This file contains a log of the important messages exchanged on the CS101(B1)/F97 class mailing list -------------------------------------------------------- From best Tue Sep 23 23:13:18 -0400 1997 From: Azer Bestavros To: cs101b1 Subject: Few important announcements... PLEASE READ! Unannounced Class Quizes ------------------------ Some of you asked whether these will be held at the beginning or at the end of a class. The answer is "either". If you leave class early and the quiz is done at the end of the class, you will be assumed absent. If you come to class late and the quiz is done at the beginning of the class, you will be assumed absent. The quizes will constitute 10% of "Extra Credit" that you can earn to complement your homework, midterm, and final exam grades. Etiquette of postings to the mailing list ----------------------------------------- Some of you have committed the mistake of sending the email required for question 2 of homework 2 to the "cs101b1" mailing list instead of sending it to the "cs101b1-hw" address specified in the homework. Whether this was done intentionally or inadvertently (in either case your homework grade will suffer), I want to emphasize that in the future you should exercise some caution/restraint before sending an email to the class mailing list. An email sent to this list reaches every student in the class (+ myself + the TF + the graders). So, unless you have a question/comment/etc. of interest to a large number of students, please send it to directly to thise concerned (as opposed to broadcasting it on the mailing list). Questions I refuse to answer ---------------------------- I am surprised at the number of people asking questions that are clearly answered in the syllabus and on the web pages (e.g. "where could I get a homework", "where should I hand in the homework", "when is the final", "when is the midterm", etc.) I refuse to answer such questions, whether they are sent by email or asked in person. READ THE SYLLABUS! THAT IS THE LEAST YOU CAN DO FOR A CLASS IN WHICH YOU ARE ENROLLED! --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer From best Tue Sep 23 23:56:49 -0400 1997 From: Azer Bestavros To: cs101b1 Subject: Lecture Slides are on the Web As promised in class this afternoon, the slides for all lectures so far have been posted on the Class Web Page. Please note that printing these slides will not likely result in "good quality printout" due to the graphics included in the slides---not to mention the big waste of paper if you print them out. Thus, I recommend that you spend sometime every week looking at these slides "on-line" in the lab to fix/complement your own notes taken in class. --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer From jaeheey@cs.bu.edu Thu Sep 25 20:13:23 1997 Delivery-Date: Thu, 25 Sep 97 20:14:29 -0400 Return-Path: jaeheey@cs.bu.edu Date: Thu, 25 Sep 1997 20:13:16 -0400 (EDT) From: Jaehee Yoon To: cs101b1@cs.bu.edu Subject: Solution of HW#1 I will return the graded homework #1 in discussion section during next week. If some of them are not picked up by then, I will put them on the HW drop box. If you lose your homework due to late picking up, it's your responsibility. Here is the solution and grading policy from grader. ----------------------------------------------------------------- 1.) 33 yrs 12 mths 1 prd ------ x ------- x ------- = 22 periods 1 yr 18 mths 72 hrs ------ = 0.000017 hrs = 0.0010 mins = 0.062 secs 2^22 2.) 60 wpm x 5 cpw = 300 cpm 300 cpm ------- = 5 cps 60 spm 500 cps ------- = 100 5 cps > 100 users 3.) online 4.) online Some notes: Considering that all the data had 2 or 3 significant digits for quest 1, I was surprised to see the range of answers in terms of how many significant digits people used. Some gave only one and others gave 12. I tried to grade according to what the answer would be if the numbers were rounded to the nearest 2 significant digit. For quest 2, I looked for the answer greater than 100. Many people gave 100, which, according to the data given, would be incorrect, though in real systems this wouldn't really be the case. I took off 5 pts for an answer of 100. In both questions, I tried to give partial credit. --------------------------------------------------------------------------- -Jaehee From best Mon Sep 29 15:11:12 -0400 1997 From: Azer Bestavros To: cs101b1 Subject: Grades for HW1 are now on-line The grades for hw1 are now online. Check your grade using the getgrade utility (check the course web page for details). See you in class tomorrow. --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer From best Wed Oct 1 07:30:31 -0400 1997 From: Azer Bestavros To: cs101b1 Cc: donoghue@cs.bu.edu In-reply-to: (message from Sean Donoghue on Tue, 30 Sep 1997 17:36:56 -0400 (EDT)) Subject: Re: Ignore previous email % Professor Bestavros % % I believe the equation you just gave us in class is incorrect. You % said we would multiple 10 times 9 and divide that by 2. Whe you are % adding a list of numbers that include all intigers between 1 and N, % youu multiply N time N+1 and divide by two. 1+2+3+4+5+6+7+8+9+10 = 55 % which is 10*11/2 Sean: You are absolutely right... Thanks for the correction. The conclusion from the example still holds---namely, that the time it takes to sort 10 elements is *not* twice the time it takes to sort 5 elements, but much more. The situation is even worse as the list gets larger. The time for sorting a list of 1000 numbers is *not* 100 times the time to sort a 10 number list, but (approximately) 10,000 times that!!! We'll talk more about this when we discuss time complexity of algorithms... --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer From best Wed Oct 1 18:20:14 -0400 1997 From: Azer Bestavros To: mcluzet@bu.edu cc: cs101b1 In-reply-to: <3432C772.1F5C@bu.edu> (message from Martin Cluzet on Wed, 01 Oct 1997 17:58:11 -0400) Subject: Re: Slides 16 and 17 % Professor, % I tried to look at slides 16 and 17 from the last set of slides you % have on the web about html, but I got a message that said % "404 not found" I need to know how to insert an image on my web page... I will look into this. Thank for letting me know. --Azer From best Thu Oct 2 09:44:17 -0400 1997 From: Azer Bestavros To: cs101b1 Subject: Home Page for Students in the class There is now a Home Page with a list of all students in the class and a pointer to their Home Page. To access the Student Home Pages, go to the Class Home Page and pick the "Student Home Pages" anchor. Warning: ------- Your Home Page can be read by ANYBODY out there. Thus, do not put information that you feel is personal and could be used to (say) invade your privacy or for harrasement. You are forewarned. --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer From jaeheey@cs.bu.edu Thu Oct 9 11:08:00 1997 Delivery-Date: Thu, 09 Oct 97 11:08:58 -0400 Return-Path: jaeheey@cs.bu.edu Date: Thu, 9 Oct 1997 11:07:54 -0400 (EDT) From: Jaehee Yoon To: cs101b1@cs.bu.edu Subject: solution of HW #2 1b. Violations should be reported to IT, UIS, or office of internal audit 1c. Eleven days were skipped to make up for lack of leap year adjustments 1d. Five ppl have Churchill as their _LAST_ name 1i. Varies 1h. Varies 2. 3a. A program is a series of step-by-step instructions that direct a computer to perform specific tasks. A process is a program currently being executed. 3b. The management of concurrent processes means that the processor is waiting for input from each terminal until it asks the CPU to perform something, and it then processes the request(quicker than you can notice) 3c. Primary memory is the computers RAM, this is the main memory in the computer and is used for storing data currently being accessed. Secondary memory is where information and program are kept in storage, it consists of harddrives, floppy drives, tape drives, etc. Virtual memory is a way of makeing the computer think it has more RAM than it does by utilizing spare secondary memory to create the illusion that the computer has more RAM than it does. Virtual memory is drastically slower than primary memory. 3d. a Multi-user OS is an OS that allows more than one person to concurrently utilize the computers resources. This is done through a method called time sharing a Multi-process OS is an OS that doesn't necesarrily allow more than one person to use it, but it does allow more than one program to be executed at once. 3e. Yes, if a MP OS is installed on the computer such as Win95, mac7, unix, linux then a single user system could be a MP OS. 3f. ROM must be a port of the computers main memory because RAM is volatile and won't keep data in it between powerdowns, while ROM is static and won't change. It contains information that the cmoputer needs to start up. From best Mon Oct 13 21:39:18 -0400 1997 From: Azer Bestavros To: cs101b1 Subject: Announcements, etc. 1. A reminder that tomorrow is a monday schedule and thus I will have no office hours tomorrow. 2. Homework 4 is due on Thursday (as announced in class last Thursday). 3. I will have a review session for the midterm on Thursday (during class). 4. Check your recorded grades using the on-line "getgrade" utility and report any inconsistency betwen the recorded grade and that on your returned homework. This is your responsibility. 5. Lecture 11 is now on-line. --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer From best Sun Oct 19 20:13:01 -0400 1997 From: Azer Bestavros To: cs101b1 Subject: Exam I received a number of questions (about the midterm) that I will answer for everybody in this message... 1. Calculators are allowed. 2. The exam will be on all the material covered in class, in the textbook, discussion sections, and *required* Web Readings. 3. The review sheet I went over in class last Thursday is not a substitute for studying... It is meant as an example of the type of questions you should expect, but not of the coverage. I.e. you may find topics in the midterm not covered in the review questions. --Azer ___ /\ Azer Bestavros - Assist Prof Comp Sci Dept /|__) _|_____ / \/\ Boston University, MA 02215 617-353-9726 /_|__)es|avros / \ \/\ Http://www.cs.bu.edu/~best best@bu.edu / |zer