Abstract: A media retention plate for an underdrain system having one or more filter blocks. The plate can include a first slot configured to allow the passage of air and a second slot configured to allow the passage of water during an air backwash. The media retention plate is configured to facilitate the water to flow back into the one or more filter blocks through the second slot while maintaining air flow through the first slot to create an optimal collapse pulse. The first and second slots are evenly sized and evenly spaced apart to facilitate the creation of a relatively smaller-sized collapse pulse during a sequential air-water backwash. A plurality of inserts can be arranged along a perimeter of a basal portion of the bottom surface of the media retention plate. The inserts improve the structural integrity of and prevent uplift of the media retention plate.

Abstract: Methods, apparatuses, and systems for more efficiently assessing the performance of a person on a test or at completing a task. The disclosure is directed to systems, apparatuses, and methods for training a model to jointly predict (a) test item annotations (e.g., a domain or subject-matter expert's assessment of the difficulty level of a test item) and (b) test-taker responses. The disclosed approach may be used to estimate item parameters used in tests for evaluating the proficiency of a test taker, and more specifically, as part of a language proficiency test or examination.

Abstract: Systems, apparatuses, and methods for automatically generating text items that may be used on an exam or test. In some embodiments, the text items may take the form of a question or statement. The exam or test may be used for evaluating a test-taker's knowledge, proficiency, reading comprehension, or other similar purpose or goal.