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Abstract :- Big data is the term for a collection of data sets which are large and complex, it contain structured and
unstructured both type of data. Data comes from everywhere, sensors used to gather climate information, posts to
social media sites, digital pictures and videos etc This data is known as big data. Useful data can be extracted from
this big data with the help of data mining. Data mining is a technique for discovering interesting patterns as well as
descriptive, understandable models from large scale data. In this paper we overviewed types of big data and
challenges in big data for future.
INTRODUCTION
The term 'Big Data' appeared for first time in 1998 in a Silicon Graphics (SGI) slide deck by John Mashey with the title
of "Big Data and the NextWave of InfraStress". Big Data mining was very relevant from the beginning, as the first book
mentioning 'Big Data' is a data mining book that appeared also in 1998 by Weiss and Indrukya . However,the first
academic paper with the words 'Big Data' in the title appeared a bit later in 2000 in a paper by Diebold .The origin of the
term 'Big Data' is due to the fact that we are creating a huge amount of data every day. Usama Fayyad in his invited talk
at the KDD BigMine‟ 12Workshop presented amazing data numbers about internet usage, among them the following:
each day Google has more than 1 billion queries per day, Twitter has more than 250 milion tweets per day, Facebook has
more than 800 million updates per day, and YouTube has more than 4 billion views per day. The data produced
nowadays is estimated in the order of zettabytes, and it is growing around 40% every year.A new large source of data is
going to be generated from mobile devices and big companies as Google,Apple,Facebook,Yahoo are starting to look
carefully to this data to find useful patterns to improve user experience. “Big data” is pervasive, and yet still the notion
engenders confusion. Big data has been used to convey all sorts of concepts, including: huge quantities of data,social
media analytics, next generation data management capabilities, real-time data, and much more. Whatever the label,
organizations are starting to understand and explore how to process and analyze a vast array of information in new ways.
In doing so, a small, but growing group of pioneers is achieving breakthrough business outcomes. In industries
throughout the world, executives recognize the need to learn more about how to exploit big data. But despite what seems
like unrelenting media attention, it can be hard to find in-depth information on what organizations are really doing. So,
we sought to better understand how organizations view big data – and to what extent they are currently using it to benefit
their businesses.
II. TYPES OF BIG DATA AND SOURCES
There are two types of big data: structured and unstructured.
Structured data are numbers and words that can be easily categorized and analyzed. These data are generated by things
like network sensors embedded in electronic devices, smartphones, and global positioning system (GPS) devices.
Structured data also include things like sales figures, account balances, and transaction data.
Unstructured data include more complex information, such as customer reviews from commercial websites, photos and
other multimedia, and comments on social networking sites. These data can not easily be separated into categories or
analyzed numerically.
“Unstructured big data is the things that humans are saying,” says big data consulting firm vice president Tony Jewitt of
Plano,Texas. “It uses natural language.”Analysis of unstructured data relies on keywords, which allow users to filter the
data based on searchable terms. The explosive growth of the Internet in recent years means that the variety and amount of
big data continue to grow. Much of that growth comes from unstructured data.
Big Data starts with large-volume, heterogeneous, autonomous sources with distributed and decentralized control, and
seeks to explore complex and evolving relationships among data.These characteristics make it an extreme challenge for
discovering useful knowledge from the Big Data. In a naïve sense, we can imagine that a number of blind men are trying
to size up a giant Camel, which will be the Big Data in this context. The goal of each blind man is to draw a picture (or
conclusion) of the Camel according to the part of information he collects during the process. Because each person‟s view
is limited to his local region, it is not surprising that the blind men will each conclude independently that the camel
“feels” like a rope, a hose, or a wall, depending on the region each of them is limited to. To make the problem even more
complicated, let us assume that the camel is growing rapidly and its pose changes constantly, and each blind man may
have his own (possible unreliable and inaccurate) information sources that tell him about biased knowledge about the
camel (e.g., one blind man may exchange his feeling about the camel with another blind man, where the exchanged
knowledge is inherently biased). Exploring the Big Data in this scenario is equivalent to aggregating heterogeneous
information from different sources (blind men) to help draw a best possible picture to reveal the genuine gesture of the
camel in a real-time fashion. Indeed, this task is not as simple as asking each blind man to describe his feelings about the
camel and then getting an expert to draw one single picture with a combined view, concerning that each individual may
speak a different language (heterogeneous and diverse information sources) and they may even have privacy concerns
about the messages they deliberate in the information exchange process.The term Big Data literally concerns about data
volumes, HACE theorem suggests that the key characteristics of the Big Data are
A. Huge with heterogeneous and diverse data sources:-One of the fundamental characteristics of the Big Data is the huge
volume of data represented by heterogeneous and diverse dimensionalities. This huge volume of data comes from various
sites like Twitter,Myspace,Orkut and LinkedIn etc.
B. Decentralized control:- Autonomous data sources with distributed and decentralized controls are a main characteristic
of Big Data applications. Being autonomous, each data source is able to generate and collect information without
involving (or relying on) any centralized control. This is similar to the World Wide Web (WWW) setting where each
web server provides a certain amount of information and each server is able to fully function without necessarily relying
on other servers
C. Complex data and knowledge associations:-Multistructure,multisource data is complex data, Examples of complex
data types are bills of materials, word processing documents, maps, time-series, images and video.
Such combined characteristics suggest that Big Data require a “big mind” to consolidate data for maximum values.
DATA MINING FOR BIG DATA
Generally, data mining (sometimes called data or knowledge discovery) is the process of analyzing data from different
perspectives and summarizing it into useful information - information that can be used to increase revenue, cuts costs, or
both. Technically, data mining is the process of finding correlations or patterns among dozens of fields in large relational
database.
Data mining as a term used for the specific classes of six activities or tasks as follows:
1. Classification
2. Estimation
3. Prediction
4. Association rules
5. Clustering
6. Description
A. Classification
Classification is a process of generalizing the data according to different instances. Several major kinds of classification
algorithms in data mining are Decision tree, k-nearest neighbor classifier, Naive Bayes, Apriori and AdaBoost.
Classification consists of examining the features of a newly presented object and assigning to it a predefined class. The
classification task is characterized by the well-defined classes, and a training set consisting of reclassified examples.
B. Estimation
Estimation deals with continuously valued outcomes. Given some input data, we use estimation to come up with a
value for some unknown continuous variables such as income, height or credit card balance.
C. Prediction
It‟s a statement about the way things will happen in the future , often but not always based on experience or knowledge.
Prediction may be a statement in which some outcome is expected.
D.Association Rules
An association rule is a rule which implies certain association relationships among a set of objects (such as “occur
together” or “one implies the other”) in a database.
E.Clustering
Clustering can be considered the most important unsupervised learning problem; so, as every other problem of this kind,
it deals with finding a structure in a collection of unlabeled data.
CHALLENGES IN BIG DATA
Meeting the challenges presented by big data will be difficult. The volume of data is already enormous and increasing
every day. The velocity of its generation and growth is increasing, driven in part by the proliferation of internet
connected devices. Furthermore, the variety of data being generated is also expanding, and organization‟s capability to
capture and process this data is limited. Current technology, architecture, management and analysis approaches are
unable to cope with the flood of data, and organizations will need to change the way they think about, plan, govern,
manage, process and report on data to realize the potential of big data.
A. Privacy, security and trust
The Australian Government is committed to protecting the privacy rights of its citizens and has recently strengthened the
Privacy Act (through the passing of the Privacy Amendment (Enhancing Privacy Protection) Bill 2012) to enhance the
protection of and set clearer boundaries for usage of personal information.
Government agencies, when collecting or managing citizens data, are subject to a range of legislative controls, and must
comply with the a number of acts and regulations such as the Freedom of Information Act (1982), the Archives Act
(1983), the Telecommunications Act (1997) ,the Electronic Transactions Act (1999), and the Intelligence Services Act
(2001). These legislative instruments are designed to maintain public confidence in the government as an effective and
secure repository and steward of citizen information. The use of big data by government agencies will not change this;
rather it may add an additional layer of complexity in terms of managing information security risks. Big data sources, the
transport and delivery systems within and across agencies, and the end points for this data will all become targets of
interest for hackers, both local and international and will need to be protected. The public release of large machinereadable
data sets, as part of the open government policy, could potentially provide an opportunity for unfriendly state
and non-state actors to glean sensitive information, or create a mosaic of exploitable information from apparently
innocuous data. This threat will need to be understood and carefully managed. The potential value of big data is a
function of the number of relevant, disparate datasets that can be linked and analysed to reveal new patterns, trends and
insights. Public trust in government agencies is required before citizens will be able to understand that such linking and
analysis can take place while preserving the privacy rights of individuals.
B. Data management and sharing
Accessible information is the lifeblood of a robust democracy and a productive economy.2 Government agencies realise
that for data to have any value it needs to be discoverable, accessible and usable, and the significance of these
requirements only increases as the discussion turns towards big data. Government agencies must achieve these
requirements whilst still adhering to privacy laws. The processes surrounding the way data is collected, handled, utilised
and managed by agencies will need to be aligned with all relevant legislative and regulatory instruments with a focus on
making the data available for analysis in a lawful, controlled and meaningful way. Data also needs to be accurate,
complete and timely if it is to be used to support complex analysis and decision making. For these reasons, management
and governance focus needs to be on making data open and available across government via standardised APIs, formats
and metadata. Improved quality of data will produce tangible benefits in terms of business intelligence, decision making,
sustainable cost-savings and productivity improvements. The current trend towards open data and open government has
seen a focus on making data sets available to the public, however these „open‟ initiatives need to also put focus on
making data open, available and standardised within and between agencies in such a way that allows inter-governmental
agency use and collaboration to the extent made possible by the privacy laws.
C.Technology and analytical systems
The emergence of big data and the potential to undertake complex analysis of very large data sets is, essentially, a
consequence of recent advances in the technology that allow this. If big data analytics is to be adopted by agencies, a
large amount of stress may be placed upon current ICT systems and solutions which presently carry the burden of
processing, analysing and archiving data. Government agencies will need to manage these new requirements efficiently
in order to deliver net benefits through the adoption of new technologies.
VII. FORECAST TO THE FUTURE
There are many future important challenges in Big Data management and analytics, that arise from the nature of data:
large, diverse, and evolving. These are some of the challenges that researchers and practitioners will have to deal during
the next years:
A. Analytics Architecture:- It is not clear yet how an optimal architecture of an analytics systems should be to deal with
historic data and with real-time data at the same time. An interesting proposal is the Lambda architecture of Nathan
Marz.The Lambda Architecture solves the problem of computing arbitrary functions on arbitrary data in real time by
decomposing the problem into three layers: the batch layer, the serving layer, and the speed layer. It combines in the
same system Hadoop for the batch layer, and Storm for the speed layer. The properties of the system are: robust and fault
tolerant, scalable, general, extensible, allows ad hoc queries, minimal maintenance, and debuggable.
B. Statistical significance:- It is important to achieve significant statistical results, and not be fooled by randomness.
AsEfron explains in his book about Large Scale Inference it is easy to go wrong with huge data sets and thousands of
questions to answer at once.
C. Distributed mining:- Many data mining techniques are not trivial to paralyze. To have distributed versions of some
methods, a lot of research is needed with practical and theoretical analysis to provide new methods.
D. Hidden Big Data.:-Large quantities of useful data are getting lost since new data is largely untagged file based and
unstructured data. The 2012 IDC study on Big Data explains that in 2012, 23% (643 exabytes) of the digital universe
would be useful for Big Data if tagged and analyzed. However, currently only 3% of the potentially useful data is tagged,
and even less is analyzed
CONCLUSION
Big data is the term for a collection of complex data sets, Data mining is an analytic process designed to explore
data(usually large amount of data-typically business or market related-also known as “big data”)in search of consistent
patterns and then to validate the findings by applying the detected patterns to new subsets of data. To support Big data
mining, high-performance computing platforms are required, which impose systematic designs to unleash the full power
of the Big Data. We regard Big data as an emerging trend and the need for Big data mining is rising in all science and
engineering domains. With Big data technologies, we will hopefully be able to provide most relevant and most accurate
social sensing feedback to better understand our society at real time.