Using Ultrasound-Based Multilayer Perceptron to Differentiate Early Breast Mucinous Cancer and its Subtypes From Fibroadenoma

ObjectivesMucinous breast cancer (MBC), particularly pure MBC (pMBC), often tend to be confused with fibroadenoma (FA) due to their similar images and firm masses, so some MBC cases are misdiagnosed to be FA, which may cause poor prognosis. We analyzed the ultrasonic features and aimed to identify the ability of multilayer perceptron (MLP) to classify early MBC and its subtypes and FA.Materials and MethodsThe study consisted of 193 patients diagnosed with pMBC, mMBC, or FA. The area under curve (AUC) was calculated to assess the effectiveness of age and 10 ultrasound features in differentiating MBC from FA. We used the pairwise comparison to examine the differences among MBC subtypes (pure and mixed types) and FA. We utilized the MLP to differentiate MBC and its subtypes from FA.ResultsThe nine features with AUCs over 0.5 were as follows: age, echo pattern, shape, orientation, margin, echo rim, vascularity distribution, vascularity grade, and tumor size. In subtype analysis, the significant differences were obtained in 10 variables (p-value range, 0.000–0.037) among pMBC, mMBC, and FA, except posterior feature. Through MLP, the AUCs of predicting MBC and FA were both 0.919; the AUCs of predicting pMBC, mMBC, and FA were 0.875, 0.767, and 0.927, respectively.ConclusionOur study found that the MLP models based on ultrasonic characteristics and age can well distinguish MBC and its subtypes from FA. It may provide a critical insight into MBC preoperative clinical management.

Facial Expression Recognition from Video Sequence Using Self Organizing Feature Map

Automatic analysis of facial expressions is rapidly becoming an area of intense interest in computer vision and artificial intelligence research communities. In this paper an approach is presented for facial expression recognition of the six basic prototype expressions (i.e., joy, surprise, anger, sadness, fear, and disgust) based on Facial Action Coding System (FACS). The approach utilizes the topological ordering patterns produced by Kohonen Self Organizing Map, in which implemented on expression image sequence for each prototype facial expression. The map will compute the topological relationship between the particular expression sequences, starting from the neutral expression to peak. This method tried to find a topological ordering pattern (shape) for each expression; it will not require any pre-processing tedious work such as normalization. The only requirement is that, image background must be kept constant, also with non-rigid head motion. The feature extraction phase had been performed by this method, while the classification phase done by especially designed procedures for shape and direction finding to recognize the pattern of the shape, thereafter the type of the expression also backpropagation neural network is implemented for the classification task. An average recognition rate of 88.7% was achieved for six basic expressions, where different databases had been used for the test of the method.

Advantages and Disadvantages of Different Coupling Methods of Plasma Antennas

One of the important challenges in plasma antennas, is the coupling of RF signal to the plasma column. RF signal coupling has a significant effect on antenna efficiency, antenna implementation cost, structure implementation complexity, antenna pattern shape, and final structure weight and volume. In this article, firstly the various methods of coupling were introduced. Then capacitive coupling, direct coupling and sleeve coupling were presented and their advantages and disadvantages were mentioned. As a sample, a plasma folded monopole antenna with sleeve coupling was fabricated and measured. By comparison of the different coupling methods and as a result, one can conclude that the sleeve coupling method is the most suitable method. This method has the least sensitivity to change the dimensions. It is also easy and cheap to implement. In this type of coupling, the efficiency of the Nesta antenna is suitable and the coupling structure adds small weight and volume to the antenna structure.

Research on Evaluation Index of Automotive Antenna Testing

Mounted locations and the ground plane structure have remarkable influences on the performance of roof-mounted automotive antennas. To distinguish this influence in radiation, figure of merits (FoMs), including total radiated power (TRP), near-horizontal part radiated power (NHPRP), and cumulative distribution function (CDF), are studied in this paper. It is proved that TRPs are almost the same with different mounting configurations. Because the radiation toward the horizon is a critical performance metric for automotive antennas, NHPRP is analyzed within certain degrees near the horizon. Even though a bigger deviation has been observed in NHPRP, the discrimination between different mounted scenarios is still not enough. Different from TPR and NHPRP, which are efficiency-based FoMs, CDF combines the gain values and the pattern shape together, achieving a comprehensive and intuitive insight into the antenna performance. It is more predictive and distinguishable in terms of the radiation pattern than NHPRP and TRP. Therefore, CDF can be utilized as a good supplement to existing metrics and can better distinguish the radiation performance of different antenna mounting configurations.

Digital antenna array calibration by adaptive algorithms of signal processing

A method of antenna array calibration, based on the using of the recursive least squares (RLS) adaptive filtering algorithms is discussed. The matrix inversion lemma, the QR-decomposition and the Householder transform based RLS algorithms with quadratic computational complexity can be used for the method implementation in the narrowband adaptive arrays. The proposed calibration method is used in the antenna arrays with digital beam forming. The method demonstrates the ability to estimate and compensate the channel gain errors that ensures the average deviation of the calibrated array radiation pattern shape relatively the radiation pattern shape of the ideal array about –20 dB.

Gelidium gonzalezii sp. nov. (Gelidiales, Rhodophyta) from the Mexican tropical Pacific based on molecular and morphological evidence

There are currently 23 reported species of Gelidium in Mexican Pacific coastal waters. Many of these species require taxonomic verification. Gelidium sclerophyllum is a species reported from the northern Gulf of California to the tropical region of the Mexican Pacific, but there is large morphological variation among populations. The objective of this research was to evaluate this species using a morphological and molecular approach, with COI-5P and rbcL molecular markers. A total of 13 samples were collected from five sites in the Mexican Tropical Pacific. Phylogenetic analyses resolved these specimens within a separate clade from that which includes the type of G. sclerophyllum and other Central American specimens. Differences with other species are subtle and based mainly on size, branching pattern, shape of tetrasporangia sori and size of tetraspores. The sequence divergences and the subtle morphological differences between these two clades support their recognition as two distinct species, and Gelidium gonzalezii sp. nov. is proposed for specimens from the Mexican Tropical Pacific.