esa-sceva/satcom-chunk-collection huggingface dataset:
# Backscatter Communications: Inception of the Battery-Free Era--A Comprehensive Survey
## 9 Challenges and Future Directions  
BackCom for next-generation 5G wireless has the potential to extend the boundary lines of ubiquitous computing, WSN, IoT, machine-to-machine communication, D2D communications, etc. BackCom-based computing is a new and emerging field of wireless communications [217]. There are many advantages of BackCom in various applications, but there are limitations, too. This section covers open problems and future research directions for BackCom.  
\begin{table}
\begin{tabular}{p{56.9 pt} p{284.5 pt} p{284.5 pt}} \hline \hline
**Subsections** & **Ref.** & **Key Points** \\ \hline
**Smart Homes/Cities** & [96][188] & \(\bullet\) Smart posters can broadcast to nearby cars using FM BackCom, and an FM receiver can receive signals. \(\bullet\) Smart homes can monitor the breathing and heart rate remotely using the reflections of radio waves. \(\bullet\) Robots can utilize BackCom signals reflected from furniture and doors for in-house navigation. \\ \hline
**Unmanned Aerial Vehicles** & [180][194][195] & \(\bullet\) The RFLY drone can extend the range of BackCom. \(\bullet\) Opportunities and challenges in UAV-based BackCom are discussed. \(\bullet\) UAVs can be used in rural areas for supplying ambient power to passive nodes. \\ \hline
**BackCom for Bio Medical applications** & [196, 197][198] & \(\bullet\) A WiFi-based gestures can be recognized. \(\bullet\) The reflection of WiFi signals with machine learning can identify the emotions and heartbeats. \(\bullet\) A brain machine interface for BackCom was devised. \\ \hline
**Backcom for Logistics** & [10][201] & \(\bullet\) An array of tags was employed to obtain three-dimensional orientation tracking. \(\bullet\) Heavy item tags can be read without being picked up. \\ \hline
**BackCom in Textiles** & [96][203][201] & \(\bullet\) Connectivity of the T-shirt was made by an FM radio station using BackCom. \(\bullet\) Project Jacquard was used for interactive digital textiles. \\ \hline
**Environmental Monitoring** & [130][208] & \(\bullet\) A WiFi-powered camera and temperature sensor were used to sense the environment. \(\bullet\) BiS radio-enabled sensors for environmental monitoring. \\ \hline
**Body Area Sensor Net** & [10][138][138] & \(\bullet\) A BackCom lens can measure glucose in tears. \(\bullet\) BackCom for a body area sensor network was proposed. \\ \hline
**Vehicle Monitoring** & [96][211][96] & \(\bullet\) BackCom-based smart signboards can communicate to vehicles to reduce accidents. \(\bullet\) Passive nodes in aerospace vehicles are needed. \\ \hline
**Backscatter Sensor Network** & [212][213][214][215] & \(\bullet\) A system was implemented to receive continuously backscattered signals reflected from a WSN. \(\bullet\) RFID and WSN were integrated. \(\bullet\) Three forms of networks were designed for RFID-based WSNs. \(\bullet\) An RFID-based wireless passive sensor network was designed to eliminate the limited battery life issue. \\ \hline \hline \end{tabular}
\end{table}
Table 12: Summary of BackCom applications.
## 5 Extending the Mediator-Wrapper Architecture
### Quantitative Analysis on Scenarios
#### 5.3.5 Analysis of the Shift Costs  
With the shift costs evaluated, a more concise comparison of architectures can be made. Table 2 displays all the shift costs for each scenario and architecture.  
The first scenario demonstrates that in the MMW architecture, the addition of a new type of representation is only dependent on the implementation and deployment of a mask component. The other two architectures depend on mediator components. The 1 LMW shift cost noticeably depends on the number of connected wrappers--to emphasize, for adding a representation type. The 2 LMW and MMW architectures are not at such a disadvantage, their difference being the type of component added to the system. Since a mask is less costly to implement and deploy than a mediator, the overall shift cost in scenario 1 is lowest in the MMW case.  
The second scenario also shows that the 1 LMW shift cost is dependent on the number of wrappers. The cases of 2 LMW and MMW are again analogous, but a mask is less costly to deploy than a representational mediator. This makes the shift cost of the MMW case the lowest again. As it was discussed earlier in the text, using a mediator just for representation, without using its mediation functionalities, is akin to killing a fly with a cannonball.  
The third scenario shows the shift cost overhead that 2 LMW and MMW have as opposed to 1 LMW when setting up mediation. There is an obvious trade-off in these architectures between the shift cost of adding mediation or representations. To maintain a less costly (and qualitatively simpler) representation addition, the overhead cost of adding mediation is increased. This overhead can be quantified for 2 LMW as  
\[C_{2 LMW}^{overhead}=C_{2 LMW}^{3}-C_{1 LMW}^{3}=C_{Me}^{depl}+C_{Comm}^{Set},\]  
and for the MMW,  
\[C_{MMW}^{overhead}=C_{MMW}^{3}-C_{1 LMW}^{3}=(C_{Me}^{depl}-C_{Me}^{depl})+C_{ Ma}^{depl}+C_{Comm}^{get}\]  
Considering that the MMW mask and mediator are less costly to deploy than the 2 LMW mediator, the overhead cost is reduced in favor of the MMW.  
The fourth scenario shows that the addition of a new wrapper to the MMW system has no effect on the rest of the system hierarchy, as it is also expected of the other MW architectures. The MMW finds itself in no detrimental opposition to the other architectures.
## 2 Design of the Proposed RDA with the EBGs
### Performance of RDA with the EBGs  
In this section, the 5 \(\times\) 5 array of Koch-shaped patch antenna with the EBGs is studied. The inter-element spacing is reduced to as small as 0.4\(\lambda\) to realize a compact size. Figure 7a shows the configuration of the 5 \(\times\) 5 Koch-shaped patch antenna array with the EBGs. For the simulation, a port was used for each antenna element, and all ports were simultaneously excited. Performance outcomes with regard to the active reflection coefficient and the AR of the center element were investigated and presented. A comparison of the reflection coefficients and ARs for the center element of the array with and without the EBGs was conducted, with the results illustrated in Figure 7b. Note that the AR values are observed in the \(+z\)-direction. It is evident that the CP performance of the array without the EBGs was considerably deteriorated due to the strong mutual coupling effects. The minimum AR value was increased to 3.83 dB. In contrast, with the EBGs, the CP performance was significantly improved. Owing to the reduced mutual coupling, the minimum AR value was reduced to 0.31 dB. At the designed frequency of 5.2 GHz, an AR value of 1.20 dB was achieved. In addition, the \(-\)10 dB reflection bandwidth was enhanced with the presence of the EBGs. The radiation patterns, when all ports were simultaneously excited, at 5.2 GHz are depicted in Figure 8 for the two major cutting planes of the \(xz\)- and \(yz\)-planes. With the EBGs to reduce mutual coupling, an approximate gain enhancement of 0.4-0.8 dB was obtained as compared to the array without the EBGs when the radiation pattern is scanned from the broadside to 60\({}^{\circ}\) on each plane. Therefore, the simulated results demonstrated that the presence of the EBGs significantly enhances the CP performance of the RDA despite the fact that the inter-element spacing is reduced to as small as 0.4\(\lambda\).  
Figure 7: **(a)** 5 \(\times\) 5 CP Koch-shaped patch array with the EBGs; **(b)** Simulated results of the reflection coefficients and ARs.
## 5 Conclusions and Future Work  
In this study, we investigated the HRV of two groups of elderly people: cognitively normal and cognitively impaired. The changes in HRV features were significantly affected by the experiment sessions and not by the cognitive status of the subjects. No interaction was observed between the cognitive status and sessions that can affect the HRV. Thus, the two groups have similar HRV responses while playing the serious games. This means that the elderly can experience similar changes in their HRV regardless of their cognitive status. The need to measure HRV to assess for MCI may not be as crucial as we thought.  
Game performance was significantly different between the two groups, with the cognitively normal subjects performing better than the ones who are cognitively impaired. The serious games presented in this study can be useful in assessing cognitive decline in the elderly. This is further corroborated by the use of game performance in the classification of the two groups, achieving an accuracy of 83.33%, compared to the 68.75% using HRV features. While HRV have the potential to be used for classifying cognitive status, game performance can be more accurate. Screening tools such as MMSE and MoCA are easy to administer, but can be affected by the age, educational and cultural background of the patient [7; 69]. From the ML classification results, serious games have the potential of being used as an alternative method for detecting cognitive decline aside from using questionnaires and clinical interviews. This result warrants further development on the design of serious games for assessing cognitive impairment.  
For future studies, a larger sample size for each group would be recommended to confirm or refute the findings presented in this study. Other serious games designed for the elderly can also be used to verify or challenge the findings in this study. In addition, the cognitive domains and their relationship with the ANS activity and other biomarkers can also be explored.  
Conceptualization, C.-J.H. and Y.-T.C.; methodology, C.-J.H., Y.-T.C., M.A.C. and M.-W.H.; signal and data analysis, M.A.C.; supervision, J.-J.H. and M.-W.H. All authors have read and agreed to the published version of the manuscript.  
The authors gratefully acknowledge the financial support from the Ministry of Science and Technology of Taiwan (grant number MOST 108-2634-F-367-001) and the Allied Advanced Intelligent Biomedical Research Center (A2 IBRC) under the Higher Education Sprout Project of Ministry of Education (grant number 13001090182-EDU).  
The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Review Board (or Ethics Committee) of Taichung Veterans General Hospital Taiwan (protocol code SF18297A-1; 16 January 2019).  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
Data Availability Statement: Data is available upon request due to ethical and privacy reasons. The data are not publicly available due to privacy concerns of the subjects.  
The authors declare no conflict of interest.
## 6 Discussion
### Limitations and Future Work  
The study identifies several limitations that necessitate attention in future research endeavors. A primary constraint is the sample size; expanding the number of participants would significantly bolster the confidence and reliability of the findings. Another crucial factor is the trustworthiness of the respondents, particularly given their young age. This study's concentration on kindergarten students and a specific educational subject questions the generalizability of its results. Furthermore, the duration allotted for each participant to view the videos might have been insufficient. The research focused on comparing 360\({}^{\circ}\) videos, conventional videos, and printed materials, but it did not examine other media or technologies, thus leaving unanswered the question of whether 360\({}^{\circ}\) videos outperform these alternatives. Moreover, the study examined a limited set of factors; including additional variables could have provided a more comprehensive understanding of the crucial elements influencing learning outcomes in 360\({}^{\circ}\) videos.  
To advance this line of inquiry, future research must address these limitations, to ensure comprehensive and reliable insights. By incorporating more diverse target populations that vary in age and educational backgrounds and employing larger sample sizes, researchers can obtain more robust insights into emerging similarities or differences when using 360\({}^{\circ}\) videos. This approach is equally applicable to investigating various learning domains and types of applications. To achieve a more comprehensive understanding of the pivotal elements influencing learning outcomes in 360\({}^{\circ}\), additional factors can be examined, such as cognitive load, the quality of learning material, and technical considerations. The inclusion of qualitative data, such as observations and interviews, will further contribute to formulate a thorough understanding. Moreover, longitudinal studies offer a promising avenue for exploring the educational potential of 360\({}^{\circ}\) videos in far greater depth. As previously noted, studies restricted to a limited number of sessions are susceptible to the \"novelty effect\", which could skew results. Addressing these limitations will be instrumental in fully realizing the educational benefits of 360\({}^{\circ}\) videos.
# Chinese Named Entity Recognition of Geological News Based on BERT Model
## 3 Results
### Influence of Model Hyperparameters
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Model** & **Learning_Rate** & **P** & **R** & **F** \\ \hline \multirow{6}{*}{BiLSTM-CRF} & \(1\times 10^{-5}\) & 0.795 & 0.725 & 0.758 \\  & \(2\times 10^{-5}\) & 0.804 & **0.732** & 0.766 \\  & \(3\times 10^{-5}\) & 0.814 & 0.728 & **0.768** \\  & \(4\times 10^{-5}\) & **0.817** & 0.721 & 0.766 \\  & \(5\times 10^{-5}\) & 0.806 & 0.725 & 0.763 \\ \hline \multirow{6}{*}{BERT} & \(1\times 10^{-5}\) & 0.805 & 0.823 & 0.814 \\  & \(2\times 10^{-5}\) & 0.814 & 0.827 & 0.821 \\  & \(3\times 10^{-5}\) & 0.819 & **0.829** & **0.824** \\  & \(4\times 10^{-5}\) & **0.823** & 0.819 & 0.821 \\  & \(5\times 10^{-5}\) & 0.817 & 0.822 & 0.819 \\ \hline \multirow{6}{*}{DistilBERT} & \(1\times 10^{-5}\) & 0.798 & 0.812 & 0.805 \\  & \(2\times 10^{-5}\) & 0.803 & 0.814 & 0.808 \\  & \(3\times 10^{-5}\) & 0.808 & **0.821** & **0.814** \\  & \(4\times 10^{-5}\) & **0.812** & 0.811 & 0.811 \\  & \(5\times 10^{-5}\) & 0.805 & 0.818 & 0.811 \\ \hline \multirow{6}{*}{RoBERTa} & \(1\times 10^{-5}\) & 0.809 & 0.816 & 0.812 \\  & \(2\times 10^{-5}\) & 0.817 & 0.822 & 0.819 \\  & \(3\times 10^{-5}\) & 0.823 & **0.834** & **0.828** \\  & \(4\times 10^{-5}\) & **0.826** & 0.828 & 0.827 \\  & \(5\times 10^{-5}\) & 0.821 & 0.827 & 0.824 \\ \hline \multirow{6}{*}{BERT-BiLSTM-CRF} & \(1\times 10^{-5}\) & 0.821 & 0.823 & 0.822 \\  & \(2\times 10^{-5}\) & 0.832 & 0.833 & 0.832 \\  & \(3\times 10^{-5}\) & **0.839** & 0.838 & **0.838** \\  & \(4\times 10^{-5}\) & 0.834 & **0.838** & 0.836 \\  & \(5\times 10^{-5}\) & 0.834 & 0.825 & 0.829 \\ \hline \multirow{6}{*}{BERT-CRF} & \(1\times 10^{-5}\) & 0.823 & 0.819 & 0.821 \\  & \(2\times 10^{-5}\) & 0.829 & 0.832 & 0.831 \\ \cline{1-1}  & \(3\times 10^{-5}\) & **0.838** & **0.841** & **0.839** \\ \cline{1-1}  & \(4\times 10^{-5}\) & 0.836 & 0.838 & 0.837 \\ \cline{1-1}  & \(5\times 10^{-5}\) & 0.832 & 0.824 & 0.828 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: P, R and F1 scores of the model under different learning rates. The numbers in bold font are the three indicators (P, R, F1) with the highest corresponding scores in each set of experiments.
# Aggregatable Subvector Commitment with Efficient Updates
## 3 The Proposed Scheme
Entering the index \(i\) of the newly added node and adding the difference quotient value \(a_{i}\) requires updating the proof \(\pi_{j}\). Add a new node and the interpolating polynomial changes as follows: \[N^{\prime}(x)=\sum_{i\in[0,n]}a_{i}\cdot w_{i}(x)=N(x)+w_{n}(x)\cdot a_{n}.\] (29)At this point, the quotient polynomial of our computational proofs changes as follows: if \(j\
eq n\),  
\[q_{j}^{\prime}(x)=\frac{N^{\prime}(x)-v_{j}}{x-p_{j}}=\frac{N(x)-v_{j}+w_{n}(x) \cdot a_{n}}{x-p_{j}}=q_{j}+\frac{w_{n}(x)\cdot a_{n}}{x-p_{j}}. \tag{30}\]  
Store \(u_{n,j}=g^{\frac{w_{n}(x)}{\tau-p_{j}}}\) in the public parameter as the update parameter, then \(\pi_{j}^{\prime}=\pi_{j}\cdot(u_{n,j})^{a_{n}}\). Otherwise, we need to call the algorithm the \(\text{Open}(\text{pp}^{\prime},n,\textbf{v}^{\prime})\) algorithm to calculate the proof at position \(j=n\). * AddAllProof\((\text{pp}^{\prime},\{\pi_{j}\}_{j\in[0,n)},(i,a_{i})_{i\in[n,n+l]})\to\pi_{j}^{\prime}\): Input the index \(i\) of the added node and the value \(a_{i}\) of the added difference quotient. If \(j=i\), call the algorithm \(\text{Open}(\text{pp}^{\prime},j,\textbf{v}^{\prime})\to\pi_{j}\), where \(\pi_{j}=g^{q_{j}(\tau)}\). If \(j\
eq i\), return \(\pi_{j}^{\prime}=\pi_{j}\cdot\prod_{i\in[n,n+l)}(u_{i,j})^{a_{i}}\). The above algorithm introduces the specific algorithm construction of the vector commitment scheme based on Newton interpolation polynomial in detail. Compared with the traditional Lagrangian-based vector commitment scheme construction, our scheme innovatively introduces a dynamic node addition mechanism, breaks through the limitation of fixed dimension and enables the vector scale to be flexibly expanded. And in Section 5, its performance is comprehensively evaluated through experiments. The experimental results show that this scheme achieves more flexible dynamic characteristics while maintaining computational efficiency.
## 3 Control Techniques  
The conventional PID controller is executed in various fields of engineering applications owing to its simplicity, reliability, and flexibility in tuning its parameters. The transfer function of the PID controller is \(k(s)=K_{p}+K_{i}/\)s \(K_{d}\) s, where \(K_{p}\), \(K_{i}\), and \(K_{d}\) are proportional, integral, and differential gains, respectively. The function of each part of a PID controller can be described as follows: the proportional part decreases the error responses of the system to disturbances, the integral part rejects the steady-state error, and finally, the derivative part diminishes the dynamic response and improves the system stability.  
The problem in the PID controller is to choose the three parameters to be suitable for the controlled plant. There are many methods to define the parameters of PID controller such as try and error and Ziegler-Nichols methods but most of these methods are rough roads. Therefore, this paper presents a novel CVOA methodology to find the optimal values of the PID controller.
## 3 Results
### Metrics Results  
Certainly, for extra precise performance measurement and comparison, we used three tools that aided us to gather more conclusions. As previously explained, the IAE was used to tune the parameters until this value becomes minimum. The RMSE provides  
Figure 11: The control signal in 2 cycles of a triangular reference with variable amplitude.  
Figure 10: The error generated in 2 cycles of a triangular reference with variable amplitude.  
the accuracy in terms of the error, and because we implemented an SMC-based controller (known for the chattering generated in the control signal), we calculated this value based on the previously explained method. Numerical results of these parameters are summarized in Table 2.  
In regards to the IAE, the QCSMC-ANN indicated a superior performance in the triangular reference, which led to a 53.07% difference in comparison with the PID. Nevertheless, in the sine wave test, it is shown that this value was augmented, as the QCSMC-ANN reached 81.5% more. Additionally, the variable amplitude signal carried with the same trend, as the difference achieved was 33.6% favourable for the proposed algorithm. The RMSE showed a similar manner since the QCSMC-ANN kept the advantage over the PID in both signals granted 46.5%, 79.7% and 38.5% of difference with the triangular, sine and variable amplitude waves, respectively. Lastly, the measured chattering indicates the dominance of the QCSMC-ANN over the PID, and even it emblazons through values of the suitable performance of the control signal; according to the values of 35.6%, 81.8% and 22% of difference in both signals, it is clear that the QCSMC-ANN had less chattering than the PID controller.
# A Novel Approach to Reach Impedance Matching in Wireless Power Transfer Systems
## 1 Introduction
The accuracy of the theoretical calculation was verified by modeling and running a simulation on Ansys Maxwell 16.0. Finally, an experimental setup was built to verify the proposed method in this paper. The method can be used to change the angle of concentric printed spiral coils to simply achieve the optimal impedance matching. This method also ensures the maximum efficiency of a given pair of resonant coils is achieved at different distances. The measured transfer efficiency of the WPT system was improved by \(11\%\) compared to before optimization.
# UAV-Assisted Caching Strategy Based on Content Cache Pricing in Vehicular Networks
## 6 Conclusions  
In this paper, we investigated a UAV-assisted caching strategy based on content cache pricing in vehicular networks. In a traffic scenario consisting of CP, NO, and multiple vehicle users, the CP leases some popular content to the NO for benefits and the NO caches this leased content in RSUs to save expensive backhaul transmission overhead and latency. We analyzed the content delivery process and benefit exchanges between CP, NO, and vehicle users and defined the utilities of CP and NO. Then, the competition between CP and NO was modeled using the Stackelberg game framework and an iteration-based dynamic planning algorithm was designed to find the Stackelberg equilibrium by optimizing the caching decisions of RSUs and the rental prices of contents. Finally, a cache-capable UAV was introduced into the onboard network to cache the content already leased by the NO and a Dijkstra-based path planning algorithm was designed to further increase the total utility of the NO and improve the service quality by optimizing the trajectory of the UAV. The simulation results show that the strategy in this paper can have a reasonable distribution of the benefits of CP and NO, reduce the average request latency, and increase the utility of NO. Compared with [10], the strategy in this paper reduces the total benefit of CP by 2% and increases the total utility of NO by 13% where the benefit of NO is increased by 3% and the request delay is reduced by 27%.  
Figure 9: Performance versus communication radius of RSU. (**a**) Relationship between the total utility of CP and the communication radius of RSU; (**b**) relationship between the total utility of NO and the communication radius of RSU; (**c**) relationship between the benefit of NO and the communication radius of RSU; (**d**) relationship between the average delay and the communication radius of RSU.  
However, there are still several issues in this paper. For example, we assumed that the communication environment was secure and did not consider the possible problems of eavesdropping and information leakage in practice. In our future work, we will further study the information encryption technology in this scenario to further guarantee the security of communication.  
Conceptualization: T.G. and Q.Z.; methodology: T.G.; software: T.G.; validation: T.G. and Q.Z.; formal analysis: T.G.; investigation: T.G.; resources: Q.Z.; data curation: T.G.; writing: T.G.; visualization: T.G.; supervision: Q.Z.; project administration: Q.Z.; funding acquisition: Q.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Jiangsu Provincial Key Research and Development Program (No. BE2022068-2), the National Natural Science Foundation of China (61971239).  
Not applicable.  
The authors declare no conflict of interest.