3,228 research outputs found
Dasymetric mapping using UAV high resolution 3D data within urban areas
UID/SOC/04647/2019Multi-temporal analysis of census small-area microdata is hampered by the fact that census tract shapes do not often coincide between census exercises. Dasymetric mapping techniques provide a workaround that is nonetheless highly dependent on the quality of ancillary data. The objectives of this work are to: (1) Compare the use of three spatial techniques for the estimation of population according to census tracts: Areal interpolation and dasymetric mapping using control data-building block area (2D) and volume (3D); (2) demonstrate the potential of unmanned aerial vehicle (UAV) technology for the acquisition of control data; (3) perform a sensitivity analysis using Monte Carlo simulations showing the effect of changes in building block volume (3D information) in population estimates. The control data were extracted by a (semi)-automatic solution-3DEBP (3D extraction building parameters) developed using free open source software (FOSS) tools. The results highlight the relevance of 3D for the dasymetric mapping exercise, especially if the variations in height between building blocks are significant. Using low-cost UAV backed systems with a FOSS-only computing framework also proved to be a competent solution with a large scope of potential applications.publishersversionpublishe
Machine Learning and Integrative Analysis of Biomedical Big Data.
Recent developments in high-throughput technologies have accelerated the accumulation of massive amounts of omics data from multiple sources: genome, epigenome, transcriptome, proteome, metabolome, etc. Traditionally, data from each source (e.g., genome) is analyzed in isolation using statistical and machine learning (ML) methods. Integrative analysis of multi-omics and clinical data is key to new biomedical discoveries and advancements in precision medicine. However, data integration poses new computational challenges as well as exacerbates the ones associated with single-omics studies. Specialized computational approaches are required to effectively and efficiently perform integrative analysis of biomedical data acquired from diverse modalities. In this review, we discuss state-of-the-art ML-based approaches for tackling five specific computational challenges associated with integrative analysis: curse of dimensionality, data heterogeneity, missing data, class imbalance and scalability issues
Benchmarking distance-based partitioning methods for mixed-type data
Clustering mixed-type data, that is, observation by variable data that consist of both continuous and categorical variables poses novel challenges. Foremost among these challenges is the choice of the most appropriate clustering method for the data. This paper presents a benchmarking study comparing eight distance-based partitioning methods for mixed-type data in terms of cluster recovery performance. A series of simulations carried out by a full factorial design are presented that examined the effect of a variety of factors on cluster recovery. The amount of cluster overlap, the percentage of categorical variables in the data set, the number of clusters and the number of observations had the largest effects on cluster recovery and in most of the tested scenarios. KAMILA, K-Prototypes and sequential Factor Analysis and K-Means clustering typically performed better than other methods. The study can be a useful reference for practitioners in the choice of the most appropriate method
3D Point Clouds in Urban Planning: Developing and Releasing High-end Methodologies based on LiDAR and UAV Data for the Extraction of Building Parameters
Os dados geográficos têm um papel determinante na formalização do plano
urbano, enquanto instrumento de planeamento e documento normativo que define
juridicamente as obrigações públicas e vincula os particulares, num determinado
período temporal, no que respeita a disciplina urbanística de uma cidade ou de um
aglomerado urbano, estabelecendo regras de uso e de ocupação do solo. O plano está
associado a um processo, designado processo de planeamento; processo esse que e
constituído por um conjunto de fases, dinâmicas e adaptativas, que se iniciam na sua
elaboração e terminam na avaliação dos desvios entre o determinado no documento
inicial e as metas e objectivos efectivamente atingidos. O plano, o processo e a
praxis do planeamento exigem dados geográficos actualizados a cada instante, quer
para as acções de monitorização quer para os momentos de avaliação.
Um dos aspectos cruciais do plano e a quantificação da volumetria do espaço
edificado existente. Outro aspecto, também fundamental, é o da gestão dessa volumetria;
quer da volumetria existente quer da volumetria adicional. O tema da volumetria
dos espaços edificados tem constituído, aliás, um dos temas mais sensíveis
quando se trata da densificação do espaço urbano existente ou do desenho de novos
espaços urbanos de expansão. Considerando o quadro teórico apresentado, o tema
central da tese trata da modelação de nuvens de pontos 3D obtidas por tecnologia
LiDAR e por UAV, para as aplicações na elaboração do plano e no processo
de planeamento urbano, designadamente quantificação dos parâmetros urbanísticos
altura da fachada e volume dos edifícios.A exploração do tema central da tese suporta-se em dois níveis: o nível da operacionalização e o nível da usabilidade. O nível da operacionalizão concretiza dois
objectivos: i) demonstração da relevância e da pertinência da extracção, medição
e geovisualização 3D dos parâmetros urbanísticos baseadas na experimentação e
implementação de técnicas de geoprocessamento; ii) demonstração da pertinência
dos parâmetros urbanísticos extraídos considerando distintas morfologias urbanas.
Para o nível da usabilidade de nem-se igualmente dois objectivos: i) demonstração
da usabilidade dos parâmetros urbanísticos extraídos avaliando o erro associado a
extracção; ii) demonstração da usabilidade dos parâmetros urbanísticos extraídos
para planeamento, em particular para o mapeamento dasimétrico de alta precisão.
Da investigação decorre uma solução metodol ogica. A solução metodológica
nomeada 3D Extraction Building Parameters (3DEBP) destina-se a extracção da
área, da altura da fachada e do volume dos edifícios a partir de nuvens de pontos
3D. Esta solução foi criada tendo por base um conjunto de ferramentas FOSS:
PostgreSQL/PostGIS, QGIS, GRASS e R-stats.
Foram realizados testes em duas áreas urbanas com morfologias distintas:
Praia de Faro (morfologia irregular) e Amadora (morfologia regular). O teste sobre
a área urbana da Praia de Faro utilizou uma nuvem de pontos LiDAR e uma outra
extra da de levantamento realizado por UAV. O teste sobre um quarteirão urbano
de Amadora foi realizado apenas sobre nuvem de pontos UAV. Os testes revelaram
que a qualidade da informação extra da e dependente da morfologia urbana.
Nas conclusões discute-se a medição 3D com base em dados obtidos por
tecnologia LiDAR e UAV, questiona-se a implementação de soluções FOSS para
diferentes fases do processo de planeamento e defende-se a introdução intensiva da
modelação 3D no plano urbano do futuro.Geographical data plays a major role in urban plan development, both as
a planning instrument and as a normative document that legally de nes public
obligations and binds individuals, in a given period of time, regarding the urban
aspect of a city or an urban conglomerate, and establishes standards for land use and
land cover. The plan is associated with a process, called the planning process, which
consists in a set of dynamic and adaptive phases that begin with its development
and end with the evaluation of any discrepancies between the provisions of the
original document and the accomplished goals and objectives. The plan, the process,
and the planning praxis require up-to-date geographical data at all times, both for
monitoring actions and for the evaluation phases.
One of the crucial aspects of the plan is the quanti cation of the existing
building volume. Another fundamental aspect is managing that volume: both regarding
the existing volume and any additional volumes. Actually, the building
volume in built areas has been one of the most sensitive topics on the densi cation
of existing urban spaces or the design of new growing urban areas.
Considering the existing theoretical framework, the central topic of this thesis
focuses on 3D point cloud modelling obtained from LiDAR and UAV technologies,
employed in the development of a plan and in the urban planning process,
namely regarding two speci c building parameters { building height and volume.
The explanation of the central topic of this thesis is twofold: implementation and usability. The implementation level has two goals: i) demonstrating the relevance
and pertinence of the extraction, measurement, and 3D geovisualization of building
parameters based on the experimentation and implementation of geoprocessing
techniques; ii) demonstrating the pertinence of the extracted building parameters
considering di erent urban morphologies. At the usability level, we de ned two
goals: i) demonstrating the usability of the extracted building parameters, evaluating
the error associated with the extraction; ii) demonstrating the usability of these
parameters for planning, particularly for high precision dasymetric mapping.
Based on our research, we propose a methodological solution termed. 3D
Extraction Building Parameters (3DEBP) and aimed at extracting areas, fa cade
height, and building volumes from 3D point clouds. This solution was created with
the following set of FOSS tools: PostgreSQL/PostGIS, GRASS, QGIS, and R-stats.
We performed several tests in two urban areas with di erent morphologies:
Praia de Faro (irregular morphology) and Amadora (regular morphology). The
former (Praia de Faro) used a LiDAR point cloud and another one extracted from a
UAV survey, while the latter (urban neighbourhood of Amadora) only used a UAV
point cloud. Both experiments reveal that the quality of the information extracted
depends on urban morphology.
Finally, we discuss 3D measurement based on data obtained from LiDAR
and UAV technology, raising questions on the implementation of FOSS solutions for
di erent phases of the planning process, and arguing for the intensive introduction
of 3D modelling for the future of urban planning
The Faculty Notebook, September 2016
The Faculty Notebook is published periodically by the Office of the Provost at Gettysburg College to bring to the attention of the campus community accomplishments and activities of academic interest. Faculty are encouraged to submit materials for consideration for publication to the Associate Provost for Faculty Development. Copies of this publication are available at the Office of the Provost
COMAP Early Science: VIII. A Joint Stacking Analysis with eBOSS Quasars
We present a new upper limit on the cosmic molecular gas density at z = 2.4 − 3.4 obtained using the first year of observations from the CO Mapping Array Project (COMAP). COMAP data cubes are stacked on the 3D positions of 243 quasars selected from the Extended Baryon Oscillation SpectroscopicSurvey (eBOSS) catalog, yielding a 95% upper limit for flux from CO(1-0) line emission of 0.129 Jykm/s. Depending on the balance of the emission between the quasar host and its environment, this value can be interpreted as an average CO line luminosity L′CO of eBOSS quasars of ≤ 1.26 × 1011 K km pc2s−1, or an average molecular gas density ρH2 in regions of the universe containing a quasar of ≤ 1.52 × 108 M⊙ cMpc−3. The L′ CO upper limit falls among CO line luminosities obtained fromindividually-targeted quasars in the COMAP redshift range, and the ρH2 value is comparable to upper limits obtained from other Line Intensity Mapping (LIM) surveys and their joint analyses. Further, we forecast the values obtainable with the COMAP/eBOSS stack after the full 5-year COMAP Pathfinder survey. We predict that a detection is probable with this method, depending on the CO properties of the quasar sample. Based on the achieved sensitivity, we believe that this technique of stacking LIM data on the positions of traditional galaxy or quasar catalogs is extremely promising, both asa technique for investigating large galaxy catalogs efficiently at high redshift and as a technique for bolstering the sensitivity of LIM experiments, even with a fraction of their total expected survey data
A Web GIS-based Integration of 3D Digital Models with Linked Open Data for Cultural Heritage Exploration
This PhD project explores how geospatial semantic web concepts, 3D web-based visualisation, digital interactive map, and cloud computing concepts could be integrated to enhance digital cultural heritage exploration; to offer long-term archiving and dissemination of 3D digital cultural heritage models; to better interlink heterogeneous and sparse cultural heritage data.
The research findings were disseminated via four peer-reviewed journal articles and a conference article presented at GISTAM 2020 conference (which received the ‘Best Student Paper Award’)
Dynaamisten mallien puoliautomaattinen parametrisointi käyttäen laitosdataa
The aim of this thesis was to develop a new methodology for estimating parameters of NAPCON ProsDS dynamic simulator models to better represent data containing several operating points. Before this thesis, no known methodology had existed for combining operating point identification with parameter estimation of NAPCON ProsDS simulator models.
The methodology was designed by assessing and selecting suitable methods for operating space partitioning, parameter estimation and parameter scheduling. Previously implemented clustering algorithms were utilized for the operating space partition. Parameter estimation was implemented as a new tool in the NAPCON ProsDS dynamic simulator and iterative parameter estimation methods were applied. Finally, lookup tables were applied for tuning the model parameters according to the state.
The methodology was tested by tuning a heat exchanger model to several operating points based on plant process data. The results indicated that the developed methodology was able to tune the simulator model to better represent several operating states. However, more testing with different models is required to verify general applicability of the methodology.Tämän diplomityön tarkoitus oli kehittää uusi parametrien estimointimenetelmä NAPCON ProsDS -simulaattorin dynaamisille malleille, jotta ne vastaisivat paremmin dataa useista prosessitiloista. Ennen tätä diplomityötä NAPCON ProsDS -simulaattorin malleille ei ollut olemassa olevaa viritysmenetelmää, joka yhdistäisi operointitilojen tunnistuksen parametrien estimointiin.
Menetelmän kehitystä varten tutkittiin ja valittiin sopivat menetelmät operointiavaruuden jakamiselle, parametrien estimoinnille ja parametrien virittämiseen prosessitilan mukaisesti. Aikaisemmin ohjelmoituja klusterointialgoritmeja hyödynnettiin operointiavaruuden jakamisessa. Parametrien estimointi toteutettiin uutena työkaluna NAPCON ProsDS -simulaattoriin ja estimoinnissa käytettiin iteratiivisia optimointimenetelmiä. Lopulta hakutaulukoita sovellettiin mallin parametrien hienosäätöön prosessitilojen mukaisesti.
Menetelmää testattiin virittämällä lämmönvaihtimen malli kahteen eri prosessitilaan käyttäen laitokselta kerättyä prosessidataa. Tulokset osoittavat että kehitetty menetelmä pystyi virittämään simulaattorin mallin vastaamaan paremmin dataa useista prosessitiloista. Kuitenkin tarvitaan lisää testausta erityyppisten mallien kanssa, jotta voidaan varmistaa menetelmän yleinen soveltuvuus
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