Search results for: joint estimation
2553 The Generalized Pareto Distribution as a Model for Sequential Order Statistics
Authors: Mahdy Esmailian, Mahdi Doostparast, Ahmad Parsian
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In this article, sequential order statistics (SOS) censoring type II samples coming from the generalized Pareto distribution are considered. Maximum likelihood (ML) estimators of the unknown parameters are derived on the basis of the available multiple SOS data. Necessary conditions for existence and uniqueness of the derived ML estimates are given. Due to complexity in the proposed likelihood function, a useful re-parametrization is suggested. For illustrative purposes, a Monte Carlo simulation study is conducted and an illustrative example is analysed.Keywords: bayesian estimation, generalized pareto distribution, maximum likelihood estimation, sequential order statistics
Procedia PDF Downloads 5082552 Dynamic Analysis of Double Deck Tunnel
Authors: C. W. Kwak, I. J. Park, D. I. Jang
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The importance of cost-wise effective application and construction is getting increase due to the surge of traffic volume in the metropolitan cities. Accordingly, the necessity of the tunnel has large section becomes more critical. Double deck tunnel can be one of the most appropriate solutions to the necessity. The dynamic stability of double deck tunnel is essential against seismic load since it has large section and connection between perimeter lining and interim slab. In this study, 3-dimensional dynamic numerical analysis was conducted based on the Finite Difference Method to investigate the seismic behavior of double deck tunnel. Seismic joint for dynamic stability and the mitigation of seismic impact on the lining was considered in the modeling and analysis. Consequently, the mitigation of acceleration, lining displacement and stress were verified successfully.Keywords: double deck tunnel, interim slab, 3-dimensional dynamic numerical analysis, seismic joint
Procedia PDF Downloads 3792551 Sustainable Management Practices of International Construction Joint Ventures: A Conceptual Model for Managing Barriers and Risks
Authors: Mershack O. Tetteh, Albert P. C. Chan, Amos Darko, Gabriel Nani
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International construction joint ventures (ICJVs) have evolved as an effective approach to sustainable development, given their myriad socio-economic and environmental benefits. Yet, they are not free of barriers and risks. In many studies, it is termed as risks for convenience’s sake. While the barriers and risks continue to affect the success of ICJVs, a systematic and reliable approach for managing them has yet to be developed. This study aims to identify and classify the barriers and risks factors affecting ICJVs through a systematic literature review. Based on a critical review of 54 papers published in peer-reviewed journals from 1990 to 2019, a conceptual framework was proposed for managing the barriers and risks in ICJV operations. The review showed that the barriers can be grouped into six including inter-organizational differences, lack of expertise and confidence, lack of effective planning and strategies, lack of knowledge of ICJV’s fundamentals, conflicts among ICJV entities, and management difficulties. The risks were also categorized into six: policy and political risks, legal risks, financial risks, management risks, project and technical risks, and market risks. The developed model would help practitioners achieve more efficient resource allocation and bring new perspectives for managerial practices in ICJVs. Moreover, it is positioned to alleviate the negligence of previous studies that combined the barriers and risks factors as one checklist.Keywords: barriers, construction, international construction joint venture, risks, sustainable development
Procedia PDF Downloads 2582550 Construction Unit Rate Factor Modelling Using Neural Networks
Authors: Balimu Mwiya, Mundia Muya, Chabota Kaliba, Peter Mukalula
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Factors affecting construction unit cost vary depending on a country’s political, economic, social and technological inclinations. Factors affecting construction costs have been studied from various perspectives. Analysis of cost factors requires an appreciation of a country’s practices. Identified cost factors provide an indication of a country’s construction economic strata. The purpose of this paper is to identify the essential factors that affect unit cost estimation and their breakdown using artificial neural networks. Twenty-five (25) identified cost factors in road construction were subjected to a questionnaire survey and employing SPSS factor analysis the factors were reduced to eight. The 8 factors were analysed using the neural network (NN) to determine the proportionate breakdown of the cost factors in a given construction unit rate. NN predicted that political environment accounted 44% of the unit rate followed by contractor capacity at 22% and financial delays, project feasibility, overhead and profit each at 11%. Project location, material availability and corruption perception index had minimal impact on the unit cost from the training data provided. Quantified cost factors can be incorporated in unit cost estimation models (UCEM) to produce more accurate estimates. This can create improvements in the cost estimation of infrastructure projects and establish a benchmark standard to assist the process of alignment of work practises and training of new staff, permitting the on-going development of best practises in cost estimation to become more effective.Keywords: construction cost factors, neural networks, roadworks, Zambian construction industry
Procedia PDF Downloads 3612549 Robust Heart Rate Estimation from Multiple Cardiovascular and Non-Cardiovascular Physiological Signals Using Signal Quality Indices and Kalman Filter
Authors: Shalini Rankawat, Mansi Rankawat, Rahul Dubey, Mazad Zaveri
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Physiological signals such as electrocardiogram (ECG) and arterial blood pressure (ABP) in the intensive care unit (ICU) are often seriously corrupted by noise, artifacts, and missing data, which lead to errors in the estimation of heart rate (HR) and incidences of false alarm from ICU monitors. Clinical support in ICU requires most reliable heart rate estimation. Cardiac activity, because of its relatively high electrical energy, may introduce artifacts in Electroencephalogram (EEG), Electrooculogram (EOG), and Electromyogram (EMG) recordings. This paper presents a robust heart rate estimation method by detection of R-peaks of ECG artifacts in EEG, EMG & EOG signals, using energy-based function and a novel Signal Quality Index (SQI) assessment technique. SQIs of physiological signals (EEG, EMG, & EOG) were obtained by correlation of nonlinear energy operator (teager energy) of these signals with either ECG or ABP signal. HR is estimated from ECG, ABP, EEG, EMG, and EOG signals from separate Kalman filter based upon individual SQIs. Data fusion of each HR estimate was then performed by weighing each estimate by the Kalman filters’ SQI modified innovations. The fused signal HR estimate is more accurate and robust than any of the individual HR estimate. This method was evaluated on MIMIC II data base of PhysioNet from bedside monitors of ICU patients. The method provides an accurate HR estimate even in the presence of noise and artifacts.Keywords: ECG, ABP, EEG, EMG, EOG, ECG artifacts, Teager-Kaiser energy, heart rate, signal quality index, Kalman filter, data fusion
Procedia PDF Downloads 6932548 Extended Kalman Filter Based Direct Torque Control of Permanent Magnet Synchronous Motor
Authors: Liang Qin, Hanan M. D. Habbi
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A robust sensorless speed for permanent magnet synchronous motor (PMSM) has been presented for estimation of stator flux components and rotor speed based on The Extended Kalman Filter (EKF). The model of PMSM and its EKF models are modeled in Matlab /Sirnulink environment. The proposed EKF speed estimation method is also proved insensitive to the PMSM parameter variations. Simulation results demonstrate a good performance and robustness.Keywords: DTC, Extended Kalman Filter (EKF), PMSM, sensorless control, anti-windup PI
Procedia PDF Downloads 6632547 Optimal Policies in a Two-Level Supply Chain with Defective Product and Price Dependent Demand
Authors: Samira Mohabbatdar, Abbas Ahmadi, Mohsen S. Sajadieh
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This paper deals with a two-level supply chain consisted of one manufacturer and one retailer for single-type product. The demand function of the customers depends on price. We consider an integrated production inventory system where the manufacturer processes raw materials in order to deliver finished product with imperfect quality to the retailer. Then retailer inspects the products and after that delivers perfect products to customers. The proposed model is based on the joint total profit of both the manufacturer and the retailer, and it determines the optimal ordering lot-size, number of shipment and selling price of the retailer. A numerical example is provided to analyse and illustrate the behaviour and application of the model. Finally, sensitivity analysis of the key parameters are presented to test feasibility of the model.Keywords: supply chain, pricing policy, defective quality, joint economic lot sizing
Procedia PDF Downloads 3352546 DOA Estimation Using Golden Section Search
Authors: Niharika Verma, Sandeep Santosh
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DOA technique is a localization technique used in the communication field. Various algorithms have been developed for direction of arrival estimation like MUSIC, ROOT MUSIC, etc. These algorithms depend on various parameters like antenna array elements, number of snapshots and various others. Basically the MUSIC spectrum is evaluated and peaks obtained are considered as the angle of arrivals. The angles evaluated using this process depends on the scanning interval chosen. The accuracy of the results obtained depends on the coarseness of the interval chosen. In this paper, golden section search is applied to the MUSIC algorithm and therefore, more accurate results are achieved. Initially the coarse DOA estimations is done using the MUSIC algorithm in the range -90 to 90 degree at the interval of 10 degree. After the peaks obtained then fine DOA estimation is done using golden section search. Also, the partitioning method is applied to estimate the number of signals incident on the antenna array. Dependency of the algorithm on the number of snapshots is also being explained. Hence, the accurate results are being determined using this algorithm.Keywords: Direction of Arrival (DOA), golden section search, MUSIC, number of snapshots
Procedia PDF Downloads 4452545 Exponentiated Transmuted Weibull Distribution: A Generalization of the Weibull Probability Distribution
Authors: Abd El Hady N. Ebraheim
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This paper introduces a new generalization of the two parameter Weibull distribution. To this end, the quadratic rank transmutation map has been used. This new distribution is named exponentiated transmuted Weibull (ETW) distribution. The ETW distribution has the advantage of being capable of modeling various shapes of aging and failure criteria. Furthermore, eleven lifetime distributions such as the Weibull, exponentiated Weibull, Rayleigh and exponential distributions, among others follow as special cases. The properties of the new model are discussed and the maximum likelihood estimation is used to estimate the parameters. Explicit expressions are derived for the quantiles. The moments of the distribution are derived, and the order statistics are examined.Keywords: exponentiated, inversion method, maximum likelihood estimation, transmutation map
Procedia PDF Downloads 5642544 Comparison of Statistical Methods for Estimating Missing Precipitation Data in the River Subbasin Lenguazaque, Colombia
Authors: Miguel Cañon, Darwin Mena, Ivan Cabeza
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In this work was compared and evaluated the applicability of statistical methods for the estimation of missing precipitations data in the basin of the river Lenguazaque located in the departments of Cundinamarca and Boyacá, Colombia. The methods used were the method of simple linear regression, distance rate, local averages, mean rates, correlation with nearly stations and multiple regression method. The analysis used to determine the effectiveness of the methods is performed by using three statistical tools, the correlation coefficient (r2), standard error of estimation and the test of agreement of Bland and Altmant. The analysis was performed using real rainfall values removed randomly in each of the seasons and then estimated using the methodologies mentioned to complete the missing data values. So it was determined that the methods with the highest performance and accuracy in the estimation of data according to conditions that were counted are the method of multiple regressions with three nearby stations and a random application scheme supported in the precipitation behavior of related data sets.Keywords: statistical comparison, precipitation data, river subbasin, Bland and Altmant
Procedia PDF Downloads 4662543 Age Estimation from Teeth among North Indian Population: Comparison and Reliability of Qualitative and Quantitative Methods
Authors: Jasbir Arora, Indu Talwar, Daisy Sahni, Vidya Rattan
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Introduction: Age estimation is a crucial step to build the identity of a person, both in case of deceased and alive. In adults, age can be estimated on the basis of six regressive (Attrition, Secondary dentine, Dentine transparency, Root resorption, Cementum apposition and Periodontal Disease) changes in teeth qualitatively using scoring system and quantitatively by micrometric method. The present research was designed to establish the reliability of qualitative (method 1) and quantitative (method 2) of age estimation among North Indians and to compare the efficacy of these two methods. Method: 250 single-rooted extracted teeth (18-75 yrs.) were collected from Department of Oral Health Sciences, PGIMER, Chandigarh. Before extraction, periodontal score of each tooth was noted. Labiolingual sections were prepared and examined under light microscope for regressive changes. Each parameter was scored using Gustafson’s 0-3 point score system (qualitative), and total score was calculated. For quantitative method, each regressive change was measured quantitatively in form of 18 micrometric parameters under microscope with the help of measuring eyepiece. Age was estimated using linear and multiple regression analysis in Gustafson’s method and Kedici’s method respectively. Estimated age was compared with actual age on the basis of absolute mean error. Results: In pooled data, by Gustafson’s method, significant correlation (r= 0.8) was observed between total score and actual age. Total score generated an absolute mean error of ±7.8 years. Whereas, for Kedici’s method, a value of correlation coefficient of r=0.5 (p<0.01) was observed between all the eighteen micrometric parameters and known age. Using multiple regression equation, age was estimated, and an absolute mean error of age was found to be ±12.18 years. Conclusion: Gustafson’s (qualitative) method was found to be a better predictor for age estimation among North Indians.Keywords: forensic odontology, age estimation, North India, teeth
Procedia PDF Downloads 2412542 Median-Based Nonparametric Estimation of Returns in Mean-Downside Risk Portfolio Frontier
Authors: H. Ben Salah, A. Gannoun, C. de Peretti, A. Trabelsi
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The Downside Risk (DSR) model for portfolio optimisation allows to overcome the drawbacks of the classical mean-variance model concerning the asymetry of returns and the risk perception of investors. This model optimization deals with a positive definite matrix that is endogenous with respect to portfolio weights. This aspect makes the problem far more difficult to handle. For this purpose, Athayde (2001) developped a new recurcive minimization procedure that ensures the convergence to the solution. However, when a finite number of observations is available, the portfolio frontier presents an appearance which is not very smooth. In order to overcome that, Athayde (2003) proposed a mean kernel estimation of the returns, so as to create a smoother portfolio frontier. This technique provides an effect similar to the case in which we had continuous observations. In this paper, taking advantage on the the robustness of the median, we replace the mean estimator in Athayde's model by a nonparametric median estimator of the returns. Then, we give a new version of the former algorithm (of Athayde (2001, 2003)). We eventually analyse the properties of this improved portfolio frontier and apply this new method on real examples.Keywords: Downside Risk, Kernel Method, Median, Nonparametric Estimation, Semivariance
Procedia PDF Downloads 4922541 Specific Biomarker Level and Function Outcome Changes in Treatment of Patients with Frozen Shoulder Using Dextrose Prolotherapy Injection
Authors: Nuralam Sam, Irawan Yusuf, Irfan Idris, Endi Adnan
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The most case in the shoulder in the the adult is the frozen shoulder. It make an uncomfortable sensation which disturbance daily activity. The studies of frozen shoulder are still limited. This study used a true experimental pre and post test design with a group design. The participant underwent dextrose prolotherapy injection in the rotator cuff, intraarticular glenohumeral joint, long head tendon biceps, and acromioclavicular joint injections with 15% dextrose, respectively, at week 2, week 4, and week 6. Participants were followed for 12 weeks. The specific biomarker MMP and TIMP, ROM, DASH score were measured at baseline, at week 6, and week 12. The data were analyzed by multivariate analysis (repeated measurement ANOVA, Paired T-Test, and Wilcoxon) to determine the effect of the intervention. The result showed a significant decrease in The Disability of the Arm, Shoulder, and Hand (DASH) score in prolo injection patients in each measurement week (p < 0.05). While the measurement of Range of Motion (ROM), each direction of shoulder motion showed a significant difference in average each week, from week 0 to week 6 (p <0.05).Dextrose prolotherapy injection results give a significant improvement in functional outcome of the shoulder joint, and ROMand did not show significant results in assessing the specific biomarker, MMP-1, and TIMP-1 in tissue repair. This study suggestion an alternative to the use of injection prolotherapy in Frozen shoulder patients, which has fewer side effects and better effectiveness than the use of corticosteroid injections.Keywords: frozen shoulder, ROM, DASH score, prolotherapy, MMP-1, TIMP-1
Procedia PDF Downloads 1092540 Understanding Human Rights Violations in the Fight against Boko Haram: A Historical Perspective
Authors: Anthony Mpiani
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Recent media and NGO reports suggest that human rights violations have been a salient characteristic of the government Joint Task Force (JTF) in the war on Boko Haram. However, there has been relatively scant scholarly engagement with the forms of abuses committed by the JTF against civilians and why such human rights violations occur. The focus of this paper is to analyse the various human rights violations committed by JTF in the war against Boko Haram. Employing a historical approach, it argues that the JTF's human rights violations is shaped by the philosophy of colonial policing in Nigeria. Consequently, the failure of successive post-colonial governments to ideologically transform policing is accountable for the human rights abuses being witnessed in Nigeria today. A philosophical transformation in Nigeria's security forces especially the police and military is a prerequisite for ending human rights abuses in the fight against Boko Haram.Keywords: colonialism, policing, joint task force, counterinsurgency, Boko Haram, human rights violations
Procedia PDF Downloads 1622539 Ratio Type Estimators for the Estimation of Population Coefficient of Variation under Two-Stage Sampling
Authors: Muhammad Jabbar
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In this paper we propose two ratio and ratio type exponential estimator for the estimation of population coefficient of variation using the auxiliary information under two-stage sampling. The properties of these estimators are derived up to first order of approximation. The efficiency conditions under which suggested estimator are more efficient, are obtained. Numerical and simulated studies are conducted to support the superiority of the estimators. Theoretically and numerically, we have found that our proposed estimator is always more efficient as compared to its competitor estimator.Keywords: two-stage sampling, coefficient of variation, ratio type exponential estimator
Procedia PDF Downloads 5262538 The Evaluation of the Performance of Different Filtering Approaches in Tracking Problem and the Effect of Noise Variance
Authors: Mohammad Javad Mollakazemi, Farhad Asadi, Aref Ghafouri
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Performance of different filtering approaches depends on modeling of dynamical system and algorithm structure. For modeling and smoothing the data the evaluation of posterior distribution in different filtering approach should be chosen carefully. In this paper different filtering approaches like filter KALMAN, EKF, UKF, EKS and smoother RTS is simulated in some trajectory tracking of path and accuracy and limitation of these approaches are explained. Then probability of model with different filters is compered and finally the effect of the noise variance to estimation is described with simulations results.Keywords: Gaussian approximation, Kalman smoother, parameter estimation, noise variance
Procedia PDF Downloads 4372537 Genetic Algorithm and Multi Criteria Decision Making Approach for Compressive Sensing Based Direction of Arrival Estimation
Authors: Ekin Nurbaş
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One of the essential challenges in array signal processing, which has drawn enormous research interest over the past several decades, is estimating the direction of arrival (DOA) of plane waves impinging on an array of sensors. In recent years, the Compressive Sensing based DoA estimation methods have been proposed by researchers, and it has been discovered that the Compressive Sensing (CS)-based algorithms achieved significant performances for DoA estimation even in scenarios where there are multiple coherent sources. On the other hand, the Genetic Algorithm, which is a method that provides a solution strategy inspired by natural selection, has been used in sparse representation problems in recent years and provides significant improvements in performance. With all of those in consideration, in this paper, a method that combines the Genetic Algorithm (GA) and the Multi-Criteria Decision Making (MCDM) approaches for Direction of Arrival (DoA) estimation in the Compressive Sensing (CS) framework is proposed. In this method, we generate a multi-objective optimization problem by splitting the norm minimization and reconstruction loss minimization parts of the Compressive Sensing algorithm. With the help of the Genetic Algorithm, multiple non-dominated solutions are achieved for the defined multi-objective optimization problem. Among the pareto-frontier solutions, the final solution is obtained with the multiple MCDM methods. Moreover, the performance of the proposed method is compared with the CS-based methods in the literature.Keywords: genetic algorithm, direction of arrival esitmation, multi criteria decision making, compressive sensing
Procedia PDF Downloads 1442536 Joint Replenishment and Heterogeneous Vehicle Routing Problem with Cyclical Schedule
Authors: Ming-Jong Yao, Chin-Sum Shui, Chih-Han Wang
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This paper is developed based on a real-world decision scenario that an industrial gas company that applies the Vendor Managed Inventory model and supplies liquid oxygen with a self-operated heterogeneous vehicle fleet to hospitals in nearby cities. We name it as a Joint Replenishment and Heterogeneous Vehicle Routing Problem with Cyclical Schedule and formulate it as a non-linear mixed-integer linear programming problem which simultaneously determines the length of the planning cycle (PC), the length of the replenishment cycle and the dates of replenishment for each customer and the vehicle routes of each day within PC, such that the average daily operation cost within PC, including inventory holding cost, setup cost, transportation cost, and overtime labor cost, is minimized. A solution method based on genetic algorithm, embedded with an encoding and decoding mechanism and local search operators, is then proposed, and the hash function is adopted to avoid repetitive fitness evaluation for identical solutions. Numerical experiments demonstrate that the proposed solution method can effectively solve the problem under different lengths of PC and number of customers. The method is also shown to be effective in determining whether the company should expand the storage capacity of a customer whose demand increases. Sensitivity analysis of the vehicle fleet composition shows that deploying a mixed fleet can reduce the daily operating cost.Keywords: cyclic inventory routing problem, joint replenishment, heterogeneous vehicle, genetic algorithm
Procedia PDF Downloads 862535 Redundancy Component Matrix and Structural Robustness
Authors: Xinjian Kou, Linlin Li, Yongju Zhou, Jimian Song
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We introduce the redundancy matrix that expresses clearly the geometrical/topological configuration of the structure. With the matrix, the redundancy of the structure is resolved into redundant components and assigned to each member or rigid joint. The values of the diagonal elements in the matrix indicates the importance of the corresponding members or rigid joints, and the geometrically correlations can be shown with the non-diagonal elements. If a member or rigid joint failures, reassignment of the redundant components can be calculated with the recursive method given in the paper. By combining the indexes of reliability and redundancy components, we define an index concerning the structural robustness. To further explain the properties of the redundancy matrix, we cited several examples of statically indeterminate structures, including two trusses and a rigid frame. With the examples, some simple results and the properties of the matrix are discussed. The examples also illustrate that the redundancy matrix and the relevant concepts are valuable in structural safety analysis.Keywords: Structural Robustness, Structural Reliability, Redundancy Component, Redundancy Matrix
Procedia PDF Downloads 2692534 Basic Characteristics and Prospects of Synchronized Stir Welding
Authors: Shoji Matsumoto
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Friction Stir Welding (FSW) has been widely used in the automotive, aerospace, and high-tech industries due to its superior mechanical properties after welding. However, when it becomes a matter to perform a high-quality joint using FSW, it is necessary to secure an advanced tilt angle (usually 1 to 5 degrees) using a dedicated FSW machine and to use a joint structure and a restraining jig that can withstand the tool pressure applied during the jointing process using a highly rigid processing machine. One issue that has become a challenge in this process is ‘productivity and versatility’. To solve this problem, we have conducted research and development of multi-functioning machines and robotics with FSW tools, which combine cutting/milling and FSW functions as one in recent years. However, the narrow process window makes it prone to welding defects and lacks repeatability, which makes a limitation for FSW its use in the fields where precisions required. Another reason why FSW machines are not widely used in the world is because of the matter of very high cost of ownership.Keywords: synchronized, stir, welding, friction, traveling speed, synchronized stir welding, friction stir welding
Procedia PDF Downloads 502533 Urban Big Data: An Experimental Approach to Building-Value Estimation Using Web-Based Data
Authors: Sun-Young Jang, Sung-Ah Kim, Dongyoun Shin
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Current real-estate value estimation, difficult for laymen, usually is performed by specialists. This paper presents an automated estimation process based on big data and machine-learning technology that calculates influences of building conditions on real-estate price measurement. The present study analyzed actual building sales sample data for Nonhyeon-dong, Gangnam-gu, Seoul, Korea, measuring the major influencing factors among the various building conditions. Further to that analysis, a prediction model was established and applied using RapidMiner Studio, a graphical user interface (GUI)-based tool for derivation of machine-learning prototypes. The prediction model is formulated by reference to previous examples. When new examples are applied, it analyses and predicts accordingly. The analysis process discerns the crucial factors effecting price increases by calculation of weighted values. The model was verified, and its accuracy determined, by comparing its predicted values with actual price increases.Keywords: apartment complex, big data, life-cycle building value analysis, machine learning
Procedia PDF Downloads 3702532 Bayesian Estimation under Different Loss Functions Using Gamma Prior for the Case of Exponential Distribution
Authors: Md. Rashidul Hasan, Atikur Rahman Baizid
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The Bayesian estimation approach is a non-classical estimation technique in statistical inference and is very useful in real world situation. The aim of this paper is to study the Bayes estimators of the parameter of exponential distribution under different loss functions and then compared among them as well as with the classical estimator named maximum likelihood estimator (MLE). In our real life, we always try to minimize the loss and we also want to gather some prior information (distribution) about the problem to solve it accurately. Here the gamma prior is used as the prior distribution of exponential distribution for finding the Bayes estimator. In our study, we also used different symmetric and asymmetric loss functions such as squared error loss function, quadratic loss function, modified linear exponential (MLINEX) loss function and non-linear exponential (NLINEX) loss function. Finally, mean square error (MSE) of the estimators are obtained and then presented graphically.Keywords: Bayes estimator, maximum likelihood estimator (MLE), modified linear exponential (MLINEX) loss function, Squared Error (SE) loss function, non-linear exponential (NLINEX) loss function
Procedia PDF Downloads 3812531 Improvement of Direct Torque and Flux Control of Dual Stator Induction Motor Drive Using Intelligent Techniques
Authors: Kouzi Katia
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This paper proposes a Direct Torque Control (DTC) algorithm of dual Stator Induction Motor (DSIM) drive using two approach intelligent techniques: Artificial Neural Network (ANN) approach replaces the switching table selector block of conventional DTC and Mamdani Fuzzy Logic controller (FLC) is used for stator resistance estimation. The fuzzy estimation method is based on an online stator resistance correction through the variations of stator current estimation error and its variation. The fuzzy logic controller gives the future stator resistance increment at the output. The main advantage of suggested algorithm control is to reduce the hardware complexity of conventional selectors, to avoid the drive instability that may occur in certain situation and ensure the tracking of the actual of the stator resistance. The effectiveness of the technique and the improvement of the whole system performance are proved by results.Keywords: artificial neural network, direct torque control, dual stator induction motor, fuzzy logic estimator, switching table
Procedia PDF Downloads 3402530 Pilot-free Image Transmission System of Joint Source Channel Based on Multi-Level Semantic Information
Authors: Linyu Wang, Liguo Qiao, Jianhong Xiang, Hao Xu
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In semantic communication, the existing joint Source Channel coding (JSCC) wireless communication system without pilot has unstable transmission performance and can not effectively capture the global information and location information of images. In this paper, a pilot-free image transmission system of joint source channel based on multi-level semantic information (Multi-level JSCC) is proposed. The transmitter of the system is composed of two networks. The feature extraction network is used to extract the high-level semantic features of the image, compress the information transmitted by the image, and improve the bandwidth utilization. Feature retention network is used to preserve low-level semantic features and image details to improve communication quality. The receiver also is composed of two networks. The received high-level semantic features are fused with the low-level semantic features after feature enhancement network in the same dimension, and then the image dimension is restored through feature recovery network, and the image location information is effectively used for image reconstruction. This paper verifies that the proposed multi-level JSCC algorithm can effectively transmit and recover image information in both AWGN channel and Rayleigh fading channel, and the peak signal-to-noise ratio (PSNR) is improved by 1~2dB compared with other algorithms under the same simulation conditions.Keywords: deep learning, JSCC, pilot-free picture transmission, multilevel semantic information, robustness
Procedia PDF Downloads 1202529 Preparation and Biological Evaluation of 186/188Re-Chitosan for Radiosynovectomy
Authors: N. Ahmadi, H. Yousefnia, A. Bahrami-Samani
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Chitosan is a natural and biodegradable polysaccharide with special characteristic for application in intracavital therapy. 166Ho-chitosan has been reported for the treatment of hepatocellular carcinoma and RSV with promising results. The aim of this study was to prepare 186/188Re-chitosan for radiosynovectomy purposes and investigate the probability of its leakage from the knee joint. 186/188Re was produced by neutron irradiation of the natural rhenium in a research reactor. Chemical processing was performed to obtain (186/188Re)-NaReO4- according to the IAEA manual. A stock solution of chitosan was prepared by dissolving in 1 % acetic acid aqueous solution (10 mg/mL). 1.5 mL of this stock solution was added to the vial containing the activity and the mixture was stirred for 5 min in the room temperature. The radiochemical purity of the complex was checked by the ITLC method, showing the purity of higher than 98%. Distribution of the radiolabeled complex was determined after intra-articular injection into the knees of rats. Excellent retention was observed in the joint with approximately no activity in the other organs.Keywords: chitosan, leakage, radiosynovectomy, rhenium
Procedia PDF Downloads 3392528 A Study on the False Alarm Rates of MEWMA and MCUSUM Control Charts When the Parameters Are Estimated
Authors: Umar Farouk Abbas, Danjuma Mustapha, Hamisu Idi
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It is now a known fact that quality is an important issue in manufacturing industries. A control chart is an integrated and powerful tool in statistical process control (SPC). The mean µ and standard deviation σ parameters are estimated. In general, the multivariate exponentially weighted moving average (MEWMA) and multivariate cumulative sum (MCUSUM) are used in the detection of small shifts in joint monitoring of several correlated variables; the charts used information from past data which makes them sensitive to small shifts. The aim of the paper is to compare the performance of Shewhart xbar, MEWMA, and MCUSUM control charts in terms of their false rates when parameters are estimated with autocorrelation. A simulation was conducted in R software to generate the average run length (ARL) values of each of the charts. After the analysis, the results show that a comparison of the false alarm rates of the charts shows that MEWMA chart has lower false alarm rates than the MCUSUM chart at various levels of parameter estimated to the number of ARL0 (in control) values. Also noticed was that the sample size has an advert effect on the false alarm of the control charts.Keywords: average run length, MCUSUM chart, MEWMA chart, false alarm rate, parameter estimation, simulation
Procedia PDF Downloads 2202527 Robustified Asymmetric Logistic Regression Model for Global Fish Stock Assessment
Authors: Osamu Komori, Shinto Eguchi, Hiroshi Okamura, Momoko Ichinokawa
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The long time-series data on population assessments are essential for global ecosystem assessment because the temporal change of biomass in such a database reflects the status of global ecosystem properly. However, the available assessment data usually have limited sample sizes and the ratio of populations with low abundance of biomass (collapsed) to those with high abundance (non-collapsed) is highly imbalanced. To allow for the imbalance and uncertainty involved in the ecological data, we propose a binary regression model with mixed effects for inferring ecosystem status through an asymmetric logistic model. In the estimation equation, we observe that the weights for the non-collapsed populations are relatively reduced, which in turn puts more importance on the small number of observations of collapsed populations. Moreover, we extend the asymmetric logistic regression model using propensity score to allow for the sample biases observed in the labeled and unlabeled datasets. It robustified the estimation procedure and improved the model fitting.Keywords: double robust estimation, ecological binary data, mixed effect logistic regression model, propensity score
Procedia PDF Downloads 2642526 Osteoarthritis (OA): A Total Knee Replacement Surgery
Authors: Loveneet Kaur
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Introduction: Osteoarthritis (OA) is one of the leading causes of disability, and the knee is the most commonly affected joint in the body. The last resort for treatment of knee OA is Total Knee Replacement (TKR) surgery. Despite numerous advances in prosthetic design, patients do not reach normal function after surgery. Current surgical decisions are made on 2D radiographs and patient interviews. Aims: The aim of this study was to compare knee kinematics pre and post-TKR surgery using computer-animated images of patient-specific models under everyday conditions. Methods: 7 subjects were recruited for the study. Subjects underwent 3D gait analysis during 4 everyday activities and medical imaging of the knee joint pre- and one-month post-surgery. A 3D model was created from each of the scans, and the kinematic gait analysis data was used to animate the images. Results: Improvements were seen in a range of motion in all 4 activities 1-year post-surgery. The preoperative 3D images provide detailed information on the anatomy of the osteoarthritic knee. The postoperative images demonstrate potential future problems associated with the implant. Although not accurate enough to be of clinical use, the animated data can provide valuable insight into what conditions cause damage to both the osteoarthritic and prosthetic knee joints. As the animated data does not require specialist training to view, the images can be utilized across the fields of health professionals and manufacturing in the assessment and treatment of patients pre and post-knee replacement surgery. Future improvements in the collection and processing of data may yield clinically useful data. Conclusion: Although not yet of clinical use, the potential application of 3D animations of the knee joint pre and post-surgery is widespread.Keywords: Orthoporosis, Ortharthritis, knee replacement, TKR
Procedia PDF Downloads 452525 Carbohydrate Intake Estimation in Type I Diabetic Patients Described by UVA/Padova Model
Authors: David A. Padilla, Rodolfo Villamizar
Abstract:
In recent years, closed loop control strategies have been developed in order to establish a healthy glucose profile in type 1 diabetic mellitus (T1DM) patients. However, the controller itself is unable to define a suitable reference trajectory for glucose. In this paper, a control strategy Is proposed where the shape of the reference trajectory is generated bases in the amount of carbohydrates present during the digestive process, due to the effect of carbohydrate intake. Since there no exists a sensor to measure the amount of carbohydrates consumed, an estimator is proposed. Thus this paper presents the entire process of designing a carbohydrate estimator, which allows estimate disturbance for a predictive controller (MPC) in a T1MD patient, the estimation will be used to establish a profile of reference and improve the response of the controller by providing the estimated information of ingested carbohydrates. The dynamics of the diabetic model used are due to the equations described by the UVA/Padova model of the T1DMS simulator, the system was developed and simulated in Simulink, taking into account the noise and limitations of the glucose control system actuators.Keywords: estimation, glucose control, predictive controller, MPC, UVA/Padova
Procedia PDF Downloads 2602524 Estimation of Missing Values in Aggregate Level Spatial Data
Authors: Amitha Puranik, V. S. Binu, Seena Biju
Abstract:
Missing data is a common problem in spatial analysis especially at the aggregate level. Missing can either occur in covariate or in response variable or in both in a given location. Many missing data techniques are available to estimate the missing data values but not all of these methods can be applied on spatial data since the data are autocorrelated. Hence there is a need to develop a method that estimates the missing values in both response variable and covariates in spatial data by taking account of the spatial autocorrelation. The present study aims to develop a model to estimate the missing data points at the aggregate level in spatial data by accounting for (a) Spatial autocorrelation of the response variable (b) Spatial autocorrelation of covariates and (c) Correlation between covariates and the response variable. Estimating the missing values of spatial data requires a model that explicitly account for the spatial autocorrelation. The proposed model not only accounts for spatial autocorrelation but also utilizes the correlation that exists between covariates, within covariates and between a response variable and covariates. The precise estimation of the missing data points in spatial data will result in an increased precision of the estimated effects of independent variables on the response variable in spatial regression analysis.Keywords: spatial regression, missing data estimation, spatial autocorrelation, simulation analysis
Procedia PDF Downloads 380