Papers by ASHISH K U M A R JHA
Agriculture is the bedrock of any society and adequate information with regards to it is very vit... more Agriculture is the bedrock of any society and adequate information with regards to it is very vital at any given time. "Android Based Agricultural Info Generation Application" is an android application designed for supported mobiles that majorly focuses on Agriculture sector. It is a client-server architecture in which android mobile acts as a client, Server processes the client's query and relay the related information to the client. Application is installed in mobile device and information updates are sent to it through the server. This work basically identifies plants leaf diseases on the basis of image captured i.e. send via mobile, the server processes the image based on the diseases detected and gives advices if necessary. Different disease information and its remedial/preventive measures are provided in the local server. Users can browse and download information about these agricultural information at any time.
What is Data? Data is a collection of a distinct small unit of information. It can be used in a v... more What is Data? Data is a collection of a distinct small unit of information. It can be used in a variety of forms like text, numbers, media, bytes, etc. it can be stored in pieces of paper or electronic memory, etc. Word 'Data' is originated from the word 'datum' that means 'single piece of information.' It is plural of the word datum. In computing, Data is information that can be translated into a form for efficient movement and processing. Data is interchangeable. Database The database is a collection of interrelated data which is used to retrieve, insert and delete the data efficiently. It is also used to organize the data in the form of a table, schema, views, and reports, etc. For example: The college Database organizes the data about the admin, staff, students and faculty etc. Using the database, you can easily retrieve, insert, and delete the information. Database Management System • Database management system is a software which is used to manage the database. For example: MySQL, Oracle, etc are a very popular commercial database which is used in different applications. ER. ASHISH KR. JHA DATABASE MANAGEMENT SYSTEM ~ 3 ~ ER. ASHISH KR. JHA DATABASE MANAGEMENT SYSTEM ~ 4 ~ • Like file system, this model also had some limitations like complex implementation, lack structural independence, can't easily handle a many-many relationship, etc. 3. Network data model Charles Bachman developed the first DBMS at Honeywell called Integrated Data Store (IDS). It was developed in the early 1960s, but it was standardized in 1971 by the CODASYL group (Conference on Data Systems Languages). In this model, files are related as owners and members, like to the common network model. Network data model identified the following components: o Network schema (Database organization) o Sub-schema (views of database per user) o Data management language (procedural) This model also had some limitations like system complexity and difficult to design and maintain. 4. Relational Database • 1970-Present: It is the era of Relational Database and Database Management. In 1970, the relational model was proposed by E.F. Codd. • Relational database model has two main terminologies called instance and schema. • The instance is a table with rows or columns • Schema specifies the structure like name of the relation, type of each column and name. • This model uses some mathematical concept like set theory and predicate logic. • The first internet database application had been created in 1995. ER. ASHISH KR. JHA DATABASE MANAGEMENT SYSTEM ~ 5 ~ • During the era of the relational database, many more models had introduced like objectoriented model, object-relational model, etc. 5. Cloud database Cloud database facilitates you to store, manage, and retrieve their structured, unstructured data via a cloud platform. This data is accessible over the Internet. Cloud databases are also called a database as service (DBaaS) because they are offered as a managed service. Some best cloud options are: • AWS (Amazon Web Services) • Snowflake Computing • Oracle Database Cloud Services • Microsoft SQL server • Google cloud spanner Advantages of cloud database Lower costs Generally, company provider does not have to invest in databases. It can maintain and support one or more data centers.
electric pulses of varying amplitude. In digital technology, translation of information is into b... more electric pulses of varying amplitude. In digital technology, translation of information is into binary format (zero or one) where each bit is representative of two distinct amplitudes. Properties of Digital vs Analog signals Digital information has certain properties that distinguish it from analog communication methods. These include Synchronizationdigital communication uses specific synchronization sequences for determining synchronization. Languagedigital communications requires a language, which should be possess by both sender and receiver and should specify meaning of symbol sequences. Errorsdisturbances in analog communication causes errors in actual intended communication but disturbances in digital communication does not cause errors enabling error free communication. Errors should be able to substitute, insert or delete symbols to be expressed. Copyinganalog communication copies are quality wise not as good as their originals while due to error free digital communication, copies can be made indefinitely. Granularityfor a continuously variable analog value to be represented in digital form there occur quantization error which is difference in actual analog value and digital representation and this property of digital communication is known as granularity. Differences in Usage in Equipment Many devices come with built in translation facilities from analog to digital. Microphones and speaker are perfect examples of analog devices. Analog technology is cheaper but there is a limitation of size of data that can be transmitted at a given time. Digital technology has revolutionized the way most of the equipment's work. Data is converted into binary code and then reassembled back into original form at reception point. Since these can be easily manipulated, it offers a wider range of options. Digital equipment is more expensive than analog equipment. Comparison of Analog vs Digital Quality Digital devices translate and reassemble data and in the process are more prone to loss of quality as compared to analog devices. Computer advancement has enabled use of error detection and error correction techniques to remove disturbances artificially from digital signals and improve quality. Differences in Applications Digital technology has been most efficient in cellular phone industry. Analog phones have become redundant even though sound clarity and quality was good. Analog technology comprises of natural signals like human speech. With digital technology, this human speech can be saved and stored in a computer. Thus, digital technology opens up the horizon for endless possible uses. Data Communication Terminology Data Channel:-In this medium data carries from one point to another point. Baud:-Each communication channel has certain capacity and it can carry information up to that extent only. This capacity measured in terms of Baud. Bits per Second:-The speed at which data transferred between two points measured in terms of Bits per Second or bps. bpsbits per second, Bps-Bytes per second (Note capital B) Bandwidth-The amount of data a communication system can transfer per unit time referred as Bandwidth of the system. Bandwidth simply indicates the data transfer rate. The more the data needed to be transmitted in the given unit time the more should be the bandwidth. Alternatively, it can be said that more the bandwidth of the communication system more will be the data transfer rate. Bandwidth measured in bps or Baud. Generally, a Baud is identical to bits per second. A rate of 100 Baud is equal to 100 bps. In digital context, the level of bandwidth falls into three category: Narrowband-Speed of narrowband varies between 45 to 300 Baud. Low speed devices use this narrowband channels. Voice-band-Speed of voice-band channels ranges up to 9600 Baud. They are generally use in the ordinary telephone voice communication. Broadband-The speed of broadband channels ranges up to 1 million Baud or more. High-speed devices use broadband for large volume of data transfer at high rate. Broadcast television, microwave and satellite uses broadband channel. Data Transfer Rates:-The amount of data transferred per second by a communication channel is known as data transfer rate. It is measure in bits per second (bps). 1.3 Standard Organizations An association of organizations, governments, manufacturers and users form the standards organizations and are responsible for developing, coordinating and maintaining the standards .The purpose is that all data communications equipment are manufacturers and users comply with these standards. The primary standards organizations for data communication are:
1] Computer Network | Prepared by: Ashish Kr. Jha [2]
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Papers by ASHISH K U M A R JHA
Books by ASHISH K U M A R JHA