A customer segmentation framework for targeted marketing in telecommunication

© 2017 IEEE. Telecommunication industry is highly competitive, and mass marketing is not applicable anymore. Moreover, Mobile customers have different behaviors that urge telecom industries to differentiate their strategies to meet customers' needs. At the same time, mobile operators have an enormous amount of customer records, and data-driven approaches can help them to draw insights from this huge amount of data. Therefore, a data-driven segmentation approach can support marketing strategies to tailor their marketing plans. In this research, we adopt behavior and beneficial segmentation in a two-dimensional framework to segment customers. The results indicate that our method has an outstanding performance for customer segmentation. Moreover, we have recommended some marketing strategies based on each segment's behavior with the aim of increasing in Average Revenue Per User (ARPU) and decreasing in marketing expenses

Credit risk prediction in an imbalanced social lending environment

© 2018, the Authors. Credit risk prediction is an effective way of evaluating whether a potential borrower will repay a loan, particularly in peer-to-peer lending where class imbalance problems are prevalent. However, few credit risk prediction models for social lending consider imbalanced data and, further, the best resampling technique to use with imbalanced data is still controversial. In an attempt to address these problems, this paper presents an empirical comparison of various combinations of classifiers and resampling techniques within a novel risk assessment methodology that incorporates imbalanced data. The credit predictions from each combination are evaluated with a G-mean measure to avoid bias towards the majority class, which has not been considered in similar studies. The results reveal that combining random forest and random under-sampling may be an effective strategy for calculating the credit risk associated with loan applicants in social lending markets

Dietary fat and corticosterone levels are contributing factors to meal anticipation

Daily restricted access to food leads to the development of food anticipatory activity and metabolism, which depends upon an as yet unidentified food-entrainable oscillator(s). A premeal anticipatory peak in circulating hormones, including corticosterone is also elicited by daily restricted feeding. High-fat feeding is associated with elevated levels of corticosterone with disrupted circadian rhythms and a failure to develop robust meal anticipation. It is not clear whether the disrupted corticosterone rhythm, resulting from high-fat feeding contributes to attenuated meal anticipation in high-fat fed rats. Our aim was to better characterize meal anticipation in rats fed a low- or high-fat diet, and to better understand the role of corticosterone in this process. To this end, we utilized behavioral observations, hypothalamic c-Fos expression, and indirect calorimetry to assess meal entrainment. We also used the glucocorticoid receptor antagonist, RU486, to dissect out the role of corticosterone in meal anticipation in rats given daily access to a meal with different fat content. Restricted access to a low-fat diet led to robust meal anticipation, as well as entrainment of hypothalamic c-Fos expression, metabolism, and circulating corticosterone. These measures were significantly attenuated in response to a high-fat diet, and animals on this diet exhibited a postanticipatory rise in corticosterone. Interestingly, antagonism of glucocorticoid activity using RU486 attenuated meal anticipation in low-fat fed rats, but promoted meal anticipation in high-fat-fed rats. These findings suggest an important role for corticosterone in the regulation of meal anticipation in a manner dependent upon dietary fat content

Experimental and Numerical Investigation of the Efficiency and Pressure Drop of an Inertial Impactor with Variable Area

The deposition efficiency and pressure drop of inertial impactor with variable area has been studied numerically and experimentally. The effect of volumetric flow rate, vertical barrier, oblique barrier and flexible concave plate versus deposition and impaction efficiency and pressure drop is investigated. Numerical simulation is carried out with DPM (discrete phase method) and turbulent model of SST k-ω. To validate the numerical results a special test rig is designed to study the deposition efficiency of engine oil droplets (blow-by) with a diameter of 0.1 to 6 µm. Experimental Tests are done in 8, 12, 16 and 20 L/min. To ensure the accuracy of the experimental results, all the tests are repeated at least three times for each volumetric flow rate. Gravimetric method is implemented to calculate the deposition efficiency. According to the results, the deposition efficiency is obtained between 73 and 94 percent for different mentioned impactors and different volumetric flow rate. The numerical results are confirmed by experimental results. Using the barriers increase the efficiency maximum 6 percent in different volumetric flow rate. The results show that by reducing the distance between the vertical barrier and the outlet of nozzle, the deposition and impaction efficiency are increased. Also, the Concave flexible plate with vertical barrier located at 1 mm from the outlet of nozzle is the most efficient case

Reversible energy absorption of elasto-plastic auxetic, hexagonal, and AuxHex structures fabricated by FDM 4D printing

The present study aims at introducing reconfigurable mechanical metamaterials by utilising four-dimensional (4D) printing process for recoverable energy dissipation and absorption applications with shape memory effects. The architected mechanical metamaterials are designed as a repeating arrangement of re-entrant auxetic, hexagonal, and AuxHex unit-cells and manufactured using 3D printing fused deposition modelling process. The AuxHex cellular structure is composed of auxetic re-entrant and hexagonal components. Architected cellular metamaterials are developed based on a comprehension of the elasto-plastic features of shape memory polylactic acid materials and cold programming deduced from theory and experiments. Computational models based on ABAQUS/Standard are used to simulate the mechanical properties of the 4D-printed mechanical metamaterials under quasi-static uniaxial compression loading, and the results are validated by experimental data. Research trials show that metamaterial with re-entrant auxetic unit-cells has better energy absorption capability compared to the other structures studied in this paper, mainly because of the unique deformation mechanisms of unit-cells. It is shown that mechanical metamaterials with elasto-plastic behaviors exhibit mechanical hysteresis and energy dissipation when undergoing a loading-unloading cycle. It is experimentally revealed that the residual plastic strain and dissipation processes induced by cold programming are completely reversible through simple heating. The results and concepts presented in this work can potentially be useful towards 4D printing reconfigurable cellular structures for reversible energy absorption and dissipation engineering applications

Effect of temperature on life table parameters of Diaphania indica (Lep.: Pyralidae) under laboratory conditions

The cucumber moth, Diaphania indica (Saunders), is a tropical and sub-tropical pest on cucurbits and a key pest of greenhouse crops in Jiroft region of Iran. The effect of temperature on life table parameters of this pest was investigated in a growth chamber at four constant temperatures i.e. 20, 25, 30 and 35 ºC on Cucumis sativus L. The net reproductive rates (R0) were found to be 68.19, 120.977, 64.05 and 21.23, respectively. The intrinsic rates of increase (rm) were 0.0619, 0.1746, 0.1934 and 0.1491, and mean generation times (T) were 69.063, 27.45, 21.49 and 20.44, respectively. According to the results, for the intrinsic rate of increase (rm), finite rate of increase (λ) and intrinsic birth rate (b), the optimum temperature was 30 ºC and the least suitable temperature was 20 ºC

Metamaterial boat fenders with supreme shape recovery and energy absorption/dissipation via FFF 4D printing

In maritime transportation, a fender acts like a bumper to absorb the kinetic energy of a boat berthing against a jetty, pier wall, or other boats. They have high energy absorption and low reaction forces, preventing damage to boats and berthing structures. The aim of this paper is to introduce a novel conceptual design for a new class of lightweight boat-fendering systems with superior energy absorption/dissipation and shape recovery features. Different metamaterials with honeycomb, re-entrant, and re-entrant chiral auxetic patterns are designed in the form of boat fender panels, and their thermo-mechanical behaviors are analyzed experimentally and numerically. A finite element modeling (FEM) is developed to investigate the compressive behaviors of boat fenders. Some of designs are 4D printed by fused filament fabrication of shape memory polylactic acid polymers and then tested thermo-mechanically. A good correlation is observed between numerical and experimental results, supporting the FEM accuracy. Results reveal that proposed boat fenders have considerable energy absorption/dissipation along with the capability to fully recover plastic deformations by simply heating up. The excellent mechanical property recovery of the proposed boat-fendering system is also shown under cycling loadings. Due to the absence of similar conceptual designs, models, and results in the specialized literature, this paper is expected to be instrumental towards 4D printing novel boat fenders with supreme energy absorption/dissipation and shape recovery properties promoting sustainability

Bio-inspired design, modeling, and 3D printing of lattice-based scale model scooter decks

This research aims at enhancing the performance of scale-model scooter decks by investigating various architected cellular metamaterial and bio-inspired core structure designs, such as honeycomb, tetrachiral, re-entrant, arrowhead, and star-shaped arrangements. An initial effort is made toward the design and rapid prototyping of small-scale deck with a uniform honeycomb core structure. More specifically, polylactic acid is utilized to fabricate complex structures via fused filament fabrication technique. Investigation is then focused on its mechanical performance, such as its bending properties obtained through a three-point bending test. Simulations are also conducted with different core configurations using a geometrically non-linear finite element method which is implemented. Experiments are carried out to verify the numerical results. After validation, various patterns are modeled, and eventually, it is observed that the functionally graded arrowhead structure has the best bending resistance, compared to other bio-inspired and mechanical metamaterial structures. At a constant force of 845 N, the functionally graded arrowhead design lowers the deflection in the middle of the scale model of scooter deck by up to 14.7%, compared to the uniform arrowhead structure. Furthermore, comparing the tetrachiral and functionally graded arrowhead configurations at a constant force, a 30% reduction in central deflection was observed. Due to the lack of similar results and designs in the specialized literature, this work could potentially advance the state-of-the-art scooter core designs and provide designers with architectures that could enhance the performance and safety of scooters