esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction
Building on this foundation, the current study aims to advance this research paradigm by integrating Geographic Information Systems (GIS) and machine learning technologies [31], drawing inspiration from hotspot detection clustering [32; 33], and applying Bayesian optimization algorithms [34; 35; 36; 37; 38; 39] alongside grid density clustering algorithms [27; 28; 40; 41; 42; 43; 27]. In an innovative approach, we propose to investigate the activity of second-hand housing transactions in Shenyang city as a case study. This research will identify active transaction areas and analyze their spatio-temporal characteristics to gain insights into the preferences of transaction groups and market dynamics. Ultimately, this study seeks to provide robust data support for decision-making and enhance the understanding of the operational trends in the real estate market. The study of second-hand house transaction activity presents a compelling avenue for in-depth research. A detailed analysis of transaction activity across various regions and time periods elucidates the dynamic fluctuations within the second-hand property market. This not only furnishes a scientific foundation for government bodies to devise effective real estate policies but also offers crucial insights for sellers to set reasonable property prices and for buyers to optimize the timing of their purchases, thereby facilitating market transactions. Furthermore, this research addresses existing gaps in academic studies concerning the activeness of second-hand housing transactions, establishing a robust theoretical base and literature framework for future investigations. The principal contributions of this study are outlined as follows:  
1. Innovations in perspective: This study pioneers research into the activity of second-hand housing transactions, augmenting the theoretical framework for managing second-hand housing transactions within the real estate market. It addresses research voids in the domain of second-hand housing transaction management and provides fresh perspectives and theoretical underpinnings for subsequent research in related areas. 2. Methodological innovation: Building upon the existing grid density clustering algorithm, this study introduces the RScan algorithm, which incorporates elements of Bayesian optimization. This algorithm enhances the technical capabilities for analyzing data from the second-hand housing market and fosters methodological advancements in the realm of real estate data analysis. 3. Interdisciplinary research: By integrating machine learning techniques with real estate studies, this research applies advanced algorithms and data analysis methods to the second-hand housing market. This approach not only expands the research boundaries within the real estate field but also introduces novel methodologies and perspectives for exploring this sector.
# A Review of Neurotransmitters Sensing Methods for Neuro-Engineering Research
## 2 Neurotransmitter Detection Methods
### High Performance Liquid Chromatography (HPLC)  
HPLC separates the different molecules in a mixture called the mobile phase, which is injected into a separation column of a diameter of typically 3.0-4.6 mm, initially filled with a stationary phase made of porous particles of 2.5-10 uM diameter [201,202]. The molecules are introduced in the mobile phase under high pressure and then move through the stationary phase. The Van Deemter equation describes the relationship between linear velocity (flow rate) and column height [201]. Depending on the molecules' properties, the interaction with the stationary phase is different: the molecules having a high affinity with the mobile phase migrate along the column faster, and are therefore the first to pass through it. The peak on the chromatograph is observed as shown in Figure 6, and the surface beneath the peak is proportional to the molecule's quantity [201,203]. HPLC is a very sensitive technique that allows the detection of two enantiomers. it was used to detect D-serine in the brain [46]. It is also often coupled with other techniques such as chemiluminescence. When coupled with mass spectrometry, it has been used to detect several neurotransmitters including GABA, pyroglutamic acid, asparagine, glutamic acid, glutamine, N-acetyl-L-aspartic acid, acetylcholine and its metabolite choline. The reported LOD for those neurotransmitters were 1.820, 0.046, 0.088, 1.930, 1.520, 1.050, 0.250, 0.012, and 0.620 nM, respectively.  
Simultaneous detection of monoamine and amino acid neurotransmitters in rat endrains was achieved by pre-column derivatization with high-performance liquid chromatographic fluorescence detection and mass spectrometric identification. Five molecules including L-glutamate, GABA, dopamine serotonin and 5-hydroxyindole acetic acid, which is a metabolite of serotonin, were separated and then detected with an LOD of 0.398-1.258 nM [204].  
Figure 5: Detection of dopamine by amperometry. Experimental set-up for amperometric recording of vesicular catecholamine release from a secretory cell using a carbon fiber microelectrode; (**A**) schematic drawing of the electrochemical reaction; (**B**) amperometric recording from a PC12 cell; (**C**) example of an amperometric current transient on an expanded time scale [200].
## 4 Conclusions  
A facile method was developed to make spherical carbon materials from waste polypropylene centrifuge tubes. The CVD method entails the use of a two-stage reactor to convert the polypropylene into propylene, and finally into carbon spheres (CSs). The methodology used is similar to that used to make similar carbons (solid carbon spheres, hollow carbon spheres, N-doped hollow carbon spheres) from gaseous and liquid hydrocarbon sources. The CSs were characterized by standard procedures (TEM, SEM, XPS, TGA, Raman spectroscopy). The SEM and TEM data revealed that the carbons  
Figure 6: Raman spectra for the SCSs, HCSs and NHCSs.  
Figure 7: XPS spectra of **(a)** SCSs, HCSs, and NHCSs and **(b)** nitrogen spectrum for the NHCSs.  
had diameters of about 1000 nm while Raman data revealed that the material had good graphitic characteristics (I\({}_{\text{D}}\)/I\({}_{\text{G}}\) < 1)). The carbons are pure materials, contain no metal catalyst residues (as found in CNTs), and potentially can be used in many outlets where CSs are commonly used (batteries, fuel cells, capacitors, and as catalyst supports). A simple procedure is thus available to convert PP waste into higher value materials as an alternative to their placement in landfill sites.  
The following are available online at [[http://www.mdpi.com/2076-3417/9/12/2451/s1](http://www.mdpi.com/2076-3417/9/12/2451/s1)]([http://www.mdpi.com/2076-3417/9/12/2451/s1](http://www.mdpi.com/2076-3417/9/12/2451/s1)), Figure S1: (A) Schematic of the apparatus (modified form from ref [21]), (B) Schematic view of the two stage based CVD furnace used for the synthesis of CSs from polypropylene (a) SCSs, (b) Si@CSs and (c) Si@NCSs. Figure S2: Diameter distribution of (a) SCSs, (b) HCSs and (c) and NHCSs. Figure S3: High resolution XPS data for (a) C1s and (b) O1s XPS spectra of HCS sample. Figure S4: High resolution XPS data for (a) C1s, (b) N1s and (c) O1s XPS spectra of NHCS sample. Figure S5: High resolution XPS data for (a) C1s and (b) O1s XPS spectra of SCS sample. Table S1: Summary of XPS data. Table S2: XPS component peak positions. Table S3: Summary of % concentration of all bonds in the samples.  
Conceptualization, P.T.; methodology, P.T., N.C.; formal analysis, P.T., N.C., S.D.; writing--original draft preparation, P.T., N.C.; writing--review and editing, P.T., N.C., S.D.; supervision, S.D., N.C.; funding acquisition, N.C.  
This research work was supported by the DST-NRF Centre of Excellence in Strong Materials (CoE-SM) at the University of the Witwatersrand. Authors are thankful to [PERSON] for assistance with collecting the Raman spectroscopy data and for analysis of the XPS data. The authors are also thankful to the MMU, University of the Witwatersrand for the use of the TEM and SEM characterization facilities.  
The authors declare no conflicts of interest.
# Safety Assessment of Microwave Breast Imaging: Heating Analysis on Digital Breast Phantoms
## 5 Conclusions  
The small temperature variations observed in this study support the conclusion that the exposure of human breast tissues to the electromagnetic field generated by the MI system is not harmful, making adverse thermal effects highly unlikely during exams. In the perspective that the receiving antenna, acting as a scatterer, significantly influences the EM field and SAR distribution, it would be relevant to explore alternative configurations for the receiving system, such as the adoption of metamaterials. Moreover, there is the possibility to optimize the performance of the device, for example, by modulating the input power when the signal-to-noise ratio is altered by the presence of a scatterer (as the receiving antenna) or if it is necessary to enhance output images. This is possible because of the large safety margin in the transmitted power level identified, taking into account the linear dependency of the temperature increase on the transmitted power level itself. Considering a potential patient-specific approach, the MI system can be leveraged to calculate differential power between input and output through signal analysis, enabling individualized SAR estimation within the breast. This methodology would allow safety assessments tailored to each patient's unique characteristics. In conclusion, microwave examination can be performed without harmful thermal effects due to EM field exposure.  
Conceptualization, A.R., L.Z., O.B., G.T. and A.A.; Methodology, A.R., L.Z. and A.A.; Validation, L.Z., O.B., G.T. and A.A.; Formal analysis, A.R., L.Z. and A.A.; Investigation, A.R., G.T. and A.A.; Resources, O.B. and G.T.; Data curation, A.R. and A.A.; Writing--original draft, A.R.; Writing--review & editing, L.Z., O.B., G.T. and A.A.; Visualization, A.R. and A.A.; Supervision, O.B. and A.A. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the funding received by the MammoScreen project, co-funded by the European Union's Horizon research and innovation framework programme, Grant agreement 101097079. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union, HaDEA or the UK R&I agency. Neither the European Union nor the granting authority can be held responsible for them.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original data presented in the study are openly available in Zenodo \"Dataset related to article \"Safety Assessment of Microwave Breast Imaging: Heating Analysis on Digital Breast Phantoms\" at DOI: 10.5281/zenodo.15194948.  
**Conflicts of Interest:** G.T. reports a relationship with Umbria Bioengineering Technologies that includes employment and equity or stocks. [PERSON] is shareholder of UBT--Umbria Bioengineering Technology. For all the other authors, there is no financial/personal interest or belief that could affect their objectivity.
## 2 Food Safety Management Systems around the World
### Managerial Systematic Approach to Food Safety
#### 2.1.3 Positive Food Safety Culture  
Food safety culture promotes food product and market safety in the food sector. Food safety culture impacts both developed and developing countries, but economic conditions, regulatory guidelines, and consumer awareness vary.  
Food safety legislation, enforcement procedures, and authorities to safeguard the public are normally in place in developed countries. However, poor infrastructure, poverty, weak food safety rules, and limited resources make it more difficult for developing nations to establish a food safety culture. Despite such constraints, food safety awareness in developing nations has led to the establishment of various efforts and programs to improve food safety culture.  
This study on the food safety culture element of FSMS and awareness in developing countries found that food safety culture is low due to low awareness and poor knowledge of food safety, inadequate infrastructure and regulatory standards, challenges implementing food safety guidelines, and insufficient financial resources to develop a robust food safety culture. However, developed countries have built robust infrastructure, resilient regulations, and enforcement mechanisms to control food safety concerns and promote a food safety culture.  
Moreover, UNDP, WFP, WHO, and FAO initiatives have promoted food safety culture in developing countries and improved food safety management systems. These programs train, advise, and fund developing nations to improve food safety [7; 37; 38; 39; 40; 41].
###### Abstract  
Speech enhancement is one of the most important fields in audio and speech signal processing. The speech enhancement methods are divided into the single and multi-channel algorithms. The multi-channel methods increase the speech enhancement performance by providing more information with the use of more microphones. In addition, spatial aliasing is one of the destructive factors in speech enhancement strategies. In this article, we first propose a uniform circular nested microphone array (CNMA) for data recording. The microphone array increases the accuracy of the speech processing methods by increasing the information. Moreover, the proposed nested structure eliminates the spatial aliasing between microphone signals. The circular shape in the proposed nested microphone array implements the speech enhancement algorithm with the same probability for the speakers in all directions. In addition, the speech signal information is different in frequency bands, where the sub-band processing is proposed by the use of the analysis filter bank. The frequency resolution is increased in low frequency components by implementing the proposed filter bank. Then, the affine projection algorithm (APA) is implemented as an adaptive filter on sub-bands that were obtained by the proposed nested microphone array and analysis filter bank. This algorithm adaptively enhances the noisy speech signal. Next, the synthesis filters are implemented for reconstructing the enhanced speech signal. The proposed circular nested microphone array in combination with the sub-band affine projection algorithm (CNMA-SBAPA) is compared with the least mean square (LMS), recursive least square (RLS), traditional APA, distributed multichannel Wiener filter (DB-MWF), and multichannel nonnegative matrix factorization-minimum variance distortionless response (MNMF-MVDR) in terms of the segmental signal-to-noise ratio (SegSNR), perceptual evaluation of speech quality (PESQ), mean opinion score (MOS), short-time objective intelligibility (STOI), and speed of convergence on real and simulated data for white and colored noises. In all scenarios, the proposed method has high accuracy at different levels and noise types by the lower distortion in comparison with other works and, furthermore, the speed of convergence is higher than the compared researches.  
Keywords:speech enhancement; adaptive filter; microphone array; sub-band processing; filter bank
# Enhancing PAPR and Throughput for DFT-s-OFDM System Using FTN and IOTA Filtering
## 5 Conclusions  
In order to meet the new requirements of waveforms applied in high frequency communication, where ultra high-speed transmission is one of the vital targets, high spectrum efficiency with reliability is required in the designed waveforms. Based on the OFDM waveform which is basically used in 4G/5G, DFT spreading and FTN signaling are utilized to make the waveform have lower PAPR and higher spectral efficiency, respectively. To further enhance the throughput performance of communication systems, FTN-DFT-s-OFDM waveform based on an IOTA filter is proposed in this paper. The good time-frequency focusing characteristic of the IOTA filter enables the ISI reduction, and thus the transmission performance of the waveform is improved. On the receiver side, we apply an FDE receiver to demodulate the signal, with a complexity of \(O(NlogN+N)\). Simulation results have shown that the proposed scheme can offer joint performance gain in terms of PAPR reduction, BER and throughput improvement. Specifically, 3.5 dB gain in PAPR and 50% gain in throughput can be achieved compared with the existing waveforms.  
For future work, improvements can be further achieved in the waveform design and receiver design. Spectral efficiency and PAPR performance enhancement can be explored based on other waveforms, such as constant envelope OFDM, filter bank of multi-carrier, orthogonal time frequency space, etc. Moreover, low-complexity iterative design to compact the ISI and ICI is also a promising direction. The state-of-the-art artificial  
Figure 15: Throughput performance of IOTA and RRC with \(\alpha=0.5\).  
intelligence techniques can also be exploited to enhance the waveform design in an end-to-end fashion [10; 34].  
Conceptualization, X.Z.; methodology, X.Z.; software, J.P. and H.W.; validation, X.Z., J.P. and H.W.; formal analysis, J.P.; investigation, X.Z. and J.P.; resources, X.L.; data curation, J.P. and N.Y.; writing--original draft preparation, H.W.; writing--review and editing, X.Z. and J.P.; visualization, J.P.; supervision, H.W., X.L. and N.Y.; project administration, X.Z.; funding acquisition, X.L. and N.Y. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China under grants 62101048, 61971038, 61620106001, and 62001030.  
Not applicable.  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} OFDM & Orthogonal frequency division multiplexing \\ DFT & Discrete Fourier transformation \\ DFT-s & Discrete Fourier transformation spreading \\ ISI & Inter-symbol interference \\ ICI & Inter-channel interference \\ FTN & Faster-than-Nyquist \\ IOTA & Isotropic orthogonal transform algorithm \\ PAPR & Peak-to-average power ratio \\ BER & Bit error rate \\ CP & Cyclic prefix \\ MCS & Modulation coding scheme \\ AWGN & Additive white Gaussian noise \\ EGF & Extended Gaussian filter \\ FDE & Frequency domain equalization \\ MMSE & Minimum mean square error \\ \end{tabular}
# Generative Neural Networks for Addressing the Bioequivalence of Highly Variable Drugs
## 5 Conclusions  
This study introduced the application of artificial intelligence generative algorithms, specifically the Wasserstein Generative Adversarial Networks, in the BE assessment of highly variable drugs. To demonstrate the benefits of using WGANs to reduce the required sample size, Monte Carlo simulations of BE studies were conducted, and various scenarios were tested across a range of within-subject variability values, sample sizes, and data augmentation scales (2\(\times\) and 3\(\times\) the original sample size). The WGAN method was compared against the scaled EMA and FDA approaches for highly variable drugs. In all cases, the WGAN approach showed a favorable performance. It should be mentioned that even though no scaling was incorporated in the WGAN method (the classic 80-125% limits have always been used), its performance was at least equal or even better than the scaled EMA/FDA approaches. When WGAN synthetization was used to augment the original sample size by 3\(\times\), the performance further improved, highlighting its effectiveness in minimizing sample size requirements. We give significant proof of the method robustness by demonstrating that WGANs can reliably recreate and even increase BE acceptance under these extreme conditions, by simultaneously preserving specificity. Studying a less variable medicine would not have put as much strain on the algorithm or regulatory frameworks, nor would it have demonstrated its ability to minimize sample numbers, eliminate complex replication designs, and speed approval processes for the most difficult BE scenarios. Apart from reducing the required sample size in BE studies of highly variable drugs, the WGAN approach also eliminates the need for replicate or semi-replicate designs, which are complex, costly, time-consuming, and prone to high dropout rates. Once validated and supported by a regulatory framework, it can efficiently deliver these benefits. Even though this study is only the first step towards using WGANs in the BE assessment of highly variable drugs, it clearly shows that once specific criteria are set by regulatory authorities, a new avenue will open for the future of BE assessment.  
Conceptualization, V.D.K.; methodology, V.D.K.; software, A.N.; validation, A.N.; normalisation, A.N.; investigation, A.N.; resources, V.D.K.; data curation, A.N.; writing--original draft preparation, A.N.; writing--review and editing, V.D.K.; visualization, A.N. and V.D.K.; supervision, V.D.K.; project administration, V.D.K. All authors have read and agreed to the published version of the manuscript.
## 4 Design Methodology  
In WPT, the usual technique to design a rectifier begins by selecting the appropriate active device, typically a diode. Based on their bias techniques, rectifier diodes can be classified into two main clusters, namely zero-biased diode configurations and non-zero-biased configurations [22]. Non-zero-biased configurations require an external source to operate, which is not appropriate in harvesting energy and wireless power transfer applications. Among the zero-bias diodes, P-N junction and Schottky barrier devices are the most widely used.  
A comparison of their I-V characteristics (Figure 5) shows that the Schottky diode can turn ON at lower voltages (0.1 V-0.4 V) than can the P-N junction (e.g., 0.7 V for silicon). In addition, Schottky barrier diodes have faster switching capabilities and a much higher saturation current [22; 23]. Therefore, the Schottky barrier diode is suitable for wireless power transfer and harvesting energy systems.  
There are several commercially available Schottky diodes that can be used for a rectification process at the desired frequency operation (915 MHz), such as the HSMS-28 xx family series and the SMS-76 xx series [21; 24], which can handle different input power levels. The HSMS2850 diode can work at low levels of input powers, i.e., less than 0 dBm (with a turn-on voltage of 150 mV and a breakdown voltage of 3.8 V), whereas the HSMS2860 diode is aimed at operating at higher levels of input powers, i.e., 0 to 20 dBm (with a turn-on voltage of 350 mV and a breakdown voltage of 7 V) [3].  
When the diode device operates as a rectifier, the maximum output DC voltage is restricted by the voltage breakdown, \(V_{br}\), and can be expressed as [21]  
\[V_{o,\;DC}=\frac{V_{br}}{2}. \tag{4}\]  
Note that, due to output DC signal saturation, the input AC signal amplitude is limited. Therefore, the diode breakdown voltage determines the maximum peak voltage of the input waveform. As stated in [21], for a given load \(R_{L}\), the maximum output DC power is determined by  
\[P_{max,\;DC}=\frac{V_{br}}{4R_{L}}. \tag{5}\]  
Figure 5: I-V characteristics of P-N junction (\(pn\)) and Schottky barrier diodes (\(SB\)).