When an aircraft pitches up or down the tailplane rotates around the cg of the aircraft and this motion causes a change in the tailplane’s angle of attack, which generates a change in lift at the tailplane. This change in lift at the tailplane in conjunction with the tailplane’s arm from the cg generates an opposing, or damping, pitching moment.
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During a rocket launch the commentator will often call out “Max Q” at a specific point in time during the launch. This is the point at which the dynamic pressure acting on the rocket will be at it’s maximum.
The dynamic pressure or Q is the product of the air-density and the velocity squared of the object travelling through the air.
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In the mid 1980s while I was in high school my father bought me an Apple II, well actually a clone of an Apple II from Hong Kong. He had been a helicopter pilot in the air force and had then become an airline pilot, hence the Hong Kong connection.
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The last reported location for MH-370 from Malaysian military radar is N6.6381 E96.408 at 18:22UTC. If we assume some maximum ground speed for the next 78 minutes until the 19:40UTC satellite ping then the intersection of the maximum aircraft range from the time of the last radar contact until the 19:40UTC satellite ping will define the northernmost and southernmost points on the 19:40UTC ping ring that the aircraft could have reached.
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For each ping between the aircraft and the Inmarsat satellite we have the range/elevation angle between the satellite at that time (satellite is moving) and the aircraft and we have the Burst Frequency Offset (BFO) Doppler data.
So the LOS speed between the satellite and the aircraft along the LOS vector is as follows:
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I’ve used the tagging feature in the original Windows Vista Photo Gallery and the Windows Live Photo Gallery versions for tagging people in photos and the location of the photo.
The latest version of Windows Live Photo Gallery now includes a specific ‘People’ category separate from the generic tags category for identifying people in photos.
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Recently I needed to create a bitmap of some WPF controls to be used in another program. Doing a quick search turned up references to the RenderTargetBitmap class in WPF with sample code along the lines of:
RenderTargetBitmap bmp = new RenderTargetBitmap((int)element.Width, (int)element.Height, 96, 96, PixelFormats.Pbgra32); bmp.Render(element); However if the WPF control had a margin then the rendered bitmap had transparent pixels for the margin area.
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I was approached recently to help develop some Flight Test Instrumentation (FTI) for a Hawker Hunter jet to be used during a test pilot course involving high angle of attack manoeuvres and spinning.
The following data needed to be recorded:
Angle of Attack (AoA) Angle of Sideslipe (AoS) Attitude (pitch, roll and heading) Indicated airspeed and altitude Stick and rudder position GPS Video In addition to recording all the data listed above they also wanted to display a subset of the data in the cockpit as an aid for spin recovery.
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I came across the Google paper on MapReduce again the other day and decided to try a simple implementation using C# generics allowing you to specify specific types for the keys and values as opposed to being forced to use strings for all keys and values.
The initial version doesn’t include any automatic parallelism across multiple CPUs or clusters of machines.
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I started playing around with generating HDR photos. Here is one of my first attempts using our Pentax DSLR.
I’m using a trial version of Photomatix to perform the HDR processing and tone mapping which is why you’ll notice their watermark in the HDR image below.
I set the auto-bracketing option on the camera to shoot a normal exposure, a -2 stop exposure and a +2 stop exposure.
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