esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction
As an example, a space-borne NIR DASH interferometer (weighing 1 kg) was mounted in this way. It was clamped by a combination of four bonding surfaces (the diameter of each bonding area was 13 mm) and four-pad elastic compression. The (metal-to-glass) bonding surface tension broke during the vibration testing at the instrument level because of the lower natural frequency of 800 Hz. Therefore, the design was limited to mounting a normalized DASH interferometer. To support large optical components, an adhesive structure was mainly used on the side to support large transmission and reflection prisms [15; 16; 17; 18]; however, this cannot be directly used to support an interferometer prism. To overcome some of the limitations of the existing approaches, a novel and flexible structure optimization method that implemented a non-common-path NIR DASH interferometer used in a space-borne wind instrument is proposed in this study. With the mechanical stress of the flexible structure and shear stress at the bonding surface as the optimization goal, the stable rigid structural frame was optimized, and the optimization design was carried out from the parameters of the flexible structure to achieve mechanical stability and low heat conduction support in the DASH interferometer. The spring constants were optimized to minimize the stress. The results from FEA and vibration tests agreed with the model calculation results. Compared with existing methods, the proposed flexible support can reduce heat conduction and satisfy the requirements of the launch environment. Table 1 lists existing approaches and the proposed flexible structure for mounting the interferometer.
## 3 Design Method of Replacing Top-Coal Caving Hydraulic Supports with Backfilling Hydraulic Supports
### Stress Analysis of the Top-Coal Caving Hydraulic Support  
The stress analysis of the existing top-coal caving hydraulic support should be carried out to clarify the mechanical and structural characteristics of the existing support before reforming each component in a targeted manner.  
The main bearing component of the top-coal caving hydraulic support is the top beam, so the top beam is used for the stress analysis. During the advancement of the working face, the load distribution on the top beam changes constantly, so the overlying load is generally simplified as a uniform load or a triangular load in the stress analysis of the hydraulic support. The work simplified the overburden load as a uniform load (Figure 5). Points A and B are the constraints of the front and rear columns on the top beam, respectively; \(F_{1}\) and \(F_{2}\) the support stress of the front and rear columns, respectively; \(f\) is the friction force on the top beam; \(q\) the load on the top beam; point O the front endpoint of the top beam, with a reference system established for the top beam.  
The equation is constructed from the equilibrium state of the support.  
If the resultant moment at point \(O\) is zero.  
\[\begin{array}{c}\sum M_{o}=0\\ \cos\alpha F_{1}l_{1}+\cos\beta F_{2}(l_{1}+l_{2})-\frac{q}{2}(l_{1}+l_{2}+l_ {3})^{2}=0\end{array} \tag{1}\]  
If the resultant force in the \(x\) direction is zero.  
\[\begin{array}{c}\sum F_{x}=0\\ -\sin\alpha F_{1}+\sin\beta F_{2}+f=0\end{array} \tag{2}\]  
If the resultant force in the \(y\) direction is zero.  
\[\begin{array}{c}\sum F_{y}=0\\ \cos\alpha F_{1}+\cos\beta F_{2}-q(l_{1}+l_{2}+l_{3})=0\end{array} \tag{3}\]  
The dimensions of the top beam of the ZFSS600/16/32 top-coal caving hydraulic support are as follows: \(l_{1}=0.5\), \(l_{2}=0.98\), \(l_{3}=0.51\). When the support height is at 1600-3200 mm, the support state at the height of 2.5 m is taken to solve the load. Corresponding column-angle parameters are as follows: \(a=5^{\circ}\), \(\beta=2^{\circ}\). Then,  
\[\begin{array}{c}F_{1}=0.99q\\ F_{2}=1.01q\\ f=-0.12q\end{array} \tag{4}\]  
The load ratio of the front and rear columns is \(F_{1}\):\(F_{2}\) = 0.98:1. The stress of front and rear columns is not much different under the uniform load, and the load-bearing capacity  
Figure 5: Mechanical model of the top beam of the top-coal caving hydraulic support.  
of the rear column is 2% larger than that of the front column. The main structures such as the top beam of the top-coal caving hydraulic support can be used. Considering that the top beam needs to support the backfilling space, it is necessary to strengthen the support function of the rear column based on the top-coal caving support.
## 1 Introduction  
In recent years, orthodontics has increasingly focused its interest on temporary anchorage devices (TADs) through orthodontic micro-screws. TADs are widely used in orthodontic therapy due to their feasibility in managing vertical control, sagittal tooth movement, maxillary suture expansion, midline correction, etc. [1, 2]. Compared with conventional methods, the high versatility, comfort and easy handling of micro-screws have seen an increase in their use [3]. Orthodontic micro-screws have been manufactured both in titanium and stainless steel alloy; however, stainless steel alloy has been widely recommended because the material alloy does not influence the success rate of orthodontic micro-screws, nor the efficiency, and stainless steel alloy has a lower cost than titanium alloys [4]. Indeed, self-tapping and self-drilling micro-screws are mainly used as TADs thanks to their reported short- and long-term success rates compared to conventional methods in the maxillary buccal area. However, the placement of self-drilling orthodontic micro-screws has been reported to show greater accuracy between interproximal denotals, which might be explained by the way in which manual insertion allows the clinician to relocalise the direction during self-drilling and subsequent micro-screw placement [5]. Self-tapping orthodontic micro-screws require a pre-drilled hole before inserting a larger micro-screw. This process might increase inaccuracy and potentially risk root perforation [6]. Micro-screws are usually placed in maxillary buccal insertion sites, mainly between the maxillary first molars and second premolars, because this allows a simple and effective technique for managing premolar extraction cases, which also shows a high success rate (90.3%) [7]. In contrast, mandible insertion sites have a lower success rate due to the higher bone density of the mandible that might require the use of self-tapping orthodontic micro-screws to penetrate the cortical bone [8; 9]. [PERSON] et al. [10] reported a 13.5% failure rate related to the micro-screw placement parameters [11; 12], type of tooth movement [13; 14], anatomical location [1] and the inherent characteristics of the micro-screw itself. In addition, operator inexperience regarding the accuracy and outcome of micro-screw placement remains a concern.  
The aim of this work is to analyze and compare the accuracy of micro-screw placement depending on the experience of the operator. The null hypothesis (H\({}_{0}\)) states that there is no difference between the operator's experience regarding the accuracy of micro-screw placement and intraoperative complications.
# Multi-Objective Ship Route Optimisation Using Estimation of Distribution Algorithm
## 4 Proposed Solution
### The Search Algorithm
Output:\(\widetilde{\mathcal{PS}}\)--(good) approximation of the set of Pareto optimal control input sequences (see Equation (5))
1\(\widetilde{\mathcal{PS}}\leftarrow\emptyset\)\(\mathcal{S}_{\text{\tiny{ocp}}}\leftarrow\emptyset\)// the paths obtained from pgmc and already evaluated initialise(pgmc)// initialise the path generator--pgmc
2 forstep\(s\) in \(1\ldots N_{\text{\tiny{eda}}}\)do \(\mathcal{PS}_{\text{\tiny{ends}}}\leftarrow\emptyset\)// the set of (new) Pareto set candidates \(p_{g}\gets 0\) while\(|\mathcal{PS}_{\text{\tiny{small}}}|<N_{p}\) and \(p_{g}<P_{G_{\text{\tiny{max}}}}\)do /* obtain/generate a new path and add it to \(\mathcal{S}_{\text{\tiny{ocp}}}\) */ \(p\leftarrow\text{pgmc.newPath}(G_{3}^{\text{\tiny{(AB)}}},\mathcal{S}_{\text{ \tiny{ocp}}})\) \(\mathcal{S}_{\text{\tiny{ocp}}}\leftarrow\mathcal{S}_{\text{\tiny{ocp}}}\cup\{p\}\) /* perform dp-based pruned local search ('around' \(p\)) */ \(\mathcal{PS}_{\text{\tiny{ends}}}\leftarrow\mathcal{PS}_{\text{\tiny{ends}}} \cup\text{beamBestPathsFor}(p,G_{3}^{\text{\tiny{(AB)}}},\text{SIM},\mathbf{v}_ {t},\widetilde{\mathcal{PS}})\) \(p_{g}\gets p_{g}+1\) /* update the approx. of Pareto set; \(\mathcal{PS}_{\text{\tiny{max}}}\) - its new elems */ \((\widetilde{\mathcal{PS}},\,\mathcal{PS}_{\text{\tiny{max}}})\leftarrow\text{ paretoSet}(\widetilde{\mathcal{PS}}\cup\mathcal{PS}_{\text{\tiny{ends}}})\) /* update the distributions of pgmc (see Equation (6)) either for... */ ifrandUnif(0,1) > \(T_{d}\)(\(S\), \(N_{\text{\tiny{eda}}}\)) then  updatePGMc(\(\widetilde{\mathcal{PS}}\))//...all elems in the Pareto set or... else  updatePGMc(\(\mathcal{PS}_{\text{\tiny{max}}}\))//...only its new elems return \(\widetilde{\mathcal{PS}}\)
```  
**Algorithm 1**Multi-objective ship route optimisation using estimation of distribution algorithm (EDA) with dp-based pruned local search. **Remark 6**. : _Algorithm 1 (average-case) time complexity is determined by the number of \(EDA\) steps (\(N_{\text{eda}}\)), the maximum number of path generations at each step (\(P_{G_{max}}\)), and the average duration of single ab-path evaluation (\(t_{sim}\)), i.e.,_  
\[T=\Theta(N_{\text{eda}}\ P_{G_{max}}\ \mathbb{r}_{sim}). \tag{7}\]  
_The space complexity formula, \(\Theta\big{(}n_{r}\ n_{c}^{2}\ n_{v}^{2}\big{)}\), arises from the solution space representation._
# A Review of Irrigation Information Retrievals from Space and Their Utility for Users
## 4 Irrigation Modeling and Data Assimilation
In a successive study, [PERSON] et al. [119] assimilated GRACE TWS into the Noah-MP LSM with and without an irrigation scheme activated over the HPA, and found that the best overall performance was, over most of the study region, obtained when the data assimilation system was indeed coupled with the irrigation scheme. The inclusion of irrigation in land surface modeling, either by direct irrigation modeling alone or facilitated by data assimilation, is not only important to obtain consistent and accurate land surface estimates, but also to improve atmospheric and climate simulations. A wide range of studies assessing the irrigation effects on climate have focused on daily/annual irrigation amounts (e.g., [120; 121; 122]) or on evapotranspiration fluxes due to irrigation (e.g., [123]) as climate model input. [PERSON] et al. [114] used the Land Information System (LIS) together with the NASA Unified Weather Research and Forecasting Model (NU-WRF) framework to investigate the effects of drip, flood, and sprinkler irrigation methods on land-atmosphere interactions, including land-planet boundary layer coupling and feedbacks at the local scale. Overall, outcomes from LSM studies have shown that irrigation increases SM, leading to greater evapotranspiration with increases in latent heat flux and decreases in both sensible heat flux and coupling between SM and latent heat flux in water-limited environments (e.g., [111; 124; 125; 126]). This repartitioning of the surface energy and water balance causes lower surface air temperature and elevated atmospheric water vapor that contributes to the greenhouse effect [9; 111; 114; 125]. However, since the primary purpose of these coupled models is to study land-atmosphere interactions, LSM irrigation schemes generally ignore the source of water that is applied as irrigation and do not account for the impact that withdrawals have on groundwater or surface water processes. This may suffice when estimating on-field consumptive water use [111; 127; 128] or studying land-atmosphere interactions [113; 114; 129], but it prevents the application of these models to integrated water resource analysis or to evaluate trends in water storage [130]. In contrast, hydrological models have been developed in response to global water scarcity concerns, thus they tend to better represent human-driven hydrological processes such as irrigation [131]. Examples of such regional and global models include the WaterGAP model [132], or the WBMplus model [133]. While these models too may benefit from (irrigation) data assimilation, such studies are still pending.
## 2 Materials and Methods
### Breathing Rate Estimation  
We proposed an algorithm for estimating respiratory rate from the analysis of PML signals in the frequency domain. The underlying hypothesis is that breathing-related chest movements induce small periodic changes in signals associated with specific detection areas in relation to the subject's position on the bed.  
The PML signals were linear detrended and averaged to obtain a discrete time mean signal \(X(t)\). The mean signal \(X(t)\) was splitted in \(n\) epochs (\(x_{i}(t)\)) of 10 s time duration, and the epochs were overlapped of 50%. The first and last epochs (\(x_{1}(t)\) and \(x_{n}(t)\)) were zero-padded to obtain the same length as that of the other epochs. We estimated the power spectral density (PSD) of each linear detrended \(i\) epoch multiplied by a Hamming window by means of a Welch's estimator with a length of 400 time points (the length of each epoch multiplied for 10). The obtained PSD (\(s_{x_{i}}(f)\)) had a frequency resolution of 0.01 Hz. Then, the local maximum (\(m_{i}\)) of each \(s_{x_{i}}(f)\) was detected in the frequency range between 0.1 Hz to 1 Hz, as it corresponds to the frequency interval of breathing rate, which can be estimated (i.e., 6-60 bpm). Figure 6 shows an example of a PSD estimated from an \(i\) epoch and the associated local maximum in the frequency range 0.1-1 Hz.  
Finally, the frequency \(f_{i}\) of local maximum \(m_{i}\) was estimated, and the breathing rate (\(BR_{i}\)) associated with \(i\) epoch was evaluated as follows:  
\[BR_{i}=60\times f_{i} \tag{1}\]  
Finally, the estimated breathing rate sequences were filtered with a five-order one-dimensional median filter to remove possible outliers.
# Implementation of a Cryogenic Facility for Space Debris Analysis
###### Abstract  
This paper has resulted from a continued study of spacecraft material degradation and space debris formation. The design and implementation of a thermal vacuum cycling cryogenic facility for the evaluation of space debris generation at a low Earth orbit (LEO) is presented. The facility used for spacecraft external material evaluation is described, and some of the obtained results are presented. The infrastructure was developed in the framework of a study for the European Space Agency (ESA). The main purpose of the cryogenic facility is to simulate the LEO spacecraft environment, namely thermal cycling and vacuum ultraviolet (VUV) irradiation to simulate the spacecraft material degradation and the generation of space debris. In a previous work, some results under LEO test conditions showed the effectiveness of the cryogenic facility for material evaluation, namely: the degradation of satellite paints with a change in their thermo-optical properties, leading to the emission of cover flakes; the degradation of the pressure-sensitive adhesive (PSA) used to glue Velcro's to the spacecraft, and to glue multilayer insulation (MLI) to the spacecraft's. The paint flakes generated are space debris. Hence, in a scenario of space missions where a spacecraft has lost the thermal shielding capability, the failure of PSA tape and the loss of Velcro properties may contribute to the release of the full MLI blanket, contributing to the generation of space debris that presents a growing threat to space missions in the main Earth orbits.  
space debris; cryogenic facility; space material evaluation; thermal vacuum cycle; aerospace 2021  
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## 4 Platform Development of Key Technologies  
### Optimization Technology for the Resource Allocation of O&M Services  
As shown in Figure 5, in view of the diversified service demands of combine harvesters under different operation and maintenance modalities, the density of agricultural machinery in regional operations was taken as the main basis in the current study. Considering factors such as production seasonality, workload, regional environment, operating conditions, and agricultural machinery status, operation and maintenance forecast information was adopted on the basis of historical information and big data analysis. Comprehensive resource information analysis and mining of available technology, such as with respect to cluster operation service requirements, multi-level service network distribution, spare parts reserves, and service vehicles and personnel, were studied, and the problem of the extensive allocation of service resources was solved, thereby improving the effectiveness of resource allocation.
# LTDA-MAC v2.0: Topology-Aware Unsynchronized Scheduling in Linear Multi-Hop UWA Networks +
## 2 Linear TDA-MAC  
The TDA-MAC protocol [21] was originally designed to facilitate centralized packet scheduling in single-hop UASNs, i.e., where multiple sensor nodes are connected to a single master node. It was then extended to support dual-hop topologies in [22] and line network topologies in [8]. Its key differentiating feature compared with other schedule-based MAC protocols is that it does not require clock synchronization at the sensor nodes. Instead, the times of transmissions are determined locally at the nodes, based on the node-specific delays between receiving a request packet and transmitting their data packets.  
In this paper we focus on unsynchronized scheduling in LUASNs using the LTDA-MAC protocol [8]--a protocol designed specifically for networks with line topologies. Figure 1 depicts an example of a LUASN. Every sensor node only uses two connections--a  
Figure 1: Example of a linear UASN deployment in a subsea asset monitoring scenario (Reprinted with permission from ref. [8]. Copyright 2019 IEEE Networking Letters.).  
node one hop closer to the sink node (_up the chain_) and a node one hop further _down the chain_. The job of a sensor node is to transmit its own packets up the chain and forward data packets from sensor nodes down the chain.  
Figure 2 depicts an LTDA-MAC schedule, in this particular example based on one-hop interference range among the sensor nodes. In addition to scheduling their own data transmissions, Nodes 1 and 2 are responsible for forwarding the packets between the sink node and the other nodes down the chain. The LTDA-MAC schedule is defined by the delays between sensor nodes receiving a request (REQ) packet and transmitting a data packet. For a network comprising \(N_{\text{sn}}\) sensor nodes, the transmit delays that define an LTDA-MAC schedule can be expressed by a triangular matrix:  
\[\mathbf{T_{\text{tx}}}=\left[\begin{array}{cccc}T_{\text{tx}}[1,1]&T_{\text{tx }}[1,2]&\cdots&T_{\text{tx}}[1,N_{\text{sn}}]\\ \varnothing&T_{\text{tx}}[2,2]&\cdots&T_{\text{tx}}[2,N_{\text{sn}}]\\ \vdots&\vdots&\ddots&\vdots\\ \varnothing&\varnothing&\cdots&T_{\text{tx}}[N_{\text{sn}},N_{\text{sn}}]\\ \end{array}\right], \tag{1}\]  
where \(T_{\text{tx}}[i,i]\) is the transmit delay assigned to node \(i\) for sending its own data packets, \(T_{\text{tx}}[i,j]\) (\(i<j\)) is the transmit delay assigned to node \(i\) for forwarding data packets originating at node \(j\).
# Optimal Scheduling of Hydro-PV-Wind Hybrid System Considering CHP and BESS Coordination
## 6 Conclusions  
This paper proposed a concept of a renewable-based hybrid energy system which can effectively restrain the fluctuations in wind and photovoltaic generation to improve their stabilities. Taking into account the cost of operation and risk, an optimal scheduling model of this system was put forward. An optimization method was proposed based on Latin hypercube sampling, scene reduction, and piecewise linearization. The main achievements and conclusions are listed below:  
1. A concept of a renewable-based hybrid energy system including PV, WT, BESS, EV, CHP, and hydroelectric power was proposed to solve the reliable and economically justifiable integration of RES into the power system.
2. An optimal scheduling model of this system was put forward considering the cost of operation and risk.
3. An optimization method was proposed based on Latin hypercube sampling, scene reduction, and piecewise linearization to deal with multiple uncertainties, including renewable resource volatility, the load demand, and different energy service providers' coefficient of risk aversion.
4. Based on the real data obtained in China, the performance of the proposed model and method was evaluated. Results showed that the renewable-based hybrid system can not only reduce the intermittent and volatility of renewable resources but also ensure the smoothness of the tie-line power as much as possible. The effectiveness and the economy improvement of the proposed model and method were verified.
5. In future studies, the environmental factors of the hybrid energy system and how to deal with uncertainty efficiently in a power system can be studied. Hence, how to improve the reliable and economically justifiable integration of RES into the power system is worth further research.  
Investigation, methodology, and writing--original draft, S.T.; project administration, C.J. and X.W.; Data curation, X.W.; writing--review and editing, C.J.  
This research was jointly supported by the National Key R&D Program of China (grant No. 2018 YFB0905200).  
The authors declare no conflict of interest.
# Numerical Study of Concrete: A Mesoscopic Scale Simulation Methodology
###### Abstract  
This study aims to understand and simulate the mechanical properties of concrete, focusing specifically on the mesoscopic scale and its relation to the macro scale. Investigating concrete at this level involves examining its composition as a heterogeneous amalgamation of mortar, aggregates, and the Interfacial Transition Zone (ITZ). Numerical models, utilizing the finite element method (FEM), are employed to thoroughly examine the structural behavior of concrete. The study uses MATLAB (2023a) programming to develop three-dimensional models, which are then subjected to FEM analysis. Various mesoscopic Representative Volume Elements (RVEs) are formulated, considering spherical aggregates with different locations and dimensions to capture the complex nature of concrete. MATLAB is used to generate files containing comprehensive information about the RVEs, which are then processed with FEM to simulate compression strength tests. As the complexity increases with the inclusion of the ITZ, prismatic RVEs are developed to better represent real-world conditions. The proposed mesoscopic model establishes a foundational framework for a numerical simulation methodology tailored to laboratory compression tests, bridging the gap between mesoscopic and macroscopic scales. This approach provides detailed insights into concrete behavior, elucidating deformation and fracture mechanisms. Although not a complete substitute for experimental methods, these models offer a cost-effective and efficient alternative, identifying vulnerable areas and exploring the effects of additional materials on concrete behavior. The progressive replacement of laboratory tests with numerical simulations using RVEs of specific compositions will make the study of concrete behavior at the mesoscopic scale increasingly sustainable, paving the way for more efficient and environmentally friendly research practices in the field.  
mesoscopic scale; numerical model; concrete behavior Article