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Human–robot interaction has extended its application horizon to simplify how human beings interact with each other through a remotely controlled telepresence robot. The fast growth of communication technologies such as 4G and 5G has elevated the potential to establish stable audio–video-data transmission. However, human–robot physical interactions are still challenging regarding maneuverability, controllability, stability, drive layout, and autonomy. Hence, this paper presents a systematic design and control approach based on the customer’s needs and expectations of telepresence mobile robots for social interactions. A system model and controller design are developed using the Lagrangian method and linear quadratic regulator, respectively, for different scenarios such as flat surface, inclined surface, and yaw (steering). The robot system is capable of traveling uphill (30\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{\circ }$$\end{document}∘) and has a variable height (600–1200 mm). The robot is advantageous in developing countries to fill the skill gaps as well as for sharing knowledge and expertise using a virtual and mobile physical presence. Electronic supplementary material The online version of this article (10.1007/s12369-020-00676-3) contains supplementary material, which is available to authorized users.

Classification of samples into one or more populations is one of the main objectives of gene expression data (GED) analysis. Many machine learning algorithms were employed in several studies to perform this task. However, these studies did not consider the outliers problem. GEDs are often contaminated by outliers due to several steps involve in the data generating process from hybridization of DNA samples to image analysis. Most of the algorithms produce higher false positives and lower accuracies in presence of outliers, particularly for lower number of replicates in the biological conditions. Therefore, in this paper, a comprehensive study has been carried out among five popular machine learning algorithms (SVM, RF, Naïve Bayes, k-NN and LDA) using both simulated and real gene expression datasets, in absence and presence of outliers. Three different rates of outliers (5%, 10% and 50%) and six performance indices (TPR, FPR, TNR, FNR, FDR and AUC) were considered to investigate the performance of five machine learning algorithms. Both simulated and real GED analysis results revealed that SVM produced comparatively better performance than the other four algorithms (RF, Naïve Bayes, k-NN and LDA) for both small-and-large sample sizes. J. bio-sci. 28: 69-80, 2020

With the rapid development of high-throughput DNA microarray technologies, researchers can measure expression profiles of thousands of genes simultaneously with low costs. These massive amounts of gene expression (GE) data often contain missing values or outliers due to various reasons of data generating process. Most of the statistical methods were developed based on complete dataset. As a result, for subsequent analysis using incomplete dataset, these methods strongly suffer and we cannot find our target. A numerous methods have been developed to impute missing values and they are available in the literature. Albeit, missing values imputation and outliers handling both are equally important for analyzing GE, most of the methods perform these tasks separately and produce misleading results. Therefore, in this paper, an attempt is made to develop a new hybrid approach which is robust against outliers and missing values, simultaneously. We demonstrate the performance of the proposed method in a comparison of popular missing value imputation method K-NN while performing feature selection using both simulated and real GE datasets. The Results obtain from simulated as well as real data studies show that the proposed method outperforms K-NN in presence of different percentages of missing values and outliers. On the other hand, in absence of outliers with missing values, the proposed method keeps equal performance with the other methods. J. bio-sci. 27: 31-41, 2019

This paper presents localization of tumor at 13 different positions deep inside a dense human breast using only 4 meander line microstrip patch antennas of operating frequency 1.5 GHz for the detection of breast cancer. The reflection coefficients of the antennas demonstrates a very uniform pattern for localization of the tumors in CST Microwave Studio simulation environment. The result of this work can help to develop a portable medical device for breast cancer detection at home by analyzing the reflection coefficient data of the 4 antennas.

This article proposed a novel miniaturized design of coplanar wave guide (CPW) fed ultra wide band (UWB) tapered slot Vivaldi antenna for microwave imaging applications. Broken line exponential tapered profile and different types of slots have been incorporated in order to obtain the better performance and miniaturized antenna. All the important performance parameters of the proposed antenna such as return loss, BW, gain, directivity, VSWR, axial ratio, front to back ratio, accepted power, radiated power, surface current, radiation efficiency have been analyzed and enhanced up to the acceptable level. Finally, from the simulated validation, it is noticed that the proposed antenna would be a potential candidate for microwave imaging applications.

This paper presents a wearable planar printed meandering monopole textile antenna design having operating frequency of 2.4 – 2.45 GHz on 3 flexible substrate materials: Jeans, Leather and Cordura®. The printed elements have been designed by using a mender line technique to reduce the size of the antenna significantly than the proposed antennas of past literature. Antenna performance is analyzed for different bending conditions and Specific Absorption Rate (SAR) is evaluated when the antenna is in contact with human body using CST Microwave Studio. The compact design and miniature size of the antenna is suitable for easy integration in smart clothing for tracking, healthcare, security and other ISM applications.

Background: One of the main goals of RNA-seq data analysis is identification of biomarkers that are differentially expressed (DE) across two or more experimental conditions. RNA-seq uses next generation sequencing technology and it has many advantages over microarrays. Numerous statistical methods have already been developed for identification the biomarkers from RNA-seq data. Most of these methods were based on either Poisson distribution or negative binomial distribution. However, efficient biomarker identification from discrete RNA-seq data is hampered by existing methods when the datasets contain outliers or extreme observations. Specially, the performance of these methods becomes more severe when the data come from a small number of samples in the presence of outliers. Therefore, in this study, an attempt is made to propose an outlier detection and modification approach for RNA-seq data to overcome the aforesaid problems of traditional methods. We make our proposed method facilitate in RNA-seq data by transforming the read count data into continuous data. Methods: We use median control chart to detect and modify the outlying observation in a log-transformed RNA-seq dataset. To investigate the performance of the proposed method in absence and presence of outliers, we employ the five popular biomarker selection methods (edgeR, edgeR_robust, DEseq, DEseq2 and limma) both in simulated and real datasets. Results: The simulation results strongly suggest that the performance of the proposed method improved in the presence of outliers. The proposed method also detected an additional 18 outlying DE genes from a real mouse RNA-seq dataset that were not detected by traditional methods. Using the KEGG pathway and gene ontology analysis results we reveal that these genes may be biomarkers, which require validation in a wet lab. Conclusions: Our proposal is to apply the proposed method for biomarker identification from other RNA-seq data.

Vertically stacked pruned optical banyan networks with extra planes (in short, EP-VSOB networks) have lower switch count and optimal time complexity (O(log2 N)) for routing N input requests. However, blocking probability is relatively higher than that of a VSOB networks using regular banyan planes. In the EP-VSOB architecture, the number of pruned planes has always been considered as N , and a few extra planes (regular banyan) have been added with these pruned planes. In this paper we present the results of blocking analysis of a more generalized architecture in which the number of pruned planes can be 2x, where x ⩾ 0 in addition to the variable extra planes. This generalization helps us make a compromise between different constraints and performance metrics. Our simulation results show that for some given performance requirements (e.g. cost, speed or blocking probability) we can choose a network that has lower switch count compared to N -plane pruned crosstalk-free optical banyan networks. For example, to ensure blocking probability

In this paper, we address the issue of faster connection establishment in a large vertically stacked optical Banyan (VSOB) network. The best known global routing algorithm, which turns an N × N crosstalk-free VSOB network into a rearrangeably non-blocking one, has time complexity O ( N log N ). This is quite large compared to O ( N log N ) time complexity of a single plane banyan network, which is a self-routing network with very high blocking probability. For a large size of switching network this O ( N log N ) time complexity may result unacceptably long delay. Therefore, an optical network with very low blocking probability and O ( N log N ) time complexity will be useful. Previously proposed Plane Fixed Routing (PFR) algorithm has O (log N ) time complexity but results in higher than 2% blocking probability with zero-crosstalk constraint for a network as large as 4096 × 4096 at full load. In this paper, first we propose the pruning of VSOB networks that reduces the hardware cost by almost 30%. The networks can still use the PFR algorithm and results in the same blocking probability. However, we show that the blocking probability can be reduced dramatically while keeping the optimum time complexity O (log N ) by allowing only a small amount of crosstalk. Then, we propose a new kind of switching networks in which extra regular banyan planes have been added with the pruned VBOS (P-VSOB) networks. Necessary routing algorithms, namely, PFR_RS and PFR_LS show that this new switching network can reduce the blocking probability to very low value even with zero-crosstalk constraint while keeping the hardware cost 3almost the same as for P-VSOB networks. Both these algorithms also have time complexity O ( N log N ).

Vertical stacking of multiple optical banyan networks is a novel scheme for building banyan-based nonblocking optical switches. The resulting network, namely vertically stacked optical banyan (VSOB) network, preserves the properties of small depth and absolutely loss uniformity but loses the nice self-routing capability of banyan networks. To guarantee a high switching speed, routing in VSOB network needs special attentions so that paths can be established as fast as possible. The best known global routing algorithm for an N × N nonblocking VSOB network has the time complexity of O(Nlog N), which will introduce an unacceptable long delay in path establishment for a large size optical switch. In this paper, we propose two fast routing algorithms for the VSOB network based on the idea of inputs grouping. The two algorithms, namely plane fixed routing (PFR) algorithm and partially random routing (PRR) algorithm, have the time complexities of O(log N) and O$(\sqrt{N})$ respectively, and FR algorithm can actually turn a VSOB network into a self-routing one. Extensive simulation based on a network simulator indicates that for large VSOB networks our new algorithms can achieve a reasonably low blocking probability while guarantee a very high switching speed.

Banyan networks are attractive for constructing directional coupler (DC)-based optical switching networks for their small depth and self-routing capability. Crosstalk between optical signals passing through the same DC is an intrinsic drawback in DC-based optical networks. Vertical stacking of multiple copies of an optical banyan network is a novel scheme for building nonblocking (crosstalk-free) optical switching networks. The resulting network, namely vertically stacked optical banyan (VSOB) network, preserves all the properties of the banyan network, but increases the hardware cost significantly. Though much work has been done for determining the minimum number of stacked copies (planes) required for a nonblocking VSOB network, little is known on analyzing the blocking probabilities of VSOB networks that do not meet the nonblocking condition (i.e., with fewer stacked copies than required by the nonblocking condition). In this paper, we analyze the blocking probabilities of VSOB networks and develop their upper and lower bounds with respect to the number of planes in the networks. These bounds depict accurately the overall blocking behaviors of VSOB networks and agree with the conditions of strictly nonblocking and rearrangeably nonblocking VSOB networks respectively. Extensive simulation on a network simulator with both random routing and packing strategy has shown that the blocking probabilities of both strategies fall nicely within our bounds, and the blocking probability of packing strategy actually matches the lower bound. The proposed bounds are significant because they reveal the inherent relationships between blocking probability and network hardware cost in terms of the number of planes, and provide network developers a quantitative guidance to trade blocking probability for hardware cost. In particular, our bounds provide network designers an effective tool to estimate the minimum and maximum blocking probabilities of VSOB networks in which different routing strategies may be applied. An interesting conclusion drawn from our work that has practical applications is that the hardware cost of a VSOB network can be reduced dramatically if a predictable and almost negligible nonzero blocking probability is allowed.

Vertical stacking is a novel alternative for constructing nonblocking multistage interconnection networks (MINs). Rearrangeably nonblocking optical MINs are attractive since they have lower complexity than their strictly nonblocking counterparts. In this paper, we study the realization of crosstalk-free permutations in rearrangeably nonblocking, self-routing banyan-type optical MINs built on vertical stacking. An available scheme for realizing crosstalk-free permutation in this type of optical MINs requires to first decompose a permutation into multiple crosstalk-free partial permutations based on the Euler-Split technique, and then to realize them crosstalk-free in different planes (stacked copies) of the MIN simultaneously. The overall time complexity of this scheme to realize a crosstalk-free permutation in an N × N optical MIN is O(N log N) which is dominated by the complexity of crosstalk-free decomposition. In this paper, we propose a new scheme for realizing permutations in this class of vertically stacked optical MINs crosstalk-free. The basic idea of the new scheme is to classify permutations into permutation classes such that all permutations in one class share the same crosstalk-free decomposition pattern. By running the Euler-Split based crosstalk-free decomposition only once for a permutation class and applying the obtained crosstalk-free decomposition pattern to all permutations in the class, crosstalk-free decomposition of permutations can be realized in a more efficient way. We show that the number of permutations in a permutation class is huge (√N!)√N when log2N is even and (√2N!)√N/2 when log2N is odd), and thus the average time complexity of crosstalk-free decomposition of a permutation becomes O(N).

With the current technology, all-optical networks require nonblocking switch architectures for building optical cross-connects. The crossbar switch has been widely used for building an optical cross-connect due to its simple routing algorithm and short path setup time. It is known that the crossbar suffers from huge signal loss and crosstalk. The Clos network uses a crossbar as building block and reduces switch complexity, but it does not significantly reduce signal loss and crosstalk. Although the Spanke's network eliminates the crosstalk problem, it increases the number of switching elements required considerably (to 2N 2 - 2N). In this paper, we propose a new architecture for building nonblocking optical switching networks that has much lower signal loss and crosstalk than the crossbar without increasing switch complexity. Using this architecture we can build non-squared nonblocking networks that can be used as building block for the Clos network. The resulting Clos network will then have not only lower signal loss and crosstalk but also a lower switch complexity.

During the path establishment, states of switching elements in the switch network may need rearrangement. C.-T. Lea et. al [1] has first mentioned about the rearrangement behavior of the switching networks. He has analyzed the frequency of its occurrence using stochastic method. It is notable that rearrangement behavior of switching network includes rearrangement of connections and rearrangement of switching elements. Optimization of rearrangement cost of switching network can save both power and time, which in turn can increase the switching speed. This paper determines the rearrangement cost of strictly non-blocking Vertically Stacked Optical Banyan networks in terms of switching elements. We believe that our result will be helpful in designing, implementing and analyzing different algorithms of the networks.

Optical banyan networks can be made rearrangeably nonblocking using its multiple copies in unison. Such rearrangeably nonblocking networks are known as vertically stacked optical banyan (VSOB) networks. Centralized control routing algorithm for this rearrangeably nonblocking optical banyan networks has time complexity O ( N log2 N ). A distributed control routing algorithm with time complexity O (log2 N ) has been proposed recently in which authors have considered N completely connected processors to take routing decision which practically would be very difficult to implement for large N . In this paper we propose two distributed control routing algorithms where processors are loosely connected. In the first algorithm ) ( N O processors work in pipelined fashion, and take the routing decision in linear time. In the second algorithm N inputs synchronously hunt for a free route among ) ( N O copies of a banyan network using a look up table. This algorithm has time complexity ) ( N O . Also the processors do not need to be completely connected, which makes it more practical for implementation.

Due to its nice properties of small depth and absolute signal loss uniformity, vertical stacking of optical banyan (VSOB) networks becomes an attractive optical switch architecture. It is expected that a VSOB switch will have a good fault-tolerant capability, because it consists of multiple banyan networks. To verify our expectation, in this paper we study the overall blocking behavior of a VSOB switch by establishing an upper bound on its blocking probability in presence of link failures. The upper bound accurately depicts the overall blocking behavior of a VSOB switch for a reasonable small link failure rate, as verified by extensive simulation results. Although our upper bound demonstrates that VSOB switches have a good fault-tolerance property, it reveals a surprising overall blocking behavior of a faulty VSOB switch that, not as we usually expected, the blocking probability of the switch may not always increase monotonously with the increase of link failure rate. Our upper bound is significant, because it provides switch designers a quantitative tool to determine the effects of link failure on the blocking behavior and to estimate the maximum blocking probability of a VSOB switch, in which different routing algorithms can be applied with a guaranteed performance in terms of blocking probability and hardware cost.

Vertical stacking is a novel scheme in creating nonblocking multistage interconnection networks (MINs). Available results indicate that under the crosstalk-free constraint, the hardware cost is high for a strictly nonblocking optical MIN based on the scheme. Packing strategy is a commonly used routing strategy for reducing network hardware. In this paper, we look into the nonblocking conditions for crosstalk-free optical MINs under packing strategy. It is shown that packing strategy is very efficient in reducing the hardware cost of a nonblocking optical MIN under the crosstalk-free constraint. The results in the paper will be useful in designing optical MINs.