Risky Route Research Articles

Modeling Day-to-day Flow Dynamics on Degradable Transport Network.

Stochastic link capacity degradations are common phenomena in transport network which can cause travel time variations and further can affect travelers’ daily route choice behaviors. This paper formulates a deterministic dynamic model, to capture the day-to-day (DTD) flow evolution process in the presence of degraded link capacity degradations. The aggregated network flow dynamics are driven by travelers’ study of uncertain travel time and their choice of risky routes. This paper applies the exponential-smoothing filter to describe travelers’ study of travel time variations, and meanwhile formulates risk attitude parameter updating equation to reflect travelers’ endogenous risk attitude evolution schema. In addition, this paper conducts theoretical analyses to investigate several significant mathematical characteristics implied in the proposed DTD model, including fixed point existence, uniqueness, stability and irreversibility. Numerical experiments are used to demonstrate the effectiveness of the DTD model and verify some important dynamic system properties.

Asylstrømmen fra Russland til Norge i 2015: Bevisst russisk politikk?

In the autumn of 2015, 5500 migrants traveling through Russia along the “Arctic route” applied for political asylum in Norway. Some observers claimed that Russia deliberately channeled migrants towards the north with the purpose of destabilizing Norway and that Russia had changed procedures in their border zone to facilitate the wave of migrants. In this article we briefly discuss the hybrid warfare theory and assess alternative explanations that might account for the sudden increase in migrants. Detailing formal and informal practices in the Norwegian-Russian border regime we argue that Russian practices were not altered in any significant way in 2015, but that the Norwegian side had an incorrect impression of the Russian border regime being more restrictive than it really was. Finland was in a similar situation. The most convincing explanation for the wave of asylum-seekers is the self-interest of migrants who found a cheaper and less risky route. Both in Norway and Finland the border regimes were tightened as a consequence of the increased migration, however. As a result, their policies became more aligned with Russian priorities. Published: June 2016 Citation: Arild Moe & Lars Rowe (2016) «Asylstrømmen fra Russland til Norge i 2015: Bevisst russisk politikk?». Nordisk Østforum 30 [2] 80–97. http://dx.doi.org/10.17585/nof.v30.432

Connectivity reliability in uncertain networks with stability analysis

This paper treats the fundamental problems of reliability and stability analysis in uncertain networks. Here, we consider a collapsed, post-disaster, traffic network that is composed of nodes (centers) and arcs (links), where the uncertain operationality or reliability of links is evaluated by domain experts. To ensure the arrival of relief materials and rescue vehicles to the disaster areas in time, uncertainty theory, which neither requires any probability distribution nor fuzzy membership function, is employed to originally propose the problem of choosing the most reliable path (MRP). We then introduce the new problems of α-most reliable path (α-MRP), which aims to minimize the pessimistic risk value of a path under a given confidence level α, and very most reliable path (VMRP), where the objective is to maximize the confidence level of a path under a given threshold of pessimistic risk. Then, exploiting these concepts, we give the uncertainty distribution of the MRP in an uncertain traffic network. The objective of both α-MRP and VMRP is to determine a path that comprises the least risky route for transportation from a designated source node to a designated sink node, but with different decision criteria. Furthermore, a methodology is proposed to tackle the stability analysis issue in the framework of uncertainty programming; specifically, we show how to compute the arcs’ tolerances. Finally, we provide illustrative examples that show how our approaches work in realistic situation.

The role of Body Mass Index in child pedestrian injury risk

The goal of the current investigation was to examine obesity as a potential risk factor for childhood pedestrian injury. A racially diverse sample of 7- and 8-year-old children completed a road-crossing task in a semi-immersive virtual environment and two pedestrian route selection tasks. Multiple linear regression analyses revealed that children with a higher Body Mass Index (BMI) waited less before crossing, had a smaller temporal buffer between themselves and oncoming traffic while crossing, and had more collisions with traffic. Girls were more cautious than boys when crossing the virtual roadway. Unlike the results from the virtual road-crossing task, BMI was not associated with risky route selection. Instead, race emerged as the strongest predictor, with African–American children selecting riskier routes for crossing. Together, these findings suggest overweight and obese children may be at increased risk for pedestrian injury. The discussion considers explanations for why obese children may exhibit riskier road-crossing behavior.

Travelers’ Risk-Taking Behaviors in Day-to-Day Dynamic Evolution Model

Uncertainties often exist in traffic systems because of interday route flow swapping and intraday road capacity degradation. These uncertainties obviously affect the traveler’s individual route adjustment behavior and the corresponding network traffic dynamic evolution at an aggregate level. Seeking to give a more realistic description of traffic dynamics, this study extends the existing day-to-day (DTD) model by considering both travelers’ study of uncertain travel time and travelers’ choice of risky routes. In the proposed model, an exponential-smoothing filter is introduced to describe travelers’ study of uncertain travel time. Meanwhile, on-time arrival probability is used to model travelers’ dynamic adjustment to their reference travel time (RTT). Under the framework of cumulative prospect theory, the perceived stochastic route travel time and the RTT are both integrated into a unified prospect value function to reflect travelers’ perception of route attractiveness. On this basis, a logit model is applied to describe travelers’ stochastic route choice behaviors. The proposed model’s several mathematical properties, including fixed-point existence, uniqueness, and stability, are also investigated through theoretical analyses. Numerical examples are used to illustrate the applications of the DTD model and verify some important dynamic system properties.

Crime concentration theory

A range of concepts and lexicon of terms denote crime’s tendency to concentrate. The most established are repeat offending, repeat and near repeat victimization, geographical hotspots, and hot products. Complementary terms include hot dots, hot places, hot targets, super-targets, risky facilities, risky routes, crime sprees and spates. This study charts the relationships, offers a potentially unifying concept and examines the causal mechanisms by which crime becomes concentrated. It is concluded that further effort to integrate concepts and explanations relating to concentrations of crime may provide insights useful to theory, policy and practice.

Deadly migrant trafficking trade by sea and restrictive service trade by the WTO

Purpose– The purpose of this paper is to examine one of the most pressing global challenges, the ongoing migrant trafficking across sea, from international trade law and policy perspective. It identifies global poverty as one of the underlying causes of such trafficking. It argues that restrictive trade in labour-intensive services of the World Trade Organization (WTO) contributes to and sustains poverty in many migrant producing countries. Chronic unemployment in poor countries with surplus manual workforce renders these workers bewildered to survive in a jobless and incomeless home markets. Non-liberalization of movements of natural persons under General Agreement on Trade in Services (GATS) Mode 4 prevents legal cross-border delivery of labours. Restrictive trade in agriculture has but aggravated their marginalized plight. It is this poverty trap that pushes workers, lured by smugglers, to take risky migration routes for better life in countries with labour shortages.Design/methodology/approach– The paper adopts a blend approach of theoretical and applied aspects of international trade law and policy, which is interpreted and applied to a fact situation of contemporary challenge of migrant trafficking by sea.Findings– This paper establishes a nexus between restrictive Mode 4 trade and its implications for poverty-induced migration trafficking trade. It suggests a palatable trade law and policy-based reform response for the WTO to ameliorate poverty and migration trafficking trade concurrently through the creation of legal channels for the cross-border delivery of labours by liberalizing Mode 4 trade in a manner beneficial for developed countries as well.Originality/value– Its value lies in its contribution to maximize multi-lateral trade liberalization for the benefit of all countries, social inclusion and economic emancipation of the disadvantaged, which would minimize global poverty.

Trans-Gulf of Mexico loop migration of tree swallows revealed by solar geolocation

Abstract One of the greatest feats of avian migration is the non-stop crossing of extensive areas of inhospitable habitat such as deserts and seas. Differences in spring and autumn migration routes have been reported in species that cross such barriers, and are thought to have evolved in response to seasonal variation in prevailing wind direction. We tested the hypothesis that migration routes vary seasonally with respect to the Gulf of Mexico in the tree swallow Tachycineta bicolor using solar geolocators attached and retrieved at 4 breeding sites in central North America. We found that 100 % of birds (n = 10) made a trans-Gulf flight of >850 km from Louisiana south to their wintering grounds in the Yucatan Peninsula in 12–36 hours, achieving minimum ground speeds as high as 32 m/s. Although most days during autumn migration were characterized by unfavorable headwinds blowing to the northwest, migration over the Gulf mostly occurred on days with strong winds blowing to the south. In contrast, in 8 of 9 (88 %) birds on spring migration returned from the wintering grounds towards Louisiana following a clockwise loop pat tern flying over land to the west around the Gulf. During this spring period there were few days with prevailing winds from the south to assist northward migration. Results suggest that, despite being up to three times further (ca. 2,700 km), a coastal cir- cum-Gulf spring migration represents the less risky route when wind conditions are not favorable. These findings also help to re solve a long-standing dispute in the literature concerning migration patterns between the US Gulf coast and Mexico, and provide insight into the factors shaping migration strategies of small songbirds migrating across large bodies of water.

Dynamic Route Choice Based on Prospect Theory

Traveller route choice behaviour is influenced by many uncertain factors, which include both outer stochastic factors from road network and inner factors from traveller psychology. Traveller route choice behaviour is dynamic in practical travel process, namely traveller can change route on the way. Considered the characteristics of bounded rationality in human decision making process and change of route choice on the way, a dynamic route choice model is established based on prospect theory, and the method of dynamic route choice which is more suitable to human thinking habits and actual travel characteristics is proposed in this paper. The method allows the traveller to adjust the route according to road situation at any time. Decision making process reflects that the influence of traveller reference point on the decision result. Reference point changes with the situation of road sections passed. The examples are given to verify the validity and explain application of the method. The result shows that traveller can change route on the way when he meet congestion on the section passed, and if traveller's psychological expected time can not be met, he will choose risky route, by which the probability of congestion is higher. The method describes traveller route choice behaviour process better and reflects the true situation of road network. It is beneficial to predict traveller behaviours and changes of traffic network situation, and have certain guiding significance for traffic network planning and traffic intelligent control.

Regret theory-based route choices and traffic equilibria

This article studies route choices and traffic equilibria when travel times are risky, and travellers are risk averse and regret averse. It is shown how regret theory, being one of the most popular contenders of expected utility theory throughout the social sciences, can be applied to model risky route choices by means of an expected modified utility function. Subsequently this function is used to study numerically how risk aversion and regret aversion jointly determine equilibrium outcomes in a simple binary route choice situation. It is found that increasing levels of regret aversion lead to equilibrium shifts towards routes whose mean travel time is low, routes that are less risky and especially routes whose worst-case travel time is low compared to that of the competing route. Furthermore, risk aversion and regret aversion are found to reinforce each other's impact on equilibrium towards a situation where safer routes are preferred over riskier (but faster) ones.

Towards a decision support system, application: itinerary road modification for road transport of hazardous materials

In the risk classification, road transport of hazardous materials is one of the major technological risks. In fact, their transport exposes the population to pollution, explosion and fire which could lead to wildlife catastrophic impacts. The aim of the current study is to identify the least risky routes in Oran urban areas, and define first a mapping of dangerous roads, based on a decision support system. Also, using complementary methods issued from systemic approach of hazard science, we analyse the security degree of these roads.

The roles of gender, age and cognitive development in children's pedestrian route selection

Thousands of American children under the age of 10 years are injured annually as pedestrians. Despite the scope of this public health problem, knowledge about behavioural control and developmental factors involved in the aetiology of child pedestrian safety is limited. The present study examined the roles of gender, age and two aspects of cognitive development (visual search and efficiency of processing) in children's safe pedestrian route selection. Measures of cognitive functioning (visual search and efficiency) and selections of risky pedestrian routes were collected from 65 children aged 5-9 years. Boys, younger children and those with less developed cognitive functioning selected riskier pedestrian routes. Cognitive functioning also subsumed age as a predictor of risky route selections. Our findings suggest developmental differences, specifically less developed cognitive functioning, play important roles in children's pedestrian decision making. Directions for future examination are discussed.

Evidence is still required for treatment as prevention for riskier routes of HIV transmission

Evidence is still required for treatment as prevention for riskier routes of HIV transmission

A key event in survival

The parasitic microorganism Trypanosoma brucei evades recognition by its host's immune system by repeatedly changing its surface coat. The switch in coat follows a risky route, though: DNA break and repair.

The Contaminating Influence of Display Size on Flight Control, Risk Assessment, and Route Selection

The present experiment was designed to examine the effect of display size on distance estimates used for flight control and in assessing risk for route selection. Sixteen pilots were asked to select and fly along a route using integrated hazard and primary flight displays. Display size was manipulated by altering the physical size of a two-dimensional display and through axis compression in a three-dimensional display. Display minification resulted in poorer flight control. When the display was enlarged, pilots were found to overestimate the distance from the flight path to impending hazards and subsequently choose riskier routes. Pilots also exhibited greater confidence in their route choices with the large display, even though their choices were more dangerous. Results suggest that display size must be considered when designing displays for spatial tasks.

Solar hydrogen peroxide

The fact that the pulp and paper industry has moved to safer bleachers gives hydrogen peroxide a rebirth in both industrial and academic circles. Although H 2 O 2 is environmentally acceptable, its manufacture is a risky route because it involves hazardous chemicals (e.g. anthraquinone). At present, small-scale, on site processes for its production are of increasing interest because of the cost and hazards associated with the transport and handling of concentrated hydrogen peroxide. One of these processes is hydrogen peroxide production by oxygen reduction on a carbon cathode. In this work the feasibility of hydrogen peroxide production by reducing oxygen on a three-dimensional carbon cathode, using solar energy to drive electrochemical reactions, is demonstrated. Hydrogen peroxide possesses wide industrial applications; among them are wastewater treatment and energy production. An appropriated mixture of hydrogen peroxide and Fe(II) produces a strong oxidant (OH ) that can be employed to decolorize industrial effluents. A feasible approach to oxidize toxic organic molecules by means of oxygen reduction on a carbon cathode and the production of Fe(II), simultaneously, using an iron anode is presented here. By changing the anode material (e.g. platinum), hydrogen peroxide can be accumulated to a desired concentration and then used in an aluminum/H 2 O 2 battery. This approach is briefly discussed here as well.

M. George Craford [biography

The author presents a biography of M. George Craford, the inventor of yellow LEDs. His academic achievements, career history, and personal details reveal an adventurous heart which often urges this inventor along risky routes.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Risk and Effort Measures of Fatigue

A method of measuring fatigue is suggested in which alternative routes, requiring different amounts of effort, lead to different probabilities of success or failure. An experiment designed to investigate a task which has these features shows it sensitive to the fatigue generated by a synthetic work battery. Fatigued Ss shifted their choices towards easier, riskier routes, compared with their own earlier performance and with that of a control group; they also showed an increased error rate on a subsidiary measure. In a second experiment, measurements on the task were shown to correlate with self-rated fatigue.