Present Perfect vs. Present Perfect Progressive

Often time they both could be used to describe some actions. E:

Rustam has worked at Google for three months

Rustam has been working at Google for three months.

These two sentences have pretty much similar meaning.  However, it is not always like that. E2:

Marteen has seen the Prison Break twice.

Marteen has been watching Prison break for all week.

Usually below signal words can help you. Note that PPP tense keywords depict the duration of action whereas PP tense keywords depict the accomplishment.

Verb Tenses

In English, we have 12 verb tenses.

Present Tense: 

This tense is used for regularly repeated actions or regularly not happening actions. E : My mom watches TV every night.

Past Tense: 

Something that happened in the past. E: I broke my leg last weekend.

Future Tense:

An action that didn’t happen yet, but will happen in the future. E: I will enter MIT.

Present Progressive:

An action that is happening right now, but didn’t end yet. E: Mom is watching TV.

Past Progressive:

An action that was happening in the past when other action in the past happened.  E:

I was waiting for her when she arrived her room. In this sentence, the first part is Past Progressive. Simple Progressive tenses have the form S + to be + V + ing  .

Future Progressive:

Something that will be happening in future when some other action in future happens. E:

I will be doing homework when you arrive home

.

Present Perfect:

Is used to describe something that happened in the past before now. E: John has eaten Kabab before. In present perfect ‘now’ is important, in other words, an action happened before now. Something already finished until now.

Past Perfect:

Describes an action that already happened before another action in the past happened. In other words, first action happened before the second action. It is important to note that both of actions happened in the past. They have nothing to do with the present. E:

Jumabek had not studied seriously until he failed miserably in the exam.

This sentence is trying to say that in the past Jumabek did not study hard, but after he failed from his exam he started to take the exams seriously.  Notice the usage of

‘had’ instead of ‘did’ in the example. One happened before the other is going to be past perfect.

Future Perfect:

Used to show that something in future will happen before the other. whatever happens first is future perfect. E:

By next year, I will have published two articles.

Present Perfect Progressive:

Indicates a continuous action that is happening right now in the present. Something is happening in Present Perfect but continuously (progressively). It consist of a form S + have + been + verb + ing.  E:  He has been waiting for her for a long time. It means an act of waiting may or may not be completed, in other words, it is continuous in the present. The difference between Present Perfect and Present Perfect Progressive is the time that action goes on.

Past Perfect Progressive:

Indicates a continuous action that was completed at some point in the past.

Future Perfect Progressive: 

The future perfect progressive tense is used to talk about an action that will already have started and will still be happening by a certain time in the future.

Intro

Here I will post what I learned from the course “Academic English: Writing” which I am taking on Coursera.org.

Main purpose is to share what I learned, so that I will consolidate what I learned and hoping to be contributor to our society by benefiting you with my posts.

Below couple of reasons why you might want to improve your English Writing:

• Admission Requirements. If you wish to do graduate studies in English Speaking countries, chances are the university that you are applying will ask you for your proof English skills. Such as IELTS/TOEFL, GRE, SAT and ect.
• If your education path involves publication of scientific articles or writing thesis in an English, you probably want improve your writing skills.
• You might want to participate in online writing contests, even though you are not native, you can confidently compete quickly after you shape your writing skils

 

Bewares of C++

The default constructor case in classes.

The default constructor is called when you do not initialize an object.

class Person {

private:

string name;

int age;

Person(){

name=”no name”;

}

Person(string n, int a){

name=n;

age=a;

}

};

int main(){

Person p;  //default constructor is called

Person p();  //default constructor is NOT called

}

This is because the empty set of parentheses would make of rectc a function declaration instead of an object declaration: It would be a function that takes no arguments and returns a value of type Rectangle.

refer to http://www.cplusplus.com/doc/tutorial/classes/ for details.

 

How to Stay Motivated While Studying

As of I am writing this article, it is March 7th 2016. I am doing my final semester of Master’s Degree, according to plan I have to finish my research paper by March 11th to submit for a local conference. Despite how hard we try to work, our brain is not a box machine, it needs to learn, adapt and experience before we force it to work nonstop. I mean up until now I didn’t work hard as I am working now. Therefore, my brain  just doesn’t obey me. I have been working on my research for the last 3 days in order to finish it by the deadline (march 11). Continuously working on this single task made my brain bored, possible tired too. I started to think maybe I should take a break for 5-10 minutes then come back. Didn’t help much, whenever I start that work again I would feel some sort of difficult to explain pain in my brain. Enough is enough, I quickly searched for “how the brain works”, after reading multiple articles I concluded. When we work on the same thing for a long time, the same part of our brain (aka the same neurons that are helping us to do some magic calculation to process our thought) will work. Therefore I decided to mix things around when I work or study. For instance study math for  2 hours and then physics for another 2 hours. In my case instead of keep working on research, try something different, like writing article. Next, I was wondering how long should I work on a different task before I come back to my research. After googling, I found multiple experiments that were done on students who study only single subject for a whole day then move to next subject on another day v.s. students who alter the subjects while studying. In all of the experiments, studying subjects with altering them was highly efficient and painless comparing to studying everything in one subject then move to another. Summary I got from those experiments was that If I want to work efficiently and with less pain then I should work on a single task no more than an hour then switch to different task.  In this manner different parts of our brain will get to work. According to BARBARA OAKLEY (instructor of the course “Learning How to Learn” @ coursera.org ) repeating something 20 times in one evening is not nearly good as repeating it over several days. This technique is called “Spaced Repetition”. There you have it! To quickly recap, when you are working on something or studying:

• Use “Task Switching”
• Use “Spaced Repetition”

Most importantly do not procrastinate, otherwise as I said above, you will be in very dangerous zone.  Our brain is super learning machine, all we have to do is to use it correctly. Hope this helps to keep you motivated while studying^^

 

HOG Person Detector Tutorial

Amazing tutorial about HOG descriptor by Cris

Chris McCormick

One of the most popular and successful “person detectors” out there right now is the HOG with SVM approach. When I attended the Embedded Vision Summit in April 2013, it was the most common algorithm I heard associated with person detection.

HOG stands for Histograms of Oriented Gradients. HOG is a type of “feature descriptor”. The intent of a feature descriptor is to generalize the object in such a way that the same object (in this case a person) produces as close as possible to the same feature descriptor when viewed under different conditions. This makes the classification task easier.

The creators of this approach trained a Support Vector Machine (a type of machine learning algorithm for classification), or “SVM”, to recognize HOG descriptors of people.

The HOG person detector is fairly simple to understand (compared to SIFT object recognition, for example). One of the main reasons for this is…

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