Toward Next Generation of Gazetteer: Utilizing GeoSPARQL For Developing Link...Dongpo Deng
This document summarizes Dongpo Deng's presentation on developing linked geoname data using GeoSPARQL. It discusses transforming a Taiwanese place name dataset into RDF triples using a place name ontology. A linked data server and GeoSPARQL endpoint were created to serve and query the linked place name data. Spatial and temporal SPARQL queries over the data were demonstrated. The linked place names can be used as controlled vocabularies and are connected to other datasets like Geonames.org.
- Chord is a protocol and algorithm for a distributed hash table (DHT) that maps keys to nodes in a structured, decentralized peer-to-peer overlay network. It uses consistent hashing to assign keys to nodes, providing load balancing and flexibility.
- Chord nodes each maintain a finger table for efficient O(logN) lookups of keys. Periodic stabilization protocols update successor pointers and finger tables as nodes join and leave to ensure correctness and availability.
Prof Tom Trainor (University of Washington, Seattle, USA)Rene Kotze
TITLE: Two cultures in high energy nuclear physics
Since the mid eighties a community originating within the Bevalac program at the LBNL has sought to achieve formation of a color-deconfined quark-gluon plasma in heavy ion (A-A) collisions using successively higher collision energies at the AGS, SPS, RHIC and now the LHC, emphasizing a flowing dense "partonic" medium as the principal phenomenon. During much of the same period the high energy physics (HEP) community studying elementary collisions (e-e, e-p, p-p) developed the modern theory of QCD, emphasizing dijet production (fragmentation of scattered partons to observable hadrons) as the principal (calculable) phenomenon. Initially it was assumed that the QGP phenomenon in most-central A-A collisions might be distinguished from the HEP dijet phenomenon in elementary collisions. However, strong overlaps in phenomenology have revealed significant conflicts between QGP and HEP "cultures," especially at RHIC and LHC energies. In this talk I review some of the history and contrast an assortment of experimental evidence and interpretations from the two cultures with suggested conflict resolution.
Statistical issues in global fits: Lessons from PDF determinationsJuan Rojo
The document discusses statistical issues that arise in global fits to determine parton distribution functions (PDFs) from experimental data. It notes that PDF fits must combine data from different collision types and experiments, which can have inconsistent measurements. Traditional PDF fitting methods make restrictive assumptions that introduce bias, while the NNPDF approach uses neural networks and Monte Carlo replicas to avoid biases and faithfully represent uncertainties, including in regions with limited data. Inconsistent data poses challenges and requires delicate handling in global fits to obtain statistically sound PDF results.
Quality Assurance in LOINC® using Description LogicTomasz Adamusiak
When multiple LOINC parts map to the same SNOMED CT concept, it indicates that those LOINC parts are semantically equivalent according to SNOMED CT. Even though they are represented separately in LOINC, SNOMED CT provides the integration by grouping them under a single concept. This enriches the representation and allows for more complete reasoning and quality assurance across terminologies.
Colored petri nets theory and applicationsAbu Hussein
This document discusses colored Petri nets (CP-nets) and their applications. CP-nets combine Petri nets with programming languages to model systems involving concurrency, communication, and resource sharing. They allow for simulation and formal verification. The document provides examples of CP-net applications in various domains including protocols, software, hardware, control systems, and military systems. It also describes how CP-net models can be used to automatically generate code for system implementations.
The impact of new collider data into the NNPDF global analysisJuan Rojo
The document summarizes Juan Rojo's presentation on the impact of new collider data in the NNPDF global analysis. It discusses updates and improvements to the NNPDF methodology, including adopting the public code APFEL, adding new LHC datasets like LHCb and top quark pair differential distributions, and analyzing the impact on parton distributions from including precise Tevatron and LHC Z boson data. Preliminary results from NNPDF3.1 indicate good stability compared to the previous NNPDF3.0 analysis, with reduced uncertainties and improved flavor separation from new experimental inputs.
Toward Next Generation of Gazetteer: Utilizing GeoSPARQL For Developing Link...Dongpo Deng
This document summarizes Dongpo Deng's presentation on developing linked geoname data using GeoSPARQL. It discusses transforming a Taiwanese place name dataset into RDF triples using a place name ontology. A linked data server and GeoSPARQL endpoint were created to serve and query the linked place name data. Spatial and temporal SPARQL queries over the data were demonstrated. The linked place names can be used as controlled vocabularies and are connected to other datasets like Geonames.org.
- Chord is a protocol and algorithm for a distributed hash table (DHT) that maps keys to nodes in a structured, decentralized peer-to-peer overlay network. It uses consistent hashing to assign keys to nodes, providing load balancing and flexibility.
- Chord nodes each maintain a finger table for efficient O(logN) lookups of keys. Periodic stabilization protocols update successor pointers and finger tables as nodes join and leave to ensure correctness and availability.
Prof Tom Trainor (University of Washington, Seattle, USA)Rene Kotze
TITLE: Two cultures in high energy nuclear physics
Since the mid eighties a community originating within the Bevalac program at the LBNL has sought to achieve formation of a color-deconfined quark-gluon plasma in heavy ion (A-A) collisions using successively higher collision energies at the AGS, SPS, RHIC and now the LHC, emphasizing a flowing dense "partonic" medium as the principal phenomenon. During much of the same period the high energy physics (HEP) community studying elementary collisions (e-e, e-p, p-p) developed the modern theory of QCD, emphasizing dijet production (fragmentation of scattered partons to observable hadrons) as the principal (calculable) phenomenon. Initially it was assumed that the QGP phenomenon in most-central A-A collisions might be distinguished from the HEP dijet phenomenon in elementary collisions. However, strong overlaps in phenomenology have revealed significant conflicts between QGP and HEP "cultures," especially at RHIC and LHC energies. In this talk I review some of the history and contrast an assortment of experimental evidence and interpretations from the two cultures with suggested conflict resolution.
Statistical issues in global fits: Lessons from PDF determinationsJuan Rojo
The document discusses statistical issues that arise in global fits to determine parton distribution functions (PDFs) from experimental data. It notes that PDF fits must combine data from different collision types and experiments, which can have inconsistent measurements. Traditional PDF fitting methods make restrictive assumptions that introduce bias, while the NNPDF approach uses neural networks and Monte Carlo replicas to avoid biases and faithfully represent uncertainties, including in regions with limited data. Inconsistent data poses challenges and requires delicate handling in global fits to obtain statistically sound PDF results.
Quality Assurance in LOINC® using Description LogicTomasz Adamusiak
When multiple LOINC parts map to the same SNOMED CT concept, it indicates that those LOINC parts are semantically equivalent according to SNOMED CT. Even though they are represented separately in LOINC, SNOMED CT provides the integration by grouping them under a single concept. This enriches the representation and allows for more complete reasoning and quality assurance across terminologies.
Colored petri nets theory and applicationsAbu Hussein
This document discusses colored Petri nets (CP-nets) and their applications. CP-nets combine Petri nets with programming languages to model systems involving concurrency, communication, and resource sharing. They allow for simulation and formal verification. The document provides examples of CP-net applications in various domains including protocols, software, hardware, control systems, and military systems. It also describes how CP-net models can be used to automatically generate code for system implementations.
The impact of new collider data into the NNPDF global analysisJuan Rojo
The document summarizes Juan Rojo's presentation on the impact of new collider data in the NNPDF global analysis. It discusses updates and improvements to the NNPDF methodology, including adopting the public code APFEL, adding new LHC datasets like LHCb and top quark pair differential distributions, and analyzing the impact on parton distributions from including precise Tevatron and LHC Z boson data. Preliminary results from NNPDF3.1 indicate good stability compared to the previous NNPDF3.0 analysis, with reduced uncertainties and improved flavor separation from new experimental inputs.
This document discusses correlations between the Standard Penetration Test (SPT) and Cone Penetration Test (CPT). It notes that while SPT is widely used, CPT provides more reliable and repeatable results. The document reviews research on expressing the relationship between SPT N-values and CPT cone resistance (qc) through ratios of qc/N. It presents Robertson and Campanella's method which uses the relationship (qc/pa)/N60 to determine soil behavior type from CPT and SPT data. While this is a simple method, it can cause confusion at boundary zones between soil types. Developing a CPT-SPT correlation provides additional geotechnical data based on the more common
Principal component analysis (PCA) was used to analyze the conformational diversity of Ras proteins based on X-ray crystal structures. PCA separated the structures into two main clusters corresponding to the GTP-bound and GDP-bound conformations, capturing over 57.4% of the variance in the first two principal components. PCA loading plots identified displacements of switch regions as dominant features describing the conformational differences.
PCA was also used to analyze interactions between ligands and protein structures of CYP3A4 based on molecular interaction fields calculated using grid probes. Consensus PCA separated the structures based on differences in interactions with hydrophobic probes. PCA score plots distinguished the homology model from crystal structures based on interactions with Phe304, Thr309 and
Parameterized Model Checking of Rendezvous SystemsFrancesco Spegni
A standard technique for solving the parameterized model
checking problem is to reduce it to the classic model checking problem of finitely many finite-state systems. This work considers some of the theoretical power and limitations of this technique. We focus on concurrent systems in which processes communicate via pairwise rendezvous, as well as the special cases of disjunctive guards and token passing; specifications are expressed in indexed temporal logic without the next operator; and the underlying network topologies are generated by suitable
Monadic Second Order Logic formulas and graph operations. First, we settle the exact computational complexity of the parameterized model checking problem for some of our concurrent systems, and establish new
decidability results for others. Second, we consider the cases that model checking the parameterized system can be reduced to model checking some fixed number of processes, the number is known as a cutoff. We
provide many cases for when such cutoffs can be computed, establish lower bounds on the size of such cutoffs, and identify cases where no cutoff exists. Third, we consider cases for which the parameterized system
is equivalent to a single finite-state system (more precisely a Buchi word automaton), and establish tight bounds on the sizes of such automata.
This document summarizes research using laser speckle contrast imaging (LSCI) to study pulsatile blood flow dynamics in cerebral vasculature. LSCI allows non-invasive monitoring of cerebral blood flow with high temporal resolution. The research aims to quantify differences in pulsatile flow between arteries and veins and investigate neurovascular coupling. Preliminary results show LSCI can record at sample rates up to 9,072 frames per second and detect a 13ms difference in rise time between arterial and venous blood flow pulses. Further studies could separate arteries and veins, record hemodynamics after neural stimulation, and integrate LSCI with other imaging modalities.
An overview of the Phonopy (and Phono3py) lattice-dynamics codes, covering features, examples, applications and troubleshooting (2014 presentation updated for 2015).
Attentive semantic alignment with offset aware correlation kernelsNAVER Engineering
Semantic correspondence is the problem of establishing correspondences across images depicting different instances of the same object or scene class. One of recent approaches to this problem is to estimate parameters of a global transformation model that densely aligns one image to the other. Since an entire correlation map between all feature pairs across images is typically used to predict such a global transformation, noisy features from different backgrounds, clutter, and occlusion distract the predictor from correct estimation of the alignment. This is a challenging issue, in particular, in the problem of semantic correspondence where a large degree of image variations is often involved. In this paper, we introduce an attentive semantic alignment method that focuses on reliable correlations, filtering out distractors. For effective attention, we also propose an offset-aware correlation kernel that learns to capture translation-invariant local transformations in computing correlation values over spatial locations. Experiments demonstrate the effectiveness of the attentive model and offset-aware kernel, and the proposed model combining both techniques achieves the state-of-the-art performance.
The document presents Distributed Context Petri Nets (DCoPNs) for modeling context-dependent behavior in adaptive systems. DCoPNs extend Context Petri Nets with context dependency relations and runtime consistency checks. A mobile city guide example illustrates how DCoPNs capture context adaptations and ensure consistent interactions between contexts. The approach was validated in modeling and analyzing self-adaptive systems using Context Petri Nets.
Talk presented at the 2019 Context-oriented programming workshop colocated with ECOOP in london.
This work presents an extension to Context petri nets (CoPN) to enable the communication between different nodes, each defined using a CoPN. This extension demonstrates the interaction with different context dependency relations in face of unannounced connection and disconnection of nodes.
This study used computational methods to identify peptide inhibitors of the interaction between the death receptor DR6 and the N-terminal fragment of amyloid precursor protein (NAPP), which is implicated in Alzheimer's disease (AD). A focused peptide library was virtually screened and peptides were docked and scored against the NAPP binding site. Several tetrapeptides were predicted to bind strongly to NAPP, particularly Pro-Lys-Trp-Trp, which was predicted to inhibit the DR6-NAPP interaction through hydrogen bonding with key NAPP residues. Future work will include synthesizing and testing the top peptides to validate the computational predictions.
Application of formal methods for system level verification of finalVinita Palaniveloo
The document describes a formal modeling approach called Heterogeneous Protocol Automata (HPA) for verifying Network-on-Chip (NoC) systems. HPA can model NoC components like routers, switches, and communication interfaces, as well as properties like routing algorithms, arbitration schemes, and buffer management. The document outlines an HPA model of a sample NoC and discusses verifying properties of the model like functional correctness and absence of deadlocks through translation to the SPIN model checker.
This document discusses correlations between the Standard Penetration Test (SPT) and Cone Penetration Test (CPT). It notes that while SPT is widely used, CPT provides more reliable and repeatable results. The document reviews research on expressing the relationship between SPT N-values and CPT cone resistance (qc) through ratios of qc/N. It presents Robertson and Campanella's method which uses the relationship (qc/pa)/N60 to determine soil behavior type from CPT and SPT data. While this is a simple method, it can cause confusion at boundary zones between soil types. Developing a CPT-SPT correlation provides additional geotechnical data based on the more common
Principal component analysis (PCA) was used to analyze the conformational diversity of Ras proteins based on X-ray crystal structures. PCA separated the structures into two main clusters corresponding to the GTP-bound and GDP-bound conformations, capturing over 57.4% of the variance in the first two principal components. PCA loading plots identified displacements of switch regions as dominant features describing the conformational differences.
PCA was also used to analyze interactions between ligands and protein structures of CYP3A4 based on molecular interaction fields calculated using grid probes. Consensus PCA separated the structures based on differences in interactions with hydrophobic probes. PCA score plots distinguished the homology model from crystal structures based on interactions with Phe304, Thr309 and
Parameterized Model Checking of Rendezvous SystemsFrancesco Spegni
A standard technique for solving the parameterized model
checking problem is to reduce it to the classic model checking problem of finitely many finite-state systems. This work considers some of the theoretical power and limitations of this technique. We focus on concurrent systems in which processes communicate via pairwise rendezvous, as well as the special cases of disjunctive guards and token passing; specifications are expressed in indexed temporal logic without the next operator; and the underlying network topologies are generated by suitable
Monadic Second Order Logic formulas and graph operations. First, we settle the exact computational complexity of the parameterized model checking problem for some of our concurrent systems, and establish new
decidability results for others. Second, we consider the cases that model checking the parameterized system can be reduced to model checking some fixed number of processes, the number is known as a cutoff. We
provide many cases for when such cutoffs can be computed, establish lower bounds on the size of such cutoffs, and identify cases where no cutoff exists. Third, we consider cases for which the parameterized system
is equivalent to a single finite-state system (more precisely a Buchi word automaton), and establish tight bounds on the sizes of such automata.
This document summarizes research using laser speckle contrast imaging (LSCI) to study pulsatile blood flow dynamics in cerebral vasculature. LSCI allows non-invasive monitoring of cerebral blood flow with high temporal resolution. The research aims to quantify differences in pulsatile flow between arteries and veins and investigate neurovascular coupling. Preliminary results show LSCI can record at sample rates up to 9,072 frames per second and detect a 13ms difference in rise time between arterial and venous blood flow pulses. Further studies could separate arteries and veins, record hemodynamics after neural stimulation, and integrate LSCI with other imaging modalities.
An overview of the Phonopy (and Phono3py) lattice-dynamics codes, covering features, examples, applications and troubleshooting (2014 presentation updated for 2015).
Attentive semantic alignment with offset aware correlation kernelsNAVER Engineering
Semantic correspondence is the problem of establishing correspondences across images depicting different instances of the same object or scene class. One of recent approaches to this problem is to estimate parameters of a global transformation model that densely aligns one image to the other. Since an entire correlation map between all feature pairs across images is typically used to predict such a global transformation, noisy features from different backgrounds, clutter, and occlusion distract the predictor from correct estimation of the alignment. This is a challenging issue, in particular, in the problem of semantic correspondence where a large degree of image variations is often involved. In this paper, we introduce an attentive semantic alignment method that focuses on reliable correlations, filtering out distractors. For effective attention, we also propose an offset-aware correlation kernel that learns to capture translation-invariant local transformations in computing correlation values over spatial locations. Experiments demonstrate the effectiveness of the attentive model and offset-aware kernel, and the proposed model combining both techniques achieves the state-of-the-art performance.
The document presents Distributed Context Petri Nets (DCoPNs) for modeling context-dependent behavior in adaptive systems. DCoPNs extend Context Petri Nets with context dependency relations and runtime consistency checks. A mobile city guide example illustrates how DCoPNs capture context adaptations and ensure consistent interactions between contexts. The approach was validated in modeling and analyzing self-adaptive systems using Context Petri Nets.
Talk presented at the 2019 Context-oriented programming workshop colocated with ECOOP in london.
This work presents an extension to Context petri nets (CoPN) to enable the communication between different nodes, each defined using a CoPN. This extension demonstrates the interaction with different context dependency relations in face of unannounced connection and disconnection of nodes.
This study used computational methods to identify peptide inhibitors of the interaction between the death receptor DR6 and the N-terminal fragment of amyloid precursor protein (NAPP), which is implicated in Alzheimer's disease (AD). A focused peptide library was virtually screened and peptides were docked and scored against the NAPP binding site. Several tetrapeptides were predicted to bind strongly to NAPP, particularly Pro-Lys-Trp-Trp, which was predicted to inhibit the DR6-NAPP interaction through hydrogen bonding with key NAPP residues. Future work will include synthesizing and testing the top peptides to validate the computational predictions.
Application of formal methods for system level verification of finalVinita Palaniveloo
The document describes a formal modeling approach called Heterogeneous Protocol Automata (HPA) for verifying Network-on-Chip (NoC) systems. HPA can model NoC components like routers, switches, and communication interfaces, as well as properties like routing algorithms, arbitration schemes, and buffer management. The document outlines an HPA model of a sample NoC and discusses verifying properties of the model like functional correctness and absence of deadlocks through translation to the SPIN model checker.
Similar to Consistency of Chordal RCC-8 Networks (10)
Application of formal methods for system level verification of final
Consistency of Chordal RCC-8 Networks
1. Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Consistency of Chordal RCC-8 Networks
Outline
Introduction
PyRCC8
Michael Sioutis
-Path
Consistency
Department of Informatics and Telecommunications
Experimental
Results National and Kapodistrian University of Athens
Conclusions
Future Work November 8, 2012
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
2. Table of Contents
Consistency
of Chordal
RCC-8
Networks
1 Introduction
Michael
Sioutis
2 PyRCC8
Outline
Introduction
PyRCC8
3 -Path Consistency
-Path
Consistency
4 Experimental Results
Experimental
Results
Conclusions 5 Conclusions
Future Work
Acknowledge 6 Future Work
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
3. What is Qualitative Spatial Reasoning?
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
Qualitative spatial reasoning is based on qualitative
Introduction
PyRCC8
abstractions of spatial aspects of the common-sense
-Path
background knowledge, on which our human perspective
Consistency on the physical reality is based
Experimental
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
4. Reasons for Qualitative Spatial Reasoning
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline Two main reasons why non-precise, qualitative spatial
Introduction information may be useful:
PyRCC8
1 Only partial information may be available
-Path
Consistency 2 Spatial constraints are often most naturally stated in
Experimental qualitative terms
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
5. Applications of Qualitative Spatial Reasoning
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Qualitative spatial reasoning is an important subproblem
Outline
in many applications, such as:
Introduction
PyRCC8 Robotic navigation
-Path
High level vision
Consistency Geographical information systems (GIS)
Experimental Reasoning and querying with semantic geospatial query
Results
languages (e.g., stSPARQL, GeoSPARQL)
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
6. Region Connection Calculus
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
The Region Connection Calculus (RCC) is a first-order
Introduction
language for representation of and reasoning about
PyRCC8
topological relationships between extended spatial regions
-Path RCC abstractly describes regions, that are non-empty
Consistency
Experimental
regural subsets of some topological space which do not
Results have to be internally connected
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
7. The RCC-8 Calculus
Consistency
of Chordal
RCC-8
Networks
Michael
RCC-8 is a constraint language formed by the combination
Sioutis
of the following eight jointly exhaustive and pairwise
Outline disjoint base relations:
Introduction
disconnected (DC)
PyRCC8 externally connected (EC)
-Path
Consistency
equal (EQ)
partially overlapping (PO)
Experimental
Results tangential proper part (TPP)
Conclusions tangential proper part inverse (TPPi)
Future Work non-tangential proper part (NTPP)
Acknowledge non-tangential proper part inverse (NTPPi)
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
8. The Eight Basic Relations of the RCC-8 Calculus
Consistency
of Chordal
RCC-8
Networks
Michael Y Y
X Y X Y
Sioutis X X
X DC Y X EC Y X TPP Y X NTPP Y
Outline
Introduction
X X X
X Y
Y Y
PyRCC8 Y
-Path X PO Y X EQ Y X TPPi Y X NTPPi Y
Consistency
Experimental Figure: Two dimesional examples for the eight base relations of RCC-8
Results
Conclusions
Future Work From these basic relations, combinations can be built. For
Acknowledge
example, proper part (PP) is the union of TPP and NTPP.
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
9. The RCC-8 Composition Table
Consistency
of Chordal DC EC PO TPP NTPP TPPi NTPPi EQ
RCC-8 DC,EC DC,EC DC,EC DC,EC
Networks DC * PO,TPP PO,TPP PO,TPP PO,TPP DC DC DC
NTPP NTPP NTPP NTPP
Michael
DC,EC DC,EC DC,EC EC,PO PO
Sioutis
EC PO,TPPi PO,TPP PO,TPP TPP TPP DC,EC DC EC
NTPPi TPPi,EQ NTPP NTPP NTPP
Outline DC,EC DC,EC PO PO DC,EC DC,EC
PO PO,TPPi PO,TPPi * TPP TPP PO,TPPi PO,TPPi PO
Introduction NTPPi NTPPi NTPP NTPP NTPPi NTPPi
DC,EC TPP DC,EC DC,EC
PyRCC8
TPP DC DC,EC PO,TPP NTPP NTPP PO,TPP PO,TPPi TPP
-Path NTPP TPPi,EQ NTPPi
Consistency DC,EC DC,EC
NTPP DC DC PO,TPP NTPP NTPP PO,TPP * NTPP
Experimental NTPP NTPP
Results DC,EC EC,PO PO PO,EQ PO TPPi
TPPi PO,TPPi TPPi TPPi TPP TPP NTPPi NTPPi TPPi
Conclusions NTPPi NTPPi NTPPi TPPi NTPP
DC,EC PO PO PO PO,TPP
Future Work
NTPPi PO TPPi TPPi TPPi NTPP NTPPi NTPPi NTPPi
Acknowledge TPPi NTPPi NTPPi NTPPi NTPPi
NTPPi TPPi,EQ
Bibliography
EQ DC EC PO TPP NTPP TPPi NTPPi EQ
Michael Sioutis Consistency of Chordal RCC-8 Networks
10. The RSAT Reasoning Problem
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis RSAT in the RCC-8 framework is the reasoning problem of
Outline
deciding whether there is a spatial configuration where the
Introduction relations between the regions can be described by a spatial
PyRCC8 formula Θ
-Path
Consistency
RSAT is NP-Complete!
Experimental
ˆ
However, tractable subsets S of RCC-8 exist, such as H8 ,
Results
C8 , Q8 [5], for which the consistency problem can be
Conclusions
decided in polynomial time
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
11. The RSAT Reasoning Problem
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis RSAT in the RCC-8 framework is the reasoning problem of
Outline
deciding whether there is a spatial configuration where the
Introduction relations between the regions can be described by a spatial
PyRCC8 formula Θ
-Path
Consistency
RSAT is NP-Complete!
Experimental
ˆ
However, tractable subsets S of RCC-8 exist, such as H8 ,
Results
C8 , Q8 [5], for which the consistency problem can be
Conclusions
decided in polynomial time
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
12. The RSAT Reasoning Problem
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis RSAT in the RCC-8 framework is the reasoning problem of
Outline
deciding whether there is a spatial configuration where the
Introduction relations between the regions can be described by a spatial
PyRCC8 formula Θ
-Path
Consistency
RSAT is NP-Complete!
Experimental
ˆ
However, tractable subsets S of RCC-8 exist, such as H8 ,
Results
C8 , Q8 [5], for which the consistency problem can be
Conclusions
decided in polynomial time
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
13. Path Concistency
Consistency
of Chordal
RCC-8
Networks
Approximates consistency and realizes forward checking in
Michael
Sioutis a backtracking algorithm
Outline
Checks the consistency of triples of relations and
Introduction
eliminates relations that are impossible though iteravely
PyRCC8 performing the operation
-Path
Consistency Rij ← Rij ∩ Rik Rkj
Experimental
Results until a fixed point R is reached
Conclusions If Rij = ∅ for a pair (i, j) then R is inconsistent, otherwise
Future Work R is path-consistent.
Acknowledge
Computing R is done in O(n3 )
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
14. About PyRCC8..
Consistency
of Chordal
RCC-8
Networks
PyRCC81 is an efficient qualitative spatial reasoner written
Michael
Sioutis in pure Python. It employs PyPy2 , a fast, compliant
implementation of the Python 2 language
Outline
Introduction
PyRCC8
-Path
Consistency
Experimental
Results PyRCC8 offers a path consistency algorithm for solving
Conclusions tractable RCC-8 networks and a backtracking-based
Future Work algorithm for general networks
Acknowledge
Bibliography
1
http://pypi.python.org/pypi/PyRCC8
2
http://pypy.org/
Michael Sioutis Consistency of Chordal RCC-8 Networks
15. Comparing PC Implementations of Different
Reasoners
Consistency
of Chordal
RCC-8
Networks We compare the PC implementation of PyRCC8 to the PC
Michael implementations of the following qualitative spatial
Sioutis
reasoners:
Outline
Renz’s solver3
Introduction
GQR4
PyRCC8
Pellet Spatial5
-Path
Consistency
The admingeo6 dataset (11761 regions / 77910 relations)
Experimental
Results was used which was properly translated to fit the input
Conclusions format of the different PC implementations
Future Work
Acknowledge
3
Bibliography http://users.rsise.anu.edu.au/%7Ejrenz/software/rcc8-csp-solving.tar.gz
4
http://sfbtr8.informatik.uni-freiburg.de/R4LogoSpace/Tools/gqr.html
5
http://clarkparsia.com/pellet/spatial/
6
http://data.ordnancesurvey.co.uk/ontology/admingeo/
Michael Sioutis Consistency of Chordal RCC-8 Networks
16. Evaluation with a Large Dataset
Consistency
of Chordal
RCC-8
Networks Performance of four QSRs for the admingeo dataset
105
Michael
Sioutis
104
Outline 103
Introduction
102
CPU time (sec)
PyRCC8
-Path 101
Consistency
Experimental
100
Results
10-1 Renz
Conclusions
PyRCC8
Future Work 10 -2
GQR
Pellet-Spatial
Acknowledge
10-3 0 10000 20000 30000 40000 50000 60000 70000
Bibliography Number of relations
Michael Sioutis Consistency of Chordal RCC-8 Networks
17. Consistency
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
To explore the search space for the general case of RCC-8
Outline
Introduction
networks in order to solve an instance Θ of RSAT, some
PyRCC8
sort of backtracking must be used
-Path We implemented two backtracking algorithms:
Consistency
Experimental 1 A strictly recursive one
Results 2 An equivalent iterative one which resembles recursion
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
18. Comparing PyRCC8 to Other Reasoners
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
We compare PyRCC8 to the following qualitative spatial
Outline reasoners:
Introduction
Renz’s solver7
PyRCC8
GQR8
-Path
Consistency
Different size n of instances from A(n, d = 9.5, l = 4.0)
Experimental
Results were used
Conclusions
Future Work
Acknowledge
Bibliography
7
http://users.rsise.anu.edu.au/%7Ejrenz/software/rcc8-csp-solving.tar.gz
8
http://sfbtr8.informatik.uni-freiburg.de/R4LogoSpace/Tools/gqr.html
Michael Sioutis Consistency of Chordal RCC-8 Networks
19. Comparison Diagram
Consistency
of Chordal
RCC-8
Networks Performance of three QSRs for A(n,d=9.5,l=4.0)
102
Michael Renz
Sioutis PyRCC8
GQR
Outline 101
Introduction
CPU time (sec)
PyRCC8
-Path 100
Consistency
Experimental
Results
10-1
Conclusions
Future Work
Acknowledge
10-2
100 200 300 400 500 600 700 800 900
Bibliography Number of nodes
Michael Sioutis Consistency of Chordal RCC-8 Networks
20. -Path Concistency
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
Up till now, all aproaches in qualitative spatial reasoning
Introduction
enforce path consistency on a complete spatial network
PyRCC8 We propose enforcing path consistency on a chordal
-Path spatial network [2] as Chmeiss and Condotta have done for
Consistency
Experimental
temporal networks [3], and we call this type of local
Results consistency as -path consistency for clarity
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
21. -Path Concistency
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
Up till now, all aproaches in qualitative spatial reasoning
Introduction
enforce path consistency on a complete spatial network
PyRCC8 We propose enforcing path consistency on a chordal
-Path spatial network [2] as Chmeiss and Condotta have done for
Consistency
Experimental
temporal networks [3], and we call this type of local
Results consistency as -path consistency for clarity
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
22. Chordal Graph
Consistency
of Chordal
RCC-8
A graph is chordal if each of its cycles of four or more
Networks nodes has a chord, which is an edge joining two nodes
Michael
Sioutis
that are not adjacent in the cycle
An example of a chordal graph is shown below:
Outline
Introduction
PyRCC8
-Path
Consistency
Experimental
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
23. Triangulation
Consistency
of Chordal
RCC-8
Networks
Michael Triangulation of a given graph is done by eliminating the
Sioutis
vertices one by one and connecting all vertices in the
Outline
neighbourhood of each eliminated vertex with fill edges
Introduction
PyRCC8
Determining a minimum triangulation is an NP-hard
-Path
problem
Consistency
Use of several heuristics for sub-optimal solutions (e.g.
Experimental
Results minimum degree, minimum fill)
Conclusions
Chordality checking can be done efficiently in O(|V | + |E |)
Future Work
time, for a graph G = (V , E ) (e.g., with MCS, LexBFS)
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
24. Preliminaries
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Let G = (V , E ) be an undirected chordal graph. There
Outline exists a tree T , called a clique tree of G , whose vertex set
Introduction
is the set of maximal cliques of G
PyRCC8
-Path
Let C be a constraint network from a given CSP. Then,
Consistency VC refers to the set of variables of C
Experimental
Results If V is any set of variables, CV will be the constraint
Conclusions network C that involves variables of V
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
25. Patchwork Property in RCC-8 Networks
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Definition
Outline
We will say that a CSP has the patchwork property if for any
Introduction
finite satisfiable constraint networks C and C of the CSP such
PyRCC8
that CVC ∩VC = C VC ∩VC , the constraint network C ∪ C is
-Path satisfiable [4].
Consistency
Experimental
Results
Proposition
Conclusions ˆ
The three CSPs for path consistent H8 , C8 , and Q8 networks,
Future Work respectively, all have patchwork [4].
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
26. Proposition
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Proposition
Outline
Introduction Let C be an RCC-8 constraint network with relations from
PyRCC8 ˆ
H8 , C8 , and Q8 on its edges. Let G be the chordal graph that
-Path results from triangulating the associated constraint graph of C ,
Consistency
Experimental
and T a clique tree of G . C is consistent if all the networks
Results corresponding to the nodes of T are path consistent.
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
28. PyRCC8
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline PyRCC8 is a chordal reasoner which was developed by
Introduction extending PyRCC8
PyRCC8
Similarly to PyRCC8, PyRCC8 offers a -path
-Path
Consistency consistency algorithm for solving tractable RCC-8 networks
Experimental and a backtracking-based algorithm for general networks
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
29. -Path Consistency Algorithm
Consistency
of Chordal
RCC-8 -Path-Consistency(C, G)
Networks Input: A constraint network C and its chordal graph G
Michael Output: True or False
Sioutis
1: Q ← {(i, j) | (i, j) ∈ E } // Initialize the queue
2: while Q is not empty do
Outline 3: select and delete an (i, j) from Q
4: for each k such that (i, k), (k, j) ∈ E do
Introduction 5: t ← Cik ∩ (Cij Cjk )
6: if t = Cik then
PyRCC8
7: if t = ∅ then
-Path 8: return False
Consistency 9: Cik ← t
10: Cki ← ˘ t
Experimental 11: Q ← Q ∪ {(i, k)}
Results 12: t ← Ckj ∩ (Cki Cij )
13: if t = Ckj then
Conclusions 14: if t = ∅ then
15: return False
Future Work 16: Ckj ← t
Acknowledge 17: Cjk ← ˘ t
18: Q ← Q ∪ {(k, j)}
Bibliography 19:return True
Michael Sioutis Consistency of Chordal RCC-8 Networks
30. Complexity Analysis
Consistency
of Chordal
RCC-8
Networks
Michael Let δ denote the maximum degree of a vertex of G
Sioutis
For each arc (i, j) selected at line 3, we have at most δ
Outline
vertices of G corresponding to index k such that vi , vj , vk
Introduction
forms a triangle
PyRCC8
-Path
Additionaly, there exist |E | arcs in the network and one
Consistency can remove at most |B|9 values from any relation that
Experimental
Results
corresponds to an arc
Conclusions It results that the time complexity of -path consistency
Future Work is O(δ · |E | · |B|)
Acknowledge
Bibliography
9
B refers to the set of base relations of RCC-8
Michael Sioutis Consistency of Chordal RCC-8 Networks
31. Recursive -Consistency Algorithm
Consistency
of Chordal
RCC-8
Networks
Michael -Consistency(C, G)
Sioutis Input: A constraint network C and its chordal graph G
Output: A refined constraint network C’ if C is satisfiable or None
Outline
1: if not -Path-Consistency(C, G) then
Introduction 2: return None
3: if no constraint can be split then
PyRCC8 4: return C
5: else
-Path 6: choose unprocessed constraint xi Rxj ; split R into S1 , ..., Sk ∈ S: S1 ∪ ... ∪ Sk = R
Consistency 7: Values ← {Sl | 1 ≤ l ≤ k}
8: for V in Values do
Experimental 9: replace xi Rxj with xi Vxj in C
Results 10: result = -Consistency(C, G)
11: if result = None then
Conclusions
12: return result
Future Work 13: return None
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
32. Iterative -Consistency Algorithm
Consistency
of Chordal -Consistency(C, G)
RCC-8 Input: A constraint network C, A chordal graph G
Networks Output: A refined constraint network C’ if C is satisfiable or None
Michael 1: Stack ← {} // Initialize stack
Sioutis 2: if not -Path-Consistency(C, G) then
3: return None
4: while 1 do
Outline
5: if no constraint can be split then
Introduction 6: return C
7: else
PyRCC8 8: choose unprocessed constraint xi Rxj ; split R into S1 , ..., Sk ∈ S: S1 ∪ ... ∪ Sk = R
9: Values ← {Sl | 1 ≤ l ≤ k}
-Path 10: while 1 do
Consistency 11: if not Values then
12: while Stack do
Experimental 13: C, Values = Stack.pop()
Results 14: if Values then
15: break
Conclusions
16: else
Future Work 17: return None
18: V = Values.pop()
Acknowledge 19: replace xi Rxj with xi Vxj in C
20: if -Path-Consistency(C, G) then
Bibliography 21: break
22: Stack.push(C, Values)
23:raise RuntimeError, Can’t happen
Michael Sioutis Consistency of Chordal RCC-8 Networks
33. Comparing PyRCC8 to PyRCC8
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline We compare PyRCC8 to PyRCC8, a complete graph
Introduction dedicated reasoner, using the following data:
PyRCC8
Random instances composed from the set of all RCC-8
-Path
Consistency
relations
Experimental
The admingeo10 dataset
Results
Conclusions
Future Work
Acknowledge
Bibliography
10
http://data.ordnancesurvey.co.uk/ontology/admingeo/
Michael Sioutis Consistency of Chordal RCC-8 Networks
34. Experimenting with Random Instances
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis We generated instances from A(100, d, l = 4.0), for d
varying from 3 to 15 with a step of 0.5. For each series,
Outline
Introduction
300 networks were generated using Renz’s network
PyRCC8
generator11
-Path We used the Horn relations set as our split set, and the
Consistency
dynamic/local constraint scheme with a weighted queue
Experimental
Results configuration, since it proved to be the best combination
Conclusions for both reasoners, confirming the results in [5]
Future Work
Acknowledge
Bibliography
11
http://users.rsise.anu.edu.au/%7Ejrenz/software/rcc8-csp-solving.tar.gz
Michael Sioutis Consistency of Chordal RCC-8 Networks
35. Comparison Diagram on CPU time
Consistency
of Chordal
RCC-8
Networks Performance of function Consistency for A(100,d,l=4.0)
0.70
Michael PyRCC8
Sioutis
0.65
PyRCC8
Outline
0.60
Introduction
CPU time (sec)
PyRCC8 0.55
-Path
Consistency 0.50
Experimental
Results 0.45
Conclusions
0.40
Future Work
Acknowledge 0.35 4 6 8 10 12 14
Bibliography Average degree of network for non trivial constraints
Michael Sioutis Consistency of Chordal RCC-8 Networks
36. Comparison Diagram on # of Revised Arcs
Consistency
of Chordal
RCC-8
Networks Performance of function Consistency for A(100,d,l=4.0)
3000
Michael PyRCC8
Sioutis PyRCC8
2500
Outline
Introduction 2000
# of revised arcs
PyRCC8
-Path 1500
Consistency
Experimental 1000
Results
Conclusions
500
Future Work
Acknowledge 0 4 6 8 10 12 14
Bibliography Average degree of network for non trivial constraints
Michael Sioutis Consistency of Chordal RCC-8 Networks
37. Comparison Diagram on # of Checked Constraints
Consistency
of Chordal
RCC-8
Networks Performance of function Consistency for A(100,d,l=4.0)
300000
Michael PyRCC8
Sioutis PyRCC8
250000
Outline
# of consistency checks
Introduction 200000
PyRCC8
-Path 150000
Consistency
Experimental 100000
Results
Conclusions
50000
Future Work
Acknowledge 0 4 6 8 10 12 14
Bibliography Average degree of network for non trivial constraints
Michael Sioutis Consistency of Chordal RCC-8 Networks
38. Results Summary
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
PyRCC8 PyRCC8 %
Introduction CPU time 0.524s 0.509s 2.80%
PyRCC8 revised arcs 1300.681 801.204 38.40%
-Path checked constraints 105751.173 74864.985 29.21%
Consistency
Experimental Table: Comparison based on the average of different parameters
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
39. Experimenting with the Admingeo Dataset
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
The admingeo12 dataset consists of 11761 regions and
Outline 77910 base relations, thus being an extremely large and
Introduction sparse network, making itself a good candidate for stress
PyRCC8 testing different path consistency implementations
-Path
Consistency We used a simple queue configuration, since the weighted
Experimental variants made no difference on this dataset other than
Results
using much more memory
Conclusions
Future Work
Acknowledge
Bibliography
12
http://data.ordnancesurvey.co.uk/ontology/admingeo/
Michael Sioutis Consistency of Chordal RCC-8 Networks
40. Comparison Diagram on CPU Time
Consistency
of Chordal
RCC-8
Networks Performance of function PC for the admingeo dataset
105
Michael PyRCC8
Sioutis PyRCC8
104
Outline
Introduction 103
CPU time (sec)
PyRCC8
-Path 102
Consistency
Experimental 101
Results
Conclusions
100
Future Work
Acknowledge
10-1 0 10000 20000 30000 40000 50000 60000 70000
Bibliography Number of relations
Michael Sioutis Consistency of Chordal RCC-8 Networks
41. Comparison Diagram on # of Revised Arcs
Consistency
of Chordal
RCC-8
Networks Performance of function PC for the admingeo dataset
108
Michael PyRCC8
Sioutis
107
PyRCC8
Outline
106
Introduction
# of revised arcs
PyRCC8 105
-Path
Consistency 104
Experimental
Results 103
Conclusions
Future Work
102
Acknowledge
101 0 10000 20000 30000 40000 50000 60000 70000
Bibliography Number of relations
Michael Sioutis Consistency of Chordal RCC-8 Networks
42. Comparison Diagram on # of Checked Constraints
Consistency
of Chordal
RCC-8
Networks Performance of function PC for the admingeo dataset
1012
Michael PyRCC8
Sioutis 1011 PyRCC8
1010
Outline
109
# of consistency checks
Introduction
PyRCC8 108
-Path 107
Consistency
106
Experimental
Results 105
Conclusions 104
Future Work 103
Acknowledge
102 0 10000 20000 30000 40000 50000 60000 70000
Bibliography Number of relations
Michael Sioutis Consistency of Chordal RCC-8 Networks
43. Results Summary
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
PyRCC8 PyRCC8 %
Introduction CPU time 1825.129s 289.203s 84.15%
PyRCC8 revised arcs 4834133.78 373080.28 92.28%
-Path checked constraints 3.606e + 10 1.181e + 09 96.72%
Consistency
Experimental Table: Comparison based on the average of different parameters
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
44. Test Machine
Consistency
of Chordal
RCC-8
Networks
Michael All experiments were carried out on a computer with an
Sioutis
Intel Xeon 4 Core X3220 processor with a CPU frequency
Outline of 2.40 GHz, 8 GB RAM, and the Debian Lenny x86 64 OS
Introduction
Renz’s solver and GQR were compiled with gcc/g++ 4.4.3
PyRCC8
-Path PelletSpatial was run with OpenJDK 6 build 19, which
Consistency
implements Java SE 6
Experimental
Results PyRCC8 was run with PyPy 1.8, which implements
Conclusions Python 2.7.2
Future Work
Only one of the CPU cores was used for the experiments
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
45. Conclusions
Consistency
of Chordal
RCC-8 We made the case for a new generation of RCC-8
Networks
reasoners implemented in Python, and making use of
Michael
Sioutis advanced Python environments, such as PyPy, utilizing
trace-based JIT compilation techniques
Outline
Introduction We introduced -path consistency for RCC-8 networks
PyRCC8 We showed that -path consistency is sufficient to decide
-Path
Consistency
the consistency problem for the maximal tractable subsets
ˆ
H8 , C8 , and Q8 of RCC-8
Experimental
Results
We implemented a chordal graph dedicated reasoner for
Conclusions
Future Work
RCC-8 networks
Acknowledge We showed expirimentally that -path consistency can
Bibliography offer a great advantage over full path consistency on
sparse graphs
Michael Sioutis Consistency of Chordal RCC-8 Networks
46. Main Points
Consistency
of Chordal
RCC-8
Networks
Michael Explore self learning heuristics regarding variable and value
Sioutis
selection
Outline Create module to generate spatial CSPs
Introduction
Transform PyRCC8 into a generic qualitative reasoner
PyRCC8
-Path Use other methods of triangulation and compare the
Consistency
behavior of partial path consistency for these different
Experimental
Results methods
Conclusions Perform experiments with other possible real datasets,
Future Work
such as GADM13
Acknowledge
Bibliography
13
http://gadm.geovocab.org/
Michael Sioutis Consistency of Chordal RCC-8 Networks
47. Acknowledge
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline This work was funded by the FP7 project TELEIOS
Introduction (257662)
PyRCC8
I would also like to thank my colleagues, and Katia
-Path
Consistency Papakonstantinopoulou especially, for their help, interest,
Experimental and advice
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks
48. References
Consistency
of Chordal
RCC-8 [Van Beek and Manchak]
Networks
The design and experimental analysis of algorithms for temporal reasoning
Michael JAIR, vol. 4, pages 1–18, 1996
Sioutis
[Bliek and Sam-Haroud]
Outline Path Consistency on Triangulated Constraint Graphs
Introduction In IJCAI, 1999
PyRCC8 [Chmeiss and Condotta]
-Path
Consistency of Triangulated Temporal Qualitative Constraint Networks
Consistency In ICTAI, 2011
Experimental [Huang]
Results
Compactness and Its Implications for Qualitative Spatial and Temporal
Conclusions Reasoning
Future Work In KR, 2012
Acknowledge [Renz and Nebel]
Bibliography
Efficient Methods for Qualitative Spatial Reasoning
JAIR, vol. 15, pages 289–318, 2001
Michael Sioutis Consistency of Chordal RCC-8 Networks
49. The End
Consistency
of Chordal
RCC-8
Networks
Michael
Sioutis
Outline
Introduction
PyRCC8
Any Questions?
-Path
Consistency
Experimental
Results
Conclusions
Future Work
Acknowledge
Bibliography
Michael Sioutis Consistency of Chordal RCC-8 Networks