esa-sceva/satcom-chunk-collection huggingface dataset:
# Trajectory Optimization with Dynamic Drivable Corridor-Based Collision Avoidance
###### Abstract  
Trajectory planning for autonomous vehicles is essential for ensuring driving safety, passenger comfort, and operational efficiency. Collision avoidance constraints introduce significant computational complexity due to their inherent non-convex and nonlinear characteristics. Previous research has proposed the drivable corridor (DC) method, which transforms complex collision avoidance constraints into linear inequalities by constructing time-varying rectangular corridors within the spatiotemporal domains, thereby enhancing optimization efficiency. However, the DC construction process involves repetitive collision detection, leading to an increased computational burden. To address this limitation, this study proposes a novel approach that integrates grid-based obstacle representation with dynamic grid merging to accelerate collision detection and dynamically constructs the DC by adaptively adjusting the expansion strategies according to available spatial dimensions. The feasibility and effectiveness of the proposed method are validated through simulation-based evaluations conducted over 100 representative scenarios characterized by diverse and unstructured environmental configurations. The simulation results indicate that, with appropriately selected grid resolutions, the proposed approach achieves up to a 60% reduction in trajectory planning time compared to conventional DC-based planners while maintaining robust performance in complex environments.  
trajectory planning; numerical OCP; collision avoidance; dynamic drivable corridor
# Reversible and Plausibly Deniable Covert Channels in One-Time Passwords Based on Hash Chains +
## 2 Fundamentals and Related Work
### Related Work  
Covert channels have been proposed for several domains. For instance, [PERSON] and [PERSON] surveyed out-of-band covert channels over physical media, such as light, sound and air [13] while other authors analyzed details of such channels, e.g., [PERSON] and [PERSON] [14], [PERSON] et al. [15] and [PERSON] et al. [16]. Network covert channel techniques have been summarized by [PERSON] et al. [17], [PERSON] et al. [9] and [PERSON] et al. [18]. Detailed studies of specific network covert channels and their countermeasures were performed by [PERSON] et al. [19], [PERSON] et al. [20], [PERSON] et al. [21], [PERSON] et al. [22] and [PERSON] et al. [23], just to mention a few. Further, several local covert channels have been studied, e.g., on smartphones by [PERSON] et al. [24] and [PERSON] et al. [25], in the architecture of processors by [PERSON] and [PERSON] [26], as well as in real-time schedulers by [PERSON] et al. [27]. Most recently, covert channels in the Internet of Things has gained increasing attention, cf. works by [PERSON] et al. [28], [PERSON] et al. [29] and [PERSON] et al. [30].  
[PERSON] et al. [31] described a covert channel in which OTPs are used as an element for generating random data for a covert channel that exploits rate switching in 802.11 b WiFi networks. In comparison, our approach allows an Internet-wide application that is not limited to wireless environments. Moreover, our approach represents an indirect covert channel based on hash chain exploitation. To the best of our knowledge, no other covert channel has been published that exploits cryptographic hash chains.  
Plausible deniability for steganography has been proposed by several authors, especially for filesystems (e.g., [32]). In the context of video streams, PRNG-output was utilized [33]. [PERSON] published a covert channel that embeds DES-encrypted data into third-party TCP initial sequence numbers (ISN) [34]. However, [PERSON] and [PERSON] have shown that the channel by [PERSON] is detectable, since the distribution of ISN values does not match the distribution of DES-encrypted covert data [35]. [PERSON] [36] presents a covert channel in the check sum of IP packets, which, however, does not use a cryptographic hash function.  
Several methods for reversibility analysis of network covert channels have been studied by [PERSON] et al. [11], while earlier works studied reversibility in digital media steganography, e.g., [PERSON] and [PERSON] in [10; 37].  
The remainder of this paper is structured as follows. Our two covert channels based on hash chains are introduced in Section 3. We discuss countermeasures for our covert channels in Section 4 and evaluate the performance and stealthiness characteristics of our channels in Section 5. Section 6 concludes and provides an outlook on future work.
## 3 Results and Discussion
### Performance Characterization of Dust Suppressant
#### 3.2.2 Test for Toxicity to Plant  
In order to accurately measure the toxicity of the dust suppressant to green plants, holly seedlings with the same or similar conditions were planted under the same light source, temperature, and humidity conditions. The experimental temperature was 24 \(\pm\) 2 \({}^{\circ}\)C and humidity was 40 \(\pm\) 5%; under these conditions, the growth status of plants was observed, and the results are shown in Figure 8a. Two weeks later, after the holly seedlings grew into stable conditions, equal amounts of dust suppressant solution and pure water were sprayed at the roots of two groups of plants, respectively. The testing solution was sprayed once at 10:00 a.m. each day for 7 days. The survival rate and the chlorophyll content of plants were determined (Figure 8b).  
Based on the macroscopic observation of the growth conditions of each group of holly plants, within a certain range, dust suppressant solutions in each concentration had no significant influence on the growth of holly plants, and there was no obvious toxic effect. According to the experimental data in Table 7, the growth rate of holly plants cultured with dust suppressant solution was not slower than holly plants cultured with pure water, and the inhibition percentage was smaller than 0; namely, the survival rate of  
Figure 8: (**a**) Plant culture; (**b**) chlorophyll extraction.  
holly cultured with dust suppressant solution was 100%, showing that the dust suppressor had no inhibition effect on the growth of holly; instead, it played a certain facilitating role.  
According to the data in Table 8, the dust suppressant solution can promote the photosynthesis of plants and thus increase their chlorophyll content. In summary, both macroscopic and microscopic studies have proven that the ecological dust suppressant developed herein has no toxic impact on green plants; instead, it can promote the photosynthesis and growth of plants to a certain extent.
## 4 Materials and Methods for Designing Tether-Deployed Constellations
### Orbit Design
#### 4.2.6 Neutral Release Orbit Optimization Independent of Arguments of Periapses  
If the optimization of distribution of either release orbits is not required, these orbits can be produced in a manner allowing the payload orbits to have varying arguments of periapses, potentially leading to either circular or flower orbit configurations with one or more release points along the deployer's orbit. The existence of gaps when optimizing the retrograde release orbit and overlaps when optimizing the prograde release orbit implies that there are one or more intermediary \"neutral\" options that lead to complete coverage of both release orbits, but expectedly in a slightly non-uniform distribution pattern. The benefit of not optimizing one release orbit over the other is this more equal distribution quality between both orbits, and potentially quicker dispersion times thanks to not needing to wait for specific orbit syncing between the deployer and either prograde or retrograde orbits. These configurations are shown in Figures 25 and 26.  
There are several different approaches by which this neutral optimization can be pursued, but they are dependent on mission-specific orbit parameters and would need to  
Figure 25: Prograde non-concentric elliptical release trajectories with 4 release points (retrograde orbits hidden).  
be determined on a case-by-case basis. Generally though, this can be done in a way that alternates priorities between prograde and retrograde releases to populate both release orbits. It is also likely advantageous to set the deployer orbit to be circular to allow for the most balanced distribution of minimum and maximum altitudes by each payload in their respective release orbits. A graphic depicting different regions for payload distribution with neutral optimization is given in Figure 27, and is primarily composed of geometries presented in their simplified forms in Figures 25 and 26.  
Figure 27: Basic payload orbit regions for neutral priority distribution optimization with 8 release points.  
Figure 26: Retrograde non-concentric elliptical release trajectories with 4 release points (prograde orbits hidden).
## 3 Results and Discussion  
### Biodegradability  
As presented in Figure 3, the biodegradation of the ramie fiber/starch nonwoven film started with a rapid degradation period of 4 days, in which time the diurnal degradation rate (4.08%/day on average) was very close to that of the cellulose (reference material) (4.73%/day on average). This was followed by a much slower, but roughly constant, (0.86%/day on average) degradation period, which continued until day 60 (at day 60 the degradation degree was 64.5%). In a slightly different way, the cellulose degraded at a roughly constant rate (3.29%/day on average) until day 20 (at day 20 the degradation degree was 65.9%). After that, the degradation degree tended to be constant. At the end of the determination period (day 72), the degradation degree of the cellulose reference and the film were 77.1% and 65.6%, respectively. Because the degradation degree of the film in the first  
Figure 2: Diagram of the experimental device (not yet covered by seedling soil).  
4-days (16.3%) was slightly greater than the mass ratio of corn starch in the film (14%), we inferred that the rapid degradation of the film during the first 4-days was mainly due to the degradation of the modified corn starch, as it degraded more easily than ramie fiber. In other words, when the film is embedded in the soil, the adhesive material will biodegrade rapidly, but the fiber skeleton will remain and work for a relatively longer time.
## 3 Results
### Silver Nanoparticles
By using the isolated extract, they showed a decrease in cell viability up to a concentration of 250 mg/mL without being able to reach the IC\({}_{50}\) value. Meanwhile, the binding of the extract to silver nanoparticles led to an increase in its cytotoxic effect, obtaining an IC\({}_{50}\) of 300 ug/mL. This improvement was due to the induction of apoptosis by this nanformulation through increased oxidative stress after the treatment of cells, as demonstrated by an overexpression of caspases 3 and 9 and an overexpression of the pro-apoptotic protein BAX. Additionally, these nanoparticles possessed anti-inflammatory effect through attenuation of nitric oxide and superoxide anion production in macrophages [33]. Lastly, regarding the study of silver NPs, [PERSON] et al. (2013) studied the possible cytotoxic effect with the use of methanol extract of _Vitex negundo_ leaves. In the CRC HCT-15 line, an IC\({}_{50}\) of 150 ug/mL was obtained for the extract alone, whereas when the extract was encapsulated in a silver nanoformulation, its value decreased to 20 ug/mL. In this case, extract encapsulation allowed a greater induction of cell apoptosis and genotoxicity, which was demonstrated through increased tails in a comet assay [34]. In contrast to the data obtained in the previously mentioned studies, in the assay performed by [PERSON] et al. (2017), the binding between NPs and the natural extract could not be demonstrated to be superior to the isolated extract. In both cases, the IC\({}_{50}\) obtained was similar, at around 0.625 ug/mL. But this study highlights the fact that several apoptosis pathways were activated, thereby elevating free radicals (ROS) and leading to cell death. These data reveal a basic benefit obtained from the use of _Balanties aegyptiaca_ extract, opening the possibility of greater antitumor activity in the case of finding a NP that reinforces its activity [35]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
###### Abstract  
Anti-islanding detection methods have been part of a secure operation for distributed energy resource inverters, avoiding the creation of non-intentional energization when the mains are lost. These detection mechanisms were conceived historically for current-controlled inverters. New control possibilities have broken ground, and current- or voltage-controlled inverters are a reality; however, special attention must be paid to detection strategies when applied to the latter ones. This paper addresses two topics: it exposes the lack of effectiveness of those detection algorithms based on the voltage/frequency displacement concept under voltage-controlled inverters and evaluates the applicability limits of the others based on the impedance measurement (IM). The IM is presented as a valid mechanism to achieve the islanding detection, but the exploration of its limits drives the concept of detection frequency bandwidth (DFBW), introduced in this paper. The DFBW is suggested as a practical approach to select the proper injection frequency to measure. Therefore, an improved strategy based on the IM and DFBW is proposed to allow achieving the detection towards (non-)resonant loads considering low computational burden. The results were experimentally validated in a 90-kVA four-wire voltage-controlled inverter, offering detection times of less than 100 ms in any case.  
Keywords:anti-islanding; voltage source converters; impedance measurement; microgrids +
Footnote †: journal: Applied Sciences
# Enhancement of High-Intensity Focused Ultrasound Heating by Short-Pulse Generated Cavitation
## 3 High-Speed Observation of Cavitation Bubbles Induced by Trigger HIFU Exposure
### Cavitation Generated in Multiple Focal Spots  
Methods of focal spot scanning have been investigated for highly efficient ultrasonic heating [67, 68, 69, 70, 71]. In the studies, the distribution of estimated temperature was used as a feedback information to obtain uniform thermal doses in the larger target regions than that by a conventional HIFU exposure. The larger coagulation region contributed to the efficient use of the ultrasonically generated heat through minimizing the surface-area-to-volume ratio. Similarly, as mentioned in the previous section, multi-trigger HIFU sequences for the lateral enlargement of the treated region have been investigated to effectively coagulate a target tissue [29, 32, 33, 34, 35].  
Figure 7 shows the high-speed images of bubble clouds generated by trigger pulses in six focal positions [34]. The target was a PAA gel including 15% BSA placed in a water tank. The images of  
Figure 6: High-speed pulse inversion (PI) images with two-plane wave transmissions of a PAA gel phantom containing a 0.5% graphite layer with a thickness of 0.75 mm [36]. **(a,b)** PI images before and 0.9 ms after the stop of the trigger pulse exposure, respectively; **(c–f)** difference PI images between before and 0.9 ms after the stop of the heating burst exposure with durations of 0, 1, 10, and 100 ms, respectively.  
bubbles were taken with the same camera and pulse laser in the experiment of the previous subsection though the optical magnification was smaller than that in the previous experiment. A HIFU transducer and driving system were also the same. The driving frequency was 1 MHz in this experiment. The temperature and dissolved oxygen in water were kept at 36 \({}^{\circ}\)C and 20%-30%, respectively. The applied trigger HIFU sequence was similar to that shown in Figure 1b. The differences were the acoustic powers, the interval time between the heating bursts focused at the adjacent focal positions, and the position of the focal plane of trigger pulses. The instantaneous total acoustic powers of the trigger pulses and heating bursts were 1900 and 65 W, respectively. The duration and interval time of the heating bursts were 25 and 2 us, respectively. The intentional focal plane shift of the trigger pulses was not applied in this case.  
Bubble clouds in the two focal positions are seen in the first picture of Figure 7 at 50 us when the second trigger pulse is exposed. At 650 us, almost the end of the first set of the trigger pulses, cavitation bubbles are observed in the expanded area corresponding to the six focal positions. After 10 s of HIFU exposure, bubble clouds were generated in the almost same position and region to that at the beginning of the HIFU exposure as shown in the first picture of Figure 7. Cavitation bubbles in a much larger region than that by a single spot focus method can be used to accelerate a HIFU treatment by the rapid spot scanning method.
# XGBoost-Based Detection of DDoS Attacks in Named Data Networking
## 3 The Attack Model and Detection Method
### The Attack Model of I-CIFPA  
Figure 1 shows the attack scenario of I-CIFPA in NDN networks and cloud infrastructure composed of various routing nodes, where \(R_{1}\) and \(R_{2}\) are gateway nodes and \(R_{3}\) is a backbone node. Before sending specific unpopular Interests to request corresponding content generated from the legitimate publisher, a CPA attacker determines which content is unpopular by tracking how often subscriber requests occur. As a result, the Content Stores (CS) in all routing nodes across the network are filled with less popular content, preventing popular content from replying to Interests and causing denial of service. Malicious Interests are intermittently sent by the I-CIFA attacker to request non-existent content carried in malicious data packets, and the collusive publisher produces malicious data packets in response.  
In Figure 1, the attack strength of CPA is \(E_{1}\), and the attack duration is \(L_{1}\). The attack strength, duration, and cycle of I-CIFA are \(E_{2}\), \(L_{2}\), and \(T\), respectively. To initiate a more destructive attack on NDN networks than I-CIFA and CPA, \(L_{1}\) is equal to the time of the attack phase of I-CIFA. Due to the new interval attack, I-CIFPA is established by initiating I-CIFA and CPA concurrently; thus, the attack intensity of I-CIFPA is \(E_{3}\approx E_{1}+E_{2}\), and the attack cycle and duration are the same as those of I-CIFA, i.e., \(T\) and \(L_{2}\), respectively. Each attack pulse interval of I-CIFPA is \((T-L_{2})\), and CPA still exists in the network at this time.  
Figure 1: Scenario of interval attacks.  
To characterize this attack model, we propose three key features: CacheHits, the number TimeOutIntrests and OutInterests. These features are designed to better capture attack behaviors and enhance detection performance.  
Consequently, I-CIFPA will cause the CS and PIT of all routing nodes to be occupied by malicious traffic in NDN networks, and subscribers will not receive a response from the publishers, leading to denial of service and seriously damaging the NDN networks.  
Figure 2 shows the architecture for addressing I-CIFPA, which has four steps.
# Bio-Inspired Algorithms for Efficient Clustering and Routing in Flying Ad Hoc Networks
## 4 HMAO Algorithms  
In this section, the HMAO-based clustering and routing for FANETs are discussed in detail. The comprehensive structure of HMAO ensures that the algorithm is robust and adaptable, thereby meeting the unique demands of FANETs while addressing the limitations of existing clustering and routing methods.
## 3 Results
### Data-Model Comparisons and Model Adjustment
#### 3.1.4 Soil Gaseous N Fluxes  
Daily soil N\({}_{2}\)O fluxes simulated with PnET showed seasonality, ranging from 30-50 \(\upmu\)g N m\({}^{-2}\) d\({}^{-1}\) to summer peaks of 200-300 \(\upmu\)g N m\({}^{-2}\) d\({}^{-1}\) with rain-related spikes on several occasions (Figure 5b). Excluding rain-related spikes, PnET N\({}_{2}\)O simulations showed a positive correlation with temperature, (\(r\) = 0.53, \(p\) < 0.01), resulting in high values in the summer; similarly, PSIM N\({}_{2}\)O simulations were not correlated with temperature (\(r\) = 0.04) and the timing of annual maximum values varied from year to year. Measured soil N\({}_{2}\)O fluxes showed much greater variation and no obvious seasonality, particularly during 2008-2012, and there was no correlation with temperature [50]. On occasions, negative N\({}_{2}\)O fluxes were measured, but the LandscapeDNDC version used could not simulate soil uptake of N\({}_{2}\)O. Peak effluxes of 500-1700 \(\upmu\)g N m\({}^{-2}\) d\({}^{-1}\) were measured (Figure 5b). Under wet soil conditions, both PnET and PSIM simulated short-lived spikes in N\({}_{2}\)O fluxes of 700-900 \(\upmu\)g N m\({}^{-2}\) d\({}^{-1}\) that did not necessarily coincide in time, magnitude or with measured spikes. For example, in early January 2014, PnET simulated N\({}_{2}\)O fluxes of 600 \(\upmu\)g N m\({}^{-2}\) d\({}^{-1}\), but only fluxes of 300 \(\upmu\)g N m\({}^{-2}\) d\({}^{-1}\) were simulated by PSIM. Annual N\({}_{2}\)O fluxes, adjusted to calendar year and estimated from approximately monthly measurements, ranged from 15.4 to 156 mg N m\({}^{-2}\) year\({}^{-1}\) during 2009-2011 [50] and 57.4 mg N m\({}^{-2}\) year\({}^{-1}\) in 2013 measured during this study. Fluxes simulated with PnET and PSIM for the same periods were less varied but within the range of 38.9-55.2 mg N m\({}^{-2}\) year\({}^{-1}\) and 36.9-52.3 mg N m\({}^{-2}\) year\({}^{-1}\), respectively (Table 6), and closer to the measured annual flux for 2013.  
Monthly measured N\({}_{2}\)O flux totals were compared with those simulated using PnET and PSIM modules with data from 2008-2012 analysed separately from 2013-2014 data (Table 5c). For both PnET and PSIM, the RMSE% values were large, and for 2008-2012, within the 95% confidence intervals of the measured means despite being >100%, due to larger variations in the fewer measured values than in 2013-2014 when the RMSE was significantly different from measurements. ME was negative and CD < 1 for 2013-2014 simulated N\({}_{2}\)O flux results from both models, suggesting that in this case, the measured data are better described by the mean. However, both simulations showed CD values > 1 for 2008-2012, which highlights the impact of the high degree of variability in soil N\({}_{2}\)O fluxes and the relative frequency of measurements. It also indicates there is considerable uncertainty in annual totals calculated from these measurements.
## 2 Analysis of Limitations of Existing Representative Methods
### An Analysis of the Security Vulnerabilities in the Ren Protocol  
[PERSON] et al. [27] proposed a lightweight two-party two-factor authentication protocol in 2024. The authors of this article designed a protocol applicable to IoT device-to-server and device-to-device communication, featuring lightweightness, anonymity, and high security. Through a security analysis, [PERSON] et al. concluded that their protocol has security features such as two-way authentication and user anonymity. However, based on our analysis, we conclude that the above protocol cannot withstand attacks based on known session-specific temporal information. A symbolic definition of the Ren protocol can be found in the literature [27]. The security analysis of the Ren protocol is as follows:  
If the attacker obtains the key information s during the execution of the Ren protocol in device-to-device communication, the session key \(sk\) can be calculated for each session using the following steps:  
1. Attacker \(C\) receives the message by listening to the public channel: \(T_{n}\), \(T_{i}\), \(N_{j}\);
2. Attacker \(C\) obtains \(n_{i}\) through the temporary session;
3. Attacker \(C\) calculates \(n_{i}N_{j}\) through the elliptic-curve scalar multiplication operation.
4. Attacker \(C\) obtains the \(sk\) by calculating \(sk=h(T_{i}||T_{j}||n_{i}N_{j})\).  
In summary, by leaking the temporary information \(n_{i}\) of a specific session, an attacker can calculate and obtain the session key of the current session using the above steps.