mekoblog

2008-05-19T22:30:00.000-07:00

Systems engineering

Systems engineering is an interdisciplinary field of engineering, that focuses on the development and organization of complex artificial systems. Systems engineering is defined by INCOSE as "a branch of engineering whose responsibility is creating and executing an interdisciplinary process to ensure that customer and stakeholder's needs are satisfied in a high quality, trustworthy, cost efficient and schedule compliant manner throughout a system's entire life cycle, from development to operation to disposal. This process is usually comprised of the following seven tasks: State the problem, Investigate alternatives, Model the system, Integrate, Launch the system, Assess performance, and Re-evaluate. The systems engineering process is not sequential: the tasks are performed in a parallel and iterative manner."

2008-05-12T23:00:00.000-07:00

Concurrent Versions System

In the field of software development, the Concurrent Versions System (CVS), also known as the Concurrent Versioning System, provides a version control system based on open-source code. Version control system software keeps track of all work and all changes in a set of files, and allows several developers (potentially widely separated in space and/or time) to collaborate. Dick Grune developed CVS in the 1980s. CVS has become popular in the open source software world and is released under the GNU General Public License.

2008-05-06T22:33:00.000-07:00

Solutrean hypothesis

The Solutrean hypothesis proposes that stone tool technology of the Solutrean culture in prehistoric Europe may have later influenced the development of the Clovis tool-making culture in the Americas, and that peoples from Europe may have been among the earliest settlers in the Americas. First proposed in 1998, its key proponents include Dennis Stanford of the Smithsonian Institution and Bruce Bradley of the University of Exeter.

In this hypothesis, peoples associated with the Solutrean culture migrated from Ice Age Europe to North America, bringing their methods of making stone tools with them and providing the basis for later Clovis technology found throughout North America. The hypothesis rests upon particular similarities in Solutrean and Clovis technology that have no known counterparts in Eastern Asia, Siberia or Beringia, areas from which or through which early Americans are known to have migrated.

2008-04-28T21:27:00.000-07:00

Green travel

Green travel is a method for people to travel while reducing their impact on the environment.

Some forms of green travel include:

* Use of walking, cycling, and public transport instead of car use, when possible.

* Use of biodiesel fuels.

* Taking advantage of ridesharing and carpools

* Booking travel through a green website like Green Travel by RezHub.com . They not only offers bookings with green travel suppliers (hotels, hybrid car rentals, carbon offstting), they also donate a portion of all revenue to a green organization.

* Stay at a green hotel or lodge.

2008-04-21T22:32:00.001-07:00

Transformation of culture

Transformation of culture, or cultural change, refers to the dynamic process whereby the living cultures of the world are changing and adapting to external or internal forces. This process is occurring within Western culture as well as non-Western and indigenous culture of the world. Forces which contribute to the cultural change described in this article include: colonization, globalization, advances in communication, transportation and infrastructure improvements, and military expansion.

2008-04-21T22:32:00.000-07:00

2008-04-14T21:18:00.000-07:00

Evolutionary prototyping

Evolutionary Prototyping (also known as breadboard prototyping) is quite different from Throwaway Prototyping. The main goal when using Evolutionary Prototyping is to build a very robust prototype in a structured manner and constantly refine it. "The reason for this is that the Evolutionary prototype, when built, forms the heart of the new system, and the improvements and further requirements will be built

When developing a system using Evolutionary Prototyping, the system is continually refined and rebuilt.

"…evolutionary prototyping acknowledges that we do not understand all the requirements and builds only those that are well understood."

2008-04-07T22:18:00.000-07:00

Life cycle of a relational database

The life cycle of a relational database is the cycle of development and changes that a database goes through during the course of its life. The cycle typically consists of several stages. There is possibility that the database designer/developer can go back to any of the previous stages. This represents an admission that a full understanding of a problem and its solution is likely to evolve as the various stages of design and implementation proceed. The typical eleven stages involved in the life cycle of a relational database are as follows:

BE AWARE THIS IS ONLY ONE VERSION, MULTIPLE DIFFERING VERSIONS EXIST

1. The designer must try to obtain as complete as possible an understanding of the real world problem that is going to be helped by the introduction of a database. This understanding of the nature of the problem and the constraints and outline feasible solutions is often performed using some systems analysis methodology.
2. The entity relationship diagram is drawn, and this diagram in its modified form serves as an essential part of the logical schema. Attributes of the entity types so produced are then added. Primary and foreign keys are specified.
3. Normalization is used to check the entity-relationship model. Some splitting and even recombination of entity types may result from normalization and the entity relationship model will have to be updated accordingly. The entity relationship model and the table definitions resulting from normalization should be consistent.
4. Set of Table(s) definition for the required schema is finalized.
5. The database tables are created. Primary, Foreign keys, database constraints and database integrity rules are specified at this stage.
6. At this stage, the file organization is performed. File organization is the way the database relations are to be stored on the storage medium. The file organization is decided on the basis of maximum speed of access, the type of access required and storage space considerations. There are two factors to consider; firstly how the records are to be physically mapped onto the storage medium, and secondly which indexes are to be used and if so, which fields (attributes, columns) are to be indexed. Indexes are designed to increase the speed of access to required records. Views can also be defined at this stage. Views are used to limit access to parts of database only, when used in conjunction with access privileges. Views also make programming simpler.
7. The designer will be able to design the required queries at this stage. The designer should have a good idea of the main types of query and reports the database will have to accommodate.
8. At this stage, application screens are designed. The application screens are used to capture the input information that will be kept in the database. Screen design is partially determined by the data items that must be input and output by particular applications and partially in human-computer interface terms. When designing screens, special consideration is given to the suggestions given by the application end users. There are published standards which can be exactly followed for screens design or organization can develop their own screen design standards as per their requirements.
9. Report design is another area where input from users is paramount. They will specify what they want to see on the reports and the format of the reports and in the case of regular reports, when they should be produced. Now-a-days most of the application design tools provide easy to use friendly tools for quick reports development. e.g. report builder in Oracle, Crystal Reports, R&R Report Writer etc.
10. Testing is performed at this stage. Application screens, various functions offered by the application screens, data validations through screens and reports are tested and it serves as the ultimate test of the correctness of the database schema and the viability of the system as a whole. It is recommended to create a test database separate of the production database. The test database will be useful for testing any schema changes and new and modified application before applying the changes to the production (live) database. Careful testing of the system before handover will minimize the expense of later modifications to the schema and major applications.
11. The final stage is Handover. This is the stage where the users receive the finished database and applications and begin data entry. In practice, it is likely that the core of the system will be handed over to users and later extensions to the system will be implemented.

2008-04-04T23:11:00.000-07:00

4th Dimension (Software)

4th Dimension (or 4D, or Silver Surfer, as it was known during early development) is a relational database management system and IDE developed by Laurent Ribardière in 1984. In 1993, 4D Server, the client/server version of 4th Dimension was introduced and since 1995, 4D has supported both the Microsoft Windows and Apple Macintosh operating systems.

The 4D product line has since expanded to an SQL front-end, integrated compiler and several productivity plug-ins and interfaces. Some of the more useful plug-ins include 4D Write (a word processor), 4D Draw (to draw shapes), 4D View (somewhat like a spreadsheet, but with extra functionality) and 4D Internet Commands (which let you add all sorts of Internet related functionality to a database). There are also over 100 third-party plugins, free and commercial.

2008-03-24T22:12:00.000-07:00

Application-level gateway

In the context of computer networking, an application-level gateway [1] (also known as ALG or application layer gateway) consists of a security component that augments a firewall or NAT employed in a computer network. It allows customized NAT traversal filters to be plugged into the gateway to support address and port translation for certain application layer "control/data" protocols such as FTP, BitTorrent, SIP, RTSP, file transfer in IM applications etc. In order for these protocols to work through NAT or a firewall, either the application has to know about an address/port number combination that allows incoming packets, or the NAT has to monitor the control traffic and open up port mappings (firewall pinhole) dynamically as required. Legitimate application data can thus be passed through the security checks of the firewall or NAT that would have otherwise restricted the traffic for not meeting its limited filter criteria.

2008-03-17T22:03:00.000-07:00

Waterfall model
The waterfall model is a sequential software development model (a process for the creation of software) in which development is seen as flowing steadily downwards (like a waterfall) through the phases of requirements analysis, design, implementation, testing (validation), integration, and maintenance. The origin of the term "waterfall" is often cited to be an article published in 1970 by Winston W. Royce (1929–1995),[1] although Royce did not use the term "waterfall" in this article. Ironically, Royce was actually presenting this model as an example of a flawed, non-working model (Royce 1970).

2008-03-09T22:35:00.000-07:00

Field emission display (FED)

A field emission display (FED) is a type of flat panel display using field emitting cathodes to bombard phosphor coatings as the light emissive medium.

Field emission displays are very similar to cathode ray tubes, however they are only a few millimeters thick. Instead of a single electron gun, a field emission display (FED) uses a large array of fine metal tips or carbon nanotubes (which are the most efficient electron emitters known), with many positioned behind each phosphor dot, to emit electrons through a process known as field emission. Because of emitter redundancy, FEDs do not display dead pixels like LCDs even if 20% of the emitters fail. Sony is researching FED because it is the flat-panel technology that comes closest to matching the picture of a CRT.

2008-03-04T01:30:00.000-08:00

Methods for solids

Computational chemical methods can be applied to solid state physics problems. The electronic structure of a crystal is in general described by a band structure, which defines the energies of electron orbitals for each point in the Brillouin zone. Ab initio and semi-empirical calculations yield orbital energies, therefore they can be applied to band structure calculations. Since it is time-consuming to calculate the energy for a molecule, it is even more time-consuming to calculate them for the entire list of points in the Brillouin zone.

2008-02-25T04:18:00.000-08:00

Satur

Saturn (pronounced /'sæt?n/) is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Along with the planets Jupiter, Uranus, Neptune it is classify as a gas giant (also known as a Jovian planet, after the planet Jupiter). It was named after the Roman god Saturnus, equate to the Greek Kronos (the Titan father of Zeus) and the Babylonian Ninurta. Saturn's sign represents the god's sickle (Unicode: ?), The day in the week Saturday gets its name from the planet.

The planet Saturn is calm of hydrogen, with small proportions of helium and trace elements. The interior consists of a small core of rock and ice, bounded by a thick layer of metallic hydrogen and a gaseous outer layer. The outer atmosphere is normally bland in appearance, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h, considerably faster than those on Jupiter. Saturn has a planetary magnetic field intermediate in strength among that of Earth and the more powerful field around Jupiter.

2008-02-19T03:48:00.000-08:00

Pineapple

The pineapple (Ananas comosus) is a tropical plant and fruit (multiple), inhabitant to Uruguay, Brazil, Puerto Rico, or Paraguay. It is a medium tall (1–1.5 m) herbaceous perennial plant with 30 or more trough-shaped and pointed leaves 30–100 cm long, nearby a thick stem. The pineapple is an illustration of a multiple fruit: multiple, spirally-arranged flowers along the axis each make a fleshy fruit that becomes pressed against the fruits of adjacent flowers, forming what appears to be a single fleshy fruit. The leaves of the cultivar 'Smooth Cayenne' mostly lack spines apart from at the leaf tip, but the cultivars 'Spanish' and 'Queen' have large spines along the leaf margins. Pineapples are the only bromeliad fruit in extensive cultivation. It is one of the most commercially important plants which take out Crassulacean acid metabolism, or CAM photosynthesis.

2008-02-11T20:46:00.001-08:00

Fixed asset

Fixed asset also familiar as property, plant, and equipment (PP&E), is a term used in accountancy for assets and goods which cannot easily be converted into cash. This can be differing with current assets such as cash or bank accounts, which are describe as liquid assets. In most cases, only tangible assets are also called as fixed.

It usually includes items such as land and buildings, motor vehicles, furniture, office tools, computers, fixtures and fittings, and plant and machinery. These frequently receive favorable tax treatment (deprecation allowance) over short-term assets because they depreciate in excess of time.

2008-02-04T20:55:00.000-08:00

Soil

Soil, comprising the pedosphere, is located at the border of the lithosphere with the biosphere, atmosphere, and hydrosphere. It consists of mineral, organic matter, as well as living organisms. Soil formation, or pedogenesis, is the combined effect of physical, chemical, biological, and anthropogenic process on soil parent material ensuing in the configuration of soil horizons.
Soil is our most important natural resources because of its position in the landscape and its dynamic, physical, chemical, and biologic functions. While the general concept of soil is well recognized, the definition of soil varies, according to the viewpoint of the discipline or occupation by means of soil as a resource.

2008-01-28T20:30:00.000-08:00

Inkjet printer

Inkjet printers activate by propelling various size (mostly tiny) droplets of liquid or molten material (ink) onto almost any media. They are the most common type of computer printer for the wide-ranging consumer [citation needed] due to their low cost, high quality of output, capability of printing in vivid color, and ease of use.

2008-01-21T21:13:00.001-08:00

Forest

A forest is a region with a high thickness of trees (or, historically, a wooded area set aside for hunting). There are many definitions of a forest, based on a variety of criteria. These plant communities cover large areas of the globe and function as animal habitats, hydrologic flow modulators, and soil conservers, comprise one of the most important aspects of the Earth's biosphere. Although often thought of as carbon dioxide sinks, mature forests are approximately carbon neutral with only disturbed and young forests acting as carbon sinks. Nonetheless mature forests do play a significant role in the global carbon cycle as stable carbon pools, and clearance of forests leads to an increase of atmospheric carbon dioxide levels.
Forests can be found in all regions talented of sustaining tree growth, at altitudes up to the tree-line, except where natural fire frequency is too high, or where the environment has been impaired by natural processes or by human activities.

2008-01-16T21:09:00.001-08:00

Batsman

A batsman in the sport of cricket is, depending on context: Any players will perform for batting. A player whose expert in the game is batting. During the play of a cricket match, two members of the batting team are on the field, although their team-mates wait off the field. Those two players are the existing batsmen. Each batsman stands near one of the two wickets also end of the cricket pitch near the centre of the ground.

The two batsmen have different roles:

The striker stands in front of the wicket nearest him and attempts to protect it from balls bowled by the opposing bowler from the other wicket. The non-striker stands stopped near the bowler's wicket. While protecting his wicket, the striker may also hit the ball into the field and attempt to run to the opposite wicket, exchanging places with the non-striker. This score a run, the two batsmen may continue to exchange places, scoring additional runs, until members of the fielding team gather and return the ball to either wicket.

2008-01-07T21:14:00.000-08:00

Membrane Filtration

A well-arranged process conduction which infact work without the addition of chemicals. Membrane technology is a generic term for separation processes. With membrane filters, filtration mainly occurs on the filter surface. Particles, which are larger than the normal pore size, remain on the filter, smaller particles pass through it unless other interactions get retained in them.

They are used to separate colloids, Suspended particles and molecules from liquids. Thus feed flow is divided into two streams a filtrate stream, and a highly concentrate stream.
Membrane systems with its filtration can be managed in either dead-end flow or cross-flow. The purpose of the optimization of the membrane techniques is the achievement, which is of the highest possible production for a long period of time, with acceptable pollution levels.

2008-01-03T22:13:00.001-08:00

Polymer

Polymer is a substance collected of molecules with large molecular mass collected of repeating structural units, or monomers, connected by covalent chemical bonds. The word is resulting from the Greek, πολυ, polu, "many"; and μέρος, meros, "part". Well known examples of polymers contain plastics, DNA and proteins.

While the term polymer in popular usage suggests "plastic", polymers consist of a large class of natural and synthetic materials with a variety of properties and purposes. Natural polymer materials such as shellac and amber have been in utilize for centuries. Biopolymers such as proteins (for example hair, skin and division of the bone structure) and nucleic acids take part in crucial roles in biological processes. A variety of other natural polymers survive, such as cellulose, which is the major constituent of wood and paper.

2007-12-28T03:31:00.001-08:00

Space Shuttle Solid Rocket Booster

The Space Shuttle Solid Rocket Booster is the rocket that provides 83% of liftoff thrust for the Space Shuttle. It is the largest and most powerful solid rocket ever flown, and the most powerful rocket motor of any type ever flown. Each SRB produces 1.8 times the liftoff thrust of the F-1 engine used in the Saturn V moon rocket.

The two reusable SRBs provide the main thrust to lift the Space Shuttle off the pad and up to an altitude of about 150,000 feet . In addition, the two SRBs carry the entire weight of the external tank and orbiter and transmit the weight load through their structure to the mobile launcher platform. Each booster has a liftoff thrust of approximately 2,800,000 lbf at launch. They are ignited after the three space shuttle main engines' thrust level is verified. The two SRBs provide 83 % of the thrust at lift-off. Seventy five seconds after SRB separation, SRB apogee occurs at an altitude of approximately 220,000 feet , after which they land on parachutes; impact occurs in the ocean approximately 122 nautical miles downrange, after which the two are recovered.

2007-12-17T22:11:00.001-08:00

Capital market

The capital market is the market for securities, where companies and the government can heave long-term funds. It includes the stock market and the bond market. Financial regulators, such as the U.S. Securities and Exchange Commission, oversee the capital markets in their selected countries to make certain that investors are protected against fraud. The capital markets consist of the primary market, where new issues are spread to investors, and the secondary market, where existing securities are traded.

2007-12-02T20:24:00.000-08:00

Art of Loving

According to Erich From, love is the most excellent reaction to the problem of human being. Love is the most satisfying accomplishment of humanity’s most powerful objective the desire of interpersonal union. Having a capability of grave thinking and self-awareness, humans realize their aloneness and separateness, their individuality and their short life span. The aspiration for interpersonal combination is the most powerful motivated in man. It is the most basic excitement; it is the force which keeps the human race together family, clan, society, nation, and world. As mentioned above, love, turns out to be the most fulfilling of all approach to go beyond limits of individual life. All forms of orgiastic unions are controlling and even violent; they are temporary and periodical. It is a union in which the individual self disappears to a large amount and where the aim is to belong to the group. There is orgiastic condition, which may have the form of sexual orgasm, alcohol, drugs and etc. Regrettably, equality today means similarity, rather that oneness. Orgiastic unions result in a rising sense of separateness. People try to be equal by performing tasks and feelings agreed by the system and trying to follow the similar rules, the same model of life from the age three or four. Union by consistency is calm and it is permanent.