Pareto Optimality of Centralized Procurement Based on Genetic Algorithm

In the process of purchasing materials, small enterprises are often unable to meet the minimum availability of suppliers in the process of purchasing due to the lack of economic strength and storage capacity of goods. Therefore, they will encounter difficulties in the process of purchasing.To solve this problem, the group-led centralized procurement strategy for small enterprises has become a new craze. In this paper, we transform the problem of centralized procurement lot into a multi-objective optimization problem by establishing a multi-objective optimization model with cost, quality and logistics as sub-objectives, and use genetic algorithms to solve the multi-objective optimization problem in order to achieve Pareto optimality among each purchaser and supplier. Finally, an example of procurement by the China Energy Investment Corporation is used to verify that the multi-objective optimization model for the collection of lots constructed in this paper can effectively promote the cooperation between purchasers and suppliers, and stimulate the competitive vitality of enterprises in the market

Multi-objective optimization design of ship propulsion shafting based on the multi-attribute decision making

The expression of field transfer matrix of a ship propulsion shafting is deduced based on the modified Timoshenko beam theory using the transfer matrix method. Moreover, the power flow of each bearing of the propulsion shafting is carried out numerically. The Pareto optimal solution set is obtained by selecting the aft stern bearing stiffness, front stern bearing stiffness, thrust bearing stiffness and the bearing spacing length as the optimization design variables and selecting the sum of the power flow of each bearing of the propulsion shafting as the optimization objectives. Then, the Pareto optimal solution set is sorted by the TOPSIS method and MADM approach. The analysis results show that it is feasible and effective to avoid the blindness of selecting optimization results by optimizing the propulsion shafting multi-objectives based on the TOPSIS method and MADM approach

Analysis of Multi-Element Blended Course Teaching and Learning Mode Based on Student-Centered Concept under the Perspective of “Internet+”

The integration of Internet and education has changed students’ learning environment and affected their learning behavior, which poses a greater challenge to the traditional teaching mode. Through the SWOT analysis of the “student centered” multi-element blended teaching mode in the era of “Internet + education”, it is concluded that the adaptability of learners themselves and the mismatch between teachers’ educational ideas and this teaching model delay the development of education to a certain extent. Some suggestions are put forward, such as strengthening the supervision and guidance, implementing the teaching and learning model scientifically, improving teachers’ ideology and comprehensive quality, and making full use of the characteristics of Internet opening, sharing and collaboration to construct the public service system and platform of national educational resources

High Level of CXCR4 in Triple-Negative Breast Cancer Specimens Associated with a Poor Clinical Outcome

Despite high sensitivity to chemotherapy, the prognosis for triple-negative breast cancer (TNBC) remains poor because of its high rate of metastasis and low sensitivity to endocrine therapy. CXCR4 expression has been reported in many subtypes of human breast cancers, but it remains unknown whether CXCR4 is expressed in TNBC and whether CXCR4 expression in TNBC could be a prognostic indicator. TNBCs tissues were formalin fixed, paraffin embedded and hematoxylin-eosin (H&E) stained. Immunohistochemical staining was utilized to determine the CXCR4 expression in those specimens. Statistical analyses were performed using SPSS16.0 software to reveal the correlation of CXCR4 expression in TNBC specimens and cancer recurrence and cancer-related death. Our results showed that there was a strong association between CXCR4 overexpression and both menopause and the histological cancer grade of TNBC patients (p values were separately 0.004 and 0.001). The 5-y disease-free survival (DFS) and the 5-y overall survival (OS) were 57.69% and 58.33% for the low-CXCR4 group versus 42.11% and 44.74% for the high-CXCR4 group, respectively (p＝0.031 and 0.048). CXCR4 overexpression plays an important role in triple-negative breast cancers, and may be a predictor of poor prognosis

A Parameterization Scheme for Wind Wave Modules that Includes the Sea Ice Thickness in the Marginal Ice Zone

The global wave model WAVEWATCH III®; works well in open water. To simulate the propagation and attenuation of waves through ice-covered water, existing simulations have considered the influence of sea ice by adding the sea ice concentration in the wind wave module; however, they simply suppose that the wind cannot penetrate the ice layer and ignore the possibility of wind forcing waves below the ice cover. To improve the simulation performance of wind wave modules in the marginal ice zone (MIZ), this study proposes a parameterization scheme by directly including the sea ice thickness. Instead of scaling the wind input with the fraction of open water, this new scheme allows partial wind input in ice-covered areas based on the ice thickness. Compared with observations in the Barents Sea in 2016, the new scheme appears to improve the modeled waves in the high-frequency band. Sensitivity experiments with and without wind wave modules show that wind waves can play an important role in areas with low sea ice concentration in the MIZ.acceptedVersio