part i  an introduction to twisted

... sleepy, feel free to go out, no need to ask for lecturer’s permission) #4 No food (but drinks are permitted) #5 No cellphones (switch off your phone ring before class starting) #6 No laptop, iPad, iPod ... (switch off your phone ring before class starting) #6 No laptop, iPad, iPod #7 No need to ask for the permission to be absence for class (don’t cheat or tell lie) #8 No mark bargaining!!! Chương Giới

Ngày tải lên: 03/09/2017, 09:17

... the keyboard  Writing to a file  Sending output to a file  Done from beginning to end (for now)  No backing up to write something again( OK to start over)  Just as done to the screen Trang ... fails, it is generally best to stop the program  The function exit, halts a program  exit returns its argument to the operating system  exit causes program execution to stop  exit is NOT a member ... program to stop printing plus signs on positive numbers Trang 45 A manipulator is a function called in a nontraditional way  Manipulators in turn call member functions  Manipulators may

Ngày tải lên: 12/09/2012, 22:49

... input to the join, meaning there's less data to be scanned to do the join, and the result of the join is smaller as well In fact, the second expression might allow the result of the join to be ... corresponds more directly to the semijoin formulation than to the join one Analogous remarks apply to semidifference Trang 4Regarding extend: EXTEND is one of the most useful operators of all Consider ... aggregate operators COUNT, SUM, etc., are first mentioned Observe the important differences (both syntactic and semantic) in the treatment of such operators between Tutorial D and SQL Note too the

Ngày tải lên: 06/08/2014, 01:21

... "constructor" we need is an operator that creates a relvar (e.g., CREATE TABLE, in SQL terms) Selectors, by contrast, select values Also, of course, constructors return pointers to the constructed ... though I would prefer to use the more conventional term operators.* Bundling methods with classes is not essential, however, and leads to several problems [3.3]; I would prefer to define "classes" ... in two different senses: Sometimes it seems to mean the operator as seen by the user, sometimes it seems to mean the code that implements that operator Yet another example of confusing model and

Ngày tải lên: 06/08/2014, 01:21

... Point out that (to quote) "the XML document isn't a very faithful representation of a parts relation, because it imposes a top-to-bottom sequence on the tuples and a left-to-right sequence ... the user to navigate to the others • The World Wide Web is the agggregate of information stored on the Internet, together with the associated Web standards for interfaces and protocols by ... these is very unclear to me, since (as we saw in the previous section) XML collection support has nothing to do with the DBMS, and SQL is supposed to a standard that relates to DBMSs (meaning functionality

Ngày tải lên: 06/08/2014, 01:21

... operator (see Chapter 5), and the whole idea of being able to invoke it from inside a read-only operation (SELECT in SQL) is more than a little suspect [3.3] • Consider the expression XMLFILETOCLOB ... XMLFILETOCLOB function is more than a little reminiscent of the EXECUTE IMMEDIATE operation of dynamic SQL (see Chapter 4) • Remarks analogous to those in the previous paragraph apply also to arguments ... ability for users to define their own types; they therefore don't force users to represent everything in character-string form, and indeed they provide very strong incentives not to Second, there's

Ngày tải lên: 06/08/2014, 01:21

... sum of the kinetic energy (K) and the stored energy (S) to be equal to the sum of the work rate (power, P) and the net heat supplied (H): d where the stored energy comprises a thermal part, 30 ... assumed to be proportional to the amount of the gaseous substance available to be compressed in the contact area between the particles A typical ad hoc approximation in combustion processes is to ... efficiently the surface radiates energy compared to a black-body (an ideal emitter); 0 ≤ hc is the heating due to convection (Newton’s law of cooling) into the dilute gas; anda s is the surface area

Ngày tải lên: 06/08/2014, 01:21

... Multiple scatterers 115Figure 9.6 Top to bottom and left to right, the progressive movement of rays making up a beam (L = 0.325 and ˆn = 10) The lengths of the vectors indicate the irradiance (Zohdi ... of the sum of the kinetic energy (K) and stored energy (S) to be equal to the sum of the work rate (power,P) and the net heat supplied (H): d where the stored energy comprises a thermal part, S(t) ... the process, a negligible mechanical stored energy portion The kinetic energy isK(t) = 1 2mv(t) · v(t) The mechanical power term is due to the total forces ( tot) acting on a particle, namely,

Ngày tải lên: 06/08/2014, 01:21

... constellations from which they appear to emanate Such debris may lead not only to mechanical damage to the satellites but also to instrumentation failure by disintegrating into charged particle-laden plasmas, ... The so-called Stokes condition attempts to force the thermodynamic pressure to collapse to the classical definition of mechanical pressure, i.e., trσ 3 = −P + 3κ vtrD leading to the conclusion ... ·dX → dx, or a change in configuration (reference to current), while F ·dx → dX maps the current to the reference system For the deformations to be invertible, and physically realizable,F · (F

Ngày tải lên: 06/08/2014, 01:21

... they wish to maximize their revenues You wish to route the message along the least-cost route (note that this is different from wishing to pay the least amount of money; you care about the total ... Positive Result: The Vickrey-Clarke-Groves Mechanism If we are to design a truthful mechanism that is not dictatorial, we are going to have to relax some of the conditions of the Gibbard-Satterthwaite ... wishes to purchase it at the lowest possible price Our task is to design a protocol for this auction that satisfies certain desirable global criteria For example, we might want an auction protocol

Ngày tải lên: 08/08/2014, 11:21

... auctions Perhaps the most straightforward way to tie goods together is to allow bid-ders to bid on combinations of goods For example, to allow a bidder to offer $100 for the pair (TV, DVD player), ... the combinatorial auction problem is to select an allocation a : 2 X → N of goods to agents that maximizes some measure such as total revenue to the auctioneer, or efficiency Combinatorial auctions ... two ways to tie the goods together in an auction One way is to run essentially separate auctions for the different goods, but to connect them at in certain ways For example, one way is to have

Ngày tải lên: 08/08/2014, 11:21

... protocol maximizes the total revenue to the seller 2 Efficiency The auction protocol allocates the goods to the bidders who value them the highest 3 Incentive compatibility The auction protocol ... valuation defined above In order to represent this valuation, we will need to be able to bid on disjunctions of atomic valuations An OR bid is a disjunction of atomic bids (S1, p1) OR (S2, p2) ... auctioneer is trying to maximize Thus the bidder has incentive to report his true valuation function It is more difficult to show that the VCG combinatorial auction maximizes revenue to the auctioneer

Ngày tải lên: 08/08/2014, 11:21

... are unordered, left to right Tuples are unordered, top to bottom There are no duplicate tuples Now justify them: Regarding normalization: You should be aware that the history here is somewhat ... implementation is required to assign names to otherwise anonymous columns, but those names are implementation-dependent (they vary from system to system, possibly even from release to release or even ... worth making a separate topic out of them in a live class Relations with No Attributes A gentle introduction to this concept is DEFINITELY worth including as a separate topic Strong logical justification:...

Ngày tải lên: 06/08/2014, 01:21

... TEACHER to OFFERING, ENROLLMENT to OFFERING, and OFFERING to COURSE are all properly maintained, the referential constraints from TEACHER to COURSE and ENROLLMENT to COURSE will be maintained automatically ... update operation must ever assign to any relvar a value that causes its relvar predicate to evaluate to FALSE The text doesn't say this explicitly, but the rule applies to all relvars, derived as well ... might be to keep the legal city names in a relvar and to use foreign keys to ensure that no other relvar ever includes a city name that isn't one of the legal ones (this approach is likely to be...

Ngày tải lên: 06/08/2014, 01:21

... then we have to face up to questions such as: Does (e.g.) many -to- one mean a relationship that's inherently, necessarily many -to- one, or does it mean one that just happens to be many -to- one because ... applies to INSERT: a Inserting the tuple (s,sn,st,sc,rt) into the join is equivalent to inserting the tuple (s,sn,st,sc) into S (unless it's already present) and inserting the tuple (s,rt) into SR ... fairly self-explanatory (though project is a little trickier than the operators covered prior to this point) Note: The subsection says: "An attempt to update the SC tuple (S1,London) to (S2,London)...

Ngày tải lên: 06/08/2014, 01:21