Science News Showing Kuruntokai

Nature is made up of the five elements earth, water, fire, air and space. As long as all creatures that have originated in nature, including man, act in nature in an effort to survive, they also survive and sustain nature. Earth, water, fire, air and space are all around us and within us. Our ancestors worshipped them as pancha bhoota. Science and technology is the process of identifying the energies of all these and harnessing them for our life, prosperity and growth. The purpose of this article is to express opinions on the scientific news that the Kuruntokai shows

Good thoughts that show Kurunthogai

The Sangam literature is of great help in understanding the living conditions of the ancient Tamil people. The Sangam literature is divided into ten songs and eight kinds. The eight volume consists of eight books referred to as eight sums. It is a collection of books compiled by poets who have sung eight volumes of books at different times. Of these, the best epithet 'good' is distinguished by the small sum. This booklet consists of 401 verses consisting of a four-step small and eight-foot-barreled book. It was compiled by 'Puriko'. Among these, the poet who sang the praises of God was Perundevanar who sang Bharatham. Both songs 307 and 391 are nine-footed songs. In this short volume, poets who are distinguished by parables are also included. In this short volume, this article deals with the ideas of good ideas

Hospitality in Kurunthogai

Hospitality is one of the best virtues of tamils. One of the livelihoods of human beings is food. Not all worldly beings live without food. Food is not limited to eating but is a symbol of a society. It would not be an exaggeration to say that hospitality is the reason for this. The system of hospitality is based on the culture of the species of the respective land. Food is an important part of the life environment. The purpose of this article is to explain the characteristics of hospitality in Kurunthogai

Popular matchings with two-sided preferences and one-sided ties

We are given a bipartite graph $G = (A \cup B, E)$ where each vertex has a preference list ranking its neighbors: in particular, every $a \in A$ ranks its neighbors in a strict order of preference, whereas the preference lists of $b \in B$ may contain ties. A matching $M$ is popular if there is no matching $M'$ such that the number of vertices that prefer $M'$ to $M$ exceeds the number of vertices that prefer $M$ to~$M'$. We show that the problem of deciding whether $G$ admits a popular matching or not is NP-hard. This is the case even when every $b \in B$ 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 $b \in B$ puts all its neighbors into a single tie. That is, all neighbors of $b$ are tied in $b$'s list and $b$ desires to be matched to any of them. Our main result is an $O(n^2)$ algorithm (where $n = |A \cup B|$) for the popular matching problem in this model. Note that this model is quite different from the model where vertices in $B$ 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

Water Pollution In India: An Overview

Most ancient civilizations grew along the banks of rivers. Even today, millions of people all over the world live on the banks of rivers and depend on them for their survival. All of us have seen a river large or small either flowing through our town or somewhere else. Rivers are nothing more than surface water flowing down from a higher altitude to a lower altitude due to the pull of gravity. One river might have its source in a glacier another in a spring or a lake. Rivers carry dissolved minerals organic compounds, small grains of sand gravel and other material as they flow downstream. Rivers begin as small streams which grow wider as smaller streams and rivers join them along their course across the land. Eventually they flow into seas or oceans. Unfortunately most of the world’s major rivers are heavily polluted. The pollution of environment is the gift of the Industrial revolution prior to this the agrarian cultures created significant environment deforestation and overgrazing. The Environmental degradation is a byproduct of modern civilization. Water Pollution is a major global problem which requires on going evaluation and revision of water resource policy at all levels. It has been suggested that water pollution is the leading worldwide cause of deaths and diseases and that it accounts for the deaths of more than 14,000 people daily. An estimated 580 people in India die of water pollution related illness every day

Life of Tamil Peoples in Kuruntokai

The Sangam Age is the first period in the history of Tamil literature. Sangam literature is a clear mirror of the life style of the people who lived in the Sangam Age. The Sangam literature also contains references to the customs, beliefs, trade practices, royal character, marriage practices, etc. of the society of the time. Many truths sung in Sangam literature have conquered time and space and are eternal truths. Tamils have lived their lives happily through Kuruntokai. Especially in domestic life, there was an understanding and a maturity of compromise. It is also known that they have lived by the principles of hospitality, material pursuit, and immeasurable love

Maximum Cardinality Popular Matchings in Strict Two-sided Preference Lists

We consider the problem of computing a maximum cardinality {\em popular} matching in a bipartite graph G = (\A\cup\B, E) where each vertex u \in \A\cup\B ranks its neighbors in a strict order of preference. This is the same as an instance of the {\em stable marriage} problem with incomplete lists. A matching $M^*$ is said to be popular if there is no matching $M$ such that more vertices are better off in $M$ than in $M^*$. \smallskip Popular matchings have been extensively studied in the case of one-sided preference lists, i.e., only vertices of \A have preferences over their neighbors while vertices in \B have no preferences; polynomial time algorithms have been shown here to determine if a given instance admits a popular matching or not and if so, to compute one with maximum cardinality. It has very recently been shown that for two-sided preference lists, the problem of determining if a given instance admits a popular matching or not is NP-complete. However this hardness result assumes that preference lists have {\em ties}. When preference lists are {\em strict}, it is easy to show that popular matchings always exist since stable matchings always exist and they are popular. But the complexity of computing a maximum cardinality popular matching was unknown. In this paper we show an $O(mn)$ algorithm for this problem, where n = |\A| + |\B| and $m = |E|$