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  • Abdelaali Chaoub asked a question in Visual Search:
    Mobile Visual Search, any new ideas?

    Interested in doing some research in Computer Vision and Mobile Visual Search. Could you please suggest some novel ideas/issues that are emerging in that research topic?

  • Claes Richard Fredö added an answer in MATLAB:
    How to make structure to variables in matlab ?

    please if any one have an example for calling structure variables  from text file,

    i will be glade to him .

    Claes Richard Fredö · Qring Technology Intl. AB


    A general view of your import options from text files to matlab is found here http://se.mathworks.com/help/matlab/import_export/supported-file-formats.html

    One of the simplest import types for numbers is to use the command

    load file.txt -ascii

    This produces a matrix variable calles file

    Here is a small example borrowed from mathworks

    a = magic(4);
    b = ones(2, 4) * -5.7;
    c = [8 6 4 2];
    save -ascii mydata.dat a b c
    clear a b c

    load mydata.dat -ascii

    Note that the above works only for import of numbers.

    If you use instead xlsread to read Exceldata. Again a small example borrowed from mathworks

    Create an Excel file named myExample.xlsx.

    values = {1, 2, 3 ; 4, 5, 'x' ; 7, 8, 9};
    headers = {'First','Second','Third'};
    xlswrite('myExample.xlsx', [headers; values]);

    Sheet1 of myExample.xlsx contains (layout below is lost):

    First Second Third
    1 2 3
    4 5 x
    7 8 9

    Read data from the first worksheet.

    filename = 'myExample.xlsx';
    A = xlsread(filename)

    A =
    1 2 3
    4 5 NaN
    7 8 9

    xlsread returns the numeric data in array A.

    To put the above into a structure, e.g. called MyExample, I believe (I have not tested it) you can write

    MyExample.FirstExample = file;

    MyExample.SecondExample = A;

    You could store the data such that

    MyExample(1).Matrix = file;

    MyExample(2).Matrix = A;

    MyExample(2).Headers = headers;

    MyExample(2).Values = values;

    Hope this helps


  • Selmi Naceur added an answer in Aircraft:
    How to control a VTOL aircraft which considers only the longitudinal motion via controlling the pitch-angle?

    In practice, the RHP Zero is a problem which causes accidents. Could anyone explain more to me?

    Selmi Naceur · LGM , Monastir, ENIT, Tunis


    The vertical takeoff and landing planes(VTOL) use completely or mainly the propulsion system for the control of attitude and of trajectory, It is thus necessary to control the aircraft attitude  and the trajectory, in the case of the longitudinal movement, it thus should be used another thing that the RHP, or aerodynamics, ineffective at low air speed.

    One of the solutions of topicality is control by vectoring thrust, or jet control surfaces or devices (nozzles or jet activated flaps) far from gravity center which creates an effective moment forces to control pitch roll and yaw moments.  This efficiency is needed at low air speed to avoid lost control or spin departures.  

  • Roman Voronov asked a question in Fluorophore:
    How do you pick the type of laser when building a microscope system?

    Power?  Wavelength?  Circular vs Elliptical beam?  I know that there are fluorophore considerations, but isn't there a range of different fluorophores available at different wavelengths?

  • Wolfgang K L Ruck added an answer in Agilent:
    Does anybody know the cause of a drastic fall in the relative abundances of both m/z 219 and 502 (diagnostic ions for the PFTBA calibrant in GC/MS)?

    We have noticed that both relative intensities have significantly dropped after performing maintenance tasks (replacement of both EI filaments and cleaning of the EI source) in the MSD as a consequence of a great air leak. Specifically, the relative abundance of m/z 502 (1.97%) is below the threshold limit recommended by Agilent Technologies (2.4%). We have checked everything possible and we do not find out what is wrong.

    Wolfgang K L Ruck · Leuphana University Lüneburg

    When did you the last dynamic mas-axis-calibration with masses up to 500??

  • What is reality? What are facts?
    I have noticed some scientists/scholars to equate reality to facts and facts to reality with assertion. In my opinion using them synonymously is a fallacy which must be consciously avoided, because in: Facts are statements about some events or circumstances that exist or that have occurred. Facts are observable (measurable), verifiable and indisputable whatever measure of reason and logic is applied to or reject them.
    Reality (Constructed, Objective, Subjective, Empirical, Instrumental and other Realities) is nothing but a collective opinion - an idea in which some confidence is placed or, a reasonable collective representation of “the way things are.” Reality is not simply acknowledged, but must be discovered or reasoned and is liable to falsification.

    For example, we know it is fact day will come after night. It is a fact that the Earth rotates on its axis resulting in day and night. It can be verified or observed from space. It also can be verified that the Earth revolves around the Sun. On the basis of these two facts we reckon time. But, what is reality of time? To some it is linear, to some opinions it is cyclic and to some it is fractal. To convince one of one of these three realities of time, it is to be reasoned out on the base of some facts.

    There is an objective reality out there, but we view it through the spectacles of our beliefs, attitudes, and values. ~David G. Myers

    << Fundamental entities that reside at the bottom of the ontological food chain. Higher level entities (such as mirages) supervene or emerge from the more fundamental entities (those we have experienced),

    Not sure if it is supervenience or epiphenomena.

  • Takeshi Nakamura asked a question in Photobleaching:
    How does a fluorescence recovery of GFP after a fluorescnce decrease by a light exposure happen?

    We have observed a fluorescence recovery some minutes after a fluorescnce decrease by a light exposure of GFP and its derivatives some minutes some minutes after a fluorescnce decrease by a light exposure. Clearly, this is not a simple photobleaching of chemical fluorescent dye. How does it happen? I think that this is a kind of photochromism, however, I cannot find any literatures which precisely explain this fluorescence recovery of GFP.

  • Abbas Rahdar asked a question in Thin Film Deposition:
    What are the methods to create a plasma in the chamber for the thin film deposition ?

    What are the methods to create a plasma in the chamber  for the thin film deposition ?

  • Peter Smetacek added an answer in Personality:
    Who has got more power: the Gray eminence or the Head?

    Throughout history there have been many high-profile cases of personalities behind the scenes directing power with or without the consent of the person who would have had the charge to exercise it.

    In ancient Rome: Seneca and Nero

    In France: Richelieu / Mazzarino versus their king

    In the US: Eleanor Roosevelt versus Franklin Delano Roosevelt

    In every day's life:

    wife versus husband
    secretary versus head of the department
    assistant professor versus Professor

    And in your life would you prefer to act as  a gray eminence or as a head?

    Peter Smetacek · Butterfly Research Center, Bhimtal

    The question you ask is the answer you get: in this case, I would beg to point out that each of us plays multiple roles in our everyday life, as well as in life in general. So there are times when we are the grey eminence and other times one is the head. For the competent, the roles are usually thrust upon them, so they find themselves as actors in an unfolding drama. For the incompetent, the position is usually achieved with much scheming and plotting. Regardless of the means of achieving the role, one will often find that the roles change from day to day as the situation unfolds, so that sometimes, wily-nilly, one is safely behind the scenes, the grey eminence and at others, one is facing the music or the glory broadside on in the role of head....
    To return to the posing of the question, this is not a matter to which one can safely pose as an either/or choice, but concerns a both/and viewpoint.

  • Uchurappa Mala added an answer in Lentivirus:
    Could we use the DH5alpha instead of Stbl3 for lentiviral plasmid transformation and cloning?
    I will perform some transduction with lentivirus produced in our lab (not commercial made). At Addgene they say that the plasmid that I've got should be transfomed into Stbl3, however I was wondering if i could used the DH5a strain. Anyone has any similar experience?
    Uchurappa Mala · Indian Institute of Science

    I have spent at least 6 months to get a good pLenti6.3 plasmid by using Stbl3. Here I wanna share some of my experiences about pLenti and Stbl3. As above mentioned we have to use low salt con. 5g/L, culture should be grown just 8-10 hr only otherwise plasmid yield/quality will be poor. 

    I followed above things so finally I got good plasmid(+gene), but the transfection efficiency/virus quality is poor when compared to vector, still I have no idea why the efficiency is varying, though I could see equal quality of plasmids on agarose gel. After selection with selection marker I could achieve stable cells. 

    Thanks everyone for your  more valuable information about Stbl3 and pLentivirus.



  • Nickky Spesivtsev added an answer in SEM Analysis:
    Could the expert help me to find out the zeolite type in SEM analysis?

    I sythesized some zeolites and conducted the SEM and XRD analysis. The XRD analysis showed that the phases are: 

    Zeolite A, (Na) NaAlSiO4•2.25H2O PDF卡号39-0222

    Zeolite P, (Na) Na3.6Al3.6Si12.4O32•14H2O PDF卡号44-0052

    F: Faujasite-Na, syn Na2Al2Si2.4O8.8•6.7H2O PDF卡号12-0246.

    The problem is that I donot konw the zeolites in the SEM analysis. Could anyone help me? Thanks in advance.

    The attachment is the XRD and SEM files.

    Nickky Spesivtsev · Gubkin Russian State University of Oil and Gas

    Yao, has your SEM a EBSD?
    It really could be the right solution for your question.
    But you need a very thin beam(<1 μm) to aim directly on every particle, as you can see.
    Something like SCD. If i'm not mistaken, the diameter of e-beam is about 2, maybe 5 micro, so you can try it. 
    About EDX and morphology: as other man already said you can't use that info to confront  zeolite types with one hundred certainty.
    Maybe STEM could help, but i guess in your situation it's impossible to make such analysis on THAT thing.
    Hope it helps.

  • Akira Kanda added an answer in Wavefunction:
    Does consciousness really collapse wavefunction?

    I am not sure about mechanism of wavefunctiin collapse. What do you think?

    Akira Kanda · University of Toronto

    > I think the wavefunction itself is precoded to collapse in a specific manner under given circumstances as if the particle wave makes its own conscious decision. It may have nothing to do with the consciousness of the observer.

    In the von Neumann formalism, there is no explanation of when the wave function collapse  relating to macro measurement. It is just a hypothetical mathematical phenomenon which leads to yet another totally hypothetical probabilistic distribution of the alleged possible measurement results as eigenvalues. Von Neumann said that if you repeat the same measurements, the state vector will not collapse in the second try, aka "idempotent" property of the quantum measurement.  But as we all are told that time is continuum. So there is no such thing as the next time. Do we have a real number next to 1? Mathematics is not just a language. If you want to use mathematics as a language you better understand the language before you get into trouble.

    This problem clearly shows that von Neumann was a dumb good mathematician but a mediocre physicist. In science there is no such thing as geniuses.

  • Can you suggest papers for sentiment analysis in smart cities?

    Dear researchers,

    can you please suggest papers about how sentiment analysis can be applied in smart cities?

    I found this one for example : “A. Vakali, D. Chatzakou, V.A. Koutsonikola, and G. Andreadis, ‘Social Data Sentiment Analysis in Smart Environments - Extending Dual Polarities for Crowd Pulse Capturing’,  ;in Proc. DATA, 2013, pp.175-182.” .

    any more?

    Diogo Pereira Henriques · University of Lisbon

    Maybe you can check this link of Beth Simone Noveck' s talk at the International City/County Managers Association, Boston, MA 2013, where she focused on the opportunity for those who govern to use a variety of new technologies to tap the intelligence and expertise of their communities.

  • Selva Selvarajah added an answer in Denitrification:
    Is there sufficient evidence for NO3 to be immobilised in soil?

    Ammonium (NH4) is immobilised by soil bacteria which is a common pathway in N cycle. Nitrate (NO3) is reduced to N2O or N2 via denitrification process. Sometimes NO3 can be reduced through dissimilatory reduction by bacteria in anoxic groundwater. Is there evidence for NO3 reduced into organic matter in soil? If so how common this pathway in soil? 

    Selva Selvarajah · Enviroknowledge Ltd, New Zealand

    Thanks for the comments Sylvie. The timing of your comments is perfect since I have just spent my weekend time sifting through a large number of papers on this topic. From an extensive literature review, I draw the following conclusions:

    (1) Best way to tackle the question on direct NO3 assimilation is to deal with bacterial metabolisms. The key is that cytoplasmic assimilatory nitrate reductase (Nas) is responsible for the direct assimilation of NO3. This enzyme is induced by NO3 and repressed by NH4 but not affected by O2. As pointed out by Sylvie, direct assimilatory process is very energy taxing which includes the use of ATP to transport NO3 into the cell with the subsequent assimilation demanding 8 electrons to convert to NH4.

    (2) Phyllogenetically, the above enzyme (Nas) is widespread in bacteria and archaeal heterotrophs. Based on this evidence alone it could be argued the potential for direct assimilation of NO3 is high. However, before we postulate or conclude on this basis we need to consider more common metabolic processes as well.

    (3) A commonly found and widely documented metabolic process denitrification is a respiratory process induced by nitrate (used as an effective electron acceptor with electron donors being NADH, ferredoxin and flavodoxin) to created ATP (Nar system) is carried out under anaerobic conditions hence repressed by O2 but insensitive to NH4. I am convinced of this process and hence not debating this process.

    (4) Often called fermentative or DNRA process, the periplasmic dissimilatory NO3 is not repressed by O2 or NH4. This metabolic process is simply a redox balancing exercise. Compared to the numerous studies on N-immobilisation, DNRA studies have received relatively low attention from soil scientists. However, this process is being increasingly researched and documented lately but as a stand-alone study.

    (5) From my extensive review, I do not have any current doubt about the ability for soil bacteria to directly assimilate NO3. However, judging by other dominant and low energy demanding metabolic processes (e.g. DNRA) in soil and in the absence of DNRA consideration in many 15NO3 bacterial assimilation or immobilisation studies I am yet to be convinced that direct assimilation does occur in the presence of NH4. I do agree with Karolina and David that NH4 is less mobile than NO3 and hence in soil microsites the only bacterial N source may well be NO3. However, if such a situation does exist the question is whether DNRA process takes effect before direct assimilation of NO3.

    (6) Many research papers on NO3 immobilisation, including 15N works have failed to account for the DNRA process. It may be a difficult process to isolate in a dynamic soil bacterial/fungal metabolic environment. Judging by the high bacterial preference to NH4 there may be no opportunity for NH4 to accumulate by a DNRA process, particularly in an NH4 limiting microsite environment. Therefore monitoring NH4 chemically with time may not yield much.

    (7) Despite the above difficulty I recommend DNRA be one of the key components of every 15NO3 direct assimilation soil studies.

  • Katherine Vammen asked a question in Publication:
    How to get a specific publication

    I would for example like to download this publication

    Role of environmental factors and toxic genotypes in the regulation of
    microcystins-producing cyanobacterial blooms. Microbial Ecology

  • What hyperspectral imagers are available on satellites?

    Would hyperspectral sensors be able to detect and map coastal bottom features?

    Michel Verstraete · The South African National Space Agency

    If you are willing to consider airborne rather than satellite data, refer to the AVIRIS instrument operated out of NASA JPL:


  • Teodoro S Kaufman added an answer in Free Software:
    Free software for calculation of pKa. Any help?

    I will appreciate being informed about free software, able to calculate pKa of smal organic molecules from their structures. Thanks

    Teodoro S Kaufman · Instituto de Química Rosario

    Dear Colleague, Thank you for your answer.

  • Go J Yoshida added an answer in MDCK:
    Why aren't A549 lung cells used for influenza plaque assay?

    I am trying to determine viral titer and we do not have MDCK cells. My logic tells me influenza replicates in lung cells and not kidney cells and yet MDCK has been established for many years. Why is this so? Can other cell types (i.e. lung cells) be used for plaque assay?

    Go J Yoshida · Tokyo Medical and Dental University

    A549 cell line was established from lung adenocarcinoma tissue and the signal transduction is totally different from normal airway epithelial cells and alveolar epithelial type I and II cells. In particular, A549 is famous for the silencing CD44 expression, which is essential for the binding to ECM components such as hyalronic acids. To better understand the Influenza biology, the glycobiology is essential, so that CD44 expression should be positive in the cell lines in the research of interest.

  • Eddie Seva See added an answer in Social Statistics:
    Are the survey data reliable for researching predispositions and social concerns?

    What about the effects of false consciousness and mis-recognition?

    Eddie Seva See · Bicol University

    I believe it depends on the validity and reliability of the data you collected which arise from the validity and reliability of your data-collection instrument.

  • Tushar Kanti Ray asked a question in HIS:
    How do Science and Spirituality Concur?

    They do concur. In fact, they are complimentary to each other, and are essential for the development of full potential of a person. Cultivation of one without the other makes a person handicapped. An intellectual man lacking in spirituality is like a legs-amputee on a wheel chair, and a spiritually competent man without scientific insights is like a blind man with a white cane. Here is the story of two such young men lost in a dense forest, and how they came out of this depressing situation upon meeting and joining their hands.

    A Tale of Two Handicapped Youngman:

    I am about to tell you an interesting tale

    Of two handicapped young men

    Drawn to each other on first meeting

    Not due to love at first sight

    But due to imminent mutual interests

    Instantly flashing in both mind on contact ---

    And the enlightening story is detailed as follows:

    One man is legs-amputee on a wheel chair

    Calling himself as Science by name,

    The other is childhood-blind, strong young man

    Calling himself Spirituality, and

    Amputee sensed Scientist beforehand from afar

    With his supernatural senses

    Thus they met in the dense forest being lost:

    Both figured out what needed from the other

    And agreed even prior to discussion.

    Then Science sat on the shoulder of Spirituality

    With his eyes serving as their guide,

    And started fast to get out of the dense Forest

    Leaving the sun behind and go toward east

    Since the village of Science lays on east-side

    Hoping to reach there before sundown.

    Along their escape route they began to enjoy

    Everything akin to reunited soulmate

    With the acute senses of Spirituality bound to

    That of Science’s clear-vision around -

    Seeing Sun's game of hide-and-seek in the forest

    With dancing greeneries, sparkling holes

    Echoing duck-flights, humming birds and bees

    Beehives, monkeys and cuckoos on the trees

    Both of them enjoyed all and much more --

    The skilled handyman shared life-experiences too:

    Spirituality said he had a secure blissful life

    Until this event, getting lost and meeting Science

    But his briefly lost bliss is back again --

    Science noted, he's at peace now but suffered prior to

    From age five after losing both legs

    And his depression got worse and worse with time

    Thanking God, he is at peace again!

    There is a similar story told by a blossomed Lotus:

    Until blossoming out it was blissful

    Since birth in deep mud along its upward journey

    It had ample fun growing and swimming the calm water

    In peaceful tranquility

    While its soul enjoyed the bliss within

    But bliss gradually vanished and anxiety took over

    Soon after it started blossoming above water!

    Showing both survival Science and Spirituality concur

    And essential for a fuller life.

    Thus it should be noted- -

    All soul fall into this category

    We are born to learn from the school-of-life

    How to use our very mind-body-intellect properly

    Always maintaining a balanced-state

    With an open-mind and an open-heart

    To enjoy a peaceful life in mind-body-spirit harmony:

    This is indeed a categorical Truth, not an allegory!

    - - - - - - - - - - - - - - - - - -

  • Go J Yoshida added an answer in Melanins:
    Do I need to keep the melanoma cell (B16F10) in starvation media before drug treatment for a melanin content assay?

    I am planning to do a melanin content assay using B16F10 cell line but I am not sure whether I should put it in starvation media before drug treatment.  

    Go J Yoshida · Tokyo Medical and Dental University

    Growth factors or cytokines which influence on the activity of MITF should be removed before the addition of drug screening. Just the removal of serum, I mean that you change the serum-free medium, at least 3-4 hours before the experiment, is also useful. 

    Good Luck!!!

  • Michel Verstraete added an answer in Climate Data:
    How would one calculate or use a measure of Temporal Variability for Climate datasets such as Worldclim?

    It will be helpful if anyone can post papers which discuss the temporal variability of climate data obtained from worldclim.

    Michel Verstraete · The South African National Space Agency

    There are a number of statistics and indices that could be used to estimate some measure of temporal variability. Any good book on time series analysis should provide ample suggestions, if not direct answers.

    To elicit more specific answers, please refine your question and explain your goal:

    - do you want to compute a single overall measure?
    - do you wish to establish the presence of a trend?
    - are you interested in exploring the existence of specific frequencies?
    - will you also require an estimate of the reliability of the result?

    There is no such thing as a 'best' measure of temporal variability: it all depends on what you want to achieve, on the spatial and temporal scales of interest, on the degree of accuracy required, on the acceptable sophistication of the methods, on the availability of computing resources (hardware and software), on the deadline for coming up with an answer, etc.

    Note also that Emily S. Acheson of University of Ottawa asked a similar question in April 2014: see


  • Claes Richard Fredö added an answer in Fluid:
    How Modal analysis for sloshing tank is performed?

    I want to create a simulation in Ansys to get natural frequencies of sloshing tank, should i perform modal analysis for fluid only or for tank coupled with fluid in it? and how to get natural sloshing frequencies ? 

    Claes Richard Fredö · Qring Technology Intl. AB


    If your fluid is heavy and your tank structure is weak, expect them to interact. That said, such interaction greatly complicates analysis so I would start by making some sensible estimates to see if I can avoid having to deal with such interaction.

    You can likely ignore fluid-structure interaction if your wet stucture natrual frequency lies 3x higher than the sloshing frequency of interest.

    To estimate the wet structure mode, simply add the liquid specific density to your structure density, i.e. assume that all the liquid is moving with your structure. This will overestimate the effect from the liquid on the structure, but it will provide a quick way to see in what frequency ballpark is your problem. 

    The sloshing frequency can be estimated by modelling the liquid as a hard walled acoustic case with a special boundary condition applied for the free surface, the so called free surface stiffness, in which the free liquid surface has the boundary condition rho*gravity. See here for explanations,



    http://www.ata-e.com/downloads/software/Hydro_Users_Guide.pdf (eq 30)

    If you need to consider fluid-structure interaction, you need to be aware that analysis of fluid structure interaction provides complex modes and that complex modes is an end result.

    If you need modes for further analysis, you must either to cheat a bit as is done in Nastran's wet mode calculation to get real modes or, use modal substructuiring where one domain is in vauo structural and the other domain is hard walled acoustic with the free surface stiffness considered.

    That said. the above applies only for linear analysis, i.e. wave heights negligible in comparison with problem physical dimension. 

    If you cannot find good Ansys example cases for the above, you might consider switching solver for the job. There is a very good freeware FE sover called Code Aster that handles both the uncoupled and fully coupled cases that has a special free surface element (PESEANTEUR). There is an example here that can serve also a reference solution for a test case. http://www.code-aster.org/V2/doc/v10/en/man_v/v8/v8.21.101.pdf .

    Code Aster has also a set of very advanced routines for the calculation of wet modes if this is of interest to you.

    Good luck


  • Fabrice Gankam added an answer in Autophagy:
    How can we detect LC-3 II band with western bloting ?
    I to detect LC3-II by western blot but it's not working. I am wonder how to develop the optimally conditions, lysis buffer, gel running & blotting condition, buffer and antibody.

    I work on the HL-60 cell line, LC-3 II antibody from Abcam and I will try with Hela cell line for positive control but it doesn't work.

    try novus rabbit LC3b it works perfect

  • James F Peters added an answer in Edge Detection:
    Can anyone help me to get the Matlab code for edge detection to 3d model?

    I want code in Matlab help me to detect the edge of 3D model object, and be thankful for your help.

    James F Peters · University of Manitoba

    This is a good question.

    An answer to this question is given in

    B.D. Nhan, High Redshift 21cm Line Simulation Data Visualization with Canny Edge Detection, B.Sc. thesis, University of California Santa Barbara, 2010:


    See Section 4.4,  starting on page  40, for an introduction to a 3D Canny edge detector. The mathematics for the 3D gradient is given in Section 4.4.2, page  42.    The basic approach to develop an extension of the Matlab edge function.

    A more complete answer to this interesting question is given in

    Per M.A Eriksson, Segmentation of Carotid Arteries from 3D and 4D ultrasound images, Report, Linkopings Universitet, 2002:


    This report presents the use of the 3D Monga-Deriche-Canny edge detector.  See Chapter 4, starting on page 37.

  • Paul Koszarny added an answer in Theology:
    Without Knowledge Of First Cause Can Science "Correctly" Predict Effect?

    If so how would we know?

    I am beginning to see where is the flaw in your theory. But I want to give only an evidence  that I CAN CORRECTLY PREDICT EFFECT without knowledge of first cause soon. 

  • What is Log transformation and why we do it in gene expression analysis?

    Hello Everyone I am a beginner in world of science, I want to know that what is Log? what is log transformation? and why we do it in gene expression analysis?



    Yuan-Yeu Yau · Northeastern State University

    Please see below from "Seven tips for bio-statistical analysis of gene expression data" [ https://www.biogazelle.com/seven-tips-bio-statistical-analysis-gene-expression-data ]:

    Always log transform your gene expression data

    Gene expression levels are heavily skewed in linear scale: half of the data-point (the lower expressed genes) are between 0 and 1 (with 1 meaning no change), and the other half (the higher expressed genes) between 1 and positive infinity. Consider the case where the normalized expression levels are 0.1 (A), 1 (B) and 10 (C) for 3 samples (A-C) under study. Intuitively, we understand that sample A has a ten-fold lower expression compared to sample B, and that C has a ten-fold higher expression compared to B. However, in linear scale A and B are much closer (similar) to each other than B and C (0.9 units versus 9 units). A parametric statistical test will therefore be biased and not appreciate that A and C are equally different from B. Upon log transformation (I use base 10 here, but any base will do), the distance between A and B, and between B and C becomes equal (1 log10 unit, as the log10 values of A, B, and C are -1, 0 and 1). Log transformation makes your data more symmetrical and therefore, a parametric statistical test will provide you with a more accurate and relevant answer.

  • Libor Hadáček added an answer in Fuzzy Control:
    What is the best way to create membership functions for two different perspectives?

    I have created a fuzzy control file (fcl) that has three membership functions, service, room and food.

    Given the input values for service, room and food, I expect to retrieve a trustWeight value. What this is for is to identify how much importance I should give to someone who has specified his inputs.

    Currently, i have the following rules:

    RULE 1 : IF food IS bad OR service IS poor OR room IS poor THEN trustWeight IS less;
    RULE 2 : IF food IS excellent OR service IS excellent OR room IS excellent THEN trustWeight IS high;

    What i want to be able to do is this: Based on the input from different types of people, different weights should be allocated.

    For example when a businessman rates a room(5/10) and a familyman rates a room(5/10), the output shouldn't be the same I need to be able to have rules that's like the following:
    If its a familyman, and the room is bad then trustWeight is less
    If its a businessman, and the room is bad then the trustWeight is high
    Based on the type of person (and other fixed factors) I should be able to get differentTrustWeight results.

    Hence for two different perspectives (businessman and familyman), is this possible to be done? If so, how can I do it? What approaches or suggestions would you make?

    I am using jFuzzyLogic library for a FL project with Java

    Libor Hadáček · VŠB-Technical University of Ostrava

    I was thinking about the question how to decide between businessman and family man. What happen with suggested rules, when businessmen will be on holiday with family or family man is on a holiday four times a year? A question should be how many times a year was an interviewee accommodated in a hotel. Answer on this question is possible to evaluate and should be a next input.

  • Mojtaba Khomami Abadi added an answer in Weka:
    Which tools are among the best suited for doing feature selection with applying the mutual information?

    Hi guys,
    I'm gonna to do the feature selection preferably using the GUI tool.
    I also want to apply mutual information in feature selection. Hence, which tool is the best suited for it and do you have any suggestion for a tutorial? I have tried to use weka by referring from youtube at this moment, if you can give suggestion for any other better solution, you are highly appreciated.

    Mojtaba Khomami Abadi · Università degli Studi di Trento

    I believe the FEAST toolbox is one of the bests, given the unified implementations of many SOA methods.