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The Suaineadh Project : A stepping stone towards the deployment of large flexible structures in space

The Suaineadh Project : A stepping stone towards the deployment of large flexible structures in space

The Suaineadh project aims at testing the controlled deployment and stabilization of space web. The deployment system is based on a simple yet ingenious control of the centrifugal force that will pull each of the four daughters sections apart. The four daughters are attached onto the four corners of a square web, and will be released from their initial stowed configuration attached to a central hub. Enclosed in the central hub is a specifically designed spinning reaction wheel that controls the rotational speed with a closed loop control fed by measurements from an onboard inertial measurement sensor. Five other such sensors located within the web and central hub provide information on the surface curvature of the web, and progression of the deployment. Suaineadh is currently at an advanced stage of development: all the components are manufactured with the subsystems integrated and are presently awaiting full integration and testing. This paper will present the current status of the Suaineadh project and the results of the most recent set of tests. In particular, the paper will cover the overall mechanical design of the system, the electrical and sensor assemblies, the communication and power systems and the spinning wheel with its control system.
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Earthquake dynamic response of large flexible multibody systems

Earthquake dynamic response of large flexible multibody systems

There are not enough studies on the influence of the seis- mic loading to the WPG and in many cases the influence of such loading is not taken into account in the design process. The main purpose of the structural model of a wind turbine is to be able to determine temporal variation of the loads in var- ious components in order to estimate fatigue damage. To cal- culate the deflections and velocities of various components in the wind turbine in the time domain, a precise dynamic model including the inertia terms is needed. The wind tur- bines are large flexible structures (more than 150 m in di- ameter) which blades implement complex motion in space with high velocities and rapidly changing accelerations of the blade deflections. The vibrations cause unstable work- ing conditions, noise and random loads of the units. Because of the changing external loading over the blades the turbine shaft is imposed on bending and torsion including also im- pacts in the bearings.
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Distributed Parameter-Dependent Control of Non-Uniform Flexible Structures

Distributed Parameter-Dependent Control of Non-Uniform Flexible Structures

The control of flexible structures has been one of the most active fields of research for the last two decades partly due to increased interest in high-speed robotics and space applications. In the construction of large space structures, for example, low- mass density materials need to be used due to the high launch cost. Since these materials are also lightly damped, the increased flexibility of space structures may allow large amplitude vibration, which may cause structural instability. In high-speed industrial robotics applications, however, the highly flexible nature of the links leads to a challenging problem of end-point trajectory control. Therefore, sophisticated controllers that enhance the stiffness and damping properties of these structures are needed to overcome these problems.
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Sun-3_Hardware_Configuration_Guide_Nov89.pdf

Sun-3_Hardware_Configuration_Guide_Nov89.pdf

Large virtual address space requires large disk swap space in addition to the data storage requirements of the.. applications.[r]

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Level Set of Measurable Conjugate Flexible Fuzzy Soft Bi-Ideals Over Near-Ring Structures

Level Set of Measurable Conjugate Flexible Fuzzy Soft Bi-Ideals Over Near-Ring Structures

Zadeh′s classical paper [27] of 1965 introduced the concepts of fuzzy sets and fuzzy set operations. Foster [7] combined the structure of a fuzzy topological space. The study of the fuzzy algebraic structures started with the introduction of concepts of fuzzy subgroups and fuzzy (left, right) ideals in the pioneering paper of Rosenfeld [17]. Anthony and Sherwood [1] redefined fuzzy subgroups using the concept of triangular norm. Several mathematicians [6,8,10] followed the Rosenfeld approach in investigating fuzzy algebra where given ordinary algebraic structure on a given set X is assumed then introducing the fuzzy algebraic structure as a fuzzy subset A of X satisfying some suitable conditions. Throughout this paper, G will denote a group and "e" will denote its identity element. Let sup, inf, min, max will denote thesupermum, infimum, minimum, maximum respectively. Flexible fuzzy soft subgroups in various algebraic structures defined in [23-26]. Many researchers Abd-Allahet.al [2], Chengyi [5], Dib and Hassan [6], Tang and Zhang [22], Syransu and Ruy [19], Massa'deh [12] studied the properties of groups and subgroups by the definition of fuzzy subgroups. In this paper, we introduce the notion of flexible fuzzy soft ideals in near –ring structures, level sets and given some characterizations of flexible fuzzy soft ideals in near-ring approximations.
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Gaussian Processes for Machine Learning (GPML) Toolbox

Gaussian Processes for Machine Learning (GPML) Toolbox

The GPML toolbox can be obtained from http://gaussianprocess.org/gpml/code/matlab/ and also http://mloss.org/software/view/263/ under the FreeBSD license. Based on simple interfaces for covariance, mean, likelihood functions as well as inference methods, we offer full compatibility to both Matlab 7.x 2 and GNU Octave 3.2.x. 3 Special attention has been given to properly disentangle covariance, likelihood and mean hyperparameters. Also, care has been taken to avoid numerical inaccuracies, for example, safe likelihood evaluations for extreme inputs and stable matrix operations. For example, the covariance matrix K can become numerically close to singular making its naive inversion numerically unsafe. We handle these situations in a principled way 4 such that Cholesky decompositions are computed of well-conditioned matrices only. As a result, our code shows a high level of robustness along the full spectrum of possible hyperparameters. The focus of the toolbox is on approximate inference using dense matrix algebra. We currently do not support covariance matrix approximation techniques to deal with large numbers of training examples n. Looking at the (growing) body of literature on sparse approximations, this knowledge is still somewhat in flux, and consensus on the best approaches has not yet been reached.
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Exploring the impact of a flexible, technology enhanced teaching space on pedagogy

Exploring the impact of a flexible, technology enhanced teaching space on pedagogy

The Teaching Grid provides a space in which colleagues from across the University can experiment with new teaching ideas that make effective use of space and technology, and identify what works within their context. Academics made use of this flexible, collaborative and technology rich space provided to explore a range of teaching strategies and support a wide range of student needs. Staff valued the flexibility for supporting group work. They displayed enthusiasm for making the most of the technology and commented on the value of being able to combine the use of flexible space and multiple technologies.
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Granular Space and the Problem of Large Numbers

Granular Space and the Problem of Large Numbers

notion has been widely used in modern physics ever since. The properties of granular space are studied in this article on the assumption that a three-dimensional material cell with the size of Planck’s elementary length is the only material for the construction of the whole Universe. This approach allows one to account for such mysterious phenomena as inertia, ultimate velocity of transfer of material body interactions and huge difference between gravitational and Coulomb forces - the so called “Large Numbers Problem”, as well essence of electric charge and Pauli exclusions principle.
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Seismic Resistant Design of Structures in the Low to Medium Seismicity Countries: Flexible Structures for Economic Construction

Seismic Resistant Design of Structures in the Low to Medium Seismicity Countries: Flexible Structures for Economic Construction

Over the past two decades a group of local researchers in Malaysia have worked on developing seismic hazard maps for Malaysia using the Probabilistic Seismic Hazard Analysis (PSHA) and earthquake data from the surrounding tectonic plate margins. The first seismic hazard maps in the form of Peak Ground Acceleration (PGA) maps of Malaysia were developed by the Malaysian Meteorological Department (MMD) in 2007 by converting seismic intensities into PGA. Currently PGA maps developed by local researchers are still under review by the government of Malaysia (Malaysian Standards Department) before they can be incorporated in the Malaysian National Annex to MS EN 1998-1: Eurocode 8: Design of Structures for Earthquake Resistance. It should also be noted that while there have been efforts by certain parties and researchers to construct earthquake design spectrum for Malaysia the government, as the authority, has yet to render the proposed design spectrum as suitable for use in Malaysia. Hence, engineers, practitioners and regulators do not have a confirmed guide that can be used in the design of earthquake resistant structures.
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Basic Study of the Human Foot

Basic Study of the Human Foot

Further evolution led into the amniotes who laid eggs on land and slowly began to be occupants of the land. They had tarsal bones which were fused to form the astragalus and the calcineum which were later called the talus and calcaneus respectively. Their locomotory structures contained upright limbs attached better suited for walking.

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Geographies of a Writing Space: The Study of a Flexible Composition Classroom.

Geographies of a Writing Space: The Study of a Flexible Composition Classroom.

environments that support different behaviors. She characterized spaces that are more fluid and adaptable, support collaborative, creative, and iterative processes as Environments for Creating Knowledge (ECK); on the other hand, Environments for Delivering Knowledge (EDK) are typically characterized by a layout where a presenter or authority figure transmits information from a central location in the space (usually the front). Based on her system of classification, the flexible classroom falls into the category of an ECK, as the data suggest this design supported collaborative peer review, iterative writing processes and activities for students, and gave the instructor the ability to position himself away from the classroom front, although not completely (as noted in from the student data in Chapter 4). Having a greater sense of proximity and connection to the instructor could also be a benefit for students who do not consider themselves strong writers, as demonstrated by comments by Doug, where he noted that the flexible space was particularly appropriate for English because he needed more “one-on-one” attention when he was in class. Such a space can be beneficial to students who lack confidence in their writing, as they may not be willing to approach their instructor outside of the classroom; therefore, having a learning space that is more mobile and comfortable can allow student and instructor to interact in more meaningful ways. While both the instructor and students noted that, at times, the space could be crowded and
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Investigating the Structural Compaction of Biomolecules Upon Transition to the Gas-Phase Using ESI-TWIMS-MS

Investigating the Structural Compaction of Biomolecules Upon Transition to the Gas-Phase Using ESI-TWIMS-MS

The question remains: can the solution structure of proteins be retained upon transfer into the gas phase? For stable, globular proteins, the answer is undoubtedly Byes,^ backed by an impressive number of literature examples. However, here we have presented a small number of protein exam- ples from our 14 years ’ experience with ESI-IMS-MS where we have found that the CCS values measured un- derestimate the physical size of the solution structure and modeled data of the biomolecule under scrutiny. This phenomenon has been reported elsewhere in the case of antibodies [26–28], but here we have shown by studying isolated regions of an antibody that the Fc region, which contains the majority of the flexible hinge region, is more prone to gas-phase compaction than the Fab region. Other proteins we have identified that undergo gas-phase com- paction include those with flexible hinge regions in be- tween more structured domains, such as an engineered concatamer, (I27) 5 , in addition to the BamA complex with
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Earthquake Effects on Large Floating Structures

Earthquake Effects on Large Floating Structures

The interest in large floating structures has increased in recent times in many sectors. Large floating structures, sometimes termed Very Large Floating Structures (VLFSs), can be used to support safety- related facilities and functions, as well as airports, bridges and piers and entertainment facilities. VLFSs fall into two categories: pontoon type and semi-submersible type. Pontoon types simply float on the water surface and are very flexible structures; elastic deformations are more important than rigid body motions and therefore hydroelastic analysis is critical in the design. Semi-submersible types are a simple box structure that is anchored by column tubes, piles or other bracing systems. In the open sea where large wave heights are commonplace, semi-submersible VLFSs can be used to minimise the effects of waves whilst maintaining a constant buoyancy force.
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Modelling desiccation shrinkage of large structures

Modelling desiccation shrinkage of large structures

Abstract. Drying of cement-based materials induces drying shrinkage, which may cause prestress loss or/and cracking if strains are (self or externally) restrained. Drying shrinkage is difficult to predict, since it depends on the material mix, mechanical and hygral boundary conditions, geometry ... This paper focuses on the study of size effect on final drying shrinkage, which is not well documented in the literature. In the Eurocode 2 (European code model), a reduction factor is applied for large structure, which is in agreement with experimental data of one campaign (found in the literature). Using numerical simulations, it is shown that a large panel of models, including phenomenological models as physical ones (which takes into account of (aging) creep under capillary pressure (assumed to be the physical mechanism for drying shrinkage)), do not predict size effect on final value of drying shrinkage.
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Analysis of Packaging and Deployment of Ultralight Space Structures

Analysis of Packaging and Deployment of Ultralight Space Structures

Benchmark problems have been compared to determine the relative effectiveness of Sierra Solid Mechanics code, both implicit and explicit, and LS-Dyna explicit code [30, 41]. One study by researchers at JPL investigated four benchmark problems, including the dynamics of three masses connected with highly flexible straps, and fabric contacting flexible straps. They compared the multi-body code MSC/ADAMS, the explicit solver in LS-Dyna, and the implicit and explicit solvers within Sierra Solid Mechanics finite element codes. The most significant result was all three codes could handle the presence of contact between flexible bodies, but required varying degrees of simula- tion tuning to be convergent. For example, the Sierra implicit parallel solver was found to function up to two orders of magnitude faster than the corresponding explicit solver for a given number of processors. However, this advantage was found to degrade in the presence of high speed contacts and for soft contact.
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Common fixed point results in function weighted metric spaces

Common fixed point results in function weighted metric spaces

As it seen clearly, the only difference between a “standard metric space” and a “function weighted metric space” is the last axiom: In a “function weighted metric space” instead of “the triangle inequality”, another axiom has been used, namely “generalized f -weighted triangle inequality axiom.” Based on this observation, we also easily conclude that any met- ric on X is an F -metric on X by letting f (t) = ln t for the axiom ( 3 ). Indeed, on account

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Synthesis and Characterization of Amphiphilic Iron-Sulfur Core Dendrimers

Synthesis and Characterization of Amphiphilic Iron-Sulfur Core Dendrimers

A core may consist of a single metal atom, a metal cluster or a polymer. The dendrons consist of organic and/or inorganic materials with specific repeat units. The strength and type of interaction between dendrons and core is determined by the choice of the focal point. The peripheral groups also play a very important role in dendritic structures assuming an extended architecture. These groups are the point of interaction between the dendrimer and the surrounding environment and affect properties such as solubility and diffusion coefficient. [3, 5, 10, 11, 13, 34, 36, 68, 70]. When dendrimer generation increases by one the number of peripheral groups doubles. The total number of peripheral groups for any generation of the dendron may be found using 2 n , where n is the dendron generation.
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Identification and Control of Flexible Structures Supported on Active Magnetic Bearings

Identification and Control of Flexible Structures Supported on Active Magnetic Bearings

The development of dynamic models of the flexible rotor and actuator enabled various controllers to be tried and tested in a realistic simulation environment before being applied experimentally. This provided insights as to how the rotor would react when forces were applied on different locations and the implications on position control. The validation of controller performance and robustness was paramount, and eve ry effort was made to ensure that there was close correspondence between the simulation and experimental pole-placement regulators.

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Comparison of Flow Structures in the Downstream Region of a Cylinder with Flexible Strip

Comparison of Flow Structures in the Downstream Region of a Cylinder with Flexible Strip

Figures 4-5 show the contours of the normalized TKE for the two models at Re = 2500. When the flow structures of the cylinder are compared to those of the atteached cylinder for two different images, both cylinders have two maxima of TKE. A high rate of entrainment between the free-stream and the wake flow regions is developed, and hence the two peak values of the TKE occur on both side of the cylinder symmetry plane. Minimum and incremental values are ±0.005 and 0.01 respectively. The peak value of the TKE for the bare cylinder has a value of 0.21 and that for attached cylinder is 0.145 for boundary level at L/D=4. On the other hand, while maximum TKE values are 0.19 and 0.1 for bare cylinder and attached body for up section.
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Uniform Structures Compatible with a Given Topological Space

Uniform Structures Compatible with a Given Topological Space

In particular it is proved that the uniformity 𝒰 generated by continuous real valued functions on X is compatible with topology of X if and only if X is completely regular..[r]

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