22,121 research outputs found

    Exploring The Value Of Folksonomies For Creating Semantic Metadata

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    Finding good keywords to describe resources is an on-going problem: typically we select such words manually from a thesaurus of terms, or they are created using automatic keyword extraction techniques. Folksonomies are an increasingly well populated source of unstructured tags describing web resources. This paper explores the value of the folksonomy tags as potential source of keyword metadata by examining the relationship between folksonomies, community produced annotations, and keywords extracted by machines. The experiment has been carried-out in two ways: subjectively, by asking two human indexers to evaluate the quality of the generated keywords from both systems; and automatically, by measuring the percentage of overlap between the folksonomy set and machine generated keywords set. The results of this experiment show that the folksonomy tags agree more closely with the human generated keywords than those automatically generated. The results also showed that the trained indexers preferred the semantics of folksonomy tags compared to keywords extracted automatically. These results can be considered as evidence for the strong relationship of folksonomies to the human indexer’s mindset, demonstrating that folksonomies used in the del.icio.us bookmarking service are a potential source for generating semantic metadata to annotate web resources

    Creating structure from disorder: using folksonomies to create semantic metadata

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    This paper reports on an on-going research project to create educational semantic metadata out of folksonomies. The paper describes a simple scenario for the usage of the generated semantic metadata in teaching, and describes the ‘FolksAnnotation’ tool which applies an organization scheme to tags in a specific domain of interest. The contribution of this paper is to describe an evaluation framework which will allow us to validate our claim that folksonomies are potentially a rich source of metadata

    Consumer confidence indeces and short-term forecasting of consumption

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    Recently there has been growing interest in examining the potential shortterm link between survey-based confidence indicators and real economic activity, notably for macroeconomic policy making. This paper builds on previous studies to establish whether there is a short-term predictive relationship between measures of consumer confidence and actual consumption, that could be used for forecasting, in a range of major industrial countries. It then extends such previous analyses by assessing whether this relation has changed over time, and whether we can attribute any time-varying relation to structural developments in the economy, such as financial deepening and the increasing role of house prices in determination of consumption

    The design, kinematics and torque analysis of the self-bending soft contraction actuator

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    This article presents the development of a self-bending contraction actuator (SBCA) through analysis of its structure, kinematics, and torque formulas, and then explores its applications. The proposed actuator has been fabricated by two methods to prove the efficiency of the human body inspiration, which represents the covering of human bones by soft tissues to protect the bone and give the soft texture. The SBCA provides bending behaviour along with a high force to-weight ratio. As with the simple pneumatic muscle actuator (PMA), the SBCA is soft and easy to implement. Both the kinematics and the torque formula presented for the SBCA are scalable and can be used with different actuator sizes. The bending actuator has been tested under an air pressure up to 500 kPa, and the behaviour of its bending angle, parameters, dimensions, and the bending torques have been illustrated. On the other hand, the experiments showed the efficient performances of the actuator and validate the proposed kinematics. Therefore, the actuator can be used in many different applications, such as soft grippers and continuum arms

    Consumer confidence indices and short-term forecasting of consumption

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    Recently there has been growing interest in examining the potential shortterm link between survey-based confidence indicators and real economic activity, notably for macroeconomic policy making. This paper builds on previous studies to establish whether there is a short-term predictive relationship between measures of consumer confidence and actual consumption, that could be used for forecasting, in a range of major industrial countries. It then extends such previous analyses by assessing whether this relation has changed over time, and whether we can attribute any time-varying relation to structural developments in the economy, such as financial deepening and the increasing role of house prices in determination of consumption

    3D position mapping of continuum arm

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    Modelling a continuum arm is one of the major challenges in soft robotic researches. An accurate position model allows wider use of continuum robot arms in industrial and medical applications. Furthermore, accurate control can be achieved. This paper illustrates the 3D position of a constructed soft arm from 4 pneumatic muscle actuators (PMAs) in parallel, and models the movement of its free end in space. The performance of the contraction and extension PMAs and the behaviour of the contraction and extension arms are analysed, and a comparison between the two arms is explained. Finally, the mathematical models are presented and validated

    A circular pneumatic muscle actuator (CPMA) inspired by human skeletal muscles

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    This paper illustrates the design, implementation and kinematics of a novel circular pneumatic muscle actuator (CPMA), inspired by the skeletal muscles of a human. The variation of the inner diameter of this actuator is a unique feature. Furthermore, CPMA produces a radial force towards its centre by increasing the diameter of the actuator itself in addition to the reduction in the inner diameter. These performances make the presented actuator suitable to use in numerous applications. The grasping by a soft gripper is chosen as an application to design an efficient soft gripper by using single and multiple CPMAs

    Novel models for the extension pneumatic muscle actuator performances

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    This paper illustrates the design, implementation and modelling of the extensor pneumatic muscle actuator (PMA). The extensor soft actuator has a vital feature of ability to bend and extend, and that give it the flexibility to use in numerous applications. The extended behaviour of this actuator is modelled mathematically to be used to predict the length of a wide range of actuators at different air pressure amounts and make the position control of such type of actuator easier and precise. Moreover, the contraction force formula is modified to describe the pushing force for the extensor actuator. The bending behaviour of single muscle is explained and a 4-PMA continuum arm has been constructed to study its performance and model the bending angle

    Design of a variable stiffness soft dexterous gripper

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    This article presents the design of a variable stiffness, soft, three fingered dexterous gripper. The gripper uses two designs of McKibben muscles. Extensor muscles which increase in length when pressurised are used to form the fingers of the gripper. Contractor muscles which decrease in length when pressurised are then used to apply forces to the fingers via tendons which cause flexion and extension of the fingers. The two types of muscles are arranged to act antagonistically and this means that by raising the pressure in all of the pneumatic muscles the stiffness of the system can be increased without a resulting change in finger position. The article presents the design of the gripper, some basic kinematics to describe its function and then experimental results demonstrating the ability to adjust the bending stiffness of the gripper’s fingers. It has been demonstrated that the finger’s bending stiffness can be increased by over 150%. The article concludes by demonstrating that the fingers can be closed loop position controlled and are able to track step and sinusoidal inputs
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