STRUCTURES AND REACTIONS OF BIOMOLECULES AT INTERFACES

This dissertation serves to study a protein\u27s conformation-function relationship since immobilized proteins often behave differently from their solution-state counterparts. Therefore, this study is important to the application of protein-based biodevices. Another aim of this dissertation is to explore a new approach to realize low voltage electrowetting without the help of oil bath. Utilizing this approach, a protein micro-separation was realized. Additionally, the interfacial properties of ionic liquid (IL) solid-like layer, which played a key role in electrowetting, was studied for further developments of IL-based applications. Atomic Force Microscopy (AFM) was utilized in the study and played multiple roles in this dissertation. First, AFM was used as a fabrication tool. In the contact mode, conductive AFM tip was used to conduct the electrochemical oxidation to create a chemical pattern or to conduct an electrowetting experiment. Subsequently, AFM was used as a characterization tool in the tapping mode to characterize the surface structure, the thickness, and the surface potential. Furthermore, AFM in the contact mode was used as a measurement tool to measure the tribological force properties of sample. The results of the study concerning the conformational change in immobilized calmodulin showed that the immobilized CaM retained its activity. Additionally, the immobilization of CaM on a solid support did not interfere with the ability of the protein to bind calcium, as well as CaM kinase binding domain. For the electrowetting experiment, our data suggested that the ultra-high capacitance density of the IL dielectric layer leads to the low voltage electrowetting. We also successfully demonstrated the streptavidin and GFP proteins separation by Electrowetting-on-Dielectric (EWOD) force. The results of the surface properties study indicated that the charge and dipole of the substrate can influence the structures and properties of the IL interfacial layer. Our study would be beneficial in research and assay work involving engineered proteins, as well as the study and development of electrowetting applications

Editorial: Optimisation methods of road pricing

Toll charges are classified into congestion tolls (congestion pricing) and road tolls (private pricing) respectively, according to the purpose of pricing. Congestion pricing is used to mitigate network congestion by shifting traffic flow from peak periods to off-peak periods, from congested routes to less congested routes, or from private cars to public transport. Private toll pricing is used to recoup construction or maintenance costs of road links, when they are built fully or partially on private investment. This special issue reports some recent developments in road pricing. Three papers investigate congestion pricing, and one paper deals with toll adjustment for road franchising. The optimisation models and theoretical findings might be useful and meaningful for future research on road pricing

Data mining approaches for detecting intrusion using UNIX process execution traces

Intrusion detection systems help computer systems prepare for and deal with malicious attacks. They collect information from a variety of systems and network sources, then analyze the information for signs of intrusion and misuse. A variety of techniques have been employed to analyze the information from traditional statistical methods to new emerged data mining approaches. In this thesis, we describe several algorithms designed for this task, including neural networks, rule induction with C4.5, and Rough sets methods. We compare the classification accuracy of the various methods in a set of UNIX process execution traces. We used two kinds of evaluation methods. The first evaluation criterion characterizes performances over a set of individual classifications in terms of average testing accuracy rate. The second measures the true and false positive rates of the classification output over certain threshold. Experiments were run on data sets of system calls created by synthetic sendmail programs. There were two types of representation methods used. Different combinations of parameters were tested during the experiment. Results indicate that for a wide range of conditions, Rough sets have higher classification accuracy than that of Neural networks and C4.5. In terms of true and false positive evaluations, Rough sets and Neural networks turned out to be better than C4.5

Low Voltage Electrowetting Device and Method for Making Same

An electrowetting device includes a substrate having a first face, a charged adhesion layer immobilized on the first face of the substrate and a dielectric layer bound to the charged adhesion layer. An unbound ionic liquid phase contacts the dielectric layer

Megaregional Passenger Transportation Hub Location Problem Considering Congestion Effects

The need to make effective plans for locating transportation hubs is of increasing importance in the megaregional area, as recent research suggests that the growing intercity travel demand affects the efficiency of a megaregional transportation system. This paper investigates a hierarchical facility location problem in a megaregional passenger transportation network. The aim of the study is to determine the locations of hub facilities at different hierarchical levels and distribute the demands to these facilities with minimum total cost, including investment, transportation, and congestion costs. The problem is formulated as a mixed-integer nonlinear programming model considering the service availability structure and hub congestion effects. A case study is designed to demonstrate the effectiveness of the proposed model in the Wuhan metropolitan area. The results show that the congestion effects can be addressed by reallocating the demand to balance the hub utilisation or constructing new hubs to increase the network capacity. The methods of appropriately locating hubs and distributing traffic flows are proposed to optimise the megaregional passenger transportation networks, which has important implications for decision makers