自一九七七年鄧小平提出科技人才的培養，基礎在教育以來，教育工作被視為促成中國大陸經濟發展的重要議程，也是完成社會主義現代化建設的戰略要點。而教育的發展重在建立合格、穩定的師資陣容，在此一前提下，農村地區為數眾多且學歷不合格的中小學民辦教師，則成為中國大陸提昇人力素質需求下，首要解決的問題。 　　一九七八年以後，中國大陸各地區根據「減少數量，提高質量」的教育方針，逐步擴展民辦教師在職培訓，減少數量並提高其政治、經濟地位。一九九五年二月二十日在廣東惠州召開的全國民辦教師工作會議上，國家教委堅持以「關、招、轉、辭、退」五字方針，解決民辦教師問題，並於公元兩千年之前讓中國大陸民辦教師成為歷史。然而，隨著九年義務教育的推展，教師需求增加；農村地區師資匱乏問題未獲妥善解決；加諸經濟改革以來，部份農村教師棄教從商等現象，均影響目前農村基礎教育的發展。因此，除了片面降低民辦教師數量外，如何運用民辦教師政策，鼓勵兩百多萬農村民辦教師繼續為農村教育奉獻心力，則更具啟發性。 　　本研究之目的乃在： 　　1.探討民辦教師的發展背景； 　　2.分析民辦教師主要的分佈特性； 　　3.瞭解中國大陸現行有關民辦教師的管理體制，以及現行政策之缺失； 　　4.分析中國大陸經濟改革開放後，對民辦教師教學工作與職業流動的影響。 　　另外，除檢討目前政策得失外，研究者也擬定若干建議。 　　依據研究目的，研究者採取文獻分析法與個案研究方法進行民辦教師現況與民辦教師政策問題的分析；另外，本研究也擬以「質的自然研究設計、量的資料蒐集分析、量的統計分析」之統合策略研究法，分析民辦教師區域的分佈特性。 　　研究結果發現，國家財政匱乏、政治因素主導教育發展、農村教師不足以及農村辦學體制的變動，乃是促成民辦教師發展的重要因素。另外，根據統計資料的分析，民辦教師數量與當地社會經濟結構、教育規模有高相關存在。換言之，社會經濟越發達，民辦教師所佔的比重越小，反之，則否。至於農村民辦教師職業流動的現象則呈現區域性的差異，一般而言，社會經濟結構越趨向高度農業化，就業結構越單一化的地區，民辦教師鮮有職業流動，而鄉鎮企業發達、或鄰近都市的農村，民辦教師職業流動現象明顯。 　　此外，在國家教委「關、招、轉、辭、退」的政策推行下，目前中國大陸民辦教師數量與質量獲得明顯的改善。如：民辦教師佔中小學教師總數的比例由一九七八年的59.4%，下降到一九九四年的24.3%；根據個案研究的結果發現，民辦教師學歷普遍提昇到高中以上。不過目前仍存在以下幾個問題： 　　1.片面禁止增聘民辦教師，卻未能解決農村教師不足的情況，導致農村代課教師數量增加，成為變相的民辦教師。 　　2.國家教委人事司與地方政府對「民轉公」政策宗旨認知不同，致使民轉公的選招方式備受爭議。 　　3.民轉公與中師招收在職民辦教師名額少，且考試競爭激烈，教師投入考試準備，怠忽教學工作。 　　4.已取得中專與大專本科學歷的民辦教師，為轉公辦教師仍須到師範學校學習，造成教育資源浪費。 　　5.民辦教師工資、福利與公辦教師相差二倍以上。 　　綜觀上述的問題，研究者建議： 　　1.按民辦教師年齡與學歷，分別考量民轉公選招的標準。 　　2.民轉公名額須與縣（市）地方財政負擔相配合。 　　3.農村教育費附加，由縣統一籌措，並用於保障與提昇民辦教師工資。 　　4.另外，由縣市統一規定農村民辦教師最低保障工資數。 　　5.以互助會的形式建立民辦教師社會福利保險制度。 　　儘管目前以政策性策略降低民辦教師數量的成長，但是長期以來農村地區師資嚴重短缺的問題，始終未獲得根本的解決，導致控制了農村地區民辦教師之數量，卻間接造成代課教師數量的成長。而欲解決農村民辦教師或代課教師的問題，根本之道在研擬一套舒緩農村教師緊缺的新途徑。

Certaines fibres alimentaires réduiraient l'apparition des cancers colorectaux mais l'hypothèse reste contreversée. Un des mécanismes fait intervenir la production par fermentation de butyrate. Nous avons testé deux fibres butyrogènes chimiquement différentes (fructo-oligosaccharides à chaîne courte scFOS, et amidon résistant) versus une fibre faiblement productrice de butyrate (son de blé désamidonné) chez la souris Min, un modèle de carcinogenèse intestinale spontanée. Seul le régime scFOS réduisait le nombre de tumeurs coliques et stimulait l'immunité locale. La nature chimique de la fibre ou bien les propriétés prébiotiques des scFOS (ils favorisent la croissance de bactéries lactiques qui agiraient sur la réaction immunitaire) sont donc impliquées. Deux autres types d'amidons résistants réduisaient le nombre de petites tumeurs. L'addition de bifidobactéries à l'un de ces deux régimes réduisait le nombre de petites tumeurs, mais augmentait celui de grosses tumeurs illustrant le concept de modulation par l'immunogénicité de la dualité immunofacilitation/surveillance. La déplétion en lymphocytes T associée au régime scFOS doublait le nombre de tumeurs par rapport aux souris immunocompétentes. Le régime scFOS diminuait l'expression du récepteur à l'IL2 à la surface des lymphocytes intra-épithéliaux (LIE) suggérant la mise en anergie temporaire du système immunitaire, mais pouvant aussi signifier l'implication d'une autre voie d'activation des LIE. Enfin, pour mettre en place une modélisation des intéractions lympho-épithéliales, nous avons croisé des souris C57BL6 et Min avec la souris transgénique Immortomouse et isolé à partir de primo-cultures de muqueuses des lignées cellulaires conditionnellement immortalisées saines et mutées sur Apc. Ce modèle permettra d'étudier en co-culture sur filtre, l'influence des glucides indigestibles et de leurs produits de fermentation sur les interactions lympho-épithéliales au cours de la carcinogenèse.

<p>Resultaten i undersökningen PISA 2003 visar att finska elever är bättre på problemlösning än svenska elever. Detta arbete undersöker huruvida matematikböcker i de båda länderna skulle kunna vara en bidragande orsak till skillnaderna. Arbetet är begränsat till två böcker från respektive land. För att identifiera de problemlösande uppgifterna har fyra olika kriterier använts. Resultatet av granskningen visar att de finska matematikböckerna har betydligt fler problemlösande uppgifter än de svenska böckerna. Denna skillnad återspeglas både i antal och i hur stor andel av samtliga uppgifter som är problemlösande.</p>

<p>Anna Maria Lenngren (1754-1817) is known as one of <em>Stockholms Posten’s</em> sharpest satirists. Over the years many literature researchers have based their analysis and interpretations on biographical facts. This means that we miss important parts of her authorship, as she almost exceptionally has been writing role-poems. In a role-poem, the author takes a role as a fictitious narrative subject and/or another poem character. This means that the narrator's, or other subject’s opinion does not have to coincide with the real author’s. At the same time, it is important to be open to the possibility that a text in addition to a narrator, may be under the influence of an implied author. This becomes particularly clear in texts that seem to express an opinion that goes against the narrator's own. In this thesis I will show, that in order to understand Lenngren’s poems it is crucial to be aware of various narrative techniques.</p><p>I have tried to bring some of Lenngren’s poems into dialogue with each other, which is rewarding, since many themes, narrative subjects and characters are recurrent. This, combined with the awareness of diverse narrative techniques, makes it possible to see Lenngren’s works in a new light. I have mainly focused on the poems concerning young women, and those involving female writers. My analysis shows that the young girl’s reality seems to be in a cage – a cage that sometimes protects her from losing her innocence, and sometimes causes the opposite.  By drawing parallels between Lenngren's different poems, we can also imagine her way of thinking when it comes to women’s writing.  In some poems the narrative subject defends women's right to write, while other poems describe the reality that female writers in Lenngren's contemporaries had to face.</p>

Resultaten i undersökningen PISA 2003 visar att finska elever är bättre på problemlösning än svenska elever. Detta arbete undersöker huruvida matematikböcker i de båda länderna skulle kunna vara en bidragande orsak till skillnaderna. Arbetet är begränsat till två böcker från respektive land. För att identifiera de problemlösande uppgifterna har fyra olika kriterier använts. Resultatet av granskningen visar att de finska matematikböckerna har betydligt fler problemlösande uppgifter än de svenska böckerna. Denna skillnad återspeglas både i antal och i hur stor andel av samtliga uppgifter som är problemlösande.

Anna Maria Lenngren (1754-1817) is known as one of Stockholms Posten’s sharpest satirists. Over the years many literature researchers have based their analysis and interpretations on biographical facts. This means that we miss important parts of her authorship, as she almost exceptionally has been writing role-poems. In a role-poem, the author takes a role as a fictitious narrative subject and/or another poem character. This means that the narrator's, or other subject’s opinion does not have to coincide with the real author’s. At the same time, it is important to be open to the possibility that a text in addition to a narrator, may be under the influence of an implied author. This becomes particularly clear in texts that seem to express an opinion that goes against the narrator's own. In this thesis I will show, that in order to understand Lenngren’s poems it is crucial to be aware of various narrative techniques. I have tried to bring some of Lenngren’s poems into dialogue with each other, which is rewarding, since many themes, narrative subjects and characters are recurrent. This, combined with the awareness of diverse narrative techniques, makes it possible to see Lenngren’s works in a new light. I have mainly focused on the poems concerning young women, and those involving female writers. My analysis shows that the young girl’s reality seems to be in a cage – a cage that sometimes protects her from losing her innocence, and sometimes causes the opposite.  By drawing parallels between Lenngren's different poems, we can also imagine her way of thinking when it comes to women’s writing.  In some poems the narrative subject defends women's right to write, while other poems describe the reality that female writers in Lenngren's contemporaries had to face.

No description available.

Waterflood optimization via rate control is receiving increased interest because of rapid developments in the smart well completions and I-field technology. The use of inflow control valves (ICV) allows us to optimize the production/injection rates of various segments along the wellbore, thereby maximizing sweep efficiency and delaying water breakthrough. It is well recognized that field scale rate optimization problems are difficult because they often involve highly complex reservoir models, production and facilities related constraints and a large number of unknowns. Some aspects of the optimization problem have been studied before using mainly optimal control theory. However, the applications to-date have been limited to rather small problems because of the computation time and the complexities associated with the formulation and solution of adjoint equations. Field-scale rate optimization for maximizing waterflood sweep efficiency under realistic field conditions has still remained largely unexplored. We propose a practical and efficient approach for computing optimal injection and production rates and thereby manage the waterflood front to maximize sweep efficiency and delay the arrival time to minimize water cycling. Our work relies on equalizing the arrival times of the waterfront at all producers within selected sub-regions of a water flood project. The arrival time optimization has favorable quasi-linear properties and the optimization proceeds smoothly even if our initial conditions are far from the solution. We account for geologic uncertainty using two optimization schemes. The first one is to formulate the objective function in a stochastic form which relies on a combination of expected value and standard deviation combined with a risk attitude coefficient. The second one is to minimize the worst case scenario using a min-max problem formulation. The optimization is performed under operational and facility constraints using a sequential quadratic programming approach. A major advantage of our approach is the analytical computation of the gradient and Hessian of the objective which makes it computationally efficient and suitable for large field cases. Multiple examples are presented to support the robustness and efficiency of the proposed optimization scheme. These include several 2D synthetic examples for validation purposes and 3D field applications.

The code division multiple access (CDMA) system implemented by the direct-sequence (DS) spread spectrum (SS) technique is one of the most promising multiplexing technologies for wireless communications services. The SS communication adopts a technique of using much wider bandwidth necessary to transmit the information over the channel. In the DS-CDMA system, due to the inherent structure interference, referred to as the multiple access interference (MAI), the system performance might degrade. Next, for DS-CDMA systems over frequency-selective fading channels, the effect of inter symbol interference (ISI) will exist, such that a multiuser RAKE receiver has to be employed to combat the ISI as well as MAI. Since, in practical wireless communication environment, there may have several communication systems operated in the same area at the same time. In this thesis, we consider the environment of DS-CDMA systems, where the asynchronous narrow band interference (NBI) due to other systems is joined suddenly to the CDMA system. In general, when a system works in a stable state with adaptive detectors, a suddenly joined NBI signal will cause the system performance to be crash down. Under such circumstance, the existing conventional adaptive RAKE detectors may not be able to track well for the rapidly sudden changing NBI associated with the problems of ISI and MAI. It is known that the adaptive filtering algorithms, based on the sliding window linear constrained recursive least squares (SW LC-RLS), is very attractive to a violent changing environment. The main concern of this thesis is to propose a novel sliding window constant modulus RLS (SW CM-RLS) algorithm, based on the Min/max criterion, to deal with the NBI for DS-CDMA system over multipath channels. For simplicity and having less system complexity the generalized side-lobe canceller (GSC) structure is employed, and is referred to as the SW CM-GSC-RLS algorithm. The aim of the SW CM-GSC-RLS algorithm is used to alleviate the effect of NBI. It has the advantages of having faster convergence property and tracking ability, and can be applied to the environment in which the NBI is suddenly joined to the system under the effect of channel mismatch to achieve desired performance. At the end of this thesis, we extend the idea of the proposed algorithm to the space-time DS-CDMA RAKE receiver, in which the adaptive beamformer with temporal domain DS-CDMA receiver is employed. Via computer simulation results, we show that our new proposed schemes outperform the conventional CM GSC-RLS algorithm as well as the GSC-RLS algorithm (the so-called LCMV approach), in terms of mean square error of estimating channel impulse response, output signal to interference plus noise ratio and bit-error-rate.

Los canales múltiple-entrada-múltiple-salida (MIMO) han sido ampliamente propuestos para superar los desvanecimientos aleatorios de canal en comunicaciones inalámbricas no selectivas en frecuencia. Basados en equipar tanto transmisores como receptores con múltiple antenas, sus ventajas son dobles. Por un lado, permiten al transmisor: i) concentrar la energía transmitida en una dirección-propia determinada, o ii) codificar entre antenas con el fin de superar desvanecimientos no conocidos de canal. Por otro lado, facilitan al receptor el muestreo de la señal en el dominio espacial. Esta operación, seguida por la combinación coherente de muestras, aumenta la relación señal a ruido de entrada al receptor. De esta forma, el procesado multi-antena es capaz de incrementar la capacidad (y la fiabilidad) de la transmisión en escenarios con alta dispersión.Desafortunadamente, no siempre es posible emplazar múltiples antenas en los dispositivos inalámbricos, debido a limitaciones de espacio y/o coste. Para estos casos, la manera más apropiada de explotar el procesado multi-antena es mediante retransmisión, consistente en disponer un conjunto de repetidores inalámbricos que asistan la comunicación entre un grupo de transmisores y un grupo de receptores, todos con una única antena. Con la ayuda de los repetidores, por tanto, los canales MIMO se pueden imitar de manera distribuida. Sin embargo, la capacidad exacta de las comunicaciones con repetidores (así como la manera en que este esquema funciona con respeto al MIMO equivalente) es todavía un problema no resuelto. A dicho problema dedicamos esta tesis.En particular, la presente disertación tiene como objetivo estudiar la capacidad de canales Gaussianos asistidos por múltiples repetidores paralelos. Dos repetidores se dicen paralelos si no existe conexión directa entre ellos, si bien ambos tienen conexión directa con la fuente y el destino de la comunicación. Nos centramos en el análisis de tres canales ampliamente conocidos: el canal punto-a-punto, el canal de múltiple-acceso y el canal de broadcast, y estudiamos su mejora de funcionamiento con repetidores. A lo largo de la tesis, se tomarán las siguientes hipótesis: i) operación full-duplex en los repetidores, ii) conocimiento de canal tanto en transmisión como en recepción, y iii) desvanecimiento sin memoria, e invariante en el tiempo.En primer lugar, analizamos el canal con múltiples repetidores paralelos, en el cual una única fuente se comunica con un único destino en presencia de N repetidores paralelos. Derivamos límites inferiores de la capacidad del canal por medio de las tasas de transmisión conseguibles con distintos protocolos: decodificar-y-enviar, decodificar-parcialmente-y-enviar, comprimir-y-enviar, y repetición lineal. Asimismo, con un fin comparativo, proveemos un límite superior, obtenido a través del Teorema de max-flow-min-cut. Finalmente, para el número de repetidores tendiendo a infinito, presentamos las leyes de crecimiento de todas las tasas de transmisión, así como la del límite superior.A continuación, la tesis se centra en el canal de múltiple-acceso (MAC) con múltiples repetidores paralelos. El canal consiste en múltiples usuarios comunicándose simultáneamente con un único destino en presencia de N repetidores paralelos. Derivamos una cota superior de la región de capacidad de dicho canal utilizando, de nuevo, el Teorema de max-flow-min-cut, y encontramos regiones de tasas de transmisión conseguibles mediante: decodificar-y-enviar, comprimir-y-enviar, y repetición lineal. Asimismo, se analiza el valor asintótico de dichas tasas de transmisión conseguibles, asumiendo el número de usuarios creciendo sin límite. Dicho estudio nos permite intuir el impacto de la diversidad multiusuario en redes de acceso con repetidores.Finalmente, la disertación considera el canal de broadcast (BC) con múltiples repetidores paralelos. En él, una única fuente se comunica con múltiples destinos en presencia de N repetidores paralelos. Para dicho canal, derivamos tasas de transmisión conseguibles dado: i) codificación de canal tipo dirty paper en la fuente, ii) decodificar-y-enviar, comprimir-y-enviar, y repetición lineal, respectivamente, en los repetidores. Además, para repetición lineal, demostramos que la dualidad MAC-BC se cumple. Es decir, la región de tasas de transmisión conseguibles en el BC es igual a aquélla del MAC con una limitación de potencia suma. Utilizando este resultado, se derivan algoritmos de asignación óptima de recursos basados en teoría de optimización convexa. / Multiple-input-multiple-output (MIMO) channels are extensively proposed as a means to overcome the random channel impairments of frequency-flat wireless communications. Based upon placing multiple antennas at both the transmitter and receiver sides of the communication, their virtues are twofold. On the one hand, they allow the transmitter: i) to concentrate the transmitted power onto a desired eigen-direction, or ii) tocode across antennas to overcome unknown channel fading. On the other hand, they permit the receiver to sample the signal on the space domain. This operation, followed by the coherent combination of samples, increases the signal-to-noise ratio at the input of the detector. In fine, MIMO processing is able to provide large capacity (and reliability) gains within rich-scattered scenarios.Nevertheless, equipping wireless handsets with multiple antennas is not always possible or worthwhile. Mainly, due to size and cost constraints, respectively. For these cases, the most appropriate manner to exploit multi-antenna processing is by means of relaying. This consists of a set of wireless relay nodes assisting the communication between a set of single-antenna sources and a set of single-antenna destinations. With the aid of relays, indeed, MIMO channels can be mimicked in a distributed way. However, the exact channel capacity of single-antenna communications with relays (and how this scheme performs with respect to the equivalent MIMO channel) is a long-standing open problem. To it we have devoted this thesis.In particular, the present dissertation aims at studying the capacity of Gaussian channels when assisted by multiple, parallel, relays. Two relays are said to be parallel if there is no direct link between them, while both have direct link from the source and towards the destination. We focus on three well-known channels: the point-to-point channel, the multi-access channel and the broadcast channel, and study their performance improvement with relays. All over the dissertation, the following assumptions are taken: i) full-duplex operation at the relays, ii) transmit and receive channel state information available at all network nodes, and iii) time-invariant, memory-less fading.Firstly, we analyze the multiple-parallel relay channel, where a single source communicates to a single destination in the presence of N parallel relays. The capacity of the channel is lower bounded by means of the achievable rates with different relaying protocols, i.e. decode-and-forward, partial decode-and-forward, compress-and-forward and linear relaying. Likewise, a capacity upper bound is provided for comparison, derived using the max-flow-min-cut Theorem. Finally, for number of relays growing to infinity, the scaling laws of all achievable rates are presented, as well as the one of the upper bound.Next, the dissertation focusses on the multi-access channel (MAC) with multiple-parallel relays. The channel consists of multiple users simultaneously communicating to a single destination in the presence of N parallel relay nodes. We bound the capacity region of the channel using, again, the max-flow-min-cut Theorem and find achievable rate regions by means of decode-and-forward, linear relaying and compress-and-forward. In addition, we analyze the asymptotic performance of the obtained achievable sum-rates, given the number of users growing without bound. Such a study allows us to grasp the impact of multi-user diversity on access networks with relays.Finally, the dissertation considers the broadcast channel (BC) with multiple parallel relays. This consists of a single source communicating to multiple receivers in the presence of N parallel relays. For the channel, we derive achievable rate regions considering: i) dirty paper encoding at the source, and ii) decode-and-forward, linear relaying and compress-and-forward, respectively, at the relays. Moreover, for linear relaying, we prove that MAC-BC duality holds. That is, the achievable rate region of the BC is equal to that of the MAC with a sum-power constraint. Using this result, the computation of the channel's weighted sum-rate with linear relaying is notably simplified. Likewise, convex resource allocation algorithms can be derived.