esa-sceva/satcom-chunk-collection huggingface dataset:
# Dynamic Preventive Maintenance Optimization of Subway Vehicle Traction System Considering Stages
## 3 Single-Component Maintenance Model  
### Repaired \"Non-New and Non-Old\" Model  
In the traditional research on maintenance theory, people usually assume that there are two maintenance results: \"repaired as new\" or \"repaired not new\". The \"repaired as new\" assumption assumes that after preventive maintenance, the performance of a component can be restored to its original new condition. In traditional preventive maintenance, the maintenance interval of a component is fixed. It is assumed that the component will be \"repaired as new\" after each preventive maintenance. The \"repaired not new\" assumption assumes that the performance of a component is restored after preventive maintenance, but the failure rate remains the same. It returns to the state as bad as the moment before the maintenance. Both limit cases are not in line with the practical engineering application. With the degradation of component performance, the repaired \"non-new and non-old\" component after each maintenance is more realistic. It is restored to neither the initial new state nor the poor state immediately before the maintenance, but a state in between. In order to describe these two cases, the service age decreasing factor and the failure rate increasing factor are introduced [38; 39].  
Figure 3: Schematic diagram of group preventive maintenance strategy.  
From the service age decreasing factor and the failure rate increasing factor, a case that is more in line with practical engineering application can be obtained. It is not only that the service age of the components decreases, but the rate of change in the failure rate increases after each preventive maintenance. Therefore, the repaired \"non-new and non-old\" model is to combine the effects of the service age decreasing factor and the failure rate increasing factor. A more realistic failure rate function is established. The evolution law of failure rate is shown in Figure 4. The failure rate function is:  
\[\begin{split}\lambda_{i+1}(t)&=\beta_{i}\lambda_{ i}(t)(t+\alpha_{i}T_{i})=\left(\prod\limits_{j=1}^{i}\beta_{j}\right)\lambda(t+ \sum\limits_{j=1}^{i}\alpha_{j}T_{j}),\\ & 0<\alpha_{i}\langle 1,\beta_{i}\rangle 1,t\in(0,T_{i}),i=1,2, \cdots,N\end{split} \tag{3}\]  
where \(\alpha_{i}\) is service age decreasing factor and \(\beta_{i}\) is failure rate increasing factor.  
The service age decreasing factor and the failure rate increasing factor can be variables or constants. The correctness of their values determines whether the model is effective and feasible. According to the historical failure conditions of the components, the values can be obtained by empirical value method, failure rate fitting method or maintenance cycle fitting method [40].
## 3 Case Studies
### Fire Safety Verification Methods--Applicable Design Scenarios
#### 3.7.2 Concealed Space  
In this design scenario, the fire starts in a concealed space between two rooms. This fire can be electrical in origin and develop behind a curtain or within a wall with a slow-growth fire (\(\alpha\) = 0.0117 kW/s\({}^{2}\)). It is assumed that the initial fire is in the bedroom and the fire develops to engulf the mattresses (data from fire test from mattresses re-reported in SFPE Handbook [8] to be around 2 MW).
## 2 Materials and Methods  
### Study Areas  
We chose the Beijing-Tianjin-Hebei urban agglomeration (BTH) and the National Capital Region of Japan (NCRJ) as research areas in this study (Figure 1). The BTH urban agglomeration is a major urban agglomeration in China, located in Eastern China, which includes the Beijing and Tianjin Municipalities and 11 prefecture-level cities in Hebei Province. The BTH urban agglomeration covers an area of about 218,000 square kilometers. In 2021, the total population of the BTH was about 110 million, accounting for 7.8% of China's total population; the GDP reached CNY 9635.59 billion, accounting for about 8.4% of China's total GDP. The NCRJ is located in the Kanto region of Japan, covering eight prefectures, including Tokyo, Kanagawa, Chiba, Saitama, Ibaraki, Tochigi, Gunma, and Yamanashi. The NCRJ covers an area of about 37,000 square kilometers, with a population of about 44 million in 2021, accounting for about 35% of Japan's total population. The region's GDP was about JPY 231,702.9 billion, accounting for about 40% of Japan's total GDP. There are similarities between the BTH and NCRJ from the natural conditions. BTH is located at between 36 and 42 degrees north latitude with a high elevation of over 1000 m in the northwest and low elevation of below 15 m in the southeast. The NCRJ is located at between 35 and 37 degrees north latitude with a high elevation of over 800 m in the northwest and low elevation of below 30 m around Tokyo Bay. Both the BTH and NCRJ are in mid-latitude regions and have a similar topography. Although the BTH urban agglomeration and NCRJ are different in terms of their population and scale, they are both important economic, cultural, and political centers with intensive economic activities. The population density and economic development of the NCRJ are higher than the BTH. However, Japan's carbon emissions have declined since 2013, according to data released by the National Institute for Environmental Studies [63]. On the one hand, comparing regions of different countries at different stages of development highlights the diversity and regional characteristics of the results. On the other hand, the results can also provide references for developing countries' emission management and development planning to a certain extent.
# A Game-Theoretic Rent-Seeking Framework for Improving Multipath TCP Performance +
## 5 Evaluation
### Additional Experiments
#### 5.5.3 Observation 9  
Scenario 9 investigated fairness between TCP and MPTCP. Specifically, we considered a scenario of five MPTCP connections when one of the paths was shared with five regular (single-path) TCP connections.  
The results obtained by using Scenario 9 are shown in Figure 10. Figure 10 illustrates the throughput perceived by both TCP and MPTCP connections, which demonstrated the following: RSF MPTCP was quite friendly towards TCP while providing better throughput than the other MPTCP algorithms.  
Figure 10 shows that when RSF-DB MPTCP was used, the throughput achieved by regular TCP flows was comparable to that obtained while competing with the other MPTCP algorithms. However, the corresponding MPTCP connection had much higher throughput. More specifically, when compared to the other MPTCP algorithms, the performance of TCP  
Figure 10: Throughput results for Scenario 9: competing TCP flows. Both paths had 20 Mbps bandwidth, 150 ms delay, and 2% packet loss probability. One path had five additional regular TCP flows, as well.  
Figure 9: Throughput results for Scenario 8: path failure. Both paths had 20 Mbps bandwidth, 150 ms delay, and 2% packet loss probability. One path (WiFi) became unavailable at 50 s.  
when competing with cooperative MPTCP flows was slightly lower, but the throughput gain for MPTCP was very high. The throughput gain rose because of RSF MPTCP's ability to exploit the capacity of both available paths. The reason for the slightly reduced TCP throughput needs further investigation, and this remains for future work. The observation with RSF-LB was also similar.
## 3 Results and Discussions
### Pore Structures  
#### 3.2.1 MIP Test Results  
The TPV and SSA obtained from the MIP test varied in the ranges 0.0275-0.0338 cm\({}^{3}\)/g and 7.5-12.67 m\({}^{2}\)/g, with mean values of 0.03 cm\({}^{3}\)/g and 10.9 m\({}^{2}\)/g, respectively.  
As shown in Figure 3A, the shapes of the mercury intrusion-extrusion curves were similar and could be divided into two distinct parts. When the pressure was small (corresponding to pore diameters in the range 50-10,000 nm), the mercury volume gradually increased; however, when the pressure was high (pore diameter of 6-50 nm), the volume increased rapidly. This indicates that the samples developed considerable micro-transitional pores. The mercury intrusion-extrusion curves were extremely narrow and practically parallel, indicating that the samples primarily developed semi-closed pores. These pores may remarkably affect pore connectivity, and thereafter prevent CBM output [44].
# Quantitative Characterization of Micro-Scale Pore-Throat Heterogeneity in Tight Sandstone Reservoir
## 4 Conclusions  
(1) Through casting thin section analysis of the Chang6\({}_{3}\) reservoir samples in the research area, it is concluded that the main reservoir spaces are intergranular pores, feldspar dissolution pores, cuttings dissolution pores, intercrystalline pores and micro-fractures, etc. The shape of the orifice throat is mainly a sieve tube shape, strip shape and ball shape, and its quality is successively worse.  
(2) Based on the constant velocity mercury-injection technique, the pore and throat radius distribution characteristics of the Chang 6\({}_{3}\) reservoir in the Huaqing area are studied, and it is considered that the pore and throat combination types of the Chang 6\({}_{3}\) reservoir in the study area mainly include macro pore-thin throat, macro pore-fine throat and macro pore-micro throat.  
(3) Under the guidance of information entropy theory, the quantitative characterization model of pore-throat microscale heterogeneity in a tight oil reservoir is established. The pore-throat heterogeneity of different reservoirs is obviously different. Moreover, the distribution uniformity of throat in macro pore-thin throat, macro pore-fine-throat and macro pore-micro throat reservoirs becomes worse successively.  
(4) The heterogeneity of pore and throat is the key factor to determine the physical property, seepage mechanism and oil recovery of a tight sandstone reservoir. The pore uniformity is negatively correlated with porosity, permeability and movable fluid saturation. However, throat uniformity and combined pore-throat uniformity are positively correlated with porosity, permeability and movable fluid saturation. Therefore, the uniformity of throat development controls the reservoir and seepage capacity of the Chang 6\({}_{3}\) tight sandstone reservoir in the study area and restricts the oil recovery factor.  
Conceptualization, F.D.; Formal analysis, Z.G. and X.L.; Investigation, Y.C., H.H. and D.R.; Writing--original draft, F.D. and Z.S. All authors have read and agreed to the published version of the manuscript.  
This work was financially supported by the National Natural Science Foundation of China (41802166 and 51874240), Shaanxi Province Natural Science Basic Research Program (2022 JM-166, 2022 JC-37 and 2017 JQ4005), Shaanxi Province Key Research and Development Program (2021 GY-140), and the Graduate Student Innovation and Practice Ability Training Program of Xi'an Shiyou University (YCS21113101). We are grateful for the support of these projects.  
Not applicable.  
The authors declare no conflict of interest.
## 3 Proposed Electronically Tunable Mixed-Mode Universal Filter
### Operation in VM and TAM  
In this mode of operation, all input currents (\(I_{1}\)-\(I_{3}\)) are set to zero. The input voltages (\(V_{1}\)-\(V_{3}\)) are applied as per the sequence given in Table 3. The filter transfer functions and expression for pole frequency and quality factor are given in Equations (15)-(18):  
\[V_{out}=\frac{V_{1}g_{m1}R_{2}-g_{m1}R_{2}R_{1}sC_{1}V_{3}+s^{2}C_{1}C_{2}R_{1 }R_{2}V_{2}}{s^{2}C_{1}C_{2}R_{1}R_{2}+sC_{1}R_{1}+g_{m1}R_{2}} \tag{15}\]  
\[I_{out(TAM)}=\frac{1}{R_{2}}\frac{V_{1}g_{m1}R_{2}-g_{m1}R_{2}R_{1}sC_{1}V_{3}+ s^{2}C_{1}C_{2}R_{1}R_{2}V_{2}}{s^{2}C_{1}C_{2}R_{1}R_{2}+sC_{1}R_{1}+g_{m1}R_{2}} \tag{16}\]  
\[\omega_{0}=\sqrt{\frac{g_{m1}}{C_{1}C_{2}R_{1}}} \tag{17}\]  
\[Q=R_{2}\sqrt{\frac{C_{2}g_{m1}}{C_{1}R_{1}}} \tag{18}\]  
The Equations (17) and (18) imply that when the frequency is varied, the quality factor of the filter will be slightly affected. The frequency can be tuned without affecting the quality factor if \(g_{m1}\) and \(R_{1}\) are varied simultaneously such that the product (\(R_{1}\)-\(g_{m1}\)) remains constant. The resistor can be realized using a MOS [44] transistor, making it easily tunable.  
Figure 3: Proposed mixed mode universal filter employing VD-EXCCII.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Response**} & \multicolumn{3}{c}{**Inputs**} & \multicolumn{2}{c}{**Passive Matching**} \\ \cline{2-5}  & \(\mathbf{V_{1}}\) & \(\mathbf{V_{2}}\) & \(\mathbf{V_{3}}\) & **Condition** \\ \hline LP & 1 & 0 & 0 & No \\ HP & 0 & 1 & 0 & No \\ BP & 0 & 0 & 1 & No \\ BR & 1 & 1 & 0 & No \\ AP & 1 & 1 & 1 & 1 = \(g_{m1}R_{2}\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Input excitation sequence of operation in VM and TAM.
## 3 Environmental Applications of Organoclays
### Soil Pollution  
A variety of organic and inorganic pollutants can enter the soil and water environment. In this part, we focus on toxic substances, such as heavy metals, and some solid-phase organic pollutants, such as anthracene, which badly affect drinking water and plants. In most cases, heavy metals can accumulate in the plants and affect the ecosystem. Table 2 focuses on the applicability of clay and organoclay for removing solid contaminants. It can be seen from the table that limited clay was used to remove this type of contaminant, which is due to the weak bond strength between the contaminants and the clay. For the removal of heavy metal waste by clay and modified clay, [PERSON] and [PERSON] [28] studied the phenomenon, where they found that montmorillonite clay and kaolinite clay are enriched with many polyoxyations, such as Zn\({}^{2+}\), Si\({}^{4+}\), Ti\({}^{4+}\), Al\({}^{3+}\), Fe\({}^{3+}\), Cr\({}^{3+}\), Ga\({}^{3+}\), etc. A similar trend of works over the past 10 years has also been observed when montmorillonite clayis enriched with Mg, Fe\({}_{2}\)O\({}_{3}\) nanoparticles, Fe\({}^{3+}\), Iron, Ferrihydrite, Goethite, etc., that are used to remove phenol, Hg\({}^{2+}\), Cr\({}^{3+}\), Pb\({}^{2+}\), Zn\({}^{2+}\), As\({}^{5+}\), Cd\({}^{2+}\), Cr\({}^{6+}\), Co\({}^{2+}\), Cu\({}^{2+}\), Ni\({}^{2+}\), etc. [PERSON] et al. [29] synthesized a Fe\({}_{3}\)O\({}_{4}\)-CuO-modified montmorillonite clay catalyst for the degradation of anthracene-contaminated soil. The task of the montmorillonite clay was to prevent the agglomeration and crystallization of Fe\({}_{3}\)O\({}_{4}\)-CuO. Using a clay catalyst (1 g/kg) with ClO\({}_{2}\) as the oxidative degradation material (1 mol/kg), a 96.2% degradation
# Safety Analysis and Condition Assessment of Corroded Energy Pipelines under Landslide Disasters
## 1 Introduction
Numerous studies have been conducted regarding the mechanical behavior of corroded pipelines. These primarily focus on the mechanism of corrosion [28; 29; 30], the impact of corrosion dimensions on pipelines [31; 32; 33], and the interference effects under multiple corrosion factors [34; 35] based on studies of intact pipelines. However, there is limited research addressing the safety of energy pipelines considering the synergistic effect of corrosion and landslides. To fill the gaps identified, this study develops a rigorous FE model of corroded pipelines under landslides to analyze the circumferential stress, axial stress, and the location of maximum von Mises stress considering various dimensions and positions of corrosion defects. Parameter effects, including the corrosion size, origin location, and landslide displacement are analyzed to ascertain the mechanical response patterns of the pipeline under landslides. This work helps to assess the condition of long-distance energy pipelines under landslides and make wise risk management decisions. The remainder of this paper is outlined as follows: Section 2 presents the theoretical foundations of the pipeline across landslides; Section 3 details the implementation of the FE modeling; Section 4 analyzes the influencing factors and the detailed patterns between corrosion and stress; a prediction equation is proposed in Section 5 to determine the maximum stress and the most disadvantageous position of corroded pipelines; and finally, this work concludes in Section 6.
## 4 Method Validation
### Experiment and Results
#### 4.1.3 Results of Meter Reading  
All 500 images in the pointer and digital meter test set are randomly divided into sub-test sets containing 500, 300, 100, and 50 images, and the readings are recognized using the method proposed in this paper with the accuracy rates in Tables 6 and 7. Numbers with an error of less than 0.5 are considered correct values.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample Statistics** & **Correct (Errors \textless{} 0.5)** & **Accuracy** \\ \hline
500 & 412 & 82.40\% \\
300 & 249 & 83.00\% \\
100 & 86 & 86.00\% \\
50 & 45 & 90.00\% \\  & Average accuracy & 85.35\% \\ \hline \hline \end{tabular}
\end{table}
Table 6: Test results of pointer meter reading.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample Statistics** & **Correct** & **Accuracy** \\ \hline
1500 & 1372 & 91.40\% \\
1000 & 921 & 92.10\% \\
500 & 469 & 93.60\% \\
100 & 96 & 96.00\% \\  & Average accuracy & 93.28\% \\ \hline \hline \end{tabular}
\end{table}
Table 5: Test results of meter classification.  
In conclusion, the proposed pointer meter reading algorithm in this paper has a combined accuracy of 85.35% and the digital meter reading algorithm has a combined accuracy of 90.73%.
## 3 Results and Discussion
### Cell Line Measurements
#### 3.1.3 Barrier Integrity Measurements After Permeability Experiments  
The barrier integrity of the respiratory epithelial models after permeability assays was assessed using transepithelial electrical resistance (TEER) measurements and permeability assays with two marker molecules: sodium fluorescein and Evans Blue-labeled albumin (Figure 3). No changes in barrier integrity were observed for either the tested active agent or the DPI formulations in the culture models, as reflected by the unaltered TEER values of the cell layers and permeability values for two marker molecules compared to the control group (Figure 3A-D). These results indicate that neither raw KTP nor the developed DPI formulations exerted harmful effects on the barrier, suggesting their potential for safe application. Our findings are in line with previously published results on nasal epithelial cells [22], where TEER values remained at the level of the control group after 1-h treatment with meloxicam nanonformulation indicating that it does not damage the barrier function. This further supports the safety of our DPI formulations.  
Figure 2: Permeability of KTP raw, F0, and F1 DPIs (50 \(\upmu\)g/mL KTP concentration in the donor compartment) across the co-culture model of (**A**) alveolar epithelial cells and (**B**) bronchial epithelial cells after 30- and 60-min assay time. Values are presented as means \(\pm\) SD, \(n=4\). Statistical analysis: ANOVA followed by Dunett’s test. **\(p<0.01\), ***\(p<0.001\).
# The Online Reservation Problem
## 3 Algorithms
### Greedy Algorithms  
A greedy algorithm is one that assigns a job to a server with no conflicts, whenever at least one such server exists. Otherwise, it declines the job.  
**Theorem 3**: _The following statements regarding the CR of an arbitrary greedy algorithm \(A\) are true._  
1. \(r_{A}(1,\Delta)=2\) _if_ \(\Delta=1\)_._
2. \(r_{A}(1,\Delta)=2\Delta+1\) _if_ \(\Delta>1\)_._
3. \(r_{A}(n,\Delta)\leq 3\) _if_ \(\Delta=1\) _and_ \(n\in\mathbb{N}\)_._
4. \(2\Delta+1\leq r_{A}(n,\Delta)\leq 2\Delta+2\) _if_ \(\Delta>1\) _and_ \(n\in\mathbb{N}\)_._  
**Sketch of the Proof.** The key challenge in establishing an upper bound \(r_{A}\) is to come up with allocation schemes from the sets of jobs tha are accepted by Algorithm \(A\) to offline optimal sets such that Lemma 1 can be applied. The detailed proof along with the allocation schemes is given in Appendix C.  
The upper bound in the first statement is tight because of a matching lower bound from Theorem 2. The lower bounds in the second and fourth statements are proved by identifying specific instances and calculating the ratio \(OPT(L)/v_{A}(L)\) for them. The lower bound so proved is tight for the second statement.  
The statements in theorem above provide results for cases that are based on:  
* whether \(n=1\) or \(n>1\), and
* whether \(\Delta=1\) or \(\Delta>1\).  
By separately considering the four cases, we are able to derive more accurate bounds. Note that, for any given \(\Delta\), upper bounds are smaller for \(n=1\) when compared to those for \(n>1\). Intuitively, this happens because, when \(n>1\), the owner must not only decide whether to accept or decline a job, but he/she must also assign the accepted jobs to one of the multiple servers. This additional level of decision-making causes the CR to deteriorate. Additionally, note that, for any given \(n\), the CR is increasing in \(\Delta\). This directly follows from the definition of CR. All of the phenomena discussed in this paragraph also hold true for Theorems 4 and 5 that are presented in the subsequent sections and that contain bounds on CRs of Algorithms \(D\) and \(R\), respectively.  
It follows from Theorems 2 and 3 that the CR of any greedy algorithm is optimal when \(n=\Delta=1\). Additionally, just like the lower bound on CR of any online algorithm (Theorem 2), the CR is increasing in \(\Delta\). However, the rate of increase is linear instead of logarithmic. This gap motivates the needfor algorithms with better CRs. Intuitively, the rate of increase is linear because, in some instances, a greedy algorithm only accepts jobs with duration close to \(D_{min}\). These decisions prevent it from accepting overlapping jobs with duration \(D_{max}\) that arrive in the future and that would have been accepted instead if we knew the entire instance upfront.
# Fire Performance of Self-Tapping Screws in Tall Mass-Timber Buildings
## 2 Materials and Methods  
Most of the research focussed on the fire performance of connections has investigated connections made with bolts and dowels. Theses fasteners require the pre-drilling of holes on the structural elements, and an initial gap created between the hole and the timber affecting the moment resistance of the connection [25]. Instead, STS, developed to reduce the time of installation, have the advantages of preventing wood splitting and eliminating the need for pre-drilling [17]. With their excellent withdrawal resistance, STS are made with high-strength steel and are mostly used to connect mass timber panels, for gulam header-to-beam connections, and for the local reinforcement of timber elements [17]. In buildings requiring some level of fire-resistance, designing connections for fire conditions remains a challenge [12], where gulam members are used as part of the primary structural frame and required fire-resistance at connections. However, the connections between glued laminated timber members often include steel fasteners, where steel and timber behave differently, and their interaction makes the assembly difficult to evaluate [12].