Directional Distribution Research Articles

Spatial, Functional, and Constructive Analysis of the Water Resource at the Archaeological Center of Tipon, Cusco, Peru, 2023

The objective of this research is to analyze the spatial, functional, and constructive aspects of the water resource at the Archaeological Center of Tipon, given the lack of awareness towards the timely preservation of archaeological heritage, the deterioration of the terraces, and the contamination of the rivers adjacent to the archaeological site due to the discharge of waste into the water bodies. The methodology employed consists of a site study analysis, considering data on terrain, environment, climate, and water flow in the spatial, functional, and constructive aspects, supported by digital tools (Google Earth Pro 2024, AutoCAD 2024, SketchUP 2024, Sun Path 3D 2024, Photoshop 2024, and Twinmotion 2024). The results yielded a spatial–functional–constructive hydrological analysis; the water flow, constructed underground through a masonry system with an approximate angle of 60° in stone or pink granite, also maintained a negative slope, generally between 1% and 3%, which facilitated a rapid and direct distribution, presenting a greater flow with a width and depth of 30 cm, in addition to a vertical drop of 240 cm. The efficient use of water in agriculture through interconnected terraces ensured the population’s sustenance by approximately 80%. In conclusion, the analysis not only provides information on the infrastructure and water management but also addresses current issues.

Modeling Airflow and Temperature in a Sealed Cold Storage System for Medicinal Plant Cultivation Using Computational Fluid Dynamics (CFD)

Effective air circulation is crucial for plant growth, requiring adequate airflow and environmental stability. This study utilized Computational Fluid Dynamics (CFD) to analyze airflow patterns in a controlled testing chamber, focusing on how miniature fan placement affects airflow direction and temperature distribution. Ten case studies were conducted, with the CFD model validated against experimental data collected from six monitoring locations on the plant growth table. Model validation was performed using statistical analyses including coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE). The validation results showed strong agreement between simulated and experimental data, with R2 values of 0.92 for temperature and 0.89 for airflow velocity. Statistical analysis showed significant differences in both airflow and temperature models at the 0.05 level, with the CFD model validation yielding an RMSE of 2.02 and an average absolute error of 1.17. Among the tested configurations, case M1 achieved the highest air velocity (0.317 m/s) and lowest temperature (27.03 °C), compared to M2 (0.255 m/s, 27.17 °C) and M3 (0.164 m/s, 27.18 °C). The temperature variations between cases significantly impacted cold storage efficiency, with case M1’s superior airflow distribution providing more uniform cooling. These findings offer practical guidelines for optimizing ventilation system design in medicinal plant cultivation facilities, particularly in maintaining ideal storage conditions through strategic fan placement and airflow management.

Swirling instability of viscous liquid jets with axial shear effect in gas surroundings

Linear instability analysis of a viscous swirling liquid jet surrounded by ambient gas is carried out by considering the significant influence of axial shear effect. The jet azimuthal flow is assumed as a Rankine vortex, and the non-uniform velocity distribution in the jet axial direction is approximated by parabolic and error functions. The enhancement of jet rotation is found to promote the predominant mode with larger azimuthal wavenumbers, and the mode transition is decided by the competition between centrifugal force and axial shear stress. Subsequently, the influence of the axial shear effect is examined through changing the degree of shear stress and the thickness of the gas velocity boundary layer. It is found that an increase of jet average velocity or surface velocity in the axial direction leads to the predominant mode transition to smaller azimuthal wavenumbers, due to the combined effects of shear stress and gas pressure perturbation. A larger velocity difference between ambient gas and liquid jet also promotes the predominant modes with smaller azimuthal wavenumbers, and the physical mechanism is attributed to gas pressure perturbation. Phase diagrams of different azimuthal modes are given and compared with the study of Kubitschek & Weidman (J. Fluid Mech., vol. 572, 2007, pp. 261–286), where a static swirling column without axial shear stress was considered. The strengthened axial shear effect is found to delay the transition of predominant modes with the increase of angular velocity. Experimental studies considering the swirling jets with different axial velocities are further carried out, which validate the theoretical findings. Different instability mechanisms and their transition rules are also identified through energy budget analysis. This study is expected to give scientific guidance on understanding the instability mechanisms of the swirling jets that widely exist in natural phenomena and engineering applications.

Temporal variation in utilisation distribution and direction distribution of dugong feeding trails in intertidal seagrass beds in Talibong Island, Thailand: an insight into dugong feeding routes

Context A better understanding of animal habitat use informs fundamental ecology and can provide underpinnings for effective management. Aims This study explored the temporal variation in feeding ground utilisation by dugongs (Dugong dugon) in two intertidal seagrass beds in Talibong Island, Thailand (Sites A and B), focusing on the distribution and direction of dugong feeding trails. Methods Drone-based aerial photography was conducted quarterly over 1 year and daily over 2 weeks to observe feeding trails and behaviour. Key results During five and seven separate photography periods over 1 year, 0.04 ± 0.01% (range: 0.03–0.06%) of Site A (200,000 m2) was covered with new feeding trails daily, while 0.35 ± 0.31% (range: 0.07–0.96%) of Site B (278,000 m2) was covered daily. This temporal variation in the feeding trail area corresponded to that in seagrass coverage. Daily observations over 2 weeks during six separate photography periods revealed a significant decrease in overlapping rates (intersection over union) of the core areas (50% kernel density estimation [KDE]) as time elapsed. The 1-year observation highlighted relatively higher overlapping rates of home ranges (95% KDE) (Site A: 0.27 ± 0.09; Site B: 0.49 ± 0.08) and low overlapping rates of core areas (Site A: 0.02 ± 0.03; Site B: 0.09 ± 0.09). The relative frequencies of the feeding trail direction remained consistent across survey seasons, and the most and least dominant directions were common across all survey seasons and sites. The circular correlation coefficient between the directions of dugong body axis and the estimated tidal current was 0.45, suggesting that feeding generally occurred in the upstream direction. The direction and spatial range of dugong feeding may be affected by temporally consistent factors. One factor that can affect the feeding direction is the tidal current. Conclusions Overall, dugongs may feed and move within seagrass beds in a temporally consistent manner, even when there are shifts in feeding hotspots. Implications This research enhances our understanding of how dugongs utilise their feeding grounds and highlights the importance of not only identifying feeding hotspots but also predicting their feeding routes by considering the direction and distribution of feeding trails.

The spatio-temporal characteristics and dynamic evolution of coupling and coordinated development of innovation factor allocation and green economy in China

IntroductionMeasuring the coupling coordination degree between the innovation factor allocation system and the green economy development system, and deeply exploring the changing trends in the coupling coordination between innovation factors allocation, including their subsystems, and green economy development, are essential prerequisites for achieving a high degree of coupling coordination between the two systems.MethodsThis paper, based on panel data from 30 provincial regions in China from 2013 to 2022, measures the coupling coordination degree between innovation factor allocation and green economy development, including their subsystems, and explores the spatial differentiation characteristics of this coupling coordination across the provinces in China and its three major regions. First, an evaluation index system for the innovation factor allocation system and the green economy development system is constructed from both input and output perspectives. The entropy weighted TOPSIS method and the coupling coordination degree model are then employed to explore the temporal characteristics of the coupling coordination between innovation factor allocation and green economy development. Second, Dagum's Gini coefficient is used to reveal the directional distribution of coupling coordination and the sources of spatial disparities. Third, kernel density estimation and spatial Markov chain methods are applied to uncover the dynamic evolution of this coupling coordination.Results and discussionThe study finds that the overall coupling coordination degree between innovation factor allocation and green economy development in China is relatively low, but it exhibits a continuous upward trend. From the perspective of regional disparities, the coupling level between innovation factor allocation and green economy development across Chinese provinces shows an imbalanced spatial distribution, characterized by higher levels in the east and lower levels in the west, with spatial disparities tending to widen. Inter-regional differences are the primary source of these spatial disparities, followed by intra-regional differences. While internal disparities within Eastern China are narrowing, they are expanding within the Central and Western China. The development processes in these regions are often influenced by neighboring spatial spillover effects. Finally, recommendations are proposed to enhance the coupling coordination degree between innovation factor allocation and green economy development in China.

Effectivess of Structured Teaching Programme on Skipping Meals among Nursing Students

The practice of skipping meals is prevalent among nursing students, often due to the pressures of academic and clinical schedules. This study evaluates the effectiveness of a structured teaching program designed to address the knowledge, attitudes, and practices related to meal-skipping among nursing students. A quasi-experimental design was used, involving a pre-test and post-test assessment of 60 nursing students from nursing college. Data on meal-skipping behaviors, nutritional knowledge, and health attitudes were collected using a validated questionnaire. The intervention included educational sessions on the importance of balanced nutrition, the effects of skipping meals on health and academic performance, and strategies for effective meal planning. Post-intervention results revealed a significant increase in knowledge and a positive shift in attitudes toward regular meal consumption, with a substantial reduction in reported meal-skipping behaviors. Assess the effectiveness of structured teaching programme on skipping meals among nursing students. This was a quasi-experimental study where closed ended demographic questionnaire were given to 60 first year student to assess their current situation and self-administered knowledge questionnaire were used as a tool to access sleep hygiene and sleep quality respectively among those 60 first year nursing student by using purposive sampling technique. Data was collected by direct distribution of tools to each nursing student and data was analysed and results were interpreted by using quasi experimental statistics. The overall mean percentage knowledge score in the pre-test and post-test were 32.75 % and 72.3%, respectively. Enhancements in mean percentage score were found to be 39.55%. The results of the study showed that the overall mean percentage knowledge score in the pre-test and post-test were 32.75 % and 72.3%, respectively. Enhancements in mean percentage score were found to be 39.55%. The statistical paired ‘t’ test indicates that enhancement in the mean percentage knowledge score was found to be significant at 0.05 level for all the aspect under study. The association found to be totally significant between pre-test knowledge scores and selected socio demographic variables at 0.05 level (p<0.05). The study findings suggested that ppt assisted structured teaching program is an effective instructional method in improving the knowledge regarding Skipping Meal among nursing students.

Simulation of time-invariant three-dimensional Freak waves and their scattering identification based on the JONSWAP spectrum and Donelan direction function

Abstract The results of recent maritime accident investigations show that many maritime accidents are related to the attack of freak waves, which can sink ships instantaneously with colossal energy. To identify and forecast freak waves accurately and avoid the danger of freak waves to marine structures and people, we have conducted further research on freak waves. In this paper, we propose an efficient time-invariant three-dimensional (3-D) freak wave computational model to study the scattering characteristics of time-invarian 3-D freak waves and obtain a more explicit identification of their scattering differences. First, this paper adopts linear superposition method to simulate a 3-D random rough sea surface based on the JONSWAP wave spectrum and Donelan directional distribution function. Moreover, we analyze the effect of different angular frequencies on the simulated sea surface. At the same time, the Monte Carlo method is used to further simulate the capillary waves based on the random sea surface, and this method vastly improves the computational accuracy of the random sea surface. Then, based on the two-wave train superposition wave energy focusing mode, a numerical calculation method of time-invariant 3-D freak waves is proposed, and the time-series evolution process of 3-D freak waves is simulated. Finally, the backscattering coefficients of the 3-D freak wave surface are calculated using the two-scale method, and the electromagnetic scattering characteristics of the freak wave surface under different evolution stages, wind speeds, and radar incidence angles are analyzed. By this method, we conclude that the recognition of freak waves is more accurate under medium-high wind speed and significant incidence angle conditions. The experiments show that the research in this paper can identify and predict freak waves more effectively, further improve the forecast accuracy of future freak waves, and also have some application value for freak wave risk warnings.

Influence of particle density on turbulence characteristics over a rough surface

The objective of the study is to use a 3D Acoustic Doppler Velocimeter (ADV) to gauge the typical flow and turbulence characteristics within a non-uniform open channel. The findings of experimental examinations of the subcritical flow along the channel are presented in this work. The behavior of sand grains in turbulent open channel flow across porous and rough bed surfaces was examined in laboratory research, and the results were obtained. The properties of turbulent flow, i.e., turbulence intensity, turbulent kinetic energy, and Reynolds shear stresses, are determined from ADV data. The continuity equation and the Reynolds equation of open-channel flow have been used to build theoretical formulations for the velocity distribution and Reynolds stress distribution in the vertical direction. Measured profiles of vertical velocity and Reynolds stress are compared to the derived expressions. The impact of the size of particles on the distribution of mean flow characteristics is discussed. This work provides a novel origin for the profile and analyzes the behavior of the vertical velocity distribution in the region where fully formed turbulence is dominating in open channels using the Navier–Stokes equations. In comparison to other sand roughness, Chopan sand bed (with greater density) exhibits the strongest turbulence intensities in both vertical and streamwise direction just next to the bed when away from the channel boundary. In contrast to flow across a rough surface, the variance ranges between 150 and 250% concerning the channel bed’s roughness type, impacting the velocity triple products that signifies transfer of turbulent kinetic energy.

Kontribusi Lembaga Filantropi Islam Berbasis ZIS untuk Meningkatkan Kesejahteraan Masyarakat di Desa Adipura Kencana Kecamatan Sungai Bahar Kabupaten Muaro Jambi

This research explores the contribution of ZIS-based Islamic philanthropic institutions in improving community welfare in Adipura Kencana Village, Sungai Bahar Sub-district, Muaro Jambi District. The aim of this study is to understand the contributions, impacts, and efforts of ZIS-based Islamic philanthropic institutions in supporting business capital assistance programs in Sungai Bahar Sub-district, Muaro Jambi District. This research employs a descriptive qualitative method, using both primary and secondary data. Data collection techniques include observation, interviews, and documentation, while data analysis is conducted using domain, taxonomic, and componential analyses. The results indicate that direct fund distribution by the institution significantly strengthens the relationship and sense of kinship between the community and the philanthropic institution. Through direct interaction with the community, prospective aid recipients are more open in expressing their concerns and needs, making the assistance provided by the philanthropic institution highly beneficial. The community feels a considerable positive impact from the presence of Islamic philanthropic institutions managing zakat in their area, as many individuals are able to improve their welfare through productive enterprises thanks to the assistance provided by the institution. The institution carefully selects aid recipients to ensure that assistance reaches those who truly need it. However, some community members still feel they belong in the less-privileged category yet have not received assistance from the institution.

Analysis of the air gap magnetic field in cylindrical magnetic couplings based on mathematical and finite element approach

The air gap magnetic field of a magnetic coupling plays a crucial role in the examination of its static torque and eddy current losses. Precise characterization of the air gap magnetic field is essential for ensuring the accuracy of performance assessments of the magnetic coupling. This study focuses on the cylindrical magnetic coupling as the subject of investigation, employing mathematical analysis and finite element methods to evaluate and quantify the magnetic field properties. The study establishes a mathematical model of the magnetic field of a magnetic coupling based on electromagnetic field principles and the superposition theorem. An analytical formula for the magnetic flux density distribution of the air-gap magnetic field is derived. Subsequently, a three-dimensional magnetic field finite element model is created using the finite element method to numerically calculate the air gap magnetic field and validate the analytical formula. The research also explores the periodic distribution characteristics of the magnetic field in the air gap, analyzing axial differences in magnetic flux density value and direction distribution influenced by end effects.

On the Dynamism of Paintings Through the Distribution of Edge Directions.

The digitization of artworks has recently offered new computational perspectives on the study of art history. While much of the focus has been on classifying styles or identifying objects, the analysis of more abstract concepts, such as the perception of motion or dynamism in still images, remains largely unexplored. Semioticians and artists have long explored the representation of dynamism in still images, but they often did so through theoretical frameworks or visual techniques, without a quantitative approach to measuring it. This paper proposes a method for computing and comparing the dynamism of paintings through edge detection. Our approach is based on the idea that the dynamism of a painting can be quantified by analyzing the edges in the image, whose distribution can be used to identify patterns and trends across artists and movements. We demonstrate the applicability of our method in three key areas: studying the temporal evolution of dynamism across different artistic styles, as well as within the works of a single artist (Wassily Kandinsky), visualizing and clustering a large database of abstract paintings through PixPlot, and retrieving similarly dynamic images. We show that the dynamism of a painting can be effectively quantified and visualized using edge detection techniques, providing new insights into the study of visual culture.

Direction Finding Studies of Simultaneous Auroral 2fce and 3fce Roar Cyclotron Harmonic Radio Emissions

AbstractAuroral roar originates in Earth's ionosphere at altitudes of several hundred kilometers where the upper hybrid frequency matches a harmonic of the electron gyrofrequency. These radio emissions are important for remote sensing of ionospheric plasma conditions and processes, and their physics is similar to that of astrophysical radio emissions. In this study, direction finding was used to establish the distribution of direction of arrival (DOA) angles for the third harmonic emissions and to compare the direction angles of second harmonic and events when they occur simultaneously. Data were collected for 42 events from 9 May 2022 to 20 May 2023 by a three antenna array in Toolik Lake, AK (68.6°N, 149.6°W, 68.5° magnetic latitude) with a DOA distribution centered overhead. 30% of the events coming from the south, for which azimuth deviations due to refraction are less significant, were on the same azimuth within 10°, the uncertainty of the measurement. This is a lower bound on the fraction of simultaneous harmonic and emissions that come from the same auroral arc. All events coming from the south that had a and azimuth angle of arrival within 10° had a higher elevation than elevation within experimental uncertainty, supporting the mechanism by which these emissions are excited at the “double resonance” points on the bottomside of the ionosphere.

Bursty Star Formation in Dwarfs is Sensitive to Numerical Choices in Supernova Feedback Models

Simulations of galaxy formation are mostly unable to resolve the energy-conserving phase of individual supernova events, having to resort to subgrid models to distribute the energy and momentum resulting from stellar feedback. However, the properties of these simulated galaxies, including the morphology, stellar mass formed, and the burstiness of the star formation history, are highly sensitive to the numerical choices adopted in these subgrid models. Using the SMUGGLE stellar feedback model, we carry out idealized simulations of an M vir ∼ 1010 M ⊙ dwarf galaxy, a regime where most simulation codes predict significant burstiness in star formation, resulting in strong gas flows that lead to the formation of dark matter cores. We find that by varying only the directional distribution of momentum imparted from supernovae to the surrounding gas, while holding the total momentum per supernova constant, bursty star formation may be amplified or completely suppressed, and the total stellar mass formed can vary by as much as a factor of ∼3. In particular, when momentum is primarily directed perpendicular to the gas disk, less bursty and lower overall star formation rates result, yielding less gas turbulence, more disky morphologies, and a retention of cuspy dark matter density profiles. An improved understanding of the nonlinear coupling of stellar feedback into inhomogeneous gaseous media is thus needed to make robust predictions for stellar morphologies and dark matter core formation in dwarfs independent of uncertain numerical choices in the baryonic treatment.

Insight into the impact of fixed transition on the aerodynamic performance and noise of airfoils with varying airfoil thicknesses

To explore the effect of surface pollution on the aerodynamics and acoustics of airfoils, the aerodynamic performance and noise of Delft University of Technology (DU) airfoils with different relative thicknesses are simulated using the shear-stress transport k-ω model and large Eddy simulation. The sensitive positions of fixed transition for DU airfoils are examined in terms of aerodynamic performance and noise, and the variations in aerodynamic performance, noise, and internal flow are analyzed. The results show that the sensitive position of fixed transition is almost unaffected by the relative thickness of airfoils. In terms of aerodynamic performance and noise, the sensitive transition positions on the suction surface are located at 1%c and 5%c, respectively. Fixed transition leads to a reduction in the aerodynamic efficiency and an elevation in noise. The impact of fixed transition on the airfoil's trailing-edge noise far exceeds its effect on radiated noise. The original airfoil's noise exhibits a typical dipole-like directional distribution. However, after the fixed transition, the dipole distribution gradually blurs, and this trend becomes more pronounced with increasing relative thickness. Fixed transition reduces the stability of wake vortex shedding and increases the energy loss, and an increase in relative thickness enlarges the high vortex region and vortex size near the fixed transition.

Financial feasibility: developing and commercializing Turmeric Kombucha with the business model canvas

Turmeric Kombucha, a fermented drink combining the anti-inflammatory properties of turmeric, represents a promising product of functional beverage market. In order to successfully bring Turmeric Kombucha to market, it is essential to evaluate its commercialization potential. This involves assessing the Business Model Canvas (BMC) and financial feasibility metrics. This study aims to determine the feasibility and strategies for successfully commercializing Turmeric Kombucha for development a business plan with scale up the production of Turmeric Kombucha. The result indicate that Turmeric Kombucha has a viable business model with 9 elements. Based on financial shows that Net Present Value (NPV) of $ 13,405,417.62, an Internal Rate of Return (IRR) of 71.42 %, a Payback Period (PP) of 0.59 years, and Break-Even Point (BEP) metrics of 3,173 units and $ 4,914.46. The analysis shows strong financial viability and significant growth potential for Turmeric Kombucha, supported by sustainable and efficient supply chain partnerships. The features and characteristics of the obtained results in this study, namely: a) high consumer interest from health-conscious individuals over 18 years old; b) health benefits of Turmeric Kombucha include hepatoprotective, immunomodulatory, antidiabetic, and antioxidant properties; c) key resources include efficient production processes, user-friendly equipment, and adequate human and financial resources. The practical application of these results involves strategies for scale up of market expansion, quality standardization, and supply chain enhancement. Customer relationships are fostered through direct and indirect distribution channels such as marketplaces, word-of-mouth, and retail stores.

The Large-scale Anisotropy and Flux (de)magnification of Ultrahigh-energy Cosmic Rays in the Galactic Magnetic Field

We calculate the arrival direction distribution of ultrahigh-energy cosmic rays (UHECRs) with a new suite of models of the Galactic magnetic field (GMF), assuming sources follow the large-scale structure of the Universe. Compared to previous GMF models, the amplitude of the dipole component of the UHECR arrival flux is significantly reduced. We find that the reduction is due to the accidentally coinciding position of the peak of the extragalactic UHECR flux and the boundary of strong flux demagnification due to the GMF toward the central region of the Galaxy. This serendipitous sensitivity of UHECR anisotropies to the GMF model will be a powerful probe of the source distribution as well as Galactic and extragalactic magnetic fields. Demagnification by the GMF also impacts the visibility of some popular source candidates.

Simulation of PSDF (Photovoltaic, Storage, Direct Current and Flexibility) Energy System for Rural Buildings

The PSDF (photovoltaic, storage, direct current, and flexibility) energy system represents an innovative approach aimed at achieving carbon neutrality. This study focused on rural buildings and utilized Modelica to develop a dynamic simulation model of the PSDF system. The research introduced a framework for direct current distribution microgrid systems with flexible regulatory mechanisms, employing a virtual inertia control strategy to provide stable adjustments for flexible operations and support integration with local grids. Case simulation results indicated that the system equipped with a water tank saved 3.15 kWh compared to the system without a water tank, resulting in an energy savings rate of 22.14%. Compared to traditional photovoltaic systems, the PSDF system significantly enhanced energy management flexibility and system reliability through the integration of thermal storage and battery management. This research made significant contributions to the fields of renewable energy and building energy systems by offering a scalable and practical solution suitable for rural contexts.

Mesoscopic shear evolution characteristics of frozen soil-concrete interface

The mechanical properties of frozen-concrete interfaces affect the stability and durability of engineering structures in cold regions. To investigate these properties, laboratory tests and numerical simulations were conducted to study the mesoscopic evolution of the shear stress-displacement relationship and the shearing process at the interface. The direct shear tests were performed at different environmental temperatures (−2 °C, −5 °C, and −10 °C) and normal stresses (100 kPa, 200 kPa, and 300 kPa) on the frozen soil-concrete interface, and Particle Flow Code (PFC) model of direct shear was developed. The mesoscopic parameters (particle displacement, rotation, force chain, stress, coordination number, porosity, fabric, etc.) of the interface during shearing were simulated using the PFC model. Moreover, the relationship among the interface temperature, cohesion, and friction coefficient was determined based on experimental data, and the accuracy of the PFC model was verified using previous experimental data. The results of the PFC shear model aligned well with those of the laboratory test, and the formation of shear bands was simulated well. The displacement of the soil particles on the upper layer outside the shear zone was uniform, and the direction was the same, whereas the particles inside the shear zone showed significant differences in the dislocation and rotation of the soil particles. The force chain, stress field, coordination number, and porosity were similar in the shear process and showed a concentrated distribution in the opposite direction of the shear motion, which reflected the consistency of the microcosmic response of the particles under the action of macroscopic external forces. The regression equations for the temperature, cohesion, and friction coefficient in this study can be used to simulate the shear behavior of frozen soil-concrete interfaces under different temperatures and normal stresses.

Clinical benchmark dataset for AI accuracy analysis: quantifying radiographic annotation of pelvic tilt

Radiographic landmark annotation determines patients’ anatomical parameters and influences diagnoses. However, challenges arise from ambiguous region-based definitions, human error, and image quality variations, potentially compromising patient care. Additionally, AI landmark localization often presents its predictions in a probability-based heatmap format, which lacks a corresponding clinical standard for accuracy validation. This Data Descriptor presents a clinical benchmark dataset for pelvic tilt landmarks, gathered through a probabilistic approach to measure annotation accuracy within clinical environments. A retrospective analysis of 115 pelvic sagittal radiographs was conducted for annotating pelvic tilt parameters by five annotators, revealing landmark cloud sizes of 6.04 mm-17.90 mm at a 95% dataset threshold, corresponding to 9.51°–16.55° maximum angular disagreement in clinical settings. The outcome provides a quantified point cloud dataset for each landmark corresponding to different probabilities, which enables assessment of directional annotation distribution and parameter-wise impact, providing clinical benchmarks. The data is readily reusable for AI studies analyzing the same landmarks, and the method can be easily replicated for establishing clinical accuracy benchmarks of other landmarks.

Omnidirectional path loss model for non-line-of-sight ultraviolet communications.

To analyze the channel characteristics in omnidirectional reception scenarios for non-line-of-sight ultraviolet (UV) communication, we derive expressions for the reception direction distribution based on the incident photons at the receiver and propose an omnidirectional reception path loss (PL) channel model based on the Monte Carlo (MC) method. Furthermore, we validate the proposed omnidirectional model by comparing it with the existing MC numerical model that traverses all reception directions. Results indicate that the average computation time of the proposed omnidirectional PL model is less than 0.03% of the traversal model while maintaining comparable accuracy. Additionally, we present the variations in off-axis and inclination angles corresponding to the receiver's direction at different coordinate positions. Therefore, this paper provides valuable guidance for rapidly determining the omnidirectional energy field distribution and optimizing receiver orientation in UV communication systems.