Thesis (Ph. D.)--Stanford University, 2003. / Includes bibliographical references (leaves 147-161).

L'hydrolyse de l'ATP en ADP constitue la principale source d'énergie de la cellule. Le transport de ce nucléotide depuis son lieu de synthèse vers le cytosol est essentiel pour la plupart des réactions métaboliques et nécessite un passage à travers les membranes. Ainsi, un grand nombre de transporteurs d'ATP/ADP sont présents dans les différents organites tels que les mitochondries, les chloroplastes, et autres types de plastides mais aussi chez les bactéries pathogènes (Rickettsia prowazekii, Protoclamydiae amoebophila) (Trentmann et al, 2007).L'équipe s'intéresse principalement à 2 types de transporteurs d'ADP et d'ATP, la famille des transporteurs mitochondriaux (MCF) et la famille des NTT (plastes et bactéries). Malgré des fonctions similaires, ces 2 familles de transporteurs possèdent des propriétés biochimiques et structurales différentes. De nos jours, il n'existe aucune information structurale disponible sur la famille des NTTs. La détermination de cette structure pourrait permettre de comprendre le mécanisme de transport de ces transporteurs mais plus généralement comprendre le transport de l'ATP et ADP dans les cellules.Une étude a été initiée sur la structure et la fonction de la famille des NTT plus particulièrement des transporteurs chloroplastiques d'Arabidopsis thaliana mais aussi des transporteurs bactériens. Toutefois, ma thèse concerne principalement les transporteurs chloroplastiques NTT1 et NTT2. Ces 2 isoformes sont localisées dans la membrane interne des chloroplastes et permettent de pourvoir le stroma en ATP lorsque la photosynthèse ne peut pas avoir lieu par manque de lumière.Nous avons déterminé et optimisé les conditions de surexpression des 2 isoformes dans un système hétérologue puis de purification en détergent). Nous avons mis au point des méthodes permettant de caractériser le transporteur en solution et de mesurer son activité dans le but d'aboutir à une étude structurale. Des pistes de cristallisation ont également étaient obtenues. / ATP is the main energy currency in the cell and its transport across membranes is essential for most of the metabolic reactions. A large number of ATP/ADP transporters are present in the different cell organelles such as mitochondria, chloroplasts, other types of plastids and some are also found in bacteria (Rickettsia prowazekii, Protoclamydiae amoebophila) (Trentmann et al, 2007). The team is mainly interested in two distinct transporters families, the mitochondrial carrier family (MCF) and the NTT family. Despite similar function, mitochondrial ADP/ATP transporters (Pebay-Peyroula et al, 2003) and NTT proteins exhibit different structural and biochemical properties. To date no structural information is available on the NTT family. The determination of a structure would help for understanding the transport mechanism of these carriers and more generally the different mechanisms of the transport of ADP and ATP within the cell.We initiated a structure-function study on the NTT family focusing on chloroplast transporters from Arabidopsis thaliana and also from bacteria. My thesis is focused on chloroplast NTT1 and NTT2. These isoforms are localized in the inner membrane of chloroplast. They transport ATP inside the chloroplast in order to supply the different reactions occurring in the stroma when the photosynthesis does not occur.We have determined and optimized conditions to overexpress these 2 isoforms in heterologous systems and to purify the protein in detergents. We have also set up tools to characterize the carrier in solution and to measure its transport activity opening the way to functional and structural studies. We obtained promising crystallization hits.

Une des caractéristiques définissant les êtres vivants est leur capacité à se reproduire. La reproduction sexuée est le mécanisme qui a encouragé la sélection positive des espèces au cours de l’évolution en augmentant leurs diversités génétiques. Lors de leurs reproductions les angiospermes (les plantes à fleurs) utilisent un organe sexuel appelé fleur. Le sexe de cet organe est déterminé par la présence ou l’absence de deux différents types de tissus reproducteurs. Le tissu reproducteur mâle est appelé étamine et porte le pollen. Le tissu reproducteur femelle est appelé pistil et est constitué d’un ou plusieurs carpelles. La labilité sexuelle et l’importance économique des Cucurbites comme Cucumis melo (le melon), Cucumis sativus (le concombre) et Citrullus lanatus (la pastèque) ont fait d’eux des organismes-modèles pour l’étude du déterminisme du sexe contrôlé par un réseau génétique. Le modèle génétique du déterminisme du sexe de Cucumis melo peut être expliqué par la modulation et l’interaction de trois gènes: CmACS-7, CmWIP1, CmACS11. Le gène CmACS-7 est situé au locus M et code une enzyme de biosynthèse de l’éthylène (Boualem et al 2008) réprimant le développement des étamines. Le gène CmWIP1 est situé au locus G et code un facteur de transcription potentiel réprimant le développement du carpelle (Martin and al 2010). Et le gène CmACS11 est situé au locus A et code une enzyme de biosynthèse de l’éthylène réprimant l’expression de CmWIP1 (Boualem et al 2015). Au vu de la croissance de la population mondiale, il est nécessaire d’élargir le nombre d’outils génétiques permettant l’amélioration de la sélection variétale des plantes cultivées dont font partie les Cucurbites. La plupart des plantes hybrides sont issues d’un croisement entre deux plantes différentes, une plante mâle et une plante femelle. Pour améliorer la production de ces hybrides, il est primordial de connaître le sexe des plantes parentes et particulièrement celui des lignées femelles. Dans cette optique, les sélectionneurs ont besoin d’élargir leurs panels d’allèles permettant le contrôle du développement du carpelle. L’ingénierie de ces allèles permettra de générer des plantes gynoïques portant uniquement des fleurs femelles mais aussi d’augmenter la proportion de fleurs pistillées et de contrôler le délai d’apparition des fleurs pistillées. Ces améliorations de la sélection variétale des Cucurbites pourraient générer des alternatives aux mécanismes de stérilité mâle, de castration manuelle ou chimique. Ainsi qu’une meilleure maîtrise de l’apparition de l’effet nid, générant des plantes potentiellement plus compactes et plus rapidement productives. La manipulation des mécanismes, régulés par CmWIP1 et contrôlant le développement du pistil, pourrait permettre d’identifier de nouveaux allèles impliqués dans le développement du carpelle. Mes travaux de recherche se sont appuyés sur la mise en œuvre d’un crible génétique afin d’identifier les membres du réseau génétique auquel appartient CmWIP1, l’unique gène identifié à ce jour contrôlant le développement du carpelle chez C. melo. Ma thèse a eu pour but d’identifier des gènes suppresseurs de la fonction de TT1 (AtWIP1) et de NTT (AtWIP2), deux membres de la famille WIP chez Arabidopsis thaliana. Ces mutations suppresseurs pourront supprimer les phénotypes d’arrêt de croissance et de sénescence induits par la surexpression de TT1 ou de NTT. Pour cela, j’ai généré une population de lignées d’Arabidopsis thaliana surexprimant de manière inductible les séquences codantes de TT1 ou NTT et ayant subi une mutagenèse à l’EMS. J’ai ensuite criblé cette population pour identifier les plantes suppresseurs et les mutations causales. Mon projet de recherche a permis d’identifier quatre locus potentiellement impliqués dans le contrôle du développement du carpelle. La caractérisation de ces locus pourra aboutir à un meilleur contrôle du déterminisme du sexe des Cucurbites et des plantes possédant un mécanisme similaire. / One of the characteristics of living organisms is the ability to reproduce themselves. Sexual reproduction is a mechanism that increases the potential diversity of species and their positive selection. To reproduce most of plants species use a type of sexual organ named flower. The sex of this organ is determined by the presence or absence of two different types of reproductive tissue. The stamen is the male reproductive tissue and the carpel is (the female reproductive tissue). In many species the development of these tissues is controlled by a network of genes. Cucumis melo (melon) is a model plant to study genetic network controlling sex determination. Melon sex determination genetic model can be explained by the modulation of three genes. The gene CmACS-7 at the locus M which encodes for an ethylene biosynthesis enzyme that represses stamen development (Boualem and al 2008). The gene CmWIP1 at the locus G which encodes a putative transcription factor that represses carpel development (Martin and al 2010). And the gene CmACS11 at the locus A which encode for an ethylene biosynthesis enzyme that represses CmWIP1 expression (boualem et al 2015). The aim of this thesis project is to understand in which biological process cmWIP1 is involved to inhibit carpel development. The identification of the precise function of cmWIP1 will lead to the identification of new putative alleles controlling carpel development and sex determination. To achieve this goal we set up a genetic screen in Arabidopsis thaliana to unravel genetic interactors of CmWIP1. At the present moment we found four putative genetic interactors. These putative candidates will be tested in melon. Plants that are mutated in theses cmWIP1 genetic interactors should harbour female organ inside each of their flowers. Then the introgression of these alleles in crop species may increase fruit and/or seed yields.

abstract: Lattice-based Cryptography is an up and coming field of cryptography that utilizes the difficulty of lattice problems to design lattice-based cryptosystems that are resistant to quantum attacks and applicable to Fully Homomorphic Encryption schemes (FHE). In this thesis, the parallelization of the Residue Number System (RNS) and algorithmic efficiency of the Number Theoretic Transform (NTT) are combined to tackle the most significant bottleneck of polynomial ring multiplication with the hardware design of an optimized RNS-based NTT polynomial multiplier. The design utilizes Negative Wrapped Convolution, the NTT, RNS Montgomery reduction with Bajard and Shenoy extensions, and optimized modular 32-bit channel arithmetic for nine RNS channels to accomplish an RNS polynomial multiplication. In addition to a full software implementation of the whole system, a pipelined and optimized RNS-based NTT unit with 4 RNS butterflies is implemented on the Xilinx Artix-7 FPGA(xc7a200tlffg1156-2L) for size and delay estimates. The hardware implementation achieves an operating frequency of 47.043 MHz and utilizes 13239 LUT's, 4010 FF's, and 330 DSP blocks, allowing for multiple simultaneously operating NTT units depending on FGPA size constraints. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020

This item contains the agenda, minutes, and attachments for the Faculty Senate meeting on this date. There may be additional materials from the meeting available at the Faculty Center.

Efficient implementation of the number theoretic transform(NTT), also known as the discrete Fourier transform(DFT) over a finite field, has been studied actively for decades and found many applications in digital signal processing. In 1971 Schonhage and Strassen proposed an NTT based asymptotically fast multiplication method with the asymptotic complexity O(m log m log log m) for multiplication of $m$-bit integers or (m-1)st degree polynomials. Schonhage and Strassen's algorithm was known to be the asymptotically fastest multiplication algorithm until Furer improved upon it in 2007. However, unfortunately, both algorithms bear significant overhead due to the conversions between the time and frequency domains which makes them impractical for small operands, e.g. less than 1000 bits in length as used in many applications. With this work we investigate for the first time the practical application of the NTT, which found applications in digital signal processing, to finite field multiplication with an emphasis on elliptic curve cryptography(ECC). We present efficient parameters for practical application of NTT based finite field multiplication to ECC which requires key and operand sizes as short as 160 bits in length. With this work, for the first time, the use of NTT based finite field arithmetic is proposed for ECC and shown to be efficient. We introduce an efficient algorithm, named DFT modular multiplication, for computing Montgomery products of polynomials in the frequency domain which facilitates efficient multiplication in GF(p^m). Our algorithm performs the entire modular multiplication, including modular reduction, in the frequency domain, and thus eliminates costly back and forth conversions between the frequency and time domains. We show that, especially in computationally constrained platforms, multiplication of finite field elements may be achieved more efficiently in the frequency domain than in the time domain for operand sizes relevant to ECC. This work presents the first hardware implementation of a frequency domain multiplier suitable for ECC and the first hardware implementation of ECC in the frequency domain. We introduce a novel area/time efficient ECC processor architecture which performs all finite field arithmetic operations in the frequency domain utilizing DFT modular multiplication over a class of Optimal Extension Fields(OEF). The proposed architecture achieves extension field modular multiplication in the frequency domain with only a linear number of base field GF(p) multiplications in addition to a quadratic number of simpler operations such as addition and bitwise rotation. With its low area and high speed, the proposed architecture is well suited for ECC in small device environments such as smart cards and wireless sensor networks nodes. Finally, we propose an adaptation of the Itoh-Tsujii algorithm to the frequency domain which can achieve efficient inversion in a class of OEFs relevant to ECC. This is the first time a frequency domain finite field inversion algorithm is proposed for ECC and we believe our algorithm will be well suited for efficient constrained hardware implementations of ECC in affine coordinates.

在現今之行動通訊產業中，面對技術融合、顧客需求多樣化、快速創新的衝即，整個產業結構已發生了根本上的影響。傳統行動通訊產業中的線性價值鏈已不復見，而是重新聚合成全新的價值網，而這個新的價值網跨越了原本各自獨立的產業界線，並經由不同的連結方式，形成新的產業形態，展現出新的面貌。其中，更可以明顯發現，透過許多不同領域能力之結合，可以造就出許多新事業、新市場的誕生。據此，企業為了追求快速創新，便不可能僅憑一己之力，於內部發展出各式各樣之能力。反之，企業必須由外部擷取他人之力，再與內部核心能力結合，與外部關係人建立共生關係，最終達成多贏之局面。據此，Chesbrough (2003) 認為，企業過去「封閉式創新」的作法已不合時宜，未來必須走向「開放式創新」。 本研究在文獻探討的部分，將焦點放在三大議題：開放式創新、經營模式與平台型經營模式。同時，選擇全球行動通訊產業的領導廠商 – NTT DoCoMo為個案公司，從1999年至2007年之公司資料中，歸納出個案公司的三大議題：發展歷程、經營模式與合作關係。 最後，本研究歸納出以下結論：第一：平台型經營模式有利於企業有效且及時地連結外部環境之資源，以實踐開放式創新；第二：企業在追求快速創新之目標時，其所採用之創新模式可依據下述兩種要素來區分：合作關係之廣度與資源投入之程度。而面對不同核心程度之能力時，須採用不同之模式；第三：平台型經營模式由眾多構面組成，而面對不同的構面，企業須採用不同的模式來發展；第四：成功的平台型經營模式必須具備吸引力與主導力。 / Today, the mobile communication industry is faced with the impact of technology fusion, diversified customers’ demand and fast innovation; this industry already changed fundamentally. The linear value chain of traditional mobile communication industry is no more, instead, there is a whole new value net, which is connected in different way to become a new industry. From the result, through the combination of capabilities from different areas, it can lead to many new businesses and markets. According to the above, for the purpose of fast innovation, companies are impossible to develop various capabilities all by themselves inside; instead, companies have to introduce other capabilities from outside and combine with their core capabilities. Through the establishment of ecosystem, it will lead to the all-win situation. According to the above, Chesbrough argues that the traditional close innovation is no more, it is the age of open innovation. In this research, the literature review focuses on three issues: open innovation, business model and platform business model. Meanwhile, this research chooses the global leading company in mobile communication industry – NTT DoCoMo as the case company and the case study focuses on three issues: history, business model and collaborative relationships. This research reaches three conclusions. First, platform business model can help companies connect with the environment effectively and timely. Second, open innovation includes two different concepts: open and closed at the same time and these different concepts should be applied to different capabilities. Third, business model is composed of many aspects, and different aspects should be developed by different concepts. Forth, open business model’s paradigm is platform business model and two of platform business model’s fundamental forces are attraction and predomination.

今日許多受限於資源、市場限制的企業，以多邊經營模式突破重圍，展現出亮麗績效。多邊事業早在過去就已存在，然而相關理論與研究為近五年來的事情，台灣企業受限於市場、資源限制，如何藉由多邊思維，從而再創企業高峰，為本研究初始動機。隨著資訊科技發展，過去策略談論企業如何開創市場、滿足顧客，從而成為市場領導者。其多半以一維角度探討，公司如何藉由研究與發展極大化商品價值，進而提供超乎顧客期待。而多邊思維的出現，將傳統一維思考拉升至二維，公司縱使無能力滿足顧客需求，亦能夠尋求多方合作，促成顧客與其他企業交易，從中扮演媒合角色。本論文主要貢獻在於，將主要相關多邊文獻及經營模式架構結合，並以NTT DoCoMo進行實證討論，從而提出多邊企業經營模式建構。 為了導出多邊企業經營模式建構，本研究首先瞭解今日多邊事業與觸媒策略發展，從而與過去學者所提出經營模式架構與要素，得出多邊企業經營模式設計指引流程。而後以NTT DoCoMo其在2000年前後成功打造i-mode多邊平台擴張實例，作為驗證與支撐多邊企業經營模式設計指引方針。易言之，以多邊企業、經營模式與NTT DoCoMo i-mode作法，進行三方交流探討。從中歸納推演出多邊企業經營模式建構。 研究結果發現，第一：多邊平台打破過去價值網路與顧客介面間接關係，其將兩邊直接連結，使得多邊平台能夠與外界環境保持動態平衡。第二：核心策略與策略性資源，將決定平台擴張方向與深度，兩者相輔相成良性循環下，能夠促成多邊事業的擴張與成長。第三：相較於單邊企業，價值網絡和關係動態，為多邊企業營運成功與否重要關鍵。 / Abstract Nowadays, many companies are limited in resources which compels them to make market break throughs via multi-sided business models to improve performance. Multi-sided business models existed in the past, but relevant theories and research have only been around for five years. Taiwanese companies are constrained by lack of resources and market size. Therefore, exploring how to use multi-sided business models to create break throughs is the main motive of this research. With the development of information technology, past strategy issues focused on how to explore new markets, satisfied customers, or become the market leader. Their goal is to maximize the value of goods in a linear value chain. The emergence of a multi-sided perspective adds value to the increased networking of the linear value chain. Hence, companies without the ability to satisfy customers may seek co-operative strategies to reach customers through other business transactions. The main contribution of this paper combines the major relevant multi-sided literature and architecture of business models as well as an empirical discussion of NTT DoCoMo. First, this study will attempt understand the development of multi-sided business and business models from research. Based on such an understanding, this research will delve into the multi-sided business model process as well as design guidelines. Second, this research will use the example of NTT DoCoMo’s i-mode case as validation and support for the business model design guidelines of the multi-sided approach. In other words, for a multi-sided business, business model and the NTT DoCoMo i-mode case explores a three-way approach which deduces the multi-sided business model construction. This research reaches three conclusions. First, multi-sided platforms break the indirect relationship between value networks and customer interface. Further, there is a direct link to both sides which makes the multi-sided platform maintain a dynamic equilibrium with the external environment. Second, core strategy and strategic resources determine the direction of expansion and depth of platform. These two components can contribute to the expansion of multi-sided business growth. Third, in contrast to unilateral business, value network and relationship dynamics are the key of multi-sided business success.

行動電視是發展行動商務的重要基礎，近年來由於傳輸技術的進展使得行動電視服務的提供成為可能，透過數位電視廣播技術與行動通訊網路的整合包裝，業者可提供更豐富的行動商務內容。行動通訊業者、廣播電視業者，及手機業者由於亟欲開發下一波的主流商品和服務，紛紛投入行動電視的相關發展。不過，行動電視屬於全新且跨領域的商業模式，還有許多問題有待克服。本研究企圖將這些問題釐清，除了探討行動電視價值鏈上各價值活動的發展方向以及整合模式，亦進一步探討行動電視服務的關鍵成功因素，以及南韓SK Telecom與日本NTT DoCoMo發展行動電視服務的策略。針對上述研究問題，本研究之研究結論如下： 1. 行動電視價值鏈的發展：內容業者必須針對手機平台開發專屬的節目內容；數位電視廣播技術以及行動通訊網路將朝向互補整合的方向，才能為消費者創造更多價值；手機製造業者必須克服天線、耗電量，以及體積的問題，並且設計容易使用的操作介面。 2. 整合模式：分為由行動通訊業者主導、由廣播電視業者主導、由行動通訊業者與廣播電視業者共同合作，以及由第三方業者提供服務這四種主要的營運模式。其中，行動通訊業者與廣播電視業者共同合作被視為較可能普及的營運模式。 3. 關鍵成功因素：透過產業資料分析以及專家訪談，本研究整理出以下六點要素，分別為政府的態度、良好的網路傳輸品質、終端設備的設計、各方可接受的營運模式、具吸引力的內容，以及可負擔的價格。 4. 個案探討：南韓SK Telecom與日本NTT DoCoMo皆非常注重內容的發展，除了重新設計節目內容、持續發展新內容，亦不斷累積相關的數位內容資源，由其策略發展重點，也可以再次印證關鍵成功因素—「內容」的重要性。 / Mobile TV is considered as the basis of mobile commerce. Through the integration of digital broadcasting and cellular network, companies can provide more mobile service. Due to the development of digital broadcasting and cellular network, offering service of mobile TV becomes possible. Mobile operators, broadcasters, and mobile phone manufactures are all eager to develop new products and service. Therefore, they start to develop mobile TV business. However, mobile TV is a brand new business model and relates to different industries. There are still lots of difficulties that need to be conquered. This research analyzes the development of mobile TV value chain, possible business models, key success factors, and the cases of SK Telecom and NTT DoCoMo. The following is the conclusion of this research. 1. Development of Mobile TV value chain: content providers have to develop exclusive programs for mobile phone; digital broadcasting and cellular network should be integrated; mobile phone manufactures need to conquer the problems of battery, aerial, and size. 2. Business model: there are four possible business models, inclusive of leading by mobile operators, leading by content providers, cooperation of mobile operators and content providers, and service offered by the third party. The third business model is considered as the one which will be popular. 3. Key success factors: there are six factors, inclusive of government’s attitude, good transmitting quality, design of hand-held device, business model accepted by all involved parties, attractive content, and acceptable price. 4. Case discussion: SK Telecom and NTT DoCoMo all think highly of the development of content. They plan to develop exclusive programs, enrich the content, and accumulate related digital contents. Their strategies reveal the importance of content again.

Made available in DSpace on 2010-04-20T20:20:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-06-27T00:00:00Z / Trata do tema de avaliação de empresas utilizando o método do fluxo de caixa descontado, conduzido por meio de um estudo de caso, cujo objeto é a empresa japonesa NTT DoCoMo, operadora de telecomunicações. Aborda considerações estratégicas da companhia e do setor de telecomunicações, em particular dos direcionadores de valor. Analisa as principais causas determinantes do valor de mercado da empresa NTT DoCoMo, relacionando-as com a prestação de novos serviços de telefonia celular