esa-sceva/satcom-chunk-collection huggingface dataset:
# A Short-Term Forecasting Method of Inter-Frequency Clock Bias for GPS Block IIF Satellites
## 3 Results  
The IFCB amplitude of the BDS-3 and Galileo satellite systems varied in magnitudes of less than 2.0 cm, with negligible effects on multi-frequency PPP localization [14]. The BDS-2 satellite system's change magnitude was approximately 4.0 cm, and PPP could be implemented by reducing the weight of the third-frequency observation value [16]. However, the IFCB change magnitude of GPS Block IIF satellites reached 20 cm, which must be corrected. Therefore, this study only focused on the modeling forecast of GPS satellites. We first estimated the IFCB of each GPS Block IIF satellite using global uniformly distributed GNSS continuous tracking stations. Subsequently, based on the analysis of IFCB time-varying characteristics, combined with the lag characteristics of the IGS final precise ephemeris product, a short-term prediction model was proposed for the GPS Block IIF satellites. The software used to implement IFCB estimation and forecasting was developed by our team based on the MATLAB tool.
## 2 Concept of \"Quantum Filigran\" Based on Strong-Coupling  
### Physically Unclonable Functions  
A physically unclonable function (PUF) is a physical structure that is widely used as a unique identifier for various objects. PUFs depend on the uniqueness of their physical microstructure [9]. Generally, PUF microstructures depend on random physical factors introduced during manufacturing to create a unique response, or on biologically induced randomness (cellular noise) during the morphogenesis of natural photonic structures [9; 10]. These factors are unpredictable and uncontrollable, which makes it virtually impossible to duplicate or clone the structure. However, the dependence of PUF on modern colloidal or biological self-assembly processes makes this approach, in many cases, complicated and limited. In this article, we offer an entirely different approach that can be used for authentication and marking based on quantum filigran where uniqueness is achieved by controlling the light-matter interaction in the strong-coupling regime. The advantage of the present method, besides its uniqueness, is that it also offers a fast and unique read-out that could be exploited for different sensing and marking applications at large scale. The first example of quantum PUF can be traced back to [PERSON] quantum money protocol [11] which is based on the quantum no cloning theorem. Here, we propose a semi-classical protocol in which quantized light-matter interaction plays a prominent role, the \"quantum filigran\".
# A Fast Parallel Random Forest Algorithm Based on Spark
## 3 Improved Random Forest Algorithm  
In this section, we optimize the traditional random forest algorithm from two aspects including the following: (1) A new Gini coefficient is defined to reduce the impact of feature redundancy on classification accuracy. (2) An approximate equal-frequency binning method is proposed to optimize the number of candidate split points of continuous features and effectively reduce the number of Gini coefficient calculations.  
of feature redundancy on classification accuracy. To this end, a new Gini coefficient with low feature redundancy is defined as follows:  
\[Gini(D,a,F)=\left[\frac{|D_{1}|}{|D|}Gini(D_{1})+\frac{|D_{2}|}{|D|}Gini(D_{2}) \right]-Gini_{aF}(D). \tag{6}\]  
Obviously, if the redundancy relationship between feature \(a\) and other features is small, then \(Gini(D,a,F)\) is small, too. This means that feature \(a\) is highly likely to be selected as the split feature. A simple example is shown in Table 1.  
There are 15 samples in Table 1, which include 3 conditional features and 1 decision feature. Features \(a\), \(b\), and \(c\) represent \"age\", \"have a job\", and \"credit status\", respectively. To simplify the next description, some digital marks are also adopted to represent the related feature values such as 1, 2, and 3 meaning youth, middle aged, and old age, respectively. The related values of \"have a job\" are represented by 1 and 2, which stand for yes and no, respectively. The values of \"credit status\" are represented by 1, 2, and 3, which stand for very good, good, and generally, respectively.  
For the traditional calculation method, the Gini coefficient of feature \(a\) is calculated by formula (3); it has \(Gini(D,a=1)=0.44,Gini(D,a=2)=0.48,Gini(D,a=3)=0.44\). The Gini coefficient of feature \(b\) is as follows: \(Gini(D,b=1)=0.32\). The Gini coefficient of feature \(c\) is as follows: \(Gini(D,c=1)=0.36,Gini(D,c=2)=0.47,Gini(D,c=3)=0.32\). Since \(Gini(D,b=1)\) and \(Gini(D,c=3)\) are the smallest coefficients, both feature \(b\) and \(c\) are thus considered as the best split features, and \(b\)=1 and \(c\)=3 are the best split points, respectively.  
According to formula (1), \(Gini(b)=0.44,Gini(c)=0.658\). According to formula (4), \(Gini(b|a)=0.427,Gini(b|c)=0.407\), it has \(Gini_{bF}(D)\)=0.023. At the same time, \(Gini(c|a)=0.587,Gini(c|b)=0.627\), it has \(Gini_{cF}(D)=0.051\). According to formula (6), \(Gini(D,b=1,F)=0.32-0.023=0.297,Gini(D,c=3,F)=0.32-0.051=0.269\). Finally, feature c is chosen as the best split feature, and c=3 is the optimal split point. Obviously, feature c has lower redundancy compared to other features.
# Minimum Audible Angle in 3 rd-Order Ambisonics in Horizontal Plane for Different Ambsonic Decoders
## 2 Background  
In spatial sound reproduction, an ambisonic decoder is responsible for the conversion of encoded spatial information and its distribution to loudspeakers. [PERSON] [4], credited with developing ambisonic technology, noted that designing a decoder that would account for all psychoacoustic variables would require extensive computational resources. However, with current technological advancements, this limitation is no longer considered significant [6].  
In the theory of localisation in the ambisonic decoder design, the internal auditory system is treated as a black box, while external mechanisms can be conceptualised as analogous to pressure and gradient-pressure microphones [4], as schematically depicted in Figure 2.  
Figure 2: A human hearing system in an analogy to a pressure (large circle) and a velocity (figure-of-eight) microphone. Adapted from [18].  
These simplifications allow for choosing reduced parameter sets while enabling the design of perceptually effective decoders. [PERSON] introduced two critical models for these mechanisms: the velocity model and the energy model. In practical implementation, both the velocity vector \(\mathbf{r}_{V}\), sometimes referred to as Makita localisation, and the energy vector \(\mathbf{r}_{\text{E}}\) must be addressed. Further enhancements of perceptual performance are possible to achieve but are not fundamental to basic functionality. To construct perceptually accurate sound fields, decoders should follow these principles (in order of importance) [4]:  
* High frequencies must converge in the source direction (energy vector);
* Maintain constant amplitude gains for all directions;
* Ensure equivalence in the perceived direction for both high and low frequencies;
* Provide constant energy gain for all directions;
* Accurately reproduce wavefront direction and velocity at low frequencies (velocity vector).  
[PERSON]'s vector models characterise sound field properties at the listener's position. All aforementioned aspects should be integrated into the decoder design to successfully implement the \"majority verdict\"--an auditory direction resolving mechanism in which the human auditory system localises the sound source based on many available cues, choosing the ones that are in agreement [4]. Decoders fulfilling these requirements are classified as \"two-band\" or \"Vienna decoders\" [5]. The complexity of the implementation varies according to the specific loudspeaker configuration. The spherical \(t\)-designs are considered optimal [19], as they offer simplifications to numerical integration on a sphere for polynomials of degree \(2N\leq t\)[20]. The investigation in this study, however, focuses on a system that does not constitute a \(t\)-design configuration, in which case certain decoder implementations may exhibit equivalent performance characteristics [6].
# Browser Forensic Investigations of WhatsApp Web Utilizing IndexedDB Persistent Storage
## 2 Related Works
Similarly, web application information extraction involves using FTK (Forensic Toolkit) Imager to obtain Google Chrome SQLite Database files for history, cache, and web session information. The persistent storage information including IndexedDB storage is not included in the research. [PERSON] [14] conducted a study to locate WhatsApp artifacts in both messenger and web client applications. For the WhatsApp Web application Windows and Mac operating systems with Chrome, Firefox and Safari browsers were covered. The study focused over the log file WhatsApp Web keeps for browser records and presented artifacts such as cached profile pictures and history logs for value to forensic investigations. Even though the artifacts from Web Storage were covered in detail, no detailed listing of IndexedDB artifacts were presented. The study stated the fact that web application was not keeping sent text messages in the client-side storage. The records of when the text messages were sent and when a voice/video call were active were not covered nor processed for verification purposes to investigations of traditional browser storage technologies. [PERSON] et al. [15] utilized internal memories of Android phones for the forensic investigations of WhatsApp and Viber. UFED (Universal Forensic Extraction Device) was used for file extraction and the Sqlite database browser was used for the investigation of the data. The research was conducted on five Android phones with three different operating systems installed: Froyo 2.2, GingerBread 2.3, and Ice-Cream Sandwich 4.0. In the paper, the authors discussed that based on the logs and history files investigated, forensically significant data were detected for WhatsApp and Viber in all different operating systems of Android phones. [PERSON] et al. [16] presented evidence collection methods for forensic investigations on WhatsApp, Viper, Skype, and Tango instant messaging applications. The research was performed on both iOS and Android operating systems. The definition of types of artifacts that can be found in the four instant messaging applications was listed along with the methodologies of extractions. Additionally, a limited number of studies focused on IndexedDB forensics and security without targeting WhatsApp Web artifacts; [PERSON] et al. [6] introduced a tool called BrowStExPlus that analyzed IndexedDB artifacts of Mozilla Firefox, Google Chrome, and Internet Explorer. [PERSON] et al. [17] investigated database vulnerabilities that are introduced with web browser persistent storage technologies such as IndexedDB. [PERSON] and [PERSON] [18] presented a comparison of IndexedDB and Android SQLite with a security evaluation. Overall, research on WhatsApp security and forensics remains mostly focused on mobile devices. In addition, only a handful of research has been conducted on IndexedDB, excluding WhatsAppwhich is still considered an emerging technology. Therefore, research on the WhatsApp Web and its forensic investigation based on web browser IndexedDB technology is a dire need.
## 5 Conclusions  
In this study, an effective OMLIDS-PBIoT technique was advanced with the utilization of the BC and ML models for accomplishing security in the smart city environment. The presented OMLIDS-PBIoT technique employs different stages of subprocesses, namely pre-processing, GEO-FS, RVFL-based classification, and HBO-based parameter optimization. Moreover, BC technology is exploited for secure data transmission in the IoT-enabled smart city environment. The performance validation of the OMLIDS-PBIoT technique is performed using benchmark datasets, and the outcomes are inspected under numerous aspects. The experimental outcomes demonstrated the superiority of the OMLIDS-PBIoT technique over recent approaches. Thus, the OMLIDS-PBIoT technique could be exploited as a proficient tool to accomplish security in the smart city environment in sectors such as healthcare, smart buildings, transportation, etc. In upcoming days, the performance of the OMLIDS-PBIoT technique could be enhanced using hybrid DL classification methods.  
Conceptualization, A.A.-Q. and S.S.A.; methodology, F.A.; software, R.M.; validation, A.A.-Q. and M.O.; investigation, R.M.; resources, F.N.A.-W.; writing--original draft preparation, F.N.A.-W.; M.A.D. and M.A.-S.; writing--review and editing, N.N. and M.O.; visualization, M.O.; supervision, F.N.A.-W.; project administration, S.S.A.; funding acquisition, F.A. All authors have read and agreed to the published version of the manuscript.  
The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through Large Groups Project under grant number (71/43). Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R77), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. The authors would like to thank the Deanship of Scientific Research at Umm Al-Qura University for supporting this work by Grant Code: 22 UQU4210118 DSR19.  
Not applicable.  
Data Availability Statement:Data sharing not applicable to this article as no datasets were generated during the current study.  
The authors declare that they have no conflict of interest. The manuscript was written through contributions of all authors.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Methods** & **Training Time (s)** & **Testing Time (s)** \\ \hline OMLIDS-PBIoT & 35 & 20 \\ \hline AIMMFIDS & 55 & 25 \\ \hline DBN-IDS & 61 & 34 \\ \hline LSTM-IDS & 68 & 34 \\ \hline RNN-IDS & 69 & 35 \\ \hline PTDSAE-IDS & 71 & 36 \\ \hline DPCDBN-IDS & 73 & 37 \\ \hline AKNN-IDS & 79 & 42 \\ \hline DT-IDS & 80 & 45 \\ \hline AB-IDS & 81 & 43 \\ \hline RF-IDS & 83 & 45 \\ \hline \hline \end{tabular}
\end{table}
Table 5: TRT and TST analysis of OMLIDS-PBIoT technique with existing algorithms.
## 2 Related Works
[33] improve on the use of noise by introducing cloak users that generate messages at the same time as [PERSON] to increase the difficulty of finding communication patterns. Finally, other authors introduced Noise SDA (NSDA) [34], which analyzes the frequency of message co-occurrence between a target user and other users, allowing for more effective filtering of irrelevant noise. However, the previous studies used simulated data to validate their findings and evaluate their performance. Despite these advancements, the studies presented before have applied their algorithms to overly controlled or unrealistic scenarios, often assuming that all users have the same number of friends or communicate with uniform probability. [PERSON] et al. [35] developed a specific statistical disclosure attack for voice calls and established that this attack does not perform well in the general disclosure of call relationships. The authors try to determine communication between all users, not only between [PERSON] and its friends. In addition, the authors claimed to be the first to present a statistical disclosure attack in the context of anonymous voice calls, which is a different type of social network. The research presented here overcomes the limitations introduced by assuming the same number of contacts for each user and constant probability of communication between them. Two earlier works have already contributed to this effort and have allowed the development of the TSDA-EM algorithm. The evolution between these proposals is further described in Section 4.2. A detailed analysis of the algorithm introduced here against most of the research described above, in terms of key metrics such as accuracy, number of [PERSON]'s friends, and data used for evaluation, has been included in the Discussion Section 6.
## 4 Conclusions  
In order to remove the temperature effect from the corrosion potential, the GPR method was applied in this study. The corrosion potential was measured within an uncontrolled air temperature environment. The corrosion potential results showed the temperature affected the corrosion potential. Thus, removing the temperature effect from corrosion potential with GPR. The results showed a good performance of GPR. Based on these results, our conclusions are drawn as follows:  
1. In the uncontrolled air environment, the corrosion potential was highly sensitive to the environmental conditions. Its fluctuation was evidence of the environmental effects. In particular, because the air temperature was not controlled, the rebars showed that the temperature had an effect on the specimens. In addition, the corrosion potential behavior showed different trends by rebar diameter.
2. It was confirmed that temperature is an important factor for measuring the corrosion potential. This evidence was the behavior of corrosion potential with fluctuation. From these results, temperature has to be considered when measuring the corrosion potential.
3. The GPR with a kernel performed close to the ML with a high R\({}^{2}\) value. This confirmed the usability of GPR in corrosion analysis, especially in removing the temperature effect. The derived GPR model was able to produce a reliable R\({}^{2}\) and RMSE. Therefore, the GPR method can be appropriate for corrosion analysis considering the temperature effect.  
Figure 6: The results of removing the temperature effect: (**a**) D10; (**b**) D13; (**c**) D16; (**d**) D19.  
**Author Contributions:** [PERSON] and [PERSON]-[PERSON] conceived and designed the experiments; [PERSON] and [PERSON] performed the experiments; [PERSON] and [PERSON] analyzed the data; S.S.K. supervised this study; [PERSON] wrote the paper. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry and Energy (MOTIE) of the Republic of Korea (No. 20183010025510).  
**Conflicts of Interest:** The authors declare no conflict of interest.
# On the Trade-Off between the Main Parameters of Planar Antenna Arrays
## 3 Sparse Array Synthesis
### Directivity Constraint  
A possibility to achieve a better sparse array consists of adding a directivity constraint during the synthesis.  
It has been recalled that the directivity can be written as Equation (10). Since the form \(\mathbf{a^{t}Sa}\) is a quadratic form, a constraint like \(D\geq D_{target}\) turns out to be a convex constraint that can be added with minimum effort to minimizations Equations (12) and (17).  
As an example, we could start from the higher directivity layout of Figure 2, which presents 665 elements, and impose as a constraint that the broadside directivity is always not lower than the directivity of the fully populated starting array.  
The result of this synthesis is provided in Figure 6; the achieved layout employs 310 elements and shows an excitation dynamic \(\rho=8.8\) dB, the minimum inter-element distance is \(0.48\lambda\), and the computation time was about eight hours. The beam-width and side-lobe level specifications are perfectly verified, even for the most scanned beam, and the directivity of the broadside beam is 29 dB, like the directivity of the fully populated array.  
Figure 5: The 213 elements sparse layout. Left subplot: position and normalized excitation amplitude (dB) of the synthesized layout; center subplot: normalized Array Factor in the \(uv\) plane; right subplot: some relevant cuts. Negative values of \(w\) are related to the cuts \(\phi^{\prime}=\phi+\pi\).  
It is also worth underlining that the number of radiators is much larger than the previous sparse layout, but we are indeed using a much lower number of radiating elements than the fully populated array, 310 instead of 665 (a reduction of more than 53%).
## 3 Results and Discussion
### Antioxidant Activity  
#### 3.5.1 DPPH Assay Analysis  
Figure 5 shows the results of the antioxidant DPPH assay for WFP and WFSP. The results demonstrate that methanolic extract of WFSP and WFP showed DPPH inhibition activity of 39.12 \(\pm\) 0.33% and 31.67 \(\pm\) 0.30%, respectively. The present findings confirmed that methanolic extract of WFSP showed better results compared to WFP. Our results lead to a similar conclusion with the findings of [PERSON] et al. [35], who revealed that 80% methanolic extract of Lady Rosetta and Lady Claire cultivars of potato peel powder presented the maximum antioxidant DPPH activity of 3.51 \(\pm\) 0.00 and 1.75 \(\pm\) 0.05 mg TE gdb\({}^{-1}\). [PERSON] et al. [41] experimented on different sweet potato varieties and suggested that the JM variety submitted the best DPPH and ABTS radical scavenging activity of 48.15 and 80.0 mg TE/g DW after heat treatment with pre-ethanol (80%).  
Figure 4: The total flavonoids content (TFC) and total phenolic content (TPC) of WFSP and WFP. Different letters in the column represent the significant difference based on the Tukey HSD test (a = _p_\(\leq\) 0.05, b = _p_\(\leq\) 0.01).
## 6 Current Challenges and Future Prospects
### Industry 5.0 as a Way to Overcome the Challenges of Industry 4.0  
Industry 5.0 not only expands upon Industry 4.0's base but also more successfully addresses its problems. Some of these challenges include the following:  
_Supply chain issue_: Supply Chain 4.0 is technology-driven, focusing on strategies, disruptive technologies, and enhancing supply chain performance through mass customization and efficiency improvements. In contrast, Supply Chain 5.0 emphasizes a balanced integration of human involvement and technology, seeking to maintain and enhance Supply Chain 4.0's advantages while placing a greater emphasis on sustainability. Industry 5.0 leverages cutting-edge capabilities of AI and cobots, with a major emphasis on supply chain management sustainability [14; 197]. _The challenge of data security_: In Industry 4.0, issues like stealing data and hacking came up with IoT, but Industry 5.0 has dealt with these. Industry 5.0 uses a special blockchain system to make the Internet of Things in industries more secure, helping to gather data better for smart manufacturing. This helps focus on certain areas of value and lowers the chance of network problems. Using smart contracts with this blockchain system makes things more self-sufficient and green, cutting down the need for outside help [36]. Resilient manufacturing strategies are crucial for data security, especially for IoT, which contains sensitive data [14; 34; 35]. _Issue of technical integration_: A notable challenge of Industry 4.0 is managing the rising digitalization. However, Industry 5.0 shifts focus towards human-centric approaches, blending human creativity with machine precision to enhance productivity and performance. Furthermore, Industry 5.0 can improve product quality by using robots to perform repetitive tasks [13; 14]. _Human resource issue_: Industry 4.0 brought automation to traditional manufacturing, requiring thorough training for workers. Conversely, Industry 5.0 prioritizes human-centric methodologies, emphasizing the enhancement of collaborative interactions between human operators and robotic systems. Cobots play a vital role by collaborating with humans, enhancing productivity and efficiency. This collaboration allows workers to focus on value-added tasks while reducing involvement in monotonous or hazardous jobs. However, predictive maintenance is crucial to prevent breakdowns in these machines [14; 37]. While Industry 4.0 is centered on digitalization, Industry 5.0 is about promoting teamwork between digital technologies and human skills in critical and creative thinking.