esa-sceva/satcom-chunk-collection huggingface dataset:
## 6 Implementation and Case Study
### Expanded Discussion of Robustness Analysis (Section 7.5)  
The robustness analysis was extended to discuss timing-related trade-offs. Although the current framework meets the Near-RT latency requirements, scaling the system to larger networks comprising over 100 Distributed Units (DUs) may necessitate the deployment of distributed aggregation servers to mitigate potential bottlenecks in the aggregation phase. Additionally, while the 4.8 s convergence time is deemed acceptable for Non-Real-Time RIC policy orchestration, further optimizations will be required to accommodate dynamic scenarios such as rapid handovers or emergency call prioritization.  
* **Input Features**: 5 min historical window of
* Traffic load (normalized 0-1).
* PRB utilization (\(\|\mathbf{u}\|_{2}\leq 3.0\)).
* RSRP measurements (dBm).
* **Output**: Sleep duration prediction (ms) with \(\varepsilon=2.0\) DP guarantee.
* **Hidden Layers**: 128 LSTM units, dropout rate = 0.2.  
**Enhanced Simulation Scenarios:** The simulation environment was enriched to emulate more challenging and realistic network conditions. A high-load scenario was introduced by simulating peak-hour traffic with 80-100% PRB utilization, leveraging the DAWN dataset's emergency scenario traces to reflect congestion patterns. To capture bursty traffic conditions, the environment incorporated Poisson-distributed traffic spikes with a rate of five spikes per minute, resulting in traffic surges of up to 200%. Additionally, the simulation accounted for heterogeneous slice requirements by conducting separate analyses for different service types, including enhanced Mobile Broadband (eMBB) with a 100 Mbps target throughput, Ultra-Reliable Low-Latency Communications (URLLCs) with a strict 1 ms latency budget, and massive Machine-Type Communications (mMTCs) supporting a device density of 10,000 devices per square kilometer. User mobility was also modeled by integrating SUMO-generated vehicular traces simulating speeds of 60 km/h, combined with the 3 GPP 38.901 UMa pathloss model to reflect realistic radio propagation effects. Under these enhanced scenarios, the proposed model achieved 32% energy savings while maintaining less than 5% latency degradation compared to always-on baselines.
## 2 Approach to Fuel-Cell System Analysis
### Summary of Main Assumptions  
Considering the information and discussion included in the previous points, the main assumptions in the study are summarized below:  
* For all operating conditions, the sensitivity of the fuel cell stack polarization curve with respect to the oxygen molar fraction is assumed to be equal to the data obtained from the study of [PERSON] et al. [26].
* The hydrogen consumption is directly calculated from the anode reaction stoichiometry. At the cathode, the total oxygen mass flow is the same regardless the oxygen molar fraction achieved, while this value is adapted as a function of the current density assuming a constant oxygen excess factor.
* The separation membrane operates at a constant temperature of 80 \({}^{\circ}\)C and pressure ratio (nominally, four). The ratio of inlet to permeate (O\({}_{2}\)-enriched) mass flows (stage cut) is extracted from the operating map of a commercial system (model NM C05 of the UBE Corporation, Tokyo, Japan).
* In the reentate flow (nitrogen-enriched), a pressure drop of 5% is assumed for all working conditions. This stream is directed to an electric turbine, characterized by a constant isentropic efficiency. Instead, in the permeate (oxygen-enriched) stream, the outlet pressure is assumed to be equal to 1 bar. For this reason, the operation of the oxygen-enriched concept was compared to an atmospheric fuel cell, also working with 1 bar at the cathode inlet, so that the pressure effect on the fuel cell stack performance is equivalent.
* In order to reach the necessary pressure upstream of the separation membrane, a two-stage boosting system with intermediate cooling is used. A cooling efficiency of 90% is assumed for this intermediate cooling.
* The hydrogen stream is assumed to be provided at 5 bar, controlled by an expansion valve at the hydrogen tank outlet. This stream is heated using the energy available in the cathode stream after compression, increasing the exergy available in the flow. Afterword, the 5-bar heated hydrogen stream is directed to a turbine included in a turbocharger, providing the power for the first compression in the cathode stream with a mechanical efficiency of 97%. Instead, the second compression is directly driven by an electrical compressor, representing the main energy consumption in the proposed system.
* The isentropic efficiency of each compressor stage is assumed to be equal and independent on the working conditions. In the same sense, both nitrogen and hydrogen turbine efficiencies are also constant and equal. The selected ranges for turbine and compressor efficiencies were extracted from the typical values of the radial turbomachinery currently used in automotive applications in the peak efficiency area.
# Energy Reduction Multipath Routing Protocol for MANET Using Recoil Technique
## 3 Proposed Protocol (AOMDV-ER)  
Some recently proposed algorithms, namely AOMR-LM, FF-AOMDV [3] and AOMDV, have some shortcomings. The AOMDV and AOMR-LM have the least end to end delay and consumption of energy but demonstrated the worst performance in packet delay ratio. Whereas the other protocol FF-AOMDV addressed the problem encountered in the AOMR-LM protocols, but could not resolve the problem of network lifetime [3]. These algorithms did not consider the node battery level evaluation and link strength estimation before making them (nodes) as the part of the route. However, the proposed algorithm AOMDV-ER has given due weight to this parameter.  
The Energy Reduction Multipath Routing Protocol for MANET using Recoil Technique (AOMDV-ER), is the improvement over the well-known ad hoc on demand distance vector routing (AODV), and ad hoc on demand multipath distance vector routing AOMDV, AOMR-LM and FF-AOMDV. The proposed routing consists of three optimized algorithms via Optimal route discovery; coordinated recoiled node algorithm, to reduce the further reduction in battery power; and the last algorithm takes care of the route maintenance efficiently, to reduce the chances of retransmission, which is an important provision for saving the energy. The description is expressed in the subsequent section.
## 3 Safety Analysis and Environmental Modeling
### Setting Safe Water Depths  
When planning the route, it is necessary to avoid crossing particular areas, such as military exercise areas, anchoring areas, and no-go areas, and to determine safe water depths to prevent grounding. When setting safety contours, the USV's draft and Under-Keel Clearance must be considered, and reasonable values must be determined based on the ship's conditions, water characteristics, and voyage requirements. Determining the minimum safe water depths for USV navigation is a complex process that comprehensively considers factors such as USV parameters, underwater equipment location, maneuverability, and sea conditions. Figure 9 shows a schematic diagram of the minimum safe water depths, and the final safe water depth is given by Equation (6).  
\[H_{\text{min}}=D+\frac{1}{2}H_{w}+C \tag{13}\]  
where \(D\) is the draft depth of the USV, \(H_{w}\) is the wave height, and \(C\) is the draft safety margin of the USV.  
This study utilizes the \"Xin Hong Zhuan\" from Dalian Maritime University as an example, which has a design draft of 3.5 m. Determining adequate clearance depth is influenced by various factors, such as navigational environment uncertainties and the reliability of ship equipment. To ensure safe navigation, it is essential to have a sufficient safety margin to cope with uncertainties and avoid being overly conservative in fully utilizing water resources. Generally, the surplus depth is determined through empirical values, analytical formulas, semi-empirical formulas, and ship squat tests [37]. This study's surplus depth is set at 1 m based on empirical values. The average wave height along the coast within the study area ranges from 0.2 m to 0.7 m, with a design wave height of 0.7 m for this experiment. Incorporating these values into Equation (6) establishes a safety contour depth of 5.2 m for this experiment. This paper further extracts and reclassifies bathymetric data based on minimum safety depth requirements and constructs depth contours. Areas with depths greater than 5.2 m are designated as navigable zones, while regions shallower than 5.2 m are marked as shallow water navigation hazards. Depth processing is illustrated in Figure 10. Doing so creates a grid map of navigable and hazardous areas for the research maritime area, effectively preventing the designed navigation route from crossing shallow points and ensuring navigational safety.  
Figure 9: Schematic diagram of minimum safe water depths.
## 3 Fundamentals of GLI-Split
### GLI-Addressing  
GLI-Split encodes ID and locator information in IPv6 addresses to be compatible with classic IPv6. The ID of a GLI-address is fixed, while the locator information can be replaced by GLI-hosts  
Figure 1: GLI-nodes and GLI-gateways have an identifier (ID) for identification and a local locator (LL) for routing in edge networks; in addition, GLI-gateways have a global locator (GL) which is used for routing in the IPv6 backbone.  
and gateways on the path between source and destination. According to the included locator, we distinguish three types of addresses: identifier addresses, local addresses, and global addresses.  
Transport layer protocols like TCP use source and destination IP addresses to map packets to flows. During an ongoing transport connection, these elements must not change; otherwise, packets cannot be mapped correctly to the existing connection. An _identifier address_ is an endpoint identifier, independent of any locator information, which is used in the transport layer of upgraded GLI-nodes. This guarantees that regardless of the current location of the upgraded GLI-node, the transport layer sees the same address. On the network layer, locator addresses are used to encode the current location. An upgraded GLI-node translates between both address types when handing data up or down the protocol stack. This principle is called vertical address translation and illustrated in Figure 2. Depending on the scope of the locator address, we distinguish between two different types. A _local address_ is used for forwarding within a GLI-domain. As the local locator has only site-local meaning, a local address must never leave a GLI-domain. To ensure this requirement, a responsible GLI-gateway at the border of the host's GLI-domain translates between local addresses and global addresses. This property is called horizontal address translation and can also be seen in Figure 2.  
A _global address_ is mainly used for routing outside GLI-domains. The global locator belongs to a GLI-gateway of the host's GLI-domain and is allocated from the address space of the ISP that is connecting the GLI-domain to the Internet.  
Inside a GLI-domain, packets addressed to global addresses are usually forwarded to a default gateway. However, if the global locator in the destination address belongs to a GLI-gateway of the same GLI-domain, the packet is routed to that GLI-gateway.
## 1 Introduction
In [9], the antenna is a planar device composed of a single-sided printed circuit board that concurrently emits the linear polarization of an RFID and a mobile phone band and the circular polarization of a GPS band. Another proposal for a circular polarization antenna aims to cover all Global Navigation Satellite Systems, including GPS in L1 and L2 bands, GLONASS, Galileo, and BeiDou. It also has a highly effective structure for SDARS satellite broadcasting [10]. This passive structure's design, with its overall dimensions of \(43\times 104\times 14.5\) mm\({}^{3}\), allows for simple integration into various mounting points in the car. In [11], a single-feed GPS antenna was introduced with enhanced multipath rejection. The antenna was built on a shorted annular elliptical patch. A device with two different GNSS (Global Navigation Satellite Systems) antennas was presented in [13]. The gadget has two antennas: a GNSS PCB (printed circuit board) inverted-F antenna on top and a GNSS ceramic patch antenna on the device's bottom. The conclusions reached are that the patch is generally the best option if the device is static and able to point to the sky. However, the inverted-F antenna in the device is preferred for random orientations of the device. However, there was little discussion compared to [4], and the common belief is that an RHCP antenna for an IoT device is always the best choice. However, what happens when the IoT device with an embedded antenna is not pointing to the sky? What happens if the device is on a seat of a vehicle? What is the performance of both the RHCP patch antenna and antenna booster if the device is upside-down? Does the radiation pattern of a microstrip patch antenna, typically directive, become worse than a quasi-isotropic linearly polarized antenna booster when the orientation of the device is not known, or even worse, cannot be controlled? Consequently, a comparison of circularly polarized microstrip patch antennas and linear-polarized antenna boosters was conducted to determine the performance, depending on the position and orientation of the IoT device inside a vehicle. There are different antenna designs when creating a GPS microstrip patch antenna [14; 15; 16; 17; 18; 19; 20]. Some consist of a single layer patch antenna, one or two feeding points as well as modifying the geometry to generate two degenerated out-of-phase orthogonal modes to radiate an RHCP electromagnetic wave. The rest of this paper is divided as follows. Section 2 describes all the resources used to conduct the research. Section 3 describes the steps taken to gather all data required for the study. Section 4 demonstrates the results of the procedure. Section 5 discusses some representative cases of IoT devices. Section 6 presents the conclusions.
## 3 Methodology
### Proposed SOCC Caching Scheme
```
0:\(n\) is the current node and \(c\) is any content arrived along the path if\((c\
otin\mathcal{B}_{n}\) and \((\text{Requester}(r_{c})==n)\)then\(\triangleright\)\(c\) not available in the local cache \(\triangleright\)\(c\) not available in the local cache and node \(n\) is the requester if\((\mathcal{B}_{n}<\mathcal{B})\)then\(\triangleright\) Insert \(c\) in \(\mathcal{B}_{n}\) elseif\((\mathcal{B}_{n}==\mathcal{B})\)then\(\triangleright\) Replace least recently used content and insert the arrived \(c\) in \(\mathcal{B}_{n}\) endif endif Forwarded to the neighbor nodes in order to reach the Requester
```  
**Algorithm 2** The proposed Placement scheme \(SOCC\) at the arrival of \(c\)  
Upon the arrival of data packet at the node A, first of all, node A checks its own \(\mathcal{B}\) whether arrived content is already available it discards the arrived content \(c\), otherwise if the arrived \((c\
otin\mathcal{B}_{n})\) is not available then it decides whether to cache the new content \(c\) in its \(\mathcal{B}\). Consider the cache \(\mathcal{B}\) of node A is full and can not cache the arrived \(c\). In such case, to cache the arrived content \(c\), the Algorithm 2 used the LRU replacement strategy to remove the oldest content from node A cache and makes space for new content \(c\). The complexity of the proposed scheme is similar to that of LRU, only more storage is required for maintaining the convergence table SOCC. The flowchart of the proposed approach is shown in Figure 3.
## 2 Heat-to-Power Applications
### Supercritical CO\({}_{2}\) Brayton Cycles  
A Brayton cycle can be implemented with working fluids such as carbone dioxide (CO\({}_{2}\)), air, helium (He), ethane (C2H4), sulphur hexafluoride (SF6), xenon (Xe), methane (CH4) and nitrogen (N2). The standard configuration can be modified to give birth to other layouts with the aim of increasing the cycle efficiency. More than a dozen layouts have been investigated so far throughout the literature [54; 55; 56; 57; 58; 59]: standard Brayton, pre-compression, recompression, split expansion, partial cooling, cascade, simple reheat, double reheat, etc. These architectures are meant to be applied for power generation from various heat sources including coal combustion, thermonuclear reaction, solar radiation harvesting and waste heat recovery [49; 60].  
[PERSON] and [PERSON] [61] investigated the possibility of applying Brayton cycles for heat recovery in coal power plants. Several possibilities with supercritical carbon dioxide were screened of which the recompression cycle emerged as the best option with an efficiency increase of about 4.5%pt in comparison with the standard Brayton cycle.  
Concentrating solar power developers are also seeking for competitive designs, and efficiency increase through Brayton cycle have been proposed. [PERSON] et al. [62] investigated Brayton cycles for line-focusing solar power plants with various working fluids. [PERSON] and [PERSON] [63] argue that replacing steam Rankine by sCO\({}_{2}\) Brayton in tower plants has many benefits: compactness, modularity and efficiency. [PERSON] and [PERSON] [64] compared several options for solar power, and Brayton appeared as a promising option but is yet to be confirmed by demo plants.  
The Brayton cycle is being intensely investigated and attracts a lot of interest in the nuclear industry for use in the fourth generation nuclear power reactors [54; 65; 66; 67]: sodium-cooled fast reactor, lead-cooled fast reactor, gas-cooled fast reactor, super-critical water-cooled reactor, very high temperature gas-cooled reactor and molten salt reactor. It could be well adapted for temperature in the range of 500-600 \({}^{\circ}\)C, with efficiency around 50%.  
Brayton cycle performance is affected by several factors including the turbine inlet temperature and the pressure ratio. Performance may vary also depending upon the cycle architecture, and the recompression cycle was proposed as a suitable option for maximum cycle temperature around 500-600 \({}^{\circ}\)C, pre-compression and partial cooling being the right choices for processes over 600 \({}^{\circ}\)C.
# Closed-Form Solution of the Bending Two-Phase Integral Model of Euler-Bernoulli Nanobeams
## 3 Closed-Form Solution of [PERSON]'s Two-Phase Integral Model Equations  
In a right-handed coordinate system, consider a uniform beam of length \(L\) and cross-sectional area \(S\) whose longitudinal axis coincides with the \(x\)-axis and with one end at \(x=0\) and the other at \(x=L\). The beam is loaded by a transverse distributed load \(q(x)\) at the top in the \(z\)-direction.  
Under the Euler-Bernoulli assumptions and for a homogeneous and isotropic material, the transverse displacement in the \(z\)-direction (deflection) \(w(x)\) is a function of \(x\), and the strain in the \(x\)-direction is defined by  
\[\varepsilon_{x}(x)=-z\frac{d^{2}w(x)}{dx^{2}}\]  
In the two-phase nonlocal [PERSON]'s elasticity model, the stress \(\sigma_{x}(x)\) is defined through the constitutive relation  
\[\sigma_{x}(x)=E\Big{(}\xi_{1}\varepsilon_{x}(x)+\xi_{2}\int_{0}^{L}k(x,t) \varepsilon_{x}(t)dt\Big{)},\]  
and the corresponding bending moment is defined by  
\[M(x)=\int_{S}\sigma_{x}(x)zdS=-EI\bigg{(}\xi_{1}\frac{d^{2}w(x)}{dx^{2}}+\xi_{ 2}\int_{0}^{L}k(x,t)\frac{d^{2}w(t)}{dt^{2}}dt\bigg{)}, \tag{14}\]  
where \(E\) is the elasticity modulus (constant) and \(I=\int_{S}z^{2}dS\) is the second moment of area. The parameters \(\xi_{1}>0\), \(\xi_{2}>0\) and \(\xi_{1}+\xi_{2}=1\) regulate the contribution from the local (classical) and nonlocal model, respectively. The kernel or attenuation function \(k(x,t)\) determines the nonlocal effect of the strain \(\varepsilon_{x}(t)\) at the source point \(t\) on the stress \(\sigma_{x}(x)\) at the receiver point \(x\). There are many possible kernel functions \(k(x,t)\). The most commonly used is the Helmholtz-type kernel  
\[k(x,t)=\frac{1}{2\tau}e^{-\frac{|x-t|}{\tau}},\quad x,t\in[0,L], \tag{15}\]  
where the parameter \(\tau=\frac{\epsilon_{0}a}{\ell}\), \(\epsilon_{0}\) is a material constant, \(a\) is an internal characteristic length (e.g., lattice parameter, granular distance), and \(\ell\) is an external characteristic length (e.g., the crack length, the wave length). The kernel \(k(x,t)\) is a positive function which diminishes  
specified at each of the two ends of the beam at \(x=0\) and \(x=L\).  
Next, we look at the four most common cases of boundary conditions with practical interest. In each case, we formulate the corresponding boundary value problem in operator form and decomposed it in two lower-order problems, namely a second-order differential boundary value problem (DBVP) and a second-order Fredholm integro-differential boundary value problem (FIDBVP). The solution is obtained by first solving the DBVP in closed form and then the FIDBVP.  
For convolution kernels of the type (15), the FIDBVP is converted to a Volterra-Fredholm integro-differential boundary value problem (VFIDBVP), which is then solved by using Theorem 1.
# Free Space Optic Receiver with Strongly Overlapped Photodetectors' Field of View
## 1 Introduction  
The goal of this study was to design a mobile free space optic (FSO) multiple photodetector receiver optimized for highest sensitivity and communication radius. The mobile FSO receiver has no fixed position or fixed distance between the optical transmitter and the receiver. There is also no fixed angle between the main lobes of a transmitter's and receiver's components. All these factors complicate noise optimization [1]. An ideal mobile optical receiver responds to signals coming from an entire sphere. Assuming that the transmitter is above the receiver, the spatial angle might be reduced to half, i.e., one hemisphere, 2\(\pi\) sr. The receiver will be still sensitive to noise from the whole hemisphere, whereas the useful signal might only come from a part of it. An outdoor environment without reflections serves as a typical example. Interiors, however, offer much better receiving conditions due to numerous reflections, and all directions detection capability is beneficial. Similarly, scattering of ultraviolet light improves the receiving conditions, even in open space [2; 3; 4]. Therefore, the receiver should be designed with regard to the planned environmental conditions and spectral characteristics of the light to be used.