346 research outputs found
Performance Evaluation of Coordinated Intersections with GPS Devices
This paper presents methods for applying GPS devices to evaluate the performance of coordinated intersections in terms of traffic delays. It illustrates that GPS-recorded data provides detailed information on traffic delays of individual intersections as well as traffic delays of coordinated intersections as a whole system, including travel-time delay, stopped-time delay, time-in-queue delay, approach delay, and total delay. Most of these intersection delays are difficult to measure manually; however, with GPS-collected vehicle-positioning data, they can be either directly identified or indirectly derived. Methods for obtaining different types of intersection delays with GPS devices are introduced
FocusFlow: Boosting Key-Points Optical Flow Estimation for Autonomous Driving
Key-point-based scene understanding is fundamental for autonomous driving
applications. At the same time, optical flow plays an important role in many
vision tasks. However, due to the implicit bias of equal attention on all
points, classic data-driven optical flow estimation methods yield less
satisfactory performance on key points, limiting their implementations in
key-point-critical safety-relevant scenarios. To address these issues, we
introduce a points-based modeling method that requires the model to learn
key-point-related priors explicitly. Based on the modeling method, we present
FocusFlow, a framework consisting of 1) a mix loss function combined with a
classic photometric loss function and our proposed Conditional Point Control
Loss (CPCL) function for diverse point-wise supervision; 2) a conditioned
controlling model which substitutes the conventional feature encoder by our
proposed Condition Control Encoder (CCE). CCE incorporates a Frame Feature
Encoder (FFE) that extracts features from frames, a Condition Feature Encoder
(CFE) that learns to control the feature extraction behavior of FFE from input
masks containing information of key points, and fusion modules that transfer
the controlling information between FFE and CFE. Our FocusFlow framework shows
outstanding performance with up to +44.5% precision improvement on various key
points such as ORB, SIFT, and even learning-based SiLK, along with exceptional
scalability for most existing data-driven optical flow methods like PWC-Net,
RAFT, and FlowFormer. Notably, FocusFlow yields competitive or superior
performances rivaling the original models on the whole frame. The source code
will be available at https://github.com/ZhonghuaYi/FocusFlow_official.Comment: The source code of FocusFlow will be available at
https://github.com/ZhonghuaYi/FocusFlow_officia
Sustainable protected cropping : a case study of seasonal impacts on greenhouse energy consumption during capsicum production
Sustainable food production in protected cropping is increasing rapidly in response to global climate change and population growth. However, there are significant knowledge gaps regarding energy consumption while achieving optimum environmental conditions for greenhouse crop production. A capsicum crop cultivated in a high-tech greenhouse facility in Australia was analysed in terms of relationships between key environmental variables and the comparative analysis of energy consumption during different seasons. We showed that daily energy consumption varied due to the seasonal nature of the external environment and maintenance of optimal growing temperatures. Total power consumption reported throughout the entire crop cycle for heating (gas hot water system) and cooling (pad and fan) was 12,503 and 5183 kWh, respectively; hence, heating consumed ca. 70% of the total energy requirement over the 8-month growing period (early spring to late autumn) in the greenhouse facility. Regressions of daily energy consumption within each season, designated either predominantly for heating or cooling, indicated that energy consumption was 14.62 kWh per 1 °C heating and 2.23 kWh per 1 °C cooling. Therefore, changing the planting date to late spring is likely to significantly reduce heating energy costs for greenhouse capsicum growers in Australia. The findings will provide useful guidelines to maximise the greenhouse production of capsicum with better economic return by taking into consideration the potential optimal energy saving strategy during different external environment conditions and seasons
Minimalist and High-Quality Panoramic Imaging with PSF-aware Transformers
High-quality panoramic images with a Field of View (FoV) of 360-degree are
essential for contemporary panoramic computer vision tasks. However,
conventional imaging systems come with sophisticated lens designs and heavy
optical components. This disqualifies their usage in many mobile and wearable
applications where thin and portable, minimalist imaging systems are desired.
In this paper, we propose a Panoramic Computational Imaging Engine (PCIE) to
address minimalist and high-quality panoramic imaging. With less than three
spherical lenses, a Minimalist Panoramic Imaging Prototype (MPIP) is
constructed based on the design of the Panoramic Annular Lens (PAL), but with
low-quality imaging results due to aberrations and small image plane size. We
propose two pipelines, i.e. Aberration Correction (AC) and Super-Resolution and
Aberration Correction (SR&AC), to solve the image quality problems of MPIP,
with imaging sensors of small and large pixel size, respectively. To provide a
universal network for the two pipelines, we leverage the information from the
Point Spread Function (PSF) of the optical system and design a PSF-aware
Aberration-image Recovery Transformer (PART), in which the self-attention
calculation and feature extraction are guided via PSF-aware mechanisms. We
train PART on synthetic image pairs from simulation and put forward the PALHQ
dataset to fill the gap of real-world high-quality PAL images for low-level
vision. A comprehensive variety of experiments on synthetic and real-world
benchmarks demonstrates the impressive imaging results of PCIE and the
effectiveness of plug-and-play PSF-aware mechanisms. We further deliver
heuristic experimental findings for minimalist and high-quality panoramic
imaging. Our dataset and code will be available at
https://github.com/zju-jiangqi/PCIE-PART.Comment: The dataset and code will be available at
https://github.com/zju-jiangqi/PCIE-PAR
Variation of the Jovian Magnetopause Under Constant Solar Wind Conditions: Significance of Magnetodisc Dynamics
It is generally believed that variations in the upstream solar wind (SW) and interplanetary magnetic field (IMF) conditions are the main cause of changes of Jupiter's magnetopause (JM) location. However, most previous pressure balance models for the JM are axisymmetric and do not consider internal drivers, for example, the dynamics of the magnetodisc. We use three-dimensional global magnetosphere simulations to investigate the variation of the JM under constant SW/IMF conditions. These simulations show that even without variations in the upstream driving conditions, the JM can exhibit dynamic variations, suggesting a range as large as 50 Jupiter radii in the subsolar location. Our study shows that the interchange structures in the Jovian magnetodisc will introduce significant radial dynamic pressure, which can drive significant variation in the JM location. The results provide important new context for interpreting the JM location and dynamics, with key implications for other internally mass-loaded and/or rapidly rotating systems
Query-document-dependent fusion: A case study of multimodal music retrieval
National Research Foundation (NRF) Singapore under International Research Centre @ Singapore Funding Initiativ
Clinical application of three-dimensional printed models in preoperative planning of pancoast tumour resection
BackgroundThe resection of pancoast tumours is a highly challenging procedure for cardiothoracic surgeons. A patient-specific 3D printed model of the tumour may be useful as an adjunct to standard preoperative planning procedures.AimsThis study aims to assess the clinical value of a 3D printed pancoast tumour model as a preoperative planning tool.MethodsTwo anonymised cases of pancoast tumours were obtained and one was chosen to be 3D printed. The model was presented to two cardiothoracic surgeons with more than 10 years of experience. Interview and questionnaire sessions were conducted to sought expert opinions about the clinical value of the model as a preoperative planning tool. ResultsThe participants agreed that the 3D printed model provides an accurate representation of the exact location of the tumour in relation to surrounding structures. The hand-held model also offers a tactile approach to preoperative planning, facilitating the planning of ports placement. The model is also potentially useful in team communication and patient education, leading to improved surgical outcomes. ConclusionThis study has demonstrated the clinical value of a patient-specific 3D printed model of pancoast tumour in preoperative planning. Apart from enhancing the surgeons’ understanding of the anatomical location of the tumour, the model is also easily manipulated. Future research could investigate the impact of 3D printed model on short to mid-term clinical outcomes
Quantitative characterization of the focusing process and dynamic behavior of differently sized microparticles in a spiral microchannel
Abstract In this paper, a spiral microchannel was fabricated to systematically investigate particle dynamics. The focusing process or migration behavior of different-sized particles in the outlet region was presented. Specifically, for focused microparticles, quantitative characterization and analysis of how particles migrate towards the equilibrium positions with the increase in flow rate (De = 0.31-3.36) were performed. For unfocused microparticles, the particle migration behavior and the particlefree region's formation process were characterized over a wide range of flow rates (De = 0.31-4.58), and the emergence of double particle-free regions was observed at De C 3.36. These results provide insights into the design and operation of high-throughput particle/cell filtration and separation. Furthermore, using the location markers prefabricated along with the microchannel structures, the focusing or migration dynamics of different-sized particles along the spiral microchannel was systematically explored. The particle migration length effects on focusing degree and particle-free region width were analyzed. These analyses may be valuable for the optimization of microchannel structures. In addition, this device was successfully used to efficiently filter rare particles from a large-volume sample and separate particles of two different sizes according to their focusing states
Energy minimisation in a protected cropping facility using multi-temperature acquisition points and control of ventilation settings
Energy management in protected cropping is critical due to the high cost of energy use in high-tech greenhouse facilities. The main purpose of this research was to investigate the optimal strategy to reduce cooling energy consumption, by regulating the settings (opening/closing) of either vents or curtains during the day, at the protected cropping facility at Western Sydney University. We measured daily changes in air temperature and energy consumption under four treatments (open/closed combinations of vents and shade screens) and developed an optimal cooling strategy for energy management using multi-temperature acquisition points at different heights within a greenhouse compartment. The optimal treatment (vents open/curtains closed) reduced energy load at the rooftop, thereby maintaining a desirable plant canopy temperature profile, and reducing cooling energy. Daily energy consumption was lowest for vents open/curtains closed (70.5 kWh) and highest for vents closed/curtains open (121 kWh). It was also found that delaying the operation of opening and closing of vents and curtains until the plant canopy temperature reached 25 ◦C reduced
cooling energy consumption and decreased heating energy consumption in the morning (e.g., 08:00 to 10:00). The estimated savings of 1.83 kWh per 1 ◦C cooling between the optimal (vents open/curtains closed) and least optimal (vents closed/curtains open) conditions had the potential for significant
energy savings at 494 kWh per ◦C over a crop cycle of nine months in warm weather conditions. However, selection of the optimal cooling strategy utilising control of vents and curtains must also account for the impact from other greenhouse environmental factors, including light, humidity, and CO2 concentration, which may be crop specific
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