Electronics Michael Jordan

Where resolution defines the measurement of total screen capacity, aspect ratio defines a determination of scale. The term expresses a relationship of width to height as a ratio. For instance, a common aspect ratio 4:3 indicates that there are 4 inches in width for every 3 inches of height. The ratio means the same thing with yards, feet, or millimeters, etc. Aspect ratio means the exact same for displaying either photos or video clips. The definition predates the computer age.

In order to recreate a photo properly, the display’s aspect ratio should ideally equal the aspect ratio of the photo produced from the electronic camera. If the two aspect ratios don’t match, the display can stretch the image, or alternatively it can chop edges off of the picture to make it fit (called cropping). Another choice is often to resize the image, keeping its original aspect ratio, in order to fit either the width or height of the screen. This leaves unused portions of the screen at the two ends of the other (perpendicular) axis.

Most popular digital camera models create 4:3 pictures. The very same aspect ratio was used in old model television sets. Newer widescreen television sets employ either an aspect ratio of 16:10 or 16:9. These aspect ratios permit the familiar panoramic effect. Achieving a panoramic view still needs a camera that employs the same aspect ratio. Some digital cameras and frames use other aspect ratios. These are uncommon in typical consumer electronics. They are more used by experts and hard core enthusiasts. The salient point is to steer clear of unconventional aspect ratios if you lack a specific need.

Most people usually wouldn’t be concerned with mixing any of the 4:3, 16:9, 16:10 aspect ratios between displays and cameras. They all are near the equivalent ratio. Nevertheless, if one aspect ratio is translated into another, some mild distortion or stretching occurs. The most common effect of mixing them is an unused part of your screen. This is often either above and below the picture, or on the left and right sides of the picture, to keep it centered, and with correct proportion. It only becomes unappealing if there is a sizable disparity between the two ratios of the picture versus the display.

It is worth reviewing the image resize options that come with the digital photo frame you are thinking about. A serious deficit of image resizing options applies to a tiny assortment of best-selling digital frames. These particular photo frames don’t support picture cropping, plus they might not maintain the particular aspect ratio of your re-sized photos. This entails translating the aspect ratio of your picture to the aspect ratio the photo frame uses.

If the two aspect ratios are the same to start with, this type of resizing performs properly. If starting with unmatched aspect ratios, your satisfaction with the picture distortion, even if only slight, isn’t likely. It happens to be especially disappointing when this distorts the exhibition of one’s whole photograph gallery.

There are still reasons to buy this type of digital frame, providing you edit the collection prior to copying photos to the frame. These often have decent trade-offs, such as a higher than usual image resolution, or a much lower cost, or both. Viewsonic’s 10.2 inch frame, reviewed here: http://digital-picture-frame-reviews.com/10-2-inch-best/ is such an example. Editing can require a considerable effort. Even so, it can be cost-effective. It’s typically acceptable only when you are aware of the photo frame’s limitation ahead of time.

Copyright 2011 Wayne A Hynes

Switching to electronic locks has become a great option for many people. Keeping your valuables and important paper work safe is a top priority. Electronic locks give you the peace of mind you are looking for both for the home or the small business owner. Understanding how electronic locks work will help you make your decision regarding which one to buy for your purposes.

Electronic Locks Offer Extra Security

The new trend in electronic locks is being led by large security companies who are now able to offer safety systems that include a direct connection to the local emergency support system. They go way beyond the lock and key system that has been used for years, to offer even more security, as well as, ease of use. The new systems are able to offer your more security and more protection.

These new systems offer a level of security that heretofore has not been available. Electronic locks work using an electrical current. There are a variety of systems. Some are attached directly to the lock, while others are connected to a control system located elsewhere.

The Magnetic Lock

There are two major types of electronic locks on the market. One is the magnetic lock, or more popularly referred to as a mag lock. These locks use a magnet that is placed on the door frame that engages the armature on the door. The magnet holds them tightly together. This is a very easy lock to install and it is difficult to break into. They do require electricity to work and if the power source is disrupted the lock will not work.

The Electric Strike Lock

The electric strike lock is the one most often used in the buzz in types of systems. Instead of a standard strike, an electric strike is used that is hooked into an electronic mechanism. There are a variety of types of electric strike locks. Some are easier to install than others and some will work regardless of the availability of current and some will not.

Verification before Entry

The keystone of electronic locks is that they require some form of confirmation that you are allowed to open the lock. A numerical code is used most often that requires the person entering to type in the correct sequence of numbers in order to gain access. Once the code is entered correctly the lock will disengage.

Another method of verification used is a key card or pass card that must be scanned or swiped to gain entrance. Many businesses use this type of electronic lock to enter offices, elevators and garages.

A third method that is growing in popularity is biometrics, which is a fancy name for fingerprint scanning, retinal scanning and voiceprint identification. Places where a high level of security is required most often use this type of electronic lock.

Now that you know what types of locks are available, you can begin to consider what type of lock will work best for you. These locks offer such an increased level of security for the average person; it only makes sense to replace the old fashion lock and key with an electronic lock as soon as possible.

The curvature of earth produces two effects firstly it reduces the difference in the path lengths between the direct and ground reflected waves by raising the point of reflection above that of a plane earth and as a result tends to reduce the strength of the received field, secondly curvature of the earth causes the reflection at the ground to take place from a spherical rather than a flat surface so that the reflected ray becomes divergent and consequently becomes weaker at the receiving point. This tends to increase the field strength of the total space wave at the receiving point. These two opposite effects produced by the earths curvature almost neutralize each other. As a consequence, the assumption of a plane earth yields results which remain valid in spite of considerable curvature of earth. The condition in the troposphere keeps on changing with time. Hence the amount of bending of refraction of waves also changes from time to time. This influences the relative path length of the direct and the ground reflected components of space wave. Hence the field strength of the resultant space wave at the receiving point changes, i.e. fading of the wave results. Small but abrupt discontinuities in the dielectric constant of air existing at the boundaries of air masses of widely different characteristics result in mirror like reflections. Such reflections may cause signal to be received at the points beyond the line of straight range. Fading may also be caused.

The distance traveled by the direct ray in the troposphere from transmitting antenna to the receiving antenna and the field strength of this direct ray at the receiving antenna. If the reflection at earth is prefect, the magnitude of the field strength due to ground reflected ray will be approximately equal since the total distance traveled by the indirect ray is approximately equal to the distance traveled by the ray. However the reflection co-efficient at the ground is p then the magnitude of the indirect ray is equal. The direct ray and the ground reflected ray combine vector ally at the receiving antenna. The phase difference in the two field strength is caused by the following two factors, path difference and phase shift caused due to reflection from ground. We revel, some important properties of the propagation of very high frequency. The field frequency strength increases linearly with the height of the transmitting antenna, linearly with the height of receiving antenna, linearly with the square root of the effectively radiated power. The field strength varies with the wave length and inversely with the square of the distance. In all we can say earths curvature has many effects on troposphere propagation.