Article
Multidisciplinary Sciences
Ampol Duangpan, Ratinan Boonklurb, Kittisak Chumpong, Phiraphat Sutthimat
Summary: This paper proposes a simple and novel approach to establish analytical formulas for conditional and mixed moments of the Jacobi process. The approach involves solving a partial differential equation and includes random fluctuations with an asymmetric Wiener process.
Article
Mathematics
David Payares-Garcia, Javier Platero, Jorge Mateu
Summary: The analysis of emergency calls' spatial and temporal characteristics is crucial for understanding and mitigating distress situations. This study proposes a modelling strategy that accounts for the complex dynamics of crime-related emergency calls in an urban environment. By analyzing data from Valencia, Spain, for ten years, the study aims to forecast the spatio-temporal behavior of emergency calls and guide mitigation strategies and policy.
Article
Mathematics, Applied
Chunyin Jin, Shuangzhi Li
Summary: In this paper, the flocking behavior of a locally interacting multi-agent system with a unit speed constraint is studied. By utilizing the spectral gap of a connected stochastic matrix and estimating perturbations of a linearized system, a sufficient condition is obtained that guarantees flocking based only on initial data and model parameters. It is further shown that the system achieves a consensus at an exponential rate.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mathematics
Serena Brianzoni, Giovanni Campisi, Graziella Pacelli
Summary: This paper presents a discrete-time version of a continuous-time model with fundamentalists and momentum traders. The impact of cross-sectional momentum traders on the dynamics of the model is studied. The benchmark model is transformed from continuous to discrete time using sophisticated discretization techniques. The resulting discrete-time system retains the dynamic properties of the continuous-time original model and generates erratic time series similar to real markets.
Article
Education & Educational Research
Ha Nguyen
Summary: This study explores the interactions of two text-based agents playing the roles of an expert and a less knowledgeable peer in a high school marine biology lesson. The results show that there were no differences in the frequency of discussion moves between the two agents. Interestingly, the less knowledgeable peer agent prompted groups to question and build on others' ideas, while the expert agent led to student-teacher exchanges where groups responded to the agent's nudges and provided reasoning.
BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY
(2022)
Article
Mathematics, Applied
Young-Ho Kim
Summary: The main purpose of this paper is to demonstrate the moment inequality theorems in stochastic processes. Specifically, the paper aims to establish stochastic moment inequalities using the Ito formula and the Gronwall-type inequalities. It also introduces new proofs for some parts of the Burkholder-Davis-Gundy inequality and derivation of the inverse inequality.
JOURNAL OF MATHEMATICAL INEQUALITIES
(2022)
Article
Thermodynamics
Jingxian Yang, Junyong Liu, Gao Qiu, Jichun Liu, Shafqat Jawad, Shuai Zhang
Summary: Integrated power systems (IPS) have the potential to solve the energy discrepancy by incorporating multiple renewable sources. However, the dispatch of hydro-photovoltaic-pumped hydro storage (Hydro-PV-PHS) IPS still struggles with low clean energy utilization rates due to limited mainstreams and complex mountainous meteorology. To address this issue, a spatio-temporality-enabled parallel multi-agent-based dynamic dispatch method is proposed, incorporating real-time measurements, Markov decision processes, and neural network agents. The results of numerical studies demonstrate that this method enables real-time and near-optimal dynamic dispatch for IPS, outperforming other approaches in terms of adaptability, robustness, and efficiency.
Article
Environmental Studies
Yajuan Wang, Xi Wu, Hongbo Zhu
Summary: This study estimated the cultivated land use efficiency of 342 prefecture-level administrative regions in China from 2003 to 2019 based on the stochastic frontier production function. The results showed that although the overall efficiency of cultivated land use has improved, the overall level remains low. The study also found a multi-core structure of high efficiency in the south and low efficiency in the north, high efficiency in the east and low efficiency in the west in urban areas of China.
Article
Chemistry, Applied
Lei Zhou, Jiefei Zhang, Xiangning Liu, Hao Wu, Qian Guan, Guisheng Zeng, Linjun Yang
Summary: Fine particles emitted from coal-fired power plants are a major contributor to air pollution and health issues in China. Chemical agglomeration technology, which promotes the formation of larger particle aggregates, can improve the capture of fine particles by electrostatic precipitators. Experimental results showed that the addition of sesbania gum and styrene-butadiene emulsion significantly increased the concentration and particle size of fly ash particles, leading to higher dust removal efficiency. Furthermore, the use of a surfactant called T-100 further improved the removal efficiency and wetting performance.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Engineering, Chemical
Hyun-Seung Nam, Yonghwan Kim
Summary: This paper introduces a semi-analytic method to predict the deck-slamming probability and corresponding loads, which takes into account the linear and second-order components of the relative wave elevation using a nonlinear statistical approach and the Hermite-moment method. The method is applied to a tension leg platform (TLP) model, revealing the impact of the second-order component of the relative wave elevation on deck slamming.
Article
Chemistry, Analytical
Sheng-Song Li, Yong-Chao Zheng, Xiao-Ming Zhu, Hong-Bo Wang, Long-Hui Liang, Xu-Zhe Wang, Ling Yuan, Fa-Heng Zhang, He Zheng, Chong-Lin Zhao
Summary: A fluorescent BODIPY probe was designed and synthesized for highly sensitive and selective detection of DCNP, showing significant fluorescence quenching in the presence of Et3N and a 30-fold fluorescence enhancement in the presence of DCNP. The fluorescence variations were attributed to intramolecular photo-induced electron transfer process, with a low limit of detection (34 nM) and rapid response (t1/2 = 175 s). Naked-eye detection of DCNP was also achieved in both liquid and vapor phases using test strips immobilized with the probe.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Automation & Control Systems
Chengbo Yi, Jianwen Feng, Chen Xu, Jingyi Wang, Yi Zhao
Summary: This study focuses on the mean square consensus problem for stochastic multi-agent systems with nonlinear protocols, proposing a novel proposition based on matrix theory to overcome challenges, and exploring time-dependent event-triggered strategies for communication efficiency. Sufficient conditions for mean square consensus with state-dependent topology are established, eliminating Zeno phenomenon with a positive lower bound for inter-event times. A simulation example demonstrates the validity of theoretical results and effectiveness of the control protocol.
INTERNATIONAL JOURNAL OF CONTROL
(2021)
Article
Engineering, Environmental
Katarzyna Burdzy, Yongming Ju, Dorota Kolodynska
Summary: The need for recycling used materials has become urgent due to environmental pollution and the depletion of many deposits. This paper presents a study on the use of a biodegradable complexing agent (IDHA) for the recovery of La(III), Nd(III), and Ho(III) through adsorption using different ion exchangers. The results show that Purolite S957 has the highest adsorption capacity for La(III) complexes, while Lewatit SP112 exhibits high efficiency in adsorbing Nd(III) and Ho(III) complexes.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Mathematics, Applied
Hamdy M. Ahmed
Summary: This paper investigates the control conditions of noninstantaneous impulsive conformable fractional stochastic delay integro-differential system driven by Rosenblatt process, and provides an explanation through an example.
QUALITATIVE THEORY OF DYNAMICAL SYSTEMS
(2022)
Article
Materials Science, Ceramics
Pravallika Banoth, Arya Sohan, Chinna Kandula, Pratap Kollu
Summary: In this study, multiferroic BiFeO3 (BFO) was synthesized using the solvothermal technique with Hexa-methylenetetramine (HMTA) as a precipitating agent. The optimization of HMTA concentration allowed for the synthesis of pure phase BFO in a short reaction time. The characterization of structural, magnetic, ferroelectric, dielectric, and optical properties confirmed the significance of HMTA in the solvothermal synthesis method.
CERAMICS INTERNATIONAL
(2022)
Article
Biodiversity Conservation
Camilla Novaglio, Julia L. Blanchard, Michael J. Plank, Elizabeth Putten, Asta Audzijonyte, Javier Porobic, Elizabeth A. Fulton
Summary: Ecosystem-based fisheries management aims to ensure sustainability while maximizing socio-economic benefits. Examining the effects of different management strategies on mixed fisheries, the study found that specialized fleets are more likely to achieve optimal outcomes under single species management, highlighting the importance of considering fleet interactions in evaluating management strategies.
JOURNAL OF APPLIED ECOLOGY
(2022)
Article
Multidisciplinary Sciences
Nicholas Steyn, Michael J. Plank, Rachelle N. Binny, Shaun C. Hendy, Audrey Lustig, Kannan Ridings
Summary: This article develops a mathematical model to estimate the impact of New Zealand's vaccine rollout on the potential spread and health impacts of COVID-19. The study aims to provide policy advice on border restrictions and control measures during the vaccination roll-out. The model finds that reaching the population immunity threshold would require close to 100% vaccination coverage, but achieving such coverage is unlikely. Relaxing controls completely would risk serious health impacts, but higher vaccine coverage would provide collective protection and make it easier to control outbreaks.
SCIENTIFIC REPORTS
(2022)
Article
Ecology
Nao Takashina, Michael J. Plank, Clinton N. Jenkins, Evan P. Economo
Summary: The species-range size distribution is influenced by speciation, transformation of range sizes, and extinction. A mathematical framework called the gain-loss-allopatric speciation model was developed to integrate these processes and predict species richness dynamics. The model was fitted to empirical data of birds, mammals, and beetles, providing insights into the formation of range-size distributions.
ECOLOGY AND EVOLUTION
(2022)
Article
Economics
Shaun C. Hendy, Siouxsie Wiles, Rachelle Binny, Michael J. Plank
Summary: This article questions Gibson's analysis and points out the problems in his research. He neglects the spatio-temporal heterogeneity in the spread of COVID-19 in the United States, selects arbitrary cross-sectional data, and chooses an instrument variable that may be correlated with the explanatory variable, introducing bias.
NEW ZEALAND ECONOMIC PAPERS
(2022)
Article
Biology
Michael J. Plank, Alex James, Audrey Lustig, Nicholas Steyn, Rachelle N. Binny, Shaun C. Hendy
Summary: This study uses a branching process model to evaluate the potential of manual contact tracing and digital tracing systems in controlling the COVID-19 epidemic. The results show that effective manual contact tracing can reduce the reproduction number, and adding a digital tracing system with a high uptake rate can further decrease the reproduction number. Close collaboration with public health agencies is crucial for the significant contribution of digital tracing systems in epidemic control.
MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA
(2022)
Article
Immunology
Rachelle N. Binny, Patricia Priest, Nigel P. French, Matthew Parry, Audrey Lustig, Shaun C. Hendy, Oliver J. Maclaren, Kannan M. Ridings, Nicholas Steyn, Giorgia Vattiato, Michael J. Plank
Summary: Reverse transcription PCR remains a sensitive technique for detecting SARS-CoV-2 infection and has played an important role in controlling the COVID-19 pandemic in New Zealand. Sensitivity peaks 4-5 days postinfection and remains above 88% between 5 and 14 days postinfection. Vaccinated individuals, females, those under 40, and Pacific peoples exhibit a more rapid decline in sensitivity.
JOURNAL OF INFECTIOUS DISEASES
(2022)
Article
Biology
Michael J. Plank
Summary: Countries like New Zealand, Australia, and Taiwan have adopted an elimination strategy to combat the Covid-19 pandemic by implementing strict border controls and rapidly responding to eliminate border-related re-introductions. Decision-makers face the challenge of determining the appropriate threshold for implementing strict control measures when a re-introduction occurs. This study uses a highly idealized model to identify factors that impact the choice of threshold and minimize the duration of control measures.
MATHEMATICAL BIOSCIENCES
(2022)
Article
Multidisciplinary Sciences
Rachelle N. Binny, Audrey Lustig, Shaun C. Hendy, Oliver J. Maclaren, Kannan M. Ridings, Giorgia Vattiato, Michael J. Plank
Summary: Real-time estimation of the effective reproduction number during the Delta variant outbreak in New Zealand provides valuable insights for decision makers. The study highlights the impact of non-pharmaceutical interventions and vaccination coverage on transmission dynamics, and emphasizes the effectiveness of strict restrictions and increasing vaccination coverage in controlling the outbreak.
Article
Fisheries
Richard Law, Michael J. Plank
Summary: This paper proposes that appropriately scaled fishing could help maintain biodiversity and protect rarer species, while allowing some exploitation of species with greater production. Based on a dynamic model of a marine ecosystem, numerical evidence is provided to support this idea.
FISH AND FISHERIES
(2023)
Article
Infectious Diseases
Giorgia Vattiatio, Audrey Lustig, Oliver J. Maclaren, Michael J. Plank
Summary: New Zealand experienced a wave of the Omicron variant of SARS-CoV-2 in 2022, with a projected second wave in the second half of the year. Peak hospital occupancy and daily infections were generally lower in the second wave, influenced by the speed of waning and age distribution of infections. Scenarios with higher transmission did not always lead to higher peaks, but resulted in more sustained healthcare demand. The health burden of Covid-19 in the medium term is sensitive to the strength and durability of immunity against reinfection, which is uncertain.
Review
Ecology
Giorgia Vattiato, Rachelle N. Binny, Sam J. Davidson, Andrea E. Byrom, Dean P. Anderson, Michael J. Plank, Joanna K. Carpenter, Alex James
Summary: Management of invasive mammal pests is crucial for the conservation of New Zealand's native flora and fauna. This paper reviews studies on spatial detectability parameters of ten invasive mammal pests in New Zealand, considering factors such as habitat, season, and surveillance device type. The findings highlight the variation in detectability under different conditions and identify knowledge gaps for future research.
NEW ZEALAND JOURNAL OF ECOLOGY
(2023)
Article
Mathematics, Applied
James m. Mccaw, Michael j. Plank
Summary: This article provides an overview of how mathematical modelling and data analytics have supported the policy response to the COVID-19 pandemic in Australia and New Zealand. It discusses various model outputs used in different contexts and the communication issues between modellers and stakeholders. The article concludes with future challenges and opportunities in this area.
Article
Mathematical & Computational Biology
Giorgia Vattiato, Oliver Maclaren, Audrey Lustig, Rachelle N. Binny, Shaun C. Hendy, Michael J. Plank
Summary: New Zealand delayed the introduction of the Omicron variant by using strict border controls and took advantage of the time to increase vaccination rates and roll out booster doses. A mathematical model was used to assess the potential impact of an Omicron wave, and it was found that an accelerated booster programme combined with public health measures is crucial to avoid overwhelming the healthcare system.
INFECTIOUS DISEASE MODELLING
(2022)
Article
Multidisciplinary Sciences
Jonah J. Klowss, Alexander P. Browning, Ryan J. Murphy, Elliot J. Carr, Michael J. Plank, Gency Gunasingh, Nikolas K. Haass, Matthew J. Simpson
Summary: In vitro tumour spheroids have been widely used in studying avascular tumour growth and drug design. The recent development of real-time fluorescent cell cycle imaging enables the monitoring of individual cells within the spheroid, leading to the concept of a four-dimensional tumour spheroid.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2022)
Article
Mathematical & Computational Biology
Nicholas Steyn, Audrey Lustig, Shaun C. Hendy, Rachelle N. Binny, Michael J. Plank
Summary: Combining testing and home isolation strategies can significantly reduce the risk of community outbreaks caused by infectious travellers; in certain circumstances, using daily lateral flow tests or a combination of lateral flow tests and PCR tests can reduce the risk to a comparable or lower level; controlling the number of travellers from countries with high COVID-19 prevalence helps manage the risk of COVID-19 at the border.
INFECTIOUS DISEASE MODELLING
(2022)