Search results for: resilience optimization model
16436 Simulation of Dynamic Behavior of Seismic Isolators Using a Parallel Elasto-Plastic Model
Authors: Nicolò Vaiana, Giorgio Serino
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In this paper, a one-dimensional (1d) Parallel Elasto- Plastic Model (PEPM), able to simulate the uniaxial dynamic behavior of seismic isolators having a continuously decreasing tangent stiffness with increasing displacement, is presented. The parallel modeling concept is applied to discretize the continuously decreasing tangent stiffness function, thus allowing to simulate the dynamic behavior of seismic isolation bearings by putting linear elastic and nonlinear elastic-perfectly plastic elements in parallel. The mathematical model has been validated by comparing the experimental force-displacement hysteresis loops, obtained testing a helical wire rope isolator and a recycled rubber-fiber reinforced bearing, with those predicted numerically. Good agreement between the simulated and experimental results shows that the proposed model can be an effective numerical tool to predict the forcedisplacement relationship of seismic isolators within relatively large displacements. Compared to the widely used Bouc-Wen model, the proposed one allows to avoid the numerical solution of a first order ordinary nonlinear differential equation for each time step of a nonlinear time history analysis, thus reducing the computation effort, and requires the evaluation of only three model parameters from experimental tests, namely the initial tangent stiffness, the asymptotic tangent stiffness, and a parameter defining the transition from the initial to the asymptotic tangent stiffness.Keywords: base isolation, earthquake engineering, parallel elasto-plastic model, seismic isolators, softening hysteresis loops
Procedia PDF Downloads 28416435 Process Modeling in an Aeronautics Context
Authors: Sophie Lemoussu, Jean-Charles Chaudemar, Robertus A. Vingerhoeds
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Many innovative projects exist in the field of aeronautics, each addressing specific areas so to reduce weight, increase autonomy, reduction of CO2, etc. In many cases, such innovative developments are being carried out by very small enterprises (VSE’s) or small and medium sized-enterprises (SME’s). A good example concerns airships that are being studied as a real alternative to passenger and cargo transportation. Today, no international regulations propose a precise and sufficiently detailed framework for the development and certification of airships. The absence of such a regulatory framework requires a very close contact with regulatory instances. However, VSE’s/SME’s do not always have sufficient resources and internal knowledge to handle this complexity and to discuss these issues. This poses an additional challenge for those VSE’s/SME’s, in particular those that have system integration responsibilities and that must provide all the necessary evidence to demonstrate their ability to design, produce, and operate airships with the expected level of safety and reliability. The main objective of this research is to provide a methodological framework enabling VSE’s/SME’s with limited resources to organize the development of airships while taking into account the constraints of safety, cost, time and performance. This paper proposes to provide a contribution to this problematic by proposing a Model-Based Systems Engineering approach. Through a comprehensive process modeling approach applied to the development processes, the regulatory constraints, existing best practices, etc., a good image can be obtained as to the process landscape that may influence the development of airships. To this effect, not only the necessary regulatory information is taken on board, also other international standards and norms on systems engineering and project management are being modeled and taken into account. In a next step, the model can be used for analysis of the specific situation for given developments, derive critical paths for the development, identify eventual conflicting aspects between the norms, standards, and regulatory expectations, or also identify those areas where not enough information is available. Once critical paths are known, optimization approaches can be used and decision support techniques can be applied so to better support VSE’s/SME’s in their innovative developments. This paper reports on the adopted modeling approach, the retained modeling languages, and how they all fit together.Keywords: aeronautics, certification, process modeling, project management, regulation, SME, systems engineering, VSE
Procedia PDF Downloads 16316434 A Posteriori Trading-Inspired Model-Free Time Series Segmentation
Authors: Plessen Mogens Graf
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Within the context of multivariate time series segmentation, this paper proposes a method inspired by a posteriori optimal trading. After a normalization step, time series are treated channelwise as surrogate stock prices that can be traded optimally a posteriori in a virtual portfolio holding either stock or cash. Linear transaction costs are interpreted as hyperparameters for noise filtering. Trading signals, as well as trading signals obtained on the reversed time series, are used for unsupervised channelwise labeling before a consensus over all channels is reached that determines the final segmentation time instants. The method is model-free such that no model prescriptions for segments are made. Benefits of proposed approach include simplicity, computational efficiency, and adaptability to a wide range of different shapes of time series. Performance is demonstrated on synthetic and real-world data, including a large-scale dataset comprising a multivariate time series of dimension 1000 and length 2709. Proposed method is compared to a popular model-based bottom-up approach fitting piecewise affine models and to a recent model-based top-down approach fitting Gaussian models and found to be consistently faster while producing more intuitive results in the sense of segmenting time series at peaks and valleys.Keywords: time series segmentation, model-free, trading-inspired, multivariate data
Procedia PDF Downloads 13816433 Stress and Distress among Physician Trainees: A Wellbeing Workshop
Authors: Carmen Axisa, Louise Nash, Patrick Kelly, Simon Willcock
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Introduction: Doctors experience high levels of burnout, stress and psychiatric morbidity. This can affect the health of the doctor and impact patient care. Study Aims: To evaluate the effectiveness of a workshop intervention to promote wellbeing for Australian Physician Trainees. Methods: A workshop was developed in consultation with specialist clinicians to promote health and wellbeing for physician trainees. The workshop objectives were to improve participant understanding about factors affecting their health and wellbeing, to outline strategies on how to improve health and wellbeing and to encourage participants to apply these strategies in their own lives. There was a focus on building resilience and developing long term healthy behaviours as part of the physician trainee daily lifestyle. Trainees had the opportunity to learn practical strategies for stress management, gain insight into their behaviour and take steps to improve their health and wellbeing. The workshop also identified resources and support systems available to trainees. The workshop duration was four and a half hours including a thirty- minute meal break where a catered meal was provided for the trainees. Workshop evaluations were conducted at the end of the workshop. Sixty-seven physician trainees from Adult Medicine and Paediatric training programs in Sydney Australia were randomised into intervention and control groups. The intervention group attended a workshop facilitated by specialist clinicians and the control group did not. Baseline and post intervention measurements were taken for both groups to evaluate the impact and effectiveness of the workshop. Forty-six participants completed all three measurements (69%). Demographic, personal and self-reported data regarding work/life patterns was collected. Outcome measures include Depression Anxiety Stress Scale (DASS), Professional Quality of Life Scale (ProQOL) and Alcohol Use Disorders Identification Test (AUDIT). Results: The workshop was well received by the physician trainees and workshop evaluations showed that the majority of trainees strongly agree or agree that the training was relevant to their needs (96%) and met their expectations (92%). All trainees strongly agree or agree that they would recommend the workshop to their medical colleagues. In comparison to the control group we observed a reduction in alcohol use, depression and burnout but an increase in stress, anxiety and secondary traumatic stress in the intervention group, at the primary endpoint measured at 6 months. However, none of these differences reached statistical significance (p > 0.05). Discussion: Although the study did not reach statistical significance, the workshop may be beneficial to physician trainees. Trainees had the opportunity to share ideas, gain insight into their own behaviour, learn practical strategies for stress management and discuss approach to work, life and self-care. The workshop discussions enabled trainees to share their experiences in a supported environment where they learned that other trainees experienced stress and burnout and they were not alone in needing to acquire successful coping mechanisms and stress management strategies. Conclusion: These findings suggest that physician trainees are a vulnerable group who may benefit from initiatives that promote wellbeing and from a more supportive work environment.Keywords: doctors' health, physician burnout, physician resilience, wellbeing workshop
Procedia PDF Downloads 19316432 The Sub-Optimality of the Electricity Subsidy on Tube Wells in Balochistan (Pakistan): An Analysis Based on Socio-Cultural and Policy Distortions
Authors: Rameesha Javaid
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Agriculture is the backbone of the economy of the province of Balochistan which is known as the ‘fruit basket’ of Pakistan. Its climate zones comprising highlands and plateaus, dependent on rain water, are more suited for the production of deciduous fruit. The vagaries of weather and more so the persistent droughts prompted the government to announce flat rates of electricity bills per month irrespective of the size of the farm, quantum or water used and the category of crop group. That has, no doubt, resulted in increased cropping intensity, more production and employment but has enormously burdened the official exchequer which picks up the residual bills in certain percentages amongst the federal and provincial governments and the local electricity company. This study tests the desirability of continuing the subsidy in the present mode. Optimization of social welfare of farmers has been the focus of the study with emphasis on the contribution of positive externalities and distortions caused in terms of negative externalities. By using the optimization technique with due allowance for distortions, it has been established that the subsidy calls for limiting policy distortions as they cause sub-optimal utilization of the tube well subsidy and improved policy programming. The sensitivity analysis with changed rankings of contributing variables towards social welfare does not significantly change the result. Therefore it leads to the net findings and policy recommendations of significantly reducing the subsidy size, correcting and curtailing policy distortions and targeting the subsidy grant more towards small farmers to generate more welfare by saving a sizeable amount from the subsidy for investment in the wellbeing of the farmers in rural Balochistan.Keywords: distortion, policy distortion, socio-cultural distortion, social welfare, subsidy
Procedia PDF Downloads 29316431 Design and Optimisation of 2-Oxoglutarate Dioxygenase Expression in Escherichia coli Strains for Production of Bioethylene from Crude Glycerol
Authors: Idan Chiyanzu, Maruping Mangena
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Crude glycerol, a major by-product from the transesterification of triacylglycerides with alcohol to biodiesel, is known to have a broad range of applications. For example, its bioconversion can afford a wide range of chemicals including alcohols, organic acids, hydrogen, solvents and intermediate compounds. In bacteria, the 2-oxoglutarate dioxygenase (2-OGD) enzymes are widely found among the Pseudomonas syringae species and have been recognized with an emerging importance in ethylene formation. However, the use of optimized enzyme function in recombinant systems for crude glycerol conversion to ethylene is still not been reported. The present study investigated the production of ethylene from crude glycerol using engineered E. coli MG1655 and JM109 strains. Ethylene production with an optimized expression system for 2-OGD in E. coli using a codon optimized construct of the ethylene-forming gene was studied. The codon-optimization resulted in a 20-fold increase of protein production and thus an enhanced production of the ethylene gas. For a reliable bioreactor performance, the effect of temperature, fermentation time, pH, substrate concentration, the concentration of methanol, concentration of potassium hydroxide and media supplements on ethylene yield was investigated. The results demonstrate that the recombinant enzyme can be used for future studies to exploit the conversion of low-priced crude glycerol into advanced value products like light olefins, and tools including recombineering techniques for DNA, molecular biology, and bioengineering can be used to allowing unlimited the production of ethylene directly from the fermentation of crude glycerol. It can be concluded that recombinant E.coli production systems represent significantly secure, renewable and environmentally safe alternative to thermochemical approach to ethylene production.Keywords: crude glycerol, bioethylene, recombinant E. coli, optimization
Procedia PDF Downloads 28016430 Optimizing Super Resolution Generative Adversarial Networks for Resource-Efficient Single-Image Super-Resolution via Knowledge Distillation and Weight Pruning
Authors: Hussain Sajid, Jung-Hun Shin, Kum-Won Cho
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Image super-resolution is the most common computer vision problem with many important applications. Generative adversarial networks (GANs) have promoted remarkable advances in single-image super-resolution (SR) by recovering photo-realistic images. However, high memory requirements of GAN-based SR (mainly generators) lead to performance degradation and increased energy consumption, making it difficult to implement it onto resource-constricted devices. To relieve such a problem, In this paper, we introduce an optimized and highly efficient architecture for SR-GAN (generator) model by utilizing model compression techniques such as Knowledge Distillation and pruning, which work together to reduce the storage requirement of the model also increase in their performance. Our method begins with distilling the knowledge from a large pre-trained model to a lightweight model using different loss functions. Then, iterative weight pruning is applied to the distilled model to remove less significant weights based on their magnitude, resulting in a sparser network. Knowledge Distillation reduces the model size by 40%; pruning then reduces it further by 18%. To accelerate the learning process, we employ the Horovod framework for distributed training on a cluster of 2 nodes, each with 8 GPUs, resulting in improved training performance and faster convergence. Experimental results on various benchmarks demonstrate that the proposed compressed model significantly outperforms state-of-the-art methods in terms of peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM), and image quality for x4 super-resolution tasks.Keywords: single-image super-resolution, generative adversarial networks, knowledge distillation, pruning
Procedia PDF Downloads 10016429 The Design of a Mixed Matrix Model for Activity Levels Extraction and Sub Processes Classification of a Work Project (Case: Great Tehran Electrical Distribution Company)
Authors: Elham Allahmoradi, Bahman Allahmoradi, Ali Bonyadi Naeini
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Complex systems have many aspects. A variety of methods have been developed to analyze these systems. The most efficient of these methods should not only be simple, but also provide useful and comprehensive information about many aspects of the system. Matrix methods are considered the most commonly methods used to analyze and design systems. Each matrix method can examine a particular aspect of the system. If these methods are combined, managers can access to more comprehensive and broader information about the system. This study was conducted in four steps. In the first step, a process model of a real project has been extracted through IDEF3. In the second step, activity levels have been attained by writing a process model in the form of a design structure matrix (DSM) and sorting it through triangulation algorithm (TA). In the third step, sub-processes have been obtained by writing the process model in the form of an interface structure matrix (ISM) and clustering it through cluster identification algorithm (CIA). In the fourth step, a mixed model has been developed to provide a unified picture of the project structure through the simultaneous presentation of activities and sub-processes. Finally, the paper is completed with a conclusion.Keywords: integrated definition for process description capture (IDEF3) method, design structure matrix (DSM), interface structure matrix (ism), mixed matrix model, activity level, sub-process
Procedia PDF Downloads 49516428 Evaluating Performance of Value at Risk Models for the MENA Islamic Stock Market Portfolios
Authors: Abderrazek Ben Maatoug, Ibrahim Fatnassi, Wassim Ben Ayed
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In this paper we investigate the issue of market risk quantification for Middle East and North Africa (MENA) Islamic market equity. We use Value-at-Risk (VaR) as a measure of potential risk in Islamic stock market, for long and short position, based on Riskmetrics model and the conditional parametric ARCH class model volatility with normal, student and skewed student distribution. The sample consist of daily data for the 2006-2014 of 11 Islamic stock markets indices. We conduct Kupiec and Engle and Manganelli tests to evaluate the performance for each model. The main finding of our empirical results show that (i) the superior performance of VaR models based on the Student and skewed Student distribution, for the significance level of α=1% , for all Islamic stock market indices, and for both long and short trading positions (ii) Risk Metrics model, and VaR model based on conditional volatility with normal distribution provides the best accurate VaR estimations for both long and short trading positions for a significance level of α=5%.Keywords: value-at-risk, risk management, islamic finance, GARCH models
Procedia PDF Downloads 59216427 Doing Cause-and-Effect Analysis Using an Innovative Chat-Based Focus Group Method
Authors: Timothy Whitehill
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This paper presents an innovative chat-based focus group method for collecting qualitative data to construct a cause-and-effect analysis in business research. This method was developed in response to the research and data collection challenges faced by the Covid-19 outbreak in the United Kingdom during 2020-21. This paper discusses the methodological approaches and builds a contemporary argument for its effectiveness in exploring cause-and-effect relationships in the context of focus group research, systems thinking and problem structuring methods. The pilot for this method was conducted between October 2020 and March 2021 and collected more than 7,000 words of chat-based data which was used to construct a consensus drawn cause-and-effect analysis. This method was developed in support of an ongoing Doctorate in Business Administration (DBA) thesis, which is using Design Science Research methodology to operationalize organisational resilience in UK construction sector firms.Keywords: cause-and-effect analysis, focus group research, problem structuring methods, qualitative research, systems thinking
Procedia PDF Downloads 22416426 Structural Breaks, Asymmetric Effects and Long Memory in the Volatility of Turkey Stock Market
Authors: Serpil Türkyılmaz, Mesut Balıbey
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In this study, long memory properties in volatility of Turkey Stock Market are being examined through the FIGARCH, FIEGARCH and FIAPARCH models under different distribution assumptions as normal and skewed student-t distributions. Furthermore, structural changes in volatility of Turkey Stock Market are investigated. The results display long memory property and the presence of asymmetric effects of shocks in volatility of Turkey Stock Market.Keywords: FIAPARCH model, FIEGARCH model, FIGARCH model, structural break
Procedia PDF Downloads 29216425 Effective Emergency Response and Disaster Prevention: A Decision Support System for Urban Critical Infrastructure Management
Authors: M. Shahab Uddin, Pennung Warnitchai
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Currently more than half of the world’s populations are living in cities, and the number and sizes of cities are growing faster than ever. Cities rely on the effective functioning of complex and interdependent critical infrastructures networks to provide public services, enhance the quality of life, and save the community from hazards and disasters. In contrast, complex connectivity and interdependency among the urban critical infrastructures bring management challenges and make the urban system prone to the domino effect. Unplanned rapid growth, increased connectivity, and interdependency among the infrastructures, resource scarcity, and many other socio-political factors are affecting the typical state of an urban system and making it susceptible to numerous sorts of diversion. In addition to internal vulnerabilities, urban systems are consistently facing external threats from natural and manmade hazards. Cities are not just complex, interdependent system, but also makeup hubs of the economy, politics, culture, education, etc. For survival and sustainability, complex urban systems in the current world need to manage their vulnerabilities and hazardous incidents more wisely and more interactively. Coordinated management in such systems makes for huge potential when it comes to absorbing negative effects in case some of its components were to function improperly. On the other hand, ineffective management during a similar situation of overall disorder from hazards devastation may make the system more fragile and push the system to an ultimate collapse. Following the quantum, the current research hypothesizes that a hazardous event starts its journey as an emergency, and the system’s internal vulnerability and response capacity determine its destination. Connectivity and interdependency among the urban critical infrastructures during this stage may transform its vulnerabilities into dynamic damaging force. An emergency may turn into a disaster in the absence of effective management; similarly, mismanagement or lack of management may lead the situation towards a catastrophe. Situation awareness and factual decision-making is the key to win a battle. The current research proposed a contextual decision support system for an urban critical infrastructure system while integrating three different models: 1) Damage cascade model which demonstrates damage propagation among the infrastructures through their connectivity and interdependency, 2) Restoration model, a dynamic restoration process of individual infrastructure, which is based on facility damage state and overall disruptions in surrounding support environment, and 3) Optimization model that ensures optimized utilization and distribution of available resources in and among the facilities. All three models are tightly connected, mutually interdependent, and together can assess the situation and forecast the dynamic outputs of every input. Moreover, this integrated model will hold disaster managers and decision makers responsible when it comes to checking all the alternative decision before any implementation, and support to produce maximum possible outputs from the available limited inputs. This proposed model will not only support to reduce the extent of damage cascade but will ensure priority restoration and optimize resource utilization through adaptive and collaborative management. Complex systems predictably fail but in unpredictable ways. System understanding, situation awareness, and factual decisions may significantly help urban system to survive and sustain.Keywords: disaster prevention, decision support system, emergency response, urban critical infrastructure system
Procedia PDF Downloads 22916424 A Geospatial Approach to Coastal Vulnerability Using Satellite Imagery and Coastal Vulnerability Index: A Case Study Mauritius
Authors: Manta Nowbuth, Marie Anais Kimberley Therese
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The vulnerability of coastal areas to storm surges stands as a critical global concern. The increasing frequency and intensity of extreme weather events have increased the risks faced by communities living along the coastlines Worldwide. Small Island developing states (SIDS) stands out as being exceptionally vulnerable, coastal regions, ecosystems of human habitation and natural forces, bear witness to the frontlines of climate-induced challenges, and the intensification of storm surges underscores the urgent need for a comprehensive understanding of coastal vulnerability. With limited landmass, low-lying terrains, and resilience on coastal resources, SIDS face an amplified vulnerability to the consequences of storm surges, the delicate balance between human activities and environmental dynamics in these island nations increases the urgency of tailored strategies for assessing and mitigating coastal vulnerability. This research uses an approach to evaluate the vulnerability of coastal communities in Mauritius. The Satellite imagery analysis makes use of sentinel satellite imageries, modified normalised difference water index, classification techniques and the DSAS add on to quantify the extent of shoreline erosion or accumulation, providing a spatial perspective on coastal vulnerability. The coastal Vulnerability Index (CVI) is applied by Gonitz et al Formula, this index considers factors such as coastal slope, sea level rise, mean significant wave height, and tidal range. Weighted assessments identify regions with varying levels of vulnerability, ranging from low to high. The study was carried out in a Village Located in the south of Mauritius, namely Rivière des Galets, with a population of about 500 people over an area of 60,000m². The Village of Rivière des Galets being located in the south, and the southern coast of Mauritius being exposed to the open Indian ocean, is vulnerable to swells, The swells generated by the South east trade winds can lead to large waves and rough sea conditions along the Southern Coastline which has an impact on the coastal activities, including fishing, tourism and coastal Infrastructures, hence, On the one hand, the results highlighted that from a stretch of 123km of coastline the linear rate regression for the 5 –year span varies from-24.1m/yr. to 8.2m/yr., the maximum rate of change in terms of eroded land is -24m/yr. and the maximum rate of accretion is 8.2m/yr. On the other hand, the coastal vulnerability index varies from 9.1 to 45.6 and it was categorised into low, moderate, high and very high risks zones. It has been observed that region which lacks protective barriers and are made of sandy beaches are categorised as high risks zone and hence it is imperative to high risk regions for immediate attention and intervention, as they will most likely be exposed to coastal hazards and impacts from climate change, which demands proactive measures for enhanced resilience and sustainable adaptation strategies.Keywords: climate change, coastal vulnerability, disaster management, remote sensing, satellite imagery, storm surge
Procedia PDF Downloads 1316423 The Effect of Al Andalus Improvement Model on the Teachers Performance and Their High School Students' Skills Acquiring
Authors: Sobhy Fathy A. Hashesh
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The study was carried out in the High School Classes of Andalus Private Schools, boys section, using control and experimental groups that were randomly assigned. The study investigated the effect of Al-Andalus Improvement Model (AIM) on the development of students’ skills acquiring. The society of the study composed of Al-Andalus Private Schools, high school students, boys Section (N=700), while the sample of the study composed of four randomly assigned groups two groups of teachers (N=16) and two groups of students (N=42) with one experimental group and one control group for teachers and their students respectively. The study followed the quantitative and qualitative approaches in collecting and analyzing data to investigate the study hypotheses. Results of the study revealed that there were significant statistical differences in teachers’ performances and students' skills acquiring for the favor of the experimental groups and there was a strong correlation between the teachers performances and the students skills acquiring. The study recommended the implementation of the AIM model for the sake of teachers performances and students’ learning outcomes.Keywords: AIM, improvement model, Classera, Al-Andalus Improvement Model.
Procedia PDF Downloads 16716422 Translation Quality Assessment: Proposing a Linguistic-Based Model for Translation Criticism with Considering Ideology and Power Relations
Authors: Mehrnoosh Pirhayati
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In this study, the researcher tried to propose a model of Translation Criticism (TC) regarding the phenomenon of Translation Quality Assessment (TQA). With changing the general view on re/writing as an illegal act, the researcher defined a scale for the act of translation and determined the redline of translation with other products. This research attempts to show TC as a related phenomenon to TQA. This study shows that TQA with using the rules and factors of TC as depicted in both product-oriented analysis and process-oriented analysis, determines the orientation or the level of the quality of translation. This study also depicts that TC, regarding TQA’s perspective, reveals the aim of the translation of original text and the root of ideological manipulation and re/writing. On the other hand, this study stresses the existence of a direct relationship between the linguistic materials and semiotic codes of a text or book. This study can be fruitful for translators, scholars, translation criticizers, and translation quality assessors, and also it is applicable in the area of pedagogy.Keywords: a model of translation criticism, a model of translation quality assessment, critical discourse analysis (CDA), re/writing, translation criticism (TC), translation quality assessment (TQA)
Procedia PDF Downloads 32216421 Optimization of Highly Oriented Pyrolytic Graphite Crystals for Neutron Optics
Authors: Hao Qu, Xiang Liu, Michael Crosby, Brian Kozak, Andreas K. Freund
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The outstanding performance of highly oriented pyrolytic graphite (HOPG) as an optical element for neutron beam conditioning is unequaled by any other crystalline material in the applications of monochromator, analyzer, and filter. This superiority stems from the favorable nuclear properties of carbon (small absorption and incoherent scattering cross-sections, big coherent scattering length) and the specific crystalline structure (small thermal diffuse scattering cross-section, layered crystal structure). The real crystal defect structure revealed by imaging techniques is correlated with the parameters used in the mosaic model (mosaic spread, mosaic block size, uniformity). The diffraction properties (rocking curve width as determined by both the intrinsic mosaic spread and the diffraction process, peak and integrated reflectivity, filter transmission) as a function of neutron wavelength or energy can be predicted with high accuracy and reliability by diffraction theory using empirical primary extinction coefficients extracted from a great amount of existing experimental data. The results of these calculations are given as graphs and tables permitting to optimize HOPG characteristics (mosaic spread, thickness, curvature) for any given experimental situation.Keywords: neutron optics, pyrolytic graphite, mosaic spread, neutron scattering, monochromator, analyzer
Procedia PDF Downloads 14316420 Estimation of the Parameters of Muskingum Methods for the Prediction of the Flood Depth in the Moudjar River Catchment
Authors: Fares Laouacheria, Said Kechida, Moncef Chabi
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The objective of the study was based on the hydrological routing modelling for the continuous monitoring of the hydrological situation in the Moudjar river catchment, especially during floods with Hydrologic Engineering Center–Hydrologic Modelling Systems (HEC-HMS). The HEC-GeoHMS was used to transform data from geographic information system (GIS) to HEC-HMS for delineating and modelling the catchment river in order to estimate the runoff volume, which is used as inputs to the hydrological routing model. Two hydrological routing models were used, namely Muskingum and Muskingum routing models, for conducting this study. In this study, a comparison between the parameters of the Muskingum and Muskingum-Cunge routing models in HEC-HMS was used for modelling flood routing in the Moudjar river catchment and determining the relationship between these parameters and the physical characteristics of the river. The results indicate that the effects of input parameters such as the weighting factor "X" and travel time "K" on the output results are more significant, where the Muskingum routing model was more sensitive to input parameters than the Muskingum-Cunge routing model. This study can contribute to understand and improve the knowledge of the mechanisms of river floods, especially in ungauged river catchments.Keywords: HEC-HMS, hydrological modelling, Muskingum routing model, Muskingum-Cunge routing model
Procedia PDF Downloads 27816419 A User Study on the Adoption of Context-Aware Destination Mobile Applications
Authors: Shu-Lu Hsu, Fang-Yi Chu
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With the advances in information and communications technology, mobile context-aware applications have become powerful marketing tools. In Apple online store, there are numerous mobile applications (APPs) developed for destination tour. This study investigated the determinants of adoption of context-aware APPs for destination tour services. A model is proposed based on Technology Acceptance Model and privacy concern theory. The model was empirically tested based on a sample of 259 users of a tourism APP published by Kaohsiung Tourism Bureau, Taiwan. The results showed that the fitness of the model is well and, among all the factors, the perceived usefulness and perceived ease of use have the most significant influences on the intention to adopt context-aware destination APPs. Finally, contrary to the findings of previous literature, the effect of privacy concern on the adoption intention of context-aware APP is insignificant.Keywords: mobile application, context-aware, privacy concern, TAM
Procedia PDF Downloads 25916418 Asymmetrical Informative Estimation for Macroeconomic Model: Special Case in the Tourism Sector of Thailand
Authors: Chukiat Chaiboonsri, Satawat Wannapan
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This paper used an asymmetric informative concept to apply in the macroeconomic model estimation of the tourism sector in Thailand. The variables used to statistically analyze are Thailand international and domestic tourism revenues, the expenditures of foreign and domestic tourists, service investments by private sectors, service investments by the government of Thailand, Thailand service imports and exports, and net service income transfers. All of data is a time-series index which was observed between 2002 and 2015. Empirically, the tourism multiplier and accelerator were estimated by two statistical approaches. The first was the result of the Generalized Method of Moments model (GMM) based on the assumption which the tourism market in Thailand had perfect information (Symmetrical data). The second was the result of the Maximum Entropy Bootstrapping approach (MEboot) based on the process that attempted to deal with imperfect information and reduced uncertainty in data observations (Asymmetrical data). In addition, the tourism leakages were investigated by a simple model based on the injections and leakages concept. The empirical findings represented the parameters computed from the MEboot approach which is different from the GMM method. However, both of the MEboot estimation and GMM model suggests that Thailand’s tourism sectors are in a period capable of stimulating the economy.Keywords: TThailand tourism, Maximum Entropy Bootstrapping approach, macroeconomic model, asymmetric information
Procedia PDF Downloads 29516417 An Investigation of a Three-Dimensional Constitutive Model of Gas Diffusion Layers in Polymer Electrolyte Membrane Fuel Cells
Authors: Yanqin Chen, Chao Jiang, Chongdu Cho
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This research presents the three-dimensional mechanical characteristics of a commercial gas diffusion layer by experiment and simulation results. Although the mechanical performance of gas diffusion layers has attracted much attention, its reliability and accuracy are still a major challenge. With the help of simulation analysis methods, it is beneficial to the gas diffusion layer’s extensive commercial development and the overall stress analysis of proton electrolyte membrane fuel cells during its pre-production design period. Therefore, in this paper, a three-dimensional constitutive model of a commercial gas diffusion layer, including its material stiffness matrix parameters, is developed and coded, in the user-defined material model of a commercial finite element method software for simulation. Then, the model is validated by comparing experimental results as well as simulation outcomes. As a result, both the experimental data and simulation results show a good agreement with each other, with high accuracy.Keywords: gas diffusion layer, proton electrolyte membrane fuel cell, stiffness matrix, three-dimensional mechanical characteristics, user-defined material model
Procedia PDF Downloads 16216416 Spatio-Temporal Pest Risk Analysis with ‘BioClass’
Authors: Vladimir A. Todiras
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Spatio-temporal models provide new possibilities for real-time action in pest risk analysis. It should be noted that estimation of the possibility and probability of introduction of a pest and of its economic consequences involves many uncertainties. We present a new mapping technique that assesses pest invasion risk using online BioClass software. BioClass is a GIS tool designed to solve multiple-criteria classification and optimization problems based on fuzzy logic and level set methods. This research describes a method for predicting the potential establishment and spread of a plant pest into new areas using a case study: corn rootworm (Diabrotica spp.), tomato leaf miner (Tuta absoluta) and plum fruit moth (Grapholita funebrana). Our study demonstrated that in BioClass we can combine fuzzy logic and geographic information systems with knowledge of pest biology and environmental data to derive new information for decision making. Pests are sensitive to a warming climate, as temperature greatly affects their survival and reproductive rate and capacity. Changes have been observed in the distribution, frequency and severity of outbreaks of Helicoverpa armigera on tomato. BioClass has demonstrated to be a powerful tool for applying dynamic models and map the potential future distribution of a species, enable resource to make decisions about dangerous and invasive species management and control.Keywords: classification, model, pest, risk
Procedia PDF Downloads 28216415 Optimizing CNC Production Line Efficiency Using NSGA-II: Adaptive Layout and Operational Sequence for Enhanced Manufacturing Flexibility
Authors: Yi-Ling Chen, Dung-Ying Lin
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In the manufacturing process, computer numerical control (CNC) machining plays a crucial role. CNC enables precise machinery control through computer programs, achieving automation in the production process and significantly enhancing production efficiency. However, traditional CNC production lines often require manual intervention for loading and unloading operations, which limits the production line's operational efficiency and production capacity. Additionally, existing CNC automation systems frequently lack sufficient intelligence and fail to achieve optimal configuration efficiency, resulting in the need for substantial time to reconfigure production lines when producing different products, thereby impacting overall production efficiency. Using the NSGA-II algorithm, we generate production line layout configurations that consider field constraints and select robotic arm specifications from an arm list. This allows us to calculate loading and unloading times for each job order, perform demand allocation, and assign processing sequences. The NSGA-II algorithm is further employed to determine the optimal processing sequence, with the aim of minimizing demand completion time and maximizing average machine utilization. These objectives are used to evaluate the performance of each layout, ultimately determining the optimal layout configuration. By employing this method, it enhance the configuration efficiency of CNC production lines and establish an adaptive capability that allows the production line to respond promptly to changes in demand. This will minimize production losses caused by the need to reconfigure the layout, ensuring that the CNC production line can maintain optimal efficiency even when adjustments are required due to fluctuating demands.Keywords: evolutionary algorithms, multi-objective optimization, pareto optimality, layout optimization, operations sequence
Procedia PDF Downloads 2416414 Numerical Investigation and Optimization of the Effect of Number of Blade and Blade Type on the Suction Pressure and Outlet Mass Flow Rate of a Centrifugal Fan
Authors: Ogan Karabas, Suleyman Yigit
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Number of blade and blade type of centrifugal fans are the most decisive factor on the field of application, noise level, suction pressure and outlet mass flow rate. Nowadays, in order to determine these effects on centrifugal fans, numerical studies are carried out in addition to experimental studies. In this study, it is aimed to numerically investigate the changes of suction pressure and outlet mass flow rate values of a centrifugal fan according to the number of blade and blade type. Centrifugal fans of the same size with forward, backward and straight blade type were analyzed by using a simulation program and compared with each other. This analysis was carried out under steady state condition by selecting k-Ɛ turbulence model and air is assumed incompressible. Then, 16, 32 and 48 blade centrifugal fans were again analyzed by using same simulation program, and the optimum number of blades was determined for the suction pressure and the outlet mass flow rate. According to the results of the analysis, it was obtained that the suction pressure in the 32 blade fan was twice the value obtained in the 16 blade fan. In addition, the outlet mass flow rate increased by 45% with the increase in the number of blade from 16 to 32. There is no significant change observed on the suction pressure and outlet mass flow rate when the number of blades increased from 32 to 48. In the light of the analysis results, the optimum blade number was determined as 32.Keywords: blade type, centrifugal fan, cfd, outlet mass flow rate, suction pressure
Procedia PDF Downloads 40516413 Social Justice-Focused Mental Health Practice: An Integrative Model for Clinical Social Work
Authors: Hye-Kyung Kang
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Social justice is a central principle of the social work profession and education. However, scholars have long questioned the profession’s commitment to putting social justice values into practice. Clinical social work has been particularly criticized for its lack of attention to social justice and for failing to address the concerns of the oppressed. One prominent criticism of clinical social work is that it often relies on individual intervention and fails to take on system-level changes or advocacy. This concern evokes the historical macro-micro tension of the social work profession where micro (e.g., mental health counseling) and macro (e.g., policy advocacy) practices are conceptualized as separate domains, creating a false binary for social workers. One contributor to this false binary seems to be that most clinical practice models do not prepare social work students and practitioners to make a clear link between clinical practice and social justice. This paper presents a model of clinical social work practice that clearly recognizes the essential and necessary connection between social justice, advocacy, and clinical practice throughout the clinical process: engagement, assessment, intervention, and evaluation. Contemporary relational theories, critical social work frameworks, and anti-oppressive practice approaches are integrated to build a clinical social work practice model that addresses the urgent need for mental health practice that not only helps and heals the person but also challenges societal oppressions and aims to change them. The application of the model is presented through case vignettes.Keywords: social justice, clinical social work, clinical social work model, integrative model
Procedia PDF Downloads 8816412 A Sliding Model Control for a Hybrid Hyperbolic Dynamic System
Authors: Xuezhang Hou
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In the present paper, a hybrid hyperbolic dynamic system formulated by partial differential equations with initial and boundary conditions is considered. First, the system is transformed to an abstract evolution system in an appropriate Hilbert space, and spectral analysis and semigroup generation of the system operator is discussed. Subsequently, a sliding model control problem is proposed and investigated, and an equivalent control method is introduced and applied to the system. Finally, a significant result that the state of the system can be approximated by an ideal sliding mode under control in any accuracy is derived and examined.Keywords: hyperbolic dynamic system, sliding model control, semigroup of linear operators, partial differential equations
Procedia PDF Downloads 13816411 Effects of an Educative Model in Socially Responsible Behavior and Other Psychological Variables
Authors: Gracia V. Navarro, Maria V. Gonzalez, Carlos G. Reed
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The eudaimonic perspective in philosophy and psychology suggests that a good life is closely related to developing oneself in order to contribute to the well-being and happiness of other people and of the world as a whole. Educational psychology can help to achieve this through the design and validation of educative models. Since 2004, the University of Concepcion and other Chilean universities apply an educative model to train socially responsible professionals, people that in the exercise of their profession contribute to generate equity for the development and assess the impacts of their decisions, opting for those that serve the common good. The main aim is to identify if a relationship exists between achieved learning, attitudes toward social responsibility, self-attribution of socially responsible behavior, value type, professional behavior observed and, participation in a specific model to train socially responsible (SR) professionals. The Achieved Learning and Attitudes Toward Social Responsibility Questionnaire, interview with employers and Values Questionnaire and Self-attribution of SR Behavior Questionnaire is applied to 394 students and graduates, divided into experimental and control groups (trained and not trained under the educative model), in order to identify the professional behavior of the graduates. The results show that students and graduates perceive cognitive, affective and behavioral learning, with significant differences in attitudes toward social responsibility and self-attribution of SR behavior, between experimental and control. There are also differences in employers' perceptions about the professional practice of those who were trained under the model and those who were not. It is concluded that the educative model has an impact on the learning of social responsibility and educates for a full life. It is also concluded that it is necessary to identify mediating variables of the model effect.Keywords: educative model, good life, professional social responsibility, values
Procedia PDF Downloads 26716410 Analysis on Prediction Models of TBM Performance and Selection of Optimal Input Parameters
Authors: Hang Lo Lee, Ki Il Song, Hee Hwan Ryu
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An accurate prediction of TBM(Tunnel Boring Machine) performance is very difficult for reliable estimation of the construction period and cost in preconstruction stage. For this purpose, the aim of this study is to analyze the evaluation process of various prediction models published since 2000 for TBM performance, and to select the optimal input parameters for the prediction model. A classification system of TBM performance prediction model and applied methodology are proposed in this research. Input and output parameters applied for prediction models are also represented. Based on these results, a statistical analysis is performed using the collected data from shield TBM tunnel in South Korea. By performing a simple regression and residual analysis utilizinFg statistical program, R, the optimal input parameters are selected. These results are expected to be used for development of prediction model of TBM performance.Keywords: TBM performance prediction model, classification system, simple regression analysis, residual analysis, optimal input parameters
Procedia PDF Downloads 30916409 Ubiquitous Collaborative Mobile Learning (UCML): A Flexible Instructional Design Model for Social Learning
Authors: Hameed Olalekan Bolaji
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The digital natives are driving the trends of literacy in the use of electronic devices for learning purposes. This has reconfigured the context of learning in the exploration of knowledge in a social learning environment. This study explores the impact of Ubiquitous Collaborative Mobile Learning (UCML) instructional design model in a quantitative designed-based research approach. The UCML model was a synergetic blend of four models that are relevant to the design of instructional content for a social learning environment. The UCML model serves as the treatment and instructions were transmitted via mobile device based on the principle of ‘bring your own device’ (BYOD) to promote social learning. Three research questions and two hypotheses were raised to guide the conduct of this study. A researcher-designed questionnaire was used to collate data and the it was subjected to reliability of Cronbach Alpha which yielded 0.91. Descriptive statistics of mean and standard deviation were used to answer research questions while inferential statistics of independent sample t-test was used to analyze the hypotheses. The findings reveal that the UCML model was adequately evolved and it promotes social learning its design principles through the use of mobile devices.Keywords: collaboration, mobile device, social learning, ubiquitous
Procedia PDF Downloads 15916408 Effects of Level Densities and Those of a-Parameter in the Framework of Preequilibrium Model for 63,65Cu(n,xp) Reactions in Neutrons at 9 to 15 MeV
Authors: L. Yettou
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In this study, the calculations of proton emission spectra produced by 63Cu(n,xp) and 65Cu(n,xp) reactions are used in the framework of preequilibrium models using the EMPIRE code and TALYS code. Exciton Model predidtions combined with the Kalbach angular distribution systematics and the Hybrid Monte Carlo Simulation (HMS) were used. The effects of levels densities and those of a-parameter have been investigated for our calculations. The comparison with experimental data shows clear improvement over the Exciton Model and HMS calculations.Keywords: Preequilibrium models , level density, level density a-parameter., Empire code, Talys code.
Procedia PDF Downloads 13516407 Best Resource Recommendation for a Stochastic Process
Authors: Likewin Thomas, M. V. Manoj Kumar, B. Annappa
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The aim of this study was to develop an Artificial Neural Network0 s recommendation model for an online process using the complexity of load, performance, and average servicing time of the resources. Here, the proposed model investigates the resource performance using stochastic gradient decent method for learning ranking function. A probabilistic cost function is implemented to identify the optimal θ values (load) on each resource. Based on this result the recommendation of resource suitable for performing the currently executing task is made. The test result of CoSeLoG project is presented with an accuracy of 72.856%.Keywords: ADALINE, neural network, gradient decent, process mining, resource behaviour, polynomial regression model
Procedia PDF Downloads 391