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Students of European integration have produced an enormous amount of literature on the intergovernmental negotiations that led to the establishment of such organizations as the OEEC, the EEC and EFTA. However, only a few have devoted substantial attention to the international contacts between companies that attempted to undermine the integration process by building private trade barriers that would replace those that governments had agreed to remove. The paper producers began to build such barriers soon after EFTA and the EEC had been set up. Although these attempts were not always successful, the industrialists did manage to create arrangements that were substantially more extensive in their geographical and product scope than those that had existed before. The British government and the EEC were reluctant to challenge these arrangements, and in some cases even actively promoted them. The interwar decades are widely considered to be the ‘golden era’ for international cartels; but for the paper cartels, the ‘golden era’ began in the 1960s, when previous bilateral links were replaced with multilateral ones. [ABSTRACT FROM PUBLISHER]

Based on data analysis and documentary research, this paper indicates that the main causes which negatively affect the preservation of paper documents in China are acidification and damaging pests such as moths and insects. The priorities for the preservation of Chinese documents are protecting the documents against air pollution and controlling pests and insects. Taking these problems and the Chinese national condition into account, the paper proposes to create a favorable microenvironment for decreasing the acidification of papers and to adopt various measures for controlling pests and insects. [ABSTRACT FROM AUTHOR]

Leveraging Rubik Tables, the authors designed a constant-factor optimal algorithm for stack rearrangement and multi-robot motion planning problems under extreme robot density. A general algorithm and several specialized algorithms are then introduced to solve the problem, constructing a product between the event model and a specification automaton. Toward that, the authors analyze closed-loop dynamics to identify conditions that lead to deadlock and, using duality theory and KKT conditions, derive geometric properties of robot configurations in deadlock. [Extracted from the article]

This special issue is organized by selected papers presented at International Symposium on Robotics Research (ISRR 2019), held on October 6-10, 2019, at Hanoi, Vietnam. The guest editors would like to express their sincere gratitude to the authors for their patience by the review process that was slowed down due to the difficulties caused by the worldwide pandemic and are very delighted this special issue is finally complete. The robotics fundamental contributions are about algorithmic foundation for manipulation and innovative robotics design and two papers are included for each topic. [Extracted from the article]

In scholarly debates, Ludwik Fleck's post-war paper 'Problemy naukoznawstwa [Problems of the Science of Science]', published in 1946, has been taken unanimously to illustrate the epistemology expounded in his monograph Genesis and Development of a Scientific Fact. The paper has also been seen to support parts of the received view of Fleck, notably that he manufactured an anti-typhus vaccine while imprisoned in Buchenwald. However, a different narrative emerges when comparing Fleck's paper with other accounts, also published in 1946 and written by other prisoners alluded to by Fleck in his paper. The situation is further complicated by four papers, published in prestigious scientific journals between 1942 and 1945, by the German medical leader of the typhus studies accounted for by Fleck. In addition, a thus-far neglected paper by Fleck, published in 1946 and summarizing his observations on typhus, discloses his role in the Buchenwald studies. Despite the obvious difficulties with tracing the history behind these works, notably the one on Nazi science, the contention is that what was attempted in Buchenwald in the name of science amounted to pseudoscience. This conclusion is amply supported not only by the accounts given by Fleck's fellow prisoners, but also by his own post-war paper on typhus. Based on the above findings, it is suggested that the mythology about Fleck, established in the 1980s, has been accomplished by a selective reading of his papers and also that the role played by Fleck was more complex than has so far been contemplated. [ABSTRACT FROM AUTHOR]

The vibration analysis of large and complex structures such as ships is difficult, because a vibrating ship hull (or its components) exhibits quite different vibration characteristics. Technological developments offer new concepts, definitions and comprehensive studies in the ship vibration field. The aim of this paper (bibliography) is to list references to papers, conferences, and proceedings dealing with ship vibrations that were published between January 2000 and April 2003. It contains 64 bibliographic references. The following types of ship vibrations are included: sea conditions, structural analysis, machine components, ship propulsive system, ship machines and special studies. Moreover, basic and brief information (reference, publication type, simulation models, utilizing methods and/or models, examined subject and/or problem) about grouped references has been given in the tables. So, this review paper not only lists references to papers at the millennium, but also helps researchers in their studies on ship vibration to find the necessary references quickly and practically. [ABSTRACT FROM AUTHOR]

The article presents comments concerning Eva Hedfors' paper on Ludwik Fleck. It argues that Hedfors proposes an informed reading of Fleck which aims to contest the mythology of the latter. It explores the claim of Hedfors that the work of Fleck is poorly done, meaningless and of doubtful ethical value. It emphasizes that the views of Fleck on science is aimed at legitimating his own scientifically weak research. It examines the preface made by Hedfors to her thesis wherein she elaborates that when she first read Fleck, she found an interest in his writings.

The article focuses on the Science and Technology Studies (STS) community's view toward politics which is offered by philosopher Gerard de Vries. The author states that de Vries' general critique against most of science studies is that people are so busy renewing some feature of scientific practice that people took off the shelf whatever political theory they had. The author explains that science studies has made people realize that politics has always been issue-oriented. It notes that the paper of de Vries reminds that people have been good at tracing the constant innovations of science and technology but have been lazy in expecting that all those new matters will find a place inside the vast dome of already assembled democratic politics.

Responds to comments made on the paper 'Foam Plastic Thermal Insulation in Low-Sloped Roofing Systems,' which appeared in the April 2002 issue of the 'Journal of Thermal Envelope & Building Science.' Phenolic foam insulation; Concentration of corrosion on the steel deck underneath insulation board joints; Vapor diffusion modelling; Acid barriers.

The fracture phenomenon of fastener clips occurs frequently in the sections with serious rail corrugation of high-speed railway, which brings huge potential safety hazards to track service and driving safety. In order to prevent the vibration fatigue fracture of fastener clips in high-speed railway, a dynamic vibration absorber (DVA) for clips is proposed in this paper to suppress the primary sensitive frequency of the corresponding resonant of clips. Firstly, based on the optimal design theory of DVA, a parameters design method of ring-shaped DVA suitable for clips is proposed. Secondly, the vibration characteristics of the high-speed railway fastener system are investigated, and the main reason for the fastener clips fracture is analyzed by simulation analysis combined with filed test. Then, focusing on the primary resonant frequency of clips, the vibration reduction effect of the ring-shaped DVA is analyzed. The results show that the ring-shaped DVA can change the natural frequency of the clip system, reduce the vibration response in the range of the original resonant frequency, and avoid the resonance phenomenon. Finally, the influences of mass ratio, frequency ratio, and damping ratio on the vibration reduction effect are analyzed, and the effectiveness of the parameters design method of ring-shaped DVA proposed in this paper is further proved. The research results can provide methodological support for the anti-breakage design of high-speed railway fastener clips. [ABSTRACT FROM AUTHOR]

Calls for papers for several conferences on engineering design and management in 2001.

Presents information for authors contributing papers to engineering conferences from July 2001 to May 2003.

Presents information for authors contributing papers to engineering conferences as of June 2001.

Presents a call for papers on topics related to structural mechanics. Boundary element technology; Computer-aided optimum design of structures; Marine technology.

Calls for the submission of research papers on several congresses about mechanics and applied mechanics which will be held on January 2001 to May 2003.

A set of 316 commentaries by authors of highly-cited papers was reviewed, to identify any difficulty encountered by the authors in producing or publishing their articles. The commentaries were selected from those published each week in the Citation Classic[SUPR] feature of Current Contents. According to their commentaries, a small proportion (5.7%) of the authors of these papers had some difficulty when doing the research, or when trying to publish the results. Three more highly-cited papers which had also encountered difficulties in getting published were identified from Citation Classic[SUPR] commentaries: one of them was co-authored by a Nobel Prize winner. Three of the papers which encountered publication problems are the most cited from their respective journals. In part, the problematic papers reported innovative methods or theories, or presented new interpretations of previous data. Those in the peer review system should have access to these findings, to improve their review of innovative work. Evaluative criteria that are too narrow can sometimes lead to the initial rejection of very important papers. [ABSTRACT FROM AUTHOR]

The article focuses on sociologist Sergio Sismondo's paper on constructivism. Sismondo's paper puts into focus disagreements and differences in understanding between those who have been associated with constructivism and those who are not. In defining ontology as part of historical experience, constructivism makes a characteristic shift, it takes a philosophical question or concept and reconstructs it within the domain of empirical analysis and theory. Constructivism owns many questions to philosophy, a fact picked up very well in Sismomdo's paper. What is often less understood is that, for constructivist studies, what is important and what is not just the question, it is the shift. In other words, these studies display mentality towards philosophical concepts, and it is where they run to and how they reformulated the issue that account for their own interest. Sismondo misconstrues the thesis that the world is a consequence, rather than merely a precondition, of scientific accounts. This is the sense in which he makes it appear as if the material world were an automatic consequence of scientific knowledge.

Classical analyses of differences among the sciences has measured social but not cognitive structure. This paper suggests a method for describing differences among fields in the processes of knowledge growth. The method examines closely what is said about a particular scientific paper when it is cited in later works, and traces changes over time, if they occur. A comparative analysis of cases drawn from neuropharmacology and the sociology of science is used to illustrate the approach. The two papers analyzed shown strong differences in the level of generality at which the contents of the original papers are cited. Lack of change over time in how the sociology of science paper is cited is attributed to the lack of attention to its main empirical knowledge claim. [ABSTRACT FROM AUTHOR]

Transparent objects are encountered frequently in our daily lives, yet recognizing them poses challenges for conventional vision sensors due to their unique material properties, not being well perceived from RGB or depth cameras. Overcoming this limitation, thermal infrared cameras have emerged as a solution, offering improved visibility and shape information for transparent objects. In this paper, we present TRansPose, the first large-scale multispectral dataset that combines stereo RGB-D, thermal infrared (TIR) images, and object poses to promote transparent object research. The dataset includes 99 transparent objects, encompassing 43 household items, 27 recyclable trashes, 29 chemical laboratory equivalents, and 12 non-transparent objects. It comprises a vast collection of 333,819 images and 4,000,056 annotations, providing instance-level segmentation masks, ground-truth poses, and completed depth information. The data was acquired using an FLIR A65 thermal infrared camera, two Intel RealSense L515 RGB-D cameras, and a Franka Emika Panda robot manipulator. Spanning 87 sequences, TRansPose covers various challenging real-life scenarios, including objects filled with water, diverse lighting conditions, heavy clutter, non-transparent or translucent containers, objects in plastic bags, and multi-stacked objects. Supplementary material can be accessed from the following link: https://sites.google.com/view/transpose-dataset. [ABSTRACT FROM AUTHOR]

In this paper, a new dynamic photogrammetry method using an unmanned aerial vehicle (UAV) is proposed and the UAV-based operational modal analysis method is established. The presented dynamic photogrammetry method can measure the dynamic displacements of structure using one or two cameras. However, it is difficult to use fixed cameras or handheld cameras to measure the dynamic responses for some outdoor structures, because it is hard to reach for measurement or maintenance sometimes. Therefore, UAV is an effective alternative and the homography-based perspective rectification method can be used to correct the UAV images. However, the presented methods use only four calibration points. Additionally, there is still obvious signal drift in the extracted dynamic responses. In this paper, a new time varying homography matrix, calculated using n calibration points, is proposed here for the first time to correct the perspective distortion for image at different time and the relative displacements are used to eliminate the influence of UAV in-plane motion. The influence analysis of UAV vibration and the method to eliminate the UAV vibration are the novelty of this paper. And then, the UAV-based operational modal analysis method is proposed. The proposed method is verified using a plane frame structure in laboratory. The results show that the proposed method can effectively eliminate the vibration of UAV and identify the structural modal parameters. Under the impulse excitation and white noise excitation, when the calibration points n is larger than 60, the relative errors of natural frequency and damping ratio are less than 0.4% and 5.45%, respectively. And the MAC values are all greater than 0.99. Meanwhile, the influence of the number of adopted calibration points on modal parameters identification is considered in the experiment and the advised value is given. [ABSTRACT FROM AUTHOR]

Kalman filter has emerged as a powerful tool for unbalance identification in rotating machinery. Recently, the augmented Kalman filter combined with the finite element model has grown up and projects its potential for complex rotor systems. This paper investigates the application of the augmented Kalman filter (AKF) to a practical turbofan engine. The current study reveals that using steady-state responses as measurements can cause fluctuation in the estimated results, even divergence for some cases, while the available signals in practice are steady-state responses generally. To the authors' knowledge, this practical problem is revealed for the first time. To address the problem, the convergence criterion is employed to improve the AKF and formulates the adaptive fading augmented Kalman filter (AFAKF) proposed in this paper. Results indicate that the increase of the amplification factor, the insufficient measurement points, and the complexity of the dynamic model can all lead to the deterioration of the estimated unbalance. The proposed AFAKF method shows favorable convergence and can achieve accurate estimation with less than 5% relative errors, and the superiority over AKF in computation cost is also observed. [ABSTRACT FROM AUTHOR]

The article presents a calendar of forthcoming congresses and conventions. The 13th International Congress on Sound and Vibration will be held on July 2-6, 2006 at Vienna University of Technology in Vienna, Austria. The 16th European Conference of Fracture will be held on July 3-7, 2006 in Alexandroupolis, Greece. The 8th Biennial ASME Conference on Engineering Systems Design and Analysis is scheduled on July 4-7, 2006 in Politecnico di Torino, Torino, Italy.

The article presents calendar of events related to mechanical engineering for 2006. The 19th International Congress & Exhibition on Condition Monitoring and Diagnostic Engineering Management will be on June 12 and 15. The 10th International Conference on Electrorheological Fluids and Magnetorheological Suspensions will take place in June 18 to 22. The 7th International Conference on Vibration Measurements by Laser Techniques-Advances and Applications & Short Course. The 13th International Congress on Sound and Vibration will be on July 2 to 6. The 16th European Conference on Fracture will be on July 3 to 7.

Since the transmission path of inter-shaft bearing-fault signal is complex, a fault feature extraction method based on hierarchical permutation entropy (HPE) and locally linear embedding (LLE) algorithm is proposed in this paper. In this method, HPE is utilized to extract fault information of signals, and LLE is utilized to reduce and fuse high-dimensional fault features of multi-sensors to construct fault samples. Then, the random forest (RF) model is established to diagnose the faults of the inter-shaft bearings. The fault simulation test rig with the inter-shaft bearing is built to simulate the normal bearing, inner ring fault, outer ring fault, and rolling ball fault, and the data are collected to verify the HPE-LLE-RF fault diagnosis algorithm of inter-shaft bearings established in this paper. The experimental results show that the proposed algorithm can extract the fault features of inter-shaft bearings effectively with a fault diagnosis accuracy of 93.3% without overfit phenomenon. [ABSTRACT FROM AUTHOR]

Environmental enrichment, besides having a great impact on animal welfare, can also be a potential variable in experimental research. Thus, we investigated whether enrichment of cages with paper tissues or plastic tunnels affects scientific outcome in the well-described mouse model of allergic asthma. BALB/cJ mice were introduced to paper tissues as nesting material, transparent plastic tunnels serving as shelters or kept in non-enriched cages. Afterwards, mice were sensitized to chicken egg ovalbumin (OVA) precipitated in aluminium sulphate and then intranasally challenged with OVA to induce allergic lung inflammation. Mice housed in cages enriched with paper tissues, but not with plastic tunnels, had increased total cell number, eosinophil number and IL-13 concentration in bronchoalveolar lavage fluid in comparison with the non-enriched control group. These results indicate that the effect of environmental enrichment on mice asthma models depends on the type of enrichment used. Therefore, it is important to consider the potential effects of any environmental enrichment on animal welfare and more importantly, on research results in order to standardize and obtain more accurate data from rodent studies. [ABSTRACT FROM AUTHOR]

This paper proposes a new disturbance observer concept based on the information of the estimated and measured signals for a micro-electro-mechanical system. First, the sliding-mode observer based on the linear matrix inequality was designed to estimate the states of a micro-electro-mechanical system gyroscope. Second, a new disturbance observer was proposed for estimating perturbations of the T-S fuzzy micro-electro-mechanical system gyroscope. Third, the double phase's fixedtime sliding-mode control was designed to control the positions and velocities of the MEMS system. The proposed disturbance observer input signals were taken into account from the measured and estimated signals. Two cases of high magnitudes and high frequencies disturbances were used to test the power of the proposed disturbance observer. Fourth, the Lyapunov condition was used to verify the corrections of the proposed controller and observer. Finally, the simulation by using MATLAB software was used to show the power of the proposed methods. The achievements of the small reachingtime, small tracking error, and stable steady-states under the vibration form outside of the system. [ABSTRACT FROM AUTHOR]

A comprehensive collection of papers citing the works of a leading theoretical molecular spectroscopist has been analyzed. Citations were collected in the period 1937-75, and classified by the following criteria: (a) cited in a 'cover-all' review; (b) cited among others; (c) cited extensively or as argumentation; (d) cited with some reservation; (e) cited with criticism; and (f) extensively used for further development. Results indicate a constant citation frequency within the entire period studied. It seems that the effect of the increase of publication output in this field is just about compensated for by the decay of the citation frequency. Citations of type a are uniformly spread over all papers, with an average of one citation every ten years. The ratio of types a + b to types c + d + e + f is not inconsistent with a value of about 1:2 - that is, citations to this author reflect considerable real impact. [ABSTRACT FROM AUTHOR]

Bearing is the most vulnerable key part in rotating machine and bears important influence on the safety of equipment. Weakness and complexity are the two features of fault characteristic information carried by signals in the early stage of fault. For that, a fault is difficult to be recognized correctly. To identify a compound failure of bearing, the paper has brought forward a new self-adaptive option method for component signals that are sensitive to failure feature information of bearing. The sensitivity of kurtosis to bearing failure is exploited and the influence of signal complexity on the extraction of failure feature information is taken seriously, the paper has proposed the self-adaptive option method for component signals that are sensitive to failure feature by combined kurtosis with Complexity parameter included in Hjorth parameters. Furthermore, as the mid-value represents the general level of signal and is not affected by larger or smaller data, with the mid-values of kurtosis and Complexity parameter as the boundary, the paper has chosen the component signals which can more comprehensively show the failure features of bearing. Additionally, by principal component analysis (PCA), component signals selected are blended and reconstructed. Finally, by the Hilbert envelope spectrum of signals reconstructed, failure types of bearing are identified. To verify the effectiveness of presented method, the presented method is compared with conventional method on the basis of the exactly consistent data. The result indicates that the proposed method is superior to the traditional one in extracting fault information and identifying the multiple failure types of bearing. [ABSTRACT FROM AUTHOR]

Honeycomb paperboard has been widely used in transportation and packaging of electronic instruments and furniture owing to the advantages of light weight, good compression resistance, environmental friendliness, and easy degradation. As a common cushioning material in transportation, it is worth studying the damping characteristic and vibration reduction mechanism of honeycomb paperboard. Based on the basic principles of vibration mechanics, the damping of honeycomb paperboard was proposed. Then the influences of cell length, paperboard thickness, grammage of core paper, and the honeycomb structures with face sheet or without face sheet on the damping characteristic of honeycomb paperboard were analyzed. Finally, the vibration reduction mechanism of packaging system with honeycomb paperboard and block was discussed briefly. The results show that the damping value of honeycomb paperboard decreases with the increase of cell length and paperboard thickness. The honeycomb paperboard with large grammage of core paper has high damping value, and yet paper honeycomb core structure without face sheet has poor damping capacity. What's more, the vibration reduction capacity of packaging system is influenced by the deformation and damping characteristic of honeycomb paperboard, among which material damping and structural damping contribute more, honeycomb deformation and air damping contribute less. The weight of block does not affect the damping characteristic of honeycomb paperboard, but affects the vibration reduction capacity of the whole system. [ABSTRACT FROM AUTHOR]

Citation counts are central to many studies in the sociology of science. Due to cost considerations and the format of the Science Citation Index, researchers often collect citations only to a scientist's first-authored publications (so called 'straight counts'), rather than to complete counts based on all published papers. This paper examines the consequences of using straight counts to study the careers of a sample of PhD biochemists. It is found that even though these two measures are highly correlated, there is a significant chance of making substantive errors when straight counts are substituted for complete counts. The problem is found to be more severe when citations are the dependent variable rather than an independent variable. It is argued that our findings can be generalized to other fields where multiple authorship is common. Accordingly, extreme care must be used in interpreting results based on straight citation counts. [ABSTRACT FROM AUTHOR]

Periodic structures are a type of metamaterial in which the physical properties depend not only on the details of the unit cell but also on how unit cells are arranged and interact with each other. In conventional engineering structures, each unit cell interacts with adjacent cells. Methods developed for vibrational and wave propagation analysis in periodic engineering structures consider only nearest-neighbor interactions. The dispersion curves of such systems, in which only adjacent cells interact, have been extensively studied. Metamaterial properties depend on the interactions of a unit cell with other cells. Further interactions, and specifically, interactions beyond the closest neighbors, imply a more complex band structure and wave behavior. In this paper, an example class of such structures, in which electrostatic forces are the driving force, has been investigated. In this paper, properties affecting these periodic structures, such as elastic forces, have been investigated. An attractive property of such structures is that the band structures of such metamaterials can be tuned by changing electric voltages. [ABSTRACT FROM AUTHOR]

Control effects of leading-edge grooves on deep cavity noise are investigated numerically. The length-to-depth ratio of the grooves are 0.5, 1, and 4, respectively. The freestream Mach number is equal to 0.16, corresponding to the Re based on the cavity length of 7.7 × 105. The Detached Eddy Simulations (DES) combined with Ffowcs Williams–Hawkings (FW-H) acoustic analogy are adopted to simulate the characteristic information of the flow field and the acoustic field. The analysis results show that all grooves investigated in this paper have a certain noise control effect, and the groove with the most obvious noise reduction effect is the groove with a length-to-depth ratio of 0.5, namely, the deep groove. Narrowband noise generated by the flow-acoustic feedback (100–700 Hz) and the acoustic resonance mechanism (above 300 Hz) and broadband noise caused by the turbulent disturbance in the shear layer of the cavity mouth significantly reduce when the deep groove is used for the noise control. The reason for the noise reduction is that the leading-edge grooves can effectively change the flow characteristics near the mouth of the downstream cavity. When the flow passes the grooves, the groove flow reduces the energy in the fluid, resulting in the significant decrease of flow velocity of the boundary layer of the incoming flow of the cavity. In addition, the use of the deep groove also promotes the vortex concentration position to move towards the bottom of the cavity, pushes the energy in the shear layer of the downstream cavity towards the front-edge as well as the bottom of the cavity, and stabilizes the development of the shear layer near the cavity mouth. [ABSTRACT FROM AUTHOR]

In the active magnetic bearing (AMB)-rotor system, a displacement sensor is one of the indispensable components. It detects the displacement of the rotor in real time and feeds back to the control system to realize the stable suspension of the rotor. However, due to electromagnetic interference, unstable power supply, poor grounding, and uneven rotor surface, the signal runout of the displacement sensor can often occur, resulting in rotor vibration. Given the above problems, this paper establishes the control model of the AMB-rotor system, lists three typical sensor runout signals, then analyzes the influence of different types of sensor runout on the system, and discusses the control methods under different sensor runout conditions. The research results have a specific guiding significance for vibration control of the maglev rotor under sensor runout influence. [ABSTRACT FROM AUTHOR]

Free vibration characteristics in uniform beams with several lumped attachments are an important problem in engineering applications that have to deal with mounting different equipment (e.g. motors, oscillators or engines) on a structural beam. In order to solve the lack of a generalized automatic procedure, this investigation presents a simple solving approach based on analytical means applied to a secular frequency equation for obtaining the natural frequencies of an arbitrarily supported single-span, or multi-span Euler–Bernoulli beam carrying any combination of miscellaneous attachments. The approach is obtained by solving a characteristic polynomial equation using a classical method for computing the roots of a polynomial. Interestingly, if the number of elements is greater than one, a pole-zero cancellation is needed, but it does not require manual interventions such as initial values and iteration. The mathematical approach is validated with bibliographic references and evaluated for accuracy and computational effectiveness. A good agreement is observed with relative error values practically negligible mostly ranging between 10−3 and 10−9 in the first five natural frequencies, which confirms the validity of the presented approach in this paper. The MatLab code that has been developed with the solving approach is freely available as a supplementary material to this paper. Additionally, a MatLab graphical user interface has also been developed in this work which allows to obtain the eigenvalues of a simply supported Euler–Bernoulli beam carrying an undetermined number of lumped elements. The graphical user interface is also available for download, along with help facilities to be run in a Windows operating system and detailed instructions to reproduce the case studies presented here. The proposed scheme (and also the MatLab graphical user interface) is very easy to code, and can be slightly modified to accommodate beams with arbitrary supports. [ABSTRACT FROM AUTHOR]

A static world assumption is often used when considering the simultaneous localization and mapping (SLAM) problem. In reality, especially when long-term autonomy is the objective, this is not a valid assumption. This paper studies a scenario where landmarks can occupy multiple discrete positions at different points in time, where each possible position is added to a multi-hypothesis map representation. A selector-mixture distribution is introduced and used in the observation model. Each landmark position hypothesis is associated with one component in the mixture. The landmark movements are modeled by a discrete Markov chain and the Monte Carlo tree search algorithm is suggested to be used as component selector. The non-static environment model is further incorporated into the factor graph formulation of the SLAM problem and is solved by iterating between estimating discrete variables with a component selector and optimizing continuous variables with an efficient state-of-the-art nonlinear least squares SLAM solver. The proposed non-static SLAM system is validated in numerical simulation and with a publicly available dataset by showing that a non-static environment can successfully be navigated. [ABSTRACT FROM AUTHOR]

This paper studies the continuous-time behavior of sampled-data control systems. In these systems, a discrete-time control law is applied to a continuous-time system model using sampling and zero-order hold. Traditionally, sampled-data systems are modeled in discrete-time, and thus, the intersample dynamics cannot be examined. This paper shows that the classical methods (such as the d2c function of MATLAB) for obtaining continuous-time models can be inaccurate between the sampling instants, even when Shannon's sampling theorem is satisfied. In this paper, a new method is also presented which can be used to characterize the continuous-time dynamics of sampled-data control systems. The new continuous-time system model including the intersample behavior is derived analytically from the discrete-time model, and the results are verified by simulations. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of determining the exact value of the maximum allowable upper bound (MAUB) of delay of an LTI system in the presence of the delay parameters. The delay parameter is supposed to be time-invariant, and this paper proposes a systematic method to exactly solve the mentioned problem. For this purpose, a modified system matrix is defined based on the delay system's model that involves an extra complex variable on the boundary of the unit circle. It will be shown that the characteristic polynomial of the modified system can equivalently assess the system's stability. The characteristic polynomial of the modified system is a quadratic function of the imaginary part of the extra complex variable which enables us to rewrite the polynomial based on only the real part of the extra variable. This property is exploited to develop an explicit formula to find the MAUB based on the critical numbers (complex numbers that force the modified characteristic polynomial to have pure imaginary roots) and their related pure imaginary roots. The method is tested for some sample delay systems and the results demonstrate a tighter bound for the MAUB of the systems. [ABSTRACT FROM AUTHOR]

Improving the control performance of dynamic vibration absorbers has recently been effective by introducing a grounded negative stiffness device. However, the negative stiffness structure is unstable and difficult to achieve in engineering practice , and its major drawback is that it amplif ies the vibration response of the primary system at low frequency region. Meanwhile, some mechanical devices can be combined to make the DVA work even better with a grounded positive stiffness. For this purpose, this paper combines for the first time the control effect of the inerter device and grounded positive stiffness into a three-element DVA model in order to better improve vibration reduction of an undamped primary system under excitation. First, the dynamic equation of motion of the system is written according to Newton 's second law. Then, the steady-state displacement response of the primary system under harmonic excitation is calculated. In order to minimize the resonant response of the primary system around its natural frequency, the extended fixed point theory is applied. Thus, the optimized parameters such as the tuning frequency ratio, the stiffness ratio , and the approximate damping ratio are determined as a function of mass ratio and inerter – mass ratio. From the results analysis, it was found that the inerter – mass ratio has a better working range to guarantee the stability of the coupled system. Then , study on the effect of inerter – mass ratio on the primary system response is carried out. It can be seen that increasing the inerter – mass ratio in the optimal working range can reduce the response of the primary system beyond its uncontrolled static response. However, it is necessary to avoid the situation where the inerter – mass ratio is very large because it can lead to unrealistic optimal parameters. Finally, comparison with other DVA models is show n under harmonic and random excitation of the primary system. It is found that the proposed DVA model in this paper has high control performance and can be used in many engineering practice s. [ABSTRACT FROM AUTHOR]

In this paper, a new adaptive method is proposed for online frequency estimation of a periodic disturbance by the output measurement based on the fast Fourier transform algorithm. The performance of the proposed algorithm is evaluated in the face of time varying frequency, time varying amplitude, non-sinusoidal periodic disturbance, and different plants. Also, the convergence rate of the method is compared by other estimation methods. Then, the online estimation is used in the repetitive controller structure for eliminating periodic disturbances with unknown frequencies. A new analysis is performed on RC and the stability conditions are determined in a theorem. These are illustrated in simulation results. The effectiveness of this method is shown on the application of ϕ -shaped PZT active suspension and it is compared by existing results. [ABSTRACT FROM AUTHOR]

The hunting motion of the vehicle increases the wear of the wheel tracks and affects the lateral stability of the vehicle system and safety, so the hunting motion of the vehicle needs to be recognized. However, the existing recognition methods ignore the small-amplitude hunting motion that precedes the onset of the running motion. In addition, due to the scarcity of real hunting data of high-speed trains, there is a problem of underfitting when training with traditional deep learning methods. In this paper, first, the dynamics model of a high-speed train is established, and the normal, small-amplitude hunting and hunting motions of high-speed trains in the process are simulated. Second, this paper proposes a transfer learning-based method for high-speed train hunting motion recognition. The method uses easily collected normal data samples in the training process, does not use real data samples of small-amplitude hunting and hunting motions, and completes the high-speed train running motions recognition task by transferring from simulation data (source domain) to real data (target domain). Finally, the validation is carried out using the real data, which proves that the method-related approach has some engineering application value in the intelligent monitoring of high-speed trains. [ABSTRACT FROM AUTHOR]

Reported analgesic use following experimental surgery is low in rodents and there has been little published information on the frequency of analgesic use in other laboratory species. A structured literature review was conducted to examine analgesic administration in larger laboratory animals. The Scirus search engine was used to identify studies published in peer-reviewed journals that reported carrying out experimental surgery on 'large' laboratory animals, specifically rabbits, pigs, sheep, dogs and non-human primates. Seventy-four studies between 2000 and 2001 and 75 studies between 2005 and 2006 were included in the review. There was an increase in the reported administration of systemic analgesics to these species from 50% in 2000-2001 to 63% in 2005-2006. When all agents with analgesic properties were considered (systemic analgesics, local anaesthetics and anaesthetics with analgesic components), the proportion of papers that reported some form of analgesic administration to 'large' laboratory animals increased from 86% in 2000-2001 to 89% in 2005-2006. Overall rabbits, pigs, sheep, dogs and non-human primates were more likely to receive analgesics following potentially painful experimental procedures than has been reported in laboratory rodents but analgesic administration to 'large' laboratory species is still not optimal. [ABSTRACT FROM AUTHOR]

The study is an attempt to understand the trends in LIS research by analyzing published literature on the topic. The study identifies and analyses 39 research papers on LIS research trends in various countries, three papers on LIS research trends in regional countries and 13 papers on LIS research trends with an international perspective. The findings of the study reveal that there is a similarity among various countries as far as the LIS research topics are concerned but with a different focus at different periods. While understanding international research trends in LIS, it was interesting to note that the research trend in China was similar to the worldwide research trend while the pattern in other countries differed. [ABSTRACT FROM AUTHOR]

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Does collaboration improve the quality of scientific research? Editorial decision on papers submitted to a leading social psychology journal was cross-classified by number of authors. A small relationship in the predicted direction was obtained and it persisted in the face of two relevant controls. [ABSTRACT FROM AUTHOR]

The article articulates a theory of citing behavior, which might both illuminate the currently available empirical findings on characteristics of references in scientific papers and perhaps indicate interesting but previously unexamined aspects of citation. Current studies can be divided into three groups according to the different ways they have employed citation data. Some studies have used the number of citations as an indication of its scientific quality, significance or worth. Likewise, the number of citations obtained by an author has been used to measure the impact of his or her work on the scientific community. In other studies, citation patterns have been employed to derive maps of the structure of scientific specialties and disciplines. The third approach can be seen in two recent attempts to construct typologies of different varieties of reference and citations by content analysis. Various studies have made some interesting contributions to the understanding of science and scientific activity. Nevertheless, their achievements have been obtained without the aid of an explicit and accepted theory concerning reasons why scientists normally cite other papers, and why authors choose to cite particular papers rather than others.

This paper introduces the inertial amplifier viscoelastic tuned mass dampers (IAVTMD). The viscoelastic materials are implanted inside the core material of the inertial amplifier tuned mass dampers. The standard linear solid models are applied mathematically to formulate the viscoelastic material. H 2 and H ∞ optimization mechanisms apply to derive the exact mathematical closed-form formulations for optimal design parameters for novel inertial amplifier viscoelastic tuned mass dampers. The optimum IAVTMD installs at the top of the structures to mitigate the dynamic responses, determining the dynamic responses analytically through transfer function formation. At first, IAVTMD's dynamic response reduction capacity compares with the conventional tuned mass damper's (CTMD) dynamic response reduction capacity. As a result, H 2 optimized IAVTMD's dynamic response reduction capacity is significantly 20.87% and 26.47% superior to two well-established H 2 optimized conventional tuned mass damper's dynamic response reduction capacity. In addition, H ∞ optimized IAVTMD has 15.48% more dynamic response reduction capacity than H ∞ conventional tuned mass damper. H 2 and H ∞ optimized tuned mass damper inerters with optimal closed-form solutions are introduced in this paper. A higher damper mass ratio and a lower inerter mass ratio are recommended to produce H 2 and H ∞ optimized tuned mass damper inerter (TMDI) with a lower frequency and damping ratio in an affordable range. Accordingly, H 2 and H ∞ optimized IAVTMD's dynamic response reduction capacities are significantly 6.94% and 23.29% superior to H 2 and H ∞ optimized TMDI's dynamic response reduction capacity. The closed-form expressions for optimal design parameters of inertial amplifier viscoelastic tuned mass dampers and tuned mass damper inerters are mathematically correct and effective for practical applications. [ABSTRACT FROM AUTHOR]

Intelligent fault diagnosis utilizing deep learning algorithms is currently a topic of great interest. When developing a new Convolutional Neural Network (CNN) architecture to address machine diagnosis problem, it is common to use a deep model, with many layers, many feature maps, and large kernels. These models are capable of learning complex relationships and can potentially achieve superior performance on test data. However, not only does a large network potentially impose undue computational complexity for training and eventual deployment, it may also lead to more brittleness—where data outside of the curated dataset used in CNN training and evaluation is poorly handled. Accordingly, this paper will investigate a methodical approach for identifying a quasi-optimal CNN architecture to maximize robustness when a model is trained under one set of operating conditions, and deployed under a different set of conditions. Optuna software will be used to optimize a baseline CNN model for robustness to different rotational speeds and bearing Model #'s. To further improve the network generalization capabilities, this paper proposes the addition of white Gaussian noise to the raw vibration training data. Results indicate that the number of trainable weights and associated multiplications in the optimized model were reduced by almost 95% without jeopardizing the network classification accuracy. Additionally, moderate Additive White Gaussian Noise (AWGN) improved the model adaptation capabilities. [ABSTRACT FROM AUTHOR]

In this paper, the scattering and vibration isolation of elastic waves from the open trench are analyzed and discussed in the time domain using the scaled boundary finite element method (SBFEM). Based on the theory of soil-structure interaction, the site with an open trench is decomposed into a near-field system and an infinite far-field system. The quadtree domain decomposition technique is employed for SBFEM mesh discretization of the near-field. The far-field is rigorously modeled by the displacement unit impulse response matrix. The obliquely plane elastic wave from the far-field is converted into a traction force acting on the near/far-field boundary. The time-space domain numerical model is established for elastic wave propagation in half-space with an open trench. Finally, through numerical examples to verify the effectiveness of the method of this paper, and parametric analyze the effect law of the incidence angle and the trench depth, etc., on the vibration isolation performance. [ABSTRACT FROM AUTHOR]