Science topic

# Coherence - Science topic

Explore the latest questions and answers in Coherence, and find Coherence experts.

Questions related to Coherence

Dear Friend and colleagues please share your views on importance of coherence in leadership. How much it justify leadership personality. In absence of coherent approach what draw back leaders face.

Thanks & Regards

I want to make two coherent light sources in phase using one laser source. It can be done by using a beam splitter.

My Awesomest Network, I am starting my Ph.D. studies and I have some questions and doubts concerning it. Could I write them down here, please? First of them is how can I join disciplines as sociology, management, economics, mathematics, informatics and other similar items to make a complex holistic interdisciplinary analysis and coherent study of pointed fields. I think personally that linking or joining et cetera aspects of artificial intelligence and computational social sciences would be interesting area of considerations. What are Your opinions?

Thank You very much for all in advance

I work with an optical coherence tomography system. I want to detect the boundary between two features in an OCT image using a CNN. Kindly guide me to anyone who has done similar work or published work on this problem.

My Awesomest Network, I am starting my Ph.D. studies and I have some questions and doubts concerning it. Could I write them down here, pleaswe? First of them is how can I join disciplines as sociology, management, economics, mathematics, informatics and other similaer items to make a complex holistic interdisciplinary analysis and coherent study of pointed fields.

Thank You very much for all in advance

Hi everyone!

I'm looking for some exciting analysis methods for

**correlation, coherence, causality**, etc. that can be used for physiological signals (time series, particularly RR time series) obtained from two subjects.The case study that I consider is:

**is there any connection between the RR time interval series between a player on the instrument and the listener?**One of the methods that I want to use is the time-frequency coherence analysis by Orini et al. where I will take to input two RR time interval series (from the player and the listener).

What else can I use for this type of data? Do you have any recommendations?

I'm also interested in creating a

**connection network between players and listeners**using the RR time interval series obtained from participants during a music session. However, I don't know what measure for such a graph will be good. It will be nice to create a network like in the Ivanov et al. methodology https://www.nature.com/articles/ncomms1705, not within a body but between the participants. What do you think?Thank you for every suggestion.

An educational workspace could be a school, university, or any team that works in the education, or training field.

This question addresses particularly t the educational manager but meets also any manager's interests.

Once upon a time, while I attend training about leadership, my mentor said to me: you have to create a team. I thought that I had a team, replied, and he said you don't have a team, you need to build it. At that time, I don't really understand what he meant. And I should continue with a group of coworkers and never had a team. When the team doesn't exist you have to fight for anything as collaboration, outcomes at the right time, sharing experiences, etc After three years, in a new office, I became again a team manager, but I didn't especially create this team, but I think I consolidate the team that I inherited from the circumstances. Nevertheless, I think I gave a good contribution not as large as the executive management who had the power to decide whether to recruit or not the profile that I suggest, but it matters.

So, I would like to get others' experiences to compare and reinforce my experience at work; also writing a scientific article.

Coherence and correlation seem very similar to each other to me; while, coherence assesses similarity of the signals in frequency space rather than time space. I was wondering whether it is possible to employ coherence instead of correlation in Canonical Correlation Analysis.

I need an exemple of the wavelet coherence and cross spectrum please.

In text and linguistics, how coherence can be utilised fully? What are the advantages of coherence?

Hi guys,

I am using the negative log likelihood function of a drichilet distribution as my loss function while implementing this paper:

I parameterise the distribution using my network outcome and compute the negative log likelihood of the observed ground truth.

Issue is that I found sometimes the loss is negative, which means that likelihood at the point of observation is greater than 1.

My understanding of this phenomenon comes with two sets:

- This is normal, as likelihood function can be higher 1

- This stands for overfitting, means that the likelihood function probably peaks at the point of the observation so much that other areas of the support would be zero, if we throw an observation there to be test

Hello everyone. Some of us are not experts in psychology but we are interested in the subject and we want to have some basic ideas to help our students. I have some doubts about the similarities and differences between some concepts. I am referring to Dabrowsky's over-excitabilities, Aron's highly sensitive persons, the concept of giftedness itself and the aftermath of post-traumatic stress. There are experts who confuse these terms, deny the validity of some of them, consider them synonymous, etc... I would like to have a coherent explanation as to whether they are related aspects or whether some encompass others. Thank you very much.

Cold plasma is characterized by a thermal non-equilibrium between heavy particles (ions, meta stables, neutrals) and light particles (electrons),and is characterized by a low current discharge under atmospheric conditions, generated by application of high voltages.While the most common laser output characteristics include: wavelength, gain bandwidth, monochromatic, spatial and temporal profiles, collimation, output power, coherence and polarization.

Lasers are well known for their coherency. I was wondering to ask whether it is possible to make white light coherent? Of course, a long coherency length the same as lasers is not intended/expected but a coherence length of 10-30 cm.

Assuming there are TWO HeNe coherent laser sources one with LP and the other with Random polarizations (RP). l can see clear fringe pattern if LP light source pass through aligned-fringe pattern MZ interferometer (I had only a LP HeNe laser in my Lab). Is there any difference if take the coherent RP HeNe Laser source for doing the same MZ test? Why?

As being an amateur Quantum Optics researcher, I am looking for RG's help with comprehend a few questions re. my fiber Labs.

1. Assuming HeNe laser sources with LP and Random polarizations (RP), let such lights pass through aligned-fringe pattern interferometer (I had only done LP laser). Is there any difference in the TWO sources' output interference patterns? Why?

2. A LP free-space Laser source's MFD and waist get well aligned with a PM fiber coupler (slow axis is in vertical). How and why will the PM fiber coupling ratio (%) be varying with the different polarization incidence angles, e.g. Vertical, Horizontal and Diagonal?

What will be their output characteristics at the PM fiber output end in terms of polarization states?

3. To control a SM fiber output polarization, it can be done by using a fiber-stress type polarization controller. How if I can or cannot control a PM fiber output polarizations by using such controller?

4. How if a typical ED (Erbium-doped) fiber can be used as a CPA (coherent perfect absorber) for certain absorption Laser frequencies?

Or, if one can devise a ED fiber being the exact opposite of the laser process. In turn, make a design what we term a CPA. The ED fiber device perfectly absorbs incoming coherent laser light with given frequency and turns it into some form of internal energy — EM heat or energy.

We synthesized sin waves in matlab. One pair data are at same lower frequency and same lower power. The other pair are at same higher frequency and same higher power. There are

**high coherence**within both lower/higher frequency pair, because they are almost same in the each pair. But if I mix lower/higher frequency/power together and calculate coherence, the higher frequency showed high coherence, but the lower frequency showed**low coherence,**although the signal in lower freq should be very coherent! I feel something is wrong with power normalization.The attached is my matlab file. we used mscohere. BTW would wcoherence be different?

I was reading a paper introducing the Delayed Self-Heterodyne Interferometry technique by Okoshi in 1980. It was aimed to measure the linewidth of lasers and the main set-up was something like a Mach-Zehnder interferometer, but one of the arms was delayed by a fiber path much longer than the laser's coherence length, and there was an AOM in the other arm [I don't know if it's important]. The interference of these two beams was claimed to indicate the linewidth of the laser. What I do not understand is that how these uncorrelated beams do interfere?

Hi,

I'm interested in running periodic ab-initio simulations of a disordered alloy using Quantum Espresso. I noticed that in most recent publications disorder is usually introduced with the coherent potential method (CPA). However I am not really sure how CPA and QE can be coupled together to effectively run the simulations I want.

May I ask you if any of you have already used CPA and QE together and, if so, how can CPA be correctly incorporated in a usual QE routine?

Thanks in advance,

Best,

José

Hello researchers,

I have around 100 sentinel-1 SLC images. I want to compute coherence between the successive images (1->2, 2->3… and so on). For this, the conventional method is to read images 1 and 2, select swath, apply orbit files, coregister them using the back-geocoding operator, apply ESD and then compute the coherence and the same procedure is also with images 2 and 3, and so on.

I want to discuss another approach here

- Read image 1 and coregister all other images (2,3,4…100) with respect to 1.
- Now, for images 1 and 2, we can compute the coherence as the above-mentioned method.
- For image 2 slv and image 3 slv, we stack them together considering them already coregistered with image 1 and compute coherence.

I want to understand whether it is an ethical way to do it or not.

1. Can we assume in the case of SAR SLC product image 2 and image 3 are also coregistered when they are coregistered with image 1?

2. Do different incident angles affect the coregistration results?

3. Is there any effect of different range and azimuth pixel size?
4. What should be the optimal method to perform successive time series analysis?

Thanks

Dear all,

I conducted a mediation analysis with PROCESS obtaining the following results:

- path a (x on M): significant and negative. Coherent with my theory

- path b (M on Y): significant and positive. Coherent with my theory

- Path c and c': insignificants

Indirect effect: significant and negative.

Is it correct to comment on this result in terms of fully mediation? however, extensive literature defines mediations in which the coefficients of a and b have opposite signs (and/or in which the total effect is not significant) in terms of inconsistent mediation. Should I interpret my results in these Terms even if they are consistent with what I expect?

I have an EEG dataset that contains 62 databases of 27 subjects, recorded from 32 channels.

how can I compute coherence or correlation of channels (in whole of dataset)?

Does quantum coherence relate to one particle?

The Wavelet Coherence Approach has frequently been used in the time-series analysis. How can one apply this technique in MATLAB. Suggestions from expert users are highly appreciated.

If we apply atmospheric correction to the data to enhance the coherence, will it provide accurate deformation result in a densely vegetated mountainous region like the Himalayas.

I want to know the calculation for following paper. I am attaching the paper. Please help me

We are going to use the Heidelberg OCT Spectralis for mouse OCT acquisition. However, we find several papers reporting the use of this instrument for rodents, we are not able to successfully do it. We have two separate devices (1- Heidelberg OCT Spectralis and 2- Heidelberg Hra 2). The Heidelberg OCT Spectralis has two lenses one 30° Standard Objective Lens and an Anterior Segment lens. The Heidelberg Hra 2 has 55° widefield lens. unfortunately, the 55° lens could not be assembled to Heidelberg OCT Spectralis.

As far as we know, given the high dioptre of the mouse eye, we should use the 55° widefield lens. However, using the standard 30° we get a rather acceptable cSLO image, no OCT image is displayed.

Can anyone help solve this problem? We already tried using an additional lens in front of the device lens but still not working, however, maybe the total dioptre of the lens was not enough.

Also, a paper suggests minor software modifications (using Alt+Ctrl+Shift+O in Heidelberg Eye Explorer software) which we could not figure out how that should be done. (Spectral domain optical coherence tomography in mouse models of retinal degeneration. Invest Ophthalmol Vis Sci. 2009 Dec;50(12):5888-95. doi: 10.1167/iovs.09-3724.)

These are some papers about using the Heidelberg OCT Spectralis for rodents:

1- Quantitative Analysis of Mouse Retinal Layers Using Automated Segmentation of Spectral Domain Optical Coherence Tomography Images.

*Trans. Vis. Sci. Tech.*2015;4(4):9. doi: https://doi.org/10.1167/tvst.4.4.9.2- Tracking Longitudinal Retinal Changes in Experimental Ocular Hypertension Using the cSLO and Spectral Domain-OCT.

*Invest. Ophthalmol. Vis. Sci.*2010;51(12):6504-6513. doi: https://doi.org/10.1167/iovs.10-5551.3- Giannakaki-Zimmermann H, Kokona D, Wolf S, Ebneter A, Zinkernagel MS. Optical Coherence Tomography Angiography in Mice: Comparison with Confocal Scanning Laser Microscopy and Fluorescein Angiography. Transl Vis Sci Technol. 2016 Aug 18;5(4):11. doi: 10.1167/tvst.5.4.11. PMID: 27570710; PMCID: PMC4997887.

I normally use the SLC data of sentinel 1 data for calculation of repeat pass coherence. Is there any platform to access InSAR repeat pass Coherence data without needing the original SLC data?

It is well known that femtosecond CARS signal can be further enhanced when the condition of electronic resonance with the involved probe pulse is satisfied. Where can I find the relevant formula that quantitatively describe the ehancement ?

The interaction between a two-level system and a coherent field without a cavity does not produce the so-called "collapse and revival". Why?

Globally, air shed management and planning has resulted in viable and constructive solutions to address urban air pollution. Real time monitoring of air pollution based on the data pertaining to the part of the atmosphere that behaves in a coherent manner with respect to dispersion of emission might be critical to comprehend the air quality of a place. I would like to invite a discussion on this aspect of pollutant dispersion.

I started working on coherence and entanglement. At a point, I became confused between the concepts of entanglement and coherence where an author texted it the same however, they are still considered different by many authors. If anyone can explain, please answer this

The detection was of uv-vis thru a traditional double convex (glass) lens.

Can a parabolic reflecting lens focus and detect RF with this same coating, or stereoscopically 2 parabolics, with sufficient amplification ?

Detection of uv-vis with these metals of low work function is by the photoelectric effect.

But what was the phenomena of Marconi's transatlantic detection of RF (and its associated keyed Morse CODE) by the silver nickel powder "coherer" in the circuit?

Are there electrical component specifications for the coherer (V, I, R). The electrical schematic produced by Google searches shows a DC circuit with an Antenna symbol and other recognizable elements, but the "coherer" is not symbolized but is a 2D sketch of what it actually looked like.

Note: The lay word for parabolic is "dish".

In GP practice, a balance has to be found between limited time and enabling sufficient mutual understanding. One criterion could be the practitioner's feeling of having understood the subjective logic (world view) of the counterpart. What do we know about such a feeling of practitioners?

I read a paper address that "The effect of elastic strain energy is neglected in the model since the precipitation of sigma phase is simulated only in base metals where there is no coherency between austenite/ferrite." I don't understand this, how can we know whether there is coherency between phases? thanks for your answering

Dear all,

I am performing Wavelet Coherence analysis using R package biwavelet. But as soon as I run the command

**wtc.t1t2=wtc(t1, t2, nrands=100),**I am getting error:**Error in arima(d2[, 2], order = c(1, 0, 0)) : non-stationary AR part from CSS.****1.**Need guidance to get rid of this error.

**2**. Is there any limit to the number of observations in the series? (in the above command t1 and t2 have 43 observations each)

In a large cohort with MVP comprehensively characterized, MAD at MVP diagnosis was frequent, strongly linked to advanced-myxomatous-degeneration and independently associated with long-term excess-incidence of clinical arrhythmic events.

What is your own experience ? Does your daily practice is coherent with 30% of MAD in MVP? Did you diagnosed MAD without MVP ?

I am trying to investigate the coherence between two shoulder muscles at 0 - 90Hz. Precious studies used various cuff-off for their band pass filter, e.g. 1–400 Hz(Chen, 2012), 5-300Hz(Boonstra,2008), 3-1000Hz (Kattla, 2010). How do I determine the most appropriate filter for my analysis?

Also, we measured both surface and intramuscular EMG, but some intramuscular EMG signal are not good. Is it acceptable if I downsample the intramuscular EMG of one muscle, and calculate the coherence between it and the surface EMG of another muscle?

Thank you!!

I want to impute my data set in R by hmisc method, but I am failed as it is not recognizing my file and any command I am applying to impute the data, as I want to impute the whole data set as soon as possible. Is there any easy way for that?

For thin-film interference, the pulse duration is too short that the a part of the light can't meet the other part due to round-trip delay. In other word, part 1 can't reach the top surface part 2 while it's still lasting at the top surface within the source-on duration.

So if the chopper cut the CW light into pieces and changes the spectrum to a wider spectrum, will that mean temporal coherent length is relevant to pulse duration?

In File 7 of ENDF thermal scattering sublibrary, the coherent elastic cross sections of solid polycrystals are all for powdered samples.

Texture in the solid samples will affect the Bragg scattering cross sections. The structural materials in reactors are not powdered samples. I wonder is it reasonable to use the coherent elastic scattering cross section for the powdered polycrystal in the simulation of reactors?

How to define coherent "limits" of technology´s in AI ?

What is your experience about a more effective aid to teaching university students. Some people believe that PPTs help promote focus and coherence of thoughts of the teacher, others feel that the use of blackboard draws better attention of the audience. Of course, we presume that other things are the same in both cases e.g.competence of the teacher/facilitator, relevance of the contents, infrastructure, and motivation level of the students, etc.

I now explore three pedagogical strategies to improve junior high school students' skills in ESL academic writing. The main things I set up now are: lexical resources, grammatical range and accuracy, and coherence and cohesion. Do you think it works? Do you have any better suggestions for me?Thanks！

Why fiber rotator is needed in optical coherence tomography system? Currently I'm building a endoscopic OCT system from scratch and the fiber rotator will be used in the sample arm. Since I'm a newcomer in this area, could anybody offer an explanation for this device?

Thank you.

I'm looking for some kind of study, maybe a survey, that looks at where researchers started their work in terms of ideas and where they ended before publishing it. This could be an idea that they had or a reference that inspired them. It is my belief that researchers often try to tie their initial ideas to their innovative findings in a coherent train of thought before publishing it. But it is also possible that the innovation may have nothing to do with what they started. I wish to check if there is a statistical study on this matter, but I'm not sure what keywords would help me find such a study.

Working on chandrayaan-2 DFSAR data, there are three datasets available:

1) Slant range image data product: The slant range complex image file. Each pixel is represented by two 4-byte floating point value (one 4-byte floating point real and one 4-byte floating point imaginary value). Each pixel in the slant range image is Seleno-tagged with a lat./lon. value.

2) Ground range image data product: The ground range unsigned short int image file. Each pixel is represented by 2-byte unsigned short int. Each pixel in the slant range image is Seleno-tagged with a lat./lon. value.

3) Seleno-referenced image data product: The Map projected image file. Each pixel is represented by 2-byte unsigned short int file(amplitude).

Which should I be using if i want to generate coherency matrix and perform target decomposition?

Thanks in advance!

I am working in wavelet coherence analysis of two variables and I have plotted the wavelet coherence spectrum. But I wanted to find the phase lag and correlation coefficient for different time periods like 2, 2-4, 4-8,8-16, 116-32. Basically I wanted to decompose the wavelet into different time scales. I am using MATLAB for the analysis and I am pretty new in MATLAB coding. Please help me to find a solution.

Hello,

I am doing SIMULATION of TURBULENT PREMIXED FLAMES of CH4/NH3/air in Ansys Fluent. I am using the following:

Partially Premixed Combustion Model; Chemical Equilibrium; Extended Coherent Flame Model; Energy Eq on; Viscous k-e;

I wanted to try with Flamelet Generated Manifold but don't have CHEMKIN Files for this mixture of fuel.

I have Laminar burning velocity from measurements but don't know where to put it? also equivalence ratio (0.9); In Properties Tab of Species Model Fluent is calculating Laminar Flame Speed - how?

Boundary conditions: velocity: 0.41607m/s; Turb Intensity: 16.64%

Please help!

We calculate coherence as the degree of first-order coherence, defined in Eq. 6, Dudley et al., Rev. Mod. Phys. 78, (2006), where input pulse shot-noise is modeled semi-classically through the addition of a noise seed of one photon per mode. From this model, we expect that the coherence depends on the repetition rate, and the coherence will be higher for a high repetition rate. Is that true from a physical point of view?

Professor Selleri's book "The weak relativity" represents the summary of 20 years of research on the physics of space and time. The research path is clear, the arguments are solid, the logic is evident, the content is revolutionary. If the topics expressed in this book are "true" physics would be completely reversed, the SR and the GR should be abandoned, with all their consequences, such as the Big Bang, dark matter etc .. Yet 9 years after its publication, no one has been able to reasonably contrast Selleri's ideas and in the same way no one has thought it necessary to rethink the physics of space and time .......

Either his ideas are refuted in a coherent and rational way or the physics of space and time must be completely re-founded, there is no alternative in the scientific method, indifference is not an option

Is there someone who has a research paper?

Preferably for frequencies around 700 Mhz, 868 Mhz, 900 Mhz.

Do we have any research that scientifically, rigorously or with some level of objectivity measure the structural logic of policies? Or is there anyway measure we use to say that this is a coherent, consistent, congruent policy with integrity (the content)? Or in another way, are there any existing measures one can use to measure the evolution of a policy's causal logic over time?

The existing measure is it also used as an indicator for the potential success of a policy?

Thank you so much

We are measuring spectra using Thorlabs OSA which also provides the interferogram signal. We would like to retrieve information about the pulse in the time domain and the pulse coherence.

Small Ag precipitate has a coherent interface with Cu, the large one has a semi-coherent interface.

I want to find the cross-correlation of the three time series i.e., SST, SSS, and NINO4. Two of those (SST & SSS) have a strong seasonality and the rest one has an interannual cycle. How should I deal with those 3 to find the correlation?

We have conducted an AHP (analytic hierarchy process) to understand experts' opinions of the relative importance of different aspects of natural resource management, specifically for fisheries governance.

From our data, it appears group coherency is low - all our experts have every different opinion about what components of governance are important in the situation we proposed to them.

To confirm this, we want to compute a measure of group coherence as described by Zahir in two papers in 1999. However, this calculation is beyond my statistical abilities. Does anyone have any guide, or ideally code (Python, R script) to calculate this statistic?

Zahir S (1999a). Clusters in a group: Decision making in the vector space formulation of the analytic hierarchy process. European Journal of Operational Research 112: 620-634.

Zahir S (1999b). Geometry of decision making and the vector space formulation of the analytic hierarchy process. European Journal of Operational Research 112: 373-396.

I have recently begun doctoral research in the field of laser speckle suppression. I want to simulate this effect to provide proof of concept. However, I have no idea where to start. Does anybody have advice on this?

When particle size (5um) is greater than the incident wavelength (0.55um) the Mie scattering occurs.The forward scattered light is stronger than the back-scattered light. In literature, it is mentioned that the forward scattered light is exactly in-phase, regardless of separation of dipoles. this is not true for any other direction. The back-scattered light is out of phase.

So, my question is, why forward scattered light is in-phase and back-scattered light is out of phase? If we consider scattering by dipoles, in general the scattering by dipole is coherent. The forward and back-scattered light should be same.

Can anyone explain according to physics (without mathematics) ?

Your cooperation will be highly appreciated. Thanks in advance.

I'm trying to check the coherence between a high frequency data and a low frequency data using wavelet.. Is it supported or do I need to convert them to the same nature ..

There are, of course (correspondingly), "idiotic" Questions. And ridiculous speculations by-analogy (and by-analogy is always suspect). (An example of "Answers" by foundation-less and link-less analogy is " 'quantum' explanations" to several psychological things; it is a bad joke any such person could have a graduate degree !) Sorry: my perception of common things here on RG. And, after years of nonsense, I have decided to state my observation.

It is likely very nearly pointless that I am here on RG (and there have been only so many years I have been able to try to fool myself).

Dear research community.

Can anyone recommend a reasonably priced type of neurofeedback equipment for coherence or ratio training in frontal/midline areas? I am looking for equipment for a pilot-project on children/adolescents and have a very limited budget so want an approach that can give results without needing full LoRETA resolution.

Let's say I am simulating as simple as BFSK, it has two symbols one entirely on the real plane while other on the complex plane for representing let's say zero and one, that is how the constellation of BFSK looks like.

**s=data + j*(~data);**%Baseband BFSK modulationNow let's say we added AWGN (N) and Rayleigh fading (h) as well.

**Rx= h*x + N;**Now when I tried to detect it on the receiving side I will have to divide this entire**Rx**by an h, well that makes sense. My entire graphs for the**BER**curve match non-coherent detection for FSK. It exactly matched the theory,**Eb/N0 vs. BER for BFSK over Rayleigh Channel**.**Now how to do the same for Non-coherent detection?**If I do not divide Rx by h**Rx/h**, I get a few very very bad results and that doesn't match anything. Theory tells us that In non-coherent detection, prior knowledge of the channel impulse response is not known at the receiver.In Coherent systems, the receiver needs

**phase information**of the transmitter (the carrier phase) to recover the transmitted data at the receiver side. I haven't used any such thing but still simulation results for BER matched with that of theory for Coherent FSK.Can someone here help me with this? By not diving by

**h,**will I get better results for**Non coherent FSK ?**Whether**BPSK or BFSK**every time we need to divide h*x + N by an h for getting results that match theory.How can we identify the precipitate /matrix relationship (coherent/incoherent) from coffee bean contrast observed in the precipitates.

As we face a digital era that connects researchers and researches from around the world there is a tremendous amount of works available for new researchers and their projects and works. Are there any methods, tools, strategies that can improve the bibliographical research stage?

I want to write a code to generate coherency volume to detect faults in the data . For that I want literatures to find algorithm and concepts or any type of help in this regard.Thank you .

I have to calculete coherence two image , code 'ms cohere' in appropriate for vectors.

What type of PCF is ideal for coherent SC generation for carrier envelope offset measurement of a modelocked laser. As far as I know, for coherent SC generation, PCF should be pumped in normal dispersion regime. Moreover, PCF should have ZD (zero dispersion wavelength) close to pump wavelength. Are there any other conditions to consider. Plz advice.

I'm currently working on a topic modeling project and want to determine the number of latent topics in the dataset. I've recently discovered the UMass coherence score as a suitable proxy. The issue is that I don't know how to calculate it in Stata. Does anyone know an easy way to calculate it in Stata or another program that is easy to use? I've tried to use Mallet without success.

Ionospheric radar it can generate 2D image forming technique my the linear rectangular array Ionosphere radar are recently established at Gadanki (13.5°N, 79.2°E; 6.5°N magnetic latitude) in this Radar is operated in the frequency range 30MHz operation in this are used to finding in the atmospheric layer characteristics coherently Radar imaging technique I have generates In phase and quarter phase IQ data of the Each range bin and each height of the radar and it takes the visibility matrix of each height and each time of NFFT points how is it generates an image of each receiver visibility matrix are to be multiplied are not to the weighing vector

plese give me the solution of this work this RAW DATA are 5 channel receiver database papers of the following are their

The widely used formula for determination of penetration depth from lower critical field is

Hc1 = φln(k)/4πλ^2

which is valid for k>>1, Can anyone help how to find the λ for k~1 material. The mentioned formula does not give any result as the Hc1 4π λ^2 vs λ and φln(k) vs λ curves do not intersect. I know the coherence length from Hc2.