Search results for: outer space treaty
3569 The Effects of European Union’s Bordering Process
Authors: Ebru Dalgakiran
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Border and bordering studies have come to the forefront in recent years especially with parallel to increase in international migratory movements. Although conceptualizations of the border and bordering are quite contested within academia, the general point of view is that borders are politically and socially constructed. It means that borders have always their own ‘us vs. them’, and bordering process produce separate identities as well. In that case, Turkey and Greece are notable examples since these two nation-states constructed their borders upon each other’s for years although the Turkish-Greek border was drawn with the Lausanne Treaty of 1923. Nevertheless, on the other hand, The European Union (EU) has been externalized of border management policies to build a stronger area of freedom, security, and justice within the borders. Thus, Turkish-Greek border has become one of the significant external borders of the EU. In this context, this study aims to understand whether the EU’s bordering process through externalizing border management policies can affect Turkey’s and Greece’s bordering processes. By examining official documents of the EU and conducting in-depth interviews with local actors of the border management policies of the EU in Edirne, where is the border city of Turkey with Greece, this study’s main finding is that the EU’s bordering process to control migration at the external borders affects Turkey’s and Greece’s bordering processes. It seems that Turkey and Greece construct their borders upon a common Other, ‘irregular migrants’ now.Keywords: border, bordering, the European Union, externalization
Procedia PDF Downloads 2363568 Optimization of Structures Subjected to Earthquake
Authors: Alireza Lavaei, Alireza Lohrasbi, Mohammadali M. Shahlaei
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To reduce the overall time of structural optimization for earthquake loads two strategies are adopted. In the first strategy, a neural system consisting self-organizing map and radial basis function neural networks, is utilized to predict the time history responses. In this case, the input space is classified by employing a self-organizing map neural network. Then a distinct RBF neural network is trained in each class. In the second strategy, an improved genetic algorithm is employed to find the optimum design. A 72-bar space truss is designed for optimal weight using exact and approximate analysis for the El Centro (S-E 1940) earthquake loading. The numerical results demonstrate the computational advantages and effectiveness of the proposed method.Keywords: optimization, genetic algorithm, neural networks, self-organizing map
Procedia PDF Downloads 3113567 Political Implications of Shared Authority: Efforts to Retain Indigenous Sovereignty Within the Modern Global Power Structures
Authors: David E. Wilkins
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While colonialism in its many guises remains the dominant theoretical framework within which to analyze Indigenous relations with state powers, this paper takes a deep look at the treaty, policy, and statutory efforts initiated by both Indigenous peoples and colonial, and later federal representatives within what is now the United States that were intended to create a Native constituent state of the union. While these plans ultimately failed, they are indicative of the reality that, throughout much of the shared Indigenous and American history, there were both Native and non-Native political elites who were keen on the idea of incorporating Indigenous peoples into the burgeoning body politic. This paper explores why these plans arose, who the architects were that devised them, which Native peoples were involved in, and why they ultimately failed to be enacted. Although governmental relations within the US remain fraught and unpredictable, Native nations continue to wield a form of sovereignty that, while truncated, has maintained their distinctive political statuses. There is much to be learned from the exploration of these mixed successes and failures. There are other examples across the globe whereby Indigenous peoples like the Saami and the Māori have secured greater clarity of their retained autonomy through structural political arrangements with the states that have laid claim to their territories while the Ainu struggle to regain their status.Keywords: indigenous, sovereignty, diplomacy, intergovernmental
Procedia PDF Downloads 663566 Artificial Intelligent Tax Simulator to Minimize Tax Liability for Multinational Corporations
Authors: Sean Goltz, Michael Mayo
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The purpose of this research is to use Global-Regulation.com database of the world laws, focusing on tax treaties between countries, in order to create an AI-driven tax simulator that will run an AI agent through potential tax scenarios across countries. The AI agent goal is to identify the scenario that will result in minimum tax liability based on tax treaties between countries. The results will be visualized by a three dimensional matrix. This will be an online web application. Multinational corporations are running their business through multiple countries. These countries, in turn, have a tax treaty with many other countries to regulate the payment of taxes on income that is transferred between these countries. As a result, planning the best tax scenario across multiple countries and numerous tax treaties is almost impossible. This research propose to use Global-Regulation.com database of word laws in English (machine translated by Google and Microsoft API’s) in order to create a simulator that will include the information in the tax treaties. Once ready, an AI agent will be sent through the simulator to identify the scenario that will result in minimum tax liability. Identifying the best tax scenario across countries may save multinational corporations, like Google, billions of dollars annually. Given the nature of the raw data and the domain of taxes (i.e., numbers), this is a promising ground to employ artificial intelligence towards a practical and beneficial purpose.Keywords: taxation, law, multinational, corporation
Procedia PDF Downloads 1983565 The Revival of Cultural Heritage through Social Space Upliftment: Case Study of the Walled City of Ajmer, India
Authors: Vaishali Sharma
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The research is an attempt to hunt a scientific and objective method to transform Ajmer's traditional walled city into a living cultural heritage space, exploring urban management methods to elevate local economy and social space in relation to specific cultural-based initiatives. Ajmer is among the oldest and religiously diverse settlements in Rajasthan, that has seen superimposed developments through the eras. With numerous agencies operating towards the development of the town core of Ajmer, it becomes essential to structure development changes in tune with the transformations and the existing heritage. The study was radio-controlled by the subsequent analysis question: What is the way to overcome the genetic social and economic stress inside the communities and revive public life? In order to create necessary interventions at the neighbourhood level, fifteen neighbourhoods were identified. Each of those was analyzed relatively on three major dimensions: Heritage, Social and Local Economy. Each dimension was further broken down into multiple sub-aspects for an overall and exhaustive understanding. The average median values of the responses were used to develop a color-coded matrix to represent the scores in an exceedingly structured quantified manner, moreover, linking it to the spatial structure. Respondent perceptions on numerous dimensions were additionally recorded, so that the proposals are inclusive in nature. The goals are targeted at Ajmer's traditional walled towns, which will make it easier for the community to regulate the rapid transformations and commercialization occurring within the space. The study recommends the necessity for accrued support in methods and policies from the non-public sector, businesses as well as local stakeholders. An expansion, revitalization and maintenance of the major business and heritage corridors, for an increased local and visitor experience, can produce an impetus for promotion of the intangible heritage, to spur the local economic processes, conservation of heritage precincts and upward development.Keywords: cultural heritage, economic revitalization, neighbourhoods in walled cities, social space, tangible and intangible heritage
Procedia PDF Downloads 1603564 A Cooperative Transmission Scheme Using Two Sources Based on OFDM System
Authors: Bit-Na Kwon, Dong-Hyun Ha, Hyoung-Kyu Song
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In wireless communication, space-time block code (STBC), cyclic delay diversity (CDD) and space-time cyclic delay diversity (STCDD) are used as the spatial diversity schemes and have been widely studied for the reliable communication. If these schemes are used, the communication system can obtain the improved performance. However, the quality of the system is degraded when the distance between a source and a destination is distant in wireless communication system. In this paper, the cooperative transmission scheme using two sources is proposed and improves the performance of the wireless communication system.Keywords: OFDM, Cooperative communication, CDD, STBC, STCDD
Procedia PDF Downloads 4683563 Space Weather and Earthquakes: A Case Study of Solar Flare X9.3 Class on September 6, 2017
Authors: Viktor Novikov, Yuri Ruzhin
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The studies completed to-date on a relation of the Earth's seismicity and solar processes provide the fuzzy and contradictory results. For verification of an idea that solar flares can trigger earthquakes, we have analyzed a case of a powerful surge of solar flash activity early in September 2017 during approaching the minimum of 24th solar cycle was accompanied by significant disturbances of space weather. On September 6, 2017, a group of sunspots AR2673 generated a large solar flare of X9.3 class, the strongest flare over the past twelve years. Its explosion produced a coronal mass ejection partially directed towards the Earth. We carried out a statistical analysis of the catalogs of earthquakes USGS and EMSC for determination of the effect of solar flares on global seismic activity. New evidence of earthquake triggering due to the Sun-Earth interaction has been demonstrated by simple comparison of behavior of Earth's seismicity before and after the strong solar flare. The global number of earthquakes with magnitude of 2.5 to 5.5 within 11 days after the solar flare has increased by 30 to 100%. A possibility of electric/electromagnetic triggering of earthquake due to space weather disturbances is supported by results of field and laboratory studies, where the earthquakes (both natural and laboratory) were initiated by injection of electrical current into the Earth crust. For the specific case of artificial electric earthquake triggering the current density at a depth of earthquake, sources are comparable with estimations of a density of telluric currents induced by variation of space weather conditions due to solar flares. Acknowledgment: The work was supported by RFBR grant No. 18-05-00255.Keywords: solar flare, earthquake activity, earthquake triggering, solar-terrestrial relations
Procedia PDF Downloads 1433562 Research on Road Openness in the Old Urban Residential District Based on Space Syntax: A Case Study on Kunming within the First Loop Road
Authors: Haoyang Liang, Dandong Ge
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With the rapid development of Chinese cities, traffic congestion has become more and more serious. At the same time, there are many closed old residential area in Chinese cities, which seriously affect the connectivity of urban roads and reduce the density of urban road networks. After reopening the restricted old residential area, the internal roads in the original residential area were transformed into urban roads, which was of great help to alleviate traffic congestion. This paper uses the spatial syntactic theory to analyze the urban road network and compares the roads with the integration and connectivity degree to evaluate whether the opening of the roads in the residential areas can improve the urban traffic. Based on the road network system within the first loop road in Kunming, the Space Syntax evaluation model is established for status analysis. And comparative analysis method will be used to compare the change of the model before and after the road openness of the old urban residential district within the first-ring road in Kunming. Then it will pick out the areas which indicate a significant difference for the small dimensions model analysis. According to the analyzed results and traffic situation, the evaluation of road openness in the old urban residential district will be proposed to improve the urban residential districts.Keywords: Space Syntax, Kunming, urban renovation, traffic jam
Procedia PDF Downloads 1623561 Exploration of Slow-Traffic System Strategies for New Urban Areas Under the Integration of Industry and City - Taking Qianfeng District of Guang’an City as an Example
Authors: Qikai Guan
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With the deepening of China's urbanization process, the development of urban industry has entered a new period, due to the gradual compounding and diversification of urban industrial functions, urban planning has shifted from the previous single industrial space arrangement and functional design to focusing on the upgrading of the urban structure, and on the diversified needs of people. As an important part of urban activity space, ‘slow moving space’ is of great significance in alleviating urban traffic congestion, optimizing residents' travel experience and improving urban ecological space. Therefore, this paper takes the slow-moving transportation system under the perspective of industry-city integration as the starting point, through sorting out the development needs of the city in the process of industry-city integration, analyzing the characteristics of the site base, sorting out a series of compatibility between the layout of the new industrial zone and the urban slow-moving system, and integrating the design concepts. At the same time, through the analysis and summarization of domestic and international experience, the construction ideas are proposed. Finally, the following aspects of planning strategy optimization are proposed: industrial layout, urban vitality, ecological pattern, regional characteristics and landscape image. In terms of specific design, on the one hand, it builds a regional slow-moving network, puts forward a diversified design strategy for the industry-oriented and multi-functional composite central area, realizes the coexistence of pedestrian-oriented and multiple transportation modes, basically covers the public facilities, and enhances the vitality of the city. On the other hand, it improves the landscape ecosystem, creates a healthy, diversified and livable superline landscape system, helps the construction of the ‘green core’ of the central city, and improves the travel experience of the residents.Keywords: industry-city integration, slow-moving system, public space, functional integration
Procedia PDF Downloads 73560 Validity of Universe Structure Conception as Nested Vortexes
Authors: Khaled M. Nabil
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This paper introduces the Nested Vortexes conception of the universe structure and interprets all the physical phenomena according this conception. The paper first reviews recent physics theories, either in microscopic scale or macroscopic scale, to collect evidence that the space is not empty. But, these theories describe the property of the space medium without determining its structure. Determining the structure of space medium is essential to understand the mechanism that leads to its properties. Without determining the space medium structure, many phenomena; such as electric and magnetic fields, gravity, or wave-particle duality remain uninterpreted. Thus, this paper introduces a conception about the structure of the universe. It assumes that the universe is a medium of ultra-tiny homogeneous particles which are still undiscovered. Like any medium with certain movements, possibly because of a great asymmetric explosion, vortexes have occurred. A vortex condenses the ultra-tiny particles in its center forming a bigger particle, the bigger particles, in turn, could be trapped in a bigger vortex and condense in its center forming a much bigger particle and so on. This conception describes galaxies, stars, protons as particles at different levels. Existing of the particle’s vortexes make the consistency of the speed of light postulate is not true. This conception shows that the vortex motion dynamic agrees with the motion of all the universe particles at any level. An experiment has been carried out to detect the orbiting effect of aggregated vortexes of aligned atoms of a permanent magnet. Based on the described particle’s structure, the gravity force of a particle and attraction between particles as well as charge, electric and magnetic fields and quantum mechanics characteristics are interpreted. All augmented physics phenomena are solved.Keywords: astrophysics, cosmology, particles’ structure model, particles’ forces
Procedia PDF Downloads 1193559 B Spline Finite Element Method for Drifted Space Fractional Tempered Diffusion Equation
Authors: Ayan Chakraborty, BV. Rathish Kumar
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Off-late many models in viscoelasticity, signal processing or anomalous diffusion equations are formulated in fractional calculus. Tempered fractional calculus is the generalization of fractional calculus and in the last few years several important partial differential equations occurring in the different field of science have been reconsidered in this term like diffusion wave equations, Schr$\ddot{o}$dinger equation and so on. In the present paper, a time-dependent tempered fractional diffusion equation of order $\gamma \in (0,1)$ with forcing function is considered. Existence, uniqueness, stability, and regularity of the solution has been proved. Crank-Nicolson discretization is used in the time direction. B spline finite element approximation is implemented. Generally, B-splines basis are useful for representing the geometry of a finite element model, interfacing a finite element analysis program. By utilizing this technique a priori space-time estimate in finite element analysis has been derived and we proved that the convergent order is $\mathcal{O}(h²+T²)$ where $h$ is the space step size and $T$ is the time. A couple of numerical examples have been presented to confirm the accuracy of theoretical results. Finally, we conclude that the studied method is useful for solving tempered fractional diffusion equations.Keywords: B-spline finite element, error estimates, Gronwall's lemma, stability, tempered fractional
Procedia PDF Downloads 1923558 A Tuning Method for Microwave Filter via Complex Neural Network and Improved Space Mapping
Authors: Shengbiao Wu, Weihua Cao, Min Wu, Can Liu
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This paper presents an intelligent tuning method of microwave filter based on complex neural network and improved space mapping. The tuning process consists of two stages: the initial tuning and the fine tuning. At the beginning of the tuning, the return loss of the filter is transferred to the passband via the error of phase. During the fine tuning, the phase shift caused by the transmission line and the higher order mode is removed by the curve fitting. Then, an Cauchy method based on the admittance parameter (Y-parameter) is used to extract the coupling matrix. The influence of the resonant cavity loss is eliminated during the parameter extraction process. By using processed data pairs (the amount of screw variation and the variation of the coupling matrix), a tuning model is established by the complex neural network. In view of the improved space mapping algorithm, the mapping relationship between the actual model and the ideal model is established, and the amplitude and direction of the tuning is constantly updated. Finally, the tuning experiment of the eight order coaxial cavity filter shows that the proposed method has a good effect in tuning time and tuning precision.Keywords: microwave filter, scattering parameter, coupling matrix, intelligent tuning
Procedia PDF Downloads 3113557 Hardware-In-The-Loop Relative Motion Control: Theory, Simulation and Experimentation
Authors: O. B. Iskender, K. V. Ling, V. Dubanchet, L. Simonini
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This paper presents a Guidance and Control (G&C) strategy to address spacecraft maneuvering problem for future Rendezvous and Docking (RVD) missions. The proposed strategy allows safe and propellant efficient trajectories for space servicing missions including tasks such as approaching, inspecting and capturing. This work provides the validation test results of the G&C laws using a Hardware-In-the-Loop (HIL) setup with two robotic mockups representing the chaser and the target spacecraft. Through this paper, the challenges of the relative motion control in space are first summarized, and in particular, the constraints imposed by the mission, spacecraft and, onboard processing capabilities. Second, the proposed algorithm is introduced by presenting the formulation of constrained Model Predictive Control (MPC) to optimize the fuel consumption and explicitly handle the physical and geometric constraints in the system, e.g. thruster or Line-Of-Sight (LOS) constraints. Additionally, the coupling between translational motion and rotational motion is addressed via dual quaternion based kinematic description and accordingly explained. The resulting convex optimization problem allows real-time implementation capability based on a detailed discussion on the computational time requirements and the obtained results with respect to the onboard computer and future trends of space processors capabilities. Finally, the performance of the algorithm is presented in the scope of a potential future mission and of the available equipment. The results also cover a comparison between the proposed algorithms with Linear–quadratic regulator (LQR) based control law to highlight the clear advantages of the MPC formulation.Keywords: autonomous vehicles, embedded optimization, real-time experiment, rendezvous and docking, space robotics
Procedia PDF Downloads 1243556 Atmospheric Transport Modeling of Radio-Xenon Detections Possibly Related to the Announced Nuclear Test in North Korea on February 12, 2013
Authors: Kobi Kutsher
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On February 12th 2013, monitoring stations of the Preparatory Commission of the Comprehensive Nuclear Test-Ban Treaty Organization (CTBTO) detected a seismic event with explosion-like underground characteristics in the Democratic People’s Republic of Korea (DPRK). The location was found to be in the vicinity of the two previous announced nuclear tests in 2006 and 2009.The nuclear test was also announced by the government of the DPRK.After an underground nuclear explosion, radioactive fission products (mostly noble gases) can seep through layers of rock and sediment until they escape into the atmosphere. The fission products are dispersed in the atmosphere and may be detected thousands of kilometers downwind from the test site. Indeed, more than 7 weeks after the explosion, unusual detections of noble gases was reported at the radionuclide station in Takasaki, Japan. The radionuclide station is a part of the International Monitoring System, operated to verify the CTBT. This study provides an estimation of the possible source region and the total radioactivity of the release using Atmospheric Transport Modeling.Keywords: atmospheric transport modeling, CTBTO, nuclear tests, radioactive fission products
Procedia PDF Downloads 4253555 Federal College of Education Kano
Authors: Mahnaz Babaei Morad, Mojtaba Zargarzadeh, Behnaz Babaei Morad, Najmeh Salari Nasab
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Green roofs and walls are one of the key elements of sustainable design in ecology design of cities. Lack of open space and urban green at different scales from one neighborhood to district is as subject that has become challenge for urban management Use change from green space to other use is familiar for Iranian citizens. The high price of land in this area, it seems only justified reason for municipalities that reduce the green space per capita. In this paper, examines the rooftops of Iranian city as a fifth facade, as well as the opportunity to offset some of the capital's urban spaces that has been removed. Today green roof isn't a matter of taste in the world. Be proportional to the quantity and quality of the architecture become the first concern of urban professionals and ecological approaches such as "sustainable" and "green architecture" is checked. In this paper we review and present examples of green roofs have been executed in Iran over the past decade. Survey some of the urban management policies in leading province in this article constitutes the second dimension. The purpose of this paper is study example of green roof performance in different parts of Iran, along with criteria for sustainable urban development and achieves the policies and components collection of implementation sustainable development , specific of Iranian green roof and monitor the develops ways to it.Keywords: sustainable development, green roofs, Iran, green architecture
Procedia PDF Downloads 4943554 Ontology for a Voice Transcription of OpenStreetMap Data: The Case of Space Apprehension by Visually Impaired Persons
Authors: Said Boularouk, Didier Josselin, Eitan Altman
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In this paper, we present a vocal ontology of OpenStreetMap data for the apprehension of space by visually impaired people. Indeed, the platform based on produsage gives a freedom to data producers to choose the descriptors of geocoded locations. Unfortunately, this freedom, called also folksonomy leads to complicate subsequent searches of data. We try to solve this issue in a simple but usable method to extract data from OSM databases in order to send them to visually impaired people using Text To Speech technology. We focus on how to help people suffering from visual disability to plan their itinerary, to comprehend a map by querying computer and getting information about surrounding environment in a mono-modal human-computer dialogue.Keywords: TTS, ontology, open street map, visually impaired
Procedia PDF Downloads 2953553 Annular Axi-Symmetric Stagnation Flow of Electrically Conducting Fluid on a Moving Cylinder in the Presence of Axial Magnetic Field
Authors: Deva Kanta Phukan
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An attempt is made where an electrically conducting fluid is injected from a fixed outer cylindrical casing onto an inner moving cylindrical rod. A magnetic field is applied parallel to the axis of the cylindrical rod. The basic governing set of partial differential equations for conservation of mass and momentum are reduced to a set of non-linear ordinary differential equation by introducing similarity transformation, which are integrated numerically. A perturbation solution for the case of large magnetic parameter is derived for constant Reynolds number.Keywords: annular axi-symmetric stagnation flow, conducting fluid, magnetic field, moving cylinder
Procedia PDF Downloads 4003552 Self-Tuning Robot Control Based on Subspace Identification
Authors: Mathias Marquardt, Peter Dünow, Sandra Baßler
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The paper describes the use of subspace based identification methods for auto tuning of a state space control system. The plant is an unstable but self balancing transport robot. Because of the unstable character of the process it has to be identified from closed loop input-output data. Based on the identified model a state space controller combined with an observer is calculated. The subspace identification algorithm and the controller design procedure is combined to a auto tuning method. The capability of the approach was verified in a simulation experiments under different process conditions.Keywords: auto tuning, balanced robot, closed loop identification, subspace identification
Procedia PDF Downloads 3803551 The Effect of Screw Parameters on Pullout Strength of Screw Fixation in Cervical Spine
Authors: S. Ritddech, P. Aroonjarattham, K. Aroonjarattham
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The pullout strength had an effect on the stability of plate screw fixation when inserted in the cervical spine. Nine different titanium alloy bone screws were used to test the pullout strength through finite element analysis. The result showed that the Moss Miami I can bear the highest pullout force at 1,075 N, which causes the maximum von Mises stress at 858.87 MPa, a value over the yield strength of titanium. The bone screw should have large outer diameter, core diameter and proximal root radius to increase the pullout strength.Keywords: pullout strength, screw parameter, cervical spine, finite element analysis
Procedia PDF Downloads 2923550 Anti-Gravity to Neo-Concretism: The Epodic Spaces of Non-Objective Art
Authors: Alexandra Kennedy
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Making use of the notion of ‘epodic spaces’ this paper presents a reconsideration of non-objective art practices, proposing alternatives to established materialist, formalist, process-based conceptualist approaches to such work. In his Neo-Concrete Manifesto (1959) Ferreira Gullar (1930-2016) sought to create a distinction between various forms of non-objective art. He distinguished the ‘geometric’ arts of neoplasticism, constructivism, and suprematism – which he described as ‘dangerously acute rationalism’ – from other non-objective practices. These alternatives, he proposed, have an expressive potential lacking in the former and this formed the basis for their categorisation as neo-concrete. Gullar prioritized the phenomenological over the rational, with an emphasis on the role of the spectator (a key concept of minimalism). Gullar highlighted the central role of sensual experience, colour and the poetic in such work. In the early twentieth century, Russian Cosmism – an esoteric philosophical movement – was highly influential on Russian avant-garde artists and can account for suprematist artists’ interest in, and approach to, planar geometry and four-dimensional space as demonstrated in the abstract paintings of Kasimir Malevich (1879-1935). Nikolai Fyodorov (1823-1903) promoted the idea of anti-gravity and cosmic space as the field for artistic activity. The artist and writer Kuzma Petrov-Vodkin (1878-1939) wrote on the concept of Euclidean space, the overcoming of such rational conceptions of space and the breaking free from the gravitational field and the earth’s sphere. These imaginary spaces, which also invoke a bodily experience, present a poetic dimension to the work of the suprematists. It is a dimension that arguably aligns more with Gullar’s formulation of his neo-concrete rather than that of his alignment of Suprematism with rationalism. While found in experiments with planar geometry, the interest in forms suggestive of an experience of breaking free–both physically from the earth and conceptually from rational, mathematical space (in a pre-occupation with non-Euclidean space and anti-geometry) and in their engagement with the spatial properties of colour, Suprematism presents itself as imaginatively epodic. The paper discusses both historical and contemporary non-objective practices in this context, drawing attention to the manner in which the category of the non-objective is used to categorise art works which are, arguably, qualitatively different.Keywords: anti-gravity, neo-concrete, non-Euclidian geometry, non-objective painting
Procedia PDF Downloads 1773549 Proton Irradiation Testing on Commercial Enhancement Mode GaN Power Transistor
Authors: L. Boyaci
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Two basic equipment of electrical power subsystem of space satellites are Power Conditioning Unit (PCU) and Power Distribution Unit (PDU). Today, the main switching element used in power equipment in satellites is silicon (Si) based radiation-hardened MOSFET. GaNFETs have superior performances over MOSFETs in terms of their conduction and switching characteristics. GaNFET has started to take MOSFET’s place in many applications in industry especially by virtue of its switching performances. If GaNFET can also be used in equipment for space applications, this would be great revolution for future space power subsystem designs. In this study, the effect of proton irradiation on Gallium Nitride based power transistors was investigated. Four commercial enhancement mode GaN power transistors from Efficient Power Conversion Corporation (EPC) are irradiated with 30MeV protons while devices are switching. Flux of 8.2x10⁹ protons/cm²/s is applied for 12.5 seconds to reach ultimate fluence of 10¹¹ protons/cm². Vgs-Ids characteristics are measured and recorded for each device before, during and after irradiation. It was observed that if there would be destructive events. Proton induced permanent damage on devices is not observed. All the devices remained healthy and continued to operate. For two of these devices, further irradiation is applied with same flux for 30 minutes up to a total fluence level of 1.476x10¹³ protons/cm². We observed that GaNFETs are fully functional under this high level of radiation and no destructive events and irreversible failures took place for transistors. Results reveal that irradiated GaNFET in this experiment has radiation tolerance under proton testing and very important candidate for being one of the future power switching element in space.Keywords: enhancement mode GaN power transistors, proton irradiation effects, radiation tolerance
Procedia PDF Downloads 1523548 Numerical Modeling of Various Support Systems to Stabilize Deep Excavations
Authors: M. Abdallah
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Urban development requires deep excavations near buildings and other structures. Deep excavation has become more a necessity for better utilization of space as the population of the world has dramatically increased. In Lebanon, some urban areas are very crowded and lack spaces for new buildings and underground projects, which makes the usage of underground space indispensable. In this paper, a numerical modeling is performed using the finite element method to study the deep excavation-diaphragm wall soil-structure interaction in the case of nonlinear soil behavior. The study is focused on a comparison of the results obtained using different support systems. Furthermore, a parametric study is performed according to the remoteness of the structure.Keywords: deep excavation, ground anchors, interaction soil-structure, struts
Procedia PDF Downloads 4143547 Biocompatible Porous Titanium Scaffolds Produced Using a Novel Space Holder Technique
Authors: Yunhui Chen, Damon Kent, Matthew Dargusch
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Synthetic scaffolds are a highly promising new approach to replace both autografts and allografts to repair and remodel damaged bone tissue. Biocompatible porous titanium scaffold was manufactured through a powder metallurgy approach. Magnesium powder was used as space holder material which was compacted with titanium powder and removed during sintering. Evaluation of the porosity and mechanical properties showed a high level of compatibility with human bone. Interconnectivity between pores is higher than 95% for porosity as low as 30%. The elastic moduli are 39 GPa, 16 GPa and 9 GPa for 30%, 40% and 50% porosity samples which match well to that of natural bone (4-30 GPa). The yield strengths for 30% and 40% porosity samples of 315 MPa and 175 MPa are superior to that of human bone (130-180 MPa). In-vitro cell culture tests on the scaffold samples using Human Mesenchymal Stem Cells (hMSCs) demonstrated their biocompatibility and indicated osseointegration potential. The scaffolds allowed cells to adhere and spread both on the surface and inside the pore structures. With increasing levels of porosity/interconnectivity, improved cell proliferation is obtained within the pores. It is concluded that samples with 30% porosity exhibit the best biocompatibility. The results suggest that porous titanium scaffolds generated using this manufacturing route have excellent potential for hard tissue engineering applications.Keywords: scaffolds, MG-63 cell culture, titanium, space holder
Procedia PDF Downloads 2353546 Temperature Control and Comfort Level of Elementary School Building with Green Roof in New Taipei City, Taiwan
Authors: Ying-Ming Su, Mei-Shu Huang
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To mitigate the urban heat island effect has become a global issue facing the challenge of climate change. Through literature reviews, plant photosynthesis can reduce the carbon dioxide and mitigate the urban heat island effect relatively. Because there are not enough open space and park, green roof has become an important policy in Taiwan. We selected elementary school buildings in northern New Taipei City as research subjects since elementary school is asked priority to build green roof and important educational place to promote green roof concept. Testo 175-H1 recording device was used to record the temperature and humidity difference between roof surface and interior space below roof with and without green roof for the long-term. We also use questionnaire to investigate the awareness of comfort level of green roof and sensation of teachers and students of the elementary school. The results indicated the temperature of roof without greening was higher than that with greening about 2°C. But sometimes during noontime, the temperature of green roof was higher than that of non-green roof related to the character of the accumulation and dissipation of heat of greening probably. The temperature of interior space below green roof was normally lower than that without green roof about 1°C showed that green roof could lower the temperature. The humidity of the green roof was higher than the one without greening also indicated that green roof retained water better. Teachers liked to combine green roof concept in the curriculum, students wished all classes can take turns to maintain the green roof. Teachers and students that school had integrated green roof concept in the curriculum were more willing to participate in the maintenance work of green roof. Teachers and students who may access and touch the green roof can be more aware of the green roof benefit. We suggest architect to increase the accessibility and visibility of green roof, such as a part of the activity space. This idea can be a reference of the green roof curriculum design.Keywords: comfort level, elementary school, green roof, heat island effect
Procedia PDF Downloads 4163545 A Comparative Analysis of Multicarrier SPWM Strategies for Five-Level Flying Capacitor Inverter
Authors: Bachir Belmadani, Rachid Taleb, Zinelaabidine Boudjema, Adil Yahdou
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Carrier-based methods have been used widely for switching of multilevel inverters due to their simplicity, flexibility and reduced computational requirements compared to space vector modulation (SVM). This paper focuses on Multicarrier Sinusoidal Pulse Width Modulation (MCSPWM) strategy for the three phase Five-Level Flying Capacitor Inverter (5LFCI). The inverter is simulated for Induction Motor (IM) load and Total Harmonic Distortion (THD) for output waveforms is observed for different controlling schemes.Keywords: flying capacitor inverter, multicarrier sinusoidal pulse width modulation, space vector modulation, total harmonic distortion, induction motor
Procedia PDF Downloads 4103544 Childhood Warscape, Experiences from Children of War Offer Key Design Decisions for Safer Built Environments
Authors: Soleen Karim, Meira Yasin, Rezhin Qader
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Children’s books present a colorful life for kids around the world, their current environment or what they could potentially have- a home, two loving parents, a playground, and a safe school within a short walk or bus ride. These images are only pages in a donated book for children displaced by war. The environment they live in is significantly different. Displaced children are faced with a temporary life style filled with fear and uncertainty. Children of war associate various structural institutions with a trauma and cannot enter the space, even if it is for their own future development, such as a school. This paper is a collaborative effort with students of the Kennesaw State University architecture department, architectural designers and a mental health professional to address and link the design challenges and the psychological trauma for children of war. The research process consists of a) interviews with former refugees, b) interviews with current refugee children, c) personal understanding of space through one’s own childhood, d) literature review of tested design methods to address various traumas. Conclusion: In addressing the built environment for children of war, it is necessary to address mental health and well being through the creation of space that is sensitive to the needs of children. This is achieved by understanding critical design cues to evoke normalcy and safe space through program organization, color, and symbiosis of synthetic and natural environments. By involving the children suffering from trauma in the design process, aspects of the design are directly enhanced to serve the occupant. Neglecting to involve the participants creates a nonlinear design outcome and does not serve the needs of the occupant to afford them equal opportunity learning and growth experience as other children around the world.Keywords: activist architecture, childhood education, childhood psychology, adverse childhood experiences
Procedia PDF Downloads 1393543 Redefining "Dedhee" in Terms of Knowledge Gathering and Conserving Hazara Literature
Authors: Urooj Shafique, Salman Jamil
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In the context of an urban human life, city requires to meeting some standards which, at a glance are called the standards of a quality life. Measuring the quality of life according to particular social, economic and cultural conditions of a country and also the emphasis of a country twenty years visions on this issue has special importance. Cultural gathering spaces improve social and economic vitality on one side and on the other side provide favorable conditions for citizen leisure. But unfortunately these cultural gathering spaces in our society are losing their meaning and importance with time. Like coffee houses and libraries. Dedhee was the most prominent place among the cultural gathering spaces in Hazara division. People used to visit them in order to get something out of these spaces. At present they lie in our cities as places of no interest. Libraries are converted into storage houses where books lie untouched for years and years. The aim of my project is to create unique space that engage community members in the learning and creation process, where people can share their knowledge with others as well as enjoy their personal space. The spaces are flexible enough to accommodate people of different moods and interests, with the purpose of helping communities to become aware of their own cultures and to be socially engaged. The site for this specific project has been selected near Cantonment Park Abbottabad, Pakistan. The city of Abbottabad is famous for its writers, poets and storytellers. The site is selected next to the Cantonment Park, at a central location in the whole city so that it can attract users from almost every point of the city. The project provides a cultural gathering space for the people of the city where they can sit and discuss their ideas within a creative and expressive environment, which can represent the cultures of a community.Keywords: cultural gathering space, Dedhee, Hazara literature, intellectuals’ hub
Procedia PDF Downloads 3923542 Exploring the Growth Path under Coupling Relationship between Space and Economy of Mountain Village and Townlets: Case Study of Southwest China
Authors: Runlin Liu, Shilong Li
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China is a mountainous country, with two-thirds of its territory covered by plateaus, hills, and mountains, and nearly half of the cities and towns are distributed in mountainous areas. Compared with the environmental constraints in the development path of cities and towns in the plains, there are heterogeneities in aspects such as spatial characteristics, growth mode, and ecological protection and so on for mountain village and townlets, and the development path of mountain village and townlets has a bidirectional relationship between mountain space and economic growth. Based on classical growth theory, this article explores the two-dimensional coupling relation between space and economy in mountain village and townlets under background of rural rejuvenation. GIS technology is adopted in the study to analyze spatial trends and patterns, economical spatial differentiation characteristics of village and townlets. This powerful tool can also help differentiate and analyze limiting factors and assessment systems in the economic growth of village and townlets under spatial dimension of mountainous space. To make the research more specific, this article selects mountain village and townlets in Southwest China as the object of study; this provides good cases for analyzing parallel coupling mechanism of the duality structure system between economic growth and spatial expansion and discussing the path selection of spatial economic growth of mountain village and towns with multiple constraints. The research results can provide quantitative references for the spatial and economic development paths of mountain villages and towns, which is helpful in realizing efficient and high-quality development mode with equal emphasis on spatial and economic benefits for these type of towns.Keywords: coupling mechanism, geographic information technology, mountainous town, synergetic development, spatial economy
Procedia PDF Downloads 1503541 Performance Demonstration of Extendable NSPO Space-Borne GPS Receiver
Authors: Hung-Yuan Chang, Wen-Lung Chiang, Kuo-Liang Wu, Chen-Tsung Lin
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National Space Organization (NSPO) has completed in 2014 the development of a space-borne GPS receiver, including design, manufacture, comprehensive functional test, environmental qualification test and so on. The main performance of this receiver include 8-meter positioning accuracy, 0.05 m/sec speed-accuracy, the longest 90 seconds of cold start time, and up to 15g high dynamic scenario. The receiver will be integrated in the autonomous FORMOSAT-7 NSPO-Built satellite scheduled to be launched in 2019 to execute pre-defined scientific missions. The flight model of this receiver manufactured in early 2015 will pass comprehensive functional tests and environmental acceptance tests, etc., which are expected to be completed by the end of 2015. The space-borne GPS receiver is a pure software design in which all GPS baseband signal processing are executed by a digital signal processor (DSP), currently only 50% of its throughput being used. In response to the booming global navigation satellite systems, NSPO will gradually expand this receiver to become a multi-mode, multi-band, high-precision navigation receiver, and even a science payload, such as the reflectometry receiver of a global navigation satellite system. The fundamental purpose of this extension study is to port some software algorithms such as signal acquisition and correlation, reused code and large amount of computation load to the FPGA whose processor is responsible for operational control, navigation solution, and orbit propagation and so on. Due to the development and evolution of the FPGA is pretty fast, the new system architecture upgraded via an FPGA should be able to achieve the goal of being a multi-mode, multi-band high-precision navigation receiver, or scientific receiver. Finally, the results of tests show that the new system architecture not only retains the original overall performance, but also sets aside more resources available for future expansion possibility. This paper will explain the detailed DSP/FPGA architecture, development, test results, and the goals of next development stage of this receiver.Keywords: space-borne, GPS receiver, DSP, FPGA, multi-mode multi-band
Procedia PDF Downloads 3693540 Temporal Axis in Japanese: The Paradox of a Metaphorical Orientation in Time
Authors: Tomoko Usui
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In the field of linguistics, it has been said that concepts associated with space and motion systematically contribute structure to the temporal concept. This is the conceptual metaphor theory. conceptual metaphors typically employ a more abstract concept (time) as their target and a more concrete or physical concept as their source (space). This paper will examine two major temporal conceptual metaphors: Ego-centered Moving Time Metaphor and Time-RP Metaphor. Moving time generally receives a front-back orientation, however, Japanese shows a different orientation given to time. By means of Ego perspective, this paper will illustrate the paradox of a metaphorical orientation in time.Keywords: Ego-centered Moving Time Metaphor, Japanese saki, temporal metaphors, Time RP Metaphor
Procedia PDF Downloads 496