275 research outputs found
SparseGAN: Sparse Generative Adversarial Network for Text Generation
It is still a challenging task to learn a neural text generation model under
the framework of generative adversarial networks (GANs) since the entire
training process is not differentiable. The existing training strategies either
suffer from unreliable gradient estimations or imprecise sentence
representations. Inspired by the principle of sparse coding, we propose a
SparseGAN that generates semantic-interpretable, but sparse sentence
representations as inputs to the discriminator. The key idea is that we treat
an embedding matrix as an over-complete dictionary, and use a linear
combination of very few selected word embeddings to approximate the output
feature representation of the generator at each time step. With such
semantic-rich representations, we not only reduce unnecessary noises for
efficient adversarial training, but also make the entire training process fully
differentiable. Experiments on multiple text generation datasets yield
performance improvements, especially in sequence-level metrics, such as BLEU
Improving Simulation Efficiency of MCMC for Inverse Modeling of Hydrologic Systems with a Kalman-Inspired Proposal Distribution
Bayesian analysis is widely used in science and engineering for real-time
forecasting, decision making, and to help unravel the processes that explain
the observed data. These data are some deterministic and/or stochastic
transformations of the underlying parameters. A key task is then to summarize
the posterior distribution of these parameters. When models become too
difficult to analyze analytically, Monte Carlo methods can be used to
approximate the target distribution. Of these, Markov chain Monte Carlo (MCMC)
methods are particularly powerful. Such methods generate a random walk through
the parameter space and, under strict conditions of reversibility and
ergodicity, will successively visit solutions with frequency proportional to
the underlying target density. This requires a proposal distribution that
generates candidate solutions starting from an arbitrary initial state. The
speed of the sampled chains converging to the target distribution deteriorates
rapidly, however, with increasing parameter dimensionality. In this paper, we
introduce a new proposal distribution that enhances significantly the
efficiency of MCMC simulation for highly parameterized models. This proposal
distribution exploits the cross-covariance of model parameters, measurements
and model outputs, and generates candidate states much alike the analysis step
in the Kalman filter. We embed the Kalman-inspired proposal distribution in the
DREAM algorithm during burn-in, and present several numerical experiments with
complex, high-dimensional or multi-modal target distributions. Results
demonstrate that this new proposal distribution can greatly improve simulation
efficiency of MCMC. Specifically, we observe a speed-up on the order of 10-30
times for groundwater models with more than one-hundred parameters
Dynamic Reliability Assessment of Heavy Vehicle Crossing a Prototype Bridge Deck by Using Simulation Technology and Health Monitoring Data
Overloads of vehicle may cause damage to bridge structures, and how to assess the safety influence of heavy vehicles crossing the prototype bridge is one of the challenges. In this report, using a large amount of monitored data collected from the structural health monitoring system (SHMS) in service of the prototype bridge, of which the bridge type is large-span continuous rigid frame bridge, and adopting FEM simulation technique, we suggested a dynamic reliability assessment method in the report to assess the safety impact of heavy vehicles on the prototype bridge during operation. In the first place, by using the health monitored strain data, of which the selected monitored data time range is before the opening of traffic, the quasi dynamic reliability around the embedded sensor with no traffic load effects is obtained; then, with FEM technology, the FEM simulation model of one main span of the prototype bridge is built by using ANSYS software and then the dynamic reliability when the heavy vehicles crossing the prototype bridge corresponding to the middle-span web plate is comprehensively analyzed and discussed. At last, assuming that the main beam stress state change is in the stage of approximately linear elasticity under heavy vehicle loads impact, the authors got the impact level of heavy vehicles effects on the dynamic reliability of the prototype bridge. Based on a large number of field measured data, the dynamic reliability value calculated by our proposed methodology is more accurate. The method suggested in the paper can do good for not only the traffic management but also the damage analysis of bridges
Effect of Ba-Duan-Jin on Immune Function and Autonomic Nervous Balance in Ageing People
[Objective] Ba-Duan-Jin, formed in the 12th century, is an excellent traditional Chinese health exercises. Ancients likened it to “brocade (Jin)”, meaning its action is as elegant as brocade. The total movements are divided into 8 sections, so it is called “ Ba-Duan-Jin (8-section-action)”. Because of its simple action and significantly healthy effect, Ba-Duan-Jin is widely used to enhance physical fitness and prevent diseases. This study was aimed to evaluate the immunological effect of Ba-Duan-Jin in ageing people and analyze its autonomic nervous mechanism.
[Methods] 60 healthy women (64.06±2.53 years old) were divided into exercising group and sedentary group. Exercising group trained Ba-Duan-Jin 12 weeks(5 day/week, 3 repetition/day). Record electrocardiosignal to analyze heart rate variability (HRV) , and then take blood sample to measure blood routine, immune globulin, complement, sub-T lymphocyte, catecholamines and acetylcholine. These measurements were performed before and after the 8-week’s intervening duration.
[Results] The plasma immune globulin, complement, catecholamines and acetylcholine have no significant difference between two groups. But when it came to lymphocyte in peripheral blood, the women in exercising group have less CD8+ T-lymphocyte and higher rate of CD4+/CD8+ than sedentary group. The analysis of HRV showed an increasing total HRV (TF), a enhanced activity of parasympathetic nerve (RRmean, SDNN, RMSSD, HFnorm) and an attenuated activity of sympathetic nerve (LFnorm) in Ba-Duan-Jin exercising group. Correlation analysis confirmed that there is a close relationship between immune function and autonomic nervous activities.
[Conclusion] Ba-Duan-Jin can transfer the autonomic nervous balance to parasympathetic dominance, which may partially explain the increasing immunity function (especially in cell immunity) in ageing people.
Fig: the 8 sections of Ba-Duan-Jin
Note: 1. Holding heaven in the palms2. Posing as an archer shooting3. Holding one arm aloft4. Looking backward5. Swinging the head and lowering the body6. Moving the hands down the back and legs, and touching the Feet7. Thrusting the fists and making the eyes glare8. Raising and Lowering the Heel
Endoscopic Approaches to the Treatment of Variceal Hemorrhage in Hemodialysis-Dependent Patients
Background. Esophagogastric variceal hemorrhage leads to challenging situation in chronic kidney disease patients on maintenance hemodialysis. Aims. To determine the safety and efficacy of endoscopic approaches to patients with hemodialysis-dependent concomitant with esophagogastric varices. Methods. Medical records were reviewed from January 1, 2004, to December 31, 2015, in our hospital. Five consecutive hemodialysis-dependent patients with variceal hemorrhage who underwent endoscopic treatments were retrospectively studied. Results. The median age of the patients was 54 years (range 34–67 years) and the median follow-up period was 21.3 months (range 7–134 months). All the patients received a total of three times heparin-free hemodialysis 24 hours before and no more than 24 hours and 72 hours after endoscopic treatment. They successfully had endoscopic variceal ligation, endoscopic injection sclerotherapy, and/or N-butyl cyanoacrylate injection. The short-term efficacy is satisfying and long-term follow-up showed episodes of rebleeding. Conclusions. Endoscopic approaches are the alternative options in the treatment of upper gastroenterology variceal hemorrhage in hemodialysis-dependent patients without severe complications
Experimental study on parametric configurations of artificially downwelling aerations in stratified water
Downwelling aeration has become a widely applied approach to cope with the water eutrophication in stratified reservoirs, rivers and lakes. The aeration parameters involving flow rate, flow locations and working periodicity and their impacts on the temperature and dissolved oxygen (DO) distributions of water have been largely unclarified, causing extra time and energy consumptions in practice. In this study, a home-built water tank and an aeration pump are used to model the downwelling aeration processes in stratified water. Temporal influences of aeration parameters on the water stratifications and eutrophicated elements are systemically investigated, with the purpose of searching parametric configurations to enhance the anti-eutrophication efficiency. It is found that the variation rates of temperature destratification and DO distribution in the water body could be saturated and strongly correlated with the flow rate. Based on such experimental saturation rates, we find an optimized working condition from the aspect of energy saving: a 300 rpm pump speed and a 15 cm distance between the flow exit and the sediment surface. In such conditions, the total nitrogen and phosphorus dissolved in the bottom layer of water decrease exponentially with aeration time, and can be reduced by 53.8 and 86% in the first 6 h of aerations, respectively, taking full advantage of the microbial bonding to the sedimentations. The present work provides better understandings for efficient implementations of downwelling aerations.publishedVersio
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