Landmark Based Path Planning And Linear Path Generation For Mobile Map Applications

Landmarks are yet to be integrated with mainstream mobile phone based navigation aids. In geographical regions where land marks are commonly used by the community for navigation support, the lack of them in electronic navigation aids make them less useful for such communities. In this study a land marks based navigation model is derived considering the value of them for local community in Sri Lanka. The landmarks can be prominent or not, make sense only during certain time of the day or been important differently for people with different age groups. We assume that the attributes of landmarks can be used to give a strength value for them for navigation. In this study three parameters, the visibility of them at different time of the day, the horizontal spread of the landmark and the height of them are considered as attributes which gives strength to a landmark. First, to give more importance to landmarks, we have developed an algorithm where not only the distance of a route but the strength of landmarks is also considered when selecting the best route to navigate. The Dijikstra algorithm is used as the base which output possible shortest paths considering only the distance. This algorithm was enhanced to output the optimum paths considering both the distance and the strength of landmarks along it. If the route is having more strength related to landmarks, it is prioritized. The route’s strength is defined based on number of landmarks visible along it and the strength of them. In order to calculate the number of landmarks along a route a landmark buffer is used. The day/night visibility and the height/spread are used to calculate the strength of the landmarks along the route. Second, to utilize the mobile screen in more effective manner which has the size limitation, map generalization approach is used when showing the navigation path. We have identified that after placing landmarks on a mobile screen, the map become too congested and it becomes difficult to read the navigation path. This is more prominent when the path is having many turns. The selected path is reduced to a linear map which shows the path reducing curves while emphasising the turns by markers. The linear map, which is a schematic representation of the actual map, reduces the path between junctions to straight lines. The junctions and turns are also incorporated to the resulting map. The landmarks around significant turns are also provided and guidance is provided based on landmarks. Douglas-Peucker algorithm is used to derive the linear path. A prototype implementation is done using mobile web approach to reduce the platform dependency. In the simple mobile web application developed, jQuery mobile, and php are used for the user interface development and server side implementations respectively. PostgreSQL with postGIS capabilities and pgRouting is used as a spatial database. Web services and smart queries are used to implement the basic functionalities communicating with the spatial database and the front end. The application is still being verified and tested in Sri Lanka at the moment

Evaluation of optimum service area for bulk depots for petroleum distribution

Ceylon Petroleum Storage Terminals (CPSTL) is responsible of distributing fuel throughout Sri Lanka. The fuel is transported from main terminals to bulk depots and subsequently to fuel stations using rail wagons and tank lorries. The costs from the two modes are considerably different and therefore, a need has arisen to optimize the fuel distribution process in order to minimize transportation and operational costs. The optimization has to happen in both the main terminal to bulk depot transportation and subsequent transportation to fuel station. Main terminal to bulk depot transportation consists of finding the optimum usage of rail and road modes and several researches had been done covering optimizing this distribution process. This research will introduce a model to optimize the distribution from bulk depots to fuel stations by optimizing the service area of each bulk depot

Effects of the “plate model” as part of dietary intervention on modification of selected cardiometabolic risk factors in post-myocardial infarction patients: study protocol for a randomized controlled trial

Abstract Background Cardiovascular disease remains the leading cause of morbidity and mortality worldwide, and there is a rising global burden. The effects of diet on cardiometabolic risk factors have been studied extensively. Healthy eating as a cost-effective approach to risk reduction in post-myocardial infarction patients is proven to be beneficial, and the “plate model” is one of the practical methods to achieve this objective. Methods/design The study will be conducted as a randomized, single-blind, controlled clinical trial for a period of 3 months. A total of 120 overweight (body mass index >23 kg/m2) inpatients (aged 20–70 years) with a history of troponin-positive acute coronary syndrome (ACS) within the 1 month preceding the study will be recruited. Simple randomization will be used in participant allocation. The intervention group will receive the model plate diet. The control group will be provided with routine dietary advice. Other domains, such as advice on exercise and lifestyle modification, will be equalized among patients in both the groups. The visits and evaluations will be done at recruitment (visit 0), 4 weeks, and 12 weeks after the intervention. The primary outcome will be a mean body weight reduction of 10%, and the secondary outcomes will include mean reduction of systolic and diastolic blood pressure, improvement of anthropometric parameters, and improvement of lipid profile and liver enzymes in the test group compared with the control group at 12 weeks following the plate model diet. Discussion This study protocol is designed to establish the effects of the plate model diet on modification of cardiometabolic risk factors in patients with ACS. This will also be a pioneering study designed to investigate the practicality of the model plate in local settings and in the South Asian region. Trial registration Sri Lanka Clinical Trials Registry identifier: SLCTR/2016/22. Registered on 22 September 2016 ( http://www.slctr.lk/trials/483 )

Additional file 1: of Effects of the “plate model” as part of dietary intervention on modification of selected cardiometabolic risk factors in post-myocardial infarction patients: study protocol for a randomized controlled trial

SPIRIT 2013 checklist: recommended items to address in a clinical trial protocol and related documents. (DOC 122 kb

Seroprevalence of leptospirosis in an endemic mixed urban and semi-urban setting-A community-based study in the district of Colombo, Sri Lanka.

Leptospirosis is endemic in Sri Lanka. There is a need for updated seroprevalence studies in endemic areas, to improve the understanding of disease dynamics, risk factors, control methods, and for clinical diagnosis. The cut-off titres for the microscopic agglutination test (MAT) for diagnosis of acute leptospirosis depend on community seroprevalence, and can vary based on locality and serovar. This study aimed to identify the seroprevalence, geographical determinants, and associations of seropositivity of leptospirosis in the district of Colombo in Sri Lanka, and to determine diagnostic cut-off titres for MAT in the community studied. This study utilized a stratified cluster sampling model in the Colombo district of Sri Lanka, to sample individuals living in urban and semi-urban areas. Serovar specific MAT titres were measured on recruited individuals using a panel of saprophytic (Leptospira biflexa) and 11 pathogenic Leptospira spp. serovars. Associations between environmental risk factors and MAT positivity were examined, with location mapping using GIS software. A total of 810 individuals were included. The mean age was 51.71 years (SD 14.02) with male predominance (60%). A total of 429 (53%) tested positive at a titer of 1/40 or more for the saprophytic Leptospira biflexa serovar Patoc. Pathogenic serovar MAT was positive at a titer of 1/40 or more for at least one serovar in 269 (33.2%) individuals. From the perspective of screening for clinical disease, serovar-specific cut-off titres of 1/80 for Leptospira spp. serovars Hebdomadis, Icterohaemorrhagiae, Pomona, Ratnapura and Patoc, 1/160 for serovars Pyrogenes and Cynopteri, and 1/40 for other serovars were determined, based on the 75th quartile MAT titre for each serovar. Serovar Pyrogenes (15.9%) had the highest seroprevalence, with serovars Ratnapura, Bankinang and Australis accounting for 9.9%, 9.6% and 9.3% respectively. When the proposed new cut-offs were applied, Bankinang(9.6%) Australis(9.3%), Pyrogenes(6.9%) and Ratnapura(6.9%) were the most prevalent serovars. No significant differences in seroprevalence or serovar patterns were noted between urban and semi-urban settings. Individuals seropositive for Australis, Ratnapura and Icterohaemorrhagiae were clustered around main water bodies as well as around smaller tributaries and paddy fields. Those positive for the serovar Pyrogenes were clustered around inland tributaries, smaller water sources and paddy fields. Associations of MAT positivity included high risk occupational exposure, environmental exposure including exposure to floods, bathing in rivers and lakes, using well-water for bathing, contact with stagnant water, propensity to skin injuries, presence of rats in the vicinity, and proximity to water sources. For pathogenic serovars, high-risk occupational exposure remained statistically significant following adjustment for other factors (adjusted OR = 2.408, CI 1.711 to 3.388; p<0.0001; Nagelkerke R2 = 0.546). High risk occupational exposure was determined to be independently associated with seropositivity. Baseline community MAT titres vary according to serovar, and presumably the locality. Testing against saprophytic serovars is unreliable. Thus, diagnostic MAT titre cut-offs should be determined based on region and serovar, and the use of a single diagnostic MAT cut-off for all populations is likely to result in false negatives