TS-DM: A Time Segmentation-Based Data Stream Learning Method for Concept Drift Adaptation.

Concept drift arises from the uncertainty of data distribution over time and is common in data stream. While numerous methods have been developed to assist machine learning models in adapting to such changeable data, the problem of improperly keeping or discarding data samples remains. This may results in the loss of valuable knowledge that could be utilized in subsequent time points, ultimately affecting the model's accuracy.

Dynamics of high-contrast grating vertical-cavity surface-emitting laser with lateral optical feedback by a heterostructure interface.

We investigate the dynamics of high-contrast grating vertical-cavity surface-emitting laser (HCG-VCSEL) with a lateral optical feedback cavity. The lateral optical feedback is realized by the reflection at the heterostructure interface between two different HCGs. The lateral optical feedback cavity possesses slow light which can be tuned by changing HCG parameters, and can control the dynamics of the HCG-VCSEL.

Evolving Gradient Boost: A Pruning Scheme Based on Loss Improvement Ratio for Learning Under Concept Drift.

In nonstationary environments, data distributions can change over time. This phenomenon is known as concept drift, and the related models need to adapt if they are to remain accurate. With gradient boosting (GB) ensemble models, selecting which weak learners to keep/prune to maintain model accuracy under concept drift is nontrivial research.

A Segment-Based Drift Adaptation Method for Data Streams.

In concept drift adaptation, we aim to design a blind or an informed strategy to update our best predictor for future data at each time point. However, existing informed drift adaptation methods need to wait for an entire batch of data to detect drift and then update the predictor (if drift is detected), which causes adaptation delay. To overcome the adaptation delay, we propose a sequentially updated statistic, called drift-gradient to quantify the increase of distributional discrepancy when every new instance arrives.

Concept Drift Detection via Equal Intensity k-Means Space Partitioning.

The data stream poses additional challenges to statistical classification tasks because distributions of the training and target samples may differ as time passes. Such a distribution change in streaming data is called concept drift. Numerous histogram-based distribution change detection methods have been proposed to detect drift.

Diverse Instance-Weighting Ensemble Based on Region Drift Disagreement for Concept Drift Adaptation.

Concept drift refers to changes in the distribution of underlying data and is an inherent property of evolving data streams. Ensemble learning, with dynamic classifiers, has proved to be an efficient method of handling concept drift. However, the best way to create and maintain ensemble diversity with evolving streams is still a challenging problem.

Genome-Wide Association Analysis Dissects the Genetic Basis of the Grain Carbon and Nitrogen Contents in Milled Rice.

Background: Carbon (C) and nitrogen (N) are two fundamental components of starch and protein, which are important determinants of grain yield and quality. The food preferences of consumers and the expected end-use of grains in different rice-growing regions require diverse varieties that differ in terms of the grain N content (GNC) and grain C content (GCC) of milled rice. Thus, it is important that quantitative trait loci (QTLs)/genes with large effects on the variation of GNC and GCC are identified in breeding programs.

Single-mode semiconductor lasers fabricated by standard photolithography for direct modulation.

The output characteristics, modal properties, far-field profiles, and dynamic modulation responses of semiconductor lasers with surface higher-order gratings fabricated by the standard photolithography are presented. Single-mode semiconductor lasers with 20- and 37-order gratings for the 1.55 µm wavelength range are realized.

Eight-channel laser array with 100 GHz channel spacing based on surface-slotted structures fabricated by standard lithography.

An eight-channel laser array with 100 GHz channel spacing based on surface-slotted structures is demonstrated. Wavelength selection is realized by using a group of micrometer-order slots fabricated by standard lithography technology. An output power of over 14 mW and a side-mode suppression ratio of better than 35 dB for each laser within the array are achieved.

Two dimensional analysis of finite size high-contrast gratings for applications in VCSELs.

2-dimensional simulations of high-contrast gratings (HCGs) of finite size are carried out, targeting at their applications in vertical-cavity surface-emitting lasers (VCSELs). Finite HCGs show a very different behavior from infinite grating ones. The reflectivity of a finite HCG strongly depends on the HCG size and the source size.

Polarization-insensitive subwavelength grating reflector based on a semiconductor-insulator-metal structure.

We present a polarization-insensitive subwavelength grating reflector based on a semiconductor-insulator-metal structure. The polarization-insensitive characteristic originates from the combined effect of the TM-polarized high-reflectivity high-index-contrast subwavelength grating and the TE-polarized metallic (Au) subwavelength grating with the addition of the insulator layer. The overlapped high reflectivity (>99.

Ultracompact 1×4 TM-polarized beam splitter based on photonic crystal surface mode.

We provide an improved surface-mode photonic crystal (PhC) T-junction waveguide, combine it with an improved PhC bandgap T-junction waveguide, and then provide an ultracompact 1×4 TM-polarized beam splitter. The energy is split equally into the four output waveguides. The maximal transmission ratio of each output waveguide branch equals 24.

Lateral cavity photonic crystal surface-emitting laser with ultralow threshold.

A lateral cavity photonic crystal (PhC) surface-emitting laser is realized on a commercial epitaxial waveguide wafer without a distributed Bragg reflector first. Energy is coupled from the lateral resonance to surface-emitting light through the Γ band edge of the PhC with a square lattice. Electrically driven 1553.

Improved fake mode free plane wave expansion method.

We analyze the origin of the fake modes introduced by the plane wave expansion method with three-dimension (3D) supercell approximation. Through the detailed analysis of the energy distribution of fake modes and real modes, we propose the plane wave expansion-three planar-slab waveguides method to remove the fake modes and obtain the fake mode free band structure of a two-dimensional air hole photonic crystal slab. To the best of our knowledge, this is the first time that such a fake mode free photonic crystal band structure is presented.

Optical properties of the crescent and coherent applications.

By out-of-particle surface plasmon (SP) excitation in the near infrared range, the influences of key parameters on the basic optical properties of the Au crescent are qualitatively studied from the mode dispersion. Based on the coherent control of SP wave, a crescent pair sensor with the intensified extracted signal and the controllability of sensing is proposed. In addition, the crescent half replaced by Ag functioning as a position detector is also proposed.