esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Conclusions  
In this paper, an analytical RS-GBSM based S2A channel model for UD of scatterers over an open area is proposed. Based on the presented geometry, the CIRs of the LOS path, the specular reflection path, and the scattering path are formulated. The corresponding time-frequency TFs, ACFs and PSDs are derived and simulated. Simulation scenarios are designed as three states, e.g., the rising state, the cruising state, and the descending state. In each state, several moments are selected to illustrate the time variant features of the channel. Through the simulation results, the non-stationary features of the channel in rising and descending states are evidently observed, while in cruising state, the channel is quasi-stationary. Furthermore, based on an reasonable simplification that the scattering area can be approximated as an ellipse, the closed form expression of path delay distribution is derived, simulation results coincide with the theoretical results perfectly. The distributions of path attenuation, and Doppler shift of the scattering path are also simulated and fitted since no closed form expressions of their CDFs can be derived. Based on the theoretical and simulation results of the distributions of channel coefficients, the non-stationary features in the rising and descending states are observed and analyzed, as well as the quasi-stationary feature in the cruising state. These observations are in accord with the analysis with the channel formulations. Future work will focus on the derivation and analysis based on different distributions of scatterers, for example, von-Mises Fisher (VMF) distribution as adopted in [36]. Since the geometrical structures of channel modeling must base on the realistic environment, further investigation on concerned achievements in geography and physics would be performed. Analytical non-stationary channel models of extended scenarios, e.g., A2A scenario, will be developed as well.  
Conceptualization, Z.W. and J.G.; methodology, Z.W. and H.Y.; software, Q.T. and S.C.; validation, Z.W., Q.T., and S.C.; formal analysis, Z.W., S.C. and H.Y.; investigation, Z.W., Q.T. and S.C.; resources, L.S., and H.Y.; data curation, Z.W., Q.T. and S.C.; writing-original draft preparation, Z.W., Q.T.; writing-review and editing, Z.W., Q.T. and H.Y.; visualization, Z.W. and Q.T.; supervision, L.S. and H.Y.; project administration, J.G. and Z.W. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Conflicts of InterestWe declare that we have no conflict of interest.
## 4 Experimental Results and Analysis
### Datasets  
Nine corresponding benchmark datasets are used in our experiments, including five face image datasets (YALE, [[http://www.cvc.yale.edu/projects/yalefaces/yalefaces.html](http://www.cvc.yale.edu/projects/yalefaces/yalefaces.html)]([http://www.cvc.yale.edu/projects/yalefaces/yalefaces.html](http://www.cvc.yale.edu/projects/yalefaces/yalefaces.html)), accessed on 16 May 2012; JAFFE, [[http://www.kasrl.org/jaffe.html](http://www.kasrl.org/jaffe.html)]([http://www.kasrl.org/jaffe.html](http://www.kasrl.org/jaffe.html)), accessed on 28 May 2020; ORL, [[https://www.cl.cam.ac.uk/research/dtg/attarchive/facedatabase.html](https://www.cl.cam.ac.uk/research/dtg/attarchive/facedatabase.html)]([https://www.cl.cam.ac.uk/research/dtg/attarchive/facedatabase.html](https://www.cl.cam.ac.uk/research/dtg/attarchive/facedatabase.html)), accessed on 28 May 2020; AR, [[http://www2.ece.ohio-state.edu/](http://www2.ece.ohio-state.edu/)]([http://www2.ece.ohio-state.edu/](http://www2.ece.ohio-state.edu/))$.sim$aleix/ARdatabase.html, accessed on 28 May 2020 and COIL20, [[http://www.cs.columbia.edu/CAVE/software/softlib/coil-20.php](http://www.cs.columbia.edu/CAVE/software/softlib/coil-20.php)]([http://www.cs.columbia.edu/CAVE/software/softlib/coil-20.php](http://www.cs.columbia.edu/CAVE/software/softlib/coil-20.php)), accessed on 28 May 2020), a binary alpha digit's dataset BA, and three text datasets (Tr11, Tr41, and Tr45).  
The YALE dataset consists of 165 grayscale face images of 15 people. For each individual, there are 11 images, which were obtained under varying illuminations, and all the images are resized to the size of 32 \(\times\) 32. The JAFFE dataset consists of 213 face images of seven facial expressions, each of which is resized to 26 \(\times\) 26 pixels. The ORL dataset is composed of 400 face images from 40 people. For each person, there are 10 images, which were obtained under varying lighting and varying facial expressions, and all the images are resized to 26 \(\times\) 26. The AR database is composed of more than 4000 frontal images from 126 individuals, 120 of which are used in our experiment [37]. The 120 individuals consist of 65 men and 55 women. The COIL20 dataset consists of 72 images of 20 individuals, and all the images are resized to 32 \(\times\) 32 pixels. The BA dataset contains 1404 handwritten digits images, including digits \"0\" to \"9\" and uppercase letters \"A\" to \"Z\". The sizes of all these images are 20 \(\times\)16 pixels. The text datasets include TR11, TR41, and TR45. The detailed information of these datasets is presented in Table 1.
# SAM-PAY: A Location-Based Authentication Method for Mobile Environments +
## 7 Discussion and Future Work  
The proposed SAM-PAY method was designed with usability in mind. It allows users to use simple one-time codes generated by the SP based on the user's location (as calculated via the GNSS system and certified by an LE ground element run by an MNO) and keys shared between the SP and the user in the registration phase. The work can be further extended in several directions: for example, in highly sensitive/critical scenarios, to mitigate GNSS spoofing attacks, the UT could be replaced with an UT integrated with a receiver supporting OSNMA [72], such as the ones manufactured by Septentrio and prototyped in the ROOT project [20]. Architecture and workflow could be further enhanced with anonymous credentials (as in [40]) to support service unlinkability and location privacy. Service unlinkability means that the mobile network operator should not be able to link  
Figure 6: Test-bed for the self-service gas-station scenario exploiting the SAM-PAY authentication method.  
location-certification requests for a user to a particular Service Provider. Location privacy means that the SP, on the other hand, should not be able to learn location information for users identified with real identities, but pseudonyms should be used instead. Alternatively, the SP could merely learn whether the user of the UT is within a (larger) area where they are expected to be, thus enlarging the Toleration Distance to a wider reference area. Unfortunately, in this case, we increase the attack surface because the location information (used in the SAM-PAY method) is not accurate. Thus, potential attacks could occur if the attacker is placed within the reference area. Future work could address the extension of the SAM-PAY method to integrate behavioral factors and methods for countering device theft or cloning (i.e., assurance that the legitimate owner controls the device at transaction time). Last but not least, the work can be further extended to better protect sensitive symmetric keys (\(KS_{e}\) and \(KS_{a}\)) both on the user side and the SP side. In particular, a Trusted Execution Environment (TEE) could be exploited for this purpose since many phones on the market already include a TEE or parts thereof, e.g., ARM TrustZone or a Secure Enclave, in order to execute the trusted code. Additional tests are needed for this part because executing such a trusted code incurs a management burden and time requirements similar to those involved in running applications on Secure Elements [73]. Finally, the work could be extended to integrate additional authentication elements into the SAM-PAY method, like, for example, behavioral authentication, providing assurances that the mobile device is being used by its owner. Interesting proposals in this sense may be found in some research papers, e.g., [41; 74].
## 3 Results
### Upscaled GPP  
Figure 9a-c show that the regional RF-modeled cumulative seasonal GPP (GPP\({}_{\text{RF}}\)) averaged from 23 weather stations and 3 EC stations during the period of 2014-2018 was much higher for the rice growth seasons (924 g C m\({}^{-2}\)) than that for the wheat growth seasons (532 g C m\({}^{-2}\)). This relationship (cumulative seasonal GPP in the rice growth season > cumulative seasonal GPP in the wheat growth season) was also be confirmed by the GPP\({}_{\text{MOD}}\) in Figure 9d-f. For our study sites, the annual mean for GPP\({}_{\text{MOD}}\) and GPP\({}_{\text{RF}}\) averaged from 23 weather stations and 3 EC stations were 966 g C m\({}^{-2}\) and 1548 g C m\({}^{-2}\), respectively. Figure 9g-i show the difference between the two GPP products across all sites (relative error at each site as computed by \((\text{GPP}_{\text{MOD}}\)-\(\text{GPP}_{\text{RF}})\)\(\times\) 100/\(\text{GPP}_{\text{RF}}\)) during the period of 2014-2018. Relative errors exhibited negative values across all sites, with  
Figure 7: Scatter density plots for the random forest model in predicting gross primary productivity in the (**a**) 10-fold cross-validation training set, (**b**) 10-fold cross-validation testing set, (**c**) validation by the rest of the samples at the Shouxian and Dongtai sites, and (**d**) validation by all samples at the Dafeng site.  
\(-18\)--\(-46\)% for rice growing seasons, \(-1\)--\(-50\)% for wheat growing seasons and \(-5\)--\(-47\)% for the whole year, respectively. In general, relative errors during the wheat growing seasons were relatively larger than those during the rice growing seasons/the whole year at most sites (Figure 9g-i).  
To examine the spatial consistency of the GPPRF dynamics among the upscaled sites, Figure 10 shows the seasonal variations in GPPRF among 23 weather stations and 3 EC stations during the period of 2014-2018 over the rice-wheat-rotation cropland in the North Yangtze River Delta region. The daily mean GPPRF averaged from 23 weather stations and 3 EC stations during the period of 2014-2018 for wheat was lower than 2 g C m\({}^{-2}\) d\({}^{-1}\) during the winter extensive bare soil period (December-February). It started to increase in the active tillering stage (March) and reached a maximum of about 8-10 g C m\({}^{-2}\) d\({}^{-1}\) during the heading stage (late April), and next decreased to around 4 g C m\({}^{-2}\) d\({}^{-1}\) at harvest. The largest daily GPPRF for rice paddies occurred in late July, with a peak value of about 11 g C m\({}^{-2}\) d\({}^{-1}\), suggesting that the rice biological activities (e.g., photosynthetic rates) were quite strong at this stage. After that, daily GPPRF decreased to approximately 1 g C m\({}^{-2}\) d\({}^{-1}\) at rice harvest (Figure 10). Generally, good consistency was found in the seasonal variation among all upscaled sites, exhibiting similarly temporal characteristics of the real GPP over the rice-wheat-rotation system (Figure 4).
## 5 Outlook: The Benefits of Additive Manufacturing  
Three-dimensional printing or additive manufacturing of metallic components is aimed at improving the efficiency of the production of complex components that are durable and expensive, which could not necessarily be accomplished with traditional forging and casting machinery. This advent presents an opportunity for industries and small, micro, and medium enterprises (SMMEs) to realise a full value chain in metal alloy production and processing in the most cost-effective sense. Until the need for lightweight frames and component structures in aeroplanes, the industry of metal 3D printing was performing adequately. With the understanding that the intermetallic group of alloys, called titanium aluminides, presents the potential for durable lighter structures, 3D printing of aerospace structures was centred on Grade 5 titanium alloy (Ti6 Al4V); hence, there are so many scientific articles on the topic of additive manufacturing or 3D printing of Ti6 Al4V.  
According to the MarketWatch news report of 5 November 2019, the titanium aluminide market was valued at 140M USD in 2018 and is expected to reach a market share of 640M USD, a growth rate of about 21% in the period of 2019-2025. To share in this wealth, many big corporations and industries have embarked on understanding how the route to alloy development, processing, and part printing can be achieved. The success of Boeing in manufacturing Ti-Al components for Boeing's Dreamliner 747-8 aircraft and Boeing's next-generation long-haul plane (the 777X) is the greatest achievement, however exorbitant in set-up and post-processing.  
To advance further in manufacturing, aircraft companies would be in search of functionally graded structures that can serve in different environments and adapt without failing, and this need cannot immediately be met with powder bed technologies. These structures can only be achieved with direct energy deposition technologies, given their freedom of operation and powder deposition. Many FGM studies have been commissioned on the characteristic change (improvement) of one powder over the other. However, the use of similar approaches in powder alloy development in flight during 3D printing was not yet commissioned until around 2015-2018. Until recently, studies using the alloy approach in Ti-Al research have achieved crack-free builds. Of greatest importance are the remarkable results achieved by laser metal in situ alloying during 3D printing. There are those who have predicted a cost savings of up to 40% in material cost reduction when 3D printing Ti-Al from its elemental powders. Therefore, this study contributes to the industry by providing a process for making Ti-Al-Nb alloys that could be machined, leading to cost savings.  
With respect to saving costs during manufacturing, in a handbook of _Non-Ferrous Metal Powders_ (second edition), 2019, three chapters were of significance to be reviewed and captured as a summary in this work. The authors put into context the benefits of the self-propagating process (or SHS), with a particular focus on Ti-Al.
## 4 Results
### Vulnerability Zoning Map  
The proposed matrix-based approach provided a vulnerability zoning map in January 2015 by combining, for each pixel, information on ground instability kinematics and damage level. It should be highlighted that such analysis is feasible only for pixels inside which both data were available. \"P.R. 264\" vulnerability map defines a \"priority action\" zoning map, identifying sections along linear infrastructure characterized by different levels of damage susceptibility. As shown in Figure 9, out of 690 pixels examined, 392 pixels showed a low vulnerability level, 222 a moderate level, and 75 a high level. No pixel is characterized by a very high vulnerability condition.  
Figure 8: Damage map (**a**) and examples (**b**) of failures occurred along “P.R. 264” surveyed in the period November 2014–January 2015.  
A good correspondence among landslides intensity, damage occurred, and vulnerability distribution, as indicator of a preliminary cause-effect relationship, has been obtained. In the considered test area, slow moving landslides interacting with \"P.R. 264\", characterized by low displacement rate (in the order of some mm/year), generally induced low and medium vulnerability levels. Occurred movements commonly caused light deformations and limited small cracks on road surface. It can be noticed that only annual displacement rates higher than 20 mm/year caused a moderate and high vulnerability level. In the latter case the functionality of the infrastructure is partially were compromised and detailed geological and geotechnical analyses are required to urgently plan stabilization measures (Figure 9b).
## 5 Experimental Results and Discussion
Likewise, the obtained efficiency of the proposed antenna array increases significantly in the desired frequency bands by 35.7% at 3.5 GHz and 60% at 5.5 GHz as shown in Figure 15. The gain, bandwidth, and the overall size of the multiband antenna are summarized in Table 3 for each operational band. Figure 14: A measured and simulated gain of proposed CPW antenna with and without MTM. Figure 13: Simulated and measured reflection coefficient (S11) with MTM. Figure 15: The proposed CPW antenna efficiency with and without MTM. To verify the performance of the proposed antenna loaded with metamaterial, Horn antenna was considered as transmitter source antenna, whereas the fabricated prototype was used as a receiver prior to being connected to an Agilent E8051C network analyzer (ENA) via a coaxial cable to measure the radiation patterns through a far-field measurement system which is located in an anechoic chamber. Both antennas terminals are placed 1.25 m apart. The E-field radiation patterns (XZ-plane and YZ-plane) shown in Figure 16 indicate almost an omnidirectional behavior at each resonant frequency except at 5.8 GHz, which indicates bidirectionality. Furthermore, the simulated and measured radiation patterns are in agreement.
###### Abstract  
Interferences can severely degrade the performance of Global Navigation Satellite System (GNSS) receivers. As the first step of GNSS any anti-interference measures, interference monitoring for GNSS is extremely essential and necessary. Since interference monitoring can be considered as a classification problem, a real-time interference monitoring technique based on Twin Support Vector Machine (TWSVM) is proposed in this paper. A TWSVM model is established, and TWSVM is solved by the Least Squares Twin Support Vector Machine (LSTWSVM) algorithm. The interference monitoring indicators are analyzed to extract features from the interfered GNSS signals. The experimental results show that the chosen observations can be used as the interference monitoring indicators. The interference monitoring performance of the proposed method is verified by using GPS L1 C/A code signal and being compared with that of standard SVM. The experimental results indicate that the TWSVM-based interference monitoring is much faster than the conventional SVM. Furthermore, the training time of TWSVM is on millisecond (ms) level and the monitoring time is on microsecond (us) level, which make the proposed approach usable in practical interference monitoring applications.  
global navigation satellite system; interference monitoring; twin support vector machine +
Footnote †: journal: Sensors
## 3 Results and Discussion
### Plasmid Release Kinetics
Figure 7 shows the experimental data of the release of pDNA(sc) at various times of bead milling, using a mill frequency of 30 Hz. The continuous line represents the best fit of the model given in Equation (5) in each figure, with R\({}^{2}\)-values of 0.95, 0.84, 0.99, and 0.90 for Experiments 2, 4, 6, and 8, respectively. Faster kinetics of the release of pDNA(sc) can be achieved using low cell concentrations because the effectiveness of collisions between beads and the cells is not limited by the viscosity of the cell solution. The maximum pDNA(sc) obtained for Experiments 2 and 4 was an \(R_{\text{msc2}}\)-value of 6.53 mg pDNA(sc)/g dcw (Figure 7A), whereas for Experiments 6 and 8 the maximum was an \(R_{\text{msc3}}\)-value of 3.83 mg pDNA(sc)/g dcw (Figure 7B). The corresponding k-values are shown in the legend of Figure 7. At a high mill frequency, the release kinetics becomes faster causing a faster increase of the viscosity of the solution [38] and affecting maximum concentration of pDNA(sc) obtained, due to greater pDNA denaturalization. This effect is more pronounced when larger beads are used (Figure 7B). The \(R_{\text{mt}}\)-value of 14.16 mg/g dcw suggests that all the plasmid content may be released if proper conditions are used [39]. However, the \(R_{\text{msc1}}\)-value of 8.98 mg/g dcw obtained at a low mill frequency represents the maximum concentration attainable and a lower pDNA(sc) purity. Since a higher purity and lower recuperation is obtained in shorter time periods, these results imply a compromise between pDNA(sc)  
Figure 6: Kinetics of pDNA(sc) release with a mill frequency of 15 Hz. (o) Experiment 1: \(k\) = 1.24 min\({}^{-1}\); (*) Experiment 3: \(k\) = 0.76 min\({}^{-1}\); (\(\Delta\)) Experiment 5: \(k\) = 0.14 min\({}^{-1}\); (\(\square\)) Experiment 7: \(k\) = 0.22 min\({}^{-1}\); (\(\blacktriangleright\)) model fit. Data represent the means of two replicates and error bars represent the standard deviation. Figure 7: Kinetics of pDNA(sc) release with a mill frequency of 30 Hz. (**A**) (o) Experiment 2: \(k\) = 5.40 min\({}^{-1}\); (*) Experiment 4: \(k\) = 0.82 min\({}^{-1}\). (**B**) (\(\Delta\)) Experiment 6: \(k\) = 1.62 min\({}^{-1}\); (\(\square\)) Experiment 8: \(k\) = 1.04 min\({}^{-1}\); (\(\blacktriangleright\)) model fit. Data represent the means of two replicates and error bars represent the standard deviation. purity and recuperation in process development. At a high mill frequency with an \(R_{\rm msc2}\)-value of 6.53 mg/g dcw and an \(R_{\rm msc3}\)-value of 3.83 mg/g dcw, this behavior is more evident.
# Long-Term EEG Component Analysis Method Based on Lasso Regression
## 3 Experiments and Results  
### Cognitive Experiment and Data Description  
To verify the method proposed in this article, a long-term auditory emotion cognition experiment was firstly designed. Music is composed of short-term notes. Therefore, 93 environment sounds were selected and played randomly, which were arranged together, and formed as a long-term sound signal. The emotional response and evaluation of sounds are essential components of human cognition. For example, people will be irritable when they hear noise, be pleased when they hear the sounds of birds, and be frightened when they hear thunder.  
The experimental samples were mainly considered from two aspects: one was that short-term analysis techniques could be applied to compare with current work; and the other was to analyze the long-term brain components through the method proposed in this article. Finally, a total of 93 samples were selected with a length of 1-2 s, from 259 sounds among three emotional sound libraries, IADS2, Montreal, and MEB, based on the emotional tags.  
The experimental design adopted a task-independent practical method. The entire experiment was divided into two parts: listening to the sound while collecting EEG signals; and listening to the sound and evaluating the Valence-Arousal (VA) dimensional emotions. The EEG acquisition experiment adopted the 1-back experimental paradigm, in which 20% may repeat the previous sound. The experimental process is shown in Figure 5. In addition, 51 volunteers who did not participate in the experiment evaluated the emotions of each segment online. The SAM assessment was used, which included the scores 1-9 from the three dimensions of valence, arousal, and domination.  
A total of 10 volunteers (undergraduates aged between 19 and 25 years old) participated in the experiment. The experiment included 12 blocks, and each block lasted about 5 min. There was a 1-min rest between the blocks. The whole experiment was about 60 min. The EEG signal was recorded through a 128-channel EEG system (BioSemi Active Two). The sampling frequency was 1000 Hz, and the electrode arrangement was placed according to the international 10-20 system standard (shown in Figure 6). The left mastoid was used as a reference to avoid asymmetry of the left and right hemispheres.
## 4 Coverage Path Planning
### Coverage Path Planning for Special Terrain  
Special terrain areas have large ground undulations. If the same coverage method as that used in simple terrain areas is employed, the elevation difference in the coverage paths may become significant. Therefore, it is necessary to utilize a coverage method specific to special terrain areas. Based on previous analysis of the energy consumption of robots moving on uneven ground, this paper proposes a special terrain area coverage method that is optimized for energy consumption.