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Anisotropy in the spatial arrangement of species and also geometric anisotropy in the components of liquid and soft matter systems gives rise to complex phase and non-trivial dynamic behaviors. Many systems are encompassed by this description including polymers, guest molecules in porous gels or nano-structured materials and also orientable fluids. In order to understand these systems, computational studies provide valuable insight. The study of such systems computationally is difficult if not prohibitive thus it is necessary to reduce these systems to simple models that capture the essential physical processes that govern the dynamics and phase behavior. Two simple models fit into this category: systems where the surrounding solvent is held stationary, a Lorentz model and also systems where a liquid crystal is formed from hard spherocylinders and is driven by an electric field. The Lorentz models studied provide a description of the dynamical regimes accessible when the probe and/or scatterers are given geometric anisotropy. The resulting dynamics are studied when order is present in the stationary solvent, i.e. structured versus isotropic solvent structure. Effective channels depending upon the competition of length scales as well as the structure of the stationary solvent leads to transitions in the dynamics of the traversing probe. Geometric anisotropy in nematogens in liquid crystals leads to the formation of mesophases indicative of a liquid crystal. When coupled to a rotating electric field, the dynamics and phase of the nematogens can be controlled.

The traffic network is subject to random disruptions, such as incidents, bad weather, or other drivers’ random behavior. A traveler’s route choice behavior in such a network is thus affected by the probabilities of such disruptions, his/her attitude towards risk, and real-time information on revealed traffic conditions that could potentially reduce the level of uncertainty due to the disruptions. As the road network’s performance is de-termined collectively by all travelers’ choices, it is also affected by these factors. This thesis features the development of a multi-class user equilibrium model based on hetero-geneous risk attitude distributions and a user equilibrium model based on various disrup-tion probabilities and information penetration rates that can be used to perform sensitivity analyses for a traffic network. The method of successive average (MSA) is used to solve for the equilibrium conditions. Laboratory experimental data are used to calibrate the risk attitude model. A sample sensitivity analysis is performed to show the disruption and in-formation penetration effects on network performance. Initial calibrations show promis-ing results for route flow predictions in a congested network with respect to heterogene-ous attitude. With respect to disruption probability and information access, having too v high information penetration will not improve the network’s performance, while having a small disruption probability can improve traffic conditions in the network

本研究分析消費者如何在不同的社群網路間作出選擇，當用戶使用社群網站的同時，產生與朋友互相連結、分享資訊、聯絡感情等正面網路外部性，且此外部性隨著社群網站的功能越強大、隱私設定越開放而大幅增加，使用戶使用越開放的平台產生的效用越高。 但此現象同時帶給使用者相對程度的威脅：越開放的平台越無法對隱私權進行有效控制，換言之，越開放的平台越 「不願意」 對隱私權進行規範。隨著新興社群網站漸趨開放，用戶一方面享受朋友高度連結產生的正面效用，另一方面承受失去個人隱私權帶來的負面效用。且當重大侵犯隱私權事件發生，此正面外部性將如同雙面刃般轉化為傷害用戶的利器，其高度的好友連結度反而用戶間無一倖免產生強烈的效用損失。 傳統社群網路不必然會被開放性的新興社群網路所取代，因此本論文分析了純粹社群均衡、雙重均衡與社群優勢均衡的情形等多種社群網路均衡型態。 / This thesis analyzes social network asoption by consumers. The linkage with friends is nodeled as positive network effect. That is , the higher the amount of friends a user connects on a social network site, the higher the extra benefits she derives other than the direct ututility via usage. On the other hand, as new social network sites demonstrate: openness inproves connecting potential but gives way to privacy cncern.A privacy breaching event will rattle the socialty connected group to a drastic degree. Throung the interaction of both the positive and the negative network effects, we find that many types of social network equilibrium can be sustained.