1,722,976 research outputs found
CTAS data analysis program
Get PDFThe analysis program (AN) is specifically designed to produce graphic and tabular information to aid in the design and checkout of the Center TRACON Automation System (CTAS). To best reveal CTAS operation and possible problems, data are plotted in many different ways both in detail and summary form. AN has been designed to analyze both radar surveillance data and output data from CTAS. AN has been extensively used to debug and refine CTAS. It is also being used in the field to monitor and assess CTAS performance. AN is continuously refined to keep up with changing needs. The present version of AN grew out of analysis of Denver Center data. However, the AN software has been written to be adaptable to any other facility Center or TRACON. Presently, one can select Denver Stapleton, Denver International, Dallas/Fort Worth International Airport, and Dallas Love Field
Managed Futures as a Portfolio Diversification Instrument
Get PDFThe author analyses one type of hedge funds styles – managed futures and shows that they are developing dynamically. Their correlation and rates of return are compared with other asset classes in order to prove that these funds are worth considering to be incorporated into traditional investment portfolios.hedge funds,asset classes,investment portfolios.
Groundspeed filtering for CTAS
Get PDFGround speed is one of the radar observables which is obtained along with position and heading from NASA Ames Center radar. Within the Center TRACON Automation System (CTAS), groundspeed is converted into airspeed using the wind speeds which CTAS obtains from the NOAA weather grid. This airspeed is then used in the trajectory synthesis logic which computes the trajectory for each individual aircraft. The time history of the typical radar groundspeed data is generally quite noisy, with high frequency variations on the order of five knots, and occasional 'outliers' which can be significantly different from the probable true speed. To try to smooth out these speeds and make the ETA estimate less erratic, filtering of the ground speed is done within CTAS. In its base form, the CTAS filter is a 'moving average' filter which averages the last ten radar values. In addition, there is separate logic to detect and correct for 'outliers', and acceleration logic which limits the groundspeed change in adjacent time samples. As will be shown, these additional modifications do cause significant changes in the actual groundspeed filter output. The conclusion is that the current ground speed filter logic is unable to track accurately the speed variations observed on many aircraft. The Kalman filter logic however, appears to be an improvement to the current algorithm used to smooth ground speed variations, while being simpler and more efficient to implement. Additional logic which can test for true 'outliers' can easily be added by looking at the difference in the a priori and post priori Kalman estimates, and not updating if the difference in these quantities is too large
Assessment of CTAS ETA prediction capabilities
Get PDFThis report summarizes the work done to date in assessing the trajectory fidelity and estimated time of arrival (ETA) prediction capability of the NASA Ames Center TRACON Automation System (CTAS) software. The CTAS software suite is a series of computer programs designed to aid air traffic controllers in their tasks of safely scheduling the landing sequence of approaching aircraft. in particular, this report concerns the accuracy of the available measurements (e.g., position, altitude, etc.) that are input to the software, as well as the accuracy of the final data that is made available to the air traffic controllers
P158: Sensitivity analysis of CTAS temperature modifier in the emergency department
No full textIntroduction: The importance of early recognition and treatment of Sepsis has been emphasized over the last several years. In an attempt to better prioritize these patients, the Canadian Triage and Acuity Scale (CTAS) revised the adult temperature modifier after 2008 to define fever as 38.0C or higher and apply SIRS criteria, appearance and immunocompromise to assign a CTAS level of 2, 3, or 4. Prior to 2008, the fever threshold was defined as 38.5C and SIRS criteria were not included. This study looks to see if these changes increased the sensitivity of the temperature modifier. Methods: This study is a retrospective cohort analysis of patients presenting with a temperature of <36.0C or >38.0C to six Edmonton-area EDs in calendar years 2008 (n=26181) and 2012 (n=51622). Outcomes of interest included the temperature modifier predicted score and the actual assigned CTAS score. Data was extracted from the HASS/iSoft EDIS database including: presenting complaint, vital signs, CTAS score, and applied CTAS modifier to generate a before and after comparison of the actual and theoretical impact of temperature modifier revisions on the CTAS score, for both time periods. Results: Applying the pre-2008 temperature modifier to the 2008 patient cohort assigned 11.5% to CTAS 2, 39.8% to CTAS 3, and 33.3% to CTAS 4. Applying the post-2008 revised temperature modifier assigned 22.2% CTAS 2, 41.9% CTAS 3, and 27.6% CTAS 4. Carrying out the same analysis on the 2012 patients pre- results were 12.4% CTAS 2, 46.4% CTAS 3, 30.2% CTAS 4; and the post results were 21% CTAS 2, 47.7% CTAS 3, and 25% CTAS 4. Differences between pre- and post-results were statistically significant (p<0.0001) in both years. The actual triage scores in 2012 were 18.7% CTAS 2 indicating the temperature modifier was not always correctly applied and 50.6% CTAS 3 as other modifiers were sometimes applied. Conclusion: There was a significant increase in sensitivity following the post 2008 revisions to the CTAS temperature modifier when applied to two large ED patient cohorts. The differences between theoretical and actual CTAS scores was less dramatic as nurses were able to apply other first order or special modifiers to assign an appropriate score. Further analysis will be carried out to determine the impact of the temperature modifier revisions on time to antibiotic and admission rates.</jats:p
Field evaluation of flight deck procedures for flying CTAS descents
No full texthttps://doi.org/10.21949/14036761997PDFTech ReportField studiesField testsFlight decksAir pilotsDescentProceduresAcceptanceData collectionQuestionnairesCTAS Descent AdvisorCenter TRACON Automation SystemDenver International AirportDescent clearanceAmes Research CenterPalmer, EverettCrane, BarryJohnson, NancySmith, NancyFeary, MichaelCashion, PatriciaGoka, TsuyoshiGreen, SteveSanford, BeverlyAmes Research CenterSan Jose State University FoundationSterling Software, Inc.NTL-AVIATION-Air Traffic ControlUS Transportation CollectionFlight deck descent procedures were developed for a field evaluation of the CTAS Descent Advisor conducted in the fall of 1995. During this study, CTAS descent clearances were issued to 185 commercial flights at Denver International Airport. Data collection included questionnaire responses obtained from participating pilots and observations recorded in the cockpit during CTAS descents. Results indicate pilots' general acceptance of the procedure. Several problems were uncovered regarding clearance understanding, readbacks, and theacceptability of top of descent point and descent speed clearances in a few situations. This paper describes the descent procedures and phraseology developed to support the field test and presents the nature of the problems encountered.84
Citizens and CTAs
No full textAdoption of tracking applications by citizens: minor cultural differences, many common points The third part addressed the citizens' point of view. The multinomial analysis of the factors influencing the adoption of a CTA highlights, in the three countries, the importance of four dimensions: socio-demographic characteristics, trust, social influence and sensitivity to the pandemic. There is also a correlation between CTAs adoption and following instructions on testing and isolation, as we..
The Performance Persistence, Flow and Survival of Systematic and Discretionary Commodity Trading Advisors (CTAs)
Get PDFThis thesis studies the performance, performance persistence, survival and flow of Commodity Trading Advisors, also known as CTAs or Managed Futures Funds. One of the main contributions of this thesis is the novel classification of CTA strategies. This is
obtained by hand-collecting information frequently by directly contacting the funds in
the database. I thus identify two main trading styles: Systematic and Discretionary
CTAs which are the main focus of this thesis. I further separate Systematic CTAs
into trend-followers with differing trading horizon. This novel dataset allows me to reconsider
many hitherto studied issues in the CTA space with an application to these
sub-strategies.
The first section investigates the differences in mortality between Systematic and
Discretionary CTAs, over the longest horizon than of any in the literature. A detailed
survival analysis over the full range of CTA strategies is provided. Systematic CTAs
have a higher median survival than Discretionary CTAs, 12 vs. 8 years. I hand collect
information on reasons for exit from the database. I propose new filters that will better
identify real failures among funds in the graveyard database. Separating graveyard
funds into real failure I re-examine the attrition rate of CTAs. The real failure rate
is 11.1%, lower than the average yearly attrition rate of 17.3% of CTAs. The effect of
various covariates including several downside risk measures is investigated in predicting
CTA failure. Controlling for performance, HWM, minimum investment, fund age and
lockup, funds with higher downside risk measures have a higher hazard rate. Compared
to other downside risk measures, the volatility of returns is less able to predict failure.
Funds that receive larger inflows are able to survive longer than funds that do not. Large Systematic CTAs have the highest probability of survival.
The second part studies the performance and performance persistence of Systematic
and Discretionary CTAs. Controlling for biases, after fees the average CTA is able to
add value. These results are strongest for large Systematic CTAs. I extend the sevenfactor
model of Fung-Hsieh (2004a) and find that this model is better able to explain the
returns of Systematic rather than Discretionary CTAs. I find three structural breaks in
the risk loadings of CTAs different to hedge fund breaks: September 1998, March 2003
and July 2007. Using these breaks I show that systematic CTAs were able to deliver
significant alpha in every sub-period. I also find evidence of significant performance persistence.
However, these findings are heavily contingent on the strategy followed: the
persistence of Discretionary CTAs is driven by small funds whereas large funds drive the
performance persistence of Systematic funds. These results have important implications
for institutional investors who face capital allocation constraints. They also suggest that
contrary to the previous findings, the CTA industry does not appear to be heading towards
zero alpha.
The final section looks at the relationship between fund-flows and performance. Investors
chase past performance, the fund- flow -performance is significant and concave for
some strategies. Although there is some long-term performance persistence of Systematic
funds with the highest inflows, there is no smart money effect in the CTA literature.
I find no evidence of capacity constraints among Systematic CTAs. Investors are thus
not able to smartly allocate funds to future best performers and take full advantage of
the liquidity that CTAs offer.Open Acces
Faktor yang Berhubungan dengan Ketepatan Pelaksanaan Triase Modern Canadian Triage Acquity System (CTAS)
Get PDFSome patients who visit the Emergency Department (IGD) are not in an emergency condition, one way to sort it out is by triage. There are still many hospitals that are not appropriate in implementing triage, increasing the risk of death and disability of emergency patients. The purpose of this study was to determine the factors related to the accuracy of the implementation of modern triage CTAS. This research was conducted at the IGD of Bengkalis Regional Hospital. The total population is 20 emergency room nurses, with sampling using the total sampling technique. The analysis used is frequency distribution and chi square statistical test. The results of this study concluded that: Ada significant relationship between the level of knowledge of nurses and the accuracy of the implementation of the Modern Triage of the CTAS system (p value 0.002); Ada significant relationship between nurse skills and the accuracy of the implementation of the Modern Triage of the CTAS system (p value 0.011); Ada significant relationship between the perception of nurse workload and the accuracy of the implementation of the Modern Triage of the CTAS system (p value 0.00 0); Ada significant relationship between the length of work of the nurse and the accuracy of the implementation of the Modern Triage of the CTAS system (p value 0.003); Asignificant relationship between nurse training and the accuracy of the implementation of the Modern Triage CTAS system (p value 0.033). This study recommends improving the competence of all emergency room nurses, particularly through BTCLS training and modern triage of the CTAS system.Sebagian pasien yang berkunjung ke Instalasi Gawat Darurat (IGD) dalam kondisi tidak gawat darurat, salah satu cara untuk memilahnya adalah dengan triase. Masih banyak rumah sakit yang belum tepat dalam menerapkan triase, sehingga meningkatkan resiko kematian dan kecacatan pasien gawat darurat. Tujuan penelitian ini adalah untuk mengetahui faktor-faktor yang berhubungan dengan ketepatan pelaksanaan triase modern CTAS. Penelitian ini dilakukan di IGD RSUD Bengkalis. Jumlah populasi 20 orang perawat IGD, dengan pengambilan sampel menggunakan teknik total sampling. Analisis yang digunakan adalah distribusi frekuensi dan uji statistik chi square. Hasil penelitian ini menyimpulkan bahwa: Ada hubungan yang signifikan antara tingkat pengetahuan perawat dengan ketepatan pelaksanaan Triase Modern sistem CTAS (p value 0,002); Ada hubungan yang signifikan antara keterampilan perawat dengan ketepatan pelaksanaan Triase Modern sistem CTAS (p value 0,011); Ada hubungan yang signifikan antara persepsi beban kerja perawat dengan ketepatan pelaksanaan Triase Modern sistem CTAS (p value 0,000); Ada hubungan yang signifikan antara lamanya bekerja perawat dengan ketepatan pelaksanaan Triase Modern sistem CTAS (p value 0,003); Ada hubungan yang signifikan antara pelatihan perawat dengan ketepatan pelaksanaan Triase Modern sistem CTAS (p value 0,033). Penelitian ini merekomendasikan agar meningkatkan kompetensi seluruh perawat IGD, khususnya melalui pelatihan BTCLS dan triase modern sistem CTAS
- …
