Three Essays on Auctions

This dissertation studies new bidding behaviors in richer environments where bidders can either communicate or intertemporally interact. We focus on such three perspectives as collusion, strategic information disclosure and intertemporal inference. In the collusion chapter, we propose a framework to investigate the structure of endogenous collusion and show that an endogenously formed ring shall in general be a partial ring. In the informationdisclosure chapter, we study the auctioneer's optimal choice of interperiod information releaseand show the standard sequential Dutch auction or the sequential ¯rst-price auction with the announcement of each stage's winning bid can generate the highest revenue among all considered sequential auction formats. In the intertemporal inference chapter, we suggest a resale explanation for the price path in sequential auctions with multi-unit demand

Uptake and Cytotoxicity of Ce(IV) Doped TiO 2

Ce(IV) doped anatase TiO2 nanoparticles (CDTs) were prepared and the underlying mechanism by which CDT nanoparticle enters into cell and its cytotoxicity were investigated in a human hepatocellular line L02 cell. The results showed that CDTs can enter into cytoplasm of L02 cell via endocytosis and nonendocytic ways. Large aggregation of CDTs went into cell by endocytosis and finally formed an endocytic vesicle with membrane boundary. Tiny aggregation of CDTs entered into cell cytoplasm via channels similar to that for lung-blood substance exchange in the alveolar-airway barrier. In addition, tiny aggregation of CDTs was observed in nucleus, and maybe CDTs could pass through the nucleus envelope via the channels provided by nuclear pore complexes (NPCs). Results from MTT assay, fluorescence microscope, and TEM observations showed that the cell viability, cell morphology, cell growth, and cell division periods could not be obviously impaired when cells were exposed to CDTs of different concentration from 30 to 150 μg mL−1 without UV irradiation. However, large vacuoles containing CDTs were found in cytoplasm, some structure changes were observed in mitochondria, and smooth envelope around the nucleus was shrank and deformed

Information extraction and artwork pricing

Traditional art pricing models often lack fine measurements of painting content. This paper proposes a new content measurement: the Shannon information quantity measured by the singular value decomposition (SVD) entropy of the painting image. Using a large sample of artworks' auction records and images, we show that the SVD entropy positively affects the sales price at 1% significance level. Compared to the other commonly adopted content variables, the SVD entropy has advantages in variable significance, sample robustness as well as model fit. Considering the convenient availability of digital painting images and the straightforward calculation algorithm of this measurement, we expect its wide application in future research

Collaborative Route Planning of UAVs, Workers and Cars for Crowdsensing in Disaster Response

Efficiently obtaining the up-to-date information in the disaster-stricken area is the key to successful disaster response. Unmanned aerial vehicles (UAVs), workers and cars can collaborate to accomplish sensing tasks, such as data collection, in disaster-stricken areas. In this paper, we explicitly address the route planning for a group of agents, including UAVs, workers, and cars, with the goal of maximizing the task completion rate. We propose MANF-RL-RP, a heterogeneous multi-agent route planning algorithm that incorporates several efficient designs, including global-local dual information processing and a tailored model structure for heterogeneous multi-agent systems. Global-local dual information processing encompasses the extraction and dissemination of spatial features from global information, as well as the partitioning and filtering of local information from individual agents. Regarding the construction of the model structure for heterogeneous multi-agent, we perform the following work. We design the same data structure to represent the states of different agents, prove the Markovian property of the decision-making process of agents to simplify the model structure, and also design a reasonable reward function to train the model. Finally, we conducted detailed experiments based on the rich simulation data. In comparison to the baseline algorithms, namely Greedy-SC-RP and MANF-DNN-RP, MANF-RL-RP has exhibited a significant improvement in terms of task completion rate

Four years of multi-modal odometry and mapping on the rail vehicles

Precise, seamless, and efficient train localization as well as long-term railway environment monitoring is the essential property towards reliability, availability, maintainability, and safety (RAMS) engineering for railroad systems. Simultaneous localization and mapping (SLAM) is right at the core of solving the two problems concurrently. In this end, we propose a high-performance and versatile multi-modal framework in this paper, targeted for the odometry and mapping task for various rail vehicles. Our system is built atop an inertial-centric state estimator that tightly couples light detection and ranging (LiDAR), visual, optionally satellite navigation and map-based localization information with the convenience and extendibility of loosely coupled methods. The inertial sensors IMU and wheel encoder are treated as the primary sensor, which achieves the observations from subsystems to constrain the accelerometer and gyroscope biases. Compared to point-only LiDAR-inertial methods, our approach leverages more geometry information by introducing both track plane and electric power pillars into state estimation. The Visual-inertial subsystem also utilizes the environmental structure information by employing both lines and points. Besides, the method is capable of handling sensor failures by automatic reconfiguration bypassing failure modules. Our proposed method has been extensively tested in the long-during railway environments over four years, including general-speed, high-speed and metro, both passenger and freight traffic are investigated. Further, we aim to share, in an open way, the experience, problems, and successes of our group with the robotics community so that those that work in such environments can avoid these errors. In this view, we open source some of the datasets to benefit the research community

Pilot-scale integrated process for the treatment of dry-spun acrylic fiber manufacturing wastewater

An integrated process of membrane bioreactor (MBR)—advanced ozonation (AO)—biological aerated filters (BAFs) was developed for the treatment of dry-spun acrylic fiber manufacturing wastewater in pilot scale. The results show that the removal efficiencies of chemical oxygen demand (COD) and ammonia nitrogen (-N) could exceed 90.0 and 95.0%, respectively. The COD concentration in the total effluent was maintained at 80.0–100 mg/L, and the -N concentration was below 10.0 mg/L. Both the MBR and BAFs could adapt to the influent of practical wastewater after a period of sludge acclimatization. The removal efficiencies of COD and -N in the MBR were maintained at 65.8–71.9 and 59.4–67.5%, respectively. Excitation–emission matrix spectroscopy confirmed that most of the easy degradable organics were removed in the MBR process. After the AO treatment, COD concentration in the wastewater was reduced by 106–157 mg/L and the biodegradability was enhanced. Simultaneous nitrification–denitrification was performed in the biofilm of BAFs, and the removal efficiency of total nitrogen was in the range of 58.2–71.6% after the entire integrated process

Integration of Metabolomics With Pharmacodynamics to Elucidate the Anti-myocardial Ischemia Effects of Combination of Notoginseng Total Saponins and Safflower Total Flavonoids

Notoginseng (Sanqi), the roots and rhizomes of Panax notoginseng and safflower, the flowers of Carthamus tinctorius, are widely used traditional Chinese medicines (TCMs) for the treatment of cardiovascular diseases. Positive evidences have fueled growing acceptance for cardioprotective effects of the combination of the notoginseng total saponins and safflower total flavonoids (CNS) against myocardial ischemia (MI). However, the underlying cardioprotective mechanisms of CNS are still obscured. Metabolomics is a comprehensive tool for investigating biological mechanisms of disease, monitoring therapeutic outcomes, and advancing drug discovery and development. Herein, we investigated the cardioprotective effects of CNS on the isoproterenol (ISO)-induced MI rats by using plasma and urine metabolomics based on ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) and multiple pharmacodynamics approaches. The results showed that pretreatment with CNS could attenuate the cardiac injury resulting from ISO, as evidenced by decreasing the myocardial infarct size, converting the echocardiographic, histopathological, and plasma biochemical abnormalities, and reversing the perturbations of plasma and urine metabolic profiles, particularly for the 55.0 mg/kg dosage group. In addition, 44 metabolites were identified as the potential MI biomarkers, mainly including a range of free fatty acids (FFAs), sphingolipids, and glycerophospholipids. CNS pretreatment group may robustly ameliorate these potential MI-related biomarkers. The accumulation of LysoPCs and FFAs, caused by PLA2, may activate NF-κB pathway and increase proinflammatory cytokines. However, our results showed that CNS at 55.0 mg/kg dosage could maximally attenuate the NF-κB signaling pathway, depress the expressions of TNF-α, IL-6, IL-1β, and PLA2. The results suggested that the anti-inflammatory property of CNS may contribute to its cardioprotection against MI. Our results demonstrate that the integrating of metabolomics with pharmacodynamics provides a reasonable approach for understanding the therapeutic effects of TCMs and CNS provide a potential candidate for prevention and treatment of MI

Complex origins indicate a potential bridgehead introduction of an emerging amphibian invader (Eleutherodactylus planirostris) in China

Identifying the origins of established alien species is important to prevent new introductions in the future. The greenhouse frog (Eleutherodactylus planirostris), native to Cuba, the Bahamas, and the Cayman Islands, has been widely introduced to the Caribbean, North and Central America, Oceania and Asia. This invasive alien amphibian was recently reported in Shenzhen, China, but the potential introduction sources remain poorly understood. Based on phylogenetic analysis using mitochondrial 16S, COI and CYTB sequences, we detected a complex introduction origin of this species, which may be from Hong Kong, China, the Philippines, Panama and Florida, USA, all pointing to a bridgehead introduction. In addition, the nursery trade between the four countries or regions and mainland China from 2011 to 2020 was also significantly higher than other areas with less likelihood of introductions, which supported the molecular results. Our study provides the first genetic evidence of the potential sources of this emerging amphibian invader in mainland China, which may help develop alien species control strategies in the face of growing trade through globalization