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In this letter, an efficient model-driven deep learning (DL) based massive multiple-input multiple-output (MIMO) detector is proposed by improving the approximate expectation propagation (EPA) algorithm, named EPANet. Specifically, EPANet is constructed by unfolding the iterative EPA detector and adding learnable parameters to enhance the performance and convergence robustness through the DL approach. Only one training procedure is required in advance for EPANet to be reused for multiple detection tasks with different antenna configurations. Numerical results indicate that DL can bring significant performance improvement to EPA with various antenna settings. Besides, the proposed EPANet can outperform state-of-the-art (SOA) DL-based detectors with hardware-friendly complexity, especially under highly-correlated channels.

Quadriplegia is an extremely serious disease. Due to the impaired function of patients' limbs, it is difficult for them to move freely by a wheelchair. This dilemma has become a huge obstacle to the rehabilitation of the disabled, and meanwhile added extra burden to society. To improve the quality of their lives, our team designs a vision-controlled automatic wheelchair based on the pupil center and cornea reflection (PCCR) technique. By constructing a multi-sensor real-time intelligent control system, the wheelchair realizes eye-controlled movements and other auxiliary functions such as emergency communication and rollover alarm. Through continuous optimization of multiple versions, a more intelligent, highly reliable, and low-cost wheelchair is manufactured.

Network-assisted full-duplex (NAFD) distributed massive multiple input multiple output (M-MIMO) enables the in-band full-duplex with existing half-duplex devices at the network level, which exceptionally improves spectral efficiency. This paper analyzes the impact of low-resolution analog-to-digital converters (ADCs) on NAFD distributed M-MIMO and designs an efficient bit allocation algorithm for low-resolution ADCs. The beamforming training mechanism relieves the heavy pilot overhead for channel estimation, which remarkably enhances system performance by guiding the interference cancellation and coherence detection. Furthermore, closed-form expressions for spectral and energy efficiency with low-resolution ADCs are derived. The multi-objective optimization problem (MOOP) for spectral and energy efficiency is solved by the deep Q network and the non-dominated sorting genetic algorithm II. The simulation results corroborate the theoretical derivation and verify the effectiveness of introducing low-resolution ADCs in NAFD distributed M-MIMO systems. Meanwhile, a set of Pareto-optimal solutions for ADC accuracy flexibly provide guidelines for deploying in a practical NAFD distributed M-MIMO system.

This is the demonstration description for a cloud- based cell-free distributed massive MIMO system, which is based on our already published work. Distributed massive MIMO antennas will result in design and implementation challenges regarding synchronization, calibration, real-time baseband processing, and so on. The contributors propose a cloud-based cellfree distributed massive MIMO system, which cannot only meet 5G NR requirements but also can be easily extended to different application scales. For this demostration, a 128 × 128 distributed MU-MIMO system with frequency 100 MHz@3.5 GHz is given. Test results show that 10.185 Gbps throughput and more than 100 bps/Hz spectrum utilization can be obtained. On-site applications such as HD video transmission and virtual reality (VR) are offered for visitor experiences and interacts.

Massive multiple input multiple output (MIMO) with millimeter-wave (mmWave) techniques is favored by next-generation communication systems for its higher data rates, and higher spectral energy efficiency. Considering the dual-wideband effect existing in the large-scale antenna arrays, a new architecture for uplink (UL) channel estimation based on path-division multiple access (PDMA) is proposed in this paper. To be specific, we focus our attention on a new method based on successive dichotomy to reduce the searching complexity and achieve better performance than the traditional algorithm, where a selection for quantization is given to save resource overhead. Furthermore, a low-cost VLSI architecture for PDMA, which is easy to implement on hardware, is first proposed.

Objective To identify whether Chinese current series of three 5 μg doses for newborn hepatitis B vaccination should be replaced by the series of three 10 μg doses. Methods A cost-effectiveness analysis was conducted from the societal perspective based on the constructed decision tree-Markov model. Model parameters were estimated from published literatures, government documents and our surveys. The expected cost and effectiveness were compared between the 3-dose 5 μg series (the 5 μg strategy) and the 3-dose 10 μg series (the 10 μg strategy), and the incremental cost-effectiveness ratio (ICER, additional cost per quality-adjusted life-years gained) was calculated. Threshold values of the efficacy difference of the two series for the ICER = 0, 1 and 3 times per capita gross domestic product were analyzed under different scenarios to understand whether the 10 μg strategy should replace the 5 μg strategy according to the recommendation of World Health Organization. Results The 10 μg strategy would be cost-saving compared with the 5 μg strategy under the base-case scenario. Under keeping all the other parameters at the base-case values or further adjusting any one of them to the value most unfavorable to the 10 μg strategy, as long as the efficacy of 3-dose 10 μg series was slightly higher than that of 3-dose 5 μg series, the 10 μg strategy would be cost-effective, highly cost-effective, or even cost-saving. Even under the most pessimistic scenario, i.e. all the other parameters, but the discount rate, at the values most unfavorable to the 10 μg strategy, the 10 μg strategy would be cost-effective if the efficacy difference reached higher than 1.23 percentage point. Conclusion For newborn hepatitis B vaccination in China, the 10 μg strategy should be cost-effective, even more possibly highly cost-effective or cost-saving compared with the current 5 μg strategy. The doses of 10 μg should be considered to replace the doses of 5 μg in newborn hepatitis B vaccination in China.

The purpose of the study was to evaluate reliability, validity and sensitivity of the Chinese (simple) SF-36v2 in patients with chronic hepatitis B (CHB). Four hundred and sixty patients were recruited and allocated to CHB (CHB without cirrhosis) (n = 323) and CHB-related cirrhosis (n = 137) groups. Internal consistency reliability was estimated with Cronbach's α-coefficient. Convergent and discriminant validity were assessed by item-scale-component correlation. Factorial validity was explored by principal component factor analysis with varimax rotation. Sensitivity was measured with Cohen's effect size (ES), and independent sample t-test between the CHB and CHB-related cirrhosis groups and between alanine aminotransferase (ALT) normal and abnormal groups after stratifying illness stages. The results showed that Cronbach's α of the total SF-36v2 was 0.92, with the range from 0.72 to 0.87 in the eight scales and 0.76 to 0.77 in the two summary components. Most of the hypothesized item-scale-component correlations were 0.40 or over, and all of such hypothesized correlations were higher than the alternative ones, indicating satisfactory convergent and discriminant validity. Two and seven factors were extracted after varimax rotation at the scale level and item level. The eligible ES with statistically significant independent sample t-test was found in the physical component summary (PCS) and physical function (PF), role-physical (RP), general health (GH), vitality (VT), social functioning (SF) scales by comparison between CHB and CHB-related cirrhosis groups, and in the PCS and PF, GH, SF scales by comparison between the ALT normal and abnormal groups in the stratification of patients with CHB. In conclusion, the Chinese (simple) SF-36v2 has acceptable reliability, validity and sensitivity in patients with CHB.

Objective Few studies have evaluated health-related quality of life (HRQoL) of patients with chronic hepatitis B (CHB) in mainland China. We aimed at characterizing the impact of CHB on HRQoL in mainland Chinese and finding out factors associated with HRQoL. Methods 460 CHB patients (323 with CHB only, 54 with compensated cirrhosis and 83 with decompensated cirrhosis) and 460 pair-matched healthy controls were recruited in Xi’an city. They answered a structured questionnaire including the Short Form 36 version 2 (SF-36v2), the Chronic Liver Disease Questionnaire (CLDQ) (only for patients), and questions on socio-demographic and clinical characteristics. A blood sample was collected from each of patients for liver function tests. SF-36v2 scores were compared between patients and controls overall and by groups by paired-samples t-test, and CLDQ scores and paired differences of SF-36v2 scores were compared among three patient groups by one-way ANOVA or Kruskal-Wallis test. Multi-variable linear regression analyses were performed to identify determinants of HRQoL in patients. Results Patients, overall and by groups had significantly lower SF-36v2 scores than controls on all summaries and domains, with differences higher than the suggested minimally important difference values. Both the SF-36v2 and the CLDQ showed that HRQoL of patients with cirrhosis further deteriorated, but compensated and decompensated cirrhosis patients had similar total HRQoL impairments. The gradually increasing impairment with disease progression was confirmed only on physical components. Impaired liver function and currently taken anti-viral treatment were associated with lower HRQoL. Education attainment and annual per capita household income had a positive effect on HRQoL. Conclusions Mainland Chinese CHB patients suffered significant HRQoL impairment on all health dimensions, and the impairment reached a high level on mental health at initial stage of illness and increased gradually on physical health with disease progression. Attention should be paid to the reduction of patients’ treatment cost burden and the provision of early health education accompanied with proper treatments.

To evaluate psychometrics of the Chinese (mainland) chronic liver disease questionnaire (CLDQ) in patients with chronic hepatitis B (CHB).A cross-sectional sample of 460 Chinese patients with CHB was selected from the Outpatient Department of the Eighth Hospital of Xi'an, including CHB (CHB without cirrhosis) (n = 323) and CHB-related cirrhosis (n = 137). The psychometrics includes reliability, validity and sensitivity. Internal consistency reliability was measured using Cronbach's α. Convergent and discriminant validity was evaluated by item-scale correlation. Factorial validity was explored by principal component analysis with varimax rotation. Sensitivity was assessed using Cohen's effect size (ES), and independent sample t test between CHB and CHB-related cirrhosis groups and between alanine aminotransferase (ALT) normal and abnormal groups after stratifying the disease (CHB and CHB-related cirrhosis).Internal consistency reliability of the CLDQ was 0.83 (range: 0.65-0.90). Most of the hypothesized item-scale correlations were 0.40 or over, and all of such hypothesized correlations were higher than the alternative ones, indicating satisfactory convergent and discriminant validity. Six factors were extracted after varimax rotation from the 29 items of CLDQ. The eligible Cohen's ES with statistically significant independent sample t test was found in the overall CLDQ and abdominal, systematic, activity scales (CHB vs CHB-related cirrhosis), and in the overall CLDQ and abdominal scale in the stratification of patients with CHB (ALT normal vs abnormal).The CLDQ has acceptable reliability, validity and sensitivity in Chinese (mainland) patients with CHB.

In the design of wireless systems, quantization plays a critical role in hardware, which directly affects both area efficiency and energy efficiency. Being an enabling technique, the wide applications of multiple-input multiple-output (MIMO) heavily relies on efficient implementations balancing both performance and complexity. However, most of the existing detectors uniformly quantize all variables, resulting in high redundancy and low flexibility. Requiring both expertise and efforts, an in-depth tailored quantization usually asks for prohibitive costs and is not considered by conventional MIMO detectors. In this paper, a general framework named the automatic hybrid-precision quantization (AHPQ) is proposed with two parts: integral quantization determined by probability density function (PDF), and fractional quantization by deep reinforcement learning (DRL). Being automatic, AHPQ demonstrates high efficiency in figuring out good quantizations for a set of algorithmic parameters. For the approximate message passing (AMP) detector, AHPQ achieves up to $58.7\%$ lower average bitwidth than the unified quantization (UQ) one with almost no performance sacrifice. The feasibility of AHPQ has been verified by implementation with $65$ nm CMOS technology. Compared with its UQ counterpart, AHPQ exhibits $2.97\times$ higher throughput-to-area ratio (TAR) with $19.3\%$ lower energy dissipation. Moreover, by node compression and strength reduction, the AHPQ detector outperforms the state-of-the-art (SOA) in both throughput ($17.92$ Gb/s) and energy efficiency ($7.93$ pJ/b). The proposed AHPQ framework is also applicable for other digital signal processing algorithms.