Selecting particular columns from large datasets (csv) using R Studio?

So I have large number of csv files (100+) in a directory with same structure and column names. The data is in time series and there are approx 30 columns/file. However i only want to aggregate...

08 February 2021 245 5 View

How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for Metabarcoding?

I'm working on pollen DNA metabarcoding to identify the floral composition of honey. How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for the...

28 December 2020 9,132 1 View

How to add two vertical and parallel Fresnel reflection coefficients to retrieve overall reflection coefficient for a right hand circular wave?

I have a problem in which a right hand circular polarized wave (GPS wave) encounters an ideal smooth plane obliquely, and then is reflected off that. To solve this kind of problems, the wave is...

28 December 2020 2,271 3 View

Which is better to focus on teaching or research for a good academic life and Why?

Which is better to focus on teaching or research for For a good academic life and Why?

26 December 2020 5,737 9 View

Is ag paste suitable for back contact on silicon wafer? or i should deposit al on the back surface using pvd or plasma sputtering?

Fabricating silicon solar cell

22 December 2020 4,906 7 View

Which renewable source is the best ?

wind hydro solar etc.

21 December 2020 6,360 16 View

Why is light pure energy?

light is pure because the light is the simplest electromagnetic construct but the energy of any object is also of the same kind.

20 December 2020 207 4 View

How to handle Missing Values for Skipped Questions (Systematic Missing) in R ?

10 December 2020 435 4 View

What is the best industrial emulsifier to make silicon oil in water emulsion?

I need to make long-lasting stable emulsions of 6 wt. % percent silicon oil in DI water. The previousely made emulsions using Tween and Span Emulsifiers did not remain stable after a week.

31 October 2020 3,568 3 View

Carbon Emission calculation factors ?

I am thinking about writing a paper on carbon emissions based on electricity consumption data from some buildings. From a research perspective, which factors should i specially focus while...

09 October 2020 4,142 3 View

Can we classify HV and LV lines based on line length?

I have dataset which shows the length of power lines. I need to classify the lines based on the line length. Is there a rule to classify the High voltage (HV) and low voltage (LV) lines based on...

03 March 2021 4,116 4 View

What analysis to choose with a large neste dataset and clearly skewed or kurtotic distributions?

Hello! I have a dataset of n=3000 nested within 8 countries with approximately 200 or 400 responses in each country. I originally planned to perform multilevel modelling with 4 dependent variables...

02 March 2021 6,865 1 View

I am interested in medicinal chemistry field, which books are highly recommended to learn from?

I am at the beginner level in drug design and drug discovery, and I am interested to learn more about this field. Which books are highly recommended to start from and gives me all essential...

02 March 2021 8,437 2 View

Do you know any MR image dataset?

I would like to research on MR images (0.5T and 3T). Can you please suggest some websites that I can download dataset including both 0.5T and 3T MR images? Thank you.

02 March 2021 7,735 3 View

Can NFL theorem be valid in infinite search space in ML?

NFL theorem is valid for algorithms training in fixed training set. However, the general characteristic of algorithms in expanded or open dataset has not been proved yet. Could you show your...

01 March 2021 1,189 3 View

Does anyone have kinetic and kinematic dataset for gait classification?

I want to differentiate between normal and abnormal movement. For this reason, I am looking forward to this type of dataset.

01 March 2021 9,485 1 View

Where can I find public datasets with Covid-19 patient information?

Hi, I'm looking for public datasets that have CT, X-ray information, or medical records for patients with Covid-19. Does anyone have suggestions?

28 February 2021 4,760 3 View

I need dataset for recommandation system?

Hi every body I need to collect datasets from different source to work on recommendation system algorithms, could you advise me how collect data?

27 February 2021 7,063 7 View

How to evaluate unsupervised clustering metrics when some elements do not have a cluster label in the result?

I run algorithms like HDBSCAN and MeanShift, and compare them with K-means and GaussianMixture. The first two algorithms do not return cluster labels for some elements in the dataset. My question...

27 February 2021 428 3 View

How to download dataset?

I have to download dataset from software infrastructure repository (SIR) and I have created account on repository but I am not able to download plz guide.

25 February 2021 3,840 2 View