover, the Grid-Hydro-PV-Wind based system is the most economical of all owing to 42.85% reduction in electrical tariff and it also reduces the grid energy consumption to 33.98% as compared to existing Grid based system. The proposed system yields 66% high renewable fraction. We also hope that the nation's dependence on fossil fuels and its economic impact will be made lower. Thus, we expect its contribution towards the progress and growth of industrial sector in Pakistan.