Search results for: simulated concrete pore solution (SPS)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9115

Search results for: simulated concrete pore solution (SPS)

1525 Study of Efficiency of Flying Animal Using Computational Simulation

Authors: Ratih Julistina, M. Agoes Moelyadi

Abstract:

Innovation in aviation technology evolved rapidly by time to time for acquiring the most favorable value of utilization and is usually denoted by efficiency parameter. Nature always become part of inspiration, and for this sector, many researchers focused on studying the behavior of flying animal to comprehend the fundamental, one of them is birds. Experimental testing has already conducted by several researches to seek and calculate the efficiency by putting the object in wind tunnel. Hence, computational simulation is needed to conform the result and give more visualization which is based on Reynold Averaged Navier-Stokes equation solution for unsteady case in time-dependent viscous flow. By creating model from simplification of the real bird as a rigid body, those are Hawk which has low aspect ratio and Swift with high aspect ratio, subsequently generating the multi grid structured mesh to capture and calculate the aerodynamic behavior and characteristics. Mimicking the motion of downstroke and upstroke of bird flight which produced both lift and thrust, the sinusoidal function is used. Simulation is carried out for varied of flapping frequencies within upper and lower range of actual each bird’s frequency which are 1 Hz, 2.87 Hz, 5 Hz for Hawk and 5 Hz, 8.9 Hz, 13 Hz for Swift to investigate the dependency of frequency effecting the efficiency of aerodynamic characteristics production. Also, by comparing the result in different condition flights with the morphology of each bird. Simulation has shown that higher flapping frequency is used then greater aerodynamic coefficient is obtained, on other hand, efficiency on thrust production is not the same. The result is analyzed from velocity and pressure contours, mesh movement as to see the behavior.

Keywords: characteristics of aerodynamic, efficiency, flapping frequency, flapping wing, unsteady simulation

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1524 Investigation of Software Integration for Simulations of Buoyancy-Driven Heat Transfer in a Vehicle Underhood during Thermal Soak

Authors: R. Yuan, S. Sivasankaran, N. Dutta, K. Ebrahimi

Abstract:

This paper investigates the software capability and computer-aided engineering (CAE) method of modelling transient heat transfer process occurred in the vehicle underhood region during vehicle thermal soak phase. The heat retention from the soak period will be beneficial to the cold start with reduced friction loss for the second 14°C worldwide harmonized light-duty vehicle test procedure (WLTP) cycle, therefore provides benefits on both CO₂ emission reduction and fuel economy. When vehicle undergoes soak stage, the airflow and the associated convective heat transfer around and inside the engine bay is driven by the buoyancy effect. This effect along with thermal radiation and conduction are the key factors to the thermal simulation of the engine bay to obtain the accurate fluids and metal temperature cool-down trajectories and to predict the temperatures at the end of the soak period. Method development has been investigated in this study on a light-duty passenger vehicle using coupled aerodynamic-heat transfer thermal transient modelling method for the full vehicle under 9 hours of thermal soak. The 3D underhood flow dynamics were solved inherently transient by the Lattice-Boltzmann Method (LBM) method using the PowerFlow software. This was further coupled with heat transfer modelling using the PowerTHERM software provided by Exa Corporation. The particle-based LBM method was capable of accurately handling extremely complicated transient flow behavior on complex surface geometries. The detailed thermal modelling, including heat conduction, radiation, and buoyancy-driven heat convection, were integrated solved by PowerTHERM. The 9 hours cool-down period was simulated and compared with the vehicle testing data of the key fluid (coolant, oil) and metal temperatures. The developed CAE method was able to predict the cool-down behaviour of the key fluids and components in agreement with the experimental data and also visualised the air leakage paths and thermal retention around the engine bay. The cool-down trajectories of the key components obtained for the 9 hours thermal soak period provide vital information and a basis for the further development of reduced-order modelling studies in future work. This allows a fast-running model to be developed and be further imbedded with the holistic study of vehicle energy modelling and thermal management. It is also found that the buoyancy effect plays an important part at the first stage of the 9 hours soak and the flow development during this stage is vital to accurately predict the heat transfer coefficients for the heat retention modelling. The developed method has demonstrated the software integration for simulating buoyancy-driven heat transfer in a vehicle underhood region during thermal soak with satisfying accuracy and efficient computing time. The CAE method developed will allow integration of the design of engine encapsulations for improving fuel consumption and reducing CO₂ emissions in a timely and robust manner, aiding the development of low-carbon transport technologies.

Keywords: ATCT/WLTC driving cycle, buoyancy-driven heat transfer, CAE method, heat retention, underhood modeling, vehicle thermal soak

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1523 Multidimensional Inequality and Deprivation Among Tribal Communities of Andhra Pradesh, India

Authors: Sanjay Sinha, Mohd Umair Khan

Abstract:

The level of income inequality in India has been worrisome as the World Inequality Report termed it as a “poor and unequal country, with an affluent elite”. As important as income is to understand inequality and deprivation, it is just one dimension. But the historical roots and current realities of inequality and deprivation in India lies in many of the non-income dimensions such as housing, nutrition, education, agency, sense of inclusion etc. which are often ignored, especially in solution-oriented research. The level of inequality and deprivation among the tribal is one such case. There is a corpus of literature establishing that the tribal communities in India are disadvantageous on various grounds. Given their rural geography, issues of access and quality of basic facilities such as education and healthcare are often unaddressed. COVID-19 has further exacerbated this challenge and climate change will make it even more worrying. With this background, a succinct measurement tool at the village level is necessary to design short to medium-term actions with reference to risk mitigation for tribal communities. This research paper examines the level of inequality and deprivation among the tribal communities in the rural areas of Andhra Pradesh state of India using a Multidimensional Inequality and Deprivation Index based on the Alkire-Foster methodology. The methodology is theoretically grounded in the capability approach propounded by Amartya Sen, emphasizing on achieving the “beings and doings” (functionings) an individual reason to value. In the index, the authors have five domains, including Livelihood, Food Security, Education, Health and Housing and these domains are divided into sixteen indicators. This assessment is followed by domain-wise short-term and long-term solutions.

Keywords: Andhra Pradesh, Alkire-Foster methodology, deprivation, inequality, multidimensionality, poverty, tribal

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1522 Structural Evolution of Electrodeposited Ni Coating on Ti-6Al-4V Alloy during Heat Treatment

Authors: M. Abdoos, A. Amadeh, M. Adabi

Abstract:

In recent decades, the use of titanium and its alloys due to their high mechanical properties, light weight and their corrosion resistance has increased in military and industry applications. However, the poor surface properties can limit their widely usage. Many researches were carried out to improve their surface properties. The most effective technique is based on solid-state diffusion of elements that can form intermetallic compounds with the substrate. In the present work, inter-diffusion of nickel and titanium and formation of Ni-Ti intermetallic compounds in nickel-coated Ti-6Al-4V alloy have been studied. Initially, nickel was electrodeposited on the alloy using Watts bath at a current density of 20 mA/cm2 for 1 hour. The coated specimens were then heat treated in a tubular furnace under argon atmosphere at different temperatures near Ti β-transus to maximize the diffusion rate for various durations in order to improve the surface properties of the Ti-6Al-4V alloy. The effect of temperature and time on the thickness of diffusion layer and characteristics of intermetallic phases was studied by means of scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and microhardness test. The results showed that a multilayer structure was formed after heat treatment: an outer layer of remaining nickel, an area of intermetallic layers with different compositions and solid solution of Ni-Ti. Three intermetallic layers was detected by EDS analysis, namely an outer layer with about 75 at.% Ni (Ni3Ti), an intermediate layer with 50 at.% Ni (NiTi) and finally an inner layer with 36 at.% Ni (NiTi2). It was also observed that the increase in time or temperature led to the formation of thicker intermetallic layers. Meanwhile, the microhardness of heat treated samples increased with formation of Ni-Ti intermetallics; however, its value depended on heat treatment parameters.

Keywords: heat treatment, microhardness, Ni coating, Ti-6Al-4V

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1521 Computational Intelligence and Machine Learning for Urban Drainage Infrastructure Asset Management

Authors: Thewodros K. Geberemariam

Abstract:

The rapid physical expansion of urbanization coupled with aging infrastructure presents a unique decision and management challenges for many big city municipalities. Cities must therefore upgrade and maintain the existing aging urban drainage infrastructure systems to keep up with the demands. Given the overall contribution of assets to municipal revenue and the importance of infrastructure to the success of a livable city, many municipalities are currently looking for a robust and smart urban drainage infrastructure asset management solution that combines management, financial, engineering and technical practices. This robust decision-making shall rely on sound, complete, current and relevant data that enables asset valuation, impairment testing, lifecycle modeling, and forecasting across the multiple asset portfolios. On this paper, predictive computational intelligence (CI) and multi-class machine learning (ML) coupled with online, offline, and historical record data that are collected from an array of multi-parameter sensors are used for the extraction of different operational and non-conforming patterns hidden in structured and unstructured data to determine and produce actionable insight on the current and future states of the network. This paper aims to improve the strategic decision-making process by identifying all possible alternatives; evaluate the risk of each alternative, and choose the alternative most likely to attain the required goal in a cost-effective manner using historical and near real-time urban drainage infrastructure data for urban drainage infrastructures assets that have previously not benefited from computational intelligence and machine learning advancements.

Keywords: computational intelligence, machine learning, urban drainage infrastructure, machine learning, classification, prediction, asset management space

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1520 A Multi-Stage Learning Framework for Reliable and Cost-Effective Estimation of Vehicle Yaw Angle

Authors: Zhiyong Zheng, Xu Li, Liang Huang, Zhengliang Sun, Jianhua Xu

Abstract:

Yaw angle plays a significant role in many vehicle safety applications, such as collision avoidance and lane-keeping system. Although the estimation of the yaw angle has been extensively studied in existing literature, it is still the main challenge to simultaneously achieve a reliable and cost-effective solution in complex urban environments. This paper proposes a multi-stage learning framework to estimate the yaw angle with a monocular camera, which can deal with the challenge in a more reliable manner. In the first stage, an efficient road detection network is designed to extract the road region, providing a highly reliable reference for the estimation. In the second stage, a variational auto-encoder (VAE) is proposed to learn the distribution patterns of road regions, which is particularly suitable for modeling the changing patterns of yaw angle under different driving maneuvers, and it can inherently enhance the generalization ability. In the last stage, a gated recurrent unit (GRU) network is used to capture the temporal correlations of the learned patterns, which is capable to further improve the estimation accuracy due to the fact that the changes of deflection angle are relatively easier to recognize among continuous frames. Afterward, the yaw angle can be obtained by combining the estimated deflection angle and the road direction stored in a roadway map. Through effective multi-stage learning, the proposed framework presents high reliability while it maintains better accuracy. Road-test experiments with different driving maneuvers were performed in complex urban environments, and the results validate the effectiveness of the proposed framework.

Keywords: gated recurrent unit, multi-stage learning, reliable estimation, variational auto-encoder, yaw angle

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1519 Evaluation of Egg Quality Parameters in the Isa Brown Line in Intensive Production Systems in the Ocaña Region, Norte de Santander

Authors: Meza-Quintero Myriam, Lobo Torrado Katty Andrea, Sanchez Picon Yesenia, Hurtado-Lugo Naudin

Abstract:

The objective of the study was to evaluate the internal and external quality of the egg in the three production housing systems: floor, cage, and grazing of laying birds of the Isa Brown line, in the laying period between weeks 35 to 41; 135 hens distributed in 3 treatments of 45 birds per repetition were used (the replicas were the seven weeks of the trial). The feeding treatment supplied in the floor and cage systems contained 114 g/bird/day; for the grazing system, 14 grams less concentrate was provided. Nine eggs were collected to be studied and analyzed in the animal nutrition laboratory (3 eggs per housing system). The random statistical model was implemented: for the statistical analysis of the data, the statistical software of IBM® Statistical Products and Services Solution (SPSS) version 2.3 was used. The evaluation and follow-up instruments were the vernier caliper for the measurement in millimeters, a YolkFan™16 from Roche DSM for the evaluation of the egg yolk pigmentation, a digital scale for the measurement in grams, a micrometer for the measurement in millimeters and evaluation in the laboratory using dry matter, ashes, and ethereal extract. The results suggested that equivalent to the size of the egg (0.04 ± 3.55) and the thickness of the shell (0.46 ± 3.55), where P-Value> 0.05 was obtained, weight albumen (0.18 ± 3.55), albumen height (0.38 ± 3.55), yolk weight (0.64 ± 3.55), yolk height (0.54 ± 3.55) and for yolk pigmentation (1.23 ± 3.55). It was concluded that the hens in the three production systems, floor, cage, and grazing, did not show significant statistical differences in the internal and external quality of the chicken in the parameters studied egg for the production system.

Keywords: biological, territories, genetic resource, egg

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1518 Impact of an Instructional Design Model in a Mathematics Game for Enhancing Students’ Motivation in Developing Countries

Authors: Shafaq Rubab

Abstract:

One of the biggest reasons of dropouts from schools is lack of motivation and interest among the students, particularly in mathematics. Many developing countries are facing this problem and this issue is lowering the literacy rate in these developing countries. The best solution for increasing motivation level and interest among the students is using tablet game-based learning. However, a pedagogically sound game required a well-planned instructional design model to enhance learner’s attention and confidence otherwise effectiveness of the learning games suffers badly. This research aims to evaluate the impact of the pedagogically sound instructional design model on students’ motivation by using tablet game-based learning. This research was conducted among the out-of-school-students having an age range from 7 to 12 years and the sample size of two hundred students was purposively selected without any gender discrimination. Qualitative research was conducted by using a survey tool named Instructional Material Motivational Survey (IMMS) adapted from Keller Arcs model. A comparison of results from both groups’ i.e. experimental group and control group revealed that motivation level of the students taught by the game was higher than the students instructed by using conventional methodologies. Experimental group’s students were more attentive, confident and satisfied as compared to the control group’s students. This research work not only promoted the trend of digital game-based learning in developing countries but also supported that a pedagogically sound instructional design model utilized in an educational game can increase the motivation level of the students and can make the learning process a totally immersive and interactive fun loving activity.

Keywords: digital game-based learning, student’s motivation, instructional design model, learning process

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1517 In a Situation of Great Distress: Cross Border Migration and the Quest for Enduring Security in North-East Nigeria

Authors: Nuhu Bitrus Mailabari

Abstract:

Nigeria is a highly multifarious nation trapped between affluence and affliction. On one hand, the state has vast territorial size, economic strength, relative internal cohesion, and good external linkages. On the other, it is bedeviled with enormous challenges. It is common knowledge that the North-East geo-political zone has suffered colossal destruction for the most part of the last ten years due to the activities of the insurgent group Boko Haram. Several factors (political, economic, religious, socio-cultural) have been credited with the heightened insecurity in the region. Without a doubt, the security crisis in the region has rekindled several discussions critical to Nigeria’s security architecture. However, the debate on finding an enduring solution to the devastation in the North East continually neglects the nexus between cross border migration and national security. Using content analysis, this paper debates two main issues that continue to affect security in the North East. One, the cumulative impact of the Economic Community of West African States (ECOWAS) protocol on the free movement of people and goods. Two, the porous nature of Nigeria’s borders. Theoretically, the paper will rely on the systems theory because of its broad focus on structure, linkage, and process. The work concludes in twofold. First, that cross border migration and poor border management processes further worsened the political and socio-economic conditions of a region that is already in a bad state. Secondly, in addition to the existing strategies, Nigeria must develop a holistic approach including new methods of handling cross border movements in solving the security issues.

Keywords: border, cross border, migration, Nigeria, northeast region, security

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1516 Biosorption of Methylene Blue and Acid Red-88 from Wastewater by Using Cypress Cones

Authors: Onur Yel

Abstract:

This study represents the removal of harmful dye substances from wastewaters by using waste and cheap adsorbents. Rapid population growth and industrialization occasion anthropogenic pollution which gives irreversible damage to the environment. One of the ways in which water pollution occurs is caused by the release of the dyestuffs in the textile industry. The release of dyestuffs to the environment directly damages the living creatures that have acquired water habitat. Especially, wastewater cannot be used for nutritional purposes. In addition, some adsorbents have mutagenic and/or carcinogenic effects. By blocking photosynthesis, it hinders the inhibition of photosynthetic bacteria in the water, which damages the ecological balance and also causes the formation of malodorous compounds. Moreover, the lack of oxygen can pose a serious danger to the lives of other living organisms that need oxygen. In recent years, some physical and chemical methods are preferred for the removal of dyestuffs. However, the utilization of these methods is expensive. For this reason, the availability of new and cheap adsorbents becomes the more significant issue. In this study, an investigation of various variables on the removal of Methylene Blue and Acid Red-88 dyestuffs from wastewaters by the usage of pulverized cypress cones has been carried out. Thus, various masses of absorbent (0.1-0.25-0.5-1-2-4-5 grams) are used in 50, 100, 150, 200, 300 ppm concentrations of Methylene Blue and Acid Red-88 dyestuffs’ solutions, and with a variety of the interaction time (0.25-0.5-1-2-4-5 hours). The mixtures were centrifuged and the absorbance of the filtrates was measured on a UV spectrophotometer to determine their remaining concentrations. In the study, the highest removal ratio of Acid Red-88 dyestuff was found to be 81% at 200 ppm of dyestuff with 2 grams of adsorbent at 300 minutes. For Methylene Blue experiments, the removal percentage was found as 98% where 2 grams of adsorbent is used in 200 ppm dyestuff solution at 120 minutes of interaction.

Keywords: acid red-88, biosorption, methylene blue, cypress cones, water pollution

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1515 Faster Pedestrian Recognition Using Deformable Part Models

Authors: Alessandro Preziosi, Antonio Prioletti, Luca Castangia

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Deformable part models achieve high precision in pedestrian recognition, but all publicly available implementations are too slow for real-time applications. We implemented a deformable part model algorithm fast enough for real-time use by exploiting information about the camera position and orientation. This implementation is both faster and more precise than alternative DPM implementations. These results are obtained by computing convolutions in the frequency domain and using lookup tables to speed up feature computation. This approach is almost an order of magnitude faster than the reference DPM implementation, with no loss in precision. Knowing the position of the camera with respect to horizon it is also possible prune many hypotheses based on their size and location. The range of acceptable sizes and positions is set by looking at the statistical distribution of bounding boxes in labelled images. With this approach it is not needed to compute the entire feature pyramid: for example higher resolution features are only needed near the horizon. This results in an increase in mean average precision of 5% and an increase in speed by a factor of two. Furthermore, to reduce misdetections involving small pedestrians near the horizon, input images are supersampled near the horizon. Supersampling the image at 1.5 times the original scale, results in an increase in precision of about 4%. The implementation was tested against the public KITTI dataset, obtaining an 8% improvement in mean average precision over the best performing DPM-based method. By allowing for a small loss in precision computational time can be easily brought down to our target of 100ms per image, reaching a solution that is faster and still more precise than all publicly available DPM implementations.

Keywords: autonomous vehicles, deformable part model, dpm, pedestrian detection, real time

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1514 Crab Shell Waste Chitosan-Based Thin Film for Acoustic Sensor Applications

Authors: Maydariana Ayuningtyas, Bambang Riyanto, Akhiruddin Maddu

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Industrial waste of crustacean shells, such as shrimp and crab, has been considered as one of the major issues contributing to environmental pollution. The waste processing mechanisms to form new, practical substances with added value have been developed. Chitosan, a derived matter from chitin, which is obtained from crab and shrimp shells, performs prodigiously in broad range applications. A chitosan composite-based diaphragm is a new inspiration in fiber optic acoustic sensor advancement. Elastic modulus, dynamic response, and sensitivity to acoustic wave of chitosan-based composite film contribute great potentials of organic-based sound-detecting material. The objective of this research was to develop chitosan diaphragm application in fiber optic microphone system. The formulation was conducted by blending 5% polyvinyl alcohol (PVA) solution with dissolved chitosan at 0%, 1% and 2% in 1:1 ratio, respectively. Composite diaphragms were characterized for the morphological and mechanical properties to predict the desired acoustic sensor sensitivity. The composite with 2% chitosan indicated optimum performance with 242.55 µm thickness, 67.9% relative humidity, and 29-76% light transmittance. The Young’s modulus of 2%-chitosan composite material was 4.89×104 N/m2, which generated the voltage amplitude of 0.013V and performed sensitivity of 3.28 mV/Pa at 1 kHz. Based on the results above, chitosan from crustacean shell waste can be considered as a viable alternative material for fiber optic acoustic sensor sensing pad development. Further, the research in chitosan utilisation is proposed as novel optical microphone development in anthropogenic noise controlling effort for environmental and biodiversity conservation.

Keywords: acoustic sensor, chitosan, composite, crab shell, diaphragm, waste utilisation

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1513 Numerical Investigation of the Influence on Buckling Behaviour Due to Different Launching Bearings

Authors: Nadine Maier, Martin Mensinger, Enea Tallushi

Abstract:

In general, today, two types of launching bearings are used in the construction of large steel and steel concrete composite bridges. These are sliding rockers and systems with hydraulic bearings. The advantages and disadvantages of the respective systems are under discussion. During incremental launching, the center of the webs of the superstructure is not perfectly in line with the center of the launching bearings due to unavoidable tolerances, which may have an influence on the buckling behavior of the web plates. These imperfections are not considered in the current design against plate buckling, according to DIN EN 1993-1-5. It is therefore investigated whether the design rules have to take into account any eccentricities which occur during incremental launching and also if this depends on the respective launching bearing. Therefore, at the Technical University Munich, large-scale buckling tests were carried out on longitudinally stiffened plates under biaxial stresses with the two different types of launching bearings and eccentric load introduction. Based on the experimental results, a numerical model was validated. Currently, we are evaluating different parameters for both types of launching bearings, such as load introduction length, load eccentricity, the distance between longitudinal stiffeners, the position of the rotation point of the spherical bearing, which are used within the hydraulic bearings, web, and flange thickness and imperfections. The imperfection depends on the geometry of the buckling field and whether local or global buckling occurs. This and also the size of the meshing is taken into account in the numerical calculations of the parametric study. As a geometric imperfection, the scaled first buckling mode is applied. A bilinear material curve is used so that a GMNIA analysis is performed to determine the load capacity. Stresses and displacements are evaluated in different directions, and specific stress ratios are determined at the critical points of the plate at the time of the converging load step. To evaluate the load introduction of the transverse load, the transverse stress concentration is plotted on a defined longitudinal section on the web. In the same way, the rotation of the flange is evaluated in order to show the influence of the different degrees of freedom of the launching bearings under eccentric load introduction and to be able to make an assessment for the case, which is relevant in practice. The input and the output are automatized and depend on the given parameters. Thus we are able to adapt our model to different geometric dimensions and load conditions. The programming is done with the help of APDL and a Python code. This allows us to evaluate and compare more parameters faster. Input and output errors are also avoided. It is, therefore, possible to evaluate a large spectrum of parameters in a short time, which allows a practical evaluation of different parameters for buckling behavior. This paper presents the results of the tests as well as the validation and parameterization of the numerical model and shows the first influences on the buckling behavior under eccentric and multi-axial load introduction.

Keywords: buckling behavior, eccentric load introduction, incremental launching, large scale buckling tests, multi axial stress states, parametric numerical modelling

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1512 High Pressure Torsion Deformation Behavior of a Low-SFE FCC Ternary Medium Entropy Alloy

Authors: Saumya R. Jha, Krishanu Biswas, Nilesh P. Gurao

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Several recent investigations have revealed medium entropy alloys exhibiting better mechanical properties than their high entropy counterparts. This clearly establishes that although a higher entropy plays a vital role in stabilization of particular phase over complex intermetallic phases, configurational entropy is not the primary factor responsible for the high inherent strengthening in these systems. Above and beyond a high contribution from friction stresses and solid solution strengthening, strain hardening is an important contributor to the strengthening in these systems. In this regard, researchers have developed severe plastic deformation (SPD) techniques like High Pressure Torsion (HPT) to incorporate very high shear strain in the material, thereby leading to ultrafine grained (UFG) microstructures, which cause manifold increase in the strength. The presented work demonstrates a meticulous study of the variation in mechanical properties at different radial displacements from the center of HPT tested equiatomic ternary FeMnNi synthesized by casting route, which is a low stacking fault energy FCC alloy that shows significantly higher toughness than its high entropy counterparts like Cantor alloy. The gradient in grain sizes along the radial direction of these specimens has been modeled using microstructure entropy for predicting the mechanical properties, which has also been validated by indentation tests. The dislocation density is computed by FEM simulations for varying strains and validated by analyzing synchrotron diffraction data. Thus, the proposed model can be utilized to predict the strengthening behavior of similar systems deformed by HPT subjected to varying loading conditions.

Keywords: high pressure torsion, severe plastic deformation, configurational entropy, dislocation density, FEM simulation

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1511 Exploring the Determinants of Boko Haram Terrorism in Nigerian Security Systems and Economy

Authors: Abara Onu, Augustine Mina Ephraim, Emmanuel Teidi

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Terrorism has been a major challenge and is so dare to the Nigerian government in recent times. The actions and activities of the Islamic sect known as Boko Haram had led to enormous loss of lives and properties in the country, mostly the Northern part of Nigeria. Some of these activities entails bombings, suicide attacks, intimidations, sporadic gunfire of the unarmed, blameless and innocent Nigerians, burning of police stations and churches, kidnappings, raping of school girls and women. Nigeria has also been included amongst one of the terrorist countries of the world. This has serious implications for the development of Nigerian economy. Although, Nigeria had made several worried hard work to deal with these challenges masqueraded by terrorism and insecurity in the country but the rate of insurgency and insecurity is still worrisome. The study looks at exploring the determinants of Boko Haram terrorism in Nigerian security systems and economy. Data used for the study work was from questionnaire administered, using Analysis of Variance (ANOVA) method to analyse the data. The result shows that Ideology and funding are significant basic factors that propelled the Boko Haram group in Nigeria. The Boko Haram disaster poses a significant threat to Nigeria’s economy and the military is the best option and solution in tackling the Boko Haram menace in Nigeria. The work x-rayed the following recommendations; government should declare war on terrorism and as well seek support and cooperation from international communities who in time or the other might have faced with this kind ugly experience and challenge and were able to tackle it. Nigerian Military needs to be more empowered with high dangerous weapons to combat the insurgency as well as beef up security across the Country to curb the threats.

Keywords: terrorism, economy, Boko Haram, Nigeria

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1510 Understanding Cyber Kill Chains: Optimal Allocation of Monitoring Resources Using Cooperative Game Theory

Authors: Roy. H. A. Lindelauf

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Cyberattacks are complex processes consisting of multiple interwoven tasks conducted by a set of agents. Interdictions and defenses against such attacks often rely on cyber kill chain (CKC) models. A CKC is a framework that tries to capture the actions taken by a cyber attacker. There exists a growing body of literature on CKCs. Most of this work either a) describes the CKC with respect to one or more specific cyberattacks or b) discusses the tools and technologies used by the attacker at each stage of the CKC. Defenders, facing scarce resources, have to decide where to allocate their resources given the CKC and partial knowledge on the tools and techniques attackers use. In this presentation CKCs are analyzed through the lens of covert projects, i.e., interrelated tasks that have to be conducted by agents (human and/or computer) with the aim of going undetected. Various aspects of covert project models have been studied abundantly in the operations research and game theory domain, think of resource-limited interdiction actions that maximally delay completion times of a weapons project for instance. This presentation has investigated both cooperative and non-cooperative game theoretic covert project models and elucidated their relation to CKC modelling. To view a CKC as a covert project each step in the CKC is broken down into tasks and there are players of which each one is capable of executing a subset of the tasks. Additionally, task inter-dependencies are represented by a schedule. Using multi-glove cooperative games it is shown how a defender can optimize the allocation of his scarce resources (what, where and how to monitor) against an attacker scheduling a CKC. This study presents and compares several cooperative game theoretic solution concepts as metrics for assigning resources to the monitoring of agents.

Keywords: cyber defense, cyber kill chain, game theory, information warfare techniques

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1509 Music Piracy Revisited: Agent-Based Modelling and Simulation of Illegal Consumption Behavior

Authors: U. S. Putro, L. Mayangsari, M. Siallagan, N. P. Tjahyani

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National Collective Management Institute (LKMN) in Indonesia stated that legal music products were about 77.552.008 unit while illegal music products were about 22.0688.225 unit in 1996 and this number keeps getting worse every year. Consequently, Indonesia named as one of the countries with high piracy levels in 2005. This study models people decision toward unlawful behavior, music content piracy in particular, using agent-based modeling and simulation (ABMS). The classification of actors in the model constructed in this study are legal consumer, illegal consumer, and neutral consumer. The decision toward piracy among the actors is a manifestation of the social norm which attributes are social pressure, peer pressure, social approval, and perceived prevalence of piracy. The influencing attributes fluctuate depending on the majority of surrounding behavior called social network. There are two main interventions undertaken in the model, campaign and peer influence, which leads to scenarios in the simulation: positively-framed descriptive norm message, negatively-framed descriptive norm message, positively-framed injunctive norm with benefits message, and negatively-framed injunctive norm with costs message. Using NetLogo, the model is simulated in 30 runs with 10.000 iteration for each run. The initial number of agent was set 100 proportion of 95:5 for illegal consumption. The assumption of proportion is based on the data stated that 95% sales of music industry are pirated. The finding of this study is that negatively-framed descriptive norm message has a worse reversed effect toward music piracy. The study discovers that selecting the context-based campaign is the key process to reduce the level of intention toward music piracy as unlawful behavior by increasing the compliance awareness. The context of Indonesia reveals that that majority of people has actively engaged in music piracy as unlawful behavior, so that people think that this illegal act is common behavior. Therefore, providing the information about how widespread and big this problem is could make people do the illegal consumption behavior instead. The positively-framed descriptive norm message scenario works best to reduce music piracy numbers as it focuses on supporting positive behavior and subject to the right perception on this phenomenon. Music piracy is not merely economical, but rather social phenomenon due to the underlying motivation of the actors which has shifted toward community sharing. The indication of misconception of value co-creation in the context of music piracy in Indonesia is also discussed. This study contributes theoretically that understanding how social norm configures the behavior of decision-making process is essential to breakdown the phenomenon of unlawful behavior in music industry. In practice, this study proposes that reward-based and context-based strategy is the most relevant strategy for stakeholders in music industry. Furthermore, this study provides an opportunity that findings may generalize well beyond music piracy context. As an emerging body of work that systematically constructs the backstage of law and social affect decision-making process, it is interesting to see how the model is implemented in other decision-behavior related situation.

Keywords: music piracy, social norm, behavioral decision-making, agent-based model, value co-creation

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1508 E-Learning Recommender System Based on Collaborative Filtering and Ontology

Authors: John Tarus, Zhendong Niu, Bakhti Khadidja

Abstract:

In recent years, e-learning recommender systems has attracted great attention as a solution towards addressing the problem of information overload in e-learning environments and providing relevant recommendations to online learners. E-learning recommenders continue to play an increasing educational role in aiding learners to find appropriate learning materials to support the achievement of their learning goals. Although general recommender systems have recorded significant success in solving the problem of information overload in e-commerce domains and providing accurate recommendations, e-learning recommender systems on the other hand still face some issues arising from differences in learner characteristics such as learning style, skill level and study level. Conventional recommendation techniques such as collaborative filtering and content-based deal with only two types of entities namely users and items with their ratings. These conventional recommender systems do not take into account the learner characteristics in their recommendation process. Therefore, conventional recommendation techniques cannot make accurate and personalized recommendations in e-learning environment. In this paper, we propose a recommendation technique combining collaborative filtering and ontology to recommend personalized learning materials to online learners. Ontology is used to incorporate the learner characteristics into the recommendation process alongside the ratings while collaborate filtering predicts ratings and generate recommendations. Furthermore, ontological knowledge is used by the recommender system at the initial stages in the absence of ratings to alleviate the cold-start problem. Evaluation results show that our proposed recommendation technique outperforms collaborative filtering on its own in terms of personalization and recommendation accuracy.

Keywords: collaborative filtering, e-learning, ontology, recommender system

Procedia PDF Downloads 361
1507 Service Life Study of Polymers Used in Renovation of Heritage Buildings and Other Structures

Authors: Parastou Kharazmi

Abstract:

Degradation of building materials particularly pipelines causes environmental damage during renovation or replacement and is a time consuming and costly process. Rehabilitation by polymer composites is a solution for renovation of degraded pipeline in heritage buildings and other structures which are less costly, faster and causes less damage to the environment; however, it is still not clear for how long these materials can perform as expected in the field and working condition. To study their service life, two types of composites based on Epoxy and Polyester resins have been evaluated by accelerated exposure and field exposure. The primary degradation agent used in accelerated exposure has been cycling temperature with half of the tests performed in presence of water. Thin films of materials used in accelerated testing were prepared in laboratory by using the same amount of material as well as technique of multi-layers application used in majority of the field installations. Extreme intensity levels of degradation agents have been used only to evaluate materials properties and as also mentioned in ISO 15686, are not directly correlated with degradation mechanisms that would be experienced in service. In the field exposure study, the focus has been to identify possible failure modes, causes, and effects. In field exposure, it has been observed that there are other degradation agents present which can be investigated further such as presence of contaminants and rust before application which prevents formation of a uniform layer of polymer or incompatibility between dissimilar materials. This part of the study also highlighted the importance of application’s quality of the materials in the field for providing the expected performance and service life. Results from extended accelerated exposure and field exposure can help in choosing inspection techniques, establishing the primary degradation agents and can be used for ageing exposure programs with clarifying relationship between different exposure periods and sites.

Keywords: building, renovation, service life, pipelines

Procedia PDF Downloads 182
1506 Iot-Based Interactive Patient Identification and Safety Management System

Authors: Jonghoon Chun, Insung Kim, Jonghyun Lim, Gun Ro

Abstract:

We believe that it is possible to provide a solution to reduce patient safety accidents by displaying correct medical records and prescription information through interactive patient identification. Our system is based on the use of smart bands worn by patients and these bands communicate with the hybrid gateways which understand both BLE and Wifi communication protocols. Through the convergence of low-power Bluetooth (BLE) and hybrid gateway technology, which is one of short-range wireless communication technologies, we implement ‘Intelligent Patient Identification and Location Tracking System’ to prevent medical malfunction frequently occurring in medical institutions. Based on big data and IOT technology using MongoDB, smart band (BLE, NFC function) and hybrid gateway, we develop a system to enable two-way communication between medical staff and hospitalized patients as well as to store locational information of the patients in minutes. Based on the precise information provided using big data systems, such as location tracking and movement of in-hospital patients wearing smart bands, our findings include the fact that a patient-specific location tracking algorithm can more efficiently operate HIS (Hospital Information System) and other related systems. Through the system, we can always correctly identify patients using identification tags. In addition, the system automatically determines whether the patient is a scheduled for medical service by the system in use at the medical institution, and displays the appropriateness of the medical treatment and the medical information (medical record and prescription information) on the screen and voice. This work was supported in part by the Korea Technology and Information Promotion Agency for SMEs (TIPA) grant funded by the Korean Small and Medium Business Administration (No. S2410390).

Keywords: BLE, hybrid gateway, patient identification, IoT, safety management, smart band

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1505 Monitoring the Production of Large Composite Structures Using Dielectric Tool Embedded Capacitors

Authors: Galatee Levadoux, Trevor Benson, Chris Worrall

Abstract:

With the rise of public awareness on climate change comes an increasing demand for renewable sources of energy. As a result, the wind power sector is striving to manufacture longer, more efficient and reliable wind turbine blades. Currently, one of the leading causes of blade failure in service is improper cure of the resin during manufacture. The infusion process creating the main part of the composite blade structure remains a critical step that is yet to be monitored in real time. This stage consists of a viscous resin being drawn into a mould under vacuum, then undergoing a curing reaction until solidification. Successful infusion assumes the resin fills all the voids and cures completely. Given that the electrical properties of the resin change significantly during its solidification, both the filling of the mould and the curing reaction are susceptible to be followed using dieletrometry. However, industrially available dielectrics sensors are currently too small to monitor the entire surface of a wind turbine blade. The aim of the present research project is to scale up the dielectric sensor technology and develop a device able to monitor the manufacturing process of large composite structures, assessing the conformity of the blade before it even comes out of the mould. An array of flat copper wires acting as electrodes are embedded in a polymer matrix fixed in an infusion mould. A multi-frequency analysis from 1 Hz to 10 kHz is performed during the filling of the mould with an epoxy resin and the hardening of the said resin. By following the variations of the complex admittance Y*, the filling of the mould and curing process are monitored. Results are compared to numerical simulations of the sensor in order to validate a virtual cure-monitoring system. The results obtained by drawing glycerol on top of the copper sensor displayed a linear relation between the wetted length of the sensor and the complex admittance measured. Drawing epoxy resin on top of the sensor and letting it cure at room temperature for 24 hours has provided characteristic curves obtained when conventional interdigitated sensor are used to follow the same reaction. The response from the developed sensor has shown the different stages of the polymerization of the resin, validating the geometry of the prototype. The model created and analysed using COMSOL has shown that the dielectric cure process can be simulated, so long as a sufficient time and temperature dependent material properties can be determined. The model can be used to help design larger sensors suitable for use with full-sized blades. The preliminary results obtained with the sensor prototype indicate that the infusion and curing process of an epoxy resin can be followed with the chosen configuration on a scale of several decimeters. Further work is to be devoted to studying the influence of the sensor geometry and the infusion parameters on the results obtained. Ultimately, the aim is to develop a larger scale sensor able to monitor the flow and cure of large composite panels industrially.

Keywords: composite manufacture, dieletrometry, epoxy, resin infusion, wind turbine blades

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1504 Meta Model for Optimum Design Objective Function of Steel Frames Subjected to Seismic Loads

Authors: Salah R. Al Zaidee, Ali S. Mahdi

Abstract:

Except for simple problems of statically determinate structures, optimum design problems in structural engineering have implicit objective functions where structural analysis and design are essential within each searching loop. With these implicit functions, the structural engineer is usually enforced to write his/her own computer code for analysis, design, and searching for optimum design among many feasible candidates and cannot take advantage of available software for structural analysis, design, and searching for the optimum solution. The meta-model is a regression model used to transform an implicit objective function into objective one and leads in turn to decouple the structural analysis and design processes from the optimum searching process. With the meta-model, well-known software for structural analysis and design can be used in sequence with optimum searching software. In this paper, the meta-model has been used to develop an explicit objective function for plane steel frames subjected to dead, live, and seismic forces. Frame topology is assumed as predefined based on architectural and functional requirements. Columns and beams sections and different connections details are the main design variables in this study. Columns and beams are grouped to reduce the number of design variables and to make the problem similar to that adopted in engineering practice. Data for the implicit objective function have been generated based on analysis and assessment for many design proposals with CSI SAP software. These data have been used later in SPSS software to develop a pure quadratic nonlinear regression model for the explicit objective function. Good correlations with a coefficient, R2, in the range from 0.88 to 0.99 have been noted between the original implicit functions and the corresponding explicit functions generated with meta-model.

Keywords: meta-modal, objective function, steel frames, seismic analysis, design

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1503 Real-Time Radar Tracking Based on Nonlinear Kalman Filter

Authors: Milca F. Coelho, K. Bousson, Kawser Ahmed

Abstract:

To accurately track an aerospace vehicle in a time-critical situation and in a highly nonlinear environment, is one of the strongest interests within the aerospace community. The tracking is achieved by estimating accurately the state of a moving target, which is composed of a set of variables that can provide a complete status of the system at a given time. One of the main ingredients for a good estimation performance is the use of efficient estimation algorithms. A well-known framework is the Kalman filtering methods, designed for prediction and estimation problems. The success of the Kalman Filter (KF) in engineering applications is mostly due to the Extended Kalman Filter (EKF), which is based on local linearization. Besides its popularity, the EKF presents several limitations. To address these limitations and as a possible solution to tracking problems, this paper proposes the use of the Ensemble Kalman Filter (EnKF). Although the EnKF is being extensively used in the context of weather forecasting and it is being recognized for producing accurate and computationally effective estimation on systems with a very high dimension, it is almost unknown by the tracking community. The EnKF was initially proposed as an attempt to improve the error covariance calculation, which on the classic Kalman Filter is difficult to implement. Also, in the EnKF method the prediction and analysis error covariances have ensemble representations. These ensembles have sizes which limit the number of degrees of freedom, in a way that the filter error covariance calculations are a lot more practical for modest ensemble sizes. In this paper, a realistic simulation of a radar tracking was performed, where the EnKF was applied and compared with the Extended Kalman Filter. The results suggested that the EnKF is a promising tool for tracking applications, offering more advantages in terms of performance.

Keywords: Kalman filter, nonlinear state estimation, optimal tracking, stochastic environment

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1502 Theory of the Optimum Signal Approximation Clarifying the Importance in the Recognition of Parallel World and Application to Secure Signal Communication with Feedback

Authors: Takuro Kida, Yuichi Kida

Abstract:

In this paper, it is shown a base of the new trend of algorithm mathematically that treats a historical reason of continuous discrimination in the world as well as its solution by introducing new concepts of parallel world that includes an invisible set of errors as its companion. With respect to a matrix operator-filter bank that the matrix operator-analysis-filter bank H and the matrix operator-sampling-filter bank S are given, firstly, we introduce the detail algorithm to derive the optimum matrix operator-synthesis-filter bank Z that minimizes all the worst-case measures of the matrix operator-error-signals E(ω) = F(ω) − Y(ω) between the matrix operator-input-signals F(ω) and the matrix operator-output-signals Y(ω) of the matrix operator-filter bank at the same time. Further, feedback is introduced to the above approximation theory, and it is indicated that introducing conversations with feedback do not superior automatically to the accumulation of existing knowledge of signal prediction. Secondly, the concept of category in the field of mathematics is applied to the above optimum signal approximation and is indicated that the category-based approximation theory is applied to the set-theoretic consideration of the recognition of humans. Based on this discussion, it is shown naturally why the narrow perception that tends to create isolation shows an apparent advantage in the short term and, often, why such narrow thinking becomes intimate with discriminatory action in a human group. Throughout these considerations, it is presented that, in order to abolish easy and intimate discriminatory behavior, it is important to create a parallel world of conception where we share the set of invisible error signals, including the words and the consciousness of both worlds.

Keywords: matrix filterbank, optimum signal approximation, category theory, simultaneous minimization

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1501 The Prospect of Income Contingent Loan in Malaysia Higher Education Financing Using Deterministic and Stochastic Methods in Modelling Income

Authors: Syaza Isma, Timothy Higgins

Abstract:

In Malaysia, increased take-up rates of tertiary student borrowing, and reliance on retirement savings to fund children's education show the importance of public higher education financing schemes (PTPTN). PTPTN has been operating for 2 decades now; however, there are some critical issues and challenges that include low loan recovery and loan default that suggest a detailed consideration of student loan/financing scheme alternatives is crucial. In addition, the decline in funding level per student following introduction of the new PTPTN full and partial loan scheme has raised ongoing concerns over the sustainability of the scheme to provide continuous financial assistance to students in tertiary education. This research seeks to assess these issues that put greater efficiency in an effort to ensure equitable access to student funding for current and future generations. We explore the extent of repayment hardship under the current loan arrangements that presumably led to low recovery from the borrowers, particularly low-income graduates. The concept of manageable debt exists in the design of income-contingent repayment schemes, as practiced in Australia, New Zealand, UK, Hungary, USA (in limited form), the Netherlands, and South Korea. Can Income Contingent Loans (ICL) offer the best practice for an education financing scheme, and address the issue of repayment hardship and concurrently, can a properly designed ICL scheme provide a solution to the current issues and challenges facing Malaysia student financing? We examine the different potential ICL models using deterministic and stochastic approach to simulate income of graduates.

Keywords: deterministic, income contingent loan, repayment burden, simulation, stochastic

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1500 Wadjda, a Film That Quietly Sets the Stage for a Cultural Revolution in Saudi Arabia

Authors: Anouar El Younssi

Abstract:

This study seeks to shed some light on the political and social ramifications and implications of Haifaa al-Mansour’s 2012 film Wadjda. The film made international headlines following its release, and was touted as the first film ever to be shot in its entirety inside the Kingdom of Saudi Arabia, and also the first to be directed by a female (Haifaa al-Mansour). Wadjda revolves around a simple storyline: A teenage Saudi girl living in the capital city Riyadh—named Wadjda—wants to have a bicycle just like her male teenage neighbor and friend Abdullah, but her ultra-conservative Saudi society places so many constraints on its female population—including not allowing girls and women to ride bicycles. Wadjda, who displays a rebellious spirit, takes concrete steps to save money in order to realize her dream of buying a bicycle. For example, she starts making and selling sports bracelets to her school mates, and she decides to participate in a Qur’an competition in hopes of winning a sum of money that comes with the first prize. In the end, Wadjda could not beat the system on her own, but the film reverses course, and the audience gets a happy ending: Wadjda’s mother, whose husband has decided to take a second wife, defies the system and buys her daughter the very bicycle Wadjda has been dreaming of. It is quite significant that the mother takes her daughter’s side on the subject of the bicycle at the end of the film, for this shows that she finally came to the realization that she and her daughter are both oppressed by the cultural norms prevalent in Saudi society. It is no coincidence that this change of heart and action on the part of the mother takes place immediately after the wedding night celebrating her husband’s second marriage. Gender inequality is thus placed front and center in the film. Nevertheless, a major finding of this study is that the film carries out its social critique in a soft and almost covert manner. The female actors in the film never issue a direct criticism of Saudi society or government; the criticism is consistently implied and subtle throughout. It is a criticism that relies more on showing than telling. The film shows us—rather than tells us directly—what is wrong, and lets us, the audience, decide and make a judgment. In fact, showing could arguably be more powerful and impactful than telling. Regarding methodology, this study will focus on and analyze the visuals and a number of key utterances by the main actor Wadjda in order to corroborate the study’s argument about the film’s bent on critiquing patriarchy. This research will attempt to establish a link between the film as an art object and as a social text. Ultimately, Wadjda sends a message of hope, that change is possible and that it is already happening slowly inside the Kingdom. It also sends the message that an insurrectional approach regarding women’s rights in Saudi Arabia is perhaps not the right one, at least at this historical juncture.

Keywords: bicycle, gender inequality, social critique, Wadjda, women’s rights

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1499 A System for Preventing Inadvertent Exposition of Staff Present outside the Operating Theater: Description and Clinical Test

Authors: Aya Al Masri, Kamel Guerchouche, Youssef Laynaoui, Safoin Aktaou, Malorie Martin, Fouad Maaloul

Abstract:

Introduction: Mobile C-arms move throughout operating rooms of the operating theater. Being designed to move between rooms, they are not equipped with relays to retrieve the exposition information and export it outside the room. Therefore, no light signaling is available outside the room to warn the X-ray emission for staff. Inadvertent exposition of staff outside the operating theater is a real problem for radiation protection. The French standard NFC 15-160 require that: (1) access to any room containing an X-ray emitting device must be controlled by a light signage so that it cannot be inadvertently crossed, and (2) setting up an emergency button to stop the X-ray emission. This study presents a system that we developed to meet these requirements and the results of its clinical test. Materials and methods: The system is composed of two communicating boxes: o The "DetectBox" is to be installed inside the operating theater. It identifies the various operation states of the C-arm by analyzing its power supply signal. The DetectBox communicates (in wireless mode) with the second box (AlertBox). o The "AlertBox" can operate in socket or battery mode and is to be installed outside the operating theater. It detects and reports the state of the C-arm by emitting a real time light signal. This latter can have three different colors: red when the C-arm is emitting X-rays, orange when it is powered on but does not emit X-rays, and green when it is powered off. The two boxes communicate on a radiofrequency link exclusively carried out in the ‘Industrial, Scientific and Medical (ISM)’ frequency bands and allows the coexistence of several on-site warning systems without communication conflicts (interference). Taking into account the complexity of performing electrical works in the operating theater (for reasons of hygiene and continuity of medical care), this system (having a size <10 cm²) works in complete safety without any intrusion in the mobile C-arm and does not require specific electrical installation work. The system is equipped with emergency button that stops X-ray emission. The system has been clinically tested. Results: The clinical test of the system shows that: it detects X-rays having both high and low energy (50 – 150 kVp), high and low photon flow (0.5 – 200 mA: even when emitted for a very short time (<1 ms)), Probability of false detection < 10-5, it operates under all acquisition modes (continuous, pulsed, fluoroscopy mode, image mode, subtraction and movie mode), it is compatible with all C-arm models and brands. We have also tested the communication between the two boxes (DetectBox and AlertBox) in several conditions: (1) Unleaded room, (2) leaded room, and (3) rooms with particular configuration (sas, great distances, concrete walls, 3 mm of lead). The result of these last tests was positive. Conclusion: This system is a reliable tool to alert the staff present outside the operating room for X-ray emission and insure their radiation protection.

Keywords: Clinical test, Inadvertent staff exposition, Light signage, Operating theater

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1498 Confidence Envelopes for Parametric Model Selection Inference and Post-Model Selection Inference

Authors: I. M. L. Nadeesha Jayaweera, Adao Alex Trindade

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In choosing a candidate model in likelihood-based modeling via an information criterion, the practitioner is often faced with the difficult task of deciding just how far up the ranked list to look. Motivated by this pragmatic necessity, we construct an uncertainty band for a generalized (model selection) information criterion (GIC), defined as a criterion for which the limit in probability is identical to that of the normalized log-likelihood. This includes common special cases such as AIC & BIC. The method starts from the asymptotic normality of the GIC for the joint distribution of the candidate models in an independent and identically distributed (IID) data framework and proceeds by deriving the (asymptotically) exact distribution of the minimum. The calculation of an upper quantile for its distribution then involves the computation of multivariate Gaussian integrals, which is amenable to efficient implementation via the R package "mvtnorm". The performance of the methodology is tested on simulated data by checking the coverage probability of nominal upper quantiles and compared to the bootstrap. Both methods give coverages close to nominal for large samples, but the bootstrap is two orders of magnitude slower. The methodology is subsequently extended to two other commonly used model structures: regression and time series. In the regression case, we derive the corresponding asymptotically exact distribution of the minimum GIC invoking Lindeberg-Feller type conditions for triangular arrays and are thus able to similarly calculate upper quantiles for its distribution via multivariate Gaussian integration. The bootstrap once again provides a default competing procedure, and we find that similar comparison performance metrics hold as for the IID case. The time series case is complicated by far more intricate asymptotic regime for the joint distribution of the model GIC statistics. Under a Gaussian likelihood, the default in most packages, one needs to derive the limiting distribution of a normalized quadratic form for a realization from a stationary series. Under conditions on the process satisfied by ARMA models, a multivariate normal limit is once again achieved. The bootstrap can, however, be employed for its computation, whence we are once again in the multivariate Gaussian integration paradigm for upper quantile evaluation. Comparisons of this bootstrap-aided semi-exact method with the full-blown bootstrap once again reveal a similar performance but faster computation speeds. One of the most difficult problems in contemporary statistical methodological research is to be able to account for the extra variability introduced by model selection uncertainty, the so-called post-model selection inference (PMSI). We explore ways in which the GIC uncertainty band can be inverted to make inferences on the parameters. This is being attempted in the IID case by pivoting the CDF of the asymptotically exact distribution of the minimum GIC. For inference one parameter at a time and a small number of candidate models, this works well, whence the attained PMSI confidence intervals are wider than the MLE-based Wald, as expected.

Keywords: model selection inference, generalized information criteria, post model selection, Asymptotic Theory

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1497 How to “Eat” without Actually Eating: Marking Metaphor with Spanish Se and Italian Si

Authors: Cinzia Russi, Chiyo Nishida

Abstract:

Using data from online corpora (Spanish CREA, Italian CORIS), this paper examines the relatively understudied use of Spanish se and Italian si exemplified in (1) and (2), respectively. (1) El rojo es … el que se come a los demás. ‘The red (bottle) is the one that outshines/*eats the rest.’(2) … ebbe anche la saggezza di mangiarsi tutto il suo patrimonio. ‘… he even had the wisdom to squander/*eat all his estate.’ In these sentences, se/si accompanies the consumption verb comer/mangiare ‘to eat’, without which the sentences would not be interpreted appropriately. This se/si cannot readily be attributed to any of the multiple functions so far identified in the literature: reflexive, ergative, middle/passive, inherent, benefactive, and complete consumptive. In particular, this paper argues against the feasibility of a recent construction-based analysis of sentences like (1) and (2), which situates se/si within a prototype-based network of meanings all deriving from the central meaning of 'COMPLETE CONSUMPTION' (e.g., Alice se comió toda la torta/Alicesi è mangiata tutta la torta ‘John ate the whole cake’). Clearly, the empirical adequacy of such an account is undermined by the fact that the events depicted in the se/si-sentences at issue do not always entail complete consumption because they may lack an INCREMENTAL THEME, the distinguishing property of complete consumption. Alternatively, it is proposed that the sentences under analysis represent instances of verbal METAPHORICAL EXTENSION: se/si represents an explicit marker of this cognitive process, which has independently developed from the complete consumptive se/si, and the meaning extension is captured by the general tenets of Conceptual Metaphor Theory (CMT). Two conceptual domains, Source (DS) and target (DT), are related by similarity, assigning an appropriate metaphorical interpretation to DT. The domains paired here are comer/mangiare (DS) and comerse/mangiarsi (DT). The eating event (DS) involves (a) the physical process of xEATER grinding yFOOD-STUFF into pieces and swallowing it; and (b) the aspect of xEATER savoring yFOOD-STUFF and being nurtured by it. In the physical act of eating, xEATER has dominance and exercises his force over yFOOD-STUFF. This general sense of dominance and force is mapped onto DT and is manifested in the ways exemplified in (1) and (2), and many others. According to CMT, two other properties are observed in each pair of DS & DT. First, DS tends to be more physical and concrete and DT more abstract, and systematic mappings are established between constituent elements in DS and those in DT: xEATER corresponds to the element that destroys and yFOOD-STUFF to the element that is destroyed in DT, as exemplified in (1) and (2). Though the metaphorical extension marker se/si appears by far most frequently with comer/mangiare in the corpora, similar systematic mappings are observed in several other verb pairs, for example, jugar/giocare ‘to play (games)’ and jugarse/giocarsi ‘to jeopardize/risk (life, reputation, etc.)’, perder/perdere ‘to lose (an object)’ and perderse/perdersi ‘to miss out on (an event)’, etc. Thus, this study provides evidence that languages may indeed formally mark metaphor using means available to them.

Keywords: complete consumption value, conceptual metaphor, Italian si/Spanish se, metaphorical extension.

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1496 Dynamics and Advection in a Vortex Parquet on the Plane

Authors: Filimonova Alexanra

Abstract:

Inviscid incompressible fluid flows are considered. The object of the study is a vortex parquet – a structure consisting of distributed vortex spots of different directions, occupying the entire plane. The main attention is paid to the study of advection processes of passive particles in the corresponding velocity field. The dynamics of the vortex structures is considered in a rectangular region under the assumption that periodic boundary conditions are imposed on the stream function. Numerical algorithms are based on the solution of the initial-boundary value problem for nonstationary Euler equations in terms of vorticity and stream function. For this, the spectral-vortex meshless method is used. It is based on the approximation of the stream function by the Fourier series cut and the approximation of the vorticity field by the least-squares method from its values in marker particles. A vortex configuration, consisting of four vortex patches is investigated. Results of a numerical study of the dynamics and interaction of the structure are presented. The influence of the patch radius and the relative position of positively and negatively directed patches on the processes of interaction and mixing is studied. The obtained results correspond to the following possible scenarios: the initial configuration does not change over time; the initial configuration forms a new structure, which is maintained for longer times; the initial configuration returns to its initial state after a certain period of time. The processes of mass transfer of vorticity by liquid particles on a plane were calculated and analyzed. The results of a numerical analysis of the particles dynamics and trajectories on the entire plane and the field of local Lyapunov exponents are presented.

Keywords: ideal fluid, meshless methods, vortex structures in liquids, vortex parquet.

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