362 research outputs found

    Corruption in International Arbitration

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    Corruption represents a great menace to national and international development. It jeopardizes democracy, human rights, and social justice. Consequently, corruption is vehemently abhorred and denunciated by members of the international arbitration arena. Unfortunately, while these players purport repugnance towards corruption and do not condone corrupt acts, there has arisen a misplaced distrust of arbitral process as a proper dispute resolution system. Further, when amalgamating the inherent opaqueness of the arbitral process, its structure founded upon party autonomy, and the clear lack of authority for arbitrators to compel evidence, such distrust persists and encourages belief that arbitration is a venue where agreements vitiated by corruption find legitimization and enforcement. Within this hostile climate, issues of corruption proffer challenges to the arbitral system and impose, simultaneously, arduous tasks and great responsibility upon arbitrators. Indisputably, corruption’s involvement in arbitration is far from novel. Nonetheless, there remains a lack of uniformity among arbitral tribunals on how to tackle corruption. The core issues causing divergence include: (i) arbitrability and admissibility of corruption issues; (ii) the burden of proof and the standard of proof; (iii) sua sponte arbitrator investigation and inquiry into corruption; (iv) disclosing corruption to arbitral institutions and public authorities; (v) and proper judicial review of an arbitral award when the legality of the award is challenged on the basis of corruption. This study delineates these controversial concerns and analyzes practical solutions within the context of theory and practice. Further, this study scrutinizes commercial and investment-treaty arbitration cases, national and international court judgments, international conventions, national statutes, plus, other materials exploring corruption and arbitration. By referencing a wide collection of historic and contemporary sources, this study will aid practitioners and scholars interested in the ongoing interaction between corruption and arbitration

    Extending The Lossy Spring-Loaded Inverted Pendulum Model with a Slider-Crank Mechanism

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    Spring Loaded Inverted Pendulum (SLIP) model has a long history in describing running behavior in animals and humans as well as has been used as a design basis for robots capable of dynamic locomotion. Anchoring the SLIP for lossy physical systems resulted in newer models which are extended versions of original SLIP with viscous damping in the leg. However, such lossy models require an additional mechanism for pumping energy to the system to control the locomotion and to reach a limit-cycle. Some studies solved this problem by adding an actively controllable torque actuation at the hip joint and this actuation has been successively used in many robotic platforms, such as the popular RHex robot. However, hip torque actuation produces forces on the COM dominantly at forward direction with respect to ground, making height control challenging especially at slow speeds. The situation becomes more severe when the horizontal speed of the robot reaches zero, i.e. steady hoping without moving in horizontal direction, and the system reaches to singularity in which vertical degrees of freedom is completely lost. To this end, we propose an extension of the lossy SLIP model with a slider-crank mechanism, SLIP- SCM, that can generate a stable limit-cycle when the body is constrained to vertical direction. We propose an approximate analytical solution to the nonlinear system dynamics of SLIP- SCM model to characterize its behavior during the locomotion. Finally, we perform a fixed-point stability analysis on SLIP-SCM model using our approximate analytical solution and show that proposed model exhibits stable behavior in our range of interest.Comment: To appear in The 17th International Conference on Advanced Robotic

    Template Based Control of Hexapedal Running

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    In this paper, we introduce a hexapedal locomotion controller that simulation evidence suggests will be capable of driving our RHex robot at speeds exceeding five body lengths per second with reliable stability and rapid maneuverability. We use a low dimensional passively compliant biped as a template -- a control target for the alternating tripod gait of the physical machine. We impose upon the physical machine an approrimate inverse dynamics within-stride controller designed to force the true high dimensional system dynamics down onto the lower dimensional subspace corresponding to the template. Numerical simulations suggest the presence of asymptotically stable mnning gaits with large basins of attraction. Moreover, this controller improves substantially the maneuverability and dynamic range of RHex\u27s running behaviors relative to the initial prototype open-loop algorithms

    Back Flips with a Hexapedal Robot

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    We report on the design and analysis of a controller which can achieve dynamical self-righting of our hexapedal robot, RHex. We present an empirically developed control procedure which works reasonably well on indoor surfaces, using a hybrid energy pumping strategy to overcome torque limitations of its actuators. Subsequent modeling and analysis yields a new controller with a much wider domain of success as well as a preliminary understanding of the necessary hybrid control strategy. Simulation results demonstrate the superiority of the improved control strategy to the first generation empirically designed controller

    Parametric Working Memory of Abstract Quantities on Multiple Modalities and Formats : from Frequency to Numerosity

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    Working memory is central to the complex cognitive functions that are involved in goal-directed behavior. At the core of working memory research, the question remains how and in what format information is retained in the brain. Immense progress has been made using neuroimaging to determine the location of information maintenance using experiments with sensory features, however, it remains unclear how more abstract stimuli are stored. The aim of this dissertation is to uncover the neural underpinnings of working memory during abstract quantity processing. Specifically, I conducted three functional magnetic resonance imaging (fMRI) studies to address the question of which brain regions represent the abstract quantity content. We found parametric working memory representation of auditory, visual and vibrotactile frequencies distributed across sensory, posterior parietal, and prefrontal cortices. Additionally, the numerosity-specific information is represented in the prefrontal cortex. These results provide novel insights into how the brain maintains information in working memory and give support to the view that mental representations are distributed across the cortex depending on whether they are maintained as sensory-specific or abstract features

    Suhrawardı’s Criticism of Avicenna’s Epistemology With A Special Emphasis on the Theory of Essential Definition

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    prof. Tahir Uluç, Selçuk Üniversitesi, Konya; Divinity School of Konya University, TurkeyThis paper is intended to compare the epistemologies of two major schools of classical Islamic philosophy, namely, the Mash ̄ash ̄a ̄ıyya and the Ishr ̄aqiyya. The term Mash ̄ash ̄aiyya is the literal Arabic translation of Peripateticism that refers to the Islamic philosophical school that is largely characterized by Aristotelianism and Neoplatonism and is represented by Alpharabius, Avicenna, and Averroes. As for the Arabic term Ishr ̄aqiyya, meaning literally illuminationism, designates the philosophical school, founded by Shih ̄ab al-D ̄ın Suhraward ̄ı, which is composed of such a broad range of elements as Platonism, Neoplatonism, Pythagorianism as well as Islamic mysticism, pre-Islamic Persian angelology and symbolism. One, however, can reduce Suhraward ̄ı’s illuminationism to a twofold structure: theoretical and philosophical on one hand and intuitional and mystical on the other. The latter consists largely of Suhraward ̄ı’s extensive critique of Avicenna’s views in the fields of epistemology, physics, and metaphysics. The present study aims at elaborating on his critique of Avicenna’s epistemology with a special emphasis on the latter’s theory of definition

    Model-Based Dynamic Self-Righting Maneuvers for a Hexapedal Robot

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    We report on the design and analysis of a controller that can achieve dynamical self-righting of our hexapedal robot, RHex. Motivated by the initial success of an empirically tuned controller, we present a feedback controller based on a saggital plane model of the robot. We also extend this controller to develop a hybrid pumping strategy that overcomes actuator torque limitations, resulting in robust flipping behavior over a wide range of surfaces. We present simulations and experiments to validate the model and characterize the performance of the new controller

    Heterogeneous effects and spillovers of macroprudential policy in an agent-based model of the UK housing market

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    Desarrollamos un modelo basado en agentes para estudiar el impacto de experimentos de política macroprudencial sobre los principales indicadores del mercado inmobiliario del Reino Unido. La naturaleza heterogénea de este modelo nos permite evaluar el efecto de tales experimentos sobre los mercados de compra, alquiler y crédito hipotecario no solo de forma agregada, sino también a nivel de hogares individuales y subsegmentos tales como los compradores de primera vivienda, los propietarios, los inversores en vivienda para alquilar y los inquilinos. Este enfoque puede así ofrecer una visión general de los efectos desagregados de las políticas de estabilidad financiera. El modelo está calibrado con una amplia selección de fuentes de microdatos: incluye datos tanto de un destacado portal inmobiliario del Reino Unido como de regulación préstamo a préstamo. Mediante una serie de ejercicios de estática comparativa, investigamos el impacto de: i) un límite rígido de la ratio préstamo-valor, y ii) un límite suave de la ratio préstamo-ingresos, permitiendo que una determinada fracción de las nuevas hipotecas supere esta restricción. En primer lugar, encontramos que estos experimentos tienden a mitigar el ciclo de precios del mercado inmobiliario, lo que reduce la disponibilidad de crédito y, por tanto, el apalancamiento. En segundo lugar, un experimento que tenga por objetivo una particular medida del riesgo puede afectar también a otras métricas de riesgo; se hace así necesaria una cuidadosa calibración de la política para lograr una determinada reducción del riesgo. Por último, experimentos enfocados al mercado de compraventa de vivienda principal pueden tener efectos colaterales sobre el sector del alquiler, como resultado de un cambio composicional en la propiedad inmobiliaria desde ocupantes propietarios hacia inversores en vivienda para alquilar que afecta tanto a la oferta como a la demanda de viviendas en alquiler.We develop an agent-based model of the UK housing market to study the impact of macroprudential policy experiments on key housing market indicators. The heterogeneous nature of this model enables us to assess the effects of such experiments on the housing, rental and mortgage markets not only in the aggregate, but also at the level of individual households and sub-segments, such as first-time buyers, homeowners, buy-to-let investors, and renters. This approach can therefore offer a broad picture of the disaggregated effects of financial stability policies. The model is calibrated using a large selection of micro-data, including data from a leading UK real estate online search engine as well as loan-level regulatory data. With a series of comparative statics exercises, we investigate the impact of: i) a hard loan-to-value limit, and ii) a soft loan-to-income limit, allowing for a limited share of unconstrained new mortgages. We find that, first, these experiments tend to mitigate the house price cycle by reducing credit availability and therefore leverage. Second, an experiment targeting a specific risk measure may also affect other risk metrics, thus necessitating a careful calibration of the policy to achieve a given reduction in risk. Third, experiments targeting the owner-occupier housing market can spill over to the rental sector, as a compositional shift in home ownership from owner-occupiers to buy-to-let investors affects both the supply of and demand for rental properties

    Proprioception Based Behavioral Advances in a Hexapod Robot

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    We report on our progress in extending the behavioral repertoire of RHex, a compliant leg hexapod robot. We introduce two new controllers, one for climbing constant slope inclinations and one for achieving higher speeds via pronking, a gait that incorporates a, substantial aerial phase. In both cases, we make use of an underlying open-loop control strategy, combined with low bandwidth feedback to modulate its parameters. The inclination behavior arises from our initial alternating tripod walking controller and adjusts the angle offsets of individual leg motion profiles based on inertial sensing of the average surface slope. Similarly, the pronking controller makes use of a virtual leg touchdown sensing mechanism to adjust the frequency of the open-loop pronking, effectively synchronizing the controller with the natural oscillations of the mechanical system. Experimental results demonstrate good performance on slopes inclined up to /spl sim/250 and pronking up to speeds approaching 2 body lengths per second (/spl sim/1.0 m/s)

    Synthesis and characterization of phosphorescent strontium aluminate compounds

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    The emission of light after the excitation source is switched off is known as phosphorescence. Phosphorescence occurs when suitable elements with active electronic configuration are doped into certain host materials. For an efficient phosphorescence emission (long after glow time and high intensity), both the dopant ion and the host material are critical. Strontium aluminates, such as SrAl2O4, SrAl4O7, SrAl12O19, have gained attention for the last two decades due to their phosphorescence behavior upon doping with rare earth elements such as Eu, and Dy. These phosphorescent materials are superior to other materials of this kind as they have long after glow times with high quantum efficiency; they are easy to produce with alternating methods and are low cost materials. The focus of this thesis is on the different stoichiometric compounds of strontium aluminates with the dopants Eu2+, Dy3+, and boron. Eu2+ introduces phosphorescence whereas Dy3+ is used to increase the after glow time. Boron on the other hand improves the crystallinity, and also the after glow time. The general aim of this thesis is to develop materials with long after glow duration i.e more than one hour. A modified version of the Pechini process is proposed in order to accomplish the objective. The proposed procedure is one step ahead from the previous studies as it is an easy, lowtemperature and low-cost method. Moreover, by the proposed method, strontium aluminate compounds can be incorporated with up to 30% boron without disturbing the crystal lattice and hence without lowering the crystallinity. These advantages are also verified experimentally
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