In medium-size Massive MIMO systems, the minimum mean square error parallel interference cancellation (MMSE-PIC) based Soft-Input Soft-Output (SISO) detector is often used due to its relatively low complexity and good bit error rate (BER) performance. The computational complexity of MMSE-PIC for detecting a block of data is dominated by the computation of a Gram matrix and a matrix inversion. They have computational complexity of O(K 2 M) and O(K 3), respectively, where K is the number of uplink users with one transmit antenna each and M is the number of receive antennas at the base station. In this letter, by using an L (typically L ≤ 3) terms of Neumann series expansion to approximate the matrix inversion, we reduce the total computational complexity to O(LKM). Compared with alternative algorithms which focus on reducing the complexity of the matrix inversion only, the proposed method can also avoid calculating the Gram matrix explicitly and thus significantly reducing the total complexity.

The present study aimed to investigate the clinical outcomes of percutaneous transhepatic biliary drainage in patients with obstructive jaundice and identify potential predictors of patient survival. Clinical data from 102 patients (66 males and 36 females; median age, 63.50 years; range, 29–84 years) with a mean (± standard deviation) pre-drainage serum bilirubin level of 285.4 (±136.7 μmol/l), were retrospectively studied. Technical and clinical success, complications and survival time were recorded and their relationship with clinical factors, including age, obstruction level, liver metastases, serum bilirubin level and subsequent treatments following drainage, were analyzed by Fisher’s exact test. Patient survival rate and other predictors were analyzed by Kaplan-Meier survival curves and Cox’s proportional hazard model. The technical and clinical success rates were 100 and 76.5%, respectively. The presence of liver metastases was associated with reduced successful drainage. The overall complication rate was 7.8% and the overall median survival time was 185 days [95% confidence interval (CI), 159–211 days]. A log-rank test showed that age (χ2, 4.003; P=0.04), bilirubin levels following procedure (χ2, 5.139; P=0.02) and subsequent therapy (χ2, 15.459; P=0.00) affected survival time. However, Cox’s regression analysis revealed no administration of additional treatments to be a risk factor of survival (odds ratio, 2.323; 95% CI, 1.465–3.685; P=0.000). Percutaneous transhepatic biliary drainage for malignant biliary obstruction was found to be a safe and effective method to relieve jaundice caused by progressive neoplasms. Subsequent radical therapy following drainage, including surgery, chemotherapy and other local treatment types, are likely to increase patient survival.

Visual Place Recognition (VPR) is an important component in both computer vision and robotics applications, thanks to its ability to determine whether a place has been visited and where specifically. A major challenge in VPR is to handle changes of environmental conditions including weather, season and illumination. Most VPR methods try to improve the place recognition performance by ignoring the environmental factors, leading to decreased accuracy decreases when environmental conditions change significantly, such as day versus night. To this end, we propose an end-to-end conditional visual place recognition method. Specifically, we introduce the multi-domain feature learning method (MDFL) to capture multiple attribute-descriptions for a given place, and then use a feature detaching module to separate the environmental condition-related features from those that are not. The only label required within this feature learning pipeline is the environmental condition. Evaluation of the proposed method is conducted on the multi-season NORDLAND dataset, and the multi-weather GTAV dataset. Experimental results show that our method improves the feature robustness against variant environmental conditions.

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Our results indicate that TSAE for patients with hypersplenism not only delivers a better long-term outcome, but is also associated with lower complication rates and a shorter hospital stay than PSE.

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