Search Results (149)

Geographic disparities threaten equitable access for children to health-promoting safe green spaces, and quality early education in the communities in which they live and grow. To address gaps in the field, we integrated the fields of developmental psychology, public health, and environmental science to examine, at the population level, associations between the environmental burden, socioeconomic vulnerability, and kindergarten readiness in a diverse urban county. Three administrative datasets were integrated through an early childhood data sharing research partnership in Miami-Dade County. The Bruner Child Raising Vulnerability Index, the five domains of the Environmental Burden module from the Environmental Justice Index, and public school kindergarten readiness scores were aggregated at the census tract level. Analysis of variance and multiple regression analyses found associations between socioeconomic vulnerability and race/ethnicity. The socioeconomic vulnerability levels were highest in census tracts with a higher percentage of Black residents, compared to all other races/ethnicities. Areas of greater social vulnerability had lower kindergarten readiness and a higher environmental burden. A higher environmental burden predicted lower kindergarten readiness scores above and beyond race/ethnicity and socioeconomic vulnerability. The findings advance our understanding of global challenges to sustainable healthy child development, such as the persistence of a disproportionate environmental burden and inequitable access to resources such as green spaces and early education programs. The present study results can inform community health improvement plans to reduce risk exposures and promote greater access to positive environmental and educational resources for all children. Full article

As with wind turbines, marine tidal turbines are expected to be deployed in arrays of multiple turbines. To optimize these arrays, a more profound understanding of the interactions between turbines is necessary. This paper employs the Actuator Line Method alongside the Lattice Boltzmann Method and Large Eddy Simulation to develop a numerical model of tidal turbine arrays. It studies a vertical-axis turbine manufactured by HydroQuest/CMN that is equipped with two counter-rotating columns, each comprising two rotors. The ambient turbulence and upstream velocity profiles correspond to the characteristics of a tidal site such as the Alderney Race. Six turbine layouts are modeled: three aligned layouts with three turbines and three staggered layouts with four turbines. The spacing between turbines varies depending on the layout. This study yields several observations regarding array configuration. A minimum distance of 300 m, or $12D_{eq}$, between aligned turbines is necessary for full wake recovery. At shorter distances, the accumulation of velocity deficits significantly decreases the efficiency of the third turbine in the array. Pairs of counter-rotating vortices are observed in the wake of turbines. The evolution of these vortices and their influence on the wake depend greatly on the array configuration. An optimal configuration is observed in which the overall averaged power is not impaired by the interactions. Full article

Under complex operating conditions, vibration signals from rotating machinery often exhibit non-stationary characteristics with non-proportional and closely spaced instantaneous frequency (IF) components. Traditional time–frequency analysis (TFA) methods struggle to accurately extract such features due to energy leakage and component mixing. In response to these issues, an enhanced time–frequency analysis approach, termed Local Entropy Selection Scaling–Reassigning Chirplet Transform (LESSRCT), has been developed to improve the representation accuracy for complex non-stationary signals. This approach constructs multi-channel time–frequency representations (TFRs) by introducing multiple scales of chirp rates (CRs) and utilizes a Rényi entropy-based criterion to adaptively select multiple optimal CRs at the same time center, enabling accurate characterization of multiple fundamental components. In addition, a frequency reassignment mechanism is incorporated to enhance energy concentration and suppress spectral diffusion. Extensive validation was conducted on a representative synthetic signal and three categories of real-world data—bat echolocation, inner race bearing faults, and wind turbine gearbox vibrations. In each case, the proposed LESSRCT method was compared against SBCT, GLCT, CWT, SET, EMCT, and STFT. On the synthetic signal, LESSRCT achieved the lowest Rényi entropy of 13.53, which was 19.5% lower than that of SET (16.87) and 35% lower than GLCT (18.36). In the bat signal analysis, LESSRCT reached an entropy of 11.53, substantially outperforming CWT (19.91) and SBCT (15.64). For bearing fault diagnosis signals, LESSRCT consistently achieved lower entropy across varying SNR levels compared to all baseline methods, demonstrating strong noise resilience and robustness. The final case on wind turbine signals demonstrated its robustness and computational efficiency, with a runtime of 1.31 s and excellent resolution. These results confirm that LESSRCT delivers robust, high-resolution TFRs with strong noise resilience and broad applicability. It holds strong potential for precise fault detection and condition monitoring in domains such as aerospace and renewable energy systems. Full article

Autonomous race driving has emerged as a challenging domain for reinforcement learning (RL) applications, requiring high-speed control while adhering to strict safety constraints. Existing RL-based racing methods often struggle to balance performance and safety, with limited adaptability in dynamic racing scenarios with multiple opponent vehicles. The high-dimensional state space and strict safety constraints pose significant challenges for efficient learning. To address these challenges, this paper proposes an integrated RL framework that combines three novel components: (1) a state mapping mechanism that dynamically transforms raw track observations into a consistent representation space; (2) an action mapping technique that rigorously enforces physical traction constraints; and (3) a safe exploration guidance method that combines conservative controllers with RL policies, significantly reducing off-track incidents during training. Extensive experiments conducted in our simulation environment with four test tracks demonstrate the effectiveness of our approach. In time trial scenarios, our method improves lap times by 12–26% and increases the training completion rate from 33.1% to 78.7%. In competitive racing, it achieves a 46–51% higher average speed compared to baseline methods. These results validate the framework’s ability to achieve both high performance and safety in autonomous racing tasks. Full article

While Charles Hirschkind presents an ambiguous response to the question “Is There a Secular Body?”, this study argues that, in the Turkish context, a secular body not only exists but is also conducive to racializing practices. Drawing on ethnographic insights from Istanbul’s nightlife—differing from previous research which focused on spatial differentiation and gentrification—this article examines how nightlife spaces intersect with secular subjectivity and the implications of these intersections. By broadening understandings of race and racialization in Turkish genealogy, the secular body is understood to emerge as a site of struggle where modernity and anxieties about backwardness are embodied through assemblages and temporalities that designate certain bodies as lagging behind in progress. Furthermore, this study contributes to the body of scholarship on the entanglements of race, religion, and identity in non-Western contexts, demonstrating how the secular and the race–religion constellation are co-constituted in everyday life. Full article

Accurate extraction of weak fault information from non-stationary vibration signals collected by vibration sensors is challenging due to severe noise and interference. While variational mode decomposition (VMD) has been effective in fault diagnosis, its reliance on predefined parameters, such as center frequencies and mode number, limits its adaptability and performance across different signal characteristics. To address these limitations, this paper proposes an improved variational mode decomposition (IVMD) method that enhances diagnostic performance by adaptively determining key parameters based on scale space representation. In concrete, the approach constructs a scale space by computing the inner product between the signal’s Fourier spectrum and a Gaussian function, and then identifies both the mode number and initial center frequencies through peak detection, ensuring more accurate and stable decomposition. Moreover, a multipoint kurtosis (MKurt) criterion is further employed to identify fault-relevant components, which are then merged to suppress redundancy and enhance diagnostic clarity. Experimental validation on locomotive bearings with inner race faults and compound faults demonstrates that IVMD outperforms conventional VMD by effectively extracting fault features obscured by noise. The results confirm the robustness and adaptability of IVMD, making it a promising tool for fault diagnosis in complex industrial environments. Full article

Background: The global space economy has grown remarkably, witnessing a 10-fold increase in active satellites during the last 15 years. This growth was accompanied by both the increase in geopolitical tensions feeding huge investments (the New Space Race), on the one hand, and the transformation, shifting from a domain historically dominated by government-led programs to one partially energized by commercial players and innovative business models (“New Space”), on the other hand. Objective: To assess the space economy’s current state and future prospects by considering its economic and social dimensions. Methods: Over 120 scholarly articles and “grey” literature positions (e.g., industry reports) were reviewed. The review was structured by a modified Structure–Conduct–Performance framework originally developed by industrial organization (IO) scholars. Findings: Outer space creates extremely harsh conditions for placing and operating objects in orbits, which results in high launching costs, steep reliability standards, capital intensity, and risks that are unmatched in most terrestrial industries. One of the main motivations to venture into this harsh domain was, and still is, the desire to dominate or the fear of being subjugated by others. This “original sin”, born of geopolitical rivalries, continues to cast a shadow over the space economy, channeling the majority of public space budgets into military-related programs. Moreover, many space technologies have a dual-use feature. Not surprisingly, governments are still the major source of demand, dominating midstream in the space value chain. This triad—harsh physics, great power rivalry, and a state-centric midstream—produces a specificity of the sector. In the recent two decades, new entrants (called “New Space”) have begun altering market structure, resulting in new conduct patterns focused on pursuits towards serial production, reusability, and lowering costs. Performance outcomes are mixed. While some efficiency gains are unprecedented, some doubts about market power and negative externalities arise. The assessment of the space economy’s performance is a challenge, as such, due to the blurred boundary between political objectives (supplying public goods, mitigating negative externalities) and economic optimization. Such trade-offs are becoming even more complicated considering the potential conflict between national and global perspectives. The paper offers a preliminary, descriptive study of the space economy through the lens of the modified S-C-P framework, laying basic foundations for the future, possibly more rigorous research of the increasingly important space economy. Full article

In Ten Little Indians, Sherman Alexie presents nine poignant and emotionally resonant stories about Native Americans’ struggle with alienation and stereotypes. Instead of focusing merely on the ethnic identity of American Indians, Alexie writes about a particular group of people sharing similar circumstances and addresses their common humanity, namely their search for love and respect in urban spaces. Alexie questions the authenticity of Indian identity and asserts that a “mental reservation” exists in the minds of Indian people which significantly influences their perceptions of self and community. Race, as a medium of seeing “the other” permeates U.S. society, especially in the wake of terrorist attacks. However, racial profiling has proven to be an ineffective means of detecting criminals and criminal activities, and has obstructed social relationships, bringing emotions of fear, loneliness and grief to urban Indians. In response to the modernity crisis, Alexie explores the American Indian cosmopolitanism in Ten Little Indians, and envisions a human social community based on reciprocity and mutual respect. His concerns regarding ordinary people’s life experiences and their ways of forming healthy relationships exhibit his considerable hope for “the triumph of the ordinary”. Full article

This paper proposes the application of Yosso’s Community Cultural Wealth (CCW) framework, rooted in the critical race theory (CRT), as a transformative lens for sport-based youth development (SBYD) research. Moving beyond traditional deficit-based models, which often depict youth as problematic or at-risk, CCW emphasizes recognizing and building upon the cultural strengths and assets of marginalized youth. We begin by reviewing the development of theoretical applications within the youth development, positive youth development (PYD), and SBYD literature to highlight the criticisms against conventional deficit-focused approaches. CCW offers an asset-oriented lens by offering six forms of capital—aspirational, linguistic, familial, social, navigational, and resistant—that are typically overlooked in mainstream frameworks. We illustrate how these forms of capital can reposition SBYD programs as spaces for cultivating resilience, identity, and social justice while addressing systemic inequities. By incorporating CCW with participatory research methods and critical theories, such as intersectionality and CRT, researchers can broaden the theoretical and methodological scope of SBYD. This paper concludes by suggesting practical implications for program design, organizational advocacy, and policy development, advocating for culturally responsive, community-led initiatives that prioritize the active engagement and empowerment of marginalized youth. In sum, CCW provides the “why” for critical SBYD research and practice. Full article

Inequitable access to parks persists in cities where race, income, and geography shape residents’ proximity to public green space. This study analyzes 20 parks in Salt Lake City—10 in the Eastside and 10 in the Westside—using demographic, housing, and transportation data drawn from GIS tools and spatial platforms. By assessing indicators such as household income, racial composition, rent burden, walkability, and transit access, the findings confirm that Westside parks—located in lower-income and more racially diverse neighborhoods—are significantly less accessible. Eastside parks, by contrast, tend to serve higher-income, majority-white areas with better infrastructure. This paper illustrates how spatial inequality in surrounding conditions limits park accessibility, and it proposes GIS as a tool for diagnosing and addressing environmental injustice in urban planning. Full article

Test Case Prioritization (TCP) is critical in software quality testing, aiming to identify high-priority test cases early in the testing process. This study proposes a novel TCP approach using the Dragon Boat Optimization Algorithm (DBOA), inspired by the synchronized teamwork seen in dragon boat racing. The proposed TCP-DBOA model strategically reorders test cases to improve fault detection efficiency while minimizing execution time. By using the Average Percentage of Faults Detected (APFD) as the optimization objective, the model enhances both coverage speed and testing effectiveness. DBOA offers advantages in handling large search spaces, balancing exploration and exploitation, and adapting to complex testing scenarios. The performance of TCP-DBOA is evaluated using four benchmark datasets—GZIP, GREP, TCAS, and CS-TCAS—demonstrating superior APFD values compared to existing methods. Results confirm the model’s robustness in reducing test execution time and improving fault detection early in the test cycle. This approach contributes to faster, more efficient regression testing, especially in continuous integration environments. Full article

In the 2017 Danzy Senna novel, New People, the mixed-race protagonist is described as a white ‘passing’ mixed-race woman who interprets the death of her adopted Black mother as a symbol of the death of her Black identity. The book’s themes parallel ongoing multiracial political debates that explore the extent to which mixed-race people with proximity to whiteness perceive individual agency in identity negotiations. This paper examines how mixed-race people in Britain discuss the experience of loss and separation, thereby demonstrating how loss and separation interact with their sense of self. Employing a content and thematic analysis of 19 stories from the British-based organisation Mixedracefaces, my findings show that the mixed-race respondents saw their racially marginalised family members as critical connections to their own. Thus, a process of identity de/construction was instigated when they experienced a loss that perpetuated and/or challenged monoracism. I argue that we must disrupt oppressive monoracial paradigms of ‘race’ that uphold monoracial whiteness and prevent mixed-race identity agency. Through mixed-race counterstories, we can reveal further generational histories of struggles, resistance, love, and refusal in Britain. I intentionally provide a safe space for the millions of mixed people looking for connection through this experience. Full article

The relationship between socioeconomic and demographic characteristics and health effects of green spaces has been studied, suggesting that certain groups may reap more health benefits from exposure to nature. However, the link between the perceived benefits of nature and socioeconomic and demographic characteristics remains a gap in the literature. We used a subsample (n = 711, 2018–2019) from an environmental cardiovascular risk cohort to investigate the perceived benefits of nature. Participants completed an 11-item survey about their perceptions of the benefits of nature at in-person visits. Socioeconomic and demographic characteristics including income, education, race, biological sex at birth, and age, were self-reported. Generalized linear models were used to evaluate associations between the perceived benefits of nature and demographic and socioeconomic factors; odds ratios and 95% confidence intervals (CIs) are reported. Both unadjusted and fully adjusted models for race, age, sex, and education are reported. Our results suggest that participants who identified as male, a member of a minoritized population, and/or completing less education perceived nature as less beneficial. Although additional research is needed to better understand contributors to these perceptions, access to convenient, safe, and multi-use green spaces may be important in encouraging time in nature and shifting perceptions of the benefits of greenness. Full article

In this duoethnography, we examine our own experiences of multiracial fatherhood to disrupt metanarratives about race, multiraciality, and privilege. By synthesizing critical multiracial theory and critical race parenting, we advance three propositions of critical multiracial parenting to attend to the permanence of (mono)racism, the shifting salience of multiraciality across time and space, and the possibilities of expansive pedagogical approaches to challenge racial rigidity. We weave together and disrupt each other’s narratives by presenting two scenes of multiracial fatherhood, complicating our understanding and assumptions of White privilege, multiracial identity, and generational proximity to an interracial union. Our hope is that our duoethnography is not a beginning nor an end; rather, we call on readers to continually add their voices to disrupt and complicate how whiteness works in family systems and multiraciality discourses. Full article

U.S. government agencies execute home relocation programs, known as buyouts, in flood-prone areas to reduce hazard exposure. By converting the buyout properties into open space, these governmental agencies assume ownership and management responsibilities. As with all landscapes, the post-buyout landscape reflects power dynamics and institutional forces that shape how the land is managed, perceived, and used. For acquired properties, historic housing polices, disaster risk reduction strategies, and the social construction of the land have all accumulated over time on the post-buyout landscape and influence contemporary land management practices. To understand the influence of power and social capital on post-buyout land management, this study analyzes land management practices and compares them with the socioeconomic characteristics of buyout neighborhoods in Harris County, Texas, USA, a county with a fifty-year buyout history. Results indicate that homeownership status, race, and ethnicity were related to post-buyout land management to varying degrees, thus reflecting differing degrees of social capital in buyout neighborhoods and therefore power to shape the management of post-buyout open space. Full article