Performance Attributes Research Articles

Power Generation Performance Indicators of Wind Farms Including the Influence of Wind Energy Resource Differences

The accurate evaluation and fair comparison of wind farms power generation performance is of great significance to the technical transformation and operation and maintenance management of wind farms. However, problems exist in the evaluation indicator systems such as confusion, coupling and broadness, and the influence of wind energy resource differences not being able to be effectively eliminated, which makes it difficult to achieve the fair comparison of power generation performance among different wind farms. Thus, the evaluation indicator system and comprehensive evaluation method of wind farm power generation performance, including the influence of wind energy resource differences, are proposed in this paper to address the problems above, to which some new concepts such as resource conditions, ideal performance, reachable performance, actual performance, and performance loss are introduced in the proposed indicator system; the combination of statistical and comparative indicators are adopted to realize the quantitative evaluation, indicator decoupling, fair comparison, and loss attribution of wind farm power generation performance. The proposed comprehensive evaluation method is based on improved CRITIC (Criteria Importance though Intercrieria Correlation) weighting method, in which the uneven situation of different evaluation indicators and the comprehensive comparison of power generation performance among different wind farms shall be overcome and realized. Several sets of data from Chinese wind farms in service are used to validate the effectiveness and applicability of the proposed method by taking the comprehensive evaluation models based on CRITIC weighting method and entropy weighting method as the benchmarks. The results demonstrated that the proposed evaluation indicator system works in the quantitative evaluation and fair comparison of wind farm design, operation, and maintenance and traces the source of power generation performance loss. In addition, the results of the proposed comprehensive evaluation model are more in line with the actual power generation performance of wind farms and can be applied to the comprehensive evaluation and comparison of power generation performance of different wind farms.

Evaluation of water deficit tolerance in maize genotypes using biochemical, physio-morphological changes and yield traits as multivariate cluster analysis

Drought is an abiotic stress that inhibits plant growth and development and, therefore, declines crop productivity, as seen in maize plant. The aim of this investigation was to identify the candidate maize varieties that can be grown under water limited conditions using physio-morphological and yield attributes. Eight genotypes of maize including ‘Suwan4452’ (drought tolerant) as a positive check, ‘CP301’, ‘CP-DK888’, ‘DK7979’, ‘DK9901’, ‘Pac339’, ‘S7328’, and ‘Suwan5’ were selected as test plants. Physiological, biochemical and morphological characteristics at seedling (24 day after sowing; DAS) and reproductive (80 DAS) developmental stages of plants under 20-day water withholding (WD), and yield traits at harvesting period were analysed. Leaf temperature in each genotype increased with the degree of water deficit stress, leading to leaf chlorosis, and reduction in maximum quantum yield of PSII (Fv/Fm), photon yield of PSII (ΦPSII), net photosynthetic rate (Pn), overall growth and yield. Pn and stomatal conductance (gs) in drought tolerant genotype, ‘Suwan4452’, were decreased by 19.1% and 18.6%, respectively, whereas these in drought sensitive, ‘Pac339’, were significantly declined by 53.9% and 61.8%, respectively. Physio-morphological parameters, growth performance and yield-related traits of maize genotypes grown under water deficit conditions and well-watered conditions were subjected to Ward’s cluster method for identification of water deficit tolerant cultivars. Maintaining photosynthetic abilities, osmotic adjustment and CWSI in drought tolerant genotypes of maize were evidently demonstrated to keep overall growth performance and yield attributes. Based on multivariate cluster analysis and PCA (principal component analysis), ‘Suwan4452’, ‘CP-DK888’ and ‘S7328’ were categorized as drought tolerant genotypes whereas ‘Suwan5’, ‘Pac339’, ‘DK7979’, ‘CP301’ and ‘DK9901’ were identified as drought susceptible cultivars. Hybrid maize cvs. ‘CP-DK888’ and ‘S7328’ may further be suggested to be grown in the rainfed area without irrigation.

End-of-Use vs. End-of-Life: When Do Consumer Electronics Become Waste?

This study focuses on the lifespan of consumer electronics. The article reviews end-of-life terminology in scientific literature and suggests distinguishing end-of-use and end-of-life stages. The question, when electronics become waste, is approached using the concept of a system called PSSP language, which classifies artefacts based on their attributes of purpose, structure, state and performance. It is highlighted that waste as a concept is dynamic; the same thing can be waste or non-waste at different times and places and for different people. Further, the article reviews the impact of storage behavior on the realization of the waste hierarchy, using mobile phones as a case study. Evidence suggests that over half of customers use their mobile phones for only two years, and there is little incentive to keep them in use longer. Surveys also indicate that over half of the customers do not return their phones for reuse or recycling but keep them at home. The article suggests that the three key factors, promoting the storing of an old phone, are the shortness of usage time, perceived residual value of replaced equipment and concerns of personal information security. It is also indicated that memories and the personal attachment to the device contribute to consumers’ storage decision. It is concluded that, to prolong the use of mobile phones, there is a demand for changing consumers attitudes towards the return of electronics for reuse and repair to be more positive.

Electronic Integrated Disease Early Warning System Surveillance System Evaluation, Sana'a Capital, Yemen, 2021

Background The Electronic Integrated Disease Early Warning System (eIDEWS) is an essential system; it contributes to the better prevention and management of epidemics. Through the collection of complete, accurate, and timely data, countries are able to determine the priorities for suitable interventions that save the lives of communities. Regardless of the conflict in Yemen, the system is still functioning and is expanding to be the most effective epidemiological surveillance program. Objective We aimed to determine the usefulness of the eIDEWS, assess its performance, and identify the strengths and weaknesses of its implementation. Methods The usefulness and performance attributes of the eIDEWS were evaluated using the Centers for Disease Control and Prevention’s updated guidelines for evaluating public health surveillance systems. The evaluation was carried out in Sana’a capital from January to March 2021 by interviewing 25 stakeholders at 3 levels—the central, governorate, and health district levels—and using a semistructured questionnaire. Attributes of the system were ranked as poor (<60%), average (60% to <80%), good (80% to <90%), and excellent (≥90%) on the basis of indicators to calculate the final scores. Results The eIDEWS’ overall usefulness and performance score was 90%—an excellent rank. The mean score of system attributes was 100% for acceptability, completeness, and timeliness. The flexibility was good (83%), since the change in reporting method was applied difficultly. The system depends completely on foreign funds; thus, the system’s stability was average (75%). However, the eIDEWS was expanded recently to add new health facilities; its representativeness was average (76%). Conclusions The system is working effectively at evaluated sites. The overall system performance was excellent; however, flexibility and stability were good due to the negative adaptation of the system with regard to the reporting method and the absence of other fund resources. Therefore, evaluating the newly upgraded system, strengthening its stability by finding other supporting resources, and further expanding coverage to include all public and private health care facilities are recommended.

Reducing transaction costs for interest rate risk hedging with stochastic programming

Traditional methods for hedging interest rate risk do not take transaction costs into account as they aim to eliminate all risk. We propose a two-stage stochastic programming model for hedging interest rate risk where transaction costs are weighed against portfolio variance. High-quality measurements of term structures enable us to extract the systematic risk factors and make precise estimates of the perceived transaction costs. The hedging cost is weighed against the reduction in portfolio variance by using an adjustable hedging parameter. The hedging procedure is simulated on a daily basis in a realistic setting over an out-of-sample period from 2002 to 2018, and the results are compared to traditional hedging methods through detailed performance attribution. Using second-order stochastic dominance, we show that the proposed method is preferred by all risk-averse investors.

Towards an information-theoretic framework of intrusion detection for composed systems and robustness analyses

Network-based Intrusion Detection Systems (NIDSs) are an important mechanism to identify malicious behaviour or policy violations within a network. Such detection systems typically face several challenges, among which are the base-rate fallacy and the resilience against adaptive adversaries. These challenges are often countered in modern NIDSs by combining multiple detection systems to diversify the used feature levels or utilize the advantages of multiple detection methods. However, currently there exists no suitable framework for a detailed analysis of such composed systems. Therefore, the contribution of this work is an evaluation framework for composed systems, which builds on previous information-theoretic approaches and highlights the utility of information-theoretic redundancies for robustness evaluations. This framework enables an attribution of the overall system performance to its individual components, to fine-tune parameters and to study the dynamics between classifiers. The versatility of the framework is demonstrated by designing and evaluating a composed NIDS example based on systems described in the literature and using an open data set. Studying the impact of an evasion attempt with adversarial examples on this system highlighted the importance of robustness against false-alarms as well as detection evasion. Moreover, the framework enables general insights on how to improve the design of composed NIDSs: based on the dynamics between classifiers, it can be shown that optimizing the operation point of each component individually does not necessarily maximize the overall system performance from an information-theoretic perspective. Additionally, it can be shown that existing classification redundancies might not be fully utilized during an attack on the NIDS components, due to a static system design.

Postoccupancy Evaluation for Student Housing with a Focus on Maintenance Planning, Design Process, and Client Requirement

The improvement of facility maintenance and operation practices for constructed buildings is a major concern for all facility management (FM) firms worldwide. The owner, planner, and developer of housing projects, especially projects that are repeated, are eager to enhance the quality of the coming projects based on satisfaction of the current facility occupants. Little research has been conducted to link occupants’ requirements and satisfaction with FM practices or with the design of future facilities. The main purpose of this research was to determine students’ satisfaction with and obtain their qualitative feedback regarding a hostel facility to determine whether the constructed facility is providing the performance needed by users of the facility. The research also evaluated the housing facility from the occupants’ perspective and correlated this with the current maintenance practices to improve the maintenance planning and the overall performance of the facility. A survey covering 56 different performance attributes was conducted using a questionnaire distributed to the students. The overall level of satisfaction with the studied attributes indicated that the students generally were satisfied with the housing facility. This study will enable the maintenance administration and the university management to identify areas of students’ dissatisfaction with housing facility, which will help to improve the performance and the overall satisfaction. Thus, the results and findings from this study will keep the quality of future constructed students housing up to the desired standards and level of service. The study contributes to the body of knowledge on improving student accommodation in higher education and provides valuable insight to the facility management.

Chevon production and quality of Kalahari Red goats fed increasing levels of hempseed cake substituted for soybean meal

A 42-d study was conducted to evaluate the effects of replacing soybean meal with increasing levels of hempseed cake (HSC) in goat finishing diets on growth performance, carcass and chevon quality attributes. Thirty-five, 3-month-old Kalahari Red wethers (25 ± 1.5 kg initial body weight) were randomly allocated to one of five dietary treatments with seven animals per treatment. Wethers were fed maize-lucerne based finishing diets with inclusions of 0 (control), 25, 50, 75 and 100 g/kg DM of HSC replacing soybean meal as the main protein source. Diet had no effect (P > 0.05) on daily feed intake, average daily gain, final body weight and income-over-feed costs. Carcass and meat quality attributes were not influenced (P > 0.05) by HSC, except intramuscular fat, which increased linearly (P ≤ 0.05) with HSC inclusion levels. It was concluded that HSC could completely replace soybean meal in goat finishing diets without affecting chevon production and quality.

Performance and environmental impact of egg production in response to dietary supplementation of mannan oligosaccharide in laying hens: a meta-analysis

A meta-analysis was conducted to examine the effect of supplementing mannan oligosaccharide (MOS; Bio-Mos, Alltech Inc., Nicholasville, KY) in the diets of laying hens on the performance and environmental impact of egg production. Data on production performance (feed intake, hen-day production [HDP], feed conversion ratio [FCR], and mortality) and egg quality attributes (egg weight, egg mass, and eggshell thickness) were extracted from 18 studies to build a database of comparisons between nonsupplemented diets (control) and diets supplemented with MOS. A total of 4,664 laying hens were involved in the comparisons and the average MOS dosage and age of hens were 0.97 kg/ton and 44 wk, respectively. The dataset was analyzed using the random-effects model to estimate the effect size of MOS supplementation on production performance and egg quality attributes. The impact of feeding MOS on the carbon footprint (feed and total emission intensities) of egg production was evaluated by using the meta-analysis results of production performance to develop a scenario simulation that was analyzed by a life cycle assessment (LCA) model. Overall pooled effect size (raw mean difference) indicated that MOS supplementation did not affect feed intake. In contrast, HDP increased by +1.76% and, FCR and mortality reduced by −26.64 g feed/kg egg and −2.39%, respectively. Dietary MOS did not influence egg weight while egg mass increased (P < 0.01) by +0.95 g/day/hen and eggshell thickness tended to increase (P = 0.07) by +0.05 mm. Subgroup analysis indicated that dietary MOS exhibited consistent improvement on HDP and FCR under several study factors (age of hens, number of hens, production challenges, MOS dosage, and study duration). Additionally, the simulated LCA revealed that supplementing MOS decreased feed and total emission intensities of egg production by −1.3 and −1.5%, respectively. Overall, dietary supplementation of MOS at 1.0 kg/ton improved the production performance of laying hens and reduced the carbon footprint and, therefore, can enhance the sustainability credentials of egg production.

ANALISIS TINGKAT KEPENTINGAN DAN KINERJA PELAYANAN KEDAI KOPI KETJE DAN LOKAL COFFEE DI KOTA METRO

The increased number of coffee shops has led to increasingly fierce competition. A coffee shop needs to provide the best service so customers are satisfied if the performance of service attributes are considered important according to customer expectations. This study aimed to identify service attributes of coffee shops based on their importance and performance and analyze service attributes need to be maintained and improved their performance. There were two coffee shops studied, Kopi Ketje (KK) and Local Coffee (LC) were located in Metro City, Lampung Province. Data collection was carried out in August-September 2020. The number of samples for each shop was 35 respondents with total sample was 70 respondents. The sampling technique was carried out in stages. The day and time of interview was set intentionally. A sample was selected randomly based on table numbers. Attributes of importance and performance were measured on a likert scale using questionnaire. The questionnaire with 25 Attribute of importance and satisfaction has been valid and reliable. Data were analyzed using Importance Performance Analysis (IPA) method. The results showed there were 15 attributes in KK and 13 attributes in LC which considered important by respondents. The results of this study indicated 9 attributes in KK and 7 attributes in LC which are considered satisfactory. Attributes that need to be maintained were 9 attributes in KK and 7 attributes in LC. Performance attributes that need to be improved were 6 attributes in each shop.

Self‐organization's responses to the COVID‐19 pandemic in China

AbstractSelf‐organization was a key informal channel used to fight COVID‐19 in Wuhan when the local government and other formal organizations failed to respond in the very early stages of the pandemic. The present study aims to investigate the effectiveness of self‐organization during an emergency from both a demand‐driven and a social mission identity perspective. Using 14 cases, this study examines the lifecycles of self‐organization in alignment with the consistent changes in social demands. Volunteers' social mission identity and a flexible organizational structure have been identified as two major attributes of the outstanding performance of self‐organization. Moreover, self‐organization demonstrates a striking feature of noncontiguous service provision with the assistance of social media. This study extends the literature on the changing roles of governments and civil society to the emergency context.

Practical Applications of Private Portfolio Attribution Analysis

In <b><i>Private Portfolio Attribution Analysis</i></b>, published in the Fall 2021 issue of <b><i>The Journal of Alternative Investments</i></b>, <b>Gregory Brown</b> and <b>Frank Ethridge</b> at the <b>University of North Carolina at Chapel Hill</b> and <b>Tyler Johnson</b> and <b>Tom Keck</b> at <b>Stepstone Group</b> address the challenges of applying portfolio performance attribution techniques to private funds. One such challenge is that private equity funds have no periodically reported returns. The authors provide a method for attributing private portfolio performance to commitment timing and sizing, geography and strategy selection, and fund selection skills. They are measured relative to a market benchmark and can be interpreted as alphas. The authors also calculate and illustrate reasonable confidence intervals for these attributes with venture capital and buyout cash flow data. The factors explain how managers’ strategic and tactical allocation decisions impact performance and inform future decision making.

Event-triggered adaptive fuzzy control for automated vehicle steer-by-wire system with prescribed performance: Theoretical design and experiment implementation

Steer-by-wire (SbW) systems substitute the typical mechanical linkage between the steering wheel and the front wheel with electromechanical actuators, resulting in that the steering performance of SbW systems depends on the control of electromechanical actuators. To guarantee the transient and steady-state performance of SbW systems, this paper proposes an event-triggered adaptive fuzzy control for the SbW system subject to the unavailable steering angular velocity, the time-varying disturbance, and the limited communication resources. First, to solve the problem of uncertainty modeling and external interference, an interval type-2 fuzzy logic system (IT2 FLS) and a disturbance observer are used to approximate the unknown SbW system dynamics and disturbance, respectively. Second, considering the angular velocity of the front wheels is difficult to measure, an adaptive observer is developed to estimate the steering angular velocity. The observation error is proved by the Lyapunov theory to converge in finite time. Third, to guarantee the transient and steady-state performance of the SbW system, this paper develops an output feedback controller for the automated vehicles based on event-triggered control (ETC) and prescribed performance control (PPC). Theoretical analysis proves that the tracking error can converge to a preset range within the set time, and the communication data between the controller and the actuator is reduced. Finally, simulation and experiment verify the effectiveness and superiority of the proposed method. From the analysis of the estimation performance, the designed observer has strong adaptability, which can ensure better observation accuracy even if the system has uncertainty. From the analysis of control performance, the proposed controller can guarantee the output trajectory tracking performance attributes (maximum overshoot, convergence time, maximum steady-state error). More specifically, in the experiment, the tracking error can converge to within 0.075 rad in 5 s. Additionally, the RMSE of the experimental results of the designed method is 44.7% higher than that of the output-feedback adaptive neural controller. From the perspective of communication data, the control signal transmitted to the motor driver is effectively saved by 19.3 %.

Performance attribution, time-weighted rate of return, and clean finite change sensitivity index

Performance attribution, time-weighted rate of return, and clean finite change sensitivity index

Physiological and Performance Correlates of Squash Physical Performance.

The physiological and performance attributes of elite squash players were investigated. Thirty-one players (21 males, world ranking [WR] 42-594; 10 females, WR 7-182) completed a battery of fitness tests which included an aerobic squash-specific physical performance test (SPPT), repeated-sprint ability (RSA), change-of-direction speed (COD), acceleration (5-m sprint), body composition and force development (countermovement jump) assessments. The SPPT provided a finishing lap score, V̇O2max, average movement economy and the lap corresponding to a blood lactate concentration of 4 mM.L-1. Players were ranked and assigned to HIGH or LOW performance tiers. Two-way ANOVA (performance level*sex) revealed higher ranked players performed better (p < 0.05) for SPPT final lap (d = 0.35), 4 mM.L-1 lap (d = 0.52) and COD (d = 0.60). SPPT displayed a 'very-large' correlation with 4 mM.L-1 lap (r = 0.86), 'large' correlations with COD (r = 0.79), RSA (r = 0.79), sum-of-7 skinfolds (r = 0.71) and V̇O2max (r = 0.69), and a 'trivial' correlation with average movement economy (r = 0.02). Assessments of cardiovascular fitness (i.e. 4 mM.L-1 lap), RSA, COD and body composition appear highly pertinent for performance profiling of squash players. Regular, submaximal assessment of the 4 mM.L-1 lap during the SPPT may offer a practical athlete monitoring approach for elite squash players.

H-Shaped Eight-Element Dual-Band MIMO Antenna for Sub-6 GHz 5G Smartphone Applications

The design of an eight-element H-shaped dual-band multiple-input multiple-output (MIMO) antenna system for sub-6 GHz fifth-generation (5G) smartphone applications is presented in this work. The radiating elements are designed on the side edge frame of the smartphone, placed on both sides of the main printed circuit board (PCB). Each side edge consists of four radiating elements, which ensures low mutual coupling between antenna elements. The total size of the main PCB is 150&#x00D7;75 mm², while the size of the side edge frame is 150&#x00D7;7 mm². A single antenna consists of an H-shaped radiating element fed using a 50&#x03A9; microstrip feeding line designed on the main board of the smartphone. The results show that, according to -6 dB impedance bandwidth criteria, the designed MIMO antenna radiates at two different frequency ranges within the allocated FCC 5G spectrums, i.e., 3.1-3.78 GHz and 5.43-6.21 GHz with 680 MHz and 780 MHz bandwidths, respectively. It is also observed that the antenna elements are able to provide spatial and pattern diversity for both the frequency bands. Furthermore, an isolation of &#x003E;12 dB is observed between any two given radiating elements. Various MIMO key performance parameters are evaluated, such as channel capacity (CC), envelope correlation coefficient (ECC), and diversity gain (DG). A prototype is fabricated and measured, and it is found that the measured and simulated results are in good agreement. Based on performance attributes, it can be said that the proposed MIMO system may find its application in 5G communication systems.

Grape pomace silage on growth performance, carcass, and meat quality attributes of lambs

Grape pomace is a by-product that can be ensiled and added to animal feed for a sustainable animal production. This study evaluated the effects of grape pomace silage (GPS) on the intake, performance, and carcass and meat quality of feedlot lambs. Twenty-four male lambs (21.5 ± 3.0 kg initial body weight) were distributed into pairs to four diets levels 0, 10, 20, and 30 % of GPS. The addition of grape pomace silage influenced only ether extract (EE) intake linearly without hindering consumption. The diet did not affect performance and meat quality attributes and carcass parameters, with average daily gain (ADG) of 0.235 kg d−1, feed conversion 4.299, carcass conformation 2.7, compactness index 0.25 kg cm−1, fat thickness 1.51 mm, loin eye area 13.9 cm2, pH 5.79, natural matter moisture 74.05 g 100 g−1, and crude protein (CP) 19.94 g per 100 g−1 of dry matter (DM). Grape pomace as could be used as silage in lamb diets with up to 30 % GPS, as the chemical composition of this by-product and the results indicate that GPS did not compromise performance, carcass traits, and meat quality.

Comparative Assessment of the Performance and Combustion Attributes of a Free Piston Linear Generator Fuelled with Cng and Cng-Co2

Comparative Assessment of the Performance and Combustion Attributes of a Free Piston Linear Generator Fuelled with Cng and Cng-Co2

Influence of compression ratio variation on diesel engines, performance and exhaust emission parameters devouring microalgae biodiesel blends

The diesel engine performance as well as exhaust emission attributes are influenced by different structures. Impact of compression ratio and microalgae biodiesel blending proportion in petroleum diesel on variable compression ratio diesel engine performance and exhaust emission have been investigated in this study. The five blends of microalgae have been prepared on volumetric basis adopting standard procedure. The engine is fuelled with these five blends respectively to investigate their impact on engine performance and emission attributes. The experimentation has carried out at compression ratio 15.5, 16.5, and 17. For benchmarking comparison, the obtained results have been compared to test results found using petroleum diesel as fuel. Obtained experimental results have uncovered that the engine brake thermal efficiency increases as compression ratio increases for all the microalgae biodiesel blends. The brake specific fuel consumption diminishes with rise of compression ratio for tested fuel blends. The outcomes additionally show brake specific fuel consumption stay higher for blends and increase with rise of biodiesel mixing percent contrasted with unadulterated diesel. At the point when compression ratio has expanded from 15.5 to 17.5, the hydrocarbons and carbon monoxides outflow have reduced radically and nitrogen oxides discharge increases.

Investment performance attribution of the U.S. small-size value mutual funds using Fama-French five-factor model

The purpose of this study is to get an insight into the investment performance of the U.S. small-size value mutual funds. The Fama-French five-factor model was used to perform the regression of the portfolio returns composed out of the mutual funds with the chosen investment theme, as well as the regression at the individual level for 64 analyzed mutual funds, against the model's factors. The study covers the period from January 2010 until November 2021, using monthly returns. Our findings suggest that the factors from the original three-factor models are in line with the expectations and there is no presence of the potential style drift. In addition, the operating profit factor shows the expected causality relation. However, the exposure relating to the investing factor is slightly negative and may be surprising to a certain extent, having in mind the stated value style. Investment performance attribution of the portfolio explained the portfolio returns in the relation to the factors and found out that there is a statistically significant underperformance. Positive contributors to the investment performance are, in the presented order of the importance, market premium, as well as portfolio tilt towards stocks of the companies with the strong operating profit, small-capitalization, and aggressive investing policy. Lastly, value-style tilt led to negative performance contribution because the style was out of favor.