Rick F Guyon - Measures of Central Tendency - Richard F Guyon

Measures of Central Tendency

It is often unnecessary to present the experimental data in their entirety, either in tabular or graphical form. In such cases, the data and distribution can be represented by various parameters. One type of parameter is a measure of central tendency, Mode, median, and mean are measures of central tendency.

The mode is the observed value that occurs most frequently. The mode may vary greatly between series of observations. Therefore, its main use is a quick measure of the central value since little or no computation is required to find it. Beyond this, the usefulness of the mode is limited.

The median is the point in the distribution that partitions the total set of observations into two parts containing equal numbers of observations. It is not influenced by the extremity of scores on either side of the distribution. The median is found by counting up (from either end of the frequency distribution) until half of the observations have been accounted for.

Similar in concept tot he median are percentiles (percentile ranks) quartiles and deciles. The median could also have been called the 50th percentile observation. Similarly, the 50th percentile would be the observed value for which the cumulative frequency was 80%. The quartile and decile points on the distribution divide the observations or distribution into segments off 25% and 10%, respectively.

Rick F Guyon - Road Safety Features - Richard F Guyon

Road safety features are installed to protect public life and property and to reduce traffic-related lawsuits against highway and transportation departments. The most common actions include the installation of illumination, guardrails, and impact attenuators, as well as the relocation of dangerous facilities.

Guardrails are used on roadways where there is a severe slope or vertical dropoff to the side of the road, ditches, permanent bodies of water, embankments, and roadside obstacles. Guardrails with turned-down ends are now prohibited in new installations and should be upgraded. Such guardrails, rather than protecting motorists from a fixed impact or spearing, often cause vaulting and subsequent rollover.

Rick F Guyon - Richard F Guyon - Road Safety

Rick F Guyon - Coefficient of Friction - Richard F Guyon

Rick F Guyon  - In most cases, a vehicle's braking system is able to provide more braking force than can be transmitted to the pavement. Therefore, the maximum deceleration is limited by the coefficient of friction between the tires and pavement.

The coefficient of friction, f, between a vehicle and the supporting roadway is the frictional force divided by the normal force. The normal force is essentially the total weight of the vehicle, w , on all but the most extreme grades. The coefficient of friction is dependent on the condition of the vehicle's tires, the type and condition of the pavement, and the weather conditions. 

There are two coefficients of friction: static and dynamic(kinetic). The coefficients of friction may also be referred to as coefficients of road adhesion. The coefficients of static friction is larger than the coefficient of dynamic friction. While a vehicle's tires are rotating, the relative velocity between a point of contact on the tire and roadway are zero and the coefficient of static friction controls. 

Once a vehicle enters a skid, however the coefficient of dynamic friction controls. Therefore a vehicle is held to its maximum braking deceleration without entering a skid will take less distance to come to a complete stop than if the vehicle locks up its tires and skids to a stop. 

The coefficient of friction is not constant throughout the braking manuever, but varies inversely with speed. This level of sophistication is not normally considered, and an average value that is representative of the speed and conditions are used.

Rick F Guyon - Refresher: Systems of Units - Dimensional Analysis - Richard F Guyon

Dimensional Analysis

Dimensional analysis is a means of obtaining as equation that describes some phenomenon without understanding the mechanism of the phenomenon. The most serious limitation is the need to know beforehand which variables influence the phenomenon. Once these are known or assumed, dimensional analysis can be applied by a routine procedure.

The first step is to select a system of primary dimensions. The dimensional formulas and symbols for variables most frequently encountered are given .

The second step is to write a functional relationship between the dependent variable and the independent variable.

Rick F Guyon - Dimensional Analysis - Richard F Guyon

Rick F Guyon - You Need to Travel! - Richard F Guyon

It's crazy when you read about the stats of Americans who have never travelled outside of their county....let alone outside of their state...let alone out of the country. It's absolutely absurd. EVERYONE NEEDS TO TRAVEL.

Ok...why is travel so important?

• The only thing you take with you are memories....material things means absolutely nothing.

• You gain a different look on things. When you live in your little small town only knowing a one group or a specific group of people your view on things that are outside of that circle are very narrow minded. Traveling the world and learning about other cultures, learning new languages and seeing new things is how we learn.

When a baby is still new he/she puts everything in his mouth. He wants to see everything, touch everything...this is how we learn. If you don't expand your mind and/or your horizons then what have you learned? What have you gained?

Rick F Guyon - Genetically Modified Food.

Rick F Guyon - Now I'm no scientists....but I wonder if people truly care about the whole GMO thing or is it just a fad to distract the 99% of some serious other issues or things that are happening right now. 

As much as people want to talk about Monsanto...the US Market's fish supply is all genetically modified. All of our meat is genetically modified....unless otherwise stated. All of our veggies are genetically modified. And even if a farmer did not have that intention it's not impossible for those plants to cross breed with a genetically modified plant causing its offspring to be genetically modified. Ok...so where do you start? Where do you go? What do you eat?

Good question. Let me know when you figure that one out.

Rick F Guyon - Things in Perspective

Rick F Guyon - When you look up at the night sky….you are looking at the past. The nearest sun closest to our sun takes 4 years for its light to reach us. That means that what we see is the remains of light from 4 years ago. Think about it. The universe is so vast and expansive….and we know little to nothing about it. Just to think we don’t even know our own bodies. We don’t have the cure to cancer….you haven’t explored the oceans. Our technological advances have really just come within the last 100 years.

When you think about it makes you think about what we do know. How little we know. And with that small ounce of knowledge we do have maybe we shouldn’t assume to know it all.

Rick F Guyon - Taking the time to just breath

Rick F Guyon - Soooooo today I woke up and admired the natural beauty of my home. Sometimes we get carried away with what we have to do. Whether it's the next research project, the next step, all the tasks and errands we have for the day....it's hard to just stop and breathe.

There is a saying I love. It says:

"Don't take life too seriously...It's not like you are going to make it out alive."

Makes you stop and chuckle. The only thing that comes to us all is death and taxes. So chill out...take 10 minutes out of your day to admire where you are and your life so far. Then when that is all done you can go back to your hectic day. I have a lot of work to do today but I know I am a lot more productive when I'm in a restful state of mind. - Richard F Guyon