Enhanced photonic time-stretch reservoir computing using all-optical input masks

Input masks are essential in reservoir computing to enhance performance. Here we report a novel all-optical masking scheme for photonics time-stretch reservoir computing based on optical spectral filtering. This approach overcomes the electronic bottleneck in digital temporal masking and offers better performance in classification tasks

Experimental Implementation of An All-Optical Reservoir Computer Using Photonic Time Stretch and Spectral Mixing

Reservoir computing (RC) has been widely used in processing temporal information and classification tasks due to its high efficiency in training and testing. In this paper, we have experimentally demonstrated the performance of an all-optical reservoir computer based on time stretch and spectral mixing. Spectral comb lines of the stretched optical pulse are chosen as virtual nodes in the reservoir layer. Nonlinear spectral mixing is achieved through phase modulation and semiconductor optical amplification. A simple temporal waveform classification task was implemented using the demonstrated RC system to verify the approach

Ultrafast Beam Steering User Localization in Optical Wireless Communication

An ultrafast user localization scheme in beam steering optical wireless communication based on real-time Fourier Transform is demonstrated. All-optical dispersive operation enables ultrafast and real-time user-specific wavelength identification overcoming bottleneck in digital signal processing

Multiple Realization Pathways of County-level Medical Alliances to Improve Service Capacity: a Fuzzy Set Qualitative Comparative Analysis

Background The long-standing dilemma of difficulties in the improvement of primary care in China has led to county-level medical alliances reforms in various regions throughout the country. Objective To analyze the combination of pathways that contribute to improving the service capabilities of county-level medical alliances, providing a reference for the improvement and promotion of county-level medical alliances. Methods CNKI and Wanfang Data Knowledge Service Platform were searched by using "county-level medical alliance" "county health care unit" as keywords from 2020-01-01 to 2022-11-26 to obtain 662 related papers, a total of 9 papers and 11 cases were selected in the analysis. Based on literature review and policy analysis, variables including scale of planning and implementation, close organizational structure, collaborative management system, information platform integration, regional resources sharing, medical insurance payment reform, and incentive mechanism design were identified as outcome variables, while the fuzzy set qualitative comparative analysis was used to identify multiple realization pathways for the service capability improvement of county-level medical alliances. Results Four combinations of pathways were found to improve the service capability of county-level medical alliances. Pathway S1: planning and implementation scale * close organizational structure * collaborative management system * regional resources sharing * medical insurance payment reform * incentive mechanism design. Pathway S2: close organizational structure * collaborative management system * information platform integration * regional resources sharing * medical insurance payment reform * incentive mechanism design. Pathway S3: smaller scale of planning and implementation * close organizational structure * collaborative management system * non-integrated information platform * non-sharing of regional resources * medical insurance payment reform * incentive mechanism design. Pathway S4: smaller scale of planning and implementation * close organizational structure * collaborative management system * non-integrated information platform * regional resource sharing * medical insurance payment reform * no incentive mechanism design. Conclusion The improvement of service capability of county-level medical alliances needs to focus on close organizational structure, establish management system focusing on the collaboration of departments and member institutions, and promote medical insurance payment reform such as total budget management system of medical insurance funds and diagnosis related groups (DRGs)

Experimental Investigation of Time-Stretch-Based Reservoir Computing with an Optical Input Mask

In this paper, we experimentally demonstrated a novel all-optical reservoir computer with an all optical input mask. The combination of the binary random masks and the time-stretched ultrashort pulses has increased the system’s classification performance. Compared with the traditional digital masks, this method shows superior classification performance in spoken-digit classification tasks and eliminates the need for high-speed modulation for digital masks

Enhanced thermal stability and hardness of Zr46Cu39.2Ag7.8Al7 bulk metallic glass with Fe addition

We studied the effects of Fe addition on the thermal stability and hardness of (Zr46Cu39.2Ag7.8Al7)100−yFey (y = 0–7) bulk metallic glasses (BMGs). Both the supercooled liquid region (ΔTx) width and crystallization temperature of the (Zr46Cu39.2Ag7.8Al7)100−yFey BMGs increase with Fe addition; and the largest ΔTx of 114 K is achieved at y = 4. The average free volume decreases with increasing Fe content. The hardness increases with increasing Fe content, which may result from the decrease in free volume and the precipitation of nanocrystalline phases from glassy matrix due to Fe addition

Reservoir Computing Assisted Ultrafast User Localization in Beam Steering Optical Wireless System

A novel approach to achieving ultrafast real-time user localization in optically controlled beam-steering wireless communications (OWC) is proposed and demonstrated in this letter. Ultrafast wavelength encoded user localization at 50 MHz rate is achieved based on photonic time stretch concept and a passive beam scanner using a 45° tilted fibre grating (TFG). Not only the angular separation but also the linear distance from the access point can be determined simultaneously. More importantly, challenging instantaneous optical wavelength identification within nanosecond range is successfully achieved through chirped microwave frequency encoding and reservoir computing (RC) based frequency identification. A proof-of-concept experiment was carried out to verify the proposed approach. The results show that RC is more efficient in frequency chirp identification than the conventional short-time Fourier transform approach