Search Results (1,070)

To address the diverse requirements of accuracy and robustness in integrated navigation for unmanned aerial vehicles, an interactive robust filter algorithm that integrates the interactive multiple model concept and leverages the complementary applicability of the strong tracking filter and the smooth variable structure filter is proposed. The algorithm operates as follows: the strong tracking filter, along with the smooth variable structure filter, operates side by side with distinct models. During the filter process, the likelihood function is utilized to update the filter probabilities and determine the weights for each one of the filters. Input interaction, coupled with output fusion, is then carried out. The results of the experiments validate that the presented interactive filter algorithm significantly reduces estimation errors. When confronted with complex, dynamic noise environments and system uncertainties, it retains high-precision state estimation while demonstrating markedly improved robustness. The proposed interactive robust filter algorithm is compared against the strong tracking filter, smooth variable structure filter, and strong tracking smooth filter. Taking the strong tracking smooth filter, which has the highest accuracy among the three, as the reference baseline, the presented interactive robust filter algorithm achieves over 16% improvement in velocity accuracy and over 40% improvement in position accuracy. Full article

Contemporary theories of luck face problems when it comes to moral luck, that is, luck that nevertheless partially determines moral responsibility. Either they conceive of luck as chancy or modally fragile, which is too narrow and excludes cases such as choosing to do something that is unlikely for you to do or that you do not do in many nearby possible worlds. Others see luck as primarily a matter of lack of control, which is too broad and includes things like the sun’s rising, which is outside of our control, but certainly not a matter of luck. Some try to rescue the moral luck phenomenon by positing hybrid accounts or denying that moral luck is a species of luck. Very little has been written about how Aristotle’s conceptions of luck fit into modern conceptions. Yet, Aristotle has sophisticated accounts of luck and good fortune that shed light on certain problems. I will show how Aristotle fares compared to contemporary theories and what we can learn from his approach to luck and fortune when it comes to how lack of control, modal robustness, and probability factor into luck, the difference between luck and good fortune, and whether moral luck is a species of luck. Full article

Endometriosis is a chronic gynecological pathology marked by the aberrant proliferation of tissue analogous to the endometrial lining outside the uterine cavity. This disorder frequently engenders persistent pelvic discomfort, infertility, and an extensive array of additional manifestations, including menorrhagia, dyspareunia, and gastrointestinal anomalies. Affecting an estimated 10% of women within the reproductive age demographic globally, endometriosis continues to present as a multifaceted and formidable challenge. The precise etiology remains elusive, leading to extended diagnostic intervals and personalized, often inadequate, therapeutic approaches. The intrinsic heterogeneity of endometriosis, evident in its varied phenotypes and clinical manifestations, further complicates both precise diagnosis and efficacious treatment. Conventional management hinges on hormonal interventions, which may not be appropriate for women desiring conception or for those experiencing substantial adverse effects. While surgical procedures are accessible, they do not provide a conclusive resolution, and the probability of recurrence remains high. Progress in diagnostic methodologies, such as non-invasive biomarker analyses, combined with an expanding understanding of the molecular and immunological frameworks that underpin the condition, presents promising prospects for the development of more targeted and individualized non-hormonal treatment modalities in the near future. Full article

The mechanical characteristics of soil–rock mixtures (S-RMs) are essential for ensuring geotechnical engineering stability and are significantly influenced by the microstructure’s contact network configuration. Due to the irregularity of particle shapes and the variability in particle grading with S-RMs, their macro-mechanical characteristics and mesoscopic contact skeleton distribution exhibit increased complexity. To further elucidate the macro-mesoscopic mechanical behavior of S-RMs, this study employed the DEM to develop a model incorporating irregular specimens representing various states, based on CT scan outlines, and applied flexible boundary conditions. A main skeleton system of contact force chains is an effective methodology for characterizing the dominant structural features that govern the mechanical behavior of soil–rock mixture specimens. The results demonstrate that the strength of S-RMs was significantly influenced by gravel content and consolidation state; however, the relationship is not merely linear but rather intricately associated with the strength and distinctiveness of the contact force chain skeleton. In the critical state, the mechanical behavior of S-RMs was predominantly governed by the characteristics of the principal contact force skeleton: the contact force skeleton formed by gravel–gravel, despite having fewer contact forces, exhibits strong contact characteristics and an exceptionally high-density distribution of weak contacts, conferring the highest shear strength to the specimens. Conversely, the principal skeleton formed through gravel–sand exhibits contact characteristics that are less distinct compared to those associated with strong contacts. Simultaneously, the probability density distribution of weak contacts diminishes, resulting in reduced shear strength. The contact skeleton dominated by sand–sand contact forces displays similar micro-mechanical characteristics yet possesses the weakest macroscopic behavior strength. Consequently, the concept of the main skeleton of contact force chains utilized in this study presents a novel research approach for elucidating the macro- and micro-mechanical characteristics of multiphase media. Full article

Multi-hop routing over low-power wide-area networks (LPWANs) has emerged as a promising technology for extending network coverage. However, existing protocols face high transmission disruption risks due to factors such as dynamic topology driven by stochastic events, dynamic link quality, and coverage holes induced by imbalanced energy consumption. To address this issue, we propose a failure risk-aware deep Q-network-based multi-hop routing (FRDR) protocol, aiming to reduce transmission disruption probability. First, we design a power regulation mechanism (PRM) that works in conjunction with pre-selection rules to optimize end-device node (EN) activations and candidate relay selection. Second, we introduce the concept of routing failure risk value (RFRV) to quantify the potential failure risk posed by each candidate next-hop EN, which correlates with its neighborhood state characteristics (i.e., the number of neighbors, the residual energy level, and link quality). Third, a deep Q-network (DQN)-based routing decision mechanism is proposed, where a multi-objective reward function incorporating RFRV, residual energy, distance to the gateway, and transmission hops is utilized to determine the optimal next-hop. Simulation results demonstrate that FRDR outperforms existing protocols in terms of packet delivery rate and network lifetime while maintaining comparable transmission delay. Full article

We discuss different quench protocols for Ising and XY spin chains in a transverse magnetic field. With a sudden local magnetic field quench as a starting point, we generalize our approach to a large class of local non-sudden quenches. Using finite time path field theory (FTPFT) perturbative methods, we show that the difference between the sudden quench and a class of quenches with non-sudden switching on the perturbation vanishes exponentially with time, apart from non-substantial modifications that are systematically accounted for. As the consequence of causality and analytic properties of functions describing the discussed class of quenches, this is true at any order of perturbation expansion and thus for the resummed perturbation series. The only requirements on functions describing the perturbation strength switched on at a finite time $t=0$ are as follows: (1) their Fourier transform $f\left(p\right)$ is a function that is analytic everywhere in the lower complex semiplane, except at the simple pole at $p=0$ and possibly others with $\Im \left(p\right)<0$; and (2) $f\left(p\right)/p$ converges to zero at infinity in the lower complex semiplane. A prototypical function of this class is $tanh\left(\eta t\right)$, to which the perturbation strength is proportional after the switching at time $t=0$. In the limit of large $\eta$, such a perturbation approaches the case of a sudden quench. It is shown that, because of this new type of universal behavior of Loschmidt echo (LE) that emerges in an exponentially short time scale, our previous results for the sudden local magnetic field quench of Ising and XY chains, obtained by the resummation of the perturbative expansion, extend in the long-time limit to all non-sudden quench protocols in this class, with non-substantial modifications systematically taken into account. We also show that analogous universal behavior exists in disorder quenches, and ultimately global ones. LE is directly connected to the work probability distribution, and the described universal behavior is therefore appropriate in potential concepts of quantum technology related to spin chains. Full article

A detailed statistical analysis of the total active reflection coefficient (TARC) is carried out in this paper for three 4-port MIMO antennas featuring different levels of isolation across its ports. This analysis is very useful to determine the most likely performance of a MIMO antenna in a real communications scenario. The TARC parameter is commonly evaluated for only several combinations of the random phase with which a signal reaches every input port of a MIMO antenna. By contrast, we have evaluated a million combinations to obtain the probability density function of the TARC, using frequency as its parameter. In this way, an expected value of the TARC is obtained for each frequency, as well as a confidence interval ($\Delta C{I}_{\mathrm{TARC}}$) where the TARC values occur with 90% probability. Additionally, we have introduced the term “TARC shadow”, a visual representation of the TARC as a function of the frequency where the probability function is projected into this 2D graphic with different colors to identify the most likely values of the TARC. To demonstrate these concepts, a full TARC evaluation was performed for three 4-port MIMO antennas with increasing isolation of 12.9 dB, 25.4 dB, and 37 dB between elements, and different values of the $S_{nn}$ and $S_{nm}$ parameters, with n and $m=$ 1 to 4. From this study, the importance of the isolation among ports and its comparison with the return losses becomes evident in achieving a MIMO antenna array insensitive to random phase variations occurring in the communication channel. Full article

Additive manufacturing (AM) has been gaining increased traction in the manufacturing industry due to its ability to fabricate prototypes and end use parts in low volumes at a much lower cost compared to conventional manufacturing processes. There has been research to select an AM process appropriate for fabricating particular parts. However, there is little extant research to select appropriate AM machines even though there is a growing number of AM machines with interesting topologies, structures, and systems. This paper proposes a methodology that aims to assist Technical Experts in selecting a machine for Fused Filament Fabrication (FFF). The methodology is built around a weighted Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), which uses the concept of relative closeness and attribute weights to rank the machines. The paper uses Monte Carlo simulations for sensitivity analysis to evaluate the impact of randomizing attribute scoring, perturbing weights assigned, and probability distributions used to model human decision variability. The methodology and the sensitivity analysis were applied to three case studies, with five FFF machines and seven attributes, and top machines ranked for a specific part were found to be largely robust. Full article

The deterioration of European freshwater ecosystems, driven by habitat fragmentation and connectivity loss, seriously threatens biodiversity and ecosystem integrity. While restoration efforts often focus on reconnecting river networks, ecological assessments tend to overlook the broader concept of connectivity. This study highlights the need to incorporate ecological quality into connectivity assessments, ensuring more effective restoration that is aligned with European Union (EU) conservation policies. Using the dendritic connectivity index for potamodromous (DCIp) species, we analysed seven connectivity scenarios, integrating natural and artificial barriers to assess both structural connectivity and quality-weighted connectivity. These scenarios included: (1) structural connectivity considering only natural barriers (S_NB) and (2) all barriers (S_AB); (3) quality-weighted connectivity considering natural barriers (W_NB), and (4) all barriers (W_AB); three enhanced scenarios considering all barriers with (5) improved quality (W_AB_IQ), (6) improved probability of connectivity (W_AB_IC), and (7) improved quality and probability of connectivity (W_AB_IQC). Connectivity values varied across scenarios, with the natural baseline (S_NB) showing the highest connectivity values (mean = 0.98). When the natural baseline was weighted by the GES probability (W_NB), connectivity values dropped considerably (mean = 0.30). Incorporating all barriers (W_AB) further reduced the connectivity values (mean = 0.26). The improved scenario W_AB_IQC showed notable connectivity improvements (mean = 0.40). This study underscores the importance of integrating ecological quality into river connectivity assessments. It demonstrates that restoring habitat quality alongside connectivity restoration can substantially enhance river ecosystems. Prioritising restoration in high-quality areas maximises ecological and social benefits, supports sustainable river management, improves connectivity, and promotes biodiversity conservation. Full article

Objectives: Most studies assess risk factors for common bile duct (CBD) stones in patients with gallbladder in situ. We aimed to assess risk factors for CBD stones in patients with previous cholecystectomy in a proof-of-concept study. Methods: We enrolled consecutive patients undergoing EUS for suspected symptomatic CBD stones and recorded demographic variables, clinical presentation, liver function tests (LFTs), and transabdominal ultrasound (US) findings. EUS was used as gold standard for CBD stones. Multivariate analysis was used to identify risk factors in the training set; a model was created and tested on the validation set. Results: A total of 211 patients (25.6% male; median age, 66 [49–75] years old) were enrolled; 77.7% presented with abdominal pain, 30.3% with hyperbilirubinemia, 26.5% with pancreatitis, and 61.1% with LFT alterations. Ultrasound showed CBD dilation in 37.4% patients. Overall, 96 (45.5%) patients had CBD stones. According to multivariate analysis, male gender (OR 2.54 [1.26–5.09]; p = 0.009), age > 63 years (OR 3.06 [1.63–5.72]; p < 0.001), LFT alteration (OR 2.62 [1.40–4.91]; p = 0.003), and CBD dilation (OR 2.46 [1.31–4.65]; p = 0.005) were independently related to CBD stones. A model was created based on the number of risk factors on admission; patients with no risk factor had a 9.5% prevalence of CBD stones; those with one risk factor, 26.7%; two risk factors, 53.2%; three risk factors, 66.7%; and four risk factors, 100%. Conclusions: The results of this proof-of-concept study identify male gender, age, LFT alteration, and CBD dilation as risk factors for CBD stones in patients with previous cholecystectomy. An adequate assessment of the pre-test probability will guide patients’ subsequent management. Full article

Ensuring the security of agricultural systems is essential for achieving national food security and sustainable development. Given that agricultural systems are inherently complex and composed of coupled subsystems—such as water, land, and energy—a comprehensive and multidimensional assessment of system security is necessary. This study focuses on Northeast China, a major food-producing region, and introduces the concept of agricultural system coupling security, defined as the integrated performance of an agricultural system in terms of resource adequacy, internal coordination, and adaptive resilience under external stress. To operationalize this concept, a coupling security evaluation framework is constructed based on three key dimensions: reliability (Rel), coordination (Cor), and resilience (Res). An Agricultural System Coupling Security Index (AS-CSI) is developed using the entropy weight method, the Criteria Importance Through Intercriteria Correlation (CRITIC) method, and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method, while obstacle factor diagnosis is employed to identify key constraints. Furthermore, bivariate and trivariate Copula models are used to estimate joint risk probabilities. The results show that from 2001 to 2022, the AS-CSI in Northeast China increased from 0.38 to 0.62, indicating a transition from insecurity to relative security. Among the provinces, Jilin exhibited the highest CSI due to balanced performance across all Rel-Cor-Res dimensions, while Liaoning experienced lower Rel, hindering its overall security level. Five indicators, including area under soil erosion control, reservoir storage capacity per capita, pesticide application amount, rural electricity consumption per capita, and proportion of agricultural water use, were identified as critical threats to regional agricultural system security. Copula-based risk analysis revealed that the probability of Rel–Cor reaching the relatively secure threshold (0.8) was the highest at 0.7643, and the probabilities for Rel–Res and Cor–Res to reach the same threshold were lower, at 0.7164 and 0.7318, respectively. The probability of Rel–Cor-Res reaching the relatively secure threshold (0.8) exceeds 0.54, with Jilin exhibiting the highest probability at 0.5538. This study provides valuable insights for transitioning from static assessments to dynamic risk identification and offers a scientific basis for enhancing regional sustainability and economic resilience in agricultural systems. Full article

Since Shannon’s pioneering work, the concept of entropy has been used in many major scientific fields. It is therefore a universal concept but also defined in different ways. Entropy is used in studies of system complexity and to investigate the information content of probability distributions. One of the areas of its applications is human lifespan, i.e., the link between entropy and the methods of survival analysis. These methods are also used in assessing the duration of any socio-economic phenomenon. The aim of this article is to assess the market situation on the basis of the entropy of duration in unemployment. This study determines the Shannon entropy, residual entropy, past entropy, and cumulative residual entropy under the assumption of an exponential distribution of duration. Ward’s hierarchical clustering and the Dynamic Time Warping measure were used to analyse entropy and its relationship with the unemployment rate. It was shown that not all of the analysed models determine the entropy of duration in unemployment well for an exponential distribution. It was substantiated that there is a similarity between the formation of the entropy of duration in unemployment and the registered unemployment rate. It is shown that high unemployment rates in the labour market are a destabilising element of the labour market, more so than crises. Full article

The Shu-Sarysu Basin in central-southern Kazakhstan remains one of the underexplored gas-prone provinces, with 12 discovered gas fields including Amangeldy (884 Bcf) and Pridorozhnoye (225 Bcf). In the context of global energy transition, such basins require integrated geological assessment to constrain exploration potential. Historical studies within the region were spatially limited and prematurely discontinued, resulting in fragmented datasets and a lack of modern interpretation. This review reassesses published geological data within a petroleum systems framework, applying contemporary geodynamic and stratigraphic concepts. Analysis shows that tectonostratigraphic evolution of the basin during Devonian–Permian time (390–250 Ma) favored formation of mature, gas-prone systems within structurally compartmentalized troughs, with effective source, reservoir, and seal configurations. Building on these findings, a three-tier classification of exploration zones is proposed based on system maturity, trap integrity, and gas shows, reflecting geological success probability. This provides a basis for prioritizing future exploration despite limited seismic and drilling coverage in many areas. Recommended priorities include digitization of archival data, structural modeling, modern geochemical and diagenetic analysis, and focused evaluation of promising areas to support future exploration. Full article

The Quality by Design (QbD) concept has been widely applied to the optimization of traditional Chinese medicine production processes recently. This work focused on optimizing the critical purification process of Scutellaria baicalensis extract used in the preparation of Zhusheyong Shuanghuanglian. Considering the impact of noise parameters and changes in herbal properties, an experimental design method was employed for optimization. Multiple batches of Scutellaria baicalensis decoction were prepared in this research, and quantitative models of Scutellaria baicalensis herbal properties, critical process parameters (CPPs), and process evaluation indicators were established. The R² of the quantitative models were all higher than 0.80. According to the model, the yield of baicalin was identified as a critical material property (CMA). The pH of first acid precipitation (X₁), first temperature holding time (X₂), pH of alkalization (X₃), ethanol amount (X₄), and end pH of ethanol washing (X₅) were CPPs. Considering the difficulty in controlling the end pH of the ethanol washing, it was considered to be a noise parameter. The Monte Carlo probability-based method was used to calculate the design space, determining the range of controllable parameters, which was successfully validated through experiments. Normal operation ranges for controllable parameters are recommended as follows: X₁ of 0.8–2.2, X₂ of 25–35 min, X₃ of 6.5–7.5, and X₄ of 0.8–1.2 g/g. Full article

This paper studies the important problem of quantum classification of Boolean functions from an entirely novel perspective. Typically, quantum classification algorithms allow us to classify functions with a probability of $1.0$, if we are promised that they meet specific unique properties. The primary objective of this study is to explore whether it is feasible to obtain any insights when the input function deviates from the promised class. For concreteness, we use a recently introduced quantum algorithm that is designed to classify a large class of imbalanced Boolean functions with probability $1.0$ using just a single oracular query. First, we establish a completely new concept characterizing “nearness” between Boolean functions. Utilizing this concept, we show that, as long as the unknown function is close enough to the promised class, it is still possible to obtain useful information about its behavioral pattern from the classification algorithm. In this regard, the current study is among the first to provide evidence that shows how useful it is to apply quantum classification algorithms to functions outside the promised class in order to get a glimpse of important information. Full article