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This dissertation work considers communication between people. I look at coordinating dyads (couples in relationships) and people in working relationships to develop an understanding of how people engage in high-stakes, or emotional communication via various communicative media. The approach for this research is to observe and measure people's behavior during interaction and subsequent reporting of that behavior and associated internal experiences. Qualitative and quantitative methods are employed. Quantitative data are analyzed using a range of statistical analyses, including correlations matrices, ANOVAs, and multivariate statistics. Two controlled laboratory experiments were conducted for this research. These experiments involved couples in relationships. Couples were brought into the lab and argued with each other across one of three technological media: face-to-face, telephone, and instant messaging (IM). In one set of couples' experiments, the couples argued for twenty minutes; in the subsequent couples' experiment, couples were encouraged to take as much time as they needed for their arguments. One of the main results from the first experiment is that couples did, indeed, argue when brought into a laboratory setting. One of the important findings for the second experiment is that time did not affect couples' tendency to reach closure during their arguments. This research is a contribution in that it examines how people engage in highly emotional communication using various technological media. In a society with ever-increasing communication needs that require technology, it becomes necessary to study its communicative affordances. Understanding the context of highly emotional interactions between members of couples gives insight into how technology meets (or fails to meet) these communication needs. / Ph. D.

本研究以台大批踢踢實業坊（PTT）政治類看板為例，企圖評估電子布告欄（BBS）系統是否為承載政治意見的理想論域。 在文獻探討的過程中可知，「政治參與」對於民主發展至為重要，而其中透過網際網路進行的政治意見表達，在數位時代來臨後的重要性與日俱增。因此本研究以哈伯瑪斯的公共領域與溝通行動理論為核心，建立「理想意見論域」的三項標準：開放性、公共性、理性。並據此三項標準，對研究場域PTT政治類看板進行評估。 本研究以量化的內容分析法為主，輔以直接觀察，對研究場域及其中政治意見的性質，進行客觀的描述與分析。研究結果發現，PTT政治類看板進入和參與的門檻低、互動熱絡頻繁、討論規範也並未限制理性發言空間，在「開放性」上表現佳；至於「公共性」的部分，在討論規範與看板管理者的約束下，討論的議題多能與公共事務相關；然而在「理性」面向上，論證嚴謹程度普遍不足，亦僅有半數的發言能完全保持冷靜平和。 另外，在把政治意見的各項性質進行交叉分析後，可歸納出「理想網路論域」中的「理想政治意見」，應該具有的條件包括：沒有明顯的政黨傾向、篇幅充實、切合討論主題、以事實陳述輔助個人意見、不純粹批評而是褒貶參半或持平而論、情緒冷靜平和、論證深入而嚴謹等。

La Résonance Magnétique Nucléaire RMN DOSY (Diffusion Ordered SpectroscopY) 1H est une technique permettant de mesurer les coefficients de diffusion des espèces en solution. Elle permet ainsi d’obtenir des informations structurales de par sa dimension RMN conventionnelle mais également des informations physico-chimiques telles que la taille de la (macro)molécule ou encore la formation d’agrégats. L’objectif de ces travaux a été d’examiner comment les méthodes de RMN (RMN 1D ,2D et DOSY), permettent de fournir des informations sur la caractérisation des matériaux polymères. La première partie de ce travail souligne l’intérêt de la RMN pour la caractérisation de la microstructure de quelques matériaux polymères en s’attardant plus particulièrement sur l’exploration de leurs extrémités de chaînes. La RMN s’est en effet révélée très performante pour établir le lien entre extrémité de chaîne et méthode de polymérisation appliquée. Le deuxième volet de ces travaux concerne l’étude de quelques architectures complexes (type dibloc et tribloc) et la mise en évidence du caractère contrôlé d’une copolymérisation radicalaire grâce à la RMN diffusionnelle. Nous avons également vu comment déterminer la masse moyenne en poids (Mw) par une simple mesure du coefficient d’autodiffusion. Finalement, l’ensemble des travaux présentés dans ce manuscrit a été valorisé grâce à l’étude des interactions par RMN diffusionnelle. Plus particulièrement la RMN DOSY 1H a permis d’observer des phénomènes de micellisation, d’agrégation, d’encapsulation et de relargage de molécules de principe actif. / Diffusion Ordered Spectroscopic Nuclear Magnetic Resonance (DOSY NMR 1H) makes it possible to determine physicochemical data such diffusion coefficients. While typical NMR data on the structure of molecules can be obtained, this technique also permits determinations of the physicochemical characteristics, such as molecular sizes or aggregate formation. The objective of this work was to examine how various NMR methodologies, specifically, 1 and 2 dimensional DOSY NMR, can be applied to the characterization of polymers. The first part of the manuscript relates the NMR characterization of some polymeric materials with a special interest in chain-end groups. In particular, we demonstrate the relationships between chain-ends and the polymerization methods employed. In a second part, the potential of the DOSY technique is used to determine controlled features of a radical polymerization resulting in di- and triblock architectures. Molecular weights are also determined by self-diffusion coefficient measurements. The results presented herein demonstrate that diffusional NMR can be effectively employed to understand interactions in polymeric structures. Indeed, DOSY 1H-NMR provides new interesting results concerning micellization, aggregation, encapsulation phenomena and the release of active molecules.

In this thesis, we consider optimal control problems arising in high-speed integrated communication networks with Quality of Service (QOS) constraints. Integrated networks are expected to carry a large variety of traffic sources with widely varying traffic characteristics and performance requirements. Broadly, the traffic sources fall into two categories: (a) real-time sources with specified performance criteria, like small end to end delay and loss probability (sources of this type are referred to as Type 1 sources below), and (b) sources that do not have stringent performance criteria and do not demand performance guarantees from the network - the so-called Best Effort Type sources (these are referred to as Type 2 sources below). From the network's point of view, Type 2 sources are much more "controllable" than Type 1 sources, in the sense that the Type 2 sources can be dynamically slowed down, stopped or speeded up depending on traffic congestion in the network, while for Type 1 sources, the only control action available in case of congestion is packet dropping. Carrying sources of both types in the same network concurrently while meeting the performance objectives of Type 1 sources is a challenge and raises the question of equitable sharing of resources. The objective is to carry as much Type 2 traffic as possible without sacrificing the performance requirements of Type 1 traffic. We consider simple models that capture this situation. Consider a network node through which two connections pass, one each of Types 1 and 2. One would like to maximize the throughput of the Type 2 connection while ensuring that the Type 1 connection's performance objectives are met. This can be set up as a constrained optimization problem that, however, is very hard to solve. We introduce a parameter b that represents the "cost" of buffer occupancy by Type 2 traffic. Since buffer space is limited and shared, a queued Type 2 packet means that a buffer position is not available for storing a Type 1 packet; to discourage the Type 2 connection from hogging the buffer, the cost parameter b is introduced, while a reward for each Type 2 packet coming into the buffer encourages the Type 2 connection to transmit at a high rate. Using standard on-off models for the Type 1 sources, we show how values can be assigned to the parameter b; the value depends on the characteristics of the Type 1 connection passing through the node, i.e., whether it is a Variable Bit Rate (VBR) video connection or a Continuous Bit Rate (CBR) connection etc. Our approach gives concrete networking significance to the parameter b, which has long been considered as an abstract parameter in reward-penalty formulations of flow control problems (for example, [Stidham '85]). Having seen how to assign values to b, we focus on the Type 2 connection next. Since Type 2 connections do not have strict performance requirements, it is possible to defer transmitting a Type 2 packet, if the conditions downstream so warrant. This leads to the question: what is the "best" transmission policy for Type 2 packets? Decisions to transmit or not must be based on congestion conditions downstream; however, the network state that is available at any instant gives information that is old, since feedback latency is an inherent feature of high speed networks. Thus the problem is to identify the best transmission policy under delayed feedback information. We study this problem in the framework of Markov Decision Theory. With appropriate assumptions on the arrivals, service times and scheduling discipline at a network node, we formulate our problem as a Partially Observable Controlled Markov Chain (PO-CMC). We then give an equivalent formulation of the problem in terms of a Completely Observable Controlled Markov Chain (CO-CMC) that is easier to deal with., Using Dynamic Programming and Value Iteration, we identify structural properties of an optimal transmission policy when the delay in obtaining feedback information is one time slot. For both discounted and average cost criteria, we show that the optimal policy has a two-threshold structure, with the threshold on the observed queue length depending, on whether a Type 2 packet was transmitted in the last slot or not. For an observation delay k > 2, the Value Iteration technique does not yield results. We use the structure of the problem to provide computable upper and lower bounds to the optimal value function. A study of these bounds yields information about the structure of the optimal policy for this problem. We show that for appropriate values of the parameters of the problem, depending on the number of transmissions in the last k steps, there is an "upper cut off" number which is a value such that if the observed queue length is greater than or equal to this number, the optimal action is to not transmit. Since the number of transmissions in the last k steps is between 0 and A: both inclusive, we have a stack of (k+1) upper cut off values. We conjecture that these (k + l) values axe thresholds and the optimal policy for this problem has a (k + l)-threshold structure. So far it has been assumed that the parameters of the problem are known at the transmission control point. In reality, this is usually not known and changes over time. Thus, one needs an adaptive transmission policy that keeps track of and adjusts to changing network conditions. We show that the information structure in our problem admits a simple adaptive policy that performs reasonably well in a quasi-static traffic environment. Up to this point, the models we have studied correspond to a single hop in a virtual connection. We consider the multiple hop problem next. A basic matter of interest here is whether one should have end to end or hop by hop controls. We develop a sample path approach to answer this question. It turns out that depending on the relative values of the b parameter in the transmitting node and its downstream neighbour, sometimes end to end controls are preferable while at other times hop by hop controls are preferable. Finally, we consider a routing problem in a high speed network where feedback information is delayed, as usual. As before, we formulate the problem in the framework of Markov Decision Theory and apply Value Iteration to deduce structural properties of an optimal control policy. We show that for both discounted and average cost criteria, the optimal policy for an observation delay of one slot is Join the Shortest Expected Queue (JSEQ) - a natural and intuitively satisfactory extension of the well-known Join the Shortest Queue (JSQ) policy that is optimal when there is no feedback delay (see, for example, [Weber 78]). However, for an observation delay of more than one slot, we show that the JSEQ policy is not optimal. Determining the structure of the optimal policy for a delay k>2 appears to be very difficult using the Value Iteration approach; we explore some likely policies by simulation.

Abstract  The present work is a quantitative and qualitative analysis of pragmatic strategies for delivering critique, and types of politeness, used by undergraduate L2 students of English at different stages of peer-review discussion. The material examined consists of four corpora of authentic conversations between students, the main purpose of which was to give feedback on each other’s contributions during an English A-level course, at Mid-Sweden University. The conversations explored were carried out electronically, and represent four different online environments, or modes of computer-mediated communication (CMC). The material from the two asynchronous modes of CMC is comprised of L2 students’ written discussion board messages and spoken posts recorded using online software. The two synchronous environments under investigation are text-based and voice-based chat. Taking Brown and Levinson’s (1987) framework of politeness as a point of departure, the present study uses a combination of corpus and conversation analytical methods. The basic unit of analysis has been defined as the shortest message of peer-review critique that constitutes a thematic unit: these have been examined in terms of their content and politeness features associated with them, and analyzed in terms of the pragmatic strategy and type of politeness adopted. The types of pragmatic strategies or message organization patterns at different stages, i.e. initial versus subsequent feedback, of the peer-review discussion have also been analyzed. The results of the study show that the pragmatic strategies aimed at praise and agreement prevail in the corpus data produced by predominantly native speakers of Swedish. Even though the pragmatic strategies used for disagreement and negative evaluation are rich in propositional content, their occurrences and distribution vary across the four modes of CMC examined. These results seem to have wider implications in the context of online L2 learning activities, providing insights about the language of peer-review critique in a Swedish academic setting.   Keywords: computer-mediated communication (CMC), Conversation Analysis (CA), conversation management, discussion boards, feedback category, mode of CMC, peer-review discussion, politeness theory, pragmatic strategy, speech act of critique, text-based chat, type of politeness, voice-based chat, VoiceThread