esa-sceva/satcom-chunk-collection huggingface dataset:
# Automatic Speech Recognition for Uyghur, Kazakh, and Kyrgyz: An Overview
## 4 Advances in Speech Recognition for Uyghur, Kazakh, and Kyrgyz
### Analysis and Discussion
#### 4.3.1 The Importance of Open-Source Data  
From the development history of speech recognition technology for the three languages, we can see that, for any language, no matter when the research was started, fast technical progress is impossible without a standard benchmark including both open-source data and reproducible source code.  
Taking Uyghur as an example, although the studies on Uyghur ASR started as early as the 1990s, most of the research reported results using private data and without the source codes, making reproduction and technical comparison very hard. The consequence is that research on Uyghur is always in a follow-up state and has little contribution to the mainstream research community.  
A standard benchmark is a public platform. On this platform, different technologies can be compared and verified, so it will be easy to verify which technique is effective and which one is a spurious innovation. Famous benchmark databases include TIMIT [154] and WSJ [155] in English and RAS 863 [156] in Chinese. Despite their historical contributions, most of the early datasets are not free. Recently, the open-data movement made a further step: researchers started to publish their data for free and also accompanied by the corresponding source codes for the baselines so that all research groups and individuals can study, communicate, and compare under the same resources and rules. This has significantly promoted technical progress. There are many open-source databases in rich-resource languages, such as LibriSpeech [157], THCHS30 [158], and AIShell-I/II [159, 160], to name a few.  
The contribution of open-source databases for Uyghur, Kazakh, and Kyrgyz ASR research is even clearer. Especially, we can see that, before the appearance of open-source data, such as THUYG20, KSC, and Common Voice, research on these three languages largely was mostly technique migration from the common languages. However, after the appearance of open-source data, much innovative work emerged. This is the most obvious for the research progress on Kyrgyz. Kyrgyz ASR research started in 2018, much later than the studies on Uyghur. However, due to the Common Voice database, the recognition accuracy has rapidly increased within three years, and Kyrgyz has become one main language for some cutting-edge technologies such as completely unsupervised learning.  
The above observations demonstrate that open-source data are perhaps the first and crucial step to promote the technical development of a new low-resource language.
# Design and Analysis of High-Capacity MIMO System in Line-of-Sight Communication
## 3 Analysis of Antenna Configuration
### Rectangular 3 \(\times\) 3 Transceiver Antenna Array  
A 3 \(\times\) 3 rectangular transceiver antenna array has a similar calculation method to the 2 \(\times\) 2 ones. The rectangular transceiver antenna array is shown in Figure 6.  
In Figure 6, \(d_{s}\) is the array element spacing, \(d\) shows the distance of the transceiver antennas, and \(d_{11},\ d_{12},\ d_{21},\ \text{and}\ d_{22}\) are the sub-channel propagation paths.  
According to the knowledge of geometry, the transmission distance can be written as:  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Signal Frequency \(f\) (GHz)** & **Distance \(r\)** & \(k_{0}\) & \(k_{1}\) & \(k_{2}\) & \(\theta\) **(rad)** \\ \hline \multirow{3}{*}{2.6} & 10 & 0 & 0 & 1 & 0.0879 \\  & 100 & 0 & 0 & 1 & 0.0277 \\  & 300 & 0 & 0 & 1 & 0.0160 \\ \hline \multirow{3}{*}{3.5} & 10 & 0 & 0 & 1 & 0.0757 \\  & 100 & 0 & 0 & 1 & 0.0239 \\  & 300 & 0 & 0 & 1 & 0.0138 \\ \hline \multirow{3}{*}{5.6} & 10 & 0 & 0 & 1 & 0.0598 \\  & 100 & 0 & 0 & 1 & 0.0189 \\  & 300 & 0 & 0 & 1 & 0.0109 \\ \hline \multirow{3}{*}{28} & 10 & 0 & 0 & 1 & 0.0267 \\  & 100 & 0 & 0 & 1 & 0.0085 \\ \cline{1-1}  & 300 & 0 & 0 & 1 & 0.0049 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Solution of the system equations.  
Figure 6: Rectangular 3 \(\times\) 3 transceiver antenna array.  
\[\left\{\begin{array}{c}d_{11}=d_{22}=d_{33}=d\\ d_{21}=d_{12}=d_{32}=d_{23}=\sqrt{d_{s}^{2}+d^{2}}\\ d_{13}=d_{31=}\sqrt{4d_{s}^{2}+d^{2}}\end{array}\right. \tag{43}\]  
According to Equations (19), (23), and (43), the expression of channel matrix can be written as:  
\[\mathbf{H}_{3\times 3}=\left(\begin{array}{cccc}e^{2\pi m\pi m}&e^{2\pi n\sqrt{1+m ^{2}}}&e^{2\pi n\sqrt{4+m^{2}}}\\ e^{j2\pi n\sqrt{1+m^{2}}}&e^{2\pi m\pi}&e^{2\pi n\sqrt{1+m^{2}}}\\ e^{j2\pi n\sqrt{4+m^{2}}}&e^{2\pi n\sqrt{1+m^{2}}}&e^{j2\pi m}\end{array}\right) \tag{44}\]  
Equation (44) is a very complicated matrix, and there is no precise expression for the channel capacity of the system. However, the channel capacity depends on \(m\) and \(n\), which represent the transceiver distance \(d\) and array element spacing \(d_{s}\) respectively. Moreover, the channel matrix does not satisfy the phase condition Equation (18), and when \(m\gg n\), the channel capacity will be close to the minimum value, which can be written as:  
\[C_{min}=log_{2}(1+3\rho) \tag{45}\]  
The reason why the channel capacity will be close to the minimum value is that when \(m\) is large, the effect of \(n\) on the channel phase is negligible, which results in a small phase difference of elements in the channel matrix. However, when \(m\) is relatively small, an appropriate value of \(n\) can be selected to obtain larger channel capacity.
## 2 Materials and Methods
### Statistical Analysis  
The statistical analysis was performed using IBM-SPSS Statistics 26 software (IBM Corp., Armonk, NY, USA). Data are presented as mean, standard deviation, and percentage. A statistical power analysis (software package G*Power 3.0) before the initiation of the study indicated that a total number of 40 participants (20 participants in each group) would yield adequate power (>0.85) and a level of significance (<0.05). The numbers were increased to 25 participants per group to account for potential dropouts [42]. Normal distribution of data was assessed using the Kolmogorov-Smirnov test, and all data were found to be normally distributed. Group comparisons at baseline were performed using Student's \(t\)-test for continuous variables and the chi-square test for categorical variables. Two-way analyses of variances (2-way ANOVA) (2 groups [SS and PIR] \(\times\) 2-time points [pre and post-intervention]) with repeated measures were applied to calculate the significantly different means within and between groups. If a significant interaction of time \(\times\) group was observed, paired \(t\)-tests were used to examine within-group changes, and independent \(t\)-tests were conducted to compare between-group differences between the SS and PIR groups. The level of significance was set at \(p<0.05\). The Pearson test was used for correlations. Since the \(p\)-value alone is insufficient to determine the effect of the intervention, the size of the change in outcomes was examined using [PERSON]'s d effect sizes, with the following interpretations: 0.0-0.2 indicating a small effect, 0.5-0.7 a medium effect, and 0.8-2.0 a large effect.
# Centralized vs. Decentralized: Performance Comparison between BigchainDB and Amazon QLDB
## 7 Discussion and Conclusions
### Summary, Limitations and Conclusions  
The present paper is intended for both industrial and research readers. Given the variety of databases that can be used to develop an LT-based solution to a specific problem, in practice, selecting the most appropriate database is difficult. The decision-making process in this regard is influenced by several factors, including the specific context.  
In this paper, the use of two popular databases was compared, with an analysis of the findings obtained. This benchmarking study introduced a track and trace application that allows supply chain partners to manage (and securely exchange) information needed to ensure traceability using decentralized and centralized ledgers.  
The analysis of the results of the experiments presented in this paper can be helpful to practitioners in making the best decision on the use of a specific database for the development of a specific LT-based application. Researchers can also use the analysis presented in this material to select the database that would be best suited for experiments, such as testing and validating certain theories.  
However, this paper has some limitations that will be addressed in future research, the most significant of which is the limited number of experiments and operations performed. QLDB is provided as a service (SaaS) for the organizations accessing it (an advantage for compliance with the local legislative framework), with centralized functioning. BigchainDB allows another approach, which is more convenient in some cases, for example, self-hosting (with assurance of data ownership, but also in-house assurance of legal compliance) with distributed traceability via nodes retaining the distributed records.  
Figure 33: CPU and memory usage—maximum values.  
Finally, the experiment presents only two of the currently available options. With the growing interest in blockchain technologies and their applications in traceability, new platforms that match the features of the two described platforms are emerging.  
Although the results of the experiments with QLDB have shown a better performance for certain criteria, depending on the context and the specific requirements of the applications to be developed, many users will undoubtedly find BigchainDB appealing as well.
# Optimal Configuration and Path Planning for UAV Swarms Using a Novel Localization Approach
## 5 Simulation Results
### Combination of Angle Rule and Distance Rule  
The optimal paths considering the noise variance change with distance and all constraints are included in the optimization problem. The simulation results are shown in Figure 5.  
According to Figure 5a,b, the distance between each UAV and the emitter in the initial stage is nearly the same in the initial time step, so it is similar to the angle rule case: Each UAV tends to expand the detection angles to have a better view of the emitter. The initial flight direction of UAV3 is basically the same as the path in Section 5.1. After about the 10 th time step, UAV3 begins to make  
Figure 5: (a) Optimal paths with constraints. (b) Evolution of angle changes. (c) Comparison of localization performance: optimal deployment and fixed deployment.  
a turn and fly toward the emitter, which is mainly caused by the distance rule. The flight path of UAV2 and UAV4 is mainly affected by the angle rule during the first several steps and they fly away from the UAV1. When large angles are obtained, they start to be affected by the distance rule and fly towards the emitter so that a balance between the angle rule and distance rule is eventually reached. UAV1 flies towards the emitter and starts to rotate around the emitter since it is affected by a lower limit \(R_{I}\) of distance at about \(t=63\ s\). Figure 5c shows a comparison of the optimal UAV paths and straight-line paths. The RMSE of UAVs flying with straight-line trajectories generally tends to decrease, mainly because of the distance rule. However, its location accuracy is still unstable as the relative deployment of UAVs and the emitter at certain moments are rather inappropriate for the emitter localization. Similar to the angle rule case, the localization performance using path optimization is much better than the straight-line paths. If there is a requirement to the lower RMSE, UAVs will rotate around the estimated emitter location in a fixed distance according to the angle rule.
###### Abstract  
The language inclusion checking of timed automata is described as the following: given two timed automata \(M\) and \(N\), where \(M\) is a system model and \(N\) is a specification model (which represents the properties that the system needs to satisfy), check whether the language of \(M\) is included in the language of \(N\). The language inclusion checking of timed automata can detect whether a system model satisfies a given property under the time constraints. There exist excellent studies on verifying real-time systems using timed automata. However, there is no thorough method of timed automata language inclusion checking for real-life systems. Therefore, this paper proposes a language inclusion checking method of timed automata based on the property patterns. On the one hand, we summarize commonly used property patterns described by timed automata, which can guide people to model the properties with time constraints. On the other hand, the system model \(M\) often contains a large number of events, but in general, the property \(N\) only needs to pay attention to the sequences and time limits of a few events. Therefore, the timed automata language inclusion checking algorithm is improved so that only the concerned events are required. Our method is applied to a water disposal system and it is also evaluated using benchmark systems. The determinization problem of timed automata is undecidable, which may lead to an infinite state space. However, our method is still practical because the properties established according to property patterns are often deterministic.  
timed automata; language inclusion; property pattern; verification
###### Abstract  
Location-based services (LBS), as one of the most popular location-awareness applications, has been further developed to achieve low-latency with the assistance of fog computing. However, privacy issues remain a research challenge in the context of fog computing. Therefore, in this paper, we present a fine-grained and privacy-preserving query scheme for fog computing-enhanced location-based services, hereafter referred to as FGPQ. In particular, mobile users can obtain the fine-grained searching result satisfying not only the given spatial range but also the searching content. Detailed privacy analysis shows that our proposed scheme indeed achieves the privacy preservation for the LBS provider and mobile users. In addition, extensive performance analyses and experiments demonstrate that the FGPQ scheme can significantly reduce computational and communication overheads and ensure the low-latency, which outperforms existing state-of-the art schemes. Hence, our proposed scheme is more suitable for real-time LBS searching.  
location-based services (LBS); fog computing; low-latency; fine-grained; privacy-preserving
# Dimensionless Energy Conversion Characteristics of an Air-Powered Hydraulic Vehicle
## 1 Introduction  
In recent years, to reducing emissions, new energy vehicles has been widely promoted. As a kind of new energy vehicle, air-powered vehicle has some advantages, such as simple structure, lightweight, explosion prevention, no pollution emissions, and so on. Hence, it has important potentials in mines, chemical plants and airports, as well as having attracted more and more engineers' attention [1; 2; 3; 4].  
In 2013, [PERSON] et al. proposed an air-oil converter using an equal-area cylinder [5]. The converter was driven by the compressed air. In this article, the system efficiency was shown to be nearly 50% at 200 rpm according to the calculations and experimental study. However, because of the areas of air cylinder and the oil cylinder are equal, so the pressure of the compressed air must be higher than the output oil pressure, so the residual air pressure may lead to a lower efficiency. Researchers of Yijuan Zang in the same year has identified a new pressurizing system which can achieve a high pressure output with the use of a new type bidirectional Pneumatic-hydraulic converter. Because of the saving of the hydraulic station, it can save the space and can reduce the energy consumption. However, one of the key issues in this study is that the two hydraulic chamber may have an effect on the efficiency [6]. So in 2016, [PERSON], [PERSON] et al. proposed an expansion energy used Hydropneumatic transformer (short for EEUHP transformer). Compared with before, it has a compact size and excellent flexibility, and can improve the system efficiency using the expansion energy of the compressed air. However, one regret is the demand of electricity, so the safety performance need improvement [7].  
In this study, firstly, the working principle of the HP transformer has been analyzed. In addition, according to the analysis, power system of the air-powered vehicle used HP transformer has beenpresented. Furthermore, the mathematic model of the HP transformer was built. By selecting the appropriate parameter values, a dimensionless model was set up. To confirm the dimensionless mathematic model, an archetype was built and studied. Moreover, the output characteristics of the HP transformer can be studied through simulation study. Finally, the influence of the key parameters was showed to get the most suitable value.
# Wastewater Treatment with Bacterial Representatives of the _Thiothrix_ Morphotype
## 2 Types of Wastewater Treatment Plants Where _Thiothrix_ Morphotype Can Occur
### Latest Inventions for Membrane Reactors  
It should be especially noted that, for organic pollutant removal, which is difficult when using traditional biodegradation methods, chemical methods with the application of strong oxidizing agents, such as peroxymonosulfate, hydrogen peroxide, etc., have long been used as an alternative. To enhance the action of oxidizing agents, catalysts based on perovskite oxides are used. However, with the growth of industry in recent years, the insufficiency of this variant of the method has been noted, which has stimulated a search for new solutions to improve the efficiency of wastewater treatment.  
For this purpose, the latest layered perovskite oxides of the Ruddlesden-Popper structure have recently been synthesized and shown to serve as an effective next-generation catalyst for the activation of peroxymonosulfate, an oxidant used in the oxidative removal of organic pollutants in modern wastewater treatment plants. Unlike conventional perovskites, in Ruddlesden-Popper perovskites, the catalytic role in the decomposition of the pollutant chemical compound is played not by free radical forms of oxygen but by non-free singlet oxygen radicals. For this reason, the newest Ruddlesden-Popper perovskite oxides have demonstrated exceptional efficiency in phenol removal (complete removal from wastewater in 10 min) [66].  
The development of new Ruddlesden-Popper perovskite oxides in 2023 showed that they can serve as an effective catalytic component in next-generation composite membranes, increasing the speed and safety of the organic wastewater treatment process. In contrast to conventional perovskite oxides with the formula ABO\({}_{3}\), the Ruddlesden-Popper perovskite oxides of the A\({}_{2}\)BO\({}_{4}\) type have improved catalytic properties.  
In search of materials with optimal properties, [PERSON] et al. [67] synthesized a La\({}_{2}\)CoO\({}_{4}\)-\(\delta\) catalyst with a Ruddlesden-Popper structure, in one of the best variants of which the A-site was 50% replaced by strontium to obtain the LaSrCoO\({}_{4}\)-\(\delta\) structure. The use of such a catalyst allowed the complete oxidative decomposition of tetracycline hypochloride in 14 min. The obtained compound embedded in the matrix of a polyacrylonitrile ultrafiltration membrane gave a composite material of extraordinary efficiency in wastewater treatment, the use of which resulted in the 94% degradation of tetracycline hypochloride in only 3 min and a significant reduction in the wastewater's toxicity.
## 3 The Materials and Methods
### Perturbed Multi-Branch Variational Module
Each branch's core is a residual structure instantiated with depthwise separable convolutions. These convolutions reduce the number of parameters significantly while still retaining the network's ability to meaningfully extract features. For stochastic control during training, Monte Carlo Dropout (MC-Dropout) is employed at both spatial and channel levels, effectively mimicking a variety of realizations of the network and increasing robustness to input alterations. The last step of every branch consists of a Bayesian fully connected layer, which is known to be trained by the Bayesian Backprop approach. This method trains models by optimizing the variational parameters while minimizing ELBO, thus encouraging the learned weight distributions to remain, in a sense, close to the prior and not too strongly data-dependent. Each branch contributes to a diverse but consistent ensemble of predictions, with this design enabling HUE-Net to not only make precise identity inferences but also confidently quantify prediction confidence:  
\[L_{ELBO}=E_{q_{\phi(\omega)}}[log\ p(y|x,\omega)]-KL\big{(}q_{\phi}(\omega) \big{|}\big{|}p(\omega)\big{)} \tag{11}\]  
In this variational framework, \(p(\omega)\) represents the prior distribution over model parameters, typically assumed to be standard normal. The Kullback-Leibler (_KL_) divergence serves to regularize the learned variational distribution to avoid excessive divergence from the prior. For inference, HUE-Net performs several stochastic forward passes over the variational branches to produce a set of sampled embeddings. These embeddings are averaged to form a robust identity representation, while the variability around this average, captured by the standard deviation of angular distances between the embeddings and class centroids, serves as an empirical measure of prediction confidence. The ability to estimate uncertainty provides several important benefits. First, it enables decision-making based on confidence levels, allowing the system to withhold low-confidence predictions or manually labeled sensitive ones for sensitive contexts. Second, it grants robustness by enabling the detection of adversarial or outlier inputs where unusually high uncertainty could indicate occlusion, spoofing, or unknown identities. Lastly, during training, uncertainty estimates can be used to inform curriculum learning approaches where samples with higher uncertainty are used to enhance model generalization for challenging inputs.
# A Wideband Terahertz Transmissive Polarization Manipulator Based on Metasurfaces
###### Abstract  
Wideband and multifunction operation for THz polarization manipulating devices has been desired for a wide range of applications. In this paper, a novel wideband transmissive type polarization manipulator based on metasurfaces is proposed in the THz region. The designed metasurface acts as a multifunctional polarization manipulator, performing linear to circular polarization conversion (LCPC) for relative bandwidth 43.9% (0.94 THz to 1.47 THz) for incident x/y polarizations and a wideband bandpass filter with relative bandwidth 67% (0.713 THz to 1.4346 THz) for incident slant (xy) polarizations. Wideband LCPC operation is achieved using a unique diagonal symmetric structure based on a bilayered metasurface. In order to confirm the validation of proposed results, electromagnetic simulation was carried out in two industry-standard software packages, HFSS and CST, using frequency domain and time domain solvers, respectively. Close agreement between numerical results depicts the validity and reliability of the proposed design. Polarized wave trajectory, equivalent microscopic circuit, physical mechanisms, and impact of different geometrical parameters on the performance is investigated. To the best of our knowledge, this is the first polarization manipulator based on bilayered metasurfaces. The same structure can be used as for LCPC and the transmit reject filter for THz wireless communication, including THz satellite communications, the future of communication. Moreover, they can be used in THz imaging and biomolecular control devices.  
Keywords:linear to circular polarization conversion; polarization manipulation; terahertz; receive filter +
Footnote †: journal: Electronics Letters