Meghalaya Board of School Education
(MBOSE) first started in 1974, but after 1996, when the University
(NEHU) discontinued the Pre-University Course, it was taken over by the
Board, since then all the financial matters, relating with SSLC and
HSSLC branch were being dealt by the Board itself. Due to the increasing
number of students per year, the work load is also increased. After
1996, the Board is handling all the academic matters related with
framing of syllabus for all the classes, including SSLC and HSSLC.

Computers use this numbering
system for doing its computations. As explained above, it has its own
advantages. The computer follows three steps to complete and arithmetic
operation:

It
converts the numeric data input to its corresponding binary equivalent.

Performs
the desired arithmetic operation in binary.

Converts
the result back to its corresponding decimal equivalent and outputs the result.

When compared with decimal
numbering system, the binary numbering system different in the number of digits
used for a numeric value representation. The decimal system uses then digits,
namely 0 to 9, whereas the binary system uses only tow digits, 0 and 1. Table below
gives the decimal digits and is equivalent binary.

Decimal Number

Binary Equivalent

Decimal Number

Binary Equivalent

0

1

2

3

4

0000

0001

0010

0011

0100

5

6

7

8

9

0101

0110

0111

1000

1001

Table 1.1: Binary equivalent of
decimal numbers

In table 1.1, we have seen the
binary equivalent of decimal numbers. Now the question that arises is how to convert
a decimal number into its binary equivalent and vice versa? To make it more
general, how to convert a number in a particular base to its equivalent in
another base? There are conversion techniques available to accomplish this task.
They are explain in conversion Techniques

When dealing with binary numbers,
two more terms need to be understood. These are MSB (Most Significant Bit) and
LSB (Least Significant Bit). These two bits play a very important role in many
other aspects of computing, such as address calculation and bus optimization. So
how do we define MSB and LSB? MSB can be defined as the digit that occurs at
the left most position in a binary number. Similarly, LSB can be defined as the
digit that occurs at the rightmost position in a binary number. The figure
below shows the MSB and LSB in a binary number

The computer that we know of is
digital device, which means that digital signals are used for the functioning
of the computer. One property of digital signals is that it has discrete level
of voltages. This Property of digital signals proves to be very useful to
represent data in the computer. Why is it so? The answer to this question lies
to the fact that there are many electrical and electronic devices which can be
in any one of their two possible sates. For example, a simple switch can be
either ON or OFF, a bulb or a Ligth Emitting Diode can be glowing or not
glowing et. Therefore, representation of data becomes necessary to understand
how the computer represents data. As we will see shortly, the com0uter use two
values to represent data. These two values are called bits, switch stand for
Binary Digits. They take the values 0 and 1. John von Neumann suggested this
convention. Since there are only two values with which data can be represented
in computer, at the lowest level, two discrete voltage values are used to
represent the bits. Thus, digital signals, with their property mentioned above,
proved to be ideal for computer systems.

Nearly all of our arithmetic
operations are carried out with decimal numbers. The computer on the other hand
does not use this numbering system. As mentioned earlier, the computer does its
computational jobs with binary numbers, which is based on the number 2, for a
number of reasons. The most important of them are the facts that operations
with binary numbers are more precise and also the operations are faster because
of the fact that for certain binary operations, there is hardware circuitry
available.

For common numbering systems are
generally used. They are the decimal numbering system, binary system, octal
numbering system and finally, the hexadecimal numbering system. Decimal numbering
system use base 10 (thus the prefix deci). Binary number system use base 2,
octal numbering system use base 8 and hexadecimal numbering system use base 16.
Thus, they have the prefix bi, octal and hexa respectively. We said that the
numbering system use a base value. What do we understand by a base value? We can
say that the base of a number refers to how many digits are required to
represent a numerical value in that numbering refers to how many digits are
required to represent a numerical value in that numb erring system. Thus,
decimal been base 10, system requires two digits, 0 and 1, to represent any
numerical value. The following sections will describe three common numbering
systems.

Shifting cultivations is still practiced
in North Eastern Hill Region. In this system, crops are generally grown on
a piece of land by the cultivators (jhumias) only once. After crop
harvest, the cultivators (Jhumias) move to a new land, thus left the land
fallow for 10 to 15 years.

But today of rapid increasing in human
population along with decrease in land. Cultivators (Jhumias) should
reduce the shifting cycle leading to destruction of:

Ã˜Forest
wealth

Ã˜Loss
of soil cover

Ã˜Siltation
of reservoirs/ rivers resulting floods in the plains.

Thus
this system of cultivation is now considered to be unscientific.

Shifting cultivation not only losses the
fallow land but also have many unfavourable circumstance disadvantages
which effect the human kind:

Ã˜Environmental
Effect

Ã˜Deforestation

Ã˜Soil
Erosion

Ã˜Loss
of Biodiversity

Ã˜Pollution
of coastal waters

The problem generated from Jhum
Cultivation are:

Ã˜Climate

Ã˜Slash
and Burn

Ã˜Harm
to Indigenous Plants

Ã˜Loss
of habitat for Animals

So,
we need to protect and conserve the natural forest and wild life.

Shifting Cultivation are seen as
tradition- bound by peasant and small farmers, trapped by ignorance and
unable to manage their resources properly.

Ã˜The
current practice of shifting cultivation in Eastern and Northeastern region of
India is an extravagant wasteful of several plot lands and unscientific form of
land use.

Ã˜Its
evil effect are devastating, destructive and far-reaching in degrading
(humiliating) the environment and ecology of the regions.

The earlier 10 to 15 yrs cycle of shifting
cultivation on a particular land has reduced to 2 to 3 yrs now. This has
resulted in

Ã˜Large
Scale Deforestation

Ã˜Soil
and Nutrient Loss

Ã˜Invasion
by weeds and other Species

The
indigenous biodiversity has been affected to a large extent.

The Tripura Forest Minister Jitendra
chowdhury has expressed deep concern over degradation of forest land due
to Jhum Cultivation.

In 1990, studies by the World Bank and the
UN’s Food and Agriculture Organisation blamed Shifting cultivation for the
forest loss due to Shifting Cultivation.

Many NGO’s against for the country’s
devastating fires, to those reckless Shifting cultivators of large-scale
plantation.

Ã˜About
45% of tropical agriculture area in the world is under shifting cultivation.

Ã˜One
third (1/3) of agriculture in South East Asia constitutes in Shifting
Cultivation.

Ã˜60%
of Africa’s food is also produced through Shifting Cultivation.

Ã˜The
actual area affected by Shifting Cultivation was highest in Manipur at 77.4%

Ã˜Arunachal
12.4%

Ã˜Assam
rank Fifth (5^{th}) with 74.1%

It was not only economically unviable in present world but also a
major threat to the biodiversity and contributor to Shifting Cultivation which
lead to deforestation.

Therefore we should put an end to shifting cultivation for a better
environment.