nils-herrmann/clean_scirepeval huggingface dataset:
Biomass tomography: A new opportunity to observe the earth forests

The next ESA Earth Explorer Core Mission BIOMASS is envisaged to collect multiple baselines on selected areas during the initial phase of its lifetime. Such data will allow to image the vertical structure of the vegetation layer to within a vertical resolution of about 20 m, sufficient to decompose the backscattered power from a tropical forest into two-three layers. The information provided by tomography has recently been shown to be strictly linked to above ground biomass (AGB) in tropical forest, therefore providing a valuable tool for ABG estimation. The aim of this paper is to present a bird-eye overview of BIOMASS Tomography, along with the main experimental results from airborne campaigns flown during Phase-A BIOMASS activities.
Bounded asymmetric mixture model for medical image segmentation

Segmentation of medical image based on the modeling and estimation of the tissue intensity probability density functions via Gaussian mixture model (GMM) has recently received great attention. However, Gaussian distribution is unbounded and symmetrical around its mean. This study presents a new bounded asymmetric mixture model for analyzing both univariate and multivariate data. The advantage of the proposed model is that it has the flexibility to fit different shapes of observed data such as non-Gaussian, non-symmetric, and bounded support data. Another advantage is that each component of the proposed model has the ability to model the observed data with different bounded support regions, which is suitable for application on image segmentation. Our method is intuitively appealing, simple, and easy to implement. We also propose a new method to estimate the model parameters in order to minimize the higher bound on the data negative log-likelihood function. Numerical experiments are presented where the proposed model is tested in various images from simulated to real 3D medical ones.
A customizable visualization framework for VANET application design and development

Prototyping distributed applications for VANETs requires an accurate large-scale simulation scenario where many nodes interact with one another in a complex way. To test and troubleshoot the application, node states and their evolution must be inspected. This process can be made easier by an interactive graphical user interface showing the distributed state at different levels of detail. In this paper, we propose ELVS, a general purpose visualization framework encapsulating a VANET simulator based upon JiST/SWANS and SUMO: by customizing data representation, ELVS allows displaying and investigating complex application-specific behaviors. The tool enables the implementation and rapid validation of an application against a large-scale scenario, supporting the developer in debugging distributed algorithms.
A robust non-symmetric mixture models for image segmentation

Finite mixture model with symmetric distribution has been widely used for many computer vision and pattern recognition problems. However, in many applications, the distribution of the data has a non-Gaussian and non-symmetric form. This study presents a new non-symmetric mixture model for image segmentation. The advantage of our method is that it is simple, easy to implement and intuitively appealing. In this paper, each label is modeled with multiple D-dimensional Student's-t distribution, which is heavily tailed and more robust than Gaussian distribution. Expectation maximization (EM) algorithm is adopted to estimate model parameters and to maximize the lower bound on the data log-likelihood from observations. Numerical experiments on various data types are conducted. The performance of the proposed model is compared to other mixture models, demonstrating the robustness, accuracy and effectiveness of our method.
An adaptive beamforming algorithm for antenna array applied to an MC-CDMA system with co-channel interference

In this paper, we propose an adaptive beamforming algorithm, called MC-LMS, for adaptive antenna applied to an MC-CDMA system. New method for updating the weight vector based on the MSE criterion is derived. Computer simulations show that MC-LMS algorithm is capable of rejecting co-channel interference that affects the MC-CDMA system. Thus, the BER performance of the MC-CDMA system is much higher than that of the MC-CDMA system without using adaptive antenna and that of the DS-CDMA system with adaptive antenna in multipath Rayleigh fading channel.
A flexible receiver using ΔΣ modulation

This paper presents a reconfigurable 2nd/3rd-order discrete-time direct RF-to-digital ΔΣ receiver architecture for wide frequency range flexible receivers. Using 25% duty-cycle current-driven passive mixer along with RF feedback enables high-Q bandpass filtering and relaxes the linearity requirement on LNTA. Moreover, the passive/active implementation of the loop filter gives a good trade-off between power consumption, linearity and dynamic range. A design example with 10 MHz useful bandwidth and 0.4-4.0 GHz frequency range is conducted to demonstrate the feasibility and the characteristics of this proposed architecture.
A prototype system for acoustic emission-based structural health monitoring of My Thuan bridge

The paper describes the stages in the development of the prototype monitoring system commissioned by the government of Vietnam (the Socialist Republic of Vietnam) for the structural health evaluation of the My Thuan cable-stayed bridge over the Tien Giang River in the Mekong Delta. The system is based on the acoustic emission (AE) technology, which uses the destructive process identification method (RPD). The application of AE technique allows monitoring and tracking the processes that occur over the entire volume of a structure independent of strain and stress but depending mainly on the integrity of the structure, which is of utmost importance for the service life and safe operation of the bridge.
An adaptive DC-DC converter for loading circuit of Li-Ion battery charger

In this paper, an adaptive output DC-DC converter designed for lithium-ion (Li-Ion) battery charger circuit is proposed. The converter operates in continuous conduction mode (CCM) to provide an output voltage in response to battery voltage and a wide-range output current to ensure that circuit requirements are met. This circuit is designed on Cadence using 0.35μm BCD technology. Simulation results show that the circuit fully operates in CCM mode with a load current from 50 mA to 1000 mA and output voltage ripple factor is less than 1%. Furthermore, the current supplied to the load circuit responses to three types of Li-Ion rechargeable currents. The output voltage of the converter varies from 2.8 V to 4.5 V corresponding to the voltage range of the battery being charged from 2.5 V to 4.2 V. The average power output of the converter in large load current mode (1000 mA) reaches 92.3%.
A practical synchronization algorithm for IEEE 802.15.4a UWB receivers

This paper proposes a two-step synchronization algorithm for UWB receivers in accordance with IEEE 802.15.4a standard. A low data rate, low complexity receiver is developed using a typical energy detection UWB non-coherent analog front-end, which consists of a square-law device and an integrate-and-dump ADC with sub-Nyquist sampling rates. A coarse synchronization algorithm, often neglected in literature, is introduced by continuously correlating received samples' segments with a self-generated template until a simple threshold condition is satisfied. A proposed fine synchronization algorithm exploits the low sampling rates of the system and does not need to measure noise power, which helps reduce the receiver complexity (and power consumption). Finally, we assess, by simulation, the impact of different sampling rates and the synchronization lengths on bit-error-rate (BER) performance of the system.
CW Experiments With the EU 1-MW, 170-GHz Industrial Prototype Gyrotron for ITER at KIT

The European 1-MW, 170-GHz continuous wave industrial prototype gyrotron for electron cyclotron resonance heating and current drive on international thermonuclear experimental reactor was during 2016 under test at the Karlsruhe Institute of Technology (KIT) test facility. In order to optimize the gyrotron operation, the tube was at first thoroughly tested in the short-pulse regime, with pulses that did not exceed 10 ms, for a wide range of operational parameters. Then, and after proper conditioning of the tube, the operation was extended to longer pulses with duration up to 180 s, which is the maximum pulselength possible at the KIT test facility. In this paper, we present in detail the achievements of the long-pulse experimental campaign.
Center pixel weight estimation for non-local means filtering using local James-Stein estimator with bounded self-weights

Assigning appropriate center pixel weights (CPW) in nonlocal means (NLM) filter is an important issue to affect the quality of filtered images. Using local James-Stein (LJS) type CPW yielded superior peak signal-to-noise ratio (PSNR) over using other existing methods of determining the contribution of center pixels in NLM. However, the original LJS CPW method assumed no upper bound for self-weights implicitly, it may yield excessively large self-weights and visual artifacts. We propose a method, called bounded self-weights LJS (BLJS), to incorporate bounded self-weights into LJS such that this new estimator is dominating partially. Our proposed method was evaluated using a patient MR image with 3 levels of additive Gaussian noise. For fixed local area, the proposed BLJS yielded lower variances than the original LJS for almost all bias levels. BLJS also achieved PSNR comparable to or better than LJS. Visual image quality assessment showed that BLJS produced less localized visual artifacts than LJS.
Aligning Service Level Agreements with Service-Oriented Enterprise Architecture

High-level enterprise services are considered as wrappers of business processes and ICT capabilities in enterprise architecture. Enterprise services have distinctive features that are not typically observed in Web services, e.g. signicant portions of the functionality of these services might be executed in a human-mediated fashion. As such, a service level agreement should be described as a mixture of human-mediated functionality (e.g., service penalty) and computer-interpretable factors (e.g., reliability, payment). This paper reports our preliminary work in defining a taxonomy for co-relating SLAs with elements of enterprise architecture. It gives insight into the alignment between what the enterprise in questions contractually agrees with its partners (or customers) and what it possesses to be able to fulfill the agreement. We define the service level agreement formally. We adopt the ArchiMate – a widely used language for modeling and analyzing enterprise architectures. We then propose the corelation between items in the agreement with elements in the enterprise architecture. We showcase our work using a real-life case-study in the retailing market of domestic airfare.
A Simple Statistical Algorithm for Biological Sequence Compression

This paper introduces a novel algorithm for biological sequence compression that makes use of both statistical properties and repetition within sequences. A panel of experts is maintained to estimate the probability distribution of the next symbol in the sequence to be encoded. Expert probabilities are combined to obtain the final distribution. The resulting information sequence provides insight for further study of the biological sequence. Each symbol is then encoded by arithmetic coding. Experiments show that our algorithm outperforms existing compressors on typical DNA and protein sequence datasets while maintaining a practical running time
Analysis on semantic transactional memory footprint for hardware transactional memory

We analyze various characteristics of semantic transactional memory footprint (STMF) that consists of only the memory accesses the underlying hardware transactional memory (HTM) system has to manage for the correct execution of transactional programs. Our analysis shows that STMF can be significantly smaller than declarative transactional memory footprint (DTMF) that contains all memory accesses within transaction boundaries (i.e., only 8.3% of DTMF in the applications examined). This result encourages processor designers and software toolchain developers to explore new design points for low-cost HTM systems and intelligent software toolchains to find and leverage STMF efficiently. We identify seven code patterns that belong to DTMF, but not to STMF, and show that they take up 91.7% of all memory accesses in transactional boundaries, on average, for the transactional programs examined. A new instruction prefix is proposed to express STMF efficiently, and the existing compiler techniques are examined to check their applicability to deduce STMF from DTMF. Our trace analysis shows that using STMF significantly reduces the ratio of transactions overflowing a 32KB L1 cache, from 12.80% to 2.00%, and substantially lowers the false positive probability of Bloom filters used for transaction signature management, from 23.60% to less than 0.001%. The simulation result shows that the STAMP applications with the STMF expression run 40% faster on average than those with the DTMF expression.
Cognitive spectrum access in femtocell networks exploiting nearest interferer information

In this paper, we consider the sensing-based dynamic spectrum access problem for femtocells in the two-tier network. We propose to exploit the information of the nearest macrocell base stations (MBSs) activity (i.e., on or off activity on the target frequency band) so that each femtocell base station (FBS) can make its access decision differently depending on the activity of the nearest MBS and the detected interference plus noise energy level. We then develop an analytical model to evaluate the performance of the proposed sensing-based access scheme in terms of success probability and total throughput by employing the stochastic geometry technique. We also provide an efficient and low-complexity algorithm to determine the sensing time and access thresholds for throughput maximization. Numerical studies are then conducted to validate the analysis and demonstrate that our proposed spectrum access with the information of nearest MBS activity achieves better total throughput performance than other scheme with no sensing or sensing without nearest MBS activity information.
An X-band high-efficiency ion-implanted MMIC power amplifier

A state-of-the-art X-band high-efficiency MMIC power amplifier has been demonstrated. An average output power of 3.6 W at an average 41% power-added efficiency over a 40% bandwidth from 7.0 to 10.5 GHz has been achieved. An average power density of 500 mW/mm and peak power density of 550 mW/mm have been measured across this bandwidth. Peak efficiencies of 56% at 7 GHz and above 50% from 7.5 to 9 GHz were achieved when the drain was biased at 6 V.<<ETX>>
Anycast end-to-end resilience for cloud services over virtual optical networks

Optical networks are crucial to support increasingly demanding cloud services. Delivering the requested quality of service is key to successfully provisioning end-to-end services in clouds. Therefore, as for traditional optical network services, it is of utter importance to guarantee that clouds are resilient to any failure of either network infrastructure or data centers. A crucial concept in establishing cloud services is that of network virtualization: the physical infrastructure is logically partitioned in separate virtual networks. Also, combined control of the network and data center (IT) resources is exploited. To guarantee end-to-end resilience for cloud services in such a set-up, we need to simultaneously route the services and map the virtual network, while ensuring that an alternate routing is always available. Note that the anycast routing concept applies: assigning server resources requested by the customer to a particular (physical) data center can be done transparently. This paper investigates the design of scalable optimization models to perform the virtual network mapping resiliently (for single bidirectional link failures), thus supporting resilient anycast cloud virtual networks. We compare two resilience approaches: PIP-resilience maps each virtual link to two alternate physical routes, VNO-resilience provides alternate paths in the virtual topology (while enforcing physical link disjointness).
A parallelepiped multispectral image classifier using genetic algorithms

The parallelepiped classifier is one of the widely used supervised classification algorithms for multispectral images. The threshold of each spectral (class) signature is defined in the training data, which is to determine whether a given pixel within the class or not. To avoid involving the analyst for the training data selection, this paper is to study whether the threshold of parallelepiped classifier can be automatically determined by using natural evolution process - genetic algorithms (GAs). In other words, our goal is to create an unsupervised multispectral parallelepiped classifier with the help of genetic algorithms. In this algorithm, we also use a new approach to estimate the initial range. Preliminary experimental results with different parameters for genetic algorithms and a comparison with the supervised parallelepiped classifier are provided.
A complexity measurement for de novo protein folding

Predicting how a protein folds based solely on its amino acid sequence is an ongoing challenge for the fields of Bioinformatics and Computer Science. Previous attempts to solve this problem have relied on algorithms and a specific set of benchmark proteins. However, there is currently no method for determining if the set of benchmark proteins share a similar level of complexity with proteins of similar size. As a result, a larger variety of benchmarks might be needed to evade this problem and a measure of complexity established to determine the validity of all benchmarks. We propose here the Ouroboros Complexity Measurement for the de novo folding of proteins. This measurement is easy to compute (not an NP hard problem) and allows the comparing of protein complexity.
A study on cascade design for cpg-based controller of a planar snake robot

The maneuvering of a mobile robot is established based on two fundamental problems: the control of moving directions and the regulation of motion speeds. In the case of snake-like robots, solutions to these problems are hard to be intuitively derived because of the many degrees of freedom resulting from their hyper redundant structures. To overcome this issue, we divide the two fundamental problems into three subproblems which are the creation of snake robots crawling motion, steering this crawling motion, and regulating robots crawling speed, then tackle them in a cascade manner. The foundation of our controller is constructed out of the Central Pattern Generators (CPGs) — a mathematical model of animals nervous system. The significance of our method is that we propose a virtual system which can abstract snake-like robots as a differential-drive wheeled vehicle.
A double regulated footer and header voltage technique for ultra-low power IoT SRAM

This work presents an ultra low power SRAM circuit which is suitable for tight power budget of IoT microcontrollers. The leakage power reduction technique using double regulated footer and header voltage in order to meet the requirements for retaining data SRAM in IoT applications. In normal SRAM operation, header and footer voltage are regulated full rail voltage by VDD and VSS, respectively. In idle mode, SRAM cell supply voltage should be lowered as much as possible to reduce more leakage current but still keep data without loss. Body effect is more efficient by lowering supply voltage on double header and footer than just only header or footer at same noise margin. By doing so, the author compares three techniques of the single regulated footer voltage (SRFV), single regulated header voltage (SRHV) and double regulated footer and header voltage (DRFHV) to make conclusion in term of power saving. In the fair comparison in active mode, author realizes that double regulated footer and header voltage technique is more efficiency power saving than three other techniques in retention mode.
Acceleration of a Suborbital Payload Using an Electromagnetic Railgun

Railguns are well-known for their capability to reach very high velocities (v0> 2000 m/s) with overall efficiencies (Ekinetic/Eelectric) over 30%. The high performance expected concerning velocity, efficiency, cost, and repetition rates makes this system attractive not only for military but also for space applications with the aim of accelerating lightweight payloads directly into the low earth orbit (500 km). This last application is very challenging, as far as the energy and power storage, the railgun length, and the rail materials are concerned, but seems promising. In a first step towards space launch, ISL and EADS have investigated, within the scope of two ESA financed studies, the possibility of using a railgun to replace a sounding rocket with the aim of accelerating a meteorological probe up to an apogee of 120 km. In this paper, a quantitative assessment of the concept of the railgun, coupled to the object to be accelerated, is proposed. The electric circuit necessary to drive the facility is given: electric energy sources, switches, pulse forming network as well as a first layout of the railgun itself (length, caliber, materials), and of its current injection points. A series of preliminary test shots of dummy projectiles with masses ranging from 1 to 4 kg using the existing PEGASUS railgun facility at ISL is reported. The projectiles were launched reliably and in a reproducible way with accelerations not exceeding 13000 g, except for one shot with the 2-kg projectile fired with an acceleration of 15700 g, thus, reproducing the suborbital launch conditions. A first estimation of how to delay the plasma occurrence of the sliding armatures used for the suborbital applications at low accelerations is also given in this paper
Comparative analysis of pick & place strategies for a multi-robot application

This paper deals with a comparative analysis of different pick & place strategies. The purpose is to give some rules to obtain a good sizing in terms of components (number of robots, conveyor speed) and control laws (individual scheduling rules of each robot, collaborative strategy of all the robots) of a multi-robot cell. This approach is validated by the use of a new simulation tool combining a behavioral simulation of multiple robots and the product flows. This simulation tool takes into account not only the end effector, but also the robots collaborative aspect to ensure the desired overall performance for a given task.
A proposed RISC instruction set architecture for the MAC unit of 32-bit VLIW DSP processor core

Multiplier-accumulator is a specific hardware unit that performs a common operation - computing the product of two numbers and adding that product to an accumulator. Especially, in digital signal processing applications which consist of a large number of convolution operations, the emergence of MAC unit contributes greatly to the high performance of the systems. This work is about an implementation for a specific MAC unit based on the proposed RISC instruction set architecture (ISA) of 32-bit VLIW Fixed-point DSP processor core presented in our previous work. The computational unit is designed to be flexible for 32-bit/16-bit/8-bit data computations. The implementation is verified to function correctly not only in Modelsim software but also on Altera Cyclone II (2C35) FPGA board.