Search results for: Sustainable control
1695 Working Mode and Key Technology of Thermal Vacuum Test Software for Spacecraft Test
Authors: Zhang Lei, Zhan Haiyang, Gu Miao
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A universal software platform is developed for improving the defects in the practical one. This software platform has distinct advantages in modularization, information management, and the interfaces. Several technologies such as computer technology, virtualization technology, network technology, etc. are combined together in this software platform, and four working modes are introduced in this article including single mode, distributed mode, cloud mode, and the centralized mode. The application area of the software platform is extended through the switch between these working modes. The software platform can arrange the thermal vacuum test process automatically. This function can improve the reliability of thermal vacuum test.
Keywords: Software platform, thermal vacuum test, control and measurement, work mode.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12991694 The Importance of Zenithal Lighting Systems for Natural Light Gains and for Local Energy Generation in Brazil
Authors: Ana Paula Esteves, Diego S. Caetano, Louise L. B. Lomardo
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This paper presents an approach on the advantages of using adequate coverage in the zenithal lighting typology in various areas of architectural production, while at the same time to encourage to the design concerns inherent in this choice of roofing in Brazil. Understanding that sustainability needs to cover several aspects, a roofing system such as zenithal lighting system can contribute to the provision of better quality natural light for the interior of the building, which is related to the good health and welfare; it will also be able to contribute for the sustainable aspects and environmental needs, when it allows the generation of energy in semitransparent or opacity photovoltaic solutions and economize the artificial lightning. When the energy balance in the building is positive, that is, when the building generates more energy than it consumes, it may fit into the Net Zero Energy Building concept. The zenithal lighting systems could be an important ally in Brazil, when solved the burden of heat gains, participate in the set of pro-efficiency actions in search of "zero energy buildings". The paper presents comparative three cases of buildings that have used this feature in search of better environmental performance, both in light comfort and sustainability as a whole. Two of these buildings are examples in Europe: the Notley Green School in the UK and the Isofóton factory in Spain. The third building with these principles of shed´s roof is located in Brazil: the Ipel´s factory in São Paulo.
Keywords: Natural lightning, net zero energy building, sheds, semi-transparent photovoltaics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10381693 Energy-Efficient Sensing Concept for a Micromachined Yaw Rate Sensor
Authors: D. Oshinubi, M. Rocznik, K. Dostert
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The need for micromechanical inertial sensors is increasing in future electronic stability control (ESC) and other positioning, navigation and guidance systems. Due to the rising density of sensors in automotive and consumer devices the goal is not only to get high performance, robustness and smaller package sizes, but also to optimize the energy management of the overall sensor system. This paper presents an evaluation concept for a surface micromachined yaw rate sensor. Within this evaluation concept an energy-efficient operation of the drive mode of the yaw rate sensor is enabled. The presented system concept can be realized within a power management subsystem.Keywords: inertial sensors, micromachined gyros, gyro sensing concepts, power management, FPGA
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15061692 Dyeing Properties of Natural Dyes on Silk Treated with ß-Cyclodextrin
Authors: Samera Salimpour Abkenar
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In this work, silk yarns were treated using ß-cyclodextrin (ß-CD) and cross-linked with citric acid (CA) via pad-dry-cure method. Elemental and FESEM analyses confirmed the presence of ß-CD on the treated silk samples even after five washing cycles. Then, the treated samples were dyed using natural dyes (carrot, orange and tomato). Results showed that the color strength (K/S) of the treated samples had been markedly enhanced compared with the control sample (after treatment with metal mordant). Finally, the color strength (K/S value) and color fastness (fading, staining and light fastness) of the treated samples with ß-CD were investigated and compared.
Keywords: ß-cyclodextrin, dyeing, natural dyes, silk yarn.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6251691 A Case Study of Limited Dynamic Voltage Frequency Scaling in Low-Power Processors
Authors: Hwan Su Jung, Ahn Jun Gil, Jong Tae Kim
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Power management techniques are necessary to save power in the microprocessor. By changing the frequency and/or operating voltage of processor, DVFS can control power consumption. In this paper, we perform a case study to find optimal power state transition for DVFS. We propose the equation to find the optimal ratio between executions of states while taking into account the deadline of processing time and the power state transition delay overhead. The experiment is performed on the Cortex-M4 processor, and average 6.5% power saving is observed when DVFS is applied under the deadline condition.
Keywords: Deadline, Dynamic Voltage Frequency Scaling, Power State Transition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9591690 Static Voltage Stability Margin Enhancement Using SVC and TCSC
Authors: Mohammed Amroune, Hadi Sebaa, Tarek Bouktir
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Reactive power limit of power system is one of the major causes of voltage instability. The only way to save the system from voltage instability is to reduce the reactive power load or add additional reactive power to reaching the point of voltage collapse. In recent times, the application of FACTS devices is a very effective solution to prevent voltage instability due to their fast and very flexible control. In this paper, voltage stability assessment with SVC and TCSC devices is investigated and compared in the modified IEEE 30-bus test system. The fast voltage stability indicator (FVSI) is used to identify weakest bus and to assess the voltage stability of power system.
Keywords: SVC, TCSC, Voltage stability, Fast Voltage Stability Index (FVSI), Reactive power.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 40751689 Water Resources Crisis in Saudi Arabia, Challenges and Possible Management Options: An Analytic Review
Authors: A. A. Ghanim
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The Kingdom of Saudi Arabia (KSA) is heading towards a severe and rapidly expanding water crisis, which can have negative impacts on the country’s environment and economy. Of the total water consumption in KSA, the agricultural sector accounts for nearly 87% of the total water use and, therefore, any attempt that overlooks this sector will not help in improving the sustainability of the country’s water resources. KSA Vision 2030 gives priority of water use in the agriculture sector for the regions that have natural renewable water resources. It means that there is little concern for making reuse of municipal wastewater for irrigation purposes in any region in general and in water-scarce regions in particular. The use of treated wastewater is very limited in Saudi Arabia, but it has very considerable potential for future expansion due its numerous beneficial uses. This study reviews the current situation of water resources in Saudi Arabia, providing more highlights on agriculture and wastewater reuse. The reviewed study is proposing some corrective measures for development and better management of water resources in the Kingdom. Suggestions also include consideration of treated water as an alternative source for irrigation in some regions of the country. The study concluded that a sustainable solution for the water crisis in KSA requires implementation of multiple measures in an integrated manner. The integrated solution plan should focus on two main directions: first, improving the current management practices of the existing water resources; second, developing new water supplies from both conventional and non-conventional sources.Keywords: Saudi Arabia, water resources, water crisis, treated wastewater.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19381688 Two Day Ahead Short Term Load Forecasting Neural Network Based
Authors: Firas M. Tuaimah
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This paper presents an Artificial Neural Network based approach for short-term load forecasting and exactly for two days ahead. Two seasons have been discussed for Iraqi power system, namely summer and winter; the hourly load demand is the most important input variables for ANN based load forecasting. The recorded daily load profile with a lead time of 1-48 hours for July and December of the year 2012 was obtained from the operation and control center that belongs to the Ministry of Iraqi electricity.
The results of the comparison show that the neural network gives a good prediction for the load forecasting and for two days ahead.
Keywords: Short-Term Load Forecasting, Artificial Neural Networks, Back propagation learning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15601687 An Environmental Impact Tool to Assess National Energy Scenarios
Authors: R. Taviv, A.C. Brent, H. Fortuin
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The Long-range Energy and Alternatives Planning (LEAP) energy planning system has been developed for South Africa, for the 2005 base year and a limited number of plausible future scenarios that may have significant implications (negative or positive) in terms of environmental impacts. The system quantifies the national energy demand for the domestic, commercial, transport, industry and agriculture sectors, the supply of electricity and liquid fuels, and the resulting emissions. The South African National Energy Research Institute (SANERI) identified the need to develop an environmental assessment tool, based on the LEAP energy planning system, to provide decision-makers and stakeholders with the necessary understanding of the environmental impacts associated with different energy scenarios. A comprehensive analysis of indicators that are used internationally and in South Africa was done and the available data was accessed to select a reasonable number of indicators that could be utilized in energy planning. A consultative process was followed to determine the needs of different stakeholders on the required indicators and also the most suitable form of reporting. This paper demonstrates the application of Energy Environmental Sustainability Indicators (EESIs) as part of the developed tool, which assists with the identification of the environmental consequences of energy generation and use scenarios and thereby promotes sustainability, since environmental considerations can then be integrated into the preparation and adoption of policies, plans, programs and projects. Recommendations are made to refine the tool further for South Africa.
Keywords: Energy modeling, LEAP, environmental impact, environmental indicators, energy sector emissions, sustainable development, South Africa
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16271686 An Evaluation of Requirements Management and Traceability Tools
Authors: Muhammad Shahid, Suhaimi Ibrahim, Mohd Naz'ri Mahrin
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Requirements management is critical to software delivery success and project lifecycle. Requirements management and their traceability provide assistance for many software engineering activities like impact analysis, coverage analysis, requirements validation and regression testing. In addition requirements traceability is the recognized component of many software process improvement initiatives. Requirements traceability also helps to control and manage evolution of a software system. This paper aims to provide an evaluation of current requirements management and traceability tools. Management and test managers require an appropriate tool for the software under test. We hope, evaluation identified here will help to select the efficient and effective tool.Keywords: Requirements Traceability, Requirements TraceabilityTools; Requirements Management, Requirement Engineering
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 40201685 Fiber Optic Sensors
Authors: Bahareh Gholamzadeh, Hooman Nabovati
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Fiber optic sensor technology offers the possibility of sensing different parameters like strain, temperature, pressure in harsh environment and remote locations. these kinds of sensors modulates some features of the light wave in an optical fiber such an intensity and phase or use optical fiber as a medium for transmitting the measurement information. The advantages of fiber optic sensors in contrast to conventional electrical ones make them popular in different applications and now a day they consider as a key component in improving industrial processes, quality control systems, medical diagnostics, and preventing and controlling general process abnormalities. This paper is an introduction to fiber optic sensor technology and some of the applications that make this branch of optic technology, which is still in its early infancy, an interesting field.Keywords: Fiber optic sensors, distributed sensors, sensorapplication, crack sensor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 65221684 Security Engine Management of Router based on Security Policy
Authors: Su Hyung Jo, Ki Young Kim, Sang Ho Lee
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Security management has changed from the management of security equipments and useful interface to manager. It analyzes the whole security conditions of network and preserves the network services from attacks. Secure router technology has security functions, such as intrusion detection, IPsec(IP Security) and access control, are applied to legacy router for secure networking. It controls an unauthorized router access and detects an illegal network intrusion. This paper relates to a security engine management of router based on a security policy, which is the definition of security function against a network intrusion. This paper explains the security policy and designs the structure of security engine management framework.Keywords: Policy server, security engine, security management, security policy
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19211683 Entropy Generation for Natural Convection in a Darcy – Brinkman Porous Cavity
Authors: Ali Mchirgui, Nejib Hidouri, Mourad Magherbi, Ammar Ben Brahim
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The paper provides a numerical investigation of the entropy generation analysis due to natural convection in an inclined square porous cavity. The coupled equations of mass, momentum, energy and species conservation are solved using the Control Volume Finite-Element Method. Effect of medium permeability and inclination angle on entropy generation is analysed. It was found that according to the Darcy number and the porous thermal Raleigh number values, the entropy generation could be mainly due to heat transfer or to fluid friction irreversibility and that entropy generation reaches extremum values for specific inclination angles.Keywords: Porous media, entropy generation, convection, numerical method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26081682 Overview of Adaptive Spline Interpolation
Authors: Rongli Gai, Zhiyuan Chang, Xiaohong Wang, Jingyu Liu
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In view of various situations in the interpolation process, most researchers use self-adaptation to adjust the interpolation process, which is also one of the current and future research hotspots in the field of CNC (Computerized Numerical Control) machining. In the interpolation process, according to the overview of the spline curve interpolation algorithm, the adaptive analysis is carried out from the factors affecting the interpolation process. The adaptive operation is reflected in various aspects, such as speed, parameters, errors, nodes, feed rates, random period, sensitive point, step size, curvature, adaptive segmentation, adaptive optimization, etc. This paper will analyze and summarize the research of adaptive imputation in the direction of the above factors affecting imputation.
Keywords: Adaptive algorithm, CNC machining, interpolation constraints, spline curve interpolation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5521681 Control of Aspergillus flavus Growth in Tomato Paste by Cinnamomum zeylanicum and Origanum vulgare L. Essential Oils
Authors: F. Kalantari, M. Barzegar, Z. Hamidi-Esfahani
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This study was conducted to evaluate the antifungal activities of Cinnamomum zeylanicum and Origanum vulgare L. essential oil against Aspergillus flavus in culture media and tomato paste. 200 ppm of cinnamon and 500 ppm of oregano completely inhibited A. flavus growth in culture media, while in tomato paste 300 ppm of cinnamon and 200 ppm of oregano had the same effect. Test panel evaluations revealed that samples with 100 and 200 ppm cinnamon were acceptable. The results may suggest the potential use of Cinnamomum zeylanicum essential oil as natural preservative in tomato paste.Keywords: Antimicrobial, Food safety, GC/MS, Natural preservative
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26691680 Influence of Cell-free Proteins in the Nucleation of CaCO3 Crystals in Calcified Endoskeleton
Authors: M. Azizur Rahman, Tamotsu Oomori
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Calcite aCalcite and aragonite are the two common polymorphs of CaCO3 observed as biominerals. It is universal that the sea water contents a high Mg2+ (50mM) relative to Ca2+ (10mM). In vivo crystallization, Mg2+ inhibits calcite formation. For this reason, stony corals skeleton may be formed only aragonite crystals in the biocalcification. It is special in case of soft corals of which formed only calcite crystal; however, this interesting phenomenon, still uncharacterized in the marine environment, has been explored in this study using newly purified cell-free proteins isolated from the endoskeletal sclerites of soft coral. By recording the decline of pH in vitro, the control of CaCO3 nucleation and crystal growth by the cellfree proteins was revealed. Using Atomic Force Microscope, here we find that these endoskeletal cell-free proteins significantly design the morphological shape in the molecular-scale kinetics of crystal formation and those proteins act as surfactants to promote ion attachment at calcite steps.nd aragonite are the two common polymorphs of CaCO3 observed as biominerals. It is universal that the sea water contents a high Mg2+ (50mM) relative to Ca2+ (10mM). In vivo crystallization, Mg2+ inhibits calcite formation. For this reason, stony corals skeleton may be formed only aragonite crystals in the biocalcification. It is special in case of soft corals of which formed only calcite crystal; however, this interesting phenomenon, still uncharacterized in the marine environment, has been explored in this study using newly purified cell-free proteins isolated from the endoskeletal sclerites of soft coral. By recording the decline of pH in vitro, the control of CaCO3 nucleation and crystal growth by the cell-free proteins was revealed. Using Atomic Force Microscope, here we find that these endoskeletal cell-free proteins significantly design the morphological shape in the molecular-scale kinetics of crystal formation and those proteins act as surfactants to promote ion attachment at calcite steps. KeywordsBiomineralization, Calcite, Cell-free protein, Soft coralKeywords: Biomineralization, Calcite, Cell-free protein, Soft coral
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15521679 Low Power Consuming Electromagnetic Actuators for Pulsed Pilot Stages
Authors: M. Honarpardaz, Z. Zhang, J. Derkx, A. Trangärd, J. Larsson
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Pilot stages are one of the most common positioners and regulators in industry. In this paper, we present two novel concepts for pilot stages with low power consumption to regulate a pneumatic device. Pilot 1, first concept, is designed based on a conventional frame core electro-magnetic actuator and a leaf spring to control the air flow and pilot 2 has an axisymmetric actuator and spring made of non-oriented electrical steel. Concepts are simulated in a system modeling tool to study their dynamic behavior. Both concepts are prototyped and tested. Experimental results are comprehensively analyzed and compared. The most promising concept that consumes less than 8 mW is highlighted and presented.Keywords: Electro-magnetic actuator, multidisciplinary system, low power consumption, pilot stage.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9671678 Tracking Trajectory of a Cable-Driven Robot for Lower Limb Rehabilitation
Authors: Hachmia Faqihi, Maarouf Saad, Khalid Benjelloun, Mohammed Benbrahim, M. Nabil Kabbaj
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This paper investigates and presents a cable-driven robot to lower limb rehabilitation use in sagittal plane. The presented rehabilitation robot is used for a trajectory tracking in joint space. The paper covers kinematic and dynamic analysis, which reveals the tensionability of the used cables as being the actuating source to provide a rehabilitation exercises of the human leg. The desired trajectory is generated to be used in the control system design in joint space. The obtained simulation results is showed to be efficient in this kind of application.Keywords: Cable-driven multibody system, computed-torque controller, lower limb rehabilitation, tracking trajectory.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17581677 Analysis of Control by Flattening of the Welded Tubes
Authors: Hannachi Med Tahar, H. Djebaili, B. Daheche
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In this approach, we have tried to describe the flattening of welded tubes, and its experimental application. The test is carried out at the (National product processing company dishes and tubes production). Usually, the final products (tubes) undergo a series of non-destructive inspection online and offline welding, and obviously destructive mechanical testing (bending, flattening, flaring, etc.). For this and for the purpose of implementing the flattening test, which applies to the processing of round tubes in other forms, it took four sections of welded tubes draft (before stretching hot) and welded tubes finished (after drawing hot and annealing), it was also noted the report 'health' flattened tubes must not show or crack or tear. The test is considered poor if it reveals a lack of ductility of the metal.
Keywords: Flattening, destructive testing, tube drafts, finished tube, Castem 2001.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12761676 Spatial Optimization of Riverfront Street Based on Inclusive Design: Case Study of Wansheng District, China
Authors: Lianxue Shi
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Riverfront streets have the dual characteristics of street space and waterfront space, which is not only a vital place for residents to travel and communicate, but also a high-frequency space for people's leisure and entertainment. However, under the development of cities and towns pursuing efficiency, riverfront streets appear to have a variety of problems, such as a lack of multifunctionality, insufficient facilities, and loss of characteristics, which fail to meet the needs of various groups of people, and their inclusiveness is facing a great challenge. It is, therefore, evident that the optimization of riverfront street space from an inclusivity perspective is important to the establishment of a human-centered, high-quality urban space. Therefore, this article starts by exploring the interactive relationship between inclusive design and street space. Based on the analysis of the characteristics of the riverfront street space and people's needs, it proposes the four inclusive design orientations of natural inclusion, group inclusion, spatial inclusion, and social inclusion. It then constructs a design framework for the inclusive optimization of riverfront street space, aiming to create streets that are “safe and accessible, diverse and shared, distinctive and friendly, green and sustainable”. Riverfront streets in Wansheng District, Chongqing, are selected as a practice case, and specific strategies are put forward in four aspects: the creation of an accessible slow-traffic system, the provision of diversified functional services, the reshaping of emotional bonds, and the integration of ecological spaces.
Keywords: Inclusive design, riverfront street, spatial optimization, street spaces.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 211675 Retrospective Reconstruction of Time Series Data for Integrated Waste Management
Authors: A. Buruzs, M. F. Hatwágner, A. Torma, L. T. Kóczy
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The development, operation and maintenance of Integrated Waste Management Systems (IWMS) affects essentially the sustainable concern of every region. The features of such systems have great influence on all of the components of sustainability. In order to reach the optimal way of processes, a comprehensive mapping of the variables affecting the future efficiency of the system is needed such as analysis of the interconnections among the components and modeling of their interactions. The planning of a IWMS is based fundamentally on technical and economical opportunities and the legal framework. Modeling the sustainability and operation effectiveness of a certain IWMS is not in the scope of the present research. The complexity of the systems and the large number of the variables require the utilization of a complex approach to model the outcomes and future risks. This complex method should be able to evaluate the logical framework of the factors composing the system and the interconnections between them. The authors of this paper studied the usability of the Fuzzy Cognitive Map (FCM) approach modeling the future operation of IWMS’s. The approach requires two input data set. One is the connection matrix containing all the factors affecting the system in focus with all the interconnections. The other input data set is the time series, a retrospective reconstruction of the weights and roles of the factors. This paper introduces a novel method to develop time series by content analysis.
Keywords: Content analysis, factors, integrated waste management system, time series.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20181674 A Grid Synchronization Method Based on Adaptive Notch Filter for SPV System with Modified MPPT
Authors: Priyanka Chaudhary, M. Rizwan
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This paper presents a grid synchronization technique based on adaptive notch filter for SPV (Solar Photovoltaic) system along with MPPT (Maximum Power Point Tracking) techniques. An efficient grid synchronization technique offers proficient detection of various components of grid signal like phase and frequency. It also acts as a barrier for harmonics and other disturbances in grid signal. A reference phase signal synchronized with the grid voltage is provided by the grid synchronization technique to standardize the system with grid codes and power quality standards. Hence, grid synchronization unit plays important role for grid connected SPV systems. As the output of the PV array is fluctuating in nature with the meteorological parameters like irradiance, temperature, wind etc. In order to maintain a constant DC voltage at VSC (Voltage Source Converter) input, MPPT control is required to track the maximum power point from PV array. In this work, a variable step size P & O (Perturb and Observe) MPPT technique with DC/DC boost converter has been used at first stage of the system. This algorithm divides the dPpv/dVpv curve of PV panel into three separate zones i.e. zone 0, zone 1 and zone 2. A fine value of tracking step size is used in zone 0 while zone 1 and zone 2 requires a large value of step size in order to obtain a high tracking speed. Further, adaptive notch filter based control technique is proposed for VSC in PV generation system. Adaptive notch filter (ANF) approach is used to synchronize the interfaced PV system with grid to maintain the amplitude, phase and frequency parameters as well as power quality improvement. This technique offers the compensation of harmonics current and reactive power with both linear and nonlinear loads. To maintain constant DC link voltage a PI controller is also implemented and presented in this paper. The complete system has been designed, developed and simulated using SimPower System and Simulink toolbox of MATLAB. The performance analysis of three phase grid connected solar photovoltaic system has been carried out on the basis of various parameters like PV output power, PV voltage, PV current, DC link voltage, PCC (Point of Common Coupling) voltage, grid voltage, grid current, voltage source converter current, power supplied by the voltage source converter etc. The results obtained from the proposed system are found satisfactory.
Keywords: Solar photovoltaic systems, MPPT, voltage source converter, grid synchronization technique.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19701673 A New Approach for Recoverable Timestamp Ordering Schedule
Authors: Hassan M. Najadat
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A new approach for timestamp ordering problem in serializable schedules is presented. Since the number of users using databases is increasing rapidly, the accuracy and needing high throughput are main topics in database area. Strict 2PL does not allow all possible serializable schedules and so does not result high throughput. The main advantages of the approach are the ability to enforce the execution of transaction to be recoverable and the high achievable performance of concurrent execution in central databases. Comparing to Strict 2PL, the general structure of the algorithm is simple, free deadlock, and allows executing all possible serializable schedules which results high throughput. Various examples which include different orders of database operations are discussed.Keywords: Concurrency control, schedule, timestamp, transaction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20881672 Investigation of the Effects of Sampling Frequency on the THD of 3-Phase Inverters Using Space Vector Modulation
Authors: Khattab Ibrahim Al Qaisi, Nicholas Bowring
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This paper presents the simulation results of the effects of sampling frequency on the total harmonic distortion (THD) of three-phase inverters using the space vector pulse width modulation (SVPWM) and space vector control (SVC) algorithms. The relationship between the variables was studied using curve fitting techniques, and it has been shown that, for 50 Hz inverters, there is an exponential relation between the sampling frequency and THD up to around 8500 Hz, beyond which the performance of the model becomes irregular, and there is an negative exponential relation between the sampling frequency and the marginal improvement to the THD. It has also been found that the performance of SVPWM is better than that of SVC with the same sampling frequency in most frequency range, including the range where the performance of the former is irregular.
Keywords: SVPWM, THD, DC-AC Inverter, Sampling Frequency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29771671 Technological Advancement in Fashion Online Retailing: A Comparative Study of Pakistan and UK Fashion E-Commerce
Authors: Sadia Idrees, Gianpaolo Vignali, Simeon Gill
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The study aims to establish the virtual size and fit technology features to enhance fashion online retailing platforms, utilising digital human measurements to provide customised style and function to consumers. A few firms in the UK have launched advanced interactive fashion shopping domains for personalised shopping globally, aided by the latest internet technology. Virtual size and fit interfaces have a great potential to provide a personalised better-fitted garment to promote mass customisation globally. Made-to-measure clothing, consuming unstitched fabric is a common practice offered by fashion brands in Pakistan. This product is regarded as economical and sustainable to be utilised by consumers in Pakistan. Although the manual sizing system is practiced to sell garments online, virtual size and fit visualisation and recommendation technologies are uncommon in Pakistani fashion interfaces. A comparative assessment of Pakistani fashion brand websites and UK technology-driven fashion interfaces was conducted to highlight the vast potential of the virtual size and fit technology. The results indicated that web 2.0 technology adopted by Pakistani apparel brands has limited features, whereas companies practicing web 3.0 technology provide interactive online real-store shopping experience leading to enhanced customer satisfaction and globalisation of brands.
Keywords: E-commerce, mass customization, virtual size and fit, web 3.0 technology.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11531670 SIP Authentication Scheme using ECDH
Authors: Aytunc Durlanik, Ibrahim Sogukpinar
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SIP (Session Initiation Protocol), using HTML based call control messaging which is quite simple and efficient, is being replaced for VoIP networks recently. As for authentication and authorization purposes there are many approaches and considerations for securing SIP to eliminate forgery on the integrity of SIP messages. On the other hand Elliptic Curve Cryptography has significant advantages like smaller key sizes, faster computations on behalf of other Public Key Cryptography (PKC) systems that obtain data transmission more secure and efficient. In this work a new approach is proposed for secure SIP authentication by using a public key exchange mechanism using ECC. Total execution times and memory requirements of proposed scheme have been improved in comparison with non-elliptic approaches by adopting elliptic-based key exchange mechanism.Keywords: SIP, Elliptic Curve Cryptography, voice over IP.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25291669 Investigation of the Effect of Nano-Alumina Particles on Adsorption Property of Acrylic Fiber
Authors: Mehdi Ketabchi, Shallah Alijanlo
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The flue gas from fossil fuels combustion contains harmful pollutants dangerous for human health and environment. One of the air pollution control methods to restrict the emission of these pollutants is based on using the nanoparticle in adsorption process. In the present research, gamma nano-alumina particle is added to polyacrylonitrile (PAN) polymer through simple loading method, and the adsorption capacity of the wet spun fiber is investigated. The results of exposure the fiber to the acid gases including SO2, CO, NO2, NO, and CO2 show the noticeable increase of gas adsorption capacity on fiber contains nanoparticle. The research has been conducted in Acrylic II Plant of Polyacryl Iran Corporation.Keywords: Acrylic fiber, adsorbent, wet spun, polyacryl company, gamma nano-alumina.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6991668 Speedup of Data Vortex Network Architecture
Authors: Qimin Yang
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In this paper, 3X3 routing nodes are proposed to provide speedup and parallel processing capability in Data Vortex network architectures. The new design not only significantly improves network throughput and latency, but also eliminates the need for distributive traffic control mechanism originally embedded among nodes and the need for nodal buffering. The cost effectiveness is studied by a comparison study with the previously proposed 2- input buffered networks, and considerable performance enhancement can be achieved with similar or lower cost of hardware. Unlike previous implementation, the network leaves small probability of contention, therefore, the packet drop rate must be kept low for such implementation to be feasible and attractive, and it can be achieved with proper choice of operation conditions.Keywords: Data Vortex, Packet Switch, Interconnection network, deflection, Network-on-chip
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15691667 Business Process Management and Organizational Culture in Big Companies: Cross-Country Analysis
Authors: Dalia Suša Vugec
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Business process management (BPM) is widely used approach focused on designing, mapping, changing, managing and analyzing business processes of an organization, which eventually leads to better performance and derives many other benefits. Since every organization strives to improve its performance in order to be sustainable and to remain competitive on the market in long-term period, numerous organizations are nowadays adopting and implementing BPM. However, not all organizations are equally successful in that. One of the ways of measuring BPM success is by measuring its maturity by calculating Process Performance Index (PPI) using ten BPM success factors. Still, although BPM is a holistic concept, organizational culture is not taken into consideration in calculating PPI. Hence, aim of this paper is twofold; first, it aims to explore and analyze the current state of BPM success factors within the big organizations from Slovenia, Croatia, and Austria and second, it aims to analyze the structure of organizational culture within the observed companies, focusing on the link with BPM success factors as well. The presented study is based on the results of the questionnaire conducted as the part of the PROSPER project (IP-2014-09-3729) and financed by Croatian Science Foundation. The results of the questionnaire reveal differences in the achieved levels of BPM success factors and therefore BPM maturity in total between the three observed countries. Moreover, the structure of organizational culture across three countries also differs. This paper discusses the revealed differences between countries as well as the link between organizational culture and BPM success factors.
Keywords: Business process management, BPM maturity, BPM success factors, organizational culture, process performance index.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16011666 Economic effects and Energy Use Efficiency of Incorporating Alfalfa and Fertilizer into Grass- Based Pasture Systems
Authors: M. Khakbazan, S. L. Scott, H. C. Block, C. D. Robins, W. P. McCaughey
Abstract:
A ten-year grazing study was conducted at the Agriculture and Agri-Food Canada Brandon Research Centre in Manitoba to study the effect of alfalfa inclusion and fertilizer (N, P, K, and S) addition on economics and efficiency of non-renewable energy use in meadow brome grass-based pasture systems for beef production. Fertilizing grass-only or alfalfa-grass pastures to full soil test recommendations improved pasture productivity, but did not improve profitability compared to unfertilized pastures. Fertilizing grass-only pastures resulted in the highest net loss of any pasture management strategy in this study. Adding alfalfa at the time of seeding, with no added fertilizer, was economically the best pasture improvement strategy in this study. Because of moisture limitations, adding commercial fertilizer to full soil test recommendations is probably not economically justifiable in most years, especially with the rising cost of fertilizer. Improving grass-only pastures by adding fertilizer and/or alfalfa required additional non-renewable energy inputs; however, the additional energy required for unfertilized alfalfa-grass pastures was minimal compared to the fertilized pastures. Of the four pasture management strategies, adding alfalfa to grass pastures without adding fertilizer had the highest efficiency of energy use. Based on energy use and economic performance, the unfertilized alfalfa-grass pasture was the most efficient and sustainable pasture system.Keywords: Alfalfa, grass, fertilizer, pasture systems, economics, energy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1676