3,438 research outputs found
Popular matchings with two-sided preferences and one-sided ties
We are given a bipartite graph where each vertex has a
preference list ranking its neighbors: in particular, every ranks its
neighbors in a strict order of preference, whereas the preference lists of may contain ties. A matching is popular if there is no matching
such that the number of vertices that prefer to exceeds the number of
vertices that prefer to~. We show that the problem of deciding whether
admits a popular matching or not is NP-hard. This is the case even when
every either has a strict preference list or puts all its neighbors
into a single tie. In contrast, we show that the problem becomes polynomially
solvable in the case when each puts all its neighbors into a single
tie. That is, all neighbors of are tied in 's list and desires to be
matched to any of them. Our main result is an algorithm (where ) for the popular matching problem in this model. Note that this model
is quite different from the model where vertices in have no preferences and
do not care whether they are matched or not.Comment: A shortened version of this paper has appeared at ICALP 201
A Novel Inter Connection of DFIG with Grid in Separate Excitation SMES System with Fuzzy Logic Control
The use of doubly fed induction generators (DFIGs) in wind turbines has become quite common over the last few years. DFIG wind turbine is an integrated part of distributed generation system. This paper presents a Fuzzy based controller SMES unit in DFIG for improving the ac output on grid side. The excitation system is composed of the rotor-side converter, the grid-side converter, the dc chopper and the superconducting magnet. The superconducting magnet is connected with the dc side of the two converters, which can handle the active power transfer with the rotor of DFIG and the power grid independently, even thou Sutton small fluctuations are occur in active power on AC side. For smoothening the AC output power waveform a Fuzzy based controller is introduced in SMES controller unit, which implemented using simulation developed in MATLAB/ SIMULINK 7.2 version. The model of the FUZZY controlled SMES based excitation system for DFIG is established, and the simulation tests are performed to evaluate the system performance
Meconium stained liquor and fetal outcome: a hospital based follow up study
Background: Meconium staining of the amniotic fluid is a common problem occurring in 10-22% of all deliveries. Meconium aspiration syndrome complicates approximately 1.5% of these deliveries with a reported mortality rate as high as 40%. Objectives of the study were to determine whether meconium stained liquor during labour is associated with fetal distress and to check if there is any correlation in between the degree of meconium staining liquor and fetal outcome.Methods: A clinical study of 200 cases of meconium stained amniotic fluid in cephalic presentation was undertaken among patients who were admitted in labour room were examined in detail and investigations were done. Fetal heart rate and its pattern were noted every fifteen min. Total APGAR score at one minute and five minute was noted down. Odds ratio with 95% confidence interval was calculated. Proportions were analyzed using chi square value.Results: Majority of the study subjects belonged to the age group of 21-30 years. Majority i.e. 54.5% were multigravida. Majority had toxemia in 24% of the cases. Fetal distress and the incidence of forceps delivery or LSCS was significantly more in those with thick meconium compared to those with thin meconium (p<0.05). But fetal asphyxia was not associated with type of stained meconium. It is seen that as the duration of the meconium staining increased, the proportion of babies with low APGAR score, perinatal mortality and morbidity increased.Conclusions: Thick meconium stained amniotic fluid was associated with increased rate of interventions, neonatal morbidity and mortality compared to thin meconium stained meconium fluid
Determinants of anemia among pregnant women: A hospital based cross sectional study
Background: The objective was to study the determinants of anemia among pregnant women. There is a negative effect on the health of the mother and as well as that of the child due to anemia in women with pregnancy. Death rate is more in women who are pregnant and having anemia. The objective of this study was to study the determinants of anemia among pregnant women.Methods: A hospital based cross sectional study was carried out among 40 pregnant women over a period of six months. Demographic data like age, residence, occupation etc was recorded. Obstetric data like gravida, parity, previous LSCS was also recorded. The data was presented as means and studentâs t test was applied.Results: The mean age was 23.43±3.4 years. Majority were young between the ages of 19-22 years. Majority belonged to urban residents i.e. 57.5%. 20% of the subjects were found to be illiterate. Majority of the mothers were housewives i.e. 82.5%. Majority were multi-gravida i.e. 60%. Majority had no history of abortions in the past i.e. 75%. Out of total 19 repeat pregnancies, majority i.e. 84.2% had lower segment cesarean section. Majority reported that they had normal menstrual history. The mean hemoglobin level was found out to be 7.94 gm/dl. It was found that the mean hemoglobin level did not differ significantly across age, residence, education, occupation, gravidity, history of abortions, type of delivery but differed significantly by abnormal menstrual cycle.Conclusions: Mean hemoglobin level was more in women with normal menstrual history compared to those women with abnormal menstrual history and this difference was found out to be statistically significant. Hence abnormal menses should be promptly treated, hemoglobin assessed
Evaluation and comparison of automated analysers on hepatic enzymes
Background:Clinical Biochemistry tests comprise over one third of all hospital laboratory investigation. The laboratory accreditation requirement has become an important aspect in selecting the analysers for analysing and evaluating the samples. Recently accrediting bodies are focusing on the importance of total quality management and assessment of trueness of laboratory measurements. The present study aimed to evaluate the hepatic enzymes using a single analytical methodology in 2 different automated analysers (semi autoanalyser and fully automated analyser) to understand the reliability of instrumentation on analytical methodology that would fit the laboratory performance standard.Methods:A total number of 50 serum samples from adult patients requested for liver function tests at Shri Sathya Sai medical college and research institute were analysed. The samples were evaluated for hepatic enzymes on (Cobasmira) Autoanalyser and (Biosystems) Semi Autoanalyser using the same analytical methodology and the values were compared between the 2 automated analysers. Data analysis was done by appropriate statistical methods.Results:No large differences were obtained in the values between the 2 automated analysers. Mean ± SD of each of the hepatic enzyme analysed by automated analysers were very close to each other indicating a minimum bias. Pearsonâs correlation and scattered diagram showed significant positive correlation at 95% confidence interval between 2 automated analysers.  Conclusion:The findings of this study confirm that both the automated analysers were reliable for evaluation of hepatic enzymes.
Rank Maximal Matchings -- Structure and Algorithms
Let G = (A U P, E) be a bipartite graph where A denotes a set of agents, P
denotes a set of posts and ranks on the edges denote preferences of the agents
over posts. A matching M in G is rank-maximal if it matches the maximum number
of applicants to their top-rank post, subject to this, the maximum number of
applicants to their second rank post and so on.
In this paper, we develop a switching graph characterization of rank-maximal
matchings, which is a useful tool that encodes all rank-maximal matchings in an
instance. The characterization leads to simple and efficient algorithms for
several interesting problems. In particular, we give an efficient algorithm to
compute the set of rank-maximal pairs in an instance. We show that the problem
of counting the number of rank-maximal matchings is #P-Complete and also give
an FPRAS for the problem. Finally, we consider the problem of deciding whether
a rank-maximal matching is popular among all the rank-maximal matchings in a
given instance, and give an efficient algorithm for the problem
Covid â 19: Impact On The Indian Economy
The onset of COVID-19, the global economy is set to undergo a sharp double-dip recession. As many international agencies have already forecasted, the global growth could be -3 per cent in 2020, which is a decline of about 6 percentage points from the baseline projection of positive 3 per cent growth with no pandemic. Such swings in growth forecasts are unprecedented, and this is due to both health scare with lots of deaths and infections and also due to the lockdown of a major part of the global economy. Added to this, the pandemic appears to be more severe in the industrialized economy. While the forecasts for 2021 suggest a sharp rebound, the trends suggest that the world may need to endure this for a longer period than expected. Unlike the global economy, Indian economy was already in a slowdown phase before the pandemic affected and there were expectations that the economy is on a recovery path. But, with the COVID-19 such hopes are not only dented rather down turn turning out to be much deeper. There are various forecasts that suggest a sharper slowdown. Some forecasts even suggest a negative growth, which was not heard in the past five decades. With the lockdown and with increasing infections, the uncertainty in the economy has increased manifolds. There are also discussions about the shapeoftherecoveryâVorUorW. But, in our view, the most probabilistic recovery could see an elongated U shape
A Study on Customers Service among Tamilnadu Mercantile Bank in Erode Branch
The Financial institution specially banking industry is one of the areas where many public, private & foreign banks are operating their businesses to different customers in every nuke of the country. This study is undertaking the customer service towards Tamilnadu Mercantile bank at Erode. Banking is considered to be nerve center of trade, commerce and business in a country .It plays a vital role in distributing the money for the development of trade, industry and commerce. Therefore we may say that banking is life blood of the modern commerce. A banker is not only dealers money but also leaders in economic development of a country. The fundamental aspects of banking i.e. trust and the confidence of the people on institution remain same. The majority of banks are still successful in keeping with the confidence of the customer even though the main problems of the customer are not well aware of the service provided by their bank. Financial institution specially banking industry is one of areas where many public, private & foreign banks are operating their businesses to different customers in every nuke of the country. In the process to attract customers these banks are providing highest level of service quality to satisfy the varying needs of todayâs customers, but service quality is not alone sufficient trust among the customers is another important factor which is a predictor of consumer service
Spatial patterns of tree and shrub species diversity in Savanadurga State Forest, Karnataka
A study conducted in Savanadurga State Forest in Karnataka indicates that the spatial variation of trees
was high and similarity among the species in the adjacent
plots was low, suggesting that the spatial heterogeneity
is influencing the pattern of diversity of tree species. The degraded forest, which is considered as shrub and tree savanna of the AnogeissusâChloroxylonâAcacia series is highly diverse, recording over 59 tree and 119 shrub species. Tree species similarity index among quadrats in the forest is less than 0.02, indicating high diversity in tree species within a limited area of the sample. Conversely, the shrub species are far more similar than the tree species when the two plots are compared. The number of stems > 1 cm DBH observed in the sampled plot (7844/ha) is high, further reinforcing that the area is rich in species and stems. Correlation between species diversity of mean and standard deviations of adjacent plots of the focal plot was high, indicating that the species-rich patches in the forests are likely to associate with other speciesrich patches. The study is based on 30 quadrats of 25 m ÂŽ 25 m laid at 1 km interval over the state forest
- âŠ