22 Kasım 2018 Perşembe

Clustering Techniques



Various clustering techniques are used in the literature. These clustering techniques can be grouped under five groups:

Partitioning Clustering
At first all elements are considered as a single cluster, then iteratively grouped the respective elements together in smaller chambers. In other words, it is a clustering technique that divides a data set consisting of n elements into k pieces. Partition clustering is usually done with the help of a objective function. The most popular partitioning clustering techniques are k-Means (Lloyd, 1982), k-Median, k-Medoids, PAM (Rousseeuw and Kaufman, 1990), CLARA (Rousseeuw and Kaufman, 1990) ve CLARANS (Ng and Han, 2002).

Hierarchical Clustering
Data objects are grouped by creating tree-like structures in hierarchical clustering. There are two different approaches to hierarchical clustering: (i) agglomerative, (ii) divisive. In the agglomerative method, a single object is initially selected and the neighbors of these objects are combined with this object according to their distance from this object. In the divisive method, all data is initially a single set, then the set is divided into ideal small partitions iteratively. The most popular hierarchical clustering techniques are BIRCH (Zhang et al., 1996), CURE (Guha et al., 1998), ROCK (Guha et al., 2000), Chameleon (Karypis et al., 1999) ve CACTUS (Ganti et al., 1999).


Density Based Clustering
Data objects are categorized according to core points, boundary points and noise points. Based on the density, the elements around the core points are located in the same clusters. The most popular density based clustering techniques are DBSCAN (Ester et al., 1996), OPTICS (Ankerst et al., 1999), DBCLASD (Xu et al., 1998), DENCLUE (Hinneburg et al., 1998) ve SUBCLU (Kailing et al., 2004).

Grid Based Clustering
The data set is divided into a certain number of cells to form a grid structure and all clustering operations are performed over this grid structure. The most popular grid based clustering techniques are STING (Wang et al., 1997), CLIQUE (Agrawal et al., 1998), Wave Cluster (Sheikholeslami et al., 1998), BANG (Schikuta and Erhart, 1997) ve OptiGrid (Hinneburg and Keim, 1999).

Model Based Clustering
Data elements are combined by a series of statistical and conceptual methods. The harmony between data and some mathematical models is tried to be optimized. There are two different approaches in model-based clustering: statistical approach and artificial neural networks. The most popular grid based clustering techniques are EM (Dempster et al., 1977), COBWEB (Fisher, 1987), CLASSIST (Gennari et al., 1989), SOM (Kohonen, 1997) ve SLINK (Han et al., 2011).

All of the aforementioned clustering algorithms perform batch processing, so they access data on the disk. In this way, they have information about the whole data. They can process the data multiple times and randomly access the data at any point in the algorithm.


16 Kasım 2018 Cuma

Clustering



Clustering in computer science, is an important issue that can be handled both in the field of data mining because it can obtain meaningful patterns from the data and in the field of machine learning because it is a learning method (unsupervised learning). For this reason, a lot of research has been done about clustering. In the field of machine learning, classification is known as supervised learning, clustering is also known as unsupervised learning technique. Because while group labels are known when classifying, group labels are not known in clustering, and finding class tags is the task of the clustering algorithm. Therefore, clustering is more difficult than classification. There are many definitions of cluster and clustering in the literature (Everitt, 1980).

·         A cluster is a collection of elements in which the elements in the same group are similar and in which the elements in different groups are not similar.
·         Clusters are groups in which the distance between two different elements in the same group is smaller than the distance between two elements in two different groups.
·         A cluster is a state of high-density points separated from lower-density points in a d-dimensional attribute space.

 

The purpose of clustering is to divide the finite, unlabeled data set into finite labeled natural groups (Baraldi and Alpaydin, 2002; Vladimir S et al., 2007).

Clustering, as mentioned earlier, is a learning method and nowadays is used in many areas ranges from manufacturing to artificial intelligent and from network security to surveillance system. Maybe you have a computer and work as a server on the internet. There are a lot of node to connect this server. The majority of these nodes also can be innocent so they have normal tcp or udp connection to the server. However there can be some malicious nodes that want to attack and corrupt the server in some ways like DDOS and man-in-the middle attack. So, clustering is a way to learn which node is innocent and which one is malicious node.

13 Şubat 2018 Salı

Microsoft Teaches Artificial Intelligence Goodness


Continuing its innovation efforts that focus on human beings, Microsoft teaches goodness to artificial intelligence systems within the scope of AI For Good initiative. Within the scope of the initiative that Microsoft has realized with an investment of 125 million dollars, it realizes projects to use artificial intelligence within the framework of social responsibility and for the benefit of humanity.


When Bill Gates and Paul Allen founded Microsoft 40 years ago, their goal was to make the computer’s facilities accessible to everyone. The computer that has entered all areas of life has changed many things in business life, industry and social life. Microsoft is now aiming to achieve a similar transformation with artificial intelligence, which provides fast and new solutions by adding experience and new knowledge of specified patterns.

Human and environmental problems are solved by artificial intelligence. Microsoft puts each individual and organization in a position where they can access and benefit from artificial intelligence technology. It is aimed to find solutions to the human and environmental problems that have been left unresolved until today with the artificial intelligence systems developed with a responsibility to empower everyone.

125 million dollar investment the services developed with artificial intelligence started to support people around the world on many issues in order to solve environmental, public and social problems that have been tried to be coped for a long time. Based on these benefits and potential, Microsoft launched the AI for Good initiative with an investment of $ 125 million.

Reference: http://www.hurriyet.com.tr/

7 Ocak 2018 Pazar

Cloud Computing Benefits



We hear a lot about cloud computing, which can be accessed from anywhere with Internet access, where different information is stored. Many traditional desktop applications are disappearing; for example, most software vendors no longer offer desktop software. These companies are moving their products to the cloud and now offering cheap, online subscription-based services that seem ideal for small businesses. Cloud technology gives small businesses the opportunity to access technologies that were previously impossible to access, enabling them to compete with both small and large companies.

“Cloud computing is a model that allows access to a common pool of configurable computing resources, at any time, anywhere, under favorable conditions. Such resources (such as computer networks, servers, databases, applications, services, etc.) can be procured and disposed of in a manner that requires minimal managerial effort and client-provider interaction. This model supports accessibility and includes five key elements, three service delivery models, and four deployment models” (NIST, 2009).


Cloud computing enables you to access business-related data and applications anywhere, anytime at an affordable price. Instead of storing company data on hard drives in the office, you can upload information to the cloud and use it when needed.

Advantages Of Cloud Computing
·         The cloud computing simplifies things.
·         The company continuity is one of the priceless benefits of cloud computing.
·         The cloud computing helps ensure data security.
·         Using the cloud to store data makes collaboration easier and increases employee productivity.
·         The convenience of information on the move.
·         The cloud computing is cost effective.
·         The cloud computing works on cross-platforms.
·         The cloud computing is scalable.
·         The cloud computing usually comes with additional software.
·         The cloud computing application can facilitate integration.
·         You can reduce system hardware by using cloud computing.
·         The cloud computing is flexible.

Reference: https://www.isnet.net.tr/