Delay-Independent Stability Analysis of Linear Time-Delay Systems Based on Frequency

This paper studies strong delay-independent stability of linear time-invariant systems. It is known that delay-independent stability of time-delay systems is equivalent to some frequency-dependent linear matrix inequalities. To reduce or eliminate conservatism of stability criteria, the frequency domain is discretized into several sub-intervals, and piecewise constant Lyapunov matrices are employed to analyze the frequency-dependent stability condition. Applying the generalized Kalman–Yakubovich–Popov lemma, new necessary and sufficient criteria are then obtained for strong delay-independent stability of systems with a single delay. The effectiveness of the proposed method is illustrated by a numerical example

A neomorphic ossification connecting the braincase, squamosal, and quadrate in choristoderan reptiles: insights from µCT data

Choristoderes are extinct semi-aquatic to aquatic diapsid reptiles, occupying a similar niche as modern crocodilians from the Jurassic to the Miocene. Distinct from other diapsids, choristoderes have a neomorphic ossification between the braincase, squamosal, and quadrate. This neomorphic bone is described as thin and plate-like in long-snouted choristoderes (Neochoristodera), yet little is known about its presence and morphology in short-snouted non-neochoristoderes that are sister groups to Neochoristodera. Using X-ray micro-CT scanning, this study describes in detail the neomorph of two non-neochoristoderes, Coeruleodraco jurassicus and Philydrosaurus proseilus. The neomorph of both species is found between the parietal, quadrate, and squamosal. The shape of the neomorph resembles a pyramid in three-dimensions, with a triangular dorsal surface and a prominent ventral process. This confirms the neomorph is shared among early and late branching choristoderes; therefore, presence of the neomorph is a potential synapomorphy of Choristodera. In addition, the pterygoquadrate foramen is identified in non-neochoristoderes for the first time, located between the neomorph and quadrate in C. jurassicus. In the holotype of P. proseilus, the neomorph and quadrate were dislocated, but a possible pterygoquadrate foramen is identified between the two bones. Although the neomorph and pterygoquadrate foramen have been suggested to be homologous with the stapes and stapedial foramen in Champsosaurus, more evidences are required to confirm this homology in non-neochoristoderes, because 1) the neomorph is long and plate-like in neochoristoderes, but pyramid-shaped in non-neochoristoderes; 2) in Champsosaurus, the neomorph is situated lateral to the prootic and opisthotic; in C. jurassicus and P. proseilus, articulation between the neomorph and prootic (or opisthotic) cannot be confirmed due to damage to the braincase during preservation. To understand the origin of the neomorph, more intact specimens are needed to assess contact relationships between the neomorph and otic region in non-neochoristoderes

New nonmammalian eucynodont.

24, [1] p. : ill. (some col.), maps (some col.) ; 26 cm. "June 25, 2010." Includes bibliographical references (p. 19-21).A new trirachodontid eucynodont, Beishanodon youngi, is named and described based on a well-preserved skull from Triassic lacustrine deposits exposed in the Beishan Hills, northern Gansu Province, China. The new discovery documents the second record of trirachodontid eucynodonts known from China, along with Sinognathus gracilis from the Middle Triassic Ermaying Formation exposed in Shanxi Province. Cladistic analysis supports the placement of the new taxon as the sister group of Sinognathus, and the two together can be classified in Sinognathinae, a new subfamily differentiated from other trirachodontids by possession of several derived character states, including extremely short snout and strongly expanded temporal region. In addition, the stratigraphic and biogeographic significance of the new discovery are discussed. Because trirachodontids have a restricted stratigraphic range in the Triassic, as best documented by the Cynognathus Assemblage Zone of South Africa, discovery of the new fossil of this group from northern Gansu Province in China provides definitive evidence for a Triassic age of the fossil-bearing beds exposed in the Beishan Hills; moreover, the fossil beds are assessed as early Triassic in age based on the evidence from the entire vertebrate fauna

SPHINX: The Joint Mixing of Weights, Tasks, and Visual Embeddings for Multi-modal Large Language Models

We present SPHINX, a versatile multi-modal large language model (MLLM) with a joint mixing of model weights, tuning tasks, and visual embeddings. First, for stronger vision-language alignment, we unfreeze the large language model (LLM) during pre-training, and introduce a weight mix strategy between LLMs trained by real-world and synthetic data. By directly integrating the weights from two domains, the mixed LLM can efficiently incorporate diverse semantics with favorable robustness. Then, to enable multi-purpose capabilities, we mix a variety of tasks for joint visual instruction tuning, and design task-specific instructions to avoid inter-task conflict. In addition to the basic visual question answering, we include more challenging tasks such as region-level understanding, caption grounding, document layout detection, and human pose estimation, contributing to mutual enhancement over different scenarios. Additionally, we propose to extract comprehensive visual embeddings from various network architectures, pre-training paradigms, and information granularity, providing language models with more robust image representations. Based on our proposed joint mixing, SPHINX exhibits superior multi-modal understanding capabilities on a wide range of applications. On top of this, we further propose an efficient strategy aiming to better capture fine-grained appearances of high-resolution images. With a mixing of different scales and high-resolution sub-images, SPHINX attains exceptional visual parsing and reasoning performance on existing evaluation benchmarks. We hope our work may cast a light on the exploration of joint mixing in future MLLM research. Code is released at https://github.com/Alpha-VLLM/LLaMA2-Accessory.Comment: Work in progress. Code and demos are released at https://github.com/Alpha-VLLM/LLaMA2-Accessor

Prevalence and trend of hepatitis C virus infection among blood donors in Chinese mainland: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Blood transfusion is one of the most common transmission pathways of hepatitis C virus (HCV). This paper aims to provide a comprehensive and reliable tabulation of available data on the epidemiological characteristics and risk factors for HCV infection among blood donors in Chinese mainland, so as to help make prevention strategies and guide further research.</p> <p>Methods</p> <p>A systematic review was constructed based on the computerized literature database. Infection rates and 95% confidence intervals (95% CI) were calculated using the approximate normal distribution model. Odds ratios and 95% CI were calculated by fixed or random effects models. Data manipulation and statistical analyses were performed using STATA 10.0 and ArcGIS 9.3 was used for map construction.</p> <p>Results</p> <p>Two hundred and sixty-five studies met our inclusion criteria. The pooled prevalence of HCV infection among blood donors in Chinese mainland was 8.68% (95% CI: 8.01%-9.39%), and the epidemic was severer in North and Central China, especially in Henan and Hebei. While a significant lower rate was found in Yunnan. Notably, before 1998 the pooled prevalence of HCV infection was 12.87% (95%CI: 11.25%-14.56%) among blood donors, but decreased to 1.71% (95%CI: 1.43%-1.99%) after 1998. No significant difference was found in HCV infection rates between male and female blood donors, or among different blood type donors. The prevalence of HCV infection was found to increase with age. During 1994-1995, the prevalence rate reached the highest with a percentage of 15.78% (95%CI: 12.21%-19.75%), and showed a decreasing trend in the following years. A significant difference was found among groups with different blood donation types, Plasma donors had a relatively higher prevalence than whole blood donors of HCV infection (33.95% <it>vs </it>7.9%).</p> <p>Conclusions</p> <p>The prevalence of HCV infection has rapidly decreased since 1998 and kept a low level in recent years, but some provinces showed relatively higher prevalence than the general population. It is urgent to make efficient measures to prevent HCV secondary transmission and control chronic progress, and the key to reduce the HCV incidence among blood donors is to encourage true voluntary blood donors, strictly implement blood donation law, and avoid cross-infection.</p

Fig. 28 in Taxonomic Composition And Systematics Of Late Cretaceous Lizard Assemblages From Ukhaa Tolgod And Adjacent Localities, Mongolian Gobi Desert

Fig. 28. Scincomorpha, family incertae sedis, Slavoia darevskii: A, B, IGM 3/154, incomplete skull with mandible and partial postcranial skeleton from Khulsan, dorsal and ventral views; C, IGM 3/145, nearly complete skull with mandibles and partial postcranial skeleton from Ukhaa Tolgod, dorsal view D, IGM 3/146, incomplete skull with mandibles and articulated postcranial skeleton from Ukhaa Tolgod dorsal view.Published as part of KEQIN, GAO & NORELL, MARK A., 2000, Taxonomic Composition And Systematics Of Late Cretaceous Lizard Assemblages From Ukhaa Tolgod And Adjacent Localities, Mongolian Gobi Desert, pp. 1-118 in Bulletin of the American Museum of Natural History 2000 (249) on page 87, DOI: 10.1206/0003-0090(2000)2492.0.CO;2, http://zenodo.org/record/535025

Fig. 29 in Taxonomic Composition And Systematics Of Late Cretaceous Lizard Assemblages From Ukhaa Tolgod And Adjacent Localities, Mongolian Gobi Desert

Fig. 29. Globaura venusta: A–C, IGM 3/164, nearly complete skull with mandibles from Khulsan, dorsal, ventral, and right lateral views; D–F, IGM 3/160, nearly complete skull with mandibles from Ukhaa Tolgod, dorsal, ventral, and left lateral views.Published as part of KEQIN, GAO & NORELL, MARK A., 2000, Taxonomic Composition And Systematics Of Late Cretaceous Lizard Assemblages From Ukhaa Tolgod And Adjacent Localities, Mongolian Gobi Desert, pp. 1-118 in Bulletin of the American Museum of Natural History 2000 (249) on page 88, DOI: 10.1206/0003-0090(2000)2492.0.CO;2, http://zenodo.org/record/535025

Taxonomic Composition And Systematics Of Late Cretaceous Lizard Assemblages From Ukhaa Tolgod And Adjacent Localities, Mongolian Gobi Desert

KEQIN, GAO, NORELL, MARK A. (2000): Taxonomic Composition And Systematics Of Late Cretaceous Lizard Assemblages From Ukhaa Tolgod And Adjacent Localities, Mongolian Gobi Desert. Bulletin of the American Museum of Natural History 2000 (249): 1-118, DOI: 10.1206/0003-0090(2000)2492.0.CO;2, URL: http://www.bioone.org/doi/abs/10.1206/0003-0090%282000%29249%3C0001%3ATCASOL%3E2.0.CO%3B