A novel discrete network design problem formulation and its global optimization solution algorithm

Conventional discrete transportation network design problem deals with the optimal decision on new link addition, assuming the capacity of each candidate link addition is predetermined and fixed. In this paper, we address a novel yet general discrete network design problem formulation that aims to determine the optimal new link addition and their optimal capacities simultaneously, which answers the questions on whether a new link should be added or not, and if added, what should be the optimal link capacity. A global optimization method employing linearization, outer approximation and range reduction techniques is developed to solve the formulated model.postprin

Fabrication of Three-Dimensional Concave or Convex Shell Structures with Shell Elements at Micrometer Resolution in SU-8

This chapter presents a photo-lithographically-based technology for mass production of three-dimensional (3D) micro-structures with shell elements. In this technology, shell elements are photo-lithographically fabricated at micron or sub-micron resolution by illuminating with ultraviolet light radiating an ultraviolet light beam onto UV-opaque SU-8 monomer. The technology does not require any steps involving micro-injection molding or micro-stereolithography. Several prototypes have been fabricated to demonstrate the feasibility of this technology

Identification of critical combination of vulnerable links in transportation networks – a global optimisation approach

This paper presents a global optimisation framework for identifying the most critical combination of vulnerable links in a transportation network. The problem is formulated as a mixed-integer non-linear programme with equilibrium constraints, aiming to determine the combination of links whose deterioration would induce the most increase in total travel cost in the network. A global optimisation solution method applying a piecewise linearisation approach and range-reduction technique is developed to solve the model. From the numerical results, it is interesting and counterintuitive to note that the set of most vulnerable links when simultaneous multiple-link failure occurs is not simply the combination of the most vulnerable links with single-link failure, and the links in the critical combination of vulnerable links are not necessarily connected or even in the neighbourhood of each other. The numerical results also show that the ranking of vulnerable links will be significantly affected by certain input parameters

Elastic demand dynamic network user equilibrium: Formulation, existence and computation

This paper is concerned with dynamic user equilibrium with elastic travel demand (E-DUE) when the trip demand matrix is determined endogenously. We present an infinite-dimensional variational inequality (VI) formulation that is equivalent to the conditions defining a continuous-time E-DUE problem. An existence result for this VI is established by applying a fixed-point existence theorem (Browder, 1968) in an extended Hilbert space. We present three computational algorithms based on the aforementioned VI and its re-expression as a differential variational inequality (DVI): a projection method, a self-adaptive projection method, and a proximal point method. Rigorous convergence results are provided for these methods, which rely on increasingly relaxed notions of generalized monotonicity, namely mixed strongly-weakly monotonicity for the projection method; pseudomonotonicity for the self-adaptive projection method, and quasimonotonicity for the proximal point method. These three algorithms are tested and their solution quality, convergence, and computational efficiency are compared. Our convergence results, which transcend the transportation applications studied here, apply to a broad family of VIs and DVIs, and are the weakest reported to date

Design and analysis of magnet proportioning for dual-memory machines

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Paired box 6 gene delivery preserves beta cells and improves islet transplantation efficacy

Loss of pancreatic beta cells is the central feature of all forms of diabetes. Current therapies fail to halt the declined beta cell mass. Thus, strategies to preserve beta cells are imperatively needed. In this study, we identified paired box 6 (PAX6) as a critical regulator of beta cell survival. Under diabetic conditions, the human beta cell line EndoC-βH1, db/db mouse and human islets displayed dampened insulin and incretin signalings and reduced beta cell survival, which were alleviated by PAX6 overexpression. Adeno-associated virus (AAV)-mediated PAX6 overexpression in beta cells of streptozotocin-induced diabetic mice and db/db mice led to a sustained maintenance of glucose homeostasis. AAV-PAX6 transduction in human islets reduced islet graft loss and improved glycemic control after transplantation into immunodeficient diabetic mice. Our study highlights a previously unappreciated role for PAX6 in beta cell survival and raises the possibility that ex vivo PAX6 gene transfer into islets prior to transplantation might enhance islet graft function and transplantation outcome

Deformation and mechanical properties of quaternary blended cements containing ground granulated blast furnace slag, fly ash and magnesia

Shrinkages of cementitious materials may lead to cracking under restrained conditions. This study was motivated to develop non-shrinkage quaternary blended cements through blending slag and fly ash with Portland cement containing reactive MgO. The hydration process, autogenous shrinkage at early age, long-term volume deformation, mechanical properties, and microstructure of cement specimens were investigated. Results showed that the autogenous shrinkage of the cement pastes was effectively mitigated due to the compensation of the MgO present and the reduction of cement content owing to the partial replacements with slag and fly ash. The mechanical strengths of the blended cement mortars were lower than that of the corresponding plain Portland cement mortars at early age of 3 d, but increased significantly to be similar or higher at late ages of 28 d and 90 d. This is attributed to the microstructure densification and the interface microstructure enhancement due to the reaction of SCMs with clinker phases.The financial support from the Royal Academy of Engineering UK/China Exchange (12/13RECI013), the National Key Technology R&D Program (2011BAE27B01-1), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and the National Natural Science Foundation of China (51461135003) is acknowledged.This is the accepted manuscript. The final published version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0008884615000319

Tetramethylpyrazine attenuates oleic acid-induced acute lung injury/acute respiratory distress syndrome through the downregulation of nuclear factor-kappa B (NF-kB) activation in rats

The aim of this study was to investigate the anti-inflammatory activities of tetramethylpyrazine (TMP) in the mice model of acute lung injury/acute respiratory distress syndrome (ALI/ARDS) induced by oleic acid (0.15 ml/kg, intravenous (i.v.)). We report here that TMP (given at 160 mg/kg intraperitoneal (i.p.)) exerts potent anti-inflammatory effects in this model. After 4, 8 and 12 h, animal model reaction was observed and bronchoalveolar lavage fluid was obtained to measure proinflammatory cytokines (tumor necrosis factor α, interleukin 1β) and proteins by enzyme-linked immunosorbent assay and bicinchoninic acid protein assay kit, respectively. The protein expression of NF-kB in the lung was measured by immunohistochemistry and Western blotting. The results showed an increase in tumor necrosis factor α and interleukin 1β in the ALI/ARDS rat models. The activation of NF-kB was suppressed by TMP in the ALI/ARDS rats. The suppression of those molecules is controlled by NF-kB. These findings support the hypothesis that TMP inhibits the inflammatory process in the lung tissue through the suppression of NF-kB activation. Nevertheless, further investigations are required to determine the potential clinical usefulness of TMP in the adjunctive therapy for ARDS.Key words: Tetramethylpyrazine, acute lung injury/acute respiratory distress syndrome, inflammatory factors, NF-kB