Darius Bufnea – Darius Bufnea, PhD, Assoc. Prof.

A Dataset for Evaluating Query Suggestion Algorithms in Information Retrieval

October 1, 2019Darius Bufnea

published in Proceedings of the 27th International Conference on Software, Telecommunications and Computer Networks (SoftCOM), pp. 1-6, DOI: 10.23919/SOFTCOM.2019.8903906, September 19-21, 2019, Split, Croatia. Cite as

I. Bădărînză, A. Sterca and D. Bufnea, "A Dataset for Evaluating Query Suggestion Algorithms in Information Retrieval", 2019 International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2019, pp. 1-6, doi: 10.23919/SOFTCOM.2019.8903906

1	I. Bădărînză, A. Sterca and D. Bufnea, "A Dataset for Evaluating Query Suggestion Algorithms in Information Retrieval", 2019 International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2019, pp. 1-6, doi: 10.23919/SOFTCOM.2019.8903906

Full paper A Dataset for Evaluating Query Suggestion Algorithms in Information Retrieval Authors… Continue Reading →

Multi-way Divide and Conquer Parallel Programming based on PLists

September 30, 2019Darius Bufnea

published in Proceedings of the 27th International Conference on Software, Telecommunications and Computer Networks (SoftCOM), pp. 1-6, DOI: 10.23919/SOFTCOM.2019.8903794, September 19-21, 2019, Split, Croatia. Cite as

V. Niculescu, D. Bufnea, A. Sterca and R. Silimon, "Multi-way Divide and Conquer Parallel Programming based on PLists", 2019 International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2019, pp. 1-6, doi: 10.23919/SOFTCOM.2019.8903794

1	V. Niculescu, D. Bufnea, A. Sterca and R. Silimon, "Multi-way Divide and Conquer Parallel Programming based on PLists", 2019 International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2019, pp. 1-6, doi: 10.23919/SOFTCOM.2019.8903794

Full paper Multi-way Divide and Conquer Parallel Programming based on PLists Authors Virginia… Continue Reading →

MPI Scaling Up for Powerlist Based Parallel Programs

February 18, 2019Darius Bufnea

published in Proceedings of the 27th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (PDP 2019), pp. 199-204, DOI: 10.1109/EMPDP.2019.8671597, February 13-15, 2019, Pavia, Italy. Cite as

V. Niculescu, D. Bufnea and A. Sterca, "MPI Scaling Up for Powerlist Based Parallel Programs", 2019 27th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (PDP), 2019, pp. 199-204, doi: 10.1109/EMPDP.2019.8671597

1	V. Niculescu, D. Bufnea and A. Sterca, "MPI Scaling Up for Powerlist Based Parallel Programs", 2019 27th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (PDP), 2019, pp. 199-204, doi: 10.1109/EMPDP.2019.8671597

Full paper MPI Scaling Up for Powerlist Based Parallel Programs Authors… Continue Reading →

A Community Driven Approach for Click Bait Reporting

October 1, 2018Darius Bufnea

published in Proceedings of the 26th International Conference on Software, Telecommunications and Computer Networks (SoftCOM), pp. 1-6, DOI: 10.23919/SOFTCOM.2018.8555759, September 13-15, 2018, Split – Supetar (Island of Brac), Croatia Cite as

D. Bufnea and D. Şotropa, "A Community Driven Approach for click Bait Reporting", 2018 26th International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2018, pp. 1-6, doi: 10.23919/SOFTCOM.2018.8555759

1	D. Bufnea and D. Şotropa, "A Community Driven Approach for click Bait Reporting", 2018 26th International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2018, pp. 1-6, doi: 10.23919/SOFTCOM.2018.8555759

Full paper A Community Driven Approach for Click… Continue Reading →

User authentication in Java using the IMAP or SMTP protocols

March 3, 2018Darius Bufnea

Recently, a couple of students have asked me the same question: “I need to authenticate users (other students) in my diploma thesis application with their faculty credentials. Is there a way to do this?” The faculty student server (i.e. www.scs.ubbcluj.ro)… Continue Reading →

A Java Framework for High Level Parallel Programming using Powerlists

January 15, 2018Darius Bufnea

published in Proceedings of the 18th International Conference on Parallel and Distributed Computing, Applications and Technologies (PDCAT’17), pp. 255-262, DOI: 10.1109/PDCAT.2017.00049, December 18-20, 2017, Taipei, Taiwan. Cite as

V. Niculescu, F. Loulergue, D. Bufnea and A. Sterca, "A Java Framework for High Level Parallel Programming Using Powerlists", 2017 18th International Conference on Parallel and Distributed Computing, Applications and Technologies (PDCAT), 2017, pp. 255-262, doi: 10.1109/PDCAT.2017.00049

1	V. Niculescu, F. Loulergue, D. Bufnea and A. Sterca, "A Java Framework for High Level Parallel Programming Using Powerlists", 2017 18th International Conference on Parallel and Distributed Computing, Applications and Technologies (PDCAT), 2017, pp. 255-262, doi: 10.1109/PDCAT.2017.00049

Full paper A Java Framework for High Level Parallel Programming using… Continue Reading →

Measuring and Visualizing the Scrappiness Level of a Website

October 1, 2017Darius Bufnea

published in Proceedings of the 19th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing – SYNASC 2017, pp. 304-311, DOI: 10.1109/SYNASC.2017.00057, September 21-24, 2017, Timișoara, Romania Cite as

D. Bufnea and D. Sotropa, "Measuring and Visualizing the Scrappiness Level of a Website", 2017 19th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (SYNASC), 2017, pp. 304-311, doi: 10.1109/SYNASC.2017.00057

1	D. Bufnea and D. Sotropa, "Measuring and Visualizing the Scrappiness Level of a Website", 2017 19th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (SYNASC), 2017, pp. 304-311, doi: 10.1109/SYNASC.2017.00057

Full paper Measuring and Visualizing the Scrappiness Level of… Continue Reading →

Experience with Teaching PDC Topics into Babeş-Bolyai University’s CS Courses

June 15, 2017Darius Bufnea

published in Proceedings of the EuroPar 2017: Parallel Processing Workshops, pp. 240-251, DOI: 10.1007/978-3-319-75178-8_20, Lecture Notes in Computer Science, vol 10659. Springer, Cham. Cite as

Niculescu V., Bufnea D. (2018) Experience with Teaching PDC Topics into Babeş-Bolyai University’s CS Courses. In: Heras D. et al. (eds) Euro-Par 2017: Parallel Processing Workshops. Euro-Par 2017. Lecture Notes in Computer Science, vol 10659. Springer, Cham. https://doi.org/10.1007/978-3-319-75178-8_20

1

Niculescu V., Bufnea D. (2018) Experience with Teaching PDC Topics into Babeş-Bolyai University’s CS Courses. In: Heras D. et al. (eds) Euro-Par 2017: Parallel Processing Workshops. Euro-Par 2017. Lecture Notes in Computer Science, vol 10659. Springer, Cham. https://doi.org/10.1007/978-3-319-75178-8_20

Pre-print paper Experience with Teaching PDC Topics into Babeş-Bolyai University’s CS Courses This is… Continue Reading →

Babeș-Bolyai University’s High Performance Computing Center

November 11, 2016Darius Bufnea

published in Studia Universitatis Babeş-Bolyai, Seria Informatica, Vol. LXI, No. 2, pp. 54-69, 2016. Cite as

D. Bufnea, V. Niculescu, Gh. Silaghi, A. Sterca, "Babeş-Bolyai University's High Performance Computing Center", in Studia Universitatis Babeş-Bolyai, Seria Informatica, Vol. LXI, No. 2, pp. 54-69, 2016

1	D. Bufnea, V. Niculescu, Gh. Silaghi, A. Sterca, "Babeş-Bolyai University's High Performance Computing Center", in Studia Universitatis Babeş-Bolyai, Seria Informatica, Vol. LXI, No. 2, pp. 54-69, 2016

Full paper Babeș-Bolyai University’s High Performance Computing Center Authors Darius Bufnea*, Virginia Niculescu*, Gheorghe Silaghi**, Adrian Sterca* * Department of Computer Science, Faculty… Continue Reading →

Matrix multiplication using threads

March 13, 2015Darius Bufnea

Save the following lines of code in a file called matrix_multiplication.c, then compile and run it:

$ gcc -o matrix_multiplication matrix_multiplication.c -lpthread
$ ./matrix_multiplication

1 2	$ gcc -o matrix_multiplication matrix_multiplication.c -lpthread $ ./matrix_multiplication

I would recommend running in parallel the top command in another shell window to observe the system/processors load.

#include <pthread.h>
#include <stdio.h>
#include <time.h>

// use 4 for a quad processor, but try also with 1 and 2 threads
// to check the running time and the system load
#define thread_count 4

// matrix dimension
#define dim 1500

struct param {
  int start_line, end_line;
};

int a[dim][dim], b[dim][dim], c[dim][dim];

void init_matrix(int m[dim][dim]) {
   int i, j;
   for (i = 0; i < dim; i++)
     for (j = 0; j < dim; j++)
       m[i][j] = random() % 100;
}

void* thread_function(void *v) {
  struct param *p = (struct param *) v;
  
  int i, j, k;
  for (i = p->start_line; i < p->end_line; i++)
    for (j = 0; j < dim; j++) {
      int s = 0;
      for (k = 0; k < dim; k++)
        s += a[i][k] * b[k][j];
      c[i][j] = s;
    }
}

int main() {
  int i;
  struct param params[thread_count];
  pthread_t t[thread_count];
  
  srand(getpid());
  int start_time, end_time;
  
  init_matrix(a);
  init_matrix(b);
  
  start_time = time(NULL);

  for (i = 0; i < thread_count; i++) {
    int code;
    params[i].start_line = i * (dim / thread_count);
    params[i].end_line = (i + 1) * (dim / thread_count);
    
    code = pthread_create(&t[i], NULL, thread_function, &params[i]);
    if (code != 0)
      printf("Error starting thread %d\n", i);
  }
  
  for (i = 0; i < thread_count; i++) 
    pthread_join(t[i], NULL);
  
  end_time = time(NULL);
  
  printf("Running time: %d\n", end_time - start_time);
}

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#include <pthread.h>

#include <stdio.h>

#include <time.h>

// use 4 for a quad processor, but try also with 1 and 2 threads

// to check the running time and the system load

#define thread_count 4

// matrix dimension

#define dim 1500

struct param {

int start_line, end_line;

};

int a[dim][dim], b[dim][dim], c[dim][dim];

void init_matrix(int m[dim][dim]) {

int i, j;

for (i = 0; i < dim; i++)

for (j = 0; j < dim; j++)

m[i][j] = random() % 100;

}

void* thread_function(void *v) {

struct param *p = (struct param *) v;

int i, j, k;

for (i = p->start_line; i < p->end_line; i++)

for (j = 0; j < dim; j++) {

int s = 0;

for (k = 0; k < dim; k++)

s += a[i][k] * b[k][j];

c[i][j] = s;

}

int main() {

int i;

struct param params[thread_count];

pthread_t t[thread_count];

srand(getpid());

int start_time, end_time;

init_matrix(a);

init_matrix(b);

start_time = time(NULL);

for (i = 0; i < thread_count; i++) {

int code;

params[i].start_line = i * (dim / thread_count);

params[i].end_line = (i + 1) * (dim / thread_count);

code = pthread_create(&t[i], NULL, thread_function, &params[i]);

if (code != 0)

printf("Error starting thread %d\n", i);

}

for (i = 0; i < thread_count; i++)

pthread_join(t[i], NULL);

end_time = time(NULL);

printf("Running time: %d\n", end_time - start_time);

}