ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

Browse by research topic to find out what others in your field are discussing.

Browse Topics

  • Mohamed Kamel asked a question in Prone Position:
    Any one has experience with prone position and posterior thoracotomy ?

    Huge mediastinal mass with prior sternotomy for CABG

  • John Sosa added an answer in Object Tracking:
    Can you please help me with particle filter matlab coding for object tracking?


    please anyone has matlab code of particle filter so that can pass it to me. I still, there are some ideas that I can not get it even I had gotten one code for it, I still have confusing about it, as I can not make it working.

    Any help please?

    Thank you.

    John Sosa

    I may not be able to offer you code, but if you are able to post an example image, I'd be happy to make you a recipe file in our very powerful and user friendly software MIPAR at http://MIPAR.us. This could at least be helpful to you in learning the algorithm such that you could code it yourself. MIPAR is actually written in MATLAB (but runs standalone without the user needing MATLAB), so I may also be able to help write some code based on what we learn from the recipe creation. Best of luck!



  • Ali Syed Mithun asked a question in Stochastic Optimization:
    How can we differentiate among `Randomness`, `Uncertainty`, and `Stochasticity`?

    Operational research, probability, stochastic optimization, stochastic process, probabilistic scenario.

  • Netra Pal Singh added an answer in Mobile Computing:
    Are you aware of sufficiency strategies for sustainability in mobile ICT devices?

    In Germany this year the market for smartphones grows faster than expected. Total revenues for 2015 increase by 7 per cent to 9.1 billion Euro (bitkom.org, 10.08.2015)

    The total energy consumption of ICT is growing rapidly. Reduction of energy consumption is fine, but efficiency strategies alone have not led to a more sustainable situation. The following formula has been proposed for sustainable ICT

    Efficiency + Sufficiency = Innovation for Sustainability (Hilty et al. 2011)

    In mobile computing, the capacity of batteries in terms of energy density (energy/mass) is limited (DOI:10.5167/uzh-55640). This can be seen as an effective limitation (sufficiency), enabling more sustainable ICT innovations.

    Besides energy consumption, scarce natural resources are part of every smartphone. The growing demand for mobile ICT devices results in an increase in product offerings, usually sustained through a shorter service life leading to a faster exchange of your smartphone.

    Sufficiency strategies appear appealing to reach more sustainable consumption of ICT. Please share further examples of sustainable consumption of ICT, these can be driven by users, e.g. only use particular applications sundays, or driven by ICT design. I'm particularly interested in the interplay between user practices and ICT solutions for sustainability.

    Are you aware of sufficiency strategies for sustainability in mobile ICT devices (like smartphones)?

    Netra Pal Singh

    Yes I agree with many answer. This is true with respect to other technologies also. You provide an OS on smartphone devices with lots of features and size and then it start crashing after six month. Customer did not get any support from vendor and left with no option but run in the market. It will be better for vendor to reduce many apps icons and add one with title as "we are fixing software problems" be it OS or apps. In my view it will be sufficiency.

    N P Singh

  • Mohamed Kamel added an answer in Thoracic Surgery:
    Anyone with experience on a recurrence of leiomyosarcoma in the mediastinum?

    Thoracic surgery.

    Mohamed Kamel

    If localized do resection followed by CCTRH

  • David R. Themens added an answer in Earth:
    What are the boundaries of the ionosphere?

    The Earth's ionosphere is a region of Earth's upper atmosphere between approximately 60-1000 km altitude, comprised of free electrons, different molecular ions and neutral particles, where the extreme solar UV and X-ray radiation causes ionization.

    The ionosphere is a dynamic system controlled by many parameters including acoustic motions of the atmosphere, electromagnetic emissions, and variations in the geomagnetic field. Any atmospheric disturbance affects the distribution of the ionization. As a result, the boundaries of the ionosphere and its regions are not particularly well defined. Various scientific literature sources such as: Chen [1984]; Schunk and Nagy [2000]; Hunsucker and Hargreaves [2003a] give various boundaries for the lower and upper ionosphere, ranging from 60--100 km and 1000--2000 km respectively.

    Realistically, there is no physical boundary separating the layers of the neutral atmosphere, including the ionospheric plasma, from the plasmasphere and magnetosphere at the outer reaches of Earth's magnetic field. From a modelling perspective, the initial and boundary conditions can be derived from observations [Rees, 1989] or by solving simultaneously the current continuity equation and the ion density continuity equation [Streltsov and Lotko, 2008].

    Since my question is very broad and I already know the answer to some extent, I will attempt to clarify. I am working on my PhD and would like to provide better justification for the upper and lower boundaries or the ionosphere and its layers than just a few select references. I would like to start a widespread discussion that brings forward many references and justifications for various characteristic values. Whatever the consensus, this discussion will serve as an additional justification for selecting certain values within a review or model in the future. For example, this type of discussion could potentially alleviate a debate during a thesis defense as the whether the peak density in the model a priori guess should be estimated at 300 km or 350 km for computerized ionospheric tomography (CIT) if data from another source such as an ionosonde is not available.

    As a starting point:
    D-region (60-90 km)
    E-region (105-160 km)
    F1 (160-180 km)F2 (190-1000 km, peak approximately 300 km)

    Looking forward to responses and thank you for your participation in advance!

    David R. Themens

    The quick answer: It's complicated and depends on latitudinal domain of interest or your motivation for caring about how the ionosphere is defined. What's important to an HF person is different from that for a UHF person or VLF person.  

    Generally, the upper boundary of the ionosphere is taken to be the O+/H+ transition height, above which the dominant species is H+. The H+ -dominated region is generally referred to as the protonosphere or plasmasphere and is referred to separately from the ionosphere. There are dozens of papers out there about the O+/H+ transition height, as it is characterized by a change in the dominant scale height and is thereby incredibly important for electron density modelling. Depending again on your motivation for caring about the ionospheric domain, some people include the plasmasphere in their definition of the ionosphere. For example, a GPS person may define the ionosphere as the region of the earth's upper atmosphere that contains an appreciably dense plasma in the context of how that plasma affects GPS signals.

    For the purpose of systems like GNSS, the plasmasphere should be taken into consideration when doing reconstruction with GNSS-based TEC. To effectively reconstruct electron density with these systems, the location/altitude of the plasmapause is extremely important, as this outlines the outermost limit of the necessary reconstruction domain. This plasmapause is however dynamic and depends strongly on latitude. For example, at high latitudes, like say the polar cap region, the plasmasphere is virtually non-existent and plasmaspheric electron content can be considered a negligible contributor to Total Electron Content (TEC).

    On the other end of the altitude spectrum, the D-region is generally negligible in terms of electron density/content; however, the high collision frequency at those altitudes makes it an incredibly important contributor to signal absorption and should thereby always come into consideration in HF propagation models (the very common habit of neglecting collisions in refraction modeling can lead to significant errors at HF frequencies). Below 80km, however, is generally considered part of the mesosphere and not the ionosphere.

    As for your a priori guess for hmF2, it depends again on latitude. When in doubt, use a model rather than a 300km or 350km guess. Both of those guesses would be horrible in the equatorial anomaly region but may be fairly apt at mid latitudes. You can always justify yourself at your defense through the use of a model (however that brings up the next question of why you chose that specific model but that's life, lol).

  • Archak Goel asked a question in Sampling:
    Latin Hypercube Sampling: how to decide sample size of dimensions greater than 3?

    In a Latin Hypercube Sampling, one needs to follow the orthogonal rule i.e., in each row&column there can be only 1 sample. It is easy to visualise it when the dimensions are limited to 3 but what about when the dimensions are 4 and greater? How to decide the maximum sampling that can be obtained in such a design?

  • Avishek Das added an answer in Chemical Bath Deposition:
    How difficult/repeatable is to grow ZnO nanorods on AlN by chemical bath deposition?

    How difficult/repeatable is to grow ZnO nanorods on AlN by chemical bath deposition?

    Avishek Das

    Hi Stive

    Its very easy to grow ZnO nanowire/rod by chemical bath deposition (CBD) on any substrate. You just have to grow ZnO nanoparticle seeds either by Sol-gel or CBD prior to the nanowire growth. It is very inexpensive technique. If you need the recipe, I can help you.

  • John Sosa added an answer in ImageJ:
    Re Masson's trichrome stained tissue. What format (ie., jpeg, Tiff, etc) do I save the image for analysis via Fiji (ImageJ)?

    I am interested in quantifying the amount of collagen in lung tissue regardless of thickness of the section. The sections will be imaged in bright field using a Zeiss scope.  In addition, I found a video showing step-by-step the analysis using ImageJ. Would others agree with this tutorial? 



    John Sosa

    This workflow could work if your segmentation is trivial, but we and others have had phenomenal success for even challenging segmentation (some cases exactly like yours) using MIPAR, our newly released software at http://MIPAR.us. Yes, we are its developers and of course biased, but we are also hardcore end users almost every day. It's use of recipes lets your record your entire segmentation/measurement workflow into a file, and I'd even be happy to make a recipe for you and send it over. It's supports nearly any image type, so no worries about the format. Best of luck!



  • Carlos Araújo Queiroz added an answer in Torque:
    Can Friction force in a rotational medium also be accounted as a load torque?

    Jdw/dt = To - TL - B.(w)

    Where J is the inertia, To is the Applied Torque, TL is load torque and B is friction coefficient. w is the instantaneous angular velocity.

    Can i combine the TL and B.(w) as the net load torque [Assuming B is variable with time].

    Carlos Araújo Queiroz

    Years ago I have studied adaptive control and energetic optimization of aerobic fermenters, having both air flow and agitation speed as manipulated variables. The power dissipated by agitation was accessed by a torque meter inserted at the impeller shaft. The parameters from the (O2 mass-transfer) KLa correlation were successfully estimated using sinusoidal excitation of air flow and agitation speed, through the recursive least squares algorithm with forgetting factor. The (adaptive) control algorithm compared favourably with PID. This investigation was reported at the following MSc Thesis:

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: English title: Fermentation Dissolved Oxygen Control for Minimum Energy Consumption Abstract: A strategy for adaptive control and energetic optimization of aerobic fermentors was implemented, with both air flow and agitation speed as manipulated variables. This strategy is separable in its components: control, optimization, estimation. We optimized parameter’s estimation (from the usual KLa correlation) using sinusoidal excitation of air flow and agitation speed. We have implemented parameter’s estimation trough recursive least squares algorithm with forgetting factor. We carried separate essays on control, optimization and estimation algorithms. We carried our essays using an original computational simulation environment, with noise and delay generating facilities for data sampling and filtering. Our results show the convergence and robustness of the estimation algorithm used, improved with use of both forgetting factor and KLa dead-band facilities. Control algorithm used in our work compares favorably with PID using the integrated area criteria for deviation between oxygen molarity and critical molarity (set point). Optimization algorithm clearly reduces energetic consumption, respecting critical morality. Integration of control, optimization and adaptive algorithms was implemented, but future work is needed for stability. Methods were defined and implemented for stability improvement. We have implemented data acquisition and computer manipulation of air flow and agitation speed for actual fermentors.
      Full-text · Thesis · Sep 1997
  • Pravin kumar Vinit added an answer in Phase Change Materials:
    What is the procedure for naming of zeotrop ( Nonazeotropic mixtures)?

    Naming of zeotrop start with 400 but how we will decide that which refrigerant is R401 & which is R402.....

    Pravin kumar Vinit

    Thanks Saikat Sen. Is Azeotrop follow the same procedure?

  • Bhoj R Singh added an answer in Acute Pancreatitis:
    What are present and future of prophylactic antibiotics for severe acute pancreatitis?

    What are present and future of prophylactic antibiotics for severe acute pancreatitis?

    Bhoj R Singh

    Prophylactic antibiotic use at first may show some encouraging results but soon the microbiota adapt to changes leading more and different type of problems. Several experience have been cited in the link.

    + 1 more attachment

  • Ambika Prasad Poudel asked a question in Theoretical:
    What is the main difference between theoretical framework and theoretical concept?

    I want to make a research study.

  • Sattar Shah added an answer in Fungal Biotechnology:
    Which method is best for Identification /Isolation of Brown rot in stone fruits. Mycology ?

    Which method is best for Identification /Isolation of Brown rot in stone fruits?Mycology?  

    Mycology (fungal disease in fruits)

    Sattar Shah

     Dear Hugo Madrid thank you so nice of you

  • Meeras al-shemarry added an answer in Computer Vision:
    What are the best techniques for plate recognition?

    newest articules about plate recognition techniques

    Meeras al-shemarry

     Thank you very much for your information. please if there is any thing new ,sent it to me...


  • Carlos Figueroa added an answer in Black Holes:
    When two black holes merge, what actually merge ? How to merge their singularities and their event horizons ( or appearent)?

    We did not identify the black hole in full detail yet. Does  it has an event horizon or appearent horizon. We are trying to modify our theory to resolve the problem of singularity.

    Carlos Figueroa

    Hi. I think that we never will know what happens inside of the black hole event horizon. By definition, this zone is forbidden for us. By other hand, though the existence of black holes is almost a scientific done, dont occurs the same with the existence of the singularities. These are just scientific conjectures.
    In other words, we can consider to black holes are its own event horizons.

  • Yusuf Sulistyo Nugroho added an answer in Medical Data Mining:
    Can anyone provide patient database or link of same with various details including Result of disease...?

    Result of disease can be in a form of ......cure/ not cure/ better/ improved

    or anyset of binary which reflect condition of patient in terms of result...

    Yusuf Sulistyo Nugroho

    I would recommend you to check on UCI https://archive.ics.uci.edu/ml/datasets.html

    Hope you can find what you need.

  • Khandoker Mahmudur Rahman added an answer in Consumer Behavior:
    In your opinion, are there specificities for digital consumer behavior?

    I want to know if there is specifities in your opinion about digital consumer behavior ? 


    Khandoker Mahmudur Rahman

    Yes, digital consumers have overwhelming choice of variety as the choice is happening in the virtual world. This perspective has immense influence in defining consumers' definition of value and the power of consumers in identifying the differences in their choices. The following paper talks about the concept of "consumer surplus" in the context of digital economy.

    Brynjolfsson, E., Hu, Y., & Smith, M. D. (2003). Consumer surplus in the digital economy: Estimating the value of increased product variety at online booksellers. Management Science, 49(11), 1580-1596.

  • Abdellatif Benraiss added an answer in Hippocampal Neurons:
    IF on endomembranes and vesicles. Is there a better method than saponin in PBS?

    I am setting up a protocol for IF on endomembranes in hippocampal neurons. Thus far, it has been difficult to obtain crisp clear image even when using saponin permeabilization, as it seems that some structures get destroyed, especially the smaller ones. I found that in the literature MES buffer was used instead of PBS. Do you have any experience in that? What could you recommend?

    Abdellatif Benraiss


    To answer your question, I need more details: how do you fix your tissue? Are you using cryosections of paraffin? What is the thickness of your sections? Do all the solution contain saponin? Do you use secondary permeabilization agent?

    These are all important details to answer you question correctly. I am not sure changing the buffer will help.

  • Jayaram Chikkerur added an answer in Proteome:
    How to blast a protein sequence against proteome of single organism

    I need to blast a protein sequence against the proteome file of single organism

    Jayaram Chikkerur

    Hi Thank you for the reply. Ya I have seen that option, but below that organism box small note was mentioned, that Enter organism common name, binomial, or tax id. Only 20 top taxa will be shown. I am confused with only 20 top taxa will be shown statement. I thought, it will take proteome of all the organisms from the database and will give results for top 20 taxa. Actually, I want to blast a known protein sequence against only hypothetical proteins of an organisms available in the database. Anyway thank you for the response.

  • Song Mengli added an answer in Computational Structural Mechanics:
    What is the criterion to exactly define what is post-buckling?

    Dear All professionals:

    Happy Chinese New Year!

    I am recently model a steel bar under compressive force, and find the trend of load-displacement diagram is not exactly the shape given by Euler bifurcation buckling, which will hold the same magnitude of load after the bifurcation load was reached, instead the real diagram will drop down, so my question is by what time one can define that the bar step into a post-buckling phase?

    Thanks very much!

    Sincerely yours,


    Song Mengli

    Dear Michael, thanks very much for your detailed explanation and supplements, it really helps! Dear Luis, thanks for your information as well! Dear Ariadna, thanks for your useful attachment, they all very valuable for me!

    I will spend a little bit more time to focus on all your suggestion, and find more based on your recommendations, and get back to you if anything I find is still unclear.

    Thanks very much!


  • Azzam K Almosallami added an answer in Schrodinger:
    Can equivalence principle be extended to potentials due to charge and that due to mass when dealing with microscopic particles as electrons?

    If this is so then we can solve schrodinger equation for particles even in gravitational field. 

    Azzam K Almosallami

    I did it and I succeeded. But that required New transformation which lead to the wave-particle duality and the uncertainty principle. Read my paper http://vixra.org/abs/1509.0059

    The problem here there is no objectivity and continuity in nature. Nature working same as the Copenhagen school interpretations.

  • Naveen Kalra added an answer in Fertilizers:
    Any review article on agronomic efficiency, physiological efficiency, applied inputs' efficiency of various nutrients for crops/cropping systems ?

    fertilizers management is important from viewpoint of sustainable production. Various efficiency indices have been employed in literature and worked out by researchers under different management options.

    agronomic efficiency

    physiological efficiency

    apparent recovery efficiency

    contribution from soil

    all these indices values are dynamic and dependent upon biotic and abiotic stresses.

    Efficiency of micro-nutrient fertilizers is quite low, and we are trying to evolve technique through new products and agronomic management for enhancing the efficiency of these costly fertilizers.

    we are interested to know the range for specific nutrients as far as these indices are concerned? 

    Naveen Kalra

    Dr Subba Rao, I fully agree with you and we can think over this imp aspect of consolidation of efficiency range for crops/cropping system as far as different nutrients are concerned and moreover for different growing regions


  • Jorge A. Quirós-Rodríguez added an answer in Gastropoda:
    What is the species of this gastropod found from near an estuary mouth?

    Recently a flood occurred in a city (India) which is located near an estuary. Will these species be pure terrestrial gastropods, estuarine gastropods or marine gastropods. I am confused totally. But I found from an estuary mouth without meat (empty shell). 

    + 1 more attachment

    Jorge A. Quirós-Rodríguez

    Yambem, it could be of the Ampullaridae family (presumably Marisa), this snail prefers places slow-moving freshwater with aquatic vegetation, although you can find it in some estuarine areas


  • Sudarson S. Sinha added an answer in Graphene:
    How to write an octave code for simulation of the graphene sheet that in the size we want when we enter the position of the atom in the unit cell ?

    I add a picture which I want to show when we run this code.I just started to learn graphene and programming,this is my first job to do.I think that I should start by writing the unit cell and then repeat it along the lattice vectors.I do not know how should I start.is it the right way or not ?Is there anyone can help me about that ? Thank you :)

  • Khandoker Mahmudur Rahman added an answer in Likert Scale:
    Is there a (statistically based) significance threshold for Pseudo R Square in Ordinal Logistic Regression?

    Model with Ordinal Independent Var (Likert scale) and ordinal Dependent var (Likert scale).

    Categorical Moderating Var.

    For example scores:

    Pseudo R-Square
    Cox and Snell ,161
    Nagelkerke ,177
    McFadden ,074

    Khandoker Mahmudur Rahman

    There are many versions of pseudo-R2, as you already noted most popular three of them. In fact, Ologit does not have the exact equivalent of the R2 as is found in OLS. However, in simulated studies comparing OLS output and equivalent Ologit output, it was found that McKelvey & Zavoina's pseudo R2 was the closest to the OLS R2 ( I think Stata has a downloadable module to calculate that as well). Now, this is not the answer to your question. This is just to highlight the problem of common interpretation of pseudo R2 and the debate in the scholarly community. About statistical significance threshold, there is none that I came across. Somebody please correct me if I am wrong. However, these figures are still useful in the context that when two models may be compared with the same datasets and same DV, the higher pseudo R2 may indicate a better model predictability.

  • Kamal Chandra Paul added an answer in R&D Management:
    Can anyone help me on literature of Innovation performance and R&D management practices?

    I'm planning to conduct a research on Innovation performance and R&D management practices. Can anyone help me on literature? The tentative topic will be "How the R&D management practices affect on innovation performance in software development industry". The study will be carried out in the Sri Lankan context.

    Kamal Chandra Paul

    Sorry for the late reply. To me you can search for the following literature as your TOPIC;1.Development model related technical based research (latest research better), 2.R& D Management practice,& 3.Innovation development related new technical products. It will guide you the whole research process.Anything want to know more please you can write me again until clear your concept.TQ,Paul,herbal researcher on Good Manufacturing Practice,Uni Putra Malaysia(UPM)

  • Shako Ahmed asked a question in Sampling:
    Can you please show me which values of (q) and (p) i have to use in cam-clay?

    I want to plot Cam-clay and/or modified cam-clay by using 4 sets of triaxial data from 4 samples.