Η κατασκευή ενός ολοκληρωμένου κβαντικού υπολογιστή αποτελεί μια πρόκληση για τη σύγχρονη επιστήμη. Ο κβαντικός υπολογιστής μας δίνει την ελπίδα πως κάποια στιγμή στο κοντινό μέλλον, θα είμαστε σε θέση να λύνουμε προβλήματα ταχύτερα και πιο αποδοτικά από ότι κάνει ένας κλασσικός υπολογιστής σήμερα. Για παράδειγμα, ο κβαντικός αλγόριθμος παραγοντοποίησης του Shor [3] πετυχαίνει εκθετική επιτάχυνση έναντι του κλασσικού, κάτι που σημαίνει πως η χρήση του πρωτόκολλου κρυπτογράφησης RSA δεν θα είναι όσο ασφαλής είναι σήμερα. Αυτό θα έχει ως αποτέλεσμα μεγάλες αλλαγές στις επικοινωνίες και στις συναλλαγές στο προσεχές μέλλον. Στην παρούσα διπλωματική εργασία θα περιγράψουμε τις αρχές που πρέπει να πληρεί ένα κβαντικό σύστημα για να θεωρηθεί κβαντικός υπολογιστής, πώς υλοποιούμε ένα qubit που είναι η μονάδα πληροφορίας του και τέλος θα μιλήσουμε για το πώς κωδικοποιούμε την κβαντική πληροφορία ώστε να είμαστε σε θέση να τη διορθώσουμε. Αρχίζουμε με τη διατύπωση των αρχών της κβαντικής μηχανικής , όπως προκύπτουν από την πειραματική διαδικασία. Συνεχίζουμε με την υπεραγωγιμότητα, το φαινόμενο που μας επιτρέπει να χειριζόμαστε μακροσκοπικά της κβαντικές ιδιότητες της ύλης, όπως και κάποια ακόμα φαινόμενα, όπως αυτό του Meissner, που μας δίνουν τη δυνατότητα να δημιουργήσουμε το κυκλώμα που υλοποιεί το qubit. Τέλος, περιγράφουμε θεωρητικά ένα καθολικό σύνολο από κβαντικές πύλες και τα κυκλώματα διόρθωσης λαθών κβαντικού κώδικα. / The construction of an integrated quantum computer is a challenge for modern science. The quantum computer gives us hope that sometime in the near future, we will be able to solve problems faster and more efficiently than does a conventional computer today. For example, the Shor's quantum algorithm for factoring [3] gave exponential acceleration compared to the classical one, which means that the use of RSA encryption protocol will not be safe as it is today. This will result large changes in communications and transactions in the near future. In this paper we describe the principles that must meet a quantum system to be considered as a quantum computer, how do we implement a qubit which is the unit of information, and finally we'll talk about how we encode quantum information in order to be able to fix it . We begin with the formulation of the principles of quantum mechanics, derived from the experimental procedure. We continue with the superconductivity phenomenon that allows us to manipulate the macroscopic quantum properties of matter, and even some phenomena such as the Meissner, who enable us to create a circuit that implements the qubit. Finally, we describe theoretically a universal set of quantum gates and circuits of error correcting quantum code.

The recent renaissance of one particular class of error-correcting codes called low-density parity-check (LDPC) codes has revolutionized the area of communications leading to the so-called field of modern coding theory. At the heart of this theory lies the fact that LDPC codes can be efficiently decoded by an iterative inference algorithm known as belief propagation (BP) which operates on a graphical model of a code. With BP decoding, LDPC codes are able to achieve an exceptionally good error-rate performance as they can asymptotically approach Shannon's capacity. However, LDPC codes under BP decoding suffer from the error floor phenomenon, an abrupt degradation in the error-rate performance of the code in the high signal-to-noise ratio region, which prevents the decoder from achieving very low error-rates. It arises mainly due to the sub-optimality of BP decoding on finite-length loopy graphs. Moreover, the effects of finite precision that stem from hardware realizations of BP decoding can further worsen the error floor phenomenon. Over the past few years, the error floor problem has emerged as one of the most important problems in coding theory with applications now requiring very low error rates and faster processing speeds. Further, addressing the error floor problem while taking finite precision into account in the decoder design has remained a challenge. In this dissertation, we introduce a new paradigm for finite precision iterative decoding of LDPC codes over the binary symmetric channel (BSC). These novel decoders, referred to as finite alphabet iterative decoders (FAIDs), are capable of surpassing the BP in the error floor region at a much lower complexity and memory usage than BP without any compromise in decoding latency. The messages propagated by FAIDs are not quantized probabilities or log-likelihoods, and the variable node update functions do not mimic the BP decoder. Rather, the update functions are simple maps designed to ensure a higher guaranteed error correction capability which improves the error floor performance. We provide a methodology for the design of FAIDs on column-weight-three codes. Using this methodology, we design 3-bit precision FAIDs that can surpass the BP (floating-point) in the error floor region on several column-weight-three codes of practical interest. While the proposed FAIDs are able to outperform the BP decoder with low precision, the analysis of FAIDs still proves to be a difficult issue. Furthermore, their achievable guaranteed error correction capability is still far from what is achievable by the optimal maximum-likelihood (ML) decoding. In order to address these two issues, we propose another novel class of decoders called decimation-enhanced FAIDs for LDPC codes. For this class of decoders, the technique of decimation is incorporated into the variable node update function of FAIDs. Decimation, which involves fixing certain bits of the code to a particular value during decoding, can significantly reduce the number of iterations required to correct a fixed number of errors while maintaining the good performance of a FAID, thereby making such decoders more amenable to analysis. We illustrate this for 3-bit precision FAIDs on column-weight-three codes and provide insights into the analysis of such decoders. We also show how decimation can be used adaptively to further enhance the guaranteed error correction capability of FAIDs that are already good on a given code. The new adaptive decimation scheme proposed has marginally added complexity but can significantly increase the slope of the error floor in the error-rate performance of a particular FAID. On certain high-rate column-weight-three codes of practical interest, we show that adaptive decimation-enhanced FAIDs can achieve a guaranteed error-correction capability that is close to the theoretical limit achieved by ML decoding.

The hard-disk storage industry is at a critical time as the current technologies are incapable of achieving densities beyond 500 Gb/in2, which will be reached in a few years. Many radically new storage architectures have been proposed, which along with advanced signal processing algorithms are expected to achieve much higher densities. In this dissertation, various signal processing algorithms are developed to improve the performance of current and next-generation magnetic storage systems.Low-density parity-check (LDPC) error correction codes are known to provide excellent performance in magnetic storage systems and are likely to replace or supplement currently used algebraic codes. Two methods are described to improve their performance in such systems. In the first method, the detector is modified to incorporate auxiliary LDPC parity checks. Using graph theoretical algorithms, a method to incorporate maximum number of such checks for a given complexity is provided. In the second method, a joint detection and decoding algorithm is developed that, unlike all other schemes, operates on the non-binary channel output symbols rather than input bits. Though sub-optimal, it is shown to provide the best known decoding performance for channels with memory more than 1, which are practically the most important.This dissertation also proposes a ternary magnetic recording system from a signal processing perspective. The advantage of this novel scheme is that it is capable of making magnetic transitions with two different but predetermined gradients. By developing optimal signal processing components like receivers, equalizers and detectors for this channel, the equivalence of this system to a two-track/two-head system is determined and its performance is analyzed. Consequently, it is shown that it is preferable to store information using this system, than to store using a binary system with inter-track interference. Finally, this dissertation provides a number of insights into the unique characteristics of heat-assisted magnetic recording (HAMR) and two-dimensional magnetic recording (TDMR) channels. For HAMR channels, the effects of laser spot on transition characteristics and non-linear transition shift are investigated. For TDMR channels, a suitable channel model is developed to investigate the two-dimensional nature of the noise.

The hydrophobic plasma membrane constitutes an indispensable barrier for cells in living animals. Albeit being pivotal for the maintenance of cells, the inability to cross the plasma membrane is still one of the major obstacles to overcome in order to progress current drug development. A group of substances, with restricted access to the interior of cells, which has shown great promise for future clinical use is oligonucleotides that are exploited to interfere with gene expression. Short interfering RNAs that are utilized to confer gene silencing and splice correcting oligonucleotides, applied for the manipulation of splicing patterns, are two classes of oligonucleotides that have been explored in this thesis. Cell-penetrating peptides (CPPs) are a class of peptides that has gained increasing focus in last years. This ensues as a result of their remarkable ability to convey various, otherwise impermeable, macromolecules across the plasma membrane of cells in a relatively non-toxic fashion. This thesis aims at further characterizing well-established, and newly designed, CPPs in terms of toxicity, delivery efficacy, and internalization mechanism. Our results demonstrate that different CPPs display different toxic profiles and that cargo conjugation alters the toxicity and uptake levels. Furthermore, we confirm the involvement of endocytosis in translocation of CPPs, and in particular the importance of macropinocytosis. All tested peptides facilitate the delivery of splice correcting oligonucleotides with varying efficacy, the newly designed CPP, M918, being the most potent. Finally we conclude that by promoting endosomolysis, by exploring new CPPs with improved endosomolytic properties, the biological response increases significantly. In conclusion, we believe that these results will facilitate the development of new CPPs with improved delivery properties that could be used for transportation of oligonucleotides in clinical settings.

Darbe atlikta teorinė taisyklingos kūno laikysenos sampratos, laikysenos sutrikimų paplitimo, priežasčių, pasekmių, korekcinių priemonių analizė. Iškelta hipotezė, kad sistemingas pratimų su terapiniais kamuoliais integravimas į judesio korekcijos pratybas 5-6 metų vaikams, turintiems laikysenos sutrikimų, daro teigiamą poveikį jų kūno laikysenai. Pratimų su terapiniais kamuoliais taikymas laikysenos sutrikimų profilaktikoje ir korekcijoje yra efektyvesnis nei tradiciniai fiziniai pratimai. Buvo atliktas eksperimentas, kurio tikslas - nustatyti ir įvertinti pratimų su terapiniais kamuoliais poveikį 5-6 metų vaikų laikysenai. Atlikta statistinė (aprašomoji dažnių, vidurkių, Mann’o ir Whitney U-testo, Wilcoxon’o teso, Spirmeno koreliacijos koeficiento) duomenų analizė. Tyrime dalyvavo Šiaulių rajono Kairių lopšelio-darželio ,,Spindulėlis” ir Šiaulių lopšelio-darželio ,,Varpelis” 5-6 metų vaikai, turintys laikysenos sutrikimų. Empirinėje dalyje nagrinėjami 5-6 metų vaikų laikysenos ypatumai, analizuojami laikysenos, kaulų ir raumenų funkcinės būklės pokyčiai. Svarbiausios empirinio tyrimo išvados: 1. Tyrimo rezultatai parodė, kad judesio korekcijos pratybos taikant pratimus su terapiniais kamuoliais turėjo teigiamą poveikį 5-6 metų vaikų kūno laikysenai. Eksperimentinės grupės tiriamųjų kūno laikysena patikimai (p≤0,05) pagerėjo po eksperimento ir statistiškai reikšmingai skyrėsi nuo kontrolinės grupės tiriamųjų kūno laikysenos (p≤0,05). 2. Visų tiriamųjų kaulų ir raumenų... [toliau žr. visą tekstą] / In the present master’s thesis, there is performed theoretical analysis of the concept of correct body posture disorders, their reasons, consequences and corrective means. In the thesis, there was raised a hypothesis that systematic integration of exercises with therapeutic balls into practice of movement correction to 5-6 years aged children with posture disorders makes positive effect on their body posture. Application of exercises with therapeutic balls in prophylaxis and correction of posture disorders is more efficient than conventional physical exercises. An experiment was performed. The purpose of the experiment was to determine and assess the effect to the exercises with therapeutic balls on the posture of 5-6 years aged children. A statistical analysis (descriptive of frequencies, averages, Mann and Whitney’s U-test, Wilcoxon’s test, Spirmen’s correlation coefficient) of data was performed. 5-6 years aged children with posture disorders from Kairiai kindergarten “Spindulėlis” and from Šiauliai kindergarten “Varpelis” participated in the research. Peculiarities of posture of 5-6 years aged children are considered in the empiric part of the thesis. There are also analysed changes of functional condition of posture, bones and muscles. The main conclusions of the empiric research are the following: 1. The results of the research demonstrated that practice of movement correction applying exercises with therapeutic balls had positive effect on posture of 5-6 years old... [to full text]

Darbe atlikta teorinė priešmokyklinio amžiaus vaikų psichomotorikos analizė. Iškelta hipotezė, kad kamuolių terapijos programa, taikoma kalbos, kalbėjimo ir komunikacijos sutrikimų turintiems vaikams, turi teigiamos įtakos ugdytinių laikysenos ir koordinacinių judesių rodikliams bei kalbėjimo funkcijoms. Penkių mėnesių trukmės eksperimento metu buvo atliekami testavimo tyrimai, kurių tikslas – ištirti ir palyginti eksperimentinės ir kontrolinės grupių tiriamųjų laikysenos ir koordinacinių judesių išsivystymo lygį bei nustatyti kamuolių terapijos poveikį eksperimentinės grupės vaikų motorikos bei kalbinių funkcijų lavinimui. Atlikta statistinė (vidurkių, koreliacijos ir Chi kvadrato) duomenų analizė. Eksperimente dalyvavo 40 šešerių metų amžiaus vaikų, turinčių kalbos, kalbėjimo ir komunikacijos sutrikimų, iš dviejų Šiaulių lopšelių–darželių. Empirinėje dalyje nagrinėjami priešmokyklinio amžiaus vaikų kalbos, kalbėjimo ir komunikacijų sutrikimai, laikysenos ir koordinacinių įgūdžių išsivystymo lygis, šių sričių tarpusavio sąsajos bei korekcinių pratybų su terapiniais kamuoliais įtaka tiriamųjų psichomotoriniam vystimuisi. Svarbiausios empirinio tyrimo išvados: 1. Tirtiems vaikams būdingi nežymūs kalbos, kalbėjimo ir komunikacijos sutrikimai. Vyrauja fonetinės ir fonologinės kilmės kalbos sutrikimai. Pradinio laikysenos ir koordinacinių funkcijų tyrimo rezultatai parodė, kad priešmokyklinio amžiaus vaikai pasižymi pakankamai prasta laikysenos simetrija, koordinacijos ir... [toliau žr. visą tekstą] / This work contains the theoretical analysis of psycho-motorics of pre-school children. The hypothesis that a ball therapy program applied to children with linguistic, speaking and communication disorders had a positive influence on their postural control, coordination movements and speaking functions was put forward. During the five months lasted experiment the research was done. The aim of this research was to explore and compare the level in the posture development and coordination movements of examined children in experimental and control groups as well as determine the influence of the ball therapy on the development of motorics and speaking functions of children in an experimental group. It was done the statistical analysis of the results (averages, correlation and Chi square). 40 six-year-old children with linguistic, speaking and communication disorders from 2 kindergartens took part in this experiment. The empirical part provides the analysis of pre-school children’s linguistic, speaking and communicative disorders, the level of development of a posture and coordination skills, links between these areas and effect of correction exercises with therapeutic balls on children’s psycho-motor development. Here are the main conclusions of the empirical research: 1. Examined children have small linguistic, speaking and communicative disorders. Phonetic and phonological disorders are the most common. The results of the research into initial posture and coordination functions... [to full text]

In this paper, we recover the amplitude of a seismic image by approximating the normal (demigrationmigration) operator. In this approximation, we make use of the property that curvelets remain invariant under the action of the normal operator. We propose a seismic amplitude recovery method that employs an eigenvalue like decomposition for the normal operator using curvelets as eigen-vectors. Subsequently, we propose an approximate non-linear singularity-preserving solution to the least-squares seismic imaging problem with sparseness in the curvelet domain and spatial continuity constraints. Our method is tested with a reverse-time ’wave-equation’ migration code simulating the acoustic wave equation on the SEG-AA salt model.

Simultaneous prompting is an errorless learning strategy designed to reduce the number of errors students make; however, research has shown a disparity in the number of errors students make during instructional versus probe trials. This study directly examined the effects of error correction versus no error correction during probe trials on the effectiveness and efficiency of simultaneous prompting on the acquisition of sight words by three middle school students with moderate intellectual disabilities. A single-case adapted alternating treatments design (Sindelar, Rosenberg, & Wilson, 1985) was employed to examine the effects of error correction during probe trials in order to reduce error rates. A functional relation was established for two of the three students for the use of error correction during probe sessions to reduce error rates. Error correction during assessment probes required fewer sessions to criterion, resulted in fewer probe errors, resulted in a higher percentage of correct responding on the next subsequent trial, and required less total probe time. For two of the three students, probes with error correction resulted in a more rapid acquisition rate requiring fewer sessions to criterion.

This work addresses issues in the automatic preprocessing of historical German input text for use by conventional natural language processing techniques. Conventional techniques cannot adequately account for historical input text due to conventional tools' reliance on a fixed application-specific lexicon keyed by contemporary orthographic surface form on the one hand, and the lack of consistent orthographic conventions in historical input text on the other. Historical spelling variation is treated here as an error-correction problem or "canonicalization" task: an attempt to automatically assign each (historical) input word a unique extant canonical cognate, thus allowing direct application-specific processing (tagging, parsing, etc.) of the returned canonical forms without need for any additional application-specific modifications. In the course of the work, various methods for automatic canonicalization are investigated and empirically evaluated, including conflation by phonetic identity, conflation by lemma instantiation heuristics, canonicalization by weighted finite-state rewrite cascade, and token-wise disambiguation by a dynamic Hidden Markov Model. / Diese Arbeit behandelt Themen der automatischen Vorverarbeitung historischen deutschen Textes für die Weiterverarbeitung durch konventionelle computerlinguistische Techniken. Konventionelle Techniken können historischen Text wegen des hohen Grads an graphematischer Variation in solchem Text ohne eine solche Vorverarbeitung nicht zufriedenstellend behandeln. Variation in der historischen Rechtschreibung wird hier als Fehlerkorrekturproblem oder "Kanonikalisierungsaufgabe" behandelt: ein Versuch, jedem (historischen) Eingabewort eine eindeutige extante Äquivalente zuzuordnen; so können konventionelle Techniken ohne weitere Modifikation direkt auf den gelieferten kanonischen Formen arbeiten. Verschiedene Methoden zur automatischen Kanonikalisierung werden im Rahmen dieser Arbeit untersucht, unter anderem Konflation durch phonetische Identität, Konflation durch Lemma-Instanziierungsheuristiken, Kanonikalisierung durch eine Kaskade gewichteter endlicher Transduktoren, und Disambiguiierung von Konflationskandidaten durch ein dynamisches Hidden Markov Modell.

Darbo tikslas - atskleisti sergančiųjų šizofrenija psichosocialinio funkcionavimo gerinimo galimybes taikant psichologinės korekcijos metodus. Šizofrenija serga vidutiniškai 1 proc. pasaulio žmonių. Remiantis Valstybinio psichikos sveikatos centro (2006) duomenimis, šizofrenija gali susirgti bet kuris asmuo nepriklausomai nuo tautybės, socialinės padėties ar išsilavinimo. Šizofrenija yra sunkus psichikos sutrikimas arba grupė tokių sutrikimų, kuriems būdingi psichozės simptomai, pažeidžiantys žmogaus elgesį ir suvokimą. Tai polietiologinis psichikos sutrikimas. Su šizofrenija susijusios priežastys gali būti: virusinė infekcija iki gimimo, hipoksija (deguonies trūkumas), apsinuodijimai, cheminių medžiagų organizme disbalansas, neuromediatorių pusiausvyros sutrikimas, smegenų kraujotakos sutrikimai, psichosocialinis stresas ir tam tikri šeimos modeliai. Sergant šizofrenija pažeidžiamos šios psichikos veiklos sferos: valia, mąstymas ir emocijos. Su šizofrenija gali atsirasti suicidinių ketinimų. Savižudybės rizika didžiausia pirmuosius 6 metus, po šizofrenijos diagnozės nustatymo. V.Fenton (1997) teigimu, galimas ryšys tarp šizofrenijos spektro sutrikimų, teigiamų ir neigiamų simptomų ir suicidinio elgesio. Sergantiems šizofrenija kyla daug psichosocialinių problemų. Tai: nerimas, depresija, socialinė izoliacija, karjeros planavimo ir įsidarbinimo problemos. Sergantys šizofrenija asmenys turi tinkamai adaptuotis socialinėje aplinkoje. Sergantiems šizofrenija psichikos būklei... [toliau žr. visą tekstą] / The aim - to reveal psychosocial functioning of patients with schizophrenia, improvement in the context of psychological adjustment methods. Schizophrenia affects approximately 1 percent people in the world. According to the State Mental Health Centre (2006) show that schizophrenia may suffer from any person, regardless of nationality, social status or education. Schizophrenia is a severe mental disorder or group of such disorders characterized by psychotic symptoms, which violate the human behavior and perception. This Polyetiological mental disorder. With schizophrenia related reasons may be: a viral infection before birth, hypoxia (oxygen deficiency), poisoning, chemical imbalances in the body, a neurotransmitter imbalance, cerebrovascular disorders, psychosocial stress and some family models. Schizophrenia vulnerable to this mental activity spheres: the will, thought and emotion. With schizophrenia can lead to suicidal intent. Highest risk of suicide during the first 6 years after the diagnosis of schizophrenia. Fenton MV (1997) argues that a possible link between schizophrenia spectrum disorders, positive and negative symptoms and suicidal behavior. Patients with schizophrenia have a lot of psychosocial problems. These include: anxiety, depression, social isolation, career planning and employment issues. Persons with schizophrenia have a duty to adapt to the social environment. With schizophrenia and mental status assessment of disease severity of the psychological... [to full text]