Force NDSolve to include three BC constraints to a second order ODE because generic NDSolve choses wrong intial slope

The following is an ODE that represents a numerical solution for the radial part of the heat equation corrected to first order for a spatially varying thermal conductivity in spherical coordinates. This computes the temperature distribution near the tip of a self-cooled electrode / ablation catheter. Since the heat equation is second order, NDSolve requires two BCs, but faults when three are specified. The problem requires the specification of temperatures at an initial and final spatial point {r0,large} respectively. In order to specify a power input, the temperature slope must be specified at the initial position (tt'[r0]). There is an extreme temperature point (max/min) at an intermediate point between initial and final temperature locations.(See graphic below.) The generic NDSolve chooses the wrong sign for the initial temperature slope because the curve length between initial temperature, (tt[r0]) and final temperature, (tt[large]) is shorter when (tt'[r0]<0) versus curve length when (tt'[r0]>0). The question is how do I specify the value of (tt'[r0] = pwr/(thermalConductivity * r0)) ? NOTE: As I have stated before, I am only a dumb engineer who only infrequently uses Mathematica when I need a solution that could have been solved by a Mathematician and is free of the errors and inconsistencies of Matlab. I would appreciate it if one of the “monitors” would transfer the code and graphic to traditional “people readable” format here. Thanks!!

<< VectorAnalysis` SetCoordinates[Spherical[r, theta , phi]] de = \!\(TraditionalForm\`Div[\((1 + \((dkc/kc0)\)*tt[r])\)*   Grad[tt[r]]] - \((pwr/\((\((kc0 - dkc*tt[r])\)*r)\)\ *\ \((r0^3/     r^5)\)\ )\)\);   ss = Simplify[de]; kc0z = 1.0; dkcz = 0.01; r0z = 0.1; largez = 20.0; pwrz = 40.0; tbodz = 37.0; tzeroz = 25.0;  ppp = NDSolve[{{ss == 0, tt[r0] == tzero, tt[large] == tbod}},  tt[r], {r, r0, large}] /. {kc0 -> kc0z, dkc -> dkcz, r0 -> r0z,  large -> largez, pwr -> pwrz, tbod -> tbodz, tzero -> tzeroz } rmax = 0.5; Plot[Evaluate[tt[r] /. ppp], {r, r0z, rmax}, Frame -> True,  GridLines -> Automatic, PlotRange -> {{r0z, rmax}, {0, 50}}] 

Temprature plot from r0 to "large"

(Wrong answer (100%) (URI) (Problema – 2857 – Fluxo nos Vagões) ( Link – https://www.urionlinejudge.com.br/judge/pt/problems/view/2857) [pendente]

    #include <iostream>     #include <algorithm>     using namespace std;      int N;     int *vet;   void atualiza(int, int); int soma(int x); void casoespecial(int , int , int , int, int );   int main() { int  n,m, x,y,a,b,c,d,local,aux,tam=4; int v[tam];   cin>>n>>m;  vet = new int[n];  N=n;     for(int i=0;i<m;i++) {       cin>>n;      if(n==1)     {         cin>>x>>y;          local=x;          atualiza(local,y);      }     else if(n==2)     {         cin>>a>>b>>c>>d;            if(a==b and c==d)         {               if(c==b)             {                    cout<<soma(b)-soma(a-1)<<endl;             }             else             {                 cout<<(soma(b)-soma(a-1))+(soma(d)-soma(c-1))<<endl;              }         }         else         {                  if(c<a and b>=d)             {                  if(d>=a)                 cout<<soma(b)-soma(c-1)<<endl;                 else                 casoespecial(a,  b,  c, d, tam);              }             else if(c<a and d>b)             {                 cout<<soma(d)-soma(c-1)<<endl;             }             else if(a<c and b>d)             {                 cout<<soma(b)-soma(a-1)<<endl;              }             else if(a<=c and d>=b)             {                  if(b>=c)                 cout<<soma(d)-soma(a-1)<<endl;                 else                 casoespecial(a,  b,  c, d, tam);              }           }                 }  }   return 0; 

} void atualiza(int local, int v){

while(local <= N){        vet[local] += v;     local += (local & -local);    } 

} int soma(int local){

int s = 0;  while(local > 0){        s += vet[local];      local -= (local & -local);   }  return s; 

} void casoespecial(int a, int b, int c, int d,int tam) { int v[4];

v[0]=a; v[1]=b; v[2]=c; v[3]=d;  sort(v,v+tam+1);  a=v[0]; b=v[1]; c=v[2]; d=v[3];   cout<<(soma(b)-soma(a-1))+(soma(d)-soma(c-1))<<endl; 

}

Agile software development teams don’t need project managers, am I wrong?

I’ve been working as a software developer for coming up on 12 years and during this time I have worked as part of a number of successful agile software development teams. Interestingly on most of these teams there was no one fulfilling the role of project manager as the teams in question adhered to the values & principles set out in the Agile Manifesto.

Therefore I have come to realise the following;

If a software development team adheres to the values & principles set out in the Agile Manifesto they do not need someone fulfilling the role of project manager.

My reasons for thinking this are as follows :

  • Agile software development teams are cross-functional by nature, which means they consist of software developers and business clients. This adds a high level of transparency to the teams activity, thus negating the role of project manager in relation to tracking and reporting on the team progress.
  • Agile software development teams are self-organising, which means the entire team decides on deliverables and associated timelines. In my opinion this removes the need for a project manager in relation to scheduling a teams activity.
  • Agile software development teams advocate adaptive planning, which means software developers and business clients can react to shifting requirements. This removes the need for a project manager in relation to scoping estimates for features.
  • Agile software development teams encourage rapid and flexible response to change. Therefore having a project manager on an agile software development team would be counter-intuitive as they would add unnecessary process to a lightweight process.

I would be interested to hear the opinion of other software developers on this topic. Do we need project managers on agile software development teams?

SharePoint list items pulling from wrong list

We have a monthly newsletter where we link to stories that are posted from different lists. Every time there are two links with the same item id number, but different list numbers anonymous users can only pull the first one that is accessed (works fine when signed in). Any ideas why SharePoint seems to be caching the item ids, but not the list id numbers?

What to do when using an internet time source changes your computer to the wrong time?

This is a strange one I haven’t seen before. I thought about posting this on ServerFault because it is a server, but I figure it is more of a Windows issue than a server issue.

I have: Server 2008 running on VMWare – it is not a domain controller, and it has also been removed from the domain.

Whenever I go in to my time/date settings and tell the computer to “Update Now” from an internet time server (time.windows.com) the time on the server jumps ahead 10 minutes. I’ve also tried us.pool.ntp.org.

All other places I have checked the time on the server is 10 minutes ahead after that.

I have tried the VMWare option to synchronize host/guest time both on and off. If I turn it on, VMWare synchronizes the clock back to the correct time, then it jumps ahead 10 minutes as soon it syncs with time.windows.com.

I’ve also changed the time manually, and have observed the same behavior.

I’ve confirmed the timezone is set correctly.

So, does anyone know why the windows time service is setting the server 10 minutes ahead?

What to do when using an internet time source changes your computer to the wrong time?

This is a strange one I haven’t seen before. I thought about posting this on ServerFault because it is a server, but I figure it is more of a Windows issue than a server issue.

I have: Server 2008 running on VMWare – it is not a domain controller, and it has also been removed from the domain.

Whenever I go in to my time/date settings and tell the computer to “Update Now” from an internet time server (time.windows.com) the time on the server jumps ahead 10 minutes. I’ve also tried us.pool.ntp.org.

All other places I have checked the time on the server is 10 minutes ahead after that.

I have tried the VMWare option to synchronize host/guest time both on and off. If I turn it on, VMWare synchronizes the clock back to the correct time, then it jumps ahead 10 minutes as soon it syncs with time.windows.com.

I’ve also changed the time manually, and have observed the same behavior.

I’ve confirmed the timezone is set correctly.

So, does anyone know why the windows time service is setting the server 10 minutes ahead?

What’s wrong with dhcpd (isc-dhcp-server) on Ubuntu 18.04? Why it does nothing?

I tried many times, on various 18.04 machines: the dhcpd executable (installed in /usr/sbin/dhcpd via package isc-dhcp-server) seemingly the only thing it does, when executed from command line, is to exit with exit code 1.

I want to execute the program manually to get interactive error messages and debug problems in the configuration.

For instance, when executing $ dhcpd --version I would expect to have at least version like in Ubuntu 16.04

$   dhcpd --version isc-dhcpd-4.3.5 $    

On Ubuntu 18.04 the dhcpd always outputs nothing to stdout, regardless of the command line options.

Another peculiar thing is that the executable itself installed in Ubuntu 18.04 is binary identical to the executable from Ubuntu 16.04. Of course, I double checked, that what I have downloaded is indeed identical to the official Ubuntu 18.04 version (and not from 16.04 sources).

It looks as I found a bug, but I can’t believe that there are bugs so conspicuous in the distribution that is almost one year old. I write here to make sure I did not make any obvious mistake.

What is this error for rootca for wrong system time?

Getting this error for openssl smime verify

140392937076368:error:21075075:PKCS7 routines:PKCS7_verify:certificate verify error:pk7_smime.c:342:Verify error:certificate is not yet valid

After changing date to – faketime -f “2017-01-01 01:00:00” bash -l

Validity is –

    Validity         Not Before: Apr  4 09:26:00 2016 GMT         Not After : Apr  4 09:26:00 2026 GMT 

Why error says certificate is not yet valid ?

Magento 2 checkout takes wrong amount with base currency

I have magento 2 store with multi currency single store. My Default currency is set to usd. I changed currency to INR Now my checkout payment shows like below “You will be charged for” shows value in USD instead of INR, how can i show value in INR there instead of USD.

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Also when i do checkout using payment gateway it show usd value with INR currency, amount should be USD 9437.64 instead of INR 9437.64

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