Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Jackknifing shopping experience:
1. Compare - without doubt the biggest advantage that the Jackknifing offers shoppers today is the ability to compare thousands of Jackknifing at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Jackknifing? Wrong! If the Jackknifing is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Jackknifing then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Jackknifing? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Jackknifing and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Jackknifing wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Jackknifing then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Jackknifing site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Jackknifing, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Jackknifing, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
Jackknifing means the accidental wikt:folding of an articulated vehicle (i.e. one towing a trailer) such that it resembles the acute angle of a folding pocket knife. If a vehicle towing a trailer skids, the trailer can push it from behind until it spins round and faces backwards. This may be caused by equipment failure, improper braking, or adverse road conditions such as an icy road surface.
Jackknifing is not very common and usually only happens to an empty vehicle. Most truck drivers are skillful enough to correct a skid before it becomes a jackknife. It would be an exaggeration to claim that jackknifing accounts for a large number of
Semi-trailer truck accidents since in many cases it is the collision that would have caused the vehicle to jackknife and not vice versa. Radio stations often report jackknifed trucks because people phone to tell them, but more often than not, the truck has not technically jackknifed; it may be stuck in the snow or damaged in a crash.
Trailer swing
When a trailer skids to one side, this is known as a
trailer swing or
trailer slew. This could happen on a slippery road surface, often where there is a camber.
This is not the same as jackknifing and is not serious since the trailer moves back into line as the vehicle continues forwards. The driver must be aware however, that the trailer could slide up against parked cars or the wheels could slide into a ditch.
Anti jackknife devices
Over the years systems to combat jackknifing have been developed.
- One system with limited success was a device that limited the angle which a trailer could swing.
- A much more successful system was to fit the tractor with anti-lock brakes. Fitted originally to planes in the 1950s, anti-lock brakes have not noticeably reduced the number of car accidents but have significantly reduced the number of heavy vehicle accidents.
- The most important device that has prevented jackknifing over the years is the load-sensing brake-pressure regulator. This is a simple device which reduces the brake pressure to the rear wheels of an empty vehicle so that it does not spin around and face the other way when the brakes are applied. Since this device is fitted to almost every vehicle it is taken for granted, but without it cars would frequently spin off the road and empty articulated vehicles would be almost impossible to stop in a straight line.
- Prime movers used to be fitted with a lever in the cab to operate the trailer brakes. The vehicle could be slowed down or stopped using the trailer brakes only. Theoretically this was a sure way to prevent jackknifing, but truck drivers will have noticed the recent disappearance of this lever from their cabs. The reason being that this lever was often the cause of jackknifing in a round about way. Frequent use of the trailer brakes alone caused them to overheat and brake fade while the tractor brakes remained fresh. In the event of an emergency stop, the driver would go straight for the foot brake and the truck would surely jackknife because the tractor brakes would lock while the trailer brakes would be ineffective.
- An alternative to having a trailer brake lever in the cab is to fit the trailer with an electromagnetic brake.
- A new device called the "Atlas AJSS" has recently been invented that automatically engages at a speed of 45 mph and stays engaged unless manually released. It is actuated electronically and operated pneumatically from the truck's accumulator air supply. The device prevents the trailer and the truck from becoming over 15° out of alignment with each other. Under normal operating (highway) speeds, this 15° swing does not interfere with driving even on the most winding roads; of course, the system disengages under 45mph to allow for the hair-pin curves of winding mountain roads which are traversed at speeds under 45mph.
Jackknifing means the accidental
wikt:folding of an
articulated vehicle (i.e. one towing a trailer) such that it resembles the acute angle of a folding
pocket knife. If a vehicle towing a trailer skids, the trailer can push it from behind until it spins round and faces backwards. This may be caused by equipment failure, improper braking, or adverse road conditions such as an icy road surface.
Jackknifing is not very common and usually only happens to an empty vehicle. Most truck drivers are skillful enough to correct a skid before it becomes a jackknife. It would be an exaggeration to claim that jackknifing accounts for a large number of Semi-trailer truck accidents since in many cases it is the collision that would have caused the vehicle to jackknife and not vice versa. Radio stations often report jackknifed trucks because people phone to tell them, but more often than not, the truck has not technically jackknifed; it may be stuck in the snow or damaged in a crash.
Trailer swing
When a trailer skids to one side, this is known as a
trailer swing or
trailer slew. This could happen on a slippery road surface, often where there is a camber.
This is not the same as jackknifing and is not serious since the trailer moves back into line as the vehicle continues forwards. The driver must be aware however, that the trailer could slide up against parked cars or the wheels could slide into a ditch.
Anti jackknife devices
Over the years systems to combat jackknifing have been developed.
- One system with limited success was a device that limited the angle which a trailer could swing.
- A much more successful system was to fit the tractor with anti-lock brakes. Fitted originally to planes in the 1950s, anti-lock brakes have not noticeably reduced the number of car accidents but have significantly reduced the number of heavy vehicle accidents.
- The most important device that has prevented jackknifing over the years is the load-sensing brake-pressure regulator. This is a simple device which reduces the brake pressure to the rear wheels of an empty vehicle so that it does not spin around and face the other way when the brakes are applied. Since this device is fitted to almost every vehicle it is taken for granted, but without it cars would frequently spin off the road and empty articulated vehicles would be almost impossible to stop in a straight line.
- Prime movers used to be fitted with a lever in the cab to operate the trailer brakes. The vehicle could be slowed down or stopped using the trailer brakes only. Theoretically this was a sure way to prevent jackknifing, but truck drivers will have noticed the recent disappearance of this lever from their cabs. The reason being that this lever was often the cause of jackknifing in a round about way. Frequent use of the trailer brakes alone caused them to overheat and brake fade while the tractor brakes remained fresh. In the event of an emergency stop, the driver would go straight for the foot brake and the truck would surely jackknife because the tractor brakes would lock while the trailer brakes would be ineffective.
- An alternative to having a trailer brake lever in the cab is to fit the trailer with an electromagnetic brake.
- A new device called the "Atlas AJSS" has recently been invented that automatically engages at a speed of 45 mph and stays engaged unless manually released. It is actuated electronically and operated pneumatically from the truck's accumulator air supply. The device prevents the trailer and the truck from becoming over 15° out of alignment with each other. Under normal operating (highway) speeds, this 15° swing does not interfere with driving even on the most winding roads; of course, the system disengages under 45mph to allow for the hair-pin curves of winding mountain roads which are traversed at speeds under 45mph.
Jackknifing - Wikipedia, the free encyclopedia
Jackknifing means the accidental folding of an articulated vehicle (i.e. one towing a trailer) such that it resembles the acute angle of a folding pocket knife.
Resampling (statistics) - Wikipedia, the free encyclopedia
... randomization test, or re-randomization test) Validating models by using random subsets (bootstrap, cross validation) Common resampling techniques include bootstrapping, jackknifing ...
jackknifing - Definitions from Dictionary.com
noun . 1. a large pocketknife.
jackknifing-trailer swing-brakes-braking
Jackknifing The rig jackknifes when the drive axle brakes lock up.
FRB: Jackknifing Stock Return Predictions
Jackknifing Stock Return Predictions Benjamin Chiquoine and Erik Hjalmarsson 2008-932 (June 2008)
Jackknifing Stock Return Predictions
Board of Governors of the Federal Reserve System International Finance Discussion Papers Number 932 June 2008 Jackknifing Stock Return Predictions Benjamin Chiquoine and Erik ...
Traffic Jackknifing
TOOLBOXTOPICS.COM. Company Name _____ Job Name _____ Date_____ TRAFFIC JACKKNIFING. Do you know how to handle a jackknife?
Jackknifing
Jackknifing. Jackknifing is a special type of interpolation which can be useful in analyzing a scatter point set or an interpolation scheme. When the Jacknifing command is ...
What is "Jackknifing" With a Horse-drawn Four Wheeled Vehicle?
What is "Jackknifing" With a Horse-drawn Four Wheeled Vehicle? ... Did you ever ask yourself why a two-wheeled vehicle is safer for a beginner?
Jackknifing
Dear S-Plus users, I am attempting to jackknife binomial GLM models (with both continuous and categorical parameters) in an attempt to produce ROC curves for model validation.
