esa-sceva/satcom-chunk-collection huggingface dataset:
# Research on Penetration Loss of D-Band Millimeter Wave for Typical Materials
## 2 Materials and Methods
The horn antenna operates from 110 GHz to 170 GHz with a gain of 25 dBi and a half-power beamwidth (HPBW) of 9\({}^{\circ}\) in the E-plane and 10\({}^{\circ}\) in the H-plane. The sensitivity of the receiver is \(-56\) dBm. The photos of the experimental setup at the transmitter and receiver are shown in Figure 5.  
This measuring D-band system is implemented in an indoor environment. It is carried out in the underground garage of Building 2, Jiangwan Campus, Fudan University. The antenna height of the transceivers is 1 m, the distance between them is 100 m, and the angle is horizontally aligned. We used a laser pointer to ensure that the antennas on the Tx-side and Rx-side are aligned. First, no obstructions are placed between the transceivers, and the signal power received without obstruction is measured, so that it can be used as a benchmark. Then, the occluders (the details about the occluders are shown in Table 3) are artificially placed in the space, and the position of the occluders is continuously adjusted to minimize the power loss, so as to complete the calibration. We repeat the measurement of the same parameter 10 times at each frequency point to improve the measurement accuracy, and take the average value as the measurement result at that point. Finally, the received signal power through different obstacles is subtracted from the reference value to obtain the penetration attenuation mainly caused by the obstacles. In order to compare the transmission loss of different materials, the occluders were manually replaced to obtain different transmission loss results. \begin{table}
\begin{tabular}{c c} \hline \hline
**Product Type** & **D-LNA 110-170 30 6** \\ \hline
**RF frequency (GHz)** & 110-170 \\
**Waveguide designator** & WM-1651 (WR-6.5) \\
**Gain (typ.) (dB)** & 30 \\
**Noise figure (dB)** & 6 \\
**P1 dB (dBm)** & \(-3\) \\
**Max RF input power (dBm)** & \(-30\) \\
**Part-no.** & 03000025 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The parameters of LNA. Figure 4: Block diagram of the D-band millimeter-wave transmission experiment system. Figure 5: The photos of the experimental setup at the transmitter and receiver. Figure 6 is a schematic diagram of the relative positions of the occluders and the transceivers in the experiment, including vegetation, a wood board, regular single-layer glass and slate materials. The vegetation includes potted green plants in the laboratory. When the number exceeds one pot, all the green plants are stacked together, as shown in Figure 7.
# Methods for Underwater Gravity Measurement Error Compensations Based on Correlation Analysis
## 4 Discussion and Conclusions  
The accuracy of gravity measurement is not only related to the errors that can be modeled but also to non-model errors caused by different dynamics. In general, the worse the dynamics, the worse the gravimetric results. The survey line SHEW2-2 in the experiment kept retracting the cable due to the sea state to prevent the depth of the towed body from touching the bottom, which was difficult accept in high-precision dynamic gravity measurements. If only the influence of model error is considered, the accuracy of gravity results will relatively decrease. Via the non-model error compensation correction method proposed in this paper, the fluctuation of the gravity measurement results is smaller, and the inner coincidence accuracy of the measurement line SHEW2 improved from 1.15 mGal to 0.73 mGal.  
For measuring line SHEW1, the overall motion process is relatively stable, and the inner conformity accuracy is slightly improved after compensation, but the effect is not very obvious, and the accuracy increased by 0.07 mGal. This is because our method only deals with the non-model error caused by the dynamic, and the worse the dynamic, the better the effect will be. Compared with traditional methods that only consider model errors, the method in this paper further considers methods for confronting non-model errors caused by high dynamics, which is common in underwater gravimetry. The accuracy of the two survey lines improved regardless of whether the dynamics is good or bad. This also provides us with ideas for dealing with other measure environments such as aerial, vehicular, and shipborne gravity measurements. Similar results can be obtained by our method for each measure environment.  
Figure 8: Gravity-measurement results for survey line SHNS2 before and after compensation.  
Figure 7: Gravity-measurement results for survey line SHNS1 before and after compensation.  
Aiming at gravity measurement errors, which cannot be modeled due to poor carrier dynamics in underwater gravimetry, our paper proposes an underwater gravimetry error compensation method based on correlation analysis. Experimental data show that this method can well compensate gravity measurement errors related to dynamics and improve the accuracy of gravimetry. In terms of engineering, our research largely compensated for the dynamic error of underwater gravity measurements caused by men or the environment and improved the experimental efficiency.
# Building Scalable and Secure Multicast Delivery Infrastructure in a Local Area Network
## 5 Conclusions and Future Directions  
In this paper, we proposed the use of pseudo-identity based encryption along with core-based tree architecture to create a secure multicast delivery mechanism in a corporate LAN. As we discussed in the previous section, our proposed architecture is immune to a number of security attacks that are possible through the use of the existing methods. Our system can be used efficiently for the following applications:  
* The secure multicast established through our proposed system can be used to deploy OS updates, patches, and device updates, including the update of new configuration. Since the messages are digitally signed, only the legitimate server can perform this operation.
* Routing protocols like RIPv2 and OSPF can effectively use this tree to send their route updates to other routers in the network.
* In our earlier paper [1], we proposed PrECast architecture to provide an efficient crypto-free solution to a number of LAN based attacks that are due to IPv4 broadcasting. PrECast assumes the existence of a secure multicast tree in the LAN. In this paper, we propose a secure multicast mechanism to close the gap.  
Conceptualization, writing--original draft preparation, P.V.; investigation, D.H.; supervision, writing--review and editing, E.P.  
This research received no external funding.  
The authors declare no conflicts of interest.
# An FPGA-Based Four-Channel 128k-Point FFT Processor Suitable for Spaceborne SAR
## 2 Fast Fourier Transform (FFT) Operation Analysis and Principle Introduction  
In a SAR imaging system, FFT processing undertakes most of the calculation work. Taking into consideration the desire to save hardware resources and reduce processing delay, the proposed FFT processor in this study, uses the radix-23 and mixed-radix algorithms.
# Damage Imaging in Lamb Wave-Based Inspection of Adhesive Joints
###### Abstract  
Adhesive bonding has become increasingly important in many industries. Non-destructive inspection of adhesive joints is essential for the condition assessment and maintenance of a structure containing such joints. The aim of this paper was the experimental investigation of the damage identification of a single lap adhesive joint of metal plate-like structures. Nine joints with different defects in the form of partial debonding were considered. The inspection was based on ultrasonic guided wave propagation. The Lamb waves were excited at one point of the analyzed specimen by means of a piezoelectric actuator, while the guided wave field was measured with the use of a laser vibrometer. For damage imaging, the recorded out-of-plane vibrations were processed by means of the weighted root mean square (WRMS). The influence of different WRMS parameters (i.e., the time window and weighting factor), as well as excitation frequencies, were analyzed using statistical analysis. The results showed that two-dimensional representations of WRMS values allowed for the identification of the presence of actual defects in the adhesive film and determined their geometry.  
adhesive joint; single lap joint; non-destructive testing; damage identification; Lamb waves; scanning laser vibrometry +
Footnote †: journal: Applied Mechanics and Physics Letters
## 7 Conclusions and Future Work  
This paper described a set of tools to support autonomous media production with multiple drones. We contributed with an XML-based language for shooting mission description. The language builds upon new concepts, such as events, shooting actions, or shooting roles, to create media production missions. High-level cinematography principles and different shot types can be implemented. Our language has proved to be flexible and adaptable enough to describe current cinematography operations, as new shots and parameters can easily be incorporated. Moreover, the system is able to bridge the gap between common vocabulary from editorial teams and robotics planning tools. We also contributed with our Dashboard, a graphical tool to support the editorial crew creating and executing shooting missions. The Dashboard has been designed to be intuitive and simple, and users can define complex shooting missions by navigating through a few configuration pages, describe shot geometry by clicking on aerial maps, and validate and execute plans for the missions. This tool generates XML files that can be interpreted by our Mission Controller, to compute mission plans and execute them.  
Our system has been integrated and tested in a realistic simulator and during experimental media production with actual drones. As future work, we plan to explore the combination of more complex multi-camera shots to assess the capabilities of multi-drone teams for media production from an artistic and editorial point of view.  
Conceptualization, A.T.-G., J.C., M.M., F.N., and A.M.; software and validation, A.M.-R., A.T.-G., M.M., and S.M.; writing and editing, A.T.-G., J.C., M.M., and S.M.; supervision, F.N., A.M., and A.O.; funding acquisition, A.M. and A.O. All authors have read and agreed to the published version of the manuscript.  
This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 731667 (MULTIDRONE). This publication reflects the authors' views only. The European Commission is not responsible for any use that may be made of the information it contains.  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} CRUD & Create, Read, Update and Delete \\ CTZ & Control Zone \\ GNSS & Global Navigation Satellite System \\ GUI & Graphical User Interface \\ HTML & HyperText Markup Language \\ HTTP & HyperText Transfer Protocol \\ IMU & Inertial Measurement Unit \\ KML & Keyhole Markup Language \\ RT & Reference Target \\ RTK & Real Time Kinematic \\ SA & Shooting Action \\ SAS & Shooting Action Sequence \\ SITL & Software In The Loop \\ SR & Shooting Role \\ UAV & Unmanned Aerial Vehicle \\ UML & Unified Modeling Language \\ XML & Extensible Markup Language \\ \end{tabular}
# Influence of Polymer Types on the Mechanical Properties of Polymer-Modified Cement Mortars
## 6 Conclusions  
The tests conducted in this study aimed to clarify whether the addition of polymers affects the mechanical properties of polymer-modified cement mortars. Four commercial polymers, namely, AC, PVA, SBR, and EVA, were incorporated into a cement mortar with two different cement replacement ratios. The compressive, flexural, and pull-off bond strengths were measured, and the relationships between the measured strength values were investigated. Based on the test results and comparisons, the following conclusions can be made:  
1. The present study indicated that polymer addition in a cement mortar resulted in the improvement of the compressive, flexural, and pull-off bond strength.
2. Polymers investigated in this study showed a stronger influence on the flexural strength rather than the compressive strength. Strong correlations between the compressive and flexural strength were observed.
3. Strong relationships between the flexural and pull-off bond strength were observed especially at seven days (\(R^{2}=0.81\)) as compared to 28 days (\(R^{2}=0.50\)).  
Based on the results of the pull-off bond tests, the failure modes of the PCM samples were transferred from the mortar failure to the interface failure with an increase in curing time.
5. The PCM sample containing EVA generally showed the best performance, with up to 33% and 63% increases in 28-day compressive and flexural strengths, respectively.  
The findings of this study are limited to the polymer dosage of 3% adopted, and different dosages might significantly change the performance of produced PCMs. Therefore, the ranking of the polymers investigated in this study should not be regarded as a general ranking for the effect of these polymers on the PCMs. Further studies might be necessary to determine the optimum type of polymer and cement replacement ratios for various RC structures, because the performance of the PCM can vary depending on several factors, including curing conditions, properties of the polymer, and interface preparation. In this study, all experiments and measurements were conducted under constant laboratory conditions. However, further experimental studies may consider the comparisons between the test results obtained in the laboratory and performance under real conditions.  
Conceptualization, M.O.K.; methodology, M.O.K.; validation, M.O.K.; investigation, M.O.K.; resources, M.O.K.; data curation, M.O.K.; writing--original draft preparation, M.O.K.; writing--review and editing, M.O.K.; visualization, M.O.K.; supervision, M.O.K.; project administration, M.O.K.; funding acquisition, M.O.K. This research was funded by the Korea Institute of Ocean Science and Technology (KIOST), KIOST project number PE99833.  
The experimental testing was carried out with the Department of Civil and Earth Resources Engineering at Kyoto University in Japan. The author would like to thank [PERSON] and [PERSON]. Some polymers were supplied by the Sumitomo Osaka Cement.  
The authors declare no conflicts of interest.
# Artificial Intelligence in Ophthalmology: Advantages and Limits
## 5 AI and Different Applications in Ophthalmology and Other Fields
### Precedents  
A study was conducted in which a CNN was trained to assess brain MRIs of low- and high-grade glioma patients to forecast genotypic features [123]. The application independently predicted both IDH1 and -2 gene mutations and MGMT gene methylation status with 94% and 83% accuracy, respectively. For a condition like glioma, the discovery of the genotype is crucial for suitable treatment.  
Likewise, six different genetic mutations in lung adenocarcinoma--STK11, EGFR, FAT1, SETBP1, KRAS, and TP53--could be foreseen, with AUCs ranging from 0.733 to 0.856 when pathological images were analyzed [124]. This analysis can be implemented for any kind of cancer, including eye cancers.  
Inherited Retinal Disorders (IRD)  
IRD is an area of active development for DL systems.  
Through modern sequencing, more than 250 genes and 300 loci implicated in retinal dystrophies have already been detected, laying the groundwork for evolving gene therapies and pharmacological agents [125].  
Combined genetic and clinical studies associated morphological characteristics with specific genes in different retinal dystrophies, such as ABCA4, RP1L1, and EYS.  
Ref. [125] describes the development of deep neural networks to precisely foresee causative genes in macular dystrophy (ABCA4 and RP1L1) compared to those in retinitis pigmentosa (EYS) by means of spectral domain on optical coherence tomography (SD-OCT) images. The study gave an overall average test precision of 90.9%, with individual category accuracies of 100% for ABCA4, 78% for RP1L1, 89.8% for EYS, and 93.4% for normal subjects.  
AI systems in IRD and other specialties are proving their value by linking genetic prediction to clinical settings. These applications are very useful for conditions where specific expertise is limited, such as in IRD. Genetics will be incorporated into general screening to increase the value of clinical diagnoses.
## 3 Materials and Methods
### Datasets
#### 3.1.3 Ancillary Data  
Supplemental datasets cover the road network, the footprint of buildings, and zoning information, which are available in the shape file format on the official website of the city of Bandung government [22]. It is important to clarify that these datasets were utilized to enhance the reference data rather than serving as direct inputs for the deep learning algorithm employed in the analysis.  
The first of these additional datasets pertains to the road network derived from the neighbourhood road database as of 2021. This dataset includes a shape file accompanied by attribute tables that provide detailed information on road length, width, condition, type, and section codes. The insights gained from road condition data are instrumental in identifying suitable locations for SVI downloads and facilitating the slum classification assessment process.  
The second dataset focuses on the density of the buildings as described in The Spatial Planning and Detailed Plans of Bandung City [18]. This shape file provides critical information regarding the area of each building, the total number of buildings, and the density expressed in units per square meter. These data are essential to compare the density of the buildings with the official 2020 slum reference map, which has been validated by the West Java Regional Settlement Infrastructure Agency.  
The third piece of supporting evidence derives from a survey conducted in 2024, which focused on potential housing and slum areas, adhering to the indicators and procedures established for slum verification as outlined in Indonesian regulations. Specifically, this includes the Regulation of the Minister of Public Works and Public Housing Number 14 of 2018 and the Circular Letter of the Minister of Public Works and Public Housing Number41 of 2021. The data obtained from this survey were instrumental in refining the slum reference layer, thereby delineating zones characterized by illegal occupancy. Consequently, residential structures within these designated areas often develop informally, contributing to the expansion of larger slum environments.
## 4 Conclusions  
In this paper, we focused on the time-domain characteristics of the signal and the offset effects on the signal. To save training resources and achieve the light weight of the model, we proposed a cascaded double-layer GRU network based on learnable correction modules, which can learn frequency and phase offset parameters. The double-layer GRU network can effectively use the time-domain characteristics of signals on the basis of minimal parameters. The results show that a reasonable tradeoff between the accuracy and the computational complexity can be achieved. The highest accuracy is up to 93.79% when SNR equals 18 dB, and the highest computational complexity has decreased by nearly 98%. The suggested approach offers a compelling technique for modulation identification.  
We can keep reducing the model's parameters in future work and investigate the connection between the recognition accuracy and the number of parameters that are explicitly lowered.  
Data curation, Y.L. and B.G.; funding acquisition, S.Z.; investigation, B.G. and H.Z.; methodology, S.Z. and W.Y.; supervision, S.Z. and B.G.; validation, B.G. and S.Z.; writing--original draft, B.G.; writing--review and editing, B.G. and S.Z. All authors have read and agreed to the published version of the manuscript.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Model**} & \multirow{2}{*}{**Parameter**} & \multicolumn{2}{c}{**Training**} & \multicolumn{2}{c}{**Training**} & \multicolumn{2}{c}{**Highest**} & \multicolumn{1}{c}{**Average**} \\  & & **Time (s)** & **Epoch** & **Accuracy** & **Accuracy** \\ \hline CGDNN [14] & 71, 742 & 33 & 101 & 93.33 & 63.82 \\ MCNET [16] & 121,226 & 46 & 107 & 91.25 & 61.95 \\ CGDNET [17] & 124,676 & 40 & 157 & 93.24 & 63.34 \\ MCLDNN [18] & 406,070 & 90 & 69 & 93.68 & 63.78 \\ DAE [19] & 1,063,642 & 39 & 228 & 91.63 & 62.13 \\ IC-AMCNET [20] & 1,263,882 & 34 & 233 & 90.01 & 60.65 \\ RESNET [21] & 3,098,154 & 131 & 275 & 90.48 & 60.12 \\ DENSENET [21] & 3,282,474 & 189 & 298 & 93.27 & 63.67 \\ Proposed & 49,606 & 174 & 134 & 93.79 & 64.34 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Comprehensive comparison of performance evaluation of different models.  
Figure 12: Parameters contrasted with other mainstream methods.  
This work was supported in part by the Natural Science Foundation of Tianjin under Grant 19 JCYBJC16100, and in part by the Tianjin innovation and entrepreneurly training program under Grant 202210060027.  
Not applicable.  
**Data Availability Statement**: The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors declare no conflicts of interest.
# Fast Temperature Field Extrapolation Under Non-Periodic Boundary Conditions
## 5 Conclusions  
We have developed a traditional proper orthogonal decomposition method, based on which, further extrapolation calculations were achieved by combining this with the FVM method. The temperature field of a complex three-dimensional structure can be predicted quickly and accurately. To validate the performance of the proposed algorithm, the multilayer thermally unstable structure and pulsating flame boundary conditions were selected and tested. Working according to the theory of accumulated energy, four mode sets were applied to conduct the investigation. The selection of POD modes had a greater impact on the extrapolation results; a mode set composed of more POD modes can improve the accuracy of the extrapolation results, although it will increase the calculation time accordingly. However, the prediction of explosion time is not positively correlated with the number of modes. The results obtained by the proposed method show good agreement with the experimental data and the FVM results. The relative error will increase as the extrapolation time increases in the small number mode set. At the same time, regardless of the number of POD modes, the disadvantage that the POD only captures the main trend is obvious, and further optimization of the algorithm is needed. The POD-FVM reduced-order extrapolation method reduces the degrees of freedom of the system from a magnitude of 10\({}^{5}\) to 10\({}^{1}\), which greatly improves the computational speed by more than 1400 times. Above all, fast thermal field analysis under non-periodic boundary conditions is achieved, and this may aid in solving critical challenges in the rapid reconstruction and prediction of the temperature fields of sophisticated components, thereby enabling monitoring, diagnosis, and protection.  
Conceptualization, F.W. and X.L.; data curation, F.W. and Y.Z.; formal analysis, B.Z.; investigation, F.W., Y.H. and B.Z.; methodology, F.W., Y.H. and B.Z.; resources, X.L.; software, F.W.; validation, Y.H. and Y.Z.; writing--original draft, F.W.; writing--review and editing, Y.Z. and X.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the China Academy of Engineering Physics and the grant number [TCGH0421].  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflict of interest.