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Wednesday, April 9, 2014

A New Story For the Missing MH370

9 April 2014
 
A tweeter,  by the name of Jonathan Langdale,   got hold of a published ping data and analysed the signal from Inmarsat that tracked the pinging frequencies of Malaysian Airline MH370 that went missing on 8 March 2014.  He has told his “story” to many including CNN but no one listened.

What is his story?


Jonathan Langdale,  a flight simulator fanatic with some flying experience,  believed that MH370 took a large turn back at where it disappeared from the screens on the night of 8 March 2014.  The pilots then dropped the plane down to 12,000 feet with intention to perform an emergency landing at the Terengganu Airportbut they were knocked out completely,  leaving the plane flying south,  passing West of Singapore towards the Indian Ocean on auto pilot in a "kicked off" mode.

 
 
In his March 30thprediction,  he gave his first prediction without making wind adjustment which he corrected afterwards.   He said this last prediction run on track along the location where the Chinese vessel,  Haixun01,  detected the first pinger signal.  He reckoned that he had over projected the length of the flight path.


His detailed analysis is covered here

How he came to this “story”?


According to his earlier tweets,  he claimed that he followed the published Doppler effect frequency shift data closely.  He said  

1)     The ping data showed that the ping frequency increased from 140 hz to 275 hz,  while it was making a turn back;

2)     The frequency then dropped back to 140 hz which indicated a possible attempt to perform an emergency landing at the Trengganu Airport;

3)     The frequency increased from 125 Hz to 250 Hz,  indicating that the plane flew at constant speed until the fuel run out.  

He claimed that MH370 did not fly west over to Penang as was told by the Military radar.  He said the radar could have tracked another plane.

His timing accounts using the Inmarsat's pinging data is shown below
 





He read also about some villagers at the Marang Beach sighted a very large plane flying around 1:20 am and these villagers made a police report the next morning.
 
 
 

Is his story credible?


Langdale,  by far has the most credible story besides the official one.  Both the Langdale’s and the official ones  ended the flight in the South Indian Ocean except the final destinations varies somewhat due to errors in the educated guesses.  The only difference  is that the official one advocated that there was a deliberate act to fly MH370 to avoid radar detection whereas the Langdale’s story appears to suggest that MH370 may have had some troubles with the plane (fire?) and the pilots had no time to call Mayday.  MH370 then flew South directly without any detection by other Malaysian’s radars as well as the Singaporean’s and the Indonesian’s  radars.

According to many reports,  the investigators who analysed the Malaysian military radar data indicated that the plane did fly at a height of 43,000 to 45,000 feet before dropping down to 12,000 feet.  Because the plane carried about 200 kgs of Lithium batteries,  there were rumors saying the plane could have flown  to a height of 43,000 feet intentionally to extinguish a fire onboard.  Some said the pilot is a technical fanatic who might just want to try this "trick",  choosing to fly another 8.000 feet in 10-20 minutes or another 60 minutes to reach the nearest airport.   As it was not a standard procedure,  the pilots could have switched off the ACARS recording or isolate the fire by switching off the power.  These stories and rumors, though remote,  blend well with Langdale’s story that the pilots were knocked out rather than the official story that there was a deliberate attempt to avoid the radar detection. 

Can the military radars miss the plane?


It is “impossible” for MH370 to avoid all radar detections in all the countries where MH370 was travelling, an aviation analyst said.  Unlike the United States, Britain, Australiaand New Zealand, countries in this region do not have a pact to share their signals intelligence, including satellite and radar data.

Malaysia military primary radar spotted the plane flying west and disappeared from the screen which has a 200 km range.

If MH370 did cross into the airspace of other countries unnoticed, a Weber said it would also mean that the air defense in those countries might be a bit lax in the wee hours of the morning.  The experts pointed out that military radars are expensive to operate and there might be remote chances that these radars were switch off until a trans-boundary tension is building up.  If that is being the case and  in all likelihood,  these countries would not disclose that they have missed the detection of MH370 because it would not look good on them,  especially to their citizens.  It is also a truth to tell others that their radars did not detect any unidentified plane which does not mean the plane did not fly pass through their air space.

Weber continued to say that countries might not be prepared to compromise and put aside their own security concerns to share data that might give away their defense capabilities just for finding a missing aircraft.  They were of the view that “defense is not just about capability, but also about hiding such capability or the lack of it”.   Not many countries will publicly admit to using classified technologies to find the aircraft.  What the public could read would be those non-classified capabilities or technologies;  for example,  the weather satellite images.
 

 

Conclusion

 
There are just too many stories out there in the cyber world including the official ones that said MH370 was deliberately flew west toward Andaman sea and turned south,  ending its journey in Southern Indian Ocean,  West of Australia.  The Langdale’s  story appears to tell similar tale except for the part about MH370 turning  back for emergency landing at Terengganu Airport.   One would never know the likely truth until the where about of the plane is found.

Monday, April 7, 2014

A Review of an Economical Digital Time Switch from Q0010

7 April 2014

Introduction

Bought a digital time switch from Q0010 last week for about SGD $12/= to replace my present mechanical time switch which has been used to control a 3-litres Jojirushi water air-pot that  draws about 3.0 -3.5 amperes.  The digital time switch has no other name on it except “Timer” on its cover.  It is made in China 

Differences between Digital and Mechanical Time Switches


The main difference is in the construction. 

The mechanical time switches on the left have gears and wheels that are driven by an electric motor synchronised to the electrical mains.  These wheels rotate a time dial that can be programmed to activate a level that will turn on or off a micro-switch to control the electricity supplied to the socket outlet.
The digital time switches on the right have no gears, wheels and moving parts.  The timing is driven by a digital clock much like an ordinary quartz alarm clocks except in this case,  instead of activating a mechanical switch that turn-on the alarm circuitry,  the digital time switches have electrical relays that control the electricity supplied to the socket outlet.

Dismantling the Digital Time Switch


It is quite easy to open the casing of the time switch by first finding the two “catches”,  one at each end of the time switch as shown,  then use a small screw driver to carefully pry open the casing which will “pop up” from its base readily. 

The Electronics and Components 


The digital time switch has 3 components 

1)     the switch socket outlet assembly

2)     the supply unit and the output relay

3)     the time clock and display screen

Description of the Circuits 


The supply for the electronics is obtained through a simple transformerless power supply unit that consisted of a 400 volt supply capacitor,  a power limiting 1 ohm resistor and a full wave rectifying bridge.  The power supply unit is supplying a 24 volts dc supply to run the relay circuits as well as 1.2 volts to charge the Nickel Metal Hydride  (Ni-MH) battery and also to run the time clock and display unit as shown in the attached.

The time clock and the programming electronics are hidden behind the display screen’s circuit board


The relay has a name plate rating of 16 ampere @ 240 volts.  The unit has a spare battery chamber which is not used,  probably left over from the older design that used AAA rechargeable batteries. 

The Rating of the Time Switch


Although the name plate of the time switch has a rating of 13 amperes,  the driving electronic has relay rating of 16 amperes. This,  however,  does not mean the time switch can be used for appliances with current rating of  13 amperes so long as it is less than 16 amperes.   This is because most of the appliances have inherited electromotive force (emf)  during starting up or switching on.   For example,  appliances with electric motor can induce current sometimes as high as 12 times the rating of appliances for as long as 10 seconds during starting up.  That back emf induced could easily damage the time switch if there are frequent start-ups even though the rating of the appliance is less than 3 amperes.  As a rule of thumb,  it is not advisable to load more than 4 amperes for most appliances with or without motor start ups.

Heating up of the Time Switch


Time switch will heat up although its electrical components consume little or no electricity.  This is because there are always resistances in the socket outlet's  connection and the wiring.  A typical resistance of 0.3 ohms in the connection circuit will give up about 2.7 watts of heat if the current is 3 amperes.  Try touching an electric light bulb of about 3 watts,  one would always find it warm to touch.     

Comparing to Mechanical Time Switch


This digital time switch was running cooler than the mechanical time switch probably for 2 reasons

1)     The mechanical one consumes slightly more power;
2)     The mechanical one is a bit old giving rise to higher contact resistance.

Programming


The programming is quite straightforward.  The unit has 8 buttons in 2 lines.   The top ones (3 to 7) are for adjusting and setting the weeks,  hours,  minutes and an R/Recall button to cancel or recall the program.  The bottom ones are for setting of clocks and do the programming with an extra button for manual/auto  turning on and off the time switch.



As usual,  the manual coming along with the unit is written probably by a technical guy who assumed everyone if fully versed with function of the time switch.  It is only with trial and error can one started to understand what was written in the manual.  Fortunately,  nothing will destroy the time switch if one is playing around with the buttons without the unit connecting to any power mains.

The Life Span of Battery


All rechargeable battery has a certain life.  For Ni-MH battery, it is not more than 5 years;  after which,  one would have to replace it.  The unit is supplied with a button or coin type of battery which is often seen in laptop/desktop computers for the CMOS circuits.   The battery is not readily from the neighbourhood store.  One might be able to get them  from Sim Lim Tower at a cost of about SGD$6/= each.  Fortunately,  the unit came with a spare battery chamber that one could easily convert the button or coin battery into an AAA Ni-MH battery if one is familiar with soldering.  The AAA battery is easily and readily available from local stores.

Delivery


The track and trace list of Q0010 shows that the unit was prepared for shipment on 31 March and reached the delivery partner by 1 April who delivered it on 3rdApril.  The cost of delivery is another SGD$4/= or about 30% of the unit cost.

Conclusion


This time switch is a worthwhile investment.  It works very well compare to the mechanical time switch with flexibility of weekly programming which a mechanical time switch cannot offer.   The only snag is that it came with a button or cell Ni-MH battery which is not only expensive to be replaced,  it is also not readily available.   The alternative is to replace the whole unit or convert the battery to the AAA type;  fortunately,  this problem only comes after 5 years.

Manuals






Thursday, April 3, 2014

How To Repair Electronic Equipment with Button Switches

3 April 2014

Introduction


These “critters”,  button switches,  are often used in our electronic equipment whenever there is a button designed to be pressed either to reset a program or to do the programming.

These buttons are cheap but they are often not lasting especially those in the cheaper electronics equipment such as door bells or some remote controls. One would need to press the buttons extra hard in order to sound the door bell or to activate the remote control.


Why?

There are 2 reasons:

1. The current that passes through the buttons is not enough to overcome the “dirt” building up at the contacting point. When the contacts of the button are making or breaking, there will be “sparks” no matter how small, these “sparks” will usually “blow” the dirt building up in the contacts.   If the current is too small,  the sparks created will not be able to "blow" off the "dirt".

2. The current that passes through the button is too strong, hence,  causing sparks to “eat away" the metal of the contact surface and therefore, building carbon resistance enough to prevent the passage of the current.

How to Repair?

First, remove the buttons carefully,  making sure the circuit board is not damaged, then

1. Replace the buttons

This is the best option.

2. Open up the button and then clean the contact. 

This will require some skills to break open the cover and then reseal it after cleaning. Not often successful

3. Pass a small current through the button using a torchlight battery with as many pulsation clicks as possible  (i.e to click the button switch as quickly as possible, say 20 clicks) until the ohms meter measurement across the button switch shows consistent low resistance readings. Do not leave the button switch  close for too long as this will short-circuit the battery.

Method 3 may not necessary work when the contacts of the buttons are completely charred and worn. In that case, the only workable solution is to replace the button switch.   However,  method 3 may be a quick method as it could be done "in circuit"  when one can isolate the switch from the circuit. In the case that one torchlight battery cannot do the job and the button switch came back with the same problem,  try maximum 2 nos of batteries working in series.

Wednesday, March 26, 2014

I Saw Missing Malaysia Airlines Flight MH370 In Water – Woman says

26 March 2014 

Introduction 


Malaysian flight  MH370 went missing on 8 March with 239 people on board.  It was en routed from Kuala Lumpurto Beijing.  The experts now pin-pointed the plane's location to be about 2,500 km west of Perth,  Australia.  Till date,  there is still no sighting of the plane nor its debris.  This article is not offering any expert view but some arguments and pictures from another angle. 

The Johor Housewife


A Johor housewife, Mrs Latife Dalelah, claimed that she saw an aircraft  half submerged in the waters  at about 2:30 pm  Malaysian time (same for the rest)  when she was returning to Kuala Lumpur after a pilgrimage to Mecca on 8 March.   The news said that she took Saudis flight SV2058 that left Jeddah at 8.30am but actually,  she took Saudis flight SV2798 and not SV2058 as shown in the attached. 
 



Flight Path of SV 2798

According to flightradar’s flight history,  Saudis Airline SV2788’s flight path is as shown.  On 8 March 2014,  SV 2798 took the red dotted path  flying over Chennai of India.


Using the flight data found at flightrada24,  one could determine that flight SV2798 was  above Chennai at around 1300 hour (5:00 UTC).  It then jumped to show SV2798 at the marked location at 1500 hours as there was no data in flightradar24 for 2 hours between the two time intervals on 8 March.    If one interpolates the time and distance,    one could find the rough location where  Mrs Latife Dalelah sighted the airplane at 14:30 hours.    It was at a distance almost perpendicular to the site where Tomnod map 4543, 5239 and other maps were located.  





The same is shown on  a google earth map where Tomnod maps were tagged.


Update:

For those interested in finding out the co-ordinates of the various Tomnod maps using Google Earth or Google Map can download this file.   It will load and appear automatically in Google Earth or map. To get the co-ordinates,  click the "direction" at the bottom.


 What is Tomnod map?

Tomnod is a website where it allows volunteers to spot and tag any object using satellite images.  So far,  some of the maps showing possible debris findings were circulated around in various forums and twitted around as shown in the Appendix.
 

Can one see object from a plane flying at around 35,000 feet?

Many web articles said can.  One of them claimed that we could see a 737 plane or smaller ones from 30,000 feet and  777 is almost twice the size of 737.  He assumed that one should have a normal vision, or vision that was corrected to be normal.   

This website offered a calculator that says that human eyes can see an object about 250 miles away from 35,000 feet.  This is  roughly the distant from where  Mrs Latife Dalelah was to the Tomnod maps.
 



The Satellite Pinging 


The experts used doppler effect of the satellite pinging and the 4 pings to pin-point the where-about of MH370.  Although this Doppler effect of satellite pinging was never used before to locate a plane,  many,  including the Malaysian PM,  have accepted it beyond reasonable doubts.  This Doppler effect concept appears to go against Mrs Latife Dalelah’s plane sighting because the plane was not moving after it had crashed. It could not have been providing the satellite pings with Doppler effect throughout the next 4 hours.   The only logical explanation that can hold some water is that the aircraft’s  satellite pinger might be floating after the crash and was transmitting the signal although the quality, strength and also the frequency of the signal could be affected after being partly submerged in water.    

Conclusion 


There could and just may be possible that Mrs Latife Dalelah had seen flight MH370.   If that is the case,  the multi-nation search now carrying out in the southern Indian Ocean west of Australiawill be futile and will  turn up no result.

Update 1:  Check the vision of the lady  26 March

 

Someone in a forum suggested that lady's vision should be checked as she was over 50.  This suggestion is reasonable but in the first instance,  someone must accept her story.  BTW,  how much would it cost to send a plane there to check it out?
 
 

Update 2:  How deep is the seamount  26 March

 
The seamount or the mountain under water where the Tomnod maps are located is called the "ninetyyeast ridge" in the eastern Indian Ocean as shown.  It is about 5000 km in length,  stretching from the Andaman islands all the way to Western Australia.  According to this echogram from this article,  the ridge is still very deep,   around 1,500 to 2000 metres.  Therefore,  it is likely that any plane landed there would have sunk after sometime.

 

 

 

 Update3 : Picture from the Plane 28 March

 
A Chinese forumer took a photo of Lanzhou airport from a plane.  He said  he was about 10,000 metres (or about 32,800 feet) high and about 200 km away when he took the following  picture with his  Canon digital camera that  has no focusing function.  The parking planes can be seen roughly. 
 
  

Update 4:  Timing of the sighting - 28 March

 
Mrs Latife Dalelah saw  the plane floating in the water at 2:30 pm Malaysian time and the Malaysian's military radar spotted the plane flying around Andaman sea and disappeared from the limit of its screen around 2:15 am,  about 200 miles North West of Penang.  There is an approximate 10 hours between the two locations.  Although the plane might take another hour to fly to the crash site,  the timing is against  Mrs Latife Dalelah's plane sighting unless the plane could float in the water with air pockets in the fuselage and the wings for about 9 hours.
 
 

Update 5: Can Plane float in the water? - 28 March

 
Plane will eventually sink when landed on water.  The time taken will depend on the condition of the aircraft,  how it is damaged as well as the pressure within the aircraft and whether there are still air pockets large enough to hold up the plane.  In the history of aviation,  most planes landed on water sunk within an hour.  However, on 23 November 1996,  there was an Ethiopian Airlines Flight 961 (a Boeing 767-260ER) floated in the Indian Ocean for some time until the 50 survivors were rescued. 
 
============================================================

Appendix I:  Tomnod maps

1)  Tomnod map 4534 and 5239 


Tomnod map 4534 and 5239 contain some satellite images debris that were suspected to be from MH370.   

5239 appears to show the 2 engines of the Boeing 777

It matches the dimensions of Boeing 777 when a 777 was superimposed as shown in the following picture. 
 
Isn't the engines supposed to have sunk? 

It may be because the plane actually hit the seamount as it crashed (see google earth map)  and the plane did not sink immediately when the satellite image was taken.  The waves or ripples created on top and around the right wing suggested some very big boards as large as a wing of a plane was submerged underneath the water.  Just like what was seen here for this plane

 



Map 4543 which shows some debris that appears to match one of the logo of MAS airline “Malaysia” although many said the fonts were not the same.  It may have been distorted due to the poor resolution of the satellite images 

 


Other debris found around the area   

 

 




 



 

Wednesday, February 12, 2014

Bed Cooler for Ng Teng Fong Hospital

12 February 2013


Introduction

The 700-bed Ng Teng Fong hospital at Jurong East is set to open in December 2013.  It will serve the 900,000-strong residential and business community in the West of Singapore.  It shall have green surroundings and spacious wards with a view of  several rooftop gardens.  However,  what most patients need is also a good rest and a good night sleep for quick recovery in the hospital;  it is always hard to get one in a hot and humid environment like in Singapore.  

Is it acceptable?

The report said that the spacious wards in Ng Teng Fong hospital will have natural ventilation except for those in private wards.  Those who was bedridden before will testify that this is far from acceptable. What about those who are suffering from bed sore?   

What can be done?

One way is to provide air-conditioning for all the wards.  But this will not only make hospital stays  more expensive but also not acceptable because it is unhygienic to share recycled air.   Furthermore,  individual control for air-conditioning is not possible except for the private rooms.  Howvewr, Air conditioners cannot solve bed sore problem unless the heat from the bed can be extracted.   Other methods such as provision of water bed and ripple bed will not help also.   The alternative is to provide bed cooler,  one for each bed.

 

What is a Bed Cooler?

It is a small air conditioning system that will cool only the bed.  It has a cooling  sheet or jacket spreaded between the bed sheet and the bed.  The cooling sheet may have embedded flexible tubes or otherwise that will allow cooled air or chilled water to be circulated to the bed to extract the body heat.  The simple ones used a cooling fan blowing into the cooling sheet;  the more complicated ones use chilled water for cooling.  The latter is preferred because it can provide better and efficient cooling.   

What are the Advantages?

Bed coolers will not only provide affordable cooling,  it is also hygienic as water is used as a media in a closed loop system.  It will work well in natural ventilated wards.  Bed coolers can save up to 90% of the air conditioning bills.  If they are operated together with existing air conditioning,  it can save up to 50% of the energy bills as the temperature of the existing air conditioning can be raised.  The system can be designed to be controlled remotely,  individually and/or centrally  to suit the patients’ cooling requirement.  

Bed sore is one of the biggest problem in hospitals as most hospital use  PVC covered mattresses and pillows for hygienic reason and ease of cleaning.   Patients are often strapped with tubes or illnesses making them difficult to turn their backs and bodies around like ordinary people.    Prolonged staying in the bed in a position will cause bed sores.  Although the nurses can help,  they are often very busy.  Bed coolers can help to solve this bed sore problem,  save labour as well as energy cost.


Why our Hospitals not using them?

It may be because bed cooler is a relatively new concept that has never been used in hospitals.  Many are not sure just how they would fit into the hospital's operation. Bed coolers are quickly perceived to have operational  problem;  for example, how to ensure that the cooling system can be quickly connected and disconnected when the bed is always on the move.  

Bed Cooler,  a Proven System?

Bed coolers are actually nothing new.  They are just miniature size of a chilled water cooling system that has been used in cooling large buildings. They can be part of the existing air conditioning  system with addition of  inexpensive controls and minimum maintenance. 


As for the  quick connection and disconnection of chilled water piping for beds on the move without making a mess on the floor,  there are proven  quick connectors that one can use to ensure safe connection and disconnection without any water spillage or leakage.  Such quick connectors have been used in car racing sports  to fill up the petrol for the racing cars within minutes or seconds.    


Additional Cost

The bed cooler can make use of the existing chillers often installed as a standard in air conditioning buildings.  The additional cost for the new building will not be much;  even for existing buildings,  it would be possible to add bed coolers without additional chillers as the burden of bed coolers  should  be offset by reduced air conditioning load.   The additional cost will therefore be the PVC water jacket which will cost less than $20/= each when purchased in bulk.  There will be additional cost for quick connectors, small pumps, heat exchanger,  tubing and flow controls which a rough estimate indicates that it will not cost more than  $400 per bed including installation. 

 

 

Conclusion

It is good for hospital to have all the features and facilities that are designed for healing but what is the use if the patient cannot get a good rest or a good night sleep in a hot and humid environment of Singapore.  Bed coolers will not only save energy bills, it can also save labour cost and solve bed sore problems.  It is also more hygienic than the ordinary air conditioners.

]
Update :  19 August 2014

Just read  that Tan Tock Seng Hospital had retrofitted their hospital's subsidised  wards with  air conditioning.   This indicates that there are demands even for existing hospital to retrofit its wards for better comfort of the patients.  However,  the air conditioning provision will not be able to solve the bed sore problem because the air conditioning cannot reach the bed and take away the body heat built-ups;  only bed coolers can.   
The retrofitting of the air conditioning to existing building will cost at least 200% more than bed cooler,  requiring extensive retro-fitting work and closure of the wards for some long period.  As for the bed cooler,  one will need only a bottom corner space to run horizontal PVC trunking for piping and controls.,  the installation should take less than a week.

References
Bed Cooler, a Worthwhile investment

tinyurl :  https://tinyurl.com/y8g4c5xu

Thursday, January 30, 2014

What VIX Can Tell Us?

29 Jan 2014

Introduction 


VIX is a volatility index that tracks the trends of the US markets.  It runs inversely proportional to the USindexes.  When VIX goes up,  the general US market indexes like DOW JONE (DJI) ,  S&P500 (SPX) and Nasdaq (IXIC) will trend down and vice versa.   Many investors like to view VIX in daily chart but it would be more meaningful to view VIX in another form.  This article will show how and why. 

Original form


When VIX is shown in its original daily form,  it simply shows the inversion between indexes between say SPX and VIX.  Nothing in the chart can show how one can use VIX to predict  the direction of SPX.




Transformed


If one were to transform VIX by showing only the 20-day,  50-day and 200-day simple averages,  one can use it immediately to show whether it is strong buy or strong sell or just simple buy and sell.





Why?


When VIX is shown in its original form,  the noises of daily movement prevented the trends from revealing.  The average function smoothen out the noises.    One can also use many other similar smoothening technique or technical analysis tools to chart VIX’s direction and predict where the USmarkets will go next.

The Significances


  1. The reversal of VIX’s 20-day will indicate the reversal of SPX.  It will also indicate if it is buy or a sell;
  2. The 200-day will chart the general direction of the SPX.        SPX will trend up when the 200-day trends down. When the 200-day going flat or trending the other direction; be ready to press buttons;
  3. When 20-day or 50-day rebounds from the 200-day,  it could be time for a strong buy or sell;
  4. If there is a cross between 20-day,  50-day and 200-day, it has some special meanings.  When the 20-day or 50-day fluctuates around 200-day, it does indicate some weakness to come in the main indexes.

Where the US Markets are Heading?

The US markets should register a strong buy as it rebounded recently from the 200-day;  however,  the 200-day has been going flat with signs of going up;   therefore,  it should limit the further rise of SPX;  also,  the VIX’s daily closing price is running very close to the red 2-year trendline with no sign of trending down.  
With the 20 and 50-day now turning up,  the SPX will be ready to trend down.  When the 20-day crosses the 200-day and subsequently corrects and rebounds from the 200-day,  be ready for a plunge.

Disclaimer:  Please note that this article concludes its finding from analysing the charts.  As the market sentiments will change and so will be the trading pattern,  it is therefore advisable for traders to consult to seek further technical assistance if they should use these findings.

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