esa-sceva/satcom-chunk-collection huggingface dataset:
# A Novel Error Correction Approach to Improve Standard Point Positioning of Integrated BDS/GPS
## 4 Experimental Analysis
### Error Prediction Results
#### 4.3.2 Dynamic Prediction Results  
The error prediction based on LSTM was also performed on dynamic experimental data. The prediction result is presented in Figure 12 and prediction errors are shown in Table 4. As in the static prediction, the error data were divided into training set and testing set, and the ratio of the training set to the testing set was 2:1. Compared with the prediction errors of the static prediction, the effect of dynamic prediction on the Y-axis and Z-axis is better than the two static methods, while, on the X-axis, its effect is better than the static prediction of WLS method but slightly worse than the static prediction of Kalman filter on the testing set.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**RMSE of Training (m)**} & \multicolumn{3}{c}{**RMSE of Testing (m)**} & \multicolumn{3}{c}{**Correlation Coefficient**} \\ \cline{2-10}
**Axis** & **X** & **Y** & **Z** & **X** & **Y** & **Z** & **X** & **Y** & **Z** \\ \hline Positioning Error & 0.27 & 0.22 & 0.23 & 0.34 & 0.21 & 0.22 & 0.9072 & 0.9097 & 0.9396 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Prediction errors and correlation coefficient of dynamic experimental data.  
Figure 10: Result of LSTM error prediction performed on the weighted least square method: (**a**) result on X-axis; (**b**) result on Y-axis; and (**c**) result on Z-axis.
# A Review of Recent Advancements in Knock Detection in Spark Ignition Engines
## 3 Advancements in Knock Detection
### Vibration Signals
#### 3.2.1 Acquisition of Vibration Signals  
Since vibration sensors are used throughout the industry, and knock sensors are not exposed to the extreme conditions of the combustion chamber, the automotive sector is able to generally leverage advances in accelerometers used from other industries to achieve higher frequency responses and faster response times. These technologies are widely available and have been used in many of the studies identified throughout this paper. However, for widespread usage, the cost of high-precision accelerometers is somewhat prohibitive when compared to the vibration-based knock sensors that are used in every production gasoline automobile.  
Regardless, work is underway to further decrease the cost of vibration-based knock sensors. This is key, since as engine powertrains are becoming hybridized and more expensive, it is necessary to reduce the cost and complexity of the more conventional components. [PERSON] [31] presented a preliminary concept of utilizing piezoelectric accelerometers for detecting engine knocking. While it is common for most knock sensors to require external amplification, [PERSON] [31] presented a sensor with a strong enough signal that it did not require signal amplifications, hence reducing the cost of the sensor. Initial tests without external amplification devices showed promise, and future research aims to explore the full potential of these cost-effective sensors for precise measurements of the knock combustion phenomenon in prototype internal combustion engines.  
Figure 5: Summary of current and new advances in signal acquisition and processing of vibration data for the detection of knock.
# Vibration and Reliability Analysis of Non-Uniform Composite Beam under Random Load
## 3 Numerical Studies, Results and Discussion
### Influences of Different Ranges of Base Motion Excitation Angular Frequency on Vibration Responses
Influences of Mean and Variance of Base Motion Excitation Amplitude on Vibration Responses and Reliability  
The same as base motion excitation frequency, the influences of different base motion excitation amplitudes on vibration responses and reliability were studied in this section. The value ranges of frequency and amplitude of acceleration of base motion are \(\varphi\sim N\big{(}200,(200/15)^{2}\big{)}\) rad/s and \(0\leq A_{a}\leq 100\) m/s\({}^{2}  
As can be seen from Figure 4, when the frequency and amplitude of acceleration of base motion accord with Gaussian distribution, the greater the mean and variance of the base motion excitation amplitude, the greater the value of the maximum amplitude and strain and lower reliability of beam are induced. With a larger mean value of the excitation amplitude, the upper and lower limits of the interval become larger and the reliability hence becomes smaller. The excitation with larger variance but the same mean value leads to a higher possibility of large strain happening on the tested structure. When the safe and failure data points appear in the same number, the failure probability will hence increase, and the reliability will decrease. The range and magnitude of vibration response of non-uniform composite beam structure can be controlled and adjusted by changing the mean and variance of excitation amplitude of the random load.
###### Abstract  
Measurement data cleaning is a key step of edge computing in a distribution network; it is beneficial to improve the state perception and regional autonomy level of a distribution network. According to the temporal and spatial correlation of measurement data in the distribution network, a joint cleaning method of measurement data in a distribution network is proposed based on the correntropy criterion with variable center unscented Kalman filter (CC-VC-UKF). Initially, the mean square error (MSE) in the original unscented Kalman filter (UKF) is replaced by the correntropy criterion with variable center (CC-VC) to improve the accuracy of filtering the measurement data in the distribution network with a non-Gaussian non-zero mean measurement deviation. Then, the measured data of different measuring devices located on the same section of the line are filtered based on the CC-VC-UKF algorithm according to their respective reference time series to improve the signal-to-noise ratio of the measured data. Then, the filtered measured data are filtered and cleaned based on the CC-VC-UKF algorithm according to the space-time joint filtering and cleaning technology. Finally, the method is used to test the measurement data of the distribution network obtained by a power supply company in a city in north China to solve the problem of measurement deviation caused by the existence of space distance. Results show that this method can obtain FTU measurement data with higher precision from network topology based on the filtered TTU measurement data through the media of filtered spatial measurement deviation.  
data cleaning; CC-VC; spatiotemporal union; spatial measurement deviation; Kalman algorithm +
Footnote †: journal: Applied Sciences
# End-of-Life Scenarios for Mass Timber: Assumptions, Limitations and Potentials--A Literature Review
###### Abstract  
This paper presents a literature review exploring the end-of-life (EoL) scenarios for mass timber, focusing on Life Cycle Assessment (LCA), Environmental Product Declarations (EPDs), and circular principles. Despite its claimed environmental benefits, significant gaps exist in standardising LCA methodologies, including inconsistent system boundaries, challenges with time-dependent emissions, and limited integration of circular strategies. The literature review evaluates four primary EoL scenarios: reuse, recycling, energy recovery, and landfill. Reuse is identified as the most sustainable option, extending material lifespans and minimising environmental impacts, followed by recycling. Energy recovery is considered a fallback, while landfill remains the least desirable. Design for Disassembly and Reuse (DfD&R) is highlighted as critical for promoting circularity, though economic, market, and regulatory barriers hinder widespread adoption. The conclusion of this literature review calls for several thematic topics including harmonised LCA practices, policy reforms, and industry awareness to optimise EoL strategies for mass timber. By addressing these challenges, the building sector can better align with circular economy goals, reducing environmental burdens and supporting global climate targets.  
Keywords:mass timber; end-of-life stage; Life Cycle Assessment (LCA); Global Warming Potential (GWP); reuse; recycle; recovery; landfill; Environmental Product Declaration (EPD) +
Footnote †: journal: Applied sciences
## 2 Data Quality Parameters and Related Work in OSM
### Attribute Accuracy  
Attribute accuracy describes the quality of quantitative attributes and the correctness of non-quantitative attributes [71]. The quantitative (or numeric) data can easily be compared, whereas qualitative (or text) data are more difficult to handle. The established metrics can be used to measure quantitative data. The non-quantitative attributes are not always rightly spelled or have abbreviations, especially in the OSM dataset, as contributors do not follow naming conventions. For measuring the similarity or lexicographical error between data, the text similarity approach is used. The results obtained for attribute accuracy are presented as the percentage correctness of numerical or text-based values associated with an attribute [34; 46].  
Various algorithms exist for text comparison, such as 'Soundex' and 'Metaphone'. However, these need to be customized for different languages. The 'Levenshtein' algorithm [72] measures the similarity between two strings by calculating the least number of edits that is needed to modify one string to another [46; 49; 51; 55; 71]; whereas,'similar_text' function is a much simpler and faster one, which returns the number of similar characters between the two strings [73]. [PERSON] et al. [74] have assessed the attributes and quantitative information of data. A kappa index method [75; 76] has been used to assess the quantitative attribute assessment based on the classification of classes in land use cover [57; 62].
# On Noise Modeling of Capacitive Feedback Transimpedance Amplifiers in CMOS
## 1 Introduction
In terms of the models needed for TIA characterization, one typically ends with the requirement to have two elaborated models: the complete transimpedance gain model and the input-referred noise current spectral density model. Although a detailed model for the transimpedance gain for the capacitive feedback TIA had been proposed by us before (see [22] for further details), an equivalent and accurate model of the noise current was still missing. Even though, together with the gain models, the corresponding noise models were originally proposed by [PERSON] [24] and [PERSON] [5], those models, as we will see below, are very rough and ignore numerous effects which arise while designing realistic TIAs under the constraints of advanced CMOS processes. Furthermore, we believe that it is also important to develop such a noise model incrementally from the basic principles (in this case, independently considering all relevant noise sources) similarly as we performed for the gain model in [22] so that both gain and noise models are consistent with each other and are formulated following similar assumptions. As a detailed and accurate noise model for capacitive feedback TIA seems to be missing in the literature, in this work we want to close this gap by proposing an accurate noise current model which complements our previous work on the gain model reported in [22]. With this, we ensure that all important signal components in both models are considered and evaluated in a consistent manner. This will also support our understanding of the interplay of the noise sources in practical design and form a solid foundation for the efforts toward a possible noise minimization strategy. Although the modeling will be demonstrated using a single-ended design in accordance with the gain model developed in [22], the obtained results can be easily extended for differential TIA configurations. The rest of the paper is structured as follows. In Section 2, based on our previously published gain model, we propose a new input-referred noise current model for the suggested capacitive feedback TIA. In Section 3, the simulation results are presented, where we analyze the suggested noise models against the results of the post-layout simulation using programmable-gain TIA implemented for OTDR applications in 0.18 \(\upmu\)m CMOS and 0.25 \(\upmu\)m BiCMOS technologies. In Section 4, we discuss the proposed noise model, compare it to the models known in the literature, and suggest further noise improvement using a cascode current source in the source-follower block. Section 5 concludes this contribution with a summary of the obtained results.
## 3 Deepfake Technologies and the Emergence of Deepfake-Driven Social Engineering
### Relevance to Corporate Environments  
The convergence of deepfakes and social engineering presents unique risks to corporate organizations [7]. Executives and employees often use and rely on virtual meetings, emails, and instant messaging for daily operations. A single convincing deepfake message can override the standard security protocols and lead to the following:  
* **Unauthorized transactions:** Impersonated instructions for wire transfers or critical financial approval;
* **Reputational damage:** Falsified statements or controversies involving senior leadership, quickly spreading across social media;
* **Operational disruption:** Fake directives that disrupt supply chains, vendor relations, or production cycles.  
Throughout this paper, we focus on these corporate vulnerabilities while proposing methods to safeguard assets against deepfake-driven social engineering threats. By _defining_ these core concepts, we aim to establish a clear framework for understanding the subsequent sections on the threats, detection techniques, and defensive strategies in the corporate landscape.
## 5 Conclusions  
The effects of AMF content, aluminum sulfate, and PPF on MSC performance, including the slump, compressive strength and permeability, were studied. The main conclusions were as follows:  
1. With an increase of AMF content, the compressive strength of MSC first increased and then decreased. The permeability coefficients of water and chloride first decreased and then increased. They all achieved the best performance when the content of AMF was 10 wt% in the machine-made sand. AMF was found to be able to effectively reduce the pores in the range of 20-1000 nm in the MSC.
2. With an increase in the content of aluminum sulfate, the permeability coefficients of water and chloride decreased first and then increased. When the content of aluminum sulfate was 1%, the two permeability coefficients reached the minimum value. At the same time, MSC had the highest compressive strength. The aluminate sulfate was found to be able to decrease the pores in the range \(>\)1000 nm in the MSC.
3. The water and chloride permeability coefficients firstly decreased and then increased with an increase in PPF content. When the PPF content was 0.6 kg/m\({}^{3}\), the MSC reached the optimum performance with only a slight decrease in the slump of fresh concrete, the highest compressive strength (increase by more than 20% compared with no PPF), and the lowest water and chloride permeability coefficients (decrease by more than 45% compared with no PPF).
4. The optimum content of AMF contributed to a good filling effect and modify the pore structure of MSC, thereby increasing the compressive strength and impermeability of MSC. Aluminum sulfate could promote the formation of ettringe. The filling effect of ettringe in the pores made the MSC structure denser, and the porosity of MSC was reduced. PPF (0.6 kg/m\({}^{3}\)) was found to effectively decrease the pores with a size 30-3000 nm in MSC, and thus increase the impermeability.  
Conceptualization, [PERSON] and Y.W.; methodology, [PERSON] and Y.W.; formal analysis, J.W. and Y.W.; investigation, H.H.; data curation, H.H.; writing--original draft preparation, [PERSON] and J.W.; writing--review and editing, [PERSON] and H.H.; supervision, J.W.; project administration, [PERSON] and Y.W.; funding acquisition, Y.W.  
This research was funded by National Natural Science Foundation of China (51678220), the Program for Innovation Scientists and Technicians' Troyo Construction Projects of Henan Province in China (CYTD2017088) and the Program for Innovative Research Team (in Science and Technology) (19 IRTSTHN027) in Henan Polytechnic University are appreciated.  
The authors appreciate the support from the Engineering division in New York University Abu Dhabi, UAE.  
The authors declare no conflict of interest.
# Path Planning under Force Control in Robotic Polishing of the Complex Curved Surfaces
## 2 The Proposed Method
### Tool Path Planning
#### 2.2.3 Tool Path Stitching  
The final step is to link all the part surfaces to achieve the shortest possible route, minimum joint angles, and jerk-free movement. Previously [9], the shortest possible connecting route was achieved by using brute force search, nearest neighboring algorithm (NNA), and the greedy algorithm. These algorithms do not satisfy the target of achieving the smooth robot movement with minimum joint angles because they just focus to find the shortest connecting distance. Therefore, a new approach was used here, which satisfies all the mentioned objectives.  
The proposed strategy avoids the hasty orientation shifts during the connecting path movement. It sorts part surfaces in different groups based on the orientation of the \(\{T\}\) at the starting point in each part surface. Following the surface division previously as in Figure 9, there are two face groups (top and side). The total 18 part surfaces of the eyeglass frame are mainly sorted into top and side face groups. Similarly, the top face group is further sorted into the X-axis and Y-axis categories. Later, the part surfaces in the X-axis group are linked based on minimum Euclidian distance \(d(p,q)\) as express in Equation (10). The same action is performed on the other two sorted groups. Finally, all these three groups are connected to create one complete path based on the short distance covered.  
\[d(p,\ q)=min\sqrt{\left(p_{1}-q_{1}\right)^{2}+\left(p_{2}-q_{2}\right)^{2}+ \left(p_{3}-q_{3}\right)^{2}}. \tag{10}\]  
Figure 13 compares the effect of using the NNA and proposed approach to connect the part surfaces by showing the complete joints angle movement (\(\theta_{n}\): \(n=6\)) of the robot during the polishing of the eyeglass frame. Both methods utilized only an average of 32% of whole angles range available for the used robot because of the smart part division approach. However, the new proposed strategy allows the robot to maintain \(\{T\}\) orientation normal to the surface during polishing by using very less joints movements. Additionally, it provides smooth robot movement because it avoids a jerk, which occurs due to the sudden tool orientation shift while moving from one part to another part surface and hence, allows the robot to move comparatively faster. Moreover, the Joint 4 (wrist) demonstrated a minimum and smooth angle transition that was significant in avoiding the mostly occurred wrist singularity.  
Figure 12: Toolpath of the four part surfaces of the eyeglass frame.
## 2 Materials and Methods
### Methodology
#### 2.3.2 Meteorological Drought Identification Method  
The Standardized Precipitation Index (SPI) is used to assess the degree of drought in a region and to predict the trend of future drought. The SPI takes precipitation as the only input. According to the needs of this research, the sliding window of 1-to-24 months was selected to describe the precipitation deficit at different time scales [53; 54; 55]. The processed precipitation data must also undergo fitting and normalization of the probability density function of the \(\Gamma\) distribution, which can characterize meteorological drought across various regions and time scales [51]. The SPI is calculated as follows:  
\[\hat{\alpha}=\frac{1+\sqrt{1+\frac{4}{3}\left(\ln\overline{x}-\frac{1}{n} \sum_{i=1}^{n}\ln x_{i}\right)}}{4\left(\ln\overline{x}-\frac{1}{n}\sum_{i=1 }^{n}\ln x_{i}\right)};\hat{\beta}=\frac{\overline{x}}{\hat{\alpha}} \tag{4}\]  
\[H(x)=q+(1-q)G(x) \tag{5}\]  
\[t=\sqrt{\ln\frac{1}{H(x)^{2}}};SPI=S\bigg{(}t-\frac{(c_{2}t+c_{1})t+c_{0}}{(d _{3}t+d_{2})t+d_{1}t+1.0}\bigg{)} \tag{6}\]In Equation (4), \(\overline{x}\) represents the average precipitation; \(n\) is the length of the time series; and \(\hat{\alpha}\) and \(\hat{\beta}\) are the shape parameter \(\alpha\) and scale parameter \(\beta\) of the Gamma distribution, respectively. In Equation (5), q is the probability of zero precipitation and \(G(x)\) is the cumulative distribution function of the Gamma distribution. In Equation (6), \(H(x)\) is the cumulative probability function; \(t\) is an intermediate variable; and S is the sign function, where \(S=1\) when F \(>\) 0.5 and \(S=-1\) when F \(\leq\) 0.5. \(c_{0}\), \(c_{1}\), \(c_{2}\), \(d_{1}\), \(d_{2}\), and \(d_{3}\) are constants used to adjust the transformation formula to better fit the standard normal distribution.
# Multi-Step Design Optimization for the Improvement of an Outer-Rotor Brushless Direct Current Motor
###### Abstract  
Brushless Direct Current (BLDC) motors have seen significant improvements across various electrical applications. The growing focus on motor design research highlights the BLDC motor's superior efficiency compared to traditional motors, which consume more power. BLDC motors are compact, lightweight, energy-efficient, and easy to control, making them ideal for modern applications. This study aims to enhance BLDC motor design and performance by employing the Taguchi method, Response Surface Methodology (RSM), and Finite Element Method (FEM) for multi-stage optimization. A 26-watt BLDC electric fan motor is the reference model for this study. The Taguchi method helps identify optimization points, guiding further enhancements in the second stage. The study proposes a design with improved output power, torque, and efficiency. The final design achieves a 15% higher energy efficiency than the reference model, with a 10 W increase in output power and a 0.032 Nm increase in maximum torque. The FEM analysis using JMAG software v 21.2 validates the proposed design, which shows improved configurations compared to the reference model, demonstrating the efficiency of the optimization techniques for BLDC motor design.  
outer-rotor BLDC motor; Taguchi method; response surface methodology (RSM); finite element method (FEM); magnetic flux density; torque; efficiency; output power Article