There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

This paper presents control and coordination algorithms for groups of vehicles. The focus is on autonomous vehicle networks performing distributed sensing tasks where each vehicle plays the role of a mobile tunable sensor. The paper proposes gradient descent algorithms for a class of utility functions which encode optimal coverage and sensing policies. The resulting closed-loop behavior is adaptive, distributed, asynchronous, and verifiably correct.

Coverage control for mobile sensing networks

Simulation and the monte carlo method

http://user.it.uu.se/~jarst116/slides/week4.pdf

Graph-Based Algorithms for Boolean Function Manipulation

Accurate and high throughput cell sorting is a critical enabling technology in molecular and cellular biology, biotechnology, and medicine While conventional methods can provide high efficiency sorting in short timescales, advances in microfluidics have enabled the realization of miniaturized devices offering similar capabilities that exploit a variety of physical principles We classify these technologies as either active or passive Active systems generally use external fields (eg, acoustic, electric, magnetic, and optical) to impose forces to displace cells for sorting, whereas passive systems use inertial forces, filters, and adhesion mechanisms to purify cell populations Cell sorting on microchips provides numerous advantages over conventional methods by reducing the size of necessary equipment, eliminating potentially biohazardous aerosols, and simplifying the complex protocols commonly associated with cell sorting Additionally, microchip devices are well suited for parallelization, enabling complete lab-on-a-chip devices for cellular isolation, analysis, and experimental processing In this review, we examine the breadth of microfluidic cell sorting technologies, while focusing on those that offer the greatest potential for translation into clinical and industrial practice and that offer multiple, useful functions We organize these sorting technologies by the type of cell preparation required (ie, fluorescent label-based sorting, bead-based sorting, and label-free sorting) as well as by the physical principles underlying each sorting mechanism

Microfluidic cell sorting: a review of the advances in the separation of cells from debulking to rare cell isolation

This article presents a formal framework for modeling computational genetic regulatory networks as automata, with multi-threshold protein concentration and combinatorial logical gene-protein interactions. By computing the intersection of the languages generated by these automata we obtain the complete set of pathways in a gene network. We illustrate the effectiveness of our framework in the modeling of (i) morphogenesis in Arabidopsis and (ii) regulation in phage lambda

Automaton Models of Computational Genetic Regulatory Networks with Combinatorial Gene-Protein Logical Interactions

The efficiency of conventional heat exchangers is restricted by many factors, such as effectiveness of convective heat transfer and the cost of their operation. The current research deals with these issues by developing a novel method for building a lower-cost yet more efficient heat sink. This method involves using a specially designed curved microchannel to utilise the enhanced fluid mixing characteristics of Dean vortices, and thus transferring heat efficiently.Numerical models have been employed to investigate the heat transfer enhancement of curved channels over straight equivalents, with the aim of optimising the heat exchanger design based on the parameters of maximising heat transfer whilst minimising pressure drop and unit cost. These studies examined the variation of Nusselt Number over the length of the channel, for a range of different curvatures (and hence Dean numbers). The results showed significantly higher heat transfer occurring in curved channels, especially in areas where the generated Dean vortices are strongest, with the variation in Nusselt Number forming the shape of an ‘arc’. In this way, a relationship between the Dean Number and the Nusselt Number is characterised and discussed, leading to suggestions regarding optimal microfluidic heat transfer design.Copyright © 2016 by ASME

Heat Exchanger Improvement via Curved Microfluidic Channels: Part 2 — Investigation Into Heat Transfer Enhancement due to the Dynamics of Dean Vortices

One of the bottlenecks in optical alignment is to actively align multi-axis simultaneously. The Hamiltonian algorithm utilizes the mixing properties of the dynamical system to guide the movement of alignment point to effectively achieves the maximum light intensity positioning with multiple axes. In this paper, the dynamic choices of parameters in Hamiltonian algorithm are proposed to optimize the alignment. Furthermore, a prototype system using this algorithm for fine alignment is developed. Analysis and experiments are presented to show that this system can lead to a relatively fast and stable assembly solution.

A prototype system of optical fiber alignment based on hamiltonian algorithm

The efficiency of conventional heat exchangers is restricted by many factors, such as effectiveness of convective heat transfer and the cost of their operation. The current research deals with these issues by developing a novel method for building a lower-cost yet more efficient heat sink. This method involves using a specially designed curved microchannel to utilise the enhanced fluid mixing characteristics of Dean vortices, and thus transferring heat efficiently.Numerical models have been employed to investigate the heat transfer enhancement of curved channels over straight equivalents, with the aim of optimising the heat exchanger design based on the parameters of maximising heat transfer whilst minimising pressure drop and unit cost. A range of cross-sectional geometries for the curved channels were compared, showing significantly higher Nusselt Numbers than equivalent straight channels throughout, and finding superior performance factors for square, circular and symmetrical trapezoidal profiles. Due the difficulty and expense in manufacturing circular microchannels, the relatively simple to fabricate square and symmetrical trapezoidal channels are put forward as the most advantageous designs. These results take into account both constant wall temperature and constant heat flux conditions. For a given set of channel dimensions, an optimal input flow rate condition is also determined.Copyright © 2016 by ASME

Heat Exchanger Improvement via Curved Microfluidic Channels: Part 1 — Impact of Cross-Sectional Geometry and Channel Design on Heat Transfer Enhancement

This paper presents an approach to optimize the zebrafish-embryo microinjection process by selecting suitable speed trajectories for the motion of the micropipette, with the objective of minimizing the risk of damaging the embryo during the microinjection process. A viscoelastic model of a zebrafish embryo is developed based on experimental data. The speed optimization problem is formulated based on this viscoelastic model. Simulation results indicate that there exists an optimal speed trajectory for the micropipette under certain conditions. The key benefit of this speed optimization approach is that the turgor pressure inside the membrane is prevented from increasing significantly during the microinjection process, thus avoiding damaging the biological components in the embryo.

Peter C. Y. Chen

Papers

Automaton Models of Computational Genetic Regulatory Networks with Combinatorial Gene-Protein Logical Interactions

Heat Exchanger Improvement via Curved Microfluidic Channels: Part 2 — Investigation Into Heat Transfer Enhancement due to the Dynamics of Dean Vortices

A prototype system of optical fiber alignment based on hamiltonian algorithm

Heat Exchanger Improvement via Curved Microfluidic Channels: Part 1 — Impact of Cross-Sectional Geometry and Channel Design on Heat Transfer Enhancement

Speed optimization for micropipette motion during zebrafish embryo microinjection