mysql – How to query differences between two tables with identical definitions?

I have two tables, A and B with identical columns. Table B can contain some rows where data are different from A. How can I write a query that shows rows that should be inserted into B, deleted from B, or updated in B to make the tables contain identical data?

blockchain – pBFT vs PoA what are the key differences

so i was watching a video on PoA and it kinda threw me off, those two (pBFT and PoA) are prett similar, arnt they?

@pBFT you get about 20 or less pre-chosen validators, their identity is mostly likly known to the network, and the secondary nodes could potentially gain primary node role

@PoA thers a fixed number of validators (authorities) that are pre-chosen and those validators produces new blocks – any new block could potentially become a validator, right? Of course just if they pass the authorization process dictated by the network.

Question is, what are the actual differences between the two?

Hope someone can help:)

best regards

Differences Between Designing Native Ios Apps And Native Android Apps

A common request from people. is to build an app that has the same iOS and Android design features. A reasonable ask, by all means. The problem is that iOS and Android design is specific to their individual platforms. As in, each platform has their own design styles, idioms and ideologies. Therefore, users expect apps to look and act in a certain manner according to their platform of choice. And it can be really difficult to move away from this! Read more about differences between Designing Native iOS Apps and Native Android Apps

customization – Possible to create a “variant” page template that only contains differences and is therefore resilient to updates of original (ie page.php)?

I would like to create a page template in my child theme called “Services” – this template is identical to page.php in design (I just want to add some JSON LD markup to these pages).

However I’m concerned that in the event of a theme update, that my template will become “orphaned”… that is, page.php will get changed fundamentally on the parent theme, but my services-page.php file will not reflect those changes.

As such:

Is there a smarter way of creating a template so that I don’t need to use a “snapshot” of the entire page.php file, but could (eg) only include the changed (schema) code, and then call the original page.php for the rest of it – so that it always matches the parent theme’s page.php template otherwise?

I hope that all makes sense – I am open to another solution but so far a template seems to be the easiest way to insert this code on these services pages.


Problem with initial conditions for numerically solving the Sine-Gordon equation using finite differences method (in MatLab).

We are trying to solve numerically a kink solution in matlab using the sine-gordon equation, therefore followed the steps according to the paper (1) listed below. The sine gordon equation is a non-linear pde and the numerical solution was clearly explained in the paper (1). However, the problem is that if we use the initial conditions f(x) and g(x) (page 6 of the paper), the solution will have a disturbance and is not as clean as figure 5.4a (p. 6) from the paper it self. To solve this we ‘doubled’ the size of the soliton by replacing ‘x’ in the initial conditions for ‘x/2’. Therefore my question: What is the explanition that dividing x by 2 instead of taking just x justifies? Perhaps we made a mistake in the numerical model?

Thanks for your time.


  1. The paper used:
  2. There are a few references from source 1 to chapter 4:

Matlab code

The changes of the inital conditions are cleary commented in the matlab code.

clear all; clc; close all;
%% Define variables
L = 40; %Choosing a bigger L can make it look nicer, also change it in the function at the bottom of the code
delta_x = 0.05;
delta_t = 0.01;
c = 0.2;
t_end = 90;
T = t_end/delta_t;
M = L/delta_x;
N = M+1;
x = linspace(-L,L,M+1);
t = linspace(0,t_end,T+1);
%% Calculate first time row

u_0 = transpose(f(x));
gamma_1 = transpose(g(x));
beta_1 = sin(u_0);
alpha = delta_t/delta_x;

a = 1-alpha^2;
b = alpha^2/2;
c = b;
A = diag(a*ones(1,N)) + diag(b*ones(N-1,1),1) + diag(c*ones(1,N-1),-1);
A(1,2) = A(1,2) + b;
A(N,M) = A(N,M) + b;
B = 2*A;

%% Calculate second time row
u_1 = delta_t*gamma_1 + A*u_0 - (delta_t^2/2)*beta_1;
u = zeros(N,T);
u(:,1) = u_0;
u(:,2) = u_1;

%% Calculate the full matrix
beta = zeros(N,T);
beta(:,1) = beta_1;

for j = 2:(T)
    beta(:,j) = sin(u(:,j));
    u(:,j+1) = -u(:,j-1) + B*u(:,j) - (delta_t^2)*beta(:,j);


for n = 1:T-1
    for l = 1:N-1
        e(l,n) = (1/2*((u(l,n+1)-u(l,n))/delta_t)^2+1/2*((u(l+1,n+1)-u(l,n+1))/delta_x)*((u(l+1,n)-u(l,n))/delta_x)+(1-cos(u(l,n+1)+1-cos(u(l,n))))/2);
    E(n) = delta_x*sum(e(:,n));

%% Define the functions 
% Single soliton
function f = f(x)
c = 0.2; %This can be varied to create a nicer picture, also change it in the 'g'function
L = 20; %This can be varied to create a nicer picture, also change it in the 'g'function
f = 4*atan(exp((x/2)/sqrt(1-c^2))); % the '+L/2' can also be changed to have a different starting point for the soliton, don't forget to also change it in the 'g'function
function g = g(x)
c = 0.2;
L = 20;
g = -2*c/sqrt(1-c^2)*sech((x/2)/sqrt(1-c^2));

What are the differences between game engine, game framework, game library, API and SFML?

There are many concepts that I do not get the differences between them. Can somebody explain them in simple words?

authentication – Key differences between X509 TLS Client certificate and server certificate

Is there any difference in X509 TLS Client cert and Server cert?

I had been implementing the certificate based mutual authentication and hence trying to get/use certificate for clients which are IoT Devices. while we are pretty much clear on server certificate, I was wondering if client certificate that individual IoT devices will load and present to server for their authentication are same / similar to what is used for server!
will client certs also to be acquired from a CA and then they will be validated by server via root CA cert in same way as server cert is validated against the root CA?

would appreciate some insight!

co.combinatorics – High degree differences in bipartite graphs

Consider a finite, simple and undirected graph $G=(V,E)$ with $V={v_1,dots, v_n}$. Let us define the quantity:

$$mathcal{I}_k(G) := sum_{1le i,j le n} mathbb{1}{Big{|mathrm{deg}(v_i)-mathrm{deg}(v_j)|ge k}Big},$$
i.e. the number of all those pairs $(v_i,v_j)$ with degree difference greater or equal to $k$.

In the answer to a previous question,

Pairs of vertices with high degree difference

I was able to prove, that:

For $k>frac{n}{2}$, we have

begin{equation} mathcal{I}_k(G) le 2k(n-k). end{equation}

Now, my current question is: does it also hold for bipartite graphs? More precisely, consider a bipartite graph with vertices $${v_1,v_2,dots, v_n} cup {w_1,w_2,dots, w_n}.$$
Is it also true that (still assuming $k>n/2$)
$$sum_{1le i,j le n} mathbb{1}{Big{|mathrm{deg}(v_i)-mathrm{deg}(w_j)|ge k}Big} le 2k(n-k)? $$
If we would think about those two problems in terms of adjacency matrices, then the first (solved) problem is about symmetric matrices and the current one is about general matrices without the symmetry condition. Computer verification for $nle 10$ confirms this conjecture. Unfortunately, the proof suggested in the previous case does not seem to work in this case (it is not clear how to generalize it).

What I tried doing was incorporating the Gale–Ryser and Ford-Fulkerson conditions (equivalent to the bipartite realization of double integer sequences as degree sequences). Unfortunately, I did not succeed.

As previously: I would be very grateful for any comment or insight. Maybe looking on this question, You will think of some other related problem or theorem that might be helpful. Maybe You are able to say what a general strategy might be appropriate to handle this problem. It may turn out that for some reason this problem is trivial but I have overlooked it. I will appreciate any help or advice.

Calculated column for differences between two column dates with blank check if blank use another column for difference – Sharepoint list

I am trying to create a calculated column which shows the number of days’ difference between two columns which have dates in them. I understand that I can get this with the following formula:

=DATEDIF((Date 1),(Date 2),”D”)
which indeed works, as long as there is a date in both columns.

I am looking for formula – if one of the date is blank, then it should use another column date to find difference

My Calculated column would be names as (daysvacant)
Days between (PositionFilleddate) – (resigneddate)

if (Positionfilleddate) is blank, then i want (Today)-(resigneddate)

Thanks in Advance

openssl – Application to detect SSL certificate fingerprint differences

My project is to find out how to detect HTTPS interception/mitm and create some sort of application using detection techniques. One of the ways I was thinking of is a active desktop application to listen in on the connections between client and server to check the authenticity of SSL certificates using the certificate fingerprint. Is it possible to create a desktop application in python (or any other language) to detect HTTPS interception using the sites SSL certificate fingerprinting?

Taking a look at this page, it seems quite possible to do so.

I understand that browsers are likely to have built-in technologies to do this but this is something that is part of my research and development project.