Air traffic control: Ocular metrics reflect cognitive complexity

The objective of the study was to evaluate effects of complexity on cognitive workload in a simulated air traffic control conflict detection task by means of eye movements recording. We manipulated two complexity factors, convergence angle and aircrafts minimum distance at closest approach, in a multidimensional workload assessment method based on psychophysiological, performance, and subjective measures. Conflict trials resulted more complex and time-consuming than no conflicts, requiring more frequent fixations and saccades. Moreover, large saccades showed reduced burst power with higher task complexity. A motion-based and a ratio-based strategy were suggested for conflicts and no conflicts on the basis of ocular metrics analysis: aircrafts differential speed and distance to convergence point at trial start were considered determinant for strategy adoption.Relevance to industryEye metrics measurement for online workload assessment enhances better identification of workload-inducing scenarios and adopted strategy for traffic management. System design, as well as air traffic control operators training programs, might benefit from on line workload measurement.     

DYNAMIC RESOURCE ALLOCATION SCHEME UNDER TRAFFIC CONDITION IN SATELLITE SYSTEMS

As the traffic distribution in China mainland is far from uniform, a new traffic model in China mainland is presented on the basis of per-capita Gross Domestic Product (GDP) and density of population. Based on this characteristic traffic model, a new Traffic Dependent Dynamic Channel Allocation and Reservation (TDDCAR) technique is proposed, the simulation model is built, and the strategies’ performance is evaluated through computer simulation. The simulation results show that, compared to the conventional Fixed Channel Allocation (FCA), TDDCAR estimates the traffic con-ditions in every spot beam and frequently adjusts the traffic according to current traffic conditions. It has achieved a significant improvement in new call blocking probability, handover blocking probability, and fair index, particularly, in heavy traffic conditions. The building of traffic model in China mainland and the analysis of the simulation results has been a key foundation for the study of resource allocation schemes in the future.     

Ocular movements under taskload manipulations: Influence of geometry on saccades in air traffic control simulated tasks

Traffic geometry is a factor that contributes to cognitive complexity in air traffic control. In conflict‐detection tasks, geometry can affect the attentional effort necessary to correctly perceive and interpret the situation; online measures of situational workload are therefore highly desirable. In this study, we explored whether saccadic movements vary with changes in geometry. We created simple scenarios with two aircraft and simulated a conflict detection task. Independent variables were the conflict angle and the distance to convergence point. We hypothesized lower saccadic peak velocity (and longer duration) for increasing complexity, that is, for increasing conflict angles and for different distances to convergence point. Response times varied accordingly with task complexity. Concerning saccades, there was a decrease of peak velocity (and a related increase of duration) for increased geometry complexity for large saccades (>15°). The data therefore suggest that geometry is able to influence “reaching” saccades and not “fixation” saccades. © 2011 Wiley Periodicals, Inc.     

铝合金在自行车上的应用

本文介绍铝合金在交通运输方面尤其在自行车、电动车等方面的应用和发展,并指出自行车这一传统工具在国内某些城市的新用途,成为城市低碳出行的最佳选择之一,间接地为城市交通的发展提供一种节能、环保和惠民的新思路。     

基于FPGA的激光探测自适应电路设计

激光以其方向性好、亮度高、单色性好等优点使得其应用越来越广泛，但是，因其受环境条件的影响较大，特别是在沙尘、雨雪、雾霾等不同天气情况下，激光探测性能受到很大干扰，该文针对这种状况，基于 FPGA 设计了激光探测自适应电路，表明随着传感信号输入的变化，则相应的阈值门限也随之变化，使得不同阈值对噪声的抑制能力达到最佳，从而达到一个自动调节、动态平衡的效果。     

An application of OWA operators in fuzzy business diagnosis

The paper aims to develop an adjustment index based on OWA operators to enrich the results of diagnostic fuzzy models of business failure. A proposal to verify the diseases prediction accuracy of the models is also added. This allows a reduction of the map of causes or diseases detected in strategic defined areas. At the same time, these key areas can be disaggregated when an alert indicator is identified, and shows which of the causes need special attention. This application of OWA can encourage the development of suitable computer systems for monitoring companies’ problems, warn of failures and facilitate decision-making. In addition, taking Vigier and Terceño’s 2008 model as a benchmark, causes aggregation operators are introduced to evaluate alternative groupings, and the adjustment measure using approximate solutions is proposed to test the model’s prediction.The empirical estimation and the verification of the improvement proposals in a set of small and medium- sized enterprises (SMEs) in the construction industry are also presented. The functionality and the prediction capacity are thus measured and detected by monitoring key areas that warn about insolvency situations in the firm.     

Research on the energy-saving and revenue sharing strategy of ESCOs under the uncertainty of the value of Energy Performance Contracting Projects

Under the uncertainty of the value of Energy Performance Contracting Projects (EPCPs), this paper develops a revenue-sharing bargaining model between an Energy Service Company (ESCO) and an Energy-Using Organization (EU). Based on the model the paper analyzes the impacts of energy prices, risk-adjusted discount rates and accidents on the ESCO’s bargaining strategies. The research shows that the greater the probability of adverse circumstances is, the higher is the revenue share (of the EU), and the more disadvantageous is the ESCO’s position in the game. Furthermore, we design a forecast–commitment contract between an ESCO and an EU and analyze the optimal product’s energy savings commitment strategy of the ESCO to cope with uncertain energy savings and contract risk. The research illustrates that by introducing penalties and commitments, the contract can eliminate the impact of the uncertain energy savings on the contract execution to a certain extent; when the EU takes a greater commitment risk, the ESCO is willing to provide a higher commitment, thus enhancing the strategy value of the bilateral relationship and reducing the contract risk. Finally, the policy recommendations about improving shared savings contract standard, third-party energy savings measurement and verification mechanism and arbitration mechanism of EPCs are provided.     

Comprehension and acceptability of on-board traffic information: Beliefs and driving behaviour

Co-Drive on-board traffic information system is a complementary tool providing a dynamic management of transportation infrastructure and traffic as well as the diffusion of accurate real-time information about the road environment and motorists’ driving behaviour. The aim of this study was to examine drivers’ acceptability of Co-Drive by investigating the impact of traffic information provided via on-board display devices on motorists’ beliefs and behaviour.     

Balancing CapEx reduction and network stability with stable routing–virtual topology capacity adjustment (SR–VTCA)

This paper investigates the merits of the SR–VTCA (stable routing–virtual topology capacity adjustment) approach as a mechanism to find a beneficial trade-off between network stability and reduction in capital expenditures (CapEx). These are two main objectives for the entities that own the optical infrastructure, such as network operators (NOs), and those also acting as Internet service providers (ISPs). The SR–VTCA scheme is a novel approach to adapt transparent optical networks to time-varying traffic by adjusting the number of lightpaths between node pairs, while keeping the IP routing unchanged. Lightpath bundling (LB) and anycast (AS) switching are combined in SR–VTCA operation to advertise lightpath additions/removals to the IP layer as mere adjustments (increments or decrements) in the capacity, allowing to keep the IP routing stable, and thus, simplifying control plane operations. On the contrary, a fully-reconfigurable (FR) network design, where IP routing can be also modified, would increase the burden in the control plane, but at a higher CapEx reduction, since the optical infrastructure is used more efficiently. In this work, we investigate the CapEx overprovision introduced by SR–VTCA with respect to a FR scheme. In order to do this, SR–VTCA planning problem is first modeled as a MILP formulation. A heuristic procedure based on traffic domination is then proposed to solve large instances of the problem. Exhaustive experiments are conducted comparing the SR–VTCA solutions obtained by the aforementioned MILP and heuristic proposal with solutions found by other optimization methods presented in the literature to solve the FR planning problem. Finally, the results show that SR–VTCA can achieve similar results to the FR case in terms of CapEx reduction, while a huge number of IP reroutings are saved by maintaining IP stability. Thus, SR–VTCA provides an advantageous balance between CapEx overprovisioning and the control plane overhead associated with IP rerouting.     

Multinational vehicle license plate detection in complex backgrounds

Many methods for multinational License Plate Detection (LPD) have been proposed in recent times but most of them are not sophisticated enough to handle complex backgrounds. Moreover, their ability to handle various environmental and illumination conditions has been limited and still needs improvement. In this paper, we propose a novel technique to detect license plates of vehicles regardless of their color, size, and content. As the rear vehicle lights are an essential part of any vehicle, we reduce the image processing area to eliminate the complex background by detecting the rear-lights as the license plates are in a certain range of these lights. Heuristic Energy Map (HEM) of the vertical edge information in the Region of Interest (ROI) is calculated and area with the dense edges is selected using a unique histogram approach which is considered to be the license plate. The proposed algorithm is tested on 855 images from various countries including China, Pakistan, Serbia, Italy and various states of America. Experimental results show that the proposed method is able to detect license plates 90.4% of times despite of complex backgrounds in 0.25 s on average that can achieve real time performance.