/ Culture - Science and Technology
Practical Universal Grader for Fish Farming 
  Researchers of the Pyongyang University of Mechanical Engineering have developed a universal grader for fish farming and introduced it into reality true to the intention of the Workers' Party of Korea on putting the pisciculture on a scientific and intensive basis.
  They have made a persistent research with a goal to develop and complete the fish grader of Korean style suited to the trend of the development of fish farming.

  Doctor and Associate Professor Choe Kum Su, Deputy Dean of the University, says:
  "Generally, grading fishes properly according to their sizes from the period of fry is an important issue to raise the survival rate of fishes and increase their output. Basing ourselves on the detailed analysis and survey of the preceding technical literature, we paid attention to a grading sieve capable of sorting out fishes according to their sizes and pooled our collective wisdom to devise a new type of grading sieve.
  We made a number of simulations and structural basic tests, making it possible to optimize the structure and adjust the intervals of the sieve at will. As a result, we devised a structure which can sort out fishes of different sizes, ages and kinds and could make a highly efficient universal grader for fish farming."
  The universal grader for fish farming made by them was introduced into a number of breed-fish stations, with the result that they could increase the sorting efficiency to 99.99 percent while saving a lot of manpower and time.
  The new-type grader is much less than the previous ones in manufacturing cost, has simple structure and is convenient to use. It was highly estimated at the 35th National Sci-Tech Festival.