Direction finding of acoustic sources has special importance in military and industrial applications. Lots of algorithms are proposed for solving this problem but, as the complicated conditions of environment enter the problem, a common method with arbitrary precision does not exist for all situations. One of these cases is finding the direction of acoustic sources in multi reflection media such as shallow waters. In this case, many virtual sources are born which are copies of independent sources and are neither detectable nor removable. When the number of these reflections are more than the number of array sensors, the assumptions of customary direction-finding methods are not satisfied and therefore these methods are no longer applicable. In this case, we are facing a problem that the number of signal sources are more than the number of sensors. An important idea for handling this multipath phenomenon, is to increase the degree of freedom of the sonar array which can be solved based on the sparse arrays. Actually, employing the MRA array, will increase the number of real array sensors virtually so that the problem will return to the ordinary conditions. In this idea, the array manifold matrix is modified to be proportional to the sparse non-uniform array. Simulations confirm the function of the proposed algorithm in the presence of correlated sources that have low error and high angular resolution so that, by 6 real array sensors, this algorithm could find the direction of 12 sources whether independent or correlated. This algorithm is very close to CRLB limit and is better than all compared methods.

In conventional phased array systems, increasing the array length and consequently increasing the number of antenna elements are needed to improve spatial resolution. It can be addressed by MIMO radars using orthogonal signals from multiple transmitters and using the virtual array. Virtual element's locations are derived from the convolution of the physical element's location of the transmitter and receiver. To understand the functionality of MIMO radars, virtual array has been introduced. As the virtual array be larger, the radar angle resolution increase. Increasing the degree of freedom of the virtual array is highly dependent on the array of transmitter and receiver elements placement. The nested array which is one of the well-known methods in alignment of MIMO radar array elements, is investigated. In this article, the new nested array is examined and implemented in one dimension. The very innovative idea of this article is to use the new 2D nested array. A multi-step approach for implementing two-dimensional arrays using a new nested array for a MIMO radar is presented which can be generalized to any other structure with different number of elements. Finally, the advantages of the proposed method in terms of angular beam width of the main radar are presented. The results show that the proposed method is much more efficient than the other methods. The comparative results presented at the end of this article shows that the half-power beam width of the proposed method is approximately 0. 3 degrees while this value for the nested method is more than 2 degrees.

The method of multi-beam beamforming is a low-computational adaptive beamforming method in which, instead of calculating the covariance matrix and inverting it for each point of the image, only one matrix is calculated for all points on the same radial distance. Then, to reduce the complexity of the inverse matrix calculation, the problem is solved in the beamspace domain. We introduce a new two-stage method to reduce the complexity of the minimum variance (MV) beamforming method, which outperforms the beamspace method in computational burden aspect in multi-beam method. In the first step, instead of using the signals of all array elements in calculating the covariance matrix, the signals of a decimated one are chosen such that the resulting covariance matrix contains all the correlation information of the signals. In the second stage, the weights of all elements of the array are determined by a proper interpolation method from the weights of the decimated array. According to the simulation results of point targets and cyst phantom, the new method has a performance similar to that of the beamspace multi-beam method in terms of resolution, contrast, and robustness against the errors with at least 3 times lower computational burden.

MUSIC (Multiple Signal Classification) algorithm as a base of Sub-Space algorithms is applied in array processing systems. The error of the algorithm in detection & resolution depends on several parameters, such as snapshots, signal-to-noise ratio and sensor locations. In this paper, the previous dependency is investigated. So, all the scenarios of array shapes are defended and then i analytic formulas are derived in two bearings of θ and φ We will show which parameters have ithe most effect on the desired error (the error threshold).

Introduction: Colorectal Carcinoma is a main health problem in many countries and the third common cancer in Iran. This malignancy at present is the most curable carcinoma of gastrointestinal tract. Variation in the expression of the proteins produced by P53, P21, P16, E-cadherin, and β-catenin genes have been noted in this malignancy and may be important in the prognosis and therapeutic response rate. The aim of this study was to compare the frequency and pattern of expression of these proteins in tumoral and nontumoral colonic mucosa. The correlation with prognostic factors including tumor stage, grade, and vascular and perineural invasion was also determined. Material and Methods: The paraffin blocks from tumoral and nontumoral parts of the colon obtained from 58 patients with colorectal adenocarcinoma were studied along with 50 colectomic cases in individuals without malignancy. Cylindrical tissue fragments were obtained from appropriate parts of donor blocks by using a 2.5 mm punch biopsy instrument. Each 30 samples were manually arrayed in one tissue array block. Expression of above genes was investigated after sectioning the blocks and immunohistochemical staining of slides. Results: The expression of P53 in tumor cells was significantly more common than in colonic nontumor cells and colon of individuals without tumor (p<0.001); expression of this protein in tumoral tissues was directly related to vascular invasion (p=0.017). The expression frequency of P21 and P16 in tumor cells was less than nontumoral tissues of patients with cancer and patients without cancer (p<0.001). These two gene products showed no correlation with prognostic factors. The expression frequency of membranous E-cadherin and β-catenin in tumor cells was not different from controls, while the membranous expression of E-cadherin was inversely related to cell differentiation (p=0.023) and vascular invasion (p=0.025). In addition, the membranous expression of β-catenin was inversely related to vascular invasion (p=0.049). Cytoplasmic and nuclear expression of β-catenin in tumor cells were significantly higher than their expression in the controls (p<0.001). Cytoplasmic expression of this marker was inversely related to disease stage (p=0.013), while its nuclear expression was inversely related to cell differentiation (p=0.012).Conclusion: According to our data, it seems that we are able to predict aggressive capacity of the colorectal tumor by determining the frequency and pattern of expression of P53, E-cadherin and β-catenin proteins. These studies can be done simply on formalin-fixed small biopsy samples before surgery to provide valuable information for surgeons, gastroenterologists, and oncologists to choose the best therapeutic approach and predict the therapeutic response. Manual tissue array method is believed to be an economical technique for similar research projects.

Chromosome microarray is being suggested and replacing karyotype as first tier diagnostic test for individuals with unexplained developmental delay/intellectual disability (DD/ID), autism spectrum disorders (ASD), or multiple congenital anomalies (MCA). Chromosome microarray gives a diagnostic yield of 15-20% for genetic testing of individuals with DD/ID, ASD or MCA compared to 3% in karyotype (excluding Down syndrome and other recognizable chromosomal syndromes). We present the results of chromosome microarray performed on 110 individuals with DD/ID, ASD or MCA. From the 110 cases, 23 cases (20.9%) showed copy number variations, of which 13 were deletions, 5 were duplication and 5 were duplication and deletion. The limitations of chromosome microarray are for detection of balanced translocation and low-level mosaicism, but these chromosomal abnormalities are rare causes of abnormal phenotypes in this category of patients.

Today, literature and poetry have a more comprehensive definition than mere literary expression with academic meanings and tools. Literature is the collection of all the scientific abilities of the language in the field of structure and richness. The artistic creativity of the poet and the employment of excellent compositions and themes lead to the production of a literary and artistic work, which can be found in the excitement and expansion of the audience. The aim of this research is to reach the communication network of all the factors related to the language and the appearance of the word, which not only carries the meaning, but also creates a different meaning and concept from the apparent meaning that results from the phonetic, lexical or visual mechanism. A network that is referred to as "artwork". Artistic device (prime) is a meta-array approach to the aesthetic tools of language in poetry, which formalists consider to be the art of alienating language from the mind of the audience.