Deductive / Inductive Reasoning

NTSB: Ferry crash caused by malfunction

Deductive / Inductive Reasoning

Deductive reasoning	Inductive reasoning
The malfunction of a solenoid in the propulsion system rendered one of the ships propellers unresponsive to propulsion commands (Valid reasoning if the solenoid is the sole control of the propellers)	The ferry Andrew Barberi slammed into the St George terminal (strong argument, dock damage, injury to persons)
An audio / visual alarm to warn the crew if the propeller was not responding may have prevented the incident (Valid the ferry could have been steered away from the dock if there was time)	Pilot house crewmembers were unaware of the loss of propulsion control (weak reasoning, ferry speed would be visual if the crewmembers were watching)
Audio visual alarms are not required on vessel types such as the Barberi (invalid, even though audio visual alarms are not required, they can still be fitted as a safety devise)	Andrew Barberi was involved in a previous incident in 2003 (weak reasoning, the previous accident had no bearing on this accident)
Safety management systems had improved since the 2003 incident (invalid, safety management systems couldn’t have prevented engineering design / mechanical failures)

Challenger disaster AcciMap

5 Whys of the Challenger disaster

Event: Astronauts couldn’t escape from disabled Space Shuttle during launch.

1.       There no Egress system on the shuttle:

2.       Weight / payload thrust limits

3.       Cost of per launch would increase by either smaller payload or bigger rockets

4.       Limited budget, NASA financial pressures

5.       US Government funding

 AcciMap

1 –Event
Astronauts couldn’t escape from disabled Space Shuttle during launch.
2-Organisation
Weight limits for the Shuttle design
3-Company
Cost per kilogram of payload to launch into space.
4-Government
Limited government budget for NASA
5-Societal
Public perception of NASA safety record

Shark Attack

Image from Google Images

On Saturday 31March a fatal shark attack in a diver in Western Australia occurred. The divers’ brother was diving with the deceased diver and recovered what was left of his brother. I couldn’t imagine what it would be like to see your brother killed by a shark and then have the unenviable duty of recovering his body and transporting him back to shore.

After authorities learned of the attack they went looking for the man killer shark. No order was given to kill the shark but the potential was to give the order. The question is why do sharks attack humans?

There is a perception that humans in dive wetsuits would look like seals to sharks under water. Seals are a favoured food source to the Great White shark, so if we looked like a seal then we would also be on the menu.
If we look like seals than why don’t we change the colour of the wetsuits? As light descends into water, the band widths of visible light are absorbed by the water starting with the reds at approximately 10m. At greater depths than ten meters, red disappears and whites appear blue, so changing the colour of wetsuits would not have any effect underwater.

Shark eyesight is said to be very good, indeed they are reported to be able to see extremely well particularly in reduced light. If their eyesight is good then why can’t they distinguish the difference between humans and seals?

Shark tourism could be a factor of shark attack. Cage diving to view Great White sharks is designed to attract sharks. Burly is poured into the water and then the sharks are further attracted by bait. Sharks may be associating divers with a food source due to this practice.
Image from Google Images
This time of year there are more bait fish schools closer to shore, which attract larger predator fish and they are then a food source for sharks. Early morning and late afternoon are predominately feeding times for sharks.

I believe that a possible solution to preventing shark attack on humans is for humans to understand a shark’s environment and behaviours. First we need to stop attracting sharks with food and cage diving. Educate people about the habitat of sharks and the behaviours such as feeding times and food source migrations.

Humans aren’t the sharks primary food source, if we were there would be many more people being taken.

References:

ReefQuest centre for shark research, 2007, Vision and a Carpet of Light, Biology of Sharks and Rays. Viewed 31/03/2012.

http://www.elasmo-research.org/education/white_shark/vision.htm

HOW WOULD AUSTRALIANS HANDLE AN EARTHQUAKE LIKE THE JAPAN QUAKE?

Figure 1 Accessed from Google Images

Last weekend was the first anniversary of the devastating earthquake, tsunami, and the Fukushima nuclear disaster in northern Japan.  Indeed 2011 was a dramatic year for natural disasters; floods and cyclones in Queensland, heat waves in Western Australia and Victoria, Earthquakes in Christchurch. In all, Australia pulled together to take these home disasters head on and I believe that we overcame the effects that nature could throw at us.  But not only did we have our hands full with our own disasters, but we also gave a helping hand to our neighbours’ in New Zealand, and we also sent our emergency services and military to help out in the tsunami affected areas of Japan. It was a proud time to be Australian, and I strongly believe that once again we showed the world what we are truly made of.

There was a story on Ninemsn last Saturday that warned of the real possibility of an earthquake hitting the Tokyo area. Japan scientists warned that ‘Tokyo is a city of 35 million people and is built on the intersection of four tectonic plates. The scientists believe Tokyo has a 50% chance of suffering a major earthquake, above a magnitude of 7.0, in the next four years’. The scientists estimate that 6400 people would be killed, 160000 people would be injured, 471000 homes and builds would be destroyed, 96 million tonnes of waste generated and would have an economic cost of 1.45 trillion dollars (Ninemsn 2012).

I then sat back and thought how would we in Australia handle such a disaster, considering our past natural disaster efforts; and how such an event in Japan would affect us in Australia and the rest of the world? The natural disasters that we have been exposed to in the past two years have happen over a vast area of the continent and over a period of time. There were also minimal fatalities compared to the Japanese earthquakes. I have no doubt that the Australian spirit would prevail, but how long would it take for the shock of the event to subside before we mobilised? The mud army mobilised in Brisbane after last year’s floods but in the aftermath of the clean-up it was realised that there were quite a few OHS issues that should have been addressed before the mud army was put to work, such as the asbestos risk. Luckily for many, the asbestos sheeting was still wet. After an earthquake the damage is a total different story with partially damaged buildings that are structurally unsound, people both alive and deceased trapped within buildings and rubble, hazards from building materials. You just can’t send the mud army in to clean it all up. What would our attitude be after a period of time?

Figure 2 Accessed from Google Images

The predicted cost should a greater than a  category 7.0 earthquake occur in the Tokyo area would be 1.45 trillion dollars. In the current world financial climate, surely this burden would cripple Japans economy for quite a period of time, and dramatically effect global financial markets.

Japan has 54 nuclear power plants, some within the bounds of Tokyo itself. In the event of a similar earthquake as occurred in northern Japan, what would the effect be on the population of Tokyo if a similar meltdown was to occur?

As I procrastinated on this I ended up with more questions than answers. One question that I am confident that I could answer was that Australians wouldn’t let each other down in a disaster no matter how devastating it may be.  

I look forward to your responses.

References:

http://news.ninemsn.com.au/world/8432008/quake-researchers-warn-of-tokyos-big-one