esa-sceva/satcom-chunk-collection huggingface dataset:
## 3 Identity-Based Short Digital Signature  
The concept of _Identity-Based cryptography_ (IBC) was introduced by [PERSON] [20] in 1984. It can be considered an alternative approach to public key certificates, motivated by the considerable computing overhead caused by certificate management operations (storing, checking, updating and revoking). In IBC, the public key of a user corresponds to the user's identity, which can be easily represented as a free-text string (e.g., an e-mail address, an IP address). An Identity-Based cryptosystem relies on a trusted Private Key Generator (PKG), which generates the master secret key and a set of public parameters. Subsequently, starting from the identity of a user, the PKG extracts the corresponding private key, which is then sent to the user through a private and secure communication channel. Inherent in IBC is a known issue of key-escrow, since the PKG generates all private keys of users. A solution to this problem was proposed by [PERSON] and [PERSON] [3], employing multiple PKGs. Certificateless publicly-key cryptography (CL-PKC), first proposed by [PERSON] and [PERSON] in 2003 [21], is intended to address the key-escrow problem with a similar approach. In this case, PKG and user each give a partial contribution to the generation of the public/private key pair, so the PKG would not know the entire private key of the user. With CL-PKC, public keys of users need to be made available to other participants somehow.  
The size of an Identity-Based signature (IBS) is an important factor when selecting a cryptographic system. In this paper, we adopt the IBS-1 scheme [22] which can be considered an identity-based counterpart of the well-known Boneh-Lynn-Shacham (BLS) signature scheme [23]. It relies on the advantages of elliptic curve cryptography and bilinear pairing. By using just only one \(x\)-coordinate, instead of the two coordinates required by other standard algorithm, such as the Elliptic Curve Digital Signature Algorithm (ECDSA) [24], the IBS-1 signature is about half the size of the one produced by ECDSA. In Table 1 we show a comparison between ECDSA and IBS-1 signature size considering a security level of 80 bits.
## 3 Results and Discussion
### Magnetic and Gravity Anomalies of the Study Area  
Gravity and magnetic anomalies are often used to identify geological structures; to divide faults, strata and metallogenic belts; and to comprehensively utilize the characteristics of gravity and magnetic anomalies in the study area as an important indicator for chromite exploration. Figure 7 shows the contour map of gravity and magnetic anomalies in this area. Figure 7a is a contour map of the magnetic anomaly, and it can be seen that the amplitude of the magnetic anomaly varies sharply between \(-\)1400 nT and 1300 nT, especially in the north-central area containing pure crystalline rocks and magnesite. The magnetic values of the above-mentioned ultrabasic plutons are lower than those of the rocks in the southern sequence of the Upper Triassic. The lithologic contact interface can be  
Figure 6: Location map and geological map of the study area. (**a**) Location map of the study area; (**b**) terrain map of the study area; (**c**) gravity and magnetic profile position; (**d**) geological map of the study area.  
determined by the magnetic value gradient zone. The magnetic value of the Upper Triassic strata in the southern region gradually decreases from north to south, indicating that the lithological contact surface is deeper in the south. In contrast, the granite and Tertiary Robusha conglomerate regions in the north have lower magnetic anomaly amplitudes and gentle changes.  
Figure 7b shows the anomaly of free air gravity in the study area. The area is located in a mountainous area, and gravity anomalies are heavily influenced by topography [36]. In order to eliminate the terrain fluctuation effect and regional signal interference, a wavelength filtering method is used for terrain correction and the residual separation of the source signal and background signal. Figure 7c shows the contour map of the residual gravity anomaly in this region. The red circle defines the contour of the residual gravity anomaly amplitude of 2 mGal, which corresponds to the location of the Robusha chromite deposit (the average density of chromite is 4.13 g/cm\({}^{3}\)). The huge Brahmaputra ultramafic rock mass is clearly presented by the residual gravity anomaly and magnetic anomaly. According to the geological record of deep boreholes, the high-gravity anomaly is caused by magnesite (average density 3.02 g/cm\({}^{3}\)) and pure crystalline rock (average density 2.88 g/cm\({}^{3}\)). By combining the annular features of the local high gravity anomaly with the braided positive magnetic anomaly, the ultrabasic rock area is determined.
## 5 Results and Discussion
### Analysis of Axial Turbine Impact on Engine Performance  
#### 5.4.1 Steady State Performance Comparison  
The performance results from the steady-state model between the radial and axial turbines are shown in Figure 29. Firstly, it can be observed that, with the implementation of the axial turbine, the engine has better performance at most operating conditions (Figure 29a,b), even though the compressor still spins at the same speed. This is likely due to high mass flow rates as a result of lower back pressure to the engine due to better flow expansion of flow by the turbine. However, 2000 rpm at 100% load is the only design point in which the performance is poorer than at baseline. This is likely due to the choice of scaling for the design point, as discussed in Section 4.2.4.  
Observing the BSFC results (Figure 29c), for most operating conditions, the BSFC for axial turbines compared to radial turbines mostly remains the same or if not slightly better due to improved performance. This demonstrates the benefit of the axial turbine with regards to fuel consumption, as the engine has not been recalibrated, and for most cases aside from 2000 rpm at 100% load, the power produced is always greater (Figure 29d). This shows that the turbine is capable of producing the same power as that of a radial turbine for a reduced exhaust gas mass flow rate, which in turn allows for increasing the air-to-fuel ratio during recalibration. Consequently, fuel consumption will decrease, further demonstrating the improvement of the newly designed axial turbine.  
Looking at the final graph (Figure 29e), the axial turbine provides higher efficiencies at all operating conditions of engine. However, this is not correspondingly reflected in the turbine power plot in Figure 29d. For the axial turbines, the figure does not show a significant increase in power, or in some cases, it actually shows less power (compared to radial turbines) at lower speeds and high loads (Figure 29d). This could be a result of the difference in map performance, as the axial turbine pressure ratio could be lower at this point, and therefore, even though the efficiency is higher, there is not enough power available.
## 1 Introduction
TRPL measurements on a CdTe single crystal have determined a minority-carrier lifetime of 360 ns and a high surface recombination velocity (\(>\)10\({}^{5}\) cm/s) [20]. The sophisticated experimental setup required for TRPL measurements precluded its application in this study. Thus, the present work focuses solely on the analysis of steady-state PL spectra to investigate the influence of surface roughness on the electronic properties of CdTe. Additionally, RS provides qualitative information about surface morphology. This technique involves the inelastic scattering of incident radiation (photon) with the quantized lattice vibration (phonon) of the material. The Raman signal is inherently weak because of the limited number of scattered photons available for detection (one in 10\({}^{8}\) photons undergoes Raman scattering spontaneously) [21]. However, employing resonance effects can significantly enhance signal intensity. Resonant Raman scattering (RRS) occurs when the laser excitation energy is close to or larger than the optical gap of a semiconductor. This resonance condition considerably amplifies the scattering cross-section, resulting in signal intensity up to a factor of 10\({}^{6}\) compared to non-resonant Raman emission [22]. As a result, RRS enables the observation of a wider range of vibrational modes, including overtones and multi-phonon peaks. While previous studies have examined the influence of surface roughness on semiconductors using PL and RRS [23; 24], a comprehensive understanding of this relationship in CdTe single crystals is lacking. This study investigates the correlation between surface roughness and the spectral characteristics of PL and RRS in CdTe. By analyzing peak intensity, position, and linewidth in PL spectra, we identify the influence of roughness on specific electronic states. Furthermore, we examine the sensitivity of active phonon modes in RRS spectra to surface roughness. A thorough understanding of how surface roughness affects electronic states and phonons is essential for both fundamental research and device applications, as these properties underpin the electrical and transport behavior of semiconductor devices.
###### Abstract  
The traditional sensorless control system of permanent magnet synchronous motor (PMSM) has the problems of low estimation accuracy and poor anti-interference ability. Moreover, the position estimation performance is subjected to position harmonic ripples caused by inverter nonlinearities and flux spatial harmonics. To optimize the dynamic performance of the PMSM sensorless control system, this paper proposes a sensorless control scheme that combines integral backstepping control with enhanced linear extended state observer (ELESO). The ELESO consists of two linear extended state observers (LESOs), which estimate the internal and external disturbances of the system, to improve the estimation accuracy of rotor position. Then, the integral backstepping controller processes the estimated rotor position and speed information to obtain d and q-axis voltages. The sensorless control scheme is implemented in the Matlab/Simulink and verified by experiments. The simulation and experiment show that the scheme can effectively suppress load interference and improve control accuracy.  
permanent magnet synchronous motor; sensorless control; integral backstepping control; enhanced linear extended state observer; rotor position estimation
# Effective Dereverberation with a Lower Complexity at Presence of the Noise
## 4 Experiments and Evaluation
### Analysis and Comparison of the Test Results
#### 4.3.2 Effect of the PSD Initialization  
We measured the effect of different initialization methods of the PSD on the proposed method when the input \(SNR=10\) dB and \(T_{60}=\) (400, 500, 600, 700, 800) ms at the same source positions as given in Section 4.3.1. Four initialization methods of the PSD of the desired signal, i.e., the method given in ISCLP, the proposed initialization method, the method given in [33], and the method given in [14,15], are employed in the proposed dereverberation algorithm. The effects of these methods on the performance of the algorithms are compared. In addition, the initialization of the PSD using real PSD of the desired signal is also compared. Figure 4 shows the result comparison.  
Figure 4: _Cont._  
Figure 3: Test results related to the filter order \(L\) between the proposed method (red line) and ISCLP (blue line).  
As expected, the result of using real PSD of the desired signal greatly improved the performance, which is the best among four evaluation indicators. The effect of the initialization of the ISCLP and the proposed method are far better than the initialization given in [33] and [14,15]. In terms of SIR, the effects of these four initialization methods (excluding the real PSD) are very similar.  
The effect of the initialization of the ISCLP is slightly better than the proposed method in the results of the PESQ, STOI, and SIR, but the ISCLP needs prior information such as the incident angle of the desired signal and the position of the microphones in advance. In the ISCLP, the inaccurate incident angle of the desired signal makes the block matrix in the GSC filter miss useful signal, which causes the distortion of the desired signal in the subsequent processing. The proposed method only uses the signals received by the microphones to obtain the estimation of the PSD of the desired signal, which is an adaptive approach. At the same time, the computational complexity of the initialization of the PSD in the proposed method is far lower than that of the ISCLP. From the experimental results, we can find that obtaining the PSD close to the real PSD of the desired signal is an  
Figure 4: Test results related to \(T_{60}\) on four initialization methods of the PSD of the desired signal with real PSD (green line), [14,15] (black line), proposed (red line), ISCLP (blue line), and [34] (cyan line).  
important way for effectively improving the performance of the algorithm. How to obtain the accurate PSD of the desired signal is a key issue for the dereverberation.
# Silica Mesoporous Structures: Effective Nanocarriers in Drug Delivery and Nanocatalysts
## 5 Application of Silica Mesopores in Drug Delivery
### Thermo-Responsive Drug Delivery  
As the literature has showed, the local temperatures of tumor sites are generally higher than the temperatures at non-tumor sites. Hence, designing a temperature-responsive drug carrier that only releases drugs at a temperature above 37 \({}^{\circ}\)C is a very useful method for killing tumor cells [194; 205; 206; 207]. Poly(N-isopropylacrylamide) (PNIPAM) is one of the most popular temperature-sensitive polymers. PNIPAM has a low critical solution temperature (LCST). [PERSON] et al. proposed a method centered on small-sized MSNs that has become widely used due to the ability of the MSNs to control  
Figure 19: The insulin secretion stimulating agent cAMP is encapsulated inside MSN and used for DDS release subsequent to G-Ins diffusion to regulate blood glucose levels.  
thermo_-responsive drug delivery very well [196]. In this method, PNIPAM was grown on the external surfaces of pre-synthesized MSNs. They showed that the PNIPAM-coated MSNs had no acute cytotoxicity while exhibiting good endocytosis efficiency on human breast carcinoma cells. [PERSON] et al. synthesized a new nano-carrier based on mesoporous SBA-15 containing Fe\({}_{3}\)O\({}_{4}\) nanoparticles and PNIPAM temperature-sensitive polymers inside the channels [199]. They increased the concentration of FeCl\({}_{2}\) in the solution after the formation of the micelles and added TEOS to the system to form a stock sol. During the subsequent condensation reactions in the sol-gel process, surfactants were added to serve as structure-determining agents. Finally, PNIPAM was linked in the mesoporous channels. [PERSON] et al. prepared Fe\({}_{3}\)O\({}_{4}\) NPs and a mesoporous material, then placed the Fe\({}_{3}\)O\({}_{4}\) NPs in the center of the material [200]. Only the removal of the CTAB was required for the production of the simple magnetic mesoporous material used, while the temperature-sensitive mesoporous with 3-(trimetoxyl) propylmethacrylate (MPS) was acrylateated in order to synthesize the mesoporous. Subsequently, PNIPAM polymerization was observed around the mesoporous material, generating the core-shell mesoporous structure.
## 4 Results and Discussion  
The study designed three sets of experiments, namely a (1) thermal annealing test, (2) thermal annealing with constant electric current test, and (3) thermal annealing with constant electric current and varied current density test. After the tests, the samples were closely examined, using EDS analysis for their IMC composition and SEM observation for thermal damage, IMC growth, and electromigration effects both in the anode and cathode of each test sample. Figure 7 presents SEM images and EDS analysis of the sample after fabrication; it appears that no IMCs were formed during the sample preparation process and that there was a clear interface between Cu and Sn.
## Materials and Methods
### Numerical Model  
To calculate 39 potential tsunami propagations into the eastern sea of Korea, we used the Cornell multi-grid coupled tsunami model (COMCOT) [12]. COMCOT is governed by linear/nonlinear shallow water equations that are resolved using leap-frog finite difference methods. It also incorporates the tsunami dispersion effect [13] and the Coriolis effect and uses both cartesian and spherical coordinate system [14]. This model has been used for many tsunami propagation and inundation studies [15, 16, 17], and the Korea Meteorological Administration uses COMCOT as its standard model for tsunami warning and hazard prediction. We use COMCOT to numerically calculate tsunami propagation in the eastern sea of Korea to predict tsunami occurrence and propagation based on the 39 scenarios. Figure 2 shows the numerical model domain and bathymetry used in this study. The numerical model domain covers an area of 116.9-142.9\({}^{\circ}\) E and 29.9-49.9\({}^{\circ}\) N. Our numerical modeling uses the linear shallow water equation with real bathym data from GEBCO (The General Bathymetric Chart of the Oceans) resampled to 30 arc seconds grid size. We set the simulation time to about 4 h with a one-second time step. The numerical modeling input information is listed in Table 1. This study only considered linear shallow water equations for potential tsunami propagation calculations. We did not set a nested grid because this study is focused only on offshore instrument deployment. Finally, we generated earthquake-induced tsunamis using the elastic fault model for instantaneous seafloor deformation. Based on the 1983 and 1993 tsunamis reaching the Korean coast 2 h after the earthquakes, we set the computation time at 4 h. Results from numerical modeling with tsunami scenario cases 04, 10, and 30 are illustrated in Figure 3.  
Figure 1: The location of 39 potential tsunami sources near the west coast of Japan.  
Figure 2: Numerical model domain and bathymetry used in numerical modeling.
# Federated Learning-Based Service Caching in Multi-Access Edge Computing System
## 4 Proposed Service Caching Framework
### FL-Based Service Popularity Score
#### 4.2.2 Distributed Inference Phase  
Each MEC server has a trained global model \(w_{G}\) at the end of the training phase. In addition to the underlying global data characteristics, it is noteworthy that each individual MEC server has its own data characteristics. Hence, to enable the model to efficiently adapt to the dynamic nature of the data, it is necessary to retrain the model using the most recent local data. Particularly, at the start of each operation time slot, local models are trained using the local data from the previous time slot for a duration of \(\epsilon\) epochs. Once the training process is finished, the resulting local model \(w_{m}\) is used to choose the most suitable cache services.  
The local model \(w_{m}\) comprises trained sub-networks, namely \(\mathbf{q}_{\phi}\) and \(\mathbf{p}_{\theta}\). Consequently, a new data sample \(\hat{R}_{u}(t_{m})\) can easily be generated from the input data \(R_{u}(t_{m})\). The latent space can be derived from the input data \(\mathbf{z}\sim\mathbf{q}_{\phi}(\mathbf{z}|R_{u}(t_{m}))\). Additionally, new data samples can be obtained using \(\hat{R}_{u}(t_{m})\sim\mathbf{p}_{\theta}(\hat{R}_{u}(t_{m})|\mathbf{z})\).  
The output matrix \(\hat{Q}_{m}(t_{m})\in\mathbb{R}^{U\times S_{all}}\) is received by each MEC server from the trained model and input data \(Q_{m}(t_{m})\). The rows of the matrix \(\hat{Q}_{m}(t_{m})\) represent individual users. In contrast, the columns represent all of the services available within the system. The values of the same service requested by all the users are accumulated. Consequently, the output matrix \(\hat{Q}_{m}(t_{m})\) is transformed into a popularity score vector denoted by \(D_{m}(t_{m})\in\mathbb{R}^{1\times S_{all}}\). This vector is determined as follows:  
\[D_{m}(t_{m})=\big{\{}d_{i}^{m}(t_{m}),1\leq i\leq S_{all}\big{\}}, \tag{13}\]  
where \(d_{i}^{m}(t_{m})\) denotes the popularity score of service \(i\) on MEC server \(m\) in operation time slot \(t_{m}\). Utilization of the popularity score of each service by each MEC server enables the determination of suitable services for each \(t_{m}\).
## 4 Cognitive Radio Combined with WBAN  
A WBAN comprises a 3-Tier architecture, in which Tier-1 is an intra-WBAN communications, as referred in Figure 2. It consists of different types of medical sensor; all the individual sensors measure the vital signal, process it, and then combine it and communicate it to the BNC [20]. The Cognitive Radio Controller (CRC) is a central unit that controls the communication parameters of BNC for sensor device communication. The 3.1-10.6 GHz UWB spectrum is divided into 14 sub-bands of 528 MHz; then, the UWB from 3.1 to 4.8 GHz is divided into three sub-bands of 3232, 3960, and 4488 MHz for Tier-1 communications. The spectrum monitoring system is based on the spectrum used for the selection of the broadcast channel from the three sub-bands. The broadcast channel is stored in the memory of the BNC and in the medical sensor. The data transmission uses the sub-band for its communication. For Tier-2 communications, the enhanced propagation characteristics of any one of these three sub-bands is chosen. The data transmission by the AP monitors through the UWB spectrum, and broadcast information is obtainable through sub-bands. In Tier-3, the server is connected to the doctor. We analyze all three tiers in detail.
## 2 Fundamentals of PICs
The exceptional design flexibility provided by transformation optics facilitates the creation of innovative devices such as light source collimators, WG adapters, and WG crossings (Figure 2). These devices are highly applicable to integrated photonic chips and are well-suited to existing assembly methods. By means of the finite-difference time-domain (FDTD) method, full-wave numerical simulations were conducted to showcase the exceptional optical performance and efficient integration of these elements within on-chip photonic systems. These elements, requiring only spatially changing dielectric materials without magnetic properties, ensured low-loss, broadband operation in integrated photonic environments. The amalgamation of these components onto a single platform offers many advantages, such as reduced size, weight, and power consumption, improved performance and  
Figure 2: A diagram of a PIC featuring numerous transformation optics components. A collection of transformation optics-based photonic elements can be integrated with traditional optical and optoelectronic devices, such as WGs and PDs, on a shared planar substrate. These transformation optics components enable the construction of complex photonic devices and systems, offering diverse functionalities for applications in optical communications, information processing, and sensing. The red arrows indicate the light propagation, which can be managed by both the transformation optics components and on-chip EO devices [49]. reliability, and the potential for large-scale production using semiconductor fabrication techniques. Integrated photonics is revolutionizing various fields, from telecommunications, where it enables high-speed data transmission and processing, to sensing and imaging, where it provides enhanced sensitivity and resolution. Furthermore, as technology advances, the integration of photonics with electronics (electro-photonics integration) promises even greater capabilities, enabling the development of next-generation devices that leverage the best of both worlds. The future progress of integrated photonics hinges on developing compact, reliable optical components that can be seamlessly integrated on a single substrate.