মনে থাকে না শব্দটা ছা্ত্রজীবনে বেশ পরিচিত । পড়তে পড়তে ক্লান্ত হয়ে পড়লেও
পরীক্ষার হলে ডুকলেই যেন সব ভুলে যাওয়াই কমন! আমরা সব কিছু চাইলেও বাস্তবে
সেটা সম্ভব নয়। কিন্তু মনে রাখার পরিমাণ বাড়ানো সম্ভব। এজন্য আপনাকে কিছু
নিয়ম কানুন মানতে হবে।
১. কোনো কিছুকে গুরুত্ব দিয়ে না শুনলে কিংবা না দেখলে তা আপনার মনে
থাকবে না। সুতরাং নিজেকে বিষয়টি সম্পর্কে সজাগ এবং সচেতন রেখে গুরুত্ব
সহকারে মনোযোগ রাখেন। এই মাত্র যার সঙ্গে আপনার পরিচয় হলো তার নামটি যদি
আপনি মনে রাখতে চান তাহলে কয়েকবার নিজে নিজে বলুন । ডাইরিতে লিখে নিলে তা
মনে থাকে ভাল।
২. স্বভাবের দিক দিয়ে গোছানো হলে অনেক কিছু সহজে মনে থাকে।
নিত্যপ্রয়োজনীয় জিনিসগুলো নির্দিষ্ট জায়গায় রাখলে প্রয়োজনের সময় হাত
বাড়াতে পাবেন সহজে।এতে করে নিজের প্রতি নিজের বিরক্তি আসবে না,যেটি আপনার
স্মৃতি বৃদ্ধিতে সহায়ক।কেননা নিজের প্রতি বিরক্তি আসলে অনেক সহজ জিনিস ভুলে
যাবেন অতি সহজেই।
৩. দিন তারিখ মনে রাখার জন্য আমরা ক্যালেন্ডার, ঘড়ি ব্যবহার করছি। ঘুম
থেকে ওঠার জন্য এলার্ম ঘড়ি ব্যবহার করছি। আজকাল মোবাইল ফোন এবং অন্যান্য
ইলেক্ট্রনিক যন্ত্রে রিমাইন্ডার নামে একটা ব্যবস্থা আছে। যা আপনাকে কাজের
কথাটা মনে করিয়ে দেবে। যে জিনিসটা নিয়ে বাইরে যেতে হবে তা দরজার মুখে
রাখুন, ওষুধটা বেসিনের উপরে তাকে রাখুন। প্রয়োজনের জিনিস গুলো আগে গুছিয়ে
রাখুন, কোন জিনিস ফেলে যাওয়ার সম্ভাবনা থাকবে না।
৪. শরীর সুস্থ থাকলে মন সুস্থ থাকে। তাই নিয়মিত ব্যায়াম করুন, পরিমান মত
আহার করুন, সিগারেট থেকে বিরত থাকুন। কানে শুনতে, চোখে দেখতে অসুবিধা
থাকলে ডাক্তার দেখিয়ে প্রয়োজনীয় ব্যবস্থা নিবেন, এতে অন্য জন কি বলছে কি
করছে আপনি আর মিস করবেন না। ঘুমের বড়ি না খাওয়া ভাল। আপনি আরো বেশি
এ্যালার্ট থাকবেন তাহলে।
৫. নিয়মিত স্বাস্থ্য পরীক্ষা করানোর ব্যাপারটা আমাদের অভ্যাসের বাইরে।
ফলে রোগ গভীর না হওয়া পর্যন্ত আমরা তার উপস্থিতি টের পাই না। প্রত্যেকের
উচিত প্রতি বছর ডাক্তারকে দিয়ে স্বাস্থ্য পরীক্ষা করানো। এতে উচ্চ রক্তচাপ,
ডায়াবেটিস, চোখের এবং কানের সমস্যা সহজে ধরা পরবে।
৬. শারীরিক কাজ না করলে শরীর দুর্বল হয়ে যায়। কেউ যদি কয়েক সপ্তাহ
বিছানায় শুধু শুয়ে থাকে তার পা সরু হয়ে যাবে, মাংস পেশীতে টান পড়বে, হাঁটতে
অসুবিধা হবে। তেমনি কার্য ক্ষমতা কমে যায়। সুশিক্ষিত বুদ্ধিমান ব্যক্তি
যারা নিয়মিত বুদ্ধির চর্চা করেন বয়সের সঙ্গে সঙ্গে তাঁদের স্মৃতি হ্রাস
তুলনা মূলক ভাবে কম হয়। তাই ভাল স্মৃতিশক্তি পেতে চাইলে নিয়মিত পড়ুন, শিখুন
ও সমস্যা সমাধানে অংশগ্রহণ করুন। অলস ভাবে বসে থাকলে স্মৃতিশক্তি কখনও
বাড়বে না।
৭. মনে রাখার কিছু চমৎকার কৌশল আছে। ইংরেজিতে লেফটেন্যান্ট বানানটা মনে
রাখা আপনার জন্য খুব কষ্টকর হলে মনে রাখুন। মিথ্যা তুমি দশ পিঁপড়া শব্দ
গুলোর ইংরেজি লিখে নেন। বানান পেয়ে গেলেন, মনে রাখার জন্য কল্পনা শক্তির
ব্যবহার খুব জরুরি। যে কল্পনা শক্তিকে যত চমৎকার ভাবে ব্যবহার করতে পারবে
তার মনে থাকবে তত বেশি।অথবা আপনার কাছে যে জিনিস গুলো মনে রাখা কষ্টকর হয়ে
দাঁড়ায় সেগুলো আপনার প্রিয় জিনিসের সাথে তুলনা করে মনে রাখার চেষ্টা করুন।
৮.অধিকাংশ মানুষ যারা নিজেদের স্মরণশক্তি নিয়ে দুশ্চিন্তা গ্রস্ত নন
তারা সব কিছু মনে রাখতে পারে তা নয়। যুবকদের মধ্যে যারা ভুলে যায় তারা হয়ত
অজুহাত দেখায়। প্রেমে পরেছি মন অন্য দিকে নেই। পড়াশোনা নিয়ে খুব ব্যাস্ত
ইত্যাদি ইত্যাদি। বয়স্করা ভাবেন আমার কি স্মৃতিভ্রংশ দেখা দিল? আসলে এরা
সবাই স্বাভাবিক। মানুষ একটু আধটু ভুলবে। যতক্ষণ পর্যন্ত এটা সাধারণ
কাজকর্মে ব্যাঘাত না ঘটাচ্ছে ততক্ষণ দুশ্চিন্তার কিছু নেই।সত্যি যদি মনে
ভুলে যাওয়া ব্যাপারটা আপনাকে বেশ ভোগায় তাহলে ডাক্তারের পরামর্শ নিন। সে
ক্ষেত্রে যত দ্রুত চিকিৎসা শুরু করবেন তত ভাল।
ICT
is the backbone of any digital initiative. ICT covers the vast area of
information technology, communication technology and the
telecommunication technology. ICT is also a combination of physical
backbone and intellect. Computer systems, network machineries, software,
wire and wireless connectivity systems, broadcast hardware and many
other hardware and accessories are the physical backbone. The trained
human behind the backbone are the intellect. Digital Bangladesh is an
Idea that includes the IT use for management, administration and
governance to ensure transparency, accountability and answerability at
all levels of society and state. To materialize the idea of digital
Bangladesh, development of countrywide backbone and expected number of
human recourses are the basic needs.
Despite having 50 years of
history the government has only from 1997 started the process of
developing a national ICT strategy. In 2002 Bangladesh identified ICT as
a "thrust sector" as it represents potential for quick wins in reforms,
job creation, industry growth, improving governance and facilitating
inclusion, and it has high spillover effects to other sectors. Today, in
Bangladesh, the overall IT sector (excluding telecoms) is small, valued
at $300 million, with IT/ITES claiming 39% ($117 million) of that
value. The overall IT/ITES industry has enjoyed a high growth rate of
40% over the last five (5) years and this trend is expected to continue.
Technology also contributes to
growth by increasing competition. It is estimated that in the US, online goods
are on average 10% cheaper than those sold by traditional bricks and mortar
stores. This is partly because of increased price transparency and the ability
of consumers to use online price comparison tools to find the cheapest
products. Secondly the Internet e-commerce platforms, most famously Amazon,
offer massive economies of scale.
Ebay auction sites were also a
disruptive technology in retailing space by making the sale of used products
and new goods much easier, again putting downwards pressure on prices.
So Internet markets are argued to be
more efficient due to the ease of information transmission, which leads to
lower transaction costs. Different pricing and selling mechanisms, such as
online auctions, also contribute to increased efficiency.
We have already seen a rapid growth
of e-commerce in Bangladesh with the Digital Bangladesh initiative continuing
to encourage the expansion of this sector. Recent initiatives by Bangladesh
Bank to allow e-payment facilities online, using credit cards such as by enabling
Paypal in Bangladesh, will help the growth of the sector even further. In a
country like Bangladesh, where supply chains are not that efficient, ICT will
reduce the scope for price distortions and manipulation by unscrupulous
middlemen to ensure that consumers receive fair prices.
To the extent that we accept that
the effective utilisation of technology can have a transformative impact on the
economy, it is important to determine what steps policymakers should take in
Bangladesh. Firstly, they should ensure world class digital infrastructure and
networks at competitive prices. In this area, the Bangladesh government has
made major progress in recent years with the dramatic fall in broadband prices,
the rapid rollout of 3G services, and the prospects for fast introduction in
the near future of 4G and LTE.
Secondly, the government can
encourage the development of a strong local IT ecosystem. Thirdly, expanding
the IT skills base is critical with more vocational colleges to increase the
supply of programmers and IT management and marketing professionals. Effective
use of ICT can also play a key role in female empowerment by bringing more
women into the workplace and allowing them greater flexibility in working from
home/working hours that enables greater balance with family commitments.
It is also important that the
government ensures a stable and supportive regulatory framework both in terms
of avoiding regulatory volatility and inconsistent or negative taxation
policies for the IT sector.
The government has committed to
establishing 12 new technology parks in Bangladesh, with the first being the
238 acre park in Kaliakoir near Dhaka. But there are some other encouraging
initiatives from the private sector in the pipeline. Sajeeb Wazeb Joy, ICT
Advisor to the Prime Minister, noted in his speech at the Digital World 2015
that: “One of the problems is financing. In America, new innovations don’t get
support from the government. They get their funding from the private sector.”
In this context, the announcement in
November that Fenox, a Silicon Valley venture capital firm, was raising a $200m
fund for Bangladesh IT, is especially encouraging. Kyle King from Fenox noted:
“Bangladesh has a large, young
population, an outstanding Internet and mobile growth with an unexplored
entrepreneurial system which all make Bangladesh a place for innovation,
discovery, change, disruption, creation, and investment … For Fenox, Bangladesh
qualifies as the right country to be a part of in terms of developing the
world’s most influential startups.”
Sajeeb Wazed Joy also stated: “I
want companies like Google and Facebook to emerge from Bangladesh.”
On the face that may sound like
wishful thinking. But in fact technology is levelling the competitive playing
field so fast that in our generation it is definitely conceivable, perhaps even
likely, that a boy from a Bangladeshi village has the potential to create a
company with a disruptive technology as powerful as Google or Facebook.
To paraphrase NY Times columnist
Thomas Friedman. Technology is the primary driver of such “flattening” of the
global economic landscape.
In conclusion, we believe that ICT is every bit
as important as energy and infrastructure investment in raising the trend
growth rate. Effective implementation of Digital Bangladesh may yet prove to be
the single most important weapon in poverty alleviation allowing Bangladesh to
achieve its potential as the fastest growing economy in Asia
Digital
World 2015, the recently concluded four-day conference, was the fourth
largest ICT event in the world, with 120 private companies and 100
governmental organisations from 25 countries. It also featured
representatives from leading technology companies, most notably Google,
which sent a broad range of executives, as well as Facebook and
Microsoft, among others.
While the primary focus of the event was to highlight the advances of
the “Digital Bangladesh” initiative of the current government as well
as potential growth opportunities in the ICT sector, in this long form
we want to discuss some of the broader potentials of technology as a
catalyst for economic growth
- See more at: http://www.dhakatribune.com/long-form/2015/feb/25/digital-bangladesh-engine-economic-growth#sthash.1EyFe3OG.dpuf
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Can tech powerhouses emerge from Bangladesh?
Digital
Bangladesh as an engine for economic growth - See more at:
http://www.dhakatribune.com/long-form/2015/feb/25/digital-bangladesh-engine-economic-growth#sthash.1EyFe3OG.dpuf
Digital
Bangladesh as an engine for economic growth - See more at:
http://www.dhakatribune.com/long-form/2015/feb/25/digital-bangladesh-engine-economic-growth#sthash.1EyFe3OG.dpuf
Power transformer, 120VAC step-down to 12VAC, with center-tapped
secondary winding (Radio Shack catalog # 273-1365, 273-1352, or
273-1511).
Terminal strip with at least three terminals.
Household wall-socket power plug and cord.
Line cord switch.
Box (optional).
Fuse and fuse holder (optional).
Power transformers may be obtained from old radios, which can usually be
obtained from a thrift store for a few dollars (or less!). The radio
would also provide the power cord and plug necessary for this project.
Line cord switches may be obtained from a hardware store. If you want to
be absolutely sure what kind of transformer you're getting, though, you
should purchase one from an electronics supply store.
If you decide to equip your power supply with a fuse, be sure to get a slow-acting, or slow-blow
fuse. Transformers may draw high "surge" currents when initially
connected to an AC source, and these transient currents will blow a
fast-acting fuse. Determine the proper current rating of the fuse by
dividing the transformer's "VA" rating by 120 volts: in other words,
calculate the full allowable primary winding current and size the fuse
accordingly.
CROSS-REFERENCES Lessons In Electric Circuits, Volume 2, chapter 1: "Basic AC Theory"
Lessons In Electric Circuits, Volume 2, chapter 9: "Transformers"
LEARNING OBJECTIVES
Transformer voltage step-down behavior.
Purpose of tapped windings.
Safe wiring techniques for power cords.
SCHEMATIC DIAGRAM
ILLUSTRATION
INSTRUCTIONS Warning!This project involves the use of dangerous voltages.
You must make sure all high-voltage (120 volt household power)
conductors are safely insulated from accidental contact. No bare wires
should be seen anywhere on the "primary" side of the transformer
circuit. Be sure to solder all wire connections so that they're
secure, and use real electrical tape (not duct tape, scotch tape,
packing tape, or any other kind!) to insulate your soldered connections.
If you wish to enclose the transformer inside of a box, you may use an
electrical "junction" box, obtained from a hardware store or electrical
supply house. If the enclosure used is metal rather than plastic, a
three-prong plug should be used, with the "ground" prong (the longest
one on the plug) connected directly to the metal case for maximum
safety.
Before plugging the plug into a wall socket, do a safety check
with an ohmmeter. With the line switch in the "on" position, measure
resistance between either plug prong and the transformer case. There
should be infinite (maximum) resistance. If the meter registers
continuity (some resistance value less than infinity), then you have a
"short" between one of the power conductors and the case, which is
dangerous!
Next, check the transformer windings themselves for continuity. With the
line switch in the "on" position, there should be a small amount of
resistance between the two plug prongs. When the switch is turned "off,"
the resistance indication should increase to infinity (open circuit --
no continuity). Measure resistance between pairs of wires on the
secondary side. These secondary windings should register much lower
resistances than the primary. Why is this?
Plug the cord into a wall socket and turn the switch on. You should be
able to measure AC voltage at the secondary side of the transformer,
between pairs of terminals. Between two of these terminals, you should
measure about 12 volts. Between either of these two terminals and the
third terminal, you should measure half that. This third wire is the
"center-tap" wire of the secondary winding.
It would be advisable to keep this project assembled for use in powering
other experiments shown in this book. From here on, I will designate
this "low-voltage AC power supply" using this illustration:
COMPUTER SIMULATION Schematic with SPICE node numbers:
Netlist (make a text file containing the following text, verbatim): transformer with center-tap secondary v1 1 0 ac 120 sin rbogus1 1 2 1e-3 l1 2 0 10 l2 5 4 0.025 l3 4 3 0.025 k1 l1 l2 0.999 k2 l2 l3 0.999 k3 l1 l3 0.999 rbogus2 3 0 1e12 rload1 5 4 1k rload2 4 3 1k
* Sets up AC analysis at 60 Hz: .ac lin 1 60 60
* Prints primary voltage between nodes 2 and 0: .print ac v(2,0)
* Prints (top) secondary voltage between nodes 5 and 4: .print ac v(5,4)
* Prints (bottom) secondary voltage between nodes 4 and 3: .print ac v(4,3)
* Prints (total) secondary voltage between nodes 5 and 3: .print ac v(5,3) .end
Two "banana" jack style binding posts, or other terminal hardware,
for connection to potentiometer circuit (Radio Shack catalog # 274-662
or equivalent)
Plastic or metal mounting box
Regarding the headphones, the higher the "sensitivity" rating in
decibels (dB), the better, but listening is believing: if you're serious
about building a detector with maximum sensitivity for small electrical
signals, you should try a few different headphone models at a
high-quality audio store and "listen" for which ones produce an audible
sound for the lowest volume setting on a radio or CD player.
Beware, as you could spend hundreds of dollars on a pair of headphones
to get the absolute best sensitivity! Take heart, though: I've used an old pair of Radio Shack "Realistic" brand headphones with perfectly adequate results, so you don't need to buy the best.
Normally, the transformer used in this type of application (audio
speaker impedance matching) is called an "audio transformer," with its
primary and secondary windings represented by impedance values (1000 Ω :
8 Ω) instead of voltages. An audio transformer will work, but I've
found small step-down power transformers of 120/6 volt ratio to be
perfectly adequate for the task, cheaper (especially when taken from an
old thrift-store alarm clock radio), and far more rugged.
The tolerance (precision) rating for the 1 kΩ resistor is irrelevant.
The 100 kΩ potentiometer is a recommended option for incorporation into
this project, as it gives the user control over the loudness for any
given signal. Even though an audio-taper potentiometer would be appropriate for this application, it is not necessary. A linear-taper potentiometer works quite well.
CROSS-REFERENCES Lessons In Electric Circuits, Volume 1, chapter 8: "DC Metering Circuits"
Lessons In Electric Circuits, Volume 2, chapter 9: "Transformers"
Lessons In Electric Circuits, Volume 2, chapter 12: "AC Metering Circuits"
LEARNING OBJECTIVES
Soldering practice
Use of a transformer for impedance matching
Detection of extremely small electrical signals
Using diodes to "clip" voltage at some maximum level
SCHEMATIC DIAGRAM
ILLUSTRATION
INSTRUCTIONS
This experiment is identical in construction to the "Sensitive Voltage
Detector" described in the DC experiments chapter. If you've already
built this detector, you may skip this experiment.
The headphones, most likely being stereo units (separate left and right
speakers) will have a three-contact plug. You will be connecting to
only two of those three contact points. If you only have a "mono"
headphone set with a two-contact plug, just connect to those two contact
points. You may either connect the two stereo speakers in series or in
parallel. I've found the series connection to work best, that is, to
produce the most sound from a small signal:
Solder all wire connections well. This detector system is extremely
sensitive, and any loose wire connections in the circuit will add
unwanted noise to the sounds produced by the measured voltage signal.
The two diodes connected in parallel with the transformer's primary
winding, along with the series-connected 1 kΩ resistor, work together to
"clip" the input voltage to a maximum of about 0.7 volts. This does
one thing and one thing only: limit the amount of sound the headphones
can produce. The system will work without the diodes and resistor in
place, but there will be no limit to sound volume in the circuit, and
the resulting sound caused by accidentally connecting the test leads
across a substantial voltage source (like a battery) can be deafening!
Binding posts provide points of connection for a pair of test probes
with banana-style plugs, once the detector components are mounted inside
a box. You may use ordinary multimeter probes, or make your own probes
with alligator clips at the ends for secure connection to a circuit.
Detectors are intended to be used for balancing bridge measurement
circuits, potentiometric (null-balance) voltmeter circuits, and detect
extremely low-amplitude AC ("alternating current") signals in the audio
frequency range. It is a valuable piece of test equipment, especially
for the low-budget experimenter without an oscilloscope. It is also
valuable in that it allows you to use a different bodily sense in
interpreting the behavior of a circuit.
For connection across any non-trivial source of voltage (1 volt and
greater), the detector's extremely high sensitivity should be
attenuated. This may be accomplished by connecting a voltage divider to
the "front" of the circuit:
SCHEMATIC DIAGRAM
ILLUSTRATION
Adjust the 100 kΩ voltage divider potentiometer to about mid-range when
initially sensing a voltage signal of unknown magnitude. If the sound
is too loud, turn the potentiometer down and try again. If too soft,
turn it up and try again. This detector even senses DC and
radio-frequency signals (frequencies below and above the audio range,
respectively), a "click" being heard whenever the test leads make or
break contact with the source under test. With my cheap headphones,
I've been able to detect currents of less than 1/10 of a microamp (<
0.1 µA) DC, and similarly low-magnitude RF signals up to 2 MHz.
A good demonstration of the detector's sensitivity is to touch both test
leads to the end of your tongue, with the sensitivity adjustment set to
maximum. The voltage produced by metal-to-electrolyte contact (called galvanic voltage)
is very small, but enough to produce soft "clicking" sounds every time
the leads make and break contact on the wet skin of your tongue.
Try unplugging the headphone plug from the jack (receptacle) and
similarly touching it to the end of your tongue. You should still hear
soft clicking sounds, but they will be much smaller in amplitude.
Headphone speakers are "low impedance" devices: they require low voltage
and "high" current to deliver substantial sound power. Impedance is a
measure of opposition to any and all forms of electric current,
including alternating current (AC). Resistance, by comparison, is a
strictly measure of opposition to direct current (DC). Like
resistance, impedance is measured in the unit of the Ohm (Ω), but it is
symbolized in equations by the capital letter "Z" rather than the
capital letter "R". We use the term "impedance" to describe the
headphone's opposition to current because it is primarily AC signals
that headphones are normally subjected to, not DC.
Most small signal sources have high internal impedances, some much
higher than the nominal 8 Ω of the headphone speakers. This is a
technical way of saying that they are incapable of supplying substantial
amounts of current. As the Maximum Power Transfer Theorem predicts,
maximum sound power will be delivered by the headphone speakers when
their impedance is "matched" to the impedance of the voltage source.
The transformer does this. The transformer also helps aid the detection
of small DC signals by producing inductive "kickback" every time the
test lead circuit is broken, thus "amplifying" the signal by
magnetically storing up electrical energy and suddenly releasing it to
the headphone speakers.
As with the low-voltage AC power supply experiment, I recommend building
this detector in a permanent fashion (mounting all components inside of
a box, and providing nice test lead wires) so it can be easily used in
the future. Constructed as such, it might look something like this:
2.Place a small hole near the core, and put the end of some thin wire through it.
Next:
3.Wind required number of turns evenly.
Next:
4. Place a small hole and put the other end of the wire through this hole.
Next:
5.Put some insulation tape over the windings.
Next:
6.For a step down transformer, repeat steps 2 to 5 using thicker wire.
Next:
7.Put an iron or ferrite core through the middle if
required (best if the ends of the core can be connected using the same
core material on the outside of the windings).
দুনিয়ার সবচেয়ে সুন্দর পুরুষ, মহিলার ছবি তৈরি করল কম্পিউটার
ছবিটি নেওয়া হয়েছে ফেসবুক থেকে। (কল্পিত ছবি)
ওয়েব
ডেস্ক: দুনিয়ার সবচেয়ে সুন্দর পুরুষ ও মহিলার নাম কী? জানি এই প্রশ্নটা
করলে তর্ক বাধবেই। এই বিষয়ে আপনার সঙ্গে আমার, আবার আপনার বন্ধুর সঙ্গে
আপনার কিংবা আমার মতের অমিল হতে বাধ্য। কিন্তু দুনিয়ার সবচেয়ে সুন্দর
পুরুষ, মহিলা যদি কম্পিউটার নিজেই তৈরি করে! হ্যাঁ এমনই ছবি তৈরি করল এক
সফটওয়ার। যা দিয়ে অপরাধীদের ধরা হয়ে থাকে, সেই সফটওয়ার দিয়ে তৈরি করা হল
দুনিয়ার সবচেয়ে সুন্দর পুরুষ ও মহিলার ছবি।
ব্রিটেনের শতাধিক মানুষকে জিজ্ঞাসা করা হয়েছিল সবচেয়ে সুন্দর মানুষের
ছবি তৈরি করা হলে তারা কেমন দেখতে হবে। চোখ, ঠোঁটের গড়ন, ভ্রু থেকে নাকের
আকৃতি, চুল সৌন্দর্যের মত সৌন্দর্যের সব আপাত বিষয় নিয়েই করা হয়েছিল
সমীক্ষা। সেই সমীক্ষার ফলাফলকে সফটওয়ারে ফেলে কম্পিউটারে তৈরি হয় দুনিয়ার
সবচেয়ে সুন্দর পুরুষ ও মহিলার ছবি। বলাই বাহুল্য আমেরিকা, ভারত কিংবা
দুনিয়ার বিভিন্ন দেশের মানুষকে একই প্রশ্ন করা হলে 'দুনিয়ার সবচেয়ে সুন্দর
পুরুষ ও মহিলা'র ছবি কম্পিউটার অন্য রকম তৈরি করত।
সুন্দর পুরুষের ছবিতে ইংল্যান্ডের প্রাক্তন তারকা ফুটবলার ডেভিড বেকহামের
সঙ্গে মিল অনেক। সমীক্ষা থেকে উঠে আসা সুন্দর পুরুষের ঠোঁট, নাক, চোখ,
ভ্রু, মুখমণ্ডল তৈরির ক্ষেত্রে বেকহ্যামের কথাই সংখ্যাগরিষ্ঠ মানুষ
বলেছিলেন। আবার সুন্দর মহিলার ছবিতে স্কারলেট জনসন, জেনিফার লরেন্সের বেশ
কিছুটা মিল রয়েছে।
Are we close to making human ‘mind control’ a reality?
With one tap on his space bar, Andrea Stocco fires the cannon on his computer game and blows a rocket out of the sky.
What is remarkable is the way it is being played because the University of Washington researcher can't actually see it.
The person who can, fellow scientist Rajesh Rao, is sitting across campus looking at the screen.
He
is wearing a cap with wires coming out of it (which looks like
something you might have seen in a 1950s sci-fi programme that was
imagining this moment).
Without moving a muscle, or using a communication device, Mr Rao told his colleague to fire the cannon at just the right moment.
The only thing Mr Rao had was the power of his mind, so, at the right moment, he imagined firing the cannon.
This
sent a signal via the internet to Mr Stocco, who, wearing
noise-cancelling earphones (and a purple swimming cap) involuntarily
moved his right index finger to push the space bar.
Imperius curse
What has just happened seems to be the first documented case of human-to-human "mind control".
The researchers gave it the rather less alluring title of human-to-human brain interface, but that's scientists for you.
Until now this concept remained in the realms of theory, or more likely science fiction and fantasy.
Those
of a wizarding persuasion will see parallels with the evil Voldemort's
Imperius curse, used to manipulate people in the Harry Potter stories.
Mr Stocco jokingly refers to the experiment as a
"Vulcan mind meld", after a technique employed by Mr Spock in Star Trek
to share thoughts.
"The internet was a way to connect computers, and now it can be a way to connect brains," Mr Stocco says.
He compares the feeling of his hand moving to that of a nervous tic.
Mr
Rao says it was "both exciting and eerie" to watch an imagined action
from his brain get translated into actual action by another brain.
"The next step is having a more equitable two-way conversation directly between the two brains," he adds.
Brain activity
There are already numerous examples of the human brain being used to control technology.
For example, Samsung is experimenting with a mind-control tablet.
Technology
firm Interaxon is marketing a "brain sensing headband" that it hopes
will allow people to control devices with their minds.
It is already widely used to help those with physical disabilities.
Indeed the technology for recording and stimulating the two researchers' brains in this experiment are both well-known.
Brain signals from the "Sender" are
recorded. When the computer detects imagined hand movements, a "fire"
command is transmitted over the internet, causing an upward movement of
the hand of the "Receiver"
Electroencephalography - the technique used to send the message from
Mr Rao - is routinely used by the medical profession to record brain
activity from the scalp.
Transcranial magnetic stimulation -
which made Mr Stocco's finger move - is a way of delivering stimulation
to the brain to prompt a response.
But putting the two together, effectively allowing one person to direct the responses of another, is new.
'Trivial'
The researchers are quick to point out that this experiment is very basic in terms of the concept.
But
Daniel Wilson, who has a PhD in robotics and is the author of
Robopocalypse, says it remains important as a "proof of concept"
experiment.
"It has sparked a discussion of how brain-to-brain interfaces might impact society in the future," he says.
"Although the experimental set-up is too narrow to have practical value, it certainly makes us think."
However, others are unimpressed.
Dr
Ian Pearson, a futurologist with a background in science and
engineering, compares it to experiments by Australian performance artist
Stelarc 15 years ago.
He enabled people to remote control his limbs via the internet.
"Adding a simple thought recognition control system is pretty trivial," Dr Pearson says.
"If they were taking a thought from one person and directly creating a thought in another then I'd be impressed."
Collaboration
There
is more general agreement on the impact that future developments in
this field could have on the way humans collaborate and communicate.
Mr
Stocco says that one day it could be used to enable someone on the
ground to help a passenger land an aeroplane if the pilot becomes
incapacitated.
Electroencephalography - the technique used to send the message from
Mr Rao - is routinely used by the medical profession to record brain
activity from the scalp.
Transcranial magnetic stimulation -
which made Mr Stocco's finger move - is a way of delivering stimulation
to the brain to prompt a response.
But putting the two together, effectively allowing one person to direct the responses of another, is new.
'Trivial'
The researchers are quick to point out that this experiment is very basic in terms of the concept.
But
Daniel Wilson, who has a PhD in robotics and is the author of
Robopocalypse, says it remains important as a "proof of concept"
experiment.
"It has sparked a discussion of how brain-to-brain interfaces might impact society in the future," he says.
"Although the experimental set-up is too narrow to have practical value, it certainly makes us think."
However, others are unimpressed.
Dr
Ian Pearson, a futurologist with a background in science and
engineering, compares it to experiments by Australian performance artist
Stelarc 15 years ago.Dr Pearson believes these techniques will be used in the future by teams carrying out complex tasks
He enabled people to remote control his limbs via the internet.
"Adding a simple thought recognition control system is pretty trivial," Dr Pearson says.
"If they were taking a thought from one person and directly creating a thought in another then I'd be impressed."
