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The orthogonal time frequency space (OTFS) is a modulation designed to transmit data in high Doppler channels where the usage of the orthogonal frequency division multiplexing (OFDM) is challenging. The random padded OTFS (RP-OTFS) modulation, introduced recently, is an OTFS-like waveform optimized for more precise estimation of channel state information (CSI) and, in the case of integrated sensing and communication (ISAC), for radar detection as well. One of the main drawbacks of the RP-OTFS is the high level of interference between carriers (the inter-carrier interference—ICI) of Doppler-delay (DD) grid. In the article, we optimize the RP-OTFS waveform in terms of reducing the level of pilot-to-data interference and also offer a way to reduce the data carrier interference. The reduction in the pilot-to-data interference is achieved due to the introduction of the following: (1) redistributing interferences along the DD grid, and (2) special DD grid configuration. In turn, the reduction in data carrier interference is achieved by extrapolating the estimate of channel state information. The proposed approach allows us to reduce the influence of the interference component and, as a result, to improve the probability of correct demodulation in the ISAC RP-OTFS system. Various DD grid configurations for different use cases from a radar point of view are considered in the article. The questions of choosing appropriate values of the DD grid parameters depending on the operating environment are also discussed here. In simulations, the ICI-reduced RP-OTFS is compared with its predecessor, the regular RP-OTFS, and classical modulations: OFDM and zero-padded OTFS, and benefits of its usage are shown: lower bit error rate (BER) of the transmission and higher detection probability of the radar detection.

It has been recently shown that zero padding (ZP)-orthogonal frequency-division multiplexing (OFDM) is a promising candidate for 6G wireless systems requiring joint communication and sensing. In this paper, we consider a multiuser uplink scenario where users are separated in power domain, i.e., non-orthogonal multiple access (NOMA), and use ZP-OFDM signals. The uplink transmission is grant-free and users are allowed to transmit asynchronously. In this setup, we address the problem of time synchronization by estimating the timing offset (TO) of all the users. We propose two non-data-aided (NDA) estimators, i.e., the joint method of moment (JMoM) and the successive moment cancellation (SMC), that employ the periodicity of the second order moment (SoM) of the received samples for TO estimation. Moreover, the coding assisted (CA) version of the proposed estimators, i.e., CA-JMoM and CA-SMC, are developed for the case of short observation samples. We also extend the proposed estimators to multiuser multiple-input multiple-output (MIMO) systems. The effectiveness of the proposed estimators is evaluated in terms of lock-in probability under various practical scenarios. Simulation results show that the JMoM estimator can reach the lock-in probability of one for the moderate range of Eb/N0 values. While existing NDA TO estimators in the literature either offer low lock-in probability, high computational complexity that prevents them from being employed in MIMO systems, or are designed for single-user scenarios, the proposed estimators in this paper address all of these issues.

Code division multiple access in optical domain has a potential in next-generation long-haul transmission systems. However, multiple user interference is a snag in functioning of system employing OCDMA. A detailed analysis of multiple access interference (MAI) which causes a severe degradation in the system performance is done in this paper. An optimum MAI cancellation scheme has been proposed. This cancellation scheme depends not only on using the excellent correlation property of the double padded modified prime codes (DPMPC) as spreading sequence but also on employing minimum shift keying (MSK). The performance of the proposed cancellation scheme is compared with the existing techniques of FSK-OCDMA and PPM-OCDMA cancellation techniques. MSK-OCDMA cancellation technique achieves the lowest bit error rate of 10 . It is also efficient in power. It achieves lowest bit error rate at same number of mean photon number when compared to the existing techniques. The investigations reveal that MSK-OCDMA cancellation technique outperforms FSK-OCDMA and PPM-OCDMA cancellation schemes.

In this paper, we consider a multi-source decode and forward cooperative network coding (NC) relay system based on single-carrier zero-padded (SC-ZP) transmission scheme. All channels are L-tap frequency selective with Rayleigh fading. The cooperative maximum ratio combining (C-MRC) and the selection relaying combiners are applied and investigated at the destination, separately. We analyze the performance of proposed method in terms of symbol error probability at high signal-to-noise ratio regime, by adopting maximum likelihood (ML) and zero forcing (ZF) detectors. We prove that the considered system using the C-MRC and the ML detector, successfully exploits maximum achievable multhipath and cooperative diversity gain of 2L. To reduce the ML decoding complexity which increases with the number of sources, linear low complexity detection methods are used even though they usually do not succeed in collecting the receive diversity gain. We analytically demonstrate that proposed SC-ZP based NC system using the linear ZF detector achieves full diversity gain as like as the ML for arbitrary modulation schemes and number of sources. Moreover, an optimal NC mapping coefficients has been designed to maximize the system coding gain. Also, we extend proposed single relay NC system to multi-relay cooperative network. Single relay selection protocol is implemented based on a proposed selection criterion. In addition, simulation results illustrate that the proposed NC system employing SC-ZP technique and without need of any channel coding outperforms its competitors about 1 dB, also the processing time is reduced up to 80 percent.

In this article, compensation algorithms for zero padding are suggested to enhance the performance of deep convolutional neural networks. By considering the characteristics of convolving filters, the proposed methods efficiently compensate convolutional output errors due to zero padded inputs in a convolutional neural network. Primarily the algorithms are developed for patch based SRResNet for Single Image Super Resolution and the performance comparison is carried out using the SRResNet model but due to generalized nature of the padding algorithms its efficacy is tested in U-Net for Lung CT Image Segmentation. The proposed algorithms show better performance than the existing algorithm called partial convolution based padding (PCP), developed recently.

This paper proposes an area-efficient fast Fourier transform (FFT) processor for zero-padded signals based on the radix-2 2 and the radix-2 3 single-path delay feedback pipeline architectures. The delay elements for aligning the data in the pipeline stage are one of the most complex units and that of stage 1 is the biggest. By exploiting the fact that the input data sequence is zero-padded and that the twiddle factor multiplication in stage 1 is trivial, the proposed FFT processor can dramatically reduce the required number of delay elements. Moreover, the 256-point FFT processors were designed using hardware description language (HDL) and were synthesized to gate-level circuits using a standard cell library for 65 nm CMOS process. The proposed architecture results in a logic gate count of 40,396, which can be efficient and suitable for zero-padded FFT processors.

In this paper we introduce a successive interference cancellation (SIC) scheme for direct sequence optical code division multiple access (DS-OCDMA) systems using pulse position modulation (PPM). Considering double-padded modified prime code (DPMPC) as a signature sequence code, results show that the system has better performance in terms of both capacity and bit error rate (BER) as compared to the one without cancellation scheme, where the system with SIC scheme can support up to 88 users while the system without SIC scheme can support only 38 users at similar BER=10 . Although the receiver sensitivity is affected by the overlapping between users, which limits the system performance, the theoretical analysis of this issue indicates the influence of the size of PPM on OCDMA system. Hence, the BER value is still sufficient for good system performance.

We present and evaluate a protocol for the capture of otters (Lutra lutra) using padded leg-hold traps coupled with Global System for Mobile communication (GSM) trap alarms. The trapping method was highly efficient, capturing 46 otters at 6.9 trap-nights each. Functioning alarms allowed us to remove 36 otters from their traps within 22 (SD = 14) minutes of capture. We caught 10 otters in trap sets with malfunctioning trap alarms and retrieved them the following morning, after ≤24 hours. Functioning alarms reduced the injuries suffered from an average cumulative score of 77.7 to just 5.5 on the International Organization for Standardization 10990-5 trauma scale (Z = −5.074, P ≤ 0.001). As a result, we strongly encourage the use of GSM trap alarms under the principle of refinement in animal experiments.

HintergrundIm Rahmen der Kompressionstherapie beugen Polsterbinden Hautschädigungen vor, steigern die Adhärenz und unterstützen den Therapieerfolg. Da vergleichende Studien fehlen, wird ihre routinemäßige Verwendung diskutiert.Ziel der ArbeitDiese Studie untersucht Effektivität, Tragekomfort und Auswirkungen von Kompressionsverbänden mit und ohne Unterpolsterung.Teilnehmer und MethodenEs erhielten 61 venengesunde Probanden an einem Bein mit Watte- oder Schaumstoffbinden unterpolsterte und am anderen Bein gleichartige, nicht unterpolsterte Kurzzugkompressionsbandagierungen. Beidseits wurde ein Ruhedruck von 50 mm Hg erzeugt. Nach 60 min wurden Ruhedruck, Hautzustand, Tragekomfort, Schmerzen und Sitz der Versorgung beurteilt.ErgebnisseAlle Bandagierungen hatten nach 1 h Druckverluste, 82,0 % der nicht unterpolsterten einen Druckabfall von über 9 mm Hg. Sie erzeugten Schnürfurchen (100,0 %), starke Rötungen (77,0 %) und Druckstellen (42,6 %). Den Tragekomfort empfanden 3,3 % als angenehm, bei Schaumstoffunterpolsterung 83,9 % und bei Watteunterpolsterung 73,3 %. Nicht unterpolsterte Kompressionsbandagierungen erzeugten zu 62,3 % Schmerzen von 1–3 (Numerische Rangskala 0–10).DiskussionUnterpolsterte Kompressionsbandagierungen halten den therapierelevanten Anlagedruck besser, erhöhen den Tragekomfort und verursachen weniger Schmerzen und Hautprobleme als nicht unterpolsterte Kompressionsbandagierungen. Diese Aspekte sind entscheidend für Adhärenz und Therapieerfolg. Nach einstündiger Anwendung am gesunden Bein zeigten sich signifikante Unterschiede. Bei mehrstündiger Anwendung und vorgeschädigtem Gewebe ist von deutlich mehr Nebenwirkungen auszugehen. Daher sind Kompressionsbandagierungen grundsätzlich zu unterpolstern.

A large silk flag from the War of 1812, owned by the City of Toronto and held at the historic site museum of Fort York, was treated at the Canadian Conservation Institute (CCI) from 2011 to 2012. Several challenges were posed by the powdering condition of the silk, the extreme degree to which the flag was fragmented, and its large dimensions. In addition, the flag had previously been stitched between net and taped into a rudimentary pressure mount. Re-treatment was indicated for both physical and esthetic reasons. Image analysis was used to digitally separate the old restoration fabrics from the flag. This provided a much clearer picture of the flag's true condition before treatment. The previous restorations were reversed and the flag was encapsulated in net and pressure mounted using contemporary conservation grade materials and techniques. The rigid support consisted of an aluminum honeycomb panel covered with cotton flannel, needle-punched polyester, cotton display fabric, and custom-dyed cotton compensation fabric. A UV-filtering acrylic was selected for the glazing due to its anti-static, abrasion-resistant, and anti-reflection properties. Temperature and relative humidity sensors were incorporated into the mount, enabling continuous monitoring of the microenvironment within.