Search results for: model laws
13197 Estimation of Sediment Transport into a Reservoir Dam
Authors: Kiyoumars Roushangar, Saeid Sadaghian
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Although accurate sediment load prediction is very important in planning, designing, operating and maintenance of water resources structures, the transport mechanism is complex, and the deterministic transport models are based on simplifying assumptions often lead to large prediction errors. In this research, firstly, two intelligent ANN methods, Radial Basis and General Regression Neural Networks, are adopted to model of total sediment load transport into Madani Dam reservoir (north of Iran) using the measured data and then applicability of the sediment transport methods developed by Engelund and Hansen, Ackers and White, Yang, and Toffaleti for predicting of sediment load discharge are evaluated. Based on comparison of the results, it is found that the GRNN model gives better estimates than the sediment rating curve and mentioned classic methods.Keywords: sediment transport, dam reservoir, RBF, GRNN, prediction
Procedia PDF Downloads 49613196 MapReduce Algorithm for Geometric and Topological Information Extraction from 3D CAD Models
Authors: Ahmed Fradi
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In a digital world in perpetual evolution and acceleration, data more and more voluminous, rich and varied, the new software solutions emerged with the Big Data phenomenon offer new opportunities to the company enabling it not only to optimize its business and to evolve its production model, but also to reorganize itself to increase competitiveness and to identify new strategic axes. Design and manufacturing industrial companies, like the others, face these challenges, data represent a major asset, provided that they know how to capture, refine, combine and analyze them. The objective of our paper is to propose a solution allowing geometric and topological information extraction from 3D CAD model (precisely STEP files) databases, with specific algorithm based on the programming paradigm MapReduce. Our proposal is the first step of our future approach to 3D CAD object retrieval.Keywords: Big Data, MapReduce, 3D object retrieval, CAD, STEP format
Procedia PDF Downloads 54013195 Regulation, Evaluation and Incentives: An Analysis of Management Characteristics of Nonprofit Organizations in China
Authors: Wuqi Yang, Sufeng Li, Linda Zhai, Zhizhong Yuan, Shengli Wang
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How to assess and evaluate a not-for-profit (NFP) organisation’s performance should be of concern to all stakeholders because, amongst other things, without correctly evaluating its performance might affect an NFP being not able to continue to meet its service objectives. Given the growing importance of this sector in China, more and more existing and potential donors, governments and others are starting to take an increased interest in the financial conditions and performance of NFPs. However, when these various groups look for ways (methods) to assess the performance of NFPs, they find there has been relatively little research conducted into methods for assessing the performance of NFPs in China. Furthermore, there does not appear to have been any research to date into the performance evaluation of Chinese NFPs. The focus of this paper is to investigate how the Chinese government manages and evaluates not-for-profit (NFP) organisations' performances in China. Through examining and evaluating the NFPs in China from different aspects such as business development, mission fulfillment, financial position and other status, this paper finds some institutional constraints currently facing by the NFPs in China. At the end of this paper, a new regulatory framework is proposed for regulators’ considerations. The research methods are based on a combination of a literature review; using Balanced Scorecard to assess NFPs in China; Case Study method is employed to analyse a charity foundation’s performance in Hebei Province and proposing solutions to resolve the current issues and challenges facing by the NFPs. These solutions include: formulating laws and regulations on NFPs; simplifying management procedures, introducing tax incentives, providing financial support and other incentives to support the development of non-profit organizations in China. This study provides the first step towards a greater understanding of the NFP performance evaluation in China. It is expected that the findings and solutions from this study will be useful to anyone involved with the China NFP sector; particularly CEOs, managers, bankers, independent auditors and government agencies.Keywords: Chinese non-profit organizations, evaluation, management, supervision
Procedia PDF Downloads 17513194 Loss Function Optimization for CNN-Based Fingerprint Anti-Spoofing
Authors: Yehjune Heo
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As biometric systems become widely deployed, the security of identification systems can be easily attacked by various spoof materials. This paper contributes to finding a reliable and practical anti-spoofing method using Convolutional Neural Networks (CNNs) based on the types of loss functions and optimizers. The types of CNNs used in this paper include AlexNet, VGGNet, and ResNet. By using various loss functions including Cross-Entropy, Center Loss, Cosine Proximity, and Hinge Loss, and various loss optimizers which include Adam, SGD, RMSProp, Adadelta, Adagrad, and Nadam, we obtained significant performance changes. We realize that choosing the correct loss function for each model is crucial since different loss functions lead to different errors on the same evaluation. By using a subset of the Livdet 2017 database, we validate our approach to compare the generalization power. It is important to note that we use a subset of LiveDet and the database is the same across all training and testing for each model. This way, we can compare the performance, in terms of generalization, for the unseen data across all different models. The best CNN (AlexNet) with the appropriate loss function and optimizers result in more than 3% of performance gain over the other CNN models with the default loss function and optimizer. In addition to the highest generalization performance, this paper also contains the models with high accuracy associated with parameters and mean average error rates to find the model that consumes the least memory and computation time for training and testing. Although AlexNet has less complexity over other CNN models, it is proven to be very efficient. For practical anti-spoofing systems, the deployed version should use a small amount of memory and should run very fast with high anti-spoofing performance. For our deployed version on smartphones, additional processing steps, such as quantization and pruning algorithms, have been applied in our final model.Keywords: anti-spoofing, CNN, fingerprint recognition, loss function, optimizer
Procedia PDF Downloads 13613193 Semiparametric Regression Of Truncated Spline Biresponse On Farmer Loyalty And Attachment Modeling
Authors: Adji Achmad Rinaldo Fernandes
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Regression analysis is a statistical method that is able to describe and predict causal relationships between individuals. Not all relationships have a known curve shape; often, there are relationship patterns that cannot be known in the shape of the curve; besides that, a cause can have an impact on more than one effect, so that between effects can also have a close relationship in it. Regression analysis that can be done to find out the relationship can be brought closer to the semiparametric regression of truncated spline biresponse. The purpose of this study is to examine the function estimator and determine the best model of truncated spline biresponse semiparametric regression. The results of the secondary data study showed that the best model with the highest order of quadratic and a maximum of two knots with a Goodness of fit value in the form of Adjusted R2 of 88.5%.Keywords: biresponse, farmer attachment, farmer loyalty, truncated spline
Procedia PDF Downloads 3613192 Nelder-Mead Parametric Optimization of Elastic Metamaterials with Artificial Neural Network Surrogate Model
Authors: Jiaqi Dong, Qing-Hua Qin, Yi Xiao
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Some of the most fundamental challenges of elastic metamaterials (EMMs) optimization can be attributed to the high consumption of computational power resulted from finite element analysis (FEA) simulations that render the optimization process inefficient. Furthermore, due to the inherent mesh dependence of FEA, minuscule geometry features, which often emerge during the later stages of optimization, induce very fine elements, resulting in enormously high time consumption, particularly when repetitive solutions are needed for computing the objective function. In this study, a surrogate modelling algorithm is developed to reduce computational time in structural optimization of EMMs. The surrogate model is constructed based on a multilayer feedforward artificial neural network (ANN) architecture, trained with prepopulated eigenfrequency data prepopulated from FEA simulation and optimized through regime selection with genetic algorithm (GA) to improve its accuracy in predicting the location and width of the primary elastic band gap. With the optimized ANN surrogate at the core, a Nelder-Mead (NM) algorithm is established and its performance inspected in comparison to the FEA solution. The ANNNM model shows remarkable accuracy in predicting the band gap width and a reduction of time consumption by 47%.Keywords: artificial neural network, machine learning, mechanical metamaterials, Nelder-Mead optimization
Procedia PDF Downloads 12813191 Forecasting Model for Rainfall in Thailand: Case Study Nakhon Ratchasima Province
Authors: N. Sopipan
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In this paper, we study of rainfall time series of weather stations in Nakhon Ratchasima province in Thailand using various statistical methods enabled to analyse the behaviour of rainfall in the study areas. Time-series analysis is an important tool in modelling and forecasting rainfall. ARIMA and Holt-Winter models based on exponential smoothing were built. All the models proved to be adequate. Therefore, could give information that can help decision makers establish strategies for proper planning of agriculture, drainage system and other water resource applications in Nakhon Ratchasima province. We found the best perform for forecasting is ARIMA(1,0,1)(1,0,1)12.Keywords: ARIMA Models, exponential smoothing, Holt-Winter model
Procedia PDF Downloads 30013190 Development of Non-Intrusive Speech Evaluation Measure Using S-Transform and Light-Gbm
Authors: Tusar Kanti Dash, Ganapati Panda
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The evaluation of speech quality and intelligence is critical to the overall effectiveness of the Speech Enhancement Algorithms. Several intrusive and non-intrusive measures are employed to calculate these parameters. Non-Intrusive Evaluation is most challenging as, very often, the reference clean speech data is not available. In this paper, a novel non-intrusive speech evaluation measure is proposed using audio features derived from the Stockwell transform. These features are used with the Light Gradient Boosting Machine for the effective prediction of speech quality and intelligibility. The proposed model is analyzed using noisy and reverberant speech from four databases, and the results are compared with the standard Intrusive Evaluation Measures. It is observed from the comparative analysis that the proposed model is performing better than the standard Non-Intrusive models.Keywords: non-Intrusive speech evaluation, S-transform, light GBM, speech quality, and intelligibility
Procedia PDF Downloads 25913189 Space Vector Pulse Width Modulation Based Design and Simulation of a Three-Phase Voltage Source Converter Systems
Authors: Farhan Beg
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A space vector based pulse width modulation control technique for the three-phase PWM converter is proposed in this paper. The proposed control scheme is based on a synchronous reference frame model. High performance and efficiency is obtained with regards to the DC bus voltage and the power factor considerations of the PWM rectifier thus leading to low losses. MATLAB/SIMULINK are used as a platform for the simulations and a SIMULINK model is presented in the paper. The results show that the proposed model demonstrates better performance and properties compared to the traditional SPWM method and the method improves the dynamic performance of the closed loop drastically. For the space vector based pulse width modulation, sine signal is the reference waveform and triangle waveform is the carrier waveform. When the value of sine signal is larger than triangle signal, the pulse will start producing to high; and then when the triangular signals higher than sine signal, the pulse will come to low. SPWM output will change by changing the value of the modulation index and frequency used in this system to produce more pulse width. When more pulse width is produced, the output voltage will have lower harmonics contents and the resolution will increase.Keywords: power factor, SVPWM, PWM rectifier, SPWM
Procedia PDF Downloads 33513188 In vivo Mechanical Characterization of Facial Skin Combining Digital Image Correlation and Finite Element
Authors: Huixin Wei, Shibin Wang, Linan Li, Lei Zhou, Xinhao Tu
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Facial skin is a biomedical material with complex mechanical properties of anisotropy, viscoelasticity, and hyperelasticity. The mechanical properties of facial skin are crucial for a number of applications including facial plastic surgery, animation, dermatology, cosmetic industry, and impact biomechanics. Skin is a complex multi-layered material which can be broadly divided into three main layers, the epidermis, the dermis, and the hypodermis. Collagen fibers account for 75% of the dry weight of dermal tissue, and it is these fibers which are responsible for the mechanical properties of skin. Many research on the anisotropic mechanical properties are mainly concentrated on in vitro, but there is a great difference between in vivo and in vitro for mechanical properties of the skin. In this study, we presented a method to measure the mechanical properties of facial skin in vivo. Digital image correlation (DIC) and indentation tests were used to obtain the experiment data, including the deformation of facial surface and indentation force-displacement curve. Then, the experiment was simulated using a finite element (FE) model. Application of Computed Tomography (CT) and reconstruction techniques obtained the real tissue geometry. A three-dimensional FE model of facial skin, including a bi-layer system, was obtained. As the epidermis is relatively thin, the epidermis and dermis were regarded as one layer and below it was hypodermis in this study. The upper layer was modeled as a Gasser-Ogden-Holzapfel (GOH) model to describe hyperelastic and anisotropic behaviors of the dermis. The under layer was modeled as a linear elastic model. In conclusion, the material properties of two-layer were determined by minimizing the error between the FE data and experimental data.Keywords: facial skin, indentation test, finite element, digital image correlation, computed tomography
Procedia PDF Downloads 11213187 Brazilian Environmental Public Policies Analysis
Authors: Estela Macedo Alves
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This paper is an overview on public policy analysis focused on the study of Brazilian public policy making process. The methodology is based on the review of some theories on the subject, linking them to Brazilian reality. The study presents basic policy analysis concepts, such as policy, polity and politics. It is emphasized John Kingdon's Multiple Stream Model, because of its clarifying aspects concerning public policies formulation process in democratic countries. In this path it was possible to establish interpretations on environmental public policies in Brazil and understand its methods, instead of presenting only a case study. At the end, it is possible to connect theory with Brazilian reality, identifying negative and positive points of its political processes and structure.Keywords: Brazilian policies, environmental public policy, multiple stream model, public policy analysis
Procedia PDF Downloads 40713186 An Analytical Study on the Politics of Defection in India
Authors: Diya Sarkar, Prafulla C. Mishra
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In a parliamentary system, party discipline is the impulse; when it falls short, the government usually falls. Conceivably, the platform of Indian politics suffers with innumerous practical disorders. The politics of defection is one such specie entailing gross miscarriage of fair conduct turning politics into a game of thrones (powers). This practice of political nomaditude can trace its seed in the womb of British House of Commons. Therein, if a legislator was found to cross the floor, the party considered him disloyal. In other words, the legislator lost his allegiance to his former party by joining another party. This very phenomenon, in practice has a two way traffic i.e. ruling party to the opposition party or vice versa. The democracies like USA, Australia and Canada were also aware of this fashion of swapping loyalties. There have been several instances of great politicians changing party allegiance, for example Winston Churchill, Ramsay McDonald, William Gladstone etc. Nevertheless, it is interesting to cite that irrespective of such practice of changing party allegiance, none of the democracies in the west ever desired or felt the need to legislatively ban defections. But, exceptionally India can be traced to have passed anti-defection laws. The politics of defection had been a unique popular phenomenon on the floor of Indian Parliamentary system gradually gulping the democratic essence and synchronization of the Federation. This study is both analytical and doctrinal, which tries to examine whether representative democracy has lost its essence due to political nomadism. The present study also analyzes the classical as well as contemporary pulse of floor crossing amidst dynastic politics in a representative democracy. It will briefly discuss the panorama of defections under the Indian federal structure in the light of the anti-defection law and an attempt has been made to add valuable suggestions to streamline remedy for the still prevalent political defections.Keywords: constitutional law, defection, democracy, polarization, political anti-trust
Procedia PDF Downloads 37613185 Development of Equivalent Inelastic Springs to Model C-Devices
Authors: Oday Al-Mamoori, J. Enrique Martinez-Rueda
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'C' shape yielding devices (C-devices) are effective tools for introducing supplemental sources of energy dissipation by hysteresis. Studies have shown that C-devices made of mild steel can be successfully applied as integral parts of seismic retrofitting schemes. However, explicit modelling of these devices can become cumbersome, expensive and time consuming. The device under study in this article has been previously used in non-invasive dissipative bracing for seismic retrofitting. The device is cut from a mild steel plate and has an overall shape that resembles that of a rectangular portal frame with circular interior corner transitions to avoid stress concentration and to control the extension of the dissipative region of the device. A number of inelastic finite element (FE) analyses using either inelastic 2D plane stress elements or inelastic fibre frame elements are reported and used to calibrate a 1D equivalent inelastic spring model that effectively reproduces the cyclic response of the device. The more elaborate FE model accounts for the frictional forces developed between the steel plate and the bolts used to connect the C-device to structural members. FE results also allow the visualization of the inelastic regions of the device where energy dissipation is expected to occur. FE analysis results are in a good agreement with experimental observations.Keywords: C-device, equivalent nonlinear spring, FE analyses, reversed cyclic tests
Procedia PDF Downloads 15213184 Selection of Strategic Suppliers for Partnership: A Model with Two Stages Approach
Authors: Safak Isik, Ozalp Vayvay
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Strategic partnerships with suppliers play a vital role for the long-term value-based supply chain. This strategic collaboration keeps still being one of the top priority of many business organizations in order to create more additional value; benefiting mainly from supplier’s specialization, capacity and innovative power, securing supply and better managing costs and quality. However, many organizations encounter difficulties in initiating, developing and managing those partnerships and many attempts result in failures. One of the reasons for such failure is the incompatibility of members of this partnership or in other words wrong supplier selection which emphasize the significance of the selection process since it is the beginning stage. An effective selection process of strategic suppliers is critical to the success of the partnership. Although there are several research studies to select the suppliers in literature, only a few of them is related to strategic supplier selection for long-term partnership. The purpose of this study is to propose a conceptual model for the selection of strategic partnership suppliers. A two-stage approach has been used in proposed model incorporating first segmentation and second selection. In the first stage; considering the fact that not all suppliers are strategically equal and instead of a long list of potential suppliers, Kraljic’s purchasing portfolio matrix can be used for segmentation. This supplier segmentation is the process of categorizing suppliers based on a defined set of criteria in order to identify types of suppliers and determine potential suppliers for strategic partnership. In the second stage, from a pool of potential suppliers defined at first phase, a comprehensive evaluation and selection can be performed to finally define strategic suppliers considering various tangible and intangible criteria. Since a long-term relationship with strategic suppliers is anticipated, criteria should consider both current and future status of the supplier. Based on an extensive literature review; strategical, operational and organizational criteria have been determined and elaborated. The result of the selection can also be used to determine suppliers who are not ready for a partnership but to be developed for strategic partnership. Since the model is based on multiple criteria for both stages, it provides a framework for further utilization of Multi-Criteria Decision Making (MCDM) techniques. The model may also be applied to a wide range of industries and involve managerial features in business organizations.Keywords: Kraljic’s matrix, purchasing portfolio, strategic supplier selection, supplier collaboration, supplier partnership, supplier segmentation
Procedia PDF Downloads 23913183 Effects of Transtheoretical Model in Obese and Overweight Women Nutritional Behavior Change and Lose Weight
Authors: Abdmohammad Mousavi, Mohsen Shams, Mehdi Akbartabar Toori, Ali Mousavizadeh, Mohammad Ali Morowatisharifabad
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The effectiveness of Transtheoretical Model (TTM) on nutritional behavior change and lose weight has been subject to questions by some studies. The objective of this study was to determine the effect of nutritional behavior change and lose weight interventions based on TTM in obese and overweight women. This experimental study that was a 8 months trial nutritional behavior change and weight loss program based on TTM with two conditions and pre–post intervention measurements weight mean. 299 obese and overweight 20-44 years old women were selected from two health centers include training (142) and control (157) groups in Yasuj, a city in south west of Iran. Data were analyzed using paired T-test and One–Way ANOVA tests. In baseline, adherence with nutritional healthy behavior in training group(9.4%) compare with control(38.8%) were different significantly(p=.003), weight mean of training(Mean=78.02 kg, SD=11.67) compared with control group(Mean=77.23 kg, SD=10.25) were not (P=.66). In post test, adherence with nutritional healthy behavior in training group(70.1%) compare with control (37.4%) were different significantly (p=.000), weight mean of training (Mean=74.65 kg, SD=10.93, p=.000) compare with pre test were different significantly and control (Mean=77.43 kg, SD=10.43, p=.411) were not. The training group has lost 3.37 kg weight, whereas the control group has increased .2 kg weight. These results supported the applicability of the TTM for women weight lose intervention.Keywords: nutritional behavior, Transtheoretical Model, weight lose, women
Procedia PDF Downloads 48413182 Accountant Strategists Challenge the Dominant Business Model: A Strategy-as-Practice Perspective
Authors: Lindie Grebe
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This paper reports on a study that explored the strategizing practices of professional accountants in the mining industry, based on Jarratt and Stiles’ dominant strategizing practice models framework. Drawing on a strategy-as-practice perspective, the paper recognises qualified professional accountants in strategic management such as Chief Executive Officers, as strategy practitioners that perform their strategizing practices and praxis within a specific context. The main findings of this paper were produced through semi-structured individual interviews with accountants that perform strategy on a business level in the South African mining industry. Qualitative data were analysed through conversation analysis over two coding-cycles. Findings describe accountant strategists as practitioners who challenge the dominant business model when a disconnect seems to exist between international corporate level strategy and business level strategy in the South African mining industry. Accountant strategy practitioners described their dominant strategizing practice model as incremental change during strategic planning and as a lived experience during strategy implementation. Findings portrayed these strategists as taking initiative as strategy leaders in a dynamic and volatile environment to combine their accounting background with strategic management and challenge the dominant business model. Understanding how accountant strategists perform strategizing offers insight into the social practice of strategic management. This understanding contributes to the body of knowledge on strategizing in the South African mining industry. In addition, knowledge on the transformation of accountants as strategists could provide valuable practice relevant insights for accounting educators and the accounting profession alike.Keywords: accountant strategists, dominant strategizing practice models framework, mining industry, strategy-as-practice
Procedia PDF Downloads 17513181 Optimal Opportunistic Maintenance Policy for a Two-Unit System
Authors: Nooshin Salari, Viliam Makis, Jane Doe
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This paper presents a maintenance policy for a system consisting of two units. Unit 1 is gradually deteriorating and is subject to soft failure. Unit 2 has a general lifetime distribution and is subject to hard failure. Condition of unit 1 of the system is monitored periodically and it is considered as failed when its deterioration level reaches or exceeds a critical level N. At the failure time of unit 2 system is considered as failed, and unit 2 will be correctively replaced by the next inspection epoch. Unit 1 or 2 are preventively replaced when deterioration level of unit 1 or age of unit 2 exceeds the related preventive maintenance (PM) levels. At the time of corrective or preventive replacement of unit 2, there is an opportunity to replace unit 1 if its deterioration level reaches the opportunistic maintenance (OM) level. If unit 2 fails in an inspection interval, system stops operating although unit 1 has not failed. A mathematical model is derived to find the preventive and opportunistic replacement levels for unit 1 and preventive replacement age for unit 2, that minimize the long run expected average cost per unit time. The problem is formulated and solved in the semi-Markov decision process (SMDP) framework. Numerical example is provided to illustrate the performance of the proposed model and the comparison of the proposed model with an optimal policy without opportunistic maintenance level for unit 1 is carried out.Keywords: condition-based maintenance, opportunistic maintenance, preventive maintenance, two-unit system
Procedia PDF Downloads 20013180 Probabilistic Simulation of Triaxial Undrained Cyclic Behavior of Soils
Authors: Arezoo Sadrinezhad, Kallol Sett, S. I. Hariharan
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In this paper, a probabilistic framework based on Fokker-Planck-Kolmogorov (FPK) approach has been applied to simulate triaxial cyclic constitutive behavior of uncertain soils. The framework builds upon previous work of the writers, and it has been extended for cyclic probabilistic simulation of triaxial undrained behavior of soils. von Mises elastic-perfectly plastic material model is considered. It is shown that by using probabilistic framework, some of the most important aspects of soil behavior under cyclic loading can be captured even with a simple elastic-perfectly plastic constitutive model.Keywords: elasto-plasticity, uncertainty, soils, fokker-planck equation, fourier spectral method, finite difference method
Procedia PDF Downloads 37913179 Kirchhoff’s Depth Migration over Heterogeneous Velocity Models with Ray Tracing Modeling Approach
Authors: Alok Kumar Routa, Priya Ranjan Mohanty
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Complex seismic signatures are generated due to the complexity of the subsurface which is difficult to interpret. In the present study, an attempt has been made to model the complex subsurface using the Ray tracing modeling technique. Add to this, for the imaging of these geological features, Kirchhoff’s prestack depth migration is applied over the synthetic common shot gather dataset. It is found that the Kirchhoff’s migration technique in addition with the Ray tracing modeling concept has the flexibility towards the imaging of various complex geology which gives satisfactory results with proper delineation of the reflectors at their respective true depth position. The entire work has been carried out under the MATLAB environment.Keywords: Kirchhoff's migration, Prestack depth migration, Ray tracing modelling, velocity model
Procedia PDF Downloads 36513178 Modeling and Simulation of Turbulence Induced in Nozzle Cavitation and Its Effects on Internal Flow in a High Torque Low Speed Diesel Engine
Authors: Ali Javaid, Rizwan Latif, Syed Adnan Qasim, Imran Shafi
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To control combustion inside a direct injection diesel engine, fuel atomization is the best tool. Controlling combustion helps in reducing emissions and improves efficiency. Cavitation is one of the most important factors that significantly affect the nature of spray before it injects into combustion chamber. Typical fuel injector nozzles are small and operate at a very high pressure, which limits the study of internal nozzle behavior especially in case of diesel engine. Simulating cavitation in a fuel injector will help in understanding the phenomenon and will assist in further development. There is a parametric variation between high speed and high torque low speed diesel engines. The objective of this study is to simulate internal spray characteristics for a low speed high torque diesel engine. In-nozzle cavitation has strong effects on the parameters e.g. mass flow rate, fuel velocity, and momentum flux of fuel that is to be injected into the combustion chamber. The external spray dynamics and subsequently the air – fuel mixing depends on a lot of the parameters of fuel injecting the nozzle. The approach used to model turbulence induced in – nozzle cavitation for high-torque low-speed diesel engine, is homogeneous equilibrium model. The governing equations were modeled using Matlab. Complete Model in question was extensively evaluated by performing 3-D time-dependent simulations on Open FOAM, which is an open source flow solver and implemented in CFD (Computational Fluid Dynamics). Results thus obtained will be analyzed for better evaporation in the near-nozzle region. The proposed analyses will further help in better engine efficiency, low emission, and improved fuel economy.Keywords: cavitation, HEM model, nozzle flow, open foam, turbulence
Procedia PDF Downloads 29013177 The Impact of Size of the Regional Economic Blocs to the Country’s Flows of Trade: Evidence from COMESA, EAC and Tanzania
Authors: Mosses E. Lufuke, Lorna M. Kamau
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This paper attempted to assess whether the size of the regional economic bloc has an impact to the flow of trade to a particular country. Two different sized blocs (COMESA and EAC) and one country (Tanzania) have been used as the point of references. Using the results from of the analyses, the paper also was anticipated to establish whether it was rational for Tanzania to withdraw its membership from COMESA (the larger bloc) to join EAC (the small one). Gravity model has been used to estimate the relationship between the variables, from which the bilateral trade flows between Tanzania and the eighteen member countries of the two blocs (COMESA and EAC) was employed for the time between 2000 and 2013. In the model, the dummy variable for regional bloc (bloc) at which the Tanzania trade partner countries belong are also added to the model to understand which trade bloc exhibit higher trade flow with Tanzania. From the findings, it was noted that over the period of study (2000-2013) Tanzania acknowledged more than 257% of trade volume in EAC than in COMESA. Conclusive, it was noted that the flow of trade is explained by many other variables apart from the size of regional bloc; and that the size by itself offer insufficient evidence in causality relationship. The paper therefore remain neutral on such staggered switching decision since more analyses are required to establish the country’s trade flow, especially when if it had been in multiple membership of COMESA and EAC.Keywords: economic bloc, flow of trade, size of bloc, switching
Procedia PDF Downloads 24713176 The Simulation and Experimental Investigation to Study the Strain Distribution Pattern during the Closed Die Forging Process
Authors: D. B. Gohil
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Closed die forging is a very complex process, and measurement of actual forces for real material is difficult and time consuming. Hence, the modelling technique has taken the advantage of carrying out the experimentation with the proper model material which needs lesser forces and relatively low temperature. The results of experiments on the model material then may be correlated with the actual material by using the theory of similarity. There are several methods available to resolve the complexity involved in the closed die forging process. Finite Element Method (FEM) and Finite Difference Method (FDM) are relatively difficult as compared to the slab method. The slab method is very popular and very widely used by the people working on shop floor because it is relatively easy to apply and reasonably accurate for most of the common forging load requirement computations.Keywords: experimentation, forging, process modeling, strain distribution
Procedia PDF Downloads 20113175 Graph Similarity: Algebraic Model and Its Application to Nonuniform Signal Processing
Authors: Nileshkumar Vishnav, Aditya Tatu
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A recent approach of representing graph signals and graph filters as polynomials is useful for graph signal processing. In this approach, the adjacency matrix plays pivotal role; instead of the more common approach involving graph-Laplacian. In this work, we follow the adjacency matrix based approach and corresponding algebraic signal model. We further expand the theory and introduce the concept of similarity of two graphs. The similarity of graphs is useful in that key properties (such as filter-response, algebra related to graph) get transferred from one graph to another. We demonstrate potential applications of the relation between two similar graphs, such as nonuniform filter design, DTMF detection and signal reconstruction.Keywords: graph signal processing, algebraic signal processing, graph similarity, isospectral graphs, nonuniform signal processing
Procedia PDF Downloads 35213174 A Lightweight Pretrained Encrypted Traffic Classification Method with Squeeze-and-Excitation Block and Sharpness-Aware Optimization
Authors: Zhiyan Meng, Dan Liu, Jintao Meng
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Dependable encrypted traffic classification is crucial for improving cybersecurity and handling the growing amount of data. Large language models have shown that learning from large datasets can be effective, making pre-trained methods for encrypted traffic classification popular. However, attention-based pre-trained methods face two main issues: their large neural parameters are not suitable for low-computation environments like mobile devices and real-time applications, and they often overfit by getting stuck in local minima. To address these issues, we developed a lightweight transformer model, which reduces the computational parameters through lightweight vocabulary construction and Squeeze-and-Excitation Block. We use sharpness-aware optimization to avoid local minima during pre-training and capture temporal features with relative positional embeddings. Our approach keeps the model's classification accuracy high for downstream tasks. We conducted experiments on four datasets -USTC-TFC2016, VPN 2016, Tor 2016, and CICIOT 2022. Even with fewer than 18 million parameters, our method achieves classification results similar to methods with ten times as many parameters.Keywords: sharpness-aware optimization, encrypted traffic classification, squeeze-and-excitation block, pretrained model
Procedia PDF Downloads 3013173 The Influence of Nyerere in Integrating Ubuntu Knowledge and Social Work in Tanzania – A Literature Review
Authors: Meinrad Haule Lembuka
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Ubuntu is an African philosophy and model with the meaning of 'humanity to others' or 'care for other’s needs because of the guiding principle of interdependence’ that embraces collective and holistic efforts in development through the human face. The study uses a literature review method reflecting Julius Nyerere’s contributions in realizing Ubuntu and social work practice. Nyerere strived to restore Africa development in the lens of humanism through the values of solidarity, communal participation, compassion, care, justice etc; He later founded developmental social work through Ujamaa model, educational for self reliance and African dignity. Nyerere was against post-colonial syndromes through African socialism that envisioned values and principles of social work to provide social justice, human dignity, social change and social development. Also, he managed to serve the primary mission of the social work profession to enhance human wellbeing and help meet basic human needs of all people, with particular attention to the needs and empowerment of people who are vulnerable, oppressed, and living in poverty with African Ubuntu practice of equal distribution of resources. Nyerere further endorsed social work legal framework that embraced universal human rights: service, equality, social justice, and human dignity, Importance of human relationship, integrity and competence. Nyerere proved that Indigenous model can work with formal system like Social work profession. In 2014 the National Heritage Council of South Africa (NHC) honored him an Award of African Ubuntu champion. Nyerere strongly upheld to be an ambassador of social work through his remarkably contributions in developmental social work (Ujamaa model), social change, human dignity, equality, social unity and social justice in Africa and globe at large.Keywords: ubuntu, Indiginious knowledge, Indiginious social work, ubuntu social work
Procedia PDF Downloads 10313172 Analysis of the Evolution of Landscape Spatial Patterns in Banan District, Chongqing, China
Authors: Wenyang Wan
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The study of urban land use and landscape pattern is the current hotspot in the fields of planning and design, ecology, etc., which is of great significance for the construction of the overall humanistic ecosystem of the city and optimization of the urban spatial structure. Banan District, as the main part of the eastern eco-city planning of Chongqing Municipality, is a high ground for highlighting the ecological characteristics of Chongqing, realizing effective transformation of ecological value, and promoting the integrated development of urban and rural areas. The analytical methods of land use transfer matrix (GIS) and landscape pattern index (Fragstats) were used to study the characteristics and laws of the evolution of land use landscape pattern in Banan District from 2000 to 2020, which provide some reference value for Banan District to alleviate the ecological contradiction of landscape. The results of the study show that ① Banan District is rich in land use types, of which the area of cultivated land will still account for 57.15% of the total area of the landscape until 2020, accounting for an absolute advantage in land use structure of Banan District; ② From 2000 to 2020, land use conversion in Banan District is characterized as Cropland > woodland > grassland > shrubland > built-up land > water bodies > wetlands, with cropland converted to built-up land being the largest; ③ From 2000 to 2020, the landscape elements of Banan District were distributed in a balanced way, and the landscape types were rich and diversified, but due to the influence of human interference, it also presented the characteristics that the shape of the landscape elements tended to be irregular, and the dominant patches were distributed in a scattered manner, and the patches had poor connectivity. It is recommended that in future regional ecological construction, the layout should be rationally optimized, the relationship between landscape components should be coordinated, the connectivity between landscape patches should be strengthened, and the degree of landscape fragmentation should be reduced.Keywords: land use transfer, landscape pattern evolution, GIS and Fragstats, Banan district
Procedia PDF Downloads 7213171 Multi-Model Super Ensemble Based Advanced Approaches for Monsoon Rainfall Prediction
Authors: Swati Bhomia, C. M. Kishtawal, Neeru Jaiswal
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Traditionally, monsoon forecasts have encountered many difficulties that stem from numerous issues such as lack of adequate upper air observations, mesoscale nature of convection, proper resolution, radiative interactions, planetary boundary layer physics, mesoscale air-sea fluxes, representation of orography, etc. Uncertainties in any of these areas lead to large systematic errors. Global circulation models (GCMs), which are developed independently at different institutes, each of which carries somewhat different representation of the above processes, can be combined to reduce the collective local biases in space, time, and for different variables from different models. This is the basic concept behind the multi-model superensemble and comprises of a training and a forecast phase. The training phase learns from the recent past performances of models and is used to determine statistical weights from a least square minimization via a simple multiple regression. These weights are then used in the forecast phase. The superensemble forecasts carry the highest skill compared to simple ensemble mean, bias corrected ensemble mean and the best model out of the participating member models. This approach is a powerful post-processing method for the estimation of weather forecast parameters reducing the direct model output errors. Although it can be applied successfully to the continuous parameters like temperature, humidity, wind speed, mean sea level pressure etc., in this paper, this approach is applied to rainfall, a parameter quite difficult to handle with standard post-processing methods, due to its high temporal and spatial variability. The present study aims at the development of advanced superensemble schemes comprising of 1-5 day daily precipitation forecasts from five state-of-the-art global circulation models (GCMs), i.e., European Centre for Medium Range Weather Forecasts (Europe), National Center for Environmental Prediction (USA), China Meteorological Administration (China), Canadian Meteorological Centre (Canada) and U.K. Meteorological Office (U.K.) obtained from THORPEX Interactive Grand Global Ensemble (TIGGE), which is one of the most complete data set available. The novel approaches include the dynamical model selection approach in which the selection of the superior models from the participating member models at each grid and for each forecast step in the training period is carried out. Multi-model superensemble based on the training using similar conditions is also discussed in the present study, which is based on the assumption that training with the similar type of conditions may provide the better forecasts in spite of the sequential training which is being used in the conventional multi-model ensemble (MME) approaches. Further, a variety of methods that incorporate a 'neighborhood' around each grid point which is available in literature to allow for spatial error or uncertainty, have also been experimented with the above mentioned approaches. The comparison of these schemes with respect to the observations verifies that the newly developed approaches provide more unified and skillful prediction of the summer monsoon (viz. June to September) rainfall compared to the conventional multi-model approach and the member models.Keywords: multi-model superensemble, dynamical model selection, similarity criteria, neighborhood technique, rainfall prediction
Procedia PDF Downloads 13913170 A Multi-Output Network with U-Net Enhanced Class Activation Map and Robust Classification Performance for Medical Imaging Analysis
Authors: Jaiden Xuan Schraut, Leon Liu, Yiqiao Yin
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Computer vision in medical diagnosis has achieved a high level of success in diagnosing diseases with high accuracy. However, conventional classifiers that produce an image to-label result provides insufficient information for medical professionals to judge and raise concerns over the trust and reliability of a model with results that cannot be explained. In order to gain local insight into cancerous regions, separate tasks such as imaging segmentation need to be implemented to aid the doctors in treating patients, which doubles the training time and costs which renders the diagnosis system inefficient and difficult to be accepted by the public. To tackle this issue and drive AI-first medical solutions further, this paper proposes a multi-output network that follows a U-Net architecture for image segmentation output and features an additional convolutional neural networks (CNN) module for auxiliary classification output. Class activation maps are a method of providing insight into a convolutional neural network’s feature maps that leads to its classification but in the case of lung diseases, the region of interest is enhanced by U-net-assisted Class Activation Map (CAM) visualization. Therefore, our proposed model combines image segmentation models and classifiers to crop out only the lung region of a chest X-ray’s class activation map to provide a visualization that improves the explainability and is able to generate classification results simultaneously which builds trust for AI-led diagnosis systems. The proposed U-Net model achieves 97.61% accuracy and a dice coefficient of 0.97 on testing data from the COVID-QU-Ex Dataset which includes both diseased and healthy lungs.Keywords: multi-output network model, U-net, class activation map, image classification, medical imaging analysis
Procedia PDF Downloads 20213169 Multi-Layer Multi-Feature Background Subtraction Using Codebook Model Framework
Authors: Yun-Tao Zhang, Jong-Yeop Bae, Whoi-Yul Kim
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Background modeling and subtraction in video analysis has been widely proved to be an effective method for moving objects detection in many computer vision applications. Over the past years, a large number of approaches have been developed to tackle different types of challenges in this field. However, the dynamic background and illumination variations are two of the most frequently occurring issues in the practical situation. This paper presents a new two-layer model based on codebook algorithm incorporated with local binary pattern (LBP) texture measure, targeted for handling dynamic background and illumination variation problems. More specifically, the first layer is designed by block-based codebook combining with LBP histogram and mean values of RGB color channels. Because of the invariance of the LBP features with respect to monotonic gray-scale changes, this layer can produce block-wise detection results with considerable tolerance of illumination variations. The pixel-based codebook is employed to reinforce the precision from the outputs of the first layer which is to eliminate false positives further. As a result, the proposed approach can greatly promote the accuracy under the circumstances of dynamic background and illumination changes. Experimental results on several popular background subtraction datasets demonstrate a very competitive performance compared to previous models.Keywords: background subtraction, codebook model, local binary pattern, dynamic background, illumination change
Procedia PDF Downloads 21713168 A Perspective on Emergency Care of Gunshot Injuries in Northern Taiwan
Authors: Liong-Rung Liu, Yu-Hui Chiu, Wen-Han Chang
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Firearm injuries are high-energy injuries. The ballistic pathways could cause severe burns or chemical damages to vessels, musculoskeletal or other major organs. The high mortality rate is accompanied by complications such as sepsis. As laws prohibit gun possession, civilian gunshot wounds (GSW) are relatively rare in Taiwan. Our hospital, Mackay Memorial Hospital, located at the center of Taipei city is surrounded by nightclubs and red-light districts. Due to this unique location, our hospital becomes the first-line trauma center managing gunshot victims in Taiwan. To author’s best knowledge, there are few published research articles regarding this unique situation. We hereby analyze the distinct characteristics and length of stay (LOS) of GSW patients in the emergency room (ER) at Mackay Memorial Hospital. A 6-year retrospective analysis of 27 patients treated for GSW injuries from January 2012 to December 2017 was performed. The patients’ records were reviewed for the following analyses, 1) wound position and the correlated clinical presentations; 2) the LOS in ED of patients receiving emergency surgery for major organ or vascular injuries. We found males (96.3%) were injured by guns more often than females (3.7%) in all age groups. The most common injured site was in the extremities. With regards to the ER LOS, the average time were 72.2 ± 34.5 minutes for patients with triage I and 207.4 ± 143.9 minutes for patients with triage II. The ED LOS of patients whose ISS score were more than 15 was 59.9 ± 25.6 minutes, and 179.4 ± 119.8 minutes for patients whose ISS score were between 9 to 15, respectively. Among these 27 patients, 10 patients had emergency surgery and their average ED stay time was 104.5 ± 33.3 minutes. Even more, the average ED stay time could be shortened to 88.8 ± 32.3 minutes in the 5 patients with trauma team activation. In conclusion, trauma team activation in severe GSW patients indeed shortens the ED LOS and might initially improve the quality of patient care. This is the result of better trauma systems, including advances in care from emergency medical services and acute care surgical management.Keywords: gunshot, length of stay, trauma, mortality
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