Muhamad Khairulbahri

60 Questions 68 Answers 0 Followers

Questions related from Muhamad Khairulbahri

Are there rules to estimate the hotel (camping sites and apartment) size (in feet square or ha)?

I have data about the number of rooms in different accommodation types such as hotels, apartments and camping sites. I need to know the land size taken by different accommodation types based on...

25 April 2019 4,935 2 View

Could you forward to me some papers about required energy to support water supply in Spain?

I want to measure energy consumption after water is discharged from groundwater, energy consumption after water is distributed from aquifers to end users. Especially in Mediterranean Spain or...

14 September 2018 2,716 2 View

How do I assess data accuracy ?

I have climate data such as rainfall and another data such as aquifer volume. I want to assess whether all of this data is credible without any errors such as systematic error. What statistical...

08 August 2018 4,687 3 View

In the context of aquifers/ groundwater, what do "dynamic reserve" and "spring source (drenajes manantiales y fuentes)" mean?

I am learning about aquifers and have found some acronyms such dynamic reserve and "drenajes manantiales y fuentes" (spring sources?. Can someone explain the meanings of these acronyms? And also,...

04 June 2018 6,841 8 View

Is that true saying the global water supply is sufficient to fulfill the global water demand ?

I have read a statement that the global water supply is sufficient to fulfill the global water demand. But papers I have read did not mention the source(s). Can someone help me any sources of...

23 May 2018 2,994 4 View

Is there a delay between water infiltration to aquifers (groundwater)?

I want to know whether there is a delay between infiltration of surface water and precipitation to aquifers (groundwater). If so, please suggest how much time is needed ? Again, if Groundwater...

27 April 2018 5,865 28 View

Is that enough to use rainfall and temperature to measure the effects of climate change on rice yield?

Most studies usually estimate the impacts of climate change on rice yield using temperature and rainfall as predictors. Why most studies do not consider the effects of humidity and wind speed on...

18 May 2017 935 7 View

How do we read or analyse figures in AR5 WG1 Chapter 12 (figure 12.22) ?

The IPCC compare the multi-model mean change with internal variability, and indicate where the former is greater than the latter by one and two standard deviations. For example figure 12.22 in...

07 May 2017 8,527 6 View

Are there papers explaining about supply-driven chains and demand-drive chains?

There are categories of supply chain such as supply-driven chains and demand-driven chains. Please give me best books and papers explaining this issue.

28 April 2017 3,607 5 View

Can I collect historical data of rainfall from knmi.nl ?

I want to historical data from knmi.nl

28 April 2017 1,111 4 View

In what situation I should combine univariate and multivariate analysis?

I want to develop statistical models with some independent variables.

05 April 2017 4,547 7 View

Can someone suggest handbook(s) that explain ALL classes of statistical models ?

Can someone suggest handbook(s) that explainclasses of statistical models like in this link...

03 April 2017 1,399 3 View

I want to estimate a regression model in the field of agriculture. Shall I conduct correlation analysis prior to regression analysis?

I want to estimate a regression model in the field of agriculture. Shall I conduct correlation analysis (the first difference correlation as some data are not stationary). I shall conduct...

12 October 2016 7,193 14 View

Does it mean two rice features i.e high yield and short duration cannot be separated to achieve high rice production ?

I have read about the green revolution during 1980s.It seems to me that short duration growth and high yielding are needed and should be combinedto get higher rice productions. Does it mean two...

15 September 2016 2,800 3 View

Do traits relate to heat tolerant and traits relate to high yielding having reversed acts?

I need to know whether traits relate to heat tolerance (HT) in rice and traits relate to high yielding (HY) are contradict each other ? For example, traits to HT tend to close stomata while traits...

06 September 2016 4,849 1 View

Are there any indicator(s) than RMSE to assess the bias corrected climate outputs?

I have been corrected some climate outputs. What are possible indicators other than RMSE (or other biased errors) ? Are there any qualitative indicators ?

12 July 2016 7,850 9 View

Are there any gauge to set the constant price ?

I have some variable (time series) of production factors in monetary values and I want analyze them as variables at constant price. Are there any gauges to choose a specific year as the price...

04 July 2016 5,968 28 View

Why did I get different results after root tests ?

I have a variable named A. Let's name a residual of A = time + c is B. I conducted a root test and found that B is stationary. In another time, I conducted a root test of A with a setting of...

30 June 2016 3,843 7 View

If all variables are stationary in the 1st difference shall I conduct a cointegration test ?

I want to estimate an equation Y = ax1 + bx2 + time trend + c. After root tests, I found that all variables are stationary in 1st difference, and then shall I conduct a cointegration test ? if...

30 June 2016 7,273 22 View

I want to estimate the impacts of future climate on crop yield. What are reasons to use climate output at nearest grid point instead of downscaling ?

I need future climate output, what I have is only climate output at nearest point. What are justifications to use climate series at nearest grid point instead of downscaling GCM output ? After...

23 May 2016 4,197 21 View

In what situations I can use climate output at nearest grid point instead of down scaled output?

I want to estimate the impacts of climate change on crop yield by 2100. Can I use climate output at nearest point instead of downscaled output ?

17 May 2016 8,579 2 View

Shall I transform non-stationary to be stationary prior to correlation analysis?

I have data of production factors and climate. I want assess correlations between them. As data shows non-stationary, shall I detrending or differencing data prior to correlation analysis?

16 May 2016 106 4 View

Are projected temperature and/or projected rainfall in RCP2.6 and RCP4.5 has a similar value ?

I made projected temperature on rainfall in three interval: 2030; 2060; 2090. Do any projected temperature/rainfall by 2030 should have a similar value for RCP2.6 and RCP4.5 scenarios?

07 April 2016 7,026 3 View

How do I conduct stationary tests if there are any structural break(s) ?

I have sample from 1976 until 2011. But, literature says possible a structural break around 1996. What shall I do to conduct stationary tests under a structural break ?

14 March 2016 4,978 4 View

How I do use models with ar(1) to predict ?

I apply ar(1) as my regressor to prevent autocorrelation using Eviews. How do I predict future output using this model (I have a quadratic regressor) ? After I added ar(1), 1 regressor changed...

17 November 2015 5,320 16 View

Why is transformation to sqrt better than log-linear transformation ?

So, I have a linear-quadratic model that might not be good to do forecasting. So, I transform my model to log-linear etc but the transformed model is not good (violations of...

14 November 2015 4,546 5 View

How do I prevent negative trends of technological progress ?

I am estimating the impacts of climate on crop productivity. Y= (0.1272*time - 0.00424*time^2) - 0.09*temperature + constant "(0.1272*time - 0.00424*time^2)" is a representation of technological...

13 November 2015 671 9 View

How do I set time variables in estimating crop yields ?

Based on observed data 1976-2011, I got a model to estimate crop productivity like: Y= 0.18*time - 0.005*time^2 + 0.15*temp + 2.33. and then I want to estimate the impacts of climate change (high...

04 November 2015 8,331 8 View

What are the differences between technological progress, technological efficiency and TPF ?

Is that possible that technological progress, technical efficiency or TPF has a negative growth ? If I say that better crop varieties as technical efficiency (same input but better output) and...

02 November 2015 2,563 11 View

What available heteroscedasticity tests for non linear models?

My models have a squared time variable as a regressor. What available heteroscedasticity test(s) in this situation ? Why heteroscedasticity is more dangerous for non linear models than linear models

01 November 2015 7,165 3 View

How do I set time variables as an independent variables ?

Some papers written by Naylor, Lobell are using time variables as an independent variables. Let's say I obtain a model from observed data 1961-1990 such Y = a*time+a*time^2+c*temperature. Time and...

30 October 2015 9,615 5 View

How do we do sensitivity analysis of climate change impacts using a system dynamics model?

What I am asking for is sensitivity analysis in this thesis (see attached link). In page 265 of the thesis you can find a paragraph "The magnitude of the change was measured by comparing the...

22 October 2015 9,129 2 View

How do we model three planting season crops in a system dynamics model?

So, a crop has three planting seasons. Assuming, crops planted in three seasons have the same growing day. How do I model aggregated crop production (aggregating crop production in three seasons...

20 October 2015 8,657 2 View

Does anyone know appropriate methods to estimate dry spells in the future ?

I want to estimate dry spells in future. Please explain any appropriate methods to estimate dry spell in two cases: available observed climate and unavailable observed climate

18 September 2015 5,270 4 View

Is it possible that rainfall standard deviation changed but rainfall mean remained unchanged?

I separate climatic data (min temp, max temp and rainfall) into two periods (the first period is 30 year data and the second one is 20 year data). After statistical tests, I found that rainfall...

09 September 2015 9,366 8 View

Some say that non-parametric models such as neural network, spline do not allow us to extrapolate away from sample. Is that true ?

Some say that non-parametric models do not allow us to extrapolate away from samples. Let's say, I have a sample range 2.5 - 7.5. and I obtain a non-parametric models from this sample. Can I...

01 September 2015 4,103 3 View

I have seen that statistical models analysing the impacts of climate change on crop yields apply linear and quadratic time variables; why?

Statistical models usually employ a linear time variable and a squared time variable. I mean why the models do not include triple-squared time variables ? What are any reasons applying squared...

24 August 2015 1,113 4 View

Are there free contour maps to estimate the impact of sea level rise on any specific region?

I want to assess the impacts of sea level rise in an Indonesian province. In particular, I want to estimate inundated area due to sea level rise between 0 - 2 meters. Is that possible to get free...

18 March 2015 7,603 4 View

What are the advantages and disadvantages for using predictors of unit term or predictors of monetary terms ?

I want to regress ln Q = constant + alpha ln K + beta ln L. Let's say, I have all data types such that capital and labour are in terms of unit and monetary terms. What are advantages using...

11 March 2015 1,766 7 View

How do I convert the equation cln A+ aln K+b* ln L+intercept into a cobb-douglas function?

After regressing historical data, I got an equation c*ln A+ a*ln K+b* ln L+error, where A = technological change, K=kapital and L=labour. How do I change this equation to a general Cobb-Douglas...

09 March 2015 3,128 8 View

I want to do Shapiro tests before doing climate change detection. Shall I employ the Shapiro test for each period (the baseline and current period)?

To conduct climate change detection, I will separate some climate data into 2 periods: the baseline and the current period. Say, climate data will grouped into the baseline period and the recent...

05 March 2015 353 4 View

Using NCSS, I do regression analysis to prevent multi collinearity. What shall I do, using NCSS, to get a model without an intercept ?

I do ridge regression using NCSS software to prevent multicollinearity. But, the output of NCSS is with an intercept. What shall I do to get a model without an intercept ?

11 February 2015 7,243 3 View

How do I set parameter values for the base case scenario for SD modelling?

I am composing a system dynamics model. Historical data shows that some variables (inputs) has fluctuated values. How do I set parameter values for the base case scenario ?

10 February 2015 9,247 5 View

I have a production function as follows: Y=-9.5K+3K^2+6L-4L^2 Where K^2 = capital square L^2=labour square. Is this labor or capital intensive ?

K is capital and L = labour

24 January 2015 7,455 8 View

I want to detect climate change and assess impacts of climate on a crop. Shall I collect climate data from all rainfall stations or from 1 station ?

climate change climatologist agriculture climate change adaptation

14 November 2014 6,886 6 View

How can I estimate the monsoon onset and monsoon onset delay with just monthly rainfall data?

See above

31 October 2014 4,123 6 View

What is the impact of sea level using QGIS?

I want to measure the impact of sea level rise using QGIS. I have a map (DEM) and qgis. Anyone can give me a short lecture?

19 August 2014 996 4 View

I want to read future climate from worldclim datasets (www.worldclim.org). Does anyone know how to read these datasets using Quantum GIS?

The datasets from worldclim contain projections of minimum, maximum temperature and precipitation. Anyone know how to read these datasets using Quantum GIS (QGIS)?

29 May 2014 714 8 View

What are available methods to measure wetland loss due to rise in sea level?

I want predict the land loss due to the rise in sea level. I need to know available methods, required data and related issues.

21 May 2014 3,734 4 View

Are there any differences between higher precipitation and intense precipitation ?

Please provide some relevant academic papers.

27 March 2014 6,077 2 View

How should I get the climate for the region using NetCDF?

After I look at NetCDF file, the coordination of the region I want to study is overlapped. Let's say the region is located between 110.25 latitude and 115.50 latitude, but the available NetCDF...

27 March 2014 4,755 5 View

Can someone advise on the use of statistical models to estimate impacts of climate change?

In several papers (by Lobell, Shlenker etc)..we can estimate impacts of climate change on crop yields using statistical analysis like: Y= A.temp+B.temp(square)+C....

22 January 2014 1,496 3 View

Can some help with estimating climate change and climate variability impact on crops?

I need to know why I should use daily or monthly data. Why some use daily rainfall instead of monthly rainfall? Why others use monthly rainfall instead of daily rainfall?

01 January 2014 2,077 4 View

How can I download data CMIP 5?

I went to some websites such as NOAA / PCMDI and other similar websites, but I don't know how to find relevant data and download it.

01 September 2013 9,023 5 View

Anyone know how to measure hazard, vulnerability, risks, CDF and exposure due to climate change ?

I need to know how adaptable a community to climate change, so I need to understand how to measure values of vulnerability, risks, hazard, CDF and exposures.

11 July 2013 7,343 3 View

How many supply chains shall have Key Performance Indexes?

I want to measure performance of rice supply chain and I'm wondering how many key performance indexes I shall use to evaluate it?

24 June 2013 9,114 1 View

What are available methods to estimate previous climate data? How about validation methods?

As there is no historical climate data in intended regions, I want to estimate previous climate data.

24 June 2013 8,743 4 View

I'm interested to use system dynamics modeling to estimate climate change impacts on rice yield. Anyone has advice ?

Existing papers using system dynamics modelling to estimate climate change impacts on rice yield.

04 June 2013 3,152 3 View

Which is better, crop models or ricardian model?

I want to measure climate change impacts on rice yield. Which is the best method, ricardian method or crop models?

04 June 2013 5,652 3 View

Which is the best statistical or dynamical downscaling?

I need some climate variables (due to climate change) to estimate climate change impacts in agriculture (rice) yield.

31 May 2013 2,774 10 View