Most Ignored CCTV Codes and Laws

with ref http://arindamcctvaccesscontrol.blogspot.in/2012/03/cctv-data-protection-act.html

artical we discuss Most Ignored CCTV Codes and Laws.

Let’s be honest, not all security integrators and installers take the proper precautions to make sure they aren’t violating any CCTV “laws” before installing. Many install them on the notion of protecting property, keeping an eye on employees, or some other common video surveillance goal. We forget that there are rules that we need to follow. It’s all fun and games until you go to court for misuse of CCTV video. Below you will find a list of 10 most ignored Codes or Laws for security camera usage for the distributor and the consumer. So avoid getting in trouble by taking a look at this list of laws and code of conduct.

What are the most ignored CCTV codes?

Staff should be informed of any cameras placed in their working area:

This is a courtesy act, but is not required, unless the cameras are observing unionized  labor workers. In the case of a union, they must be notified if a hidden camera is going to be installed and used. Cameras are usually placed in working areas to keep employees on their best behavior, and warning them they are being watched is only fair. Some employment contracts may include a clause about hidden cameras.

Sales staff should inform the consumer of the advantages and weaknesses of each product:
Not all customers are tech savvy and know how to read spec sheets, so it is the salesperson’s responsibility to inform (enlighten) the client of such things. This is often overlooked and ignored. Some Technical background Sales people / Technician or Engineer always offers the best products, and will list for you any disadvantages a product has.

Sales Staff need to communicate to the customer how to maintain product:
This includes how to clean it and how to install it in order to keep the product working and in good shape.  Some expert sales staff always educates there customers on products and are trained to ask about the area the camera will be installed in to give corresponding care instructions.

Police are limited in their surveillance operations:
Because of the fourth amendment, police cannot install cameras with audio surveillance without a warrant. For instance, installing ‘bugs’ for investigations may be permissible if they have a probable cause. A public phone booth, however, is a place where installing audio surveillance is not permissible.

Except for law enforcement purposes, footage should not be given to any other third party:
This code is completely disregarded. Sometimes videos are posted online for entertainment or other purposes. If you go to Youtube and search CCTV, you will find many videos there, which is in complete violation of this code.

Although nannies do not have to be notified, it is still courteous to tell her she is being observed:
The footage of the nanny abusing the child was used as evidence even though it came from a hidden camera. This was ruled under the notion that one should not expect privacy in other people’s homes.

Cameras should be positioned only to view the premises:
Anything outside of your property is not your business, so anybody not visiting your property should not be caught on your footage. Some states prohibit cameras from pointing into other people’s houses or backyards, as it is a violation of privacy.  You can use Privacy Making to block out sensitive areas that you do not wish to monitor.

Some states require security cameras in certain areas:
Some states, require the installation of cameras at certain cabarets and public dance halls. This is required in the case of a crime, and is given to the cops immediately for investigation.

Regardless of the state, it is almost always illegal to record a conversation to which you are not a party, do not have consent to tape, and could not naturally overhear (RCFP):
This means any situation in which you would have eavesdropped on that conversation but recorded it, is illegal. In the following states, the one recording must notify everyone being recorded that the recording is taking place: Mumbai, Chennai, Bengaluru, Kolkata & New Delhi.

It is prohibited to place hidden cameras in private places:
In some states prohibit the placement and use of covert cameras without the permission of those being recorded. They must be warned that they are being watched and recorded. So what is a private place? It is anywhere where the person has an expectation of privacy, or outside of the public sector, i.e., bathroom, locker room, hotel room, or fitting room.

So when you are installing your surveillance system, make sure to continue by these rules. This will ensure your videos will be admissible as evidence in a court of law. When signing your employment contract, pay attention to the small things they add in there.

Multiple CCTV Camera Over Single Coax

This equipment allow the user to send multiple video signals over a single coax cable. Perfect solution to applications where additional cameras are needed, but only a single coax cable is available. Simply attach each camera to a unique single channel injector, then use a combiner to send them all together. Additional injectors may be added and combined anywhere along the cable to add additional cameras. The video extractors are available in 4, 8, & 16 channels, and may also be placed anywhere along the coax run to selectively extract the desired cameras at that location. The out of box Video signal strength allows for runs up to 1000 ft. and beyond. Amplifiers are available if greater distances are required.

Image quality plummets for CCTV systems that extend beyond about 200 meters. Strengthening transmission signals over coax requires expensive amplification, fault correction and surge protection technology. As a result, more security professionals are choosing Transition Networks media converters to leverage their existing copper network infrastructure and add fiber optics capabilities for maximum video security performance.

Benefits of fiber:-

• Extend video coverage without any signal degradation up to 10km (6.2 miles).
• More bandwidth for next-generation equipment and applications.
• Immune to electrical interference that could degrade signal or cause interference.

What’s New in SQL Server 2014 since SQL Server 2012

What’s New in SQL Server 2014 since SQL Server 2012

PERFORMANCE & SCALE

o        In-Memory OLTP

o        Enhanced In-Memory ColumnStore for DW

o        Buffer Pool Extension to SSDs

o        Enhanced Query Processing

o        Resource Governor adds IO governance

o        SysPrep at cluster level

o        Predictable performance with tiering of compute, network, and storage with Windows Server 2012 R2.

HIGH AVAILABILITY

o        Enhanced AlwaysOn, with 8 secondaries and Replica Wizard

o        Delayed Durability

o        Clustered Shared Volume support, VHDX support (Windows Server 2012 R2)

o        Manage on-premises and cloud apps (System Center 2012 R2)

SECURITY

o        Enhanced separation of duty

o        CC certification at High Assurance Level for 2014

o        Backup encryption support

PROGRAMMABILITY

o        Query optimization enhancements

EASY ACCESS TO DATA, BIG & SMALL

o        Power Query

o        Windows Azure HDInsight Service

o        Analytics Platform System (PDW V2)

POWERFUL INSIGHTS WITH FAMILIAR TOOLS

o        Power BI in Office 365

o        Power Map for Excel

o        Mobile interfaces for Power BI

HYBRID CLOUD SOLUTIONS

o        Simplified backup to Windows Azure

o        Support for backup of previous versions of SQL Server to Windows Azure

o        Cloud back-up encryption support

o        Simplified cloud Disaster Recovery with AlwaysOn replicas in Windows Azure VMs

EASY ON-RAMP TO THE CLOUD

o        New Windows Azure Deployment UI for SQL Server

o        Larger SQL Server VMs and memory sizes now available in Windows Azure

This list also includes some technologies that work together with SQL Server such as Azure, System Center, Excel 2013, Power BI for Office 365 and others.

Ground loop problems in Camera output

Ground loops effect in video output

As the source and destination of a video signal can be at differing ac or dc earth potentials, earth loop currents flow and cause longitudinal hum to be introduced into the video signal. Video hum is low frequency (50 or 60 Hz mains frequency or it's harmonics) noise from the ground lines which has influenced the video signal, causing degradation of the displayed signal. Video hum is usually observed as bars rolling vertically through the video image, video hum may also cause video distortion or even tearing of the picture in severe cases. Video hum maybe a problem in any system where video sources and display devices are connected to different A/C power sources with varying grounding potentials.

Typically the humming can be seen as slowly vertically moving horizonal bars in normal TV video signals. The same kind of bars can be also seen in computer screen, but typically they are not as visible because bars are moving so fast that you see them as some strange flashing in screen.

The picture below is a real world example of the effects of a ground loop and what it causes a a video picture received from the cable TV network:

Ad you can see that video signal has strong hummign bars and other interference in it. Those have entered the cable TV signal because of ground loops in the system. Ground loops in the video systems can have following effects:

•Hum Bars: The mains frequency (50 Hz or 60 Hz) can cause stationaly or moving horizonal humming bar to appear on the video signal (as shown on the picture above). If you have light dimmers nearby those humming bars can easily become quite severe and easily visible.

•RF Interference: Herring bone interference on video line is caused by a ground loop (that includes your coax shield) acting as an AM radio antenna. Any large loop of wire makes a good AM antenna. These antennas are especially adept at picking up AM broadcasts if most of the loop is vertical.

•Cross-Talk: Ground loops can cause one signal to interfere with another, because every cable should ideally return through the corresponding shield conductor, but there's an alternative path through the other shield conductor which causes undesirable voltage differences to nearby cables.

Isolating video signal is more complicated than isolating audio or antenna signals, because the DC level of the video signal is important and video signals have very high frequency spectrum (normal composite video can have bandwidth from 50 Hz to 6 Mhz).

Isolating video signal needs typically active technology which involves electro-optical isolation or differential amplifier with a floating ground on the input connector. Those both technologies are usable in real world situations. Differential input with floating ground works nicely for small ground potential differences and this approach is used in some professiona video equipments (some video projectors I have seen have had differential inputs and option to disconnect input ground connection). Differential inputs are also used in applications where a video signal is transmitted through twisted pair wiring (some CCTV applications which use twisted pair interfacing equipments).

Electro-optical isolation works well in applications where complete electrical isolation is necessary. There are some this type of isolation devices on the market and some special video distribution amplifiers have this kind of option built in.

Ground loop elemination does not always ask for a complete isolation of the grounds. There are passive hum suppressor transformers which will very effectively remove the hum from the video signal (typically around 40 dB hum level reduction), but do not effect the video signal otherwise. Those special transformers act like a common mode coils, which stop the annoying ground loop currents on the shield of the coaxial calbe, but provide a straight path for the signal inside the cable. This kind of devices are capable of passing the signals from DC to tens of MHz without problems. This type of hum suppression transformers have found their way to the professional video application (rental companies) and comouter video applivations (computer to video projector connections). The transformers of this type are usually called "hum bug transformers", "humbucking transformers", "anti-hum video transformers" or "hum suppressor transformers". Generally term hum-bugger refers to any circuit (often a special coil) that introduces a small amount of voltage at power-line frequency into the video path to cancel unwanted ac hum.

There are also special wideband isolation transformer which can isolate video signals. A transformer which can nicely transfer the whole video frequency spectrum without much distortion is very hard to produce so there are not many of them on the market. Some of the isolation transformers are only designed for CCTV application, where more signal distortion is accepted than in broadcast industry.

The choke (humbugging transformer) is primarily used in Broadcast TV because it passes the DC component of the signal. It is used in studio, and in remote ENG. The isolation transformer is primarily used in CCTV: security, manufacturing, avionics, display, etc.

Differential video amplifiers

Differential amplifier approach uses an operational Amplifier. Operational Amplifiers only amplify the difference between the two input lines. This method eliminates common mode noise between the incoming signals by making A-B=C, as only the difference between A & B are amplified. Operational amplifiers is maintain wide bandwidth signals throughout your system while eliminating ground loop problems that are caused by power and video. Diffeerential video amplifier inputs are used in some video equipments (typically some video projectors) and video distribution amplifiers to fight against ground loop problems.

Differential video amplifiers have a limitation on their input voltage range which gives some limitations how much common mode signal those circuits can tolerate. If the ground potential difference is more than few volts, then operational amplifier based isolators don't work effectively. Too high voltage difference can cause problems from very distorted video signal to damaged differential video amplifier. If the voltage difference is a substantial proportion of the DC supply voltage of the amplifier, you will probably have trouble using an amplifier alone.

It is a good idea to measure the voltage difference before using differential video amplifiers to be sure not to damagze them. Measuring can be done using a multimeter (check using both AC and DC ranges) or better using a scope earthed to the mains supply, and put the probe on the earth connection of the incoming video cable. If you many potential difference which are many volts, then you have quite propably something wrong in the grounding of the building and you should consult a qualified electrician to check and correct this potentially dangerous problem.

Good back porch black level clamp

If the video signal input has well designed fast black level clamp circuitry that can also solve small common mode noice problems caused by ground loop. Back porch ground level clamp circuit adjusts the black level of the video circuits according the incoming video signal. If black level clamp circuit is active circuitry which samples the black level saparately for every can line the ground loop bars are quite effectively eliminated because the the low frequency noise (50 Hz power or harmonics) is sampled at start of every scan line and suppressed then from the rest of the line. This works quite nicely with those low frequency humming bars, especially if combined with differential video inputs. back porch black level clamp system does not help in fighting against higher frequency noise which might be injected to the video system through the ground loop.

Active video isolators

Video Isolator passes a video signal from its input to its output with no electrical connection and is able to provide complete isolation, for the video signal, passing through it. Having the Video Isolator in the video signal path makes it possible to have Standard Safety earthing of all equipment with no associated earth loop problems. In the studio, feeds between different buildings are no longer a problem and it is no longer necessary to run technical earth to non critical locations such as viewing rooms.

Electro-optical isolators convert video signal voltage to blinking LED and other part of the circuit receives that light and convert it to back video signal voltage. This method guarantees very good isolation (complete galvanic isolation), but has typically bandwidth and linearity problems. Poor bandwidth will result in fuzzy images and poor linearity will result in an inability to produce the same gain for all signal levels (most noticeable in gray-scale patters).

Anti-hum video transformers

Anti-hum video transformers are not real transformers, they are common mode chokes! Anti-hum transformers work as a series inductor offering a series impedance to the circulating earth currents thus effectively reducing the current flowing in the loop which will reduce the voltage dops on the cable shields and equipment (that reduces hum). Those coils can reduce the currents on cable shield very effectively because they have very high impedance at 60 Hz and above and there presents a high impedance to common mode signal differentials between the input and output. Earth loops typically have low resistance a quite the inductance will not have to be very huge to start to help. The coil itself will then have quite much voltage difference on the input and output grounds (the potential difference is now over the transformer insted of distributed to whole cable), but the common mode coil construction guarantees that this difference is not supped to the differential signal inside the cable. Since the signal and ground lead are coincident, the differential signal is unaffected.

Hum reduction transformers or common mode coils are constructed with either 75 Ohm twisted pair (made of fine wire) or coaxial cable wrapped around a very high permeability core. Most basic hum isolation transformers are basically just coax cable wound on a toroid-type core. They work by mutual inductance. The coax cable is wound around a transformer core so that both the inner and shield of the cable become inductors. The tight coupling ensures that any voltage in the shield caused by variations in earth potential are transformed into the inner conductor.

The method is an ancient idea and can cope with very large ground loop signals, and has very large bandwidth with very little loss. This type of anti-humming transformer also provides DC continuity between the input and output leads which is a good thing. transformer does not stop ground loop current flowing (the amout of current is lower bause the added indictance) but the transformer reduces the current cancel the effect of ground loop current. Good one can reduce the ground loop effect up to 40-50 dB.

Hum isolation transformers are effective solutions for hummign problems. The downside of them is that they are somehow bulky devices because of the large core needed to do the job. The boxes I have seen have been packed in metal case have weighted at least one kilogram. Hum isolation transformers are typically stand-alone passive boxes which are added to video system when problems are encountered.

Video isolation transformers

There are special wideband isolation transformer which can isolate video signals, but not without problems. The design of a high bandwidth transformer which can go to very low frequencies is very hard. You have to always make some compromises on low and high frequency responses (highest components of composite video cna be attenuated even few dB). All real isolation transformers have one serious drawback which can't be avoided: they can't pass the DC level through. So any system that relies on the video having any particular DC reference will not function properly. There are many video systems around which need particular DC reference level, but there are many which are AC coupled.

Some of the isolation transformers are only designed for CCTV other not so demanding applications application, where more signal distortion is accepted than in broadcast industry. So a video isolation transformer might be OK for a security camera installation if a complete isolation is needed, but I would not put it on any professional video studio system. 

CMOS Sensor Operation in Camera

Until recently the industrial digital vision sensor market was dominated by the CCD array. However technological advances in CMOS production techniques have led to a gradual increase in the popularity of this sensor type. Like CCD arrays, CMOS sensors are also formed on a silicon substrate but the structure is more akin to that of other CMOS technology such as RAM and ROM memory devices.

The diagram below is that of an actual CMOS sensor showing the active pixel area in green and the area occupied by the on chip circuitry in yellow, which replaces that of the shuttered area on a CCD based sensor. The on chip circuitry actually converts the charge into voltage on each pixel whereas the CCD sensor shifts the charge vertically row by row, and then horizontally pixel by pixel to be converted to voltage when it reaches one or more output nodes. This gives CMOS sensors an advantage when it comes to windowing or a region of interest as the pixels can be read out randomly. CCD sensors can only limit its region of interest vertically with the resulting image always containing the data for the full image width.

The on chip active amplifier and the sampling capacitor give CMOS sensors advantages in terms of speed, full well capacities and much improved response characteristics yet introduce dark current level noise and higher black pixel content. CMOS sensors can also produce higher levels of fixed pattern noise than that of CCD, but this type of noise can be easily removed with a software filter.

The development of CMOS sensor technology has been a rapid and varied process. The initial aim of CMOS sensors was to match the imaging performance of CCD technology, with lower power requirements and at less cost. To achieve this performance it was discovered that a much greater level of manufacturing process adaptation and deeper submicron lithography were required than initially expected. This led to the desired CMOS performance but increased development costs more than anticipated.

At first the low power feature of the CMOS imaging sensors was set to be one of their distinct advantages, however the improved development of CCD sensors means that while CMOS has the advantage in this area, the margin is now much smaller.

The integration of on chip control circuitry with the CMOS imager provides the sensor with greater flexibility and integration, the downside has been the introduction of greater noise levels. Both CMOS and CCD imaging sensors still require support chips to process the image, however CMOS imagers can be produced with more functionality on the sensor chip, as shown below.

The spectral response of a CMOS sensor differs from that of the CCD sensors in that the peak response is sited at around 700Nm. Both sensors operate over the same range, typically 200Nm to 1100Nm.

The main advantages of CMOS imaging sensors still remain as faster response, increased integration flexibility and lower on-chip power demands. However the image quality has yet to match that of the CCD and the supporting chips required to increase the CMOS image quality goes some way to squander its previous advantages. Yet neither sensor is categorically superior to the other. They both have their own advantages and disadvantages and with CMOS developers working on the image quality, and CCD developers aiming to reduce power demands and increase flexibility, the existing margins in place to decide which sensor is most suitable for an application look to narrow further.

Electronic Guardian Angel That Spots The Bad Guys And Respects Your Privacy

Electronic Guardian Angel That Spots The Bad Guys And Respects Your Privacy

New computerized surveillance cameras detect & confirm threats from one meter to one mile

A former BT communications manager, turned inventor, reckons that his intelligent CCTV surveillance company has developed a “Guardian Angel” video surveillance technology, which can keep us all safe from crime and violence whilst protecting our Right to Privacy. Stuart Thompson was a recognized innovator with British Telecom, where he led in the development of the high speed modems that introduced broadband internet. He has now used his high-speed expertise and ingenuity to develop an award-winning intelligent moving camera system that will passively observe and ignore innocent goings-on, but quickly alert human operators to suspicious or dangerous activity. In addition to crime-busting on Britain's streets, Stuart Thompson claims the system can significantly enhance Homeland Security whilst unobtrusively safeguarding our schools or our elderly and vulnerable citizens in care homes and hospitals.

Thompson is President and owner of Viseum UK. He reminds us how the Director General of MI5 recently warned that thousands of Islamic extremists living in the UK, currently saw their British home as a legitimate target. He adds that the UK Home Office also admitted the E-Borders programme had failed to detect and intercept major crime suspects at our national borders. Elsewhere at another end of the spectrum, the CQC recently recommended surveillance camera installation in care homes to protect vulnerable adults from abuse by a few reckless and abusive members of staff. In a busy, populated area, these all represent significant albeit very different security challenges that have dogged ordinary CCTV providers and the security industry for decade. As Stuart Thompson puts it;

“Discerning suspicious and potentially harmful indicators within a sea of mundane, innocent routine is a needle-in-the-haystack task, that human beings are exceptionally bad at.”

However the London inventor, claims he has the solution in a computer-automated CCTV system, optimised for the complex and busy environments that we live and work in. Viseum UK’s globally patented Intelligent Moving Camera (IMC) is controlled by iVOS (an Intelligent Virtual Operator system). Viseum intelligent CCTV systems can recognize and track suspicious activity and a known hooligan, criminal or terrorist, with far greater reliability than any human CCTV operator. The system uses a ring of automated surveillance cameras to passively gaze in every direction and be aware of all activity around them. The system quickly learns its surroundings and “normal” activity. However, Thompson points out that footage of routine events largely stays within the camera unit – unseen by a human. Only when the iVOS Virtual Operator detects unusual or potentially suspicious and dangerous activity, will a human operator in a central control room, be alerted. The security operator will be shown edited footage of what the Viseum system spotted. He can then alert the authorities, emergency services or security patrols and guide them onto the scene. In the meantime, the Intelligent Moving Camera system has automatically fired into evidence collection mode. It takes control of a high clarity pan, tilt zoon camera to capture forensic quality images of what is going on and who is involved. Thompson explains that his Find, Fix, Follow (F3) capability uses behaviour algorithms, plus face, person and vehicle number plate recognition technology to track a suspect or perpetrator wherever they go within the streets, buildings and corridors covered by the Viseum camera network. Viseum iVOS is just as adept at spotting a suspiciously abandoned holdall, agitated behaviour, a neglected patient, or a harassed lone female late at night. However, should there be nothing untoward going on, then the images stay within the system’s hard-drive to be recorded over at a specified point. “I designed the IMC and iVOS systems to be virtual guardian angels, benignly gazing upon our daily lives, but ready to intervene should we be threatened,” 

Depending on the camera hardware used, each of these Viseum camera units delivers surveillance security from close quarters in a bedroom, through an airport and up to an area the size of an Olympic Park. Viseum's technology is well known to several police forces and borough councils, for the positive impact they have had upon crime and anti-social behaviour in the UK's public spaces. Conviction statistics show that criminals and ASBO offenders have good reason to fear them. Optimised for busy streets and crowded cities, with 360-degree coverage up to extreme distances, the Intelligent Moving Camera never blinks, never gets tired, looks in the wrong direction or gets distracted.

Viseum emphasises that it aims to optimise and supplement the human response to security incidents, rather than replace them completely. Viseum’s military force-protection & security experts, term this as "force-multiplication" freeing up people to do what they do best - interact with other people. Thompson explains, "Our surveillance solutions are the best. We offer security practitioners a continuous 360 degree unblinking stare across any area of responsibility, without the need for hundreds of CCTV cameras and valuable monitoring staff. It will also provide instantaneous forensic analysis of a previously unknown perpetrator's movements before and after the event. We can present patrols, incident commanders and the judiciary with an unbroken golden thread of video evidence, about what happened and who was involved. Viseum adds, "Viseum iVOS can also contribute to and enhance wider security at hospitals and care homes where intruders may attempt access or confused patients might wander off”.

Viseum has recently visited the USA to take part in a technology showcase at “Government Security Expo” in Dallas Texas. It was striking though not surprising that we share so many security challenges with the States,” said Thompson. “Local police chiefs, military base commanders, university campus supervisors, care home providers and Homeland Security practitioners all shared a fear of the low probability but high impact event that could occur within their area of responsibility. To use military parlance, they want perfect “Situational Awareness and Ground Truth” before, during and after an incident. We think that Viseum can deliver this for them and are actively involved in talks to secure an American partner to introduce our technology in this region.

For more information on the Viseum intelligent surveillance systems please visit http://www.viseum.co.uk
For further information on this release and other Viseum news and products, please contact Media contact Ian Cumming Director Business Development & Communication
via: t: +44 (0)1322 405724
e: press.office@viseum.co.uk

MS SQL SERVER VS ORACLE 10G COMPARE

COMPARE MS SQL SERVER VS ORACLE 10G

SQL Server:

Pros:

Its easy installation, self-tuning capabilities, graphical administration, integrated business intelligence and extensive collection of help wizards

The total cost of ownership (TCO) of SQL Server 2005 is lower than that of Oracle

Specialized index on a computed column

Indexed View

Cons:

Locking and concurrency: SQL Server has no multi-version consistency model, which means that "writers block readers and readers block writers" to ensure data integrity

Performance and tuning:

a. DBA has no "real" control over sorting and cache memory allocation. The memory allocation is decided only globally in the server properties memory folder, and that applies for ALL memory and not CACHING, SORTING, etc.

b. All pages (blocks) are always 8k and all extents are always 8 pages (64k). This means you have no way to specify larger extents to ensure contiguous space for large objects.

c. In SQL Server, no range partitioning of large tables and indexes. In Oracle, a large 100 GB table can be seamlessly partitioned at the database level into range partitions.

With SQL Server 2005, INSERT, UPDATE, and DELETE statements are executed serially (MERGE is not supported).

Oracle:

Pros :

you can use Oracle on multiple platforms. Whereas Microsoft created SQL Server to be used on the Microsoft platform only, Oracle is available on multiple platforms, including Windows, Unix and now Linux, which is the foundation of Oracle's Real Application Clusters (RAC) strategy.

Locking and concurrency: "readers don't block writers and writers don't block readers." This is possible without compromising data integrity because Oracle will dynamically re-create a read-consistent image for a reader of any requested data that has been changed but not yet committed. In other words, the reader will see the data as it was before the writer began changing it (until the writer commits).

function-based indexes

Oracle will execute INSERT, UPDATE, DELETE, and MERGE statements in parallel when accessing both partitioned and non-partitioned database objects

Cons:

"Implementation of something similar to MSSQL Identity by using Oracle sequence would require reflecting the sequence name in the application or creating a trigger for each table/sequence pair.

Cost is higher

Required skilled DBA.

CONCURRENCY MODEL

concurrency control. The main differences are summarized in the table below:

Oracle Database 10g SQL Server 2005

Multi-version read consistency Always enabled. Not by default.

Must be enabled.

Non-escalating row-level locking Yes Locks escalate

SQL Server 2005 introduces two new isolation levels3:

read committed with snapshots (statement-level read consistency)

snapshot isolation (transaction-level read consistency)

These isolation levels correspond to Oracle’s READ COMMITTED and SERIALIZABLE isolation levels, respectively.

CCD Sensor Operation in Camera

This diagram illustrates the general layout of the most common type of CCD array, the Interline Transfer CCD. The CCD is composed of precisely positioned light sensitive semiconductor elements arranged as rows and columns. Each row in the array represents a single line in the resulting image. When light falls onto the sensor elements, photons are converted to electrons, the charge accumulated by each element being proportional to the light intensity and exposure time. This is known as the integration phase. After a pre determined period of time the accumulated charge is transferred to the vertical shift registers.

In cameras conforming to the video standards mentioned above the charge transfer to the vertical shift registers is accomplished in two stages. Initially the charge in the odd numbered rows is transferred, followed by the even rows. Next the charges in the vertical registers are shifted into the horizontal shift register and clocked to the CCD output. Consequently all the odd rows are clocked out first (odd field) followed by all the even rows (even field). The rate at which the charge from the horizontal shift registers is clocked out is governed by the number of elements (pixels) per row and the video standard the camera complies with.

An inherent problem associated with the interline transfer CCD lies in the fact that the vertical shift registers running across the array are insensitive areas and as such act as blind spots. One way of overcoming this is to fabricate micro lenses over each element thereby increasing the effective area of the cell. The lenses also help with the smaller format CCD. Because of the electrical characteristics of the semiconductor substrate on which the CCD is formed each cell has an absolute minimum separation from adjacent cells. Therefore smaller CCDs require smaller cells. Reducing cell size reduces the amount of accumulated charge, using lenses increases the incident light.

Another way of overcoming the problem caused by the vertical shift registers is to do away with them and utilize a different charge transfer mechanism. Frame Transfer CCDs do exactly that. This type of CCD has a separate storage area into which the charge is directly transferred from each cell. This process has to be performed rapidly in order prevent blurring as transfer occurs during the exposure time. Once in the storage area the charge can be clocked out in a similar manner to the interline transfer device.

Splice the Wires for a Security Camera

Splice the Wires for a Security Camera

Security cameras need two types of cables to operate.

1.       Power supply cable and

2.       Video cable.

Wireless security cameras do not require a video cable but they do require the power supply cable. The power cable transports 12V DC, low-voltage power from the transformer, which is plugged into an 220VAC ~ 110VAC power outlet, to the camera. This cable has two 18 gauge wires, a positive wire and a negative wire, both inside a single jacket. The negative wire will be marked with a black or white stripe. The video cable is a RG-59 / RG6 / RG11: coaxial cable which is shielded and requires BNC connectors to protect the integrity of the video signal being carried.

For Power Supply Cable:

Instructions 1

Use your knife or cable cutters to split the two insulated wires apart approximately three inches from the cut end of the cable, leaving the installation intact on both wires. You can usually pull these apart with your hands. Do this on both ends which you intend to splice together. You should now have two power cables, with two insulated wires coming out of each for a total of four wires to be spliced.

Instructions 2

Remove half an inch of the insulation from the end of each of these four wires.

Instructions 3

Splice these two power cables together, using wire nuts, by twisting the exposed copper ends together making sure that you twist positive from one cable to the positive from the other cable and the negative wire, or striped wire, from one cable to the negative wire, or striped wire, from the other cable. Screw a wire nut on to the joined or twisted together positive wires and a second wire nut on the twisted together negative wires. Lay the wire nuts against the cable and wrap everything with insulated electricians tape.

Instructions 4

Splice these two power cables together, using Butt connectors, by preparing the cables just like you did for the wire nut splice, only without twisting them together. Insert the exposed copper wire from the positive conductor into one end of the butt connector and crimp that end of the connector down. Insert the other positive wire into the other end of the same butt connector and crimp it down. Do the same for the two negative wires using a second Butt connector. Wrap everything with insulated electricians tape.

For Video Cable:

Instructions  5

Look at the cut end of the RG-59 cable and you will see four separate parts which make up this cable. In the center is the copper center conductor wire. Surrounding the center conductor wire is a polyurethane white insulator. Next is the aluminum or copper braid. And finally, there is the outer jacket of the cable. As you prepare this cable for the BNC connector is important that you prepare each of these four separate parts independently of each other. The copper center conductor must remain untouched by the braid.

Instructions 6

Take the BNC crimping tube and hold it alongside the end of the RG 59 cable to measure your first cut. The crimping tube will have a larger diameter part and a smaller diameter part. The larger diameter part is the end of the crimping tube that you want to match against the end of the RG-59 cable.

Instructions 7

Mark, or just eyeball, the outer jacket on the cable where the large part of the crimping tube ends and the smaller part begins. This will be about 3/8 or 1/2 inch from the end of the cable. This measurement depends on the length of the large part of the crimping tube which you have purchased with the BNC connector.

Instructions 8

Cut and remove the outer jacket only by ringing it with a pocket knife or using cable cutters. Be very careful not to damage the aluminum braid which is right underneath the outer jacket.

Instructions 9

Unravel the exposed aluminum braid so you can pull it away from the polyurethane insulation around the copper center conductor.

Instructions 10

Cut and remove the polyurethane insulation from the copper center conductor. You can ring it with a knife or use cable cutters and it should pull free towards the cut end of the center conductor. The cable is now ready for the connector and the cable should now have only the copper center conductor exposed and the aluminum braid pulled back over the outer jacket.

Instructions 11

Slide the crimp tube over the cable with the small end going on the cable first. Before you can slide the crimp tube on you must pull the aluminum braid towards the cut end of the cable so the crimp tube can go around it and slide directly onto the outer jacket of the cable.

Instructions 12

Slide the BNC connector into place, small end first, with the copper center conductor and the polyurethane insulation going inside of the small part of the connector and the aluminum braid and outer jacket staying on the outside of the small part of the connector. As you push the connector down into the cable it will pull the aluminum braid down inside the outer jacket at the same time. Looking inside the connector and make sure that none of the aluminum braid has inadvertently remained inside the connector and possibly touching the center conductor. If the aluminum braid is touching the center conductor the connection will not work.

Instructions 13

Slide the crimping tube back up the outer jacket until it is touching the BNC connector. Use your crimping tool to now crimp the larger portion of the crimping tube and complete the compression placement of the BNC connector.

Instructions 14

Repeat this process, placing the second BNC connector on the second piece of cable. When you have completed this you should have two pieces of video cable with a BNC connector on each piece. Use the BNC barrel connector to connect these BNC connectors together. The video cable splice is now complete.

Cable Fault Location Principle and Instrument

Wire and cable fault location equipment has rised as a result of cable applications, using the progress and development of electronic technology, after having a century of changes, the key still but looks Nisshin. As a result of few cable systems failure, positioning experience accumulate very slow. Using the use of automation, technology, the instrument has made substantial progress. Power Cable Fault Locator is utilized to do this work. There are four steps of cable fault location process.

 

(1)CABLE FAULT TYPE JUDGMENT

Should first serious take a look at the failure of cable throughout, fully understand the faulty cable, and detailed records, which will help find fault faster. Positioning method and sort of cable fault. Judgment cable fault type enables you to measure the insulation resistance or DC voltage test. Shaking table or digital megger relative measurement fault cable and white, and metal outer sheath-ground insulation resistance value. Point of failure the measured worth of the insulation resistance measuring voltage, the condition of the environment, sometimes values ??vary greatly. At different voltages, to see the changes over time, the insulation resistance of the fault point, combined with the characteristics from the cable and laying path, so that you can interpret many of information, as an example, the sort of failure as well as the possible positions.

(2)FAULT PRETARGETING

Bridge method and wave reflection way of the the pretargeting two main means. The proportion of resistance on the point of failure on sides of the cable core resistance and instrument constitutes the Murray Bridge, can be a traditional classic cable fault location. Positioning the bridge equipment low cost, simple operation, and had widespread use. Traditional positioning from the bridge, the rated output voltage only 500V, unable to locate high impedance fault. The big quantity of applications, cross-linked polyethylene cable breakdown is difficult to form the conductive zone breakdown point resistance is high, or even have the ability to withstand our prime voltage was flashover type breakdown. Using the positioning of the popularity of wave reflection method, the method of application of the bridge gradually reduce, not known towards the new cable users.

(3)PATH DETECTION

The precise positioning ahead of the point of failure, you need to know the position and direction of the underground cable, the relevant details are often inaccurate, not even. With a dedicated path analyzer measured to find the position and direction of the underground cable. Path analyzer uses the audio induction method to appraise the cable path. The audio generator for the the measured cable input audio signal current on the headend, the receiver is received on a lawn fault cable generates a magnetic signal to its path and depth measurement.

(4)ACCURATELY FIXED

Depending about the kind of fault, there are various ways and instruments for pinpointing. Cable Fault Locator is a necessity. Fault Location in Power Cable is designed to locate cable faults, pinpointing the fault location, route tracing, cable identification, voltage withstand make sure cable information management. It could locate all kinds of cable faults for many voltage level cables, including open circuit, short circuit, low insulation, high insulation and flashover faults, etc. Most power cables were buried underground, invisible, and unrealistic, with modern new power cable fault testing equipment, it may discover the fault point quickly, solve problems immediately and restore power source.