46 research outputs found
Simulation Modeling for Ship Traffic Flow in Entrance Channel
The design of coastal entrance channel is a complex challenge, considering the stochastic environment and time-consuming calculation works. Therefore, we implement a process-interaction-based simulation model for ship operation (PI-SMSO) using Java language to help the designers to determine the dimensions of entrance channels. The PI-SMSO component simulates ships in and out through a one- or two-way traffic channel, or a one-way channel with a ship-passing anchorage, and ships discharging/loading at berths. Finally, we apply the PI-SMSO to a Chinese coal-import terminal, to explore its possible bottlenecks by evaluating the performance of entrance channel system, and determine the available improvement strategies according to the simulated port performance. The case study proves that the proposed PI-SMSO effectively simulates the ship traffic flow in entrance channel and provides a decision support for evaluating entrance channel system
Edge Guided GANs with Multi-Scale Contrastive Learning for Semantic Image Synthesis
We propose a novel ECGAN for the challenging semantic image synthesis task.
Although considerable improvements have been achieved by the community in the
recent period, the quality of synthesized images is far from satisfactory due
to three largely unresolved challenges. 1) The semantic labels do not provide
detailed structural information, making it challenging to synthesize local
details and structures; 2) The widely adopted CNN operations such as
convolution, down-sampling, and normalization usually cause spatial resolution
loss and thus cannot fully preserve the original semantic information, leading
to semantically inconsistent results (e.g., missing small objects); 3) Existing
semantic image synthesis methods focus on modeling 'local' semantic information
from a single input semantic layout. However, they ignore 'global' semantic
information of multiple input semantic layouts, i.e., semantic cross-relations
between pixels across different input layouts. To tackle 1), we propose to use
the edge as an intermediate representation which is further adopted to guide
image generation via a proposed attention guided edge transfer module. To
tackle 2), we design an effective module to selectively highlight
class-dependent feature maps according to the original semantic layout to
preserve the semantic information. To tackle 3), inspired by current methods in
contrastive learning, we propose a novel contrastive learning method, which
aims to enforce pixel embeddings belonging to the same semantic class to
generate more similar image content than those from different classes. We
further propose a novel multi-scale contrastive learning method that aims to
push same-class features from different scales closer together being able to
capture more semantic relations by explicitly exploring the structures of
labeled pixels from multiple input semantic layouts from different scales.Comment: Accepted to TPAMI, an extended version of a paper published in
ICLR2023. arXiv admin note: substantial text overlap with arXiv:2003.1389
Field Longevity of a Fluorescent Protein Marker in an Engineered Strain of the Pink Bollworm, Pectinophora gossypiella (Saunders)
The cotton pest, pink bollworm (Pectinophora gossypiella (Saunders)), is a significant pest in most cotton-growing areas around the world. In southwestern USA and northern Mexico, pink bollworm is the target of the sterile insect technique (SIT), which relies on the mass-release of sterile pink bollworm adults to over-flood the wild population and thereby reduce it over time. Sterile moths reared for release are currently marked with a dye provided in their larval diet. There are concerns, however, that this marker fails from time to time, leading to sterile moths being misidentified in monitoring traps as wild moths. This can lead to expensive reactionary releases of sterile moths. We have developed a genetically marked strain that is engineered to express a fluorescent protein, DsRed2, which is easily screened under a specialised microscope. In order to test this marker under field conditions, we placed wild-type and genetically marked moths on traps and placed them in field cages. The moths were then screened, in a double-blind fashion, for DsRed2 fluorescence at regular intervals to determine marker reliability over time. The marker was shown to be robust in very high temperatures and generally proved reliable for a week or longer. More importantly, genotyping of moths on traps by PCR screening of the moths was 100% correct. Our findings indicate that this strain - and fluorescent protein markers in general - could make a valuable contribution to SIT
Auto-organisation de nanoparticules dans les films de tensioactifs déposés sur une surface solide
Notre approche expérimentale via la méthode de la bulle de surfactant a reposé sur l utilisation des propriétés d auto-assemblages de tensio-actifs, ces derniers stabilisant les parois des films minces et permettant ainsi l organisation des nano-objets. Le film est alors transféré sur des substrats solides et caractérisé par AFM, XPS et SEM. Deux types de nano-objets ont été étudiés : d une part, nous avons d'abord prouvé que le film de SWNT pouvait être transféré sur des substrats de mouillabilité variable. Sur surface hydrophobe, nous avons obtenu des films présentant une forte densité de SWNT alignés. Dans l optique d applications type électrodes transparentes, il est necessaire de transposer ces expériences à des substrats de nature différente tel que le verre ou le kapton et les premiers résultats obtenus sont encourageants avec des dépots de SWNT denses et homogènes. D autre part, nous avons étendu cette méthode de dépôt à deux types de nanoparticules hydrophiles : les nanofils d oxydes mixtes type CeVO4 et les nanoparticules de silice. Dans le cas des nanofils, nous avons mis en évidence l influence du temps de drainage au sein de la bulle sur la densité de nano-objets présents dans le film une fois déposé. Dans le cas des nanoparticules de silice, c est, cette fois-ci, la concentration en surfactant qui va être un facteur déterminant pour la morphologie finale du film. Ces travaux ont donc permis de montrer que notre technique de confinement et de dépôt de nano-objets via des bulles de surfactants était une méthode simple, facile à mettre en place et généralisable à une grande variété de nano-objets et de substrats.Our experimental approach via the surfactant bubble method has consisted in the use of the surfactant self-assembly properties. In the bubble, the surfactants stabilize the thin film walls and lead to the nano-objets organization. The film is then transferred on solid substrates and characterized by AFM, XPS and SEM. Two kinds of nano-objets have been studied: On the one hand, we first proved that the SWNT film could be transferred on substrates with different wettabilities. On hydrophobic substrates, we obtained films with a high density of aligned SWNTs. For applications like transparent electrodes, it s necessary to transpose these experiments on other substrates like glass or Kapton film. Preliminary results are positive with dense and homogeneous SWNT films. On the other hand, we have extended this deposition method to hydrophilic nanoparticles like CeVO4 nanowires and silica nanoparticles. In nanowire case, we have a correlation between the drainage time inside the bubble and the density of nano-objets in the deposited film. In silica nanoparticle case, the surfactant concentration is one of the main factors which determine the final film morphology. These works have showed that our nano-objet confinement and deposition technique using the bubble deposition method is really easy to put in place and can be extended to a large variety of nano-objets and substrates.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF
Performance Comparison of Real-Time Yard Crane Dispatching Strategies at Nontransshipment Container Terminals
Yard crane operations are often a bottleneck at a container terminal. This paper aims to investigate the effects of various real-time yard crane dispatching strategies on operational cost and gross crane rate (GCR) for nontransshipment container terminals. A general cost estimation model is introduced to incorporate the detailed costs incurred during container handling process within terminal area. The formulas of container handling related parameters are mathematically derived to validate the simulation model. Results reveal that the common nearest truck first served strategy yields the lowest operational cost but the lowest GCR. On the other hand, earliest YT strategy achieves the highest GCR at the expense of higher operational cost with more vessel calls, while nearest YT strategy produces the highest GCR and is the second economical with fewer vessel calls. Under any of the proposed yard crane dispatching strategies, the strategy that separately stacks import and export containers into different blocks outperforms the scattered stacking strategy in terms of GCR, although no distinct cost advantage is obtained. The results provide fundamental insights into the connection between real-time yard crane dispatching strategies and operational performance at manually controlled nontransshipment container terminals
Transient Sloshing in Partially Filled Laterally Excited Horizontal Elliptical Vessels With T-Shaped Baffles
Performance Comparison of Real-Time Yard Crane Dispatching Strategies at Nontransshipment Container Terminals
New Confinement Method for the Formation of Highly Aligned and Densely Packed Single-Walled Carbon Nanotube Monolayers
A new method to obtain single-walled nanotube (SWNT) films with high density and orientation (see image) is described. It is based on confinement of self-organized nano-objects within surfactant bilayers. This generic method is compatible with a wide array of nano-objects (SWNTs, nanowires, nanoparticles, etc.) as well as with most substrates, such as transparent and flexible organic substrates that are of great interest in electronics applications
A 400 nW single-inductor dual-input–tri-output DC–DC buck–boost converter with maximum power point tracking for indoor photovoltaic energy harvesting
This paper presents a single-inductor dual-input- tri-output buck-boost (DITOBB) converter that manages energy harvesting, energy storage, and power rail regulation of an indoor remote sensor system. The converter operates in discontinuous conduction mode (DCM) and regulates the outputs with a combination of pulse-skipping modulation (PSM) and constant-ON-time pulse-frequency modulation (PFM). To reduce the quiescent power, all the circuit blocks are turned OFF when the outputs are within regulation, except a system clock generator. A newly designed relaxation oscillator provides the main clock of the system, which requires neither reference voltages nor comparators. The frequency of the system clock doubles or halves based on the states of the sources and outputs following a proposed algorithm. The DITOBB converter has been designed and fabricated using 0.18 ÎĽm CMOS process. With a quiescent power of 400 nW, the designed DITOBB converter shows a measured peak efficiency of 83% at 100 ÎĽW output power