esa-sceva/satcom-chunk-collection huggingface dataset:
# Energy-Efficient Clustering Scheme for Flying Ad-Hoc Networks Using an Optimized LEACH Protocol
## 5 Experimental Results, Analysis, and Discussion
### Consistency in Number of Cluster Head  
The number of cluster heads highly impacts the energy efficiency of the protocol. If the count of cluster heads is small, the data transmission period of sensor nodes to CH would be too long, leading to additional energy consumption. Excess data transmission by the cluster will also lead to overconsumption of energy. The overall network load increased as the number of cluster heads grew. Even with this, the total energy consumption per round of networks had also been raised. It degrades the network fusion efficiency of data, and the life of the network shrinks.  
Figure 7 exhibits the details about the LEACH Protocol, the LEACH-C Protocol, and our proposed EE-LEACH protocol headcounts per round. The variation in the cluster head number can be seen in the figure below as the LEACH Protocol has high fluctuation in the cluster head number due to the cluster headcount being randomly dependent on the threshold function model, which has high randomness. From Figure 7, we can see that the cluster headcount fluctuates in the range of \(4\leq\mathrm{k}\leq 16\) in the LEACH protocol, \(2\leq\mathrm{k}\leq 14\) in LEACH-C, while in the proposed protocol it is \(3\leq\mathrm{k}\leq 10\), which is the most optimal. The proposed protocol calculates the optimal cluster headcount based on the threshold that includes some energy parameters, thereby helping in reducing the randomness of cluster headcounts.  
Figure 6: Number of clusters vs. number of nodes.  
Figure 7: Number of cluster heads vs. number of rounds.  
If a significant number of dead nodes are present in the network, the overall capacity of the cluster will be decreased accordingly to balance the energy consumption of the network.
###### Abstract  
Detecting leakage using a point cloud acquired by mobile laser scanning (MLS) presents significant challenges, particularly from within three-dimensional space. These challenges primarily arise from the prevalence of noise in tunnel point clouds and the difficulty in accurately capturing the three-dimensional morphological characteristics of leakage patterns. To address these limitations, this study proposes a classification method based on XGBoost classifier, integrating both intensity and geometric features. The proposed methodology comprises the following steps: First, a RANSAC algorithm is employed to filter out noise from tunnel objects, such as facilities, tracks, and bolt holes, which exhibit intensity values similar to leakage. Next, intensity features are extracted to facilitate the initial separation of leakage regions from the tunnel lining. Subsequently, geometric features derived from the k neighborhood are incorporated to complement the intensity features, enabling more effective segmentation of leakage from the lining structures. The optimal neighborhood scale is determined by selecting the scale that yields the highest F\({}_{1-\text{score}}\) for leakage across various multiple evaluated scales. Finally, the XGBoost classifier is applied to the binary classification to distinguish leakage from tunnel lining. Experimental results demonstrate that the integration of geometric features significantly enhances leakage detection accuracy, achieving an F\({}_{1-\text{score}}\) of 91.18% and 97.84% on two evaluated datasets, respectively. The consistent performance across four heterogeneous datasets indicates the robust generalization capability of the proposed methodology. Comparative analysis further shows that XGBoost outperforms other classifiers, such as Random Forest, AdaBoost, LightGBM, and CatBoost, in terms of balance of accuracy and computational efficiency. Moreover, compared to deep learning models, including PointNet, PointNet++, and DGCNN, the proposed method demonstrates superior performance in both detection accuracy and computational efficiency.  
point cloud; leakage detection; intensity features; geometric features; XGBoost +
Footnote †: journal:
# Effect of Local Gas Flow in Full Penetration Laser Beam Welding with High Welding Speeds
## 1 Introduction
Besides the general pressure increase, a compressive force is also exerted in the field of interaction. \[p_{dyn_{gas}}=\frac{1}{2}\rho_{gas}v_{gas}^{2} \tag{4}\]  
The effect of a lateral shielding gas flow at deep penetration laser beam welding of 1.4301 (X5 CrNi18-10, AISI304) at a welding speed of 1 m/min was characterized by [22]. By using the gas flow, a reduced number of pores as well as a decreasing spatter formation could be determined. Based on a high flow rate of 20.4 L/min, an enlargement of the keyhole aperture was observed. Thereby, the change in the outgassing conditions of the metal vapor flow was stated as the reason for the spatter reduction. Further investigations gained comparable results for welding speeds up to 5 m/min [23]. By varying the flow orientation (leading and trailing positioning), no effect on the welding process could be noticed. In contrast, a positive effect of a trailing flow orientation was shown in [24], which was attributed to a reduced interaction of the gas flow with the outgassing metal vapor flow. Latest findings are proving a stabilizing effect on the keyhole formation for welding of martensitic steel in lap joints at a welding speed of 1.5 m/min [25]. By further investigations, the effect of a local gas supply was simulated by using computational fluid dynamics numerical analysis. According to the experimental investigations, an enlargement of the keyhole could also be observed [26]. Moreover, using the gas flow, the flow pattern in the rear-sided melt pool was characterized by less recirculation. The more uniform melt propagation results in an elongation of the melt pool [27]. Depending on flow rate, a reduction in keyhole fluctuations could be noticed also. Furthermore, simulations for deep penetration welding of aluminum AA 5083 could figure out a destabilizing effect of a leading flow orientation [28]. Thereby, the effect was attributed to an increasing upward momentum of the molten material. However, the investigations have been carried out up to a welding speed of 5 m/min. A study about the influence of a local gas flow at welding speeds above 5 m/min has not been sufficiently investigated so far. Based on the latest investigations on partial penetration welding [29; 30], this publication focusses on the influence of local gas flows on full penetration welding of high-alloy steel AISI304 (1.4301, X5 CrNi18-10) at welding speeds from 8 m/min to 16 m/min. For this purpose, a novel experimental setup was developed, in order to characterize the effect of the gas flow on the stability of the keyhole and melt pool dynamics. Depending on flow rate, the influence of an affected pressure balance was investigated regarding the gas flow conditions as well as the change in spatter formation. Finally, the results are condensed in a description of the acting effect mechanism.
## 2 Materials and Methods
### Data Processing
#### 2.3.3 Analysis of NEP Change Trend  
In order to quantitatively describe the change law of _NEP_ in the Yangtze River Delta region in the past 20 years, unitary linear regression analysis method was used to analyze the change trend of the _NEP_ of each pixel in this region from 2000 to 2019. The trend line of a single pixel is simulated by unitary linear regression from the pixel values of that pixel within 20 years [29]. The calculation formula for the slope of the trend line is:  
\[\theta_{slope}=\frac{n\times\sum_{i=1}^{n}i\times NEP_{i}-\sum_{i=1}^{n}i \sum_{i=1}^{n}NEP_{i}}{n\times\sum_{i=1}^{n}i^{2}-\left(\sum_{i=1}^{n}i\right)^ {2}} \tag{8}\]  
In Formula (8), \(\theta_{slope}\) is the slope of the trend line; \(i\) is the serial number of the year 1-20; \(NEP_{i}\) represents the _NEP_ value of the \(i\) year. It reflects the overall change trend of the _NEP_ of each pixel during these 20 years. If \(\theta_{slope}>0\), it means that the change trend of _NEP_ is increasing, otherwise it is decreasing.
# Applications of Wireless Sensor Networks: An Up-to-Date Survey
## 2 Main WSN Applications
### Flora and Fauna Applications
#### 2.4.2 Crop Monitoring  
Within the agriculture domain, the preservation of the crops plays a vital role. In order to provide a better environment for the crops, various WSNs applications can be implemented. Crop irrigation and fertilization are some examples of the applications that have been designed as described below.  
Hidro Bus is a system described in [29]. It is a remote controlled, automatic irrigation system for large areas of land applied at Jumilla (Murcia, Spain). The system divides the deployment area into seven sub-regions, where each has a control sector for monitoring and controlling. The control sectors communicate with each other and the central controller via WLAN network.  
An automated fertilizer applicator system is built in [30], which consists of three modules, the input, the decision support, and the output modules. The input module can provide to the Decision Support System (DSS) module, GPS and real time sensor data by utilizing bluetooth technology. With these data the DSS is able to calculate quantity, application rate, and the spread pattern of the fertilizer that the output module will provide to the crops.  
The authors of [31] developed and integrated an optimal fertilization decision support system using a wireless sensor LAN, IEEE 802.11 protocol (Wi-Fi) and a GIS analysis server. Sensor nodes were used to acquire vital data in real time such as soil moisture, conductivity, temperature, etc. Also, the system used B/S a (browser/server) structure mode to provide high interactivity. Also, a GIS analysis server was used to interpolate the data from small experimental plots to larger plots to exploit data  
Figure 12: The subcategories of flora and fauna applications of WSNs and the types of the sensors used in them.  
reduction for energy conservation. An overview of the overall system architecture is illustrated in Figure 13.  
Similarly, in [32] a scheme based on the collaboration of an integrated system for an automated irrigation management with an advanced novel routing protocol for WSNs, was proposed. This system aims at efficiently managing water supply in cultivated fields in an automated way. The system takes into consideration the historical data and the change in the climate values to calculate the quantity of water that is needed for irrigation.
## 1 Introduction
In [50], a modified equivalent squint range model (MESRM) was proposed for high-resolution spaceborne SAR, where a quadratic polynomial is employed to represent the curved trajectory of the LEO satellite. In [51], an equivalent acceleration range model (EARM) was proposed for sliding-spotlight mode, followed by a velocity-scaling imaging algorithm. The squinted sliding-spotlight SAR data focusing was studied in [52] and a processing scheme using 2-D baseband azimuth scaling was put forward. However, these range models and imaging methods are proposed for monostatic spaceborne SAR, which cannot be applied to GEO-LEO BiSAR in sliding-spotlight mode. Based on the above analysis, the current range models and imaging methods for GEO-BiSAR and monostatic sliding-spotlight SAR cannot be applied to GEO-LEO BiSAR imaging in sliding-spotlight mode. Therefore, this article is the first attempt to address the main issues in sliding-spotlight GEO-LEO BiSAR and therefore proposes a novel frequency-domain imaging method. The main contributions and novelty of this paper can be summarized as follows. * A novel equivalent bistatic range model based on circular orbit trajectory ESRM, namely BiCoT-ESRM, is proposed to accurately represent the range history of GEO-LEO BiSAR in sliding-spotlight mode. BiCoT-ESRM comprehensively considers the two major problems, i.e., curved trajectory of LEO receiver and'stop-and-go' assumption error. * Based on BiCoT-ESRM, the precise 2-D spectrum is derived, and a frequency-domain imaging method is put forward to achieve accurate focusing for sliding-spotlight GEO-LEO BiSAR. * The modified azimuth preprocessing can remove the total Doppler aliasing caused by spatial variance of Doppler centroid and beam steering in sliding-spotlight GEO-LEO BiSAR. Moreover, the azimuth variance of motion parameters due to curved trajectory can be simultaneously eliminated by the proposed azimuth trajectory scaling (ATS). * This experiment provides a new approach for designing the equivalent experiments to verify the theoretical studies and imaging methods related to GEO monostatic/bistatic SAR, which can be a worthwhile reference for researchers engaged in relevant studies. The rest of the paper is organized as follows. Section 2 formulates the equivalent range model for GEO-LEO BiSAR in sliding-spotlight mode. Section 3 provides the detailed derivations of the proposed frequency-domain imaging method. In Section 4, simulation and real data-processing results are given to verify the effectiveness of the proposed method. Conclusions are finally drawn in Section 5.
###### Abstract  
The quality of a received signal is one of the most important factors to be considered when designing a receiver for visible light communication (VLC) systems. Therefore, it is necessary to evaluate the robustness of the VLC receiver circuit in low-signal-to-noise ratio (SNR) communication. The SNR is the quantity characterized by the ratio of the signal power to the noise power of the received signal. The noise generates an offset voltage and distorts the desired signal waveform. Thus, a low SNR makes it difficult to retrieve the data. Among the sources of noise, ambient light has the most negative impact on the VLC data signal. Therefore, the novel receiver proposed by us acts as an ambient light rejection circuit. As our average-voltage tracking circuit is insensitive to the sunlight and indoor fluorescent light, our design could be a solution to enhance the performance of low-SNR VLC systems. Several experiments are conducted using light of same intensity, but with different distances and semi-angles. Experimental results demonstrate that robust interference rejection is possible to send an error-free communication with an On-Off Keying modulation base on microcontroller up to 1 Mbps at an SNR of \(-2.7\) dB.  
visible light communication; ambient light; average-voltage tracking; light interference; photodiode receiver; signal-to-noise ratio +
Footnote †: journal: Applied Physics Letters
## 2 Materials and Methods
### Study Data
#### 2.2.3 Elevation Data  
The digital elevation model (DEM) data were obtained from the Resource and Environmental Science Data Center of the Chinese Academy of Sciences. This dataset is based on the latest SRTM V4.1 (Shuttle Radar Topography Mission, SRTM) data and was resampled to generate a DEM with a spatial resolution of 500 m to ensure uniform spatial resolution for calculations and analysis.  
Figure 1: Topographic conditions and sub-basin distribution in the YRB. A\(-\)M represent 13 sub-basins of the YRB, which are as follows: the Jinsha River Basin; the mountainous areas in the upper reaches of Dadu River and Jialing River; the confluence area of Sichuan Basin; the main stream area in the upper\(-\)middle reaches of the Yangtze River; the Wujiang River Basin; the middle reaches of the Yangtze River; the confluence area of Nanyang Basin; the Jianghan\(-\)Dongting Lake Plain; the Dongting Lake Basin; the mountainous area of Ganjiang River Basin; the Poyang Lake Plain; the confluence area of Chao Lake and the plain along Wanjiang River; and the confluence area of the Yangtze River Delta.
# Internet of Things Geosensor Network for Cost-Effective Landslide Early Warning Systems
## 2 Landslide Early Warning Systems  
Since their origin in the 1980s, numerous Landslide Early Warning Systems (LEWS) have been designed and implemented. Some of them focus on a regional, national or global scale (so called \"territorial systems\"), while other systems focus only on a single slope or landslide (local LEWS). [PERSON] et al. (2020) and [PERSON] et al. (2018) highlight a number of territorial systems and present the challenges and possibilities that are inherent to LEWS of this scale [22; 23]. Because of the scale, for these types of LEWS only a generalized warning for a region is possible, while localized early warning of a specific area or slope is not possible.  
Local LEWS usually include multiple sensors on site, cover a much smaller area (<0.1 km\({}^{2}\) to 1 km\({}^{2}\)) [24] and, most importantly, usually are installed in areas where slow movements have already been detected and thus the exact location of a potential landslide is already known. [PERSON] et al. (2019) reviewed several local LEWS around the world and found that the primary parameter used for warning is displacement, followed by the trigger--mostly rainfall--and groundwater parameters. This makes sense since rainfall is the most important triggering factor for landslide early warning [25]. By [PERSON] et al. (2019), also a comparison of the sensor systems in use is made, with the most important monitoring systems being classical geotechnical methods such as inclinometers and piezometers, as well as geophysical (geophones), geodetic (GPS) and remote sensing methods. Yet, such studies rarely take costs into account, which is one of the most important parameters when working in low-income countries [26; 24]. Low-Cost monitoring systems until now are mostly limited to GPS networks, acoustic emissions or radio communication [27; 28; 29; 30; 31].
# An Adaptive Hierarchical Hybrid Multicast Based on Information-Centric Networking
## 6 Conclusions  
In this paper, we propose AHHM to improve the scalability of multicast. AHHM assigns a unique global MGEID to each multicast group. By adaptively using the stateless mode on routers with more forwarding states, the proposed AHHM can effectively balance the forwarding overhead and multicast forwarding states. By balancing the destinations information to different MJNs, AHHM alleviates the problems of ingress router overload and packet redundancy faced by BIER. In order to optimize the multicast transmission path, we used the NRS to maintain the mapping between each MGEID and MJNs and designed a minimum cost MJN selection strategy to select a suitable MJN for each receiver to join. We conducted a series of experiments to evaluate the performance of AHHM. The experiments show that AHHM can well balance the control overhead, multicast forwarding state, and link load. Compared with SSM, AHHM can greatly reduce multicast forwarding states and link load. Compared with BIER, AHHM increases some multicast forwarding states but greatly reduces the control overhead and link load.  
Conceptualization, B.L. and J.W.; methodology, B.L. and J.W.; software, validation, investigation B.L.; writing--original draft preparation, B.L.; writing--review and editing, B.L., J.W., X.Z., J.Y. and L.H.; supervision, J.W. and X.Z.; project administration, J.W.; funding acquisition, J.W. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Strategic Leadership Project of the Chinese Academy of Sciences: SEANET Technology Standardization Research System Development (Project No. XDC02070100).  
Not applicable.  
The authors declare no conflict of interest.
# The Development of Key Technologies in Applications of Vessels Connected to the Internet
## 2 Internet of Vessels Architecture
### The Technical Architecture of the Networks Layer
#### 2.3.2 Satellite Centric Mode Networks  
The satellite network is one of the best ways to solve the ship communications during navigations. However, the communication bandwidth of the satellite network limits the development of applying satellite communication between the satellites and the ground, as well as the satellites and the ocean. Recently lots of progress has been made to improve the low-bandwidth communication in satellite positioning and satellite communication. Now the United States, Europe, Russia and China have the ability to realize global communications. The network coverage of the International maritime satellite is shown in Figure 6[24].  
Figure 6: The network coverage of the International maritime satellite.  
At present, the main functions of the global navigation satellite system are navigation and measurement. In future, it can be used in the IoV system. The global positioning system (GPS) of the USA consists of 24 satellites (21 of the satellites are working, 3 of the satellites are standby) which are used for military and civil purposes. The Galileo system of the European Space Agency has 30 satellites and is used for civil purposes. Similarly, Russia developed a set of positioning systems, the precision of which is limited to 10 m. The Beidou navigation satellite system from China has 5 geostationary orbit satellites and 30 non-geo satellites [25]. China has carried out lots of studies and practices on the IoV by the Beidou navigation satellite system. Based on the Beidou navigation satellite system (BDS), automatic identification system (AIS), geographic information system (GIS), the internet and mobiles, China is developing a kind of IoV system called Beidou IoV to realize integrated service for the sea, the sky and the ground. The Beidou IoV system covers the eastern coastal areas of China and provides ship monitoring, short message communication and fishing-vessels port management [26].
# A Network-Based Model for Optimization of Container Location Assignment at Inland Terminals
###### Abstract  
The development of inland terminals helps seaports mitigate inevitable storage capacity problems, extending their gravitational field and strengthening their competitive advantage. Optimizing the container storage, efficiency, and productivity of seaports and inland terminals is becoming increasingly important. The present paper develops a network-based mathematical model to optimize the location assignment of inbound containers at inland terminals. The model's assumptions are based on the analysis of criteria at representative European inland terminals, and the model aims to reduce unproductive manipulations. The present study is one of the few to develop a single model that integrates all important criteria for container location assignment, including a container's dimensions, its occupancy, cargo type, the container's owner, and distance to the final user. These criteria are important for the terminal operator so that they can determine container locations in a way that minimizes unproductive manipulations. Data from a single inland terminal were used to validate the model within the FlexSim CT simulation environment. Our results suggest that the model can reduce unproductive manipulations and associated costs at inland terminals.  
Keywords: inland terminal; container storage optimization; container location assignment; graph theory; simulation modelling; consistent flow +
Footnote †: journal: _Applied Sciences_
# The Impact of Distributed Energy Storage on Distribution and Transmission Networks' Power Quality
## 4 Results  
### Main Results of Variant Power Quality Performance Analysis  
The relative effect of the integrated ESS architecture and topology on the benchmark network is shown in Table 3. The distributed ESS integrated architecture achieved a better average improvement in voltage magnitude and voltage angle deviation, as can be seen.  
Figure 3: Graph indicating the effect of DN-D_LVN Variant on (**a**) the voltage magnitude compensation; (**b**) the voltage angle deviation compensation.  
Equally notable is that the performance also infers that the highest power quality performing variants wherein ESS is integrated within the distribution network topology when compared with their counterparts integrating ESS within the transmission network topology.