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Abstract: This article analyses the interferences in the quantification of traces of bisphenol S in paper by applying the direct analytical method “analytical pyrolysis gas chromatography mass spectrometry” (Py-GC/MS) in conjunction with on-line derivatisation with tetramethylammonium hydroxide (TMAH). As the analytes are simultaneously analysed with the matrix, the interferences derive from the matrix. The investigated interferences are found in the analysis of paper samples, which include bisphenol S derivative compounds. As the free bisphenol S is the hydrolysis product of the bisphenol S derivative compounds, the detected amount of bisphenol S in the sample may be overestimated. It is found that the formation of free bisphenol S from the bisphenol S derivative compounds is enhanced in the presence of tetramethylammonium hydroxide (TMAH) under pyrolytic conditions. In order to avoid the formation of bisphenol S trimethylsulphonium hydroxide (TMSH) is introduced. Different parameters are optimised in the development of the quantification method with TMSH. The quantification method based on TMSH thermochemolysis has been validated in terms of reproducibility and accuracy. [Copyright &y& Elsevier]

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]

In the 1960s, the demonstration of interference effects using two laser-beams raised the question: can two photons interfere? Its plausibility contested Dirac's dictum, "Interference between two different photons never occurs". Disagreements about this conflict led to a controversy. This paper will chart the controversy's contour and show that it evolved over two phases. Subsequently, I investigate the reasons for its perpetuation. The controversy was initiated and fuelled by several misinterpretations of the dictum. I also argue that Dirac's dictum is not applicable to two photon interference as they belong to different contexts of interference. Recognising this resolves the controversy. [ABSTRACT FROM AUTHOR]

• Develops interference-adjusted power learning curves with cognitive and motor components. • Cognitive and motor memory traces decay and follow power/exponential forms. • Compares developed and other models for experimental assembly data. • The developed approximate model fits the data the best. • Plateauing occurs because of slow (motor) learning and interference. Production and operations management (POM) uses learning curve (LC) models to determine the length of training sessions for new workers and predicting future task performance. Empirically validated LC parameters provide managers with quantitative information on the effects of the presumed factors behind the learning process. Previous studies considered LC to compose of cognitive and motor curves. Another widely acknowledged but only recently parameterized phenomenon in the POM field is interference, which assumes some loss of information or experience could occur over a learning session. This paper takes a logical step in this line of research by developing an interference-adjusted power LC model, a composite of cognitive and motor elements. This paper accounts for the decay of cognitive and motor memory traces from repetitions to measure the residual (interference-adjusted) experience and capture these phenomena. Three variants of the model are developed that assume power and exponential decay functions and an approximate version of the exponential one. Assembly data representing various forms of an individual learning profile have been used to test the fits of the developed models. In addition to those models, four potential models from the literature were selected for comparison purposes. The results show that the approximate model fits very well exponential learning profile. The findings highlight the confluence of the three phenomena in learning, component (cognitive/motor) learning, interference, and plateauing. [ABSTRACT FROM AUTHOR]

Multiple-input multiple-output (MIMO) antennas integrated with orthogonal frequency division multiplexing (OFDM) gains high interest due to its potential reduction on interference as well as efficient data transmission. However, the rapid growth of voluminous data and their diverse characteristics necessitate the effectiveness of error correction schemes in the recent past. The conventional error correction schemes suffer from its compatibility over the diverse data. Despite the concatenated error correction schemes meet the requirements, the precision remains uncertain under data and image transmission. This paper intends to develop an error correction scheme with the combination of Polar Coding (PC), which is an advanced coding scheme, and the renowned Convolution coding (CC). The competiveness of the proposed error correction scheme is experimented under extensive simulation constraints. Accordingly, this paper simulates MIMO-OFDM system with three antenna configurations (2 × 2), (2 × 4) and (4 × 4), which are subjected to experimentation under three modulation schemes such as Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (QAM)-16 and QAM-64. Three practical channel models such as Additive White Gaussian Noise (AWGN), Rayleigh and Rician channel models are used in the proposed study. The performance of the proposed coding scheme is compared against the traditional error correction schemes such as CC, Reed Solomon Code (RSC)-CC, Low-Density Parity Check (LDPC)-CC and turbo-CC. The study is also extended by transmitting the data as well as image to ensure the fairness on diversity of the data characteristics. The study discloses the effectiveness of the proposed error correction scheme over the conventional error correction schemes in terms of BER (Bit Error Rate) and PSNR (Peak Signal to Noise Ratio), when data and images are transmitted, respectively. The proposed method is compared with the conventional techniques and the results have shown that the PSNR performance of the proposed PC-CC method is 37.95% better than CC, 31.73% better than RSC-CC, 24.52% better than LDPC-CC and 14.12% better than turbo-CC method. [ABSTRACT FROM AUTHOR]

Wireless medical capsule endoscopy (WMCE) is an innovative technology that can be used to detect diseases of the human gastrointestinal tract. This technology utilizes a miniature camera capsule (CapCam) as a convenient alternative tool for treating small intestines with no pain and non-invasive method with very low levels of medical hazards compared to traditional methods. The CapCam technology operates in industrial, scientific, and medical (ISM) bands including 915 and 2400 MHz. However, co-channel and adjacent channel bands in the ISM bands are identified for mobile service, represented by long term evolution (LTE) system, on a primary basis (915 MHz) and a co-primary basis (2400 MHz) in the three ITU Regions. Such a condition creates a potential and mutual interference between the CapCam and LTE systems and it can highly affect human health. This paper proposes a model to study the potential interference scenarios between the CapCam and LTE systems in possible shared frequency bands for co-channel and adjacent channel scenarios based on a real urban macrocell (UMa) where line of sight (LOS) and non-LOS (NLOS) conditions are available. In this study, four propagation environment models are involved in estimating the total propagation losses including outdoor propagation, building penetration, indoor propagation, and propagation through a human body. The obtained results using the carrier to interference ratio (CIR), as a spectrum sharing criterion, showed that the interference from the LTE system is dominant. In addition, the concurrent operation of the CapCam and LTE systems with minimum distance seems more likely for the NLOS environment with higher frequency band (2400 MHz) and adjacent frequency scenario. Also, the channel capacity of the LTE and CapCam systems, under various CIR levels, displayed a good agreement with previous studies. [ABSTRACT FROM AUTHOR]

Maintaining a good trajectory and the transmission of signal towards the target, is a very delicate subject in the field of transmission. In particular, wireless transmission which is permitted on a sensible physical medium to guide the trajectory of the wave, is the greatest concern of radio transmission. Following this challenge, we propose approaches to the applicability of the Beamforming (BF) techniques and Convolutional Neural Network (CNN) on a signal received from an antenna array. The approaches consist of monitoring and driving the signal trajectory from the antenna output to the device target detecting and removing all interferences which may deflect the signal from the desired direction by pivoting it in another one (around 45 degrees). The work is based on experimentation with BF approaches such as the MVDR (minimum-variance distortionless-response), and the LCMV (linear-constraint minimum-variance) to optimize the transmission phase. We chose this BF technique above others because; the LCMV technique detects and reduces interference signals efficiently by utilizing calculated weight vectors to direct the powerful beam-based signal towards its intended target. The LCMV technique also ensure that each sensor outcomes are filtered with a finite impulse response (FIR) filter to satisfy narrow-band signal restrictions. For accurate signal transmission and reception with noise and interference suppression, LCMV seems promising. We use LCMV to cancel out interference and maintain the desired signal. When noise is not separable from the data (signal), an estimate of the sample covariance matrix is obtained from the data. Some approaches are taken to specify constraints, such as amplitude and derivative constraints. For example, specifying weights that suppress spurious signals from a particular direction while transmitting signals from a different direction without distortion. To avoid self-cancellation of signals, the LCMV permits multiple constraints to be placed along the target direction (directional vector). The last developed (marginal) approach is about the application of a 24-layer CNN model exploiting in depth all features and components of the Device-To-Device (D2D) signal. Three different sizes of convolution kernels are using (32, 64 and 128) to exploit the original signal which is noisy to remove the noise on the signal and to recover the desired signal. The scientific merit and novelty value of this paper is to allow us to analyse and understand how MVDR and LCMV filters identify and reduce interference in new expressions for their output signal-to-interference ratio (SIR) and signal-to-noise ratio (SNR). We showed the trade-off between noise reduction and interference rejection. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the performance of an intelligent reflecting surface (IRS) aided multiple-input single-output (MISO) wireless system in the absence of direct link. We focus on the practical scenario where the N reflecting elements of the IRS have a spatial correlation between them, and both the destination and IRS are subject to interferences. Moreover, the IRS design with discrete phase shifting is considered. In order to quantify the impact of spatial correlation, phase error and interference on the system performance, we provide closed-form and asymptotic expressions for the system outage probability. Additionally, approximations for the average channel capacity are also derived. To gain further insight, the achievable diversity gain of both partial and full correlation cases is quantified. The analytical and simulation results reveal that spatial correlation has a dominant effect and reduces the system diversity order, but it is beneficial to the average channel capacity. Phase error results in performance degradation. Interference degrades the system performance only by reducing the coding gain. Compared to the direct path, interference from the reflected path plays a major role in reducing the system performance. [ABSTRACT FROM AUTHOR]

Abstract In this paper we revisit the theory of selective reflection from a dilute vapor cell. A self-consistent theory is developed for reflection spectrum for Fabry–Perot interferometer. Formulas for single and multiple reflections are obtained. We also obtain the effective refractive index for a single selective reflection. The results of the paper are in a good agreement with existing experimental results. [ABSTRACT FROM AUTHOR]

Abstract Methods used to determine the aluminum coating thickness on polymer films may not measure the geometrical thickness directly but may instead measure the mass or other properties, thus leading to different thickness values. Common methods include the determination of evaporation rates using a quartz crystal microbalance (QCM) and the quantitative analysis of dissolved aluminum ions by inductively-coupled plasma mass spectrometry (ICP-MS), which provide mass thickness values. Alternatively, atomic force microscopy (AFM) and interference (INT) across the step of a partially removed aluminum layer yield geometrical values, and optical density (OD) and electrical resistance (ER) measure other properties. We compared the ability of these methods to determine the thickness of aluminum coatings applied to polyethylene terephthalate (PET) and paper by physical vapor deposition. We measured ER using four-point probes, five-point probes, and eddy currents. ER and OD achieved high precision but low accuracy, showing that the resistivity and absorption coefficients of thin aluminum layers can deviate from bulk constants. When the constant values were adjusted, both methods achieved higher accuracy. ICP-MS and QCM values were similar, when a geometrical model was applied, and in comparison AFM and INT showed low precision but high accuracy. When the aluminum was applied to paper instead of PET, only ICP-MS generated reliable results. In summary, the values derived using these different methods are only in agreement when method-specific constants such as absorption coefficients and resistivity are suitably modified. Highlights • Inductively-coupled plasma mass spectrometry is suitable as reference. • Atomic force microscopy and interference achieve low precision but high accuracy. • Electrical resistance and optical density achieve high precision but low accuracy. • Electrical resistivity declines as the aluminum layer gets thicker. • Optical density and resistivity are affected by the substrate under the aluminum. [ABSTRACT FROM AUTHOR]

Optical tweezers based on plasmonic nanostructure has a capability of limited and enhanced the light into subwavelength range so that they can manipulate smaller nano molecules such as protein, DNA. In the paper, we present the nanohole structure with an open microcavity can achieve to trap single biomolecules with high efficiency. The simulation results give the optimized structures which the bridge between the two reflective films of the microcavity is formed with ∼1 µm wide by Polydimethylsiloxane (PDMS) chamber. The experimental results show that the nanostructure with microcavity in inverted microscope optical tweezers system can trap effectively protein, DNA, and virus in the larger range than no cavity. The nanostructure presented in the paper has a promising prospect for high efficiently trapping small molecules and detecting biological solution in low concentration. [ABSTRACT FROM AUTHOR]

Stability is an important issue in order to characterize the performance of a network, and it has become a major topic of study in the last decade. Roughly speaking, a communication network system is said to be stable if the number of packets waiting to be delivered (backlog) is finitely bounded at any one time. In this paper we introduce a number of routing scheduling algorithms which, making use of certain knowledge about the network's structure, guarantee stability for certain injection rates. First, we introduce two new families of combinatorial structures, which we call universally strong selectors and generalized universally strong selectors , that are used to provide a set of transmission schedules. Making use of these structures, we propose two local-knowledge packet-oblivious routing scheduling algorithms. The first proposed routing scheduling algorithm only needs to know some upper bounds on the number of links and on the network's degree, and is asymptotically optimal regarding the injection rate for which stability is guaranteed. The second proposed routing scheduling algorithm is close to be asymptotically optimal, but it only needs to know an upper bound on the number of links. For such algorithms, we also provide some results regarding both the maximum latencies and queue lengths. Furthermore, we also evaluate how the lack of global knowledge about the system topology affects the performance of the routing scheduling algorithms. [ABSTRACT FROM AUTHOR]

Researchers face fundamental challenges applying the stochastic geometry framework to analysis of terahertz (THz) communications systems. The two major problems are the principally new propagation model that now includes exponential term responsible for molecular absorption and blocking of THz radiation by the human crowd around the receiver. These phenomena change the probability density function (pdf) of the interference from a single node such that it no longer has an analytical Laplace transform (LT) preventing characterization of the aggregated interference and signal-to-interference ratio (SIR) distributions. The expected use of highly directional antennas at both transmitter and receiver adds to this problem increasing the complexity of modeling efforts. In this paper, we consider Poisson deployment of interferers in ℜ 2 and provide accurate analytical approximations for pdf of interference from a randomly chosen node for blocking and non-blocking cases. We then derive LTs of pdfs of aggregated interference and SIR. Using the Talbot’s algorithm for inverse transform we provide numerical results indicating that failure to capture atmospheric absorption, blocking or antenna directivity leads to significant modeling errors. Finally, we investigate the response of SIR densities to a wide range of system parameters highlighting the specific effects of THz communications systems. The model developed in this paper can be used as a building block for performance analysis of realistic THz network deployments providing metrics such as outage and coverage probabilities. [ABSTRACT FROM AUTHOR]

This paper addresses the interference optimization problem for multicast/broadcast traffics in multi-radio multi-channel wireless mesh networks equipped with directional antennas. Since a directional antenna radiates the major of transmission power to the main-lobe, it can reduce the interference. However, this may increase the number of transmissions. The adaptive directional antenna is an effective tool in controlling the above-mentioned trade-off. The main goal of this paper is to linearly model the multicast/broadcast interference in the presence of directional antennas. In this regard, the authors provide a Mixed Integer Linear Programming (MILP) formulation named “Minimum Interference and Transmission Tree with Directional Antenna (MITT-DA)” to jointly select the best multicast/broadcast routing tree, antenna beam, and transmission channel. The proposed MITT-DA is a comprehensive model which supports both directional and omni-directional antennas. It not only considers wireless broadcast advantage, but also optimizes both inter-flow and intra-flow interferences. Numerical results demonstrate the efficiency of the proposed MILP scheme in terms of the interference and the number of transmissions. [ABSTRACT FROM AUTHOR]

This paper introduces a yokeless and contactless circular array current probe specifically designed for measuring current in an off-centered conductor. Unlike conventional approaches that require the current-carrying conductor to be centered within the circular array for optimal accuracy, the proposed method utilizes four magnetic sensors strategically placed on the circumference of a circular PCB. This unique configuration allows for precise current measurement even with an off-centered conductor of a smaller radius. To eliminate errors due to the off-centered conductor, there is a need for more sensors on the circular array by using the averaging method. The proposed method is independent of the conductor's position and diameter, ensuring accurate current measurements using only the circular array of four magnetic sensors. A functional prototype was constructed and subjected to laboratory testing, demonstrating the effectiveness of the proposed approach. In experimental setup, the proposed method's circular array current probe exhibited a current measurement error below 1%, affirming its reliability and suitability for practical applications. • A novel coreless circular current probe with four magnetic sensors ensures accurate measurements even with an off-center conductor. • The prototype's performance is assessed across various conditions, including different off-center positions and varying sizes of conductors. • The proposed method shows high accuracy, with less than 0.2% deviation in centered conductor measurements and errors below 1% in off-center positions and different conductor sizes, affirming the probe's reliability. • The probe demonstrates robust immunity to external magnetic field interference, with errors below 1%, affirming its efficacy for accurate current measurements in diverse applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The Cognitive Radio Network, incorporating Device-to-Device communication and a heterogeneous network, has garnered significant attention due to its ability to address spectrum shortage issues and optimize the efficient utilization of spectrum resources. However, resource allocation considering stochastic behavior has not been considered in existing studies. In this paper, our work aimed to maximize the throughput of the overall network considering multiple users under the umbrella of the Cognitive radio network assisted by amplify and forward relay. The constraints are treated as chance constraints with a probability of satisfaction in them, which leads to a non-convex mixed integer nonlinear problem which is an NP-Hard problem. To solve this problem an exhaustive search solution for optimal results is required. However, the computational burden always increases with the user equipment. Therefore, to obtain an optimal solution with having low computational burden, the Outer Approximation Algorithm is utilized in this research. To evaluate the desired results, extensive simulations have been carried out. The effectiveness of the proposed algorithm is verified by results in terms of throughput maximization under the impact of chance constraint formulation in the cognitive radio networks. [ABSTRACT FROM AUTHOR]

This paper proposes a technique for implementing the concept of a virtual chamber for radiation emission measurements in time domain. At present measurements for electromagnetic emissions are carried out either with FFT based analyzers or with a conventional-hybrid spectrum analyzer based on heterodyning where interested band of frequencies is swept in the radio frequency range in an anechoic chamber. This method requires a large measurement time especially for wide band frequency measurements; therefore such methods cannot guarantee reliable results in open area. The difficulty lies in the interference cancellation from random sources for prolonged measurement duration. In this paper time domain measurement technique for electromagnetic emissions at open area test site has been proposed, designed, implemented and tested in a laboratory environment. The proposed technique captures multichannel signal from interference sources and equipment under test (EUT) simultaneously on different antenna ports. The continuous signal streams sampled at a very high rate before being fed to the stochastic gradient based adaptive filter. This materializes the cancelation of interference generated by various electronic sources using advanced digital processing techniques. The factors influencing the exactness in estimating interference are discussed in detail and cancelation of interference over the range of frequency (DC-1 GHz) has been simulated. The simulation results exhibit how the proposed technique can revoke different kinds of interferences like continuous or transient, narrow or broad band. The performance evaluation of this method is verified through experiments conducted on real electronic appliances in open space environment and cross validated in an anechoic chamber up to 1 GHz. The outcome of the research demonstrates the cancellation of both generated as well as naturally existing random interfering signals in an urban site polluted with electrical noise. The results substantiate the accuracy and usefulness of this new method for the measurement of radiation emissions and electromagnetic compatibility in accordance with CISPR standards. Pre-compliance electromagnetic compatibility testing is realized with this work without the need of an expensive anechoic chamber and with a reduced measurement time compared to the conventional measurement system. [ABSTRACT FROM AUTHOR]

The problem of computing a connected network with minimum interference is a fundamental problem in wireless sensor networks. Several models of interference have been studied in the literature. The most common one is the receiver-centric, in which the interference of a node p is defined as the number of other nodes whose transmission range covers p. In this paper, we study the problem of assigning a transmission range to each sensor, such that the resulting network is strongly connected and the total interference of the network is minimized. For the one-dimensional case, we show how to solve the problem optimally in O (n 3) time. For the two-dimensional case, we show that the problem is NP-complete and give a polynomial-time 2-approximation algorithm for the problem. [ABSTRACT FROM AUTHOR]

The advancements in the home area networks call for wireless data transmission for continuous monitoring and taking control decisions to strengthen the smart grid technologies. The wireless sensor networks (WSNs) using Zigbee, WiFi operating in 2.4GHz frequency band play a key role in the data transmission. Because of coexistence in the same frequency band, there is a need for research to develop a mechanism for avoiding interference and proper encoding for precise data retrieval. In our prior work, we have presented a cross-layer multi-channel MAC (CMCMAC) [25] protocol for WSNs for estimation and avoiding interference. In this paper we propose an algorithm, Forward Error Correction (CMCMAC-FEC) encoding technique for improving the performance of CMCMAC in order to enhance reliability in communication of the data by ZigBee nodes to the specified destination under the influence of WiFi environment. In this paper, the CMCMAC-FEC model estimates the corrupted Zigbee packets and recovers the corrupted data packets at the destination accordingly maximizing the packet delivery ratio and throughput. The results attained illustrate the enhanced network performance. [ABSTRACT FROM AUTHOR]

In this paper, we propose and evaluate the performance of cognitive decode-and-forward (DF) generalized order relay selection network where the primary user (PU) receivers utilize orthogonal spectrums in the presence of interference. We consider a new scenario where the primary receivers utilize orthogonal spectrum bands and the spectrum of the primary receiver whose channel enhances the performance of the secondary system is shared with the secondary user (SU) nodes. Using orthogonal spectrum bands in cellular networks aims to reduce the interference between users as in the downlink transmission where orthogonal frequency bands are used by the base station (BS) in transmitting the data for the different users. The generalized order relay selection scheme is efficient in situations where the opportunistic relaying scheme could fail such as in conditions of imperfect channel-state-information, outdated channel information, and in cases where the best relay is busy in some scheduling and load balancing duties in other parts of the network. Closed-from expression is derived for the end-to-end (e2e) outage probability assuming Rayleigh fading channels. Furthermore, to get more insights about the system behavior, the performance is studied at the high signal-to-noise ratio (SNR) regime where the diversity order and coding gain are derived. Monte-Carlo simulations are given to verify the achieved results. The main results show that the number of primary receivers affects the system performance through affecting the coding gain and not the diversity order. Unlike the existing papers where the same spectrum band is assumed to be shared by the primary receivers with the secondary users, our findings demonstrate that increasing the number of primary receivers in the proposed scenario enhances the system performance. Finally, results illustrate that when the interference at the secondary relays or destination or at both scales with SNR, the system achieves a zero diversity order and a noise floor appears in the results due to the effect of interference on the system performance. [ABSTRACT FROM AUTHOR]

The modulation and projection of patterns are the cornerstones of spatially structured-light three-dimensional (3D) imaging. However, an overview of this field is lacking. This paper comprehensively reviews the modulation techniques for spatially structured-light 3D imaging. First, the frameworks and the state-of-the-art status of all the mainstream methods are introduced. Then, side-by-side comparisons are performed from different perspectives to illustrate their respective characteristics. In particular, experiments to compare the shape reconstruction quality of different methods were conducted. Beyond academic research, the applications and off-the-shelf products in the industry are reviewed. Finally, our views on the demands and trends in the field are presented. • Mainstream modulation devices for spatially structured-light 3D imaging are reviewed. • Valuable guidances in choosing suitable modulation devices are provided. • Experiments are conducted to compare the reconstruction quality of different methods. • Market-available structured light products are also comprehensively reviewed. [ABSTRACT FROM AUTHOR]

Universal Filtered Multi-Carrier (UFMC) system has been introduced as a candidate for the new generation. UFMC is a multi-carrier system, which can overcome challenges in wireless communications. In fact, the advantages of multi-carrier systems over single-carrier systems include higher bandwidth gain and higher robustness against frequency-selective fading. Generally, most multi-carrier systems suffer from notoriously sensitive to symbol-time offset (STO) and carrier-frequency offset (CFO). However, since UFMC systems utilize subband filters, sensitivity to CFO and STO can be reduced by designing efficient subband filters. In this paper, filter design problem is addressed in order to mitigate interference caused by effect of CFO in a multi-user UFMC (MU-UFMC) system under fair optimization framework. Since filter design problem is formulated as a non-convex optimization problem, we present two different approach in order to solve it. In the first approach, the formulated problem is relaxed so that one is converted to a standard second-order-cone programming (SOCP). In the second approach, we present a proposed algorithm with low complexity based on some lemma and relaxation. Then power allocation problem is solved to maximize the minimum achievable rate among all the users in a MU-UFMC system. The simulation results show the proposed schemes for filter design and power allocation outperform the benchmark schemes. [ABSTRACT FROM AUTHOR]

• LC-MS offers an alternative to invasive methods in the bone marrow to measure MRD in the blood of patients with MM. • This LC-HRMS responds to two objectives: overcoming the potential interference of biotherapeutics and assessing the MRD. • Highly sensitive and specific quantification of intact M-protein light chains in patient serum was achieved. To determine the disease status and the response to treatment for patients with multiple myeloma, measuring serum M-protein levels is a widely used alternative to invasive punctures to count malignant plasma cells in the bone marrow. However, the quantification of this monoclonal antibody, which varies from patient to patient, poses significant analytical challenges. This paper describes a sensitive and specific mass spectrometry assay that addresses two objectives: to overcome the potential interference of biotherapeutics in the measurement of M-proteins, and to determine the depth of response to treatment by assessing minimal residual disease. After immunocapture of immunoglobulins and free light chains in serum, heavy and light chains were dissociated by chemical reduction and separated by liquid chromatography. M-proteins were analyzed by high-resolution mass spectrometry using a method combining a full MS scan for isotyping and identification and a targeted single ion monitoring scan for quantification. This method was able to discriminate M-protein from the therapeutic antibody in all patient samples analyzed and allowed quantification of M-protein with a LLOQ of 2.0 to 3.5 µg/ml in 5 out of 6 patients. This methodology appears to be promising for assessing minimal residual disease with sufficient sensitivity, specificity, and throughput. [ABSTRACT FROM AUTHOR]

This paper focuses on how to avoid RF interference when deploying WiFi and IEEE 802.15.4/ZigBee radios simultaneously or in close proximity in indoor environments. The circumstances are particularly unfavorable for ZigBee networks that share the 2.4 GHz ISM band with WiFi senders capable of 10 to 100 times higher transmission power. However, the nature of ZigBee devices is to transmit small amount of data infrequently. Thus, we propose a solution for minimizing interference from WiFi, while limits ZigBee's occupancy rate. Another important point to be considered in this paper is that packet reception ratio (PRR) varies with the shape of crossing corridors. In general, there are typical shapes of’L’,’T’, and’+’ depending on crossing corridors. Thus, a mobile ad-hoc network topology must be configured to transmit wireless packets via intermediate nodes. The method to be proposed in this paper to avoid interference is the use of channel hopping. This channel hopping occurs by evaluating of two values on receiver node: the latest received signal strength (RSS) values and the received acknowledged packets (ACK). The minimum RSS value is given to –50dBm to guarantee a reliable transmission. Our experiment shows that a receiver node with PRR less than 65% cannot receive two or more consecutive ACK packets. The another method to be taken in this paper to increase PRR depending on the type of crossing corridors is to deploy intermediate nodes with the shortest distance to its neighbors. This method conducts an efficient topology of multi-hop ad hoc wireless network. [ABSTRACT FROM AUTHOR]

Wireless Multimedia Sensor Networks (WMSNs) have emerged as the new class of wireless sensor networks (WSNs) to meet the stringent Quality of Service (QoS) requirements of emerging applications. Multipath routing with cross-layer approach appears to be a potential solution for supporting the distinct characteristics of WMSNs. However, due to the broadcast nature of the underlying medium, multiple paths are exposed to inter-path interference. In addition, low-power wireless links are asymmetric, error-prone and unreliable in nature. Consequently, an accurate and stable link quality estimation is essential to guarantee the performance of routing protocol. This paper proposes Triangle link quality metric and minimum inter-path Interference based Geographic Multipath Routing (TIGMR) protocol which finds multiple node-disjoint paths in IEEE 802.15.4 compliant network. This cross-layer routing protocol selects forwarding node based on a triangle link quality metric, remaining energy, and distance while anticipating minimum adjacent path interference effect. In addition, TIGMR protocol avoids Hidden Node Problem (HNP) at the sink node without using Request-To-Send/Clear-To-Send (RTS/CTS) handshake mechanism. Simulation results indicate TIGMR protocol optimizes overall performance and improves network lifetime as compared with state-of-the-art Two-Phase Geographic Forwarding (TPGF) and Link Quality and Energy-Aware Routing (LQEAR) protocols. [ABSTRACT FROM AUTHOR]

The problem of bearing capacity of footings on rock is the subject of some researches in the recent years. However, the authors are not aware of any published paper about the effect of nearby footings on bearing capacity of rock foundations. This paper focuses on numerical analysis of the ultimate bearing capacity of two interfering strip footings resting on a rock mass, obeying the modified Hoek–Brown failure criterion. This criterion is applicable to intact rock or heavily jointed rock masses that can be considered homogeneous and isotropic. The rock mass was assumed to behave as a perfect plastic material and obeys an associated flow rule. The effects of Hoek–Brown parameters including geological strength index (GSI), material constant for intact rock ( m i ), and uniaxial compressive strength of intact rock ( σ ci ), on the bearing capacity of multiple footings were studied. For different clear spacing between the footings ( S ), the ratio of the failure load for an interfering new footing to that of a single isolated footing were determined. The results were compared with those available in the literature. [ABSTRACT FROM AUTHOR]

The development of measurement techniques capable to be used when the optical access is limited is critical for a large series of applications ranging from combustion to aeronautics. In this paper it will be shown that backward scattering glory can be used to measure droplet size in the micrometric range using a unique optical access. The goal of this paper is first to present the glory as a measurement technique and to develop a wave optic model capable to predict the diameter of a droplet from its glory pattern. Indeed the novelty of this work consists in the fact that, considering the edge rays as major contributors to the glory pattern generated by a spherical droplet, Young's fringe analogy can be directly used to determine its size. The model is numerically validated for droplet size ranging from 10 μm to 1 mm and it is applied to multiple droplets glory pattern. The simplicity of the wave optics model allows both a more straightforward interpretation of the physical phenomena and a quick implementation into data inversion algorithms. [ABSTRACT FROM AUTHOR]

• Interference of transition and Cherenkov radiation fields causes hybrid radiation. • Interference sets the range of the angular distribution with monochromatic X-rays. • Monochromaticity of Cherenkov X-rays is limited by transition radiation influence. • We predict a spectral asymmetry of hybrid radiation in the soft X-ray range. • Considered radiation geometry allows controlling X-rays spectrum and polarization. Vavilov-Cherenkov emission and transition radiation are the well-known phenomena and find a broad application for different scientific communities. In the case of simultaneous generation of both types of radiation, there is a possibility of interference between radiation fields. Thus, the emitted radiation could possess both transition radiation and Vavilov-Cherenkov radiation properties, that is why it should be considered as hybrid radiation. In this paper, we present the results of the theoretical investigation of X-ray hybrid radiation. Using the polarization current approach and the atomic scattering factor formalism to account anomalous dispersion of the complex permittivity we study spectral-angular distributions and polarization states of X-ray hybrid radiation when a charge obliquely falls on a foil. The theoretical results greatly contribute to understanding of X-ray Vavilov-Cherenkov radiation as well as the development of the X-ray narrow band radiation sources based on Vavilov-Cherenkov effect. [ABSTRACT FROM AUTHOR]

The picosecond optical Kerr gate is an effective method for the separation of long-lived laser induced interference from instantaneous Raman scattering. In this paper, an application of the Kerr-gated Raman spectroscopy in combustion environment was demonstrated. The fast gating provided by a Kerr effect based optical shutter extends Raman spectroscopy measurements to sooty flames and flames rich in polycyclic aromatic hydrocarbons. The optical setup of the Kerr gate is described in detail and the gating time, efficiency and spatial uniformity of the ultrafast shutter are reported. To demonstrate the concept, the Kerr-gated Raman spectroscopy was applied in a laminar CH 4 /air diffusion flame to evaluate the capability to extract a Raman spectrum under different interference levels. In the region deemed inaccessible with µs-gated Raman spectroscopy, the laser induced interference was effectively suppressed by the Kerr gate. A test was also conducted in a C 2 H 4 /air premixed flame to explore the limitation of the Kerr-gated Raman technique. The result shows that after combining with polarization separation, Raman spectra can be extracted from locations with 65 ppb soot volume fraction. [ABSTRACT FROM AUTHOR]

L'interprétation médicale d'un hémogramme nécessite un respect des exigences pré-analytiques et une maîtrise par le biologiste et le technicien de laboratoire des différentes technologies analytiques à sa disposition ainsi qu'une veille bibliographique régulière. Des problèmes pré-analytiques, interférences ou limites technologiques peuvent conduire à des résultats bruts erronés et à une mauvaise interprétation de l'hémogramme. Cet article présente différents pièges à éviter pour l'analyse des paramètres érythrocytaires selon notre expérience avec les analyseurs d'hématologie de la série XN (Sysmex). Medical interpretation of a complete blood count (CBC) requires the respect of the pre-analytical rules and a knowledge from the biologist of the analytical system at his disposal as well as a regular literature review. Pre-analytical problems, interferences or technological limitations may lead to wrong results and misinterpretation of the CBC.This paper presents various pitfalls to avoid for the analysis of red blood cells according to our experience acquired with the XN series hematology analyzers (Sysmex). [ABSTRACT FROM AUTHOR]

Abstract: More and more systems need to be squeezed together in frequency, space and time in order to satisfy the growth in demand for radio services. However, greater proximity increases the risk of service breakdowns caused both by poor interference tolerance in receivers and by inappropriate signals radiated by transmitters. In order to maximize the value of radio operation, a system view that facilitates trade-offs between receiver and transmitter performance is required. However, radio operation has traditionally been regulated using limits on transmitters, with few if any explicit constraints on receivers. This paper brings receivers into the regulatory picture by using harm claim thresholds, that is, interfering signal levels set by the regulator or spectrum manager that have to be exceeded before a receiving system operator can claim harmful interference; the specification of receiver performance (aka receiver standards) is left to manufacturers and operators. The paper explains how harm claim thresholds would be defined from both radio engineering and regulatory perspectives, and outlines how parameter values can be derived for television service and for a new allocation with cellular service in the adjacent band. Harm claim thresholds benefit both radio system operators and regulators by providing greater clarity about the entitlements that are entailed in assignments. They reduce business risk, and allow regulators to delegate both engineering design and boundary adjustment decisions to operators, thus allowing market forces to work more efficiently. These attributes will be particularly useful in bands with many, diverse and rapidly changing services and devices. [Copyright &y& Elsevier]

Abstract: Currently, Communication via Diffusion (CvD) is one of the most prominent systems in nanonetworks. In this paper, we evaluate the effects of two major interference sources, Intersymbol Interference (ISI) and Co-channel Interference (CCI) in the CvD system using different modulation techniques. In the analysis of this paper, we use two modulation techniques, namely Concentration Shift Keying (CSK) and Molecule Shift Keying (MoSK) that we proposed in our previous paper. These techniques are suitable for the unique properties of messenger molecule concentration waves in nanonetworks. Using a two transmitting couple simulation environment, the channel capacity performances of the CvD system utilizing these modulation techniques are evaluated in terms of communication range, distance between interfering sources, physical size of devices, and average transmission power. [Copyright &y& Elsevier]

L'interprétation médicale d'un hémogramme nécessite un respect des exigences préanalytiques et une parfaite maîtrise par le biologiste des différentes technologies analytiques à sa disposition ainsi qu'une veille bibliographique régulière. Des problèmes préanalytiques, interférences ou limites technologiques peuvent conduire à des résultats bruts erronés et à une mauvaise interprétation de l'hémogramme. Cet article présente différents pièges à éviter pour l'analyse des paramètres plaquettaires selon notre expérience avec les analyseurs d'hématologie de la série XN (Sysmex). Medical interpretation of a complete blood count (CBC) requires the respect of the pre-analytical rules and a perfect knowledge from the biologist of the analytical system at his disposal as well as a regular literature review. Pre-analytical problems, interferences or technological limitations may lead to wrong results and misinterpretation of the CBC.This paper presents various pitfalls to avoid for the analysis of the platelets according to our experience acquired with the XN series hematology analyzers (Sysmex). [ABSTRACT FROM AUTHOR]

• New receivers for time synchronization of MIMO systems in the presence of interference are proposed. • These receivers are compared with those of the literature from a performance and a complexity point of view. • The optimization of the number of transmitted antennas is investigated for deterministic and random channels. • Receivers of the literature without interference are compared in a unified framework with the GLRT1 receiver. The time synchronization of (M × N) MIMO systems has been studied this last fifteen years, for both single-carrier (SC) and multi-carriers links. Without any interference, most of the available receivers assume orthogonal sequences. With interference, the current most powerful receiver is a generalized likelihood ratio test (GLRT) receiver, assuming unknown, stationary, circular, temporally white and spatially colored Gaussian noise. However, this receiver is more complex than its non-GLRT counterparts, which, unfortunately, do not perform as well in most cases. In this context, the purpose of this paper is to get new insights into the time synchronization of SC MIMO links, both without and with interference, in order to overcome the limitations of the available receivers. In the absence of interference, the MIMO GLRT receiver is computed and compared to the existing ones in a unified framework, enlightening its better performance. In the presence of interference, as the complexity is an important issue in practice, several ways to decrease the complexity of the available GLRT receiver while keeping its performance are proposed, enlightening the great practical interest of the proposed schemes. Finally, the optimization of the number of transmit antennas is investigated, enlightening the existence of an optimal value of M depending on the channel matrix. [ABSTRACT FROM AUTHOR]

Abstract This paper presents the performance of multiuser diversity over mixed radio frequency / free space optical (RF/FSO) relay network in presence of co-channel interference at relay and destination nodes. The multiuser RF link between source-to-relay experiences Nakagami- m fading, while the FSO link between relay-to-destination is assumed to be affected by α − μ distributed atmospheric turbulence. Moreover, the amplitudes of the interfering signals at relay and destination nodes are assumed to follow independent Nakagami- m fading distribution. We consider both forms of optical demodulation schemes i.e., coherent detection and intensity modulation with direct detection (IM/DD) demodulation. Novel expression of the end-to-end cumulative distribution function (CDF) for the proposed mixed RF/FSO system has been derived which is further utilized to obtain the closed-form expression for outage probability and bit-error-rate of the overall system. Additionally, we present asymptotic expressions of outage probability and bit-error-rate to yield quick insights of the system performance. Finally, the numerical results are provided to examine the effect of various system parameters which are also supported by Monte-Carlo simulations. [ABSTRACT FROM AUTHOR]

In this paper, we consider a non-cooperative deployment of Long Term Evolution (LTE) and Device-to-Device (D2D) links, for which we derive approximations for Signal-to-Interference and Noise Ratio (SINR) distributions plus ergodic capacity expressions. We show that the capacities of D2D and cellular LTE systems w.r.t. their transmitted power ratios are concave and convex, respectively. We then propose two optimization approaches for the power allocation mechanism. In the particular case of major interference links, the convex concave procedure (CCCP) is proposed to obtain the optimal power ratio that satisfies the target quality of service. In an environment with multiple D2D links, we firstly generalize the CCCP approach and propose a resource association and power allocation algorithm. We then propose a lower complexity optimization approach that exploits the spatial statistics and correlation of the D2D and cellular links based on the Kriging interpolator to estimate the SINR distributions at each location. Finally, we present analytical and numerical results that demonstrate the effectiveness of the introduced algorithms, and we show that there exists an optimal power ratio that satisfies the transmission constraints in both D2D and cellular systems. [ABSTRACT FROM AUTHOR]

In this paper, a novel image encryption scheme based on quick response code and interference in Fresnel domain is proposed. The framework is asymmetric in nature due to amplitude- and phase-truncation operation of encoded spectrum. The input image is scrambled using Arnold cat map and divided into pixel blocks. Each block is encoded into a quick response code, which are then multiplexed to generate a binary matrix. The phase-truncated binary matrix is encoded into analytically generated two phase-only masks. During decryption the phase-only masks are recombined to yield the binary matrix, which is grouped into quick response codes and decoded into pixel blocks. The pixel blocks are recombined and descrambled to retrieve the original image. Numerical simulations have been carried out to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Abstract Graphene field-effect transistor (GFET) sensors are an attractive analytical tool for the detection of water pollutants. Unfortunately, this application has been hindered by the sensitivity of such sensors to nonspecific disturbances caused by variations of environmental conditions. Incorporation of differential designs is a logical choice to address this issue, but this has been difficult for GFET sensors due to the impact of fabrication processes and material properties. This paper presents a differential GFET affinity sensor for the selective detection of water pollutants in the presence of nonspecific disturbances. This differential design allows for minimization of the effects of variations of environmental conditions on the measurement accuracy. In addition, to mitigate the impact of the fabrication process and material property variations, we introduce a compensation scheme for the individual sensing units of the sensor, so that such variations are accounted for in the compensation-based differential sensing method. We test the use of this differential sensor for the selective detection of the water pollutant 17β-estradiol in buffer and tap water. Consistent detection results can be obtained with and without interferences of pH variations, and in tap water where unknown interferences are present. These results demonstrate that the differential graphene affinity sensor is capable of effectively mitigating the effects of nonspecific interferences to enable selective water pollutant detection for water quality monitoring. Highlights • An integrated differential graphene affinity sensor based on field-effect transistors. • First demonstration of the selective detection of analytes with nonspecific disturbances using a graphene sensor. • A compensation scheme reducing the impact of fabrication process and material property variations on differential sensing. • A compensation-based differential scheme for accurate nanosensing. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the effectiveness of cooperative broadcast in high-density linear networks is studied. In the considered protocol, a single source sends messages continuously causing interference among messages and the goal is to reach to the entire network via cooperating relays. Sufficient conditions for successful broadcast are derived under two different transmission schemes: the unidirectional scheme and the bidirectional scheme. Our analysis shows that the broadcast behavior depends on the pathloss exponent γ and the type of transmission scheme even though the channel between two nodes are affected by small-scale fading. Unlike the noncooperative multihop broadcast, the cooperative broadcast propagates the message to the entire network successfully when γ ≤ 1 provided that network parameters satisfy certain conditions. Furthermore, for γ > 1, cooperative scheme becomes optimal under the bidirectional transmission when the information rate is below a threshold; however if the transmissions are unidirectional, noncooperative scheme becomes optimal. When compared with 2D networks, we demonstrate that the advantages of cooperative broadcast in linear networks are limited. [ABSTRACT FROM AUTHOR]

Abstract Nowadays, with the explosive growth of users and devices, it is expected that new generation satellite system will support different communication demand around the world. Therefore, by increasing demand, hybrid satellite-terrestrial networks have been developed for achieving more coverage and capacity. Thus, in this paper, a LEO satellite constellation is deployed which includes LEO satellite systems and terrestrial equipment. Also, in order to manage the interference that is one of the main challenges in this network, Stackelberg game theory is used based on power control between LEO satellite systems and mobile users. To mitigate interference, two sub-games are provided based on pricing-based algorithm and convex optimization method. Finally, simulation results show that the performance of heterogeneous satellite network will be enhanced by the presented assumptions. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the outage performance of cellular two-way amplify-and-forward (AF) cooperative spectrum sharing systems in the presence of primary user (PU) network and multiple secondary user (SU) destinations. A general Nakagami-m fading environment has been used, where distinct fading parameters, as well as unequal average fading powers between the interference and relaying links, are assumed. Focusing on the cooperation process among the SU nodes and making use of the underlay cognitive approach, an approximate closed-form expression for the overall outage probability (OOP) of the secondary network is derived. In this analysis, an opportunistic scheduling and transmit antenna selection (TAS) algorithm in the secondary network has been employed. Considering the interference constraints due to the presence of PU receiver, power allocation of secondary user is done. The effects of fading severity, secondary network relay placement, the number of PU & SU transmit antenna, and number of SUs on the end-to-end system performance are examined through some representative numerical plots. Moreover, to minimize the secondary network OOP, we investigate the optimization problems of relay position. Monte Carlo simulation results are presented to corroborate the proposed analysis. [ABSTRACT FROM AUTHOR]

Abstract: Most papers in the field of optical phase retrieval either consider only the intensity (or amplitude) profile of the object under inspection (or scatterer location in the X-ray version), or a uniform tilt/rotation of the object beam. However, phase retrieval is able to recover the phase profile of the object (beam) as well, which theoretically makes the observable interference of phase retrieved object waves possible. In this paper we demonstrate this principle experimentally on centimeter sized deformable reflective objects (as large as 40mm by 40mm) and corresponding simulations are also presented. When the CCD camera is moved along the optical axis in the Fresnel region, the interference fringes of the displacement field have low contrast. On the other hand, when an imaging setup is built, and the camera moves near the image plane, high fringe contrast can be obtained. These fringes however suffer from some phase error. In our work the iterative modulus projection algorithm was used as a simply implementable phase retrieval method. [Copyright &y& Elsevier]

Résumé La biotine est utilisée librement à des doses fortes (≥ 10 mg) pouvant entrainer des problèmes d'interférence sur les dosages immunologiques. Le laboratoire doit maîtriser l'impact de cette interférence. L'objectif de l'étude a été, d'une part, d'évaluer in vitro le niveau d'interférence de la biotine sur l'automate Cobas 8000 e602®, Roche Diagnostics™ sur les résultats des marqueurs cardiaques, du bilan thyroïdien, des hormones gonadotropes, de la procalcitonine, des folates et de la vitamine BI2. D'autre part, d'évaluer in vivo chez des sujets sains, l'effet de la prise de biotine (5 mg, 3 fois par jour) pendant 5 jours sur les résultats du bilan thyroïdien. Les analyses ont été faites sur le Cobas e602® et sur l'automate Advia Centaur XP® (Siemens™). L'interférence in vitro de la biotine consiste en une sous-estimation des résultats pour les dosages en méthode sandwich et en une surestimation en cas de méthode par compétition. Une variation > 10 % est observée à partir d'une concentration en biotine de 20 ng/mL pour TnThs, TSH et FT4, de 30 ng/mL pour FT3 et PCT, et supérieure à 50 ng/mL pour les autres paramètres. L'étude in vivo montre une diminution des concentrations de TSH et une augmentation de celles de FT3 mais avec des évolutions différentes entre le Cobas® et le Centaur® suggérant un impact de la biotine dans les variations observées. Si la plupart des résultats des paramètres immunologiques réalisés sur Cobas e602® peuvent être affectés suite à un traitement du patient par de la biotine à des doses supérieures ou égales à 5 mg, 3 fois par jour, cet effet ne sera notable que pour certains paramètres, TSH, FT4, FT3, TnThs et PCT. Abstract Biotin is increasingly used freely at high doses (>I0 mg) that can cause interference problems with immunoassays. The laboratory must control the impact of this interference. This paper aims to evaluate, in vitro, the level of interaction of the biotin using the Cobas 8000 e602® Roche Diagnostics™ on cardiac markers, thyroid status, gonadotrophin hormones, procalcitonin, folate and vitamin BI2. Also, to evaluate the impact, in vitro, of the biotin intake (5mg / 3 times a day) for 5 days on the thyroid blood status for healthy subjects and using Cobas e602® and Advia Centaur XP® Siemens™. The in vitro assessment of the interaction of the biotin is an underestimation of the results for the sandwich method assays and to an overestimation of the results in case of use of a competitive immunoassay method. A bias of more 10% was observed from a biotin concentration of 20 ng/mL for TnThs, TSH, FT4, 30 ng/mL for FT3 and PCT and above 50 ng/mL for other parameters. Results of our in vivo study reflects the decrease ofTSH and the increase of FT3 concentrations with an important difference between Cobas® and Centaur® which would lead us to assert the impact of biotin. If the results of the immunology assays performed on Cobas e602® may be affected when patient is treated with biotin with doses equal or greater than 5 mg, 3 times a day, this effect will be noticeable only for certain parameters like TSH, FT4, FT3, TnThs and PCT. [ABSTRACT FROM AUTHOR]

Abstract This work addresses the fundamental problem of time-efficient reallocation of mobile random sensors to provide good communication within the network without interference. We consider n wireless mobile sensors with identical sensing range r initially randomly deployed on the [ 0 , ∞) according to the arrival times of the Poisson process with arrival rate λ > 0. The cost of individual sensor movement is proportional to the displacement to some power a ≥ 1. In this paper we discover and explain a threshold around the interference distance s = 1 λ and the sensing radius r = 1 2 λ for the maximum displacement to the power a to ensure coverage and to avoid interference. [ABSTRACT FROM AUTHOR]

Abstract Freeform surfaces used in molds and dies industries...etc. are machined on multi-axis CNC milling machines with the objective to achieve a good surface finish and a minimum machining time. For the finishing operation, Parallel Plane, Isoparametric, Z-Constant, etc. machining strategies are used. Z-Constant machining strategy is suitable for machining vertical or slant surfaces and deep cavities. In this strategy, cutting tool removes material on consecutive horizontal parallel planes which increases tool clearances and engagements and hence air cuts and machining times. Commonly, tool path is generated using a linear interpolation which makes tool movements discontinuous which creates vibrations that affect surface finish. To improve surface finish and to reduce machining programs sizes, tool path must be generated using continuous curves. In this paper, for finishing freeform NURBS surfaces on 3-axis CNC milling machines using ball cutters and Z-Constant machining strategy, an approach is proposed for determining the optimum tool avoiding interferences, optimizing the tool path by considering machining and geometric constraints. Finally, generation of One-Way or Zig-Zag tool path in terms of B-Spline curves by finding the minimum control points number producing the best tool positions approximation to achieve a good surface finish and a reduced machining program. This approach reduces the product development cycle, decreases machining times and costs and increases productivity. [ABSTRACT FROM AUTHOR]

Abstract Parts with sculptured surfaces used in molds industry, etc. are machined on multi-axis CNC milling machines. Their final shapes are obtained in three stages: roughing, semi-finishing and finishing. For all stages it is indispensable to determine largest cutters and thus most efficient cutters able to machine these surfaces without gouging and collision. Nowadays, Reverse Engineering is used to reproduce objects where their CAD models are unavailable. In this process, the object is digitized to retrieve a set of dense clouds of points. In consequence, there is no relationship between points which makes the determination of optimal cutters more difficult. In this paper, for finishing sculptured surfaces on 3-axis CNC milling machines directly from 3D cloud of points, an approach is proposed to partition the cloud of points into distinct regions from estimated points local shapes (concave, convex, plane, concave developable, convex developable, saddle) and then determines the optimal ball cutter for each region avoiding interferences. For this, Delaunay triangulation is used to establish geometric relationships between points. This approach reduces the product development cycle by associating an optimal cutter to each region which decreases machining times and costs and increases productivity. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an improved reflective computer vision technique, which is based on the optical interference. The improved technique eliminates the use of the computer-generated and monitor-display fringe pattern in the traditional reflective computer vision method. Instead, an optical interference fringe pattern having an analog resolution is produced by a two-point source of coherent light; hence, the fringe phase determination is no longer subjected to the depth resolution of the computer-monitor. With the use of higher gray-level image digitizers, the sensitivity of the fringe phase determination would be proportionally increased. In this paper, the principle and the instrumentation of the improved technique are presented. In addition, experimental demonstration of the improved technique in the non-destructive evaluation field is also included. [Copyright &y& Elsevier]

Abstract: Complex phenomena, such as the wave propagation in a medium, are thought to require highly sophisticated machineries for understanding their mechanics. In this paper, two wave phenomena, diffraction and interference, are implemented using solid modeling operations. The geometric model for the waves from a source is a cone. A trimmed cone is the DIFFERENCE between a cone and the given boundary. The wave propagation is modelled by the UNION of the cones (or trimmed cones). The intellectual contribution of this paper is on the dynamics of interface evolution. It answers the question of how a symmetric wave in the near field becomes asymmetric in a field far from the source. The analytical contribution is on the algebraic and geometric structures. Seemingly complex phenomena can be modelled with set operations on simple geometry such as cones. [Copyright &y& Elsevier]

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Analytical and numerical solutions of the undrained load-carrying capacity of shallow foundations are mainly available for single foundations. This paper investigates the undrained limit states of two-spaced rectangular foundations with rigid connections. Three-dimensional finite-element analyses are carried out to systematically examine the coupled interaction of foundation spacing and degree of soil strength heterogeneity on the load-carrying capacity of the foundation systems under general loading. Results are presented in the form of ultimate limit states under pure vertical (V), horizontal (H), and moment (M) loads, and the failure envelopes under combined V-H, V-M, H-M and V-H-M loading. Soil failure mechanisms obtained from the finite-element analyses are shown for the representative loading paths of the two-foundation systems. Based on the failure mechanisms, the methods are established for calculating the undrained load-carrying capacity of the two-foundation systems to assist the foundation design in practice. [ABSTRACT FROM AUTHOR]