nils-herrmann/clean_scirepeval huggingface dataset:
Integration of virtual and remote experiments into undergraduate engineering courses

Experiments play an important role in the education of undergraduate engineering students as they provide hands-on experience on the foundations of the discipline. Unfortunately, the recent change of the university program in Germany from the Diploma to the Bachelor/Master model had a direct negative impact on the curricula and the course schedules. The result of which is that the first-year curriculum is overloaded; exercises or practical courses have been dropped altogether from the first term, have been rescheduled to later terms and have been reduced in length. For this reason, other forms of experimenting have to be developed and integrated into the existing courses or lectures; virtual laboratories and remote experiments offer such an option: they enable students to access equipment 24h/7 days a week, they are independent from opening hours and the work schedule of the staff. Furthermore, simulations do have some other advantages: they provide a better control on the simulated phenomenon, allow observing effects and running experiments that are only very hard to measure or perform in practical applications. Another advantage besides their cost-efficiency is that simulations allow observations of effects in a simplified environment without any measurement errors.
JPEG XT: A New Family of JPEG Backward-Compatible Standards

The Joint Photographic Experts Group recently produced a new standard, JPEG eXTension. JPEG XT is both backward-compatible with legacy JPEG and offers the ability to encode images of higher precision and higher dynamic range, and in lossy or lossless modes. Here, the authors shed some light on the recent developments of the JPEG committee and discuss both the current status of JPEG XT and its future plans.
Analysis of mesh-based motion compensation in wavelet lifting of dynamical 3-D+t CT data

Factorized in the lifting structure, the wavelet transform can easily be extended by arbitrary compensation methods. Thereby, the transform can be adapted to displacements in the signal without losing the ability of perfect reconstruction. This leads to an improvement of scalability. In temporal direction of dynamic medical 3-D+t volumes from Computed Tomography, displacement is mainly given by expansion and compression of tissue. We show that these smooth movements can be well compensated with a mesh-based method. We compare the properties of triangle and quadrilateral meshes. We also show that with a mesh-based compensation approach coding results are comparable to the common slice wise coding with JPEG 2000 while a scalable representation in temporal direction can be achieved.
On the JPEG 2000 ultrafast mode

Recently, the JPEG committee discussed the introduction of an “ultrafast” mode for JPEG 2000 encoding. This considered extension of the JPEG 2000 framework replaces the EBCOT coding by a combined Huffman-Runlength code, and adds an optional additional prediction step after quantization. While the resulting codec is not compatible with existing JPEG 2000, it still allows lossless transcoding from JPEG 2000 and back, and performance measurements show that it offers nearly the quality of JPEG 2000 and similar quality than JPEG XR at a much lower complexity comparable to the complexity of the IJG JPEG software. This work introduces the extension, and compares its performance with other JPEG standards and other extensions of JPEG 2000 currently under standardization.
Spatial Constant Quantization in JPEG XR is Nearly Optimal

The JPEG XR image compression standard, originally developed under the name HD-Photo by Microsoft, offers the feature of spatial variably quantization; its codestream syntax allows to select one out of a limited set of possible quantizers per macro block and per frequency band. In this paper, an algorithm is presented that finds the rate-distortion optimal set of quantizers, and the optimal quantizer choice for each macro block. Even though it seems plausible that this feature may provide a huge improvement for images whose statistics is non-stationary, e.g. compound images, it is demonstrated that the PSNR improvement is not larger than 0.3dB for a two-step heuristics of feasible complexity, but improvements of up to 0.8dB for compound images are possible by a much more complex optimization strategy.
A global image fidelity metric: Visual distance and its properties

The purpose of full reference image quality indices like Mean Square Error (MSE) or SSIM is to predict the judgement of human observers in subjective quality assessment tasks. More advanced indices like SSIM or VIF are, however, rarely metrics in the strict sense, i.e. they don't define a distance between pairs of images that would describe how far these images are related. It was shown in a recent work, however, that SSIM can be "integrated" to such a global metric, in the following called Visual Distance, which behaves locally like SSIM, but globally like a distance in a curved space. It was also seen that the Visual Distance between two images can be interpreted as the number of almost invisible image deformations to transform one image into another. In this work, properties of Visual Distances will be discussed; these results will allow to extend the result from SSIM to its multi-scale variant MS-SSIM. It will also seen that human judgement will typically not define a metric, but it is conjectured that scores and Visual Distances are related by a monotonie Judgement Function. If so, it will be seen that the underlying Visual Distance can always be reconstructed from the scores up to a proportionality factor defined by the scale of the score.
Embedding virtual and remote experiments into a cooperative knowledge space

Today, experimental environments and setups in natural sciences and engineering are neither available sufficiently, nor accessible enough to cover the broad demand. Yet, they form an essential part of the scientific methodology within the technological disciplines. Additionally, the ability to cooperate and work in teams when performing experiments is crucial. By integrating experimental setups into a virtual cooperative knowledge space, availability and accessibility can be enhanced for a wide range of people, working individually or in groups, making them independent of limitations in time, budget or access to classical laboratories. This article describes a SOAP-based architecture by which this objective can be achieved, and which is currently being implemented for CURE, a room-based cooperative knowledge space platform developed at FernUniversitaet Hagen.
Overview of JT-60SA HTS Current Lead Manufacture and Testing

The Karlsruhe Institute of Technology (KIT) agreed to construct and test the high-temperature superconductor (HTS) current leads for the tokamak JT-60SA presently under construction in the frame of the Broader Approach agreement between Europe and Japan. In total 6 HTS-CLs for 25.7 kA for the TF coils and 20 HTS-CLs for 20 kA for the PF and CS coils are needed. In addition, the acceptance tests of the HTS current leads were performed in the test facility CuLTKa at KIT. The manufacturing started in 2014 and the last current leads were tested in July 2017. The main parts of the acceptance test are the determination of the heat load at 4 K and the 50 K He mass flow rate through the heat exchanger as well as the simulation of a loss of flow accident. One test of the PF current leads also included a pulse test at 20 kA to demonstrate their PF operation capability. In this paper, an overview of the manufacture and acceptance tests of the HTS current lead is given. The results for the different current leads are summarized and compared to the specifications.
Transmission of Single-Channel 16-QAM Data Signals at Terabaud Symbol Rates

We present latest results for OTDM transmission systems in combination with digital coherent detection achieving record-high serial data rates in a single-wavelength channel. We show serial data transmission of 5.1 Tb/s (640 GBd) over 80-km and 10.2 Tb/s (1.28 TBd) over 29-km dispersion managed fiber (DMF). For 5.1-Tb/s transmission over 80-km DMF, the BER of all 128 OTDM-tributaries (both polarizations) is found to be below the hard-decision FEC-threshold, corresponding to an error-free net data rate of 4.8 Tb/s. In a 10.2-Tb/s experiment, the BER of all 256 TDM-tributaries (both polarizations) is found to be below the FEC-threshold in the back-to-back configuration. This translates to an error-free net data rate of 9.5 Tb/s. After transmission over a 29-km DMF negligible pulse broadening and a BER below the FEC limit is found.
A platform-based highly parallel digital signal processor

Realizations of demanding applications particularly in the field of mobile communications often require processing performance which is far beyond what is delivered by DSPs today. To avoid designing inflexible ASIC solutions a powerful, highly parallel DSP core for System-on-Chip domains is presented in this paper. Targeted for a wireless OFDM based modem application the fixed-point DSP core consists of 16/spl times/16-bit datapath units in parallel providing 640 M MAC operations per second. In a Galois field split mode 32 8-bit datapaths deliver 1.28 G MAC/s. The DSP is based on a scalable architecture which supports customization depending on the application needs. The 289 mm/sup 2/ chip was manufactured in a 0.35 /spl mu/m CMOS technology, operates at 40 MHz and dissipates <1 W from a 3.3 V supply. This low power approach outperforms commercial DSPs running at 200 MHz.
Reconstruction of images taken by a pair of non-regular sampling sensors using correlation based matching

Multi-view image acquisition systems with two or more cameras can be rather costly due to the number of high resolution image sensors that are required. Recently, it has been shown that by covering a low resolution sensor with a non-regular sampling mask and by using an efficient algorithm for image reconstruction, a high resolution image can be obtained. In this paper, a stereo image reconstruction setup for multi-view scenarios is proposed. A scene is captured by a pair of non-regular sampling sensors and by incorporating information from the adjacent view, the reconstruction quality can be increased. Compared to a state-of-the-art single-view reconstruction algorithm, this leads to a visually noticeable average gain in PSNR of 0.74 dB.
The WebLabs of the University of Cambridge: A study of securing remote instrumentation

Safe deployment of web interfaces for remote instrumentation requires that the laboratory system be protected from harmful manipulation by end users or attacks from malicious software over the internet. Industrial control systems, although highly relevant to contemporary engineering education and an essential component of many remote experiments, are typically only designed to run in a secured local area network and cannot safely be exposed to the internet because they lack a sufficiently robust security infrastructure. They also typically require the installation of proprietary software on the end user system which is an obstacle for deployment in learning scenarios at universities. Facing these challenges when bringing the Chemical Engineering WebLabs at the University of Cambridge online, the Computing Center of the University of Stuttgart and the University of Cambridge developed a framework to allow the secure deployment of industrial controller software in remote learning applications; this framework is generic, has a low-barrier for students as it only requires an internet browser and Java™ installation, and it satisfies the high security demands of most university infrastructure providers. Furthermore, the framework has the potential to be applied to almost any remote laboratory setup and is compatible with all commonly-used operating systems at the user end.
Qualitative Comparison of Kerr Nonlinearity Mitigation Schemes in a Dispersion-Managed Link for 4 × 28-GBd 16-QAM Signals

We present an experimental investigation of different Kerr nonlinearity mitigation schemes in a 2-span dispersion-compensated link of 160-km length for 4 × 28-GBd single-polarization 16-QAM signal transmission. We consider optical phase conjugation (OPC) based on mid-link spectral inversion, digital backpropagation (DBP), and transmission of phase-conjugated twin-waves with either digital coherent superposition (DCS) or all-optical coherent superposition employing phase-sensitive amplification (PSA). The experiments are performed in a single-channel and a wavelength-division multiplexing (WDM) scenario. For single-channel operation, phase-conjugated twin waves with DCS provided superior performance compared to all the other mitigation schemes with a maximum Q2-factor improvement of 1.7 dB compared to signal transmission without any nonlinearity mitigation. The DBP, however, showed a higher nonlinear threshold than all the other schemes in our experiments. In the WDM scenario, DBP showed worse performance than the other mitigation schemes whereas the DCS again provided a higher Q2-factor improvement than the other techniques with a maximum Q2-factor improvement of 1.9 dB. The PSA and the mid-link OPC showed similar nonlinearity mitigation performance both in single-channel and WDM scenarios.
Lossless Coding Extensions for JPEG

The issue of backwards compatible image and video coding gained some attention in both MPEG and JPEG, let it be as extension for HEVC, let it be as the JPEG XT standardization initiative of the SC29WG1 committee. The coding systems work all on the principle of a base layer operating in the low-dynamic range regime, using a tone-mapped version of the HDR material as input, and an extension layer invisible to legacy applications. The extension layer allows implementations conforming to the full standard to reconstruct the original image in the high-dynamic range regime. What is also common to all approaches is the rate-allocation problem: How can one split the rate between base and extension layer to ensure optimal coding? In this work, an explicit answer is derived for a simplified model of a two-layer compression system in the high bit-rate approximation. For a HDR to LDR tone mapping that approximates the well-known sRGB non-linearity of ? = 2.4 and a Laplacian probability density function, explicit results in the form of the Lambert-W-function are derived. The theoretical results are then verified in experiments using a JPEG XT demo implementation.
Memory efficient lossless compression of image sequences with JPEG-LS and temporal prediction

In this paper, a lossless encoder for image sequences based on JPEG-LS defined for still images with temporal-extended prediction and context modeling is proposed. As embedded systems are one important field of application of the codec, on-line lossy reference frame compression is used to reduce the encoder's memory requirement. Variations of the pixel values in the reference frame due to lossy compression are acceptable since the predictor provides only estimations of the pixel values being encoded in the current frame. Larger variations decrease the final lossless compression performance of the encoder such that a trade-off between the memory requirement and the overall compression ratio is required. Different compression algorithms for the reference frame, including JPEG, JPEG 2000 and near-lossless JPEG-LS, and their impacts on the memory requirement and the overall lossless compression ratio have been studied. Experimental results show 9.6% or more gain in lossless compression ratio compared to applying the standard JPEG-LS frame-by-frame and 80% reduction in the encoder buffer size compared to storing the uncompressed reference frame.
Non-reciprocal gain due to counter-propagating pumps in a polarization-independent FOPA with diversity loop

We investigate limitations set on single-pump polarization-independent fiber-optical parametric amplifier (FOPA) using polarization-maintaining highly nonlinear fiber in a diversity loop. We show that Brillouin scattering between the counter-propagating pumps yields polarization-dependent gain if an asymmetric local dispersion profile is present.
High Throughput Coding of Video Signals

As the resolution of monitors and TVs continue to increase, the available bandwidth between host system and monitor becomes more and more a bottleneck. The Video Electronics Standards Association (VESA) is currently developing standards for screen resolutions beyond 4K and, facing the problem of not having enough bandwidth available on traditional copper wires, contacted the JPEG to develop a low complexity, high-throughput still image coder for lossy transmission of video signals. This article describes two approaches to address this predicament, a simple SPIHT based coded and a Hadamard based embedded codec requiring only minimal buffering at encoder and decoder side, and avoiding any pixel-based feedback loops limiting the operating frequency of hardware implementations. Analyzing the details of both implementations reveals an interesting connection between run-length coding, as found in the progressive mode of traditional JPEG coding, and SPIHT/EZW coding - a technique popular in wavelet based compression techniques.
Perceptual image coding by standard-constraint codecs

A perceptual image compression codec exploits the characteristics of the human senses to minimize the perceivable quality loss of digital images under compression. Such a codec has an even higher value if the resulting codestreams are compatible to an existing standard, and are thus decodeable by all-day, existing applications. This work describes strategies how to implement perceptual coding in standardized environments, namely JPEG, JPEG 2000 and JPEG-XR.
A MS-SSIM Optimal JPEG 2000 Encoder

In this work, we present a SSIM optimal JPEG 2000 rate allocation algorithm. However, our aim is less improving the visual performance of JPEG 2000, but more the study of the performance of the SSIM full reference metric by means beyond correlation measurements.Full reference image quality metrics assign a quality index to a pair of a reference and distorted image. The performance of a metric is then measured by the degree of correlation between the scores obtained from the metric and those from subjective tests. It is the aim of a rate allocation algorithm to minimize the distortion created by a lossy image compression scheme under a rate constraint.Noting this relation between objective function and performance evaluation allows us now to define an alternative approach to evaluate the usefulness of a candidate metric: we want to judge the quality of a metric by its ability to define an objective function for rate control purposes, and evaluate images compressed in this scheme subjectively. It turns out that deficiencies of image quality metrics become much easier visible --- even in the literal sense --- than under traditional correlation experiments.Our candidate metric in this work is the SSIM index proposed by Sheik and Bovik which is both simple enough to be implemented efficiently in rate control algorithms, but yet correlates better to visual quality than MSE; our candidate compression scheme is the highly flexible JPEG 2000 standard.
Knowledge Management in mArachna

Machine-readable semantic annotation of scientific knowledge is becoming increasingly important to manage and access the knowledge contained in an increasing number of scientific publications. At the same time, automated extraction of knowledge from natural language texts is a major technical challenge remaining largely unsolved. Scientific texts in general and mathematical texts in particular, are characterized by the use of complex language constructs with the intent to transfer knowledge. To a large extent, mathematical texts possess a strict internal structuring and can be separated into text elements such as definitions, theorems etc. These text elements are principal carriers of mathematical information. In addition, these elements show a characteristic linguistic structuring well suited for natural language processing techniques. In this paper we present mArachna, a system for extracting mathematical relations from texts and integrating them into a knowledge base. In response to user queries, parts of the knowledge base are visualized using OWL. In particular, mArachna aims to provide an overview of single fields of mathematics, as well as showing intra-field relations between mathematical objects and concepts
Optical phase conjugation for nonlinearity compensation in WDM PDM 16-QAM transmission over dispersion-compensated and dispersion-uncompensated links

Kerr nonlinearity compensation by optical phase conjugation is demonstrated in a WDM PDM 16-QAM system. Improved received signal quality is reported for both dispersion-compensated and dispersion-uncompensated transmission and a comparison with digital backpropagation is provided.
Compressing JPEG 2000 JPIP Cache State Information

JPEG 2000 part 9, or short JPIP, is an interactive image browsing protocol that allows the selective delivery of image regions, components or scales from JPEG 2000 image. Typical applications are browsing tools for medical databases where transmitting huge images from server to client in total would be uneconomical. Instead, JPIP allows extracting only the desired image parts for analysis by an http type request syntax. Such a JPIP connection may either operate in a session within which the server remains aware of the image data already cached at the client and it hence doesn't have to transmit again, or it may operate in a stateless mode in which the server has no model of the data already available on the client. In such cases, the client may include a description of its cache model within a proceeding request to avoid retransmission of data already buffered. Unfortunately, the standard defined methods how such cache models are described are very inefficient, and a single request including a cache model may grow several KBytes large for typical images and requests, making the deployment of a JPIP server on top of existing http server infrastructure rather inconvenient. In this work, a lossy and loss less embedded compression scheme for such JPIP cache model adjustment requests based on a modified zero-tree algorithm is proposed, this algorithm works even in constraint environments where request size must remain limited. The proposed algorithm losslessly compresses such cache model adjustment requests often better than by a factor of 1:8, but may even perform a 1:8000 compression in cases where the cache model has to describe a large number of precincts.
Hybrid-Integrated Polarization Diverse Coherent Receiver Based on Polymer PLC

A dual-polarization coherent receiver using polymer planar lightwave circuit technology is demonstrated for the first time. It comprises optical 90 hybrids on the basis of polymer waveguides, polarization beam-splitting thin-film elements, and photodetectors made of InGaAsP/InP. The chip size fits into the existing receiver package standards. The receiver assembly shows a high polarization extinction ratio (>;25 dB over C-band) and is successfully operated in system experiments with 16-quadrature-amplitude modulation and quadrature phase-shift keying modulation up to 112 Gb/s.
Coherent reception and 126 GHz bandwidth digital signal processing of CO-OFDM superchannel generated by fiber frequency conversion

We implement 126-GHz bandwidth coherent receiver and demonstrate multi-channel reception with nonlinear compensation (NLC) of a precisely frequency-allocated four-channel 28-GBd-QPSK OFDM superchannel sequentially aggregated using fiber-optic signal processing. Multi-channel back propagation-based NLC improved transmission performance.
Versatile coherent in-line 4-, 16-, 32-QAM subcarrier add/drop-multiplexing by optical frequency conversion

We experimentally investigate the modulation format scalability & agility of a coherent add/drop node. Extinction of 25 dB yields OSNR penalties up to 1.1-dB for 3.2-GBd intra-format subcarrier add/drop up to 32QAM and 0.8-dB for inter-format 4QAM-by-16QAM add/drop.