350 research outputs found

    A novel statistical based feature extraction approach for the inner-class feature estimation using linear regression

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    International audienceNowadays, statistical based feature extraction approaches are commonly used in the knowledge discovery field with Machine Learning. These features are accurate and give relevant information of the samples; however, these approaches consider some assumptions, such as the membership of the signals or samples to specific statistical distributions. In this work, we propose to model statistical computation through Linear Regression (LR) models; these models will be divided by classes, in order to increase the inner-class identification likelihood. In general, an ensemble of LR models will estimate a targeted statistical feature. In an online deployment, the pool of LR models of a given targeted statistical feature will be evaluated to find the most similar value to the current input, which will be as the estimated of the feature. The proposal is tested with a real world application in traffic network classification. In this case study, fast classification response has to be provided, and statistical based features are widely used for this aim. In this sense, the statistical features must give early signs about the status of the network in order to achieve some objectives such as improve the quality of service or detect malicious traffic

    PASCAL: A Learning-aided Cooperative Bandwidth Control Policy for Hierarchical Storage Systems

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    Nowadays, the Hierarchical Storage System (HSS) is considered as an ideal model to meet the cost-performance demand. The data migration between storing tiers of HSS is the way to achieve the cost-performance goal. The bandwidth control is to limit the maximum amount of data migration. Most of previous research about HSS focus on studying the data migration policy instead of bandwidth control. However, the recent research about cache and networking optimization suggest that the bandwidth control has significant impact on the system performance. Few previous work achieves a satisfactory bandwidth control in HSS since it is hard to control bandwidth for so many data migration tasks simultaneously. In this paper, we first give a stochastic programming model to formalize the bandwidth control problem in HSS. Then we propose a learning-aided bandwidth control policy for HSS, named \Pascal{}, which learns to control the bandwidth of different data migration task in an cooperative way. We implement \Pascal{} on a commercial HSS and compare it with three strong baselines over a group of workloads. Our evaluation on the physical system shows that \Pascal{} can effectively decrease 1.95X the tail latency and greatly improve throughput stability (2X ↓\downarrow throughput jitter), and meanwhile keep the throughput at a relatively high level

    Estimated Profits of Rengginang Lorjuk Madura by Used Comparison of Holt-Winter and Moving Average

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    Rengginang Lorjuk is a typical Madura food that is ordered more by SMEs and is found in Sumenep Regency and several other areas in Madura. This product is made for supplies and orders, where demand will surge at certain times. Therefore, SMEs of Rengginang Lorjuk is required to have good planning in determining the selling price in accordance with the revenue target obtained. Considering that the main raw materials used are sticky rice and ensis leei (lorjuk) are raw materials that have fluctuating prices, this studio compares forecasting methods namely Holt Winter (HW) and Moving Average (MA), supported by MSE and MAPE, in order to obtain accurate forecasting results. These forecasting results show that HW has better accuracy than the MA, which is then used to calculate the cost of production with an Activity-Based Costing system, which requires charging costs for all activities carried out in production, namely the cost of raw materials, direct labor costs, and overhead factory fee. Using MAPE values, this study yields 4 estimates of production costs in accordance with changes in raw material costs

    DEVELOPMENT OF A REAL-TIME SMARTWATCH ALGORITHM FOR THE DETECTION OF GENERALIZED TONIC-CLONIC SEIZURES

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    Generalized Tonic Clonic Seizure (GTCS) detection has been an ongoing problem in the healthcare industry. Algorithms and devices for this problem do exist on the market, but they either have poor False Positive Rates, are expensive, or cannot be used as anything other than a seizure detector. There is currently a need to provide a portable seizure detection algorithm that can meets patient demands. In this thesis, we develop a two-stage end-to-end seizure detection algorithm that is implemented on an Apple Watch, and validated on Epilepsy Monitoring Unit (EMU) patients. 124 features are extracted from the collected dataset, after which 9 are empirically selected. We have provided mutual information based feature selection methods that cannot yet be implemented on the watch due to computational restrictions. In stage one we compare common anomaly detection methods of One Class SVM, SVDD, Isolation Forest and Extended Isolation Forest over a thorough cross-validation to determine which is ideal to use as an anomaly detector. Isolation Forest (Sensitivity: 0.9, FPR: 3.4/day, Latency: 69s) was chosen despite the good sensitivity and latency of SVDD (Sensitivity: 1.0, FPR: 17.28/day, Latency: 8.9s) due to better implementation characteristics. During in-vivo testing, we record a sensitivity of 100% over 24 recorded tonic seizures with FPR: 1.29/day. To further limit false positive detections, a second stage is incorporated to separate between true and false positives using deep learning methods. We compare a Deep-LSTM, CNN-LSTM and TCN network. CNN-LSTM (Sensitivity: 0.93, FPR: 0.047/day) was finally used on the watch due to its tractable implementation, though TCN (Sensitivity: 1.0, FPR: 0/day) performed significantly better during cross-validation. During in-vivo testing, the 2-stage algorithm showed sensitivity: 100%, FPR: 0.05/day over 2004 tracked hours and 12 seizures. The mean latency was 62 seconds, which is on the threshold of clinical acceptability for this task

    Context Exploitation in Data Fusion

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    Complex and dynamic environments constitute a challenge for existing tracking algorithms. For this reason, modern solutions are trying to utilize any available information which could help to constrain, improve or explain the measurements. So called Context Information (CI) is understood as information that surrounds an element of interest, whose knowledge may help understanding the (estimated) situation and also in reacting to that situation. However, context discovery and exploitation are still largely unexplored research topics. Until now, the context has been extensively exploited as a parameter in system and measurement models which led to the development of numerous approaches for the linear or non-linear constrained estimation and target tracking. More specifically, the spatial or static context is the most common source of the ambient information, i.e. features, utilized for recursive enhancement of the state variables either in the prediction or the measurement update of the filters. In the case of multiple model estimators, context can not only be related to the state but also to a certain mode of the filter. Common practice for multiple model scenarios is to represent states and context as a joint distribution of Gaussian mixtures. These approaches are commonly referred as the join tracking and classification. Alternatively, the usefulness of context was also demonstrated in aiding the measurement data association. Process of formulating a hypothesis, which assigns a particular measurement to the track, is traditionally governed by the empirical knowledge of the noise characteristics of sensors and operating environment, i.e. probability of detection, false alarm, clutter noise, which can be further enhanced by conditioning on context. We believe that interactions between the environment and the object could be classified into actions, activities and intents, and formed into structured graphs with contextual links translated into arcs. By learning the environment model we will be able to make prediction on the target\u2019s future actions based on its past observation. Probability of target future action could be utilized in the fusion process to adjust tracker confidence on measurements. By incorporating contextual knowledge of the environment, in the form of a likelihood function, in the filter measurement update step, we have been able to reduce uncertainties of the tracking solution and improve the consistency of the track. The promising results demonstrate that the fusion of CI brings a significant performance improvement in comparison to the regular tracking approaches

    Novel deep cross-domain framework for fault diagnosis or rotary machinery in prognostics and health management

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    Improving the reliability of engineered systems is a crucial problem in many applications in various engineering fields, such as aerospace, nuclear energy, and water declination industries. This requires efficient and effective system health monitoring methods, including processing and analyzing massive machinery data to detect anomalies and performing diagnosis and prognosis. In recent years, deep learning has been a fast-growing field and has shown promising results for Prognostics and Health Management (PHM) in interpreting condition monitoring signals such as vibration, acoustic emission, and pressure due to its capacity to mine complex representations from raw data. This doctoral research provides a systematic review of state-of-the-art deep learning-based PHM frameworks, an empirical analysis on bearing fault diagnosis benchmarks, and a novel multi-source domain adaptation framework. It emphasizes the most recent trends within the field and presents the benefits and potentials of state-of-the-art deep neural networks for system health management. Besides, the limitations and challenges of the existing technologies are discussed, which leads to opportunities for future research. The empirical study of the benchmarks highlights the evaluation results of the existing models on bearing fault diagnosis benchmark datasets in terms of various performance metrics such as accuracy and training time. The result of the study is very important for comparing or testing new models. A novel multi-source domain adaptation framework for fault diagnosis of rotary machinery is also proposed, which aligns the domains in both feature-level and task-level. The proposed framework transfers the knowledge from multiple labeled source domains into a single unlabeled target domain by reducing the feature distribution discrepancy between the target domain and each source domain. Besides, the model can be easily reduced to a single-source domain adaptation problem. Also, the model can be readily updated to unsupervised domain adaptation problems in other fields such as image classification and image segmentation. Further, the proposed model is modified with a novel conditional weighting mechanism that aligns the class-conditional probability of the domains and reduces the effect of irrelevant source domain which is a critical issue in multi-source domain adaptation algorithms. The experimental verification results show the superiority of the proposed framework over state-of-the-art multi-source domain-adaptation models

    Addressing Variability in Speech when Recognizing Emotion and Mood In-the-Wild

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    Bipolar disorder is a chronic mental illness, affecting 4% of Americans, that is characterized by periodic mood changes ranging from severe depression to extreme compulsive highs. Both mania and depression profoundly impact the behavior of affected individuals, resulting in potentially devastating personal and social consequences. Bipolar disorder is managed clinically with regular interactions with care providers, who assess mood, energy levels, and the form and content of speech. Recent work has proposed smartphones for automatically monitoring mood using speech. Much of the early work in speech-centered mood detection has been done in the laboratory or clinic and is not reflective of the variability found in real-world conversations and conditions. Outside of these settings, automatic mood detection is hard, as the recordings include environmental noise, differences in recording devices, and variations in subject speaking patterns. Without addressing these issues, it is difficult to move towards a passive mobile health system. My research works to address this variability present in speech so that such a system can be created, allowing for interventions to mitigate the life-changing effects of mood transitions. However detecting mood directly from speech is difficult, as mood varies over the course of days or weeks, while speech fluctuates rapidly. To address this, my thesis explores how an intermediate step can be used to aid in this prediction. For example, one of the major symptoms of bipolar disorder is emotion dysregulation - changes in the way emotions are perceived and a lack of inhibition in their expression. My work has supported the relationship between automatically extracted emotion estimates and mood. Because of this, my thesis explores how to mitigate the variability found when detecting emotion from speech. The remainder of my thesis is focused on employing these emotion-based features, as well as features based on language content, to real-world applications. This dissertation is divided into the following parts: Part I: I address the direct classification of mood from speech. This is accomplished by addressing variability due to recording device using preprocessing and multi-task learning. I then show how both subject-specific and population-general information can be combined to significantly improve mood detection. Part II: I explore the automatic detection of emotion from speech and how to control for the other factors of variability present in the speech signal. I use progressive networks as a method to augment emotion with other paralinguistic data including gender and speaker, as well as other datasets. Additionally, I introduce a novel domain generalization method for cross-corpus detection. Part III: I demonstrate real-world applications of speech mood monitoring using everyday conversations. I show how the previously introduced generalized model can predict emotion from the speech of individuals with suicidal ideation, demonstrating its effectiveness across domains. Furthermore, I use these predictions to distinguish individuals with suicidal thoughts from healthy controls. Lastly, I introduce a novel framework for intervention detection in individuals with bipolar disorder. I then create a natural speech mood monitoring system based on features derived from measures of emotion and automatic speech recognition (ASR) transcripts and show effective intervention detection. I conclude this dissertation with the following future directions: (1) Extending my emotion generalization system to include multiple modalities and factors of variability; (2) Expanding natural speech mood monitoring by including more devices, exploring other data besides speech, and investigating mood rating causality.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/153461/1/gideonjn_1.pd
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