Second-order Neighbours Research Articles

Health map for HealthGap: Defining a geographical catchment to examine cardiovascular risk in Victoria, Australia

The HealthGap study aimed to understand cardiovascular risk among Indigenous Australians in Victoria using linked administrative data. A key challenge was differing spatial coverages of sources: state-level data for risk factors but cardiovascular outcomes for three hospitals. Catchments were defined based on hospital postcodes to estimate denominator populations for risk modelling: first- and second-order neighbours, and spatial distribution of outcomes (‘spatial event distribution’). Catchment coverage was assessed through proportions of patients presenting to study hospitals from catchment postcodes. The spatial event distribution performed best, capturing 82% events overall (first-order:40%; second-order:64%) and 65% Indigenous (27% and 45%). No approach excluded proximal non-study hospitals. Spatial event distributions could help define denominator populations when geographic information on outcome data is available but may not avoid potential misclassification.

Spatial spillover effect of the enterprise sector on local residents’ income in Vietnam

AbstractThis study uses a panel data set from all 63 provinces in Vietnam and spatial regression models to investigate the spatial spillover effect of the enterprise sector on local residents’ income. The results show that expanding the enterprise sector can directly and indirectly increase local income. Although this spillover effect is positive and significant, it is smaller than the direct effect and gradually diminishes when the distance between provinces increases. For example, the estimation results applying the spatial Durbin model holding other variables constant show that a 10% increase in the enterprise capital volume in Ho Chi Minh City can raise local total income in this city, and first- and second-order neighbours by 0.53%, 0.22%, and 0.17%, respectively. This study provides novel evidence on the spatial spillover effect of the enterprise sector on local incomes using spatial econometric models. The findings offer valuable information for policymakers in planning enterprise sector development to improve local residents’ income in Vietnam.

Consensus of general linear multi-agent systems based on second-order neighbours' information: directed topology case

For a general linear multi-agent system (MAS) with directed communication topology, based on second-order neighbours' information, we establish its consensus criteria under intermittent control, which is more difficult to study due to the fact that the Laplacian matrix corresponding to the directed topology is an asymmetric matrix. In our study, both the weights of first-order and second-order neighbours need to be designed as parameters. Using switched system theory and Lyapunov function method, we prove that the intermittent control protocol based on second-order neighbours' information can make MASs achieve consensus faster than the common intermittent control protocol under certain conditions. Furthermore, we extend the results from MASs without leader to MASs with leader. Finally, numerical examples are provided to verify the effectiveness of our results.

Низкотемпературный антиферромагнетизм в модели Изинга с конкурирующими взаимодействиями

The paper presents a numerical analysis of equilibrium state and spin configuration of square lattice Ising model with competing interaction. The most detailed description is given for case of ferromagnetic interaction of the first-order neighbours and antiferromagnetic coupling of the second-order neighbours. The numerical method is based on Metropolis algorithm. It uses 128×128 lattice with periodic boundary conditions. At first, the simulation results show that the system is in saturation state at low temperatures, and it turns into paramagnetic state at the Curie point. The competing second-order interaction makes possible the domain structure realization. This state is metastable, because its energy is higher than saturation energy. The domains are small at low temperature, and their size increases when temperature is growing until the single domain occupies the whole simulation area. In addition, the antiferromagnetic coupling of the second-order neighbours reduces the Curie temperature of the system. If it is large enough, the lattice has no saturation state. It turns directly from the domain state into paramagnetic phase. There are no extra phases when the system is antiferromagnetic in main order, and only the Neel temperature shift realizes here.

Distributed multi‐agent optimisation via coordination with second‐order nearest neighbours

The authors examine the distributed multi-agent optimisation problem allowing each agent to explicitly utilise the information of its first-order and second-order nearest neighbours for cooperative decision-making. Specifically, at each time instance, each agent in the network employs the states of its second-order nearest neighbours at the last time instance, which can be transmitted from its first-order nearest neighbours in practice. Under the proposed framework, they propose a distributed subgradient algorithm asymptotically leading all agents to an agreement on the optimal solution of the multi-agent optimisation problem under an appropriate selection of stepsize. Furthermore, they show that the proposed algorithm outperforms the existing algorithms built on the assumption that only the states of first-order neighbours are available in terms of the convergence rate.

Couple-group consensus for second-order multi-agent systems with the effect of second-order neighbours’ information

This paper investigates a couple-group consensus problem of second-order multi-agent systems with the impact of second-order neighbours’ information. For systems with/without time delays, couple-group consensus criteria are established in the form of linear matrix inequalities by utilizing both model transformation and stability theories. The main results indicate that the group consensus for multi-agent systems under the effect of second-order neighbours’ information can be achieved based on the premise of a generalized balanced couple. Finally, illustrative examples are presented to demonstrate the effectiveness of the theoretical results.

Consensus of linear multi-agent systems with communication delays by using the information of second-order neighbours under intermittent communication topology

ABSTRACTThis paper investigates the consensus of identical linear multi-agent systems with aperiodic intermittent communication topology by using the information of second-order neighbours (two-hop neighbourhood). The protocols based on two-hop neighbourhood information and intermittent communication topology are designed, under which consensus is reached. If the communication rate is larger than the corresponding threshold value, the networks will accelerate consensus by using two-hop neighbourhood information. By means of switching systems theory and Lyapunov–Razumikhin theorem, consensus of multi-agent systems with communication delays and intermittent communication topology is reached by two-hop neighbourhood information. Finally, simulation examples are provided to show the effectiveness of the theoretical results.

Necessary and sufficient conditions for multi-agent controllability of path and star topologies by exploring the information of second-order neighbours

AbstractThis article investigates the controllability of path and star graphs under the protocol of second-order neighbours. With identified special control nodes, a sufficient condition is first derived for the controllability of path graph by taking advantage of the protocol of second-order neighbours. Then necessary and sufficient conditions are developed respectively for the single and multiple leaders. Some differences between the protocol of second-order neighbours and first-order neighbours are also presented for path graph. Finally, a necessary and sufficient condition is proposed for the controllability of star graph by taking advantage of the protocol of second-order neighbours.

Event-triggered control for heterogeneous multi-agent systems with time-varying delays when using the second-order neighbours' information

This paper mainly investigates the event-triggered control for heterogeneous multi-agent systems with time-varying delays when both the first-order and the second-order neighbours' information are used. First, the heterogeneous multi-agent systems are composed of two kinds of agents differed by their dynamics. Then, event-triggered control laws are adopted so as to reduce the frequency of individual actuation updating under the sampled-data framework for discrete-time agent dynamics. By applying the Lyapunov functional method and the Kronecker product technique, two sufficient conditions for consensus are established in terms of linear matrix inequalities (LMIs) when the communication topologies are undirected connected graphs and switching networks. Finally, simulation examples are given to demonstrate the effectiveness of the proposed methods.

Assessing nodes importance in complex networks using structural holes

Accurate measurement of important nodes in complex networks has great practical and theoretical significance. Mining important nodes should not only consider the core nodes, but also take into account the locations of the nodes in the network. Despite much research on assessing important nodes, the importance of nodes in the structural holes is still easily ignored. Therefore, a local measuring method is proposed, which evaluates the nodes importance by the total constraints caused by the lack of primary structural holes and secondary structural holes around the nodes. This method simultaneously considers both the centrality and the bridging property of the nodes' first-order and second-order neighbours. Further to prove the accuracy of the method TCM, we carry out deliberate attack simulations through selective deletion in a certain proportion of network nodes. Then, we calculate the decreased ratio of network efficiency in the before-and-after attacks. Experiment results show that the average effect of the TCM in four real networks are improved by 50.64% and 14.92% compared to the clustering coefficient index and the k-shell decomposition method, respectively. Obviously, the TCM is more accurate to mine important nodes than other two methods, and it is suitable for quantitative analysis in large-scale networks.

English

In certain situations of experimentation using usual blocking each experimental plot contains direct effect of the treatment applied to it together with effects of treatments percolating from its neighbouring left and right plots. This paper is concerned with the study of block designs of OS1 Series for two sided (left and right) secondorder neighbour effects. Neighbour Designs can 2 be constructed using MOLS for the parameters v=s , b=s(s+1), r=s+1, k=s, e=1 where s is either a prime number or power of a prime number. Here left and right second-order neighbours of every treatment are finding out and it is observed that these neighbours follow the property of circularity of secondorder.

Accelerating average consensus by using the information of second-order neighbours with communication delays

This article investigates the problem of accelerating average consensus in undirected and connected networks. The protocol using the information of second-order neighbours with communication delays is proposed and the delay effects on stability and the convergence speed are analysed, respectively, under an assumption about the network topologies. It is proved that, for appropriate communication delays, networks reach average consensus faster under the proposed protocol than the standard protocol using only the information of first-order neighbours. Finally, a simulation example is presented to illustrate the proposed results.

Second-order consensus in multi-agent systems based on second-order neighbours’ information

This paper mainly investigates the consensus of second-order multi-agent systems by using the second-order neighbours’ information. The comparison between the convergence rate of second-order neighbour protocol and the one of general protocol is developed. When multi-agent system achieves maximum speed consensus, the relation between the parameter in general protocol and that in second-order neighbour protocol is analysed. If there exists delay in communication, the delay margins of general protocol and second-order neighbour protocol are derived. Numerical examples are given to illustrate the effectiveness of the proposed methods.

Multinationals, Geographical Spillovers, and Regional Development in Thailand

Sajarattanochote S. and Poon J. P. H. Multinationals, geographical spillovers, and regional development in Thailand, Regional Studies. Much of the evidence supporting the competency of agglomeration economies through regional spillovers is largely derived from industrialized countries. This literature focuses on the advantages of geographical clustering for firms' technological innovation. Their findings, however, are less relevant for a developing country like Thailand where human capital and technological capability is low. This paper examines the geography of technology flows among multinational enterprises located in the metropolitan region of Bangkok (BMA). It finds evidence of limited regional spillovers to first- and second-order neighbours. Transfer of technology to Thai firms further varies by nationality, sector, size, and age of multinational enterprises. Sajarattanochote S. et Poon J. P. H. Les sociétés multinationales, les retombées géographiques et l'aménagement du territoire en Thaïlande, Regional Studies. Beaucoup des preuves qui soutiennent la compétence des économies d'agglomération par moyen des retombées régionales proviennent dans une large mesure des pays industrialisés. Cette documentation porte sur les atouts de l'agglomération pour l'innovation des entreprises. Cependant, les résultats sont moins utiles pour un pays en voie de développement comme la Thaïlande, où le capital humain et la capacité technologique sont faibles. Cet article cherche à examiner le géographie des flux technologiques parmi les sociétés multinationales situées dans la région métropolitaine de Bangkok. Il s'avère que les retombées régionales sont limitées aux voisins de premier et de deuxième rang. Le transfert technologique aux entreprises thaïlandaises varient davantage en fonction de la nationalité, du secteur, de la taille et de l'ancienneté des sociétés multinationales. Sociétés multinationales Retombées géographiques Liens à rebours Liens Thaïlande Sajarattanochote S. und Poon J. P. H. Multinationale Konzerne, geografische Übertragungen und Regionalentwicklung in Thailand, Regional Studies. Ein Großteil der Belege für die Kompetenz von Agglomerationswirtschaften durch regionale Übertragungen wird aus industrialisierten Ländern abgeleitet. In dieser Literatur liegt der Augenmerk auf den Vorteilen einer geografischen Ballung für die technologische Innovation von Firmen. Für ein Entwicklungsland wie Thailand mit geringem Humankapital und technologischer Kapazität sind diese Ergebnisse hingegen weniger relevant. In diesem Beitrag wird die Geografie technologischer Ströme zwischen multinationalen Konzernen in der Metropolitanregion von Bangkok untersucht. Es werden Belege für begrenzte regionale Übertragungen an Nachbarn der ersten und zweiten Ordnung gefunden. Die Übertragung von Technologie an thailändische Firmen fällt zudem je nach Nationalität, Sektor, Größe und Alter der multinationalen Konzerne unterschiedlich aus. Multinationale Konzerne Geografische Übertragungen Rückwärtsverbindungen Vorwärtsverbindungen Thailand Sajarattanochote S. y Poon J. P. H. Empresas multinacionales, desbordamientos geográficos y desarrollo regional en Tailandia, Regional Studies. Muchas de las evidencias que apoyan la competencia de las economías de aglomeración a través de desbordamientos regionales proceden en gran parte de países industrializados. Esta literatura se centra en las ventajas de la agrupación geográfica para la innovación tecnológica de empresas. Sin embargo, sus resultados son menos relevantes para un país en vías de desarrollo como Tailandia que tiene un nivel bajo de capital humano y capacidad tecnológica. En este artículo examinamos la geografía de los flujos tecnológicos entre empresas multinacionales (EMN) ubicadas en la región metropolitana de Bangkok. Se observan evidencias de desbordamientos regionales limitados para vecinos de primer y segundo orden. Además, la transferencia de la tecnología a firmas tailandesas varía según la nacionalidad, el sector, el tamaño y la antigüedad de las EMN. Empresas multinacionales Desbordamientos geográficos Vínculos hacia atrás Vínculos hacia delante Tailandia

Influence of Non-Tetrahedral Cations on Si-O Vibrations in Complex Silicates

The effect of non-tetrahedral cations on the silicon–oxygen vibrational modes in complex silicates was modelled in a small-cluster approximation by introducing a shell containing first- and second-order neighbours of the peripheral oxygen atoms of the Si—O cluster. As an example, the proposed method was applied to study the Raman spectra of different types of tourmaline, which contain in their structure single six-membered rings of SiO4 tetrahedra. It is shown that in the range 450–750 cm−1 the Raman spectrum of the ring is sensitive to the type of cations in octahedral Y-positions and as a result the peaks shift and their shape modifies. Using such changes, one can estimate the occupation of Y positions in tourmalines by various cations.