Refining adaptive design approaches for color vision deficiency: A systematic review and taxonomy (2000–2025)

The design of FIR digital filter based on minimum mean square error criterion can be implemented via adaptive approach. An iterative algorithm is proposed in this paper to enhance the effectiveness of adaptive FIR digital filter design through adaptively obtaining optimum cost functions. This modified approach results in the best values of the cost function to reach a best fit between the FIR digital filter response and the design requirements. The adaptive design approach is used to get the weights of FIR filters in time domain broadband beamformers. An example of broadband beamforming for a 12-element arc array is illustrated to show the effectiveness of the iterative algorithm proposed in this paper.

An experiment in applying the adaptive design approach to DSS development

Abstract: Geothermal power plants are designed for optimal utilization of geothermal resource. However, geothermal fields typically undergo significant changes in resource characteristics such as pressure, temperature and steam quality over their life span. With appropriate reservoir modelling it is possible to predict the future resource characteristics of a geothermal field to a reasonable degree of accuracy. We propose a new adaptive design approach that would allow geothermal power plants to take into account the change of resource characteristics that occur over a 30-40 years time horizon based on the results of reservoir modelling. Currently, it is difficult and expensive to modify or renovate an existing plant due to space constraints, piping arrangements, transportation of machinery etc. The adaptive design approach would allow cost effective modifications in operation and equipment to adjust to changes in resource characteristics in the future. A simple model for a typical combined cycle geothermal power plant is considered as a test case for the adaptive design approach. Simulation is carried out using changes in both wellhead specific enthalpy and mass flow rate. There are four case studies presented in this paper that analysed various possible options of the hypothetical power plant depending on the changes in resource characteristics. Taking into account the results of the simulation, alternative plant designs are presented and improvements in performance are discussed. Although, the initial investment cost might go up as a consequence of adaptive design, over the life span of the plant the total benefit may be greater.

In this study, the problem of robust output tracking control is considered for a class of uncertain strict-feedback non-linear systems with any input saturation. A new design approach, called an adaptive design approach, is proposed to deal with saturated input non-linearities. The main merits of the proposed adaptive design approach can be summarised as follows. (i) It is completely unnecessary to know any information on input saturation non-linearities. (ii) By utilising the proposed adaptive design approach, the resulting control schemes will have a specially simple structure. (iii) The adaptive design approach proposed in this study is also easy to understand for the system designers, and by combining the proposed adaptive design approach with other control ones, a number of interesting results can be expected for a rather large class of dynamical systems with saturation in the actuators. Finally, a numerical example is given to illustrate the design procedure, and the corresponding simulations are also implemented to show the validity of the theoretical results.

A new adaptive circuit design approach is proposed and analyzed employing independently biased back-gated Double-Gate MOSFET (DGMOSFET) devices. Threshold voltage tuning using back-gate of the DGMOSFET was compared with a conventional body-bias method. The technique is a promising solution to control the transistor's threshold voltage while reducing undesirable effects at the sub-50-nm device technology nodes. An automatic adaptive circuit for threshold voltage tuning was implemented using DGMOSFET devices in 45 nm CMOS technology. Simulation results show that this circuit compensates for static and dynamic variations. This adaptation approach using DGMOSFETs along with adaptive supply voltage scaling allows simultaneous optimization of power and performance according to application-specific workload and requirements. Simulation results using a 45 nm CMOS technology indicate that this adaptive circuit design can provide 50% higher performance for the same energy, or consume 40% less energy for the same performance. In contrast to conventional methods which only employ dynamic voltage scaling, adaptive tuning of threshold voltages reduces power consumption while maintaining its noise margin.

An optimal sampling schedule strategy based on the Fisher information matrix and the D-optimality criterion has previously been proposed as a formal framework for optimizing inversion time scheduling for multi-inversion-time arterial spin labeling experiments. Optimal sampling schedule possesses the primary advantage of improving parameter estimation precision but requires a priori estimation of plausible parameter distributions that may not be available in all situations. An adaptive sequential design approach addresses this issue by incorporating the optimal sampling schedule strategy into an adaptive process that iteratively updates the parameter estimates and adjusts the optimal sampling schedule accordingly as data are acquired. In this study, the adaptive sequential design method was experimentally implemented with a real-time feedback scheme on a clinical MRI scanner and was tested in six normal volunteers. Adapted schedules were found to accommodate the intrinsically prolonged arterial transit times in the occipital lobe of the brain. Simulation of applying the adaptive sequential design approach on subjects with pathologically reduced perfusion was also implemented. Simulation results show that the adaptive sequential design approach is capable of incorporating pathologic parameter information into an optimal arterial spin labeling scheduling design within a clinically useful experimental time.

An optimal dynamic inversion-based neuro-adaptive approach for treatment of chronic myelogenous leukemia

This paper proposes an adaptive synthesis and design approach of narrowband bandpass filters with extracted-poles (EP). After performing only one electromagnetic simulation on the physical structure of the EP section, the corresponding equivalent circuit parameters can be extracted. The remaining filter circuit can be adjusted to adapt to the realized EP section. Then accurate mapping relationship between the physical dimensions and the synthesized prototype circuit can be established. In this paper, a five-pole rectangular waveguide filter with one finite transmission zero is designed as an example. In the novel filter synthesis procedure, a generalized equivalent circuit is proposed to process the connection between the EP structure and the adjacent resonator. Finally, the EP section, coupled resonators, and the connecting waveguide can be assembled to get the whole filter. The frequency response of the entire filter is close to the ideal one, verifying that the proposed synthesis and design approach can give high-quality initial dimensions for filter fine-tuning or optimization.

Sequential methods provide a formal framework by which clinical trial data can be monitored as they accumulate. The results from interim analyses can be used either to modify the design of the remainder of the trial or to stop the trial as soon as sufficient evidence of either the presence or absence of a treatment effect is available. The circumstances under which the trial will be stopped with a claim of superiority for the experimental treatment, must, however, be determined in advance so as to control the overall type I error rate. One approach to calculating the stopping rule is the group-sequential method. A relatively recent alternative to group-sequential approaches is the adaptive design method. This latter approach provides considerable flexibility in changes to the design of a clinical trial at an interim point. However, a criticism is that the method by which evidence from different parts of the trial is combined means that a final comparison of treatments is not based on a sufficient statistic for the treatment difference, suggesting that the method may lack power. The aim of this paper is to compare two adaptive design approaches with the group-sequential approach. We first compare the form of the stopping boundaries obtained using the different methods. We then focus on a comparison of the power of the different trials when they are designed so as to be as similar as possible. We conclude that all methods acceptably control type I error rate and power when the sample size is modified based on a variance estimate, provided no interim analysis is so small that the asymptotic properties of the test statistic no longer hold. In the latter case, the group-sequential approach is to be preferred. Provided that asymptotic assumptions hold, the adaptive design approaches control the type I error rate even if the sample size is adjusted on the basis of an estimate of the treatment effect, showing that the adaptive designs allow more modifications than the group-sequential method.

Improving the performance of a 2-stage large aperture parabolic trough solar concentrator using a secondary reflector designed by adaptive method

Web technologies provide resources for the intensive use of colors in web pages. They are a core element in the design of interactive interfaces and are essential in the perception and understanding of information. However, color intensive design on the web affects the accessibility for users with color vision deficiency (CVD), who face difficulties in recognizing or distinguishing colors. CVD users may experience limitations and barriers in exploring web pages, even for simple tasks. Interface adaptation techniques may deal with several CVD visualization issues. Nevertheless, different situations and individual preferences turn choosing the most suitable recoloring technique into a complex task. Existing proposals in the literature fail in not considering various pathology types and individual preferences. This article defines a framework and techniques for the development of adaptive interfaces that facilitate the interaction of CVD people with web systems. The proposed research develops the FAIBOUD framework, which uses ontologies as artifacts for representing knowledge about CVD types, recoloring algorithms, and users’ access contexts and preferences. The FAIBOUD includes algorithms to support an adaptation decision process, which selects the most suited adaptation technique according to CVD type and access context. Our solution allows for the determination and automatic application of the best recoloring techniques to adapt interfaces for CVD users. Our experimental evaluation was conducted with fifteen CVD users. The results obtained from several illustrative scenarios demonstrate the benefits and enhancement of web interface accessibility based on our adaptive approach.

Dear Sir, As members of the state's medical board, the authors wish to share some of the difficulties encountered while testing candidates for color vision deficiency (CVD). Though many methods for color vision testing are available, there is no consensus on the ideal method, with different countries using different tests. In India, the Ishihara charts are the most widely used, with additional use of Edridge-Green lantern in civil services and Martin lantern in armed forces.[1,2] The Ishihara test is quick and easy and is an excellent screening tool to detect those with red-green CVD. However, it has a limited ability to classify CVD and determine its severity. Organizations that require the correct recognition of colored signals (principally transport groups such as the Civil Aviation Authority, Railways, Maritime, and Naval and Air force) depend on a standard lantern test which imitates actual signal systems simulating the workplace. Lanterns do not specifically screen for color defects. It is surprising that even now, the general design of lanterns has not changed very much since their creation in 1891. With the exception of the Farnsworth lantern used in the USA, there are scarce studies on the validation and reliability of lanterns. The panel tests, including the Farnsworth Panel D-15 and Farnsworth–Munsell 100-hue tests, are much more accurate in classifying color deficiency. Farnsworth Panel D-15 Test is considerably quicker and more convenient test for routine clinical use. Though not very sensitive, its speed and accuracy make it useful. The relative insensitivity can also be an asset in judging the practical significance of mild degrees of color deficiency. For example, individuals who fail the Ishihara plates but pass the D-15 panel will probably not have color discrimination problems under most circumstances and in most jobs.[3] Nagels anomaloscopes is considered the gold standard for color vision testing in clinical research, however, it is an expensive instrument requiring an experienced examiner's skills. Color vision is graded into higher and lower grade depending on the size of the aperture in the Edridge-Green lantern (1.3 mm vs. 13 mm),[1] with the technical services category of Indian civil services, which includes police services requiring higher grade of color vision. The United States police service no longer implements a color vision standard though monochromats are barred.[4] Those who fail initial color vision screening by pseudoisochromatic plates should be further evaluated by anamaloscope or D-15 test to include anomalous trichromats who are the most numerous among the CVD persons. In an ongoing study, 500 candidates who appeared in the divisional medical board were studied. Ishihara chart was used for initial screening of all candidates with further use of Edridge-Green lantern for candidates found to have CVD and selected for jobs requiring high grade of color vision. Sixty candidates (13%) were found to have CVD; 39 of those were selected for jobs requiring accurate color perception. None of the candidates found to have CVD on testing by Ishihara chart could pass the lantern test. Only 21 candidates found to have CVD were previously aware of their deficiency. Since color judgment is an integral part of work in various occupations, a screening test to establish color vision should be undertaken while giving career's advice. An early diagnosis of CVD might allow for early modifications in educational and other activities. Furthermore, there is a need to supplement the existing color vision tests for various services in India, with more objective, diagnostic tests such as the D-15, maintaining standard illumination. Use of color enhancing appliances (X-chrome and chromagen contact lenses) should be ruled out. Computer-based programs are needed so that easily reproducible and acceptable methods of testing are developed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

PurposeTo investigate the influence of color vision deficiency (CVD) on the ability of practicing optometrists to correctly identify lesions in digital color fundus photographs with and without the aid of a commercially available color vision remediation device.MethodsThis study was conducted at the 2024 annual meeting of the American Academy of Optometry in Indianapolis, IN, USA. The color vision of each subject was assessed using the Konan ColorDx CCT-HD®. Individuals with a score <90 for any cone type were classified as having CVD. Each subject then attempted to correctly identify lesions in a series of 12 digital color fundus photographs. Subjects identified as having CVD repeated the photograph task while wearing EnChroma® indoor lenses. The quality of life (QoL) of each subject was evaluated using a modified version of the Color Blindness QoL survey.ResultsFifty-five optometrists completed the study. Forty had normal color vision (CVN) and 15 had CVD. Four of 15 (27%) CVD optometrists were previously unaware of their CVD. Both age and CVD influenced the ability of optometrists to correctly identify lesions. Among CVN subjects, younger clinicians (<39 years) outperformed older ones (p = 0.001). However, among subjects with CVD, age did not significantly affect performance (p = 0.84). Compared across CVD status, younger clinicians with CVD performed worse than their normally sighted peers (p = 0.002) while CVD had little effect among older clinicians (p = 0.23). Performance did not improve with use of the EnChroma lenses. Approximately half (47%) of optometrists with CVD reported difficulties in their daily activities attributed to poor color perception.ConclusionsCVD and older age decreased the ability of optometrists to correctly identify lesions in fundus photographs. Performance did not improve with use of the EnChroma lenses. Our findings suggest that CVD may pose a disability to eye care providers. We endorse the recommendation that individuals entering medical practice undergo color vision testing and counseling if a deficiency is found.

This paper presents a model reference adaptive control design approach for a class of nonlinear systems. A nonlinear reference model is considered in the design of adaptive control for the nonlinear system. The design approach is based on successive linear time varying (LTV) approximations of the nonlinear reference model and the system. The convergence proof of the responses of successive approximations to the response of nonlinear system is given. Provided that there exists an adaptive control for the approximated system, the model reference adaptive control is then designed for LTV systems whose responses converge to the response of the nonlinear system. The proposed model reference adaptive control approach is illustrated with an example which shows the effectiveness of the method.

Decimations of intrinsic mode functions via semi-infinite programming based optimal adaptive nonuniform filter bank design approach