An Interactive Fuzzy Satisficing Method for Multiobjective Stochastic Integer Programming Problems through Simple Recourse Model

Two major approaches to deal with randomness or impression involved in mathematical programming problems have been developed. The one is called stochastic programming, and the other is called fuzzy programming. In this paper, we focus on multiobjective integer programming problems involving random variable coefficients in constraints. Using the concept of simple recourse, such multiobjective stochastic integer programming problems are transformed into deterministic ones. As a fusion of stochastic programming and fuzzy one, after introducing fuzzy goals to reflect the ambiguity of the decision maker's judgments for objective functions, we propose an interactive fuzzy satisficing method to derive a satisficing solution for the decision maker by updating the reference membership levels

Molecular Basis of the Shish-Kebab Morphology in Polymer Crystallization

In the rich and long-standing literature on the flow-induced formation of oriented precursors to polymer crystallization, it is often asserted that the longest, most extended chains are the dominant molecular species in the “shish” of the “shish-kebab” formation. We performed a critical examination of this widely held view, using deuterium labeling to distinguish different chain lengths within an overall distribution. Small-angle neutron-scattering patterns of the differently labeled materials showed that long chains are not overrepresented in the shish relative to their concentration in the material as a whole. We observed that the longest chains play a catalytic role, recruiting other chains adjacent to them into formation of the shish

Flow Behavior and Distribution of Embolus-Model Particles at the Terminal Bifurcation of the Human Internal Carotid Artery

BACKGROUND: To investigate the possible role of fluid mechanical factors in thromboembolism that occurs at a high rate in the human middle cerebral artery (MCA). METHODS: Isolated transparent cerebral arterial trees containing the terminal bifurcation of the internal carotid artery (ICA), where the ICA bifurcated into the MCA and the anterior cerebral artery, were prepared from human cadavers. The flow behavior and distribution of embolus-model polystyrene particles in dilute suspensions at the bifurcation were studied in detail by means of flow visualization and high-speed cinemicrographic techniques. RESULTS: Large particles in suspensions flowing through the ICA migrated radially away from the vessel wall toward the axis of the ICA. It became more remarkable by increasing the flow rate in the ICA (Q(0)), flow rate ratio of Q(1) to Q(0) (MCA/ICA), and particle diameter. As a result, redistribution of particles flowing in the ICA occurred at the bifurcation. The particles >1 mm in diameter (approximate to 1/4 of vessel diameter) selectively entered the MCA, even when the flow rate ratio of Q(1) to Q(0) was decreased to as low as 0.34. In contrast, the particles whose diameters were <0.3 mm (approximate to 1/10 of vessel diameter) and that did not show radial migration entered the MCA at the same rate as the flow rate ratio of Q(1) to Q(0). CONCLUSIONS: Due to the flow-dependent migration of particles away from the vessel wall toward the axis of the ICA, large particles selectively enter the MCA to which the core flow of the ICA is generally directed. This might explain why the incidence of thromboembolism is higher in the MCA than in the anterior cerebral artery in humans