esa-sceva/satcom-chunk-collection huggingface dataset:
## The Invention of an Optical Antenna--A Personal Reminiscence
This was easy enough: Our standard setup consisted of a pulsed IR laser and a confocal microscope which imaged the substrate with the dipoles and rods in reflection. PhD student [PERSON] who ran the experiment simply had to place an additional notch filter into the reflected beam. The incident IR radiation was strongly suppressed now but--lo and behold--there were spots of IR and visible light at the position of some antennas! Further experiments revealed various blue-shifted components which increased with second, third and even fourth power of the incident intensity--a clear indication of nonlinearity. Moreover, this radiation was visible only from properly oriented antennas with gap, having a certain length, and not on equal-length rods [5]. This confirmed the expectation of a nanometer-size, intense light spot at the gap, the center of the antenna. The view of the light spot was completed by a simultaneous experiment of our colleagues [PERSON] and [PERSON]. They scanned an optical dipole over a film that contained single, fluorescing Q-dots. When the center of the antenna came close to the Q-dot a large reduction of lifetime and an increase of intensity were observed [6]. Such a behavior is typical for fluorescence in a strong field. The end of these experiments marked also the end of our team at Basel University. Four of us were contracted by other universities or industry; I had reached the age limit and retired, heavy-heartedly in view of all the questions and opportunities that became apparent in the course of the antenna experiments. The phenomena as well as their selectivity regarding direction, polarization, and resonance frequency bore--and, to my opinion, still bear--potential. Their derivation from electrical engineering has caused a new view of some optical phenomena. They link into various fields like quantum optics and electronics, communication, manipulation and, last not least, microscopy. Electrons in a metal feel their finite mass at optical frequencies. The plasmon dispersion curve--indistinguishable from the photon curve at low frequencies--bends towards the horizontal. It saturates at the plasma frequency \(\upvarphi\). In the transition region the residual conductance may still allow for some electro-technical applications, for instance rectification or multiplexing of antenna currents. Beyond this range (\(\upomega>\upvarphi\)), however, all metals become insulators. That pulls the carpet from under conventional electric-magnetic circuitry which depends on long paths of conduction. The optical/uv regime is the end of the long-pursued engineering trend towards higher frequencies, and the optical antenna may be one of the last devices designed to the rules of conventional electromagnetic wisdom. Thanks go to my collaborators--too many over the years to be cited individually (Consult my publication list [7] for names)--and to the colleagues and friends of the outstanding \"NFO\" community. Without them, this work would have been just another episode in the ever-lasting struggle for progress in science. The author declares no conflicts of interest
Sensors_**2015**, _15_, 14458-14486; doi:10.3390/s150614458  
\begin{tabular}{c}  \\ _Sensors_ \\
**ISSN 1424-8220** \\ www.mdpi.com/journal/sensors \\ _Article_ \\ \end{tabular}  
DeADS: Depth and Energy Aware Dominating Set Based Algorithm for Cooperative Routing along with Sink Mobility in Underwater WSNs  
**[PERSON] 1, [PERSON] 1,*, [PERSON] 1, [PERSON] 2, [PERSON] 3,**  
**[PERSON] 4 and [PERSON] 1**  
1 COMSATS Institute of Information Technology, Park Road, Islamabad 44000, Pakistan;  
E-Mails: [EMAIL_ADDRESS] (A.U.); [PERSON]S] (A.A.);  
[EMAIL_ADDRESS] (A.H.)  
2 Internetworking Program, FE, Dalhousie University, Halifax, NS B3J 4R2, Canada;  
E-Mail: [EMAIL_ADDRESS]  
3 University of Alberta, AB T6G 2J8, Canada; E-Mail: [EMAIL_ADDRESS]  
4 College of Applied Medical Sciences, Department of Biomedical Technology, King Saud University,  
Riyadh 11633, Saudi Arabia; E-Mail: [EMAIL_ADDRESS]  
* Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS];  
Tel.: +92-3005792728.  
Academic Editor: [PERSON]  
_Received: 26 March 2015 / Accepted: 10 June 2015 / Published: 18 June 2015_  
**Abstract:** Performance enhancement of Underwater Wireless Sensor Networks (UWSNs) in terms of throughput maximization, energy conservation and Bit Error Rate (BER) minimization is a potential research area. However, limited available bandwidth, high propagation delay, highly dynamic network topology, and high error probability leads to performance degradation in these networks. In this regard, many cooperative communication protocols have been developed that either investigate the physical layer or the Medium Access Control (MAC) layer, however, the network layer is still unexplored. More specifically, cooperative routing has not yet been jointly considered with sink mobility. Therefore, this paper aims to enhance the network reliability and efficiency via dominating set based cooperative routing and sink mobility. The proposed work is validated via simulations which show relatively improved performance of our proposed work in terms the selected performance metrics.  
**Keywords:** depth threshold; dominating set; cooperative routing; sink mobility; underwater wireless sensor networks
# Phase Balancing and Reactive Power Support Services for Microgrids
###### Abstract  
Alternating current (AC) microgrids are expected to operate as active components within smart distribution grids in the near future. The high penetration of intermittent renewable energy sources and the rapid electrification of the thermal and transportation sectors pose serious challenges that must be addressed by modern distribution system operators. Hence, new solutions should be developed to overcome these issues. Microgrids can be considered as a great candidate for the provision of ancillary services since they are more flexible to coordinate their distributed generation sources and their loads. This paper proposes a method for compensating microgrid power factor and loads asymmetries by utilizing advanced functionalities enabled by grid tied inverters of photovoltaics and energy storage systems. Further, a central controller has been developed for adaptively regulating the provision of both reactive power and phase balancing services according to the measured loading conditions at the microgrid's point of common coupling. An experimental validation with a laboratory scale inverter and a real time hardware in the loop investigation demonstrates that the provision of such ancillary services by the microgrid can significantly improve the operation of distribution grids in terms of power quality, energy losses and utilization of available capacity.  
AC microgrid; ancillary services; asymmetrical loading conditions; grid-tied inverter; phase balancing; power factor compensation; reactive power support +
Footnote †: journal: Applied Sciences  
Article
# Modeling Movement Stability of Machine-Tractor Units Based on Modular Type Tractor
In the latter, the third bridge is not a detachable/attachable module, but part of its construction, being rigidly connected to the main tractor frame in the horizontal plane [16]. Machine-tractor units, in which one of the axes of the used trailed machine is considered a technological module, are also unsuitable for developing the required mathematical model [17; 18; 19]. Moreover, the above-mentioned publications did not use any mathematical description of the units operating in the horizontal plane. This does not allow us to evaluate the controllability or stability of their plane-parallel movement. Article [20] examines the technological module's influence on the modular tractor traction performance. In particular, the authors' calculations established that using TM makes it possible to increase the traction force of the entire vehicle by 1.43 times. As for the forces acting on it, their dynamics are not considered in the horizontal or longitudinal-vertical planes. The results of experimental studies of a modular tractor in a unit with a disc narrow are presented in articles [21; 22]. The technological module is rigidly connected to the energy module in the horizontal plane. However, the controllability of the unit's movements and/or stability are not considered. The theory of unit operation based on a modular tractor is presented in [23]. It addresses the issue of damping the vertical hinge joining the EM and TM in the horizontal plane. At the same time, neither the free nor the locked state of this hinge is considered in the study. Furthermore, the mathematical model of the unit presented in this work does not consider the frontal or lateral arrangement of agricultural machines. And such MTU diagrams based on a modular tractor, as shown in practice, are promising [24]. Because of the above, the objective of this article is to model the motion stability of machine tractor units based on a modular tractor. To achieve this objective, the following tasks were set:  
1. to develop a mathematical model of the horizontal movement of the unit based on a modular tractor, reflecting different states of the vertical hinge TM (free, blocked, controlled) with different locations of the agricultural machines (front, side);
2. verification of the adequacy of the developed mathematical model;
3. to study the influence of the TM vertical hinge state on the stability of the unit's movement based on a modular tractor. The practical implementation of the article's objectives allows us to create an adequate mathematical apparatus that will enable us to solve the following scientific problems: (i) to study the stability and controllability of the wide-operating units based on a modular tractor; (ii) to justify the number of machines used with a tractor (from 1 to 3); (iii) to study the controllability and stability of the unit's movement with simultaneous turning of the EM's front wheels and the TM frame; (iv) to evaluate the trajectory indicators of the units movement based on a modular tractor with simultaneous turning of its front wheels and the TM ones.
# Direct Multistep Wind Speed Forecasting Using LSTM Neural Network Combining EEMD and Fuzzy Entropy
## 3 The EEMD-FuzzyEn-LSTMNN Model  
In this section, the EEMD-FuzzyEn-LSTMNN model is established for wind speed forecasting based on the concept of \"decomposition and ensemble\". The flowchart of the proposed model is shown in Figure 3. The main structure of the EEMD-FuzzyEn-LSTMNN model includes the following four steps:  
1. Use EEMD to decompose the original wind speed series into a number of IFM components and a residual component. These components are respectively denoted by IMF\({}_{1}\), IMF\({}_{2}\),..., IMF\({}_{n}\) and R\({}_{n}\).
2. Calculate the FuzzyEn of each component and classify all components according to the calculated FuzzyEn values. The components with similar FuzzyEn values are classified into  
Figure 2: The structure of forecasting model for wind speed series at the time-step \(i\): (**a**) the RNN forecasting model; (**b**) the LSTMNN forecasting model.  
one group, and the components in one group are superimposed to obtain a new subsequence. All subsequences are respectively denoted by \(S_{1}\), \(S_{2}\),..., \(S_{N}\).
* Use the LSTMNN model to forecast each subsequence separately.
* Aggregate the forecasting result of each subsequence to obtain the ultimate forecasting series of wind speed.
# Madeira Wine Volatile Profile. A Platform to Establish Madeira Wine Aroma Descriptors
## 2 Results and Discussion  
HS-SPME/GC-qMS methodology was used to establish the Madeira wine volatile profiling, as a sensitive technique to explain the unique aroma descriptors of Madeira wines. Considering the five grape varieties under study, a set of 82 VOCs (Table 1), namely 21 esters, 13 higher alcohols, ten terpenic compounds, nine fatty acids, seven norisoprenoids, seven furanic compounds, six lactones, four acetals, four volatile phenols and one sulphur compound (Tables S1 and S2), have been identified by matching the obtained mass spectra with the reference compounds spectra in NIST Mass Spectral Search Program with a resemblance percentage above 80% and by comparison of the KIs calculated (\(\mathrm{KL_{calc}}\)) with the values reported in the literature (\(\mathrm{KI_{lit}}\)) for polyethylene glycol (or equivalent) column. A range between 0 and 35 (\(\mathrm{|KI_{calc}-KI_{lit}|}\)) was obtained for \(\mathrm{KI_{cal}}\) compared to the \(\mathrm{KI_{lit}}\) reported in the literature for GC with polyethylene glycol GC column or equivalent. This difference in KI is acceptable (\(<\)5%) taking into account that the literature data is obtained from a large range of GC stationary phases (several commercial GC columns are composed of polyethylene glycol or equivalent stationary phases). The relative concentration of each VOC and their relative standard deviation (%RSD) in dry/medium dry and sweet/medium sweet are available as Supplementary Material on Tables S1 and S2, respectively. Sixty-nine VOCs were common in all wine samples analyzed, namely seven terpenic compounds, six norisoprenoids, 13 alcohols, 21 esters, 9 acids, four acetals, seven furanic compounds and two volatile phenols (Tables S1 and S2). The number of identified VOCs ranged from 77 to 79 for Malvasia wines, from 78 to 79 for Bual wines, from 76 to 80 for Sercial wines, and from 77 to 80 for Verdelho wines, for young and old wines, respectively. For Tinta Negra variety, different types of wines were considered. It was observed that the number of VOCs ranged from 77 to 79 for dry, from 80 to 82 for medium dry, from 76 to 80 for sweet, and from 79 to 81 for medium sweet, for young and old wines, respectively.
## 1 Introduction
### Leak Detection Methods  
Many methods for detecting leaks in water distribution infrastructure have emerged. Leak detection methods can be categorized as destructive (DT) and non-destructive techniques (NDT). Destructive techniques alter the chemical composition or the dimensional geometry of the material under testing. The external installation of hardware devices on water pipelines, which requires excavation of the soil above the pipes, is an example of DTs. Due to the complexity of DTs, NDTs are widely preferred because they provide an opportunity to evaluate the properties and condition of the materials, i.e., water pipes, without changing the structure of the water distribution infrastructure, without excavating the soil above the water pipes, or without disrupting the serviceability of the system. Several NDTs have proven their ability to detect leaks in water infrastructure. Table 1 summarizes some of the NDTs often used for water leak detection. Most methods are limited in their ability to apply the technologies consistently in wide-ranging environmental circumstances. In addition, there are technologies that are complicated for field applications and some of them are also unproven. Due to the limitations of the currently used leak detection methods, robust methods, which can be easily implemented, are efficient, and are reliable, are being investigated. The following three NDTs were chosen for further study: Ground Penetrating Radar (GPR), a hand-held spectrometer, and an infrared (IR) camera. This study also investigated the versatility of these technologies in wide-ranging environmental conditions. Transient Test-Based Techniques (TTBTs) identify leaks and other possible faults (e.g., partial blockages and pipe wall deteriorations) straightforwardly on the basis of
## 2 Materials and Methods
### Testing of Membership Functions  
A member's level of accuracy inside a specified fuzzy set is defined by a membership function. They are curves that show how each point in the input space is translated to a membership degree ranging from 0 to 1 [36]. One-dimensional membership functions like triangle, trapezoid, gaussian, and sigmoidal can be utilized, depending on how the input variables behave.  
The complexity and requirements of the fuzzy logic system determine the number of membership functions. More complex systems usually require more membership functions. The number of membership functions to be defined for each input variable must be determined. This is usually determined by expert knowledge or experience in the problem domain.  
The representation and initial design of a fuzzy system are made simpler by linear membership functions, which also have a linear form for triangular and trapezoidal membership functions. Although more difficult to build, uniform membership functions like Gaussian and sigmoidal are more effective for automatic control [37]. The membership functions were calculated with Equations (11)-(13) below:  
TriMF:  
\[\mu\left(x;\alpha,\beta,\gamma\right)=\left\{\text{(if $\alpha\leq x\leq\beta$, $(x-\alpha)/(\beta-\alpha)$; if $\beta\leq x\leq\gamma$, $(\gamma-x)/(\gamma-\beta)$; if $\gamma\leq x$ or $x\leq\alpha$, 0)$}\right\} \tag{11}\]  
TrapMF:  
\[\mu\left(x;\alpha,\beta,\gamma,\lambda\right)=\left\{\text{(if $\alpha\leq x\leq\beta$, $(x-\alpha)/(\beta-\alpha)$; if $\beta\leq x\leq\gamma$, $1$; if $\gamma\leq x\leq\lambda$, $(x-\lambda)/(\gamma-\lambda)$; if $x>\lambda$ or $x<\alpha$, 0)$}\right\} \tag{12}\]  
GaussMF:  
\[\mu\left(x;c,s,m\right)=\exp^{*}(-1/2\times\mid(x-c)/s\mid^{\top}m), \tag{13}\]
## 2 Experimental Section
### Materials Characterization  
1H NMR spectra were recorded on a Varian INOVA 500 MHz spectrometer using trimethylsilyl (TMS) as an internal standard with the solvent values (\(\delta\) = 7.26 ppm for CDCl3-d1). Fourier transform infrared (FTIR) spectra were recorded on a FTIR 650 Spectrometer (BRUKER AXS GMBH) through KBr disks to analyze the chemical structure over a range of 400-4000 cm\({}^{-1}\) at a resolution of 4 cm\({}^{-1}\). Matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF MS) spectra were measured with a Bruker Autoflex tof/tofill mass spectrometer. X-ray diffraction (XRD) was performed on a D8 Advanced X-ray diffractometer (BRUKER AXS GMBH) with Cu K\(\alpha\) radiation (\(\lambda\) = 0.154 nm). The glass transition temperature (Tg) of the poly(S-MVT)s was determined using DSC (Q20, TA Instruments) with a heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\) from ambient temperature to 800 \({}^{\circ}\)C in N\({}_{2}\) atmosphere. Differential scanning calorimetry (DSC) characterization was carried out using a TA Q20 instrument. X-ray photoelectron spectrum (XPS) measurement was performed on a PHI 1600 surface analysis system at a power of 450 W equipped with an Mg K\(\alpha\) anode. Morphology characterization of the materials was conducted by field emission scanning electron microscopy (FESEM) (Hitachi S-4800) and transmission electron microscopy (TEM) (JEOL JEM-2100F). The thermal stabilities of the copolymers were tested at a heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\) under N\({}_{2}\) atmosphere, using a thermogravimetric analysis (TGA) system (NETZSCH STA 449C).
## 3 Results and Discussions
### The pH, TTA, TSS, Crude Protein, IVPD, Vitamin C, and Antintutitional Factors
\begin{table}
\begin{tabular}{c c c c c} \hline
**Samples** & **Control** & **12 h** & **24 h** & **48 h** \\ \hline pH & 6.50 \({}^{\text{d}}\)\(\pm\) 0.5 & 6.08 \({}^{\text{c}}\)\(\pm\) 0.4 & 4.90 \({}^{\text{b}}\)\(\pm\) 0.3 & 4.20 \({}^{\text{a}}\)\(\pm\) 0.5 \\ TTA (\% lactic acid) & 0.12 \({}^{\text{a}}\)\(\pm\) 0.1 & 0.22 \({}^{\text{b}}\)\(\pm\) 0.2 & 0.58 \({}^{\text{c}}\)\(\pm\) 0.3 & 0.81 \({}^{\text{d}}\)\(\pm\) 0.4 \\ TSS (\({}^{\text{c}}\)Brix) & 5.82 \({}^{\text{d}}\)\(\pm\) 0.5 & 4.91 \({}^{\text{c}}\)\(\pm\) 0.3 & 3.20 \({}^{\text{b}}\)\(\pm\) 0.3 & 2.12 \({}^{\text{a}}\)\(\pm\) 0.2 \\ \hline Crude Protein (\%) & 1.82 \({}^{\text{a}}\)\(\pm\) 0.3 & 2.30 \({}^{\text{b}}\)\(\pm\) 0.4 & 2.64 \({}^{\text{c}}\)\(\pm\) 0.6 & 3.01 \({}^{\text{d}}\)\(\pm\) 0.7 \\ IVPD (\%) & 47.32 \({}^{\text{a}}\)\(\pm\) 0.2 & 57.71 \({}^{\text{b}}\)\(\pm\) 0.4 & 69.20 \({}^{\text{c}}\)\(\pm\) 0.3 & 78.51 \({}^{\text{d}}\)\(\pm\) 0.5 \\ Vitamin C (mg/100 g) & 20.52 \({}^{\text{a}}\)\(\pm\) 0.5 & 25.81 \({}^{\text{b}}\)\(\pm\) 0.7 & 29.72 \({}^{\text{c}}\)\(\pm\) 0.5 & 35.23 \({}^{\text{d}}\)\(\pm\) 0.3 \\ \hline Phytale (mg/100 g) & 205.43 \({}^{\text{d}}\)\(\pm\) 2.5 & 162.31 \({}^{\text{c}}\)\(\pm\) 1.8 & 120.52 \({}^{\text{b}}\)\(\pm\) 1.2 & 72.72 \({}^{\text{a}}\)\(\pm\) 0.9 \\ Hydrogen Cyanide (mg/100 g) & 25.14 \({}^{\text{d}}\)\(\pm\) 0.7 & 20.23 \({}^{\text{c}}\)\(\pm\) 0.9 & 11.62 \({}^{\text{b}}\)\(\pm\) 0.6 & 5.34 \({}^{\text{a}}\)\(\pm\) 0.4 \\ Trypsin Inhibitor Activity (TIU/mg) & 19.57\({}^{\text{d}}\)\(\pm\) 0.8 & 15.22 \({}^{\text{c}}\)\(\pm\) 0.7 & 12.13 \({}^{\text{b}}\)\(\pm\) 0.6 & 5.45 \({}^{\text{a}}\)\(\pm\) 0.4 \\ \hline \end{tabular} Mean values with different superscripts in a column are significantly (\(p\leq 0.05\)) different from each other.  
\end{table} 
Table 1: Effects of natural fermentation time on cassava root flour pH, TTA, TSS, crude protein, IVPD, Vitamin C, and antinutritional factors. enzymatic action of microbial phytases, which hydrolyze phytate into lower inositol phosphates and free phosphorus [31]. Hydrogen cyanide, a toxic compound in raw cassava, showed a significant decline from 25.14 mg/100 g (control) to 5.34 mg/100 g (48 h). This detoxification occurs due to microbial imamarase activity, which facilitates the enzymatic hydrolysis and volatilization of cyanogenic glycosides [32]. Trypsin inhibitor activity (TIA), which interferes with protein digestion, decreased from 19.57 TIU/mg in the control to 5.45 TIU/mg after 48 h. The reduction is likely due to microbial proteases degrading trypsin inhibitors, thus improving protein bioavailability and digestibility [33].
# Frequency Selective Surfaces: A Review
## 4 Types of FSSs
### FSSs Based on Applications  
FSSs have been used in various applications ranging in different frequency bands from RF, micro-, millimeter wave, and terahertz regions [97; 114; 115]. Some of the researches are well demonstrated in radio frequency identifications [9; 116], wireless communications [117; 118], shielding purposes/EMI/EMC problems [58; 81; 82; 119], polarization transformation [120], stealth radomes [75; 98; 103; 121], EMI protection from portable electronics/wireless charging pad [122; 123], directional multi-band antenna [124], polarization detection [125], and sensing [28; 126]. Although a diverse categorization of FSSs can be made based on their applications, here we investigate six types of FSSs in this survey including microwave absorbers, active FSSs, wearable FSS, meta-skin FSS, optical FSS, and textile FSSs.  
Figure 13: General equivalent circuit model of a 3D FSS with multiple resonators or modes [112].
## 3 Experimental Results
### Comparison of Location Results in Different Scenarios
#### 3.1.1 Open Scene  
The positioning result after setting the azimuth angle and mask angle of the open scene in Section 2.2 is shown in the figures below.  
As can be seen from Figure 9, after the LEO constellation was introduced in the open scene, the LEO/INS position accuracy increased by an order of magnitude to sub-meter in the east direction compared with GNSS/INS position accuracy. Affected by the poor accuracy of 5G/INS position, the overall federated filtering accuracy is in meter level, but it is higher than the accuracy of single 5G/INS position, and the positioning error is more stable than 5G/INS, the positioning convergence speed is faster, and the positioning continuity is more guaranteed. According to the DOP value analysis of GNSS and LEO constellations in Figure 10, it can be seen that the geometric distribution of the LEO constellation is significantly improved compared with that of the GNSS constellation. The results of velocity error and attitude error of the Open scene can be seen from Figures A1 and A2 in Appendix A. The error values after using the federated filtering algorithm in this article both are relatively stable.