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Objectives: To assess the performance of elastography (ES) and ultrasound (US) in predicting the malignancy of breast lesions and to compare their combined diagnostic value with that of magnetic resonance imaging (MRI). Materials and Methods: The study prospectively enrolled 242 female patients with dense breasts treated in 35 heath care facilities in China between November 2018 and October 2019. Based on conventional US and elastography, radiologists classified the degree of suspicion of breast lesions according to the US Breast Imaging Reporting and Data System (BI-RADS) criteria. The diagnostic value was compared between US BI-RADS and MRI BI-RADS, with pathological results used as the reference standard. Results: The results demonstrated that irregular tumor shape, a nonparallel growth orientation, indistinct margins, angular contours, microcalcifications, color Doppler flow and ES score on US imaging were significantly related to breast cancer in dense breasts (P=0.001; P=0.001; P=0.008; P

Background To validate the clinical value of simple rules in distinguishing malignant adnexal masses from benign ones and to explore the effect of simple rules for experienced and less-experienced sonographers. Methods Patients with persistent adnexal masses were enrolled between November 2013 and December 2015. All masses were proven through histological examinations. Five sets of diagnoses were made and compared with one another. Diagnosis 1 was made, according to the simple rules, by a trainee with little clinical diagnostic experience. Diagnoses 2 and 3 were made by experienced and less-experienced sonographers, respectively, according to their clinical experiences. With diagnosis 1 as a reference, the two sonographers were asked to provide a second diagnosis, which were diagnoses 4 and 5. The efficiency of the five sets of diagnoses was compared using ROC curves. Results In total, 75 malignant (37.7%) and 124 benign lesions (62.3%) were enrolled in this study. The mean diameter of the benign masses was obviously smaller than that of the malignant ones (6.8 ± 3.4 cm vs. 9.3 ± 4.9 cm, p

The medium access control (MAC) protocol for indoor visible light communication (VLC) with energy harvesting is explored in this paper. The unfairness of throughput exists among devices due to the significant difference of their energy harvesting rates which changes with distance, acceptance angle and the obstruction probability. We propose an energy harvesting model, a new obstruction probability model and an energy adaptive contention algorithm to overcome the unfairness problem. This device can adjust its contention window according to the energy harvesting rate. As a result, the device with lower energy harvesting rate can get shorter contention window to improve its transmission opportunity. Simulation results show that our MAC protocol can achieve a higher degree of fairness.

The aim of this study was to compare the distribution patterns of microcalcifications in thyroid cancers with benign cases. In total, 358 patients having microcalcifications on ultrasonography were analysed. Microcalcifications were categorised according to the distribution patterns: (I) microcalcifications inside one (a) or more (b) suspected nodules, (II) microcalcifications not only inside but also surrounding a suspected single (a) or multiple (b) nodules, and (III) focal (a) or diffuse (b) microcalcifications in the absence of any suspected nodule. Differences in distribution patterns of microcalcifications in benign and malignant thyroid lesions were compared. We found that the distribution patterns of microcalcifications differed between malignant (n = 325) and benign lesions (n = 117) (X 2 = 9.926, p < 0.01). Benign lesions were classified as type Ia (66.7%), type Ib (29.1%) or type IIIa (4.3%). The specificity of type II and type IIIb in diagnosing malignant cases was 100%. Among malignant lesions, 172 locations were classified as type Ia, 106 as type Ib, 12 as type IIa, 7 as IIb, 7 as type IIIa and 19 as type IIIb. Accompanying Hashimoto thyroiditis was most frequent in type III (51.6%). Types II and IIIb are highly specific for cancer detection. Microcalcifications outside a nodule and those detected in the absence of any nodule should therefore be reviewed carefully in clinical practice. • A method to classify distribution patterns of thyroid microcalcifications is presented. • Distribution features of microcalcifications are useful for diagnosing thyroid cancers. • Microcalcifications outside a suspicious nodule are highly specific for thyroid cancers. • Microcalcifications without suspicious nodules should also alert the physician to thyroid cancers.

In this paper, we consider a problem of relay node optimal placement in mobile robot network. The task needs to deploy a group of robots as relay nodes building connectivity between target node and base station in environment containing obstacle. We model the task as a constrained optimization problem, and decision variables are the number of robots and the positions of them. To address this issue, we propose a visibility overlap region based relay node optimal placement algorithm, which is efficient heuristic method. The algorithm divides the problem into three sub-problems, which are path-planning between target node and base station, line-of-sight based relay node positions determined, and visibility overlap region based relay nodes combined and position optimization. We justify our algorithm’s correctness by simulation experiment.

This paper presents a simultaneous localization, mapping (SLAM) and object tracking (OT) method based on laser and camera data fusion to achieve simultaneous estimation of robot state, environment features states and object’s trajectory in unknown environments. The proposed algorithm is using Full-Correlation Extended Kalman Filter (FCEKF) frameworks, and the system state is combination of robot state, feature states and object state. Object observation is come from two sensors, one is camera and the other is laser. Camshift method is used to get object measurements from camera image, at same time, consistency grid map method is used to get the same object measurements from laser ranger finder, those same object measurements come from different sensor is inputted to FCEKF, and improving robustness and accuracy of system state estimation. The experimental results show that the proposed algorithm is effective to object tracking in outdoor unknown environments.

The aims of this paper is to promote object detection and tracking ability of mobile robot in outdoor unknown environments, which based on integration of camera and laser ranger finder data information. First, Camshift method is used to track area of target in image which observed by camera. Second, consistency grid map method is used to detect this moving target based on laser ranger finder observation. Next, two states of the target come from laser and camera sensors are fused to update error of estimation and the new state of target helps to determine search window of Camshift in next loop. Finally, a global optimization method is proposed to improve accuracy of laser-camera calibration. The experimental results show that the proposed algorithm is effective to track object in outdoor unknown environments.

This paper presents a novel approach for simultaneous localization, mapping (SLAM) and detection of moving object based on information fusion. We use different information sources, such as laser range scanner, and monocular camera, to improve the ability of distinction between object and background environment. The approach improves the accuracy of SLAM in complex environment, reduces the interference caused by objects, and enhances the practical utility of traditional methods of SLAM. Moreover, the approach expands fields of both research and application of SLAM in combination with target tracking method. Results in real robot experiments show the effectiveness of our method.

Patent complementarity between enterprises determines the investment strategy of corporate patents. This paper is based on symmetric duopoly model, with respect to the level of complementary patented technologies in the enterprise, we give discussions to consider which patents investment strategy for asymmetric duopoly enterprises should be taken in both cases, in cooperation or non-cooperation, and present the final value of the patent investment decision.