Hazard Definition and 26 Threads

I want to use crystals from China for baby jewelry and it turns out that they use lead for the crystals - is there a risk of exposure through the skin to these crystals for babies

In the exponential distribution, the hazard rate is constant. The hazard rate does of course not always have to be constant, but can also be a function of time, which then leads to different distributions. But my question is: what is the stochastic process called that underlies this type of...

Hi , I am based in Australia and my question originates from some grey areas in the Australian system of classifying pressure vessels. I am guessing most users on this forum are US based . Does the US have a system for classifying pressure vessels such as air receivers , boilers, autoclaves...

Last night about 2am (checked cctv). The 2001 honda crv car hazard light suddenly turned on in the parking (its that button at the middle above the aircon). When i found out at 7am. The car couldn't start so i connected the jumper, hence asking the question in another thread. Has anyone ever...

Homework Statement "Suppose that the accident rate for one workplace ##A## is ##k## times the rate of another workplace ##B##. In other words, ##\lambda_A(t)=k⋅\lambda_B(t)##. Conclude that the probability of no accidents in workplace ##A## is the probability of no accidents in workplace ##B##...

In the making of firework explosives, the explosive mixtures are handled with great care to avoid static electricity induced detonation of the explosives. Is it a good idea that they store the explosives in a plastic container - isn't there a risk of static buildup that could detonate the...

Hi, I recently bought a glow-in-the-dark key chain, similar to http://tinyurl.com/zqf5sxb (image link). It is made from solid plexiglass, with a hollow cylinder in the middle, containing tritium. The electrons from the beta decay presumably hit a fluorescent wall on the inside of the cylinder...

We have various threads and posts on the topic of the Earth's magnetic field. Now, "a new mapping effort by the US Geological Survey (USGS) shows how the hazards of geomagnetic storms are not the same all over Earth — and they're especially worrisome in northern Minnesota," and particularly up...

For the past year or so, I've been experimenting with Isobutane. I used to get it in relatively cheap canisters of r600a from amazon.com and AliExpress, and that worked fine. Now, however, AliExpress has NO purchase options for r600a, and amazon.com will not ship it to the US, even though they...

Many modern cars now employ radar systems for intelligent cruise control as well as blind spot monitoring. Can the radar waves that are reflected back to the vehicle for these applications pose a health hazard to the vehicle occupants?

Homework Statement Homework Equations My professor gives us the following formula: [ tex ] F_j(t) = \int\limits_0^t exp\Big\{-\sum\limits_{j=1}^J \int\limits_0^u \lambda_j^{\#}(v)dv \Big\} \lambda_j^{\#}(u)du[ / tex ] where [ tex ]\lambda_j^{\#}(t) [ / tex ] are the cause-specific...

At 9:30 am yesterday, all employees where I work (on the edge of a forest) received the following email (marked with a red exclamation mark):

lim(∫λu du) when limit T tend to infinity and ∫ between 0 to t

So I have a question relating to how the negative exponential distribution arises when talking about probability, more specifically, when deriving a probability from a rate. I believe it involves concepts related to the hazard function, as well as Taylor series expansions. Hopefully someone...

F(t) = 1-Exp -((t-γ)/n))^β f(t) = dF(t)/dt = Exp/n[(t-x)/n]^β-1 h(t) = f(t)/1-F(t) h(t)= β(t-y)^β-1/n^β The final answer: h(t)= β(t-y)β-1/n^β, Is the correct answer. But, I can't for the life of me work out why. Have I made a mistake in the f(t) derivation. Can anyone help?

Hi, I'm currently trying to work through a problem about calculating the most likely time for a hard disk to fail: Hard disks fail with a probability per unit time: \alpha (t) = \alpha _0 t where \alpha_0 = 0.5 years. I know that the answer is t_{modal} = \frac{1}{\sqrt{\alpha_0}}, but am...

Hi - the building community where I live has just installed a few Wi-Fi ("sector", I believe) antennas and one of them is at same height and facing straight into my apartment. They are probably 10-15 meters across my apartment. I have a one year old son, and concerned about any health effects...

My roommates were using Tin Foil under the stove burner to prevent the base from getting messy. One instance when I was cooking soup, the contents spilled onto the base covered by the tin foil. The contents started to burn and I saw flames. Tin foil has a very high melting point. I can't...

I've always felt my finger "tearing" when I used my laptop's touch bad. I now noticed that I do in fact have a cut there. And on my 2nd finger, which I've also used on the touch pad. Do you think this thing is out to get me? If it matters, I use Linux. Should I go back to Windows? Do...

Homework Statement The number of years that a washing machine functions is a random variable whose hazard rate function, h(t), is given by - 0.2 if 0 < t < 2 - 0.2 + 0.3(t - 2) if 2 <= t <= 5 - 1.1 if t > 5 If the washing machine is still working six years after being purchased, what...

Chlorfoam is a very powerful single stage detergent disinfectant, it is formulated to produce a stable clinging foam giving long contact times Specific gravity 1.14 pH 1% solution 12.3 Active Alkalinity 5% w/w as Na2O Active Biocide 3% Av. Cl (1% v/v solution gives 350 ppm Av. Cl This...

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I really doubt that anybody would help me out on this...because by experience, nobody ever replies to the stats stuff on this forum... But i'll try anyway Question the hazard rate function is: h(t) = lamda > 0 ...... for 0 =< t =< 50 h(t) = lamda + alpha(t - 50) ... for t> 50...

http://www.edge.org/q2006/q06_print.html#greene Brian Greene writes, "If true, the idea of a multiverse would be a Copernican revolution realized on a cosmic scale. It would be a rich and astounding upheaval, but one with potentially hazardous consequences. Beyond the inherent difficulty in...

Anyone know how to find the hazard function when given the survival function. I am able to calculate the cumulative hazard function, but cannot find a formula for just the hazard function. survival function is: S(t)=e^(-at-bt2)

"Large meteorites are more likely to break up in the atmosphere before they hit the Earth than was previously thought, scientists in Britain and Russia have calculated." http://www.nature.com/nsu/030714/030714-11.html