Artigos de revistas: "Performances of systems"

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ROTARU, Constantin, Janel TANASE, Oliver CIUICA e Eduard MIHAI. "COAXIAL ROTOR SYSTEMS – CHARACTERISTICS AND PERFORMANCES". SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE 20 (18 de junho de 2018): 233–38. http://dx.doi.org/10.19062/2247-3173.2018.20.31.

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Lee, Jae K., Mark S. Fox e Paul R. Watkins. "Scheduling expert systems and their performances". Expert Systems with Applications 6, n.º 3 (julho de 1993): 217. http://dx.doi.org/10.1016/0957-4174(93)90050-g.

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Andersen, E., L. J. Shah e S. Furbo. "Thermal Performance of Danish Solar Combi Systems in Practice and in Theory". Journal of Solar Energy Engineering 126, n.º 2 (1 de maio de 2004): 744–49. http://dx.doi.org/10.1115/1.1688381.

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An overview of measured thermal performances of Danish solar combi systems in practice is given. The thermal performance varies greatly from system to system. Measured and calculated thermal performances of different solar combi systems are compared and the main reasons for the different thermal performances are given. Further, a parametric study on two solar combi system types is performed. Based on the investigation it can be concluded that the thermal performance first of all is influenced by the space heating consumption during the summer period and that the systems in practice perform as theoretically expected.

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Umnuayponwiwat, Suwan, e Erdal Ozkan. "Evaluation of Inflow Performance of Multiple Horizontal Wells in Closed Systems". Journal of Energy Resources Technology 122, n.º 1 (25 de outubro de 1999): 8–13. http://dx.doi.org/10.1115/1.483155.

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This work presents a model to investigate the inflow performance relationships (IPR) of horizontal and vertical wells in a multi-well pattern. The model can be used to compute the overall and individual well performances. It is shown that stabilized IPRs may not be sufficient for the evaluation of horizontal well performances due to prolonged transient flow periods. The results presented in this paper clearly indicate that inflow performance of wells in a multi-well pattern is a dynamic concept; and, especially in the prediction of future performances, dynamic rather than static IPR models should be used. [S0195-0738(00)00801-3]

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Németh, Balázs. "Coordination of Lateral Vehicle Control Systems Using Learning-Based Strategies". Energies 14, n.º 5 (26 de fevereiro de 2021): 1291. http://dx.doi.org/10.3390/en14051291.

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The paper proposes a novel learning-based coordination strategy for lateral control systems of automated vehicles. The motivation of the research is to improve the performance level of the coordinated system compared to the conventional model-based reconfigurable solutions. During vehicle maneuvers, the coordinated control system provides torque vectoring and front-wheel steering angle in order to guarantee the various lateral dynamical performances. The performance specifications are guaranteed on two levels, i.e., primary performances are guaranteed by Linear Parameter Varying (LPV) controllers, while secondary performances (e.g., economy and comfort) are maintained by a reinforcement-learning-based (RL) controller. The coordination of the control systems is carried out by a supervisor. The effectiveness of the proposed coordinated control system is illustrated through high velocity vehicle maneuvers.

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Mandal, Sumit, Simon Annaheim, Andre Capt, Jemma Greve, Martin Camenzind e René M. Rossi. "A categorization tool for fabric systems used in firefighters' clothing based on their thermal protective and thermo-physiological comfort performances". Textile Research Journal 89, n.º 16 (31 de outubro de 2018): 3244–59. http://dx.doi.org/10.1177/0040517518809055.

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Fabric systems used in firefighters' thermal protective clothing should offer optimal thermal protective and thermo-physiological comfort performances. However, fabric systems that have very high thermal protective performance have very low thermo-physiological comfort performance. As these performances are inversely related, a categorization tool based on these two performances can help to find the best balance between them. Thus, this study is aimed at developing a tool for categorizing fabric systems used in protective clothing. For this, a set of commercially available fabric systems were evaluated and categorized. The thermal protective and thermo-physiological comfort performances were measured by standard tests and indexed into a normalized scale between 0 (low performance) and 1 (high performance). The indices dataset was first divided into three clusters by using the k-means algorithm. Here, each cluster had a centroid representing a typical Thermal Protective Performance Index (TPPI) value and a typical Thermo-physiological Comfort Performance Index (TCPI) value. By using the ISO 11612:2015 and EN 469:2014 guidelines related to the TPPI requirements, the clustered fabric systems were divided into two groups: Group 1 (high thermal protective performance-based fabric systems) and Group 2 (low thermal protective performance-based fabric systems). The fabric systems in each of these TPPI groups were further categorized based on the typical TCPI values obtained from the k-means clustering algorithm. In this study, these categorized fabric systems showed either high or low thermal protective performance with low, medium, or high thermo-physiological comfort performance. Finally, a tool for using these categorized fabric systems was prepared and presented graphically. The allocations of the fabric systems within the categorization tool have been verified based on their properties (e.g., thermal resistance, weight, evaporative resistance) and construction parameters (e.g., woven, nonwoven, layers), which significantly affect the performance. In this way, we identified key characteristics among the categorized fabric systems which can be used to upgrade or develop high-performance fabric systems. Overall, the categorization tool developed in this study could help clothing manufacturers or textile engineers select and/or develop appropriate fabric systems with maximum thermal protective performance and thermo-physiological comfort performance. Thermal protective clothing manufactured using this type of newly developed fabric system could provide better occupational health and safety for firefighters.

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Krokavec, Dušan, e Anna Filasová. "Optimal Fuzzy Control for a Class of Nonlinear Systems". Mathematical Problems in Engineering 2012 (2012): 1–29. http://dx.doi.org/10.1155/2012/481942.

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The paper presents conditions suitable in design giving quadratic performances to stabilizing controllers for given class of continuous-time nonlinear systems, represented by Takagi-Sugeno models. Based on extended Lyapunov function and slack matrices, the design conditions are outlined in the terms of linear matrix inequalities to possess a stable structure closest to LQ performance, if premise variables are measurable. Simulation results illustrate the design procedure and demonstrate the performances of the proposed control design method.

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Kai, Caihong, Zhikang Feng, Maxime Irene Dedo, Pei Huang, Kai Guo, Fei Shen, Jun Gao e Zhongyi Guo. "The performances of different OAM encoding systems". Optics Communications 430 (janeiro de 2019): 151–57. http://dx.doi.org/10.1016/j.optcom.2018.08.023.

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Mora-Camino, F., e A. Lopes Pereira. "Controller Performances for Short-headways Transportation Systems". IFAC Proceedings Volumes 23, n.º 2 (setembro de 1990): 85–89. http://dx.doi.org/10.1016/s1474-6670(17)52654-3.

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Buzuloiu, V., e D. Colţuc. "Small image processing systems (performances, architectures, functions)". Computer Physics Communications 50, n.º 1-2 (julho de 1988): 229–35. http://dx.doi.org/10.1016/0010-4655(88)90129-4.

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Bojić, Milorad, Dragan Cvetković, Vesna Marjanović, Mirko Blagojević e Zorica Djordjević. "Performances of low temperature radiant heating systems". Energy and Buildings 61 (junho de 2013): 233–38. http://dx.doi.org/10.1016/j.enbuild.2013.02.033.

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Sato, Kuniaki, Toshiyuki Wakatsuki, Noriko Iwashima e Tsugiyuki Masunaga. "Evaluation of Long-Term Wastewater Treatment Performances in Multi-Soil-Layering Systems in Small Rural Communities". Applied and Environmental Soil Science 2019 (23 de janeiro de 2019): 1–11. http://dx.doi.org/10.1155/2019/1214368.

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Multi-soil-layering (MSL) wastewater treatment systems consist of soil units (soil mixture blocks, SMB) arranged in a brick-like pattern surrounded by permeable layers of zeolite or alternating particles of homogeneous sizes that allow for a high hydraulic loading rate. This study evaluated the performances of MSL systems that have been operating for 17 to 20 years in small rural communities. Even though 20 years had passed since this system was installed, high organic matter treatment performance continued. Nitrogen removal was higher than with conventional soil systems. Two of the MSL systems continued to show high phosphorus removal performances, whereas in the third system, the adsorbing capacity was relatively low, requiring further investigation. Treatment performances were largely dependent upon the structure of the MSL systems. It appeared that improving the structure to enhance the contact efficiency between the wastewater and the soil in SMB was important for enhancing treatment performances. The combined use of existing wastewater treatment systems with the MSL system was effective for preventing environmental pollution over a long period.

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Besagni, Giorgio, Lorenzo Croci, Nicolò Cristiani, Gaël Raymond Guédon e Fabio Inzoli. "Refrigerant selection for ejector refrigeration systems: a multiscale evaluation". E3S Web of Conferences 197 (2020): 10011. http://dx.doi.org/10.1051/e3sconf/202019710011.

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The selection of refrigerants for ejector refrigeration systems, within the broader discussion concerning refrigerant phase-out, is a cutting-edge and challenging research topic, owing to the multi-scale challenges in ejector performance. Indeed, it is known that the performances of ejector refrigeration systems depend on the local flow phenomena. For this reason, a precise selection of the refrigerant relies on the understanding of the fluid dynamic phenomena at the “componentscale”, and integrate such information within the so-called “system-scale”. This paper contributes to the current discussion proposing a screening of refrigerants based on an integrated Computational Fluid Dynamic (CFD) Lumped Parameter Model (LPM) approach. In this approach, ejector performances for the different refrigerant are obtained by a validated CFD approach, whereas the cycle is modelled by a Lumped Parameter Model. For the different refrigerants, the energy performances of the systems are evaluated and the effects of the “component-scale” on the “system-scale” are analysed.

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Bauwens, Robin. "Prestatiemanagement in het Hoger Onderwijs:". Tijdschrift voor HRM 24, n.º 2 (1 de junho de 2021): 39–60. http://dx.doi.org/10.5117/thrm2021.2.bauw.

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SUMMARY This paper deals with the question of how we can improve performance management systems in higher education institutions. Performance management systems are defined as configurations of complementary human resource management (HRM) practices that enable organizations to set goals, give feedback and evaluate the efforts of their employees. Higher education institutions have adopted performance management systems to manage their staff more efficiently and effectively against the backdrop of challenges like democratization, marketization and public accountability. However, in higher education institutions, such systems often result in unintended effects on academic employees’ well-being and performances. Like burnout, reduced innovation and lower team performances. This particularly applies to non-professorial higher education staff. In response, scholars have started to inquire into the ‘success conditions’, particular conditions under which the unintended effects of performance management systems can be avoided or reversed. Drawing on four empirical studies, this paper examined how and when performance management systems yield positive outcomes for the well-being and performance of academic employees in higher education institutions. The findings show that performance management systems have positive synergies with both employees’ well-being and performances (mutual gains). In addition, leaders are observed to be key supporters of performance management systems. However, they should not be regarded as a panacea, as our findings also seem to suggest a more complex interplay. Such findings contrast with the dysfunctional effects of performance management systems as described in higher education literature. However, it is important to remain critical. The main message is that academic employees’ personal perceptions of performance management implementation are a force to be reckoned with in striving for healthy and performant academic employees. Therefore, the subsequent challenge moves to managing those perceptions and building academic leaders.

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Morrone, Pietropaolo, e Angelo Algieri. "Biomass Exploitation in Efficient ORC Systems". Applied Mechanics and Materials 260-261 (dezembro de 2012): 77–82. http://dx.doi.org/10.4028/www.scientific.net/amm.260-261.77.

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The research intends to investigate the energetic performances of Organic Rankine Cycles (ORCs) for the exploitation of the biomass resulting from agricultural residues. To this purpose, a parametric analysis has been carried out. Saturated and superheated conditions at the turbine inlet have been imposed and the effect of the internal regeneration on plant performances has been studied. The results highlight that ORC plants represent an interesting and sustainable solution for small-scale and decentralised power production. Moreover, the analysis shows the significant impact of the temperature and internal regeneration technique on the performances of the biomass power plants.

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Wang, Hong. "Research on the Structure Design of Operating Systems". Applied Mechanics and Materials 198-199 (setembro de 2012): 474–79. http://dx.doi.org/10.4028/www.scientific.net/amm.198-199.474.

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Operating system, as the core software, influences or even decides the performance of the whole computer system. And its performance is directly related to its structure. This paper discusses the classification of modular structure designs, shows some typical structures of operating systems, studies the composition and features of these structures, analyzes and compares performances of operating systems of different structures. Finally, it points out the trend for the structure design.

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Wasesa, Meditya, Andries Stam e Eric van Heck. "Investigating agent-based inter-organizational systems and business network performance". Journal of Enterprise Information Management 30, n.º 2 (6 de março de 2017): 226–43. http://dx.doi.org/10.1108/jeim-07-2015-0069.

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Purpose From the theoretical perspectives of both multi-agent systems and smart business networks, empirical studies analyzing agent-based inter-organizational systems (ABIOS) in a real-life business setting are rare. The purpose of this paper is to investigate the impact of ABIOS on the performance of business networks. Design/methodology/approach This study presents a theoretical conceptual model portraying the influence of ABIOS on clients’ coordination structure and information architecture; and the impact of those structural alterations on business network performance in terms of the coordination, agility, and informational performances. To validate the model, a cross-case analysis was conducted in three logistics cases, namely, warehousing, freight forwarding, and intermodal transportation. Findings The application of ABIOS requires adjustments to the information architecture or the coordination structure, or both. Subsequently, those structural adjustments will stimulate improvements in the coordination, agility, and informational performances. Research limitations/implications The assessment of the clients’ performance improvement is done at the company level not at an aggregate network level. Moreover, the study only covers cases from the logistics sector. Practical implications This study explains the structural consequences of ABIOS applications. The adoption of an inter-organizational system is a strategic decision that requires support from multi-stakeholders. While the applications of ABIOS can offer performance improvement opportunities, adjustments must be made to the existing coordination structure or the information architecture, or both. Originality/value This study contributes to the smart business network literature and the ABIOS literature by presenting a validated conceptual model explaining the interplay among ABIOS, the coordination structure, informational structure, and business network performance, namely, the coordination, agility, and informational performances.

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Zhang, Purui, Xiaoqian Chen e Xiaogang Yang. "Guaranteed Cost Formation Tracking Control for Swarm Systems with Intermittent Communications". Complexity 2020 (12 de novembro de 2020): 1–13. http://dx.doi.org/10.1155/2020/8816578.

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The current paper studies guaranteed cost time-varying formation tracking design and analysis problems of high-order swarm systems subject to intermittent communications. Different from the existing work of the time-varying formation control, the time-varying formation tracking can be achieved while certain performance can be guaranteed, and the impacts of the intermittent communications and switching topologies are considered. First, a new intermittent time-varying formation tracking control protocol with a global performance index is proposed, where not only the formation regulation performances but also the control energy expenditures are involved. The codesign of the gain matrix with the performance index is achieved to compromise the formation regulation performances against control energy expenditures, and the guaranteed cost is determined to restrain the upper bound of the performance index. Then, guaranteed cost time-varying formation tracking design and analysis criteria are given, where the matrix variable of the linear matrix inequality conditions is used to design the gain matrix and to determine the guaranteed cost. Finally, a simulation example is provided to illustrate the effectiveness of the theoretical results.

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Liu, Chen-Chung, Gwo-Dong Chen, Chin-Yeh Wang e Ching-Fang Lu. "Student Performance Assessment Using Bayesian Network and Web Portfolios". Journal of Educational Computing Research 27, n.º 4 (dezembro de 2002): 437–69. http://dx.doi.org/10.2190/el2a-tqf1-pyvm-n51v.

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Web-based curriculum development allows students to develop their learning portfolio and interact with peers on a Web learning system. This system contains Web portfolios that record in detail students' learning activities, peer interaction, and knowledge progress. However, teachers cannot easily diagnose students' learning processes and regulate effective strategies according to student activity performance without the model of activity performance on Web learning systems. This study proposes a novel methodology that employs Bayesian network software to assist teachers in efficiently deriving and utilizing the student model of activity performance from Web portfolios in an online manner. Teachers can assess and diagnose performances with the model of learning activity on Web learning systems. The model of activity performance also allows teachers to manage various activity performances in Web learning systems so that desired strategies can be achieved to promote learning effectiveness.

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Ben Amara, Foued, Pierre T. Kabamba e A. Galip Ulsoy. "Adaptive Sinusoidal Disturbance Rejection in Linear Discrete-Time Systems—Part II: Experiments". Journal of Dynamic Systems, Measurement, and Control 121, n.º 4 (1 de dezembro de 1999): 655–59. http://dx.doi.org/10.1115/1.2802531.

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The problem of adaptive noise cancellation in an acoustic duct is discussed. An adaptive controller design approach based on parametrizing the set of stabilizing controllers using the Youla parametrization and tuning the Youla parameter to achieve regulation was presented in a companion paper [3]. Three controller adaptation algorithms are implemented to solve the noise cancellation problem in an acoustic duct. The experimental results indicate a mixed performance for each of the adaptation algorithms, with good performances observed only in some frequency ranges. The discrepancy between the expected and the observed performances is attributed to unmodeled nonlinearities in the speakers.

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Su, Qingyu, Xiaolong Jia e Zhengfan Song. "Fault Detection for Discrete-Time Nonlinear Impulsive Switched Systems". Abstract and Applied Analysis 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/694319.

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This paper investigates the fault detection problem for discrete-time nonlinear impulsive switched systems. Attention is focused on designing the fault detection filters to guarantee the robust performance and the detection performance. Based on these performances, sufficient conditions for the existence of filters are given in the framework of linear matrix inequality; furthermore, the filter gains are characterized by a convex optimization problem. The presented technique is validated by an example. Simulation results indicate that the proposed method can effectively detect the faults.

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Zheng, Jianfeng, Yue Li e Zhenghe Feng. "Impact of Mutual Coupling and Polarization of Antennas on BER Performances of Spatial Multiplexing MIMO Systems". International Journal of Antennas and Propagation 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/795205.

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This paper is aimed at studying the impacts of mutual coupling, matching networks, and polarization of antennas on performances of Multiple-Input Multiple-Output (MIMO) systems employing Spatial Multiplexing (SM). In particular, the uncoded average Bit Error Rate (BER) of MIMO systems is investigated. An accurate signal analysis framework based on circuit network parameters is presented to describe the transmit/receive characteristics of the matched/unmatched antenna array. The studied arrays consist of matched/unmatched compact copolarization and polarization diversity antenna array. Monte-Carlo numerical simulations are used to study the BER performances of the SM MIMO systems using maximum-likelihood and/or zero-forcing detection schemes. The simulation results demonstrate that the use of matching networks can improve the BER performance of SM MIMO systems significantly, and the BER performance deterioration due to antenna orientation randomness can be compensated by use of polarization diversity antenna arrays.

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Ruben, Ruerd, Romina Cavatassi, Leslie Lipper, Eric Smaling e Paul Winters. "Towards food systems transformation—five paradigm shifts for healthy, inclusive and sustainable food systems". Food Security 13, n.º 6 (15 de outubro de 2021): 1423–30. http://dx.doi.org/10.1007/s12571-021-01221-4.

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AbstractFood systems must serve different societal, public health and individual nutrition, and environmental objectives and therefore face numerous challenges. Considering the integrated performances of food systems, this paper highlights five fundamental paradigm shifts that are required to overcome trade-offs and build synergies between health and nutrition, inclusive livelihoods, environmental sustainability and food system resilience. We focus on the challenges to raise policy ambitions, to harmonize production and consumption goals, to improve connectivity between them, to strengthen food system performance and to anchor the governance of food systems in inclusive policies and participatory institutions. Taken together, these shifts in paradigms shape a new discourse for food system transformation that will be capable to respond to current and future policy challenges.

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Ifrim, V.-C., L.-D. Milici e C. Bejenar. "Review on solar air heater hybrid systems thermal performances". IOP Conference Series: Materials Science and Engineering 1254, n.º 1 (1 de setembro de 2022): 012013. http://dx.doi.org/10.1088/1757-899x/1254/1/012013.

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Abstract As conventional fossil fuel systems release toxicants into the atmosphere, humanity is increasingly moving towards sustainability, towards using products that do not cause negative effects on the environment, have a long service life and offer multiple benefits. Solar air heating systems are increasingly used in household applications, even in industrial ones at times. The principle of operation of systems of this type is established on the existence of solar radiance, without this the panels have little or no efficiency at all, so they are limited to sunny periods. One of the methods of increasing the impact and performance of these systems is the realization of hybrid systems that offer several benefits with regard to heating the air in rooms, heating water and ventilating spaces. The meaning of this article is to present a summary of the existing literature, in the sphere of solar hybrid air heating systems, on the methods of improvement and the performance achieved.

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Srimathi, R., J. Meenakshi, R. Vijayabhasker e Semagn Shifere Belay. "Performance Evaluation and Estimation of Energy Measures of Grid-Connected PV Module". International Journal of Photoenergy 2022 (28 de setembro de 2022): 1–13. http://dx.doi.org/10.1155/2022/7228470.

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In this paper, the effectiveness of two grid-connected photovoltaic (PV) techniques up of copper indium selenium (CIS) and monocrystalline silicon (m-Si) arrays has been examined. In order to determine whether the technology is suitable for the actual winter and summer climatic conditions in Thoothukudi, Tamil Nadu, the observed and calculated performances have been compared. The final yield, photovoltaic (PV) effectiveness, array yield, performance ratio, and capacity utilisation factor seem to be the variables used to evaluate performance. Using recorded meteorological data at the selected location, PVsyst software predicts both PV systems’ year-round performances. These predictions are then contrasted to the outcomes of the actual measurements. The outcome showed that with a maximal observed performance ratio, both PV systems function marginally better in the winters than those in the summers. The performance indicators of the PV mechanisms are contrary with those of other PV systems with comparable capacities that are located in different places.

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Pekel, Feyzi Osman. "PISA RESULTS OR X-RAY FILMS OF EDUCATION SYSTEMS?" Problems of Education in the 21st Century 74, n.º 1 (25 de dezembro de 2016): 4–5. http://dx.doi.org/10.33225/pec/16.74.04.

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To be able to develop well-equipped students in accordance with the expectations of the society is one of the objectives of every education system in every country. In this sense, monitoring student performance comparatively at international level, assessing students and schools characteristics is crucially important in order to structuring individuals’ future lives. Determining student performances in different subject areas is a way for the countries examining the performance of their education systems (Anagün, 2011). Results of these assessments and evaluations enable steering the educational policy by diagnosing/revising the failures of the system.

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Zarkov, Zahari, Ludmil Stoyanov, Hristiyan Kanchev, Valentin Milenov e Vladimir Lazarov. "Study of Photovoltaic Systems’ Performances with Different Module Types". Materials Science Forum 856 (maio de 2016): 279–84. http://dx.doi.org/10.4028/www.scientific.net/msf.856.279.

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The purpose of the work is to study and compare the performance of photovoltaic (PV) generators built with different types of panels and operating in real weather conditions. The paper reports the results from an experimental and theoretical study of systems with PV modules manufactured according to different technologies and using different materials. The experiment was carried out at a research platform for PV systems developed by the authors, built and located at an experimental site near the Technical University of Sofia. Based on the obtained results, comparisons are made between the different PV generators for the same operating conditions. The comparison between the theoretical and the experimental results demonstrates a good level of overlap.

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Larrodé, Emilio, e Victoria Muerza. "European Modular Systems performances comparison in freight transport operations". Transportation Research Procedia 58 (2021): 165–72. http://dx.doi.org/10.1016/j.trpro.2021.11.023.

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Hara, Shinji, Toni Bakhtiar e Masaaki Kanno. "The Best Achievableℋ2Tracking Performances for SIMO Feedback Control Systems". Journal of Control Science and Engineering 2007 (2007): 1–12. http://dx.doi.org/10.1155/2007/93904.

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This paper is concerned with the inherentℋ2tracking performance limitation of single-input and multiple-output (SIMO) linear time-invariant (LTI) feedback control systems. The performance is measured by the tracking error between a step reference input and the plant output with additional penalty on control input. We employ the plant augmentation strategy, which enables us to derive analytical closed-form expressions of the best achievable performance not only for discrete-time system, but also for continuous-time system by exploiting the delta domain version of the expressions.

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Nathan, Hari, Gilles Mentha, Hugo P. Marques, Lorenzo Capussotti, Pietro Majno, Luca Aldrighetti, Carlo Pulitano et al. "Comparative performances of staging systems for early hepatocellular carcinoma". HPB 11, n.º 5 (agosto de 2009): 382–90. http://dx.doi.org/10.1111/j.1477-2574.2009.00070.x.

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Carrassi, Alberto, Stephane Vannitsem, Dusanka Zupanski e Milija Zupanski. "The maximum likelihood ensemble filter performances in chaotic systems". Tellus A: Dynamic Meteorology and Oceanography 61, n.º 5 (janeiro de 2008): 587–600. http://dx.doi.org/10.1111/j.1600-0870.2009.00408.x.

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Benghanem, M. "Performances of photovoltaic water pumping systems: a case study". International Journal of Renewable Energy Technology 1, n.º 2 (2009): 155. http://dx.doi.org/10.1504/ijret.2009.027988.

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Chen, Ten-Hong, e Jia-Chern Wang. "Performances of mesophilic anaerobic digestion systems treating poultry mortalities". Journal of Environmental Science and Health, Part B 33, n.º 4 (julho de 1998): 487–510. http://dx.doi.org/10.1080/03601239809373158.

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Xu, Chang, Zihan Li, Shanyong Wang, Shuren Wang, Lei Fu e Chunan Tang. "Pullout Performances of Grouted Rockbolt Systems with Bond Defects". Rock Mechanics and Rock Engineering 51, n.º 3 (8 de dezembro de 2017): 861–71. http://dx.doi.org/10.1007/s00603-017-1373-1.

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Ghedamsi, K., e D. Aouzellag. "Improvement of the performances for wind energy conversions systems". International Journal of Electrical Power & Energy Systems 32, n.º 9 (novembro de 2010): 936–45. http://dx.doi.org/10.1016/j.ijepes.2010.02.012.

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Lobos, Jorge, Christelle Wisniewski, Marc Heran e Alain Grasmick. "Membrane bioreactor performances: comparison between continuous and sequencing systems". Desalination 199, n.º 1-3 (novembro de 2006): 319–21. http://dx.doi.org/10.1016/j.desal.2006.03.075.

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Ruan, Yali, Yingting Luo e Yunmin Zhu. "Globally Optimal Distributed Kalman Filtering for Multisensor Systems with Unknown Inputs". Sensors 18, n.º 9 (6 de setembro de 2018): 2976. http://dx.doi.org/10.3390/s18092976.

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In this paper, the state estimation for dynamic system with unknown inputs modeled as an autoregressive AR (1) process is considered. We propose an optimal algorithm in mean square error sense by using difference method to eliminate the unknown inputs. Moreover, we consider the state estimation for multisensor dynamic systems with unknown inputs. It is proved that the distributed fused state estimate is equivalent to the centralized Kalman filtering using all sensor measurement; therefore, it achieves the best performance. The computation complexity of the traditional augmented state algorithm increases with the augmented state dimension. While, the new algorithm shows good performance with much less computations compared to that of the traditional augmented state algorithms. Moreover, numerical examples show that the performances of the traditional algorithms greatly depend on the initial value of the unknown inputs, if the estimation of initial value of the unknown input is largely biased, the performances of the traditional algorithms become quite worse. However, the new algorithm still works well because it is independent of the initial value of the unknown input.

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Hoffman, Mark S. "Considerations in the Design of Future Retail Point of Service (POS) Terminal Systems". Proceedings of the Human Factors Society Annual Meeting 36, n.º 11 (outubro de 1992): 862–66. http://dx.doi.org/10.1518/107118192786750430.

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Research studies were conducted in three types of retail stores: supermarkets, discount stores, and department stores. The purpose of these studies was to determine how cashiers and associates spend their time servicing customers, the inter-relationships between physical and cognitive workloads, and how these affect system performance. A detailed task analysis of the cashier's activities comparing performances in these stores was completed. Commonalties and differences in task performances were identified and measured. Task performances were grouped into one of three types: physical, POS, and management. The results showed that physical tasks were performed 39% of the total hour in a supermarket, 57% in the discount store, and 25% in the department store. Physical tasks are those most often identified in ergonomic research. Management tasks were more frequent in the department store; these tasks captured redundant information, i.e. tender approval identification that was already available in system files. These results provide a map for identifying and applying macroergonomic research techniques to integrate POS systems with new features into the retail industry.

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Lee, Jong-Geon, Hyeong-Jae Jang, Sungho Tae e Yonghan Ahn. "Establishment and Utilization Plans of Apartment Housing Envelope System Database". Sustainability 14, n.º 8 (18 de abril de 2022): 4859. http://dx.doi.org/10.3390/su14084859.

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Recently, apart from the energy saving of new buildings, various carbon-centered environmental policies for climate change were implemented to improve the energy performance of existing buildings, actively promoting green remodeling businesses. This study proposed a classification system for green remodeling envelope systems to select the applicable representative method and input material for the green remodeling of apartment housing. The system boundaries were divided into the material production stage and construction waste processing stage, and the classification system of the envelope system was implemented for applicable green remodeling. A database for the environmental, economic, and energy performances of the classification system was created. Moreover, a green remodeling evaluation sheet system was proposed. According to our results, the economic, energy, and environmental performances of the proposed combinations of the insulation systems were higher than those of the reference combination by 30%, 10%, and 30%, respectively. Regarding the window systems, the economic and energy performances of the proposed input material combinations were higher than those of the reference combination by 22% and 10%, respectively. Additionally, the energy performance of the proposed input material combinations was higher than that of the reference combination by 8~64%.

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Li, Yue Heng, Ming Hao Fu, Li Wang, Mei Yan Ju e Ping Huang. "Analysis of Distributed MIMO Systems in a Multi-Cell Environment". Applied Mechanics and Materials 696 (novembro de 2014): 183–90. http://dx.doi.org/10.4028/www.scientific.net/amm.696.183.

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This paper focuses its research work on the capacity and outage performances of a distributed multiple-input multiple-output (DMIMO) system in a multi-cell environment. For this purpose, the multi-cell DMIMO structure is modeled first, and based on this model, the so-called blanket communication and selective communication schemes are compared, and the formula of the output signal to interference plus noise ratio (SINR) of the above two schemes are given to illustrate the way of an inter-cell interference affecting the system performance. Then the expressions of the average capacity and outage probability are derived by using the probability density function (PDF) of the output SINR in the preferred selective communication scheme with some necessary approximations. Finally, the computer simulations are provided to explore the possible rule of upper layer network scheduling in overcoming the inter-cell interferences and in optimizing the capacity and outage performances in the DMIMO systems.

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Devise, Olivier, e Henri Pierreval. "Indicators for measuring performances of morphology and material handling systems in flexible manufacturing systems". International Journal of Production Economics 64, n.º 1-3 (março de 2000): 209–18. http://dx.doi.org/10.1016/s0925-5273(99)00059-6.

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Popescu, Madalina, Eva Militaru, Amalia Cristescu, Maria Vasilescu e Monica Maer Matei. "Investigating Health Systems in the European Union: Outcomes and Fiscal Sustainability". Sustainability 10, n.º 9 (6 de setembro de 2018): 3186. http://dx.doi.org/10.3390/su10093186.

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Healthcare systems aim to provide access to good quality care, while ensuring equity and solidarity. The fiscal sustainability of healthcare systems has become a matter of concern in recent European Union (EU) debates, considering the ever increasing need for adequate healthcare determined by factors such as aging population, investments in technology and infrastructure, medical products and wages. Our paper seeks to measure the health system performances of the EU countries by building up a composite index, which will then be used as a tool in investigating the relationship between health performance and the fiscal sustainability of health systems. A principal components analysis (PCA) was applied to build the composite index through the use of the most relevant health indicators provided by Eurostat and the Sustainable Development Knowledge Platform. The composite index offers a comprehensive performance assessment and provides a clear ranking of the EU countries based on their health system performances. Further investigation of the link between health performance and fiscal sustainability revealed that higher ranks are associated with higher shares of health expenditures in gross domestic product (GDP), a large share of employment in the health sector, and higher duration of working life. These patterns are followed by efficient health systems, encountering reduced sustainability risks.

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Iacomussi, Paola. "Metrology Impact of Advanced Driver Assistance Systems". Electronic Imaging 2020, n.º 16 (26 de janeiro de 2020): 202–1. http://dx.doi.org/10.2352/issn.2470-1173.2020.16.avm-200.

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Metrological applications to road environment are usually focused on the characterization of the road, considering as measurands several characteristics related to the road as a whole or the performances of single components, like the road surface, lighting systems, active and/or passive signaling and obviously vehicles equipment. In current standards approach, driving on the road means to navigate ”visually” (for a human being driver), the characterizations are mostly photometric performances oriented for given reference conditions and reference observer (photometric observer observing the road from assigned points of view, with given spectral sensitivity). But considering the present and future technological trends and knowledge on visual performances, characterizations based on only photometric quantities in reference conditions as described in the current standards would be not fully suitable, even for human driver visual needs. Nowadays research on components and systems for advanced driver assistance are evolving, following different paths toward different solutions: it is not possible, nor useful to define strict constraints as it has been done previously for road applications measurements. The paper presents the current situation of metrological characterization of road environment and components, on laboratory and on site using mobile high efficiency laboratories, and suggests to use ADAS (Advanced Driver Assistance System) for diffuse mapping of road characteristics for a better understanding of the road environment and maintenance. The suggestion has the additional advantage of minimizing measurement costs, but for its full applicability, the reliability and metrological performances of installed devices and of the measurements performed by ADAS are a priority.

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Candelieri, Antonio, Andrea Ponti, Elisabetta Fersini, Enza Messina e Francesco Archetti. "Safe Optimal Control of Dynamic Systems: Learning from Experts and Safely Exploring New Policies". Mathematics 11, n.º 20 (19 de outubro de 2023): 4347. http://dx.doi.org/10.3390/math11204347.

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Many real-life systems are usually controlled through policies replicating experts’ knowledge, typically favouring “safety” at the expense of optimality. Indeed, these control policies are usually aimed at avoiding a system’s disruptions or deviations from a target behaviour, leading to suboptimal performances. This paper proposes a statistical learning approach to exploit the historical safe experience—collected through the application of a safe control policy based on experts’ knowledge— to “safely explore” new and more efficient policies. The basic idea is that performances can be improved by facing a reasonable and quantifiable risk in terms of safety. The proposed approach relies on Gaussian Process regression to obtain a probabilistic model of both a system’s dynamics and performances, depending on the historical safe experience. The new policy consists of solving a constrained optimization problem, with two Gaussian Processes modelling, respectively, the safety constraints and the performance metric (i.e., objective function). As a probabilistic model, Gaussian Process regression provides an estimate of the target variable and the associated uncertainty; this property is crucial for dealing with uncertainty while new policies are safely explored. Another important benefit is that the proposed approach does not require any implementation of an expensive digital twin of the original system. Results on two real-life systems are presented, empirically proving the ability of the approach to improve performances with respect to the initial safe policy without significantly affecting safety.

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Zhang, Hangbin, Raymond K. Wong e Victor W. Chu. "Hybrid Variational Autoencoder for Recommender Systems". ACM Transactions on Knowledge Discovery from Data 16, n.º 2 (30 de abril de 2022): 1–37. http://dx.doi.org/10.1145/3470659.

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E-commerce platforms heavily rely on automatic personalized recommender systems, e.g., collaborative filtering models, to improve customer experience. Some hybrid models have been proposed recently to address the deficiency of existing models. However, their performances drop significantly when the dataset is sparse. Most of the recent works failed to fully address this shortcoming. At most, some of them only tried to alleviate the problem by considering either user side or item side content information. In this article, we propose a novel recommender model called Hybrid Variational Autoencoder (HVAE) to improve the performance on sparse datasets. Different from the existing approaches, we encode both user and item information into a latent space for semantic relevance measurement. In parallel, we utilize collaborative filtering to find the implicit factors of users and items, and combine their outputs to deliver a hybrid solution. In addition, we compare the performance of Gaussian distribution and multinomial distribution in learning the representations of the textual data. Our experiment results show that HVAE is able to significantly outperform state-of-the-art models with robust performance.

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Cheng, Wei Liang, Hui Ji e An Di. "Thermoeconomic Analysis of Air Conditioning Systems". Advanced Materials Research 875-877 (fevereiro de 2014): 1748–53. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1748.

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In order to decrease the operation costs of air conditioning systems, an evaluation model based on unit thermoeconomic costs of thermoeconomic theory is presented in this paper. By using real components and fictitious components in an air conditioning system, the relationships between the fuel and product are established, and then the operation performances of the air conditioning system can be analyzed and evaluated. The unit thermoeconomic costs can be obtained with the experimental data. The results show that the unit thermoeconomic cost of the system is the lowest when the vaporizing temperature is at 16.3°C, and the unit thermoeconomic cost of the compressor component is the highest. Therefore, the direction and emphases of the technique improvement and performance enhancement are provided.

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Osman, Mai A. R., M. K. A. Rahim, N. A. Samsuri, M. K. Elbasheer e M. E. Ali. "Textile UWB Antenna Bending and Wet Performances". International Journal of Antennas and Propagation 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/251682.

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The vision and ideas of wearable computing systems describe future electronic systems as an integral part of our everyday clothing that provides the wearer with such intelligent personal assistants. Recently, there has been growing interest in the antenna community to merge between wearable systems technology, ultrawideband (UWB) technology and textile technology. This work aimed to make closer steps towards real wearability by investigating the possibilities of designing wearable UWB antenna where textile materials are used for the substrate as well as the conducting parts of the designed antenna. Two types of conducting materials have been used for conducting parts, while a nonconducting fabric has been used as antenna substrate material. A set of comparative results of the proposed design were presented and discussed. Moreover, effects on the return loss by means of measurements for each fabricated antenna prototype under bent and fully wet conditions were discussed in more details.

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Vdovjak, Krešimir, Josip Balen e Krešimir Nenadić. "Experimental Evaluation of Desktop Operating Systems Networking Performance". International journal of electrical and computer engineering systems 11, n.º 2 (24 de junho de 2020): 67–76. http://dx.doi.org/10.32985/ijeces.11.2.2.

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The rapid advancement of network, communication and Internet technology resulted with always-on, always-connected, device-independent and remote online working, business, education and entertainment environment. Consequently, users are searching for solutions and technologies that enable fast and reliable wide area network connection and the typical solution is through using personal computers connected with ethernet cable to network equipment and infrastructure that supports gigabit ethernet connection. Besides the complex network infrastructure that can influence performance, the bottleneck can also be caused by insufficient hardware, operating system and software resources on clients’ machines. Therefore, in this paper a networking performance evaluation of three globally most common and most used versions of Windows operating systems; namely Windows 7TM, Windows 8.1TM and Windows 10TM, on two identical computer systems, is conducted. Networking performance measurements are performed with three different benchmarks: namely iPerf, D-ITG and NetStress. Performance evaluation results showed that a newer versions of an operating system bring certain networking performance improvements but by sacrificing other performances.

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Zhang, Xinkai, e Justin Bradley. "Rethinking Sampled-Data Control for Unmanned Aircraft Systems". Sensors 22, n.º 4 (16 de fevereiro de 2022): 1525. http://dx.doi.org/10.3390/s22041525.

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Unmanned aircraft systems are expected to provide both increasingly varied functionalities and outstanding application performances, utilizing the available resources. In this paper, we explore the recent advances and challenges at the intersection of real-time computing and control and show how rethinking sampling strategies can improve performance and resource utilization. We showcase a novel design framework, cyber-physical co-regulation, which can efficiently link together computational and physical characteristics of the system, increasing robust performance and avoiding pitfalls of event-triggered sampling strategies. A comparison experiment of different sampling and control strategies was conducted and analyzed. We demonstrate that co-regulation has resource savings similar to event-triggered sampling, but maintains the robustness of traditional fixed-periodic sampling forming a compelling alternative to traditional vehicle control design.

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Fang, Lanting, Lenan Wu e Yudong Zhang. "A Novel Demodulation System Based on Continuous Wavelet Transform". Mathematical Problems in Engineering 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/513849.

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Considering the problem of EBPSK signal demodulation, a new approach based on the wavelet scalogram using continuous wavelet transform is proposed. Our system is twofold: an adaptive wavelet construction method that replaces manual selection existing wavelets method and, on the other hand, a nonlinear demodulation system based on image processing and pattern classification is proposed. To evaluate the performance of the adaptive wavelet and compare the performance of the proposed system with the existing systems, a series of comprehensive simulation experiments is conducted under the environment of uniform white noise, colored noise, and additive white Gaussian noise channel, respectively. Simulation results of different wavelets show that the system using adaptive wavelet has lower bit error rate (BER). Moreover, simulation results of several systems show that the BER of the proposed system is the lowest among all systems, such as amplitude detection, integral detection, and some continuous wavelet transform systems (specific scales and times and maximum lines). In a word, the adaptive wavelet construction proposed in this paper yields superior performances compared with the manual selection, and the proposed system has better performances than the existing systems. Index terms are signal demodulation, adaptive wavelet, continuous wavelet transform, and BER.

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