Hash tables (HTs) are used to implement various lookup schemes and they need to be efficient in terms of speed, space utilization, and power consumptions. For IP lookup, the hashing schemes are attractive due to their deterministic O(1) lookup performance and low power consumptions, in contrast to the TCAM and Trie based approaches. As the size of IP lookup table grows exponentially, scalable lookup performance is highly desirable. For next generation high-speed routers, this is a vital requirement when IP lookup remains in the critical data path and demands a predictable throughput. However, recently proposed hash schemes, like a Bloomier filter HT and a Fast HT (FHT) suffer from a number of flaws, including setup failures, update overheads, duplicate keys, and pointer overheads. In this dissertation, four novel hashing schemes and their architectures are proposed to address the above concerns by using pipelined Bloom filters and a Fingerprint filter which are designed for a memory-efficient approximate match. For IP lookups, two new hash schemes such as a Hierarchically Indexed Hash Table (HIHT) and Fingerprint-based Hash Table (FPHT) are introduced to achieve a a perfect match is assured without pointer overhead. Further, two hash mechanisms are also proposed to provide memory and power efficient lookup for packet processing applications. Among four proposed schemes, the HIHT and the FPHT schemes are evaluated for their performance and compared with TCAM and Trie based IP lookup schemes. Various sizes of IP lookup tables are considered to demonstrate scalability in terms of speed, memory use, and power consumptions. While an FPHT uses less memory than an HIHT, an FPHT-based IP lookup scheme reduces power consumption by a factor of 51 and requires 1.8 times memory compared to TCAM-based and trie-based IP lookup schemes, respectively. In dissertation, a multi-tiered packet classifier has been proposed that saves at most 3.2 times power compared to the existing parallel packet classifier. Intrinsic hashing schemes lack of high throughput, unlike partitioned Ternary Content Addressable Memory (TCAM)-based scheme that are capable of parallel lookups despite large power consumption. A hybrid CAM (HCAM) architecture has been introduced. Simulation results indicate HCAM to achieve the same throughput as contemporary schemes while it uses 2.8 times less memory and 3.6 times less power compared to the contemporary schemes.

In an attempt to slow the exhaustion of the Internet Protocol (IP) address space, Class-less Inter-Domain Routing (CIDR) was proposed and adopted. However, the decision to utilize CIDR also increases the size of the routing table, since it allows an arbitrary partitioning of the routing space. We propose a scheme to reduce the size of routing table in the CIDR context. Our approach utilizes a well-known and highly efficient heuristic to perform 2-level logic minimization in order to compress the routing table. By considering the IP routing table as a set of completely specified logic functions, we demonstrate that our technique can achieve about 25% reduction in the size of IP routing tables, while ensuring that our approach can handle routing table updates in real-time. The resulting routing table can be used with existing routers without needing any change in architecture. However, by realizing the IP routing table as proposed in this thesis, the implementation requires less complex hardware than Ternary CAM (TCAM) which are traditionally used to implement IP routing tables. The proposed architecture also reduces lookup latency by about 46%, hardware area by 9% and power consumed by 15% in contrast to a TCAM based implementation.

Microprocessors are used in a variety of systems ranging from high-performance super computers running scientific applications to battery powered cell phones performing realtime tasks. Due to the large disparity between processor clock speed and main memory access time, most modern processors include several caches, which consume more than half of the total chip area and power budget. As the performance gap between processors and memory has increased, the trend has been to increase the size of the on-chip caches. However, increasing the cache size also increases its access time and energy consumptions. This growing power dissipation problem is making traditional cooling and packaging techniques less effective thus requiring cache designers to focus more on architectural level energy efficiency than performance alone. The goal of this thesis is to propose a new cache architecture and to evaluate its efficiency in terms of miss rate, system performance, energy consumption, and area overhead. The proposed architecture employs the use of a few Ternary-CAM (TCAM) cells in the tag array to enable dynamic compression of tag entries containing contiguous values. By dynamically compressing tag entries, the number of entries in the tag array can be reduced by 2N, where N is the number of tag bits that can be compressed. The architecture described in this thesis is applicable to any cache structure that uses Content Addressable Memory (CAM) cells to store tag bits. To evaluate the effectiveness of the TCAM Enhanced Cache Architecture for a wide scope of applications, two case studies were performed ?? the L2 Data-TLB (DTLB) of a high-performance processor and the L1 instruction and data caches of a low-power embedded processor. Results indicate that a L2 DTLB implementing 3-bit tag compression can achieve 93% of the performance of a conventional L2 DTLB of the same size while reducing the on-chip energy consumption by 74% and the total area by 50%. Similarly, an embedded processor cache implementing 2-bit tag compression achieves 99% of the performance of a conventional cache while reducing the on-chip energy consumption by 33% and the total area by 10%.

>Magister Scientiae - MSc / BACKGROUND: The purpose of this study was to determine use, knowledge and attitudes towards traditional, complementary and alternative medicine (TCAM) in Botswana among people who visit public health facilities. PRIMARY AIM: The primary aim of this study was to establish the attitude towards, knowledge of and use of TCAM among patients utilizing two public health care facilities in Botswana. METHODS: The study was descriptive and quantitative in design. Data were collected using structured questionnaires in two public sector hospitals. Data included demographics of participants, current or past TCAM use, perceptions of efficacy and safety of TCAM and knowledge sources on TCAM. RESULTS: The median age of participants was 38.5 years with the youngest participants being 18 years and oldest participant 78 years. Just more than half (55%) of the participants were female.The majority of participants were single (65.6%) and about a quarter (24.4%) of participants were married. Of the study population 16 (7%) participants had no formal education and 40% had a secondary school education. The prevalence of TCAM use in the 90 study participants was found to be 48.9% of which 16.7% were currently using TCAM and 32.2% had used TCAM in the past. However, this practice could not be correlated with any particular demographic variable. TCAM was most often used either to promote overall wellness or to treat a specific health condition. The TCAM modality that was mostly used was African traditional medicine and other herbals. The majority of TCAM users were satisfied with the effects of TCAM of whom 68.4% of participants found the products very helpful. Most of the respondents (79%) reported that they perceived the products to be very safe. However, the participants were split in their willingness to recommend TCAM to another person. In terms of knowledge, most participants would not use TCAM with other medicines. Yet the majority of participants also indicated that they have never discussed TCAM use with their health care professional. Most participants have been exposed to information on TCAM from family or friends (80.6%). CONCLUSION: The prevalence of TCAM use in Botswana is similar to findings in other parts of the world. These products were primarily used for overall wellness and to treat specific diseases, but this practice could not be attributed to any particular demographic profile. The majority of TCAM users were satisfied with the effects of TCAM. Findings support a need for greater integration of allopathic medicine and CAM, as well as improved communication between patients and caregivers regarding TCAM usage.

L’incidence des cancers testiculaires a fortement augmenté au cours des 50 dernières années. Des études épidémiologiques in vitro et in vivo, ont montré que l’exposition des hommes aux perturbateurs endocriniens est impliquée dans l’initiation et la progression du cancer du testicule (Beiki et al., 2010). L’exposition fœtale à ces produits pourrait provoquer des altérations de la différenciation des cellules germinales (CGs) au cours leur développement pendant la vie fœtale. Au cours de cette thèse, nous nous sommes intéressés à déterminer le rôle des perturbateurs endocriniens œstrogéno-mimétiques en mélange sur la prolifération des cellules séminomateuses TCam-2. Nous avons identifié les voies de signalisation impliquées dans la réponse à ces produits. Nous nous sommes focalisés sur les effets d’un mélange d’alkylphénols appelé M4 (4-tert-octylphénol et le 4-nonylphénol), in vitro sur la prolifération des cellules séminomateuses TCam-2, et in vivo sur la croissance de tumeurs obtenues à partir des cellules de carcinome embryonnaire NT2/D1 xénogreffées chez la souris Nude. Dans notre étude, nous avons mis en évidence l’implication d’ERα36, une isoforme tronquée du récepteur ERα, dans la réponse au mélange d’alkylphénols, M4. Ce mélange stimule la prolifération des cellules du cancer testiculaire et l’expression du récepteur ERα36. Ces effets sont médiés par la phosphorylation de CREB via la voie PI3K-ERα36-dépendante, et aboutissent à la diminution de l’expression des gènes de la famille Dnmt3, limitant le niveau de méthylation de l’ADN. ERα36 pourrait donc constituer une cible thérapeutique dans le traitement des cancers testiculaires / In vitro and in vivo epidemiological studies showed that the exposure of men to endocrine disruptors triggers the initiation and the progression of the testis cancer (Beiki et al., 2010). The fetal exposure to these products is able to alter the differentiation of germ cells in the timing of their development during the fetal life. The aim of our study was to determine the role of an endocrine disruptor mix on the proliferation of seminoma cells TCam-2. We also identified the pathways involved. In this study, we focused on the estrogen-like effects of an alkylphenol mixture called M4 (4-tert-octylphenol and 4-nonylphenol): in vitro we measured the proliferation of TCam-2 seminoma cells after M4 exposure and in vivo, we measured the tumor growth of NT2/D1 cells xenografted into Nude mice. The results highlighted the implication of ERα36 receptor, a truncated isoform of ERα, in the response to the alkylphenol mixture M4. This mixture stimulates the cell proliferation of testicular cancer cells and the expression of the ERα36 receptor. These effects are mediated by CREB phosphorylation via the PI3K-ERα36-dependant pathway, and end by downregulation of Dnmt3 genes, thus limiting the level of DNA methylation. Therefore ERα36 appears to be a promising therapeutic target for testis cancer treatment

Les réseaux logiciels (Software Defined Network - SDN) permettent la programmation du réseau et facilitent sa configuration. Bien qu'SDN améliore les performances, il reste confronté à de multiples défis. Dans cette thèse, nous avons développé des solutions qui constituent un premier pas vers les réseaux SDN de prochaine génération. D’abord, nous présentons MINNIE qui permet la scalabilité des commutateurs SDN, qui ne supportent que quelques milliers de règles dans leur coûteuse mémoire TCAM. MINNIE comprime dynamiquement les règles de routage installées dans la TCAM, augmentant ainsi le nombre de règles pouvant être installées. Ensuite, nous abordons le problème de la dégradation de performance des flux courts avec un prototype d’ordonnancement qui exploite les statistiques des commutateurs pour diminuer leur délai de bout-en-bout. Puis, nous visons à diminuer l’intervalle de protection de 50ms qui n’est plus adapté aux applications modernes et réduit leur qualité d’expérience. Notre solution PRoPHYS s’appuie sur les statistiques des commutateurs dans les réseaux hybrides pour découvrir les pannes de liens plus vite que les solutions existantes. Enfin, nous abordons le problème de l’efficacité énergétique qui souvent mène à une dégradation de performance. Nous présentons SENAtoR, qui exploite les nœuds SDN en réseaux hybrides pour éteindre les nœuds réseau sans entraver la performance. Également, nous présentons SEaMLESS qui convertit le service fourni par une machine virtuelle inactive en une fonction de réseaux virtuelle pour permettre à l’administrateur d’utiliser les ressources bloquées tout en maintenant la disponibilité du service. / Software Defined Networking (SDN) was created to provide network programmability and ease complex configuration. Though SDN enhances network performance, it still faces multiple limitations. In this thesis, we build solutions that form a first step towards creating next-generation SDN based networks. In the first part, we present MINNIE to scale the number of rules of SDN switches far beyond the few thousands rules commonly available in TCAM memory, which permits to handle typical data center traffic at very fine grain. To do so MINNIE dynamically compresses the routing rules installed in the TCAM, increasing the number of rules that can be installed. In the second part, we tackle the degraded performance of short flows and present a coarse grained scheduling prototype that leverages SDN switch statistics to decrease their end-to-end delay. Then, we aim at decreasing the 50ms failure protection interval which is not adapted to current broadband speeds and can lead to degraded Quality of Experience. Our solution PRoPHYS leverages the switch statistics in hybrid networks to anticipate link failures by drastically decreasing the number of packets lost. Finally, we tackle the greening problem where often energy efficiency comes at the cost of performance degradation. We present SENAtoR, our solution that leverages SDN nodes in hybrid networks to turn off network devices without hindering the network performance. Finally, we present SEaMLESS that converts idle virtual machines into virtual network functions (VNF) to enable the administrator to further consolidate the data center by turning off more physical servers and reuse resources (e.g. RAM) that are otherwise monopolized.

<p>Rapid data growth nowadays makes it more critical to reduce search time to improve the performance of search-intensive applications. However, huge data size makes it more difficult to efficiently perform search operations. Representative conventional approaches to reduce search time, such as CAM and in-memory databases, are no longer efficient because of the data explosion: CMOS-based CAM has low capacity which cannot be increased through CMOS scaling, and in-memory databases have performance degradation as data size increases. As a result, we have to exploit emerging nanotechnologies to accelerate search.</p><p> </p><p>Among emerging nanotechnologies, memristors have become promising candidates to build storage structures because of high capacity, short switching time and low power consumption. However, the benefit we can obtain from these storage structures is limited by low endurance of memristors. In order to utilize the computation ability of memristors and deal with the endurance problem, we explore the design space of memristor-based storage structures.</p><p>We first propose MemCAM/MemTCAM, a configurable memristor-based CAM/TCAM design, in which we use memristors as both memory latches and logic gates. Computation ability of memristors makes it possible to perform range search and high density of memristors provides an opportunity to build MemCAM/MemTCAM with large capacity and small area. We use SPICE to model the memristor and analyze power and performance at different temperatures. The results show that it is feasible to build MemCAM and MemTCAM which have high capacity and can reduce total search time and energy consumption for search-intensive applications with huge data size.</p><p>We then propose four hybrid memristor-based storage structures, Hash-CAM, T-tree-CAM, TB+-tree, and TB+-tree-CAM, to solve the endurance problem. We use an analytical model to evaluate and compare the performance and lifetime of two software-implemented memory-based T-trees and these four hybrid storage structures. The results show that hybrid storage structures can utilize range search abilities, achieve better performance than memory-based T-trees, and improve lifetime from minutes to longer than 60 years. Furthermore, TB+-tree-CAM, a hybrid memristor-based storage structure combining T-tree, B+-tree and CAM, manages to balance between performance and lifetime and can outperform other storage structures when taking both performance and lifetime into consideration.</p> / Dissertation

Ternary content addressable memories (TCAMs) are hardware-based parallel lookup tables with bit-level masking capability. They are attractive for applications such as packet forwarding and classification in network routers. Despite the attractive features of TCAMs, high power consumption is one of the most critical challenges faced by TCAM designers. This work proposes circuit techniques for reducing TCAM power consumption. The main contribution of this work is divided in two parts: (i) reduction in match line (ML) sensing energy, and (ii) static-power reduction techniques. The ML sensing energy is reduced by employing (i) positive-feedback ML sense amplifiers (MLSAs), (ii) low-capacitance comparison logic, and (iii) low-power ML-segmentation techniques. The positive-feedback MLSAs include both resistive and active feedback to reduce the ML sensing energy. A body-bias technique can further improve the feedback action at the expense of additional area and ML capacitance. The measurement results of the active-feedback MLSA show 50-56% reduction in ML sensing energy. The measurement results of the proposed low-capacitance comparison logic show 25% and 42% reductions in ML sensing energy and time, respectively, which can further be improved by careful layout. The low-power ML-segmentation techniques include dual ML TCAM and charge-shared ML. Simulation results of the dual ML TCAM that connects two sides of the comparison logic to two ML segments for sequential sensing show 43% power savings for a small (4%) trade-off in the search speed. The charge-shared ML scheme achieves power savings by partial recycling of the charge stored in the first ML segment. Chip measurement results show that the charge-shared ML scheme results in 11% and 9% reductions in ML sensing time and energy, respectively, which can be improved to 19-25% by using a digitally controlled charge sharing time-window and a slightly modified MLSA. The static power reduction is achieved by a dual-VDD technique and low-leakage TCAM cells. The dual-VDD technique trades-off the excess noise margin of MLSA for smaller cell leakage by applying a smaller VDD to TCAM cells and a larger VDD to the peripheral circuits. The low-leakage TCAM cells trade off the speed of READ and WRITE operations for smaller cell area and leakage. Finally, design and testing of a complete TCAM chip are presented, and compared with other published designs.

Ternary content addressable memories (TCAMs) are hardware-based parallel lookup tables with bit-level masking capability. They are attractive for applications such as packet forwarding and classification in network routers. Despite the attractive features of TCAMs, high power consumption is one of the most critical challenges faced by TCAM designers. This work proposes circuit techniques for reducing TCAM power consumption. The main contribution of this work is divided in two parts: (i) reduction in match line (ML) sensing energy, and (ii) static-power reduction techniques. The ML sensing energy is reduced by employing (i) positive-feedback ML sense amplifiers (MLSAs), (ii) low-capacitance comparison logic, and (iii) low-power ML-segmentation techniques. The positive-feedback MLSAs include both resistive and active feedback to reduce the ML sensing energy. A body-bias technique can further improve the feedback action at the expense of additional area and ML capacitance. The measurement results of the active-feedback MLSA show 50-56% reduction in ML sensing energy. The measurement results of the proposed low-capacitance comparison logic show 25% and 42% reductions in ML sensing energy and time, respectively, which can further be improved by careful layout. The low-power ML-segmentation techniques include dual ML TCAM and charge-shared ML. Simulation results of the dual ML TCAM that connects two sides of the comparison logic to two ML segments for sequential sensing show 43% power savings for a small (4%) trade-off in the search speed. The charge-shared ML scheme achieves power savings by partial recycling of the charge stored in the first ML segment. Chip measurement results show that the charge-shared ML scheme results in 11% and 9% reductions in ML sensing time and energy, respectively, which can be improved to 19-25% by using a digitally controlled charge sharing time-window and a slightly modified MLSA. The static power reduction is achieved by a dual-VDD technique and low-leakage TCAM cells. The dual-VDD technique trades-off the excess noise margin of MLSA for smaller cell leakage by applying a smaller VDD to TCAM cells and a larger VDD to the peripheral circuits. The low-leakage TCAM cells trade off the speed of READ and WRITE operations for smaller cell area and leakage. Finally, design and testing of a complete TCAM chip are presented, and compared with other published designs.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-02-21T21:20:48Z No. of bitstreams: 1 CamilaCristinaRodriguesSalgado_TESE.pdf: 1717909 bytes, checksum: 0abd03e13c72b3217a6cfd68556524b7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-02-22T21:23:23Z (GMT) No. of bitstreams: 1 CamilaCristinaRodriguesSalgado_TESE.pdf: 1717909 bytes, checksum: 0abd03e13c72b3217a6cfd68556524b7 (MD5) / Made available in DSpace on 2018-02-22T21:23:23Z (GMT). No. of bitstreams: 1 CamilaCristinaRodriguesSalgado_TESE.pdf: 1717909 bytes, checksum: 0abd03e13c72b3217a6cfd68556524b7 (MD5) Previous issue date: 2017-12-20 / Uma caracter?stica proeminente da economia de hoje ? a mudan?a r?pida. Contudo, muitas das ideias em estrat?gia v?m de uma ?poca em que as coisas eram mais est?veis, o que tem contribu?do para que o pensamento permane?a enraizado em uma era de in?rcia e estabilidade. Nesse contexto, McGrath (2013b) prop?e uma nova perspectiva que se baseia na ideia da vantagem competitiva transit?ria, ou seja, envolve a ado??o de pr?ticas que se adaptem a ambientes em que as vantagens v?m e v?o, assim como prop?e um novo manual da estrat?gia, que permite que pr?ticas mais male?veis possam emergir. No entanto, apesar do conceito de vantagem competitiva transit?ria ser um marco no novo cen?rio competitivo, trata-se de uma teoria ainda em seus primeiros passos, assim como necessita de uma abordagem pr?tica que facilite sua dissemina??o. Dessa forma, na medida em que ainda n?o existem meios de se analisar essas ideias na pr?tica, tornando-as de fato uma contribui??o ?s organiza??es, o presente estudo teve como objetivo propor um modelo para analisar a conjuntura de empresas no contexto de vantagens competitivas transit?rias. Para isso, foi realizada uma pesquisa explorat?ria, de car?ter aplicado, conduzido de acordo com a abordagem qualitativa. Em termos operacionais, a pesquisa cumpriu as seguintes fases: revis?o te?rica; elabora??o do modelo preliminar - submetido ? avalia??o por meio de pr?teste; elabora??o do modelo final; e aplica??o pr?tica atrav?s de estudo de casos m?ltiplos. Como resultado, foi elaborado e aplicado o Transient Competitive Advantage Model (TCAM), modelo baseado nos elementos Reconfigura??o Cont?nua, Aloca??o de Recursos, Lideran?a, Inova??o e Desligamento, que fundamentam a competi??o no cen?rio de vantagens competitivas transit?rias. J? no que se refere aos casos, tem-se que o TCAM foi aplicado com gestores de seis empresas que t?m a tecnologia como elemento central, e dos oito cen?rios gerados por meio do TCAM foi poss?vel identificar quatro deles: ambiente desfavor?vel; ambiente prop?cio, mas inexplorado; ambiente alerta, mas engessado; e ambiente consistente, mas assistem?tico e reativo. De forma geral, esses resultados refletem realidades ainda distantes da competi??o na era de vantagens transit?rias, apesar do contexto din?mico do qual fazem parte. / A prominent feature of today's economy is the rapid change. However, many of the ideas in strategy come from a time when things were more stable, which has contributed to the fact that the thought remains rooted in an era of inertia and stability. In this context, McGrath (2013b) proposes a new perspective that is based on the idea of transient competitive advantage, that is, it involves the adoption of practices that adapt to environments in which the advantages come and go, as well as proposes a new strategy playbook, which allows more malleable practices to emerge. However, although the concept of transient competitive advantage is a milestone in the new competitive landscape, it is a theory still in its first steps, as well as needs a practical approach that facilitates its dissemination. Thus, to the extent that there are still no means to analyze these ideas in practice, making them a contribution to organizations, the present study aimed to propose a model to analyze the business environment in the context of transient competitive advantages. For this, an exploratory research was carried out, of applied character, conducted according to the qualitative approach. In operational terms, the research accomplished the following phases: theoretical revision; preparation of the preliminary model - submitted to the evaluation by pre-test; elaboration of the final model; and practical application through multiple case studies. As a result, the Transient Competitive Advantage Model (TCAM) was developed and applied based on the elements Continuous Reconfiguration, Resource Allocation, Leadership, Innovation and Disengagement, which underpin the competition in the scenario of transient competitive advantages. Regarding the cases, the TCAM was applied with managers of six companies that have the technology as a central element, and of the eight scenarios generated through the TCAM it was possible to identify four of them: unfavorable environment; environment conducive but unexplored; alert environment, but immobilized; and consistent environment, but non-systematic and reactive environment. In general, these results reflect realities still distant from competition in the era of transient advantages, despite the dynamic context of which they are part.