Desired sample proportion/minimum sample size in each group if we want to compare them?

I need to conduct a study in which the treatment group has two levels, say A and B. The sizes of these groups are really different, size of group A is 1 million while the size of B is 20,000. I...

04 May 2019 7,657 22 View

What is the meaning of fractional difference parameter d in ARFIMA model?

I know that the series is stationary and has long memory property if the fractional parameter d is between 0 and 0.5. But is it for stationarity or for testing that the series has a long memory?...

04 May 2016 8,061 5 View

Why does long memory property common in financial and economic fields?

I've read articles, journals and books regarding long memory property of a time series data. And most of it found that, it is common in financial and economic perspective. I know , for example, in...

03 April 2016 4,756 7 View

Arfima forecast codes in R?

Hi, i just want to ask what is wrong with my codes that the forecast plot looks like in the attach file. The codes are these, > x ...

10 November 2015 9,765 0 View

How do I create power series expansion of long memory properties of time series?

Hi. I look at the journal of Hosking in proving the properties of ARFIMA (0,d,0). It says there, when d < 1/2, the power series expansion of (1-z)^(-d) converges for absolute value of z less...

10 November 2015 1,314 3 View

Topics for master's thesis?

Hi! i'm still confused of what problem in statistics should i consider to be included in my study. I want to find a topic for my thesis but i find it hard looking for it. can anyone suggests?

06 July 2015 6,238 5 View

Can I ask for a Randomization topic?

Can anyone give me a topic in statistics that might involve using randomization? just like the one sample test, anova, regression.. But this particular topics were already absorb in my class. So i...

02 March 2015 9,074 8 View

ARCH in R Software?

02 March 2015 9,232 1 View

Does anyone know about R codes for Spearman's correlation with randomization?

I am trying to do a randomization test in Spearman's correlation in R. And i find it difficult to do the randomization part.

02 March 2015 122 3 View

Can anyone explain to me the concept of exponential smoothing in time series?

I have read that it can be used in forecasting. so what is the difference of this method and the usual method in forecasting? And also, I don't understand the concept that this method assigns...

09 October 2014 2,093 5 View

How to compare two groups with only two measurements?

Hiiiii everyone! I have an enquiry on statistical analysis. I was looking for many forum and it's still cannot solve my problem. I want to compare means of two groups of data but only with two...

03 March 2021 8,796 3 View

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

After a reference from Int J Body Compos Res, can any body help?

Hi, I am after the reference below, my library says it cannot obtain a copy either locally or internationally, any help appreciated! Chris Wang ZM, Heshka S, Wielopolski L, Pi-Sunyer FX, Pierson...

03 March 2021 6,193 1 View

What techniques can I use to determine the miscibility of polymer blends?

The term miscibility refers to the single-phase state in thermodynamics. I do not mean the compatibility of different components. To determine the miscibility I know several techniques such as...

03 March 2021 4,107 4 View

How to normalise data on OPM package from R Studio ?

Good afternoon, I recently used OmniLog from BIOLOG for my experimentations : I tested the metabolism of different strains on 2 types of plates. I have 16 strains of 3 different groups...

02 March 2021 3,584 1 View

How to repeat an operation on an atom selection for multiple times in PyMol?

Hi, I am trying to construct a multi-layer fibril structure from a single layer in PyMol by translating the layer along the fibril axis. For now, I am able to use the Translate command in PyMol...

02 March 2021 4,569 4 View

How to calculate average trend in maximum annual NDVI from MODIS?

I am wanting to calculate the average trend in maximum annual NDVI in Iceland from 2010-2020 using MODIS MYD13Q1 V6. How would I do this? I have currently inserted the NDVI bands from the MODIS...

02 March 2021 752 2 View

Shall I skip the measurement model in SmartPLS?

Hello everyone, I had run a mediation model in SmartPLS using questionnaires that were already validated among my statistical population. A professor who edited my paper -though she is not...

01 March 2021 3,052 3 View

What is involved in morphological changes of SEM images of a substance?

In the sem analysis of CaCO3 nanaoparticles, the morphology images showed spherical shaped particles but the proposed morphology for these type of nanoparticles is trigonal. I prepared the...

01 March 2021 1,960 4 View

I have designed reflectarray element and feeding it though Horn Antenna on HFSS. After full wave simulation, I am not getting desired results?

I have designed reflectarray element to generate OAM beams at 5.8GHz and feeding it though Horn Antenna on HFSS. After full wave simulation, i am not getting desired results i.e Radiation pattern...

01 March 2021 9,701 5 View