Production Line Capacity Planning Concerning Uncertain Demands for a Class of Manufacturing Systems with Multiple Products

In this paper, we study a class of manufacturing systems which consist of multiple plants and each of the plants has capability of producing multiple distinct products. The production lines of a certain plant may switch between producing different kinds of products in a time-sharing mode. We optimize the capacity configuration of such a system s production lines with the objective to maximize the overall profit in the capacity planning horizon. Uncertain demand is incorporated in the model to achieve a robust configuration solution. The optimization problem is formulated as a nonlinear polynomial stochastic programming problem, which is difficult to be efficiently solved due to demand uncertainties and large search space. We show the NP-hardness of the problem first, and then apply ordinal optimization(OO) method to search for good enough designs with high probability. At lower level, an mixed integer programming(MIP) solving tool is employed to evaluate the performance of a design under given demand profile.

A Broad View of the Chang'e 2 Mission

China's second lunar explora- tion satellite Chang'e 2 was launched on October 1 2010 from the Xichang Satellite Launch Center. The satellite was sent directly into an Earth-moon transfer orbit on a LM-3C launch vehicle. Five

Developing Prototype Simulants for Surface Materials and Morphology of Near Earth Asteroid 2016 HO3

There are a variety of applications for asteroid simulants in asteroid studies for science advances as well as technology maturation.For specific purpose,it usually requires purpose-specialized simulant.In this study,we designed and developed a set of prototype simulants as S-type asteroid surface materials analogue based on H,L,and LL ordinary chondrites’mineralogy and terrestrial observations of near-earth asteroid 2016 HO3,which is the Chinese sample return mission target.These simulants are able to simulate morphology and reflectance characteristics of asteroid(469219)2016 HO3 and,thus,to be used for engineering evaluation of the optical navigation system and the sampling device of the spacecraft during the mission phase.Meanwhile,these prototype simulants are easily to modify to reflect new findings on the asteroid surface when the spacecraft makes proximate observations.

Mathematical prototypes for collocating geostationary satellites

Collocating geostationary satellites sharing the same position is much demanded for satellite operation recently,the separation strategies are adopted to safeguard the satellites collocated of leaving the relative distance beyond collision with different sets of orbit parameters.This paper presents the mathematical prototypes which establish the allowable relative distance with uncertainty of orbital determination(OD),as well as the orbital element offset for each pair of collocated satellites,and puts forward algorithms to build such relationship to face the challenge of putting three satellites sharing the same position,the algorithms to allocate the longitude,eccentricity and inclination for each satellite are also given to ascertain that the mathematical prototypes are the guide specification to design collocation strategy for geostationary satellites.