186 results
Search Results
2. Is drug interference still an issue for pretransfusion testing of patients on anti CD38 and other monoclonal antibody therapies?
- Author
-
Bevel, Nichole, Thorpe, Meagan, and Vanniasinkam, Thiru
- Subjects
- *
BLOOD transfusion , *BLOOD cells , *CD47 antigen , *MONOCLONAL antibodies , *DARATUMUMAB - Abstract
Certain therapies that target CD markers on some blood cells can affect pretransfusion testing. Key examples are anti‐CD38, CD47 monoclonal antibody (mAb) therapies such as daratumumab (DARA) and magrolimab, which have presented a challenge for transfusion medicine laboratories around the globe. Scientists have been faced with not only introducing a protocol to provide safe blood to patients but also investigating the most effective method to remove the pretransfusion pan‐agglutinating interference caused. A number of papers in the last 5 years have reported on various methods to remove pretransfusion interference; however, most of these studies have been conducted only in a few countries. Most recent reviews on this topic have focused on techniques and reagents to remove pretransfusion interference, and dithiothreitol is currently the gold standard for removing DARA interference. However, it was clear from this review that while many laboratories have developed processes for addressing interference in pretransfusion testing, and DARA interference may not be a major issue, there are still laboratories around the world, that may not have adequately addressed this issue. In addition, the impact of mAb interference on widely used techniques such as flow cytometry is unclear. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Performance analysis of DSSS‐ and CSS‐based physical layer for IoT transmission over LEO satellites.
- Author
-
Jung, Sooyeob, Im, Gyeongrae, Jung, Dong‐Hyun, Kim, Pansoo, Ryu, Joon Gyu, and Kang, Joonhyuk
- Subjects
DOPPLER effect ,INTERNET of things ,ERROR rates ,ORBITS (Astronomy) ,LOW earth orbit satellites ,TELECOMMUNICATION satellites - Abstract
To determine a suitable waveform for Internet of Things (IoT) transmission over low‐Earth orbit (LEO) satellites, this paper reports the results of a performance comparison between chirp spread spectrum (CSS)‐based LoRa and direct sequence spread spectrum (DSSS)‐based Ingenu. The performance of both waveforms was measured in terms of the packet error rate, throughput, and packet loss rate, considering the Doppler effect caused by the high speed of LEO satellites and the interference among multiple terminals. Simulation results indicate that the DSSS scheme is more suitable than the CSS scheme for high‐traffic IoT services because of its robustness against interference among multiple terminals. However, the CSS scheme is more suitable than the DSSS scheme for high‐mobility IoT services because of its robustness against the Doppler effect. We discuss various solutions, such as the preprocessing of Doppler effect and avoidance of packet collision, to enhance the performance of the DSSS and CSS schemes. The simulation results of the proposed solution show that the enhanced DSSS scheme can be a proper waveform in IoT transmission over LEO satellites for both the high‐traffic and high‐mobility services. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. Combination search strategy‐based improved particle swarm optimisation for resource allocation of multiple jammers for jamming netted radar system.
- Author
-
Zou, Wei‐qi, Niu, Chao‐yang, Liu, Wei, Wang, Yan‐yun, and Zhan, Jia‐qi
- Subjects
RADAR interference ,PARTICLE swarm optimization ,RESOURCE allocation - Abstract
This paper presents a new algorithm named combination search strategy (CSS)‐based improved particle swarm optimisation (IPSO) to address the resource allocation problem of multiple jammers. First, the authors propose a CSS to effectively broaden the limited search range of the two‐step solving framework. This method not only simplifies the solution framework but also considers the combined relationship between beam pointing and transmit power to determine the global solution to the original problem directly. Second, the authors propose the IPSO because the complexity of the decision variables is increased by CSS. This method can change the focus of searching the optimal solution at different stages, correct the direction of particle evolution over time and avoid the interference between the variables. Finally, this study simulates the problem of resource allocation of multiple jammers based on the CSS‐IPSO. Based on the simulation results, the combined search strategy can obtain better resource allocation results in a short time, and the IPSO algorithm can further improve the accuracy and stability of the resource allocation results. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Interference in photo‐detachment of triatomic negative ion near a hard reflecting surface.
- Author
-
Khan, Farooq, Rehman, Habib U., Asif, Syed M., Khan, Muhammad Abbas, and Khan, Muhammad Aslam
- Subjects
ANIONS ,ELECTRON affinity ,PHENOMENOLOGICAL theory (Physics) ,COHERENT radiation ,RADIATION sources - Abstract
The physical phenomena in which an extra electron is removed from a negative ion is called photo‐detachment. Photo‐detachment is important phenomena, used to find the structure of anions, particularly to find the electron affinities. In this paper, we present theoretically the induced effects in the photo‐detached of triatomic anion H3− near hard reflecting wall or surface. For the photo‐detachment process, a z‐polarized coherent source of radiations (laser) is used to kick electrons from H3− anion in the domain of a hard reflecting surface. Imaging method is adopted to derive the generalized detached electron wave, differential cross‐section and the total photo detachment cross‐section analytically. Numerical solutions (simulations) for total electron flux and the total cross‐section is presented. The electron flux, shows visible oscillations and hence the induced effect of surface in the interference. It is depicted that the reflecting hard wall strongly affects the flux and total photo‐detachment cross‐section. The analytical results are extended for triiodide I3− anion numerically, which also show interference. The total photo detachment cross‐section for I3− is calculated numerically and compared with cross‐section of H3−. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Performance dependency of LSTM and NAR beamformers with respect to sensor array properties in millimeter‐wave V2I scenario.
- Author
-
Kumar, Ravi and Singh, Hardeep
- Subjects
WIRELESS channels ,SENSOR arrays ,COMPLEX variables ,BEAMFORMING ,TIME series analysis - Abstract
Interference prediction is a challenging problem in millimeter‐wave V2I scenarios. The implementation of a practical V2I network is limited because of the interference due to the random nature of the wireless channel. This paper proposes an adaptive beamforming technique for mitigation of interference in V2I networks. In this work, long short‐term memory (LSTM) and nonlinear autoregressive (NAR)‐based regressors have been employed to predict the angles between the RSU and UE. Advance prediction of transmit and receive signals enables reliable V2I communication. Instead of predicting the beamforming matrix directly, we predict the main features using LSTM for learning dependencies in the input time series where complex variables were taken as input states and the final beamformed signal was the output. Simulation results have confirmed that the proposed LSTM model achieves comparable performance in terms of system throughput compared to the NAR method implemented as an artificial neural network. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. Channel scintillations of array global navigation satellite system receiver under distributed intermittent interferences.
- Author
-
Wang, Jie, Liu, Wenxiang, Ou, Gang, Xiao, Wei, Wang, Haibin, and Dong, Tianbao
- Subjects
GLOBAL Positioning System ,RADAR interference ,PHASE-locked loops ,ARTIFICIAL satellites in navigation - Abstract
Non‐stationary interferences are parts of the global navigation satellite system (GNSS) threats; this paper focusses on the impact of intermittent interferences on the baseband processing of the array GNSS receiver. We call the jitters of channel response caused by distributed intermittent interferences as channel scintillations. The inevitability of the channel scintillations under intermittent interferences was illustrated first. Then, the characteristics of channel scintillations were analysed through theory analysis and simulations. Finally, the impact of channel scintillations on the receiver baseband processing was assessed. The results show that though the intermittent interferences power can be suppressed completely by the anti‐jamming filter, the phase lock loop may lose lock due to channel scintillations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
8. Toward an Understanding of Cognitive Mapping Ability Through Manipulations and Measurement of Schemas and Stress.
- Author
-
Maxim, Paulina and Brown, Thackery I.
- Subjects
COGNITIVE ability ,COGNITIVE aging ,SPATIAL memory ,PSYCHOLOGICAL factors ,PSYCHOLOGICAL stress ,COGNITIVE maps (Psychology) - Abstract
Daily function depends on an ability to mentally map our environment. Environmental factors such as visibility and layout, and internal factors such as psychological stress, can challenge spatial memory and efficient navigation. Importantly, people vary dramatically in their ability to navigate flexibly and overcome such challenges. In this paper, we present an overview of "schema theory" and our view of its relevance to navigational memory research. We review several studies from our group and others, that integrate manipulations of environmental complexity and affective state in order to gain a richer understanding of the mechanisms that underlie individual differences in navigational memory. Our most recent data explicitly link such individual differences to ideas rooted in schema theory, and we discuss the potential for this work to advance our understanding of cognitive decline with aging. The data from this body of work highlight the powerful impacts of individual cognitive traits and affective states on the way people take advantage of environmental features and adopt navigational strategies. This review examines our ability to mentally map spatial environments. We draw connections to schema theory and the ways it can influence navigational memory. We discuss environmental factors and individual differences in cognitive traits, stress, and age‐related decline that could together influence mapping ability across the lifespan. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
9. Review of ferroelectric field‐effect transistors for three‐dimensional storage applications.
- Author
-
Park, Hyeon Woo, Lee, Jae‐Gil, and Hwang, Cheol Seong
- Abstract
The ferroelectric field‐effect transistor (FeFET) is one of the leading contenders to succeed charge‐trap‐based flash memory (CTF) devices in the current vertically‐integrated NAND flash storage market. The operation of a FeFET is based on the field‐effect in the channel of the FET that is exerted by the uncompensated ferroelectric bound charge, which is also the fundamental source of the depolarization effect. This paper briefly reviews the current status of CTF‐based NAND flash memory as a benchmark for FeFET. Then, a one‐dimensional model based on a load‐line analysis of FeFET technology is presented. The paper subsequently deals with the two‐dimensional domain effect in nano‐sized NAND‐type FeFET devices. While NAND‐type FeFET operation is likely, current ferroelectric materials with high remanent polarization (Pr) of ∼10 μCcm‐2 and coercive field (Ec) of ∼1 MVcm‐1 are not feasible for use in such devices. This is fundamentally due to the high depolarization field induced by the unnecessarily high Pr, which not only destabilizes the memory state but also induces a severe interference effect between neighboring cells. Therefore, a new ferroelectric material with a moderately low Pr and higher Ec > ∼3 MVcm‐1 is necessary, along with structural innovation to minimize the interference effect. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
10. Targeted maximum likelihood estimation of causal effects with interference: A simulation study.
- Author
-
Zivich, Paul N., Hudgens, Michael G., Brookhart, Maurice A., Moody, James, Weber, David J., and Aiello, Allison E.
- Subjects
COMPUTER simulation ,ATTRIBUTION (Social psychology) ,QUESTIONNAIRES ,RESEARCH funding ,PROBABILITY theory - Abstract
Interference, the dependency of an individual's potential outcome on the exposure of other individuals, is a common occurrence in medicine and public health. Recently, targeted maximum likelihood estimation (TMLE) has been extended to settings of interference, including in the context of estimation of the mean of an outcome under a specified distribution of exposure, referred to as a policy. This paper summarizes how TMLE for independent data is extended to general interference (network-TMLE). An extensive simulation study is presented of network-TMLE, consisting of four data generating mechanisms (unit-treatment effect only, spillover effects only, unit-treatment and spillover effects, infection transmission) in networks of varying structures. Simulations show that network-TMLE performs well across scenarios with interference, but issues manifest when policies are not well-supported by the observed data, potentially leading to poor confidence interval coverage. Guidance for practical application, freely available software, and areas of future work are provided. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
11. Enhance packet transmission using improved channel assignment in wireless mess network.
- Author
-
Sathyasri, B., Ganesh, E.N., and Senthilkumar, P.
- Subjects
WIRELESS channels ,MESH networks ,WIRELESS mesh networks ,WIRELESS LANs ,NETWORK performance - Abstract
Summary: An efficient technique called channel Assignment (CA) is used to exploit the multiple non‐overlapping channels that improves capacity and decreases intervention in the wireless mesh network. Although it can reduce total network interference, there may be certain design issues by which network performance can be unfair. For maximizing the usage of wireless LAN network spectrum in these environments, many studies have discovered how to use the complete spectrum while transferring the data via mesh network. The proposed paper elaborates about the Enhanced Traffic‐Aware Channel Assignment Protocol. This protocol helps the mesh nodes present in the large‐scale mesh networks to assign the channels. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
12. Radio resource management for large constellations in a spectrum sharing environment.
- Author
-
Re, Emiliano, Murrell, Andrew, and Roques, Damien
- Subjects
RADIO resource management ,ARTIFICIAL satellites ,BROADBAND communication systems ,ALGORITHMS ,DELIVERY of goods ,MACHINE-to-machine communications ,COGNITIVE radio - Abstract
Summary: In the last five years, the satellite community has witnessed growing interest in the delivery of Broadband Services from non‐geostationary orbit (NGSO) systems. However, accessing the entire spectrum available without having to share it among the different operators is key for these systems to have a chance of breaking even, which makes for a challenging business case. This paper focuses on the challenges of spectrum coexistence of multiple satellite constellations for broadband communications and proposes a radio resource management algorithm to enable such coexistence. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Analogous on‐axis interference topographic phase microscopy (AOITPM).
- Author
-
XIU, P., LIU, Q., ZHOU, X., XU, Y., KUANG, C., and LIU, X.
- Subjects
PHASE-contrast microscopes ,OPTICAL interference ,CONTRAST media ,REFRACTIVE index ,THREE-dimensional imaging ,IMAGE reconstruction - Abstract
Copyright of Journal of Microscopy is the property of Wiley-Blackwell 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
- 2018
- Full Text
- View/download PDF
14. Adaptive Carrier Frequency Offset Estimation in Interference Environments for OFDMA Uplink Systems.
- Author
-
Cheng, Nan‐Hung, Chen, Chien‐Chung, Wang, Yi‐Fan, and Chen, Yung‐Fang
- Subjects
- *
FREQUENCY division multiple access , *SIGNAL processing - Abstract
In orthogonal frequency division multiple access (OFDMA) systems, carrier frequency offsets (CFOs) influence the different users. In this paper, we proposed a CFO estimation algorithm with strong interference resistant capability for OFDMA systems. The first part of the proposed algorithm processes the received signals so as to deal with the CFO estimation problem. And the second part of the proposed algorithm is to use the proposed adaptive process to obtain the updated CFO estimation and track the parameters' time‐variations. Simulations demonstrate the effectiveness of this method and show that its performance is to the Cramer‐Rao Bounds (CRB). © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. Exploring the alternatives to the conventional interference mitigation schemes for 5G wireless cellular communication network.
- Author
-
Bindle, Abhay, Gulati, Tarun, and Kumar, Neeraj
- Subjects
WIRELESS communications ,5G networks ,QUALITY of service ,DATA packeting ,HIGH technology ,AD hoc computer networks ,FEMTOCELLS - Abstract
Summary: The manifold increase in the number of cellular wireless network consumers has presented a monumental challenge to upgrade the current infrastructure for imparting superior throughput and good quality of service. End‐users of the network will want super high‐speed data with very low latency, as well as secure and with a lower packet data drop rate. Joint coordination between various network resources such as that of a dense heterogeneous network is crucial for achieving the above demands. It is also inevitable that such a dense arrangement of small cells or macro cells or other network equipment will be challenged by different forms of interference apart from being costly and less mobile. Beamforming is among the most advanced technology that is available up to date which has shown good results at handling interference and at guiding transmitted data to the desired end‐user. It is quite useful but also struggles from certain factors when deployed in a dense network. A thorough review of recent works of literature is detailed in the current paper with a focus placed on two major fields, which are interference mitigation techniques and gainful interference exploitation techniques. Some highly advanced interference mitigation techniques which are either developed or under development with their merits have been proposed. Most of these techniques use machine learning and artificial intelligence‐based methods to ensure the best quality of service (QoS) to every individual connected to the network. However some research works focused on negating away any kind of interference present in a signal, some focused on harnessing interference for optimizing the power of transmitted signals. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
16. A proportional fair scheduling strategy using multiobjective gradient‐based African buffalo optimization algorithm for effective resource allocation and interference minimization.
- Author
-
Kesavan, Dhivya, Periyathambi, Ezhumalai, and Chokkalingam, Arun
- Subjects
RESOURCE allocation ,MATHEMATICAL optimization ,ALGORITHMS ,COMPUTATIONAL complexity - Abstract
Summary: The increased usage of Internet of Things (IoT) applications in several areas, like healthcare, agriculture, and business, has aggravated mobile traffic issues to a large extent. The deployment of 5G technology has resulted in increased traffic globally. These coherent devices, on the other hand, use the internet to fine‐tune the quality of service in order to provide scalability, anonymity, and accessibility. Despite its numerous virtues, it is bound to encounter issues with interference management, fairness, throughput, and computational complexities. In this paper, a novel Multi‐Objective Gradient‐based African Buffalo Optimization (MOGABO) algorithm is developed to handle proportional fairness scheduling, improve interference management, increase throughput, and reduce computational complexities in cellular communication systems, particularly device‐to‐device (D2D) communication. The simulation analysis is done against other approaches such as the Hungarian technique, DDDPG technique, heuristic technique, and SC‐FDMA technique demonstrates that this method has improved system fairness over the existing approaches. Our method maximizes throughput, and for 500 UE, the throughput is 10.4 Mbps, with an average queuing delay of 24 ms. As a result, when compared to the existing method, MOGABO method offers a 1.2% increase in throughput. Thus, our method offers better coverage and throughput for D2D cellular communication with the reduction of computational complexities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. Comparison of damping techniques for the soft-stop of ultra-fast linear actuators for HVDC breaker applications.
- Author
-
Vilchis-Rodriguez, Damian S., Shuttleworth, Roger, Smith, Alexander C., and Barnes, Mike
- Subjects
ACTUATORS ,HIGH-voltage direct current transmission ,ELECTRIC circuit breakers ,ENERGY consumption ,DAMPING (Mechanics) ,FINITE element method - Abstract
This paper assesses the advantages, drawbacks, and overall suitability of different soft-stop techniques to provide smooth deceleration of ultra-fast linear actuators used in hybrid HVDC breaker designs, with the help of FEA simulations. The paper compares active and passive damping techniques in terms of efficacy, energy consumption, and interference with the ultra-fast operation needed from the actuator. The possibility of combining active and passive damping techniques is discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
18. A Review of Spatial Causal Inference Methods for Environmental and Epidemiological Applications.
- Author
-
Reich, Brian J., Yang, Shu, Guan, Yawen, Giffin, Andrew B., Miller, Matthew J., and Rappold, Ana
- Subjects
CAUSAL inference ,RANDOM fields ,COVID-19 ,CONFOUNDING variables ,ENVIRONMENTAL sciences ,AIR pollution ,AIR pollution control - Abstract
Summary: The scientific rigor and computational methods of causal inference have had great impacts on many disciplines but have only recently begun to take hold in spatial applications. Spatial causal inference poses analytic challenges due to complex correlation structures and interference between the treatment at one location and the outcomes at others. In this paper, we review the current literature on spatial causal inference and identify areas of future work. We first discuss methods that exploit spatial structure to account for unmeasured confounding variables. We then discuss causal analysis in the presence of spatial interference including several common assumptions used to reduce the complexity of the interference patterns under consideration. These methods are extended to the spatiotemporal case where we compare and contrast the potential outcomes framework with Granger causality and to geostatistical analyses involving spatial random fields of treatments and responses. The methods are introduced in the context of observational environmental and epidemiological studies and are compared using both a simulation study and analysis of the effect of ambient air pollution on COVID‐19 mortality rate. Code to implement many of the methods using the popular Bayesian software OpenBUGS is provided. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
19. Two new power allocation schemes for an OFDM cognitive radio with no knowledge on primary users' interference.
- Author
-
Mahmoodi, Seyed Eman and Abolhassani, Bahman
- Subjects
COGNITIVE radio ,ORTHOGONAL frequency division multiplexing ,KNOWLEDGE management ,INTERFERENCE (Telecommunication) ,SIGNAL processing ,COMPUTER simulation - Abstract
SUMMARY In this paper, we propose two new power loading schemes for an OFDM cognitive radio (CR). The novelty of this paper is that the CR has no knowledge about the interference power introduced by primary users (PUs). In the first scheme, we maximize the total received signal power on all CR subcarriers as the objective function with the two constraints: (i) keeping the interference to the PUs below a given threshold, and (ii) allocating less than peak transmit power as the total power levels on all CR subcarriers. The second proposed scheme is similar to the first one with one more constraint, which is more power loading to the CR subcarriers experiencing higher ratio of channel power gain to the noise power. This third constraint results in increasing CR throughput (similar to the water-filling scheme). Performances of these schemes are analyzed by numerical and simulation results, which illustrate that the two proposed schemes achieve relatively close to the optimal scheme (in which the secondary transmitter has full knowledge about PUs' interference power) and outperform the scheme based on estimation of this interference power with an estimation error higher than a given threshold. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
20. Generalized maximum correntropy detector for non‐Gaussian environments.
- Author
-
Hakimi, Saeed and Abed Hodtani, Ghosheh
- Subjects
GAUSSIAN processes ,GENERALIZATION ,ELECTRIC interference ,SOLID state detectors ,NOISE - Abstract
Summary: This paper addresses the problem of multiple‐hypothesis detection. In many applications, assuming the Gaussian distribution for undesirable disturbances does not yield a sufficient model. On the other hand, under the non‐Gaussian noise/interference assumption, the optimal detector will be impractically complex. Therewith, inspired by the optimal maximum likelihood detector, a suboptimal detector is designed. In particular, a novel detector based on the generalized correntropy, which adopts the generalized Gaussian density function as the kernel, is proposed. Simulations demonstrate that, in non‐Gaussian noise models, the generalized correntropy detector significantly outperforms other commonly used detectors. The efficient and robust performance of the proposed detection method is illustrated in both light‐tailed and heavy‐tailed noise distributions. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
21. 57.2: Error Analysis in LCoS Phase Uniformity Measurement with Classical Polarimetric Method for Holographic Display Applications.
- Author
-
Zhang, Xinyue and Li, Kun
- Subjects
HOLOGRAPHIC displays ,POLARIMETRY ,OPTICAL measurements ,UNIFORMITY ,LIQUID silicon ,LIQUID crystals ,MEASUREMENT errors - Abstract
The classical polarimetric method has been widely used in Liquid Crystal on Silicon (LCoS) phase depth measurement with a simple optical setup. However, the current method does not provide sufficient accuracy to measure the phase uniformity due to interference caused by LCoS cover glass reflections. This paper is aimed at mathematically analyzing the errors caused by non‐ideal glass reflections, and proposing procedures to reduce or eliminate such errors. The measurement is discussed in three conditions, including an ideal condition with no reflections off the LCoS cover glass, a second condition with only forward reflection off the cover glass and a third condition with only backward reflection off the cover glass. It is discovered that the backward reflection has the largest contribution to the overall measurement error, and is the main obstacle to high‐quality measurements. Several procedures including optical alignment, gap thickness measurement and phase estimation based on gap thickness are proposed, making the uniformity measurement more qualitative and consistent. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. GNSS interference mitigation: A measurement and position domain assessment.
- Author
-
Borio, Daniele and Gioia, Ciro
- Subjects
GLOBAL Positioning System ,NOTCH filters ,ADAPTIVE filters ,RADIO interference - Abstract
Modern Global Navigation Satellite System (GNSS) receivers have to withstand significant levels of interference in order to operate under harsh conditions, such as in the presence of jamming and of other Radio Frequency (RF) threats. A possibility is to implement pre‐correlation interference mitigation techniques that operate directly on the samples provided by the receiver front‐end. This paper provides an assessment of five interference mitigation techniques at the measurement and position level. The analysis focuses on the Adaptive Notch Filter (ANF) and on four Robust Interference Mitigation (RIM) techniques. Several data collections were performed in the presence of jamming, and the data collected were used for the analysis that shows that RIM techniques do not introduce biases at both the measurement and position level. While the ANF delays pseudorange measurements, the biases introduced are predominantly common to all the observations with a negligible impact on a Single Point Positioning (SPP) solution. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
23. WLAN interference self-optimization using som neural networks.
- Author
-
Yao, Haipeng, Yang, Hao, Zhang, Anqi, Fang, Chao, and Guo, Yiru
- Subjects
WIRELESS LANs ,SELF-organizing systems ,ARTIFICIAL neural networks ,SELF-organizing maps ,MATHEMATICAL optimization - Abstract
In order to suppress the interference in local area networks, this paper presents a Wireless Local Area Networks (WLAN) interference self-optimization method based on a Self-Organizing Feature Map (SOM) neural network model. This method trains the model by using original data sets as the initial vector set and using the whole Signal to Interference plus Noise Ratio (SINR) vector generated by the change of one Wireless Access Point (AP) channel as the basic feature. After the training, the SOM neural network can quickly locate the fault AP and optimize the network according to the changes of the network environment. Simulation results reveal that the proposed scheme can efficiently locate the AP where interference happens and optimize the interference with an improved user experience. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
24. Interference management for spectral coexistence in a heterogeneous satellite network.
- Author
-
Hajipour, Pedram, Shahzadi, Ali, and Ghazi‐Maghrebi, Saeed
- Subjects
ARTIFICIAL satellites ,POWER transmission ,MOBILE satellite communication ,TELECOMMUNICATION systems ,5G networks ,ARTIFICIAL satellite tracking ,RADIO (Medium) ,COGNITIVE radio - Abstract
Summary: With the advent of the fifth generation of mobile radio communication by 2020, there will be many challenges such as increasing service demand with low delay in providing billions of end users called the satellite mobile users. It is expected that terrestrial communication systems will be faced with a dense network having many small cells anywhere and anytime. Therefore, there are some remote regions in the world where terrestrial systems cannot provide any services to end users. Furthermore, because of lack of spectral resources, it is very important that the spectrum is shared between satellite systems and terrestrial equipment by a suitable solution to interference management. In this paper, a heterogeneous satellite network that includes low earth orbit (LEO) satellite constellation and terrestrial equipment is proposed to provide low delay services. In this type of structure, interference management based on transmission power control between LEO satellite systems and mobile users is very important for obtaining high throughput. Moreover, in order to mitigate interference, transmission power control is shown based on noncooperative Stackelberg game under many subgames through pricing‐based algorithm and convex optimization method. Finally, the simulation results show that the performance of this study's system model will be improved through the proposed algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
25. Interference characteristics in intervehicle communication from oncoming vehicles.
- Author
-
Michael, Lachlan B. and Nakagawa, Masao
- Subjects
TRANSPORTATION ,COMPUTER simulation ,SIMULATION methods & models ,COMMUNICATION ,COMMUNICATIONS industries ,TELECOMMUNICATION - Abstract
The use of intervehicle communication (IVC) is considered an integral part of future intelligent transportation systems (ITS). Several protocols have been proposed, although the problems of interference have largely been ignored. In particular, the problem of interference from vehicles in oncoming lanes has not been investigated before. In this paper we examine the problem of interference from vehicles in oncoming lanes in the millimeter band using a two-path Rician fading model and show that the worst cases present a level of interference which must be avoided. As methods to reduce interference we propose the use of CDMA and using different frequency allocations for transmission from forward-looking directional antennas and rear-looking directional antennas, which we term directional frequency division duplexing. The usefulness of this method is confirmed by computer simulation. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(2): 9–18, 2001 [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
26. Rational and Facile Construction of 3D Annular Nanostructures with Tunable Layers by Exploiting the Diffraction and Interference of Light.
- Author
-
Choe, Jong‐Ho, Park, Q‐Han, and You, Eun‐Ah
- Subjects
NANOSTRUCTURES ,ULTRAVIOLET radiation ,PHOTOLITHOGRAPHY ,PHOTORESISTS ,CHEMICAL kinetics - Abstract
This paper reports a rational and facile approach to fabricating arrays of 3D annular nanostructures with tunable layers by utilizing the diffraction and interference of UV light. Based on discretized Fresnel bright spots and standing waves formed within a photoresist film, the structures with nanoscale features are realized using simple, conventional photolithography. The 3D annular nanostructures are produced in arrays of single-, double-, and triple-layered ring structures with the height of single layer on a 100 nm scale. The structural formation process and features of the nanostructures are analyzed and explained through 3D modeling that integrates the effects of both UV exposure dose and chemical kinetics. The approach to generating 3D annular nanostructures with tunable layers and discrete heights can be adapted for various applications that require the 3D structures fabricated over a large area with high throughput. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
27. Towards the Terabit/s satellite - interference issues in the user link.
- Author
-
Lutz, Erich
- Subjects
BROADBAND communication systems ,TELECOMMUNICATION satellites ,INTERFERENCE (Telecommunication) ,GEOSTATIONARY satellites ,BIT rate - Abstract
Present high-capacity geostationary satellites provide throughput in the range of 70 Gb/s (Ka-Sat) up to 140 Gb/s (ViaSat-1, EchoStar 17). In order to keep up with the quickly increasing bit rate requirements of new services and applications, future communication satellites must increase their capacity by an order of magnitude, thus reaching the terabit/s throughput range. The challenge of achieving a terabit/s satellite system requires investigation of a multitude of issues, limitations and problems. This paper discusses the main interference effects occurring in the user uplinks and downlinks of a multi-beam satellite: co-channel interference, adjacent-channel interference and cross-polarisation interference. Different cluster sizes for the beam pattern and use of dual polarisations are considered, and an optimum cluster scheme with regard to throughput is discussed in more detail. Moreover, the influence of beam spacing, interference cancellation for the user uplink as well as rain fading for the uplink and downlink are discussed. For the satellite spot beam antenna, a typical tapered antenna characteristic with side lobes is considered. The investigation is based on Monte Carlo simulation of user positions within the beam pattern, resulting in CDFs of signal-to-noise-plus-interference power ratio and capacity. Besides Shannon capacity, the achievable throughput of Digital Video Broadcasting - Return Channel over Satellite, 2nd Generation (DVB-RCS2), Digital Video Broadcasting over Satellite, 2nd Generation (DVB-S2) and Digital Video Broadcasting over Satellite, 2nd Generation, Extension (DVB-S2X) is evaluated. Considering 200 beams and 1 GHz of bandwidth, it is shown that with efficient uplink and downlink schemes, a total throughput of 1 Tb/s can be approached. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
28. Tectonic, Topographic, Geologic, and Hydroclimatic Influence on Crack Formation During the 2021 Haiti Earthquake.
- Author
-
Saint Fleur, Newdeskarl, Dessable, Joseph E., Saint‐Preux, Germain, Calais, Éric, Feuillet, Nathalie, Boisson, Dominique, de Chabalier, Jean‐Bernard, and Klinger, Yann
- Subjects
RAINFALL ,SLOPES (Soil mechanics) ,ALLUVIUM ,MARL ,GEOLOGY - Abstract
The 14 August 2021 Haiti earthquake mainly portrayed reverse motion to the east near L'Asile town and left‐lateral strike‐slip motion to the west near Camp‐Perrin town. To map the rupture and infer its segmentation, we conducted the first post‐seismic field reconnaissance along the left‐lateral strike‐slip Enriquillo fault from L'Asile to Macaya mountain. We identified 98 linear, minor cracks that are not representative of primary fault surface rupture. Analyzing the topographic slope distribution, we detected that the cracks were often located in areas that are prone to topographic instability. About 60% of the cracks are located in Quaternary alluvium and Middle‐Miocene continental marls, indicating a preference for soft sediments. The rivers also have an impact, as crack lengths and openings negatively correlate with their distance to neighboring rivers. In addition, the earthquake occurred in a rainy region with up to 2,479.34 mm of rainfall in 2021, increasing soil instability. Above all, we found a contrast and asymmetry between the eastern and the western parts of the rupture. By dividing the 60‐km long rupture into two equal parts, we observed 57 cracks to the west against 41 to the east. The longest and the widest cracks are to the west. Analyzing their orientation, the cracks mainly oriented as left‐lateral strike‐slip faults to the west and mainly thrusts to the east. This configuration appears to be influenced by the slip pattern of the 2021 Haiti earthquake and consistent with the regional stress field. Key Points: Alongside geology, topography, and hydroclimate, tectonics is the biggest factor for crack generation during the 14 August 2021, Mw 7.2 Haiti earthquakeThrust and sinistral strike‐slip cracks partition similarly to the earthquake slip pattern and to the oblique‐convergence margin [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Beam-Space CMA Adaptive Array Antennas.
- Author
-
Chiba, Isamu, Chujo, Wataru, and Fujise, Masayuki
- Subjects
ALGORITHMS ,ADAPTIVE antennas ,ANTENNAS (Electronics) ,FOURIER transforms ,SIMULATION methods & models ,FOUNDATIONS of arithmetic - Abstract
In the communication system using a constant modulus signal, a constant modulus algorithm (CMA) adaptive array antenna is effective for elimination of the frequency-selective tiding generated in multiple propagation paths. On the other hand, in the system in which CMA adaptive loops are installed for each antenna element in an array with mare than 10 elements used for mobile satellite communication, the computing time and the amount of hardware become excessive. in this paper, a beam-space CMA adaptive array antenna (BSCMA) is proposed in which a portion of the multibeam output is selected to form a CMA adaptive array. In the BSCMA, first, a multibeam is formed by means of a fast Fourier transform (FFT) and only the beams whose output power exceeds a threshold level are selected. An adaptive process is carried out with the CMA as a guiding principle only for the selected beam outputs. The BSCMA has an advantage of carrying out the capture of the desired wave and the elimination of the interference wave effectively with degrees of freedom corresponding to the number of arriving waves. The method is effective for an adaptive antenna system applied to an array antenna constructed with many antenna elements. In this paper, the configuration of the BSCMA is shown and its characteristics are investigated by the numerical simulation. [ABSTRACT FROM AUTHOR]
- Published
- 1995
- Full Text
- View/download PDF
30. Analysis of interference and availability between satellite and ground components in an integrated mobile-satellite service system.
- Author
-
Kang, Kunseok, Park, Jong Min, Kim, Hee Wook, Hong, Tae Chul, Ku, Bon Jun, and Chang, Dae‐Ig
- Subjects
MOBILE satellite communication ,TELECOMMUNICATION satellites ,MOBILE communication systems ,TELECOMMUNICATION systems ,MOBILE computing - Abstract
An integrated mobile-satellite service (MSS) system is one of the most promising infrastructures for the efficient use of satellite frequency, and the satellite coverage can be extended by reusing the satellite frequency in its ground components. However, the co-channel interferences caused by the frequency reusing technique may lead to the performance degradation. This paper presents the interference analysis for an integrated MSS system that is composed of a multi-beam satellite, complementary ground components (CGCs), and mobile earth stations, by using statistical simulations. These statistical results are then used to evaluate the availability of the system. Our simulation results reveal that the satellite frequency reuse in the CGCs of the integrated MSS system can increase efficiency of satellite spectrum utilization with a tradeoff between CGC network capacity and intra-system interferences. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
31. Interference-aware MAC scheduling and admission control for multiple mobile WBANs used in healthcare monitoring.
- Author
-
Mahapatro, Judhistir, Misra, Sudip, Mahadevappa, Manjunatha, and Islam, Nabiul
- Subjects
BODY area networks ,TIME division multiple access ,ACCESS control of computer networks ,SIGNAL-to-noise ratio ,COMPUTER simulation ,HEALTH services administration ,MOBILE communication systems - Abstract
In this paper, we address the problem of interference when multiple time division multiple access-based wireless body area networks (WBANs) come in the proximity of one another. We propose a simple solution that creates common non-conflicting schedule between these interfering WBANs. Our proposed scheme allows the reuse of maximum possible time slots among WBANs that are two-hop neighbors of one another. A flow admission control scheme is applied to control the flows during the period of interference. We show that the percentage of flows admitted because of flow control decreases with the increase in the network size and flow rate. We simulated a scenario where WBANs move randomly within a simulation area with a certain speed and meet at a particular point. We show that the signal to interference noise ratio (SINR) value of WBANs changes as long as they are within the transmission range of one another. Also, we show that the exchanges of common schedule (which is dependent on the number of times the SINR value drops below the threshold) are required in order to improve the packet delivery ratio in WBANs. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
32. A probabilistic model to describe the interference produced by VSAT MF‐TDMA networks.
- Author
-
Rubin de Celis Vidal, Américo Ariel and Fortes, José Mauro
- Subjects
TIME division multiple access ,GLOBAL Positioning System ,DISCRETE choice models ,REMOTE sensing ,EARTH stations - Abstract
Summary: This paper develops a mathematical model to describe the statistical behavior of the interference produced by VSAT/MF‐TDMA networks. The model is used to assess the interference produced by the uplinks of a VSAT/MF‐TDMA network into links of a network that uses a neighboring satellite. In the proposed model, analytical expressions were developed to account for the effects of variations in transmitting powers, antenna sizes, and transmitting antenna pointing errors. The earth station locations are modeled by a 2‐dimensional Poisson point process. The model is general enough to accommodate other types of point processes and can be applied to situations involving service areas containing multiple types of earth station geographical distribution. Numerical results obtained with the proposed model are compared with those based on the actual parameter values (eg, earth station locations, antenna sizes, and transmitting powers), which were provided by a Brazilian satellite operator. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. Cognitive radio network with coordinated multipoint joint transmission.
- Author
-
Reasat, Tahsin, Saha, Abir, and Uddin, Md. Forkan
- Subjects
COGNITIVE radio ,SIGNAL-to-noise ratio ,LINEAR programming ,BANDWIDTH allocation ,WIRELESS communications - Abstract
Cognitive radio (CR) is considered to be a promising technology for future wireless networks to make opportunistic utilization of the unused or underused licensed spectrum. Meanwhile, coordinated multipoint joint transmission (CoMP JT) is another promising technique to improve the performance of cellular networks. In this paper, we propose a CR system with CoMP JT technique. We develop an analytical model of the received signal-to-noise ratio at a CR to determine the energy detection threshold and the minimum number of required samples for energy detection-based spectrum sensing in a CR network (CRN) with CoMP JT technique. The performance of energy detection-based spectrum sensing under the developed analytical model is evaluated by simulation and found to be reliable. We formulate an optimization problem for a CRN with CoMP JT technique to configure the channel allocation and user scheduling for maximizing the minimum throughput of the users. The problem is found to be a complex mixed integer linear programming. We solve the problem using an optimization tool for several CRN instances by limiting the number of slots in frames. Further, we propose a heuristic-based simple channel allocation and user scheduling algorithm to maximize the minimum throughput of the users in CRNs with CoMP JT technique. The proposed algorithm is evaluated via simulation and found to be very efficient. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
34. A deep model‐based channel interference mitigation for OTFS signals in ISAC systems.
- Author
-
Zhou, Wenkai, Wang, Wenming, Qi, Wanbin, and Zhang, Ronghui
- Subjects
CHANNEL estimation ,PARAMETER estimation ,SIGNALS & signaling - Abstract
In recent years, Orthogonal Time Frequency Space Modulation (OTFS) has gained popularity in integrated sensing and communications (ISAC) system due to its robustness against Doppler offset and delay changes. Traditional pilot‐based methods for accurate channel parameter estimation are complex and struggle with rapidly changing channel conditions. In this letter, a deep encode‐decode network (DED‐Net) is proposed. It uses DL to automatically learn and eliminate channel interference from OTFS signals. The framework employs a deep encoding and decoding network, similar to a filter, learning complex signal features to effectively remove interference. Our experiments demonstrate DED‐Net's ability to eliminate interference in OTFS modulation signals, offering an alternative to pilot‐based methods and showcasing DL's potential for ISAC systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. On the interference from space research service uplink transmissions into the inter-satellite links of a non-GSO system operating in the 22-GHz band.
- Author
-
Fortes, José Mauro P. and Goicochea, Juan Otalora
- Abstract
SUMMARY This paper presents a compatibility analysis involving space research service lunar mission uplink transmissions and the inter-satellite links of non-geostationary orbit systems operating in the 22-GHz band. Three points differentiate this analysis from the currently available studies: (1) the mathematical model used here allows for the consideration of the time varying nature of the inclination of the Moon orbital plane; (2) besides the usual unconditional interference cumulative distribution functions, this analysis also considers the conditional cumulative distribution functions given that the victim satellite is receiving interference, important to characterize the interference affecting users that, because of their location, are most of the time using satellites, which are under interference; and (3) instead of dynamic time simulation, the analytical method in Recommendation ITU-R S.1529 is used to determine the various cumulative distribution functions involved. Four scenarios are examined in the paper. Their main differences concern the number and location of the space research service transmitting Earth stations and the strategy under which they are active (transmitting). In all scenarios, cumulative distribution functions of the ratio I/ N were determined for both the in-band and the out-of-band interference cases. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
36. A tractable analytical model for interference characterization and minimum distance enforcement to reuse resources in three-dimensional in-building dense small cell networks.
- Author
-
Saha, Rony Kumer and Aswakul, Chaodit
- Subjects
CO-channel interference ,RESOURCE allocation ,FEMTOCELLS ,NUMERICAL analysis ,SIMULATION methods & models ,5G networks ,DATA transmission systems - Abstract
In this paper, we address mainly 2 important issues, namely, characterizing co-channel interference and enforcing a minimum distance between femtocell base stations (FCBSs) for reusing resources in FCBSs deployed in a 3-dimentional multi-floor building. Each floor is modeled as a group of square-grid apartments, with one FCBS per apartment. We propose a simple yet reasonable analytical model by using planar-Wyner model for intra-floor interference and linear-Wyner model for inter-floor interference modeling in a 3-dimensional multi-floor building to derive a minimum distance between co-channel FCBSs for optimization constraints, namely, link level interference, spectral efficiency, and capacity. As opposed to orthogonal resource reuse and allocation (ORRA) where resources are reused once, using the proposed model, we develop 2 strategies for reusing resources more than once, that is, non-ORRA, within a multi-floor building. An algorithm of the proposed model is developed by including an application of the model to an ultra-dense deployment of multi-floor buildings. With an extensive numerical analysis and system level simulation, we demonstrate the capacity outperformance of non-ORRA over ORRA by manifold. Further, with a fairly accurate yet realistic estimation, we show that the expected spectral efficiency of fifth-generation networks can be achieved by applying the proposed model to an ultra-dense deployment of FCBSs. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
37. Energy‐efficient interference management in LTE‐D2D communication.
- Author
-
Mumtaz, Shahid, Saidul Huq, Kazi Mohammed, Rodriguez, Jonathan, and Frascolla, Valerio
- Abstract
This paper focuses on one of the key enabling technology that will compose future 5G network, the Direct‐LTE communication underlying a cellular infrastructure, also commonly known as Device‐to‐Device (D2D). Energy efficiency algorithms are proposed for the communication between D2D users and cellular users (CUs) and, following the Lagrangian duality theory, an optimal power and rate control solution is given for D2D users, while satisfying the interference limits related to CUs. Finally, the new algorithm is used to achieve proportional fairness between D2D users and CUs and to show with numerical results that the interference to CUs can be limited to always be under a predefined threshold. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
38. IAMMAC: an interference-aware multichannel MAC protocol for wireless sensor-actor networks.
- Author
-
Kakarla, Jagadeesh, Majhi, Banshidhar, and Battula, Ramesh Babu
- Subjects
INTERFERENCE (Telecommunication) ,MULTICHANNEL communication ,COMPUTER network protocols ,WIRELESS sensor networks ,INFORMATION theory ,TELECOMMUNICATION channels ,COMPUTER simulation - Abstract
In this paper, we discuss an interference aware multichannel MAC (IAMMAC) protocol assign channels for communication in wireless sensor-actor networks. An actor acts as a cluster head for k-hop sensors and computes the shortest path for all the sensors. Then, the actor partitions the cluster into multiple subtrees and assigns a noninterference channel to each subtree. The actor 1-hop sensors are represented as relay nodes. The actor selects a relay node as a backup cluster head (BCH) based on the residual energy and node degree. After selecting a BCH from the relay nodes, the actor broadcast this information to the remaining relay nodes using the common control channel. The relay sensors use the same channel of BCH to communicate with it. However, the other cluster members do not change their data channel. Further, interference-aware and throughput-aware multichannel MAC protocol is also proposed for actor-actor coordination. The performance of the proposed IAMMAC protocol is analyzed using standard network parameters such as packet delivery ratio, goodput, end-to-end delay, and energy dissipation in the network. The obtained simulation results indicate that the IAMMAC protocol has superior performance as compared with the existing MAC protocols. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
39. Interaction between the predator Xylocoris sordidus and Bacillus thuringiensis bioinsecticides.
- Author
-
Santos, Nathália A., Ramalho, Dagmara G., Marques, Hortência M., Godoy, Joana D.S., De Bortoli, Caroline P., Magalhães, Gustavo O., Vacari, Alessandra Marieli, and De Bortoli, Sergio A.
- Subjects
BACILLUS thuringiensis ,DIAMONDBACK moth ,PREDATOR management ,PREDATORY animals ,BIOLOGICAL insecticides ,PLUTELLIDAE ,INTEGRATED pest control - Abstract
Xylocoris species (Hemiptera: Anthocoridae) are known to occur in various habitats and attack a diversity of agriculturally important prey. Other groups of organisms, such as strains of Bacillus thuringiensis Berliner (Bt) bacteria, also have been extensively studied and applied as biological control agents. The use of these Bt‐bioinsecticides in association with predators may be a good strategy in integrated pest management. This work had the objective to study predator behaviour, predatory capacity, and functional response of fifth‐instar nymphs of Xylocoris sordidus (Reuter) to eggs of Plutella xylostella (L.) (Lepidoptera: Plutellidae) and Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) treated with one of three commercial Bt‐bioinsecticides. The predator presented a type II functional response to untreated P. xylostella eggs (control) and to eggs treated with Agree, whereas the response was type III to P. xylostella eggs treated with Xentari and Dipel. However, on a diet of C. cephalonica eggs the predator displayed a type II response curve on eggs treated with each of the three bioinsecticides, and a type III response on untreated eggs. Bioinsecticides based on B. thuringiensis may be used in association with X. sordidus predators to control lepidopterous pest species. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
40. Strategies for ascertaining the interference of phase II metabolites co-eluting with parent compounds using LC- MS/ MS.
- Author
-
Tang, Caiming, Tang, Caixing, Zhan, Wei, Du, Juan, Wang, Zhifang, and Peng, Xianzhi
- Subjects
INTERMEDIATES (Chemistry) ,ORGANIC compounds ,LSD (Drug) ,PHARMACEUTICAL industry ,ELECTROLYSIS - Abstract
LC- MS/ MS is currently the most selective and efficient tool for the quantitative analysis of drugs and metabolites in the pharmaceutical industry and in clinical assays. However, phase II metabolites sometimes negatively affect the selectivity and efficiency of the LC- MS/ MS method, especially for the metabolites that possess similar physicochemical characteristics and generate the same precursor ions as their parent compounds due to the in-source collision-induced dissociation during the ionization process. This paper proposes some strategies for examining co-eluting metabolites existing in real samples, and further assuring whether these metabolites could affect the selectivity and accuracy of the analytical methods. Strategies using precursor-ion scans and product-ion scans were applied in this study. An example drug, namely, caffeic acid phenethyl ester, which can generate many endogenous phase II metabolites, was selected to conduct this work. These metabolites, generated during the in vivo metabolic processes, can be in-source-dissociated to the precursor ions of their parent compounds. If these metabolites are not separated from their parent compounds, the quantification of the target analytes (parent compounds) would be influenced. Some metabolites were eluted closely to caffeic acid phenethyl ester on LC columns, although long columns and relatively long elution programs were used. The strategies can be utilized in quantitative methodologies that apply LC- MS/ MS to assure the performance of selectivity, thus enhancing the reliability of the experimental data. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
41. Modelling the impact of interference on the energy efficiency of WLANs.
- Author
-
Xu, Chuan, Han, Zhenzhen, Wang, Qianyun, Zhao, Guofeng, and Yu, Shui
- Subjects
ENERGY consumption ,CO-channel interference ,COMPUTER network protocols ,WIRELESS LANs - Abstract
Summary: The high‐bandwidth demands from variety of applications drive a dense wireless local access network (WLAN), which results in a complicated wireless network scene with serious co‐channel interference and energy waste. In this paper, to reveal the interactions between interference and energy efficiency, we propose an interference‐energy efficiency (IFEE) model to quantify the interference impact on the energy efficiency of 802.11 access point (AP) devices. Firstly, we introduce the channel separation and the difference of received signal strength indication (D‐RSSI) as two indicators to extend the classical signal to interference plus noise ratio (SINR) notion and rate adaptive mechanism. Then, these two parameters are integrated into the energy consumption model to establish the IFEE model. Lastly, we conduct extensive measurements with five typical WiFi interference scene in real network to validate the effectiveness of our model. The comparisons between simulation results and real data demonstrate that the proposed IFEE model can quantify the interference and energy efficiency with high accuracy, which can be used for wireless network optimization and protocol design. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
42. An energy efficient medium access control protocol for target tracking based on dynamic convey tree collaboration in wireless sensor networks.
- Author
-
Wang, Yun, Shi, Peizhong, Li, Kai, and Chen, Zhikui
- Subjects
ACCESS control ,ENERGY consumption ,INTERNET protocols ,TREE graphs ,ELECTRIC interference ,WIRELESS sensor networks ,TIME division multiple access ,COMPUTER simulation - Abstract
SUMMARY Collisions and interferences among nodes pose a challenge for data aggregation in many applications, such as target tracking by adopting dynamic convey tree-based collaboration (DCTC). Because coordination with a time division multiple access (TDMA) medium access control (MAC) might provide an opportunity for better interference control, in this paper, we refine slot allocation to nodes in a dynamic convey tree and design an energy efficient MAC protocol called dynamic-time division multiple access (D-TDMA). The D-TDMA protocol avoids collisions and interferences and allocates contiguous active slots to nodes as far as possible during data aggregation from leaf nodes to a root node. As a result, energy consumption in switching from sleep to active state is saved. In comparison with Always-On scheme, theoretical analysis results show that the proposed protocol D-TDMA improves energy efficiency by up to 28.3% during one data aggregation. Furthermore, simulation results show that D-TDMA does not suffer from collisions and interferences among nodes in a dynamic convey tree and performs similar throughput to that of Always-On scheme. Because of its advantage of parallel and continuous scheduling among node pairs in the convey tree, D-TDMA outperforms efficient slot reservation in both energy efficiency and low delay because of to slot saving. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
43. Modelling and estimation for optimal treatment decision with interference.
- Author
-
Lin Su, Wenbin Lu, and Rui Song
- Subjects
- *
LONG-Term Evolution (Telecommunications) , *THERAPEUTICS , *MOBILE games - Abstract
In many network-based intervention studies, treatment applied on an individual or his or her own characteristics may also affect the outcome of other connected people. We call this interference along network. Approaches for deriving the optimal individualized treatment regimen remain unknown after introducing the effect of interference. In this paper, we propose a novel network-based regression model that is able to account for interaction between outcomes and treatments in a network. Both Q-learning and A-learning methods are derived. We show that the optimal treatment regimen under our model is independent from interference, which makes its application in practice more feasible and appealing. The asymptotic properties of the proposed estimators are established. The performance of the proposed model and methods is illustrated by extensive simulation studies and an application to a mobile game network data. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Doubly robust estimation in observational studies with partial interference.
- Author
-
Lan Liu, Hudgens, Michael G., Saul, Bradley, Clemens, John D., Ali, Mohammad, and Emch, Michael E.
- Subjects
- *
CHOLERA vaccines , *SCIENTIFIC observation , *REGRESSION analysis , *THERAPEUTICS , *DIMENSION reduction (Statistics) - Abstract
Interference occurs when the treatment (or exposure) of one individual affects the outcomes of others. In some settings, it may be reasonable to assume that individuals can be partitioned into clusters such that there is no interference between individuals in different clusters, that is, there is partial interference. In observational studies with partial interference, inverse probability weighted (IPW) estimators have been something else different possible treatment effects. However, the validity of IPW estimators depends on the propensity score being known or correctly modelled. Alternatively, one can estimate the treatment effect using an outcome regression model. In this paper, we propose doubly robust (DR) estimators that utilize both models and are consistent and asymptotically normal if either model, but not necessarily both, is correctly specified. Empirical results are presented to demonstrate the DR property of the proposed estimators and the efficiency gain of DR over IPW estimators when both models are correctly specified. The different estimators are illustrated using data from a study examining the effects of cholera vaccination in Bangladesh. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Construct a power-efficient and space-reuse-effective dominating set using small-world model in mobile ad hoc networks.
- Author
-
Jung-Shian Li, Yi-Ting Lin, and Tien-He Liu
- Subjects
AD hoc computer networks ,ENERGY consumption ,ENERGY management ,PROBABILITY theory ,ELECTRIC interference ,DATA transmission systems - Abstract
In this paper, we proposed a novel distributed power management and clustering scheme for a large scale of ad hoc networks. An inappropriate transmission power leads to high power consumption and interference, thus we introduce a power management and clustering scheme to maintain coverage and to minimize interference using the small world model that provides a good starting point to sustain connectivity. This scheme reduces number of relay nodes and relay packets by constructing the virtual backbone with clusters. Our proposed scheme divided a large contention domain into small ones. Owing to power management for each node, space reuse is effective. Furthermore, the power consumption is obviously reduced by our proposed scheme. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
46. Effect of noisy carrier reference signal and interference on performance of MSK receiver.
- Author
-
Stefanovic, Mihajlo C., Draca, Dragan Lj., and Vidovic, Aleksandra Z.
- Subjects
PHASE shift keying ,CARRIER control systems ,ELECTRIC interference ,PHASE modulation ,RADIO frequency modulation - Abstract
This paper considers the coherent detection of minimum shift keying signal and a degradation in error rate performance from ideal due to an interference and a phase discrepancy between the carrier of the received signal and the carrier of the receiver. The error rate is calculated for the simple receiver model with integrate-and-dump circuits. The reference carrier signal unsteadiness is presented by the probability density function of the first order non-linear PLL phase error, while the uncertainty due to an interference is involved in the system model with a random phase of cosine signal that accompanied the useful signal. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
47. STDGL3, a Reference Material for Analysis of Sulfide Minerals by Laser Ablation ICP‐MS: An Assessment of Matrix Effects and the Impact of Laser Wavelengths and Pulse Widths.
- Author
-
Belousov, Ivan, Danyushevsky, Leonid, Goemann, Karsten, Gilbert, Sarah, Olin, Paul, Thompson, Jay, Lounejeva, Elena, and Garbe‐Schönberg, Dieter
- Subjects
LASER ablation inductively coupled plasma mass spectrometry ,MATRIX effect ,REFERENCE sources ,MATERIALS analysis ,MINERAL analysis ,BORATE glass ,SILVER sulfide ,SULFIDE minerals - Abstract
A new reference material, STDGL3, for the calibration of in situ analyses of sulfide minerals by LA‐ICP‐MS has been developed and characterised. It represents a lithium‐borate‐based glass containing a mixture of Zn‐ and Fe‐sulfide concentrates doped with several chalcophile elements as well as Zr, Gd, Hf and Ta required for assessing common interferences on Ag, Au and Pt. STDGL3 has a wider range of elements and a better homogeneity compared with existing reference materials for LA‐ICP‐MS analysis of sulfides. Compositional variations for most elements are below 3% RSD, below 5% RSD for Ag, Au and Pt, and below 7% RSD for Se, when performing spot analyses with a 50 μm beam size. Its preparation recipe is reproducible allowing for multiple batches to be made. Use of STDGL3 significantly improves accuracy of sulfide mineral analysis by LA‐ICP‐MS when compared with use of other available reference materials. Performance of STDGL3 was evaluated using several different laser systems. No significant change was observed between 193 nm ArF excimer lasers with 5 and 20 ns pulse widths, but use of 213 and 248 nm lasers displays more systematic differences, especially when analysing galena. Correction coefficients are needed for some elements (Zn and Cd in particular) when analysing sulfide minerals using STDGL3 as a calibration reference material. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. P-53: Study on the Interface Between Passivation and Insulator Layer in TFT with Organic Process.
- Author
-
Zhao, Na, Shen, Qiyu, Shi, Gaofei, Xu, Xufei, Wang, Yijun, Song, Jie, Han, Jidong, Yin, Yangzhi, Chen, Dong, Che, Chuncheng, and Li, Chengkui
- Subjects
PASSIVATION ,SURFACE preparation ,PASSIVITY (Chemistry) ,ELECTRIC insulators & insulation ,CHEMICAL bonds - Abstract
This paper introduces a phenomenon named FPC peel off caused by the bad interference between passivation layer and gate insulator layer in TFT contained organic process. We investigated the relationship of this phenomenon with TFT array process and improved the interface characteristics through N2 Plasma and N2 flow skip in passivation deposition step. An optimized VIA hole design was also found which can achieve favourable FPC bonding condition. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
49. Interference suppression by adaptive beamforming of satellite-borne phased-array antennas.
- Author
-
Matsumoto, Yasushi, Tanaka, Masato, Kozono, Shinichi, Takahashi, Takashi, Huan-Bang Li, and Ikegami, Tetsushi
- Subjects
ANTENNAS (Electronics) ,TELECOMMUNICATION satellites ,ANTENNA arrays ,TELECOMMUNICATION systems ,TELECOMMUNICATION - Abstract
This paper describes adaptive beam formation of a satellite-borne antenna for suppressing the uplink interference in satellite communication. The S-band phased-array antenna installed on the Engineering Test Satellite-VI (ETS-VI) was used in this experiment. The beamforming network in the satellite was controlled from the earth through a TT&C link. It was found that the installed antenna could form a designed beam pattern. It was also found that the actual interference on the S-band intersatellite link could be effectively suppressed. © 1998 Scripta Technica, Electron Comm Jpn Pt 1, 81(11): 58–66, 1998 [ABSTRACT FROM AUTHOR]
- Published
- 1998
- Full Text
- View/download PDF
50. Strain Visualization in Flexible Sensors with Functional Materials: A Review.
- Author
-
Pancham, Padmanabh Pundrikaksha, Chiu, Wen‐Hsin, Mukherjee, Anupam, and Lo, Cheng‐Yao
- Subjects
STRAIN sensors ,SPORTS sciences ,THERMOGRAPHY ,DETECTORS ,PHOTONIC crystals ,MICROELECTRONICS - Abstract
Here, in comparison to indirect and nonvisualizable detections that usually convert strains from electrical signals, the strain sensors that show visible signals with operation simplicity and intuitive perception for practical applications in flexible, printed, and hybrid microelectronics are summarized. The sensors are categorized into four mechanisms of optical phenomena (diffraction, reflection, interference, and photonic crystal), fluorescent mapping (mechanochromism and mechanoluminescence), Moiré effect, and thermal imaging. In addition to their operating principles, three characteristics of sensitivity, dynamic window, and spatial resolution are examined. Furthermore, three types of strains (uniaxial, biaxial, and multiaxial) with subcategories in strain mode (tensile and compressive) and uniformity (isotropic and anisotropic) that are supported by corresponding sensors are also summarized here. With three potential applications and markets of healthcare and biomedical engineering, human motion detection (sports science), and roll‐to‐roll manufacturing listed at the end, a steppingstone is offered here for those who works or intends to work in this field by revisiting the outcomes from key literature published in recent years. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.