This work investigates the finite-time control problem for a nonlinear four-tank cross-coupled liquid level system by the port-controlled Hamiltonian model. A fixed-free methodology is exhibited which can be used to simplify the controller design procedure. To get an adjustable convergent gain of the finite-time control, a feasible technique named damping normalization is proposed. A novel parameter autotuning algorithm is given to clarify the principle of choosing parameters of the PCH method. Furthermore, a finite-time controller is (...) designed by a state-error desired Hamiltonian function, and the relationship between the settling time and a parameter is given, which can be applied in practical engineering easily to adjust the settling time according to the industrial need. Finally, simulation and experimental results verify the effectiveness of the proposed algorithm. (shrink)

The aim of this paper is to analyze the basis for the moral obligation to remember. As the moral relation to the past is primarily a matter of shared identity, the kind of obligation in question splits into two related issues, namely, that of political, state-oriented and state-organized memory on which the political identity rests and that of memory labour grounded in social identities based in shared, time-extended projects. Drawing upon tensions between these two, I discuss time (...) class='Hi'>control and the accumulation of identity as central to memory labour and, referring to John Zerzan’s critique of symbolical roots of power, pinpoint the moral basis of such an accumulation. On the basis of this, I argue for nesting the duty to remember in acknowledging the agent’s recognition of the relatedness and dependency of their agency and possibilities of flourishing which can be obtained thanks to adjusting the field of the virtue of practical wisdom so that it includes members of the time-extended community. (shrink)

As a part of job resources, work time control is essential for innovation. We examine how work time control impacts knowledge employees’ innovation in the workplace. A two-stage study was conducted to verify the mediating and moderating processes. In Study 1, adopting the job demands–resources model as a theoretical framework, we conducted a laboratory test to find the relation between work time control, job engagement, job burnout, and innovation, and verified the path between work (...) time control and innovation. In Study 2, drawing on the job demands–resources model verified by Study 1 and self-regulation theory, it is proposed that during the psychological process in the workplace, job engagement plays a mediating role, and the vocational delay of gratification plays a moderating role between work time control and innovation. A total of 254 knowledge employees from diverse organizations participated in the survey study. After taking demographic variables, job demands, and neuroticism as control variables, the results showed that job engagement would mediate the relationship between work time control and innovation. A higher level of delay of gratification buffered the effect of a higher level of work time control on innovation. All these findings verified and expanded knowledge on work time control and innovation literature, showing that work time control is important for innovation. Based on Chinese cultural background, managers should offer employees the opportunity to conduct self-control training and encourage them with great freedom to foster employee innovation. (shrink)

The formation control issue for a group of underactuated unmanned surface vehicles is discussed in the paper, and a staged finite-time control strategy for the USVs is proposed. Firstly, we try to steer each USV to its own starting point in the formation for a limited time, under the initial condition that each of these vehicles is parked at random. To deal with the nonholonomic behavior of the system, the dynamics of the USV is transformed into (...) cascade systems. Then, the finite-time controller is designed for each vehicle based on homogeneity theory. After each USV reaches its own starting point with desired orientation, the model of the vehicle is decomposed into two subsystems under the Serret-Frenet frame. In order to maintain the formation pattern, two finite-time distributed controllers are developed for the surge subsystem and the yaw subsystem, respectively. The settling time for the staged control strategy is limited. Numerical simulations are carried out to illustrate the effectiveness of the proposed formation control strategy. (shrink)

We present an initial and elementary investigation of the formal specification and mechanical verification of programs that interact with environments. We describe a formal, mechanically produced proof that a simple, real time control program keeps a vehicle on a straightline course in a variable crosswind. To formalize the specification we define a mathematical function which models the interaction of the program and its environment. We then state and prove two theorems about this function: the simulated vehicle never gets (...) farther than three units away from the intended course and homes to the course if the wind ever remains steady for at least four sampling intervals. (shrink)

David Albert explains why we can typically influence the future but not the past by appealing to an initial low-entropy state of the universe. And he argues that in the rare cases where we can influence the past, we cannot use this influence to knowingly gain future rewards: so it does not constitute control. I introduce an important new case in which Albert's account implies we can not only influence the past but control it: a case where our (...) actions in the present are reliably correlated with several events in the present and past. To deal with such cases, we need to appeal to epistemic conditions on deliberation: being agents requires our decisions being epistemically undetermined at the time we make them. In a world with the past-hypothesis, this implies that deliberation will typically come prior to decision. Once deliberation in this direction is established, correlations towards the past cannot then be exploited for control. To explain why we cannot effectively control the past, we need to appeal to deliberation, whether as part of a defence of Albert's account, or used independently to explain the asymmetry of control. (shrink)

Self-control is integral to successful human agency. Without it we cannot extend our agency across time and secure central social, moral, and personal goods. But self-control is not a unitary capacity. In the first part of this paper we provide a taxonomy of self-control and trace its connections to agency and the self. In part two, we turn our attention to the external conditions that support successful agency and the exercise of self-control. We argue that (...) what we call moral security is a critical foundation for agency. Parts three and four explore what happens to agency when moral security is lacking, as in the case of those subject to racism, and those living in poverty. The disadvantages suffered by those who are poor, in a racial minority or other oppressed group, or suffering mental illness or addiction, are often attributed to a lack of individual self-control or personal responsibility. In particular, members of these groups are often seen as irresponsibly focused on short-term pleasures over long-term good, a view underwritten by particular psychological theories of self-control. We explore how narratives about racism and poverty undermine moral security, and limit and distort the possibility of synchronic and diachronic self-control. Where moral security is undermined, the connection between self-control and diachronic goods often fails to obtain and agency contracts accordingly. We close with some preliminary reflections on the implications for responsibility. (shrink)

The production of good sound generation in the violin is a complex task that requires coordination and spatiotemporal control of bowing gestures. The use of motion-capture technologies to improve performance or reduce injury risks in the area of kinesiology is becoming widespread. The combination of motion accuracy and sound quality feedback has the potential of becoming an important aid in violin learning. In this study, we evaluate motion-capture and sound-quality analysis technologies developed inside the context of the TELMI, a (...) technology-enhanced music learning project. We analyzed the sound and bow motion of 50 participants with no prior violin experience while learning to produce a stable sound in the violin. Participants were divided into two groups: the experimental group received real-time visual feedback both on kinematics and sound quality, while participants in the control group practiced without any type of external help. An additional third group of violin experts performed the same task for comparative purposes. After the practice session, all groups were evaluated in a transfer phase without feedback. At the practice phase, the experimental group improved their bowing kinematics in comparison to the control group, but this was at the expense of impairing the sound quality of their performance. At the retention phase, the experimental group showed better results in sound quality, especially concerning control of sound dynamics. Besides, we found that the expert group improved the stability of their sound while using the technology. All in all, these results emphasize the importance of feedback technologies in learning complex tasks, such as musical instrument learning. (shrink)

Organizations have long struggled to find ways to reduce the occurrence of unethical behaviors by employees. Unfortunately, time theft, a common and costly form of ethical misconduct at work, has been understudied by ethics researchers. In order to remedy this gap in the literature, we used the theory of planned behavior (TPB) to investigate the antecedents of time theft, which includes behaviors such as arriving later to or leaving earlier from work than scheduled, taking additional or longer breaks (...) than is acceptable, and on-the-job daydreaming. We surveyed 135 employed undergraduate business students regarding the TPB variables at Time 1. Two months later, participants reported the frequency they engaged in time theft since Time 1. Results indicate that behavioral, normative, and control beliefs significantly predicted attitudes, subjective norms, and perceived behavioral control, respectively. Attitudes, subjective norms, and perceived behavioral control, in turn, were significantly related to time theft intentions, which predicted later enactment of time theft. Thus, employers can decrease time theft by primarily focusing on altering employees’ attitudes toward time theft, followed by reducing social pressures to engage in it, and lastly, by implementing organizational practices that make it difficult to commit time theft. (shrink)

The problem of finite-time tracking control is discussed for a class of uncertain nonstrict-feedback time-varying state delay nonlinear systems with full-state constraints and unmodeled dynamics. Different from traditional finite-control methods, a C 1 smooth finite-time adaptive control framework is introduced by employing a smooth switch between the fractional and cubic form state feedback, so that the desired fast finite-time control performance can be guaranteed. By constructing appropriate Lyapunov-Krasovskii functionals, the uncertain terms produced (...) by time-varying state delays are compensated for and unmodeled dynamics is coped with by introducing a dynamical signal. In order to avoid the inherent problem of “complexity of explosion” in the backstepping-design process, the DSC technology with a novel nonlinear filter is introduced to simplify the structure of the controller. Furthermore, the results show that all the internal error signals are driven to converge into small regions in a finite time, and the full-state constraints are not violated. Simulation results verify the effectiveness of the proposed method. (shrink)

In this paper, a timed modal logic L c is presented for the specification and verification of real-time systems. Several important results for L c are discussed. First we address the model checking problem and we show that it is an EXPTIME-complete problem. Secondly we consider expressiveness and we explain how to express strong timed bisimilarity and how to build characteristic formulas for timed automata. We also propose a compositional algorithm for L c model checking. Finally we consider several (...) control problems for which L c can be used to check controllability. (shrink)

It has been argued that the explanation of self-control requires positing special motivational powers. Some think that we need will-power as an irreducible mental faculty; others that we need to think of the active self as a dedicated and depletable pool of psychic energy or – in today more respectable terminology – mental resources; finally, there is the idea that self-control requires postulating a deep division between reason and passion – a deliberative and an emotional motivational system. This (...) essay argues that no such special motivational powers are necessary. Yet, at the same time, self-control does powerfully illustrate the importance of a feature of the mind. What it illustrates, I argue, is the importance of the mental activity of attention in the control of all action. It is by appeal to this mental activity that we can dispense with special motivational powers. If we think of Humeanism as the view that there is fundamentally only one kind of motivational system and that all action is based in that system, then this essay contributes to a defense of Humeanism. On the other hand, the essay also shows that any model of agency in terms of only beliefs and desires, motivational and representational states, or preferences and credences is incomplete. A different conception of Humeanism as the view that every mental state is either motivational, representational, or a combination of them, is false. (shrink)

This paper proposes a novel robust fixed-time control for the robot manipulator system with uncertainties. Based on the uniform robust exact differentiator algorithm, a robust control term is constructed. Then, a robust fixed-time inverse dynamics control is proposed. For the proposed control method, the fixed-time stability of a closed-loop system with uncertainties is strictly proved. The newly proposed method exhibits the following two attractive features. First, the proposed control scheme extends the existing (...) fixed-time IDC for the robot manipulator system to the robust control scheme. Second, the proposed method is strictly nonsingular rather than the commonly used approximate approach. Simulation result demonstrates the effectiveness of the proposed control scheme. (shrink)

In this paper, finite-time tracking problem of nonholonomic mobile robots for a moving target is considered. First of all, polar coordinates are used to characterize the distance and azimuth between the moving target and the robot. Then, based on the distance and azimuth transported from the sensor installed on the robot, a finite-time tracking control law is designed for the nonholonomic mobile robot by the switching control method. Rigorous proof shows that the tracking error converges to (...) zero in a finite time. Numerical simulation demonstrates the effectiveness of the proposed control method. (shrink)

Examples of how LTP and LTD can control adaptively-timed learning that modulates attention and motor control are given. It is also suggested that LTP/LTD can play a role in storing memories. The distinction between match-based and mismatch-based learning may help to clarify the difference.

This article is related to the issue of fixed-time synchronization of different dimensional complex network systems with unknown parameters. Two suitable adaptive controllers and dynamic parameter estimations are proposed such that the complex network driving and response systems can be synchronized in the settling time. Based on fixed-time control theory and Lyapunov functional method, novel sufficient conditions are provided to guarantee the synchronization within the fixed times, and the settling times are explicitly evaluated, which are independent (...) of the initial synchronization errors. Finally, a numerical example is given to illustrate the effectiveness of the proposed control algorithms. (shrink)

Wnt signalling through β‐catenin plays a pivotal role during embryonic pattern formation, cell fate determination and tissue homeostasis in the adult organism. In the skin, as in many other tissues, Wnt/β‐catenin signalling can control lineage determination and differentiation. However, it was not known whether Wnt/β‐catenin signalling is an immediate regulator of the stem cell niche in skin tissue. A recent publication now provides evidence that Wnt/β‐catenin signalling exerts a direct effect on the stem cell compartment by inducing quiescent stem (...) cells to enter the cell cycle during early stages of hair follicle regeneration. In addition, the authors demonstrate that β‐catenin is required for maintenance of the stem cell pool in the tissue.1 The data suggest that a gradient in Wnt/β‐catenin activity levels can induce different responses within distinct cell populations reflected by activation of distinct transcriptional profiles. BioEssays 28:1–5, 2006. © 2005 Wiley Periodicals, Inc. (shrink)

Control measures directed at carriers of multidrug-resistant organisms are traditionally approached as a trade-off between public interests on the one hand and individual autonomy on the other. We propose to reframe the ethical issue and consider control measures directed at carriers an issue of solidarity. Rather than asking “whether it is justified to impose strict measures”, we propose asking “how to best care for a person’s carriership and well-being in ways that do not imply an unacceptable risk for (...) others?”. A solidarity approach could include elevating baseline levels of precaution measures and accepting certain risks in cases where there is exceptionally much at stake. A generous national compensation policy that also covers for costs related to dedicated care is essential in a solidarity approach. An additional benefit of reframing the questions is that it helps to better acknowledge that being subjected to control measures is a highly personal matter. (shrink)

This paper investigates the fixed-time coordinated control problem of six-degree-of-freedom dynamic model for multiple spacecraft formation flying with input quantization, where the communication topology is assumed directed. Firstly, a new multispacecraft nonsingular fixed-time terminal sliding mode vector is derived by using neighborhood state information. Secondly, a hysteretic quantizer is utilized to quantify control force and torque. Utilizing such a quantizer not only can reduce the required communication rate but also can eliminate the control chattering phenomenon (...) induced by the logarithmic quantizer. Thirdly, a 6-DOF fixed-time coordinated control strategy with adaptive tuning laws is proposed, such that the practical fixed-time stability of the controlled system is ensured in the presence of both upper bounds of unknown external disturbances. It theoretically proves that the relative tracking errors of attitude and position can converge into the regions in a fixed time. Finally, a numerical example is exploited to show the usefulness of the theoretical results. (shrink)

This paper presents an adaptive neural tracking control approach for a two-joint robotic manipulator with unknown time-varying delays. In order to work out the effect of unknown time-varying delays on the two-joint robotic manipulator, the appropriate Lyapunov–Krasovskii functionals and separation technology are chosen to settle this matter. The neural networks work as an approximator that has the advantage of estimating the unknown function in the system. In this paper, Lyapunov stability analysis can prove that all signals of (...) the closed-loop system are semiglobal uniformly ultimately bounded and the tracking error can converge to a compact neighborhood with respect to zero. The simulation consequences demonstrate the availability of the feedforward control approach. (shrink)

This work is devoted to studying the stochastic stabilization of a class of neutral-type complex-valued neural networks with partly unknown Markov jump. Firstly, in order to reduce the conservation of our stability conditions, two integral inequalities are generalized to the complex-valued domain. Secondly, a state-feedback controller is designed to investigate the stability of the neutral-type CVNNs with H ∞ performance, making the stability problem a further extension, and then, the stabilization of the CVNNs with H ∞ performance is investigated through (...) a sampling-based event-triggered control for the first time that the transmission event is not triggered except when it violates the event-triggered condition. Finally, two examples are given to illustrate the validity and correctness of our obtained theorems. (shrink)

Heterochronic genes control the timing of developmental programs. In C. elegans, two key genes in the heterochronic pathway, lin-4 and let-7, encode small temporally expressed RNAs (stRNAs) that are not translated into protein. These stRNAs exert negative post-transcriptional regulation by binding to complementary sequences in the 3′ untranslated regions of their target genes. stRNAs are transcribed as longer precursor RNAs that are processed by the RNase Dicer/DCR-1 and members of the RDE-1/AGO1 family of proteins, which are better known for (...) their roles in RNA interference (RNAi). However, stRNA function appears unrelated to RNAi. Both sequence and temporal regulation of let-7 stRNA is conserved in other animal species suggesting that this is an evolutionarily ancient gene. Indeed, C. elegans, Drosophila and humans encode at least 86 other RNAs with similar structural features to lin-4 and let-7. We postulate that other small non-coding RNAs may function as stRNAs to control temporal identity during development in C. elegans and other organisms. BioEssays 24:119–129, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

Journal of Social Philosophy, Volume 53, Issue 2, Page 221-238, Summer 2022.

Postmodernity has brought new forms of social control which are exercised through new forms of communication. Paradoxically, however, postmodernity also seemed to be heading towards the exaltation of the individual in their absolute freedom. The 20 th century pushed, in the name of science and progress, the secularization of Western societies, often distancing people from their traditional community ties, including ties to the ecclesial community. Thus, the postmodern individual initially appeared free of ancestral community pressures. However, subtle new forms (...) of social control have replaced traditional ones. Mechanisms such as social media, new forms of work and sexual exploitation, or the impossibility of maintaining privacy in the face of the power of private and public corporations, thus expose the individual to the asocial elements. Frequently, these new social control mechanisms (a clear example being the leadership of the WHO in the policies implemented worldwide during the COVID-19 pandemic) are presented to us not as repressive, but scientifically and paternally protective. In this context, the vindication of religious freedom and the community experience of faith represent decisive touchstones for the vitality and validity of a social and political order in which the personal being is truly the highest value. The authors of this monograph are professors, some of them with twenty or thirty years of university teaching, others halfway between Generation X and Y, but all with a deep vocation as teachers called to understanding the world around them. A vocation to collaborate with their students so that the seed of love for the knowledge of reality and the joyful experience of contact with the truth may bear fruit in them. Such an experience only makes sense as a shared experience. And this is what the authors of this monograph usually do: share their concerns, worries, and research. In formal terms, this shared experience has been developing in recent times under the mantle of research projects such as the one that forms the basis of this issue of _Scientia et Fides_: “Social Control, Postmodernism and Political Community” (COSOPOC). Sharing the results of their research is also a way of inviting the specialized public to this experience without forgetting that the first circle of this community work is formed by the students themselves, whom this monograph aims to serve as a stimulus in their personal trajectories as students, as future professionals and, above all, as people in charge of their actions and responsible and capable of facing the worrying challenges that face us all. (from the Editorial). (shrink)

Many plants are adapted to flower at particular times of year, to ensure optimal pollination and seed maturation. In these plants flowering is controlled by environmental signals that reflect the changing seasons, particularly daylength and temperature. The response to daylength varies, so that plants isolated at higher latitudes tend to flower in response to long daylengths of spring and summer, while plants from lower latitudes avoid the extreme heat of summer by responding to short days. Such responses require a mechanism (...) for measuring time, and the circadian clock that regulates daily rhythms in behaviour also acts as the timer in the measurement of daylength. Plants from high latitudes often also show an extreme response to temperature called vernalisation in which flowering is repressed until the plant is exposed to winter temperatures for an extended time. Genetic approaches in Arabidopsis have identified a number of genes that control vernalisation and daylength responses. These genes are described and models presented for how daylength might regulate flowering by controlling their expression by the circadian clock. BioEssays 22:38–47, 2000. ©2000 John Wiley & Sons, Inc. (shrink)

The well-established pattern of Executive expansionism and limited oversight of Executive action in times of terrorism is problematic from the civil libertarian point of view. How to limit such action has been the subject of much scholarship, a large amount of which focuses on perceptions of institutional competence rather than effectiveness. For the authors, the effective control of security-focused state action is to be judged by the extent to which it consists only of action that is necessary and proportionate (...) and thereby strikes an appropriate balance between security exigencies and individual rights. This article, written and structured in dialectic form, presents competing perspectives on effective oversight mechanisms: on the one hand, an extra-constitutionalism perspective, proposing a limited role for the Judiciary and emphasizing the need for legislative and democratic controls; and on the other, an argument for judicial muscularity. (shrink)

This paper investigates the leaderless and leader-follower time-varying formation design and analysis problems for a group of networked agents subject to discontinuous communications. Firstly, a leaderless time-varying formation control protocol is proposed via the intermittent control strategy, where the control input of each agent is constructed by the distributed local state information and formation instructions in the communication time unit, but it is zero in the noncommunication time unit. Then, an explicit formulation of (...) the formation center function is determined to describe the formation movement trajectory of the whole networked agents. Leaderless time-varying formation design and analysis with discontinuous communications are given in the form of linear matrix inequalities. Moreover, the main results of the leaderless cases are extended to the leader-follower cases. Finally, two numerical examples are provided to illustrate the theoretical results of leaderless and leader-follower cases, respectively. (shrink)