A multi-objective integrated procurement, production, and distribution problem of supply chain network under fuzziness uncertainties

In this paper, we devoted a design under uncertainty of a four-echelon supply chain network including multiple suppliers, multiple plants, multiple distributors and multiple customers. The proposed model is a bi-objective mixed integer linear programming which considers several constraints and aims to minimize the total costs including the procurement, production, storage and distribution costs as well as to maximize on-time deliveries (OTD). To bring the model closer to real-world planning problems, the objective function coefficients (e.g. procurement cost, production cost, inventory holding and transport costs) and other parameters (e.g., demand, production capacity and safety stock level), are all considered triangular fuzzy numbers. Besides, a hybrid mathematical model-based on credibility approach is constructed for the problem, i.e., expected value and chance constrained models. Moreover, to build the crisp equivalent model, we use different property of the credibility measure. The resulted crisp equivalent model is a bi-objective mixed integer linear programs (BOMILP). To transform this crisp BOMILP into a single objective mixed integer linear programs (MILP) model, we apply three different aggregation functions. Finally, numerical results are reported for a real case study to demonstrate the efficiency and applicability of the proposed model.

S3UCA: Soft-Margin Support Vector Machine-Based Social Network User Credibility Assessment Method

Among the algorithms used to assess user credibility in social networks, most of them quantify user information and then calculate the user credibility measure by linear summation. The algorithm above, however, ignores the aliasing of user credibility results under the linear summation dimension, resulting in a low evaluation accuracy. To solve this problem, we propose a user credibility evaluation method based on a soft-margin support-vector machine (SVM). This method transforms the user credibility evaluation dimension from a linear summation dimension to a plane coordinate dimension, which reduces the evaluation errors caused by user aliasing in the classification threshold interval. In the quantization of user information, the ladder assignment method is used to process the user text information and numeric information, and the weight assignment method of information entropy is used to calculate the weight assignment among different feature items, which reduces the errors caused by the inconsistency of the order of magnitude among different types of user information. Simulation results demonstrate the superiority of the proposed method in the user’s credibility evaluation results.

Modeling and empirical analysis of regional hub-and-spoke road-rail combined transport network based on uncertain cost-time-demand

Taking into account the uncertainties of the factors of in-transit transportation cost, hub transshipment cost, hub construction cost, in-transit transportation time, hub transshipment time, and demand, this study uses triangular fuzzy numbers, expected value criteria, and distribution of credibility measure to minimise the total transportation cost of the hub-and-spoke road-rail combined transport (RRCT) network and the maximum transportation limit time between the origin and destination of the network. Firstly, a non-linear programming mathematical model is constructed for the regional hub-and-spoke RRCT network based on uncertain cost-time-demand. Then, an improved genetic algorithm is designed to obtain an optimized scheme. The algorithm uses genetic algorithm to search the global space, and uses two local search methods, i.e. shift and exchange, to search the local space. Finally, the RRCT network along the Yaan-Linzhi section of the Sichuan-Tibet Railway is used as the research object to verify the applicability and effectiveness of the regional hub-and-spoke RRCT network model and the algorithm proposed in the study.

Construction of c-credibility measure and application in insurance

Credibility theory provides a tool for modelling various phenomena in insurance. Changes in life circumstances such as the pandemic and its consequences require adjustment of old and creation of new theories that would improve existing parameters in modelling phenomena in insurance and actuarial analysis. Thus, by using c-credibility measure, we try to respond to some of the challenges that have emerged. The paper presents a summarised theory of c-credibility and gives an algorithm for constructing c-credibility measure, which is illustrated by an example.