**September-28th-09. Welcome to the String Pattern Recognition blog. **The beginning of this year's course has been the weirdest ever. It seems that the fact that my course will be taught in English has discouraged students from registering. The very first day of the course I checked on the computer how many students had registered: none. Really sad, very disheartening. So much work preparing the material for nothing.

Later on, while having a cup of coffee at the cafeteria, a couple of students came to see me. They would take my course, but they were not able to register. There was some nonsensical problem with the registration, but meanwhile they were allowed to attend class. I suppose it is the chaos associated with change of the school's curriculum.

Classes will start next Wednesday. I am looking forward to it.

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**September-30th-09. English Phonetics. **Since classes will be taught in English I decided to give a first lecture on English phonetics. I will write the phonetic transcription of the most difficult words on the blackboard. Therefore, I have to ensure they know the IPA alphabet and also they are able to identify the various sounds of English.

After asking, the students told me that they already knew some phonetics. However, pretty soon I realized that they did not know as much as I needed for this course. For most of them, a wealth of the material was unknown.

I (briefly) reviewed the following topics: vowels, consonants, semi-consonants, diphthongs, pronunciation of plurals, pronunciation of the third Person of singular of Present Simple, pronunciation of Past Simple. See the course web page for more information.

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**October****-2nd-09. Review of Algorithms and Complexity - I.** **Normal, only for this time. **Three students, only three, showed up. Later a fourth one also joined the course. This cheered me up. I might end up by having a nice crowd in the classroom.

Students had some difficulties following my lecture in English, mainly, I believe, because of lack of vocabulary. As I suspected so, I created the English corner, a part of the blackboard where I write down (phonetics included) those words I detect they have difficulties with. Attached you will find a list with some of them. I will give a similar list for each lecture in this blog.

Students are very shy when to speaking up. Furthermore, they have trouble making clear, precise sentences that can express their thoughts. I will insist on them to speak up, even if they make mistakes. Let yourself go, guys!

A summary of the last lecture is the following: definition of algorithm, Knuth's definition of algorithm, the distinction between algorithm and program, correction and complexity of algorithms, the sorting problem, insertion sort, prove of correctness for insertion sort, analysis of algorithms, worst-case complexity, best-case complexity, space complexity, average-case complexity, models of computation, real RAM, computing the complexity of insertion sort. Notes for the first lesson of the course are available HERE. And that's all, folks!

Difficult words: tough[tʌf], rough[rʌf], definite['definət], definiteness['definətness], infinite['infinət], finite['fainait], finiteness['fainaitness], effectiveness[e'fektivness], pseudocode[ˌsuːdo'kəʊd], insertion[in'sɜːʃn], cost[kɔst], assignment[ə'sainmənt], nondecreasing[nɔndekriːsiŋ], work out[wɜːkaʊt], mean[miːn], fine[fain], coarse[kɔːrs], algorithm['ælgəriðəm].

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**October****-5th-09. Review of Algorithms and Complexity - II. Correctnes of algorithms and mergesort. ** I reviewed the mergesort algorithm. I also gave a proof of correctness. Surprising enough, the lengthy part of the proof is to check that the merge step is correct. That part has to be proven in a straightforward way, without using induction. The main body of the algorithm does have to be proven, since it is a recursive one.

I haven't got my student's names so I can't start the fun part of this blog (the irony). I need their names to anagramize them. Next day I will get them.

Chaos in the registration process is still on. When will it finish? I realize it is just a miracle that I have students for these course.

Difficult words: swine flu[swain fluː], recursive, return[rɛːturn], integer['intidʒɜː(r)], therefore[ðeəfɔː(r)], hence[hens], as a consequence[əzə'kɔnsikwəns], result[ri'zult], forecast[fɔːkaːst], foretell[fɔːtel], catch[kætʃ], namely[neimli], grasp[græsp], lack[læk], deadline[dedlain], just as well[dʒʌstəzwel].

** **

**October-9th-09. Review of Algorithms and Complexity - III. First projects for the students to hand over; asymptotic notations. **Two new students arrived, **Sigmund H. Noplace** (from now on, just Sig) and **Roger Jean Juro**, a burly guy born to a French mother (hence, his middle name). In total, I have five students. Only five? Five scatterbrains? I don't think so. Let me introduce the rest of the gang: **Leonine Madcalf, Auralee Redfez and Marina Dazehair**. They all seem determined to finish their double degree. Then, five plucky fellows? Five fellows showing courage and spirit even under the most trying circumstances, for instance, the registering process for this course.

I explained their first graded project. It consists of implementing six basic sorting algorithms, compute their complexities and conduct experiments to check the running times in practice. They neither snorted nor puffed, but they seemed a little bit overwhelmed. They haven't sat down and hammered away at it yet.

Difficult words: hand over[hændəuvɜː], odd[ɔd], subtle[sʌtl], bring about[briŋə'baʊt], bumpy[bʌmpi], raw data[rɔːdeitə], blind[blaind], bear in mind[beəːrɔnmaind], insight[insait], catch[kætʃ], rationale[ˌræʃə'naːl], upper bounds[ʌpɜːbaʊndz], lower bounds[lʌwɜːbaʊndz], figure[figɜː(r)], last[last], messy[mesi], keep somebody posted['kiːpsʌm'bʌdi'pəʊstid].

**October-16th-09. First Pattern Recognition Algorithms. Inversion of terms.** In my students went. Satisfied they looked. Are they enjoying? Flu caught Roger Jean and absent he was. In a huge jam traffic Sig Noplace was caught. Possible, it wasn't his arriving. Out he was, waiting, sent into the depths of despair. Late he arrived.

Today is presentation day. To the blackboard students will go. Solving-problems section is coming up. Leonine starts off with a problem on complexity. Good, in general, small mistakes he made. Next, there Auralee goes. Very detailed work. Outstanding, in fact. The important points, she has grasped. Finally, out Marina went. A little misunderstanding happened. Nothing to worry about. She had worked on the problem and that is enough for me.

Difficult words: Claim[klaim], instill[in'stil], state[steit], exist[ig'zist], on the one hand and on the other hand, hold[hɘʊld], workout[wɔːkaʊ], suffice[sə'fais], assume[ə'sju:m], whereas[weɜːæz], staff[stæf], carry on[kæriɔn], fertile[fer'tail], whether[we'ðɜː(r)], wonder[wʌndɜː(r)], corpus[kɔːpəes], fuge[fju:g], genre['ʒa:rə], theme[θi:m], template['templeit], nod[nɔd], find out[faindaʊt], straightforward[streitfɔ:wa:d], mismatch[mismætʃ], looking forward to.

**October-19th-09. First Pattern Recognition Algorithms. Voluptuous (I).** I come in the classroom. Today I feel happy, although I don't know why exactly. I smile to myself. "Today's lecture is about prefixes and suffixes," I remind myself. All of a sudden, I get unexpectedly proud, I feel myself standing. I repeat those words -prefix and suffix- in a faint murmur. My coming aloft, far from fading away, stands still and stiff. I'll sham normality.

Strangely enough, there is a whitish mist floating around in the classroom. I look at my students through the mist, which seems to melt, to dissolve, and to become translucent when the brilliant sun comes through the large glass window and magically colors and outlins everything. I distinguish their expressions among the mist and they look happy today. Moreover, I'd say they are grinning at me with the tenderest understanding expression. However, they can't know. Or can they?

I start my lecture. Symbols for prefixes and suffixes seem to me cases for jewelry, bird's nests for warrior's refuge.

I ask one of my female students to solve a problem on the blackboard. When coming closer, she slips and falls down, and in so doing displays some of her charms; but she jumped up very quickly.

"Did you see my agility, Sir?," says she.

"Yes, Miss, I did," I exclaim, "but I never heard it called by that name before!"

(To be continued...)

Difficult words: Prefix['prifiks], suffix['sʌfiks], order[ɔːrdɜː(r)], relation[ri'leiʃən], antisymmetric['æntisi'metrik], reckon['rekən], naive[naiv], loop[lu:p].

**October-23th-09. First Pattern Recognition Algorithms. Voluptuous (II).** Next class. I can't think of the word "prefix" or "suffix" without feeling a sweet stretching of my morning pride. I also remember my student's agility and feel embarrassed. Sometimes, life puts one in awkward situations. Anyhow, in the cold light of the day, it was just a curious anecdote.

I am ready to give another fun, beautiful lecture on string pattern recognition. Today I will cover the naive algorithm and its complexity. I start talking calmly but with fluidity. Somehow, I don't keep eye contact with my students. I am concentrated on the formulas written on the blackboard. I think I should look at them. I do so.

Radiant countenances, splendorous gazes, dazzlingly beautiful figures, youth oozing out of them at every pore, tireless determination to drink up life, all that was possessed by my students. All that is waiting in front of me. They also look at me, as if waiting some prompting signal. Skeptically but at the same time amazed, I look at them once more.

I see a woman with big brown eyes, so big that they bewilder me as nothing could hide them (not even padding). Rounded face, jet black straight hair, very stylish horn-rimmed glasses, generously curvaceous, disarmingly sonsy, her smile, made of perfectly aligned teeth, is shinning white in the middle of her face, ranging from innocency to mischievousness. Her presence fills up the whole classroom with a vivid sense of sensuality.

I shake my head in wonder and disbelief.

I turn my look from that student and my eyes trip over another female student. A brunette, a slender figure with shapely legs, gracious waistline, the delicate arms of a belly dancer and olive-coloured complexion, just returns my look with a knowing smile. At that moment I notice her neck an then hopelessly sink in the vision of her cleavage. This is the tale of two cities split by a gorge, each of which is on the top of the fullest, most tantalizing mountains. Raspberries grow tumidly.

(To be continued...)

Difficult words: loop[lu:p], in fact[in'fækt] (different from fuck[fʌk]), differ from['difɜː(r)frəm], disjoint[dis'dʒɔint], cancel out['kænslaʊt], expectation[ˌekspek'teiʃn], geometric[ˌdʒi:ə'metrik], bound[baʊnd], trouble[trʌbl], drop[drɔp], start from scratch['sta:tfrəm'skrætʃ], expository[ˌekspəsi'tɔri], purposes[pɜːpəsiz], speed up[spi:dʌp], expansion[ik'spanʃən], there is a fly in the ointment, datum['deitəm], data[deitə], horny[hɔːni], put forward[pʊtfɔ:wəd], desire[di'zaiə(r)], no longer, so far so good, truncate[trʌnkeit], cut off[kʌtɔf], modulo['mɔduləʊ], moduli['mɔdulai], score[skɔː(r)], crucial[kru:ʃl], rely on[rilaiɔn].

**October-26th-09. First Pattern Recognition Algorithms. Voluptuous (III). ** I firmly decide to avert my eyes from my female students as they all seem teasing me. Somehow I find that game very dangerous. Even worse, it might not be their game but my fevered imagination's. If so, why is she betraying me? No, no, that cannot be. They are playing with me, they are mocking at me. It must be that.

I look at the boys and notice one of them. I've seen him since class started, but suddenly, and by no apparent reason, he looks extremely handsome and irresistible to me. He is neither tall nor short but of the ideal height. He's got rosy cheeks, his face is alert and lively, with a sharp chin and shrewd little eyes. His body is harmoniously proportioned, the daintiness of his hands standing out conspicuously. He looks magnificently and enormously sensual. I feel vexed, losing my composure. I clear my throat a few times as to make a pause, get my strength back and carry on with my explanation. For a few minutes everything seems to be back to normal. My attention is riveted by the material I have to explain. I cover in detail the probabilistic analysis of the naive string matching algorithm. They don't seem to have problems with the random variables involved. They seem to appreciate the use of probabilistic tools in computer science.

Out of the corner of my eye I notice something. Another male student is undeniably staring at me, grinning from ear to ear. What's going on in this classroom? This student is burly -I discreetly examine him while talking- smooth-cheeked and with absolutely no body hair, which gives his skin an amazing shining quality. The smoothness of his skin must be to die for. I can imagine such smoothness under my lips. Again, I strongly shake my head in wonder and disbelief.

I interrupt my explanation. I remain quiet for almost a minute, thinking about the meaning of all this. I realize they are waiting for some prompting signal, but I don't know which one.

(To be continued...)

Difficult words: lead[li:d], handicap['hændicæap], nuts[nʌts], browse[braʊz].

**October-30th-09. First Pattern Recognition Algorithms. Voluptuous (IV).** I am still wandering up and down the classroom while they are staring at me. What are they expecting from me? My head is boiling and my brain is so full of sensations, feelings and ideas that it feels like it is going to burst. All of the sudden, a quote from Shakespeare crosses my mind. I catch it at full strength in the midst of the pandemonium. It is now my mind. It reads

## The blood of youth burns not with such excess as gravity's revolt to wantonness.

I savour each word. Like Proust's madeleine this quote triggers fond, vivid, long-forgotten memories, memories of fundamental truths. I will not be gravity revolting to wantonness. I will not smash the blood of youth on behalf gravity. The grand battle of life is to teach blood limits, to tame it and make it understand man does not live by bread alone. But if blood has never been sated with bread, how can it know of any temperance?

I face them all and with a big smile lift my arms. My eyes are shinning bright. I pronounce each word with exceeding joy.

### The flesh is proud.

Let us start this Saturnalia.

(To be continued...)

Difficult words: transcription[træn'skripʃn], factor['fæktə(r)], bind[baind], core[kɔː(r)], portion[pɔːrʃn], utilize[ju:təlaiz], collision[kə'liʒn].