esa-sceva/satcom-chunk-collection huggingface dataset:
# Retina-like Imaging and Its Applications: A Brief Review
## 5 Conclusions  
The properties of the retina show good advantages in applications that simultaneously require large FOV, high resolution, and real-time performance. We review the methods and applications that use retina-like mechanisms. On the one hand, retina-like imaging is obtained by hardware or software. Software-based methods are easier to realize than hardware ones, but they have lower efficiencies. On the other hand, the applications including 3D acquisition and reconstruction, target tracking, deep learning, and GI have been introduced and their practical uses have been illustrated in detail. Compared with the traditional 3D acquisition and reconstruction technologies, the technologies that combine the characteristics of retina-like imaging have achieved better results, and corresponding methods are constantly being proposed. In the task of target tracking, the value of retina-like imaging is mainly reflected in the reduction of image noise. Moreover, for the target of rotation and scaling, the tracking of retina-like imaging is more robust. In the application of deep learning, the retina-like mechanism is mainly reflected in the following three aspects. First of all, the retina-like gaze can be treated as an attention mechanism in deep learning to enhance features. Secondly, in solving the problem of multi-scale object detection and recognition, the retina-like rotation and scale invariance also work well. Finally, the accuracy of image recognition of retina-like imaging has been greatly improved. Research on RGI has focused more on the adjustment of the location and size of the region of interest and its different applications in imaging. Most of the current retina-like structures are applied to the design of illumination patterns for GI, and investigating how to realize non-uniform sampling by designing devices may better enhance the performance of RGI. The discussions of challenges and the potential approaches make it easy to understand the direction of the retina-like character, which will help in designing the good performances of imaging.  
Conceptualization, Q.H. and J.C.; methodology, Y.T.; investigation, resources and writing--original draft preparation, M.T., Y.C., D.Z., Y.N., C.B. and H.C.; writing--review and editing, M.T. and J.C.; project administration, Q.H. and Y.T.; funding acquisition, J.C. All authors have read and agreed to the published version of the manuscript.  
The work was supported in part by the funding of foundation enhancement program under Grant 2019-JCJQ-JJ-273 and 2020-JCJQ-JJ-030, in part by the National Natural Science Foundation of China under Grant 61871031, Grant 61875012, and Grant 61905014.  
Not applicable.  
The authors declare no conflict of interest.
# Determination of Geometrical REVs Based on Volumetric Fracture Intensity and Statistical Tests
## 3 Methodology
### Likelihood Ratio Test  
In statistics, a likelihood ratio test is a statistical test used for comparing the goodness-of-fit of two samples. The key of a hypothesis test is the method used to determine the statistics; the statistic \(\lambda\) can be obtained by [PERSON] and [PERSON] (2000):  
\[\lambda=\frac{L_{0}(x_{1},\ldots,x_{n})}{L_{1}(x_{1},\ldots,x_{n})}=\frac{ \sup_{\theta\in\Theta}L_{0}(x_{1},\ldots,x_{n};\theta)}{\sup_{\theta\in\Theta} L_{1}(x_{1},\ldots,x_{n};\theta)} \tag{3}\]  
where \(L_{0}(x_{1},\ldots,x_{n};\theta)\) and \(L_{1}(x_{1},\ldots,x_{n};\theta)\) are the likelihood functions, sup is the supremum function, \(x_{1},\ldots,x_{n}\) represent the observations of the sample, and \(\theta\) represents a notional parameter.  
To quickly obtain the statistic \(\lambda\), a convenient method was proposed by [PERSON] (1988):  
\[-2\ln\lambda=x^{2} \tag{4}\]  
where \(-2\ln\lambda\) is an approximately \(x^{2}\) distribution under the null hypothesis when the sample size \(n\) approximates \(\infty\).  
The critical test statistic \(\lambda_{\alpha}\) is determined based on a threshold level \(\alpha\) that is obeyed by a \(x^{2}\) distribution and Equation (4), and the \(p\) value is determined by  
\[p=p(\lambda\geq\lambda_{\alpha}) \tag{5}\]  
When the \(p\) value is greater than or equal to the significance level \(\alpha\), the two samples are considered statistically similar. Commonly, a 5% significance level is defined as a threshold in the likelihood ratio test to obtain a geometrical REV size for a fractured rock mass.
# Chemical and Sensory Characterization of Vidal Icewines Fermented with Different Yeast Strains
## 3 Results and Discussion
### Chemical Analysis  
#### 3.3.1 Volatile Profiling of Icewines Fermented by Different Yeasts  
Due to the complexity of wine aroma composition and matrix, there were some problems in the separation and detection of wine by one-dimensional gas chromatography, such as insufficient peak capacity, co-outflow, low sensitivity, and so on. Therefore, this method cannot satisfy our needs for the study of wine flavor chemistry. However, the emergence of GC\(\times\)GC-TOFMS provides a useful tool for better separating and identifying these complex components [26]. In this study, the volatile compounds of four different Vidal icewine fermented by four yeasts (ST, K1, EC1118, R2) were analyzed by GC\(\times\)GC-TOFMS. A total of 3784 chromatographic peaks were detected. Figure S1A shows the chromatogram of the volatile components in R2 fermented icewine. It can be seen from Figure S1B that the three compounds, 4-methyl-1-pentanol, 1-butanol, and ethyl valerate, co-flowed in one dimension and were difficult to identify and quantify, but they were well separated in the two-dimensional chromatography. Consequently, it can be proved that GC\(\times\)GC-TOFMS can effectively solve the co-outflow phenomenon and improve the accuracy of qualitative analysis.  
Finally, 485 volatile compounds were identified in four icewine samples, including 123 esters, 26 terpen, 105 alcohols, 115 carbonyl compounds, 23 furans, 21 nitrogen-containing compounds, 19 volatile phenols, 7 sulfides, 35 aromatic compounds, and 11 lactones. A total of 391, 399, 364, and 457 volatile compounds were detected in four icewines, which fermented by K1, EC1118, ST, and R2 yeast, respectively (Table 2). It can be seen that the number of volatile compounds in icewine fermented by R2 was much higher than the other. In addition, there were 347 compounds in common, accounting for 72% of the total volatile compounds. It can also be seen from Table 2 that the icewines fermented by different yeasts differed greatly in yeast fermentation products such as esters, alcohols, carbonyls (aldehydes and ketones), and nitrogen-containing compounds. In previous studies, the aroma compounds were analyzed using GC-MS in Riesling, Vidal, and Cabernet Franc icewines, which was fermented by different yeasts, the differences of aroma compounds mainly in alcohol and ester compounds, and the sum of these two classes of compounds accounted for more than 50% of the total [12,16]. The results of this study were basically consistent with the above research.  
Figure 1: Sensory profiles of Vidal icewines fermented by different yeasts.
# The Application of Mesenchymal Stem Cells on Wound Repair and Regeneration
## 8 Mesenchymal Stem Cells
### Adipose-Derived Stem Cells  
Adipose tissue is another source of multipotent stem cell. Moreover, these cells have identical characteristics in comparison to BM-MSCs. ASCs can differentiate into several lineages (chondrogenic, osteogenic, myogenic and adipogenic) as a feedback to specific stimuli [19; 57]. These cells are heterogeneous, pluripotent and are isolated using liposuction aspirates or excised fat samples. Therefore, they can be obtained with minimal donor morbidity. For that reason, ASCs are easier to obtain in comparison to BM-MSCs due to reduced patient discomfort [7; 23].  
In addition, ASCs can be immediately administered after collection, which means these cells do not need to suffer differentiation in culture or in vitro expansion. As a result, this eliminates the time-consuming steps of in vitro expansion, which makes it quicker to use these cells in comparison with BM-MSCs [7; 23].  
Furthermore, studies have shown that allogeneic T lymphocytes do not proliferate in ASCs culture as a consequence of the cell surface histocompatibility antigen reduction, which inhibits mixed lymphocyte reaction. This fact suggest that ASCs are more suitable for autotransplantation due to their immunocompatibility [12; 19]. Also, ASCs can be applied in tissue regeneration since the application of these cells accelerates the re-epithelialization of cutaneous wounds by promoting human dermal fibroblast proliferation directly (cell contact) or by paracrine secretion (growth factors) [12; 19]. Furthermore, the regeneration potential of these cells is being evaluated, focusing on diverse medical problems like burn wounds and diabetic ulcers [3].
# Helmholtz Resonance Frequency of the Synthetic Jet Actuator
## 1 Introduction
This article includes a detailed description of the coupling between the electromechanical driver model and fluidic effects in the cavity. The author experimentally validated the model for circular and rectangular orifices. A lumped element model of the operation of an SJ actuator driven by a thin piezoelectric disk was also studied by [PERSON] et al. [23]. The authors reported the results of analytical and numerical investigations performed to obtain the information about the frequency response of the studied device. Furthermore, [PERSON] et al. [24] studied the influence of the geometry, such as the cavity height and the orifice length, on the synthetic jet velocity derived from the piezo SJ actuator and, consequently, the SJA Helmholtz resonance frequencies. The application of lumped element models to SJs, also referred to as reduced-order models, was also presented and discussed in [13; 25; 26]. In addition, based on lumped element modeling and the assumption of an incompressible working fluid, [PERSON] and [PERSON] [13] theoretically predicted the optimal diameters of SJ actuator orifices in the cases investigated. A previous study [25] includes a comprehensive review of the development of various lumped element models as practical tools to design and manufacture SJ actuators. The authors of [26] present a reduced-order model that was developed to predict the performance of synthetic jet actuators. The research concerned a classical SJA configuration consisting of a single actuator with rectangular orifice. The CFD results from both 2D and 3D simulations were compared. The authors also compared their numerical results with the experiment, and drew conclusions regarding the validity of the relatively simple analytical method for a variety of conditions, and for a range of frequencies approaching the Helmholtz resonance frequency. An alternative analytical model of the SJ actuator has been presented by [PERSON] [17; 18]. In the proposed model, the driven wall in the cavity is a mechanical system which is pneumatically coupled to the cavity-orifice system operating as a Helmholtz resonator. It should be noted that most of the works cited above concern the use of piezo-driven SJ actuators. The validation of the findings obtained above appears to be justified for loudspeaker SJ actuators, and was one of the objectives of the present work. The SJA Helmholtz resonance frequency is the subject of the present study. Experimental investigations of 108 various geometrical configurations of a synthetic jet actuator were undertaken to determine the impact of the geometry on the Helmholtz resonance frequency. Orifice diameter, orifice length, and cavity volume were changed within a wide range. The existing model used to describe the Helmholtz resonance frequency in the SJ system was verified and calibrated.
## 2 Human Activities and HAR Sensors
### HAR Sensors  
This subsection provides a structured framework to categorise and understand the range of sensors employed in HAR. The type of sensor used in HAR is important, as it influences the kind of data collected and the activities that can be recognised. The initial focus of HAR studies was on activity recognition from images and videos, but later researchers started to explore tracking human behaviour using ambient and wearable sensors [6]. HAR sensors can be grouped into ambient, movement/inertial, and health/physiological sensors. These sensors have attributes of sensitivity, accuracy, range, resolution, and precision. Figure 2 shows the UML diagram of sensors used in the task of HAR.  
Movement sensors are used to sense a person's body motion and return values for \(x,y\), and \(z\) axis. Movement sensors include accelerometers, gyroscopes, and magnetometers [16]. Most smartphones and smartwatches contain an accelerometer and gyroscope and have been used in different HAR research [17]. These movement sensors are the basis for a lot of non-vision HAR tasks and are generally considered non-invasive because they can be found in smartwatches or smartphones, and other wearable devices.  
Ambient sensors gather information about the environment like humidity, sound, temperature, etc. In HAR, ambient sensors are used in smart home environments. Sensors like pressure sensors are used to detect when the participant sits or lies down, and proximity sensors are used to determine the relative position of the occupants in a smart home environment. Vision sensors are also ambient sensors because they gather information about the environment. Location sensors such as GPS are also found in this category.  
Physiological sensors measure health vitals such as heart rate, blood pressure, body temperature, etc. [16]. Photoplethysmography (PPG) sensors are used to detect blood volume through the skin and can be used to estimate blood pressure [18]. They are used in smartwatches to estimate the heart rate of the wearer [19]. Electrocardiogram (ECG) sensors measure the electrical activity of the heart and can also be found on smartwatches. Electroencephalogram (EEG) sensors are used to monitor brain signals, and there are wearable devices with EEG such as Emotiv insight, mindwave, Interaxon Muse and NeuroTracker [20]. Some of these wearable devices with physiological sensors are designed to be worn as headsets, caps, or over-the-ear devices, which makes them non-invasive and easy to use.  
Manufactures of smartwatches have started incorporating additional sensors such as physiological sensors in these devices [21]. Smartphones too now have a wide array of sensors. There are also other wearable devices with some of these sensors like over-the-ear wearable devices or chest straps used to measure health vitals. The availability of these non-invasive wearable devices with the necessary sensors has made the deployment of HAR applications more feasible.  
Figure 2: UML, diagrams of sensors used in HAR.
###### Abstract  
The presence of antibiotic residues in seafood and their effect on public health constitute a matter of concern for consumers worldwide. Antibiotic residues can have adverse effects on both humans and animals, especially residues of banned veterinary drugs. In this study, we applied a validated method to analyze veterinary drug residues in shrimp, including the levels of banned chloramphenicol, malachite green, leucomalachite green, and four nitrofuran metabolites as well as thiamphenicol, florfenicol, and five quinolones, which have no recommended maximum residual levels in shrimp tissues in Taiwan. We collected 53 samples of whiteleg, grass, or giant river shrimp from Taiwanese aquafarms and production areas from July 2016 to December 2017. We found 0.31 ng/g of a chloramphenicol in one grass shrimp, 5.62 ng/g of enrofloxacin in one whiteleg shrimp, 1.52 ng/g of flumequine in one whiteleg shrimp, and 1.01 ng/g of flumequine in one giant river shrimp, indicating that 7.55% of the samples contained veterinary drug residues. We evaluated the health risk by deriving the estimated daily intake (EDI). The quinolone residue EDI was below 1.0% of the acceptable daily intake recommended by the United Nations Food and Agriculture Organization and World Health Organization. The risk was thus discovered to be negligible, indicating no immediate health risk associated with shrimp consumption. The present findings can serve as a reference regarding food safety and in monitoring of the veterinary drug residues present in aquatic organisms. Continual monitoring of residues in shrimp is critical for further assessment of possible effects on human health.  
**Keywords:** veterinary drug; residue; shrimp; mass spectrometry; risk assessment
# Influence of Roll Diameter on Material Deformation and Properties during Wire Flat Rolling
## 2 FE Analysis and Model Validation
### Experimental Procedures  
Experimental tests were conducted to validate the present FE model. A 50 kg ingot with a chemical composition of Fe-19.94 Mn-0.6C-1.03 Al in weight percent was fabricated using a vacuum induction method under inert gas. After homogenization in a box furnace at 1200 \({}^{\circ}\)C for 12 h, the ingot with 125 mm in thickness was directly rolled to a 20 mm-thick plate in the temperature range of hot deformation in steels (from 950 \({}^{\circ}\)C to 1150 \({}^{\circ}\)C) using  
Figure 1: Schematic illustration of wire flat rolling with the roll diameter and related parameters used in this study.  
several rolling machines. Subsequently, it was naturally cooled in air to RT in order to simulate the hot rod rolling process. Tensile specimens (5 mm-diameter and 25 mm-long in gauge) machined from the hot-rolled plate were pulled at a strain rate of 10\({}^{-3}\) s\({}^{-1}\) at RT. Figure 2a presents the true stress-strain curve of the hot-rolled steel. This steel exhibited high strength and excellent elongation owing to the deformation twinning during plastic deformation [6; 7]. For a better evaluation of the strain hardening behavior of this steel, [PERSON]'s law was used to evaluate the strain hardening exponent (\(n\)) as follows:  
\[\sigma=K\varepsilon^{n} \tag{5}\]  
where \(K\) is the strain hardening coefficient. Based on the above equation, the instantaneous \(n\) was calculated with true strain using the following equation:  
\[n(\varepsilon)=\left.\frac{d\ ln\sigma}{d\ ln\varepsilon}\right|_{\hat{ \varepsilon},\ T=const.} \tag{6}\]  
The instantaneous \(n\) increased gradually with the true strain as shown in Figure 2b.  
Several 13 mm-diameter wires were machined from the hot-rolled plate along the rolling direction. In addition, the initial wires were reduced at an \(R_{h}\) of 10%, 20%, 30%, and 40% using a single pass-type rolling simulator with 400 mm-diameter flat rolls at RT. No lubricant was applied to the wire prior to the wire flat rolling process. The rolling speed was set to 5 rpm to ignore the temperature rise or strain rate effects during the forming process.
# Research on Building Target Detection Based on High-Resolution Optical Remote Sensing Imagery
## 5 Conclusions  
In this study, building detection in remote sensing image applications was studied. To make the detection of building targets in remote sensing images more accurate, a novel building detection method was developed by fusing the results of the rectangular approximation-based and saliency-based methods to avoid leakage and false detection using individual features. First, for the geometric structure of the top surface of the building target is mostly right-angle primitives composed of mutually perpendicular line segments, this paper proposed a building detection method based on rectangular-approximation and region growth and obtained the saliency map of the building area using a saliency detection model based on the foreground compactness and local contrast of the manifold ranking algorithm. Then, the boundary priori saliency detection method based on the improved manifold ranking algorithm was adopted to successfully detect building targets with low contrast with the background, and the saliency detection results were integrated. Next, introduce the bounding box proposal to remove the environmental noise to obtain the final saliency map, and set the adaptive threshold to obtain the mask map. Finally, the detection results based on rectangular approximation and saliency map were combined and the ocean area in the image was segmented to remove the interference of ships and trestles to achieve the detection of building targets.  
In summary, the building target detection method using the fusion of rectangular approximation and saliency detection can avoid the problems of false detection and missing the detection of building targets caused by the fewer gray levels and low resolution of remote sensing images, low contrast between targets and background, shadow occlusion, uneven illumination, and improve the accuracy of building target detection compared with the building target detection method using a single image feature.  
Conceptualization, methodology, visualization, and writing--original draft preparation, Y.M.; data curation, formal analysis, supervision, project administration, funding acquisition, and writing--review and editing, H.C.; investigation, software, resources, and validation, S.Y. All authors have read and agreed to the published version of the manuscript.  
This research was funded by National Natural Science Foundation of China, grant number 61771170.  
Not applicable.  
The authors declare no conflict of interest.
# What Is an Open IoT Platform?
## 3 Results
### Q2: Which Are the Openness Types of IoT Platforms?

Table 3: The open IoT platforms identified in “proposed” category and their connection to different openness types. Society), W3C (World Wide Web Consortium), IETF (Internet Engineering Task Force) and IAB (Internet Architecture Board). The open standards require five key principles, including cooperation, collective empowerment, availability and voluntary adoption to serve products and services targeted for different market requirements [44]. Open standards are primarily important to provide the support for heterogeneous devices to enable better interoperability [12]. **Open APIs**: are publicly available application programming interfaces that provide developers with programmatic access to a proprietary or open software application or to a web service [45]. Open APIs are usually used by third-party developers. **Open Data**: should be freely available to everyone to use and republish as they wish, without restrictions from copyright, patents or other mechanisms of control [46]. **Open Layer**: is a technical description rather than a formal term. Based on the context of the related papers, the open layer is considered to be a software layer of the platform that is open for third-party software integration. Reflecting on our study, we observe that open-source is the most widely accepted openness type as it is more convenient for third-party developers to have a full access to the source code. Open standards, such as that on which FIWARE is based, has some overlap with open APIs; however, they are usually used under different contexts. For example, FIWARE has a FIWARE-NGSI version 2 API in its specification, which is intended to manage the lifecycle of the context information. Moreover, the FIWARE open APIs are slightly different from the ones provided by ThingSpeak; for example, FIWARE APIs are part of the open standards. Another interesting observation is gleaned by looking at Tables 2 and 3, which reveal that 1 out of 21 proposed open IoT platforms are not widely used ones, besides the OpenIoT platform. This is mainly because the OpenIoT was a funded research project which was mainly used by the involved partners.