There are perhaps several hundred ways to say this, most of which depend on the personality, background, nationality, education, social class, etc. of the person involved. A colorful example:
The deuce you say!
This is a British expression dating back to the 17th century where "deuce" is used in place of "devil" ("The devil you say!"). I'm not sure how formal it is, but it seems to have been acceptable between Victorian gentlemen (although possibly not when ladies were present).
Apparently it means something more like "I don't believe what you just said!" which can sometimes be the purpose of saying "What the hell are you talking about?"
In a similar way you can often substitute the mild epithet "heck" for "hell":
What the heck are you talking about?
Other possibilities:
What in the world are you saying?
What on earth do you mean?
What in God's name are you talking about?
More colloquially:
What the dickens are you talking about?
What in blue blazes are you talking about?
What on God's green Earth are you talking about?
Of course, you can always go the other direction by using stronger epithets than "hell". Feel free to get creative.
Yes, a common word for that is revealing as in revealing clothes. The idea here is that it reveals more about a woman than it should be. Another good one and equally common is skimpy as in skimpy skirt. So, you could say:
The clothes worn by western women could be considered too revealing in Muslim countries.
As for the adjective to describe a woman who wears revealing clothes, I don't think there is a special term for that in English that's common enough that you'll ever hear it used, but the closest thing that I can think of would be floozy. floozy is basically a slur for a woman who looks like a prostitute.
PS: people have been giving a lot of feedback in the comments section. Some of them aren't fond of the idea that what has been offered so far has mostly been vulgar slang. If you're looking for a term that's non-derogatory and neutral in language, immodest woman or immodestly dressed woman could be your best bet. This adjective was suggested by Nigel Touch (in the comments section).
Considering the new information you provided us with, all I can say is that what we are really dealing with here is terminology specific to a particular field in a foreign language. The typical way to go about this is to use the word as it appears in the original language but in its transliterated form with a remark about its meaning when the word is first introduced to the audience. This is commonly done for words that don't have equivalents in the English language. That's actually one way new vocabulary is created. There are many examples of Arabic words in English that have entered the language for the exact same reason—they have no English counterparts. Among them are terms like dunya, iman, fatwat, tawhid and many more others. Simply put, when speaking in the context of Islam, those are the words you would be using instead of analogous English ones that might be similar in meaning but don't quite capture the idea accurately.
Best Answer
I'll answer these questions in reverse order:
Yes; improve is a verb, not a noun. Therefore, you should say, "I want to do this improvement..."
You can use this, but it's unnecessarily wordy. This time, you should consider using more direct language, by switching from the verb to the noun: "I intend to improve this paper"
Perhaps, and perhaps not. All we know about these "subjects" right now is that we have two examples: "modelling" and "simulation." How are these referred to within your area of expertise? Are they subjects? Areas? Fields? Domains? A project proposal often uses specialized language, and you should use the term that is most fitting for your area of study.
Lastly, there's this:
That's a bad goal, particularly if you're not a native English speaker. You should be striving for simplicity and clarity, not "sophistication." It's a gift to be able to write concisely without muddling up your text with unnecessarily complex words. You don't want to oversimplify your text – if you need to use a sophisticated word, then do so, but you should be doing that to make your message more clear for your intended audience, not just to add an element of sophistication.
Here's my recommendation, based on what I see so far (although I may be misinterpreting what you are trying to convey):