Individual Performance Parameters Research Articles

A Deep Learning Approach to Predict In-Cylinder Pressure of a Compression Ignition Engine

Abstract As emissions regulations for greenhouse gas emissions become more strict, it is important to increase the efficiency of engines by improving on the design and operation. Current optimization methods involve performing large numbers of experimental investigations on physical engines or making use of detailed Computational Fluid Dynamics modeling efforts to provide visual and statistical insights on in-cylinder behavior. The latter still requires experimental data for model validation. Both of these methods share a common set of problems, that of being monetarily expensive and time consuming. Previous work has proposed an alternative method for engine optimization using machine learning (ML) models and experimental validation data to predict scalar values representing different parameters. With such models developed, one can then quickly iterate on operating conditions to find the point that maximizes an application-dependent reward function. While these ML methods provide information on individual performance parameters, they lack key information of in-cylinder indicators such as cylinder pressure traces and heat release curves that are traditionally used for performance analysis. This work details the process of implement- ing a Multilayer Perceptron (MLP) model capable of accurately predicting crank-angle resolved high-speed in-cylinder pressure using equivalence ratio, fuel injection pressure and injection timing as input features. It was demonstrated that the model was able to approximate engine behavior with mean squared error lower than 0.05 on a 1-55 range in the test set. This approach shows potential for greatly accelerating the optimization process in engine applications.

Efficient D-π-π-A-Type Dye Sensitizer Based on a Benzothiadiazole Moiety: A Computational Study.

The design of highly efficient sensitizers is one of the most significant areas in dye-sensitized solar cell (DSSC) research. We studied a series of benzothiadiazole-based D-π-π-A organic dyes, putting emphasis on the influence of the donor moiety on the DSSC's efficiency. Using (linear-response time-dependent) density functional theory ((TD)DFT)) with the CAM-B3LYP functional, different donor groups were characterized in terms of electronic absorption spectra and key photovoltaic parameters. As a reference, a dye was considered that had a benzothiadiazole fragment linked via thiophene rings to a diphenylamine donor and a cyanoacrylic-acid acceptor. The different systems were first studied in terms of individual performance parameters, which eventually aggregated into power conversion efficiency. Only the amino-substituted species showed a modest increase, whereas the dimethylamino case showed a decrease.

Relative age effect and performance in elite youth male basketball

The aims of the study were to (i) assess the Relative Age Effect (RAE) on elite young male basketball players, (ii) to analyze whether there is a difference between birth quarters (BQ) according to their minutes played and efficiency ratings as individual performance parameters and, (iii) to analyze the relationship between team efficiency, team success, and RAE with a new approach. The research was conducted on 678 players (Age:15.84 ± 0.42) from 53 teams in six different tournaments (from 2014 to 2019). Although, chi-square test showed that more players were born in first BQ than in all other BQs (p < 0.05), no significant difference between BQs and performance measures was found (p > 0.05). However, a relationship between team RAE score, tournament ranking, and team efficiency score was found (p < 0.05). Furthermore, there was a relationship between tournament rankings and team RAE rankings (p < 0.05). While players born in the first months of the year were more likely to be selected for the national youth teams, performance parameters did not show any significant difference when compared to other players who were born later in the same year. However, results showed that teams that have a higher number of athletes who were born in the earlier months of a year showed higher achievement in the tournaments.

Taguchi‐Grey and ANOVA optimization techniques for engine performance with water in diesel emulsion fuels

AbstractIn the current study, optimization of the performance parameters like effective power (EP), effective power density (EPD), effective efficiency (EE), and different heat losses with respect to six engine control parameters, that is, emulsion fuel, compression ratio, equivalence ratio, engine speed, residual gas fraction, and fuel injection pressure with three levels of each, were performed. Taguchi method is used to design the L27 orthogonal array, using Minitab17 software. Optimization of individual performance parameters is performed with the signal to noise ratio curve, and Grey analysis is used to optimize the overall output performance parameters. Furthermore, an analysis of variance method is investigated to calculate the contribution percentage of control parameters. The theoretical analysis revealed that the overall optimum response of output parameters is found with 10% blend of water (A3), 18 compression ratio (B3), 0.8 equivalence ratio (C1), 2100 rpm engine speed (D3), 10% residual gas fraction (E3), and 100 kPa fuel injection pressure (F1). The EP and EPD are improved by 9.6% and 9.19%, respectively. Also, an average GRG for optimum response setting coincides with the average GRG value of the initial setting. The resulted optimization models are anticipated to be positive instruction for diesel engine operating parameters.

Performance evaluations of a shrouded contra-rotating rotor based on a novel-designed platform with multiple testing possibilities

This paper aims to design a novel experimental platform with multiple testing possibilities on different individual performance parameters and different rotary propulsion systems. Three mechanic swingarms were constructed to separately and simultaneously test the rotor(s) and shroud, so that the interactions among different components can be involved. Based on it, measurements on the total thrust, torque, and power were conducted to evaluate the system global performance and the effects of key design parameters. The test results indicate that the performance parameters such as total thrust, torque, power, and power loading of the shrouded double rotor (SDR) are asymmetric between the current system and the one with switched rotational speed. Compared with free rotors, the shroud presence can increase the total thrust by 61.2% and power loading by 60%; the combination of divergent nozzle and, relatively, great inlet can improve the system performance, but it is limited by the flow separation; the system behaves insensitively to the rotor locations and rotor number. The location at the upstream cylindrical section is recommended; the optimal performance usually occurs under the condition of the upstream rotational speed lower than the downstream one. All revealed phenomena and the effectively designed test platform give the technique references for the shrouded system design and optimization.

Comparative analysis of line-start permanent magnet synchronous motor and squirrel cage induction motor under customary power quality indices

Super premium efficiency (IE4) line-start permanent magnet synchronous motor (LSPMSM) is one of the good alternatives to the squirrel cage induction motor (SCIM), especially for a line-start application. Motor performance parameters like efficiency, input power consumption, power factor, starting behavior and torque ripple are affected primarily because of the customary power quality indices. The problems originate due to furnaces, power electronic converters, nonlinear loads, digital controllers, modern electrical equipments and lively load variations. Hence, the performance analysis of LSPMSM and SCIM is essential to understand the motor behavior. Voltage harmonic distortion, voltage unbalance factor and long-duration voltage variation are considered in this study. Customary power quality indices (CPQI) are collected using power and energy analyzer in a sugar industry at various measured points. In the present study, 2.2 kW LSPMSM is designed and prototyped for constant load operation. The designed motor and SCIM are used for analyzing the performance using finite element analysis under the influence of measured CPQI and the effects on its individual performance parameters.

Keep Your Head Up-Correlation between Visual Exploration Frequency, Passing Percentage and Turnover Rate in Elite Football Midfielders.

Statistical analysis of real in-game situations plays an increasing role in talent identification and player recruitment across team sports. Recently, visual exploration frequency (VEF) in football has been discussed as being one of the important performance-determining parameters. However, until now, VEF has been studied almost exclusively in laboratory settings. Moreover, the VEF of individuals has not been correlated with performance parameters in a statistically significant number of top-level players. Thus, the objective of the present study was to examine the relationship between VEF and individual performance parameters in elite football midfielders. Thirty-five midfielders participating in the Euro 2016 championship were analyzed using game video. Their VEF was categorized into scans, transition scans, and total scans. Linear regression analysis was used to correlate the three different VEF parameters with the passing percentage and the turnover rate for individual players. The linear regression showed significant positive correlations between scan rate (p = 0.033, = 3.0%) and total scan rate (p = 0.015, = 4.0%) and passing percentage but not between transition scan rate and passing percentage (p = 0.074). There was a significant negative correlation between transition scan rate and turnover rate (p = 0.023, = 3.5%) but not between total scan rate (p = 0.857) or scan rate (p = 0.817) and turnover rate. In conclusion, the present study shows that players with a higher VEF may complete more passes and cause fewer turnovers. VEF explains up to 4% of variance in pass completion and turnover rate and thus should be considered as one of the factors that can help to evaluate players and identify talents as well as to tailor training interventions to the needs of midfielders up to the highest level of professional football.

Application of Customizable Robot Assistance Systems to Compensate Age-Related Restrictions of the Musculoskeletal System for Assembly Workplaces

Due to the demographic change, hybrid work systems increasingly gain importance. Especially, robot based assistance systems show potential to respond individually to employee’s performance parameters. Existing technologies offer possibilities to capture individual performance parameters which can be transferred into a digital environment. Identified impairments, e.g. of the musculoskeletal system, can be used to design an individual work environment with human-robot collaboration that fits the employee’s needs to guarantee a low risk of physical harm due to work related strain. Following the employee’s capabilities, the simulation reveals stressful activities that can be transferred to the robot. Thus, the work system offers the opportunity to individually respond to the employee and the given tasks by creating a work situation that suits the employee’s preconditions. This paper presents an approach for capturing individual physical performance parameters in form of movement restrictions by a motion capturing system without markers and the transmission of the motion data into a digital human model. It will be shown how the simulation can be used to design a needs-based work place by integration of a robot based assistance system.

중소형 무인항공기 개념설계를 위한 형상 및 성능 분석

개념설계는 복합시스템인 무인기의 성공적인 개발을 위해 가장 중요한 단계로써 간단한 성능해석과 형상설계가 수행된다. 개념설계 단계에서의 성능해석은 복잡한 해석도구를 사용하기 보다는 주로 경험식이나 통계적 데이터를 이용한 추세방정식을 사용한다. 무인기의 형상은 매우 다양하여 개념설계 단계에서 이러한 모든 항공기 형상을 고려하기에는 어려움이 있다. 본 연구에서는 무인기 개념설계를 위해 주요 성능변수에 대한 추세방정식을 도출하였고, 자주 사용되는 형상 선정을 위해 최대이륙중량 50-1,500kg 급의 중소형 무인기에 대한 데이터베이스를 구축하였다. 또한 주요 성능변수들에 대한 파라미터 분석을 수행하였으며, 이들 성능변수에 대한 상관도 분석결과에 따라 높은 상관도를 보이는 최대이륙중량과 날개폭을 기준으로 각 성능요소별 회귀분석을 수행하여 추세방정식을 도출하였다. The simplified performance analysis and initial configuration design are required for the successful development of UAV during the conceptual design, in which empirical formulas and trend equations are utilized for the UAV performance analysis. In the conceptual design phase various UAV configurations may be considered, however, it is very inefficient and unnecessary to consider all configurations for the conceptual design. In this study, the database for the fixed wing UAVs whose MTOW is between 50kg and 1,500kg was also constructed for the selection of configuration frequently used. The parametric analyses were performed for major performance parameters, and trend equations were developed through regression analyses for these individual performance parameters.

Kundenzufriedenheit, Dienstleistungsqualität und die Bedeutung einzelner Leistungsparameter: Das Beispiel des Lindner Congress Hotels Cottbus

Zusammenfassung In diesem Beitrag wird die Kundenzufriedenheit und die Dienstleistungsqualität zur Beurteilung des Leistungsangebots von Hotels, hier für das Lindner Congress Hotel Cottbus, untersucht. Hierfür wird einerseits der bewahrte SERVQUAL-Ansatz zugrunde gelegt und auf hotelspezifische Fragestellungen übertragen. Andererseits wird die Bedeutung einzelner Leistungsparameter über die Abfrage ihrer indirekten Wichtigkeit ergänzend erhoben und analysiert. Die Ergebnisse verdeutlichen neben der prinzipiellen Verwendbarkeit des SERVQUAL- Ansatzes und der indirekten Leistungsparametermessung, dass die Gäste des Lindner Congress Hotels Cottbus mit den für 4-Sterne-Hotels typischen Leistungsparametern zufrieden sind.

Steady State Performance of a Single Phase Natural Circulation Loop With End Heat Exchangers

In the present investigation, the steady state performance of a rectangular single phase natural circulation loop (NCL) with end heat exchangers is studied. One-dimensional governing equations are considered in developing the mathematical model. Analytical expressions are derived for the circulation rate and temperature profile. However, the individual performance parameters are to be computed iteratively as the equations are strongly coupled. A suitable iterative procedure is given to evaluate the important loop parameters such as steady state flow rate, and riser and downcomer temperatures. Few special cases are discussed where analytical expressions for circulation rate and temperature distribution can be obtained directly without any iterative procedure. It is also shown that both the hot and cold end heat exchangers should have equal conductance (UA) for maximization of circulation rate. This feature of NCL is identical with heat power cycle and can be explained in light of equipartition principle.

26. Exploring the limits of performance of third generation image intensifiers

A large number of papers have been written which describe various aspects of the GaAs photocathode, but very little has been published on the application of GaAs to image intensifiers. The little that has been published suggests that GaAs photocathode image intensifiers (third generation) will prove a significant improvement on existing tubes. The published data does very little to indicate whether the third generation has reached the limits of development or whether further improvements can be anticipated. This paper draws together the relevant published experimental and theoretical data and compares this with new experimental data from current developmental samples of third generation intensifiers. The main tube parameters, sensitivity, resolution, noise and life are examined in turn against this background information in an attempt to define the known physical and technological limitations to performance. This paper therefore explores the upper limits of the individual performance parameters of the third generation wafer tube, and explains some of the trade-offs between the various parameters. Finally, the limiting performance is compared with existing second and third generation devices, in an attempt to fit the third generation image intensifier into the general night vision background.

Performance requirements for the transmission of the PAL coded signal

The principles used to derive the existing performance requirements for the transmission of the PAL colour signals used in the UK, as embodied in a CCIR Recommendation, are briefly reviewed, and the need to relate objective performance figures to the corresponding subjective effects is pointed out. An account is given of the changes proposed in a new CCIR Draft Recommendation that gives unified methods of measurement and performance requirements for international connections which, at different times, may carry colour-television signals to any of the PAL, SECAM or NTSC standards. It is shown that although some of the new proposals are somewhat different in form, they are neither significantly more nor significantly less stringent than the existing require ments for System I. Progress in the related field of subjective studies is also reviewed, and the available results relating to PAL colour television are collated and expressed in terms which seem likely to become an international standard. Another imortant feature affecting the operation of a television network is the effect of variability of the individual performance parameters on the overall quality of service. Some preliminary work in this area, which produced unexpected results, is reviewed and its significance in the overall design of television networks is discussed.

Designing for reliability

A mathematical model is presented which will enable the designer of electronic equipment to compute its survival probability. Thus, he can make the engineering decision on whether or not the equipment meets its reliability specification. Although only electronic circuits are discussed here, the model is equally applicable to mechanical and electrical systems. In the model the performance parameters (gain, power output, bandwidth, etc.) are expressed as a function of the individual components of the circuit. The statistical distributions of the component characteristics (dependent on both operating time and environment) are then used in conjunction with the circuit equations to yield a simplified expression for the circuit survival probability. This simplification involves an approximation method using the multivariate Gram-Charlier expansion. These methods are applicable even if the component characteristics are correlated and are described by any probability density function. The fact that individual performance parameters may be correlated is taken into account automatically.