30 research outputs found
An M/G/1 Retrial Queue with Single Working Vacation
We consider an M=G=1 retrial queue with general retrial times and single working vacation. During the working vacation period, customers can be served at a lower rate. Both service times in a vacation period and in a service period are generally distributed random variables. Using supplementary variable method we obtain the probability generating function for the number of customers and the average number of customers in the orbit. Furthermore, we carry out the waiting time distribution and some special cases of interest are discussed. Finally, some numerical results are presented
An M/G/1 Queue with Server Breakdown and Multiple Working Vavation
This paper deals with the steady state behavior of an M=G=1 multiple working vacation queue with server breakdown. The server works with different service times rather than completely stopping service during a vacation. Both service times in a vacation period and in a regular service period are assumed to be generally distributed random variables. The system may breakdown at random and repair time is arbitrary. Further, just after completion of a customer’s service the server may take a multiple working vacation. Supplementary variable technique is employed to find the probability generating function for the number of customers in the system. The mean number of customers in the system is calculated. Some particular cases of interest are discussed. Numerical results are also presented
Application of Geographic Information System in presumed trematode induced uveitis in a hospital based population in Tamilnadu
INTRODUCTION:
In the southern state of TamilNadu, is located the tertiary eye care centre
–Aravind Eye Care System Madurai. In the department of uveitis services a
specific pattern of anterior uveitis prevalent in paediatric population called as
presumed trematode induced uveitis is observed. This disease entity is unique
in that it affects children who are located in specific geographic locales with
water –body related activities.
In this era of nanotechnology GEOGRAPHIC INFORMATION
SYSTEM [GIS] is a new weapon in the armemantorium of scientific
research.In GIS we analyse geographic variables using computer generated maps. GENERAL CHARACTERS OF TREMATODES4
1. Trematodes are leaf–shaped unsegmented flat worms called
flukes.
2. Size of the organisms vary from 1mm to several centimeters in
length.
3. The organ of attachment are two strong muscular cup-shaped
depression called suckers [oral and ventral suckers]
4. Sexes are not separate i.e. each individual worm is a
hermaphrodite [monoecious] except the Schistosomes which
are unisexual .
5. Body cavity is absent .
6. Alimentary canal is present but incomplete with absent anus.
7. Excretory [“flame cells”] and nervous systems are present.
8. Reproductive system is highly developed and complete.
9. They are oviparous since eggs are liberated.
10. Eggs are operculated and can develop only in water . They do
not float in saturated solution of common salt. AIM AND OBJECTIVES: GOAL
The main purpose of application of Geographic Information System
(GIS) in Presumed Trematode Induced Uveitis in AECS – Madurai based
population in Tamil Nadu is :
[1] To find the relation of geographical correlates to this new disease entity
[2] To find if the geographical variables behave differently if applied to the
control group population. The control group is taken as other paediatric
uveitis patients attending uveitis services in the same study period.
[3] To find if any new direction to postulate any hypothesis regarding the gaps
in the lifecycle of this new uveitis entity.
INCLUSION CRITERIA
1. All Paediatric patients diagnosed as Presumed Trematode Induced
Uveitis in Uveitis services, Aravind Eye Care System, Madurai from
June 2004 to December 2005.
2. All Paediatric Uveitis Patients attending Uveitis services, Aravind Eye
Care System, Madurai from June 2004 to December 2005.
3. Patients in both groups who were regular for compliance and follow up.
4. Patients in the state of Tamil Nadu alone are included in the GIS analysis
alone.
4.3. EXCLUSION CRITERIA
1. Patients diagnosed as presumed trematode induced uveitis in age group
greater than 16 years.
2. Coincidental uveitis in paediatric age group that are not referred to
uveitis clinic and treated in other sub specialities, like following trauma,
post intraocular surgery of any cause that responded to conventional
treatment modalities.
3. Patients who are not regular for follow ups
4. Patients from neighbouring states like Kerala, Andhra Pradhesh are
excluded for GIS analysis alone.
CONCLUSION:
It has been traditionally said, “Knowing history maketh a man wiser”.
But time has come wherein we should rephrase it as “Knowing geography with
geographic information system will definitely maketh a man wisest among
them” since GIS has such a tremendous influence on operational research
Finite element analysis of multi-disk rotor-bearing system with transverse crack
The vibration analysis of rotating systems is pronounced as a key function in all the fields of engineering. The behavior of the rotor systems are mainly resulting from the excitations from its rotating elements. There are several numerical methods present to analyze the rotor-bearing systems. Finite element method is a key tool for dynamic analysis of rotor bearing system. The current study describes a multi disk, variable cross section
rotor-bearing system with transverse crack on xisymmetric elements supported on bearings in a fixed frame. The shaft in the rotor-bearing system is assumed to obey Euler- Bernoulli beam theory. The equation of motion of the rotor-bearing system is derived by Lagrangian approach along with finite element method. Finite element model is used for vibration analysis by including rotary inertia and gyroscopic moments with consistent matrix approach. The rotor bearing system consists of two bearings and two rigid disks. One disk is overhung and the other one is placed between the bearings. Internal damping of the shaft and linear stiffness parameter of the bearings are taken into account to obtain the response of the rotor-bearing system. The rotor has variable cross-section throughout the configuration. The disks are modeled as rigid and have mass unbalance forces. The critical speed, unbalance response and natural whirls are analyzed for the typical rotor-bearing system with transverse crack. Analysis includes the effect of crack depths, crack location and spin speed. The results are compared with the results obtained from finite element analysis. The bearing configurations are undamped isotropic and orthotropic. The natural whirl speeds are analyzed for the synchronous whirl for both the uncracked and cracked rotor bearing system using Campbell diagrams. The effect of transverse crack over the starting point of the system instability regions in the rotating speed axis with zero asymmetric angle is examined. Further, Houbolt’s time integration scheme is used to obtain the phase diagrams and frequency response for both the bearing cases to study the stability threshold. Analyses are carried out by using numerical computing software
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Thaan Vuzha Nilam Tharisu: the land without a farmer becomes barren
This report forms a part of the international research project on policy and sustainable agriculture, Policies that Work for Sustainable Agriculture and Regenerated Rural Economies. The report details the findings of one of the constituent studies, undertaken by an Indian NGO, the Society for People's Education and Economic Change (SPEECH). The Importance of this project is that it concentrated on rainfed rather than irrigated agriculture - i.e. the sharp end of rural development in India, and that the focus was very much on the micro-level, looking at policy as seen from the ground. One of the recurring themes throughout the research was the importance of appreciating people as individuals, and in this spirit some of the personal qualities of the research team are shared. The research covers events in sites in the Virudhunagar district of Tamilnadu: Tiruchuli Panchayat Union and the Villur chain of tanks. This is an essentially rural area, where the need for sustainable forms of agriculture and rural livelihoods is clear. The political landscape is fractured and complex (§2.3), and the officials with the responsibility of implementing policy face significant obstacles and disincentives in doing so in response to the needs of local communities
(R1999) Analysis of a Markovian Retrial Queue with Reneging and Working Vacation under N-control Pattern
A Markovian retrial queue with reneging and working vacation under N-control pattern is investigated in this article. To describe the system, we employ a QBD analogy. The model’s stability condition is deduced. The stationary probability distribution is gotten by utilizing the matrix-analytic technique. The conditional stochastic decomposition of the line length in the orbit is calculated. The performance measures and special cases are designed. The model’s firmness is demonstrated numerically