Search Results (42)

Five-axis sweep scanning measurement technology, as a novel contact measurement technology, offers excellent reachability and high measurement efficiency for complex parts. However, deviations between the measurement instructions based on the model and the workpiece exist, leading to mismatches between the intended and actual sweep scanning areas, which manifest as displacements of the scanning boundaries and subsequently impact the acquisition of sampling points. When these sampling points are utilized to evaluate the machining quality of workpieces, the accuracy and reliability of the assessment results are compromised. Therefore, by focusing on the phenomenon of boundary displacement in a five-axis sweep scanning measurement, the sampling principle has been analyzed, the constrained sector for the probe tip trajectory in a five-axis scanning measurement has been defined, and the concept of the trajectory constrained sector effect has been proposed for the first time. The constrained sector effect reveals how deviations affect the scanning boundary positions and acquisition of sampling points. Based on the constrained sector effect, the influence of deviations on boundary displacement and sampling point acquisition in single-patch and multiple-patch measurement scenarios is discussed. Furthermore, practical engineering recommendations are provided, aiming to reduce the impact of deviations on the completeness of sampling point acquisition. Full article

Model checking has become a widely used and precise technique for verifying software systems. However, a major challenge in model checking is state space explosion, which occurs due to the exponential memory usage required by the model checker. To address this issue, meta-heuristic and evolutionary algorithms offer a promising solution by searching for a state where a property is either satisfied or violated. Recently, various evolutionary algorithms, such as Genetic Algorithms and Particle Swarm Optimization, have been applied to detect deadlock states. While these approaches have been useful, they primarily focus on deadlock detection. This paper proposes a fuzzy algorithm to analyse reachability properties in systems specified through Graph Transformation Systems with large state spaces. To achieve this, the existing Particle Swarm Optimisation algorithm, which is typically used for deadlock detection, has been extended to analyse reachability properties. To further enhance accuracy, a Fuzzy Adaptive Particle Swarm Optimization algorithm is introduced to determine which states and paths should be explored at each step-in order to find the corresponding reachable state. Additionally, the proposed hybrid algorithm was applied to models generated through rule composition to assess the impact of rule composition on execution time and the number of explored states. These approaches were implemented within an open-source toolset called GROOVE, which is used for designing and model checking Graph Transformation Systems. Experimental results demonstrate that proposed hybrid algorithm reduced verification time by up to 49.86% compared to Particle Swarm Optimization and 65.17% compared to Genetic Algorithms in reachability analysis of complex models. Furthermore, it explored 32.7% fewer states on average than the hybrid method based on Particle Swarm Optimization and Gravitational Search Algorithms, and 57.4% fewer states compared to Genetic Algorithms, indicating improved search efficiency. The application of rule composition further reduced execution time by 35.7% and the number of explored states by 41.2% in large-scale models. These results confirm that proposed hybrid algorithm significantly enhances reachability analysis in the systems modelled via Graph Transformation, improving both computational efficiency and scalability. Full article

Background/Objectives: Peripheral pulmonary lesions (PPLs) are the current challenge in bronchoscopy. Novel endoscopic approaches allow us to reach PPLs better than a few years ago. In patients with resectable non-small cell lung cancer (NSCLC), perioperative chemotherapy is associated with significantly greater event-free survival; this means that histological assessment before the resectable surgery of PPLs is becoming mandatory. Our objective was to evaluate the diagnostic yield (DY) of a thin bronchoscope (TB) for PPLs suspected for lung cancer that are not reachable with conventional bronchoscopy. Methods: A total of 176 patients with PPLs were evaluated from January 2022 to July 2023. Of the patients, 26 presented with not reachable PPLs with conventional bronchoscopy, and underwent the procedure again with a TB. When possible, R-EBUS was used. PPLs’ dimensions were recorded via chest computed tomography (CT) scan. DY was evaluated. Results: Mean lesion size was 29 mm, and overall DY for TB was 65% (17/26). When the lesion was bigger than 20 mm, DY was 76.5% (13/17), whereas in lesions smaller than 20 mm, DY was 55% (5/9). When PPLs presented a bronchus sign in the CT scan, diagnostic performance of TB was significantly better (76.5% vs. 40%, p = 0.04) compared to PPLs without a bronchus sign, independent from PPL dimensions. R-EBUS did not change DY. Conclusions: TB easily allows us to reach and sample PPLs with a high DY if a bronchus sign is positive, independently from PPL dimensions. Further studies are needed to evaluate if more flexible and penetrating bronchial wall biopsy tools can augment DY for PPLs with TB. Full article

This paper proposes an enhanced local path planning method based on the Dynamic Window Approach (DWA), enabling a mobile robot to safely avoid obstacles and efficiently reach its destination. To overcome the limitations of the conventional DWA in handling dynamic obstacles and to improve goal reachability, the velocity term—originally evaluated solely by speed—was redefined as the distance difference between the robot’s predicted future position and the target destination. This modification allows the robot to more effectively anticipate its short-term position while simultaneously considering potential obstacle locations. In particular, a linear prediction model for dynamic obstacle behavior was introduced, which estimates the future positions of obstacles based on their current position, velocity, and heading direction. Under the assumption that obstacles maintain constant speed and direction over short intervals, this model enables the robot to proactively plan avoidance maneuvers before a collision risk arises. Furthermore, a novel risk assessment strategy was incorporated to enhance collision prevention. This approach categorizes obstacles in front of the robot according to both distance and angle, evaluates obstacle density in various directions, and guides the robot toward safer paths with fewer surrounding obstacles. The effectiveness of the proposed method was validated through extensive simulations, comparing the conventional DWA, a modified DWA with the new velocity term, and the proposed DWA with dynamic obstacle behavior prediction. The results demonstrated that the proposed approach significantly reduced the number of collisions and overall travel time, thereby confirming its superiority in highly dynamic and uncertain environments. Full article

Awkward postures are a significant contributor to work-related musculoskeletal disorders (WRMSDs), which represent great social and economic burdens. Various posture assessment tools assess WRMSD risk but fall short in providing an elucidating risk breakdown to expedite the typical time-consuming ergonomic assessments. Quantifying, automating, but also complementing posture risk assessment become crucial. Thus, we developed a framework for a holistic posture assessment, able to, through inertial data, quantify the ergonomic risk and also qualitatively identify the posture leading to it, using Deep Learning. This innovatively enabled the generation of a report in a graphical user interface (GUI), where the ergonomic score is intuitively associated with the postures adopted, empowering workers to learn which are the riskiest postures, and helping ergonomists and managers to redesign critical work tasks. The continuous posture assessment also considered the previous postures’ impact on joint stress through a kinematic wear model. As use case, thirteen subjects replicated harvesting and bricklaying, work tasks of the two activity sectors most affected by WRMSDs, agriculture and construction, and a posture assessment was conducted. Three ergonomists evaluated this report, considering it very useful in improving ergonomic assessments’ effectiveness, expeditiousness, and ease of use, with the information easily understandable and reachable. Full article

To effectively mitigate service slope disaster risks in mountainous areas and enhance the overall safety of highway operations, based on the geological and structural characteristics of slopes, considering slope technical conditions, overall stability, and potential disaster consequences, 25 important influencing factors are systematically identified. The identification process integrates insights from the relevant literature, expert opinions, and historical disaster maintenance records of such slopes. An integrated approach combining Interpretive Structural Modeling (ISM) and Bayesian Networks (BNs) is utilized to conduct a quantitative analysis of the interrelationships and impact strength of factors influencing the disaster risk of mountainous service highway slopes. The aim is to reveal the causal mechanism of slope disaster risk and provide a scientific basis for risk assessment and prevention strategies. Firstly, the relationship matrix is constructed based on the relevant prior knowledge. Then, the reachability matrix is computed and partitioned into different levels to form a directed graph from which the Bayesian network structure is constructed. Subsequently, the expert’s subjective judgment is further transformed into a set of prior and conditional probabilities embedded in the BN to perform causal inference to predict the probability of risk occurrence. Real-time diagnosis of disaster risk triggers operating slopes using backward reasoning, sensitivity analysis, and strength of influence analysis capabilities. As an example, the earth excavation slope in the mountainous area of Anhui Province is analyzed using the established model. The results showed that the constructed slope failure risk model for mountainous operating highways has good applicability, and the possibility of medium slope failure risk is high with a probability of 34%, where engineering geological conditions, micro-topographic landforms, and the lowest monthly average temperature are the main influencing factors of slope hazard risk for them. The study not only helps deepen the understanding of the evolutionary mechanisms of slope disaster risk but also provides theoretical support and practical guidance for the safe operation and disaster prevention of mountainous highways. The model offers clear risk information, serving as a scientific basis for managing service slope disaster risks. Consequently, it effectively reduces the likelihood of slope disasters and enhances the safety of highway operation. Full article

The encapsulation of particular quality functions and predicates within temporal logic formulas markedly enhances the representation of detailed temporal characteristics within a system. During our preliminary investigations, we innovatively combined quality constraint functions and predicates with Possibility Linear Temporal Logic (PoLTL), yielding the conception of Fuzzy Linear Temporal Logic with Quality Constraints (QFLTL). This amalgamation results in a significant elevation of QFLTL’s expressivity relative to PoLTL, ensuring the preservation of informational integrity whilst achieving a synchronized, yet selectively inclined, and exact consolidation of path reachability specifics alongside property satisfaction evaluations. This treatise represents a significant contribution to the field by integrating quality constraint functions and predicates into Possibility Computation Tree Temporal Logic (PoCTL), thus giving rise to Fuzzy Computation Tree Temporal Logic with Quality Constraints (QFCTL). We provide a comprehensive definition of QFCTL’s syntax, conduct an in-depth analysis of its logical characteristics, outline a precise model checking algorithm for QFCTL, and perform a meticulous complexity assessment of said algorithm. It is illustrated by examples that PoCTL is a proper subset of QFCTL, and QFCTL has stronger expressive power than PoCTL and can characterize more refined temporal properties of the system. An in-depth exploration of the logical characteristics of QFCTL was carried out, showing its unique logical characteristics that are distinct from other temporal logic systems under the influence of quality constraints. In particular, the introduction of characteristic predicates effectively classifies the satisfaction of temporal formulas, making the logical framework of QFCTL more complete compared to the existing probabilistic temporal logic. Moreover, by enriching QFCTL with a quantitative characteristic predicate operator, we innovate, culminating in the development of an enhanced Fuzzy Computation Tree Temporal Logic with Quality Constraints (QFCTL*). The logical characteristics of QFCTL* are explored in detail. It is shown that with the support of quantitative feature predicates, QFCTL* can divide the satisfaction of temporal formulas more delicately than QFCTL. The decision theorems for the semantics of QFCTL* formulas containing quantitative feature predicates are given, and the decidability of QFCTL* is strictly proved. Through the bounded-depth search of GPKS, a model-checking algorithm of QFCTL* on GPKS is presented. The correctness of the algorithm is proved, and the complexity of the algorithm is analyzed. In order to prove the practical applications and strong expressive capabilities of QFCTL and QFCTL*, we present a model-checking example as empirical evidence for the effectiveness of the proposed model-checking algorithms. Through this example, we verify that, compared with the existing PoCTL, QFCTL and QFCTL* can avoid the loss of system path reachability information or system property satisfaction information, ensure the synchronization of the two types of information, and fuse these two types of information according to weight preferences. QFCTL and QFCTL* can also synthesize temporal formulas that characterize the subproperties of the system according to weight preferences. These application examples also verify that the QFCTL and QFCTL* model-checking algorithms proposed in this article are automatic and effective. Full article

Mobile ad hoc networks (MANETs) are autonomous systems composed of multiple mobile nodes that communicate wirelessly without relying on any pre-established infrastructure. These networks operate in highly dynamic environments, which can compromise their ability to guarantee consistent link lifetimes, security, reliability, and overall stability. Factors such as mobility, energy availability, and security critically influence network performance. Consequently, the selection of paths and relay nodes that ensure stability, security, and extended network lifetimes is fundamental in designing routing protocols for MANETs. This selection is pivotal in maintaining robust network operations and optimizing communication efficiency. This paper introduces a sophisticated algorithm for selecting multipoint relays (MPRs) in MANETs, addressing the challenges posed by node mobility, energy constraints, and security vulnerabilities. By employing a multicriteria-weighted technique that assesses the mobility, energy levels, and trustworthiness of mobile nodes, the proposed approach enhances network stability, reachability, and longevity. The enhanced algorithm is integrated into the Optimized Link State Routing Protocol (OLSR) and validated through NS3 simulations, using the Random Waypoint and ManhattanGrid mobility models. The results indicate superior performance of the enhanced algorithm over traditional OLSR, particularly in terms of packet delivery, delay reduction, and throughput in dynamic network conditions. This study not only advances the design of routing protocols for MANETs but also significantly contributes to the development of robust communication frameworks within the realm of smart mobile communications. Full article

Optimal upper extremity motor control and range of motion are necessary to achieve even the basic activities of daily living (ADL) function. Stroke, with resulting hemiparesis, can significantly and negatively impact an individual’s ADL function. Functional Independence Measure (FIM) self-care score can provide an assessment of what aspects and to what degree ADL functions are impaired. FIM self-care assessment can also track changes in ADL function during stroke recovery and rehabilitation. Recently, the sensor-acquired 3D motion analysis of stroke patients’ upper extremity has shown promise as a potential alternative to assess ADL function. This observational study evaluates whether the sensor-acquired upper extremity reachable workspace (RWS) measure correlates with clinician-evaluated FIM self-care score in stroke patients. Seventeen patients with stroke were enrolled in the study. FIM self-care, NeuroQoL upper extremity, and reachable workspace outcome measures (relative surface area, RSA) were collected upon rehabilitation hospital admission, at discharge, and at the 3-month visit. Pearson and Spearman’s rank correlation coefficients as well as multiple linear regression analyses were used to determine the relationships between FIM self-care, NeuroQoL, and reachable workspace RSAs. Moderately strong correlation between total reachable workspace RSA and total FIM self-care score at discharge and at 3 months were noted (r = 0.619, r = 0.661, p < 0.05), and similarly strong correlation was also noted with the upper extremity NeuroQoL total score (r = 0.690, r = 0.815, p < 0.05). Multiple linear regression analyses revealed a change in average bilateral total RSA of 0.1 unit from admission to the 3-month follow-up correlated with a respective change in the FIM self-care score of 2.011 points (95%CI: 0.663–3.360). Longitudinal improvement in ADL function during stroke rehabilitation and recovery process is correlated with improvement in reachable workspace. Full article

Emergency service facilities play a pivotal role in mitigating the impact of fire disasters in urban areas. This research article delves into the critical aspects of analyzing service coverage for emergency facilities in relation to fire disaster risk in Chiang Rai city—a strategic hub in northern Thailand. Focusing on fire disaster risk merchandise and shops, categorized by the type of hazardous materials they store and sell, this study leverages facility location data obtained through web scraping from Google Maps. Utilizing spatial analysis and Geographic Information Systems (GISs), this research evaluates the reachability of emergency services, assessing travel times and coverage efficiency. The findings reveal significant disparities, particularly within the critical 3 min response window, highlighting the need for strategic improvements. This study offers actionable insights for urban planners and policymakers, advancing the integration of spatial technology in urban disaster management to enhance public safety and resilience. Full article

Ensuring safety and efficiency in the rapidly advancing autonomous vehicle (AV) industry presents a significant engineering challenge. Comprehensive performance evaluations and critical scenario testing are essential for identifying situations that AVs cannot handle. Thus, generating critical scenarios is a key problem in AV testing system design. This paper proposes a game-theoretic adversarial interaction method to efficiently generate critical scenarios that challenge AV systems. Initial motion prediction for adversarial and surrounding vehicles is based on kinematic models and road constraints, establishing interaction action spaces to determine possible driving domains. A novel evaluation approach combines reachability sets with adversarial intensity to assess collision risks and adversarial strength for any state, used to solve behavior values for each interaction action state. Further, equilibrium action strategies for the vehicles are derived using Stackelberg game theory, yielding optimal actions considering adversarial interactions in the current traffic environment. Simulation results show that the adversarial scenarios generated by this method significantly increase incident rates by 158% to 1313% compared to natural driving scenarios, while ride comfort and driving efficiency decrease, and risk significantly increases. These findings provide critical insights for model improvement and demonstrate the proposed method’s suitability for assessing AV performance in dynamic traffic environments. Full article

Football players’ decision-making behaviours near the scoring target (finishing situations) emerge from the evolving spatiotemporal information directly perceived in the game’s landscape. In finishing situations, the ball carrier’s decision-making about shooting or passing is not an individual decision-making process, but a collective decision that is guided by players’ perceptions of match affordances. To sustain this idea, we collected spatiotemporal information and built a model to quantify the “Finishing Space Value” (FSV) that results from players’ perceived affordances about two main questions: (a) is the opponent’s target successfully reachable from a given pitch location?; and (b) from each given pitch location, the opposition context will allow enough space to shoot (low adversaries’ interference)? The FSV was calculated with positional data from high-performance football matches, combining information extracted from Voronoi diagrams (VD) with distances and angles to the goal line. FSV was tested using as a reference the opinion of a “panel of expert” (PE), composed by football coaches, about a questionnaire presenting 50 finishing situations. Results showed a strong association between the subjective perception scale used by the PE to assess how probable a shot made by the ball carrier could result in a goal and FSV calculated for that same situation ($R^2=0.6706$). Moreover, we demonstrate the accuracy of the FSV quantification model in predicting coaches’ opinions about what should be the “best option” to finish the play. Overall, results indicated that the FSV is a promising model to capture the affordances of the shooting circumstances for the ball carrier’s decision-making in high-performance football. FSV might be useful for more precise match analysis and informing coaches in the design of representative practice tasks. Full article

The construction of ecological security patterns has become a crucial approach to assessing ecosystem health and integrity and is essential for achieving sustainable and high-quality development in both urban and rural areas. Using Lanzhou City as an example, our study employed the InVEST model, ecological service importance evaluation, and hotspot analysis to classify ecological sources. Additionally, ecological corridors were identified and optimized using the least resistance model and circuit theory. The identified corridor pattern was further analyzed using space syntax and neural networks to determine the influences of various factors. This framework can be applied to the circular construction of corridors. Our findings revealed a three-stage differentiation trend in the importance of ecosystem services. Ecological source areas and corridors were densely distributed in the northwest of Lanzhou. The optimized ecological source area increased from 2914.1 km² to 4542.5 km², raising its proportion in the study area from 22.2% to 34.7%. The total number of corridors after optimization was 217, spanning a 2657.3 km length. The Gaolan Mountain area had the highest current density, whereas the ecological barrier area was mainly distributed in the northwest of Yongdeng County and the north of Yuzhong County. The spatial syntax index indicated significant potential reachability between the Honggu area and the northwest area. Finally, using neural network perceptrons to simulate ecosystem service functions, our findings revealed that habitat quality showed the best fit under single-dependent-variable prediction, followed by water yield, with soil conservation showing a poor fit. Under three-dependent-variable prediction conditions, population factors had the greatest impact on ecosystem services, while slope had the least impact. Therefore, it is important to promote the construction of green infrastructure in the northwest and southeast, improve the connectivity of ecological corridors in Honggu District, and adopt corresponding spatial corridor optimization strategies according to different ecological needs. Collectively, our findings provide a theoretical and practical basis for the construction and optimization of urban and rural ecological security patterns in the semi-arid region of Lanzhou. Full article

The transorbital approach (TOA) is gaining popularity in skull base surgery scenarios. This approach represents a valuable surgical corridor to access various compartments and safely address several intracranial pathologies, both intradurally and extradurally, including tumors of the olfactory groove in the anterior cranial fossa (ACF), cavernous sinus in the middle cranial fossa (MCF), and the cerebellopontine angle in the posterior cranial fossa (PCF). The TOA exists in many variants, both from the point of view of invasiveness and from that of the entry point to the orbit, corresponding to the four orbital quadrants: the superior eyelid crease (SLC), the precaruncular (PC), the lateral retrocanthal (LRC), and the preseptal lower eyelid (PS). Moreover, multiportal variants, consisting of the combination of the transorbital approach with others, exist and are relevant to reach peculiar surgical territories. The significance of the TOA in neurosurgery, coupled with the dearth of thorough studies assessing its various applications and adaptations, underscores the necessity for this research. This extensive review delineates the multitude of target lesions reachable through the transorbital route, categorizing them based on surgical complexity. Furthermore, it provides an overview of the different transorbital variations, both standalone and in conjunction with other techniques. By offering a comprehensive understanding, this study aims to enhance awareness and knowledge regarding the current utility of the transorbital approach in neurosurgery. Additionally, it aims to steer future investigations toward deeper exploration, refinement, and exploration of additional perspectives concerning this surgical method. Full article

Assuring home care (HC) workers’ safety is challenging because the work environment is a private home. This paper presents the process evaluation for a proof-of-concept safety intervention study to assess whether nurse-led safety coaching, using motivational interviewing and a safety handbook, could enable HC clients to improve safety in their homes. The process evaluation objectives were to (i) document the intervention’s implementation progress and (ii) assess the intervention’s dose delivery, dose reception, and fidelity. Five agencies employing liaisons (n = 5) and nurse managers (NMs, n = 8) implemented this study’s intervention and control arms. NMs assigned to the intervention arm (n = 6) coached 34 clients. Process evaluation metrics were assessed with mixed-methods data from (i) surveys completed by NMs during the intervention, (ii) postintervention audio-recorded and transcribed interviews (n = 6) with NMs and liaisons, and (iii) study progress tracking tools. The delivered dose efficiency was 85%, measured by the distribution of safety handbook copies to clients. About 94% of clients (n = 32) were considered “engaged” or “maybe engaged” during the safety coaching. Most coached clients (n = 30) were reachable for follow-up by NMs to assess intervention progress. Despite challenges, the intervention was implemented with good fidelity. Safety coaching can be applied in many HC contexts in larger populations. Full article