Analysis of Current Sectors Based on Traffic and Geometry

This paper desc ribes an evaluation of current sectors in the continental United States using a variety of traffic and geometric metrics. Most of the metrics have been computed using real track -data. In instances where this was not possible, s imulated traffic data are use d. Statistics of these metrics are summarized for higher altitude sectors in the twenty air route tr affic control centers and in eight geographical regions . The analysis shows that most sectors have fewer than twenty aircraft and three conflicts at any giv en time. Air traff ic in higher altitude sectors consists of mostly jets that fly in a narrow range of airspeeds and altitudes. A wide variation was found in the volume, area, height, length and transit times of the sectors. Most sectors were found to be el ongated and aligned in the direction of the traffic flows. The properties of today's sectors reflect the technologies and procedures used for air traffic control. With the introduction of automation, the design of airspace partitions will not be contrained by how controllers manage traffic. However, if controllers are involved to some degree in the future system, it might be useful to account for some of the characteristics of the current sectors in the design of future airspace partitions. I. Introductio n n the current national airspace system, design of sectors have evolved over a long period of time based on incremental addition of new technologies and procedures for air traffic control. Each sector has a fixed capacity. When these capacities are exce eded by traffic demand, traffic flows are restriced to bring the demand below capacity. The concept in Ref. 1 suggests that instead of restricting tr affic , which causes delays, airspace capacity can be increased by partitioning the airspace differently. Mo tivated by this concept, s everal methods for airspace partitioning that are described in Refs. 2 through 6 have been developed. These methods use some measure of controller workload to guide the design . In the future, with increased level of automation, ai rspace design might not be guided by controller workload considerations. Depending on how different the future design is from the current design, the controller's ability to actively separate aircraft might be limited. It might be useful to carry some of t he design features of the current system into the future one, if some role for human controller is envisioned in the future air traffic control system. The motivation for computing metrics for the existing sectors is to capture some of the design features of the current sectors. Since the design of current sectors is based on the routes of flight and controller workload considerations , metrics related to controller workload can be expected to capure the design features. There are numerous traffic and geom etry metrics described in the literature that have been found to be useful for modeling controller's perception of workload and in operational error studies. 7-11 These studies are limited to sectors in few centers. A comprehensive study of sectors in all t he twenty centers is unavailable. In this paper, thirty -three traffic and geometric metrics from Ref s. 7 to 11 are computed for 364 higher al titude sectors in each of the twenty centers, and in eight geographical regions. Higher altitude sectors were chos en because the benefits of airspace partitioning are expected to be realized in these sectors first. Data presented in this paper describes the design of the current sectors and will be found to be useful for comparing the designs of future airspace partit ions

Traffic Complexity Measurement Under Higher Levels of Automation and Higher Traffic Densities

n understanding of the complexity factors that affect controller workload under higher levels of automation for conflict detection and resolution and under higher traffic densities is critical for future operations. This paper examines traffic complexity variables under higher levels of automation where the human controller is still in the loop, but is being supported by advanced conflict detection and resolution automation. The study involved two conflict resolution automation modes (i.e., trial-planning automation and advisory automation) and three traffic densities (i.e., 1X, 2X and 3X). The results indicate that under the 1X traffic condition, controller workload was the lowest with advanced levels of automation. The complexity and workload increased progressively for the 2X and 3X traffic conditions. Results also showed that several variables such as horizontal proximity, aircraft density, separation criticality index, and two degrees of freedom indices appear to be relevant complexity measures for ..

Modeling and predicting mental workload in en route air traffic control: Critical review and broader implications

Objective: We perform a critical review of research on mental workload in en route air traffic control (ATC). We present a model of operator strategic behavior and workload management through which workload can be predicted within ATC and other complex work systems. Background: Air traffic volume is increasing worldwide. If air traffic management organizations are to meet future demand safely, better models of controller workload are needed. Method: We present the theoretical model and then review investigations of how effectively traffic factors, airspace factors, and operational constraints predict controller workload. Results: Although task demand has a strong relationship with workload, evidence suggests that the relationship depends on the capacity of the controllers to select priorities, manage their cognitive resources, and regulate their own performance. We review research on strategies employed by controllers to minimize the control activity and information-processing requirements of control tasks. Conclusion: Controller workload will not be effectively modeled until controllers' strategies for regulating the cognitive impact of task demand have been modeled. Application: Actual and potential applications of our conclusions include a reorientation of workload modeling in complex work systems to capture the dynamic and adaptive nature of the operator's work. Models based around workload regulation may be more useful in helping management organizations adapt to future control regimens in complex work systems

CMS Physics Technical Design Report: Addendum on High Density QCD with Heavy Ions

This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies $\sqrt{s_{NN}}= 5.5\,{\rm TeV}$ , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction \u2014 Quantum Chromodynamics (QCD) \u2014 in extreme conditions of temperature, density and parton momentum fraction (low- x ). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low p T inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high p T hadrons which yield "tomographic" information of the hottest and densest phases of the reaction

A New Boson with a Mass of 125 GeV Observed with the CMS Experiment at the Large Hadron Collider

The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a complex scalar field thought to give mass to three of the carriers of the electroweak force-the W+, W-, and Z(0) bosons-as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1 in 3 x 10(6). The new particle is a boson with spin not equal to 1 and has a mass of about 1.25 giga-electron volts. Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle

Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

The article is the pre-print version of the final publishing paper that is available from the link below.Results are presented from searches for the standard model Higgs boson in proton–proton collisions At √s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 at 7TeV and 5.3 fb−1 at 8 TeV. The search is performed in five decay modes: γγ, ZZ, W+W−, τ+τ−, and bb. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3±0.4(stat.)±0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one