CDF Values Research Articles

The Impact of the Covid – 19 Pandemic on Runway Service Life

Government policies that carry out large-scale social restrictions during the Covid-19 period have had an impact on reducing air traffic both for landings and takeoffs, which will have an impact on the life of runway services. Service life is the strength of road pavement in standing the repetition of permit loads before experiencing failure, by knowing that the service life can be directly used to determine the right time for runway maintenance. The purpose of this research is to determine the impact of the Covid-19 pandemic on the life of runway services. The method used in this research is the FAA method with the help of FAARFIELD software, this software calculates the service life based on the CDF value of each aircraft. The data used is secondary data in the form of aircraft type data, CBR ground, and existing pavement data. From the results of the research, it is known that the COVID-19 pandemic has a positive impact on the life of runway service by increasing the life of runway service by 4 years, where in the condition of covid-19 conditions it has a CDF value of 0.20 with a service life of 19 years and in normal conditions the CDF value is 0.22 with a service life of 15 years. The results of this research contribute to decision-making in carrying out maintenance and repairs on the runway of Soekarno Hatta International Airport so that the runway can operate sustainably in accordance with performance requirements throughout the life of the plan, to maintain flight safety and comfort.

Comparative Study of Airport Layer Thickness Planning Between US Army Corp Graphical Method and Federal Aviation Administration (FAA) PCN-ACN and PCR-ACR Method

Airport pavement is designed following the US Corporation of Engineers method or better known as the California Bearing Ratio (CBR) method and the FAA (Federal Aviation Administration) method which issues regulations for calculating airport pavement structures, namely AC (Advisory Circular) 150_5320_6D which same as the method CBR. In 2021, the FAA issued a standard for calculating airport pavement structures, namely AC (Advisory Circular) 150_5320_6G which uses the FAARFIELD assistance program. The difference in pavement thickness is at most 7.6 cm, on the flexible pavement type base course. In the FAARFIELD Auxiliary Program, all aircraft loads are taken into account as a contributor to pavement damage indicated by the CDF value that can accommodate aircraft loads, in contrast to the graphical method where aircraft are converted to design aircraft. The thickness of the base course using the graphical method is greater than that of the FAARFIELD Assistance Program, this is because when performing calculations, the initial base course value is the minimum value based on the minimum base course table for the use of top foundation layer material (AC No.150_5320_6G). The thickness of the surface course pavement is the same according to FAA provisions for the critical thickness of the surface course which is 4 in or 102 mm.

EVALUASI TEBAL PERKERASAN PADA RUNWAY BANDARA SYUKURAN AMINUDDIN AMIR LUWUK BERDASARKAN CUMULATIVE DAMAGE FAILURE

Air transportation is a mode of transportation still quite in demand, although recently there has been a decline in passengers. Syukur Aminuddin Amir Luwuk Airport belongs to the category of Class II Domestic Airport with airside facilities, a Runway with a size of 2,250 m x 45 m, a Taxiway 60 m x 18 m, and an Apron with a size of 315 x 15 m. The operation of several types of aircraft with a larger capacity occurs due to the increase in the number of passengers every year. An increase in the number of passengers will certainly have an impact on the number of aircraft movements, it is necessary to analyze how to determine the thickness of the runway pavement which is influenced by the type of aircraft that will operate based on the subgrade conditions that are there using the FAARFIELD method. The results of the evaluation on the thickness of the runway pavement which has a CBR value of 15%, with a pavement thickness of 215 mm for HMA Surface, 152 mm for Crushed Aggregate, and 200 mm for Uncrushed Aggregate with a service life of 20 years in 2040 it was found that the Subgrade CDF value was 0.00 and the HMA CDF of 0.86. The test results with FAARFIELD software change the pavement thickness for the base layer to 152 mm (minimum value) from the value of 100 mm. So planning the thickness of the pavement requires an additional layer of 52 mm.

The constancy of chemical weathering intensity on hillslopes in the arid to semiarid Qilian Mountains, NE Tibetan Plateau

Quantifying the relationship between the chemical weathering and denudation rates of active orogenic belts over a range of climates is the key to addressing the controversy over the uplift-weathering hypothesis. However, studies have focused on warm and humid environments and have not examined cold and arid environments. Here, we present a new dataset of the chemical depletion fraction (CDF: ratio of the chemical weathering rate to the total denudation rate) across the arid to semiarid Qilian Mountains on the northeastern Tibetan Plateau, where the uplift-weathering hypothesis has been proposed. We selected 60 points from 12 catchments in the middle Qilian Mountains. At each point, we collected three samples (soil, saprolite, and bedrock samples) and calculated the CDF values based on their Zr concentrations. We found no clear correlation between the CDF and climatic factors (temperature, precipitation, and normalized difference vegetation index (NDVI)), topographic factors (slope and local relief), and denudation rate. The calculated chemical weathering rates, nevertheless, are positively correlated with precipitation, NDVI, and denudation rate, and negatively correlated with temperature. This result indicates that the Qilian Mountains are under supply-limited conditions, even at high denudation rates (>800 t km−2 y−1). We speculate that low temperatures (<0 °C) could intensify near-surface chemical weathering by promoting the physical breakdown of the bedrock and increasing soil water availability. This mechanism causes a compensation effect maintaining the supply-limited conditions in landscapes with high denudation rates. Combing a worldwide dataset regarding the correlations between CDF and climatic factors and denudation rates, we argue that intensified denudation since the late Cenozoic contributed to global cooling.

Changing patterns in electroweak precision fits with new color-charged states: Oblique corrections and the W -boson mass

The recent measurement by the CDF Collaboration of the $W$ boson mass is in significant tension with the Standard Model expectation, showing a discrepancy of seven standard deviations. A larger value of $m_W$ affects the global electroweak fit, particularly the best-fit values of the Peskin-Takeuchi parameters $S$, $T$ (and perhaps $U$) that measure oblique corrections from new physics. To meet this challenge, we propose some simple models capable of generating non-negative $S$ and $T$, the latter of which faces the greatest upward pressure from the CDF measurement in scenarios with $U=0$. Our models feature weak multiplets of scalars charged under $\mathrm{SU}(3)_{\text{c}} \times \mathrm{U}(1)_Y$, which cannot attain nonzero vacuum expectation values but nevertheless produce e.g. $T \neq 0$ given some other mechanism to split the electrically charged and neutral scalars. We compute the oblique corrections in these models and identify ample parameter space supporting the CDF value of $m_W$.

Heavier W boson, dark matter, and gravitational waves from strings in an SO(10) axion model

Inspired by the recent determination of the $W$-boson mass by the CDF collaboration, we revisit an $SO(10)$ axion model in which a scalar $SU(2{)}_{L}$ triplet field with zero hypercharge is known to acquire a nonzero vacuum expectation value (VEV) through its mixing with the Standard Model Higgs doublet. The triplet VEV provides a sizable contribution to the $W$ mass, which helps in significantly lowering the $7\ensuremath{\sigma}$ discrepancy between the Standard Model prediction and the higher CDF value for ${m}_{W}$. We show that the relatively light triplet mass ($\ensuremath{\sim}(1--50)\text{ }\text{ }\mathrm{TeV}$) is compatible with gauge coupling unification and observable proton decay. An unbroken ${Z}_{2}$ gauge symmetry, coupled with the presence of two fermionic 10-plets required to resolve the axion domain wall problem means that both axions and a stable intermediate mass ($\ensuremath{\sim}{10}^{9}--{10}^{10}\text{ }\text{ }\mathrm{GeV}$) fermion are plausible dark matter candidates. We also display the gravitational wave spectrum from the intermediate scale topologically stable cosmic strings predicted by the model.

New physics effects on the W-boson mass from a doublet extension of the SM Higgs sector

Recently, the CDF collaboration has reported a new precision measurement of the W-boson mass, MW, showing a large deviation from the value predicted by the Standard Model (SM). In this paper, we analyse possible new physics contributions to MW from extended Higgs sectors. We focus on the Two-Higgs-Doublet Model (2HDM) as a concrete example. Employing predictions for the electroweak precision observables in the 2HDM at the two-loop level and taking into account further theoretical and experimental constraints, we identify parameter regions of the 2HDM in which the prediction for MW is close to the new CDF value. We assess the compatibility of these regions with precision measurements of the effective weak mixing angle and the total width of the Z boson.

Modelling the effect of catena position and hydrology on soil chemical weathering

Abstract. The sensitivity of chemical weathering to climatic and erosional forcing is well established at regional scales. However, soil formation is known to vary strongly along catenas where topography, hydrology, and vegetation cause differences in soil properties and, possibly, chemical weathering. This study applies the SoilGen model to evaluate the link between the topographic position and hydrology with the chemical weathering of soil profiles on a north–south catena in southern Spain. We simulated soil formation in seven selected locations over a 20 000-year period and compared it against field measurements. There was good agreement between simulated and measured chemical depletion fraction (CDF; R2=0.47). An important variation in CDF values along the catena was observed that is better explained by the hydrological variables than by the position along the catena alone or by the slope gradient. A positive trend between CDF data and soil moisture and infiltration and a negative trend with water residence time was found. This implies that these hydrological variables are good predictors of the variability in soil properties. The model sensitivity was evaluated with a large precipitation gradient (200–1200 mm yr−1). The model results show an increase in the chemical weathering of the profiles up to a mean annual precipitation value of 800 mm yr−1, after which it drops again. A marked depth gradient was obtained for CDF up to 800 mm yr−1, and a uniform depth distribution was obtained with precipitation above this threshold. This threshold reflects a change in behaviour, where the higher soil moisture and infiltration lead to shorter water transit times and decreased weathering. Interestingly, this corroborates similar findings on the relation of other soil properties to precipitation and should be explored in further research.

Comparing distributions by multiple testing across quantiles or CDF values

We first show that one-sample and two-sample Kolmogorov–Smirnov tests may be interpreted as multiple testing procedures, nonparametrically testing equality at each point in the distribution with strong control of the finite-sample familywise error rate. Second, we provide an alternative procedure that distributes power across the distribution more evenly than the Kolmogorov–Smirnov test, which suffers low sensitivity to tail deviations. Third, we provide a formula for near-instant one-sample computation. Fourth, we improve power with stepdown and pre-test procedures. Finally, we extend our results to conditional distributions and regression discontinuity designs. Simulations, empirical examples, and code are provided.

Wawasan mengenai sistem peringatan dini kekeringan di Indonesia

Drought is often categorized as a natural disaster, which receives less attention compared to flood, earthquake, and landslide due to its slow development characteristic. However, the loss due to drought events especially for farmers is comparable with other hazards. To reduce the impact of droughts, a drought early warning system with a lead time of several months ahead is needed. This paper, therefore, exploits the insight of drought early warning system that can be developed in Indonesia. Results show that drought analysis to calculate the forecasted drought severity can be separated into two algorithms. First algorithm is developed to calculate the distribution parameters or CDF values for each month and in each grid cell using historical data that will be used in second algorithm. The second algorithm is built to calculate the drought severity index using forecast data and distribution parameters or CDF values. Outcomes of the analysis are forecasted drought regions and drought index in each province in Indonesia, showing the top and bottom boundaries of the forecast essembled models. Bias correction must be carried out if the hindcast data are available in order to obtain more accurate drought forecasting results. The insight of drought early warning system that is described in this paper hopefully can guide the researchers to develop the drought early warning system in Indonesia.

A simple algorithm for calculating values for folded normal distribution

Folded normal distribution originates from the modulus of normal distribution. In the present article, we have formulated the cumulative distribution function (cdf) of a folded normal distribution in terms of standard normal cdf and the parameters of the mother normal distribution. Although cdf values of folded normal distribution were earlier tabulated in the literature, we have shown that those values are valid for very particular situations. We have also provided a simple approach to obtain values of the parameters of the mother normal distribution from those of the folded normal distribution. These results find ample application in practice, for example, in obtaining the so-called upper and lower α-points of folded normal distribution, which, in turn, is useful in testing of the hypothesis relating to folded normal distribution and in designing process capability control chart of some process capability indices. A thorough study has been made to compare the performance of the newly developed theory to the existing ones. Some simulated as well as real-life examples have been discussed to supplement the theory developed in this article. Codes (generated by R software) for the theory developed in this article are also presented for the ease of application.

Validity of establishing pediatric reference intervals based on hospital patient data: A comparison of the modified Hoffmann approach to CALIPER reference intervals obtained in healthy children

ObjectivesTo compare pediatric reference intervals calculated using hospital-based patient data with those calculated using samples collected from healthy children in the community as part of the CALIPER study. MethodsHospital-based data for 13 analytes (calcium, phosphate, iron, ALP, cholesterol, triglycerides, creatinine, direct bilirubin, total bilirubin, ALT, AST, albumin and magnesium), measured on the Vitros 5600, collected between 2007 and 2011 were obtained. The data for each analyte were partitioned by age and gender as previously defined by the CALIPER study. Outliers in each partition were removed using the Tukey method. The cumulative distribution function (cdf) was then determined for each analyte value following which, the inverse cdf values of a standard Gaussian distribution were calculated. The analyte values were plotted against the inverse cdf of the standard Gaussian distribution. Piece-wise regression determined the linear portion of the resulting graph using the statistical software R. Linear regression determined an equation for the linear portion in each partition and reference intervals were calculated by extrapolating to identify the 2.5th and 97.5th centiles in each partition based on the inverse cdf values (which would correspond to the values −1.96 and 1.96 of the Gaussian distribution). Using the 90% confidence intervals for the reference intervals defined by CALIPER and the Reference Change Value (RCV) as the criteria, these calculated reference intervals were compared to those reported previously by CALIPER. Reference samples were also measured on the Vitros 5600 analyzer in an attempt to validate the calculated reference intervals. ResultsIn general, the reference intervals calculated from hospital-based data were generally wider than those calculated by CALIPER. None of the reference intervals calculated using the Hoffmann approach fell completely within the 90% confidence intervals calculated by CALIPER. ConclusionsThese results suggest that calculating pediatric reference intervals from hospital-based data may be useful, as a guide, in some cases but will likely not replace the need to establish reference intervals in healthy pediatric populations.

Trimmed Opinion Pools and the Crowd's Calibration Problem

We introduce an alternative to the popular linear opinion pool for combining individual probability forecasts. One of the well-known problems with the linear opinion pool is that it can be poorly calibrated. It tends toward underconfidence as the crowd's diversity increases, i.e., as the variance in the individuals' means increases. To address this calibration problem, we propose the exterior-trimmed opinion pool. To form this pool, forecasts with low and high means, or cumulative distribution function (cdf) values, are trimmed away from a linear opinion pool. Exterior trimming decreases the pool's variance and improves its calibration. A linear opinion pool, however, will remain overconfident when individuals are overconfident and not very diverse. For these situations, we suggest trimming away forecasts with moderate means or cdf values. This interior trimming increases variance and reduces overconfidence. Using probability forecast data from U.S. and European Surveys of Professional Forecasters, we present empirical evidence that trimmed opinion pools can outperform the linear opinion pool.This paper was accepted by Rakesh Sarin, decision analysis.

Trimmed Opinion Pools and the Crowd's Calibration Problem

We introduce an alternative to the popular linear opinion pool for combining individual probability forecasts. One of the well-known problems with the linear opinion pool is that it can be poorly calibrated. It tends toward underconfidence as the crowd’s diversity increases, i.e., as the variance in the individuals’ means increases. To address this calibration problem, we propose the exterior-trimmed opinion pool. To form this pool, forecasts with low and high means, or cumulative distribution function (cdf) values, are trimmed away from a linear opinion pool. Exterior-trimming decreases the pool’s variance and improves its calibration. A linear opinion pool, however, will remain overconfident when individuals are overconfident and not very diverse. For these situations, we suggest trimming away forecasts with moderate means, or cdf values. This interior-trimming increases variance and reduces overconfidence. Using probability forecast data from US and European Surveys of Professional Forecasters, we present empirical evidence that trimmed opinion pools can outperform the linear opinion pool.

Development of a localized probabilistic sensitivity method to determine random variable regional importance

There are many methods to identify the important variable out of a set of random variables, i.e., “inter-variable” importance; however, to date there are no comparable methods to identify the “region” of importance within a random variable, i.e., “intra-variable” importance. Knowledge of the critical region of an input random variable (tail, near-tail, and central region) can provide valuable information towards characterizing, understanding, and improving a model through additional modeling or testing. As a result, an intra-variable probabilistic sensitivity method was developed and demonstrated for independent random variables that computes the partial derivative of a probabilistic response with respect to a localized perturbation in the CDF values of each random variable. These sensitivities are then normalized in absolute value with respect to the largest sensitivity within a distribution to indicate the region of importance. The methodology is implemented using the Score Function kernel-based method such that existing samples can be used to compute sensitivities for negligible cost. Numerical examples demonstrate the accuracy of the method through comparisons with finite difference and numerical integration quadrature estimates.

Exact distributional computations for Roy’s statistic and the largest eigenvalue of a Wishart distribution

Computational expressions for the exact CDF of Roy's test statistic in MANOVA and the largest eigenvalue of a Wishart matrix are derived based upon their Pfaffian representations given in Gupta and Richards (SIAM J. Math. Anal. 16:852---858, 1985). These expressions allow computations to proceed until a prespecified degree of accuracy is achieved. For both distributions, convergence acceleration methods are used to compute CDF values which achieve reasonably fast run times for dimensions up to 50 and error degrees of freedom as large as 100. Software that implements these computations is described and has been made available on the Web.

On the computation of the noncentral F and noncentral beta distribution

Unfortunately many of the numerous algorithms for computing the comulative distribution function (cdf) and noncentrality parameter of the noncentral F and beta distributions can produce completely incorrect results as demonstrated in the paper by examples. Existing algorithms are scrutinized and those parts that involve numerical difficulties are identified. As a result, a pseudo code is presented in which all the known numerical problems are resolved. This pseudo code can be easily implemented in programming language C or FORTRAN without understanding the complicated mathematical background. Symbolic evaluation of a finite and closed formula is proposed to compute exact cdf values. This approach makes it possible to check quickly and reliably the values returned by professional statistical packages over an extraordinarily wide parameter range without any programming knowledge. This research was motivated by the fact that a very useful table for calculating the size of detectable effects for ANOVA tables contains suspect values in the region of large noncentrality parameter values compared to the values obtained by Patnaik's 2-moment central-F approximation. The cause is identified and the corrected form of the table for ANOVA purposes is given. The accuracy of the approximations to the noncentral-F distribution is also discussed.

An estimation of an uncertainty caused by a direct propagation of the Level 1 ET sequence cut sets into the Level 2 risk

While the current risk-informed framework for a Level 2 PSA requires a complete transfer of all the Level 1 ET sequence information into the relevant PDSs (or Level 2 risk metrics), most practices on the PDS binning process often show an inconsistency between the Level 1 CDF and the Level 2 risk although both values must be theoretically the same in that case. Clarification of the foregoing issue is crucial since the PDS-related uncertainty analysis is a starting point of the Level 2 risk analysis and consequently whose portion is directly transferred to the Level 2 risk metrics. For this, a plant-specific impact of an analyst’s different choice (or criteria) of the PDS definition has been analyzed with the way the Level 1 ET sequence cut sets are directly linked with the relevant PDSs during the Level 1/2 binning process. The present result shows that the foregoing difference is mainly caused by a combined impact of two competing uncertainty sources: (1) one source is a decrease of the PDS frequency due to a truncation limit and (2) the other source is its increase due to extra independent cut sets generated in the direct linking process of the Level 1 ET sequence cut sets with the relevant PDSs. From the numerical viewpoint, the plant-specific contribution of an uncertainty caused by the current Level 1/2 binning process to the Level 2 risk ranges from −1.2% to 2.5% of the Level 1 CDF value, consequently leading to the corresponding contribution to the Level 2 risk uncertainty.

Efficient image enhancement technique by decimation method

In this paper, an efficient image enhancement method is proposed. The proposed algorithm consists of three blocks: the decimation filter, the decision block, and the contrast enhancement. It employs a probability density value in order to control a sudden change in image-brightness. In addition, the proposed algorithm uses a spatial decimation method. It reduces the amount of computation required for image enhancement by using the images generated by spatial decimation method. For a real-time processing, CDF values are calculated by using a first order linear interpolation method. From the simulation results, the proposed method shows better performance and significant reduction in the computational cost compared to a conventional method. The proposed method can be used in the display devices such as LCD TV and PDP TV that require the image enhancements.

Gender-related difference, geographical variation and time trend in dietary cadmium intake in Japan

Objectives: The present analysis was initiated to examine possible gender-dependency, geographic variation, and time-dependent changes in dietary intake of cadmium (Cd-F) among general populations in Cd-non-polluted areas in Japan. The role of rice as Cd-F source was also within the scope. Methods: Two databases on Cd and nutritional analyses were re-visited. Both databases were established through collection of 24-h food duplicate portion samples from residents in areas with no known Cd pollution, and contained information on Cd and energy contents in the duplicate portion, together with daily rice consumption, the gender, the age and the location of the residence of each sample donor. The first and the second databases were established through surveys in the years around 1980 on 564 cases and around 1995 on 702 cases, respectively. The two databases were combined for evaluation by multiple regression (MRA) and other analyses. Results: The analyses showed that men tended to take more Cd than women, more clearly so in the 1980 survey than in the 1995 survey. When Cd-F in the 1995 survey was compared with that in the 1980 survey, a substantial decrease was observed, e.g. by 30% (from 37.5 to 26.2 μg/day) in case of women. Cd-F values varied subject to the survey sites in a wide range (e.g. from 20 to 86 μg/day among women in the 1980 survey). In MRA with Cd-F as a dependent variable and survey sites and food intake factors (e.g. rice and energy intakes) as independent variables, the survey sites could explain more than 53% and 35% of total variation in Cd-F in the 1980 and 1995 surveys, respectively. Rice consumption was also influential to Cd-F in both surveys with partial correlation coefficients of 0.36 and 0.21, respectively, the influence being stronger in the 1980 survey than in the 1995 survey. A significant correlation was detected between the 1980 and 1995 survey results both in Cd-F and in rice consumption. Conclusion: Geographic and gender-related differences, and time-dependent decrease in dietary Cd intake in Japan were detected through analyses of food duplicate-based databases. The leading role of rice as dietary Cd source was also observed.