Search results for: system testing.
6075 Applicability of Linearized Model of Synchronous Generator for Power System Stability Analysis
Authors: J. Ritonja, B. Grcar
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For the synchronous generator simulation and analysis and for the power system stabilizer design and synthesis a mathematical model of synchronous generator is needed. The model has to accurately describe dynamics of oscillations, while at the same time has to be transparent enough for an analysis and sufficiently simplified for design of control system. To study the oscillations of the synchronous generator against to the rest of the power system, the model of the synchronous machine connected to an infinite bus through a transmission line having resistance and inductance is needed. In this paper, the linearized reduced order dynamic model of the synchronous generator connected to the infinite bus is presented and analysed in details. This model accurately describes dynamics of the synchronous generator only in a small vicinity of an equilibrium state. With the digression from the selected equilibrium point the accuracy of this model is decreasing considerably. In this paper, the equations’ descriptions and the parameters’ determinations for the linearized reduced order mathematical model of the synchronous generator are explained and summarized and represent the useful origin for works in the areas of synchronous generators’ dynamic behaviour analysis and synchronous generator’s control systems design and synthesis. The main contribution of this paper represents the detailed analysis of the accuracy of the linearized reduced order dynamic model in the entire synchronous generator’s operating range. Borders of the areas where the linearized reduced order mathematical model represents accurate description of the synchronous generator’s dynamics are determined with the systemic numerical analysis. The thorough eigenvalue analysis of the linearized models in the entire operating range is performed. In the paper, the parameters of the linearized reduced order dynamic model of the laboratory salient poles synchronous generator were determined and used for the analysis. The theoretical conclusions were confirmed with the agreement of experimental and simulation results.
Keywords: Eigenvalue analysis, mathematical model, power system stability, synchronous generator.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15896074 Risk Assessment for Aerial Package Delivery
Authors: Haluk Eren, Ümit Çelik
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Recent developments in unmanned aerial vehicles (UAVs) have begun to attract intense interest. UAVs started to use for many different applications from military to civilian use. Some online retailer and logistics companies are testing the UAV delivery. UAVs have great potentials to reduce cost and time of deliveries and responding to emergencies in a short time. Despite these great positive sides, just a few works have been done for routing of UAVs for package deliveries. As known, transportation of goods from one place to another may have many hazards on delivery route due to falling hazards that can be exemplified as ground objects or air obstacles. This situation refers to wide-range insurance concept. For this reason, deliveries that are made with drones get into the scope of shipping insurance. On the other hand, air traffic was taken into account in the absence of unmanned aerial vehicle. But now, it has been a reality for aerial fields. In this study, the main goal is to conduct risk analysis of package delivery services using drone, based on delivery routes.
Keywords: Drone risk assessment, drone package delivery.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19496073 Investments Attractiveness via Combinatorial Optimization Ranking
Authors: Ivan C. Mustakerov, Daniela I. Borissova
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The paper proposes an approach to ranking a set of potential countries to invest taking into account the investor point of view about importance of different economic indicators. For the goal, a ranking algorithm that contributes to rational decision making is proposed. The described algorithm is based on combinatorial optimization modeling and repeated multi-criteria tasks solution. The final result is list of countries ranked in respect of investor preferences about importance of economic indicators for investment attractiveness. Different scenarios are simulated conforming to different investors preferences. A numerical example with real dataset of indicators is solved. The numerical testing shows the applicability of the described algorithm. The proposed approach can be used with any sets of indicators as ranking criteria reflecting different points of view of investors.
Keywords: Combinatorial optimization modeling, economics investment attractiveness, economics ranking algorithm, multi-criteria problems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21056072 The Shanghai Cooperation Organization: China's Grand Strategy in Central Asia
Authors: Mara Gubaidullina, Aigerim Yelibayeva
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The Shanghai Cooperation Organization is one of the successful outcomes of China's foreign policy since the end of the Cold war. The expansion of multilateral ties all over the world by dint of pursuing institutional strategies as SCO, identify China as a more constructive power. SCO became a new model of cooperation that was formed on remains of collapsed Soviet system, and predetermined China's geopolitical role in the region. As the fast developing effective regional mechanism, SCO today has more of external impact on the international system and forms a new type of interaction for promoting China's grand strategy of 'peaceful rise'.
Keywords: Central Asia, China's grand strategy, Shanghai Cooperation Organization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20036071 Choosing R-tree or Quadtree Spatial DataIndexing in One Oracle Spatial Database System to Make Faster Showing Geographical Map in Mobile Geographical Information System Technology
Authors: Maruto Masserie Sardadi, Mohd Shafry bin Mohd Rahim, Zahabidin Jupri, Daut bin Daman
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The latest Geographic Information System (GIS) technology makes it possible to administer the spatial components of daily “business object," in the corporate database, and apply suitable geographic analysis efficiently in a desktop-focused application. We can use wireless internet technology for transfer process in spatial data from server to client or vice versa. However, the problem in wireless Internet is system bottlenecks that can make the process of transferring data not efficient. The reason is large amount of spatial data. Optimization in the process of transferring and retrieving data, however, is an essential issue that must be considered. Appropriate decision to choose between R-tree and Quadtree spatial data indexing method can optimize the process. With the rapid proliferation of these databases in the past decade, extensive research has been conducted on the design of efficient data structures to enable fast spatial searching. Commercial database vendors like Oracle have also started implementing these spatial indexing to cater to the large and diverse GIS. This paper focuses on the decisions to choose R-tree and quadtree spatial indexing using Oracle spatial database in mobile GIS application. From our research condition, the result of using Quadtree and R-tree spatial data indexing method in one single spatial database can save the time until 42.5%.Keywords: Indexing, Mobile GIS, MapViewer, Oracle SpatialDatabase.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 40346070 Broadcasting Stabilization for Dynamical Multi-Agent Systems
Authors: Myung-Gon Yoon, Jung-Ho Moon, Tae Kwon Ha
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This paper deals with a stabilization problem for multi-agent systems, when all agents in a multi-agent system receive the same broadcasting control signal and the controller can measure not each agent output but the sum of all agent outputs. It is analytically shown that when the sum of all agent outputs is bounded with a certain broadcasting controller for a given reference, each agent output is separately bounded: stabilization of the sum of agent outputs always results in the stability of every agent output. A numerical example is presented to illustrate our theoretic findings in this paper.
Keywords: Broadcasting Control, Multi-agent System, Transfer Function
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18396069 Periodic Solutions for a Food Chain System with Monod–Haldane Functional Response on Time Scales
Authors: Kejun Zhuang, Hailong Zhu
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In this paper, the three species food chain model on time scales is established. The Monod–Haldane functional response and time delay are considered. With the help of coincidence degree theory, existence of periodic solutions is investigated, which unifies the continuous and discrete analogies.
Keywords: Food chain system, periodic solution, time scales, coincidence degree.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 84696068 Nonlinear Acoustic Echo Cancellation Using Volterra Filtering with a Variable Step-Size GS-PAP Algorithm
Authors: J. B. Seo, K. J. Kim, S. W. Nam
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In this paper, a nonlinear acoustic echo cancellation (AEC) system is proposed, whereby 3rd order Volterra filtering is utilized along with a variable step-size Gauss-Seidel pseudo affine projection (VSSGS-PAP) algorithm. In particular, the proposed nonlinear AEC system is developed by considering a double-talk situation with near-end signal variation. Simulation results demonstrate that the proposed approach yields better nonlinear AEC performance than conventional approaches.Keywords: Acoustic echo cancellation (AEC), Volterra filtering, variable step-size, GS-PAP.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18136067 SATA: A Web Based Scheduling Support System
Authors: Rajeswari Raju, Saiful Nizam Warris, Hazlifah Mohd Rusli
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Developing a university course schedule is difficult. This is due to the limitations in the resources available. The process is made even harder with different faculties or departments having different ways of stating their schedule requirements. The person in charge of taking the schedule requirements and turning them into a proper course schedule is not only burden with the task of allocating the appropriate classes and time to lecturers and students, they also need to understand the schedule requirements. Therefore a scheduling support system named SATA is developed to assist ICRESS in the course scheduling process. SATA has been put to use for several semesters and the results have been encouraging. It won a bronze medal in the 2008 Invention, Innovation and Design competition (IID-08) and has been submitted to be patented in October 2008Keywords: Course Scheduling, Scheduling Tool Aid.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15726066 Real-Time Testing of Steel Strip Welds based on Bayesian Decision Theory
Authors: Julio Molleda, Daniel F. García, Juan C. Granda, Francisco J. Suárez
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One of the main trouble in a steel strip manufacturing line is the breakage of whatever weld carried out between steel coils, that are used to produce the continuous strip to be processed. A weld breakage results in a several hours stop of the manufacturing line. In this process the damages caused by the breakage must be repaired. After the reparation and in order to go on with the production it will be necessary a restarting process of the line. For minimizing this problem, a human operator must inspect visually and manually each weld in order to avoid its breakage during the manufacturing process. The work presented in this paper is based on the Bayesian decision theory and it presents an approach to detect, on real-time, steel strip defective welds. This approach is based on quantifying the tradeoffs between various classification decisions using probability and the costs that accompany such decisions.Keywords: Classification, Pattern Recognition, ProbabilisticReasoning, Statistical Data Analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14086065 Computational Study of Improving the Efficiency of Photovoltaic Panels in the UAE
Authors: Ben Richard Hughes, Ng Ping Sze Cherisa, Osman Beg
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Various solar energy technologies exist and they have different application techniques in the generation of electrical power. The widespread use of photovoltaic (PV) modules in such technologies has been limited by relatively high costs and low efficiencies. The efficiency of PV panels decreases as the operating temperatures increase. This is due to the affect of solar intensity and ambient temperature. In this work, Computational Fluid Dynamics (CFD) was used to model the heat transfer from a standard PV panel and thus determine the rate of dissipation of heat. To accurately model the specific climatic conditions of the United Arab Emirates (UAE), a case study of a new build green building in Dubai was used. A finned heat pipe arrangement is proposed and analyzed to determine the improved heat dissipation and thus improved performance efficiency of the PV panel. A prototype of the arrangement is built for experimental testing to validate the CFD modeling and proof of concept.Keywords: Computational Fluid Dynamics, Improving Efficiency, Photovoltaic (PV) Panels, Heat-pipe
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 34906064 Experimental Determination of the Critical Locus of the Acetone + Chloroform Binary System
Authors: Niramol Juntarachat, Romain Privat, Jean-Noël Jaubert
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In this paper, vapour-liquid critical locus for the binary system acetone + chloroform was determined experimentally over the whole range of composition. The critical property measurements were carried out using a dynamic-synthetic apparatus, employed in the dynamic mode. The critical points are visually determined by observing the critical opalescence and the simultaneous disappearance and reappearance of the meniscus in the middle of a high-pressure view cell which withstands operations up to 673K and 20MPa. The experimental critical points measured in this work were compared to those available in literature.Keywords: Experimental measurement, critical point, critical locus, negative azeotrope.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24336063 Analysis and Prototyping of Biological Systems: the Abstract Biological Process Model
Authors: Antonio Di Leva, Roberto Berchi, Gianpiero Pescarmona, Michele Sonnessa
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The aim of a biological model is to understand the integrated structure and behavior of complex biological systems as a function of the underlying molecular networks to achieve simulation and forecast of their operation. Although several approaches have been introduced to take into account structural and environment related features, relatively little attention has been given to represent the behavior of biological systems. The Abstract Biological Process (ABP) model illustrated in this paper is an object-oriented model based on UML (the standard object-oriented language). Its main objective is to bring into focus the functional aspects of the biological system under analysis.Keywords: Biological processes, system dynamics, systemmodeling, UML.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16396062 Internal Leakage Analysis from Pd to Pc Port Direction in ECV Body Used in External Variable Type A/C Compressor
Authors: Md. Iqbal Mahmud, Haeng Muk Cho, Seo Hyun Sang, Wang Wen Hai, Chang Heon Yi, Man Ik Hwang, Dae Hoon Kang
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Solenoid operated electromagnetic control valve (ECV) playing an important role for car’s air conditioning control system. ECV is used in external variable displacement swash plate type compressor and controls the entire air conditioning system by means of a pulse width modulation (PWM) input signal supplying from an external source (controller). Complete form of ECV contains number of internal features like valve body, core, valve guide, plunger, guide pin, plunger spring, bellows etc. While designing the ECV; dimensions of different internal items must meet the standard requirements as it is quite challenging. In this research paper, especially the dimensioning of ECV body and its three pressure ports through which the air/refrigerant passes are considered. Here internal leakage test analysis of ECV body is being carried out from its discharge port (Pd) to crankcase port (Pc) when the guide valve is placed inside it. The experiments have made both in ordinary and digital system using different assumptions and thereafter compare the results.
Keywords: Electromagnetic control valve (ECV), Leakage, Pressure port, Valve body, Valve guide.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28526061 Relational Framework and its Applications
Authors: Lidia Obojska
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This paper has, as its point of departure, the foundational axiomatic theory of E. De Giorgi (1996, Scuola Normale Superiore di Pisa, Preprints di Matematica 26, 1), based on two primitive notions of quality and relation. With the introduction of a unary relation, we develop a system totally based on the sole primitive notion of relation. Such a modification enables a definition of the concept of dynamic unary relation. In this way we construct a simple language capable to express other well known theories such as Robinson-s arithmetic or a piece of a theory of concatenation. A key role in this system plays an abstract relation designated by “( )", which can be interpreted in different ways, but in this paper we will focus on the case when we can perform computations and obtain results.Keywords: language, unary relations, arithmetic, computability
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12586060 Influence of Electrolytes and High Viscosity on Liquid-Liquid Separation
Authors: K. Anusarn, P. Chuttrakul, M. Schmidt, T. Kangsadan, A. Pfennig
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Liquid-liquid extraction is a process using two immiscible liquids to extract compounds from one phase without high temperature requirement. Mostly, the technical implementation of this process is carried out in mixer-settlers or extraction columns. In real chemical processes, chemicals may have high viscosity and contain impurities. These impurities may change the settling behavior of the process without measurably changing the physical properties of the phases. In the current study, the settling behavior and the affected parameters in a high-viscosity system were observed. Batchsettling experiments were performed to experimentally quantify the settling behavior and the mixer-settler model of Henschke [1] was used to evaluate the behavior of the toluene + water system. The viscosity of the system was increased by adding polyethylene glycol 4000 to the aqueous phase. NaCl and Na2SO4 were used to study the influence of electrolytes. The results from this study show that increasing the viscosity of water has a higher influence on the settling behavior in comparison to the effects of the electrolytes. It can be seen from the experiments that at high salt concentrations, there was no effect on the settling behavior.Keywords: Coalescence; electrolytes; liquid-liquid separation; high viscosity; mixer- settler.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22216059 Comparison of Frequency Converter Outages: A Case Study on the Swedish TPS System
Authors: Y. A. Mahmood, A. Ahmadi, R. Karim, U. Kumar, A.K. Verma, N. Fransson
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The purpose of this paper isunavailability of the two main types of conveSwedish traction power supply (TPS) system, i.e.static converter. The number of outages and the ouused to analyze and compare the unavailability oconverters. The mean cumulative function (MCF)analyze the number of outages and the unavailabthe forced outage rate (FOR) concept has been uoutage rates. The study shows that the outagesfailure occur at a constant rate by calendar timconverter stations, while very few stations havedecreasing rate. It has also been found that the stata higher number of outages and a higher outage ratcompared to the rotary converter types. The resultsthat combining the number of outages and the fgives a better view of the converters performasupport for the maintenance decision. In fact, usingdoes not reflect reality. Comparing these two indein identifying the areas where extra resources are maintenance planning and where improvementsoutage in the TPS system.KeywordsFrequency Converter, Forced OuCumulative Function, Traction Power Supply, ESystems.
Keywords: Frequency Converter, Forced Outage Rate, Mean Cumulative Function, Traction Power Supply, Electrified Railway Systems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22146058 Building Relationship Network for Machine Analysis from Wear Debris Measurements
Authors: Qurban A Memon, Mohammad S. Laghari
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Integration of system process information obtained through an image processing system with an evolving knowledge database to improve the accuracy and predictability of wear debris analysis is the main focus of the paper. The objective is to automate intelligently the analysis process of wear particle using classification via self-organizing maps. This is achieved using relationship measurements among corresponding attributes of various measurements for wear debris. Finally, visualization technique is proposed that helps the viewer in understanding and utilizing these relationships that enable accurate diagnostics.Keywords: Relationship Network, Relationship Measurement, Self-organizing Clusters, Wear Debris Analysis, Kohonen Network
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19376057 Bipolar PWM and LCL Filter Configuration to Reduce Leakage Currents in Transformerless PV System Connected to Utility Grid
Authors: Shanmuka Naga Raju
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This paper presents PV system without considering transformer connected to electric grid. This is considered more economic compared to present PV system. The problem that occurs when transformer is not considered appears with a leakage current near capacitor connected to ground. Bipolar Pulse Width Modulation (BPWM) technique along with filter L-C-L configuration in the circuit is modeled to shrink the leakage current in the circuit. The DC/AC inverter is modeled using H-bridge Insulated Gate Bipolar Transistor (IGBT) module which is controlled using proposed Bipolar PWM control technique. To extract maximum power, Maximum Power Point Technique (MPPT) controller is used in this model. Voltage and current regulators are used to determine the reference voltage for the inverter from active and reactive current where reactive current is set to zero. The PLL is modeled to synchronize the measurements. The model is designed with MATLAB Simulation blocks and compared with the methods available in literature survey to show its effectiveness.Keywords: Photovoltaic, PV, pulse width modulation, PWM, perturb and observe, phase locked loop.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10186056 A Novel Approach to Handle Uncertainty in Health System Variables for Hospital Admissions
Authors: Manisha Rathi, Thierry Chaussalet
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Hospital staff and managers are under pressure and concerned for effective use and management of scarce resources. The hospital admissions require many decisions that have complex and uncertain consequences for hospital resource utilization and patient flow. It is challenging to predict risk of admissions and length of stay of a patient due to their vague nature. There is no method to capture the vague definition of admission of a patient. Also, current methods and tools used to predict patients at risk of admission fail to deal with uncertainty in unplanned admission, LOS, patients- characteristics. The main objective of this paper is to deal with uncertainty in health system variables, and handles uncertain relationship among variables. An introduction of machine learning techniques along with statistical methods like Regression methods can be a proposed solution approach to handle uncertainty in health system variables. A model that adapts fuzzy methods to handle uncertain data and uncertain relationships can be an efficient solution to capture the vague definition of admission of a patient.Keywords: Admission, Fuzzy, Regression, Uncertainty
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14196055 Implementation of Edge Detection Based on Autofluorescence Endoscopic Image of Field Programmable Gate Array
Authors: Hao Cheng, Zhiwu Wang, Guozheng Yan, Pingping Jiang, Shijia Qin, Shuai Kuang
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Autofluorescence Imaging (AFI) is a technology for detecting early carcinogenesis of the gastrointestinal tract in recent years. Compared with traditional white light endoscopy (WLE), this technology greatly improves the detection accuracy of early carcinogenesis, because the colors of normal tissues are different from cancerous tissues. Thus, edge detection can distinguish them in grayscale images. In this paper, based on the traditional Sobel edge detection method, optimization has been performed on this method which considers the environment of the gastrointestinal, including adaptive threshold and morphological processing. All of the processes are implemented on our self-designed system based on the image sensor OV6930 and Field Programmable Gate Array (FPGA), The system can capture the gastrointestinal image taken by the lens in real time and detect edges. The final experiments verified the feasibility of our system and the effectiveness and accuracy of the edge detection algorithm.
Keywords: AFI, edge detection, adaptive threshold, morphological processing, OV6930, FPGA.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6556054 Light Tracking Fault Tolerant Control System
Authors: J. Florescu, T. Vinay, L. Wang
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A fault detection and identification (FDI) technique is presented to create a fault tolerant control system (FTC). The fault detection is achieved by monitoring the position of the light source using an array of light sensors. When a decision is made about the presence of a fault an identification process is initiated to locate the faulty component and reconfigure the controller signals. The signals provided by the sensors are predictable; therefore the existence of a fault is easily identified. Identification of the faulty sensor is based on the dynamics of the frame. The technique is not restricted to a particular type of controllers and the results show consistency.Keywords: algorithm, detection and diagnostic, fault-tolerantcontrol, fault detection and identification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14076053 Attempt to Reuse Used-PCs as Distributed Storage
Authors: Toshiya Kawato, Shin-ichi Motomura, Masayuki Higashino, Takao Kawamura
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Storage for storing data is indispensable. If a storage capacity becomes insufficient, we can increase its capacity by adding new disks. It is, however, difficult to add a new disk when a budget is not enough. On the other hand, there are many unused idle resources such as used personal computers despite those use value. In order to solve those problems, used personal computers can be reused as storage. In this paper, we attempt to reuse used-PCs as a distributed storage. First, we list up the characteristics of used-PCs and design a storage system that utilizes its characteristics. Next, we experimentally implement an auto-construction system that automatically constructs a distributed storage environment in used-PCs.Keywords: Distributed storage, used personal computer, idle resource, auto construction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10266052 Effect of Chemical Modifier on the Properties of Polypropylene (PP) / Coconut Fiber (CF) in Automotive Application
Authors: K. Shahril, A. Nizam, M. Sabri, A. Siti Rohana, H. Salmah
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Chemical modifier (Acrylic Acid) is used as filler treatment to improve mechanical properties and swelling behavior of polypropylene/coconut fiber (PP/CF) composites by creating more adherent bonding between CF filler and PP Matrix. Treated (with chemical modifier) and untreated (without chemical modifier) composites were prepared in the formulation of 10 wt%, 20 wt%, 30 wt%, and 40 wt%. The mechanical testing indicates that composite with 10 wt% of untreated composite has the optimum value of tensile strength, and the composite with chemical modifier shows the tensile strength was increased. By increasing of filler loading, elastic modulus was increased while the elongation at brake was decreased. Meanwhile, the swelling test discerned that the increase of filler loading increased the water absorption of composites and the presence of chemical modifier reduced the equilibrium water absorption percentage.
Keywords: Coconut fiber, polypropylene, acid acrylic, ethanol, chemical modifier, composites.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12796051 Potential of High Performance Ring Spinning Based on Superconducting Magnetic Bearing
Authors: M. Hossain, A. Abdkader, C. Cherif, A. Berger, M. Sparing, R. Hühne, L. Schultz, K. Nielsch
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Due to the best quality of yarn and the flexibility of the machine, the ring spinning process is the most widely used spinning method for short staple yarn production. However, the productivity of these machines is still much lower in comparison to other spinning systems such as rotor or air-jet spinning process. The main reason for this limitation lies on the twisting mechanism of the ring spinning process. In the ring/traveler twisting system, each rotation of the traveler along with the ring inserts twist in the yarn. The rotation of the traveler at higher speed includes strong frictional forces, which in turn generates heat. Different ring/traveler systems concerning with its geometries, material combinations and coatings have already been implemented to solve the frictional problem. However, such developments can neither completely solve the frictional problem nor increase the productivity. The friction free superconducting magnetic bearing (SMB) system can be a right alternative replacing the existing ring/traveler system. The unique concept of SMB bearings is that they possess a self-stabilizing behavior, i.e. they remain fully passive without any necessity for expensive position sensing and control. Within the framework of a research project funded by German research foundation (DFG), suitable concepts of the SMB-system have been designed, developed, and integrated as a twisting device of ring spinning replacing the existing ring/traveler system. With the help of the developed mathematical model and experimental investigation, the physical limitations of this innovative twisting device in the spinning process have been determined. The interaction among the parameters of the spinning process and the superconducting twisting element has been further evaluated, which derives the concrete information regarding the new spinning process. Moreover, the influence of the implemented SMB twisting system on the yarn quality has been analyzed with respect to different process parameters. The presented work reveals the enormous potential of the innovative twisting mechanism, so that the productivity of the ring spinning process especially in case of thermoplastic materials can be at least doubled for the first time in a hundred years. The SMB ring spinning tester has also been presented in the international fair “International Textile Machinery Association (ITMA) 2015”.
Keywords: Ring spinning, superconducting magnetic bearing, yarn properties, productivity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9406050 Driver Readiness in Autonomous Vehicle Take-Overs
Authors: Abdurrahman Arslanyilmaz, Salman Al Matouq, Durmus V. Doner
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Level 3 autonomous vehicles are able to take full responsibility over the control of the vehicle unless a system boundary is reached or a system failure occurs, in which case, the driver is expected to take-over the control of the vehicle. While this happens, the driver is often not aware of the traffic situation or is engaged in a secondary task. Factors affecting the duration and quality of take-overs in these situations have included secondary task type and nature, traffic density, take-over request (TOR) time, and TOR warning type and modality. However, to the best of the authors’ knowledge, no prior study examined time buffer for TORs when a system failure occurs immediately before intersections. The first objective of this study is to investigate the effect of time buffer (3 and 7 seconds) on the duration and quality of take-overs when a system failure occurs just prior to intersections. In addition, eye-tracking has become one of the most popular methods to report what individuals view, in what order, for how long, and how often, and it has been utilized in driving simulations with various objectives. However, to the extent of authors’ knowledge, none has compared drivers’ eye gaze behavior in the two different time buffers in order to examine drivers’ attention and comprehension of salient information. The second objective is to understand the driver’s attentional focus on comprehension of salient traffic-related information presented on different parts of the dashboard and on the roads.Keywords: Autonomous vehicles, driving simulation, eye gaze, attention, comprehension, take-over duration, take-over quality, time buffer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8856049 Performance Analysis of Organic Rankine Cycle Technology to Exploit Low-Grade Waste Heat to Power Generation in Indian Industry
Authors: Bipul Krishna Saha, Basab Chakraborty, Ashish Alex Sam, Parthasarathi Ghosh
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The demand for energy is cumulatively increasing with time. Since the availability of conventional energy resources is dying out gradually, significant interest is being laid on searching for alternate energy resources and minimizing the wastage of energy in various fields. In such perspective, low-grade waste heat from several industrial sources can be reused to generate electricity. The present work is to further the adoption of the Organic Rankine Cycle (ORC) technology in Indian industrial sector. The present paper focuses on extending the previously reported idea to the next level through a comparative review with three different working fluids using practical data from an Indian industrial plant. For comprehensive study in the simulation platform of Aspen Hysys®, v8.6, the waste heat data has been collected from a current coke oven gas plant in India. A parametric analysis of non-regenerative ORC and regenerative ORC is executed using the working fluids R-123, R-11 and R-21 for subcritical ORC system. The primary goal is to determine the optimal working fluid considering various system parameters like turbine work output, obtained system efficiency, irreversibility rate and second law efficiency under applied multiple heat source temperature (160 °C- 180 °C). Selection of the turbo-expanders is one of the most crucial tasks for low-temperature applications in ORC system. The present work is an attempt to make suitable recommendation for the appropriate configuration of the turbine. In a nutshell, this study justifies the proficiency of integrating the ORC technology in Indian perspective and also finds the appropriate parameter of all components integrated in ORC system for building up an ORC prototype.
Keywords: Organic rankine cycle, regenerative organic rankine cycle, waste heat recovery, Indian industry.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12686048 Best Option for Countercyclical Capital Buffer Implementation - Scenarios for Baltic States
Authors: Ģirts Brasliņš, Ilja Arefjevs, Nadežda Tarakanova
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The objective of countercyclical capital buffer is to encourage banks to build up buffers in good times that can be drawn down in bad times. The aim of the report is to assess such decisions by banks derived from three approaches. The approaches are the aggregate credit-to-GDP ratio, credit growth as well as banking sector profits. The approaches are implemented for Estonia, Latvia and Lithuania for the time period 2000-2012. The report compares three approaches and analyses their relevance to the Baltic States by testing the correlation between a growth in studied variables and a growth of corresponding gaps. Methods used in the empirical part of the report are econometric analysis as well as economic analysis, development indicators, relative and absolute indicators and other methods. The research outcome is a cross-Baltic comparison of two alternative approaches to establish or release a countercyclical capital buffer by banks and their implications for each Baltic country.
Keywords: Basel III, countercyclical capital buffer, banks, credit growth, Baltic States.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18706047 Engineered Cement Composite Materials Characterization for Tunneling Applications
Authors: S. Boughanem, D. A. Jesson, M. J. Mulheron, P.A. Smith C. Eddie, S. Psomas, M. Rimes
Abstract:
Cements, which are intrinsically brittle materials, can exhibit a degree of pseudo-ductility when reinforced with a sufficient volume fraction of a fibrous phase. This class of materials, called Engineered Cement Composites (ECC) has the potential to be used in future tunneling applications where a level of pseudo-ductility is required to avoid brittle failures. However uncertainties remain regarding mechanical performance. Previous work has focused on comparatively thin specimens; however for future civil engineering applications, it is imperative that the behavior in tension of thicker specimens is understood. In the present work, specimens containing cement powder and admixtures have been manufactured following two different processes and tested in tension. Multiple matrix cracking has been observed during tensile testing, leading to a “strain-hardening" behavior, confirming the possible suitability of ECC material when used as thick sections (greater than 50mm) in tunneling applications.Keywords: Cement composite, polymeric fibers, pseudoductility, test-geometry.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24676046 Integration of Hydropower and Solar Photovoltaic Generation into Distribution System: Case of South Sudan
Authors: A. Amogpai
Abstract:
Hydropower and solar photovoltaic (PV) generation are crucial in sustainability and transitioning from fossil fuel to clean energy. Integrating renewable energy sources such as hydropower and solar PV into the distributed networks contributes to achieving energy balance, pollution mitigation, and cost reduction. Frequent power outages and a lack of load reliability characterize the current South Sudan electricity distribution system. The country’s electricity demand is 300 MW; however, the installed capacity is around 212.4 MW. Insufficient funds to build new electricity facilities and expand generation are the reasons for the gap in installed capacity. The South Sudan Ministry of Energy and Dams gave a contract to an Egyptian Elsewedy Electric Company that completed the construction of a solar PV plant in 2023. The plant has a 35 MWh battery storage and 20 MW solar PV system capacity. The construction of Juba Solar PV Park started in 2022 to increase the current installed capacity in Juba City to 53 MW. The plant will begin serving 59000 residents in Juba and save 10,886.2 t of carbon dioxide (CO2) annually.
Keywords: Renewable energy, hydropower, solar energy, photovoltaic, South Sudan.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13