esa-sceva/satcom-chunk-collection huggingface dataset:
## 2 Background of Research and Construction of New Dataset
### Building a Dataset for the Topography of South Korea  
This paper aims to classify Korean topography according to the characteristics of Korean topography and to derive a method for automatic classification by applying ML techniques using topographic information data processed in various forms. Since there is no publicly available data set for topography type classification, we construct a new dataset using 30 m resolution DSM for the entire area of South Korea. In this paper, we categorize the topography of Korea into five types: _Near Urban_, _Hilly Suburban_, _Mountainous_, _Sea with the Ground_, and _Sea_. Compared to the topography of the United States, the Korean Peninsula is small in area and has a low degree of diversity in topography. For example, the topography of the United States has terrain such as deserts, and the steepness of mountains varies greatly, but this is not the case in Korea. So, it is efficient and sufficient to classify Korean topography into five categories. Table 2 provides a brief description of the five topography classes. _Near Urban_ refers to urban topography and is defined as an area with many buildings. _Hilly Suburban_ is a suburban terrain and includes mainly small hills or low buildings with trees, forests, and rice fields. _Mountainous_ is a mountainous area. _Sea with the Ground_ refers to an area with both land and sea as the coast. _Sea_ is a terrain of only water with zero altitudes. Figure 2 shows an example of five types of topography using DSM data with a resolution of 30 m.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Setting** & **Location** & **Specific Environment** \\ \hline Mountainous [15] & Telluride, CO & Very ’Mountainous’ terrain \\ \hline Hilly [15] & Palmdale, CA & Dry, hilly terrain with natural cover \\ \hline Hilly Suburban [16] & Palmdale, CA & Open, flat desert \& agricultural terrain \\ \hline Fresh Water [14] & Cleveland, OH & Open fresh water \\ \hline Suburban [16] & Cleveland, OH & Suburban, some over-water, flat terrain \\ \hline \hline \end{tabular}
\end{table}
Table 1: _Cont._  
Figure 2: DSM example of Korean topographic classes.  
In this paper, the terrain feature data used for applying ML is the altitude information at the longitude and latitude of each grid point in the analysis area. There are two types of altitude information. First, there is a DEM. The DEM is a topographic model that expresses the bare earth part of topographic information, excluding buildings, trees, and artificial structures. Second, DSM is a model representing all information in the real world, such as trees, buildings, and artificial structures [19]. Since buildings and artificial structures are essential in classifying urban and suburban environments, we use DSM in this paper. We construct the Korean topography dataset by selecting 200 data samples for each topography class, checking the satellite images from all over South Korea, and labeling them. Each image covers a three km-by- three km area.
## 6 Results and Discussion
### Comparison among Our Experiments
The green represents the experiment of _similarity_gpu_ngpu_bs_. approximately 10% and 9%, respectively, compared to their counterparts without the round-based mechanism. The extent of improvement varies as the number of jobs increases. **Improvement of integrating job packing. ** Figure 6 shows an improvement along all considered metrics when using job packing (light blue and light green dotted lines). The most significant gains come when applying job packing along with adjusting the batch size (_similarity_gpu_ngpu_bs_cd_jp_). Figure 6a-d show that the experiment of _similarity_gpu_ngpu_bs_cd_jp_ outperforms others. As the number of jobs increases, its performance significantly surpasses the approaches without job packing. At the high load of 200 jobs, the _similarity_gpu_ngpu_bs_cd_jp_ experiment decreases the makespan by approximately 16% compared to its counterpart with a round-based mechanism but without job packing. It decreases the average job completion time by approximately 20% and the average waiting time by approximately 35%.
## 1 Introduction  
This paper addresses a fundamental issue in algorithm design, of both theoretical and practical interest: how to cope with unavoidable imprecision in data. We focus on a class of problems associated with location uncertainty arising from the motion of independent entities when location queries to reduce uncertainty are expensive. For concreteness, imagine a collection of robots following unpredictable trajectories with bounded speed. If an individual robot is not monitored continuously there is uncertainty, growing with the duration of unmonitored activity, concerning its precise location. This portends some risk of collision with neighboring robots, necessitating some perhaps costly collision avoidance protocol. Nevertheless, robots that are known to be well-separated at some point in time will remain free of collision in the near future. How then should a limited query budget be allocated over time to minimize the risk of collisions or, more realistically, help focus collision avoidance measures on robot pairs at serious risk of collision?We adopt a general framework for addressing such problems, essentially the same as the one studied by [PERSON] et al. [1] and by [PERSON] et al. [2]. In this model, an entity may be queried at any time in order to reveal its true location but between queries, location uncertainty, represented by a region surrounding the last known location, grows. Our goal is to understand with what frequency such queries need to be performed, and which entities should be queried, in order to maintain a particular measure of the congestion potential of the entities, formulated in terms of the overlap of their uncertainty regions. We describe query schemes that ensure a specified bound on two measures of congestion potential at a specified target time. Our schemes are shown to be competitive, in terms of query granularity, with all other schemes that ensure the same bound.  
While the problem of guaranteeing low congestion potential at a fixed target time is of interest in its own right, it also serves to set the stage for the more ambitious task of guaranteeing low congestion potential continuously (i.e., at all times). This task is taken up in a companion paper [3] where we present query schemes to maintain several measures of congestion potential that, over every modest-sized time interval, are competitive in terms of the frequency of their queries, with any scheme that maintains the same measure over that interval alone.
# Enhancing Healthcare Security: A Unified RBAC and ABAC Risk-Aware Access Control Approach
## 6 Discussion and Evaluation
This suggests it focuses on user-friendly interfaces and tools, making it easier for users to interact with the access control system. The proposed model also emphasizes scalability, a feature shared with only [PERSON] et al. [7]. This indicates it is designed to handle large-scale deployments and manage data from a large number of users, making it suitable for various applications. Finally, this paper provides a novel approach that combines RBAC, ABAC, and a risk engine to enhance security in healthcare systems, which was not explored or developed previously. The proposed model stands out by incorporating features that address key challenges in traditional access control models in the healthcare domain, including layered security, dynamic risk assessment, simplified administration, standardization, usability, and scalability. This makes it a more comprehensive and robust access control solution compared to the other models discussed in the literature. Table 11 summarizes the contribution of the proposed model against the criteria discussed earlier and compares it against studies from the literature. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Criteria** & \begin{tabular}{c} **[PERSON]** \\ **et al.**[7] \\ \end{tabular} & \begin{tabular}{c} **[PERSON]** \\ **et al.**[28] \\ \end{tabular} & \begin{tabular}{c} **[PERSON]** \\ **et al.**[6] \\ \end{tabular} & \begin{tabular}{c} **[PERSON]** \\ **et al.**[6] \\ \end{tabular} & \begin{tabular}{c} **[PERSON]** \\ **et al.**[12] \\ \end{tabular} & \
\begin{tabular}{c} **[PERSON]** \\ **et al.**[39] \\ \end{tabular} &
\begin{tabular}{c} **Proposed** \\ **Model** \\ \end{tabular} \\ \hline Fine-grained access control & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ \\ \hline Layered security & ✓ & X & X & X & X & ✓ \\ \hline Contextual awareness & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ \\ \hline Dynamic risk assessment & X & X & X & ✓ & X & ✓ & ✓ \\ \hline Simplified administration & X & X & X & X & X & X & ✓ \\ \hline Standardization & X & ✓ & ✓ & X & ✓ & ✓ & ✓ \\ \hline Usability & X & X & X & X & X & X & ✓ \\ \hline Scalability & ✓ & X & X & X & X & X & ✓ \\ \hline \hline Merge of RBAC, ABAC and RiBAC & X & X & X & X & X & X & ✓ \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Comparison of criteria across different models.
# Research on Nanometer Precision Measurement Method of High Order Even Aspheres
## 4 Conclusions  
The accuracy of deterministic material removal processes, such as MRF and IBF, is limited by the accuracy of the measurements. The key to realizing the nano-precision manufacturing of optical aspheres is the improvement of measurement accuracy. In this paper, a nano-precision measurement method is proposed for even aspheres of high order. The method uses a combination of non-contact profiler and interferometry to achieve a measurement articulation during the surface shape accuracy of optical aspheres varying from low to high. The correction of mapping distortion ensures correct correspondence between the measurement results and the test surface shape in transverse coordinates, improving the accuracy of material removal. The null test of the optical asphere is accomplished by using a CGH as a null optic. Finally, the wavefront aberrations introduced by the CGH and TF are separated by absolute testing and the absolute surface shape of the optical asphere is obtained. The method proposed in this paper guided deterministic processing to converge the RMS of the surface shape error of the optical asphere from 76.69 to 4.96 nm, successfully realizing the nano-precision manufacturing of optical aspheres. A single measurement method can no longer be sufficient for monitoring the surface shape of optical elements during the entire process of manufacturing. The combination of contact and non-contact measurement, the combination of non-contact and null test, etc. has become more common in the measurement of optical components. The proposed method is also an example of the combination of different methods, along with the application of methods such as absolute testing and mapping distortion correction, which greatly improves measurement accuracy. This method is very effective in guiding the high-precision manufacturing of even optical aspheres of high order, and is expected to realize a breakthrough in the existing optical processing accuracy.  
Conceptualization, S.C. and H.X.; methodology, S.C.; software, H.X. and S.C.; validation, H.X., S.C. and J.L.; formal analysis, H.X. and S.C.; investigation, H.X., S.C. and J.L.; resources, H.X.; data curation, H.X.; writing--original draft preparation, H.X.; writing--review and editing, S.C.; visualization, H.X.; supervision, S.C. and J.L.; project administration, S.C. and J.L.; funding acquisition, S.C. and J.L. All authors have read and agreed to the published version of the manuscript.  
The National Natural Science Foundation of China (No. 52375473 and No. 51991372).  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors upon request.  
The authors declare no conflicts of interest.  
Figure 11: The absolute surface shape of the optical asphere obtained by the absolute testing method proposed in Section 2.3.
# Text Line Extraction in Historical Documents Using Mask R-CNN
###### Abstract  
Text line extraction is an essential preprocessing step in many handwritten document image analysis tasks. It includes detecting text lines in a document image and segmenting the regions of each detected line. Deep learning-based methods are frequently used for text line detection. However, only a limited number of methods tackle the problems of detection and segmentation together. This paper proposes a holistic method that applies Mask R-CNN for text line extraction. A Mask R-CNN model is trained to extract text lines fractions from document patches, which are further merged to form the text lines of an entire page. The presented method was evaluated on the two well-known datasets of historical documents, DIVA-HisDB and ICDAR 2015-HITR, and achieved state-of-the-art results. In addition, we introduce a new challenging dataset of Arabic historical manuscripts, VML-AHTE, where numerous diacritics are present. We show that the presented Mask R-CNN-based method can successfully segment text lines, even in such a challenging scenario.  
text line extraction; deep learning; handwritten documents image analysis; historical documents; Mask R-CNN +
Footnote †: journal:  
0000-0001-6000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-00000-  
This paper has two main contributions.  
1. We present a text line extraction method that uses Mask R-CNN for text line extraction in historical documents. The Mask R-CNN model is trained to extract text lines from patches, which are further merged to form text lines of an entire page (see Figure 1);
2. We introduce a new challenging dataset of historical documents in Arabic, VML-AHTE (Visual Media Lab--Arabic Handwritten Text Line Extraction). The documents in VML-AHTE exhibit a challenging scenario, where multiple diacritics are present.  
The proposed Mask R-CNN method was evaluated on three different datasets of historical document, Diva-HisDB [18], ICDAR2015-HTR [19], and the newly introduced VML-AHTE dataset. To measure the performances, we adopted two different methods: the pixel level metrics from ICDAR 2013 handwriting segmentation contest [20], and the polygonal level metrics from Diva Line Segmentation Evaluator [21]. We show that the Mask R-CNN text line extraction obtains state-of-the-art results on Diva-HisDB, and can successfully extract text lines on the ICDAR2015-HTR, and VML-AHTE datasets--a pair of challenging scenarios in which documents include overlapping and crossed out lines and multiple diacritics, respectively.  
The remainder of this paper is organised as follows. In Section 2 related works for text line detection and text line extraction are reviewed. Section 3 provide background information about Mask R-CNN. The text line extraction method are described in Section 4, and the used datasets and evaluations are presented in Section 5 and Section 6, respectively. Section 7 present experimental results and discussion. Finally, we conclude and discuss future work in Section 8.
## 4 III-V-on-Silicon Devices for Optical Communication Applications
### III-V-on-Silicon Laser Sources for Optical Communication Applications
#### 4.1.4 1550 nm Distributed Feedback Dual Wavelength Laser Sources for THz Signal Generation  
The ever-increasing demand for bandwidth and mobile data transfer has driven the need for higher frequency carriers for wireless communications up to the THz range [31]. A promising technology to generate such carriers is optical heterodyning [32,33]. In this approach a dual-wavelength laser source is combined with a high-speed photodiode, typically a uni-travelling-carrier photodiode (UTC-PD). The beat between the two laser wavelengths generates the THz carrier. The integration of UTC-PDs on silicon photonic integrated circuits was recently demonstrated [34]. For the dual-wavelength laser implementation, several solutions have been proposed: a tailored spectrum Fabry-Perot laser [35], a multi-section distributed feedback (DFB) lasers [36] and a chip with two independent laser diodes [37]. In our work, an array of asymmetric DFB lasers was designed and fabricated using III-V-on-silicon technology [38]. In an asymmetric DFB laser, the quarter wave phase shift is placed away from the center, as illustrated in Figure 10a. The asymmetrical grating allows two longitudinal modes to lase at the same time (see Figure 10b), while a central phase shift typically results in single mode operation. To ensure stable dual-mode lasing, both modes must be spectrally positioned symmetrically around the gain peak. Instead of a single device, an array of asymmetric DFBs with slightly varying parameters was fabricated. As a result, independent of temperature or manufacturing variations a dual-wavelength device can be found in the array. A major advantage of an asymmetric DFB laser compared to a multi-section DFB laser [36] is that only one current source needs to be controlled. An advantage when compared to two independent laser diodes is that the two laser lines are emitted by the same cavity, therefore a more stable THz signal can be expected. The performance of the realized devices was assessed by connecting the output of the dual-wavelength DFB laser to a UTC-PD with integrated antenna [38]. The signal emitted by the antenna was collected by a WR 2.8 horn antenna and down-converted using an electronic mixer. This down-converted signal is then analyzed by an electrical spectrum analyzer. The linewidth of the carrier and its frequency drift are shown in Figure 10c,d. The instantaneous 3 dB-linewidth of the signal at 357 GHz is 4.2 MHz. A longer sweep of 30 s shows that the signal drifts 28 MHz. This performance allows for on-off keying wireless data transfer using envelope detection.
# A Novel Guided Box Filter Based on Hybrid Optimization for Medical Image Denoising
## 2 Digital Filter as Bio-Inspired Optimization Problem
### Noise Characteristics  
Noise in medical images can have a detrimental effect on diagnostic accuracy and clinical decisions. The noise characteristics depend on several factors, including the imaging modality, parameters, and anatomical region being imaged. Understanding the noise characteristics in medical images is essential for improving image quality and ensuring accurate diagnoses. Some common types of noise in medical images are:Gaussian noise: Gaussian noise is a type of statistical noise that can be artificially added to an image to simulate real-world noise. Gaussian noise typically affects the gray level \(z\) in digital images, characterized by its probability density function or normalized histogram to the gray level \(z\). It follows a bell-shaped curve around the mean value \(\mu\) and can significantly impact the quality of images, especially in regions with low contrast or subtle features. The probability density function \(\rho\) is represented as  
\[\rho(z)=\frac{1}{\sigma\sqrt{2\pi}}e^{-\frac{(z-\mu)^{2}}{2\sigma^{2}}} \tag{10}\]  
Poisson noise: Poisson noise is a type of statistical noise that occurs in digital images as random variations in the intensity of pixels due to the counting of discrete events, such as photons or particles. This noise can significantly impact the quality of medical images and affect the accuracy of diagnosis, especially in low-light or low-contrast images. It is important to consider the specific characteristics of Poisson noise when selecting and optimizing noise reduction methods to preserve image detail and sharp edges. The Poisson noise variance \(\eta^{2}(x)\) is characterized as  
\[\eta^{2}(x)=\alpha x \tag{11}\]  
Here, the Poisson noise parameter is \(\alpha\) with respect to the original image \(x\).  
Salt and pepper Noise: Salt and pepper noise is a common image distortion in digital images, caused by errors during image acquisition or transmission. It is characterized by noisy pixels alternating between the minimum and maximum intensity values. It can be expressed mathematically as  
\[f(x)=\begin{cases}i_{min}&\quad\text{with probability $p$}\\ i_{max}&\quad\text{with probability $q$}\\ u(x)&\quad\text{with probability $1-p-q$}\end{cases} \tag{12}\]  
Speckle Noise: Speckle noise is another image distortion that is commonly found in digital images. It is caused by random interference, resulting in random variations in brightness or darkness across the image. Noisy image \(I(x)\) is represented as  
\[I(x)=\varnothing x \tag{13}\]  
Here, the speckle noise parameter is \(\varnothing\) with respect to the original image \(x\).
# Geo-DMP: A DTN-Based Mobile Prototype for Geospatial Data Retrieval
## 3 Geo-DMP Mobile System
### The Workflow of Geo-DMP
#### 3.2.2 On the Perspective of Handling Incoming BPQ-Enabled Bundles  
Next, we take a closer look at what operations are performed inside intermediate DTN nodes and how BPQ works for content discovery during the multi-hop relay of BPQ-enabled bundles. Depending on different types of incoming bundle, the internal process can be discussed in three situations.  
_1. Upon Receipt of Newly Generated Query_  
When the DTN Daemon takes out one event indicating the arrival of a bundle from the event queue, the first step is to recognize the type and source of the bundle. The bundle will be identified  
Figure 4: The transformations between HTTP messages and delay/disruption tolerant network (DTN) bundles during the content retrieval procedure.  
as a query bundle when a BPQ Block is found in the bundle header and the value of the type field is \"query\". If the source EID is identical to that of the local node, it means this bundle is newly generated locally. As the creation of the query bundle only happens after the proxy fails to find the requested content at the local cache, this bundle cannot be satisfied at the moment. So it will be kept in the Bundle List to wait to be routed to other nodes or matched with incoming contents. This process is illustrated in Figure 5.
###### Abstract  
Bimanual telemanipulation is vital for facilitating robots to complete complex and dexterous tasks that involve two handheld objects under teleoperation scenarios. However, the bimanual configuration introduces higher complexity, dynamics, and uncertainty, especially in those uncontrolled and unstructured environments, which require more advanced system integration. This paper presents a bimanual robotic teleoperation architecture with modular anthropomorphic hybrid grippers for the purpose of improving the telemanipulation capability under unstructured environments. Generally, there are two teleoperated subsystems within this architecture. The first one is the Leap Motion Controller and the anthropomorphic hybrid robotic grippers. Two 3D printed anthropomorphic hybrid robotic grippers with modular joints and soft layer augmentations are designed, fabricated, and equipped for telemanipulation tasks. A Leap Motion Controller is used to track the motion of two human hands, while each hand is utilized to teleoperate one robotic gripper. The second one is the haptic devices and the robotic arms. Two haptic devices are adopted as the master devices while each of them takes responsibility for one arm control. Based on such a framework, an average RMSE (root-mean-square-error) value of 0.0204 rad is obtained in joint tracking. Nine sign-language demonstrations and twelve object grasping tasks were conducted with the robotic gripper teleoperation. A challenging bimanual manipulation task for an object with 5.2 kg was well addressed using the integrated teleoperation system. Experimental results show that the proposed bimanual teleoperation system can effectively handle typical manipulation tasks, with excellent adaptabilities for a wide range of shapes, sizes, and weights, as well as grasping modes.  
robotic teleoperation; bimanual manipulation; anthropomorphic hybrid gripper; modular design +
Footnote †: journal: Applied Physics Letters