Optimized efficiency of all-electric ships by dc hybrid power systems
NASA Astrophysics Data System (ADS)
Zahedi, Bijan; Norum, Lars E.; Ludvigsen, Kristine B.
2014-06-01
Hybrid power systems with dc distribution are being considered for commercial marine vessels to comply with new stringent environmental regulations, and to achieve higher fuel economy. In this paper, detailed efficiency analysis of a shipboard dc hybrid power system is carried out. An optimization algorithm is proposed to minimize fuel consumption under various loading conditions. The studied system includes diesel engines, synchronous generator-rectifier units, a full-bridge bidirectional converter, and a Li-Ion battery bank as energy storage. In order to evaluate potential fuel saving provided by such a system, an online optimization strategy for fuel consumption is implemented. An Offshore Support Vessel (OSV) is simulated over different operating modes using the online control strategy. The resulted consumed fuel in the simulation is compared to that of a conventional ac power system, and also a dc power system without energy storage. The results show that while the dc system without energy storage provides noticeable fuel saving compared to the conventional ac system, optimal utilization of the energy storage in the dc system results in twice as much fuel saving.
Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System.
Lee, Chengming; Chen, Rongshun
2015-05-20
Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.
Flapping wing flight can save aerodynamic power compared to steady flight.
Pesavento, Umberto; Wang, Z Jane
2009-09-11
Flapping flight is more maneuverable than steady flight. It is debated whether this advantage is necessarily accompanied by a trade-off in the flight efficiency. Here we ask if any flapping motion exists that is aerodynamically more efficient than the optimal steady motion. We solve the Navier-Stokes equation governing the fluid dynamics around a 2D flapping wing, and determine the minimal aerodynamic power needed to support a specified weight. While most flapping wing motions are more costly than the optimal steady wing motion, we find that optimized flapping wing motions can save up to 27% of the aerodynamic power required by the optimal steady flight. We explain the cause of this energetic advantage.
NASA Astrophysics Data System (ADS)
Zulai, Luis G. T.; Durand, Fábio R.; Abrão, Taufik
2015-05-01
In this article, an energy-efficiency mechanism for next-generation passive optical networks is investigated through heuristic particle swarm optimization. Ten-gigabit Ethernet-wavelength division multiplexing optical code division multiplexing-passive optical network next-generation passive optical networks are based on the use of a legacy 10-gigabit Ethernet-passive optical network with the advantage of using only an en/decoder pair of optical code division multiplexing technology, thus eliminating the en/decoder at each optical network unit. The proposed joint mechanism is based on the sleep-mode power-saving scheme for a 10-gigabit Ethernet-passive optical network, combined with a power control procedure aiming to adjust the transmitted power of the active optical network units while maximizing the overall energy-efficiency network. The particle swarm optimization based power control algorithm establishes the optimal transmitted power in each optical network unit according to the network pre-defined quality of service requirements. The objective is controlling the power consumption of the optical network unit according to the traffic demand by adjusting its transmitter power in an attempt to maximize the number of transmitted bits with minimum energy consumption, achieving maximal system energy efficiency. Numerical results have revealed that it is possible to save 75% of energy consumption with the proposed particle swarm optimization based sleep-mode energy-efficiency mechanism compared to 55% energy savings when just a sleeping-mode-based mechanism is deployed.
Study on key technologies of optimization of big data for thermal power plant performance
NASA Astrophysics Data System (ADS)
Mao, Mingyang; Xiao, Hong
2018-06-01
Thermal power generation accounts for 70% of China's power generation, the pollutants accounted for 40% of the same kind of emissions, thermal power efficiency optimization needs to monitor and understand the whole process of coal combustion and pollutant migration, power system performance data show explosive growth trend, The purpose is to study the integration of numerical simulation of big data technology, the development of thermal power plant efficiency data optimization platform and nitrogen oxide emission reduction system for the thermal power plant to improve efficiency, energy saving and emission reduction to provide reliable technical support. The method is big data technology represented by "multi-source heterogeneous data integration", "large data distributed storage" and "high-performance real-time and off-line computing", can greatly enhance the energy consumption capacity of thermal power plants and the level of intelligent decision-making, and then use the data mining algorithm to establish the boiler combustion mathematical model, mining power plant boiler efficiency data, combined with numerical simulation technology to find the boiler combustion and pollutant generation rules and combustion parameters of boiler combustion and pollutant generation Influence. The result is to optimize the boiler combustion parameters, which can achieve energy saving.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ding, Fei; Nagarajan, Adarsh; Baggu, Murali
This paper evaluated the impact of smart inverter Volt-VAR function on voltage reduction energy saving and power quality in electric power distribution systems. A methodology to implement the voltage reduction optimization was developed by controlling the substation LTC and capacitor banks, and having smart inverters participate through their autonomous Volt-VAR control. In addition, a power quality scoring methodology was proposed and utilized to quantify the effect on power distribution system power quality. All of these methodologies were applied to a utility distribution system model to evaluate the voltage reduction energy saving and power quality under various PV penetrations and smartmore » inverter densities.« less
Chassin, David P.; Behboodi, Sahand; Djilali, Ned
2018-01-28
This article proposes a system-wide optimal resource dispatch strategy that enables a shift from a primarily energy cost-based approach, to a strategy using simultaneous price signals for energy, power and ramping behavior. A formal method to compute the optimal sub-hourly power trajectory is derived for a system when the price of energy and ramping are both significant. Optimal control functions are obtained in both time and frequency domains, and a discrete-time solution suitable for periodic feedback control systems is presented. The method is applied to North America Western Interconnection for the planning year 2024, and it is shown that anmore » optimal dispatch strategy that simultaneously considers both the cost of energy and the cost of ramping leads to significant cost savings in systems with high levels of renewable generation: the savings exceed 25% of the total system operating cost for a 50% renewables scenario.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chassin, David P.; Behboodi, Sahand; Djilali, Ned
This article proposes a system-wide optimal resource dispatch strategy that enables a shift from a primarily energy cost-based approach, to a strategy using simultaneous price signals for energy, power and ramping behavior. A formal method to compute the optimal sub-hourly power trajectory is derived for a system when the price of energy and ramping are both significant. Optimal control functions are obtained in both time and frequency domains, and a discrete-time solution suitable for periodic feedback control systems is presented. The method is applied to North America Western Interconnection for the planning year 2024, and it is shown that anmore » optimal dispatch strategy that simultaneously considers both the cost of energy and the cost of ramping leads to significant cost savings in systems with high levels of renewable generation: the savings exceed 25% of the total system operating cost for a 50% renewables scenario.« less
NASA Technical Reports Server (NTRS)
Soloway, Donald I.; Alberts, Thomas E.
1989-01-01
It is often proposed that the redundancy in choosing a force distribution for multiple arms grasping a single object should be handled by minimizing a quadratic performance index. The performance index may be formulated in terms of joint torques or in terms of the Cartesian space force/torque applied to the body by the grippers. The former seeks to minimize power consumption while the latter minimizes body stresses. Because the cost functions are related to each other by a joint angle dependent transformation on the weight matrix, it might be argued that either method tends to reduce power consumption, but clearly the joint space minimization is optimal. A comparison of these two options is presented with consideration given to computational cost and power consumption. Simulation results using a two arm robot system are presented to show the savings realized by employing the joint space optimization. These savings are offset by additional complexity, computation time and in some cases processor power consumption.
Cui, Borui; Gao, Dian-ce; Xiao, Fu; ...
2016-12-23
This article provides a method in comprehensive evaluation of cost-saving potential of active cool thermal energy storage (CTES) integrated with HVAC system for demand management in non-residential building. The active storage is beneficial by shifting peak demand for peak load management (PLM) as well as providing longer duration and larger capacity of demand response (DR). In this research, a model-based optimal design method using genetic algorithm is developed to optimize the capacity of active CTES aiming for maximizing the life-cycle cost saving concerning capital cost associated with storage capacity as well as incentives from both fast DR and PLM. Inmore » the method, the active CTES operates under a fast DR control strategy during DR events while under the storage-priority operation mode to shift peak demand during normal days. The optimal storage capacities, maximum annual net cost saving and corresponding power reduction set-points during DR event are obtained by using the proposed optimal design method. Lastly, this research provides guidance in comprehensive evaluation of cost-saving potential of CTES integrated with HVAC system for building demand management including both fast DR and PLM.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cui, Borui; Gao, Dian-ce; Xiao, Fu
This article provides a method in comprehensive evaluation of cost-saving potential of active cool thermal energy storage (CTES) integrated with HVAC system for demand management in non-residential building. The active storage is beneficial by shifting peak demand for peak load management (PLM) as well as providing longer duration and larger capacity of demand response (DR). In this research, a model-based optimal design method using genetic algorithm is developed to optimize the capacity of active CTES aiming for maximizing the life-cycle cost saving concerning capital cost associated with storage capacity as well as incentives from both fast DR and PLM. Inmore » the method, the active CTES operates under a fast DR control strategy during DR events while under the storage-priority operation mode to shift peak demand during normal days. The optimal storage capacities, maximum annual net cost saving and corresponding power reduction set-points during DR event are obtained by using the proposed optimal design method. Lastly, this research provides guidance in comprehensive evaluation of cost-saving potential of CTES integrated with HVAC system for building demand management including both fast DR and PLM.« less
Analysis of Optimal Jitter Buffer Size for VoIP QoS under WiMAX Power-Saving Mode
NASA Astrophysics Data System (ADS)
Kim, Hyungsuk; Kim, Taehyoun
VoIP service is expected as one of the key applications of Mobile WiMAX, but the speech quality of VoIP service often suffers deterioration due to the fluctuating transmission delay called jitter. This is commonly ameliorated by a de-jitter buffer, and we aim to find the optimal size of de-jitter buffer to achieve speech quality comparable to PSTN. We developed a new model of the packet drops at the de-jitter buffer and the end-to-end packet delay which takes account of the additional delay introduced by the WiMAX power-saving mode. Using our model, we analyzed the optimal size of the de-jitter buffer for various network parameters, and showed that the results obtained by analysis accord with simulation results.
Shi, Xiao-Qing; Li, Xiao-Nuo; Yang, Jian-Xin
2013-01-01
Transportation is the key industry of urban energy consumption and carbon emissions. The transformation of conventional gasoline vehicles to new energy vehicles is an important initiative to realize the goal of developing low-carbon city through energy saving and emissions reduction, while electric vehicles (EV) will play an important role in this transition due to their advantage in energy saving and lower carbon emissions. After reviewing the existing researches on energy saving and emissions reduction of electric vehicles, this paper analyzed the factors affecting carbon emissions reduction. Combining with electric vehicles promotion program in Beijing, the paper analyzed carbon emissions and reduction potential of electric vehicles in six scenarios using the optimized energy consumption related carbon emissions model from the perspective of fuel life cycle. The scenarios included power energy structure, fuel type (energy consumption per 100 km), car type (CO2 emission factor of fuel), urban traffic conditions (speed), coal-power technologies and battery type (weight, energy efficiency). The results showed that the optimized model was able to estimate carbon emissions caused by fuel consumption more reasonably; electric vehicles had an obvious restrictive carbon reduction potential with the fluctuation of 57%-81.2% in the analysis of six influencing factors, while power energy structure and coal-power technologies play decisive roles in life-cycle carbon emissions of electric vehicles with the reduction potential of 78.1% and 81.2%, respectively. Finally, some optimized measures were proposed to reduce transport energy consumption and carbon emissions during electric vehicles promotion including improving energy structure and coal technology, popularizing energy saving technologies and electric vehicles, accelerating the battery R&D and so on. The research provides scientific basis and methods for the policy development for the transition of new energy vehicles in low-carbon transport.
DEMONSTRATION AND TESTING OF AN EER OPTIMIZER SYSTEM FOR DX AIR-CONDITIONERS
2017-10-07
Performance-Based Maintenance PCS Power Current Sensor PLC Programmable Logic Controller ppm Parts Per Million PSIG Pounds per Square Inch Gauge PVS Power...all utilities and facilities at Patrick AFB, Cape Canaveral AFS, Jonathan Dickinson Military Tracking Annex, Malabar Annex, Ramey Solar Observatory...Cost 8,057 0 Annual O&M Cost 453 1191 Annual FD&D Monitoring 880 ‐ BLCC LIFE CYCLE RESULTS Energy Savings $12,317 O&M Net Savings $493 PV Life Cycle
NASA Astrophysics Data System (ADS)
Gopalakrishnan, T.; Saravanan, R.
2017-03-01
Powerful management concepts step-up the quality of the product, time saving in producing the product thereby increase the production rate, improves tools and techniques, work culture, work place and employee motivation and morale. In this paper discussed about the case study of optimizing the tool design, tool parameters to cast off expansion plan according ECRS technique. The proposed designs and optimal tool parameters yielded best results and meet the customer demand without expansion plan. Hence the work yielded huge savings of money (direct and indirect cost), time and improved the motivation and more of employees significantly.
A location selection policy of live virtual machine migration for power saving and load balancing.
Zhao, Jia; Ding, Yan; Xu, Gaochao; Hu, Liang; Dong, Yushuang; Fu, Xiaodong
2013-01-01
Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful.
A Location Selection Policy of Live Virtual Machine Migration for Power Saving and Load Balancing
Xu, Gaochao; Hu, Liang; Dong, Yushuang; Fu, Xiaodong
2013-01-01
Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful. PMID:24348165
A Novel Artificial Bee Colony Approach of Live Virtual Machine Migration Policy Using Bayes Theorem
Xu, Gaochao; Hu, Liang; Fu, Xiaodong
2013-01-01
Green cloud data center has become a research hotspot of virtualized cloud computing architecture. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on the VM placement selection of live migration for power saving. We present a novel heuristic approach which is called PS-ABC. Its algorithm includes two parts. One is that it combines the artificial bee colony (ABC) idea with the uniform random initialization idea, the binary search idea, and Boltzmann selection policy to achieve an improved ABC-based approach with better global exploration's ability and local exploitation's ability. The other one is that it uses the Bayes theorem to further optimize the improved ABC-based process to faster get the final optimal solution. As a result, the whole approach achieves a longer-term efficient optimization for power saving. The experimental results demonstrate that PS-ABC evidently reduces the total incremental power consumption and better protects the performance of VM running and migrating compared with the existing research. It makes the result of live VM migration more high-effective and meaningful. PMID:24385877
A novel artificial bee colony approach of live virtual machine migration policy using Bayes theorem.
Xu, Gaochao; Ding, Yan; Zhao, Jia; Hu, Liang; Fu, Xiaodong
2013-01-01
Green cloud data center has become a research hotspot of virtualized cloud computing architecture. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on the VM placement selection of live migration for power saving. We present a novel heuristic approach which is called PS-ABC. Its algorithm includes two parts. One is that it combines the artificial bee colony (ABC) idea with the uniform random initialization idea, the binary search idea, and Boltzmann selection policy to achieve an improved ABC-based approach with better global exploration's ability and local exploitation's ability. The other one is that it uses the Bayes theorem to further optimize the improved ABC-based process to faster get the final optimal solution. As a result, the whole approach achieves a longer-term efficient optimization for power saving. The experimental results demonstrate that PS-ABC evidently reduces the total incremental power consumption and better protects the performance of VM running and migrating compared with the existing research. It makes the result of live VM migration more high-effective and meaningful.
Optimization of the Flapping Wing Systems for Micro Air Vehicle
2010-09-01
as 87%, under specific combinations of the flapping kinematics by water tunnel experiments [5]. Pesavento and Wang found that optimized flapping wing...41-72. [6] Pesavento , U., and Wang Z. J., “Flapping Wing Flight Can Save Aerodynamic Power Compared to Steady Flight,” Physical Review Letters
NASA Astrophysics Data System (ADS)
Wang, Qingze; Chen, Xingying; Ji, Li; Liao, Yingchen; Yu, Kun
2017-05-01
The air-conditioning system of office building is a large power consumption terminal equipment, whose unreasonable operation mode leads to low energy efficiency. Realizing the optimization of the air-conditioning system has become one of the important research contents of the electric power demand response. In this paper, in order to save electricity cost and improve energy efficiency, bi-level optimization method of air-conditioning system based on TOU price is put forward by using the energy storage characteristics of the office building itself. In the upper level, the operation mode of the air-conditioning system is optimized in order to minimize the uses’ electricity cost in the premise of ensuring user’ comfort according to the information of outdoor temperature and TOU price, and the cooling load of the air-conditioning is output to the lower level; In the lower level, the distribution mode of cooling load among the multi chillers is optimized in order to maximize the energy efficiency according to the characteristics of each chiller. Finally, the experimental results under different modes demonstrate that the strategy can improve the energy efficiency of chillers and save the electricity cost for users.
User's manual for the BNW-I optimization code for dry-cooled power plants. Volume I
DOE Office of Scientific and Technical Information (OSTI.GOV)
Braun, D.J.; Daniel, D.J.; De Mier, W.V.
1977-01-01
This User's Manual provides information on the use and operation of three versions of BNW-I, a computer code developed by Battelle, Pacific Northwest Laboratory (PNL) as a part of its activities under the ERDA Dry Cooling Tower Program. These three versions of BNW-I were used as reported elsewhere to obtain comparative incremental costs of electrical power production by two advanced concepts (one using plastic heat exchangers and one using ammonia as an intermediate heat transfer fluid) and a state-of-the-art system. The computer program offers a comprehensive method of evaluating the cost savings potential of dry-cooled heat rejection systems and componentsmore » for power plants. This method goes beyond simple ''figure-of-merit'' optimization of the cooling tower and includes such items as the cost of replacement capacity needed on an annual basis and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence, the BNW-I code is a useful tool for determining potential cost savings of new heat transfer surfaces, new piping or other components as part of an optimized system for a dry-cooled power plant.« less
Analysis on energy consumption index system of thermal power plant
NASA Astrophysics Data System (ADS)
Qian, J. B.; Zhang, N.; Li, H. F.
2017-05-01
Currently, the increasingly tense situation in the context of resources, energy conservation is a realistic choice to ease the energy constraint contradictions, reduce energy consumption thermal power plants has become an inevitable development direction. And combined with computer network technology to build thermal power “small index” to monitor and optimize the management system, the power plant is the application of information technology and to meet the power requirements of the product market competition. This paper, first described the research status of thermal power saving theory, then attempted to establish the small index system and build “small index” monitoring and optimization management system in thermal power plant. Finally elaborated key issues in the field of small thermal power plant technical and economic indicators to be further studied and resolved.
System-level power optimization for real-time distributed embedded systems
NASA Astrophysics Data System (ADS)
Luo, Jiong
Power optimization is one of the crucial design considerations for modern electronic systems. In this thesis, we present several system-level power optimization techniques for real-time distributed embedded systems, based on dynamic voltage scaling, dynamic power management, and management of peak power and variance of the power profile. Dynamic voltage scaling has been widely acknowledged as an important and powerful technique to trade off dynamic power consumption and delay. Efficient dynamic voltage scaling requires effective variable-voltage scheduling mechanisms that can adjust voltages and clock frequencies adaptively based on workloads and timing constraints. For this purpose, we propose static variable-voltage scheduling algorithms utilizing criticalpath driven timing analysis for the case when tasks are assumed to have uniform switching activities, as well as energy-gradient driven slack allocation for a more general scenario. The proposed techniques can achieve closeto-optimal power savings with very low computational complexity, without violating any real-time constraints. We also present algorithms for power-efficient joint scheduling of multi-rate periodic task graphs along with soft aperiodic tasks. The power issue is addressed through both dynamic voltage scaling and power management. Periodic task graphs are scheduled statically. Flexibility is introduced into the static schedule to allow the on-line scheduler to make local changes to PE schedules through resource reclaiming and slack stealing, without interfering with the validity of the global schedule. We provide a unified framework in which the response times of aperiodic tasks and power consumption are dynamically optimized simultaneously. Interconnection network fabrics point to a new generation of power-efficient and scalable interconnection architectures for distributed embedded systems. As the system bandwidth continues to increase, interconnection networks become power/energy limited as well. Variable-frequency links have been designed by circuit designers for both parallel and serial links, which can adaptively regulate the supply voltage of transceivers to a desired link frequency, to exploit the variations in bandwidth requirement for power savings. We propose solutions for simultaneous dynamic voltage scaling of processors and links. The proposed solution considers real-time scheduling, flow control, and packet routing jointly. It can trade off the power consumption on processors and communication links via efficient slack allocation, and lead to more power savings than dynamic voltage scaling on processors alone. For battery-operated systems, the battery lifespan is an important concern. Due to the effects of discharge rate and battery recovery, the discharge pattern of batteries has an impact on the battery lifespan. Battery models indicate that even under the same average power consumption, reducing peak power current and variance in the power profile can increase the battery efficiency and thereby prolong battery lifetime. To take advantage of these effects, we propose battery-driven scheduling techniques for embedded applications, to reduce the peak power and the variance in the power profile of the overall system under real-time constraints. The proposed scheduling algorithms are also beneficial in addressing reliability and signal integrity concerns by effectively controlling peak power and variance of the power profile.
NASA Astrophysics Data System (ADS)
Lesmana, E.; Chaerani, D.; Khansa, H. N.
2018-03-01
Energy-Saving Generation Dispatch (ESGD) is a scheme made by Chinese Government in attempt to minimize CO2 emission produced by power plant. This scheme is made related to global warming which is primarily caused by too much CO2 in earth’s atmosphere, and while the need of electricity is something absolute, the power plants producing it are mostly thermal-power plant which produced many CO2. Many approach to fulfill this scheme has been made, one of them came through Minimum Cost Flow in which resulted in a Quadratically Constrained Quadratic Programming (QCQP) form. In this paper, ESGD problem with Minimum Cost Flow in QCQP form will be solved using Lagrange’s Multiplier Method
1993-09-01
Different Size Transformers (Per Transformer ) 41 15 Additional Energy Losses for Mis-Sized Transformers (Per Transformer ) 42 16 Power System ...directly affects the amount of neutral line power loss in the system . Since most Army three-phase loads are distribution transformers spread out over a...61 Balancing Three-Phase Loads Balancing Feeder Circuit Loads Power Factor Correction Optimal Transformer Sizing Conductor Sizing Combined
CO2 Mitigation Measures of Power Sector and Its Integrated Optimization in China
Dai, Pan; Chen, Guang; Zhou, Hao; Su, Meirong; Bao, Haixia
2012-01-01
Power sector is responsible for about 40% of the total CO2 emissions in the world and plays a leading role in climate change mitigation. In this study, measures that lower CO2 emissions from the supply side, demand side, and power grid are discussed, based on which, an integrated optimization model of CO2 mitigation (IOCM) is proposed. Virtual energy, referring to energy saving capacity in both demand side and the power grid, together with conventional energy in supply side, is unified planning for IOCM. Consequently, the optimal plan of energy distribution, considering both economic benefits and mitigation benefits, is figured out through the application of IOCM. The results indicate that development of demand side management (DSM) and smart grid can make great contributions to CO2 mitigation of power sector in China by reducing the CO2 emissions by 10.02% and 12.59%, respectively, in 2015, and in 2020. PMID:23213305
Study on and the implementation of solar powered street lighting in SEEE, USM
NASA Astrophysics Data System (ADS)
Arshad, M. S.; Ain, M. F.; Ishak, D.; Rahman, A. L. A.; Nazri, A. S.; Abdullah, M. N.; Kaharuddin, S.; Hussin, R.
2017-10-01
Solar Powered Street Lights is a project that can be served to School of Electrical & Electronic Engineering (SEEE), Universiti Sains Malaysia in electricity cost savings by implementing the existing solar Photovoltaic (PV) system used for a green technology of energy efficiency. Due to the electricity of the national grid Tenaga Nasional Berhad (TNB) continue to increases, perhaps this system is able to maximize cost savings for SEEE. Solar energy collected during the day will be converted into electricity to charge the battery. Electricity charged the battery then will be connected and used to power the lights around the SEEE parking area at night. After taking all important aspects into accounts that help to optimize energy saving, this system has been proven to reduce electricity costs. System data such as the power consumption of the load, battery charging rates, and other relevant data is measured. From the measured data, calculations and analysis were performed to determine the actual performance of the system. Proper wiring connections between solar PV systems and light poles grid around the SEEE parking lot have been executed. As a result, the implementation of this system could save as much as RM 462.86 for the cost of monthly electricity bills incurred by the SEEE.
Optimizing Wellfield Operation in a Variable Power Price Regime.
Bauer-Gottwein, Peter; Schneider, Raphael; Davidsen, Claus
2016-01-01
Wellfield management is a multiobjective optimization problem. One important objective has been energy efficiency in terms of minimizing the energy footprint (EFP) of delivered water (MWh/m(3) ). However, power systems in most countries are moving in the direction of deregulated markets and price variability is increasing in many markets because of increased penetration of intermittent renewable power sources. In this context the relevant management objective becomes minimizing the cost of electric energy used for pumping and distribution of groundwater from wells rather than minimizing energy use itself. We estimated EFP of pumped water as a function of wellfield pumping rate (EFP-Q relationship) for a wellfield in Denmark using a coupled well and pipe network model. This EFP-Q relationship was subsequently used in a Stochastic Dynamic Programming (SDP) framework to minimize total cost of operating the combined wellfield-storage-demand system over the course of a 2-year planning period based on a time series of observed price on the Danish power market and a deterministic, time-varying hourly water demand. In the SDP setup, hourly pumping rates are the decision variables. Constraints include storage capacity and hourly water demand fulfilment. The SDP was solved for a baseline situation and for five scenario runs representing different EFP-Q relationships and different maximum wellfield pumping rates. Savings were quantified as differences in total cost between the scenario and a constant-rate pumping benchmark. Minor savings up to 10% were found in the baseline scenario, while the scenario with constant EFP and unlimited pumping rate resulted in savings up to 40%. Key factors determining potential cost savings obtained by flexible wellfield operation under a variable power price regime are the shape of the EFP-Q relationship, the maximum feasible pumping rate and the capacity of available storage facilities. © 2015 The Authors. Groundwater published by Wiley Periodicals, Inc. on behalf of National Ground Water Association.
Scheduling for energy and reliability management on multiprocessor real-time systems
NASA Astrophysics Data System (ADS)
Qi, Xuan
Scheduling algorithms for multiprocessor real-time systems have been studied for years with many well-recognized algorithms proposed. However, it is still an evolving research area and many problems remain open due to their intrinsic complexities. With the emergence of multicore processors, it is necessary to re-investigate the scheduling problems and design/develop efficient algorithms for better system utilization, low scheduling overhead, high energy efficiency, and better system reliability. Focusing cluster schedulings with optimal global schedulers, we study the utilization bound and scheduling overhead for a class of cluster-optimal schedulers. Then, taking energy/power consumption into consideration, we developed energy-efficient scheduling algorithms for real-time systems, especially for the proliferating embedded systems with limited energy budget. As the commonly deployed energy-saving technique (e.g. dynamic voltage frequency scaling (DVFS)) will significantly affect system reliability, we study schedulers that have intelligent mechanisms to recuperate system reliability to satisfy the quality assurance requirements. Extensive simulation is conducted to evaluate the performance of the proposed algorithms on reduction of scheduling overhead, energy saving, and reliability improvement. The simulation results show that the proposed reliability-aware power management schemes could preserve the system reliability while still achieving substantial energy saving.
NASA Astrophysics Data System (ADS)
Cao, Jia; Yan, Zheng; He, Guangyu
2016-06-01
This paper introduces an efficient algorithm, multi-objective human learning optimization method (MOHLO), to solve AC/DC multi-objective optimal power flow problem (MOPF). Firstly, the model of AC/DC MOPF including wind farms is constructed, where includes three objective functions, operating cost, power loss, and pollutant emission. Combining the non-dominated sorting technique and the crowding distance index, the MOHLO method can be derived, which involves individual learning operator, social learning operator, random exploration learning operator and adaptive strategies. Both the proposed MOHLO method and non-dominated sorting genetic algorithm II (NSGAII) are tested on an improved IEEE 30-bus AC/DC hybrid system. Simulation results show that MOHLO method has excellent search efficiency and the powerful ability of searching optimal. Above all, MOHLO method can obtain more complete pareto front than that by NSGAII method. However, how to choose the optimal solution from pareto front depends mainly on the decision makers who stand from the economic point of view or from the energy saving and emission reduction point of view.
Qi, Xuewei; Wu, Guoyuan; Boriboonsomsin, Kanok; ...
2016-01-01
Plug-in hybrid electric vehicles (PHEVs) show great promise in reducing transportation-related fossil fuel consumption and greenhouse gas emissions. Designing an efficient energy management system (EMS) for PHEVs to achieve better fuel economy has been an active research topic for decades. Most of the advanced systems rely either on a priori knowledge of future driving conditions to achieve the optimal but not real-time solution (e.g., using a dynamic programming strategy) or on only current driving situations to achieve a real-time but nonoptimal solution (e.g., rule-based strategy). This paper proposes a reinforcement learning–based real-time EMS for PHEVs to address the trade-off betweenmore » real-time performance and optimal energy savings. The proposed model can optimize the power-split control in real time while learning the optimal decisions from historical driving cycles. Here, a case study on a real-world commute trip shows that about a 12% fuel saving can be achieved without considering charging opportunities; further, an 8% fuel saving can be achieved when charging opportunities are considered, compared with the standard binary mode control strategy.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qi, Xuewei; Wu, Guoyuan; Boriboonsomsin, Kanok
Plug-in hybrid electric vehicles (PHEVs) show great promise in reducing transportation-related fossil fuel consumption and greenhouse gas emissions. Designing an efficient energy management system (EMS) for PHEVs to achieve better fuel economy has been an active research topic for decades. Most of the advanced systems rely either on a priori knowledge of future driving conditions to achieve the optimal but not real-time solution (e.g., using a dynamic programming strategy) or on only current driving situations to achieve a real-time but nonoptimal solution (e.g., rule-based strategy). This paper proposes a reinforcement learning–based real-time EMS for PHEVs to address the trade-off betweenmore » real-time performance and optimal energy savings. The proposed model can optimize the power-split control in real time while learning the optimal decisions from historical driving cycles. Here, a case study on a real-world commute trip shows that about a 12% fuel saving can be achieved without considering charging opportunities; further, an 8% fuel saving can be achieved when charging opportunities are considered, compared with the standard binary mode control strategy.« less
Improved Planning and Programming for Energy Efficient New Army Facilities
1988-10-01
setpoints to occupant comfort must be considered carefully. Cutting off the HVAC system to the bedrooms during the day produced only small savings...functions of a building and minimizing the energy usage through optimization . It includes thermostats, time switches, programmable con- trollers...microprocessor systems, computers, and sensing devices that are linked with control and power components to manage energy use. This system optimizes load
NASA Astrophysics Data System (ADS)
Wang, Jianhua; Cheng, Lianglun; Wang, Tao; Peng, Xiaodong
2016-03-01
Table look-up operation plays a very important role during the decoding processing of context-based adaptive variable length decoding (CAVLD) in H.264/advanced video coding (AVC). However, frequent table look-up operation can result in big table memory access, and then lead to high table power consumption. Aiming to solve the problem of big table memory access of current methods, and then reduce high power consumption, a memory-efficient table look-up optimized algorithm is presented for CAVLD. The contribution of this paper lies that index search technology is introduced to reduce big memory access for table look-up, and then reduce high table power consumption. Specifically, in our schemes, we use index search technology to reduce memory access by reducing the searching and matching operations for code_word on the basis of taking advantage of the internal relationship among length of zero in code_prefix, value of code_suffix and code_lengh, thus saving the power consumption of table look-up. The experimental results show that our proposed table look-up algorithm based on index search can lower about 60% memory access consumption compared with table look-up by sequential search scheme, and then save much power consumption for CAVLD in H.264/AVC.
Optimization of a heat-pipe-cooled space radiator for use with a reactor-powered Stirling engine
NASA Technical Reports Server (NTRS)
Moriarty, Michael P.; French, Edward P.
1987-01-01
The design optimization of a reactor-Stirling heat-pipe-cooled radiator is presented. The radiator is a self-deploying concept that uses individual finned heat pipe 'petals' to reject waste heat from a Stirling engine. Radiator optimization methodology is presented, and the results of a parametric analysis of the radiator design variables for a 100-kW(e) system are given. The additional steps of optiminzing the radiator resulted in a net system mass savings of 3 percent.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ron Moon
This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically,more » power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. The goal of the 'Recovery Act: Decreasing Data Center Energy Use through Network and Infrastructure Control' is to develop a state of the art approach for autonomously and intelligently reducing and managing data center power through real-time optimal control. Advances in microelectronics and software are enabling the opportunity to realize significant data center power savings through the implementation of autonomous power management control algorithms. The first step to realizing these savings was addressed in this study through the successful creation of a flexible and scalable mathematical model (equation) for data center behavior and the formulation of an acceptable low technical risk market introduction strategy leveraging commercial hardware and software familiar to the data center market. Follow-on Stage 3 Concept Development efforts include predictive modeling and simulation of algorithm performance, prototype demonstrations with representative data center equipment to verify requisite performance and continued commercial partnering agreement formation to ensure uninterrupted development, and deployment of the real-time optimal control algorithm. As a software implementable technique for reducing power consumption, the RTOC has two very desirable traits supporting rapid prototyping and ultimately widespread dissemination. First, very little capital is required for implementation. No major infrastructure modifications are required and there is no need to purchase expensive capital equipment. Second, the RTOC can be rolled out incrementally. Therefore, the effectiveness can be proven without a large scale initial roll out. Through the use of the Impact Projections Model provided by the DOE, monetary savings in excess of $100M in 2020 and billions by 2040 are predicted. In terms of energy savings, the model predicts a primary energy displacement of 260 trillion BTUs (33 trillion kWh), or a 50% reduction in server power consumption. The model also predicts a corresponding reduction of pollutants such as SO2 and NOx in excess of 100,000 metric tonnes assuming the RTOC is fully deployed. While additional development and prototyping is required to validate these predictions, the relative low cost and ease of implementation compared to large capital projects makes it an ideal candidate for further investigation.« less
NASA Astrophysics Data System (ADS)
Liang, Ya-Wei; Zhang, Hong-Mei; Dong, Jin-Zhi; Shi, Zhen-Hua
2016-05-01
Building Integrated Photovoltaic (BIPV) is a resort to save energy and reduce heat gain of buildings, utilize new and renewable energy, solve environment problems and alleviate electricity shortage in large cities. The area needed to generate power makes facade integrated photovoltaic panel a superb choice, especially in high-rise buildings. Numerous scholars have hitherto explored Building Facade Integrated Photovoltaic, however, focusing mainly on thermal performance, which fails to ensure seismic safety of high-rise buildings integrated photovoltaic. Based on connecting forms of the glass curtain wall, a connector jointing photovoltaic panel and facade was designed, which underwent loading position and size optimization. Static loading scenarios were conducted to test and verify the connector's mechanical properties under gravity and wind loading by means of HyperWorks. Compared to the unoptimized design, the optimized one saved material and managed to reduce maximum deflection by 74.64%.
User's manual for the BNW-II optimization code for dry/wet-cooled power plants
DOE Office of Scientific and Technical Information (OSTI.GOV)
Braun, D.J.; Bamberger, J.A.; Braun, D.J.
1978-05-01
The User's Manual describes how to operate BNW-II, a computer code developed by the Pacific Northwest Laboratory (PNL) as a part of its activities under the Department of Energy (DOE) Dry Cooling Enhancement Program. The computer program offers a comprehensive method of evaluating the cost savings potential of dry/wet-cooled heat rejection systems. Going beyond simple ''figure-of-merit'' cooling tower optimization, this method includes such items as the cost of annual replacement capacity, and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence the BNW-II code ismore » a useful tool for determining potential cost savings of new dry/wet surfaces, new piping, or other components as part of an optimized system for a dry/wet-cooled plant.« less
Power management and control for space systems
NASA Technical Reports Server (NTRS)
Finke, R. C.; Myers, I. T.; Terdan, F. F.; Stevens, N. J.
1978-01-01
Power management and control technology for the large, high-power spacecraft of the 1980's is discussed. Systems weight optimization that indicate a need for higher bus voltages are shown. Environmental interactions that are practical limits for the maximum potential on exposed surfaces are shown. A dual-voltage system is proposed that would provide the weight savings of a high-voltage distribution system and take into account the potential environmental interactions. The technology development of new components and circuits is also discussed.
NASA Astrophysics Data System (ADS)
Liu, Yu; Zeng, Ming; Liu, Wei; Li, Ran
2017-05-01
The so-called Large Customers' Direct Power Transaction, refers to the mode that the users on high voltage level, or being seized of hold the large power or independent power distribution, have the qualification of purchasing electricity directly from the generation companies and pay reasonable electricity transmission and distribution fee to the power network enterprises because the transaction is through its transmission channel. The Direct Purchase promotes the marketization level of electricity trading, but there are some problems in its developing process, especially whether promotes the green optimal allocation of power resources, this paper aims to explore the solution.
Optimizing Data Centre Energy and Environmental Costs
NASA Astrophysics Data System (ADS)
Aikema, David Hendrik
Data centres use an estimated 2% of US electrical power which accounts for much of their total cost of ownership. This consumption continues to grow, further straining power grids attempting to integrate more renewable energy. This dissertation focuses on assessing and reducing data centre environmental and financial costs. Emissions of projects undertaken to lower the data centre environmental footprints can be assessed and the emission reduction projects compared using an ISO-14064-2-compliant greenhouse gas reduction protocol outlined herein. I was closely involved with the development of the protocol. Full lifecycle analysis and verifying that projects exceed business-as-usual expectations are addressed, and a test project is described. Consuming power when it is low cost or when renewable energy is available can be used to reduce the financial and environmental costs of computing. Adaptation based on the power price showed 10--50% potential savings in typical cases, and local renewable energy use could be increased by 10--80%. Allowing a fraction of high-priority tasks to proceed unimpeded still allows significant savings. Power grid operators use mechanisms called ancillary services to address variation and system failures, paying organizations to alter power consumption on request. By bidding to offer these services, data centres may be able to lower their energy costs while reducing their environmental impact. If providing contingency reserves which require only infrequent action, savings of up to 12% were seen in simulations. Greater power cost savings are possible for those ceding more control to the power grid operator. Coordinating multiple data centres adds overhead, and altering at which data centre requests are processed based on changes in the financial or environmental costs of power is likely to increase this overhead. Tests of virtual machine migrations showed that in some cases there was no visible increase in power use while in others power use rose by 20--30W. Estimates of how migration was likely to impact other services used in current cloud environments were derived.
A Suboptimal Power-Saving Transmission Scheme in Multiple Component Carrier Networks
NASA Astrophysics Data System (ADS)
Chung, Yao-Liang; Tsai, Zsehong
Power consumption due to transmissions in base stations (BSs) has been a major contributor to communication-related CO2 emissions. A power optimization model is developed in this study with respect to radio resource allocation and activation in a multiple Component Carrier (CC) environment. We formulate and solve the power-minimization problem of the BS transceivers for multiple-CC networks with carrier aggregation, while maintaining the overall system and respective users' utilities above minimum levels. The optimized power consumption based on this model can be viewed as a lower bound of that of other algorithms employed in practice. A suboptimal scheme with low computation complexity is proposed. Numerical results show that the power consumption of our scheme is much better than that of the conventional one in which all CCs are always active, if both schemes maintain the same required utilities.
The State-of-the-Art of Materials Technology Used for Fossil and Nuclear Power Plants in China
NASA Astrophysics Data System (ADS)
Weng, Yuqing
Combined with the development of energy in China during the past 30 years, this paper clarified that high steam parameters ultra-supercritical (USC) coal-fired power plants and 1000MW nuclear power plants are the most important method to optimize energy structure and achieve national goals of energy saving and CO2 emission in China. Additionally, requirement of materials technology in high steam parameters USC coal-fired power plants and 1000MW nuclear power plants, current research and major development of relevant materials technology in China were briefly described in this paper.
Predictions of Energy Savings in HVAC Systems by Lumped Models (Preprint)
2010-04-14
various control devices into a simulated HVAC system. Con- trols contain a setpoint of 26.7oC. The adjustable damper, variable chiller work input, and variable fanspeed contain values of αP of -1.0, 0.1, and 1.0, respectively. 25 ...Villanova, PA 19085 bCode 985, Naval System Warfare Center, Carderock Division, Philadelphia, PA 19112 Abstract An approach to optimizing the energy...suggest an order of mag- nitude greater energy savings using a variable chiller power control approach compared to control damper and variable-drive
Light intensity distribution optimization for tunnel lamps in different zones of a long tunnel.
Lai, Wei; Liu, Xianming; Chen, Weimin; Lei, Xiaohua; Cheng, Xingfu
2014-09-22
The light distributions in different tunnel zones have different requirements in order to meet the driver's visual system. In this paper, the light intensity distributions of tunnel lamps in different zones of a long tunnel are optimized separately. A common nonlinear optimization approach is proposed to minimize the consuming power as well as satisfy the luminance and glare requirements both on the road surface and on the wall set by International Commission on Illumination (CIE). Compared with that of the reported linear optimization method, the optimization model can save energy from 11% to 57.6% under the same installation conditions.
AS Migration and Optimization of the Power Integrated Data Network
NASA Astrophysics Data System (ADS)
Zhou, Junjie; Ke, Yue
2018-03-01
In the transformation process of data integration network, the impact on the business has always been the most important reference factor to measure the quality of network transformation. With the importance of the data network carrying business, we must put forward specific design proposals during the transformation, and conduct a large number of demonstration and practice to ensure that the transformation program meets the requirements of the enterprise data network. This paper mainly demonstrates the scheme of over-migrating point-to-point access equipment in the reconstruction project of power data comprehensive network to migrate the BGP autonomous domain to the specified domain defined in the industrial standard, and to smooth the intranet OSPF protocol Migration into ISIS agreement. Through the optimization design, eventually making electric power data network performance was improved on traffic forwarding, traffic forwarding path optimized, extensibility, get larger, lower risk of potential loop, the network stability was improved, and operational cost savings, etc.
NASA Astrophysics Data System (ADS)
Woldeyesus, Tibebe Argaw
Water supply constraints can significantly restrict electric power generation, and such constraints are expected to worsen with future climate change. The overarching goal of this thesis is to incorporate stochastic water-climate interactions into electricity portfolio models and evaluate various pathways for water savings in co-managed water-electric utilities. Colorado Springs Utilities (CSU) is used as a case study to explore the above issues. The thesis consists of three objectives: Characterize seasonality of water withdrawal intensity factors (WWIF) for electric power generation and develop a risk assessment framework due to water shortages; Incorporate water constraints into electricity portfolio models and evaluate the impact of varying capital investments (both power generation and cooling technologies) on water use and greenhouse gas emissions; Compare the unit cost and overall water savings from both water and electric sectors in co-managed utilities to facilitate overall water management. This thesis provided the first discovery and characterization of seasonality of WWIF with distinct summertime and wintertime variations of +/-17% compared to the power plant average (0.64gal/kwh) which itself is found to be significantly higher than the literature average (0.53gal/kwh). Both the streamflow and WWIF are found to be highly correlated with monthly average temperature (r-sq = 89%) and monthly precipitation (r-sq of 38%) enabling stochastic simulation of future WWIF under moderate climate change scenario. Future risk to electric power generation also showed the risk to be underestimated significantly when using either the literature average or the power plant average WWIF. Seasonal variation in WWIF along with seasonality in streamflow, electricity demand and other municipal water demands along with storage are shown to be important factors for more realistic risk estimation. The unlimited investment in power generation and/or cooling technologies is also found to save water and GHG emissions by 68% and 75% respectively at a marginal levelized cost increase of 12%. In contrast, the zero investment scenarios (which optimizes exiting technologies to address water scarcity constraints on power generation) shows 50% water savings and 23% GHG emissions reduction at a relatively high marginal levelized cost increase of 37%. Water saving strategies in electric sector show very high cost of water savings (48,000 and 200,000)/Mgal-year under unlimited investment and zero investment scenarios respectively, but they have greater water saving impacts of 6% to CSU municipal water demand; while the individual water saving strategies from water sector have low cost of water savings ranging from (37-1,500)/Mgal-year but with less than 0.5% water reduction impact to CSU due to their low penetration. On the other hand, use of reclaimed water for power plant cooling systems have shown great water savings of up to 92% against the BAU and cost of water saving from (0-73,000)/Mgal-year when integrated with unlimited investment and zero investment water minimizing scenarios respectively in the electric sector. Overall, cities need to focus primarily on use of reclaimed water and in new generation technologies' investment including cooling system retrofits while focusing on expanding the penetration rate of individual water saving strategies in the water sector.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Guodong; Ollis, Thomas B.; Xiao, Bailu
Here, this paper proposes a Mixed Integer Conic Programming (MICP) model for community microgrids considering the network operational constraints and building thermal dynamics. The proposed optimization model optimizes not only the operating cost, including fuel cost, purchasing cost, battery degradation cost, voluntary load shedding cost and the cost associated with customer discomfort due to room temperature deviation from the set point, but also several performance indices, including voltage deviation, network power loss and power factor at the Point of Common Coupling (PCC). In particular, the detailed thermal dynamic model of buildings is integrated into the distribution optimal power flow (D-OPF)more » model for the optimal operation of community microgrids. The heating, ventilation and air-conditioning (HVAC) systems can be scheduled intelligently to reduce the electricity cost while maintaining the indoor temperature in the comfort range set by customers. Numerical simulation results show the effectiveness of the proposed model and significant saving in electricity cost could be achieved with network operational constraints satisfied.« less
Liu, Guodong; Ollis, Thomas B.; Xiao, Bailu; ...
2017-10-10
Here, this paper proposes a Mixed Integer Conic Programming (MICP) model for community microgrids considering the network operational constraints and building thermal dynamics. The proposed optimization model optimizes not only the operating cost, including fuel cost, purchasing cost, battery degradation cost, voluntary load shedding cost and the cost associated with customer discomfort due to room temperature deviation from the set point, but also several performance indices, including voltage deviation, network power loss and power factor at the Point of Common Coupling (PCC). In particular, the detailed thermal dynamic model of buildings is integrated into the distribution optimal power flow (D-OPF)more » model for the optimal operation of community microgrids. The heating, ventilation and air-conditioning (HVAC) systems can be scheduled intelligently to reduce the electricity cost while maintaining the indoor temperature in the comfort range set by customers. Numerical simulation results show the effectiveness of the proposed model and significant saving in electricity cost could be achieved with network operational constraints satisfied.« less
Optimal Coordination of Building Loads and Energy Storage for Power Grid and End User Services
Hao, He; Wu, Di; Lian, Jianming; ...
2017-01-18
Demand response and energy storage play a profound role in the smart grid. The focus of this study is to evaluate benefits of coordinating flexible loads and energy storage to provide power grid and end user services. We present a Generalized Battery Model (GBM) to describe the flexibility of building loads and energy storage. An optimization-based approach is proposed to characterize the parameters (power and energy limits) of the GBM for flexible building loads. We then develop optimal coordination algorithms to provide power grid and end user services such as energy arbitrage, frequency regulation, spinning reserve, as well as energymore » cost and demand charge reduction. Several case studies have been performed to demonstrate the efficacy of the GBM and coordination algorithms, and evaluate the benefits of using their flexibility for power grid and end user services. We show that optimal coordination yields significant cost savings and revenue. Moreover, the best option for power grid services is to provide energy arbitrage and frequency regulation. Finally and furthermore, when coordinating flexible loads with energy storage to provide end user services, it is recommended to consider demand charge in addition to time-of-use price in order to flatten the aggregate power profile.« less
Real Time Voltage and Current Phase Shift Analyzer for Power Saving Applications
Krejcar, Ondrej; Frischer, Robert
2012-01-01
Nowadays, high importance is given to low energy devices (such as refrigerators, deep-freezers, washing machines, pumps, etc.) that are able to produce reactive power in power lines which can be optimized (reduced). Reactive power is the main component which overloads power lines and brings excessive thermal stress to conductors. If the reactive power is optimized, it can significantly lower the electricity consumption (from 10 to 30%—varies between countries). This paper will examine and discuss the development of a measuring device for analyzing reactive power. However, the main problem is the precise real time measurement of the input and output voltage and current. Such quality measurement is needed to allow adequate action intervention (feedback which reduces or fully compensates reactive power). Several other issues, such as the accuracy and measurement speed, must be examined while designing this device. The price and the size of the final product need to remain low as they are the two important parameters of this solution. PMID:23112662
Practical Considerations of Waste Heat Reuse for a Mars Mission Advanced Life Support System
NASA Technical Reports Server (NTRS)
Levri, Julie; Finn, Cory; Luna, Bernadette (Technical Monitor)
2000-01-01
Energy conservation is a key issue in design optimization of Advanced Life Support Systems (ALSS) for long-term space missions. By considering designs for conservation at the system level, energy saving opportunities arise that would otherwise go unnoticed. This paper builds on a steady-state investigation of system-level waste heat reuse in an ALSS with a low degree of crop growth for a Mars mission. In past studies, such a system has been defined in terms of technology types, hot and cold stream identification and stream energy content. The maximum steady-state potential for power and cooling savings within the system was computed via the Pinch Method. In this paper, several practical issues are considered for achieving a pragmatic estimate of total system savings in terms of equivalent system mass (ESM), rather than savings solely in terms of power and cooling. In this paper, more realistic ESM savings are computed by considering heat transfer inefficiencies during material transfer. An estimate of the steady-state mass, volume and crewtime requirements associated with heat exchange equipment is made by considering heat exchange equipment material type and configuration, stream flow characteristics and associated energy losses during the heat exchange process. Also, previously estimated power and cooling savings are adjusted to reflect the impact of such energy losses. This paper goes one step further than the traditional Pinch Method of considering waste heat reuse in heat exchangers to include ESM savings that occur with direct reuse of a stream. For example, rather than exchanging heat between crop growth lamp cooling air and air going to a clothes dryer, air used to cool crop lamps might be reused directly for clothes drying purposes. When thermodynamically feasible, such an approach may increase ESM savings by minimizing the mass, volume and crewtime requirements associated with stream routing equipment.
NASA Astrophysics Data System (ADS)
Sinaga, R. H. M.; Darmanto, P. S.
2016-09-01
Darajat unit III geothermal power plant is developed by PT. Chevron Geothermal Indonesia (CGI). The plant capacity is 121 MW and load 110%. The greatest utilization power is consumed by Hot Well Pump (HWP) and Cooling Tower Fan (CTF). Reducing the utility power can be attempted by utilizing the wet bulb temperature fluctuation. In this study, a modelling process is developed by using Engineering Equation Solver (EES) software version 9.430.The possibility of energy saving is indicated by Specific Steam Consumption (SSC) net in relation to wet bulb temperature fluctuation from 9°C up to 20.5°C. Result shows that the existing daily operation reaches its optimum condition. The installation of Variable Frequency Drive (VFD) could be applied to optimize both utility power of HWP and CTF. The highest gain is obtained by VFD HWP installation as much as 0.80% when wet bulb temperature 18.5 °C.
Solar-Diesel Hybrid Power System Optimization and Experimental Validation
NASA Astrophysics Data System (ADS)
Jacobus, Headley Stewart
As of 2008 1.46 billion people, or 22 percent of the World's population, were without electricity. Many of these people live in remote areas where decentralized generation is the only method of electrification. Most mini-grids are powered by diesel generators, but new hybrid power systems are becoming a reliable method to incorporate renewable energy while also reducing total system cost. This thesis quantifies the measurable Operational Costs for an experimental hybrid power system in Sierra Leone. Two software programs, Hybrid2 and HOMER, are used during the system design and subsequent analysis. Experimental data from the installed system is used to validate the two programs and to quantify the savings created by each component within the hybrid system. This thesis bridges the gap between design optimization studies that frequently lack subsequent validation and experimental hybrid system performance studies.
Energy saving and consumption reducing evaluation of thermal power plant
NASA Astrophysics Data System (ADS)
Tan, Xiu; Han, Miaomiao
2018-03-01
At present, energy saving and consumption reduction require energy saving and consumption reduction measures for thermal power plant, establishing an evaluation system for energy conservation and consumption reduction is instructive for the whole energy saving work of thermal power plant. By analysing the existing evaluation system of energy conservation and consumption reduction, this paper points out that in addition to the technical indicators of power plant, market activities should also be introduced in the evaluation of energy saving and consumption reduction in power plant. Ttherefore, a new evaluation index of energy saving and consumption reduction is set up and the example power plant is calculated in this paper. Rresults show that after introducing the new evaluation index of energy saving and consumption reduction, the energy saving effect of the power plant can be judged more comprehensively, so as to better guide the work of energy saving and consumption reduction in power plant.
Energy aware swarm optimization with intercluster search for wireless sensor network.
Thilagavathi, Shanmugasundaram; Geetha, Bhavani Gnanasambandan
2015-01-01
Wireless sensor networks (WSNs) are emerging as a low cost popular solution for many real-world challenges. The low cost ensures deployment of large sensor arrays to perform military and civilian tasks. Generally, WSNs are power constrained due to their unique deployment method which makes replacement of battery source difficult. Challenges in WSN include a well-organized communication platform for the network with negligible power utilization. In this work, an improved binary particle swarm optimization (PSO) algorithm with modified connected dominating set (CDS) based on residual energy is proposed for discovery of optimal number of clusters and cluster head (CH). Simulations show that the proposed BPSO-T and BPSO-EADS perform better than LEACH- and PSO-based system in terms of energy savings and QOS.
Analysis of optimal design of low temperature economizer
NASA Astrophysics Data System (ADS)
Song, J. H.; Wang, S.
2017-11-01
This paper has studied the Off-design characteristic of low temperature economizer system based on thermodynamics analysis. Based on the data from one 1000 MW coal-fired unit, two modes of operation are contrasted and analyzed. One is to fix exhaust gas temperature and the other one is to take into account both of the average temperature difference and the exhaust gas temperature. Meanwhile, the cause of energy saving effect change is explored. Result shows that: in mode 1, the amount of decrease in coal consumption reduces from 1.11 g/kWh (under full load) to 0.54 g/kWh (under half load), and in mode 2, when the load decreases from 90% to 50%, the decrease in coal consumption reduces from 1.29 g/kWh to 0.84 g/kWh. From the result, under high load, the energy saving effect is superior, and under lower work load, energy saving effect declines rapidly when load is reduced. When load changes, the temperature difference of heat transfer, gas flow, the flue gas heat rejection and the waste heat recovery change. The energy saving effect corresponding changes result in that the energy saving effect under high load is superior and more stable. However, rational adjustment to the temperature of outlet gas can alleviate the decline of the energy saving effect under low load. The result provides theoretical analysis data for the optimal design and operation of low temperature economizer system of power plant.
Evaluating the Investment Potential of HSAs in Benefit Programs.
LaFleur, James; Magner, Liana; Domaszewicz, Sander
Despite its complexities, the health savings account (HSA) is a powerful and growing element of the U.S. financial landscape. In the future, employers will likely be expected to provide tax-advantaged savings programs for employees' current and future medical expenses. This article discusses investment lineup issues that must be addressed in order to optimize HSAs to help participants achieve successful outcomes. Plan sponsors at the forefront of addressing these issues (and perhaps others) will be in a better position to help their employees maximize both the health benefits and the wealth benefits provided for a secure retirement.
No Cost – Low Cost Compressed Air System Optimization in Industry
NASA Astrophysics Data System (ADS)
Dharma, A.; Budiarsa, N.; Watiniasih, N.; Antara, N. G.
2018-04-01
Energy conservation is a systematic, integrated of effort, in order to preserve energy sources and improve energy utilization efficiency. Utilization of energy in efficient manner without reducing the energy usage it must. Energy conservation efforts are applied at all stages of utilization, from utilization of energy resources to final, using efficient technology, and cultivating an energy-efficient lifestyle. The most common way is to promote energy efficiency in the industry on end use and overcome barriers to achieve such efficiency by using system energy optimization programs. The facts show that energy saving efforts in the process usually only focus on replacing tools and not an overall system improvement effort. In this research, a framework of sustainable energy reduction work in companies that have or have not implemented energy management system (EnMS) will be conducted a systematic technical approach in evaluating accurately a compressed-air system and potential optimization through observation, measurement and verification environmental conditions and processes, then processing the physical quantities of systems such as air flow, pressure and electrical power energy at any given time measured using comparative analysis methods in this industry, to provide the potential savings of energy saving is greater than the component approach, with no cost to the lowest cost (no cost - low cost). The process of evaluating energy utilization and energy saving opportunities will provide recommendations for increasing efficiency in the industry and reducing CO2 emissions and improving environmental quality.
Cotes-Ruiz, Iván Tomás; Prado, Rocío P.; García-Galán, Sebastián; Muñoz-Expósito, José Enrique; Ruiz-Reyes, Nicolás
2017-01-01
Nowadays, the growing computational capabilities of Cloud systems rely on the reduction of the consumed power of their data centers to make them sustainable and economically profitable. The efficient management of computing resources is at the heart of any energy-aware data center and of special relevance is the adaptation of its performance to workload. Intensive computing applications in diverse areas of science generate complex workload called workflows, whose successful management in terms of energy saving is still at its beginning. WorkflowSim is currently one of the most advanced simulators for research on workflows processing, offering advanced features such as task clustering and failure policies. In this work, an expected power-aware extension of WorkflowSim is presented. This new tool integrates a power model based on a computing-plus-communication design to allow the optimization of new management strategies in energy saving considering computing, reconfiguration and networks costs as well as quality of service, and it incorporates the preeminent strategy for on host energy saving: Dynamic Voltage Frequency Scaling (DVFS). The simulator is designed to be consistent in different real scenarios and to include a wide repertory of DVFS governors. Results showing the validity of the simulator in terms of resources utilization, frequency and voltage scaling, power, energy and time saving are presented. Also, results achieved by the intra-host DVFS strategy with different governors are compared to those of the data center using a recent and successful DVFS-based inter-host scheduling strategy as overlapped mechanism to the DVFS intra-host technique. PMID:28085932
Cotes-Ruiz, Iván Tomás; Prado, Rocío P; García-Galán, Sebastián; Muñoz-Expósito, José Enrique; Ruiz-Reyes, Nicolás
2017-01-01
Nowadays, the growing computational capabilities of Cloud systems rely on the reduction of the consumed power of their data centers to make them sustainable and economically profitable. The efficient management of computing resources is at the heart of any energy-aware data center and of special relevance is the adaptation of its performance to workload. Intensive computing applications in diverse areas of science generate complex workload called workflows, whose successful management in terms of energy saving is still at its beginning. WorkflowSim is currently one of the most advanced simulators for research on workflows processing, offering advanced features such as task clustering and failure policies. In this work, an expected power-aware extension of WorkflowSim is presented. This new tool integrates a power model based on a computing-plus-communication design to allow the optimization of new management strategies in energy saving considering computing, reconfiguration and networks costs as well as quality of service, and it incorporates the preeminent strategy for on host energy saving: Dynamic Voltage Frequency Scaling (DVFS). The simulator is designed to be consistent in different real scenarios and to include a wide repertory of DVFS governors. Results showing the validity of the simulator in terms of resources utilization, frequency and voltage scaling, power, energy and time saving are presented. Also, results achieved by the intra-host DVFS strategy with different governors are compared to those of the data center using a recent and successful DVFS-based inter-host scheduling strategy as overlapped mechanism to the DVFS intra-host technique.
NASA Astrophysics Data System (ADS)
Hwang, Eunju; Kim, Kyung Jae; Choi, Bong Dae
In IEEE 802.16e, power saving is one of the important issues for battery-powered mobile stations (MSs). We present a performance analysis of power saving class (PSC) of type I in IEEE 802.16e standard for voice over Internet protocol (VoIP) service with silence suppression in two-way communication. On-off pattern of a voice user in two-way communication is characterized by the modified Brady model, which includes short silence gaps less than 200ms and talkspurt periods shorter than 15ms, and so differs from the Brady model. Our analysis of PSC I follows the standard-based procedure for the deactivation of the sleep mode, where a uplink packet arrival during a mutual silence period wakes up the MS immediately while a downlink packet arrival waits to be served until the next listening window. We derive the delay distribution of the first downlink packet arriving during a mutual silence period, and find the dropping probability of downlink packets since a voice packet drops if it is not transmitted within maximum delay constraint. In addition, we calculate the average power consumption under the modified Brady model. Analysis and simulation results show that the sleep mode operation for the MS with VoIP service yields 32 ∼ 39% reduction in the power consumption of the MS. Finally we obtain the optimal initial/final-sleep windows that yield the minimum average power consumption while satisfying QoS constraints on the packet dropping probability and the maximum delay.
ONU Power Saving Scheme for EPON System
NASA Astrophysics Data System (ADS)
Mukai, Hiroaki; Tano, Fumihiko; Tanaka, Masaki; Kozaki, Seiji; Yamanaka, Hideaki
PON (Passive Optical Network) achieves FTTH (Fiber To The Home) economically, by sharing an optical fiber among plural subscribers. Recently, global climate change has been recognized as a serious near term problem. Power saving techniques for electronic devices are important. In PON system, the ONU (Optical Network Unit) power saving scheme has been studied and defined in XG-PON. In this paper, we propose an ONU power saving scheme for EPON. Then, we present an analysis of the power reduction effect and the data transmission delay caused by the ONU power saving scheme. According to the analysis, we propose an efficient provisioning method for the ONU power saving scheme which is applicable to both of XG-PON and EPON.
Energy Center Structure Optimization by using Smart Technologies in Process Control System
NASA Astrophysics Data System (ADS)
Shilkina, Svetlana V.
2018-03-01
The article deals with practical application of fuzzy logic methods in process control systems. A control object - agroindustrial greenhouse complex, which includes its own energy center - is considered. The paper analyzes object power supply options taking into account connection to external power grids and/or installation of own power generating equipment with various layouts. The main problem of a greenhouse facility basic process is extremely uneven power consumption, which forces to purchase redundant generating equipment idling most of the time, which quite negatively affects project profitability. Energy center structure optimization is largely based on solving the object process control system construction issue. To cut investor’s costs it was proposed to optimize power consumption by building an energy-saving production control system based on a fuzzy logic controller. The developed algorithm of automated process control system functioning ensured more even electric and thermal energy consumption, allowed to propose construction of the object energy center with a smaller number of units due to their more even utilization. As a result, it is shown how practical use of microclimate parameters fuzzy control system during object functioning leads to optimization of agroindustrial complex energy facility structure, which contributes to a significant reduction in object construction and operation costs.
An Efficient Power Saving Mechanism for Delay-Guaranteed Services in IEEE 802.16e
NASA Astrophysics Data System (ADS)
Park, Yunju; Hwang, Gang Uk
As the IEEE 802.16e Wireless Metropolitan Access Network (WMAN) supports the mobility of a mobile station (MS), increasing MS power efficiency has become an important issue. In this paper, we analyze the sleep-mode operation for an efficient power saving mechanism for delay-guaranteed services in the IEEE 802.16e WMAN and observe the effects of the operating parameters related to this operation. For the analysis we use the M/GI/1/K queueing system with multiple vacations, exhaustive services and setup times. In the analysis, we consider the power consumption during the wake-mode period as well as the sleep-mode period. As a performance measure for the power consumption, we propose the power consumption per unit time per effective arrival which considers the power consumption and the packet blocking probability simultaneously. In addition, since we consider delay-guaranteed services, the average packet response delay is also considered as a performance measure. Based on the performance measures, we obtain the optimal sleep-mode operation which minimizes the power consumption per unit time per effective arrival with a given delay requirement. Numerical studies are also provided to investigate the system performance and to show how to achieve our objective.
Color enhancement for portable LCD displays in low-power mode
NASA Astrophysics Data System (ADS)
Shih, Kuang-Tsu; Huang, Tai-Hsiang; Chen, Homer H.
2011-09-01
Switching the backlight of handheld devices to low power mode saves energy but affects the color appearance of an image. In this paper, we consider the chroma degradation problem and propose an enhancement algorithm that incorporates the CIECAM02 appearance model to quantitatively characterize the problem. In the proposed algorithm, we enhance the color appearance of the image in low power mode by weighted linear superposition of the chroma of the image and that of the estimated dim-backlight image. Subjective tests are carried out to determine the perceptually optimal weighting and prove the effectiveness of our framework.
Optimization of the oxidant supply system for combined cycle MHD power plants
NASA Technical Reports Server (NTRS)
Juhasz, A. J.
1982-01-01
An in-depth study was conducted to determine what, if any, improvements could be made on the oxidant supply system for combined cycle MHD power plants which could be reflected in higher thermal efficiency and a reduction in the cost of electricity, COE. A systematic analysis of air separation process varitions which showed that the specific energy consumption could be minimized when the product stream oxygen concentration is about 70 mole percent was conducted. The use of advanced air compressors, having variable speed and guide vane position control, results in additional power savings. The study also led to the conceptual design of a new air separation process, sized for a 500 MW sub e MHD plant, referred to a internal compression is discussed. In addition to its lower overall energy consumption, potential capital cost savings were identified for air separation plants using this process when constructed in a single large air separation train rather than multiple parallel trains, typical of conventional practice.
NASA Technical Reports Server (NTRS)
Eder, D.
1992-01-01
Parametric models were constructed for Earth-based laser powered electric orbit transfer from low Earth orbit to geosynchronous orbit. These models were used to carry out performance, cost/benefit, and sensitivity analyses of laser-powered transfer systems including end-to-end life cycle cost analyses for complete systems. Comparisons with conventional orbit transfer systems were made indicating large potential cost savings for laser-powered transfer. Approximate optimization was done to determine best parameter values for the systems. Orbit transfer flights simulations were conducted to explore effects of parameters not practical to model with a spreadsheet. The simulations considered view factors that determine when power can be transferred from ground stations to an orbit transfer vehicle and conducted sensitivity analyses for numbers of ground stations, Isp including dual-Isp transfers, and plane change profiles. Optimal steering laws were used for simultaneous altitude and plane change. Viewing geometry and low-thrust orbit raising were simultaneously simulated. A very preliminary investigation of relay mirrors was made.
NASA Astrophysics Data System (ADS)
Kant Garg, Girish; Garg, Suman; Sangwan, K. S.
2018-04-01
The manufacturing sector consumes huge energy demand and the machine tools used in this sector have very less energy efficiency. Selection of the optimum machining parameters for machine tools is significant for energy saving and for reduction of environmental emission. In this work an empirical model is developed to minimize the power consumption using response surface methodology. The experiments are performed on a lathe machine tool during the turning of AISI 6061 Aluminum with coated tungsten inserts. The relationship between the power consumption and machining parameters is adequately modeled. This model is used for formulation of minimum power consumption criterion as a function of optimal machining parameters using desirability function approach. The influence of machining parameters on the energy consumption has been found using the analysis of variance. The validation of the developed empirical model is proved using the confirmation experiments. The results indicate that the developed model is effective and has potential to be adopted by the industry for minimum power consumption of machine tools.
Energy-saving approaches to solid state street lighting
NASA Astrophysics Data System (ADS)
Vitta, Pranciškus; Stanikūnas, Rytis; Tuzikas, Arūnas; Reklaitis, Ignas; Stonkus, Andrius; Petrulis, Andrius; Vaitkevičius, Henrikas; Žukauskas, Artūras
2011-10-01
We consider the energy-saving potential of solid-state street lighting due to improved visual performance, weather sensitive luminance control and tracking of pedestrians and vehicles. A psychophysical experiment on the measurement of reaction time with a decision making task was performed under mesopic levels of illumination provided by a highpressure sodium (HPS) lamp and different solid-state light sources, such as daylight and warm-white phosphor converted light-emitting diodes (LEDs) and red-green-blue LED clusters. The results of the experiment imply that photopic luminances of road surface provided by solid-state light sources with an optimized spectral power distribution might be up to twice as low as those provided by the HPS lamp. Dynamical correction of road luminance against road surface conditions typical of Lithuanian climate was estimated to save about 20% of energy in comparison with constant-level illumination. The estimated energy savings due to the tracking of pedestrians and vehicles amount at least 25% with the cumulative effect of intelligent control of at least 40%. A solid-state street lighting system with intelligent control was demonstrated using a 300 m long test ground consisting of 10 solid-state street luminaires, a meteorological station and microwave motion sensor network operated via power line communication.
Maximum thrust mode evaluation
NASA Technical Reports Server (NTRS)
Orme, John S.; Nobbs, Steven G.
1995-01-01
Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.
Energy saving effects of wireless sensor networks: a case study of convenience stores in Taiwan.
Chen, Chih-Sheng; Lee, Da-Sheng
2011-01-01
Wireless sensor network (WSN) technology has been successfully applied to energy saving applications in many places, and plays a significant role in achieving power conservation. However, previous studies do not discuss WSN costs and cost-recovery. The application of WSNs is currently limited to research and laboratory experiments, and not mass industrial production, largely because business owners are unfamiliar with the possible favorable return and cost-recovery on WSN investments. Therefore, this paper focuses on the cost-recovery of WSNs and how to reduce air conditioning energy consumption in convenience stores. The WSN used in this study provides feedback to the gateway and adopts the predicted mean vote (PMV) and computational fluid dynamics (CFD) methods to allow customers to shop in a comfortable yet energy-saving environment. Four convenience stores in Taipei have used the proposed WSN since 2008. In 2008, the experiment was initially designed to optimize air-conditioning for energy saving, but additions to the set-up continued beyond 2008, adding the thermal comfort and crowds peak, off-peak features in 2009 to achieve human-friendly energy savings. Comparison with 2007 data, under the same comfort conditions, shows that the power savings increased by 40% (2008) and 53% (2009), respectively. The cost of the WSN equipment was 500 US dollars. Experimental results, including three years of analysis and calculations, show that the marginal energy conservation benefit of the four convenience stores achieved energy savings of up to 53%, recovering all costs in approximately 5 months. The convenience store group participating in this study was satisfied with the efficiency of energy conservation because of the short cost-recovery period.
Energy Saving Effects of Wireless Sensor Networks: A Case Study of Convenience Stores in Taiwan
Chen, Chih-Sheng; Lee, Da-Sheng
2011-01-01
Wireless sensor network (WSN) technology has been successfully applied to energy saving applications in many places, and plays a significant role in achieving power conservation. However, previous studies do not discuss WSN costs and cost-recovery. The application of WSNs is currently limited to research and laboratory experiments, and not mass industrial production, largely because business owners are unfamiliar with the possible favorable return and cost-recovery on WSN investments. Therefore, this paper focuses on the cost-recovery of WSNs and how to reduce air conditioning energy consumption in convenience stores. The WSN used in this study provides feedback to the gateway and adopts the predicted mean vote (PMV) and computational fluid dynamics (CFD) methods to allow customers to shop in a comfortable yet energy-saving environment. Four convenience stores in Taipei have used the proposed WSN since 2008. In 2008, the experiment was initially designed to optimize air-conditioning for energy saving, but additions to the set-up continued beyond 2008, adding the thermal comfort and crowds peak, off-peak features in 2009 to achieve human-friendly energy savings. Comparison with 2007 data, under the same comfort conditions, shows that the power savings increased by 40% (2008) and 53% (2009), respectively. The cost of the WSN equipment was 500 US dollars. Experimental results, including three years of analysis and calculations, show that the marginal energy conservation benefit of the four convenience stores achieved energy savings of up to 53%, recovering all costs in approximately 5 months. The convenience store group participating in this study was satisfied with the efficiency of energy conservation because of the short cost-recovery period. PMID:22319396
Aerodynamics of a Cycling Team in a Time Trial: Does the Cyclist at the Front Benefit?
ERIC Educational Resources Information Center
Iniguez-de-la Torre, A.; Iniguez, J.
2009-01-01
When seasonal journeys take place in nature, birds and fishes migrate in groups. This provides them not only with security but also a considerable saving of energy. The power they need to travel requires overcoming aerodynamic or hydrodynamic drag forces, which can be substantially reduced when the group travels in an optimal arrangement. Also in…
Long-Run Savings and Investment Strategy Optimization
Gerrard, Russell; Guillén, Montserrat; Pérez-Marín, Ana M.
2014-01-01
We focus on automatic strategies to optimize life cycle savings and investment. Classical optimal savings theory establishes that, given the level of risk aversion, a saver would keep the same relative amount invested in risky assets at any given time. We show that, when optimizing lifecycle investment, performance and risk assessment have to take into account the investor's risk aversion and the maximum amount the investor could lose, simultaneously. When risk aversion and maximum possible loss are considered jointly, an optimal savings strategy is obtained, which follows from constant rather than relative absolute risk aversion. This result is fundamental to prove that if risk aversion and the maximum possible loss are both high, then holding a constant amount invested in the risky asset is optimal for a standard lifetime saving/pension process and outperforms some other simple strategies. Performance comparisons are based on downside risk-adjusted equivalence that is used in our illustration. PMID:24711728
Long-run savings and investment strategy optimization.
Gerrard, Russell; Guillén, Montserrat; Nielsen, Jens Perch; Pérez-Marín, Ana M
2014-01-01
We focus on automatic strategies to optimize life cycle savings and investment. Classical optimal savings theory establishes that, given the level of risk aversion, a saver would keep the same relative amount invested in risky assets at any given time. We show that, when optimizing lifecycle investment, performance and risk assessment have to take into account the investor's risk aversion and the maximum amount the investor could lose, simultaneously. When risk aversion and maximum possible loss are considered jointly, an optimal savings strategy is obtained, which follows from constant rather than relative absolute risk aversion. This result is fundamental to prove that if risk aversion and the maximum possible loss are both high, then holding a constant amount invested in the risky asset is optimal for a standard lifetime saving/pension process and outperforms some other simple strategies. Performance comparisons are based on downside risk-adjusted equivalence that is used in our illustration.
The Power of Flexibility: Autonomous Agents That Conserve Energy in Commercial Buildings
NASA Astrophysics Data System (ADS)
Kwak, Jun-young
Agent-based systems for energy conservation are now a growing area of research in multiagent systems, with applications ranging from energy management and control on the smart grid, to energy conservation in residential buildings, to energy generation and dynamic negotiations in distributed rural communities. Contributing to this area, my thesis presents new agent-based models and algorithms aiming to conserve energy in commercial buildings. More specifically, my thesis provides three sets of algorithmic contributions. First, I provide online predictive scheduling algorithms to handle massive numbers of meeting/event scheduling requests considering flexibility , which is a novel concept for capturing generic user constraints while optimizing the desired objective. Second, I present a novel BM-MDP ( Bounded-parameter Multi-objective Markov Decision Problem) model and robust algorithms for multi-objective optimization under uncertainty both at the planning and execution time. The BM-MDP model and its robust algorithms are useful in (re)scheduling events to achieve energy efficiency in the presence of uncertainty over user's preferences. Third, when multiple users contribute to energy savings, fair division of credit for such savings to incentivize users for their energy saving activities arises as an important question. I appeal to cooperative game theory and specifically to the concept of Shapley value for this fair division. Unfortunately, scaling up this Shapley value computation is a major hindrance in practice. Therefore, I present novel approximation algorithms to efficiently compute the Shapley value based on sampling and partitions and to speed up the characteristic function computation. These new models have not only advanced the state of the art in multiagent algorithms, but have actually been successfully integrated within agents dedicated to energy efficiency: SAVES, TESLA and THINC. SAVES focuses on the day-to-day energy consumption of individuals and groups in commercial buildings by reactively suggesting energy conserving alternatives. TESLA takes a long-range planning perspective and optimizes overall energy consumption of a large number of group events or meetings together. THINC provides an end-to-end integration within a single agent of energy efficient scheduling, rescheduling and credit allocation. While SAVES, TESLA and THINC thus differ in their scope and applicability, they demonstrate the utility of agent-based systems in actually reducing energy consumption in commercial buildings. I evaluate my algorithms and agents using extensive analysis on data from over 110,000 real meetings/events at multiple educational buildings including the main libraries at the University of Southern California. I also provide results on simulations and real-world experiments, clearly demonstrating the power of agent technology to assist human users in saving energy in commercial buildings.
CPU architecture for a fast and energy-saving calculation of convolution neural networks
NASA Astrophysics Data System (ADS)
Knoll, Florian J.; Grelcke, Michael; Czymmek, Vitali; Holtorf, Tim; Hussmann, Stephan
2017-06-01
One of the most difficult problem in the use of artificial neural networks is the computational capacity. Although large search engine companies own specially developed hardware to provide the necessary computing power, for the conventional user only remains the state of the art method, which is the use of a graphic processing unit (GPU) as a computational basis. Although these processors are well suited for large matrix computations, they need massive energy. Therefore a new processor on the basis of a field programmable gate array (FPGA) has been developed and is optimized for the application of deep learning. This processor is presented in this paper. The processor can be adapted for a particular application (in this paper to an organic farming application). The power consumption is only a fraction of a GPU application and should therefore be well suited for energy-saving applications.
Wellmann, Peter J
2017-11-17
Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies.
2017-01-01
Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies. PMID:29200530
A study of optical design of power-saving backlight module with external illuminance
NASA Astrophysics Data System (ADS)
Fang, Yi-Chin; Tzeng, Yih-Fong
2014-05-01
In backlight modules, the light guide plate (LGP) is a key component for performance and also facilitates access to develop LGPs on its own. In this research, we propose a newly developed method: LEDs with freeform as a lighting source, are employed to integrate and manipulate the specially designed and optimized 3D-like pattern distribution of the micro features in order to obtain the required optical characteristics at maximal performance. In this research propose the concept of Light Guide Film(LGF) at the back side of Back Light Unit(BLU). This new design may induce the exterior light ,then improve the power-saving of existent BLU. Two design models are reseated: One is design for 14 inch LCD monitor of notebook computer, which might improve 21% compared to traditional one. Another is designed for 3.5 inch LCD for mobile phone display ,which might improve 15% compared to traditional one.
Research and application of key technology of electric submersible plunger pump
NASA Astrophysics Data System (ADS)
Qian, K.; Sun, Y. N.; Zheng, S.; Du, W. S.; Li, J. N.; Pei, G. Z.; Gao, Y.; Wu, N.
2018-06-01
Electric submersible plunger pump is a new generation of rodless oil production equipment, whose improvements and upgrades of key technologies are conducive to its large-scale application and reduce the cost and improve the efficiency. In this paper, the operating mechanism of the unit in-depth study, aimed at the problems existing in oilfield production, to propose an optimization method creatively, including the optimal design of a linear motor for submersible oil, development of new double-acting load-relief pump, embedded flexible closed-loop control technology, research and development of low-cost power cables. 90 oil wells were used on field application, the average pump inspection cycle is 608 days, the longest pump check cycle has exceeded 1037 days, the average power saving rate is 45.6%. Application results show that the new technology of optimization and upgrading can further improve the reliability and adaptability of electric submersible plunger pump, reduce the cost of investment.
Measured energy savings and performance of power-managed personal computers and monitors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nordman, B.; Piette, M.A.; Kinney, K.
1996-08-01
Personal computers and monitors are estimated to use 14 billion kWh/year of electricity, with power management potentially saving $600 million/year by the year 2000. The effort to capture these savings is lead by the US Environmental Protection Agency`s Energy Star program, which specifies a 30W maximum demand for the computer and for the monitor when in a {open_quote}sleep{close_quote} or idle mode. In this paper the authors discuss measured energy use and estimated savings for power-managed (Energy Star compliant) PCs and monitors. They collected electricity use measurements of six power-managed PCs and monitors in their office and five from two othermore » research projects. The devices are diverse in machine type, use patterns, and context. The analysis method estimates the time spent in each system operating mode (off, low-, and full-power) and combines these with real power measurements to derive hours of use per mode, energy use, and energy savings. Three schedules are explored in the {open_quotes}As-operated,{close_quotes} {open_quotes}Standardized,{close_quotes} and `Maximum` savings estimates. Energy savings are established by comparing the measurements to a baseline with power management disabled. As-operated energy savings for the eleven PCs and monitors ranged from zero to 75 kWh/year. Under the standard operating schedule (on 20% of nights and weekends), the savings are about 200 kWh/year. An audit of power management features and configurations for several dozen Energy Star machines found only 11% of CPU`s fully enabled and about two thirds of monitors were successfully power managed. The highest priority for greater power management savings is to enable monitors, as opposed to CPU`s, since they are generally easier to configure, less likely to interfere with system operation, and have greater savings. The difficulties in properly configuring PCs and monitors is the largest current barrier to achieving the savings potential from power management.« less
NASA Astrophysics Data System (ADS)
Bolorinos, J.; Ajami, N.; Yu, Y.; Rajagopal, R.
2016-12-01
Urban water supply and energy systems in the arid Southwestern United States are closely linked. Freshwater use by the electricity sector in particular represents a sizable portion of total water consumption in the region. Nonetheless, the dispatch of water and energy resources is managed separately, and no research to-date has examined the water conservation potential presented by the electricity sector. This study gauges the potential water savings that could be achieved including water use in the power dispatch process in Southern California by simulating a DC Optimal Power Flow for a simplified model of the region's power network. The simulation uses historical power consumption data, historical power production data and water use data from the US Geological Survey, the California Energy Commission and the US Energy Information Administration to estimate freshwater consumption by the region's thermoelectric power generation fleet. Preliminary results indicate that power system freshwater consumption could be reduced by as much as 20% at a minimal cost penalty, with potential for even greater savings. Model results show that Southern California's power system has the ability to competitively shift the use of some of the region's water resources from electricity to urban consumption, and suggests that water use should be incorporated into the policy-making process to enhance the efficient use of the state's interconnected water and energy resources.
NASA Astrophysics Data System (ADS)
Ataei, Milad; Robert, Christian; Boegli, Alexis; Farine, Pierre-André
2015-10-01
This paper describes a detailed design procedure for an efficient thermal body energy harvesting integrated power converter. The procedure is based on the examination of power loss and power transfer in a converter for a self-powered medical device. The efficiency limit for the system is derived and the converter is optimized for the worst case scenario. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. Circuit blocks including pulse generators are implemented based on the system specifications and optimized converter working frequency. At this working condition, it has been demonstrated that the wide area capacitor of the voltage doubler, which provides high voltage switch gating, can be eliminated at the expense of wider switches. With this method, measurements show that 54% efficiency is achieved for just a 20 mV transducer output voltage and 30% of the chip area is saved. The entire electronic board can fit in one EEG or ECG electrode, and the electronic system can convert the electrode to an active electrode.
A Two-Stage Stochastic Mixed-Integer Programming Approach to the Smart House Scheduling Problem
NASA Astrophysics Data System (ADS)
Ozoe, Shunsuke; Tanaka, Yoichi; Fukushima, Masao
A “Smart House” is a highly energy-optimized house equipped with photovoltaic systems (PV systems), electric battery systems, fuel cell cogeneration systems (FC systems), electric vehicles (EVs) and so on. Smart houses are attracting much attention recently thanks to their enhanced ability to save energy by making full use of renewable energy and by achieving power grid stability despite an increased power draw for installed PV systems. Yet running a smart house's power system, with its multiple power sources and power storages, is no simple task. In this paper, we consider the problem of power scheduling for a smart house with a PV system, an FC system and an EV. We formulate the problem as a mixed integer programming problem, and then extend it to a stochastic programming problem involving recourse costs to cope with uncertain electricity demand, heat demand and PV power generation. Using our method, we seek to achieve the optimal power schedule running at the minimum expected operation cost. We present some results of numerical experiments with data on real-life demands and PV power generation to show the effectiveness of our method.
Strategies to Save 50% Site Energy in Grocery and General Merchandise Stores
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hirsch, A.; Hale, E.; Leach, M.
2011-03-01
This paper summarizes the methodology and main results of two recently published Technical Support Documents. These reports explore the feasibility of designing general merchandise and grocery stores that use half the energy of a minimally code-compliant building, as measured on a whole-building basis. We used an optimization algorithm to trace out a minimum cost curve and identify designs that satisfy the 50% energy savings goal. We started from baseline building energy use and progressed to more energy-efficient designs by sequentially adding energy design measures (EDMs). Certain EDMs figured prominently in reaching the 50% energy savings goal for both building types:more » (1) reduced lighting power density; (2) optimized area fraction and construction of view glass or skylights, or both, as part of a daylighting system tuned to 46.5 fc (500 lux); (3) reduced infiltration with a main entrance vestibule or an envelope air barrier, or both; and (4) energy recovery ventilators, especially in humid and cold climates. In grocery stores, the most effective EDM, which was chosen for all climates, was replacing baseline medium-temperature refrigerated cases with high-efficiency models that have doors.« less
A modeling approach to energy savings of flying Canada geese using computational fluid dynamics.
Maeng, Joo-Sung; Park, Jae-Hyung; Jang, Seong-Min; Han, Seog-Young
2013-03-07
A flapping flight mechanism of the Canada goose (Branta canadensis) was estimated using a two-jointed arm model in unsteady aerodynamic performance to examine how much energy can be saved in migration. Computational fluid dynamics (CFD) was used to evaluate airflow fields around the wing and in the wake. From the distributions of velocity and pressure on the wing, it was found that about 15% of goose flight energy could be saved by drag reduction from changing the morphology of the wing. From the airflow field in the wake, it was found that a pair of three-dimensional spiral flapping advantage vortices (FAV) was alternately generated. We quantitatively deduced that the optimal depth (the distance along the flight path between birds) was around 4m from the wing tip of a goose ahead, and optimal wing tip spacing (WTS, the distance between wing tips of adjacent birds perpendicular to the flight path) ranged between 0 and -0.40m in the spanwise section. It was found that a goose behind can save about 16% of its energy by induced power from FAV in V-formation. The phase difference of flapping between the goose ahead and behind was estimated at around 90.7° to take full aerodynamic benefit caused by FAV. Copyright © 2012 Elsevier Ltd. All rights reserved.
A Low Power IoT Sensor Node Architecture for Waste Management Within Smart Cities Context.
Cerchecci, Matteo; Luti, Francesco; Mecocci, Alessandro; Parrino, Stefano; Peruzzi, Giacomo; Pozzebon, Alessandro
2018-04-21
This paper focuses on the realization of an Internet of Things (IoT) architecture to optimize waste management in the context of Smart Cities. In particular, a novel typology of sensor node based on the use of low cost and low power components is described. This node is provided with a single-chip microcontroller, a sensor able to measure the filling level of trash bins using ultrasounds and a data transmission module based on the LoRa LPWAN (Low Power Wide Area Network) technology. Together with the node, a minimal network architecture was designed, based on a LoRa gateway, with the purpose of testing the IoT node performances. Especially, the paper analyzes in detail the node architecture, focusing on the energy saving technologies and policies, with the purpose of extending the batteries lifetime by reducing power consumption, through hardware and software optimization. Tests on sensor and radio module effectiveness are also presented.
A Low Power IoT Sensor Node Architecture for Waste Management Within Smart Cities Context
Cerchecci, Matteo; Luti, Francesco; Mecocci, Alessandro; Parrino, Stefano; Peruzzi, Giacomo
2018-01-01
This paper focuses on the realization of an Internet of Things (IoT) architecture to optimize waste management in the context of Smart Cities. In particular, a novel typology of sensor node based on the use of low cost and low power components is described. This node is provided with a single-chip microcontroller, a sensor able to measure the filling level of trash bins using ultrasounds and a data transmission module based on the LoRa LPWAN (Low Power Wide Area Network) technology. Together with the node, a minimal network architecture was designed, based on a LoRa gateway, with the purpose of testing the IoT node performances. Especially, the paper analyzes in detail the node architecture, focusing on the energy saving technologies and policies, with the purpose of extending the batteries lifetime by reducing power consumption, through hardware and software optimization. Tests on sensor and radio module effectiveness are also presented. PMID:29690552
Power optimization in logic isomers
NASA Technical Reports Server (NTRS)
Panwar, Ramesh; Rennels, David; Alkalaj, Leon
1993-01-01
Logic isomers are labeled, 2-isomorphic graphs that implement the same logic function. Logic isomers may have significantly different power requirements even though they have the same number of transistors in the implementation. The power requirements of the isomers depend on the transition activity of the input signals. The power requirements of isomorphic graph isomers of n-input NAND and NOR gates are shown. Choosing the less power-consuming isomer instead of the others can yield significant power savings. Experimental results on a ripple-carry adder are presented to show that the implementation using the least power-consuming isomers requires approximately 10 percent less power than the implementation using the most power-consuming isomers. Simulations of other random logic designs also confirm that designs using less power-consuming isomers can reduce the logic power demand by approximately 10 percent as compared to designs using more power-consuming isomers.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Trocki, L.K.
1989-09-01
The expected economic benefits from development of a geothermal power plant at Platanares in the Department of Copan, Honduras are evaluated in this report. The economic benefits of geothermal plants ranging in size from a 10-MW plant in the shallow reservoir to a 20-, 30-, 55-, or 110-MW plant in the assumed deeper reservoir were measured by computing optimal expansion plans for each size of geothermal plant. Savings are computed as the difference in present value cost between a plan that contains no geothermal plant and one that does. Present value savings in millions of 1987 dollars range from $25more » million for the 10-MW plant to $110 million for the 110-MW plant -- savings of 6% to 25% over the time period 1988 through 2008. 8 refs., 9 figs., 6 tabs.« less
NASA Astrophysics Data System (ADS)
Shah, Rahul H.
Production costs account for the largest share of the overall cost of manufacturing facilities. With the U.S. industrial sector becoming more and more competitive, manufacturers are looking for more cost and resource efficient working practices. Operations management and production planning have shown their capability to dramatically reduce manufacturing costs and increase system robustness. When implementing operations related decision making and planning, two fields that have shown to be most effective are maintenance and energy. Unfortunately, the current research that integrates both is limited. Additionally, these studies fail to consider parameter domains and optimization on joint energy and maintenance driven production planning. Accordingly, production planning methodology that considers maintenance and energy is investigated. Two models are presented to achieve well-rounded operating strategy. The first is a joint energy and maintenance production scheduling model. The second is a cost per part model considering maintenance, energy, and production. The proposed methodology will involve a Time-of-Use electricity demand response program, buffer and holding capacity, station reliability, production rate, station rated power, and more. In practice, the scheduling problem can be used to determine a joint energy, maintenance, and production schedule. Meanwhile, the cost per part model can be used to: (1) test the sensitivity of the obtained optimal production schedule and its corresponding savings by varying key production system parameters; and (2) to determine optimal system parameter combinations when using the joint energy, maintenance, and production planning model. Additionally, a factor analysis on the system parameters is conducted and the corresponding performance of the production schedule under variable parameter conditions, is evaluated. Also, parameter optimization guidelines that incorporate maintenance and energy parameter decision making in the production planning framework are discussed. A modified Particle Swarm Optimization solution technique is adopted to solve the proposed scheduling problem. The algorithm is described in detail and compared to Genetic Algorithm. Case studies are presented to illustrate the benefits of using the proposed model and the effectiveness of the Particle Swarm Optimization approach. Numerical Experiments are implemented and analyzed to test the effectiveness of the proposed model. The proposed scheduling strategy can achieve savings of around 19 to 27 % in cost per part when compared to the baseline scheduling scenarios. By optimizing key production system parameters from the cost per part model, the baseline scenarios can obtain around 20 to 35 % in savings for the cost per part. These savings further increase by 42 to 55 % when system parameter optimization is integrated with the proposed scheduling problem. Using this method, the most influential parameters on the cost per part are the rated power from production, the production rate, and the initial machine reliabilities. The modified Particle Swarm Optimization algorithm adopted allows greater diversity and exploration compared to Genetic Algorithm for the proposed joint model which results in it being more computationally efficient in determining the optimal scheduling. While Genetic Algorithm could achieve a solution quality of 2,279.63 at an expense of 2,300 seconds in computational effort. In comparison, the proposed Particle Swarm Optimization algorithm achieved a solution quality of 2,167.26 in less than half the computation effort which is required by Genetic Algorithm.
Power-Aware Compiler Controllable Chip Multiprocessor
NASA Astrophysics Data System (ADS)
Shikano, Hiroaki; Shirako, Jun; Wada, Yasutaka; Kimura, Keiji; Kasahara, Hironori
A power-aware compiler controllable chip multiprocessor (CMP) is presented and its performance and power consumption are evaluated with the optimally scheduled advanced multiprocessor (OSCAR) parallelizing compiler. The CMP is equipped with power control registers that change clock frequency and power supply voltage to functional units including processor cores, memories, and an interconnection network. The OSCAR compiler carries out coarse-grain task parallelization of programs and reduces power consumption using architectural power control support and the compiler's power saving scheme. The performance evaluation shows that MPEG-2 encoding on the proposed CMP with four CPUs results in 82.6% power reduction in real-time execution mode with a deadline constraint on its sequential execution time. Furthermore, MP3 encoding on a heterogeneous CMP with four CPUs and four accelerators results in 53.9% power reduction at 21.1-fold speed-up in performance against its sequential execution in the fastest execution mode.
Optimal pitching axis location of flapping wings for efficient hovering flight.
Wang, Q; Goosen, J F L; van Keulen, F
2017-09-01
Flapping wings can pitch passively about their pitching axes due to their flexibility, inertia, and aerodynamic loads. A shift in the pitching axis location can dynamically alter the aerodynamic loads, which in turn changes the passive pitching motion and the flight efficiency. Therefore, it is of great interest to investigate the optimal pitching axis for flapping wings to maximize the power efficiency during hovering flight. In this study, flapping wings are modeled as rigid plates with non-uniform mass distribution. The wing flexibility is represented by a linearly torsional spring at the wing root. A predictive quasi-steady aerodynamic model is used to evaluate the lift generated by such wings. Two extreme power consumption scenarios are modeled for hovering flight, i.e. the power consumed by a drive system with and without the capacity of kinetic energy recovery. For wings with different shapes, the optimal pitching axis location is found such that the cycle-averaged power consumption during hovering flight is minimized. Optimization results show that the optimal pitching axis is located between the leading edge and the mid-chord line, which shows close resemblance to insect wings. An optimal pitching axis can save up to 33% of power during hovering flight when compared to traditional wings used by most of flapping wing micro air vehicles (FWMAVs). Traditional wings typically use the straight leading edge as the pitching axis. With the optimized pitching axis, flapping wings show higher pitching amplitudes and start the pitching reversals in advance of the sweeping reversals. These phenomena lead to higher lift-to-drag ratios and, thus, explain the lower power consumption. In addition, the optimized pitching axis provides the drive system higher potential to recycle energy during the deceleration phases as compared to their counterparts. This observation underlines the particular importance of the wing pitching axis location for energy-efficient FWMAVs when using kinetic energy recovery drive systems.
Energy consumption of agitators in activated sludge tanks - actual state and optimization potential.
Füreder, K; Svardal, K; Frey, W; Kroiss, H; Krampe, J
2018-02-01
Depending on design capacity, agitators consume about 5 to 20% of the total energy consumption of a wastewater treatment plant. Based on inhabitant-specific energy consumption (kWh PE 120 -1 a -1 ; PE 120 is population equivalent, assuming 120 g chemical oxygen demand per PE per day), power density (W m -3 ) and volume-specific energy consumption (Wh m -3 d -1 ) as evaluation indicators, this paper provides a sound contribution to understanding energy consumption and energy optimization potentials of agitators. Basically, there are two ways to optimize agitator operation: the reduction of the power density and the reduction of the daily operating time. Energy saving options range from continuous mixing with low power densities of 1 W m -3 to mixing by means of short, intense energy pulses (impulse aeration, impulse stirring). However, the following correlation applies: the shorter the duration of energy input, the higher the power density on the respective volume-specific energy consumption isoline. Under favourable conditions with respect to tank volume, tank geometry, aeration and agitator position, mixing energy can be reduced to 24 Wh m -3 d -1 and below. Additionally, it could be verified that power density of agitators stands in inverse relation to tank volume.
NASA Astrophysics Data System (ADS)
Vaskovskaya, T. A.
2014-12-01
This paper offers a new approach to the analysis of price signals from the wholesale electricity and capacity market that is based on the analysis of the influence exerted by input data used in the problem of optimization of the power system operating conditions, namely: parameters of a power grid and power-receiving equipment that might vary under the effect of control devices. It is shown that it would be possible to control nonregulated prices for electricity in the wholesale electricity market by varying the parameters of control devices and energy-receiving equipment. An increase in the effectiveness of power transmission and the cost-effective use of fuel-and-energy resources (energy saving) can become an additional effect of controlling the nonregulated prices.
Improved system integration for integrated gasification combined cycle (IGCC) systems.
Frey, H Christopher; Zhu, Yunhua
2006-03-01
Integrated gasification combined cycle (IGCC) systems are a promising technology for power generation. They include an air separation unit (ASU), a gasification system, and a gas turbine combined cycle power block, and feature competitive efficiency and lower emissions compared to conventional power generation technology. IGCC systems are not yet in widespread commercial use and opportunities remain to improve system feasibility via improved process integration. A process simulation model was developed for IGCC systems with alternative types of ASU and gas turbine integration. The model is applied to evaluate integration schemes involving nitrogen injection, air extraction, and combinations of both, as well as different ASU pressure levels. The optimal nitrogen injection only case in combination with an elevated pressure ASU had the highest efficiency and power output and approximately the lowest emissions per unit output of all cases considered, and thus is a recommended design option. The optimal combination of air extraction coupled with nitrogen injection had slightly worse efficiency, power output, and emissions than the optimal nitrogen injection only case. Air extraction alone typically produced lower efficiency, lower power output, and higher emissions than all other cases. The recommended nitrogen injection only case is estimated to provide annualized cost savings compared to a nonintegrated design. Process simulation modeling is shown to be a useful tool for evaluation and screening of technology options.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mittal, Sparsh; Zhang, Zhao
With each CMOS technology generation, leakage energy consumption has been dramatically increasing and hence, managing leakage power consumption of large last-level caches (LLCs) has become a critical issue in modern processor design. In this paper, we present EnCache, a novel software-based technique which uses dynamic profiling-based cache reconfiguration for saving cache leakage energy. EnCache uses a simple hardware component called profiling cache, which dynamically predicts energy efficiency of an application for 32 possible cache configurations. Using these estimates, system software reconfigures the cache to the most energy efficient configuration. EnCache uses dynamic cache reconfiguration and hence, it does not requiremore » offline profiling or tuning the parameter for each application. Furthermore, EnCache optimizes directly for the overall memory subsystem (LLC and main memory) energy efficiency instead of the LLC energy efficiency alone. The experiments performed with an x86-64 simulator and workloads from SPEC2006 suite confirm that EnCache provides larger energy saving than a conventional energy saving scheme. For single core and dual-core system configurations, the average savings in memory subsystem energy over a shared baseline configuration are 30.0% and 27.3%, respectively.« less
Preliminary supersonic flight test evaluation of performance seeking control
NASA Technical Reports Server (NTRS)
Orme, John S.; Gilyard, Glenn B.
1993-01-01
Digital flight and engine control, powerful onboard computers, and sophisticated controls techniques may improve aircraft performance by maximizing fuel efficiency, maximizing thrust, and extending engine life. An adaptive performance seeking control system for optimizing the quasi-steady state performance of an F-15 aircraft was developed and flight tested. This system has three optimization modes: minimum fuel, maximum thrust, and minimum fan turbine inlet temperature. Tests of the minimum fuel and fan turbine inlet temperature modes were performed at a constant thrust. Supersonic single-engine flight tests of the three modes were conducted using varied after burning power settings. At supersonic conditions, the performance seeking control law optimizes the integrated airframe, inlet, and engine. At subsonic conditions, only the engine is optimized. Supersonic flight tests showed improvements in thrust of 9 percent, increases in fuel savings of 8 percent, and reductions of up to 85 deg R in turbine temperatures for all three modes. The supersonic performance seeking control structure is described and preliminary results of supersonic performance seeking control tests are given. These findings have implications for improving performance of civilian and military aircraft.
NASA Astrophysics Data System (ADS)
Kumar, Ashwani; Vijay Babu, P.; Murty, V. V. S. N.
2017-06-01
Rapidly increasing electricity demands and capacity shortage of transmission and distribution facilities are the main driving forces for the growth of distributed generation (DG) integration in power grids. One of the reasons for choosing a DG is its ability to support voltage in a distribution system. Selection of effective DG characteristics and DG parameters is a significant concern of distribution system planners to obtain maximum potential benefits from the DG unit. The objective of the paper is to reduce the power losses and improve the voltage profile of the radial distribution system with optimal allocation of the multiple DG in the system. The main contribution in this paper is (i) combined power loss sensitivity (CPLS) based method for multiple DG locations, (ii) determination of optimal sizes for multiple DG units at unity and lagging power factor, (iii) impact of DG installed at optimal, that is, combined load power factor on the system performance, (iv) impact of load growth on optimal DG planning, (v) Impact of DG integration in distribution systems on voltage stability index, (vi) Economic and technical Impact of DG integration in the distribution systems. The load growth factor has been considered in the study which is essential for planning and expansion of the existing systems. The technical and economic aspects are investigated in terms of improvement in voltage profile, reduction in total power losses, cost of energy loss, cost of power obtained from DG, cost of power intake from the substation, and savings in cost of energy loss. The results are obtained on IEEE 69-bus radial distribution systems and also compared with other existing methods.
Experience with an integrated control and monitoring system at the El Segundo generating station
DOE Office of Scientific and Technical Information (OSTI.GOV)
Papilla, R.P.; McKinley, J.H.; Blanco, M.A.
1992-01-01
This paper describes the EPRI/Southern California Edison (SCE) El Segundo Integrated Control and Monitoring System (ICMS) project and relates key project experiences. The ICMS project is a cost-shared effort between EPRI and SCE designed to address the issues involved with integrating power plant diagnostic and condition monitoring with control. A digital distributed control system retrofit for SCE's El Segundo Units 3 and 4 provided the case study. although many utilities have retrofitted power plant units with distributed control systems (DCS's) and have applied diagnostics and monitoring programs to improve operations and performance, the approach taken in this project, that is,more » integrating the monitoring function with the control function, is profoundly new and unique. Over the life of the El Segundo ICMS, SCE expects to realize savings form life optimization, increased operating flexibility, improved heat rate, reduced NO{sub x} emissions, and lower maintenance costs. These savings are expected to be significant over the life of the system.« less
LANTR Engine Optimization for Lunar Missions
NASA Astrophysics Data System (ADS)
Bulman, M. J.; Poth, Greg; Borowski, Stan
2006-01-01
Propulsion requirements for sustainable Lunar missions are very demanding. The high Delta V for short transit times and/or reusable vehicles are best served with the High Isp of Nuclear Propulsion. High thrust is needed to reduce gravity losses during earth departure. The LOX-Augmented Nuclear Thermal Rocket (LANTR) is a concept whereby thrust from a nuclear thermal rocket can be doubled, or even quadrupled, by the injection and combustion of gaseous oxygen downstream of the throat. This has many advantages for the mission including a reduction in the size of the reactor(s) and propellant tank volume for a given payload delivered to Low Lunar Orbit. In this paper, we conduct mission studies to define the optimum basic (Unaugmented) engine thrust, Lox augmentation level and Lox loading for minimum initial mass in low earth orbit. 35% mass savings are seen for NTR powered LTVs with over twice the propellant Volume. The LANTR powered LTV has a similar mass savings with minimal volume penalties.
Energy configuration optimization of submerged propeller in oxidation ditch based on CFD
NASA Astrophysics Data System (ADS)
Wu, S. Y.; Zhou, D. Q.; Zheng, Y.
2012-11-01
The submerged propeller is presented as an important dynamic source in oxidation ditch. In order to guarantee the activated sludge not deposit, it is necessary to own adequate drive power. Otherwise, it will cause many problems such as the awful mixed flow and the great consuming of energy. At present, carrying on the installation optimization of submerged propeller in oxidation ditch mostly depends on experience. So it is necessary to use modern design method to optimize the installation position and number of submerged propeller, and to research submerged propeller flow field characteristics. The submerged propeller internal flow is simulated by using CFD software FLUENT6.3. Based on Navier-Stokes equations and standard k - ɛ turbulence model, the flow was simulated by using a SIMPLE algorithm. The results indicate that the submerged propeller installation position change could avoid the condition of back mixing, which caused by the strong drive. Besides, the problem of sludge deposit and the low velocity in the bend which caused by the drive power attenuation could be solved. By adjusting the submerged propeller number, the least power density that the mixing drive needed could be determined and saving energy purpose could be achieved. The study can provide theoretical guidance for optimize the submerged propeller installation position and determine submerged propeller number.
Optimized design and analysis of preclinical intervention studies in vivo
Laajala, Teemu D.; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero
2016-01-01
Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions. PMID:27480578
Optimized design and analysis of preclinical intervention studies in vivo.
Laajala, Teemu D; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero
2016-08-02
Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions.
Parameter Optimization and Operating Strategy of a TEG System for Railway Vehicles
NASA Astrophysics Data System (ADS)
Heghmanns, A.; Wilbrecht, S.; Beitelschmidt, M.; Geradts, K.
2016-03-01
A thermoelectric generator (TEG) system demonstrator for diesel electric locomotives with the objective of reducing the mechanical load on the thermoelectric modules (TEM) is developed and constructed to validate a one-dimensional thermo-fluid flow simulation model. The model is in good agreement with the measurements and basis for the optimization of the TEG's geometry by a genetic multi objective algorithm. The best solution has a maximum power output of approx. 2.7 kW and does not exceed the maximum back pressure of the diesel engine nor the maximum TEM hot side temperature. To maximize the reduction of the fuel consumption, an operating strategy regarding the system power output for the TEG system is developed. Finally, the potential consumption reduction in passenger and freight traffic operating modes is estimated under realistic driving conditions by means of a power train and lateral dynamics model. The fuel savings are between 0.5% and 0.7%, depending on the driving style.
Economic Analysis and Optimal Sizing for behind-the-meter Battery Storage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Di; Kintner-Meyer, Michael CW; Yang, Tao
This paper proposes methods to estimate the potential benefits and determine the optimal energy and power capacity for behind-the-meter BSS. In the proposed method, a linear programming is first formulated only using typical load profiles, energy/demand charge rates, and a set of battery parameters to determine the maximum saving in electric energy cost. The optimization formulation is then adapted to include battery cost as a function of its power and energy capacity in order to capture the trade-off between benefits and cost, and therefore to determine the most economic battery size. Using the proposed methods, economic analysis and optimal sizingmore » have been performed for a few commercial buildings and utility rate structures that are representative of those found in the various regions of the Continental United States. The key factors that affect the economic benefits and optimal size have been identified. The proposed methods and case study results cannot only help commercial and industrial customers or battery vendors to evaluate and size the storage system for behind-the-meter application, but can also assist utilities and policy makers to design electricity rate or subsidies to promote the development of energy storage.« less
Optimization-based sale transactions and hydrothermal scheduling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prasannan, B.; Luh, P.B.; Yan, H.
1995-12-31
Selling and purchasing power are important activities for utilities because of potential savings. When a selling utility presents an offer including prices, power levels and durations, a purchasing utility selects power levels and durations within the offered range subject to relevant constraints. The decisionmaking process is complicated because transactions are coupled with system demand and reserve, therefore decisions have to be made in conjunction with the commitment and dispatching of units. Furthermore, transaction decisions have to be made in almost real time in view of the competitiveness of the power market caused by deregulation. In this paper, transactions are analyzedmore » from a selling utility`s viewpoint for a system consisting of thermal, hydro and pumped-storage units. To effectively solve the problem, linear sale revenues are approximated by nonlinear functions, and non-profitable options are identified and eliminated from consideration. The multipliers are then updated at the high level by using a modified subgradient method to obtain near optimal solutions quickly. Testing results show that the algorithm produces good sale offers efficiently.« less
Optimization-based sale transactions and hydrothermal scheduling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prasannan, B.; Luh, P.B.; Yan, H.
1996-05-01
Selling and purchasing power are important activities for utilities because of potential savings. When a selling utility presents an offer including prices, power levels and durations, a purchasing utility selects power levels and durations within the offered range subject to relevant constraints. The decisionmaking process is complicated because transactions are coupled with system demand and reserve, therefore decisions have to be made in conjunction with the commitment and dispatching of units. Furthermore, transaction decisions have to be made in almost real time in view of the competitiveness of the power market caused by deregulation. In this paper, transactions are analyzedmore » from a selling utility`s viewpoint for a system consisting of thermal, hydro and pumped-storage units. To effectively solve the problem, linear sale revenues are approximated by nonlinear functions, and non-profitable options are identified and eliminated from consideration. The multipliers are then updated at the high level by using a modified subgradient method to obtain near optimal solutions quickly. Testing results show that the algorithm produces good sale offers efficiently.« less
NASA Astrophysics Data System (ADS)
Dang, Jie; Chen, Hao
2016-12-01
The methodology and procedures are discussed on designing merchant ships to achieve fully-integrated and optimized hull-propulsion systems by using asymmetric aftbodies. Computational fluid dynamics (CFD) has been used to evaluate the powering performance through massive calculations with automatic deformation algorisms for the hull forms and the propeller blades. Comparative model tests of the designs to the optimized symmetric hull forms have been carried out to verify the efficiency gain. More than 6% improvement on the propulsive efficiency of an oil tanker has been measured during the model tests. Dedicated sea-trials show good agreement with the predicted performance from the test results.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false How may a savings association exercise its... Regulations Applicable to All Savings Associations § 559.13 How may a savings association exercise its salvage... section, a savings association (“you”) may exercise your salvage power to make a contribution or a loan...
Code of Federal Regulations, 2014 CFR
2014-01-01
... 12 Banks and Banking 6 2014-01-01 2012-01-01 true How may a savings association exercise its... Regulations Applicable to All Savings Associations § 559.13 How may a savings association exercise its salvage... section, a savings association (“you”) may exercise your salvage power to make a contribution or a loan...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 12 Banks and Banking 6 2012-01-01 2012-01-01 false How may a savings association exercise its... Regulations Applicable to All Savings Associations § 559.13 How may a savings association exercise its salvage... section, a savings association (“you”) may exercise your salvage power to make a contribution or a loan...
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false How may a savings association exercise its... Regulations Applicable to All Savings Associations § 559.13 How may a savings association exercise its salvage... section, a savings association (“you”) may exercise your salvage power to make a contribution or a loan...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhou, Bin; Yang, Rui; Li, Canbing
Here, time-of-use (TOU) rates and stepwise power tariff (SPT) are important economic levers to motivate residents to shift their electricity usage in response to electricity price. In this paper, a new multiobjective optimal tariff-making model of time-of-use and stepwise power tariff (TOUSPT) is proposed, which combines the complementary characteristics of two power tariffs, for residential energy conservation and peak load shaving. In the proposed approach, the residential demand response with price elasticity in regulated power market is considered to determine the optimum peak-valley TOU tariffs for each stepwise electricity partition. Furthermore, a practical case study is implemented to test themore » effectiveness of the proposed TOUSPT, and the results demonstrate that TOUSPT can achieve efficient end-use energy saving and also shift load from peak to off-peak periods.« less
Zhou, Bin; Yang, Rui; Li, Canbing; ...
2017-07-04
Here, time-of-use (TOU) rates and stepwise power tariff (SPT) are important economic levers to motivate residents to shift their electricity usage in response to electricity price. In this paper, a new multiobjective optimal tariff-making model of time-of-use and stepwise power tariff (TOUSPT) is proposed, which combines the complementary characteristics of two power tariffs, for residential energy conservation and peak load shaving. In the proposed approach, the residential demand response with price elasticity in regulated power market is considered to determine the optimum peak-valley TOU tariffs for each stepwise electricity partition. Furthermore, a practical case study is implemented to test themore » effectiveness of the proposed TOUSPT, and the results demonstrate that TOUSPT can achieve efficient end-use energy saving and also shift load from peak to off-peak periods.« less
First-Order Frameworks for Managing Models in Engineering Optimization
NASA Technical Reports Server (NTRS)
Alexandrov, Natlia M.; Lewis, Robert Michael
2000-01-01
Approximation/model management optimization (AMMO) is a rigorous methodology for attaining solutions of high-fidelity optimization problems with minimal expense in high- fidelity function and derivative evaluation. First-order AMMO frameworks allow for a wide variety of models and underlying optimization algorithms. Recent demonstrations with aerodynamic optimization achieved three-fold savings in terms of high- fidelity function and derivative evaluation in the case of variable-resolution models and five-fold savings in the case of variable-fidelity physics models. The savings are problem dependent but certain trends are beginning to emerge. We give an overview of the first-order frameworks, current computational results, and an idea of the scope of the first-order framework applicability.
A highly linear fully integrated powerline filter for biopotential acquisition systems.
Alzaher, Hussain A; Tasadduq, Noman; Mahnashi, Yaqub
2013-10-01
Powerline interference is one of the most dominant problems in detection and processing of biopotential signals. This work presents a new fully integrated notch filter exhibiting high linearity and low power consumption. High filter linearity is preserved utilizing active-RC approach while IC implementation is achieved through replacing passive resistors by R-2R ladders achieving area saving of approximately 120 times. The filter design is optimized for low power operation using an efficient circuit topology and an ultra-low power operational amplifier. Fully differential implementation of the proposed filter shows notch depth of 43 dB (78 dB for 4th-order) with THD of better than -70 dB while consuming about 150 nW from 1.5 V supply.
NASA Astrophysics Data System (ADS)
Ataei, Milad; Robert, Christian; Boegli, Alexis; Farine, Pierre-André
2014-11-01
This paper describes a design procedure for an efficient body thermal energy harvesting integrated power converter. This procedure is based on loss examination for a selfpowered medical device. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. It is found that it is possible to optimize converter's working frequency with proper design of its pulse generator circuit. At selected frequency, it has been demonstrated that wide area voltage doubler can be eliminated at the expense of wider switches. With this method, more than 60% efficiency is achieved in simulation for just 20mV transducer output voltage and 30% of entire chip area is saved.
NASA Astrophysics Data System (ADS)
Du, Zenghui
2018-04-01
At present, the flue gas waste heat utilization projects of coal-fired boilers are often limited by low temperature corrosion problems and conventional PID control. The flue gas temperature cannot be reduced to the best efficiency temperature of wet desulphurization, resulting in the failure of heat recovery to be the maximum. Therefore, this paper analyzes, researches and solves the remaining problems of the cold end system of thermal power station, so as to provide solutions and theoretical support for energy saving and emission reduction and upgrading and the improvement of the comprehensive efficiency of the units.
Energy Efficient Waste Heat Recovery from an Engine Exhaust System
2016-12-01
targets. Since solar panels and wind turbines will not work for ships; the energy savings must come from making the existing power generation...achieve an approximate solution to the problem . The research for this thesis involved design by analysis of heat exchange in a gas turbine exhaust...effectiveness of a new style of heat exchanger for waste heat recovery. The new design sought to optimize heat recovery from a gas turbine engine exhaust as
NASA Astrophysics Data System (ADS)
Boivin, David; Bigot-Astruc, Marianne; De Montmorillon, Louis-Anne; Provost, Lionel; Sillard, Pierre; Bergonzo, Aurélien
2009-02-01
After many years of expectations, Fiber To The Home (FTTH) has finally become a reality with a wide number of projects already running worldwide and growing. Optical fiber is inevitably taking more and more importance in our environment, but for many good reasons, the space we are truly willing or able to allocate to it remains limited. These installation constrainsts have turned into additional requirements that need to be addressed for both active and passive components. If exceptional bending performances obtained without degrading backward compatibilities is a pre-requisite to deployment success,1 other parameters also need to be carefully taken into account when designing the ideal candidate for use in confined environments. Among them, one can cite the bend loss homogeneity over length and bending directions, the resistance to high optical power under bending and the tolerance to modal noise. In this paper, we present the design and performances of a bend insensitive fiber optimized towards more space savings and miniaturization of components. In addition to exceptional bending performances - lower than 0.1 dB/turn over a 5 mm bending radius -, its design guarantees impressive homogeneity levels and enhanced safety margins for high power applications while being still resistant to modal noise. Successfull cleave- and splice-ability results are finally presented, making this fiber ideally suited for use in components, pigtails and patchcords.
An Arrival and Departure Time Predictor for Scheduling Communication in Opportunistic IoT
Pozza, Riccardo; Georgoulas, Stylianos; Moessner, Klaus; Nati, Michele; Gluhak, Alexander; Krco, Srdjan
2016-01-01
In this article, an Arrival and Departure Time Predictor (ADTP) for scheduling communication in opportunistic Internet of Things (IoT) is presented. The proposed algorithm learns about temporal patterns of encounters between IoT devices and predicts future arrival and departure times, therefore future contact durations. By relying on such predictions, a neighbour discovery scheduler is proposed, capable of jointly optimizing discovery latency and power consumption in order to maximize communication time when contacts are expected with high probability and, at the same time, saving power when contacts are expected with low probability. A comprehensive performance evaluation with different sets of synthetic and real world traces shows that ADTP performs favourably with respect to previous state of the art. This prediction framework opens opportunities for transmission planners and schedulers optimizing not only neighbour discovery, but the entire communication process. PMID:27827909
An Arrival and Departure Time Predictor for Scheduling Communication in Opportunistic IoT.
Pozza, Riccardo; Georgoulas, Stylianos; Moessner, Klaus; Nati, Michele; Gluhak, Alexander; Krco, Srdjan
2016-11-04
In this article, an Arrival and Departure Time Predictor (ADTP) for scheduling communication in opportunistic Internet of Things (IoT) is presented. The proposed algorithm learns about temporal patterns of encounters between IoT devices and predicts future arrival and departure times, therefore future contact durations. By relying on such predictions, a neighbour discovery scheduler is proposed, capable of jointly optimizing discovery latency and power consumption in order to maximize communication time when contacts are expected with high probability and, at the same time, saving power when contacts are expected with low probability. A comprehensive performance evaluation with different sets of synthetic and real world traces shows that ADTP performs favourably with respect to previous state of the art. This prediction framework opens opportunities for transmission planners and schedulers optimizing not only neighbour discovery, but the entire communication process.
Phase 1 of the near term hybrid passenger vehicle development program
NASA Technical Reports Server (NTRS)
Montalenti, P.; Piccolo, R.
1979-01-01
In order to meet project requirements and be competitive in the 1985 market, the proposed six-passenger vehicle incorporates a high power type Ni-Zn battery, which by making electric-only traction possible, permits the achievement of an optimized control strategy based on electric-only traction to a set battery depth of discharge, followed by hybrid operation with thermal primary energy. This results in a highly efficient hybrid propulsion subsystem. Technical solutions are available to contain energy waste by reducing vehicle weight, rolling resistance, and drag coefficient. Reproaching new 1985 full size vehicles of the conventional type with hybrids of the proposed type would result in a U.S. average gasoline saving per vehicle of 1,261 liters/year and an average energy saving per vehicle of 27,133 MJ/year.
Nuclear and Solar Energy: Implications for Homeland Security
2008-12-01
of New Nuclear Plants?" Nuclear Engineering International, March 31, 2004, 14. 10 Gwyneth Cravens, Power to Save the World: The Truth about...Pueblo West, CO: Vales Lake Pub, 2004), 98. 12 Cravens, Power to Save the World: The Truth about Nuclear Energy, 249. 13 Jerry Taylor, "Powering...Cravens, Power to Save the World: The Truth about Nuclear Energy, 152. 30 William Langewiesche, The Atomic Bazaar: Dispatches from the Underground World
[Application of microwave technology in extraction process of Guizhi Fuling capsule].
Wang, Zheng-kuan; Zhou, Mao; Liu, Yuan; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei
2015-06-01
In this paper, optimization of the conditions of microwave technique in extraction process of Guizhi Fuling capsule in the condition of a pilot scale was carried out. First of all, through the single factor experiment investigation of various factors, the overall impact tendency and range of each factor were determined. Secondly, L9 (3(4)) orthogonal test optimization was used, and the contents of gallic acid in liquid, paeoniflorin, benzoic acid, cinnamic acid, benzoyl paeoniflorin, amygdalin of the liquid medicine were detected. The extraction rate and comprehensive evaluation were calculated with the extraction effect, as the judgment basis. Theoptimum extraction process of Guizhi Fuling capsule by microwave technology was as follows: the ratio of liquid to solid was 6: 1 added to drinking water, the microwave power was 6 kW, extraction time was 20 min for 3 times. The process of the three batch of amplification through verification, the results are stable, and compared with conventional water extraction has the advantages of energy saving, time saving, high efficiency advantages. The above results show the optimum extracting technology of high efficiency, stable and feasible.
Reducing CO2 emissions and energy consumption of heat-integrated distillation systems.
Gadalla, Mamdouh A; Olujic, Zarko; Jansens, Peter J; Jobson, Megan; Smith, Robin
2005-09-01
Distillation systems are energy and power intensive processes and contribute significantly to the greenhouse gases emissions (e.g. carbon dioxide). Reducing CO2 emissions is an absolute necessity and expensive challenge to the chemical process industries in orderto meetthe environmental targets as agreed in the Kyoto Protocol. A simple model for the calculation of CO2 emissions from heat-integrated distillation systems is introduced, considering typical process industry utility devices such as boilers, furnaces, and turbines. Furnaces and turbines consume large quantities of fuels to provide electricity and process heats. As a result, they produce considerable amounts of CO2 gas to the atmosphere. Boilers are necessary to supply steam for heating purposes; besides, they are also significant emissions contributors. The model is used in an optimization-based approach to optimize the process conditions of an existing crude oil atmospheric tower in order to reduce its CO2 emissions and energy demands. It is also applied to generate design options to reduce the emissions from a novel internally heat-integrated distillation column (HIDiC). A gas turbine can be integrated with these distillation systems for larger emissions reduction and further energy savings. Results show that existing crude oil installations can save up to 21% in energy and 22% in emissions, when the process conditions are optimized. Additionally, by integrating a gas turbine, the total emissions can be reduced further by 48%. Internal heat-integrated columns can be a good alternative to conventional heat pump and other energy intensive close boiling mixtures separations. Energy savings can reach up to 100% with respect to reboiler heat requirements. Emissions of these configurations are cut down by up to 83%, compared to conventional units, and by 36%, with respect to heat pump alternatives. Importantly, cost savings and more profit are gained in parallel to emissions minimization.
Optimization of Crew Shielding Requirement in Reactor-Powered Lunar Surface Missions
NASA Technical Reports Server (NTRS)
Barghouty, Abdulnasser F.
2007-01-01
On the surface of the moon -and not only during heightened solar activities- the radiation environment As such that crew protection will be required for missions lasting in excess of six months. This study focuses on estimating the optimized crew shielding requirement for lunar surface missions with a nuclear option. Simple, transport-simulation based dose-depth relations of the three (galactic, solar, and fission) radiation sources am employed in a 1-dimensional optimization scheme. The scheme is developed to estimate the total required mass of lunar-regolith separating reactor from crew. The scheme was applied to both solar maximum and minimum conditions. It is shown that savings of up to 30% in regolith mass can be realized. It is argued, however, that inherent variation and uncertainty -mainly in lunar regolith attenuation properties in addition to the radiation quality factor- can easily defeat this and similar optimization schemes.
Optimization of Crew Shielding Requirement in Reactor-Powered Lunar Surface Missions
NASA Technical Reports Server (NTRS)
Barghouty, A. F.
2007-01-01
On the surface of the moon and not only during heightened solar activities the radiation environment is such that crew protection will be required for missions lasting in excess of six months. This study focuses on estimating the optimized crew shielding requirement for lunar surface missions with a nuclear option. Simple, transport-simulation based dose-depth relations of the three radiation sources (galactic, solar, and fission) are employed in a one-dimensional optimization scheme. The scheme is developed to estimate the total required mass of lunar regolith separating reactor from crew. The scheme was applied to both solar maximum and minimum conditions. It is shown that savings of up to 30% in regolith mass can be realized. It is argued, however, that inherent variation and uncertainty mainly in lunar regolith attenuation properties in addition to the radiation quality factor can easily defeat this and similar optimization schemes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hasan, Iftekhar; Husain, Tausif; Sozer, Yilmaz
This paper proposes an analytical machine design tool using magnetic equivalent circuit (MEC)-based particle swarm optimization (PSO) for a double-sided, flux-concentrating transverse flux machine (TFM). The magnetic equivalent circuit method is applied to analytically establish the relationship between the design objective and the input variables of prospective TFM designs. This is computationally less intensive and more time efficient than finite element solvers. A PSO algorithm is then used to design a machine with the highest torque density within the specified power range along with some geometric design constraints. The stator pole length, magnet length, and rotor thickness are the variablesmore » that define the optimization search space. Finite element analysis (FEA) was carried out to verify the performance of the MEC-PSO optimized machine. The proposed analytical design tool helps save computation time by at least 50% when compared to commercial FEA-based optimization programs, with results found to be in agreement with less than 5% error.« less
Power Saving Control for Battery-Powered Portable WLAN APs
NASA Astrophysics Data System (ADS)
Ogawa, Masakatsu; Hiraguri, Takefumi
This paper proposes a power saving control function for battery-powered portable wireless LAN (WLAN) access points (APs) to extend the battery life. The IEEE802.11 standard does not support power saving control for APs. To enable a sleep state for an AP, the AP forces the stations (STAs) to refrain from transmitting frames using the network allocation vector (NAV) while the AP is sleeping. Thus the sleep state for the AP can be employed without causing frame loss at the STAs. Numerical analysis and computer simulation reveal that the newly proposed control technique conserves power compared to the conventional control.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 12 Banks and Banking 1 2013-01-01 2013-01-01 false How may a Federal savings association exercise... ORGANIZATIONS § 159.13 How may a Federal savings association exercise its salvage power in connection with its... association (“you”) may exercise your salvage power to make a contribution or a loan (including a guarantee of...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 12 Banks and Banking 5 2012-01-01 2012-01-01 false How may a State savings association exercise... How may a State savings association exercise its salvage power in connection with a service...”) may exercise your salvage power to make a contribution or a loan (including a guarantee of a loan made...
White Nail Radio Transmitter: Billion Dollar Savings through Energy Efficiency
2011-05-10
increase efficiency and reduce overall energy consumption ashore by 50 percent CNO, Navy Energy Vision, P 10 White Nail Vision Your Cell Phone Cell...Estimated Total Number of transmitters 3,000,000 Estimated total power saved Watt 1,250,000,000 Cell Phone Transmitter Efficiency 1.25 Gigawatts saved...Greenhouse Gas Power 4 1 Energy Navy Use 7.3 Billion kWh White Nail Cell Phone Savings 11 Billion kWh One and a half times!!! Saves the output of four of
NASA Astrophysics Data System (ADS)
Sinaga, R. H. M.; Manik, Y.
2018-03-01
Sibayak Geothermal Power Plant (SGPP) is one of the plants being developed by Pertamina Geothermal Energy (PGE) at the upstream phase. At the downstream phase, State - owned Electricity Company (PLN) through PT. Dizamatra Powerindo is the developer. The gross capacity of the power plant is 13.3 MW, consisting 1 unit of Monoblock (2 MW) developed by PGE and 2 units (2×5.65 MW) operated through Energy Sales Contract by PLN. During the development phase of a geothermal power plant, there is a chance to reduce the utility power in order to increase the overall plant efficiency. Reducing the utility power can be attempted by utilizing the wet bulb temperature fluctuation. In this study, a modeling process is developed by using Engineering Equation Solver (EES) software version 9.430. The possibility of energy saving is indicated by condenser pressure changes as a result of wet bulb temperature fluctuation. The result of this study indicates that the change of condenser pressure is about 50.8% on the constant liquid/gas (L/G) condition of the wet bulb temperature of 15°C to 25°C. Further result indicates that in this power plant, Cooling Tower Fan (CTF) is the facility that has the greatest utility load, followed by Hot Well Pump (HWP). The saving of the greatest utility load is applied trough Variable Frequency Drive (VFD) instrumentation. The result of this modeling has been validated by actual operations data (log sheet). The developed model has also been reviewed trough Specific Steam Consumption (SSC), resulting that constant L/G condition allows the optimum condition on of the wet bulb temperature of 15°C to 25°C.
Optimal integration of daylighting and electric lighting systems using non-imaging optics
NASA Astrophysics Data System (ADS)
Scartezzini, J.-L.; Linhart, F.; Kaegi-Kolisnychenko, E.
2007-09-01
Electric lighting is responsible for a significant fraction of electricity consumption within non-residential buildings. Making daylight more available in office and commercial buildings can lead as a consequence to important electricity savings, as well as to the improvement of occupants' visual performance and wellbeing. Over the last decades, daylighting technologies have been developed for that purpose, some of them having proven to be highly efficient such as anidolic daylighting systems. Based on non-imaging optics these optical devices were designed to achieve an efficient collection and redistribution of daylight within deep office rooms. However in order to benefit from the substantial daylight provision obtained through these systems and convert it into effective electricity savings, novel electric lighting strategies are required. An optimal integration of high efficacy light sources and efficient luminaries based on non-imaging optics with anidolic daylighting systems can lead to such novel strategies. Starting from the experience gained through the development of an Anidolic Integrated Ceiling (AIC), this paper presents an optimal integrated daylighting and electric lighting system. Computer simulations based on ray-tracing techniques were used to achieve the integration of 36W fluorescent tubes and non-imaging reflectors with an advanced daylighting system. Lighting power densities lower than 4 W/m2 can be achieved in this way within the corresponding office room. On-site monitoring of an integrated daylighting and electric lighting system carried out on a solar experimental building confirmed the energy and visual performance of such a system: it showed that low lighting power densities can be achieved by combining an anidolic daylighting system with very efficient electric light sources and luminaries.
Compressed Air System Optimization: Case Study Food Industry in Indonesia
NASA Astrophysics Data System (ADS)
Widayati, Endang; Nuzahar, Hasril
2016-01-01
Compressors and compressed air systems was one of the most important utilities in industries or factories. Approximately 10% of the cost of electricity in the industry was used to produce compressed air. Therefore the potential for energy savings in the compressors and compressed air systems had a big challenge. This field was conducted especially in Indonesia food industry or factory. Compressed air system optimization was a technique approach to determine the optimal conditions for the operation of compressors and compressed air systems that included evaluation of the energy needs, supply adjustment, eliminating or reconfiguring the use and operation of inefficient, changing and complementing some equipment and improving operating efficiencies. This technique gave the significant impact for energy saving and costs. The potential savings based on this study through measurement and optimization e.g. system that lowers the pressure of 7.5 barg to 6.8 barg would reduce energy consumption and running costs approximately 4.2%, switch off the compressor GA110 and GA75 was obtained annual savings of USD 52,947 ≈ 455 714 kWh, running GA75 light load or unloaded then obtained annual savings of USD 31,841≈ 270,685 kWh, install new compressor 2x132 kW and 1x 132 kW VSD obtained annual savings of USD 108,325≈ 928,500 kWh. Furthermore it was needed to conduct study of technical aspect of energy saving potential (Investment Grade Audit) and performed Cost Benefit Analysis. This study was one of best practice solutions how to save energy and improve energy performance in compressors and compressed air system.
Oilwell Power Controller (OPC)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1993-08-01
The Oil Well Power Controller (OPC) prototype units is nearing completion. This device is an oilwell beam pump controller and data logger. Applications for this device have been for an electrical power saving device, pump off control, parafffin detection, demand power load control, chemical treatment data, dynamometer and pump efficiency data. Preliminary results appear vary promising. A total of ten OPC rod pump controllers were assembled and installed on oilwells in several areas of Central and Western United States. Data was analyzed on these wells and forwarded to the participating oil companies. Cost savings on each individual oil well participatingmore » in the OPC testing vary considerably, savings on some situations have been outstanding. In situations where the pump efficiency was determined to be low, the cost savings have been considerable. Cost savings due to preventive maintenance are also present, but are difficult to pin point an exact dollar amount at the present time. A break out of actual cost data obtained on some of the oilwells controlled and monitored with the oilwell power controller.« less
A Novel Sensor Platform Matching the Improved Version of IPMVP Option C for Measuring Energy Savings
Tseng, Yen-Chieh; Lee, Da-Sheng; Lin, Cheng-Fang; Chang, Ching-Yuan
2013-01-01
It is easy to measure energy consumption with a power meter. However, energy savings cannot be directly computed by the powers measured using existing power meter technologies, since the power consumption only reflects parts of the real energy flows. The International Performance Measurement and Verification Protocol (IPMVP) was proposed by the Efficiency Valuation Organization (EVO) to quantify energy savings using four different methodologies of A, B, C and D. Although energy savings can be estimated following the IPMVP, there are limitations on its practical implementation. Moreover, the data processing methods of the four IPMVP alternatives use multiple sensors (thermometer, hygrometer, Occupant information) and power meter readings to simulate all facilities, in order to determine an energy usage benchmark and the energy savings. This study proposes a simple sensor platform to measure energy savings. Using usually the Electronic Product Code (EPC) global standard, an architecture framework for an information system is constructed that integrates sensors data, power meter readings and occupancy conditions. The proposed sensor platform is used to monitor a building with a newly built vertical garden system (VGS). A VGS shields solar radiation and saves on energy that would be expended on air-conditioning. With this platform, the amount of energy saved in the whole facility is measured and reported in real-time. The data are compared with those obtained from detailed measurement and verification (M&V) processes. The discrepancy is less than 1.565%. Using measurements from the proposed sensor platform, the energy savings for the entire facility are quantified, with a resolution of ±1.2%. The VGS gives an 8.483% daily electricity saving for the building. Thus, the results show that the simple sensor platform proposed by this study is more widely applicable than the four complicated IPMVP alternatives and the VGS is an effective tool in reducing the carbon footprint of a building. PMID:23698273
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Hong; Wang, Shaobu; Fan, Rui
This report summaries the work performed under the LDRD project on the preliminary study on knowledge automation, where specific focus has been made on the investigation of the impact of uncertainties of human decision making onto the optimization of the process operation. At first the statistics on signals from the Brain-Computing Interface (BCI) is analyzed so as to obtain the uncertainties characterization of human operators during the decision making phase using the electroencephalogram (EEG) signals. This is then followed by the discussions of an architecture that reveals the equivalence between optimization and closed loop feedback control design, where it hasmore » been shown that all the optimization problems can be transferred into the control design problem for closed loop systems. This has led to a “closed loop” framework, where the structure of the decision making is shown to be subjected to both process disturbances and controller’s uncertainties. The latter can well represent the uncertainties or randomness occurred during human decision making phase. As a result, a stochastic optimization problem has been formulated and a novel solution has been proposed using probability density function (PDF) shaping for both the cost function and the constraints using stochastic distribution control concept. A sufficient condition has been derived that guarantees the convergence of the optimal solution and discussions have been made for both the total probabilistic solution and chanced constrained optimization which have been well-studied in optimal power flows (OPF) area. A simple case study has been carried out for the economic dispatch of powers for a grid system when there are distributed energy resources (DERs) in the system, and encouraging results have been obtained showing that a significant savings on the generation cost can be expected.« less
Intensification of ion exchange desorption of thiamine diphosphate by low-powered ultrasound.
Pinchukova, Natalia A; Voloshko, Alexander Y; Merko, Maria A; Bondarenko, Yana A; Chebanov, Valentin A
2018-03-01
The process of ultrasound-assisted ion-exchange desorption of cocarboxylase (thiamine diphosphate (TDP)) from a strong acidic cation resin was studied. Kinetics studies revealed that ultrasound accelerates TDP desorption by 3 times. The optimal desorption parameters, viz. US power input, sonication time, eluent/resin ratio and the eluent (ammonium acetate buffer) concentration were established which were 15mW/cm 3 , 20min, 1:1 and 1M, respectively. The resin stability studies showed that the optimal ultrasonic power was less by the order than the resin degradation threshold which ensures durable and efficient resin exploitation during production. The resin sorption capacity remained unchanged even after 20 cycles of TDP sorption, ultrasonic desorption and resin regeneration. The recovery ratio of TDP was shown to increase non-linearly with decreasing the resin saturation factor, which can be attributed to diffusion limitations occurring during desorption. The optimal resin loading corresponding to more than 90 per cent of TDP recovery was found to be at the level of 10 per cent of the maximal sorption capacity. The study revealed 4-5-fold increase in concentrations of the recovered solutions, which together with process times shortening should result in considerable energy saving in downstream operations on production scale. Copyright © 2017 Elsevier B.V. All rights reserved.
Analytical Model-Based Design Optimization of a Transverse Flux Machine
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hasan, Iftekhar; Husain, Tausif; Sozer, Yilmaz
This paper proposes an analytical machine design tool using magnetic equivalent circuit (MEC)-based particle swarm optimization (PSO) for a double-sided, flux-concentrating transverse flux machine (TFM). The magnetic equivalent circuit method is applied to analytically establish the relationship between the design objective and the input variables of prospective TFM designs. This is computationally less intensive and more time efficient than finite element solvers. A PSO algorithm is then used to design a machine with the highest torque density within the specified power range along with some geometric design constraints. The stator pole length, magnet length, and rotor thickness are the variablesmore » that define the optimization search space. Finite element analysis (FEA) was carried out to verify the performance of the MEC-PSO optimized machine. The proposed analytical design tool helps save computation time by at least 50% when compared to commercial FEA-based optimization programs, with results found to be in agreement with less than 5% error.« less
NASA Astrophysics Data System (ADS)
Mullen, Christopher
Implementation of energy harvesting technology can provide a sustainable, remote power source for soldiers by reducing the battery weight and allowing them to stay in the field for longer periods of time. Among multiple energy conversion principles, electromagnetic induction can scavenge energy from wasted kinematic and vibration energy found from human motion. Hip displacement during human gait acts as a base excitation for an energy harvesting backpack system. The placement of a permanent magnet in this vibration environment results in relative motion of the magnet to the coil of copper wire, which induces an electric current. This current can be saved to a battery or capacitor bank installed on the backpack to be used to power electronic devices. The purpose of this research is to construct a reliable simulation model for an electromagnetic vibration energy harvester and use it for a multi-variable optimization algorithm to identify an optimal coil and magnet layout for highest power output. Key components of the coupled equations of motion such as the magnetic flux density and coil inductance are obtained using ANSYS multi-physics software or by measuring them. These components are fed into a harvester simulation model (e.g. coupled field equations of motion for the backpack harvester) that generates the electrical power output. The developed simulation model is verified with multiple case studies including an experimental test. Then the optimal design parameters in the simulation model (e.g., magnet layout, coil width, outer coil diameter, external load resistance) are identified for maximum power. Results from this study will pave the way for a more efficient energy harvesting backpack while providing better insight into the efficiency of magnet and coil layout for electromagnetic applications.
Experimental verification and optimization of a linear electromagnetic energy harvesting device
NASA Astrophysics Data System (ADS)
Mullen, Christopher; Lee, Soobum
2017-04-01
Implementation of energy harvesting technology can provide a sustainable, remote power source for soldiers by reducing the battery weight and allowing them to stay in the field for longer periods of time. Among multiple energy conversion principles, electromagnetic induction can scavenge energy from wasted kinematic and vibration energy found from human motion. Hip displacement during human gait acts as a base excitation for an energy harvesting backpack system. The placement of a permanent magnet in this vibration environment results in relative motion of the magnet to the coil of copper wire, which induces an electric current. This current can be saved to a battery or capacitor bank installed on the backpack to be used to power electronic devices. The purpose of this research is to construct a reliable simulation model for an electromagnetic vibration energy harvester and use it for a multi-variable optimization algorithm to identify an optimal coil and magnet layout for highest power output. Key components of the coupled equations of motion such as the magnetic flux density and coil inductance are obtained using ANSYS multi-physics software or by measuring them. These components are fed into a harvester simulation model (e.g. coupled field equations of motion for the backpack harvester) that generates the electrical power output. The developed simulation model is verified with a case study including an experimental test. Then the optimal design parameters in the simulation model (e.g., magnet layout, coil width, outer coil diameter, external load resistance) are identified for maximum power. Results from this study will pave the way for a more efficient energy harvesting backpack while providing better insight into the efficiency of magnet and coil layout for electromagnetic applications.
A Summary of Research on Energy Saving and Emission Reduction of Transportation
NASA Astrophysics Data System (ADS)
Cheng, Dongxiang; Wu, Lufen
2017-12-01
Road transport is an important part of transportation, and road in the field of energy-saving emission reduction is a very important industry. According to the existing problems of road energy saving and emission reduction, this paper elaborates the domestic and international research on energy saving and emission reduction from three aspects: road network optimization, pavement material and pavement maintenance. Road network optimization may be overlooked, and the research content is still relatively preliminary; pavement materials mainly from the asphalt pavement temperature mixed asphalt technology research; pavement maintenance technology development is relatively comprehensive.
Distributed Channel Allocation and Time Slot Optimization for Green Internet of Things.
Ding, Kaiqi; Zhao, Haitao; Hu, Xiping; Wei, Jibo
2017-10-28
In sustainable smart cities, power saving is a severe challenge in the energy-constrained Internet of Things (IoT). Efficient utilization of limited multiple non-overlap channels and time resources is a promising solution to reduce the network interference and save energy consumption. In this paper, we propose a joint channel allocation and time slot optimization solution for IoT. First, we propose a channel ranking algorithm which enables each node to rank its available channels based on the channel properties. Then, we propose a distributed channel allocation algorithm so that each node can choose a proper channel based on the channel ranking and its own residual energy. Finally, the sleeping duration and spectrum sensing duration are jointly optimized to maximize the normalized throughput and satisfy energy consumption constraints simultaneously. Different from the former approaches, our proposed solution requires no central coordination or any global information that each node can operate based on its own local information in a total distributed manner. Also, theoretical analysis and extensive simulations have validated that when applying our solution in the network of IoT: (i) each node can be allocated to a proper channel based on the residual energy to balance the lifetime; (ii) the network can rapidly converge to a collision-free transmission through each node's learning ability in the process of the distributed channel allocation; and (iii) the network throughput is further improved via the dynamic time slot optimization.
Sub-threshold standard cell library design for ultra-low power biomedical applications.
Li, Ming-Zhong; Ieong, Chio-In; Law, Man-Kay; Mak, Pui-In; Vai, Mang-I; Martins, Rui P
2013-01-01
Portable/Implantable biomedical applications usually exhibit stringent power budgets for prolonging battery life time, but loose operating frequency requirements due to small bio-signal bandwidths, typically below a few kHz. The use of sub-threshold digital circuits is ideal in such scenario to achieve optimized power/speed tradeoffs. This paper discusses the design of a sub-threshold standard cell library using a standard 0.18-µm CMOS technology. A complete library of 56 standard cells is designed and the methodology is ensured through schematic design, transistor width scaling and layout design, as well as timing, power and functionality characterization. Performance comparison between our sub-threshold standard cell library and a commercial standard cell library using a 5-stage ring oscillator and an ECG designated FIR filter is performed. Simulation results show that our library achieves a total power saving of 95.62% and a leakage power reduction of 97.54% when compared with the same design implemented by the commercial standard cell library (SCL).
Vacuum Pump System Optimization Saves Energy at a Dairy Farm
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
In 1998, S&S Dairy optimized the vacuum pumping system at their dairy farm in Modesto, California. In an effort to reduce energy costs, S&S Dairy evaluated their vacuum pumping system to determine if efficiency gains and energy savings were possible.
NASA Astrophysics Data System (ADS)
Alabdulkarem, Abdullah
Liquefied natural gas (LNG) plants are energy intensive. As a result, the power plants operating these LNG plants emit high amounts of CO2 . To mitigate global warming that is caused by the increase in atmospheric CO2, CO2 capture and sequestration (CCS) using amine absorption is proposed. However, the major challenge of implementing this CCS system is the associated power requirement, increasing power consumption by about 15--25%. Therefore, the main scope of this work is to tackle this challenge by minimizing CCS power consumption as well as that of the entire LNG plant though system integration and rigorous optimization. The power consumption of the LNG plant was reduced through improving the process of liquefaction itself. In this work, a genetic algorithm (GA) was used to optimize a propane pre-cooled mixed-refrigerant (C3-MR) LNG plant modeled using HYSYS software. An optimization platform coupling Matlab with HYSYS was developed. New refrigerant mixtures were found, with savings in power consumption as high as 13%. LNG plants optimization with variable natural gas feed compositions was addressed and the solution was proposed through applying robust optimization techniques, resulting in a robust refrigerant which can liquefy a range of natural gas feeds. The second approach for reducing the power consumption is through process integration and waste heat utilization in the integrated CCS system. Four waste heat sources and six potential uses were uncovered and evaluated using HYSYS software. The developed models were verified against experimental data from the literature with good agreement. Net available power enhancement in one of the proposed CCS configuration is 16% more than the conventional CCS configuration. To reduce the CO2 pressurization power into a well for enhanced oil recovery (EOR) applications, five CO2 pressurization methods were explored. New CO2 liquefaction cycles were developed and modeled using HYSYS software. One of the developed liquefaction cycles using NH3 as a refrigerant resulted in 5% less power consumption than the conventional multi-stage compression cycle. Finally, a new concept of providing the CO2 regeneration heat is proposed. The proposed concept is using a heat pump to provide the regeneration heat as well as process heat and CO2 liquefaction heat. Seven configurations of heat pumps integrated with CCS were developed. One of the heat pumps consumes 24% less power than the conventional system or 59% less total equivalent power demand than the conventional system with steam extraction and CO2 compression.
Optimal control, investment and utilization schemes for energy storage under uncertainty
NASA Astrophysics Data System (ADS)
Mirhosseini, Niloufar Sadat
Energy storage has the potential to offer new means for added flexibility on the electricity systems. This flexibility can be used in a number of ways, including adding value towards asset management, power quality and reliability, integration of renewable resources and energy bill savings for the end users. However, uncertainty about system states and volatility in system dynamics can complicate the question of when to invest in energy storage and how best to manage and utilize it. This work proposes models to address different problems associated with energy storage within a microgrid, including optimal control, investment, and utilization. Electric load, renewable resources output, storage technology cost and electricity day-ahead and spot prices are the factors that bring uncertainty to the problem. A number of analytical methodologies have been adopted to develop the aforementioned models. Model Predictive Control and discretized dynamic programming, along with a new decomposition algorithm are used to develop optimal control schemes for energy storage for two different levels of renewable penetration. Real option theory and Monte Carlo simulation, coupled with an optimal control approach, are used to obtain optimal incremental investment decisions, considering multiple sources of uncertainty. Two stage stochastic programming is used to develop a novel and holistic methodology, including utilization of energy storage within a microgrid, in order to optimally interact with energy market. Energy storage can contribute in terms of value generation and risk reduction for the microgrid. The integration of the models developed here are the basis for a framework which extends from long term investments in storage capacity to short term operational control (charge/discharge) of storage within a microgrid. In particular, the following practical goals are achieved: (i) optimal investment on storage capacity over time to maximize savings during normal and emergency operations; (ii) optimal market strategy of buy and sell over 24-hour periods; (iii) optimal storage charge and discharge in much shorter time intervals.
NASA Technical Reports Server (NTRS)
Rarig, P. L.
1980-01-01
A program to calculate upwelling infrared radiation was modified to operate efficiently on the STAR-100. The modified software processes specific test cases significantly faster than the initial STAR-100 code. For example, a midlatitude summer atmospheric model is executed in less than 2% of the time originally required on the STAR-100. Furthermore, the optimized program performs extra operations to save the calculated absorption coefficients. Some of the advantages and pitfalls of virtual memory and vector processing are discussed along with strategies used to avoid loss of accuracy and computing power. Results from the vectorized code, in terms of speed, cost, and relative error with respect to serial code solutions are encouraging.
Gordon M. Heisler
1991-01-01
Saving energy has recently acquired new importance because of increased concern for dwindling fossil fuel supplies and for the problem of carbon dioxide contributions to global climate change. Many studies have indicated that windbreaks have the ability to save energy for heating buildings. Suggested savings have ranged up 40 percent; though more commonly savings of...
Review on Water Distribution of Cooling Tower in Power Station
NASA Astrophysics Data System (ADS)
Huichao, Zhang; Lei, Fang; Hao, Guang; Ying, Niu
2018-04-01
As the energy sources situation is becoming more and more severe, the importance of energy conservation and emissions reduction gets clearer. Since the optimization of water distribution system of cooling tower in power station can save a great amount of energy, the research of water distribution system gets more attention nowadays. This paper summarizes the development process of counter-flow type natural draft wet cooling tower and the water distribution system, and introduces the related domestic and international research situation. Combining the current situation, we come to the conclusion about the advantages and disadvantages of the several major water distribution modes, and analyze the problems of the existing water distribution ways in engineering application, furthermore, we put forward the direction of water distribution mode development on the basis knowledge of water distribution of cooling tower. Due to the water system can hardly be optimized again when it’s built, choosing an appropriate water distribution mode according to actual condition seems to be more significant.
A Methodology for the Optimization of Disaggregated Space System Conceptual Designs
2015-06-18
orbit disaggregated space systems. Savings of $82 million are identified for an optimized fire detection system. Savings of $5.7 billion are...solutions and update architecture ................................................................31 Fire detection problem...149 Figure 30 – Example cost vs. weighted mean science return output [37] ...................... 153 Figure 31
Energy conservation and money savings through the use of diesel-powered trucks.
DOT National Transportation Integrated Search
1980-01-01
This report presents an analysis of the potential energy and money savings to be achieved from the increased use of class 7, diesel-powered, 4-yard dump trucks by the Department. The technical differences between diesel and gasoline power plants are ...
Optimizing Aircraft Trajectories with Multiple Cruise Altitudes in the Presence of Winds
NASA Technical Reports Server (NTRS)
Ng, Hok K.; Sridhar, Banavar; Grabbe, Shon
2014-01-01
This study develops a trajectory optimization algorithm for approximately minimizing aircraft travel time and fuel burn by combining a method for computing minimum-time routes in winds on multiple horizontal planes, and an aircraft fuel burn model for generating fuel-optimal vertical profiles. It is applied to assess the potential benefits of flying user-preferred routes for commercial cargo flights operating between Anchorage, Alaska and major airports in Asia and the contiguous United States. Flying wind optimal trajectories with a fuel-optimal vertical profile reduces average fuel burn of international flights cruising at a single altitude by 1-3 percent. The potential fuel savings of performing en-route step climbs are not significant for many shorter domestic cargo flights that have only one step climb. Wind-optimal trajectories reduce fuel burn and travel time relative to the flight plan route by up to 3 percent for the domestic cargo flights. However, for trans-oceanic traffic, the fuel burn savings could be as much as 10 percent. The actual savings in operations will vary from the simulation results due to differences in the aircraft models and user defined cost indices. In general, the savings are proportional to trip length, and depend on the en-route wind conditions and aircraft types.
Development of Android based Smart Power Saving System
NASA Astrophysics Data System (ADS)
Gupta, Ashutosh; Kumar, Pradeep; Ghosh, Tathagata; Bhawna, Shruthi. S.
2017-08-01
An android based smart power saving system has been presented in this paper. For this purpose, an application is developed for controlling the intensity of an AC supply using a dimmer circuit in android platform and to monitor the current flow on different intensity level a current sensor is used in the circuit. Dimmer circuit provides a 16-different intensity level to control the flow of current and help in power saving. The system is very simple and robust as it is based on android platform.
NASA Astrophysics Data System (ADS)
Chao, Zhiqiang; Mao, Feiyue; Liu, Xiangbo; Li, Huaying; Han, Shousong
2017-01-01
In view of the large power of armored vehicle cooling system, the demand for high fan speed control and energy saving, this paper expounds the basic composition and principle of hydraulic-driven fan system and establishes the mathematical model of the system. Through the simulation analysis of different parameters, such as displacement of motor and working volume of fan system, the influences of performance parameters on the dynamic characteristic of hydraulic-driven fan system are obtained, which can provide theoretical guidance for system optimization design.
Multiantenna Relay Beamforming Design for QoS Discrimination in Two-Way Relay Networks
Xiong, Ke; Zhang, Yu; Li, Dandan; Zhong, Zhangdui
2013-01-01
This paper investigates the relay beamforming design for quality of service (QoS) discrimination in two-way relay networks. The purpose is to keep legitimate two-way relay users exchange their information via a helping multiantenna relay with QoS guarantee while avoiding the exchanged information overhearing by unauthorized receiver. To this end, we propose a physical layer method, where the relay beamforming is jointly designed with artificial noise (AN) which is used to interfere in the unauthorized user's reception. We formulate the joint beamforming and AN (BFA) design into an optimization problem such that the received signal-to-interference-ratio (SINR) at the two legitimate users is over a predefined QoS threshold while limiting the received SINR at the unauthorized user which is under a certain secure threshold. The objective of the optimization problem is to seek the optimal AN and beamforming vectors to minimize the total power consumed by the relay node. Since the optimization problem is nonconvex, we solve it by using semidefinite program (SDP) relaxation. For comparison, we also study the optimal relay beamforming without using AN (BFO) under the same QoS discrimination constraints. Simulation results show that both the proposed BFA and BFO can achieve the QoS discrimination of the two-way transmission. However, the proposed BFA yields significant power savings and lower infeasible rates compared with the BFO method. PMID:24391459
An integral nuclear power and propulsion system concept
NASA Astrophysics Data System (ADS)
Choong, Phillip T.; Teofilo, Vincent L.; Begg, Lester L.; Dunn, Charles; Otting, William
An integral space power concept provides both the electrical power and propulsion from a common heat source and offers superior performance capabilities over conventional orbital insertion using chemical propulsion systems. This paper describes a hybrid (bimodal) system concept based on a proven, inherently safe solid fuel form for the high temperature reactor core operation and rugged planar thermionic energy converter for long-life steady state electric power production combined with NERVA-based rocket technology for propulsion. The integral system is capable of long-life power operation and multiple propulsion operations. At an optimal thrust level, the integral system can maintain the minimal delta-V requirement while minimizing the orbital transfer time. A trade study comparing the overall benefits in placing large payloads to GEO with the nuclear electric propulsion option shows superiority of nuclear thermal propulsion. The resulting savings in orbital transfer time and the substantial reduction of overall lift requirement enables the use of low-cost launchers for several near-term military satellite missions.
Dixit, Abhishek; Lannoo, Bart; Colle, Didier; Pickavet, Mario; Demeester, Piet
2012-12-10
The optical network unit (ONU), installed at a customer's premises, accounts for about 60% of power in current fiber-to-the-home (FTTH) networks. We propose a power consumption model for the ONU and evaluate the ONU power consumption in various next generation optical access (NGOA) architectures. Further, we study the impact of the power savings of the ONU in various low power modes such as power shedding, doze and sleep.
Cross-layer Energy Optimization Under Image Quality Constraints for Wireless Image Transmissions.
Yang, Na; Demirkol, Ilker; Heinzelman, Wendi
2012-01-01
Wireless image transmission is critical in many applications, such as surveillance and environment monitoring. In order to make the best use of the limited energy of the battery-operated cameras, while satisfying the application-level image quality constraints, cross-layer design is critical. In this paper, we develop an image transmission model that allows the application layer (e.g., the user) to specify an image quality constraint, and optimizes the lower layer parameters of transmit power and packet length, to minimize the energy dissipation in image transmission over a given distance. The effectiveness of this approach is evaluated by applying the proposed energy optimization to a reference ZigBee system and a WiFi system, and also by comparing to an energy optimization study that does not consider any image quality constraint. Evaluations show that our scheme outperforms the default settings of the investigated commercial devices and saves a significant amount of energy at middle-to-large transmission distances.
Guimarães, Dayan Adionel; Sakai, Lucas Jun; Alberti, Antonio Marcos; de Souza, Rausley Adriano Amaral
2016-01-01
In this paper, a simple and flexible method for increasing the lifetime of fixed or mobile wireless sensor networks is proposed. Based on past residual energy information reported by the sensor nodes, the sink node or another central node dynamically optimizes the communication activity levels of the sensor nodes to save energy without sacrificing the data throughput. The activity levels are defined to represent portions of time or time-frequency slots in a frame, during which the sensor nodes are scheduled to communicate with the sink node to report sensory measurements. Besides node mobility, it is considered that sensors’ batteries may be recharged via a wireless power transmission or equivalent energy harvesting scheme, bringing to the optimization problem an even more dynamic character. We report large increased lifetimes over the non-optimized network and comparable or even larger lifetime improvements with respect to an idealized greedy algorithm that uses both the real-time channel state and the residual energy information. PMID:27657075
Guimarães, Dayan Adionel; Sakai, Lucas Jun; Alberti, Antonio Marcos; de Souza, Rausley Adriano Amaral
2016-09-20
In this paper, a simple and flexible method for increasing the lifetime of fixed or mobile wireless sensor networks is proposed. Based on past residual energy information reported by the sensor nodes, the sink node or another central node dynamically optimizes the communication activity levels of the sensor nodes to save energy without sacrificing the data throughput. The activity levels are defined to represent portions of time or time-frequency slots in a frame, during which the sensor nodes are scheduled to communicate with the sink node to report sensory measurements. Besides node mobility, it is considered that sensors' batteries may be recharged via a wireless power transmission or equivalent energy harvesting scheme, bringing to the optimization problem an even more dynamic character. We report large increased lifetimes over the non-optimized network and comparable or even larger lifetime improvements with respect to an idealized greedy algorithm that uses both the real-time channel state and the residual energy information.
Xu, Wei; Yan, Xiuhua; Shao, Rong; Chen, Ligen; Ke, Zengguang
Castor cake is the residue in castor oil production in which many active components exist and the major one among them is ricinine. In this study, optimization of extraction of ricinine from castor cake using ultrasonic-microwave synergistic extraction (UMSE) was investigated to obtain high yield and purity by Box-Behnken design (BBD) response surface design. The optimal conditions of extraction were: ultrasound power 342 W, extracting time 5 min, microwave power 395 W, and non-significant factor of liquid/solid ratio 1:10. The crude extraction was recrystallized from ethanol. As a result, the maximum yield of ricinine was approximately 67.52%. The purity of ricinine was 99.39% which was determined by high performance liquid chromatography (HPLC). Additionally, the structure of purified ricinine was identified by fourier transforms infrared (FTIR) and liquid chromatography-mass spectrometry (LC-MS). Scanning electron microscope (SEM) was used to characterize the prismatic crystals morphology of ricinine. Results demonstrated that the present method combined the advantages of ultrasonic extraction and microwave extraction, which is time-saving with high extraction yield. Our results offer a suitable method for large-scale isolation of ricinine.
Standardized EMCS Energy Savings Calculations.
1982-09-01
Reset 56 4.12 Boiler Optimization 57 4.13 Chiller Optimization 58 4.14 Chiller Water Temperature Reset 58 4.15 Condenser Water Temperature.Reset 59...gal, Btu/kwh, etc. (See page 32) 4.13 CHILLER OPTIMIZATION These savings are applicable only to chilled water plants with multiple chillers . The...temperature at end of shutdown period in OF To = hot water temperature setpoint in °F TON = chiller capacity in tons Ts = average temperature of surroundings in
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Jie; Cui, Mingjian; Hodge, Bri-Mathias
The large variability and uncertainty in wind power generation present a concern to power system operators, especially given the increasing amounts of wind power being integrated into the electric power system. Large ramps, one of the biggest concerns, can significantly influence system economics and reliability. The Wind Forecast Improvement Project (WFIP) was to improve the accuracy of forecasts and to evaluate the economic benefits of these improvements to grid operators. This paper evaluates the ramp forecasting accuracy gained by improving the performance of short-term wind power forecasting. This study focuses on the WFIP southern study region, which encompasses most ofmore » the Electric Reliability Council of Texas (ERCOT) territory, to compare the experimental WFIP forecasts to the existing short-term wind power forecasts (used at ERCOT) at multiple spatial and temporal scales. The study employs four significant wind power ramping definitions according to the power change magnitude, direction, and duration. The optimized swinging door algorithm is adopted to extract ramp events from actual and forecasted wind power time series. The results show that the experimental WFIP forecasts improve the accuracy of the wind power ramp forecasting. This improvement can result in substantial costs savings and power system reliability enhancements.« less
NASA Astrophysics Data System (ADS)
Feng, Jun-shu; Jin, Yan-ming; Hao, Wei-hua
2017-01-01
Based on modelling the environmental influence index of power transmission and transformation project and energy-saving and emission-reducing index of source-grid-load of power system, this paper establishes an objective decision model of power grid environmental protection, with constraints of power grid environmental protection objectives being legal and economical, and considering both positive and negative influences of grid on the environmental in all-life grid cycle. This model can be used to guide the programming work of power grid environmental protection. A numerical simulation of Jiangsu province’s power grid environmental protection objective decision model has been operated, and the results shows that the maximum goal of energy-saving and emission-reducing benefits would be reached firstly as investment increasing, and then the minimum goal of environmental influence.
Energy Saving in DC Electric Railways by Battery Substation
NASA Astrophysics Data System (ADS)
Sugimoto, Takeshi
New rolling vehicles used in dc electric railways are of the regenerative type. At less busy time a part of regenerative power is not used for powering vehicles, and canceled by changed air brake. Recently, significant attention has been paid to the development of secondary batteries for hybrid and electric motorcars. The use of this battery enables reduction in electric power consumption. Because we can charge excess regenerative power and use for powering vehicles after. Before the fact we compared the actual and simulated effective coefficient of regenerative energy, we confirmed the suitability of the simulation model. In this simulation, we studied the energy-saving effect of the battery substations and determined the battery capacity at which maximum power saving is achieved. We found that the power consumption could be reduced remarkably by using a 15-20kWh battery substation.
Comparison of all-electric secondary power systems for civil transport
NASA Technical Reports Server (NTRS)
Renz, David D.
1992-01-01
Three separate studies have shown operational, weight, and cost advantages for commercial subsonic transport aircraft using an all-electric secondary power system. The first study in 1982 showed that all-electric secondary power systems produced the second largest benefit compared to four other technology upgrades. The second study in 1985 showed a 10 percent weight and fuel savings using an all-electric high frequency (20 kHz) secondary power system. The last study in 1991 showed a 2 percent weight savings using today's technology (400 Hz) in an all-electric secondary power system. This paper will compare the 20 kHz and 400 Hz studies, analyze the 2 to 10 percent difference in weight savings and comment on the common benefits of the all-electric secondary power system.
Comparison of all-electric secondary power systems for civil subsonic transports
NASA Technical Reports Server (NTRS)
Renz, David D.
1992-01-01
Three separate studies have shown operational, weight, and cost advantages for commercial subsonic transport aircraft using an all-electric secondary power system. The first study in 1982 showed that all-electric secondary power systems produced the second largest benefit compared to four other technology upgrades. The second study in 1985 showed a 10 percent weight and fuel savings using an all-electric high frequency (20 kHz) secondary power system. The last study in 1991 showed a 2 percent weight savings using today's technology (400 Hz) in an all-electric secondary power system. This paper will compare the 20 kHz and 400 Hz studies, analyze the 2 to 10 percent difference in weight savings and comment on the common benefits of the all-electric secondary power system.
Energy saving in data processing and communication systems.
Iazeolla, Giuseppe; Pieroni, Alessandra
2014-01-01
The power management of ICT systems, that is, data processing (Dp) and telecommunication (Tlc) systems, is becoming a relevant problem in economical terms. Dp systems totalize millions of servers and associated subsystems (processors, monitors, storage devices, etc.) all over the world that need to be electrically powered. Dp systems are also used in the government of Tlc systems, which, besides requiring Dp electrical power, also require Tlc-specific power, both for mobile networks (with their cell-phone towers and associated subsystems: base stations, subscriber stations, switching nodes, etc.) and for wired networks (with their routers, gateways, switches, etc.). ICT research is thus expected to investigate into methods to reduce Dp- and Tlc-specific power consumption. However, saving power may turn into waste of performance, in other words, into waste of ICT quality of service (QoS). This paper investigates the Dp and Tlc power management policies that look at compromises between power saving and QoS.
Energy Savings Measure Packages. Existing Homes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Casey, Sean; Booten, Chuck
2011-11-01
This document presents the most cost effective Energy Savings Measure Packages (ESMP) for existing mixed-fuel and all electric homes to achieve 15% and 30% savings for each BetterBuildings grantee location across the United States. These packages are optimized for minimum cost to homeowners for source energy savings given the local climate and prevalent building characteristics (i.e. foundation types). Maximum cost savings are typically found between 30% and 50% energy savings over the reference home; this typically amounts to $300 - $700/year.
NASA Astrophysics Data System (ADS)
Li, Jin; Qiu, Zhiling; Hu, Leilei
2018-04-01
The inverter-based regenerative braking power utilization devices can re-utilize the regenerative energy, thus reduce the energy consumption of urban rail transit. In this paper the power absorption principle of the inverter-based device is introduced, then the key influencing factors of energy saving performance are analyzed based on the absorption model. The field operation data verified that the control DC voltage plays an important role and lower control DC voltage yields more energy saving. Also, the one year energy saving performance data of an inverter-based re-utilization device located in NanJing S8 line is provided, and more than 1.2 million kWh energy is recovered in the one year operation.
Energy-saving management modelling and optimization for lead-acid battery formation process
NASA Astrophysics Data System (ADS)
Wang, T.; Chen, Z.; Xu, J. Y.; Wang, F. Y.; Liu, H. M.
2017-11-01
In this context, a typical lead-acid battery producing process is introduced. Based on the formation process, an efficiency management method is proposed. An optimization model with the objective to minimize the formation electricity cost in a single period is established. This optimization model considers several related constraints, together with two influencing factors including the transformation efficiency of IGBT charge-and-discharge machine and the time-of-use price. An example simulation is shown using PSO algorithm to solve this mathematic model, and the proposed optimization strategy is proved to be effective and learnable for energy-saving and efficiency optimization in battery producing industries.
Machine learning techniques for energy optimization in mobile embedded systems
NASA Astrophysics Data System (ADS)
Donohoo, Brad Kyoshi
Mobile smartphones and other portable battery operated embedded systems (PDAs, tablets) are pervasive computing devices that have emerged in recent years as essential instruments for communication, business, and social interactions. While performance, capabilities, and design are all important considerations when purchasing a mobile device, a long battery lifetime is one of the most desirable attributes. Battery technology and capacity has improved over the years, but it still cannot keep pace with the power consumption demands of today's mobile devices. This key limiter has led to a strong research emphasis on extending battery lifetime by minimizing energy consumption, primarily using software optimizations. This thesis presents two strategies that attempt to optimize mobile device energy consumption with negligible impact on user perception and quality of service (QoS). The first strategy proposes an application and user interaction aware middleware framework that takes advantage of user idle time between interaction events of the foreground application to optimize CPU and screen backlight energy consumption. The framework dynamically classifies mobile device applications based on their received interaction patterns, then invokes a number of different power management algorithms to adjust processor frequency and screen backlight levels accordingly. The second strategy proposes the usage of machine learning techniques to learn a user's mobile device usage pattern pertaining to spatiotemporal and device contexts, and then predict energy-optimal data and location interface configurations. By learning where and when a mobile device user uses certain power-hungry interfaces (3G, WiFi, and GPS), the techniques, which include variants of linear discriminant analysis, linear logistic regression, non-linear logistic regression, and k-nearest neighbor, are able to dynamically turn off unnecessary interfaces at runtime in order to save energy.
NASA Astrophysics Data System (ADS)
Baek, Sangkyu; Choi, Bong Dae
We investigate power consumption of a mobile station with the power saving class of type 1 in the IEEE 802.16e. We deal with stochastic behavior of mobile station during not only sleep mode period but also awake mode period with both downlink and uplink traffics. Our methods for investigating the power saving class of type 1 are to construct the embedded Markov chain and the semi-Markov chain generated by the embedded Markov chain. To see the effect of the sleep mode, we obtain the average power consumption of a mobile station and the mean queueing delay of a message. Numerical results show that the larger size of the sleep window makes the power consumption of a mobile station smaller and the queueing delay of a downlink message longer.
NASA Astrophysics Data System (ADS)
Darling, R. G.
2016-12-01
The FAA's policies for agricultural Unmanned Aerial Systems (UAS) is essential towards preservation and optimization of water use in the parched Western United States. Had FAA applied emergency rules putting farmers on equal-footing with hobbyists for sUAS use at the beginning of the 2012 drought, the Western US could have been able to save approximately 3 Million/AF of water through improved irrigation management. For perspective, Los Angeles city's annual current consumption is 587,000 acre-feet. This study uses various assumptions about developed water use in agriculture and urban areas to determine water use, energy consumption, monetary loss through delay in FAA regulations. If the saved water was added to the ground the energy savings could have been approximately 1.27 Terra-Watt hours, enough energy to power the entire University of California system for 5 years. It remains unclear if new FAA regulations are sufficiently permissive to allow for widespread adoption of sUAS based precision agriculture. Substantial opportunities exist for utilizing UAS traffic management software in rural areas of less crowed airspace: incorporating geofencing and a notification system to operators and air traffic control as an alternative to a difficult examination process.
Space Station Reboost with Electrodynamic Tethers
NASA Technical Reports Server (NTRS)
Vas, Irwin E.; Kelly, Thomas J.; Scarl, Ethan A.
1999-01-01
This paper presents the results of a study of an electrodynamic tether system to reboost the International Space Station (ISS). One recommendation is to use a partially bare tether for electron collection. Locations are suggested as to where the tether system is to be attached at the space station. The effects of the tether system on the microgravity environment may actually be beneficial, because the system can neutralize aerodrag during quiescent periods and, if deployed from a movable boom, can permit optimization of laboratory positioning with respect to acceleration contours. Alternative approaches to tether deployment and retrieval are discussed. It is shown that a relatively short tether system, 7 km long, operating at a power level of 5 kW could provide cumulative savings or over a billion dollars during a 10-year period ending in 2012. This savings is the direct result of a reduction in the number or nights that would otherwise be required to deliver propellant for reboost, with larger cost savings for higher tether usage. In addition to economic considerations, an electrodynamic tether promises a practical backup system that could ensure ISS survival in the event of an (otherwise) catastrophic delay in propellant delivery.
An aging society: opportunity or challenge?
Cutler, D M; Poterba, J M; Sheiner, L M; Summers, L H
1990-01-01
"This paper steps back from the current political debate [in the United States] over the social security trust fund and examines the more general question of how serious a macroeconomic problem aging is and how policy should respond to it. We focus primarily on issues relating to saving and capital accumulation. We do not consider the broader question of whether the current U.S. national saving rate is too high or too low, but focus on the effect of demographic changes on the optimal level of national saving. In addition, we consider the effects of demographic change on productivity growth and the optimal timing of tax collections. Our general conclusion is that demographic changes will improve American standards of living in the near future, but lower them slightly over the very long term. Other things being equal, the optimal policy response to recent and anticipated demographic changes is almost certainly a reduction rather than an increase in the national saving rate." excerpt
NASA Astrophysics Data System (ADS)
Deng, Lujuan; Xie, Songhe; Cui, Jiantao; Liu, Tao
2006-11-01
It is the essential goal of intelligent greenhouse environment optimal control to enhance income of cropper and energy save. There were some characteristics such as uncertainty, imprecision, nonlinear, strong coupling, bigger inertia and different time scale in greenhouse environment control system. So greenhouse environment optimal control was not easy and especially model-based optimal control method was more difficult. So the optimal control problem of plant environment in intelligent greenhouse was researched. Hierarchical greenhouse environment control system was constructed. In the first level data measuring was carried out and executive machine was controlled. Optimal setting points of climate controlled variable in greenhouse was calculated and chosen in the second level. Market analysis and planning were completed in third level. The problem of the optimal setting point was discussed in this paper. Firstly the model of plant canopy photosynthesis responses and the model of greenhouse climate model were constructed. Afterwards according to experience of the planting expert, in daytime the optimal goals were decided according to the most maximal photosynthesis rate principle. In nighttime on plant better growth conditions the optimal goals were decided by energy saving principle. Whereafter environment optimal control setting points were computed by GA. Compared the optimal result and recording data in real system, the method is reasonable and can achieve energy saving and the maximal photosynthesis rate in intelligent greenhouse
76 FR 20459 - Savings and Loan Holding Company Application
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-12
... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Savings and Loan Holding Company... concerning the following information collection. Title of Proposal: Savings and Loan Holding Company... officer of a savings and loan holding company, or any individual who owns, controls, or holds with power...
Saving in cycles: how to get people to save more money.
Tam, Leona; Dholakia, Utpal
2014-02-01
Low personal savings rates are an important social issue in the United States. We propose and test one particular method to get people to save more money that is based on the cyclical time orientation. In contrast to conventional, popular methods that encourage individuals to ignore past mistakes, focus on the future, and set goals to save money, our proposed method frames the savings task in cyclical terms, emphasizing the present. Across the studies, individuals who used our proposed cyclical savings method, compared with individuals who used a linear savings method, provided an average of 74% higher savings estimates and saved an average of 78% more money. We also found that the cyclical savings method was more efficacious because it increased implementation planning and lowered future optimism regarding saving money.
Control of Smart Building Using Advanced SCADA
NASA Astrophysics Data System (ADS)
Samuel, Vivin Thomas
For complete control of the building, a proper SCADA implementation and the optimization strategy has to be build. For better communication and efficiency a proper channel between the Communication protocol and SCADA has to be designed. This paper concentrate mainly between the communication protocol, and the SCADA implementation, for a better optimization and energy savings is derived to large scale industrial buildings. The communication channel used in order to completely control the building remotely from a distant place. For an efficient result we consider the temperature values and the power ratings of the equipment so that while controlling the equipment, we are setting a threshold values for FDD technique implementation. Building management system became a vital source for any building to maintain it and for safety purpose. Smart buildings, refers to various distinct features, where the complete automation system, office building controls, data center controls. ELC's are used to communicate the load values of the building to the remote server from a far location with the help of an Ethernet communication channel. Based on the demand fluctuation and the peak voltage, the loads operate differently increasing the consumption rate thus results in the increase in the annual consumption bill. In modern days, saving energy and reducing the consumption bill is most essential for any building for a better and long operation. The equipment - monitored regularly and optimization strategy is implemented for cost reduction automation system. Thus results in the reduction of annual cost reduction and load lifetime increase.
Wireless sensor and actuator networks for lighting energy efficiency and user satisfaction
NASA Astrophysics Data System (ADS)
Wen, Yao-Jung
Buildings consume more than one third of the primary energy generated in the U.S., and lighting alone accounts for approximately 30% of the energy usage in commercial buildings. As the largest electricity consumer of all building electrical systems, lighting harbors the greatest potential for energy savings in the commercial sector. Fifty percent of current energy consumption could be reduced with energy-efficient lighting management strategies. While commercial products do exist, they are poorly received due to exorbitant retrofitting cost and unsatisfactory performance. As a result, most commercial buildings, especially legacy buildings, have not taken advantage of the opportunity to generate savings from lighting. The emergence of wireless sensor and actuator network (WSAN) technologies presents an alternative that circumvents costly rewiring and promises better performance than existing commercial lighting systems. The goal of this dissertation research is to develop a framework for wireless-networked lighting systems with increased cost effectiveness, energy efficiency, and user satisfaction. This research is realized through both theoretical developments and implementations. The theoretical research aims at developing techniques for harnessing WSAN technologies to lighting hardware and control strategies. Leveraging redundancy, a sensor validation and fusion algorithm is developed for extracting pertinent lighting information from the disturbance-prone desktop-mounted photosensors. An adaptive sensing strategy optimizes the timing of data acquisition and power-hungry wireless transmission of sensory feedback in real-time lighting control. Exploiting the individual addressability of wireless-enabled luminaires, a lighting optimization algorithm is developed to create the optimal lighting that minimizes energy usage while satisfying occupants' diverse lighting preferences. The wireless-networked lighting system was implemented and tested in a number of real-life settings. A human subject study conducted in a private office concluded that the research system was competitive with the commercial lighting system with much fewer retrofitting requirements. The system implemented in a shared-space office realized a self-configuring mesh network with wireless photosensors and light actuators, and demonstrated a 50% energy savings and increased performance when harvesting daylight through windows is possible. The cost analysis revealed a reasonable payback period after the system is optimized for commercialization and confirms the marketing feasibility.
Concept for a power system controller for large space electrical power systems
NASA Technical Reports Server (NTRS)
Lollar, L. F.; Lanier, J. R., Jr.; Graves, J. R.
1981-01-01
The development of technology for a fail-operatonal power system controller (PSC) utilizing microprocessor technology for managing the distribution and power processor subsystems of a large multi-kW space electrical power system is discussed. The specific functions which must be performed by the PSC, the best microprocessor available to do the job, and the feasibility, cost savings, and applications of a PSC were determined. A limited function breadboard version of a PSC was developed to demonstrate the concept and potential cost savings.
This paper provides the EPA Combined Heat and Power Partnership's recommended methodology for calculating fuel and carbon dioxide emissions savings from CHP compared to SHP, which serves as the basis for the EPA's CHP emissions calculator.
NASA Astrophysics Data System (ADS)
Pham, John Dinh Chuong
In the twenty first century, global warming and climate change have become environmental issues worldwide. There is a need to reduce greenhouse gas emissions from thermal power plants through improved efficiency. This need is shared by both developed and developing countries. It is particularly important in rapidly developing economies (for example, Vietnam, South Korea, and China) where there is very significant need to increase generation capacity. This thesis addresses improving thermal power plant efficiency through an improved planning process that emphasizes integrated design. With the integration of planning and design considerations of key components in thermal electrical generation, along with the selection of appropriate up-to-date technologies, greater efficiency and reduction of emissions could be achieved. The major barriers to the integration of overall power plant optimization are the practice of individual island tendering packages, and the lack of coordinating efforts between major original equipment manufacturers (OEM). This thesis assesses both operational and design aspects of thermal power plants to identify opportunities for energy saving and the associated reduction of CO2 emissions. To demonstrate the potential of the integrated planning design approach, three advanced thermal power plants, using anthracite coal, oil and gas as their respective fuel, were developed as a case study. The three plant formulations and simulations were performed with the cooperation of several leading companies in the power industry including Babcock & Wilcox, Siemens KWU, Siemens-Westinghouse Power Corporation, Hitachi, Alstom Air Preheater, TLT-Covent, and ABB Flakt. The first plant is a conventional W-Flame anthracite coal-fired unit for base load operation. The second is a supercritical oil-fired plant with advanced steam condition, for two shifting and cycling operations. The third plant is a gas-fired combined cycle unit employing a modern steam-cooled gas turbine and a three-pressure heat recovery steam generator with reheat, for base load and load following operations. The oil-fired and gas-fired plants showed excellent gross thermal efficiency, 49.6 and 59.4 percent, respectively. Regarding the anthracite plant, based on a traditional subcritical pressure steam cycle, the unit gross efficiency was calculated at 42.3 percent. These efficiency values represent an increase of over 2 percent compared to the comparable plant class, operating today. This 2 percent efficiency gained translates into approximately 35,000 tonnes of greenhouse gas reduction, and a saving of 16,000 tonnes of coal, per year (based on 300MWe coal-fired plant). The positive results from the three simulations have demonstrated that by integrating planning and design optimization, significant gain of efficiency in thermal power plants is possible. This establishes the need for improved planning processes. It starts with a pre-planning process, before project tendering, to identify applicable operational issues and design features to enhance efficiency and reduce emissions. It should also include a pre-contract period to provide an opportunity for all OEM finalists to consolidate and fine-tune their designs for compatibility with those of others to achieve optimal performance. The inclusion of a period for final consolidation and integrated design enables the original goals of greater overall plant efficiency and greenhouse gas emissions reduction to be achieved beyond those available from current planning and contracting procedures.
Memory-Based Structured Application Specific Integrated Circuit (ASIC) Study
2008-10-01
memory interface, arbiter/ schedulers for rescheduling the memory requests according to some schedule policy, and memory channels for communicating...between the power-savings and the wakeup overhead with respect to both wakeup power and wakeup delay. For example, dream mode can save 50% more static...power than sleep mode, but at the expense of twice the wake delay and three times the wakeup energy. The user can specify power-gating modes for various components.
Optimal Time-Resource Allocation for Energy-Efficient Physical Activity Detection
Thatte, Gautam; Li, Ming; Lee, Sangwon; Emken, B. Adar; Annavaram, Murali; Narayanan, Shrikanth; Spruijt-Metz, Donna; Mitra, Urbashi
2011-01-01
The optimal allocation of samples for physical activity detection in a wireless body area network for health-monitoring is considered. The number of biometric samples collected at the mobile device fusion center, from both device-internal and external Bluetooth heterogeneous sensors, is optimized to minimize the transmission power for a fixed number of samples, and to meet a performance requirement defined using the probability of misclassification between multiple hypotheses. A filter-based feature selection method determines an optimal feature set for classification, and a correlated Gaussian model is considered. Using experimental data from overweight adolescent subjects, it is found that allocating a greater proportion of samples to sensors which better discriminate between certain activity levels can result in either a lower probability of error or energy-savings ranging from 18% to 22%, in comparison to equal allocation of samples. The current activity of the subjects and the performance requirements do not significantly affect the optimal allocation, but employing personalized models results in improved energy-efficiency. As the number of samples is an integer, an exhaustive search to determine the optimal allocation is typical, but computationally expensive. To this end, an alternate, continuous-valued vector optimization is derived which yields approximately optimal allocations and can be implemented on the mobile fusion center due to its significantly lower complexity. PMID:21796237
NASA Astrophysics Data System (ADS)
Qyyum, Muhammad Abdul; Long, Nguyen Van Duc; Minh, Le Quang; Lee, Moonyong
2018-01-01
Design optimization of the single mixed refrigerant (SMR) natural gas liquefaction (LNG) process involves highly non-linear interactions between decision variables, constraints, and the objective function. These non-linear interactions lead to an irreversibility, which deteriorates the energy efficiency of the LNG process. In this study, a simple and highly efficient hybrid modified coordinate descent (HMCD) algorithm was proposed to cope with the optimization of the natural gas liquefaction process. The single mixed refrigerant process was modeled in Aspen Hysys® and then connected to a Microsoft Visual Studio environment. The proposed optimization algorithm provided an improved result compared to the other existing methodologies to find the optimal condition of the complex mixed refrigerant natural gas liquefaction process. By applying the proposed optimization algorithm, the SMR process can be designed with the 0.2555 kW specific compression power which is equivalent to 44.3% energy saving as compared to the base case. Furthermore, in terms of coefficient of performance (COP), it can be enhanced up to 34.7% as compared to the base case. The proposed optimization algorithm provides a deep understanding of the optimization of the liquefaction process in both technical and numerical perspectives. In addition, the HMCD algorithm can be employed to any mixed refrigerant based liquefaction process in the natural gas industry.
Nassiri, Nader; Sheibani, Kourosh; Azimi, Abbas; Khosravi, Farinaz Mahmoodi; Heravian, Javad; Yekta, Abasali; Moghaddam, Hadi Ostadi; Nassiri, Saman; Yasseri, Mehdi; Nassiri, Nariman
2015-10-01
To compare refractive outcomes, contrast sensitivity, higher-order aberrations (HOAs), and patient satisfaction after photorefractive keratectomy for correction of moderate myopia with two methods: tissue saving versus wavefront optimized. In this prospective, comparative study, 152 eyes (80 patients) with moderate myopia with and without astigmatism were randomly divided into two groups: the tissue-saving group (Technolas 217z Zyoptix laser; Bausch & Lomb, Rochester, NY) (76 eyes of 39 patients) or the wavefront-optimized group (WaveLight Allegretto Wave Eye-Q laser; Alcon Laboratories, Inc., Fort Worth, TX) (76 eyes of 41 patients). Preoperative and 3-month postoperative refractive outcomes, contrast sensitivity, HOAs, and patient satisfaction were compared between the two groups. The mean spherical equivalent was -4.50 ± 1.02 diopters. No statistically significant differences were detected between the groups in terms of uncorrected and corrected distance visual acuity and spherical equivalent preoperatively and 3 months postoperatively. No statistically significant differences were seen in the amount of preoperative to postoperative contrast sensitivity changes between the two groups in photopic and mesopic conditions. HOAs and Q factor increased in both groups postoperatively (P = .001), with the tissue-saving method causing more increases in HOAs (P = .007) and Q factor (P = .039). Patient satisfaction was comparable between both groups. Both platforms were effective in correcting moderate myopia with or without astigmatism. No difference in refractive outcome, contrast sensitivity changes, and patient satisfaction between the groups was observed. Postoperatively, the tissue-saving method caused a higher increase in HOAs and Q factor compared to the wavefront-optimized method, which could be due to larger optical zone sizes in the tissue-saving group. Copyright 2015, SLACK Incorporated.
OTTER: An Optimized Transit Tool And Easy Reference
2016-03-01
as stated in the CNO’s Position Report: 2014. While a number of fuel -saving measures have been implemented in recent years, the effects of...saving measures have been implemented in recent years, the effects of operational transit speed on fuel consumption have not been adequately...their estimated savings As clearly seen, operating configuration has the most effect by far on fuel savings. Source: Fonte S (2009). In 2015
Optimization of loading ratio of ErN as regenerator of 4K-GM cryocooler
NASA Astrophysics Data System (ADS)
Nakagawa, T.; Miyauchi, T.; Shiraishi, T.; Seino, S.; Yamamoto, T. A.; Fujimoto, Y.; Masuyama, S.
2017-09-01
High purity erbium nitride (ErN) spheres with the size range of 150-180 µm and 180-212 µm were prepared by nitriding Er metal spheres with low oxygen content. The initial regenerator material of HoCu2 on the cold end of the second regenerator column in 4K-GM cryocooler with nominal cooling power of 0.1 W at 4.2 K was replaced by ErN with different sizes. Higher cooling power was obtained when ErN of smaller size with lower oxygen content was used. We investigated the effect of partial replacement of HoCu2 by ErN in the cold end side of second stage regenerator column on cooling power of 4K-GM cryocoolers. When ErN were substituted for 20 % of HoCu2, the cooling power at 4.2 K reached 0.318 W. This value was 1.36 times as high as that of the cooling power of the GM cryocooler with commercially available regenerator arrangement. Therefore, use of ErN regenerator materials leads to the energy-saving and downsizing of 4K-GM cryocoolers.
A study of variable thrust, variable specific impulse trajectories for solar system exploration
NASA Astrophysics Data System (ADS)
Sakai, Tadashi
A study has been performed to determine the advantages and disadvantages of variable thrust and variable Isp (specific impulse) trajectories for solar system exploration. There have been several numerical research efforts for variable thrust, variable Isp, power-limited trajectory optimization problems. All of these results conclude that variable thrust, variable Isp (variable specific impulse, or VSI) engines are superior to constant thrust, constant Isp (constant specific impulse; or CSI) engines. However, most of these research efforts assume a mission from Earth to Mars, and some of them further assume that these planets are circular and coplanar. Hence they still lack the generality. This research has been conducted to answer the following questions: (1) Is a VSI engine always better than a CSI engine or a high thrust engine for any mission to any planet with any time of flight considering lower propellant mass as the sole criterion? (2) If a planetary swing-by is used for a VSI trajectory, is the fuel savings of a VSI swing-by trajectory better than that of a CSI swing-by or high thrust swing-by trajectory? To support this research, an unique, new computer-based interplanetary trajectory calculation program has been created. This program utilizes a calculus of variations algorithm to perform overall optimization of thrust, Isp, and thrust vector direction along a trajectory that minimizes fuel consumption for interplanetary travel. It is assumed that the propulsion system is power-limited, and thus the compromise between thrust and Isp is a variable to be optimized along the flight path. This program is capable of optimizing not only variable thrust trajectories but also constant thrust trajectories in 3-D space using a planetary ephemeris database. It is also capable of conducting planetary swing-bys. Using this program, various Earth-originating trajectories have been investigated and the optimized results have been compared to traditional CSI and high thrust trajectory solutions. Results show that VSI rocket engines reduce fuel requirements for any mission compared to CSI rocket engines. Fuel can be saved by applying swing-by maneuvers for VSI engines; but the effects of swing-bys due to VSI engines are smaller than that of CSI or high thrust engines.
Essays on Mathematical Optimization for Residential Demand Response in the Energy Sector
NASA Astrophysics Data System (ADS)
Palaparambil Dinesh, Lakshmi
In the electric utility industry, it could be challenging to adjust supply to match demand due to large generator ramp up times, high generation costs and insufficient in-house generation capacity. Demand response (DR) is a technique for adjusting the demand for electric power instead of the supply. Direct Load Control (DLC) is one of the ways to implement DR. DLC program participants sign up for power interruption contracts and are given financial incentives for curtailing electricity usage during peak demand time periods. This dissertation studies a DLC program for residential air conditioners using mathematical optimization models. First, we develop a model that determines what contract parameters to use in designing contracts between the provider and residential customers, when to turn which power unit on or off and how much power to cut during peak demand hours. The model uses information on customer preferences for choice of contract parameters such as DLC financial incentives and energy usage curtailment. In numerical experiments, the proposed model leads to projected cost savings of the order of 20%, compared to a current benchmark model used in practice. We also quantify the impact of factors leading to cost savings and study characteristics of customers picked by different contracts. Second, we study a DLC program in a macro economic environment using a Computable General Equilibrium (CGE) model. A CGE model is used to study the impact of external factors such as policy and technology changes on different economic sectors. Here we differentiate customers based on their preference for DLC programs by using different values for price elasticity of demand for electricity commodity. Consequently, DLC program customers could substitute demand for electricity commodity with other commodities such as transportation sector. Price elasticity of demand is calculated using a novel methodology that incorporates customer preferences for DLC contracts from the first model. The calculation of elasticity based on our methodology is useful since the prices of commodities are not only determined by aggregate demand and supply but also by customers' relative preferences for commodities. In addition to this we quantify the indirect substitution and rebound effects on sectoral activity levels, incomes and prices based on customer differences, when DLC is implemented.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Palchak, David; Cochran, Jaquelin; Deshmukh, Ranjit
The use of renewable energy (RE) sources, primarily wind and solar generation, is poised to grow significantly within the Indian power system. The Government of India has established a target of 175 gigawatts (GW) of installed RE capacity by 2022, including 60 GW of wind and 100 GW of solar, up from 29 GW wind and 9 GW solar at the beginning of 2017. Using advanced weather and power system modeling made for this project, the study team is able to explore operational impacts of meeting India’s RE targets and identify actions that may be favorable for integration. Our primarymore » tool is a detailed production cost model, which simulates optimal scheduling and dispatch of available generation in a future year (2022) by minimizing total production costs subject to physical, operational, and market constraints. Our team comprises a core group from the Power System Operation Corporation, Ltd. (POSOCO), which is the national grid operator (with representation from the National, Southern, and Western Regional Load Dispatch Centers) under Ministry of Power, National Renewable Energy Laboratory (NREL), and Lawrence Berkeley National Laboratory (Berkeley Lab), and a broader modeling team that includes Central Electricity Authority (CEA), POWERGRID (the central transmission utility, CTU), and State Load Dispatch Centers in Maharashtra, Gujarat, Tamil Nadu, Karnataka, Rajasthan, and Andhra Pradesh. Our model includes high-resolution wind and solar data (forecasts and actuals), unique properties for each generator, CEA/CTU’s anticipated buildout of the power system, and enforced state-to-state transmission flows. Assuming the fulfillment of current efforts to provide better access to the physical flexibility of the power system, we find that power system balancing with 100 GW of solar and 60 GW of wind is achievable at 15-minute operational timescales with minimal RE curtailment. This RE capacity meets 22% of total projected 2022 electricity consumption in India with annual RE curtailment of 1.4%, in line with experiences in other countries with significant RE penetrations (Bird et al. 2016). Changes to operational practice can further reduce the cost of operating the power system and reduce RE curtailment. Coordinating scheduling and dispatch over a broader area is the largest driver to reduce costs, saving INR 6300 crore (USD 980 million) annually when optimized regionally. Lowering minimum operating levels of coal plants (from 70% to 40%) is the biggest driver to reduce RE curtailment—from 3.5% down to 0.76%. In fact, this operating property is more influential than faster thermal generation ramp rates in lowering the projected levels of curtailment. While this study does not answer every question relevant to planning for India’s 2022 RE targets, it is an important step toward analyzing operational challenges and cost saving opportunities using state-of-the-art power system planning tools. Further analysis can build upon this basis to explore optimal renewable resource and intrastate transmission siting, system stability during contingencies, and the influence of total power system investment costs on customer tariffs.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Palchak, David; Cochran, Jaquelin; Ehlen, Ali
The use of renewable energy (RE) sources, primarily wind and solar generation, is poised to grow significantly within the Indian power system. The Government of India has established a target of 175 gigawatts (GW) of installed RE capacity by 2022, including 60 GW of wind and 100 GW of solar, up from 29 GW wind and 9 GW solar at the beginning of 2017. Thanks to advanced weather and power system modeling made for this project, the study team is able to explore operational impacts of meeting India's RE targets and identify actions that may be favorable for integration. Ourmore » primary tool is a detailed production cost model, which simulates optimal scheduling and dispatch of available generation in a future year (2022) by minimizing total production costs subject to physical, operational, and market constraints. Our team comprises a core group from the Power System Operation Corporation, Ltd. (POSOCO), which is the national grid operator (with representation from the National, Southern, and Western Regional Load Dispatch Centers) under Ministry of Power, National Renewable Energy Laboratory (NREL), and Lawrence Berkeley National Laboratory (LBNL), and a broader modeling team that includes Central Electricity Authority (CEA), POWERGRID (the central transmission utility, CTU), and State Load Dispatch Centers in Maharashtra, Gujarat, Tamil Nadu, Karnataka, Rajasthan, and Andhra Pradesh. Our model includes high-resolution wind and solar data (forecasts and actuals), unique properties for each generator, CEA/CTU's anticipated buildout of the power system, and enforced state-to-state transmission flows. Assuming the fulfillment of current efforts to provide better access to the physical flexibility of the power system, we find that power system balancing with 100 GW of solar and 60 GW of wind is achievable at 15-minute operational timescales with minimal RE curtailment. This RE capacity meets 22% of total projected 2022 electricity consumption in India with annual RE curtailment of 1.4%, in line with experiences in other countries with significant RE penetrations (Bird et al. 2016). Changes to operational practice can further reduce the cost of operating the power system and reduce RE curtailment. Coordinating scheduling and dispatch over a broader area is the largest driver to reduce costs, saving INR 6300 crore (USD $920 million) annually when optimized regionally. Lowering minimum operating levels of coal plants (from 70% to 40%) is the biggest driver to reduce RE curtailment - from 3.5% down to 0.76%. In fact, this operating property is more influential than faster thermal generation ramp rates in lowering the projected levels of curtailment. While this study does not answer every question relevant to planning for India's 2022 RE targets, it is an important step toward analyzing operational challenges and cost saving opportunities using state-of-the-art power system planning tools. Further analysis can build upon this basis to explore optimal renewable resource and intrastate transmission siting, system stability during contingencies, and the influence of total power system investment costs on customer tariffs.« less
Microwaving logs for energy savings and improved paper properties for mechanical pulps
C. Tim Scott; John Klungness; Mike Lentz; Eric Horn; Masood Akhtar
2002-01-01
High-power microwave cooking of commercial black spruce pulpwood logs was investigated as a pretreatment for mechanical pulping. Several dozen logs were treated at a variety of power levels (10 to 50 kW) and for various times (1 to 10 min). The mechanical pulping trials resulted in significant energy savings-up to 15% for the highest power level. In addition, there was...
Hybrid Power Management for Office Equipment
NASA Astrophysics Data System (ADS)
Gingade, Ganesh P.
Office machines (such as printers, scanners, fax, and copiers) can consume significant amounts of power. Few studies have been devoted to power management of office equipment. Most office machines have sleep modes to save power. Power management of these machines are usually timeout-based: a machine sleeps after being idle long enough. Setting the timeout duration can be difficult: if it is too long, the machine wastes power during idleness. If it is too short, the machine sleeps too soon and too often--the wakeup delay can significantly degrade productivity. Thus, power management is a tradeoff between saving energy and keeping short response time. Many power management policies have been published and one policy may outperform another in some scenarios. There is no definite conclusion which policy is always better. This thesis describes two methods for office equipment power management. The first method adaptively reduces power based on a constraint of the wakeup delay. The second method is a hybrid with multiple candidate policies and it selects the most appropriate power management policy. Using six months of request traces from 18 different offices, we demonstrate that the hybrid policy outperforms individual policies. We also discover that power management based on business hours does not produce consistent energy savings.
Energy Aware Cluster-Based Routing in Flying Ad-Hoc Networks.
Aadil, Farhan; Raza, Ali; Khan, Muhammad Fahad; Maqsood, Muazzam; Mehmood, Irfan; Rho, Seungmin
2018-05-03
Flying ad-hoc networks (FANETs) are a very vibrant research area nowadays. They have many military and civil applications. Limited battery energy and the high mobility of micro unmanned aerial vehicles (UAVs) represent their two main problems, i.e., short flight time and inefficient routing. In this paper, we try to address both of these problems by means of efficient clustering. First, we adjust the transmission power of the UAVs by anticipating their operational requirements. Optimal transmission range will have minimum packet loss ratio (PLR) and better link quality, which ultimately save the energy consumed during communication. Second, we use a variant of the K-Means Density clustering algorithm for selection of cluster heads. Optimal cluster heads enhance the cluster lifetime and reduce the routing overhead. The proposed model outperforms the state of the art artificial intelligence techniques such as Ant Colony Optimization-based clustering algorithm and Grey Wolf Optimization-based clustering algorithm. The performance of the proposed algorithm is evaluated in term of number of clusters, cluster building time, cluster lifetime and energy consumption.
Behavior-aware cache hierarchy optimization for low-power multi-core embedded systems
NASA Astrophysics Data System (ADS)
Zhao, Huatao; Luo, Xiao; Zhu, Chen; Watanabe, Takahiro; Zhu, Tianbo
2017-07-01
In modern embedded systems, the increasing number of cores requires efficient cache hierarchies to ensure data throughput, but such cache hierarchies are restricted by their tumid size and interference accesses which leads to both performance degradation and wasted energy. In this paper, we firstly propose a behavior-aware cache hierarchy (BACH) which can optimally allocate the multi-level cache resources to many cores and highly improved the efficiency of cache hierarchy, resulting in low energy consumption. The BACH takes full advantage of the explored application behaviors and runtime cache resource demands as the cache allocation bases, so that we can optimally configure the cache hierarchy to meet the runtime demand. The BACH was implemented on the GEM5 simulator. The experimental results show that energy consumption of a three-level cache hierarchy can be saved from 5.29% up to 27.94% compared with other key approaches while the performance of the multi-core system even has a slight improvement counting in hardware overhead.
Numerical simulation and optimization of red mud separation thickener with self-dilute feed
Zhou, Tian; Li, Mao; Zhou, Chenn-qian; ...
2014-03-01
In order to acquire the flow pattern and investigate the settling behavior of the red mud in the separation thickener, computational fluid dynamics (CFD), custom subroutines and agglomerates settling theory were employed to simulate the three-dimensional flow field in an industrial scale thickener with the introduction of a self-dilute feed system. Our simulation results show good agreement with the measurement onsite and the flow patterns of the thickener are presented and discussed on both velocity and concentration field. Optimization experiments on feed well and self-dilute system were also carried out, and indicate that the optimal thickener system can dilute themore » solid concentration in feed well from 110 g/L to 86 g/L which would help the agglomerates’ formation and improve the red mud settling speed. The additional power of recirculation pump can be saved and flocculants dosage was reduced from 105g/t to 85g/t in the operation.« less
Optimizing the temporal dynamics of light to human perception.
Rieiro, Hector; Martinez-Conde, Susana; Danielson, Andrew P; Pardo-Vazquez, Jose L; Srivastava, Nishit; Macknik, Stephen L
2012-11-27
No previous research has tuned the temporal characteristics of light-emitting devices to enhance brightness perception in human vision, despite the potential for significant power savings. The role of stimulus duration on perceived contrast is unclear, due to contradiction between the models proposed by Bloch and by Broca and Sulzer over 100 years ago. We propose that the discrepancy is accounted for by the observer's "inherent expertise bias," a type of experimental bias in which the observer's life-long experience with interpreting the sensory world overcomes perceptual ambiguities and biases experimental outcomes. By controlling for this and all other known biases, we show that perceived contrast peaks at durations of 50-100 ms, and we conclude that the Broca-Sulzer effect best describes human temporal vision. We also show that the plateau in perceived brightness with stimulus duration, described by Bloch's law, is a previously uncharacterized type of temporal brightness constancy that, like classical constancy effects, serves to enhance object recognition across varied lighting conditions in natural vision-although this is a constancy effect that normalizes perception across temporal modulation conditions. A practical outcome of this study is that tuning light-emitting devices to match the temporal dynamics of the human visual system's temporal response function will result in significant power savings.
Clustering-based energy-saving algorithm in ultra-dense network
NASA Astrophysics Data System (ADS)
Huang, Junwei; Zhou, Pengguang; Teng, Deyang; Zhang, Renchi; Xu, Hao
2017-06-01
In Ultra-dense Networks (UDN), dense deployment of low power small base stations will cause serious small cells interference and a large amount of energy consumption. The purpose of this paper is to explore the method of reducing small cells interference and energy saving system in UDN, and we innovatively propose a sleep-waking-active (SWA) scheme. The scheme decreases the user outage causing by failure to detect users’ service requests, shortens the opening time of active base stations directly switching to sleep mode; we further proposes a Vertex Surrounding Clustering(VSC) algorithm, which first colours the small cells with the most strongest interference and next extends to the adjacent small cells. VSC algorithm can use the least colour to stain the small cell, reduce the number of iterations and promote the efficiency of colouring. The simulation results show that SWA scheme can effectively improve the system Energy Efficiency (EE), the VSC algorithm can reduce the small cells interference and optimize the users’ Spectrum Efficiency (SE) and throughput.
Exploring efficacy of residential energy efficiency programs in Florida
NASA Astrophysics Data System (ADS)
Taylor, Nicholas Wade
Electric utilities, government agencies, and private interests in the U.S. have committed and continue to invest substantial resources in the pursuit of energy efficiency and conservation through demand-side management (DSM) programs. Program investments, and the demand for impact evaluations that accompany them, are projected to grow in coming years due to increased pressure from state-level energy regulation, costs and challenges of building additional production capacity, fuel costs and potential carbon or renewable energy regulation. This dissertation provides detailed analyses of ex-post energy savings from energy efficiency programs in three key sectors of residential buildings: new, single-family, detached homes; retrofits to existing single-family, detached homes; and retrofits to existing multifamily housing units. Each of the energy efficiency programs analyzed resulted in statistically significant energy savings at the full program group level, yet savings for individual participants and participant subgroups were highly variable. Even though savings estimates were statistically greater than zero, those energy savings did not always meet expectations. Results also show that high variability in energy savings among participant groups or subgroups can negatively impact overall program performance and can undermine marketing efforts for future participation. Design, implementation, and continued support of conservation programs based solely on deemed or projected savings is inherently counter to the pursuit of meaningful energy conservation and reductions in greenhouse gas emissions. To fully understand and optimize program impacts, consistent and robust measurement and verification protocols must be instituted in the design phase and maintained over time. Furthermore, marketing for program participation must target those who have the greatest opportunity for savings. In most utility territories it is not possible to gain access to the type of large scale datasets that would facilitate robust program analysis. Along with measuring and optimizing energy conservation programs, utilities should provide public access to historical consumption data. Open access to data, program optimization, consistent measurement and verification and transparency in reported savings are essential to reducing energy use and its associated environmental impacts.
NASA Astrophysics Data System (ADS)
Cao, Ling; Che, Wenbin
2018-05-01
For the central air-conditioning energy-saving, it is common practice to use a wide range of PTD controllers in engineering to optimize energy savings. However, the shortcomings of the PTD controller have also been magnified on this issue, such as: calculation accuracy is not enough, the calculation time is too long. Particle swarm optimization has the advantage of fast convergence. This paper is based on Particle Swarm Optimization apply in PTD controller tuning parameters in order to achieve the purpose of saving energy while ensuring comfort. The algorithm proposed in this paper can adjust the weight according to the change of population fitness, reduce the weights of particles with lower fitness and enhance the weights of particles with higher fitness in the population, and fully release the population vitality. The method in this paper is validated by the TRNSYS model based on the central air-conditioning system. The experimental results show that the room temperature fluctuation is small, the overshoot is small, the adjustment speed is fast, and the energy-saving fluctuates at 10%.
OpenADR Specification to Ease Saving Power in Buildings
None
2017-12-09
A new data model developed by researchers at the Department of Energys Lawrence Berkeley National Laboratory and their colleagues at other universities and in the private sector will help facilities and buildings save power through automated demand response technology, and advance the development of the Smart Grid.
USDA and Florida Power & Light Company Successfully Save $85K/year with UESC Collaboration
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Case study features the U.S. Department of Agriculture's (USDA) Miami Subtropical Horticulture Research Station, which was in need of several energy upgrades. USDA teamed up with Florida Light & Power to install much needed facility improvements are creating a savings of $85,000 per year.
Thermally-Constrained Fuel-Optimal ISS Maneuvers
NASA Technical Reports Server (NTRS)
Bhatt, Sagar; Svecz, Andrew; Alaniz, Abran; Jang, Jiann-Woei; Nguyen, Louis; Spanos, Pol
2015-01-01
Optimal Propellant Maneuvers (OPMs) are now being used to rotate the International Space Station (ISS) and have saved hundreds of kilograms of propellant over the last two years. The savings are achieved by commanding the ISS to follow a pre-planned attitude trajectory optimized to take advantage of environmental torques. The trajectory is obtained by solving an optimal control problem. Prior to use on orbit, OPM trajectories are screened to ensure a static sun vector (SSV) does not occur during the maneuver. The SSV is an indicator that the ISS hardware temperatures may exceed thermal limits, causing damage to the components. In this paper, thermally-constrained fuel-optimal trajectories are presented that avoid an SSV and can be used throughout the year while still reducing propellant consumption significantly.
Is Passive or Active House Needed In Face of Global Warming?
NASA Astrophysics Data System (ADS)
Tamosaitis, Romualdas
2017-10-01
The article aims to determine how effective the stricter current requirements for the building envelope insolation are from the economic energy savings perspective. The article deals with a mathematical method for economic assessment of optimal building thermal insulation. The mathematical methods used in this article are based on evaluating the break-even point between the construction expenditures and the economic profit. Recent research shows that energy savings achieved solely through stricter standards applied to the building envelopes are limited in their ability to achieve maximum results. As the ratio of building volume to building envelope increases, further energy saving measures applied to the building envelope produce lower energy saving effects. Energy savings achieved using renewable energy resources, recuperation systems are much more effective. Research shows that much greater effect can be achieved by combining optimal building envelope energy efficiency measures with new requirements related to renewable energy sources and recuperating systems, such as solar batteries, wind turbines or heat pumps.
Ultra-low-power wearable biopotential sensor nodes.
Yazicioglu, R F; Torfs, T; Penders, J; Romero, I; Kim, H; Merken, P; Gyselinckx, B; Yoo, H J; Van Hoof, C
2009-01-01
This paper discusses ultra-low-power wireless sensor nodes intended for wearable biopotential monitoring. Specific attention is given to mixed-signal design approaches and their impact on the overall system power dissipation. Examples of trade-offs in power dissipation between analog front-ends and digital signal processing are also given. It is shown how signal filtering can further reduce the internal power consumption of a node. Such power saving approaches are indispensable as real-life tests of custom wireless ECG patches reveal the need for artifact detection and correction. The power consumption of such additional features has to come from power savings elsewhere in the system as the overall power budget cannot increase.
Marginal costs of water savings from cooling system retrofits: a case study for Texas power plants
NASA Astrophysics Data System (ADS)
Loew, Aviva; Jaramillo, Paulina; Zhai, Haibo
2016-10-01
The water demands of power plant cooling systems may strain water supply and make power generation vulnerable to water scarcity. Cooling systems range in their rates of water use, capital investment, and annual costs. Using Texas as a case study, we examined the cost of retrofitting existing coal and natural gas combined-cycle (NGCC) power plants with alternative cooling systems, either wet recirculating towers or air-cooled condensers for dry cooling. We applied a power plant assessment tool to model existing power plants in terms of their key plant attributes and site-specific meteorological conditions and then estimated operation characteristics of retrofitted plants and retrofit costs. We determined the anticipated annual reductions in water withdrawals and the cost-per-gallon of water saved by retrofits in both deterministic and probabilistic forms. The results demonstrate that replacing once-through cooling at coal-fired power plants with wet recirculating towers has the lowest cost per reduced water withdrawals, on average. The average marginal cost of water withdrawal savings for dry-cooling retrofits at coal-fired plants is approximately 0.68 cents per gallon, while the marginal recirculating retrofit cost is 0.008 cents per gallon. For NGCC plants, the average marginal costs of water withdrawal savings for dry-cooling and recirculating towers are 1.78 and 0.037 cents per gallon, respectively.
Kouchri, Farrokh Mohammadzadeh
2012-11-06
A Voice over Internet Protocol (VoIP) communications system, a method of managing a communications network in such a system and a program product therefore. The system/network includes an ENERGY STAR (E-star) aware softswitch and E-star compliant communications devices at system endpoints. The E-star aware softswitch allows E-star compliant communications devices to enter and remain in power saving mode. The E-star aware softswitch spools messages and forwards only selected messages (e.g., calls) to the devices in power saving mode. When the E-star compliant communications devices exit power saving mode, the E-star aware softswitch forwards spooled messages.
Design optimization of aircraft landing gear assembly under dynamic loading
NASA Astrophysics Data System (ADS)
Wong, Jonathan Y. B.
As development cycles and prototyping iterations begin to decrease in the aerospace industry, it is important to develop and improve practical methodologies to meet all design metrics. This research presents an efficient methodology that applies high-fidelity multi-disciplinary design optimization techniques to commercial landing gear assemblies, for weight reduction, cost savings, and structural performance dynamic loading. Specifically, a slave link subassembly was selected as the candidate to explore the feasibility of this methodology. The design optimization process utilized in this research was sectioned into three main stages: setup, optimization, and redesign. The first stage involved the creation and characterization of the models used throughout this research. The slave link assembly was modelled with a simplified landing gear test, replicating the behavior of the physical system. Through extensive review of the literature and collaboration with Safran Landing Systems, dynamic and structural behavior for the system were characterized and defined mathematically. Once defined, the characterized behaviors for the slave link assembly were then used to conduct a Multi-Body Dynamic (MBD) analysis to determine the dynamic and structural response of the system. These responses were then utilized in a topology optimization through the use of the Equivalent Static Load Method (ESLM). The results of the optimization were interpreted and later used to generate improved designs in terms of weight, cost, and structural performance under dynamic loading in stage three. The optimized designs were then validated using the model created for the MBD analysis of the baseline design. The design generation process employed two different approaches for post-processing the topology results produced. The first approach implemented a close replication of the topology results, resulting in a design with an overall peak stress increase of 74%, weight savings of 67%, and no apparent cost savings due to complex features present in the design. The second design approach focused on realizing reciprocating benefits for cost and weight savings. As a result, this design was able to achieve an overall peak stress increase of 6%, weight and cost savings of 36%, and 60%, respectively.
NASA Astrophysics Data System (ADS)
Kwon, Hyuk Ju; Yeon, Sang Hun; Lee, Keum Ho; Lee, Kwang Ho
2018-02-01
As various studies focusing on building energy saving have been continuously conducted, studies utilizing renewable energy sources, instead of fossil fuel, are needed. In particular, studies regarding solar energy are being carried out in the field of building science; in order to utilize such solar energy effectively, solar radiation being brought into the indoors should be acquired and blocked properly. Blinds are a typical solar radiation control device that is capable of controlling indoor thermal and light environments. However, slat-type blinds are manually controlled, giving a negative effect on building energy saving. In this regard, studies regarding the automatic control of slat-type blinds have been carried out for the last couple of decades. Therefore, this study aims to provide preliminary data for optimal control research through the controlling of slat angle in slat-type blinds by comprehensively considering various input variables. The window area ratio and orientation were selected as input variables. It was found that an optimal control algorithm was different among each window-to-wall ratio and window orientation. In addition, through comparing and analyzing the building energy saving performance for each condition by applying the developed algorithms to simulations, up to 20.7 % energy saving was shown in the cooling period and up to 12.3 % energy saving was shown in the heating period. In addition, building energy saving effect was greater as the window area ratio increased given the same orientation, and the effects of window-to-wall ratio in the cooling period were higher than those of window-to-wall ratio in the heating period.
Effects of frequency on gross efficiency and performance in roller ski skating.
Leirdal, S; Sandbakk, O; Ettema, G
2013-06-01
The purpose of the present study was to examine the effect of frequency on efficiency and performance during G3 roller ski skating. Eight well-trained male cross-country skiers performed three submaximal 5-min speeds (10, 13, and 16 km/h) and a time-to-exhaustion (TTE) performance (at 20 km/h) using the G3 skating technique using freely chosen, high, and low frequency at all four speeds. All tests were done using roller skis on a large treadmill at 5% incline. Gross efficiency (GE) was calculated as power divided by metabolic rate. Power was calculated as the sum of power against frictional forces and power against gravity. Metabolic rate was calculated from oxygen consumption and blood lactate concentration. Freely chosen frequency increased from 60 to 70 strokes/min as speed increased from 10 to 20 km/h. GE increased with power. At high power (20 km/h performance test), both efficiency and performance were significantly reduced by high frequency. In regard to choice of frequency during G3 roller ski skating, cross-country skiers seems to be self-optimized both in relation to energy saving (efficiency) and performance (TTE). © 2011 John Wiley & Sons A/S.
Computational tool for simulation of power and refrigeration cycles
NASA Astrophysics Data System (ADS)
Córdoba Tuta, E.; Reyes Orozco, M.
2016-07-01
Small improvement in thermal efficiency of power cycles brings huge cost savings in the production of electricity, for that reason have a tool for simulation of power cycles allows modeling the optimal changes for a best performance. There is also a big boom in research Organic Rankine Cycle (ORC), which aims to get electricity at low power through cogeneration, in which the working fluid is usually a refrigerant. A tool to design the elements of an ORC cycle and the selection of the working fluid would be helpful, because sources of heat from cogeneration are very different and in each case would be a custom design. In this work the development of a multiplatform software for the simulation of power cycles and refrigeration, which was implemented in the C ++ language and includes a graphical interface which was developed using multiplatform environment Qt and runs on operating systems Windows and Linux. The tool allows the design of custom power cycles, selection the type of fluid (thermodynamic properties are calculated through CoolProp library), calculate the plant efficiency, identify the fractions of flow in each branch and finally generates a report very educational in pdf format via the LaTeX tool.
Multi level optimization of burnable poison utilization for advanced PWR fuel management
NASA Astrophysics Data System (ADS)
Yilmaz, Serkan
The objective of this study was to develop an unique methodology and a practical tool for designing burnable poison (BP) pattern for a given PWR core. Two techniques were studied in developing this tool. First, the deterministic technique called Modified Power Shape Forced Diffusion (MPSFD) method followed by a fine tuning algorithm, based on some heuristic rules, was developed to achieve this goal. Second, an efficient and a practical genetic algorithm (GA) tool was developed and applied successfully to Burnable Poisons (BPs) placement optimization problem for a reference Three Mile Island-1 (TMI-1) core. This thesis presents the step by step progress in developing such a tool. The developed deterministic method appeared to perform as expected. The GA technique produced excellent BP designs. It was discovered that the Beginning of Cycle (BOC) Kinf of a BP fuel assembly (FA) design is a good filter to eliminate invalid BP designs created during the optimization process. By eliminating all BP designs having BOC Kinf above a set limit, the computational time was greatly reduced since the evaluation process with reactor physics calculations for an invalid solution is canceled. Moreover, the GA was applied to develop the BP loading pattern to minimize the total Gadolinium (Gd) amount in the core together with the residual binding at End-of-Cycle (EOC) and to keep the maximum peak pin power during core depletion and Soluble boron concentration at BOC both less than their limit values. The number of UO2/Gd2O3 pins and Gd 2O3 concentrations for each fresh fuel location in the core are the decision variables and the total amount of the Gd in the core and maximum peak pin power during core depletion are in the fitness functions. The use of different fitness function definition and forcing the solution movement towards to desired region in the solution space accelerated the GA runs. Special emphasize is given to minimizing the residual binding to increase core lifetime as well as minimizing the total Gd amount in the core. The GA code developed many good solutions that satisfy all of the design constraints. For these solutions, the EOC soluble boron concentration changes from 68.9 to 97.2 ppm. It is important to note that the difference of 28.3 ppm between the best and the worst solution in the good solutions region represent the potential of 12.5 Effective-Full-Power-Day (EPFD) savings in cycle length. As a comparison, the best BP loading design has 97.2 ppm soluble boron concentration at EOC while the BP loading with available vendors' U/Gd FA designs has 94.4 ppm SOB at EOC. It was estimated that the difference of 2.8 ppm reflected the potential savings of 1.25 EFPD in cycle length. Moreover, the total Gd amount was reduced by 6.89% in mass that provided extra savings in fuel cost compared to the BP loading pattern with available vendor's U/Gd FA designs. (Abstract shortened by UMI.)
Power-Factor Controllers: How Safe?
NASA Technical Reports Server (NTRS)
Long, K.; Christian, W.; Kovacik, J.; Grazyk, T.
1985-01-01
Potential safety problems with power-factor controllers (PFC's) evaluated. Based on study of PFCs in use with appliances, report recommends measures to prevent consumers from misapplying these energy saving devices. Device used on such appliances as refrigerators, sewing machines, pumps, hair dryers, and food processors. When misused, they fail to save energy and may cause damage.
NASA Astrophysics Data System (ADS)
Yuan, Jindou; Xu, Jinliang; Wang, Yaodong
2018-03-01
Energy saving and emission reduction have become targets for modern society due to the potential energy crisis and the threat of climate change. A distributed hybrid renewable energy system (HRES) consists of photovoltaic (PV) arrays, a wood-syngas combined heat and power generator (CHP) and back-up batteries is designed to power a typical semi-detached rural house in China which aims to meet the energy demand of a house and to reduce greenhouse gas emissions from the use of fossil fuels. Based on the annual load information of the house and the local meteorological data including solar radiation, air temperature, etc., a system model is set up using HOMER software and is used to simulate all practical configurations to carry out technical and economic evaluations. The performance of the whole HRES system and each component under different configurations are evaluated. The optimized configuration of the system is found
NASA Astrophysics Data System (ADS)
Dinzi, R.; Hamonangan, TS; Fahmi, F.
2018-02-01
In the current distribution system, a large-capacity distribution transformer supplies loads to remote locations. The use of 220/380 V network is nowadays less common compared to 20 kV network. This results in losses due to the non-optimal distribution transformer, which neglected the load location, poor consumer profile, and large power losses along the carrier. This paper discusses how high voltage distribution systems (HVDS) can be a better system used in distribution networks than the currently used distribution system (Low Voltage Distribution System, LVDS). The proposed change of the system into the new configuration is done by replacing a large-capacity distribution transformer with some smaller-capacity distribution transformers and installed them in positions that closest to the load. The use of high voltage distribution systems will result in better voltage profiles and fewer power losses. From the non-technical side, the annual savings and payback periods on high voltage distribution systems will also be the advantage.
Advanced Integrated Power and Attitude Control System (IPACS) study
NASA Technical Reports Server (NTRS)
Oglevie, R. E.; Eisenhaure, D. B.
1985-01-01
Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of simultaneously satisfying the demands of energy storage and attitude control through the use of rotating flywheels. It was demonstrated that, for a wide spectrum of applications, such a system possessed many advantages over contemporary energy storage and attitude control approaches. More recent technology advances in composite material rotors, magnetic suspension systems, and power control electronics have triggered new optimism regarding the applicability and merits of this concept. This study is undertaken to define an advanced IPACS and to evaluate its merits for a space station application. System and component designs are developed to establish the performance of this concept and system trade studies conducted to examine the viability of this approach relative to conventional candidate systems. It is clearly demonstrated that an advanced IPACS concept is not only feasible, but also offers substantial savings in mass and life-cycle cost for the space station mission.
Integrated Power and Attitude Control Systems for Space Station
NASA Technical Reports Server (NTRS)
Oglevie, R. E.; Eisenhaure, D. B.
1985-01-01
Integrated Power and Attitude Control Systems (IPACS) studies performed over a decade ago established the feasibility of simultaneously storing electrical energy in wheels and utilizing the resulting momentum for spacecraft attitude control. It was shown that such a system possessed many advantages over other contemporary energy storage and attitude control systems in many applications. More recent technology advances in composite rotors, magnetic bearings, and power control electronics have triggered new optimism regarding the feasibility and merits of such a system. The paper presents the results of a recent study whose focus was to define an advanced IPACS and to evaluate its merits for the Space Station application. A system and component design concept is developed to establish the system performance capability. A system level trade study, including life-cycle costing, is performed to define the merits of the system relative to two other candidate systems. It is concluded that an advanced IPACS concept is not only feasible, but offers substantial savings in mass, and life-cycle cost.
NASA Astrophysics Data System (ADS)
Pavlak, Gregory S.
Building energy use is a significant contributing factor to growing worldwide energy demands. In pursuit of a sustainable energy future, commercial building operations must be intelligently integrated with the electric system to increase efficiency and enable renewable generation. Toward this end, a model-based methodology was developed to estimate the capability of commercial buildings to participate in frequency regulation ancillary service markets. This methodology was integrated into a supervisory model predictive controller to optimize building operation in consideration of energy prices, demand charges, and ancillary service revenue. The supervisory control problem was extended to building portfolios to evaluate opportunities for synergistic effect among multiple, centrally-optimized buildings. Simulation studies performed showed that the multi-market optimization was able to determine appropriate opportunities for buildings to provide frequency regulation. Total savings were increased by up to thirteen percentage points, depending on the simulation case. Furthermore, optimizing buildings as a portfolio achieved up to seven additional percentage points of savings, depending on the case. Enhanced energy and cost savings opportunities were observed by taking the novel perspective of optimizing building portfolios in multiple grid markets, motivating future pursuits of advanced control paradigms that enable a more intelligent electric grid.
NASA Technical Reports Server (NTRS)
2009-01-01
Topics covered include: Image-Capture Devices Extend Medicine's Reach; Medical Devices Assess, Treat Balance Disorders; NASA Bioreactors Advance Disease Treatments; Robotics Algorithms Provide Nutritional Guidelines; "Anti-Gravity" Treadmills Speed Rehabilitation; Crew Management Processes Revitalize Patient Care; Hubble Systems Optimize Hospital Schedules; Web-based Programs Assess Cognitive Fitness; Electrolyte Concentrates Treat Dehydration; Tools Lighten Designs, Maintain Structural Integrity; Insulating Foams Save Money, Increase Safety; Polyimide Resins Resist Extreme Temperatures; Sensors Locate Radio Interference; Surface Operations Systems Improve Airport Efficiency; Nontoxic Resins Advance Aerospace Manufacturing; Sensors Provide Early Warning of Biological Threats; Robot Saves Soldier's Lives Overseas (MarcBot); Apollo-Era Life Raft Saves Hundreds of Sailors; Circuits Enhance Scientific Instruments and Safety Devices; Tough Textiles Protect Payloads and Public Safety Officers; Forecasting Tools Point to Fishing Hotspots; Air Purifiers Eliminate Pathogens, Preserve Food; Fabrics Protect Sensitive Skin from UV Rays; Phase Change Fabrics Control Temperature; Tiny Devices Project Sharp, Colorful Images; Star-Mapping Tools Enable Tracking of Endangered Animals; Nanofiber Filters Eliminate Contaminants; Modeling Innovations Advance Wind Energy Industry; Thermal Insulation Strips Conserve Energy; Satellite Respondent Buoys Identify Ocean Debris; Mobile Instruments Measure Atmospheric Pollutants; Cloud Imagers Offer New Details on Earth's Health; Antennas Lower Cost of Satellite Access; Feature Detection Systems Enhance Satellite Imagery; Chlorophyll Meters Aid Plant Nutrient Management; Telemetry Boards Interpret Rocket, Airplane Engine Data; Programs Automate Complex Operations Monitoring; Software Tools Streamline Project Management; Modeling Languages Refine Vehicle Design; Radio Relays Improve Wireless Products; Advanced Sensors Boost Optical Communication, Imaging; Tensile Fabrics Enhance Architecture Around the World; Robust Light Filters Support Powerful Imaging Devices; Thermoelectric Devices Cool, Power Electronics; Innovative Tools Advance Revolutionary Weld Technique; Methods Reduce Cost, Enhance Quality of Nanotubes; Gauging Systems Monitor Cryogenic Liquids; Voltage Sensors Monitor Harmful Static; and Compact Instruments Measure Heat Potential.
Multi-mode multi-band power amplifier module with high low-power efficiency
NASA Astrophysics Data System (ADS)
Xuguang, Zhang; Jie, Jin
2015-10-01
Increasingly, mobile communications standards require high power efficiency and low currents in the low power mode. This paper proposes a fully-integrated multi-mode and multi-band power amplifier module (PAM) to meet these requirements. A dual-path PAM is designed for high-power mode (HPM), medium-power mode (MPM), and low-power mode (LPM) operations without any series switches for different mode selection. Good performance and significant current saving can be achieved by using an optimized load impedance design for each power mode. The PAM is tapeout with the InGaP/GaAs heterojunction bipolar transistor (HBT) process and the 0.18-μm complementary metal-oxide semiconductor (CMOS) process. The test results show that the PAM achieves a very low quiescent current of 3 mA in LPM. Meanwhile, across the 1.7-2.0 GHz frequency, the PAM performs well. In HPM, the output power is 28 dBm with at least 39.4% PAE and -40 dBc adjacent channel leakage ratio 1 (ACLR1). In MPM, the output power is 17 dBm, with at least 21.3% PAE and -43 dBc ACLR1. In LPM, the output power is 8 dBm, with at least 18.2% PAE and -40 dBc ACLR1. Project supported by the National Natural Science Foundation of China (No. 61201244).
NASA Astrophysics Data System (ADS)
Pak, Pyong Sik
This paper evaluates two proposed repowering systems together with a conventional repowering system. A power generation system utilizing waste heat produced by a garbage incineration plant (GIP), which treats 45 t/d of garbage, was taken as an objective power generation system to be repowered. As the conventional repowering system (Sys-C), a gas turbine system with waste heat boiler was adopted. In the proposed system 1 (Sys-P1), temperature of the low temperature steam generated at the GIP is raised in the gas combustor by burning fuel, and used to drive a gas turbine generator. Hence, required power for compressing the air becomes remarkably small and expected to be high efficient compared with Sys-C. In the proposed system 2 (Sys-P2), the low temperature steam generated at the GIP is superheated by using regenerative burner and used to drive a steam turbine generator, and hence making steam condition optimal becomes easy. Various basic characteristics of the three repowering systems were estimated through computer simulation, such as repowering efficiency, energy saving characteristics, and amount of CO2 reduction. It was shown that Sys-P1 and Sys-P2 were both superior to the conventional repowering system Sys-C in the all characteristics, and Sys-P1 to Sys-P2 in repowering efficiency, and that Sys-P2 to Sys-P1 in energy saving characteristics and CO2 reduction effect. It has also been estimated that all the repowering systems are economically feasible, and that the proposed systems Sys-P1 and Sys-P2 are both superior to the Sys-C in the three economical indices of unit cost of power, annual gross profit and depreciation year.
NASA Astrophysics Data System (ADS)
Lange, Christoph; Hülsermann, Ralf; Kosiankowski, Dirk; Geilhardt, Frank; Gladisch, Andreas
2010-01-01
The increasing demand for higher bit rates in access networks requires fiber deployment closer to the subscriber resulting in fiber-to-the-home (FTTH) access networks. Besides higher access bit rates optical access network infrastructure and related technologies enable the network operator to establish larger service areas resulting in a simplified network structure with a lower number of network nodes. By changing the network structure network operators want to benefit from a changed network cost structure by decreasing in short and mid term the upfront investments for network equipment due to concentration effects as well as by reducing the energy costs due to a higher energy efficiency of large network sites housing a high amount of network equipment. In long term also savings in operational expenditures (OpEx) due to the closing of central office (CO) sites are expected. In this paper different architectures for optical access networks basing on state-of-the-art technology are analyzed with respect to network installation costs and power consumption in the context of access node consolidation. Network planning and dimensioning results are calculated for a realistic network scenario of Germany. All node consolidation scenarios are compared against a gigabit capable passive optical network (GPON) based FTTH access network operated from the conventional CO sites. The results show that a moderate reduction of the number of access nodes may be beneficial since in that case the capital expenditures (CapEx) do not rise extraordinarily and savings in OpEx related to the access nodes are expected. The total power consumption does not change significantly with decreasing number of access nodes but clustering effects enable a more energyefficient network operation and optimized power purchase order quantities leading to benefits in energy costs.
Minimization of Roll Firings for Optimal Propellant Maneuvers
NASA Astrophysics Data System (ADS)
Leach, Parker C.
Attitude control of the International Space Station (ISS) is critical for operations, impacting power, communications, and thermal systems. The station uses gyroscopes and thrusters for attitude control, and reorientations are normally assisted by thrusters on docked vehicles. When the docked vehicles are unavailable, the reduction in control authority in the roll axis results in frequent jet firings and massive fuel consumption. To improve this situation, new guidance and control schemes are desired that provide control with fewer roll firings. Optimal control software was utilized to solve for potential candidates that satisfied desired conditions with the goal of minimizing total propellant. An ISS simulation too was then used to test these solutions for feasibility. After several problem reformulations, multiple candidate solutions minimizing or completely eliminating roll firings were found. Flight implementation would not only save massive amounts of fuel and thus money, but also reduce ISS wear and tear, thereby extending its lifetime.
NASA Astrophysics Data System (ADS)
Kang, Donghun; Lee, Jungeon; Jung, Jongpil; Lee, Chul-Hee; Kyung, Chong-Min
2014-09-01
In mobile video systems powered by battery, reducing the encoder's compression energy consumption is critical to prolong its lifetime. Previous Energy-rate-distortion (E-R-D) optimization methods based on a software codec is not suitable for practical mobile camera systems because the energy consumption is too large and encoding rate is too low. In this paper, we propose an E-R-D model for the hardware codec based on the gate-level simulation framework to measure the switching activity and the energy consumption. From the proposed E-R-D model, an energy minimizing algorithm for mobile video camera sensor have been developed with the GOP (Group of Pictures) size and QP(Quantization Parameter) as run-time control variables. Our experimental results show that the proposed algorithm provides up to 31.76% of energy consumption saving while satisfying the rate and distortion constraints.
Measured effects of wind turbine generation at the Block Island Power Company
NASA Technical Reports Server (NTRS)
Wilreker, V. F.; Smith, R. F.; Stiller, P. H.; Scot, G. W.; Shaltens, R. K.
1984-01-01
Data measurements made on the NASA MOD-OA 200-kw wind-turbine generator (WTG) installed on a utility grid form the basis for an overall performance analysis. Fuel displacement/-savings, dynamic interactions, and WTG excitation (reactive-power) control effects are studied. Continuous recording of a large number of electrical and mechanical variables on FM magnetic tape permit evaluation and correlation of phenomena over a bandwidth of at least 20 Hz. Because the wind-power penetration reached peaks of 60 percent, the impact of wind fluctuation and wind-turbine/diesel-utility interaction is evaluated in a worst-case scenario. The speed-governor dynamics of the diesel units exhibited an underdamped response, and the utility operation procedures were not altered to optimize overall WTG/utility performance. Primary findings over the data collection period are: a calculated 6.7-percent reduction in fuel consumption while generating 11 percent of the total electrical energy; acceptable system voltage and frequency fluctuations with WTG connected; and applicability of WTG excitation schemes using voltage, power, or VARS as the controlled variable.
NASA Astrophysics Data System (ADS)
Tang, Dunbing; Dai, Min
2015-09-01
The traditional production planning and scheduling problems consider performance indicators like time, cost and quality as optimization objectives in manufacturing processes. However, environmentally-friendly factors like energy consumption of production have not been completely taken into consideration. Against this background, this paper addresses an approach to modify a given schedule generated by a production planning and scheduling system in a job shop floor, where machine tools can work at different cutting speeds. It can adjust the cutting speeds of the operations while keeping the original assignment and processing sequence of operations of each job fixed in order to obtain energy savings. First, the proposed approach, based on a mixed integer programming mathematical model, changes the total idle time of the given schedule to minimize energy consumption in the job shop floor while accepting the optimal solution of the scheduling objective, makespan. Then, a genetic-simulated annealing algorithm is used to explore the optimal solution due to the fact that the problem is strongly NP-hard. Finally, the effectiveness of the approach is performed smalland large-size instances, respectively. The experimental results show that the approach can save 5%-10% of the average energy consumption while accepting the optimal solution of the makespan in small-size instances. In addition, the average maximum energy saving ratio can reach to 13%. And it can save approximately 1%-4% of the average energy consumption and approximately 2.4% of the average maximum energy while accepting the near-optimal solution of the makespan in large-size instances. The proposed research provides an interesting point to explore an energy-aware schedule optimization for a traditional production planning and scheduling problem.
Central Plant Optimization for Waste Energy Reduction (CPOWER). ESTCP Cost and Performance Report
2016-12-01
in the regression models. The solar radiation data did not appear reliable in the weather dataset for the location, and hence it was not used. The...and additional factors (e.g., solar insolation) may be needed to obtain a better model. 2. Inputs to optimizer: During several periods of...Location: North Carolina Energy Consumption Cost Savings $ 443,698.00 Analysis Type: FEMP PV of total savings 215,698.00$ Base Date: April 1
Saving Energy and Money: A Lesson in Computer Power Management
ERIC Educational Resources Information Center
Lazaros, Edward J.; Hua, David
2012-01-01
In this activity, students will develop an understanding of the economic impact of technology by estimating the cost savings of power management strategies in the classroom. Students will learn how to adjust computer display settings to influence the impact that the computer has on the financial burden to the school. They will use mathematics to…
OpenADR Specification to Ease Saving Power in Buildings
Piette, Mary Ann
2017-12-09
A new data model developed by researchers at the Department of Energys Lawrence Berkeley National Laboratory and their colleagues at other universities and in the private sector will help facilities and buildings save power through automated demand response technology, and advance the development of the Smart Grid. http://newscenter.lbl.gov/press-releases/2009/04/27/openadr-specification/
2011-01-01
we propose that hot-spot mitigation using thermoelectric coolers can be used as a power management mechanism to allow global coolers to be provi...sioned for a better worst case temperature leading to substan- tial savings in cooling power. In order to quantify the potential power savings from us- ing...energy density inside a processor to maximally tolerable levels, modern microprocessors make ex- tensive use of hardware structures such as the load
Field testing energy-saving hermetic compressors in residential refrigerators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sauber, R.S.; Middleton, M.G.
The design of an energy-saving compressor for low back pressure applications is reviewed. Calorimeter performance results are stated for two sizes of the efficient design and compared with performance test results for a standard compressor. Power consumption of a refrigerator-freezer is given with a standard compressor and with the energy-saving compressor. The preparation of the refrigerators used in the field test is discussed, along with the criteria used in selecting the instrumentation for the project. Results of the energy-saving compressor in the field test, along with a comparison to a standard production compressor, are presented. Some conclusions are drawn, basedmore » on the data, in relation to important factors in residential refrigerator power consumption.« less
Field testing energy-saving hermetic compressors in residential refrigerators
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sauber, R.S.; Middleton, M.G.
The design of an energy saving compressor for low back pressure applications is reviewed. Calorimeter performance results are stated for two sizes of the efficient design and compared with performance test results for a standard compressor. Power consumption of a refrigerator-freezer is given with a standard compressor and with the energy saving compressor. The preparation of the refrigerators used in the field test are discussed along with the criteria used in selecting the instrumentation for the project. Results of the energy saving compressor in the field test along with a comparison to a standard production compressor are presented. Some conclusionsmore » are drawn, based on the data, in relation to important factors in residential refrigerator power consumption.« less
Cache Energy Optimization Techniques For Modern Processors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mittal, Sparsh
2013-01-01
Modern multicore processors are employing large last-level caches, for example Intel's E7-8800 processor uses 24MB L3 cache. Further, with each CMOS technology generation, leakage energy has been dramatically increasing and hence, leakage energy is expected to become a major source of energy dissipation, especially in last-level caches (LLCs). The conventional schemes of cache energy saving either aim at saving dynamic energy or are based on properties specific to first-level caches, and thus these schemes have limited utility for last-level caches. Further, several other techniques require offline profiling or per-application tuning and hence are not suitable for product systems. In thismore » book, we present novel cache leakage energy saving schemes for single-core and multicore systems; desktop, QoS, real-time and server systems. Also, we present cache energy saving techniques for caches designed with both conventional SRAM devices and emerging non-volatile devices such as STT-RAM (spin-torque transfer RAM). We present software-controlled, hardware-assisted techniques which use dynamic cache reconfiguration to configure the cache to the most energy efficient configuration while keeping the performance loss bounded. To profile and test a large number of potential configurations, we utilize low-overhead, micro-architecture components, which can be easily integrated into modern processor chips. We adopt a system-wide approach to save energy to ensure that cache reconfiguration does not increase energy consumption of other components of the processor. We have compared our techniques with state-of-the-art techniques and have found that our techniques outperform them in terms of energy efficiency and other relevant metrics. The techniques presented in this book have important applications in improving energy-efficiency of higher-end embedded, desktop, QoS, real-time, server processors and multitasking systems. This book is intended to be a valuable guide for both newcomers and veterans in the field of cache power management. It will help graduate students, CAD tool developers and designers in understanding the need of energy efficiency in modern computing systems. Further, it will be useful for researchers in gaining insights into algorithms and techniques for micro-architectural and system-level energy optimization using dynamic cache reconfiguration. We sincerely believe that the ``food for thought'' presented in this book will inspire the readers to develop even better ideas for designing ``green'' processors of tomorrow.« less
Jin, Meihua; Jung, Ji-Young; Lee, Jung-Ryun
2016-10-12
With the arrival of the era of Internet of Things (IoT), Wi-Fi Direct is becoming an emerging wireless technology that allows one to communicate through a direct connection between the mobile devices anytime, anywhere. In Wi-Fi Direct-based IoT networks, all devices are categorized by group of owner (GO) and client. Since portability is emphasized in Wi-Fi Direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi Direct standard defines two power-saving methods: Opportunistic and Notice of Absence (NoA) power-saving methods. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi Direct power-saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the lengths of awake intervals in a beacon interval dynamically. In addition, considering the inter-dependency among video frames, the proposed algorithm ensures that a video frame having high priority is transmitted with higher probability than other frames having low priority. Simulation results show that the proposed method outperforms the traditional NoA method in terms of average delay and energy efficiency.
Jin, Meihua; Jung, Ji-Young; Lee, Jung-Ryun
2016-01-01
With the arrival of the era of Internet of Things (IoT), Wi-Fi Direct is becoming an emerging wireless technology that allows one to communicate through a direct connection between the mobile devices anytime, anywhere. In Wi-Fi Direct-based IoT networks, all devices are categorized by group of owner (GO) and client. Since portability is emphasized in Wi-Fi Direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi Direct standard defines two power-saving methods: Opportunistic and Notice of Absence (NoA) power-saving methods. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi Direct power-saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the lengths of awake intervals in a beacon interval dynamically. In addition, considering the inter-dependency among video frames, the proposed algorithm ensures that a video frame having high priority is transmitted with higher probability than other frames having low priority. Simulation results show that the proposed method outperforms the traditional NoA method in terms of average delay and energy efficiency. PMID:27754315
Yip, Marcus; Jin, Rui; Nakajima, Hideko Heidi; Stankovic, Konstantina M; Chandrakasan, Anantha P
2015-01-01
A system-on-chip for an invisible, fully-implantable cochlear implant is presented. Implantable acoustic sensing is achieved by interfacing the SoC to a piezoelectric sensor that detects the sound-induced motion of the middle ear. Measurements from human cadaveric ears demonstrate that the sensor can detect sounds between 40 and 90 dB SPL over the speech bandwidth. A highly-reconfigurable digital sound processor enables system power scalability by reconfiguring the number of channels, and provides programmable features to enable a patient-specific fit. A mixed-signal arbitrary waveform neural stimulator enables energy-optimal stimulation pulses to be delivered to the auditory nerve. The energy-optimal waveform is validated with in-vivo measurements from four human subjects which show a 15% to 35% energy saving over the conventional rectangular waveform. Prototyped in a 0.18 μ m high-voltage CMOS technology, the SoC in 8-channel mode consumes 572 μ W of power including stimulation. The SoC integrates implantable acoustic sensing, sound processing, and neural stimulation on one chip to minimize the implant size, and proof-of-concept is demonstrated with measurements from a human cadaver ear.
NASA Technical Reports Server (NTRS)
Pinson, Robin M.; Schmitt, Terri L.; Hanson, John M.
2008-01-01
Six degree-of-freedom (DOF) launch vehicle trajectories are designed to follow an optimized 3-DOF reference trajectory. A vehicle has a finite amount of control power that it can allocate to performing maneuvers. Therefore, the 3-DOF trajectory must be designed to refrain from using 100% of the allowable control capability to perform maneuvers, saving control power for handling off-nominal conditions, wind gusts and other perturbations. During the Ares I trajectory analysis, two maneuvers were found to be hard for the control system to implement; a roll maneuver prior to the gravity turn and an angle of attack maneuver immediately after the J-2X engine start-up. It was decided to develop an approach for creating smooth maneuvers in the optimized reference trajectories that accounts for the thrust available from the engines. A feature of this method is that no additional angular velocity in the direction of the maneuver has been added to the vehicle after the maneuver completion. This paper discusses the equations behind these new maneuvers and their implementation into the Ares I trajectory design cycle. Also discussed is a possible extension to adjusting closed-loop guidance.
Targeting water and energy conservation using big data
NASA Astrophysics Data System (ADS)
Escriva-Bou, A.; Pulido-Velazquez, M.; Lund, J. R.
2016-12-01
Water conservation is often the most cost effective source of additional water supply for water stressed regions to maintain supply reliability with increasing population and/or demands, or shorter-term droughts. In previous research we demonstrated how including energy savings of conserved water can increase willingness to adopt conservation measures, at the same time that increases energy and GHG emissions savings. But the capacity to save water, energy and GHG emissions depends fundamentally in the economic benefits for customers and utilities. Utilities have traditionally used rebates, subsidies or incentives to enhance water conservation. But the economic benefits originated by these rebates depend on the actual savings of the water, energy and GHG emissions. A crucial issue that is not considered in the financial analysis of these rebates is the heterogeneity in water consumption, resulting in rebating households that actually do not need improvements in certain appliances. Smart meters with end-use disaggregation allow to consider this heterogeneity and to target rebates. By using an optimization approach that minimizes water and energy residential costs—accounting for retrofit costs and individual benefits according to previous levels of consumption—we are able to assess economically optimal rebate programs both for customers and utilities. Three programs are considered: first, same economic incentives are provided to all households and then they do their optimal decisions; second, traditional appliance-focused rebates are assessed; and third, utilities provide only rebates to those households that maximize water, energy or GHG emissions savings. Results show that the most economically efficient options for households are not the best options for utilities, and that traditional appliance-focused rebates are much less optimal than targeted rebates.
System Design Techniques for Reducing the Power Requirements of Advanced life Support Systems
NASA Technical Reports Server (NTRS)
Finn, Cory; Levri, Julie; Pawlowski, Chris; Crawford, Sekou; Luna, Bernadette (Technical Monitor)
2000-01-01
The high power requirement associated with overall operation of regenerative life support systems is a critical Z:p technological challenge. Optimization of individual processors alone will not be sufficient to produce an optimized system. System studies must be used in order to improve the overall efficiency of life support systems. Current research efforts at NASA Ames Research Center are aimed at developing approaches for reducing system power and energy usage in advanced life support systems. System energy integration and energy reuse techniques are being applied to advanced life support, in addition to advanced control methods for efficient distribution of power and thermal resources. An overview of current results of this work will be presented. The development of integrated system designs that reuse waste heat from sources such as crop lighting and solid waste processing systems will reduce overall power and cooling requirements. Using an energy integration technique known as Pinch analysis, system heat exchange designs are being developed that match hot and cold streams according to specific design principles. For various designs, the potential savings for power, heating and cooling are being identified and quantified. The use of state-of-the-art control methods for distribution of resources, such as system cooling water or electrical power, will also reduce overall power and cooling requirements. Control algorithms are being developed which dynamically adjust the use of system resources by the various subsystems and components in order to achieve an overall goal, such as smoothing of power usage and/or heat rejection profiles, while maintaining adequate reserves of food, water, oxygen, and other consumables, and preventing excessive build-up of waste materials. Reductions in the peak loading of the power and thermal systems will lead to lower overall requirements. Computer simulation models are being used to test various control system designs.
Aldhaibani, Jaafar A.; Yahya, Abid; Ahmad, R. Badlishah
2014-01-01
The poor capacity at cell boundaries is not enough to meet the growing demand and stringent design which required high capacity and throughput irrespective of user's location in the cellular network. In this paper, we propose new schemes for an optimum fixed relay node (RN) placement in LTE-A cellular network to enhance throughput and coverage extension at cell edge region. The proposed approach mitigates interferences between all nodes and ensures optimum utilization with the optimization of transmitted power. Moreover, we proposed a new algorithm to balance the transmitted power of moving relay node (MR) over cell size and providing required SNR and throughput at the users inside vehicle along with reducing the transmitted power consumption by MR. The numerical analysis along with the simulation results indicates that an improvement in capacity for users is 40% increment at downlink transmission from cell capacity. Furthermore, the results revealed that there is saving nearly 75% from transmitted power in MR after using proposed balancing algorithm. ATDI simulator was used to verify the numerical results, which deals with real digital cartographic and standard formats for terrain. PMID:24672378
Aldhaibani, Jaafar A; Yahya, Abid; Ahmad, R Badlishah
2014-01-01
The poor capacity at cell boundaries is not enough to meet the growing demand and stringent design which required high capacity and throughput irrespective of user's location in the cellular network. In this paper, we propose new schemes for an optimum fixed relay node (RN) placement in LTE-A cellular network to enhance throughput and coverage extension at cell edge region. The proposed approach mitigates interferences between all nodes and ensures optimum utilization with the optimization of transmitted power. Moreover, we proposed a new algorithm to balance the transmitted power of moving relay node (MR) over cell size and providing required SNR and throughput at the users inside vehicle along with reducing the transmitted power consumption by MR. The numerical analysis along with the simulation results indicates that an improvement in capacity for users is 40% increment at downlink transmission from cell capacity. Furthermore, the results revealed that there is saving nearly 75% from transmitted power in MR after using proposed balancing algorithm. ATDI simulator was used to verify the numerical results, which deals with real digital cartographic and standard formats for terrain.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Lijuan; Gonder, Jeff; Burton, Evan
This study evaluates the costs and benefits associated with the use of a stationary-wireless- power-transfer-enabled plug-in hybrid electric bus and determines the cost effectiveness relative to a conventional bus and a hybrid electric bus. A sensitivity sweep was performed over many different battery sizes, charging power levels, and number/location of bus stop charging stations. The net present cost was calculated for each vehicle design and provided the basis for design evaluation. In all cases, given the assumed economic conditions, the conventional bus achieved the lowest net present cost while the optimal plug-in hybrid electric bus scenario beat out the hybridmore » electric comparison scenario. The study also performed parameter sensitivity analysis under favorable and high unfavorable market penetration assumptions. The analysis identifies fuel saving opportunities with plug-in hybrid electric bus scenarios at cumulative net present costs not too dissimilar from those for conventional buses.« less
NREL's Work for the U.S. Navy Illuminates Energy and Cost Savings | News
load controls and whole-building energy efficiency retrofits as good investments for the Navy. " Program Director Steve Gorin said. Advanced power strips, a plug load control technology that cuts power and an office building with capacity for roughly 100 staff. While plug load savings depend on what can
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
2003-07-01
The Energy Smart Guide to Campus Cost Savings covers today's trends in project finance, combined heat& power, clean fuel fleets and emissions trading. The guide is directed at campus facilities and business managers and contains general guidance, contact information and case studies from colleges and universities across the country.
Commercialization of the power factor controller
NASA Technical Reports Server (NTRS)
1981-01-01
The purpose of the Motor Power Controller, also known as the Power Factor Controller, is to improve power factor and reduce power dissipation in induction motors operating below full load. These purposes were studied and tested in detail. The Motor Power Controller is capable of raising power factors from 0.2 to 0.8 and results in energy savings. It was found that many motors, in their present operating applications, are classified as unstable. The electronic nature of the controller vs. the electrical nature of the motor, compound this problem due to the differences in response time of the two devices. Many tests were successfully completed, the most indicating greater savings than anticipated. Also, there was an effect on efficiency which was not included in the calculations.
Zheng, Hong; Clausen, Morten Rahr; Dalsgaard, Trine Kastrup; Mortensen, Grith; Bertram, Hanne Christine
2013-08-06
We describe a time-saving protocol for the processing of LC-MS-based metabolomics data by optimizing parameter settings in XCMS and threshold settings for removing noisy and low-intensity peaks using design of experiment (DoE) approaches including Plackett-Burman design (PBD) for screening and central composite design (CCD) for optimization. A reliability index, which is based on evaluation of the linear response to a dilution series, was used as a parameter for the assessment of data quality. After identifying the significant parameters in the XCMS software by PBD, CCD was applied to determine their values by maximizing the reliability and group indexes. Optimal settings by DoE resulted in improvements of 19.4% and 54.7% in the reliability index for a standard mixture and human urine, respectively, as compared with the default setting, and a total of 38 h was required to complete the optimization. Moreover, threshold settings were optimized by using CCD for further improvement. The approach combining optimal parameter setting and the threshold method improved the reliability index about 9.5 times for a standards mixture and 14.5 times for human urine data, which required a total of 41 h. Validation results also showed improvements in the reliability index of about 5-7 times even for urine samples from different subjects. It is concluded that the proposed methodology can be used as a time-saving approach for improving the processing of LC-MS-based metabolomics data.
Agreement Technologies for Energy Optimization at Home.
González-Briones, Alfonso; Chamoso, Pablo; De La Prieta, Fernando; Demazeau, Yves; Corchado, Juan M
2018-05-19
Nowadays, it is becoming increasingly common to deploy sensors in public buildings or homes with the aim of obtaining data from the environment and taking decisions that help to save energy. Many of the current state-of-the-art systems make decisions considering solely the environmental factors that cause the consumption of energy. These systems are successful at optimizing energy consumption; however, they do not adapt to the preferences of users and their comfort. Any system that is to be used by end-users should consider factors that affect their wellbeing. Thus, this article proposes an energy-saving system, which apart from considering the environmental conditions also adapts to the preferences of inhabitants. The architecture is based on a Multi-Agent System (MAS), its agents use Agreement Technologies (AT) to perform a negotiation process between the comfort preferences of the users and the degree of optimization that the system can achieve according to these preferences. A case study was conducted in an office building, showing that the proposed system achieved average energy savings of 17.15%.
12 CFR 550.10 - What regulations govern the fiduciary operations of savings associations?
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false What regulations govern the fiduciary operations of savings associations? 550.10 Section 550.10 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS § 550.10 What regulations govern the...
12 CFR 550.10 - What regulations govern the fiduciary operations of savings associations?
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false What regulations govern the fiduciary operations of savings associations? 550.10 Section 550.10 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS § 550.10 What regulations govern the...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sethuraman, Latha; Quick, Julian; Guo, Yi
Drivetrain design has significant influence on the costs of wind power generation. Current industry practices usually approach the drivetrain design with loads and system requirements defined by the turbine manufacturer. Several different manufacturers are contracted to supply individual components from the low-speed shaft to the generator - each receiving separate design specifications from the turbine manufacturer. Increasingly, more integrated approaches to turbine design have shown promise for blades and towers. Yet, integrated drivetrain design is a challenging task owing to the complex physical behavior of the important load-bearing components, namely the main bearings, gearbox, and the generator. In this papermore » we combine two of NREL's systems engineering design tools, DriveSE and GeneratorSE, to enable a comprehensive system-level drivetrain optimization for the IEAWind reference turbine for land-based applications. We compare a more traditional design with integrated approaches employing decoupled and coupled design optimization. It is demonstrated that both approaches have the potential to realize notable mass savings with opportunities to lower the costs of energy.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sethuraman, Latha; Quick, Julian; Guo, Yi
Drivetrain design has significant influence on the costs of wind power generation. Current industry practices usually approach the drivetrain design with loads and system requirements defined by the turbine manufacturer. Several different manufacturers are contracted to supply individual components from the low-speed shaft to the generator - each receiving separate design specifications from the turbine manufacturer. Increasingly, more integrated approaches to turbine design have shown promise for blades and towers. Yet, integrated drivetrain design is a challenging task owing to the complex physical behavior of the important load-bearing components, namely the main bearings, gearbox, and the generator. In this papermore » we combine two of NREL's systems engineering design tools, DriveSE and GeneratorSE, to enable a comprehensive system-level drivetrain optimization for the IEAWind reference turbine for land-based applications. We compare a more traditional design with integrated approaches employing decoupled and coupled design optimization. It is demonstrated that both approaches have the potential to realize notable mass savings with opportunities to lower the costs of energy.« less
Classifier-Guided Sampling for Complex Energy System Optimization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Backlund, Peter B.; Eddy, John P.
2015-09-01
This report documents the results of a Laboratory Directed Research and Development (LDRD) effort enti tled "Classifier - Guided Sampling for Complex Energy System Optimization" that was conducted during FY 2014 and FY 2015. The goal of this proj ect was to develop, implement, and test major improvements to the classifier - guided sampling (CGS) algorithm. CGS is type of evolutionary algorithm for perform ing search and optimization over a set of discrete design variables in the face of one or more objective functions. E xisting evolutionary algorithms, such as genetic algorithms , may require a large number of omore » bjecti ve function evaluations to identify optimal or near - optimal solutions . Reducing the number of evaluations can result in significant time savings, especially if the objective function is computationally expensive. CGS reduce s the evaluation count by us ing a Bayesian network classifier to filter out non - promising candidate designs , prior to evaluation, based on their posterior probabilit ies . In this project, b oth the single - objective and multi - objective version s of the CGS are developed and tested on a set of benchm ark problems. As a domain - specific case study, CGS is used to design a microgrid for use in islanded mode during an extended bulk power grid outage.« less
Mission aware energy saving strategies for Army ground vehicles
NASA Astrophysics Data System (ADS)
Dattathreya, Macam S.
Fuel energy is a basic necessity for this planet and the modern technology to perform many activities on earth. On the other hand, quadrupled automotive vehicle usage by the commercial industry and military has increased fuel consumption. Military readiness of Army ground vehicles is very important for a country to protect its people and resources. Fuel energy is a major requirement for Army ground vehicles. According to a report, a department of defense has spent nearly $13.6 billion on fuel and electricity to conduct ground missions. On the contrary, energy availability on this plant is slowly decreasing. Therefore, saving energy in Army ground vehicles is very important. Army ground vehicles are embedded with numerous electronic systems to conduct missions such as silent and normal stationary surveillance missions. Increasing electrical energy consumption of these systems is influencing higher fuel consumption of the vehicle. To save energy, the vehicles can use any of the existing techniques, but they require complex, expensive, and time consuming implementations. Therefore, cheaper and simpler approaches are required. In addition, the solutions have to save energy according to mission needs and also overcome size and weight constraints of the vehicle. Existing research in the current literature do not have any mission aware approaches to save energy. This dissertation research proposes mission aware online energy saving strategies for stationary Army ground vehicles to save energy as well as to meet the electrical needs of the vehicle during surveillance missions. The research also proposes theoretical models of surveillance missions, fuzzy logic models of engine and alternator efficiency data, and fuzzy logic algorithms. Based on these models, two energy saving strategies are proposed for silent and normal surveillance type of missions. During silent mission, the engine is on and batteries power the systems. During normal surveillance mission, the engine is on, gear is on neutral position, the vehicle is stationary, and the alternator powers the systems. The proposed energy saving strategy for silent surveillance mission minimizes unnecessary battery discharges by controlling the power states of systems according to the mission needs and available battery capacity. Initial experiments show that the proposed approach saves 3% energy when compared with the baseline strategy for one scenario and 1.8% for the second scenario. The proposed energy saving strategy for normal surveillance mission operates the engine at fuel-efficient speeds to meet vehicle demand and to save fuel. The experiment and simulation uses a computerized vehicle model and a test bench to validate the approach. In comparison to vehicles with fixed high-idle engine speed increments, experiments show that the proposed strategy saves fuel energy in the range of 0-4.9% for the tested power demand range of 44-69 kW. It is hoped to implement the proposed strategies on a real Army ground vehicle to start realizing the energy savings.
NASA Astrophysics Data System (ADS)
Libraro, Paola
The general electric propulsion orbit-raising maneuver of a spacecraft must contend with four main limiting factors: the longer time of flight, multiple eclipses prohibiting continuous thrusting, long exposure to radiation from the Van Allen belt and high power requirement of the electric engines. In order to optimize a low-thrust transfer with respect to these challenges, the choice of coordinates and corresponding equations of motion used to describe the kinematical and dynamical behavior of the satellite is of critical importance. This choice can potentially affect the numerical optimization process as well as limit the set of mission scenarios that can be investigated. To increase the ability to determine the feasible set of mission scenarios able to address the challenges of an all-electric orbit-raising, a set of equations free of any singularities is required to consider a completely arbitrary injection orbit. For this purpose a new quaternion-based formulation of a spacecraft translational dynamics that is globally nonsingular has been developed. The minimum-time low-thrust problem has been solved using the new set of equations of motion inside a direct optimization scheme in order to investigate optimal low-thrust trajectories over the full range of injection orbit inclinations between 0 and 90 degrees with particular focus on high-inclinations. The numerical results consider a specific mission scenario in order to analyze three key aspects of the problem: the effect of the initial guess on the shape and duration of the transfer, the effect of Earth oblateness on transfer time and the role played by, radiation damage and power degradation in all-electric minimum-time transfers. Finally trade-offs between mass and cost savings are introduced through a test case.
Synchronous Firefly Algorithm for Cluster Head Selection in WSN.
Baskaran, Madhusudhanan; Sadagopan, Chitra
2015-01-01
Wireless Sensor Network (WSN) consists of small low-cost, low-power multifunctional nodes interconnected to efficiently aggregate and transmit data to sink. Cluster-based approaches use some nodes as Cluster Heads (CHs) and organize WSNs efficiently for aggregation of data and energy saving. A CH conveys information gathered by cluster nodes and aggregates/compresses data before transmitting it to a sink. However, this additional responsibility of the node results in a higher energy drain leading to uneven network degradation. Low Energy Adaptive Clustering Hierarchy (LEACH) offsets this by probabilistically rotating cluster heads role among nodes with energy above a set threshold. CH selection in WSN is NP-Hard as optimal data aggregation with efficient energy savings cannot be solved in polynomial time. In this work, a modified firefly heuristic, synchronous firefly algorithm, is proposed to improve the network performance. Extensive simulation shows the proposed technique to perform well compared to LEACH and energy-efficient hierarchical clustering. Simulations show the effectiveness of the proposed method in decreasing the packet loss ratio by an average of 9.63% and improving the energy efficiency of the network when compared to LEACH and EEHC.
Assessing the Decline in the National Saving Rate
1993-04-01
and on the Contributions of the Government and Private Sectors xii 1. NIPA Measure of National Saving as a Percentage of Gross National Product 2 2...System of National Accounts Measure of National Saving Rates 3 3. Per Capita Gross Domestic Product in 1990 U.S. Dollars Adjusted for Purchasing Power... Product 4 6. Nonresidential and Residential Capital Consumption as a Percentage of Gross National Product and Capital Stocks 10 7. Net National Saving as
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sethuraman, Latha; Fingersh, Lee J; Dykes, Katherine L
As wind turbine blade diameters and tower height increase to capture more energy in the wind, higher structural loads results in more structural support material increasing the cost of scaling. Weight reductions in the generator transfer to overall cost savings of the system. Additive manufacturing facilitates a design-for-functionality approach, thereby removing traditional manufacturing constraints and labor costs. The most feasible additive manufacturing technology identified for large, direct-drive generators in this study is powder-binder jetting of a sand cast mold. A parametric finite element analysis optimization study is performed, optimizing for mass and deformation. Also, topology optimization is employed for eachmore » parameter-optimized design.The optimized U-beam spoked web design results in a 24 percent reduction in structural mass of the rotor and 60 percent reduction in radial deflection.« less
Ruthenium Oxide Electrochemical Super Capacitor Optimization for Pulse Power Applications
NASA Technical Reports Server (NTRS)
Merryman, Stephen A.; Chen, Zheng
2000-01-01
Electrical actuator systems are being pursued as alternatives to hydraulic systems to reduce maintenance time, weight and costs while increasing reliability. Additionally, safety and environmental hazards associated with the hydraulic fluids can be eliminated. For most actuation systems, the actuation process is typically pulsed with high peak power requirements but with relatively modest average power levels. The power-time requirements for electrical actuators are characteristic of pulsed power technologies where the source can be sized for the average power levels while providing the capability to achieve the peak requirements. Among the options for the power source are battery systems, capacitor systems or battery-capacitor hybrid systems. Battery technologies are energy dense but deficient in power density; capacitor technologies are power dense but limited by energy density. The battery-capacitor hybrid system uses the battery to supply the average power and the capacitor to meet the peak demands. It has been demonstrated in previous work that the hybrid electrical power source can potentially provide a weight savings of approximately 59% over a battery-only source. Electrochemical capacitors have many properties that make them well-suited for electrical actuator applications. They have the highest demonstrated energy density for capacitive storage (up to 100 J/g), have power densities much greater than most battery technologies (greater than 30kW/kg), are capable of greater than one million charge-discharge cycles, can be charged at extremely high rates, and have non-explosive failure modes. Thus, electrochemical capacitors exhibit a combination of desirable battery and capacitor characteristics.
NASA Astrophysics Data System (ADS)
Alzoubi, Hussain Hendi
Energy consumption in buildings has recently become a major concern for environmental designers. Within this field, daylighting and solar energy design are attractive strategies for saving energy. This study seeks the integrity and the optimality of building envelopes' performance. It focuses on the transparent parts of building facades, specifically, the windows and their shading devices. It suggests a new automated method of utilizing solar energy while keeping optimal solutions for indoor daylighting. The method utilizes a statistical approach to produce mathematical equations based on physical experimentation. A full-scale mock-up representing an actual office was built. Heat gain and lighting levels were measured empirically and correlated with blind angles. Computational methods were used to estimate the power production from photovoltaic cells. Mathematical formulas were derived from the results of the experiments; these formulas were utilized to construct curves as well as mathematical equations for the purpose of optimization. The mathematical equations resulting from the optimization process were coded using Java programming language to enable future users to deal with generic locations of buildings with a broader context of various climatic conditions. For the purpose of optimization by automation under different climatic conditions, a blind control system was developed based on the findings of this study. This system calibrates the blind angles instantaneously based upon the sun position, the indoor daylight, and the power production from the photovoltaic cells. The functions of this system guarantee full control of the projected solar energy on buildings' facades for indoor lighting and heat gain. In winter, the system automatically blows heat into the space, whereas it expels heat from the space during the summer season. The study showed that the optimality of building facades' performance is achievable for integrated thermal, energy, and lighting models in buildings. There are blind angles that produce maximum energy from the photovoltaic cells while keeping indoor light within the acceptable limits that prevent undesired heat gain in summer.
Alternative Fuels Data Center: Hydrogen Powers Fuel Cell Vehicles in
. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of an electric vehicle at Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Gas Street Sweepers Improve Air Quality in New York March 11, 2010 Propane Buses Save Money for
Preliminary assessment of alternative PFBC power plant systems. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wysocki, J.; Rogali, R.
1980-07-01
This report presents the design and and economic comparisons of the following nominal 1000 MWe PFBC power plants for both eastern and western coal: Curtiss-Wright PFBC power plants with an air-cooled design; General Electric RFBC power plants with a steam-cooled design; and AEP/Stal-Laval PFBC power plants with a steam-cooled design. In addition, reference pulverized coal-fired (PCF) power plants are included for comparison purposes. The results of the analysis indicate: (1) The steam-cooled PFBC designs show potential savings of 10% and 11% over PCF plants for eastern and western coal, respectively, in terms of busbar power cost; (2) the air-cooled PFBCmore » designs show potential savings of 1% and 2% over PCF plants for eastern and western coal, respectively, in terms of busbar power cost.« less
Stretching Energy Dollars for Healthy Schools
ERIC Educational Resources Information Center
Angerame, Timothy
2011-01-01
When financial savings are critical to every institution, facility managers demand even more from their energy systems while looking to spend less. One way to achieve significant energy savings and healthy schools without making a substantial capital investment is through energy monitoring and chiller plant optimization. The greatest energy…
21st century locomotive technology: quarterly technical status report 26
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lembit Salasoo; Ramu Chandra
2009-08-24
Parasitic losses due to hybrid sodium battery thermal management do not significantly reduce the fuel saving benefits of the hybrid locomotive. Optimal thermal management trajectories were converted into realizable algorithms which were robust and gave excellent performance to limit thermal excusions and maintain fuel savings.
Joule-Thief Circuit Performance for Electricity Energy Saving of Emergency Lamps
NASA Astrophysics Data System (ADS)
Nuryanto Budisusila, Eka; Arifin, Bustanul
2017-04-01
The alternative energy such as battery as power source is required as energy source failures. The other need is outdoor lighting. The electrical power source is expected to be a power saving, optimum and has long life operating. The Joule-Thief circuit is one of solution method for energy saving by using raised electromagnetic force on cored coil when there is back-current. This circuit has a transistor operated as a switch to cut voltage and current flowing along the coils. The present of current causing magnetic induction and generates energy. Experimental prototype was designed by using battery 1.5V to activate Light Emitting Diode or LED as load. The LED was connected in parallel or serial circuit configuration. The result show that the joule-thief circuit able to supply LED circuits up to 40 LEDs.
Weight and power savings shaft encoder interfacing techniques for aerospace applications
NASA Technical Reports Server (NTRS)
Breslow, Donald H.
1986-01-01
Many aerospace applications for shaft angle digitizers such as optical shaft encoders require special features that are not usually required on commercial products. Among the most important user considerations are the lowest possible weight and power consumption. A variety of mechanical and electrical interface techniques that have large potential weight and power savings are described. The principles to be presented apply to a wide variety of encoders, ranging from 16 to 22 bit resolution and with diameters from 152 to 380 mm (6 to 15 in.).
Lee, HyungJune; Kim, HyunSeok; Chang, Ik Joon
2014-01-01
We propose a technique to optimize the energy efficiency of data collection in sensor networks by exploiting a selective data compression. To achieve such an aim, we need to make optimal decisions regarding two aspects: (1) which sensor nodes should execute compression; and (2) which compression algorithm should be used by the selected sensor nodes. We formulate this problem into binary integer programs, which provide an energy-optimal solution under the given latency constraint. Our simulation results show that the optimization algorithm significantly reduces the overall network-wide energy consumption for data collection. In the environment having a stationary sink from stationary sensor nodes, the optimized data collection shows 47% energy savings compared to the state-of-the-art collection protocol (CTP). More importantly, we demonstrate that our optimized data collection provides the best performance in an intermittent network under high interference. In such networks, we found that the selective compression for frequent packet retransmissions saves up to 55% energy compared to the best known protocol. PMID:24721763
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reber, Timothy J; Chartan, Erol Kevin; Brinkman, Gregory L
Wind and solar power contract prices have recently become cheaper than many conventional new-build alternatives in South Africa and trends suggest a continued increase in the share of variable renewable energy (vRE) on South Africa's power system with coal technology seeing the greatest reduction in capacity, see 'Figure 6: Percentage share by Installed Capacity (MW)' in [1]. Hence it is essential to perform a state-of-the-art grid integration study examining the effects of these high penetrations of vRE on South Africa's power system. Under the 21st Century Power Partnership (21CPP), funded by the U.S. Department of Energy, the National Renewable Energymore » Laboratory (NREL) has significantly augmented existing models of the South African power system to investigate future vRE scenarios. NREL, in collaboration with Eskom's Planning Department, further developed, tested and ran a combined capacity expansion and operational model of the South African power system including spatially disaggregated detail and geographical representation of system resources. New software to visualize and interpret modelling outputs has been developed, and scenario analysis of stepwise vRE build targets reveals new insight into associated planning and operational impacts and costs. The model, built using PLEXOS, is split into two components, firstly a capacity expansion model and secondly a unit commitment and economic dispatch model. The capacity expansion model optimizes new generation decisions to achieve the lowest cost, with a full understanding of capital cost and an approximated understanding of operational costs. The operational model has a greater set of detailed operational constraints and is run at daily resolutions. Both are run from 2017 through 2050. This investigation suggests that running both models in tandem may be the most effective means to plan the least cost South African power system as build plans seen to be more expensive than optimal by the capacity expansion model can produce greater operational cost savings seen only in the operational model.« less
Improving energy efficiency of Embedded DRAM Caches for High-end Computing Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mittal, Sparsh; Vetter, Jeffrey S; Li, Dong
2014-01-01
With increasing system core-count, the size of last level cache (LLC) has increased and since SRAM consumes high leakage power, power consumption of LLCs is becoming a significant fraction of processor power consumption. To address this, researchers have used embedded DRAM (eDRAM) LLCs which consume low-leakage power. However, eDRAM caches consume a significant amount of energy in the form of refresh energy. In this paper, we propose ESTEEM, an energy saving technique for embedded DRAM caches. ESTEEM uses dynamic cache reconfiguration to turn-off a portion of the cache to save both leakage and refresh energy. It logically divides the cachemore » sets into multiple modules and turns-off possibly different number of ways in each module. Microarchitectural simulations confirm that ESTEEM is effective in improving performance and energy efficiency and provides better results compared to a recently-proposed eDRAM cache energy saving technique, namely Refrint. For single and dual-core simulations, the average saving in memory subsystem (LLC+main memory) on using ESTEEM is 25.8% and 32.6%, respectively and average weighted speedup are 1.09X and 1.22X, respectively. Additional experiments confirm that ESTEEM works well for a wide-range of system parameters.« less
Solar Glazing Tips for School Construction
ERIC Educational Resources Information Center
Smith, Jonathan
2012-01-01
Glazing can be optimized to enhance passive solar heating and daylight harvesting by exceeding the prescriptive limits of the energy code. This savings can be garnered without the high cost of external overhangs or expensive glazing products. The majority of savings from solar glazing are attributable to the increase in solar heating and…
Artificial evolution of the morphology and kinematics in a flapping-wing mini-UAV.
de Margerie, E; Mouret, J B; Doncieux, S; Meyer, J-A
2007-12-01
Birds demonstrate that flapping-wing flight (FWF) is a versatile flight mode, compatible with hovering, forward flight and gliding to save energy. This extended flight domain would be especially useful on mini-UAVs. However, design is challenging because aerodynamic efficiency is conditioned by complex movements of the wings, and because many interactions exist between morphological (wing area, aspect ratio) and kinematic parameters (flapping frequency, stroke amplitude, wing unfolding). Here we used artificial evolution to optimize these morpho-kinematic features on a simulated 1 kg UAV, equipped with wings articulated at the shoulder and wrist. Flight tests were conducted in a dedicated steady aerodynamics simulator. Parameters generating horizontal flight for minimal mechanical power were retained. Results showed that flight at medium speed (10-12 m s(-1)) can be obtained for reasonable mechanical power (20 W kg(-1)), while flight at higher speed (16-20 m s(-1)) implied increased power (30-50 W kg(-1)). Flight at low speed (6-8 m s(-1)) necessitated unrealistic power levels (70-500 W kg(-1)), probably because our simulator neglected unsteady aerodynamics. The underlying adaptation of morphology and kinematics to varying flight speed were compared to available biological data on the flight of birds.
Investigating the water consumption for electricity generation at Turkish power plants
NASA Astrophysics Data System (ADS)
El-Khozondar, Balkess; Aydinalp Koksal, Merih
2017-11-01
The water-energy intertwined relationship has recently gained more importance due to the high water consumption in the energy sector and to the limited availability of the water resources. The energy and electricity demand of Turkey is increasing rapidly in the last two decades. More thermal power plants are expected to be built in the near future to supply the rapidly increasing demand in Turkey which will put pressure on water availability. In this study, the water consumption for electricity generation at Turkish power plants is investigated. The main objectives of this study are to identify the amount of water consumed to generate 1 kWh of electricity for each generation technology currently used in Turkey and to investigate ways to reduce the water consumption at power plants expected to be built in the near future to supply the increasing demand. The various electricity generation technology mixture scenarios are analyzed to determine the future total and per generation water consumption, and water savings based on changes of cooling systems used for each technology. The Long-range Energy Alternatives Planning (LEAP) program is used to determine the minimum water consuming electricity generation technology mixtures using optimization approaches between 2017 and 2035.
Lucas Martínez, Néstor; Martínez Ortega, José-Fernán; Hernández Díaz, Vicente; Del Toro Matamoros, Raúl M
2016-05-12
The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value.
Advanced shield development for a fission surface power system for the lunar surface
DOE Office of Scientific and Technical Information (OSTI.GOV)
A. E. Craft; I. J. Silver; C. M. Clark
A nuclear reactor power system such as the affordable fission surface power system enables a potential outpostonthemoon.Aradiation shieldmustbe included in the reactor system to reduce the otherwise excessive dose to the astronauts and other vital system components. The radiation shield is typically the most massive component of a space reactor system, and thus must be optimized to reduce mass asmuchas possible while still providing the required protection.Various shield options for an on-lander reactor system are examined for outpost distances of 400m and 1 kmfromthe reactor. Also investigated is the resulting mass savings from the use of a high performance cermetmore » fuel. A thermal analysis is performed to determine the thermal behaviours of radiation shields using borated water. For an outpost located 1000m from the core, a tetramethylammonium borohydride shield is the lightest (5148.4 kg), followed by a trilayer shield (boron carbide–tungsten–borated water; 5832.3 kg), and finally a borated water shield (6020.7 kg). In all of the final design cases, the temperature of the borated water remains below 400 K.« less
Usherwood, James R
2009-03-01
Predictions from aerodynamic theory often match biological observations very poorly. Many insects and several bird species habitually hover, frequently flying at low advance ratios. Taking helicopter-based aerodynamic theory, wings functioning predominantly for hovering, even for quite small insects, should operate at low angles of attack. However, insect wings operate at very high angles of attack during hovering; reduction in angle of attack should result in considerable energetic savings. Here, I consider the possibility that selection of kinematics is constrained from being aerodynamically optimal due to the inertial power requirements of flapping. Potential increases in aerodynamic efficiency with lower angles of attack during hovering may be outweighed by increases in inertial power due to the associated increases in flapping frequency. For simple hovering, traditional rotary-winged helicopter-like micro air vehicles would be more efficient than their flapping biomimetic counterparts. However, flapping may confer advantages in terms of top speed and manoeuvrability. If flapping-winged micro air vehicles are required to hover or loiter more efficiently, dragonflies and mayflies suggest biomimetic solutions.
Lucas Martínez, Néstor; Martínez Ortega, José-Fernán; Hernández Díaz, Vicente; del Toro Matamoros, Raúl M.
2016-01-01
The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value. PMID:27187397
Wen, Zongguo; Xu, Chang; Zhang, Xueying
2015-03-17
Reduction of water pollutant emissions and energy consumption is regarded as a key environmental objective for the pulp and paper industry. The paper develops a bottom-up model called the Industrial Water Pollutant Control and Technology Policy (IWPCTP) based on an industrial technology simulation system and multiconstraint technological optimization. Five policy scenarios covering the business as usual (BAU) scenario, the structural adjustment (SA) scenario, the cleaner technology promotion (CT) scenario, the end-treatment of pollutants (EOP) scenario, and the coupling measures (CM) scenario have been set to describe future policy measures related to the development of the pulp and paper industry from 2010-2020. The outcome of this study indicates that the energy saving amount under the CT scenario is the largest, while that under the SA scenario is the smallest. Under the CT scenario, savings by 2020 include 70 kt/year of chemical oxygen demand (COD) emission reductions and savings of 7443 kt of standard coal, 539.7 ton/year of ammonia nitrogen (NH4-N) emission reductions, and savings of 7444 kt of standard coal. Taking emission reductions, energy savings, and cost-benefit into consideration, cleaner technologies like highly efficient pulp washing, dry and wet feedstock preparation, and horizontal continuous cooking, medium and high consistency pulping and wood dry feedstock preparation are recommended.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Garbesi, Karina; Vossos, Vagelis; Sanstad, Alan
An increasing number of energy efficient appliances operate on direct current (DC) internally, offering the potential to use DC from renewable energy systems directly and avoiding the losses inherent in converting power to alternating current (AC) and back. This paper investigates that potential for net-metered residences with on-site photovoltaics (PV) by modeling the net power draw of the ‘direct-DC house’ with respect to today’s typical configuration, assuming identical DC-internal loads. Power draws were modeled for houses in 14 U.S. cities, using hourly, simulated PV-system output and residential loads. The latter were adjusted to reflect a 33% load reduction, representative ofmore » the most efficient DC-internal technology, based on an analysis of 32 electricity end-uses. The model tested the effect of climate, electric vehicle (EV) loads, electricity storage, and load shifting on electricity savings; a sensitivity analysis was conducted to determine how future changes in the efficiencies of power system components might affect savings potential. Based on this work, we estimate that net-metered PV residences could save 5% of their total electricity load for houses without storage and 14% for houses with storage. Based on residential PV penetration projections for year 2035 obtained from the National Energy Modeling System (2.7% for the reference case and 11.2% for the extended policy case), direct-DC could save the nation 10 trillion Btu (without storage) or 40 trillion Btu (with storage). Shifting the cooling load by two hours earlier in the day (pre-cooling) has negligible benefits for energy savings. Direct-DC provides no energy savings benefits for EV charging, to the extent that charging occurs at night. However, if charging occurred during the day, for example with employees charging while at work, the benefits would be large. Direct-DC energy savings are sensitive to power system and appliance conversion efficiencies but are not significantly influenced by climate. While direct-DC for residential applications will most likely arise as a spin-off of developments in the commercial sector—because of lower barriers to market entry and larger energy benefits resulting from the higher coincidence between load and insolation—this paper demonstrates that there are substantial benefits in the residential sector as well. Among residential applications, space cooling derives the largest energy savings from being delivered by a direct-DC system. It is the largest load for the average residence on a national basis and is particularly so in high-load regions. It is also the load with highest solar coincidence.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bagdon, M.J.; Martin, P.J.
1997-06-01
In 1994, Novus Engineering and EME Group began a project for the New York State Office of Mental Health (OMH) to maximize the use and benefit of energy management systems (EMS) installed at various large psychiatric hospitals throughout New York State. The project, which was funded and managed by the Dormitory Authority of the State of New York (DASNY), had three major objectives: (1) Maximize Energy Savings - Novus staff quickly learned that EMS systems as set up by contractors are far from optimal for generating energy savings. This part of the program revealed numerous opportunities for increased energy savings,more » such as: fine tuning proportional/integral/derivative (PID) loops to eliminate valve and damper hunting; adjusting temperature reset schedules to reduce energy consumption and provide more uniform temperature conditions throughout the facilities; and modifying equipment schedules. (2) Develop Monitoring Protocols - Large EMS systems are so complex that they require a systematic approach to daily, monthly and seasonal monitoring of building system conditions in order to locate system problems before they turn into trouble calls or equipment failures. In order to assist local facility staff in their monitoring efforts, Novus prepared user-friendly handbooks on each EMS. These included monitoring protocols tailored to each facility. (3) Provide Staff Training - When a new EMS is installed at a facility, it is frequently the maintenance staffs first exposure to a complex computerized system. Without proper training in what to look for, staff use of the EMS is generally very limited. With proper training, staff can be taught to take a pro-active approach to identify and solve problems before they get out of hand. The staff then realize that the EMS is a powerful preventative maintenance tool that can be used to make their work more effective and efficient. Case histories are presented.« less
Development of Miniaturized Optimized Smart Sensors (MOSS) for space plasmas
NASA Technical Reports Server (NTRS)
Young, D. T.
1993-01-01
The cost of space plasma sensors is high for several reasons: (1) Most are one-of-a-kind and state-of-the-art, (2) the cost of launch to orbit is high, (3) ruggedness and reliability requirements lead to costly development and test programs, and (4) overhead is added by overly elaborate or generalized spacecraft interface requirements. Possible approaches to reducing costs include development of small 'sensors' (defined as including all necessary optics, detectors, and related electronics) that will ultimately lead to cheaper missions by reducing (2), improving (3), and, through work with spacecraft designers, reducing (4). Despite this logical approach, there is no guarantee that smaller sensors are necessarily either better or cheaper. We have previously advocated applying analytical 'quality factors' to plasma sensors (and spacecraft) and have begun to develop miniaturized particle optical systems by applying quantitative optimization criteria. We are currently designing a Miniaturized Optimized Smart Sensor (MOSS) in which miniaturized electronics (e.g., employing new power supply topology and extensive us of gate arrays and hybrid circuits) are fully integrated with newly developed particle optics to give significant savings in volume and mass. The goal of the SwRI MOSS program is development of a fully self-contained and functional plasma sensor weighing 1 lb and requiring 1 W. MOSS will require only a typical spacecraft DC power source (e.g., 30 V) and command/data interfaces in order to be fully functional, and will provide measurement capabilities comparable in most ways to current sensors.
A Study on the Optimal Duration of Daylight Saving Time (DST) in Korea
NASA Astrophysics Data System (ADS)
Mihn, Byeong-Hee; Ahn, Young Sook; Kim, Dong-Bin; Yang, Hong-Jin
2009-09-01
Daylight saving time aims at spending effective daylight in summer season. Korea had enforced daylight saving time twelve times from 1948 to 1988. Since 1988, it is not executed, but it is recently discussed the resumption of DST. In this paper, we investigate the trend of DST in other countries, review the history of DST in Korea, and suggest the optimal DST duration in terms of astronomical aspects (times of sunrise and sunset). We find that the starting day of DST in Korea is apt for the second Sunday in May or the second Sunday in April according to the time of sunrise or to the difference between Korean standard meridian and observer's, respectively. We also discuss time friction that might be caused by time difference between DST and Korea Standard Time (KST).
NREL Evaluates Performance of Fast-Charge Electric Buses
DOE Office of Scientific and Technical Information (OSTI.GOV)
2016-09-16
This real-world performance evaluation is designed to enhance understanding of the overall usage and effectiveness of electric buses in transit operation and to provide unbiased technical information to other agencies interested in adding such vehicles to their fleets. Initial results indicate that the electric buses under study offer significant fuel and emissions savings. The final results will help Foothill Transit optimize the energy-saving potential of its transit fleet. NREL's performance evaluations help vehicle manufacturers fine-tune their designs and help fleet managers select fuel-efficient, low-emission vehicles that meet their bottom line and operational goals. help Foothill Transit optimize the energy-saving potentialmore » of its transit fleet. NREL's performance evaluations help vehicle manufacturers fine-tune their designs and help fleet managers select fuel-efficient, low-emission vehicles that meet their bottom line and operational goals.« less
National Space Biomedical Research Institute (NSBRI) JSC Summer Projects
NASA Technical Reports Server (NTRS)
Dowdy, Forrest Ryan
2014-01-01
This project optimized the calorie content in a breakfast meal replacement bar for the Advanced Food Technology group. Use of multivariable optimization yielded the highest weight savings possible while simultaneously matching NASA Human Standards nutritional guidelines. The scope of this research included the study of shelf-life indicators such as water activity, moisture content, and texture analysis. Key metrics indicate higher protein content, higher caloric density, and greater mass savings as a result of the reformulation process. The optimization performed for this study demonstrated wide application to other food bars in the Advanced Food Technology portfolio. Recommendations for future work include shelf life studies on bar hardening and overall acceptability data over increased time frames and temperature fluctuation scenarios.
Application of Waste Heat Recovery Energy Saving Technology in Reform of UHP-EAF
NASA Astrophysics Data System (ADS)
Zhao, J. H.; Zhang, S. X.; Yang, W.; Yu, T.
2017-08-01
The furnace waste heat of a company’s existing 4 × 100t ultra-high-power electric arc furnaces is not used and discharged directly of the situation has been unable to meet the national energy-saving emission reduction requirements, and also affected their own competitiveness and sustainable development. In order to make full use of the waste heat of the electric arc furnace, this paper presents an the energy-saving transformation program of using the new heat pipe boiler on the existing ultra-high-power electric arc furnaces for recovering the waste heat of flue gas. The results show that after the implementation of the project can save energy equivalent to 42,349 tons of standard coal. The flue gas waste heat is fully utilized and dust emission concentration is accorded with the standard of Chinese invironmental protection, which have achieved good results.
Agreement Technologies for Energy Optimization at Home
2018-01-01
Nowadays, it is becoming increasingly common to deploy sensors in public buildings or homes with the aim of obtaining data from the environment and taking decisions that help to save energy. Many of the current state-of-the-art systems make decisions considering solely the environmental factors that cause the consumption of energy. These systems are successful at optimizing energy consumption; however, they do not adapt to the preferences of users and their comfort. Any system that is to be used by end-users should consider factors that affect their wellbeing. Thus, this article proposes an energy-saving system, which apart from considering the environmental conditions also adapts to the preferences of inhabitants. The architecture is based on a Multi-Agent System (MAS), its agents use Agreement Technologies (AT) to perform a negotiation process between the comfort preferences of the users and the degree of optimization that the system can achieve according to these preferences. A case study was conducted in an office building, showing that the proposed system achieved average energy savings of 17.15%. PMID:29783768
Carbon-Carbon Recuperators in Closed-Brayton-Cycle Space Power Systems
NASA Technical Reports Server (NTRS)
Barrett, Michael J.; Johnson, Paul K.
2006-01-01
The use of carbon-carbon (C-C) recuperators in closed-Brayton-cycle space power conversion systems was assessed. Recuperator performance was forecast based on notional thermodynamic cycle state values for planetary missions. Resulting thermal performance, mass and volume for plate-fin C-C recuperators were estimated and quantitatively compared with values for conventional offset-strip-fin metallic designs. Mass savings of 40-55% were projected for C-C recuperators with effectiveness greater than 0.9 and thermal loads from 25-1400 kWt. The smaller thermal loads corresponded with lower mass savings; however, at least 50% savings were forecast for all loads above 300 kWt. System-related material challenges and compatibility issues were also discussed.
Biomechanical pulping of aspen chips; Energy savings resulting from different fungal treatments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leatham, G.F.; Myers, G.C.; Wegner, T.H.
1990-05-01
Besides increasing paper strength, fungal treatments can also reduce the electrical energy needed for fiberizing chips during mechanical pulping. Fungal species, chip movement, and treatment duration affected the extent of energy savings. This paper reports that four-week-long treatment with white-rot fungi, including Phlebia species or Pholiota mutabilis, in a stationary wire tray bioreactor resulted in at least 35% energy savings for pulping chips to 100 mL CSF in a 300-mm-diameter disc refiner. With Phanerochaete chrysosporium in a rotating-drum bioreactor, the optimal treatment duration was four weeks. Treatment with a brown-rot fungus also resulted in energy savings. Over the range ofmore » fungi and conditions tested, neither chip weight loss nor lignin loss correlated with energy savings. Some treatments giving the least chip weight loss ({lt}5%) saved the most energy. Wood modifications responsible for energy savings differed from those that increased strength. Treatments that saved the most energy did not necessarily give the highest strength properties.« less
NASA Astrophysics Data System (ADS)
Shawwash, Ziad Khaled Elias
2000-10-01
The electricity supply market is rapidly changing from a monopolistic to a competitive environment. Being able to operate their system of reservoirs and generating facilities to get maximum benefits out of existing assets and resources is important to the British Columbia Hydro Authority (B.C. Hydro). A decision support system has been developed to help B.C. Hydro operate their system in an optimal way. The system is operational and is one of the tools that are currently used by the B.C. Hydro system operations engineers to determine optimal schedules that meet the hourly domestic load and also maximize the value B.C. Hydro obtains from spot transactions in the Western U.S. and Alberta electricity markets. This dissertation describes the development and implementation of the decision support system in production mode. The decision support system consists of six components: the input data preparation routines, the graphical user interface (GUI), the communication protocols, the hydraulic simulation model, the optimization model, and the results display software. A major part of this work involved the development and implementation of a practical and detailed large-scale optimization model that determines the optimal tradeoff between the long-term value of water and the returns from spot trading transactions in real-time operations. The postmortem-testing phase showed that the gains in value from using the model accounted for 0.25% to 1.0% of the revenues obtained. The financial returns from using the decision support system greatly outweigh the costs of building it. Other benefits are the savings in the time needed to prepare the generation and trading schedules. The system operations engineers now can use the time saved to focus on other important aspects of their job. The operators are currently experimenting with the system in production mode, and are gradually gaining confidence that the advice it provides is accurate, reliable and sensible. The main lesson learned from developing and implementing the system was that there is no alternative to working very closely with the intended end-users of the system, and with the people who have deep knowledge, experience and understanding of how the system is and should be operated.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aswad, Z.A.R.; Al-Hadad, S.M.S.
1983-03-01
The powerful Rosenbrock search technique, which optimizes both the search directions using the Gram-Schmidt procedure and the step size using the Fibonacci line search method, has been used to optimize the drilling program of an oil well drilled in Bai-Hassan oil field in Kirkuk, Iran, using the twodimensional drilling model of Galle and Woods. This model shows the effect of the two major controllable variables, weight on bit and rotary speed, on the drilling rate, while considering other controllable variables such as the mud properties, hydrostatic pressure, hydraulic design, and bit selection. The effect of tooth dullness on the drillingmore » rate is also considered. Increasing the weight on the drill bit with a small increase or decrease in ratary speed resulted in a significant decrease in the drilling cost for most bit runs. It was found that a 48% reduction in this cost and a 97-hour savings in the total drilling time was possible under certain conditions.« less
Seol, Ye-In; Kim, Young-Kuk
2014-01-01
Power-aware scheduling reduces CPU energy consumption in hard real-time systems through dynamic voltage scaling (DVS). In this paper, we deal with pinwheel task model which is known as static and predictable task model and could be applied to various embedded or ubiquitous systems. In pinwheel task model, each task's priority is static and its execution sequence could be predetermined. There have been many static approaches to power-aware scheduling in pinwheel task model. But, in this paper, we will show that the dynamic priority scheduling results in power-aware scheduling could be applied to pinwheel task model. This method is more effective than adopting the previous static priority scheduling methods in saving energy consumption and, for the system being still static, it is more tractable and applicable to small sized embedded or ubiquitous computing. Also, we introduce a novel power-aware scheduling algorithm which exploits all slacks under preemptive earliest-deadline first scheduling which is optimal in uniprocessor system. The dynamic priority method presented in this paper could be applied directly to static systems of pinwheel task model. The simulation results show that the proposed algorithm with the algorithmic complexity of O(n) reduces the energy consumption by 10-80% over the existing algorithms.
2014-01-01
Power-aware scheduling reduces CPU energy consumption in hard real-time systems through dynamic voltage scaling (DVS). In this paper, we deal with pinwheel task model which is known as static and predictable task model and could be applied to various embedded or ubiquitous systems. In pinwheel task model, each task's priority is static and its execution sequence could be predetermined. There have been many static approaches to power-aware scheduling in pinwheel task model. But, in this paper, we will show that the dynamic priority scheduling results in power-aware scheduling could be applied to pinwheel task model. This method is more effective than adopting the previous static priority scheduling methods in saving energy consumption and, for the system being still static, it is more tractable and applicable to small sized embedded or ubiquitous computing. Also, we introduce a novel power-aware scheduling algorithm which exploits all slacks under preemptive earliest-deadline first scheduling which is optimal in uniprocessor system. The dynamic priority method presented in this paper could be applied directly to static systems of pinwheel task model. The simulation results show that the proposed algorithm with the algorithmic complexity of O(n) reduces the energy consumption by 10–80% over the existing algorithms. PMID:25121126
Space Evaporator Absorber Radiator (SEAR) for Thermal Storage on Manned Spacecraft
NASA Technical Reports Server (NTRS)
Izenson, Michael G.; Chen, Weibo; Chepko, Ariane; Bue, Grant; Quinn, Gregory
2014-01-01
Future manned exploration spacecraft will need to operate in challenging thermal environments. State-of the- art technology for active thermal control relies on sublimating water ice and venting the vapor overboard in very hot environments. This approach can lead to large loss of water and a significant mass penalty for the spacecraft. This paper describes an innovative thermal control system that uses a Space Evaporator Absorber Radiator (SEAR) to control spacecraft temperatures in highly variable environments without venting water. SEAR uses heat pumping and energy storage by LiCl/water absorption to enable effective cooling during hot periods and regeneration during cool periods. The LiCl absorber technology has the potential to absorb over 800 kJ per kg of system mass, compared to phase change heat sink systems that typically achieve approx. 50 kJ/kg. The optimal system is based on a trade-off between the mass of water saved and extra power needed to regenerate the LiCl absorber. This paper describes analysis models and the predicted performance and optimize the size of the SEAR system, estimated size and mass of key components, and power requirements for regeneration. We also present a concept design for an ISS test package to demonstrate operation of a subscale system in zero gravity.
Automatic Energy Schemes for High Performance Applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sundriyal, Vaibhav
Although high-performance computing traditionally focuses on the efficient execution of large-scale applications, both energy and power have become critical concerns when approaching exascale. Drastic increases in the power consumption of supercomputers affect significantly their operating costs and failure rates. In modern microprocessor architectures, equipped with dynamic voltage and frequency scaling (DVFS) and CPU clock modulation (throttling), the power consumption may be controlled in software. Additionally, network interconnect, such as Infiniband, may be exploited to maximize energy savings while the application performance loss and frequency switching overheads must be carefully balanced. This work first studies two important collective communication operations, all-to-allmore » and allgather and proposes energy saving strategies on the per-call basis. Next, it targets point-to-point communications to group them into phases and apply frequency scaling to them to save energy by exploiting the architectural and communication stalls. Finally, it proposes an automatic runtime system which combines both collective and point-to-point communications into phases, and applies throttling to them apart from DVFS to maximize energy savings. The experimental results are presented for NAS parallel benchmark problems as well as for the realistic parallel electronic structure calculations performed by the widely used quantum chemistry package GAMESS. Close to the maximum energy savings were obtained with a substantially low performance loss on the given platform.« less
NASA Astrophysics Data System (ADS)
Chen, Guangyan; Xia, Huaijian; Chen, Meiling; Wang, Dong; Jia, Sujin
2017-10-01
Energy saving and emission reduction policies affects the development of high power industry, thereby affecting electricity demand, so the study of the electricity industry boom helps to master the national economy. This paper analyses the influence of energy saving and emission reduction on power generation structure and pollutant emission in power industry. Through the construction of electricity market composite boom index to indicate electricity boom, using boom index to study volatility characteristics and trend of electricity market. Here we provide a method for the enterprise and the government, that it can infer the overall operation of the national economy situation from power data.
A power saving protocol for impedance spectroscopy
NASA Astrophysics Data System (ADS)
Bîrlea, Nicolae Marius
2017-12-01
Because power saving is a main concern of wearable devices we present here a transient method with a low power demand for impedance spectroscopy of the skin, but the idea is valid for other test materials. The used signal is an electrical pulse (the ON period) followed by a pause (the OFF period) when the electrodes do not consume current from the power supply. The method has the advantage of being able to measure at once the frequency characteristics of the impedance and is well suited for the time varying bioimpedance. In addition, this kind of measurement creates a more direct and explicit relationship between the lumped elements of the electrical model and the measured signal.
Baygin, Mehmet; Karakose, Mehmet
2013-01-01
Nowadays, the increasing use of group elevator control systems owing to increasing building heights makes the development of high-performance algorithms necessary in terms of time and energy saving. Although there are many studies in the literature about this topic, they are still not effective enough because they are not able to evaluate all features of system. In this paper, a new approach of immune system-based optimal estimate is studied for dynamic control of group elevator systems. The method is mainly based on estimation of optimal way by optimizing all calls with genetic, immune system and DNA computing algorithms, and it is evaluated with a fuzzy system. The system has a dynamic feature in terms of the situation of calls and the option of the most appropriate algorithm, and it also adaptively works in terms of parameters such as the number of floors and cabins. This new approach which provides both time and energy saving was carried out in real time. The experimental results comparatively demonstrate the effects of method. With dynamic and adaptive control approach in this study carried out, a significant progress on group elevator control systems has been achieved in terms of time and energy efficiency according to traditional methods. PMID:23935433
Kerl, Paul Y; Zhang, Wenxian; Moreno-Cruz, Juan B; Nenes, Athanasios; Realff, Matthew J; Russell, Armistead G; Sokol, Joel; Thomas, Valerie M
2015-09-01
Integrating accurate air quality modeling with decision making is hampered by complex atmospheric physics and chemistry and its coupling with atmospheric transport. Existing approaches to model the physics and chemistry accurately lead to significant computational burdens in computing the response of atmospheric concentrations to changes in emissions profiles. By integrating a reduced form of a fully coupled atmospheric model within a unit commitment optimization model, we allow, for the first time to our knowledge, a fully dynamical approach toward electricity planning that accurately and rapidly minimizes both cost and health impacts. The reduced-form model captures the response of spatially resolved air pollutant concentrations to changes in electricity-generating plant emissions on an hourly basis with accuracy comparable to a comprehensive air quality model. The integrated model allows for the inclusion of human health impacts into cost-based decisions for power plant operation. We use the new capability in a case study of the state of Georgia over the years of 2004-2011, and show that a shift in utilization among existing power plants during selected hourly periods could have provided a health cost savings of $175.9 million dollars for an additional electricity generation cost of $83.6 million in 2007 US dollars (USD2007). The case study illustrates how air pollutant health impacts can be cost-effectively minimized by intelligently modulating power plant operations over multihour periods, without implementing additional emissions control technologies.
Kerl, Paul Y.; Zhang, Wenxian; Moreno-Cruz, Juan B.; Nenes, Athanasios; Realff, Matthew J.; Russell, Armistead G.; Sokol, Joel; Thomas, Valerie M.
2015-01-01
Integrating accurate air quality modeling with decision making is hampered by complex atmospheric physics and chemistry and its coupling with atmospheric transport. Existing approaches to model the physics and chemistry accurately lead to significant computational burdens in computing the response of atmospheric concentrations to changes in emissions profiles. By integrating a reduced form of a fully coupled atmospheric model within a unit commitment optimization model, we allow, for the first time to our knowledge, a fully dynamical approach toward electricity planning that accurately and rapidly minimizes both cost and health impacts. The reduced-form model captures the response of spatially resolved air pollutant concentrations to changes in electricity-generating plant emissions on an hourly basis with accuracy comparable to a comprehensive air quality model. The integrated model allows for the inclusion of human health impacts into cost-based decisions for power plant operation. We use the new capability in a case study of the state of Georgia over the years of 2004–2011, and show that a shift in utilization among existing power plants during selected hourly periods could have provided a health cost savings of $175.9 million dollars for an additional electricity generation cost of $83.6 million in 2007 US dollars (USD2007). The case study illustrates how air pollutant health impacts can be cost-effectively minimized by intelligently modulating power plant operations over multihour periods, without implementing additional emissions control technologies. PMID:26283358
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abdelaziz, Omar; West, David L; Mallow, Anne M
Heating, ventilation, air-conditioning and refrigeration (HVACR) account for approximately one- third of building energy consumption. Magnetic refrigeration presents an opportunity for significant energy savings and emissions reduction for serving the building heating, cooling, and refrigeration loads. In this paper, we have examined the magnet and MCE material requirements for scaling magnetic refrigeration systems for commercial building cooling applications. Scaling relationships governing the resources required for magnetic refrigeration systems have been developed. As system refrigeration capacity increases, the use of superconducting magnet systems becomes more applicable, and a comparison is presented of system requirements for permanent and superconducting (SC) magnetization systems.more » Included in this analysis is an investigation of the ability of superconducting magnet based systems to overcome the parasitic power penalty of the cryocooler used to keep SC windings at cryogenic temperatures. Scaling relationships were used to develop the initial specification for a SC magnet-based active magnetic regeneration (AMR) system. An optimized superconducting magnet was designed to support this system. In this analysis, we show that the SC magnet system consisting of two 0.38 m3 regenerators is capable of producing 285 kW of cooling power with a T of 28 K. A system COP of 4.02 including cryocooler and fan losses which illustrates that an SC magnet-based system can operate with efficiency comparable to traditional systems and deliver large cooling powers of 285.4 kW (81.2 Tons).« less
2011 Naval Energy Forum. Volume 2
2011-10-14
APPLIED RESEARCH ASSOCIATES • CHASE SUPPLY, INC. • ESPEY MGF. & ELECTRONICS • FREE FLOW POWER • LIVEFUELS • MILSPRAY MILITARY TECHNOLOGIES • PETRA ... Martin Luther King experts reality check? 5 “Heavier-than-air flying machines are impossible” - Lord Kelvin, President, Royal Society, 1895 6 “The...1. Win-Win: Mutual Benefit & Value Proposition – DOD: Save Energy, Save Money, Save Lives (General Martin Dempsey) – DOE: Accelerate technology
Skylight energy performance and design optimization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Arasteh, D.; Johnson, R.; Selkowitz, S.
1984-02-01
Proper skylight utilization can significantly lower energy requirements and peak electrical loads for space conditioning and lighting in commercial buildings. In this study we systematically explore the energy effects of skylight systems in a prototypical office building and examine the savings from daylighting. The DOE-2.1B energy analysis computer program with its newly incorporated daylighting algorithms was used to generate more than 2000 parametric simulations for seven US climates. The parameters varied include skylight-to-roof ratio, shading coefficient, visible transmittance, skylight well light loss, electric lighting power density, roof heat transfer coefficient, and type of electric lighting control. For specific climates wemore » identify roof/skylight characteristics that minimize total energy or peak electrical load requirements.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Powell, Kody M.; Kim, Jong Suk; Cole, Wesley J.
2016-10-01
District energy systems can produce low-cost utilities for large energy networks, but can also be a resource for the electric grid by their ability to ramp production or to store thermal energy by responding to real-time market signals. In this work, dynamic optimization exploits the flexibility of thermal energy storage by determining optimal times to store and extract excess energy. This concept is applied to a polygeneration distributed energy system with combined heat and power, district heating, district cooling, and chilled water thermal energy storage. The system is a university campus responsible for meeting the energy needs of tens ofmore » thousands of people. The objective for the dynamic optimization problem is to minimize cost over a 24-h period while meeting multiple loads in real time. The paper presents a novel algorithm to solve this dynamic optimization problem with energy storage by decomposing the problem into multiple static mixed-integer nonlinear programming (MINLP) problems. Another innovative feature of this work is the study of a large, complex energy network which includes the interrelations of a wide variety of energy technologies. Results indicate that a cost savings of 16.5% is realized when the system can participate in the wholesale electricity market.« less
NASA Astrophysics Data System (ADS)
Cai, Xiaohui; Liu, Yang; Ren, Zhiming
2018-06-01
Reverse-time migration (RTM) is a powerful tool for imaging geologically complex structures such as steep-dip and subsalt. However, its implementation is quite computationally expensive. Recently, as a low-cost solution, the graphic processing unit (GPU) was introduced to improve the efficiency of RTM. In the paper, we develop three ameliorative strategies to implement RTM on GPU card. First, given the high accuracy and efficiency of the adaptive optimal finite-difference (FD) method based on least squares (LS) on central processing unit (CPU), we study the optimal LS-based FD method on GPU. Second, we develop the CPU-based hybrid absorbing boundary condition (ABC) to the GPU-based one by addressing two issues of the former when introduced to GPU card: time-consuming and chaotic threads. Third, for large-scale data, the combinatorial strategy for optimal checkpointing and efficient boundary storage is introduced for the trade-off between memory and recomputation. To save the time of communication between host and disk, the portable operating system interface (POSIX) thread is utilized to create the other CPU core at the checkpoints. Applications of the three strategies on GPU with the compute unified device architecture (CUDA) programming language in RTM demonstrate their efficiency and validity.
Pervious concrete mix optimization for sustainable pavement solution
NASA Astrophysics Data System (ADS)
Barišić, Ivana; Galić, Mario; Netinger Grubeša, Ivanka
2017-10-01
In order to fulfill requirements of sustainable road construction, new materials for pavement construction are investigated with the main goal to preserve natural resources and achieve energy savings. One of such sustainable pavement material is pervious concrete as a new solution for low volume pavements. To accommodate required strength and porosity as the measure of appropriate drainage capability, four mixtures of pervious concrete are investigated and results of laboratory tests of compressive and flexural strength and porosity are presented. For defining the optimal pervious concrete mixture in a view of aggregate and financial savings, optimization model is utilized and optimal mixtures defined according to required strength and porosity characteristics. Results of laboratory research showed that comparing single-sized aggregate pervious concrete mixtures, coarse aggregate mixture result in increased porosity but reduced strengths. The optimal share of the coarse aggregate turn to be 40.21%, the share of fine aggregate is 49.79% for achieving required compressive strength of 25 MPa, flexural strength of 4.31 MPa and porosity of 21.66%.
Aerosol corrosion prevention and energy-saving strategies in the design of green data centers.
Ferrero, Luca; Sangiorgi, Giorgia; Ferrini, Barbara S; Perrone, Maria G; Moscatelli, Marco; D'Angelo, Luca; Rovelli, Grazia; Ariatta, Alberto; Truccolo, Redy; Bolzacchini, Ezio
2013-04-16
The energy demands of data centers (DCs) worldwide are rapidly increasing, as are their environmental and economic costs. This paper presents a study conducted at Sannazzaro de' Burgondi (Po Valley), Italy, specifically aimed at optimizing the operating conditions of a DC designed for the Italian Oil and Gas Company (Eni) (5200 m(2) of Information Technology installed, 30 MW) and based on a direct free cooling (DFC) system. The aim of the study was to save the largest possible quantity of energy, while at the same time preventing aerosol corrosion. The aerosol properties (number size distribution, chemical composition, deliquescence relative humidity (DRH), acidity) and meteorological parameters were monitored and utilized to determine the potential levels of aerosol entering the DC (equivalent ISO class), together with its DRH. These data enabled us both to select the DC's filtering system (MERV13 filters) and to optimize the cooling cycle through calculation of the most reliable humidity cycle (60% of maximum allowed RH) applicable to the DFC. A potential energy saving of 81%, compared to a traditional air conditioning cooling system, was estimated: in one year, for 1 kW of installed information technology, the estimated energy saving is 7.4 MWh, resulting in 2.7 fewer tons of CO2 being emitted, and a financial saving of € 1100.
Multi-level optimization of a beam-like space truss utilizing a continuum model
NASA Technical Reports Server (NTRS)
Yates, K.; Gurdal, Z.; Thangjitham, S.
1992-01-01
A continuous beam model is developed for approximate analysis of a large, slender, beam-like truss. The model is incorporated in a multi-level optimization scheme for the weight minimization of such trusses. This scheme is tested against traditional optimization procedures for savings in computational cost. Results from both optimization methods are presented for comparison.
Aircraft Photovoltaic Power-Generating System.
NASA Astrophysics Data System (ADS)
Doellner, Oscar Leonard
Photovoltaic cells, appropriately cooled and operating in the combustion-created high radiant-intensity environment of gas-turbine and jet engines, may replace the conventional (gearbox-driven) electrical power generators aboard jet aircraft. This study projects significant improvements not only in aircraft electrical power-generating-system performance, but also in overall aircraft performance. Jet -engine design modifications incorporating this concept not only save weight (and thus fuel), but are--in themselves --favorable to jet-engine performance. The dissertation concentrates on operational, constructional, structural, thermal, optical, radiometrical, thin-film, and solid-state theoretical aspects of the overall project. This new electrical power-generating system offers solid-state reliability with electrical power-output capability comparable to that of existing aircraft electromechanical power-generating systems (alternators and generators). In addition to improvements in aircraft performance, significant aircraft fuel- and weight-saving advantages are projected.
Application of Superconducting Power Cables to DC Electric Railway Systems
NASA Astrophysics Data System (ADS)
Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru
For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.
H2OTSTUF: Appropriate Operating Regimes for Magnetohydrodynamic Augmentation
NASA Technical Reports Server (NTRS)
Jones, Jonathan E.; Hawk, Clark W.
1998-01-01
A trade study of magnetohydrodynamic (MHD) augmented propulsion reveals a unique operating regime at lower thrust levels. Substantial mass savings are realized over conventional chemical, solar, and electrical propulsion concepts when MHD augmentation is used to obtain optimal I(sub sp). However, trip times for the most conservative estimates of power plant specific impulse and accelerator efficiency may be prohibitively long. Quasi-one-dimensional calculations show that a solar or nuclear thermal system augmented by MHD can provide competitive performance while utilizing a diverse range of propellants including water, which is available from the Space Shuttle, the Moon, asteroids, and various moons and planets within our solar system. The use of in-situ propellants will reduce costs of space operations as well as enable human exploration of our Solar System. The following conclusions can be drawn from the results of the mission trade study: (1) There exists a maximum thrust or mass flow rate above which MHD augmentation increases the initial mass in low earth orbit (LEO); (2) Mass saving of over 50% can be realized for unique combination of solar/MHD systems; (3) Trip times for systems utilizing current power supply technology may be prohibitively long. Theoretical predictions of MHD performance for in space propulsion systems show that improved efficiencies can reduce trip times to acceptable levels; (4) Long trip times indicative of low thrust systems can be shortened by an increase in the MHD accelerator efficiency or a decrease in the specific mass of the power supply and power processing unit; and (5) As for all propulsion concepts, missions with larger (Delta)v's benefit more from the increased specific impulse resulting from MHD augmentation. Using a quasi-one-dimensional analysis, the required operating conditions for a MHD accelerator to reach acceptable efficiencies are outlined. This analysis shows that substantial non-equilibrium ionization is desirable.
Predictive Optimal Control of Active and Passive Building Thermal Storage Inventory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gregor P. Henze; Moncef Krarti
2005-09-30
Cooling of commercial buildings contributes significantly to the peak demand placed on an electrical utility grid. Time-of-use electricity rates encourage shifting of electrical loads to off-peak periods at night and weekends. Buildings can respond to these pricing signals by shifting cooling-related thermal loads either by precooling the building's massive structure or the use of active thermal energy storage systems such as ice storage. While these two thermal batteries have been engaged separately in the past, this project investigated the merits of harnessing both storage media concurrently in the context of predictive optimal control. To pursue the analysis, modeling, and simulationmore » research of Phase 1, two separate simulation environments were developed. Based on the new dynamic building simulation program EnergyPlus, a utility rate module, two thermal energy storage models were added. Also, a sequential optimization approach to the cost minimization problem using direct search, gradient-based, and dynamic programming methods was incorporated. The objective function was the total utility bill including the cost of reheat and a time-of-use electricity rate either with or without demand charges. An alternative simulation environment based on TRNSYS and Matlab was developed to allow for comparison and cross-validation with EnergyPlus. The initial evaluation of the theoretical potential of the combined optimal control assumed perfect weather prediction and match between the building model and the actual building counterpart. The analysis showed that the combined utilization leads to cost savings that is significantly greater than either storage but less than the sum of the individual savings. The findings reveal that the cooling-related on-peak electrical demand of commercial buildings can be considerably reduced. A subsequent analysis of the impact of forecasting uncertainty in the required short-term weather forecasts determined that it takes only very simple short-term prediction models to realize almost all of the theoretical potential of this control strategy. Further work evaluated the impact of modeling accuracy on the model-based closed-loop predictive optimal controller to minimize utility cost. The following guidelines have been derived: For an internal heat gain dominated commercial building, reasonable geometry simplifications are acceptable without a loss of cost savings potential. In fact, zoning simplification may improve optimizer performance and save computation time. The mass of the internal structure did not show a strong effect on the optimization. Building construction characteristics were found to impact building passive thermal storage capacity. It is thus advisable to make sure the construction material is well modeled. Zone temperature setpoint profiles and TES performance are strongly affected by mismatches in internal heat gains, especially when they are underestimated. Since they are a key factor in determining the building cooling load, efforts should be made to keep the internal gain mismatch as small as possible. Efficiencies of the building energy systems affect both zone temperature setpoints and active TES operation because of the coupling of the base chiller for building precooling and the icemaking TES chiller. Relative efficiencies of the base and TES chillers will determine the balance of operation of the two chillers. The impact of mismatch in this category may be significant. Next, a parametric analysis was conducted to assess the effects of building mass, utility rate, building location and season, thermal comfort, central plant capacities, and an economizer on the cost saving performance of optimal control for active and passive building thermal storage inventory. The key findings are: (1) Heavy-mass buildings, strong-incentive time-of-use electrical utility rates, and large on-peak cooling loads will likely lead to attractive savings resulting from optimal combined thermal storage control. (2) By using economizer to take advantage of the cool fresh air during the night, the building electrical cost can be reduced by using less mechanical cooling. (3) Larger base chiller and active thermal storage capacities have the potential of shifting more cooling loads to off-peak hours and thus higher savings can be achieved. (4) Optimal combined thermal storage control with a thermal comfort penalty included in the objective function can improve the thermal comfort levels of building occupants when compared to the non-optimized base case. Lab testing conducted in the Larson HVAC Laboratory during Phase 2 showed that the EnergyPlus-based simulation was a surprisingly accurate prediction of the experiment. Therefore, actual savings of building energy costs can be expected by applying optimal controls from simulation results.« less
Data analytics and optimization of an ice-based energy storage system for commercial buildings
Luo, Na; Hong, Tianzhen; Li, Hui; ...
2017-07-25
Ice-based thermal energy storage (TES) systems can shift peak cooling demand and reduce operational energy costs (with time-of-use rates) in commercial buildings. The accurate prediction of the cooling load, and the optimal control strategy for managing the charging and discharging of a TES system, are two critical elements to improving system performance and achieving energy cost savings. This study utilizes data-driven analytics and modeling to holistically understand the operation of an ice–based TES system in a shopping mall, calculating the system’s performance using actual measured data from installed meters and sensors. Results show that there is significant savings potential whenmore » the current operating strategy is improved by appropriately scheduling the operation of each piece of equipment of the TES system, as well as by determining the amount of charging and discharging for each day. A novel optimal control strategy, determined by an optimization algorithm of Sequential Quadratic Programming, was developed to minimize the TES system’s operating costs. Three heuristic strategies were also investigated for comparison with our proposed strategy, and the results demonstrate the superiority of our method to the heuristic strategies in terms of total energy cost savings. Specifically, the optimal strategy yields energy costs of up to 11.3% per day and 9.3% per month compared with current operational strategies. A one-day-ahead hourly load prediction was also developed using machine learning algorithms, which facilitates the adoption of the developed data analytics and optimization of the control strategy in a real TES system operation.« less
Data analytics and optimization of an ice-based energy storage system for commercial buildings
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luo, Na; Hong, Tianzhen; Li, Hui
Ice-based thermal energy storage (TES) systems can shift peak cooling demand and reduce operational energy costs (with time-of-use rates) in commercial buildings. The accurate prediction of the cooling load, and the optimal control strategy for managing the charging and discharging of a TES system, are two critical elements to improving system performance and achieving energy cost savings. This study utilizes data-driven analytics and modeling to holistically understand the operation of an ice–based TES system in a shopping mall, calculating the system’s performance using actual measured data from installed meters and sensors. Results show that there is significant savings potential whenmore » the current operating strategy is improved by appropriately scheduling the operation of each piece of equipment of the TES system, as well as by determining the amount of charging and discharging for each day. A novel optimal control strategy, determined by an optimization algorithm of Sequential Quadratic Programming, was developed to minimize the TES system’s operating costs. Three heuristic strategies were also investigated for comparison with our proposed strategy, and the results demonstrate the superiority of our method to the heuristic strategies in terms of total energy cost savings. Specifically, the optimal strategy yields energy costs of up to 11.3% per day and 9.3% per month compared with current operational strategies. A one-day-ahead hourly load prediction was also developed using machine learning algorithms, which facilitates the adoption of the developed data analytics and optimization of the control strategy in a real TES system operation.« less
Cost and fuel consumption per nautical mile for two engine jet transports using OPTIM and TRAGEN
NASA Technical Reports Server (NTRS)
Wiggs, J. F.
1982-01-01
The cost and fuel consumption per nautical mile for two engine jet transports are computed using OPTIM and TRAGEN. The savings in fuel and direct operating costs per nautical mile for each of the different types of optimal trajectories over a standard profile are shown.
Interpreting cost of ownership for mix-and-match lithography
NASA Astrophysics Data System (ADS)
Levine, Alan L.; Bergendahl, Albert S.
1994-05-01
Cost of ownership modeling is a critical and emerging tool that provides significant insight into the ways to optimize device manufacturing costs. The development of a model to deal with a particular application, mix-and-match lithography, was performed in order to determine the level of cost savings and the optimum ways to create these savings. The use of sensitivity analysis with cost of ownership allows the user to make accurate trade-offs between technology and cost. The use and interpretation of the model results are described in this paper. Parameters analyzed include several manufacturing considerations -- depreciation, maintenance, engineering and operator labor, floorspace, resist, consumables and reticles. Inherent in this study is the ability to customize this analysis for a particular operating environment. Results demonstrate the clear advantages of a mix-and-match approach for three different operating environments. These case studies also demonstrate various methods to efficiently optimize cost savings strategies.
Advanced Cogeneration Technology Economic Optimization Study (ACTEOS)
NASA Technical Reports Server (NTRS)
Nanda, P.; Ansu, Y.; Manuel, E. H., Jr.; Price, W. G., Jr.
1980-01-01
The advanced cogeneration technology economic optimization study (ACTEOS) was undertaken to extend the results of the cogeneration technology alternatives study (CTAS). Cost comparisons were made between designs involving advanced cogeneration technologies and designs involving either conventional cogeneration technologies or not involving cogeneration. For the specific equipment cost and fuel price assumptions made, it was found that: (1) coal based cogeneration systems offered appreciable cost savings over the no cogeneration case, while systems using coal derived liquids offered no costs savings; and (2) the advanced cogeneration systems provided somewhat larger cost savings than the conventional systems. Among the issues considered in the study included: (1) temporal variations in steam and electric demands; (2) requirements for reliability/standby capacity; (3) availability of discrete equipment sizes; (4) regional variations in fuel and electricity prices; (5) off design system performance; and (6) separate demand and energy charges for purchased electricity.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Witt, Adam M; Smith, Brennan T
Small hydropower plants supply reliable renewable energy to the grid, though few new plants have been developed in the Unites States over the past few decades due to complex environmental challenges and poor project economics. This paper describes the current landscape of small hydropower development, and introduces a new approach to facility design that co-optimizes the extraction of hydroelectric power from a stream with other important environmental functions such as fish, sediment, and recreational passage. The approach considers hydropower facilities as an integrated system of standardized interlocking modules, designed to sustain stream functions, generate power, and interface with the streambed.more » It is hypothesized that this modular eco-design approach, when guided by input from the broader small hydropower stakeholder community, can lead to cost savings across the facility, reduced licensing and approval timelines, and ultimately, to enhanced resiliency through improved environmental performance over the lifetime of the project.« less
SVM classifier on chip for melanoma detection.
Afifi, Shereen; GholamHosseini, Hamid; Sinha, Roopak
2017-07-01
Support Vector Machine (SVM) is a common classifier used for efficient classification with high accuracy. SVM shows high accuracy for classifying melanoma (skin cancer) clinical images within computer-aided diagnosis systems used by skin cancer specialists to detect melanoma early and save lives. We aim to develop a medical low-cost handheld device that runs a real-time embedded SVM-based diagnosis system for use in primary care for early detection of melanoma. In this paper, an optimized SVM classifier is implemented onto a recent FPGA platform using the latest design methodology to be embedded into the proposed device for realizing online efficient melanoma detection on a single system on chip/device. The hardware implementation results demonstrate a high classification accuracy of 97.9% and a significant acceleration factor of 26 from equivalent software implementation on an embedded processor, with 34% of resources utilization and 2 watts for power consumption. Consequently, the implemented system meets crucial embedded systems constraints of high performance and low cost, resources utilization and power consumption, while achieving high classification accuracy.
NASA Technical Reports Server (NTRS)
Aljabri, Abdullah S.
1988-01-01
High speed subsonic transports powered by advanced propellers provide significant fuel savings compared to turbofan powered transports. Unfortunately, however, propfans must operate in aircraft-induced nonuniform flow fields which can lead to high blade cyclic stresses, vibration and noise. To optimize the design and installation of these advanced propellers, therefore, detailed knowledge of the complex flow field is required. As part of the NASA Propfan Test Assessment (PTA) program, a 1/9 scale semispan model of the Gulfstream II propfan test-bed aircraft was tested in the NASA-Lewis 8 x 6 supersonic wind tunnel to obtain propeller flow field data. Detailed radial and azimuthal surveys were made to obtain the total pressure in the flow and the three components of velocity. Data was acquired for Mach numbers ranging from 0.6 to 0.85. Analytical predictions were also made using a subsonic panel method, QUADPAN. Comparison of wind-tunnel measurements and analytical predictions show good agreement throughout the Mach range.
Yang, Hang; Zhang, Yongxin; Zheng, Chenghang; Wu, Xuecheng; Chen, Linghong; Gao, Xiang; Fu, Joshua S
2018-05-10
The pollutant abatement systems are widely applied in the coal-fired power sector and the energy consumption was considered an important part of the auxiliary power. An energy consumption analysis and assessment model of pollutant abatement systems in a power unit was developed based on the dynamic parameters and technology. The energy consumption of pollutant abatement systems in a 1000 MW coal-fired power unit which meet the ultra-low emission limits and the factors of operating parameters including unit load and inlet concentration of pollutants on the operating power were analyzed. The results show that the total power consumption of the pollutant abatement systems accounted for 1.27% of the gross power generation during the monitoring period. The WFGD system consumed 67% of the rate while the SCR and ESP systems consumed 8.9% and 24.1%. The power consumption rate of pollutant abatement systems decreased with the increase of unit load and increased with the increase of the inlet concentration of pollutants. The operation adjustment was also an effective method to increase the energy efficiency. For example, the operation adjustment of slurry circulation pumps could promote the energy-saving operation of WFGD system. Implication Statement The application of pollutant abatement technologies increases the internal energy consumption of the power plant, which will lead to an increase of power generation costs. The real-time energy consumption of the different pollutant abatement systems in a typical power unit is analyzed based on the dynamic operating data. Further, the influence of different operating parameters on the operating power of the system and the possible energy-saving potential are analyzed.
Who's in the business of saving lives?
Lee Chang, Pepe
2006-10-01
There are individuals, including children, dying needlessly in poverty-stricken third world countries. Many of these deaths could be prevented if pharmaceutical companies provided the drugs needed to save their lives. Some believe that because pharmaceutical companies have the power to save lives, and because they can do so with little effort, they have a special obligation. I argue that there is no distinction, with respect to obligations and responsibilities, between pharmaceutical companies and other types of companies. As a result, to hold pharmaceutical companies especially responsible for saving lives in third world countries is unjustified.
[Cost-effectiveness of breast cancer screening policies in Mexico].
Valencia-Mendoza, Atanacio; Sánchez-González, Gilberto; Bautista-Arredondo, Sergio; Torres-Mejía, Gabriela; Bertozzi, Stefano M
2009-01-01
Generate cost-effectiveness information to allow policy makers optimize breast cancer (BC) policy in Mexico. We constructed a Markov model that incorporates four interrelated processes of the disease: the natural history; detection using mammography; treatment; and other competing-causes mortality, according to which 13 different strategies were modeled. Strategies (starting age, % of coverage, frequency in years)= (48, 25, 2), (40, 50, 2) and (40, 50, 1) constituted the optimal method for expanding the BC program, yielding 75.3, 116.4 and 171.1 thousand pesos per life-year saved, respectively. The strategies included in the optimal method for expanding the program produce a cost per life-year saved of less than two times the GNP per capita and hence are cost-effective according to WHO Commission on Macroeconomics and Health criteria.
Cost-Based Optimization of a Papermaking Wastewater Regeneration Recycling System
NASA Astrophysics Data System (ADS)
Huang, Long; Feng, Xiao; Chu, Khim H.
2010-11-01
Wastewater can be regenerated for recycling in an industrial process to reduce freshwater consumption and wastewater discharge. Such an environment friendly approach will also lead to cost savings that accrue due to reduced freshwater usage and wastewater discharge. However, the resulting cost savings are offset to varying degrees by the costs incurred for the regeneration of wastewater for recycling. Therefore, systematic procedures should be used to determine the true economic benefits for any water-using system involving wastewater regeneration recycling. In this paper, a total cost accounting procedure is employed to construct a comprehensive cost model for a paper mill. The resulting cost model is optimized by means of mathematical programming to determine the optimal regeneration flowrate and regeneration efficiency that will yield the minimum total cost.
Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.).
Petigny, Loïc; Périno-Issartier, Sandrine; Wajsman, Joël; Chemat, Farid
2013-03-12
Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality.
Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.)
Petigny, Loïc; Périno-Issartier, Sandrine; Wajsman, Joël; Chemat, Farid
2013-01-01
Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality. PMID:23481637
Development of a pump-turbine runner based on multiobjective optimization
NASA Astrophysics Data System (ADS)
Xuhe, W.; Baoshan, Z.; Lei, T.; Jie, Z.; Shuliang, C.
2014-03-01
As a key component of reversible pump-turbine unit, pump-turbine runner rotates at pump or turbine direction according to the demand of power grid, so higher efficiencies under both operating modes have great importance for energy saving. In the present paper, a multiobjective optimization design strategy, which includes 3D inverse design method, CFD calculations, response surface method (RSM) and multiobjective genetic algorithm (MOGA), is introduced to develop a model pump-turbine runner for middle-high head pumped storage plant. Parameters that controlling blade shape, such as blade loading and blade lean angle at high pressure side are chosen as input parameters, while runner efficiencies under both pump and turbine modes are selected as objective functions. In order to validate the availability of the optimization design system, one runner configuration from Pareto front is manufactured for experimental research. Test results show that the highest unit efficiency is 91.0% under turbine mode and 90.8% under pump mode for the designed runner, of which prototype efficiencies are 93.88% and 93.27% respectively. Viscous CFD calculations for full passage model are also conducted, which aim at finding out the hydraulic improvement from internal flow analyses.
Carbon-Carbon Recuperators in Closed-Brayton-Cycle Space Power Systems
NASA Technical Reports Server (NTRS)
Barrett, Michael J.; Johnson, Paul K.; Naples, Andrew G.
2006-01-01
The feasibility of using carbon-carbon (C-C) recuperators in conceptual closed-Brayton-cycle space power conversion systems was assessed. Recuperator performance expectations were forecast based on notional thermodynamic cycle state values for potential planetary missions. Resulting thermal performance, mass and volume for plate-fin C-C recuperators were estimated and quantitatively compared with values for conventional offset-strip-fin metallic designs. Mass savings of 30 to 60 percent were projected for C-C recuperators with effectiveness greater than 0.9 and thermal loads from 25 to 1400 kWt. The smaller thermal loads corresponded with lower mass savings; however, 60 percent savings were forecast for all loads above 300 kWt. System-related material challenges and compatibility issues were also discussed.
Optimal savings and health spending over the life cycle.
Fioroni, Tamara
2010-08-01
This paper investigates the relationship between saving and health spending in a two-period overlapping generations economy. Individuals work in the first period of life and live in retirement in old age. Health spending is an activity that increases quality of life and longevity. Empirical evidence shows that both health spending and saving behave as luxury goods but their behaviour differs markedly according to the level of per capita GDP. The share of saving on GDP has a concave shape with respect to per capita GDP, whereas the share of health spending on GDP increases more than proportionally with respect to per capita GDP. The ratio of saving to spending is nonlinear with respect to income, i.e. first increasing and then decreasing. This ratio, in the proposed model, is equal to the ratio between the elasticity of the utility function with respect to saving and the elasticity of the utility function with respect to health.
Water Injection on Commercial Aircraft to Reduce Airport Nitrogen Oxides
NASA Technical Reports Server (NTRS)
Daggett, David L.; Hendricks, Robert C.; Fucke, Lars; Eames, David J. H.
2010-01-01
The potential nitrogen oxide (NO(x) reductions, cost savings, and performance enhancements identified in these initial studies of waterinjection technology strongly suggest that it be further pursued. The potential for engine maintenance cost savings from this system should make it very attractive to airline operators and assure its implementation. Further system tradeoff studies and engine tests are needed to answer the optimal system design question. Namely, would a low-risk combustor injection system with 70- to 90-percent NO(x) reduction be preferable, or would a low-pressure compressor (LPC) misting system with only 50-percent NO(x) reduction but larger turbine inlet temperature reductions be preferable? The low-pressure compressor injection design and operability issues identified in the report need to be addressed because they might prevent implementation of the LPC type of water-misting system. If water-injection technology challenges are overcome, any of the systems studied would offer dramatic engine NO(x) reductions at the airport. Coupling this technology with future emissions-reduction technologies, such as fuel-cell auxiliary power units will allow the aviation sector to address the serious challenges of environmental stewardship, and NO(x) emissions will no longer be an issue at airports.
Synchronous Firefly Algorithm for Cluster Head Selection in WSN
Baskaran, Madhusudhanan; Sadagopan, Chitra
2015-01-01
Wireless Sensor Network (WSN) consists of small low-cost, low-power multifunctional nodes interconnected to efficiently aggregate and transmit data to sink. Cluster-based approaches use some nodes as Cluster Heads (CHs) and organize WSNs efficiently for aggregation of data and energy saving. A CH conveys information gathered by cluster nodes and aggregates/compresses data before transmitting it to a sink. However, this additional responsibility of the node results in a higher energy drain leading to uneven network degradation. Low Energy Adaptive Clustering Hierarchy (LEACH) offsets this by probabilistically rotating cluster heads role among nodes with energy above a set threshold. CH selection in WSN is NP-Hard as optimal data aggregation with efficient energy savings cannot be solved in polynomial time. In this work, a modified firefly heuristic, synchronous firefly algorithm, is proposed to improve the network performance. Extensive simulation shows the proposed technique to perform well compared to LEACH and energy-efficient hierarchical clustering. Simulations show the effectiveness of the proposed method in decreasing the packet loss ratio by an average of 9.63% and improving the energy efficiency of the network when compared to LEACH and EEHC. PMID:26495431
Anticipated detection of favorable periods for wind energy production by means of information theory
NASA Astrophysics Data System (ADS)
Vogel, Eugenio; Saravia, Gonzalo; Kobe, Sigismund; Schumann, Rolf; Schuster, Rolf
Managing the electric power produced by different sources requires mixing the different response times they present. Thus, for instance, coal burning presents large time lags until operational conditions are reached while hydroelectric generation can react in a matter of some seconds or few minutes to reach the desired productivity. Wind energy production (WEP) can be instantaneously fed to the network to save fuels with low thermal inertia (gas burning for instance), but this source presents sudden variations within few hours. We report here for the first time a method based on information theory to handle WEP. This method has been successful in detecting dynamical changes in magnetic transitions and variations of stock markets. An algorithm called wlzip based on information recognition is used to recognize the information content of a time series. We make use of publically available energy data in Germany to simulate real applications. After a calibration process the system can recognize directly on the WEP data the onset of favorable periods of a desired strength. Optimization can lead to a few hours of anticipation which is enough to control the mixture of WEP with other energy sources, thus saving fuels.
Optimizing the U.S. Electric System with a High Penetration of Renewables
NASA Astrophysics Data System (ADS)
Corcoran, B. A.; Jacobson, M. Z.
2012-12-01
As renewable energy generators are increasingly being installed throughout the U.S., there is growing interest in interconnecting diverse renewable generators (primarily wind and solar) across large geographic areas through an enhanced transmission system. This reduces variability in the aggregate power output, increases system reliability, and allows for the development of the best overall group of renewable technologies and sites to meet the load. Studies are therefore needed to determine the most efficient and economical plan to achieve large area interconnections in a future electric system with a high penetration of renewables. This research quantifies the effects of aggregating electric load and, separately, electric load together with diverse renewable generation throughout the ten Federal Energy Regulatory Commission (FERC) regions in the contiguous U.S. The effects of aggregating electric load alone -- including generator capacity capital cost savings, load energy shift operating cost savings, reserve requirement cost savings, and transmission costs -- were calculated for various groupings of FERC regions using 2006 data. Transmission costs outweighed cost savings due to aggregation in nearly all cases. East-west transmission layouts had the highest overall cost, and interconnecting ERCOT to adjacent FERC regions resulted in increased costs, both due to limited existing transmission capacity. Scenarios consisting of smaller aggregation groupings had the lowest overall cost. This analysis found no economic case for further aggregation of load alone within the U.S., except possibly in the West and Northwest. If aggregation of electric load is desired, then small, regional consolidations yield the lowest overall system cost. Next, the effects of aggregating electric load together with renewable electricity generation are being quantified through the development and use of an optimization tool in AMPL (A Mathematical Programming Language). This deterministic linear program solves for the least-cost organizational structure and system (generator, transmission, storage, and reserve requirements) for a highly renewable U.S. electric grid. The analysis will 1) examine a highly renewable 2006 electric system, and 2) create a "roadmap" from the existing 2006 system to a highly renewable system in 2030, accounting for projected price and demand changes and generator retirements based on age and environmental regulations. Ideally, results from this study will offer insight for a federal renewable energy policy (such as a renewable portfolio standard) and how to best organize regions for transmission planning.
12 CFR 550.20 - What are fiduciary powers?
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false What are fiduciary powers? 550.20 Section 550.20 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS § 550.20 What are fiduciary powers? Fiduciary powers are the authority that OTS...
12 CFR 550.20 - What are fiduciary powers?
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false What are fiduciary powers? 550.20 Section 550.20 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS § 550.20 What are fiduciary powers? Fiduciary powers are the authority that OTS...
12 CFR 550.20 - What are fiduciary powers?
Code of Federal Regulations, 2012 CFR
2012-01-01
... 12 Banks and Banking 6 2012-01-01 2012-01-01 false What are fiduciary powers? 550.20 Section 550.20 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS § 550.20 What are fiduciary powers? Fiduciary powers are the authority that OTS...
A Novel Energy Saving Algorithm with Frame Response Delay Constraint in IEEE 802.16e
NASA Astrophysics Data System (ADS)
Nga, Dinh Thi Thuy; Kim, Mingon; Kang, Minho
Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our proposed algorithm through analytical results and simulation results suggest that our algorithm provide a potential guidance to energy saving.
Managing the equipment service life in rendering engineering support to NPP operation
NASA Astrophysics Data System (ADS)
Ryasnyy, S. I.
2015-05-01
Apart from subjecting metal to nondestructive testing and determining its actual state, which are the traditional methods used for managing the service life of NPP equipment during its operation, other approaches closely linked with rendering engineering support to NPP operation have emerged in recent decades, which, however, have been covered in publications to a lesser extent. Service life management matters occupy the central place in the structure of engineering support measures. Application of the concept of repairing NPP equipment based on assessing its technical state and the risk of its failure makes it possible to achieve significantly smaller costs for maintenance and repairs and produce a larger amount of electricity due to shorter planned outages. Decreasing the occurrence probability of a process-related abnormality through its prediction is a further development of techniques for monitoring the technical state of equipment and systems. The proposed and implemented procedure for predicting the occurrence of process-related deviations from normal NPP operation opens the possibility to record in the online mode the trends in changes of process parameters that are likely to lead to malfunctions in equipment operation and to reduce the probability of power unit unloading when an abnormal technical state of equipment occurs and develops by recording changes in the state at an early stage and taking timely corrective measures. The article presents the structure of interconnections between the objectives and conditions of adjustment and commissioning tests, in which the management of equipment service life (saving and optimizing the service life) occupies the central place. Special attention is paid to differences in resource saving and optimization measures.
Research on Power Loss of Continuously Variable Transmission Based on Driving Cycles
NASA Astrophysics Data System (ADS)
Fu, Bing; Zhou, Yunshan; Cao, Chenglong; Li, Quan; Zhang, Feitie
2018-01-01
In order to further enhance the fuel economy of vehicles with continuously variable transmission (CVT), a CVT power loss model under dynamic condition is established based on the power loss model of each transmission component and the vehicle dynamic model. With driving cycles 10-15, NEDC and US06 as input, the distribution of CVT power loss and the influence of the main losses to vehicle fuel economy are analysed. The results show that the variation loss, oil pump loss and torque converter loss are the main losses of CVT power loss under driving cycles, and the metal belt and oil pump have relatively larger fuel saving potential. At low speed reducing the pump loss is more effective to fuel saving, while at high speed reducing the variation loss is more effective.
Cold air systems: Sleeping giant
DOE Office of Scientific and Technical Information (OSTI.GOV)
MacCracken, C.D.
1994-04-01
This article describes how cold air systems help owners increase the profits from their buildings by reducing electric costs and improving indoor air quality through lower relative humidity levels. Cold air distribution involves energy savings, cost savings, space savings, greater comfort, cleaner air, thermal storage, tighter ducting, coil redesign, lower relative humidities, retrofitting, and improved indoor air quality (IAQ). It opens a door for architects, engineers, owners, builders, environmentalists, retrofitters, designers, occupants, and manufacturers. Three things have held up cold air's usage: multiple fan-powered boxes that ate up the energy savings of primary fans. Cold air room diffusers that providedmore » inadequate comfort. Condensation from ducts, boxes, and diffusers. Such problems have been largely eliminated through research and development by utilities and manufacturers. New cold air diffusers no longer need fan powered boxes. It has also been found that condensation is not a concern so long as the ducts are located in air conditioned space, such as drop ceilings or central risers, where relative humidity falls quickly during morning startup.« less
Reducing power usage on demand
NASA Astrophysics Data System (ADS)
Corbett, G.; Dewhurst, A.
2016-10-01
The Science and Technology Facilities Council (STFC) datacentre provides large- scale High Performance Computing facilities for the scientific community. It currently consumes approximately 1.5MW and this has risen by 25% in the past two years. STFC has been investigating leveraging preemption in the Tier 1 batch farm to save power. HEP experiments are increasing using jobs that can be killed to take advantage of opportunistic CPU resources or novel cost models such as Amazon's spot pricing. Additionally, schemes from energy providers are available that offer financial incentives to reduce power consumption at peak times. Under normal operating conditions, 3% of the batch farm capacity is wasted due to draining machines. By using preempt-able jobs, nodes can be rapidly made available to run multicore jobs without this wasted resource. The use of preempt-able jobs has been extended so that at peak times machines can be hibernated quickly to save energy. This paper describes the implementation of the above and demonstrates that STFC could in future take advantage of such energy saving schemes.
Evaluation of all-electric secondary power for transport aircraft
NASA Technical Reports Server (NTRS)
Murray, W. E.; Feiner, L. J.; Flores, R. R.
1992-01-01
This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E; $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.
Evaluation of all-electric secondary power for transport aircraft
NASA Astrophysics Data System (ADS)
Murray, W. E.; Feiner, L. J.; Flores, R. R.
1992-01-01
This report covers a study by Douglas Aircraft Company (DAC) of electrical power systems for advanced transport aircraft based upon an all-electric design concept. The concept would eliminate distributed hydraulic and pneumatic secondary power systems, and feature an expanded secondary electrical power system redesigned to supply power to the loads customarily supplied by hydraulic or pneumatic power. The initial study was based on an advanced 20-kHz electrical power transmission and distribution system, using a system architecture supplied by NASA-Lewis Research Center for twin-engine aircraft with many advanced power conversion concepts. NASA-LeRC later requested DAC to refocus the study on 400-Hz secondary power distribution. Subsequent work was based on a three-engine MD-11 aircraft, selected by DAC as a baseline system design that would provide data for the comparative cost/benefit analysis. The study concluded that the 20-kHz concept produced many expected benefits, and that the all-electric trijet weight savings on hardware redesign would be 2,304 pounds plus a 2.1-percent fuel reduction and resized for a total weight reduction of 11,000 pounds. Cost reductions for a fleet of 800 aircraft in a 15-year production program were estimated at $76.71 million for RDT&E $2.74 million per aircrat for production; $9.84 million for nonrecurring expenses; $120,000 per aircraft for product support; and $300,000 per aircraft per year for operating and maintenance costs, giving a present value of $1.914 billion saved or a future value of $10.496 billion saved.
NASA Astrophysics Data System (ADS)
Dharmalingam, Gnanaprakash; Carpenter, Michael A.
2015-05-01
Monitoring polluting gases such as CO and NOx emitted from gas turbines in power plants and aircraft is important, in order to both reduce the effects of such gases on the environment as well as to optimize the performance of the respective power system. Fuel cost savings as well as a reduced environmental impact can be realized if air traffic utilized next generation jet turbines with an emission/performance control sensing system. These monitoring systems must be sensitive and selective to gases as well as be reliable and stable under harsh environmental conditions where the operation temperatures are in excess of 500 °C within a highly reactive environment. In this work, plasmonics based chemical sensors with nanocomposites of a combination of gold nano particles and Yttria Stabilized Zirconia (YSZ) has enabled the sensitive (PPM) and stable detection (100s of hrs.) of H2, NO2 and CO at temperatures of 500 °C. Selectivity remains a challenging parameter to optimize and a layer by layer sputter deposition approach has been recently demonstrated to modify the resulting sensing properties through a change in the morphology of the deposited films. It is expected that further enhancements would be realized through control of the shape and geometry of the catalytically active Au nanoparticles. This level of control has been realized through the use of electron beam lithography to fabricate nanocomposite arrays. Sensing results towards the detection of H2 will be highlighted with specific concerns related to optimization of these nanorod arrays detailed.
Code of Federal Regulations, 2010 CFR
2010-01-01
... procedures in exercising fiduciary powers? 550.140 Section 550.140 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers § 550.140 Must I adopt and follow written policies and procedures in exercising fiduciary powers? You...
12 CFR 550.20 - What are fiduciary powers?
Code of Federal Regulations, 2014 CFR
2014-01-01
... 12 Banks and Banking 6 2014-01-01 2012-01-01 true What are fiduciary powers? 550.20 Section 550.20 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS § 550.20 What are fiduciary powers? Fiduciary powers are the authority that OTS permits you to...
Energy management system saves $250,000 + fuel -with 4-mo payback
DOE Office of Scientific and Technical Information (OSTI.GOV)
Massey, C.L.; Robe, K.
1980-09-01
Innovations made at Hershey Chocolate Company's Oakdale, California plant eliminated simultaneous cool-reheat-cycles by incorporating dead band controls into existing HVAC systems. Calculated savings of the project are about 90% of former heating and cooling energy usage for HVAC operation. Electric power savings amount to about $75,000/y, and natural gas savings about $185,000/y, using 1980 fuel costs, with an approximate 4-month payback. Because of the reduced demand for chilled water, a smaller water chiller carries full plant load for 4 to 5 months of the year without operating two existing 500-ton units.
Design and implementation of a simple acousto optic dual control circuit
NASA Astrophysics Data System (ADS)
Li, Biqing; Li, Zhao
2017-04-01
This page proposed a simple light control circuit which designed by using power supply circuit, sonic circuits, electric circuit and delay circuit four parts. The main chip for CD4011, have inside of the four and to complete the sonic or circuit, electric, delay logic circuit. During the day, no matter how much a pedestrian voice, is ever shine light bulb. Dark night, circuit in a body to make the microphone as long as testing noise, and will automatically be bright for pedestrians lighting, several minutes after the automatic and put out, effective energy saving. Applicable scope and the working principle of the circuit principle diagram and given device parameters selection, power saving effect is obvious, at the same time greatly reduce the maintenance quantity, saving money, use effect is good.
Are cooler surfaces a cost-effect mitigation of urban heat islands?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pomerantz, Melvin
Much research has gone into technologies to mitigate urban heat islands by making urban surfaces cooler by increasing their albedos. To be practical, the benefit of the technology must be greater than its cost. Here, this report provides simple methods for quantifying the maxima of some benefits that albedo increases may provide. The method used is an extension of an earlier paper that estimated the maximum possible electrical energy saving achievable in an entire city in a year by a change of albedo of its surfaces. The present report estimates the maximum amounts and monetary savings of avoided CO 2more » emissions and the decreases in peak power demands. As examples, for several warm cities in California, a 0.2 increase in albedo of pavements is found to reduce CO 2 emissions by < 1 kg per m 2 per year. At the current price of CO 2 reduction in California, the monetary saving is < US$ 0.01 per year per m 2 modified. The resulting maximum peak-power reductions are estimated to be < 7% of the base power of the city. In conclusion, the magnitudes of the savings are such that decision-makers should choose carefully which urban heat island mitigation techniques are cost effective.« less
Are cooler surfaces a cost-effect mitigation of urban heat islands?
Pomerantz, Melvin
2017-04-20
Much research has gone into technologies to mitigate urban heat islands by making urban surfaces cooler by increasing their albedos. To be practical, the benefit of the technology must be greater than its cost. Here, this report provides simple methods for quantifying the maxima of some benefits that albedo increases may provide. The method used is an extension of an earlier paper that estimated the maximum possible electrical energy saving achievable in an entire city in a year by a change of albedo of its surfaces. The present report estimates the maximum amounts and monetary savings of avoided CO 2more » emissions and the decreases in peak power demands. As examples, for several warm cities in California, a 0.2 increase in albedo of pavements is found to reduce CO 2 emissions by < 1 kg per m 2 per year. At the current price of CO 2 reduction in California, the monetary saving is < US$ 0.01 per year per m 2 modified. The resulting maximum peak-power reductions are estimated to be < 7% of the base power of the city. In conclusion, the magnitudes of the savings are such that decision-makers should choose carefully which urban heat island mitigation techniques are cost effective.« less
12 CFR 558.1 - Procedure upon taking possession.
Code of Federal Regulations, 2011 CFR
2011-01-01
.... (a) The conservator or receiver for a Federal or state savings association shall take possession of... conservator or receiver shall immediately: (1) Take possession of the savings association's books, records and... association, that the conservator or receiver has succeeded to all rights, titles, powers and privileges of...
12 CFR 558.1 - Procedure upon taking possession.
Code of Federal Regulations, 2010 CFR
2010-01-01
.... (a) The conservator or receiver for a Federal or state savings association shall take possession of... conservator or receiver shall immediately: (1) Take possession of the savings association's books, records and... association, that the conservator or receiver has succeeded to all rights, titles, powers and privileges of...
NASA Astrophysics Data System (ADS)
Rubio, Ernesto Javier
Currently, there is enormous interest in research, development and optimization of the combustion processes for energy harvesting. Recent statistical and economic analyses estimated that by improving the coal-based firing/combustion processes in the power plants, savings up to $450-500 million yearly can be achieved. Advanced sensors and controls capable of withstanding extreme environments such as high temperatures, highly corrosive atmospheres, and high pressures are critical to such efficiency enhancement and cost savings. For instance, optimization of the combustion processes in power generation systems can be achieved by sensing, monitoring and control of oxygen, which is a measure of the completeness of the process and can lead to enhanced efficiency and reduced greenhouse gas emissions. However, despite the fact that there exists a very high demand for advanced sensors, the existing technologies suffer from poor 'response and recovery times' and 'long-term stability.' Motivated by the aforementioned technological challenges, the present work was focused on high-temperature (≥700 °C) oxygen sensors for application in power generation systems. The objective of the present work is to investigate nanostructured gallium oxide (2O3) based sensors for oxygen sensing, where we propose to conduct in-depth exploration of the role of refractory metal (tungsten, W, in this case) doping into 2O 3 to enhance the sensitivity, selectivity, stability ("3S" criteria) and reliability of such sensors while keeping cost economical. Tungsten (W) doped gallium oxide (2O3) thin films were deposited via rf-magnetron co-sputtering of W-metal and Ga2O3-ceramic targets. Films were produced by varying the sputtering power applied to the W-target in order to achieve variable W content into 2O3 films while substrate temperature was kept constant at 500 °C. Chemical composition, chemical valence states, microstructure and crystal structure of as-grown and post-annealed W-doped 2O3 films were evaluated as a function of W-content. The structural analyses indicate the formation of monoclinic beta-phase 2O3 in as-grown W-doped 2O3 films for all W-content. Thermally induced secondary phase (W-oxide) formation was observed after the annealing process. Chemical analysis demonstrates the increasing W atomic percentage in the films with increasing sputtering power, whereas the main metallic ionic species for the films are W6+ and Ga3+. Evidence of W interdiffusion due to the annealing process is presented, and the mechanism of diffusion is discussed. Surface morphology of the films is also discussed, and the transition to mesoporous surface is observed after annealing. Finally, the oxygen sensor performance evaluation demonstrated that the W-incorporated 2O3 exhibits improved response time compared to intrinsic 2O3 based oxygen sensors.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Konopacki, S.; Akbari, H.
2000-03-01
In 1997, the US Environmental Protection Agency (EPA) established the ''Heat Island Reduction Initiative'', to quantify the potential benefits of Heat Island Reduction (HIR) strategies (i.e., shade trees, reflective roofs, reflective pavements and urban vegetation) to reduce cooling energy use in buildings, lower the ambient air temperature and improve urban air quality in cities, and reduce CO2 emissions from power plants. Under this initiative, the Urban Heat Island Pilot Project (UHIPP) was created with the objective to investigate the potential of HIR strategies in residential and commercial buildings in three initial UHIPP cities: Baton Rouge, Sacramento and Salt Lake City.more » This paper summarizes our efforts to calculate the annual energy savings, peak power avoidance and annual C02 reduction of HIR strategies in the three initial cities. In this analysis, we focused on three building types that offer most savings potential: single-family residence, office and retail store. Each building type was characterized in detail by old or new construction and with a gas furnace or an electric heat pump. We defined prototypical building characteristics for each building type and simulated the impact of HIR strategies on building cooling and heating energy use and peak power demand using the DOE-2.IE model. Our simulations included the impact of (1) strategically-placed shade trees near buildings [direct effect], (2) use of high-albedo roofing material on building [direct effect], (3) combined strategies I and 2 [direct effect], (4) urban reforestation with high-albedo pavements and building surfaces [indirect effect] and (5) combined strategies 1, 2 and 4 [direct and indirect effects]. We then estimated the total roof area of air-conditioned buildings in each city using readily obtainable data to calculate the metropolitan-wide impact of HIR strategies. The results show, that in Baton Rouge, potential annual energy savings of $15M could be realized by rate-payers from the combined direct and indirect effects of HIR strategies. Additionally, peak power avoidance is estimated at 133 MW and the reduction in annual carbon emissions at 41 kt. In Sacramento, the potential annual energy savings is estimated at $26M, with an avoidance of 486 MW in peak power and a reduction in annual carbon of 92 kt. In Salt Lake City, the potential annual energy savings is estimated at $4M, with an avoidance of 85 MW in peak power and a reduction in annual carbon of 20 kt.« less
Channel Deviation-Based Power Control in Body Area Networks.
Van, Son Dinh; Cotton, Simon L; Smith, David B
2018-05-01
Internet enabled body area networks (BANs) will form a core part of future remote health monitoring and ambient assisted living technology. In BAN applications, due to the dynamic nature of human activity, the off-body BAN channel can be prone to deep fading caused by body shadowing and multipath fading. Using this knowledge, we present some novel practical adaptive power control protocols based on the channel deviation to simultaneously prolong the lifetime of wearable devices and reduce outage probability. The proposed schemes are both flexible and relatively simple to implement on hardware platforms with constrained resources making them inherently suitable for BAN applications. We present the key algorithm parameters used to dynamically respond to the channel variation. This allows the algorithms to achieve a better energy efficiency and signal reliability in everyday usage scenarios such as those in which a person undertakes many different activities (e.g., sitting, walking, standing, etc.). We also profile their performance against traditional, optimal, and other existing schemes for which it is demonstrated that not only does the outage probability reduce significantly, but the proposed algorithms also save up to average transmit power compared to the competing schemes.
Performance improvement of long-range surface plasmon structure for use in an all-optical switch
NASA Astrophysics Data System (ADS)
Jandaghian, Ali; Lotfalian, Ali; Kouhkan, Mohsen; Mohajerani, Ezeddin
2017-12-01
This paper presents important parameters in performance of long-range surface plasmon (LRSP) structure (SF4/PVA/silver/PMMA-DR1) that are improved. We select poly(vinyl alcohol) (PVA) as the first dielectric layer due to its water solubility and good optical properties. The thickness of PVA and silver layers is optimized by transfer matrix method based on Fresnel equations. Surface morphologies of PVA and silver surfaces are analyzed by AFM imaging due to their important role in the performance of an LRSP structure. Furthermore, the sensitivity of an all-optical switch based on plasmon is investigated. In order to compare the sensitivity of LRSP and conventional surface plasmon (SP) structures in switching mode, full wide of half maximum, resonance angles, and pump powers of both structures are measured by a custom-made optical setup based on angular interrogation with a precision of 0.01 deg. Finally, we conclude that for creating equal signal levels in both samples, the required pump power for LRSP structure was about three times less than that for conventional SP; thus, these results led to power savings in optical switches.
A Bayesian sequential design with adaptive randomization for 2-sided hypothesis test.
Yu, Qingzhao; Zhu, Lin; Zhu, Han
2017-11-01
Bayesian sequential and adaptive randomization designs are gaining popularity in clinical trials thanks to their potentials to reduce the number of required participants and save resources. We propose a Bayesian sequential design with adaptive randomization rates so as to more efficiently attribute newly recruited patients to different treatment arms. In this paper, we consider 2-arm clinical trials. Patients are allocated to the 2 arms with a randomization rate to achieve minimum variance for the test statistic. Algorithms are presented to calculate the optimal randomization rate, critical values, and power for the proposed design. Sensitivity analysis is implemented to check the influence on design by changing the prior distributions. Simulation studies are applied to compare the proposed method and traditional methods in terms of power and actual sample sizes. Simulations show that, when total sample size is fixed, the proposed design can obtain greater power and/or cost smaller actual sample size than the traditional Bayesian sequential design. Finally, we apply the proposed method to a real data set and compare the results with the Bayesian sequential design without adaptive randomization in terms of sample sizes. The proposed method can further reduce required sample size. Copyright © 2017 John Wiley & Sons, Ltd.
Subsonic flight test evaluation of a performance seeking control algorithm on an F-15 airplane
NASA Technical Reports Server (NTRS)
Gilyard, Glenn B.; Orme, John S.
1992-01-01
The subsonic flight test evaluation phase of the NASA F-15 (powered by F 100 engines) performance seeking control program was completed for single-engine operation at part- and military-power settings. The subsonic performance seeking control algorithm optimizes the quasi-steady-state performance of the propulsion system for three modes of operation. The minimum fuel flow mode minimizes fuel consumption. The minimum thrust mode maximizes thrust at military power. Decreases in thrust-specific fuel consumption of 1 to 2 percent were measured in the minimum fuel flow mode; these fuel savings are significant, especially for supersonic cruise aircraft. Decreases of up to approximately 100 degree R in fan turbine inlet temperature were measured in the minimum temperature mode. Temperature reductions of this magnitude would more than double turbine life if inlet temperature was the only life factor. Measured thrust increases of up to approximately 15 percent in the maximum thrust mode cause substantial increases in aircraft acceleration. The system dynamics of the closed-loop algorithm operation were good. The subsonic flight phase has validated the performance seeking control technology, which can significantly benefit the next generation of fighter and transport aircraft.
NASA Astrophysics Data System (ADS)
Flaschel, Nils; Ariza, Dario; Díez, Sergio; Gerboles, Marta; Gregor, Ingrid-Maria; Jorda, Xavier; Mas, Roser; Quirion, David; Tackmann, Kerstin; Ullan, Miguel
2017-08-01
Micro-channel cooling initially aiming at small-sized high-power integrated circuits is being transferred to the field of high energy physics. Today's prospects of micro-fabricating silicon opens a door to a more direct cooling of detector modules. The challenge in high energy physics is to save material in the detector construction and to cool large areas. In this paper, we are investigating micro-channel cooling as a candidate for a future cooling system for silicon detectors in a generic research and development approach. The work presented in this paper includes the production and the hydrodynamic and thermal testing of a micro-channel equipped prototype optimized to achieve a homogeneous flow distribution. Furthermore, the device was simulated using finite element methods.
12 CFR 550.530 - How do I surrender fiduciary powers?
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false How do I surrender fiduciary powers? 550.530 Section 550.530 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Terminating Fiduciary Activities Surrender of Fiduciary Powers § 550.530...
NASA Astrophysics Data System (ADS)
Veselov, F. V.; Erokhina, I. V.; Makarova, A. S.; Khorshev, A. A.
2017-03-01
The article deals with issues of technical and economic substantiation of priorities and scopes of modernizing the existing thermal power plants (TPPs) in Russia to work out long-term forecasts of the development of the industry. The current situation in the TPP modernization trends is analyzed. The updated initial figures of the capital and operation costs are presented and the obtained estimates of the comparative efficiency of various investment decisions on modernization and equipment replacement at gas-and-oil-burning and coal-fired TPPs with regard to the main zones of the national Unified Power System (UPS) of Russia are cited. The results of optimization of the generating capacity structure underlie a study of alternative TPP modernization strategies that differ in the scope of switching to new technologies, capital intensity, and energy efficiency (decrease in the average heat rate). To provide an integral economic assessment of the above strategies, the authors modified the traditional approach based on determination of the overall discounted costs of power supply (least-cost planning) supplemented with a comparison by the weighted average wholesale price of the electricity. A method for prediction of the wholesale price is proposed reasoning from the direct and dual solutions of the optimization problem. The method can be adapted to various combinations of the mechanisms of payment for the electricity and the capacity on the basis of marginal and average costs. Energy and economic analysis showed that the opposite effects of reduction in the capital investment and fuel saving change in a nonlinear way as the scope of the switch to more advanced power generation technologies at the TPPs increases. As a consequence, a strategy for modernization of the existing power plants rational with respect to total costs of the power supply and wholesale electricity prices has been formulated. The strategy combines decisions on upgrade and replacement of the equipment at the existing power plants of various types. The basic parameters of the strategy for the future until 2035 are provided.
A strategy for high specific power pyroelectric energy harvesting from a fluid source
NASA Astrophysics Data System (ADS)
Maheux, E.; Hrebtov, M. Yu.; Sukhorukov, G.; Kozyulin, N. N.; Bobrov, M. S.; Dobroselsky, K. G.; Chikishev, L. M.; Dulin, V. M.; Yudin, P. V.
2017-12-01
Conversion of waste heat into usable electricity is now one of the important strategies for saving natural resources and minimizing impact on the environment. In contrast to Seebeck devices, utilizing a temperature gradient, pyroelectric scavengers use temporal temperature oscillations. Here, optimal strategies for pyroelectric energy harvesting are theoretically investigated from the point of view of non-stationary heat exchange for the application-relevant case of harvesting with a pyroelectric lamella from a fluid heat source. It is shown that for a fixed lamella thickness by choosing appropriate phase shift between the temperature oscillations and the voltage on the pyroelectric lamella, one can effectively operate at high frequencies and achieve a two to three-fold increase in specific power with respect to the classical Olsen cycle. A further increase in specific power is achieved by thinning down the lamella. For devices with a thickness down to a few hundreds of nanometers, specific power linearly increases with the inverse thickness. Further scaling down of the device is hampered with the heat exchange in the boundary layer. Our simulations for a representative pyroelectric Pb(Zr0,5Ti0,5)O3 predict harvestable powers of the order of kW/kg for a device with a thickness in the range from 100 nm to 1 μm, operating at hundreds of Hz.
Performance of MIMO-OFDM using convolution codes with QAM modulation
NASA Astrophysics Data System (ADS)
Astawa, I. Gede Puja; Moegiharto, Yoedy; Zainudin, Ahmad; Salim, Imam Dui Agus; Anggraeni, Nur Annisa
2014-04-01
Performance of Orthogonal Frequency Division Multiplexing (OFDM) system can be improved by adding channel coding (error correction code) to detect and correct errors that occur during data transmission. One can use the convolution code. This paper present performance of OFDM using Space Time Block Codes (STBC) diversity technique use QAM modulation with code rate ½. The evaluation is done by analyzing the value of Bit Error Rate (BER) vs Energy per Bit to Noise Power Spectral Density Ratio (Eb/No). This scheme is conducted 256 subcarrier which transmits Rayleigh multipath fading channel in OFDM system. To achieve a BER of 10-3 is required 10dB SNR in SISO-OFDM scheme. For 2×2 MIMO-OFDM scheme requires 10 dB to achieve a BER of 10-3. For 4×4 MIMO-OFDM scheme requires 5 dB while adding convolution in a 4x4 MIMO-OFDM can improve performance up to 0 dB to achieve the same BER. This proves the existence of saving power by 3 dB of 4×4 MIMO-OFDM system without coding, power saving 7 dB of 2×2 MIMO-OFDM and significant power savings from SISO-OFDM system.
A Computationally Efficient Visual Saliency Algorithm Suitable for an Analog CMOS Implementation.
D'Angelo, Robert; Wood, Richard; Lowry, Nathan; Freifeld, Geremy; Huang, Haiyao; Salthouse, Christopher D; Hollosi, Brent; Muresan, Matthew; Uy, Wes; Tran, Nhut; Chery, Armand; Poppe, Dorothy C; Sonkusale, Sameer
2018-06-27
Computer vision algorithms are often limited in their application by the large amount of data that must be processed. Mammalian vision systems mitigate this high bandwidth requirement by prioritizing certain regions of the visual field with neural circuits that select the most salient regions. This work introduces a novel and computationally efficient visual saliency algorithm for performing this neuromorphic attention-based data reduction. The proposed algorithm has the added advantage that it is compatible with an analog CMOS design while still achieving comparable performance to existing state-of-the-art saliency algorithms. This compatibility allows for direct integration with the analog-to-digital conversion circuitry present in CMOS image sensors. This integration leads to power savings in the converter by quantizing only the salient pixels. Further system-level power savings are gained by reducing the amount of data that must be transmitted and processed in the digital domain. The analog CMOS compatible formulation relies on a pulse width (i.e., time mode) encoding of the pixel data that is compatible with pulse-mode imagers and slope based converters often used in imager designs. This letter begins by discussing this time-mode encoding for implementing neuromorphic architectures. Next, the proposed algorithm is derived. Hardware-oriented optimizations and modifications to this algorithm are proposed and discussed. Next, a metric for quantifying saliency accuracy is proposed, and simulation results of this metric are presented. Finally, an analog synthesis approach for a time-mode architecture is outlined, and postsynthesis transistor-level simulations that demonstrate functionality of an implementation in a modern CMOS process are discussed.
Planning Under Uncertainty: Methods and Applications
2010-06-09
begun research into fundamental algorithms for optimization and re?optimization of continuous optimization problems (such as linear and quadratic... algorithm yields a 14.3% improvement over the original design while saving 68.2 % of the simulation evaluations compared to standard sample-path...They provide tools for building and justifying computational algorithms for such problems. Year. 2010 Month: 03 Final Research under this grant
Design of resolution/power controllable Asynchronous Sigma-Delta Modulator
NASA Astrophysics Data System (ADS)
Deshmukh, Anita Arvind; Deshmukh, Raghvendra B.
2016-12-01
This paper presents the design of a Programmable Asynchronous Modulator (PAM) with field control of resolution and power. A novel variable hysteresis Schmitt Trigger (ST) is used for external programmability. Asynchronous Sigma-Delta Modulator (ASDM) implementation with external control voltages is proposed to supervise the resolution and power. This architecture with reduced circuit complexity considerably improves the earlier realizations by eliminating multiple current sources as well switched capacitor circuits and results in power saving up to 87 %. Proposed PAM design demonstrates an improved SNDR of 115 dB, DR of 96 dB, and power consumption below 280 μW. It illustrates Effective Number of Bits (ENOB) to 18.81 and Figure of Merit (FoM) to 0.15 fJ/conversion step. Modulator is implemented in Cadence UMC Hspice 0.18 μm CMOS analog technology. Off-chip PAM control for resolution/power performance has potential applications in battery operated ultra low power applications like IoT; where ADC is one of the major power consuming components. It offers the promise for an efficient performance with power saving.
Analysis of Application Power and Schedule Composition in a High Performance Computing Environment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elmore, Ryan; Gruchalla, Kenny; Phillips, Caleb
As the capacity of high performance computing (HPC) systems continues to grow, small changes in energy management have the potential to produce significant energy savings. In this paper, we employ an extensive informatics system for aggregating and analyzing real-time performance and power use data to evaluate energy footprints of jobs running in an HPC data center. We look at the effects of algorithmic choices for a given job on the resulting energy footprints, and analyze application-specific power consumption, and summarize average power use in the aggregate. All of these views reveal meaningful power variance between classes of applications as wellmore » as chosen methods for a given job. Using these data, we discuss energy-aware cost-saving strategies based on reordering the HPC job schedule. Using historical job and power data, we present a hypothetical job schedule reordering that: (1) reduces the facility's peak power draw and (2) manages power in conjunction with a large-scale photovoltaic array. Lastly, we leverage this data to understand the practical limits on predicting key power use metrics at the time of submission.« less
12 CFR 560.43 - Foreign assistance investments.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Foreign assistance investments. 560.43 Section... INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.43 Foreign assistance investments. Pursuant to HOLA section 5(c)(4)(C), a Federal savings association may make foreign assistance...
12 CFR 560.43 - Foreign assistance investments.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Foreign assistance investments. 560.43 Section... INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.43 Foreign assistance investments. Pursuant to HOLA section 5(c)(4)(C), a Federal savings association may make foreign assistance...
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
This two-page performance spotlight describes how, in 2004, Austin Energy (the electric utility for the city of Austin, Texas) began saving about $1.2 million in energy and maintenance costs annually as a direct result of a pumping system efficiency proj
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
This two-page performance spotlight describes how, in 2004, Austin Energy (the electric utility for the city of Austin, Texas) began saving about $1.2 million in energy and maintenance costs annually as a direct result of a pumping system efficiency project.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Late charges. 560.33 Section 560.33 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.33 Late charges. A Federal savings association may...
Thermal Energy Briefing with FPL
2017-02-17
Bart Gaetjens, Florida Power & Light's FPL area external affairs manager, addresses the news media and NASA Social about the new Thermal Energy Storage (TES) tank Feb. 17. The TES tank works like a giant battery and is saving the center utility cost. These savings will be applied to new sustainable projects at Kennedy.
Thermoelectric System Absorbing Waste Heat from a Steel Ladle
NASA Astrophysics Data System (ADS)
Lu, Baiyi; Meng, Xiangning; Zhu, Miaoyong; Suzuki, Ryosuke O.
2018-06-01
China's iron and steel industry has made great progress in energy savings and emission reductions with the application of many waste heat recovery technologies. However, most of the medium and low temperature waste heat and radiant waste heat has not been effectively utilized. This paper proposes a thermoelectric system that generates electricity by absorbing the radiant heat from the surface of steel ladles in a steel plant. The thermoelectric behavior of modules in this system is analyzed by a numerical simulation method. The effects of external resistance and module structure on thermoelectric performance are also discussed in the temperature range of the wall surface of a steel ladle. The results show that the wall temperature has a significant influence on the thermoelectric behavior of the module, so its uniformity and stability should be considered in practical application. The ratio of the optimum external resistance to the internal resistance of the thermoelectric module is in the range of 1.6-2.0, which indicates the importance of external load optimization for a given thermoelectric system. In addition, the output power and the conversion efficiency of the module can be significantly improved by increasing the length of the thermoelectric legs and adopting a double-layer structure. Finally, through the optimization of external resistance and structure, the power output can reach 83-304 W/m2. This system is shown to be a promising approach for energy recovery.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Dingfeng; Yao, Wei; Yan, Yanci
The development of new routes for the production of thermoelectric materials with low-cost and high-performance characteristics has been one of the long-term strategies for saving and harvesting thermal energy. We report a new approach for improving thermoelectric properties by employing the intrinsically low thermal conductivity of a quasi-one-dimensional (quasi-1D) crystal structure and optimizing the power factor with aliovalent ion doping. As an example, we demonstrated that SbCrSe 3, in which two parallel chains of CrSe 6 octahedra are linked by antimony atoms, possesses a quasi-1D property that resulted in an ultra-low thermal conductivity of 0.56 W m -1 K -1more » at 900 K. After maximizing the power factor by Pb doping, the peak ZT value of the optimized Pb-doped sample reached 0.46 at 900 K, which is an enhancement of 24 times that of the parent SbCrSe 3 structure. The mechanisms that lead to low thermal conductivity derive from anharmonic phonons with the presence of the lone-pair electrons of Sb atoms and weak bonds between the CrSe 6 double chains. Our results shed new light on the design of new and high-performance thermoelectric materials.« less
Strategies for Energy Efficient Resource Management of Hybrid Programming Models
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Dong; Supinski, Bronis de; Schulz, Martin
2013-01-01
Many scientific applications are programmed using hybrid programming models that use both message-passing and shared-memory, due to the increasing prevalence of large-scale systems with multicore, multisocket nodes. Previous work has shown that energy efficiency can be improved using software-controlled execution schemes that consider both the programming model and the power-aware execution capabilities of the system. However, such approaches have focused on identifying optimal resource utilization for one programming model, either shared-memory or message-passing, in isolation. The potential solution space, thus the challenge, increases substantially when optimizing hybrid models since the possible resource configurations increase exponentially. Nonetheless, with the accelerating adoptionmore » of hybrid programming models, we increasingly need improved energy efficiency in hybrid parallel applications on large-scale systems. In this work, we present new software-controlled execution schemes that consider the effects of dynamic concurrency throttling (DCT) and dynamic voltage and frequency scaling (DVFS) in the context of hybrid programming models. Specifically, we present predictive models and novel algorithms based on statistical analysis that anticipate application power and time requirements under different concurrency and frequency configurations. We apply our models and methods to the NPB MZ benchmarks and selected applications from the ASC Sequoia codes. Overall, we achieve substantial energy savings (8.74% on average and up to 13.8%) with some performance gain (up to 7.5%) or negligible performance loss.« less
NASA Astrophysics Data System (ADS)
Ding, Ruqi; Xu, Bing; Zhang, Junhui; Cheng, Min
2017-08-01
Independent metering control systems are promising fluid power technologies compared with traditional valve controlled systems. By breaking the mechanical coupling between the inlet and outlet, the meter-out valve can open as large as possible to reduce energy consumptions. However, the lack of damping in outlet causes stronger vibrations. To address the problem, the paper designs a hybrid control method combining dynamic pressure-feedback and active damping control. The innovation resides in the optimization of damping by introducing pressure feedback to make trade-offs between high stability and fast response. To achieve this goal, the dynamic response pertaining to the control parameters consisting of feedback gain and cut-off frequency, are analyzed via pole-zero locations. Accordingly, these parameters are tuned online in terms of guaranteed dominant pole placement such that the optimal damping can be accurately captured under a considerable variation of operating conditions. The experiment is deployed in a mini-excavator. The results pertaining to different control parameters confirm the theoretical expectations via pole-zero locations. By using proposed self-tuning controller, the vibrations are almost eliminated after only one overshoot for different operation conditions. The overshoots are also reduced with less decrease of the response time. In addition, the energy-saving capability of independent metering system is still not affected by the improvement of controllability.
Yang, Dingfeng; Yao, Wei; Yan, Yanci; ...
2017-06-09
The development of new routes for the production of thermoelectric materials with low-cost and high-performance characteristics has been one of the long-term strategies for saving and harvesting thermal energy. We report a new approach for improving thermoelectric properties by employing the intrinsically low thermal conductivity of a quasi-one-dimensional (quasi-1D) crystal structure and optimizing the power factor with aliovalent ion doping. As an example, we demonstrated that SbCrSe 3, in which two parallel chains of CrSe 6 octahedra are linked by antimony atoms, possesses a quasi-1D property that resulted in an ultra-low thermal conductivity of 0.56 W m -1 K -1more » at 900 K. After maximizing the power factor by Pb doping, the peak ZT value of the optimized Pb-doped sample reached 0.46 at 900 K, which is an enhancement of 24 times that of the parent SbCrSe 3 structure. The mechanisms that lead to low thermal conductivity derive from anharmonic phonons with the presence of the lone-pair electrons of Sb atoms and weak bonds between the CrSe 6 double chains. Our results shed new light on the design of new and high-performance thermoelectric materials.« less
Thermoelectric System Absorbing Waste Heat from a Steel Ladle
NASA Astrophysics Data System (ADS)
Lu, Baiyi; Meng, Xiangning; Zhu, Miaoyong; Suzuki, Ryosuke O.
2018-01-01
China's iron and steel industry has made great progress in energy savings and emission reductions with the application of many waste heat recovery technologies. However, most of the medium and low temperature waste heat and radiant waste heat has not been effectively utilized. This paper proposes a thermoelectric system that generates electricity by absorbing the radiant heat from the surface of steel ladles in a steel plant. The thermoelectric behavior of modules in this system is analyzed by a numerical simulation method. The effects of external resistance and module structure on thermoelectric performance are also discussed in the temperature range of the wall surface of a steel ladle. The results show that the wall temperature has a significant influence on the thermoelectric behavior of the module, so its uniformity and stability should be considered in practical application. The ratio of the optimum external resistance to the internal resistance of the thermoelectric module is in the range of 1.6-2.0, which indicates the importance of external load optimization for a given thermoelectric system. In addition, the output power and the conversion efficiency of the module can be significantly improved by increasing the length of the thermoelectric legs and adopting a double-layer structure. Finally, through the optimization of external resistance and structure, the power output can reach 83-304 W/m2. This system is shown to be a promising approach for energy recovery.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurnik, Charles W.; Simons, George; Barsun, Stephan
The main focus of most evaluations is to determine the energy-savings impacts of the installed measure. This protocol defines a combined heat and power (CHP) measure as a system that sequentially generates both electrical energy and useful thermal energy from one fuel source at a host customer's facility or residence. This protocol is aimed primarily at regulators and administrators of ratepayer-funded CHP programs; however, project developers may find the protocol useful to understand how CHP projects are evaluated.
Quantitative description of realistic wealth distributions by kinetic trading models
NASA Astrophysics Data System (ADS)
Lammoglia, Nelson; Muñoz, Víctor; Rogan, José; Toledo, Benjamín; Zarama, Roberto; Valdivia, Juan Alejandro
2008-10-01
Data on wealth distributions in trading markets show a power law behavior x-(1+α) at the high end, where, in general, α is greater than 1 (Pareto’s law). Models based on kinetic theory, where a set of interacting agents trade money, yield power law tails if agents are assigned a saving propensity. In this paper we are solving the inverse problem, that is, in finding the saving propensity distribution which yields a given wealth distribution for all wealth ranges. This is done explicitly for two recently published and comprehensive wealth datasets.
An overview of flywheel technology for space applications
NASA Astrophysics Data System (ADS)
Decker, D. Kent; Spector, Victor A.; Pieronek, Thomas J.
1997-01-01
Recent developments in advanced composite flywheels using magnetic bearings has produced specific energies greater than 30 Whr/lb. These specific energy levels provide an opportunity for significant spacecraft weight savings compared to using nickel-hydrogen battery technology. Additional weight savings are possible if the flywheels are also used for momentum control. This paper explores the new challenges presented by application of flywheel technology to space power and attitude control subsystems. Issues with respect to mission application, safety and containment, launch environment, and combined power and attitude control operation are discussed.
Should the next standby power target be 0-watt?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meier, Alan; Siderius, Hans-Paul
The standby power use of appliances continues to consume large amounts of electricity. Considerable success has been made in reducing each device’s use, but these savings have been offset by a huge increase in the number of products using standby power and new power requirements for maintaining network connections. Current strategies to reduce standby have limitations and may not be most appropriate for emerging energy consumption trends. A new strategy for further reductions in standby, the “Standzero” option, encourages electrical products to be designed to operate for short periods without relying on mains-supplied electricity. Energy savings are achieved through enhancedmore » efficiency and by harvesting ambient energy. A sensitivity analysis suggests many appliances could be designed to operate for at least an hour without relying on mains power and, in some cases, may be able to operate indefinitely at zero watts until activated.« less
VO2 thermochromic smart window for energy savings and generation
Zhou, Jiadong; Gao, Yanfeng; Zhang, Zongtao; Luo, Hongjie; Cao, Chuanxiang; Chen, Zhang; Dai, Lei; Liu, Xinling
2013-01-01
The ability to achieve energy saving in architectures and optimal solar energy utilisation affects the sustainable development of the human race. Traditional smart windows and solar cells cannot be combined into one device for energy saving and electricity generation. A VO2 film can respond to the environmental temperature to intelligently regulate infrared transmittance while maintaining visible transparency, and can be applied as a thermochromic smart window. Herein, we report for the first time a novel VO2-based smart window that partially utilises light scattering to solar cells around the glass panel for electricity generation. This smart window combines energy-saving and generation in one device, and offers potential to intelligently regulate and utilise solar radiation in an efficient manner. PMID:24157625
VO₂ thermochromic smart window for energy savings and generation.
Zhou, Jiadong; Gao, Yanfeng; Zhang, Zongtao; Luo, Hongjie; Cao, Chuanxiang; Chen, Zhang; Dai, Lei; Liu, Xinling
2013-10-24
The ability to achieve energy saving in architectures and optimal solar energy utilisation affects the sustainable development of the human race. Traditional smart windows and solar cells cannot be combined into one device for energy saving and electricity generation. A VO2 film can respond to the environmental temperature to intelligently regulate infrared transmittance while maintaining visible transparency, and can be applied as a thermochromic smart window. Herein, we report for the first time a novel VO2-based smart window that partially utilises light scattering to solar cells around the glass panel for electricity generation. This smart window combines energy-saving and generation in one device, and offers potential to intelligently regulate and utilise solar radiation in an efficient manner.
The Role of Distributed Generation and Combined Heat and Power (CHP) Systems in Data Centers
This report reviews how distributed generation (DG) resources such as fuel cells, reciprocating engines, and gas turbines can offer powerful energy efficiency savings in data centers, particularly when configured in combined heat and power (CHP) mode.
Evangelista, Daniela; Zuccaro, Antonio; Lančinskas, Algirdas; Žilinskas, Julius; Guarracino, Mario R
2016-02-17
The cost per patient of next generation sequencing for detection of rare mutations may be significantly reduced using pooled experiments. Recently, some techniques have been proposed for the planning of pooled experiments and for the optimal allocation of patients into pools. However, the lack of a user friendly resource for planning the design of pooled experiments forces the scientists to do frequent, complex and long computations. OPENDoRM is a powerful collection of novel mathematical algorithms usable via an intuitive graphical user interface. It enables researchers to speed up the planning of their routine experiments, as well as, to support scientists without specific bioinformatics expertises. Users can automatically carry out analysis in terms of costs associated with the optimal allocation of patients in pools. They are also able to choose between three distinct pooling mathematical methods, each of which also suggests the optimal configuration for the submitted experiment. Importantly, in order to keep track of the performed experiments, users can save and export the results of their experiments in standard tabular and charts contents. OPENDoRM is a freely available web-oriented application for the planning of pooled NGS experiments, available at: http://www-labgtp.na.icar.cnr.it/OPENDoRM. Its easy and intuitive graphical user interface enables researchers to plan theirs experiments using novel algorithms, and to interactively visualize the results.
Zhen, Xiaofei; Osman, Yassir Idris Abdalla; Feng, Rong; Si, Zetian
2018-01-01
Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV) conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment. PMID:29862289
Kang, Jian; Li, Jinping; Zhen, Xiaofei; Osman, Yassir Idris Abdalla; Feng, Rong; Si, Zetian
2018-01-01
Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV) conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m 3 . Even though the ambient temperature reached -25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO 2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment.
New generation of compact high power disk lasers
NASA Astrophysics Data System (ADS)
Feuchtenbeiner, Stefanie; Zaske, Sebastian; Schad, Sven-Silvius; Gottwald, Tina; Kuhn, Vincent; Kumkar, Sören; Metzger, Bernd; Killi, Alexander; Haug, Patrick; Speker, Nicolai
2018-02-01
New technological developments in high power disk lasers emitting at 1030 nm are presented. These include the latest generation of TRUMPF's TruDisk product line offering high power disk lasers with up to 6 kW output power and beam qualities of up to 4 mm*mrad. With these compact devices a footprint reduction of 50% compared to the previous model could be achieved while at the same time improving robustness and increasing system efficiency. In the context of Industry 4.0, the new generation of TruDisk lasers features a synchronized data recording of all sensors, offering high-quality data for virtual analyses. The lasers therefore provide optimal hardware requirements for services like Condition Monitoring and Predictive Maintenance. We will also discuss its innovative and space-saving cooling architecture. It allows operation of the laser under very critical ambient conditions. Furthermore, an outlook on extending the new disk laser platform to higher power levels will be given. We will present a disk laser with 8 kW laser power out of a single disk with a beam quality of 5 mm*mrad using a 125 μm fiber, which makes it ideally suited for cutting and welding applications. The flexibility of the disk laser platform also enables the realization of a wide variety of beam guiding setups. As an example a new scheme called BrightLine Weld will be discussed. This technology allows for an almost spatter free laser welding process, even at high feed rates.
Design of electric vehicle charging station based on wind and solar complementary power supply
NASA Astrophysics Data System (ADS)
Wang, Li
2018-05-01
Electric vehicles have become a major trend in the development of the automobile industry. Green energy saving is an important feature of their development. At the same time, the related charging facilities construction is also critical. If we improve the charging measures to adapt to its green energy-saving features, it will be to a greater extent to promote its further development. This article will propose a highly efficient green energy-saving charging station designed for the electric vehicles.
12 CFR 550.150 - Who is responsible for the exercise of fiduciary powers?
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Who is responsible for the exercise of fiduciary powers? 550.150 Section 550.150 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Fiduciary Personnel and...
12 CFR 550.560 - When may the OTS revoke my fiduciary powers?
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false When may the OTS revoke my fiduciary powers? 550.560 Section 550.560 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Terminating Fiduciary Activities Revocation of Fiduciary Powers...
12 CFR 550.540 - When will the OTS terminate my fiduciary powers?
Code of Federal Regulations, 2010 CFR
2010-01-01
... 12 Banks and Banking 5 2010-01-01 2010-01-01 false When will the OTS terminate my fiduciary powers? 550.540 Section 550.540 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Terminating Fiduciary Activities Surrender of Fiduciary Powers...
12 CFR 550.540 - When will the OTS terminate my fiduciary powers?
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false When will the OTS terminate my fiduciary powers? 550.540 Section 550.540 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Terminating Fiduciary Activities Surrender of Fiduciary Powers...
12 CFR 550.560 - When may the OTS revoke my fiduciary powers?
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false When may the OTS revoke my fiduciary powers? 550.560 Section 550.560 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Terminating Fiduciary Activities Revocation of Fiduciary Powers...
Solar-Powered Water Distillation
NASA Technical Reports Server (NTRS)
Menninger, F. J.; Elder, R. J.
1985-01-01
Solar-powered still produces pure water at rate of 6,000 gallons per year. Still fully automatic and gravity-fed. Only outside electric power is timer clock and solenoid-operated valve. Still saves $5,000 yearly in energy costs and pays for itself in 3 1/2 years.
Zhao, Jia; Hu, Liang; Ding, Yan; Xu, Gaochao; Hu, Ming
2014-01-01
The field of live VM (virtual machine) migration has been a hotspot problem in green cloud computing. Live VM migration problem is divided into two research aspects: live VM migration mechanism and live VM migration policy. In the meanwhile, with the development of energy-aware computing, we have focused on the VM placement selection of live migration, namely live VM migration policy for energy saving. In this paper, a novel heuristic approach PS-ES is presented. Its main idea includes two parts. One is that it combines the PSO (particle swarm optimization) idea with the SA (simulated annealing) idea to achieve an improved PSO-based approach with the better global search's ability. The other one is that it uses the Probability Theory and Mathematical Statistics and once again utilizes the SA idea to deal with the data obtained from the improved PSO-based process to get the final solution. And thus the whole approach achieves a long-term optimization for energy saving as it has considered not only the optimization of the current problem scenario but also that of the future problem. The experimental results demonstrate that PS-ES evidently reduces the total incremental energy consumption and better protects the performance of VM running and migrating compared with randomly migrating and optimally migrating. As a result, the proposed PS-ES approach has capabilities to make the result of live VM migration events more high-effective and valuable. PMID:25251339
Zhao, Jia; Hu, Liang; Ding, Yan; Xu, Gaochao; Hu, Ming
2014-01-01
The field of live VM (virtual machine) migration has been a hotspot problem in green cloud computing. Live VM migration problem is divided into two research aspects: live VM migration mechanism and live VM migration policy. In the meanwhile, with the development of energy-aware computing, we have focused on the VM placement selection of live migration, namely live VM migration policy for energy saving. In this paper, a novel heuristic approach PS-ES is presented. Its main idea includes two parts. One is that it combines the PSO (particle swarm optimization) idea with the SA (simulated annealing) idea to achieve an improved PSO-based approach with the better global search's ability. The other one is that it uses the Probability Theory and Mathematical Statistics and once again utilizes the SA idea to deal with the data obtained from the improved PSO-based process to get the final solution. And thus the whole approach achieves a long-term optimization for energy saving as it has considered not only the optimization of the current problem scenario but also that of the future problem. The experimental results demonstrate that PS-ES evidently reduces the total incremental energy consumption and better protects the performance of VM running and migrating compared with randomly migrating and optimally migrating. As a result, the proposed PS-ES approach has capabilities to make the result of live VM migration events more high-effective and valuable.
12 CFR 560.37 - Real estate for office and related facilities.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Real estate for office and related facilities... LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.37 Real estate for office and related facilities. A federal savings association may invest in real estate (improved...
12 CFR 560.37 - Real estate for office and related facilities.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Real estate for office and related facilities... LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.37 Real estate for office and related facilities. A federal savings association may invest in real estate (improved...
12 CFR 560.37 - Real estate for office and related facilities.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Real estate for office and related facilities... LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.37 Real estate for office and related facilities. A federal savings association may invest in real estate (improved...
12 CFR 560.37 - Real estate for office and related facilities.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Real estate for office and related facilities... LENDING AND INVESTMENT Lending and Investment Powers for Federal Savings Associations § 560.37 Real estate for office and related facilities. A federal savings association may invest in real estate (improved...
Settlement of reactive power compensation in the light of white certificates
NASA Astrophysics Data System (ADS)
Zajkowski, Konrad
2017-10-01
The article discusses the problem of the determination of savings on active energy as a result of a reactive power compensation. Statutory guidance on the required energy audit to obtain white certificates in the European Union was followed. The analysis was made on the basis of the Polish Law. The paper presents a detailed analytical method and an estimation method taking into account the impact on the line, the transformer and the generator. According to the relevant guidelines in the European Union, the reduction of CO2 emissions by calculating the saving of active power should be determined. The detailed method and an estimation method proposed for the determination of savings on active energy as a result of the reactive power compensation carried out possess some errors and inconvenience. The detailed method requires knowledge of the network topology and a determination of reactive power Q at each point of the network. The estimation method of analysis is easy in execution, especially if the consumer of energy is the main or the most significant purchaser of electricity in the network. Unfortunately, this latter method can be used only for activities that do not require high computational accuracy. The results obtained by this method are approximate values that can be used for the calculation of economic indicators. The estimation method is suitable for determining the number of white certificates when a power audit concerns a recipient of electricity, the structure of which is a large number of divisions scattered at many different locations in the power system.
Wide Bandgap Semiconductor Opportunities in Power Electronics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Das, Sujit; Marlino, Laura D.; Armstrong, Kristina O.
The report objective is to explore the Wide Bandgap (WBG) Power Electronics (PE) market, applications, and potential energy savings in order to identify key areas where further resources and investments of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE EERE) would have the most impact on U.S. competiveness. After considering the current market, several potential near-term application areas were identified as having significant market and energy savings potential with respect to clean energy applications: (1) data centers (uninterruptible power supplies and server power supplies); (2) renewable energy generation (photovoltaic-solar and wind); (3) motor drives (industrial,more » commercial and residential); (4) rail traction; and, (5) hybrid and electric vehicles (traction and charging). After the initial explorative analyses, it became clear that, SiC, not GaN, would be the principal WBG power device material for the chosen markets in the near future. Therefore, while GaN is discussed when appropriate, this report focuses on SiC devices, other WBG applications (e.g., solid-state transformers, combined heat and power, medical, and wireless power), the GaN market, and GaN specific applications (e.g., LiDAR, 5G) will be explored at a later date. In addition to the market, supply and value chain analyses addressed in Section 1 of this report, a SWOT (Strength, Weakness, Opportunity, Threat) analysis and potential energy savings analysis was conducted for each application area to identify the major potential WBG application area(s) with a U.S. competitiveness opportunity in the future.« less
Design and Analysis of Optimal Ascent Trajectories for Stratospheric Airships
NASA Astrophysics Data System (ADS)
Mueller, Joseph Bernard
Stratospheric airships are lighter-than-air vehicles that have the potential to provide a long-duration airborne presence at altitudes of 18-22 km. Designed to operate on solar power in the calm portion of the lower stratosphere and above all regulated air traffic and cloud cover, these vehicles represent an emerging platform that resides between conventional aircraft and satellites. A particular challenge for airship operation is the planning of ascent trajectories, as the slow moving vehicle must traverse the high wind region of the jet stream. Due to large changes in wind speed and direction across altitude and the susceptibility of airship motion to wind, the trajectory must be carefully planned, preferably optimized, in order to ensure that the desired station be reached within acceptable performance bounds of flight time and energy consumption. This thesis develops optimal ascent trajectories for stratospheric airships, examines the structure and sensitivity of these solutions, and presents a strategy for onboard guidance. Optimal ascent trajectories are developed that utilize wind energy to achieve minimum-time and minimum-energy flights. The airship is represented by a three-dimensional point mass model, and the equations of motion include aerodynamic lift and drag, vectored thrust, added mass effects, and accelerations due to mass flow rate, wind rates, and Earth rotation. A representative wind profile is developed based on historical meteorological data and measurements. Trajectory optimization is performed by first defining an optimal control problem with both terminal and path constraints, then using direct transcription to develop an approximate nonlinear parameter optimization problem of finite dimension. Optimal ascent trajectories are determined using SNOPT for a variety of upwind, downwind, and crosswind launch locations. Results of extensive optimization solutions illustrate definitive patterns in the ascent path for minimum time flights across varying launch locations, and show that significant energy savings can be realized with minimum-energy flights, compared to minimum-time time flights, given small increases in flight time. The performance of the optimal trajectories are then studied with respect to solar energy production during ascent, as well as sensitivity of the solutions to small changes in drag coefficient and wind model parameters. Results of solar power model simulations indicate that solar energy is sufficient to power ascent flights, but that significant energy loss can occur for certain types of trajectories. Sensitivity to the drag and wind model is approximated through numerical simulations, showing that optimal solutions change gradually with respect to changing wind and drag parameters and providing deeper insight into the characteristics of optimal airship flights. Finally, alternative methods are developed to generate near-optimal ascent trajectories in a manner suitable for onboard implementation. The structures and characteristics of previously developed minimum-time and minimum-energy ascent trajectories are used to construct simplified trajectory models, which are efficiently solved in a smaller numerical optimization problem. Comparison of these alternative solutions to the original SNOPT solutions show excellent agreement, suggesting the alternate formulations are an effective means to develop near-optimal solutions in an onboard setting.
Multiple Power-Saving MSSs Scheduling Methods for IEEE802.16e Broadband Wireless Networks
2014-01-01
This work proposes two enhanced multiple mobile subscriber stations (MSSs) power-saving scheduling methods for IEEE802.16e broadband wireless networks. The proposed methods are designed for the Unsolicited Grant Service (UGS) of IEEE802.16e. To reduce the active periods of all power-saving MSSs, the base station (BS) allocates each MSS fewest possible transmission frames to retrieve its data from the BS. The BS interlaces the active periods of each MSS to increase the amount of scheduled MSSs and splits the overflowing transmission frames to maximize the bandwidth utilization. Simulation results reveal that interlacing the active periods of MSSs can increase the number of scheduled MSSs to more than four times of that in the Direct scheduling method. The bandwidth utilization can thus be improved by 60%–70%. Splitting the overflowing transmission frames can improve bandwidth utilization by more than 10% over that achieved using the method of interlacing active periods, with a sacrifice of only 1% of the sleep periods in the interlacing active period method. PMID:24523656
Mobile recommender application for promoting electricity saving among Iraqis
NASA Astrophysics Data System (ADS)
Sabri, Manhal Isam; Hussain, Azham
2017-10-01
Mobile utilization has rapidly expanded due to its feasibility in executing different applications that can be used in solving everyday problems. Common issues in daily life include electricity saving. In Iraq, the Ministry of Power seriously faces such issue. This is because most households have lack access to information regarding to sufficient power consumption, as well as applications that educate about such saving. Therefore, this study aims at developing a mobile application for Iraqi to help them understand the basis for reducing electricity consumption based on the meter data supplied by the users for square meter along with the active devices and period of usage. The proposed mobile application was evaluated by 50 households from the perspective of ease of use, usefulness, ease of learning, and satisfaction. The obtained result showed that majority of the participants found the application to be ease to use, useful, easy to learn, and were satisfied with its functionalities. The study findings provide some insights about the importance of using mobile application for promoting households in Iraq to manage their power consumption behavior.
NASA Technical Reports Server (NTRS)
D'souza, Sarah N.; Kinney, David J.; Garcia, Joseph A.; Sarigul-Klijn, Nesrin
2014-01-01
The state-of-the-art in vehicle design decouples flight feasible trajectory generation from the optimization process of an entry spacecraft shape. The disadvantage to this decoupled process is seen when a particular aeroshell does not meet in-flight requirements when integrated into Guidance, Navigation, and Control simulations. It is postulated that the integration of a guidance algorithm into the design process will provide a real-time, rapid trajectory generation technique to enhance the robustness of vehicle design solutions. The potential benefit of this integration is a reduction in design cycles (possible cost savings) and increased accuracy in the aerothermal environment (possible mass savings). This work examines two aspects: 1) the performance of a reference tracking guidance algorithm for five different geometries with the same reference trajectory and 2) the potential of mass savings from improved aerothermal predictions. An Apollo Derived Guidance (ADG) algorithm is used in this study. The baseline geometry and five test case geometries were flown using the same baseline trajectory. The guided trajectory results are compared to separate trajectories determined in a vehicle optimization study conducted for NASA's Mars Entry, Descent, and Landing System Analysis. This study revealed several aspects regarding the potential gains and required developments for integrating a guidance algorithm into the vehicle optimization environment. First, the generation of flight feasible trajectories is only as good as the robustness of the guidance algorithm. The set of dispersed geometries modelled aerodynamic dispersions that ranged from +/-1% to +/-17% and a single extreme case was modelled where the aerodynamics were approximately 80% less than the baseline geometry. The ADG, as expected, was able to guide the vehicle into the aeroshell separation box at the target location for dispersions up to 17%, but failed for the 80% dispersion cases. Finally, the results revealed that including flight feasible trajectories for a set of dispersed geometries has the potential to save mass up to 430 kg.
Cost Savings Associated with the LV 100-5 Tank Engine
2002-03-01
34 F. UNDER ARMOR AUXILLARY POWER UNIT...................................... 35 viii G. SUMMARY...48 E. UNDER ARMOR AUXILLARY POWER UNIT...................................... 49 F. SUMMARY...the gunner and commander thermal sights. An under armor auxiliary power unit, new computer mass memory unit, color maps and displays are included
Automated System Tests High-Power MOSFET's
NASA Technical Reports Server (NTRS)
Huston, Steven W.; Wendt, Isabel O.
1994-01-01
Computer-controlled system tests metal-oxide/semiconductor field-effect transistors (MOSFET's) at high voltages and currents. Measures seven parameters characterizing performance of MOSFET, with view toward obtaining early indication MOSFET defective. Use of test system prior to installation of power MOSFET in high-power circuit saves time and money.
Wireless network interface energy consumption implications of popular streaming formats
NASA Astrophysics Data System (ADS)
Chandra, Surendar
2001-12-01
With the proliferation of mobile streaming multimedia, available battery capacity constrains the end-user experience. Since streaming applications tend to be long running, wireless network interface card's (WNIC) energy consumption is particularly an acute problem. In this work, we explore the WNIC energy consumption implications of popular multimedia streaming formats from Microsoft (Windows media), Real (Real media) and Apple (Quick Time). We investigate the energy consumption under varying stream bandwidth and network loss rates. We also explore history-based client-side strategies to reduce the energy consumed by transitioning the WNICs to a lower power consuming sleep state. We show that Microsoft media tends to transmit packets at regular intervals; streams optimized for 28.8 Kbps can save over 80% in energy consumption with 2% data loss. A high bandwidth stream (768 Kbps) can still save 57% in energy consumption with less than 0.3% data loss. For high bandwidth streams, Microsoft media exploits network-level packet fragmentation, which can lead to excessive packet loss (and wasted energy) in a lossy network. Real stream packets tend to be sent closer to each other, especially at higher bandwidths. Quicktime packets sometimes arrive in quick succession; most likely an application level fragmentation mechanism. Such packets are harder to predict at the network level without understanding the packet semantics.
Increasing the energy conservation awareness using the influential power of a lottery system
NASA Astrophysics Data System (ADS)
Nayak, Amruta Vijay
This thesis presents an influence maximization-driven approach to promoting energy conservation awareness, with the objective to generate a competitive environment for energy consumption supervision. As consumers are typically reluctant to invest their time and effort in the activities beyond their business, an incentive-based distribution strategy is proposed to encourage consumers to actively take part in energy conservation. The key idea of the thesis lies in leveraging the consumer instincts as a driving factor for spreading positive social influence, via a smart lottery program. In the proposed framework, saving energy automatically increases the consumers' chances of winning the lottery, thereby motivating them to save more, while the smart winner selection will maximize the word-of-mouth effect of the program. The thesis collects and organizes a large body of literature in support of the claim that the spread of awareness in a social network can play a key role in the emergence of energy conscious behavior. It also reports on the findings of a survey conducted to determine the present day consumer perspective toward energy conservation and the level of influence required to motivate them to conserve more energy. Finally, a mathematical model for smart lottery winner selection is presented, and insightful observations are made concerning the properties of optimal solutions to tractable, small problem instances.
Life cycle assessment and economic analysis of a low concentrating photovoltaic system.
De Feo, G; Forni, M; Petito, F; Renno, C
2016-10-01
Many new photovoltaic (PV) applications, such as the concentrating PV (CPV) systems, are appearing on the market. The main characteristic of CPV systems is to concentrate sunlight on a receiver by means of optical devices and to decrease the solar cells area required. A low CPV (LCPV) system allows optimizing the PV effect with high increase of generated electric power as well as decrease of active surface area. In this paper, an economic analysis and a life cycle assessment (LCA) study of a particular LCPV scheme is presented and its environmental impacts are compared with those of a PV traditional system. The LCA study was performed with the software tool SimaPro 8.0.2, using the Econinvent 3.1 database. A functional unit of 1 kWh of electricity produced was chosen. Carbon Footprint, Ecological Footprint and ReCiPe 2008 were the methods used to assess the environmental impacts of the LCPV plant compared with a corresponding traditional system. All the methods demonstrated the environmental convenience of the LCPV system. The innovative system allowed saving 16.9% of CO2 equivalent in comparison with the traditional PV plant. The environmental impacts saving was 17% in terms of Ecological Footprint, and, finally, 15.8% with the ReCiPe method.
A CMOS pixel sensor prototype for the outer layers of linear collider vertex detector
NASA Astrophysics Data System (ADS)
Zhang, L.; Morel, F.; Hu-Guo, C.; Himmi, A.; Dorokhov, A.; Hu, Y.
2015-01-01
The International Linear Collider (ILC) expresses a stringent requirement for high precision vertex detectors (VXD). CMOS pixel sensors (CPS) have been considered as an option for the VXD of the International Large Detector (ILD), one of the detector concepts proposed for the ILC. MIMOSA-31 developed at IPHC-Strasbourg is the first CPS integrated with 4-bit column-level ADC for the outer layers of the VXD, adapted to an original concept minimizing the power consumption. It is composed of a matrix of 64 rows and 48 columns. The pixel concept combines in-pixel amplification with a correlated double sampling (CDS) operation in order to reduce the temporal noise and fixed pattern noise (FPN). At the bottom of the pixel array, each column is terminated with a self-triggered analog-to-digital converter (ADC). The ADC design was optimized for power saving at a sampling frequency of 6.25 MS/s. The prototype chip is fabricated in a 0.35 μm CMOS technology. This paper presents the details of the prototype chip and its test results.
Zhu, Qin
2013-01-01
Affordances mean opportunities for action. These affordances are important for sports performance and relevant to the abilities developed by skilled athletes. In racquet sports such as badminton, different players prefer widely different string tension because it is believed to provide opportunities for effective strokes. The current study examined whether badminton players can perceive the affordance of string tension for power strokes and whether the perception of affordance itself changed as a function of skill level. The results showed that string tension constrained the striking performance of both novice and recreational players, but not of expert players. When perceptual capability was assessed, perceptual mode did not affect perception of the optimal string tension. Skilled players successfully perceived the affordance of string tension, but only experts were concerned about saving energy. Our findings demonstrated that perception of the affordance of string tension in badminton was determined by action abilities. Furthermore, experts could adjust the action to maintain a superior level of performance based on the perception of affordance.
Parametric analysis of parameters for electrical-load forecasting using artificial neural networks
NASA Astrophysics Data System (ADS)
Gerber, William J.; Gonzalez, Avelino J.; Georgiopoulos, Michael
1997-04-01
Accurate total system electrical load forecasting is a necessary part of resource management for power generation companies. The better the hourly load forecast, the more closely the power generation assets of the company can be configured to minimize the cost. Automating this process is a profitable goal and neural networks should provide an excellent means of doing the automation. However, prior to developing such a system, the optimal set of input parameters must be determined. The approach of this research was to determine what those inputs should be through a parametric study of potentially good inputs. Input parameters tested were ambient temperature, total electrical load, the day of the week, humidity, dew point temperature, daylight savings time, length of daylight, season, forecast light index and forecast wind velocity. For testing, a limited number of temperatures and total electrical loads were used as a basic reference input parameter set. Most parameters showed some forecasting improvement when added individually to the basic parameter set. Significantly, major improvements were exhibited with the day of the week, dew point temperatures, additional temperatures and loads, forecast light index and forecast wind velocity.
NASA Astrophysics Data System (ADS)
Yin, Shaohua; Lin, Guo; Li, Shiwei; Peng, Jinhui; Zhang, Libo
2016-09-01
Microwave heating has been applied in the field of drying rare earth carbonates to improve drying efficiency and reduce energy consumption. The effects of power density, material thickness and drying time on the weight reduction (WR) are studied using response surface methodology (RSM). The results show that RSM is feasible to describe the relationship between the independent variables and weight reduction. Based on the analysis of variance (ANOVA), the model is in accordance with the experimental data. The optimum experiment conditions are power density 6 w/g, material thickness 15 mm and drying time 15 min, resulting in an experimental weight reduction of 73%. Comparative experiments show that microwave drying has the advantages of rapid dehydration and energy conservation. Particle analysis shows that the size distribution of rare earth carbonates after microwave drying is more even than those in an oven. Based on these findings, microwave heating technology has an important meaning to energy-saving and improvement of production efficiency for rare earth smelting enterprises and is a green heating process.
Energy Conservation Using Dynamic Voltage Frequency Scaling for Computational Cloud
Florence, A. Paulin; Shanthi, V.; Simon, C. B. Sunil
2016-01-01
Cloud computing is a new technology which supports resource sharing on a “Pay as you go” basis around the world. It provides various services such as SaaS, IaaS, and PaaS. Computation is a part of IaaS and the entire computational requests are to be served efficiently with optimal power utilization in the cloud. Recently, various algorithms are developed to reduce power consumption and even Dynamic Voltage and Frequency Scaling (DVFS) scheme is also used in this perspective. In this paper we have devised methodology which analyzes the behavior of the given cloud request and identifies the associated type of algorithm. Once the type of algorithm is identified, using their asymptotic notations, its time complexity is calculated. Using best fit strategy the appropriate host is identified and the incoming job is allocated to the victimized host. Using the measured time complexity the required clock frequency of the host is measured. According to that CPU frequency is scaled up or down using DVFS scheme, enabling energy to be saved up to 55% of total Watts consumption. PMID:27239551
Development of Activity-based Cost Functions for Cellulase, Invertase, and Other Enzymes
NASA Astrophysics Data System (ADS)
Stowers, Chris C.; Ferguson, Elizabeth M.; Tanner, Robert D.
As enzyme chemistry plays an increasingly important role in the chemical industry, cost analysis of these enzymes becomes a necessity. In this paper, we examine the aspects that affect the cost of enzymes based upon enzyme activity. The basis for this study stems from a previously developed objective function that quantifies the tradeoffs in enzyme purification via the foam fractionation process (Cherry et al., Braz J Chem Eng 17:233-238, 2000). A generalized cost function is developed from our results that could be used to aid in both industrial and lab scale chemical processing. The generalized cost function shows several nonobvious results that could lead to significant savings. Additionally, the parameters involved in the operation and scaling up of enzyme processing could be optimized to minimize costs. We show that there are typically three regimes in the enzyme cost analysis function: the low activity prelinear region, the moderate activity linear region, and high activity power-law region. The overall form of the cost analysis function appears to robustly fit the power law form.
Energy Conservation Using Dynamic Voltage Frequency Scaling for Computational Cloud.
Florence, A Paulin; Shanthi, V; Simon, C B Sunil
2016-01-01
Cloud computing is a new technology which supports resource sharing on a "Pay as you go" basis around the world. It provides various services such as SaaS, IaaS, and PaaS. Computation is a part of IaaS and the entire computational requests are to be served efficiently with optimal power utilization in the cloud. Recently, various algorithms are developed to reduce power consumption and even Dynamic Voltage and Frequency Scaling (DVFS) scheme is also used in this perspective. In this paper we have devised methodology which analyzes the behavior of the given cloud request and identifies the associated type of algorithm. Once the type of algorithm is identified, using their asymptotic notations, its time complexity is calculated. Using best fit strategy the appropriate host is identified and the incoming job is allocated to the victimized host. Using the measured time complexity the required clock frequency of the host is measured. According to that CPU frequency is scaled up or down using DVFS scheme, enabling energy to be saved up to 55% of total Watts consumption.
Wheel configurations for combined energy storage and attitude control systems
NASA Technical Reports Server (NTRS)
Oglevie, R. E.
1985-01-01
Integrated power and attitude control system (IPACS) studies performed over a decade ago established the feasibility of simultaneously storing electrical energy in wheels and utilizing the resulting momentum for spacecraft attitude control. It was shown that such a system possessed many advantages over other contemporary energy storage and attitude control systems in many applications. More recent technology advances in composite rotors, magnetic bearings, and power control electronics have triggered new optimism regarding the feasibility and merits of such a system. This paper presents the results of a recent study whose focus was to define an advanced IPACS and to evaluate its merits for the Space Station application. Emphasis is given to the selection of the wheel configuration to perform the combined functions. A component design concept is developed to establish the system performance capability. A system-level trade study, including life-cycle costing, is performed to define the merits of the system relative to two other candidate systems. It is concluded that an advanced IPACS concept is not only feasible but offers substantial savings in mass and life-cycle cost.
Compressed air production with waste heat utilization in industry
NASA Astrophysics Data System (ADS)
Nolting, E.
1984-06-01
The centralized power-heat coupling (PHC) technique using block heating power stations, is presented. Compressed air production in PHC technique with internal combustion engine drive achieves a high degree of primary energy utilization. Cost savings of 50% are reached compared to conventional production. The simultaneous utilization of compressed air and heat is especially interesting. A speed regulated drive via an internal combustion motor gives a further saving of 10% to 20% compared to intermittent operation. The high fuel utilization efficiency ( 80%) leads to a pay off after two years for operation times of 3000 hr.
Voltage Controller Saves Energy, Prolongs Life of Motors
NASA Technical Reports Server (NTRS)
2007-01-01
In 1985, Power Efficiency Corporation of Las Vegas licensed NASA voltage controller technology from Marshall Space Flight Center. In the following years, Power Efficiency made patented improvements to the technology and marketed the resulting products throughout the world as the Performance Controller and the Power Efficiency energy-saving soft start. Soft start gradually introduces power to an electric motor, thus eliminating the harsh, violent mechanical stresses of having the device go from a dormant state to one of full activity; prevents it from running too hot; and increases the motor's lifetime. The product can pay for itself through the reduction in electricity consumed (according to Power Efficiency, within 3 years), depending on the duty cycle of the motor and the prevailing power rates. In many instances, the purchaser is eligible for special utility rebates for the environmental protection it provides. Common applications of Power Efficiency's soft start include mixers, grinders, granulators, conveyors, crushers, stamping presses, injection molders, elevators with MG sets, and escalators. The device has been retrofitted onto equipment at major department store chains, hotels, airports, universities, and for various manufacturers
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Must I adopt and follow written policies and procedures in exercising fiduciary powers? 550.140 Section 550.140 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers...
Investigation and optimization of the depth of flue gas heat recovery in surface heat exchangers
NASA Astrophysics Data System (ADS)
Bespalov, V. V.; Bespalov, V. I.; Melnikov, D. V.
2017-09-01
Economic issues associated with designing deep flue gas heat recovery units for natural gas-fired boilers are examined. The governing parameter affecting the performance and cost of surface-type condensing heat recovery heat exchangers is the heat transfer surface area. When firing natural gas, the heat recovery depth depends on the flue gas temperature at the condenser outlet and determines the amount of condensed water vapor. The effect of the outlet flue gas temperature in a heat recovery heat exchanger on the additionally recovered heat power is studied. A correlation has been derived enabling one to determine the best heat recovery depth (or the final cooling temperature) maximizing the anticipated reduced annual profit of a power enterprise from implementation of energy-saving measures. Results of optimization are presented for a surface-type condensing gas-air plate heat recovery heat exchanger for the climatic conditions and the economic situation in Tomsk. The predictions demonstrate that it is economically feasible to design similar heat recovery heat exchangers for a flue gas outlet temperature of 10°C. In this case, the payback period for the investment in the heat recovery heat exchanger will be 1.5 years. The effect of various factors on the optimal outlet flue gas temperature was analyzed. Most climatic, economical, or technological factors have a minor effect on the best outlet temperature, which remains between 5 and 20°C when varying the affecting factors. The derived correlation enables us to preliminary estimate the outlet (final) flue gas temperature that should be used in designing the heat transfer surface of a heat recovery heat exchanger for a gas-fired boiler as applied to the specific climatic conditions.
Analysis of power gating in different hierarchical levels of 2MB cache, considering variation
NASA Astrophysics Data System (ADS)
Jafari, Mohsen; Imani, Mohsen; Fathipour, Morteza
2015-09-01
This article reintroduces power gating technique in different hierarchical levels of static random-access memory (SRAM) design including cell, row, bank and entire cache memory in 16 nm Fin field effect transistor. Different structures of SRAM cells such as 6T, 8T, 9T and 10T are used in design of 2MB cache memory. The power reduction of the entire cache memory employing cell-level optimisation is 99.7% with the expense of area and other stability overheads. The power saving of the cell-level optimisation is 3× (1.2×) higher than power gating in cache (bank) level due to its superior selectivity. The access delay times are allowed to increase by 4% in the same energy delay product to achieve the best power reduction for each supply voltages and optimisation levels. The results show the row-level power gating is the best for optimising the power of the entire cache with lowest drawbacks. Comparisons of cells show that the cells whose bodies have higher power consumption are the best candidates for power gating technique in row-level optimisation. The technique has the lowest percentage of saving in minimum energy point (MEP) of the design. The power gating also improves the variation of power in all structures by at least 70%.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurnik, Charles W.; Tiessen, Alex
Retrocommissioning (RCx) is a systematic process for optimizing energy performance in existing buildings. It specifically focuses on improving the control of energy-using equipment (e.g., heating, ventilation, and air conditioning [HVAC] equipment and lighting) and typically does not involve equipment replacement. Field results have shown proper RCx can achieve energy savings ranging from 5 percent to 20 percent, with a typical payback of two years or less (Thorne 2003). The method presented in this protocol provides direction regarding: (1) how to account for each measure's specific characteristics and (2) how to choose the most appropriate savings verification approach.
Energy-Saving Optimization of Water Supply Pumping Station Life Cycle Based on BIM Technology
NASA Astrophysics Data System (ADS)
Qun, Miao; Wang, Jiayuan; Liu, Chao
2017-12-01
In the urban water supply system, pump station is the main unit of energy consumption. In the background of pushing forward the informatization in China, using BIM technology in design, construction and operations of water supply pumping station, can break through the limitations of the traditional model and effectively achieve the goal of energy conservation and emissions reduction. This work researches the way to solve energy-saving optimization problems in the process of whole life cycle of water supply pumping station based on BIM technology, and put forward the feasible strategies of BIM application in order to realize the healthy and sustainable development goals by establishing the BIM model of water supply pumping station of Qingdao Guzhenkou water supply project.
Olayiwola, J. Nwando; Raffoul, Melanie
2016-01-01
More than 43 million people worldwide have been forcibly displaced from their homes as a result of conflict and persecution, over 50% of whom are women and 41% are children. The United Nations estimates that two-thirds of the world's refugees have been in exile for over 5 years, and more than half are in urban environments, as opposed to camps. Therefore, long-term strategies for healthcare in receiving countries are needed. The unique challenges facing refugee women as they seek safe and stable living situations are compelling. A system that optimizes the health of women refugees has significant implications for the rest of the family. PMID:29546169
Computationally efficient stochastic optimization using multiple realizations
NASA Astrophysics Data System (ADS)
Bayer, P.; Bürger, C. M.; Finkel, M.
2008-02-01
The presented study is concerned with computationally efficient methods for solving stochastic optimization problems involving multiple equally probable realizations of uncertain parameters. A new and straightforward technique is introduced that is based on dynamically ordering the stack of realizations during the search procedure. The rationale is that a small number of critical realizations govern the output of a reliability-based objective function. By utilizing a problem, which is typical to designing a water supply well field, several variants of this "stack ordering" approach are tested. The results are statistically assessed, in terms of optimality and nominal reliability. This study demonstrates that the simple ordering of a given number of 500 realizations while applying an evolutionary search algorithm can save about half of the model runs without compromising the optimization procedure. More advanced variants of stack ordering can, if properly configured, save up to more than 97% of the computational effort that would be required if the entire number of realizations were considered. The findings herein are promising for similar problems of water management and reliability-based design in general, and particularly for non-convex problems that require heuristic search techniques.
Research on PM2.5 emission reduction path of China ‘s electric power industry based on DEA model
NASA Astrophysics Data System (ADS)
Jin, Yanming; Yang, Fan; Liu, Jun
2018-02-01
Based on the theory of data envelopment analysis, this study constructs the environmental performance evaluation model of the power industry, analyzes the performance of development of clean energy, the implementation of electricity replacement, and the development of coal-fired energy-saving and emission-reducing measures. Put forward technology path to reduce emission in the future. The results show that (1) improving the proportion of coal for power generation, speeding up the replacement of electricity is the key to solve the haze in China. (2) With the photovoltaic and other new energy power generation costs gradually reduced and less limit from thermal energy, by final of “thirteenth five-years plan”, the economy of clean energy will surpass thermal energy-saving emission reduction. (3) After 2025, the economy of the electricity replacement will be able to show.
1983-01-01
formulated to achieve weight savings, successfully completed a 100 hour pump test with no loss of fluid viscosity. Initial synthetic approaches to...acquisition cost savings in one concept and 51 percent weight savings in another. (9) (U) Advanced 3D Materials: Demonstrated the feasibility of using...in the gas phase. This research will provide the basis for future laser weapons that are more efficient, powerful, and lighter weight than infrared
A CLS-based survivable and energy-saving WDM-PON architecture
NASA Astrophysics Data System (ADS)
Zhu, Min; Zhong, Wen-De; Zhang, Zhenrong; Luan, Feng
2013-11-01
We propose and demonstrate an improved survivable and energy-saving WDM-PON with colorless ONUs. It incorporates both energy-saving and self-healing operations. A simple effective energy-saving scheme is proposed by including an energy-saving control unit in the OLT and a control unit at each ONU. The energy-saving scheme realizes both dozing and sleep (offline) modes, which greatly improves the energy-saving efficiency for WDM-PONs. An intelligent protection switching scheme is designed in the OLT, which can distinguish if an ONU is in dozing/sleep (offline) state or a fiber is faulty. Moreover, by monitoring the optical power of each channel on both working and protection paths, the OLT can know the connection status of every fiber path, thus facilitating an effective protection switching and a faster failure recovery. The improved WDM-PON architecture not only significantly reduces energy consumption, but also performs self-healing operation in practical operation scenarios. The scheme feasibility is experimentally verified with 10 Gbit/s downstream and 1.25 Gbit/s upstream transmissions. We also examine the energy-saving efficiency of our proposed energy-saving scheme by simulation, which reveals that energy saving mainly arises from the dozing mode, not from the sleep mode when the ONU is in the online state.
Fuel-Cell-Powered Electric Motor Drive Analyzed for a Large Airplane
NASA Technical Reports Server (NTRS)
Brown, Gerald V.; Choi, Benjamin B.
2005-01-01
Because of its high efficiency, fuel cell technology may be used to launch a new generation of more-electric aeropropulsion and power systems for future aircraft. Electric-motor-driven airplanes using fuel-cell powerplants would be beneficial to the environment because of fuel savings, low noise, and zero carbon-dioxide emissions. In spite of the fuel cell s efficiency benefit, to produce the same shaft drive power, a fuel cell- powered electric-drive system must be definitely heavier than a turbine-drive system. However, the fuel-cell system s overall efficiency from fuel-to-shaft power is higher than for a turbine-drive system. This means that the fuel consumption rate could be lower than for a conventional system. For heavier, fuel-laden planes for longer flights, we might achieve substantial fuel savings. In the airplane industry, in fact, an efficiency gain of even a few percentage points can make a major economic difference in operating costs.
Demonstration Program for Low-Cost, High-Energy-Saving Dynamic Windows
2014-09-01
Design The scope of this project was to demonstrate the impact of dynamic windows via energy savings and HVAC peak-load reduction; to validate the...temperature and glare. While the installed dynamic window system does not directly control the HVAC or lighting of the facility, those systems are designed ...optimize energy efficiency and HVAC load management. The conversion to inoperable windows caused an unforeseen reluctance to accept the design and
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ding, Fei; Nagarajan, Adarsh; Chakraborty, Sudipta
This report presents an impact assessment study of distributed photovoltaic (PV) with smart inverter Volt-VAR control on conservation voltage reduction (CVR) energy savings and distribution system power quality. CVR is a methodology of flattening and lowering a distribution system voltage profile in order to conserve energy. Traditional CVR relies on operating utility voltage regulators and switched capacitors. However, with the increased penetration of distributed PV systems, smart inverters provide the new opportunity to control local voltage and power factor by regulating the reactive power output, leading to a potential increase in CVR energy savings. This report proposes a methodology tomore » implement CVR scheme by operating voltage regulators, capacitors, and autonomous smart inverter Volt-VAR control in order to achieve increased CVR benefit. Power quality is an important consideration when operating a distribution system, especially when implementing CVR. It is easy to measure the individual components that make up power quality, but a comprehensive method to incorporate all of these values into a single score has yet to be undertaken. As a result, this report proposes a power quality scoring mechanism to measure the relative power quality of distribution systems using a single number, which is aptly named the 'power quality score' (PQS). Both the CVR and PQS methodologies were applied to two distribution system models, one obtained from the Hawaiian Electric Company (HECO) and another obtained from Pacific Gas and Electric (PG&E). These two models were converted to the OpenDSS platform using previous model conversion tools that were developed by NREL. Multiple scenarios including various PV penetration levels and smart inverter densities were simulated to analyze the impact of smart inverter Volt-VAR support on CVR energy savings and feeder power quality. In order to analyze the CVR benefit and PQS, an annual simulation was conducted for each scenario.« less
Multi-objective optimization design and experimental investigation of centrifugal fan performance
NASA Astrophysics Data System (ADS)
Zhang, Lei; Wang, Songling; Hu, Chenxing; Zhang, Qian
2013-11-01
Current studies of fan performance optimization mainly focus on two aspects: one is to improve the blade profile, and another is only to consider the influence of single impeller structural parameter on fan performance. However, there are few studies on the comprehensive effect of the key parameters such as blade number, exit stagger angle of blade and the impeller outlet width on the fan performance. The G4-73 backward centrifugal fan widely used in power plants is selected as the research object. Based on orthogonal design and BP neural network, a model for predicting the centrifugal fan performance parameters is established, and the maximum relative errors of the total pressure and efficiency are 0.974% and 0.333%, respectively. Multi-objective optimization of total pressure and efficiency of the fan is conducted with genetic algorithm, and the optimum combination of impeller structural parameters is proposed. The optimized parameters of blade number, exit stagger angle of blade and the impeller outlet width are seperately 14, 43.9°, and 21 cm. The experiments on centrifugal fan performance and noise are conducted before and after the installation of the new impeller. The experimental results show that with the new impeller, the total pressure of fan increases significantly in total range of the flow rate, and the fan efficiency is improved when the relative flow is above 75%, also the high efficiency area is broadened. Additionally, in 65% -100% relative flow, the fan noise is reduced. Under the design operating condition, total pressure and efficiency of the fan are improved by 6.91% and 0.5%, respectively. This research sheds light on the considering of comprehensive effect of impeller structrual parameters on fan performance, and a new impeller can be designed to satisfy the engineering demand such as energy-saving, noise reduction or solving air pressure insufficiency for power plants.
The impact of translucent fabric shades and control strategies on energy savings and visual quality
NASA Astrophysics Data System (ADS)
Wankanapon, Pimonmart
Translucent fabric shades provide opportunities for building occupants to control sunlight penetration for heat reduction, thermal comfort, and visual quality. Regulating shades affects building energy and can potentially reduce the size of mechanical cooling systems. Shades are not normally included in energy model studies during the design process, even though shades potential impact energy use. This is because the occupants normally leave shades closed a large fraction of the time, but models are generally performed with no shades. Automatic shade control is now available, so it is necessary to understand the impact of shades on visual quality and their energy saving potential in order to optimize their overall performance. There are very limited studies that have address shades and their integrated performance on energy consumption and visual quality. Most of these do not reflected modern shade types and their application. The goals of this study are: First, to determine the impact of shades on total, heating, cooling and lighting energy savings with different design and operation parameters. Second, to study and develop different automatic shade control strategies to promote and optimize energy savings and visual quality. A simulation-based approach using EnergyPlus in a parametric study provide better understanding energy savings under different shade conditions. The parametric runs addressed various building parameters such as geometry, orientation, site climate, glazing/shade properties, and shade control strategies with integrated lighting control. The impact of shades was determined for total building and space heating, cooling and lighting energy savings. The effect of shades on visual quality was studied using EnergyPlus, AGI32 and DAYSIM for several indices such as daylight glare index (DGI), work plane illuminance, luminance ratios and view. Different shade control strategies and integrated lighting control were considered with two translucent fabric shade colors. The results clearly show the benefit of automatic shade control strategies with integrated lighting control over a condition when shades are closed all day. The main contributor to the total energy savings is from lighting energy savings, followed by cooling energy savings. Shades provide greater benefit in a hot climate and in a moderate climate than in a cold climate. Different control strategies provide savings in the range of 7-35% for annual total space energy with higher savings with light colored shades. Control strategies of shades should be selected and optimized based on climate, orientation, window area, and window/shade properties. High performance glazings, when equipped with shades, show lower energy savings when compared to standard glazings. High transmittance/reflectance shades, such as white shades, perform better than dark shades in most of the cases due to higher lighting energy savings obtained with the automatic electric lighting control and the resulting cooling energy savings from rejection of some solar energy and a reduction in the heat from lights. A South orientation showed the least benefit of automatic control of shades when compare to other orientations due to the large fraction of time shades are required to provide visual comfort. Under automatic shade control, energy savings are higher the more often the shades can be raised. The different automatic control strategies present tradeoffs between energy savings and comfort. With regard to visual quality, daylight quality assessments on view, glare, luminance ratios, and UDI can be used to assess shade control strategies. Automatic shade control can increase the number of view hours while controlling sunlight penetration. With automatic shade control, more daylight hours can be provided within the beneficial range of 100-2000 lux compared to shades that are closed all day. For a person facing the window, discomfort glare is likely to increase the more often the shades are raised. Keeping the shades down ensures an acceptable glare condition, but limits energy savings. Luminance ratios are another metric that can be used to assess shade performance. With white shades, the luminance ratios between the task and proximate surfaces are improved. Dark shades help improve the luminance ratios between the task and distant surfaces. When the shades are left open, even with no direct sunlight in the space, task to window luminance ratios will often exceed 1:10.
A simple tool for estimating city-wide annual electrical energy savings from cooler surfaces
Pomerantz, Melvin; Rosado, Pablo J.; Levinson, Ronnen
2015-07-26
We present a simple method to estimate the maximum possible energy saving that might be achieved by increasing the albedo of surfaces in a large city. We restrict this to the "indirect effect", the cooling of outside air that lessens the demand for air conditioning (AC). Given the power demand of the electric utilities and data about the city, we can use a single linear equation to estimate the maximum saving. For example, the result for an albedo change of 0.2 of pavements in a typical warm city in California, such as Sacramento, is that the saving is less thanmore » about 2 kWh per m 2 per year. This may help decision makers choose which heat island mitigation techniques are economical from an energy-saving perspective.« less
An optimal FFT-based anisotropic power spectrum estimator
NASA Astrophysics Data System (ADS)
Hand, Nick; Li, Yin; Slepian, Zachary; Seljak, Uroš
2017-07-01
Measurements of line-of-sight dependent clustering via the galaxy power spectrum's multipole moments constitute a powerful tool for testing theoretical models in large-scale structure. Recent work shows that this measurement, including a moving line-of-sight, can be accelerated using Fast Fourier Transforms (FFTs) by decomposing the Legendre polynomials into products of Cartesian vectors. Here, we present a faster, optimal means of using FFTs for this measurement. We avoid redundancy present in the Cartesian decomposition by using a spherical harmonic decomposition of the Legendre polynomials. With this method, a given multipole of order l requires only 2l+1 FFTs rather than the (l+1)(l+2)/2 FFTs of the Cartesian approach. For the hexadecapole (l = 4), this translates to 40% fewer FFTs, with increased savings for higher l. The reduction in wall-clock time enables the calculation of finely-binned wedges in P(k,μ), obtained by computing multipoles up to a large lmax and combining them. This transformation has a number of advantages. We demonstrate that by using non-uniform bins in μ, we can isolate plane-of-sky (angular) systematics to a narrow bin at 0μ simeq while eliminating the contamination from all other bins. We also show that the covariance matrix of clustering wedges binned uniformly in μ becomes ill-conditioned when combining multipoles up to large values of lmax, but that the problem can be avoided with non-uniform binning. As an example, we present results using lmax=16, for which our procedure requires a factor of 3.4 fewer FFTs than the Cartesian method, while removing the first μ bin leads only to a 7% increase in statistical error on f σ8, as compared to a 54% increase with lmax=4.
12 CFR 550.310 - What if the FDIC does not insure the deposits?
Code of Federal Regulations, 2013 CFR
2013-01-01
... FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Funds Awaiting Investment Or Distribution § 550.310 What if the FDIC does not insure the deposits? If the FDIC does not insure the entire...
12 CFR 550.310 - What if the FDIC does not insure the deposits?
Code of Federal Regulations, 2012 CFR
2012-01-01
... FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Funds Awaiting Investment Or Distribution § 550.310 What if the FDIC does not insure the deposits? If the FDIC does not insure the entire...
12 CFR 550.310 - What if the FDIC does not insure the deposits?
Code of Federal Regulations, 2014 CFR
2014-01-01
... FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Funds Awaiting Investment Or Distribution § 550.310 What if the FDIC does not insure the deposits? If the FDIC does not insure the entire...
12 CFR 150.310 - What if the FDIC does not insure the deposits?
Code of Federal Regulations, 2014 CFR
2014-01-01
... FIDUCIARY POWERS OF FEDERAL SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Funds Awaiting Investment Or Distribution § 150.310 What if the FDIC does not insure the deposits? If the FDIC does not insure the entire...
12 CFR 550.310 - What if the FDIC does not insure the deposits?
Code of Federal Regulations, 2011 CFR
2011-01-01
... FIDUCIARY POWERS OF SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Funds Awaiting Investment Or Distribution § 550.310 What if the FDIC does not insure the deposits? If the FDIC does not insure the entire...
12 CFR 150.310 - What if the FDIC does not insure the deposits?
Code of Federal Regulations, 2012 CFR
2012-01-01
... FIDUCIARY POWERS OF FEDERAL SAVINGS ASSOCIATIONS Exercising Fiduciary Powers Funds Awaiting Investment Or Distribution § 150.310 What if the FDIC does not insure the deposits? If the FDIC does not insure the entire...
Amand, L; Carlsson, B
2013-01-01
Ammonium feedback control is increasingly used to determine the dissolved oxygen (DO) set-point in aerated activated sludge processes for nitrogen removal. This study compares proportional-integral (PI) ammonium feedback control with a DO profile created from a mathematical minimisation of the daily air flow rate. All simulated scenarios are set to reach the same treatment level of ammonium, based on a daily average concentration. The influent includes daily variations only and the model has three aerated zones. Comparisons are made at different plant loads and DO concentrations, and the placement of the ammonium sensor is investigated. The results show that ammonium PI control can achieve the best performance if the DO set-point is limited at a maximum value and with little integral action in the controller. Compared with constant DO control the best-performing ammonium controller can achieve 1-3.5% savings in the air flow rate, while the optimal solution can achieve a 3-7% saving. Energy savings are larger when operating at higher DO concentrations.
NASA Astrophysics Data System (ADS)
Lu, Qiheng; Feng, Xiaoyun
2013-03-01
After analyzing the working principle of the four-aspect fixed autoblock system, an energy-saving control model was created based on the dynamics equations of the trains in order to study the energy-saving optimal control strategy of trains in a following operation. Besides the safety and punctuality, the main aims of the model were the energy consumption and the time error. Based on this model, the static and dynamic speed restraints under a four-aspect fixed autoblock system were put forward. The multi-dimension parallel genetic algorithm (GA) and the external punishment function were adopted to solve this problem. By using the real number coding and the strategy of ramps divided into three parts, the convergence of GA was speeded up and the length of chromosomes was shortened. A vector of Gaussian random disturbance with zero mean was superposed to the mutation operator. The simulation result showed that the method could reduce the energy consumption effectively based on safety and punctuality.
Method and Process Development of Advanced Atmospheric Plasma Spraying for Thermal Barrier Coatings
NASA Astrophysics Data System (ADS)
Mihm, Sebastian; Duda, Thomas; Gruner, Heiko; Thomas, Georg; Dzur, Birger
2012-06-01
Over the last few years, global economic growth has triggered a dramatic increase in the demand for resources, resulting in steady rise in prices for energy and raw materials. In the gas turbine manufacturing sector, process optimizations of cost-intensive production steps involve a heightened potential of savings and form the basis for securing future competitive advantages in the market. In this context, the atmospheric plasma spraying (APS) process for thermal barrier coatings (TBC) has been optimized. A constraint for the optimization of the APS coating process is the use of the existing coating equipment. Furthermore, the current coating quality and characteristics must not change so as to avoid new qualification and testing. Using experience in APS and empirically gained data, the process optimization plan included the variation of e.g. the plasma gas composition and flow-rate, the electrical power, the arrangement and angle of the powder injectors in relation to the plasma jet, the grain size distribution of the spray powder and the plasma torch movement procedures such as spray distance, offset and iteration. In particular, plasma properties (enthalpy, velocity and temperature), powder injection conditions (injection point, injection speed, grain size and distribution) and the coating lamination (coating pattern and spraying distance) are examined. The optimized process and resulting coating were compared to the current situation using several diagnostic methods. The improved process significantly reduces costs and achieves the requirement of comparable coating quality. Furthermore, a contribution was made towards better comprehension of the APS of ceramics and the definition of a better method for future process developments.
Socially optimal replacement of conventional with electric vehicles for the US household fleet
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kontou, Eleftheria; Yin, Yafeng; Lin, Zhenhong
In this study, a framework is proposed for minimizing the societal cost of replacing gas-powered household passenger cars with battery electric ones (BEVs). The societal cost consists of operational costs of heterogeneous driving patterns' cars, the government investments for charging deployment, and monetized environmental externalities. The optimization framework determines the timeframe needed for conventional vehicles to be replaced with BEVs. It also determines the BEVs driving range during the planning timeframe, as well as the density of public chargers deployed on a linear transportation network over time. We leverage datasets that represent U.S. household driving patterns, as well as themore » automobile and the energy markets, to apply the model. Results indicate that it takes 8 years for 80% of our conventional vehicle sample to be replaced with electric vehicles, under the base case scenario. The socially optimal all-electric driving range is 204 miles, with chargers placed every 172 miles on a linear corridor. All of the public chargers should be deployed at the beginning of the planning horizon to achieve greater savings over the years. Sensitivity analysis reveals that the timeframe for the socially optimal conversion of 80% of the sample varies from 6 to 12 years. The optimal decision variables are sensitive to battery pack and vehicle body cost, gasoline cost, the discount rate, and conventional vehicles' fuel economy. In conclusion, faster conventional vehicle replacement is achieved when the gasoline cost increases, electricity cost decreases, and battery packs become cheaper over the years.« less
Socially optimal replacement of conventional with electric vehicles for the US household fleet
Kontou, Eleftheria; Yin, Yafeng; Lin, Zhenhong; ...
2017-04-05
In this study, a framework is proposed for minimizing the societal cost of replacing gas-powered household passenger cars with battery electric ones (BEVs). The societal cost consists of operational costs of heterogeneous driving patterns' cars, the government investments for charging deployment, and monetized environmental externalities. The optimization framework determines the timeframe needed for conventional vehicles to be replaced with BEVs. It also determines the BEVs driving range during the planning timeframe, as well as the density of public chargers deployed on a linear transportation network over time. We leverage datasets that represent U.S. household driving patterns, as well as themore » automobile and the energy markets, to apply the model. Results indicate that it takes 8 years for 80% of our conventional vehicle sample to be replaced with electric vehicles, under the base case scenario. The socially optimal all-electric driving range is 204 miles, with chargers placed every 172 miles on a linear corridor. All of the public chargers should be deployed at the beginning of the planning horizon to achieve greater savings over the years. Sensitivity analysis reveals that the timeframe for the socially optimal conversion of 80% of the sample varies from 6 to 12 years. The optimal decision variables are sensitive to battery pack and vehicle body cost, gasoline cost, the discount rate, and conventional vehicles' fuel economy. In conclusion, faster conventional vehicle replacement is achieved when the gasoline cost increases, electricity cost decreases, and battery packs become cheaper over the years.« less
Optimizing the Placement of Burnable Poisons in PWRs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yilmaz, Serkan; Ivanov, Kostadin; Levine, Samuel
2005-07-15
The principal focus of this work is on developing a practical tool for designing the minimum amount of burnable poisons (BPs) for a pressurized water reactor using a typical Three Mile Island Unit 1 2-yr cycle as the reference design. The results of this study are to be applied to future reload designs. A new method, the Modified Power Shape Forced Diffusion (MPSFD) method, is presented that initially computes the BP cross section to force the power distribution into a desired shape. The method employs a simple formula that expresses the BP cross section as a function of the differencemore » between the calculated radial power distributions (RPDs) and the limit set for the maximum RPD. This method places BPs into all fresh fuel assemblies (FAs) having an RPD greater than the limit. The MPSFD method then reduces the BP content by reducing the BPs in fresh FAs with the lowest RPDs. Finally, the minimum BP content is attained via a heuristic fine-tuning procedure.This new BP design program has been automated by incorporating the new MPSFD method in conjunction with the heuristic fine-tuning program. The program has automatically produced excellent results for the reference core, and has the potential to reduce fuel costs and save manpower.« less
Financing Home Energy and Renewable Energy Improvements with FHA PowerSaver Loans (Fact Sheet)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
2014-07-01
This fact sheet is a revision to the PowerSaver Loan Benefits fact sheet from April 2014. It describes how the U.S. Department of Housing and Urban Development (HUD) PowerSaver Loan Program offers borrowers low-cost FHA-insured loans to make energy-saving improvements to their homes.
Effect of Voltage Level on Power System Design for Solar Electric Propulsion Missions
NASA Technical Reports Server (NTRS)
Kerslake, Thomas W.
2003-01-01
This paper presents study results quantifying the benefits of higher voltage, electric power system designs for a typical solar electric propulsion spacecraft Earth orbiting mission. A conceptual power system architecture was defined and design points were generated for system voltages of 28-V, 50-V, 120-V, and 300-V using state-of-the-art or advanced technologies. A 300-V 'direct-drive' architecture was also analyzed to assess the benefits of directly powering the electric thruster from the photovoltaic array without up-conversion. Fortran and spreadsheet computational models were exercised to predict the performance and size power system components to meet spacecraft mission requirements. Pertinent space environments, such as electron and proton radiation, were calculated along the spiral trajectory. In addition, a simplified electron current collection model was developed to estimate photovoltaic array losses for the orbital plasma environment and that created by the thruster plume. The secondary benefits of power system mass savings for spacecraft propulsion and attitude control systems were also quantified. Results indicate that considerable spacecraft wet mass savings were achieved by the 300-V and 300-V direct-drive architectures.
Real Time Energy Management Control Strategies for Hybrid Powertrains
NASA Astrophysics Data System (ADS)
Zaher, Mohamed Hegazi Mohamed
In order to improve fuel efficiency and reduce emissions of mobile vehicles, various hybrid power-train concepts have been developed over the years. This thesis focuses on embedded control of hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy for continuous operations. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, or the motion is driven by gravitational force, or load driven. There are three main concepts for regernerative energy storing devices in hybrid vehicles: electric, hydraulic, and flywheel. The real time control challenge is to balance the system power demand from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle, while making optimal use of the energy saving opportunities in a given operational, often repetitive cycle. In the worst case scenario, only engine is used and hybrid system completely disabled. A rule based control is developed and tuned for different work cycles and linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the machine and its position via GPS, and maps them to the gains.
A Mixed Integer Linear Program for Solving a Multiple Route Taxi Scheduling Problem
NASA Technical Reports Server (NTRS)
Montoya, Justin Vincent; Wood, Zachary Paul; Rathinam, Sivakumar; Malik, Waqar Ahmad
2010-01-01
Aircraft movements on taxiways at busy airports often create bottlenecks. This paper introduces a mixed integer linear program to solve a Multiple Route Aircraft Taxi Scheduling Problem. The outputs of the model are in the form of optimal taxi schedules, which include routing decisions for taxiing aircraft. The model extends an existing single route formulation to include routing decisions. An efficient comparison framework compares the multi-route formulation and the single route formulation. The multi-route model is exercised for east side airport surface traffic at Dallas/Fort Worth International Airport to determine if any arrival taxi time savings can be achieved by allowing arrivals to have two taxi routes: a route that crosses an active departure runway and a perimeter route that avoids the crossing. Results indicate that the multi-route formulation yields reduced arrival taxi times over the single route formulation only when a perimeter taxiway is used. In conditions where the departure aircraft are given an optimal and fixed takeoff sequence, accumulative arrival taxi time savings in the multi-route formulation can be as high as 3.6 hours more than the single route formulation. If the departure sequence is not optimal, the multi-route formulation results in less taxi time savings made over the single route formulation, but the average arrival taxi time is significantly decreased.
TRU Waste Management Program cost/schedule optimization analysis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Detamore, J.A.; Raudenbush, M.H.; Wolaver, R.W.
1985-10-01
The cost/schedule optimization task is a necessary function to insure that program goals and plans are optimized from a cost and schedule aspect. Results of this study will offer DOE information with which it can establish, within institutional constraints, the most efficient program for the long-term management and disposal of contact handled transuranic waste (CH-TRU). To this end, a comprehensive review of program cost/schedule tradeoffs has been made, to identify any major cost saving opportunities that may be realized by modification of current program plans. It was decided that all promising scenarios would be explored, and institutional limitations to implementationmore » would be described. Since a virtually limitless number of possible scenarios can be envisioned, it was necessary to distill these possibilities into a manageable number of alternatives. The resultant scenarios were described in the cost/schedule strategy and work plan document. Each scenario was compared with the base case: waste processing at the originating site; transport of CH-TRU wastes in TRUPACT; shipment of drums in 6-Packs; 25 year stored waste workoff; WIPP operational 10/88, with all sites shipping to WIPP beginning 10/88; and no processing at WIPP. Major savings were identified in two alternate scenarios: centralize waste processing at INEL and eliminate rail shipment of TRUPACT. No attempt was made to calculate savings due to combination of scenarios. 1 ref., 5 figs., 1 tab. (MHB)« less
Simplified installation of thrust bearings
NASA Technical Reports Server (NTRS)
Sensenbaugh, N. D.
1980-01-01
Special handling sleeve, key to method of installing thrust bearings, was developed for assembling bearings on shaft of low-pressure oxygen turbo-pump. Method eliminates cooling and vacuum-drying steps which saves time, while also eliminating possibility of corrosion formation. Procedure saves energy because it requires no liquid nitrogen for cooling shaft and no natural gas or electric power for operating vacuum oven.
12 CFR 560.30 - General lending and investment powers of Federal savings associations.
Code of Federal Regulations, 2010 CFR
2010-01-01
.... Commercial paper and corporate debt securities 5(c)(2)(D) Up to 35% of total assets. 2,3 Community...) None. 6 Finance leasing 5(c)(1)(B), 5(c)(2)(A), 5(c)(2)(B), 5(c)(2)(D) Based on purpose and property... corporate debt securities must be aggregated with the Federal savings association's investment in consumer...
Alternative Fuels Data Center: Propane Powers School Buses in Tuscaloosa,
Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus and Plug-In Electric Vehicles March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Electric Trolley Boosts Business in
Alternative Fuels Data Center: Recycled Cooking Oil Powers Biodiesel
Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of the front of a red truck Salt Lake City Buses Help Kansas City Save Money Nov. 12, 2011 Electric Trucks Deliver at Kansas City Schools Sept. 17 Electric Buses Aug. 21, 2010 Hybrid Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gohar, Y.; Nuclear Engineering Division
2005-05-01
In fusion reactors, the blanket design and its characteristics have a major impact on the reactor performance, size, and economics. The selection and arrangement of the blanket materials, dimensions of the different blanket zones, and different requirements of the selected materials for a satisfactory performance are the main parameters, which define the blanket performance. These parameters translate to a large number of variables and design constraints, which need to be simultaneously considered in the blanket design process. This represents a major design challenge because of the lack of a comprehensive design tool capable of considering all these variables to definemore » the optimum blanket design and satisfying all the design constraints for the adopted figure of merit and the blanket design criteria. The blanket design capabilities of the First Wall/Blanket/Shield Design and Optimization System (BSDOS) have been developed to overcome this difficulty and to provide the state-of-the-art research and design tool for performing blanket design analyses. This paper describes some of the BSDOS capabilities and demonstrates its use. In addition, the use of the optimization capability of the BSDOS can result in a significant blanket performance enhancement and cost saving for the reactor design under consideration. In this paper, examples are presented, which utilize an earlier version of the ITER solid breeder blanket design and a high power density self-cooled lithium blanket design for demonstrating some of the BSDOS blanket design capabilities.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gohar, Yousry
2005-05-15
In fusion reactors, the blanket design and its characteristics have a major impact on the reactor performance, size, and economics. The selection and arrangement of the blanket materials, dimensions of the different blanket zones, and different requirements of the selected materials for a satisfactory performance are the main parameters, which define the blanket performance. These parameters translate to a large number of variables and design constraints, which need to be simultaneously considered in the blanket design process. This represents a major design challenge because of the lack of a comprehensive design tool capable of considering all these variables to definemore » the optimum blanket design and satisfying all the design constraints for the adopted figure of merit and the blanket design criteria. The blanket design capabilities of the First Wall/Blanket/Shield Design and Optimization System (BSDOS) have been developed to overcome this difficulty and to provide the state-of-the-art research and design tool for performing blanket design analyses. This paper describes some of the BSDOS capabilities and demonstrates its use. In addition, the use of the optimization capability of the BSDOS can result in a significant blanket performance enhancement and cost saving for the reactor design under consideration. In this paper, examples are presented, which utilize an earlier version of the ITER solid breeder blanket design and a high power density self-cooled lithium blanket design for demonstrating some of the BSDOS blanket design capabilities.« less
Autopilot for frequency-modulation atomic force microscopy.
Kuchuk, Kfir; Schlesinger, Itai; Sivan, Uri
2015-10-01
One of the most challenging aspects of operating an atomic force microscope (AFM) is finding optimal feedback parameters. This statement applies particularly to frequency-modulation AFM (FM-AFM), which utilizes three feedback loops to control the cantilever excitation amplitude, cantilever excitation frequency, and z-piezo extension. These loops are regulated by a set of feedback parameters, tuned by the user to optimize stability, sensitivity, and noise in the imaging process. Optimization of these parameters is difficult due to the coupling between the frequency and z-piezo feedback loops by the non-linear tip-sample interaction. Four proportional-integral (PI) parameters and two lock-in parameters regulating these loops require simultaneous optimization in the presence of a varying unknown tip-sample coupling. Presently, this optimization is done manually in a tedious process of trial and error. Here, we report on the development and implementation of an algorithm that computes the control parameters automatically. The algorithm reads the unperturbed cantilever resonance frequency, its quality factor, and the z-piezo driving signal power spectral density. It analyzes the poles and zeros of the total closed loop transfer function, extracts the unknown tip-sample transfer function, and finds four PI parameters and two lock-in parameters for the frequency and z-piezo control loops that optimize the bandwidth and step response of the total system. Implementation of the algorithm in a home-built AFM shows that the calculated parameters are consistently excellent and rarely require further tweaking by the user. The new algorithm saves the precious time of experienced users, facilitates utilization of FM-AFM by casual users, and removes the main hurdle on the way to fully automated FM-AFM.
Autopilot for frequency-modulation atomic force microscopy
NASA Astrophysics Data System (ADS)
Kuchuk, Kfir; Schlesinger, Itai; Sivan, Uri
2015-10-01
One of the most challenging aspects of operating an atomic force microscope (AFM) is finding optimal feedback parameters. This statement applies particularly to frequency-modulation AFM (FM-AFM), which utilizes three feedback loops to control the cantilever excitation amplitude, cantilever excitation frequency, and z-piezo extension. These loops are regulated by a set of feedback parameters, tuned by the user to optimize stability, sensitivity, and noise in the imaging process. Optimization of these parameters is difficult due to the coupling between the frequency and z-piezo feedback loops by the non-linear tip-sample interaction. Four proportional-integral (PI) parameters and two lock-in parameters regulating these loops require simultaneous optimization in the presence of a varying unknown tip-sample coupling. Presently, this optimization is done manually in a tedious process of trial and error. Here, we report on the development and implementation of an algorithm that computes the control parameters automatically. The algorithm reads the unperturbed cantilever resonance frequency, its quality factor, and the z-piezo driving signal power spectral density. It analyzes the poles and zeros of the total closed loop transfer function, extracts the unknown tip-sample transfer function, and finds four PI parameters and two lock-in parameters for the frequency and z-piezo control loops that optimize the bandwidth and step response of the total system. Implementation of the algorithm in a home-built AFM shows that the calculated parameters are consistently excellent and rarely require further tweaking by the user. The new algorithm saves the precious time of experienced users, facilitates utilization of FM-AFM by casual users, and removes the main hurdle on the way to fully automated FM-AFM.
Autopilot for frequency-modulation atomic force microscopy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kuchuk, Kfir; Schlesinger, Itai; Sivan, Uri, E-mail: phsivan@tx.technion.ac.il
2015-10-15
One of the most challenging aspects of operating an atomic force microscope (AFM) is finding optimal feedback parameters. This statement applies particularly to frequency-modulation AFM (FM-AFM), which utilizes three feedback loops to control the cantilever excitation amplitude, cantilever excitation frequency, and z-piezo extension. These loops are regulated by a set of feedback parameters, tuned by the user to optimize stability, sensitivity, and noise in the imaging process. Optimization of these parameters is difficult due to the coupling between the frequency and z-piezo feedback loops by the non-linear tip-sample interaction. Four proportional-integral (PI) parameters and two lock-in parameters regulating these loopsmore » require simultaneous optimization in the presence of a varying unknown tip-sample coupling. Presently, this optimization is done manually in a tedious process of trial and error. Here, we report on the development and implementation of an algorithm that computes the control parameters automatically. The algorithm reads the unperturbed cantilever resonance frequency, its quality factor, and the z-piezo driving signal power spectral density. It analyzes the poles and zeros of the total closed loop transfer function, extracts the unknown tip-sample transfer function, and finds four PI parameters and two lock-in parameters for the frequency and z-piezo control loops that optimize the bandwidth and step response of the total system. Implementation of the algorithm in a home-built AFM shows that the calculated parameters are consistently excellent and rarely require further tweaking by the user. The new algorithm saves the precious time of experienced users, facilitates utilization of FM-AFM by casual users, and removes the main hurdle on the way to fully automated FM-AFM.« less
Achieving energy efficiency during collective communications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sundriyal, Vaibhav; Sosonkina, Masha; Zhang, Zhao
2012-09-13
Energy consumption has become a major design constraint in modern computing systems. With the advent of petaflops architectures, power-efficient software stacks have become imperative for scalability. Techniques such as dynamic voltage and frequency scaling (called DVFS) and CPU clock modulation (called throttling) are often used to reduce the power consumption of the compute nodes. To avoid significant performance losses, these techniques should be used judiciously during parallel application execution. For example, its communication phases may be good candidates to apply the DVFS and CPU throttling without incurring a considerable performance loss. They are often considered as indivisible operations although littlemore » attention is being devoted to the energy saving potential of their algorithmic steps. In this work, two important collective communication operations, all-to-all and allgather, are investigated as to their augmentation with energy saving strategies on the per-call basis. The experiments prove the viability of such a fine-grain approach. They also validate a theoretical power consumption estimate for multicore nodes proposed here. While keeping the performance loss low, the obtained energy savings were always significantly higher than those achieved when DVFS or throttling were switched on across the entire application run« less
A hybrid symbolic/finite-element algorithm for solving nonlinear optimal control problems
NASA Technical Reports Server (NTRS)
Bless, Robert R.; Hodges, Dewey H.
1991-01-01
The general code described is capable of solving difficult nonlinear optimal control problems by using finite elements and a symbolic manipulator. Quick and accurate solutions are obtained with a minimum for user interaction. Since no user programming is required for most problems, there are tremendous savings to be gained in terms of time and money.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Murray, P.F.
1986-03-01
The Monsanto Chocolate Bayou plant has had an aggressive and successful energy conservation program. The combined efforts have resulted in a 80% reduction in unit energy consumption compared to 1972. The approach of using system audits to optimize fluid systems was developed. Since most of the fluid movers are centrifugal, the name Centrifugal Savings Task Force was adopted. There are three tools that are particularly valuable in optimizing fluid systems. First, a working level understanding of the Affinity Laws seems a must. In addition, the performance curves for the fluid movers is needed. The last need is accurate system fieldmore » data. Systems effectively managed at the Chocolate Bayou plant were process air improvement, feed-water pressure reduction, combustion air blower turbine speed control, and cooling tower pressure reduction. Optimization of centrifugal systems is an often-overlooked opportunity for energy savings. The basic guidelines are to move only the fluid needed, and move it at as low a pressure as possible.« less
A multi-criteria evaluation of high efficiency clothes dryers: Gas and electric
DOE Office of Scientific and Technical Information (OSTI.GOV)
deMonsabert, S.; LaFrance, P.M.
1999-11-01
The results of an in-depth analysis to address the possible solutions to save energy and mitigate environmental damage caused by clothes dryers are presented in this paper. The analysis includes an environmental evaluation of gas and electric dryers. Various dryer technologies such as microwave, heat pump, heat recovery, and other designs are analyzed. Highly efficient clothes washers with increased moisture extraction that may reduce dryer impacts are also included within the analysis. The analysis includes the development of a multi-objective decision model that is solved for the short- and long-term to provide optimal courses of action. The results of themore » analysis revealed that fuel switching from electricity to natural gas was the optimal short-term solution. This measure could save a projected 2.5 MMT of carbon emissions annually by the year 2010. The optimal long-term alternative was not clear. The results showed that the option to research and develop a new high efficiency dryer was marginally better than fuel switching.« less
Solar energy system economic evaluation for IBM System 3, Glendo, Wyoming
NASA Technical Reports Server (NTRS)
1980-01-01
This analysis was based on the technical and economic models in f-chart design procedures with inputs based on the characteristics of the parameters of present worth of system cost over a projected twenty year life: life cycle savings, year of positive savings, and year of payback for the optimized solar energy system at each of the analysis sites. The sensitivity of the economic evaluation to uncertainties in constituent system and economic variables was also investigated.
USAF Logistics Process Optimization Study for the Aircraft Asset Sustainment Process. Volume 1.
1998-12-31
solely to have a record that could be matched with the CMOS receipt data. (This problem is caused by DLA systems that currently do not populate CMOS with...unable to obtain passwords to the Depot D035 systems. Figure 16 shows daily savings as of 30 September 1998 (current time frame ) and projects savings...Engineering, modeling, and systems/software development company LAN Local Area Network LFA Large Frame Aircraft LMA Logistics Management Agency LMR
An energy saving mechanism of EPON networks for real time video transmission
NASA Astrophysics Data System (ADS)
Liu, Chien-Ping; Wu, Ho-Ting; Chiang, Yun-Ting; Chien, Shieh-Chieh; Ke, Kai-Wei
2015-07-01
Modern access networks are constructed widely by passive optical networks (PONs) to meet the growing bandwidth demand. However, higher bandwidth means more energy consumption. To save energy, a few research works propose the dual-mode energy saving mechanism that allows the ONU to operate between active and sleep modes periodically. However, such dual-mode energy saving design may induce unnecessary power consumption or packet delay increase in the case where only downstream data exist for most of the time. In this paper, we propose a new tri-mode energy saving scheme for Ethernet PON (EPON). The new tri-mode energy saving design, combining the dual-mode saving mechanism with the doze mode, allows the ONU to switch among these three modes alternatively. In the doze mode, the ONU may receive downstream data while keeping its transmitter close. Such scenario is often observed for real time video downstream transmission. Furthermore, the low packet delay of high priority upstream data can be attained through the use of early wake-up mechanism employed in both energy saving modes. The energy saving and system efficiency can thus be achieved jointly while maintaining the differentiated QoS for data with various priorities. Performance results via simulation have demonstrated the effectiveness of such mechanism.
Uncooled detectors optimized for unattended applications
NASA Astrophysics Data System (ADS)
Malkinson, E.; Fraenkel, A.; Mizrahi, U.; Ben-Ezra, M.; Bikov, L.; Adin, A.; Zabar, Y.; Seter, D.; Kopolovich, Z.
2005-10-01
SCD has recently presented an uncooled detector product line based on the high-end VOx bolometer technology. The first FPA launched, named BIRD - short for Bolometer Infra Red Detector, is a 384x288 (or 320x240) configurable format with 25μm pitch. Typical NETD values for these FPAs range at 50mK with an F/1 aperture and 60 Hz frame rate. These detectors also exhibit a relatively fast thermal time constant of approximately 10 msec, as reported previously. In this paper, the special features of BIRD optimized for unattended sensor applications are presented and discussed. Unattended surveillance using sensors on unattended aerial vehicles (UAV's) or micro air vehicles (MAV's) , unattended ground vehicles (UGV's) or unattended ground sensor (UGS) are growing applications for uncooled detectors. This is due to their low power consumption, low weight, negligible acoustic noise and reduced price. On the other hand, uncooled detectors are vulnerable to ambient drift. Even minor temperature fluctuations are manifested as fixed pattern noise (FPN). As a result, frequent, shutter operation must be applied, with the risk of blocking the scenery in critical time frames and loosing information for various scenarios. In order to increase the time span between shutter operations, SCD has incorporated various features within the FPA and supporting algorithms. This paper will discuss these features and present some illustrative examples. Minimum power consumption is another critical issue for unattended applications. SCD has addressed this topic by introducing the "Power Save" concept. For very low power applications or for TEC-less (Thermo-Electric-Cooler) applications, the flexible dilution architecture enables the system to operate the detector at a number of formats. This, together with a smooth frame rate and format transition capability turns SCD's uncooled detector to be well suited for unattended applications. These issues will be described in detail as well.
Optimizing Storage and Renewable Energy Systems with REopt
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elgqvist, Emma M.; Anderson, Katherine H.; Cutler, Dylan S.
Under the right conditions, behind the meter (BTM) storage combined with renewable energy (RE) technologies can provide both cost savings and resiliency. Storage economics depend not only on technology costs and avoided utility rates, but also on how the technology is operated. REopt, a model developed at NREL, can be used to determine the optimal size and dispatch strategy for BTM or off-grid applications. This poster gives an overview of three applications of REopt: Optimizing BTM Storage and RE to Extend Probability of Surviving Outage, Optimizing Off-Grid Energy System Operation, and Optimizing Residential BTM Solar 'Plus'.
Helicopter Control Energy Reduction Using Moving Horizontal Tail
Oktay, Tugrul; Sal, Firat
2015-01-01
Helicopter moving horizontal tail (i.e., MHT) strategy is applied in order to save helicopter flight control system (i.e., FCS) energy. For this intention complex, physics-based, control-oriented nonlinear helicopter models are used. Equations of MHT are integrated into these models and they are together linearized around straight level flight condition. A specific variance constrained control strategy, namely, output variance constrained Control (i.e., OVC) is utilized for helicopter FCS. Control energy savings due to this MHT idea with respect to a conventional helicopter are calculated. Parameters of helicopter FCS and dimensions of MHT are simultaneously optimized using a stochastic optimization method, namely, simultaneous perturbation stochastic approximation (i.e., SPSA). In order to observe improvement in behaviors of classical controls closed loop analyses are done. PMID:26180841
Identification of cost effective energy conservation measures
NASA Technical Reports Server (NTRS)
Bierenbaum, H. S.; Boggs, W. H.
1978-01-01
In addition to a successful program of readily implemented conservation actions for reducing building energy consumption at Kennedy Space Center, recent detailed analyses have identified further substantial savings for buildings representative of technical facilities designed when energy costs were low. The techniques employed for determination of these energy savings consisted of facility configuration analysis, power and lighting measurements, detailed computer simulations and simulation verifications. Use of these methods resulted in identification of projected energy savings as large as $330,000 a year (approximately two year break-even period) in a single building. Application of these techniques to other commercial buildings is discussed
Feasibility and Design Implications of Fuel Cell Power for Sealift Ships
2010-01-01
Feasibility and Design Implications of Fuel Cell Power for Sealift Ships Jing Suna, John Stebeb, and Colen Kennellb a Department of Naval...studies published so far have focused on ship service power or on propulsion power for small vessels with moderate power requirements. Using a ... a large military cargo ship. A notional solid oxide fuel cell (SOFC) module is proposed and the implications of the technology on fuel savings and
NASA Technical Reports Server (NTRS)
Bochem, J. H.; Mossman, D. C.; Lanier, P. D.
1977-01-01
The feasibility of incorporating optimal concepts into a practical system was determined. Various earlier theoretical analyses were confirmed, and insight was gained into the sensitivity of fuel conservation strategies to nonlinear and second order aerodynamic and engine characteristics. In addition to the investigation of optimal trajectories the study ascertained combined fuel savings by utilizing various procedure-oriented improvements such as delayed flap/decelerating approaches and great circle navigation.
Yabalak, Erdal
2018-05-18
This study was performed to investigate the mineralization of ticarcillin in the artificially prepared aqueous solution presenting ticarcillin contaminated waters, which constitute a serious problem for human health. 81.99% of total organic carbon removal, 79.65% of chemical oxygen demand removal, and 94.35% of ticarcillin removal were achieved by using eco-friendly, time-saving, powerful and easy-applying, subcritical water oxidation method in the presence of a safe-to-use oxidizing agent, hydrogen peroxide. Central composite design, which belongs to the response surface methodology, was applied to design the degradation experiments, to optimize the methods, to evaluate the effects of the system variables, namely, temperature, hydrogen peroxide concentration, and treatment time, on the responses. In addition, theoretical equations were proposed in each removal processes. ANOVA tests were utilized to evaluate the reliability of the performed models. F values of 245.79, 88.74, and 48.22 were found for total organic carbon removal, chemical oxygen demand removal, and ticarcillin removal, respectively. Moreover, artificial neural network modeling was applied to estimate the response in each case and its prediction and optimizing performance was statistically examined and compared to the performance of central composite design.
Zhu, Yuanheng; Zhao, Dongbin; Li, Xiangjun
2017-03-01
H ∞ control is a powerful method to solve the disturbance attenuation problems that occur in some control systems. The design of such controllers relies on solving the zero-sum game (ZSG). But in practical applications, the exact dynamics is mostly unknown. Identification of dynamics also produces errors that are detrimental to the control performance. To overcome this problem, an iterative adaptive dynamic programming algorithm is proposed in this paper to solve the continuous-time, unknown nonlinear ZSG with only online data. A model-free approach to the Hamilton-Jacobi-Isaacs equation is developed based on the policy iteration method. Control and disturbance policies and value are approximated by neural networks (NNs) under the critic-actor-disturber structure. The NN weights are solved by the least-squares method. According to the theoretical analysis, our algorithm is equivalent to a Gauss-Newton method solving an optimization problem, and it converges uniformly to the optimal solution. The online data can also be used repeatedly, which is highly efficient. Simulation results demonstrate its feasibility to solve the unknown nonlinear ZSG. When compared with other algorithms, it saves a significant amount of online measurement time.
A two-hop based adaptive routing protocol for real-time wireless sensor networks.
Rachamalla, Sandhya; Kancherla, Anitha Sheela
2016-01-01
One of the most important and challenging issues in wireless sensor networks (WSNs) is to optimally manage the limited energy of nodes without degrading the routing efficiency. In this paper, we propose an energy-efficient adaptive routing mechanism for WSNs, which saves energy of nodes by removing the much delayed packets without degrading the real-time performance of the used routing protocol. It uses the adaptive transmission power algorithm which is based on the attenuation of the wireless link to improve the energy efficiency. The proposed routing mechanism can be associated with any geographic routing protocol and its performance is evaluated by integrating with the well known two-hop based real-time routing protocol, PATH and the resulting protocol is energy-efficient adaptive routing protocol (EE-ARP). The EE-ARP performs well in terms of energy consumption, deadline miss ratio, packet drop and end-to-end delay.
NASA Astrophysics Data System (ADS)
Abeywickrama, Sandu; Furdek, Marija; Monti, Paolo; Wosinska, Lena; Wong, Elaine
2016-12-01
Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.
NASA Technical Reports Server (NTRS)
Mudgett, Paul D.; Schultz, John R.; Sauer, Richard L.
1992-01-01
Until 1989, ion chromatography (IC) was the baseline technology selected for the Specific Ion Analyzer, an in-flight inorganic water quality monitor being designed for Space Station Freedom. Recent developments in capillary electrophoresis (CE) may offer significant savings of consumables, power consumption, and weight/volume allocation, relative to IC technology. A thorough evaluation of CE's analytical capability, however, is necessary before one of the two techniques is chosen. Unfortunately, analytical methods currently available for inorganic CE are unproven for NASA's target list of anions and cations. Thus, CE electrolyte chemistry and methods to measure the target contaminants must be first identified and optimized. This paper reports the status of a study to evaluate CE's capability with regard to inorganic and carboxylate anions, alkali and alkaline earth cations, and transition metal cations. Preliminary results indicate that CE has an impressive selectivity and trace sensitivity, although considerable methods development remains to be performed.
T-L Plane Abstraction-Based Energy-Efficient Real-Time Scheduling for Multi-Core Wireless Sensors.
Kim, Youngmin; Lee, Ki-Seong; Pham, Ngoc-Son; Lee, Sun-Ro; Lee, Chan-Gun
2016-07-08
Energy efficiency is considered as a critical requirement for wireless sensor networks. As more wireless sensor nodes are equipped with multi-cores, there are emerging needs for energy-efficient real-time scheduling algorithms. The T-L plane-based scheme is known to be an optimal global scheduling technique for periodic real-time tasks on multi-cores. Unfortunately, there has been a scarcity of studies on extending T-L plane-based scheduling algorithms to exploit energy-saving techniques. In this paper, we propose a new T-L plane-based algorithm enabling energy-efficient real-time scheduling on multi-core sensor nodes with dynamic power management (DPM). Our approach addresses the overhead of processor mode transitions and reduces fragmentations of the idle time, which are inherent in T-L plane-based algorithms. Our experimental results show the effectiveness of the proposed algorithm compared to other energy-aware scheduling methods on T-L plane abstraction.
Game Theory for Wireless Sensor Networks: A Survey
Shi, Hai-Yan; Wang, Wan-Liang; Kwok, Ngai-Ming; Chen, Sheng-Yong
2012-01-01
Game theory (GT) is a mathematical method that describes the phenomenon of conflict and cooperation between intelligent rational decision-makers. In particular, the theory has been proven very useful in the design of wireless sensor networks (WSNs). This article surveys the recent developments and findings of GT, its applications in WSNs, and provides the community a general view of this vibrant research area. We first introduce the typical formulation of GT in the WSN application domain. The roles of GT are described that include routing protocol design, topology control, power control and energy saving, packet forwarding, data collection, spectrum allocation, bandwidth allocation, quality of service control, coverage optimization, WSN security, and other sensor management tasks. Then, three variations of game theory are described, namely, the cooperative, non-cooperative, and repeated schemes. Finally, existing problems and future trends are identified for researchers and engineers in the field. PMID:23012533
CFD Aided Design and Production of Hydraulic Turbines
NASA Astrophysics Data System (ADS)
Kaplan, Alper; Cetinturk, Huseyin; Demirel, Gizem; Ayli, Ece; Celebioglu, Kutay; Aradag, Selin; ETU Hydro Research Center Team
2014-11-01
Hydraulic turbines are turbo machines which produce electricity from hydraulic energy. Francis type turbines are the most common one in use today. The design of these turbines requires high engineering effort since each turbine is tailor made due to different head and discharge. Therefore each component of the turbine is designed specifically. During the last decades, Computational Fluid Dynamics (CFD) has become very useful tool to predict hydraulic machinery performance and save time and money for designers. This paper describes a design methodology to optimize a Francis turbine by integrating theoretical and experimental fundamentals of hydraulic machines and commercial CFD codes. Specific turbines are designed and manufactured with the help of a collaborative CFD/CAD/CAM methodology based on computational fluid dynamics and five-axis machining for hydraulic electric power plants. The details are presented in this study. This study is financially supported by Turkish Ministry of Development.
Energy modelling in sensor networks
NASA Astrophysics Data System (ADS)
Schmidt, D.; Krämer, M.; Kuhn, T.; Wehn, N.
2007-06-01
Wireless sensor networks are one of the key enabling technologies for the vision of ambient intelligence. Energy resources for sensor nodes are very scarce. A key challenge is the design of energy efficient communication protocols. Models of the energy consumption are needed to accurately simulate the efficiency of a protocol or application design, and can also be used for automatic energy optimizations in a model driven design process. We propose a novel methodology to create models for sensor nodes based on few simple measurements. In a case study the methodology was used to create models for MICAz nodes. The models were integrated in a simulation environment as well as in a SDL runtime framework of a model driven design process. Measurements on a test application that was created automatically from an SDL specification showed an 80% reduction in energy consumption compared to an implementation without power saving strategies.
GPU accelerated implementation of NCI calculations using promolecular density.
Rubez, Gaëtan; Etancelin, Jean-Matthieu; Vigouroux, Xavier; Krajecki, Michael; Boisson, Jean-Charles; Hénon, Eric
2017-05-30
The NCI approach is a modern tool to reveal chemical noncovalent interactions. It is particularly attractive to describe ligand-protein binding. A custom implementation for NCI using promolecular density is presented. It is designed to leverage the computational power of NVIDIA graphics processing unit (GPU) accelerators through the CUDA programming model. The code performances of three versions are examined on a test set of 144 systems. NCI calculations are particularly well suited to the GPU architecture, which reduces drastically the computational time. On a single compute node, the dual-GPU version leads to a 39-fold improvement for the biggest instance compared to the optimal OpenMP parallel run (C code, icc compiler) with 16 CPU cores. Energy consumption measurements carried out on both CPU and GPU NCI tests show that the GPU approach provides substantial energy savings. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Aerodynamics of a cycling team in a time trial: does the cyclist at the front benefit?
NASA Astrophysics Data System (ADS)
Íñiguez-de-la Torre, A.; Íñiguez, J.
2009-11-01
When seasonal journeys take place in nature, birds and fishes migrate in groups. This provides them not only with security but also a considerable saving of energy. The power they need to travel requires overcoming aerodynamic or hydrodynamic drag forces, which can be substantially reduced when the group travels in an optimal arrangement. Also in this area, humans imitate nature, which is especially evident in the practice of outdoor sports and motor competitions. Cycle races, in which speeds of up to 15 m s-1 are frequent, offer great opportunities to appreciate the advantage of travelling in a group. Here we present a brief analysis of the aerodynamics of a cycling team in a time-trial challenge, showing how each rider is favoured according to his position in the group. We conclude that the artificial tail wind created by the team also benefits the cyclist at the front by about 5%.
Chattanooga Electric Power Board Case Study Distribution Automation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Glass, Jim; Melin, Alexander M.; Starke, Michael R.
In 2009, the U.S. Department of Energy under the American Recovery and Reinvestment Act (ARRA) awarded a grant to the Chattanooga, Tennessee, Electric Power Board (EPB) as part of the Smart Grid Investment Grant Program. The grant had the objective “to accelerate the transformation of the nation’s electric grid by deploying smart grid technologies.” This funding award enabled EPB to expedite the original smart grid implementation schedule from an estimated 10-12 years to 2.5 years. With this funding, EPB invested heavily in distribution automation technologies including installing over 1,200 automated circuit switches and sensors on 171 circuits. For utilities consideringmore » a commitment to distribution automation, there are underlying questions such as the following: “What is the value?” and “What are the costs?” This case study attempts to answer these questions. The primary benefit of distribution automation is increased reliability or reduced power outage duration and frequency. Power outages directly impact customer economics by interfering with business functions. In the past, this economic driver has been difficult to effectively evaluate. However, as this case study demonstrates, tools and analysis techniques are now available. In this case study, the impact on customer costs associated with power outages before and after the implementation of distribution automation are compared. Two example evaluations are performed to demonstrate the benefits: 1) a savings baseline for customers under normal operations1 and 2) customer savings for a single severe weather event. Cost calculations for customer power outages are performed using the US Department of Energy (DOE) Interruption Cost Estimate (ICE) calculator2. This tool uses standard metrics associated with outages and the customers to calculate cost impact. The analysis shows that EPB customers have seen significant reliability improvements from the implementation of distribution automation. Under normal operations, the investment in distribution automation has enabled a 43.5% reduction in annual outage minutes since 2012. This has led to an estimated total savings of $26.8 million per year. Examining a single severe weather event3, the distribution automation was able to restore power to 40,579 (nearly 56%) customers within 1–2 seconds and reduce outage minutes by 29.0%. This saved customers an estimated $23.2 million over the course of the storm.« less
Preparing aircraft propulsion for a new era in energy and the environment
NASA Technical Reports Server (NTRS)
Stewart, W. L.; Nored, D. L.; Grobman, J. S.; Feiler, C. E.; Petrash, D. A.
1980-01-01
Improving fuel efficiency, new sources of jet fuel, and noise and emission control are subjects of NASA's aeronautics program. Projects aimed at attaining a 5% fuel savings for existing engines and a 13-22% savings for the next generation of turbofan engines using advanced components, and establishing a basis for turboprop-powered commercial air transports with 30-40% savings over conventional turbofan aircraft at comparable speeds and altitudes, are discussed. Fuel sources are considered in terms of reduced hydrogen and higher aromatic contents and resultant higher liner temperatures, and attention is given to lean burning, improved fuel atomization, higher freezing-point fuel, and deriving jet fuel from shale oil or coal. Noise sources including the fan, turbine, combustion process, and flow over internal struts, and attenuation using acoustic treatment, are discussed, while near-term reduction of polluting gaseous emissions at both low and high power, and far-term defining of the minimum gaseous-pollutant levels possible from turbine engines are also under study.