A Compact Switched Beam Antenna Array for ISM Band

This paper proposes the switched beam antenna array at the center frequency of 2.45GHz with a bandwidth of 187 MHz, from 2.32 GHz to 2.51 GHz. The phase shifter of antenna utilizes a 4×4 planar Butler matrix with phase differences between its outputs of  ±135° and ±45° to obtain four the different main beam directions. The proposed design is fully described including the patch antenna element, the antenna array, the phase shifter that forms the completed antenna array. The antenna array achieves a gain max up to 7 dBi, and the angles of the main beam directions of -41°, -12°, +15°, +48° in a horizontal plane. The beamwidth of the four main beams is from 26°  to 31.8° in E-plane and from 38.5° to 55.4° in H-plane. The advantage of the antenna is the planar structure and compact dimension of 200×230mm2. The proposed antenna is suitable for ISM band

Investigating the Performance of SCM/MMW/RoF Optical-Wireless Access System for Next Generation Communications

In this paper, we propose a model of subcarrier multiplexing millimeter wave radio-over-fiber SCM/MMW/RoF optical-wireless access system for next generation mobile communications using QPSK modulation. We then calculate signal and total noise power at the end of optical fiber link and at mobile subscribers through wireless medium. Next, system performance showed by SNR, BER at the end of system is determined. They are investigated, compared, evaluated by Matlab in many different scenarios including BER performance versus EDFA’s Gain, optical transmitter power at central office (CO), optical oscillator power in coherent receiver, wireless frequencies, wireless link distance corresponding to two wireless cases of Line of Sight (LoS) and Non Line of Sight (NLoS). Numerical results show that when number of SCM channels increase system performance becomes worse due to nonlinear effect in SCM modulation

Interrior and Surface Mounted Permanent Magnet BLDC Motor for Inwheel Electric Vehicles

This paper presents electromagnetic design and analysis of an interior and surface mounted and permanentmagnet BLDC motor for independent four-wheel drives. The designed motors of 25kWIP

Design of Silicon TE0/TE1 Mode Router Using Mach-Zehnder and Multimode Interferometers

This paper proposes a new design of two-mode three-port optical mode router for mode division multiplexing systems. The device consists of a Mach-Zehnder interferometer (MZI) and a multimode interferometer (MMI), which utilizes silicon material for photonic integrated circuits (PIC). By setting appropriate values for the two butterfly-shaped phase shifters (PSs) at MZI and MMI, the input mode, either transverse electric (TE) modes TE0 or TE1, can be routed to the desired output among the three output ports. The device is designed and optimized via three-dimensional beam propagation method (3D BPM). The proposed device achieves very low insertion loss and small cross-talk, which are less than 0.4 dB and -24.5 dB, respectively, over the whole C band

Improving transmission network using renewable resources efficiency by integrating pumped-storage hydroelectricity

Due to the increasing load demand, integrating renewable energy into the power system to satisfy the electrical consumption is the trend to develop the modern power system. However, the uncertainty of renewable energy sources affects the energy transmission efficiency and the reliability of power systems. To get this under control, connecting storage systems such as pump-storage hydroelectricity is seen to be an efficient solution. In this paper, Python language is used to describe input data and model the Vietnamese power system. The results show the feasibility of the hydro-storage model in improving the power system performance when renewable energy sources are involved

Analysis of First- and Second-Order Digital DS Modulator Used in Fractional-N PLLs

In this paper, we analyze for the first time behavior in the time domain of the accumulated quantization error induced by the first- and second-order digital DeltaSigma modulator (DSM). The DSM is adopted in fractional-N PLLs to dither frequency division factor. From the analysis, difference in behavior of the accumulated quantization error in the two cases is clearly explained. Furthermore, by mean of this, the reason of using second-order DSM is required for the calibration loop of digital/time converter canceling the quantization error is revealed. It also explains why there is variation in convergence time even with the second-order DSM when fractional part of the division factor changes

A Tracking Bracelet Device for Kids with Detachment Warning Function

In this paper, we design a tracking bracelet device for kids with novel function that can detect in real-time whether the device is still attached or not. The novel function in combined with setting of a safe zone yields an absolute tracking of thekid safety. A prototype is implemented achieving a small size of 60 x 60 x 25 mm. The test results demonstrate that the proposed device works very well with 100 % of exact warning when the kids are assumed in danger. Moreover, thanks to alow power consumption of about 64 mW in average, the device is expected to work continuously at least 18 hours

Analyzing cancer data in North Vietnam by complex network technique

Data-clustering tools can be employed to generate new knowledge for the diagnosis and treatment of cancer. However, traditional clustering methods, such as the K-mean approach, often require the determination of input parameters such as the cluster number and initial centers to be viable. In this study, we present a network science-based clustering method with fewer parameters that were used to mine a cancer-screening dataset containing over 177,000 records. We propose an algorithm that computes the similarity between pairs of records to create a complex network in which each node represents a record, and two nodes are connected by an edge if their similarity is greater than a given threshold as determined by experimental observation. Based on the network created, we employed the network modularity optimization algorithm to detect modules (clusters) within it. Each cluster contains records that are similar to one another in terms of some attributes; therefore, we could derive rules from the cluster for insights into the cancer situation in Vietnam. These rules reveal that some cancer types are more widespread in specific families and living environments in Vietnam. Clustering data based on network science can therefore be a good option for large-scale relational data-mining problems in the future

On efficient designing of protograph LDPC codes

This paper designs two protograph LDPC codes with code-rate R > 1/2. A simple method using the protograph extrinsic information transfer (PEXIT) to design the codes with a low decoding threshold and the asymptotic weight enumerator (AWE) to evaluate the error floor of the codes is deployed. Simulation results show that the proposed codes have a better error floor than prior art protograph codes and offer higher rate protographs

A Knowledge Graph Approach for the Detection of Digital Human Profiles in Big Data

Digital transformation is a long process that changes the managing human profiles in both offline and online approaches. This generates the amount of huge data stored in both relational databases and many others like social networks or graph databases. To exploit effectively big data, several measures and algorithms in Picture Fuzzy Graph (PFG) are applied to solve many complex problems in the real-world problems. The paper has presented a novel approach using a knowledge graph to find a human profile including the detection of humans in large data. In the proposed model, digital human profiles are collected from conventional databases combination with social networks in real-time, and a knowledge graph is created to represent complex-relational user attributes of human profile in large datasets. PFG is applied to quantify the degree centrality of nodes. Furthermore, techniques and algorithms on the graph are used to classify the nodes. The experiments in the knowledge graph implemented to illustrate the proposed model. The main contribution in this paper is to identify the right persons among complex-relational groups, locations in real-time based on large datasets on the social networks, relational databases and graph databases