Search results for: dynamic explicit
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4267

Search results for: dynamic explicit

1567 Urban Form of the Traditional Arabic City in the Light of Islamic Values

Authors: Akeel Noori Al-Mulla Hwaish

Abstract:

The environmental impact, economics, social and cultural factors, and the processes by which people define history and meaning had influenced the dynamic shape and character of the traditional Islamic Arabic city. Therefore, in regard to the period when Islam was at its peak (7th- 13th Centuries), Islamic city wasn’t the highly dynamited at the scale of buildings and city planning that demonstrates a distinguished city as an ‘Islamic’ as appeared after centuries when the function of the buildings and their particular arrangement and planning scheme in relation to one another that defined an Islamic city character. The architectural features of the urban fabric of the traditional Arabic Islamic city are a ‎reflection of the spiritual, social, and cultural characteristics of the people. It is a ‎combination of Islamic values ‘Din’ and life needs ‘Dunia’ as Prophet Muhammad built the first Mosque in ‎Madinah in the 1st year of his migration to it, then the Suq or market on 2nd of Hijrah, attached to ‎the mosque to signify the birth of a new Muslims community which considers both, ‎‎’Din’ and ‘Dunia’ and initiated nucleus for what which called after that as an ‘Islamic’ city. This research will discuss the main characteristics and components of the traditional Arab cities and demonstrate the impact of the Islamic values on shaping the planning layout and general built environment features of the early traditional Arab cities.

Keywords: urban, Islamic, Arabic, city

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1566 Extraction of Road Edge Lines from High-Resolution Remote Sensing Images Based on Energy Function and Snake Model

Authors: Zuoji Huang, Haiming Qian, Chunlin Wang, Jinyan Sun, Nan Xu

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In this paper, the strategy to extract double road edge lines from acquired road stripe image was explored. The workflow is as follows: the road stripes are acquired by probabilistic boosting tree algorithm and morphological algorithm immediately, and road centerlines are detected by thinning algorithm, so the initial road edge lines can be acquired along the road centerlines. Then we refine the results with big variation of local curvature of centerlines. Specifically, the energy function of edge line is constructed by gradient feature and spectral information, and Dijkstra algorithm is used to optimize the initial road edge lines. The Snake model is constructed to solve the fracture problem of intersection, and the discrete dynamic programming algorithm is used to solve the model. After that, we could get the final road network. Experiment results show that the strategy proposed in this paper can be used to extract the continuous and smooth road edge lines from high-resolution remote sensing images with an accuracy of 88% in our study area.

Keywords: road edge lines extraction, energy function, intersection fracture, Snake model

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1565 The Social Construction of Diagnosis: An Exploratory Study on Gender Dysphoria and Its Implications on Personal Narratives

Authors: Jessica Neri, Elena Faccio

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In Europe, except for Denmark and Malta, the legal gender change and the stages of the possible process of gender transition are bound to the diagnosis of a gender identity disorder. The requirement of the evaluation of a mental disorder might have many implications on trans people’s self-representations, interpersonal relations in different social contexts and the therapeutic relations with clinicians during the transition. Psychopathological language may contribute to define the individual’s reality from normative presuppositions with value implications related to the dominant cultural principles. In an effort to mark the boundaries between sanity and pathology, it concurs to the definition of the management procedures of the constructed diversities and deviances, legitimizing the operational practices of particular professional figures. The aim of this research concerns the analysis of the diagnostic category of gender dysphoria contained in the last edition of the Diagnostic and Statistical Manual of Mental Disorders. In particular, this study focuses on the relationship between the implicit and explicit assumptions related to the expressions of gender non-conformity, that sustain the language and the criteria characterizing the Manual, and the possible implications on people’s narratives of transition. In order to achieve this objective two main research methods were used: historical reconstruction of the diagnostic category in the different versions of the Manual and content analysis of that category in the present version. From the historical analysis, in the medical and psychiatric field gender non-conformity has been predominantly explicated by naturalistic perspectives, naming it ‘transsexualism’ and collocating it in the category of gender identity disorder. Currently, pathological judged experiences are represented by gender dysphoria, described in the DSM-5 as the distress that may accompany the incongruence between one's experienced or expressed gender and one's assigned gender, specifying that there must be ‘evidence’ of this. Implicit theories about gender binary, parallelism between gender identity, sex and sexuality and the understanding of the mental health and the subject’s agency as subordinated to the expert knowledge, can be found in the process of designation of the category. A lack of awareness of the historical, social and political aspects connected to the cultural and normative dimensions at the basis of these implicit theories, can be noticed and data given by culture and data given by supposed -biological or psychological- nature, are often confused. This reductionist interpretation of gender and its presumed diversities legitimize the clinician to assume the role of searching and orienting, in a correctional perspective, the biographical elements that correspond to him specific expectations, with no space for other possibilities and identity configurations for people in transition. This research may contribute to the current critical debate about the epistemological foundation of the psychodiagnosis, emphasizing the pragmatic effects on the individuals and on the psychological practice in its wider social context. This work also permits to underline the risks due to the lack of awareness of the processes of social construction of the diagnostic system and its essential role of defence of the values that hold up the symbolic universe of reference.

Keywords: diagnosis, gender dysphoria, narratives, social constructionism

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1564 Enhancing Throughput for Wireless Multihop Networks

Authors: K. Kalaiarasan, B. Pandeeswari, A. Arockia John Francis

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Wireless, Multi-hop networks consist of one or more intermediate nodes along the path that receive and forward packets via wireless links. The backpressure algorithm provides throughput optimal routing and scheduling decisions for multi-hop networks with dynamic traffic. Xpress, a cross-layer backpressure architecture was designed to reach the capacity of wireless multi-hop networks and it provides well coordination between layers of network by turning a mesh network into a wireless switch. Transmission over the network is scheduled using a throughput-optimal backpressure algorithm. But this architecture operates much below their capacity due to out-of-order packet delivery and variable packet size. In this paper, we present Xpress-T, a throughput optimal backpressure architecture with TCP support designed to reach maximum throughput of wireless multi-hop networks. Xpress-T operates at the IP layer, and therefore any transport protocol, including TCP, can run on top of Xpress-T. The proposed design not only avoids bottlenecks but also handles out-of-order packet delivery and variable packet size, optimally load-balances traffic across them when needed, improving fairness among competing flows. Our simulation results shows that Xpress-T gives 65% more throughput than Xpress.

Keywords: backpressure scheduling and routing, TCP, congestion control, wireless multihop network

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1563 Evaluation of Nanoparticle Application to Control Formation Damage in Porous Media: Laboratory and Mathematical Modelling

Authors: Gabriel Malgaresi, Sara Borazjani, Hadi Madani, Pavel Bedrikovetsky

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Suspension-Colloidal flow in porous media occurs in numerous engineering fields, such as industrial water treatment, the disposal of industrial wastes into aquifers with the propagation of contaminants and low salinity water injection into petroleum reservoirs. The main effects are particle mobilization and captured by the porous rock, which can cause pore plugging and permeability reduction which is known as formation damage. Various factors such as fluid salinity, pH, temperature, and rock properties affect particle detachment. Formation damage is unfavorable specifically near injection and production wells. One way to control formation damage is pre-treatment of the rock with nanoparticles. Adsorption of nanoparticles on fines and rock surfaces alters zeta-potential of the surfaces and enhances the attachment force between the rock and fine particles. The main objective of this study is to develop a two-stage mathematical model for (1) flow and adsorption of nanoparticles on the rock in the pre-treatment stage and (2) fines migration and permeability reduction during the water production after the pre-treatment. The model accounts for adsorption and desorption of nanoparticles, fines migration, and kinetics of particle capture. The system of equations allows for the exact solution. The non-self-similar wave-interaction problem was solved by the Method of Characteristics. The analytical model is new in two ways: First, it accounts for the specific boundary and initial condition describing the injection of nanoparticle and production from the pre-treated porous media; second, it contains the effect of nanoparticle sorption hysteresis. The derived analytical model contains explicit formulae for the concentration fronts along with pressure drop. The solution is used to determine the optimal injection concentration of nanoparticle to avoid formation damage. The mathematical model was validated via an innovative laboratory program. The laboratory study includes two sets of core-flood experiments: (1) production of water without nanoparticle pre-treatment; (2) pre-treatment of a similar core with nanoparticles followed by water production. Positively-charged Alumina nanoparticles with the average particle size of 100 nm were used for the rock pre-treatment. The core was saturated with the nanoparticles and then flushed with low salinity water; pressure drop across the core and the outlet fine concentration was monitored and used for model validation. The results of the analytical modeling showed a significant reduction in the fine outlet concentration and formation damage. This observation was in great agreement with the results of core-flood data. The exact solution accurately describes fines particle breakthroughs and evaluates the positive effect of nanoparticles in formation damage. We show that the adsorbed concentration of nanoparticle highly affects the permeability of the porous media. For the laboratory case presented, the reduction of permeability after 1 PVI production in the pre-treated scenario is 50% lower than the reference case. The main outcome of this study is to provide a validated mathematical model to evaluate the effect of nanoparticles on formation damage.

Keywords: nano-particles, formation damage, permeability, fines migration

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1562 Online Battery Equivalent Circuit Model Estimation on Continuous-Time Domain Using Linear Integral Filter Method

Authors: Cheng Zhang, James Marco, Walid Allafi, Truong Q. Dinh, W. D. Widanage

Abstract:

Equivalent circuit models (ECMs) are widely used in battery management systems in electric vehicles and other battery energy storage systems. The battery dynamics and the model parameters vary under different working conditions, such as different temperature and state of charge (SOC) levels, and therefore online parameter identification can improve the modelling accuracy. This paper presents a way of online ECM parameter identification using a continuous time (CT) estimation method. The CT estimation method has several advantages over discrete time (DT) estimation methods for ECM parameter identification due to the widely separated battery dynamic modes and fast sampling. The presented method can be used for online SOC estimation. Test data are collected using a lithium ion cell, and the experimental results show that the presented CT method achieves better modelling accuracy compared with the conventional DT recursive least square method. The effectiveness of the presented method for online SOC estimation is also verified on test data.

Keywords: electric circuit model, continuous time domain estimation, linear integral filter method, parameter and SOC estimation, recursive least square

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1561 Molecular Detection and Characterization of Infectious Bronchitis Virus from Libya

Authors: Abdulwahab Kammon, Tan Sheau Wei, Abdul Rahman Omar, Abdunaser Dayhum, Ibrahim Eldghayes, Monier Sharif

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Infectious bronchitis virus (IBV) is a very dynamic and evolving virus which causing major economic losses to the global poultry industry. Recently, the Libyan poultry industry faced severe outbreak of respiratory distress associated with high mortality and dramatic drop in egg production. Tracheal and cloacal swabs were analyzed for several poultry viruses. IBV was detected using SYBR Green I real-time PCR detection based on the nucleocapsid (N) gene. Sequence analysis of the partial N gene indicated high similarity (~ 94%) to IBV strain 3382/06 that was isolated from Taiwan. Even though the IBV strain 3382/06 is more similar to that of the Mass type H120, the isolate has been implicated associated with intertypic recombinant of 3 putative parental IBV strains namely H120, Taiwan strain 1171/92 and China strain CK/CH/LDL/97I. Complete sequencing and antigenicity studies of the Libya IBV strains are currently underway to determine the evolution of the virus and its importance in vaccine induced immunity. In this paper, we documented for the first time the presence of possibly variant IBV strain from Libya which required a dramatic change in the vaccination program.

Keywords: Libya, infectious bronchitis, molecular characterization, viruses, vaccine

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1560 Real Interest Rates and Real Returns of Agricultural Commodities in the Context of Quantitative Easing

Authors: Wei Yao, Constantinos Alexiou

Abstract:

In the existing literature, many studies have focused on the implementation and effectiveness of quantitative easing (QE) since 2008, but only a few have evaluated QE’s effect on commodity prices. In this context, by following Frankel’s (1986) commodity price overshooting model, we study the dynamic covariation between the expected real interest rates and six agricultural commodities’ real returns over the period from 2000:1 to 2018 for the US economy. We use wavelet analysis to investigate the causal relationship and co-movement of time series data by calculating the coefficient of determination in different frequencies. We find that a) US unconventional monetary policy may cause more positive and significant covariation between the expected real interest rates and agricultural commodities’ real returns over the short horizons; b) a lead-lag relationship that runs from agricultural commodities’ real returns to the expected real short-term interest rates over the long horizons; and c) a lead-lag relationship from agricultural commodities’ real returns to the expected real long-term interest rates over short horizons. In the realm of monetary policy, we argue that QE may shift the negative relationship between most commodities’ real returns and the expected real interest rates to a positive one over a short horizon.

Keywords: QE, commodity price, interest rate, wavelet coherence

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1559 Vibration Control of Hermetic Compressors Using Flexible Multi-Body Dynamics Theory

Authors: Armin Amindari

Abstract:

Hermetic compressors are used widely for refrigeration, heat pump, and air conditioning applications. With the improvement of energy conservation and environmental protection requirements, inverter compressors that operates at different speeds have become increasingly attractive in the industry. Although speed change capability is more efficient, passing through resonant frequencies may lead to excessive vibrations. In this work, an integrated vibration control approach based on flexible multi-body dynamics theory is used for optimizing the vibration amplitudes of the compressor at different operating speeds. To examine the compressor vibrations, all the forces and moments exerted on the cylinder block were clarified and minimized using balancers attached to the upper and lower ends of the motor rotor and crankshaft. The vibration response of the system was simulated using Motionview™ software. In addition, mass-spring optimization was adopted to shift the resonant frequencies out of the operating speeds. The modal shapes of the system were studied using Optistruct™ solver. Using this approach, the vibrations were reduced up to 56% through dynamic simulations. The results were in high agreement with various experimental test data. In addition, the vibration resonance problem observed at low speeds was solved by shifting the resonant frequencies through optimization studies.

Keywords: vibration, MBD, compressor, hermetic

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1558 Tackling the Value-Action-Gap: Improving Civic Participation Using a Holistic Behavioral Model Approach

Authors: Long Pham, Julia Blanke

Abstract:

An increasingly popular way of establishing citizen engagement within communities is through ‘city apps’. Currently, most of these mobile applications seem to be extensions of the existing communication media, sometimes merely replicating the information available on the classical city web sites, and therefore provide minimal additional impact on citizen behavior and engagement. In order to overcome this challenge, we propose to use a holistic behavioral model to generate dynamic and contextualized app content based on optimizing well defined city-related performance goals constrained by the proposed behavioral model. In this paper, we will show how the data collected by the CorkCitiEngage project in the Irish city of Cork can be utilized to calibrate aspects of the proposed model enabling the design of a personalized citizen engagement app aiming at positively influencing people’s behavior towards more active participation in their communities. We will focus on the important aspect of intentions to act, which is essential for understanding the reasons behind the common value-action-gap being responsible for the mismatch between good intentions and actual observable behavior, and will discuss how customized app design can be based on a rigorous model of behavior optimized towards maximizing well defined city-related performance goals.

Keywords: city apps, holistic behaviour model, intention to act, value-action-gap, citizen engagement

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1557 Exploring the Activity Fabric of an Intelligent Environment with Hierarchical Hidden Markov Theory

Authors: Chiung-Hui Chen

Abstract:

The Internet of Things (IoT) was designed for widespread convenience. With the smart tag and the sensing network, a large quantity of dynamic information is immediately presented in the IoT. Through the internal communication and interaction, meaningful objects provide real-time services for users. Therefore, the service with appropriate decision-making has become an essential issue. Based on the science of human behavior, this study employed the environment model to record the time sequences and locations of different behaviors and adopted the probability module of the hierarchical Hidden Markov Model for the inference. The statistical analysis was conducted to achieve the following objectives: First, define user behaviors and predict the user behavior routes with the environment model to analyze user purposes. Second, construct the hierarchical Hidden Markov Model according to the logic framework, and establish the sequential intensity among behaviors to get acquainted with the use and activity fabric of the intelligent environment. Third, establish the intensity of the relation between the probability of objects’ being used and the objects. The indicator can describe the possible limitations of the mechanism. As the process is recorded in the information of the system created in this study, these data can be reused to adjust the procedure of intelligent design services.

Keywords: behavior, big data, hierarchical hidden Markov model, intelligent object

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1556 Organizational Agility in 22 Districts of Tehran Municipality

Authors: Mehrnoosh Jafari, Zeinolabedin Amini Sabegh, Habibollah Azimian

Abstract:

Background: Today variable and dynamic environment doubles importance of using suitable solutions for confronting these changes in th4e organizations. One of the best ways for coping with environmental changes is directing the organization towards agility. Current research aims at investigating status of organizational agility in Tehran municipality (22 districts). Research Methodology: This research is applied research in terms of purpose of study and it is survey in terms of collection of descriptive data. A sample (n = 377) was selected from Tehran Municipality (22 districts) employees using multistage sampling method (cluster and regular). Data were collected using organizational agility standard questionnaire, and they were analyzed using statistical tests in SPSS software as well as inferential statistics such as one-sample t-test and Friedman test and descriptive statistics such as mean and median. Findings: Research findings showed organizational agility status in the organizations under study is in relatively optimal status and competence has highest priority in terms of ranking and priority of organizational agility indexes. Conclusion: It is necessary that managers provide suitable conditions for promoting organizational agility status in the organizations under study by identifying factors affecting change in the organizational environments and using available potentials for better coping with changes and higher flexibility and speed.

Keywords: organizational, municipality, employer, agility

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1555 Vertical Accuracy Evaluation of Indian National DEM (CartoDEM v3) Using Dual Frequency GNSS Derived Ground Control Points for Lower Tapi Basin, Western India

Authors: Jaypalsinh B. Parmar, Pintu Nakrani, Ashish Chaurasia

Abstract:

Digital Elevation Model (DEM) is considered as an important data in GIS-based terrain analysis for many applications and assessment of processes such as environmental and climate change studies, hydrologic modelling, etc. Vertical accuracy of DEM having geographically dynamic nature depends on different parameters which affect the model simulation outcomes. Vertical accuracy assessment in Indian landscape especially in low-lying coastal urban terrain such as lower Tapi Basin is very limited. In the present study, attempt has been made to evaluate the vertical accuracy of 30m resolution open source Indian National Cartosat-1 DEM v3 for Lower Tapi Basin (LTB) from western India. The extensive field investigation is carried out using stratified random fast static DGPS survey in the entire study region, and 117 high accuracy ground control points (GCPs) have been obtained. The above open source DEM was compared with obtained GCPs, and different statistical attributes were envisaged, and vertical error histograms were also evaluated.

Keywords: CartoDEM, Digital Elevation Model, GPS, lower Tapi basin

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1554 Control of an Asymmetrical Design of a Pneumatically Actuated Ambidextrous Robot Hand

Authors: Emre Akyürek, Anthony Huynh, Tatiana Kalganova

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The Ambidextrous Robot Hand is a robotic device with the purpose to mimic either the gestures of a right or a left hand. The symmetrical behavior of its fingers allows them to bend in one way or another keeping a compliant and anthropomorphic shape. However, in addition to gestures they can reproduce on both sides, an asymmetrical mechanical design with a three tendons routing has been engineered to reduce the number of actuators. As a consequence, control algorithms must be adapted to drive efficiently the ambidextrous fingers from one position to another and to include grasping features. These movements are controlled by pneumatic muscles, which are nonlinear actuators. As their elasticity constantly varies when they are under actuation, the length of pneumatic muscles and the force they provide may differ for a same value of pressurized air. The control algorithms introduced in this paper take both the fingers asymmetrical design and the pneumatic muscles nonlinearity into account to permit an accurate control of the Ambidextrous Robot Hand. The finger motion is achieved by combining a classic PID controller with a phase plane switching control that turns the gain constants into dynamic values. The grasping ability is made possible because of a sliding mode control that makes the fingers adapt to the shape of an object before strengthening their positions.

Keywords: ambidextrous hand, intelligent algorithms, nonlinear actuators, pneumatic muscles, robotics, sliding control

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1553 Effect of Planting Techniques on Mangrove Seedling Establishment in Kuwait Bay

Authors: L. Al-Mulla, B. M. Thomas, N. R. Bhat, M. K. Suleiman, P. George

Abstract:

Mangroves are halophytic shrubs habituated in the intertidal zones in the tropics and subtropics, forming a complex and highly dynamic coastal ecosystem. Historical evidence indicating the existence followed by the extinction of mangrove in Kuwait; hence, continuous projects have been established to reintroduce this plant to the marine ecosystem. One of the major challenges in establishing large-scale mangrove plantations in Kuwait is the very high rate of seedling mortality, which should ideally be less than 20%. This study was conducted at three selected locations in the Kuwait bay during 2016-2017, to evaluate the effect of four planting techniques on mangrove seedling establishment. Coir-pillow planting technique, comp-mat planting technique, and anchored container planting technique were compared with the conventional planting method. The study revealed that the planting techniques significantly affected the establishment of mangrove seedlings in the initial stages of growth. Location-specific difference in seedling establishment was also observed during the course of the study. However, irrespective of the planting techniques employed, high seedling mortality was observed in all the planting locations towards the end of the study; which may be attributed to the physicochemical characteristics of the mudflats selected.

Keywords: Avicennia marina (Forsk.) Vierh, coastal pollution, heavy metal accumulation, marine ecosystem, sedimentation, tidal inundation

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1552 Effect of Traffic Volume and Its Composition on Vehicular Speed under Mixed Traffic Conditions: A Kriging Based Approach

Authors: Subhadip Biswas, Shivendra Maurya, Satish Chandra, Indrajit Ghosh

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Use of speed prediction models sometimes appears as a feasible alternative to laborious field measurement particularly, in case when field data cannot fulfill designer’s requirements. However, developing speed models is a challenging task specifically in the context of developing countries like India where vehicles with diverse static and dynamic characteristics use the same right of way without any segregation. Here the traffic composition plays a significant role in determining the vehicular speed. The present research was carried out to examine the effects of traffic volume and its composition on vehicular speed under mixed traffic conditions. Classified traffic volume and speed data were collected from different geometrically identical six lane divided arterials in New Delhi. Based on these field data, speed prediction models were developed for individual vehicle category adopting Kriging approximation technique, an alternative for commonly used regression. These models are validated with the data set kept aside earlier for validation purpose. The predicted speeds showed a great deal of agreement with the observed values and also the model outperforms all other existing speed models. Finally, the proposed models were utilized to evaluate the effect of traffic volume and its composition on speed.

Keywords: speed, Kriging, arterial, traffic volume

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1551 Indian Road Traffic Flow Analysis Using Blob Tracking from Video Sequences

Authors: Balaji Ganesh Rajagopal, Subramanian Appavu alias Balamurugan, Ayyalraj Midhun Kumar, Krishnan Nallaperumal

Abstract:

Intelligent Transportation System is an Emerging area to solve multiple transportation problems. Several forms of inputs are needed in order to solve ITS problems. Advanced Traveler Information System (ATIS) is a core and important ITS area of this modern era. This involves travel time forecasting, efficient road map analysis and cost based path selection, Detection of the vehicle in the dynamic conditions and Traffic congestion state forecasting. This Article designs and provides an algorithm for traffic data generation which can be used for the above said ATIS application. By inputting the real world traffic situation in the form of video sequences, the algorithm determines the Traffic density in terms of congestion, number of vehicles in a given path which can be fed for various ATIS applications. The Algorithm deduces the key frame from the video sequences and follows the Blob detection, Identification and Tracking using connected components algorithm to determine the correlation between the vehicles moving in the real road scene.

Keywords: traffic transportation, traffic density estimation, blob identification and tracking, relative velocity of vehicles, correlation between vehicles

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1550 Improving Seat Comfort by Semi-Active Control of Magnetorheological Damper

Authors: Karel Šebesta, Jiří Žáček, Matuš Salva, Mohammad Housam

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Drivers of agricultural vehicles are exposed to continuous vibration caused by driving over rough terrain. The long-term effects of these vibrations could start with a decreased level of vigilance at work and could reach the level of several health problems. Therefore, eliminating the vibration to maximize the comfort of the driver is essential for better/longer performance. One of the modern damping systems, which can deal with this problem is the Semi-active (S/A) suspension system featuring a Magnetorheological (MR) damper. With this damper, the damping level can be adjusted using varying currents through the coil. Adjustments of the damping force can be carried out continuously based on the evaluated data (position and acceleration of seat) by the control algorithm. The advantage of this system is the wide dynamic range and the high speed of force response time. Compared to other S/A or active systems, the MR damper does not need as much electrical power, and the system is much simpler. This paper aims to prove the effectiveness of this damping system used in the tractor seat. The vibration testing stand was designed and manufactured specifically for this type of research, which is used to simulate vibrations with constant amplitude at variable frequency.

Keywords: magnetorheological damper, semi-active suspension, seat scissor mechanism, sky-hook

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1549 Experimental and Numerical Investigations of Impact Response on High-Speed Train Windshield

Authors: Wen Ma, Yong Peng, Zhixiang Li

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Security journey is a vital focus on the field of Rail Transportation. Accidents caused by the damage of the high-speed train windshield have occurred many times and have given rise to terrible consequences. Train windshield consists of tempered glass and polyvinyl butyral (PVB) film. In this work, the quasi-static tests and the split Hopkinson pressure bar (SHPB) tests were carried out first to obtain the mechanical properties and constitutive model for the tempered glass and PVB film. These tests results revealed that stress and Young’s modulus of tempered glass were wake-sensitive to strain rate, but stress and Young’s modulus of PVB film were strong-sensitive to strain rate. Then impact experiment of the windshield was carried out to investigate dynamic response and failure characteristics of train windshield. In addition, a finite element model based on the combined finite element method was proposed to investigate fracture and fragmentation responses of train windshield under different-velocity impact. The results can be used for further design and optimization of the windshield for high-speed train application.

Keywords: constitutive model, impact response, mechanism properties, PVB film, tempered glass

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1548 Developing a Simulation-Based Optimization Framework to Perform Energy Simulation for Indian Buildings

Authors: Sujoy Anirudha Das, Albert Thomas

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Building sector is a major consumer of energy globally, and it has corresponding effects to the environment with respect to the carbon emissions. Given the fact that India is expected to add 40-billion square meter of new buildings till 2050, we need frameworks that help in reducing the overall energy consumption in the building sector. Even though several simulation-based frameworks that help in analyzing the building energy consumption are developed globally, in the Indian context, to the best of our knowledge, there is a lack of a comprehensive, yet user-friendly framework to simulate and optimize the effects of various energy influencing factors, specifically for Indian buildings. Therefore, this study is aimed at developing a simulation-based optimization framework to model the energy interactions in different types of Indian buildings by considering the dynamic nature of various energy influencing factors. This comprehensive framework can be used by various building stakeholders to test the energy effects of different factors such as, but not limited to, the various building materials, the orientation, the weather fluctuations, occupancy changes and the type of the building (e.g., office, residential). The results from the case study involving several building types would help us in gaining insights to build new energy-efficient buildings as well as retrofit the existing structures in a more convenient way to consume less energy, exclusively for an Indian scenario.

Keywords: building energy consumption, building energy simulations, energy efficient buildings, optimization framework

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1547 Real-Time Path Planning for Unmanned Air Vehicles Using Improved Rapidly-Exploring Random Tree and Iterative Trajectory Optimization

Authors: A. Ramalho, L. Romeiro, R. Ventura, A. Suleman

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A real-time path planning framework for Unmanned Air Vehicles, and in particular multi-rotors is proposed. The framework is designed to provide feasible trajectories from the current UAV position to a goal state, taking into account constraints such as obstacle avoidance, problem kinematics, and vehicle limitations such as maximum speed and maximum acceleration. The framework computes feasible paths online, allowing to avoid new, unknown, dynamic obstacles without fully re-computing the trajectory. These features are achieved using an iterative process in which the robot computes and optimizes the trajectory while performing the mission objectives. A first trajectory is computed using a modified Rapidly-Exploring Random Tree (RRT) algorithm, that provides trajectories that respect a maximum curvature constraint. The trajectory optimization is accomplished using the Interior Point Optimizer (IPOPT) as a solver. The framework has proven to be able to compute a trajectory and optimize to a locally optimal with computational efficiency making it feasible for real-time operations.

Keywords: interior point optimization, multi-rotors, online path planning, rapidly exploring random trees, trajectory optimization

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1546 Analyzing the Effects of Supply and Demand Shocks in the Spanish Economy

Authors: José M Martín-Moreno, Rafaela Pérez, Jesús Ruiz

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In this paper we use a small open economy Dynamic Stochastic General Equilibrium Model (DSGE) for the Spanish economy to search for a deeper characterization of the determinants of Spain’s macroeconomic fluctuations throughout the period 1970-2008. In order to do this, we distinguish between tradable and non-tradable goods to take into account the fact that the presence of non-tradable goods in this economy is one of the largest in the world. We estimate a DSGE model with supply and demand shocks (sectorial productivity, public spending, international real interest rate and preferences) using Kalman Filter techniques. We find the following results. First of all, our variance decomposition analysis suggests that 1) the preference shock basically accounts for private consumption volatility, 2) the idiosyncratic productivity shock accounts for non-tradable output volatility, and 3) the sectorial productivity shock along with the international interest rate both greatly account for tradable output. Secondly, the model closely replicates the time path observed in the data for the Spanish economy and finally, the model captures the main cyclical qualitative features of this economy reasonably well.

Keywords: business cycle, DSGE models, Kalman filter estimation, small open economy

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1545 A Simulation-Optimization Approach to Control Production, Subcontracting and Maintenance Decisions for a Deteriorating Production System

Authors: Héctor Rivera-Gómez, Eva Selene Hernández-Gress, Oscar Montaño-Arango, Jose Ramon Corona-Armenta

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This research studies the joint production, maintenance and subcontracting control policy for an unreliable deteriorating manufacturing system. Production activities are controlled by a derivation of the Hedging Point Policy, and given that the system is subject to deterioration, it reduces progressively its capacity to satisfy product demand. Multiple deterioration effects are considered, reflected mainly in the quality of the parts produced and the reliability of the machine. Subcontracting is available as support to satisfy product demand; also overhaul maintenance can be conducted to reduce the effects of deterioration. The main objective of the research is to determine simultaneously the production, maintenance and subcontracting rate which minimize the total incurred cost. A stochastic dynamic programming model is developed and solved through a simulation-based approach composed of statistical analysis and optimization with the response surface methodology. The obtained results highlight the strong interactions between production, deterioration and quality which justify the development of an integrated model. A numerical example and a sensitivity analysis are presented to validate our results.

Keywords: subcontracting, optimal control, deterioration, simulation, production planning

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1544 Coastal Environment: Statistical Analysis and Geomorphic Impact on Urban Tourism in Lagos, Portugal

Authors: Magdalena Kuleta

Abstract:

Ponta de Piedade (37º05 ' N, 08º40 ' W) is an area located in the southern part of the Lagos municipality, which include an abrasive and accumulative type of coastline. It is the one of the main touristic destinations of the city. The dynamic development of the attractiveness of the coast, is related with the expansion of the new tourism infrastructure and urban tourism products. These products are: transportation, sightseeing and entertainment in the form of the boat trips. Each type of excursion refers to the different product. This progress brings also many risks associated primarily with landslides cliffs. Natural conditions affecting the coast, create a huge impact on the evolution of urban tourism management. Based on observation, statistical analysis and survey method, author compare the period of six years from 2012 to 2016 in terms of the number of tourists, number and diversity of attractions, most frequently dialled products and infrastructure changes in the city. Carried methodology is based on data belonging to Turismo Portugal and the tourist company Days of Adventure. Main result, is to indicate the essence of the income from coastal tourism into the city development and how does it influence on the marketing and promoting of urban tourism in Lagos.

Keywords: geomorphology of the coast in Lagos, market and promotion, quality of tourism service, urban tourism products

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1543 Analysis of Brain Signals Using Neural Networks Optimized by Co-Evolution Algorithms

Authors: Zahra Abdolkarimi, Naser Zourikalatehsamad,

Abstract:

Up to 40 years ago, after recognition of epilepsy, it was generally believed that these attacks occurred randomly and suddenly. However, thanks to the advance of mathematics and engineering, such attacks can be predicted within a few minutes or hours. In this way, various algorithms for long-term prediction of the time and frequency of the first attack are presented. In this paper, by considering the nonlinear nature of brain signals and dynamic recorded brain signals, ANFIS model is presented to predict the brain signals, since according to physiologic structure of the onset of attacks, more complex neural structures can better model the signal during attacks. Contribution of this work is the co-evolution algorithm for optimization of ANFIS network parameters. Our objective is to predict brain signals based on time series obtained from brain signals of the people suffering from epilepsy using ANFIS. Results reveal that compared to other methods, this method has less sensitivity to uncertainties such as presence of noise and interruption in recorded signals of the brain as well as more accuracy. Long-term prediction capacity of the model illustrates the usage of planted systems for warning medication and preventing brain signals.

Keywords: co-evolution algorithms, brain signals, time series, neural networks, ANFIS model, physiologic structure, time prediction, epilepsy suffering, illustrates model

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1542 Molecular Dynamics Simulation for Buckling Analysis at Nanocomposite Beams

Authors: Babak Safaei, A. M. Fattahi

Abstract:

In the present study we have investigated axial buckling characteristics of nanocomposite beams reinforced by single-walled carbon nanotubes (SWCNTs). Various types of beam theories including Euler-Bernoulli beam theory, Timoshenko beam theory and Reddy beam theory were used to analyze the buckling behavior of carbon nanotube-reinforced composite beams. Generalized differential quadrature (GDQ) method was utilized to discretize the governing differential equations along with four commonly used boundary conditions. The material properties of the nanocomposite beams were obtained using molecular dynamic (MD) simulation corresponding to both short-(10,10) SWCNT and long-(10,10) SWCNT composites which were embedded by amorphous polyethylene matrix. Then the results obtained directly from MD simulations were matched with those calculated by the mixture rule to extract appropriate values of carbon nanotube efficiency parameters accounting for the scale-dependent material properties. The selected numerical results were presented to indicate the influences of nanotube volume fractions and end supports on the critical axial buckling loads of nanocomposite beams relevant to long- and short-nanotube composites.

Keywords: nanocomposites, molecular dynamics simulation, axial buckling, generalized differential quadrature (GDQ)

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1541 Teachers’ Language Insecurity in English as a Second Language Instruction: Developing Effective In-Service Training

Authors: Mamiko Orii

Abstract:

This study reports on primary school second language teachers’ sources of language insecurity. Furthermore, it aims to develop an in-service training course to reduce anxiety and build sufficient English communication skills. Language/Linguistic insecurity refers to a lack of confidence experienced by language speakers. In particular, second language/non-native learners often experience insecurity, influencing their learning efficacy. While language learner insecurity has been well-documented, research on the insecurity of language teaching professionals is limited. Teachers’ language insecurity or anxiety in target language use may adversely affect language instruction. For example, they may avoid classroom activities requiring intensive language use. Therefore, understanding teachers’ language insecurity and providing continuing education to help teachers to improve their proficiency is vital to improve teaching quality. This study investigated Japanese primary school teachers’ language insecurity. In Japan, teachers are responsible for teaching most subjects, including English, which was recently added as compulsory. Most teachers have never been professionally trained in second language instruction during college teacher certificate preparation, leading to low confidence in English teaching. Primary source of language insecurity is a lack of confidence regarding English communication skills. Their actual use of English in classrooms remains unclear. Teachers’ classroom speech remains a neglected area requiring improvement. A more refined programme for second language teachers could be constructed if we can identify areas of need. Two questionnaires were administered to primary school teachers in Tokyo: (1) Questionnaire A: 396 teachers answered questions (using a 5-point scale) concerning classroom teaching anxiety and general English use and needs for in-service training (Summer 2021); (2) Questionnaire B: 20 teachers answered detailed questions concerning their English use (Autumn 2022). Questionnaire A’s responses showed that over 80% of teachers have significant language insecurity and anxiety, mainly when speaking English in class or teaching independently. Most teachers relied on a team-teaching partner (e.g., ALT) and avoided speaking English. Over 70% of the teachers said they would like to participate in training courses in classroom English. Questionnaire B’s results showed that teachers could use simple classroom English, such as greetings and basic instructions (e.g., stand up, repeat after me), and initiate conversation (e.g., asking questions). In contrast, teachers reported that conversations were mainly carried on in a simple question-answer style. They had difficulty continuing conversations. Responding to learners’ ‘on-the-spot’ utterances was particularly difficult. Instruction in turn-taking patterns suitable in the classroom communication context is needed. Most teachers received grammar-based instruction during their entire English education. They were predominantly exposed to displayed questions and form-focused corrective feedback. Therefore, strategies such as encouraging teachers to ask genuine questions (i.e., referential questions) and responding to students with content feedback are crucial. When learners’ utterances are incorrect or unsatisfactory, teachers should rephrase or extend (recast) them instead of offering explicit corrections. These strategies support a continuous conversational flow. These results offer benefits beyond Japan’s English as a second Language context. They will be valuable in any context where primary school teachers are underprepared but must provide English-language instruction.

Keywords: english as a second/non-native language, in-service training, primary school, teachers’ language insecurity

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1540 An Optimal Approach for Full-Detailed Friction Model Identification of Reaction Wheel

Authors: Ghasem Sharifi, Hamed Shahmohamadi Ousaloo, Milad Azimi, Mehran Mirshams

Abstract:

The ever-increasing use of satellites demands a search for increasingly accurate and reliable pointing systems. Reaction wheels are rotating devices used commonly for the attitude control of the spacecraft since provide a wide range of torque magnitude and high reliability. The numerical modeling of this device can significantly enhance the accuracy of the satellite control in space. Modeling the wheel rotation in the presence of the various frictions is one of the critical parts of this approach. This paper presents a Dynamic Model Control of a Reaction Wheel (DMCR) in the current control mode. In current-mode, the required current is delivered to the coils in order to achieve the desired torque. During this research, all the friction parameters as viscous and coulomb, motor coefficient, resistance and voltage constant are identified. In order to model identification of a reaction wheel, numerous varying current commands apply on the particular wheel to verify the estimated model. All the parameters of DMCR are identified by classical Levenberg-Marquardt (CLM) optimization method. The experimental results demonstrate that the developed model has an appropriate precise and can be used in the satellite control simulation.

Keywords: experimental modeling, friction parameters, model identification, reaction wheel

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1539 Behind Egypt’s Financial Crisis: Dollarization

Authors: Layal Mansour

Abstract:

This paper breaks down Egypt’s financial crisis by constructing a customized financial stress index by including the vulnerable economic indicator “dollarization” as a vulnerable indicator in the credit and exchange sector. The Financial Stress Index for Egypt (FSIE) includes informative vulnerable indicators of the main financial sectors: the banking sector, the equities market, and the foreign exchange market. It is calculated on a monthly basis from 2010 to December 2022, so to report the two recent world’s most devastating financial crises: Covid 19 crisis and Ukraine-Russia War, in addition to the local 2016 and 2022 financial crises. We proceed first by a graphical analysis then by empirical analysis in running under Vector Autoregression (VAR) Model, dynamic causality tests between foreign reserves, dollarization rate, and FSIE. The graphical analysis shows that unexpectedly, Egypt’s economy seems to be immune to internal economic/political instabilities, however it is highly exposed to the foreign and exchange market. Empirical analysis confirms the graphical observations and proves that dollarization, or more precisely debt in foreign currency seems to be the main trigger of Egypt’s current financial crisis.

Keywords: egypt, financial crisis, financial stress index, dollarization, VAR model, causality tests

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1538 Aircraft Automatic Collision Avoidance Using Spiral Geometric Approach

Authors: M. Orefice, V. Di Vito

Abstract:

This paper provides a description of a Collision Avoidance algorithm that has been developed starting from the mathematical modeling of the flight of insects, in terms of spirals and conchospirals geometric paths. It is able to calculate a proper avoidance manoeuver aimed to prevent the infringement of a predefined distance threshold between ownship and the considered intruder, while minimizing the ownship trajectory deviation from the original path and in compliance with the aircraft performance limitations and dynamic constraints. The algorithm is designed in order to be suitable for real-time applications, so that it can be considered for the implementation in the most recent airborne automatic collision avoidance systems using the traffic data received through an ADS-B IN device. The presented approach is able to take into account the rules-of-the-air, due to the possibility to select, through specifically designed decision making logic based on the consideration of the encounter geometry, the direction of the calculated collision avoidance manoeuver that allows complying with the rules-of-the-air, as for instance the fundamental right of way rule. In the paper, the proposed collision avoidance algorithm is presented and its preliminary design and software implementation is described. The applicability of this method has been proved through preliminary simulation tests performed in a 2D environment considering single intruder encounter geometries, as reported and discussed in the paper.

Keywords: ADS-B Based Application, Collision Avoidance, RPAS, Spiral Geometry.

Procedia PDF Downloads 228