This dissertation, which consists of three essays, studies online auctions both theoretically and empirically. The first essay studies a special online auction format used by eBay, “Buy-It- Now” (BIN) auctions, in which bidders are allowed to buy the item at a fixed BIN price set by the seller and end the auction immediately. I construct a two-stage model in which the BIN price is only available to one group of bidders. I find that bidders cutoff is lower in this model, which means, bidders are more likely to accept the BIN option, compared with the models assuming all bidders are offered the BIN. The results explain the high frequency of bidders accepting BIN price, and may also help explain the popularity of temporary BIN auctions in online auction sites, such as eBay, where BIN option is only offered to early bidders. In the second essay, I study how bidders’ risk attitude and time preference affect their behavior in Buy-It-Now auctions. I consider two cases, when both bidders enter the auction at the same time (homogenous bidders) thus BIN option is offered to both of them, and when two bidders enter the auction at two different stages (heterogenous bidders) thus the BIN option is only offered to the early bidder. Bidders’ optimal strategies are derived explicitly in both cases. In particular, given bidders’ risk attitude and time preference, the cutoff valuation, such that a bidder will accept BIN if his valuation is higher than the cutoff valuation and reject it otherwise, is calculated. I find that the cutoff valuation in the case of heterogenous bidders is lower than that in the case of homogenous bidders. The third essay focuses on the empirical modeling of the price processes of online auctions. I generalize the monotone series estimator to model the pooled price processes. Then I apply the model and the estimator to eBay auction data of a palm PDA. The results are shown to capture closely the overall pattern of observed price dynamics. In particular, early bidding, mid-auction draught, and sniping are well approximated by the estimated price curve.

Biodiesel has been suggested as an alternative fuel to the petroleum diesel fuel. It beneficially reduces regulated emission gases, but increases NOx (nitric oxide and nitrogen dioxide) Thus, the increase in NOx is the barrier for potential growth of the biodiesel fuel. In general, NOx formation is dominated by flame temperature. Interestingly, soot can play a role as a heat sink as well as a heat transfer media to high temperature gases. Thus, the cooling effect of soot may change the flame temperature and therefore, NOx emissions. In this study, emphasis is placed on the relationship between soot and NO (Nitric oxide) formation. For the experimental study, a metallic fuel additive is used since barium is known to be effective to suppress soot formation during combustion. The barium additive is applied to #2D (Number 2 diesel fuel) by volume basis: 0.1, 0.25 and 0.5 %-v, and to the palm olein oil by 0.25 %-v. All the tests are carried out in a four-cylinder medium duty diesel engine, 4045 DI diesel engine, manufactured by John Deere. For the analysis, an analytical model is used to estimate combustion temperature, NO concentration and soot emissivity. The results show that NO concentration does not have the expected trade-off relation with soot. Rather, NO concentration is found to be more strongly affected by ambient temperature and combustion characteristics than by soot. The results of the analytical model show the reasonable NO estimation and the improvement on temperature calculation. However, the model is not able to explain the detailed changes of soot emissivity by the different fuels since the emissivity correlation is developed empirically for diesel fuel.

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<p>In this thesis deposit and loan rate-setting equations for chartered banks are derived on the premise that these rates are set so as to maximize the banking industry's profits. Because of the oligopolistic nature of the Canadian banking industry and because explicit collusion is illegal an optimizing model of chartered bank ratesetting behaviour was integrated into the institutional framework of the Canadian banking industry.</p> <p>To do this a two-stage model of the Canadian banking industry is proposed. At the first stage, the prime rate on loans and the rate on non-chequing personal savings deposits are set so as to maximize the collective profits of the industry. To circumvent the illegality of explicit collusion a price leadership model is developed. In this model it is not one of the individual banks which is a price leader, but rather changes in the bank rate act as a signal for all of the individual banks to change their rates. The formulation proposed was tested and the hypothesis accepted for both rates. The second stage of the two-stage model is concerned with asset and liability management and is not developed in this thesis.</p> <p>A second contribution of this thesis is to take into account chartered bank rate-setting behaviour when estimating demand equations for both business loans and nonchequing personal savings deposits. When the estimation procedure used reflects these problems it is found that there are large changes in the values of the estimated coefficients in the demand functions for loans and deposits, compared to the simple O.L.S. estimates of the parameter values.</p> / Doctor of Philosophy (PhD)

In today's fiercely competitive environment, not only in the tourism sector, we see a rise in the need to identify the weak and strong sides of the performance of the entire branch network of a travel agency, as well as of its components, the particular branches. This problem can be approached using the process of benchmarking. This method is currently widely used to compare the similarly behaving systems and processes in all areas of human activity. Data envelopment analysis models can be used as one of the methods of benchmarking. This thesis deals first with the theoretical description of the basic models of data envelopment analysis. It then moves on to concentrate on the description of the network-based models, which are then used in the practical part of the thesis. In this last part, it compares selected travel agency branches and identifies the deficiencies in particular areas of their performance.

國內有關採購案件之決標金額與底價金額之實證研究文獻，多將相關資料逕以迴歸方式直接處理而獲致相關結論，未曾考量樣本偏誤對迴歸結果的影響。本研究利用內政部99年1月至104年8月資訊服務勞務採購案件數據，針對1,061件採購案件資料進行分析，為避免因樣本選擇不當可能產生的估計誤差，我們利用Heckman二階段估計法，先估計押標金對採購案件是否決標的影響，再進一步分析影響決標金額與底價金額的要因。經過選樣誤差修正後，我們發現決標金額與底價金額都有受到選樣誤差的影響，表示過往以計量模型進行決標金額與底價金額影響因素的實證研究，由於未考量押標金的扭曲效果，其研究結果似有再檢視必要。而實證結果也發現，勞務與工程案件之決標金額與底價金額的影響因素並不完全相同，故現行以工程思維為架構的政府採購法，確有再修正之必要。

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Real-world large-scale complex networks such as the Internet, social networks and biological networks have increasingly attracted the interest of researchers from many areas. Accurate modelling of the statistical regularities of these large-scale networks is critical to understand their global evolving structures and local dynamical patterns. Traditionally, the Erdos and Renyi random graph model has helped the investigation of various homogeneous networks. During the past decade, a special computational methodology has emerged to study complex networks, the outcome of which is identified by two models: the Watts and Strogatz small-world model and the Barabasi-Albert scale-free model. At the core of the complex network modelling process is the extraction of characteristics of real-world networks. I have developed computer simulation algorithms for study of the properties of current theoretical models as well as for the measurement of two real-world complex networks, which lead to the isolation of three complex network modelling essentials. The main contribution of the thesis is the introduction and study of a new General Two-Stage growth model (GTS Model), which aims to describe and analyze many common-featured real-world complex networks. The tools we use to create the model and later perform many measurements on it consist of computer simulations, numerical analysis and mathematical derivations. In particular, two major cases of this GTS model have been studied. One is named the U-P model, which employs a new functional form of the network growth rule: a linear combination of preferential attachment and uniform attachment. The degree distribution of the model is first studied by computer simulation, while the exact solution is also obtained analytically. Two other important properties of complex networks: the characteristic path length and the clustering coefficient are also extensively investigated, obtaining either analytically derived solutions or numerical results by computer simulations. Furthermore, I demonstrate that the hub-hub interaction behaves in effect as the link between a network's topology and resilience property. The other is called the Hybrid model, which incorporates two stages of growth and studies the transition behaviour between the Erdos and Renyi random graph model and the Barabasi-Albert scale-free model. The Hybrid model is measured by extensive numerical simulations focusing on its degree distribution, characteristic path length and clustering coefficient. Although either of the two cases serves as a new approach to modelling real-world large-scale complex networks, perhaps more importantly, the general two-stage model provides a new theoretical framework for complex network modelling, which can be extended in many ways besides the two studied in this thesis.

藝術欣賞二階段模型所發現的第二階段美感提升現象，若根據流暢性理論加以解釋，為單純曝光造成流暢性提升而導致的結果，未涉及認知處理歷程的影響，然而情緒評估理論以及Leder等人（2004）的美感經驗與評價歷程神經模型，都強調美感經驗為認知與情感的交互作用。針對上述兩類不同的理論觀點，本研究的目的在於探討認知涉入在美感歷程中的重要性，同時亦嘗試瞭解美感經驗中認知與情緒的關係。本研究讓參與者欣賞不同時代、流派與國家的具象藝術畫作，共分成三個實驗。實驗一收集美感相關情緒詞彙，發展美感情緒量表；實驗二與實驗三延伸Locher等人（2007）之實驗設計，分別收集美感偏好與美感情緒的資料，包含顯性與隱性指標，欲從美感提升現象中檢驗認知涉入對兩種美感歷程產物的影響力。實驗二關心美感偏好隨時間的變化，結果顯示認知涉入有助於偏好的提升，而隱性偏好亦有相似的趨勢；實驗三則發現美感情緒並沒有隨呈現時間增加而提升，而認知涉入的影響力也較不明顯，臉部EMG測量則未能反映出隱性美感情緒。本研究也發現，國畫較西畫更顯著地出現美感偏好或情緒的提升現象且較受認知涉入影響，此外，主觀偏好與不偏好的西畫在美感偏好與正向情緒類別之結果中，皆有類似適應的效果，其中主觀偏好畫作隨時間增長而正向情緒減少、負向情緒增加。綜合而言，本研究結果支持認知涉入為美感偏好提升之要素，但是無法確認認知與情緒兩者之間的互動關係，此外，藝術欣賞的第二階段不只有美感提升的現象，亦有美感下降的現象。 / The increase of aesthetic preference over viewing time was found in the study of the two-stage model of art appreciation. This phenomenon could be interpreted by mere exposure effect on improvement of fluency, not involving the influence from the cognitive processes. However, some theories (Silvia, 2011; Leder et al., 2004) emphasized the interaction between cognition and emotion in aesthetic experience. Based on these two kinds of theoretical perspective, the purpose of this study is to explore the role of cognitive involvement in aesthetic processes, and to understand the relationship between cognition and emotion in aesthetic experience. There are three experiments in this study, using the figurative art paintings from different era, genre and countries as the material. In Experiment 1, the emotional adjectives were collected to develop the scale of aesthetic emotion. In Experiment 2 and 3, the effects of cognitive involvement on aesthetic preference and emotion were tested, respectively. We extended the experiment design from Locher et al. (2007) to manipulate the degree of cognitive involvement additionally, with both the explicit and implicit indexes measured. Overall, the results showed that cognitive involvement helped the increase of preference, but not of emotion, because there was no increase of emotion founded. In addition, the effect of cognitive involvement in Chinese paintings was more obvious than that in West paintings. We also found that there could be adaptation effect in aesthetic process. In conclusion, the importance of cognitive involvement in preference increase was supported. But we cannot confirm the interaction between cognition and emotion. In addition, not only the increase of aesthetic preference and emotion, but also the decrease of them could be found in the second stage of art appreciation.