Technology

  2010 MAR 9 - (VerticalNews.com) -- "Manpower scheduling problem is one of the key scheduling problems with extensive applications in manufacturing. This paper presents a mixed-integer programming model with a two-stage heuristic algorithm for solving the manpower scheduling problem in the precision engineering industry," investigators in Singapore, Singapore report.

  "Firstly, a mixed-integer programming formulation is developed to model the manpower scheduling problem in this high-mix low-volume manufacturing environment. Secondly, a two-stage heuristic algorithm is proposed where the first stage is deployed to calculate the skill requirements for each shift by considering the jobs, machines, and their production schedule and the second stage is designed to assign operators to the machines by considering the skill set requirements and the operator's expressed preferences," wrote Q.K. Pan and colleagues, Nanyang Technological University ...read more

  2010 MAR 9 - (VerticalNews.com) -- According to recent research from Adelaide, Australia, "The adaptive identification of the non-linear hysteresis and creep effects in a piezoelectric actuator is proposed in this paper. Model uncertainties related to the hysteresis and creep effects, most prominently in the high frequency zone (to 100 Hz), large operating amplitude and/long operating time, can make a piezoelectric actuator-driven micro-positioning system unstable in the closed loop. ...read more

  2010 MAR 9 - (VerticalNews.com) -- According to a study from Fukuoka, Japan, "Grating disks of a microrotary encoder are developed to measure the rotational accuracy of microgears. In gear engagement, transmission error plays an important role to grasp the meshing performance of gear pairs."

  "For measurement of transmission error of microgears, it is necessary to utilize a couple of microrotary encoders whose diameters are smaller than the reference diameter of microgears to be measured. The designed grating disk has a diameter of 1 mm, and the number of gratings is up to 1,000. It is manufactured with photo-lithography method on trial, and the grating patterns are successfully achieved homogeneously," wrote S. Kurokawa and colleagues, Kyushu University ...read more