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The High Average Utility Itemset Mining (HAUIM) technique, a variation of High Utility Itemset Mining (HUIM), uses the average utility of the itemsets. Historically, most HAUIM algorithms were designed for static databases. However, practical applications like market basket analysis and business decision-making necessitate regular updates of the database with new transactions. As a result, researchers have developed incremental HAUIM (iHAUIM) algorithms to identify HAUIs in a dynamically updated database. Contrary to conventional methods that begin from scratch, the iHAUIM algorithm facilitates incremental changes and outputs, thereby reducing the cost of discovery. This paper provides a comprehensive review of the state-of-the-art iHAUIM algorithms, analyzing their unique characteristics and advantages. First, we explain the concept of iHAUIM, providing formulas and real-world examples for a more in-depth understanding. Subsequently, we categorize and discuss the key technologies used by varying types of iHAUIM algorithms, encompassing Apriori-based, Tree-based, and Utility-list-based techniques. Moreover, we conduct a critical analysis of each mining method's advantages and disadvantages. In conclusion, we explore potential future directions, research opportunities, and various extensions of the iHAUIM algorithm. [ABSTRACT FROM AUTHOR]

The detection of different types of concept drift has wide applications in the fields of cloud computing and security information detection. Concept drift detection can indeed assist in promptly identifying instances where model performance deteriorates or when there are changes in data distribution. This paper focuses on the problem of concept drift detection in order to conduct frequent pattern mining. To address the limitation of fixed sliding windows in adapting to evolving data streams, we propose a variable sliding window frequent pattern mining algorithm, which dynamically adjusts the window size to adapt to new concept drifts and detect them in a timely manner. Furthermore, considering the challenge of existing concept drift detection algorithms that struggle to adapt to different types of drifting data simultaneously, we introduce an additional dual-layer embedded variable sliding window. This approach helps differentiate types of concept drift and incorporates a decay model for drift adaptation. The proposed algorithm can effectively detect different types of concept drift in data streams, perform targeted drift adaptation, and exhibit efficiency in terms of time complexity and memory consumption. Additionally, the algorithm maintains stable performance, avoiding abrupt changes due to window size variations and ensuring overall robustness. [ABSTRACT FROM AUTHOR]

With the rapid development of AI and big data mining technologies, computerized medical decision-making has become increasingly prominent. The aim of high-utility pattern mining (HUPM) is to discover meaningful patterns in medical databases that contribute to maximizing the utility from the perspective of diagnosis. However, HUPM pays less attention to the interpretability and explainability of these patterns in medical decision-making scenarios. This paper proposes a novel algorithm called the Improved fuzzy high-utility pattern mining (IF-HUPM) to address this problem. First, the paper applies a fuzzy preprocessing method to divide the fuzzy intervals of a medical quantitative data set, which enhances the fuzziness and interpretability of the data. Next, in the process of IF-HUPM, both fuzzy tree and list structures are employed to calculate fuzzy high-utility values. By combining the characteristics of the one-stage and two-stage algorithms of HUPM, an adaptive-phase Fuzzy HUPM hybrid frame is proposed. The experimental results demonstrate that the proposed IF-HUPM algorithm enhances both accuracy and efficiency and the mining process requires less time and space on average. [ABSTRACT FROM AUTHOR]

GeTe is an important narrow bandgap semiconductor material and has found application in the fields of phase change storage as well as spintronics devices. However, it has not been studied for application in the field of infrared photovoltaic detectors working at room temperature. Herein, GeTe nanofilms were grown by magnetron sputtering technique and characterized to investigate its physical, electrical, and optical properties. A high-performance infrared photovoltaic detector based on GeTe/Si heterojunction with the detectivity of 8 × 1011 Jones at 850 nm light irradiation at room temperature was demonstrated. [ABSTRACT FROM AUTHOR]

One option for low-cost white light-emitting diodes (LEDs) is the combination of a near-ultraviolet (UV) LED chip (382 nm) and a single phosphor. Such MnY(MoO) single phosphors have been fabricated by a simple solid-state reaction route and their emission color tuned by controlling the Mn doping amount. The chromaticity coordinates of the white light emitted by the UV GaN LED with the MnY(MoO) phosphor were x = 0.5204 and y = 0.4050 [correlated color temperature (CCT) = 7958 K]. [ABSTRACT FROM AUTHOR]

A novel inverted telephoto four mirror zoom system with large field of view (FOV) was designed over a wide spectral bandwidth. The initial configuration of the zoom system was obtained by applying the aberration equations under certain constraints. Then, a method was presented to correlate the aspheric coefficients with the aberrations of this system. By using this method, the required image quality could be achieved after optimization using the ZEMAX® Optical Design Code. Besides good image quality, another benefits of using this system is the potential for using cheap optics. [ABSTRACT FROM AUTHOR]

By expanding the absorption into infrared region, we have successfully demonstrated an enhanced efficiency of polymer solar cells by incorporating lead selenide (PbSe) colloidal quantum dots into copolymers of [poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C-butyric acid methyl ester (PCBM)] as active layer. The influence of inorganic ligands and the post-annealing conditions on device performance has been investigated in detail. After optimization of these parameters, a maximum power conversion efficiency of 3.31 % is obtained from solar cell indium tin oxide (ITO)/poly(3,4-ethylendioxy thiophene):poly(styrenesulfonate) (PEDOT:PSS)/P3HT:PCBM:PbSe/Al under AM 1.5 and it has been improved by 14.5 % as compared with the control device ITO/PEDOT:PSS/P3HT:PCBM/Al. [ABSTRACT FROM AUTHOR]

In this paper, we presented a solution-processed photodetector with a configuration of field-effect transistor Au/poly(3-hexylthiophene) (P3HT)/poly(methyl methacrylate) (PMMA)/Al, in which P3HT acts as the active layer and PMMA as dielectric layer, and the drain and source electrodes (Au) were fabricated through a shadow mask. Using the top-gate bottom-contact configuration and employing orthogonal solvent to avoid 'solution corrosion', the devices with three different thicknesses (38, 150 and 223 nm) of the P3HT layer were investigated, and all of them showed typical transistor properties and their drain-source current can be controlled by the gate voltage. The photocurrent of the device Au/P3HT(223 nm)/PMMA(930 nm)/Al shows an obvious increment over a broad range of wavelengths from 350 to 650 nm, giving a maximum photo-to-dark current ratio of 2,404 with a photoresponsivity of 22.71 mA/W under the incident 350 nm light at V = −5 V. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrated an enhanced performance of polymer solar cells by incorporating functionalized single-walled carbon nanotubes (SWCNTs) decorated with CdSe/ZnS core-shell colloidal quantum dots (CQDs) into copolymers of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as active layer. Short-circuit current density and power conversion efficiency of the ITO/PEDOT:PSS/P3HT:PCBM:(CdSe/ZnS-SWCNTs)/Al solar cells can be enhanced by more than 31 and 23 %, respectively, as compared with the control device ITO/PEDOT:PSS/P3HT:PCBM/Al. This enhancement is due to the high electron-transporting ability of SWCNTs and the increased absorption of CdSe/ZnS CQD in visible region. It shows an applicable way to improve the efficiency of polymer solar cells by incorporating suitable quantity of CQDs-decorated SWCNTs with suitable kinds of CQDs and suitable acid treatment to the SWCNTs. [ABSTRACT FROM AUTHOR]

Two types of organic light-emitting diodes with structures of ITO/ N, N′-bis(1-naphthyl)- N, N′-diphenyl,1,1′-biphenyl-4,4′-diamine (NPB)/tris(8-hydroquinolinato)aluminum(Alq)/2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline(BCP)/Alq:4-dicyanome-thylene-2-(tert-butyl)-6-methyl-4H-pyran(DCJTB)/Alq/Al and ITO/NPB/BCP/Alq/Alq:DCJTB/Alq/Al were studied. NPB was chosen as a hole-transporting/blue-emitting layer. Alq adjacent to BCP acted as a green emitting layer while that adjacent to the Al cathode acted as an electron-transporting layer. Alq doped with 2 wt.% DCJTB was used as a red emitting layer. The operating principles of the devices were explained by the mechanism of Förster energy transfer and the hole and exciton blocking effect of BCP. It was found that the spectral characteristics of the devices strongly depended on the relative location between the green emitting Alq layer and the BCP layer, as well as their thickness. Pure white emission with the CIE coordinates of (0.33, 0.33) was achieved by mixing the three primary colors in the device with the structure of ITO/NPB(30 nm)/ BCP(6 nm)/Alq(30 nm)/Alq:DCJTB(30 nm)/Alq(30 nm)/Al. The BCP layer played an important role in distributing the exciton energy among the three emitting layers to achieve a balanced white light. The white emission of this device was largely insensitive to the driving voltage (15-27 V) with the insertion of the green emitting Alq layer. [ABSTRACT FROM AUTHOR]

By considering the interaction between Fowler-Nordheim tunneling injection theory and charge carriers transporting through the bulk, an electroluminescence model for organic single-layer diodes is presented. The expressions of the recombination current density, recombination efficiency and conductivity of the diodes are provided, which elucidate the controlling role of the electric field on mobility and recombination zone. The equilibrium of two opposite charge carriers injection and the central position of recombination zone are two important preconditions for reducing the leakage current. Space-charge-limited current occurs only over a certain high bias, meanwhile, the quantity of injection carriers increases over the transport capacity of the bulk. [ABSTRACT FROM AUTHOR]

Presents a study on the electroluminescence of bilayer devices and the influence of the organic layers' thickness on the characteristics of the device. Details on the sample preparation; Experimental results and discussion; Conclusion.