Customer Retention Based on the Number of Purchase: A Data Mining Approach

ABSTRACT Purpose: this paper aimed at finding the relationship between the numbers of purchase and the customer's income. The data mining tools were applied in the study to find those customers who bought more than one life insurance policy and represented the signs of good payments at the same time. Design/ methodology/ approach: in the present research the data mining tools were employed based on CRISP-DM methodology. The K-means algorithm was used for classification and the prediction was based on a proposed formula in Excel worksheet. Findings: the researcher extracted some simple rules to predict customers' clusters through selecting the customers who bought more than one policy and filtering the income-bringer customers as the companies would be able to use this prediction to change their strategies in relation to different customers. Originality/value: Utilizing data mining tools to classify different customers in life insurance and prediction based on the classification were new approaches of the study. There was not enough research and implementation in relation to the CRM and data mining in the insurance industry in Iran. Especially CRISP-DM methodology was not used extensively enough in a life insurance investigation

Beyond 8 THz Displacement-field Nano-switches for 5G and 6G Communications

The rapid progress in high capacity communication systems is reaching extremely high data rates of 100 Gb s−1, which demands electronic switches with cut-off frequencies well above 1 THz. The excellent electron transport properties of III-V heterojunctions could potentially enable terahertz devices, however, the high parasitic capacitances and contact resistances in traditional ultra-scaled electronic devices, such as transistors and diodes, hinder their potential. Here we demonstrate that the fast switching of displacement fields strongly confined in a few-nanometers-thin crystal between a textured metal and an electron sheet, so called displacement-field nano-switch, can provide cut-off frequencies above 8 THz, enabling an efficient switching of terahertz signals. The device offers extremely low ON state resistances approaching 100 Ω μm, low parasitic capacitances in range of 100 aF μm−1, excellent impedance matching capability, and fast switching times down to 10 ps. We demonstrate the application of these devices for high data rate modulation and mixing. The outstanding performance and integration capability of displacement-field nano-switches pave the way towards mm-wave and terahertz integrated circuits with applications in 5G and 6G communications, among others

Delivery of Bone Marrow-Derived Mesenchymal Stem Cells Improves Tear Production in a Mouse Model of Sjögren’s Syndrome

The purpose of the present study was to test the potential of mouse bone marrow-derived mesenchymal stem cells (BD-MSCs) in improving tear production in a mouse model of Sjögren’s syndrome dry eye and to investigate the underlying mechanisms involved. NOD mice (n=20) were randomized to receive i.p. injection of sterile phosphate buffered saline (PBS, control) or murine BD-MSCs (1 × 106 cells). Tears production was measured at baseline and once a week after treatment using phenol red impregnated threads. Cathepsin S activity in the tears was measured at the end of treatment. After 4 weeks, animals were sacrificed and the lacrimal glands were excised and processed for histopathology, immunohistochemistry, and RNA analysis. Following BD-MSC injection, tears production increased over time when compared to both baseline and PBS injected mice. Although the number of lymphocytic foci in the lacrimal glands of treated animals did not change, the size of the foci decreased by 40.5% when compared to control animals. The mRNA level of the water channel aquaporin 5 was significantly increased following delivery of BD-MSCs. We conclude that treatment with BD-MSCs increases tear production in the NOD mouse model of Sjögren’s syndrome. This is likely due to decreased inflammation and increased expression of aquaporin 5