Vehicle Routing Problem with Time Windows and Simultaneous Delivery and Pick-Up Service Based on MCPSO

This paper considers two additional factors of the widely researched vehicle routing problem with time windows (VRPTW). The two factors, which are very common characteristics in realworld, are uncertain number of vehicles and simultaneous delivery and pick-up service. Using minimization of the total transport costs as the objective of the extension VRPTW, a mathematic model is constructed. To solve the problem, an efficient multiswarm cooperative particle swarm optimization (MCPSO) algorithm is applied. And a new encoding method is proposed for the extension VRPTW. Finally, comparing with genetic algorithm (GA) and particle swarm optimization (PSO) algorithm, the MCPSO algorithm performs best for solving this problem

Downstream Placement of FANS to Determine Fan Performance in Situ

Accurate ventilation rate data are essential to maximizing the quality of aerial emission measurements. The fan assessment numeration system (FANS) devices have been widely used by U.S. researchers in measuring aerial emissions from mechanically ventilated livestock and poultry confinement. It is used to conduct in-situ calibration of building ventilation fans and thus development of the fan performance curve under the field operation conditions. The FANS device was originally intended to be placed in the upstream of the fan under in-situ calibration. However, certain field situations make it impractical to apply the FANS device as such. This study assessed the possible use of the FANS in the downstream of a ventilation fan, with the gaps between the FANS device and the discharge cone of the exhaust fan sealed by non-permeable fabric. Nine exhaust fans (1.22 - 1.32 m diameter) in laying-hen and turkey houses were tested with the FANS placed in upstream or downstream for a building static pressure range of 10 to 40 Pa. The results revealed that downstream placement of FANS device yielded 0.44 to 3.1% higher ventilation rate when compared to its upstream placement. This discrepancy is considered acceptable for in-situ fan calibration

Particulate Matter Emissions from a High-rise Layer House in Iowa

Particulate matter (PM) in animal feeding operations is a concern for the occupants and the surrounding community. Baseline measurements of the concentration and emission rate of PM are the first step toward assessing the environmental impact of animal feeding operation and evaluating the effectiveness of dust control strategies. This study presents the results of the PM measurement at a high-rise layer house in central Iowa. The average PM10 emission rate over the 9- month measurement period was 21.6 (±10 S.D.) mg/bird/day. Comparing with the emission rates reported literature, the mean and range of PM10 emission from high-rise layer hen barns using cage systems were 33.5 and 19-48 mg/bird/day. The average PM2.5 emission rate over the measurement period was 2 (± 1.5 S.D.) mg/bird/day, which is less than literature values of 3.52-14.2 mg/bird/day

Technical Note: Upstream vs. Downstream Placement of FANS Device to Determine Ventilation Fan Performance in Situ

Accurate ventilation rate (VR) data are essential to maximizing the quality of aerial emission measurements. The Fan Assessment Numeration System (FANS) has been widely used by U.S. researchers in measuring aerial emissions from mechanically ventilated livestock and poultry facilities. The FANS device is used to measure airflow rates of ventilation fans in situ, thereby developing fan performance curves under field conditions. The FANS device was originally intended to be placed upstream of the fan to be calibrated. However, certain field situations make it impractical to apply the FANS device as such. This study was conducted to assess use of the FANS device downstream of a ventilation fan, with the gaps between the FANS device and the discharge cone of the exhaust fan sealed using a non-permeable fabric. Nine exhaust fans (1.22 or 1.32 m diameter) in laying hen and turkey houses were tested with the FANS device placed upstream and downstream for a building static pressure range of 10 to 40 Pa. The results revealed that downstream placement of the FANS device yielded 0.6% ±0.4% to 4.0% ±0.9 % (mean ±SE) higher but not significantly different (P \u3e 0.28) VR values as compared to upstream placement for the exhaust fans tested. This magnitude of discrepancy is considered acceptable for in situ measurement of fan performance

Internal Wasserstein Distance for Adversarial Attack and Defense

Deep neural networks (DNNs) are vulnerable to adversarial examples that can trigger misclassification of DNNs but may be imperceptible to human perception. Adversarial attack has been an important way to evaluate the robustness of DNNs. Existing attack methods on the construction of adversarial examples use such $\ell_p$ distance as a similarity metric to perturb samples. However, this kind of metric is incompatible with the underlying real-world image formation and human visual perception. In this paper, we first propose an internal Wasserstein distance (IWD) to measure image similarity between a sample and its adversarial example. We apply IWD to perform adversarial attack and defense. Specifically, we develop a novel attack method by capturing the distribution of patches in original samples. In this case, our approach is able to generate semantically similar but diverse adversarial examples that are more difficult to defend by existing defense methods. Relying on IWD, we also build a new defense method that seeks to learn robust models to defend against unseen adversarial examples. We provide both thorough theoretical and empirical evidence to support our methods

Experimental study on mechanical and acoustic emission characteristics of sedimentary sandstone under different loading rates

In the field of rock engineering, complexity of stress environment is an important factor affecting its stability. Thus, in view of fracture mechanism of rock under different loading rates within the scope of quasi-static strain rate, four groups of uniaxial compression tests with different strain rates were carried out on sandstone specimens, and strength, deformation, failure modes and acoustic emission characteristics of specimens were compared and analyzed. Furthermore, the fracture mechanism was discussed from the perspective of fracture characteristics based on fractal dimension, crack propagation law inverted through acoustic emission b-value, and micro fracture morphology. The results showed that as the strain rate increased from 10 to 5 s−1 to 10−2 s−1, the fractal dimension of rock fragments increased, and the fractal dimension of rock fragments increased by 9.66%, 7.32%, and 3.77% successively for every 10 times increase in strain rate, which means that the equivalent size of fragments was getting smaller, and the fragmentation feature was becoming increasingly prominent. The crack propagation process based on acoustic emission b-value showed that with the increase of loading rate, the specimen entered the rapid crack propagation stage earlier, in order of 68%, 66%, 29%, and 22% of peak stress. Moreover, the microscopic fracture morphology showed that with the increase of loading rate, transgranular phenomenon was clear, and the fracture morphology changed from smooth to rough. That meant that the fracture of sandstone rock at high loading rates was mainly caused by the propagation of large cracks, which was different from the slow process of initiation, convergence and re-propagation of small cracks at low strain rates

Uranium and molybdenum isotope evidence for an episode of widespread ocean oxygenation during the late Ediacaran Period

The final publication is available at Elsevier via https://doi.org/10.1016/j.gca.2015.02.025 © 2015. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/To improve estimates of the extent of ocean oxygenation during the late Ediacaran Period, we measured the U and Mo isotope compositions of euxinic (anoxic and sulfidic) organic-rich mudrocks (ORM) of Member IV, upper Doushantuo Formation, South China. The average d238U of most samples is 0.24 ± 0.16& (2SD; relative to standard CRM145), which is slightly higher than the average d238U of 0.02 ± 0.12& for restricted Black Sea (deep-water Unit I) euxinic sediments and is similar to a modeled d238U value of 0.2& for open ocean euxinic sediments in the modern well-oxygenated oceans. Because 238U is preferentially removed to euxinic sediments compared to 235U, expanded ocean anoxia will deplete seawater of 238U relative to 235U, ultimately leading to deposition of ORM with low d238U. Hence, the high d238U of Member IV ORM points to a common occurrence of extensive ocean oxygenation ca. 560 to 551 Myr ago. The Mo isotope composition of sediments deposited from strongly euxinic bottom waters ([H2S]aq >11 lM) either directly records the global seawater Mo isotope composition (if Mo removal from deep waters is quantitative) or represents a minimum value for seawater (if Mo removal is not quantitative). Near the top of Member IV, d98Mo approaches the modern seawater value of 2.34 ± 0.10&. High d98Mo points to widespread ocean oxygenation because the preferential removal of isotopically light Mo to sediments occurs to a greater extent in O2-rich compared to O2-deficient marine environments. However, the d98Mo value for most Member IV ORM is near 0&(relative to standard NIST SRM 3134 = 0.25&), suggesting extensive anoxia. The low d98Mo is at odds with the high Mo concentrations of Member IV ORM, which suggest a large seawater Mo inventory in well-oxygenated oceans, and the high d238U. Hence, we propose that the low d98Mo of most Member IV ORM was fractionated from contemporaneous seawater. Possible mechanisms driving this isotope fractionation include: (1) inadequate dissolved sulfide for quantitative thiomolybdate formation and capture of a seawater-like d98Mo signature in sediments or (2) delivery of isotopically light Mo to sediments via a particulate Fe–Mn oxyhydroxide shuttle. A compilation of Mo isotope data from euxinic ORM suggests that there were transient episodes of extensive ocean oxygenation that break up intervals of less oxygenated oceans during late Neoproterozoic and early Paleozoic time. Hence, Member IV does not capture irreversible deep ocean oxygenation. Instead, complex ocean redox variations likely marked the transition from O2-deficient Proterozoic oceans to widely oxygenated later Phanerozoic oceans.National Science Foundation NASA Astrobiology Institute Agouron Institute Natural Sciences and Engineering Research Council of Canada Discovery Gran