Abstract-In this paper, we propose a new approach to generate quadrupling-frequency optical millimeter-wave (mm-wave) signal with carrier suppression by using two parallel Mach-Zehnder modulators (MZMs) in Radio-over-fiber (RoF) system. Among the numerous properties of this approach, the most important is that a filterless optical mm-wave at 60 GHz with an optical sideband suppression ratio (OSSR) as high as 40 dB can be obtained when the extinction ratio of the MZM is 25 dB. Simplicity and cost-effectiveness have made this approach a compelling candidate for future wave-division-multiplexing RoF systems.Theoretical analysis is conducted to suppress the undesired optical sidebands for the high-quality generation of frequency quadrupling mm-wave signal. The simulation results show that a 60 GHz mm-wave is generated from a 15 GHz radio frequency (RF) oscillator with an OSSR as high as 40 dB and an radio frequency spurious suppression ratio (RFSSR) exceeding 35 dB without any optical or electrical filter when the extinction ratio of the MZM is 25 dB. Furthermore, the effect of the non-ideal RF-driven voltage as well as the phase difference of RF-driven signals applied to the two MZMs on OSSR and RFSSR is discussed and analyzed. Finally, we establish a RoF system through simulation to verify the transmission performance of the proposed scheme. The Q-factor performance and eye patterns are given.
Context The interpretations of cardiotocography (CTG) tracings are indeed vital to monitor fetal well-being both during pregnancy and childbirth. Currently, many studies are focusing on feature extraction and CTG classification using computer vision approach in determining the most accurate diagnosis as well as monitoring the fetal well-being during pregnancy. Additionally, a fetal monitoring system would be able to perform detection and precise quantification of fetal heart rate patterns. Objective This study aimed to perform a systematic review to describe the achievements made by the researchers, summarizing findings that have been found by previous researchers in feature extraction and CTG classification, to determine criteria and evaluation methods to the taxonomies of the proposed literature in the CTG field and to distinguish aspects from relevant research in the field of CTG. Methods Article search was done systematically using three databases: IEEE Xplore digital library, Science Direct, and Web of Science over a period of 5 years. The literature in the medical sciences and engineering was included in the search selection to provide a broader understanding for researchers. Results After screening 372 articles, and based on our protocol of exclusion and inclusion criteria, for the final set of articles, 50 articles were obtained. The research literature taxonomy was divided into four stages. The first stage discussed the proposed method which presented steps and algorithms in the pre-processing stage, feature extraction and classification as well as their use in CTG (20/50 papers). The second stage included the development of a system specifically on automatic feature extraction and CTG classification (7/50 papers). The third stage consisted of reviews and survey articles on automatic feature extraction and CTG classification (3/50 papers). The last stage discussed evaluation and comparative studies to determine the best method for extracting and classifying features with comparisons based on a set of criteria (20/50 articles). Discussion This study focused more on literature compared to techniques or methods. Also, this study conducts research and identification of various types of datasets used in surveys from publicly available, private, and commercial datasets. To analyze the results, researchers evaluated independent datasets using different techniques. Conclusions This systematic review contributes to understand and have insight into the relevant research in the field of CTG by surveying and classifying pertinent research efforts. This review will help to address the current research opportunities, problems and challenges, motivations, recommendations related to feature extraction and CTG classification, as well as the measurement of various performance and various data sets used by other researchers.
Context: Quality Control (QC) has been constantly an essential concern in many fields like food industry production, medical drugs, environmental protection, and so on. An odor or flavor, as a global fingerprint, can be implemented as a non-invasive mechanism for quality assurance. This computer-based approach can assure accurate detection and precise identification of the product quality or manufactured goods.Objective: This paper aims to achieve a systematic review about e-nose by introducing the achievements made by researchers in this area, to summarize their findings, to provide motivations and challenges to new researchers in the field of e-nose. Methods:The articles that were being utilized in the e-nose field were systematically achieved using three search engines: The online library of IEEE Explore, Web of Science and Science Direct for time span of 7 years (from 2013 to 2020). Both medical literature reviews and technical reviews were considered in the criteria of the research for wider understanding in the field of e-nose. The articles were categorized according to the objective of the research and projected into four classes. Upon completion of screening process 333 research papers using the exclusion and inclusion conditions, as the final set 54 articles were selected. Results:The taxonomy of this research was classified into four categories. The first one included the suggested methods that introduced the utilization of the e-nose for classification purposes (9/54 papers). The second category comprises the methods related to the development of e-nose (24/54 papers). The third one included the review studies about the e-nose (8/54 papers). The fourth group comprises comparative studies and evaluation (13/54 papers).Discussion: This systematic review contributes for a clearer understanding and a full insight in the e-nose research field by surveying and categorizing pertinent research efforts.
Home and building security are major concern in our daily life and digital smart door lock (DSDL) have become an essential part of these systems. In this paper, a secure DSDL which can grant access to home with a fingerprint is designed and implemented. An Arduino Nano microcontroller board, finger print sensor and servo motor have been utilized for lock/unlock door based on finger print. The DSDL is an automatic authenticate and validate the user for secure access. The implemented system aims to develop a cost−effective DSDL based on low−cost components compared to the systems already on the domestic market. The−ease of−use and cost−effectiveness makes the DSDL a strong competitor to the digital security system on the domestic market and outperforms it and suitable for security–based home automation systems.
<span>Fifth−generation (5G) wireless networks that use the MM−W hold a great promise to revolutionize wireless industry. However, the difficulty in generating and transmitting these high‐frequency signals in the electrical−domain due to bandwidth limitation of electronic components, and high absorption loss limits current applications. Consequently, optical generation and transmission of MM−W signals are a viable option. In this paper, a comparative study is carried out on three electro−optical upconversion (EOU) techniques to generate 60−GHz MM−W signal, namely 4−tupling, 6−tupling and 8−tupling. The paper briefly describes the three techniques and analyses the optical harmonic distortion suppression ratio (OHDSR) and electrical spurious suppression ratio (ESSR) generated by each one of the techniques. OHDSR and ESSR have been compared to show the trade-off between the techniques. In addition, the paper compares the implementation of non−ideal phase shifting on OHDSR for the three EOU techniques Finally, the performance of the three EOU techniques after transmission over optical fiber is evaluated by quality factor (Q−factor) and eye pattern test. The results of the simulation illustrate well the benefits of the performed study and confirm that the 4−tupling constitutes a cost−effective technique to generate MM−W signals.</span>
Abstract-In this paper, we present a cost effective method to generate a high-quality quadruple frequency optical millimeterwave (MMW) signal using an integrated dual-parallel Mach-Zehnder modulator (IDP-MZM). Not only does the method minimize the complication of the central station (CS) and its frequency demand for the devices, but the generated optical MMW signal as well has good transmission performance. By properly adjusting the direct current (DC) bias, modulation index, and using two radio frequency (RF) driving signals with 135 • phase delay, a high quality dual tone optical MMW at 60 GHz is generated from a 15 GHz RF local oscillator (LO) with optical sideband suppression ratio (OSSR) as high as 32 dB and radio frequency spurious suppression ratio (RFSSR) exceeding 33 dB without optical filter when an IDP-MZM with 30 dB extinction ratio is utilized. Furthermore, the influences of a number of non-ideal parameters, such as imperfect extinction ratio, non-ideal RF driven voltage, and phase difference of RF-driven signals applied to two subMZMs of the IDP-MZM, on OSSR are studied through simulation. Finally, we build a Radio over Fiber system through simulation, and the transmission performance of the generated optical MMW signal is
Fifth−generation (5G) and millimeter−waves (MM−W) hold tremendous promise to provide opportunities torevolutionize education, healthcare, business, and agriculture.Nevertheless, the generation of MM−W in the electrical−domain is infeasible due to the bandwidth limitation of electronic componentsand radio frequency (RF) interference. The capability to generate MM−W in the optical−domain can provide transportation ofMM−W with low loss from switching center to remote base stations. The present paper is focusing on electro−opticalup−conversion (EOU) techniques for optical generation and transmission of 60−GHz MM−W signal. A comparative study iscarried out between three different EOU techniques: frequency−quadrupling, frequency sextupling and frequency−octotupling. The comparative study aims at showing the strengths and weaknesses of three EOU techniques and evaluatingeach technique in terms of electrical spurious suppression ratio (ESSR), as well as in terms of the influence of non−ideal phaseshifting. The performance of the three EOU techniques after transmission over optical fiber is evaluated by eye pattern test. Theresults of the simulation confirm that the frequency−quadrupling outperforms frequency− sextupling and frequency− octotuplingtechniques.
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