Complete gradient-LC-ESI system on a chip for protein analysis

This paper presents the first fully integrated gradient-elution liquid chromatography-electrospray ionization (LC-ESI) system on a chip. This chip integrates a pair of high-pressure gradient pumps, a sample injection pump, a passive mixer, a packed separation column, and an ESI nozzle. We also present the successful on-chip separation of protein digests by reverse phase (RP)-LC coupled with on-line mass spectrometer (MS) analysis

Simulation of valveless micropump and mode analysis

In this work, a 3-D simulation is performed to study for the solid-fluid coupling effect driven by piezoelectric materials and utilizes asymmetric obstacles to control the flow direction. The result of simulation is also verified. For a micropump, it is crucial to find the optimal working frequency which produce maximum net flow rate. The PZT plate vibrates under the first mode, which is symmetric. Adjusting the working frequency, the maximum flow rate can be obtained. For the micrpump we studied, the optimal working frequency is 3.2K Hz. At higher working frequency, say 20K Hz, the fluid-solid membrane may come out a intermediate mode, which is different from the first mode and the second mode. It is observed that the center of the mode drifts. Meanwhile, the result shows that a phase shift lagging when the excitation force exists in the vibration response. Finally, at even higher working frequency, say 30K Hz, a second vibration mode is observed.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Optimal Mechanical Design with Robust Performance by Fuzzy Formulation Strategy

[[abstract]]This paper presents an optimum design methodology for obtaining the highest robust performance using fuzzy multi-objective formulation strategy. The target performance and its variation, as functions of normally distributed variables with stochastic independence, are simultaneously minimized in this design process. A functional representation of the variability of the performance and the computational algorithm of the robust design process are presented in the paper. Two categories of design problems are examined: (1) the robust design with expected target of minimal variation. (2) The robust design with optimized target of minimal variation. The strength-based reliability behaves as the design objective that was merged in the formulation to extend the application of the proposed method. Three mechanical design examples further illustrate the presented integrated design methodology and successfully show its advantage.[[notice]]補正完畢[[incitationindex]]E

Multiobjective fuzzy optimization with random variables in a mix of fuzzy and probabilistic environment

[[abstract]]The fuzzy λ-formulation is used to solve multiobjective optimization problems in which the design variables are random, the constraints as a whole has a fuzzy probability or the constraints are mixed of deterministic, stochastic and fuzzy constraints. The fuzzy optimization strategy helps one to get the highest degree of satisfaction in reaching an optimum solution. The idea of expected value and the chance constrained programming technique allows one to convert a stochastic optimization problem into its equal deterministic form. The design of a three-bar truss illustrates the proposed design optimization in detail and the design of a machine-tool spindle express the comprehensive work of this technique. Results show that the proposed formulation and method can generate a natural, well-behaved, and reliable design[[conferencetype]]國際[[conferencedate]]19950320~19950324[[iscallforpapers]]Y[[conferencelocation]]Yokohama, Japa

Level-cut approaches of first and second kind for unique solution design in fuzzy engineering optimization problems

[[abstract]]Two single level-cut approaches of the first and second kind for obtaining the unique compromise design in solving nonlinear optimum engineering design problems with fuzzy resources have been developed and presented in this paper. The conventional standard level-cuts method has been discussed for inspiring the proposed novel formulation consequently. The proposed strategies with the illustrative design examples indicate that the unique design as well as corresponding optimum level-cut value can be guaranteed obtained. Additionally, two wide-applicable linear or nonlinear membership functions of objective functions are presented depending on the practical situations of design tasks. The proposed level-cut approaches have been shown easy formulation and successfully employed to large-scaled structural design problems by sequential quadratic programming (SQP) technique combined with the finite element analysis.[[notice]]補正完畢[[journaltype]]國內[[incitationindex]]E

Batalin-Vilkovisky Integrals in Finite Dimensions

The Batalin-Vilkovisky method (BV) is the most powerful method to analyze functional integrals with (infinite-dimensional) gauge symmetries presently known. It has been invented to fix gauges associated with symmetries that do not close off-shell. Homological Perturbation Theory is introduced and used to develop the integration theory behind BV and to describe the BV quantization of a Lagrangian system with symmetries. Localization (illustrated in terms of Duistermaat-Heckman localization) as well as anomalous symmetries are discussed in the framework of BV.Comment: 35 page

A Hybrid Framework for Multi-Vehicle Collision Avoidance

With the recent surge of interest in UAVs for civilian services, the importance of developing tractable multi-agent analysis techniques that provide safety and performance guarantees have drastically increased. Hamilton-Jacobi (HJ) reachability has successfully provided these guarantees to small-scale systems and is flexible in terms of system dynamics. However, the exponential complexity scaling of HJ reachability with respect to system dimension prevents its direct application to larger-scale problems where the number of vehicles is greater than two. In this paper, we propose a collision avoidance algorithm using a hybrid framework for N+1 vehicles through higher-level control logic given any N-vehicle collision avoidance algorithm. Our algorithm conservatively approximates a guaranteed-safe region in the joint state space of the N+1 vehicles and produces a safety-preserving controller. In addition, our algorithm does not incur significant additional computation cost. We demonstrate our proposed method in simulation.Comment: Submitted to IEEE Conference on Decision and Control, 201

New high-efficiency source of photon pairs for engineering quantum entanglement

We have constructed an efficient source of photon pairs using a waveguide-type nonlinear device and performed a two-photon interference experiment with an unbalanced Michelson interferometer. Parametric down-converted photons from the nonlinear device are detected by two detectors located at the output ports of the interferometer. Because the interferometer is constructed with two optical paths of different length, photons from the shorter path arrive at the detector earlier than those from the longer path. We find that the difference of arrival time and the time window of the coincidence counter are important parameters which determine the boundary between the classical and quantum regime. When the time window of the coincidence counter is smaller than the arrival time difference, fringes of high visibility (80$\pm$ 10%) were observed. This result is only explained by quantum theory and is clear evidence for quantum entanglement of the interferometer's optical paths.Comment: 4 pages, 4 figures, IQEC200

A signature of the donor star in the extra-galactic X-ray binary LMC X-2

Two nights of phase-resolved medium-resolution Very Large Telescope spectroscopy of the extra-galactic low-mass X-ray binary LMCX-2 have revealed a 0.32 +/- 0.02 d spectroscopic period in the radial velocity curve of the He II lambda 4686 emission line that we interpret as the orbital period. However, similar to previous findings, this radial velocity curve shows a longer term variation that is most likely due to the presence of a precessing accretion disc in LMCX-2. This is strengthened by He II lambda 4686 Doppler maps that show a bright spot that is moving from night to night. Furthermore, we detect narrow emission lines in the Bowen region of LMCX-2, with a velocity of K-em = 351 +/- 28 km s(-1), that we tentatively interpret as coming from the irradiated side of the donor star. Since K-em must be smaller than K-2, this leads to the first upper limit on the mass function of LMCX-2 of f(M-1) >= 0.86 M-circle dot (95 per cent confidence), and the first constraints on its system parameters