nils-herrmann/clean_scirepeval huggingface dataset:
Fully Adaptive Multiband Bandstop Filtering Sections and Their Application to Multifunctional Components
Venue: IEEE Transactions on Microwave Theory and Techniques

An original RF design approach for the realization of fully reconfigurable planar multiband bandstop filters (BSFs) is reported. The engineered RF filtering topology allows independent control of its stopbands in terms of center frequency and bandwidth. It exploits the in series cascade of K spectrally agile N notch filtering cells that are connected through K 1 static impedance inverters to realize an N band filtering transfer function with Kth order stopbands. Each of these multinotch cells is formed by N tunable resonators center frequency control that interact with the same nonresonating node by means of different variable couplings bandwidth control. Additional features of this tune all multiband BSF architecture when compared with related prior art devices are: 1) scalability to the synthesis of an arbitrary number of stopbands; 2) notch spectral merging capability into wider eliminated bands of the same order, which equivalently allows the intrinsic control, i.e. without RF switches, of the amount of active rejected bands; and 3) smaller physical size. The coupling matrix modeling of the conceived multiband BSF scheme is presented. Moreover, its cointegration with other RF analog processing actions in multifunctional components, such as bandpass filtering and power division, is investigated. For experimental validation purposes, three UHF band mechanically reconfigurable microstrip prototypes are developed and tested. They correspond to a dual notch filter, a wideband bandpass filter with embedded notches in its tunable passband, and a Wilkinson type power divider with inserted stopbands for dynamic multi interference mitigation.
Periodic nonlinear Fourier transform for fiber optic communications, Part I: theory and numerical methods.
Venue: Optics express

In this work, we introduce the periodic nonlinear Fourier transform (PNFT) method as an alternative and efficacious tool for compensation of the nonlinear transmission effects in optical fiber links. In the Part I, we introduce the algorithmic platform of the technique, describing in details the direct and inverse PNFT operations, also known as the inverse scattering transform for periodic (in time variable) nonlinear Schrodinger equation (NLSE) We pay a special attention to explaining the potential advantages of the PNFT based processing over the previously studied nonlinear Fourier transform (NFT) based methods. Further, we elucidate the issue of the numerical PNFT computation: we compare the performance of four known numerical methods applicable for the calculation of nonlinear spectral data (the direct PNFT) in particular, taking the main spectrum (utilized further in Part II for the modulation and transmission) associated with some simple example waveforms as the quality indicator for each method. We show that the Ablowitz Ladik discretization approach for the direct PNFT provides the best performance in terms of the accuracy and computational time consumption.
Second Order Statistics of the Scattering Vector Defining the D T Nonlinear Fourier Transform

The impact of time domain noise on the nonlinear Fourier transform is currently not well understood. Most, if not all, available results are based on perturbation theory and become exact only in the low noise regime. In this paper, it is pointed out that the mean and the (conventional and complementary) covariance of the scattering vector a(z) b(z) that is used to define the discrete time nonlinear Fourier transform can be computed exactly if a known deterministic signal is contaminated with circular symmetric white noise. Since the scattering vector is a polynomial in z, also the second order statistics of its coefficient vector are derived. This result is finally used to determine the second order statistics of an arbitrary multipoint scattering vector, in which the values of the scattering vector for several arguments are stacked. The results are illustrated in a numerical example, and potential extensions are discussed. NOTATION Bold face Matrix or vector Underbar Random quantity Id Identity matrix of size dx d 0d Zero matrix of size dx d I Identity matrix of appropriate dimensions 0 Zero matrix of appropriate dimensions d[n] Discrete Dirac delta E{ Expectation Complex conjugate Transpose Conjugate transpose R*,I* Real and imaginary part j Imaginary number
On the robust model predictive control method of dynamic positioning to line for UUV recovery
Venue: OCEANS 2016 MTS/IEEE Monterey

Unmanned underwater vehicle (UUV) has been applied for civil field all over the world. In technologies of UUV, the underwater recovery technology plays an essential part. And the superior precision control system is necessary for UUV underwater recovery. In this paper, the research background is the mother ship carries UUV recycling in piggyback method. And the important point is the method of dynamic positioning to line in process of UUV recovery and the UUV dynamic positioning to line strategy based on the robust model predictive control algorithm is proposed. Then, a digital simulation is made to verify the feasibility of the control algorithm. Through the simulation results, the conclusion of control algorithm is got.
A Novel Terminal Sliding Mode Control for the Navigation of An Under actuated UUV

In this paper$we present a self developed under actuated Unmanned Underwater Vehicle (Hereinafter abbreviated as UUV) After analyzing the motion and actuating characteristics of the UUV, the maneuvering motion models are established in the horizontal plane and vertical plane separately. Considering the model parameter uncertainties and unknown environmental disturbances, the course and depth automatic operating controllers of UUV are designed respectively on the basis of the sliding mode variable structure control algorithm to overcome these problems. The stability of the presented control laws is proved in the sense of the Lyapunov stability theory. Simulations performed on the under actuated UUV demonstrate the effectiveness of the proposed method.
Adaptive neuro fuzzy tracking control of UUV using sliding mode control theory based online learning algorithm
Venue: 2016 12th World Congress on Intelligent Control and Automation (WCICA)

This paper presents the control of an Unmanned Underwater Vehicle(UUV) with five degrees of freedom by using an adaptive neuro fuzzy controller combined with a sliding mode control (SMC) theory based learning algorithm. The proposed control structure is composed of an adaptive fuzzy neural network(AFNN) and a conventional PD controller which is used to guarantee the asymptotic stability of the system in a compact space. The parameter updating rules of the neuro fuzzy system using SMC theory are derived, and the stability of the learning is proven using a Lyapunov function. The simulation results show that the control scheme with the proposed SMC theory based learning algorithm is able to not only decrease the steady state error but also improve the transient response performance of the UUV.
Docking technique for manta type UUV and its experimental studies in water tank environment
Venue: OCEANS 2016 MTS/IEEE Monterey

We present an underwater docking technique for a manta type unmanned undersea vehicle (UUV) which is under development in Korea Institute of Robot and Convergence (KIRO) The manta type UUV is a test bed vehicle for demonstrating an autonomous docking technique in the water tank  There are two cameras mounted in front of the vehicle for vision based underwater localization around docking station. There is a range sonar array mounted in front of the vehicle. This sonar is used for obstacle avoidance, and also can be used as a simultaneous localization and mapping (SLAM) solution in a partially known environment. In this paper, we show the results of a remote docking experimentation performed in the water tank for the manta type UUV. From the results, we verify the docking performance of a manta type UUV and applicability of the developed docking station.
UUV dynamic path planning and trap escape strategies in unknown environment
Venue: 2016 35th Chinese Control Conference (CCC)

A new planner based on sonar detection data is developed in this paper for the dynamic path planning of UUV in a global uncertain environment with concave traps. By analyzing sonar data, we divide the sensing area into a number of free sectors and block sectors; UUV tends to the target point through a optimal free sector. One virtual barrier called "entrance lock" was designed to assists the UUV to escape from traps, "entrance lock" is always be generated at the entrance of the trap, so it can also prevents the UUV from entering the concave trap that has been detected. The simulation shows that this method can solve the problem of long time wandering in the large concave trap, which exists in the traditional methods and even if the narrow feasible path is not ignored. The time consuming of the dynamic planning is just a little and can well meet the real time requirements in complex unknown dynamic environment.
Soft landing guidance law for UUV bottom sitting task
Venue: 2016 35th Chinese Control Conference (CCC)

In order to achieve a smooth and non overshoot performance for risk of striking the seabed in UUV bottom sitting task, a soft landing guidance law is presented, which is inspired from the corresponding concept in aerospace science. The guidance law is a polynomial function with respect to time, and the desired vertical position, velocity and acceleration of UUV are determined. In particular, the necessary and sufficient condition for rationality of the guidance law is explained and proved. Theoretical analysis indicates that, with this method, the energy consumption of UUV only depends on the initial velocity and the final velocity, and thus a trade off between time consumption and energy consumption could be achieved when setting desired velocities. Simulation results show that the UUV moves towards the destination at the determined velocity and acceleration by the proposed guidance law without overshoot, and the acceleration approaches zero according with the concept of soft landing. Safety, rationality, and effectiveness of the proposed guidance law are demonstrated.
Path Planning for UUV in Dynamic Environment
Venue: 2016 9th International Symposium on Computational Intelligence and Design (ISCID)

From naval operations to ocean science missions, the importance of autonomous vehicles is increasing with the advances in underwater robotics technology. Due to the dynamic and intermittent underwater environment and physical limitations of underwater unmanned vehicle (UUV) feasible and optimal path planning is crucial for autonomous underwater operations. According to different mission, the path planning method of UUV is divided into two categories: the point to point path planning and the complete coverage path planning. The objective of this thesis is to develop and demonstrate an efficient underwater path planning method that is adapted to complicated ocean environment. In this thesis, existing path planning method for the fields of ocean science and robotics are first reviewed, and then local dynamic obstacle avoidance method is proposed to avoid dynamic obstacles. Based on this again, the path planning of UUV in local dynamic environment can be efficiently implemented by adopting rolling window path planning method and local dynamic obstacle avoidance method. This method with the guide point strategy combines global path planning with local dynamic path planning, so that not only the requirements of real time on line path planning for UUV are met, the global optimality is also considered. A navigation route for UUV is planned in advance by using priori environmental information based on ant colony algorithm, so it provides the reference information for the selection of guide point. In order to solved the problem of area coverage search, a complete coverage path planning method is proposed by combining ant colony algorithm with biologically inspires neural network. In order to demonstrate underwater path planning method, all of the above ideas and methods developed were tested in simulation experiments.
UUV dynamic path planning and trap escape strategies in unknown environment
Venue: CCC 2016

A new planner based on sonar detection data is developed in this paper for the dynamic path planning of UUV in a global uncertain environment with concave traps. By analyzing sonar data, we divide the sensing area into a number of free sectors and block sectors; UUV tends to the target point through a optimal free sector. One virtual barrier called "entrance lock" was designed to assists the UUV to escape from traps, "entrance lock" is always be generated at the entrance of the trap, so it can also prevents the UUV from entering the concave trap that has been detected. The simulation shows that this method can solve the problem of long time wandering in the large concave trap, which exists in the traditional methods and even if the narrow feasible path is not ignored. The time consuming of the dynamic planning is just a little and can well meet the real time requirements in complex unknown dynamic environment.
Hydrodynamic characteristics and stability simulation of four rotor dish shaped UUV landing on the seabed
Venue: OCEANS 2016 MTS/IEEE Monterey

Four rotor dish shaped UUV is a new type of equipment for aquaculture to survey water pollution, which can land on the seabed by extending the hydraulic support. In this paper, the instability state of the UUV is defined, and the mathematical model of the instability state is established. Unstructured mesh generation is carried out using Ansys ICEM. Considering the coupling of the UUV between flow field and seabed, the numerical simulation calculation is completed by using Ansys CFX. 4 different flow velocities, 4 different distance and 4 different attack angles are calculated, and the curve of the fluid force and torque for the UUV landing platform is drawn. Finally, the relationship between the stability of UUV and the variables is analyzed and summarized. Application of this landing method and the results can be used for practical design and experiment purposes for the new UUV platform.
Near real time improved UUV positioning through channel estimation the Unscented Kalman Filter approach
Venue: OCEANS 2016 MTS/IEEE Monterey

The primary objective of this work is to enhance the navigational and positioning accuracy of Unmanned Underwater Vehicles (UUVs) by networking a number of Unmanned Surface Vehicles (USVs) utilizing underwater acoustic modems and acoustic travel time calculations. In a previous work  a tracking algorithm based on the Extended Kalman Filter (EKF) was developed presenting satisfactory results, but the assumption of the errors being Gaussian and zero mean at the base of the EKF is violated by the presence of nonlinearities in the measurement equation. In this work, a more suitable approach based on the Unscented Kalman Filter (UKF) is presented and its results compared to the existing approach. A combination of the EKF/UKF with a Smoothing Algorithm was developed and extensively tested with synthetic data. To validate the concepts, the tracking algorithms (EKF and UKF based) were applied to data collected during sea tests that took place in Monterey Bay in August, 2015.
Technology selection for infectious medical waste treatment using the analytic hierarchy process
Venue: Journal of the Air Waste Management Association

The overall objective of this paper was to evaluate five different technologies used for infectious medical waste treatment and select the optimum one by means of multicriteria analysis. Steam disinfection was selected as the optimum treatment technology, among others using incineration, microwave disinfection, chemical disinfection with sodium hypochlorite, and reverse polymerization with microwaves. The evaluation was based on four groups of criteria, specifically, environmental, economic, technical, and social criteria, using the analytic hierarchy process. Selection among four commercial systems using steam disinfection was not possible, because it required additional site specific criteria, e.g. loading capacity and requirements of local regulations.  The paper can help health care facilities to select the system for infectious waste treatment that best fits their needs. It was concluded that steam disinfection was the optimum technology, using environmental, economic, technical, and social criteria.
Limiting similarity and Darwin's naturalization hypothesis: understanding the drivers of biotic resistance against invasive plant species
Venue: Oecologia

Several hypotheses have been proposed to explain biotic resistance of a recipient plant community based on reduced niche opportunities for invasive alien plant species. The limiting similarity hypothesis predicts that invasive species are less likely to establish in communities of species holding similar functional traits. Likewise, Darwin's naturalization hypothesis states that invasive species closely related to the native community would be less successful. We tested both using the invasive alien Ambrosia artemisiifolia L. and Solidago gigantea Aiton, and grassland species used for ecological restoration in central Europe. We classified all plant species into groups based on functional traits obtained from trait databases and calculated the phylogenetic distance among them. In a greenhouse experiment, we submitted the two invasive species at two propagule pressures to competition with communities of ten native species from the same functional group. In another experiment, they were submitted to pairwise competition with native species selected from each functional group. At the community level, highest suppression for both invasive species was observed at low propagule pressure and not explained by similarity in functional traits. Moreover, suppression decreased asymptotically with increasing phylogenetic distance to species of the native community. When submitted to pairwise competition, suppression for both invasive species was also better explained by phylogenetic distance. Overall, our results support Darwin's naturalization hypothesis but not the limiting similarity hypothesis based on the selected traits. Biotic resistance of native communities against invasive species at an early stage of establishment is enhanced by competitive traits and phylogenetic relatedness.
Greed, grievance, leadership and external interventions in the initiation and intensification of the civil war in Angola

Understanding the initiation of conflict is fundamental for the success of efforts in conflict prevention. The validity of the mechanisms of the "Greed and Grievance" model, alongside leadership and external interventions are tested in four periods of initiation and intensification of the conflict in Angola. All mechanisms are present but their relative relevance varies throughout the conflict. Among the mechanisms identified in each period the most relevant in the Cold War period are the international and regional interventions in 1961 and 1975 and in the post Cold War period, the "greed" factors in 1992 (oil and diamonds, poverty and war capital) and the UNITA leadership of Jonas Savimbi in 1998. The case study provides evidence that "greed" and "grievance" can be interlinked (such as in 1992) and confirms the relevance of leadership and external interventions mechanisms.
CD MOF: A Versatile Separation Medium.
Venue: Journal of the American Chemical Society

Porous metal organic frameworks (MOFs) have been studied in the context of a wide variety of applications, particularly in relation to molecular storage and separation sciences. Recently, we reported a green, renewable framework material composed of g cyclodextrin (g CD) and alkali metal salts namely, CD MOF. This porous material has been shown to facilitate the separation of mixtures of alkylaromatic compounds, including the BTEX mixture (benzene, toluene, ethylbenzene, and the regioisomers of xylene) into their pure components, in both the liquid and gas phases, in an energy efficient manner which could have implications for the petrochemical industry. Here, we report the ability of CD MOF to separate a wide variety of mixtures, including ethylbenzene from styrene, haloaromatics, terpinenes, pinenes and other chiral compounds. CD MOF retains saturated compounds to a greater extent than their unsaturated analogues. Also, the location of a double bond within a molecule influences its retention within the extended framework, as revealed in the case of the structural isomers of pinene and terpinine, where the isomers with exocyclic double bonds are more highly retained than those with endocyclic double bonds. The ability of CD MOF to separate various mono and disubstituted haloaromatic compounds appears to be controlled by both the size of the halogen substituents and the strength of the noncovalent bonding interactions between the analyte and the framework, an observation which has been confirmed by molecular simulations. Since CD MOF is a homochiral framework, it is also able to resolve the enantiomers of chiral analytes, including those of limonene and 1 phenylethanol. These findings could lead to cheaper and easier to prepare stationary phases for HPLC separations when compared with other chiral stationary phases, such as CD bonded silica particles.
Encapsulation of curcumin in cyclodextrin metal organic frameworks: Dissociation of loaded CD MOFs enhances stability of curcumin.
Venue: Food chemistry

Curcumin has been successfully encapsulated in cyclodextrin metal organic frameworks (CD MOFs) without altering their crystallinity. The interaction between curcumin and CD MOFs is strong through hydrogen bond type interaction between the OH group of cyclodextrin of CD MOFs and the phenolic hydroxyl group of the curcumin. Interestingly, dissolving the curcumin loaded CD MOFs crystals in water results in formation of a unique complex between curcumin, gCD and potassium cations. In fact, the initial interaction between curcumin and CD MOF is crucial for the formation of the latter. This new complex formed in alkaline media at pH 11.5 has maximum absorbance at 520nm and emittance at 600nm. Most importantly, the stability of curcumin in this complex was enhanced by at least 3 orders of magnitude compared to free curcumin and curcumin:g CD at pH 11.5. These results suggest a promising benign system of CD MOFs, which can be used to store and stabilize curcumin for food applications.