Multiple Calendars Research Articles

The Accumulating Deficits Model for Postoperative Mortality and Readmissions: Comparison of Four Methods Over Multiple Calendar Year Cohorts.

To assess 4 measures of the accumulating deficits model of frailty for postoperative mortality and readmissions including their stability over time. Frailty has been assessed by multiple methods. It is unclear whether variation in how frailty is measured is important and would be stable over time. Rockwood's 57-item frailty index was mapped onto 14,568 ICD9 diagnosis codes from Healthcare Cost and Utilization Project State Inpatient Database for the state of Florida (HCUP-SID-FL) for calendar years 2011 to 2015, inclusive, with 962 ICD9 codes matching onto 42 items. This became the modified frailty index (mFI) used. Three measures of the mFI were differentiated: the number of admission diagnoses, number of chronic conditions upon admission, and number of increased deficits accumulated during the admission. The Charlson Co-Morbidity Index was a fourth measure of frailty. The mFI of patients who survived or died and were readmitted or not were compared. Across all years, 4,796,006 patient observations were compared to the number of diagnoses matched on the 42 items of the mFI. The median mFI scores for each method was statistically significantly higher for patients who died compared those that survived and for patients readmitted compared to patients not readmitted for all years. There was little-to-no variation in the year to year median mFI scores. The 4 methods of calculating frailty performed similarly and were stable. The actual method of determining the accumulated deficits may not be as important as enumerating their number.

Stability of the Modified Frailty Index for Postoperative Mortality and Readmissions over Multiple Calendar Year Cohorts

Stability of the Modified Frailty Index for Postoperative Mortality and Readmissions over Multiple Calendar Year Cohorts

VARX and GSTARX Models for Forecasting Currency Inflow and Outflow with Multiple Calendar Variations Effect

VARX and GSTARX models are an extension of Vector Autoregressive (VAR) and Generalized Space-Time Autoregressive (GSTAR) models. These models include exogenous variable to increase the forecast accuracy. The objective of this research is to develop and compare the forecast accuracy of VARX and GSTARX models in predicting currency inflow and outflow in Bali, West Nusa Tenggara, and East Nusa Tenggara that contain multiple calendar variations effects. The exogenous variables that are used in this research are holidays in those three locations, i.e. EidFitr, Galungan, and Nyepi. The proposed VARX and GSTARX models are evaluated through simulation studies on the data that contain trend, seasonality, and multiple calendar variations representing the occurrence of EidFitr, Galungan, and Nyepi. The criteria for selecting the best forecasting model is Root Mean Square Error (RMSE). The results of a simulation study show that VARX and GSTARX models provide similar forecast accuracy. Furthermore, the results of currency inflow and outflow data in Bali,West Nusa Tenggara, and East Nusa Tenggara show that the best model for forecasting inflow and outflow in these three locations are VARX and GSTARX (with uniform weight) model, respectively. Both models show that currency inflow and outflow in Bali, West Nusa Tenggara, and East Nusa Tenggara have a relationship in space and time, and contain trends, seasonality and multiple calendar variations.

Flexible resource management and its effect on project cost and duration

In practice, most projects result in cost overruns and schedule slippage due to poor resource management. This paper presents an approach that aims at reducing project duration and costs by empowering project managers to assess different scenarios. The proposed approach addresses combinatorial modes for tasks, multi-skilled resources, and multiple calendars for resources. A case study reported in the literature is presented to demonstrate the capabilities of this method. As for practical implications, this approach enhances the decision-making process which results in improved solutions in terms of total project duration and cost. From an academic viewpoint, this paper adds empirical evidence to enrich the existing literature, as it highlights relevant issues to model properly the complexity of real-life projects.

Zebrafish Database: Customizable, Free, and Open-Source Solution for Facility Management.

Zebrafish Database is a web-based customizable database solution, which can be easily adapted to serve both single laboratories and facilities housing thousands of zebrafish lines. The database allows the users to keep track of details regarding the various genomic features, zebrafish lines, zebrafish batches, and their respective locations. Advanced search and reporting options are available. Unique features are the ability to upload files and images that are associated with the respective records and an integrated calendar component that supports multiple calendars and categories. Built on the basis of the Joomla content management system, the Zebrafish Database is easily extendable without the need for advanced programming skills.

Calendar Based Mean Reversion Risk and Digital Signal Processing

The nature of risk and long-term returns is not fully understood. There is a need for a measure of long-term risk at multiple horizons. Digital signal processing and an additive noise model are used to test the white noise hypothesis for total and idiosyncratic risk of individual firms at two-month to four-year periods. All firms have significant annual effect risk. January-like effects influence small firms. Large firm total risk and mid-cap firm idiosyncratic risk are influenced by Joseph (8-year) and summer effects. Large firm idiosyncratic risk reflects presidential effects. The results suggest that single period risk is composed of multiple long-term calendar and non-calendar variances.

Modeling gross primary productivity for winter wheat–maize double cropping system using MODIS time series and CO 2 eddy flux tower data

Accurate and spatially explicit monitoring of gross primary productivity of agricultural ecosystems at a large scale is of great significance to assessment of crop conditions and agricultural production, and is necessary for understanding the carbon balance of the terrestrial biosphere. Identifying crop intensity (including multiple cropping and crop calendar) dynamics and assigning appropriate light use efficiency to C3 and C4 crops could substantially improve our ability to model and evaluate the seasonal dynamics of carbon flux in intensified agricultural ecosystems. In this paper, we have analyzed temporal dynamics of vegetation indices and phenological characteristics in the winter-wheat and maize double cropping system using multi-year satellite images from the moderate resolution imaging spectral radiometer (MODIS) and in situ observation of key crop phenological transition dates. The multiple cropping and crop calendar information were incorporated into simulations of the satellite-based vegetation photosynthesis model (VPM). Canopy-level maximum light use efficiency, a key parameter in the satellite-based VPM model, was estimated for both winter wheat (C3) and maize (C4) based on the observed CO 2 flux data from an eddy flux tower site in a winter wheat-maize double cropping agro-ecosystem in the Huang-Huai-Hai plain, China. The seasonal dynamics of GPP predicted by the VPM model agreed well with estimated GPP from eddy flux tower data. These results demonstrate the potential of the satellite-driven VPM model for scaling-up GPP estimation of intensified agricultural ecosystems, which is relevant to food production and security.

Fill My Datebook: A software tool to generate and handle lists of events

Electronic calendars, and especially Internet-based calendars, are becoming more and more popular. Their advantages over paper calendars include being able to easily share events with others, gain remote access, organize multiple calendars, and receive visible and audible reminders. Scientific experiments often include a huge number of events that have to be organized. Experimental schedules that follow a fixed scheme can be described as lists of events. The software application presented here allows for the easy generation, management, and storage of lists of events using the Internet-based application Google Calendar.

Critical Path Scheduling under Resource Calendar Constraints

Resource calendars specify nonworking days of driving resources involved in construction projects. As part of the resource availability constraints in critical path method (CPM) scheduling, resource calendars may postpone activity start time, extend activity duration, and hence prolong the total project duration. Ultimately, resource calendars bring about changes to the critical path identification. Research has yet to address how to incorporate the effects of multiple resource calendars on the total float determination. In this research, the popular P3 software is used as a tool for investigating the current practice of CPM scheduling under resource limit and calendar constraints. We assess P3’s advanced resource scheduling functions (including resource leveling and resource calendars) and identify P3’s potential errors in total float determination. Further, we propose a new method based on the forward pass analysis alone for accurately evaluating activity total float subject to resource calendar constra...

Integrating multiple calendars using τ ZAMAN

AbstractProgrammers are increasingly interested in developing applications that can be used internationally. Part of the internationalization effort is the ability to engineer applications to use dates and times that conform to local calendars yet can inter‐operate with dates and times in other calendars, for instance between the Gregorian and Islamic calendars. $\tau$ ZAMAN is a system that provides a natural language‐ and calendar‐independent framework for integrating multiple calendars. $\tau$ ZAMAN performs ‘runtime‐binding’ of calendars and language support. A running $\tau$ ZAMAN system dynamically loads calendars and language support tables from XML‐formatted files. Loading a calendar integrates it with other, already loaded calendars, enabling users of $\tau$ ZAMAN to add, compare, and convert times between multiple calendars. $\tau$ ZAMAN also provides a flexible, calendar‐independent framework for parsing temporal literals. Literals can be input and output in XML or plain text, using user‐defined formats, and in different languages and character sets. Finally, $\tau$ ZAMAN is a client/server system, enabling shared access to calendar servers spread throughout the Web. This paper describes the architecture of $\tau$ ZAMAN and experimentally quantifies the cost of using a calendar server to translate and manipulate dates. Copyright © 2006 John Wiley & Sons, Ltd.

Discussion of “Critical Path Method with Multiple Calendars” by Kyunghwan Kim and Jesús M. de la Garza

Discussion of “Critical Path Method with Multiple Calendars” by Kyunghwan Kim and Jesús M. de la Garza

Discussion of “Critical Path Method with Multiple Calendars” by Kyunghwan Kim and Jesús M. de la Garza

Discussion of “Critical Path Method with Multiple Calendars” by Kyunghwan Kim and Jesús M. de la Garza

Closure to “Critical Path Method with Multiple Calendars” by Kyunghwan Kim and Jesús M. de la Garza

Closure to “Critical Path Method with Multiple Calendars” by Kyunghwan Kim and Jesús M. de la Garza

Critical Path Method with Multiple Calendars

This paper presents the critical path method forward and backward passes with multiple calendars. Multiple calendars are required in many construction projects to effectively represent various project conditions such as work properties, resource availabilities, weather conditions, etc. For this reason, major project management software packages such as P3 and MS-Project provide functions to handle multiple calendars. However, the background theory of handling multiple calendars has not been disclosed, so users of those software packages simply assume without clear knowledge that the time data generated by them are correct. This paper provides how multiple calendars should be handled in scheduling. Applying the theory presented herein, it has been noticed that the P3 operations with two calendars may generate a wrong answer for a start-to-finish with zero lag and inconsistent results in all negative lags when nonworking days are involved. The theory covers all four relationships in the precedence diagrammi...

Ancient Egyptian Calendars: How Many Were There?

In 1950, Richard A. Parker hypothesized that pharaonic Egypt had three separate calendars: original lunar; civil; later lunar, of which the most ancient was the original lunar. l To be fair, it should be noted that Ludwig Borchardt first discussed the idea of a second lunar calendar in great detail, and earlier scholars, such as Brugsch (in volume I of his Thesaurus inscriptionum Aegyptiacarum) had also attempted also attempted to explain various anomalies by hypothesizing multiple lunar calendars. The evidence for a Predynastic lunar calendar is explicit in double-dated inscriptions that occur throughout ancient Egyptian history.2 In particular, correlations of a lunar month-and-day date with a civil month-and-day date confirmed Parker's theory that a functioning lunar calendar co-existed with the civil calendar.