Search Results (453)

In constrained waters, multi-USV cooperative encirclement of highly maneuverable targets is strongly affected by partial observability as well as obstacle and boundary constraints, posing substantial challenges to stable cooperative control. Existing deep reinforcement learning methods often suffer from low exploration efficiency, pronounced policy oscillations, and difficulties in maintaining the desired encirclement geometry in complex environments. To address these challenges, this paper proposes an adaptive difference-based multi-agent policy gradient method (MAADPG) under the centralized training and decentralized execution (CTDE) paradigm. MAADPG deeply integrates potential-field-inspired geometric guidance with a multi-agent deterministic policy gradient framework. Specifically, a guidance module generates geometrically interpretable candidate actions for each pursuer. Moreover, a difference-driven adaptive action adoption mechanism is introduced at the behavior policy execution level, where guided actions and policy actions are locally compared and the guided action is adopted only when it yields a significantly positive return difference. This design enables MAADPG to select higher-quality interaction actions, improve exploration efficiency, and enhance policy stability. Experimental results demonstrate that MAADPG consistently achieves fast convergence, stable coordination, and reliable encirclement formation across representative pursuit–encirclement scenarios, including obstacle-free, sparsely obstructed, and densely obstructed environments, thereby validating its applicability and stability for multi-USV encirclement tasks in constrained waters. Full article

Curling presents a challenging continuous-control problem in which shot outcomes depend on long-horizon interactions between complex physical dynamics, strategic intent, and opponent responses. Despite recent progress in applying reinforcement learning (RL) to games and sports, curling lacks a unified environment that jointly supports stable, rule-consistent simulation, structured state abstraction, and scalable agent training. To address this gap, we introduce a comprehensive learning framework for curling AI, consisting of a full-sized simulation environment, a task-aligned Markov decision process (MDP) formulation, and a two-phase training strategy designed for stable long-horizon optimization. First, we propose a novel MDP formulation that incorporates stone configuration, game context, and dynamic scoring factors, enabling an RL agent to reason simultaneously about physical feasibility and strategic desirability. Second, we present a two-phase curriculum learning procedure that significantly improves sample efficiency: Phase 1 trains the agent to master delivery mechanics by rewarding accurate placement around the tee line, while Phase 2 transitions to strategic learning with score-based rewards that encourage offensive and defensive planning. This staged training stabilizes policy learning and reduces the difficulty of direct exploration in the full curling action space. We integrate this MDP and training procedure into a unified Curling RL Framework, built upon a custom simulator designed for stability, reproducibility, and efficient RL training and a self-play mechanism tailored for strategic decision-making. Agent policies are optimized using Soft Actor–Critic (SAC), an entropy-regularized off-policy algorithm designed for continuous control. As a case study, we compare the learned agent’s shot patterns with elite match records from the men’s division of the Le Gruyère AOP European Curling Championships 2023, using 6512 extracted shot images. Experimental results demonstrate that the proposed framework learns diverse, human-like curling shots and outperforms ablated variants across both learning curves and head-to-head evaluations. Beyond curling, our framework provides a principled template for developing RL agents in physics-driven, strategy-intensive sports environments. Full article

The Rasch model has the desirable property that item parameter estimation can be separated from person parameter estimation. This implies that no assumptions about the ability distribution are required when estimating item difficulties. Pairwise estimation approaches in the Rasch model exploit this principle by estimating item difficulties solely from sample proportions of respondents who answer item i correctly and item j incorrectly. A recent contribution by Tutz introduced Tutz’s pairwise separation estimator (TPSE) for the more general class of homogeneous monotone (HM) models, extending the idea of pairwise estimation to this broader setting. The present article examines the asymptotic behavior of the TPSE within the Rasch model as a special case of the HM framework. It should be emphasized that both analytical derivations and a numerical illustration show that the TPSE yields asymptotically biased item parameter estimates, rendering the estimator inconsistent, even for a large number of items. Consequently, the TPSE cannot be recommended for empirical applications. Full article

Background: Sexual dysfunction (SD) affects up to two-thirds of individuals with early-onset Parkinson’s disease (PD), yet it remains underexplored in developing countries where stigma, depression, and treatment side effects may worsen its burden. This study investigated the magnitude and correlation of SD in early-onset PD. Methods: A cross-sectional study included 74 individuals with PD onset at ≤55 years of age. SD was assessed using the Medical Outcomes Study Sexual Functioning Scale, alongside interviews on sexual experiences after initiating PD medication. Prevalence was estimated descriptively, and Spearman’s correlation identified correlates of SD. Results: Half of participants reported SD, including lack of sexual interest (52.7%), difficulty relaxing or enjoying sex (52.7%), and impaired arousal (50%). Among men, 48% experienced erectile problems, while 44% of women reported difficulty achieving orgasm. After starting anti-Parkinson’s medication, 16% noted markedly reduced sexual desire, whereas nearly 10% reported increased desire. In men, SD correlated with levodopa dose (r = 0.411, p < 0.01). In women, SD correlated with stigma (r = 0.389, p < 0.05), depression (r = 0.529, p < 0.01), and anxiety (r = 0.629, p < 0.01). Conclusions: One in two individuals with early-onset PD experiences SD, independent of gender. Findings highlight the need for routine sexual health assessment and careful monitoring of treatment side effects. Interventions targeting stigma, depression, and anxiety are critical to improve sexual well-being in this population. Full article

Virtual reality (VR) provides immersive, interactive environments that can be carefully controlled for shaping movement during rehabilitation. Game mechanics such as object velocity and trajectory are often manipulated to increase engagement, but their effects on motor control strategies relevant for therapy remain unclear. This study examined how ball velocity and parabolic vertex height influence interception performance and movement patterns in VR dodgeball. Twenty-one healthy adults (10 males and 11 females; mean age of 24 ± 8 years) played virtual dodgeball in two visual environments. In the first visual environment, ‘Cannon’ dodgeball, the vertex heights were 4 m and 8 m. In the second visual condition, ‘Day’ dodgeball, the velocities were set to 40 m/s and 60 m/s. The outcomes included interception success, time to intercept, and joint kinematics (ankle, knee, hip, and lumbar spine flexion angles). Both higher velocity and vertex height reduced interception success (p < 0.001* and p < 0.001* respectively), indicating increased difficulty. However, only vertex height significantly influenced joint flexion patterns during gameplay (ankle p < 0.001*, knee p < 0.001*, hip p = 0.019*, and lumbar p = 0.026*). These results suggest that while both vertex height and velocity modulates task challenge, trajectory and vertex height more effectively shape movement strategies. Tailoring the vertex height of launched virtual objects in VR games may therefore optimize therapeutic engagement and promote desired motor behaviors. Full article

The aim of the study is to analyze the challenges and opportunities of conversions and adaptations of Polish modernist hotel buildings to new functions. Preliminary research shows that hotels constitute a significant group among unused buildings from that period. This issue remains unexplored, while the market situation shows that investors will increasingly face an economic, social, and environmental dilemma as to demolish existing facilities and replace them with new structures or thoroughly rebuild and reuse. The study was conducted based on an analysis of groups of criteria in terms of the potential and difficulties associated with investments utilizing the existing hotel fabric, taking into account environmental, formal, structural, functional, and socio-cultural aspects. The results of the study show that the conversion or adaptation of modernist hotels in Poland to a new function is primarily determined by technical issues, i.e., the original structural layout and technical condition of the building, and such investments require decisive action, primarily in terms of replacing external partitions and adapting internal communication systems. However, it has been proven that, in many cases, such investments are possible, and they bring a number of environmental and social benefits, so they are at least desirable from the perspective of sustainable development. Full article

Background: We investigated the role of pharmacists in adverse event (AE) management during renal cell carcinoma (RCC) drug therapy by surveying patients, physicians, and pharmacists. We identified the types of AEs for which pharmacist involvement is beneficial and explored measures to promote pharmacist intervention. Methods: This was an ad hoc analysis of a questionnaire-based cross-sectional web survey conducted from May to June 2022 among patients undergoing RCC drug therapy, physicians prescribing RCC treatments, and pharmacists involved in oncology care in Japan. Results: A total of 83 patients with metastatic RCC, 165 physicians, and 218 pharmacists were included. Among patients, 28.9% reported experiencing AEs or symptoms requiring pharmacist intervention. Most physicians (78.2%) and pharmacists (96.3%) supported pharmacist involvement in AE management. Notably, 35.6% of patients who reported no AEs or symptoms requiring pharmacist intervention acknowledged difficulty in communicating AEs to their physicians. Regarding desired pharmacist interventions for AEs, patients prioritized rash/pruritus, fatigue, and diarrhea; physicians emphasized stomatitis and anorexia; pharmacists identified constipation, stomatitis, and diarrhea. The most common reason patients valued pharmacist involvement was the reassurance of support from multiple healthcare providers. Physicians and pharmacists valued pharmacists’ greater familiarity with AE management, particularly considering physicians’ limited time. Raising awareness among patients and healthcare professionals, patient requests, and improving institutional support were strategies to enhance pharmacist involvement. Over 86% of healthcare professionals considered pharmaceutical outpatient clinics necessary to strengthen interdisciplinary collaboration. Conclusions: This study highlights widespread support among patients, physicians, and pharmacists for pharmacist involvement in managing AEs during RCC drug therapy. Full article

Evaluating students’ knowledge and competencies to achieve the desired learning goals is one of the most important stages of the teaching process. The purpose of this study is to create a dataset consisting of programming questions and determine the level of these questions according to the Bloom taxonomy and the weight of each concept they contain, by taking expert opinion. The student’s score, question difficulty, and complexity levels are considered to determine the extent to which the student has learned a concept. A total of 96 students participated in this study, 51 in the experimental group and 45 in the control group. Random design for a pre-test–post-test control group was used to measure the students’ learning performance and self-efficacy regarding programming. While the experimental group students were given detailed feedback on how much they learned a concept, the control group students were only informed about the total score they received from the exam. The learning performance and self-efficacy perception regarding programming were analyzed using the paired samples t-test. Results show that the learning performance and self-efficacy perception regarding programming of the experimental group students improved significantly compared to the control group. Full article

Affordable housing has evolved to meet the difficulties of increased demand by offering acceptable living spaces for middle- to low-income families and facilitating access to housing units based on their annual income. This research seeks to investigate the relationship between housing spacing standards and family desire for affordable multifamily housing. It sought to address the changes that were occurring in the internal spaces of multi-story housing because of the inhabitants’ evolving needs. The study investigates the habitability of 25 residential apartments within 6 affordable multifamily housing compounds established in Sulaymaniyah city in Iraq in accordance with Iraqi housing standards. The results show that the rise in family size was the key reason for the considerable physical changes and enhancements that families made to their units. Crucially, the study found an explicit relationship: the wider the difference between the actual habitable space and the minimum Iraqi standards, the more frequently modifications occurred. This implies that inflexible space standards fail to fulfill the actual needs of low-income families, forcing occupants to make alterations despite the possible deterioration of the unit’s internal environment. The study contributes to the discourse on affordable housing in Iraq by offering empirical evidence of household-driven change and underscoring the necessity of incorporating adaptability into future affordable housing design policies. Full article

This study examines students’ experiences with Biomes, a Collaborative Immersive Virtual Environment (CIVE) designed to teach climate zones through virtual reality. The research employed a combination of Research through Design (RtD) methodology and Interpretative Phenomenological Analysis (IPA) to explore how students view their CIVE experience and its perceived impact on learning. 16 students (aged 12–15) participated in structured lessons using Meta Quest 2 headsets, followed by semi-structured focus groups. The analysis yielded three overarching themes: challenges with object manipulation, perceived benefits, and desired additional functionalities. While participants encountered challenges with precise thumbnail placement and grip distance control, they reported high levels of enjoyment, appropriate difficulty levels, and notable knowledge acquisition. The immersive nature of the virtual environment created authentic experiences that traditional classrooms cannot replicate, although perceptions varied by age group, with younger students showing greater enthusiasm. The findings demonstrate that despite technical challenges, CIVEs have the potential to facilitate engaging educational experiences. It is imperative to integrate advanced interaction techniques, incorporate age-specific design elements, and strike a balance between technological innovation and pedagogical efficacy to optimise educational outcomes in virtual reality learning environments, thereby enhancing the effectiveness of future developments in this domain. Full article

Background: The treatment of bacterial dermatological diseases is currently facing major difficulties, determined by the alarming increase in the resistance of pathogenic bacteria to conventional therapies. In this context, a viable and effective alternative is represented by the use of phytocompounds to obtain the desired therapeutic effect. The essential oil of Origanum vulgare L. stands out for its antibacterial, anti-aging, collagen synthesis stimulating and wound healing properties. However, its use is limited by certain disadvantages, such as poor stability and the risk of skin irritation due to accumulation in the dermis. Method: The process of formulating the emulgel with oregano oil respected the specific technological steps. The resulting emulgel was subjected to a series of tests, including organoleptic, stability and antimicrobial efficacy determinations. In addition, an in vivo study was conducted to confirm the lack of irritation, involving six groups of patients differentiated by age, sex and skin phenotype. Results: The test results revealed that the emulgel formulated with oregano oil is stable, has organoleptic properties and an appropriate pH for topical use. The product demonstrated antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa. In addition, short-term in vivo tests (20 min—96 h) confirmed the safety and absence of skin irritation, indicating its potential as an effective alternative treatment. Conclusions: In conclusion, the emulgel with origanum oil represents an innovative formulation for topical application. The product is well tolerated by the skin and does not cause irritation, and its antibacterial properties validate it as a promising therapeutic solution. Full article

The high strength and light weight of aluminum matrix composites have made them the material of choice for many engineering applications. Snail shells and other bio-reinforcements offer a potential substitute for conventional ceramic reinforcements. However, the inherent difficulty in machining Aluminum Matrix Composites (AMCs) stems from the presence of reinforcing particles. This study investigates the machinability of aluminum matrix composites (AMCs) reinforced with Physella Acuta snail shell (PAS) particles using Wire Electrical Discharge Machining (WEDM) with a zinc-coated brass wire electrode. The primary objective is to determine how various input elements affect process conditions to achieve the desired surface quality. In order to do this, the Random Decision Forest approach was employed. Scanning Electron Microscopy (SEM) evaluation revealed the presence of microvoids, surface defects, deep craters, and crack propagation. It was found that the random forest method had an F1-score of 0.94, a recall of 0.96, and a precision of 0.97. The optimized parameters yielded an MRR of 0.5 mm³/min, SR of 2.14 µm, and EWR of 0.017. Full article

Background: Multiple sclerosis (MS) leads to early retirement in one-third of patients. The aim of this study is to analyze the difficulties at work and to collect suggestions for support measures at the workplace to maintain the ability to work for people with MS. Methods: Qualitative interviews were conducted with 20 people affected by MS. The participants’ experiences with workplace support were summarized and suggestions for workplace measures were presented. Results: Lack of offers of health-related measures and missing adjustments of the workplace has been analyzed. Offering flexible working hours and measures against fatigue is desired. Intensifying the cooperation between labor market service, health care providers and companies can help reintegrate affected people. Conclusions: Workplace education about MS and health-related measures is needed. Technical adaptations and flexible working hours can support in maintaining workability. Measures against fatigue must be developed and companies must set further measures to support people with illnesses. Full article

Due to their interesting physicochemical and bioactive properties, regenerated fibres (including cellulose and collagen regenerated fibres) have been considered attractive biomaterials for biomedical applications. These regenerated fibres have an altered molecular arrangement compared to the native fibres and exhibit unique properties. Despite their distinctive structural characteristics, a meagre amount of research explores their potential for the development of tissue-engineering bio-composites. This work focuses on exploring the promise of cellulose and collagen-based regenerated fibres in tissue-regeneration bio-composite development. Initially, the work investigates the similarities and dissimilarities between the collagen and cellulose structures, which are linked to their specific properties, such as crystallinity, chemical characteristics, and mechanical properties. It then delves deeper into their molecular structural reassembly and various aspects of the already reported bio-composites developed using them. Finally, their promise in the development of tissue-engineering bio-composites is explored through a meticulous comparative analysis of their advantages and challenges. It was found that efficient biodegradability is one of the key advantages of regenerated fibres, whereas difficulty in processing presents a significant disadvantage. Despite these facts, regenerated fibres can incorporate enhanced and desired properties into the bio-composite matrix, which could lead to tissue-specific bio-regenerative applications. Full article

The current study examined the attitudes of elementary and middle school principals and school counselors toward including students with special needs in regular classrooms. 243 participants completed questionnaires on their self-efficacy, job satisfaction, stress, and attitudes toward inclusion. Additionally, 22 semi-structured interviews were conducted to gain a deeper understanding of how principals and counselors deal with the inclusion of students with special needs in their school. The study’s findings reveal a difference between middle school counselors and principals and those in elementary schools in terms of the desire for inclusion. It was also found that the less the counselors believe in themselves, the less they are in favor of inclusion, while the more satisfied they are with their work, the more they support inclusion. Qualitative analysis brought up various difficulties in the inclusion process. Full article