Some Points to be Remembered in Life

I have just learnt some important things (though we all know these from childhood but we should try to keep in mind these things always):

• Wisdom is more important than wealth
• The biggest weakness is being afraid without any reason
• Don’t make friendship with fools as they could make harm to you
• Don’t make friendship with misers as they would leave you when you need them
• Don’t believe liars as they would show you dreams and then leave you without fulfilling them
• Keep away from backbiters as they would also backbite about you
• Avoid jealousy, arrogance and greed

We are human beings and we may have many character defects. It’s up to us to decide if we want to be good and improve our character power. You just need to be committed to improve yourself, that’s it! Good intentions will attract good things in your life! 

Beautiful Comilla

Some pictures from my visit to Comilla. These are from 2011 to 2016.

How to Make 'Payesh' in an Easy Way

The dessert 'Payesh' is delicious to eat. I like it so much. Here is an easy recipe to make it.

Ingredients:

• 1 liter milk
•  Powdered milk
•  Polao rice
•  Sugar

Recipe:

• Heat 1 liter of milk over mild heat for about 40 minutes. (Pay attention whether the milk overflows. Stir to break up the foam as it forms).
• Mix a cup of water with 2 spoons of powdered milk and pour it into the liquid milk which is still heating and let the mixture be heated for another 20 minutes. (By this time – it can be said after total 50 minutes – wash 2 handful ‘Polao rice’ and soak it in enough water for about 10 minutes).
• After 20 minutes (it has been now 60 minutes total), drain the rice and add it to the milk. Keep stirring to avoid sticking of rice. Let it be cooked for about 20 minutes now.
• Add sugar as per your taste, stir and cook for another 10 minutes so that the milk thickens.
• All these take total 90 minutes and now turn off the flame.
• Let this be cooled and the milk would be thicker. Your ‘Payesh’ is ready to eat.

A Collection of Some Quotes

Quotes may have a good influence in life. Some quotes make us more positive about life when some help to see life from different perspective. They also have the power to revitalize our lives.

I would like to include something from the movie “Three Idiots” –

Rancho: That day I understood that this heart scares easily. You have to trick it, however big the problem is, tell your heart, 'Pal, all is well. All is well.'

Raju: Does that solve the problem?

Rancho: No, but you gain courage to face it.

So, going through positive or inspirational quotes cannot solve anything but these will give us strength to face everything.

These quotes are collected from different books, movies, facebook pages, famous people etc. Here are some of them:

1.      Shift your focus from source of pain to what is desired

2.      All our problems have a solution and problems are not stop signs, they are guidelines

3.      All that we need come to us at the right time and place in life

4.      Don’t compare or compete with others. Compete with yourself

5.      Believe in yourself. Have faith in your abilities

6.      We are not given a good or bad life. We are given a life. It’s up to us to make it good

7.      Don’t waste your time on searching for happiness. Just enjoy what you have

8.      Focus on present. Life is the moment we are living right now

9.      Anyone who interferes with the destiny of others never will discover his own

10.  Look on bright side of things

11.  Do whatever needs to be done, even when you don’t feel like doing it

12.  Pretend like a winner. Life is a stage and you are an actor playing a role. Play the part well and you will become what you pretend to be

13.  Destroy fear because this is your creation

14.  Sometimes the bad things that happen in our lives put us directly on the path to the best things that will ever happen to us  

15.  The night is darkest just before the dawn; the dawn is coming

16.  Why do we fall? So that we can learn to pick ourselves up

17.  It’s not who you are underneath, but what you do that defines you

18.  Life is 10% what happens to you and 90% how you react to it

19.  Keep your eyes on the stars and your feet on the ground

20.  You are never too old to set another goal or to dream a new dream

21.  Don’t count the days, make the days count

22.  Men succeed when they realize that their failures are the preparation for their victories

23.  Our soul desires to be understood; our ego is only concerned with being understood. When you are being understood, you are connected to your soul

24.  Everything will be okay in the end. It it’s not okay, then it’s not the end

25.  Joy is a decision, a really brave one, about how you are going to respond to life

26.  If you really want to do something, you will find a way. If you don’t, you will find an excuse

27.  We cannot solve our problems with the same level of thinking that created them

28.  Courage doesn’t always roar. Sometimes it is the little voice at the end of the day that says - I’ll try again tomorrow

29.  A final forming of a person’s character lies in their own hands

30.  Peace cannot be kept by force, it can only be achieved by understanding

Elementary Ideas About Factorial Design

Engineering experiments often involve several factors and the job of an experimenter is to determine the influence of these factors on the output response of the system. Factorial experiment is an experimental strategy where factors are varied together instead of one at a time. In this article, I will just try to focus on some ideas about factorial design.

Let’s begin with some useful terms which are used in factorial design:

   
   factorial design: Two factors, each at two levels;  or 4 runs (here runs indicate total observations).
  factorial design: Three factors, each at two levels; or 8 runs.

     Main effects: Individual effects of each factor.
     
     Interaction effects: Effects when the factors interact with each other.

     Replication: Repetition of the basic experiment. Suppose, four batteries are tested at each of three levels of temperature; so four replicates.  (We can say it also sample size; in this example, sample size is 4).

     Blocking: Blocking is used to reduce the variability from factors that may influence response but in which we are not directly interested. Suppose, batches of raw materials could be different due to supplier to supplier variability and we are not interested in this effect. So each batch of raw materials (considered as nuisance factors) would form a block.

     Analysis of Covariance: Blocking is used for controllable nuisance factors, but if the factors are uncontrollable then a procedure called analysis of covariance is used. If humidity cannot be controlled in any environment, it can be treated as covariate.

    Operating characteristic curve: This is used for selecting an appropriate sample size.

    Tukey’s test: This is used to test if two means are significantly different and thus all pair wise means are compared.

    Fisher LSD method: This is also used to compare means.

    Analysis of variance (ANOVA) table: Here sum of squares, degrees of freedom, mean square, test statistic for hypothesis are shown.

    Treatments: Different levels of a single factor.

    Contrast: Total effect of any factor.

    Levels: Levels can be said as just like different stages of any factor. An example is given below in this article.

   After determining which factors affect the response, the next step is to optimize the response that is to maximize or minimize the response. Response surface methodology (RSM) can be used for this optimization. 

 Two factor factorial design:

Suppose, there are two factors A and B. Factor A has 'a' levels and factor B has 'b' levels. There are 'n' replicates. These information can be represented like this:

Here, total runs or observations are abn.

To clarify what is levels of any factor, if we consider factor A is 'temperature' and data are collected at 15 degree, 20 degree and 50 degree to analyze the response; then these three stages of temperature are called three levels of this factor. So here, factor A has three levels

factorial design:

Suppose, we have two factors A and B; each at two levels. The levels are called ‘low’ and ‘high’ and are denoted as ‘-’ and ‘+’ respectively.

In this table, we can see the responses at different combinations for the factors. One replicate is used here. If there were more replicates, then cell total would be used for calculations.  

The interaction effect is denoted as AB. Effect of factor A is A and effect of factor B is B.

The four treatment combinations are represented by lowercase letters. The conventions are:

• When treatment combination of A at high level and B at low level, this is represented by a
• When treatment combination of A at low level and B at high level, this is represented by b
• Both factors are at high level, ab represents this
•  Both factors are at low level, (1) represents this

So we can see that, high level of any factor in the combination is denoted by corresponding lowercase letter and it also denotes that the other factor is at low level. 

Don't be confused with these lowercase letters and when we say factor A has 'a' levels. If it is said, factor A has 'a' levels; this does not mean that A is at high level. Here 'a' is just number of levels; like three levels of factor, a=3; five levels, a=5 etc. But in treatment combinations, this is the convention to use a to indicate that A is at high level and B is at low level. If we use the responses from above table, a will be 40; b will be 30; ab will be 12; (1) will be 20.

Algebraic signs for calculating effects in the design are:

For example, to estimate A, the contrast is: – (1) +a – b + ab

If we use the responses given above, the main effect of factor A will be: 
                                                 
(here, n is replicate, k is factor)

factorial design:

Fractional factorial designs:

design requires 64 runs which make the calculations so difficult. So only a fraction of complete factorial experiment is done here, this is fractional factorial designs.

One-half fraction of  design:

This design will contain runs of,
                                        

One-quarter fraction of  design:

This design will contain runs of ,
                                                    

factorial design:

This is k factors each at 3 levels. Three levels could be low, intermediate and high and are denoted as – 1, 0, + 1.

When factors are random:

In the above discussion, the factors are assumed to be fixed. Random factors are considered when there are large number of population levels and the factor levels are chosen at random. Suppose, there are several ovens in a working shop and three ovens are chosen at random for experiment. Here ovens will be treated as random factor.

When factors are both fixed and random:

Situations may arise when some factors would be fixed and others would be random.

Factorial design is a vast concept. Only some theoretical concepts are discussed here. Calculations can be done both by manually and with computer. Statistical software Minitab can be used to solve problems related with factorial design.

Reference: Design and Analysis of Experiments by Douglas C. Montgomery