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Published By World Scientific And Engineering Academy And Society (WSEAS)

1109-2742

2021 ◽  
Vol 20 ◽  
pp. 177-184
Author(s):  
Ozer Ozdemir ◽  
Simgenur Cerman

In data mining, one of the commonly-used techniques is the clustering. Clustering can be done by the different algorithms such as hierarchical, partitioning, grid, density and graph based algorithms. In this study first of all the concept of data mining explained, then giving information the aims of using data mining and the areas of using and then clustering and clustering algorithms that used in data mining are explained theoretically. Ultimately within the scope of this study, "Mall Customers" data set that taken from Kaggle database, based partitioned clustering and hierarchical clustering algorithms aimed at the separation of clusters according to their costumers features. In the clusters obtained by the partitional clustering algorithms, the similarity within the cluster is maximum and the similarity between the clusters is minimum. The hierarchical clustering algorithms is based on the gathering of similar features or vice versa. The partitional clustering algorithms used; k-means and PAM, hierarchical clustering algorithms used; AGNES and DIANA are algorithms. In this study, R statistical programming language was used in the application of algorithms. At the end of the study, the data set was run with clustering algorithms and the obtained analysis results were interpreted.


2021 ◽  
Vol 20 ◽  
pp. 172-176
Author(s):  
Tain-Sou Tsay

In this literature, a low-cost small loop antenna is developed for radio direction finding. It consists of two coupled rectangular counter-wiring loop antennas. A signal-processing circuit is developed also for demodulated outputs. A single rectangular loop antenna is discussed first for illustrating the receiving characteristics and then the proposed two coupled rectangular counter-wiring loop antennas are designed for radio direction finding. Measurements give a large linear detecting range. It is ready for Omni-directional application using another two coupled loop antennas and can be used as a tracking control device.


2021 ◽  
Vol 20 ◽  
pp. 152-171
Author(s):  
Vyacheslav Tuzlukov

In this paper the multicarrier direct-sequence code-division multiple access (MC DS-CDMA) using space-time spreading assisted transmit diversity is investigated in the context of broadband wireless communi-cations systems constructed based on the generalized approach to signal processing in noise over frequency-se-lective Rayleigh fading channels. We consider the issue of parameter design for the sake of achieving high-ef-ficiency communications in various dispersive environments. In contrast to the conventional MC DS-CDMA wireless communication system employing the time (T)-domain spreading only, in the present paper the broad-band wireless MC DS-CDMA wireless communication schemes employ both the time (T)-domain and frequen-cy (F)-domain spreading, i.e., employ the TF-domain spreading. The bit-error rate (BER) performance of the space-time spreading assisted broadband MC DS-CDMA wireless communications system is investigated for down-link transmissions associated with the single user and multiuser generalized detectors and is compared with that of the single user correlation detector and the multiuser decorrelating detector. Our study demonstra-tes that with appropriately selecting the system parameters, the broadband MC DS-CDMA wireless communi-cation system using the space-time spreading assisted transmit diversity constitutes a promising downlink tran-smission scheme. This scheme is capable to support ubiquitous communications over diverse communication environments without the BER performance degradation


2021 ◽  
Vol 20 ◽  
pp. 146-151
Author(s):  
Edgar Alejandro Andrade-Gonzalez ◽  
Juan Carlos Ordoñez-Martínez ◽  
Mario Reyes-Ayala ◽  
José Alfredo Tirado Méndez ◽  
Hilario Terres-Peña

In this article, a compact ultra-wide band (UWB) multiple input multiple output (MIMO) antenna system is showed. This antenna is based on fractal Fibonacci circles and operates over wide frequency range from 2.9 to 14.51 GHz. The dielectric used was Duroid substrate with dielectric constant εr = 2.2 and thickness of substrate 1.27 mm. This UWB MIMO antenna is simulated by HFSS. In order to improve the isolation between the elements of the antenna a parasitic structure is used, getting S12 and very low ECC. Also, the Total Active reflection Coefficient (TARC) was obtained. Proposed antenna can be used for UWB communication applications and its size is 64 × 38mm2


2021 ◽  
Vol 20 ◽  
pp. 112-116
Author(s):  
Sivaranjan Goswami ◽  
Kandarpa Kumar Sarma ◽  
Kumaresh Sarmah

Synthesis of sparse arrays is a promising area of research for a wide range of applications including radar and millimeter-wave wireless communication. The design goal of array thinning problems is to reduce the number of elements of an array without significantly affecting its performance. This work presents a technique for synthesizing a sparse phased-array antenna from a 16×16 uniform rectangular array (URA). The proposed approach reduces the number of elements by 50% without any significant increase in the peak sidelobe level (PSLL) for all possible scan angles in the azimuthal and elevation plans within a finite range of scan angles. The synthesis includes an artificial neural network (ANN) model for estimation of the excitation weights of the URA for a given scan-angle. The weights of the sparse array are computed by the Hadamard product of the weight matrix of the URA with a binary matrix that is obtained using particle swarm optimization (PSO) to minimize the PSLL.


2021 ◽  
Vol 20 ◽  
pp. 128-132
Author(s):  
Rashmi Hazarika ◽  
Manash Pratim Sharma

A low noise amplifier (LNA) plays a very significant role in communication systems. Despite having a good amplification of the signal it must offer other attributes like noise figure, linearity etc for making the communication system more robust. With the advent of 5G communication, the requirement of a high BW LNA is becoming important. This paper presents the design of a LNA which have a common gate input configuration, an active inductor in place of a passive inductor, common drain amplifier at the output stage and a linearity circuit. Common gate amplifier offers a good voltage amplification while the common drain stage enhances the stability. The active inductor facilitates reduction of the die area paving the way for a cost efficient structure. This proposed design achieves a gain of 15.17dB with substantial enhancement of linearity. A good noise figure of 7dB is obtained while using 11 transistors and eliminating the need of passive inductors. The peak gain is achieved at 3.5GHz


2021 ◽  
Vol 20 ◽  
pp. 118-122
Author(s):  
Nupur Choudhury ◽  
Chinmoy Kalita ◽  
Kandarpa Kumar Sarma

Of late, Software Defined Radio (SDR) approach has become an effective means to design high data rate wireless systems for a range of applications. There are methods with which low cost SDR based 4th generation (4G) or long term evolution (LTE) systems can be designed. Using low cost Raspberry Pi systems, the SDR aided 4G systems can be designed for high data rate communication. The work is related to the design of a 4G wireless system using low cost SDR solutions and integrated to a programmable controller based on a Raspberry Pi. Experimental results show that the system is effective in a range of conditions


2021 ◽  
Vol 20 ◽  
pp. 123-127
Author(s):  
Juhi K. Baruah ◽  
Kandarpa Kumar Sarma ◽  
Sivaranjan Goswami

In this work, a 2×2 grid of E-shaped patch antennas is proposed. The design of the grid is achieved through the design of a single element, the design of a 1×2 array and finally the design of the 2×2 grid on an FR4 epoxy substrate of thickness 1.5 mm. A corporate feed network of microstrip lines is used to excite the array. The performance of each stage is studied in terms of the return loss parameter, the far field gain, and the beam-widths are observed in each case from simulation results. The resonant frequency in each case is 3.8 GHz. It is observed that as the number of elements is increased, the beam-width reduces. In other words, the directivity is increased. Further, it is also observed that the gain and bandwidth is the minimum for the single patch, followed by that of the 1×2 array and the maximum for the 2×2 grid. Thus, the construction of the grid leads to increase in gain, bandwidth and directivity of the antenna.


2021 ◽  
Vol 20 ◽  
pp. 139-145
Author(s):  
Ray-I Chang ◽  
Yu-Hsien Chu ◽  
Chia-Hui Wang ◽  
Niang-Ying Huang

Wireless Sensor Networks (WSNs) contain many sensor nodes which are placed in chosen spatial area to temporally monitor the environmental changes. As the sensor data is big, it should be well organized and stored in cloud servers to support efficient data query. In this paper, we first adopt the streamed sensor data as "data cubes" to enhance data compression by video-like lossless compression (VLLC). With layered tree structure of WSNs, compression can be done on the aggregation nodes of edge computing. Then, an algorithm is designed to well organize and store these VLLC data cubes into cloud servers to support cost-effect big data query with parallel processing. Our experiments are tested by real-world sensor data. Results show that our method can save 94% construction time and 79% storage space to achieve the same retrieval time in data query when compared with a well-known database MySQL


2021 ◽  
Vol 20 ◽  
pp. 133-138
Author(s):  
Khushboo Teronpi ◽  
Kandarpa Kumar Sarma ◽  
Aradhana Misra ◽  
Manasjyoti Bhuyan

Modulation detection is one of the major tasks of an intelligent receiver in a software defined radio (SDR). It is an intermediate step between signal detection and demodulation. In this paper we present the modulation detection based on Dynamic Time Warping (DTW) algorithm. Here the types of modulation that we use are QPSK, 8-PSK, 16-QAM and 64-QAM. The whole test and verification has been done with the help of SDR platform. After the test and trials of all the modulation schemes, it is observed that DTW provides a good efficiency with the accuracy of 93.75%.


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