Abstract— The primary goal of this study was to find a measurement method for motion blur which is easy to carry out and gives results that can be reproduced from one lab to another. This method should be able to also take into account methods for reduction of motion blur such as backlight flashing. Two methods have been compared. The first method uses a high‐speed camera that permits us to directly picture the blurred‐edge profile. The second one exploits the mathematical analysis of the motion‐blur formation to construct the blurred‐edge profile from the temporal step response. Measurement results and method proposals are given and discussed. 相似文献
Model calculations on the ellipsometric memory are presented. The ellipsometric memory is an n-bit optical memory whose information is extracted by use of the ellipsometric principle. The memory cells of the device consist of thin-film multilayer structures, and the information of each memory cell is contained in the optical properties of the thin films. Several thin-film multilayer structures were examined in order to find out how different choices of layer materials and other system parameters such as layer thicknesses and wavelength affect resolutions and limitations of the ellipsometric memory. Such calculations are also useful for optimizing the readout resolution. It was found that it is possible to use memory cells having up to at least eight layers, which would permit 8-bit words to be stored at each location. It was also found that, in principle, several types of materials can be used as layer materials, and various aspects of different choices of materials are discussed. 相似文献
Grain size and lattice distortions as a function of milling time have been determined using X-ray peak broadening analysis and Brunauer-Emmett-Teller (BET) measurements. The grain size decreases from 0.22 m in unmilled samples to 0.06 m at 25 h milling time. Prolonged milling produced no further decrease of the grain size. The unmilled powder contained lattice distortions of 0.06%. During the first 25 h of milling only small changes of the lattice distortions occurred; longer milling times resulted in a rapid increase of the lattice distortions. At 47 h of milling, the lattice distortions had increased to about 0.11%. The results obtained by BET measurements agreed well with those obtained by X-ray analysis. No anisotropic grain size decrease was indicated during milling. 相似文献
A national multicentre study was performed to investigate the prevalent use of "alternative medicine", here called "non-proven therapies (NPT)", applied among Norwegian cancer patients. Of 911 patients invited to take part in the study, 642 were included in the analysis. Demographic characteristics were collected for all patients. The participating physicians gave information about the patients' clinical characteristics. Among 630 evaluable patients, 20% had been or were present users of NPTs for their oncological disease. The preferred methods were healing by hand and faith healing. Herbs, vitamins, diets and Iscador were other popular methods. As many as 40% of the users of NPTs had used NPTs earlier for non-malignant diseases. Elderly patients were less likely to use NPTs. Use was high in the northern part of Norway. 相似文献
IT systems pervade our society more and more, and we become heavily dependent on them. At the same time, these systems are increasingly targeted in cyberattacks, making us vulnerable. Enterprise and cybersecurity responsibles face the problem of defining techniques that raise the level of security. They need to decide which mechanism provides the most efficient defense with limited resources. Basically, the risks need to be assessed to determine the best cost-to-benefit ratio. One way to achieve this is through threat modeling; however, threat modeling is not commonly used in the enterprise IT risk domain. Furthermore, the existing threat modeling methods have shortcomings. This paper introduces a metamodel-based approach named Yet Another Cybersecurity Risk Assessment Framework (Yacraf). Yacraf aims to enable comprehensive risk assessment for organizations with more decision support. The paper includes a risk calculation formalization and also an example showing how an organization can use and benefit from Yacraf.
In this study, effects of embossing temperature, time, and force on production of a microfluidic device were investigated. Polymethyl methacrylate (PMMA) substrates were hot embossed by using a micromilled aluminum mold. The process parameters were altered to observe the variation of replication rate in width and depth as well as symmetry of the replicated microfluidic channels. Analysis of variance (ANOVA) on the experimental results indicated that embossing temperature was the most important process parameter, whereas embossing time and force have less impact. One distinguishing aspect of this study is that, the channels were observed to be skewed to either side of the channel depending on the location of the protrusions on the mold. The mechanism of the skewness was investigated by finite element analysis and discussed in detail. Results showed that the skewness depends on the flow characteristics of the material and could be reduced by increasing the embossing temperature. The best replication rates were obtained at parameter settings of 115°C, 10?kN, and 8?min for the molds with minimum 56?µm wide features of 120?µm depth. We also showed that the fabricated channels could be successfully sealed by solvent-assisted thermo-compressive bonding at 85°C under 5.5?kN force. 相似文献
Hierarchically structured materials comprising rod‐like, chiral, nanoparticles are commonly encountered in nature as they can form assemblies with exceptional optical and mechanical characteristics. These include cellulose nanocrystals (CNCs), which have a large potential for the fabrication of bioinspired materials mimicking those advanced properties. Fine‐tuning the optomechanical properties of assemblies obtained from CNCs hinges on the transformations from suspensions of liquid crystals to long‐range order in the dry state. So far, associated transitions have been studied using trivial interfaces such as planar substrates. Such transitions are explored as they evolve onto meshed supports. The meshed substrate offers a complex topology, as is encountered in nature, for the formation of CNCs films. The CNCs self‐assembly occurs under confinement and support of the framework bounding the mesh openings. This leads to coexisting suspended and supported nanoparticle layers exhibiting nematic and/or chiral nematic order. Optical microscopy combined with crossed polarizers indicate that the formation of the suspended films occurs via intermediate gelation or kinetic arrest of CNCs across the mesh's open areas. The formation of self‐standing, ultrathin films of CNCs with tunable optical properties, such as selective reflections in the visible range (structural color), is demonstrated by using the presented simple and scalable approach. 相似文献
Ternary Ⅲ-Ⅴ nanowires (NWs) cover a wide range of wavelengths in the solar spectrum and would greatly benefit from being synthesized as position-controlled arrays for improved vertical yield,reprodudbility,and tunable optical absorption.Here,we report on successful selective-area epitaxy of metal-particle-free vertical InxGa1-xP NW arrays using metal-organic vapor phase epitaxy and detail their optical properties.A systematic growth study establishes the range of suitable growth parameters to obtain uniform NW growth over a large array.The optical properties of the NWs were characterized by room-temperature cathodoluminescence spectroscopy.Tunability of the emission wavelength from 870 nm to approximately 800 nm was achieved.Transmission electron microscopy and energy dispersive X-ray measurements performed on crosssection samples revealed a pure wurtzite crystal structure with very few stacking faults and a slight composition gradient along the NW growth axis. 相似文献