esa-sceva/satcom-chunk-collection huggingface dataset:
# Multi-Backup Beams for Instantaneous Link Recovery in mmWave Communications
## 3 System Model
### Beamforming Design at the MS
Varactor phase shifters are chosen here due to their high shifting times (in \(\upmu\)s), low power requirement, reduced loss rates, and capability to continuously adjust and control the [0, 2\(\pi\)] spatial plane using a single control voltage unit. The phase shifters are then connected to a single RF chain. Overall, this structure formulates an analog beamfomer composed of multiple radiated beams that carry the same modulated data. The benefit of using an analog beamformer here is to reduce the power consumption levels associated with the RF chains, as in the case of digital and hybrid architectures. Since a single RF chain is used at the MS, the orthogonal beam coding technique  
Figure 1: Proposed parallel analog beamformer. is adopted here. Namely, the weights of the antenna elements are modified by a unique set of codes to produce unique beams of distinguished signals. The orthogonal codes here create distinguishable spatial signatures for each beam-bundle, and thereby can identify the exact direction of the highest received signal in the bundle-beam from that particular direction. Hence, this work exploits orthogonal Hamming codewords, \(c_{m}\), i.e., \(c_{m}[e,\;\;d_{\rm H}]\), where \(e\) is the codeword length, and \(d_{\rm H}\) is the Hamming distance between successive codewords. Additionally, each codeword is scaled by the control signals, \(z\), and features \([\;\!\!\!\!\  
symbolizes the amplitude of the \(n\)-th antenna, the wave number, and the maximum radiation principal at the BS, evaluated as  
\[\varphi_{0}^{\text{BS}}=-va\sin\theta_{0}^{\text{BS}}\cos(\phi_{0}^{\text{BS}}- \phi_{n}^{\text{BS}}) \tag{6}\]
## 2 Formulation of The Problem  
### Signal Model  
The multiple source separation problem is to separate the simultaneously occurring sources from their mixtures with no (BSS) or very limited (semi-BSS) prior knowledge about the mixing process or the sources. In this paper, we focus on the latter. Considering both the size of the microphone array and the preserved spatial parameter-integrity of the original signal, a B-format microphone with four channels, i.e., Front Left Up (FLU), Front Right Down (FRD), Back Left Down (BLD), and Back Right Up (BRU), is considered.  
We suppose a scene where B-format microphone is located in the center of the room, as shown in Figure 1. There exist a certain number of speakers in the horizontal plane of the microphone with different angles relative to the center of the B-format microphone [22], i.e., point \(O\). In the discrete TF domain, the pressure signal recorded in free-field by \(ch\) channel can be written as:  
\[S_{ch}(n,I)=\sum_{i=1}^{K}H_{ch,i}(n,I)\cdot S_{i}(n,I) \tag{1}\]  
where \(S_{ch}\) represents one of the four recording signals by the B-format microphone (i.e., \(s_{FLU}\), \(s_{FRD}\), \(s_{BLD},s_{BRU}\)). \(S_{i}\) is one of the \(K\) sources with an orientation pair (\(r_{i}\), \(\mu_{i}\)), where radius \(r_{i}\) is the distance of source \(i\) with respect to \(O\), and \(\mu_{i}\) is the azimuth of source \(i\) with respect to x-axis. \(n\) and \(I\) represent the frame number and the frequency index, respectively. \(H_{ch,i}\) is the transfer function from the \(i_{th}\) source to channel \(ch\) of B-format microphone. Assuming the free-field model, the recording signals \(\bigcup\{S_{ch}\}\) can be transformed to the B-format, which consists of one omnidirectional (W) and three figure-of-eight directional (X, Y, Z) channels, i.e., \(S_{W}\), \(S_{X}\), \(S_{Y}\), \(S_{Z}\).
## 4 Discussion
### Power Shift
#### 4.2.2 Effects of Noise  
As expected, noise induces some changes indicated by the intermittent transitions to AII in Figure 9, where the tranche of AV dominates without noise, as shown in Figure 8a. At this level of noise, we can say that the power-shift method is still viable. However, because of the intermittencies to AII, it may take multiple tries to access the desired attractor. Note, AIV, AVII, and AVIII are all small domain attractors which are difficult generally to access. Preliminary tests show noise will most likely prevent any access to these three attractors. Clearly AIII, AV, and AVI have larger domains and survive small amounts of noise. AIII, which has the largest domain of AV and AVI, survives a greater noise amplitude.
## 2 Analysis and Optimization of TIF Shape
### Comparison of Simulation Polishing  
In order to explore the difference in the surface shape correction capabilities between the optimized TIF (E = \(\frac{1}{6}\)D, D = 30 mm) and the traditional TIF (E = 0 mm, D = 30 mm), based on the self-developed process calculation software, we carried out simulation machining calculations on the same surface shape error using the above two TIFs, respectively. The selected surface shape error and simulation machining results are shown in Figure 7. Meanwhile, we also analyzed the PV convergence rate and RMS convergence rate after machining with the two TIFs. For details, please refer to Table 2.  
Figure 7: Surface shape errors and simulation machining results. (**a**) Surface shape errors. (**b**) Simulation machining residuals (E = 0 mm, D = 30 mm). (**c**) Simulation machining residuals (E = \(\frac{1}{6}\)D, D = 30 mm).  
It can be seen from the machining results that compared with the TIF when E = 0 mm, D = 30 mm, the PV convergence rate of the TIF when E = \(\frac{1}{6}\)D, D = 30 mm is increased by 32.527%, and the RMS convergence rate is increased by 33.560%. The optimization effect is obvious.
## 2 Materials and Methods
### Data-Collecting Sensors Used in the Project: GNSS, Meteorrones, In Situ Sensors, Sentinel
#### 2.2.2 Meteodrones for High-Resolution Vertical Profiling  
Meteodrones were strategically deployed in agricultural regions to complement radiosonde observations and ground-based meteorological station networks, offering high-resolution vertical atmospheric profiling. The Meteorome MM-670 is equipped with high-precision sensors for temperature, relative humidity, and pressure. Wind speed and direction are computed from the attitude of the Meteorome. Meteorones can operate in wind speeds of up to 90 km/h, withstand moderate rain, and fly through fog and clouds under icing conditions thanks to their integrated de-icing system.  
The Meteorones are pre-programmed to perform a straight vertical ascent/descent at a constant climb rate of 10 m/s up to a maximum altitude of 6000 m (AMSL). A typical flight profile takes 22 min. However, custom flights are also possible. The flights are controlled by an onboard autopilot system. The flights in Italy were conducted on-site by a pilot using a mobile drone system, while the flights in France and Romania were operated remotely from Meteomatics' headquarters in St. Gallen, Switzerland, using a Meteobase. The Meteobase serves as a ground station for remote Meteorone operations, enabling the automated launch and landing of Meteorones.  
Meteodrone flights were conducted at all demonstration sites (Italy, France, and Romania), providing detailed vertical profiles of atmospheric stability, boundary layer processes, and moisture transport. The collected data were integrated into WRF simulations, ensuring a coherent assimilation strategy alongside GNSS-ZTD and in situ temperature/humidity data.
## 3 Results and Discussion
### Wake Propagation in the AITD
In the case of \(f=1.61\), the spacing of wake vortices (marked by \"s\" in Figure 5) is increased in the middle and upper regions of Section B5 compared with the other two cases. In the cases with \(f\leq 0.90\), there are only a small number of residual wake vortices in the corresponding area of Section B5, which then almost dissipate in Section B6. However, in the case of \(f=1.61\), the clear structures of wake vortices in the middle-upper area of Section B5 can still be distinguished, and a certain number of residual wake vortices remain near the shroud in Section B6. On the other hand, with the increasing \(f\), the enhanced circumferential inclination also elongates the wake vortices, which significantly reduces their width (marked by \"w\" in Figure 5). Taking the case of \(f=1.61\) as an example, the maximum width of the wake vortices is only \(60\%\) of that in the case of \(f=0.71\). Figure 6 compares the radial distribution and contours of the \(\mathrm{Cp_{0}}\) in Section B6 for the various \(f\) cases. Based on the above conclusion, the wake vortex dissipation is enhanced with the increase of \(f\) in the bottom of the passage, so the pitchwise mass-averaged \(\mathrm{Cp_{0}}\) in the area with \(\mathrm{h/H}<0.3\) in the high \(f\) cases (such as \(f=1.61\)) is lower than that in the low \(f\) cases. Comparing the corresponding regions in Figure 6b, c, and d, the area of the high \(\mathrm{Cp_{0}}\) contour decreases with the increasing \(f\). In the case of \(f=1.61\), the wake has almost been dissipated, so the corresponding region with \(\mathrm{h/H}<0.3\) becomes a uniform low \(\mathrm{Cp_{0}}\) area. In the middle-upper area, due to the delayed interaction of wake vortices and their dissipation in the high \(f\) cases, the yellow block representing low total pressure coefficient decreases with increasing \(f\), as shown in Figure 6b-d.
# Biological Production of 3-Hydroxpropionic Acid: An Update on the Current Status
## 4 Production of 3 HP from Other Sources
The first route involves the use of malonyl-CoA. In this case, phosphoenolpyruvate is transformed through pyruvate to acetyl-CoA, which is converted to malonyl-CoA by the action of acetyl-CoA carboxylase, a biotin-dependent enzyme. Finally, malonyl-CoA is converted to 3 HP by malonyl-CoA reductase [64]. This pathway was constructed in the cyanobacterium _Synechocystis_ sp. by transferring the _mcr_ gene from _C. aurantiacus_[64]. To improve the supply of NADPH and malonyl-CoA, the genes for NAD(P)-transhydrogenase (_pmtAB_) and acetyl-CoA carboxylase and biotinase (_accBCAD-birA_) were overexpressed. Finally, to improve the carbon flux towards 3 HP, the genes involved in the formation of PHA (_phaB_) and acetate (_pta_) were deleted. The newly constructed strain was capable of producing approximately 0.84 g/L 3 HP directly from CO\({}_{2}\). The malonyl-CoA route was also used by [PERSON] et al. [65] for the construction of a recombinant _Synechococcus elongatus_ strain. The authors expressed the _mcr_ gene from _Sulfolobus tokodaii_ and the malonate semialdehyde reductase gene (_msr_) from _Metallosphaera sedula_, which resulted in the production of 0.67 g/L of 3 HP. The second approach is to use the \(\beta\)-alanine intermediate pathway, where phosphoenolpyruvate is converted to oxaloacetate by the action of phosphoenolpyruvate carboxylase. Oxaloacetate is transformed by the action of aspartate transaminase to aspartate, which is then converted to \(\beta\)-alanine by the action of aspartate carboxylase. Finally, \(\beta\)-alanine is converted to malonate semialdehyde by the action of \(\beta\)-alanine aminotransferase, and finally, to 3 HP by the action of malonate semialdehyde reductase [65]. [PERSON] et al. [65] constructed this pathway in _S. elongates_ cells by expressing the phosphoenolpyruvate carboxylase gene (_ppc_) and the aspartate aminotransferase gene (_aspC_) from _E. coli_, together with the \(\beta\)-alanine aminotransferase gene (_SkPYD4_) from _Saccharomyces kluyveri_ and the _msr_ gene from _M. sedula_. Production of 3 HP from CO\({}_{2}\) was approximately 0.19 g/L, which was lower than the results obtained when 3 HP was produced through the malonyl-CoA intermediate pathway. Although the results obtained from the direct conversion of CO\({}_{2}\) to 3 HP are still low, direct conversion of CO\({}_{2}\) to high-value chemicals is a very promising process, and during the next year, more research work is expected to be devoted to this, with the aim of improving the conversion yields.
###### Abstract  
The typhoon impact on an estuarine environment is complex and systematic. A three-dimensional hydrodynamic and salinity transport model with a high-resolution, unstructured mesh and a spatially varying bottom roughness, is applied to investigate the effects of a historical typhoon, Fongwong, which affected Shanghai, on the hydrodynamics and saline water intrusion in the North Branch (NB) of the Yangtze River Estuary (YRE). The model is well validated through observation data of the tidal level, current velocity and direction, and salinity. The numerical results of this typhoon event show that: (1) the tidal level and its range increase toward the upstream part of the NB due to the combined effects of the funnel-shaped plane geometry of the NB and the typhoon; (2) the current velocity and the flow split ratio of the NB varies with the tides, with a maximum increase by 0.13 m/s and 26.61% during the flood tide and a maximum decrease by 0.12 m/s and 83.33% during the ebb tide, i.e., the typhoon enhances the flood current and weakens the ebb current; (3) the salinity value increases in the NB to a maximum of 1.40 psu and water is well-mixed in the vertical direction in the typhoon's stable and falling period. The salinity distribution gradually recovered to the normal salt wedge pattern in 3 days following the typhoon. Although this study is based on a site-specific model, the findings will provide valuable insights into saline water intrusion under typhoon events, and thus assist in implementing more efficient estuarine management strategies for drinking water safety.  
three-dimensional model; Typhoon Fongwong; salinity intrusion; vertical stratification and mixing; North Branch (NB) of the Yangtze River Estuary (YRE)
## 1 Introduction  
This manuscript presents an analysis of the altimetry performance of GEROS-ISS: a future space borne GNSS-R (Global Navigation Satellite System Reflectometry) experiment onboard the Columbus module of the International Space Station. GNSS-R is a relatively novel technique that uses navigation signals as signals of opportunity in a sort of bistatic radar. Scatterometry observations can be performed by comparing the power of the left hand circularly polarized direct signal, and the (mostly) right hand circularly polarized reflected one. Altimetry observations can be performed by comparing the differential time of arrival between the reflected and the direct signals. The precise measurement of this delay is affected by instrument errors, but by errors in the platform itself (varying orbital height and multipath), by ionospheric effects and surface scattering mechanisms. This work summarizes the results of the altimetry error budget carried out during one of the two Phase A studies of GEROS-ISS.
# Relay Selection Scheme for Multi-Hop Transmission of MU-MIMO System
## 2 System Model
### Decode-and-Forward (DF) Relaying Scheme  
The DF relaying scheme is one of the multi-hop transmission schemes. Figure 2 shows the model of the DF relaying scheme.  
Figure 1: The system model for proposed relay selection scheme.  
In the DF relaying scheme, the BS transmits the signal to be transmitted to the UEs to the relay. The relay decodes and detects the received signal from the BS. Then the relay re-modulates the signal and transmits it to the UEs. Therefore, the DF relaying scheme has a complicated signal processing in the relay, but does not amplify the noise and does not require a complex power allocation scheme. However, the DF relaying scheme has the error propagation problem because it uses the relay. Therefore, the DF relaying scheme requires the appropriate relay selection scheme to overcome the error propagation problem.
# Data Quality Analysis and Improvement: A Case Study of a Bus Transportation System
## 6 Experimental Results and Analysis
### Results of Cleaning Redundant, Conflicting, and Erroneous Data
#### 6.1.2 Results of Cleaning Conflicting Data  
In the field of bus transportation systems, the types of conflicting data are twofold: multi-source data naming conflicts and data inconsistency. The first type refers to the fact that a particular attribute is contained in different tables, but each table has a unique attribute name for that attribute. We used the rule-based approach [41] to identify the relevant data conflict issues. For example, the license plate number has three different attribute names in different tables. The corresponding attribute name in \"Bus_first\" is called \"numberPlate\", in \"Bus_second\" it is represented by \"plateNo\", and in the \"Install_register\" it is represented by \"carNum\". Data inconsistency means that the same entity is named differently in different tables. For instance, consider an entity connected to a specific bus line that requires a unique identifier. In the \"Route table\", it is marked as \"Business Line 2,\" while in the \"Install_register\" table, it is labeled as \"Business 2\". Similarly, \"Fan 186 Road\" in the \"Route\" table corresponds to \"Fan 186 Line\" in the \"Install_register\" table, and so on.  
To address the first issue, this paper uses the data standardization method described in Section 2, which takes \"numberPlate\" as the unique attribute name for the number plate in all related tables. Furthermore, to address the second issue, this paper provides a catalog of distinct representations of identical entities. By cross-referencing the descriptions of these entities across various tables, it aims to standardize the entity identifiers originating from  
Figure 4: The data quality issues, involved tables, and representative data quality problems.  
different sources, ensuring uniformity in format and content. Consequently, this approach safeguards data consistency and facilitates the creation of a conflict-free dataset.
# A Survey on Deep Learning in 3D CAD Reconstruction
## 6 CAD Representation
### Polygon Mesh  
In 3D CAD data, polygon mesh representation is a common method that can be used to represent complex 3D shapes [103]. Polygon mesh data consists of vertices (points in 3D space), edges (edges connect two vertices and represent the boundaries of geometric figures), and faces (faces are formed by a set of vertices connected in a specific order) [104]. Polygon mesh data in CAD software represents design details and complexity, with applications spanning 3D modeling, animation, and game development. The representation of polygon mesh combines geometric and topological information, and has the characteristic of being able to accurately describe complex 3D shapes.  
Compared with B-rep, polygonal meshes differ fundamentally in their data structure. B-rep approximates the surface of an object through discrete triangles or polygonal patches and is mainly used in graphics rendering and visualization, such as in games and animations [105], while B-rep uses parameterized curves and surfaces to accurately represent geometric shapes and their topological relationships. It is widely employed in engineering design and manufacturing. In contrast, B-rep is better suited for structural modeling and geometric calculations, offering higher accuracy and more robust expression capabilities.
## 2 The Algorithm
### Adaptive Consistency Filtering
#### 2.4.2 Depth Consistency Filter  
A small area of an object surface can usually be approximated by a plane. This assumes that the depth difference between point \(p\) and its neighbor points is small.  
The average depth difference between point \(p\) and all its neighbor points whose projections on the same selected image are inside a \(5\times 5\) pixel window centered at the projection of \(p\) can be computed by Equation (19)  
\[\overline{dh}=\left(\sum_{j=1}^{N2}h-h_{j}\right)/N_{2} \tag{19}\]  
where \(h\) and \(h_{j}\) are the depths of point \(p\) and its neighbor points. \(N_{2}\) is the number of its neighbor points in the \(5\times 5\) pixel-window.  
On the other hand, the depth difference between point \(p\) and a neighbor point \(p_{t}\) can be estimated as \(s\times tan\)\(\theta\), \(\theta\) being the view angle defined above. When the object surface is in parallel with the image plane, i.e., \(\theta\) = 0, the distance between \(p\) and \(p_{t}\) is roughly \(s\) (the expansion step \(s\) is approximately preset as the space resolution on the object surface related to a one pixel interval), and the depth difference between \(p\) and \(p_{t}\) is nearly zero. When the object surface inclines by an angle \(\theta\), the depth difference between \(p\) and \(p_{t}\) increases to approximately \(s\times\tan\)\(\theta\). So we can roughly set a threshold value \(th_{dh}\) for \(\overline{dh}\) by  
\[th_{dh}=\left\{\begin{array}{ll}2s\times tan\theta&30\leq\theta\leq 70\\ 1.8s&\theta<30\\ 10s&\theta>70\end{array}\right. \tag{20}\]  
where \(th_{dh}\) is simply fixed as 1.8s or 10s to avoid an extremely small or extremely large threshold when \(\theta\) < 30 or > 70. Since \(th_{dh}\) increases with \(\theta\), so the allowable depth difference between neighbor points adapts automatically to larger values at larger view angles. The depth of point \(p\) is regarded as discontinuous if the average depth difference \(\overline{dh}\) is bigger than \(th_{dh}\).  
Besides outliers, occlusion can also lead to depth discontinuity. As illustrated in Figure 4a, when observed from a camera with an optical center \(O_{1}\), the depth around point \(p\) is discontinuous due to occlusion. When observed from another camera with an optical center \(O_{2}\), the discontinuity disappears. By contrast, in the case of an outlier, the depth discontinuity will always exist, regardless of viewpoints, as illustrated in Figure 4b. To distinguish these two situations, we checked the depth discontinuity of point \(p\) in every selected image. If the depth is discontinuous in the majority of the selected images (i.e., in more than sixty percent of total selected images), the point is identified as an outlier and filtered out.
## 3 Results and Discussion
### Analytical Study
#### 3.4.4 Real Sample Analysis  
The practical application of the developed sensor was evaluated by the detection of H\({}_{2}\)O\({}_{2}\) in milk without any pretreatment. To eliminate the matrix effect, the standard addition method was used with selected GCE/MWCNT/UN-MNP sensors at optimized conditions. At first, a volume of 100 \(\upmu\)L of a prepared mixture of milk sample containing 90 \(\upmu\)L of milk +10 \(\upmu\)L of 0.1 M H\({}_{2}\)O\({}_{2}\) was added into an electrochemical cell containing 10 mL of electrolyte followed by successive threefold standard additions of 100 \(\upmu\)mol L\({}^{-1}\) of H\({}_{2}\)O\({}_{2}\) (10 \(\upmu\)L injections). The obtained amperometric results are shown in Figure 7. This measurement was repeated thrice and the obtained results are presented in Table 2. The developed sensor has good sensitivity for practical applications towards the detection of H\({}_{2}\)O\({}_{2}\). As represented, the obtained concentration was \(102.92\pm 1.92\)\(\upmu\)mol L\({}^{-1}\) while the spiked concentration was only 100 \(\upmu\)mol L\({}^{-1}\)). The fabricated sensor was able to recover H\({}_{2}\)O\({}_{2}\) successfully with a recovery rate of 102.92%, which indicates high accuracy of the developed sensor [30].