introduction to cellular systems

... Trang 2An Introduction to Microelectromechanical Systems EngineeringSecond Edition Trang 3For a listing of recent titles in the Artech House MicroelectromechanicalSystems (MEMS) Series, turn to the ... to the back of this book. Trang 4An Introduction to Microelectromechanical Systems EngineeringSecond Edition Nadim Maluf Kirt Williams Artech House, Inc. Boston • London www.artechhouse.com Trang ... Components: Capacitors and Inductors 190Quality Factor and Parasitics in Passive Components 190 CHAPTER 8 Trang 12Types of Packaging Solutions 233Trang 13.Trang 14According to my best recollection,

Ngày tải lên: 25/01/2014, 13:20

... sponsored by SPIE of Bellingham, Washington • Micro Total Analysis Systems ( µTAS): a conference focusing on microanalyti-cal and chemimicroanalyti-cal systems It is an annual meeting and alternates ... Microelectromechanical structures and systems are miniature devices that enable the operation of complex systems They exist today in many environments, espe-cially automotive, medical, consumer, industrial, ... generic tools, then there is no rea-son to limit its use to one material Indeed, micromachining has been demonstrated using silicon, glass, ceramics, polymers, and compound semiconductors made

Ngày tải lên: 25/01/2014, 13:20

... Trang 1Introduction to Database SystemsModule 1, Lecture 1 Instructor: Raghu Ramakrishnan raghu@cs.wisc.edu UW-Madison Trang 2What Is ... System (DBMS) is a software package designed to store and manage databases Trang 3Why Use a DBMS?Trang 4Why Study Databases??– at the “low end”: scramble to webspace (a mess!) – at the “high end”: ... 12Ensuring Atomicityeven if system crashes in the middle of a Xact ❖ Idea: Keep a log (history) of all actions carried out by the DBMS while executing a set of Xacts: – Before a change is made to the

Ngày tải lên: 30/03/2014, 13:20

... unordered, left to right 3 Tuples are unordered, top to bottom 4 There are no duplicate tuples Now justify them: 1 Regarding normalization: You should be aware that the history here is somewhat ... you might want to point out that null is not a value, so right here we have an overwhelming argument against nulls (as usually understood) • There's no left-to-right ordering to the components ... 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

Ngày tải lên: 06/08/2014, 01:21

... 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

... 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

... 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) ... 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 ... ubiquitous that the unqualified term view has come to mean, almost always, a "materialized view" specifically! And so we no longer have a good term to use when we want to refer to a view

Ngày tải lên: 06/08/2014, 01:21

... probably just be skimmed if the instructor doesn't want to get too deeply into formal proofs and the like Indeed, the chapter is included, in part, just to show that there really is some mathematical ... specifically The "right" way to do database design is to do a clean logical design first, and then, as a separate and subsequent step, to map that logical design into whatever physical structures ... the FD notion might have a role to play in logical database Trang 6design──we'll be wanting to get rid of redundancy and therefore we'll be wanting to find ways to get rid of certain FDs) • Some

Ngày tải lên: 06/08/2014, 01:21

... possible to "spot" a BCNF decomposition──only that it's often possible to do so in practical cases To revert to the company database example: As a subsidiary exercise──not much to do with ... candidate key, together with an attribute for every box pointed to from the original box (and no other attributes) Of course, some refinement is needed to this loose statement in order to take care ... of the exercise and those corresponding to reasonable semantic assumptions (stated explicitly below) The attribute names are intended to be self-explanatory ╔════════════════════════════════════════════════════════════════╗

Ngày tải lên: 06/08/2014, 01:21

... in DK/NF, then R is automatically in 5NF (and hence 4NF, BCNF, etc.) as well However, it's wrong to think of DK/NF as another step in the progression from 1NF to 2NF to to 5NF, because 5NF is ... introductory paragraph) of the text──slightly edited here──of a message posted on the website www.dbdebunk.com in May 2003 It's my response to a question from someone I'll refer to here as Victor ... is straightforward──all that's necessary is to replace the references to FDs and BCNF by analogous references to MVDs and 4NF, thus: 1 Initialize D to contain just R 2 For each non4NF relvar

Ngày tải lên: 06/08/2014, 01:21

... in the morning The solution to the problem is to introduce a mechanism (door locks) and a protocol for using that mechanism (lock the bathroom door if you don't want to be disturbed) ────────── ... Self-explanatory 16.5 Deadlock Mostly self-explanatory Explain the Wait-For Graph (it isn't discussed in detail in the text because it's fairly obvious, not to say trivial; see the answer to Exercise ... mention locks, as such, at all──deliberately The idea is to allow an implementation to use some nonlocking scheme if it wants to.) Explain phantoms and the basic idea (only) of predicate locking

Ngày tải lên: 06/08/2014, 01:21

... (So what are object systems going to do?) 18.5 Database Statistics Self-explanatory, pretty much (but see Exercise 18.15) Be sure to mention RUNSTATS (or some counterpart to RUNSTATS) 18.6 A ... "human factors" aspect: If the original unoptimized query took three hours to run, the final version will run in just over one second It can reasonably be argued that relational systems stand ... question Could perhaps sidetrack to review the origins of SQL here, and the current ironical situation, if the instructor is familiar with this story and wants to discuss it (see reference [4.16])

Ngày tải lên: 06/08/2014, 01:21

... representation, together with a corresponding selector operator and a corresponding set of THE_ operators (or logical equivalents of same) ■ "=" and ":=" operators ■ Certain type ... operators that applied to values of type A would be a subset of the set of operators that applied to values of type B and vice versa (and, of course, the set of constraints that applied to values ... read-only vs update operator distinctions come into play Other approaches don't make these distinctions; they thus allow operators (update as well as read-only operators) to be inherited indiscriminately──with

Ngày tải lên: 06/08/2014, 01:21

... tends to be driven by physical considerations much more than by logical ones──indeed, it tends to blur the logical vs physical distinction considerably." Caveat lector We use SQL, not Tutorial ... begin to believe the world is two-dimensional You think you can get anything into the rows and columns of a table" [Douglas Barry, Executive Director, ODMG] • "There is simply no way to ... snapshots Annotation to those references talks in terms of snapshots, not views Trang 8(End quote) Answers to Exercises 22.1 To quote from Section 22.5: "Operational systems usually have

Ngày tải lên: 06/08/2014, 01:21

... they aren't applicable only to "logic-based systems"──they can be used in conventional systems too, as the annotation to reference [18.22] explains) Answers to Exercises 24.1 a Valid b ... whether the FROM-TO intervals in the previous version of the database are to be interpreted as closed or open with respect to FROM and TO Previously, those intervals were implicitly taken to be closed ... constraints to guard against the absurdity of a FROM-TO pair appearing in which the TO value is less than the FROM value are no longer necessary, because the constraint "FROM ≤ TO" is

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 ... designs Third, relational systems provide a wide array of operators, the effect of which is (in part) that there's no logical incentive for biasing designs in such a way as to favor some applications

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