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

  • Murat Ozdemir asked a question in Boundary Condition:
    How to derive boundary conditions of kirchoff's plate for bending problem by variational principles?

    How to derive boundary conditions of kirchoff's plate for bending problem by variational principles ?

  • Djanahana Djanahana added an answer in VANET:
    How can I simulate VANETs networks with NS2?
    I want to simulate VANET network in order to trace a normal network before the addition of a malicious node. I would like to do this with NS2.35. Have you any ideas how it could be the simulation, I have successfully installed NS2 on UBUNTU 12.04 LTS.

    Many thanks Mr.Toutouh, it seems a very good link, I have try to simulate VANET with you code and I am still reading the instruction in the readme file, thanks, I wish I can simulate VANET correctly, until now I am not sure of the appropiete  Routing protocol to use for VANET simulation, if you have more information about VANET simulation I will be appriciate,thanks once again

  • Parviz Parvin added an answer in Radium:
    Is it possible to Conduct agood Measurements of Uranium, Radium and Radon Exhalation Rate of Soil or water samples by using SSNTDs?

    Measurements of Uranium,  Radium and Radon Exhalation Rate in water and soil

    Parviz Parvin · Amirkabir University of Technology

    Let employ CR-39 and following chemical etching to develop the alpha tracks due to the decay of U,Ra and Rn radionuclide. Furthermore, polycarbonate as another SSNTD  may be used mostly with electrochemical etching to develop the alpha tracks accordingly. However this method the exhalation rate measurement is sluggish, usually needs high dose (flux * exposure time).

  • Pradeep Chakkarath added an answer in Tv shows:
    Does anyone have any recommendations/suggestions of TV shows or movies that simulate racial microaggressions?

    I am starting my dissertation on racial microaggressions and I'm in search of examples of the different forms of racial microaggressions (Microassaults, Microinsults, and Microinvalidation).

    Any suggestions of specific titles, or sites to search would be greatly appreciated.

    Pradeep Chakkarath · Ruhr-Universität Bochum

    Dear Danita,

    Just recently, the movie "Dear white people" (2014) was released. It is about four African American students attending an Ivy League college in the US. The questions you're interested in, are central topics in the film which is based on personal experiences of the director (Justin Simien). Also interesting: "Future Children" (a clip about racial micro-aggressions):


    Other than that, the list of possible hints is endless, of course. Just a few: "The Big Bang Theory", the "Harold & Kumar" movies, "Coming to America", the "Star Trek" episodes and last but not least: The "Indiana Jones" movies, especially "Indiana Jones and the temple of doom."

    Good luck with your dissertation!

  • Dragan Pavlovic added an answer in Aristotle:
    Which links exist between the logic in De Interpretatione and the ethic of Nicomac, between truth and good for Aristotle?

    Would you say that there is an implicit logic in the Ethic or that the purpose of good in a way means truth? 

    Dragan Pavlovic · Dalhousie University, Halifax, Canada; European University, Belgrade, Serbia.

    Do we need logic for ethics? I thik yes. Harry Gensler wrote a fantastic book on "Formal ethics".


    The deontic logic should be able to help. We need more elaborated "deontic logic", I am would say, to grasp various ethical issues too.

  • Jamal Bouoiyour added an answer in Nonlinear:
    Do univariate and bivariate wavelets bias results?

    Wavelet methods have been successfully applied in various issues. They will surely replace  gradually the classic methods of cointegration and causality.
    The interest of wavalet is that they do not require stationarity and the analysis is done with nonlinear variables.Indeed, there is evidence showing that several economic variables display consistent nonlinear dependencies. But, one common feature to the papers using wavelet analysis is that they rely on univariate and bivariate frameworks. This is equivalent to a simple correlation analysis.

    Do we consider the results of these assessments as biased?

    Jamal Bouoiyour · Université de Pau et des Pays de l'Adour

    Thank you for your comment.

    I am not an expert on the subject. But from my limited experience, the results are radically different when we take into account or not control variables in the estimates;

  • Alice Sterling Honig added an answer in Psychiatry:
    What are some practical ideas for providing trauma-informed services?

    I teach a variety of continuing education seminars to practitioners who provide public behavioral health care services in Pennsylvania. I am always looking for practical and accessible information for these courses that, broadly speaking, address trauma, PTSD and complex PTSD in various populations across the lifespan, including children, adolescents, veterans, adults with Serious Mental Illness, including Personality Disorders, and  co-occurring disorders, etc. SAMHSA's publication of TIP 57 (Trauma-informed Care in Behavioral Health Services) is an excellent reference. I was wondering if there are individuals who have experience with developing or providing a training series to staff about the actual implementation, e.g., the "what" and the "how's" of practices that are trauma-informed. Thank you.

    Alice Sterling Honig · Syracuse University

    After traumas people often report that they  feel shame and   guilt a if somehow there is something wrong with them for feeling and being how they are. They feel sometimes desperate to keep  secret ofo  their pain and shame and this may be particularly true for men. . So helping them disclose and talk about those deep pains and terrors and shames and rage too, s can help draw OUT THE POISON. AND Also may well decrease the self-medication by drugs and alcohol.. Sometimes too

    Sharing in groups helps . Sharing their painful stories bring realization that they are not alone in  their pain and angers and shames. And groups may be particularly  helpful  for men who have "macho"ideas about hiding pain and not crying. In a group you can cry with others who experienced and understand  the deep   pain!..

  • Hazem Y. Abdelwahed added an answer in Audiology:
    Will steroid injection in the inner ear affect IPSI and Contra ABR results?
    In a sudden hearing loss patient, will steroid injection in the inner ear affect IPSI and Contra ABR results?
    Hazem Y. Abdelwahed · King Saud University

    "In a sudden hearing loss patient, will steroid injection in the inner ear affect IPSI and Contra ABR results?"

    Do you mean steroid injection into the middle ear, not in the inner ear . New modern version of ABR can be applied even in presence of ME effusion. Regarding injection of steroid into middle ear, will not affect as steroid will be already drained via Eustachian tube & that is why we ask patient to not swallow pre & post injection to lengthen steroid' presence in middle ear as long as possible to be effective. Later on before applying ABR, except if it is modern version, you can ask your patient to swallow so as to help the drainage of the rest of drug via Eustachian tube. 

  • Volker Lohweg added an answer in Microcontrollers:
    How popular is the use of FPGA for applications in Robotics?

    I have been wondering how popular FPGA is in the Robotics domain. 

    Have you implemented a robotic system based purely on a FPGA?

    If so, do you prefer it over the conventional microcontroller/microprocessor?

    Please feel free to share your perspective and experience!

    Thank you,


    Volker Lohweg · Hochschule Ostwestfalen-Lippe

    Your question is mis-leading a little bit. You might ask for what are FPGAs useful in robotic applications. And which robotic robotic application do you mean? Industrial, humanoid, multi-axis, transportation, etc.

    However, now I give you my answer. An FPGA might be useful in some applications, but as algorithms for motion control are quite complex you need large (LE/CLB/Slice count) units which are expensive and therefore, they will probably used for R&D but not for an end-product.

  • Yuan-Yeu Yau added an answer in Plasmids:
    What is the conc. (and purity of PCR product at 260/280nm) that could be used for sequencing?

    What is the conc. (and purity of PCR products at 260/280nm) that could be used for sequencing. I have DNA samples amplified by PCR and thinking to use directly for sequencing than using the extracted plasmid with insert as it is less concentrated to be used for sequencing. I am wondering about the purity of my PCR products as it could have some primer and dNTP remainants that could compromise sequencing. The con. of my PCR products are 200-350ng/microlitre with 1.8-2.03 at 260/280nm. Is this ok to be used for sequencing? Anyone who can help me please?

    Yuan-Yeu Yau · Northeastern State University

    The ratio of absorbance at 260 nm and 280 nm is used to assess the purity of DNA.   A ratio of ~1.8 is generally accepted as “pure” for DNA (see attached Nanodrop bulletin). The recommended DNA quantity is dependent on the  size of your PCR product. For 500-1000 bp, 10-20 ng needed (see attached ABI BigDye booklet, page 13, Table 3). So, I think you are good to go. Try and find out.

  • Are gas and oil, and in the future drinking water blessing or a curse of modern geopolitical expansion of globalism?

    The development of civilization shows that for economic growth and technological development needs more and more energy ....

    In this context it should be noted that the main geopolitical disputes and conflicts are related to the richest and the most profitable reserves of future world oil production and natural gas, and that conflicts in the guise of a clash of civilizations are in fact conflicts over energy resources and in the future over drinking water...

    Vanessa Meloni Massara · University of São Paulo

    Dear Dr. Darko,

    Surely the competition for fossil fuels can unfortunately become cause of geopolitical disagreements in (near) future.

    However, even being the area of energy, I believe that the absence of water still will be a cause of greater dispute. Maybe I'm tendentious in this matter, because of the "dry season" that southeastern of Brazil has confronted and also about the question posed at RG by Dr.Palani Shanmugasundaram: 
    "Are seawater to drinking water projects Functioning in your country / state successfully?"


    We expect conscious consumption, developing new sources of energy and others ways of .sustainability (...) that can meet the needs and this critique hypothesis comes not happening.

    In summary, all these natural resources that make a country occupy important political and economic position in a globalized world, can have their "blessing" reversed.

    This discussion is endless.

    Best Regards,


  • Liaque mohammed Latif added an answer in Aging:
    Does anyone have a model of studying aging in cell lines?

    I am attempting to study the effects of aging on a range of proteins in specific cell line. Can anyone suggest any method they may have used in the past?

    Thank you

    Liaque mohammed Latif · University of Nottingham

    Hi Lyle, interesting suggestion, just have concerns over how you would distinguish between changes in phenotype due to been maintained in culture and mutations resulting from ageing?

  • Are you interested to cooperate in an Int. Reserch project addressed to evaluate the impact of Person Centered Clinical Method on Clinical Practice ?

    Person Centered Medicine is an epochal change of Medicine, Medical Science and Medical Education whose destiny is to change the quality of Health Care delivery as we have seen in the first pilot investigation of Person Centered Medicine Clinical Method on clinical practice which depicted amazing results.

    You could find it in


    The Person Centered Medicine International Academy would like to spread this investigation all over the world.

    If you are interested in it we could cooperate for realizing the research project we made in your country.

    Prof. Giuseppe R.Brera


    Sandra Fortes · Rio de Janeiro State University

    Dr. Giuseppe,

    some of the researchers form the LIPAPS ( lnterdisciplkinary  Laboratory for primary Care Research) in the UERJ ( university of Rio de Janeiro State) are doing some qualitative research on this area. We would like to know morw about your project. but the link is broken. thank you.

  • Presentation of Data - What do you show on boxplots?


    I am writing my thesis results section and wanted some advice on presentation of data.

    Would it be appropriate to use IQR (25-75) as the box, 1.5*95% CI (outliers) as the whiskers, with both mean and median lines, to highlight the lack of normality in some continuous data sets? In the text, I give mean/95%CI for normally distributed data, and median/IQR for non-normal/non-continuous data.

    I have plotted each data set as I have reported (i.e. only showing mean or median line), but am wondering whether what I outlined above would also be an appropriate approach.

    Help much appreciated!

    Clement Oluseye Ogunkunle · University of Ilorin

    @Jochen. Thank you sir. But you seems to forget my last question. I asked if it is only non parametric that boxplot can be applied? I read in a paper that boxplot is primarily to describe non parametric data. Is there any truth in that statement?

  • Michael Uebel added an answer in Settlements:
    What are some relevant literature that address "diasporic communities" and spacial settlement of immigrants?

    I am looking for relevant literature that addresses the topic of diasporic communities and settlement of immigrants in countries of destination. The literature should give some information on how migrants settle in receiving countries/ why they settle in certain cities and the choices available to them.  

  • Do cancer stem cells really exist or are they just derived from normal tissues? Can their origin be traced?

    Just for curiosity. Do cancer stem cells (CSCs) really exist or they are just derived from normal tissues. Can their origin be traced?

    Niloy Kumar Das · Shahjalal University of Science and Technology

    Yes cancer stem cell exists. Actually scientists have found similarities between stem cell and cancer cell, like regeneration capability, apoptosis resistance , motility so they termed those cancer cells as cancer stem cells.

    Cancer stem cells origin already traced. This cells originate from epithelial layer where Epithelial Mesenchymal  transition occurred and normal epithelial cells turned into motile, invading cancer stem cells

  • How is "sustainable regional development" approached in your country?

    I am looking for experiences and publications addressing policies, models, methodologies and instruments used.

    Daniel Klimovský · Comenius University in Bratislava

    Dear Isabel,

    Concerning sustainability of regional development, in Slovakia innovation policy became a "policy fashion" recently. There are several interesting publications focused on implementation as well as impacts of such policy/some of its tools in Slovakia (part of them are published in English). Another popular concept is creative economy; and again, one can find some publications addressing this concept and its implementation in Slovakia.

    Best regards, Daniel

  • Bojan Najdenov added an answer in RDF:
    Is there any tool for creating RDF triples from simple text of any type?

    Hi Gurus, I want to ask that is there any tool for creating RDF triples from simple text of any type. If not what is the tradition generally? how people do it? Thanks

    Bojan Najdenov · Ss. Cyril and Methodius University

    Hi Kims,

    I was doing a little research last year, on tools that do "automatic" ontology creation from text as input. They may also help you to extract the information and create RDF triples
    Here are the tools that I found:

    - OpenCalais - web application, very easy to use and it will help you get RDF data from text

    - Dresden Ontology Generator for Directed Acyclic Graphs (DOG4DAG) - Protege plugin, v4.1 and v4.2.
    - ACE View - Protege plugin v4.1
    - OntoLing - Protege plugin v3.4

    - LexOnt - Protege plugin, but unfortunately is not open for use and tryout, I put the link from the paper from the creators of the tool.

    Bojan Najdenov

  • Stuart Locke added an answer in Banking Sector:
    What is the minimum acceptable ratio of the volume of banks’ credit to the GDP?

    The volume of banks' credit to the Gross Domestic Product (GDP) is used as an indicator to the participation of banking sector in the economy of a country. What is the minimum acceptable ratio of the volume of banks' credit to the GDP?

    Stuart Locke · The University of Waikato

    The maturity of the financial sector is a key variable.  Empirical estimation is likely to show a negative and significant coefficient.  For low income countries (LICs) and emerging economies the degree of financial integration (formal and informal sectors) is low vis a vis mature economies.

    The speed of transaction approval related to technology, bureaucracy and corruption will impact in negatively.  The depth of the financial markets will play an important role as will the openness of the economy.

    Regulatory framework is obviously important but the next big variable is the difference between Islamic and non-Islamic financial systems.

    If you are not undertaking empirical research my suggestion is to start with 100%, as Burakov, noted in his cogent response, and then argue theoretically pluses and minuses to make additions and deductions.  You may not have percentage adjustments that you can make but you should get a good feel for the direction.

  • Volker Lohweg added an answer in Wavelet:
    How do you estimate wavelet packet frequency?

    I have attached the figure to understand the frequency arrangement of the wavelet packet. How from {depth=8, index=0}= the approximation boundary is 86?

    Volker Lohweg · Hochschule Ostwestfalen-Lippe

    Your qestion is insufficient. If you do not know what your application I you do not have any idea what you would like to know. Wavelet packet filter are designed based on the application. Here: what wavelets are used? What is the sampling freqeuncy? Etc., etc, etc.

    Please explain what you would like to know in detail and in a more scientific (rigor) way.

  • Javad Modarresi added an answer in DIgSILENT:
    How can I model the synchronous condenser in the DigSilent?


    I want to model the synchronous condenser in digsilent. But i cant do this.

    Javad Modarresi · University of Isfahan

    thanks for your answer Mostafa

    I inserted a synchronous machine and then active power=0.  The Injected active power by synchronous machine is zero in power flow analysis but in the time domain simulation the injected active power is not zero.

  • Argyro Velonaki added an answer in SWOT analysis:
    If you were conducting a SWOT analysis on the impact of Social Media as a data collection instrument, what would you list as "S" "W" "O" "T"?

    When I refer to social media I mean Facebook and Twitter predominantly. 

    Argyro Velonaki · Manchester Metropolitan University

    Comments and links are much appreciated. Thank you all for taking time to answer my question. 

  • Has anyone experienced artificial neural networks for learning logical formulae?

    Given a set of CNF logic formulae, I intend to develop a benchmark for understanding what topology of feed-forward network is suitable to learn each formula. I would like to now if something already exists in the state-of-the-art and if it would be an interesting contribution if those formulae are put into a specific context.

    Volker Lohweg · Hochschule Ostwestfalen-Lippe

    Yes, learning of CNFs and DNFs are well known. It was a hype topic in the 1990s and beginning of 200xs. Usually a net or a classifier was trained of the base of Walsh or Hadamard functions because one can design CNFs/DNFs quite nicely. You normally end up with a learned state macine. If you take a look into e.g. IEEE or ACM papers you will find the topic. I read some paper regarding this topic but this is ago 10 years or so. Hopefully it helps at least a little bit.

  • Niloy Kumar Das asked a question in Cancer Stem Cells:
    Does hormone/enzyme/specific protein have any effect over Cancer Stem Cells for food consumption?

    Cancer stem cells are the precursor of spreading cancer throughout the body. I need some article(research&review) where hormonal effect over cancer stem cells for food consumption illustrates.

    Thanks in advance

  • Akm Rokonuzzaman asked a question in Silicon:
    I am trying to prepare a presentation of ''Recent advances in Silicon based Polymers'' Can anyone help me to prepare this?

     ''Recent advances in Silicon based Polymers

  • Arno Gorgels added an answer in Philosophy-Theology-Science public:
    Was twentieth century science atheistic?
    As from 1967, at the time when I was being taught Special Relativity, I got the impression, indicated by my physic's professor, that I should accept atheism as a pillar of modern science. Was that impression correct? Cantor's Universe, that I teach, allows in principle a theistic view. Now, I wonder: What is the contemporary opinion on this subject? I am interested to hear some opinions. What is yours? Do you practice science from an atheistic point of view?
    Arno Gorgels · Principia Naturae

    I found it thru googling. Is that the only way? RG?

  • Marcel Bucher added an answer in Cleome:
    How can I find the genome sequence of Cleome spinosa or Cleome gynandra?

    Can anyone please tell me how to find the genome sequence of Cleome spinosa or Cleome gynandra ?

    I know Cleome spinosa is fully sequenced and that the assembly is available. I cannot seem to locate it.

    Thank you very much.

    Marcel Bucher · University of Cologne

    The persons to ask are Professor Andreas Weber or Dr. Andrea Bräutigamm from University of Düsseldorf. 

  • Niloy Kumar Das added an answer in Competent Cells:
    Hi, I have two enzymes - EcoR1 and Kpn1. Both the enzyme expirations dates in 2010. Can I use these two enzymes for cloning?

    Hi, I have two enzymes - EcoR1 and Kpn1. Both the enzyme expirations dates in 2010. Can I use these two enzymes for cloning? Will it work and, if yes, will there be proper restriction overhangs? Because my insert is just 700 base long and I find it very difficult to get it cloned. After double digestion, vector gives desired single band. but I doubt if the overhangs are maintained.The PCR product is good. my competent cells and transformation protocol is fine. and i use new vial of T4 DNA ligase. 

    Thanks in advance ...

    Niloy Kumar Das · Shahjalal University of Science and Technology

    It depends. Better if you done a small experiment  whether it provides you desired result or not. All the best

  • Dominique Liger added an answer in Taq Polymerase:
    I am using Genei Taq polymerase which amplifies the target gene in a plasmid but it does not amplifies a particular cDNA from RACE protocol. helpme !

    10X Taq buffer and MgCl2 were provided separately and i am using these at 1X concentration. Positive control and Water controls are working good but the target cDNA has not yet been amplified.

    Dominique Liger · Université Paris-Sud 11

    Hi there,

    Are you using exactly the same set of primers for both experiments on plasmid and mRNAs? If yes there might be a problem with the mRNA template you are using.

  • Which software tool can be used for optimization over integer variables?
    I tried to do two-objective non-linear optimization over three decision variables: one real and two integers. MATLAB optimization toolbox did not help. Does anybody have experience with Cplex?
    R. Russell Rhinehart · Oklahoma State University - Stillwater

    Nuno Ricardo Costa.  Thanks for the question.  Yes, I think the optimizer algorithm, objective function, and convergence criterion need to be appropriately chosen.  Leapfrogging is a general multivariable optimizer, that only uses function values (not gradients).  It is a multi-player approach that observes multiple trial solutions simultaneously.  Although the optimizer treats decision variables (DVs) as continuous, they can be truncated to integer values for the calculation of the objective function OF).  When this happens small changes in the continuum DV version may not make changes in the integer version, so from the optimizer perspective, the OF has flat spots.  In this case the convergence criterion should be appropriately chosen.  One approach for multi-player optimizers is to claim convergence when the cluster of players is small, when the DV range of all players is small.  This works when continuum variables are converted to integers.  However, if all players are giving the same integer versions of the DV, then the OF will  be the same for allplayers. So, for integer applications, I prefer to claim convergence and stop the leap-overs when all the player OF values are the same.