esa-sceva/satcom-chunk-collection huggingface dataset:
# Quaternion Codes in MIMO System of Dual-Polarized Antennas +
## 4 Quaternionic Channel Model
Moreover, the noise \(\mathbf{N}=[n_{T\sigma}]^{T}\), and \(n_{T\sigma}=n_{T\sigma 1}+n_{T\sigma 2}j\), such that \(n_{T\sigma 1},n_{T\sigma 2}\)\(\forall\)\(\sigma=\{1,2,\ldots,N_{r}\}\), represent the entries of white noise as two dimensional independent and identically distributed (i.i.d.) complex Gaussian RVs with zero mean and identical variance per dimension. Linear and Decoupled ML Decoder  
Based on the system model given in (19), the following theorem confirms a linear decoupled solution at the receiver for all QODs constructed in Section 2. It was previously proved for non-iterative QODs in [18] but we now confirm its validity for all QODs obtained in Section 2. Theorem 4.2: _For a given system model in (19), the ML-decoding rule assumes a linear decoupled form_  
\[\min_{z}||\mathbf{R}-\mathbf{Q}\mathbf{H}||^{2}=\min_{z}\Big{(}tr(\mathbf{R} ^{Q}\mathbf{R})+\lambda tr\big{(}\mathbf{H}^{Q}\mathbf{H}\big{)}-2\Re\big{(} tr\big{(}\mathbf{R}^{Q}\mathbf{Q}\mathbf{H}\big{)}\big{)}\Big{)}. \tag{20}\]  
The main contributing factor in the above rule is \(\Re\big{(}tr\big{(}\mathbf{R}^{Q}\mathbf{Q}\mathbf{H}\big{)}\big{)}\), which needs to be minimized for any transmitted symbol encoded as a quaternion in a given time slot. The appearance of \(\mathbf{Q}\) indicates the linearity of the decoder as well as the computational load at the receiver is reduced significantly. As an illustration of the above result, we choose QODs given in (4) and (6) and demonstrate that the above ML-decoding rule is both linear and decoupled. For remaining QODs \(\mathbf{Q}_{3},\mathbf{Q}_{4},\mathbf{Q}_{5}\) and \(\mathbf{Q}_{6}\) in (9), (11), (14), (15) respectively, a similar decoding result can be obtained easily. **Corollary 1**. : _The ML-decoding rule (20) for QOD given in (11), reduces to the real part of_  
\[-2\min_{z_{1}}(r_{1}^{Q}z_{1}(h_{1}+jh_{2})+r_{2}^{Q}z_{1}^{*}(jh_{1 }+h_{2})+r_{3}^{Q}z_{1}^{*}(1+j)h_{3})\;,\] \[-2\min_{z_{2}}(r_{1}^{Q}z_{2}(jh_{1}+h_{2})-r_{2}^{Q}z_{2}^{*}(h_{1 }+jh_{2})+r_{4}^{Q}z_{2}^{*}(1+j)h_{3})\;,\] \[-2\min_{z_{3}}(r_{1}^{Q}z_{3}(1+j)h_{3}-r_{3}^{Q}z_{3}^{*}(h_{1}+ jh_{2})-r_{4}^{Q}z_{3}^{*}(jh_{1}+h_{2}))\;, \tag{21}\]  
_where \(\mathbf{R}=[r_{1}\ r_{2}\ r_{3}\ r_{4}]^{T}\), is a received quaternion vector and \(h_{1}=h_{11}+h_{12}j\), \(h_{2}=h_{21}+h_{22}j\) and \(h_{3}=h_{31}+h_{32}j\)._  
We now broaden our discussion to include designs, which have significantly higher code rates than those obtained from the approaches discussed in this paper. In order to do that we need to compromise on orthogonality in which case it is not possible to have decoupled linear decoder like (20). It turns out that such quasi designs have other features to offer. Subsequently, we construct these quasi QODs by extending the standard approach as developed for the complex domain [16].
## 2 Materials and Methods
### Preparation of Starch/MCC Films  
The biocomposite films reinforced with MCC were prepared by a casting method [27]. Briefly, the cassava starch (5 g) was boiled in 50 mL of deionized water at 70 \({}^{\circ}\)C under constant stirring for 30 min, while MCC (0.05, 0.15, and 0.25 g) in 50 mL of deionized water were ultrasonicated at 25 \({}^{\circ}\)C for 30 min. Both cassava starch solution and MCC suspension were mixed at 70 \({}^{\circ}\)C under constant stirring for 30 min. Then, glycerol as plasticizer (1.5 g) was added and stirred at 70 \({}^{\circ}\)C for 3 h. The mixture solution was cast on the polystyrene plate and dried in the hot air oven at 60 \({}^{\circ}\)C for 24 h. All film samples were equilibrated in the desiccator at 25 \({}^{\circ}\)C, with a relative humidity of 50 \(\pm\) 5% before characterization. The film formulations are shown in Table 1.  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Formulations**} & **Cassava Starch** & **Glycerol** & **MCC** & **Deionized** \\  & **(g)** & **(g)** & **(g)** & **Water (mL)** \\ \hline \hline \multirow{2}{*}{Starch} & 5 & 1.5 & 0 & 100 \\  & 5 & 1.5 & 0.05 & 100 \\  & 5 & 1.5 & 0.15 & 100 \\  & 5 & 1.5 & 0.25 & 100 \\ \hline \hline \end{tabular}
\end{table}
Table 1: The film formulation with various MCC contents.
# Kinematic In Situ Self-Calibration of a Backpack-Based Multi-Beam LiDAR System
## 5 Discussion  
In this section, the effectiveness of the proposed self-calibration method is discussed in terms of accuracy, time, and cost. First, a comparative analysis between the previous MBL self-calibration approaches and the proposed one is carried out. Table 17 shows the performances (i.e., accuracy and improvement) of five representative MBL calibration approaches and the proposed one. At this stage, one should note that a direct comparison of the performances among different approaches is almost impossible since their sensor systems, methods, datasets, environments, computational performances are all different. Nevertheless, the comparison in Table 17 shows the overall performances of the approaches. Although there is a variance in the type of MBL sensors, our method achieved a fair improvement (35-81%) compared to other results. In particular, [PERSON] [29] and [PERSON] and [PERSON] [30] performed kinematic calibrations of MBL mounted on a vehicle platform. In these approaches, the RMSEs of planar misclosure after the calibration were 0.023 and 0.014 m, respectively, which are higher than the proposed case. This is due to the fact that vehicle moving speed is much faster than human walking speed, causing a higher measurement noise level. The proposed approach showed a similar (or somewhat better) level of RMSE to the static calibrations.  
Figure 20: Estimated AP values and their standard deviations versus vertical angle for Calibration V: (**a**) range offset; (**b**) horizontal angle offset; (**c**) vertical angle offset.  
Secondly, the proposed kinematic self-calibration of the backpack-based MBL system can significantly reduce time and cost compared to the traditional target-based static calibrations. The proposed one does not need an installation of targets and tripods to fix the scan location since it is aiming for kinematic in situ calibration. Although the proposed method is not fully automatic, the running time of the whole process takes up to 30 s (under the condition of 2 scans, 3 planes, and around 2000 points), except for the manual plane matching. The computer processor is an AMD Ryzen 5 1600 six-core processor with DDR-4 16 GB 1500 MHz of RAMs. The program for the whole process is written in MATLAB. The program and the algorithm are not yet optimized, and the processing time can be improved in the future study.
# Kinematic Analysis and Verification of a New 5-DOF Parallel Mechanism
## 3 Kinematic Analysis
### Algorithm Simulation  
In this mechanism, radius of outer circle of geometric center of Hook joint fixed on five sliders \(R=135\) mm. The distance from the spherical hinge to the geometric center of Hook joint \(L_{i}=205\) mm. The coordinate values of the five spherical hinges rotation centers in the moving coordinate system are \(x_{1}=35\) mm, \(y_{1}=51\) mm, \(x_{2}=-35\) mm, \(y_{2}=51\) mm, \(x_{3}=-51\) mm, \(y_{3}=-35\) mm, \(x_{4}=51\) mm, \(y_{4}=-35\) mm, \(x_{5}=0\) mm and \(y_{5}=51\) mm. On the premise of \(x=0\) and \(\beta=0^{\circ}\), the trajectory curve equation of the center point of the moving platform is:  
\[\left\{\begin{array}{l}\alpha=\frac{\pi}{3}+\frac{1}{30}\pi t,\ (0<t<10)\\ y=50\cos\alpha\\ z=-50\sin\alpha\end{array}\right. \tag{13}\]  
The geometric center target track of the moving platform is shown Figure 8.  
The position change trajectories of the five sliders corresponding to this condition are obtained by inverse position solution formula as shown in Figure 9. The simulation results of the position curve show that the position change curves of the five sliders on the ball screw can be obtained by inverse position solution equation as long as the motion path of the moving platform is known, which lays a foundation for the control of the mechanism.  
The velocity curves of the five sliders under this condition are obtained by taking the derivative of the inverse position equations with respect to time, as shown in Figure 10.  
The acceleration curves of the five sliders under this condition are obtained by taking the second derivative of the inverse position equations, as shown in Figure 11.  
Figure 8: The motion path of the moving platform.  
Figure 9: Position curves of sliders.  
The acceleration simulation results of five sliders show that the position, speed, and acceleration images of the sliders correspond to each other, and the absolute value of acceleration increases when the slope of the speed curve increases. The maximum absolute acceleration of the five sliders is 0.47 mm/s\({}^{2}\), and this position is the end of the curve. The larger acceleration value is caused by the smaller angle between the fifth limb and the _XOY_ plane of the fixed coordinate system. If the movement continues according to this trend, the fifth limb will be parallel to the fixed platform, and a singularity will occur. Therefore, when planning the target curve of the moving platform, the workspace of the mechanism should be fully considered and the target curve should be strictly controlled within the workspace. The simplest way is to ensure the position of five sliders above the moving platform. On this basis, the speed and acceleration values of the five sliders are analyzed to provide the basis for motor drive control in the later stage.
# SIV: Raise the Correlation of Second-Order Correlation Power Analysis to 1.00
## 7 Conclusions  
In this paper, we proposed a special intermediate value, SIV, that has a unique characteristic.  
The SIV improves the SOCPA performance significantly because it can accurately model power consumption and retain the theoretical correlation of 1-bit intermediate value. When the length of the intermediate value is 8, existing researches have only improved the correlation to 0.35, but the SIV has remarkably raised the correlation to 1.00. That is, the MTD for the General SOCPA requires at least 8.1633 times more traces than the FOCPA, whereas the SIV-based SOCPA is theoretically the same as the FOCPA.  
We analyzed the OpenSSL, which is the most commonly used open-source secure socket layer, and confirmed that there exists the SIV. Consequently, the proposed SIV-based SOCPA can disclose the whole secret key using only a quarter of the trace required by the General SOCPA. Further, we recommended two countermeasures as a guideline for implementing a cryptographic algorithm that is resistant to the proposed method.  
The limitation of the proposed method is that it has to discover the SIV for each cryptographic algorithms or implementation. In this paper, only the AES was analyzed. Finding the SIV from other cryptographic algorithms is an interesting further work. Thus in the future, we are going to apply to the proposed method for other cryptographic algorithms.  
Writing-original draft, J.-H.K., B.-Y.S. and D.-G.H.; Writing-review and editing, J.-H.K., B.-Y.S. and D.-G.H. All authors have read and agreed to the published version of the manuscript. This research received no external funding. This work was supported by Institute for Information & communications Technology Promotion(IITP) grant funded by the Korea government(MSIT) (No. 2017-0-00520, Development of SCR-Friendly Symmetric Key Cryptosystem and Its Application Modes). Additionally, this work was supported as part of Military Crypto Research Center(UD17/0109 ED) funded by Defense Acquisition Program Administration(DAPA) and Agency for Defense Development(ADD). The authors declare no conflict of interest. The following abbreviations are used in this manuscript:  
SIV Sparse intermediate value  
CPA Correlation power analysis  
FOCPA First-order correlation power analysis  
SOCPA Second-order correlation power analysis  
HW Hamming weight  
MSB Most significant bit  
PC Product-combining  
AD Absolute-difference  
AES Advanced encryption standard
## 4 Modulation Schemes
### Communication Distance  
To overcome the limitations of the traditional OOK scheme, several studies [13; 23; 31] have investigated undersampling modulation schemes for OCC, including UFSOOK and undersampled phase-shift OOK (UPSOOK). UFSOOK can be used for both rolling-shutter and global-shutter cameras; however, this technique suffers from considerably low data rates [15].  
RGB LEDs can be used to communicate over long distances using UPSOOK [13]. Several researchers have developed the color-shift keying (CSK) [26; 27; 28], the undersampled quadrature-amplitude-modulation subcarrier modulation (UQAMSM) [29], and the undersampled pulse-width modulation (UPWM) [31] for OCC. However, these modulation techniques are not useful for long  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Scheme**} & **RGB** & **Under** & **Frame Rate** & \multirow{2}{*}{**Data Rate**} & \multirow{2}{*}{**Distance**} & **Possible Application** \\  & **LED** & **Sampling** & & **(fps)** & & & **Scenarios** \\ \hline OOK [10] & \(\times\) & \(\times\) & 28 & 896 lps & 25 cm & LBS \\ UPSOOK [21; 23; 25] & \(\times\) & \(\surd\) & 30 [21] & 15 lps [21] & 40 cm [21] & V2X, LBS \\ CSK [26; 27; 28] & \(\surd\) & \(\times\) & 30 [26; 27] & 240 lps [26] & 50 cm [26] & LBS \\ UFSOOK [13] & \(\surd\) & \(\surd\) & 50 & 150 lps & 60 m & V2X \\ UQAMSM [29] & \(\times\) & \(\surd\) & 50 & 500 lps & 15. m & LBS \\ m-IM [30] & \(\surd\) & \(\times\) & 30 & \textgreater{}10 lkps & 2 m & Digital signage, LBS \\ UPWM [31] & \(\times\) & \(\surd\) & 30 & 150 lps & 1 m & LBS \\ DCO-OFDM [22] & \(\surd\) & \(\times\) & 30 & 55 Mps & 15. m & V2X, AR \\ CSK and multilevel PAM [12] & \(\surd\) & \(\times\) & 330 & 95 kbrgs & 1.2 m & V2X and large data transfer \\ \hline \hline \end{tabular}
\end{table}
Table 1: The features of the OCC modulation schemes and their applications.  
Figure 7: The depiction of the OCC-MIMO system.  
distances, although excellent BERs can be achieved. Another modulation technique called the spatial-2-phase-shift keying (S2-PSK) was proposed specifically for vehicular applications [2]. However, most of the techniques mentioned above do not solve the data rate issue. These techniques can be used in scenarios such as LBS and electronic healthcare (eHealth), where a low BER, rather than data rate, is the prime concern. All the above mentioned schemes can be employed in other environments, such as localized advertising, digital signage, and any outdoor applications, whereas other visible light communication technologies suffer from severe interference.
## 5 Simulation Calculation Model of Grouting
### The Impact of Various Factors on the Slurry Diffusion Radius
#### 5.4.2 The Influence of Different Drilling Speed on Slurry Diffusion Radius  
The numerical simulations were conducted under constant grouting pressure (0.3 MPa) and slurry viscosity (138.9 mPa\(\cdot\)s) conditions, while varying the drilling speed across a range of 0.1-0.5 m/min to systematically investigate its influence on slurry diffusion radius. The resultant diffusion patterns are presented in Figure 11.  
The relationship between slurry diffusion radius and drilling speed is obtained by regression analysis of the results:  
\[\begin{cases}R=0.236s^{-0.623}\\ r^{2}=0.985\end{cases} \tag{11}\]  
It can be seen from Equation (11) and Figure 10 that the slurry diffusion radius has a power function relationship with the drilling speed, and the slurry diffusion radius decreases with the increase of the drilling speed. When the drilling speed is 0.5 m/min, the slurry diffusion radius is the smallest, which is 32.7 cm. When the drilling speed is reduced  
Figure 11: The correlation between the slurry diffusion radius and drilling speed.  
Figure 10: Slurry diffusion at different grouting pressure levels: (**a**) 0.1 MPa; (**b**) 0.3 MPa; (**c**) 0.5 MPa.  
to 0.3 m/min, the slurry diffusion radius increases to 52.6 cm, an increase of 60.9%. When the drilling speed decreases from 0.3 m/min to 0.1 m/min, the slurry diffusion radius increases to 95.9 cm, an increase of 82.3%. It can be seen that in the actual construction process on site, different construction conditions have different optimal drilling speeds. The pursuit of too fast drilling speed will make the self-drilling anchor performance of the bolt not fully utilized, thus wasting construction resources. The slurry diffusion under different drilling speeds is shown in Figure 12. The smaller the drilling speed, the more uniform the slurry distribution.
# Risk-Based Access Control Model: A Systematic Literature Review
## 3 Risk-Based Access Control Model  
Commonly, the risk is the possibility of loss or injury. It is about some incident that may arise in the future and cause losses. According to [PERSON] [18], the risk is defined as \"_the possible damage that may arise from the existing operation or from some upcoming incident_\". The risk is found in numerous domains of our life. From the information technology security perspective, the security risk is defined as the damage that undesirably affects operation and its related information, while the process of understanding and mitigating against issues that may result in a breach of confidentiality, integrity, or availability of an information system is called risk management [18].  
Security risk in the access control context can be defined as the possibility of information leakage and the value of this information that may occur from accessing system resources [1]. Risk-based access control model utilizes the security risk as a criterion to make the access decision for each access request. This model is based on estimating the security risk value associated with each access request dynamically, and it then uses the estimated risk value to decide whether granting or denying access [4]. Mathematically, the most popular formula to represent the risk in a quantitative form is the likelihood/probability of an incident to occur multiplied by the impact regarding that incident [19].  
There are several methods to build a risk-based access control model. These methods have certain common features from different models. The main elements of a risk-based access control model are shown in Figure 2. The risk-based access control model comprises three key modules. The risk estimation is the main module, which gets access requests from users, analyzes them, collects the required information of risk factors, and estimates the security risk value related to each access request. Then, the estimated risk value is compared against access policies to decide the access decision whether granting or denying the access [20].
## 3 Results
### Overview of EO Studies in the EMMENA Region
richness [8], but EO applications on cultural heritage have a low contribution to the total number of studies (1.4%). A total of 495 citation topics were identified in Web of Science, of which the first 10 account for 46% of the total number of publications. These topics include the normalized difference vegetation index (NDVI) (9%), groundwater (6%), evapotranspiration (6%), landslides (6%), fuzzy sets (4%), ecosystem services (4%), aerosols (3%), geostatistics (3%), soil erosion (3%), and tectonics (2%). Most publications on EO applications in the EMMENA region used Landsat and Sentinel data, as identified by the keyword search on the publications' title, keywords, and abstract (Table 3). Sentinel-2 data (60.8%) and Sentinel-1 data (35.4%) are the most widely used among the Sentinel missions. Similarly, Landsat 8 (83.2%) and Landsat 7 (10.0%) are the most widely used data sources among the Landsat missions. The detailed analysis of the EO research according to the top 20 highly cited articles per thematic area will be described in the following subsection. Figure 5: Top 10 funding agencies based on the number of publications for papers on EO in the EMMENA region. \begin{table}
\begin{tabular}{c c c c} \hline
**Satellite Mission** & **Title** & **Keywords** & **Abstract** \\ \hline Landsat & 24.6 & 28.2 & 29.8 \\ Sentinel & 30.2 & 25.9 & 22.6 \\ MODIS & 12.6 & 17.5 & 14.1 \\ ASTER & 9.1 & 7.9 & 6.5 \\ GRACE & 3.3 & 3.9 & 3.4 \\ TRMM & 2.4 & 2.6 & 4.1 \\ SPOT & 1.7 & 1.2 & 1.3 \\ WorldView & 1.5 & 1.4 & 1.4 \\ PlanetScope & 1.5 & 0.7 & 0.6 \\ Other & 12.9 & 10.7 & 16.2 \\ \hline \end{tabular}
\end{table} 
Table 3: Percentages of satellite missions per appearance in the title, keywords, and abstract of EMMENA publications.
# Systematic Review of Discrete Event Simulation in Healthcare and Statistics Distributions
## 4 Discussion
### Technological Evolution of DES in Healthcare
#### 4.5.5 Implementation Challenges  
Despite these advancements, several challenges remain in implementing advanced DES technologies in healthcare. Through their analysis of healthcare simulation implementations, [PERSON] et al. [61] identified key barriers including data security concerns, integration with legacy systems, and the need for extensive staff training. [PERSON] et al. [62] further emphasized that successful implementation requires a phased approach that aligns with existing infrastructure and regulatory requirements.
## 3 Results and Discussion
### Micromorphology Observation  
The microphotography and EDS results of steel bars immersed in SCP solutions with different corrosion inhibitors are observed in Figure 13. Before photographing, the immersed steel bar was removed from the solution and dried. The polished steel bar showed a metallic luster, and there were polishing marks on the bars surface. A large number of yellow-brown corrosion products appeared on steel bar surface after the chloride attack. Corrosion products and chloride were also detected in the images. In the images, the passive film became incomplete and the corrosion occurred on most areas of steel bar surface, consequently, hindering the passive film formation in abundant chloride environment [59; 60]. Under the protection of calcium nitrite, the corrosion phenomenon  
Figure 11: Cyclic voltammograms (1 st and 5 th cycles) in SCP solution with inorganic corrosion inhibitor.  
Figure 12: Cyclic voltammograms (1 st and 5 th cycles) in SCP solution with multi-component corrosion inhibitor.  
becomes milder, which is embodied by disappeared corrosion products and visible polished marks. However, the Cl element can still be detected in the SEM and EDS results. When the organic corrosion inhibitor is adsorbed on the steel bar, corrosion pits and chloride are not detected, and the corrosion is effectively inhibited, owing to the formation of a protective film layer. In addition, consistent with the results mentioned above, a small number of corrosion pits was pictured on steel bar's surface with the protection of the inorganic corrosion inhibitor. The reaction products of the inorganic group, as described above, were detected in the SEM images and accumulated on the steel bar's surface. Moreover, no corrosion product or corrosion pit could be found in Figure 13f, proving that steel bar could be protected by multi-component corrosion inhibitors before the induction period of pitting corrosion.