Tag: accountancy

An important application of cryptography, used in computerized commercial and financial transaction is Digital signature.

Digital signature:-

A digital signature is a mathematical scheme for presenting the authenticity of digital messages or documents. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, that the sender cannot deny having sent the message, and that the message was not altered in transit.

Cryptography:-

Cryptography is most often associated with scrambling plaintext (ordinary text, sometimes referred to as clear text) into cipher text (a process called encryption), then back again (known as decryption). 

Cryptography involves creating written or generated codes that allow information to be kept secret. Cryptography converts data into a format that is unreadable for an unauthorized user, allowing it to be transmitted without unauthorized entities decoding it back into a readable format, thus compromising the data.

Advantage of CMOS technology over a MOS is greater speed.

Complementary metal–oxide–semiconductor (CMOS) is a technology for constructing integrated circuit. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. 

The CMOS(complementary metal oxide semiconductor) technology is top in quality. Especially, when it comes to its features like low-static power utilization and noise resistance, CMOS technology conserves energy and it does not produce heat.

DCR is not changeable instruction.

DCR means Dynamic Contrast Ratio. Contrast ratio is the difference between light and dark on a screen, expressed by a number. If we take the brightest white on a screen, and the darkest black and compare the luminosity, we get the contrast ratio.

Design change request, also Document Change Request and Database Change Request.

Focus on manual records is not necessary for computerisation system in a bank.

Manual record keeping systems is keep invoicing, payment and other business transaction records electronically or manually. The principles are the same for each but keeping records electronically will make some important tasks easier.

IEEE 802-3 is Analog based non deterministic.

IEEE 802.3 is a working group and a collection of institute of electrical and electronic engineers (IEEE) standards produced by the working group defining the physical layer and data link layer’s media access control (MAC) of wired Ethernet. This is generally a local area network (LAN) technology with some wide area network (WAN) applications.

An example of digital rather than analog communication is DDS.

DDS:-

Direct digital synthesis (DDS) is a powerful technique used in the generation of radio frequency signals for use in a variety of applications from radio receivers to signals generators and many more. The technique has become far more widespread in recent years with the advances being made in integrated circuit technology that allow much faster speeds to be handled which in turn enable higher frequency DDS chips to be made.

Digital communication:-

Digital communication is a mode of communication. It occurs when the information or the thought is encoded digitally as discreet signals and then is electronically transferred to the recipients. Digital means of communication like messaging apps are surging in popularity all over the world.

Analog communication:-

Analog communication is a data transmitting technique in a format that utilizes continuous signals to transmit data including voice, image, video, electrons etc. An analog signal is a variable signal continuous in both time and amplitude which is generally carried by use of modulation.

6 bits are required to encode all 26 letters, 10 symbols and numerals.

If we want to represent one character from the 26-letter Roman alphabet (A-Z), then we need log2(26) = 4.7 bits. We will need 5 bits.

Resolution of 10 bit ADC is 1ms.

The only way to increase resolution without reducing the range is to use an ADC with more bits. A 10-bit ADC has 2^{^10}, or 1,024 possible output codes. There is no switching of IP channels and there is at least 1ms between enabling the ADC and starting the conversion.

The ADC reports a ratio metric value. This means that the ADC assumes 5V is 1023 and anything less than 5V will be a ratio between 5V and 1023. Analog to digital conversions are dependent on the system voltage.

An analog to digital converter (ADC) is an electronic device which converts varying analog signals into digital signals so that they can easily be read by the digital devices.

Keeping library in digital form is called digital library.

A digital library is an online database of digital objects that can include text, still images, audio, video, or other digital media formats. The digital content may be stored locally, or accessed remotely via computer networks.

A digital library is a collection of documents in organized electronic form, available on the Internet or on CD-ROM (compact-disk read-only memory) disks. Depending on the specific library, a user may be able to access magazine articles, books, papers, images, sound files, and videos.

IEEE S02.3 uses straight binary encoding with 0 volts for 0 bit and 5 volts for 1 bit.

It leads to ambiguities, for avoiding ambiguities. We used Manchester encoding and differential Manchester encoding.

Manchester encoding:-

Manchester encoding is a synchronous clock encoding technique used by the physical layer to encode the clock and data of a synchronous bit stream. In this technique, the actual binary data to be transmitted over the cable are not sent as a sequence of logic 1's and 0's.

Differential Manchester encoding:-

Differential Manchester encoding scheme is a line code in which data and clock signals are combined to form a single 2-level self-synchronizing data stream. It is a differential encoding, using the presence or absence of transitions to indicate logical value.

Baseband system:-

A baseband bandwidth is equal to the highest frequency of a signal or system, or an upper bound on such frequencies.