Concept Of Uncertainty Research Articles

A study of the influence of heterogeneous friction coefficient and heterogeneous contact stiffness on the generation of squeal

Friction and contact characteristics play important roles in brake squeal generation, while their heterogeneous characteristics are often neglected. In this paper, a flexible pin-on-disc system model is established. Squeal bench test is carried out to verify the correctness of the model. Random heterogeneous friction coefficients and contact stiffnesses are built and assigned to the model. Evaluation indexes of friction and contact heterogeneities are established. The unstable region and the squeal uncertainty are analyzed. Then, the influence of the heterogeneous friction and contact characteristics on generation of brake squeal is explored based on statistical method and uncertainty concept in the unstable region and the mix region respectively. The results show that when only friction coefficient is heterogeneous, the radius of the center position of friction coefficient is the key influencing factor of brake squeal; when only contact stiffness is heterogeneous, the radius of the center position of contact stiffness is the key influencing factor of brake squeal; when friction coefficient and contact stiffness are both heterogeneous, the mean value of the product of friction coefficient and contact stiffness and the radius of the center position of friction coefficient play critical roles on friction squeal. Besides, squeal tends to occur when the mean value of the product of heterogeneous friction coefficient and contact stiffness and the radius of the center position of friction coefficient are large.

Digitalization and Uncertainty in the University: Coherence and Collegiality Through a Metacurriculum

Recent initiatives to promote ‘digitalization’ in education exhorting increased digital literacy and ‘computational thinking’ have invited implementation research methods to transform curricula, teaching, and learning. While conceived as a movement from the present of education to an imagined future where envisaged curricula embrace data-oriented and computational practices across subjects, we ask: whose present? Whose future? We revisit the concept of a metacurriculum (first conceived in the 1990s) as a way of addressing this question, while not avoiding the challenges inherent in the adaptation of education to an increasingly complex postdigital environment. We argue that the principal challenge facing institutional and individual adaptation is increasing environmental uncertainty produced by technology, not deficiency in individual skills. Using the uncertainty concept, we present a practical co-designed and dialogical approach supporting the student and teacher journeys towards the transdisciplinary opportunities opened out by technology, based on a cybernetic model of intersubjectivity. We discuss the explanatory power of uncertainty in this context, focusing on the ways it can encourage dialogue, collegiality, and experimentation. Evidence for this is presented in a case study from a Russian University Business School where a large group of teachers co-designed and delivered a dialogical module on digitalization and interdisciplinarity over a period of 4 years—a collaboration ended by recent geopolitical events. In analyzing data from one of the central activities of this course, we focus on the teacher collegiality and the students’ mechanisms of selection in navigating the transdisciplinary space, and how these mechanisms may provide deeper insight into the dialogical underpinnings of education.

Time-varying characteristics of friction squeal and the influence of heterogeneous friction and contact characteristics based on transient simulation

Friction squeal is a major issue for car manufacturers as it is the reason for the return of many vehicles to customer services, representing high costs for the companies. One of the reasons for the difficulty in prediction and suppression of squeal is its time-varying characteristics. Heterogeneous characteristics of friction and contact characteristics have a great effect on occurrence and evolution of friction squeal. However, the heterogeneous characteristics are always ignored. In this paper, friction squeal test is carried out, and time-varying characteristics of friction squeal are analyzed. A flexible pin-on-disc system model is established. The time-varying characteristics of friction squeal are analyzed by transient simulation, and the effectiveness of the model is verified by the bench test. Then, heterogeneous friction and contact parameters are generated and assigned to the contact surface of the model. Evaluation indexes of time domain characteristics are established to reflect the intensity of squeal. The product of friction coefficient and contact stiffness are introduced to reflect their combination effect on squeal, and the evaluation indexes of heterogeneous friction and contact characteristics are built. Furthermore, uncertainty of friction squeal time domain characteristics is analyzed, when heterogeneous friction and contact parameters are treated as random parameters. The influence of heterogeneous friction and contact parameters on friction squeal is studied by the combination of uncertainty concept and statistical analysis. The research shows that when evaluation indexes of heterogeneous friction coefficient and contact stiffness obey normal distribution, the root mean square (RMS) acceleration of the free end of the pin (RMSAFP) and squeal time (ST) obey skewed distribution. Besides, the mean value of the product of heterogeneous friction coefficient and contact stiffness is the most critical influencing factor on squeal. Squeal intensity increases with the increasing mean value of the product of heterogeneous friction coefficient and contact stiffness. Moreover, the radius of the center position of heterogeneous friction coefficient has some effect on friction squeal. The method and conclusion proposed in this article can be contributed to improving accuracy of the prediction model and providing reference for squeal suppression from the aspect of surface treatment.

COVID and the Risky Immigrant Workplace: How Declining Employment Standards Socialized Risk and Made the COVID-19 Pandemic Worse.

This article investigates the impacts of the COVID-19 pandemic in NYC as they were concentrated on immigrant workers and their communities, studying one group of immigrant workers, namely taxi drivers. Based on two years of ethnographic research with the New York Taxi Workers Alliance, a union of 24,000 taxi and app-based drivers in NYC, conducted before and during the pandemic, as well as formal interviews and an original survey of 1,002 union members, my research shows how drivers’ precarious existence in the work–citizenship nexus informed their experiences of sustaining their families during the pandemic. COVID highlighted how the welfare state’s increasing privatization of risk, the fissuring of the workplace, and the rise in employment precarity have generated an immigrant underclass. This manifested in immigrant drivers experiencing the pandemic through the lens of specific uncertainties—health, economic, bureaucratic, and immigration—that shaped their unequal access to pandemic support. This process in turn produced a boomerang effect, as immigrant drivers’ weaker connection to state and social institutions made it harder to contain the virus in their communities, a development which ultimately puts society writ large at greater risk. This article advances our knowledge of precious employment by introducing the concept of uncertainties to explain the socio-cultural aspects of how crises of social reproduction are generated. It also extends our understanding of the decline of the welfare and regulatory state by showing how this process interacts with immigrant status.

Bridging the Gap Between Competencies and Uncertainties in Postgraduate Training in Family Medicine: Results and Psychometric Properties of a Self-Assessment Questionnaire.

PurposeOne of the reasons for postgraduate trainees not to choose working in a rural area is uncertainty related to the lack of competencies. The aim of this study was to investigate the concept of uncertainty by measuring competencies and to examine the psychometric properties of an instrument that measures competencies related to uncertainty in the self-assessment of postgraduate trainees in family medicine.Patients and MethodsA questionnaire was created based on pre-existing instruments. It was distributed to participants of postgraduate training seminars in the federal states of Baden-Württemberg and Schleswig-Holstein, Germany in 2016. Descriptive statistics and a partial correlation analysis were calculated for measuring the degree of association between year of postgraduate training and items’ responses. Psychometric properties were assessed by calculating descriptive item analysis, factor analysis and internal consistency.ResultsThe response rate was 85% (105/124). More than one-fifth of the participants stated to show only seldom or sometimes the following skills: ability to balance work and life (N=25, 24%), letting a mild disorder run its own way (N=24, 23%) and ability to conduct interventions that decreased aggression from the patient (N=22, 21%). More than half of the participants felt (very) insecure in performing routine child check-ups, the application of a below elbow backslab and the partial removal of a toenail. Nine out of 21 items showed positive statistically significant correlation between level of competence and progress in training. Factor analysis led to a final instrument with 12 items (Cronbach’s α=0.736) and a three-factor-structure: “doctor well-being and resilience”, “communication” and “skills”.ConclusionIn order to reduce uncertainty with all its consequences, a focus on teaching of competencies regarding the physicians’ well-being and resilience, communication and skills has to be continued in postgraduate training.

AHMED NADEEM QASMI'S MENTAL TENDENCIES

Ahmed Nadeem was acclaimed high pedestal of fame in modern Urdu poetry especially, his ghazal attracted numerous readers and critics. In ghazal poetry, the last couplet (Maqta) carries immense importance. In Ahmed Nadeem Qasmi's art of ghazal, one may observe the beautiful end couplet (Maqta) having variegated subjects and thought processes. His Maqta expresses his intellectual inclinations and aptness in a specific style. This research article strives to explore his diversity of thoughts and intellectual briefly. We read that his Maqta embraces a vast array of topics of various subjects such as existentialism, the concept of God, certainty and uncertainty of faith, empiricism and humanism. In his Maqta, one may come across a new world of meanings, the world of love, hate, meeting and departure of lover and beloved, and the agony of knowledge and ignorance. The helplessness of man to acquaint with life and its upheavals and his countering strategies.

Bitcoin Elektrik Tüketimi ile Küresel Ekonomik Politik Belirsizlik Endeksi (GEPU) Arasındaki İlişkinin Analizi

It is possible to define uncertainty as the variability of conditions, the ambiguity and obscurity of statements and events. Uncertainty, for whatever reason, affects the economy in different ways. Uncertainty causes people to be more concerned about their future income. Various estimation and methods have been developed in recent years to calculate the uncertainty, which is equivalent to the concept of uncertainty. These indices, in which economic and political uncertainties are calculated, appear as a form of calculation that also includes political discourses along with financial risk. The aim of this study is to examine the causality relationship between the Global economic political uncertainty index and Bitcoin electricity consumption. For this purpose, the Toda-Yamamoto causality test was applied using data from the period 2011:M7-2022:M1. According to the obtained Toda-Yamamoto causality test findings, Granger causality relationship has been determined both from the global economic-political uncertainty index to Bitcoin electricity consumption and from Bitcoin electricity consumption to the global economic-political uncertainty index.

РОЛЬ ІНТУЇЦІЇ В СТРУКТУРІ САМОРЕГУЛЯЦІЇ В УМОВАХ НЕВИЗНАЧЕНОСТІ

The article updates the issues of research on the topic of intuition, emotional intelligence and self-regulation in the context of decision-making under conditions of uncertainty, focusing on the limitations of modern scientific assets on this topic, which to a greater extent reflect the nature of the confrontation between rational and intuitive approaches. Instead, this article presents a view of the modern world оf BANI, which requires a modern man to be flexible and have a developed ability to adapt. The article reflects the empirical results that demonstrate the ambivalent nature of the manifestation of indicators of the intuitive-rational approach, emphasizing the urgent need for further development of modern research with the involvement of a wider sample, and changing the conditions of the experiment. Moreover, this paper describes theoretical components of the decision-making process, which demonstrate the presence of stress and uncertainty in the process of making even everyday decisions. The concept of subjective and objective uncertainty is revealed and their possible influence on our life and the decision-making process itself is highlighted. The characteristic influence of uncertainty on the self-regulation of the individual from the point of view of a modern war is also described. The absence of a modern conceptual apparatus that could clearly outline the concept of intuition and processes that can be called intuitive is emphasized. The results of the research of modern scientific schools demonstrate the tendency of individuals to an intuitive approach when making decisions in natural conditions. Theoretical assets demonstrating the connection between intuition, affective states and emotions, which reflect the main principles of information distortion in the decision-making process, are also highlighted.

Эвентуальность философии человека в обществе риска

Introduction. The article is devoted to the analysis of the eventuality of philosophy in the risk society through the anthropological consideration of the concepts of uncertainty, possibility, unpredictability, infinity. The main difficulty in risk analysis is that risk lies between rational and irrational, between certainty and uncertainty, between possibility and reality. Theoretical analysis. We are talking about the need for philosophical conceptualization of concepts, since the relations of definitions act as social and anthropological relations. The eventuality of the philosophy of risk in its semantic and temporal dimensions is analyzed. The unity of the concepts of eventuality, risk, society and time in their socio-historical transformation is considered. Risk and time are inextricably linked phenomena, which implies, along with the consideration of the semantics of risk, the analysis of the semantics of time. The paradoxical nature of risk is revealed. It has a temporal character and is defined as the foresight of the unpredictable and the reflexivity of the unknown. In risk there is a break in the continuum of rationality. The methodological basis of the article is socio-philosophical, philosophical-anthropological, riskological and historical-philosophical approaches to the study of the problem of a person in the risk society. Conclusions. It is concluded that the eventuality of human philosophy is revealed through the reflexivity of time, which in the risk society becomes an acceptable danger of temporal negativity of the possible – in action and in thinking.

Striking the balance: Sustainability and institutional transitions in the European Environment Agency

We look at how concepts of uncertainty and complexity undergo a series of balancing acts when moving between scientific research and policy. By questioning the prediction and control framework, uncertainty and complexity create both opportunities for new policy framings to emerge and challenges to the current role of institutions. We identify three balancing acts. First, there is the challenge of acknowledging the limits of the govern-ability of the future while retaining a role for governing agents. Second, the interface with policy leads to the selection of policy-relevant evidence that may be in tension with creating an inclusive space for the plurality of legitimate but often contrasting, perspectives at the interface with society. Third, there is a tension between the expectation that policy recommendations be formulated to solve existing problems and the new questions and processes that are opened when taking uncertainty and complexity into account. The paper takes as its case study the policy recommendations formulated by the European Environment Agency about sustainability transitions. Results show that the innovative and disruptive suggestions, which are made in the main text, are very much nuanced when it comes to policy recommendations and part of the transformative power of these concepts is lost through the balancing of opposing institutional needs. The value of the report lies not necessarily in the practical advice it formulates but in the more modest contribution of giving visibility to debates about uncertainty and complexity. Sustainability transition concepts serve as gatekeepers for new debates and new narratives to develop if sustained in time. Opportunities windows for new debates to emerge, however, may close fast.

Obesity and Type 2 Diabetes Mellitus Explained by the Free Energy Principle.

According to the free energy principle, all sentient beings strive to minimize surprise or, in other words, an information-theoretical quantity called variational free energy. Consequently, psychosocial “stress” can be redefined as a state of “heightened expected free energy,” that is, a state of “expected surprise” or “uncertainty.” Individuals experiencing stress primarily attempt to reduce uncertainty, or expected free energy, with the help of what is called an uncertainty resolution program (URP). The URP consists of three subroutines: First, an arousal state is induced that increases cerebral information transmission and processing to reduce uncertainty as quickly as possible. Second, these additional computations cost the brain additional energy, which it demands from the body. Third, the program controls which stress reduction measures are learned for future use and which are not. We refer to an episode as “good” stress, when the URP has successfully reduced uncertainty. Failure of the URP to adequately reduce uncertainty results in either stress habituation or prolonged toxic stress. Stress habituation reduces uncertainty by flattening/broadening individual goal beliefs so that outcomes previously considered as untenable become acceptable. Habituated individuals experience so-called “tolerable” stress. Referring to the Selfish Brain theory and the experimental evidence supporting it, we show that habituated people, who lack stress arousals and therefore have decreased average brain energy consumption, tend to develop an obese type 2 diabetes mellitus phenotype. People, for whom habituation is not the free-energy-optimal solution, do not reduce their uncertainty by changing their goal preferences, and are left with nothing but “toxic” stress. Toxic stress leads to recurrent or persistent arousal states and thus increased average brain energy consumption, which in turn promotes the development of a lean type 2 diabetes mellitus phenotype. In conclusion, we anchor the psychosomatic concept of stress in the information-theoretical concept of uncertainty as defined by the free energy principle. In addition, we detail the neurobiological mechanisms underlying uncertainty reduction and illustrate how uncertainty can lead to psychosomatic illness.

Responding to a Global Pandemic: Bureaucratic Caring Theory-Guided, Evidence-Based Approach in the Military Health System

The COVID-19 pandemic triggered a cascade of events, policy directives, and guidance. The U.S. Military Health System was leading the war, the first time in military history. Fulfilling its military medical readiness and beneficiary health-care delivery missions stimulated innovation. Applying the theory of bureaucratic caring revealed concepts of uncertainty, interconnectedness, choice-making, and emergence as determinants of growth, development, and future state for the Military Health System. New ways of thinking targeting health-care services laid the foundation for a radically different future. This article elucidates application of the theory to the Military Health System response to this global catastrophe.

Intuitionistic Fuzzy-Based Three-Way Label Enhancement for Multi-Label Classification

Multi-label classification deals with the determination of instance-label associations for unseen instances. Although many margin-based approaches are delicately developed, the uncertainty classifications for those with smaller separation margins remain unsolved. The intuitionistic fuzzy set is an effective tool to characterize the concept of uncertainty, yet it has not been examined for multi-label cases. This paper proposed a novel model called intuitionistic fuzzy three-way label enhancement (IFTWLE) for multi-label classification. The IFTWLE combines label enhancement with an intuitionistic fuzzy set under the framework of three-way decisions. For unseen instances, we generated the pseudo-label for label uncertainty evaluation from a logical label-based model. An intuitionistic fuzzy set-based instance selection principle seamlessly bridges logical label learning and numerical label learning. The principle is hierarchically developed. At the label level, membership and non-membership functions are pair-wisely defined to measure the local uncertainty and generate candidate uncertain instances. After upgrading to the instance level, we select instances from the candidates for label enhancement, whereas they remained unchanged for the remaining. To the best of our knowledge, this is the first attempt to combine logical label learning with numerical label learning into a unified framework for minimizing classification uncertainty. Extensive experiments demonstrate that, with the selectively reconstructed label importance, IFTWLE achieves statistically superior over the state-of-the-art multi-label classification algorithms in terms of classification accuracy. The computational complexity of this algorithm is On2mk, where n, m, and k denote the unseen instances count, label count, and average label-specific feature size, respectively.

Analytical Uncertainty in Animal Feed Laboratories: A Current Evaluation of AAFCO Proficiency Testing Data for Select Analytes

The animal feed regulatory community utilizes analytical variations (AVs) that account for the normal variability that occurs within and between laboratories. The AV was created using the Association of American Feed Control Officials (AAFCO) proficiency testing (PT) program results and represent the coefficient of variation times 2 (2 CV). This study was performed to assess the accuracy of the published AVs within the association’s Official Publication (OP) using AAFCO PT data from 2014 to 2020. This study also reevaluated the current AV values by applying the concept of the measurement uncertainties including the expanded uncertainty (U), Horwitz value, and 2 CV for the assessment of the label guarantees. Although greater variations were observed at lower concentrations, the majority of data points from the PT rounds showed an acceptable reproducibility for the select analytical methods except for cobalt, fat, fiber, moisture, and selenium where 2 CV was higher than the current AAFCO AV. Regression models were developed based on the 95% tolerance interval of expanded uncertainty and 2 CV and were validated using the 2019-2020 AAFCO PT data. The validation data fell within the expanded uncertainty and 2 CV model bounds indicating the new models were fit-for-purpose and accurately characterized current AAFCO PT data. The study results imply the AAFCO AV and its issues need to be better understood to improve an accuracy and traceability of the laboratory’s measurement and thus regulatory decisions to help animal feed producers and processors lower economic losses.

When do religion and science meet in uncertainty?

This study reports on the concept of uncertainty through the words of Agur in the Book of Proverbs about four observed objects, namely the way of an eagle in the air, the way of a serpent upon a rock, the way of a ship amid the sea, and the way of a man with a woman. The approach used to explore those words is the uncertainty theory by Heisenberg and the falsification method by Popper. It can be concluded that uncertainty is one of the themes of the Bible that unites science and religion in a dialogical manner. The finding strengthens the perspective that science can demonstrate and strengthen the Bible narrations through certain themes. The study also shows that the metaphysic statements of the holy book are not always normative and can be accepted as the source of knowledge supporting its own methodology.Intradisciplinary and/or interdisciplinary implications: This research strengthens the intersection of religion and science. Although the two methodologies are different, there are intersection points where the two can explain and confirm each other.

Robustness to rank reversal in pairwise comparison matrices based on uncertainty bounds

In the context of decision making, pairwise comparisons matrices (PCMs) based on a ratio scale are essential for deriving absolute preferences from relative comparisons. Such techniques are based on Subject Matter Experts (SMEs), which express their relative judgements on pairs of alternatives, providing pairwise comparison information, also in the case of incomplete or uncertain data, in order to obtain an absolute ranking about the alternatives. In this work, we propose a novel approach, complementary to measuring inconsistency, able to integrate and evaluate the concept of uncertainty in PCMs in order to verify the credibility of the final outcome. Such approach characterizes how SMEs’ uncertainty reflects into rank reversal. This is done via a novel optimization problem aiming to identify the smallest perturbations of the pairwise comparison values which result in an altered ranking of alternatives, e.g., reverting the ranking for at least a pair of alternatives.

Introduction: Severe Uncertainty in Science, Medicine, and Technology

Introduction: Severe Uncertainty in Science, Medicine, and Technology

Optimal planning of renewable energy systems with considering uncertainty and LPSP concept: A case study

Optimal planning of renewable energy systems with considering uncertainty and LPSP concept: A case study

A new method for control of nonlinear state-dependent switched systems

In this paper, a new method for the control of input-affine nonlinear switched systems is introduced. The system switching conditions are assumed to be state-dependent, rather than the simpler input-dependent case. The main contribution of this research is that the effects of switched dynamics are interpreted as a model uncertainty bounded within a polynomial of states norms, with unknown coefficients. In order to prevent extra conservativeness, coefficients are tuned adaptively, so that a minimal state-varying bound could be achieved. This is unlike the conventional sliding mode control (SMC) scheme, where the existence of a constant and usually large upper bound must be presumed. To address the challenge of coping with such a new concept of uncertainty, an extended form of the original adaptive fuzzy sliding mode control scheme is proposed. Adaptation laws are used to tune a fuzzy controller and also real-time estimation of the instantaneous bound of uncertainties. Closed-loop stability is guaranteed by proposing a group of multiple Lyapunov functions (MLF) with tunable parameters. Except for the mild condition that the largest difference between the magnitudes of the sub-manifolds of the switched system is bounded by a polynomial of states with uncertain coefficients, the proposed method has the distinct advantage that no information about the dynamic equations or switching conditions is required in the control design stage. The proposed method is applied to the two challenging case studies, depicting the outstanding effectiveness of the method.

Environmental, Technical, and Representational Uncertainty: A Framework for Making Sense of the Hidden Complexity of Educational Change

School systems are increasingly working to foster more ambitious learning environments and disrupt institutionalized educational inequities. But such efforts are complicated by a number of uncertainties—about the aims of schooling and how they might be achieved or measured—that suffuse educational organizations. Although there is general agreement that uncertainty is both pervasive and consequential in educational settings, as a field we lack a more unified analytic framework for making sense of this uncertainty. In this article, I seek to advance such a project by drawing on educational and organizational scholarship to identify three forms of uncertainty that pervade school systems. While two of these forms of uncertainty—environmental and technical—are well established in organizational theory, I develop the concept of representational uncertainty as a third form of uncertainty that is particularly impactful in schools. I show how these three forms of uncertainty manifest across different contexts, aims, and levels of school systems; how they interrelate; and how they must be strategically mitigated or fostered in the service of educational improvement.