9,578 results
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2. The Physical Mechanism of Frequency-Induced Inflection Point for Oil–Paper Insulation Under High-Frequency Square-Wave Voltage.
- Author
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Liu, Kai, Li, Xiaonan, Yang, Yan, Wu, Zihao, Liu, Tong, Zhu, Minghui, and Wu, Guangning
- Subjects
- *
SQUARE waves , *PARTIAL discharges , *VOLTAGE , *INFLECTION (Grammar) , *DECAY constants , *SURFACE charges , *SILICONE rubber - Abstract
High-frequency (HF) oil-immersed transformers with small size and light weight have been paid wide attention by researchers. Its oil–paper insulation frequently withstands HF over-voltages at frequencies of several kilohertz and above, resulting in the too early failure of oil–paper insulation. In order to investigate the effect of HF on oil–paper insulation, this article investigates the partial discharge (PD) characteristics of oil–paper insulation under HF stress. The experimental results show that a frequency-induced inflection point is existed near 10 kHz and the PD parameters of HF voltages is much higher than that ac voltages. Besides, the theoretical mechanism is expounded to interpret and understand the formation process of frequency-induced inflection points more easily. It can be found that the change in frequency causes the change in the charge decay time constant and the residual charge on the insulating surface, resulting in the formation of the frequency-induced inflection point at HF. These results might contribute to determine the characteristics of PDs between HF voltages and ac voltages. It can provide references for the research and production of HF transformers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. Integrated Control-Fluidic Codesign Methodology for Paper-Based Digital Microfluidic Biochips.
- Author
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Wang, Qin, Schlichtmann, Ulf, Cai, Yici, Ji, Weiqing, Li, Zeyan, Cheong, Haena, Kwon, Oh-Sun, Yao, Hailong, Ho, Tsung-Yi, Shin, Kwanwoo, and Li, Bing
- Subjects
- *
BIOCHIPS , *CONDUCTIVE ink , *CARBON nanotubes , *VOLTAGE control , *INK-jet printers , *FLUIDIC devices - Abstract
Paper-based digital microfluidic biochips (P-DMFBs) have recently emerged as a promising low-cost and fast-responsive platform for biochemical assays. In P-DMFBs, electrodes and control lines are printed on a piece of photograph paper using an inkjet printer and carbon nanotubes (CNTs) conductive ink. Compared with traditional digital microfluidic biochips (DMFBs), P-DMFBs enjoy significant advantages, such as faster in-place fabrication with printer and ink, lower costs, and better disposability. Since electrodes and CNT control lines are printed on the same side of this paper, a critical design challenge for P-DMFB is to prevent control interference between moving droplets and the voltages on CNT control lines. Control interference may result in unexpected droplet movements and thus incorrect assay outputs. To address this design challenge, a control-fluidic codesign methodology is proposed in this paper, along with two demonstrative design flows integrating both fluidic design and control design, i.e., the droplet-oriented codesign flow and the electrode-oriented codesign flow. The droplet-oriented flow is suitable for designing biochips with sparse electrodes and relatively larger number of droplets, whereas the electrode-oriented flow is suitable for biochips with dense electrodes and smaller number of droplets. The computational simulation results of real-life bioassays demonstrate the effectiveness of the proposed codesign flows. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
4. Grammatical interference in written papers translated by Russian and American students.
- Author
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Galkina, Alexandra and Radyuk, Alexandra V.
- Subjects
- *
TRADITIONAL knowledge , *NATIVE language , *INTERFERENCE (Linguistics) , *FOREIGN language education , *LANGUAGE & languages - Abstract
Language interference is one of the most common problems in foreign language teaching. Language learners inevitably apply knowledge of their native language to a second language, which leads to linguistic interference. The more differences there are between the two languages, the more prominent the interference between them will be. This paper examines the key issues faced by Russian students learning English and English-speaking students learning Russian and suggests key areas of teaching needed in both disciplines. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Schiff Base Modified Paper Test Strips for Naked Eye Detection of Copper Ions in Mixed Aqueous Media.
- Author
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Sidana, Nancy, Kaur, Harminder, and Devi, Pooja
- Abstract
A multi responsive Schiff base sensor L with thiophenol moiety was synthesized by the single-step condensation method. The structural analysis of the sensor was proposed by 1H-NMR, UV- Visible absorption, HRMS and FT-IR spectroscopy. Sensor L exhibited an instant appearance of yellow color on the addition of copper ions. Since copper gave an intense color change, therefore detailed studies were performed for copper sensing w.r.t. designed sensor L. Selectivity and sensitivity of sensor concerning copper metal ions were established by performing various UV-Visible spectroscopic and colorimetric studies. The 1:1 binding framework of the L-Cu2+ complex is confirmed by Job’s Plot and further supported by DFT studies. With the help of Benesi-Hildebrand equation, the detection limit and the association constants were found to be $3.15 \times 10^{-6}$ M and $1.16 \times 10^{4}$ M−1, respectively. In addition, sensor L was transferred onto solid substrates including silica and paper strips for establishing its utility in the onsite detection of copper ions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Dirty-Paper Coding Based Secure Transmission for Multiuser Downlink in Cellular Communication Systems.
- Author
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Wang, Bo and Mu, Pengcheng
- Subjects
- *
MULTIUSER channels , *LINEAR network coding , *WIRELESS communications , *BROADCAST channels , *COVARIANCE matrices , *PROBABILITY theory - Abstract
This paper studies the secure transmission in a multiuser broadcast channel where only the statistical channel state information of the eavesdropper is available. We propose to apply secret dirty-paper coding (S-DPC) in this scenario to support the secure transmission of one user and the normal (unclassified) transmission of the other users. By adopting the S-DPC and encoding the secret message in the first place, all the information-bearing signals of the normal transmission are treated as noise by potential eavesdroppers and thus provide secrecy for the secure transmission. In this way, the proposed approach exploits the intrinsic secrecy of multiuser broadcasting and can serve as an energy-efficient alternative to the traditional artificial noise (AN) scheme. To evaluate the secrecy performance of this approach and compare it with the AN scheme, we propose two S-DPC-based secure transmission schemes for maximizing the secrecy rate under constraints on the secrecy outage probability (SOP) and the normal transmission rates. The first scheme directly optimizes the covariance matrices of the transmit signals, and a novel approximation of the intractable SOP constraint is derived to facilitate the optimization. The second scheme combines zero-forcing dirty-paper coding and AN, and the optimization involves only power allocation. We establish efficient numerical algorithms to solve the optimization problems for both schemes. Theoretical and simulation results confirm that, in addition to supporting the normal transmission, the achievable secrecy rates of the proposed schemes can be close to that of the traditional AN scheme, which supports only the secure transmission of one user. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
7. Practical Dirty Paper Coding With Sum Codes.
- Author
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Rege, Kiran M., Balachandran, Krishna, Kang, Joseph H., and Kemal Karakayali, M.
- Subjects
- *
CHANNEL coding , *SIGNAL quantization , *CONSTELLATION diagrams (Signal processing) , *DECODING algorithms , *INTERFERENCE (Telecommunication) - Abstract
In this paper, we present a practical method to construct dirty paper coding (DPC) schemes using sum codes. Unlike the commonly used approach to DPC where the coding scheme involves concatenation of a channel code and a quantization code, the proposed method embodies a unified approach that emulates the binning method used in the proof of the DPC result. Auxiliary bits are used to create the desired number of code vectors in each bin. Sum codes are obtained when information sequences augmented with auxiliary bits are encoded using linear block codes. Sum-code-based DPC schemes can be implemented using any linear block code, and entail a relatively small increase in decoder complexity when compared to standard communication schemes. They can also lead to significant reduction in transmit power in comparison to standard schemes. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
8. Tool workspace consideration for assembly plan generation
- Author
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Bedeoui, Akram, Ben Hadj, Riadh, Hammadi, Moncef, and Aifaoui, Nizar
- Published
- 2021
- Full Text
- View/download PDF
9. Highly Selective Electrochemical Sensing of Dopamine, Xanthine, Ascorbic Acid and Uric Acid Using a Carbon Fiber Paper.
- Author
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Mohan, Jaligam Murali, Amreen, Khairunnisa, Javed, Arshad, Dubey, Satish Kumar, and Goel, Sanket
- Abstract
Biological compounds like Dopamine (D), Xanthine (X), Ascorbic acid (AA) and Uric acid (UA) play a vital role in food, clinical and human metabolism. Since these compounds are present in biological fluids and have close standard potentials values, it is imperative to choose a method to sense these fluids without any electrochemical interference. Toray paper, with a porous gas diffusion layer imbibed with denser carbon fibers, is an excellent option that can be utilized as a working electrode for such sensing applications. Herein, the electroactivity of these compounds was tested using cyclic voltammetry and square wave voltammetry without any interference. The linear ranges for the compounds (D, X, AA, UA) are 10- $1000~\mu \text{M}$ , 7- $300~\mu \text{M}$ , 100- $1000~\mu \text{M}$ and 30- $1000~\mu \text{M}$ respectively, while the limits of detection are $9.67~\mu \text{M}$ , $6.54~\mu \text{M}$ , $97.12~\mu \text{M}$ and $28.74~\mu \text{M}$ respectively with S/N ratio of 1.5. Finally, the electrode was tested with human serum samples for the identification of D, X, AA and UA manifesting exceptional reproducibility. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. An improved peak side lobe reduction method for linear array antenna for military applications
- Author
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D, Ravi Tej, K, Sri Kavya Ch, and Kotamraju, Sarat K.
- Published
- 2021
- Full Text
- View/download PDF
11. Channel Capacity Analysis for Dirty Paper Coding With the Binary Codeword and Interference.
- Author
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Xu, Zhengguang and Xie, Yongbiao
- Abstract
Dirty paper coding is an interference pre-cancellation method for known interference at the transmitter and serves as a basic building block in the digital watermarking system. In this letter, we investigate the dirty paper model in the simplest digital communication system, where both the codeword and the interference are binary. For watermark embedment, we derive the relevant coding, the constant coding, and the symmetric relevant coding when the encoder focuses on the binary codeword and interference. The channel capacity is analyzed and the optimal parameter is discussed in the case. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
12. Optimal Sum Rate-Fairness Tradeoff for MIMO Downlink Communications Employing Successive Zero Forcing Dirty Paper Coding.
- Author
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Lu, Hsiao-Feng
- Abstract
New power allocation schemes taking both sum-rate and fairness into account for MIMO downlink communications employing successive zero-forcing dirty paper coding are presented in this letter. Specifically, using a revised l
1 -norm fairness measure that allows for a more comprehensive consideration when users have an unequal number of receive antennas, the optimal tradeoff between sum-rate and fairness for MIMO downlink communications with arbitrary channel statistics is completely characterized. A novel stochastic power allocation scheme capable of achieving this optimal tradeoff is also given. To put the optimal tradeoff into practical use, an explicit rule for selecting operating sum-rate from the tradeoff is then proposed. Simulation results show that the new scheme can yield higher sum-rate and better fairness at the same time. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
13. An anti-interference detection algorithm for parking monitoring systems
- Author
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Dong, Ani, Zhang, Zusheng, and Chen, Jiaming
- Published
- 2019
- Full Text
- View/download PDF
14. Experimental study on the relationship between the friction coefficient and interference in locomotive axle press-fitting
- Author
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Wang, Ting, Guo, Hanfei, Qiao, Jianjun, Liu, Xiaoxue, and Fan, Zhixin
- Published
- 2021
- Full Text
- View/download PDF
15. Unraveling the Mistakes: An Analysis of Student Errors in Translating Literary Texts.
- Author
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Rexhepi, Sadije, Blakaj-Gashi, Albulena, and Haklaj, Agnesa
- Subjects
LITERARY errors & blunders ,NATIVE language ,GERMAN language ,LANGUAGE & languages ,ORTHOGRAPHY & spelling - Abstract
The aim of this paper is to analyse the translation performance of German students at the University of Prishtina when translating literary texts from German into Albanian. The paper focuses on the question of whether errors occur during the translation process in the areas of grammar, orthography, semantics, and sentence structure, including possible interference errors between the two languages. These errors may arise due to uncertainties, carelessness, or the influence of other languages. The interference of German manifests itself primarily in the lexical level and sentence structure. If the languages have differences in sentence structure, this interference leads to grammatically incorrect sentences. An interference of Albanian is also noticeable, primarily on a pragmatic level, which is mainly determined by the cultural context. Errors are a characteristic feature of foreign language learners. They are a phenomenon that affects not only foreign language learners but also native speakers. This paper analyses and classifies the errors that German students at the University of Prishtina make when translating by applying the theoretical, analytical, and contrastive methods in the translation of literary texts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Multi-core interference over-estimation reduction by static scheduling of multi-phase tasks
- Author
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Meunier, Rémi, Carle, Thomas, and Monteil, Thierry
- Published
- 2024
- Full Text
- View/download PDF
17. Han–Kobayashi and Dirty-Paper Coding for Superchannel Optical Communications.
- Author
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Koike-Akino, Toshiaki, Kojima, Keisuke, Millar, David S., Parsons, Kieran, Kametani, Soichiro, Sugihara, Takashi, Yoshida, Tsuyoshi, Ishida, Kazuyuki, Miyata, Yoshikuni, Matsumoto, Wataru, and Mizuochi, Takashi
- Abstract
Superchannel transmission is a candidate to realize Tb/s-class high-speed optical communications. In order to achieve higher spectrum efficiency, the channel spacing shall be as narrow as possible. However, densely allocated channels can cause non-negligible inter-channel interference (ICI) especially when the channel spacing is close to or below the Nyquist bandwidth. In this paper, we consider joint decoding to cancel the ICI in dense superchannel transmission. To further improve the spectrum efficiency, we propose the use of Han–Kobayashi superposition coding. In addition, for the case when neighboring subchannel transmitters can share data, we introduce dirty-paper coding for pre-cancelation of the ICI. We analytically evaluate the potential gains of these methods when ICI is present for sub-Nyquist channel spacing. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
18. INTERFERENCJE LEKSYKALNE W WYPOWIEDZIACH PISEMNYCH SŁOWIAN ZE WSCHODU (NA PODSTAWIE PISEMNYCH PRAC CERTYFIKATOWYCH Z ROKU 2019, POZIOM B1).
- Author
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Przechodzka, Grażyna and Hudy, Wiktorija
- Subjects
POLISH language ,LANGUAGE & languages ,TASKS ,AUTHORS - Abstract
Copyright of Acta Universitatis Lodziensis: Kształcenie Polonistyczne Cudzoziemców is the property of Wydawnictwo Uniwersytetu Lodzkiego and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
- Full Text
- View/download PDF
19. Invited paper: Characterization of few mode fibers and devices.
- Author
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Grüner-Nielsen, Lars, Mathew, Neethu Mariam, and Rottwitt, Karsten
- Subjects
- *
SPECTRAL imaging , *FIBERS , *INFORMATION measurement , *OPTICAL measurements , *OPTICAL fibers - Abstract
• Review of characterization techniques for few mode fibers and components. • Focus is on interferometric methods. • Simple interferometric setup for measuring mode coupling and DGD. • Improved algorithm for spatial and spectral resolved imaging for the two modes. • Effect of the rotation of asymmetric modes. This paper reviews characterization techniques for few mode fibers and components. The focus is on interferometric techniques including spatial and spectral resolved imaging (S2). Simple interferometric measurements are shown to be able to give quite comprehensive information including measurement of relative group delay. A new improved algorithm for analyzing S2 data for the case of only two modes is presented. The effect of polarization and rotation of asymmetric modes is treated as well. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
20. A Generalized Zero-Forcing Precoder With Successive Dirty-Paper Coding in MISO Broadcast Channels.
- Author
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Hu, Sha and Rusek, Fredrik
- Abstract
In this paper, we consider precoder designs for multiuser multiple-input-single-output broadcasting channels. Instead of using a traditional linear zero-forcing (ZF) precoder, we propose a generalized ZF (GZF) precoder in conjunction with successive dirty-paper coding (DPC) for data transmissions, namely, the GZF-DP precoder, where the suffix “DP” stands for “dirty-paper.” The GZF-DP precoder is designed to generate a band-shaped and lower triangular effective channel F , such that only the entries along the main diagonal and the $\nu $ first lower-diagonals can take non-zero values. Utilizing the successive DPC, the known non-causal inter-user interferences from the other (up to) $\nu $ users are canceled through successive encoding. We analyze optimal GZF-DP precoder designs both for sum-rate and minimum user-rate maximizations. Utilizing Lagrange multipliers, the optimal precoders for both cases are solved in closed-forms in relation to optimal power allocations. For the sum-rate maximization, the optimal power allocation can be found through water filling, but with modified water levels depending on the parameter $\nu $ , while for the minimum user-rate maximization that measures the quality of the service, the optimal power allocation is directly solved in closed-form, which also depends on $\nu $ . Moreover, we propose two low-complexity user-ordering algorithms for the GZF-DP precoder designs for both maximizations, respectively. We show, through numerical results, that the proposed GZF-DP precoder with a small $\nu $ value (≤ 3) renders significant rate increments compared with the previous precoder designs, such as the linear ZF and the user-grouping-based DPC precoders. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
21. Multi-dimensional signals coupling of simultaneous acquisition stripping current with laser-induced breakdown spectroscopy for accurate analysis of Cd(II) in coexisting Cu(II).
- Author
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Yang, Yuan-Fan, Song, Zong-Yin, Liu, Zi-Hao, Gao, Zhi-Wei, Cai, Xin, Huang, Cong-Cong, Dai, Pang-Da, Yang, Meng, Li, Pei-Hua, Chen, Shi-Hua, and Huang, Xing-Jiu
- Subjects
- *
LASER-induced breakdown spectroscopy , *COPPER , *SUBSTITUTION reactions , *CARBON paper , *CARBON electrodes - Abstract
Despite significant advancements in detecting Cd(II) using nanomaterials-modified sensitive interfaces, most detection methods rely solely on a single electrochemical stripping current to indicate concentration. This approach often overlooks potential inaccuracies caused by interference from coexisting ions. Therefore, establishing multi-dimensional signals that accurately reflect Cd(II) concentration in solution is crucial. In this study, we developed a system integrating concentration, electrochemical stripping current, and laser-induced breakdown spectroscopy (LIBS) characteristic peak intensity through in-situ laser-induced breakdown spectroscopy and electrochemical integrated devices. By simultaneously acquiring multi-dimensional signals to dynamically track the electrochemical deposition and stripping processes, we observed that replacement reactions occur between Cu(II) and Cd(II) on the surface of Ru-doped MoS 2 modified carbon paper electrodes (Ru-MoS 2 /CP). These reactions facilitate the oxidation of Cd(0) to Cd(II) during the stripping process, significantly increasing the currents of Cd(II). Remarkably, the ingenious design of the Ru-MoS 2 sensitive interface allowed for the undisturbed deposition of Cu(II) and Cd(II) during the electrochemical deposition process. Consequently, our in-situ integrated device achieved accurate detection of Cd(II) in complex environments, boasting a detection sensitivity of 8606.5 counts μM⁻1. By coupling multi-dimensional signals from stripping current and LIBS spectra, we revealed the interference process between Cu(II) and Cd(II), providing valuable insights for accurate electrochemical analysis of heavy metal ions in complex water environments. [Display omitted] • Multi-dimensional signals including concentration, stripping current, and laser-induced breakdown spectroscopy. • Multi-dimensional signals collected simultaneously enable dynamic track of deposition and stripping processes. • Replacement reactions occur between Cu(II) and Cd(II) on the surface of Ru doped MoS 2 modified carbon paper electrodes. • Accurate detection of Cd(II) in complex environments through multi-dimensional signals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Outage performance of NOMA over shadowed faded channels in interference limited scenario.
- Author
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Thaherbasha, Shaik and Dhuli, Ravindra
- Abstract
In wireless communications networks, the non-orthogonal multiple access (NOMA) technique is different from the existing orthogonal multiple access (OMA) techniques. In NOMA, the available number of resources are more and it leads to multiple access interference. In this paper, initially we developed an analytical framework of interference for NOMA in terms of signal to interference ratio (SIR). Later, we asses the outage probability of NOMA based downlink communication system by considering the effect of interference. The outage probability of NOMA with fixed number of interferers is calculated for different channel propagation effects as Nakagami-m, Rayleigh faded channels with and without log-normal shadowing. The obtained outage probabilities with fixed number of interferers are used to calculate the outage probabilities with random number of interferers (total system outage probability) in different channel propagation effects. In this paper, we proposed a novel algorithm to calculate the total system outage probability for NOMA in different channel propagation effects by choosing different offered load in terms of Erlangs per cell. We calculate the analytical results of outage probability for two users which are at near and edge positions of the cell. The obtained analytical results are supported with simulated NOMA. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Practical Dirty Paper Coding Schemes Using One Error Correction Code With Syndrome.
- Author
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Kim, Taehyun, Kwon, Kyunghoon, and Heo, Jun
- Abstract
Dirty paper coding (DPC) offers an information-theoretic result for pre-cancellation of known interference at the transmitter. In this letter, we propose practical DPC schemes that use only one error correction code. Our designs focus on practical use from the viewpoint of complexity. For fair comparison with previous schemes, we compute the complexity of proposed schemes by the number of operations used. Simulation results show that compared to previous DPC schemes, the proposed schemes require lower transmission power to maintain the bit error rate to be within 10^-5 . [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
24. The Formation of 2D Holograms of a Noise Source and Bearing Estimation by a Vector Scalar Receiver in the High-Frequency Band.
- Author
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Pereselkov, Sergey, Kuz'kin, Venedikt, Ehrhardt, Matthias, Matvienko, Yurii, Tkachenko, Sergey, and Rybyanets, Pavel
- Subjects
SOUND pressure ,NOISE ,WATER depth ,ANGULAR distribution (Nuclear physics) ,HOLOGRAPHY ,EXTREME value theory ,HOLOGRAPHIC interferometry - Abstract
The holographic signal-processing method for a single vector scalar receiver (VSR) in the high-frequency band in shallow water is developed in the paper. The aim of this paper is to present the results of the theoretical analysis, numerical modeling, and experimental verification of holographic signal processing for a noise source by the VSR. The developed method is based on the formation of the 2D interferogram and 2D hologram of a noise source in a shallow-water waveguide. The 2D interferograms and 2D holograms for different channels of the VSR (P sound pressure and V X and V Y vibration velocity components) are considered. It is shown that the 2D interferogram consists of parallel interference fingers in the presence of a moving noise source. As a result, the 2D hologram contains focal points located on a straight line, and the angular distribution of the holograms has the main extreme value. It is shown in the paper that the holographic signal-processing method allows detecting the source, estimating the source bearing, and filtering the useful signal from the noise. The results of the source detection, source bearing estimation, and noise filtering are presented within the framework of experimental data processing and numerical modeling. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Development of optimal channel and power allocation through enhanced artificial ecosystem-based optimisation strategy.
- Author
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Babu, T. Sarath, Satyanarayana, Penke, and Rao, S. Nagaraja
- Subjects
ECOSYSTEMS ,EVOLUTIONARY algorithms ,RADIO networks ,INTERNET ,COGNITIVE radio - Abstract
Cognitive Radio (CR) is developed to provide effective spectrum usage. CR is much significant in improving the efficiency of the global internet in applications. The evolutionary measurement technology is utilised to improve the evaluation of channel-state information. The outcome attained very few spectrums sensing in CR for complex mobility. A good optimisation method is needed to improve the accurate channel state prediction in successful channel access. Thus, this paper aims to implement a novel power and channel allocation mechanism with the help of a new Modified Levy Flight-based Artificial Ecosystem Optimisation (MLF-AEO) Optimisation Strategy. This paper achieves the optimal power control and channel allocation mechanism intending to solve the multiple objective functions based on the constraints like Interference among users, Outage Probability, and throughput. The superiority of the proposed algorithm is thoroughly verified by various simulation results. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Multibeam and Adaptive Array Antennas: A Comparative Study.
- Author
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Beltran, Joshua Kyle D., Buenaventura, Joanna Rose V., Gilongos, Azalea G., and Arboleda, Edwin R.
- Subjects
ADAPTIVE antennas ,WIRELESS communications ,TRANSMITTING antennas ,CHANNEL estimation ,MOBILE communication systems ,ARTIFICIAL intelligence ,COMPUTATIONAL complexity - Abstract
The paper examines the application of adaptive antennas in wireless communication systems with particular attention to how well they can transmit and receive signals by dynamically adjusting radiation patterns. The review covers a range of artificial intelligence (AI) approaches that have been used to enhance adaptive antenna performance in beamforming, channel estimation, interference mitigation, and spectrum utilization. Besides adaptive antennas' potential to improve wireless communication systems, the paper also discusses their limitations, including computational complexity, interference sensitivity, and the significance of precise channel state information (CSI) estimates. [ABSTRACT FROM AUTHOR]
- Published
- 2024
27. Decentralized SINR Balancing in Cognitive Radio Networks.
- Author
-
Dhifallah, Oussama, Dahrouj, Hayssam, Al-Naffouri, Tareq Y., and Alouini, Mohamed-Slim
- Subjects
COGNITIVE radio ,RADIO transmitter-receivers ,WIRELESS communications ,SPECTRUM allocation ,OPTIMALITY theory (Linguistics) - Abstract
This paper considers the downlink of a cognitive radio (CR) network formed by multiple primary and secondary transmitters, where each multiantenna transmitter serves a preknown set of single-antenna users. This paper assumes that the secondary and primary transmitters can simultaneously transmit their data over the same frequency bands to achieve high system spectrum efficiency. This paper considers the downlink balancing problem of maximizing the minimum signal-to-interference-plus-noise ratio (SINR) of the secondary transmitters subject to both the total power constraint of the secondary transmitters and the maximum interference constraint at each primary user due to secondary transmissions. This paper proposes solving the problem using the alternating direction method of multipliers, which leads to a distributed implementation through limited information exchange across the coupled secondary transmitters. This paper additionally proposes a solution that guarantees feasibility at each iteration. Simulation results demonstrate that the proposed solution converges to the centralized solution in a reasonable number of iterations. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
28. Warunki kompatybilności systemów IMT 4G/5G z telewizją naziemną DVB-T/T2 w paśmie 700 MHz.
- Author
-
WIĘCEK, Dariusz and MORA, Marcin
- Subjects
SPECTRUM allocation ,SIGNAL separation ,ELECTROMAGNETIC compatibility ,ELECTROMAGNETIC interference ,TELECOMMUNICATION - Abstract
Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
29. Micro-displacement measurement of optical interference with two-ring conjugated vortices.
- Author
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Yu, Xiao, Li, Hongru, Zhang, Zetian, Zhang, Ru, and Wang, Sha
- Abstract
In this paper, we propose a two-ring conjugated vortex beam interferometer. The inner ring and outer ring of the vortex beams has different signs and topological charges. When combined, they produce an intricate pattern of interference fringes that resemble a flower petal, featuring both concentric inner and outer rings which rotates with different directions. We use the scale-invariant feature transformation algorithm to find the feature points. Then we use these points to measure the rotation angle of the outer ring relative to the inner ring and calculate the displacement based on it. We realize the measurement of sub-nanometer displacement. The displacement resolution is 0.38° nm
−1 . It is improved by about 12.55% compared with only the inner ring. The displacement corresponding to the minimum detectable angle of CCD is reduced from 0.080 nm to 0.060 nm. It will be a promising method in precision machining micro-vibration sensing, surface unevenness sensing, and microbial movement sensing and high-precision measurement of micro-displacement. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
30. Wireless Access in Ultra-Reliable Low-Latency Communication (URLLC).
- Author
-
Popovski, Petar, Stefanovic, Cedomir, Nielsen, Jimmy J., de Carvalho, Elisabeth, Angjelichinoski, Marko, Trillingsgaard, Kasper F., and Bana, Alexandru-Sabin
- Subjects
EXPERIMENTAL design ,WIRELESS communications ,RELIABILITY in engineering - Abstract
The future connectivity landscape, and notably, the 5G wireless systems will feature Ultra-Reliable Low Latency Communication (URLLC). The coupling of high reliability and low latency requirements in URLLC use cases makes the wireless access design very challenging, in terms of both the protocol design and of the associated transmission techniques. This paper aims to provide a broad perspective on the fundamental tradeoffs in URLLC, as well as the principles used in building access protocols. Two specific technologies are considered in the context of URLLC: massive MIMO and multi-connectivity, also termed interface diversity. This paper also touches on the importance of the proper statistical methodology for designing and assessing extremely high-reliability levels. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Interference Mitigation via Relaying.
- Author
-
Ayoughi, S. Arvin and Wei Yu
- Subjects
ANTENNAS (Electronics) ,INTERFERENCE (Telecommunication) ,SIGNAL processing ,MIMO systems ,DATA transmission systems - Abstract
This paper studies the effectiveness of relaying for interference mitigation in an interference-limited communication scenario. We are motivated by the observation that in a cellular network, a relay node placed at the cell edge observes a combination of intended signal and inter-cell interference that is correlated with the received signal at a nearby destination, so a relaying link can effectively allow the antennas at the relay and at the destination to be pooled together for both signal enhancement and interference mitigation. We model this scenario by a multiple-input multiple-output (MIMO) Gaussian relay channel with a digital relay-to-destination link of finite capacity, and with correlated noise across the relay and destination antennas. Assuming a compress-and-forward strategy with Gaussian input distribution and quantization noise, we propose a coordinate ascent algorithm for obtaining a stationary point of the non-convex joint optimization of the transmit and quantization covariance matrices. For fixed input distribution, the globally optimum quantization noise covariance matrix can be found in closed-form using a transformation for the relay’s observation that simultaneously diagonalizes two conditional covariance matrices by congruence. For fixed quantization, the globally optimum transmit covariance matrix can be found via convex optimization. This paper further shows that such an optimized achievable rate is within a constant additive gap of the MIMO relay channel capacity. The optimal structure of the quantization noise covariance enables a characterization of the slope of the achievable rate as a function of the relaying link capacity. Moreover, this paper shows that the improvement in spatial degrees of freedom by MIMO relaying in the presence of noise correlation is related to the aforementioned slope via a connection to the deterministic relay channel. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Stochastic Modeling and Analysis of User-Centric Network MIMO Systems.
- Author
-
Zhu, Caiyi and Yu, Wei
- Subjects
BEAMFORMING ,WIRELESS cooperative communication ,ANTENNAS (Electronics) ,MIMO systems ,SIGNAL processing ,WIRELESS communications - Abstract
This paper provides an analytical performance characterization of both the uplink (UL) and downlink (DL) user-centric network multiple-input multiple-output (MIMO) systems, where a cooperating base station (BS) cluster is formed for each user individually and the clusters for different users may overlap. In this model, cooperating BSs (each equipped with multiple antennas) jointly perform zero-forcing beamforming to the set of single-antenna users associated with them. As compared with a baseline network MIMO system with disjoint BS clusters, the effect of user-centric clustering is that it improves signal strength in both the UL and DL, while reducing cluster-edge interference in the DL. This paper quantifies these effects by assuming that BSs and users form Poisson point processes and by further approximating both the signal and interference powers using Gamma distributions of appropriate parameters. We show that BS cooperation provides significant gain as compared to single-cell processing for both the UL and DL, but the advantage of user-centric clustering over the baseline disjoint clustering system is significant for the DL cluster-edge users only. Although the analytic results are derived with the assumption of perfect channel state information and infinite backhaul between the cooperating BSs, they nevertheless provide architectural insight into the design of the future cooperative cellular networks. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. Adjacent-Channel Compatibility Analysis of International Mobile Telecommunications Downlink and Digital Terrestrial Television Broadcasting Reception in the 470–694 MHz Frequency Band Using Monte Carlo Simulation.
- Author
-
Taha, Hussein, Vári, Péter, and Nagy, Szilvia
- Subjects
TELEVISION broadcasting ,DIGITAL television ,TELECOMMUNICATION ,SPECTRUM allocation ,ANTENNAS (Electronics) - Abstract
This paper delves into the imperative need for coexistence and compatibility in the 470–694 MHz frequency band, as mandated by the World Radiocommunication Conference 2015 (WRC-15) and the WRC-23. It focuses on challenges in the coexistence of Digital Terrestrial Television Broadcasting (DTTB) and International Mobile Telecommunications-2020 (IMT-2020) services in downlink-only mode, particularly in adjacent-channel scenarios. Using Monte Carlo simulations, the study evaluates the probability of interference from IMT base stations with DTTB reception. The analysis thoroughly investigates the impact of the IMT transmitter's Adjacent Channel Leakage Ratio (ACLR) and the DTTB receiver's Adjacent-Channel Selectivity (ACS) on the probability of interference. The results demonstrate a significant degradation in the DTTB reception probability at the edge of coverage based on standard assumptions. To address these challenges, this paper provides recommendations for mitigating interference. These include defining enhanced ACLR regulations for IMT base stations, implementing antenna discriminations, providing specialized filters, and establishing national coordination procedures. The research provides valuable insights for informed decision making in spectrum management within the 470–694 MHz band, aiming to facilitate the coexistence of DTTB and IMT-2020 services, in line with international regulations and best practices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. IMPLICACIONES DISCURSIVAS DE LA INTERFERENCIA DEL FRANCÉS EN EL EUROLECTO JUDICIAL ESPAÑOL E ITALIANO: UN ANÁLISIS PRELIMINAR DE LA MARCACIÓN ARGUMENTATIVA BASADO EN CORPUS.
- Author
-
Pontrandolfo, Gianluca and Sarni, Chiara
- Subjects
LANGUAGE policy ,LEGAL judgments ,FRENCH language ,DISCOURSE markers ,CORPORA - Abstract
Copyright of Revista de Lingüística y Lenguas Aplicadas (RLLA) is the property of Universidat Politecnica de Valencia, Department of Applied Linguistics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
35. An All Optical Photonic Crystal Based XOR Gate for BPSK Signals.
- Author
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Nasiri, Mahsa and Andalib, Alireza
- Subjects
PHASE shift keying ,LOGIC circuits ,OPTICAL waveguides ,OPTICAL interference ,LOGIC design ,PHOTONIC crystals - Abstract
Using binary phase shift keying is one of the popular methods used for designing optical logic gates. In this paper, we used optical waveguides with different lengths for designing an all-optical XOR gate. The proposed structure works based on constructive and destructive interference of optical beams. The time delay of the proposed structure is 0.5 ps. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Improving the Sum Rate and Fairness of MIMO Downlink Communications.
- Subjects
FAIRNESS ,VIDEO coding ,RECEIVING antennas ,COVARIANCE matrices - Abstract
The aspects of sum rate and fairness for dirty paper coding (DPC) based MIMO downlink communications are investigated in this paper. We first apply the $\ell _{1}$ -norm fairness measure to formulate the problem of fairness maximization for a given sum rate as an optimization problem. The problem is unfortunately nonconvex and cannot be efficiently solved. To overcome the difficulty, we invoke the uplink-downlink duality to transform the problem back and forth between uplink and downlink communications. An efficient, iterative waterfilling based algorithm is then proposed to yield achievable rates with the best possible fairness values. Simulation results show that the proposed approach offers an enormous gain in the achievable sum rates for a wide range of fairness values, when compared to the popular successive zero-forcing DPC-based and block diagonalization based coding schemes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. Dynamic Spectrum Access for Internet-of-Things Based on Federated Deep Reinforcement Learning.
- Author
-
Li, Feng, Shen, Bowen, Guo, Jiale, Lam, Kwok-Yan, Wei, Guiyi, and Wang, Li
- Subjects
DYNAMIC spectrum access ,SMART cities ,TELECOMMUNICATION ,DEEP learning ,WIRELESS communications - Abstract
The explosive growth of Internet-of-Things (IoT) applications such as smart cities and Industry 4.0 have led to drastic increase in demand for wireless bandwidth, hence motivating the rapid development of new techniques for enhancing spectrum utilization needed by new generation wireless communication technologies. Among others, dynamic spectrum access (DSA) is one of the most widely accepted approaches. In this paper, as an enhancement of existing works, we take into consideration of inter-node collaborations in a dynamic spectrum environment. Typically, in such distributed circumstances, intelligent dynamic spectrum access almost invariably relies on self-learning to achieve dynamic spectrum access improvement. Whereas, this paper proposes a DSA scheme based on deep reinforcement learning to enhance spectrum and access efficiency. Unlike traditional Q-learning-based DSA, we introduce the following to enhance the spectrum efficiency in dynamic IoT spectrum environments. First, deep double Q-learning is adopted to perform local self-spectrum-learning for IoT terminals in order to achieve better dynamic access accuracy. Second, to accelerate learning convergence, federated learning (FL) in edge nodes is used to improve the self-learning. Third, multiple secondary users, who do not interfere with each other and have similar operation condition, are clustered for federated learning to enhance the efficiency of deep reinforcement learning. Comparing with the traditional distributed DSA with deep learning, the proposed scheme has faster access convergence speed due to the characteristic of global optimization for federated learning. Based on this, a framework of federated deep reinforcement learning (FDRL) for DSA is proposed. Furthermore, this scheme preserves privacy of IoT users in that FDRL only requires model parameters to be uploaded to edge servers. Simulations are performed to show the effectiveness of theproposed FDRL-based DSA framework. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
38. Improving Interference Analysis for Real-Time DAG Tasks Under Partitioned Scheduling.
- Author
-
Wu, Yulong, Zhang, Weizhe, Guan, Nan, and Tang, Yue
- Abstract
Real-time systems with strict timing constraints have been widely applied in many fields. The Directed acyclic graph (DAG) task model has been widely studied and applied to model real-time systems with partial parallelism and precedence constraints in each task. Our paper focuses on the worst-case response time (WCRT) analysis of DAG tasks under partitioned scheduling on multiprocessors. We investigate a parallel structure named $Str$ S t r , which helps obtain more accurate analysis results, and propose a new offline scheduling analysis algorithm named reducing repetitive calculation (RRC). Experiments with synthetic workload are conducted to compare the results calculated by RRC and the state-of-the-art, as well as the observed average response time on a real embedded system. Results show that RRC has better performance in terms of analysis accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
39. Distributed Hybrid Scheduling in Multi-Cloud Networks Using Conflict Graphs.
- Author
-
Douik, Ahmed, Dahrouj, Hayssam, Al-Naffouri, Tareq Y., and Alouini, Mohamed-Slim
- Subjects
MOBILE radio stations ,5G networks ,RADIO access networks ,LINEAR programming ,ORTHOGONAL frequency division multiplexing - Abstract
Recent studies on cloud-radio access networks assume either signal-level or scheduling-level coordination. This paper considers a hybrid coordinated scheme as a means to benefit from both policies. Consider the downlink of a multi-cloud radio access network, where each cloud is connected to several base-stations (BSs) via high capacity links and, therefore, allows for joint signal processing within the cloud transmission. Across the multiple clouds, however, only scheduling-level coordination is permitted, as low levels of backhaul communication are feasible. The frame structure of every BS is composed of various time/frequency blocks, called power-zones (PZs), which are maintained at a fixed power level. This paper addresses the problem of maximizing a network-wide utility by associating users to clouds and scheduling them to the PZs, under the practical constraints that each user is scheduled to a single cloud at most, but possibly to many BSs within the cloud, and can be served by one or more distinct PZs within the BSs’ frame. This paper solves the problem using graph theory techniques by constructing the conflict graph. The considered scheduling problem is, then, shown to be equivalent to a maximum-weight independent set problem in the constructed graph, which can be solved using efficient techniques. This paper then proposes solving the problem using both optimal and heuristic algorithms that can be implemented in a distributed fashion across the network. The proposed distributed algorithms rely on the well-chosen structure of the constructed conflict graph utilized to solve the maximum-weight independent set problem. Simulation results suggest that the proposed optimal and heuristic hybrid scheduling strategies provide appreciable gain as compared with the scheduling-level coordinated networks, with a negligible degradation to signal-level coordination. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
40. Interference Nulling Using Reconfigurable Intelligent Surface.
- Author
-
Jiang, Tao and Yu, Wei
- Subjects
SUBGRADIENT methods ,GAUSSIAN channels ,INTERFERENCE channels (Telecommunications) ,WIRELESS communications - Abstract
This paper investigates the interference nulling capability of reconfigurable intelligent surface (RIS) in a multiuser environment where multiple single-antenna transceivers communicate simultaneously in a shared spectrum. From a theoretical perspective, we show that when the channels between the RIS and the transceivers have line-of-sight and the direct paths are blocked, it is possible to adjust the phases of the RIS elements to null out all the interference completely and to achieve the maximum $K$ degrees-of-freedom (DoF) in the overall $K$ -user interference channel, provided that the number of RIS elements exceeds some finite value that depends on $K$. Algorithmically, for any fixed channel realization we formulate the interference nulling problem as a feasibility problem, and propose an alternating projection algorithm to efficiently solve the resulting nonconvex problem with local convergence guarantee. Numerical results show that the proposed alternating projection algorithm can null all the interference if the number of RIS elements is only slightly larger than a threshold of $2K(K-1)$. For the practical sum-rate maximization objective, this paper proposes to use the zero-forcing solution obtained from alternating projection as an initial point for subsequent Riemannian conjugate gradient optimization and shows that it has a significant performance advantage over random initializations. For the objective of maximizing the minimum rate, this paper proposes a subgradient projection method which is capable of achieving excellent performance at low complexity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Performance Analysis of Low Power Interference Cancellation Architecture for OFDM System.
- Author
-
Devarajan, N. Manikanda, Thenmozhi, S., Jayaram, K., and Saravanakumar, R.
- Subjects
LOGIC circuits ,ORTHOGONAL frequency division multiplexing ,TELECOMMUNICATION ,WIRELESS communications ,DATA transmission systems ,COMMUNICATION of technical information - Abstract
Orthogonal Frequency Division Multiplexing (OFDM) is a wireless communication technology that is used for highly reliable and high data rate communication. In a multi-user OFDM system, the interference has occurred in the receiver side between the consecutive OFDM symbols. This interference reduces the performance of the OFDM system. To achieve good quality in received symbols the interference level should be minimized. The conventional cancellation system requires higher interference reduction time and power. These limitations of the conventional interference cancellation architectures for OFDM systems are overcome by proposing efficient and low power interference cancellation architecture. Hence, this paper proposes a novel and efficient architecture based on logic gates for interference cancellation in multi-user OFDM systems. The proposed design consist of multiplexers, inverters and OR gate. The heuristic parameters for the proposed cancellation architecture are computed by performing an XOR operation. Compared to existing architecture, the proposed interference cancellation architecture consumes 7 mW of power consumption in the Virtex processor, 33.59 mW of power consumption in Spartan 3E processor and 0.029 mW of power consumption in the CPLD processor. This proposed interference cancellation architecture consumes fewer hardware resources and consumes low power. The proposed system is designed using Verilog High Definition Language (HDL) and synthesized in Xilinx Project Navigator 12.1i. Further, this paper also proposes gate diffusion input (GDI) based implementation of proposed interference cancellation architecture to analyse a delay and power consumption compared to other logic style implementation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. 5G interference with aviation altimeters: technology and policy recommendations for coexistence.
- Author
-
Bukhari, Janfizza and Mérida, Walter
- Subjects
- *
ALTIMETERS , *MOBILE communication systems , *TELECOMMUNICATION systems , *5G networks , *TELECOMMUNICATION - Abstract
The fifth generation (5G) cellular network roll-out provides high-speed performance, better coverage, and ubiquitous connectivity for the next-generation of intelligent communication systems. Compared to earlier versions, the new 5G wireless standard operates across a wider range of frequencies, which has raised aviation industry's concerns regarding safety and compatibility. For example, 5G systems operating with frequencies that are adjacent those used by radio altimeters could disrupt flight operations and navigation functions. This paper provides an overview of current research efforts assessing the 5G interference and its potential operational impact on altimeters. The work discusses the current stance of regulators and telecommunications operators worldwide on potential 5G interference with altimeters. The paper also compares the ongoing public consultations with key stakeholders globally regarding cellular systems' interference with altimeters. This work offers technical and policy recommendations to spectrum regulators and aviation authorities to inform the safe and efficient deployment of 5G spectra. This work identifies long-term solutions for achieving maximum 5G bands usability and ensuring compatibility among cellular technologies and aviation systems. • Aviation altimeters are highly susceptible to interference due to 5G mid-band. • Using directional 5G beams could be an interference mitigation solution. • Lack of definitive real-time data remains a barrier for interference estimation. • Regulations should be revised to reflect recent operational altimeter requirements. • Manufacturers need compliance with the altimeter's minimum operational standards. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. A new teaching-learning sequence to promote secondary school students' learning of quantum physics using Dirac notation.
- Author
-
Hennig, Fabian, Tóth, Kristóf, Förster, Moritz, and Bitzenbauer, Philipp
- Subjects
SECONDARY school students ,QUANTUM theory ,DIRAC formulation ,SECONDARY education ,CHILDREN - Abstract
This paper describes the design of a new teaching-learning sequence on quantum physics aimed at upper secondary school students. In this teaching-learning sequence, GeoGebra simulations and interactive screen experiments are used to investigate the behaviour of a single photon at beam splitter and single photon interference in a Michelson interferometer. We propose a minimal formalism using Dirac notation, which avoids complex numbers and elaborate vector calculus, to make a quantitative description of the quantum optics experiments accessible to secondary school students. With this new educational pathway, we take into account findings from physics education research, which suggest that the introduction of a mathematical formalism tailored to students' abilities might help them to overcome naive-realist views of quanta or space-time descriptions of quantum phenomena, while at the same time facilitating a transition to a functional understanding of quantum models. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Elastic-Plastic Stress Analysis of Shrink-fitted Thick FGM Cylinders Elastic-Plastic Stress Analysis of Shrink-fitted Thick FGM Cylinders.
- Author
-
Zrinej, Samiha, Laghzale, Nor-Eddine, and Bouzid, Abdel-Hakim A.
- Subjects
STRAINS & stresses (Mechanics) ,MATERIAL plasticity ,YOUNG'S modulus ,YIELD stress ,ANALYTICAL solutions - Abstract
Copyright of FME Transactions is the property of University of Belgrade, Faculty of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
45. Adaptive CAPTCHA: A CRNN-Based Text CAPTCHA Solver with Adaptive Fusion Filter Networks.
- Author
-
Wan, Xing, Johari, Juliana, and Ruslan, Fazlina Ahmat
- Subjects
ADAPTIVE filters ,CONVOLUTIONAL neural networks ,TEXT recognition ,WEBSITES - Abstract
Text-based CAPTCHAs remain the most widely adopted security scheme, which is the first barrier to securing websites. Deep learning methods, especially Convolutional Neural Networks (CNNs), are the mainstream approach for text CAPTCHA recognition and are widely used in CAPTCHA vulnerability assessment and data collection. However, verification code recognizers are mostly deployed on the CPU platform as part of a web crawler and security assessment; they are required to have both low complexity and high recognition accuracy. Due to the specifically designed anti-attack mechanisms like noise, interference, geometric deformation, twisting, rotation, and character adhesion in text CAPTCHAs, some characters are difficult to efficiently identify with high accuracy in these complex CAPTCHA images. This paper proposed a recognition model named Adaptive CAPTCHA with a CNN combined with an RNN (CRNN) module and trainable Adaptive Fusion Filtering Networks (AFFN), which effectively handle the interference and learn the correlation between characters in CAPTCHAs to enhance recognition accuracy. Experimental results on two datasets of different complexities show that, compared with the baseline model Deep CAPTCHA, the number of parameters of our proposed model is reduced by about 70%, and the recognition accuracy is improved by more than 10 percentage points in the two datasets. In addition, the proposed model has a faster training convergence speed. Compared with several of the latest models, the model proposed by the study also has better comprehensive performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Analytical and Clinical Interference of Sample Hemolysis in Evaluating Blood Biochemical and Endocrine Parameters in Cows.
- Author
-
Kovačević, Dražen, Cincović, Marko, Majkić, Mira, Spasojević, Jovan, Djoković, Radojica, Nikolić, Sandra, Došenović Marinković, Maja, Delić Vujanović, Biljana, Obradović, Nemanja, Anđušić, Ljiljana, Čukić, Aleksandar, Petrović, Miloš, Starič, Jože, and Ježek, Jožica
- Subjects
HEMOLYSIS & hemolysins ,COWS ,MASTITIS ,INFANT formulas ,LINEAR equations ,BLOOD testing ,BLOOD sampling - Abstract
Simple Summary: The metabolic profile implies simultaneous determination of carbohydrate, fat, protein, and mineral metabolism parameters as well as endocrinological parameters in the blood of cows. Blood is exposed to a variety of preanalytical factors during sampling, transport to the laboratory, and laboratory preparation for analysis, which may cause hemolysis of the sample. As hemolysis affects the values of the metabolic profile, the analyzed blood parameters may falsely increase or decrease, and the metabolic status of the cows may be misinterpreted. Preventing hemolysis is important because severe hemolysis requires discarding the sample and resampling, which is very resource-intensive. In this paper, three levels of hemolysis were determined for each blood parameter tested: (a) a hemolysis level that does not affect the values of the parameters and allows the results to be issued without restriction; (b) a hemolysis level that affects the values of the parameters but remains within the acceptable biological variability and permits the results to be issued along with a note in the form of a correction formula; and (c) a hemolysis level at which the obtained values of the parameters or the entire sample must be discarded. The results are presented graphically using interferograms, which can be easily implemented in every laboratory after validation. Hemolysis is a common cause of errors in laboratory tests as it affects blood parameters and leads to a positive or negative bias. This study aims to examine the relationship between the level of hemolysis (expressed as cell-free hemoglobin concentration, g/L) and the variability of metabolic and endocrine parameters and to determine the threshold level of hemolysis that causes an analytically and clinically significant bias for the twenty most frequently examined blood parameters in cows. Paired blood samples of 10 mL each were obtained from 30 cows. One was subjected to mechanical trauma and plasma was extracted directly from the other. Hemolyzed and non-hemolyzed samples from the same animal were mixed to obtain final samples with cell-free hemoglobin concentrations of 0, 1, 2, 4, 6, 8, and 10 g/L. Metabolic and endocrine parameters were measured in the samples and their deviation and the linear equation between the level of hemolysis and the deviation were determined. The following threshold values of hemolysis were determined, which correspond to the acceptable analytical (lower value) and clinical (upper value) levels of parameter variability: BHB 0.96 and 4.81; NEFA 0.39 and 3.31; GLU 0.38 and 3.90; ALB 1.12 and 6.11; TPROT 1.40 and 6.80; UREA 6.62 and 20.1; TBIL 0.75 and 5.65; AST 0.11 and 2.18; GGT 1.71 and 8.90, LDH 0.01 and 0.11, ALP 0.97 and 2.95; TGC 1.56 and 15.5; CHOL 1.29 and 8.56; Ca 5.68 and 25.7; P 0.57 and 8.43; Mg 1.10 and 8.47; INS 1.15 and 3.89; T3 8.19 and 15.6; T4 8.97 and 18.5; and CORT 2.78 and 11.22 g/L cell-free hemoglobin. Three decision levels are available for each metabolic and endocrine parameter: if hemolysis is below the lower (analytical) threshold value, results can be reported without restriction; if hemolysis is between the lower and upper thresholds, the results can be issued with guidance in the form of corrective linear equations; and if hemolysis is above the upper (clinical) threshold, the results and sample must be discarded. This method contributes to an optimal approach to hemolysis interference with metabolic profile parameters in blood samples from cows. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Microenvironmental interference with intra-articular stem cell regeneration influences the onset and progression of arthritis.
- Author
-
Zhuce Shao, Benlong Wang, Huanshen Gao, and Shenqi Zhang
- Subjects
STEM cells ,CARTILAGE regeneration ,BONE regeneration ,REGENERATION (Biology) ,JOINTS (Anatomy) ,STEM cell research ,ARTHRITIS - Abstract
Studies have indicated that the preservation of joint health and the facilitation of damage recovery are predominantly contingent upon the joint's microenvironment, including cell-cell interactions, the extracellular matrix's composition, and the existence of local growth factors. Mesenchymal stem cells (MSCs), which possess the capacity to self-renew and specialize in many directions, respond to cues from the microenvironment, and aid in the regeneration of bone and cartilage, are crucial to this process. Changes in the microenvironment (such as an increase in inflammatory mediators or the breakdown of the extracellular matrix) in the pathological context of arthritis might interfere with stem cell activation and reduce their ability to regenerate. This paper investigates the potential role of joint microenvironmental variables in promoting or inhibiting the development of arthritis by influencing stem cells' ability to regenerate. The present status of research on stem cell activity in the joint microenvironment is also outlined, and potential directions for developing new treatments for arthritis that make use of these intervention techniques to boost stem cell regenerative potential through altering the intra-articular environment are also investigated. This review's objectives are to investigate these processes, offer fresh perspectives, and offer a solid scientific foundation for the creation of arthritic treatment plans in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Shape-Memory Alloys—Application in Shrink-Fit Joints †.
- Author
-
Tomova-Damyanova, Elitsa, Ivanov, Vladislav, Tonkov, Georgi, Tsonev, Veselin, and Kuzmanov, Nikola
- Subjects
SURFACE roughness ,HUMAN error ,CHEMICAL resistance ,AERONAUTICS ,ALLOYS ,SHAPE memory alloys - Abstract
Shape-memory alloys have various applications in different fields including medicine, robotics, aeronautics, and micro-electromechanical systems. This paper discusses shrink-fit joints formed by shape-memory alloy elements and their application for the axial fixation of mechanical components. The use of shape-memory alloys gives the shrink-fits some specific features: ease of assembly, insensitivity to tooling and human error, chemical resistance, low cost, etc. The friction force created between the components is experimentally investigated as a function of two parameters—the substrate diameter and the surface roughness (Ra) of one of the joined elements. The results of the experiments are presented analytically and graphically. Conclusions are drawn regarding the behavior of the studied shrink-fits. They can be beneficial to any engineering project making it less sensitive to manufacturing variations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. A Pseudo Elevation of CEA Caused by Epidemic Hemorrhagic Fever.
- Author
-
Hong-Gang Sun, Xiu-Ping Xu, Tao Lu, Ye Yang, and Li-Qin He
- Subjects
HEMORRHAGIC fever ,CHEMILUMINESCENCE immunoassay ,EPIDEMICS ,DELAYED diagnosis ,SYMPTOMS ,RIFT Valley fever - Abstract
Background: Heterophilic antibodies (HA) are one of the main substances that interfere with immunology, especially chemiluminescence immunoassay. Non-specific binding, labeling antibodies, bridging to capture antibodies, or labeling antigens can interfere with the detection process, leading to serious discrepancies between the measured results and clinical manifestations, and even delaying clinical diagnosis and treatment. Methods: This paper is a case of epidemic hemorrhagic fever causing pseudo CEA elevation caused by heterophagy induced antibodies in the body. Results: The patient's CEA detected on the ABBOTT detection platform was 51.1 ng/mL, and on the ROCHE detection platforms it was 4.66 ng/mL, and treated by PEG precipitation it was 45.2 ng/mL, after diluting the sample the CEA was 50.2 ng/mL, meanwhile the patient's platelets were 96 x 109/L and serum creatinine was 188.4 µmol/L, epidemic hemorrhagic fever IgM antibody was positive. Conclusions: When the test results do not match clinical symptoms, further confirmation is required through additional testing. Patients who use mouse monoclonal antibody preparations for diagnosis or treatment may have human anti-mouse antibodies in their serum, and the test results may falsely increase or decrease. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. GPMAS 测定土壤中亚硝酸盐氮的干扰探讨.
- Author
-
杨登, 陈英, 贺小敏, 王卉, and 廖华英
- Abstract
Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
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