Relative Performance Capabilities Research Articles

Habitat features and performance interact to determine the outcomes of terrestrial predator-prey pursuits.

Animals are responsive to predation risk, often seeking safer habitats at the cost of foraging rewards. Although previous research has examined how habitat features affect detection by predators, little is known about how the interaction of habitat features, sensory cues and physical performance capabilities affect prey escape performance once detected. To investigate how specific habitat features affect predation risk, we developed an individual-based model of terrestrial predator-prey pursuits in habitats with programmable features. We ran simulations varying the relative performance capabilities of predator and prey as well as the availability and abundance of refuges and obstacles in the habitat. Prey were more likely to avoid detection in complex habitats containing a higher abundance of obstacles; however, if detected, prey escape probability was dependent on both the abundance of refuges and obstacles and the predator's relative performance capabilities. Our model accurately predicted the relative escape success for impala escaping from cheetah in open savanna versus acacia thicket habitat, though escape success was consistently underestimated. Our model provides a mechanistic explanation for the differential effects of habitat on survival for different predator-prey pairs. Its flexible nature means that our model can be refined to simulate specific systems and could have applications towards management programmes for species threatened by habitat loss and predation.

Semi-active suspension systems from research to mass-market – A review

It is well documented that active suspension systems offer substantial benefits in ride comfort, handling control over traditional passive systems. However, restrictive features such as the power required and costs make an active system impractical. To solve those problems, semi-active suspension systems have been developed. This paper aims at providing a review of the present state-of-the-art in the semi-active suspension control field in terms of vehicle ride comfort and road-holding performance evaluation. Strengths and weaknesses of the semi-active suspension systems are identified and their relative performance capabilities and equipment requirements are discussed. Furthermore, examples of the current mass market implementation for semi-active suspension systems for road vehicle are discussed.

Benchmarking of Undergraduate Computing Curricula in Kenya

This study investigated the quality of undergraduate computing curricula at Kenyan universities, how they compare locally and regionally with equivalent programs and how closely they meet the ICT sector needs. It was guided by four objectives i.e. to undertake an ontological mapping of computing curricula, to identify appropriate benchmarking criteria, to develop and test a benchmarking tool, and to investigate the alignment of these curricula to computing skills requirement. The study was deemed important by the plethora of academic computing programs of varying degrees of utility and credibility, which are a product of the escalating demand for computing education in Kenya given the development of Vision 2030 and the rapid growth of the ICT industry. To achieve its objectives, the study adopted a quantitative and qualitative cross-sectional descriptive survey of computing curricula offered locally (in Kenya) and regionally (from best practicing countries, USA and India). A sample of 70.3% was drawn from the target population for ontological mapping. Two research instruments, i.e. a questionnaire and a document analysis framework that were administered to a cross-section of 11 public/private universities. The study established that there are 24 undergraduate computing programs under 6 titles, viz. BSc., BCom., BTech., BB., BEd. and BEng. The two most populous programs are BSc. Computer Science (CS) and BSc. Information Technology (IT), which were selected to help identify two benchmarking criteria: Percent weight allocation of core hours within ACM knowledge areas and Relative performance capabilities of computing graduates. Using these criteria a benchmarking tool was developed and tested, which depicted disparities among the respondents in the percent weight allocation of core hours in CS programs. Similarly, it portrayed overlaps in the relative performance capabilities of CS and IT graduates, an outcome that queried the uniqueness of these programs. As such, its results indicate that the quality of the two computing programs is relatively insufficient. However, it further establishes that the computing curricula are aligned to meet the top 3 highly demanded computing skills i.e. Networking, Software development and Internet skills albeit insufficient percent weight allocation of core hours in Software development. It therefore recommends further testing and refining of the established benchmarking tool, the need to re-focus the computing programs and supports the call to institute a regulatory body and qualifications framework for computing education and skills.Â

Reliability of Crack Detection Methods for Baseline Condition Assessments

Despite billions of dollars of annual exposure from claims and litigation related to construction-induced damage, there are no quantitatively based, agreed upon standards or procedures as to what constitutes due diligence with respect to a preconstruction, condition assessment. Similarly, the relative accuracy, reliability, and costs for various inspection approaches are not well established. This paper compares the relative performance capabilities of crack detection by sidewalk-based manual inspection with digital photography, terrestrial Light Detection and Ranging (LiDAR), and elevated manual inspections based on two brick and two concrete buildings (8.2–14.3 m high) in Dublin, Ireland. Results showed that nonmanual methods tended to overpredict crack widths by at least 5 mm and underestimate crack lengths by one-half. Digital photography, however, detected the shortest cracks (as short as 17 mm) and had no significant decline in accuracy beyond 12 m high, which has the added benefit of generating a p...

Fast RLS Fourier analyzers capable of accommodating frequency mismatch

Adaptive Fourier analyzers are used to estimate the discrete Fourier coefficients (DFC) of sine and cosine terms of noisy sinusoidal signals whose frequencies are usually assumed known a prior. The recursive least squares (RLS) Fourier analyzer provides excellent performance, but is computationally very intensive. In this paper, we first present four fast RLS (FRLS) algorithms based on the inherent characteristics of the DFC estimation problem. These FRLS algorithms show approximately the same performance and indicate estimation capabilities that are quite similar to those of the RLS, while requiring considerably less computational cost. Second, the performance of the proposed FRLS algorithms is analyzed in detail. Difference equations governing their dynamics as well as closed-form expressions for their steady-state mean square errors (MSE) are derived and compared with those of the LMS Fourier analyzer. Third, the RLS and four FRLS algorithms are modified by incorporating an adaptive scheme, to alleviate the influence of undesirable frequency mismatch (FM) on their performance. Extensive simulations as well as application to real noise signals are provided to demonstrate the relative performance capabilities of the RLS and four FRLS algorithms, the validity of analytical findings, and ability of the modified RLS and FRLS algorithms to mitigate the influence of the FM.

Effect of suspension spring stiffness on vehicle dynamics

Vehicle suspension systems and suspension working space are of great interest to designers and researchers of road vehicles. This paper deals with an investigation into the influence of suspension spring stiffness on vehicle dynamics. A mathematical model of a quarter vehicle for twin spring, passive and active suspension systems is developed. These systems are compared in terms of their relative performance capabilities. The vehicle itself is treated as a rigid body undergoing vertical motions. Also, a longitudinal half vehicle model for passive suspension is used to investigate the effect of front and rear spring stiffness on the vehicle dynamics. A chassis dynamometer was used to perform the experimental work. The predicted results were compared with experimental measurements. The experimental and theoretical results obtained indicate that the mathematical model produces optimistic results for the vertical direction of body acceleration and suspension working space. The effect of using active suspension elements to obtain improved ride is discussed. The results obtained give a solution to the vehicle dynamics problem and show optimum values of spring stiffness and damping coefficient.

Skin adhesives and skin adhesion: 1. Transdermal drug delivery systems

The use of pressure-sensitive adhesives (PSAs) for skin-contact applications is discussed. The requirements of such adhesives in various applications are examined in detail. Commercially available classes of PSAs used for skin-contact applications are the acrylics, the polyisobutylenes, and the silicones. The main application examined in this review is transdermal drug delivery. The roles played by the PSA in two types of transdermal designs are described. Correlations between in vivo and ex vivo measurements of adhesion are discussed. Also, the reported human studies of various commercially available transdermals are examined critically, with a view to assessing the relative performance capabilities of each type of transdermal design. Finally, a comprehensive listing of currently commercialized transdermals is given.

Power losses in active and passive suspensions of off-road vehicles

Various types of controlled suspension systems are compared in terms of their relative performance capabilities and power requirements. In addition to any direct inputs required at the actuator, the total power dissipations within the suspensions are calculated. This power must ultimately be provided by the vehicle's power unit and it typically between 10 and 20% of the power losses involved in rolling resistance. The mean power dissipation levels are found to be similar for all the types of suspension compared. However, the detailed way in which this power is dissipated differs and accounts for the significantly different performance levels available from each suspension.

Road Vehicle Suspension System Design - a review

SUMMARY Based mainly on English language literature, information relating to the design of automobile suspension systems for ride comfort and control of wheel load variations for frequencies below body structure resonances is reviewed. The information is interpreted in the context of vehicles which travel through a wide speed range on roads of markedly differing quality, which do so carrying different loads and which are required to possess good handling qualities. Sections are devoted to describing road surfaces, modelling vehicles and setting up performance criteria, and to passive, active, semi-active and slow-active system types. Methods for deriving active system control laws are outlined. Strengths and weaknesses of the various systems are identified and their relative performance capabilities and equipment requirements are discussed. Attention is given to adaptation of the suspension or control system parameters to changing conditions. Remaining research needs are considered.

The Relative Performance Capabilities of Passive, Active and Semi-Active Car Suspension Systems

Based on the well-known quarter car representation of the automobile suspension design problem, pdomnce parameters relating to passenger discomfort, working space and tyre load variability are generated for passive, active and semi-active suspension systems. Active systems of two types having different hardware implications are considered, and linear optimal control theory is used in each case to derive a good set o control law parameters. The semi-active systems studied have control laws based on the fully active systems, but are capable only of dissipating energy, so that where the corresponding active system would be acting as an energy supply, the semi-active system switches off Practically realizable switching dynamics are assumed in the calculations. Results for all the systems, for one road surface roughness and vehicle speed, are generated in a form which allows comparison between systems of diffient types which have equal suspension working space requirements. The wider implications of the results are discussed, and far-reaching conclusions about the relative capabilities and design features of passive, active and semi-active systems are drawn.

Selection of modulation code parameters for maximum lineal density

The relative performance capabilities for many known run-length-limited binary modulation codes useful in digital magnetic recording are placed in perspective. The criteria for grading is relative maximum achievable lineal recording density under conditions of quasi-optimal spectral shaping. The results are based upon a linear system analysis in which superposition is applicable in modeling saturation recording systems where the media is indeed fully saturated at the termination of each transition. The maximum relative achievable lineal density is shown in terms of code parameters for maximum theoretical information rate with run constraints. The results show which binary modulation code to select for maximal lineal density and how its performance compares with the maximum theoretically achievable for any binary modulation code.