esa-sceva/satcom-chunk-collection huggingface dataset:
# Using Smartwatches in Stress Management, Mental Health, and Well-Being: A Systematic Review
## 2 Method
### Inclusion and Exclusion Criteria  
We included studies that met five predefined criteria. First, they had to be peer-reviewed journal articles published in English with full-text access. Second, they had to be published between January 2016 and April 2025. Third, they had to examine the use of smartwatches or equivalent wearable devices for stress detection or mental health monitoring, including conditions such as anxiety or depression. Fourth, the study had to present original research--such as clinical trials, user studies, or experimental designs--with physiological data collected from smartwatches (e.g., heart rate, heart rate variability, or electrodermal activity). Fifth, studies had to use algorithmic methods (e.g., machine learning or signal processing) to interpret the data.  
We excluded studies that failed to meet the inclusion criteria upon full-text review. Specifically, we excluded non-English articles, non-peer-reviewed sources (e.g., editorials, newsletters, theses), and literature reviews or meta-analyses without original data. We also excluded studies focusing solely on smartphones, fitness bands, or other devices that lacked smartwatch-specific components, as these differ in sensing capabilities and usage context. Furthermore, we excluded articles unrelated to mental health outcomes--for example, those focusing solely on physical activity--and those lacking empirical results or a quantitative evaluation of stress or mental health prediction models.  
A study was considered relevant if it used smartwatches as the primary source of biometric data for stress or mental health monitoring and applied algorithmic techniques to analyze the collected signals.
## 5 Feasibility Study
### Performance Evaluation of Raspberry Pi Boards as Asterisk Server for LTC Applications
#### 5.1.5 Results
The ratio between the number of graceful transcoded VoIP calls to the number of graceful passthrough VoIP calls is proportional to the processing power of the board. The higher the processing power of the board, the higher the ratio of transcoded to passthrough VoIP calls the board can gracefully afford. Concerning the VoIP call quality metrics of established calls throughout the testing procedure, the results from Wireshark, as summarized in Table 2, show values of jitter and packet loss that all fall within the acceptable standardized limits of VoIP call quality metrics. 3. Passthrough vs. Transcoded VoIP Calls It is worth noting that the number of maximum simultaneous transcoded VoIP calls represents an extreme, where every originated call needs transcoding, of what actually happens in real situations. In most real cases, it is more likely that transcoding is avoided by enforcing particular audio codecs to be utilized by the communicating parties. Transcoding only happens when interconnecting with third-party providers, e.g., Internet Telephony Service Providers (ITSP), that operate other audio codecs to what we have already utilized. Therefore, we can posit that the maximum number of simultaneous VoIP calls that the Raspberry Pi boards can gracefully serve lays somewhere between the maximum number of passthrough VoIP calls and the maximum number of transcoded VoIP calls the specific platform can gracefully serve. The exact number of simultaneous VoIP calls depends on the application that defines the expected setup of the established VoIP calls. Figure 11: Contrasting the maximum number of simultaneous active channels that different Raspberry Pi board families can gracefully serve.
## 2 Materials and Methods
### Human Exposure Assessment  
To assess human exposure levels, we evaluated, for each configuration, the whole-body Specific Absorption Rate (SAR\({}_{\text{wb}}\)) defined as the power absorbed (per kg) over the entire body, the distribution of the Specific Absorption Rate averaged on 10 g of tissue (SAR\({}_{\text{10g}}\)) and the peak value of SAR\({}_{\text{10g}}\) (pSAR\({}_{\text{10g}}\)). We assessed these quantities for the most superficial tissues (e.g., the skin and eyes) and for the brain tissues of the Ella phantom. For the skin, the SAR\({}_{\text{10g}}\) distributions and pSAR\({}_{\text{10g}}\) values were evaluated at the whole-body and locally at the head, as the two 5G-V2X array antennas are positioned almost at the head level. For the brain, the SAR\({}_{\text{10g}}\) distributions and pSAR\({}_{\text{10g}}\) values were assessed in the whole brain, which included the brain grey and white matter, cerebellum, hippocampus, hypothalamus, hypothalamus, medulla oblongata, midbrain, pineal body, pons, thalamus and anterior and posterior commissure. Finally, regarding the eyes, the SAR\({}_{\text{10g}}\) distributions and the pSAR\({}_{\text{10g}}\) values were calculated in the cornea, sclera, lens and humor vitreous tissues. To better characterize the SAR\({}_{\text{10g}}\) distribution within and among tissues across the examined configurations, the quartile coefficient of dispersion (QCD), a unitless measure of the dispersion around the median, was calculated in each examined tissue as follows:  
\[\text{QCD}=\frac{(Q_{3}-Q_{1})}{(Q_{3}+Q_{1})} \tag{1}\]  
where \(Q_{1}\) and \(Q_{3}\) are the first and third quartiles of the distribution, respectively. Lastly, the percentage of values higher than 0.7 of the pSAR\({}_{\text{10g}}\) was reported for each tissue to investigate the spread of the SAR around the peak value.
# Applications of Pulsed Light Decontamination Technology in Food Processing: An Overview
## 5 Role of Pulsed Light Technology in Food Safety
### Food Contact Surface Decontamination  
Due to its superficial treatment characteristics, decontamination of food contact surfaces of equipment in processing plants could be achieved by PL technology [126]. However, there are only a few studies on the use of PL to sterilize equipment surfaces. [PERSON] and [PERSON] [127] investigated the role played by the surface topography of stainless steel on the efficacy of PL treatment. They obtained maximum reduction about 4 logs of _L. innocua_ in stainless steel having varied surface finishes and concluded that PL efficacy was less in highly smooth as well as highly rough surfaces due to surface reflectivity and hiding of cells in the rough surfaces, respectively. [PERSON] and [PERSON] [9] also showed in another experiment the effect of spectral range on PL on different stainless-steel surfaces inoculated with _L. innocua_. While obtaining a maximum of about 4 logs reduction, they concluded that the UV component of light necessary for PL based microbial inactivation. In another study, [PERSON] et al. [61] treated stainless steel coupons by PL of fluence 12 J/cm\({}^{2}\) to achieve about 4 log reductions of _L. innocua_. [PERSON] et al. [10] showed that Pulsed UV light could be used for decontamination of the stainless-steel meat slicing knife (contacted with different meat products prior to treatment). However, meat composition played a role in the treatment efficiency. Complete inactivation of _E. coli_ O157:H7 and _L. monocytogenes_ by a 6.5 log reduction per side of knife of was obtained in 60 s when the knife was used to cut meat having lower fat and protein content. In a different study, PLtreatment was shown be effective to inactivate hepatitis A virus and murine norovirus (food-borne viruses) on food-handling surfaces [65]. Hepatitis A virus and Murine norovirus were inactivated up to 5 logs in 3 and 2 s, corresponding to fluences of 0.06 and 0.091 J/cm\({}^{2}\), respectively. In another study, PL treatment was employed for reduction of murine norovirus on both clean and fouled (by protein) stainless steel surface. The fluence level of 8.98 J/cm\({}^{2}\) for 6 s resulted in an approximately 4 log reduction on a clean surface and a 2.6 log reduction on a fouled surface [121]. This indicates that protein on surfaces interferes with viral inactivation by PL. However, higher fluence value and exposure time can suffice for fouled surfaces. PL also has a great potential for treatment of biofilms. Varying treatment conditions can help in obtaining greater efficiency in PL processing. Thus, the decontamination of food-contact and equipment surfaces is another promising area of PL application in the food industry.
# UAV-BS Site Planning Based on Circular Coverage Strategy
## 3 Theory
### Basic Concepts  
(1) Convex Set: If for any two points \(x_{1},x_{2}\) in the set \(S\) and for any parameter \(t\in[0,1]\), Equation (1) is satisfied, then \(S\) is called a convex set.  
\[tx_{1}+(1-t)x_{2}\in S. \tag{1}\]  
(2) Convex Function: If the domain of the function \(f(x)\) is a convex set, and for any two points \(x_{1},x_{2}\) and any parameter \(t\in[0,1]\) that lies between them, Equation (2) is satisfied, then \(f(x)\) is called a convex function.  
\[f(tx_{1}+(1-t)x_{2})\leq tf(x_{1})+(1-t)f(x_{2}). \tag{2}\]  
(3) Gradient: The rate of change of a scalar function at a particular point. It is a vector, where each component is the partial derivative of the function in the corresponding coordinate direction. The function value rises rapidly in the direction of the gradient; hence, gradient information is often used to guide the search direction and step size in optimization.  
For a univariate function \(f(x)\), its gradient is a scalar, denoted as \(f^{\prime}(x)\).  
For a multivariate function \(f(\mathbf{x})\), its gradient is a vector, that is, the following:  
\[\
abla f(\mathbf{x})=\bigg{(}\frac{\partial f}{\partial x_{1}}\frac{\partial f }{\partial x_{2}}\vdots\frac{\partial f}{\partial x_{n}}\bigg{)}, \tag{3}\]  
where \(\frac{\partial f}{\partial x_{1}}\) represents the partial derivative of the function \(f\) with respect to the variable \(x_{i}\).  
(4) Hessian Matrix: It describes the second-order partial derivative information of a scalar function and is a second-order tensor. It describes the local curvature and shape of the function at a certain point. For an \(n\)-dimensional function \(f(\mathbf{x})\), its Hessian matrix \(\mathbf{H}(\mathbf{x})\) is an \(n\times n\) matrix, where the element in the \(i\)-th row and \(j\)-th column is \(\frac{\partial^{2}f(\mathbf{x})}{\partial x_{i}\partial x_{j}}\). The determinant and eigenvalues of the Hessian matrix can be used to determine the nature of the local extremum and inflection points of the function, such as whether it is a local minimum or a saddle point. If \(\mathbf{H}(\mathbf{x})\) is positive definite, then the function \(f(\mathbf{x})\) has a local minimum at \(\mathbf{x}\). In optimization, the Hessian matrix is also used to guide the search direction and step size; for example, [PERSON]'s method is an optimization algorithm that utilizes the Hessian matrix information.
## 2 Methodology
### Manufacture of LWAs from Wastes
#### 2.1.2 Manufacture of LWAs  
The LWA manufacturing process was carried out following the working protocol published in previous studies by this same research group [45; 46]. Mixtures of clay and organic residue were prepared in percentages of 97.5% and 2.5%, respectively. The proportion of organic residue used is based on the authors' previous experience with this type of high-carbon waste [45]. Thus, once the raw material mixture was prepared in the indicated proportion, the appropriate moisture content was added, and after 24 h in resting conditions, the mixture was extruded using a Nannetti(r) laboratory pneumatic extruder, obtaining thin cylinders of 8-10 mm in diameter. The extruded material was cut and shaped into spherical pellets of approximately 10.2 mm in diameter. They were then dried for 24 h at room temperature, and then dried in an oven at 105 \({}^{\circ}\)C for 24 h. Once dried, the pellets obtained were fired in a [PERSON](r) TOR-R 120-14 rotary tubular kiln with a rotation speed of 2.5 rpm, using the following protocol: 1 or 2 min in the preheating zone of the furnace at a temperature between 600 and 800 \({}^{\circ}\)C, an intermediate step necessary to prevent the material from bursting, and 4 min in the central zone of the furnace at the maximum firing temperature. This maximum temperature was determined for each mixture according to [PERSON] et al. (2019) [45; 46]: the maximum temperature that the material can reach without melting or sticking to the kiln tube or other pellets. In this way, the maximum expansion that the initial pellet can undergo when transformed into LWA can be observed.  
The added wastes not only play a crucial role in the bloating process of the aggregate, but due to their organic character, they also have significant calorific value. This is advantageous from energy and environmental perspectives. On the one hand, the combustion of the organic waste will bring heat to the process, which means less fuel consumption during the firing of the aggregates. On the other hand, and directly related to this reduction, there will be a decrease in greenhouse gas emissions. Both aspects will provide an environmental benefit that will be reflected in the LCA of the materials manufactured. Table 1 shows the gross and net calorific values of the waste used in this work, determined according to standard EN 14918 [47].  
\begin{table}
\begin{tabular}{c c c} \hline
**Waste** & **GCV (kJ/kg)** & **NCV (kJ/kg)** \\ \hline AHS & 19,005.9 & 17,763.6 \\ \hline PS & 12,901.7 & 11,836.9 \\ \hline CP & 29,096.3 & 27,340.5 \\ \hline CG & 20,961.8 & 19,463.8 \\ \hline \end{tabular}
\end{table}
Table 1: Gross and net calorific values of wastes (GCV = gross calorific value; NCV = net calorific value).  
In total, we worked with 15 types of samples grouped into 5 different scenarios: a first scenario corresponding to aggregates obtained exclusively from clay and the remaining four depending on the organic additive used. Table 2 shows the firing conditions for each of the working samples.
# Beam Formation and Vernier Steering Off of a Rough Surface
## 3 Non-Mechanical Beam Steering  
### Materials and Methods  
Non-mechanical beam steering exploited the Fourier transform relationships inherent to the focal plane geometry of the optical setup in order to create a phase tilt at the scatterer. The field at the focal plane of a lens is a coordinate-scaled Fourier transform of the wave incident on the lens [26]. For some function \(g(x)\) that has a Fourier transform \(\mathcal{F}[g(x)]\), the shift theorem of Fourier transforms states that  
\[\mathcal{F}[g(x-\Delta x)]=\mathcal{F}[g(x)]\exp[-i2\pi(f_{x}\Delta x)], \tag{2}\]  
where \(\Delta x\) is the size of the shift. Simulations have shown that circularly shifting the SLM phase mask approximates the required shift needed to create phase tilts at the scatterer for small shifts [21]. However, these shifts vacate the optimized phase mask from the SLM and leave behind unoptimized pixels. Therefore, there is a maximum distance the SLM phase mask can be shifted before the entire SLM is unoptimized. A circular shift was chosen because it reuses the portion of the optimized SLM phase mask that is shifted off of the boundary of the SLM and places them in the vacated pixels. This is advantageous because the vacated pixels would otherwise contribute to background speckle but are instead optimized to focus the light toward a secondary spot. Because of the nature of circular  
Figure 2: Enhancement achieved using different techniques for reflective inverse diffusion. In (**a**), the performance on 600 grit polished nickel is shown. In (**b**) the performance on zinc oxide white paint is shown.  
shifts, this is also disadvantageous because the secondary spot will be equally optimized with the desired spot when the SLM phase mask is circularly shifted by 50%, after which it is more optimized. Figure 3 shows additional simulated data demonstrating the creation of phase tilts at the scatterer's surface that are superimposed over the wavefront-shaped field due to circular spatial shifts of the SLM's phase mask. The slope \(m\) of the phase tilts at the scatterer can be derived from Equation (2). Extracting the slope from the phase tilt term in Equation (2) and applying appropriate coordinate transformations from Fourier optics,  
\[\begin{split} m&=-\frac{2\pi}{\lambda f}\Delta x \quad\left(\frac{radians}{m}\right);\\ &=-\frac{\Delta x}{f}\quad\left(unitless\right),\end{split} \tag{3}\]  
where f is the focal length of \(L_{1}\) and \(\lambda\) is the wavelength. The angle of this tilt, which shall be denoted \(\theta_{scan}\), is given in Equation (4) as  
\[\theta_{scan}=\tan^{-1}(m). \tag{4}\]
# Adapting Probabilistic Flooding in Energy Harvesting Wireless Sensor Networks
## 6 Performance Evaluation  
A simulation program in C++ has been developed to evaluate RPF against PF in _geometric random graph_ (GRG) [64] topologies. At each timestep, the simulator checks whether a node has any packet to send to its neighbors and takes over the transmission. When the energy harvesting environment is activated, the simulator checks whether the receiver node is operating before transmitting the packet to it. If the receiver node is not operating, the sender node is informed and the packet is queued for transmission at next timestep. The number of nodes is \(n=1000\) for all simulation scenarios and they are independent identically distributed in \([0,1]\times[0,1]\) plane. A link between any pair exists if their euclidean distance is equal or smaller than the _connectivity radius_\(r_{c}\).
## 2 Instrumentation and Methods  
### Site Description  
This study was carried out on a conifer plantation at Qianyanzhou Subtropical Forest Ecosystem Research Station, Chinese Academy of Sciences (Qianyanzhou Station for short) in Taieh County, Jiangxi Province in subtropical China (26\({}^{\circ}\)44\({}^{\prime}\)48\({}^{\prime\prime}\) N, 115\({}^{\circ}\)04\({}^{\prime}\)13\({}^{\prime\prime}\) E, 110.8 m). The main tree species are _Pinus masssoniana_, _Pinus elliotiti_, _Cunningham laancelata_ and some broadleaf trees, with coverages of 42.0%, 49.6%, 5.8% and 2.6% of this landscape, respectively. These trees were planted in 1985. The leaf area index is 3.6 m\({}^{2}\) m\({}^{-2}\)[56]. The average canopy height is 18 m. The mean slope of this study region is 2.8-13.5\({}^{\circ}\). The shrubs are mainly _Loropetulum chinese_, _Adinandra millettii_ and _Lyonia compta_[35]. The mean annual precipitation is 1485.1 mm, and the annual temperature is 17.9 \({}^{\circ}\)C [57]. The annual quantity of global solar radiation was 4579 MJ m\({}^{-2}\) in 2013 and 4496 MJ m\({}^{-2}\) in 2014, and the annual quantity of photosynthetically active radiation (PAR) was 7998 mol m\({}^{-2}\) in 2013 and 7656 mol m\({}^{-2}\) in 2014 [35]. Most of the atmosphere at the Qianyanzhou site had high GLP loads, i.e., most S/Q (S and Q are diffuse and global solar radiation, respectively) values were larger than 0.5, and their hourly averages from May 2013-December 2016 were 0.85 (S/Q = 0-1, sample point \(n\) = 14,748), 0.38 (S/Q < 0.5, \(n\) = 91) and 0.76 (S/Q \(\geq\) 0.5, \(n\) = 985).
## A Self-Optimizing Scheme for Energy Balanced Routing in Wireless Sensor Networks Using SensorAnt  
**[PERSON] *, [PERSON], [PERSON] and [PERSON]**  
Department of Computer and Communication Systems Engineering, Universiti Putra Malaysia,  
43400 UPM Serdang, Selangor, Malaysia; E-Mails: [PERSON]_ADDRESS] (B.M.A.);  
[PERSON]_ADDRESS] (M.F.A.R.); [PERSON]_ADDRESS] (A.I.)  
* Author to whom correspondence should be addressed; E-Mail: [PERSON]SS].  
_Received: 7 June 2012; in revised form: 23 July 2012 / Accepted: 3 August 2012 / Published: 15 August 2012_  
**Abstract:** Planning of energy-efficient protocols is critical for Wireless Sensor Networks (WSNs) because of the constraints on the sensor nodes' energy. The routing protocol should be able to provide uniform power dissipation during transmission to the sink node. In this paper, we present a self-optimization scheme for WSNs which is able to utilize and optimize the sensor nodes' resources, especially the batteries, to achieve balanced energy consumption across all sensor nodes. This method is based on the Ant Colony Optimization (ACO) metaheuristic which is adopted to enhance the paths with the best quality function. The assessment of this function depends on multi-criteria metrics such as the minimum residual battery power, hop count and average energy of both route and network. This method also distributes the traffic load of sensor nodes throughout the WSN leading to reduced energy usage, extended network life time and reduced packet loss. Simulation results show that our scheme performs much better than the Energy Efficient Ant-Based Routing (EEABR) in terms of energy consumption, balancing and efficiency.  
**Keywords:** energy balancing; energy consumption; ant colony; battery lifetime; WSNs
# Hyperledger Fabric Access Control for Industrial Internet of Things
###### Abstract  
The Industrial Internet of Things (IIoT) plays an important role in Industry 4.0, but the existing IIoT systems could be vulnerable to a single point of failure and malicious attacks, failing to provide reliable services. IIoT devices have some particularities, such as mobility, limited performance, and distributed deployment, which are challenging to traditional centralized access control methods in the large-scale IIoT environment. To resolve the challenges, we propose an access control system for the Industrial Internet of Things. The system contains three smart contracts: device contract (DC), policy contract (PC), and access contract (AC). The device contract provides a method of storing the URL of the resource data generated by the equipment and a query method. The policy contract provides the function of managing the attribute-based access control (ABAC) of the administrator user. The access contract is the core program that implements the access control method for ordinary users. Combining ABAC and blockchain technology provides decentralized, fine-grained, and dynamic access control management for IIoT.  
industrial internet of things; blockchain; hyperledger; smart contract; access control +
Footnote †: journal: Applied Sciences