Yang Pan

14 Questions 11 Answers 0 Followers

Questions related from Yang Pan

How to calculate the joint entropy of a large stochastic observation network?

For example, suppose I have an observation network consisting of 10,000 gauges. It is easy to calculate the joint (Shannon) entropy of these 10,000 gauges, if these points are all present at the...

01 January 2018 6,540 3 View

How will the response rate change in a survey with the increase of incentive?

It is well established that providing incentives (e.g., monetary incentive) can boost the participation rate of a survey or a campaign (e.g., asking citizens to measure and report the rainfall...

10 October 2017 4,392 3 View

What do you do if the Hessian Matrix is too much sensitive to the step size?

I am using Laplace Approximation to approach a distribution. To do this, I find the minimum of a function, which will be the mean of the target distribution. And the inverse of the Hessian Matrix...

09 September 2017 9,880 0 View

Is there any method to do hydrological extreme analysis using monthly flow data?

I wish to do some hydrological extreme analysis for my research. But applications of the most popular methods like Generlized Extreme Value (GEV), and Copula all seem to use daily flow data. Is...

04 April 2015 6,296 10 View

How do I add different degrees of nonstationarity into a monthly flow series?

One great influence of climate change on water resources system is the growing degree of nonstationarity of hydrological time series. Nonstationarity is a very broad word, trend, growing variance,...

01 January 2015 4,812 7 View

Why does the objective function of fuzzy c-means algorithm become NaN in Matlab?

I am using the Matlab Fuzzy Inference toolbox to build an adaptive neuro-fuzzy inference system. I first use genfis3 to generate a FIS system and do the clustering, then use anfis to further...

11 November 2014 3,336 6 View

How can I compare two time series forecasting models considering their uncertainty?

When comparing two time series forecasting models, there are many statistics, e.g., R2, RMSE, Nash efficiency, etc. However, they are all for deterministic models, when considering the uncertainty...

09 September 2014 6,404 7 View

How can I determine the possibility that one point in a time series is an extreme event, and also determine the duration of that event?

For example, in hydrology, for a monthly flow series, how can I determine the possibility that one point indicates an extreme high (or low) flow event, and the duration of that event?

09 September 2014 1,782 4 View

Why do data driven methods require large number of data?

It is generally agreed that data driven methods, e.g., ANN, ANFIS, requires large number of data if they are used to forecasting time series. However, I am not quite understand why. What are the...

09 September 2014 6,484 9 View

How can I make a forecast of series with certain probability distribution functions?

For example, if I have a probability distribution function (say a gamma function) of a series (say a daily streamflow series), and maybe I have a few other related data (say daily series of...

04 April 2014 6,885 1 View

Is there any database providing the flow velocity of each river globally?

I am quite interested in the flow velocity of each river globally. However, most of the data I found in global scale hydrological database provide only discharge data. Is there any chance I can...

11 November 2013 9,646 6 View

What is the difference between flow variability and hydrological disturbance?

In many papers these two concepts seems to be interchangeable. However, hydrological disturbance describes the discrete pulses of high or low flow while flow variability seems to be a measure of...

11 November 2013 4,915 4 View

Are there any models available to simulate the discharge and possibly water chemistry in a small headwater stream with high degree of slope?

Are there any models available to simulate the discharge and possibly water chemistry in a small headwater stream with high degree of slope? What are their data requirements?

10 October 2013 1,330 21 View

Are the identical time period and an equal length the required conditions to calculate and compare the periodicity of two time series?

If I calculate the period of one series (S1) as T1, and the other (S2) as T2, and then I calculate the ratio of T1 and T2. What is the deficits when S1 and S2 are not in the identical time period...

09 September 2013 8,452 7 View