Visual Basic 6.0 Lecture Notes Pdf

[Frida Kosofsky]

TheMay of 2000 final exam studyguide/outline is very extensiveand has lots of suggestions and practice questions to guide you.Thursday April 13th and 20th, hands-onclass times and guidelines.Database assignment is due on Thursday,April 20th.All of the code and screen snapshots are on a one page, two sided handoutfrom Tuesday, April 11th class. You can also see them and more databasestuff here. You may turn your MOVIES database assignment in on Friday, if you attend the lab class on Thursday. DO NOT SKIP class to work on VB.Its way counterproductive to skip VB because you are having trouble withVB.Private Sub mnuOpen_Click()' theFileName = InputBox("What file would you like to try?" & vbCrLf _' & "Example 1: A:\mygraphic" & vbCrLf _' & "Example 2: Z:\web\mybutton.gif") cdbDialog.DialogTitle = "Open a favorite graphics picture" cdbDialog.Filter = "*.gif;*.jpg;*.bmp" cdbDialog.FileName = "*.gif;*.jpg;*.bmp" cdbDialog.ShowOpen pic.Picture = LoadPicture(cdbDialog.FileName)End SubDialog Box Basics, chapter 12 of the textbook, was covered on Tuesday, April 4th. You may use the FileOpen method instead of the InputBox statement for the mirror it graphics File menu Open command, if you wish to. Here is the Mirror It graphics program assignment. It is due on Thursday, April 6th.You have the VB code as a handout for the Mirror It graphic palindrome creating assignment. Copies are taped to my office door for those students who missed class.It also contains an extensive database example using a Moviesdatabase. The VB application is a movie guessing game. Guessing whatmovie a quoted line or portion of dialogue was from is the task for theplayer of your game.The database examples are very, very rough draft HTML and must becleaned up and updated from fall of 1999.Visual Basic online documentation you can browse to. This is theMSDN online Library link, shown on the Tuesday, February 29th handout.The chapter on databases in the text is Hour 15, pages 245-266.Databases and Visual Basic will be covered on March 30th, April 4thand April 6th.The Data control was introduced on March 28th. The Connect property,DatabaseName property, RecordsetType property and RecordSource propertyof the Data control were introduced. TextBox and Label controls have a DataField and a DataSource property.Any control having these two properties is called a Data Bound control,and can be connected to a field in a database through a Data control. The next quiz will be on Thursday, March 23rd. Itwill cover the following material.Hour 10 ListBoxes and the ListBox control and handouts andlectures. Hour 11 Additional Controls and all related handouts and lectures. Hour 17 Menus and all related handouts and lecture notes. Lecture notes since the beginning of the class.Hour 10 (ListBox and ComboBox) will be includedon the next quiz. We started Hour 10 material on the Thursday before spring break. There was ahandout for the ListBox control, which extended the usefulness of the graphic file browser program.What to printout and turn in for the Menus and Shapes program?Setting the proper hsbWidth (Horizontal Scroll Bar) properties. The Min of 0 is NOT allowed! The Form As Text, the Code for the entire project (for both forms). Your File menu, Print dialog will look like this Four screen snapshots of the running program. You need to use PrintScreen without the Alt key, and then Crop the graphic. There will be explanation here later today (Tuesday) or by Wednesday afternoon at the latest. (HOW TO CROP).

Lecture Notes Provide life time free access to material and Toppers Training Institute provide Unit-2: Visual programming lecture notes (Visual Basic Programming) Training / Explanation Classes with P.R.Engineering college - Toppers Institute Staff.

The optic nerve leads from the eye to the optic chiasm. The optic chiasm is where some of the fibers cross. The optic tract proceeds from the optic chiasm to the lateral geniculate nucleus (LGN). The optic radiation leads from the LGN to primary visual cortex (V1).

There are two eyes, thus we illustrate two visual fields. The fixation point is the center of the visual field; it corresponds to the fovea. T he vertical meridian splits the visual fields into left and right hemi-fields. The horizontal meridian splits the visual field into upper and lower hemi-fields. The blind spot is the region of the visual field that corresponds to the optic disc.

Principle of lateralization: The right half of the brain receives sensory information from and sends motor commands to the left half of body. In the visual system, the right half of the brain receives information about the left half of the visual field (note: not just from the left eye). Note that the fibers cross over at the optic chiasm.

Visual deficits due to lesions at different points in the pathway: Suppose someone comes in complaining of vision problems. Do you send them to an ophthalmologist or to a neurologist? Is the problem an eye disease? Or is it some central problem like a tumor pressing on the optic tract?

If the deficit is in only one eye's visual field, send the patient to an ophthalmologist. If the deficit is in corresponding parts of both eye's visual fields, then it is a central problem, and send the patient to an neurologist for an MRI or CT scan.

In the LGN, cells have center-surround receptive fields just like retinal ganglion cells. There is little or no information processing beyond that done in the retina, so what is the function of the LGN? Why not send axons directly to cortex? Nobody knows for sure. There are two compelling hypotheses that I know of:

All 6 layers of LGN project to area V1 in cortex. The magno and parvo layers project separately in the input layers of V1, but then these parallel pathways (that originated in the retina) get pretty much completely merged in subsequent areas.

The figure below shows the results of an experiment in which an anaesthetized monkey viewed a flickering bulls-eye pattern, and was injected with radioactively labeled glucose. The glucose was taken up by active neurons. The animal was then sacrificed, and V1 was surgically removed and flattened. The flattened V1 was then used to expose radioactively sensitive film. The result is a picture of regions of activity evoked by the bulls-eye. As you can see, V1 maintains a retinotopic map.

In the intact human brain, V1 is located in the occipital lobe. The retinotopic map is laid out across the folded cortical surface in the gray matter of the Calcarine sulcus. The central (foveal) part of the visual field is represented at the very back and more peripheral regions of the visual field are represented further forward (anterior). The retinotopic map is lateralized so that the left hemisphere V1 represents the right half of the visual field and vice versa.

The retinotopic map in V1 is distorted so that the central 10 degrees of the visual field occupies roughly half of V1 (orange regions in the above diagram). This makes sense because of the poor acuity in the periphery (recall that peripheral ganglion cells have large dendritic trees and pool over many photoreceptors). The distortion is called cortical magnification.

David Hubel and Torsten Wiesel won the Nobel prize for discovering the functional organization and basic physiology of neurons in V1. They discovered three different types of neurons that can be distinguished based on how they respond to visual stimuli that they called: simple cells, complex cells, and hypercomplex cells. V1 neurons transform information (unlike LGN cells whose receptive fields look just like those of ganglion cells) so that they are orientation selective and direction selective.

In class we viewed a video that demonstrates how Hubel and Wiesel classified the various cell types and mapped their receptive fields. You can download this movie (clicking above) but be aware that it is a large movie file. The video shows visual stimuli while recording from each of several V1 neurons. The electrode was connected to an amplifier, and output to a loudspeaker. The audio track allows you to hear the loudspeaker - each click corresponds to an action potential. The movie shows examples of a simple cell, complex cell, direction-selective complex cell and a hypercomplex cell.

Orientation selectivity: Most V1 neurons are orientation selective meaning that they respond strongly to lines, bars, or edges of a particular orientation (e.g., vertical) but not to the orthogonal orientation (e.g., horizontal).

These are data from Hubel and Wiesel's early experiments on V1. The dashed rectantangles on the left indicate a V1 neuron's receptive field. The superimposed lines are the stimuli that were used. For each stimulus (each line orientation), Hubel and Wiesel recording how many action potentials were produced by this neuron. The middle row are exampls of the electrophysiological recordings for each of the corresponding stimulus orientations. The diagonal orientation (the middle row) evoked the greatest response (largest number of action potentials). The graph on the right shows the result after a whole bunch of measurements like these for each of a bunch of lines. There is a peak response for one particular orientation and weaker responses for other orientations, falling of to zero when the line orientaiton is about 40 degrees away from the neurons favorite (preferred) orientation).

Direction selectivity: Some V1 cells are also direction selective meaning that they respond strongly to oriented lines/bars/edges moving in a preferred direction (e.g., vertical lines moving to the right) but not at all in the opposite direction (e.g., vertical lines moving to the left).

These are also data from Hubel & Wiesel's early experiments. The arrows above each electrophysiological recording indicate the direction of motion. This V1 neuron responds best to up-right motion but not at all to down-left motion.

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