Large Capture Research Articles

Fast medium-scale multiperson identification in aerial videos

Vision systems for unmanned aerial vehicles (UAVs) have been gaining increasing attention for surveillance and civil applications. However, aerial platforms create new challenges for several vision tasks (e.g., human tracking and identification) because UAV-mounted cameras undergo large vibration movements and capture unstable videos. Furthermore, most existing machine vision approaches use the fine details of a human figure, which are unavailable in low-quality aerial images. We propose a new blob-matching approach for human identification in aerial videos in which the identity of a human blob is estimated using an adaptive reference set of previously identified people. A target can be quickly located by matching only the target and a carefully selected candidate set. The experimental results obtained using several challenging aerial videos validated the effectiveness and computational efficiency of the proposed method.

A New Active Contour Model Based on Distance-Weighted Potential Field

Snakes, or active contours, have been widely used in various image processing applications. Typical problems of snakes, including limited capture range, poor convergence to concavities, noise sensitivity, and initialization sensitivity, have limited their applications. For solving these problems, we propose a new potential for the active contour model. In this proposed potential field, each location's potential is computed by integrating the feature information from all the pixels in the image with the distances as the weights. The external forces are computed as the gradients of this proposed potential field, and the computed external forces are static and have global capture range. Experiments and also the comparisons with the snake using gradient vector flow (GVF) as external forces are conducted to examine the performances of this proposed snake. The results show that the proposed snake has a large capture range and an excellent convergence to boundary concavities, and also the proposed snake is more robust to noise, more time efficient, and less sensitive to the initialization, compared with the GVF snake.

Ocorrência e sazonalidade de Somotricus unifasciatus (Dejean, 1831), associado à criação de Gallus gallus domesticus

The present study reports the occurrence and population fluctuation of Somotricus unifasciatus (Coleoptera: Carabidae), an exotic predatory species. The insects were collected once per week for 12 months, using traps, at the aviary of the Conjunto Agrotecnico Visconde da Graca (CAVG), in Pelotas, Rio Grande do Sul, Brazil. During the study, 1158 specimens of S. unifasciatus were captured. The highest occurrence period was in February (472), when the monthly average temperature was 24.7oC, while the lowest occurrence periods were in July (01), April (0) and June (0). The population density of the coleopteron varied throughout the year, with the largest capture averages obtained during months with higher average temperatures (December, January, February and March).

Evaluation of Seasonal and Large Storm Runoff Volume Capture of an Infiltration Green Infrastructure System

Green infrastructure, including stormwater control measures (SCMs), meant to reduce runoff volumes are typically designed for smaller, frequently occurring events (e.g., 2.5 cm or the 2-year, 24 h event), and their performance are not always considered for larger, more infrequent extreme event management. However, even during larger rainfall events, a SCM is still capturing at least the design rainfall and reducing runoff volume. Further, if a SCM relies on infiltration as its primary volume reduction strategy, infiltration continues throughout the rainfall event indicating that SCMs can be considered in flood mitigation strategies. This phenomenon of greater than designed runoff volume removal has been noted in several infiltrating SCMs, and the present work uses the Villanova green infrastructure site comprising an infiltration trench with pretreatment (i.e., linear vegetated SCMs) designed for the 2.5 cm rainfall event as a basis for discussion. The analysis focuses on the infiltration trench volume capture and includes the effect of storm volume, duration, intensity, and antecedent dry time. Seasonally, infiltration rates within the infiltration trench were shown to vary with temperature in the lower ponding depths. While there was some decrease in infiltration rates in the lowest depth increment (0–0.3 m) in the systems’ third winter and spring seasons, there was a general increase in infiltration rates over the course of the study period demonstrating the infiltrating SCMs’ ability to be a reliable stormwater management solution. With regards to large storm event performance, the results from 2 years of monitoring the infiltration SCM system have been quite impressive. The system has consistently met the volume reduction design goals and usually exceeded them by significantly contributing to storm runoff mitigation during large extreme events. The infiltration SCM system captured and removed at least 59% of the volume of every storm event analyzed from July 2012 through June 2014, with an average of 93% capture for events greater than the design volume of 2.5 cm. Furthermore, there were 159 storm events totaling 259 cm of rainfall during the study period. Given the drainage area loading, approximately 2,365 m3 of rainfall entered the linear vegetated component, with approximately 420 m3 (18%) reaching the infiltration trench and only 103 m3 (4%) of rainfall determined to overflow from the system. These performance results demonstrate that infiltration SCMs can reduce significant volumes of runoff during larger events and that new design strategies are needed to account for their performance.

Spectral characteristics of carrier transfer from Si cluster to nanocrystal in Si-rich-oxide/SiO2 multilayer films

Si-rich-oxide/SiO2 multilayer composite films containing Si clusters and nanocrystals (NCs) have been synthesized by PECVD technique, and the carrier transfer processes from Si cluster to nanocrystal are studied by photoluminescence (PL) spectra. Compared with the references, intense PL is observed in the composite film, which is caused by the combined effect of Si clusters and NCs. Optical excitation is enhanced due to the dense Si clusters, while the carriers generated in the clusters are transferred to the Si–NCs due to their large carrier capture section. The PL excitation spectra shows that the resonance excitation energy is 3.58 eV, which corresponds to the excitation energy level of SiOX shell covering the Si clusters. Double stretched-exponential decay model is used to demonstrate the PL decay processes in the composite film, and the results suggest that the carrier transfer time is about 35.8 μs.

Techno-economic performance and spatial footprint of infrastructure configurations for large scale CO2 capture in industrial zones: A case study for the Rotterdam Botlek area (part A)

This study developed a method to assess the techno-economic performance and spatial footprint of CO2 capture infrastructure configurations in industrial zones. The method has been successfully applied to a cluster of sixteen industrial plants in the Dutch industrial Botlek area (7.1MtCO2/y) for 2020–2030. The configurations differ inter alia regarding capture technology (post-, pre-, oxyfuel combustion) and location of capture components (centralized vs. plant site). Results indicate that oxyfuel combustion with centralized oxygen production and decentralized CO2 compression is the most cost effective and realistic configuration when applying CO2 capture to all industrial plants (61€/tCO2; 5.8MtCO2/y avoided), mainly due to relatively low energy costs compared to post- and pre-combustion. However, oxyfuel combustion at plant level is economically preferable when capturing CO2 from only the three largest industrial plants. For post-combustion, a separated absorber-stripper configuration (73€/tCO2; 7.1MtCO2/y avoided) is preferable from a cost perspective, due to economic scale effects of capture equipment. The optimal pre-combustion configuration shows a slightly less favorable performance (81€/tCO2; 4.4MtCO2/y avoided). Whereas many industrial plants have insufficient space available for capture equipment, centralized/hybrid configurations show no insurmountable space issues. The deployment of the most favorable configurations is addressed in Part B.

United-proportional-navigation law for interception of high-speed maneuvering targets

Aimed to high-speed maneuvering targets,three dimensional united proportional navigation( UPN) law was proposed. The guidance law combines the advantages of head-on and head-pursuit engagement through time-varying navigation ratio. The three-dimensional UPN law consisted of two planar laws can execute head-on with head-on,head-pursuit with head-pursuit and head-on with head-pursuit mixed models,which enlarge the capture region of interceptor tremendously. At planar engagement geometry,the analytic expression of line of sight( LOS) angular rate was deduced according to the target acceleration,and the timevariant navigation ratio was designed. While the planar UPN guidance law was extended into a three dimensional condition,the mistake of interceptor path angle and velocity at pitch plane in prior algorithm was modified and the target evading model was given. The simulation results show that,for high speed maneuvering targets,UPN has less miss distance than proportional navigation( PN) and retro proportional navigation( RPN),less control effort than augmented proportional navigation( APN) and larger capture region than the others.

Recent advances and current issues in single-cell sequencing of tumors

Intratumoral heterogeneity is a recently recognized but important feature of cancer that underlies the various biocharacteristics of cancer tissues. The advent of next-generation sequencing technologies has facilitated large scale capture of genomic data, while the recent development of single-cell sequencing has allowed for more in-depth studies into the complex molecular mechanisms of intratumoral heterogeneity. In this review, the recent advances and current challenges in single-cell sequencing methodologies are discussed, highlighting the potential power of these data to provide insights into oncological processes, from tumorigenesis through progression to metastasis and therapy resistance.

Distribution and Current Status of the Reptiles of Khirthar Protected Area Complex (KPAC) and Adjoining Areas in Districts Karachi, Jamshoro and Thatta, Sindh, Pakistan

In this study, surveys were undertaken during 2008 – 2013, to record the distribution and status of reptiles of the area, during the study 41 species of reptiles were recorded. Twenty two important habitats for reptiles in the area were identified and listed. Indian Spiny-tailed Lizard (Saara hardwickii) was found to be under threat in its localized habitat in Jhimpir Wind Corridor block in Thatta district and Indian Fat–tail Gecko (Eublepharis macularius) was noted to have been almost disappeared from most of the area due to large scale capture of the species for sale in the local markets.

The feasibility of in vivo quantification of bone-gadolinium in humans by prompt gamma neutron activation analysis (PGNAA) following gadolinium-based contrast-enhanced MRI

Abstract The feasibility of using a 238Pu/Be-based in vivo prompt γ-ray neutron activation analysis (IVNAA) system, previously successfully used for measurements of muscle, for the detection of gadolinium (Gd) in bone was presented. Gd is extensively used in contrast agents in MR imaging. We present phantom measurement data for the measurement of Gd in the tibia. Gd has seven naturally occurring isotopes, of which two have extremely large neutron capture cross sections; 155Gd (14.8% natural abundance (NA), σ= 60,900 barns) and 157Gd (15.65% NA, σ= 254,000 barns). Our previous work focused on muscle but this only informs about the short term kinetics of Gd. We studied the possibility of measuring bone, as it may be a long term storage site for Gd. A human simulating bone phantom set was developed. The phantoms were doped with seven concentrations of Gd of concentrations 0.0, 25, 50, 75, 100, 120 and 150 ppm. Additional elements important for neutron activation analysis, Na, Cl and Ca, were also included to create an overall elemental composition consistent with Reference Man. The overall conclusion is that the potential application of this Pu–Be-based prompt in vivo NAA for the monitoring of the storage and retention of Gd in bone is not feasible.

Patient Registration Using Intraoperative Stereovision in Image-guided Open Spinal Surgery.

Despite its widespread availability and success in open cranial neurosurgery, image-guidance technology remains more limited in use in open spinal procedures, in large part, because of patient registration challenges. In this study, we evaluated the feasibility of using intraoperative stereovision (iSV) for accurate, efficient, and robust patient registration in an open spinal fusion surgery. Geometrical surfaces of exposed vertebrae were first reconstructed from iSV. A classical multistart registration was then executed between point clouds generated from iSV and preoperative computed tomography images of the spine. With two pairs of feature points manually identified to facilitate the registration, an average registration accuracy of 1.43 mm in terms of surface-to-surface distance error was achieved in eight patient cases using a single iSV image pair sampling 2-3 vertebral segments. The iSV registration error was consistently smaller than the conventional landmark approach for every case (average of 2.02 mm with the same error metric). The large capture ranges (average of 23.8 mm in translation and 46.0° in rotation) found in the iSV patient registration suggest the technique may offer sufficient robustness for practical application in the operating room. Although some manual effort was still necessary, the manually-derived inputs for iSV registration only needed to be approximate as opposed to be precise and accurate for the manual efforts required in landmark registration. The total computational cost of the iSV registration was 1.5 min on average, significantly less than the typical ∼30 min required for the landmark approach. These findings support the clinical feasibility of iSV to offer accurate, efficient, and robust patient registration in open spinal surgery, and therefore, its potential to further increase the adoption of image guidance in this surgical specialty.

Hexagonal boron nitride thin film thermal neutron detectors with high energy resolution of the reaction products

Hexagonal boron nitride (h-BN) is highly promising for solid-state thermal neutron detector applications due to its many outstanding physical properties, especially its very large thermal neutron capture cross-section (~3840 barns for 10B), which is several orders of magnitude larger than those of most other isotopes. The focus of the present work is to carry out studies on h-BN thin film and detector properties to lay the foundation for the development of a direct-conversion solid-state thermal neutron detector with high sensitivity. The measured carrier mobility-lifetime (μτ) product of h-BN thin films grown on sapphire substrates is 2.83×10−7cm2/V for electrons and holes, which is comparable to the value of about 10−7cm2/V for GaN thin films grown on sapphire. Detectors based on h-BN thin films were fabricated and the nuclear reaction product pulse height spectra were measured. Under a bias of 20V, very narrow individual peaks corresponding to the reaction product energies of α and Li particles as well as the sum peaks have been clearly resolved in the pulse height spectrum for the first time by a B-based direct-conversion semiconductor neutron detector. Our results indicate that h-BN thin film detectors possess unique advantages including small size, low weight, portability, low voltage operation and high energy resolution of specific reaction products.

The oceanographic toolbox for the collection of sinking and suspended marine particles

Marine particles play a central role in controlling the transport, cycling, and inventories of many major elements and trace elements and isotopes throughout the oceans. Studies seeking to elucidate the biogeochemical roles of marine particles often require reliable ways to collect them from the ocean. Here, we review the oceanographic toolbox of techniques and instrumentation that are employed to collect both suspended and sinking particles. With these tools, it is possible to determine both the concentrations and vertical fluxes of important elements and individual particle types. We describe the various methods for quantifying the concentrations of particulate matter with in situ pumps, towed sampling devices, bottle collectors, and large volume capture devices. The uses of various types of flux collection platforms are discussed including surface tethered, neutrally buoyant, and bottom moored devices. We address the issues of sediment trap collection biases and the apparent inconsistencies that can arise due to differences in the temporal and spatial scales sampled by the various methodologies. Special attention is given to collection considerations made for the analysis of trace metals and isotopes, as these methodologies are of high importance to the ongoing GEOTRACES program which seeks to identify the processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean. With the emergence of new particle collection methodologies and the continued reliance on traditional collection methods, it is imperative that we combine these multiple approaches in ways that will help improve their accuracy and precision while enhancing their utility in advancing understanding of the biogeochemical and ecological roles of marine particles.

DRAGON用于嬗变MA的计算研究

长寿命高放废物MA作为核电站乏燃料中的重要组成部分，由于其特殊的物理化学性质，对生态有很强的危害性，一直是各国研究的重要课题之一。目前处理MA最安全有效的方法，是中子嬗变技术，而压水堆又是我国目前投入商业运行的主要的堆型，因此开展压水堆嬗变MA的研究在我国具有重要的意义。本文利用DRAGON程序建立了简化的AP1000燃料组件模型，模拟计算了在可燃毒物内均匀混合MA、在可燃毒物外镀层引入MA两种方式对燃料组件有效增殖因子(keff)、堆芯燃耗、燃料周期以及堆芯寿期的影响。结果表明：MA以上述两种方式添加到可燃毒物中后，燃料组件的燃耗深度会减少，从而延长了堆芯的燃料周期，同时也会对燃料组件的keff值产生影响，燃料组件维持在临界以上的时间也会延长，在一定程度上也会对整个堆芯的寿期产生有利影响。 The Minor Actinides (MA), a sort of long-lived and high-level radioactive nuclides is one of the most important part in the nuclear spent fuel. The MA is harmful to the ecological system because of its peculiar physical and chemical property. How to handle the MA in the spent fuel has always been one of the most important issues in nuclear waste management all over the world. The MA can be transmuted into stable or short-lived nuclides by neutron irradiation, and this is the most effective way to manage those high-level wastes. The PWR is the main reactor type at commercial operation in China, and the MA has a larger capture and fission cross section in the thermal reactor, therefore the study on the transmutation of the MA in the PWR has an important significance in China. This paper has used the DRAGON to build a simplified model of the AP1000 PWR fuel assembly and calculated the impacts on the k-effective of the fuel assembly, the fuel burnup, the fuel cycle and core lifetime when the MA uniformly mixed with the burnable poison or cladded on the burnable poison. The results show that: when the MA is added to the burnable poison in the above two methods, burnup level of the fuel assembly decreases and the fuel cycle of the core lengthens. It also has an impact on the k-effective of the fuel assembly, extending the time of the fuel assembly maintaining above the critical and has a favorable impact on core lifetime.

Simulation and measurement of stiffness for dual beam laser trap using residual gravity method

Dual-beam optical trap is constituted by two beams of unfocused counter-propagating laser. It has advantages such as several equilibrium points, small optical power density, large capture range and easier integration with other technologies, which optical tweezers may not achieve. Dual-beam optical trap stiffness is an important parameter to describe its mechanical properties. On the basis of quartz-substrate dual-beam optical fibre trap unit, we demonstrate a simple method for measuring stiffness. Residual gravity offset by buoyancy may provide a tiny force for the optical trap. By measuring the relations between the captured particle's axial equilibrium position and residual gravity, we may calibrate the optical trap stiffness. This method simply requires measuring the relative position of the particle in the steady state of the optical trap, and dynamic measurement of the particles location is not needed, so we can get a high position accuracy by long time measuring, thus the accuracy of the stiffness calibration is improved. In this paper, we simulated and carried out experiments to measure the stiffness of a dual-beam fibre optical trap unit based on a quartz-substrate. We simulate the stiffness of several Mie particles with different materials and sizes in dual-beam optical trap as well as the relation between the waist radius of fundamental mode Gaussian beam and stiffness. Stiffness measurement experiment is conducted using the residual gravity method. Stiffness values measured in experiments are consistent with the simulation results, which verify the validity and accuracy of the method.

입체 장애 알카놀아민 혼합 수용액에서 중탄산칼륨 결정의 냉각 반용매 결정화

absorption processes have a good potential for large scale capture of but a large amount of absorbing solution has to be regenerated, undesirably increasing the consumption of energy such as sensible heat and latent heat of vaporization. In this study, a cooling crystallization process which would separate the -rich potassium bicarbonate crystals from -lean water was developed to reduce the energy penalty. Sterically hindered alkanolamine additives were used to enhance the removal efficiency and their antisolvent effect on the crystallization was found in a continuous cooling crystallizer. The production yields of crystals were increased in the sequence of 2-amino-2-methyl-1-propanol (AMP) nuclear magnetic resonance, the additives favored the formation of bicarbonate ions by steric hindrance effect and increased the supersaturation of . It is shown that the additives increase the mean size of crystals and crystal growth rate by increasing supersaturation. The additives are promising for enhancing the removal efficiency and reducing the regeneration energy cost of absorbing solution by promoting crystallization.

A proposed method of efficient laser trapping of neutral radium atoms

We report theoretical studies of an efficient accumulation of 225Ra atoms in a magneto-optical trap (MOT) from an atomic beam. The number of atoms in the trap is limited due to the large leakage into metastable D states from the cooling transition and the loss mechanism from collisions with the background gases and with other elements in the atomic beam. We propose a setup consisting of an efficient Zeeman slower, an optical atomic beam deflector, and an Egg-MOT, which provides a large capture velocity, e.g. the Zeeman slower capture velocity of 581 ms−1 and the MOT capture velocity of 46 ms−1. Furthermore, the pure slow atomic beam produced by the optical atomic beam deflector can maximize the number of trapped atoms and their lifetime in a ultra high vacuum chamber by minimizing the collisional loss. Our proposed setup allows for the search for a permanent electric dipole moment based on laser-cooled and trapped radium atoms with improved sensitivity.

Oxygen vacancy and EC − 1 eV electron trap in ZnO

Fourier transform deep level transient spectroscopy has been performed between 80 and 550 K in five n-type ZnO samples grown by different techniques. The capture cross section and ionization energy of four electron traps have been deduced from Arrhenius diagrams. A trap 1 eV below the conduction band edge is systematically observed in the five samples with a large apparent capture cross section for electrons (1.6 ± 0.4 × 10−13 cm2) indicating a donor character. The assignment of this deep level to the oxygen vacancy is discussed on the basis of available theoretical predictions.

Integration of molecular network data reconstructs Gene Ontology.

Motivation: Recently, a shift was made from using Gene Ontology (GO) to evaluate molecular network data to using these data to construct and evaluate GO. Dutkowski et al. provide the first evidence that a large part of GO can be reconstructed solely from topologies of molecular networks. Motivated by this work, we develop a novel data integration framework that integrates multiple types of molecular network data to reconstruct and update GO. We ask how much of GO can be recovered by integrating various molecular interaction data.Results: We introduce a computational framework for integration of various biological networks using penalized non-negative matrix tri-factorization (PNMTF). It takes all network data in a matrix form and performs simultaneous clustering of genes and GO terms, inducing new relations between genes and GO terms (annotations) and between GO terms themselves. To improve the accuracy of our predicted relations, we extend the integration methodology to include additional topological information represented as the similarity in wiring around non-interacting genes. Surprisingly, by integrating topologies of bakers’ yeasts protein–protein interaction, genetic interaction (GI) and co-expression networks, our method reports as related 96% of GO terms that are directly related in GO. The inclusion of the wiring similarity of non-interacting genes contributes 6% to this large GO term association capture. Furthermore, we use our method to infer new relationships between GO terms solely from the topologies of these networks and validate 44% of our predictions in the literature. In addition, our integration method reproduces 48% of cellular component, 41% of molecular function and 41% of biological process GO terms, outperforming the previous method in the former two domains of GO. Finally, we predict new GO annotations of yeast genes and validate our predictions through GIs profiling.Availability and implementation: Supplementary Tables of new GO term associations and predicted gene annotations are available at http://bio-nets.doc.ic.ac.uk/GO-Reconstruction/.Contact: natasha@imperial.ac.ukSupplementary information: Supplementary data are available at Bioinformatics online.

Modelling character motions on infinite-dimensional manifolds

In this article, we will formulate a mathematical framework that allows us to treat character animations as points on infinite-dimensional Hilbert manifolds. Constructing geodesic paths between animations on those manifolds allows us to derive a distance function to measure similarities of different motions. This approach is derived from the field of geometric shape analysis, where such formalisms have been used to facilitate object recognition tasks. Analogously to the idea of shape spaces, we construct motion spaces consisting of equivalence classes of animations under reparametrizations. Especially cyclic motions can be represented elegantly in this framework. We demonstrate the suitability of this approach in multiple applications in the field of computer animation. First, we show how visual artefacts in cyclic animations can be removed by applying a computationally efficient manifold projection method. We next highlight how geodesic paths can be used to calculate interpolations between various animations in a computationally stable way. Finally, we show how the same mathematical framework can be used to perform cluster analysis on large motion capture databases, which can be used for or as part of motion retrieval problems.