Transportation is one of the important infrastructures constituting the base and requisite for different levels of people’s access and movement to various locations. Transportation systems are one of the indices of the development of a region. Optimizing these systems contributes to improving performance and reducing costs of offering services to users. Hence, methods should be adopted with whi...

a difference in salt concentration in two solutions separated by a membrane leads to an electrical potential difference across the membrane, also without applied current. a literature study is presented on proposed theories for the origin of this membrane potential (ϕm). the most well-known theoretical description is teorell-meyer-sievers (tms) theory, which we analyze and extend. experimental ...

Mail-order and internet sellers must decide how customers pay shipping charges. Typically, these sellers choose between two pricing policies: either “uniform pricing,” where the firm delivers to any customer at a fixed delivery charge (that may be volume dependent), or “mill pricing,” where the firm bills the customer a distance-related shipping charge. This paper studies price competition betw...

scheduling is an important subject of production and operations management area. in flow-shop scheduling, the objective is to obtain a sequence of jobs which when processed in a fixed order of machines, will optimize some well defined criteria. the concept of transportation time is very important in scheduling. transportation can be done by robots. in situations that robots are used to transpor...

The stability of a user equilibrium determines whether it could be realized or sustained in a transportation network, when subject to perturbations in traffic conditions and drivers’ route choice behaviors. In this paper, with a simple deterministic dynamical system model of the traffic assignment problem, we first develop a systematic approach to analyzing asymptotic stability and instability ...

We investigate the electronic transport through a single-level quantum-dot which is capacitively coupled to a charge-qubit. By employing the method of nonequilibrium Green's functions, we calculate the electric current through quantum dot at finite bias voltages. The Green's functions and self-energies of the system are calculated perturbatively and self-consistently to the second order of inte...

We present a continuous, bilinear formulation for the fixed charge network flow problem. This formulation is used to derive an exact algorithm for the fixed charge network flow problem converging in a finite number of steps. Some preliminary computational experiments are reported to show the performance of the algorithm.

In this general equilibrium framework, the transportation sector is modeled as a distinct sector with increasing returns. A more advanced technology has a higher fixed cost but a lower marginal cost of production. Even with both manufacturing firms and transportation firms engage in oligopolistic competition and choose technologies optimally, the model is tractable and results are derived analy...

Network flow problems with non-convex piecewise linear cost structures arise in many application areas, most notably in freight transportation and supply chain management. In the present paper, we consider mixed-integer programming (MIP) formulations of a generic multi-commodity network flow problem with piecewise linear costs. The formulations we study are based on variable disaggregation tech...