nils-herrmann/clean_scirepeval huggingface dataset:
Automatic video-based human motion analyzer for consumer surveillance system

With the continuous improvements in video-analysis techniques, automatic low-cost video surveillance gradually emerges for consumer applications. Video surveillance can contribute to the safety of people in the home and ease control of home-entrance and equipment-usage functions. In this paper, we study a flexible framework for semantic analysis of human behavior from a monocular surveillance video, captured by a consumer camera. Successful trajectory estimation and human-body modeling facilitate the semantic analysis of human activities and events in video sequences. An additional contribution is the introduction of a 3-D reconstruction scheme for scene understanding, so that the actions of persons can be analyzed from different views. The total framework consists of four processing levels: (1) a preprocessing level including background modeling and multiple-person detection, (2) an object-based level performing trajectory estimation and posture classification, (3) an event-based level for semantic analysis, and (4) a visualization level including camera calibration and 3-D scene reconstruction. Our proposed framework was evaluated and has shown its good quality (86% accuracy of posture classification and 90% for events) and effectiveness, as it achieves a near real-time performance (6-8 frames/second).
Robust automatic ship tracking in harbours using active cameras

Radar is commonly used to detect and track ships in maritime surveillance. Unfortunately the systems are costly and do not provide any visual information about the object's type. To complement the ship identity information given by a radar system, we propose a supplementary system using active visual cameras that can robustly detect and track ships in harbours. By combining a high-quality, non real-time robust object detector with a feature point tracker with low computational complexity, it is possible to track ships in real time over long intervals and large distances. In addition to controlling pan and tilt, we dynamically control camera zoom to provide a high resolution image of the tracked object over a large range of distances. The tracking system is improved by a special motion estimation model for the feature points, which also incorporates zooming of the camera. The system is robust and sustains tracking even under challenging conditions, such as multiple viewpoints, a large variety of ships and various weather conditions. During experiments, various types of ships were successfully tracked for up to 18 minutes, and over a distance of almost 1.5km in the port of Rotterdam. The proposed system is generic and can be utilized in various tracking applications, by training the detector for a different object class.
Robust classification of traffic signs using multi-view cues

Traffic sign inventories are created for road safety and maintenance based on street-level panoramic images. Due to the large capturing interval, large viewpoint deviations between the different capturings occur. These viewpoint variations complicate the classification procedure, which aims at the selection of the correct sign type, out of a high number of nearly similar sign types, typically resulting in misclassifications. This paper describes a novel approach for incorporating viewpoint information to the classification procedure, where the sign orientation is estimated based on dense matching. Afterwards, each sample is corrected to a frontal viewpoint, which is then classified. Finally, the sign type is obtained by weighted voting. Large-scale experiments including 2, 224 traffic signs show that this approach reduces the misclassification rate by about 33% compared to the single-view case.
Reuse of macro frequencies in a micro cell system

In this paper, spectrum management is studied for a scenario with macro cells and contiguous micro cells covering the same urban area. The study is performed in a simulation environment based on detailed information of a city environment and using sophisticated propagation models. It is shown that frequencies from the macro cell layer can be reused in the micro layer to obtain a substantial capacity increase. Careful frequency planning is performed taking into account macro cell interference on a per cell basis in the micro layer as well as the interference relations between different micro cells. To be able to perform analysis and planning, input data from downlink interference measurements or advanced propagation calculations are vital.
Field Data logger prototype for power converters

Mission profile data is very important for the cost effective and reliable design of power converters. The converter design can be improved on the basis of actual field data. Actual mission profile data can be collected for the power converters using field data loggers over a long period of time and subsequent analysis of the data. This paper presents the development of a low cost prototype field data logger prototype using Raspberry PI and industrial sensors. The functionalities of the data logger prototype are described. An online rainflow count algorithm has been implemented as well.
An electromagnetic bandgap curl antenna for phased array applications

A promising way to reduce the problems created by surface waves in printed phased array antennas is to use an electromagnetic bandgap (EBG) substrate instead of a standard dielectric. Two metallo-dielectric EBG substrates well suited for phased array applications have been designed and tested. One of them has a compact unit cell and exhibits a broad bandwidth performance. The other EBG structure has a narrower bandwidth but is simple to manufacture and has a low mechanical profile. Single radiating elements and a small linear array have been manufactured on a standard dielectric substrate and on the EBG substrates. The measurements show a significant improvement in radiation efficiency as well as of the front to back ratio for the antennas manufactured on the EBG substrates compared to the ones obtained for the antennas manufactured on the standard dielectric substrate. These results clearly demonstrate the effectiveness of the EBG substrates in reducing the surface and guided waves.
Optimization of a 250-GHz Schottky tripler using novel fabrication and design techniques

A technique for optimizing a diode waveguide mount for millimeter- and submillimeter-wave applications has been developed. The structure consists of a planar rectangular radiator for which an accurate derivation of impedance is available. The planar radiating probe incorporates the diode contacting tip, is fabricated integrally with the microstrip filter, and is used in a 230-290-GHz frequency tripler. Modification of the tripler using the described technique resulted in an improvement of /spl ap/6 dB in available output power, compared to the authors' previous results for this device. Device output power exceeds 8.5 mW at 245 GHz for an input power of 132 mW. The best flange-to-flange efficiency (in excess of 11%) was achieved at 3.3-mW output power. This technique was then applied to a waveguide mount, incorporating two diodes contacted in parallel, so that greater input power could be handled. This resulted in a tripler with a maximum output power of 15 mW at 270 GHz for an input of 280 mW.
Stochastic control of a processor sharing queue with partial state information

A queuing model of a telephone switch is considered. The model consists of one server where two different types of customers arrive according to two independent Poisson processes with arrival rates lambda /sub 1/ and lambda /sub 2/, respectively. A type-1 customer responds with a call request and a type-2 customer with an operator or maintenance task. The customers are attended to by a single server that works according to the processor-sharing discipline. The author's goal is to design a control law that regulates the admission of new customers in order to keep the mean sojourn times at a reasonable level. His attention is restricted to control laws that use only partial state information, i.e. the decision to admit a new customer of type i depends only on the number of type-i customers present in the queue. A lemma is presented to determine the existence of an optimal critical-level policy.<<ETX>>
Micromagnetic Modelling of the Dynamics of Exchange Springs in Multi-Layer Systems

Exchange springs are formed in multilayers of alternating hard and soft ferromagnetic materials which are exchange coupled at their interfaces. These systems are rich of interesting physical properties, which can be tuned by selecting suitable geometries and compositions. In this paper, we present a computational study of the dynamics of a tri-layer DyFe2/YFe2/DyFe2 exchange spring system near the bending field (the field required to twist the magnetization of the soft YFe2 layer out of the aligned state). The dynamical reaction of the system to small variations of the applied field is studied and its oscillatory nature is analyzed numerically. The behaviors of the decay times, the frequencies, and amplitudes reveal enhanced responses of the system near the bending field
DAC-less and DSP-free PAM-4 Transmitter at 112 Gb/s with Two Parallel GeSi Electro-Absorption Modulators

We present a novel integrated PAM-4 modulator based on the vector addition of 2 binary driven parallel GeSi electro-absorption modulators. Clear open eyes at 56 GBaud up to 2 km of SSMF without any DSP are demonstrated.
High Quality Epitaxial Germanium on Si (100) for low -cost III–V Solar-Cells

Integration of high quality germanium on silicon is prerequisite for fabricating high efficiency low-cost III-V solar cells on silicon. In this work, we present a method of monolithic integration of epitaxial germanium on crystalline silicon wafers where a single-step anneal in hydrogen ambient is used to recrystallize PECVD-deposited amorphous germanium into crystalline germanium. The re-crystallization progresses via liquid phase epitaxy by heating the germanium layer in inert ambient to just above its melting temperature of 937 °C. On cooling, the Ge layer gets oriented by the underlying Si (100) wafer, yielding an epitaxial Ge film on Si. SEM show that the films are continuous and void free. XRD pattern indicates highly oriented films. Symmetric Rocking curve measurements showed a thickness dependence with 1 µm thick film showing the lowest threading dislocation density (TDD) of the order of 108 cm−2. AFM measurements indicate surface measurements ~10 nm. Quality of epitaxy depends on thickness of film.
Planar simplification and texturing of dense point cloud maps

Dense RGB-D based SLAM techniques and high-fidelity LIDAR scanners are examples from an abundant set of systems capable of providing multi-million point datasets. These large datasets quickly become difficult to process and work with due to the sheer volume of data, which typically contains significant redundant information, such as the representation of planar surfaces with hundreds of thousands of points. In order to exploit the richness of information provided by dense methods in real-time robotics, techniques are required to reduce the inherent redundancy of the data. In this paper we present a method for efficient triangulation and texturing of planar surfaces in large point clouds. Experimental results show that our algorithm removes more than 90% of the input planar points, leading to a triangulation with only 10% of the original amount of triangles per planar segment, improving upon an existing planar simplification algorithm. Despite the large reduction in vertex count, the principal geometric features of each segment are well preserved. In addition to this, our texture generation algorithm preserves all colour information contained within planar segments, resulting in a visually appealing and geometrically accurate simplified representation.
Maximum likelihood thresholding algorithm based on four-parameter gamma distributions

In this contribution, we present a segmentation algorithm based on thresholding to subdivide an intensity image in the regions of object and background. The optimal threshold is found by maximizing a likelihood function derived from a novel intensity probability density function model, which consists of the sum of two weighted four-parameter gamma distributions, as a more flexible alternative to currently used models consisting of the sum of two weighted two-parameter Gaussian distributions. According to our experiments with 132 images, the proposed algorithm is in average slightly better than the best found in the scientific literature, performing particularly good in low contrast images. The additional parameters and complexity of its likelihood function resulted in an increase of the processing time by a factor of 3, from 0.003 sec/image to 0.009 sec/image.
Computational-complexity scalable motion estimation for mobile MPEG encoding

Complexity scalability algorithms are important for mobile consumer devices using MPEG video coding, because they offer a trade-off between picture quality and the embedded available computational performance. This paper presents a new scalable three-stage motion estimation technique, which includes preprocessing of frames in display order and approximation of motion-vector fields using multiple temporal references. A quality refinement of the approximation is added as an optional stage. Furthermore, we present a new scalable motion-estimation algorithm, based on simple edge detection, for integration into the above-mentioned new three-stage motion estimation technique. The complete system provides a flexible framework with a large scalability range in computational effort, resulting in an output quality that scales up smoothly with the number of operations spent on the motion estimation process. Experiments show a scalable computational effort from below one SAD (sum of absolute difference) computation per macroblock up to 15 SAD computations, resulting in a global variation of 7.4 dB PSNR in picture quality (with the "Stefan" sequence). In high-quality operation, the new algorithm is comparable to (or even outperforms) a full-search motion estimation with a search window of 32/spl times/32 pixels.
Improved Latency Performance with GSM/EDGE Continued Evolution

The world's largest and most widespread cellular technology today is GSM/EDGE. EDGE is capable of offering an attractive solution for 3rd generation cellular services in existing GSM networks. However, the introduction of new and more delay sensitive services may require improved latency performance. Reducing the delay and increasing the bandwidth efficiency in EDGE systems is important for services with stringent latency requirements, such as conversational VoIP, but will be beneficial also to other services. Proposed is to reduce the transmission time interval from 20 ms to 10 ms, in combination with novel procedures for faster feedback. Simulation results show that LLC delays may be reduced by 20-40% depending on traffic scenario. Furthermore, channel resource requirements for VoIP could be substantially reduced.
Near-Future Streaming Framework for 3D-TV Applications

This paper presents a layered framework for 3D-TV applications, combining multiview and depth-image based approaches in a scalable fashion. To solve the problem of missing data due to disocclusions, we add specific layers for coded occlusion data and the edge-mask information for high-quality 3D rendering of key objects in the scene. We show how the same framework can be extended towards FTV applications by jointly addressing simulcast and multicast transmission. By adopting a distributed delivery architecture, new interesting properties can be realized such as shared processing for the creation and streaming of virtual viewpoints
Planar circularly symmetric EBG structures for reducing surface waves in printed antennas

This paper discusses the design and analysis of planar circularly symmetric (PCS) electromagnetic band gap (EBG) structures for reducing the surface waves excited by printed antennas on dense dielectric substrates. The key advantage of the circularly symmetric geometries is that a surface wave generated by a source located at its center experiences the same band gap effect in all radial directions. To obtain simple design rules of the PCS-EBGs for the optimization of the bandwidth, an equivalence is established between 2-D-EBGs and PCS-EBGs. Integrated planar printed antennas with bandwidths up to 20% are designed, manufactured and tested.
SCTP as mobility protocol for enhancing internet on the train

Internet-on-the-train is a rising concept in the last few years. Several trials in different countries have proved the feasibility of offering Internet access to train commuters, but none of them combines broadband access, scalability, seamless handover and quality of service guarantees in one solution. In this paper, we look at the features of SCTP and its extensions which could overcome these shortcomings and which were successfully demonstrated.
Real-time video content analysis tool for consumer media storage system

With the growing storage capacities of hard-disks and optical discs, large consumer video databases are gradually developing. The large effective storage capacity using compressed video leads to the application of fast storage and retrieval functions, to enable quick user-friendly searching for and access to specific parts of the video data. We explore the feasibility of a near real-time semantic sports video analyzer for an experimental consumer media server. This tool is able to automatically extract and analyze key events in a video sequence. The analyzer employs several visual cues and a model for real-world coordinates, so that key parameters (e.g. speed and position) of a player can be determined with sufficient accuracy. This special data can be stored as metadata, thereby facilitating intelligent searching of events. The tool consists of four processing steps: (1) playing frame detection, (2) court extraction, as well as a 3-D camera model, (3) player segmentation and tracking, and (4) event-based high-level analysis exploiting visual cues extracted in the real-world. Our system has been evaluated in a new distributed AV content analysis system for home entertainment. We show attractive experimental results indicating the system efficiency and classification skills, thereby offering new analysis and search/retrieval tools to the consumer
Optimal Control of End-User Energy Storage

An increasing number of retail energy markets show price fluctuations, providing users with the opportunity to buy energy at lower than average prices. We propose to temporarily store this inexpensive energy in a battery, and use it to satisfy demand when energy prices are high, thus allowing users to exploit the price variations without having to shift their demand to the low-price periods. We study the battery control policy that yields the best performance, i.e., minimizes the total discounted costs. The optimal policy is shown to have a threshold structure, and we derive these thresholds in a few special cases. The cost savings obtained from energy storage are demonstrated through extensive numerical experiments, and we offer various directions for future research.
High capacity strategies for GSM/EDGE - impacts on data traffic performance

GSM is the world's most widespread cellular technology. With EDGE packet data, an attractive solution to offer 3rd generation cellular services in existing GSM networks is provided. The introduction of new services into an existing network typically leads to increased capacity demands, since more users of different service types need to coexist in a limited spectrum, while the existing speech service is required to function at least as well as before. In GSM/EDGE systems, the highest capacity is reached in interference-limited scenarios, typically realized with tight frequency reuse and fractional loading; see for example P. de Bruin et al. ( 2002). In such systems, methods for mitigating interference are needed to achieve maximum performance. Strategies for frequency hopping, inter-cell synchronization and MAIO (mobile allocation index offset) planning becomes increasingly important. The paper examines the impact these methods have on EDGE packet data performance. It is shown that packet data traffic responds differently than speech to interference diversity, mainly due to differences in channel coding and radio protocol characteristics. However, it is demonstrated that the intercell synchronization and MAIO planning strategies preferred for pure speech networks also offer substantial performance improvements for EDGE packet data.
Submillimeter Wave Frequency Selective Surface With Polarization Independent Spectral Responses

This paper reports the design, construction and electromagnetic performance of a new freestanding frequency selective surface (FSS) structure which generates coincident spectral responses for dual polarization excitation at oblique angles of incidence. The FSS is required to allow transmission of 316.5-325.5 GHz radiation with a loss les 0.6 dB and to achieve ges 30 dB rejection from 349.5-358.5 GHz. It should also exhibit crosspolarization levels below -25 dB, all criteria being satisfied simultaneously for TE and TM polarizations at 45 deg incidence. The filter consists of two identical, 30 mm diameter, 12.5 mum thick, optically flat, perforated metal screens separated by 450 mu m. Each of the ap 5000 unit cells contains two nested, short circuited, rectangular loop slots and a rectangular dipole slot. The nested elements provide a passband spectral response centered at 320 GHz in the TE and TM planes; the dipole slot increases the filter roll-off above resonance. The FSS was fabricated from silicon-on-insulator wafers using precision micromachining and plating processes including the use of deep reactive ion etching (DRIE) to pattern the individual slots and remove the substrate under the periodic arrays. Quasi-optical transmission measurements in the 250-360 GHz range yielded virtually identical copolarized spectral responses, with the performance meeting or exceeding the above specifications. Experimental results are in excellent agreement with numerical predictions.
EBG enhanced reflector feeds for wide angle scanning applications

This work is an extension of a series of works on the use of dielectric super-layers to shape the radiation pattern of each feed composing a focal plane imaging array. Using dielectric super-layers, the spill over from the reflectors are reduced without increasing the dimensions of each aperture. These effects are achieved when the inter-element distance between the feeds is large (2.4 wavelengths) which is typical for satellite based multi beam telecommunication applications. The shaping of the pattern is obtained with the excitation of a pair (TE/TM) of leaky waves, that radiate incrementally as they propagate between the ground plane and the super-layer. The super-layer can be realized with single dense dielectric slab ( epsivr=20.25) a double dielectric slab (epsivr=4.5) or an equivalent frequency selective surface. The maximum edge of coverage enhancement, with respect to reference free space configurations, that can be obtained in the different cases is equivalent. However the bandwidth over which the enhancement is maintained depends on how the super-layer is realized. The calculated embedded patterns provide an increase of the edge of coverage gain, with respect to the free space case, of at least 1.5 dB in an operating bandwidth of 3%. During the oral presentation the hardware manufactured to implement the previous concepts, including the filters for the frequency and reuse scheme, will be shown. Also the measured results will be compared with the simulations.