Local Periodicity-Based Beat Tracking for Expressive Classical Piano Music

To model the periodicity of beats, state-of-the-art beat tracking systems use "post-processing trackers" (PPTs) that rely on several empirically determined global assumptions for tempo transition, which work well for music with a steady tempo. For expressive classical music, however, these assumptions can be too rigid. With two large datasets of Western classical piano music, namely the Aligned Scores and Performances (ASAP) dataset and a dataset of Chopin's Mazurkas (Maz-5), we report on experiments showing the failure of existing PPTs to cope with local tempo changes, thus calling for new methods. In this paper, we propose a new local periodicity-based PPT, called predominant local pulse-based dynamic programming (PLPDP) tracking, that allows for more flexible tempo transitions. Specifically, the new PPT incorporates a method called "predominant local pulses" (PLP) in combination with a dynamic programming (DP) component to jointly consider the locally detected periodicity and beat activation strength at each time instant. Accordingly, PLPDP accounts for the local periodicity, rather than relying on a global tempo assumption. Compared to existing PPTs, PLPDP particularly enhances the recall values at the cost of a lower precision, resulting in an overall improvement of F1-score for beat tracking in ASAP (from 0.473 to 0.493) and Maz-5 (from 0.595 to 0.838).Comment: Accepted to IEEE/ACM Transactions on Audio, Speech, and Language Processing (July 2023

Fine-grained Controllable Video Generation via Object Appearance and Context

Text-to-video generation has shown promising results. However, by taking only natural languages as input, users often face difficulties in providing detailed information to precisely control the model's output. In this work, we propose fine-grained controllable video generation (FACTOR) to achieve detailed control. Specifically, FACTOR aims to control objects' appearances and context, including their location and category, in conjunction with the text prompt. To achieve detailed control, we propose a unified framework to jointly inject control signals into the existing text-to-video model. Our model consists of a joint encoder and adaptive cross-attention layers. By optimizing the encoder and the inserted layer, we adapt the model to generate videos that are aligned with both text prompts and fine-grained control. Compared to existing methods relying on dense control signals such as edge maps, we provide a more intuitive and user-friendly interface to allow object-level fine-grained control. Our method achieves controllability of object appearances without finetuning, which reduces the per-subject optimization efforts for the users. Extensive experiments on standard benchmark datasets and user-provided inputs validate that our model obtains a 70% improvement in controllability metrics over competitive baselines.Comment: Project page: https://hhsinping.github.io/facto

Acute Fatty Liver of Pregnancy in a Taiwanese Tertiary Care Center: A Retrospective Review

SummaryObjectiveTo evaluate the demographics, clinical presentations, laboratory findings, and maternal and fetal outcomes in patients with acute fatty liver of pregnancy.Materials and MethodsA retrospective review was conducted of the records of pregnant patients with a diagnosis of acute fatty liver in a tertiary medical center over a 22-year period.ResultsEighteen patients with acute fatty liver of pregnancy were recruited, all of whom developed the disease in the third trimester. Eleven women (61%) were primigravid and four (22%) had twin pregnancies; six (33%) were diagnosed antepartum, and the other 12 (67%) were diagnosed postpartum. There were two maternal deaths (11%) and four fetal deaths (18%). The most common complications apart from severe liver dysfunction were acute renal failure (83%), hypoglycemia (61%), and disseminated intravascular coagulation (61%).ConclusionWomen who become acutely ill during the third trimester of pregnancy should undergo tests for acute fatty liver of pregnancy, including laboratory tests for assessing liver function and coagulation profile