Thursday 11 October 2012

What is Queue Management System

A queue management system is used to control queues. Queues of people form in various situations and locations in a queue area. The process of queue formation and propagation is defined as queuing theory.

Queues exist in two main forms:

Structured queues

Here people form a queue in a fixed, predictable position, such as at supermarket checkouts, some other retail locations such as banks, airport security and so on. Very often, queue management systems are set up to manage ticket ranking for a service (with or without a numbered ticket) with identification and thus enable a stress-free waiting (without to wait in a queue, one behind the other). Extending the different possibilities, planned reception by appointment and remotely rank allocation on Smartphone or through SMS can also be included.

Unstructured queues

Where people form a queue in unpredictable and varying locations and directions. This is often the case in some forms of retail, taxi queues, ATMs and at periods of high demand in many situations. Nevertheless organizational systems exist to manage these cases: rank allocation for a service / need / salesperson or simply by reading the customer card. Although many have tried to implement a way of structuring these queues, no one has successfully implemented a management system that works.

"Queuing Theory : A. K. Erlang first studied and developed the fundamentals of queuing systems in the field of telephony. Many of his results are still in use today. In fact, the load on a circuit switching system is measured in Erlang.

Since Erlang’s time, the theory relating to queue properties has been developed, under the domain of Queuing Theory, over the last 70 years, and extensively so in the last 20 years.

The results of queuing theory apply to many seemingly unrelated situations, from serving customers at service counters to managing traffic congestion in a cosmopolitan city, and from designing switching equipment for telecommunications to understanding Internet behaviour."

Queue Management Solution:
The problem of serving customers in a specific sequence at business or public establishments has been solved in many different ways. Depending on available resources and technology, various mechanical, electronic and computerized systems have been designed and implemented.

The first objective of any queue management system is to achieve a better quality of service to customers. In its most basic form, a queue management system will issue a queue ticket to an arriving customer and later call the ticket when service is available, eliminating the need to stand in line while waiting. In this way, queue management systems help to provide comfort as well as fairness to customers, by allowing them to maintain their position in the queue while they are seated comfortably or engaged in constructive activity.
Modern queue management systems attempt to do more than that. Through the use of computerized systems, they help the management by producing statistical reports on information such as arrival rates and patterns, waiting and service times, and default and reneging cases. Based on these statistics, the optimal use of resources can be achieved, helping the trade-off between service quality and service cost. The latest Internet-enabled systems allow remote system monitoring, report generation and system configuration across an Internet link

Saturday 6 October 2012

How EAS System Works ?

A lack of understanding about how Electronic Article Surveillance or EAS works is most often the downfall in achieving the best results. The information below will help you understand how it all works together for optimum results. 

What is an EAS System?

Electronic Article Surveillance (EAS) is a technological method for preventing shoplifting.

It usually involves three components:

  • Electronic Antenna
  • Deactivator or Detacher
  • Electronic Tag or label

Special tags and labels are fixed to merchandise. These tags or labels are removed or "deactivated" by the clerks when the item is properly bought or checked out. 

Labels are deactivate using a "Label Deactivator". 

While ringing up purchases a cashier should pass each product label across the "Deactivation Pad". 

To remove a Hard Tag a cashier uses a "Detacher" which releases the pin. 

After a label is deactivated or a tag is removed the customer can then pass by the antenna without any alarm.

At the exits of the store, a detection system sounds an alarm or otherwise alerts the staff when it senses active tags are passing by. 

Types of EAS systems and how they work.

There are several major types of electronic article surveillance systems :

  1. Radio Frequency (RFiD)
  2. Acousto-magnetic (AM)
  3. Microwave

Radio-frequency (RFiD) Systems 

These tags are essentially an LC tank circuit.

An LC circuit is a resonant circuit or tuned circuit that consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C that has a resonance 

In physics, resonance is the tendency of a system to oscillate at larger amplitude at some frequencies than at others. These are known as the system's resonant frequencies . At these frequencies, even small periodic driving forces can produce large amplitude vibrations, because the system peak anywhere from 1.75 MHz to 9.5 MHz. The most popular frequency is 8.2 MHz. Sensing is achieved by sweeping around the resonant frequency and detecting the dip. Deactivation for 8.2 MHz label tags is achieved by detuning the circuit by partially destroying the capacitor.

A capacitor or condenser is a passive electronic component consisting of a pair of conductors separated by a dielectric. When a voltage potential difference exists between the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force. This is done by submitting the tag to a strong electromagnetic. 

Electromagnetism is the physics of the electromagnetic field, a field that exerts a force on particles with the property of electric charge and is reciprocally affected by the presence and motion of such particles field at the resonant frequency which will induce voltages exceeding the capacitor's breakdown voltage. 

The breakdown voltage of an Insulator is the minimum voltage that causes a portion of an insulator to become electrically conductive.The breakdown voltage of a diode is the minimum reverse voltage to make the diode conduct in reverse which is artificially reduced by puncturing the tags.


Acousto-magnetic (AM)

These tags are similar to magnetic tags in that they are made of two strips, a strip of magnetostrictive. 

Magnetostriction is a property of ferromagnetic materials that causes them to change their shape when subjected to a magnetic field. The effect was first identified in 1842 by James Joule when observing a sample of nickel called ferromagnetic. 

Ferromagnetism is the basic mechanism by which certain materials form permanent magnets and/or exhibit strong interactions with magnets; it is responsible for most phenomena of magnetism encountered in everyday life called amorphous metal. 

An amorphous metal is a metallic material with a disordered atomic-scale structure. In contrast to most metals, which are crystalline and therefore have a highly ordered arrangement of atoms, amorphous alloys are non-crystalline and a strip of a magnetically semi-hard metallic strip, which is used as a biasing magnet (to increase signal strength) and to allow deactivation. These strips are not bound together but free to oscillate mechanically.

Amorphous metals are used in such systems due to their good magnetoelastic coupling, which implies that they can efficiently convert magnetic energy to mechanical vibrations.

The detectors for such tags emit periodic tonal bursts at about 58 kHz, the same as the resonance.

In physics, resonance is the tendency of a system to oscillate at larger amplitude at some frequencies than at others. These are known as the system's resonant frequencies . At these frequencies, even small periodic driving forces can produce large amplitude vibrations, because the system frequency of the amorphous strips. This causes the strip to vibrate longitudinally by magnetostriction, and will continue to oscillate after the burst is over. The vibration causes a change in magnetization in the amorphous strip, which induces an AC voltage in the receiver antenna. If this signal meets the required parameters (correct frequency, repetition etc.) the alarm is activated.

When the semi-hard magnet is magnetized, the tag is activated. The magnetized strip makes the amorphous strip respond much more strongly to the detectors, because the DC magnetic field given off by the strip offsets the magnetic anisotropy. 

Magnetic anisotropy is the direction dependence of a material's magnetic properties. A magnetically isotropic material has no preferential direction for its magnetic moment in zero field, while a magnetically anisotropic material will align its moment to an easy axis.-Sources of magnetic within the amorphous metal. The tag can also be deactivated by demagnetizing the strip, making the response small enough to that it will not be detected by the detectors.

These tags are thicker than other tags and are thus seldom used for books. However they are relatively expensive and have better detection rates (fewer false positives and false negatives) than RFiD tags.

Acousto-Magnetic EAS System

Microwave EAS Systems 

These permanent tags are made of a non-linear element called a Diode.

In electronics a diode is a two-terminal electronic component which conducts electric current asymmetrically or unidirectional; that is, it conducts current more easily in one direction than in the opposite direction. The term usually refers to a semiconductor diode, the most common type today, coupled to one microwave and one electrostatic antenna. 

At the exit, one antenna emits a low-frequency (about 100 kHz) field, and another one emits a microwave field. 

The tag acts as a mixer re-emitting a combination of signals from both fields. This modulated signal triggers the alarm. These tags are permanent and somewhat very costly. They are mostly used in clothing stores.

Friday 5 October 2012

Electronic Article Surveillance (EAS)

Security experts say the most effective anti-shoplifting tools these days are CCTV and the tag-and-alarm systems, better known as electronic article surveillance (EAS) systems. Separately, these are good options. Used together, experts say, they're almost unbeatable. EAS is a technology used to identify articles as they pass through a gated area in a store. This identification is used to alert someone that unauthorized removal of items is being attempted. According to the Association of Automated Identification Manufacturers, over 800,000 EAS systems have been installed worldwide, primarily in the retail arena. EAS systems are useful anywhere there is an opportunity for theft of items of any size. Using an EAS system enables the retailer to display popular items on the floor, where they can be seen, rather than putting them in locked cases or behind the counter.

Loss prevention expert says new EAS technologies are being produced -- not only to reduce shoplifting -- but also to help increase sales, lower labor costs, speed inventory, improve stockroom logistics and, one day, to replace inventory record-keeping. But for now, we'll stick to the role of EAS in battling shoplifting in your imaginary store!

Many types of EAS systems dominate the retail industry. In each case, an EAS tag or label is attached to an item. The tag is then deactivated, or taken from an active state where it will alarm an EAS system to an inactive state where it will not flag the alarm. If the tag is a hard, reusable tag, a detacher is used to remove it when a customer purchases the item it's attached to. If it's a disposable, paper tag, it can be deactivated by swiping it over a pad or with a handheld scanner that "tells" the tag it's been authorized to leave the store. If the item has not been deactivated or detached by the clerk, when it is carried through the gates, an alarm will sound.

The use of EAS systems does not completely eliminate shoplifting. However, experts say, theft can be reduced by 75 percent or more when a reliable system is used. Even when a shoplifter manages to leave the store with a tagged item, the tag still must be removed -- something that is no longer as easy as it once was. For example, some EAS tags contain special ink capsules, which will damage the stolen item when forcibly, and illegally, removed. (This type of device is known in the industry as benefit denial. Other popular EAS components today include source tagging, whereby an inexpensive label is integrated into the product or its packaging by the manufacturer.

The type of EAS system dictates how wide the exit/entrance aisle may be, and the physics of a particular EAS tag and technology determines which frequency range is used to create a surveillance area. EAS systems range from very low frequencies through the radio frequency range (see How Radio Scanners Work). These EAS systems operate on different principles, are not compatible and have specific benefits and disadvantages. That's why the Consumer Products Manufacturers Association is encouraging a "tower-centric" EAS approach that can "read" multiple tag technologies rather than the "tag-centric" models that exist today.