esa-sceva/satcom-chunk-collection huggingface dataset:
# Advancing Model Explainability: Visual Concept Knowledge Distillation for Concept Bottleneck Models
## 3 Methodology
### Preliminaries
#### 3.1.2 Knowledge Distillation  
This study focuses on logit-based knowledge distillation (KD) to train the three CBM types. Although feature-based KD presents another approach, it falls outside the scope of this research.  
Let us consider a classification task involving \(K\) classes and denote the logit output of a single input as \(z\in\mathbb{R}^{K}\). The class probability is computed as  
\[\hat{y}_{i}=\frac{e^{z_{i}/\tau}}{\sum_{k=1}^{K}e^{z_{k}/\tau}},\quad i=1, \ldots,K, \tag{1}\]  
where \(\hat{y}_{i}\) is the probability value for the \(i\)-th class, and we compute the softmax function with a temperature-scaling hyperparameter \(\tau\). By scaling the outputs, we aim to minimize the Kullback-Leibler (KL) divergence between the teacher's and the student's outputs:  
\[\mathcal{L}_{KL}=KL(\hat{y}^{T}||\hat{y}^{S})=\sum_{i}\hat{y}_{i}^{T}\log\frac {\hat{y}_{i}^{T}}{\hat{y}_{i}^{S}}, \tag{2}\]  
where \(\mathcal{L}_{KL}\) represents the logit-level KL loss, and \(\hat{y}_{i}^{T}\) and \(\hat{y}_{i}^{S}\) denote the probabilities for the \(i\)-th category in the teacher and student models, respectively.  
The most significant difference in applying KD to CBMs lies in how the logit distillation method is applied differently in each bottleneck model. The functions \(f\) and \(g\) are learned separately in the independent bottleneck student model. The loss \(\mathcal{L}_{KD}\) is solely used to compute \(\mathcal{L}_{C}\), representing the loss for predicting the \(j\)-th concept. Distillation from the teacher for \(\mathcal{L}_{Y}\), representing the loss for the final task output, is unnecessary as it employs the ground-truth concept \(c\). The sequential bottleneck model predicts concepts from the input \(x\) and then predicts the task from the predicted concepts. Therefore, only \(\mathcal{L}_{KD}\) needs to be calculated in \(\mathcal{L}_{Y}\). Lastly, the joint bottleneck model learns the functions \(f\) and \(g\) jointly and performs distillation separately for both \(\mathcal{L}_{C_{j}}\) and \(\mathcal{L}_{Y}\) due to the presence of weights connecting the concept bottleneck and the final output.
## 1 Introduction  
Nanofabrication with a resolution of few nanometers has now become common using electron emission [1] and thermal probes [2; 3]. Structuring of materials with nanoscale precision requires equally matching or better characterisation capabilities. Structural anisotropy of materials underpin their optical, thermal and mechanical properties, and have to be determined at the highest transverse and longitudinal resolutions [4; 5]. For example, a fibril of silk tens-of-nanometers in diameter defines its thermal properties [6]. Comparable IR absorbance spectra of silk were obtained using three different methods [7]: (_i_) a table-top Fourier transform infrared (FTIR) in transmission, (_ii_) a synchrotron-based attenuated total reflection (ATR) FTIR, and (_iii_) an atomic force microscopy (AFM) with a tip that responds to the IR absorbed light, also known as nano-IR [8]. The AFM-based nano-IR technique acquires structural information at the nanoscale, the area under the AFM tip forms a volume with a lateral cross-section of \(\sim\)20 nm. Different sensitivity of reflectance \(R\) and absorbance \(A\) to the real and imaginary parts of refractive index \(\hat{n}=n+i\kappa\) becomes important. The far-field absorbance is defined by \(\kappa\), while the near-field ATR-FTIR mode is affected by \(n\) due to the Snell's law [9; 10]. Another tip-based near-field optical charactrisation technique, scanning near-field optical microscopy (SNOM), is a popular method to map surface topography and refractive index \(\bar{n}\) decoupled from the scattered light. Typically, a p-polarised light with E-field aligned with the tip and perpendicular to the probed surface defines the strongest coupling and field enhancement. It is noteworthy, that the E-field component is absent in the paraxial geometry used for transmission measurements but present only under the most tight optical focusing conditions. SNOM allows probing of a material with E-field normal to the surface and was used in this study to test orientational sensitivity of this method to the alignment of amide bands in silk sliced along and across the fiber, the longitudinal and transverse cuts at 90\({}^{\circ}\) and 0\({}^{\circ}\) orientation angles, correspondingly.  
Here, we used scattering SNOM to probe \(n,\kappa\) and to determine spectral differences due to orientation in the absorbance at the amide bands of silk fibers. Cross-sections of silk fibers at 0\({}^{\circ}\) and 90\({}^{\circ}\) cut-orientations were prepared using ultramicrotome. Silk was chosen due to its well known spectral properties and uniaxial symmetry which can be examined from longitudinal and transverse microtome slices [6]. Sub-wavelength resolutions in hyperspectral IR mapping of absorbance and orientational properties of the absorption bands were measured from 100-nm-thick slices of silk.
# A Review of Progress and Hydrodynamic Design of Integrated Motor Pump-Jet Propulsion
## 3 IMP Bearing and Hydrodynamic Design  
### Bearings Used in IMPs  
The open structure of the integrated motor propeller requires its bearings to be able to operate in a seawater environment. If a nonaqueous lubricant is used for the bearing, a sealing device is required, which increases the difficulty, complexity, and cost of the entire system and is likely to cause water pollution. The use of water-lubricated bearings can reduce the weight and complexity of the integrated motor thruster system and better reflect the advantages of the integrated motor thruster. The suitable bearing arrangement is determined according to the application characteristics and use requirements of the device. The bearings can be arranged either on the hub or rim or in a mixed arrangement (Figure 6). To obtain a good hydrodynamic performance from the IMP propeller, the thickness of the duct and the diameter of the hub must be as small as possible, which leads to the complexity of the bearing design.  
The research work on water-lubricated bearings started earlier in countries with developed shipbuilding industries, such as the United States, Canada, Japan, Australia, and the United Kingdom. As early as the 1940s, there are records of American ships using water-lubricated bearings. After years of development, some companies have formed a series of water-lubricated bearing products suitable for various working conditions, such as the Thordon bearing series [31], the Perform bearing series [32] of the British TENMAT company, the water-lubricated bearing material of the British Countrose company [33], the American Duramax Marine Johnson Cutless water-lubricated bearing series [34], and the water-lubricated bearing series of BFGoodrich and Johnson Rubber (Figure 7). The types of bearing suitable for IMPs are covered in this section to provide a clear picture and complete explanation of the IMP system's controller (see Table 2).  
Figure 6: The location of the bearings in an IMP [10].  
Figure 7: (**a**) Thordon bearing of Thomson–Gordon, (**b**) water-lubricated bearing material of Countrose, (**c**) Foreform bearing of TENMAT, (**d**) Johnson Cutless bearing of Duramax Marine [35].
## 1 Introduction
More recently, new imaging techniques allowing the 3D analysis of bone architecture and the assessment of its OP-related variations have been adopted, such as magnetic resonance imaging (MRI) and computed tomography (CT). MRI provides important information on bone architecture at peripheral sites of body by measuring the signal associated with the water contained in the bone marrow. However, it is characterised by a low signal-to-noise ratio, due to the relative low amount of water contained in the bone, and it is associated with high instrumental costs [9]. On the contrary, CT systems allow for collecting information on bone architecture through the measurement of the attenuation of X-ray beams along different directions. Furthermore, comparing the X-ray attenuation coefficient of the bone sample with those of reference phantoms with a known content of inorganic phase, it is possible to evaluate the degree of bone mineralisation and its modification in the case of OP. However, bone trabecular microstructure cannot be revealed by clinical CT scans due to the insufficient spatial resolution (typically above 0.3 mm) [10], therefore, more advanced laboratory instruments performing ex vivo measurements on small bone biopsies are needed [11]. Over recent years, CT systems used for research purposes have experienced an evolution in terms of achievable resolution, reaching 350 nm in the most up-to-date equipment. A similar resolution can also be achieved by CT instruments equipped with a synchrotron source, thanks to the very intense and monochromatic photon flux [9]. However, this high resolution can be achieved only by means of extended scans and, consequently, of high radiation doses, which can hinder the application of micro-CT in the clinical field. Several works in the literature interestingly describe the most common equipment used for bone characterisation and bone strength prediction. Among them, it is worth mentioning the works of [PERSON] and collaborators [4; 11; 12; 13], describing the potentialities and the drawbacks of the most common instruments adopted for bone analysis both at the clinic and laboratory research level. However, in these works, the potential of the described instruments in the investigation of OP-induced variations in bone features is barely reported. To this purpose, besides a complete overview of the modifications of bone microstructure and composition due to OP occurrence, this review addresses the evolution of the most common techniques adopted for bone investigation, with a particular focus on the characteristics and potentialities of the most up-to-date CT instruments in the assessment of OP-induced variations in bone structure and material composition. A final section is dedicated to finite element method (FEM) analysis, based on bone micro-CT images, that enables the computational simulation of bone behavior under different load conditions and, consequently, represents a potential and revolutionary tool for a more precise fracture risk prediction.
# Bioinspired Kirigami Structure for Efficient Anchoring of Soft Robots via Optimization Analysis
## 3 Results and Analysis
### Stroke Length Variation in Microcontroller-Controlled Experiments
#### 3.4.2 Performance Analysis  
The results revealed significant variation in stroke-to-crawl efficiency. The St30h1s configuration achieved the highest crawling distance, recording 79 mm of forward displacement from just 150 mm of actuator motion--resulting in an efficiency of approximately 52.7%. This markedly outperformed the St30 configuration, which reached 67 mm of displacement from 210 mm of actuator extension (an efficiency of 31.0%). The lower stroke configurations, St20 and St10, exhibited reduced efficiencies of 19.2% and 17.3%, achieving crawling distances of 46 mm and 28 mm, respectively. These findings indicate that shorter  
Figure 7: Friction force profiles for triangular kirigami patterns with measured varying unit densities.  
stroke lengths, while allowing for more actuation cycles within a given time frame, result in lower overall displacement due to limited deformation amplitude and weaker surface engagement (Figure 8).  
The superior performance of St30h1s is attributed to the strategic 1-second hold time incorporated at the end of each stroke. This pause enhances the robot's interaction with the substrate by allowing the kirigami skin to fully engage and conform to the surface, thus maximizing anisotropic friction during the transition between extension and retraction. The added hold time in St30h1s appears to exploit this frictional asymmetry more effectively, yielding a stride length of 15.8 mm per cycle, compared to 9.3 mm per cycle in St30. The data demonstrate that stroke length alone does not guarantee efficient locomotion. While St30 outperformed the shorter-stroke configurations, it still required greater actuator extension than St30h1s to approach similar displacement levels. This implies that timing and mechanical behavior during each cycle--particularly features like dwell time--can have a substantial impact on propulsion efficiency. By extending contact duration during the extension phase, the crawler benefits from improved anchoring and energy transfer to the ground, leading to more effective locomotion per unit of actuator work.  
Figure 8: Crawling distance over time with voltage stroke cycles for different stroke cycle conditions. The top plot shows the crawling distance as solid lines, with corresponding actuation voltage cycles as dashed lines, over a 30-second period. The bottom insets illustrate the kirigami structure’s deformation at each stroke length.
## 4 Results and Discussion  
### Results of Single Parameter Evaluation  
#### 4.1.1 Depth of Groundwater  
A total of 1867 data points were collected for groundwater depth. The depth at which groundwater is located primarily determines the depth of the transmission medium through which pollutants migrate to the aquifer [37]. Generally, a greater groundwater depth requires more time for pollution to reach the aquifer. This results in a smaller amount of pollution entering the aquifer and weaker levels of contamination within the aquifer, with the opposite being true as well.  
The method for analyzing the zoning map of buried depths differs between mountainous and plain areas. In the plain and valley regions, water level data collected and supplementary surveys are interpolated and adjusted based on hydrogeological and river conditions. In mountainous areas, characterized by significant topographic variations and complex geological conditions, underground water depths are mainly classified according to aquifer types. The same type of water-bearing medium within an area is assigned an average value based on measured groundwater levels. Additionally, for valleys within mountainous regions where groundwater exists within loose rock formations, score values are determined by interpolating the buried depths observed in plain areas.  
Figure 2: Flowchart of groundwater vulnerability assessment.  
Once the above analysis is completed, the mountainous and plain areas are superimposed using GIS, ensuring uniform layer attributes. Gradation mapping (Figure 3a) is then assigned based on Table 2.
## 6 Channel Capacity Loss  
In this section, we discuss a quantitative analysis of the results obtained in the ultra-wideband channels studied in the previous sections by using [PERSON]'s channel capacity. For this purpose, let us define the capacity factor \(c\), independent of the roll-factor and the logarithm used in its definition, which is given by  
\[c=\frac{\ln\bigl{(}1+\mu^{2}\Gamma\bigr{)}}{\ln(1+\Gamma)} \tag{14}\]  
In Figure 12, we show \(c\) versus \(\Gamma\) (dB), calculated at the extreme values of \(\mu\), and which namely approximately \(\pm 1\) dB.  
Let us discuss only the worst case: the red curve referring to the negative values of \(\mu\) (dB). We can notice that, as the signal-to-noise ratio \(\Gamma\) (dB) increases in ideal conditions (no rain), the capacity factor increases from \(c=0.825\) at \(\Gamma=3\) dB to \(c=0.950\) at \(\Gamma=20\) dB; therefore, the capacity loss ranges from \(17.5\%\) to \(5\%\).  
In conclusion, we think that the capacity loss in the worst case is very limited and that rain, therefore, does not cause significant linear distortions in ultra-wideband channels at millimeter waves.
# A UAV Coverage Path Planning Method Based on a Diameter-Height Model for Mountainous Terrain
## 3 UAV Coverage Path Planning Method Based on the DH Model
### Coverage Path Planning Method Based on the DH Model
#### 3.2.3 The Coverage Path Connection Method with Trajectory Minimization and Obstacle Avoidance
By enlarging the radius \(R\) of the cross-section circle to the value of \(R+\delta\), an inferior arc \(\hat{A}B\) can be easily obtained from the split points located on the enlarged circle and is termed as the auxiliary circular path. Finally, the remaining two auxiliary connecting paths and the auxiliary circular path constitute the final auxiliary path with obstacle avoidance, as shown in Figure 8.  
The computational complexity of the proposed coverage path planning method based on the DH Model mainly consists of three parts. Firstly, the computational complexity of the equal-interval spiral ascent CPP path is closely related to the number of vertices defined in the path. Each vertex can be calculated in a nearly constant time complexity through formulas. Thus, the equal-interval spiral ascent CPP method has a computational  
Figure 8: Schematic diagram of local obstacle avoidance algorithm. Figure 7: Schematic diagram of connection results based on the coverage connection method with trajectory minimization. complexity of \(O(k)\), where \(k\) is the number of vertices in the spiral paths. Secondly, since the vertices defined in the equal-interval circle paths can be directly obtained from the constructed distance field of projection 2D space, the computational complexity of the equal-interval circle CPP method can be approximated as \(O(m)\), where \(m\) is the number of vertices in the circular paths. To some extent, the scale of the vertices in the spiral paths and the circle paths is related to the sampling rate. And by reducing the sampling rate, the scale of vertices can be reduced. Finally, although connecting these open paths and closed paths with the purpose of the shortest path length can be approximately classified as the TSP problem, which is an NPC problem, an approximation method based on a greedy strategy is proposed and provides a computational complexity of \(O(vlog(v))\), where \(v\) is the number of endpoints and split points.
# Forgery Detection for Anti-Counterfeiting Patterns Using Deep Single Classifier
## 4 Experimental Results and Analysis  
### Experimental Dataset  
A total of 90 anti-counterfeit code digital images are generated using the anti-counterfeit code generation system. The model of the printing device is HP Indigo 6000; forgery methods include directly duplicating and reprinting after scanning. The printer is used to print 90 genuine anti-counterfeiting codes, while 80 printed codes are used as standard samples to train the feature extractor, and the other 10 codes are used as test samples. Then, we duplicate and scan-reprint the 10 genuine codes correspondingly to obtain 20 forged anti-counterfeiting codes in total.  
In order to simulate the real scene of photo verification of mobile devices, the printed or forged anti-counterfeit code was photographed five times each with four mobile phones of different brands and models (see Table 1), including a Huawei Mate30, Xiaomi 11 Ultra, iPhone 13 Pro and Redmi K40 Pro. The central anti-counterfeit pattern part is extracted: 10 \(\times\) 4 \(\times\) 5 = 200 genuine anti-counterfeit pattern images, 200 copied anti-counterfeit pattern images and 200 scanned and reprinted anti-counterfeit pattern images are obtained. In addition, the 80 standard anti-counterfeiting pattern images are obtained through the standardized collection of 80 genuine anti-counterfeiting codes by industrial cameras. The digital image of the anti-counterfeit pattern, the standard pattern collected after printing, and the genuine and forged anti-counterfeit patterns taken with mobile phones are shown in Figures 6-9.  
It can be seen that the standard pattern is the closest to the digital pattern, while the mobile phone image is more or less blurry compared with the standard pattern. In addition, there is a visual degeneration from the genuine anti-counterfeit pattern to the forged pattern in texture.
# Enhanced Eco-Friendly Concrete Nano-Change with Eggshell Powder
## 5 Conclusions  
1. Concrete has been obtained, the performance of which is improved relative to standard concrete by modifying it with eggshell powder, for which the optimal dosage is determined. Concrete with improved characteristics has been obtained, which makes it possible to achieve an improvement in the environmental situation due to the competent rational disposal of accumulated waste in the form of eggshells.
2. The most effective was the replacement of part of the cement with eggshell powder in an amount of 10%.
3. The maximum increase in compressive strength of concrete nano-modified with eggshell powder was 9%, tensile strength in bending--11%, axial compressive strength--8%, axial tensile strength--9%, elastic modulus--4% in comparison with control samples without ESP. At the amount of ESP of 25% and 30%, a sharp drop in strength characteristics by 21-26% is observed in comparison with the strength characteristics of the control composition. The value of the modulus of elasticity decreased to 20%.
4. The most significant reductions in deformations in axial compression and tension, in comparison with the control values, ranged from 5% to 10%. The maximum values of deformations under axial compression and tension were recorded for concrete samples with the addition of ESP in the amount of 30%. Deformations under axial compression increased by 20%, and deformations under axial tension increased by 9%.
5. A study of the microstructure of composites nano-modified with eggshell powder was carried out, with an analysis of the changes occurring in such a microstructure due to nano-modification, confirming the obtained improvement in performance and the optimal dosage of ESP.  
Research prospects are seen in the continuation of the study of the phenomenon of concrete nano-modification and, first, agricultural waste of a different type with a different content of various useful elements to improve the properties of concrete and at the same time improve the state of the environment.  
The concrete obtained as a result of this work is an industrial sample. Authors plan its subsequent implementation in real production, and plan to reach several agreements with industrial partners to manufacture reinforced concrete and other reinforced products based on new improved concrete, which will be carried out by us in subsequent studies.  
Conceptualization, S.A.S., E.M.S., A.N.B. and V.V.; methodology, S.A.S., E.M.S. and D.E.; software, S.A.S., E.M.S., A.N.B. and N.B.; validation, V.V., S.A.S., E.M.S. and A.N.B.; formal analysis, V.V., S.A.S. and E.M.S.; investigation, N.B., L.R.M., S.A.S., E.M.S., A.N.B. and B.M.; resources, B.M.; data curation, S.A.S., E.M.S. and D.E.; writing--original draft preparation, S.A.S., E.M.S. and A.N.B.; writing--review and editing, S.A.S., E.M.S. and A.N.B.; visualization, S.A.S., E.M.S., A.N.B. and N.B.; supervision, L.R.M. and B.M.; project administration, L.R.M. and B.M.; funding acquisition, A.N.B. and B.M. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.