Cyberattack triage using incremental clustering for intrusion detection systems
- Taheri, Sona, Bagirov, Adil, Gondal, Iqbal, Brown, Simon
- Authors: Taheri, Sona , Bagirov, Adil , Gondal, Iqbal , Brown, Simon
- Date: 2020
- Type: Text , Journal article
- Relation: International Journal of Information Security Vol. 19, no. 5 (2020), p. 597-607
- Relation: http://purl.org/au-research/grants/arc/DP190100580
- Full Text:
- Reviewed:
- Description: Intrusion detection systems (IDSs) are devices or software applications that monitor networks or systems for malicious activities and signals alerts/alarms when such activity is discovered. However, an IDS may generate many false alerts which affect its accuracy. In this paper, we develop a cyberattack triage algorithm to detect these alerts (so-called outliers). The proposed algorithm is designed using the clustering, optimization and distance-based approaches. An optimization-based incremental clustering algorithm is proposed to find clusters of different types of cyberattacks. Using a special procedure, a set of clusters is divided into two subsets: normal and stable clusters. Then, outliers are found among stable clusters using an average distance between centroids of normal clusters. The proposed algorithm is evaluated using the well-known IDS data sets—Knowledge Discovery and Data mining Cup 1999 and UNSW-NB15—and compared with some other existing algorithms. Results show that the proposed algorithm has a high detection accuracy and its false negative rate is very low. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
- Description: This research was conducted in Internet Commerce Security Laboratory (ICSL) funded by Westpac Banking Corporation Australia. In addition, the research by Dr. Sona Taheri and A/Prof. Adil Bagirov was supported by the Australian Government through the Australian Research Council’s Discovery Projects funding scheme (DP190100580).
- Authors: Taheri, Sona , Bagirov, Adil , Gondal, Iqbal , Brown, Simon
- Date: 2020
- Type: Text , Journal article
- Relation: International Journal of Information Security Vol. 19, no. 5 (2020), p. 597-607
- Relation: http://purl.org/au-research/grants/arc/DP190100580
- Full Text:
- Reviewed:
- Description: Intrusion detection systems (IDSs) are devices or software applications that monitor networks or systems for malicious activities and signals alerts/alarms when such activity is discovered. However, an IDS may generate many false alerts which affect its accuracy. In this paper, we develop a cyberattack triage algorithm to detect these alerts (so-called outliers). The proposed algorithm is designed using the clustering, optimization and distance-based approaches. An optimization-based incremental clustering algorithm is proposed to find clusters of different types of cyberattacks. Using a special procedure, a set of clusters is divided into two subsets: normal and stable clusters. Then, outliers are found among stable clusters using an average distance between centroids of normal clusters. The proposed algorithm is evaluated using the well-known IDS data sets—Knowledge Discovery and Data mining Cup 1999 and UNSW-NB15—and compared with some other existing algorithms. Results show that the proposed algorithm has a high detection accuracy and its false negative rate is very low. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
- Description: This research was conducted in Internet Commerce Security Laboratory (ICSL) funded by Westpac Banking Corporation Australia. In addition, the research by Dr. Sona Taheri and A/Prof. Adil Bagirov was supported by the Australian Government through the Australian Research Council’s Discovery Projects funding scheme (DP190100580).
Ethnobotany, rattan agroforestry, and conservation of ecosystem services in Central Kalimantan, Indonesia
- Afentina, McShane, Paul, Wright, Wendy
- Authors: Afentina , McShane, Paul , Wright, Wendy
- Date: 2020
- Type: Text , Journal article
- Relation: Agroforestry Systems Vol. 94, no. 2 (2020), p. 639-650
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- Description: Rattan agroforestry is an important land use system in Central Kalimantan, Indonesia, providing a wide range of products for subsistence communities. The ethnobotanical importance of rattan includes heritage values reflecting traditional ecological knowledge. This traditional forestry practice is consistent with necessary conservation of biodiversity and ecosystem services currently threatened by expansion of oil palm plantations. We examined species composition and morphology (including life stages) of vegetation associated with rattan agroforests in the Katingan district, Central Kalimantan. An examination of harvested rattan plots revealed 101 species of vegetation of which 90% are considered to be useful (food, construction materials, medicines) and most (97%) were native species, typical of lowland tropical forest vegetation. Vegetation in the rattan agroforests was dominated by trees (in terms of species richness). There were 80 species of trees, representing 79% of the plants surveyed. Vitex pubescens (kaluan) had the highest importance value as it occupied more space, was represented by more individuals and was most frequently found in rattan gardens. These trees in general have a relatively open canopy with strong branches; properties considered ideal to support rattan. Canopy forming species are actively managed to provide for growth of useful understory vegetation (including rattan) important in the livelihoods of village communities. Rattan agroforests also provide cultural services reflecting traditional use (e.g. a sense of belonging and ancestral linkages for local forest-dependent communities). The importance of ethnobotanical approaches to rattan cultivation includes the socio-economic evaluation of land use and the promotion of sustainable land use policies in Indonesia. This is important in the context of oil palm expansion which has a demonstrably adverse impact on ecosystem services. © 2019, Springer Nature B.V.
- Authors: Afentina , McShane, Paul , Wright, Wendy
- Date: 2020
- Type: Text , Journal article
- Relation: Agroforestry Systems Vol. 94, no. 2 (2020), p. 639-650
- Full Text:
- Reviewed:
- Description: Rattan agroforestry is an important land use system in Central Kalimantan, Indonesia, providing a wide range of products for subsistence communities. The ethnobotanical importance of rattan includes heritage values reflecting traditional ecological knowledge. This traditional forestry practice is consistent with necessary conservation of biodiversity and ecosystem services currently threatened by expansion of oil palm plantations. We examined species composition and morphology (including life stages) of vegetation associated with rattan agroforests in the Katingan district, Central Kalimantan. An examination of harvested rattan plots revealed 101 species of vegetation of which 90% are considered to be useful (food, construction materials, medicines) and most (97%) were native species, typical of lowland tropical forest vegetation. Vegetation in the rattan agroforests was dominated by trees (in terms of species richness). There were 80 species of trees, representing 79% of the plants surveyed. Vitex pubescens (kaluan) had the highest importance value as it occupied more space, was represented by more individuals and was most frequently found in rattan gardens. These trees in general have a relatively open canopy with strong branches; properties considered ideal to support rattan. Canopy forming species are actively managed to provide for growth of useful understory vegetation (including rattan) important in the livelihoods of village communities. Rattan agroforests also provide cultural services reflecting traditional use (e.g. a sense of belonging and ancestral linkages for local forest-dependent communities). The importance of ethnobotanical approaches to rattan cultivation includes the socio-economic evaluation of land use and the promotion of sustainable land use policies in Indonesia. This is important in the context of oil palm expansion which has a demonstrably adverse impact on ecosystem services. © 2019, Springer Nature B.V.
Soil chemical markers distinguishing human and pig decomposition islands : a preliminary study
- Barton, Philip, Reboldi, Anna, Dawson, Blake, Ueland, Maiken, Strong, Craig, Wallman, James
- Authors: Barton, Philip , Reboldi, Anna , Dawson, Blake , Ueland, Maiken , Strong, Craig , Wallman, James
- Date: 2020
- Type: Text , Journal article
- Relation: Forensic Science, Medicine, and Pathology Vol. 16, no. 4 (2020), p. 605-612
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- Description: The decomposition of vertebrate cadavers on the soil surface produces nutrient-rich fluids that enter the soil profile, leaving clear evidence of the presence of a cadaver decomposition island. Few studies, however, have described soil physicochemistry under human cadavers, or compared the soil between human and non-human animal models. In this study, we sampled soil to 5 cm depth at distances of 0 cm and 30 cm from cadavers, as well as from control sites 90 cm distant, from five human and three pig cadavers at the Australian Facility for Taphonomic Experimental Research (AFTER). We found that soil moisture, electrical conductivity, nitrate, ammonium, and total phosphorus were higher in soil directly under cadavers (0 cm), with very limited lateral spread beyond 30 cm. These patterns lasted up to 700 days, indicating that key soil nutrients might be useful markers of the location of the decomposition island for up to 2 years. Soil phosphorus was always higher under pigs than humans, suggesting a possible difference in the decomposition and soil processes under these two cadaver types. Our preliminary study highlights the need for further experimental and replicated research to quantify variability in soil properties, and to identify when non-human animals are suitable analogues. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
- Authors: Barton, Philip , Reboldi, Anna , Dawson, Blake , Ueland, Maiken , Strong, Craig , Wallman, James
- Date: 2020
- Type: Text , Journal article
- Relation: Forensic Science, Medicine, and Pathology Vol. 16, no. 4 (2020), p. 605-612
- Full Text:
- Reviewed:
- Description: The decomposition of vertebrate cadavers on the soil surface produces nutrient-rich fluids that enter the soil profile, leaving clear evidence of the presence of a cadaver decomposition island. Few studies, however, have described soil physicochemistry under human cadavers, or compared the soil between human and non-human animal models. In this study, we sampled soil to 5 cm depth at distances of 0 cm and 30 cm from cadavers, as well as from control sites 90 cm distant, from five human and three pig cadavers at the Australian Facility for Taphonomic Experimental Research (AFTER). We found that soil moisture, electrical conductivity, nitrate, ammonium, and total phosphorus were higher in soil directly under cadavers (0 cm), with very limited lateral spread beyond 30 cm. These patterns lasted up to 700 days, indicating that key soil nutrients might be useful markers of the location of the decomposition island for up to 2 years. Soil phosphorus was always higher under pigs than humans, suggesting a possible difference in the decomposition and soil processes under these two cadaver types. Our preliminary study highlights the need for further experimental and replicated research to quantify variability in soil properties, and to identify when non-human animals are suitable analogues. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
Projected changes in ENSO-driven regional tropical cyclone tracks
- Bell, Samuel, Chand, Savin, Turville, Christopher
- Authors: Bell, Samuel , Chand, Savin , Turville, Christopher
- Date: 2020
- Type: Text , Journal article
- Relation: Climate Dynamics Vol. 54, no. 3-4 (Feb 2020), p. 2533-2559
- Full Text:
- Reviewed:
- Description: Simulations and projections of the El Nino Southern Oscillation's (ENSO's) influence on TC track variability was analysed globally using Coupled Model Intercomparison project Phase 5 (CMIP5) models. The ability of these models to simulate the historical (1970-2000) ENSO-TC track relationship and inform us of the likely projected changes resulting from high carbon emissions (RCP8.5) in a climate projection (2070-2100) was determined through cluster analysis. The number of seasonal TC occurrences during traditional ENSO events ("El Nino" and "La Nina") in each cluster were used to determine whether each cluster was "El Nino dominant", "La Nina dominant" or "neither". Only seven out of a combined total of 28 clusters across all basins were found to disagree in terms of "ENSO dominance" between the observed records and historical model simulations. This suggests that models can simulate the ENSO and TC track relationship reasonably well. Under sustained high carbon emissions, La Nina TCs were projected to become dominant over El Nino TCs in the central South Indian Ocean ( 60-100 degrees E), the southern Bay of Bengal and over straight-moving TCs in the South China Sea. El Nino TCs were projected to increase and become dominant over La Nina TCs in a larger area of the western South Pacific ( 160 degrees E-165 degrees W) and central North Pacific ( 160 degrees E-145 degrees W) Oceans. Projections of track directions and lifetimes, while less robust, indicated that El Nino TCs would track westward more often in the Coral Sea (150-165 degrees E), while El Nino TCs that took an eastward track here would have longer lifetimes ( 3 days).
- Authors: Bell, Samuel , Chand, Savin , Turville, Christopher
- Date: 2020
- Type: Text , Journal article
- Relation: Climate Dynamics Vol. 54, no. 3-4 (Feb 2020), p. 2533-2559
- Full Text:
- Reviewed:
- Description: Simulations and projections of the El Nino Southern Oscillation's (ENSO's) influence on TC track variability was analysed globally using Coupled Model Intercomparison project Phase 5 (CMIP5) models. The ability of these models to simulate the historical (1970-2000) ENSO-TC track relationship and inform us of the likely projected changes resulting from high carbon emissions (RCP8.5) in a climate projection (2070-2100) was determined through cluster analysis. The number of seasonal TC occurrences during traditional ENSO events ("El Nino" and "La Nina") in each cluster were used to determine whether each cluster was "El Nino dominant", "La Nina dominant" or "neither". Only seven out of a combined total of 28 clusters across all basins were found to disagree in terms of "ENSO dominance" between the observed records and historical model simulations. This suggests that models can simulate the ENSO and TC track relationship reasonably well. Under sustained high carbon emissions, La Nina TCs were projected to become dominant over El Nino TCs in the central South Indian Ocean ( 60-100 degrees E), the southern Bay of Bengal and over straight-moving TCs in the South China Sea. El Nino TCs were projected to increase and become dominant over La Nina TCs in a larger area of the western South Pacific ( 160 degrees E-165 degrees W) and central North Pacific ( 160 degrees E-145 degrees W) Oceans. Projections of track directions and lifetimes, while less robust, indicated that El Nino TCs would track westward more often in the Coral Sea (150-165 degrees E), while El Nino TCs that took an eastward track here would have longer lifetimes ( 3 days).
Optimization of blasting design in open pit limestone mines with the aim of reducing ground vibration using robust techniques
- Rezaeineshat, Afsaneh, Monjezi, Masoud, Mehrdanesh, Amirhossein, Khandelwal, Manoj
- Authors: Rezaeineshat, Afsaneh , Monjezi, Masoud , Mehrdanesh, Amirhossein , Khandelwal, Manoj
- Date: 2020
- Type: Text , Journal article
- Relation: Geomechanics and Geophysics for Geo-Energy and Geo-Resources Vol. 6, no. 2 (2020), p.
- Full Text:
- Reviewed:
- Description: Blasting operations create significant problems to residential and other structures located in the close proximity of the mines. Blast vibration is one of the most crucial nuisances of blasting, which should be accurately estimated to minimize its effect. In this paper, an attempt has been made to apply various models to predict ground vibrations due to mine blasting. To fulfill this aim, 112 blast operations were precisely measured and collected in one the limestone mines of Iran. These blast operation data were utilized to construct the artificial neural network (ANN) model to predict the peak particle velocity (PPV). The input parameters used in this study were burden, spacing, maximum charge per delay, distance from blast face to monitoring point and rock quality designation and output parameter was the PPV. The conventional empirical predictors and multivariate regression analysis were also performed on the same data sets to study the PPV. Accordingly, it was observed that the ANN model is more accurate as compared to the other employed predictors. Moreover, it was also revealed that the most influential parameters on the ground vibration are distance from the blast and maximum charge per delay, whereas the least effective parameters are burden, spacing and rock quality designation. Finally, in order to minimize PPV, the developed ANN model was used as an objective function for imperialist competitive algorithm (ICA). Eventually, it was found that the ICA algorithm is able to decrease PPV up to 59% by considering burden of 2.9 m, spacing of 4.4 m and charge per delay of 627 Kg. © 2020, Springer Nature Switzerland AG.
- Authors: Rezaeineshat, Afsaneh , Monjezi, Masoud , Mehrdanesh, Amirhossein , Khandelwal, Manoj
- Date: 2020
- Type: Text , Journal article
- Relation: Geomechanics and Geophysics for Geo-Energy and Geo-Resources Vol. 6, no. 2 (2020), p.
- Full Text:
- Reviewed:
- Description: Blasting operations create significant problems to residential and other structures located in the close proximity of the mines. Blast vibration is one of the most crucial nuisances of blasting, which should be accurately estimated to minimize its effect. In this paper, an attempt has been made to apply various models to predict ground vibrations due to mine blasting. To fulfill this aim, 112 blast operations were precisely measured and collected in one the limestone mines of Iran. These blast operation data were utilized to construct the artificial neural network (ANN) model to predict the peak particle velocity (PPV). The input parameters used in this study were burden, spacing, maximum charge per delay, distance from blast face to monitoring point and rock quality designation and output parameter was the PPV. The conventional empirical predictors and multivariate regression analysis were also performed on the same data sets to study the PPV. Accordingly, it was observed that the ANN model is more accurate as compared to the other employed predictors. Moreover, it was also revealed that the most influential parameters on the ground vibration are distance from the blast and maximum charge per delay, whereas the least effective parameters are burden, spacing and rock quality designation. Finally, in order to minimize PPV, the developed ANN model was used as an objective function for imperialist competitive algorithm (ICA). Eventually, it was found that the ICA algorithm is able to decrease PPV up to 59% by considering burden of 2.9 m, spacing of 4.4 m and charge per delay of 627 Kg. © 2020, Springer Nature Switzerland AG.
Gateaux differentiability revisited
- Abbasi, Malek, Kruger, Alexander, Théra, Michel
- Authors: Abbasi, Malek , Kruger, Alexander , Théra, Michel
- Date: 2021
- Type: Text , Journal article
- Relation: Applied Mathematics and Optimization Vol. 84, no. 3 (2021), p. 3499-3516
- Relation: http://purl.org/au-research/grants/arc/DP160100854
- Full Text:
- Reviewed:
- Description: We revisit some basic concepts and ideas of the classical differential calculus and convex analysis extending them to a broader frame. We reformulate and generalize the notion of Gateaux differentiability and propose new notions of generalized derivative and generalized subdifferential in an arbitrary topological vector space. Meaningful examples preserving the key properties of the original notion of derivative are provided. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
- Authors: Abbasi, Malek , Kruger, Alexander , Théra, Michel
- Date: 2021
- Type: Text , Journal article
- Relation: Applied Mathematics and Optimization Vol. 84, no. 3 (2021), p. 3499-3516
- Relation: http://purl.org/au-research/grants/arc/DP160100854
- Full Text:
- Reviewed:
- Description: We revisit some basic concepts and ideas of the classical differential calculus and convex analysis extending them to a broader frame. We reformulate and generalize the notion of Gateaux differentiability and propose new notions of generalized derivative and generalized subdifferential in an arbitrary topological vector space. Meaningful examples preserving the key properties of the original notion of derivative are provided. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
An existence result for quasi-equilibrium problems via Ekeland’s variational principle
- Cotrina, John, Théra, Michel, Zúñiga, Javier
- Authors: Cotrina, John , Théra, Michel , Zúñiga, Javier
- Date: 2020
- Type: Text , Journal article
- Relation: Journal of Optimization Theory and Applications Vol. 187, no. 2 (2020), p. 336-355
- Full Text:
- Reviewed:
- Description: This paper deals with the existence of solutions to equilibrium and quasi-equilibrium problems without any convexity assumption. Coverage includes some equivalences to the Ekeland variational principle for bifunctions and basic facts about transfer lower continuity. An application is given to systems of quasi-equilibrium problems. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
- Description: Research of M. Théra is supported by the Australian Research Council (ARC) Grant DP160100854 and benefited from the support of the FMJH Program PGMO and from the support of EDF. http://purl.org/au-research/grants/arc/DP160100854
- Authors: Cotrina, John , Théra, Michel , Zúñiga, Javier
- Date: 2020
- Type: Text , Journal article
- Relation: Journal of Optimization Theory and Applications Vol. 187, no. 2 (2020), p. 336-355
- Full Text:
- Reviewed:
- Description: This paper deals with the existence of solutions to equilibrium and quasi-equilibrium problems without any convexity assumption. Coverage includes some equivalences to the Ekeland variational principle for bifunctions and basic facts about transfer lower continuity. An application is given to systems of quasi-equilibrium problems. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
- Description: Research of M. Théra is supported by the Australian Research Council (ARC) Grant DP160100854 and benefited from the support of the FMJH Program PGMO and from the support of EDF. http://purl.org/au-research/grants/arc/DP160100854
Characterizations of robust and stable duality for linearly perturbed uncertain optimization problems
- Dinh, Nguyen, Goberna, Miguel, López, Marco, Volle, Michel
- Authors: Dinh, Nguyen , Goberna, Miguel , López, Marco , Volle, Michel
- Date: 2020
- Type: Text , Conference paper
- Relation: Jonathan Borwein Commemorative Conference, JBCC 2017 Vol. 313, p. 43-74
- Relation: http://purl.org/au-research/grants/arc/DP180100602
- Full Text:
- Reviewed:
- Description: We introduce a robust optimization model consisting in a family of perturbation functions giving rise to certain pairs of dual optimization problems in which the dual variable depends on the uncertainty parameter. The interest of our approach is illustrated by some examples, including uncertain conic optimization and infinite optimization via discretization. The main results characterize desirable robust duality relations (as robust zero-duality gap) by formulas involving the epsilon-minima or the epsilon-subdifferentials of the objective function. The two extreme cases, namely, the usual perturbational duality (without uncertainty), and the duality for the supremum of functions (duality parameter vanishing) are analyzed in detail. © Springer Nature Switzerland AG 2020.
- Authors: Dinh, Nguyen , Goberna, Miguel , López, Marco , Volle, Michel
- Date: 2020
- Type: Text , Conference paper
- Relation: Jonathan Borwein Commemorative Conference, JBCC 2017 Vol. 313, p. 43-74
- Relation: http://purl.org/au-research/grants/arc/DP180100602
- Full Text:
- Reviewed:
- Description: We introduce a robust optimization model consisting in a family of perturbation functions giving rise to certain pairs of dual optimization problems in which the dual variable depends on the uncertainty parameter. The interest of our approach is illustrated by some examples, including uncertain conic optimization and infinite optimization via discretization. The main results characterize desirable robust duality relations (as robust zero-duality gap) by formulas involving the epsilon-minima or the epsilon-subdifferentials of the objective function. The two extreme cases, namely, the usual perturbational duality (without uncertainty), and the duality for the supremum of functions (duality parameter vanishing) are analyzed in detail. © Springer Nature Switzerland AG 2020.
Directional metric pseudo subregularity of set-valued mappings: a general model
- Van Ngai, Huynh, Tron, Nguyen, Van Vu, Nguyen, Théra, Michel
- Authors: Van Ngai, Huynh , Tron, Nguyen , Van Vu, Nguyen , Théra, Michel
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 1 (2020), p. 61-87
- Full Text:
- Reviewed:
- Description: This paper investigates a new general pseudo subregularity model which unifies some important nonlinear (sub)regularity models studied recently in the literature. Some slope and abstract coderivative characterizations are established. © 2019, Springer Nature B.V.
- Authors: Van Ngai, Huynh , Tron, Nguyen , Van Vu, Nguyen , Théra, Michel
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 1 (2020), p. 61-87
- Full Text:
- Reviewed:
- Description: This paper investigates a new general pseudo subregularity model which unifies some important nonlinear (sub)regularity models studied recently in the literature. Some slope and abstract coderivative characterizations are established. © 2019, Springer Nature B.V.
Stability analysis for parameterized variational systems with implicit constraints
- Benko, Matus, Gfrerer, Helmut, Outrata, Jiri
- Authors: Benko, Matus , Gfrerer, Helmut , Outrata, Jiri
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 1 (2020), p. 167-193
- Full Text:
- Reviewed:
- Description: In the paper we provide new conditions ensuring the isolated calmness property and the Aubin property of parameterized variational systems with constraints depending, apart from the parameter, also on the solution itself. Such systems include, e.g., quasi-variational inequalities and implicit complementarity problems. Concerning the Aubin property, possible restrictions imposed on the parameter are also admitted. Throughout the paper, tools from the directional limiting generalized differential calculus are employed enabling us to impose only rather weak (non- restrictive) qualification conditions. Despite the very general problem setting, the resulting conditions are workable as documented by some academic examples. © 2019, The Author(s).
- Authors: Benko, Matus , Gfrerer, Helmut , Outrata, Jiri
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 1 (2020), p. 167-193
- Full Text:
- Reviewed:
- Description: In the paper we provide new conditions ensuring the isolated calmness property and the Aubin property of parameterized variational systems with constraints depending, apart from the parameter, also on the solution itself. Such systems include, e.g., quasi-variational inequalities and implicit complementarity problems. Concerning the Aubin property, possible restrictions imposed on the parameter are also admitted. Throughout the paper, tools from the directional limiting generalized differential calculus are employed enabling us to impose only rather weak (non- restrictive) qualification conditions. Despite the very general problem setting, the resulting conditions are workable as documented by some academic examples. © 2019, The Author(s).
Stability prediction of Himalayan residual soil slope using artificial neural network
- Ray, Arunava, Kumar, Vikash, Kumar, Amit, Rai, Rajesh, Khandelwal, Manoj, Singh, T.
- Authors: Ray, Arunava , Kumar, Vikash , Kumar, Amit , Rai, Rajesh , Khandelwal, Manoj , Singh, T.
- Date: 2020
- Type: Text , Journal article
- Relation: Natural Hazards Vol. 103, no. 3 (2020), p. 3523-3540
- Full Text:
- Reviewed:
- Description: In the past decade, advances in machine learning (ML) techniques have resulted in developing sophisticated models that are capable of modelling extremely complex multi-factorial problems like slope stability analysis. The literature review indicates that considerable works have been done in slope stability using ML, but none of them covers the analysis of residual soil slope. The present study aims to develop an artificial neural network (ANN) model that can be employed for evaluating the factor of safety of Shiwalik Slopes in the Himalayan Region. Data obtained from numerical analysis of a residual soil slope were used to develop two ANN models (ANN1 and ANN2 utilising eleven input parameters, and scaled-down number of parameters based on correlation coefficient, respectively). A four-layer, feed-forward back-propagation neural network having the optimum number of hidden neurons is developed based on trial-and-error method. The results derived from ANN models were compared with those achieved from numerical analysis. Additionally, several performance indices such as coefficient of determination (R2), root mean square error, variance account for, and residual error were employed to evaluate the predictive performance of the developed ANN models. Both the ANN models have shown good prediction performance; however, the overall performance of the ANN2 model is better than the ANN1 model. It is concluded that the ANN models are reliable, valid, and straightforward computational tools that can be employed for slope stability analysis during the preliminary stage of designing infrastructure projects in residual soil slope. © 2020, Springer Nature B.V.
- Authors: Ray, Arunava , Kumar, Vikash , Kumar, Amit , Rai, Rajesh , Khandelwal, Manoj , Singh, T.
- Date: 2020
- Type: Text , Journal article
- Relation: Natural Hazards Vol. 103, no. 3 (2020), p. 3523-3540
- Full Text:
- Reviewed:
- Description: In the past decade, advances in machine learning (ML) techniques have resulted in developing sophisticated models that are capable of modelling extremely complex multi-factorial problems like slope stability analysis. The literature review indicates that considerable works have been done in slope stability using ML, but none of them covers the analysis of residual soil slope. The present study aims to develop an artificial neural network (ANN) model that can be employed for evaluating the factor of safety of Shiwalik Slopes in the Himalayan Region. Data obtained from numerical analysis of a residual soil slope were used to develop two ANN models (ANN1 and ANN2 utilising eleven input parameters, and scaled-down number of parameters based on correlation coefficient, respectively). A four-layer, feed-forward back-propagation neural network having the optimum number of hidden neurons is developed based on trial-and-error method. The results derived from ANN models were compared with those achieved from numerical analysis. Additionally, several performance indices such as coefficient of determination (R2), root mean square error, variance account for, and residual error were employed to evaluate the predictive performance of the developed ANN models. Both the ANN models have shown good prediction performance; however, the overall performance of the ANN2 model is better than the ANN1 model. It is concluded that the ANN models are reliable, valid, and straightforward computational tools that can be employed for slope stability analysis during the preliminary stage of designing infrastructure projects in residual soil slope. © 2020, Springer Nature B.V.
Some new characterizations of intrinsic transversality in hilbert spaces
- Thao, Nguyen, Bui, Hoa, Cuong, Nguyen, Verhaegen, Michel
- Authors: Thao, Nguyen , Bui, Hoa , Cuong, Nguyen , Verhaegen, Michel
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 1 (2020), p. 5-39
- Full Text:
- Reviewed:
- Description: Motivated by a number of questions concerning transversality-type properties of pairs of sets recently raised by Ioffe and Kruger, this paper reports several new characterizations of the intrinsic transversality property in Hilbert spaces. New results in terms of normal vectors clarify the picture of intrinsic transversality, its variants and sufficient conditions for subtransversality, and unify several of them. For the first time, intrinsic transversality is characterized by an equivalent condition which does not involve normal vectors. This characterization offers another perspective on intrinsic transversality. As a consequence, the obtained results allow us to answer a number of important questions about transversality-type properties. © 2020, The Author(s).
- Authors: Thao, Nguyen , Bui, Hoa , Cuong, Nguyen , Verhaegen, Michel
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 1 (2020), p. 5-39
- Full Text:
- Reviewed:
- Description: Motivated by a number of questions concerning transversality-type properties of pairs of sets recently raised by Ioffe and Kruger, this paper reports several new characterizations of the intrinsic transversality property in Hilbert spaces. New results in terms of normal vectors clarify the picture of intrinsic transversality, its variants and sufficient conditions for subtransversality, and unify several of them. For the first time, intrinsic transversality is characterized by an equivalent condition which does not involve normal vectors. This characterization offers another perspective on intrinsic transversality. As a consequence, the obtained results allow us to answer a number of important questions about transversality-type properties. © 2020, The Author(s).
Sequential sampling models without random between-trial variability : the racing diffusion model of speeded decision making
- Tillman, Gabriel, Van Zandt, Trish, Logan, Gordon
- Authors: Tillman, Gabriel , Van Zandt, Trish , Logan, Gordon
- Date: 2020
- Type: Text , Journal article , Review
- Relation: Psychonomic Bulletin and Review Vol. 27, no. 5 (2020), p. 911-936
- Full Text:
- Reviewed:
- Description: Most current sequential sampling models have random between-trial variability in their parameters. These sources of variability make the models more complex in order to fit response time data, do not provide any further explanation to how the data were generated, and have recently been criticised for allowing infinite flexibility in the models. To explore and test the need of between-trial variability parameters we develop a simple sequential sampling model of N-choice speeded decision making: the racing diffusion model. The model makes speeded decisions from a race of evidence accumulators that integrate information in a noisy fashion within a trial. The racing diffusion does not assume that any evidence accumulation process varies between trial, and so, the model provides alternative explanations of key response time phenomena, such as fast and slow error response times relative to correct response times. Overall, our paper gives good reason to rethink including between-trial variability parameters in sequential sampling models. © 2020, The Psychonomic Society, Inc.
- Authors: Tillman, Gabriel , Van Zandt, Trish , Logan, Gordon
- Date: 2020
- Type: Text , Journal article , Review
- Relation: Psychonomic Bulletin and Review Vol. 27, no. 5 (2020), p. 911-936
- Full Text:
- Reviewed:
- Description: Most current sequential sampling models have random between-trial variability in their parameters. These sources of variability make the models more complex in order to fit response time data, do not provide any further explanation to how the data were generated, and have recently been criticised for allowing infinite flexibility in the models. To explore and test the need of between-trial variability parameters we develop a simple sequential sampling model of N-choice speeded decision making: the racing diffusion model. The model makes speeded decisions from a race of evidence accumulators that integrate information in a noisy fashion within a trial. The racing diffusion does not assume that any evidence accumulation process varies between trial, and so, the model provides alternative explanations of key response time phenomena, such as fast and slow error response times relative to correct response times. Overall, our paper gives good reason to rethink including between-trial variability parameters in sequential sampling models. © 2020, The Psychonomic Society, Inc.
Reusing artifact-centric business process models : a behavioral consistent specialization approach
- Yongchareon, Sira, Liu, Chengfei, Zhao, Xiaohui
- Authors: Yongchareon, Sira , Liu, Chengfei , Zhao, Xiaohui
- Date: 2020
- Type: Text , Journal article
- Relation: Computing Vol. 102, no. 8 (2020), p. 1843-1879
- Full Text:
- Reviewed:
- Description: Process reuse is one of the important research areas that address efficiency issues in business process modeling. Similar to software reuse, business processes should be able to be componentized and specialized in order to enable flexible process expansion and customization. Current activity/control-flow centric workflow modeling approaches face difficulty in supporting highly flexible process reuse, limited by their procedural nature. In comparison, the emerging artifact-centric workflow modeling approach well fits into these reuse requirements. Beyond the classic class level reuse in existing object-oriented approaches, process reuse faces the challenge of handling synchronization dependencies among artifact lifecycles as parts of a business process. In this article, we propose a theoretical framework for business process specialization that comprises an artifact-centric business process model, a set of methods to design and construct a specialized business process model from a base model, and a set of behavioral consistency criteria to help check the consistency between the two process models. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature.
- Authors: Yongchareon, Sira , Liu, Chengfei , Zhao, Xiaohui
- Date: 2020
- Type: Text , Journal article
- Relation: Computing Vol. 102, no. 8 (2020), p. 1843-1879
- Full Text:
- Reviewed:
- Description: Process reuse is one of the important research areas that address efficiency issues in business process modeling. Similar to software reuse, business processes should be able to be componentized and specialized in order to enable flexible process expansion and customization. Current activity/control-flow centric workflow modeling approaches face difficulty in supporting highly flexible process reuse, limited by their procedural nature. In comparison, the emerging artifact-centric workflow modeling approach well fits into these reuse requirements. Beyond the classic class level reuse in existing object-oriented approaches, process reuse faces the challenge of handling synchronization dependencies among artifact lifecycles as parts of a business process. In this article, we propose a theoretical framework for business process specialization that comprises an artifact-centric business process model, a set of methods to design and construct a specialized business process model from a base model, and a set of behavioral consistency criteria to help check the consistency between the two process models. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature.
The radius of metric subregularity
- Dontchev, Asen, Gfrerer, Helmut, Kruger, Alexander, Outrata, Jiri
- Authors: Dontchev, Asen , Gfrerer, Helmut , Kruger, Alexander , Outrata, Jiri
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 3 (2020), p. 451-473, http://purl.org/au-research/grants/arc/DP160100854
- Full Text:
- Reviewed:
- Description: There is a basic paradigm, called here the radius of well-posedness, which quantifies the “distance” from a given well-posed problem to the set of ill-posed problems of the same kind. In variational analysis, well-posedness is often understood as a regularity property, which is usually employed to measure the effect of perturbations and approximations of a problem on its solutions. In this paper we focus on evaluating the radius of the property of metric subregularity which, in contrast to its siblings, metric regularity, strong regularity and strong subregularity, exhibits a more complicated behavior under various perturbations. We consider three kinds of perturbations: by Lipschitz continuous functions, by semismooth functions, and by smooth functions, obtaining different expressions/bounds for the radius of subregularity, which involve generalized derivatives of set-valued mappings. We also obtain different expressions when using either Frobenius or Euclidean norm to measure the radius. As an application, we evaluate the radius of subregularity of a general constraint system. Examples illustrate the theoretical findings. © 2019, Springer Nature B.V.
- Description: Funding details: Austrian Science Fund, FWF, P26132-N25, P26640-N25, P29190-N32 Funding details: National Science Foundation, NSF Funding details: Australian Research Council, ARC Funding details: Australian Research Council, ARC, DP160100854 Funding details: Austrian Science Fund, FWF Funding details: Universiteit Stellenbosch, US, P26640-N25 P26132-N25, BodyRef/PDF/11228_2019_Article_523.pdf Funding details: Grantová Agentura
- Authors: Dontchev, Asen , Gfrerer, Helmut , Kruger, Alexander , Outrata, Jiri
- Date: 2020
- Type: Text , Journal article
- Relation: Set-Valued and Variational Analysis Vol. 28, no. 3 (2020), p. 451-473, http://purl.org/au-research/grants/arc/DP160100854
- Full Text:
- Reviewed:
- Description: There is a basic paradigm, called here the radius of well-posedness, which quantifies the “distance” from a given well-posed problem to the set of ill-posed problems of the same kind. In variational analysis, well-posedness is often understood as a regularity property, which is usually employed to measure the effect of perturbations and approximations of a problem on its solutions. In this paper we focus on evaluating the radius of the property of metric subregularity which, in contrast to its siblings, metric regularity, strong regularity and strong subregularity, exhibits a more complicated behavior under various perturbations. We consider three kinds of perturbations: by Lipschitz continuous functions, by semismooth functions, and by smooth functions, obtaining different expressions/bounds for the radius of subregularity, which involve generalized derivatives of set-valued mappings. We also obtain different expressions when using either Frobenius or Euclidean norm to measure the radius. As an application, we evaluate the radius of subregularity of a general constraint system. Examples illustrate the theoretical findings. © 2019, Springer Nature B.V.
- Description: Funding details: Austrian Science Fund, FWF, P26132-N25, P26640-N25, P29190-N32 Funding details: National Science Foundation, NSF Funding details: Australian Research Council, ARC Funding details: Australian Research Council, ARC, DP160100854 Funding details: Austrian Science Fund, FWF Funding details: Universiteit Stellenbosch, US, P26640-N25 P26132-N25, BodyRef/PDF/11228_2019_Article_523.pdf Funding details: Grantová Agentura
Subdifferential of the supremum via compactification of the index set
- Correa, Rafael, Hantoute, Abderrahim, López, Marco
- Authors: Correa, Rafael , Hantoute, Abderrahim , López, Marco
- Date: 2020
- Type: Text , Journal article
- Relation: Vietnam Journal of Mathematics Vol. 48, no. 3 (2020), p. 569-588, http://purl.org/au-research/grants/arc/DP180100602
- Full Text:
- Reviewed:
- Description: We give new characterizations for the subdifferential of the supremum of an arbitrary family of convex functions, dropping out the standard assumptions of compactness of the index set and upper semi-continuity of the functions with respect to the index (J. Convex Anal. 26, 299–324, 2019). We develop an approach based on the compactification of the index set, giving rise to an appropriate enlargement of the original family. Moreover, in contrast to the previous results in the literature, our characterizations are formulated exclusively in terms of exact subdifferentials at the nominal point. Fritz–John and KKT conditions are derived for convex semi-infinite programming. © 2020, Vietnam Academy of Science and Technology (VAST) and Springer Nature Singapore Pte Ltd.
- Description: Funding details: Fondo Nacional de Desarrollo CientÃfico, Tecnológico y de Innovación Tecnológica, FONDECYT, PIA AFB-170001, 1190110, 1190012 Funding details: Universidad de Alicante, BEA- GAL 18/00205, PGC2018-097960-B-C21 Funding details: Australian Research Council, ARC, DP 180100602 Funding details: Comisión Nacional de Investigación CientÃfica y Tecnológica, CONICYT Funding details: Ministerio de Ciencia e Innovación, MICINN Funding text 1: Research supported by CONICYT (Fondecyt 1190012 and 1190110), Proyecto/Grant PIA AFB-170001, MICIU of Spain and Universidad de Alicante (Grant Beatriz Galindo BEA- GAL 18/00205), and Research Project PGC2018-097960-B-C21 from MICINN, Spain. The research of the third author is also supported by the Australian ARC - Discovery Projects DP 180100602
- Authors: Correa, Rafael , Hantoute, Abderrahim , López, Marco
- Date: 2020
- Type: Text , Journal article
- Relation: Vietnam Journal of Mathematics Vol. 48, no. 3 (2020), p. 569-588, http://purl.org/au-research/grants/arc/DP180100602
- Full Text:
- Reviewed:
- Description: We give new characterizations for the subdifferential of the supremum of an arbitrary family of convex functions, dropping out the standard assumptions of compactness of the index set and upper semi-continuity of the functions with respect to the index (J. Convex Anal. 26, 299–324, 2019). We develop an approach based on the compactification of the index set, giving rise to an appropriate enlargement of the original family. Moreover, in contrast to the previous results in the literature, our characterizations are formulated exclusively in terms of exact subdifferentials at the nominal point. Fritz–John and KKT conditions are derived for convex semi-infinite programming. © 2020, Vietnam Academy of Science and Technology (VAST) and Springer Nature Singapore Pte Ltd.
- Description: Funding details: Fondo Nacional de Desarrollo CientÃfico, Tecnológico y de Innovación Tecnológica, FONDECYT, PIA AFB-170001, 1190110, 1190012 Funding details: Universidad de Alicante, BEA- GAL 18/00205, PGC2018-097960-B-C21 Funding details: Australian Research Council, ARC, DP 180100602 Funding details: Comisión Nacional de Investigación CientÃfica y Tecnológica, CONICYT Funding details: Ministerio de Ciencia e Innovación, MICINN Funding text 1: Research supported by CONICYT (Fondecyt 1190012 and 1190110), Proyecto/Grant PIA AFB-170001, MICIU of Spain and Universidad de Alicante (Grant Beatriz Galindo BEA- GAL 18/00205), and Research Project PGC2018-097960-B-C21 from MICINN, Spain. The research of the third author is also supported by the Australian ARC - Discovery Projects DP 180100602
Geometric and metric characterizations of transversality properties
- Bui, Hoa, Cuong, Nguyen, Kruger, Alexander
- Authors: Bui, Hoa , Cuong, Nguyen , Kruger, Alexander
- Date: 2020
- Type: Text , Journal article
- Relation: Vietnam Journal of Mathematics Vol. 48, no. 2 (2020), p. 277-297
- Full Text:
- Reviewed:
- Description: This paper continues the study of ‘good arrangements’ of collections of sets near a point in their intersection. We clarify quantitative relations between several geometric and metric characterizations of the transversality properties of collections of sets and the corresponding regularity properties of set-valued mappings. We expose all the parameters involved in the definitions and characterizations and establish relations between them. This allows us to classify the quantitative geometric and metric characterizations of transversality and regularity, and subdivide them into two groups with complete exact equivalences between the parameters within each group and clear relations between the values of the parameters in different groups. © 2020, Vietnam Academy of Science and Technology (VAST) and Springer Nature Singapore Pte Ltd.
- Authors: Bui, Hoa , Cuong, Nguyen , Kruger, Alexander
- Date: 2020
- Type: Text , Journal article
- Relation: Vietnam Journal of Mathematics Vol. 48, no. 2 (2020), p. 277-297
- Full Text:
- Reviewed:
- Description: This paper continues the study of ‘good arrangements’ of collections of sets near a point in their intersection. We clarify quantitative relations between several geometric and metric characterizations of the transversality properties of collections of sets and the corresponding regularity properties of set-valued mappings. We expose all the parameters involved in the definitions and characterizations and establish relations between them. This allows us to classify the quantitative geometric and metric characterizations of transversality and regularity, and subdivide them into two groups with complete exact equivalences between the parameters within each group and clear relations between the values of the parameters in different groups. © 2020, Vietnam Academy of Science and Technology (VAST) and Springer Nature Singapore Pte Ltd.
Inattention and disordered gaming : does culture matter?
- Stavropoulos, Vasileios, Baynes, Kyi, O’Farrel, Dominic, Gomez, Rapson, Mueller, Astrid, Yucel, Murat, Griffiths, Mark
- Authors: Stavropoulos, Vasileios , Baynes, Kyi , O’Farrel, Dominic , Gomez, Rapson , Mueller, Astrid , Yucel, Murat , Griffiths, Mark
- Date: 2020
- Type: Text , Journal article
- Relation: Psychiatric Quarterly Vol. 91, no. 2 (2020), p. 333-348
- Full Text:
- Reviewed:
- Description: Problematic gaming has emerged as a contemporary concern, leading to the introduction of the diagnostic term ‘Internet Gaming Disorder’ (IGD; American Psychiatric Association). The present study aims to empirically assess the association between inattention and IGD, in the light of variable levels of vertical-individualism that reflects cultural inclinations towards independence, competitiveness, and hierarchy. The participants (N = 1032) comprised a normative cohort of Massively Multiplayer Online (MMO) gamers (Mage = 24 years; 48.7% male). IGD was measured with the nine-item short-form IGD Scale (IGD9-SF), inattention with the Attention Deficit Hyperactivity Disorder (ADHD) Self-Report Scale, and vertical individualism with the Individualism-Collectivism Questionnaire. Complex hierarchical and moderated regressions were employed. Findings demonstrated an association between IGD and inattention, and additionally showed that this association was exacerbated by a more vertically-individualistic cultural orientation without significant gender differences. The need of differentially addressing IGD risk among inattentive gamers of diverse cultural orientation is highlighted. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
- Authors: Stavropoulos, Vasileios , Baynes, Kyi , O’Farrel, Dominic , Gomez, Rapson , Mueller, Astrid , Yucel, Murat , Griffiths, Mark
- Date: 2020
- Type: Text , Journal article
- Relation: Psychiatric Quarterly Vol. 91, no. 2 (2020), p. 333-348
- Full Text:
- Reviewed:
- Description: Problematic gaming has emerged as a contemporary concern, leading to the introduction of the diagnostic term ‘Internet Gaming Disorder’ (IGD; American Psychiatric Association). The present study aims to empirically assess the association between inattention and IGD, in the light of variable levels of vertical-individualism that reflects cultural inclinations towards independence, competitiveness, and hierarchy. The participants (N = 1032) comprised a normative cohort of Massively Multiplayer Online (MMO) gamers (Mage = 24 years; 48.7% male). IGD was measured with the nine-item short-form IGD Scale (IGD9-SF), inattention with the Attention Deficit Hyperactivity Disorder (ADHD) Self-Report Scale, and vertical individualism with the Individualism-Collectivism Questionnaire. Complex hierarchical and moderated regressions were employed. Findings demonstrated an association between IGD and inattention, and additionally showed that this association was exacerbated by a more vertically-individualistic cultural orientation without significant gender differences. The need of differentially addressing IGD risk among inattentive gamers of diverse cultural orientation is highlighted. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
Test-retest measurement invariance of the nine-item internet gaming disorder scale in two countries : a preliminary longitudinal study
- Stavropoulos, Vasileios, Bamford, Luke, Beard, Charlotte, Gomez, Rapson, Griffiths, Mark
- Authors: Stavropoulos, Vasileios , Bamford, Luke , Beard, Charlotte , Gomez, Rapson , Griffiths, Mark
- Date: 2021
- Type: Text , Journal article
- Relation: International Journal of Mental Health and Addiction Vol. 19, no. 6 (2021), p. 2003-2020
- Full Text:
- Reviewed:
- Description: The reliable longitudinal assessment of Internet Gaming Disorder (IGD) behaviors is viewed by many as a pivotal clinical and research priority. The present study is the first to examine the test-retest measurement invariance of IGD ratings, as assessed using the short-form nine-item Internet Gaming Disorder Scale (IGDS9-SF) over an approximate period of 3 months, across two normative national samples. Differences referring to the mode of the data collection (face-to-face [FtF] vs. online) were also considered. Two sequences of successive multiple group confirmatory factor analyses (CFAs) were calculated to longitudinally assess the psychometric properties of the IGDS9-SF using emergent adults, gamers from (i) the United States of America (USA; N = 120, 18–29 years, Meanage = 22.35, 51.6% male) assessed online and; and (ii) Australia (N = 61, 18–31 years, Meanage = 23.02, 75.4% male) assessed FtF. Configural invariance was established across both samples, and metric and scalar invariances were supported for the USA sample. Interestingly, only partial metric (factor loadings for Items 2 and 3 non-invariant) and partial scalar invariance (i.e., all thresholds of Items 1 and 2, and thresholds 1, 3, for Items 4, 6, 8, and 9 non-invariant) were established for the Australian sample. Findings are discussed in the light of using IGDS9-SF to assess and monitor IGD behaviors over time in both in clinical and non-clinical settings. © 2019, The Author(s).
- Authors: Stavropoulos, Vasileios , Bamford, Luke , Beard, Charlotte , Gomez, Rapson , Griffiths, Mark
- Date: 2021
- Type: Text , Journal article
- Relation: International Journal of Mental Health and Addiction Vol. 19, no. 6 (2021), p. 2003-2020
- Full Text:
- Reviewed:
- Description: The reliable longitudinal assessment of Internet Gaming Disorder (IGD) behaviors is viewed by many as a pivotal clinical and research priority. The present study is the first to examine the test-retest measurement invariance of IGD ratings, as assessed using the short-form nine-item Internet Gaming Disorder Scale (IGDS9-SF) over an approximate period of 3 months, across two normative national samples. Differences referring to the mode of the data collection (face-to-face [FtF] vs. online) were also considered. Two sequences of successive multiple group confirmatory factor analyses (CFAs) were calculated to longitudinally assess the psychometric properties of the IGDS9-SF using emergent adults, gamers from (i) the United States of America (USA; N = 120, 18–29 years, Meanage = 22.35, 51.6% male) assessed online and; and (ii) Australia (N = 61, 18–31 years, Meanage = 23.02, 75.4% male) assessed FtF. Configural invariance was established across both samples, and metric and scalar invariances were supported for the USA sample. Interestingly, only partial metric (factor loadings for Items 2 and 3 non-invariant) and partial scalar invariance (i.e., all thresholds of Items 1 and 2, and thresholds 1, 3, for Items 4, 6, 8, and 9 non-invariant) were established for the Australian sample. Findings are discussed in the light of using IGDS9-SF to assess and monitor IGD behaviors over time in both in clinical and non-clinical settings. © 2019, The Author(s).
Thermal fragmentation as a possible, viable, alternative mining method in narrow vein mining?
- Bouwmeester, Patrick, Tuck, Michael, Koroznikova, Larissa, Durkin, Steve
- Authors: Bouwmeester, Patrick , Tuck, Michael , Koroznikova, Larissa , Durkin, Steve
- Date: 2020
- Type: Text , Journal article
- Relation: Mining, Metallurgy and Exploration Vol. 37, no. 2 (2020), p. 605-618
- Full Text:
- Reviewed:
- Description: In currently used mining methods, blasting techniques often causes dilution of valuable ore and results in costly processing requirements. In the context of narrow vein mining of thin and highly concentrated orebodies there is a need of a mining method that can reduce dilution in order to remain economically viable. This research project explored the viability of a new mining technology, thermal fragmentation, in narrow vein mining. Thermal fragmentation technology uses a flame jet to produce extreme heat that spalls the surrounding rock to a strategically located drill hole, as an alternative to traditional blasting. This paper creates a net present value (NPV) model of a mining method using thermal fragmentation, as well as for an existing method used for narrow vein mining; comparisons and evaluations were made regarding the feasibility of the new technology. It was found that while overall costs for thermal fragmentation were relatively high, reductions in wages, haulage and processing costs, as well as increased productivity and ore recovery, meant that the new method would improve the financial performance of any operation. These results identify that there is an opportunity to introduce the thermal fragmentation technology to narrow vein mines within Australia, in order to lower costs and increase profit. © 2019, Society for Mining, Metallurgy & Exploration Inc.
- Authors: Bouwmeester, Patrick , Tuck, Michael , Koroznikova, Larissa , Durkin, Steve
- Date: 2020
- Type: Text , Journal article
- Relation: Mining, Metallurgy and Exploration Vol. 37, no. 2 (2020), p. 605-618
- Full Text:
- Reviewed:
- Description: In currently used mining methods, blasting techniques often causes dilution of valuable ore and results in costly processing requirements. In the context of narrow vein mining of thin and highly concentrated orebodies there is a need of a mining method that can reduce dilution in order to remain economically viable. This research project explored the viability of a new mining technology, thermal fragmentation, in narrow vein mining. Thermal fragmentation technology uses a flame jet to produce extreme heat that spalls the surrounding rock to a strategically located drill hole, as an alternative to traditional blasting. This paper creates a net present value (NPV) model of a mining method using thermal fragmentation, as well as for an existing method used for narrow vein mining; comparisons and evaluations were made regarding the feasibility of the new technology. It was found that while overall costs for thermal fragmentation were relatively high, reductions in wages, haulage and processing costs, as well as increased productivity and ore recovery, meant that the new method would improve the financial performance of any operation. These results identify that there is an opportunity to introduce the thermal fragmentation technology to narrow vein mines within Australia, in order to lower costs and increase profit. © 2019, Society for Mining, Metallurgy & Exploration Inc.