esa-sceva/satcom-chunk-collection huggingface dataset:
## 4 Experimental Results
### Objective Evaluation
#### Information Entropy
Compared with wavelet transform and the adaptive gamma algorithm, this algorithm is better in terms of image richness; however, due to the large amount of image information that must be processed, the image processing results in terms of peak signal-to-noise ratio, mean squared error and structural similarity are slightly inferior to those of simple wavelet transform. The innovative adaptive \(\gamma\) transform described in this study also has good indicators. In terms of processing time, the algorithm in this study also has a certain advantage. In terms of comprehensive image processing results and objective indicators, this high-dynamic infrared image processing enhancement effect of the algorithm presented in this study is obvious. It also has a wide application scope and good reference value and is worth further research and discussion.
# High-Accuracy Clock Offsets Estimation Strategy of BDS-3 Using Using Multi-Source Observations
## 1 Introduction
Each superimposition of the two-way clock offset is accompanied with accuracy loss and will decrease the accuracy of satellite clock offset parameters. As a result, some research finds that the clock offset parameters of BDS-3 are not accurate enough [9; 10]. With the continuous improvements and developments in terms of performance, availability, modernization, application, and hybridizing for current GNSS [20; 21; 22], BDS must face up to the problem in its clock measurements and take it as the guide to study the new approach to improve its signal-in space accuracy. For the above reason, we analyze the problems in the BDS-3 two-way superimposition strategy in the first part. Then, guided by solving the problems, we proposed a new strategy. The new strategy considers and combines BDS-3 constellation composition and multi-source measurements accuracy to real-time estimate BDS-3 satellite clock offsets with  
Figure 1: The construction of BDS time synchronization and the basic two-way measurements of BDS-3. Wherein, the red, blue, yellow curves are L-band satellite-station two-way measurements, Ka-band inter-satellite measurements, C-band inter-station two-way measurements, respectively. higher accuracy. We analyze the accuracy and improvements of the new strategy in the last part.
# Anomalous Origin of the Right Vertebral Artery
## 4 Discussion  
In almost all cases, the anomalous origin of the VA is an incidental finding. In rare cases, patients are complicated by dizziness and have a correlation with an anomalous origin of the VA [16]. Although conclusive evidence has not been established between the anomalous origin of the RVA and cerebrovascular disease, some authors have suggested that alterations in the large vessels can change the cerebral hemodynamics to possibly cause cerebral vascular disease, including aortic dissection, aneurysm, and arteriovenous fistula [17]. In recent years, the advancements in imaging technology have been remarkable. In the near future, it may be shown that hemodynamic changes brought about by vascular anomalies are the cause of cerebrovascular disease. Especially, as some authors suggest, the relation between the cerebrovascular events and the radiomics [18; 19; 20]; however, there have not been any reported relations about the anomalous origin of the right VA and radiomics. Therefore, radiomics are a possible application to clarify the potential relationships in the future. The clinical importance of recognizing the anomalous origins of the RVA are to prevent complications in cervico-thoracic surgery and endovascular treatments as well as to avoid misdiagnosing the anomaly as other vascular pathologies. For example, the duplicated origins of the VA are often misdiagnosed as dissections. The VR images are very useful to evaluate the branching pattern of great vessels. Therefore, surgeons are also required to evaluate the VR image before surgery.  
Figure 8: The dual origin of the RVA. (**a**) Right anterior oblique view of the magnetic resonance angiography (MRA) shows the dual origin of the RVA. The abnormal VA originates from the RCCA (white arrowhead). (**b**) Axial views of the source image of the MRA show the abnormal VA (white arrowhead) originating from the common carotid artery and the normal vessels from the RSCA.  
Figure 7: The dual origin of the RVA. Left anterior oblique view on VR-CT angiography shows the dual origin of the RVA. The abnormal VA originates from the RSCA (black arrowhead). The Ziostation 2 (Ziosoft Inc., Tokyo, Japan) was used to obtain the VR image.  
In conclusion, typical imaging features of several anomalous origin types of the RVA were demonstrated with their embryological development. This knowledge is very important for safe and successful procedures in vascular surgery and endovascular treatment.  
For research articles with several authors, conceptualization and editing are credited to K.T. and H.K. Acquisition was attributed to H.B. Supervision, review and editing were accomplished by H.K. and Y.A. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.
## 3 Jamming Attack Models
### Random Jamming  
We are using a random jamming model where packets are produced following a uniform distribution and \(\rho\) is the number of packets per second generated by the jammer node. As expected, \(\rho\) can be adjusted to increase or reduce the level of the jammer aggressiveness. A low value of \(\rho\) indicates a reduced interference activity, and as consequence, the DoS will not be constantly carried out. However, from a detection jamming mechanism point of view, it would be quite difficult to detect this attack, since its effects can be misinterpreted as normal interference due to the wireless environment (other wireless networks and devices sharing the same bandwidth). By way of comparison, a high value of \(\rho\) will produce a more severe DoS effect, and it could be evident that an abnormal interference activity is being performed; this scenario can be considered as a worst case for the WSN in terms of performance degradation.  
We note in passing how our random jamming model compares to that of [4]. If we set \(\rho\) to a very large value, we end up with a model that [PERSON] _et al._ call deceptive, which constantly injects regular packets into the channel (without any gap between subsequent packet transmissions). By contrast, if we set \(\rho\) to an intermediate value, then we end up with a model very similar to what they call random, the only difference being that, instead of sending a burst of two or more packets, we send only one. Our packet inter-generation time corresponds to the pause step of [PERSON] _et al._, where the node falls asleep.
# Stacked Ensembles Powering Smart Farming for Imbalanced Sugarcane Disease Detection
## 2 Methodology  
### Dataset  
The dataset that was used to train the model was the open-source sugarcane leaf image dataset [41]. It consists of 7134 high-resolution images of sugarcane leaves, stored in JPG format, with dimensions of \(768\times 1024\) pixels. The data are split into 11 categories, which include healthy leaves, dried leaves, and 9 diseases (banded chlorosis, brown spot, brown rust, grassy shoot, pokkah boeng, set rot, viral disease, yellow leaf, and smut).
## Materials and Methods
### \(\beta\)-Glucuronidase (GUS) Staining and Activity Detection  
The \(\beta\)-glucuronidase (GUS) gene is a commonly used reporter gene, which could reflect promoter expression levels. GUS histochemical staining was performed on tobacco leaves using the GUS Staining Kit (Solarbio, Beijing, China). First, tobacco leaves were punched and soaked in GUS staining solution. The vacuum pump was used for 30 min under a 0.085 kPa condition, then stained overnight at 37 \({}^{\circ}\)C. Finally, a 75% ethanol solution was used to decolorize. GUS expression was observed and photographed under a microscope (Leica M205 FA, Wetzlar, Germany). Moreover, the quantification of GUS activity was determined using the fluorometric 4-methylumbelliferyl-b-D-glucuronide (MUG) method. One unit of GUS activity was defined as 1 nM of 4-methylumbelliferon (4-MU) generated per milligram of soluble protein per minute. Three leaves were infiltrated for each construct in each independent experiment and then combined to detect GUS activity.  
Construction of vvmiR156b/c/d and VvSPL9 Overexpression Vectors and Instantaneous Injection of Tomato  
Based on the precursor sequences of VvmiR156b/c/d downloaded from the miRBase database ([[http://www.mirbase.org/](http://www.mirbase.org/)]([http://www.mirbase.org/](http://www.mirbase.org/)), accessed on 14 April 2021), specific primers containing NcoIl and Spel restriction sites were designed for PCR amplification (Table S1). PCR amplification was conducted as follows: 5 min at 94 \({}^{\circ}\)C, 30 s at 94 \({}^{\circ}\)C, 30 s at 56 \({}^{\circ}\)C, 1 min at 72 \({}^{\circ}\)C, 35 cycles, and extension at 72 \({}^{\circ}\)C for 10 min. First, the PCR fragments were purified and ligated into the vector pMD19-T and transformed into DH5\(\alpha\) competent cells. Second, the target fragment and pCAMBIA-1302 vector were digested with NcoIl and Spel and ligated with the T4 DNA ligase, then transformed into DH5\(\alpha\) competent cells. Finally, the combined plasmid vectors were transferred into _Agrobacterium_ EHA105, and positive clones were identified through PCR.  
In transgenic research, grape transgenic technology has not yet been perfected and matured, while tomato is a model plant and has formed a series of mature technical systems. Therefore, instant injection of tomato can be used to quickly verify the function of genes. Each _Agrobacterium_ strain of VvmiR156b/c/d and _VvSPL9_ was cultured in LB liquid medium supplied with rifampicin (100 ug/mL) and kanamycin (100 ug/mL). After OD600 = 0.8, the bacteria were pelleted and resuspended in suspension buffer (10 mM MgCl\({}_{2}\), 10 mM MES, and 150 uM AS) and left to stand at room temperature for 3-4 h. Finally, a syringe was used to inject the _Agrobacterium_ liquid into the tomato before the color change [31]. Ten uniformly sized fruit were used in the infiltration experiment, and the experiment was repeated three times. The pCAMBIA1302 vector universal primer was used for PCR amplification to obtain striped positive plants.
## 2 Related Work
### Redundant Switches  
In the market, there are already some products capable of implementing redundant protocols, which are briefly analyzed in this section. The analyzed products are the Flexibilis Redundant Switch (FRS) by Flexibilis [10], the High-Availability Seamless Redundancy and Parallel Redundancy Protocol Switch (HPS) by SoC-e [11], the RED25 [12] by Hirschmann, and, finally, the PRP-1 IP Core and the High-Availability Seamless Redundancy (HSR) IP Core [13] developed by Zurich University of Applied Sciences. All of them, except the PRP-1 IP Core, can implement both redundant protocols (PRP and HSR). Most products can work at speeds of 10/100/1000 Mps, are capable of filtering by EtherType and/or MAC address, have a CPU interface for communication and control, and even have the Precision Time Protocol (PTP) implemented over the redundant protocol for better synchronization. RED25, by Hirschmann, stands out with its unique features as it is being prepared for application in harsh industrial environments, being very resilient. Table 1 summarizes the characteristics of the mentioned products.
# A Review of Machine Learning Applications in Land Surface Modeling
## 5 Techniques of Machine Learning
### Random Forests (RF)  
RF [73, 74, 75] are supervised non-parametric ML algorithms, which are ensemble-learning methods using decision trees as base learners. This is a fast, flexible and robust approach to high-dimensional data mining that relies on aggregating the results of an ensemble of simple estimators. Decision trees are intuitive ways to classify objects or label objects by binary splitting. Variable space is divided into a set of boundaries, and a model is fitted to each set (which can be a constant in the simplest case). However, overfitting tendency of such trees can be reduced by an ensemble of randomized trees and that motivates the usage of 'bagging' or RF technique (equipped with some additional randomization techniques reducing the correlation between the trees). In LSM applications, RF is mostly used within the context of regression, i.e.; for continuous prediction rather than categorical. Users generally provide the number of trees in the forest and a criterion to measure the quality of a split, such as mean square error. Hyperparameters are also provided to improve the model performance and control overfitting. In general, statistical learning has two main purposes: (1) prediction and (2) inference. In the case of RF, interpreting the model can be done either by looking at a single tree in the forest or by examining the relative importance of independent variables. Overall, RF method is found to be (1) consistent (2) reducing the bias and variance simultaneously, (3) achieving convergence at high rate and (4) adaptive to sparsity, which makes it applicable even with noisy predictor variables [74].  
RF is often superior to other traditional ML methods like SVM or CART because it (1) considers an ensemble of decision trees and does not need multiple models like others (e.g.; SVM) to provide a probabilistic prediction, (2) provides more generalized solution,(3) needs no feature scaling (4) can handle high dimensional spaces as well as large number of training examples.
###### Abstract  
Vehicle-to-Infrastructure (V2I) communication is expected to bring tremendous benefits in terms of increased road safety, improved traffic efficiency and decreased environmental impact. In 2017, The 3 rd Generation Partnership Project (3 GPP) released 3 GPP Release 14, which introduced Cellular Vehicle-to-Everything communication (C-V2X), bringing Vehicle-to-Everything (V2X) communication capabilities to cellular networks, hence creating an alternative to Dedicated Short-Range Communications (DSRC) technology. Since then, every new 3 GPP Release including Release 15, a first full set of 5G standards, offered V2X capabilities. In this paper, we present a complex simulation study, which benchmarks the performance of LTE-based and 5G-based C-V2X technologies deployed for V2I communication in an urban setting. The study compares LTE and 5G deployed both in the Device-to-Device in mode 3 and in infrastructural mode. Target performance indicators used for comparison are average end-to-end (E2E) latency and Packet Delivery Ratio (PDR). The performance of those technologies is studied under varying communication conditions realized by a variation of vehicle traffic intensity, communication perimeter and message generation frequency. Furthermore, the effects of infrastructure deployment density on the performance of selected C-V2X communication technologies are explored by comparing the performance of the investigated technologies for three infrastructure density scenarios, i.e., involving two, four and eight base stations (BSs). The performance results are put into a context of the connectivity requirements of the most popular V2I communication services. The results indicate that both C-V2X technologies can support all the considered V2I services without any limitations in terms of the communication perimeter, traffic intensity and message generation frequency. When it comes to the infrastructure density deployment, the results show that increasing the density of the infrastructure deployment from two BSs to four BSs offers a remarkable performance improvement for all the considered V2I services as well as investigated technologies and their modes. Further infrastructure density increase (from four BSs to eight BSs) does not yield any practical benefits in the investigated urban scenario.  
cellular-V2X; 4G networks; 5G networks; vehicle-to-infrastructure communication; packet delivery ratio; end-to-end latency +
Footnote †: journal: Applied Sciences
# Optical Helicity and Chirality: Conservation and Sources
## 2 Review and Motivation
### Helicity and Duality Symmetry  
The free-space Maxwell equations treat electric and magnetic fields on equal footing. To say this more precisely: the form of the free space Maxwell equations is invariant under the duality transformation [41]:  
\[\mathbf{E} \longrightarrow \mathbf{E}\cos\theta+c\mathbf{B}\sin\theta,\] \[c\mathbf{B} \longrightarrow c\mathbf{B}\cos\theta-\mathbf{E}\sin\theta, \tag{7}\]for any real (pseudoscalar) angle \(\theta\). This property of the free electromagnetic field has been variously referred to as the Heaviside-Larmor symmetry, duplex symmetry [14], dual-symmetry [18] or \"electric-magnetic democracy\" [42]. The helicity of the electromagnetic field is fundamentally connected with the dual-symmetry of the free-space Maxwell equations: the duality transformation can be obtained by taking the helicity as the generator of an infinitesimal transformation of the fields [14]. To put the matter the other way around, the conservation of helicity in a vacuum can be derived from the dual-symmetry of the free-space Maxwell equations using [PERSON]'s theorem [12].  
Here, we will examine the approach taken in [15; 17], where the quantum-mechanical optical helicity \(\hat{h}\) is used to form the transformation operator:  
\[\hat{U}(\theta)=\exp\left(-\frac{i}{\hbar}\theta\hat{h}\right), \tag{8}\]  
which can be applied to the vector fields \(\mathbf{\hat{E}}\) and \(\mathbf{\hat{B}}\) in (5) to produce:  
\[\hat{U}^{\dagger}(\theta)\,\mathbf{\hat{E}}\,\hat{U}(\theta)= \mathbf{\hat{E}}\cos\theta+\epsilon\mathbf{\hat{B}}\sin\theta,\] \[\hat{U}^{\dagger}(\theta)\,\epsilon\mathbf{\hat{B}}\,\hat{U}( \theta)=\epsilon\mathbf{\hat{B}}\cos\theta-\mathbf{\hat{E}}\sin\theta. \tag{9}\]  
This is in complete analogy with (7), where now, the helicity operator \(\hat{h}\) is explicitly shown to generate this transformation. Results for the potentials \(\mathbf{\hat{A}}\) and \(\mathbf{\hat{C}}\) in (5) follow similarly:  
\[\hat{U}^{\dagger}(\theta)\,\mathbf{\hat{A}}\,\hat{U}(\theta) =\mathbf{\hat{A}}\cos\theta+\sqrt{\frac{\mu}{\epsilon}}\mathbf{ \hat{C}}\sin\theta,\] \[\hat{U}^{\dagger}(\theta)\,\mathbf{\hat{C}}\,\hat{U}(\theta) =\mathbf{\hat{C}}\cos\theta-\sqrt{\frac{\epsilon}{\mu}}\mathbf{ \hat{A}}\sin\theta. \tag{10}\]
## 1 Introduction
The proposed NC-Euler-WESPRIT DPD algorithm takes full advantage of elliptic covariance information of NC signals to expand the virtual array aperture. Compared with original two-step localization technique and SDF algorithm, NC-Euler-WESPRIT DPD increases the available degrees of freedom (DOF). 2. Euler transformation is applied to decrease the complexity by converting complex number calculation into real number operation and ESPRIT is applied to avoid the high-dimensional spectral function search problem of each observation station. Then we combine the information of all observation stations to construct a spectral function without complex multiplication to further reduce the computational complexity. 3. In practice, there will be loss when the signal propagates in the air and SNRs of received signals at each observation station are often different. Therefore, a specific weight is set to compensate for the projection error and get better positioning performance. 4. Complexity analysis, Cramer Rao lower bound (CRLB) and simulation consequence are given to check the effectiveness and superiority of the NC-Euler-WESPRIT DPD algorithm. The following structure of the article is: A data model is introduced in Section 2. A NC-Euler-WESPRIT DPD algorithm is derived in Section 3. Performance analysis, simulation experiments and conclusions are put in Sections 4 and 5, respectively. It should be noted that vectors and matrices are lower-case bold and upper-case bold, respectively; \(\text{diag}\{\cdot\}\) represents diagonal matrix; \(||\cdot||\) represents the \(l_{2}\) norm; \(|\cdot|\) indicates absolute value; \((\cdot)^{\ast}\), \((\cdot)^{T}\), \((\cdot)^{H}\) denote conjugate, transposition and conjugate transpose, respectively; \(\text{Re}(\cdot)\) and \(\text{Im}(\cdot)\) denote real part and imaginary part, respectively; \(\mathbf{I}_{N}\) denotes \(N\) dimensional unit array; \(\otimes\) denotes Kronecker product; \(\partial(a)/\partial(b)\) stands for the derivative of a with respect to b; \((\cdot)^{+}\) and \((\cdot)^{-1}\) denote general Moore-Penrose inverse and the inverse of the matrix.
# A Perspective on Terahertz Next-Generation Wireless Communications
## 2 The Terahertz Channel
Hard-wired solutions are not the answer, particularly for mobile testing platforms, and Rb- and Cs-based clocks, though separable, are not precise enough for long-duration measurements at large distances. Therefore, the terahertz channel remains a challenge. While it is extremely well-understood in some regards, it is not well-understood in many dynamic or NLOS situations, and arguably is not even thoroughly measurable yet.
## 1 Introduction
As complex numbers have real and imaginary parts, a complex scale factor can be more arbitrary and unpredictable than a real scale factor, such that the calculation of complex numbers is more complicated than that of real numbers and, so, it is more difficult to obtain signal information from transmitted information. Moreover, CMPS establishes a connection between real and complex chaos, thus increasing the selection range of the chaos generator at the sending and receiving ends. Studying CMPS can increase the complexity of synchronization and, consequently, the diversity and security of communications. Recently, great improvements in integrated chips and wireless communications have promoted the development of wireless body area networks (WBANs). The security of data transmission in WBANs is more important and essential. Due to the low cost and high-security properties of chaotic signals, the implementation of chaos communication in WBANs is an effective and promising solution, which can improve communication security in WBANs. However, to the best of our knowledge, secure communication in WBANs based on the CMPS of complex chaos under noisy conditions has seldom been studied in the literature. The main contributions of this paper are as follows:  
(1) A basic introduction of the time delay complex Chen system, including the influence of parameter changes and time delay factors on the time delay system, is presented. (2) On the basis of complex modified projection synchronization (CMPS), a new controller and communication scheme are designed. (3) This communication scheme is applied to a wireless body area network (WBAN) for encrypting and decrypting body data that are collected by sensors. The rest of this article is organized as follows: In Section 2, the time delay characteristics of the complex Chen system are analyzed and its randomness, symmetry, and unpredictability are discussed. In Section 3, the innovation and advantages of the communication scheme for wireless body area networks are introduced. In Section 4, the CMPS controller design is described. In Section 5, the feasibility of the scheme is verified through MATLAB simulation. In Section 6, the security of the communication scheme for WBAN is analyzed. Section 7 summarizes this article.