Efficiency Analysis Of Systems Research Articles

Efficiency analysis of induction heating systems with respect to electromagnetic shielding film's properties

Enhancing induction heating efficiency requires precise material selection and optimal structural design, including consideration of electromagnetic shielding materials. This study explores the impact of material properties on high-frequency resistance (Rs), inductance (Ls), and energy consumption. Metal powder-filled composites and ferrites typically exhibit lower relative permeability (μr) compared to nanocrystals, with an increase in μr leading to enhanced Ls, Rs, and heating efficiency. However, nanocrystalline shielding films show a unique trend where heating efficiency initially rises and then declines for multi-layered films, with a critical point at μr = 1500. Magnetic fragmentation induced imperfections in nanocrystalline films disrupt eddy current paths, reducing energy loss and improving heating efficiency as μr decreases. The notion of “relative conductivity (σ')” is introduced to demonstrate that a reduction in the fragmentation extent leads to the expansion of eddy current pathways as μr increases. This augmentation enhances both σ' and the imaginary permeability (μ''), leading to increased eddy current losses that affect overall efficiency. In evaluating energy efficiency for nanocrystals, it is crucial to consider μ', μ'', and σ' in conjunction, as there is a positive correlation between μ'' and σ'. Finite element analysis (FAE) confirms these observations, showing how film properties impact efficiency. Comprehending shielding mechanisms not only optimizes induction heating but also benefits applications such as wireless charging for electric vehicles and mobile communication devices.

Cost and Time Efficiency Analysis of Manual and e-Procurement Systems in Roads and Highways Department: Tender Advertising Issue Perspective

Public procurement is a vital process to procure goods, works and services, ensuring accountability that ensures cost and time-savings. Roads and Highways Departments (RHD) is a big department chosen as a target population for this study. All RHD Procurement Entities (PE) use manual and e-procurement tendering systems. However, cost and time reduction is a considerable barrier to RHD procurement. The manual tendering procedure is costly and time-consuming since it requires big-size tender advertisements in print media like daily papers. In RHD, however, no comparative analysis of the efficiency in the cost and time context of tender advertising has been explored. Therefore, using a stratified sampling method, the RHD's e-Procurement-related PE officers were chosen as a sample. The mean value of advertisement cost and time of the e-tender system and the manual tender system as a continuous normally distributed variable was utilized to compare two groups using the independent samples t-test model. The study's novel contribution is the comparison of efficiency in terms of cost and time context between two sets of manual and e-tender advertisements. According to the survey results, the e-procurement system showed lower cost and time involved in the tender advertising comparing manual tender. The results will also aid academicians and students and improvements to e-GP policy standards.

A unified methodology for the power efficiency analysis of physical systems

In this paper, the problem of power efficiency evaluation for n-ports physical systems is investigated. The efficiency analysis that we perform highlights the necessary and sufficient conditions for the system to be passive, and outlines the guidelines for the efficiency maps computation. After addressing the problem from a formal point of view, the analysis is deepened for the case of two-ports linear and nonlinear physical systems, and for the cases of three and four-ports linear systems. The efficiency analysis and the computation of the efficiency maps are addressed as a function of the power variables characterizing all the energetic ports of the considered systems. Furthermore, the salient properties of the efficiency are highlighted and discussed. The theoretical analysis which is developed is then applied to some physical systems of interest for industries and engineers working in the electromechanical, hydraulic and automotive fields: a DC electric motor driving an hydraulic pump for the two-ports systems class, a single-stage planetary gear set for the three-ports systems class, and a Ravigneaux planetary gear set for the four-ports systems class.

Spectrum-Energy-Economy Efficiency Analysis of B5G Wireless Communication Systems With Separated Indoor/Outdoor Scenarios

In this paper, we study the spectrum efficiency (SE), energy efficiency (EE), and economic efficiency (ECE) for a heterogeneous cellular architecture that separates the indoor and outdoor scenarios for beyond 5G (B5G) wireless communication systems. For outdoor scenarios, massive multiple-input-multiple-output (MIMO) technologies and distributed antenna systems (DASs) at sub-6 GHz frequency bands are used for long-distance communications. For indoor scenarios, millimeter-wave (mmWave) and beamforming communication technologies are deployed at wireless indoor access points (IAPs) to provide high-speed short-range services to indoor users. Mathematical expressions for the system capacity, SE, EE, and ECE are derived using a proposed realistic power consumption model. The results shed light on the fact that the proposed network architecture is able to improve SE and EE by more than three times compared to those conventional network architectures. The analysis of system performance in terms of SE, EE, ECE, and their trade-off results in the observation that the proposed network architecture offers a promising solution for future B5G communication systems.

Performance efficiency and cost analysis of multi-state systems with successive damage and maintenance in multiple shock events

Real-world systems are often exposed to shocks likes earthquakes and hurricanes during service life, and these shocks may occur multiple times. However, existing studies lack research on damage and maintenance interacting processes under multiple shocks. In this paper, a new performance efficiency and budget surplus rate model for multi-state systems is developed under the interaction of damage and maintenance. System performance efficiency measures the ability of the system to recover its performance from multiple shocks. The budget surplus rate model is introduced for measuring the system's ability to respond to losses from multiple shocks. Multiple cumulative shocks not only cause the system to transfer from a high-performance state to a low-performance state, but also accelerate the performance degradation of the system bringing successive damage, which is reflected by the reduced transition time between states. Markov processes are used to characterize the state transition process between the system suffering damage and maintenance under multiple shock events. A case study of a nuclear power plant is used to demonstrate the proposed methods. Sensitivity analysis of performance efficiency and budget surplus rate is also performed to reflect the shock resistance and maintenance capability of the nuclear power plant system.

Efficiency Analysis of Hydrogen Fuel Cell Power Systems for Off-Grid Applications

The escalating environmental hazards associated with the use of fossil fuels call for eco-friendly alternative renewable energy conversion sources. One of these renewable energy measures is the development of a hydrogen fuel cell, a device which directly converts the potential of chemical fuel into electrical power without combustion. This study evaluates the efficiency of a hydrogen fuel cell power system for off-grid applications with an aim to show how much energy can be generated from a locally produced hydrogen powered device, and for how long an electrical load (1Ω resistor) in the form of bulbs of varying loading sizes is carried. For the power and performance evaluation of the cell, multimeters equipped with integrated voltmeters and ammeters were employed for their accuracy, with a power generator, functioning through a rectifier, supplying a direct current of 3.45A at a known voltage of 18.2V, providing the means to calculate the energy input into the developed fuel cell. The results assessments, revealed that power levels steadily fall as time progresses, an occurrence caused by the depletion of reactants and the continuous accumulation of reaction products, which ultimately lead to decreasing electrochemical activity and subsequently decreased power generation. The graph readings show the dynamic behaviour of the fuel cell's performance depicted by the distinct pattern followed in the relationship between time and power output.

Design and Implementation of a Personalized Tourism Recommendation System Based on the Data Mining and Collaborative Filtering Algorithm.

A personalized tourism recommendation system provides convenient and economically affordable travel information for individuals/groups. This recommendation system banks on accumulated and analyzed data for providing context-aware travel solutions. For improving the recommendation efficiency and data analysis of such systems, this article introduces a mining and filtering harmonized collaborative process, named as the collaborative mining and filtering process (CMFP), for reducing the data processing overheads and improving the recommendation ratio. In this process, the accumulated data from the global and personal travel, expenditure, and other information are collaboratively analyzed. This analysis is powered by knowledge-based transfer learning for reducing the retardation in the large data processing. Based on the context-based data analysis, the filtering and mining are jointly performed for providing recommendations. In the filtering process, the maximum processed contextual data are extracted for updating the current knowledge base. From this base, the recommendation for adaptable travel is recommended for the user. This process's performance is analyzed using the metrics accuracy, data handling rate, mining time, and overhead.

Efficiency analysis of photovoltaic systems installed in different geographical locations

Abstract Many forms of energy are used in daily life. The most needed of these different forms is electricity. If this energy continues to be met with limited resources, it is clearly seen that sufficient energy needs will not be met in the future. Therefore, in the generation of electrical energy, existing resources must be used extremely efficiently. With the development of technology, electrical energy production is carried out more efficiently with non-renewable energy sources. These technological developments, which come to a certain point, can meet the demanded energy need up to a certain level. For this reason, many studies are carried out on renewable energy sources in order to respond to the needed energy demands. Therefore, in this study, the effect of geographical conditions on panel efficiency in electricity generation with solar panels, which is one of the renewable energy sources, was analyzed. Analyzes were carried out with power plant models installed in four different geographical regions of Turkey using the design and simulation software for photovoltaic systems program for PV systems. The effects of latitude, altitude and temperature on electrical energy production were investigated using the established power plant models.

Time and Cost Efficiency Analysis of Manual and e-Procurement Systems in Roads and Highways Department: TEC Meeting Arrangement Perspective

Public procurement ensures accountability, time, and cost savings in procuring goods, works, and services. All government departments use manual and electronic tendering processes to purchase goods and services. The Roads and Highways Department (RHD) is one of the big public departments designated as the study's target population. Manual and e-procurement tendering systems are used by all RHD procurement entities (PE). However, time and cost reduction are significant challenges in the manual tendering process. Because, it involves a lengthy process for Tender Evaluation Committee (TEC) meeting arrangements. However, no time and cost comparison study of the manual and e-GP tendering processes for TEC meeting arrangement has been done in RHD after e-procurement inception in 2011. This study uses a stratified sampling strategy to compare the time and cost of a manual tendering procedure to an e-tendering approach, targeting RHD PE officers as samples. The independent samples t-test model was used to compare two groups utilizing the mean value of TEC meeting arrangement time and cost of the e-tender system and the manual tender system as a continuous normally distributed variable. This study makes a unique contribution by comparing the time and cost efficiency of two sets of manual and e-tender procurement methods. The e-procurement system, according to the survey results, reduced excessive times and costs at TEC meeting arrangements. The findings will also be used to enhance academic research and to improve e-GP policy requirements.

Универсальный метод оценки вероятности лазерной индикации затопленных инженерных конструкций

Object and purpose of research. Laser diagnostics, analysis of reflected laser signal from fixed underwater objects, improvement of laser optical methods, technologies and tools for underwater object studies, development of laser detection systems, determination of laser indication probability for fixed underwater objects. Materials and methods. Laser detection systems, analytical and computational methods, software programs, analytical tools for measurement data processing, laser diagnostics of reflected laser signal from underwater objects taking into account dissipation and absorption in atmosphere and hydrosphere. Main results. Improvement of technology and methods for diagnostics of reflected laser signal (back-scattering), determination of reliable detection limits for laser signals reflected from fixed underwater objects, software programs, laser diagnostics, efficiency analysis of laser detection systems. Conclusion. The study showed that high efficiency of laser detection systems considerably depends on the selected tech- nology, reflected laser signal display and processing techniques, and also on the probabilistic methods adopted to estimate the reflected signal luminance and the knowledge of hydrodsphere parameters.

FLOCCULATION OF DISPERSE SYSTEMS BY POLYFUNCTIONAL POLYMER-INORGANIC HYBRIDS

Development of novel high-capacity multifunctional flocculants is a promising solution to selective separation of clay suspensions. Among such flocculants, polymer-inorganic hybrids are the most attractive for their excellent performance as compared with inorganic coagulants or syn-thetic polymers. Synthesis of polymer-inorganic hybrids was carried out in two stages. At the first stage, Al(OH)3sol was obtained by condensation of aluminum chloride and ammonium carbonate in the following conditions: t = 70°C, pH = 3-4, intensive stirring. In the second stage, Al(OH)3was mixed with aqueous solutions of polymers at room temperature. By changing the melting tem-perature of hybrid samples, the presence of interactionsbetween the Al3+cation and the carboxylate groups of the analyzed acrylamide copolymers were established. This paper reports synthesis and comparative efficiency analysis of systems that contain water-soluble anionic copolymers of acryla-mide and respective polyfunctional polymer-inorganic hybrids. We performed a quantitative char-acterization of concentration and structural effects of polymer flocculants on the flocculation mechanism and sludge thickening. Sludge thickening constants were determined. Higher values of thickening constants were noted in systems with additives of hybrid samples, due to the participa-tion of their macromolecules in the formation of floccules at the first stage of the sediment process, and at the stage of thickening of sediments,their deformation and compaction were revealed while maintaining a loose structure with the formation of bulk floccules. We considered the factors al-lowing to optimize flocculation of clay dispersions by polymer-inorganic hybrids in aqueous media. These novel flocculants were shown to have a good potential for applications in filtration or flota-tion processes as well as for wastewater treatment for removal of disperse impurities.

Operation performance test and energy efficiency analysis of ground-source heat pump systems

The improper operation of a ground source heat pump (GSHP) system is a significant cause of poor energy efficiency. Despite the increasing popularity of GSHP systems in China, few field test has been conducted on the operation of GSHP systems in the southwest and western regions of the country, and there is a lack of comprehensive comparative study. This study tested the operation performance of 26 GSHP systems in Sichuan, Chongqing, and Shaanxi under typical operation conditions. The performances indexes of the systems were calculated and investigated, including the coefficients of performance of the heat pump and system, water transfer factor of the water pump, and energy efficiency ratio of the system. These parameters were then compared and analyzed based on existing literature and relevant domestic standards concerning energy efficiency. Accordingly, suggestions were proposed for improving the operation performance of GSHP systems from the aspects of system design, construction, and operation. Results show that the average coefficient of performance (COP) of the tested systems was less than 3.0 under heating conditions, which did not meet the requirements for energy-saving operation stipulated by the national standard and fail to achieve the initial intention of saving energy in buildings by using GSHP systems. Based on the analysis, typical problems were diagnosed in GSHP systems. Specifically, the heat pumps usually operate in part-load conditions and at low efficiency for a long time; the transfer and distribution systems operate with small temperature differences and large flows; and the settings of room temperatures tend to be unreasonable. In view of the operation performance, ground-coupled heat pump (GCHP) systems are recommended for use in the western regions of China.

Efficiency Analysis and Optimization Method of Power-Relay IPT Systems for Reefer Containers

In order to get rid of plug-in/out actions for container terminals and to save space, a power-relay inductive power transfer system is employed for reefer container wireless charging. Besides, a load-power-based efficiency model is proposed to analyze system efficiency. The function of efficiency against the input voltage and the load power distributions of the system is analyzed in detail. Then, system efficiency can be improved by regulating the input voltage according to the input-voltage-lookup table, which is generated as per various power distributions of loads. Finally, a prototype with three loads is built to validate the performance of the proposed approach. The experimental results show that the efficiency is greater than 94.29% with an improvement by 7.6%, 7.2%, and 6.0%, compared with those without optimization (fixed input voltage 213 V) at one load (@80 W), two loads (@80 and 80 W), and three loads (@80, 80, and 80 W), respectively.

Theoretical Comparative Energy Efficiency Analysis of Dual Axis Solar Tracking Systems

This paper developed a theoretical model substantially based on the principle that only the normal component of solar radiation is actually converted into electrical energy. This theoretical model helped to predict minimum and maximum daily energy gain (compared to static PV system tilted with certain angle) when using dual axis PV solar tracking systems, at any given location on earth without prior experimental data. Based on equations derived from model, minimum and maximum energy gain is computed and summarized in tables of minimum and maximum. Furthermore, the model equations could be used to set up future experimental studies related to the matter.

Economic and stochastic efficiency analysis of alternative cover crop systems in Louisiana

SummaryLandowners can engage in voluntary conservation with the help of incentive programs. Recommended conservation practices are selected based on management intentions as well as the contribution of those practices to the overall net returns. However, conservation motives are heterogeneous and based on individual risk behavior. Existing cost-share programs might either under-fund or over-fund conservation, which could lead to inefficient management of natural resources. The current analysis evaluates the economic feasibility of variable cover crop strategies, multiple seeding rates, within a soybean production system in silt loam and clay soils. The study utilizes stochastic efficiency with respect to a function, referred to as SERF, for determining the preferred strategies under various risk preferences. The SERF method accounts for the heterogeneity of individual decision-making with regards to conservation adoption. Results indicate that most risk-averse farmers chose tillage radish with medium seeding rate as their preferred strategy. However, as the risk-bearing capacity of an individual increases, the current level of incentives does not motivate to implement conservation. The most preferred plan for risk-neutral farmers is the fallow system in both silt loam and clay soils. The economic and risk assessment framework can improve understanding of the temporal dynamics of different practices and inform policy on conservation structure that promotes agricultural systems that are economically, environmentally, and socially sustainable.

Fuzzy control in the simulation model of airport baggage handling systems

The object of the research is the airport baggage handling system with a significant share of transfer passengers. It is proposed to include into the composition of simulation models used in solving problems of efficiency analysis and design of baggage handling systems, a fuzzy algorithm that simulates the strategy of a human operator who controls the process of pre-flight passenger service and baggage handling in the airport terminal. In practice, management ensures the economy of the airport resources, the ability to maneuver personnel and technical means in order to reduce the unproductive time spent on ground handling and improve its quality. An algorithm of fuzzy inference on a singleton rule base is described, which can be considered as a special case of the Mamdani algorithm. The results of solving problems of computer statistical modeling using a fuzzy control algorithm are presented, indicating the need to take into account the control of ground processes to increase the adequacy and accuracy of simulation models of baggage handling systems.

Water pump flow monitoring method for air conditioning system based on parameter model

The widespread development and application of virtual sensors in buildings will play an important role in promoting industry change and achieving smart buildings. In this study, a virtual monitoring method of pump flow rate was developed and verified. First, the pump flow parameter model was constructed based on pump operating parameters. Then, the calibration process of the model and the identification process of the pump-related efficiency were given. Finally, the experimental platform and the actual project were used to verify the virtual monitoring method of pump flow. The results showed that for the experimental test, the mean relative errors (MREs) of the three proposed methods are less than 1.79 %; for the actual project, the MREs are less than 2.48 %. Compared with existing methods, the prediction accuracies of the proposed methods have been significantly improved, and the methods are suitable for different application scenarios of pumps (with and without VFDs installed). Meanwhile, the parameters required for model calibration of proposed methods are easier to obtain. The introduction of proposed virtual monitoring methods will contribute to the replacement or backup of existing flow meters, efficiency analysis of pump systems, system fault detection and optimization control, and implementation of smart building systems.

Efficiency analysis of viticulture systems in the Portuguese Douro region

PurposeThe purpose of this paper is to estimate and analyse the technical efficiency (TE) component of productivity for a sample of winegrowers from the Douro Demarcated Region in Portugal.Design/methodology/approachThe data were collected through face-to-face surveys and includes a sample of 110 farmers’ vineyards with specific input-output information and other data about production systems during the year of 2017. The authors use a two-stage data envelopment analysis using bootstrap techniques to obtain TE scores in the farmers’ vineyards and to examine the determinants of its efficiency.FindingsThe results show that some farmers’ vineyards have a low efficiency level and that there are essential determinants of the production system, which can influence its efficiency. This suggests considerable opportunities for improvement of wine grape productivity through better use of available resources considering the state of technology.Originality/valueThis work has overcome the lack of data in the farmers’ vineyards, the lack of efficiency studies in the region and also allowed to evaluate the production systems and to assess their impact on efficiency.

Comparative Water Efficiency Analysis of Sole and Multiple Cropping Systems under Tunnel Farming in Punjab-Pakistan

Water scarcity is the growing concern of present times, requiring its efficient utilization deemed as necessity. Rapidly growing population has significantly exerted pressure on its demand, in Pakistan. In order to fulfill it, all factors of production are required to be used in the possibly most efficient way. Good quality and quantity of water are the growing concerns of producers in Pakistan and around the globe. The efficient water utilization is crucial to optimize the farm returns under the selected sole and multiple cropping systems. This study considered the water efficiency analysis of multiple and sole cropping systems, with the aim of finding out cropping patterns more efficient in terms of water utilization in Pakistan. In order to estimate the water efficiency analysis, the Data Envelopment Analysis (DEA) is run to find out the water efficient cropping systems among sole and multiple cropping systems. The Tobit analysis is also used to find out the factors affecting the water efficiency of selected farms in the study area. The results of the study report an inefficient water usage in terms of irrigation, the inefficient use of water instigates the wastage of one of the most important as well as scarce farm inputs especially water, in case of multiple cropping system. Around 51% and 13% of water inefficiency are present under multiple and sole cropping systems, respectively. Basin irrigation is the method for irrigation, used by the farmers of the study area approximating to be 95% - 97%. It is one of the most conventional and least efficient methods of irrigation. Only 2.67 and 4.67 percent of farms were using the Furrow irrigation method, which is way more efficient and steady as compared to Basin irrigation method, respectively. It appears as a requirement that the most efficient methods regarding water application in Pakistan should be recognized. Lack of management in water application on both selected cropping systems resulted in over utilization of water and depletion of one of the fundamental natural resource. In order to overcome the inefficiency in water management, farmers’ farming knowledge, adoption of new irrigation techniques, efficient application of inputs is needed.

Efficiency analysis of photovoltaic systems

The goal of the study was to analyse the efficiency of two existing photovoltaic micro-installations with the power of approx. 40 kWp. The main factor differing the two installations being analysed was the arrangement of modules in relation to the sides of the world, one is south-west and the other is east-west. The total yield of electrical energy in 2017 from the south-west installation was higher and amounted to 34980 kWh. For the east-west installation the amount of energy generated was equal to 31180 kWh. 4 methods of forecasting electrical energy yield were discussed. Simple computational method proved to be the best method for both installations.