Ecological network construction based on minimum cumulative resistance for the City of Nanjing, China

With economic growth and the improvement of the urbanization level, human activities have constantly interfered with landscape patterns, resulting in serious threats to regional ecological security. Therefore, it is of great significance to study the evolution and optimization of the landscape patterns. Based on three TM images from 1990, 2000, and 2010, and selected landscape pattern indexes, the changes in the landscape pattern of Nanjing in the past twenty years were studied based on landscape ecology theory using Remote Sensing (RS) and a Geographical Information System (GIS). The ecological network was built on the basis of extracted ecological nodes and the minimum cumulative resistance. The results show that changes in the landscape pattern of the city of Nanjing were notable. Class-level indexes indicate that the farmland landscape area decreased and the degree of patch fragmentation increased. The construction land area increased, and it tended to show dispersed distribution. The proportion of forest land increased and the shape of patches became more complex. The proportion of water firstly showed a decrease, followed by an increase, and the shape of the water became more regular. Landscape-level indexes indicate that biological diversity and the degree of fragmentation increased. Spatial heterogeneity of the natural landscape increased, and the patch shape of each landscape type developed similarly. The results also call for stepping-stones to enhance the connectivity and optimization of the ecological network, which will help improve ecological services and improve the landscape pattern of the city

Ecological Network Construction Based on Minimum Cumulative Resistance for the City of Nanjing, China

With economic growth and the improvement of the urbanization level, human activities have constantly interfered with landscape patterns, resulting in serious threats to regional ecological security. Therefore, it is of great significance to study the evolution and optimization of the landscape patterns. Based on three TM images from 1990, 2000, and 2010, and selected landscape pattern indexes, the changes in the landscape pattern of Nanjing in the past twenty years were studied based on landscape ecology theory using Remote Sensing (RS) and a Geographical Information System (GIS). The ecological network was built on the basis of extracted ecological nodes and the minimum cumulative resistance. The results show that changes in the landscape pattern of the city of Nanjing were notable. Class-level indexes indicate that the farmland landscape area decreased and the degree of patch fragmentation increased. The construction land area increased, and it tended to show dispersed distribution. The proportion of forest land increased and the shape of patches became more complex. The proportion of water firstly showed a decrease, followed by an increase, and the shape of the water became more regular. Landscape-level indexes indicate that biological diversity and the degree of fragmentation increased. Spatial heterogeneity of the natural landscape increased, and the patch shape of each landscape type developed similarly. The results also call for stepping-stones to enhance the connectivity and optimization of the ecological network, which will help improve ecological services and improve the landscape pattern of the city

runtime verification of data-centric properties in service based systems

For service-based systems which are composed of multiple independent stakeholders, correctness cannot be ascertained statically. Continuous monitoring is required to assure that runtime behavior of the systems complies with specified properties. However, most existing work considers only the temporal constraints of messages exchanged between services, ignoring the actual data contents inside the messages. As a result, it is difficult to validate some dynamic properties such as how message data of interest is processed between different participants. To address this issue, this paper proposes an efficient, online monitoring approach to dynamically analyze data-centric properties in service-based systems. By introducing Par-BCL - a Parametric Behavior Constraint Language for Web services - various data-centric properties can be specified and monitored. To keep runtime overhead low, we statically analyze the monitored properties to generate parameter state machine, and combine two different indexing mechanisms to optimize the monitoring. The experiments show that the proposed approach is efficient. © 2012 Springer-Verlag.For service-based systems which are composed of multiple independent stakeholders, correctness cannot be ascertained statically. Continuous monitoring is required to assure that runtime behavior of the systems complies with specified properties. However, most existing work considers only the temporal constraints of messages exchanged between services, ignoring the actual data contents inside the messages. As a result, it is difficult to validate some dynamic properties such as how message data of interest is processed between different participants. To address this issue, this paper proposes an efficient, online monitoring approach to dynamically analyze data-centric properties in service-based systems. By introducing Par-BCL - a Parametric Behavior Constraint Language for Web services - various data-centric properties can be specified and monitored. To keep runtime overhead low, we statically analyze the monitored properties to generate parameter state machine, and combine two different indexing mechanisms to optimize the monitoring. The experiments show that the proposed approach is efficient. © 2012 Springer-Verlag

runtime monitoring of data-centric temporal properties for web services

IEEE; IEEE Computer Society (CS); TC-SVC; IBM; SAPRuntime monitoring of Web service compositions has been widely acknowledged as a significant approach to understand and guarantee the quality of services. However, existing runtime monitoring solutions consider only the constraints on the sequence of messages exchanged between partner services and ignore the actual data contents inside the messages. As a result, it is difficult to monitor some dynamic properties such as how message data of interest is processed between different participants. To address this issue, we propose an efficient, non-intrusive online monitoring approach to dynamically analyze data-centric properties for service-oriented applications involving multiple participants. By introducing Par-BCL - a Parametric Behavior Constraint Language for web services - to define monitoring parameters, various data-centric temporal behavior properties for Web services can be specified and monitored. This approach broadens the monitored patterns to include not only message exchange orders, but also the data contents bound to the parameters. To reduce runtime overhead, we statically analyze the monitored properties to generate parameter state machine from the event pattern automata to optimize monitoring. The experiments show that our solution is efficient and promising. © 2011 IEEE

Nano-Domains Produced through a Two-Step Poling Technique in Lithium Niobate on Insulators

We proposed a two-step poling technique to fabricate nanoscale domains based on the anti-parallel polarization reversal effect in lithium niobate on insulator (LNOI). The anti-parallel polarization reversal is observed when lithium niobate thin film in LNOI is poled by applying a high voltage pulse through the conductive probe tip of atomic force microscope, which generates a donut-shaped domain structure with its domain polarization at the center being anti-parallel to the poling field. The donut-shaped domain is unstable and decays with a time scale of hours. With the two-step poling technique, the polarization of the donut-shaped domain can be reversed entirely, producing a stable dot domain with a size of tens of nanometers. Dot domains with diameter of the order of ∼30 nm were fabricated through the two-step poling technique. The results may be beneficial to domain-based applications such as ferroelectric domain memory