Word of the Day : The KnujOn Antispam Project

The KnujOn Project is an interactive Web-based spam reporting service. By working with the Internet community at large and focusing on shutting down the distribution points for spam, the KnujOn Project hopes to cut off spam at its source. Bob Bruen, Knujon's creator and developer, named the service to reflect its function: "KnujOn" is "no junk" spelled backwards.

Knujon works by gathering and analyzing spam to determine its origin and points of distribution. The service solicits examples of spam from the public, providing individual users and business networks with software that reports incoming spam automatically. KnujOn runs the spam it receives through a process it calls the Policy Enforcement Engine. The Policy Enforcement Engine examines each instance of spam, filters by sending URL to determine origin, and analyzes the message to determine the best course of action. In some cases, KnujOn coordinates with ISPs (Internet service providers) to shut down offending Web servers. By eliminating these transaction platforms and (sometimes) initiating legal action, KnujOn increases operational costs for spammers and lowers the value of unsolicited bulk email (UBE). This approach contrasts with that of spamhaus, which typically identifies spammers but does not directly address the means of distribution or ISPs.

In the future, KnujOn plans to include banks, and consumer product companies in the service. Typically, KnujOn receives about 20,000 pieces of junk mail a day from more than 2,000 registered subscribers and about the same number of unregistered members. Registration costs $27 annually. Since its founding in 2005, KnujOn's efforts have led to the shutdown of tens of thousands of sites, including those trafficking in the following:

• Counterfeit or unlicensed prescription drug sales on the Internet
• Traffic in knockoff, diverted, pirated, and stolen merchandise
• Predatory lending in the sub-prime and refinance mortgage industry
• Vacation scams
• Identity theft

In addition to developing technical tools to address spam, research at KnujOn explores the issues that drive its creation, studying the impact on individual victims as well as the burden on the economy. The challenge that KnujOn and other anti-spam software makers face is simple: Spam works. Currently more than 90% of all global email traffic is spam, with employees in the U.S. spending about 100 hours each year dealing with spam, for a daily loss of $130 million. The loss of productivity to companies is estimated at $712 per employee, or $71 billion annually to all U.S. businesses.

The chances of getting caught, prosecuted and punished are miniscule in comparison to the potential wealth. According to a Consumer Reports survey, 650,000 people purchased at least one item sold through a spam advertisement in a single month. If the average spam "unit" is $75, that is $48,750,000 per month or $585,000,000 per year. While the majority of Internet users may be blocking and deleting spam, the remainder keep the spammers employed.

Word of the Day : Fuzz testing

Fuzz testing or fuzzing is a software testing technique used to discover coding errors and security loopholes in software, operating systems or networks by inputting massive amounts of random data, called fuzz, to the system in an attempt to make it crash. If a vulnerability is found, a tool called a fuzz tester (or fuzzer), indicates potential causes. Fuzz testing was originally developed by Barton Miller at the University of Wisconsin in 1989.

Fuzzers work best for problems that can cause a program to crash, such as buffer overflow, cross-site scripting, denial of service attacks, format bugs and SQL injection. These schemes are often used by malicious hackers intent on wreaking the greatest possible amount of havoc in the least possible time. Fuzz testing is less effective for dealing with security threats that do not cause program crashes, such as spyware, some viruses, worms, Trojans and keyloggers.

Fuzz testing is simple and offers a high benefit-to-cost ratio. Fuzz testing can often reveal defects that are overlooked when software is written and debugged. Nevertheless, fuzz testing usually finds only the most serious faults. Fuzz testing alone cannot provide a complete picture of the overall security, quality or effectiveness of a program in a particular situation or application. Fuzzers are most effective when used in conjunction with extensive black box testing, beta testing and other proven debugging methods.

Word of the Day : Windows SharePoint Server

Windows SharePoint Server (WSS), usually referred to as simply "Sharepoint," is a portal-based platform for creating, managing and sharing documents and customized Web services. WSS is available as a free download included with every Windows Server license. Microsoft Office SharePoint Server (MOSS) offers an increased set of capabilites that add to and build upon the core functionalities of WSS as an inducement for system administrators to upgrade.

Sharepoint was originally added on to Windows Server at the same time as Office XP under the title "SharePoint Team Services" or STS. STS was available as part of Microsoft FrontPage and could run on Windows 2000 Server or Windows XP. The 2.0 version advanced the functionality of the platform by storing both documents and meta data in a database and adding support for versioning for items held in document libraries, SQL Server and the .NET framework. This version of the software was downloaded and implemented at a rate unanticipated by Microsoft, as administrators adopted the platform as a relatively cheap and easy way to introduce collaborative document sharing and editing in Windows environments. Microsoft noted this use and embraced Sharepoint as the cornerstone of a strategy to embrace social computing, bringing Web 2.0 technologies like blogs, wikis and social networking into enterprises without some of the security risks of Internet-based software as a service (SaaS) implementations.

Microsoft's Sharepoint competes against IBM's Notes and Quickr, Oracle's WebCenter Suite, Google Docs and CMS software from EMC, Adobe, Cisco and smaller startups like Socialtext and Zimbra. Many organizations are also exploring free, open source wiki software like MediaWiki, the application that underlies Wikipedia.

Critics of Sharepoint point out that certain features of Sharepoint Server 2007 will only work with the newest version of Microsoft Office, thereby forcing IT managers to upgrade their software. Sharepoint's lack of support for non-Microsoft formats, like files saved using Quark or Adobe Acrobat (.PDF), is a cause of concern for some administrators evaluating the suite as a potential enterprise-wide CMS. Microsoft has also been careful to avoid the bundling charges the company faced in the browser wars of the 1990s, separating WSS as a free download instead of including it with Windows Server.

Word of the Day : Hardware as a Service (HaaS)

Hardware as a Service (HaaS), in a grid computing context, is a pay-as-you-go model for accessing a provider's infrastructure and CPU power. Grid computing is a technology in which several computers work together to act as a single, more powerful computer. Some companies sell use of their grids over the Internet on a per-use basis. The user sends data and a program to process that data; the vendor's grid does the processing and returns the result.

Word of the Day : Hardware virtualization

Hardware virtualization is when the virtual machine manager is embedded in the circuits of a hardware component instead of being called up from a third-party software application. The virtual machine manager is called a hypervisor.

The job of the hypervisor is to control processor, memory and other firmware resources. The hypervisor acts like a traffic cop, allowing multiple operating systems to run on the same device without requiring source code or binary changes. Each operating system appears to have the processor, memory, and other firmware resources all to itself -- but in reality, the hypervisor is controlling the processor and its resources, allocating what is needed to each operating system in turn.

Hardware virtualization is an evolving technology that may become dominant, especially for server platforms, because it has the potential to facilitate the consolidation of multiple workloads on a single physical server without requiring third-party software.

Word of the Day : Fibre Channel over Ethernet

Fibre Channel over Ethernet
FCoE (Fibre Channel over Ethernet) is a proposed standard designed to enable Fibre Channel communications to run directly over Ethernet. FCoE makes it possible to move Fibre Channel traffic across existing high-speed Ethernet infrastructures and extend the reach and capability of storage area networks (SANs). This ability allows organizations to protect and extend existing investments in their storage networks.

Word of the Day : Femtocell

A femtocell is a wireless access point that improves cellular reception inside a home or office building.

The device, which resembles a wireless router, essentially acts as a VoIP repeater. When connected to Internet broadband, it broadcasts the connection using radio waves.

A cell phone call initiated in a home equipped with femtocall would start at the handset, be sent to the femtocell, go from the femtocell to the Internet through the broadband connection, and end up back on the cellular network.

Femtocells are compatible with CDMA2000, WiMAX, or UMTS mobile telephony devices, using the provider's own licensed spectrum to operate. One femtocell can potentially service up to five mobile devices concurrently.

Femtocells were originally called access point base stations. The term was derived from cell and "femto," a metric prefix that stands for 10^-15th, or one-quadrillionth, six orders of magnitude smaller than nano. The development of femtocells is credited, in part, to the work of a skunkworks team at Motorola in the UK, where they created the world's smallest full power UMTS base station.

Femtocell technology is still in its infancy, in terms of actual installations. Service providers are promoting the technology as a cost-effective way for customers to extend indoor coverage.

Word of the Day : Microsoft Office SharePoint Server

Microsoft Office SharePoint Server (MOSS) is the full version of a portal-based platform for collaboratively creating, managing and sharing documents and Web services. MOSS enables users to create "Sharepoint Portals" that include shared workspaces, applications, blogs, wikis and other documents accessible through a Web browser. The free version, Windows SharePoint Server (WSS), usually referred to as simply "Sharepoint," is available as a free download included with every Windows Server license.

MOSS is used by many enterprises as a content management system (CMS). Partially as a result of the tight integration with Microsoft productivity applications included in Office, such as Word, many administrators have found MOSS useful in organizing and aggregating an enterprise's data into Web-based portal with defined taxonomies that structure the information. MOSS includes additional features as an inducement for system administrators to upgrade from WSS, including knowledge management, organization of business processes and enterprise search. Both versions include support for many Web 2.0 technologies and third-party Web browsers like Firefox.

Fundamentally, MOSS provides an integrated platform for building customized Web-based applications and portals in Windows Server environments. To address the needs of remote workers and telecommuters, as well as system administrator concerns for data security, MOSS can be configured to return separate content depending on whether access is gained from intranet, extranet or Internet locations. Active Directory groups or HTML forms authentication can also be added to MOSS, granting multiple permissions to multiple parties or through alternate providers.

Users log on to Web portals to edit and create shared documents. These "SharePoint portals" are ASP.NET applications that are hosted on a server and use a SQL Server database. MOSS provides Web browser-based management and administration tools that allow users to create and edit a document or document library independently. Collaborative editing of this kind is aided by integrated access and revision controls, allowing administrators to freeze certain documents or restrict user privileges where required. MOSS also uses embeddable widgets in shared Web pages to add additional functionality. Widgets include:

• shared workspaces and personal dashboards
• navigation tools
• lists
• automatic alerts, including email and integrated RSS
• shared calendar and contacts
• discussion boards

Users build SharePoint pages is by combining selected widgets into a Web page. Any Web editor that supports ASP.NET can be used for this purpose, though Microsoft has released a WYSIWYG HTML editor, Microsoft Office SharePoint Designer (MOSD), that was specifically designed for this purpose.

Critics of SharePoint point out that certain features of MOSS 2007 only work with the newest version of Microsoft Office, thereby forcing IT managers to upgrade their software. SharePoint's lack of support for non-Microsoft formats, like files saved using quark or Adobe Acrobat (.PDF), is also a cause of concern for some administrators evaluating the suite as a potential enterprise-wide CMS.

The previous versions of SharePoint are SharePoint Portal Server 2003 and SharePoint Portal Server 2001.

Word of the Day : Google Docs

Google Docs is a free Web-based application in which documents and spreadsheets can be created, edited and stored online. Files can be accessed from any computer with an Internet connection and a full-featured Web browser. Google Docs is a part of a comprehensive package of online applications offered by and associated with Google.

Users of Google Docs can import, create, edit and update documents and spreadsheets in various fonts and file formats, combining text with formulas, lists, tables and images. Google Docs is compatible with most presentation software and word processors. Work can be published as a Web page or as a print-ready manuscript. Users can control who sees their work. Google Docs is ideal for publishing within an enterprise, maintaining blogs or composing work for viewing by the general public.

Google Docs lends itself to collaborative projects in which multiple authors work together in real time from geographically diverse locations. All participants can see who made specific document changes and when those alterations were done. Because documents are stored online and can also be stored on users' computers, there is no risk of total data loss as a result of a localized catastrophe. However, the Internet-based nature of Google Docs has given rise to concerns among some authors that their work may not be private or secure.

Word of the Day : Bit Stuffing

bit stuffing

Bit stuffing is the insertion of one or more bits into a transmission unit as a way to provide signaling information to a receiver. The receiver knows how to detect and remove or disregard the stuffed bits.

For example, the timing or bit rate of T-carrier system signals is constantly synchronized between any terminal device and an adjacent repeater or between any two repeaters. The synchronization is achieved by detecting the transition in polarity for 1 bits in the data stream. (T-1 signalling uses bipolar signaling, where each successive bit with a value of 1 is represented by voltage with a reverse polarity from the previous bit. Bits with a value of 0 are represented by a no-voltage time slot.) If more than 15 bits in a row are sent with a 0 value, this "lull" in 1 bits that the system depends on for synchronization may be long enough for two end points to become out of synchronization. To handle this situation (the sequence of more than 15 0 bits), the signal is "stuffed" with a short, unique bit pattern (which includes some 1 bits) that is recognized as a synchronization pattern. The receiving end removes the stuffed bits and restores the bit stream to its original sequence.

In another example of bit stuffing, a standard HDLC packet begins and ends with 01111110. To make sure this sequence doesn't appear again before the end of the packet, a 0 is inserted after every five consecutive 1s.

Bit stuffing is defined by some to include bit padding, which is the addition of bits to a tranmission to make the transmission unit conform to a standard size, but is distinct from bit robbing, a type of in-band signaling.

Word of the Day : WYSIWYP

WYSIWYP (what you see is what you print)

WYSIWYP (what you see is what you print) is the ability of an application program, such as a word processor, to generate print versions of content that match what the user sees on the screen. The WYSIWYP feature is intended to resolve a problem that has plagued users of word processors ever since computers replaced typewriters: printouts often differ from their on-screen counterparts.

A printout from a program with WYSIWYP should have the same layout, resolution and colors as the onscreen version. However, the success of WYSIWYP may depend, to some extent, on user hardware and associated software.

The term is a variation on WYSIWYG (what you see is what you get) and is pronounced similarly: "whizzy-whip."

Word of the Day : WS-Transaction (WS-TX)

WS-Transaction (WS-TX)

WSTx (Web Services Transaction) is a set of XML markup specifications designed to permit the use of open, standard protocols for secure, reliable transactions across the Web. Three constituent standards were approved in April 2007:

• WS-Coordination
• WS-AtomicTransaction
• WS-BusinessActivity

The standards were created to accommodate two typical transaction patterns involving multiple, distributed software components and services:

1. Individual atomic transactions that represent the building blocks for more complex transactions among peers and partners

2. Web-based interactions that result in the exchange of goods, information, or services, usually called business activities.

WS-coordination refers to the mechanisms whereby atomic transactions may be composed into complete business activities, and thus also provides the glue that ties the overall WSTx environment together.

WSTx standards are overseen by a technical committee of the same name at OASIS. The technical committee is staffed with vendors and users of Web services technologies. On its Web pages, the committee describes its agenda as: "...to define a set of protocols to coordinate the outcomes of distributed application actions." Vendors involved in the WSTx committee include Adobe, BEA Systems, Fujitsu, Hitachi, IBM, Microsoft, Oracle, SAP and TIBCO, among numerous others.

Word of the Day : Electromagnetic fields

An electromagnetic field, sometimes referred to as an EM field, is generated when charged particles, such as electrons, are accelerated. All electrically charged particles are surrounded by electric fields. Charged particles in motion produce magnetic fields. When the velocity of a charged particle changes, an EM field is produced.

Electromagnetic fields were first discovered in the 19th century, when physicists noticed that electric arcs (sparks) could be reproduced at a distance, with no connecting wires in between. This led scientists to believe that it was possible to communicate over long distances without wires. The first radio transmitters made use of electric arcs. These "spark transmitters" and the associated receivers were as exciting to people in the early 20th century as the Internet is today. This was the beginning of what we now call wirelesscommunication.

Electromagnetic fields are typically generated by alternating current (AC) in electrical conductors. The frequencyof the AC can range from one cycle in thousands of years (at the low extreme) to trillions or quadrillions of cycles per second( at the high extreme). The standard unit of EM frequency is the hertz, abbreviated Hz.Larger units are often used. A frequency of 1,000 Hz is onekilohertz(kHz); a frequency of 1,000 kHz is one megahertz (MHz); a frequency of 1,000 MHz is one gigahertz (GHz).

The wavelength of an EM field is related to the frequency. If the frequency f of an EM wave is specified in megahertz and the wavelength w is specified in meters (m), then in free space, the two are related according to the formula:

w = 300/f

For example, a signal at 100 MHz (in the middle of the American FM broadcast band) has a wavelength of 3 m, or about 10 feet. This same formula applies if the frequency misgiven in gigahertz and the wavelength is specified in millimeters (mm). Thus, a signal at 30 GHz would have a wavelength of 10 mm, or a little less than half an inch.

The realm of EM field energy is called the electromagnetic radiation spectrum. In theory, this extends from arbitrarily long wavelengths to arbitrarily short wavelengths, or, as engineers sometimes imprecisely quip, "from DC to light."

Word of the Day : Dogfood

Dogfood is an expression that means "to use the product or service that you are trying to sell."

Dogfood can be used as a noun, as in the sentence "A company that eats its own dog food sends the message that it considers its own products to be the best on the market." Or it can be used as a verb, as in the sentence "We need to dogfood this product before we roll it out to the public."

The expression was inspired by an advertising campaign for commercial dog food from the 1970's where actor Lorne Greene told consumers "And when it comes to feeding my own dog, I know there isn't a better dog food than Alpo." The message to the consumer was that the product spokesman thought Alpo was so good that he used it himself.

According to Paul Vick, Microsoft's tech lead for Visual Basic Development, dogfood is part of the company culture at Microsoft because:

1) It proves to customers that Microsoft believes in their products.
2) It helps flush out bugs, because dogfooding involves beta (or pre-beta) software.
3) It makes Microsoft employees suffer the same bugs and design flaws that they inflict on users, thereby providing incentive to fix them.
4) It's a valuable reality check that the product is actually as good as Microsoft says it is.
5) Because Microsoft is such a large company, dogfooding an enterprise-level product can flush out problems that could not otherwise be found prior to full-scale rollout at launch.
6) It allows Microsoft developers to learn how their products actually work, which may not be exactly how developers think they work.

Word of the Day : Deep packet inspection (DPI)

Deep packet inspection (DPI)

Deep packet inspection (DPI) is an advanced method of packet filtering that functions at the application layer of the OSI (Open Systems Interconnection) reference model. The use of DPI makes it possible to find, identify, classify, reroute or block packets with specific data or code payloads that conventional packet filtering, which examines only packet headers, cannot detect.

Using DPI, communications service providers can allocate available resources to streamline traffic flow. For example, a message tagged as high priority can be routed to its destination ahead of less important or low-priority messages or packets involved in casual Internet browsing. DPI can also be used for throttled data transfer to prevent P2P (peer-to-peer) abuse, improving network performance for most subscribers. The security implications of DPI are widespread because the technology makes it possible to identify the originator or recipient of content containing specific packets, a capability that has sparked concern among advocates of online privacy.

DPI has at least three significant limitations. First, it can create new vulnerabilities as well as protect against existing ones. While effective against buffer overflow attacks, denial of service attacks and certain types of malware, DPI can also be exploited to facilitate attacks in those same categories. Second, DPI adds to the complexity and unwieldy nature of existing firewalls and other security-related software. DPI requires its own periodic updates and revisions to remain optimally effective. Third, DPI can reduce computer speed because it increases the burden on the processor. Despite these limitations, many network administrators have embraced DPI technology in an attempt to cope with a perceived increase in the complexity and widespread nature of Internet-related perils.

Numerous companies, including such major players as Alcatel, Cisco, Ericsson, IBM, Microsoft, Nokia and Symantec have begun to aggressively market DPI technology as components of hardware and software firewalls.

Word of the Day : Fast Infoset (FI)

Fast Infoset (FI)

Fast Infoset (FI) is a standard that can serve as an alternative to XML (Extensible Markup Language) document formatting. The FI specification, which was approved by the ITU (International Telecommunication Union) in May 2005 and published in March 2007, is designed to provide more efficient serialization than XML.

Documents in XML format can be converted to FI format and vice-versa without loss of content. In a simplified sense, FI documents resemble compressed XML documents. However, Fast Infoset optimizes the speed with which ASN.1 binary encoding is generated and processed and minimizes the file size. The FI specification defines encoding for an XML infoset, a data model consisting of up to 11 components known as:

• Document information items
• Document type declaration information items
• Character information items
• Notation information items
• Namespace information items
• Element information items
• Attribute information items
• Processing instruction information items
• Unexpanded entity reference information items
• Comment information items
• Unparsed entity information items.

The FI specification is also known as ITU-T Rec. X.891 and ISO-IEC 24821-1.

Word of the Day : XML pipeline

XML pipeline

An XML pipeline is a formalized, logical expression of the method by which an XML (Extensible Markup Language) document is handled. An XML pipeline is rendered as a series of operations over an XML infoset, which is a collection of information items about the document's characters, attributes and namespaces, collectively called elements.

XML documents enter a pipeline and are processed by the operations. The documents are then output for display, storage or further processing. An XML pipeline can specify operations such as:

• Making a verbatim copy of a file
• Renaming a file
• Altering specific elements in a file.
• Resequencing the order in which elements in a file appear.
• Inserting new elements in a file.
• Deleting specific elements from a file.
• Surrounding (or wrapping) specific elements with additional elements.
• Splitting a file into multiple files.
• Merging (or aggregating) two or more files into a single file.

Word of the Day : Vouch by Reference (VBR)

Vouch by Reference (VBR)

Vouch by Reference (VBR) is an e-mail header tagging mechanism whereby senders can list third parties, known as domain certification services, that will attest to their integrity and good standing in the Internet community. When a sender includes a vouch-by-reference (VBR) list in an e-mail header, recipients (or intermediate servers) can look up VBR vouchers through the domain name service (DNS), to determine whether trusted third parties find the sender to be reputable. VBR makes it possible to bypass spam filtering, assuming that the recipient is willing to take the word of the voucher that the sender is legitimate.

Vouch by reference uses the domain name in the sender's e-mail address (the part that follows the "at symbol") to determine the sender's domain of origin. To avoid spoofing or prevent forgery, VBR relies upon sender authentication schemes such as DomainKeys Identified Mail (DKIM), the Sender Policy Framework (SPF) or Sender ID to prove that claimed identity and actual identity match.

Word of the Day : Open Grid Services Architecture

Open Grid Services Architecture

Open Grid Services Architecture (OGSA) is a set of standards defining the way in which information is shared among diverse components of large, heterogeneous grid systems. In this context, a grid system is a scalable wide area network (WAN) that supports resource sharing and distribution. OGSA is a trademark of the Open Grid Forum.

OGSA definitions and criteria apply to hardware, platforms and software in standards-based grid computing. The OGSA is, in effect, an extension and refinement of the service-oriented architecture (SOA). The OGSA addresses ongoing issues and challenges such as authentication, authorization, policy negotiation and enforcement, administration of service-level agreements, management of virtual organizations and customer data integration.

For a Web service to be considered a grid service, it must allow clients to easily discover, update, modify and delete information about the service's state, define how the service evolves and ensure ongoing compatibility with other services. The goal is to optimize communication and interoperability among resources of all types.

Word of the Day: JSON (Javascript Object Notation)

JSON (Javascript Object Notation)

JSON (Javascript Object Notation) is a text-based, human-readable data interchange format used for representing simple data structures and objects in Web browser-based code. JSON is also sometimes used in desktop and server-side programming environments. JSON was originally based on the JavaScript programming language and was introduced as the page scripting language for the Netscape Navigator Web browser.

JSON is used in Javascript on the Internet as an alternative to XML for organizing data. Like XML, JSON is language-independent and may be combined with C++, Java, Python, LISP and many other languages. Unlike XML, however, JSON is simply a way to represent data structures, as opposed to a full markup language. JSON documents are relatively lightweight and are rapidly executed on Web server.

JSON consists of "name : object" pairs and punctuation in the form of brackets, parentheses, semi-colons and colons. Each object is defined with an operator like "text :" or "image :" and then grouped with a value for that operator. As a result of this simple structure and absence of mathematical notation or algorithms, JSON is easy to understand and quickly mastered, even by users with limited formal programming experience, which has spurred adoption of the format as a quick, approachable way to create interactive pages.

Novice users of JSON need to be aware of potential security implications. As JSON scripts automatically execute in any Web page that's requested by a Web browser, they can be used to implement JavaScript insertion attacks against a Web client, like a command injection or cross-site scripting. For example, if a hacker inserts non-JSON code into the string, like a Trojan horse, the targeted algorithm executes the text in as if it were Javascript and then returns the value of the last statement. If the only statement was a JSON value, there's no effect. If a previous statement contains other Javascript code, however, that code will be executed by the script. The hacker might then have access to all the variables a script has access to, potentially compromising a user's PC.

Word of the Day: Electric Field Sensing

electric field sensing

Electric field (EF) sensing is a method of proximity sensing that allows robots and computers to detect, evaluate and work with objects in their vicinity. The technology is similar to that used in capacitive proximity sensing but incorporates refinements to analyze size, shape and contour.

In robot end effectors, EF sensing employs small, embedded metal electrodes connected to oscillators that produce high-frequency AC (alternating-current) electric fields. When anything that conducts electricity reasonably well, such as a person, animal, plant or metallic object, comes within a certain distance of the electrodes, the electric field fluctuates. The nature and extent of this change is sent to a microcomputer that compares the fluctuation pattern with stored patterns produced by known objects, allowing the end effector to easily grasp or manipulate the object.

The most sophisticated EF sensors can assemble detailed images. Using this technology in conjunction with other proximity-sensing methods such as machine vision, radar, sonar and fluxgate magnetometers, a mobile robot can intelligently navigate in its environment. EF sensors are less likely than optical sensors to be "fooled" by objects having unfamiliar textures. EF sensors do not detect non-conductive materials such as glass, dry wood or plastic. Non-conductive objects appear transparent or invisible to EF sensing devices, allowing the sensors to detect and analyze conducting objects through non-conducting barriers.

Word of the Day: Average Revenue Per User (ARPU)

average revenue per user (ARPU)

Average revenue per user or average revenue per unit (ARPU) is an expression of the income generated by a typical subscriber or device per unit time in a telecommunications network. The ARPU provides an indication of the effectiveness with which revenue-generating potential is exploited.

To calculate the ARPU, a standard time period must be defined. Most telecommunications carriers operate by the month. The total revenue generated by all units (paying subscribers or communications devices) during that period is determined. Then that figure is divided by the number of units. Because the number of units can vary from day to day, the average number of units must be calculated or estimated for a given month to obtain the most accurate possible ARPU figure for that month.

The ARPU can be broken down according to income-producing categories. For example, monthly or annual subscriber fees generate a steady revenue stream but do not take into account short-term changes in customer usage habits. The income generated by "excess minutes," roaming services or incoming calls can be highly variable. New, novel features may temporarily generate higher ARPU figures than established, proven functions. The ARPU can be calculated for each feature to identify sources of the greatest income per unit. The ARPU can also be calculated according to diverse factors such as geographic location, user age, user occupation, user income and the total time per month each user spends on the system.

The ARPU figure should not be confused with the average margin per user (AMPU), which is calculated on the basis of net profit rather than total income. In recent years, some telecommunications carriers have increased their reliance on AMPU rather than ARPU to maximize their returns as niche markets become saturated.

Word of the Day: SOA Networking

SOA networking

SOA networking is the use of the service-oriented architecture (SOA) model to enhance the capabilities of networks that use Web services. In SOA networking, events originating from diverse computers and communications devices are linked immediately and seamlessly to relevant business processes. The ultimate goal is the distribution of intelligence so the network functions as if it were a gigantic, self-contained computer.

One of the most important features of SOA networking is the consolidation of privacy and security services such as authentication, authorization, firewalls, anti-malware programs and encryption. Such consolidation reduces the complexity of network administration, minimizes the risk of vulnerabilities and lowers operational costs. It can allow for a more robust and reliable network than would otherwise be possible. SOA networking also facilitates streamlined testing for compliance with standards and regulations. Therefore, breaches become less likely and can be corrected in the shortest possible time when they do occur.

An SOA network functions in three layers:

• The application layer includes all the software used by businesses and subscribers.
• The interactive services layer ensures constant and reliable communication among all users, devices and applications.
• The systems layer maintains the physical integrity of the network and ensures hardware interconnectivity and compatibility.

Securing Home Wireless

Some quick tips on securing your home wireless network:

1. For a start, please change the default password.
   
2. Since it's your own home wireless and you should know the SSID, then go ahead and disable the broadcasting of SSID. For those model which do not have this feature, no fret, just continue on.
   
3. Now time to pick the encryption mode. Older generation of wireless box, or well at least for my SMC Barricade wireless router, may support only WEP mode - 64 bits and 128 bits. As of current, a lot more encryption mode are available such as WPA, WPA2, Tkip etc...Anyway, WPA should be more than sufficient, just make sure you pick a strong passphase.
4. For more advanced user, make use of MAC filtering for access control.
5. It's your home wireless, so there is no use for remote administration, just disable it.

Wireless Surveying - Search for a survey tool

I have done a number of wireless surveys mainly using one or more access points to determine real coverage and interference levels. Though on field results are of course more accurate, I'm still in search of tools that can over lay a building map are much more useful in planning a new wireless installation.