Applied Radar (United States)

ABSTRACT Ten percent of Quebec’s territory is covered by freshwater. With tens of thousands of rivers and over three million bodies of water, Quebec has 3% of the planet’s renewable freshwater reserves. This abundance should protect the Quebec population from water stress and guarantee a certain level of water security. However, despite the solid legal framework governing water resources, problems linked to human activity and climate change are threatening water quality and water security. This article examines how Quebec law ensures water security and looks at the various institutional and legal mechanisms established to guarantee the human right to water.

<title>Abstract</title> <bold>Objective</bold> To evaluate the quality, safety, and clinical utility of AI-generated radiology impressions compared with human-authored impressions across multiple clinical stakeholder groups. <bold>Materials &amp; Methods</bold> A retrospective, blinded evaluation was conducted using 200 oncologic computed-tomography reports from a U.S. academic cancer center. Three impression types were assessed for each report: original radiologist-authored impressions, impressions generated by a custom domain-specific AI model fine-tuned on institutional data, and impressions generated by a general-purpose large language model. Original authoring radiologists, independent radiologists, and oncologists evaluated impressions using structured Likert-scale metrics assessing completeness, correctness, conciseness, clarity, clinical utility, and potential patient harm. Pairwise comparisons were performed using Wilcoxon signed-rank and two-proportion z-tests. <bold>Results</bold> Custom model AI impressions demonstrated near parity with human-authored impressions across most quality metrics. Original radiologists rated their own impressions as slightly more complete, while independent radiologists showed no significant differences between original and custom model impressions. Generic model impressions were longer, rated as more complete but significantly less concise. Patient harm ratings were uniformly low. Radiologists preferred original and custom model impressions over generic model impressions, whereas oncologists showed no significant preference. <bold>Discussion</bold> Evaluation outcomes varied by stakeholder group, highlighting differing priorities between radiologists and oncologists. Low inter-rater agreement across several quality metrics suggests that impression quality is inherently subjective and context dependent rather than defined by a single objective standard. <bold>Conclusion</bold> AI-generated radiology impressions, particularly those produced by custom domain-specific models, can achieve quality and safety comparable to human-authored impressions. These findings support the use of AI as an adaptable drafting aid that complements radiologist judgment.

The combination of clutter cancellation and adaptive Doppler estimation are examined in the context of random pulse repetition interval (PRI) staggering, which permits a greatly expanded unambiguous Doppler span, albeit at the cost of higher sidelobes. It is shown that estimation of movers otherwise masked by clutter or the sidelobes of other larger movers can be uncovered by this combination, with adaptive estimation being particularly useful at suppressing the attendant increase in sidelobes. Using the re-iterative super-resolution (RISR) method as a representative method for adaptive estimation (a variety exists), the efficacy of this combination is demonstrated using both simulated data and open-air measurements. A clairvoyant form of signal-to-interference-plus-noise ratio (SINR) is also used to assess analytically the behavior observed in simulation, particularly the loss trade-space between straddling and super-resolution.

Measles is a highly contagious, vaccine-preventable infectious disease. The incidence of measles has been rising due to a confluence of factors, including international travel and vaccine hesitancy. The purpose of this Pharmacotherapy Update was to examine and appraise preventive measures and treatment options, both pharmacotherapy and supplements, used in measles management. Topics included ribavirin, measles-mumps-rubella vaccine post-exposure prophylaxis, immune globulin, antibiotics, vitamin A, and cod liver oil supplements. Parents, caregivers, and policymakers considering these interventions are recommended to consult with health care providers and seek guidance from professional organizations regarding the effectiveness and safety of these treatments. Vaccination with the measles-mumps-rubella vaccine remains the most effective intervention to prevent measles, and efforts are urgently needed to achieve the requisite 95% vaccination rate to improve public health, confer herd immunity, and eradicate measles.

A uniform pulse repetition interval (PRI) introduces blind ranges due to transmit/receive (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{T} \boldsymbol{/} \mathbf{R}$</tex>) switching, in addition to range-Doppler ambiguities. Changing the pulse repetition frequency (PRF) on a scan-to-scan basis mitigates blind ranges, but at the cost of requiring multiple scans. Alternatively, introducing staggering at the PRI level permits the avoidance of blind ranges without the need for multiple scans, while also providing an expansion of unambiguous Doppler, though doing so also requires more sophisticated receive processing to sufficiently address the increased Doppler sidelobes. It has recently been shown that PRI staggering can be optimized to flatten the extended Doppler response. In contrast, here we explore optimization to achieve a flattened energy distribution in range for the purpose of mitigating blind ranges. Diversification of pulse duration is also considered to determine its potential impact in this context.

Abstract An EF1 tornado was documented using photographs, a high-resolution video, and a mobile radar as it entered Selden, Kansas, on 24 May 2021. The kinematic structure of the tornadic wind field was presented by tracking lofted debris and analyzing single-Doppler velocities. Tracking of debris on the side of the tornado farthest from the observer was possible due to the transparent nature of the debris cloud. The analysis suggests that the circulation was axisymmetric with the maximum horizontal velocities located at low levels. The positive vertical velocities were strongest on the forward side of the tornado. The maximum vertical velocities were associated with a secondary vortex. For the first time, the dataset provided an opportunity to assess the orientation of a large, lofted debris based on the images recorded by a movie and compare these observations with the differential radar reflectivity (ZDR) recorded by a mobile polarimetric radar. The T-matrix calculations of wood boards yielded a mean ZDR that was negative and was also observed in the ZDR analysis suggesting a preference for lofted debris to be vertically oriented.

In this paper, we describe a ray-tracing method for spherical lenses and reestablish an equation for calculating the radiation pattern using a spherical lens based on previous literature by modifying the physical optics (PO) integral equation. Using this formula, we calculated the radiation pattern according to the size and point source distance of a single-medium spherical lens and a Luneburg lens. While both lenses showed that the beam width became narrower as the lens size increased, the side-lobe level decreased when the source was located on the surface of the lens in the case of the Luneburg lens and when the source was appropriately distanced from the lens surface in the case of the single-medium spherical lens. In addition, through the analysis of the focal length and the beam forming the focus when parallel rays are incident on a single-medium spherical lens, we show that a single-medium spherical lens with a refractive index of 1.4 to 1.5 can replace a complex Luneburg lens by placing the source at a distance of 0.4 λ to 0.5 λ from the lens surface.