Nonholonomic Research Articles

Education and the evolution of comparative advantage

We analyze the evolution of comparative advantage in 1,240 products from 49 low- and middle-income countries between 1995 and 2015. We show that countries with high education levels were more successful in developing comparative advantage in products unrelated to those they already exported. This effect is strongest for non-core products. In contrast, these countries did not develop comparative advantage in products that were intrinsically complex or education-intensive. These results are robust to corrections for specification errors, for institutional, infrastructure, and FDI-related factors, for regional specialization patterns, for key shifts in global trade rules, and for each economy's degree of industrial dynamism prior to 1995. These findings suggest that the key role of education when seeking to develop new industries is to help a country learn to manage unfamiliar challenges, and so overcome path dependence.

History Matters: The Institutionalization and Innovation Paradox in the Judiciary

The judiciary is a field lacking research in relation to its administration and innovation; however, different theoretical perspectives can be followed. This work reviews this trend while adding to it. An institutional perspective is presented, as is its explanatory potential. This perspective captures the context of the public sector; however, when analyzing its interpretation in terms of innovation, it is revealed to be doubly paradoxical. From the theoretical point of view, institutionalization focuses on the maintenance of processes, while innovation, gradually or abruptly, investigates their disruptions. Nevertheless, institutionalization can be observed as part of the sedimentation of innovation. Institutionalization is presented, in the context of innovation, as a selection mechanism that shapes such innovation. This paradox is presented under the review of organizational institutionalism vis-à-vis innovation and, for its unfolding, considers the adoption of innovation as an adaptation to the prevalent rationalized elements. This presentation is paralleled with the interpretation that innovation is limited by a structure that, sometimes rationalized, forms its trajectory. Considering the social function of the judiciary that is anchored in institutionalism, historical institutionalism is thus added, centrally placing the judiciary in the current institutional matrix and associating its path dependence with the dimensions of its innovation. Based on these outlines, propositions and a suggested agenda for future research are presented.

A case for historical institutionalist path dependence : Implications for the political history of the reign of Elizabeth II.

A case for historical institutionalist path dependence : Implications for the political history of the reign of Elizabeth II.

Policy Capacity for Urban Village Redevelopment in China: A Two-Case Case Study

Policy capacity is described as a determinant for effective policy implementation. Its contents vary according to modes of governance. Based on available academic studies, grey literature, and semi-structured interviews, this study empirically explores how urban village redevelopment has been carried out in two cities, Hangzhou and Guangzhou, through the lens of policy capacity. By contrasting policy outcomes and the manifestation of policy capacity at different levels in these two cities, we develop three arguments that contribute to our understanding of urban renewal and policy capacity. Firstly, the performance of any policy action is affected by the capacity of the central actor to develop and implement policies. Secondly, understanding the interactive logical between analytical, operational, and political capacities under different governance modes is the key to understanding the strengths and weaknesses of policy capacity in a specific sector. Shaped by local contexts and past experience, local governments are predisposed to path dependence in developing and deploying policy capacity in urban village redevelopment. Thirdly, the capabilities and resources needed to support policies are largely determined by policy problematization at the analytical level: the technique-based approach of policy capacity theory needs to complete the missing link between policy framing and ethical issues.

A variational approach to deriving Hamiltonian functions under non-holonomic constraints — the case of the Gaussian thermostats

The Hamiltonian function (H), if it exists, provides a powerful platform for studying the dynamics of constrained many-particle systems. For systems under holonomic constraints, H can be derived from the principle of least action (PLA) formulated in terms of a suitable set of generalized coordinates. In molecular dynamics (MD) simulations, where the system temperature often prescribes a non-holonomic constraint, the challenge is to find the system’s Hamiltonian. The Gaussian Isokinetic (GIK) thermostat, the first deterministic physics-preserving thermostat in MD, was derived from the principle of least constraint (PLC) in the early 1980s: its H, interestingly, was discovered almost 15 years later. A mathematically rigorous connection of the GIK Hamiltonian with PLA, however, has been missing until now. In this article, we adopt a variational approach to establish the equivalence of PLC with PLA for a class of non-holonomically constrained many-particle systems, and present the general formulation of the Euler–Lagrange equations of motion through time rescaling. Making use of the particular forms of the Lagrange multiplier obtained from the principle of least constraint, we derive H for the GIK and the Gaussian Isoenergetic thermostats.

Human resources in dentistry geographical distribution in Brazil and Colombia: Comparative analysis from the perspective of historical institutionalism

The Human Resource in Health constitutes one of the six core components of health systems, playing a crucial role in realizing the right to health and ensuring access and service quality. Additionally, institutional frameworks within each country, encompassing laws, decrees, political systems, and health system characteristics, exert a significant influence on HRH and, specifically, in Human Resources in Dentistry (HRD). Both Brazil and Colombia experienced neoliberal reforms in the 1990s, introducing new institutions within the existing model and altering the social, political, and economic dynamics of each country. This study aims to examine the impact of institutional arrangements stemming from the 1990s neoliberal reforms in Brazil and Colombia on HRDs, focusing on geographic distribution. Employing a comparative analysis and adopting a historical institutionalism perspective, the research relies on a methodology involving multiple case studies with embedded units. Results reveal that the neoliberal reforms represented critical junctures reshaping the social and economic policies of both nations. In this context, the reforms influenced wealth distribution in both countries, subsequently impacting the unequal geographical distribution of HRD. These effects were closely tied to factors such as labor flexibility and the unregulated, unplanned expansion of dentistry courses. These elements initiated positive feedback loops, characterized by path dependence and increasing returns, which have contributed to the institutionalization and persistence of these phenomena within the state and have become entrenched in HRDs over time.

Event-triggered prescribed-time consensus for nonholonomic multi-agent systems with external disturbances

This paper considers the prescribed-time event-triggered consensus for a class of nonholonomic multi-agent systems (MASs) with external disturbances. Firstly, the nonholonomic chained MASs are divided into two subsystems, and a switching control scheme is introduced. Secondly, a distributed prescribed-time continuous protocol is proposed to ensure that all agents reach average consensus within a prescribed finite-time. Moreover, to reduce the communication costs, an event-triggered consensus protocol is further established and some related theorems are given. In addition, the Zeno behaviour can be excluded by choosing parameters appropriately. Finally, two numerical examples are presented to demonstrate the effectiveness of the proposed protocols.

Adaptive formation control of nonholonomic multirobot systems with collision avoidance and connectivity maintenance

In this paper, an adaptive cooperative formation controller is developed to force a swarm of nonholonomic mobile robots with limited sensing ranges to move along the desired reference trajectory in a predetermined formation, while maintaining communication connectivity among the initial user-specified connected robots and guaranteeing no collision between the robots. Both kinematic models and dynamic systems with parametric uncertainties are discussed. The presence of parametric uncertainties is handled by adaptive control technique. A novel artificial potential function, which is based on a 4 times differential pseudo bump function, is constructed to achieve collision avoidance and connectivity maintenance. The control design is based on a fusion of potential function, adaptive backstepping technique, and Lyapunov synthesis. The cooperative formation controller is proven to be stable and can guarantee that there is no collision between any robots and the initial connectivity of the communication network can be always maintained. The proposed formation control approach is decentralized in the sense that the control action on each robot depends only on information from its neighbours and the desired trajectory of the group. Comparative simulation and experiment studies are performed to show the effectiveness of the proposed formation controller.

Manufacturing intelligentization and technological innovation: Perspectives on intra-industry impacts and inter-industry technology spillovers

This study empirically analyzes the impacts of manufacturing intelligentization on technological innovation using panel data from 29 manufacturing industries in China for the period 2012–2019. The research findings indicate that manufacturing intelligentization has significantly positive impacts on intra-industry technological innovation. Moreover, technological innovation exhibits path dependence, in which prior innovation accumulation is advantageous for current technological innovation. Furthermore, the spatial Durbin model indicates that intelligentization has both horizontal and vertical technology spillover effects on technological innovation. Specifically, the intelligentization of horizontal- and forward-linked industries has positive impacts on technological innovation in the focal industry. Additionally, technological innovation exhibits significant spatiotemporal dependence, as manifested by the negative spillover effects of prior technological achievements in other industries on current technological innovation in the focal industry.

Is economic growth enough to propel rehabilitation expenditures? An empirical analysis of country panel data and policy implications

PurposeRehabilitation is a set of services designed to increase functioning and improve wellbeing across the life course. Despite being a core part of Universal Health Coverage, rehabilitation services often receive limited public expenditure, especially in lower income countries. This leads to limited service availability and high out of pocket payments for populations in need of care. The purpose of this research was to assess the association between macroeconomic conditions and rehabilitation expenditures across low-, middle-, and high-income countries and to understand its implications for overall rehabilitation expenditure trajectory across countries.Materials and methodsWe utilized a panel data set from the World Health Organization’s Global Health Expenditure Database comprising the total rehabilitation expenditure for 88 countries from 2016 to 2018. Basic macroeconomic and population data served as control variables. Multiple regression models were implemented to measure the relationship between macroeconomic conditions and rehabilitation expenditures. We used four different model specifications to check the robustness of our estimates: pooled data models (or naïve model) without control, pooled data models with controls (or expanded naïve model), fixed effect models with all controls, and lag models with all controls. Log-log specifications using fixed effects and lag-dependent variable models were deemed the most appropriate and controlled for time-invariant differences.ResultsOur regression models indicate that, with a 1% increase in economic growth, rehabilitation expenditure would be associated with a 0.9% and 1.3% increase in expenditure. Given low baseline levels of existing rehabilitation expenditure, we anticipate that predicted increases in rehabilitation expenditure due to economic growth may be insufficient to meet the growing demand for rehabilitation services. Existing expenditures may also be vulnerable during periods of economic recession.ConclusionThis is the first known estimation of the association between rehabilitation expenditure and macroeconomic conditions. Our findings demonstrate that rehabilitation is sensitive to macroeconomic fluctuations and the path dependency of past expenditures. This would suggest the importance of increased financial prioritization of rehabilitation services and improved institutional strengthening to expand access to rehabilitation services for populations.

Is Green Transition in Europe Fostered by Energy and Environmental Efficiency Feedback Loops? The Role of Eco-Innovation, Renewable Energy and Green Taxation

Green transition is in the core of the European policy agenda to achieve the ambitious goal of climate neutrality following the launch of the European Green Deal. The cornerstone of the new growth strategy of Europe is resource efficiency which focuses on shifting to a more sustainable production paradigm by conserving scarce resources and by prioritizing enhanced environmental performance. Scattered efforts to investigate the drivers of resource efficiency measures have shed light on the key drivers, however, those consider resource efficiency measures in isolation neglecting for feedback loops influencing green transition. Therefore, we develop a conceptual framework to study green transition as a system of resource efficiency measures affected by feedback loops, path dependence, green technologies, and green policy tools. We mobilize the analysis by devising a unique balanced panel covering the EU-28 from 2010 through 2019, including policy efforts paving the way for green transition. Econometric results based on a system of fractional probit models, indicate that resource efficiency measures are intertwined via feedback loops, especially in the case of environmental efficiency. Green technologies affect green transition, however, rebound effects emerge in the case of energy efficiency. Past performance affects current levels pushing towards divergence. Evidence suggests that green taxation fosters energy efficiency whereas hinders environmental efficiency. The asymmetric operation of feedback loops and green taxation on energy and environmental efficiency highlights that horizontal policies hinder rather than foster green transition. This study contributes to SDGs 7, 12, 13 and 16.

Partial‐state feedback adaptive stabilization for a class of uncertain nonholonomic systems

SummaryIn this paper, we investigate the global adaptive stabilization problem via partial‐state feedback for a class of uncertain chained‐form nonholonomic systems with the dynamic uncertainty and nonlinear parameterization. The notions of Sontag's input‐to‐state stability (ISS) and ISS‐Lyapunov function, together with the changing supply rates technique are used to overcome the dynamic uncertainty. The nonlinear parameterization is well treated with the aid of the parameter separation technique. The discontinuous input‐to‐state scaling technique is employed in this procedure to derive the global stabilization controllers. Additionally, we develop a switching adaptive control strategy in order to get around the smooth stabilization burden associated with nonholonomic systems. The simulation results illustrate the efficacy of the presented algorithm.

Hierarchical path planner combining probabilistic roadmap and deep deterministic policy gradient for unmanned ground vehicles with non-holonomic constraints

Path planning plays a vital role in autonomous driving as it needs to guide the vehicle to achieve the target position without collision while satisfying the vehicle's non-holonomic constraints. A good path planner should be able to cope with sophisticated environments and try to make the planned path as short as possible. Traditional path planning methods when being applied on four-wheel vehicles may suffer from one of the following disadvantages including conflicting with non-holonomic constraints, far from close-optimal length solution, or easy to get stuck in specific environments. In this paper, a hierarchical path planning method for a four-wheel vehicle combining probabilistic roadmap (PRM) and deep deterministic policy gradient (DDPG) is proposed to address existing problems. In the upper level, PRM is used to generate a guidance path quickly, which doesn't consider the vehicle's non-holonomic constraints but gives the sketch of the path that helps the vehicle to jump out of some dilemmas in specific environments while maintaining a relatively short path distance. In the lower level, reinforcement learning, specifically DDPG, is used to optimize the guidance path generated by PRM considering multiple factors including non-holonomic constraints and obstacle avoidance. The proposed method is validated in four different environments including a simple map, an easy-to-stuck specific map, a maze-like complex map and an office-like complex map. Results show that the proposed method could generate a smooth path satisfying non-holonomic constraints while demonstrating desirable obstacle avoidance performance. The planned path of the proposed method is superior to that of both traditional and state-of-the-art methods in terms of path length and smoothness, which could be 1.3–12.9 % shorter and 2.6–52.1 % smoother in different environments.

What is quality in long covid care? Lessons from a national quality improvement collaborative and multi-site ethnography

BackgroundLong covid (post covid-19 condition) is a complex condition with diverse manifestations, uncertain prognosis and wide variation in current approaches to management. There have been calls for formal quality standards to reduce a so-called “postcode lottery” of care. The original aim of this study—to examine the nature of quality in long covid care and reduce unwarranted variation in services—evolved to focus on examining the reasons why standardizing care was so challenging in this condition.MethodsIn 2021–2023, we ran a quality improvement collaborative across 10 UK sites. The dataset reported here was mostly but not entirely qualitative. It included data on the origins and current context of each clinic, interviews with staff and patients, and ethnographic observations at 13 clinics (50 consultations) and 45 multidisciplinary team (MDT) meetings (244 patient cases). Data collection and analysis were informed by relevant lenses from clinical care (e.g. evidence-based guidelines), improvement science (e.g. quality improvement cycles) and philosophy of knowledge.ResultsParticipating clinics made progress towards standardizing assessment and management in some topics; some variation remained but this could usually be explained. Clinics had different histories and path dependencies, occupied a different place in their healthcare ecosystem and served a varied caseload including a high proportion of patients with comorbidities. A key mechanism for achieving high-quality long covid care was when local MDTs deliberated on unusual, complex or challenging cases for which evidence-based guidelines provided no easy answers. In such cases, collective learning occurred through idiographic (case-based) reasoning, in which practitioners build lessons from the particular to the general. This contrasts with the nomothetic reasoning implicit in evidence-based guidelines, in which reasoning is assumed to go from the general (e.g. findings of clinical trials) to the particular (management of individual patients).ConclusionNot all variation in long covid services is unwarranted. Largely because long covid’s manifestations are so varied and comorbidities common, generic “evidence-based” standards require much individual adaptation. In this complex condition, quality improvement resources may be productively spent supporting MDTs to optimise their case-based learning through interdisciplinary discussion. Quality assessment of a long covid service should include review of a sample of individual cases to assess how guidelines have been interpreted and personalized to meet patients’ unique needs.Study registrationNCT05057260, ISRCTN15022307.

Herglotz-type vakonomic dynamics and Noether theory of nonholonomic systems with delayed arguments

The Herglotz-type vakonomic dynamics of nonholonomic constrained systems with delayed arguments and its Noether theory are studied in this paper. First of all, the Herglotz-type equations of time-delayed vakonomic dynamics for nonholonomic systems are established, and the Herglotz-type local extremal equations are given. Secondly, on the basis of derivation of the variational formulas of Hamilton–Herglotz action with time delay, the Herglotz-type Noether symmetry criteria for time-delayed vakonomic dynamics are investigated. Thirdly, the Herglotz-type Noether’s theorems and inverse theorems for time-delayed vakonomic dynamics of nonholonomic systems are deduced. Finally, an example is presented to demonstrate the application of the results.

How is the path produced and sustained? Path-dependent college education expansion and underlying liberal rule in Korea

Abstract The conventional policy analyses with a path-dependent framework are featured by sequential causation composed of analytically two distinct phases: path production that occurs through a significant policy change at critical junctures and the subsequent path reproduction. This paper explores one policy area where the two-phase framework falls short in explaining path-making and maintenance – college education expansion in Korea. We argue that the shortcomings of the two-phase model can potentially be overcome by incorporating the underlying rule of the countries into the model. We identify the underlying rule relying on Esping-Andersen’s welfare regimes to highlight the political underpinnings of the countries. We show that the underlying liberal rule is a fundamental causal force behind the production and reproduction of college education expansion in Korea, using qualitative comparative analysis. Our framework based on the underlying rule provides a richer understanding of path dependency.

Entrepreneurial prototyping: the role of purpose, prototype recycling, and skills bricolage

AbstractThis paper explores how entrepreneurs engage in prototyping as part of the venture development process. We conduct a qualitative field study of 156 instances of prototyping across eight venture development processes. From a theoretical perspective, we build on alternative and complementary views of entrepreneurial action and their implicit modes of prototyping, emphasizing experimentation and transformation. Our findings identify three important themes in the prototyping process. These include purposes where the entrepreneurs use prototyping for either flexible experimentation or directed transformation. Further, the entrepreneurs predominantly engage in prototype recycling and skills bricolage when prototyping. Accordingly, the studied entrepreneurs carefully navigate purpose and resource investments in prototyping, making extensive use of their existing resource base of skills and prototypes. After noting the positive aspects of prototyping, we also discuss the potentially destructive outcomes of misapplied prototyping in the form of prototyping myopia and problematic path dependencies of the different ways of prototyping.

Enhanced path planning algorithm via hybrid WOA-PSO for differential wheeled mobile robots

This study introduces an enhanced algorithm for global path planning of Differential Wheeled Mobile Robots (DWMRs) that merges the Whale Optimization Algorithm (WOA) and Particle Swarm Optimization (PSO). This hybrid strategy, termed HWPSO, is designed to leverage WOA's exploration strength with PSO's efficient exploitation, specifically targeting the challenges of non-holonomic constraints in complex terrains. To validate the effectiveness of the proposed algorithm, its performance is evaluated across five diverse environments and compared against PSO, WOA, and Grey Wolf Optimization which is widely used for mobile robot path planning. Moreover, the comparison broadens to encompass four established environments from the literature where algorithms based on firefly, ant colony, A*, and other PSO variants have previously exhibited optimal performance. Additionally, a new environment is introduced to analyze the efficacy of the proposed approach for path planning for two DWMRs. Simulation results consistently demonstrate the superiority of the proposed HWPSO, manifesting performance improvements of up to 19.3% for path length reduction and up to 12.7% for DWMR travel duration reduction when compared to other methods. This underscores the efficacy of the proposed hybrid approach in achieving enhanced path planning outcomes for DWMRs in diverse scenarios.

Nudging Sustainable Development: Reviewing Energy Transition and Economic Development

Recently, as more countries and regions have embarked on the path of energy transition, the speed and manner of economic development have been influenced in varying degrees. However, the relationship between energy transition and economic development remains unclear, as research conclusions are inconsistent. The aim of this study is to systematically examine the relationship between energy transition and economic development using the literature review approach. This study selected 102 studies from Scopus that explicitly address energy transition and economic development as our final sample for this investigation, aiming to clarify the current research status on factors, barriers, and pathways of energy transition, and discuss related theories about energy transition. The results indicate a significant increase in research volume on this topic over the past four years, with nearly half of the studies focusing on cross-regional countries or economic entities. The sampled literature reveals various relationships between economic development and energy transition, including one-way promotion, one-way inhibition, bidirectional causality, and ineffectiveness. Factors influencing energy transition include technology, financial support, environmental governance, human capital, taxation, rents, and foreign direct investment (FDI). The main obstacles to energy transition lie in the scarcity of environmental resources, path dependence, and uneven development. Based on these research findings, this study discusses prospects and potential directions for future studies.

Assessing Path Dependency in Vietnam's Healthcare Legal Framework: Exploring Public-Private Collaboration in Ho Chi Minh City during the COVID-19 Crisis.

The COVID-19 pandemic prompted a nudge for public-private cooperation in healthcare to rapidly cope with limited resource. However, Vietnam's historical reliance on a public healthcare system, combined with a traditional emphasis on socialization in the Polanyian sense, hindered the swift integration of the private sector. This research investigates path dependency in Vietnam's public health sector, using theories including path dependency, Karl Polanyi's double movement with legal analysis method to analyze the interplay of historical decisions, and socialist policies in healthcare. Recognizing these institutional and market governance flaws, a deeper understanding of the role of law becomes vital in crafting strategies for a more resilient and sustainable healthcare system in Vietnam. In this article, Ho Chi Minh City is chosen as a case study due to its notable mix of public-private healthcare facilities and its status as a leading area in infection cases during the third COVID-19 wave. The article suggests that there should be a change in the way public and private sectors work together, one that is more in line with market-driven solutions which requires solid legal framework for cooperation beyond merely mobilizing resources.