A COMPREHENSIVE GEOSPATIAL KNOWLEDGE DISCOVERY FRAMEWORK FOR SPATIAL ASSOCIATION RULE MINING

Continuous advances in modern data collection techniques help spatial scientists gain access to massive and high-resolution spatial and spatio-temporal data. Thus there is an urgent need to develop effective and efficient methods seeking to find unknown and useful information embedded in big-data datasets of unprecedentedly large size (e.g., millions of observations), high dimensionality (e.g., hundreds of variables), and complexity (e.g., heterogeneous data sources, space–time dynamics, multivariate connections, explicit and implicit spatial relations and interactions). Responding to this line of development, this research focuses on the utilization of the association rule (AR) mining technique for a geospatial knowledge discovery process. Prior attempts have sidestepped the complexity of the spatial dependence structure embedded in the studied phenomenon. Thus, adopting association rule mining in spatial analysis is rather problematic. Interestingly, a very similar predicament afflicts spatial regression analysis with a spatial weight matrix that would be assigned a priori, without validation on the specific domain of application. Besides, a dependable geospatial knowledge discovery process necessitates algorithms supporting automatic and robust but accurate procedures for the evaluation of mined results. Surprisingly, this has received little attention in the context of spatial association rule mining. To remedy the existing deficiencies mentioned above, the foremost goal for this research is to construct a comprehensive geospatial knowledge discovery framework using spatial association rule mining for the detection of spatial patterns embedded in geospatial databases and to demonstrate its application within the domain of crime analysis. It is the first attempt at delivering a complete geo-spatial knowledge discovery framework using spatial association rule mining

The influence of human genetic variation on early transcriptional responses and protective immunity following immunization with Rotarix vaccine in infants in Ho Chi Minh City in Vietnam : a study protocol for an open single-arm interventional trial [awaiting peer review]

Background: Rotavirus (RoV) remains the leading cause of acute gastroenteritis in infants and children aged under five years in both high- and low-middle-income countries (LMICs). In LMICs, RoV infections are associated with substantial mortality. Two RoV vaccines (Rotarix and Rotateq) are widely available for use in infants, both of which have been shown to be highly efficacious in Europe and North America. However, for unknown reasons, these RoV vaccines have markedly lower efficacy in LMICs. We hypothesize that poor RoV vaccine efficacy across in certain regions may be associated with genetic heritability or gene expression in the human host. Methods/design: We designed an open-label single-arm interventional trial with the Rotarix RoV vaccine to identify genetic and transcriptomic markers associated with generating a protective immune response against RoV. Overall, 1,000 infants will be recruited prior to Expanded Program on Immunization (EPI) vaccinations at two months of age and vaccinated with oral Rotarix vaccine at two and three months, after which the infants will be followed-up for diarrheal disease until 18 months of age. Blood sampling for genetics, transcriptomics, and immunological analysis will be conducted before each Rotarix vaccination, 2-3 days post-vaccination, and at each follow-up visit (i.e. 6, 12 and 18 months of age). Stool samples will be collected during each diarrheal episode to identify RoV infection. The primary outcome will be Rotarix vaccine failure events (i.e. symptomatic RoV infection despite vaccination), secondary outcomes will be antibody responses and genotypic characterization of the infection virus in Rotarix failure events. Discussion: This study will be the largest and best powered study of its kind to be conducted to date in infants, and will be critical for our understanding of RoV immunity, human genetics in the Vietnam population, and mechanisms determining RoV vaccine-mediated protection. Registration: ClinicalTrials.gov, ID: NCT03587389. Registered on 16 July 2018

UNIVERSITY OF CALGARY Performance Evaluation of Multiple Reference Station GPS RTK for a Medium Scale Network

ii Carrier phase-based single reference station (SRS) positioning is capable of providing decimetre to centimetre-level accuracy for static and kinematic positioning under normal atmospheric conditions where the inter-antenna distance is relatively short, namely below ten to twenty kilometres. However, under highly localized atmospheric activity, and/or with a longer inter-antenna distance, the residual differential error increases and the accuracy degrades. Carrier phase integer ambiguity resolution may be impossible. Multiple reference station (MRS) approaches uses a network of GPS reference stations to predict the differential errors over a geographic region. The University of Calgary standard MRS approach uses a conditional least-squares adjustment technique. During the past few years, an MRS tightly-coupled approach, which used all available observables obtained at rover and network reference stations in one filter, was also developed; the objective of this approach was solely to estimate states such as ambiguities, rover position and ionospheric error, if specified

Performance evaluation of multiple reference station GPS RTK for a medium scale networkby

Bibliography: p. 169-174Some pages are in colour

Performance evaluation of multiple reference station GPS RTK for a medium scale network : by/ Thi Hong Diep Dao

Bibliography : p. 169-174. Some pages are in colour.Copyright Clearance Form: yUAR

A Simple Time Synchronization Scheme for Satellite Clusters in Formation Flying

Future communications may use many small satellites flying as a cluster. Such a cluster helps to synthesize very large antennae in space, wherein each satellite becomes the node or element of the antenna structure. A key factor in such a cluster, is the positioning of satellites in absolute as well as relative terms and the time synchronization between them. Ultra Wide Band (UWB) techniques have promising applications for small satellites, because they require only a very small power and support both navigation and communication. In this paper a simple technique i.e ‘transmit and listen’ method is used to demonstrate the time synchronization between the members of the cluster. One member satellite, ‘mother’, is assumed to have the capability to retransmit or reflect back the signals from the ‘child’ satellites. To begin the process of synchronization, a child satellite transmits a pulse and starts a counter. The pulse reaches the mother and gets reflected back and received by the same child after a time equal to the round-trip delay. Using the time instants of the transmitted and received signals the clock offset is calculated. The offset is partially or fully corrected in the next transmission of the signals. By this process, the clock of child slowly gets synchronized with the mother. Matlab simulations show that synchronization is achieved within about 50 cycles. Once synchronized, subsequent pulses can be used to calculate the distance and thus maintain the formation using an appropriate relative navigation algorithm

Metric, Topological, and Syntactic Accessibility in Three-Dimensional Urban Networked Spaces: Modeling Options and Visualization

In this paper, we take the position that cities gain to be represented as three-dimensional spaces populated by scores of micro-scale-built spaces (buildings, rooms, passageways, squares, etc.). Effective algorithms that evaluate place-based accessibility in built structures while considering the indoor spaces’ complexity at a fine granularity are essential for indoor–outdoor seamless urban planning, navigation, way findings, and supporting emergencies. We present a comprehensive set of spatial modeling options and visualizations of indoor accessibility for an entire built structure based on various notions of travel impedance. Notably, we consider the metric length of the paths and their cognitive complexities due to topologic, syntactic, or integrated intricacy within our approaches. Our work presents a comprehensive selection of indoor accessibility analysis with a detailed implemental discussion that can be applied as a solid foundation for smart city applications or seamless urban research and planning. The analysis and visualization techniques presented in this paper can be easily applied to analyze and visualize built interior geographic spaces to study accessibility differentials in cities with vast vertical expansion aimed at achieving (or at avoiding) specific accessibility outcomes

Impact of Leadership Behavior on Entrepreneurship in State-Owned Enterprises: Evidence from Civil Servant Management Aimed at Improving Accountability

This paper systematizes the theoretical foundation and empirical evidence of the impact of leadership behavior on entrepreneurship in state-owned enterprises, and the difference between state-owned enterprises that applied management based on the accountability of leaders, and those that did not. The paper uses the OLS regression model to identify the impact of leadership behavior on the entrepreneurship of state-owned enterprises by using data from a survey of 259 civil servants in Vietnamese state-owned enterprises. In our sample, 109 respondents belonged to the category of state-owned enterprises that did not apply management based on accountability, and 140 were state-owned enterprises that applied management based on accountability. The findings show that leadership behavior has a positive impact on the entrepreneurship of state-owned enterprises that do and do not apply management based on accountability, with results of 0.305 and 0.022, respectively. Moreover, the regression model is used to identify the factors that influence leadership behavior, including vision and wage policy having a statistical significance and positive impact on the leadership behaviors in all the state-owned enterprises. Additionally, some factors, including policy building, hi-tech usage, culture, teamwork, and training policy have positive impacts on leadership behavior in Model 1, and encouragement, monitoring, responsibility, and recruitment policy had positive impacts in Model 2 among the state enterprises. Additionally, this paper recommends some policies to promote leadership behavior in state enterprises in Vietnam