esa-sceva/satcom-chunk-collection huggingface dataset:
# Gold Nanofilm-Coated Porous Silicon as Surface-Enhanced Raman Scattering Substrate
## 4 Conclusions  
In conclusion, a facile technique for the preparation of a highly sensitive SERS substrate is proposed using PSi template fabricated by a single step electrochemical etching process and followed by the e-beam evaporation of Au. Au nanofilm with suitable crystalline particle size was coated over PSi template by PVD technique and yielded a homogenous layer of Au nanostructures that were highly packed and agglomerated with rough surfaces. A similar strategy was followed to prepare Si-Au SERS substrate using flat Si as the template substrate. The SERS activity of the fabricated platforms were tested using standard Raman tag, R6G dye molecules. The result showed better SERS activity for the PSi-Au composite than the control Si-Au substrate. This enhanced SERS activity is due to the morphology, size, arrangement, and agglomeration of Au nanostructures onto PSi templates, which induced higher number of electromagnetic hot spots at the inter-particle junctions. Moreover, thickness of the Au layer also played a significant role in the SERS effect. The highest SERS output was achieved for 7 nm film thickness and the intensity declined with further increase of the film thickness. Here, a straightforward, facile technique for the fabrication of PSi-Au film was established, which consequently proved an excellent SERS substrate; therefore, it may have great potential in different SERS application, including sensing of different biomolecules, in which case, a stable and reproducible SERS platform is a pre-requisite.  
Conceptualization, K.L.T. and V.K.H.; methodology, K.L.T. and V.K.H.; software, K.L.T. and I.K.; validation, C.M.C. and V.K.H.; formal analysis, K.L.T. and I.K.; investigation, I.K. and V.K.H.; resources, C.M.C. and V.K.H.; data curation, K.L.T. and I.K.; writing--original draft preparation, I.K. and V.K.H.; writing--review and editing, S.H., W.A.Y. and V.K.H.; visualization, C.M.C.; supervision, V.K.H.; project administration, C.M.C. and V.K.H.; funding acquisition, C.M.C. and V.K.H.  
This research was funded by Taichung Veterans General Hospital/National Chi Nan University Joint Research Program, grant number TCVGH-NCNU-1087902; 2017 SATU Joint Research Scheme, and the Ministry of Science and Technology, Taiwan, grant number MOST-107-2221-E-260-016-MY3.  
This study was supported by Taichung Veterans General Hospital/National Chi Nan University Joint Research Program (TCVGH-NCNU-1087902), 2017 SATU Joint Research Scheme, and the Ministry of Science and Technology (MOST), Taiwan, under the project number MOST-107-2221-E-260-016-MY3.  
The authors declare no conflict of interest.
# An Energy Efficient Modulation Scheme for Body-Centric Terahertz (THz) Nanonetworks +
## 3 Trade-Off between Energy Consumption and Data Rate
### Energy Consumption  
Let \(E_{pulse}\) denote the pulse energy. The average energy required to transmit \(k\) bits by using TS-OOK is given by \(E(M)=\frac{kE_{pulse}}{2}\), since transmission of pulses and silences is equiprobable. However, this is not the case in the proposed modulation, with its average energy per bit depending on the modulation order. More specifically, in SPVD, the average energy per symbol is always \(E_{s}=E_{pulse}\), due to the fact that only one pulse is transmitted for each symbol. Accordingly, the energy consumption of SPVD per bit is \(\frac{E_{pulse}}{k}\). Thus, for \(k>2\) the proposed modulation has lower energy consumption compared to TS-OOK for the transmission of \(k\) bits, which correspond to one symbol for the case of SPVD. These remarks can be also verified from Figure 3, which presents a comparison of the two modulations, regarding the mean energy consumption versus \(k\), assuming normalized pulse energy \(E_{pulse}=1\). In addition, as it can be observed, the mean energy consumption per bit of the proposed modulation is a decreasing and concave function with respect to \(k\).
## 4 Random Linear Network Coding for Mobile Video Delivery
### RLNC: Where Should It Be?
#### 4.1.2 RLNC Solutions in Radio Access Network  
As an alternative to integration at the higher layers, RLNC sublayer could be integrated where the network reliability is critical: within RAN protocols. This solution could be equally applied for unicast and multicast/broadcast mobile video delivery, as it is triggered over the packets delivered between eNB and UE(s) either via unicast (PDSCH) or multicast (MTCH) transport channels.  
The solution for RLNC within the MAC layer of LTE RAN protocol stack has been investigated in detail in [67]. The proposed MAC-RLNC solution, integrated as the upper sublayer within MAC protocol, adopts the built-in flexibility of RLC protocol (segmentation and concatenation) to define the desired size of the source block that will be provided to the MAC-RLNC sublayer in the form of RLC packet data unit (PDU). From each received RLC PDU, MAC-RLNC produces a stream of carefully-sized fixed-length coded packet which are encapsulated in consecutive MAC frames and delivered via underlying PHY TB containers to the receiver side. The rationale behind MAC-RLNC was to apply rateless RLNC concept and convert RLC PDU transmission into a \"fluid\" delivery of coded packets flexible to fit PHY TB containers of different sizes. This way, MAC-RLNC would essentially replace MAC-based HARQ protocol, as instead of sending HARQ retransmissions, the transmitter simply continues to send a new set of coded packets, until receiver acknowledges it has received full-rank set and is able to recover the RLC PDU (see Figure 5). Performance of such a MAC-RLNC scheme has been investigated in terms of video delivery over LTE [68]. Integration of RLNC into RAN protocols opens a novel possibilities for joint optimization of RLNC and resource allocation for both unicast and multicast/broadcast services, the topic we present in more details in the following subsection.
# A Systematic Survey on 5G and 6G Security Considerations, Challenges, Trends, and Research Areas
## 3 5G Security Architecture: A Systematic Approach
### Radio Access Network
#### 3.2.7 Massive MIMO  
Multiple Input, Multiple Output (MIMO) is a technology where multiple antennas are simultaneously utilized in both the transmitter and receiver to enable concurrent communication across multiple independent propagation paths. This can be leveraged to increase overall throughput for a single user, to concurrently communicate with multiple users, or to perform beamforming to more tightly control propagation aspects. MIMO technology falls within the realm of smart antenna technology. 5G technology can employ a vast array of antennas at base stations, allowing them to simultaneously serve multiple users on the same radio module or radio bearer (RB). Compared to traditional communication methods, massive MIMO enhances spectrum efficiency, minimizes user interference, and boosts energy efficiency, resulting in higher system throughput [81; 82; 83; 84; 53; 85]. The author that presents the previous claim in [86] also shares a more in-depth analysis of how the usage of MIMO in 5G opens another vector of security requirements. Namely, MIMO security algorithms produce a large amount of noise if spatial redundancy is not sufficient, eavesdroppers can obtain information through users with poor connection, and theoretical reception indicators for MIMO security algorithms do not currently match measurable indicators. The author completed a survey of the literature on MIMO security and conducted a quantitative assessment of MIMO security posture within a 5G network. Simulations in the paper evaluated and predicted the situational level of active attack and passive eavesdropping via a dynamic and real-time prediction. Since the proposed evidence-based algorithm performs well in predicting the security situation of devices in a MIMO system, the results can be used to adapt security measures to specific security situations. Active eavesdropping detection and avoidance are furthermore discussed in [87] with promising findings in derivations of achievable secrecy rates and the probabilistic detection of eavesdroppers on a network. The findings show that with a higher number of base station antennas, there is a higher probability of detecting an eavesdropper. The detection of active attacks on MIMO channels is discussed in [88], and the use of NOMA (Non-Orthogonal Multiple Access) with a hierarchical security model is discussed in [89].
## 3 Results and Discussion
### Effects of STL Addition on BT VMs
#### 3.2.5 OAV Analysis
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Name**} & **OTs** & **Aroma** & & **OAV** \\  & & **(ng/kg) A** & **Characteristics B** & **BT** & **BoS** & **STL** \\ \hline
13 & Hexanal & 10 & Fresh, green, fruity, swaved & 39.553 \(\pm\) 2.031 * & 22.318 \(\pm\) 8.438 b & 4.222 \(\pm\) 0.743 c \\ \hline
14 & (E)-2-hexanal & 13 & Green, banana, fatty, chesey & 93.353 \(\pm\) 2.995 * & 50.848 \(\pm\) 8.973 b & 3.267 \(\pm\) 0.646 c \\ \hline
16 & (E)-3-hexen-1-ol & 70 & Green, floral, oily, earthy & 11.061 \(\pm\) 0.892 b & 13.756 \(\pm\) 3.272 * & 0.823 \(\pm\) 0.162 c \\ \hline
19 & 1-hexanol & 500 & Ethereal, fruity, sweet, green & 0.978 \(\pm\) 0.038 b & 1.502 \(\pm\) 0.383 * & 0.040 \(\pm\) 0.010 c \\ \hline
26 & Benzaldehyde & 3 & Almond, caramel flavor & 390.533 \(\pm\) 34.965 b & 265.668 \(\pm\) 77.463 c & 515.784 \(\pm\) 36.185 * \\ \hline
28 & 1-octen-3-ol & 1 & Mushroom, green, oily & 169.18 \(\pm\) 9.072 c & 836.963 \(\pm\) 130.754 b & 1366.109 \(\pm\) 150.229 * \\ \hline
42 & 2-ethyl-1-hexanol & 270,000 & Citrus, fresh, floral, oily, sweet & 0.000 \(\pm\) 0.000 b & 0.000 \(\pm\) 0.000 b & 0.008 \(\pm\) 0.001 * \\ \hline
46 & Benzeneacetaldehyde & 4 & Wood, sweet, honey & 2289.967 \(\pm\) 158.374 a & 2125.484 \(\pm\) 188.8664 a & 139.284 \(\pm\) 23.827 b \\ \hline
48 & Isophorone & 2 & Wood, sweet, green, tobacco & 20.439 \(\pm\) 0.611 b & 12.556 \(\pm\) 0.807 c & 1211.616 \(\pm\) 126.046 * \\ \hline
57 & Linalool & 6 & Citrus, floral, swaved, woody & 374.445 \(\pm\) 19.218 * & 371.961 \(\pm\) 22.024 a & 15.894 \(\pm\) 3.487 b \\ \hline
59 & Phenylethyl alcohol & 750 & Sweet, floral, fresh & 2.380 \(\pm\) 0.19 a & 2.516 \(\pm\) 0.296 a & 0.615 \(\pm\) 0.152 b \\ \hline
70 &
\begin{tabular}{c} Linalool oxide \\ (pyranoid) \\ \end{tabular} & 320 & Floral, honey & 0.600 \(\pm\) 0.054 b & 0.545 \(\pm\) 0.085 b & 24.518 \(\pm\) 1.156 a \\ \hline
72 &
\begin{tabular}{c} 2-methoxy-3-(2-methylpropyl)- \\ pyrazine \\ \end{tabular} & 0.015 & Green, pea flavor, galanum & 186.988 \(\pm\) 8.858 b & 205.408 \(\pm\) 6.493 b & 40984.985 \(\pm\) 1488.308 * \\ \hline
75 & 1-dodecanol & 0.066 & Waxy, floral, honey, coconut & 15.519 \(\pm\) 13.684 b & 20.815 \(\pm\) 18.117 b & 30780.489 \(\pm\) 2020.076 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Aroma characteristics and odor activity value (OAV) of key differential volatile metabolites in BT, BoS, and STL.
###### Abstract  
Satellite data play a major role in supporting knowledge about fire severity by delivering rapid information to map fire-damaged areas in a precise and prompt way. The high availability of free medium-high spatial resolution optical satellite data, offered by the Copernicus Programme, has enabled the development of more detailed post-fire mapping. This research study deals with the exploitation of Sentinel-2 time series to map burned areas, taking advantages from the high revisit frequency and improved spatial and spectral resolution of the MSI optical sensor. A novel procedure is here presented to produce medium-high spatial resolution burned area mapping using dense Sentinel-2 time series with no a priori knowledge about wildfire occurrence or burned areas spatial distribution. The proposed methodology is founded on a threshold-based classification based on empirical observations that discovers wildfire fingerprints on vegetation cover by means of an abrupt change detection procedure. Effectiveness of the procedure in mapping medium-high spatial resolution burned areas at the national level was demonstrated for a case study on the 2017 Italy wildfires. Thematic maps generated under the Copernicus Emergency Management Service were used as reference products to assess the accuracy of the results. Multitemporal series of three different spectral indices, describing wildfire disturbance, were used to identify burned areas and compared to identify their performances in terms of spectral separability. Result showed a total burned area for the Italian country in the year 2017 of around 1400 km\({}^{2}\), with the proposed methodology generating a commission error of around 25% and an omission error of around 40%. Results demonstrate how the proposed procedure allows for the medium-high resolution mapping of burned areas, offering a benchmark for the development of new operational downstreaming services at the national level based on Copernicus data for the systematic monitoring of wildfires.  
f 2019 11 622 2019 14 March 2019 11 622 2019 11 622 2019 14 March 2019
# RFID Authentication System Based on User Biometric Information +
## 3 Design Background and Overview
### System Architecture  
In this part, we briefly describe the four steps for implementing the RF-Ubia system.  
_Hardware Settings._ In order to realize the password function of RF-Ubia, we need to arrange nine RFID tags into a 3 \(\times\) 3 layout first. The tag array is then fixed to prevent signal changes caused by the relative movement of the tags from affecting the user authentication results.  
_Tag Identification._ The reader sends a signal to activate the nine tags in the array, then carries out a preliminary identification according to the EPC [30] of the tag. After the reader obtains the signal of the legitimate tag, it waits for the user to touch the corresponding tag and collects the signal data.  
_Data Processing._ The purpose of this step is to process the tag data acquired by the reader to eliminate the inverted \(\pi\) phenomenon and periodic signal surround (i.e., phase unwrapping) of the tag phase. Then, we extract the characteristic information we need and identify the password sequence entered by the user.  
_User Authentication._ The system first determine whether the identified password sequence is a valid password. If the password sequence entered by the user is indeed registered in the system, the second stage of verification will be performed. In the second stage, the system verifies whether the user is legitimate to prevent an illegal attacker from stealing the password sequence of the legitimate users.
## 4 Simulation Results and Analysis
### The No-Load Condition of a Given 1 Rad Step Signal  
When a 1 rad step signal is applied, the position curve is illustrated in Figure 8. Analyzing the curves in the graphs reveals that the controller reaches the specified position in approximately 0.0429 s despite there being noticeable jitter here, and the continuity is not optimal. In contrast, the RBF-ADRC controller can achieve the desired position in about 0.0339 s, providing a speed improvement of roughly 0.01 s over the original. Furthermore, FRBF-ADRC outperforms the previous controllers, reaching the specified position in approximately 0.0189 s, resulting in an additional speed enhancement of around 0.02 s.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Argument** & **Value/Unit** \\ \hline Resistance \(R_{s}\) & 2.6 \(\Omega\) \\ Inductance \(L_{d}\), \(L_{q}\) & 0.00736 H \\ Moment of inertia \(J\) & 0.00102 kg\(\cdot\)m\({}^{2}\) \\ Flux linkage \(\psi_{t}\) & 0.246 wb \\ Number of poles \(n_{p}\) & 2 \\ Polar distance \(\tau\) & 0.012 m \\ Quality \(m\) & 3 kg \\ \hline \hline \end{tabular}
\end{table}
Table 2: Parameters of the motor.
## 3 Results
### GC-MS Analysis of the Chemical Composition of SJW EO
[25] analysed EOs from the aerial parts of two _Hypericum_ species from Uzbekistan and determined that the main components of the EO of _Hypericum_ L. were \(\alpha\)-pinene (11.2%), spathulenol (7.2%), p-cymene (6.1%), acetophenone (4.8%) and carvacrol (4.7%), while the EO of _H. perforatum_ L. contained as the main components \(\beta\)-caryophyllene (11.7%), caryophyllene oxide (6.3%), spathulenol (6.0%) and \(\alpha\)-pinene (5.0%). The analyses of SJW EOs from Serbia revealed that sesquiterpenes exhibited the highest concentration (44.4%), \begin{table}
\begin{tabular}{c c} \hline \hline
**Groups of Chemical Compounds** & **\% of Total Ion Current** \\ \hline Alkanes & 16.92 \(\pm\) 0.13 \\ Alkylbenzene & 2.05 \(\pm\) 0.33 \\ Monoterpenes & 43.55 \(\pm\) 0.35 \\ _Monoterpene hydrocarbons_ & 41.04 \(\pm\) 0.51 \\ _Oxygenated monoterpenes_ & 2.51 \(\pm\) 0.12 \\ Sesquiiterpenes & 36.81 \(\pm\) 0.37 \\ _Sesquiterpene hydrocarbons_ & 27.29 \(\pm\) 0.24 \\ _Oxygenated sesquiterpenes_ & 9.52 \(\pm\) 0.38 \\ Total identified & 99.33 \(\pm\) 0.90 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Groups of chemical compounds identified in Bulgarian St John’s Wort (_H. perforatum_ L.) essential oil by GC–MS analysis. as the cryophyllene oxide (15.3%) was the major component [26]. Different chemotypes of the EO of 10 wild-growing populations of _H. perforatum_ L. in Eastern Lithuania have been isolated and studied by [PERSON] et al. [27]. The samples were collected at full flowering and analysed by GC-MS. The authors identified 46 constituents in the investigated oils. The EOs were classified into three groups as follows: \(\beta\)-caryophyllene (4 samples, 10.5-19.1%), cryophyllene oxide (4 samples, 13.3-35.8%) and germacrene D (2 samples, 16.1-31.5%).
# Biosynthesis Progress of High-Energy-Density Liquid Fuels Derived from Terpenes
## 4 Strategies for Constructing Efficient Microbial Cell Factories for Terepenes
### Optimizing Metabolic Pathways
#### 4.2.1 Optimization of MEP and MVA Pathways
The expression levels of the three loci were ranked as B \(>\) M \(>\) T, resulting in a 5-fold increase in the yield of squalene [124]. Additionally, the accumulation of IPP and FPP in the terpene synthesis pathway is toxic to cells [125]. The dynamic regulation of the exogenous MVA pathway with promoter engineering or inducible control of the promoter is an effective strategy. For example, by regulating the MVA pathway dynamically, epi-isozizaene, pentalenene and \(\alpha\)-isocompene achieved titers of 727.9 mg/L, 780.3 mg/L and 77.5 mg/L, respectively, in _E. coli_ DH1 [38]. IPP and DMAPP are derived from the MVA pathway in yeast, which has stronger tolerance to cytotoxic intermediates such as MVA and IPP [125]. Studies have shown that HMGR is a rate-limiting enzyme in yeast, and overexpression of HMGR can effectively increase the production of farnesol, nerolidol and epi-cedrol [126; 127]. In addition to HMGR, increasing the expression of other genes in the MVA pathway can also enhance the production of sesquiterpenes. For example, the production of farnesol reached 1.68 g/L by expressing mutated farnesyl diphosphate synthase (ERG20), truncated HMGR and isopentenyl diphosphate isomerase (IDI1) with a galactose-inducible promoter [128]. In another study, the dynamic regulation of ERG20 expression was achieved by replacing the ERG20 promoter and controlling the addition of carbon sources, resulting in a 3.4-fold increase in farnesol production [73]. Furthermore, researchers obtained an FPP overexpression chassis named JCR27 by overexpressing all genes in the MVA pathway in _S. cerevisiae_ and achieved the synthesis of multiple sesquiterpenes, including (-)-eremophilene, epi-isozizaene, protoilludene, pentalenene and \(\alpha\)-farnesene, with the highest yield reaching 38.8 g/L [32; 60; 129]. Except for _S. cerevisiae_, other yeast species including _Y. lipolytica_ and _R. toruloides_ are also excellent hosts for synthesizing terpen. For instance, in _Y. lipolytica_, the yield of limonene reached 917.7 mg/L by expressing GPPS and limonene synthase, downregulating ERG20 and overexpressing tHMG1 and IDI1 [130]. [PERSON] et al. achieved the efficient synthesis of bisabolene in _Y. lipolytica_ by introducing an exogenous MVA pathway and efflux pumps [78]. In _R. toruloides_, high expression of the MVA pathway genes increased the production of bisabolene to 2.6 g/L [50].
## 2 Materials and Methods
Figure 4: The evolution of the shielding element concept, from loaded receiving dipole to lossy dipole: (**a**)—dipole loaded with single resistor, (**b**)—dipole loaded with set of resistors, (**c**)—dipole made of lossy material. Figure 5: Geometry of four wire array. The lowest value of power density level (0.47 W/m\({}^{2}\)) was obtained for the length of wires equal to 47 mm and conductivity of 500 S/m. The power density distribution (in logarithmic scale with reference to 10 W/m\({}^{2}\)) obtained for this case is presented in Figure 6 for the \(x\)-\(z\) plane and in Figure 7 for the \(x\)-\(y\) plane (\(z=0\)). The color level in the figures corresponds to the power density. Red indicates the region where the power density is not less than 10 W/m\({}^{2}\), while dark blue indicates places where the power density is below \(-\)35 dB, referring to 10 W/m\({}^{2}\) (that is 3.2 mW/m\({}^{2}\)). This color scale is also used in later figures that present power density. This simple configuration of conducting wires reduces locally the power density from 10 to 0.47 W/m\({}^{2}\). It was used as the initial design of the wire-based head shield because it can be easily manufactured with textile technologies such as printing with conductive ink or embroidery with conductive yarns and then can be incorporated into the clothes. In Figure 8, the simplified model of the wire-based head shield is presented. This is formed with the set of vertically aligned wires of length equal to 47 mm and conductivity of 500 S/m. The wires have the same diameter as in the four-element case (1 mm) and are located at the same distance (10 mm apart from each other). This is a simplified model \begin{table}
\begin{tabular}{c c c} \hline \hline \(L\) **(mm)** & \(\sigma\) **(S/m)** & \(S\) **(W/m\({}^{2}\))** \\ \hline
30 & 200 & 6.5 \\
30 & 500 & 7.2 \\
30 & 1000 & 7.6 \\
47 & 200 & 0.68 \\
**47** & **500** & **0.47** \\
47 & 1000 & 0.52 \\
60 & 200 & 3.03 \\
60 & 500 & 3.33 \\
60 & 1000 & 3.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Power density at the test point (\(x=5\) mm, \(y=0\), \(z=0\)) located behind the four wire array. Figure 6: Power density distribution in the \(x-z\) (\(y=0\)) plane for the four wire array (the length of wires: 47 mm, conductivity: 500 S/m). Values given in logarithmic scale with reference value 10 W/m\({}^{2}\). to verify the possible applicability of this concept to human head shielding. It does not imitate the final wire alignment that is on the surface of flexible textile material.