esa-sceva/satcom-chunk-collection huggingface dataset:
# Photoconductive Semiconductor Switches: Materials, Physics, and Applications
## 6 GaAs PCSS Devices  
GaAs is among the earliest materials to be investigated as a PCSS substrate due to its early technological maturity, with research into GaAs switches commencing in the early 1980s, shortly after the first Si PCSS in 1975 [66]. It continues to justify research due to its very high crystalline quality, ability to be grown from a melt (by vertical gradient freeze and modified Czochralski techniques), high dielectric strength, and direct bandgap [67; 68; 69]. These properties enable devices with picosecond rise times and high breakdown fields despite its narrow (1.4 eV) bandgap (due to the ability to grow very thick films economically). Its direct bandgap makes it a much more efficient optical absorbing medium than Si or SiC, alleviating triggering requirements. It is also one of only three materials to have exhibited a high-gain  
Figure 8: \(\beta\)-Ga\({}_{2}\)O\({}_{3}\):Fe trap model with active impurities in the sample. Green arrows correspond to carrier generation and orange arrows correspond to internal transitions (re-generated from Ref. [61]).  
mode (separate effects referred to collectively as lock-on). Early work to extend switching lifespan to >10\({}^{4}\) shots increased both the optical power and trigger system complexity [70], primarily by seeding large numbers of current filaments in vertical devices, as pictured in Figure 9[5; 71; 72].  
Lock-on in a GaAs PCSS device was observed first by [PERSON] and coworkers at Sandia National Laboratories in 1987 [74; 75]. It was the first optically triggered latching behavior observed in a semiconductor switch (functionally comparable to latching in silicon-controlled rectifiers), generating \(\sim\)10\({}^{5}\) electron-hole pairs per trigger photon [5]. The observation of optical emission from current filaments propagating from the location of the laser trigger between the two electrodes is ubiquitous in lock-on mode, and is not observed during linear-mode operation, leading to the basis for claims of lock-on (distinct from surface flashover or breakdown) in other materials.  
GaAs has the drawback of poor durability due to low electrical and optical damage thresholds. Accordingly, the careful design of the optical trigger, including line-emitting lasers, optical beam splitters, and electrode design for large numbers of filaments, is required to achieve high power without damaging the device [71; 72]. These factors have limited production to specialized research applications, including pulse and kHz amplifiers [76; 77].
# MPEG and DA-AD Resilient DCT-Based Video Watermarking Using Adaptive Frame Selection
## 4 Experimental Results
### Experimental Setup
#### 4.1.2 Experimental Setup  
The evaluation was conducted as follows. First, we embedded 16-bit data information into the original video sequences through the watermark embedding process. Next, the watermarked video clips were encoded with various compression quality factors using the MPEG-4 part 10 (H.264) codec.  
Using a digital-to-analog (DA) converter, the compressed video sequences were converted into an analog signal. To process the DA conversion, a 'Fosmon HDMI to component video (YPbPr)/VGA & SPDIF output converter box' was adopted, as shown in Figure 5a. An analog component video (YPbPr) was selected as the format for the analog signal because YPbPr accommodates a full-HD display resolution (1080p).  
The analog YPbPr signal was reconverted into a digital signal. In addition, the converted digital video was saved in an uncompressed YUV422 video format. For this process, we adopted'skyHD captureX HDMI' as the AD converter, as shown in Figure 5b. The frame rate and display resolution of the converted digital video (1280 \(\times\) 720) differed from those of the input video. Finally, we detected the embedded watermarks in the video frames using a watermark extraction algorithm. The extracted watermark patterns were  
Figure 4: Overall test procedure of the proposed video watermarking system.  
decoded into 16-bit data based on the indices of the predefined pseudo-random patterns, and the bit error rate (BER) of the bit data was computed.  
To optimize the invisibility and robustness of the watermarked frames, several parameters of the proposed algorithm should be carefully set. Here, we selected a length of N = 25,000 from the fixed location of the DCT coefficient. It was empirically determined that this choice yields the maximum MPEG robustness while preserving the imperceptibility.
_applied_  
_sciences_  
_Article_  
**Examination of Couette Flow with a Pressure Gradient and Heat Conduction Using Molecular Dynamics Simulation**  
[PERSON]\({}^{1,\ast}\)\({}^{\copyright}\) and [PERSON]\({}^{2}\)  
\({}^{1}\) Mechanical Engineering Department, Gebze Technical University, Kocaeli 41400, Torkiye  
\({}^{2}\) Aeronautical Engineering Department, Gebze Technical University, Kocaeli 41400, Torkiye;  
\({}^{\ast}\) [PERSON]DDRESS]  
\({}^{2}\) Aeronautical Engineering Department, Gebze Technical University, Kocaeli 41400, Torkiye;  
\({}^{\ast}\) [PERSON]DDRESS]  
\({}^{\ast}\) Correspondence: [EMAIL_ADDRESS]  
**Featured Application: This study aims to fill a knowledge gap in rarefied gas flows, addressing the complexities related to wall temperatures and pressure differentials in the simulation of gas-solid interactions in nanoscale and microscale geometries. The findings are relevant to diverse microfluidic applications, encompassing devices such as micro-nano electronic devices. Simulations were carried out in non-dimensional form so that the results can be extended to all noble gases.**  
**Abstract: As computer capabilities improve, Molecular Dynamics simulations are becoming more important for solving various flow problems. In this study, Couette and Poiseuille flows at different wall temperatures were investigated using a hard-sphere Molecular Dynamics simulation approach. Although a low spacing ratio was used in the simulations, the results are valid for rarefied gas flows when proper scaling based on the Knudsen number was used because only binary collisions with a hard-sphere model were considered. The main focus of this study was the examination of the effects of various wall speeds, pressure gradients, and wall temperatures. A pressure gradient was generated by developing a modified selective periodicity condition in the flow direction. With the combined effect of the pressure gradient and the wall velocities, subsonic, transonic, and supersonic speeds in nanochannels were examined. With the combination of different parameters, 1260 simulation cases were conducted. The results showed that there are temperature and velocity slips that are dependent on not only the temperature and velocity values but also on the magnitudes of a pressure gradient. The pressure gradient also caused nonlinearities in temperature and velocity profiles.**  
**Keywords: molecular dynamics; simulation; hard-sphere; Couette flow; pressure gradient**
# Robust Learning from Demonstration Based on GANs and Affine Transformation
## 3 Proposed Method
### Preprocess Method
#### 3.2.2 Bezier Curve Representation  
After recording the demonstrations, we require a method that not only represents these trajectories but also generates additional trajectories. The Bezier curve is employed to fulfill these requirements. A second-order Bezier curve is defined by three control points \(P_{0},\ P_{1},\ P_{2}\), where \(P_{0}\) and \(P_{2}\) are the start and end points of the curve, and \(P_{1}\) is the middle control point that influences the shape of the curve. The mathematical expression of the second-order Bezier curve is:  
\[B(t)=(1-t)[(1-t)P_{0}+tP_{1}]+t[(1-t)P_{1}+tP_{2}],0\leq t\leq 1. \tag{12}\]  
By varying the parameter \(t\) between 0 and 1, we can generate any points desired between the control points. Consequently, demonstration data can be augmented by generating points with different sampling rates for training the neural network.  
Another advantage of representing trajectories using Bezier curves lies in their ability to abstract temporal intricacies. When sampling a new trajectory from the curve, the sequential order of samples accurately mirrors the original trajectory's sequence. This adherence to the correct order serves to circumvent abrupt transitions when the trajectory is executed by a robotic arm.
## 4 Materials and Methods
### Proposed SMSRS Model
#### 4.1.1 Development of SRA Model  
SRA model was developed in MS excel following the steps below:  
1. Determine the optimistic \(a\), and pessimistic \(b\) durations of each activity duration  
The optimistic \(a\), most likely \(m\) and pessimistic \(b\) durations for each activity were established. Note that, in the triangular probability distribution, \(a\), \(m\) and \(b\) values are required to generate random variables. Here, \(m_{i}\) is the given duration for each activity while \(a_{i}\) and \(b_{i}\) can be determined using expert judgment through survey, historical records, etc. However, in this study we determined \(a_{i}\) and \(b_{i}\) of each activity by multiplying \(m\) with fictitious values 0.8 and 1.5, respectively.
2. Generate random numbers between 0 and 1  
Random numbers between 0 and 1 were generated using the excel function _RAND ()_ representing the probability occurrence of each variable.
3. Generate a random activity duration for each activity  
Unlike other probability distributions whose random variables generating functions are available in excel, the triangular probability distribution function is not. Therefore, Equation (1) [18] was used in MS excel to generate the random duration for each activity.  
\[Dur_{Rand_{i}}=1F\Big{(}Rand_{i}\leq(m_{i}-a_{i})/(b_{i}-a_{i}),a_{i}+\sqrt{ Rand_{i}*(m_{i}-a_{i})*(b_{i}-a_{i})},b_{i}-\sqrt{(1-Rand_{i})*(b_{i}-m_{i})*(b_{i}-a_ {i})}\Big{)} \tag{1}\]  
where \(Rand_{i}\) is the random number generated for activity \(i\) and \(Dur_{Randi}\) is the random duration for activity \(i\).
4. Run Monte Carlo simulation for each activity duration  
Each random activity duration generated was simulated 1000 times using the Monte Carlo simulation method. The average of 1000 iterations for each activity was calculated, which is the expected duration for each activity. Each time F9 is pressed on the keyboard, a new set of random durations are generated. In this way, the risk and uncertainty which may affect the activity durations were accounted for. The resultant expected activity durations (stochastic) were used as input for the development of the stochastic multi-skilled resource schedule. The results of these procedures are shown in Table 3.
# An Improved Method for Evaluating Image Sharpness Based on Edge Information
## 3 Experimental Results and Analysis
### Running Time Evaluation  
In the previous subsections, we experimentally verified that our proposed method was superior to the other two methods in terms of content irrelevance and subjective-objective consistency. In the following, we evaluated 29 clear reference images in the LIVE database using each of the above three evaluation methods and then obtained the time required to process one image for each method by averaging, as shown in Table 4. It should be noted that the experiment in this section was conducted on a PC with a 2.9 GHz CPU, 16 G RAM, and an NVIDIA GeForce RTX 2060.  
From the experimental data in Table 4, it can be seen that the proposed method had more obvious advantages in terms of running time compared to the other two methods. This is actually due to the fact that we adopted the less computationally intensive eight-neighborhood grayscale difference method to determine the edge directions of the edge points while reference [14] requires at least two Sobel convolution operations on the measured image, making its running time significantly slower than our method. Additionally, we noticed that both the methods in this paper and in reference [14] were faster than the Tenegrad method. This fully illustrates that the edge information-based image sharpness evaluation methods have the advantage of being faster than the Tenegrad method based on the contrast principle. Therefore, our method is more suitable for application in scenes with heavy real-time requirements.
###### Abstract  
This paper proposes a single-stage, high power-factor light-emitting diode (LED) driver with a self-excited control scheme for the power switches. The self-excited mechanism is accomplished by fetching the driving voltages from a center-tapped transformer. The frequency of the driving voltages is exactly the same as the resonant frequency of the resonant converter, thus synchronizing the resonant frequency with the switching frequency and achieving zero-voltage switching (ZVS) and zero-current switching (ZCS) of power switches. The circuit topology is mainly composed of a half-bridge LC resonant converter, along with a boost-type power-factor corrector (PFC) to fulfill the single-stage structure, meaning that the presented LED driver possesses high power-factor features and low switching loss. Finally, a 40 W prototype circuit is implemented and tested, and the experimental results exhibit a satisfactory performance.  
Keywords:light-emitting diode (LED); power-factor correction; self-excited; single stage; soft switching +
Footnote †: journal: Applied Sciences
## 3 Numerical Results
### OP Dependence on the Inter-Core Skew of Multiple Interfering Cores  
All preceding results have considered that all interfering cores had the same SSRP. In the following, the OP is assessed for \(L=80\) km, for \(r=0\) and \(r=0.1\), for two interfering cores, in which one core has \(|S_{mn}\cdot R_{s}|=0.01\) and the other core has \(|S_{mn}\cdot R_{s}|=1000\). Weakly-coupled MCFs with cores with substantially different skews can be found in practice [14; 16].  
Figure 5 shows the OP as a function of the ICXT level, for \(L=80\) km, for two interfering cores, with the same SSRP and with different SSRPs, for (a) \(r=0\) and (b) \(r=0.1\). It can be seen that having two interfering cores with different SSRPs leads to an intermediate situation, in comparison to having both cores with \(|S_{mn}\cdot R_{s}|=0.01\) or \(|S_{mn}\cdot R_{s}|=1000\). When using different SSRPs in each core, the maximum acceptable ICXT level required to achieve OP \(=10^{-4}\) is 2 dB higher and 1.5 dB lower, for \(r=0\), and 2.5 dB higher and 5.3 dB lower, for \(r=0.1\), in comparison to having both cores with \(|S_{mn}\cdot R_{s}|=0.01\) or \(|S_{mn}\cdot R_{s}|=1000\), respectively. Figure 5 shows that, especially for \(r=0.1\), the effect of having only one core with low SSRP is enough to induce a severe degradation of the maximum acceptable ICXT level for a specific OP, even if the other interfering cores have a small contribution to the maximum acceptable ICXT level, as in the case of high SSRP.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & \(r=0\) & & & \(r=0.1\) & \\ \hline \(|S_{mn}R_{s}|\) & \(N_{i}=1\) & \(N_{i}=2\) & \(N_{i}=4\) & \(N_{i}=1\) & \(N_{i}=2\) & \(N_{i}=4\) \\ \hline \(0.01\) & \(-23.3\) & \(-26.3\) & \(-29.5\) & \
# Framework Based on Simulation of Real-World Message Streams to Evaluate Classification Solutions
## 2 Proposed Framework  
This paper proposes a framework based on the simulation of real message streams for the evaluation of classification solutions. The proposed framework aims to provide researchers (especially data scientists) in the area of text stream classification with an environment that facilitates the evaluation of text message processing and/or classification solutions. The proposal is designed to facilitate the integration of existing processing and/or classification solutions, mainly in the form of web services, for evaluation with the generated message streams or as a basis for comparison with other solutions. Figure 1 shows a view of the framework architecture, which aims to make this framework as versatile as possible, with the ability to adapt and readjust the technological resources to the changing situation at any time, and which follows a similar scheme to the architecture proposed in [19]. An architectural style based on n-layer architectures has been used, structuring the elements into levels.  
The front-end level defines the elements needed to interact with end users, grouped under the concept of the framework user interface and organised according to the model, view, controller (MVC) architectural pattern. The framework front-end is intended for the data scientists, and is based on a graphical user interface (GUI). The API level contains the service that acts as an application programming interface (API) for the other of the services. This allows for the centralised exposure of all the endpoints defined in the backend. This level is the core of the solution and consists of five main modules: Framework Core, Message Stream Simulation, Message Processing, Classification, and Evaluation. Each of the modules in the service level accesses the data level through the persistence services in the service layer (Figure 1 shows the relationship between the services and their main data sources, with dashed lines to indicate that this relationship is indirect). The following is a description of each of the core-level modules that make up the proposed framework.
## 2 Instrument  
### Coherent Doppler Wind Lidar  
In this work, an all-fiber CDWL was deployed to provide the atmospheric wind profiles and backscatter measurements. The lidar system emits a laser at a wavelength of 1548 nm, with a pulse energy of 110 \(\upmu\)J, a repetition frequency of 10 kHz, and a pulse full width at half maximum of 200 ns. A 100 mm diameter telescope was used as a coaxial transmitter and receiver, and then, the backscatter was coupled with the local oscillator light and finally detected by the balanced detector (BD), with a noise bandwidth of 200 MHz.  
Aiming at studying the transport and sedimentation of Taklimakan desert dust, the CDWL was employed in Minfeng, Xinjiang province, China (82.69\({}^{\circ}\)E, 37.06\({}^{\circ}\)N). In response to the instability caused by the large diurnal temperature variation, the lidar system was designed with an all-fiber structure and temperature control system. The CDWL was operated in a velocity azimuth display (VAD) scanning mode during the experiment, and the elevation angle was set to 70\({}^{\circ}\). The scanning range of the azimuth angle is from 0\({}^{\circ}\) to 360\({}^{\circ}\), where 0\({}^{\circ}\) corresponds to the north and 90\({}^{\circ}\) corresponds to the east. The step of the azimuth angle is 12\({}^{\circ}\), and the period of one scan is about 1 min. The radial range resolution was set to 30 m/60 m/150 m in the range of 0-3 km/3-6 km/6-15 km. In our previous work, the performance of wind measurements was validated; the standard deviationsof wind speed and direction were 0.84 m/s and 9.2\({}^{\circ}\), respectively [23]. The key system specifications are listed in Table 1.
# Research on an Optimal Path Planning Method Based on A* Algorithm for Multi-View Recognition
###### Abstract  
In order to obtain the optimal perspectives of the recognition target, this paper combines the motion path of the manipulator arm and camera. A path planning method to find the optimal perspectives based on an A* algorithm is proposed. The quality of perspectives is represented by means of multi-view recognition. A binary multi-view 2D kernel principal component analysis network (BMZDKPCANet) is built to extract features. The multi-view angles classifier based on BMZDKPCANet + Softmax is established, which outputs category posterior probability to represent the perspective recognition performance function. The path planning problem is transformed into a multi-objective optimization problem by taking the optimal view recognition and the shortest path distance as the objective functions. In order to reduce the calculation, the multi-objective optimization problem is transformed into a single optimization problem by fusing the objective functions based on the established perspective observation directed graph model. An A* algorithm is used to solve the single source shortest path problem of the fused directed graph. The path planning experiments with different numbers of view angles and different starting points demonstrate that the method can guide the camera to reach the viewpoint with higher recognition accuracy and complete the optimal observation path planning.  
multi-view recognition; path planning; A* algorithm; perspective selection +
Footnote †: journal:  
00 000-0001-9500-0001-9500][PERSON]  
1 School of Mechanical Engineering, Shandong University of Technology, Zibo 255000, China; 1 [EMAIL_ADDRESS] (N.L.); [EMAIL_ADDRESS] (Q.H.); [EMAIL_ADDRESS] (N.W.); 1 wh_322@sduetd.ucn (H.W)
## 2 Materials and Methods
Electrodes were prepared by blending 70 wt.% Super C45 (IMERYS) and 30 wt.% Na-carboxymethylcellulose (CMC, Dow Wolff Cellulos, Bomlitz, Germany) in deionized water. The so-obtained slurry was cast onto Al foils (30 \(\upmu\)m thick), initially dried in external atmosphere (to massively remove the aqueous solvent). Coin-electrodes (10 mm diameter) were punched and then heated under vacuum at 150 \({}^{\circ}\)C overnight (glass oven) prior to being introduced in the glove-box. The electrochemical cells were manufactured (within the glove-box) by housing the carbon electrode, a glass fiber separator (16 mm diameter) and a lithium disk (10 mm diameter) into 2032 MTI containers. The IL electrolyte was initially spread (20 \(\upmu\)L) onto the carbon electrode and then dropped (30 \(\upmu\)L) onto the separator. Prior to sealing, the cells were subjected to a 30-min vacuum step to allow the full loading of the carbon electrode and separator by the viscous electrolyte. Cyclic voltammetry (CV) tests were carried out on the Li/Carbon cells in the 3.0-5.0 voltage range (1 mV s\({}^{-1}\)) at 20 \({}^{\circ}\)C (Binder climatic chamber). Infrared spectroscopy measurements were conducted both in the mid- and in the far-infrared range. In the former range, an Agilent 660 spectrometer (Agilent Technologies, Santa Clara, CA, USA) with a DTGS detector and a KBr beamsplitter was used. In the far infrared range, we used the IFS125 spectrometer ([PERSON], Billerica, MA, USA) of the AILES beamline of Soleil Synchrotron with a Mylar beamsplitter and a bolometer as detector. For both configurations, the sample was placed in a vacuum tight cell for liquids equipped with diamond optical windows, in order to avoid contaminations from air or moisture. The spectral resolution was fixed to 1 cm\({}^{-1}\) for both spectrometers. A Specac Variable Temperature Cell (Specac Ltd., Oprington, UK) and a Cryomech cryocooler (Syracuse, NY, USA) allowed us to vary the temperature of the sample in the mid- and in the far-infrared range, respectively. The infrared spectra of the possible conformers of the FTFSI anion were obtained by means of DFT calculation at the B3 LYP level of theory, combined with the 6-31G** basis set. Calculations were performed by means of the Firefly software [36; 37]. Starting from the geometry of the three conformers reported by [PERSON] et al. [28], we re-optimized the structures by means of DFT calculations and the vibration frequencies and the infrared intensity were calculated. To compare the calculated IR spectra with the experimental ones, the former was simulated as the sum of Gaussians curves with maxima at each calculated vibration frequency, a fixed 10 cm\({}^{-1}\) linewidth and an intensity proportional to the calculated one.