Risk of Collision at Sea

The maritime traffic service system (VTS) is increasingly focused and strongly developed. After a decade of operation, the VTS system in Vietnam has demonstrated its benefits, such as reducing accidents and improving ship traffic capacity. Close monitoring of objects with a high risk of environmental pollution, such as oil tankers and dangerous cargo ships, helps to reduce the risk of accidents and environmental pollution. However, the benefits brought by the VTS system have not been comprehensively evaluated. This research uses the SWOT method combined with quantitative methods to comprehensively analyze the system. The results show that the VTS system makes an important contribution to optimizing travel time, waiting time for channels, reducing support vehicles for channel clearing, and reducing emissions, with a benefit-to-cost index of more than 483%. From there, propose a direction for the development of the VTS system to contribute to the sustainable development of the Vietnamese maritime industry.

Exposure of acid aerosol for schoolchildren in metropolitan Taipei

In this study, the authors evaluated exposure to airborne polycyclic aromatic hydrocarbons (PAHs) in workers exposed to exhaust gas from cars, and they assessed the efficiency of urinary 1-hydroxypyrene as an indicator of exposure to pyrene and PAHs. The authors selected 2 groups of police who worked in 2 areas in the city of Florence: 1 group was highly exposed to high-density traffic emissions during the winter and summer of 1997, and the 2nd group experienced low exposure to traffic emissions during the same period. Ambient monitoring was achieved with personal sampling of airborne PAHs during each workshift. Eight hydrocarbons were used as indicators of pollution caused by PAHs (e.g., pyrene, benzo[a]pyrene, benzo[a]anthracene, dibenzo[a,h]anthracene). Biological monitoring was performed through dosing of 1-hydroxypyrene (pyrene metabolite) in urine samples taken at the end of each workshift. The ambient monitoring revealed that PAH concentrations were influenced by both season of sampling and varying intensities of traffic in the different areas. The median concentration of benzo[a]pyrene in winter was twice as high in the high-density traffic area as in the low-density traffic area (i.e., 4.1 ng/m3 versus 1.8 ng/m3). In summer, the high-density traffic area experienced benzo[a]pyrene concentrations that were 6 times higher than in the low-density traffic area (i.e., 1.2 ng/m3 versus 0.2 ng/m3). Benzo[a]pyrene was also correlated highly (r(s) = .92, p < .0001) with the mixture of total PAHs analyzed, thus confirming its function as a good indicator of exposure to PAHs in an urban environment. Levels of urinary 1-hydroxypyrene appeared to be generally influenced by the intensity of traffic, especially during the winter (i.e., median value in winter was 199.2 ng/gm creatinine in the high-density traffic area and 120.5 ng/gm creatinine in the low-density traffic area). An analysis of the general data revealed that 1-hydroxypyrene was, to some degree, related to pyrene, benzo[a]pyrene, and airborne total PAHs, whereas analysis of separate data for the area and the season revealed an emergence of a closer correlation during the winter in the high-traffic area. Therefore, 1 -hydroxypyrene can be considered a good biological indicator of exposure to airborne PAHs in the urban environment, especially in winter and in high-density traffic areas.

The digital transmission amongst vehicles and roadway equipment is necessary for the realization of smart transportation systems. Vehicular ad-hoc network (VANet) is an ascension field of engineering that presents brilliant transport applications, road safety, comfort and luxury to drivers. VANet protocols face many challenges because of the changing nature of vehicular ad-hoc network. VANet routing protocols perform a vital role in terms of the performance efficiency because they decide the mode of sending and receiving packets between mobile vehicular nodes. Finding suitable and efficient routing protocol is very important for the efficient implementation of VANet. The foremost objective of this research is to suggest the relevant and efficient VANet routing protocols in a high traffic density area. This research work presents a practical evaluation of the VANet topology’s features with respect to time for the high traffic situations. This evaluation incorporates the actual creation of roadway layout. An accurate traffic flow is produced by extracting run-time facts and figures from PeMS (Freeway Performance Measurement System) database and assigning this extracted information into a microscopic mobility model. To achieve our goal, we consider three routing protocols i.e., AOMDV, AODV and DSDV. The simulation results prove that the performance of AOMDV is greater in comparison to DSDV and AODV protocols in high traffic density areas. The AOMDV protocol improves overall network performance by achieving maximum throughput and minimum end to end delay.

A search for cheap and efficient method to monitor atmospheric particulates in city centres has raised new interest to measure foliar element concentrations after the role of particulate pollution for respiratory illnesses was discovered. Leaf samples of Golden dewdrop (Duranta repens L.) collected in Palermo (South of Italy) between 1998 and 2000 were analysed to study the possible use of this shrub as a passive biomonitor for atmospheric pollution in urban areas. Concentrations of Ba, Cd, Cu, Fe, Mg, Mn, Pb and Zn were determined from leaf samples collected from six sampling sites representing either (a) areas of high traffic density or (b) areas not directly affected by the city traffic (e.g. gardens). Most of the elements showed a significant temporal variation but no consistent trends could be seen, i.e. the highest (or lowest) values were not detected consistently at some particular time of the year. Furthermore temporal changes were of same magnitude in polluted versus less polluted areas; no statistically significant interaction between pollution level and collection period was detected. Pollution level (traffic density) was the primary factor to explain spatial variation only in the case of foliar Mg concentrations. On the other hand, variation in foliar concentrations between sampling sites (irrespective of the pollution level) was large. Our results suggest that particulate deposition needs to be quite high before spatial segregation can be done on the basis of foliar element concentrations.

&amp;lt;p&amp;gt;Urban Gardening has become increasingly popular globally in the past two decades as urbanites begin to recognise the benefits of growing their own food and the sense of community these gardening activities engender. These activities grow as citizens reclaim derelict land and are increasingly using roof top gardens and novel containers, providing much needed green oases in the city, concepts which are particularly popular with the &amp;amp;#8220;share&amp;amp;#8221; generation. However, many such sites are in areas of high traffic density, on brown field sites or on sites overlying landfill, as a result of their urban location. The proximity to such sites may lead to worries about the food safety and reduction of the adoption of such healthy urban gardening practices. One of the main concerns is the transfer of urban pollutants into the consumer&amp;amp;#8217;s food chain. Trace metals are one of the contaminants frequently found in urban crops and soils. Perceived concerns about the effects of these heavy metal contaminants on human health often outweigh the true risk; part of the problem is the lack of data in the urban production context. Moreover, collection of city-wide data on the health of the soil is often difficult and expensive to collect. In this project we intend to attempt to overcome these issues by recruiting citizens to conduct simple common collaborative experiments in their urban gardens, from these data we will create a city map of soil health status and providing information on potential risk of heavy metal contaminants and ways in which to mitigate those risks in an Urban Gardening context. We chose a citizen science approach in this project, not only as it will allow us to gather a wealth of data but also it will empower us to jointly generate useful information for the greater public good which can contribute towards creating green sustainable cities.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;This project will place the citizen at the heart of the experimental process in contrast to more traditional observational data collection. Using an experimental approach really exposes the citizens to the scientific process and enables them to gain tacit knowledge of how scientists overcome variance, bias and arrives at scientifically sound evidence based conclusions. As a result, citizen science can provide reassurance to the public about the rigour and process of scientific enquiry. In doing so it can inspire confidence and understanding of the nuances of political bias; putting contextual knowledge together, in learning by doing.&amp;lt;/p&amp;gt;

To improve collision risk prediction in high-traffic coastal waters and support real-time decision-making in maritime navigation, this study proposes a regional collision risk prediction system integrating the Computed Distance at Collision (CDC) method with an Adaptive Neuro-Fuzzy Inference System (ANFIS). Unlike Distance at Closest Point of Approach (DCPA), which depends on the position of Global Positioning System (GPS) antennas, Computed Distance at Collision (CDC) directly reflects the actual hull shape and potential collision point. This enables a more realistic assessment of collision risk by accounting for the hull geometry and boundary conditions specific to different ship types. The system was designed and validated using ship motion simulations involving bulk and container ships across varying speeds and crossing angles. The CDC method was used to define collision, almost-collision, and near-collision situations based on geometric and hydrodynamic criteria. Subsequently, the FIS–CDC model was constructed using the ANFIS by learning patterns in collision time and distance under each condition. A total of four input variables—ship speed, crossing angle, remaining time, and remaining distance—were used to infer the collision risk index (CRI), allowing for a more nuanced and vessel-specific assessment than traditional CPA-based indicators. Simulation results show that the time to collision decreases with higher speeds and increases with wider crossing angles. The bulk carrier exhibited a wider collision-prone angle range and a greater sensitivity to speed changes than the container ship, highlighting differences in maneuverability and risk response. The proposed system demonstrated real-time applicability and accurate risk differentiation across scenarios. This research contributes to enhancing situational awareness and proactive risk mitigation in Maritime Autonomous Surface Ship (MASS) and Vessel Traffic System (VTS) environments. Future work will focus on real-time CDC optimization and extending the model to accommodate diverse ship types and encounter geometries.

An efficient identity-based signature scheme without bilinear pairing for vehicle-to-vehicle communication in VANETs

Petroleum hydrocarbon pollution of urban topsoil in Ibadan City, Nigeria

BackgroundTraffic policemen are identified to be at a higher risk of exposure to air pollution and its contaminants such as lead. A study done prior to the introduction of unleaded petroleum in Sri Lanka revealed a mean blood lead level of 53.07 μg/dL, which was well above the Center for Disease Control defined acceptable safe levels. This study aimed to determine whether unleading of fuel has made an impact on the blood lead levels of traffic police working in an urban area with high traffic density.MethodA cross-sectional survey of 168 traffic police personnel working within Colombo city limits of Sri Lanka, a high traffic density area, was conducted. Blood lead levels of participants were measured using nitric acid, perchloric acid ashing method and atomic absorption spectrophotometry. An interviewer administered questionnaire was used for a targeted history and examination.Results and discussionMean age of the sample population was 37 years. Thirty eight percent had detectable levels of lead in blood and 24.4% of the study sample had blood lead levels above Centre for disease control defined safe limits. Sample mean was 4.82 μg/dL (95% CI 3.58-6.04), and this is a 91% overall reduction when compared to data prior to unleading. Neither symptoms nor signs of classic lead toxicity showed significant correlation with toxic lead levels.ConclusionLead poisoning though still present in the high risk traffic warden population shows a considerable reduction following unleading. The need to have a low threshold to suspect lead poisoning is highlighted by the non-specific nature of the symptoms and signs of lead poisoning and its lack of association even in those found to have elevated lead levels. Further studies are required to elucidate a cause for the prevalence of lead poisoning despite cessation of using lead as an additive in petroleum.

The initial introduction of new generation of mobile communications technologies is typically done in high traffic density areas and with high requirements for new service capabilities. This is followed by gradual further construction, which may be more or less rapid depending on the strategy of the operator. During this, a combination of new and legacy technologies will provide ubiquitous coverage of the operator network, with devices constantly moving out and out of the areas covered by the new technology. Therefore, seamless transmission between new and outdated technology is a key requirement.

Network designers expect a highly mobile, highly responsive, and quickly deployable network structure to enable communication in emergency situations. For this reason, a major research goal for emerging mobile network (mobile sensor network, mobile ad hoc network, etc.)is to achieve good coverage and robust communication performance by coordinated management of base stations or nodes. In this paper, we extend current methods to balancing cell load by taking base station mobility into account.We propose a novel distributed base station mobility strategy (DMS). We focus on a recently attractive network model where localized communication is supported by using mobile base stations (MBSs) placed on moving vehicles. In order to minimize the blocking rate in high traffic density area, the proposed strategy will lead the MBSs to suitable locations and re-share the whole traffic load. We demonstrate the convergence of this distributed mobility strategy by both theoretical analysis and numerical evaluations of realistic networks. The strategy enables each MBS to select destination efficiently and locally with limited information exchange. Compared with the traditional load balancing method based on transmit power control, the proposed algorithm has obvious advantages in reducing the dropped calls, especially with extremely uneven load distribution.

The results of a survey of air particulates at 23 sites across Jamaica for total suspended particulates (TSP), Al, Br, Cl, Na, Pb, and V, by instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF) are reported. The geometric mean of TSP values, 35 g m-3, is well within the World Health Organisation's standard of 60 g m-3 for TSP, but in areas of high vehicular traffic density the TSP values exceeded this limit. The correlation coefficient between Br and Pb concentrations in the particulates was 0.92 and the Br/Pb ratio of 0.38 compares well with a ratio of 0.39 found in commercial petrol indicating that the exhaust from vehicular traffic is the major source of Pb in atmospheric particulate matter in Jamaica.

In areas of high marine traffic density it has been necessary for IMCO to introduce traffic separation schemes to reduce the total number of encounters, and in particular the dangerous head-on encounters. It is now widely acknowledged that separation schemes can and do improve safety. However, as a side effect they unfortunately increase the number of overtaking encounters. For example the introduction of a separation scheme in the Dover Strait (with 1 per cent of ‘through rogues’) has increased threefold the proportion of potential overtaking encounters.

Nerium oleander L. (Oleander) leaves grown in Palermo city (Sicily, Italy) were collected from six sampling sites representing either areas of high traffic and urbanisation density or areas far away from traffic (e.g. city gardens). Concentration of Al, Ba, Cr, Cu, Fe, Pb, Mg, Mn, and Zn were determined in leaf samples during two years. Multivariate analysis classified the sampling sites in four groups based on the metal content in vegetal leaves in agreement with traffic and human activity site. Many elements studied (Al, Ba, Fe, Mn Mg) arise from the soil composition and others such as Cr, Cu, Pb and Zn as pollutant of the soil. On the other hand, about 30% of Al, Fe Cr, Cu and Pb originate from aerial deposition on leaves. Although the results presented should be handled with caution N. oleander can be considered as a means of assessing dust contamination in the urban environment.