226 research outputs found
Optical phase cloaking of 700-nm light waves in the far field by a three-dimensional carpet cloak
Transformation optics is a design tool that connects geometry of space and
propagation of light. Invisibility cloaking is a corresponding benchmark
example. Recent experiments at optical frequencies have demonstrated cloaking
for the light amplitude ("ray cloaking"). In this Letter, we demonstrate
far-field cloaking of the light phase ("wave cloaking") by interferometric
microscope-imaging experiments on the previously introduced three-dimensional
carpet cloak at 700-nm wavelength and for arbitrary polarization of light
Three-dimensional direct laser writing inspired by stimulated-emission-depletion microscopy
Three-dimensional direct laser writing has become a well established,
versatile, widespread, and even readily commercially available "workhorse" of
nano- and micro-technology. However, its lateral and axial spatial resolution
is inherently governed by Abbe's diffraction limitation - analogous to optical
microscopy. In microscopy, stimulated-emission-depletion approaches have lately
circumvented Abbe's barrier and lateral resolutions down to 5.6 nm using
visible light have been achieved. In this paper, after very briefly reviewing
our previous efforts with respect to translating this success in optical
microscopy to optical lithography, we present our latest results regarding
resolution improvement in the lateral as well as in the much more relevant
axial direction. The structures presented in this paper set a new
resolution-benchmark for next-generation direct-laser-writing optical
lithography. In particular, we break the lateral and the axial Abbe criterion
for the first time
08351 Abstracts Collection -- Evolutionary Test Generation
From September 24th to September 29th 2008 the Dagstuhl Seminar
08351 ``Evolutionary Test Generation \u27\u27 was held
in Schloss Dagstuhl~--~Leibniz Center for Informatics.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
CeCar: A platform for research, development and education on autonomous and cooperative driving
International audienceIn this paper, we introduce CeCar as an affordable model-car based platform supporting research, development and education in the field of autonomous and cooperative driving. We present the application-oriented use cases and key platform requirements , and explain the logical and technical architecture of the CeCar platform, alongside with details on the underlying mod-ularity concept. Subsequently, we introduce CeCar application scenarios for the areas research, development and education, and provide relevant application examples. Further, we discuss the CeCar platform concept in comparison with other model-car based education and research platforms, and outline planned future work on the CeCar platform
Evolutionary testing supported by slicing and transformation
Evolutionary testing is a search based approach to the automated generation of systematic test data, in which the search is guided by the test data adequacy criterion. Two problems for evolutionary testing are the large size of the search space and structural impediments in the implementation of the program which inhibit the formulation of a suitable fitness function to guide the search. In this paper we claim that slicing can be used to narrow the search space and transformation can be applied to the problem of structural impediments. The paper presents examples of how these two techniques have been successfully employed to make evolutionary testing both more efficient and more effective
A post-placement side-effect removal algorithm
Side-effects are widely believed to impede program comprehension and have a detrimental effect upon software maintenance. This paper introduces an algorithm for side-effect removal which splits the side-effects into their pure expression meaning and their state-changing meaning. Symbolic execution is used to determine the expression meaning, while transformation is used to place the state-changing part in a suitable location in a transformed version of the program. This creates a program which is semantically equivalent to the original but guaranteed to be free from side-effects. The paper also reports the results of an empirical study which demonstrates that the application of the algorithm causes a significant improvement in program comprehension
Fasudil Loaded PLGA Microspheres as Potential Intravitreal Depot Formulation for Glaucoma Therapy
Rho-associated protein kinase (ROCK) inhibitors allow for causative glaucoma therapy. Unfortunately, topically applied ROCK inhibitors suffer from high incidence of hyperemia and low intraocular bioavailability. Therefore, we propose the use of poly (lactide-co-glycolide) (PLGA) microspheres as a depot formulation for intravitreal injection to supply outflow tissues with the ROCK inhibitor fasudil over a prolonged time. Fasudil-loaded microspheres were prepared by double emulsion solvent evaporation technique. The chemical integrity of released fasudil was confirmed by mass spectrometry. The biological activity was measured in cell-based assays using trabecular meshwork cells (TM cells), Schlemm's canal cells (SC cells), fibroblasts and adult retinal pigment epithelium cells (ARPE-19). Cellular response to fasudil after its diffusion through vitreous humor was investigated by electric cell-substrate impedance sensing. Microspheres ranged in size from 3 to 67 mu m. The release of fasudil from microspheres was controllable and sustained for up to 45 days. Released fasudil reduced actin stress fibers in TM cells, SC cells and fibroblasts. Decreased collagen gel contraction provoked by fasudil was detected in TM cells (similar to 2.4-fold), SC cells (similar to 1.4-fold) and fibroblasts (similar to 1.3-fold). In addition, fasudil readily diffused through vitreous humor reaching its target compartment and eliciting effects on TM cells. No negative effects on ARPE-19 cells were observed. Since fasudil readily diffuses through the vitreous humor, we suggest that an intravitreal drug depot of ROCK inhibitors could significantly improve current glaucoma therapy particularly for patients with comorbid retinal diseases
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