esa-sceva/satcom-chunk-collection huggingface dataset:
## 7 Conclusions  
In this paper, we studied the coverage performance and EE of the two-tier MHCP-MHCP network. MISR gain for the MHCP-modelled network is given through simulation and data fitting. The approximate coverage expression of the MHCP-MHCP network was derived with the use of the ET-ASAPPP method. Furthermore, we derived and formulated the expression of the EE of the MHCP-MHCP network. Simulation results verified the correctness of the theoretical analysis and prove the effectiveness of the proposed ET-ASAPPP method. We found that the coverage and EE of the MHCP-MHCP network is much better than that of the PPP-PPP network, which means that MHCP is more suitable for modeling the actual BS deployment with mutual exclusion. Furthermore, when the BS densities and MBS transmit power are fixed, there exists an optimal PBS transmit power which can maximize the EE. Similarly, when the BS densities and PBS transmit power are fixed, there exists an optimal MBS transmit power which can maximize the EE. Therefore, we can improve the EE through the joint optimization of the MBS transmit power and PBS transmit power.  
Conceptualization, J.Y.; methodology, J.Y.; simulation, Z.P. and L.G.; formal analysis, J.Y. and Z.P.; writing--original draft preparation, J.Y. and Z.P.; writing--review and editing, L.G. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the National Natural Science Foundation of China No. 61701221, 61901211, the Natural Science Foundation of Jiangsu Province (China) No. BK20160781, Jiangsu Higher Education Institutions Natural Science Foundation No. 18 KJB510017, Nantong Science and Technology Project, No. JC2018127.  
The authors would like to thank [PERSON] of Nantong University for sharing her insight.  
The authors declare no conflict of interest.
# Evolution of V2X Communication and Integration of Blockchain for Security Enhancements
## 1 Introduction
When considering these gaps, the primary aim of this paper is to serve as a bridge for researchers who want to design new solutions shifting from conventional VANETs towards integrated V2X networks. Our systematic literature review on the integration of blockchain into 5G-based edge computing in V2X shows several significant findings that will open up multiple opportunities for newly evolving 5G V2X scenarios. We suggest the integration of blockchain with 5G-based edge computing in V2X that provides efficiency and scalability in vehicular networks. The efficiency can be obtained by having maximum coverage without extra overhead, while scalability can be obtained by maintaining ultra-low latency under various traffic conditions. The key contributions of this survey can be summarized, as follows. * We survey state-of-the-art V2X technology, including its definition; we highlight the V2X evolution, and provide detailed comparisons of cellular and non-cellular based V2X communication. * We present a review on the adoption of edge-based computing for V2X communications with particular emphasis on integrating promising technologies, such as MEC and Nonorthogonal multiple access (NOMA), and their applications in data offloading for 5G vehicular networks. * We investigate the potential of blockchain in V2X networks as a security mechanism. We examine the requirements of V2X and discuss on how the requirements are fulfilled by the blockchain. * We conducted an in-depth analysis of integrating blockchain with 5G and edge computing in V2X networks, and provide a detailed comparison of the integration of each technology. * We discuss the open issues and future research directions of integrated V2X networks. The organization of this paper is as follows. We begin with the introduction in Section 1. Section 2 presents a detailed overview of the V2X technology and discusses state-of-the-art V2X communications. In Section 3, we present the evolution of V2X technology that is based on cellular and non-cellular communications. In Section 4, we provide an in-depth discussion of edge computing for V2X communications, highlighting the integration of MEC and NOMA. Section 5 presents the potential issues and challenges faced by V2X networks. Section 6 provides the detail discussion on the integrating blockchain with 5G and edge computing in V2X networks and includes comparisons. Section 7 discusses the open issues and outline the future research directions. Finally, Section 8 concludes this survey paper. The structure of the survey paper is given in Figure 1.
###### Abstract  
Today, we capture and store images in a way that has never been possible. However, huge numbers of degraded and blurred images are captured unintentionally or by mistake. In this paper, we propose a geometrical hypothesis stating that blurring occurs by shifting or scaling the depth of field (DOF). The validity of the hypothesis is proved by an independent method based on depth estimation from a single image. The image depth is modeled regarding its edges to extract amplitude comparison ratios between the generated blurred images and the sharp/blurred images. Blurred images are generated by a stepwise variation in the standard deviation of the Gaussian filter estimate in the improved model. This process acts as virtual image recording used to mimic the recording of several image instances. A historical documentation database is used to validate the hypothesis and classify sharp images from blurred ones and different blur types. The experimental results show that distinguishing unintentionally blurred images from non-blurred ones by a comparison of their depth of field is applicable.  
unintentional blur; shifting; scaling; depth of field; blurred image +
Footnote †: journal: Applied Sciences  
1  
class=MSC] [Primary ]60F10, 60  
images in which there are two different depth surfaces. An independent method from geometrical optics is used to detect the depth surfaces from a single image. The DOF of each image is estimated from the position of the depth surfaces. We also show the feasibility of detecting unintentionally blurred images from non-blurred ones by comparing their depth of field. The paper is organized into eight sections, including the present section. We review previous works in Section 2. The relation between blurring and DOF based on geometrical optics is considered in Section 3. The hypothesis is presented in Section 4. Furthermore, the object depth modeling is presented in Section 5. The blur classification is investigated in Section 6. Experimental results are shown in Section 7. Finally, we discuss our approach and conclude the paper in Section 8.
## 3 Test Results and Discussion
### Permeability  
To evaluate the permeability of the PAC mixtures, permeability coefficients in both transverse and vertical directions of the same specimen were measured in this study. From the test results (average for two replicates) shown in Figure 7, it can be seen that there is a positive correlation between permeability coefficient and air void and the transverse permeability coefficient (T) is larger than vertical permeability coefficient (V). The points of four kinds of PAC10 mixture close to the regression line, but the point of PAC-13 above regression line obviously, means that use of smaller aggregate size may reduce the mixture permeability. The PAC10-I4 had the largest permeability coefficient in both vertical and transverse directions, while PAC10-C had the smallest permeability coefficient. Compared with the conventional PAC10-C mixture, the three novel PAC10 mixtures showed better permeability. However, the permeability of the novel PAC10 mixtures decreases with the increasing content of the mineral fillers. Under the condition of optimum asphalt content, the permeability of PAC10-I6 in both vertical and transverse directions are close to those of PAC13.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{3}{*}{**Mixtures**} & \multicolumn{2}{c}{**Flexural Strength**} & \multicolumn{2}{c}{**Flexural Strain at Failure**} & \multicolumn{2}{c}{**Flexural Stiffness at Failure**} \\  & \multicolumn{2}{c}{**(MPa)**} & \multicolumn{2}{c}{**(10\({}^{-3}\))**} & \multicolumn{2}{c}{**(MPa)**} \\ \cline{2-7}  & \begin{tabular}{c} **Average** \\ **Value** \\ \end{tabular} & \begin{tabular}{c} **COV (\%)** \\ **Value** \\ \end{tabular} & \begin{tabular}{c} **Average** \\ **Value** \\ \end{tabular} & \begin{tabular}{c} **COV (\%)** \\ **Value** \\ \end{tabular} & \
\begin{tabular}{c} **Average** \\ **Value** \\ \end{tabular} &
\begin{tabular}{c} **COV (\%)** \\ **Value** \\ \end{tabular} \\ \hline PAC13 & 7.02 & 8.4 & 2632 & 9.5 & 2667 & 10.2 \\ PAC10-C & 6.61 & 9.8 & 3419 & 7.8 & 1933 & 8.4 \\ PAC10-I4 & 5.73 & 8.5 & 2835 & 8.4 & 2022 & 7.1 \\ PAC10-I6 & 6.04 & 6.6 & 2940 & 7.2 & 2055 & 8.1 \\ PAC10-I8 & 6.57 & 6.9 & 3255 & 5.9 & 2017 & 7.3 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Low-temperature bending test results.
# An Image Processing Method for Measuring the Surface Area of Rapeseed Pods
## 3 Results and Analysis
### Analysis of the Accuracy of Measurement
#### 3.1.2 Comparison of the Results of the Other Four Measurement Methods with the 3-D Method  
Single pods of the test samples described above were measured using the Clark formula, Leng formula, flattening scanning, and quasi-cylinder side area methods. A comparison with the measurement results of the corresponding 3-D method indicated significant measurement errors in the four methods. The flattening scanning method was the most accurate, followed by the [PERSON] formula, [PERSON] formula, and quasi-cylinder side area methods, with an average relative error of 16.53%, 19.51%, 22.10%, and 40.89%, respectively, and an average RMSE of 1.64 cm\({}^{2}\), 2.27 cm\({}^{2}\), 2.39 cm\({}^{2}\), and 3.90 cm\({}^{2}\), respectively. An analysis of the accuracy of the other four measurement methods is shown in Table 2. The flattening scanning method was relatively accurate because it involved the direct measurement of fully flattened pods. However, the pods were difficult to flatten completely because of the irregular bulge of the epidermis. In addition, the beak easily fell off during the unfolding of the pod epidermis, resulting in the loss of some portions of the epidermal area. Therefore, the value of the measured result was smaller than that of the corresponding 3-D area. The [PERSON] formula method is similar to that of the [PERSON] formula method, whose principal goal was to indirectly measure the seed pods by establishing the regression model between the pod length, width, and surface areas. The large relative error was because the cultivars and morphological characteristics of the pods used for modeling with the two methods were substantially different from those used in this experiment. For example, the rape cultivars used in the [PERSON] formula method were spring _B. napus_ and spring _B. campestris_, while the cultivar used in this experiment was winter _B. napus_. Therefore, when the surface area of the pods was measured using similar coefficient regression methods, the corresponding regression model should be established for the pod group from a particular cultivar and with a certain shape range before measurement. This is the so-called \"one measurement and one coefficient\" principle. In addition, the \"actual surface area of pods\" referred to in the regression model established using the [PERSON] and [PERSON] formula methods could be inaccurate owing to the limitation of measurement conditions at that time. The largest error in measurement of the quasi-cylinder side area method could be explained by the highly slender beak of the pods and the position close to the pod handle. The side area is smaller than the cylinder with the average fruit width. Moreover, the cross-sections of the pods were oval or irregular and not a regular circle, resulting in a measured value larger than the 3-D area. Therefore, the four methods could be used directly to accurately measure the pods in this experiment.
## 2 Materials and Methods  
### ICE Imaging and the Necessity of Roll Angle Prediction  
ICE is a real-time imaging modality that provides high-resolution visualizations of cardiac structures and allows for continuous monitoring of catheter positioning within the heart. It is well-tolerated by patients and has a reduced need for fluoroscopy and general anesthesia. It is commonly used for procedures, such as atrial septal defect closure and catheter ablation of cardiac arrhythmias and has an expanding role in other procedures [20]. ICE imaging uses ultrasound technology to produce images of the inside of the heart. A small, flexible catheter with a transducer at the tip is inserted into a blood vessel and guided to the heart. The transducer emits high-frequency sound waves, which bounce off the heart structures and return to the transducer as echoes [21]. These echoes are then converted into images that can be viewed on a monitor.  
The roll angle is a crucial parameter that impacts the accuracy of the ICE imaging process during cardiac procedures. It influences the viewing orientation of the transducer, which will affect the speed, safety, and outcome of the procedure. The field of view of an ICE catheter is 90\({}^{\circ}\), and thus, a 5-15\({}^{\circ}\) degree error will not significantly impact the physician's ability to orient the catheter during the procedure, given that they are still able to visualize the live display of the ICE monitor. However, if the catheter is being used in a closed-loop robotic system, a wrong angle can lead to undesired consequences, such as a misdiagnosis, puncture, or improper delivery of a device. Similarly, the accurate prediction and display of the roll angle within an AR/MR system is imperative for providing the physician with the best possible representation of the catheter's position and orientation during a procedure. Moreover, this technology can also provide an interactive platform for physicians to collaborate and discuss the patient's condition and treatment plan, leading to improved patient outcomes.
# Study on Effects of Energy Deposition and Thermal Shock Wave by Electron Beam Irradiation
## 4 Numerical Simulation of Radiant Thermal Shock Wave of Electron Beam  
### Calculation Conditions  
The target material is carbon phenolic. The intensity of the pulsed electron beam is triangularly distributed (see Figure 12), the pulse width is around \(\tau_{0}\), and the average energy of the electron beam is 0.6 MeV. The incident intensity of the electron beam is:  
\[F(t)=\left\{\begin{array}{ll}\frac{4F_{0}}{\tau_{0}^{2}}t,&0<t<\frac{\tau_{ 0}}{2}\\ \frac{4F_{0}}{\tau_{0}^{2}}(\tau_{0}-t),&\frac{\tau_{0}}{2}<t<\tau_{0}\\ 0&t>\tau_{0}\end{array}\right. \tag{17}\]  
where \(F_{0}\) is the energy density of incident electron beam, in unit J/cm\({}^{2}\). If the energy deposition of single-energy electrons in the target is denoted as \(Ec(r)\), and the dimension is cm\({}^{2}\)/g, the specific energy deposition rate of the electron beam with an intensity of \(F(t)\) is \(F_{0}\).  
\[E_{R}(r,t)=F(t)Ec(r) \tag{18}\]  
The energy conservation equation is:  
\[\frac{\partial E}{\partial t}+(\sigma+q)\frac{\partial V}{\partial t}=E_{R}(R,t) \tag{19}\]  
The thermal shock wave of a given material can be obtained by substituting \(E_{R}(r,t)\) into the energy conservation equation.
# Evaluation of Non-_Saccharomyces_ Yeast for Low-Alcohol Beer Production
## 3 Results and Discussion  
### Microbial Analyses  
#### 3.1.1 Sugar Utilization  
All of the examined yeast species were found to ferment glucose to varying degrees. Regarding the sucrose, most of the studied yeast showed the ability to at least partially ferment this sugar (Table 1). As stated in the literature data, _M. pulcherrima_ strains should not be able to ferment maltose or sucrose [19]. The lack of maltose fermentation is consistent with the literature data. However, some authors, such as [PERSON] et al. [29] and [PERSON] [30], have found strains of _M. pulcherrima_ which are able to ferment maltose. Other authors, such as [PERSON] et al. [31], report a lack of maltose fermentation ability in these yeast species. It suggests that these yeasts are characterized by some interspecies variability regarding the utilization of this sugar. Regarding the sucrose, the yeast of _Metschnikowia pulcherrima_ species was highly varied in this regard, where 6/9 of the strains fermented sucrose, which is not consistent with the data provided by [PERSON] et al. [19], where this species should not ferment this sugar. Of the _H. uvarum_ species, one strain was found to ferment sucrose, and only to a low degree. According to the literature, _H. uvarum_ species should not ferment sucrose [19]. _Z. meyereae_ species are known to show variable utilization of sucrose, and maltose [32]. The studied strains utilized glucose, but did not utilize maltose. Lactose was not fermented by any of the yeast species, even by _K. lactis_ (KL1) yeast strain. Not all of the _K. lactis_ yeasts show the ability to ferment lactose. The genes responsible for that are LAC4 and LAC12, which encode \(\beta\)-galactosidase and lactose permease, which probably were missing or non-functional in the evaluated strain [33; 34]. Overall, maltose was not fermented by any of the non-_Saccharomyces_ yeast species studied, except WA1 (Table 1). In _S. cerevisiae_ yeasts, maltose fermentation ability is linked to an active transport of this sugar via the plasma membrane, followed by its intracellular hydrolysis by maltases. The ability to ferment maltose is dependent on a series of unlinked telomere-associated MAL loci. However, there is very little known on the biochemical and genetic background of non-_Saccharomyces_ yeast maltose fermentation ability [35]. In summary, the aim was to find yeast species which do not ferment maltose but can ferment glucose and saccharose. Such yeasts should ensure a beer with low levels of alcohol. The inclusion of lactose in the tests was mainly due to _K. lactis_ strain, which was found to not ferment this sugar. This sugar is sometimes used as an additive in some types of beers [36].
# A New Internet of Things Hybrid VLC/RF System for m-Health in an Underground Mining Industry
## 3 State of Art
The received signal, which includes multi-user data, is separated by the message-passing algorithm with high reliability and is simultaneously reorganized for transmission to a user interface. In [30; 31; 32], VLC system designs for portable patient monitoring devices are presented; it is a two-way communication system, where downlink communication uses VLC, while uplink communication uses infrared. In [33] an integrated system is proposed through Power Line Communications (PLC) and VLC with Orthogonal Frequency Division Modulation (OFDM) for indoor hospital applications. In [34] a hybrid system of RF communication and VLC with double-hop is modeled to provide a solution to communicate the results of laboratory tests to patients in a short time. As has been shown, e-Health research in OWC systems has mainly focused on unidirectional biosignal transmission systems from a single user, unidirectional systems from multiple users, and hybrid transmission systems that allow bidirectional biosignal communication. In this context, it is important to consider that all these works have been developed in hospitals or common indoor environments where the systems are static and mobility is not necessary. In the application scenario described in this article, a VLC link is used for the downlink, while an RF link is used for the uplink. This approach offers several advantages compared to previous methods. The use of VLC for downlink communication provides high positioning precision, and unlicensed operation, and does not present radio frequency-based interference, making it suitable for indoor environments. Furthermore, the VLC system does not pass through walls, providing a level of security against potential hackers and electromagnetic interference, which is not the case with RF technologies [15; 16; 17; 18]. On the other hand, RF technology is used for uplink communication due to its wide coverage and mobility support, making it suitable for transmitting data from the monitoring center to the network and the Internet. This combination of VLC for the downlink and RF for the uplink leverages the strengths of each technology to optimize communication in the given application scenario. Therefore, the use of VLC for downlink and RF for uplink in this scenario provides a balance between precision, security, and coverage, which is advantageous compared to previous methods that may have relied solely on RF or other wireless communication technologies.
# A Study on Design Requirement Development and Satisfaction for Future Virtual World Systems
###### Abstract  
Virtual worlds have become global platforms connecting millions of people and containing various technologies. For example, No Man's Sky (nomanssky.com), a cross-platform virtual world, can dynamically and automatically generate content with the progress of user adventure. AltspaceVR (altrv.com) is a social virtual reality platform supporting motion capture through Microsoft's Kinect, eye tracking, and mixed reality extension. The changes in industrial investment, market revenue, user population, and consumption drive the evolution of virtual-world-related technologies (e.g., computing infrastructure and interaction devices), which turns into new design requirements and thus results in the requirement satisfaction problem in virtual world system architecture design. In this paper, we first study the new or evolving features of virtual worlds and emerging requirements of system development through market/industry trend analysis, including infrastructure mobility, content diversity, function interconnectivity, immersive environment, and intelligent agents. Based on the trend analysis, we propose a new design requirement space. We, then, discuss the requirement satisfaction of existing system architectures and highlight their limitations through a literature review. The feature-based requirement satisfaction comparison of existing system architectures sheds some light on the future virtual world system development to match the changing trends of the user market. At the end of this study, a new architecture from an ongoing research, called Virtual Net, is discussed, which can provide higher resource sufficiency, computing reliability, content persistency, and service credibility.  
virtual reality; augmented reality; virtual world; trend analysis; design requirement; distributed architecture +
Footnote †: journal: Future Internet