A HOOI-Based Fast Parameter Estimation Algorithm in UCA-UCFO Framework.

In this paper, we introduce a Reduced-Dimension Multiple-Signal Classification (RD-MUSIC) technique via Higher-Order Orthogonal Iteration (HOOI), which facilitates the estimation of the target range and angle for Frequency-Diverse Array Multiple-Input-Multiple-Output (FDA-MIMO) radars in the unfolded coprime array with unfolded coprime frequency offsets (UCA-UCFO) structure. The received signal undergoes tensor decomposition by the HOOI algorithm to get the core and factor matrices, then the 2D spectral function is built. The Lagrange multiplier method is used to obtain a one-dimensional spectral function, reducing complexity for estimating the direction of arrival (DOA). The vector of the transmitter is obtained by the partial derivatives of the Lagrangian function, and its rotational invariance facilitates target range estimation. The method demonstrates improved operation speed and decreased computational complexity with respect to the classic Higher-Order Singular-Value Decomposition (HOSVD) technique, and its effectiveness and superiority are confirmed by numerical simulations.

High Intensity Focused Ultrasound Ablation for Patients With Locally Advanced Pancreatic Adenocarcinoma: A Propensity Score-Matching Analysis.

OBJECTIVES: This retrospective study was conducted to assess the efficacy and safety of high intensity focused ultrasound (HIFU) in combination with chemotherapy compared with chemotherapy alone in treating patients with unresectable locally advanced pancreatic cancer (LAPC). METHODS: The data of unresectable LAPC patients who received chemotherapy with or without HIFU ablation were retrieved retrospectively. The overall survival (OS), objective response rate (ORR), cancer antigen 19-9 response rate, and safety were compared between these two groups before and after propensity score matching (PSM). RESULTS: Overall, 254 patients with LAPC were included, of whom 92 underwent HIFU ablation. After PSM to control for potential biases, HIFU was associated with improved OS (12.8 versus 12.2 months, log-rank P = .046), as compared to patients without HIFU ablation. Patients with numeric rating scale (NRS) less than 4, and receiving HIFU ablation were significantly associated with improved OS (adjusted hazard ratio [aHR] = 0.365 [95% confidence interval (CI) = 0.148-0.655], P = .002; aHR = 0.490 [95% CI = 0.250-0.961], P = .038; respectively) by multivariate analyses with the adjustment of age, NRS, and tumor size. ORR was also observed to be higher in HIFU group of 30.0% than in the chemotherapy group of 13.3% (P = .039). No severe adverse events of special interest or HIFU-caused deaths were observed. CONCLUSIONS: Patients with unresectable LAPC who received gemcitabine-based chemotherapy might benefit from additional HIFU ablation.

Tensor-Based Angle Estimation Approach for Strictly Noncircular Sources with Unknown Mutual Coupling in Bistatic MIMO Radar.

In the paper, the estimation of joint direction-of-departure (DOD) and direction-of-arrival (DOA) for strictly noncircular targets in multiple-input multiple-output (MIMO) radar with unknown mutual coupling is considered, and a tensor-based angle estimation method is proposed. In the proposed method, making use of the banded symmetric Toeplitz structure of the mutual coupling matrix, the influence of the unknown mutual coupling is removed in the tensor domain. Then, a special enhancement tensor is formulated to capture both the noncircularity and inherent multidimensional structure of strictly noncircular signals. After that, the higher-order singular value decomposition (HOSVD) technology is applied for estimating the tensor-based signal subspace. Finally, the direction-of-departure (DOD) and direction-of-arrival (DOA) estimation is obtained by utilizing the rotational invariance technique. Due to the use of both noncircularity and multidimensional structure of the detected signal, the algorithm in this paper has better angle estimation performance than other subspace-based algorithms. The experiment results verify that the method proposed has better angle estimation performance.