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This paper investigates a coastal shuttle tanker inventory routing problem. We convert the problem into a vehicle routing problem with time windows by using the discrete tanker loaded quantity and ...

Objective. The purpose of this study was to investigate the therapeutic effect of orthodontic treatment on anterior tooth displacement caused by periodontal disease. Methods. A prospective study was performed in 86 patients with anterior tooth displacement caused by periodontal disease. These patients were divided into the experimental group and the control group according to the intervention methods. For the control group, patients were treated with conventional therapy. The experimental group used straight wire orthodontic technique for orthodontic treatment on the basis of conventional treatment. Comparisons were performed between two groups in term of bleeding index, alveolar bone height, anterior tooth coverage, periodontal pocket depth, probing depth, clinical crown length, tooth root length, inflammatory cytokines levels, and orthodontic satisfaction. Results. Comparison of bleeding index, alveolar bone height, anterior tooth coverage, periodontal pocket depth, probing depth, clinical crown length, tooth root length, and inflammatory cytokines levels between two groups before treatment indicated that there were no statistical differences (all P > 0.05 ). After treatment, bleeding index, alveolar bone height, anterior tooth coverage, periodontal pocket depth, probing depth, clinical crown length, and serum levels of IL-6 and TNF-α in the experimental group were lower than those in the control group (all P < 0.05 ), while the serum level of IL-2 in the experimental group was more than that in the control group ( P < 0.05 ). Also, there was no difference for tooth root length between two groups. Moreover, compared with the control group, orthodontic satisfaction in the experimental group was significantly increased. Conclusion. The efficacy of orthodontic treatment in patients with anterior tooth displacement caused by periodontal disease is higher than that of only using conventional therapy, as it helps improve their periodontal health, alveolar bone height, clinical crown length, inflammatory factor levels, and orthodontic satisfaction of patients.

The near-sea off-shore oil extraction and transportation system use heterogeneous fleets to transfer crude oil from the floating production storage and offloading to the land-based oil storage port. Based on the characteristics of this system, the short sea inventory routing problem is investigated considering the shuttle tanker fleet and inventory management. In order to minimize the total operation cost and maximize the system reliability, a semi-continuous model for the shuttle tanker scheduling problem is established. The model optimizes the tanker scheduling plan and the design of the tanker fleet. To solve the complex model, this article proposes an improved non-dominated sorting genetic algorithm with differential evolution operator to solve the optimization of the multi-objective model. This research also uses public vessel operation data to test the modeling and optimizing efficiency. The Pareto Fronts associated with the total operation cost and the system reliability from the optimization outcome is analyzed to provide scheduling priority advice. The results indicate that proposed optimization algorithms are effective, and the operation could be optimized with the proposed model and algorithm. Refereed/Peer-reviewed

In this paper, a bi-level programming model is established to solve the decision problem of the departure port tax rebate policy (DPTRP). Based on the theory of user equilibrium, the model can opti...

Green scheduling is an important means to achieve sustainable industrial development and enhance the green efficiency of enterprises. Given the characteristics of a modern crude oil supply system, the shuttle tanker fleet green scheduling problem (FGSP) is discussed considering a carbon tax and variable tanker speed factor. To minimize the green operating cost (i.e., sum of general operating cost and carbon tax) of the tanker fleet, an integer programming model for shuttle tanker fleet green scheduling (FGSM) is established. The FGSM optimizes the number and sizes of tankers, the number and positions of floating production storage and offloading units (FPSO) at which to berth and the scheduling plan (i.e., berthing order and sailing speed) of each tanker in the fleet. Based on the column generation algorithm, a shuttle tanker fleet green scheduling algorithm is designed to solve the above model accurately. The experimental results show that considering the speed factor, the green operating cost of an example fleet decreases. For different carbon tax rates, speed optimization is an effective way to reduce the green operating cost of the fleet. The above results also show that the FGSM and algorithm can effectively solve the FGSP, improve the operation level and efficiency, and reduce the green operating cost of oil companies.

The quantity of electrical coal transported through the tramp shipping network is increasing due to the high demands. This trend has increased the scheduling difficulty combined with the underdevelopment of the private thermal power plant port. The high coal consumption and low port storage capacity requires the scheduling of the tramp ship to be on a strict time window to ensure the continuous operation of the thermal power plant. The low port unloading capacity often leads to the port congestion and delay of the unloading operation. This paper develops a mixed-integer-programming model for the optimization of the tramp ship scheduling to reduce the total operation cost, including the transportation cost and the unloading waiting cost, and the branch-and-price algorithm is adopted to solve this large-scale model. The model and algorithm are tested with historical operation data from the thermal power plant in the southern coastal areas of China. The optimized scheme significantly reduces the total operation cost by reducing the unloading waiting time and the number of active vessels in certain periods. The results also demonstrate the algorithm improvement in the aspects of the optimization quality and efficiency comparing with the heuristic solution.

According to the speed-test principle of high-speed motion object, a method has been proposed which uses electromagnetic sensor. On the basis of the test requirements, analyzing the principle of electromagnetic induction, and designing an electromagnetic sensor which can meet the requirement. The magnetic dipole model of magnetic projectile is established in the process of analyzing to analyze the electromotive force produced by induction coil when crossing the electromagnetic sensor in the test tube and the changing of motion object caused by the volume changing of gas. At last verifying the feasibility of electromagnetic sensor by means of simulated and real experiment, and analyzing factors influencing the precision of testing.