176 research outputs found
Evaluation of a Simple DC-Balanced Encoding Method for LVDS Data Transmission Over CAT-5 Cable
In this study, a simple dc-balanced encoding scheme was developed to reduce the bit error rate for high-speed data transmission over CAT-5 cable using Low-voltage Differential Signaling (LVDS). The dc balance encoder was implemented to make binary sequences with a spectral null at zero. A data transmission controller using the dc balanced scheme was implemented in an Altera Field Programmable Gate Array (FPGA), including data generators that send data to a DS92LV1023 10-bit bus LVDS serializer, data checkers for checking the data coming from a DS92LV1224 10-bit bus LVDS deserializer, and dc balance and non-dc balance encoders. Data was transmitted over various lengths of CAT-5 cable with and without dc balance to determine the effect of the dc balance scheme on transmission errors.
To generalize the type of data used in the transmission tests, three different kinds were selected for the error testing: pseudo-random numbers generated by a 32-bit Linear Feedback Shift Register (LFSR) binary polynomial generator; consecutive numbers generated by a counter; and data looked-up from a Read Only Memory (ROM) implemented in an FPGA embedded memory block.
The data transmission controller was constructed, configured, and tested both with and without dc balance. It provides a data transmission rate of 538.8 Mbps, and is able to send the number of errors encountered during the transmission process to a PC via the PCI bus. Testing results verify that the dc balance scheme adopted in this thesis significantly improves the accuracy of the serial data transmission. Both dc-balanced and non-dc-balanced encoding proved error-free out to cable lengths of about 19.8 meters. DC-balanced encoding also extended the error-free cable length by about 1.5 meters and reduced errors by about 60% for longer cables
Lane Graph as Path: Continuity-preserving Path-wise Modeling for Online Lane Graph Construction
Online lane graph construction is a promising but challenging task in
autonomous driving. Previous methods usually model the lane graph at the pixel
or piece level, and recover the lane graph by pixel-wise or piece-wise
connection, which breaks down the continuity of the lane. Human drivers focus
on and drive along the continuous and complete paths instead of considering
lane pieces. Autonomous vehicles also require path-specific guidance from lane
graph for trajectory planning. We argue that the path, which indicates the
traffic flow, is the primitive of the lane graph. Motivated by this, we propose
to model the lane graph in a novel path-wise manner, which well preserves the
continuity of the lane and encodes traffic information for planning. We present
a path-based online lane graph construction method, termed LaneGAP, which
end-to-end learns the path and recovers the lane graph via a Path2Graph
algorithm. We qualitatively and quantitatively demonstrate the superiority of
LaneGAP over conventional pixel-based and piece-based methods on challenging
nuScenes and Argoverse2 datasets. Abundant visualizations show LaneGAP can cope
with diverse traffic conditions. Code and models will be released at
\url{https://github.com/hustvl/LaneGAP} for facilitating future research
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Decadal modulation of the relationship between tropical southern Atlantic SST and subsequent ENSO by Pacific Decadal Oscillation
This study identifies the relationship between tropical southern Atlantic (TSA) sea surface temperature anomaly (SSTA) and the El Niño-Southern Oscillation (ENSO) and focuses on how the Pacific Decadal Oscillation (PDO) modulates this relationship. Results suggest a significant but non-stationary interannual TSA-ENSO relationship which undergoes a significant decadal shift. A strong TSA-ENSO relationship is observed during the positive PDO phase, while this relationship is weak during the negative PDO phase. Two processes, involving the anomalous Pacific Walker circulation (PWC) and the intensity of air-sea interactions over the Pacific, are proposed for this decadal shift. During the positive PDO phase, the weak and variable PWC and strong air-sea interaction facilitate the development of SSTA in the tropical Pacific triggered by TSA SSTA, resulting in a strong TSA-ENSO relationship and vice versa. These findings emphasize the important role of the modulation of PDO on the TSA-ENSO relationship
Mesenchymal Stem Cell in the Intervertebral Disc
Degeneration of the intervertebral disc (IVD) is a major spinal disorder that causes back pain. Nucleus pulposus (NP) in the central of IVD dehydrates and become more fibrous in the IVD degeneration. NP cells undergo apoptosis with the degeneration of extracellular matrix (ECM) components. To replenish the NP cells and core ECM, bone marrow mesenchymal stromal cells (BMSCs) have been highlighted in the regeneration of IVD degeneration. BMSCs differentiate into NP-like cells with the secretion of ECM components, which may not only replenish the number of NP cells but also stimulate NP reconstruction. This further maintains tissue homeostasis. Up to date, the disc progenitor cells (DPCs) have been identified with the characteristics of multidifferentiation and stem cell phenotype. These cells are involved in the IVD diseases and show regenerative potentials. However, the differences between the BMSCs and DPCs remain elusive, in particular, the cellular connection in vivo. As such, this chapter will discuss the findings of the two cell types and propose a novel concept in the understanding of the biology of IVD
VADv2: End-to-End Vectorized Autonomous Driving via Probabilistic Planning
Learning a human-like driving policy from large-scale driving demonstrations
is promising, but the uncertainty and non-deterministic nature of planning make
it challenging. In this work, to cope with the uncertainty problem, we propose
VADv2, an end-to-end driving model based on probabilistic planning. VADv2 takes
multi-view image sequences as input in a streaming manner, transforms sensor
data into environmental token embeddings, outputs the probabilistic
distribution of action, and samples one action to control the vehicle. Only
with camera sensors, VADv2 achieves state-of-the-art closed-loop performance on
the CARLA Town05 benchmark, significantly outperforming all existing methods.
It runs stably in a fully end-to-end manner, even without the rule-based
wrapper. Closed-loop demos are presented at https://hgao-cv.github.io/VADv2.Comment: Project Page: https://hgao-cv.github.io/VADv
Hyaluronic acid ameliorates intervertebral disc degeneration via promoting mitophagy activation
Activation of mitophagy was considered to be a potential therapeutic strategy for intervertebral disc degeneration (IDD). There was evidence suggesting that hyaluronic acid (HA) can protect mitochondria from oxidative stress in chondrocytes, but its protective effects and mechanism in nucleus pulposus cells (NPCs) remain unclear. This study aimed to confirm the effect of HA promoting mitophagy and protecting mitochondria function in NPCs, and explore its underlying mechanism. NPCs were treated with high molecular weight HA, tert-butyl hydroperoxide (TBHP) and Cyclosporin A (CsA). Mitophagy, mitochondrial function, apoptosis, senescence and extracellular matrix (ECM) degradation were measured. Then, NPCs were transfected with C1QBP siRNA, mitophagy and mitochondrial function were tested. The therapeutic effects of HA on IDD by promoting mitophagy were assessed in bovine intervertebral disc organ culture model. The results showed that TBHP induced oxidative stress, mitochondrial dysfunction, NPCs apoptosis, senescence and ECM degradation. Treated by HA, mitophagy was activated, concomitantly, mitochondrial dysfunction, apoptosis, senescence and ECM degradation were ameliorated. Mitophagy inhibition by CsA partially eliminated the protective effects of HA against oxidative stress. After transfected with C1QBP siRNA to reduce the expression of C1QBP in NPCs, the effect of HA promoting mitophagy was inhibited and the protective effect of HA against oxidative stress was weaken. Additionally, HA alleviated NPCs apoptosis and ECM degradation in bovine intervertebral disc organ culture model. These findings suggest that HA can protect mitochondrial function through activation of mitophagy in NPCs and ameliorate IDD. Furthermore, C1QBP is involved in HA promoting mitophagy and protecting NPCs from oxidative stress. Taken together, our results provide substantial evidence for the clinical applications of HA in the prevention and treatment of IDD
VAD: Vectorized Scene Representation for Efficient Autonomous Driving
Autonomous driving requires a comprehensive understanding of the surrounding
environment for reliable trajectory planning. Previous works rely on dense
rasterized scene representation (e.g., agent occupancy and semantic map) to
perform planning, which is computationally intensive and misses the
instance-level structure information. In this paper, we propose VAD, an
end-to-end vectorized paradigm for autonomous driving, which models the driving
scene as a fully vectorized representation. The proposed vectorized paradigm
has two significant advantages. On one hand, VAD exploits the vectorized agent
motion and map elements as explicit instance-level planning constraints which
effectively improves planning safety. On the other hand, VAD runs much faster
than previous end-to-end planning methods by getting rid of
computation-intensive rasterized representation and hand-designed
post-processing steps. VAD achieves state-of-the-art end-to-end planning
performance on the nuScenes dataset, outperforming the previous best method by
a large margin. Our base model, VAD-Base, greatly reduces the average collision
rate by 29.0% and runs 2.5x faster. Besides, a lightweight variant, VAD-Tiny,
greatly improves the inference speed (up to 9.3x) while achieving comparable
planning performance. We believe the excellent performance and the high
efficiency of VAD are critical for the real-world deployment of an autonomous
driving system. Code and models will be released for facilitating future
research.Comment: Code&Demos: https://github.com/hustvl/VA
VMA: Divide-and-Conquer Vectorized Map Annotation System for Large-Scale Driving Scene
High-definition (HD) map serves as the essential infrastructure of autonomous
driving. In this work, we build up a systematic vectorized map annotation
framework (termed VMA) for efficiently generating HD map of large-scale driving
scene. We design a divide-and-conquer annotation scheme to solve the spatial
extensibility problem of HD map generation, and abstract map elements with a
variety of geometric patterns as unified point sequence representation, which
can be extended to most map elements in the driving scene. VMA is highly
efficient and extensible, requiring negligible human effort, and flexible in
terms of spatial scale and element type. We quantitatively and qualitatively
validate the annotation performance on real-world urban and highway scenes, as
well as NYC Planimetric Database. VMA can significantly improve map generation
efficiency and require little human effort. On average VMA takes 160min for
annotating a scene with a range of hundreds of meters, and reduces 52.3% of the
human cost, showing great application value
Electrical impedance performance of metal dry bioelectrode with different surface coatings
To improve the electrical impedance performance of bioelectrodes, a novel metal dry bioelectrodes with different coating layers are developed with laser micromilling and electroplating technology. Based on the analysis of the coating layer on the bioelectrode surface, the effect of different coating layers on the electrical impedance performance of bioelectrodes is investigated. The results show that the silver content increases with electroplating time when the silver layer is coated on the bioelectrode surface. However, the decrease of silver layer weight is observed with much longer electroplating time, and the optimal electroplating time is 20 min. Compared with the uncoated bioelectrode, the bioelectrode coated with silver layer exhibits much lower impedance value and better impedance stability. Especially, when the silver-coated bioelectrode is subsequently coated with silver-silver chloride layer, the lowest impedance value and best impedance stability are obtained
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