Download Full Article Voice User Interface

Definition

In its most generic sense a voice portal can be defined as “speech enabled access to Web based information”. In other words, a voice portal provides telephone users with a natural language interface to access and retrieve Web content. An Internet browser can provide Web access from a computer but not from a telephone. A voice portal is a way to do that.

Overview

The voice portal market is exploding with enormous opportunities for service providers to grow business and revenues. Voice based internet access uses rapidly advancing speech recognition technology to give users any time, anywhere communication and access-the Human Voice- over an office, wireless, or home phone. Here we would describe the various technology factors that are making voice portal the next big opportunity on the web, as well as the various approaches service providers and developers of voice portal solutions can follow to maximize this exciting new market opportunity.

Why Voice?

Natural speech is modality used when communicating with other people. This makes it easier for a user to learn the operation of voice-activate services. As an output modality, speech has several advantages. First, auditory input does not interfere with visual tasks, such as driving a car. Second, it allows for easy incorporation of sound-based media, such as radio broadcasts, music, and voice-mail messages. Third, advances in TTS (Text To Speech) technology mean text information can be transferred easily to the user. Natural speech also has an advantage as an input modality, allowing for hands-free and eyes-free use. With proper design, voice commands can be created that are easy for a user to remember .These commands do not have to compete for screen space. In addition unlike keyboard-based macros (e.g., ctrl-F7), voice commands can be inherently mnemonic (“call United Airlines”), obviating the necessity for hint cards. Speech can be used to create an interface that is easy to use and requires a minimum of user attention.

VUI (Voice User Interface)

 For a voice portal to function, one of the most important technology we have to include is a good VUI (Voice User Interface).There has been a great deal of development in the field of interaction between human voice and the system. And there are many other fields they have started to get implemented. Like insurance has turned to interactive voice response (IVR) systems to provide telephonic customer self-service, reduce the load on call-center staff, and cut overall service costs. The promise is certainly there, but how well these systems perform-and, ultimately, whether customers leave the system satisfied or frustrated-depends in large part on the user interface.

Many IVR applications use Touch-Tone interfaces-known as DTMF (dual-tone multi-frequency)-in which customers are limited to making selections from a menu. As transactions become more complex, the effectiveness of DTMF systems decreases.

In fact, IVR and speech recognition consultancy Enterprise Integration Group (EIG) reports that customer utilization rates of available DTMF systems in financial services, where transactions are primarily numeric, are as high as 90 percent; in contrast, customers’ use of insurers’ DTMF systems is less than 40 percent.
Enter some more acronyms. Automated speech recognition (ASR) is the engine that drives today’s voice user interface (VUI) systems. These let customers break the ‘menu barrier’ and perform more complex transactions over the phone. “In many cases the increase in self-service when moving from DTMF to speech can be dramatic,” said EIG president Rex Stringham.

The best VUI systems are “speaker independent”-they understand naturally spoken dialog regardless of the speaker.  And that means not only local accents, but regional dialects, local phrases such as “pop” versus “soda,” people who talk fast (you know who you are), and all the various nuances of speech. Those nuances are good for human beings; they allow us to recognize each other by voice. For computers, however, they make the process much more difficult. That’s why a handheld or pocket computer still needs a stylus, and why the ‘voice dialing’ offered by some cell-phone companies still seems high-tech.

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Download Full Article Voice Over Internet Protocol

I N T R O D U C T I O N

Using an ordinary phone for most people is a common daily occurrence as is listening to your favorite CD containing the digitally recorded music. It is only a small extension to these technologies in having your voice transmitted in data packets. The transmission of voice in the phone network was done originally using an analog signal but this has been replaced in much of the world by digital networks. Although many of our phones are still analog, the network that carries that voice has become digital.

In todays phone networks, the analog voice going into our analog phones is digitized as it enters the phone network. This digitization process, shown in Figure 1 below, records a sample of the loudness (voltage) of the signal at fixed intervals of time. These digital voice samples travel through the network one byte at a time.

At the destination phone line, the byte is put into a device that takes the voltage number and produces that voltage for the destination phone. Since the output signal is the same as the input signal, we can understand what was originally spoken.
The evolution of that technology is to take numbers that represent the voltage and group them together in a data packet similar to the way computers send and receive information to the Internet. Voice over IP is the technology of taking units of sampled speech data .

So at its most basic level, the concept of VoIP is straightforward. The complexity of VoIP comes in the many ways to represent the data, setting up the connection between the initiator of the call and the receiver of the call, and the types of networks that carry the call.

Using data packets to carry voice is not just done using IP packets. Although it won’t be discussed, there is also voice over Frame Relay (VoFR) and Voice over ATM (VoATM) technologies. Many of the issues VoIP being discussed also apply to the other packetized voice technologies.

The increasing multimedia contents in Internet have reduced drastically the objections to putting voice on data networks. Basically, the Internet objections to putting voice on data networks. Basically, the Internet Telephony is to transmit multimedia information in discrete packets like voice or video over Internet or any other IP-based Local Area Network (LAN) or Wide Area Network (WAN). The commercial Voice Over IP (Internet Protocol) was introduced in early 1995 when VocalTec introduced its Internet telephone software. Because the technologies and the market have gradually reached their maturity, many industry leading companies have developed their products for Voice Over IP applications since 1995.

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Download Full Article  Virtual LAN

                        In today’s networked backbone, there are certain hardware devices that connect other networks to the backbone. These are special purpose devices and computers that just transfer messages from one network to another. Before we look deep into the topic Virtual LAN’s, let us see the basic devices used in the network backbone. They are

1. Bridges.

                                           2. Switches.

3. Routers.

4. Gateways.

5. Hubs.

BRIDGES-Bridges operate at the data link layer.  They connect two LAN segments that use the same data link and network protocol.  They may use the same or different types of cables.  Bridges “learn” whether to forward packets, and only forward those messages that need to go to other network segments.

                        If a bridge receives a packet with a destination address that is not in the address table, it forwards the packet to all networks or network segments except the one on which it was received. Bridges are a combination of both hardware and software, typically a “black box” that sits between the two networks, but can also be a computer with two NICs and special software.

SWITCHES-Like bridges, switches operate at the data link layer. Switches connect two or more computers or network segments that use the same data link and network protocol. They may connect the same or different types of cable. The switch is a device that connects a material coming in with an appropriate outlet. They require more processing power. Switches operate at the same layers as bridges but differ from them in two ways:

1. First, most switches enable all ports to be in use simultaneously, making them faster than bridges.

2. Second, unlike bridges, switches don’t learn addresses, and need to have addresses defined.

There are two types of switches:

1. Cut-through switches examine the destination of the incoming packet and immediately connect the port with the incoming message to the correct outgoing port. It is hardware-based.

2. Store-and-forward switches copy the incoming packet into memory before processing the destination address.

ROUTERS-Routers operate at the network layer.  Routers connect two or more LANs that use the same or different data link protocols, but the same network protocol.  Routers may be “black boxes,” computers with several NICs, or special network modules in computers.

In general they perform more processing on each message than bridges and therefore operate more slowly.

                        Routers can choose the best route when compared with bridges .They only process messages specifically addressed to it. Routers can connect networks using different data link layer protocols. Therefore, routers are able to change data link layer packets. Routers may split a message into several smaller messages for better transmission.

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Download Full Article  Tiger SHARC processor

In the past three years  several multiple data path and pipelined digital signal processors have been introduced into the marketplace. This new generation of DSP’s takes advantage of higher levels of integrations than were available for their predecessors. The Tiger SHARC processor is the newest and most power member of this family which incorporates many mechanisms like SIMD, VLIW and short vector memory access in a single processor. This is the first time that all these techniques have been combined in a real time processor.

The TigerSHARC DSP is an ultra high-performance static superscalar architecture that is optimized for tele-communications infrastructure and other computationally demanding applications. This unique architecture combines elements of RISC, VLIW, and standard DSP processors to provide native support for 8, 16, and 32-bit fixed, as well as floating-point data types on a single chip.

Large on-chip memory, extremely high internal and external bandwidths and dual compute blocks provide the necessary capabilities to handle a vast array of computationally demanding, large signal processing tasks.            

2. DIGITAL SIGNAL PROCESSOR

Strictly speaking, the term “DSP” applies to any microprocessor that operates on digitally represented signals. In practice, however, the term refers to microprocessors specifically designed to perform digital signal processing tasks. Because most signal processing systems perform complicated mathematical operations on real-time signals, DSPs use special architectures to accelerate repetitive, numerically intensive calculations. For example, DSP architectures commonly include circuitry to rapidly perform multiply accumulate operations, which are useful in many signal-processing algorithms. Also, DSPs often contain multiple-access memory architectures that allow the processor to simultaneously load multiple operands. In addition, DSPs often include a variety of special memory addressing modes and program-flow control features designed to accelerate the execution of repetitive operations. Lastly, most DSP processors include specialized on-chip peripherals or I/O interfaces that allow the processor to efficiently interface with other system components, such as analog-to-digital converters and host processors.

Before going into the details of the Tiger SHARC architecture let us familiarize with a few architectural techniques which are the key elements of this new DSP.

1. VLIW- Very Long Instruction Word

VLIW points to the instructions that specify more than one concurrent operation in a single instruction. The following features characterize it: -

Ø    Instruction width is quite large taking many bits to encode multiple operations.

ØRely on software to pack the collection of operation (compaction).

ØIn code with limited instruction parallelism, most of the instruction is wasted with no operation.

2. SIMD: - Single Instruction Multiple Data

A very important class of architectures in the history of computation, single-instruction/multiple-data machines is capable of applying the exact same instruction stream to multiple streams of data simultaneously. For certain classes of problems, e.g., those known as data-parallel problems, this type of architecture is perfectly suited to achieving very high processing rates, as the data can be split into many different independent pieces, and the multiple instruction units can all operate on them at the same time.

                        SIMD (Single-Instruction Stream Multiple-Data Stream) architectures are essential in the parallel world of computers. Their ability to manipulate large vectors and matrices in minimal time has created a phenomenal demand in such areas as weather data and cancer radiation research. The power behind this type of architecture can be seen when the number of processor elements is equivalent to the size of your vector. In this situation, component wise addition and multiplication of vector elements can be done simultaneously. Even when the size of the vector is larger than the number of processors elements available, the speedup, compared to a sequential algorithm, is immense. There are two types of SIMD architectures. The first is the True SIMD followed by the Pipelined SIMD. Each has its own advantages and disadvantages but their common attribute is superior ability to manipulate vectors.

            The CPU can perform high-speed arithmetic operations within one instruction cycle because of its parallel and combinational architectural design. There are two execution units in the processor in order to facilitate the SIMD mode of operation of the processor. Only one execution unit is used in case of SISD operation. The SIMD mode is characterized by multiple instances of the same operation on different data.

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Download Full Article Small Computer System Interface

SCSI is actually an acronym for Small Computer System Interface and it is pronounced as “skuzzy”. It is the second-most popular hard disk interface used in PCs today. It’s a high-speed, intelligent peripheral I/O bus with a device independent protocol for transferring data between different types of peripheral devices. The SCSI bus connects all parts of a computer system so that they can communicate with each other. The bus frees the host processor from the responsibility of I/O internal tasks. A SCSI bus can be either internal, external, or cross the boundary from internal to external. The SCSI protocol is a peer-to-peer relationship: one device does not have to be subordinated to another device in order to perform I/0 activities. Only two of these devices can communicate on the bus at any given time.

          Each SCSI bus can connect up to 8 or up to 16 peripherals; one of those devices will always be the computer or the SCSI card, because they too are devices on the SCSI. SCSI devices are designated as either initiators (drivers) or targets (receivers) and the interface to the host computer is called the host adapter. Every device connected to the bus will have a different SCSI ID, ranging from 0 to 7. The host adapter takes up one ID leaving 7 ID’s for other hardware. SCSI hardware typically consists of hard drives, tape drives, CD-ROMs, printers and scanners. .

The reason for the slow taking of SCSI is the lack of standard. Each company seems to have its own idea of how SCSI should work. While the connections themselves have been standardized, the actual driver specs used for communication have not been. The end result is that each piece of SCSI hardware has its own host adapter. So, due to the lack of an adapter standard, a standardized software interface, and a standard BIOS for hard drives attached to the SCSI. Adapter.

History & Evolution

In the beginning, one couldn’t even use a hard drive on the bus. This was mainly because the BIOS in those systems were designed to use the ST506/412 controller. With the IDE, the BIOS was easily changed because of the similarity to ST506/412 on the WD1003 controller. At the register level, though, SCSI was very different, and would have required an entirely new set of BIOS in the PC.

What we currently know of as the SCSI interface had its beginnings back in 1979. Shugart Associates, led by storage industry pioneer Alan Shugart (who was a leader in the development of the floppy disk, and later founded Seagate Technology) created the Shugart Associates Systems Interface (SASI). This very early predecessor of SCSI was very rudimentary in terms of its capabilities, supporting only a limited set of commands compared to even fairly early “true” SCSI, and rather slow signaling speeds of 1.5 Mbytes/second. For its time, SASI was a great idea, since it was the first attempt to define an intelligent storage interface for small computers. The limitations must be considered in light of the era: we are talking about a time when 8″ floppy drives were still being commonly used.

Shugart wanted to get SASI made into an ANSI standard, presumably to make it more widely-accepted in the industry. In 1981, Shugart Associates teamed up with NCR Corporation, and convinced ANSI to set up a committee to standardize the interface. In 1982, the X3T9.2 technical committee was formed to work on standardizing SASI. A number of changes were made to the interface to widen the command set and improve performance. The name was also changed to SCSI; I don’t know the official reason for this, but I suspect that having Shugart Associates’ name on the interface would have implied that it was proprietary and not an industry standard. The first “true” SCSI interface standard was published in 1986, and evolutionary changes to the interface have been occurring since that time.

It’s important to remember that SCSI is, at its heart, a system interface, as the name suggests. It was first developed for hard disks, is still used most for hard disks, and is often compared to IDE/ATA, which is also used primarily for hard disks. For those reasons, SCSI is sometimes thought of as a hard disk interface. However, SCSI is not an interface tied specifically to hard disks. Any type of device can be present on the bus, and the very design of SCSI means that these are “peers” of sorts–though the host adapter is sort of a “first among equals”.  SCSI was designed from the ground up to be a high-level, expandable, high-performance interface. For this reason, it is frequently the choice of high-end computer users. It includes many commands and special features, and also supports the highest-performance storage devices.

Of course, these features don’t come for free. Most PC systems do not provide native, “built in” support for SCSI the way they do for IDE/ATA, which is one of the key reasons why SCSI isn’t nearly as common as IDE/ATA in the PC world. Implementing SCSI on a PC typically involves the purchase of a storage device of course, but also a special card called a host adapter. Special cables and terminators may also be required. All of this means that deciding between SCSI and IDE/ATA is an exercise in tradeoffs.

SCSI began as a parallel interface, allowing the connection of devices to a PC or other systems with data being transmitted across multiple data lines. Today, parallel or “regular” SCSI is still the focus of most SCSI users, especially in the PC world. SCSI itself, however, has been broadened greatly in terms of its scope, and now includes a wide variety of related technologies and standards, as defined in the SCSI-3 standard. Many high-end systems have built-in SCSI support. There is usually an adapter card or an adapter built in to the motherboard. This native support for SCSI was set in motion by IBM. Their example was followed by many manufacturers. As a result, SCSI integration is becoming very easy to work with and will get easier as technology progresses.

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