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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Practical Web-scale Recommender Systems / 実用的なWebスケール推薦システム / # ja-Kana

Tagami, Yukihiro 25 September 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第21390号 / 情博第676号 / 新制||情||117(附属図書館) / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 鹿島 久嗣, 教授 山本 章博, 教授 下平 英寿 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM
82

Classification of Dense Masses in Mammograms

Naram, Hari Prasad 01 May 2018 (has links) (PDF)
This dissertation material provided in this work details the techniques that are developed to aid in the Classification of tumors, non-tumors, and dense masses in a Mammogram, certain characteristics such as texture in a mammographic image are used to identify the regions of interest as a part of classification. Pattern recognizing techniques such as nearest mean classifier and Support vector machine classifier are also used to classify the features. The initial stages include the processing of mammographic image to extract the relevant features that would be necessary for classification and during the final stage the features are classified using the pattern recognizing techniques mentioned above. The goal of this research work is to provide the Medical Experts and Researchers an effective method which would aid them in identifying the tumors, non-tumors, and dense masses in a mammogram. At first the breast region extraction is carried using the entire mammogram. The extraction is carried out by creating the masks and using those masks to extract the region of interest pertaining to the tumor. A chain code is employed to extract the various regions, the extracted regions could potentially be classified as tumors, non-tumors, and dense regions. Adaptive histogram equalization technique is employed to enhance the contrast of an image. After applying the adaptive histogram equalization for several times which will provide a saturated image which would contain only bright spots of the mammographic image which appear like dense regions of the mammogram. These dense masses could be potential tumors which would need treatment. Relevant Characteristics such as texture in the mammographic image are used for feature extraction by using the nearest mean and support vector machine classifier. A total of thirteen Haralick features are used to classify the three classes. Support vector machine classifier is used to classify two class problems and radial basis function (RBF) kernel is used to find the best possible (c and gamma) values. Results obtained in this research suggest the best classification accuracy was achieved by using the support vector machines for both Tumor vs Non-Tumor and Tumor vs Dense masses. The maximum accuracies achieved for the tumor and non-tumor is above 90 % and for the dense masses is 70.8% using 11 features for support vector machines. Support vector machines performed better than the nearest mean majority classifier in the classification of the classes. Various case studies were performed using two distinct datasets in which each dataset consisting of 24 patients’ data in two individual views. Each patient data will consist of both the cranio caudal view and medio lateral oblique views. From these views the region of interest which could possibly be a tumor, non-tumor, or a dense regions(mass).
83

Maskininlärning som medel för att betygsätta samtal med språklärande syfte mellan robot och människa / Machine learning as tool to grade language learning conversations between robot and human

Melander, Gustav, Wänlund, Robin January 2019 (has links)
Det svenska företaget Furhat Robotics har skapat en robot kallad Furhat vilken är kapabel till att interagera med människor i språkcafé-liknande miljöer. Syftet med den robotledda konversationen är att utveckla deltagarnas språkkunskaper, vilka efter varje konversation får svara på en enkät om vad de tyckte om samtalet med Furhat. Ur detta har frågan huruvida det är möjligt att förutspå vad deltagarna tyckte om samtalet baserat på konversationens struktur uppstått. Syftet med denna rapport är att analysera huruvida det är möjligt att kvantifiera konversationerna och förutspå svaren i enkäten med hjälp av maskininlärning. Det dataset som rapporten baserar sig på erhölls från tidigare studier i Kollaborativ Robotassisterad Språkinlärning (Collaborative Robot Assisted Language Learning). Resultaten visade på ett RMSE högre än variansen för medelvärdet av enkätsvaren vilket indikerar att den framtagna modellen inte är särskilt effektiv. Modellen presterade dock bättre i vissa förutsägelser då varje enskilt enkätsvar förutspåddes var för sig. Detta antyder att modellen skulle kunna användas till vissa frågeformuleringar / The Swedish company Furhat Robotic have created a robot called Furhat, which is able to interact with humans in a language café setting. The purpose of the robot led conversation is for the participants to develop their language skills. After the conversation the humans will answer a survey about what they thought about the conversation with Furhat. A question that has arisen from this is if it is possible to predict the survey answers based on just the conversation. The purpose of this paper is to analyze if it is possible to quantify the conversations linked to the survey answers, and by doing so be able to predict the answers in new conversations with a machine learning approach. The data set being used was obtained from an earlier study in Collaborative Robot Assisted Language Learning. The result returned a RMSE that was greater than the variance of the average conversation score which indicates that the model is not very effective. However, it excelled in some predictions trying to give scores to each separate survey answer, indicating that the model could be used for certain question formulations.
84

A GENE ONTOLOGY BASED COMPUTATIONAL APPROACH FOR THE PREDICTION OF PROTEIN FUNCTIONS

Kharsikar, Saket 13 September 2007 (has links)
No description available.
85

A Direct Algorithm for the K-Nearest-Neighbor Classifier via Local Warping of the Distance Metric

Neo, TohKoon 30 November 2007 (has links) (PDF)
The k-nearest neighbor (k-NN) pattern classifier is a simple yet effective learner. However, it has a few drawbacks, one of which is the large model size. There are a number of algorithms that are able to condense the model size of the k-NN classifier at the expense of accuracy. Boosting is therefore desirable for increasing the accuracy of these condensed models. Unfortunately, there does not exist a boosting algorithm that works well with k-NN directly. We present a direct boosting algorithm for the k-NN classifier that creates an ensemble of models with locally modified distance weighting. An empirical study conducted on 10 standard databases from the UCI repository shows that this new Boosted k-NN algorithm has increased generalization accuracy in the majority of the datasets and never performs worse than standard k-NN.
86

Generating Exploration Mission-3 Trajectories to a 9:2 NRHO Using Machine Learning

Guzman, Esteban 01 December 2018 (has links) (PDF)
The purpose of this thesis is to design a machine learning algorithm platform that provides expanded knowledge of mission availability through a launch season by improving trajectory resolution and introducing launch mission forecasting. The specific scenario addressed in this paper is one in which data is provided for four deterministic translational maneuvers through a mission to a Near Rectilinear Halo Orbit (NRHO) with a 9:2 synodic frequency. Current launch availability knowledge under NASA’s Orion Orbit Performance Team is established by altering optimization variables associated to given reference launch epochs. This current method can be an abstract task and relies on an orbit analyst to structure a mission based off an established mission design methodology associated to the performance of Orion and NASA's Space Launch System. Introducing a machine learning algorithm trained to construct mission scenarios within the feasible range of known trajectories reduces the required interaction of the orbit analyst by removing the needed step of optimizing the orbit to fit an expected translational response required of the spacecraft. In this study, k-Nearest Neighbor and Bayesian Linear Regression successfully predicted classical orbital elements for the launch windows observed. However both algorithms had limitations due to their approaches to model fitting. Training machine learning algorithms off of classical orbital elements introduced a repetitive approach to reconstructing mission segments for different arrival opportunities through the launch window and can prove to be a viable method of launch window scan generation for future missions.
87

Uncertainty Analysis : Severe Accident Scenario at a Nordic Nuclear Power Plant

Hedly, Josefin, De Young, Mikaela January 2023 (has links)
Nuclear Power Plants (NPP) undergo fault and sensitivity analysis with scenario modelling to predict catastrophic events, specifically releases of Cesium 137 (Cs-137). The purpose of this thesis is to find which of 108 input-features from Modular Accident Analysis Program (MAAP)simulation code are important, when there is large release of Cs-137 emissions. The features are tested all together and in their groupings. To find important features, the Machine learning (ML) model Random Forest (RF) has a built-in attribute which identifies important features. The results of RF model classification are corroborated with Support Vector Machines (SVM), K-Nearest Neighbor (KNN) and use k-folds cross validation to improve and validate the results, resulting in a near 90% accuracy for the three ML models. RF is successful at identifying important features related to Cs-137 emissions, by using the classification model to first identify top features, to further train the models at identifying important input-features. The discovered input-features are important both within their individual groups, but also when including all features simultaneously. The large number of features included did not disrupt RF much, but the skewed dataset with few classified extreme events caused the accuracy to be lower at near 90%.
88

The effect of FORTIFIED home designation on property value

Gould, Leslie 07 August 2020 (has links)
Due to the serious impact wind damage has on homes in the Gulf Coast region, policy makers, community developers, and homeowners are seeking ways to lessen impacts. One potential tool to increase properties’ resiliency in the event of a periodic and catastrophic event is wind mitigation, the process of adding features to a building, i.e. a house, to increase the strength of the structure amid a storm such as a hurricane. In this research, I evaluate the tiers of FORTIFIED homes as the mitigation strategies. I use Zillow ZTRAX and Institute of Business and Home Safety data to estimate how each level of FORTIFIED home designation affects property value. The results show FORTIFIED Gold designation on a new home has a 0%-8.4% increase on property value. I place my finding into a BCA of FORTIFIED designation to evaluate how this one benefit fits into the greater picture.
89

Hierarchical Statistical Models for Large Spatial Data in Uncertainty Quantification and Data Fusion

Shi, Hongxiang January 2017 (has links)
No description available.
90

NEAREST NEIGHBOR SEARCH IN DISTRIBUTED DATABASES

KUMAR, SUSMIT 11 June 2002 (has links)
No description available.

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