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Database Programming
Databases are collections of tables that maintain and display information, often collaboratively; this information can be used for interaction with an application or gaining general knowledge. Questions about database engines and modifying or using them belong in this category.
8,803 Questions
How do you access objects dropped in the vent?
You should use a vaccuum cleaner and suck it back up,chances are that it is stuck or resting on dirt and that should let you retrieve it. Just make sure you use something like a shop-vac or something that does not grind the contents it picks up.
The only time you should calculate it instead of storing is when you only use that attribute once. Otherwise, store it to avoid repeating calculations.
What is the line coding scheme used for the DS-1 signal?
the line coding can be either AMI or B8ZS according to how the equipment is set up along the path and at either end.
Which is bigger a megabite or gigabite?
Kilo come from the Greek meaning 'thousand' and is used to name one of the powers of 10, 10 to the 3rd power, 10^3 or 1,000. Commonly named 'one thousand.'
Mega comes from the Greek meaning 'great' and is used to name one of the factors of 10, 10 to the 6th power, or 10^6. This value is 1,000,000. Commonly named 'one million.'
Giga comes from the Greek meaning 'giant' and is used to name one of the factors of 10, 10 to the 9th power, or 10^9. This value is 1,000,000,000. Commonly named 'one billion.' Having said that, it is easy to see that giga is bigger than mega.
Which is faster CL3 memory or CL5 memory?
cl3 CL - CAS Latency (column access strobe) refers to the number of clock cycles taken to read or write a column of data off a memory module. The lower the latency, the faster the read/write. RL - Row access strobe Latency (RAS Latency), similarlly, measures cycles taken to read\write a row of data.
An action query is one that makes some adjustments to your database or the data. It would include things like queries that delete records, update records, create tables and so on. Other queries just do things like list your data but don't make any changes to it.
What do you mean by Direct file organization?
A relatively small project that is similar to past effort might be best accomplished using the?
What is binary tree traversal?
- as you visit each node the first time you follow the left branch, if it exists.
- as you visit each node the second time you follow the right branch, if it exists.
- when a node has no branches or you have visited all the branches it has, revisit the node above it.
The Unified Modeling Language™ (UML®) is a standard visual modeling language intended to be used for
- modeling business and similar processes,
- analysis, design, and implementation of software-based systems
UML is a common language for business analysts, software architects and developers used to describe, specify, design, and document existing or new business processes, structure and behavior of artifacts of software systems.
What different types of file processing system?
sequential file organization
index file orgaization
diect file orgaization
Who can you stored the image in database and then retrive it?
We can store images as well as files in database. Use this code for Onclick event of upload button :-
protected void btnUpload_Click(object sender, EventArgs e)
{
string strImageName = txtName.Text.ToString();
if (FileUpload1.PostedFile != null && FileUpload1.PostedFile.FileName != "")
{
byte[] imageSize = new byte[FileUpload1.PostedFile.ContentLength];
HttpPostedFile uploadedImage = FileUpload1.PostedFile;
uploadedImage.InputStream.Read(imageSize, 0, (int)FileUpload1.PostedFile.ContentLength);
// Create SQL Connection
SqlConnection con = new SqlConnection();
con.ConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
// Create SQL Command
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "INSERT INTO Images(ImageName,Image) VALUES (@ImageName,@Image)";
cmd.CommandType = CommandType.Text;
cmd.Connection = con;
SqlParameter ImageName = new SqlParameter("@ImageName", SqlDbType.VarChar, 50);
ImageName.Value = strImageName.ToString();
cmd.Parameters.Add(ImageName);
SqlParameter UploadedImage = new SqlParameter("@Image", SqlDbType.Image, imageSize.Length);
UploadedImage.Value = imageSize;
cmd.Parameters.Add(UploadedImage);
con.Open();
int result = cmd.ExecuteNonQuery();
con.Close();
if (result > 0)
lblMessage.Text = "File Uploaded";
GridView1.DataBind();
}
}
Memory contention is a state a OS memory manager can reside in when to many memory requests (alloc, realloc, free) are issued to it from an active application possibly leading to a DOS condition specific to that application. Memory contention is typically not caused by a memory overflow by all joined allocation requests but rather by the frequency of joined reallocation requests issued! Is is not about the joined memory size allocated but about the reallocation request queue size that overflows! A typical symptom of an application suffering memory contention and therefore not anymore being served memory management requests by the operating system, is that it unexpectedly shuts down without any form of notification.
What is the difference between field research and field study and field work?
As a geologist I use these terms interchageably.
If you want to be more precise, "field work" could refer to every visit to the area subject of study. All the data collected from several "field work" campains result on a "field study". "Field research" could be more generic, and interchangeable for any of the other two.
What is a proposed form of order?
A proposed order is a preliminary form of a written order that one lawyer prepares to put in writing an oral decision by a judge. If there is a motion, say for an order to compel the other party to appear at a deposition, the court makes a ruling from the bench verbally. Normally, whichever lawyer won on the motion prepares the proposed form of order. It is always possible that the lawyer preparing the order makes some mistake in wording or leavies something out that should be in, or adds something that shouldn't be in. In order to avoid this, most courts require the lawyer preparing the order to send a proposed form of order to the court and the other lawyer for review. Tho other lawyer has a right to object to the wordin. If no objection is made or if one is made and dealt with by the court, the proposed form of order is either signed as is or modified to become the final form of the order.
What data type is suitable for password field?
We never store passwords in a password field. If we did that, anyone with access to the database would have access to all the passwords. Instead, we store the output from a one-way cryptographic hashing function. That is, when a user creates a password, we store the hash value generated from that password via the hashing function. When the user subsequently enters their password in order to log on, the hash value generated by the entered password is compared with the stored hash value. If the two hash values match exactly then the correct password was entered.
Being one-way, it is not possible to determine the password from the hash value, even if we know the precise implementation details of the hash function employed to create the hash value. This is the safest way to store passwords; we simply need to ensure that the same hash function that was used to generate the hash is also used to validate the user's password at logon.
Cryptographic hashes can vary in length depending on which function was used to generate the hash value. Typical values are 128-bit, 160-bit, 256-bit and 512-bit, thus a fixed-length binary field of the required length would be suitable for storing the hash values.
What is the difference between absolute referencing and absolute replication?
one says referencing the other says replication
What is the advantage of data gloves?
Data Glove is a device to interact with animated artificial objects. Consider a glove fitted with sensors and electrical wires hooked to a glove compatible computer. Here, we can see our hand inside the glove in the display monitor of the computer. As we rotate or move our hand and manipulate our fingers, we can see our hand inside the glove in the display monitor of the computer. Consider further that a graphic object is described in the monitor. The object may be animated. It may even be a scaled replica of a real life object. Now , if we try to move our hand in space in such a way that the image of our hand in the display manipulates the graphic object in the screen,we shall have a strange feelings. With out actually touching anything, we may distort the shape of the object using the image of our hand inside tha dataglove! This glove act as an agent to transport the user to an artificial domain.
Data Glove-A part of Haptic science:-
Data Glove is a part of Haptic science. Haptics is the science of applying tactile sensation to human interaction with computers. A haptic device is one that involves physical contact between the computer and the user, usually through an input/output device, such as a joystick or data gloves, that senses the body's movements. By using haptic devices, the user can, not only feed information to the computer but can receive information from the computer in the form of a felt sensation on some part of the body. This is referred to as a haptic interface. For example, in a virtual reality environment, a user can pick up a virtual tennis ball using a data glove. The computer senses the movement and moves the virtual ball on the display. However, because of the nature of a haptic interface, the user will feel the tennis ball in his hand through tactile sensations that the computer sends through the data glove, mimicking the feel of the tennis ball in the user's hand. So, we can say Data-glove is a glove -like input device for human-computer interaction, often in virtual reality environments,it records hand position and orientation as well as finger movements. Wearing the data glove a user can grasp objects, move and rotate them, and then release them providing very natural interaction in 3D.
This CyberGlove from Virtual Technologies is an example of a data glove. The wearer is playing a simulated 'ballgame'. As he views the monitor, his hand movements are translated onto the screen via the data gloves. Each of the gloves in the picture contain 18 movement sensors.
TECHNOLOGY BEHIND IT:-
Electromagnetic transducer and strain gauge sensing devices are used to pick up the position and orientation of the data gloves. It is a glove covered with small light weight sensors. Each sensor is a short length of fibre -optic cable with a LED at one end and a photo-transistor at the other end. A polhelmus 3 SPACE three -dimensional position and orientation sensor records hand movements. Often a motion tracker, such as a magnetic tracking device or inertial tracking device, is attached to capture the global position/rotation data of the glove. These movements are then interpreted by the software that accompanies the glove, so any one movement can mean any number of things. Gestures can then be categorized into useful information, such as to recognize Sign Language or other symbolic functions. Data gloves are sometimes called "Wired gloves" or "cybergloves".Expensive high-end wired gloves can also provide haptic feedback, which is a simulation of the sense of touch. This allows a wired glove to also be used as an output device. Traditionally, wired gloves have only been available at a huge cost, with the finger bend sensors and the tracking device having to be bought separately.
An alternative to wired gloves is to use a camera and computer vision to track the 3D pose and trajectory of the hand, at the cost of tactile feedback.Motion capture, motion tracking, or mocap are terms used to describe the process of recording movement and translating that movement on to a digital model. It is used in military, entertainment, sports, and medical applications, and for validation of computer vision and robotics. In film-making it refers to recording actions of human actors, and using that information to animate digital character models in 2D or 3D computer animation. When it includes face and fingers or captures subtle expressions, it is often referred to as performance capture.
History Behind It:-
The Sayre Glove, created by Electronic Visualization Laboratory in 1977, was the first wired glove. In 1982 Thomas G. Zimmerman filed a patent on an optical flex sensor mounted in a glove to measure finger bending.
One of the first wired gloves available to home users in 1987 was the Nintendo Power Glove. This was designed as a gaming glove for the Nintendo Entertainment System. It had a crude tracker and finger bend sensors, plus buttons on the back. This was followed by the CyberGlove, created by Virtual Technologies, Inc. in 1990. Virtual Technologies was acquired by Immersion Corporation in September 2000. In 2009, the CyberGlove line of products was divested by Immersion Corporation and a new company, CyberGlove Systems LLC.
In addition to the CyberGlove, Immersion Corporation also developed three other data glove products: the CyberTouch, which vibrates each individual finger of the glove when a finger touches an object in virtual reality; the CyberGrasp which actually simulates squeezing and touching of solid as well as spongy objects; and the CyberForce device which does all of the above and also measures the precise motion of the user's entire arm. In 2002, the P5 Glove was released. It worked as a 2 dimensional mouse and a few computer games were specially adapted to provide "3D" support for it. The P5 glove is compatible with Microsoft Windows XP and Mac O/S version 9 or below.
Unofficial drivers for Linux exist as well. The P5 Glove is 5th Glove. A data glove and flexor strip kit (5th Glove DFK) sold by Fifth Dimension Technologies. The package uses flexible optical-bending sensing to track hand and arm movement. The glove can be used with 5DT's ultrasonic tracking system, the 5DT Head and 5DT Hand tracker, which can track movement fom up to two metres away from the unit's transmitter.
A recent development in wired gloves is the ShapeHand developed by Measurand Inc. ShapeHand is ideal for use in applications like the hand-over because it uses flexible sensors that are not physically built into a glove, so it can attach to most hand sizes.
Concerned about the high cost of the most complete commercial solutions, Pamplona et al. propose a new input device: an image-based data glove (IBDG). By attaching a camera to the hand of the user and a visual marker to each finger tip, they use computer vision techniques to estimate the relative position of the finger tips. Once they have information about the tips, they apply inverse kinematics techniques in order to estimate the position of each finger joint and recreate the movements of the fingers of the user in a virtual world. Adding a motion tracker device, one can also map pitch, twist, roll and XYZ-translations of the hand of the user, (almost) recreating all the gesture and posture performed by the hand of the user in a low cost device.
Variety Of Datagloves:-
i) Datagloves by 5DT:-
There are a variety of gloves which can be used for capture of hand motions. Motion Capture gloves range in price from roughly $2000 per pair for wired or $3500 per pair for wireless up to approximately $40,000 per pair for top of the line 22sensor Cybergloves. Differentiating factors include the number of joints sensed. A fivesensor glove measures curl of each finger but cannot differentiate the degree of movement per knuckle. Basically, the 5 sensor gloves record the curl of each finger, from open palm to closed fist. Sixteen sensor glove record each finger joint and add 'adduction' (recording how close or far apart each finger is). 22 Sensor gloves measure motions of the palm, including more complex motions of the palms. Meta Motion supplies Datagloves from Fifth Dimension Technologies (5DT) and Cybergloves from Immersion 3D.
ii) 5DT Data Glove 5 Ultra:
Measures finger flexure (1 sensor per finger) and the orientation (pitch and roll) of the user's hand. It can emulate a mouse as well as a baseless joystick. The system interfaces with the computer via a cable to the serial port (RS 232 - platform independent). It features 8-bit flexure resolution, extreme comfort, low drift and an open architecture. .
iii) 5DT Data Glove 14 Ultra:-
A14-sensor data glove that measures finger flexure (2 sensors per finger) as well as the abduction between fingers. It is the higher-end version of the 5DT Data Glove 5.
Features:- Affordable quality Extreme comfort One size fits many Automatic
calibration :- minimum 8-bit flexure resolution
Platform independent :- serial port interface (RS 232) Cross-platform drivers Bundled software High update rate On-board processor Low crosstalk between fingers Wireless version available (5DT Data Glove 16-W) Quick "hot release" connection.
iv) Open-Source Data Glove:-
AcceleGlove :-
Gloves that are wired with sensors can provide useful information about a user's motions, and they offer a novel way to interact with computers beyond the keyboard and mouse. At the end of May, AnthroTronix, a company based in Silver Spring, MD, released its first commercial version of the AcceleGlove, a
programmable glove that records hand and finger movements. Other gloves-like 5DT's Data Glove, used primarily in virtual reality-normally cost $1,000 to $5,000, but the AcceleGlove costs just $499. It comes with software that lets developers use Java to program it for any application they wish. AnthroTronix initially developed the glove with the U.S. Department of Defense for robotic control. The glove could also be used in video games, sports training, or physical rehabilitation.
Why use Data glove:- The data glove has opened up a whole new world in the medical department. Surgeries for medical students can now be practiced on "fake people" in virtual reality while the medical students can feel the "fake" scalpel in their hands!. Hospitals could use the data glove to deliver physical therapy sessions to the patients . It could also be used for diagnosis, allowing a doctor to feel a human organ via the Internet . This technology could also enable users of the glove to master activities in sports or music.If we knew the exact pressure a professional athlete put on a ball or bat, we could mimic their motions with the data glove. The same can be said for musical instruments.
Why teachers are using Data Glove?
The data glove offers in valuable educational advantages . We know that "Tactile sensation is the brain's most effective learning mechanism, more effective than visual or auditory, which is why the new data glove technology holds so much promise as a teaching tool",so that many universities are following this technique now a days,but the problem is that the teachers of the core subjects (such as math, english, history, and science) in elementary education or secondary education are not yet getting the full benefits out of the data glove.
Application areas of Data-glove:-
1)To teach the deaf children/physically challenged people.
2)Sign Language Education.
3)Music in Education : AMIS (Algorithmic Musical Interactive Space).
4) Chemistry and Biology (simulating 3D molecules, proteins, and DNA).
5)Multimedia Education: Technology, Music, Video.
6)Physical Education/Coaching: If we could simulate the exact way one
should hold a bat, ball, hockey stick, etc(especially by a professional athlete) then teachers/coaches would be able to teach to a whole new level.
What is the difference between reports and queries?
query takes a table and given the criteria entered into it it displays the results that meet that search. While a report just spits out a table in the database
How do you insert files into a database using PHP?
Im not entirely sure what you mean. But say you have some text you want to save and load later on... you can put it into a database (e.g. MySQL) or even better a flat file database (e.g. a simple text file). Say for example you have a chatbox. And you want to save the text into a .txt file so u can load it later on using php as well. However if you want to save important data (e.g. passwords credit card information) then i would recommend using a proper database like phpMyAdmin. If u need to no more just send an email to wasim-ilyas@hotmail.co.uk (my email address). Thanks,
Wasim Ilyas
How do you access the shared reporting function?
Select the Reporting high-level task, the the Custom Reports link
Why do i get 500kbps download if i have 5mb download speeds?
Your ISP measures, and sells, bandwith in megaBITS per second, while web browsers and other software measure file downloads in megaBYTES per second.
Since there are 8 bits per byte, with some overhead for control and error correction, a 5 MegaBITS per second (5Mbs) internet connection _should_ download at about 500 kiloBYTES per second (5KBs).
Capital B for bytes, small b for bits.
If you are downloading files at 500KB/s on a 5Mbs connection, it is working fine.
Just divide the BITS per second of your connection by 10 to get the approximate BYTES per second you should be downloading at.
Is it faster to read and write a csv or sqlite file?
The answer to this question really depends on the data base engine (that is the server software) being used to store the information. If, for instance, you are using MS SQL as the engine, it will naturally write all it's information into a SQL file, or the engine will be used to write into a stand-alone SQLLite file (where no actual server software is running).
In any case, most database engines will write to their own native files to help minimize read/write times. This is because CSV files are both a blessing and a curse. They are universal ASCII Comma Separated Value files that can be read by anything - even Notepad. This makes them easily transferrable from any system to another. However, they pretty much have to be read AND written to in SEQUENTIAL order. In a database containing a few thousand records, that could be a long Update execution time.
In summary, it is extremely faster for a database engine to use it's native file format. However, CSV's are mainly for import/export purposes and transferring data from one system to another.
