Data,data Everywhere: Dealing Data From Sensors Network

Technical Seminar Presentation

Data EveryWhere: Dealing Data From Sensors N/W

Data,Data Everywhere: Dealing Data From Sensors Network Under the guidance of : Mr.Indraneel Mukhopadhyay Technical Seminar Adviser

Rashmi Rekha Das

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Technical Seminar Presentation

Data EveryWhere: Dealing Data From Sensors N/W

Introduction What is sensor network? It is continuously collecting and communicating the data string to the database.

What is its real life application? Monitoring physical phenomena such as climate, concentration of contaminants, building structure and response to earthquakes, etc.

How does it operate? It will operate as black-boxes that record diagnostic data, performance data, history of the object, etc., e.g., in vehicles, cell phones and computers.

Rashmi Rekha Das

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Technical Seminar Presentation

Data EveryWhere: Dealing Data From Sensors N/W

Introduction What is the work of sensor network? Data gathering techniques using network primitives, data cleaning techniques such as cleaning and querying of noisy data, discovering outliers, and handling incomplete data due to missing values and handling of erroneous sensors.

Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

Background Limitations Limited battery life, storage and processing capabilities which enforce special data handling algorithms and architectures for sensor data streams, that explicitly incorporate these resource constraints. Packet loss and topology changes.

Capabilities Sensors are capable of constructing and maintaining a locally consistent view of its neighborhood .

Rashmi Rekha Das

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Technical Seminar Presentation

Data EveryWhere: Dealing Data From Sensors N/W

Background Sensor streaming Vs Traditional streaming Sensor Streaming Traditional Streaming Samples of population

Entire population

Imprecise and noisy

Exact and error-free

Moderate size

Huge data

Expensive

No cost

Continuous domain

Frequent items,distinct

Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

In-network aggregation Two approaches Tiny Aggregation (TAG) service for adhoc sensor network. Aggregation for monitoring wireless sensor networks .

Query Evaluation Distribution phase The query is distributed to every node in the network. A tree rooted at the base-parents.

Collection phase Parents collect data from children at specific time intervals. Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

In-network aggregation Routing Ability to deliver query requests to every node. Ability to provide one or more routes from every node to the root. In particular, it uses a tree-based routing where one node is the root.

Performance TAG dramatically decreases communication and yields an order of magnitude reduction in communication cost compared to a centralized approach. Heavy packet loss and link asymmetry can be quite common in sensor networks.

Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

In-network storage What is the storage approach in sensor networks? There are generally three approaches for storing data in sensor networks: external, local, and data centric storage approaches . External storage, sensor data is continuously sent to a “powerful” collecting point. Local storage, data are stored locally at its original node. Data centric storage (DCS), data are stored by name, and therefore, there is a cost of communicating the data from its original node to the node where it will be stored. However, cost of querying in this case is reduced since queries are directed to the node that stores the data and not to every node in the network. Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

Architecture for sensor streams These systems enable three types of queries on sensor streams: historical queries, snapshot queries, and longrunning queries. An architecture is proposed for managing multiple queries over streams of sensors and traditional data sources.

Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

Fjording sensor streams The architecture consists of two major components: Fjord and sensor. Users issue queries using sensor catalogs to the query processor. The sensors relay their readings to the proxy either as raw or Processed signals, e.g., aggregate. The proxy packs these samples as tuples and forwards them to the query processor. The processor processes the query using the provided data and, finally, output the answer to the end users.

Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

Erroneous sensor data Online cleaning The uncertainty model can be computed either at the sensor level or at the database server when sensor data arrives . As sensor data flows, we incorporate the likelihood of obtaining the observed values with prior knowledge of the distribution of the true values and, consequently, we obtain posterior uncertainty models of the unknown true values.

Rashmi Rekha Das

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Data EveryWhere: Dealing Data From Sensors N/W Technical Seminar Presentation

Conclusion In particular, we surveyed current research in storage and gathering of sensor data, architectures for querying sensor streams, and data cleaning. Also, imprecision due to noise, missing values, massiveness of data, etc., and deriving new optimization metrics in query evaluation. A decision making infrastructure will be built on top of these sensors. This infrastructure will enable extraction of any needed information, directly from sensors, on demand, and in real-time. Rashmi Rekha Das

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Technical Seminar Presentation

Data EveryWhere: Dealing Data From Sensors N/W

THANK YOU

Rashmi Rekha Das

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