Science topic

Connectivity - Science topic

Explore the latest questions and answers in Connectivity, and find Connectivity experts.
Questions related to Connectivity
Question
3 answers
Diagnositc tests in low endemicity (low prevalence) areas may lack the required sensitivity. Among several screening steps, exploring social networks may be of value. We are currently testing this approach with schistosomiasis.
Relevant answer
Answer
Hi, Carlos
I do remember our discussions on "social connectivity". Social contact data could be useful to predict infection risk (or levels) from a limited test data (e.g. sparse population sampling). Still you need to supplement it with other "real" data.
As for "breakpoint" for transmission, it's an attractive idea that appears in simple transmission models, but I don't know whether it holds (or how to assess it) in real environment.
Question
5 answers
   
Greetings,
i am asking about the simulator that can easy to simulate the VANETs to internet connectivity and the tools required to measure the performance of the simulated network.
i have an idea about ns2 but i found  other simulator named Mobisim . can any one show me how to simulate this network .
Relevant answer
Answer
Not difficult, try to find online, there are many tutorials and docuemnts are avilable on MobiSim and NS-2.
Can anyone recommend empirical studies in the area of standards/standardization (process standards, technological standards etc.)?
Question
39 answers
We are looking for publications on empirical studies in the area of standards/standardization (process standards, technological standards etc.). In particular, for those, which have an emphasis on the connection between standardization and innovation or standardization and routines.
Relevant answer
Dear Andrea, all, standardization evokes the idea of keeping thing the “same”, while innovation suggests the idea of “newness”. For this reason, standardization and innovation are often perceived as antithetic. However, standardization and innovation have a more complex relationship. For example, when taking into account the time dimension, standardization and innovation are strictly interrelated: the standard of yesterday is the basis of the innovation of today. Further, the innovation of today can be the standard of tomorrow. In this sense, the standardization and innovation influence each other with positive feedbacks. Another example, is the certification that increasing confidence may facilitate the commercialization of inventions. Much research is done in the standardization field (among others see Euras http://www.euras.org/ ) but somehow not well known by other researches. However, well known economics are turning their attention to this issues. For example Acemoglu et al. (2012) theoretically show how innovation and standardization can both be (competing) engines of growth. http://economics.mit.edu/files/8623 please find below some links to papers (including my early contribution) that may be of your interest: Economics of standards http://webarchive.nationalarchives.gov.uk/20070603164510/http://www.dti.gov.uk/files/file11312.pdf http://www.gov.uk/government/uploads/system/uploads/attachment_data/file/461419/The_Economics_of_Standardization_-_an_update_.pdf Standardization and innovation http://www.nesta.org.uk/sites/default/files/the_impact_of_standardization_and_standards_on_innovation.pdf http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2566158 kind regards Cesare Dr. Cesare Antonio Fabio Riillo Researcher Research Division STATEC (National Institute for statistics and economic studies of the Grand Duchy of Luxembourg) / ANEC (“Agence pour la Normalisation et l'Économie de la Connaissance”)
Question
25 answers
How we can establish "IS - A" relationship between to entities / concepts identified from text data. For example, if I have a concept / NE "broadband connection", how I can connect "broadband connection" IS A "net connection" ?
Relevant answer
Answer
NELL derives is-a hypotheses from patterns.
Here is a paper on the technology.
In your case you could go for the
pattern
<noun phrase in plural>
such as <noun phrase in plural>
A little bit of a problem is that
the nouns might be compound ones,
so you might have to use a parser
to extract the noun phrases.
Regards,
Joachim
Question
5 answers
For a given (unweighted) graph G(V,E) with an integer d > 1. How to find a connected subgraph H of G with maximum |V(H)| and satisfying ∆(H) ≤ d (i.e. subgraph H is connected with the maximum number of nodes in which degree of node in H is bounded by d).
Cound anyone please suggest an approximation algorithm to find the subgraph H with satifying above mentioned constraints?
Relevant answer
Answer
Ram, I recently found very good Algebra behind Graph Theory. Perhaps you should have a look at their approach. It is more complex in terms of language, but perhaps they have already done a lot there. 
Question
5 answers
can any one hlep on Advantage and disadvantage of Anti-series connected IGBTs?
Relevant answer
Answer
Mr. Shankar, anti-series connection has the emissors of two IGBTs connected together.
Mr. Jagabar, anti-séries connection permit to implement dead time between the turn-on and turn-off of another switch and this bi-directional switch. In this case two gate drive is needed. Besides only one isolated supply to drive is necessary.
Question
9 answers
I am trying to simulate a three phase system in which power is to be transferred to the grid from photovoltaic system and no three phase load is  connected at PCC.I wish to maintain the reactive power transfer to zero and maintain system at unity power factor.
(Most of the research papers I have seen have load connected in between)
Let me know of any control algorithm which I can use to achieve this.
Relevant answer
Answer
You can see this study:
I hope that it would be useful for you.
Question
17 answers
Can a power generation  plant be directly connected to transmission lines instead of installing new lines to feed the S/S?
Relevant answer
Answer
All the above comments are relevant. Just to add more, before you add any generator to the system, you need to check the capacity of the lines, thermal limit, short circuit capacity and for control purposes, the damping limit is another important criteria. Another important aspect is that of protection. You cannot just connect a remote plant to your system without properly protecting your generator through relay protection and circuit breakers.  
Question
5 answers
In an EEG study, I am trying to compare the brain networks of 3 motor tasks while functional interactions are measured by 3 estimators coherence (Coh), imaginary part of coherence (iCoh) and partial coherence (pCoh). My results show that for task 1, more connections are achieved by Coh (denser network), for task 2 more connections are achieved by iCoh and for task 3 more connections are achieved by pCoh. Regardless of other steps and methodological considerations of this research, is there any explanation for this behavior of connectivity estimators? Is there any reference regarding this issue?   
Relevant answer
Answer
Thanks for your answer.
Brain connectivity estimators measure the pattern of interactions (functional/effective) in the brain.  http://en.wikipedia.org/wiki/Brain_connectivity_estimators
There are several connectivity estimators and in my question I asked about the behavior of Coh, iCoh and pCoh. Since I am dealing with 3 motor tasks with similar nature, I expected to see for example more connections are obtained by Coh for all 3 tasks compared to the network estimated by iCoh or pCoh. However, I've seen something else as explained above. I couldn't find any reference regarding such issue.    
Question
77 answers
I am designing an LC filter for an inverter. If I design L and C values without load (RL) its fine, but after connecting load (RL) the effect of filter is changed. What should I do for having effect of load on filter values is less.
Relevant answer
Answer
As I understand, you are designing a low pass LC filter for the ac voltage at the output of an inverter.
Calculate L to have about 3 to 5% fundamental voltage drop at the rated current. Now select C as per the cut-off frequency designed. In this way, effect of load will be minimum.
Also have a proper design of the L such that it does not saturate. The fixing clamps (across the air-gap) must not be of iron, which is a common mistake.
Question
4 answers
Currently we are trying to locate clandestine (illegal) water connections by acoustic location of plastic pipes in Moquegua (Peru). Are there any known experiences of this kind ?
Relevant answer
You can try to find the information of your interest at
Good luck 
Question
8 answers
Hello Every body,
I am generating 3Vp-p from DAC inside PSOC 5LP. It looks very nice as long as i do not connect it with bridge (in order to excite the bridge). When i connect it, the voltage drops from 3 to 1/3 of that. I tried to place a voltage follower externally at the output of the DAC but as a result my signal becomes very noise and drops too (but not much).
I am failed to find the reason. Can any body have any idea?
Looking forward for your suggestions.
Regards
Awais
Relevant answer
Answer
Hi
I think that your first instinct was right, you must be draining too much power from the DAC, but you should still verify that. Try placing resistance at the output and measure the voltage. Look in the output impedance of the DAC and see that it respect the voltage divider.
As for the follower circuit, make sure that is has a nice clean voltage supply, and don't use a 741 OP-AMP, this hardly work in the lab, so it has a hard-time in real-life.
Finally, make sure that the frequency of your DAC is well within the bandwidth of the OP-AMP
Good luck
Question
1 answer
Is the ER associated with plasma membrane different from that of Rough ER associated with the nucleus?
Relevant answer
Answer
Dear
  Up I know your answer is " YES"
Question
1 answer
I want to simulate a PV inverter Grid connected system. I have done the (PV,DC-DC boost converter, MPPT and inverter circuit). Now I need to stabilize the DC-link voltage to 400. Anyone could give me any suggestion because when I connect all parts together the system doesn't work correctly.
Relevant answer
Answer
Dear Salih..I have worked on single stage grid connected pv system and with my experience it is always better to check loop by loop control. I mean check whether the inner current loop is working or not by giving some arbitrary referene current value with all other control disabled and then check whether the inverter is able to iiect it or not. Then go for the voltage loop and once it is done complete it with the mppt loop.
Regards
Question
9 answers
Is there an algo for finding connected components in SPARSE MATRICES?
Relevant answer
Answer
For connectivity, you can take a look at Tarjan's algorithm to find connected components in a graph, regardless if it is directed or undirected. 
Question
4 answers
Hi,
I have a set of locations on earth (100 - 1,000), given with latitude and longitude values. I want to create a network out of them by connecting those locations to additional "hubs". The overall distance in this network should be minimal. I want to use the haversine function as distance. Any suggestions how to infer the best locations for these additional hubs? How could I do this within reasonable compute time?
Thanks in advance,
Stefan
Relevant answer
Answer
Computation time/expense not sure !!
Read it when I was processing WGS-84 sentences.
Question
2 answers
What magnetic properties are of interest in connection with a study of surface properties of Heusler or Half Heusler nanoparticles?
Relevant answer
Answer
Maybe the ones you are looking at could be topological insulators. If your nanoparticles have a surface, or better, if they have a bulk, there may be different conducting phases around it connected with their spins.
Question
1 answer
I want to know that what would be the fastest fiber optic network card for a pc ? and does those things offer the actual speed mentioned? any one who uses a fiber optic network card please help me. something similar to this.
Relevant answer
For the PC card  a good model works at 1320nm Low Pro, PCI combo card 10/100Mbps RJ-45 & 100Mbps ST MM.Low Pro, PCI combo card 10/100Mbps RJ-45 & 100Mbps ST MM. ITEM: AFP2200L can be found at:
For the optical cable : 62.5/125 micron cable for fast ethernet, fibre channel, ATM and gigabit ethernet applications where protection from toxic and corrosive gases is critical
regards
Question
4 answers
   
i am investigating neurodegeneration in different pathological states so i would wish to also do structural connectivity analysis.
Relevant answer
Answer
Diffusion tensor MRI?
Question
31 answers
In the Riemannian geometry the distance between any two points is defined as an integral along the shortest curve (geodesic), connecting the two points. Let the Euclidean geometry be defined on two-dimensional plane L as a Riemannian geometry. Let now we make a hole in L and obtain the plane Lh with a hole. Then the plane Lh will not be imbedded in L isometrically. Does it mean, that the Riemannian geometry is inconsistent? Or following mathematicians, one should consider the Riemannian geometry as a consistent geometry, provided one considers only convex pointsets.
Relevant answer
Reimannian geometry (RG) is a math theory, which include Euclidean and other axiomatic/synthetic geometries formulated in the language of differential calculus. RG is not an axiomatic system and hence it is not very correct to apply to RG the term "inconsistency" in the sense as this concept is rigorously formalized in math. logic.
The notion of distance between two points is not defined for a generic Riemannian manifold. For instance, such is Euclidean plane with one point removed. Moreover, the notion of distance is irrelevant in RG.  Y. Rylov find "inconsistency" of RG in the fact that Riemannian manifolds do not behave as metric spaces (MS). But this only means that RG and MS are just different non equivalent generalisations of Euclidean geometry. So, the quesation is, which of them is adequate for physics. Up to now no arguments in favour of MS are known, while with RG physics  feels at home. For instance, classical mechanics in Hamiltonian setting as a pure RG.
Finally, the Levi-Civita connection, which is respopnsible for parallel transport, is an  immanent property of the metric tensor as, say, the curvature tensor does, etc. In other words, parallel transport is not something introduced artificially or by hands but a mechanism naturally defined by the matric tensor. So, I do not see here any "suppresion" or "inadequacy".
Frankly, I do not understand what is the motivation for this discussion. If RG is "inadequate" for somthing in physics or math this point should be indicated.RG has so deep and brilliant aceivements and fits so well all "experimental data coming from physics and math that put it in question would be even worther than putting in question the conservation energy law, which, by the way, is rigorously formulated properly in terms of differential geometry.
Question
5 answers
i want to create a wireless sensor network with a source node,intermediate nodes and sink node with multiple paths from source to sink through intermediate nodes. The problem which i am facing is that when i want to connect more than one intermediate node with sink then it gives an error that "sink.network.in is already connect" means i can make connection of only one node with sink node, please help me to learn to make multiple connections with sink node.
Relevant answer
Answer
This has nothing to do with MIMO, this is just because your sink isn't correctly defined. In your sink class, rather than just having a single gate, make it a vector:
simple Sink {
gates:
input in[];
}
You can also explicitly specify the size of this vector (i.e. put a maximum number of incoming connections); you can also add the @loose keyword after in[] or in[N] to allow inputs to be unconnected. Similarly inout instead of in etc.
It is all documented at the attached link.
Question
7 answers
Let G(V,E) be an weighted, undirected, K-connected graph. Let N be subset of V. What is the best way to find the smallest connected subgraph G'(V',E') of G(V,E) such that N is a subset of V' and induced subgraph G(V',E') is (K-1)-vertex connected?
Relevant answer
Answer
In addition to the material pointed out by Prof. Thomas Korimort, Please have a look at the following links:
Hope that these references will be useful to you..
Question
4 answers
If you originally shared by all neurons at excitatory and inhibitory, it significantly limits the ability of a neural network with a given structure. Why not use a one type of neurons. Are there any known electrical models of neurons, providing both intensification and weakening of synaptic connections?
Relevant answer
Answer
One should be quite careful to distinguish artificial neural networks and models for neurobiology. Cf. here, http://bluebrain.epfl.ch/,  for instance, for information on an effort  to describe the latter. 
Question
2 answers
How can I fix a leak from the pre-column side that is connected to injector?
Relevant answer
Answer
See attached file,might be useful.
Regards
Abhishek raj
Question
1 answer
It is connected to a hydropower plant with a 100kW Francis turbine.
Please consider the attached document for pictures of the governor and turbine
Question
4 answers
Consider a linear connection on a manifold with respect to a basis. We obtain that its components with respect to the basis are zero. What does this result mean?
Relevant answer
Answer
It means covariant derivative on manifold along any curve is zero. So every curve on manifold is parallezable. or geodisc.
Question
13 answers
Based on continuous habitat suitability values (from 0 to 1) for a butterfly species, I'm comparing different conservation strategies, that would output different possible networks of protected areas.
Based on the assumption that suitable habitat will be destroyed in unprotected areas because of high anthropic pressures, I would like to calculate a connectivity index for remaining habitat patches, based on different conservation scenarios. This connectivity index should take into account the distances among remaining habitat patches, but also their habitat suitability values.
Does such an index exist? If so, how to compute it?
Relevant answer
Answer
Question
2 answers
I have a compound in which a pyrophosphate group connects two lipids protected by BOC (butoxy carbonyl).  I want to deprotect the BOC group using TFA. So, is pyrophosphate stable to acidic conditions like TFA?
Relevant answer
Answer
Thank you for your suggestions. I will post the results soon.
Question
4 answers
I am calculating the attenuation of an LVDS cable by observing the voltage at both the ends using a CRO when connected to a readout. 
I am using the formula attenuation = 20 log10(Vout/Vin). Is this formula correct and are negative attenuation values possible?
Could somebody help please.
Cheers,
Shri
Relevant answer
Answer
Your equation relates output to input, therefore indicates "gain" in dB...  A negative gain equates to an attenuation...  e.g.  -20 dB gain is same as 20 dB attenuation...
Question
6 answers
We transform source current (Is) of Single Phase Active Front End Rectifier into Id and Iq. What should be the nature of Id and Iq? Is it possible for Id and Iq to be negative?
Relevant answer
Answer
The Park transform is just a mathematical tool to simplify the control/calculations of AC signals. The Park transform changes an AC signal with a specific fundamental frequency to a rotating frame with that fundamental frequency. the quantities in this reference frame are dc quantities. This makes control/calculations much easier.
Since in most cases the fundamental frequency is fixed (50 or 60 Hz), the transformation from AC to 'DC' signals can be done rather easily.
For motor control the Id current is used as the magnetization current, for permanent magnet motors it shall be controlled towards zero. The Iq current is the torque related current. This current can be positive and negative (motor or generator operation).
In a rectifier this separation can also be made but than with active and reactive power.
Question
3 answers
How can one implement a program to compute geodesic distance on the Riemannian surface in MATLAB. Any available toolboxes?
Thanks for your help in advance.
Relevant answer
Answer
Hi, concerning distance on an ellipsoid you can have a look to the  following link:
Question
6 answers
When iam keeping the PV-array to the load the voltage of pv is fluctuating from -x to +x with SRF nd MPPT applied to it for grid coonected mode
Relevant answer
Answer
if you are using a standard "approved" grid connect inverter it normally adjusts its power output to the grid to get the maximum power from the array and it stops operating the grid is disconnected.  If you are using a voltage source inverter it can be operated and control its power and reactive (P & Q) but it cannot deliver any more power than the array can supply.  When it disconnects from the grid it has to change its control system to hold constant ac output voltage but the power is determined by what load is connected.  If there is no load it should produce a sine wave output and the voltage on the array will rise.  If you add load the array voltage will fall as more current is drawn.  But if you increase the load power beyond what the PV array can supply then the PV voltage will collapse and the output voltage will be distorted.  Normally grid connected inverters which continue to supply power without the grid have a battery on the DC side to provide power when the array output is less than the load.
I suggest you look at the voltage current characteristics of PV arrays.  They become constant current sources when the load increases.  A battery like a car battery produces about 13V and will produce 100s of amps into a load with only a small voltage drop, at least until it is discharged.
The articles suggested by Saad Motahhir should introduce you to characteristics of PV arrays.  Look at figure 2 the I-V curve for different levels of solar radiation.
How to obtain a good thersholdes for new parametere that propose in attach article for my grid?
Question
1 answer
I want to improve THD method in detection of islanding detection,so I want use a new parameter like H that use in attach paper, it propose for a grid voltage of 0.38 kV but my grid is different and 100kW that connected to 13.8 kV,so I need to set a thersholdes for H parameter,could you help me and tell how dose it choosen?
Relevant answer
Answer
consider then ratio of 13.8/0.38 . Multiply this value with the existing value of H. that value of H may help you in your design.
Question
6 answers
Hi guys,
I would like to know how to properly use the Pefect Loop in order to pick up ultrathin sections and release them well oriented onto a formvar slot grid.
Thank you very much!!!
Francesco
Relevant answer
Answer
Dear Francesco,
In addition to the suggestions from Wolfgang, I've personally had good experiences with the following method (though it requires quite stable hands):
pick up a formvar slot grid (with glow-discharged carbon coat) with N5 (crossover tweezers) and hold it i your left hand (or right hand if you're left handed). pick up the ribbon with the perfect loop.
now tilt the loop towards you while looking through the binoculars of the ultramicrotome
and you should be able to see the ribbon in the perfect loop.
approach with the slot grid to the upper side of the perfect loop (film facing the droplet with the ribbon) orient the slot of the grid parallel to the ribbon and touch the droplet with the grid. (see picture) This should transfer the ribbon to the grid.
best wishes and good luck!
Question
9 answers
Hi, I want to connect a wireless sensor network that simulate in omnet++ to an SDN controller (in mininet) and control my network with SDN controller. what is your opinion about it? How can I connect these?
Relevant answer
Answer
Just an addendum, in the design of your architecture, consider that in OMNeT ++ up to the present moment according to the work below (which I have for personal reference, so far I have not found any additional reference), openflow support is in OpenFlow Switch specification 1.0.
I suggest in case of further doubts, get in direct contact with the project quoted, maybe they can help you better.
Question
5 answers
I am working on Transformerless inverter for grid connected PV. in this context i simulated a H5 inverter for which to connect to grid and inject either active or reactive power. how to do that . Give me understanding of the same.
Thank you
Relevant answer
Answer
Hello Janardhan,
To inject active power you just have to inject a current in phase with the grid voltage.
To inject reactive power you need to phase shift the injected current with respect to the grid voltage.
Thus, by controlling the phase and amplitude of the injected current you can control the active and reactive power injected into the grid.
Regards,
Michalis Florides.
Question
3 answers
Hi,
the classical PTAT cell is reported in the attached file ("classical ptat").
According to you, if I substitute PNP BJTs with diode connected NMOS (like in the other attachment "modified PTAT"), is the configuration suitable?
Thanks everyone
Relevant answer
Answer
Hello,
check the references at
Seems it can be done in CMos as well as MOS without the C.
wikipedia is your friend !
How can IOT (Internet of Things) and NoC (Network on chip) be connected?
Question
40 answers
what is the common interests and topics in IoT and NoC that can be connected and are suitable for research? thank you in advance.
Relevant answer
Answer
Dear Yasin,   I here attach you some related samples. Regards. http://www.ijeecse.com/94.pdf http://www.cfaed.tu-dresden.de/files/user/jcastrillon/publications/160418_castrillon_dataflow4IoT.pdf http://people.duke.edu/~mp275/pubs/IoT_CODESISSS.pdf
Question
3 answers
In SDN, How can I run multiple Floodlight controllers in one topology?
If I need to monitor the behavior of multiple flood light controllers in one topology, how we can connect multi controllers together using Mininet?
Question
4 answers
while applying graph theory, they always study in removing nodes, I wonder how does it fare, specifically. Did it  operating by computer under a certain model? And if it possible to add nodes rather than remove them.
Is it possible to develop it into  three-dimensional conditions? Like migration research?
Relevant answer
Answer
Hi Qian,
I see 3 things being discussed here:
  1. The previous response is correct in that the typical application is a planar undirected graph. However, some applications are highly directional (e.g., dendritic networks that represent hydrologic connectivity). 
  2. Nodes in spatial graphs are typically two-dimensional and represent a habitat patch of particular shape, quality etc. The nodes are connected by links between boundaries or directly to one another (points).
  3. There are models and software that allow you to examine the graph improvement and explore the overall effect of both adding AND removing nodes to the network. One package with these capabilities is Conefor described by Saura and Torné. 
I hope this helps.
Question
14 answers
I am interested in exploring the connection between internationalization strategies of HEIs and university culture. What I have found so far, is just one brief literature review and a couple of dissertations. Can you recommend any references that use the two variables ( internationalization and university culture) in one context? 
Relevant answer
Answer
Hi Lela!
I would recommend you to look into various publications by Simon Marginson, He is on RG, click here http://shootingcupoche.com/profile/Simon_Marginson . He writes both on internationalisation /globalisation and universities as agents university culture in the contemporary developments and transformations. I have used his "glonacal" (global-national-local) model to try to understand some possibilities with MOOCs: 
Question
6 answers
Does anyone have experience with reaction time tasks using "wireless" EMGs that use bluetooth to connect to the computer?
I wonder wether bluetooth might be slower than the "old" cables. In our experiments we measure reaction times in miliseconds (ms), so this is really an important issue.
We need to set markers in the EMG raw signal.
I am not sure how it works.
Case 1:
The markers are sent to the bluetooth device. In this case sent via bluetooth. With delay the markers might be set to late.
Case 2:
The raw signal is sent "live" (with delay) to the computer, where the markers are set. In this case the markers might be set to early.
Relevant answer
Answer
Well, there is delay in any transmission, even in optical fibres. Question is how much. Transmission delay  should be specificied in the data sheets.
But I like to point your attention to another crucial item: Any port to peripherals (like Bluetooth) is served by a driver of the operating system, and when the driver is served by the CPU depends on the actual program task load situation. E.g., when you have enabled an online virus scan, the related disk activity can block the service of the Bluetooth driver. Same is true for stimulus generation on the screen; again, delays are possible. The PC together with WINDOWS is no realtime machine!
Werner
Question
2 answers
You will have to assume that the radio will at some point be partially or completely submersed, therefore creating connectivity problems.
Relevant answer
Answer
Attenuation of radio waves in water depends most on the frequency.  To work underwater, radios would need to use frequencies of 10 to 30 kHz,
See the attached technical report.
Question
5 answers
I am currently analyzing some RNA-seq data using weighted gene coexpression network analysis. In putting together some scatter plots I am curious if there is some interesting information in the kOut and kDiff connectivity measures. It has been difficult for me to wrap my head around their meanings. 
kTotal = whole network connectivity (adjacency)
kWithin = intramodular connectivity
kOut = kTotal - kWithin
kDiff = kWithin - kOut 
Relevant answer
Answer
Dear Caitlin
Lets check our understanding of these measurements:
1) kTotal - connectivity of the each gene based on its r-values to all other genes in the whole network
2) kWithin - connectivity of the each gene within a single module based on its r-values to all other genes within the same module
3) and 4) kOut and kDiff mathematical derivatives from 1) and 2)
So, let say WGCNA identified 10 modules, but kWithin for "Module 2" is the largest and obviously larger than kTotal. This suggest "Module 2" to be a core of the network, or more important. Let say You perform functional annotation of the genes in this module and will find them to be enriched in amino acid analysis. And Your study was dedicated to metabolic changes under some conditions. So You can make conclusion that Your condition strongly affects AA metabolism, and via it - whole network.
In contrast, high kOut can suggest that total connectivity is much larger that connectivity within modules, and I would say - reflects sort of network's stability under tested conditions. So a set of vertices with high kOut can be targets for annotation as hubs that determined this stability. And elimination of them (knockout mutations, for example) can break the whole network.
Does it make sense?
Question
4 answers
To operate driver circuit of Inverter module, i has to provide +15 V supply, so i want to provide it through an RPS. can i connect ground of dspace to 15V dc supply from RPS and Inverter common ground point.
Relevant answer
Answer
Thank you, for valuable answer
Dear Martin Schulz.....
Question
2 answers
I know the definition (Maximum E-state of an atom in the molecule), but I don't understand how we get a number.
Relevant answer
Answer
I've seen various electrotopogical indices but not this one. Thank you anyway.
Question
5 answers
Dear All,
I have attached one Phasor diagram (per phase) for grid connected inverter. I want to find the equation of Inverter out put voltage in terms of its dq components. Can you please clarify under the given circumstances, E = Ed+jEq or E=Ed-jEq and why?
The sheet I got from my superiors considers E=Ed-jEq but I do not know the reason of it.
Your expert help will be appreciated.
Regards
Aalok
Relevant answer
Answer
Looking at your document and your simple circuit, the only thing you know, the only constraint, is the sum of the voltages around the circuit:
E - IR - IXL - V = 0
=> I = (E - V) / (R + XL)
=> I = (E - V)(R - XL) / (R2 - X2L)
=> I = (R - XL)(E - V) / (R2 + X2L)
You can CHOOSE to have I in phase with V by noting the argument (phase) of the above and the phase of V. Thus resolving I into phase and quadrature components and ignoring the denominator of the above (it is only real), we find:
I = j(EqR - EdXL - VqR - VdXL)
+ (EqXL + EdR + VqXL - VdR)
Whereupon,
Theta = atan (Im I / Re I) 
= atan (Im V / Re V)
If we consider V to have zero phase, straight-away we can equate the imaginary part of I to zero and obtain EqR = (Ed - Vd)XL
.
You might specify other constraints: that the voltage and current be in phase across the resistor, that the power factor of V is matched and so on. Without some constraint, you cannot specify a relationship.
Question
3 answers
I have a doubt with the charging process of a Supercapacitor, because of small value resistance that it have, the current must be extremely high if I connect in a converter DC/DC with voltage mode control. I didn't do real experiment yet but I need some recomendations about how to charge a supercap.
Relevant answer
Answer
The simplest suggestion - serial connection with resistor (let's name it Rad).This resistor will limit current. to the value I=voltage/(R(sc)+Rad). Unfortunately all time/frequency dependent characteristics will change as well :(
Question
5 answers
I have planned to pursue research on network intrusion detection.
Can anyone help me on how to extract information on anomalous flow from a live network connection?
Relevant answer
Answer
If you know what normal dataflows look like, you can detect dataflows that do not comply with normal patterns.
Do you have an understanding of the normal dataflows of standard network protocols? That would be a good place to start.
On the other hand, I also suggest you take a look at honeynets. I find them more effective in detecting abnormal traffic.
Question
71 answers
I am looking for a free tool to use in ArcGis or a stand alone app that will calculate measures of habitat connectivity in a fragmented landscape. The project aims to use connectivity calculations to inform optimal ecological corridor design.
A number of tools are listed on this webpage though I am not familiar with any of them: http://www.conservationcorridor.org/corridor-toolbox/
Any advice on a nice efficient tool to use would be greatly appreciated.
Relevant answer
Answer
Hi Lui,
I think you should use GRAPHAB. It is a new software dedicated to landscape connectivity analysis. As conefor, GRAPHAB is based on landscape graphs but has a more user-friendly interface like a classic GIS tool.
To download GRAPHAB (Linux, MacOS X, and Windows) : http://thema.univ-fcomte.fr/productions/graphab/en-home.html
Moreover GRAPHAB has a forum where you can ask your questions here : http://thema.univ-fcomte.fr/productions/graphab/forum/index.php
Question
8 answers
See above
Relevant answer
Answer
You can define force-displacement relationship along with damping for NL link (multi-linear plastic) in SAP 2000. However it has only 3 Hysteretic models to define cyclic behavior and you have to select one of them depending on the material properties you are using for modelling. Make sure your input properties represent the material very well. 
Question
60 answers
CAPM is a good method to predict the cost of capital.In particular, how do you determine the expected market return (an important component of the risk premium), in connection with the asset pricing? 
Relevant answer
Answer
If your purpose is to calculate the market risk premium, you can simply use the definition to do so, i.e. Market Risk Premium = Return on Market Portfolio -Return on Risk Free Asset. In the US, S&P 500 is considered as Market Portoflio an dT-Bills as Risk Free.
However, if you believe that the beta and return on Risk Free Asset are more stable  for forecasting, then you may estimate Beta first using CAPM, then use the following formula: Market Risk Premium =Risk Premium on Selected Asset/Beta provide you have good forcast of this selected asset's return.
Question
3 answers
I'm currently researching for my Masters Thesis and looking into the associated health benefits of having a 'third place' that one regularly visits. And on the flip side the health issues with people not having access to a 'third place'.
Any direction on previous research is welcome!
Relevant answer
Answer
In many countries there are studies about the use of time. If you identify the time spent in first (home) and second place (workplace)  you can verify the time available for the 3rd place. After this is easy to understand how this time is used and make the link with individual or collective health.
Question
1 answer
Hi. I am using Simulink and I am trying to connect the solar cell block made up of 36 pv cells to current measurement block and voltage measurement block but I am unable to do so. Also I was seeing in some papers that someone connected the same to isensor and vsensor but I also couldn't find these blocks in simElectronics and simpowersystems etc. Does anyone know about this issue?
Thanks in advance.
Regards
Relevant answer
Answer
Question
4 answers
voltage unbalance in grid is important in grid connected converter.
How much is acceptable? 
Relevant answer
Answer
Dear salehi,
I hope the book titled "GRID CONVERTERS FOR
PHOTOVOLTAIC AND
WIND POWER SYSTEMS" by IEEE press would be useful to know about needful information.
Question
3 answers
Hi everyone,
I have designed a 1:4 power divider, and my job is to connect it to 2*2 planar patch antenna with coaxial lines.
I am unable to match the stripline to the coaxial line. Please provide me necessary information to overcome this problem.
Thank you. 
Relevant answer
Answer
Dear Pudu, you need a coaxial to stripline adapter , similar to a waveguide to coaxial adapter which you must have used to do any measurement with VNA. alternatively i can say that you have to match TEM fields of coaxial line to that of quasi TEM fields of stripline.
Question
2 answers
Hi I'm trying to do a simple script that measures current vs time for a fixed voltage using a Keithley 2400. Does anyone have a simple script they could share on how to do this? So far I am able to connect to the Keithley and set the voltage, but am having difficulties in recording measurements.
cheers, Rob
Relevant answer
Answer
Should be straightforward:
Goto Keithley website and download datasheet for the device, which will have all the commands
Have a look at this and the following chapters. Make sure your cabling, baud rate etc. is set up correctly.
Simple script:
Question
14 answers
A capacitor C1 = 1F is charged to 10 V and at t=0 it is connected across
another uncharged capacitor C2 = 2F. What is the total energy in the two
capacitors before and after they are connected in parallel. Give the reason
for any difference between the two values.
before connecting, I got energy across c1 = 50 and across C2 =  0, so total energy 50.
After connecting in parallel i got energy across c1  =50/9 and across C2= 100/9 , so total energy = 150/9.
am not getting what is the reason behind this, total energy in case 2 is less than case 1. please help me.........??
Relevant answer
Answer
Hello.
If you are considering a connection between the two capacitors with a finite value of resistance, the energy missing in the final balance is dissipated by the the resistance of the connection. You can do this by simply adding a resistor R in place of the closed switch and calculate its energy during the charge transfer.
If you are considering a connection with zero resistance it means that charges will accelerate during their transfer between the capacitors, the missing energy goes in this acceleration and it is stored as kinetic energy of the charges.
You can read the interesting paper at the link I attach for more details.
Best regards,
Giacomo
Question
11 answers
How we can reduce stray voltages in connecting wires while generating electricity through piezo- material?
Relevant answer
Answer
Keep the piezo wires as short as possible, and twist them together as a twisted pair.
In general, high impedance wires are going to be susceptible to picking up this kind of energy. Think of the wire pair as a loop antenna that is picking up whatever energy goes through the loop. The smaller you can make the loop, the less energy you will pick up, thus, short wire pairs and twisted pair!
Also try routing the twisted pair wires near a ground plane which will reduce the energy in the stray fields as well.
Question
3 answers
I connecter 3/3v to pin1 ground to pin 10 and sensor input to pin 20. But the XBee isnt powering up. I cant identify any problem. Please explain
Relevant answer
Answer
Please sir
best regards
Question
5 answers
Methods to avoid voltage reversal in MFCs stack.
I'm interested in control tools that automatically could detect a MFC module failure and fix it.
Relevant answer
Answer
Good Morning. Please find attach the link. Regards Ariadne Tsambani
Question
2 answers
Suppose you have multiple distributed sensor nodes which write to some kind of aggregation server, e.g. in the cloud. Maybe these nodes have a poor mobile connection and need to preprocess data before sending it most efficiently via the mobile connection. What are common techniques for preprocessing this data (lossless compression/ compression with losses etc.?
Relevant answer
Answer
This actually depends on the processing capabilities of the sensor nodes. A quite powerful sensor node might carry out signal processing procedures like fourier transform, wavelet transform, or even classification tasks.
Less powerful nodes likely preprocess the data in a quite simple way. Appropriate procedures are thresholding the data or averaging it.
Everything in between may also be possible - depending on the processing power, as I already said.
Can you provide some more details on the sensor node besides of the data connection constraint?
Question
14 answers
I have a problem with a spectrofluorometer LS55 PerkinElmer. 
The SCAN FL WINLAB application program does not run. And an error message is displayed: DDE Setup: Client failed to connect to server Lamp September. FL = On.
Relevant answer
Answer
Your problem is likely related to the broken xenon lamp. Check, the lamp is shining? To check, run the FL WINLAB -aplication-status-source then turn on/off lamp (press 1/0 button near lamp picture, and you must hear sound of working lamp). If source work correctly, try to reinstall FL Winlabг
Good luck
Question
6 answers
I had a high-pressure reactor (200 bar) that required regularly removing the catalyst bed section, and I noticed that the Swagelok connections for the bed tended to develop leaks quickly. The rest of the reactor also uses Swagelok connections, but these are fine as the connections are more or less permanent.
Does anyone have experience with flange connections and would be willing to advise on this connection type? Also, what, in your experience, is the consequence for heat transfer/loss?
Relevant answer
Answer
Swagelok fittings always fail if over tightened.  Swagelok's recommended procedure is to tighten them 1-1/4 turns past finger tight.  I have never had a leak when I tighten them 3/4 turns past finger tight.  That means that when I disassemble and reassemble, I can tighten them a little more each time until they no longer seal.  I typically tighten them by an extra flat (1/6 turn) each time I reassemble them.  That means I can usually get at least 6 reassembles without them leaking.  The only problem is you have to keep track of where the fitting was assembled last.  You can mark the fitting and one flat to do this.  To get even more use, use a feeler gage.  (Feeler gages are used by machinists.  They consist of a package of thin metal leaves of various thicknesses used to measure small gaps.)  Use the feeler gage to measure the distance between the nut and the body before you disassemble the fitting and then make the gap smaller by about 2 mils (50 microns) each time you remake the fitting.  For a 50 mil pitch (20 threads per inch) you can reassemble the fitting 25 times before it may start to leak.
Question
5 answers
In cases of power transformer how the primary coil of transformer knows that load is connected to secondary coil?
Relevant answer
Answer
When an ac voltage is connected across the primary terminals of a transformer, an alternating current will flow and self induce a voltage in the primary coil which is opposite and nearly equal to the applied voltage. The difference between these two voltages allows just enough current in the primary to magnetize its core. This is called the exciting, or magnetizing, current. The magnetic field caused by this exciting current cuts across the secondary coil and induces a voltage by mutual induction. If a load is connected across the secondary coil, the load current flowing through the secondary coil will produce a magnetic field which will tend to neutralize the magnetic field produced by the primary current. This will reduce the self induced (opposition) voltage in the primary coil and allow more primary current to flow. The primary current increases as the secondary load current increases, and decreases as the secondary load current decreases. When the secondary load is removed, the primary current is again reduced to the small exciting current sufficient only to magnetize the iron core of the transformer.
Question
6 answers
PLL for 3phase vsi connected to grid.
Relevant answer
Answer
Dear Colleagues,
Dear Shyam,
You can find complete design, simulation and implementation of grid connected inverter
including the PLL synchronization circuit with the grid frequency and phase in the paper
 Simulation and Implementation of Grid-connected Inverters, given in the Link: shootingcupoche.com/publication/233902842_Simulation_and_Implementation_of_Grid-connected_Inverters
If any question you can contact me or the first author Ahmed Abdalrahman
He is a member of the Researchgate.
Wish you success.
Question
2 answers
Electrical connection between the wire and electrode in MFC/MEC
Relevant answer
Answer
I do not know this MEC system, but depends on how high is the values to the first points of the real impedance. This can indicate how is the electrical resistance of your system/electrode. For resistive electrodes such glassy carbon the estimates values are around the 2000 ohm.centimeter square.  I hope that I can help a little.
Question
3 answers
I have a dataset of network connections (KYOTO +2006) that each connection has a label of attack or normal. (It doesn't determine which kind of attack).
According to a paper that I want to simulate, I need to choose RANDOMLY and FAIRLY a set of data which contain 1 percent of attack and 99 percent of normal but they did not discuss what does FAIRLY means.
I discriminated data in to attack and normal and randomly choose 1% from attack and 99% from normal but my result was too different from the base paper and I think the problem is in Data selection?
I have a question, Is data selection important in training an IDS (intrusion detection system) and what should I choose training data to be sure it covers all kind of attack and normal data.
Relevant answer
Answer
Yes, data selection is important in training the IDS since you are trying to identify attacks from your dataset.
So far as choosing of training data is concerned, I would suggest you to initially make protocols for either the clean dataset or the attacking one. Like if you have the list of attacking dataset you can compare all dataset with the existing attacking ones, if matches then block otherwise dataset is clean and so access allowed.
Question
7 answers
I am working on printed lpda antennas. In that top layer fed by center conductor of the cpw and two ground plane of the cpw connects the alternative element of the lpda elements and bottom one strip is connected through via. The via connects the center conductor and bottom strip. The strip have alternative elements. Why the short is needed? And bottom strip is connected to gnd or trace? How port should assign?
Relevant answer
Answer
Hi,
Please go through my paper attached here. This is the most easiest and practical way of feeding LPDA antenna specially printed one. Please let me know if you need any help.
Best,
Daniel
Question
2 answers
I want to know the work done on connectivity of regular and triangle free graphs.
Relevant answer
Answer
Dear Prashant,
Data Base of the AMS contains 22 records, see the attached file. Good luck!
Regards,
V.Voloshin
Question
8 answers
I am currently looking into circuit theory resistance modelling (http://goo.gl/fPOSVw) as an alternative to least-cost path approaches for modelling ecological connectivity throughout a major surface water network in Australia.
The Circuitscape (http://www.circuitscape.org/) software package seems to do everything I would like to do, but ideally I would prefer to conduct my analyses completely within the R environment. The "commuteDistance" function within the "gdistance" R package (http://cran.r-project.org/web/packages/gdistance/) comes close, but seems to only support resistance modelling between points/nodes, rather than two-dimensional patches/polygons as is possible in Circuitscape.
Is anyone aware of an R package which allows for circuit theory resistance distance modelling between patches, or an alternative approach I could use to achieve similar results?
Relevant answer
Answer
From my understanding it's pretty easy to call Circuitscape from R. All you need to do is create the .ini files and then call cs_run.exe, which is located in the installation directory. We do that in Python, and I know others (Bill Peterman, who is in the Circuitscape user group comes to mind) do it using R. Note that we will be releasing a completely overhauled version (4.0) in the next 2 weeks (there's a beta version on GitHub if you want to see it sooner) that runs about 2.5 times faster and solves grids that are 4-5x larger. Hope this helps.
Question
2 answers
Only few papers actually explain the mathematics of connectivity they've used.
Relevant answer
Functional and effective.
Question
8 answers
the reliability services has the same meaning with connection oriented services in network connection or not????
Relevant answer
Answer
Hi Sarah,
Please refer to the following links and file, which may lend support Majid's and Rivalino's comments and help answer your question. I wish I could be of more assistance.
Thank you for the interesting question :)
Respectfully,
Brady
Question
5 answers
Hello, I was wondering if someone has written or made some researches about this topic?
Thank you very much
Relevant answer
Answer
You might be interested in the attached article.
Question
8 answers
Is there any example of a connected metric space in which closure of an open ball B(a,r) need not be equal to the closed ball B[a,r].?
Relevant answer
Answer
Yes.  Let X be R^2 with the open square of side length two centred at the origin removed under the usual Euclidean metric.  So X=R^2\(-1,1)x(-1,1) with the usual Euclidean metric.  Now let a=(1,0) and r=2.  The closure of B(a,r) does not contain the point  (-1,0) but B[a,r] does.
Question
4 answers
Hi.
I've modeled 2D RC moment frame. Then I used diagonal braces in that frame (I've used equal DOF 1 2 for introducing hinge connection between brace and frame, braces are buckling restrained braces, I used truss element for yielding portion and elastic beam column for connecting portion).
the calculated natural period is equals for two models, and even when I use too big cross sectional area for braces the period does not change any way; Why?
Relevant answer
Answer
Hi Sahar
It's not really easy to find the error in your code this way. But based on what you described, if two natural periods are exactly the same, so it is possible that you have defined the coordination of nodes (or bracing members) wrong. In other words, OpenSees can not recognize the bracing members as a part of RC structure's domain, hence does not include their stiffness in stiffness matrix.
Question
11 answers
If a graph depicts connectivity, what does it tell us about the space it segments?
Relevant answer
Answer
Firstly, in graph theory there is the notion of planar graphs, that is graphs that can be embeddd in the plane without any crossings. If a graph is not planar, it has a genus, that describes its basic topological properties. It is known that such graphs of higher genus can be embedded in compact closed surfaces in 3 dimensions. That is dependign on their genus number. For example torus, brezel, triple torus, .... -> embedding graphs in surfaces. This is one topological feat of graphs at the level of abstraction comparable to connectivity.
Furthermore, in the 80s there was one famous question called the "Four color theorem" ->Wikipedia that asked about how to color countries in maps, such that non-neighbouring countries don't have the same color.
Structural questions on graphs also involve "Clique Partition", which is a computationally hard problem, but maybe can be adapted to work locally.
There are many more questions you can ask about a graph. Most of them are computationally hard, but for small instances or locally they can maybe provide nice insight. Maybe it would be possible to consider such questions locally and then extending topologically by using sheaf theory.
Question
2 answers
Hello, I have a Hitachi S3500N tungsten SEM and im interested in mapping  DC current distributions in my samples. My Hitachi affiliate offerd me an equipment that they make called the "NanoPico". it is a current amplifier that has an output that can be connected to the SEM to obtain an image. My question is if any one has used it could you provied your insight or perhaps examples. or if any one knows of another option that would be helpful too. 
Thank you
Victor I Hernandez
Relevant answer
Answer
Hello to all the followers and readers, it appears that many people are interested however no one has answered. perhaps if we each send this question to any Hitachi user maybe we could come up with an answer...any help is much appreciated.
Question
5 answers
Hello
I am using Abaqus for my numerical models. I want to create a user element with more nodes than the usual elements and in different place. I understand that following this i have to provide in the input file. the coordinates of the nodes and the connectivity of the elements. 
I wonder if there is a way to program an CUSTOM ELEMENT SHAPE in order to create the abaqus the connectivity instead.
Thank you
Relevant answer
Answer
Hi Christoforos S. Rekatsinas
Although you can use from any custom element shape, but the selected element shape should be satisfied some criterias. For use from a custom element shape, please follow these steps :
1- Specify the longest length and shortest length of your custom element shape (respectively a & b).
2- Calculate c= a/b from part 1.
3- You can determine the mesh type that you want to use in the calculation. If you don't know how you should do this, neglect this step but if you do it, it is better for next steps.
4- Chech c according to HYPERMESH criteria. If c doesn't place in this criteria, you can change c by changing a & b. If c be in the HYPERMESH criteria range, HYPERMESH suggests the best number of nodes for your custom element shape and you can put these nodes  in desdired places.
5- Now you can specify all cordinates of the maked nodes in the element shape and put them in a file.
Note that:
1- In part 1 you should not specify the number of desired nodes. HYPERMESH implements this operation.
2- After determination of the best number of fnodes by HYPERMESH, you must put nodes in the places in a manner until parameters a & b don't be changed.
3- You can use from different spider configurations of mesh types. This may led to changing in the number of nodes according to HYPERMESH criteria.
At final, if you have not HYPERMESH criteria, I can send it to you.
Question
3 answers
What formula to used? Should the MMF fiber be cleaved less than reimging distance to have max coupling?
Relevant answer
Answer
Good day,
I am trying to understand exactly what you are trying to do here. From my understanding, you are trying to couple light from a single-mode fiber to a multimode fiber through some sort of optical system (for instance, a lens)? If that is the case, another important question to ask is: do you need to operate only in the fundamental mode of your MMF or you don't mind have a mixture of modes? 
Another way to ask this question is: do you need the system to work in both directions? i.e. from SMF to MMF and back again?
Generally, coupling efficiency in multimode regime will be driven by what is called the brightness ratio, which is analogous to the beam parameter product in laser science. For a multimode fiber, this quantity is roughly given by the product of numerical aperture and core size:
BMM=RcoreNAcore
with Rcore being the core radius and NAcore is the core numerical aperture. For a step-index single mode fiber, this quantity can be approximated as:
BSMF=U/kwith k0 being the wavenumber in vacuum and U being the solution of the waveguide eigenvalue equation (see Optical Waveguide Theory, Snyder and Love, 1983).  From there, the maximum achievable coupling in MM regime can be derived from the ratio Ca-b=(Bb/Ba)with "a" being the input fiber and "b" the output fiber. Usually, going from SMF to MMF using the definitions here will yield CSMF-MMF>1, which means that all the power will be coupled but there will be a loss in brightness so that the action will be irreversible as the coupling efficiency on the way back would be CMMF-SMF=1/CSMF-MMF<1. So, basically, for best coupling you need to design your optical system so that the beam parameter product "B" on each side of it fits within the range of the corresponding fiber.
However, for single-mode operation on both sides, one needs C=1 and thus free-space systems are generally not the best options. Mode-conversion technology is often a much better approach to such problems (see for example the attached link).
Hope that helps and good luck!
Question
8 answers
any possible technique or algorithm.
Relevant answer
Answer
Your question is not very clear: what do you mean with different WiFi zone connective regions? 
802.11s defines message exchanges on layer 2, and IP addresses are layer 3 addressing. So the question sounds ambiguous.
But, you should not have the same IP address within the same network. If, however, with "different WiFi zone connective regions" you mean that there are actually two disconnected networks, you may use the same IP address without expecting problems. 
Hope this helps you move forward.
Question
2 answers
Given a set of points in three-dimensional space, which are the most common ways of measuring if they are co-localized or not? E.g., a graph-based approach would be to build a graph using points as vertices, connecting them by edges if they are below a distance threshold and them applying a connected components algorithms to see if the result is a single component. Continuous measures instead of discrete ones are welcome as well.
Relevant answer
Answer
Two issues seem to intersect in your question. (1) are the points all in a similar local area; (2) is the graph constructed according to some proximity rule connected. I think if the answer to (2) is yes, the points are clustered. But the "proximity rule" that you use has to be carefully chosen ... if it is too weak, (large distance threshold) of course everything will be connected.
How about this -- if the data set is not HUGE develop a matrix of all inter-point distances.
(D(a,b) = some metric measure of distance between observation a and b.)
Then, apply a hierarchical agglomerative clustering scheme to this -- join the two closest points, replace that with their mean, join the next two etc. As you reach the end of the run, ask yourself are you needing to join points that are really outliers to the existing cluster; if yes, you probably have disconnected pieces. The resulting "dendrogram" will also allow you to slice across horizontally to see what observations are in the clusters.
You could also try a minimum weight spanning tree (can be done with a greedy algorithm) and see if you like the diameter of the resultant network? Just some ideas.
What is the meaning of nonreal eigenvalues of Schrödinger equations if the weight is indefinite?
Question
15 answers
Solving Schrödinger equation with indefinite weight connected with Richardson problem 1918 when the potential is indefinite sign. What is the meaning of nonreal eigenvalues if the potential is indefinite from physical point of view.
Relevant answer
Answer
hello, non real eigen values, means that the solution of the LNS ( non linear Schrodinger equation)  is unstable ,  with an  exponential growth rate  .  ( solution has the form:     solution(x,t) = a  exponential ( i  * eigenvalue * (kx - wt) ) if (Imaginary Part) of eigenvalue  is non zero , then  solution grows with time and space.   ( or decay : depend of the sign of the Imaginary part ) best regards4 hubert
Question
15 answers
A few months ago, under the same conditions, it remained stable over 100 samples. I have tested all connections, I've replaced the column, and all parameters remained stable.
Relevant answer
Answer
Hey Angel,
I'm not sure if you mean (a) unreproducible retention times compared to 6 months ago or (b) unreproducible retention times from run to run currently.
Without looking at your data (HOW the retention times are shifting), we will only be able to make a crude guess at the solution to your problem, so here are the most likely solutions assuming you are using fairly routine solvent systems, parameters and samples.
If it is the former, (a):
1. check your mobile phase composition - it is not likely the additives (formic acid, acetic acid etc.) but if you are mixing multiple organic solvents for your solvent B, you must be very precise when preparing these. I recommend using a burette to distribute appropriate solvent volumes (keeping in mind proper burette rinsing techniques)
2. Make sure you are using the EXACT same column, and that this column has not degraded - manufacturers will usually have approximate guidelines for number of injections/ run time a column can reliably be used. Even columns with the same stationary phase material (C18) can vary from batch to batch from the same manufacturer but even more between manufacturers
If it is the latter, (b):
1. Calculate 10 column volumes for the column you are using. This volume of starting mobile phase composition (ex. 70% mobile phase A, 30% mobile phase B, if that is what your run starts with) should pass through the column after your column wash step and before the start of each sample injection.
Less likely causes for (a) or (b): 
Errors with pump mixing - pump pistons (not likely) or seals could need to be replaced. The A and B pump seals needed to be replaced every year like clockwork on the Acquity UPLC instruments I've worked with - even if they do pass the vendor tests. (The vendor tests only measure pressure differences over very short intervals of time, so if you have a slow leak, the vendor tests will not pick this up. However, you will be able to see this by observing the pressure trace over a longer period of time (ex. 20 minutes).
Your samples could be changing over time (this is very unlikely but some situations in which this would become more likely: you have reactive substances in your samples/sample solvent and/or you are running samples over multiple days and/or the solvent your samples are stored in reacts with your samples and/or your samples are unstable at the conditions you use to store them in the autosampler). You can minimize this by storing at lower temperatures and making sure you understand your solvents and samples.
Question
3 answers
The voltage sensor block is not getting connected across capacitor, how can I fix that?
Relevant answer
Answer
Dear Jhansi,
The question is a bit vague. What I understand is that you need to measure a voltage via a capacitor. It may for instance be that you want to measure the high voltage of an electrostatic charging process, or that you want to measure millivolt AC pulses. So, to help you solve the question more information is needed.
What do you mean with the term voltage sensor block (type, manufacturer)?
What is the voltage range that you need to measure?
Is it DC or AC voltage you want to measure?
To which system must the signal be conditioned?
What is the accuracy etc. needed?
Kind regards, Fokko Wieringa
How do I demonstrate a electrochemical reaction is connected with a chemical reaction?
Question
15 answers
Namely, two electrochemical readtions are expressed as follows: A+e=B;  C+e=D What electrochemical experiments should I take to demostrate these two equations are connected as follows: A+e=B; B+C=D+A Is there any reference relevent to this topic?
Relevant answer
I do agree with I. O Gyan, cyclic voltammetry is the best technique, however it would be better if you could combine CV with another characterization technique for instance IR, UV, etc depending on the species involved. There is an ancient but very good paper regarding this subject: RICHARD S. NICHOLSON and IRVING SHAIN, Theory of Stationary Electrode Polarography, Single Scan and Cyclic Methods Applied to Reversible, Irreversible, and Kinetic Systems, ANALYTICAL CHEMISTRY, VOL. 36, NO. 4, APRIL 1964. Recentely I published a syudy n the same subject: M. L. Afonso, A. I. S. Neves, M. Almeida, “Dimerisation of Fe bisdithiolene complexes: An electrochemical study”, Inorganica Chimica Acta Vol. 426, 160-164 (2015).
Question
3 answers
How can I create artificial neutral?
Will the dc supply work if load is connected from+ to earth .the - terminal is also connected to earth?
Relevant answer
Answer
Earth and ground are the same. it is safety path provided to carry away the short circuited or faulty current away from the utility.
whereas neutral is the return path provided to complete circuit.
No current flows in earth or ground wire under normal conditions, it has current only when device has faulty current.
Question
9 answers
I just need it for idea sharing and research purpose.
Relevant answer
Answer
Dear Beneberu,
It is very difficult finding a binary logic between the 3 variables taken two by two: efficiency/competitivness; efficiency /market performance; competitivness/market performance. It shoud be taken into account the direction of the effects and their feedback.
To maximize efficiency, tha farm has to minimize unit costs, but it has constraints (technologic level; land and capital resources; manpower capabilities etc.)
To maximize competitiveness is a challenge. The farm in the great commodity markets is a price-taker and not a price-maker.
In the niche markets farms may operate in conditions of monopolistic competition, but the size of the market is limited. There are contextually the problems of maintaining the quality and that of product diversification.
Maximizing the market performance is a black-box the scientists have not yet been able to highlighten.
To your question even the managers of the largest multinational companies have turned their attention as well as those of the single firms or farms. But indipendently from the size of the company the problem remain insoluble at the present state of economic science art.
Merry Christmas
Question
2 answers
I am wondering if the connectivity between CNS and PNS is vital for the release of acetylcholine at NMJ. To what extent would the release of acetylcholine at NMJ be affected if spinal cord is injured partially or completely.
Relevant answer
Answer
Dear Dr. Abdulrazaq, please elaborate on the sentence "the extent of acetylcholine release depends more on the level at which the spinal cord is transected" what does it mean? 
Question
4 answers
Somehow, if you have experiences, that will be a great help. But if you have some indication for help, that is also very nice. Feel grateful.
Relevant answer
Answer
Thanks a lot.  I will try to connect the humbug to PC, and find a BNC to USB cable.  
Question
4 answers
Can any one help me to find the, advantages and disadvantages of bidirectional Switch(series connection of two unidirectional switch) over Unidirectional switch
Relevant answer
Answer
I just add one comment: bilateral switches, which block but also conduct current with both polarities are very common in MOSFET digital (e.g. to make very space-efficient XOR gates or MUXes in VLSI chips) or switched capacitor (SC) circuits (those mentioned bilateral switches are the "switches" in SC technology), for instance. This switch is called the "CMOS bilateral switch" or the "CMOS transmission gate". 
A popular digital CMOS IC with four of them inside is the 4066; see for instance http://www.ti.com/lit/ds/symlink/cd74hct4066-q1.pdf
Question
4 answers
I know that support vector machine runs well in Matlab. But I have to know how well it works in java and which is easier to connect with NS2.
Relevant answer
Answer
MATLAB is the easiest way to implement SVM. Java is also a good idea but the only problem is that coding needs to be done and the number of lines of code in Java is more than MATLAB.
What are the mechanisms for the growth of natural gas networks in urban areas?
Question
36 answers
What are the mechanisms for companies operating natural gas distribution you to realize natural gas connections for residential?
Relevant answer
Answer
Dear Iliana, Far as I know there is no incentive for the use of piped gas in Brazil, because the use of canisters is still dominant in the poorest class. Vanessa
Question
4 answers
We use 3 electrodes. Is there any sequence to connect WE, RE, CE for RDE? Also, the positions of those electrodes in the electrolyte solution? I usually place left side is CE and right side RE and then between them WE were positioned at a little upper level.
Relevant answer
Answer
I think your placements are OK. In cases of a bad conducting electrolyte you must be careful not to place the reference electrode between the WE and the CE because there might be an Ohmic drop effect and the RE measured the wrong potential. Many researcher also use a Luggin-caplillary closer to the WE surface but out of the main current pass flowing between the WE and CE.
Question
2 answers
I want to know which one of modules in Apache web server connected together.
Relevant answer
Answer
Thank you for the reply.
Following website is good to understand what's happening between modules:
Question
1 answer
It is connected with the synthesis of Al species from NaOH and AlCl3 solutions (OH/Al3+ ratio equals 2.4).
Relevant answer
Answer
Dear Daniel, 
The reversed Keggin type {Al13} in principle dissolves quite well in water. 
As a polycation it can be crystallized together with Cl- anions. Check this reference for more details:
European Journal of Inorganic Chemistry (1998), p795-p797
If your aim is to isolate it, then follow the experimental conditions from the previous reference. You can also try to play with the Cl- concentration and the solution pH. 
Similar strategy works well with polyoxometalates. 
I hope this helps. 
Best,
Aleksandar
Question
15 answers
I am looking for a homomorphism in a topological group that which uses by a single and fixed point. I mean for a fixed element of G, how we can construct a group homomorphism. For a fixed g, I tried the definition x \to gx, by this is not a group homomorphism. How we can do it?
We can add some hypothesis to G, like being locally compact or connected.
Relevant answer
Answer
I believe what you are asking is not possible.  Although strictly speaking the following is one solution:  Parametrize the abelian group S^1 by t\in[0,1]. For g = 1/n \in S^1, we have the homomorphism  t \to nt mod 1.  This is a homomorphism of S^1, and depends on g = 1/n.  !  But I feel that is not the kind of answer you are looking for.
Question
10 answers
strategic actions affect firm's financial performance
Relevant answer
Answer
Some articles you may benefits from;
Kaplan, Robert S., and David P. Norton. "Using the balanced scorecard as a strategic management system." Harvard business review 74.1 (1996): 75-85.
Robert, S., and P. David. "Using the balanced scorecard as a strategic management system." (2011).
If you are using a casestudy, this article may help;
Yüksel, İhsan, and Metin Dağdeviren. "Using the fuzzy analytic network process (ANP) for Balanced Scorecard (BSC): A case study for a manufacturing firm." Expert Systems with Applications 37.2 (2010): 1270-1278.
Question
2 answers
Please share any references that address this topic.
Relevant answer
Answer
Hi Katelyn,
The resolution of DTI is generally not high enough to achieve monosynaptic fiber tracking in vivo. There is a paper of Bai et al with microscopic resolution (www.pnas.org/cgi/doi/10.1073/pnas.1519890113), which might be of interest for your question... Newer techniques using Kurtosis imaging might give you some more details when reconstructing fibers. But for all DTI based techniques one has to talk about "most probable fiber bundle tracks" due to the underlying physics, implying that there is only stochastic information about a synaptic connections. Where an axon ends is not answered.
For further reading I'd suggest some pre clinical studies of Harsan et al and some studies on fiber reconstructions. A newly developed technique, which is theoretically able to identify single neuron connections is shown here: See link or DOI: 10.1038/ncomms14162 .
I hope that helps. Please dont hesitate to ask, if you have further questions.