Geographic Services Research Articles

New organ allocation policy in liver transplantation in the United States.

New organ allocation policy in liver transplantation in the United States.

Contribution of congenital disorders to under-5 mortality

To the Editor : The article 'Where do children die and what are the causes?', which appeared in the April 2016 issue of the SAMJ, provides an overview of the causes of death in under-5 children in the Metro West geographical service area of the Western Cape for 2011. It highlights the proportion of under-5 deaths from congenital abnormalities (obvious structural abnormalities), which are particularly prevalent in early neonatal mortality - a close third (9.6%) of in-hospital deaths after hypoxia (10.0%) and immaturity (40.6%) according to the Perinatal Problem Identification Programme (PPIP) data. In the Local Mortality Surveillance System in-hospital data, congenital abnormalities are ranked as the second (13.5%) cause of early neonatal death after prematurity (35.8%).

A Data Volume Aware Ant Colony Optimization Approach for Geographical Knowledge Cloud Service Composition

Geographical knowledge cloud service is a typical online service that provides big spatial data analysis with the function of knowledge discovery or decision-making. The composition of geographical knowledge cloud service imposes stricter requirements for better overall QoS and execution efficiency of the service chain. In this paper, we present a data volume aware ant colony optimization approach called DVA-MOACO algorithm for geographical knowledge cloud service composition. Our algorithm utilizes a multi-index service quality evaluation model, and improves the transition probability while considering the data transfer cost and other QoS constraints simultaneously when ant finding path. Our algorithm could reach the Pareto near optimal solution rapidly with better QoS performance and lower data transfer cost from numerous candidate solutions.

Integrated Case Management: Does It Reduce Health Service Disparities Across African American and White Medicaid Beneficiaries?

Evidence of persistent racial and ethnic disparities in health service use is substantial. Even among Medicaid beneficiaries, minority individuals may have lower use of specific health services relative to Whites due to varying degrees of trust in the health system, beliefs about the usefulness of medical treatment, provider stereotyping, or geographic service availability. Prior research demonstrated that a Florida Medicaid disease management program led to reductions in service disparities between Whites and African Americans. We study a Medicaid Integrated Case Management program implemented in Virginia, which shares disease management program objectives but can be applied to a broader range of patients. Two versions of the program are assessed, the latter of which incorporated more patient-focused and targeted approaches in identifying client needs and structuring patient interaction. Both versions of the program were associated with reductions in disparities, especially for physician services and when more targeted, patient-centered approaches were adopted.

A Cloud Computing-Enabled Spatio-Temporal Cyber-Physical Information Infrastructure for Efficient Soil Moisture Monitoring

Comprehensive surface soil moisture (SM) monitoring is a vital task in precision agriculture applications. SM monitoring includes remote sensing imagery monitoring and in situ sensor-based observational monitoring. Cloud computing can increase computational efficiency enormously. A geographical web service was developed to assist in agronomic decision making, and this tool can be scaled to any location and crop. By integrating cloud computing and the web service-enabled information infrastructure, this study uses the cloud computing-enabled spatio-temporal cyber-physical infrastructure (CESCI) to provide an efficient solution for soil moisture monitoring in precision agriculture. On the server side of CESCI, diverse Open Geospatial Consortium web services work closely with each other. Hubei Province, located on the Jianghan Plain in central China, is selected as the remote sensing study area in the experiment. The Baoxie scientific experimental field in Wuhan City is selected as the in situ sensor study area. The results show that the proposed method enhances the efficiency of remote sensing imagery mapping and in situ soil moisture interpolation. In addition, the proposed method is compared to other existing precision agriculture infrastructures. In this comparison, the proposed infrastructure performs soil moisture mapping in Hubei Province in 1.4 min and near real-time in situ soil moisture interpolation in an efficient manner. Moreover, an enhanced performance monitoring method can help to reduce costs in precision agriculture monitoring, as well as increasing agricultural productivity and farmers’ net-income.

Where do children die and what are the causes? Under-5 deaths in the Metro West geographical service area of the Western Cape, South Africa, 2011.

Accurate child mortality data are essential to plan health interventions to reduce child deaths. To review the deaths of children aged <5 years during 2011 in the Metro West geographical service area (GSA) of the Western Cape Province (WC), South Africa, from routine data sources. A retrospective study of under-5 deaths in the Metro West GSA was done using the WC Local Mortality Surveillance System (LMSS), the Child Healthcare Problem Identification Programme (Child PIP) and the Perinatal Problem Identification Programme (PPIP), and linking where possible. The LMSS reported 700 under-5 deaths, Child PIP 99 and PPIP 252, with an under-5 mortality rate of 18 deaths per 1 000 live births. The leading causes of death were pneumonia (25%), gastroenteritis (10%), prematurity (9%) and injuries (9%). There were 316 in-hospital deaths (45%) and 384 out-of-hospital deaths (55%). Among children aged <1 year, there were significantly more pneumonia deaths out of hospital than in hospital (144 (49%) v. 16 (6%); p<0.001). Among children aged 1 - 4 years there were significantly more injury-related deaths out of hospital than in hospital (43 (47%) v. 4 (9%); p<0.001). In 56 (15%) of the cases of out-of-hospital death the child had visited a public healthcare facility within 1 week of death. Thirty-six (64%) of these children had died of pneumonia or gastroenteritis. Health interventions targeted at reducing under-5 deaths from pneumonia, gastroenteritis, prematurity and injuries need to be implemented across the service delivery platform in the Metro West GSA. It is important to consider all routine data sources in the evaluation of child mortality.

Enabling Scalable Geographic Service Sharing with Weighted Imprecise Voronoi Cells

We provide techniques that enable a scalable so-called Volunteered Geographic Services system. This system targets the increasing populations of online mobile users, e.g., smartphone users, enabling such users to provide location-based services to each other, thus enabling citizen reporter or citizen as a sensor scenarios. More specifically, the system allows users to register as service volunteers, or micro-service providers, by accepting service descriptions and periodically updated locations from such volunteers; and the system allows users to subscribe to notifications of available, nearby relevant services by accepting subscriptions, formalized as continuous queries, that take service preferences and user locations as arguments and return relevant services. Services are ranked according to their relevance and distance to a query, and the highest ranked services are returned. The key challenge addressed is that of scalably providing up-to-date results to queries when the query locations change continuously. This is achieved by the proposal of a new so-called safe-zone model. With safe zones, query results are accompanied by safe zones with the property that a query result remains the same for all locations in its safe zone. Then, query users need only notify the system when they exit their current safe zone. Existing safe-zone models fall short in the papers setting. The new model is enabled by (i) weighted and (ii) set weighted imprecise Voronoi cells. The paper covers underlying concepts, properties, and algorithms, and it covers applications in VGS tracking and presents findings of empirical performance studies.

Method for Estimating Statewide Transit Needs and Investment Priorities for Rural and Small Urban Areas

This study demonstrated a method for identifying statewide transit needs and gaps, prioritizing investment needs for statewide transit planning, collecting better data for the demand-response transit level of service, estimating costs of needed improvements, and projecting service needs based on projected population growth. The method was applied to the state of North Dakota and is transferable to any state, especially those with a large number of rural demand-response transit agencies that are not located within metropolitan planning areas. Currently, data in the National Transit Database are insufficient for analyzing the level of service for rural transit agencies because the database lacks information on geographic service area and span of service. A survey conducted for this study filled this data need by collecting detailed information regarding each agency’s service area and the number of days and hours of service being provided. These data combined with population and demographic data are useful for identifying gaps in transit service and prioritizing needed service improvements. The study also calculated per capita trips, vehicle miles, and vehicle hours provided in regions across the state. These performance measures were compared with benchmark values to identify areas in which the transit system may not be meeting the needs of the service area population, with the understanding that needs are not identical in all areas. The study estimated necessary increases in service and funding to meet target levels in different scenarios. Population projections were also considered for estimating needed increases in service and funding.

Service Region Design for Urban Electric Vehicle Sharing Systems

Emerging collaborative consumption business models have shown promise in terms of both generating business opportunities and enhancing the efficient use of resources. In the transportation domain, car sharing models are being adopted on a mass scale in major metropolitan areas worldwide. This mode of servicized mobility bridges the resource efficiency of public transit and the flexibility of personal transportation. Beyond the significant potential to reduce car ownership, car sharing shows promise in supporting the adoption of fuel-efficient vehicles, such as electric vehicles (EVs), due to these vehicles’ special cost structure with high purchase but low operating costs. Recently, key players in the car sharing business, such as Autolib, Car2Go and DriveNow, have begun to employ EVs in an operations model that accommodates one-way trips. On the one hand (and particularly in free-floating car sharing), the one-way model results in significant improvements in coverage of travel needs and therefore in adoption potential compared with the conventional round-trip-only model (advocated by ZipCar, for example). On the other hand, this model poses tremendous planning and operational challenges. In this work, we study the planning problem faced by service providers in designing a geographical service region in which to operate the service. This decision entails trade-offs between maximizing customer catchment by covering travel needs and controlling fleet operations costs. We develop a mathematical programming model that incorporates details of both customer adoption behavior and fleet management (including EV repositioning and charging) under imbalanced travel patterns. To address inherent planning uncertainty with regard to adoption patterns, we employ a distributionally robust optimization framework that informs robust decisions to overcome possible ambiguity (or lacking) of data. Mathematically, the problem can be approximated by a mixed integer second-order cone program, which is computationally tractable with practical scale data. Applying this approach to the case of Car2Go's service with real operations data, we address a number of planning questions and suggest that there is potential for the future development of this service.

Embedded mobile crowd service systems based on opportunistic geological grid and dynamical segmentation

In order to solve these problems such as the demand of geographic information service and the short life of the embedded system, as well as network collapse, and so on, the embedded mobile crowd service systems based on opportunistic geological grid and dynamical split was proposed. Firstly, based on the characteristics of geographical spatial information resources and service time series, a mobile geographic crowd service system was established for providing the sensing data with the mobile geographic crowd service model. Then, according to the embedded equipment complex data of the geographic crowd service system, and the relationship between the geography information service object and the user, the embedded system was proposed based on the opportunity geological grid. Finally, the optimization of the geographic crowd system was realized by the dynamic segmentation of the opportunity geographic grid. The experiment results of the equipment utilization, the life cycle of the crowd network, user satisfaction, and control complexity show that the proposed scheme is more suitable for the embedded network geographic information system.

A framework for teaching the timeless way of mapmaking

There are now many opportunities to learn how to make maps through technical training with mapmaking tools, including geographic information systems and web-based mapping services. In cartographic education, two challenges with teaching through practice stem from the disruptive nature of mapmaking tools and the tradition of teaching cartographic principles by rule or convention. This article outlines a framework for a pattern language to organize and share practical information about principles for making maps. The article provides an example pattern for mapmaking and discusses how this framework addresses recurring problems with teaching through practice.

Residential segregation and well-being inequality over time: A study on the local and migrant elderly people in Shanghai

China achieved great economic success during the market transition, but is now facing increasing social problems and challenges, such as institutional inequality and population ageing. A consequence of this institutional inequality due to the Hukou system is the emerging segregation in cities between locals and migrants. This segregation is growing during last decades and exerts negative implications on the well-being distribution between locals and migrants including their older subcategories. This paper focuses on the residential segregation between local and migrant elderly people and its implications on their access to geographical resources and on their well-being in central Shanghai over the period 2000–2010. Access to geographical services and resources for the elderly is employed as the proxy for their well-being measurement. This paper concludes that the forthgoing housing market reform over the last decade has intensified the differentiations of housing price and new housing distribution, especially those of high-priced commercial housing, resulting in a slightly strengthened residential segregation between local and migrant elderly people. As a consequence, this segregation continues to produce inequality in the well-being distribution between these two elderly groups. However, this paper also shows that the inequality gap has been slightly narrowed due to the greater well-being improvement of migrant elderly.

The impact of minor injury unit closures on travel time and attendances

Geographic modelling techniques provide a means of optimising the location of services, or understanding the potential impact of geographic service reconfigurations. In response to commissioner queries, we assessed the potential impact on patient travel time and attendances of the closure of four minor injury units (MIUs) in a locality of South West England. We used the MPMileCharter add-in for Microsoft MapPoint and the attendance records of 90 252 minor injury unit patients to calculate car travel time data to the units in the locality. We then built a geographic model of the existing configuration of MIUs in Microsoft Excel, and used ‘what if’ analysis to determine the potential impact of the proposed closures. The model predicted that if the four MIUs were closed, there would be only a trivial increase in average travel time across all patients, but a significant increase of around 20 minutes per patient for those whose nearest unit was closed. The model also predicted that the closure of one of the MIUs could lead to significant increased demand at the walk-in centre located at the acute hospital. Using these results, the local commissioners decided to close only three of the four units.

Patterns and determinants of care seeking for obstetric complications in rural northwest Bangladesh: analysis from a prospective cohort study.

BackgroundIn communities with low rates of institutional delivery, little data exist on care-seeking behavior for potentially life-threatening obstetric complications. In this analysis, we sought to describe care-seeking patterns for self-reported complications and near misses in rural Bangladesh and to identify factors associated with care seeking for these conditions.MethodsUtilizing data from a community-randomized controlled trial enrolling 42,214 pregnant women between 2007 and 2011, we used multivariable multinomial logistic regression to explore the association of demographic and socioeconomic factors, perceived need, and service availability with care seeking for obstetric complications or near misses. We also used multivariable multinomial logistic regression to analyze the factors associated with care seeking by type of obstetric complication (eclampsia, sepsis, hemorrhage, and obstructed labor).ResultsOut of 9,576 women with data on care seeking for obstetric complications, 77% sought any care, with 29% (n = 2,150) visiting at least one formal provider and 70% (n = 5,149) visiting informal providers only. The proportion of women seeking at least one formal provider was highest among women reporting eclampsia (57%), followed by hemorrhage (28%), obstructed labor (22%), and sepsis (17%) (p < 0.001). In multivariable analyses, socioeconomic factors such as living in a household from the highest wealth quartile (Relative Risk Ratio of 1.49; 95% CI of [1.33-1.73]), women’s literacy (RRR of 1.21; 95% CI of [1.05-1.42]), and women’s employment (RRR of 1.10; 95% CI of [1.01-1.18]) were significantly associated with care seeking from formal providers. Service factors including living less than 10 kilometers from a health facility (RRR of 1.16; 95% CI of [1.05-1.28]) and facility availability of comprehensive obstetric services (RRR of 1.25; 95% CI of 1.04-1.36) were also significantly associated with seeking care from formal providers.ConclusionsWhile the majority of women reporting obstetric complications sought care, less than a third visited health facilities. Improvements in socioeconomic factors such as maternal literacy, coupled with improved geographic access and service availability, may increase care seeking from formal facilities. Enhancing community awareness on symptoms of hemorrhage, sepsis, and obstructed labor and their consequences may promote care seeking for obstetric complications in rural Bangladesh.Trial registrationTrial Registration Number: NCT00860470.

Parallel and Distributed Spatial Outlier Mining in Grid: Algorithm, Design and Application

There is an increasing interest in the field of parallel and distributed data mining in grid environment over the past decade. As an important branch of spatial data mining, spatial outlier mining can be used to find out some interesting and unexpected spatial patterns in many applications. In this paper, a new parallel & distributed spatial outlier mining algorithm (PD-SOM) is proposed to simultaneously detect global and local outliers in a grid environment. PD-SOM is a Delaunay triangulation (D-TIN) based approach, which was encapsulated and deployed in a distributed platform to provide parallel and distributed spatial outlier mining service. Subsequently, a distributed system framework for PD-SOM is designed on top of a geographical knowledge service grid (GeoKSGrid) developed by our research group, a two-step strategy for spatial outlier detection is put forward to support the encapsulation and distributed deployment of the geographical knowledge service, and two key techniques of the geographical knowledge service: parallel and distributed computing of Delaunay triangulation and the implementation of PD-SOM algorithm are discussed. Finally, the efficiency of the spatial outlier mining service is analyzed in theory, the practicality is confirmed by a demonstrative application on the abnormality analyzing of soil geochemical investigation samples from Fujian eastern coastal zone area in China, and the effectiveness and superiority of PD-SOM in a balanced, scalable grid environment are verified through the comparison with the popular spatial outlier mining algorithm SLOM, for the involvement of large amount of computing cores.

Regional availability of mechanical embolectomy for acute ischemic stroke in California, 2009 to 2010.

Background and Purpose—We sought to assess the geographic proximity of patients with stroke in California to centers that performed specific threshold volumes of mechanical embolectomy procedures each year.Methods—We identified all patients who were hospitalized for acute ischemic stroke at all nonfederal acute care hospitals in California from 2009 to 2010, and all hospitals that performed any mechanical embolectomy procedures by case volume during the same period, using nonpublic data from the Office of Statewide Health Planning and Development. We computed geographic service areas around each hospital on the basis of prespecified ground transport distance thresholds. We then calculated the proportion of hospitalized patients with stroke who lived within service areas for centers that performed a low volume and high volume of mechanical embolectomy procedures each year.Results—During the 2-year study period, 15% (53/360) of hospitals performed at least 1 mechanical embolectomy for acute stroke, but only 19% (10/53) performed >10 cases per year. Most hospitalized patients with stroke (94%) lived within a 2-hour transport time (65 miles) to a hospital that performed ≥1 procedure during the 2-year period. Approximately 93% of the patients with stroke who received mechanical embolectomy lived within 20 miles from an embolectomy-capable hospital compared with 7% of those who lived >20 miles.Conclusions—In California, most patients with stroke lived within reasonable ground transport distances from centers that performed ≥1 mechanical embolectomy in a 2-year period. The probability of receiving mechanical embolectomy for acute ischemic stroke was associated with living in close geographic proximity to these hospitals.

Evaluating Social Navigation Visualization in Online Geographic Maps

Social navigation enables emergent collaboration between independent collaborators by exposing the behavior of each individual. This is a powerful idea for web-based visualization, where the work of one user can inform other users interacting with the same visualization. Results from a crowdsourced user study evaluating the value of such social navigation cues for a geographic map service are presented. Results show significantly improved performance for participants who interacted with the map when the visual footprints of previous users were visible.

Cloud Computing Research Vehicle Traffic Information Service System Based on Network

In vehicle network under the cloud computing environment model of traffic information service system construction as the goal, the use of cloud computing technology and service oriented software architecture is divided into thought, differentiation and security mechanism from the service account, complete vehicle based on cloud computing network traffic information service system of the letter of the architecture design, function design, software structure design. Based on the geographical space cloud services, cloud services based car networking function, constructing high performance, scalable, supporting differentiated information service system. The research results show that: cloud computing car network traffic information service collaborative system can greatly improve the level of intelligent, personalized information service based on traffic, the user required service supply pertinence increased significantly； system can provide traffic information service more safe and reliable for vehicle network users of the service coordination, which helps to guarantee Intelligent Transportation and efficient operation.

IBeacon을 이용한 스마트 디바이스 분실 방지 시스템

Todays, the rapid technical progress of smart device has been used for various social (wall-fare) services in our lives. Especially, most of these services are based on the Local-based Services (LBS) and this technology is getting popular more and more compared with before. Basically, LBS is able to support various types of geographical services such as vehicles’ navigation services, Augmented reality services as using extensional local information such as GPS. However, LBS has serious mathematical vulnerability on the services frequently because of its miscalculated GPS data under interior and ambiguous geographical environment such like shadowed area. So, to overcome this limitation, iBeacon, which would be able to mitigate LBS miscalculation process, has been proposed recently among network experts. Compared with other wireless technologies, iBeacon is able to determine the accurate geographical data of certain local positions easily because it is not only designed based on low-powered data transmitting technology, but also, it can be much easy to be deployed. As users’ dependency of smart devices are getting higher and higher and the use of smart device is also getting complex more and more, the users prefer to use various types of smart devices at one time. Therefore, in this paper, we propose the loss prevention system that is able to interwork smart devices networks as using iBeacon technology for users’ better conveniences. ☞ keyword : Smart Device, Loss Prevention, iBeacon, Android

Mobile Access to Sensor Networks by Using GIS Standards and RESTful Services

There is an increasing deployment of sensor net- works that measure the physical state of the environment. These networks provide large volumes of data in many different formats, resolution and scales. The data are of different types and character: from meteorological conditions to air quality and the concentrations of pollutants due to human activity, such as transportation or other industry-related actions. Current sensor networks publish this data in different formats. This implies not offering standard access to different data sources. These varieties of formats lead to an interoperability problem. Also, access to these sources is not fast and agile; it impedes access through mobile devices. The work in this paper aims at increasing the interoperability and improving accessibility of data provided by sensor networks. In this way, this data can be employed by different devices and with diverse context requirements, such as specific location and time. To address this problem Geographic Information System services, such as the Sensor Observation Service, in conjunction with Representational State Transfer architecture are used. A standard-based solution that increases interoperability is pre- sented. It also allows for a better integration of data that has already been published in different semi-structured formats in order to be used by various platforms (web or mobile). Furthermore, this system adds value to original sensor data in order to assist in the decision making process. Finally, to illustrate how to use these services, a mobile application that shows the hot-spots following Air Quality Index has been developed.