arXiv subjects

Weidong Huang

Publications and source records attributed to Weidong Huang.

36 records · Page 2Linked to original sources

arXiv2020

A new method for life table and life expectancy calculation

The existing life table method needs to calculate the age-specific mortality first, not only has too many and complicated calculation steps, but also introduces the multiple approximation to bring error. This paper redefines the probability of death for the life table as the average probability of death of a group of people born in a certain period at a later time. Based on this definition, a new method for the life table is proposed to obtain the life expectancy, which has the same meaning to that from the traditional life table. Using the Japanese population data to verify the method, the results show that it is consistent with the life expectancy of the birth of the baby, the maximum relative difference is no more than 0.1%, and average relative difference is less than 0.03%. The theory and method of life table described in this paper are simple and easy to understand. The needed data are easy to obtained from statistics, and the calculation is easy, the results obtained are accurate and reliable. It should be a very valuable demographic method for application.

q-bio.OT↗

arXiv2020

A new method to calculate the Total Fertility Rate from the number of birth

The standard methods to calculate the Total Fertility Rate require the reliable age-specific fertility rate including birth data and the related age-specific women's population data. Historically, the number of births was often not counted according to the age of the mother, so it is difficult to estimate the historical total fertility rate with the standard methods. Many empirical methods have been proposed, but their application is limited to specific period and place. This paper deduces a new method for calculating the total fertility rate from the number of birth and the population of women at childbearing age, can be applied to most of cases. The relative error is usually less than 5%. It is easier to calculate TFR, and may be applied to obtain more TFRs for the history.

q-bio.PE↗

arXiv2018

Error Compensated Quantized SGD and its Applications to Large-scale Distributed Optimization

Large-scale distributed optimization is of great importance in various applications. For data-parallel based distributed learning, the inter-node gradient communication often becomes the performance bottleneck. In this paper, we propose the error compensated quantized stochastic gradient descent algorithm to improve the training efficiency. Local gradients are quantized to reduce the communication overhead, and accumulated quantization error is utilized to speed up the convergence. Furthermore, we present theoretical analysis on the convergence behaviour, and demonstrate its advantage over competitors. Extensive experiments indicate that our algorithm can compress gradients by a factor of up to two magnitudes without performance degradation.

cs.CV↗

arXiv2016

Structure Based Aesthetics and Support of Cognitive Tasks for Graph Evaluation

Drawing principles, or aesthetics, are important in graph drawing. They are used as criteria for algorithm design and for quality evaluation. Current aesthetics are described as visual properties that a drawing is required to have to be visually pleasing. However, most of these aesthetics are originally proposed without consideration of graph structure information. Therefore their ability in visually revealing graph structural features are not guaranteed and indeed mixed results have been reported in the literature regarding their impact on user graph comprehension. In this paper, we propose to derive aesthetics based on graph internal structural features. Further, graphs are often evaluated based on controlled experiments with simple perception tasks to avoid possible confounding factors caused by complex tasks. This leaves their value in supporting complex tasks unevaluated. To fill this gap, we also discuss the possibility of applying evaluation methodologies used in the Cognitive Load Theory research for graph evaluation.

cs.HC↗

arXiv2016

Interfacial undercooling in the solidification of colloidal suspensions-analyses with quantitative measurements

Interfacial undercooling is of significant importance on microscopic pattern formation in the solidification of colloidal suspensions. Two kinds of interfacial undercooling are supposed to be involved in freezing colloidal suspensions, i.e. solute constitutional supercooling (SCS) caused by additives in the solvent and particulate constitutional supercooling (PCS) caused by particles. However, quantitatively identification of the interfacial undercooling of freezing colloidal suspensions is still absent and it is still unknown which undercooling is dominant. The revealing of interfacial undercooling is closely related to the design of ice-templating porous materials. Based on quantitative experimental measurements, we show that the interfacial undercooling mainly comes from SCS caused by the additives in the solvent, while the PCS can be ignored. This finding implies that the PCS theory is not the fundamental physical mechanism for patterning in the solidification of colloidal suspensions. Instead, the patterns in ice-templating method can be controlled effectively by adjusting the additives.

cond-mat.mtrl-sci↗

arXiv2015

In situ observation the interface undercooling of freezing colloidal suspensions with differential visualization method

Interface undercooling is one of the most significant parameters in the solidification of colloidal suspensions. However, quantitative measurement of interface undercooling of colloidal suspensions is still a challenge. Here, a new experimental facility and gauging method are designed to directly reveal the interface undercooling on both static and dynamic cases. The interface undercooling is visualized through the discrepancy of solid/liquid interface positions between the suspensions and its solvent in a thermal gradient apparatus. The resolutions of the experimental facility and gauging method are proved to be 0.01 K. The high precision of the method comes from the principle of converting temperature measurement into distance measurement in the thermal gradient platform. Moreover, both static and dynamic interface undercoolings can be quantitatively measured.

cond-mat.mtrl-sci↗

arXiv2014

Low artificial anisotropy cellular automaton model and its applications to the cell-to-dendrite transition in directional solidification

A low artificial anisotropy cellular automaton (CA) model is developed for the simulation of microstructure evolution in directional solidification. The CA model's capture rule was modified by a limited neighbor solid fraction (LNSF) method. Various interface curvature calculation methods have been compared. The simulated equilibrium shapes agree with the theoretical shapes, when the interface energy anisotropy coefficient is ε=0.01, ε=0.03 and ε=0.05, respectively.The low artificial anisotropy CA model is used in the numerical simulation of the cell-to-dendrite transition (CDT) in directional solidification. The influence of physical parameters (Γ, Dl, k0, ml) on CDT has been investigated. The main finding in this paper is the discovery of the changing behavior of the Vcd when the solute partition coefficient k0 is larger than a critical value. When k0 is less than 0.125, the Vcd follows the Kurz and Fisher criterion Vc/k0; while when k0>0.125, the Vcd equals to 8Vc. The experimental data of succinonitrile-acetone (SCN-ace, k0=0.1) and SCN-camphor (k0=0.33) support the conclusion from CA simulations.

cond-mat.mtrl-sci↗

arXiv2013

Designing a Network Based System for Delivery of Remote Mine Services

There is a great body of work in the areas of tele-assistance/tele-collaboration offering novel and effective ways to improve collaboration between personnel located at a remote mine site and off-site personnel located in major metropolitan areas. Much of this work involves the use of high-bandwidth communications or targeted sensory experiences using large format displays. There are also existing remote access technologies but these suffer from limited functionality (providing text, voice, video or one-way desktop sharing), are often poorly supported in the security-conscious corporate environment and require complicated set up processes. There is currently no singular piece of remote collaboration technology that is suitable for the delivery of high-quality planning and scheduling services to clients at a mining site from a remote operating centre. In response to this issue, as part of a research and technology development effort between CSIRO and a mining engineering firm, we have developed a concept of remote mining engineer (RME) and conducted a functional requirements analysis for delivering mining engineering services to mine sites remotely. Based on the obtained requirements, a further study was performed to characterise existing technologies and to identify the scope for future work in designing and prototyping a network based system for RME. We report on the method and findings of this study in this paper.

cs.HC↗

arXiv2013

An Aggregation-Based Overall Quality Measurement for Visualization

Aesthetics are often used to evaluate the quality of graph drawings. However, the existing aesthetic criteria are useful in judging the extents to which a drawing conforms to particular drawing rules. They have limitations in evaluating overall quality. Currently the overall quality of graph drawings is mainly evaluated based on personal judgments and user studies. Personal judgments are not reliable, while user studies can be costly to run. Therefore, there is a need for a direct measure of overall quality. This measure can be used by visualization designers to quickly compare the quality of drawings at hand at the design stage and make decisions accordingly. In an attempt to meet this need, we propose a measure that measures overall quality based on aggregation of individual aesthetic criteria. We present a user study that validates this measure and demonstrates its capacity in predicting the performance of human graph comprehension. The implications of the proposed measure for future research are discussed.

cs.HC↗

arXiv2011

HandsInAir: A Wearable System for Remote Collaboration

We present HandsInAir, a real-time collaborative wearable system for remote collaboration. The system is developed to support real world scenarios in which a remote mobile helper guides a local mobile worker performing a physical task. HandsInAir implements a novel approach to support mobility of remote collaborators. This approach allows the helper to perform gestures without having to touch tangible objects, requiring little environment support. The system consists of two parts: the helper part and the worker part. The two parts are connected via a wireless network and the collaboration partners communicate with each other via audio and visual links. In this paper, we review related work, describe technical implementation of the system and envision future work for further improvements.

cs.HC↗

arXiv2011

Prediction and optimization of the performance of parabolic solar dish concentrator with sphere receiver using analytical function

Parabolic solar dish concentrator with sphere receiver is less studied. We present an analytic function to calculate the intercept factor of the system with real sun bright distribution and Gaussian distribution, the results indicate that the intercept factor is related to the rim angle of reflector and the ratio of open angle of receiver at the top of reflector to optical error when the optical error is larger than or equal to 5 mrad, but is related to the rim angle, open angle and optical error in less than 5 mrad optical error. Furthermore we propose a quick process to optimize the system to provide the maximum solar energy to net heat efficiency for different optical error under typical condition. The results indicate that the parabolic solar dish concentrator with sphere receiver has rather high solar energy to net heat efficiency which is 20% more than solar trough and tower system including higher cosine factor and lower heat loss of the receiver.

physics.optics↗

arXiv2011

Theoretical analysis of error transfer from surface slope to refractive ray and their application to the solar concentrated collector

This paper presents the general equation to calculate the standard deviation of reflected ray error from optical error through geometry optics, applying the equation to calculate the standard deviation of reflected ray error for 8 kinds of solar concentrated reflector, provide typical results. The results indicate that the slope errors in two direction is transferred to any one direction of the focus ray when the incidence angle is more than 0 for solar trough and heliostats reflector; for point focus Fresnel lens, point focus parabolic glass mirror, line focus parabolic galss mirror, the error transferring coefficient from optical to focus ray will increase when the rim angle increase; for TIR-R concentrator, it will decrease; for glass heliostat, it relates to the incidence angle and azimuth of the reflecting point. Keywords: optic error, standard deviation, refractive ray error, concentrated solar collector

physics.optics↗

arXiv2011

Theoretical analysis of reflected ray error from surface slope error and their application to the solar concentrated collector

Surface slope error of concentrator is one of the main factors to influence the performance of the solar concentrated collectors which cause deviation of reflected ray and reduce the intercepted radiation. This paper presents the general equation to calculate the standard deviation of reflected ray error from slope error through geometry optics, applying the equation to calculate the standard deviation of reflected ray error for 5 kinds of solar concentrated reflector, provide typical results. The results indicate that the slope error is transferred to the reflected ray in more than 2 folds when the incidence angle is more than 0. The equation for reflected ray error is generally fit for all reflection surfaces, and can also be applied to control the error in designing an abaxial optical system.

physics.optics↗

arXiv2011

Orientation selection of equiaxed dendritic growth by three-dimensional cellular automaton model

A three-dimensional (3-D) adaptive mesh refinement (AMR) cellular automata (CA) model is developed to simulate the equiaxed dendritic growth of pure substance. In order to reduce the mesh induced anisotropy by CA capture rules, a limited neighbor solid fraction (LNSF) method is presented. An expansion description using two interface free energy anisotropy parameters (\epsilon1, \epsilon2) is used in present 3-D CA model. The dendrite growths with the orientation selection between <100> and <110> are discussed using the different \epsilon1 with \epsilon2=-0.02. It is found that the simulated morphologies by present CA model are as expected from the minimum stiffness criterion.

nlin.CG↗

arXiv2010

A Force-Directed Method for Large Crossing Angle Graph Drawing

Recent empirical research has indicated that human graph reading performance improves when crossing angles increase. However, crossing angle has not been used as an aesthetic criterion for graph drawing algorithms so far. In this paper, we introduce a force-directed method that aims to construct graph drawings with large crossing angles. Experiments indicate that our method significantly increases crossing angles. Surprisingly, the experimental results further demonstrate that the resulting drawings produced by our method have fewer edge crossings, a shorter total edge length and more uniform edge lengths, compared to classical spring algorithms.

cs.HC↗

arXiv2010

Synthesis of Sugar and fixation of CO2 through Artificial Photosynthesis driving by Hydrogen or Electricity

The overall process of photosynthesis consists of two main phases, the so-called light and dark eactions: light energy is absorbed by chlorophyll molecules and transferred to regenerate NADH and ATP, then drive Calvin-Benson cycle to synthesize sugar. In order to synthesize sugar through artificial photosynthesis, one of the key is to regenerate ATP economically and improve the efficiency of dark reactions. Here 9 kinds of dark reaction pathways are proposed, which only NADH is regenearated from hydrogen or electricity for driving, the efficiency of dark reactions is improved, combined with solar photovoltaic or solar hydrogen technology, the total efficiency of artificial photosynthesis can reach 30%, several ten times more than natural photosynthesis. One of them, to use chemical synthesis of formaldehyde from CO2 and H2, no NADH and ATP is need, to synthesize sugar efficiently through 9 enzymes, so it will be easier to produce in large scale, and the sugar will be a good energy carrier as the sugar can be efficiently converted to energy carrier hydrogen through enzymes.

physics.chem-ph↗

arXiv2008

An Eye Tracking Study into the Effects of Graph Layout

Graphs are typically visualized as node-link diagrams. Although there is a fair amount of research focusing on crossing minimization to improve readability, little attention has been paid on how to handle crossings when they are an essential part of the final visualizations. This requires us to understand how people read graphs and how crossings affect reading performance. As an initial step to this end, a preliminary eye tracking experiment was conducted. The specific purpose of this experiment was to test the effects of crossing angles and geometric-path tendency on eye movements and performance. Sixteen subjects performed both path search and node locating tasks with six drawings. The results showed that small angles can slow down and trigger extra eye movements, causing delays for path search tasks, whereas crossings have little impact on node locating tasks. Geometric-path tendency indicates that a path between two nodes can become harder to follow when many branches of the path go toward the target node. The insights obtained are discussed with a view to further confirmation in future work.

cs.HC↗

arXiv2005

Computational Fluid Dynamic Approach for Biological System Modeling

Various biological system models have been proposed in systems biology, which are based on the complex biological reactions kinetic of various components. These models are not practical because we lack of kinetic information. In this paper, it is found that the enzymatic reaction and multi-order reaction rate is often controlled by the transport of the reactants in biological systems. A Computational Fluid Dynamic (CFD) approach, which is based on transport of the components and kinetics of biological reactions, is introduced for biological system modeling. We apply this approach to a biological wastewater treatment system for the study of metabolism of organic carbon substrates and the population of microbial. The results show that CFD model coupled with reaction kinetics is more accurate and more feasible than kinetic models for biological system modeling.

q-bio.QM↗