Dynamic Tracing Research Articles

Viability, Information Seeking, and Vote Choice

Existing research suggests that candidate viability influences strategic voting decisions among citizens. We argue that viability can influence electoral decision making beyond strategic considerations. We analyze original experimental data and novel observational data to examine viability’s impact on vote choice and information seeking. We conduct two mock primary election campaigns within the Dynamic Process Tracing Environment where we experimentally manipulate candidate viability. In both experiments, we find that subjects read more information about viable candidates, report more favorable ratings of viable candidates, and are more likely to vote for viable candidates. We demonstrate the generalizability of these results by assessing the relationship between viability, as measured with Gallup polls, and information seeking using observational data. There, we develop a unique measure of information seeking based on Google searches for the names of political candidates. These observational data reinfor...

Studies on the effect of concentration of formaldehyde on the synthesis of resole-type epoxidized phenolic resin from renewable resource material

Epoxidized cardanol/formaldehyde resins (ERCF) were synthesized by reacting resole type cardanol/formaldehyde resin and epichlorohydrin in basic medium at 120 °C. Resole-type phenolic resins were synthesized by reacting cardanol and formaldehyde (molar ratios 1:1.3, 1:1.5, 1:1.7, 1:1.9,and 1:2.1) in the presence of sodium hydroxide, as catalyst, at five different temperatures ranging between 60 and 80 °C with an interval of 5°C for a maximum period of 6 h. A set of samples were characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopic analysis. The molecular size distribution of resole phenolics was studied by high-resolution gel permeation chromatography. Differential scanning calorimetry technique was used to investigate the curing behavior of the synthesized epoxy resins. Single-step mass loss in dynamic thermo gravimetric traces for the ERCF was observed.

Magnetic and fluorescent bifunctional chitosan microspheres embedding with fluorescent-labeling drug as a drug delivery system

The fluorescent marker in the drug delivery system (DDS) is very critical to achieve dynamic tracing of drug. However, the DDS embedded with fluorescent materials is not capable of detecting the release of drug precisely, since the separated fluorescent substrate and drug do not release and diffuse simultaneously. To increase the accuracy of tracing drug, we prepared fluorescent-labeling drug Gd(aspirin)3·2H2O by covalent binding of rare earth ion Gd3+ with aspirin. Fe3O4 magnetic nanoparticles as the magnetic targeting carrier and Gd(aspirin)3·2H2O as the fluorescent-labeling drug were incorporated into chitosan microspheres to prepare magnetic and fluorescent chitosan microspheres as a DDS. Investigated by Fourier transform infrared spectrometer, Varioskan Flash, X-ray diffraction, vibrating sample magnetometer, transmission electron microscope, and scanning electron microscope, the DDS with fluorescent-labeling drug showed good fluorescent and magnetic properties.

Two-point paraxial traveltime formula for inhomogeneous isotropic and anisotropic media: Tests of accuracy

On several simple models of isotropic and anisotropic media, we have studied the accuracy of the two-point paraxial traveltime formula designed for the approximate calculation of the traveltime between points [Formula: see text] and [Formula: see text] located in the vicinity of points [Formula: see text] and [Formula: see text] on a reference ray. The reference ray may be situated in a 3D inhomogeneous isotropic or anisotropic medium with or without smooth curved interfaces. The two-point paraxial traveltime formula has the form of the Taylor expansion of the two-point traveltime with respect to spatial Cartesian coordinates up to quadratic terms at points [Formula: see text] and [Formula: see text] on the reference ray. The constant term and the coefficients of the linear and quadratic terms are determined from quantities obtained from ray tracing and linear dynamic ray tracing along the reference ray. The use of linear dynamic ray tracing allows the evaluation of the quadratic terms in arbitrarily inhomogeneous media and, as shown by examples, it extends the region of accurate results around the reference ray between [Formula: see text] and [Formula: see text] (and even outside this interval) obtained with the linear terms only. Although the formula may be used for very general 3D models, we concentrated on simple 2D models of smoothly inhomogeneous isotropic and anisotropic ([Formula: see text] and [Formula: see text] anisotropy) media only. On tests, in which we estimated two-point traveltimes between a shifted source and a system of shifted receivers, we found that the formula may yield more accurate results than the numerical solution of an eikonal-based differential equation. The tests also indicated that the accuracy of the formula depends primarily on the length and the curvature of the reference ray and only weakly depends on anisotropy. The greater is the curvature of the reference ray, the narrower its vicinity, in which the formula yields accurate results.

True-amplitude Kirchhoff depth migration in anisotropic media: The traveltime-based approach

True-amplitude Kirchhoff depth migration is a classic tool in seismic imaging. In addition to a focused structural image, it also provides information on the strength of the reflectors in the model, leading to estimates of the shear properties of the subsurface. This information is a key feature not only for reservoir characterization, but it is also important for detecting seismic anisotropy. If anisotropy is present, it needs to be accounted for during the migration. True-amplitude Kirchhoff depth migration is carried out in terms of a weighted diffraction stack. Expressions for suitable weight functions exist in anisotropic media. However, the conventional means of computing the weights is based on dynamic ray tracing, which has high requirements on the smoothness of the underlying model. We developed a method for the computation of the weight functions that does not require dynamic ray tracing because all necessary quantities are determined from traveltimes alone. In addition, the method led to considerable savings in computational costs. This so-called traveltime-based strategy was already introduced for isotropic media. We extended the strategy to incorporate anisotropy. For verification purposes and comparison to analytic references, we evaluated 2.5D migration examples for [Formula: see text] and [Formula: see text] reflections. Our results confirmed the high image quality and the accuracy of the reconstructed reflectivities.

Research on Optimization Method of Real-Time Available Resources for Dynamic Scheduling

Aimed at the real-time request of dynamic scheduling to product resource, an optimization method of parallel dynamic chain real-time available resources was put forward. Proceed from real-time tracing of resource information influencing scheduling tasks dynamic property, established a resource informations real-time tracing back and optimization model, which used module and parallel process mechanism to different kinds of real-time traced back resource information. The mechanism processed global dynamic feedback tracing for every module and optimized available resources primarily, on this basis, graded the primary available resources and gave a real-time candidate resource set. Through one example of one gear production scheduling, the methods validity was tested.

The Analysis of Definition of Large Projects Basing on Time and Space Scales

Study of large project management basing on the research of time and space scales is the at the forefront of the trend.But for now, it is still resting on the basic work stage for large projects based on the time space multi-dimensional definition. A large project construction and operation is bound to place on the space area and near projects of social and economic impact, in addition to the internal effects and characteristics. What is more, it will reflect the index at different stages of dynamic change in the time series. This article will make an analysis of large-scale spatial spillover effects of the project and have the selection of large projects indicators which can reflect on regional economic and social impact. Besides this article is from the perspective of time and space, applying the spatial econometrics, it dynamic traces of index in time scale, analysis, reflects the characteristics of a large project for large projects.

Emergence of Dynamic Memory Traces in Cortical Microcircuit Models through STDP

Numerous experimental data suggest that simultaneously or sequentially activated assemblies of neurons play a key role in the storage and computational use of long-term memory in the brain. However, a model that elucidates how these memory traces could emerge through spike-timing-dependent plasticity (STDP) has been missing. We show here that stimulus-specific assemblies of neurons emerge automatically through STDP in a simple cortical microcircuit model. The model that we consider is a randomly connected network of well known microcircuit motifs: pyramidal cells with lateral inhibition. We show that the emergent assembly codes for repeatedly occurring spatiotemporal input patterns tend to fire in some loose, sequential manner that is reminiscent of experimentally observed stereotypical trajectories of network states. We also show that the emergent assembly codes add an important computational capability to standard models for online computations in cortical microcircuits: the capability to integrate information from long-term memory with information from novel spike inputs.

A Fast and Accurate Scheme for Travel-Time Computations and Ray-Path Determinations of Global Seismic Phases in a Laterally Heterogeneous Model

The pioneering work of Jeffreys and Bullen (1940; JB Tables) established the first truly global seismological travel‐time tables, which have fulfilled a vital and important role in performing earthquake locations and seismic tomography. Such information has enriched our knowledge about the inner structure of the Earth and its dynamic processes. The JB travel‐time tables, which are based on 1D velocity model (radial dependence only), have gradually improved over the years through a series of modifications, for example, the PREM model (Dziewonski and Anderson, 1981), the IASP91 model (Kennett and Engdahl, 1991) and the AK135 model (Kennett et al. , 1995). The major source of error in travel‐time prediction with these tables is due to from unincorporated lateral heterogeneities in the true velocity structure of the Earth. For traditional purposes of earthquake location, the global travel‐time tables (i.e., ISAP91 or AK135) have been generalized by a ray‐parameter method, such as a tau‐p function integral method of Buland and Chapman (1983). Some modified versions of the tau‐p function integral method are available, for example, the TauP Toolkit software (Crotwell et al. , 1999) and TTBox software (Knapmeyer, 2004), which offer improvements in computational efficiency and flexibility of usage. For purposes of global travel‐time tomography, there exist a variety of schemes to predict the travel‐times for a couple of the important global phases. They include perturbation theory (Bijwaard and Spakman, 1999), dynamic ray tracing (Dahlen et al. , 2000), the pseudo‐bending method (Zhao, 2001) nd generalized ray theory (Ballard et al. , 2009), in which most of the global phases are not predicted and accommodated, for example, later phases with the minimax time‐path (see Ray Tracing for Phases with a Stationary Minimax Time Path section for detailed …

A note on two-point paraxial travel times

Recently, several expressions for the two-point paraxial travel time in laterally varying, isotropic or anisotropic layered media were derived. The two-point paraxial travel time gives the travel time from point S′ to point R′, both these points being situated close to a known reference ray Ω, along which the ray-propagator matrix was calculated by dynamic ray tracing. The reference ray and the position of points S′ and R′ are specified in Cartesian coordinates. Two such expressions for the two-point paraxial travel time play an important role. The first is based on the 4 × 4 ray propagator matrix, computed by dynamic ray tracing along the reference ray in ray-centred coordinates. The second requires the knowledge of the 6 × 6 ray propagator matrix computed by dynamic ray tracing along the reference ray in Cartesian coordinates. Both expressions were derived fully independently, using different methods, and are expressed in quite different forms. In this paper we prove that the two expressions are fully equivalent and can be transformed into each other.

Matching design of hydraulic load simulator with aerocraft actuator

This paper intends to provide theoretical basis for matching design of hydraulic load simulator (HLS) with aerocraft actuator in hardware-in-loop test, which is expected to help actuator designers overcome the obstacles in putting forward appropriate requirements of HLS. Traditional research overemphasizes the optimization of parameters and methods for HLS controllers. It lacks deliberation because experimental results and project experiences indicate different ultimate performance of a specific HLS. When the actuator paired with this HLS is replaced, the dynamic response and tracing precision of this HLS also change, and sometimes the whole system goes so far as to lose control. Based on the influence analysis of the preceding phenomena, a theory about matching design of aerocraft actuator with HLS is presented, together with two paired new concepts of “Standard Actuator” and “Standard HLS”. Further research leads to seven important conclusions of matching design, which suggest that appropriate stiffness and output torque of HLS should be carefully designed and chosen for an actuator. Simulation results strongly support that the proposed principle of matching design can be anticipated to be one of the design criteria for HLS, and successfully used to explain experimental phenomena and project experiences.

Dynamic Tardos Traitor Tracing Schemes

We construct binary dynamic traitor tracing schemes, where the number of watermark bits needed to trace and disconnect any coalition of pirates is quadratic in the number of pirates, and logarithmic in the total number of users and the error probability. Our results improve upon results of Tassa, and our schemes have several other advantages, such as being able to generate all codewords in advance, a simple accusation method, and flexibility when the feedback from the pirate network is delayed.

Lateral migration of an elastic capsule by optical force in a uniform flow

The lateral migration of an elastic capsule under an optical force in a uniform flow was studied to show the separation characteristics according to the elastic properties in the cross-type optical separator. The initially spherical capsule was moved through the fluid flow using a laser beam with a Gaussian distribution focused along the direction normal to the flow device surface. To simulate such a system, a penalty immersed boundary method was adopted to enable fluid-membrane coupling, and a dynamic ray tracing method was applied to the optical force calculation. The effects of the elastic properties of the capsule membrane (the surface Young's modulus and the bending modulus) on the lateral migration were studied. By increasing the surface Young's modulus, the capsule deformed less and the migration distance increased; however, buckling occurred in the capsule with a high surface Young's modulus. Buckling could be suppressed by increasing the bending rigidity. The effects of the flow velocity and the laser beam power were also examined. In the simulation, the S number, i.e., the ratio of the optical force to the viscous force, was adjusted by decreasing the flow velocity or increasing the laser beam power. The migration distance increased as the S number increased, and a constant lateral migration distance was obtained for a rigid particle for a given S number. An elastic capsule under conditions intermediate between a fixed flow velocity and a fixed laser beam power, however, did not yield a constant lateral migration distance due to the extent of the deformation in the different situations. To predict the lateral migration distance of an elastic capsule, a nondimensional parameter, S_{e}, was defined to include the effects of the optical force, the elastic force, and the fluid viscous force. A unified tendency of the lateral migration distance with S_{e} was obtained for capsules with intermediate elasticity, by varying either the flow velocity or the laser beam power.

Direct and Dynamic Detection of HIV-1 in Living Cells

In basic and applied HIV research, reliable detection of viral components is crucial to monitor progression of infection. While it is routine to detect structural viral proteins in vitro for diagnostic purposes, it previously remained impossible to directly and dynamically visualize HIV in living cells without genetic modification of the virus. Here, we describe a novel fluorescent biosensor to dynamically trace HIV-1 morphogenesis in living cells. We generated a camelid single domain antibody that specifically binds the HIV-1 capsid protein (CA) at subnanomolar affinity and fused it to fluorescent proteins. The resulting fluorescent chromobody specifically recognizes the CA-harbouring HIV-1 Gag precursor protein in living cells and is applicable in various advanced light microscopy systems. Confocal live cell microscopy and super-resolution microscopy allowed detection and dynamic tracing of individual virion assemblies at the plasma membrane. The analysis of subcellular binding kinetics showed cytoplasmic antigen recognition and incorporation into virion assembly sites. Finally, we demonstrate the use of this new reporter in automated image analysis, providing a robust tool for cell-based HIV research.

Two Studies of Framework-Usage Templates Extracted from Dynamic Traces

Object-oriented frameworks are widely used to develop new applications. They provide reusable concepts that are instantiated in application code through potentially complex implementation steps such as subclassing, implementing interfaces, and calling framework operations. Unfortunately, many modern frameworks are difficult to use because of their large and complex APIs and frequently incomplete user documentation. To cope with these problems, developers often use existing framework applications as a guide. However, locating concept implementations in those sample applications is typically challenging due to code tangling and scattering. To address this challenge, we introduce the notion of concept-implementation templates, which summarize the necessary concept-implementation steps and identify them in the sample application code, and a technique, named FUDA, to automatically extract such templates from dynamic traces of sample applications. This paper further presents the results of two experiments conducted to evaluate the quality and usefulness of FUDA templates. The experimental evaluation of FUDA with 14 concepts in five widely used frameworks suggests that the technique is effective in producing templates with relatively few false positives and false negatives for realistic concepts by using two sample applications. Moreover, we observed in a user study with 28 programmers that the use of templates reduced the concept-implementation time compared to when documentation was used.

Fay

Fay is a flexible platform for the efficient collection, processing, and analysis of software execution traces. Fay provides dynamic tracing through use of runtime instrumentation and distributed aggregation within machines and across clusters. At the lowest level, Fay can be safely extended with new tracing primitives, including even untrusted, fully optimized machine code, and Fay can be applied to running user-mode or kernel-mode software without compromising system stability. At the highest level, Fay provides a unified, declarative means of specifying what events to trace, as well as the aggregation, processing, and analysis of those events. We have implemented the Fay tracing platform for Windows and integrated it with two powerful, expressive systems for distributed programming. Our implementation is easy to use, can be applied to unmodified production systems, and provides primitives that allow the overhead of tracing to be greatly reduced, compared to previous dynamic tracing platforms. To show the generality of Fay tracing, we reimplement, in experiments, a range of tracing strategies and several custom mechanisms from existing tracing frameworks. Fay shows that modern techniques for high-level querying and data-parallel processing of disagreggated data streams are well suited to comprehensive monitoring of software execution in distributed systems. Revisiting a lesson from the late 1960s [Deutsch and Grant 1971], Fay also demonstrates the efficiency and extensibility benefits of using safe, statically verified machine code as the basis for low-level execution tracing. Finally, Fay establishes that, by automatically deriving optimized query plans and code for safe extensions, the expressiveness and performance of high-level tracing queries can equal or even surpass that of specialized monitoring tools.

Optical levitation of a non-spherical particle in a loosely focused Gaussian beam

The optical force on a non-spherical particle subjected to a loosely focused laser beam was calculated using the dynamic ray tracing method. Ellipsoidal particles with different aspect ratios, inclination angles, and positions were modeled, and the effects of these parameters on the optical force were examined. The vertical component of the optical force parallel to the laser beam axis decreased as the aspect ratio decreased, whereas the ellipsoid with a small aspect ratio and a large inclination angle experienced a large vertical optical force. The ellipsoids were pulled toward or repelled away from the laser beam axis, depending on the inclination angle, and they experienced a torque near the focal point. The behavior of the ellipsoids in a viscous fluid was examined by analyzing a dynamic simulation based on the penalty immersed boundary method. As the ellipsoids levitated along the direction of the laser beam propagation, they moved horizontally with rotation. Except for the ellipsoid with a small aspect ratio and a zero inclination angle near the focal point, the ellipsoids rotated until the major axis aligned with the laser beam axis.

On the Edgeworth‐Kuiper Belt dust flux to Saturn

Dust grains originating from the Edgeworth‐Kuiper Belt (EKB) are believed to be the dominant species of dust in the outer solar system. These grains, evolving inward from the EKB under the influence of a variety of forces, will encounter the giant planets or their ring and moon systems. At Saturn, this influx drives several physical processes including the generation of tenuous dusty exospheres and rings, the spatial and compositional evolution of Saturn's main planetary ring system, and the generation of ionospheric and neutral gas layers in the atmospheres of Saturn and Titan. Recent comparisons between in‐situ dust density measurements in the outer solar system and a dynamical dust grain tracing model have placed experimental limits on the mass production rate and power‐law exponent of EKB‐generated grains. Using this model and the experimental constraints, we make predictions for the influx of micron‐sized, EKB‐generated grains into the saturnian system, where the Cosmic Dust Analyzer onboard the Cassini mission is currently making measurements of both endogenous and exogenous dust populations.

Quantifying and Tracing Information Cascades in Swarms

We propose a novel, information-theoretic, characterisation of cascades within the spatiotemporal dynamics of swarms, explicitly measuring the extent of collective communications. This is complemented by dynamic tracing of collective memory, as another element of distributed computation, which represents capacity for swarm coherence. The approach deals with both global and local information dynamics, ultimately discovering diverse ways in which an individual’s spatial position is related to its information processing role. It also allows us to contrast cascades that propagate conflicting information with waves of coordinated motion. Most importantly, our simulation experiments provide the first direct information-theoretic evidence (verified in a simulation setting) for the long-held conjecture that the information cascades occur in waves rippling through the swarm. Our experiments also exemplify how features of swarm dynamics, such as cascades’ wavefronts, can be filtered and predicted. We observed that maximal information transfer tends to follow the stage with maximal collective memory, and principles like this may be generalised in wider biological and social contexts.

Long-term tracing of whole catchment 15N additions in a mountain spruce forest: measurements and simulations with the TRACE model

Despite numerous studies on nitrogen (N) cycling in forest ecosystems, many uncertainties remain, particularly regarding long-term N accumulation in the soil. Models validated against tracer isotopic data from field labeling experiments provide a potential tool to better understand and simulate C and N interactions over multiple decades. In this study, we describe the adaptation of the dynamic process-based model TRACE to a new site, Alptal, where long-term N-addition and 15N-tracer experiments provide unique datasets for testing the model. We describe model parameterization for this spruce forest, and then test the model with 9- and 14-year time series of 15N-tracer recovery from control and N-amended catchments, respectively. Finally, we use the model to project the fate of ecosystem N accumulation over the next 70 years. Field 15N recovery data show that the major sink for N deposition is the soil. On the control plot, tracer recovery in the soil increased from 32 % in the second year to 60 % in the ninth year following tracer addition, whereas on the N-saturated plot, soil recovery stayed almost constant from 63 % in the third year to 61 % in the twelfth year. Recovery in tree biomass increased over the decadal time scale in both treatments, to ca. 10 % over 9 years on the control plot and ca. 13 % over 14 years on the N-amended plot. We then used these time series to validate TRACE, showing that the adaptation and calibration procedure for the Alptal site was successful. Model-data comparison identified that the spreading method of 15N tracers needs to be considered when interpreting recovery results from labeling studies. Furthermore, the ground vegetation layer was recognized to play an important role in controlling the rate at which deposited N enters soil pools. Our 70-year model simulation into the future underpinned by a Monte-Carlo sensitivity analysis, suggests that the soil is able to immobilize a constant fraction of 70 and 77 % of deposited N for the treated and the control plot, respectively. Further, the model showed that the simulated increased N deposition resulted in a relatively small elevated C sequestration in aggrading wood with an N use efficiency of approximately 7 kg C per kg N added.