985 resultados para Time Dependant Multiple Random Cipher Code (TDMRC Code)
Resumo:
The 22 MIMO profiles included in Mobile WiMAX specifications are Alamoutis space-time code (STC) fortransmit diversity and spatial multiplexing (SM). The former hasfull diversity and the latter has full rate, but neither of them hasboth of these desired features. An alternative 22 STC, which is both full rate and full diversity, is the Golden code. It is the best known 22 STC, but it has a high decoding complexity. Recently, the attention was turned to the decoder complexity, this issue wasincluded in the STC design criteria, and different STCs wereproposed. In this paper, we first present a full-rate full-diversity22 STC design leading to substantially lower complexity ofthe optimum detector compared to the Golden code with only a slight performance loss. We provide the general optimized form of this STC and show that this scheme achieves the diversitymultiplexing frontier for square QAM signal constellations. Then, we present a variant of the proposed STC, which provides a further decrease in the detection complexity with a rate reduction of 25% and show that this provides an interesting trade-off between the Alamouti scheme and SM.
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Multiple-input multiple-output (MIMO) techniques have become an essential part of broadband wireless communications systems. For example, the recently developed IEEE 802.16e specifications for broadband wireless access include three MIMOprofiles employing 22 space-time codes (STCs), and two of these MIMO schemes are mandatory on the downlink of Mobile WiMAX systems. One of these has full rate, and the other has full diversity, but neither of them has both of the desired features. The third profile, namely, Matrix C, which is not mandatory, is both a full rate and a full diversity code, but it has a high decoder complexity. Recently, the attention was turned to the decodercomplexity issue and including this in the design criteria, several full-rate STCs were proposed as alternatives to Matrix C. In this paper, we review these different alternatives and compare them to Matrix C in terms of performances and the correspondingreceiver complexities.
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Silver Code (SilC) was originally discovered in [14] for 22 multiple-input multiple-output (MIMO) transmission. It has non-vanishing minimum determinant 1/7, slightly lower than Golden code, but is fast-decodable, i.e., it allows reduced-complexity maximum likelihood decoding [57]. In this paper, we present a multidimensional trellis-coded modulation scheme for MIMO systems [11] based on set partitioning of the Silver Code, named Silver Space-Time Trellis Coded Modulation (SST-TCM). This lattice set partitioning is designed specifically to increase the minimum determinant. The branches of the outer trellis code are labeled with these partitions. Viterbi algorithm is applied for trellis decoding, while the branch metrics are computed by using a sphere-decoding algorithm. It is shown that the proposed SST-TCM performs very closely to the Golden Space-Time Trellis Coded Modulation (GST-TCM) scheme, yetwith a much reduced decoding complexity thanks to its fast-decoding property.
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This paper presents several algorithms for joint estimation of the target number and state in a time-varying scenario. Building on the results presented in [1], which considers estimation of the target number only, we assume that not only the target number, but also their state evolution must be estimated. In this context, we extend to this new scenario the Rao-Blackwellization procedure of [1] to compute Bayes recursions, thus defining reduced-complexity solutions for the multi-target set estimator. A performance assessmentis finally given both in terms of Circular Position Error Probability - aimed at evaluating the accuracy of the estimated track - and in terms of Cardinality Error Probability, aimed at evaluating the reliability of the target number estimates.
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The computer code system PENELOPE (version 2008) performs Monte Carlo simulation of coupledelectron-photon transport in arbitrary materials for a wide energy range, from a few hundred eV toabout 1 GeV. Photon transport is simulated by means of the standard, detailed simulation scheme.Electron and positron histories are generated on the basis of a mixed procedure, which combinesdetailed simulation of hard events with condensed simulation of soft interactions. A geometry packagecalled PENGEOM permits the generation of random electron-photon showers in material systemsconsisting of homogeneous bodies limited by quadric surfaces, i.e., planes, spheres, cylinders, etc. Thisreport is intended not only to serve as a manual of the PENELOPE code system, but also to provide theuser with the necessary information to understand the details of the Monte Carlo algorithm.
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The transportation system is in demand 24/7 and 365 days a year irrespective of neither the weather nor the conditions. Iowas transportation system is an integral and essential part of society serving commerce and daily functions of all Iowans across the state. A high quality transportation system serves as the artery for economic activity and, the condition of the infrastructure is a key element for our future growth opportunities. A key component of Iowas transportation system is the public roadway system owned and maintained by the state, cities and counties. In order to regularly re-evaluate the conditions of Iowas public roadway infrastructure and assess the ability of existing revenues to meet the needs of the system, the Iowa Department of Transportations 2006 Road Use Tax Fund (RUTF) report to the legislature included a recommendation that a study be conducted every five years. That recommendation was included in legislation adopted in 2007 and signed into law. The law specifically requires the following (2011 Iowa Code Section 307.31): The department shall periodically review the current revenue levels of the road use tax fund and the sufficiency of those revenues for the projected construction and maintenance needs of city, county, and state governments in the future. The department shall submit a written report to the general assembly regarding its findings by December 31 every five years, beginning in 2011. The report may include recommendations concerning funding levels needed to support the future mobility and accessibility for users of Iowa's public road system. The department shall evaluate alternative funding sources for road maintenance and construction and report to the general assembly at least every five years on the advantages and disadvantages and the viability of alternative funding mechanisms. Consistent with this requirement, the Iowa Department of Transportation (DOT) has prepared this study. Recognizing the importance of actively engaging with the public and transportation stakeholders in any discussion of public roadway conditions and needs, Governor Terry E. Branstad announced on March 8, 2011, the creation of, and appointments to, the Governors Transportation 2020 Citizen Advisory Commission (CAC). The CAC was tasked with assisting the Iowa DOT as they assess the condition of Iowas roadway system and evaluate current and future funding available to best address system needs. In particular the CAC was directed to gather input from the public and stakeholders regarding the condition of Iowas public roadway system, the impact of that system, whether additional funding is needed to maintain/improve the system, and, if so, what funding mechanisms ought to be considered. With this input, the CAC prepared a report and recommendations that were presented to Governor Branstad and the Iowa DOT in November 2011 for use in the development of this study. The CACs report is available at www.iowadot.gov/transportation2020/pdfs/CAC%20REPORT%20FINAL%20110211.pdf. The CACs report was developed utilizing analysis and information from the Iowa DOT. Therefore, the report forms the basis for this study and the two documents are very similar. Iowa is fortunate to have an extensive public roadway system that provides access to all areas of the state and facilitates the efficient movement of goods and people. However, it is also a tremendous challenge for the state, cities and counties to maintain and improve this system given flattening revenue, lost buying power, changing demands on the system, severe weather, and an aging system. This challenge didnt appear overnight and for the last decade many studies have been completed to look into the situation and the legislature has taken significant action to begin addressing the situation. In addition, the Iowa DOT and Iowas cities and counties have worked jointly and independently to increase efficiency and streamline operations. All of these actions have been successful and resulted in significant changes; however, it is apparent much more needs to be done. A well-maintained, high-quality transportation system reduces transportation costs and provides consistent and reliable service. These are all factors that are critical in the evaluation companies undertake when deciding where to expand or locate new developments. The CAC and Iowa DOT heard from many Iowans that additional investment in Iowas roadway system is vital to support existing jobs and continued job creation in the state of Iowa. Beginning June 2011, the CAC met regularly to review material and discuss potential recommendations to address Iowas roadway funding challenges. This effort included extensive public outreach with meetings held in seven locations across Iowa and through a Transportation 2020 website hosted by the Iowa DOT (www.iowadot.gov/transportation2020). Over 500 people attended the public meetings held through the months of August and September, with 198 providing verbal or written comment at the meetings or through the website. Comments were received from a wide array of individuals. The public comments demonstrated overwhelming support for increased funding for Iowas roads. Through the public input process, several guiding principles were established to guide the development of recommendations. Those guiding principles are: Additional revenues are restricted for road and bridge improvements only, like 95 percent of the current state road revenue is currently. This includes the fuel tax and registration fees. State and local governments continue to streamline and become more efficient, both individually and by looking for ways to do things collectively. User fee concept is preserved, where those who use the roads pay for them, including nonresidents. Revenue-generating methods equitable across users. Increase revenue generating mechanisms that are viable now but begin to implement and set the stage for longer-term solutions that bring equity and stability to road funding. Continue Iowas long standing tradition of state roadway financing coming from pay-as-you-go financing. Iowa must not fall into the situation that other states are currently facing where the majority of their new program dollars are utilized to pay the debt service of past bonding. Based on the analysis of Iowas public roadway needs and revenue and the extensive work of the Governors Transportation 2020 Citizen Advisory Commission, the Iowa DOT has identified specific recommendations. The recommendations follow very closely the recommendations of the CAC (CAC recommendations from their report are repeated in Appendix B). Following is a summary of the recommendations which are fully documented beginning on page 21. 1. Through a combination of efficiency savings and increased revenue, a minimum of $215 million of revenue per year should be generated to meet Iowas critical roadway needs. 2. The Code of Iowa should be changed to require the study of the sufficiency of the states road funds to meet the road systems needs every two years instead of every five years to coincide with the biennial legislative budget appropriation schedule. 3.Modify the current registration fee for electric vehicles to be based on weight and value using the same formula that applies to most passenger vehicles. 4.Consistent with existing Code of Iowa requirements, new funding should go to the TIME-21 Fund up to the cap ($225 million) and remaining new funding should be distributed consistent with the Road Use Tax Fund distribution formula. 5.The CAC recommended the Iowa DOT at least annually convene meetings with cities and counties to review the operation, maintenance and improvement of Iowas public roadway system to identify ways to jointly increase efficiency. In direct response to this recommendation, Governor Branstad directed the Iowa DOT to begin this effort immediately with a target of identifying $50 million of efficiency savings that can be captured from the over $1 billion of state revenue already provided to the Iowa DOT and Iowas cities and counties to administer, maintain and improve Iowas public roadway system. This would build upon past joint and individual actions that have reduced administrative costs and resulted in increased funding for improvement of Iowas public roadway system. Efficiency actions should be quantified, measured and reported to the public on a regular basis. 6.By June 30, 2012, Iowa DOT should complete a study of vehicles and equipment that use Iowas public roadway system but pay no user fees or substantially lower user fees than other vehicles and equipment.
Resumo:
Cooperative transmission can be seen as a "virtual" MIMO system, where themultiple transmit antennas are in fact implemented distributed by the antennas both at the source and the relay terminal. Depending on the system design, diversity/multiplexing gainsare achievable. This design involves the definition of the type of retransmission (incrementalredundancy, repetition coding), the design of the distributed space-time codes, the errorcorrecting scheme, the operation of the relay (decode&forward or amplify&forward) and thenumber of antennas at each terminal. Proposed schemes are evaluated in different conditionsin combination with forward error correcting codes (FEC), both for linear and near-optimum(sphere decoder) receivers, for its possible implementation in downlink high speed packetservices of cellular networks. Results show the benefits of coded cooperation over directtransmission in terms of increased throughput. It is shown that multiplexing gains areobserved even if the mobile station features a single antenna, provided that cell wide reuse of the relay radio resource is possible.
Resumo:
3G-radioverkon asetusten hallinnointi suoritetaan stmll radioverkkotietokantaan talletettavia parametreja. Hallinnointiohjelmistossa tuhannetradioverkon parametrit nkyvt kyttliittymkomponentteina, joita ohjelmiston kehityskaaressa jatkuvasti listn, muutetaan ja poistetaan asiakkaan tarpeidenmukaan. Parametrien lismisen toteutusprosessi on ohjelmistokehittjlle tylst ja mekaanista. Diplomityn tavoitteeksi asetettiin kehitt koodigeneraattori, joka luo kaiken toteutusprosessissa tuotetun koodin automaattisesti niist mrittelyist, jotka ovat nykynkin saatavilla. Tyss kehitetty generaattori nopeuttaa ohjelmoijan tyt eliminoimalla yhden aikaa vievn ja mekaanisen tyvaiheen. Seurauksena saadaan yhtenisemp ohjelmistokoodia ja sstetn yrityksen ohjelmistotuotannon kuluissa, kun ohjelmoijan taito voidaan keskitt vaativimpiin tehtviin.
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Lintrt de lenfant est une notion polymorphe dont les tenants et aboutissants sont difficiles cerner. A priori, nous postulions que son caractre polymorphe en permet linstrumentalisation, les acteurs sociaux cherchant, par la reprsentation quils sen font, dfendre leurs intrts. Notre mmoire prend dailleurs partie lexemple de lavant-projet de Loi modifiant le Code civil et dautres dispositions lgislatives en matire dadoption et dautorit parentale. Dans notre premier titre, il convenait ainsi de dresser lhistorique de lintrt de lenfant en tant que notion variablement volutive, de sa rception en jurisprudence et dans les lois qubcoises portant sur ladoption, son incorporation en droit commun, la suite de labrogation du concept de puissance paternelle. Nous en avons galement identifi les fondements, au travers du droit anglais, du droit international, des Chartes et du droit naturel. Les lments de dfinition du concept tant multiples, nous avons enfin cherch le conceptualiser, en dgager les bases lgales et effectuer lanalyse doctrinale et jurisprudentielle de ses critres. Puis, afin de dmontrer nos prmisses, nous avons examin, dans notre seconde partie, les discours de quelques 23 intervenants dans le cadre des consultations menes par la Commission des institutions sur lavant-projet de loi susdit. En somme, alors que les chercheurs universitaires ont une position ne cherchant pas insister sur une dimension de lintrt de lenfant convergeant vers leur mission, les propos des ordres professionnels, des groupes de pression et des organismes para-gouvernementaux sont, en revanche, leffet contraire.
Resumo:
Problme: Ma thse porte sur lidentit individuelle comme interrogation sur les enjeux personnels et sur ce qui constitue lidentification hybride lintrieur des notions concurrentielles en ce qui a trait lauthenticit. Plus prcisment, jaborde le concept des identifications hybrides en tant que zones intermdiaires pour ce qui est de lalternance de codes linguistiques et comme ngociation des espaces continuels dans leur mouvement entre les cultures et les langues. Une telle ngociation engendre des tensions et/ou apporte le lien cratif. Les tensions sont inhrentes nimporte quelle construction didentit o les lignes qui dfinissent des personnes ne sont pas spcifiques une culture ou une langue, o des notions de lidentit pure sont contestes et des codes communs de lappartenance sont compromis. Le lien cratif se produit dans les exemples o lalternance de code linguistique ou la ngociation des espaces produit le mouvement ouvert et fluide entre les codes de concurrence des rfrences et les diffrences travers les discriminations raciales, la sexualit, la culture et la langue. Les travaux que jai slectionns reprsentent une section transversale de quelques auteurs migrants provenant de la minorit en Amrique du Nord qui alternent les codes linguistiques de cette manire. Les travaux dtaillent le temps et lespace dans leur traitement de lidentit et dans la faon dont ils cernent lhybridit dans les textes suivants : The Woman Warrior de Maxine Hong Kingston (1975-76), Hunger of Memory de Richard Rodriguez (1982), Comment faire lamour avec un ngre sans se fatiguer de Dany Laferrire (1985), Borderlands/La Frontera de Gloria Anzaldu (1987), Lost in Translation de Eva Hoffman (1989), Avril ou lanti-passion de Antonio DAlfonso (1990) et Chorus of Mushrooms de Hiromi Goto (1994). Enjeux/Questions La notion de lidentification hybride est provocante comme sujet. Elle met en question lidentit pure. Cest un sujet qui a suscit beaucoup de discussions tant en ce qui a trait la littrature, la politique, la socit, la linguistique, aux communications, quau sein mme des cercles philosophiques. Ce sujet est compliqu parce quil secoue la base des espaces fixes et structurs de lidentit dans sa signification culturelle et linguistique. Par exemple, la notion de patrie na pas les reprsentations exclusives du pays dorigine ou du pays daccueil. De mme, les notions de race, dappartenance ethnique, et despaces sexuels sont parfois ngativement acceptes si elles proviennent des codes socialement admis et normaliss de lextrieur. De tels codes de la signification sont souvent dfinis par ltiquette didentification htrosexuelle et blanche. Dans lenvironnement gnralis daujourdhui, plus que jamais, une personne doit ngocier qui elle est, au sens de son appartenance soi, en tant quindividu et ce, face aux modles locaux, rgionaux, nationaux, voire mme globaux de la subjectivit. Nous pouvons interprter ce mouvement comme une srie de couches superposes de la signification. Quand nous rencontrons une personne pour la premire fois, nous ne voyons que la couche suprieure. Dailleurs, son soi intrieur est cach par de nombreuses couches superposes (voir Joseph D. Straubhaar). Toutefois, sous cette couche suprieure, on retrouve beaucoup dautres couches et tout comme pour un oignon, on doit les enlever une par une pour que lindividualit complte dune personne soit rvle et comprise. Le noyau dune personne reprsente un point de dpart crucial pour opposer qui elle tait la faon dont elle se transforme sans cesse. Sa base, ou son noyau, dpend du moment, et comprend, mais ne sy limite pas, ses origines, son environnement et ses expriences denfance, son ducation, sa notion de famille, et ses amitis. De plus, les notions damour-propre et damour pour les autres, daltruisme, sont aussi des points importants. Il y a une relation rciproque entre le soi et lautre qui tablit notre degr destime de soi. En raison de la mondialisation, notre faon de comprendre la culture, en fait, comment on consomme et dfinit la culture, devient rapidement un phnomne de dplacement. lintrieur de cette arne de culture gnralise, la faon dont les personnes sont lorigine chinoises, mexicaines, italiennes, ou autres, et poursuivent leur volution culturelle, se dfinit plus aussi facilement quavant. Approche Ainsi, ma thse explore la subjectivit hybride comme position des tensions et/ou des relations cratrices entre les cultures et les langues. Quoique je ne souhaite aucunement simplifier ni le processus, ni les questions de lauto-identification, il mapparat que la subjectivit hybride est aujourdhui une ralit croissante dans larne gnralise de la culture. Ce processus dchange est particulirement complexe chez les populations migrantes en conflit avec leur dsir de sintgrer dans les nouveaux espaces adopts, cest--dire leur pays daccueil. Ce rel dsir dappartenance peut entrer en conflit avec celui de garder les espaces originels de la culture dfinie par son pays dorigine. Ainsi, les rfrences antrieures de lidentification dune personne, les fondements de son individualit, son noyau, peuvent toujours ne pas correspondre , ou bien fonctionner harmonieusement avec, les rfrences extrieures et les couches didentification changeantes, celles quelle sapproprie du pays daccueil. Puisque nos politiques, nos religions et nos tablissements denseignement proviennent des reprsentations nationales de la culture et de la communaut, le processus didentification et la cration de son individualit extrieure sont formes par le contact avec ces tablissements. La faon dont une personne va chercher lidentification entre les espaces personnels et les espaces publics dtermine ainsi le degr de conflit et/ou de lien cratif prouv entre les modes et les codes des espaces culturels et linguistiques. Par consquent, lidentification des populations migrantes suggre que la community and culture will represent both a hybridization of home and host cultures (Straubhaar 27). Il y a beaucoup dcrits au sujet de lhybridit et des questions de lidentit et de la patrie, toutefois cette thse aborde la valeur crative de lalternance de codes culturels et linguistiques. Ce que la littrature indiquera Par consquent, la plate-forme partir de laquelle jexplore mon sujet de lhybridit flotte entre linterprtation postcoloniale de Homi Bhabha concernant le troisime espace hybride; le modle dhtroglossie de Mikhail Bakhtine qui englobent plusieurs de mes exemples; la reprsentation de Roland Barthes sur lidentit comme espace transgressif qui est un modle de rfrence et la contribution de Chantal Zabus sur le palimpseste et lalternance de codes africains. Jutilise aussi le modle de Sherry Simon portant sur lespace urbain hybride de Montral qui tablit un lien important avec la valeur des changes culturels et linguistiques, et les analyses de Janet Paterson. En effet, la faon dont elle traite la figure de lAutre dans les modles littraires au Qubec fournisse un aperu rgional et national de lidentification hybride. Enfin, lexploration du bilinguisme de Doris Sommer comme espace esthtique et mme humoristique didentification situe lhybridit dans une espace de rencontre crative. Consquence Mon approche dans cette thse ne prtend pas rsoudre les problmes qui peuvent rsulter des plates-formes de la subjectivit hybride. Pour cette raison, jvite daborder toute approche politique ou nationaliste de lidentit qui rfute lidentification hybride. De la mme faon, je namne pas de discussion approfondie sur les questions postcoloniales. Le but de cette thse est de dmontrer quel point la subjectivit hybride peut tre une zone de relation cratrice lorsque lalternance de codes permet des changes de communication plus intimes entre les cultures et les langues. Cest un espace qui devient crateur parce quil favorise une attitude plus ouverte vis--vis les diffrents champs qui passent par la culture, aussi bien la langue, que la sexualit, la politique ou la religion. Les zones hybrides de lidentification nous permettent de contester les traditions dpasses, les coutumes, les modes de communication et la non-acceptation, toutes choses dpasses qui emprisonnent le dsir et empchent dexplorer et dadopter des codes en dehors des normes et des modles de la culture contenus dans le discours blanc, dominant, de lappartenance culturelle et linguistique mondialise. Ainsi, il appert que ces zones des relations multi-ethniques exigent plus dattention des cercles scolaires puisque la population des centres urbains travers lAmrique du Nord devient de plus en plus nourrie par dautres types de populations. Donc, il existe un besoin rel dtablir une communication sincre qui permettrait la population de bien comprendre les populations adoptes. Cest une invitation stimuler une relation plus intime de lun avec lautre. Toutefois, il est vident quune communication efficace travers les frontires des codes linguistiques, culturels, sexuels, religieux et politiques exige une ngociation continuelle. Mais une telle ngociation peut stimuler la comprhension plus juste des diffrences (culturelle ou linguistique) si des institutions acadmiques offrent des programmes dtudes intgrant davantage les littratures migrantes. Ma thse vise illustrer (par son choix littraire) lidentification hybride comme une ralit importante dans les cultures gnralises qui croissent toujours aujourdhui. Les espaces gographiques nous gardent loigns les uns des autres, mais notre consommation de produits exotiques, quils soient culturels ou non, et mme notre consommation de lautre, sest rtrcie sensiblement depuis les deux dernires dcennies et les indicateurs suggrent que ce processus nest pas une tendance, mais plutt une nouvelle manire dprouver la vie et de connatre les autres. Ainsi les marqueurs qui forment nos frontires externes, aussi bien que ces marqueurs qui nous dfinissent de lintrieur, exigent un examen minutieux de ces enjeux inter(trans)culturels, surtout si nous souhaitons nous en tenir avec succs des langues et des codes culturels prsents, tout en favorisant la diversit culturelle et linguistique. MOTS-CLS : identification hybride, mouvement ouvert, alternance de code linguistique, ngociation des espaces, tensions, connectivit crative
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Les logiciels sont de plus en plus complexes et leur dveloppement est souvent fait par des quipes disperses et changeantes. Par ailleurs, de nos jours, la majorit des logiciels sont recycls au lieu dtre dvelopps partir de zro. La tche de comprhension, inhrente aux tches de maintenance, consiste analyser plusieurs dimensions du logiciel en parallle. La dimension temps intervient deux niveaux dans le logiciel : il change durant son volution et durant son excution. Ces changements prennent un sens particulier quand ils sont analyss avec dautres dimensions du logiciel. Lanalyse de donnes multidimensionnelles est un problme difficile rsoudre. Cependant, certaines mthodes permettent de contourner cette difficult. Ainsi, les approches semi-automatiques, comme la visualisation du logiciel, permettent lusager dintervenir durant lanalyse pour explorer et guider la recherche dinformations. Dans une premire tape de la thse, nous appliquons des techniques de visualisation pour mieux comprendre la dynamique des logiciels pendant lvolution et lexcution. Les changements dans le temps sont reprsents par des heat maps. Ainsi, nous utilisons la mme reprsentation graphique pour visualiser les changements pendant lvolution et ceux pendant lexcution. Une autre catgorie dapproches, qui permettent de comprendre certains aspects dynamiques du logiciel, concerne lutilisation dheuristiques. Dans une seconde tape de la thse, nous nous intressons lidentification des phases pendant lvolution ou pendant lexcution en utilisant la mme approche. Dans ce contexte, la prmisse est quil existe une cohrence inhrente dans les vnements, qui permet disoler des sous-ensembles comme des phases. Cette hypothse de cohrence est ensuite dfinie spcifiquement pour les vnements de changements de code (volution) ou de changements dtat (excution). Lobjectif de la thse est dtudier lunification de ces deux dimensions du temps que sont lvolution et lexcution. Ceci sinscrit dans notre volont de rapprocher les deux domaines de recherche qui sintressent une mme catgorie de problmes, mais selon deux perspectives diffrentes.
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Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.This dissertation contributes to an architecture oriented code validation, error localization and optimization technique assisting the embedded system designer in software debugging, to make it more effective at early detection of software bugs that are otherwise hard to detect, using the static analysis of machine codes. The focus of this work is to develop methods that automatically localize faults as well as optimize the code and thus improve the debugging process as well as quality of the code.Validation is done with the help of rules of inferences formulated for the target processor. The rules govern the occurrence of illegitimate/out of place instructions and code sequences for executing the computational and integrated peripheral functions. The stipulated rules are encoded in propositional logic formulae and their compliance is tested individually in all possible execution paths of the application programs. An incorrect sequence of machine code pattern is identified using slicing techniques on the control flow graph generated from the machine code.An algorithm to assist the compiler to eliminate the redundant bank switching codes and decide on optimum data allocation to banked memory resulting in minimum number of bank switching codes in embedded system software is proposed. A relation matrix and a state transition diagram formed for the active memory bank state transition corresponding to each bank selection instruction is used for the detection of redundant codes. Instances of code redundancy based on the stipulated rules for the target processor are identified.This validation and optimization tool can be integrated to the system development environment. It is a novel approach independent of compiler/assembler, applicable to a wide range of processors once appropriate rules are formulated. Program states are identified mainly with machine code pattern, which drastically reduces the state space creation contributing to an improved state-of-the-art model checking. Though the technique described is general, the implementation is architecture oriented, and hence the feasibility study is conducted on PIC16F87X microcontrollers. The proposed tool will be very useful in steering novices towards correct use of difficult microcontroller features in developing embedded systems.
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Considers Sampling, Pulse Amplitude Modulation, Multiple Access, Quantisation, Pulse Coded Modulation, Manchester Line Coding, Amplitude Modulation, Double SideBand Suppressed Carrier Modulation, Quadrature Amplitude Modulation and M-ary Shift Keying.
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Greater attention has been focused on the use of CDMA for future cellular mobile communications. CA near-far resistant detector for asynchronous code-division multiple-access (CDMA) systems operating in additive white Gaussian noise (AWGN) channels is presented. The multiuser interference caused by K users transmitting simultaneously, each with a specific signature sequence, is completely removed at the receiver. The complexity of this detector grows only linearly with the number of users, as compared to the optimum multiuser detector which requires exponential complexity in the number of users. A modified algorithm based on time diversity is described. It performs detection on a bit-by-bit basis and overcomes the complexity of using a sequence detector. The performance of this detector is shown to be superior to that of the conventional receiver.
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In this paper, we consider one particularly interesting feature of the Lieber Code, which is the fact that it was drawn up by the U.S. Government to regulate the conduct of its armed forces in a civil war. In so doing, we hope to explore the extent to which there may be links between the Lieber Code and the contemporary regulation of non-international armed conflicts. In particular, we explore some similarities and contrasts between the views on the regulation of civil war that existed at the time of the drafting of the Lieber Code and the position that exists today.
