Object -Oriented Databases ObjectOriented Databases

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Description

• mémoire
• mémoire - matière : database

Object-Oriented Databases db4o: Part 1 • Managing Databases, Storing and Retrieving Objects • Query by Example, Native Queries, SODA • Simple and Complex Objects, Activation, Transactions October 3, 2008 1Michael Grossniklaus – Department of Computer Science –

• integration with native garbage collection
• native queries
• transactional slots database file
• stores objects of arbitrary complexity
• databases db4o
• db4o
• publication
• objects
• public string

Sujets

• Mémoire
• Database
• Norrie
• Computer science
• Publication
• Public
• Object
• Arbitrariness
• Complexity

Informations

• Publié par: vosom
• Nombre de lectures: 24
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

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English Phonology

Lecture 1: Phonemes and Allophones; Describing English Sounds

What is language? What is it that we know when we know a language?
What is it that we know when we know English?

I. Phonological Knowledge (roughly):

a) Sounds
b) Sound Patterns

Thus, phonologists are concerned with:

a. Sound Inventory

What sounds does the language make use of?

Exercise 1: Which ones of the followings are possible sounds of English?

a. [ !]: as in tut-tut! / tsk-tsk!
b. [y]
c. [ ]
d. [ ]
e. [ ]

What relationship do these sounds have to each other?
Which are used contrastively and which are the variant pronunciations of
contrastive sounds?
Can we predict the different realizations of a contrastive sound?

b. Sound patterns
Which sound combinations are allowed?

Exercise 1: Which of the followings can be a possible word of English?

a. hled
b. ok
c. tlnaz
d. ala
e. pkar
f. plask
g. talg


1II. The concept of phoneme and allophony: “Same but different”:

Aspirated vs. unaspirated stops in English

pill spill
tt
kill skill

PHONETIC FACT: There is a burst or puff of air after the /p/ in pill, till, and kill,
that is absent in spill, still, and skill.
Aspiration: The period between the release of the closure of a consonant and
the start of the vocal cord activity for the vowel that comes after it. This period is
usually felt as a puff of air.
hpill [p Il] spill [spIl]
htt Il] sttIl]
hkill [k Iskill [skIl]

Aspiration Rule in English: Aspiration occurs on all voiceless stops occurring
as the first sound in a stressed syllable.
• Although aspirated stops and unaspirated stops are physically different ,
we consider both to be the same sound.
• For English, aspiration is not employed to create a meaning difference.

2• Human mind also ignore other physical/perceptible differences which are
not relevant for particular purposes:









shoes






3a a A
A a A
The first letter of the alphabet

4II. Same sounds but different representations

Two or more languages might share the same sound or sounds but this does not
mean that those languages organize these sounds in the same way.


a. Hindi aspirated stops:
h[p al] "knife edge"
[pal] "take care of"
[kapi] "copy"
h[kap i] "ample"

• Aspiration is "contrastive" in Hindi.
h• [pal] for "knife edge" instead of [p al] is like saying "shave" instead of
"save".
• Hindi speakers cannot "overlook" the difference between aspirated and
unaspirated stops because they distinguish meaning based it.

b. [s] and [ ] in English and Japanese:

Japanese English
[ imasu] ‘do’ [slæ ] ‘slash’

English: Can [s] and [ ] can distinguish meaning?
Hint: Look for “minimal pairs”!

[ el] ‘shell’ [mæ ] ‘mash’

[sel] ‘sell’ [mæs] ‘mass’
Japanese: Can [s] and [ ] distinguish meaning?
• Unlike English, these two sounds cannot distinguish meaning in Japanese
because we cannot find any minimal pairs contrasting these two sounds.
• Say [simasu] instead of [ imasu]: would the meaning of the word change?
5• You might, at most, be perceived as a foreigner and sound funny.
• Try to do the same with: "I [s/ ]aved my head this morning"
• If there is [i] in a word, we will never see the sound [s] before it.
• Given [s] and [ ], what can then precede an [i] in Japanese?
Phonological Conclusions:
• [s] and [ ] are contrastive and the occurrence of the two is unpredictable in
English.
• In Japanese, we can predict their distribution.
• In Japanese, [s] and [ ] are considered to be the "same" sound even
though they may be phonetically distinct.
Phonology deals with the following questions:
1. Of all the sounds in a language, which are predictable?
2. What is the phonetic context that allows us to predict the occurrence of
these sounds?
3. Which sounds affect the meaning of words?


c. English lateral liquid (/l/):
lean
let
lace
kneel
tell
sail





6Articulatory Facts about /l/: An alveolar consonant


But, when saying the first three words (i.e., lean, let, lace):
[l]: clear ‘l’ / alveolar lateral
Tip of the tongue: high, touches the alveolar ridge
Back of the tongue: down
Sides of the tongue: drawn in so that the air escapes around the tongue

But, When saying the last three words (i.e., kneal, tell, sail):
[ ]: dark ‘l’ / velarized lateral
Tip of the tongue: may be raised
Back of the tongue: high
Center of the tongue: low
Sides of the tongue: curled in

• /l/ may be pronounced several different ways. And, we overlook this
difference when we learn words that contain this sound.
What is the distribution?
Rule (to be revised in the following lectures):
Before a vowel, we say [l], after a vowel we say [ ].
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Thus, English [l] and [ ] are in predictable (complementary) distribution.

Turkish Scots Gaelic
[so ] ‘left’ [bala] ‘town’
[sol] ‘a musical note’ [ba a] ‘wall’



d. English voiceless alveolar stop /t/:
tip
stick
little
Acoustic/ articulatory phonetic facts:
FACT #1: Aspiration

Examples:
h[p at] vs. [spat] "pot" vs "spot"
h[t ek] vs. [stek] "take" vs. "stake"
FACT #2
a. Speakers of American English:
The /t/ in "little" sounds a lot "softer" (and a bit voiced). In American English, this
sound is actually pronounced as a flap ([ ]).
Flap: A flap sound is a consonant in which one articulator strikes the other with a
sliding motion (as in the Spanish word pero).
b. Speakers of (non-Standard) British English:
/t/ is pronounced as a glottal stop [ ]

• At least at some psychological level, that this word contains a /t/ sound
although we may not pronounce or hear it as such.
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/t/

h[t] [t ] [r] [ ]
_________________________________________________


What is a phoneme?
A class of speech sounds that are identified by a native speaker as the same
sound is called a phoneme.
The different phonetic realizations of a phoneme are called allophones.

Thus:
h[p ] and [p] are the allophones of the same phoneme in English; Whereas in
hHindi, [p ] and [p] are different phonemes.
[l] and [ ] are the allophones of the same phoneme in English; whereas in
Turkish and Scots Gaelic, they are different phonemes.
9Phonemes are the psychological (abstract) representations or units of actual
physical realizations of phonetic segments.

Remember:

If two sounds are separate phonemes, then they are contrastive (in terms of
meaning).
• If the two phones are allophones of the same phoneme, then they are
non-contrastive.
• To determine whether a given pair of sounds is contrastive, linguists look
for minimal pairs.

Minimal Pair:
A minimal pair is a pair of words with different meanings with exactly the same
pronunciation except for one sound that differs.
Examples:
• [tek] vs. [tep] "take" vs "tape"
• [tim] vs [dim] "team" vs "deam"
h• [kapi] vs [kap i] "copy" vs. "ample" (Hindi)
Do [l] and [r] belong to the same phoneme in English?
Look for minimal pairs!
[lif] "leaf"
[rif] "reef"
[læk] "lack"
[ræk] "rack".
Given that we have minimal pairs that contain [l] and [r], we can say that [l] and
[r] are contrastive thus they are separate phonemes (i.e. they are NOT
allophones of the same phoneme).
How about in Korean?
[param] "wind"
[irim] "name"
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