Methodological and empirical challenges in modelling residential location choices

The modelling of residential locations is a key element in land use and transport planning. There are significant empirical and methodological challenges inherent in such modelling, however, despite recent advances both in the availability of spatial datasets and in computational and choice modelling techniques. One of the most important of these challenges concerns spatial aggregation. The housing market is characterised by the fact that it offers spatially and functionally heterogeneous products; as a result, if residential alternatives are represented as aggregated spatial units (as in conventional residential location models), the variability of dwelling attributes is lost, which may limit the predictive ability and policy sensitivity of the model. This thesis presents a modelling framework for residential location choice that addresses three key challenges: (i) the development of models at the dwelling-unit level, (ii) the treatment of spatial structure effects in such dwelling-unit level models, and (iii) problems associated with estimation in such modelling frameworks in the absence of disaggregated dwelling unit supply data. The proposed framework is applied to the residential location choice context in London. Another important challenge in the modelling of residential locations is the choice set formation problem. Most models of residential location choices have been developed based on the assumption that households consider all available alternatives when they are making location choices. Due the high search costs associated with the housing market, however, and the limited capacity of households to process information, the validity of this assumption has been an on-going debate among researchers. There have been some attempts in the literature to incorporate the cognitive capacities of households within discrete choice models of residential location: for instance, by modelling households’ choice sets exogenously based on simplifying assumptions regarding their spatial search behaviour (e.g., an anchor-based search strategy) and their characteristics. By undertaking an empirical comparison of alternative models within the context of residential location choice in the Greater London area this thesis investigates the feasibility and practicality of applying deterministic choice set formation approaches to capture the underlying search process of households. The thesis also investigates the uncertainty of choice sets in residential location choice modelling and proposes a simplified probabilistic choice set formation approach to model choice sets and choices simultaneously. The dwelling-level modelling framework proposed in this research is practice-ready and can be used to estimate residential location choice models at the level of dwelling units without requiring independent and disaggregated dwelling supply data. The empirical comparison of alternative exogenous choice set formation approaches provides a guideline for modellers and land use planners to avoid inappropriate choice set formation approaches in practice. Finally, the proposed simplified choice set formation model can be applied to model the behaviour of households in online real estate environments.Open Acces

Thermodynamic states of adsorbed hydrogen at noble-metal electrocatalysts in absence/presence of chemisorbed sulfur

The experimental and theoretical research on the hydrogen under-potential deposition (UPD) on Rh and Pt electrodes has led to determination of the Gibbs free energy ([delta]G[subscript ads]), the standard entropy ([delta]S[omicron][subscript ads]) and the standard enthalpy ([delta]H[omicron][subscript ads]) of adsorption based on a general adsorption isotherm rederived in the course of this work. The research has resulted in development of theoretical methodology allowing to evaluate, for the first time, the bond energy between the metal substrate, M, and the under-potential deposited H (H[subscript UPD]), E[subscript M]-[subscript H][subscript UPD] (here M = Pt or Rh). The impact of the specifically adsorbed anions on [delta]G[subscript ads], [delta]S[omicron][subscript ads] and [delta]H[omicron][subscript ads] has also been studied. Theoretical treatment of the experimental data based on the general electrochemical adsorption isotherm has allowed elucidation of [delta]G[subscript ads] as a function of the temperature, T, and the H surface coverage, [thêta][subscript H][subscript UPD]. The experimentally evaluated value of E[subscript M]-[subscript H][subscript UPD] is close to that of the bond energy between M and the chemisorbed H (H[subscript chem]). Proximity of the magnitude of E[subscript M]-[subscript H][subscript UPD] to that of E[subscript M]-[subscript H][subscript chem] (here M = Pt or Rh) points to the similar binding mechanism of H under the conditions involving presence of the electrified solid/liquid interface. Closeness of E[subscript M]-[subscript H][subscript UPD] to E[subscript M]-[subscript H][subscript chem] might also point to the same adsorption site of the two distinct H surface species, thus indicating that H[subscript UPD] alike H[subscript chem] is strongly embedded in the surface lattice of the Rh and Pt substrates. Temperature-dependent research on the UPD H and anion adsorption on Pt(111) and Pt(100) in 0.5 M aqueous H[subscript 2]SO[subscript 4] solution by cyclic-voltammetry, cv, conducted for the first time ever, indicates that the overall adsorption/desorption charge density is affected by temperature variation. An analysis of the [delta]G[subscript ads] (H [subscript UPD]) versus [thêta][subscript H][subscript UPD] plots reveal that the UPD H follows the Frumkin isotherm and the energy of lateral repulsions, [oméga], and the respective dimensionless parameter g are coverage independent. The value of E[subscript Pt(111)]-[subscript H][subscript UPD] is close to the surface bond energy between the chemisorbed H, H[subscript chem], and Pt(111), E[subscript Pt(111)]-[subscript H][subscript chem]. The influence of submonolayers of chemisorbed sulfur, S [subscript chem], on the UPD H on Pt(poly) and Pt(111) electrodes was studied. The research has demonstrated that a monolayer of S [subscript chem] on Pt can be formed by its immersion in aqueous Na[subscript 2]S solution. The S[subscript chem] can be gradually removed through oxidative desorption and its coverage can be controlled with the precision of some 1-2% of a mono layer. Theoretical treatment of the experimental results indicates that a submonolayer of S[subscript chem] having the nominal coverage of 0.10 increases the Gibbs free energy, the entropy and the enthalpy of adsorption for H[subscript UPD]. The bond energy between Pt and H[subscript UPD] decreases in presence of S[subscript chem] and the effect is brought about by local electron withdrawing effects that propagate through the underlying metal which acts as a mediator."--Résumé abrégé par UM

Text mining approach to explore dimensions of national parks visitors’ experience and satisfaction using online customer reviews

Natural parks are gaining global popularity with millions of visits per year. However, studies evaluating park visitors\u27 experiences, satisfaction, and motivations are limited to traditional methods, such as direct observations, spatial analysis using global positioning system (GPS) trackers, interviews, surveys, and focus groups. As an alternative to these conventional methods, user-generated content (UGC) provides available, easily accessible, and consumers\u27 reliable recent experiences with services. This study investigated visitors\u27 reviews of selected Canadian national parks to explore the dimensions of the visitors\u27 quality of experience and the drivers of satisfaction based on online ratings on the Trip Advisor website. The analysis yielded various topics ranging from visitors\u27 pleasant feelings about trails, mountain views, and water activities to their unpleasant experiences regarding food, crowds, lineups, and parking lots. Besides, analysis of the reviews based on the reviewers\u27 start ratings highlighted the most important drivers of satisfaction and dissatisfaction between them. Findings suggest that topics related to schedule and weather-related hassles; food, tickets, and shopping experiences; and visitor information center and exhibitions were among the most distinguishes dissatisfied visitors (1- and 2-star) from others. On the other hand, positive vibes, expressiveness, photography opportunities, and daytime and weather experience were the principal determinants of visitors\u27 satisfaction (4- and 5-star)

Effect of an Integrated Cognitive-Behavioral, Acceptance, and Commitment Intervention on Generalized Anxiety Disorder among University Students

Background and Objective: Regarding the importance of generalized anxiety disorder, this study aimed to investigate the effect of an integrated cognitive-behavioral, acceptance, and commitment intervention on generalized anxiety disorder among students of Islamic Azad University of Toyserkan, Iran. Materials and Methods: This interventional study was conducted on 18 students referring to the counseling center of Toyserkan Azad University to receive counseling services using a pretest-posttest design in 2017. The study population was selected by a psychiatrist based on the diagnostic and statistical manual of mental disorder criteria through convenience sampling technique. The data were collected using a two-part questionnaire, including the demographic information and Standardized Beck Depression Inventory. The integrated program consisted of 12 educational sessions. Data analysis was performed in SPSS software (version 16) by means of paired sample t-test and Chi-square test. Results: According to the results, the integrated intervention reduced the student's mean generalized anxiety disorder to 8.27%. Moreover, this intervention led to anxiety reduction from severe level to moderate level in 83.3% of the students. Conclusion: As the findings of the present study indicated, the integrated intervention was effective in the mitigation of generalized anxiety disorder symptoms among the students. Therefore, this intervention was concluded to be as efficient as other interventions, such as the cognitive-behavioral, acceptance, and commitment programs, in decreasing the symptoms of generalized anxiety disorder

Inter-sectoral cooperation model (Study: Mosque-School-Family Cooperation)

ضرورت و هدف اصلی: لازمه تحقق اهداف تربیتی اسلام، همگرایی ارکان تربیتی جامعه اسلامی است. تعامل مدرسه (به­عنوان اصلی‌ترین نهاد تربیت رسمی در کشور)، خانواده (به­عنوان طبیعی‌ترین و پایدارترین نهاد) و مسجد (به­عنوان اصیل‌ترین نهاد تربیتی در جامعه اسلامی) موجب هم­افزایی و تسهیل تحقق اهداف تربیتی اسلام می­گردد. از سوی دیگر این سه رکن تربیتی(مسجد، مدرسه و خانواده) از مؤلفه‌های اساسی ارتباط سنتی می‌باشند و تحقق همکاری این ارکان،‌ تأثیری قابل­توجه بر تقویت شبکه ارتباطات اجتماعی و تعمیق باورهای ملی و دینی خواهد داشت. روش پژوهش: پژوهش حاضر از نوع کیفی بوده و در آن از راهبرد نظریه­پردازی داده­بنیاد استفاده شده است. داده‌های پژوهش از نتایج موردکاوی چهارده مسجد برتر در کشور در حوزه تعامل با خانواده‌ و مدرسه استخراج شده است. یافته‌ها: همکاری مسجد با مدرسه و خانواده پدیده‌ای محوری است که شرایط علّی آن را ظرفیت‌ها و ضعف‌های نهادهای تربیتی تشکیل می‌دهند و برای تحقق آن باید به زمینه‌های آن که بایسته‌های برنامه‌ای، ساختاری و سرمایه انسانی است، توجه شود. این پدیده دارای مراحل چهارگانه: «1-زمینه‌سازی و اعتمادسازی، 2- جذب از مدرسه به مسجد، 3-تداوم ارتباط و تربیت در مسجد، 4-نقش‌آفرینی دانش­آموزان در مسجد و مدرسه» است که مؤلفه‌هایی در قالب عوامل مداخله‌گر بر آن اثر‌گذار می‌باشند و نتایجی را به دنبال خواهند داشت. الگوی حاصل از روابط مقوله‌های تحقیق در مدلی پارادایمی نمایش داده شده است

Demulsification techniques of water-in-oil and oil-in-water emulsions in petroleum industry

The difficulties associated with transportation and refining of crude oil emulsions and produced water discharge limitations are among the conspicuous clues that have led the oilfield researchers to probe into practical demulsification methods for many decades. Inconsistent research outcomes observed in the literature for a particular demulsification method of a typical emulsion (i.e., water-in-oil or oil-in-water) arise not only from the varied influential parameters associated (such as salinity, temperature, pH, dispersed phase content, emulsifier/demulsifier concentration, and droplet size) but also from the diverse types of emulsion constituents (namely oil, surfactant, salt, alkali, polymer, fine solids, and/or other chemicals/impurities). Being the main component in formation of stabilizing interfacial film surrounding the dispersed phase droplets, surfactant is the most predominant contributor to emulsion stability, extent of which depends on its nature (being ionic or nonionic, and its degree of hydrophilicity/lipophilicity), concentration, and interaction with other surface-active agents in the emulsion as well as on the salinity, temperature, and pH of the system. In this paper, it is endeavored to overview some of the most commonly exploited demulsification techniques (i.e., chemical, biological, membrane, electrical, and microwave irradiation) of both oilfield and synthetic emulsions, taking into account the emulsion-stabilizing and -destabilizing effects with regard to the dominant parameters plus the emulsion composition. Further, the variations occurring in interfacial properties of emulsions by demulsification process are discussed. Finally, the mechanism(s) involved in emulsions resolution achieved by each method is elucidated. Clearly, the most efficient demulsification approach is the one able to attain desirable separation efficiency while complying with the environmental regulations and imposing the least economic burden on the petroleum industry

An Experimental Study of CO2-low Salinity Water Alternating Gas Injection in Sandstone Heavy Oil Reservoirs

Several studies have shown that oil recovery significantly increased by low salinity water flooding (LSWF) in sandstones. However, mechanism of oil recovery improvement is still controversial. CO2 that develops buffer in presence of water is expected as a deterrent factor in LSWF efficiency based on mechanism of IFT reduction due to pH uprising. No bright evidence in literature supports this idea.  Here, a set of core floods including a pair of CO2 WAG and a pair of water injection tests are conducted and, the efficiency of LSWF and high salinity water flooding (HSWF) were compared for each pair. HSWF was followed by LSWF in tertiary mode. Results showed that not only CO2 does not deteriorate LSWF recovery efficiency, but also improves recovery. Since CO2-low salinity WAG showed best performance among types by constant pore volume injected. Positive results in both secondary and tertiary modes with Kaolinite free samples used here showed that Kaolinite release is not the critical phenomenon in LSWF brisk performance. Also different pressure behaviour of CO2 WAG processes in comparison with reported behaviour of LSWF proves that LSWF performance may not depend on how pressure changes through flooding