Operations research techniques have been used widely in simulating the dynamics of workforce systems. Discrete Event Simulation (DES) and System Dynamics (SD) are among the techniques that have been increasingly used in modelling military workforces. In the last five years, DES has seen more interest in modelling both career management and the training pipeline. Two significant reasons for this are discussed in this paper. This article presents some notes in comparing the two techniques in modelling military workforce. The study found that DES is an appealing method in workforce modelling, especially with a small size population, as it more easily accommodates new personnel attributes and prevents the fractionalisation of personnel through the system.
In our present investigation a new series of nucleoside derivatives (2-13) were synthesized from uridine (1) via only two step reactions by direct acylation method. Firstly, uridine (1) was treated with 4-t-butylbenzoyl chloride in pyridine at -5?C and afforded the 5´-O-(4-t-butylbenzoyl)uridine derivative (2) in an excellent yield. In order to obtain newer products, the 5´-O-uridine derivative was further transformed to a series of 2´,3´-di-O-acyl derivatives (2-13) containing a wide variety of functionalities in a single molecular framework. The yields of the compounds were more than 80%. The synthesized titled compounds were characterized by their physical properties, FTIR (Fourier transform infrared spectroscopy), 1H-NMR (Nuclear magnetic resonance) spectroscopy and elemental analysis.
As the world is getting overpopulated and over polluted the human being is seeking to utilize new sources of energy that are cleaner, cheaper, and more accessible. Wind is one of these clean energy sources that is accessible everywhere on the planet earth. This source of energy cannot be stored for later use; therefore, environmental circumstances and geographical location of wind plants are crucial matters. This study proposes a model to decide on the optimum location for a wind farm among the demand area. To tackle the uncertainty related to the geographical position of the nominated location such as wind speed; altitude; mean temperature; and humidity; a simulation method is applied on the problem. Other factors such as the time that a plant is out of service and demand fluctuations also have been considered in the simulation phase. Moreover, a probability distribution function is calculated for the turbine power. Then Data Envelopment Analysis (DEA) performs the selection between all the nominated locations for wind farm. The proposed model takes into account several important elements of the problems. Elements such as land cost; average power received from the wind blowing; demand point population etc. are considered at the same time to select the optimum location of wind plants. Finally, the model is applied on a real case in order to demonstrate its reliability and applicability.
This survey research paper explores the methods most commonly used in over 190 studies determining life insurance efficiency. The purpose is to provide an overview of life insurance efficiency studies and guidance as to the (dis)advantages of the different techniques used plus their applicability to life insurance. An evaluation of the different approaches is undertaken plus an examination of the numbers and trends of methods and aspects of life insurance efficiency measurement. This paper also discusses the fundamental elements of life insurance efficiency estimation, such as the set-up and form of outputs and inputs. Findings include that the focus of life insurance efficiency studies considering individual nations has changed. Additionally data envelope analysis is the technique used most commonly with stochastic frontier analysis next. Another main result is that output proxies (akin to) premiums and investment income is utilized most. This study allows practitioners to determine the best techniques to employ in life insurance efficiency studies. Moreover an evaluation by regulators of the value and applicability of such studies is facilitated. This article builds upon those previous to enumerate and investigate the approaches most commonly used in over 190 papers determining life insurance efficiency and has described the advantages and disadvantages of these methods. Therefore an assessment of the overall results of efficiency studies is possible. In addition ideas for potential further research are discussed. Consequently this review will be useful to both practitioners and regulators concerned with this area.