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Wyszukujesz frazę "efficiency" wg kryterium: Temat


Tytuł:
Improved Water-Filling Power Allocation for Energy-Efficient Massive MIMO Downlink Transmissions
Autorzy:
Noor Shahida, M. K.
Nordin, R.
Insmail, M.
Powiązania:
https://bibliotekanauki.pl/articles/227000.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
energy efficiency
Massive MIMO
power allocation
spectral efficiency
Opis:
Energy Efficiency (EE) is becoming increasingly important for wireless communications and has caught more attention due to steadily rising energy costs and environmental concerns. Recently, a new network architecture known as Massive Multiple-Input Multiple-Output (MIMO) has been proposed with the remarkable potential to achieve huge gains in EE with simple linear processing. In this paper, a power allocation algorithm is proposed for EE to achieve the optimal EE in Massive MIMO. Based on the simplified expression, we develop a new algorithm to compute the optimal power allocation algorithm and it has been compared with the existing scheme from the previous literature. An improved water filling algorithm is proposed and embedded in the power allocation algorithm to maximize EE and Spectral Efficiency (SE). The numerical analysis of the simulation results indicates an improvement of 40% in EE and 50% in SE at the downlink transmission, compared to the other existing schemes. Furthermore, the results revealed that SE does not influence the EE enhancement after using the proposed algorithm as the number of Massive MIMO antenna at the Base Station (BS) increases.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 1; 79-84
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy efficiency – selected thermo-ecological problems
Autorzy:
Ziębik, Andrzej
Stanek, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/239928.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
energy efficiency
system analysis
exergy
thermo-ecology
energy ecological
efficiency
Opis:
The paper is devoted to some problems connected with last modification of EU directive on energy efficiency, viz.: free choice of the measure concerning the improvement of energy efficiency, i.e. final or primary energy consumption, corresponding energy savings or energy-consumption index; however without cumulative consumption or cumulative savings of primary energy. In EU directive it has been stressed the importance of measurements systems (reliable measurement information); but has not been recommended any advanced validation of measurements results, nor energy auditing or algorithms of calculating the energy savings due to improvement of energy efficiency concerning large industrial plants. Evaluation of complex buildings should be realized by means of the system method (input-output analysis). The separate problem is devoted to application of thermo-ecological approach in the analysis of complete results of improving the energy efficiency. Human activity is connected with the depletion of nonrenewable resources, including primary energy, due to not only production of consumer goods but also the necessity of compensating the unfavourable effects of harmful emissions from energy-technological processes. Therefore the index of energy-ecological efficiency has been proposed as the most competent evaluation of improvement energy efficiency of production processes and systems.
Źródło:
Archives of Thermodynamics; 2020, 41, 2; 277-299
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of the modified AGT method applied to determining efficiency of squirrel-cage induction motor
Autorzy:
Figura, R.
Szychta, L.
Kwiecień, R.
Powiązania:
https://bibliotekanauki.pl/articles/141240.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metoda AGT
sprawność silnika
szacowanie wydajności
AGT method
motor efficiency
motor efficiency testing
efficiency estimating
Opis:
The modified air gap torque method to determine the efficiency of squirrelcage induction motor was presented. of testing which continues the authors' work on application of AGT method to estimating induction motor's efficiency are discussed. The proposed method is verified in a number of selected low-power motors.
Źródło:
Archives of Electrical Engineering; 2012, 61, 3; 315-323
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Throughput, Spectral, and Energy Efficiency of 5G Massive MIMO Applications Using Different Linear Precoding Schemes
Autorzy:
Salah, Ibrahim
Rahouma, Kamel Hussein
Hussein, Aziza I.
Mabrook, M. Mourad
Powiązania:
https://bibliotekanauki.pl/articles/2203002.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
throughput
massive MIMO
spectral efficiency
energy efficiency
trade-off
Opis:
On fifth-generation wireless networks, a potential massive MIMO system is used to meet the ever-increasing request for high-traffic data rates, high-resolution streaming media, and cognitive communication. In order to boost the trade-off between energy efficiency (EE), spectral efficiency (SE), and throughput in wireless 5G networks, massive MIMO systems are essential. This paper proposes a strategy for EE 5G optimization utilizing massive MIMO technology. The massive MIMO system architecture would enhance the trade-off between throughput and EE at the optimum number of working antennas. Moreover, the EE-SE tradeoff is adjusted for downlink and uplink massive MIMO systems employing linear precoding techniques such as Multiple -Minimum Mean Square Error (M-MMSE), Regularized Zero Forcing (RZF), Zero Forcing (ZF), and Maximum Ratio (MR). Throughput is increased by adding more antennas at the optimum EE, according to the analysis of simulation findings. Next, utilizing M MMSE instead of RZF and ZF, the suggested trading strategy is enhanced and optimized. The results indicate that M-MMSE provides the best tradeoff between EE and throughput at the determined optimal ratio between active antennas and active users equipment’s (UE).
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 1; 185--191
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cooling water flow influence on power plant unit performance for various condenser configurations setup
Autorzy:
Dobkiewicz-Wieczorek, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/2091367.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cooling water
power plant efficiency
cooling water flow control
CHP plant
efficiency
Opis:
This paper presents the influence of cooling water regulation on power plant net efficiency. It was examined whether, for the non-nominal low-pressure turbine load, it is justified to reduce the cooling water pump load, and how it would affect the unit net efficiency. Calculations for two types of power units were carried out: with condensing and extraction-condensing turbine. The tested condensing power plant consists of three surface condensers. The calculation included four condensers’ connections set up on the cooling water side to check how the cooling water system pressure drop affects the net unit performance. The result has confirmed that implementing serial connection decreases net efficiency when cooling water flow regulation is used, but the mixed connection should be applied when pump load is not controlled. It was proved that the cooling water flow control gives a profit for both units. Net efficiency for combined heat and power plant can be improved by 0.1–0.5 pp, the gain is remarkable below 60% of the low-pressure turbine part load. Flow control implementation in the unit with condensing turbine water control gives a similar profit just below 80% of the turbine load. Next, an influence of the additional limitations of a cooling water system (minimal total pump head, cooling tower) affecting the feasibility of implementing the water control has been considered. Applying a multi-cell forced draft cooling tower does not have a significant impact on results, but when a natural draft cooling tower is used, the flow control range is strongly reduced.
Źródło:
Archives of Thermodynamics; 2022, 43, 1; 141--167
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decision-making model for supporting supply chain efficiency evaluation
Autorzy:
Jacyna-Gołda, I.
Powiązania:
https://bibliotekanauki.pl/articles/224288.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
decision-making model
assessing the efficiency
supply chain efficiency
efficiency
model decyzyjny
ocena efektywności
łańcuch dostaw
efektywność
wskaźniki oceny
Opis:
This paper presents some approach for the formulation of the decision-making model in supporting the assessment of supply chain efficiency. Were presented factors affecting the efficiency of the functioning of individual links of supply chain. Was pointed out the technical, economic, organizational and reliability aspects affecting the efficiency and reliability of functioning of the supply chain both in terms of supply and distribution. Having regard to a comprehensive approach to assessing efficiency of the functioning of supply chains were proposed indicators for assessing the quality of functioning. Were distinguished technical, economic and quality indicators for which also were presented a formal record.
Źródło:
Archives of Transport; 2015, 33, 1; 17-31
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The methodology of the gas turbine efficiency calculation
Autorzy:
Kotowicz, J.
Job, M.
Brzęczek, M.
Nawrat, K.
Mędrych, J.
Powiązania:
https://bibliotekanauki.pl/articles/240275.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas turbine
polytropic efficiency
isentropic efficiency
turbina gazowa
efektywność politropowa
obiekt chłodniczy
Opis:
In the paper a calculation methodology of isentropic efficiency of a compressor and turbine in a gas turbine installation on the basis of polytropic efficiency characteristics is presented. A gas turbine model is developed into software for power plant simulation. There are shown the calculation algorithms based on iterative model for isentropic efficiency of the compressor and for isentropic efficiency of the turbine based on the turbine inlet temperature. The isentropic efficiency characteristics of the compressor and the turbine are developed by means of the above mentioned algorithms. The gas turbine development for the high compressor ratios was the main driving force for this analysis. The obtained gas turbine electric efficiency characteristics show that an increase of pressure ratio above 50 is not justified due to the slight increase in the efficiency with a significant increase of turbine inlet combustor outlet and temperature.
Źródło:
Archives of Thermodynamics; 2016, 37, 4; 19-35
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of a combined cycle power plant located in Jordan: A case study
Autorzy:
Bataineh, Khaled
Khaleel, Bara A.
Powiązania:
https://bibliotekanauki.pl/articles/240565.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
combined cycle power plant
energy efficiency
exergy efficiency
exergy destruction
exergy losses
Opis:
Efficiency and electrical power output of combined cycle power plants vary according to the ambient conditions. The amount of these variations greatly affects electricity production, fuel consumption, and plant incomes. Obviously, many world countries have a wide range of climatic conditions, which impact the performance of power plants. In this paper, a thermodynamic analysis of an operating power plant located in Jordan is performed with actual operating data acquired from the power plant control unit. The analysis is performed by using first and second laws of thermodynamics. Energy and exergy efficiencies of each component of the power plant system are calculated and the effect of ambient temperature on the components performance is studied. The effects of gas turbine pressure ratio, gas turbine inlet temperature, load and ambient conditions on the combined cycle efficiency, power outputs and exergy destruction are investigated. Energy and exergy efficiencies of the combined cycle power plant are found as 45.29%, and 42.73% respectively when the ambient temperature is 34°C. Furthermore, it is found that the combustion chamber has the largest exergy destruction rate among the system components. The results showed that 73% of the total exergy destruction occurs in the combustion chamber when the ambient temperature is 34°C. Moreover, the results show that the second major exergy loss is in HRSC. The results show that the energy and exergy efficiency of the combined cycle power plant decreases as the ambient temperature increases. According to the calculation results, improvement and modification suggestions are presented.
Źródło:
Archives of Thermodynamics; 2020, 41, 1; 95-123
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Human factors in visual quality control
Autorzy:
Kujawińska, A.
Vogt, K.
Powiązania:
https://bibliotekanauki.pl/articles/407375.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
production
process efficiency
visual inspection
Opis:
Visual control (visual inspection) is often used in production because - in comparison to other kinds of control - it is relatively easy to conduct. It does not require any specialized technical equipment. Human senses, usually sight, are the measurement tool. Unfortunately, visual control does not guarantee a fully correct assessment. The reason is the limited human reliability. There are plenty of factors which influence ability of a human to assess the process or product quality properly. An important group of them are ergonomic factors. The goal of the paper is to identify and discuss their influence on the efficiency of the visual quality control in manufacturing processes. The research was carried out in manufacturing company from automotive industry. The paper presents the investigation of work organizational factors influence on visual control effectiveness. A controller can make two types of errors in the process of visual inspection: to assess a conforming product as “defective” or to assess a non-conforming product as “good”. Effectiveness of sequential visual controls in selected process was examined. As a measure of visual control effectiveness Control First Pass Yield index was defended. Three operations were analyzed: assembly of components, melting components and applying a protective coating.
Źródło:
Management and Production Engineering Review; 2015, 6, 2; 25-31
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Energy-Efficient Proactive Routing Scheme for MANET : Game Theoretical Approach of Forwarding with Selfish Nodes
Autorzy:
Sahnoun, A.
Habbani, A.
El Abbadi, J.
Powiązania:
https://bibliotekanauki.pl/articles/963872.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
game theory
MANETs
energy efficiency
Opis:
In Mobile Ad-hoc Networks, nodes exchange packets with each other using intermediate nodes as relays. Since nodes in MANETs are battery powered, energy conservation is a crucial issue. Accepting relay all request may not be in the best interest of a node. But if many nodes prefer not to consume energy in relaying packets on behalf of others, the overall performance of routing in network will be influenced. In this paper we address the energyefficient routing problem in MANETs with selfish nodes. We modeled this problem as a game-theoretic constraint optimization; we defined the utility of each node as a weighted difference between a performance metric and some transmission costs. A motivate mechanism is proposed in order to induce nodes to forwarding cooperation. Each node independently implements the optimal equilibrium strategy under the given constraints. Simulation results by NS3 simulator show that our proposed approach can improve system performance in network lifetime and packet delivery ratio.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 4; 399-404
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of DVB-S2 Standard Using Signal-Code Constructions Based on Amplitude Modulation of Many Components
Autorzy:
Horbatyi, Ivan
Yashchyshyn, Yevhen
Powiązania:
https://bibliotekanauki.pl/articles/227156.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DVB-S2 standard
frequency efficiency
energy efficiency
amplitude modulation of many components
Opis:
It is proposed to modernize the DVB-S2 standard by using AMMC (amplitude modulation of many components) signals instead of 8PSK (8-phase shift keying) and APSK (amplitude-phase shift keying) signals, and to modernize the DVB-S2 standard equipment by using the AMMC modulator and AMMC demodulator. Usage of AMMC makes it possible to reduce the symbol error rate in communication channel up to 52 times. The satellite digital video broadcast systems that apply signal-code constructions based on AMMC are characterized by a higher energy efficiency from 1 to 2.6 dB compared with signal-code constructions based on 8PSK and APSK.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 315-320
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficiency of the Reversed First-Price Sealed Bid Auctions with a Dynamic Run-Off. Results of Experiments
Autorzy:
Kuśmierczyk, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2076531.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
auction
procurement auction
efficiency
experiments
Opis:
In case of the private procurement auctions the entrepreneurs are not forced to limit themselves to the standard auction rules, and in practice one can observe many hybrid or quasi-auction mechanisms spontaneously introduced. The paper analyzes two of them, which start as a first-price sealed-bid auction, followed by a run-off in a form of an English auction, and which differ by the transparency of rules concerning the initiation of the second stage. The focus of the paper is on the analysis of the price and allocative efficiency of these mechanisms, in order to determine whether they can serve as an alternative to the standard auction rules. Theoretical analyses are followed by the laboratory experiments, which demonstrate that the mechanisms under study are characterized by both high price and allocative efficiency, and therefore could be considered an interesting substitute of the standard auction rules.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2015, 3; 151-167
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy based analysis of solar air heater duct with W-shaped rib roughness on the absorber plate
Autorzy:
Patel, Sumer Singh
Lanjewar, Atul
Powiązania:
https://bibliotekanauki.pl/articles/240081.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solar air heater
W-shape rib
exergetic efficiency
Reynolds number
thermal efficiency
temperature rise parameter
Opis:
Exergy analysis is a powerful thermodynamic tool and it helps in computing the actual output of a system. It helps the researchers to optimize the roughened solar air heater design to compensate the present and also the future needs. In this study, investigation on exergetic performance evaluation of a solar air heater with W-shaped roughened absorber surface analytically by employing mathematical model and the results obtained are compared with smooth plate solar air heater under same operating conditions. The exergetic efficiency curves has been plotted as a function of different values of Reynolds number and temperature rise parameter for different roughness parameters. The maximum augmentation in the exergetic efficiency of the solar air heater with W-shaped roughened surface as compared to solar air heater with smooth surface has been obtained as 51% corresponding to the relative roughness height of 0.03375 and the rib angle of attack about 60°. Based on the exergetic efficiency the suitable design parameters of solar air heater with W-shaped roughened are determined.
Źródło:
Archives of Thermodynamics; 2019, 40, 4; 21-48
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards to efficiency maximum within a pressure increasing process
Autorzy:
Puzyrewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/175336.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
efficiency
kinematic flow
pumps
incompressible fluid
Opis:
The article presents a mathematical description of compression process in a pump and an original concept to increase efficiency in this process.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2014, 126; 153-168
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy efficiency of a biofuel production system
Autorzy:
Wasiak, A.
Orynycz, O.
Powiązania:
https://bibliotekanauki.pl/articles/406826.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
energy efficiency
EROEI
biofuels
production systems
Opis:
Manufacturing engineering is supposed to provide analyses related to various aspects of manufacturing and production in order to maximise technological, energy, and economic gains in relevant production processes. The present paper gives a recapitulation of several publications by present authors, presenting considerations of the energy efficiency of biofuel production. The energy efficiency is understood as the ratio of energy obtained from biofuels produced basing on crops from a particular area to the energy required to satisfy needs of all subsidiary processes assuring correct functioning of the production system, starting from operations aimed to obtain agricultural crops, and ending with the conversion of the crops onto biofuels. Derived by the present authors, the mathematical model of energy efficiency of biofuel production is extended to a more general form, and applied to the analysis of quantitative relations between energy efficiency of sc. “energy plantations”, and further elements of biofuel production system converting harvested biomass into biofuel. Investigations are aimed towards the determination of the role of biomass as a source of energy.
Źródło:
Management and Production Engineering Review; 2017, 8, 1; 60-68
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł

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