Adaptive State Research Articles

Social Adaptation of the Elderly to Digital Transformation of Society: The Sociological Research in Hanoi Capital and Ho Chi Minh City (Vietnam)

Introduction. The population aging in Hanoi Capital and Ho Chi Minh City (Vietnam) coincides with the development of the 4th Industrial Revolution and digital transformation. The article aims to analyze the current state of social adaptation of elderly people in Vietnam to the digital transformation of society through their attitudes and levels of accessing and using to certain types of digital technologies in the economic, political, social and cultural field. Materials and Methods. The sociological survey of 984 elderly people in Hanoi and Ho Chi Minh City was conducted from May to September 2022. SPSS version 25.0 was used for statistical analysis and quantitative testing. The national census reports and population aging data were also analyzed. Results. Elderly people are poorly aware of the function and usefulness of some digital technologies, although this technologies are quite popular, necessary, and even created only for them. Therefore, they do not have good access to them. The main reasons are ignorance, the absence of help and guidance. However, elderly people believe that digital technologies will help them live happier and more convenient. Discussion and Conclusion. Equipping the younger generation with digital knowledge and skills is a necessary preparation for the goal of “active aging” in digital era. The government needs more relevant projects to improve the social adaptation of elderly people; pay attention to the best solution to the digital divide for elderly people being in rural area, poor group, low education and living alone. The results of this article provide some important implications for state agencies, elderly associations, family institutions and the elderly. This results will supply ideas to build necessary solutions and policies for the elderly in the digital era.

Design of an Adaptive State Anesthesia Feedback Controller

Anesthesia is critical in medical procedures to ensure the patient's body remains stable and unresponsive during surgery. However, administering the correct dose can be challenging, particularly in prolonged surgeries. An auto-controlled system that incorporates vital sensors and a microprocessor controller has been proposed to address this issue. This system uses an infusion pump to provide the correct amount of anesthetic based on the patient's vital signs. The microprocessor takes control of the system once initiated and signals the motor driver to start injecting the required amount of anesthesia while monitoring vital signs such as temperature, heartbeat, and Spo2. The system alerts the doctor if any abnormality is detected, and the supply of anesthetic is stopped until everything returns to normal. This system ensures accurate anesthetic dosage, minimizing the risk of complications and ensuring a safe surgical procedure.

Fault tolerant control for a class of nonlinear systems with multiple faults using neuro-dynamic programming

Considering the multiple fault scenario, i.e., both actuator and sensor faults occur simultaneously, this paper develops a neuro-dynamic programming (NDP)-based fault tolerant control (FTC) scheme for a class of nonlinear systems. By combining a descriptor observer with an adaptive observer, system states and multiple faults are estimated simultaneously. For the nominal system, i.e., the fault-free system, a critic neural network (NN) is employed to solve the Hamilton–Jacobi-Bellman (HJB) equation, and the approximate optimal control policy is obtained. To eliminate the influence of sensor faults, the accurate estimations of system states are used instead of system states from faulty sensors to construct the approximate optimal control policy. Then, by combining the estimations of actuator faults with the approximate optimal control policy, an FTC law is developed to suppress the influence of actuator faults. The stability of the closed-loop nonlinear system is analyzed to be uniformly ultimately bounded via the Lyapunov stability theorem. The effectiveness of the present FTC scheme is demonstrated by two simulation examples.

Гипотеза о возможных механизмах терапевтического действия гексанового экстракта Serenoa repens на состояние гипертрофированного мочевого пузыря в соответствии с патогенезом его дисфункции при инфравезикальной обструкции.

Introduction. Traditionally it is believed that the therapeutic effect of the hexane extract of Serenoa repens (HSRE) in patients with benign prostatic hyperplasia is realized due to its effect on prostate cells. However, in the literature there is data about the possible HSRE effect not only on the prostate, but also directly on the bladder. This paper summarizes data and analyzes the possible cellular mechanisms of HSRE action on the bladder under the development of infravesical obstruction (bladder outlet obstruction – BOO). Materials and methods. Literature data from the PubMed and eLibrary.ru databases for a 25-years period related to the study of the pathogenesis of bladder dysfunction in the development of BOO, cellular and molecular mechanisms by which pathological and adaptive processes in bladder cells are realized, as well as the influence of HSRE on these processes are analyzed. Results. The concept of the pleiotropic effect of HSRE on various links in the pathogenesis of bladder dysfunction caused by BOO has been formed. The main of which are: the antioxidant and anti-inflammatory effects of HSRE components, as well as the regulatory effect on cell growth and proliferation factors and transcription factors. All this reduces the cytotoxic effect of oxidative stress on the cells of the bladder developing in IVO, contributing to a more active proliferation of detrusor smooth muscle cells. The consequence of the complex action is to maintain the contractile function of the bladder in a state of adaptation to increased stress, due to BOO. Conclusions. The present hypothesis about the direct effect of HSRE on the hypertrophied bladder and possible mechanisms of its therapeutic action is based on an understanding of the general biological mechanisms and allows us to explain better the results of previous clinical studies and to assess the prospects for expanding the scope of further drug application.

Effect of monochromatic light on light adaptation and opsin expression in Ectropis grisescens.

Light has a substantial effect on the behaviour and physiology of nocturnal moths. Ectropis grisescens is a major nocturnal tea pest in China, and light traps are commonly used to control geometrid moths because of their positive phototaxis. However, some moths gather around light traps and enter the light adaptation state, which decreases the efficacy of light traps in controlling this pest. We identified opsin genes and the spectral sensitivities of the photoreceptors of E. grisescens moths. We also determined the effects of several monochromatic lights on opsin gene expression and light adaptation. We detected three types of opsin genes and six spectral sensitive peaks (at 370, 390, 480, 530, 550, and 580 nm). We also observed significant changes in the diurnal rhythm of opsin gene expression under different light conditions. When active males were suddenly exposed to different monochromatic lights, they quickly entered the light adaptation state, and the adaptation time was negatively correlated with the light intensity. Males were most sensitive to 390 nm wavelengths, followed by 544 nm, 457 nm, and 593 nm. Red light (627 nm) did not affect the activity of E. grisescens males but had detectable physiological effects.

Finite-time adaptive practical tracking control for high-order nonlinear systems with full-state constraints and input saturation

This paper focuses on finite-time adaptive practical tracking control for a class of high-order nonlinear systems with full-state constraints and input saturation. The state constraints are handled by applying nonlinear transformed functions (NTFs) and the input saturation is estimated by an auxiliary hyperbolic tangent function. On the basis of adding a power integrator technique and adaptive control method, an adaptive state feedback controller is designed for the closed-loop system. With the aid of finite-time stability theory, the tracking error converges to a bounded neighbourhood of the origin in a finite time, and all the signals in the closed-loop system are bounded. At last, a simulation example and a practical example are presented to show the effectiveness of the proposed control procedure.

The influence of physical training on indicators of the functional state of the cardiovascular system of young boxers during the stage of initial training

The article is devoted to the problem of assessing indicators of the functional state of young martial artists (on the example of boxing). The goal is to investigate the dynamics of changes in the functional state of the cardiovascular system of young boxers during the stage of initial training. The research was conducted on the basis of "Complex Children's and Youth Sports School for Boxing and Martial Arts" of the DMR during 2021-2022. 35 young athletes participated in the research. It was established that in September 2021, the average group indicators of heart rate and average blood pressure corresponded to age norms; systolic and diastolic blood pressure indicators were higher than the age norm, pulse pressure indicators were lower. The assessment of the Robinson index indicated the predominance of a low level, which indicated the presence of signs of dysregulation in the activity of the CVS; in 80.0% of athletes, the state of adaptation was defined as "satisfactory adaptation". During almost a year of boxing classes (in December 2022), a repeated study confirmed the positive dynamics of the functional state of the CVS: the percentage of athletes who had an average level of the CVS condition increased statistically significantly to 83%, in 97.14% the state of adaptation was defined as "satisfactory adaptation".

Adaptive neural dissipative control for markovian jump cyber-Physical systems against sensor and actuator attacks

This work addresses the issue of adaptive neural dissipative control for Markovian Jump Cyber-Physical Systems subject to output-dependent sensor and state-dependent actuator attacks. Attackers can inject false information into feedforward and feedback signals to degrade system performance or even destabilize the system. To identify and approximate attack signals, neural network technique is employed. Attacks are successfully withstood by constructing the estimated signals of these approximate functions. New adaptive state and output feedback controllers are being developed in the meantime. Then, by adapting Lyapunov function technique, sufficient conditions are provided to achieve the stochastic stability of the considered system with extended dissipation. Last, two practical examples are applied to elucidate the effectiveness of the devised adaptive neural control approaches.

Adaptive quantized control for a class of high‐order nonlinear systems

AbstractIn this article, the adaptive stabilization problem is addressed for a class of nonlinearly parameterized systems with quantized input. The quantizer parameters and virtual control coefficients are unknown, and the linearization of the nonlinear systems is uncontrollable. A novel nonlinear time‐varying model is proposed to deal with the quantized input. Through the proposed nonlinear model, the quantized adaptive control problem is converted into the adaptive stabilization problem for nonlinear high‐order system with unknown virtual control coefficients. Then, based on the tuning function approach and adding power integrator technique, adaptive laws and an adaptive state feedback controller are designed. Further, it is shown that by adjusting some design parameters, the proposed scheme enables the stabilization error converges to an arbitrarily small neighborhood of the origin. Simulation is also provided to verify the validity of proposed scheme.

Multi-objective real-time energy management for series–parallel hybrid electric vehicles considering battery life

The real-time control of energy management strategy (EMS) is becoming increasingly challenging as the complexity of the model and control strategy increases. To address this issue while ensuring the accuracy of the EMS, a multi-objective real-time EMS based on model predictive control (MPC) that considers battery life is proposed in this paper. Firstly, to balance the accuracy and efficiency of the prediction module, a kernel extreme learning machine based on the whale optimization algorithm is proposed as a short-term speed prediction model. Secondly, an adaptive state of charge (SOC) trajectory planning method is established to plan MPC reference trajectory. Next, to optimize fuel efficiency, electrical energy consumption, and battery aging in real-time, a multi-objective real-time MPC (MOR-MPC) algorithm is proposed. Finally, the effectiveness, real-time performance, and robustness of the proposed strategy are verified. Simulation results demonstrate that the total cost of the strategy is reduced by 6.15% compared to the equivalent consumption minimization strategy (ECMS), with 98.17% of dynamic programming (DP) performance achieved. Real-time performance is improved by 97.89% compared to DP-MPC. Hardware-in-the-loop (HIL) testing is also carried out to evaluate the proposed strategy.

New Role of D-Cycloserine: Shorten Adaptation Process and Extend Maintenance Time of Motion Sickness

Introduction: The aim of the study was to investigate the role of D-cycloserine (DCS) in the adaptation process and maintenance of motion sickness (MS). Methods: In experiment 1, 120 SD rats were used to study the promoting effect of DCS on the adaptation process of MS in rats. They were randomly divided into four groups, DCS-rotation (DCS-Rot), DCS-static, saline-rotation (Sal-Rot), and saline-static, and further divided into three subgroups according to the adaptation time (4 days, 7 days, and 10 days) in each group. After being given DCS (0.5 mg/kg) or 0.9% saline, they were rotated or kept static according to the group. Their fecal granules, total distance, and total activity of spontaneous activity were recorded and analyzed. In experiment 2, other 120 rats were used. The experimental grouping and specific experimental method were the same as experiment 1. According to the grouping of the adaptive maintenance duration, the animals of 14 days, 17 days, and 21 days groups were measured on the corresponding date of the changes in the animals’ exploratory behavior. Results: In experiment 1, the fecal granules, total distance, and total activity of spontaneous activity of Sal-Rot returned to the control level on 9 days, and the DCS-Rot group returned to the control level on 6 days, indicating that DCS could shorten the adaptation time of MS rats from 9 days to 6 days. In experiment 2, the Sal-Rot could not maintain the adaptive state after 14 days’ absence from the seasickness environment. The fecal granules of DCS-Rot increased significantly, and total distance and total activity of spontaneous activity of DCS-Rot decreased significantly from 17 days. These illustrate that DCS can prolong the adaptive maintenance time from within 14 days to 17 days in MS rats. Conclusion: 0.5 mg/kg DCS injected intraperitoneally can shorten the MS adaptation process and extend the maintenance time of adaptation of SD rats.

18‐3: Computing Display Color Gamut Volume using Tetrahedra

We describes an approach to computation of display color gamut volume (sometimes called color volume). We describe two methods of partitioning color space into tetrahedra, and methods of aggregating the volume of tetrahedra. There some mathematical subtleties that need to be addressed to efficiently obtain the correct result. We discuss the constraints that guide a suitable choice of color space in which to perform the calculation. Our goal is to characterize the range of physical stimuli produced by a display. We want a perceptual measure of this volume, but we want the metric to cover the entire range of physical display stimuli, not just the range attained at a particular state of the viewer's adaptation. We comment on using CIE LAB or BT.2124 ITP5 as the underlying colorspace, and suggest that ITP is most useful.

Finite-Time Refined Antidisturbance Velocity Tracking Control for Gimbal System of Control Moment Gyros With Harmonic Drive

This paper is concerned with high-precision and fast velocity-tracking control for the harmonic drive-based gimbal system of control moment gyro (CMG). As a major challenge in the controller design, the simultaneous presence of multiple matched and mismatched disturbances should be carefully addressed. Specifically, the rotor imbalance inherent in the CMG will cause vibration of the output torque that significantly degrades the tracking performance. On the other hand, the integration of harmonic drives will lead to nonlinear torsional stiffness and introduce additional frictions into the control system. Furthermore, practical tasks such as fast attitude maneuver have posed higher requirement on the rapidity of the anti-disturbance control schemes. To overcome the aforementioned difficulties, we propose a finite-time refined anti-disturbance velocity tracking controller, which consists of a finite-time harmonic disturbance observer (FTHDO) to compensate for the imbalance vibration, an adaptive finite-time extended state observer (AFTESO) to handle the remaining disturbances with unknown rate of change, and a finite-time controller to ensure fast convergence of the tracking error. Both numerical simulation and hardware-in-the-loop (HIL) experimental results show that the proposed scheme outperforms the existing methods in terms of accuracy and rapidity.

Peculiarities of relationships between the characteristics of psychophysiological adaptation of organism and criterion indicators of motor activity of modern students


 
 
 one of the priority components of the implementation of modern physiological and hygienic research is a prognostic assessment of the features of the leading characteristics formation of the adaptive resources state of the student’ organism based on the use of modern methods of statistical analysis in accordance with the conditions of stay, which differ in the features of the influence of health- creating factors, among which it is necessary to include level of motor activity. The purpose of the study was to determine the peculiarities of the relationships between the characteristics of psychophysiologi- cal adaptation and criterion indicators of motor activity of modern students based on the application ofcluster and factor analysis procedures. In the course of the scientific work 285 students (150 young wom- en and 135 young men) were supervised, who were divided into 3 comparison groups according to the level of motor activity. Individuals with high motor activity (group 1 of motor activity: 50 young women and 45 young men), medium motor activity (group 2 of motor activity: 50 young women and 45 young men) and low motor activity (group 3 of motor activity: 50 young women and 45 young men) levels were involved in their composition. As criterion indicators of motor activity, it was necessary to note the indicators of daily energy expenditure, which were estimated according to the timing-table method - up to 9000 kJ (low level of motor activity), 9000-11000 kJ (medium level of motor activity), more than 11000 kJ (high level of motor activity) among girls , and indicators of motor activity – up to 11,000 kJ (low motor activity level), 11,000-13,500 kJ (medium motor activity level), over 13,500 kJ (high motor activity level) among young men. Medical-sociological, epidemiological, psychophysiological, psycho- logical-pedagogical and statistical methods were used in the scientific work. In the course of the con- ducted research, based on the application of cluster and factor analysis procedures, the features of the relationships between the characteristics of the functional state and the level of development of psycho- physiological functions and, therefore, the leading characteristics of psychophysiological adaptation and criterion indicators of motor activity of modern students were determined. Data of cluster analysis procedures usage determined that the leading characteristics of the state of health and academic success were most significantly influenced by 3 leading clusters of characteristics of the psychophysiological adaptation of the students’ organism, namely: visual-motor speed, visual-sensory and integrative-coor- dination clusters. At the same time, based on the results of the application of factor analysis procedures, it was established that the most positive effect on the functional state of the organism of young women and young men was exerted by the movement regime characteristic of students, the values of daily energy expenditure of which vary between 9000-11000 kJ and between 11000-13500 kJ.
 
 

Adaptive control for heterodirectional 2 × 2 hyperbolic PDEs with spatially varying coefficients and uncertain nonlinear actuator dynamics

In this paper, we aim to develop adaptive asymptotic stability for heterodirectional 2 × 2 hyperbolic PDEs with parametric-strict-feedback nonlinear actuator dynamics. First, we transform the heterodirectional 2 × 2 hyperbolic PDEs with spatially varying coefficients into a stable target subsystem by utilizing the infinite-dimensional backstepping transformation. Second, an adaptive state feedback controller is constructed by combining finite-dimensional state transformation and adaptive compensation technology to assure the boundedness of all the signals in the closed-loop system. Meanwhile, we show that the PDE states converge to zero pointwise in space, the nonlinear ODE states and the control input also converge to zero. Finally, a simulation example is provided to illustrate the effectiveness of the proposed method.

Оцінка адаптаційно-компенсаторних можливостей дівчат із розладами менструальної функції

The duration and regularity of the menstrual cycle are influenced by many factors, including psychosocial stress, which can lead to activation of the hypothalamic-pituitary-adrenal system. Purpose - to assess the levels of stress hormones cortisol, insulin (IRI), prolactin, and the cortisol/insulin (K/In) index in adolescent girls with menstrual disorders. Materials and methods. 177 adolescent girls aged 12–17 years with menstrual disorders were examined (87 with abnormal uterine bleeding (АUB), 90 - with oligomenorrhea (OM)). The comparison group consisted of 57 girls of the same age with normal menstrual cycles examined in the early follicular phase. The level of cortisol, insulin, prolactin (PRL) was measured in blood serum on an empty stomach using the immunoenzyme method to determine the level of organism’s adaptive capabilities. All hormones were defined according to the instructions for the kits. The ratio of K/In was calculated. Results. In girls with menstrual disorders, three types of reaction from the adrenal glands were found, which were expressed in increased levels of cortisol above 75 and 90 percentile, a decrease (below 10 percentile) and its fluctuations within physiological values. At cortisol values above the 90 percentile, the average level of glucose, IRI, and HOMA in teenage girls with OM did not differ from the normative values, and in patients with AUB these indicators were significantly higher than in adolescents with OM. The K/In ratio in girls with OM by 1.8 times exceeded the similar indicator of adolescents with AUB (p<0.04) and was slightly higher than in the comparison group, which indicates a satisfactory reaction of stress tolerance. With AUB, this coefficient decreased, which may indicate exhaustion of the body’s adaptive capabilities. The same situation was observed when cortisol increased above the 75 percentile. When the cortisol level was within physiological values, the content of glucose and IRI also did not go beyond the limits of normative fluctuations. The stress ratio (K/In) had no significant difference depending on the type of violations and was significantly reduced. The absence of changes in the content of cortisol and IRI in the blood serum in response to the onset of menstrual disorders may indicate a certain instability in the development of the body's protective reactions in teenage girls with menstrual disorders. Conclusions. The revealed changes in the content of cortisol, insulin, K/In and PRL as markers of a non-specific stress reaction in the structure of the adaptive response in disorders of menstrual function carry additional information about impaired adaptation to stress and the state of compensatory capabilities of the girl's body, expand the understanding of pathogenetic mechanisms these disorders and can be used both in the assessment of the state of adaptation and in the development of appropriate preventive strategies. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of all participating institutions. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Individual-psychological characteristics and the state of psychosocial adaptation of combatants with non-psychotic mental disorders who have experienced COVID-19

The relevance of the studied subject lies in the importance of investigating the individual-psychological characteristics, coping behaviour, and the state of psychosocial adaptation of combatants who have recovered from COVID-19, to develop personalised therapeutic and rehabilitation measures The purpose of the study was to determine the pathocharacterological characteristics, coping repertoire features, and psychosocial maladaptation in individuals who participated in combat operations, have non-psychotic mental disorders, and have experienced the coronavirus infection, in a comparative aspect. A total of 132 male combatants with non-psychotic mental disorders who did not have COVID-19 and 120 military personnel with the same mental disorders who had experienced the coronavirus infection were examined using Standardised Multifactor Personality Inventory, questionnaire “Methods of coping behavior”, and the Social-Psychological Adaptation Diagnostic Method. It was found that combatants who had experienced COVID-19 exhibited specific personality characteristics that can be considered pathocharacterological transformations and signs of neuroticism. The core pathocharacterological changes included stable anxious-depressive and hyposthenic traits, while the auxiliary psychopathological constructs included stable emotionally labile, asthenic, hypochondriacal, and dysphoric manifestations. They also exhibited changes in coping repertoire with a predominance of non-constructive strategies of escape-avoidance and confrontation, along with a deactualisation of constructive coping strategies such as problem-solving planning, seeking social support, self-control, and positive reappraisal. Furthermore, pronounced manifestations of psychosocial maladaptation were observed in all key domains. COVID-19 acts as a complicating factor, exacerbating psychopathological symptoms, contributing to the formation of pathocharacterological traits, and deepening the psychosocial maladaptation of combatants with non-psychotic mental disorders. The obtained data provide an opportunity to personalise therapeutic, rehabilitation, and preventive measures, considering the pathocharacterological individual-psychological characteristics and coping behaviour, and to improve existing programmes of social-psychological adaptation for combatants

REAC Neurobiological Modulation as a Precision Medicine Treatment for Fibromyalgia.

Fibromyalgia syndrome (FS) is a disorder characterized by widespread musculoskeletal pain and psychopathological symptoms, often associated with central pain modulation failure and dysfunctional adaptive responses to environmental stress. The Radio Electric Asymmetric Conveyer (REAC) technology is a neuromodulation technology. The aim of this study was to evaluate the effects of some REAC treatments on psychomotor responses and quality of life in 37 patients with FS. Tests were conducted before and after a single session of Neuro Postural Optimization and after a cycle of 18 sessions of Neuro Psycho Physical Optimization (NPPO), using evaluation of the functional dysmetria (FD) phenomenon, Sitting and Standing (SS), Time Up and Go (TUG) tests for motor evaluation, Fibromyalgia Impact Questionnaire (FIQ) for quality of life. The data were statistically analyzed, and the results showed a statistically significant improvement in motor response and quality of life parameters, including pain, as well as reduced FD measures in all participants. The study concludes that the neurobiological balance established by the REAC therapeutic protocols NPO and NPPO improved the dysfunctional adaptive state caused by environmental and exposomal stress in FS patients, leading to an improvement in psychomotor responses and quality of life. The findings suggest that REAC treatments could be an effective approach for FS patients, reducing the excessive use of analgesic drugs and improving daily activities.

Construction and Optimization Strategy of County Ecological Infrastructure Network Based on MCR and Gravity Model—A Case Study of Langzhong County in Sichuan Province

Against the backdrop of rapid urbanization, there is a passive adaptation state shown in urban and rural ecological spaces. Due to the shrinking of ecological patches and the fracture of corridors, problems such as the obstruction of ecological processes, the decline of ecosystem services, and the loss of biodiversity occur. Considering that county ecological space is the key level to undertake provincial ecological security patterns and implement ecological demonstration projects, the construction of a county ecological infrastructure (EI) network is beneficial to the protection of regional ecological security, the improvement of the structures and functions of farmland ecosystems, and the enhancement of the quality of human settlements. In this study, taking Langzhong County in Sichuan Province as an example, a method path for an EI network construction was explored, and an optimization strategy for ecological patterns was proposed. Firstly, morphological spatial pattern analysis (MSPA) and a patch importance index were employed to identify ecological sources. Secondly, by constructing a landscape resistance surface and adopting a minimum cumulative resistance (MCR) model, potential EI corridor paths were extracted. Thirdly, the interaction force values between ecological sources were calculated with a gravity model and important ecological corridors were identified for priority protection and restoration. Finally, an EI corridor network was optimized by combining network structure indexes (α, β, and γ) with the field situation, and stepping stone patches and ecological breakpoints were identified. Based on the analysis results, an ecological protection pattern, which involved three vertical and two horizontal ecological belts, four ecological control zones, and six clusters of EI networks in Langzhong County, was put forward, aiming at protecting 50 ecological sources, repairing 105 ecological corridors of different grades, adding 9 stepping stone patches near long-distance corridors and 15 at the intersection of ecological corridors, and repairing 18 ecological breakpoints. This study has guiding significance for the optimization of county ecological patterns, the construction of farmland forest belts, and site selection of ecological restoration projects.

Effect of surrounding objects in the adapting scene on chromatic adaptation.

Most of the existing chromatic adaptation transforms (CATs) were developed for flat uniform stimuli presented in a uniform background, which substantially simplifies the complexity of the real scene by excluding surrounding objects from the viewing field. The impact of the background complexity, in terms of the spatial properties of the objects surrounding the stimulus, on chromatic adaptation is ignored in most CATs. This study systematically investigated how the background complexity and color distribution affect the adaptation state. Achromatic matching experiments were conducted in an immersive lighting booth, with the illumination varying in chromaticity and the adapting scene varying in surrounding objects. Results show that compared to the uniform adapting field, increasing the scene complexity can significantly improve the degree of adaptation for the Planckian illuminations with low CCT levels. In addition, the achromatic matching points are substantially biased by the color of the surrounding object, implying the interactive effect of the illumination color and the dominant scene color on the adapting white point.