Miracle-dz/UniFAR-FTUs huggingface dataset:
Proactive Retention Management in Retail: Field Experiment Evidence for Lasting Effects

The vast amount of data that is now available allows retailers to make marketing decisions at the customer level and thus to manage customer defection proactively. Although there is an extensive literature that focuses on developing models to predict customer "churn'' in contractual settings, few studies have addressed managing customer defection in the noncontractual context. Using data supplied by a large German grocery retailer, we address this gap in the literature for noncontractual settings as follows. First, we develop a definition of churn that distinguishes between random short-term volatility and true defection. Second, we compare various prediction algorithms in terms of their ability to predict customer churn from data available to the retailer; this analysis enables us to devise an approach for identifying the customers most likely to defect and for targeting them proactively. Third, our approach is tested in a large-scale field experiment involving 400,000 customers for whom we estimate defection probabilities. In particular, potential churners are targeted with a series of marketing campaigns over six months. We find that weekly revenue from this treatment group increases by 3% and that, in comparison with the control group, the number of churners declines by 6%. Lastly, we show that the effects of proactive churn management last for at least two months after the end of the field experiment.
Tracheostomy in south western Nigeria: Any change in pattern?

With the decrease of life-threatening obstructive upper airway infections and the ongoing improvement of intensive care medicine, the role of tracheostomy has been changing. This study aims to investigate whether the indications and outcome for tracheostomy in this unit have changed over recent years. A retrospective chart review of 64 patients who had tracheostomy in our ENT facility between January 2002 and December 2008 was done. The age range was 2 months to 96 years with a male to female ratio of 2.8:1. The peak age incidence was in the age-group 0-10 (23.4%). Forty tracheostomies (62.5%) were performed as emergency while 24 (37.5%) as elective procedures. Transverse skin incision was employed in all the cases. Post operative complications rate was 10.9%. Upper airway obstruction still remains the most common indication for tracheostomy in our centre. Laryngeal carcinoma is the main indication for tracheostomy while conditions such as infections, which were one of the leading indications a decade ago, have diminished. Other indications included trauma, prolonged intubation, and adjunct to surgery. There was no tracheostomy related mortality.
IIT-BHU at CIQ 2019: Classification of Insincere Questions

This paper presents details of the work done by the team of IIT (BHU) Varanasi for the “Classification of Insincere Questions” track organized in the FIRE 2019. We implement bidirectional long short term memory using pre trained GloVe word embedding. Further, we analysed the results with different other embeddings.
Minimum-Impact First: Scheduling Virtual Machines Under Maintenance Scenarios

Virtual Machine (VM) migration is an important feature for ensuring smooth operations during maintenance and disaster recovery scenarios. The migration might be inter-site and in such a case the inter-site bandwidth which is typically Wide Area Network (WAN) might be a bottleneck. In such a case, the bandwidth is affected by the amount of inter-VM traffic that becomes separated during the migration process. The amount of separated traffic might not only cause degradation of the of the Quality of Service (QoS) of inter-communicating VMs but can also delay the migration process due to the congestion of the migration link. The state-of-the-art algorithm due to Yazidi et al. is an affinity aware algorithm that does not consider the completion time of the migration. The first stage of our algorithm is identical to Yazidi et al. where we resort to graph partitioning theory in order to partition the VMs into groups with high intra-group communication. In the second stage, we devise a greedy algorithm for controlling the order of the migration groups by considering their inter-group traffic that greedily selects groups with the lowest impact in terms of volume of separated traffic which we denominate Minimum-Impact First (MIF). We also design a latency-aware algorithm that only schedules the quickest migration first. The latter simple heuristic interestingly outperforms legacy works in the case of migration over a non-dedicated link. We find that our MIF algorithm consistently outperforms the state-of-the-art algorithms by a clear margin using real-traffic traces by a margin larger than 40%. We show that the MIF algorithm ensures the lowest amount of separated traffic in both dedicated-link and non-dedicated-link scenarios.
Ontology-based Learning Analytics in Medicine

Through SIDES 3.0, we are developing an ontology-based e-learning platform in medicine to make learning analytics transparent and explainable to end-users (learners and teachers). In this project, the educational content, the traces of students' activities and the correction of exams are linked and related to items of an official reference program in a unified data model. As a result, an integrated access to useful information is provided for student progress monitoring and equipped with a powerful query language allowing users to express their specific needs relating to data exploration and analysis.
Effective Processing of Specularite Ore by Wet Magnetic Separation and Reverse Flotation Techniques

T he aim of this study was to obtain a high grade and yield percentage of iron concentrate from a specularite ore by using wet magnetic separation and reverse flotation techniques. The processing a specularite sample using wet magnetic separation and reverse flotation method was studied. During the magnetic separation process, particle size was -2000 µm and magnetic field applied at 0.25 T and 0.85 T which were performed at a solid-liquid ratio of 10% and 20% by weight, respectively. In the reverse flotation tests, experimental design (DOE) was applied, statistically. Depressant dosage, collector dosage and flotation time were selected as main parameters. PH value, frother dosage (MIBC) and particle size were constant parameters. The results showed that particle size and magnetic field intensity had a significant effect on the iron concentrate grade and yield for wet magnetic separation. The optimum value of iron concentrate grade was 98.75% at 0.25 T and particle size of -150 µm while the highest value of iron concentrate yield was 67% at 0.75 T and particle size of -74 µm. In the flotation tests, depressant dosage had the greatest influence on the iron concentrate grade while the effect of the collector dosage and froth collection time were less. Froth collection time had the greatest effect on iron concentrate yield.The maximum iron concentrate grade was 90.13% for the following conditions: 5250 g/ton depressant, 1000 g/ton collector and 2-minute froth collection time. The maximum iron concentrate yield was 98.96% for the following conditions: 5250 g/ton depressant, 1500 g/ton collector and 1 min froth collection time under fixed conditions.
MBE-grown ZnO-based nanostructures for electronics applications

Low-dimensional semiconductors have properties di erent from their bulk counterparts and are thus attractive components for future electronic devices. This thesis presents work on ZnO nanostructures and ZnO/ZnMgO nano-heterostructures grown by molecular beam epitaxy (MBE) for electronics applications. ZnO nanostructures are grown by gold-catalysed MBE. We show that the cut of sapphire used as a substrate determines the orientation of one-dimensional nanostructure growth. On C-plane sapphire we grow ZnO nanowires and on R-plane sapphire we grow ZnO nanobelts. The morphology of nanobelts is shown to depend on temperature with tapering reduced at higher temperatures. Field-e ect transistors based on ZnO nanobelts are fabricated to characterize the electronic properties of single nanobelts. ZnO/ZnMgO heterostructure nanowires and nanobelts are grown and characterized. We show abrupt ZnO/ZnMgO interfaces and demonstrate that the core-shell structures in nanowires increase the luminescence intensity of nanowires. Nanobelt heterostructures are characterized optically at both room temperature and cryogenic temperatures showing evidence of quantum con nement in these structures. Scanning transmission electron microscope cathodoluminescence (CL) is performed on single ZnO nanowires. We perform hyperspectral mapping of CL, in which a single nanowire is spatially mapped with full CL spectra collected at each spatial co-ordinate on the nanowire. We achieve record resolution for hyperspectral mapping and deconvolve full spectra into constituent components. This allows us to distinguish surface and defect peaks as well as CL from inter-band processes in ZnO. We perform proof-of-principle studies combining high quality RF superconducting circuits with epitaxial ZnO layers on single sapphire substrates. Such chips can be used for future experiments coupling mechanical degrees of freedom to superconducting qubits for quantum opto-mechanical experiments.
Comparative Study on the Photovoltaic Properties of Dye-Sensitized Solar Cells (DSCs) Based on Different Counter Electrode Configurations

Previously, we reported an investigation on Delonix regia dye extract as a natural sensitizer for TiO2/DSC assembled with platinum counter electrode and low power conversion efficiency was recorded. This necessitated the current investigation on Delonix regia dye extract as a natural sensitizer for TiO2/DSCs assembled with different counter electrodes. Platinum counter electrode was used for one of the DSCs while polyaniline (PANI) was used to replace platinum in the other DSC. The vitriol treated PANI thin film consisted of aniline mixed with potassium dichromate directly reacted on circular graphite foam. The conductivity and Hall coefficient were measured to be 1 1 1 10 894 . 4      cm and 1 3 1 10 061 . 2   C cm respectively using ECOPIA Hall Effect Measurement System (HMS-3000 Version 3.52). Sequel to this, the DSCs were assembled and characterized using a standard overhead Veeco viewpoint solar simulator equipped with AM 1.5 filter to give a Original Research Article Ahmed et al; JMSRR, 3(2): 1-9, 2019; Article no.JMSRR. 47570 2 solar radiation of 1000 W/m and coupled to a Keithley source meter (model 4200SCS) which was connected to the computer via GPIB interface for data acquisition. The overall solar power conversion efficiencies of 0.02% and 0.04% were obtained for TiO2-DSC//Delonix regia dye//platinum electrode and TiO2-DSC//Delonix regia dye//PANI electrode respectively. Delonix regia dye extract proved to be rather a poor sensitizer as can be seen by the low spectral absorption at lower energies with short circuit current density of 0.10mAcm -2 and 0.11mAcm -2 respectively. Nevertheless, a 10% decrease in the electron recombination via redox electrolyte and collection at the photoelectrode was observed for TiO2-DSC//Delonix regia dye//PANI electrode and a 20% increase in the open circuit voltage (Voc) was also observed. Finally, about 37% increase in the fill factor was observed for the TiO2-DSC//Delonix regia dye//PANI electrode over TiO2-DSC//Delonix regia dye//platinum electrode. This necessitated approximately 50% increase in the power conversion efficiency for the TiO2-DSC//Delonix regia dye//PANI electrode over TiO2DSC//Delonix regia dye//platinum electrode.
"Comanagement of Phlegm and Stasis" on the Apoptosis of Marrow Karyocyte in Mice with Aplastic Anemia and its Possible Mechanism

Objective: To explore the "Comanagement of Phlegm and Stasis" on the apoptosis of marrow karyocyte treated with aplastic anemia serum and its possible mechanism.Methods: Immune-mediated model of aplastic anemia(AA) mice was copied,and their serum was used to induce the apoptosis process of marrow karyocyte from normal mice.After co-culture with serum from rat administrated with Traditional Chinese Medicine(Prescription on reinforcing kidney purely or both on reinforcing kidney and dispel phlegm and blood stasis) for 24 hours,the apoptosis rate,enzymic activity of caspase-3 and the expression of Bax protein of karyocyte were detected.Results: The apoptosis rate of marrow karyocyte is significantly higher in AA mice serum treated group than that not(P0.01),both the treated group can relieve the apoptosis inducing effect of AA mice serum(P0.01),inhibit the enzymic activity of Caspase-3(P0.05),and in which,the group treated both on "reinforcing kidney and dispel phlegm and blood stasis" is more obviously(P0.05). The multiply of positive staining intensity and rate of Bax protein is down-regulated in both treated groups(P0.05),while no significance was observed.Conclusion: The apoptosis process can be induced by serum from AA mice,and can be inhibited by both two prescriptions through the caspase-3/Bax pathway.This phenomenon is more noted in group treated "both on reinforcing kidney and dispel phlegm and blood stasis",and had no relationship to Bax protein expression.
Qualitative phenomenological investigation of the transient temperature gradient during gas turbine's hot section component cooling

In this study, the temporal variation of temperature gradient in the gas turbine hot section components in the transient process is raised, and according to its impact on life expectancy computations, the accuracy of the usual methods is investigated qualitatively. It is worth noting that in such two-phase problems, existing different time-scales prevent some common simplifications that are usually used for unsteady investigations like a quasi-steady assumption, and so there is no choice but to conduct coupled transient studies despite their high time-consuming manner. Hence, the phenomenological and qualitative model is introduced to analyze the cooling problem and show the transient behavior. The results show that during unsteady operations, if the time rate of changes is high, some considerable overshoots (more than 30%) of temperature gradients in hot sections may be ignored in common quasi-steady predictions, which must be predicted only by using the unsteady and coupled simulations.
Dissimilar Infrared Brazing of CoCrFe(Mn)Ni Equiatomic High Entropy Alloys and 316 Stainless Steel

Dissimilar infrared brazing of CoCrFeMnNi/CoCrFeNi equiatomic high entropy alloys and 316 stainless steel using MBF601 and BNi-2 foils was evaluated. The wetting angles of the two fillers at 50 °C above their liquidus temperatures on the three substrates were below 40 degrees. The CoCrFeMnNi/316 SS joint had the highest shear strength of 361 MPa with BNi-2 filler brazing at 1020 °C for 180 s, and fractured at the CrB compound in the joint. The CoCrFeMnNi/MBF601/316 SS joint contained a CoCrFeMnNi-based matrix, phosphides and B-containing compounds. The CoCrFeNi/316 SS joint had the highest shear strength of 374 MPa when brazed with BNi-2 filler at 1020 °C for 600 s, and fractured at the CrB in the joint. The CoCrFeNi/MBF601/316 SS joint consisted of a (Fe,Ni)-rich matrix, phosphides and B/Cr/Fe/P compounds, and the highest shear strength of 324 MPa was achieved when it was brazed at 1080 °C for 600 s.
23.3: Invited Paper: Hybrid III‐Nitride/Nanocrystals White Light‐Emitting Diodes

An excellent hybrid III‐nitride/nanocrystal nanohole light‐emitting diode (h‐LED) has been developed utilizing förster nonradiative resonant energy transfer (NRET) between violet/blue emitting InGaN/GaN multiple quantum wells (MQWs) and various wavelength emitting nanocrystals (NCs) as color conversion mediums. InGaN/GaN MQWs are fabricated into nanoholes by soft nanoimprint lithography to minimize the separation between MQWs and NCs. A significant reduction in the decay lifetime of excitons in the MQWs of the hybrid structure has been observed as a result of the NRET from the nitride emitter to NCs. The NRET efficiency of the hybrid structures is obtained from the decay curves, as high as 80%. Based on a systemic optimization for white emission indexes, a series of hybrid ternary complementary color h‐LEDs have been demonstrated with a high color rendering index, up to 82, covering the white light emission at different correlated color temperatures ranging from 2629 to 6636 K, corresponding to warm white, natural white, and cold white. The efficiency droop of hybrid LEDs was validly suppressed, which mainly resulted from the extraction of excess carrier concentrations in InGaN/GaN MQWs via the rapid non‐radiative resonant energy transfer process under the higher injection condition, revealing a great potential to realize efficient white light emitters in the future.
Design optimization for a three-layers shrink-fitted pressure vessel exposed to very high pressure

In this paper, design optimization for a different materials three layers shrink-fitted cylinder subjected to very high pressure has been investigated. The optimum design of the cylinder has been brought into being by upsurge the advantageous compressive residual stresses, thus increasing the carrying load capacity of the cylinder as well as its fatigue life. A finite element model has been established to estimate the residual hoop stress, the equivalent von-Misses stress and the equivalent plastic strain. In this optimization problem, the design parameters have been taken as the thicknesses of the layers and the diametral interference between them. Also, the major constraint is that the equivalent von-misses stress for each layer does not exceed the yield strength of each layer material during the shrink-fitting process and when subjected to 750 MPa inner working pressure. Design of Experiment (DOE) and the Response Surface Method (RSM) have been joined together to obtain an effective objective function to be used in the optimization formulation. Two optimization techniques have been sequentially used to obtain accurate global optimum parameters, Multi Objective Genetic Algorithm (MOGA) and Lagrange’s Multiplier (LM). The hoop and von-Mises stresses distributions along the thickness as well as the mechanical fatigue life have been calculated for the cylinder before and after optimization. It was found that the residual hoop stress has been enhanced at the near bore area by 31 %, also the fatigue life for the cylinder is better than that before optimization by 10900 cycles.
Hybrid Structural Composites with Energy Harvesting Capabilities

Hybrid materials have received significant interest due to the potential enhancements they provide over traditional materials such as sensing, actuating, energy scavenging, thermal management, and vibration damping. While traditional materials can be utilized for either one of these functions or loadbearing, the hybrid materials are superior as they allow combination of a wide array of functionalities whilst being suitable for loadbearing purposes. The goal of this thesis is to elucidate the synergistic effects of hybridization of two piezoelectric materials; zinc oxide nanowires (ZnO NWs) and thin film of lead zirconium titanate (PZT) on the mechanical and energy harvesting of beams made from plain-woven carbon fiber reinforced epoxy composites (CFRPs). ZnO NWs have, by contrast, displayed great promises. While not only being a very strong piezoelectric material, it enhanced the mechanical and dynamic properties of the composite due to the increased surface area and mechanical interlocking. However, the aspect of energy scavenging is somewhat limited due to the weak piezoelectrical effects of ZnO nanowires. In this thesis, the prospects of ZnO NWs are exploited further to improve both their production processes and piezoelectric performance. Combining ZnO NWs grown on carbon fibers combined with other piezoelectrical materials has not yet been implemented but appears to be encouraging. This is the focus of this thesis. Despite that the composite comprising the combination of the two piezoelectric materials showed a minor drop in tensile strength and damping characteristics, the substantial gain in both stiffness (25.8 % increase compared to plain composite) and the electrical power gain (733.94 % more than that for ZnO NWs) is very promising for future application of the hybrid material into
Generation of 40 W, 400 fs pulses at 1 MHz repetition rate from efficient, room temperature Yb:YAG double-pass amplifier seeded by fiber CPA system

In this work we presented a compact femtosecond high average power (35 W), high energy (35 uJ) and high pulse repetition rate (1 MHz) laser system based on efficient room-temperature Yb:YAG crystal rod double-pass power amplifier and Yb doped fiber seed laser. High fidelity nearly transform-limited pulses (330 fs) were obtained by using matched dispersion pair of chirped fiber Bragg grating (CFBG) as a pulse stretcher and 4-pass diffraction grating based pulse compressor. Residual dispersion mismatch was compensated by applying linear thermal gradient along CFBG. Presented laser system is a compact and convenient solution for various industrial and scientific applications.
Fatigue Strength Simulation of Natural Porous Structure

Japan, which is the poor country in natural resources, is required to use renewable energy. The rice is a staple food and the amount of its production is about 9 million tons per year in Japan [1]. Rice hull is a non-edible part and has produced 1.9 million tons per year [2]. Among them, about 1.2 million tons have been utilized as fertilizer and soil conditioner. However, about 700 thousand tons are disposed of as agricultural waste. The rice hull silica carbon material (RHSC) is developed in order to utilize the rice hull to protect the global environment and promote recycling. The various basic physical properties have already been evaluated for the RHSC by this research group [3]. The RHSC is a porous carbon material utilizing natural porous structure originated from the rice hull. The RHSC is manufactured by impregnating a phenol resin with rice hull, and carbonizing it in a nitrogen gas atmosphere [4, 5]. The raw rice hull contains about 20 mass% of inorganic constituent and 80 mass% of the organic constituent. Among them, about 95 mass% of the inorganic constituent is silica. Therefore, the RHSC is material with high water resistant [6] and seawater resistant [7, 8]. Moreover, the RHSC, which has excellent low friction and abrasion resistant under unlubricated conditions [6], is expected to be used as sliding materials such as the linear slide rail in future. Generally, structures and machine elements are subjected to cyclic loads. Since fatigue failure caused by cyclic load often brings disaster, evaluation of fatigue strength is important. However, obtaining the strength experimentally is required several weeks. Therefore, simulation method of fatigue strength is useful for machine designer. Murakami has derived [9] a fatigue strength evaluation formula for metallic materials which is based on material hardness and defect size. The fatigue strength simulation method for steel gears adopting Murakami’s formula was proposed by one of the authors [10]. The dispersion of fatigue strength is also estimated by the simulation method. There is a similarity between the RHSC and metallic materials in the viewpoint of defect including materials. In this study, fatigue strength simulation for the RHSC test piece was carried out.