esa-sceva/satcom-chunk-collection huggingface dataset:
# Technique Evolutions for Microorganism Detection in Complex Samples: A Review
## 2 Current Detection Methods
### Methods Based on Growth Monitoring
#### 2.1.5 Turbidimetry  
The more microorganisms there are, the more opaque the medium is. This change in optical density can be measured by a spectrophotometer at a wavelength usually between 420 and 615 nm to detect microorganism growth. This method requires a calibration step to be quantitative. Applied to the monitoring of a cell therapy product, measuring the optical density spectrum allows to distinguish between an increase in optical density due to cell growth or an increase due to contamination [19]. Recent works have also shown the possibility of developing portable systems suitable for in situ measurements [20; 21].  
To be detectable, these techniques often require the presence of a minimum number of target cells to obtain a measurable signal, which implies enrichment.  
The choice of the method is guided by the suspected microorganisms. Indeed, the sensitivity of each method depends on the type of microorganisms, whether they produce gas, heat, or significantly change the electrical impedance or the opacity of the medium. All these methods are only semi-quantitative because the relationship between the measured physical cue (light emission, pressure, heat, and impedance) and the number of microorganisms depend on the type of microorganism and experimental conditions. Therefore, the initial number of microorganisms cannot always be accurately quantified. In addition, the complexity of analytical medium can lead to a bias in the results. As these methods rely on the growth of microorganisms, they are limited to culturable bacteria and the detection time is limited by the growth step, even if considerable improvements have been achieved over the years, with or without labelling as detailed in [22; 23].
# Hybrid Satellite-Terrestrial Networks toward 6G: Key Technologies and Open Issues
## 7 Conclusions  
This survey has provided a thorough examination of the current state-of-the-art in the field of HSTNs. We have presented various HSTN network architectures and provided an in-depth overview of current work in cooperative and cognitive HSTN network architectures. NOMA and beamforming have been reviewed. There is also an overview of the work done in physical\"layer security of various HSTN network architectures. Various potential applications of HSTN have been presented. In the end, open issues have been discussed to conclude our work.  
Conceptualization Y.C. and S.B.R.T.; writing--original draft preparation, S.B.R.T.; writing--review and editing, A.A.K., S.L. and Y.C.; supervision, Y.C., S.L. and W.F.; administration, Y.C. and W.F. All authors have read and agreed to the published version of the manuscript.  
This work was supported in part by the National Natural Science Foundation of China under Grant 61922049 and Grant 61941104; in part by King Abdullah University of Science and Technology Research Funding (KRF) under Award No. ORA-2021-CRG10-4696 and by EC H2020 DAWN4 loE-Data Aware Wireless Network for Internet-of-Everything under Grant 778305.  
Not applicable.  
The authors declare no conflict of interest.
# Human Activity Recognition Based on Point Clouds from Millimeter-Wave Radar
## 4 Results
### Performance Comparison by Quantization Bit Formats  
A lightweight model design and a low-power design are essential for the practical use of HAR systems. For this purpose, the proposed HAR system was implemented on the Xilinx Zynq UltraScale+ ZCU104 (Xilinx, Santa Clara, CA, USA) for a low-power design. To implement a classification network on the FPGA part of the ZCU104 platform, a register transfer level (RTL) design is required, which includes the process of converting the system implemented in a floating-point format to a fixed-point format. In RTL design, the more bits that express a number, the larger the range of numbers that can be expressed; this improves accuracy but requires a large memory for system storage and operation. To  
Figure 5: Training and test loss curve and accuracy curve: (a) Training and test loss curve; (b) Training and test accuracy curve.  
Figure 6: Confusion matrix.  
find a tradeoff between accuracy and memory usage, we compared the HAR accuracy based on the bit formats of the classification network, as shown in Table 6. The Brevitas library provided by Xilinx was used to quantize the input data, weight, bias, and activation functions [32]. As shown in Table 6, the accuracy decreased by less than 1% from 32 bits to 4 bits; however, at 2 bits the accuracy degradation was approximately 13% compared with other bit formats. Therefore, 4 bit quantization was selected as the best tradeoff between accuracy and memory usage for the classification network and was implemented on the FPGA.
# Flexible Antennas: A Review
## 7 Flexible Antennas for Ingestible Application  
Telecommunications and microelectronics have contributed a number of benefits in the field of medical applications. Ingestible medical devices (IMDs) are significant components for IoT applications in medical sectors. As a result, for monitoring devices and drug delivery system and monitoring internal condition of the patient, special types of flexible antennas are needed.  
Wireless IMDs have been widely used for diagnostic purposes, in particular for visualization of gastrointestinal (GI) [225]. Because the digestive organs in the GI tract have different electrical properties, the antennas for these applications need to have broadband characteristics. In recent years, there are various antennas for wireless systems have been reported. However, heavy metals are mainly used to fabricate these antennas, which are potentially hazardous for humans' health when the capsules fracture. Thus, water antennas appear safer in diagnosis and treatment. Wireless capsule endoscopy (WCE) is a technique for medical applications that records images of the digestive tract [226] (Figure 14). This method has various advantages, comparing to traditional methods, such as esophagagostroudoenoscopy or colonoscopy. WCE is painless and non-invasive. WCE system contains an antenna that offers wide bandwidth to scan different areas of the small intestine.  
An omnidirectional conformal small UWB loop antenna operating at 433 MHz was proposed for capsule endoscope systems involving real-time video image transmission from inside to outside body [226]. The proposed antenna was fabricated on Preperm 255 substrate using copper, and it maintained the desired performance at varying implant depths and locations of different tissue types.  
A compact (30 mm\({}^{3}\)), conformal differentially fed antenna on ultrathin polyimide substrate (Figure 15) at 915 MHz ISM (902-928 MHz) band for monitoring in body core temperature and a biomedical application was presented in an earlier report [227]. The integrated capsule system was  
Figure 14: Antenna for ingestible application. (**a**) Fabricated capsule antenna and (**b**) measurement setup using Agilent e5063A vector network analyzer [226].  
experimented in a cubic homogeneous muscle phantom. Smaller capsule with differential network concept, the absence of shorting pins brought desirable advantages such as the insensitivity on antenna performance tuning, easy fabrication, and the reduction of effects on neighboring circuits. Recently, an electrically small wideband antenna on silicon substrate targeting wireless capsule endoscopy (WCE) application operating at 915 Hz was presented in an earlier report [228] (Figure 16). The antenna performance was satisfactory with different tissues due to its wide bandwidth, and it was also tested with liquid mixture mimicking the colon phantom at 915 MHz. This work paves the way for improved ingestible WCE by supporting higher data-rate radio links.
## 2 Methods
### Decision Trees
To avoid overfitting, which is one of the most common drawbacks of decision trees, it automatically prunes the tree. CHAID also produces a number of rules, whereby each has a confidence level (accuracy). The confidence level is defined as the ratio of records having the specific value for the target variable to the given values for the independent variables. Similarly to the CART model, the same values were used for maximum tree depth, minimum records in parent branch, minimum records in child branch, combining rule for continues target, and the number of component models for boosting and/or bagging to develop the CHAID model. However, more settings were used to develop the CHAID decision tree model compared to the CART model. To fine-tune the CHAID tree-building process, five parameters were used: (1) significance level for splitting, (2) significance level for merging, (3) adjustment of significance values technique, (4) minimum change in expected cell frequencies, and (5) maximum iterations for convergence. The significance levels for splitting and merging were set as 0.05. To control the false-positive error rate, an adjustment of significance values technique known as the \"Boferroni method\" was used. In order to converge on the optimal estimate used in the chi-square test for a specific split, the minimum change in expected cell frequencies was used and set as 0.001. The last parameter specified the maximum number of iterations before stopping, whether convergence occurred or not. This parameter was set to 0.001. Decision trees are regarded as unstable and high-variance models, which causes the trees to be prone to different generalization behavior with small changes in the training data [85]. The RF method can be used to avoid the abovementioned drawbacks. RF is a relatively new tree-based method and was developed by [PERSON] [86]. RF is an ensemble technique that produces more accurate prediction compared to other tree-based methods by merging a huge number of decision trees. RF uses a bagging technique to build each ensemble from different datasets. The bagging technique randomly selects from the space of decision trees and creates almost identical (low-diversity) predictions.
## 2 Related Works
### Coreference Resolution  
There is a problem that some reviews present users' opinions about more than one real-world entity, for example, reports about the use of multiple medications that may have different effects. Therefore, in order to distinguish mentions of different drugs, diseases, etc., it would be useful to detect which mentions, on the contrary, refer to the same entities, and which coreference resolution does.  
For the English language, there are several corpora for coreference resolution, such as CoNLL-2012 [29] or GAP [30], and even a corpus of pharmacovigilance records with ADR annotations that includes coreference annotation (PHAEDRA) [31]. For Russian texts, the coreference problem is underrepresented in the literature. Currently, there are only two corpora with coreference annotations for the Russian language: RuCor [32] and corpus from the shared task AnCor-2019 [33]. The latter is a continuation and extension of the first.  
As for the methods for coreference resolution, the state-of-the-art approach is based on a neural network trained end-to-end to solve two tasks at the same time: mention extraction  
\begin{table}
\begin{tabular}{l c c c c c c c} \hline
**Corpus** & **CADEC** & **TA** & **TT** & **TP** & **N2C2** & **PSYAR** & **RuDRec** \\ \hline Total number of mentions & 6318 & 1122 & 899 & 475 & 1579 & 3543 & 720 \\ \hline Multi-word (\%) & 72.4 & 0.47 & 40 & 46.7 & 42 & 78 & 54 \\ \hline Single-word (\%) & 27.6 & 0.53 & 60 & 53.3 & 58 & 22 & 46 \\ \hline Discontinuous, non-overlapping (\%) & 1.3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \hline Continuous, non-overlapping (\%) & 84 & 100 & 98 & 96.8 & 95 & 100 & 100 \\ \hline Discontinuous, overlapping (\%) & 9.3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \hline Continuous, overlapping (\%) & 5.3 & 0 & 2 & 3.2 & 5 & 0 & 0 \\ \hline \(\text{Saturation}=\dfrac{\text{total ADR}}{\text{total words in corpus}}\) & 53.38 & NA & NA & 16.5 & 1.35 & 39.17 & 10.61 \\ \hline total ADR & 0.69 & 0.72 & 0.67 & 0.47 & 0.02 & 0.70 & 0.41 \\ \hline total ADR & 22.97 & 7.1 & 1.91 & 0.49 & 0.25 & 0.70 & 0.01 \\ \hline number of indication, reason, etc. & & & & & & & \\ \hline Accuracy & 70.6 [14] & 61.1 [15] & 64.8 [16] & 73.6 [17] & 55.8 [18] & 71.1 (see Appendix A) & 60.4 [10] \\ \hline Accuracy metric & f1-e & f1-am & f1-am & f1-cs & f1-r & f1-e & f1-e \\ \hline \end{tabular}
\end{table}
Table 1: Comparison of structural characteristics of existing corpora with respect to ADR mentions, and the accuracy of ADR detection in these corpora. Abbreviations of corpora names: TA—Twitter Annotated Corpus, TT—TwiMED Twitter, TP—TwiMED PubMed, N2C2—n2c2-2018. Abbreviations of accuracy metrics: f1-e—f1-exact, f1-am—f1-approximate match, f1-r—f1-relaxed, f1-cs—sentence classification on ADR entity presence; NA—data not available for download and analysis.  
and relation extraction. This approach was firstly introduced in [34] and has been used in several papers [35; 36; 37; 38; 39], with some modifications to get higher scores on the coreference corpus CoNLL-2012 [29].
## 1 Introduction
The performance of OFDM with wavelet transform is better than that of the fast Fourier transform because it does not require the insertion of a cyclic prefix [13; 14; 15; 16; 17; 18; 19]. Studies of MIMO diversity with wavelet transform have shown that it can improve the performance in terms of BER compared with SISO channel diversity, and it has been suggested to be able to meet the demands of wireless networks [20; 21; 22; 23]. Therefore, an MIMO diversity technique with OFDM can be used to improve the performance in terms of BER [24; 25].
# Autonomic Network Management and Cross-Layer Optimization in Software Defined Radio Environments
## 3 Autonomic Framework for Network Management and Cross-Layer Optimization in SDR
### Anmo-Sdr Architecture  
ANMO-SDR follows a hybrid architecture paradigm, according to which, self-organization and self-optimization procedures are running locally on the MN considering local scope tasks, while, accordingly, the tasks with wider scope (global network view) are being managed by the SDN controller, a central managing authority on the network side (i.e., at the core network). The hybrid architecture paradigm combines the benefits of the decentralized network management paradigm handling effectively the complexity overheads, avoiding the single point of failure (characteristic of the classical centralized approaches), incorporating also centralized control capabilities. The main architectural elements and the interactions between them are shown in Figure 3 (while a more detailed diagram of the ANMO-SDR functionality is presented in Figure 4).  
The proposed hybrid architecture extends the design directions of GANA [29; 30], which provided the fundamental principles and guidelines towards ANM objectives, without providing any specific solution or implementation. More precisely, GANA introduced ANM components for different abstraction levels of functionality, which follow the principles of hierarchical, peering, and sibling relations among others.  
ANMO-SDR promotes self-management, as well as self- and environment-awareness (in comparison to GANA), giving to the MN the ability to control its own context. Thus, it enables the MN to determine the appropriate time to execute respective actions, promoting local optimum, enabling it to assign the best available channel according to the desired operational goals (self-optimization). Specifically, decentralized cooperative spectrum sensing is performed, by utilizing SDR. More precisely, the information collected by each MN (i.e., SU) concerning the detection of active transmissions of PUs and other SUs in its sensing radius, is subsequently exchanged with neighboring SUs. On the other hand, the central SDN-controller is responsible for performing centralized control related to global tasks (global optimum), such as synchronization of nodes, determination of employed VUF and the coordination of distributed computations, e.g., the coordination of the computation of the VUF.  
Figure 3: Hybrid ANMO-SDR architecture.
# Covert Channel Communication as an Emerging Security Threat in 2.5D/3D Integrated Systems
## 1 Introduction
Physical covert channel attacks have been studied more recently, with an acoustic channel [30] introduced in 2014, and power/electromagnetic covert channels explored in 2020 [31; 32]. Although there have been previous survey papers on covert channels, these works typically summarize covert channels as a whole (including network- and host-based channels), rather than focusing on physical covert channels [5; 11; 22]. Additionally, the discussion on physical covert channels is typically confined to air-gap systems instead of emerging threat models, such as covert channels between separate cores of a multi-core processor or even within the same core. The primary contributions of this paper are as follows:  
* A summary of the general threat model and methodology involved in using a covert channel to leak secret information is provided. * A detailed background on different types of physical covert channel attacks is provided. * Modern countermeasures against physical covert channel attacks are discussed. * A perspective on covert channels in emerging 2.5D/3D systems is provided. * A novel attack model for a power covert channel that exploits the relatively accessible interposer layer in 2.5D systems is proposed. The rest of this paper is organized as follows. Section 2 provides a background on the procedure of establishing a covert channel and describes the threat model assumed. Section 3 gives a survey of different types of physical covert channels and the existing state-of-the-art. Section 4 discusses various countermeasures to prevent and detect covert channels. Section 5 provides a perspective on upcoming challenges with covert channels in 2.5D/3D systems including covert channel detection. Finally Section 6 concludes the paper. Figure 1: Classification of various covert channels.
## 3 Results and Discussions
### Measurement of the Electrical Properties for Forming Sintering for Different Systems  
Figure 8 shows the effect of forming sintering on the Q-value for different systems. It is seen that the Q-value increases when the frequency increases. The most significant result is for recycled batteries with a composition of Mn\({}_{0.34}\)Zn\({}_{0.12}\)O(Fe\({}_{2}\)O\({}_{3}\))\({}_{0.54}\). The next most significant result is for Ni\({}_{0.5}\)Zn\({}_{0.5}\)Fe\({}_{2}\)O\({}_{4}\). The least significant result is for a composition of Cu\({}_{0.7}\)Zn\({}_{0.3}\)Fe\({}_{2}\)O\({}_{4}\). For this composition, the Q-value does not increase when the frequency is greater than 70 kHz. Figure 9 shows the effect of forming sintering on the \(\mu_{0}\) value for different systems. The coil has an insufficient number of turns so there is a small and negative inductive value and \(\mu_{0}\) is negative. It is seen that the \(\mu_{0}\) value decreases when the frequency is increased. For recycled batteries with a composition of Mn\({}_{0.34}\)Zn\({}_{0.12}\)O(Fe\({}_{2}\)O\({}_{3}\))\({}_{0.54}\) and a composition of [Ni\({}_{0.5}\)Zn\({}_{0.5}\)]Fe\({}_{2}\)O\({}_{4}\), the decrease is more significant. The least significant decrease occurs for a composition of [Cu\({}_{0.7}\)Zn\({}_{0.3}\)]Fe\({}_{2}\)O\({}_{4}\). The diagram showing the effect of forming sintering on the R-value for different systems shows the resistance value of the coil, instead of the resistance value of ferrite itself. It is seen that the only composition for which the value of the resistance increases when frequency is increased is [Ni\({}_{0.5}\)Zn\({}_{0.5}\)]Fe\({}_{2}\)O\({}_{4}\). For compositions [Cu\({}_{0.7}\)Zn\({}_{0.3}\)]Fe\({}_{2}\)O\({}_{4}\) and Mn\({}_{0.34}\)Zn\({}_{0.12}\)O(Fe\({}_{2}\)O\({}_{3}\))\({}_{0.54}\), an increase in frequency produces an initial increase in resistance and then a decrease.  
Figure 8: The effect of forming sintering on the Q-value for different systems.
# Post-Earthquake Damage Inspection of Wood-Frame Buildings by a Polarimetric GB-SAR System
## 4 Discussions
### Feasibility and Further Improvements  
To judge whether a building is safe to enter and reoccupy is of great concern after a disastrous earthquake. Compared with buildings made of concrete materials, wood-frame buildings have received little attention from the perspective of damage inspection and evaluation. Although the presented technique can help a civil engineer see the wooden structures through the covering wall finishes, it can only be used as a supplement, rather than a substitution of the visual inspection [7].  
Further research efforts from three aspects should be poured to improve the developed GB-SAR system and the imaging algorithm. Firstly, the current GB-SAR system, based on a 2D scanner and a VNA, works in an inefficient way and the 80 cm \(\times\) 80 cm survey consumes more than eight hours. This is impractical for field applications. Development of a multi-input multi-output (MIMO) antenna array system would be desired. A MIMO array can acquire 3D data over a swath by a single scan and meets the survey speed requirement [30]. Secondly, the variation of electromagnetic wave propagation  
Figure 10: RGB image generated from the 2D survey on the Type II wall specimen in Figure 1b at a depth of 2.3 cm from the wall surface.  
velocity in wood, air, and other media has not been considered in the SAR processing. A reverse time migration (RTM) algorithm [31], which can incorporate a detailed dielectric model of the wooden wall based on the design, should be investigated in the future. Thirdly, besides Pauli decomposition, other polarimetric representation methods--e.g., alpha-entropy decomposition [25] and Yamaguchi four-component decomposition [32]--should be tested to further explore the quantitative information of the damaged wooden structures from the polarimetric GB-SAR dataset.